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sctp_indata.c

/*-
 * Copyright (c) 2001-2007, by Cisco Systems, Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * a) Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 *
 * b) Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *   the documentation and/or other materials provided with the distribution.
 *
 * c) Neither the name of Cisco Systems, Inc. nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

/* $KAME: sctp_indata.c,v 1.36 2005/03/06 16:04:17 itojun Exp $    */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/sys/netinet/sctp_indata.c,v 1.45.2.2.2.1 2008/01/31 17:21:50 rrs Exp $");

#include <netinet/sctp_os.h>
#include <netinet/sctp_var.h>
#include <netinet/sctp_sysctl.h>
#include <netinet/sctp_pcb.h>
#include <netinet/sctp_header.h>
#include <netinet/sctputil.h>
#include <netinet/sctp_output.h>
#include <netinet/sctp_input.h>
#include <netinet/sctp_indata.h>
#include <netinet/sctp_uio.h>
#include <netinet/sctp_timer.h>


/*
 * NOTES: On the outbound side of things I need to check the sack timer to
 * see if I should generate a sack into the chunk queue (if I have data to
 * send that is and will be sending it .. for bundling.
 *
 * The callback in sctp_usrreq.c will get called when the socket is read from.
 * This will cause sctp_service_queues() to get called on the top entry in
 * the list.
 */

void
sctp_set_rwnd(struct sctp_tcb *stcb, struct sctp_association *asoc)
{
      uint32_t calc, calc_save;

      /*
       * This is really set wrong with respect to a 1-2-m socket. Since
       * the sb_cc is the count that everyone as put up. When we re-write
       * sctp_soreceive then we will fix this so that ONLY this
       * associations data is taken into account.
       */
      if (stcb->sctp_socket == NULL)
            return;

      if (stcb->asoc.sb_cc == 0 &&
          asoc->size_on_reasm_queue == 0 &&
          asoc->size_on_all_streams == 0) {
            /* Full rwnd granted */
            asoc->my_rwnd = max(SCTP_SB_LIMIT_RCV(stcb->sctp_socket),
                SCTP_MINIMAL_RWND);
            return;
      }
      /* get actual space */
      calc = (uint32_t) sctp_sbspace(&stcb->asoc, &stcb->sctp_socket->so_rcv);

      /*
       * take out what has NOT been put on socket queue and we yet hold
       * for putting up.
       */
      calc = sctp_sbspace_sub(calc, (uint32_t) asoc->size_on_reasm_queue);
      calc = sctp_sbspace_sub(calc, (uint32_t) asoc->size_on_all_streams);

      if (calc == 0) {
            /* out of space */
            asoc->my_rwnd = 0;
            return;
      }
      /* what is the overhead of all these rwnd's */

      calc = sctp_sbspace_sub(calc, stcb->asoc.my_rwnd_control_len);
      calc_save = calc;

      asoc->my_rwnd = calc;
      if ((asoc->my_rwnd == 0) &&
          (calc < stcb->asoc.my_rwnd_control_len)) {
            /*-
             * If our rwnd == 0 && the overhead is greater than the
             * data onqueue, we clamp the rwnd to 1. This lets us
             * still accept inbound segments, but hopefully will shut
             * the sender down when he finally gets the message. This
             * hopefully will gracefully avoid discarding packets.
             */
            asoc->my_rwnd = 1;
      }
      if (asoc->my_rwnd &&
          (asoc->my_rwnd < stcb->sctp_ep->sctp_ep.sctp_sws_receiver)) {
            /* SWS engaged, tell peer none left */
            asoc->my_rwnd = 1;
      }
}

/* Calculate what the rwnd would be */
uint32_t
sctp_calc_rwnd(struct sctp_tcb *stcb, struct sctp_association *asoc)
{
      uint32_t calc = 0, calc_save = 0, result = 0;

      /*
       * This is really set wrong with respect to a 1-2-m socket. Since
       * the sb_cc is the count that everyone as put up. When we re-write
       * sctp_soreceive then we will fix this so that ONLY this
       * associations data is taken into account.
       */
      if (stcb->sctp_socket == NULL)
            return (calc);

      if (stcb->asoc.sb_cc == 0 &&
          asoc->size_on_reasm_queue == 0 &&
          asoc->size_on_all_streams == 0) {
            /* Full rwnd granted */
            calc = max(SCTP_SB_LIMIT_RCV(stcb->sctp_socket),
                SCTP_MINIMAL_RWND);
            return (calc);
      }
      /* get actual space */
      calc = (uint32_t) sctp_sbspace(&stcb->asoc, &stcb->sctp_socket->so_rcv);

      /*
       * take out what has NOT been put on socket queue and we yet hold
       * for putting up.
       */
      calc = sctp_sbspace_sub(calc, (uint32_t) asoc->size_on_reasm_queue);
      calc = sctp_sbspace_sub(calc, (uint32_t) asoc->size_on_all_streams);

      if (calc == 0) {
            /* out of space */
            return (calc);
      }
      /* what is the overhead of all these rwnd's */
      calc = sctp_sbspace_sub(calc, stcb->asoc.my_rwnd_control_len);
      calc_save = calc;

      result = calc;
      if ((result == 0) &&
          (calc < stcb->asoc.my_rwnd_control_len)) {
            /*-
             * If our rwnd == 0 && the overhead is greater than the
             * data onqueue, we clamp the rwnd to 1. This lets us
             * still accept inbound segments, but hopefully will shut
             * the sender down when he finally gets the message. This
             * hopefully will gracefully avoid discarding packets.
             */
            result = 1;
      }
      if (result &&
          (result < stcb->sctp_ep->sctp_ep.sctp_sws_receiver)) {
            /* SWS engaged, tell peer none left */
            result = 1;
      }
      return (result);
}



/*
 * Build out our readq entry based on the incoming packet.
 */
struct sctp_queued_to_read *
sctp_build_readq_entry(struct sctp_tcb *stcb,
    struct sctp_nets *net,
    uint32_t tsn, uint32_t ppid,
    uint32_t context, uint16_t stream_no,
    uint16_t stream_seq, uint8_t flags,
    struct mbuf *dm)
{
      struct sctp_queued_to_read *read_queue_e = NULL;

      sctp_alloc_a_readq(stcb, read_queue_e);
      if (read_queue_e == NULL) {
            goto failed_build;
      }
      read_queue_e->sinfo_stream = stream_no;
      read_queue_e->sinfo_ssn = stream_seq;
      read_queue_e->sinfo_flags = (flags << 8);
      read_queue_e->sinfo_ppid = ppid;
      read_queue_e->sinfo_context = stcb->asoc.context;
      read_queue_e->sinfo_timetolive = 0;
      read_queue_e->sinfo_tsn = tsn;
      read_queue_e->sinfo_cumtsn = tsn;
      read_queue_e->sinfo_assoc_id = sctp_get_associd(stcb);
      read_queue_e->whoFrom = net;
      read_queue_e->length = 0;
      atomic_add_int(&net->ref_count, 1);
      read_queue_e->data = dm;
      read_queue_e->spec_flags = 0;
      read_queue_e->tail_mbuf = NULL;
      read_queue_e->aux_data = NULL;
      read_queue_e->stcb = stcb;
      read_queue_e->port_from = stcb->rport;
      read_queue_e->do_not_ref_stcb = 0;
      read_queue_e->end_added = 0;
      read_queue_e->some_taken = 0;
      read_queue_e->pdapi_aborted = 0;
failed_build:
      return (read_queue_e);
}


/*
 * Build out our readq entry based on the incoming packet.
 */
static struct sctp_queued_to_read *
sctp_build_readq_entry_chk(struct sctp_tcb *stcb,
    struct sctp_tmit_chunk *chk)
{
      struct sctp_queued_to_read *read_queue_e = NULL;

      sctp_alloc_a_readq(stcb, read_queue_e);
      if (read_queue_e == NULL) {
            goto failed_build;
      }
      read_queue_e->sinfo_stream = chk->rec.data.stream_number;
      read_queue_e->sinfo_ssn = chk->rec.data.stream_seq;
      read_queue_e->sinfo_flags = (chk->rec.data.rcv_flags << 8);
      read_queue_e->sinfo_ppid = chk->rec.data.payloadtype;
      read_queue_e->sinfo_context = stcb->asoc.context;
      read_queue_e->sinfo_timetolive = 0;
      read_queue_e->sinfo_tsn = chk->rec.data.TSN_seq;
      read_queue_e->sinfo_cumtsn = chk->rec.data.TSN_seq;
      read_queue_e->sinfo_assoc_id = sctp_get_associd(stcb);
      read_queue_e->whoFrom = chk->whoTo;
      read_queue_e->aux_data = NULL;
      read_queue_e->length = 0;
      atomic_add_int(&chk->whoTo->ref_count, 1);
      read_queue_e->data = chk->data;
      read_queue_e->tail_mbuf = NULL;
      read_queue_e->stcb = stcb;
      read_queue_e->port_from = stcb->rport;
      read_queue_e->spec_flags = 0;
      read_queue_e->do_not_ref_stcb = 0;
      read_queue_e->end_added = 0;
      read_queue_e->some_taken = 0;
      read_queue_e->pdapi_aborted = 0;
failed_build:
      return (read_queue_e);
}


struct mbuf *
sctp_build_ctl_nchunk(struct sctp_inpcb *inp,
    struct sctp_sndrcvinfo *sinfo)
{
      struct sctp_sndrcvinfo *outinfo;
      struct cmsghdr *cmh;
      struct mbuf *ret;
      int len;
      int use_extended = 0;

      if (sctp_is_feature_off(inp, SCTP_PCB_FLAGS_RECVDATAIOEVNT)) {
            /* user does not want the sndrcv ctl */
            return (NULL);
      }
      if (sctp_is_feature_on(inp, SCTP_PCB_FLAGS_EXT_RCVINFO)) {
            use_extended = 1;
            len = CMSG_LEN(sizeof(struct sctp_extrcvinfo));
      } else {
            len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
      }


      ret = sctp_get_mbuf_for_msg(len,
          0, M_DONTWAIT, 1, MT_DATA);

      if (ret == NULL) {
            /* No space */
            return (ret);
      }
      /* We need a CMSG header followed by the struct  */
      cmh = mtod(ret, struct cmsghdr *);
      outinfo = (struct sctp_sndrcvinfo *)CMSG_DATA(cmh);
      cmh->cmsg_level = IPPROTO_SCTP;
      if (use_extended) {
            cmh->cmsg_type = SCTP_EXTRCV;
            cmh->cmsg_len = len;
            memcpy(outinfo, sinfo, len);
      } else {
            cmh->cmsg_type = SCTP_SNDRCV;
            cmh->cmsg_len = len;
            *outinfo = *sinfo;
      }
      SCTP_BUF_LEN(ret) = cmh->cmsg_len;
      return (ret);
}


char *
sctp_build_ctl_cchunk(struct sctp_inpcb *inp,
    int *control_len,
    struct sctp_sndrcvinfo *sinfo)
{
      struct sctp_sndrcvinfo *outinfo;
      struct cmsghdr *cmh;
      char *buf;
      int len;
      int use_extended = 0;

      if (sctp_is_feature_off(inp, SCTP_PCB_FLAGS_RECVDATAIOEVNT)) {
            /* user does not want the sndrcv ctl */
            return (NULL);
      }
      if (sctp_is_feature_on(inp, SCTP_PCB_FLAGS_EXT_RCVINFO)) {
            use_extended = 1;
            len = CMSG_LEN(sizeof(struct sctp_extrcvinfo));
      } else {
            len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
      }
      SCTP_MALLOC(buf, char *, len, SCTP_M_CMSG);
      if (buf == NULL) {
            /* No space */
            return (buf);
      }
      /* We need a CMSG header followed by the struct  */
      cmh = (struct cmsghdr *)buf;
      outinfo = (struct sctp_sndrcvinfo *)CMSG_DATA(cmh);
      cmh->cmsg_level = IPPROTO_SCTP;
      if (use_extended) {
            cmh->cmsg_type = SCTP_EXTRCV;
            cmh->cmsg_len = len;
            memcpy(outinfo, sinfo, len);
      } else {
            cmh->cmsg_type = SCTP_SNDRCV;
            cmh->cmsg_len = len;
            *outinfo = *sinfo;
      }
      *control_len = len;
      return (buf);
}


/*
 * We are delivering currently from the reassembly queue. We must continue to
 * deliver until we either: 1) run out of space. 2) run out of sequential
 * TSN's 3) hit the SCTP_DATA_LAST_FRAG flag.
 */
static void
sctp_service_reassembly(struct sctp_tcb *stcb, struct sctp_association *asoc)
{
      struct sctp_tmit_chunk *chk;
      uint16_t nxt_todel;
      uint16_t stream_no;
      int end = 0;
      int cntDel;
      struct sctp_queued_to_read *control, *ctl, *ctlat;

      if (stcb == NULL)
            return;

      cntDel = stream_no = 0;
      if ((stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE) ||
          (stcb->asoc.state & SCTP_STATE_ABOUT_TO_BE_FREED) ||
          (stcb->asoc.state & SCTP_STATE_CLOSED_SOCKET)) {
            /* socket above is long gone or going.. */
abandon:
            asoc->fragmented_delivery_inprogress = 0;
            chk = TAILQ_FIRST(&asoc->reasmqueue);
            while (chk) {
                  TAILQ_REMOVE(&asoc->reasmqueue, chk, sctp_next);
                  asoc->size_on_reasm_queue -= chk->send_size;
                  sctp_ucount_decr(asoc->cnt_on_reasm_queue);
                  /*
                   * Lose the data pointer, since its in the socket
                   * buffer
                   */
                  if (chk->data) {
                        sctp_m_freem(chk->data);
                        chk->data = NULL;
                  }
                  /* Now free the address and data */
                  sctp_free_a_chunk(stcb, chk);
                  /* sa_ignore FREED_MEMORY */
                  chk = TAILQ_FIRST(&asoc->reasmqueue);
            }
            return;
      }
      SCTP_TCB_LOCK_ASSERT(stcb);
      do {
            chk = TAILQ_FIRST(&asoc->reasmqueue);
            if (chk == NULL) {
                  return;
            }
            if (chk->rec.data.TSN_seq != (asoc->tsn_last_delivered + 1)) {
                  /* Can't deliver more :< */
                  return;
            }
            stream_no = chk->rec.data.stream_number;
            nxt_todel = asoc->strmin[stream_no].last_sequence_delivered + 1;
            if (nxt_todel != chk->rec.data.stream_seq &&
                (chk->rec.data.rcv_flags & SCTP_DATA_UNORDERED) == 0) {
                  /*
                   * Not the next sequence to deliver in its stream OR
                   * unordered
                   */
                  return;
            }
            if (chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) {

                  control = sctp_build_readq_entry_chk(stcb, chk);
                  if (control == NULL) {
                        /* out of memory? */
                        return;
                  }
                  /* save it off for our future deliveries */
                  stcb->asoc.control_pdapi = control;
                  if (chk->rec.data.rcv_flags & SCTP_DATA_LAST_FRAG)
                        end = 1;
                  else
                        end = 0;
                  sctp_add_to_readq(stcb->sctp_ep,
                      stcb, control, &stcb->sctp_socket->so_rcv, end, SCTP_SO_NOT_LOCKED);
                  cntDel++;
            } else {
                  if (chk->rec.data.rcv_flags & SCTP_DATA_LAST_FRAG)
                        end = 1;
                  else
                        end = 0;
                  if (sctp_append_to_readq(stcb->sctp_ep, stcb,
                      stcb->asoc.control_pdapi,
                      chk->data, end, chk->rec.data.TSN_seq,
                      &stcb->sctp_socket->so_rcv)) {
                        /*
                         * something is very wrong, either
                         * control_pdapi is NULL, or the tail_mbuf
                         * is corrupt, or there is a EOM already on
                         * the mbuf chain.
                         */
                        if (stcb->asoc.state & SCTP_STATE_ABOUT_TO_BE_FREED) {
                              goto abandon;
                        } else {
                              if ((stcb->asoc.control_pdapi == NULL) || (stcb->asoc.control_pdapi->tail_mbuf == NULL)) {
                                    panic("This should not happen control_pdapi NULL?");
                              }
                              /* if we did not panic, it was a EOM */
                              panic("Bad chunking ??");
                              return;
                        }
                  }
                  cntDel++;
            }
            /* pull it we did it */
            TAILQ_REMOVE(&asoc->reasmqueue, chk, sctp_next);
            if (chk->rec.data.rcv_flags & SCTP_DATA_LAST_FRAG) {
                  asoc->fragmented_delivery_inprogress = 0;
                  if ((chk->rec.data.rcv_flags & SCTP_DATA_UNORDERED) == 0) {
                        asoc->strmin[stream_no].last_sequence_delivered++;
                  }
                  if ((chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) == 0) {
                        SCTP_STAT_INCR_COUNTER64(sctps_reasmusrmsgs);
                  }
            } else if (chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) {
                  /*
                   * turn the flag back on since we just  delivered
                   * yet another one.
                   */
                  asoc->fragmented_delivery_inprogress = 1;
            }
            asoc->tsn_of_pdapi_last_delivered = chk->rec.data.TSN_seq;
            asoc->last_flags_delivered = chk->rec.data.rcv_flags;
            asoc->last_strm_seq_delivered = chk->rec.data.stream_seq;
            asoc->last_strm_no_delivered = chk->rec.data.stream_number;

            asoc->tsn_last_delivered = chk->rec.data.TSN_seq;
            asoc->size_on_reasm_queue -= chk->send_size;
            sctp_ucount_decr(asoc->cnt_on_reasm_queue);
            /* free up the chk */
            chk->data = NULL;
            sctp_free_a_chunk(stcb, chk);

            if (asoc->fragmented_delivery_inprogress == 0) {
                  /*
                   * Now lets see if we can deliver the next one on
                   * the stream
                   */
                  struct sctp_stream_in *strm;

                  strm = &asoc->strmin[stream_no];
                  nxt_todel = strm->last_sequence_delivered + 1;
                  ctl = TAILQ_FIRST(&strm->inqueue);
                  if (ctl && (nxt_todel == ctl->sinfo_ssn)) {
                        while (ctl != NULL) {
                              /* Deliver more if we can. */
                              if (nxt_todel == ctl->sinfo_ssn) {
                                    ctlat = TAILQ_NEXT(ctl, next);
                                    TAILQ_REMOVE(&strm->inqueue, ctl, next);
                                    asoc->size_on_all_streams -= ctl->length;
                                    sctp_ucount_decr(asoc->cnt_on_all_streams);
                                    strm->last_sequence_delivered++;
                                    sctp_add_to_readq(stcb->sctp_ep, stcb,
                                        ctl,
                                        &stcb->sctp_socket->so_rcv, 1, SCTP_SO_NOT_LOCKED);
                                    ctl = ctlat;
                              } else {
                                    break;
                              }
                              nxt_todel = strm->last_sequence_delivered + 1;
                        }
                  }
                  break;
            }
            /* sa_ignore FREED_MEMORY */
            chk = TAILQ_FIRST(&asoc->reasmqueue);
      } while (chk);
}

/*
 * Queue the chunk either right into the socket buffer if it is the next one
 * to go OR put it in the correct place in the delivery queue.  If we do
 * append to the so_buf, keep doing so until we are out of order. One big
 * question still remains, what to do when the socket buffer is FULL??
 */
static void
sctp_queue_data_to_stream(struct sctp_tcb *stcb, struct sctp_association *asoc,
    struct sctp_queued_to_read *control, int *abort_flag)
{
      /*
       * FIX-ME maybe? What happens when the ssn wraps? If we are getting
       * all the data in one stream this could happen quite rapidly. One
       * could use the TSN to keep track of things, but this scheme breaks
       * down in the other type of stream useage that could occur. Send a
       * single msg to stream 0, send 4Billion messages to stream 1, now
       * send a message to stream 0. You have a situation where the TSN
       * has wrapped but not in the stream. Is this worth worrying about
       * or should we just change our queue sort at the bottom to be by
       * TSN.
       * 
       * Could it also be legal for a peer to send ssn 1 with TSN 2 and ssn 2
       * with TSN 1? If the peer is doing some sort of funky TSN/SSN
       * assignment this could happen... and I don't see how this would be
       * a violation. So for now I am undecided an will leave the sort by
       * SSN alone. Maybe a hybred approach is the answer
       * 
       */
      struct sctp_stream_in *strm;
      struct sctp_queued_to_read *at;
      int queue_needed;
      uint16_t nxt_todel;
      struct mbuf *oper;

      queue_needed = 1;
      asoc->size_on_all_streams += control->length;
      sctp_ucount_incr(asoc->cnt_on_all_streams);
      strm = &asoc->strmin[control->sinfo_stream];
      nxt_todel = strm->last_sequence_delivered + 1;
      if (sctp_logging_level & SCTP_STR_LOGGING_ENABLE) {
            sctp_log_strm_del(control, NULL, SCTP_STR_LOG_FROM_INTO_STRD);
      }
      SCTPDBG(SCTP_DEBUG_INDATA1,
          "queue to stream called for ssn:%u lastdel:%u nxt:%u\n",
          (uint32_t) control->sinfo_stream,
          (uint32_t) strm->last_sequence_delivered,
          (uint32_t) nxt_todel);
      if (compare_with_wrap(strm->last_sequence_delivered,
          control->sinfo_ssn, MAX_SEQ) ||
          (strm->last_sequence_delivered == control->sinfo_ssn)) {
            /* The incoming sseq is behind where we last delivered? */
            SCTPDBG(SCTP_DEBUG_INDATA1, "Duplicate S-SEQ:%d delivered:%d from peer, Abort  association\n",
                control->sinfo_ssn, strm->last_sequence_delivered);
            /*
             * throw it in the stream so it gets cleaned up in
             * association destruction
             */
            TAILQ_INSERT_HEAD(&strm->inqueue, control, next);
            oper = sctp_get_mbuf_for_msg((sizeof(struct sctp_paramhdr) + 3 * sizeof(uint32_t)),
                0, M_DONTWAIT, 1, MT_DATA);
            if (oper) {
                  struct sctp_paramhdr *ph;
                  uint32_t *ippp;

                  SCTP_BUF_LEN(oper) = sizeof(struct sctp_paramhdr) +
                      (sizeof(uint32_t) * 3);
                  ph = mtod(oper, struct sctp_paramhdr *);
                  ph->param_type = htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                  ph->param_length = htons(SCTP_BUF_LEN(oper));
                  ippp = (uint32_t *) (ph + 1);
                  *ippp = htonl(SCTP_FROM_SCTP_INDATA + SCTP_LOC_1);
                  ippp++;
                  *ippp = control->sinfo_tsn;
                  ippp++;
                  *ippp = ((control->sinfo_stream << 16) | control->sinfo_ssn);
            }
            stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_1;
            sctp_abort_an_association(stcb->sctp_ep, stcb,
                SCTP_PEER_FAULTY, oper, SCTP_SO_NOT_LOCKED);

            *abort_flag = 1;
            return;

      }
      if (nxt_todel == control->sinfo_ssn) {
            /* can be delivered right away? */
            if (sctp_logging_level & SCTP_STR_LOGGING_ENABLE) {
                  sctp_log_strm_del(control, NULL, SCTP_STR_LOG_FROM_IMMED_DEL);
            }
            queue_needed = 0;
            asoc->size_on_all_streams -= control->length;
            sctp_ucount_decr(asoc->cnt_on_all_streams);
            strm->last_sequence_delivered++;
            sctp_add_to_readq(stcb->sctp_ep, stcb,
                control,
                &stcb->sctp_socket->so_rcv, 1, SCTP_SO_NOT_LOCKED);
            control = TAILQ_FIRST(&strm->inqueue);
            while (control != NULL) {
                  /* all delivered */
                  nxt_todel = strm->last_sequence_delivered + 1;
                  if (nxt_todel == control->sinfo_ssn) {
                        at = TAILQ_NEXT(control, next);
                        TAILQ_REMOVE(&strm->inqueue, control, next);
                        asoc->size_on_all_streams -= control->length;
                        sctp_ucount_decr(asoc->cnt_on_all_streams);
                        strm->last_sequence_delivered++;
                        /*
                         * We ignore the return of deliver_data here
                         * since we always can hold the chunk on the
                         * d-queue. And we have a finite number that
                         * can be delivered from the strq.
                         */
                        if (sctp_logging_level & SCTP_STR_LOGGING_ENABLE) {
                              sctp_log_strm_del(control, NULL,
                                  SCTP_STR_LOG_FROM_IMMED_DEL);
                        }
                        sctp_add_to_readq(stcb->sctp_ep, stcb,
                            control,
                            &stcb->sctp_socket->so_rcv, 1, SCTP_SO_NOT_LOCKED);
                        control = at;
                        continue;
                  }
                  break;
            }
      }
      if (queue_needed) {
            /*
             * Ok, we did not deliver this guy, find the correct place
             * to put it on the queue.
             */
            if (TAILQ_EMPTY(&strm->inqueue)) {
                  /* Empty queue */
                  if (sctp_logging_level & SCTP_STR_LOGGING_ENABLE) {
                        sctp_log_strm_del(control, NULL, SCTP_STR_LOG_FROM_INSERT_HD);
                  }
                  TAILQ_INSERT_HEAD(&strm->inqueue, control, next);
            } else {
                  TAILQ_FOREACH(at, &strm->inqueue, next) {
                        if (compare_with_wrap(at->sinfo_ssn,
                            control->sinfo_ssn, MAX_SEQ)) {
                              /*
                               * one in queue is bigger than the
                               * new one, insert before this one
                               */
                              if (sctp_logging_level & SCTP_STR_LOGGING_ENABLE) {
                                    sctp_log_strm_del(control, at,
                                        SCTP_STR_LOG_FROM_INSERT_MD);
                              }
                              TAILQ_INSERT_BEFORE(at, control, next);
                              break;
                        } else if (at->sinfo_ssn == control->sinfo_ssn) {
                              /*
                               * Gak, He sent me a duplicate str
                               * seq number
                               */
                              /*
                               * foo bar, I guess I will just free
                               * this new guy, should we abort
                               * too? FIX ME MAYBE? Or it COULD be
                               * that the SSN's have wrapped.
                               * Maybe I should compare to TSN
                               * somehow... sigh for now just blow
                               * away the chunk!
                               */

                              if (control->data)
                                    sctp_m_freem(control->data);
                              control->data = NULL;
                              asoc->size_on_all_streams -= control->length;
                              sctp_ucount_decr(asoc->cnt_on_all_streams);
                              if (control->whoFrom)
                                    sctp_free_remote_addr(control->whoFrom);
                              control->whoFrom = NULL;
                              sctp_free_a_readq(stcb, control);
                              return;
                        } else {
                              if (TAILQ_NEXT(at, next) == NULL) {
                                    /*
                                     * We are at the end, insert
                                     * it after this one
                                     */
                                    if (sctp_logging_level & SCTP_STR_LOGGING_ENABLE) {
                                          sctp_log_strm_del(control, at,
                                              SCTP_STR_LOG_FROM_INSERT_TL);
                                    }
                                    TAILQ_INSERT_AFTER(&strm->inqueue,
                                        at, control, next);
                                    break;
                              }
                        }
                  }
            }
      }
}

/*
 * Returns two things: You get the total size of the deliverable parts of the
 * first fragmented message on the reassembly queue. And you get a 1 back if
 * all of the message is ready or a 0 back if the message is still incomplete
 */
static int
sctp_is_all_msg_on_reasm(struct sctp_association *asoc, uint32_t * t_size)
{
      struct sctp_tmit_chunk *chk;
      uint32_t tsn;

      *t_size = 0;
      chk = TAILQ_FIRST(&asoc->reasmqueue);
      if (chk == NULL) {
            /* nothing on the queue */
            return (0);
      }
      if ((chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) == 0) {
            /* Not a first on the queue */
            return (0);
      }
      tsn = chk->rec.data.TSN_seq;
      while (chk) {
            if (tsn != chk->rec.data.TSN_seq) {
                  return (0);
            }
            *t_size += chk->send_size;
            if (chk->rec.data.rcv_flags & SCTP_DATA_LAST_FRAG) {
                  return (1);
            }
            tsn++;
            chk = TAILQ_NEXT(chk, sctp_next);
      }
      return (0);
}

static void
sctp_deliver_reasm_check(struct sctp_tcb *stcb, struct sctp_association *asoc)
{
      struct sctp_tmit_chunk *chk;
      uint16_t nxt_todel;
      uint32_t tsize;

doit_again:
      chk = TAILQ_FIRST(&asoc->reasmqueue);
      if (chk == NULL) {
            /* Huh? */
            asoc->size_on_reasm_queue = 0;
            asoc->cnt_on_reasm_queue = 0;
            return;
      }
      if (asoc->fragmented_delivery_inprogress == 0) {
            nxt_todel =
                asoc->strmin[chk->rec.data.stream_number].last_sequence_delivered + 1;
            if ((chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) &&
                (nxt_todel == chk->rec.data.stream_seq ||
                (chk->rec.data.rcv_flags & SCTP_DATA_UNORDERED))) {
                  /*
                   * Yep the first one is here and its ok to deliver
                   * but should we?
                   */
                  if ((sctp_is_all_msg_on_reasm(asoc, &tsize) ||
                      (tsize >= stcb->sctp_ep->partial_delivery_point))) {

                        /*
                         * Yes, we setup to start reception, by
                         * backing down the TSN just in case we
                         * can't deliver. If we
                         */
                        asoc->fragmented_delivery_inprogress = 1;
                        asoc->tsn_last_delivered =
                            chk->rec.data.TSN_seq - 1;
                        asoc->str_of_pdapi =
                            chk->rec.data.stream_number;
                        asoc->ssn_of_pdapi = chk->rec.data.stream_seq;
                        asoc->pdapi_ppid = chk->rec.data.payloadtype;
                        asoc->fragment_flags = chk->rec.data.rcv_flags;
                        sctp_service_reassembly(stcb, asoc);
                  }
            }
      } else {
            /*
             * Service re-assembly will deliver stream data queued at
             * the end of fragmented delivery.. but it wont know to go
             * back and call itself again... we do that here with the
             * got doit_again
             */
            sctp_service_reassembly(stcb, asoc);
            if (asoc->fragmented_delivery_inprogress == 0) {
                  /*
                   * finished our Fragmented delivery, could be more
                   * waiting?
                   */
                  goto doit_again;
            }
      }
}

/*
 * Dump onto the re-assembly queue, in its proper place. After dumping on the
 * queue, see if anthing can be delivered. If so pull it off (or as much as
 * we can. If we run out of space then we must dump what we can and set the
 * appropriate flag to say we queued what we could.
 */
static void
sctp_queue_data_for_reasm(struct sctp_tcb *stcb, struct sctp_association *asoc,
    struct sctp_tmit_chunk *chk, int *abort_flag)
{
      struct mbuf *oper;
      uint32_t cum_ackp1, last_tsn, prev_tsn, post_tsn;
      u_char last_flags;
      struct sctp_tmit_chunk *at, *prev, *next;

      prev = next = NULL;
      cum_ackp1 = asoc->tsn_last_delivered + 1;
      if (TAILQ_EMPTY(&asoc->reasmqueue)) {
            /* This is the first one on the queue */
            TAILQ_INSERT_HEAD(&asoc->reasmqueue, chk, sctp_next);
            /*
             * we do not check for delivery of anything when only one
             * fragment is here
             */
            asoc->size_on_reasm_queue = chk->send_size;
            sctp_ucount_incr(asoc->cnt_on_reasm_queue);
            if (chk->rec.data.TSN_seq == cum_ackp1) {
                  if (asoc->fragmented_delivery_inprogress == 0 &&
                      (chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) !=
                      SCTP_DATA_FIRST_FRAG) {
                        /*
                         * An empty queue, no delivery inprogress,
                         * we hit the next one and it does NOT have
                         * a FIRST fragment mark.
                         */
                        SCTPDBG(SCTP_DEBUG_INDATA1, "Gak, Evil plot, its not first, no fragmented delivery in progress\n");
                        oper = sctp_get_mbuf_for_msg((sizeof(struct sctp_paramhdr) + 3 * sizeof(uint32_t)),
                            0, M_DONTWAIT, 1, MT_DATA);

                        if (oper) {
                              struct sctp_paramhdr *ph;
                              uint32_t *ippp;

                              SCTP_BUF_LEN(oper) =
                                  sizeof(struct sctp_paramhdr) +
                                  (sizeof(uint32_t) * 3);
                              ph = mtod(oper, struct sctp_paramhdr *);
                              ph->param_type =
                                  htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                              ph->param_length = htons(SCTP_BUF_LEN(oper));
                              ippp = (uint32_t *) (ph + 1);
                              *ippp = htonl(SCTP_FROM_SCTP_INDATA + SCTP_LOC_2);
                              ippp++;
                              *ippp = chk->rec.data.TSN_seq;
                              ippp++;
                              *ippp = ((chk->rec.data.stream_number << 16) | chk->rec.data.stream_seq);

                        }
                        stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_2;
                        sctp_abort_an_association(stcb->sctp_ep, stcb,
                            SCTP_PEER_FAULTY, oper, SCTP_SO_NOT_LOCKED);
                        *abort_flag = 1;
                  } else if (asoc->fragmented_delivery_inprogress &&
                      (chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) == SCTP_DATA_FIRST_FRAG) {
                        /*
                         * We are doing a partial delivery and the
                         * NEXT chunk MUST be either the LAST or
                         * MIDDLE fragment NOT a FIRST
                         */
                        SCTPDBG(SCTP_DEBUG_INDATA1, "Gak, Evil plot, it IS a first and fragmented delivery in progress\n");
                        oper = sctp_get_mbuf_for_msg((sizeof(struct sctp_paramhdr) + 3 * sizeof(uint32_t)),
                            0, M_DONTWAIT, 1, MT_DATA);
                        if (oper) {
                              struct sctp_paramhdr *ph;
                              uint32_t *ippp;

                              SCTP_BUF_LEN(oper) =
                                  sizeof(struct sctp_paramhdr) +
                                  (3 * sizeof(uint32_t));
                              ph = mtod(oper, struct sctp_paramhdr *);
                              ph->param_type =
                                  htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                              ph->param_length = htons(SCTP_BUF_LEN(oper));
                              ippp = (uint32_t *) (ph + 1);
                              *ippp = htonl(SCTP_FROM_SCTP_INDATA + SCTP_LOC_3);
                              ippp++;
                              *ippp = chk->rec.data.TSN_seq;
                              ippp++;
                              *ippp = ((chk->rec.data.stream_number << 16) | chk->rec.data.stream_seq);
                        }
                        stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_3;
                        sctp_abort_an_association(stcb->sctp_ep, stcb,
                            SCTP_PEER_FAULTY, oper, SCTP_SO_NOT_LOCKED);
                        *abort_flag = 1;
                  } else if (asoc->fragmented_delivery_inprogress) {
                        /*
                         * Here we are ok with a MIDDLE or LAST
                         * piece
                         */
                        if (chk->rec.data.stream_number !=
                            asoc->str_of_pdapi) {
                              /* Got to be the right STR No */
                              SCTPDBG(SCTP_DEBUG_INDATA1, "Gak, Evil plot, it IS not same stream number %d vs %d\n",
                                  chk->rec.data.stream_number,
                                  asoc->str_of_pdapi);
                              oper = sctp_get_mbuf_for_msg((sizeof(struct sctp_paramhdr) + 3 * sizeof(uint32_t)),
                                  0, M_DONTWAIT, 1, MT_DATA);
                              if (oper) {
                                    struct sctp_paramhdr *ph;
                                    uint32_t *ippp;

                                    SCTP_BUF_LEN(oper) =
                                        sizeof(struct sctp_paramhdr) +
                                        (sizeof(uint32_t) * 3);
                                    ph = mtod(oper,
                                        struct sctp_paramhdr *);
                                    ph->param_type =
                                        htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                    ph->param_length =
                                        htons(SCTP_BUF_LEN(oper));
                                    ippp = (uint32_t *) (ph + 1);
                                    *ippp = htonl(SCTP_FROM_SCTP_INDATA + SCTP_LOC_4);
                                    ippp++;
                                    *ippp = chk->rec.data.TSN_seq;
                                    ippp++;
                                    *ippp = ((chk->rec.data.stream_number << 16) | chk->rec.data.stream_seq);
                              }
                              stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_4;
                              sctp_abort_an_association(stcb->sctp_ep,
                                  stcb, SCTP_PEER_FAULTY, oper, SCTP_SO_NOT_LOCKED);
                              *abort_flag = 1;
                        } else if ((asoc->fragment_flags & SCTP_DATA_UNORDERED) !=
                                  SCTP_DATA_UNORDERED &&
                                  chk->rec.data.stream_seq !=
                            asoc->ssn_of_pdapi) {
                              /* Got to be the right STR Seq */
                              SCTPDBG(SCTP_DEBUG_INDATA1, "Gak, Evil plot, it IS not same stream seq %d vs %d\n",
                                  chk->rec.data.stream_seq,
                                  asoc->ssn_of_pdapi);
                              oper = sctp_get_mbuf_for_msg((sizeof(struct sctp_paramhdr) + 3 * sizeof(uint32_t)),
                                  0, M_DONTWAIT, 1, MT_DATA);
                              if (oper) {
                                    struct sctp_paramhdr *ph;
                                    uint32_t *ippp;

                                    SCTP_BUF_LEN(oper) =
                                        sizeof(struct sctp_paramhdr) +
                                        (3 * sizeof(uint32_t));
                                    ph = mtod(oper,
                                        struct sctp_paramhdr *);
                                    ph->param_type =
                                        htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                    ph->param_length =
                                        htons(SCTP_BUF_LEN(oper));
                                    ippp = (uint32_t *) (ph + 1);
                                    *ippp = htonl(SCTP_FROM_SCTP_INDATA + SCTP_LOC_5);
                                    ippp++;
                                    *ippp = chk->rec.data.TSN_seq;
                                    ippp++;
                                    *ippp = ((chk->rec.data.stream_number << 16) | chk->rec.data.stream_seq);

                              }
                              stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_5;
                              sctp_abort_an_association(stcb->sctp_ep,
                                  stcb, SCTP_PEER_FAULTY, oper, SCTP_SO_NOT_LOCKED);
                              *abort_flag = 1;
                        }
                  }
            }
            return;
      }
      /* Find its place */
      TAILQ_FOREACH(at, &asoc->reasmqueue, sctp_next) {
            if (compare_with_wrap(at->rec.data.TSN_seq,
                chk->rec.data.TSN_seq, MAX_TSN)) {
                  /*
                   * one in queue is bigger than the new one, insert
                   * before this one
                   */
                  /* A check */
                  asoc->size_on_reasm_queue += chk->send_size;
                  sctp_ucount_incr(asoc->cnt_on_reasm_queue);
                  next = at;
                  TAILQ_INSERT_BEFORE(at, chk, sctp_next);
                  break;
            } else if (at->rec.data.TSN_seq == chk->rec.data.TSN_seq) {
                  /* Gak, He sent me a duplicate str seq number */
                  /*
                   * foo bar, I guess I will just free this new guy,
                   * should we abort too? FIX ME MAYBE? Or it COULD be
                   * that the SSN's have wrapped. Maybe I should
                   * compare to TSN somehow... sigh for now just blow
                   * away the chunk!
                   */
                  if (chk->data) {
                        sctp_m_freem(chk->data);
                        chk->data = NULL;
                  }
                  sctp_free_a_chunk(stcb, chk);
                  return;
            } else {
                  last_flags = at->rec.data.rcv_flags;
                  last_tsn = at->rec.data.TSN_seq;
                  prev = at;
                  if (TAILQ_NEXT(at, sctp_next) == NULL) {
                        /*
                         * We are at the end, insert it after this
                         * one
                         */
                        /* check it first */
                        asoc->size_on_reasm_queue += chk->send_size;
                        sctp_ucount_incr(asoc->cnt_on_reasm_queue);
                        TAILQ_INSERT_AFTER(&asoc->reasmqueue, at, chk, sctp_next);
                        break;
                  }
            }
      }
      /* Now the audits */
      if (prev) {
            prev_tsn = chk->rec.data.TSN_seq - 1;
            if (prev_tsn == prev->rec.data.TSN_seq) {
                  /*
                   * Ok the one I am dropping onto the end is the
                   * NEXT. A bit of valdiation here.
                   */
                  if ((prev->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) ==
                      SCTP_DATA_FIRST_FRAG ||
                      (prev->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) ==
                      SCTP_DATA_MIDDLE_FRAG) {
                        /*
                         * Insert chk MUST be a MIDDLE or LAST
                         * fragment
                         */
                        if ((chk->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) ==
                            SCTP_DATA_FIRST_FRAG) {
                              SCTPDBG(SCTP_DEBUG_INDATA1, "Prev check - It can be a midlle or last but not a first\n");
                              SCTPDBG(SCTP_DEBUG_INDATA1, "Gak, Evil plot, it's a FIRST!\n");
                              oper = sctp_get_mbuf_for_msg((sizeof(struct sctp_paramhdr) + 3 * sizeof(uint32_t)),
                                  0, M_DONTWAIT, 1, MT_DATA);
                              if (oper) {
                                    struct sctp_paramhdr *ph;
                                    uint32_t *ippp;

                                    SCTP_BUF_LEN(oper) =
                                        sizeof(struct sctp_paramhdr) +
                                        (3 * sizeof(uint32_t));
                                    ph = mtod(oper,
                                        struct sctp_paramhdr *);
                                    ph->param_type =
                                        htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                    ph->param_length =
                                        htons(SCTP_BUF_LEN(oper));
                                    ippp = (uint32_t *) (ph + 1);
                                    *ippp = htonl(SCTP_FROM_SCTP_INDATA + SCTP_LOC_6);
                                    ippp++;
                                    *ippp = chk->rec.data.TSN_seq;
                                    ippp++;
                                    *ippp = ((chk->rec.data.stream_number << 16) | chk->rec.data.stream_seq);

                              }
                              stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_6;
                              sctp_abort_an_association(stcb->sctp_ep,
                                  stcb, SCTP_PEER_FAULTY, oper, SCTP_SO_NOT_LOCKED);
                              *abort_flag = 1;
                              return;
                        }
                        if (chk->rec.data.stream_number !=
                            prev->rec.data.stream_number) {
                              /*
                               * Huh, need the correct STR here,
                               * they must be the same.
                               */
                              SCTP_PRINTF("Prev check - Gak, Evil plot, ssn:%d not the same as at:%d\n",
                                  chk->rec.data.stream_number,
                                  prev->rec.data.stream_number);
                              oper = sctp_get_mbuf_for_msg((sizeof(struct sctp_paramhdr) + 3 * sizeof(uint32_t)),
                                  0, M_DONTWAIT, 1, MT_DATA);
                              if (oper) {
                                    struct sctp_paramhdr *ph;
                                    uint32_t *ippp;

                                    SCTP_BUF_LEN(oper) =
                                        sizeof(struct sctp_paramhdr) +
                                        (3 * sizeof(uint32_t));
                                    ph = mtod(oper,
                                        struct sctp_paramhdr *);
                                    ph->param_type =
                                        htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                    ph->param_length =
                                        htons(SCTP_BUF_LEN(oper));
                                    ippp = (uint32_t *) (ph + 1);
                                    *ippp = htonl(SCTP_FROM_SCTP_INDATA + SCTP_LOC_7);
                                    ippp++;
                                    *ippp = chk->rec.data.TSN_seq;
                                    ippp++;
                                    *ippp = ((chk->rec.data.stream_number << 16) | chk->rec.data.stream_seq);
                              }
                              stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_7;
                              sctp_abort_an_association(stcb->sctp_ep,
                                  stcb, SCTP_PEER_FAULTY, oper, SCTP_SO_NOT_LOCKED);

                              *abort_flag = 1;
                              return;
                        }
                        if ((prev->rec.data.rcv_flags & SCTP_DATA_UNORDERED) == 0 &&
                            chk->rec.data.stream_seq !=
                            prev->rec.data.stream_seq) {
                              /*
                               * Huh, need the correct STR here,
                               * they must be the same.
                               */
                              SCTPDBG(SCTP_DEBUG_INDATA1, "Prev check - Gak, Evil plot, sseq:%d not the same as at:%d\n",
                                  chk->rec.data.stream_seq,
                                  prev->rec.data.stream_seq);
                              oper = sctp_get_mbuf_for_msg((sizeof(struct sctp_paramhdr) + 3 * sizeof(uint32_t)),
                                  0, M_DONTWAIT, 1, MT_DATA);
                              if (oper) {
                                    struct sctp_paramhdr *ph;
                                    uint32_t *ippp;

                                    SCTP_BUF_LEN(oper) =
                                        sizeof(struct sctp_paramhdr) +
                                        (3 * sizeof(uint32_t));
                                    ph = mtod(oper,
                                        struct sctp_paramhdr *);
                                    ph->param_type =
                                        htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                    ph->param_length =
                                        htons(SCTP_BUF_LEN(oper));
                                    ippp = (uint32_t *) (ph + 1);
                                    *ippp = htonl(SCTP_FROM_SCTP_INDATA + SCTP_LOC_8);
                                    ippp++;
                                    *ippp = chk->rec.data.TSN_seq;
                                    ippp++;
                                    *ippp = ((chk->rec.data.stream_number << 16) | chk->rec.data.stream_seq);
                              }
                              stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_8;
                              sctp_abort_an_association(stcb->sctp_ep,
                                  stcb, SCTP_PEER_FAULTY, oper, SCTP_SO_NOT_LOCKED);

                              *abort_flag = 1;
                              return;
                        }
                  } else if ((prev->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) ==
                      SCTP_DATA_LAST_FRAG) {
                        /* Insert chk MUST be a FIRST */
                        if ((chk->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) !=
                            SCTP_DATA_FIRST_FRAG) {
                              SCTPDBG(SCTP_DEBUG_INDATA1, "Prev check - Gak, evil plot, its not FIRST and it must be!\n");
                              oper = sctp_get_mbuf_for_msg((sizeof(struct sctp_paramhdr) + 3 * sizeof(uint32_t)),
                                  0, M_DONTWAIT, 1, MT_DATA);
                              if (oper) {
                                    struct sctp_paramhdr *ph;
                                    uint32_t *ippp;

                                    SCTP_BUF_LEN(oper) =
                                        sizeof(struct sctp_paramhdr) +
                                        (3 * sizeof(uint32_t));
                                    ph = mtod(oper,
                                        struct sctp_paramhdr *);
                                    ph->param_type =
                                        htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                    ph->param_length =
                                        htons(SCTP_BUF_LEN(oper));
                                    ippp = (uint32_t *) (ph + 1);
                                    *ippp = htonl(SCTP_FROM_SCTP_INDATA + SCTP_LOC_9);
                                    ippp++;
                                    *ippp = chk->rec.data.TSN_seq;
                                    ippp++;
                                    *ippp = ((chk->rec.data.stream_number << 16) | chk->rec.data.stream_seq);

                              }
                              stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_9;
                              sctp_abort_an_association(stcb->sctp_ep,
                                  stcb, SCTP_PEER_FAULTY, oper, SCTP_SO_NOT_LOCKED);

                              *abort_flag = 1;
                              return;
                        }
                  }
            }
      }
      if (next) {
            post_tsn = chk->rec.data.TSN_seq + 1;
            if (post_tsn == next->rec.data.TSN_seq) {
                  /*
                   * Ok the one I am inserting ahead of is my NEXT
                   * one. A bit of valdiation here.
                   */
                  if (next->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) {
                        /* Insert chk MUST be a last fragment */
                        if ((chk->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK)
                            != SCTP_DATA_LAST_FRAG) {
                              SCTPDBG(SCTP_DEBUG_INDATA1, "Next chk - Next is FIRST, we must be LAST\n");
                              SCTPDBG(SCTP_DEBUG_INDATA1, "Gak, Evil plot, its not a last!\n");
                              oper = sctp_get_mbuf_for_msg((sizeof(struct sctp_paramhdr) + 3 * sizeof(uint32_t)),
                                  0, M_DONTWAIT, 1, MT_DATA);
                              if (oper) {
                                    struct sctp_paramhdr *ph;
                                    uint32_t *ippp;

                                    SCTP_BUF_LEN(oper) =
                                        sizeof(struct sctp_paramhdr) +
                                        (3 * sizeof(uint32_t));
                                    ph = mtod(oper,
                                        struct sctp_paramhdr *);
                                    ph->param_type =
                                        htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                    ph->param_length =
                                        htons(SCTP_BUF_LEN(oper));
                                    ippp = (uint32_t *) (ph + 1);
                                    *ippp = htonl(SCTP_FROM_SCTP_INDATA + SCTP_LOC_10);
                                    ippp++;
                                    *ippp = chk->rec.data.TSN_seq;
                                    ippp++;
                                    *ippp = ((chk->rec.data.stream_number << 16) | chk->rec.data.stream_seq);
                              }
                              stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_10;
                              sctp_abort_an_association(stcb->sctp_ep,
                                  stcb, SCTP_PEER_FAULTY, oper, SCTP_SO_NOT_LOCKED);

                              *abort_flag = 1;
                              return;
                        }
                  } else if ((next->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) ==
                            SCTP_DATA_MIDDLE_FRAG ||
                            (next->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) ==
                      SCTP_DATA_LAST_FRAG) {
                        /*
                         * Insert chk CAN be MIDDLE or FIRST NOT
                         * LAST
                         */
                        if ((chk->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) ==
                            SCTP_DATA_LAST_FRAG) {
                              SCTPDBG(SCTP_DEBUG_INDATA1, "Next chk - Next is a MIDDLE/LAST\n");
                              SCTPDBG(SCTP_DEBUG_INDATA1, "Gak, Evil plot, new prev chunk is a LAST\n");
                              oper = sctp_get_mbuf_for_msg((sizeof(struct sctp_paramhdr) + 3 * sizeof(uint32_t)),
                                  0, M_DONTWAIT, 1, MT_DATA);
                              if (oper) {
                                    struct sctp_paramhdr *ph;
                                    uint32_t *ippp;

                                    SCTP_BUF_LEN(oper) =
                                        sizeof(struct sctp_paramhdr) +
                                        (3 * sizeof(uint32_t));
                                    ph = mtod(oper,
                                        struct sctp_paramhdr *);
                                    ph->param_type =
                                        htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                    ph->param_length =
                                        htons(SCTP_BUF_LEN(oper));
                                    ippp = (uint32_t *) (ph + 1);
                                    *ippp = htonl(SCTP_FROM_SCTP_INDATA + SCTP_LOC_11);
                                    ippp++;
                                    *ippp = chk->rec.data.TSN_seq;
                                    ippp++;
                                    *ippp = ((chk->rec.data.stream_number << 16) | chk->rec.data.stream_seq);

                              }
                              stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_11;
                              sctp_abort_an_association(stcb->sctp_ep,
                                  stcb, SCTP_PEER_FAULTY, oper, SCTP_SO_NOT_LOCKED);

                              *abort_flag = 1;
                              return;
                        }
                        if (chk->rec.data.stream_number !=
                            next->rec.data.stream_number) {
                              /*
                               * Huh, need the correct STR here,
                               * they must be the same.
                               */
                              SCTPDBG(SCTP_DEBUG_INDATA1, "Next chk - Gak, Evil plot, ssn:%d not the same as at:%d\n",
                                  chk->rec.data.stream_number,
                                  next->rec.data.stream_number);
                              oper = sctp_get_mbuf_for_msg((sizeof(struct sctp_paramhdr) + 3 * sizeof(uint32_t)),
                                  0, M_DONTWAIT, 1, MT_DATA);
                              if (oper) {
                                    struct sctp_paramhdr *ph;
                                    uint32_t *ippp;

                                    SCTP_BUF_LEN(oper) =
                                        sizeof(struct sctp_paramhdr) +
                                        (3 * sizeof(uint32_t));
                                    ph = mtod(oper,
                                        struct sctp_paramhdr *);
                                    ph->param_type =
                                        htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                    ph->param_length =
                                        htons(SCTP_BUF_LEN(oper));
                                    ippp = (uint32_t *) (ph + 1);
                                    *ippp = htonl(SCTP_FROM_SCTP_INDATA + SCTP_LOC_12);
                                    ippp++;
                                    *ippp = chk->rec.data.TSN_seq;
                                    ippp++;
                                    *ippp = ((chk->rec.data.stream_number << 16) | chk->rec.data.stream_seq);

                              }
                              stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_12;
                              sctp_abort_an_association(stcb->sctp_ep,
                                  stcb, SCTP_PEER_FAULTY, oper, SCTP_SO_NOT_LOCKED);

                              *abort_flag = 1;
                              return;
                        }
                        if ((next->rec.data.rcv_flags & SCTP_DATA_UNORDERED) == 0 &&
                            chk->rec.data.stream_seq !=
                            next->rec.data.stream_seq) {
                              /*
                               * Huh, need the correct STR here,
                               * they must be the same.
                               */
                              SCTPDBG(SCTP_DEBUG_INDATA1, "Next chk - Gak, Evil plot, sseq:%d not the same as at:%d\n",
                                  chk->rec.data.stream_seq,
                                  next->rec.data.stream_seq);
                              oper = sctp_get_mbuf_for_msg((sizeof(struct sctp_paramhdr) + 3 * sizeof(uint32_t)),
                                  0, M_DONTWAIT, 1, MT_DATA);
                              if (oper) {
                                    struct sctp_paramhdr *ph;
                                    uint32_t *ippp;

                                    SCTP_BUF_LEN(oper) =
                                        sizeof(struct sctp_paramhdr) +
                                        (3 * sizeof(uint32_t));
                                    ph = mtod(oper,
                                        struct sctp_paramhdr *);
                                    ph->param_type =
                                        htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                    ph->param_length =
                                        htons(SCTP_BUF_LEN(oper));
                                    ippp = (uint32_t *) (ph + 1);
                                    *ippp = htonl(SCTP_FROM_SCTP_INDATA + SCTP_LOC_13);
                                    ippp++;
                                    *ippp = chk->rec.data.TSN_seq;
                                    ippp++;
                                    *ippp = ((chk->rec.data.stream_number << 16) | chk->rec.data.stream_seq);
                              }
                              stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_13;
                              sctp_abort_an_association(stcb->sctp_ep,
                                  stcb, SCTP_PEER_FAULTY, oper, SCTP_SO_NOT_LOCKED);

                              *abort_flag = 1;
                              return;
                        }
                  }
            }
      }
      /* Do we need to do some delivery? check */
      sctp_deliver_reasm_check(stcb, asoc);
}

/*
 * This is an unfortunate routine. It checks to make sure a evil guy is not
 * stuffing us full of bad packet fragments. A broken peer could also do this
 * but this is doubtful. It is to bad I must worry about evil crackers sigh
 * :< more cycles.
 */
static int
sctp_does_tsn_belong_to_reasm(struct sctp_association *asoc,
    uint32_t TSN_seq)
{
      struct sctp_tmit_chunk *at;
      uint32_t tsn_est;

      TAILQ_FOREACH(at, &asoc->reasmqueue, sctp_next) {
            if (compare_with_wrap(TSN_seq,
                at->rec.data.TSN_seq, MAX_TSN)) {
                  /* is it one bigger? */
                  tsn_est = at->rec.data.TSN_seq + 1;
                  if (tsn_est == TSN_seq) {
                        /* yep. It better be a last then */
                        if ((at->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) !=
                            SCTP_DATA_LAST_FRAG) {
                              /*
                               * Ok this guy belongs next to a guy
                               * that is NOT last, it should be a
                               * middle/last, not a complete
                               * chunk.
                               */
                              return (1);
                        } else {
                              /*
                               * This guy is ok since its a LAST
                               * and the new chunk is a fully
                               * self- contained one.
                               */
                              return (0);
                        }
                  }
            } else if (TSN_seq == at->rec.data.TSN_seq) {
                  /* Software error since I have a dup? */
                  return (1);
            } else {
                  /*
                   * Ok, 'at' is larger than new chunk but does it
                   * need to be right before it.
                   */
                  tsn_est = TSN_seq + 1;
                  if (tsn_est == at->rec.data.TSN_seq) {
                        /* Yep, It better be a first */
                        if ((at->rec.data.rcv_flags & SCTP_DATA_FRAG_MASK) !=
                            SCTP_DATA_FIRST_FRAG) {
                              return (1);
                        } else {
                              return (0);
                        }
                  }
            }
      }
      return (0);
}


static int
sctp_process_a_data_chunk(struct sctp_tcb *stcb, struct sctp_association *asoc,
    struct mbuf **m, int offset, struct sctp_data_chunk *ch, int chk_length,
    struct sctp_nets *net, uint32_t * high_tsn, int *abort_flag,
    int *break_flag, int last_chunk)
{
      /* Process a data chunk */
      /* struct sctp_tmit_chunk *chk; */
      struct sctp_tmit_chunk *chk;
      uint32_t tsn, gap;
      struct mbuf *dmbuf;
      int indx, the_len;
      int need_reasm_check = 0;
      uint16_t strmno, strmseq;
      struct mbuf *oper;
      struct sctp_queued_to_read *control;
      int ordered;
      uint32_t protocol_id;
      uint8_t chunk_flags;
      struct sctp_stream_reset_list *liste;

      chk = NULL;
      tsn = ntohl(ch->dp.tsn);
      chunk_flags = ch->ch.chunk_flags;
      protocol_id = ch->dp.protocol_id;
      ordered = ((ch->ch.chunk_flags & SCTP_DATA_UNORDERED) == 0);
      if (sctp_logging_level & SCTP_MAP_LOGGING_ENABLE) {
            sctp_log_map(tsn, asoc->cumulative_tsn, asoc->highest_tsn_inside_map, SCTP_MAP_TSN_ENTERS);
      }
      if (stcb == NULL) {
            return (0);
      }
      SCTP_LTRACE_CHK(stcb->sctp_ep, stcb, ch->ch.chunk_type, tsn);
      if (compare_with_wrap(asoc->cumulative_tsn, tsn, MAX_TSN) ||
          asoc->cumulative_tsn == tsn) {
            /* It is a duplicate */
            SCTP_STAT_INCR(sctps_recvdupdata);
            if (asoc->numduptsns < SCTP_MAX_DUP_TSNS) {
                  /* Record a dup for the next outbound sack */
                  asoc->dup_tsns[asoc->numduptsns] = tsn;
                  asoc->numduptsns++;
            }
            asoc->send_sack = 1;
            return (0);
      }
      /* Calculate the number of TSN's between the base and this TSN */
      if (tsn >= asoc->mapping_array_base_tsn) {
            gap = tsn - asoc->mapping_array_base_tsn;
      } else {
            gap = (MAX_TSN - asoc->mapping_array_base_tsn) + tsn + 1;
      }
      if (gap >= (SCTP_MAPPING_ARRAY << 3)) {
            /* Can't hold the bit in the mapping at max array, toss it */
            return (0);
      }
      if (gap >= (uint32_t) (asoc->mapping_array_size << 3)) {
            SCTP_TCB_LOCK_ASSERT(stcb);
            if (sctp_expand_mapping_array(asoc, gap)) {
                  /* Can't expand, drop it */
                  return (0);
            }
      }
      if (compare_with_wrap(tsn, *high_tsn, MAX_TSN)) {
            *high_tsn = tsn;
      }
      /* See if we have received this one already */
      if (SCTP_IS_TSN_PRESENT(asoc->mapping_array, gap)) {
            SCTP_STAT_INCR(sctps_recvdupdata);
            if (asoc->numduptsns < SCTP_MAX_DUP_TSNS) {
                  /* Record a dup for the next outbound sack */
                  asoc->dup_tsns[asoc->numduptsns] = tsn;
                  asoc->numduptsns++;
            }
            asoc->send_sack = 1;
            return (0);
      }
      /*
       * Check to see about the GONE flag, duplicates would cause a sack
       * to be sent up above
       */
      if (((stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE) ||
          (stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_SOCKET_ALLGONE) ||
          (stcb->asoc.state & SCTP_STATE_CLOSED_SOCKET))
          ) {
            /*
             * wait a minute, this guy is gone, there is no longer a
             * receiver. Send peer an ABORT!
             */
            struct mbuf *op_err;

            op_err = sctp_generate_invmanparam(SCTP_CAUSE_OUT_OF_RESC);
            sctp_abort_an_association(stcb->sctp_ep, stcb, 0, op_err, SCTP_SO_NOT_LOCKED);
            *abort_flag = 1;
            return (0);
      }
      /*
       * Now before going further we see if there is room. If NOT then we
       * MAY let one through only IF this TSN is the one we are waiting
       * for on a partial delivery API.
       */

      /* now do the tests */
      if (((asoc->cnt_on_all_streams +
          asoc->cnt_on_reasm_queue +
          asoc->cnt_msg_on_sb) > sctp_max_chunks_on_queue) ||
          (((int)asoc->my_rwnd) <= 0)) {
            /*
             * When we have NO room in the rwnd we check to make sure
             * the reader is doing its job...
             */
            if (stcb->sctp_socket->so_rcv.sb_cc) {
                  /* some to read, wake-up */
#if defined (__APPLE__) || defined(SCTP_SO_LOCK_TESTING)
                  struct socket *so;

                  so = SCTP_INP_SO(stcb->sctp_ep);
                  atomic_add_int(&stcb->asoc.refcnt, 1);
                  SCTP_TCB_UNLOCK(stcb);
                  SCTP_SOCKET_LOCK(so, 1);
                  SCTP_TCB_LOCK(stcb);
                  atomic_subtract_int(&stcb->asoc.refcnt, 1);
                  if (stcb->asoc.state & SCTP_STATE_CLOSED_SOCKET) {
                        /* assoc was freed while we were unlocked */
                        SCTP_SOCKET_UNLOCK(so, 1);
                        return (0);
                  }
#endif
                  sctp_sorwakeup(stcb->sctp_ep, stcb->sctp_socket);
#if defined (__APPLE__) || defined(SCTP_SO_LOCK_TESTING)
                  SCTP_SOCKET_UNLOCK(so, 1);
#endif
            }
            /* now is it in the mapping array of what we have accepted? */
            if (compare_with_wrap(tsn,
                asoc->highest_tsn_inside_map, MAX_TSN)) {

                  /* Nope not in the valid range dump it */
                  sctp_set_rwnd(stcb, asoc);
                  if ((asoc->cnt_on_all_streams +
                      asoc->cnt_on_reasm_queue +
                      asoc->cnt_msg_on_sb) > sctp_max_chunks_on_queue) {
                        SCTP_STAT_INCR(sctps_datadropchklmt);
                  } else {
                        SCTP_STAT_INCR(sctps_datadroprwnd);
                  }
                  indx = *break_flag;
                  *break_flag = 1;
                  return (0);
            }
      }
      strmno = ntohs(ch->dp.stream_id);
      if (strmno >= asoc->streamincnt) {
            struct sctp_paramhdr *phdr;
            struct mbuf *mb;

            mb = sctp_get_mbuf_for_msg((sizeof(struct sctp_paramhdr) * 2),
                0, M_DONTWAIT, 1, MT_DATA);
            if (mb != NULL) {
                  /* add some space up front so prepend will work well */
                  SCTP_BUF_RESV_UF(mb, sizeof(struct sctp_chunkhdr));
                  phdr = mtod(mb, struct sctp_paramhdr *);
                  /*
                   * Error causes are just param's and this one has
                   * two back to back phdr, one with the error type
                   * and size, the other with the streamid and a rsvd
                   */
                  SCTP_BUF_LEN(mb) = (sizeof(struct sctp_paramhdr) * 2);
                  phdr->param_type = htons(SCTP_CAUSE_INVALID_STREAM);
                  phdr->param_length =
                      htons(sizeof(struct sctp_paramhdr) * 2);
                  phdr++;
                  /* We insert the stream in the type field */
                  phdr->param_type = ch->dp.stream_id;
                  /* And set the length to 0 for the rsvd field */
                  phdr->param_length = 0;
                  sctp_queue_op_err(stcb, mb);
            }
            SCTP_STAT_INCR(sctps_badsid);
            SCTP_TCB_LOCK_ASSERT(stcb);
            SCTP_SET_TSN_PRESENT(asoc->mapping_array, gap);
            if (compare_with_wrap(tsn, asoc->highest_tsn_inside_map, MAX_TSN)) {
                  /* we have a new high score */
                  asoc->highest_tsn_inside_map = tsn;
                  if (sctp_logging_level & SCTP_MAP_LOGGING_ENABLE) {
                        sctp_log_map(0, 2, asoc->highest_tsn_inside_map, SCTP_MAP_SLIDE_RESULT);
                  }
            }
            if (tsn == (asoc->cumulative_tsn + 1)) {
                  /* Update cum-ack */
                  asoc->cumulative_tsn = tsn;
            }
            return (0);
      }
      /*
       * Before we continue lets validate that we are not being fooled by
       * an evil attacker. We can only have 4k chunks based on our TSN
       * spread allowed by the mapping array 512 * 8 bits, so there is no
       * way our stream sequence numbers could have wrapped. We of course
       * only validate the FIRST fragment so the bit must be set.
       */
      strmseq = ntohs(ch->dp.stream_sequence);
#ifdef SCTP_ASOCLOG_OF_TSNS
      SCTP_TCB_LOCK_ASSERT(stcb);
      if (asoc->tsn_in_at >= SCTP_TSN_LOG_SIZE) {
            asoc->tsn_in_at = 0;
            asoc->tsn_in_wrapped = 1;
      }
      asoc->in_tsnlog[asoc->tsn_in_at].tsn = tsn;
      asoc->in_tsnlog[asoc->tsn_in_at].strm = strmno;
      asoc->in_tsnlog[asoc->tsn_in_at].seq = strmseq;
      asoc->in_tsnlog[asoc->tsn_in_at].sz = chk_length;
      asoc->in_tsnlog[asoc->tsn_in_at].flgs = chunk_flags;
      asoc->in_tsnlog[asoc->tsn_in_at].stcb = (void *)stcb;
      asoc->in_tsnlog[asoc->tsn_in_at].in_pos = asoc->tsn_in_at;
      asoc->in_tsnlog[asoc->tsn_in_at].in_out = 1;
      asoc->tsn_in_at++;
#endif
      if ((chunk_flags & SCTP_DATA_FIRST_FRAG) &&
          (TAILQ_EMPTY(&asoc->resetHead)) &&
          (chunk_flags & SCTP_DATA_UNORDERED) == 0 &&
          (compare_with_wrap(asoc->strmin[strmno].last_sequence_delivered,
          strmseq, MAX_SEQ) ||
          asoc->strmin[strmno].last_sequence_delivered == strmseq)) {
            /* The incoming sseq is behind where we last delivered? */
            SCTPDBG(SCTP_DEBUG_INDATA1, "EVIL/Broken-Dup S-SEQ:%d delivered:%d from peer, Abort!\n",
                strmseq, asoc->strmin[strmno].last_sequence_delivered);
            oper = sctp_get_mbuf_for_msg((sizeof(struct sctp_paramhdr) + 3 * sizeof(uint32_t)),
                0, M_DONTWAIT, 1, MT_DATA);
            if (oper) {
                  struct sctp_paramhdr *ph;
                  uint32_t *ippp;

                  SCTP_BUF_LEN(oper) = sizeof(struct sctp_paramhdr) +
                      (3 * sizeof(uint32_t));
                  ph = mtod(oper, struct sctp_paramhdr *);
                  ph->param_type = htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                  ph->param_length = htons(SCTP_BUF_LEN(oper));
                  ippp = (uint32_t *) (ph + 1);
                  *ippp = htonl(SCTP_FROM_SCTP_INDATA + SCTP_LOC_14);
                  ippp++;
                  *ippp = tsn;
                  ippp++;
                  *ippp = ((strmno << 16) | strmseq);

            }
            stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_14;
            sctp_abort_an_association(stcb->sctp_ep, stcb,
                SCTP_PEER_FAULTY, oper, SCTP_SO_NOT_LOCKED);
            *abort_flag = 1;
            return (0);
      }
      /************************************
       * From here down we may find ch-> invalid
       * so its a good idea NOT to use it.
       *************************************/

      the_len = (chk_length - sizeof(struct sctp_data_chunk));
      if (last_chunk == 0) {
            dmbuf = SCTP_M_COPYM(*m,
                (offset + sizeof(struct sctp_data_chunk)),
                the_len, M_DONTWAIT);
#ifdef SCTP_MBUF_LOGGING
            if (sctp_logging_level & SCTP_MBUF_LOGGING_ENABLE) {
                  struct mbuf *mat;

                  mat = dmbuf;
                  while (mat) {
                        if (SCTP_BUF_IS_EXTENDED(mat)) {
                              sctp_log_mb(mat, SCTP_MBUF_ICOPY);
                        }
                        mat = SCTP_BUF_NEXT(mat);
                  }
            }
#endif
      } else {
            /* We can steal the last chunk */
            int l_len;

            dmbuf = *m;
            /* lop off the top part */
            m_adj(dmbuf, (offset + sizeof(struct sctp_data_chunk)));
            if (SCTP_BUF_NEXT(dmbuf) == NULL) {
                  l_len = SCTP_BUF_LEN(dmbuf);
            } else {
                  /*
                   * need to count up the size hopefully does not hit
                   * this to often :-0
                   */
                  struct mbuf *lat;

                  l_len = 0;
                  lat = dmbuf;
                  while (lat) {
                        l_len += SCTP_BUF_LEN(lat);
                        lat = SCTP_BUF_NEXT(lat);
                  }
            }
            if (l_len > the_len) {
                  /* Trim the end round bytes off  too */
                  m_adj(dmbuf, -(l_len - the_len));
            }
      }
      if (dmbuf == NULL) {
            SCTP_STAT_INCR(sctps_nomem);
            return (0);
      }
      if ((chunk_flags & SCTP_DATA_NOT_FRAG) == SCTP_DATA_NOT_FRAG &&
          asoc->fragmented_delivery_inprogress == 0 &&
          TAILQ_EMPTY(&asoc->resetHead) &&
          ((ordered == 0) ||
          ((asoc->strmin[strmno].last_sequence_delivered + 1) == strmseq &&
          TAILQ_EMPTY(&asoc->strmin[strmno].inqueue)))) {
            /* Candidate for express delivery */
            /*
             * Its not fragmented, No PD-API is up, Nothing in the
             * delivery queue, Its un-ordered OR ordered and the next to
             * deliver AND nothing else is stuck on the stream queue,
             * And there is room for it in the socket buffer. Lets just
             * stuff it up the buffer....
             */

            /* It would be nice to avoid this copy if we could :< */
            sctp_alloc_a_readq(stcb, control);
            sctp_build_readq_entry_mac(control, stcb, asoc->context, net, tsn,
                protocol_id,
                stcb->asoc.context,
                strmno, strmseq,
                chunk_flags,
                dmbuf);
            if (control == NULL) {
                  goto failed_express_del;
            }
            sctp_add_to_readq(stcb->sctp_ep, stcb, control, &stcb->sctp_socket->so_rcv, 1, SCTP_SO_NOT_LOCKED);
            if ((chunk_flags & SCTP_DATA_UNORDERED) == 0) {
                  /* for ordered, bump what we delivered */
                  asoc->strmin[strmno].last_sequence_delivered++;
            }
            SCTP_STAT_INCR(sctps_recvexpress);
            if (sctp_logging_level & SCTP_STR_LOGGING_ENABLE) {
                  sctp_log_strm_del_alt(stcb, tsn, strmseq, strmno,
                      SCTP_STR_LOG_FROM_EXPRS_DEL);
            }
            control = NULL;
            goto finish_express_del;
      }
failed_express_del:
      /* If we reach here this is a new chunk */
      chk = NULL;
      control = NULL;
      /* Express for fragmented delivery? */
      if ((asoc->fragmented_delivery_inprogress) &&
          (stcb->asoc.control_pdapi) &&
          (asoc->str_of_pdapi == strmno) &&
          (asoc->ssn_of_pdapi == strmseq)
          ) {
            control = stcb->asoc.control_pdapi;
            if ((chunk_flags & SCTP_DATA_FIRST_FRAG) == SCTP_DATA_FIRST_FRAG) {
                  /* Can't be another first? */
                  goto failed_pdapi_express_del;
            }
            if (tsn == (control->sinfo_tsn + 1)) {
                  /* Yep, we can add it on */
                  int end = 0;
                  uint32_t cumack;

                  if (chunk_flags & SCTP_DATA_LAST_FRAG) {
                        end = 1;
                  }
                  cumack = asoc->cumulative_tsn;
                  if ((cumack + 1) == tsn)
                        cumack = tsn;

                  if (sctp_append_to_readq(stcb->sctp_ep, stcb, control, dmbuf, end,
                      tsn,
                      &stcb->sctp_socket->so_rcv)) {
                        SCTP_PRINTF("Append fails end:%d\n", end);
                        goto failed_pdapi_express_del;
                  }
                  SCTP_STAT_INCR(sctps_recvexpressm);
                  control->sinfo_tsn = tsn;
                  asoc->tsn_last_delivered = tsn;
                  asoc->fragment_flags = chunk_flags;
                  asoc->tsn_of_pdapi_last_delivered = tsn;
                  asoc->last_flags_delivered = chunk_flags;
                  asoc->last_strm_seq_delivered = strmseq;
                  asoc->last_strm_no_delivered = strmno;
                  if (end) {
                        /* clean up the flags and such */
                        asoc->fragmented_delivery_inprogress = 0;
                        if ((chunk_flags & SCTP_DATA_UNORDERED) == 0) {
                              asoc->strmin[strmno].last_sequence_delivered++;
                        }
                        stcb->asoc.control_pdapi = NULL;
                        if (TAILQ_EMPTY(&asoc->reasmqueue) == 0) {
                              /*
                               * There could be another message
                               * ready
                               */
                              need_reasm_check = 1;
                        }
                  }
                  control = NULL;
                  goto finish_express_del;
            }
      }
failed_pdapi_express_del:
      control = NULL;
      if ((chunk_flags & SCTP_DATA_NOT_FRAG) != SCTP_DATA_NOT_FRAG) {
            sctp_alloc_a_chunk(stcb, chk);
            if (chk == NULL) {
                  /* No memory so we drop the chunk */
                  SCTP_STAT_INCR(sctps_nomem);
                  if (last_chunk == 0) {
                        /* we copied it, free the copy */
                        sctp_m_freem(dmbuf);
                  }
                  return (0);
            }
            chk->rec.data.TSN_seq = tsn;
            chk->no_fr_allowed = 0;
            chk->rec.data.stream_seq = strmseq;
            chk->rec.data.stream_number = strmno;
            chk->rec.data.payloadtype = protocol_id;
            chk->rec.data.context = stcb->asoc.context;
            chk->rec.data.doing_fast_retransmit = 0;
            chk->rec.data.rcv_flags = chunk_flags;
            chk->asoc = asoc;
            chk->send_size = the_len;
            chk->whoTo = net;
            atomic_add_int(&net->ref_count, 1);
            chk->data = dmbuf;
      } else {
            sctp_alloc_a_readq(stcb, control);
            sctp_build_readq_entry_mac(control, stcb, asoc->context, net, tsn,
                protocol_id,
                stcb->asoc.context,
                strmno, strmseq,
                chunk_flags,
                dmbuf);
            if (control == NULL) {
                  /* No memory so we drop the chunk */
                  SCTP_STAT_INCR(sctps_nomem);
                  if (last_chunk == 0) {
                        /* we copied it, free the copy */
                        sctp_m_freem(dmbuf);
                  }
                  return (0);
            }
            control->length = the_len;
      }

      /* Mark it as received */
      /* Now queue it where it belongs */
      if (control != NULL) {
            /* First a sanity check */
            if (asoc->fragmented_delivery_inprogress) {
                  /*
                   * Ok, we have a fragmented delivery in progress if
                   * this chunk is next to deliver OR belongs in our
                   * view to the reassembly, the peer is evil or
                   * broken.
                   */
                  uint32_t estimate_tsn;

                  estimate_tsn = asoc->tsn_last_delivered + 1;
                  if (TAILQ_EMPTY(&asoc->reasmqueue) &&
                      (estimate_tsn == control->sinfo_tsn)) {
                        /* Evil/Broke peer */
                        sctp_m_freem(control->data);
                        control->data = NULL;
                        if (control->whoFrom) {
                              sctp_free_remote_addr(control->whoFrom);
                              control->whoFrom = NULL;
                        }
                        sctp_free_a_readq(stcb, control);
                        oper = sctp_get_mbuf_for_msg((sizeof(struct sctp_paramhdr) + 3 * sizeof(uint32_t)),
                            0, M_DONTWAIT, 1, MT_DATA);
                        if (oper) {
                              struct sctp_paramhdr *ph;
                              uint32_t *ippp;

                              SCTP_BUF_LEN(oper) =
                                  sizeof(struct sctp_paramhdr) +
                                  (3 * sizeof(uint32_t));
                              ph = mtod(oper, struct sctp_paramhdr *);
                              ph->param_type =
                                  htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                              ph->param_length = htons(SCTP_BUF_LEN(oper));
                              ippp = (uint32_t *) (ph + 1);
                              *ippp = htonl(SCTP_FROM_SCTP_INDATA + SCTP_LOC_15);
                              ippp++;
                              *ippp = tsn;
                              ippp++;
                              *ippp = ((strmno << 16) | strmseq);
                        }
                        stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_15;
                        sctp_abort_an_association(stcb->sctp_ep, stcb,
                            SCTP_PEER_FAULTY, oper, SCTP_SO_NOT_LOCKED);

                        *abort_flag = 1;
                        return (0);
                  } else {
                        if (sctp_does_tsn_belong_to_reasm(asoc, control->sinfo_tsn)) {
                              sctp_m_freem(control->data);
                              control->data = NULL;
                              if (control->whoFrom) {
                                    sctp_free_remote_addr(control->whoFrom);
                                    control->whoFrom = NULL;
                              }
                              sctp_free_a_readq(stcb, control);

                              oper = sctp_get_mbuf_for_msg((sizeof(struct sctp_paramhdr) + 3 * sizeof(uint32_t)),
                                  0, M_DONTWAIT, 1, MT_DATA);
                              if (oper) {
                                    struct sctp_paramhdr *ph;
                                    uint32_t *ippp;

                                    SCTP_BUF_LEN(oper) =
                                        sizeof(struct sctp_paramhdr) +
                                        (3 * sizeof(uint32_t));
                                    ph = mtod(oper,
                                        struct sctp_paramhdr *);
                                    ph->param_type =
                                        htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                    ph->param_length =
                                        htons(SCTP_BUF_LEN(oper));
                                    ippp = (uint32_t *) (ph + 1);
                                    *ippp = htonl(SCTP_FROM_SCTP_INDATA + SCTP_LOC_16);
                                    ippp++;
                                    *ippp = tsn;
                                    ippp++;
                                    *ippp = ((strmno << 16) | strmseq);
                              }
                              stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_16;
                              sctp_abort_an_association(stcb->sctp_ep,
                                  stcb, SCTP_PEER_FAULTY, oper, SCTP_SO_NOT_LOCKED);

                              *abort_flag = 1;
                              return (0);
                        }
                  }
            } else {
                  /* No PDAPI running */
                  if (!TAILQ_EMPTY(&asoc->reasmqueue)) {
                        /*
                         * Reassembly queue is NOT empty validate
                         * that this tsn does not need to be in
                         * reasembly queue. If it does then our peer
                         * is broken or evil.
                         */
                        if (sctp_does_tsn_belong_to_reasm(asoc, control->sinfo_tsn)) {
                              sctp_m_freem(control->data);
                              control->data = NULL;
                              if (control->whoFrom) {
                                    sctp_free_remote_addr(control->whoFrom);
                                    control->whoFrom = NULL;
                              }
                              sctp_free_a_readq(stcb, control);
                              oper = sctp_get_mbuf_for_msg((sizeof(struct sctp_paramhdr) + 3 * sizeof(uint32_t)),
                                  0, M_DONTWAIT, 1, MT_DATA);
                              if (oper) {
                                    struct sctp_paramhdr *ph;
                                    uint32_t *ippp;

                                    SCTP_BUF_LEN(oper) =
                                        sizeof(struct sctp_paramhdr) +
                                        (3 * sizeof(uint32_t));
                                    ph = mtod(oper,
                                        struct sctp_paramhdr *);
                                    ph->param_type =
                                        htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                                    ph->param_length =
                                        htons(SCTP_BUF_LEN(oper));
                                    ippp = (uint32_t *) (ph + 1);
                                    *ippp = htonl(SCTP_FROM_SCTP_INDATA + SCTP_LOC_17);
                                    ippp++;
                                    *ippp = tsn;
                                    ippp++;
                                    *ippp = ((strmno << 16) | strmseq);
                              }
                              stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_17;
                              sctp_abort_an_association(stcb->sctp_ep,
                                  stcb, SCTP_PEER_FAULTY, oper, SCTP_SO_NOT_LOCKED);

                              *abort_flag = 1;
                              return (0);
                        }
                  }
            }
            /* ok, if we reach here we have passed the sanity checks */
            if (chunk_flags & SCTP_DATA_UNORDERED) {
                  /* queue directly into socket buffer */
                  sctp_add_to_readq(stcb->sctp_ep, stcb,
                      control,
                      &stcb->sctp_socket->so_rcv, 1, SCTP_SO_NOT_LOCKED);
            } else {
                  /*
                   * Special check for when streams are resetting. We
                   * could be more smart about this and check the
                   * actual stream to see if it is not being reset..
                   * that way we would not create a HOLB when amongst
                   * streams being reset and those not being reset.
                   * 
                   * We take complete messages that have a stream reset
                   * intervening (aka the TSN is after where our
                   * cum-ack needs to be) off and put them on a
                   * pending_reply_queue. The reassembly ones we do
                   * not have to worry about since they are all sorted
                   * and proceessed by TSN order. It is only the
                   * singletons I must worry about.
                   */
                  if (((liste = TAILQ_FIRST(&asoc->resetHead)) != NULL) &&
                      ((compare_with_wrap(tsn, liste->tsn, MAX_TSN)))
                      ) {
                        /*
                         * yep its past where we need to reset... go
                         * ahead and queue it.
                         */
                        if (TAILQ_EMPTY(&asoc->pending_reply_queue)) {
                              /* first one on */
                              TAILQ_INSERT_TAIL(&asoc->pending_reply_queue, control, next);
                        } else {
                              struct sctp_queued_to_read *ctlOn;
                              unsigned char inserted = 0;

                              ctlOn = TAILQ_FIRST(&asoc->pending_reply_queue);
                              while (ctlOn) {
                                    if (compare_with_wrap(control->sinfo_tsn,
                                        ctlOn->sinfo_tsn, MAX_TSN)) {
                                          ctlOn = TAILQ_NEXT(ctlOn, next);
                                    } else {
                                          /* found it */
                                          TAILQ_INSERT_BEFORE(ctlOn, control, next);
                                          inserted = 1;
                                          break;
                                    }
                              }
                              if (inserted == 0) {
                                    /*
                                     * must be put at end, use
                                     * prevP (all setup from
                                     * loop) to setup nextP.
                                     */
                                    TAILQ_INSERT_TAIL(&asoc->pending_reply_queue, control, next);
                              }
                        }
                  } else {
                        sctp_queue_data_to_stream(stcb, asoc, control, abort_flag);
                        if (*abort_flag) {
                              return (0);
                        }
                  }
            }
      } else {
            /* Into the re-assembly queue */
            sctp_queue_data_for_reasm(stcb, asoc, chk, abort_flag);
            if (*abort_flag) {
                  /*
                   * the assoc is now gone and chk was put onto the
                   * reasm queue, which has all been freed.
                   */
                  *m = NULL;
                  return (0);
            }
      }
finish_express_del:
      if (compare_with_wrap(tsn, asoc->highest_tsn_inside_map, MAX_TSN)) {
            /* we have a new high score */
            asoc->highest_tsn_inside_map = tsn;
            if (sctp_logging_level & SCTP_MAP_LOGGING_ENABLE) {
                  sctp_log_map(0, 2, asoc->highest_tsn_inside_map, SCTP_MAP_SLIDE_RESULT);
            }
      }
      if (tsn == (asoc->cumulative_tsn + 1)) {
            /* Update cum-ack */
            asoc->cumulative_tsn = tsn;
      }
      if (last_chunk) {
            *m = NULL;
      }
      if (ordered) {
            SCTP_STAT_INCR_COUNTER64(sctps_inorderchunks);
      } else {
            SCTP_STAT_INCR_COUNTER64(sctps_inunorderchunks);
      }
      SCTP_STAT_INCR(sctps_recvdata);
      /* Set it present please */
      if (sctp_logging_level & SCTP_STR_LOGGING_ENABLE) {
            sctp_log_strm_del_alt(stcb, tsn, strmseq, strmno, SCTP_STR_LOG_FROM_MARK_TSN);
      }
      if (sctp_logging_level & SCTP_MAP_LOGGING_ENABLE) {
            sctp_log_map(asoc->mapping_array_base_tsn, asoc->cumulative_tsn,
                asoc->highest_tsn_inside_map, SCTP_MAP_PREPARE_SLIDE);
      }
      SCTP_TCB_LOCK_ASSERT(stcb);
      SCTP_SET_TSN_PRESENT(asoc->mapping_array, gap);
      /* check the special flag for stream resets */
      if (((liste = TAILQ_FIRST(&asoc->resetHead)) != NULL) &&
          ((compare_with_wrap(asoc->cumulative_tsn, liste->tsn, MAX_TSN)) ||
          (asoc->cumulative_tsn == liste->tsn))
          ) {
            /*
             * we have finished working through the backlogged TSN's now
             * time to reset streams. 1: call reset function. 2: free
             * pending_reply space 3: distribute any chunks in
             * pending_reply_queue.
             */
            struct sctp_queued_to_read *ctl;

            sctp_reset_in_stream(stcb, liste->number_entries, liste->req.list_of_streams);
            TAILQ_REMOVE(&asoc->resetHead, liste, next_resp);
            SCTP_FREE(liste, SCTP_M_STRESET);
            /* sa_ignore FREED_MEMORY */
            liste = TAILQ_FIRST(&asoc->resetHead);
            ctl = TAILQ_FIRST(&asoc->pending_reply_queue);
            if (ctl && (liste == NULL)) {
                  /* All can be removed */
                  while (ctl) {
                        TAILQ_REMOVE(&asoc->pending_reply_queue, ctl, next);
                        sctp_queue_data_to_stream(stcb, asoc, ctl, abort_flag);
                        if (*abort_flag) {
                              return (0);
                        }
                        ctl = TAILQ_FIRST(&asoc->pending_reply_queue);
                  }
            } else if (ctl) {
                  /* more than one in queue */
                  while (!compare_with_wrap(ctl->sinfo_tsn, liste->tsn, MAX_TSN)) {
                        /*
                         * if ctl->sinfo_tsn is <= liste->tsn we can
                         * process it which is the NOT of
                         * ctl->sinfo_tsn > liste->tsn
                         */
                        TAILQ_REMOVE(&asoc->pending_reply_queue, ctl, next);
                        sctp_queue_data_to_stream(stcb, asoc, ctl, abort_flag);
                        if (*abort_flag) {
                              return (0);
                        }
                        ctl = TAILQ_FIRST(&asoc->pending_reply_queue);
                  }
            }
            /*
             * Now service re-assembly to pick up anything that has been
             * held on reassembly queue?
             */
            sctp_deliver_reasm_check(stcb, asoc);
            need_reasm_check = 0;
      }
      if (need_reasm_check) {
            /* Another one waits ? */
            sctp_deliver_reasm_check(stcb, asoc);
      }
      return (1);
}

int8_t sctp_map_lookup_tab[256] = {
      -1, 0, -1, 1, -1, 0, -1, 2,
      -1, 0, -1, 1, -1, 0, -1, 3,
      -1, 0, -1, 1, -1, 0, -1, 2,
      -1, 0, -1, 1, -1, 0, -1, 4,
      -1, 0, -1, 1, -1, 0, -1, 2,
      -1, 0, -1, 1, -1, 0, -1, 3,
      -1, 0, -1, 1, -1, 0, -1, 2,
      -1, 0, -1, 1, -1, 0, -1, 5,
      -1, 0, -1, 1, -1, 0, -1, 2,
      -1, 0, -1, 1, -1, 0, -1, 3,
      -1, 0, -1, 1, -1, 0, -1, 2,
      -1, 0, -1, 1, -1, 0, -1, 4,
      -1, 0, -1, 1, -1, 0, -1, 2,
      -1, 0, -1, 1, -1, 0, -1, 3,
      -1, 0, -1, 1, -1, 0, -1, 2,
      -1, 0, -1, 1, -1, 0, -1, 6,
      -1, 0, -1, 1, -1, 0, -1, 2,
      -1, 0, -1, 1, -1, 0, -1, 3,
      -1, 0, -1, 1, -1, 0, -1, 2,
      -1, 0, -1, 1, -1, 0, -1, 4,
      -1, 0, -1, 1, -1, 0, -1, 2,
      -1, 0, -1, 1, -1, 0, -1, 3,
      -1, 0, -1, 1, -1, 0, -1, 2,
      -1, 0, -1, 1, -1, 0, -1, 5,
      -1, 0, -1, 1, -1, 0, -1, 2,
      -1, 0, -1, 1, -1, 0, -1, 3,
      -1, 0, -1, 1, -1, 0, -1, 2,
      -1, 0, -1, 1, -1, 0, -1, 4,
      -1, 0, -1, 1, -1, 0, -1, 2,
      -1, 0, -1, 1, -1, 0, -1, 3,
      -1, 0, -1, 1, -1, 0, -1, 2,
      -1, 0, -1, 1, -1, 0, -1, 7,
};


void
sctp_sack_check(struct sctp_tcb *stcb, int ok_to_sack, int was_a_gap, int *abort_flag)
{
      /*
       * Now we also need to check the mapping array in a couple of ways.
       * 1) Did we move the cum-ack point?
       */
      struct sctp_association *asoc;
      int i, at;
      int last_all_ones = 0;
      int slide_from, slide_end, lgap, distance;
      uint32_t old_cumack, old_base, old_highest;
      unsigned char aux_array[64];


      asoc = &stcb->asoc;
      at = 0;

      old_cumack = asoc->cumulative_tsn;
      old_base = asoc->mapping_array_base_tsn;
      old_highest = asoc->highest_tsn_inside_map;
      if (asoc->mapping_array_size < 64)
            memcpy(aux_array, asoc->mapping_array,
                asoc->mapping_array_size);
      else
            memcpy(aux_array, asoc->mapping_array, 64);

      /*
       * We could probably improve this a small bit by calculating the
       * offset of the current cum-ack as the starting point.
       */
      at = 0;
      for (i = 0; i < stcb->asoc.mapping_array_size; i++) {

            if (asoc->mapping_array[i] == 0xff) {
                  at += 8;
                  last_all_ones = 1;
            } else {
                  /* there is a 0 bit */
                  at += sctp_map_lookup_tab[asoc->mapping_array[i]];
                  last_all_ones = 0;
                  break;
            }
      }
      asoc->cumulative_tsn = asoc->mapping_array_base_tsn + (at - last_all_ones);
      /* at is one off, since in the table a embedded -1 is present */
      at++;

      if (compare_with_wrap(asoc->cumulative_tsn,
          asoc->highest_tsn_inside_map,
          MAX_TSN)) {
#ifdef INVARIANTS
            panic("huh, cumack 0x%x greater than high-tsn 0x%x in map",
                asoc->cumulative_tsn, asoc->highest_tsn_inside_map);
#else
            SCTP_PRINTF("huh, cumack 0x%x greater than high-tsn 0x%x in map - should panic?\n",
                asoc->cumulative_tsn, asoc->highest_tsn_inside_map);
            asoc->highest_tsn_inside_map = asoc->cumulative_tsn;
#endif
      }
      if ((asoc->cumulative_tsn == asoc->highest_tsn_inside_map) && (at >= 8)) {
            /* The complete array was completed by a single FR */
            /* higest becomes the cum-ack */
            int clr;

            asoc->cumulative_tsn = asoc->highest_tsn_inside_map;
            /* clear the array */
            clr = (at >> 3) + 1;
            if (clr > asoc->mapping_array_size) {
                  clr = asoc->mapping_array_size;
            }
            memset(asoc->mapping_array, 0, clr);
            /* base becomes one ahead of the cum-ack */
            asoc->mapping_array_base_tsn = asoc->cumulative_tsn + 1;
            if (sctp_logging_level & SCTP_MAP_LOGGING_ENABLE) {
                  sctp_log_map(old_base, old_cumack, old_highest,
                      SCTP_MAP_PREPARE_SLIDE);
                  sctp_log_map(asoc->mapping_array_base_tsn, asoc->cumulative_tsn,
                      asoc->highest_tsn_inside_map, SCTP_MAP_SLIDE_CLEARED);
            }
      } else if (at >= 8) {
            /* we can slide the mapping array down */
            /* Calculate the new byte postion we can move down */
            slide_from = at >> 3;
            /*
             * now calculate the ceiling of the move using our highest
             * TSN value
             */
            if (asoc->highest_tsn_inside_map >= asoc->mapping_array_base_tsn) {
                  lgap = asoc->highest_tsn_inside_map -
                      asoc->mapping_array_base_tsn;
            } else {
                  lgap = (MAX_TSN - asoc->mapping_array_base_tsn) +
                      asoc->highest_tsn_inside_map + 1;
            }
            slide_end = lgap >> 3;
            if (slide_end < slide_from) {
#ifdef INVARIANTS
                  panic("impossible slide");
#else
                  printf("impossible slide?\n");
                  return;
#endif
            }
            distance = (slide_end - slide_from) + 1;
            if (sctp_logging_level & SCTP_MAP_LOGGING_ENABLE) {
                  sctp_log_map(old_base, old_cumack, old_highest,
                      SCTP_MAP_PREPARE_SLIDE);
                  sctp_log_map((uint32_t) slide_from, (uint32_t) slide_end,
                      (uint32_t) lgap, SCTP_MAP_SLIDE_FROM);
            }
            if (distance + slide_from > asoc->mapping_array_size ||
                distance < 0) {
                  /*
                   * Here we do NOT slide forward the array so that
                   * hopefully when more data comes in to fill it up
                   * we will be able to slide it forward. Really I
                   * don't think this should happen :-0
                   */

                  if (sctp_logging_level & SCTP_MAP_LOGGING_ENABLE) {
                        sctp_log_map((uint32_t) distance, (uint32_t) slide_from,
                            (uint32_t) asoc->mapping_array_size,
                            SCTP_MAP_SLIDE_NONE);
                  }
            } else {
                  int ii;

                  for (ii = 0; ii < distance; ii++) {
                        asoc->mapping_array[ii] =
                            asoc->mapping_array[slide_from + ii];
                  }
                  for (ii = distance; ii <= slide_end; ii++) {
                        asoc->mapping_array[ii] = 0;
                  }
                  asoc->mapping_array_base_tsn += (slide_from << 3);
                  if (sctp_logging_level & SCTP_MAP_LOGGING_ENABLE) {
                        sctp_log_map(asoc->mapping_array_base_tsn,
                            asoc->cumulative_tsn, asoc->highest_tsn_inside_map,
                            SCTP_MAP_SLIDE_RESULT);
                  }
            }
      }
      /*
       * Now we need to see if we need to queue a sack or just start the
       * timer (if allowed).
       */
      if (ok_to_sack) {
            if (SCTP_GET_STATE(asoc) == SCTP_STATE_SHUTDOWN_SENT) {
                  /*
                   * Ok special case, in SHUTDOWN-SENT case. here we
                   * maker sure SACK timer is off and instead send a
                   * SHUTDOWN and a SACK
                   */
                  if (SCTP_OS_TIMER_PENDING(&stcb->asoc.dack_timer.timer)) {
                        sctp_timer_stop(SCTP_TIMER_TYPE_RECV,
                            stcb->sctp_ep, stcb, NULL, SCTP_FROM_SCTP_INDATA + SCTP_LOC_18);
                  }
                  sctp_send_shutdown(stcb, stcb->asoc.primary_destination);
                  sctp_send_sack(stcb);
            } else {
                  int is_a_gap;

                  /* is there a gap now ? */
                  is_a_gap = compare_with_wrap(stcb->asoc.highest_tsn_inside_map,
                      stcb->asoc.cumulative_tsn, MAX_TSN);

                  /*
                   * CMT DAC algorithm: increase number of packets
                   * received since last ack
                   */
                  stcb->asoc.cmt_dac_pkts_rcvd++;

                  if ((stcb->asoc.send_sack == 1) ||  /* We need to send a
                                                 * SACK */
                      ((was_a_gap) && (is_a_gap == 0)) ||   /* was a gap, but no
                                                 * longer is one */
                      (stcb->asoc.numduptsns) ||      /* we have dup's */
                      (is_a_gap) || /* is still a gap */
                      (stcb->asoc.delayed_ack == 0) ||      /* Delayed sack disabled */
                      (stcb->asoc.data_pkts_seen >= stcb->asoc.sack_freq)     /* hit limit of pkts */
                      ) {

                        if ((sctp_cmt_on_off) && (sctp_cmt_use_dac) &&
                            (stcb->asoc.send_sack == 0) &&
                            (stcb->asoc.numduptsns == 0) &&
                            (stcb->asoc.delayed_ack) &&
                            (!SCTP_OS_TIMER_PENDING(&stcb->asoc.dack_timer.timer))) {

                              /*
                               * CMT DAC algorithm: With CMT,
                               * delay acks even in the face of
                               * 
                               * reordering. Therefore, if acks that
                               * do not have to be sent because of
                               * the above reasons, will be
                               * delayed. That is, acks that would
                               * have been sent due to gap reports
                               * will be delayed with DAC. Start
                               * the delayed ack timer.
                               */
                              sctp_timer_start(SCTP_TIMER_TYPE_RECV,
                                  stcb->sctp_ep, stcb, NULL);
                        } else {
                              /*
                               * Ok we must build a SACK since the
                               * timer is pending, we got our
                               * first packet OR there are gaps or
                               * duplicates.
                               */
                              (void)SCTP_OS_TIMER_STOP(&stcb->asoc.dack_timer.timer);
                              sctp_send_sack(stcb);
                        }
                  } else {
                        if (!SCTP_OS_TIMER_PENDING(&stcb->asoc.dack_timer.timer)) {
                              sctp_timer_start(SCTP_TIMER_TYPE_RECV,
                                  stcb->sctp_ep, stcb, NULL);
                        }
                  }
            }
      }
}

void
sctp_service_queues(struct sctp_tcb *stcb, struct sctp_association *asoc)
{
      struct sctp_tmit_chunk *chk;
      uint32_t tsize;
      uint16_t nxt_todel;

      if (asoc->fragmented_delivery_inprogress) {
            sctp_service_reassembly(stcb, asoc);
      }
      /* Can we proceed further, i.e. the PD-API is complete */
      if (asoc->fragmented_delivery_inprogress) {
            /* no */
            return;
      }
      /*
       * Now is there some other chunk I can deliver from the reassembly
       * queue.
       */
doit_again:
      chk = TAILQ_FIRST(&asoc->reasmqueue);
      if (chk == NULL) {
            asoc->size_on_reasm_queue = 0;
            asoc->cnt_on_reasm_queue = 0;
            return;
      }
      nxt_todel = asoc->strmin[chk->rec.data.stream_number].last_sequence_delivered + 1;
      if ((chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG) &&
          ((nxt_todel == chk->rec.data.stream_seq) ||
          (chk->rec.data.rcv_flags & SCTP_DATA_UNORDERED))) {
            /*
             * Yep the first one is here. We setup to start reception,
             * by backing down the TSN just in case we can't deliver.
             */

            /*
             * Before we start though either all of the message should
             * be here or 1/4 the socket buffer max or nothing on the
             * delivery queue and something can be delivered.
             */
            if ((sctp_is_all_msg_on_reasm(asoc, &tsize) ||
                (tsize >= stcb->sctp_ep->partial_delivery_point))) {
                  asoc->fragmented_delivery_inprogress = 1;
                  asoc->tsn_last_delivered = chk->rec.data.TSN_seq - 1;
                  asoc->str_of_pdapi = chk->rec.data.stream_number;
                  asoc->ssn_of_pdapi = chk->rec.data.stream_seq;
                  asoc->pdapi_ppid = chk->rec.data.payloadtype;
                  asoc->fragment_flags = chk->rec.data.rcv_flags;
                  sctp_service_reassembly(stcb, asoc);
                  if (asoc->fragmented_delivery_inprogress == 0) {
                        goto doit_again;
                  }
            }
      }
}

int
sctp_process_data(struct mbuf **mm, int iphlen, int *offset, int length,
    struct sctphdr *sh, struct sctp_inpcb *inp, struct sctp_tcb *stcb,
    struct sctp_nets *net, uint32_t * high_tsn)
{
      struct sctp_data_chunk *ch, chunk_buf;
      struct sctp_association *asoc;
      int num_chunks = 0;     /* number of control chunks processed */
      int stop_proc = 0;
      int chk_length, break_flag, last_chunk;
      int abort_flag = 0, was_a_gap = 0;
      struct mbuf *m;

      /* set the rwnd */
      sctp_set_rwnd(stcb, &stcb->asoc);

      m = *mm;
      SCTP_TCB_LOCK_ASSERT(stcb);
      asoc = &stcb->asoc;
      if (compare_with_wrap(stcb->asoc.highest_tsn_inside_map,
          stcb->asoc.cumulative_tsn, MAX_TSN)) {
            /* there was a gap before this data was processed */
            was_a_gap = 1;
      }
      /*
       * setup where we got the last DATA packet from for any SACK that
       * may need to go out. Don't bump the net. This is done ONLY when a
       * chunk is assigned.
       */
      asoc->last_data_chunk_from = net;

      /*-
       * Now before we proceed we must figure out if this is a wasted
       * cluster... i.e. it is a small packet sent in and yet the driver
       * underneath allocated a full cluster for it. If so we must copy it
       * to a smaller mbuf and free up the cluster mbuf. This will help
       * with cluster starvation. Note for __Panda__ we don't do this
       * since it has clusters all the way down to 64 bytes.
       */
      if (SCTP_BUF_LEN(m) < (long)MLEN && SCTP_BUF_NEXT(m) == NULL) {
            /* we only handle mbufs that are singletons.. not chains */
            m = sctp_get_mbuf_for_msg(SCTP_BUF_LEN(m), 0, M_DONTWAIT, 1, MT_DATA);
            if (m) {
                  /* ok lets see if we can copy the data up */
                  caddr_t *from, *to;

                  /* get the pointers and copy */
                  to = mtod(m, caddr_t *);
                  from = mtod((*mm), caddr_t *);
                  memcpy(to, from, SCTP_BUF_LEN((*mm)));
                  /* copy the length and free up the old */
                  SCTP_BUF_LEN(m) = SCTP_BUF_LEN((*mm));
                  sctp_m_freem(*mm);
                  /* sucess, back copy */
                  *mm = m;
            } else {
                  /* We are in trouble in the mbuf world .. yikes */
                  m = *mm;
            }
      }
      /* get pointer to the first chunk header */
      ch = (struct sctp_data_chunk *)sctp_m_getptr(m, *offset,
          sizeof(struct sctp_data_chunk), (uint8_t *) & chunk_buf);
      if (ch == NULL) {
            return (1);
      }
      /*
       * process all DATA chunks...
       */
      *high_tsn = asoc->cumulative_tsn;
      break_flag = 0;
      asoc->data_pkts_seen++;
      while (stop_proc == 0) {
            /* validate chunk length */
            chk_length = ntohs(ch->ch.chunk_length);
            if (length - *offset < chk_length) {
                  /* all done, mutulated chunk */
                  stop_proc = 1;
                  break;
            }
            if (ch->ch.chunk_type == SCTP_DATA) {
                  if ((size_t)chk_length < sizeof(struct sctp_data_chunk) + 1) {
                        /*
                         * Need to send an abort since we had a
                         * invalid data chunk.
                         */
                        struct mbuf *op_err;

                        op_err = sctp_get_mbuf_for_msg((sizeof(struct sctp_paramhdr) + 2 * sizeof(uint32_t)),
                            0, M_DONTWAIT, 1, MT_DATA);

                        if (op_err) {
                              struct sctp_paramhdr *ph;
                              uint32_t *ippp;

                              SCTP_BUF_LEN(op_err) = sizeof(struct sctp_paramhdr) +
                                  (2 * sizeof(uint32_t));
                              ph = mtod(op_err, struct sctp_paramhdr *);
                              ph->param_type =
                                  htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                              ph->param_length = htons(SCTP_BUF_LEN(op_err));
                              ippp = (uint32_t *) (ph + 1);
                              *ippp = htonl(SCTP_FROM_SCTP_INDATA + SCTP_LOC_19);
                              ippp++;
                              *ippp = asoc->cumulative_tsn;

                        }
                        stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_19;
                        sctp_abort_association(inp, stcb, m, iphlen, sh,
                            op_err, 0);
                        return (2);
                  }
#ifdef SCTP_AUDITING_ENABLED
                  sctp_audit_log(0xB1, 0);
#endif
                  if (SCTP_SIZE32(chk_length) == (length - *offset)) {
                        last_chunk = 1;
                  } else {
                        last_chunk = 0;
                  }
                  if (sctp_process_a_data_chunk(stcb, asoc, mm, *offset, ch,
                      chk_length, net, high_tsn, &abort_flag, &break_flag,
                      last_chunk)) {
                        num_chunks++;
                  }
                  if (abort_flag)
                        return (2);

                  if (break_flag) {
                        /*
                         * Set because of out of rwnd space and no
                         * drop rep space left.
                         */
                        stop_proc = 1;
                        break;
                  }
            } else {
                  /* not a data chunk in the data region */
                  switch (ch->ch.chunk_type) {
                  case SCTP_INITIATION:
                  case SCTP_INITIATION_ACK:
                  case SCTP_SELECTIVE_ACK:
                  case SCTP_HEARTBEAT_REQUEST:
                  case SCTP_HEARTBEAT_ACK:
                  case SCTP_ABORT_ASSOCIATION:
                  case SCTP_SHUTDOWN:
                  case SCTP_SHUTDOWN_ACK:
                  case SCTP_OPERATION_ERROR:
                  case SCTP_COOKIE_ECHO:
                  case SCTP_COOKIE_ACK:
                  case SCTP_ECN_ECHO:
                  case SCTP_ECN_CWR:
                  case SCTP_SHUTDOWN_COMPLETE:
                  case SCTP_AUTHENTICATION:
                  case SCTP_ASCONF_ACK:
                  case SCTP_PACKET_DROPPED:
                  case SCTP_STREAM_RESET:
                  case SCTP_FORWARD_CUM_TSN:
                  case SCTP_ASCONF:
                        /*
                         * Now, what do we do with KNOWN chunks that
                         * are NOT in the right place?
                         * 
                         * For now, I do nothing but ignore them. We
                         * may later want to add sysctl stuff to
                         * switch out and do either an ABORT() or
                         * possibly process them.
                         */
                        if (sctp_strict_data_order) {
                              struct mbuf *op_err;

                              op_err = sctp_generate_invmanparam(SCTP_CAUSE_PROTOCOL_VIOLATION);
                              sctp_abort_association(inp, stcb, m, iphlen, sh, op_err, 0);
                              return (2);
                        }
                        break;
                  default:
                        /* unknown chunk type, use bit rules */
                        if (ch->ch.chunk_type & 0x40) {
                              /* Add a error report to the queue */
                              struct mbuf *merr;
                              struct sctp_paramhdr *phd;

                              merr = sctp_get_mbuf_for_msg(sizeof(*phd), 0, M_DONTWAIT, 1, MT_DATA);
                              if (merr) {
                                    phd = mtod(merr, struct sctp_paramhdr *);
                                    /*
                                     * We cheat and use param
                                     * type since we did not
                                     * bother to define a error
                                     * cause struct. They are
                                     * the same basic format
                                     * with different names.
                                     */
                                    phd->param_type =
                                        htons(SCTP_CAUSE_UNRECOG_CHUNK);
                                    phd->param_length =
                                        htons(chk_length + sizeof(*phd));
                                    SCTP_BUF_LEN(merr) = sizeof(*phd);
                                    SCTP_BUF_NEXT(merr) = SCTP_M_COPYM(m, *offset,
                                        SCTP_SIZE32(chk_length),
                                        M_DONTWAIT);
                                    if (SCTP_BUF_NEXT(merr)) {
                                          sctp_queue_op_err(stcb, merr);
                                    } else {
                                          sctp_m_freem(merr);
                                    }
                              }
                        }
                        if ((ch->ch.chunk_type & 0x80) == 0) {
                              /* discard the rest of this packet */
                              stop_proc = 1;
                        }     /* else skip this bad chunk and
                               * continue... */
                        break;
                  };    /* switch of chunk type */
            }
            *offset += SCTP_SIZE32(chk_length);
            if ((*offset >= length) || stop_proc) {
                  /* no more data left in the mbuf chain */
                  stop_proc = 1;
                  continue;
            }
            ch = (struct sctp_data_chunk *)sctp_m_getptr(m, *offset,
                sizeof(struct sctp_data_chunk), (uint8_t *) & chunk_buf);
            if (ch == NULL) {
                  *offset = length;
                  stop_proc = 1;
                  break;

            }
      }                 /* while */
      if (break_flag) {
            /*
             * we need to report rwnd overrun drops.
             */
            sctp_send_packet_dropped(stcb, net, *mm, iphlen, 0);
      }
      if (num_chunks) {
            /*
             * Did we get data, if so update the time for auto-close and
             * give peer credit for being alive.
             */
            SCTP_STAT_INCR(sctps_recvpktwithdata);
            if (sctp_logging_level & SCTP_THRESHOLD_LOGGING) {
                  sctp_misc_ints(SCTP_THRESHOLD_CLEAR,
                      stcb->asoc.overall_error_count,
                      0,
                      SCTP_FROM_SCTP_INDATA,
                      __LINE__);
            }
            stcb->asoc.overall_error_count = 0;
            (void)SCTP_GETTIME_TIMEVAL(&stcb->asoc.time_last_rcvd);
      }
      /* now service all of the reassm queue if needed */
      if (!(TAILQ_EMPTY(&asoc->reasmqueue)))
            sctp_service_queues(stcb, asoc);

      if (SCTP_GET_STATE(asoc) == SCTP_STATE_SHUTDOWN_SENT) {
            /* Assure that we ack right away */
            stcb->asoc.send_sack = 1;
      }
      /* Start a sack timer or QUEUE a SACK for sending */
      if ((stcb->asoc.cumulative_tsn == stcb->asoc.highest_tsn_inside_map) &&
          (stcb->asoc.mapping_array[0] != 0xff)) {
            if ((stcb->asoc.data_pkts_seen >= stcb->asoc.sack_freq) ||
                (stcb->asoc.delayed_ack == 0) ||
                (stcb->asoc.numduptsns) ||
                (stcb->asoc.send_sack == 1)) {
                  if (SCTP_OS_TIMER_PENDING(&stcb->asoc.dack_timer.timer)) {
                        (void)SCTP_OS_TIMER_STOP(&stcb->asoc.dack_timer.timer);
                  }
                  sctp_send_sack(stcb);
            } else {
                  if (!SCTP_OS_TIMER_PENDING(&stcb->asoc.dack_timer.timer)) {
                        sctp_timer_start(SCTP_TIMER_TYPE_RECV,
                            stcb->sctp_ep, stcb, NULL);
                  }
            }
      } else {
            sctp_sack_check(stcb, 1, was_a_gap, &abort_flag);
      }
      if (abort_flag)
            return (2);

      return (0);
}

static void
sctp_handle_segments(struct mbuf *m, int *offset, struct sctp_tcb *stcb, struct sctp_association *asoc,
    struct sctp_sack_chunk *ch, uint32_t last_tsn, uint32_t * biggest_tsn_acked,
    uint32_t * biggest_newly_acked_tsn, uint32_t * this_sack_lowest_newack,
    int num_seg, int *ecn_seg_sums)
{
      /************************************************/
      /* process fragments and update sendqueue        */
      /************************************************/
      struct sctp_sack *sack;
      struct sctp_gap_ack_block *frag, block;
      struct sctp_tmit_chunk *tp1;
      int i;
      unsigned int j;
      int num_frs = 0;

      uint16_t frag_strt, frag_end, primary_flag_set;
      u_long last_frag_high;

      /*
       * @@@ JRI : TODO: This flag is not used anywhere .. remove?
       */
      if (asoc->primary_destination->dest_state & SCTP_ADDR_SWITCH_PRIMARY) {
            primary_flag_set = 1;
      } else {
            primary_flag_set = 0;
      }
      sack = &ch->sack;

      frag = (struct sctp_gap_ack_block *)sctp_m_getptr(m, *offset,
          sizeof(struct sctp_gap_ack_block), (uint8_t *) & block);
      *offset += sizeof(block);
      if (frag == NULL) {
            return;
      }
      tp1 = NULL;
      last_frag_high = 0;
      for (i = 0; i < num_seg; i++) {
            frag_strt = ntohs(frag->start);
            frag_end = ntohs(frag->end);
            /* some sanity checks on the fargment offsets */
            if (frag_strt > frag_end) {
                  /* this one is malformed, skip */
                  frag++;
                  continue;
            }
            if (compare_with_wrap((frag_end + last_tsn), *biggest_tsn_acked,
                MAX_TSN))
                  *biggest_tsn_acked = frag_end + last_tsn;

            /* mark acked dgs and find out the highestTSN being acked */
            if (tp1 == NULL) {
                  tp1 = TAILQ_FIRST(&asoc->sent_queue);

                  /* save the locations of the last frags */
                  last_frag_high = frag_end + last_tsn;
            } else {
                  /*
                   * now lets see if we need to reset the queue due to
                   * a out-of-order SACK fragment
                   */
                  if (compare_with_wrap(frag_strt + last_tsn,
                      last_frag_high, MAX_TSN)) {
                        /*
                         * if the new frag starts after the last TSN
                         * frag covered, we are ok and this one is
                         * beyond the last one
                         */
                        ;
                  } else {
                        /*
                         * ok, they have reset us, so we need to
                         * reset the queue this will cause extra
                         * hunting but hey, they chose the
                         * performance hit when they failed to order
                         * there gaps..
                         */
                        tp1 = TAILQ_FIRST(&asoc->sent_queue);
                  }
                  last_frag_high = frag_end + last_tsn;
            }
            for (j = frag_strt + last_tsn; (compare_with_wrap((frag_end + last_tsn), j, MAX_TSN)); j++) {
                  while (tp1) {
                        if (tp1->rec.data.doing_fast_retransmit)
                              num_frs++;

                        /*
                         * CMT: CUCv2 algorithm. For each TSN being
                         * processed from the sent queue, track the
                         * next expected pseudo-cumack, or
                         * rtx_pseudo_cumack, if required. Separate
                         * cumack trackers for first transmissions,
                         * and retransmissions.
                         */
                        if ((tp1->whoTo->find_pseudo_cumack == 1) && (tp1->sent < SCTP_DATAGRAM_RESEND) &&
                            (tp1->snd_count == 1)) {
                              tp1->whoTo->pseudo_cumack = tp1->rec.data.TSN_seq;
                              tp1->whoTo->find_pseudo_cumack = 0;
                        }
                        if ((tp1->whoTo->find_rtx_pseudo_cumack == 1) && (tp1->sent < SCTP_DATAGRAM_RESEND) &&
                            (tp1->snd_count > 1)) {
                              tp1->whoTo->rtx_pseudo_cumack = tp1->rec.data.TSN_seq;
                              tp1->whoTo->find_rtx_pseudo_cumack = 0;
                        }
                        if (tp1->rec.data.TSN_seq == j) {
                              if (tp1->sent != SCTP_DATAGRAM_UNSENT) {
                                    /*
                                     * must be held until
                                     * cum-ack passes
                                     */
                                    /*
                                     * ECN Nonce: Add the nonce
                                     * value to the sender's
                                     * nonce sum
                                     */
                                    if (tp1->sent < SCTP_DATAGRAM_RESEND) {
                                          /*-
                                           * If it is less than RESEND, it is
                                           * now no-longer in flight.
                                           * Higher values may already be set
                                           * via previous Gap Ack Blocks...
                                           * i.e. ACKED or RESEND.
                                           */
                                          if (compare_with_wrap(tp1->rec.data.TSN_seq,
                                              *biggest_newly_acked_tsn, MAX_TSN)) {
                                                *biggest_newly_acked_tsn = tp1->rec.data.TSN_seq;
                                          }
                                          /*
                                           * CMT: SFR algo
                                           * (and HTNA) - set
                                           * saw_newack to 1
                                           * for dest being
                                           * newly acked.
                                           * update
                                           * this_sack_highest_
                                           * newack if
                                           * appropriate.
                                           */
                                          if (tp1->rec.data.chunk_was_revoked == 0)
                                                tp1->whoTo->saw_newack = 1;

                                          if (compare_with_wrap(tp1->rec.data.TSN_seq,
                                              tp1->whoTo->this_sack_highest_newack,
                                              MAX_TSN)) {
                                                tp1->whoTo->this_sack_highest_newack =
                                                    tp1->rec.data.TSN_seq;
                                          }
                                          /*
                                           * CMT DAC algo:
                                           * also update
                                           * this_sack_lowest_n
                                           * ewack
                                           */
                                          if (*this_sack_lowest_newack == 0) {
                                                if (sctp_logging_level & SCTP_SACK_LOGGING_ENABLE) {
                                                      sctp_log_sack(*this_sack_lowest_newack,
                                                          last_tsn,
                                                          tp1->rec.data.TSN_seq,
                                                          0,
                                                          0,
                                                          SCTP_LOG_TSN_ACKED);
                                                }
                                                *this_sack_lowest_newack = tp1->rec.data.TSN_seq;
                                          }
                                          /*
                                           * CMT: CUCv2
                                           * algorithm. If
                                           * (rtx-)pseudo-cumac
                                           * k for corresp
                                           * dest is being
                                           * acked, then we
                                           * have a new
                                           * (rtx-)pseudo-cumac
                                           * k. Set
                                           * new_(rtx_)pseudo_c
                                           * umack to TRUE so
                                           * that the cwnd for
                                           * this dest can be
                                           * updated. Also
                                           * trigger search
                                           * for the next
                                           * expected
                                           * (rtx-)pseudo-cumac
                                           * k. Separate
                                           * pseudo_cumack
                                           * trackers for
                                           * first
                                           * transmissions and
                                           * retransmissions.
                                           */
                                          if (tp1->rec.data.TSN_seq == tp1->whoTo->pseudo_cumack) {
                                                if (tp1->rec.data.chunk_was_revoked == 0) {
                                                      tp1->whoTo->new_pseudo_cumack = 1;
                                                }
                                                tp1->whoTo->find_pseudo_cumack = 1;
                                          }
                                          if (sctp_logging_level & SCTP_CWND_LOGGING_ENABLE) {
                                                sctp_log_cwnd(stcb, tp1->whoTo, tp1->rec.data.TSN_seq, SCTP_CWND_LOG_FROM_SACK);
                                          }
                                          if (tp1->rec.data.TSN_seq == tp1->whoTo->rtx_pseudo_cumack) {
                                                if (tp1->rec.data.chunk_was_revoked == 0) {
                                                      tp1->whoTo->new_pseudo_cumack = 1;
                                                }
                                                tp1->whoTo->find_rtx_pseudo_cumack = 1;
                                          }
                                          if (sctp_logging_level & SCTP_SACK_LOGGING_ENABLE) {
                                                sctp_log_sack(*biggest_newly_acked_tsn,
                                                    last_tsn,
                                                    tp1->rec.data.TSN_seq,
                                                    frag_strt,
                                                    frag_end,
                                                    SCTP_LOG_TSN_ACKED);
                                          }
                                          if (sctp_logging_level & SCTP_FLIGHT_LOGGING_ENABLE) {
                                                sctp_misc_ints(SCTP_FLIGHT_LOG_DOWN_GAP,
                                                    tp1->whoTo->flight_size,
                                                    tp1->book_size,
                                                    (uintptr_t) tp1->whoTo,
                                                    tp1->rec.data.TSN_seq);
                                          }
                                          sctp_flight_size_decrease(tp1);
                                          sctp_total_flight_decrease(stcb, tp1);

                                          tp1->whoTo->net_ack += tp1->send_size;
                                          if (tp1->snd_count < 2) {
                                                /*
                                                 * True
                                                 * non-retran
                                                 * smited
                                                 * chunk */
                                                tp1->whoTo->net_ack2 += tp1->send_size;

                                                /*
                                                 * update RTO
                                                 * too ? */
                                                if (tp1->do_rtt) {
                                                      tp1->whoTo->RTO =
                                                          sctp_calculate_rto(stcb,
                                                          asoc,
                                                          tp1->whoTo,
                                                          &tp1->sent_rcv_time,
                                                          sctp_align_safe_nocopy);
                                                      tp1->do_rtt = 0;
                                                }
                                          }
                                    }
                                    if (tp1->sent <= SCTP_DATAGRAM_RESEND) {
                                          (*ecn_seg_sums) += tp1->rec.data.ect_nonce;
                                          (*ecn_seg_sums) &= SCTP_SACK_NONCE_SUM;
                                          if (compare_with_wrap(tp1->rec.data.TSN_seq,
                                              asoc->this_sack_highest_gap,
                                              MAX_TSN)) {
                                                asoc->this_sack_highest_gap =
                                                    tp1->rec.data.TSN_seq;
                                          }
                                          if (tp1->sent == SCTP_DATAGRAM_RESEND) {
                                                sctp_ucount_decr(asoc->sent_queue_retran_cnt);
#ifdef SCTP_AUDITING_ENABLED
                                                sctp_audit_log(0xB2,
                                                    (asoc->sent_queue_retran_cnt & 0x000000ff));
#endif
                                          }
                                    }
                                    /*
                                     * All chunks NOT UNSENT
                                     * fall through here and are
                                     * marked
                                     */
                                    tp1->sent = SCTP_DATAGRAM_MARKED;
                                    if (tp1->rec.data.chunk_was_revoked) {
                                          /* deflate the cwnd */
                                          tp1->whoTo->cwnd -= tp1->book_size;
                                          tp1->rec.data.chunk_was_revoked = 0;
                                    }
                              }
                              break;
                        }     /* if (tp1->TSN_seq == j) */
                        if (compare_with_wrap(tp1->rec.data.TSN_seq, j,
                            MAX_TSN))
                              break;

                        tp1 = TAILQ_NEXT(tp1, sctp_next);
                  }     /* end while (tp1) */
            }           /* end for (j = fragStart */
            frag = (struct sctp_gap_ack_block *)sctp_m_getptr(m, *offset,
                sizeof(struct sctp_gap_ack_block), (uint8_t *) & block);
            *offset += sizeof(block);
            if (frag == NULL) {
                  break;
            }
      }
      if (sctp_logging_level & SCTP_FR_LOGGING_ENABLE) {
            if (num_frs)
                  sctp_log_fr(*biggest_tsn_acked,
                      *biggest_newly_acked_tsn,
                      last_tsn, SCTP_FR_LOG_BIGGEST_TSNS);
      }
}

static void
sctp_check_for_revoked(struct sctp_tcb *stcb,
    struct sctp_association *asoc, uint32_t cumack,
    u_long biggest_tsn_acked)
{
      struct sctp_tmit_chunk *tp1;
      int tot_revoked = 0;

      tp1 = TAILQ_FIRST(&asoc->sent_queue);
      while (tp1) {
            if (compare_with_wrap(tp1->rec.data.TSN_seq, cumack,
                MAX_TSN)) {
                  /*
                   * ok this guy is either ACK or MARKED. If it is
                   * ACKED it has been previously acked but not this
                   * time i.e. revoked.  If it is MARKED it was ACK'ed
                   * again.
                   */
                  if (compare_with_wrap(tp1->rec.data.TSN_seq, biggest_tsn_acked,
                      MAX_TSN))
                        break;


                  if (tp1->sent == SCTP_DATAGRAM_ACKED) {
                        /* it has been revoked */
                        tp1->sent = SCTP_DATAGRAM_SENT;
                        tp1->rec.data.chunk_was_revoked = 1;
                        /*
                         * We must add this stuff back in to assure
                         * timers and such get started.
                         */
                        if (sctp_logging_level & SCTP_FLIGHT_LOGGING_ENABLE) {
                              sctp_misc_ints(SCTP_FLIGHT_LOG_UP_REVOKE,
                                  tp1->whoTo->flight_size,
                                  tp1->book_size,
                                  (uintptr_t) tp1->whoTo,
                                  tp1->rec.data.TSN_seq);
                        }
                        sctp_flight_size_increase(tp1);
                        sctp_total_flight_increase(stcb, tp1);
                        /*
                         * We inflate the cwnd to compensate for our
                         * artificial inflation of the flight_size.
                         */
                        tp1->whoTo->cwnd += tp1->book_size;
                        tot_revoked++;
                        if (sctp_logging_level & SCTP_SACK_LOGGING_ENABLE) {
                              sctp_log_sack(asoc->last_acked_seq,
                                  cumack,
                                  tp1->rec.data.TSN_seq,
                                  0,
                                  0,
                                  SCTP_LOG_TSN_REVOKED);
                        }
                  } else if (tp1->sent == SCTP_DATAGRAM_MARKED) {
                        /* it has been re-acked in this SACK */
                        tp1->sent = SCTP_DATAGRAM_ACKED;
                  }
            }
            if (tp1->sent == SCTP_DATAGRAM_UNSENT)
                  break;
            tp1 = TAILQ_NEXT(tp1, sctp_next);
      }
      if (tot_revoked > 0) {
            /*
             * Setup the ecn nonce re-sync point. We do this since once
             * data is revoked we begin to retransmit things, which do
             * NOT have the ECN bits set. This means we are now out of
             * sync and must wait until we get back in sync with the
             * peer to check ECN bits.
             */
            tp1 = TAILQ_FIRST(&asoc->send_queue);
            if (tp1 == NULL) {
                  asoc->nonce_resync_tsn = asoc->sending_seq;
            } else {
                  asoc->nonce_resync_tsn = tp1->rec.data.TSN_seq;
            }
            asoc->nonce_wait_for_ecne = 0;
            asoc->nonce_sum_check = 0;
      }
}

static void
sctp_strike_gap_ack_chunks(struct sctp_tcb *stcb, struct sctp_association *asoc,
    u_long biggest_tsn_acked, u_long biggest_tsn_newly_acked, u_long this_sack_lowest_newack, int accum_moved)
{
      struct sctp_tmit_chunk *tp1;
      int strike_flag = 0;
      struct timeval now;
      int tot_retrans = 0;
      uint32_t sending_seq;
      struct sctp_nets *net;
      int num_dests_sacked = 0;

      /*
       * select the sending_seq, this is either the next thing ready to be
       * sent but not transmitted, OR, the next seq we assign.
       */
      tp1 = TAILQ_FIRST(&stcb->asoc.send_queue);
      if (tp1 == NULL) {
            sending_seq = asoc->sending_seq;
      } else {
            sending_seq = tp1->rec.data.TSN_seq;
      }

      /* CMT DAC algo: finding out if SACK is a mixed SACK */
      if (sctp_cmt_on_off && sctp_cmt_use_dac) {
            TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                  if (net->saw_newack)
                        num_dests_sacked++;
            }
      }
      if (stcb->asoc.peer_supports_prsctp) {
            (void)SCTP_GETTIME_TIMEVAL(&now);
      }
      tp1 = TAILQ_FIRST(&asoc->sent_queue);
      while (tp1) {
            strike_flag = 0;
            if (tp1->no_fr_allowed) {
                  /* this one had a timeout or something */
                  tp1 = TAILQ_NEXT(tp1, sctp_next);
                  continue;
            }
            if (sctp_logging_level & SCTP_FR_LOGGING_ENABLE) {
                  if (tp1->sent < SCTP_DATAGRAM_RESEND)
                        sctp_log_fr(biggest_tsn_newly_acked,
                            tp1->rec.data.TSN_seq,
                            tp1->sent,
                            SCTP_FR_LOG_CHECK_STRIKE);
            }
            if (compare_with_wrap(tp1->rec.data.TSN_seq, biggest_tsn_acked,
                MAX_TSN) ||
                tp1->sent == SCTP_DATAGRAM_UNSENT) {
                  /* done */
                  break;
            }
            if (stcb->asoc.peer_supports_prsctp) {
                  if ((PR_SCTP_TTL_ENABLED(tp1->flags)) && tp1->sent < SCTP_DATAGRAM_ACKED) {
                        /* Is it expired? */
                        if (
                            (timevalcmp(&now, &tp1->rec.data.timetodrop, >))
                            ) {
                              /* Yes so drop it */
                              if (tp1->data != NULL) {
                                    (void)sctp_release_pr_sctp_chunk(stcb, tp1,
                                        (SCTP_RESPONSE_TO_USER_REQ | SCTP_NOTIFY_DATAGRAM_SENT),
                                        &asoc->sent_queue, SCTP_SO_NOT_LOCKED);
                              }
                              tp1 = TAILQ_NEXT(tp1, sctp_next);
                              continue;
                        }
                  }
                  if ((PR_SCTP_RTX_ENABLED(tp1->flags)) && tp1->sent < SCTP_DATAGRAM_ACKED) {
                        /* Has it been retransmitted tv_sec times? */
                        if (tp1->snd_count > tp1->rec.data.timetodrop.tv_sec) {
                              /* Yes, so drop it */
                              if (tp1->data != NULL) {
                                    (void)sctp_release_pr_sctp_chunk(stcb, tp1,
                                        (SCTP_RESPONSE_TO_USER_REQ | SCTP_NOTIFY_DATAGRAM_SENT),
                                        &asoc->sent_queue, SCTP_SO_NOT_LOCKED);
                              }
                              tp1 = TAILQ_NEXT(tp1, sctp_next);
                              continue;
                        }
                  }
            }
            if (compare_with_wrap(tp1->rec.data.TSN_seq,
                asoc->this_sack_highest_gap, MAX_TSN)) {
                  /* we are beyond the tsn in the sack  */
                  break;
            }
            if (tp1->sent >= SCTP_DATAGRAM_RESEND) {
                  /* either a RESEND, ACKED, or MARKED */
                  /* skip */
                  tp1 = TAILQ_NEXT(tp1, sctp_next);
                  continue;
            }
            /*
             * CMT : SFR algo (covers part of DAC and HTNA as well)
             */
            if (tp1->whoTo && tp1->whoTo->saw_newack == 0) {
                  /*
                   * No new acks were receieved for data sent to this
                   * dest. Therefore, according to the SFR algo for
                   * CMT, no data sent to this dest can be marked for
                   * FR using this SACK.
                   */
                  tp1 = TAILQ_NEXT(tp1, sctp_next);
                  continue;
            } else if (tp1->whoTo && compare_with_wrap(tp1->rec.data.TSN_seq,
                tp1->whoTo->this_sack_highest_newack, MAX_TSN)) {
                  /*
                   * CMT: New acks were receieved for data sent to
                   * this dest. But no new acks were seen for data
                   * sent after tp1. Therefore, according to the SFR
                   * algo for CMT, tp1 cannot be marked for FR using
                   * this SACK. This step covers part of the DAC algo
                   * and the HTNA algo as well.
                   */
                  tp1 = TAILQ_NEXT(tp1, sctp_next);
                  continue;
            }
            /*
             * Here we check to see if we were have already done a FR
             * and if so we see if the biggest TSN we saw in the sack is
             * smaller than the recovery point. If so we don't strike
             * the tsn... otherwise we CAN strike the TSN.
             */
            /*
             * @@@ JRI: Check for CMT if (accum_moved &&
             * asoc->fast_retran_loss_recovery && (sctp_cmt_on_off ==
             * 0)) {
             */
            if (accum_moved && asoc->fast_retran_loss_recovery) {
                  /*
                   * Strike the TSN if in fast-recovery and cum-ack
                   * moved.
                   */
                  if (sctp_logging_level & SCTP_FR_LOGGING_ENABLE) {
                        sctp_log_fr(biggest_tsn_newly_acked,
                            tp1->rec.data.TSN_seq,
                            tp1->sent,
                            SCTP_FR_LOG_STRIKE_CHUNK);
                  }
                  if (tp1->sent < SCTP_DATAGRAM_RESEND) {
                        tp1->sent++;
                  }
                  if (sctp_cmt_on_off && sctp_cmt_use_dac) {
                        /*
                         * CMT DAC algorithm: If SACK flag is set to
                         * 0, then lowest_newack test will not pass
                         * because it would have been set to the
                         * cumack earlier. If not already to be
                         * rtx'd, If not a mixed sack and if tp1 is
                         * not between two sacked TSNs, then mark by
                         * one more. NOTE that we are marking by one
                         * additional time since the SACK DAC flag
                         * indicates that two packets have been
                         * received after this missing TSN.
                         */
                        if ((tp1->sent < SCTP_DATAGRAM_RESEND) && (num_dests_sacked == 1) &&
                            compare_with_wrap(this_sack_lowest_newack, tp1->rec.data.TSN_seq, MAX_TSN)) {
                              if (sctp_logging_level & SCTP_FR_LOGGING_ENABLE) {
                                    sctp_log_fr(16 + num_dests_sacked,
                                        tp1->rec.data.TSN_seq,
                                        tp1->sent,
                                        SCTP_FR_LOG_STRIKE_CHUNK);
                              }
                              tp1->sent++;
                        }
                  }
            } else if (tp1->rec.data.doing_fast_retransmit) {
                  /*
                   * For those that have done a FR we must take
                   * special consideration if we strike. I.e the
                   * biggest_newly_acked must be higher than the
                   * sending_seq at the time we did the FR.
                   */
                  if (
#ifdef SCTP_FR_TO_ALTERNATE
                  /*
                   * If FR's go to new networks, then we must only do
                   * this for singly homed asoc's. However if the FR's
                   * go to the same network (Armando's work) then its
                   * ok to FR multiple times.
                   */
                      (asoc->numnets < 2)
#else
                      (1)
#endif
                      ) {

                        if ((compare_with_wrap(biggest_tsn_newly_acked,
                            tp1->rec.data.fast_retran_tsn, MAX_TSN)) ||
                            (biggest_tsn_newly_acked ==
                            tp1->rec.data.fast_retran_tsn)) {
                              /*
                               * Strike the TSN, since this ack is
                               * beyond where things were when we
                               * did a FR.
                               */
                              if (sctp_logging_level & SCTP_FR_LOGGING_ENABLE) {
                                    sctp_log_fr(biggest_tsn_newly_acked,
                                        tp1->rec.data.TSN_seq,
                                        tp1->sent,
                                        SCTP_FR_LOG_STRIKE_CHUNK);
                              }
                              if (tp1->sent < SCTP_DATAGRAM_RESEND) {
                                    tp1->sent++;
                              }
                              strike_flag = 1;
                              if (sctp_cmt_on_off && sctp_cmt_use_dac) {
                                    /*
                                     * CMT DAC algorithm: If
                                     * SACK flag is set to 0,
                                     * then lowest_newack test
                                     * will not pass because it
                                     * would have been set to
                                     * the cumack earlier. If
                                     * not already to be rtx'd,
                                     * If not a mixed sack and
                                     * if tp1 is not between two
                                     * sacked TSNs, then mark by
                                     * one more. NOTE that we
                                     * are marking by one
                                     * additional time since the
                                     * SACK DAC flag indicates
                                     * that two packets have
                                     * been received after this
                                     * missing TSN.
                                     */
                                    if ((tp1->sent < SCTP_DATAGRAM_RESEND) &&
                                        (num_dests_sacked == 1) &&
                                        compare_with_wrap(this_sack_lowest_newack,
                                        tp1->rec.data.TSN_seq, MAX_TSN)) {
                                          if (sctp_logging_level & SCTP_FR_LOGGING_ENABLE) {
                                                sctp_log_fr(32 + num_dests_sacked,
                                                    tp1->rec.data.TSN_seq,
                                                    tp1->sent,
                                                    SCTP_FR_LOG_STRIKE_CHUNK);
                                          }
                                          if (tp1->sent < SCTP_DATAGRAM_RESEND) {
                                                tp1->sent++;
                                          }
                                    }
                              }
                        }
                  }
                  /*
                   * JRI: TODO: remove code for HTNA algo. CMT's SFR
                   * algo covers HTNA.
                   */
            } else if (compare_with_wrap(tp1->rec.data.TSN_seq,
                biggest_tsn_newly_acked, MAX_TSN)) {
                  /*
                   * We don't strike these: This is the  HTNA
                   * algorithm i.e. we don't strike If our TSN is
                   * larger than the Highest TSN Newly Acked.
                   */
                  ;
            } else {
                  /* Strike the TSN */
                  if (sctp_logging_level & SCTP_FR_LOGGING_ENABLE) {
                        sctp_log_fr(biggest_tsn_newly_acked,
                            tp1->rec.data.TSN_seq,
                            tp1->sent,
                            SCTP_FR_LOG_STRIKE_CHUNK);
                  }
                  if (tp1->sent < SCTP_DATAGRAM_RESEND) {
                        tp1->sent++;
                  }
                  if (sctp_cmt_on_off && sctp_cmt_use_dac) {
                        /*
                         * CMT DAC algorithm: If SACK flag is set to
                         * 0, then lowest_newack test will not pass
                         * because it would have been set to the
                         * cumack earlier. If not already to be
                         * rtx'd, If not a mixed sack and if tp1 is
                         * not between two sacked TSNs, then mark by
                         * one more. NOTE that we are marking by one
                         * additional time since the SACK DAC flag
                         * indicates that two packets have been
                         * received after this missing TSN.
                         */
                        if ((tp1->sent < SCTP_DATAGRAM_RESEND) && (num_dests_sacked == 1) &&
                            compare_with_wrap(this_sack_lowest_newack, tp1->rec.data.TSN_seq, MAX_TSN)) {
                              if (sctp_logging_level & SCTP_FR_LOGGING_ENABLE) {
                                    sctp_log_fr(48 + num_dests_sacked,
                                        tp1->rec.data.TSN_seq,
                                        tp1->sent,
                                        SCTP_FR_LOG_STRIKE_CHUNK);
                              }
                              tp1->sent++;
                        }
                  }
            }
            if (tp1->sent == SCTP_DATAGRAM_RESEND) {
                  /* Increment the count to resend */
                  struct sctp_nets *alt;

                  /* printf("OK, we are now ready to FR this guy\n"); */
                  if (sctp_logging_level & SCTP_FR_LOGGING_ENABLE) {
                        sctp_log_fr(tp1->rec.data.TSN_seq, tp1->snd_count,
                            0, SCTP_FR_MARKED);
                  }
                  if (strike_flag) {
                        /* This is a subsequent FR */
                        SCTP_STAT_INCR(sctps_sendmultfastretrans);
                  }
                  sctp_ucount_incr(stcb->asoc.sent_queue_retran_cnt);
                  if (sctp_cmt_on_off) {
                        /*
                         * CMT: Using RTX_SSTHRESH policy for CMT.
                         * If CMT is being used, then pick dest with
                         * largest ssthresh for any retransmission.
                         */
                        tp1->no_fr_allowed = 1;
                        alt = tp1->whoTo;
                        /* sa_ignore NO_NULL_CHK */
                        if (sctp_cmt_on_off && sctp_cmt_pf) {
                              /*
                               * JRS 5/18/07 - If CMT PF is on,
                               * use the PF version of
                               * find_alt_net()
                               */
                              alt = sctp_find_alternate_net(stcb, alt, 2);
                        } else {
                              /*
                               * JRS 5/18/07 - If only CMT is on,
                               * use the CMT version of
                               * find_alt_net()
                               */
                              /* sa_ignore NO_NULL_CHK */
                              alt = sctp_find_alternate_net(stcb, alt, 1);
                        }
                        if (alt == NULL) {
                              alt = tp1->whoTo;
                        }
                        /*
                         * CUCv2: If a different dest is picked for
                         * the retransmission, then new
                         * (rtx-)pseudo_cumack needs to be tracked
                         * for orig dest. Let CUCv2 track new (rtx-)
                         * pseudo-cumack always.
                         */
                        if (tp1->whoTo) {
                              tp1->whoTo->find_pseudo_cumack = 1;
                              tp1->whoTo->find_rtx_pseudo_cumack = 1;
                        }
                  } else {/* CMT is OFF */

#ifdef SCTP_FR_TO_ALTERNATE
                        /* Can we find an alternate? */
                        alt = sctp_find_alternate_net(stcb, tp1->whoTo, 0);
#else
                        /*
                         * default behavior is to NOT retransmit
                         * FR's to an alternate. Armando Caro's
                         * paper details why.
                         */
                        alt = tp1->whoTo;
#endif
                  }

                  tp1->rec.data.doing_fast_retransmit = 1;
                  tot_retrans++;
                  /* mark the sending seq for possible subsequent FR's */
                  /*
                   * printf("Marking TSN for FR new value %x\n",
                   * (uint32_t)tpi->rec.data.TSN_seq);
                   */
                  if (TAILQ_EMPTY(&asoc->send_queue)) {
                        /*
                         * If the queue of send is empty then its
                         * the next sequence number that will be
                         * assigned so we subtract one from this to
                         * get the one we last sent.
                         */
                        tp1->rec.data.fast_retran_tsn = sending_seq;
                  } else {
                        /*
                         * If there are chunks on the send queue
                         * (unsent data that has made it from the
                         * stream queues but not out the door, we
                         * take the first one (which will have the
                         * lowest TSN) and subtract one to get the
                         * one we last sent.
                         */
                        struct sctp_tmit_chunk *ttt;

                        ttt = TAILQ_FIRST(&asoc->send_queue);
                        tp1->rec.data.fast_retran_tsn =
                            ttt->rec.data.TSN_seq;
                  }

                  if (tp1->do_rtt) {
                        /*
                         * this guy had a RTO calculation pending on
                         * it, cancel it
                         */
                        tp1->do_rtt = 0;
                  }
                  /* fix counts and things */
                  if (sctp_logging_level & SCTP_FLIGHT_LOGGING_ENABLE) {
                        sctp_misc_ints(SCTP_FLIGHT_LOG_DOWN_RSND,
                            (tp1->whoTo ? (tp1->whoTo->flight_size) : 0),
                            tp1->book_size,
                            (uintptr_t) tp1->whoTo,
                            tp1->rec.data.TSN_seq);
                  }
                  if (tp1->whoTo) {
                        tp1->whoTo->net_ack++;
                        sctp_flight_size_decrease(tp1);
                  }
                  if (sctp_logging_level & SCTP_LOG_RWND_ENABLE) {
                        sctp_log_rwnd(SCTP_INCREASE_PEER_RWND,
                            asoc->peers_rwnd, tp1->send_size, sctp_peer_chunk_oh);
                  }
                  /* add back to the rwnd */
                  asoc->peers_rwnd += (tp1->send_size + sctp_peer_chunk_oh);

                  /* remove from the total flight */
                  sctp_total_flight_decrease(stcb, tp1);
                  if (alt != tp1->whoTo) {
                        /* yes, there is an alternate. */
                        sctp_free_remote_addr(tp1->whoTo);
                        /* sa_ignore FREED_MEMORY */
                        tp1->whoTo = alt;
                        atomic_add_int(&alt->ref_count, 1);
                  }
            }
            tp1 = TAILQ_NEXT(tp1, sctp_next);
      }                 /* while (tp1) */

      if (tot_retrans > 0) {
            /*
             * Setup the ecn nonce re-sync point. We do this since once
             * we go to FR something we introduce a Karn's rule scenario
             * and won't know the totals for the ECN bits.
             */
            asoc->nonce_resync_tsn = sending_seq;
            asoc->nonce_wait_for_ecne = 0;
            asoc->nonce_sum_check = 0;
      }
}

struct sctp_tmit_chunk *
sctp_try_advance_peer_ack_point(struct sctp_tcb *stcb,
    struct sctp_association *asoc)
{
      struct sctp_tmit_chunk *tp1, *tp2, *a_adv = NULL;
      struct timeval now;
      int now_filled = 0;

      if (asoc->peer_supports_prsctp == 0) {
            return (NULL);
      }
      tp1 = TAILQ_FIRST(&asoc->sent_queue);
      while (tp1) {
            if (tp1->sent != SCTP_FORWARD_TSN_SKIP &&
                tp1->sent != SCTP_DATAGRAM_RESEND) {
                  /* no chance to advance, out of here */
                  break;
            }
            if (!PR_SCTP_ENABLED(tp1->flags)) {
                  /*
                   * We can't fwd-tsn past any that are reliable aka
                   * retransmitted until the asoc fails.
                   */
                  break;
            }
            if (!now_filled) {
                  (void)SCTP_GETTIME_TIMEVAL(&now);
                  now_filled = 1;
            }
            tp2 = TAILQ_NEXT(tp1, sctp_next);
            /*
             * now we got a chunk which is marked for another
             * retransmission to a PR-stream but has run out its chances
             * already maybe OR has been marked to skip now. Can we skip
             * it if its a resend?
             */
            if (tp1->sent == SCTP_DATAGRAM_RESEND &&
                (PR_SCTP_TTL_ENABLED(tp1->flags))) {
                  /*
                   * Now is this one marked for resend and its time is
                   * now up?
                   */
                  if (timevalcmp(&now, &tp1->rec.data.timetodrop, >)) {
                        /* Yes so drop it */
                        if (tp1->data) {
                              (void)sctp_release_pr_sctp_chunk(stcb, tp1,
                                  (SCTP_RESPONSE_TO_USER_REQ | SCTP_NOTIFY_DATAGRAM_SENT),
                                  &asoc->sent_queue, SCTP_SO_NOT_LOCKED);
                        }
                  } else {
                        /*
                         * No, we are done when hit one for resend
                         * whos time as not expired.
                         */
                        break;
                  }
            }
            /*
             * Ok now if this chunk is marked to drop it we can clean up
             * the chunk, advance our peer ack point and we can check
             * the next chunk.
             */
            if (tp1->sent == SCTP_FORWARD_TSN_SKIP) {
                  /* advance PeerAckPoint goes forward */
                  asoc->advanced_peer_ack_point = tp1->rec.data.TSN_seq;
                  a_adv = tp1;
                  /*
                   * we don't want to de-queue it here. Just wait for
                   * the next peer SACK to come with a new cumTSN and
                   * then the chunk will be droped in the normal
                   * fashion.
                   */
                  if (tp1->data) {
                        sctp_free_bufspace(stcb, asoc, tp1, 1);
                        /*
                         * Maybe there should be another
                         * notification type
                         */
                        sctp_ulp_notify(SCTP_NOTIFY_DG_FAIL, stcb,
                            (SCTP_RESPONSE_TO_USER_REQ | SCTP_NOTIFY_DATAGRAM_SENT),
                            tp1, SCTP_SO_NOT_LOCKED);
                        sctp_m_freem(tp1->data);
                        tp1->data = NULL;
                        if (stcb->sctp_socket) {
#if defined (__APPLE__) || defined(SCTP_SO_LOCK_TESTING)
                              struct socket *so;

                              so = SCTP_INP_SO(stcb->sctp_ep);
                              atomic_add_int(&stcb->asoc.refcnt, 1);
                              SCTP_TCB_UNLOCK(stcb);
                              SCTP_SOCKET_LOCK(so, 1);
                              SCTP_TCB_LOCK(stcb);
                              atomic_subtract_int(&stcb->asoc.refcnt, 1);
                              if (stcb->asoc.state & SCTP_STATE_CLOSED_SOCKET) {
                                    /*
                                     * assoc was freed while we
                                     * were unlocked
                                     */
                                    SCTP_SOCKET_UNLOCK(so, 1);
                                    return (NULL);
                              }
#endif
                              sctp_sowwakeup(stcb->sctp_ep, stcb->sctp_socket);
#if defined (__APPLE__) || defined(SCTP_SO_LOCK_TESTING)
                              SCTP_SOCKET_UNLOCK(so, 1);
#endif
                              if (sctp_logging_level & SCTP_WAKE_LOGGING_ENABLE) {
                                    sctp_wakeup_log(stcb, tp1->rec.data.TSN_seq, 1, SCTP_WAKESND_FROM_FWDTSN);
                              }
                        }
                  }
            } else {
                  /*
                   * If it is still in RESEND we can advance no
                   * further
                   */
                  break;
            }
            /*
             * If we hit here we just dumped tp1, move to next tsn on
             * sent queue.
             */
            tp1 = tp2;
      }
      return (a_adv);
}

static void
sctp_fs_audit(struct sctp_association *asoc)
{
      struct sctp_tmit_chunk *chk;
      int inflight = 0, resend = 0, inbetween = 0, acked = 0, above = 0;

      TAILQ_FOREACH(chk, &asoc->sent_queue, sctp_next) {
            if (chk->sent < SCTP_DATAGRAM_RESEND) {
                  inflight++;
            } else if (chk->sent == SCTP_DATAGRAM_RESEND) {
                  resend++;
            } else if (chk->sent < SCTP_DATAGRAM_ACKED) {
                  inbetween++;
            } else if (chk->sent > SCTP_DATAGRAM_ACKED) {
                  above++;
            } else {
                  acked++;
            }
      }

      if ((inflight > 0) || (inbetween > 0)) {
#ifdef INVARIANTS
            panic("Flight size-express incorrect? \n");
#else
            SCTP_PRINTF("Flight size-express incorrect inflight:%d inbetween:%d\n",
                inflight, inbetween);
#endif
      }
}


static void
sctp_window_probe_recovery(struct sctp_tcb *stcb,
    struct sctp_association *asoc,
    struct sctp_nets *net,
    struct sctp_tmit_chunk *tp1)
{
      struct sctp_tmit_chunk *chk;

      /* First setup this one and get it moved back */
      tp1->sent = SCTP_DATAGRAM_UNSENT;
      if (sctp_logging_level & SCTP_FLIGHT_LOGGING_ENABLE) {
            sctp_misc_ints(SCTP_FLIGHT_LOG_DOWN_WP,
                tp1->whoTo->flight_size,
                tp1->book_size,
                (uintptr_t) tp1->whoTo,
                tp1->rec.data.TSN_seq);
      }
      sctp_flight_size_decrease(tp1);
      sctp_total_flight_decrease(stcb, tp1);
      TAILQ_REMOVE(&asoc->sent_queue, tp1, sctp_next);
      TAILQ_INSERT_HEAD(&asoc->send_queue, tp1, sctp_next);
      asoc->sent_queue_cnt--;
      asoc->send_queue_cnt++;
      /*
       * Now all guys marked for RESEND on the sent_queue must be moved
       * back too.
       */
      TAILQ_FOREACH(chk, &asoc->sent_queue, sctp_next) {
            if (chk->sent == SCTP_DATAGRAM_RESEND) {
                  /* Another chunk to move */
                  chk->sent = SCTP_DATAGRAM_UNSENT;
                  /* It should not be in flight */
                  TAILQ_REMOVE(&asoc->sent_queue, chk, sctp_next);
                  TAILQ_INSERT_AFTER(&asoc->send_queue, tp1, chk, sctp_next);
                  asoc->sent_queue_cnt--;
                  asoc->send_queue_cnt++;
                  sctp_ucount_decr(asoc->sent_queue_retran_cnt);
            }
      }
}

void
sctp_express_handle_sack(struct sctp_tcb *stcb, uint32_t cumack,
    uint32_t rwnd, int nonce_sum_flag, int *abort_now)
{
      struct sctp_nets *net;
      struct sctp_association *asoc;
      struct sctp_tmit_chunk *tp1, *tp2;
      uint32_t old_rwnd;
      int win_probe_recovery = 0;
      int win_probe_recovered = 0;
      int j, done_once = 0;

      if (sctp_logging_level & SCTP_LOG_SACK_ARRIVALS_ENABLE) {
            sctp_misc_ints(SCTP_SACK_LOG_EXPRESS, cumack,
                rwnd, stcb->asoc.last_acked_seq, stcb->asoc.peers_rwnd);
      }
      SCTP_TCB_LOCK_ASSERT(stcb);
#ifdef SCTP_ASOCLOG_OF_TSNS
      stcb->asoc.cumack_log[stcb->asoc.cumack_log_at] = cumack;
      stcb->asoc.cumack_log_at++;
      if (stcb->asoc.cumack_log_at > SCTP_TSN_LOG_SIZE) {
            stcb->asoc.cumack_log_at = 0;
      }
#endif
      asoc = &stcb->asoc;
      old_rwnd = asoc->peers_rwnd;
      if (compare_with_wrap(asoc->last_acked_seq, cumack, MAX_TSN)) {
            /* old ack */
            return;
      } else if (asoc->last_acked_seq == cumack) {
            /* Window update sack */
            asoc->peers_rwnd = sctp_sbspace_sub(rwnd,
                (uint32_t) (asoc->total_flight + (asoc->sent_queue_cnt * sctp_peer_chunk_oh)));
            if (asoc->peers_rwnd < stcb->sctp_ep->sctp_ep.sctp_sws_sender) {
                  /* SWS sender side engages */
                  asoc->peers_rwnd = 0;
            }
            if (asoc->peers_rwnd > old_rwnd) {
                  goto again;
            }
            return;
      }
      /* First setup for CC stuff */
      TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
            net->prev_cwnd = net->cwnd;
            net->net_ack = 0;
            net->net_ack2 = 0;

            /*
             * CMT: Reset CUC and Fast recovery algo variables before
             * SACK processing
             */
            net->new_pseudo_cumack = 0;
            net->will_exit_fast_recovery = 0;
      }
      if (sctp_strict_sacks) {
            uint32_t send_s;

            if (!TAILQ_EMPTY(&asoc->sent_queue)) {
                  tp1 = TAILQ_LAST(&asoc->sent_queue,
                      sctpchunk_listhead);
                  send_s = tp1->rec.data.TSN_seq + 1;
            } else {
                  send_s = asoc->sending_seq;
            }
            if ((cumack == send_s) ||
                compare_with_wrap(cumack, send_s, MAX_TSN)) {
#ifndef INVARIANTS
                  struct mbuf *oper;

#endif
#ifdef INVARIANTS
                  panic("Impossible sack 1");
#else
                  *abort_now = 1;
                  /* XXX */
                  oper = sctp_get_mbuf_for_msg((sizeof(struct sctp_paramhdr) + sizeof(uint32_t)),
                      0, M_DONTWAIT, 1, MT_DATA);
                  if (oper) {
                        struct sctp_paramhdr *ph;
                        uint32_t *ippp;

                        SCTP_BUF_LEN(oper) = sizeof(struct sctp_paramhdr) +
                            sizeof(uint32_t);
                        ph = mtod(oper, struct sctp_paramhdr *);
                        ph->param_type = htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                        ph->param_length = htons(SCTP_BUF_LEN(oper));
                        ippp = (uint32_t *) (ph + 1);
                        *ippp = htonl(SCTP_FROM_SCTP_INDATA + SCTP_LOC_25);
                  }
                  stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_25;
                  sctp_abort_an_association(stcb->sctp_ep, stcb, SCTP_PEER_FAULTY, oper, SCTP_SO_NOT_LOCKED);
                  return;
#endif
            }
      }
      asoc->this_sack_highest_gap = cumack;
      if (sctp_logging_level & SCTP_THRESHOLD_LOGGING) {
            sctp_misc_ints(SCTP_THRESHOLD_CLEAR,
                stcb->asoc.overall_error_count,
                0,
                SCTP_FROM_SCTP_INDATA,
                __LINE__);
      }
      stcb->asoc.overall_error_count = 0;
      if (compare_with_wrap(cumack, asoc->last_acked_seq, MAX_TSN)) {
            /* process the new consecutive TSN first */
            tp1 = TAILQ_FIRST(&asoc->sent_queue);
            while (tp1) {
                  tp2 = TAILQ_NEXT(tp1, sctp_next);
                  if (compare_with_wrap(cumack, tp1->rec.data.TSN_seq,
                      MAX_TSN) ||
                      cumack == tp1->rec.data.TSN_seq) {
                        if (tp1->sent == SCTP_DATAGRAM_UNSENT) {
                              printf("Warning, an unsent is now acked?\n");
                        }
                        /*
                         * ECN Nonce: Add the nonce to the sender's
                         * nonce sum
                         */
                        asoc->nonce_sum_expect_base += tp1->rec.data.ect_nonce;
                        if (tp1->sent < SCTP_DATAGRAM_ACKED) {
                              /*
                               * If it is less than ACKED, it is
                               * now no-longer in flight. Higher
                               * values may occur during marking
                               */
                              if (tp1->sent < SCTP_DATAGRAM_RESEND) {
                                    if (sctp_logging_level & SCTP_FLIGHT_LOGGING_ENABLE) {
                                          sctp_misc_ints(SCTP_FLIGHT_LOG_DOWN_CA,
                                              tp1->whoTo->flight_size,
                                              tp1->book_size,
                                              (uintptr_t) tp1->whoTo,
                                              tp1->rec.data.TSN_seq);
                                    }
                                    sctp_flight_size_decrease(tp1);
                                    /* sa_ignore NO_NULL_CHK */
                                    sctp_total_flight_decrease(stcb, tp1);
                              }
                              tp1->whoTo->net_ack += tp1->send_size;
                              if (tp1->snd_count < 2) {
                                    /*
                                     * True non-retransmited
                                     * chunk
                                     */
                                    tp1->whoTo->net_ack2 +=
                                        tp1->send_size;

                                    /* update RTO too? */
                                    if (tp1->do_rtt) {
                                          tp1->whoTo->RTO =
                                          /*
                                           * sa_ignore
                                           * NO_NULL_CHK
                                           */
                                              sctp_calculate_rto(stcb,
                                              asoc, tp1->whoTo,
                                              &tp1->sent_rcv_time,
                                              sctp_align_safe_nocopy);
                                          tp1->do_rtt = 0;
                                    }
                              }
                              /*
                               * CMT: CUCv2 algorithm. From the
                               * cumack'd TSNs, for each TSN being
                               * acked for the first time, set the
                               * following variables for the
                               * corresp destination.
                               * new_pseudo_cumack will trigger a
                               * cwnd update.
                               * find_(rtx_)pseudo_cumack will
                               * trigger search for the next
                               * expected (rtx-)pseudo-cumack.
                               */
                              tp1->whoTo->new_pseudo_cumack = 1;
                              tp1->whoTo->find_pseudo_cumack = 1;
                              tp1->whoTo->find_rtx_pseudo_cumack = 1;

                              if (sctp_logging_level & SCTP_CWND_LOGGING_ENABLE) {
                                    /* sa_ignore NO_NULL_CHK */
                                    sctp_log_cwnd(stcb, tp1->whoTo, tp1->rec.data.TSN_seq, SCTP_CWND_LOG_FROM_SACK);
                              }
                        }
                        if (tp1->sent == SCTP_DATAGRAM_RESEND) {
                              sctp_ucount_decr(asoc->sent_queue_retran_cnt);
                        }
                        if (tp1->rec.data.chunk_was_revoked) {
                              /* deflate the cwnd */
                              tp1->whoTo->cwnd -= tp1->book_size;
                              tp1->rec.data.chunk_was_revoked = 0;
                        }
                        tp1->sent = SCTP_DATAGRAM_ACKED;
                        TAILQ_REMOVE(&asoc->sent_queue, tp1, sctp_next);
                        if (tp1->data) {
                              /* sa_ignore NO_NULL_CHK */
                              sctp_free_bufspace(stcb, asoc, tp1, 1);
                              sctp_m_freem(tp1->data);
                        }
                        if (sctp_logging_level & SCTP_SACK_LOGGING_ENABLE) {
                              sctp_log_sack(asoc->last_acked_seq,
                                  cumack,
                                  tp1->rec.data.TSN_seq,
                                  0,
                                  0,
                                  SCTP_LOG_FREE_SENT);
                        }
                        tp1->data = NULL;
                        asoc->sent_queue_cnt--;
                        sctp_free_a_chunk(stcb, tp1);
                        tp1 = tp2;
                  } else {
                        break;
                  }
            }

      }
      /* sa_ignore NO_NULL_CHK */
      if (stcb->sctp_socket) {
#if defined (__APPLE__) || defined(SCTP_SO_LOCK_TESTING)
            struct socket *so;

#endif

            SOCKBUF_LOCK(&stcb->sctp_socket->so_snd);
            if (sctp_logging_level & SCTP_WAKE_LOGGING_ENABLE) {
                  /* sa_ignore NO_NULL_CHK */
                  sctp_wakeup_log(stcb, cumack, 1, SCTP_WAKESND_FROM_SACK);
            }
#if defined (__APPLE__) || defined(SCTP_SO_LOCK_TESTING)
            so = SCTP_INP_SO(stcb->sctp_ep);
            atomic_add_int(&stcb->asoc.refcnt, 1);
            SCTP_TCB_UNLOCK(stcb);
            SCTP_SOCKET_LOCK(so, 1);
            SCTP_TCB_LOCK(stcb);
            atomic_subtract_int(&stcb->asoc.refcnt, 1);
            if (stcb->asoc.state & SCTP_STATE_CLOSED_SOCKET) {
                  /* assoc was freed while we were unlocked */
                  SCTP_SOCKET_UNLOCK(so, 1);
                  return;
            }
#endif
            sctp_sowwakeup_locked(stcb->sctp_ep, stcb->sctp_socket);
#if defined (__APPLE__) || defined(SCTP_SO_LOCK_TESTING)
            SCTP_SOCKET_UNLOCK(so, 1);
#endif
      } else {
            if (sctp_logging_level & SCTP_WAKE_LOGGING_ENABLE) {
                  sctp_wakeup_log(stcb, cumack, 1, SCTP_NOWAKE_FROM_SACK);
            }
      }

      /* JRS - Use the congestion control given in the CC module */
      if (asoc->last_acked_seq != cumack)
            asoc->cc_functions.sctp_cwnd_update_after_sack(stcb, asoc, 1, 0, 0);

      asoc->last_acked_seq = cumack;

      if (TAILQ_EMPTY(&asoc->sent_queue)) {
            /* nothing left in-flight */
            TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                  net->flight_size = 0;
                  net->partial_bytes_acked = 0;
            }
            asoc->total_flight = 0;
            asoc->total_flight_count = 0;
      }
      /* Fix up the a-p-a-p for future PR-SCTP sends */
      if (compare_with_wrap(cumack, asoc->advanced_peer_ack_point, MAX_TSN)) {
            asoc->advanced_peer_ack_point = cumack;
      }
      /* ECN Nonce updates */
      if (asoc->ecn_nonce_allowed) {
            if (asoc->nonce_sum_check) {
                  if (nonce_sum_flag != ((asoc->nonce_sum_expect_base) & SCTP_SACK_NONCE_SUM)) {
                        if (asoc->nonce_wait_for_ecne == 0) {
                              struct sctp_tmit_chunk *lchk;

                              lchk = TAILQ_FIRST(&asoc->send_queue);
                              asoc->nonce_wait_for_ecne = 1;
                              if (lchk) {
                                    asoc->nonce_wait_tsn = lchk->rec.data.TSN_seq;
                              } else {
                                    asoc->nonce_wait_tsn = asoc->sending_seq;
                              }
                        } else {
                              if (compare_with_wrap(asoc->last_acked_seq, asoc->nonce_wait_tsn, MAX_TSN) ||
                                  (asoc->last_acked_seq == asoc->nonce_wait_tsn)) {
                                    /*
                                     * Misbehaving peer. We need
                                     * to react to this guy
                                     */
                                    asoc->ecn_allowed = 0;
                                    asoc->ecn_nonce_allowed = 0;
                              }
                        }
                  }
            } else {
                  /* See if Resynchronization Possible */
                  if (compare_with_wrap(asoc->last_acked_seq, asoc->nonce_resync_tsn, MAX_TSN)) {
                        asoc->nonce_sum_check = 1;
                        /*
                         * now we must calculate what the base is.
                         * We do this based on two things, we know
                         * the total's for all the segments
                         * gap-acked in the SACK (none), We also
                         * know the SACK's nonce sum, its in
                         * nonce_sum_flag. So we can build a truth
                         * table to back-calculate the new value of
                         * asoc->nonce_sum_expect_base:
                         * 
                         * SACK-flag-Value         Seg-Sums Base 0 0 0
                         * 1                    0 1 0 1 1 1
                         * 1 0
                         */
                        asoc->nonce_sum_expect_base = (0 ^ nonce_sum_flag) & SCTP_SACK_NONCE_SUM;
                  }
            }
      }
      /* RWND update */
      asoc->peers_rwnd = sctp_sbspace_sub(rwnd,
          (uint32_t) (asoc->total_flight + (asoc->sent_queue_cnt * sctp_peer_chunk_oh)));
      if (asoc->peers_rwnd < stcb->sctp_ep->sctp_ep.sctp_sws_sender) {
            /* SWS sender side engages */
            asoc->peers_rwnd = 0;
      }
      if (asoc->peers_rwnd > old_rwnd) {
            win_probe_recovery = 1;
      }
      /* Now assure a timer where data is queued at */
again:
      j = 0;
      TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
            if (win_probe_recovery && (net->window_probe)) {
                  net->window_probe = 0;
                  win_probe_recovered = 1;
                  /*
                   * Find first chunk that was used with window probe
                   * and clear the sent
                   */
                  /* sa_ignore FREED_MEMORY */
                  TAILQ_FOREACH(tp1, &asoc->sent_queue, sctp_next) {
                        if (tp1->window_probe) {
                              /* move back to data send queue */
                              sctp_window_probe_recovery(stcb, asoc, net, tp1);
                              break;
                        }
                  }
            }
            if (net->flight_size) {
                  int to_ticks;

                  if (net->RTO == 0) {
                        to_ticks = MSEC_TO_TICKS(stcb->asoc.initial_rto);
                  } else {
                        to_ticks = MSEC_TO_TICKS(net->RTO);
                  }
                  j++;
                  (void)SCTP_OS_TIMER_START(&net->rxt_timer.timer, to_ticks,
                      sctp_timeout_handler, &net->rxt_timer);
            } else {
                  if (SCTP_OS_TIMER_PENDING(&net->rxt_timer.timer)) {
                        sctp_timer_stop(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep,
                            stcb, net,
                            SCTP_FROM_SCTP_INDATA + SCTP_LOC_22);
                  }
                  if (sctp_early_fr) {
                        if (SCTP_OS_TIMER_PENDING(&net->fr_timer.timer)) {
                              SCTP_STAT_INCR(sctps_earlyfrstpidsck4);
                              sctp_timer_stop(SCTP_TIMER_TYPE_EARLYFR, stcb->sctp_ep, stcb, net,
                                  SCTP_FROM_SCTP_INDATA + SCTP_LOC_23);
                        }
                  }
            }
      }
      if ((j == 0) &&
          (!TAILQ_EMPTY(&asoc->sent_queue)) &&
          (asoc->sent_queue_retran_cnt == 0) &&
          (win_probe_recovered == 0) &&
          (done_once == 0)) {
            /* huh, this should not happen */
            sctp_fs_audit(asoc);
            TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                  net->flight_size = 0;
            }
            asoc->total_flight = 0;
            asoc->total_flight_count = 0;
            asoc->sent_queue_retran_cnt = 0;
            TAILQ_FOREACH(tp1, &asoc->sent_queue, sctp_next) {
                  if (tp1->sent < SCTP_DATAGRAM_RESEND) {
                        sctp_flight_size_increase(tp1);
                        sctp_total_flight_increase(stcb, tp1);
                  } else if (tp1->sent == SCTP_DATAGRAM_RESEND) {
                        asoc->sent_queue_retran_cnt++;
                  }
            }
            done_once = 1;
            goto again;
      }
      /**********************************/
      /* Now what about shutdown issues */
      /**********************************/
      if (TAILQ_EMPTY(&asoc->send_queue) && TAILQ_EMPTY(&asoc->sent_queue)) {
            /* nothing left on sendqueue.. consider done */
            /* clean up */
            if ((asoc->stream_queue_cnt == 1) &&
                ((asoc->state & SCTP_STATE_SHUTDOWN_PENDING) ||
                (asoc->state & SCTP_STATE_SHUTDOWN_RECEIVED)) &&
                (asoc->locked_on_sending)
                ) {
                  struct sctp_stream_queue_pending *sp;

                  /*
                   * I may be in a state where we got all across.. but
                   * cannot write more due to a shutdown... we abort
                   * since the user did not indicate EOR in this case.
                   * The sp will be cleaned during free of the asoc.
                   */
                  sp = TAILQ_LAST(&((asoc->locked_on_sending)->outqueue),
                      sctp_streamhead);
                  if ((sp) && (sp->length == 0)) {
                        /* Let cleanup code purge it */
                        if (sp->msg_is_complete) {
                              asoc->stream_queue_cnt--;
                        } else {
                              asoc->state |= SCTP_STATE_PARTIAL_MSG_LEFT;
                              asoc->locked_on_sending = NULL;
                              asoc->stream_queue_cnt--;
                        }
                  }
            }
            if ((asoc->state & SCTP_STATE_SHUTDOWN_PENDING) &&
                (asoc->stream_queue_cnt == 0)) {
                  if (asoc->state & SCTP_STATE_PARTIAL_MSG_LEFT) {
                        /* Need to abort here */
                        struct mbuf *oper;

            abort_out_now:
                        *abort_now = 1;
                        /* XXX */
                        oper = sctp_get_mbuf_for_msg((sizeof(struct sctp_paramhdr) + sizeof(uint32_t)),
                            0, M_DONTWAIT, 1, MT_DATA);
                        if (oper) {
                              struct sctp_paramhdr *ph;
                              uint32_t *ippp;

                              SCTP_BUF_LEN(oper) = sizeof(struct sctp_paramhdr) +
                                  sizeof(uint32_t);
                              ph = mtod(oper, struct sctp_paramhdr *);
                              ph->param_type = htons(SCTP_CAUSE_USER_INITIATED_ABT);
                              ph->param_length = htons(SCTP_BUF_LEN(oper));
                              ippp = (uint32_t *) (ph + 1);
                              *ippp = htonl(SCTP_FROM_SCTP_INDATA + SCTP_LOC_24);
                        }
                        stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_24;
                        sctp_abort_an_association(stcb->sctp_ep, stcb, SCTP_RESPONSE_TO_USER_REQ, oper, SCTP_SO_NOT_LOCKED);
                  } else {
                        if ((SCTP_GET_STATE(asoc) == SCTP_STATE_OPEN) ||
                            (SCTP_GET_STATE(asoc) == SCTP_STATE_SHUTDOWN_RECEIVED)) {
                              SCTP_STAT_DECR_GAUGE32(sctps_currestab);
                        }
                        SCTP_SET_STATE(asoc, SCTP_STATE_SHUTDOWN_SENT);
                        SCTP_CLEAR_SUBSTATE(asoc, SCTP_STATE_SHUTDOWN_PENDING);
                        sctp_stop_timers_for_shutdown(stcb);
                        sctp_send_shutdown(stcb,
                            stcb->asoc.primary_destination);
                        sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWN,
                            stcb->sctp_ep, stcb, asoc->primary_destination);
                        sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWNGUARD,
                            stcb->sctp_ep, stcb, asoc->primary_destination);
                  }
            } else if ((SCTP_GET_STATE(asoc) == SCTP_STATE_SHUTDOWN_RECEIVED) &&
                (asoc->stream_queue_cnt == 0)) {
                  if (asoc->state & SCTP_STATE_PARTIAL_MSG_LEFT) {
                        goto abort_out_now;
                  }
                  SCTP_STAT_DECR_GAUGE32(sctps_currestab);
                  SCTP_SET_STATE(asoc, SCTP_STATE_SHUTDOWN_ACK_SENT);
                  SCTP_CLEAR_SUBSTATE(asoc, SCTP_STATE_SHUTDOWN_PENDING);
                  sctp_send_shutdown_ack(stcb,
                      stcb->asoc.primary_destination);

                  sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWNACK,
                      stcb->sctp_ep, stcb, asoc->primary_destination);
            }
      }
      if (sctp_logging_level & SCTP_SACK_RWND_LOGGING_ENABLE) {
            sctp_misc_ints(SCTP_SACK_RWND_UPDATE,
                rwnd,
                stcb->asoc.peers_rwnd,
                stcb->asoc.total_flight,
                stcb->asoc.total_output_queue_size);
      }
}

void
sctp_handle_sack(struct mbuf *m, int offset,
    struct sctp_sack_chunk *ch, struct sctp_tcb *stcb,
    struct sctp_nets *net_from, int *abort_now, int sack_len, uint32_t rwnd)
{
      struct sctp_association *asoc;
      struct sctp_sack *sack;
      struct sctp_tmit_chunk *tp1, *tp2;
      uint32_t cum_ack, last_tsn, biggest_tsn_acked, biggest_tsn_newly_acked,
               this_sack_lowest_newack;
      uint32_t sav_cum_ack;
      uint16_t num_seg, num_dup;
      uint16_t wake_him = 0;
      unsigned int sack_length;
      uint32_t send_s = 0;
      long j;
      int accum_moved = 0;
      int will_exit_fast_recovery = 0;
      uint32_t a_rwnd, old_rwnd;
      int win_probe_recovery = 0;
      int win_probe_recovered = 0;
      struct sctp_nets *net = NULL;
      int nonce_sum_flag, ecn_seg_sums = 0;
      int done_once;
      uint8_t reneged_all = 0;
      uint8_t cmt_dac_flag;

      /*
       * we take any chance we can to service our queues since we cannot
       * get awoken when the socket is read from :<
       */
      /*
       * Now perform the actual SACK handling: 1) Verify that it is not an
       * old sack, if so discard. 2) If there is nothing left in the send
       * queue (cum-ack is equal to last acked) then you have a duplicate
       * too, update any rwnd change and verify no timers are running.
       * then return. 3) Process any new consequtive data i.e. cum-ack
       * moved process these first and note that it moved. 4) Process any
       * sack blocks. 5) Drop any acked from the queue. 6) Check for any
       * revoked blocks and mark. 7) Update the cwnd. 8) Nothing left,
       * sync up flightsizes and things, stop all timers and also check
       * for shutdown_pending state. If so then go ahead and send off the
       * shutdown. If in shutdown recv, send off the shutdown-ack and
       * start that timer, Ret. 9) Strike any non-acked things and do FR
       * procedure if needed being sure to set the FR flag. 10) Do pr-sctp
       * procedures. 11) Apply any FR penalties. 12) Assure we will SACK
       * if in shutdown_recv state.
       */
      SCTP_TCB_LOCK_ASSERT(stcb);
      sack = &ch->sack;
      /* CMT DAC algo */
      this_sack_lowest_newack = 0;
      j = 0;
      sack_length = (unsigned int)sack_len;
      /* ECN Nonce */
      SCTP_STAT_INCR(sctps_slowpath_sack);
      nonce_sum_flag = ch->ch.chunk_flags & SCTP_SACK_NONCE_SUM;
      cum_ack = last_tsn = ntohl(sack->cum_tsn_ack);
#ifdef SCTP_ASOCLOG_OF_TSNS
      stcb->asoc.cumack_log[stcb->asoc.cumack_log_at] = cum_ack;
      stcb->asoc.cumack_log_at++;
      if (stcb->asoc.cumack_log_at > SCTP_TSN_LOG_SIZE) {
            stcb->asoc.cumack_log_at = 0;
      }
#endif
      num_seg = ntohs(sack->num_gap_ack_blks);
      a_rwnd = rwnd;

      if (sctp_logging_level & SCTP_LOG_SACK_ARRIVALS_ENABLE) {
            sctp_misc_ints(SCTP_SACK_LOG_NORMAL, cum_ack,
                rwnd, stcb->asoc.last_acked_seq, stcb->asoc.peers_rwnd);
      }
      /* CMT DAC algo */
      cmt_dac_flag = ch->ch.chunk_flags & SCTP_SACK_CMT_DAC;
      num_dup = ntohs(sack->num_dup_tsns);

      old_rwnd = stcb->asoc.peers_rwnd;
      if (sctp_logging_level & SCTP_THRESHOLD_LOGGING) {
            sctp_misc_ints(SCTP_THRESHOLD_CLEAR,
                stcb->asoc.overall_error_count,
                0,
                SCTP_FROM_SCTP_INDATA,
                __LINE__);
      }
      stcb->asoc.overall_error_count = 0;
      asoc = &stcb->asoc;
      if (sctp_logging_level & SCTP_SACK_LOGGING_ENABLE) {
            sctp_log_sack(asoc->last_acked_seq,
                cum_ack,
                0,
                num_seg,
                num_dup,
                SCTP_LOG_NEW_SACK);
      }
      if ((num_dup) && (sctp_logging_level & (SCTP_FR_LOGGING_ENABLE | SCTP_EARLYFR_LOGGING_ENABLE))) {
            int off_to_dup, iii;
            uint32_t *dupdata, dblock;

            off_to_dup = (num_seg * sizeof(struct sctp_gap_ack_block)) + sizeof(struct sctp_sack_chunk);
            if ((off_to_dup + (num_dup * sizeof(uint32_t))) <= sack_length) {
                  dupdata = (uint32_t *) sctp_m_getptr(m, off_to_dup,
                      sizeof(uint32_t), (uint8_t *) & dblock);
                  off_to_dup += sizeof(uint32_t);
                  if (dupdata) {
                        for (iii = 0; iii < num_dup; iii++) {
                              sctp_log_fr(*dupdata, 0, 0, SCTP_FR_DUPED);
                              dupdata = (uint32_t *) sctp_m_getptr(m, off_to_dup,
                                  sizeof(uint32_t), (uint8_t *) & dblock);
                              if (dupdata == NULL)
                                    break;
                              off_to_dup += sizeof(uint32_t);
                        }
                  }
            } else {
                  SCTP_PRINTF("Size invalid offset to dups:%d number dups:%d sack_len:%d num gaps:%d\n",
                      off_to_dup, num_dup, sack_length, num_seg);
            }
      }
      if (sctp_strict_sacks) {
            /* reality check */
            if (!TAILQ_EMPTY(&asoc->sent_queue)) {
                  tp1 = TAILQ_LAST(&asoc->sent_queue,
                      sctpchunk_listhead);
                  send_s = tp1->rec.data.TSN_seq + 1;
            } else {
                  send_s = asoc->sending_seq;
            }
            if (cum_ack == send_s ||
                compare_with_wrap(cum_ack, send_s, MAX_TSN)) {
#ifndef INVARIANTS
                  struct mbuf *oper;

#endif
#ifdef INVARIANTS
      hopeless_peer:
                  panic("Impossible sack 1");
#else


                  /*
                   * no way, we have not even sent this TSN out yet.
                   * Peer is hopelessly messed up with us.
                   */
      hopeless_peer:
                  *abort_now = 1;
                  /* XXX */
                  oper = sctp_get_mbuf_for_msg((sizeof(struct sctp_paramhdr) + sizeof(uint32_t)),
                      0, M_DONTWAIT, 1, MT_DATA);
                  if (oper) {
                        struct sctp_paramhdr *ph;
                        uint32_t *ippp;

                        SCTP_BUF_LEN(oper) = sizeof(struct sctp_paramhdr) +
                            sizeof(uint32_t);
                        ph = mtod(oper, struct sctp_paramhdr *);
                        ph->param_type = htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                        ph->param_length = htons(SCTP_BUF_LEN(oper));
                        ippp = (uint32_t *) (ph + 1);
                        *ippp = htonl(SCTP_FROM_SCTP_INDATA + SCTP_LOC_25);
                  }
                  stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_25;
                  sctp_abort_an_association(stcb->sctp_ep, stcb, SCTP_PEER_FAULTY, oper, SCTP_SO_NOT_LOCKED);
                  return;
#endif
            }
      }
      /**********************/
      /* 1) check the range */
      /**********************/
      if (compare_with_wrap(asoc->last_acked_seq, last_tsn, MAX_TSN)) {
            /* acking something behind */
            return;
      }
      sav_cum_ack = asoc->last_acked_seq;

      /* update the Rwnd of the peer */
      if (TAILQ_EMPTY(&asoc->sent_queue) &&
          TAILQ_EMPTY(&asoc->send_queue) &&
          (asoc->stream_queue_cnt == 0)
          ) {
            /* nothing left on send/sent and strmq */
            if (sctp_logging_level & SCTP_LOG_RWND_ENABLE) {
                  sctp_log_rwnd_set(SCTP_SET_PEER_RWND_VIA_SACK,
                      asoc->peers_rwnd, 0, 0, a_rwnd);
            }
            asoc->peers_rwnd = a_rwnd;
            if (asoc->sent_queue_retran_cnt) {
                  asoc->sent_queue_retran_cnt = 0;
            }
            if (asoc->peers_rwnd < stcb->sctp_ep->sctp_ep.sctp_sws_sender) {
                  /* SWS sender side engages */
                  asoc->peers_rwnd = 0;
            }
            /* stop any timers */
            TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                  sctp_timer_stop(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep,
                      stcb, net, SCTP_FROM_SCTP_INDATA + SCTP_LOC_26);
                  if (sctp_early_fr) {
                        if (SCTP_OS_TIMER_PENDING(&net->fr_timer.timer)) {
                              SCTP_STAT_INCR(sctps_earlyfrstpidsck1);
                              sctp_timer_stop(SCTP_TIMER_TYPE_EARLYFR, stcb->sctp_ep, stcb, net,
                                  SCTP_FROM_SCTP_INDATA + SCTP_LOC_26);
                        }
                  }
                  net->partial_bytes_acked = 0;
                  net->flight_size = 0;
            }
            asoc->total_flight = 0;
            asoc->total_flight_count = 0;
            return;
      }
      /*
       * We init netAckSz and netAckSz2 to 0. These are used to track 2
       * things. The total byte count acked is tracked in netAckSz AND
       * netAck2 is used to track the total bytes acked that are un-
       * amibguious and were never retransmitted. We track these on a per
       * destination address basis.
       */
      TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
            net->prev_cwnd = net->cwnd;
            net->net_ack = 0;
            net->net_ack2 = 0;

            /*
             * CMT: Reset CUC and Fast recovery algo variables before
             * SACK processing
             */
            net->new_pseudo_cumack = 0;
            net->will_exit_fast_recovery = 0;
      }
      /* process the new consecutive TSN first */
      tp1 = TAILQ_FIRST(&asoc->sent_queue);
      while (tp1) {
            if (compare_with_wrap(last_tsn, tp1->rec.data.TSN_seq,
                MAX_TSN) ||
                last_tsn == tp1->rec.data.TSN_seq) {
                  if (tp1->sent != SCTP_DATAGRAM_UNSENT) {
                        /*
                         * ECN Nonce: Add the nonce to the sender's
                         * nonce sum
                         */
                        asoc->nonce_sum_expect_base += tp1->rec.data.ect_nonce;
                        accum_moved = 1;
                        if (tp1->sent < SCTP_DATAGRAM_ACKED) {
                              /*
                               * If it is less than ACKED, it is
                               * now no-longer in flight. Higher
                               * values may occur during marking
                               */
                              if ((tp1->whoTo->dest_state &
                                  SCTP_ADDR_UNCONFIRMED) &&
                                  (tp1->snd_count < 2)) {
                                    /*
                                     * If there was no retran
                                     * and the address is
                                     * un-confirmed and we sent
                                     * there and are now
                                     * sacked.. its confirmed,
                                     * mark it so.
                                     */
                                    tp1->whoTo->dest_state &=
                                        ~SCTP_ADDR_UNCONFIRMED;
                              }
                              if (tp1->sent < SCTP_DATAGRAM_RESEND) {
                                    if (sctp_logging_level & SCTP_FLIGHT_LOGGING_ENABLE) {
                                          sctp_misc_ints(SCTP_FLIGHT_LOG_DOWN_CA,
                                              tp1->whoTo->flight_size,
                                              tp1->book_size,
                                              (uintptr_t) tp1->whoTo,
                                              tp1->rec.data.TSN_seq);
                                    }
                                    sctp_flight_size_decrease(tp1);
                                    sctp_total_flight_decrease(stcb, tp1);
                              }
                              tp1->whoTo->net_ack += tp1->send_size;

                              /* CMT SFR and DAC algos */
                              this_sack_lowest_newack = tp1->rec.data.TSN_seq;
                              tp1->whoTo->saw_newack = 1;

                              if (tp1->snd_count < 2) {
                                    /*
                                     * True non-retransmited
                                     * chunk
                                     */
                                    tp1->whoTo->net_ack2 +=
                                        tp1->send_size;

                                    /* update RTO too? */
                                    if (tp1->do_rtt) {
                                          tp1->whoTo->RTO =
                                              sctp_calculate_rto(stcb,
                                              asoc, tp1->whoTo,
                                              &tp1->sent_rcv_time,
                                              sctp_align_safe_nocopy);
                                          tp1->do_rtt = 0;
                                    }
                              }
                              /*
                               * CMT: CUCv2 algorithm. From the
                               * cumack'd TSNs, for each TSN being
                               * acked for the first time, set the
                               * following variables for the
                               * corresp destination.
                               * new_pseudo_cumack will trigger a
                               * cwnd update.
                               * find_(rtx_)pseudo_cumack will
                               * trigger search for the next
                               * expected (rtx-)pseudo-cumack.
                               */
                              tp1->whoTo->new_pseudo_cumack = 1;
                              tp1->whoTo->find_pseudo_cumack = 1;
                              tp1->whoTo->find_rtx_pseudo_cumack = 1;


                              if (sctp_logging_level & SCTP_SACK_LOGGING_ENABLE) {
                                    sctp_log_sack(asoc->last_acked_seq,
                                        cum_ack,
                                        tp1->rec.data.TSN_seq,
                                        0,
                                        0,
                                        SCTP_LOG_TSN_ACKED);
                              }
                              if (sctp_logging_level & SCTP_CWND_LOGGING_ENABLE) {
                                    sctp_log_cwnd(stcb, tp1->whoTo, tp1->rec.data.TSN_seq, SCTP_CWND_LOG_FROM_SACK);
                              }
                        }
                        if (tp1->sent == SCTP_DATAGRAM_RESEND) {
                              sctp_ucount_decr(asoc->sent_queue_retran_cnt);
#ifdef SCTP_AUDITING_ENABLED
                              sctp_audit_log(0xB3,
                                  (asoc->sent_queue_retran_cnt & 0x000000ff));
#endif
                        }
                        if (tp1->rec.data.chunk_was_revoked) {
                              /* deflate the cwnd */
                              tp1->whoTo->cwnd -= tp1->book_size;
                              tp1->rec.data.chunk_was_revoked = 0;
                        }
                        tp1->sent = SCTP_DATAGRAM_ACKED;
                  }
            } else {
                  break;
            }
            tp1 = TAILQ_NEXT(tp1, sctp_next);
      }
      biggest_tsn_newly_acked = biggest_tsn_acked = last_tsn;
      /* always set this up to cum-ack */
      asoc->this_sack_highest_gap = last_tsn;

      /* Move offset up to point to gaps/dups */
      offset += sizeof(struct sctp_sack_chunk);
      if (((num_seg * (sizeof(struct sctp_gap_ack_block))) + sizeof(struct sctp_sack_chunk)) > sack_length) {

            /* skip corrupt segments */
            goto skip_segments;
      }
      if (num_seg > 0) {

            /*
             * CMT: SFR algo (and HTNA) - this_sack_highest_newack has
             * to be greater than the cumack. Also reset saw_newack to 0
             * for all dests.
             */
            TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                  net->saw_newack = 0;
                  net->this_sack_highest_newack = last_tsn;
            }

            /*
             * thisSackHighestGap will increase while handling NEW
             * segments this_sack_highest_newack will increase while
             * handling NEWLY ACKED chunks. this_sack_lowest_newack is
             * used for CMT DAC algo. saw_newack will also change.
             */
            sctp_handle_segments(m, &offset, stcb, asoc, ch, last_tsn,
                &biggest_tsn_acked, &biggest_tsn_newly_acked, &this_sack_lowest_newack,
                num_seg, &ecn_seg_sums);

            if (sctp_strict_sacks) {
                  /*
                   * validate the biggest_tsn_acked in the gap acks if
                   * strict adherence is wanted.
                   */
                  if ((biggest_tsn_acked == send_s) ||
                      (compare_with_wrap(biggest_tsn_acked, send_s, MAX_TSN))) {
                        /*
                         * peer is either confused or we are under
                         * attack. We must abort.
                         */
                        goto hopeless_peer;
                  }
            }
      }
skip_segments:
      /*******************************************/
      /* cancel ALL T3-send timer if accum moved */
      /*******************************************/
      if (sctp_cmt_on_off) {
            TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                  if (net->new_pseudo_cumack)
                        sctp_timer_stop(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep,
                            stcb, net,
                            SCTP_FROM_SCTP_INDATA + SCTP_LOC_27);

            }
      } else {
            if (accum_moved) {
                  TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                        sctp_timer_stop(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep,
                            stcb, net, SCTP_FROM_SCTP_INDATA + SCTP_LOC_28);
                  }
            }
      }
      /********************************************/
      /* drop the acked chunks from the sendqueue */
      /********************************************/
      asoc->last_acked_seq = cum_ack;

      tp1 = TAILQ_FIRST(&asoc->sent_queue);
      if (tp1 == NULL)
            goto done_with_it;
      do {
            if (compare_with_wrap(tp1->rec.data.TSN_seq, cum_ack,
                MAX_TSN)) {
                  break;
            }
            if (tp1->sent == SCTP_DATAGRAM_UNSENT) {
                  /* no more sent on list */
                  printf("Warning, tp1->sent == %d and its now acked?\n",
                      tp1->sent);
            }
            tp2 = TAILQ_NEXT(tp1, sctp_next);
            TAILQ_REMOVE(&asoc->sent_queue, tp1, sctp_next);
            if (tp1->pr_sctp_on) {
                  if (asoc->pr_sctp_cnt != 0)
                        asoc->pr_sctp_cnt--;
            }
            if ((TAILQ_FIRST(&asoc->sent_queue) == NULL) &&
                (asoc->total_flight > 0)) {
#ifdef INVARIANTS
                  panic("Warning flight size is postive and should be 0");
#else
                  SCTP_PRINTF("Warning flight size incorrect should be 0 is %d\n",
                      asoc->total_flight);
#endif
                  asoc->total_flight = 0;
            }
            if (tp1->data) {
                  /* sa_ignore NO_NULL_CHK */
                  sctp_free_bufspace(stcb, asoc, tp1, 1);
                  sctp_m_freem(tp1->data);
                  if (PR_SCTP_BUF_ENABLED(tp1->flags)) {
                        asoc->sent_queue_cnt_removeable--;
                  }
            }
            if (sctp_logging_level & SCTP_SACK_LOGGING_ENABLE) {
                  sctp_log_sack(asoc->last_acked_seq,
                      cum_ack,
                      tp1->rec.data.TSN_seq,
                      0,
                      0,
                      SCTP_LOG_FREE_SENT);
            }
            tp1->data = NULL;
            asoc->sent_queue_cnt--;
            sctp_free_a_chunk(stcb, tp1);
            wake_him++;
            tp1 = tp2;
      } while (tp1 != NULL);

done_with_it:
      /* sa_ignore NO_NULL_CHK */
      if ((wake_him) && (stcb->sctp_socket)) {
#if defined (__APPLE__) || defined(SCTP_SO_LOCK_TESTING)
            struct socket *so;

#endif
            SOCKBUF_LOCK(&stcb->sctp_socket->so_snd);
            if (sctp_logging_level & SCTP_WAKE_LOGGING_ENABLE) {
                  sctp_wakeup_log(stcb, cum_ack, wake_him, SCTP_WAKESND_FROM_SACK);
            }
#if defined (__APPLE__) || defined(SCTP_SO_LOCK_TESTING)
            so = SCTP_INP_SO(stcb->sctp_ep);
            atomic_add_int(&stcb->asoc.refcnt, 1);
            SCTP_TCB_UNLOCK(stcb);
            SCTP_SOCKET_LOCK(so, 1);
            SCTP_TCB_LOCK(stcb);
            atomic_subtract_int(&stcb->asoc.refcnt, 1);
            if (stcb->asoc.state & SCTP_STATE_CLOSED_SOCKET) {
                  /* assoc was freed while we were unlocked */
                  SCTP_SOCKET_UNLOCK(so, 1);
                  return;
            }
#endif
            sctp_sowwakeup_locked(stcb->sctp_ep, stcb->sctp_socket);
#if defined (__APPLE__) || defined(SCTP_SO_LOCK_TESTING)
            SCTP_SOCKET_UNLOCK(so, 1);
#endif
      } else {
            if (sctp_logging_level & SCTP_WAKE_LOGGING_ENABLE) {
                  sctp_wakeup_log(stcb, cum_ack, wake_him, SCTP_NOWAKE_FROM_SACK);
            }
      }

      if (asoc->fast_retran_loss_recovery && accum_moved) {
            if (compare_with_wrap(asoc->last_acked_seq,
                asoc->fast_recovery_tsn, MAX_TSN) ||
                asoc->last_acked_seq == asoc->fast_recovery_tsn) {
                  /* Setup so we will exit RFC2582 fast recovery */
                  will_exit_fast_recovery = 1;
            }
      }
      /*
       * Check for revoked fragments:
       * 
       * if Previous sack - Had no frags then we can't have any revoked if
       * Previous sack - Had frag's then - If we now have frags aka
       * num_seg > 0 call sctp_check_for_revoked() to tell if peer revoked
       * some of them. else - The peer revoked all ACKED fragments, since
       * we had some before and now we have NONE.
       */

      if (num_seg)
            sctp_check_for_revoked(stcb, asoc, cum_ack, biggest_tsn_acked);
      else if (asoc->saw_sack_with_frags) {
            int cnt_revoked = 0;

            tp1 = TAILQ_FIRST(&asoc->sent_queue);
            if (tp1 != NULL) {
                  /* Peer revoked all dg's marked or acked */
                  TAILQ_FOREACH(tp1, &asoc->sent_queue, sctp_next) {
                        if ((tp1->sent > SCTP_DATAGRAM_RESEND) &&
                            (tp1->sent < SCTP_FORWARD_TSN_SKIP)) {
                              tp1->sent = SCTP_DATAGRAM_SENT;
                              if (sctp_logging_level & SCTP_FLIGHT_LOGGING_ENABLE) {
                                    sctp_misc_ints(SCTP_FLIGHT_LOG_UP_REVOKE,
                                        tp1->whoTo->flight_size,
                                        tp1->book_size,
                                        (uintptr_t) tp1->whoTo,
                                        tp1->rec.data.TSN_seq);
                              }
                              sctp_flight_size_increase(tp1);
                              sctp_total_flight_increase(stcb, tp1);
                              tp1->rec.data.chunk_was_revoked = 1;
                              /*
                               * To ensure that this increase in
                               * flightsize, which is artificial,
                               * does not throttle the sender, we
                               * also increase the cwnd
                               * artificially.
                               */
                              tp1->whoTo->cwnd += tp1->book_size;
                              cnt_revoked++;
                        }
                  }
                  if (cnt_revoked) {
                        reneged_all = 1;
                  }
            }
            asoc->saw_sack_with_frags = 0;
      }
      if (num_seg)
            asoc->saw_sack_with_frags = 1;
      else
            asoc->saw_sack_with_frags = 0;

      /* JRS - Use the congestion control given in the CC module */
      asoc->cc_functions.sctp_cwnd_update_after_sack(stcb, asoc, accum_moved, reneged_all, will_exit_fast_recovery);

      if (TAILQ_EMPTY(&asoc->sent_queue)) {
            /* nothing left in-flight */
            TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                  /* stop all timers */
                  if (sctp_early_fr) {
                        if (SCTP_OS_TIMER_PENDING(&net->fr_timer.timer)) {
                              SCTP_STAT_INCR(sctps_earlyfrstpidsck4);
                              sctp_timer_stop(SCTP_TIMER_TYPE_EARLYFR, stcb->sctp_ep, stcb, net,
                                  SCTP_FROM_SCTP_INDATA + SCTP_LOC_29);
                        }
                  }
                  sctp_timer_stop(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep,
                      stcb, net, SCTP_FROM_SCTP_INDATA + SCTP_LOC_30);
                  net->flight_size = 0;
                  net->partial_bytes_acked = 0;
            }
            asoc->total_flight = 0;
            asoc->total_flight_count = 0;
      }
      /**********************************/
      /* Now what about shutdown issues */
      /**********************************/
      if (TAILQ_EMPTY(&asoc->send_queue) && TAILQ_EMPTY(&asoc->sent_queue)) {
            /* nothing left on sendqueue.. consider done */
            if (sctp_logging_level & SCTP_LOG_RWND_ENABLE) {
                  sctp_log_rwnd_set(SCTP_SET_PEER_RWND_VIA_SACK,
                      asoc->peers_rwnd, 0, 0, a_rwnd);
            }
            asoc->peers_rwnd = a_rwnd;
            if (asoc->peers_rwnd < stcb->sctp_ep->sctp_ep.sctp_sws_sender) {
                  /* SWS sender side engages */
                  asoc->peers_rwnd = 0;
            }
            /* clean up */
            if ((asoc->stream_queue_cnt == 1) &&
                ((asoc->state & SCTP_STATE_SHUTDOWN_PENDING) ||
                (asoc->state & SCTP_STATE_SHUTDOWN_RECEIVED)) &&
                (asoc->locked_on_sending)
                ) {
                  struct sctp_stream_queue_pending *sp;

                  /*
                   * I may be in a state where we got all across.. but
                   * cannot write more due to a shutdown... we abort
                   * since the user did not indicate EOR in this case.
                   */
                  sp = TAILQ_LAST(&((asoc->locked_on_sending)->outqueue),
                      sctp_streamhead);
                  if ((sp) && (sp->length == 0)) {
                        asoc->locked_on_sending = NULL;
                        if (sp->msg_is_complete) {
                              asoc->stream_queue_cnt--;
                        } else {
                              asoc->state |= SCTP_STATE_PARTIAL_MSG_LEFT;
                              asoc->stream_queue_cnt--;
                        }
                  }
            }
            if ((asoc->state & SCTP_STATE_SHUTDOWN_PENDING) &&
                (asoc->stream_queue_cnt == 0)) {
                  if (asoc->state & SCTP_STATE_PARTIAL_MSG_LEFT) {
                        /* Need to abort here */
                        struct mbuf *oper;

            abort_out_now:
                        *abort_now = 1;
                        /* XXX */
                        oper = sctp_get_mbuf_for_msg((sizeof(struct sctp_paramhdr) + sizeof(uint32_t)),
                            0, M_DONTWAIT, 1, MT_DATA);
                        if (oper) {
                              struct sctp_paramhdr *ph;
                              uint32_t *ippp;

                              SCTP_BUF_LEN(oper) = sizeof(struct sctp_paramhdr) +
                                  sizeof(uint32_t);
                              ph = mtod(oper, struct sctp_paramhdr *);
                              ph->param_type = htons(SCTP_CAUSE_USER_INITIATED_ABT);
                              ph->param_length = htons(SCTP_BUF_LEN(oper));
                              ippp = (uint32_t *) (ph + 1);
                              *ippp = htonl(SCTP_FROM_SCTP_INDATA + SCTP_LOC_31);
                        }
                        stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_31;
                        sctp_abort_an_association(stcb->sctp_ep, stcb, SCTP_RESPONSE_TO_USER_REQ, oper, SCTP_SO_NOT_LOCKED);
                        return;
                  } else {
                        if ((SCTP_GET_STATE(asoc) == SCTP_STATE_OPEN) ||
                            (SCTP_GET_STATE(asoc) == SCTP_STATE_SHUTDOWN_RECEIVED)) {
                              SCTP_STAT_DECR_GAUGE32(sctps_currestab);
                        }
                        SCTP_SET_STATE(asoc, SCTP_STATE_SHUTDOWN_SENT);
                        SCTP_CLEAR_SUBSTATE(asoc, SCTP_STATE_SHUTDOWN_PENDING);
                        sctp_stop_timers_for_shutdown(stcb);
                        sctp_send_shutdown(stcb,
                            stcb->asoc.primary_destination);
                        sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWN,
                            stcb->sctp_ep, stcb, asoc->primary_destination);
                        sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWNGUARD,
                            stcb->sctp_ep, stcb, asoc->primary_destination);
                  }
                  return;
            } else if ((SCTP_GET_STATE(asoc) == SCTP_STATE_SHUTDOWN_RECEIVED) &&
                (asoc->stream_queue_cnt == 0)) {
                  if (asoc->state & SCTP_STATE_PARTIAL_MSG_LEFT) {
                        goto abort_out_now;
                  }
                  SCTP_STAT_DECR_GAUGE32(sctps_currestab);
                  SCTP_SET_STATE(asoc, SCTP_STATE_SHUTDOWN_ACK_SENT);
                  SCTP_CLEAR_SUBSTATE(asoc, SCTP_STATE_SHUTDOWN_PENDING);
                  sctp_send_shutdown_ack(stcb,
                      stcb->asoc.primary_destination);

                  sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWNACK,
                      stcb->sctp_ep, stcb, asoc->primary_destination);
                  return;
            }
      }
      /*
       * Now here we are going to recycle net_ack for a different use...
       * HEADS UP.
       */
      TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
            net->net_ack = 0;
      }

      /*
       * CMT DAC algorithm: If SACK DAC flag was 0, then no extra marking
       * to be done. Setting this_sack_lowest_newack to the cum_ack will
       * automatically ensure that.
       */
      if (sctp_cmt_on_off && sctp_cmt_use_dac && (cmt_dac_flag == 0)) {
            this_sack_lowest_newack = cum_ack;
      }
      if (num_seg > 0) {
            sctp_strike_gap_ack_chunks(stcb, asoc, biggest_tsn_acked,
                biggest_tsn_newly_acked, this_sack_lowest_newack, accum_moved);
      }
      /*********************************************/
      /* Here we perform PR-SCTP procedures        */
      /* (section 4.2)                             */
      /*********************************************/
      /* C1. update advancedPeerAckPoint */
      if (compare_with_wrap(cum_ack, asoc->advanced_peer_ack_point, MAX_TSN)) {
            asoc->advanced_peer_ack_point = cum_ack;
      }
      /* C2. try to further move advancedPeerAckPoint ahead */
      if ((asoc->peer_supports_prsctp) && (asoc->pr_sctp_cnt > 0)) {
            struct sctp_tmit_chunk *lchk;

            lchk = sctp_try_advance_peer_ack_point(stcb, asoc);
            /* C3. See if we need to send a Fwd-TSN */
            if (compare_with_wrap(asoc->advanced_peer_ack_point, cum_ack,
                MAX_TSN)) {
                  /*
                   * ISSUE with ECN, see FWD-TSN processing for notes
                   * on issues that will occur when the ECN NONCE
                   * stuff is put into SCTP for cross checking.
                   */
                  send_forward_tsn(stcb, asoc);

                  /*
                   * ECN Nonce: Disable Nonce Sum check when FWD TSN
                   * is sent and store resync tsn
                   */
                  asoc->nonce_sum_check = 0;
                  asoc->nonce_resync_tsn = asoc->advanced_peer_ack_point;
                  if (lchk) {
                        /* Assure a timer is up */
                        sctp_timer_start(SCTP_TIMER_TYPE_SEND,
                            stcb->sctp_ep, stcb, lchk->whoTo);
                  }
            }
      }
      /* JRS - Use the congestion control given in the CC module */
      asoc->cc_functions.sctp_cwnd_update_after_fr(stcb, asoc);

      /******************************************************************
       *  Here we do the stuff with ECN Nonce checking.
       *  We basically check to see if the nonce sum flag was incorrect
       *  or if resynchronization needs to be done. Also if we catch a
       *  misbehaving receiver we give him the kick.
       ******************************************************************/

      if (asoc->ecn_nonce_allowed) {
            if (asoc->nonce_sum_check) {
                  if (nonce_sum_flag != ((asoc->nonce_sum_expect_base + ecn_seg_sums) & SCTP_SACK_NONCE_SUM)) {
                        if (asoc->nonce_wait_for_ecne == 0) {
                              struct sctp_tmit_chunk *lchk;

                              lchk = TAILQ_FIRST(&asoc->send_queue);
                              asoc->nonce_wait_for_ecne = 1;
                              if (lchk) {
                                    asoc->nonce_wait_tsn = lchk->rec.data.TSN_seq;
                              } else {
                                    asoc->nonce_wait_tsn = asoc->sending_seq;
                              }
                        } else {
                              if (compare_with_wrap(asoc->last_acked_seq, asoc->nonce_wait_tsn, MAX_TSN) ||
                                  (asoc->last_acked_seq == asoc->nonce_wait_tsn)) {
                                    /*
                                     * Misbehaving peer. We need
                                     * to react to this guy
                                     */
                                    asoc->ecn_allowed = 0;
                                    asoc->ecn_nonce_allowed = 0;
                              }
                        }
                  }
            } else {
                  /* See if Resynchronization Possible */
                  if (compare_with_wrap(asoc->last_acked_seq, asoc->nonce_resync_tsn, MAX_TSN)) {
                        asoc->nonce_sum_check = 1;
                        /*
                         * now we must calculate what the base is.
                         * We do this based on two things, we know
                         * the total's for all the segments
                         * gap-acked in the SACK, its stored in
                         * ecn_seg_sums. We also know the SACK's
                         * nonce sum, its in nonce_sum_flag. So we
                         * can build a truth table to back-calculate
                         * the new value of
                         * asoc->nonce_sum_expect_base:
                         * 
                         * SACK-flag-Value         Seg-Sums Base 0 0 0
                         * 1                    0 1 0 1 1 1
                         * 1 0
                         */
                        asoc->nonce_sum_expect_base = (ecn_seg_sums ^ nonce_sum_flag) & SCTP_SACK_NONCE_SUM;
                  }
            }
      }
      /* Now are we exiting loss recovery ? */
      if (will_exit_fast_recovery) {
            /* Ok, we must exit fast recovery */
            asoc->fast_retran_loss_recovery = 0;
      }
      if ((asoc->sat_t3_loss_recovery) &&
          ((compare_with_wrap(asoc->last_acked_seq, asoc->sat_t3_recovery_tsn,
          MAX_TSN) ||
          (asoc->last_acked_seq == asoc->sat_t3_recovery_tsn)))) {
            /* end satellite t3 loss recovery */
            asoc->sat_t3_loss_recovery = 0;
      }
      /*
       * CMT Fast recovery
       */
      TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
            if (net->will_exit_fast_recovery) {
                  /* Ok, we must exit fast recovery */
                  net->fast_retran_loss_recovery = 0;
            }
      }

      /* Adjust and set the new rwnd value */
      if (sctp_logging_level & SCTP_LOG_RWND_ENABLE) {
            sctp_log_rwnd_set(SCTP_SET_PEER_RWND_VIA_SACK,
                asoc->peers_rwnd, asoc->total_flight, (asoc->sent_queue_cnt * sctp_peer_chunk_oh), a_rwnd);
      }
      asoc->peers_rwnd = sctp_sbspace_sub(a_rwnd,
          (uint32_t) (asoc->total_flight + (asoc->sent_queue_cnt * sctp_peer_chunk_oh)));
      if (asoc->peers_rwnd < stcb->sctp_ep->sctp_ep.sctp_sws_sender) {
            /* SWS sender side engages */
            asoc->peers_rwnd = 0;
      }
      if (asoc->peers_rwnd > old_rwnd) {
            win_probe_recovery = 1;
      }
      /*
       * Now we must setup so we have a timer up for anyone with
       * outstanding data.
       */
      done_once = 0;
again:
      j = 0;
      TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
            if (win_probe_recovery && (net->window_probe)) {
                  net->window_probe = 0;
                  win_probe_recovered = 1;
                  /*-
                   * Find first chunk that was used with
                   * window probe and clear the event. Put
                   * it back into the send queue as if has
                   * not been sent.
                   */
                  TAILQ_FOREACH(tp1, &asoc->sent_queue, sctp_next) {
                        if (tp1->window_probe) {
                              sctp_window_probe_recovery(stcb, asoc, net, tp1);
                              break;
                        }
                  }
            }
            if (net->flight_size) {
                  j++;
                  sctp_timer_start(SCTP_TIMER_TYPE_SEND,
                      stcb->sctp_ep, stcb, net);
            } else {
                  if (SCTP_OS_TIMER_PENDING(&net->rxt_timer.timer)) {
                        sctp_timer_stop(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep,
                            stcb, net,
                            SCTP_FROM_SCTP_INDATA + SCTP_LOC_22);
                  }
                  if (sctp_early_fr) {
                        if (SCTP_OS_TIMER_PENDING(&net->fr_timer.timer)) {
                              SCTP_STAT_INCR(sctps_earlyfrstpidsck4);
                              sctp_timer_stop(SCTP_TIMER_TYPE_EARLYFR, stcb->sctp_ep, stcb, net,
                                  SCTP_FROM_SCTP_INDATA + SCTP_LOC_23);
                        }
                  }
            }
      }
      if ((j == 0) &&
          (!TAILQ_EMPTY(&asoc->sent_queue)) &&
          (asoc->sent_queue_retran_cnt == 0) &&
          (win_probe_recovered == 0) &&
          (done_once == 0)) {
            /* huh, this should not happen */
            sctp_fs_audit(asoc);
            TAILQ_FOREACH(net, &asoc->nets, sctp_next) {
                  net->flight_size = 0;
            }
            asoc->total_flight = 0;
            asoc->total_flight_count = 0;
            asoc->sent_queue_retran_cnt = 0;
            TAILQ_FOREACH(tp1, &asoc->sent_queue, sctp_next) {
                  if (tp1->sent < SCTP_DATAGRAM_RESEND) {
                        sctp_flight_size_increase(tp1);
                        sctp_total_flight_increase(stcb, tp1);
                  } else if (tp1->sent == SCTP_DATAGRAM_RESEND) {
                        asoc->sent_queue_retran_cnt++;
                  }
            }
            done_once = 1;
            goto again;
      }
      if (sctp_logging_level & SCTP_SACK_RWND_LOGGING_ENABLE) {
            sctp_misc_ints(SCTP_SACK_RWND_UPDATE,
                a_rwnd,
                stcb->asoc.peers_rwnd,
                stcb->asoc.total_flight,
                stcb->asoc.total_output_queue_size);
      }
}

void
sctp_update_acked(struct sctp_tcb *stcb, struct sctp_shutdown_chunk *cp,
    struct sctp_nets *netp, int *abort_flag)
{
      /* Copy cum-ack */
      uint32_t cum_ack, a_rwnd;

      cum_ack = ntohl(cp->cumulative_tsn_ack);
      /* Arrange so a_rwnd does NOT change */
      a_rwnd = stcb->asoc.peers_rwnd + stcb->asoc.total_flight;

      /* Now call the express sack handling */
      sctp_express_handle_sack(stcb, cum_ack, a_rwnd, 0, abort_flag);
}

static void
sctp_kick_prsctp_reorder_queue(struct sctp_tcb *stcb,
    struct sctp_stream_in *strmin)
{
      struct sctp_queued_to_read *ctl, *nctl;
      struct sctp_association *asoc;
      int tt;

      asoc = &stcb->asoc;
      tt = strmin->last_sequence_delivered;
      /*
       * First deliver anything prior to and including the stream no that
       * came in
       */
      ctl = TAILQ_FIRST(&strmin->inqueue);
      while (ctl) {
            nctl = TAILQ_NEXT(ctl, next);
            if (compare_with_wrap(tt, ctl->sinfo_ssn, MAX_SEQ) ||
                (tt == ctl->sinfo_ssn)) {
                  /* this is deliverable now */
                  TAILQ_REMOVE(&strmin->inqueue, ctl, next);
                  /* subtract pending on streams */
                  asoc->size_on_all_streams -= ctl->length;
                  sctp_ucount_decr(asoc->cnt_on_all_streams);
                  /* deliver it to at least the delivery-q */
                  if (stcb->sctp_socket) {
                        sctp_add_to_readq(stcb->sctp_ep, stcb,
                            ctl,
                            &stcb->sctp_socket->so_rcv, 1, SCTP_SO_NOT_LOCKED);
                  }
            } else {
                  /* no more delivery now. */
                  break;
            }
            ctl = nctl;
      }
      /*
       * now we must deliver things in queue the normal way  if any are
       * now ready.
       */
      tt = strmin->last_sequence_delivered + 1;
      ctl = TAILQ_FIRST(&strmin->inqueue);
      while (ctl) {
            nctl = TAILQ_NEXT(ctl, next);
            if (tt == ctl->sinfo_ssn) {
                  /* this is deliverable now */
                  TAILQ_REMOVE(&strmin->inqueue, ctl, next);
                  /* subtract pending on streams */
                  asoc->size_on_all_streams -= ctl->length;
                  sctp_ucount_decr(asoc->cnt_on_all_streams);
                  /* deliver it to at least the delivery-q */
                  strmin->last_sequence_delivered = ctl->sinfo_ssn;
                  if (stcb->sctp_socket) {
                        sctp_add_to_readq(stcb->sctp_ep, stcb,
                            ctl,
                            &stcb->sctp_socket->so_rcv, 1, SCTP_SO_NOT_LOCKED);
                  }
                  tt = strmin->last_sequence_delivered + 1;
            } else {
                  break;
            }
            ctl = nctl;
      }
}

void
sctp_handle_forward_tsn(struct sctp_tcb *stcb,
    struct sctp_forward_tsn_chunk *fwd, int *abort_flag, struct mbuf *m, int offset)
{
      /*
       * ISSUES that MUST be fixed for ECN! When we are the sender of the
       * forward TSN, when the SACK comes back that acknowledges the
       * FWD-TSN we must reset the NONCE sum to match correctly. This will
       * get quite tricky since we may have sent more data interveneing
       * and must carefully account for what the SACK says on the nonce
       * and any gaps that are reported. This work will NOT be done here,
       * but I note it here since it is really related to PR-SCTP and
       * FWD-TSN's
       */

      /* The pr-sctp fwd tsn */
      /*
       * here we will perform all the data receiver side steps for
       * processing FwdTSN, as required in by pr-sctp draft:
       * 
       * Assume we get FwdTSN(x):
       * 
       * 1) update local cumTSN to x 2) try to further advance cumTSN to x +
       * others we have 3) examine and update re-ordering queue on
       * pr-in-streams 4) clean up re-assembly queue 5) Send a sack to
       * report where we are.
       */
      struct sctp_association *asoc;
      uint32_t new_cum_tsn, gap;
      unsigned int i, cnt_gone, fwd_sz, cumack_set_flag, m_size;
      struct sctp_stream_in *strm;
      struct sctp_tmit_chunk *chk, *at;

      cumack_set_flag = 0;
      asoc = &stcb->asoc;
      cnt_gone = 0;
      if ((fwd_sz = ntohs(fwd->ch.chunk_length)) < sizeof(struct sctp_forward_tsn_chunk)) {
            SCTPDBG(SCTP_DEBUG_INDATA1,
                "Bad size too small/big fwd-tsn\n");
            return;
      }
      m_size = (stcb->asoc.mapping_array_size << 3);
      /*************************************************************/
      /* 1. Here we update local cumTSN and shift the bitmap array */
      /*************************************************************/
      new_cum_tsn = ntohl(fwd->new_cumulative_tsn);

      if (compare_with_wrap(asoc->cumulative_tsn, new_cum_tsn, MAX_TSN) ||
          asoc->cumulative_tsn == new_cum_tsn) {
            /* Already got there ... */
            return;
      }
      if (compare_with_wrap(new_cum_tsn, asoc->highest_tsn_inside_map,
          MAX_TSN)) {
            asoc->highest_tsn_inside_map = new_cum_tsn;
            if (sctp_logging_level & SCTP_MAP_LOGGING_ENABLE) {
                  sctp_log_map(0, 0, asoc->highest_tsn_inside_map, SCTP_MAP_SLIDE_RESULT);
            }
      }
      /*
       * now we know the new TSN is more advanced, let's find the actual
       * gap
       */
      if ((compare_with_wrap(new_cum_tsn, asoc->mapping_array_base_tsn,
          MAX_TSN)) ||
          (new_cum_tsn == asoc->mapping_array_base_tsn)) {
            gap = new_cum_tsn - asoc->mapping_array_base_tsn;
      } else {
            /* try to prevent underflow here */
            gap = new_cum_tsn + (MAX_TSN - asoc->mapping_array_base_tsn) + 1;
      }

      if (gap >= m_size) {
            if (sctp_logging_level & SCTP_MAP_LOGGING_ENABLE) {
                  sctp_log_map(0, 0, asoc->highest_tsn_inside_map, SCTP_MAP_SLIDE_RESULT);
            }
            if ((long)gap > sctp_sbspace(&stcb->asoc, &stcb->sctp_socket->so_rcv)) {
                  struct mbuf *oper;

                  /*
                   * out of range (of single byte chunks in the rwnd I
                   * give out). This must be an attacker.
                   */
                  *abort_flag = 1;
                  oper = sctp_get_mbuf_for_msg((sizeof(struct sctp_paramhdr) + 3 * sizeof(uint32_t)),
                      0, M_DONTWAIT, 1, MT_DATA);
                  if (oper) {
                        struct sctp_paramhdr *ph;
                        uint32_t *ippp;

                        SCTP_BUF_LEN(oper) = sizeof(struct sctp_paramhdr) +
                            (sizeof(uint32_t) * 3);
                        ph = mtod(oper, struct sctp_paramhdr *);
                        ph->param_type = htons(SCTP_CAUSE_PROTOCOL_VIOLATION);
                        ph->param_length = htons(SCTP_BUF_LEN(oper));
                        ippp = (uint32_t *) (ph + 1);
                        *ippp = htonl(SCTP_FROM_SCTP_INDATA + SCTP_LOC_33);
                        ippp++;
                        *ippp = asoc->highest_tsn_inside_map;
                        ippp++;
                        *ippp = new_cum_tsn;
                  }
                  stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INDATA + SCTP_LOC_33;
                  sctp_abort_an_association(stcb->sctp_ep, stcb,
                      SCTP_PEER_FAULTY, oper, SCTP_SO_NOT_LOCKED);
                  return;
            }
            SCTP_STAT_INCR(sctps_fwdtsn_map_over);
slide_out:
            memset(stcb->asoc.mapping_array, 0, stcb->asoc.mapping_array_size);
            cumack_set_flag = 1;
            asoc->mapping_array_base_tsn = new_cum_tsn + 1;
            asoc->cumulative_tsn = asoc->highest_tsn_inside_map = new_cum_tsn;

            if (sctp_logging_level & SCTP_MAP_LOGGING_ENABLE) {
                  sctp_log_map(0, 3, asoc->highest_tsn_inside_map, SCTP_MAP_SLIDE_RESULT);
            }
            asoc->last_echo_tsn = asoc->highest_tsn_inside_map;
      } else {
            SCTP_TCB_LOCK_ASSERT(stcb);
            if ((compare_with_wrap(((uint32_t) asoc->cumulative_tsn + gap), asoc->highest_tsn_inside_map, MAX_TSN)) ||
                (((uint32_t) asoc->cumulative_tsn + gap) == asoc->highest_tsn_inside_map)) {
                  goto slide_out;
            } else {
                  for (i = 0; i <= gap; i++) {
                        SCTP_SET_TSN_PRESENT(asoc->mapping_array, i);
                  }
            }
            /*
             * Now after marking all, slide thing forward but no sack
             * please.
             */
            sctp_sack_check(stcb, 0, 0, abort_flag);
            if (*abort_flag)
                  return;
      }

      /*************************************************************/
      /* 2. Clear up re-assembly queue                             */
      /*************************************************************/
      /*
       * First service it if pd-api is up, just in case we can progress it
       * forward
       */
      if (asoc->fragmented_delivery_inprogress) {
            sctp_service_reassembly(stcb, asoc);
      }
      if (!TAILQ_EMPTY(&asoc->reasmqueue)) {
            /* For each one on here see if we need to toss it */
            /*
             * For now large messages held on the reasmqueue that are
             * complete will be tossed too. We could in theory do more
             * work to spin through and stop after dumping one msg aka
             * seeing the start of a new msg at the head, and call the
             * delivery function... to see if it can be delivered... But
             * for now we just dump everything on the queue.
             */
            chk = TAILQ_FIRST(&asoc->reasmqueue);
            while (chk) {
                  at = TAILQ_NEXT(chk, sctp_next);
                  if (compare_with_wrap(asoc->cumulative_tsn,
                      chk->rec.data.TSN_seq, MAX_TSN) ||
                      asoc->cumulative_tsn == chk->rec.data.TSN_seq) {
                        /* It needs to be tossed */
                        TAILQ_REMOVE(&asoc->reasmqueue, chk, sctp_next);
                        if (compare_with_wrap(chk->rec.data.TSN_seq,
                            asoc->tsn_last_delivered, MAX_TSN)) {
                              asoc->tsn_last_delivered =
                                  chk->rec.data.TSN_seq;
                              asoc->str_of_pdapi =
                                  chk->rec.data.stream_number;
                              asoc->ssn_of_pdapi =
                                  chk->rec.data.stream_seq;
                              asoc->fragment_flags =
                                  chk->rec.data.rcv_flags;
                        }
                        asoc->size_on_reasm_queue -= chk->send_size;
                        sctp_ucount_decr(asoc->cnt_on_reasm_queue);
                        cnt_gone++;

                        /* Clear up any stream problem */
                        if ((chk->rec.data.rcv_flags & SCTP_DATA_UNORDERED) !=
                            SCTP_DATA_UNORDERED &&
                            (compare_with_wrap(chk->rec.data.stream_seq,
                            asoc->strmin[chk->rec.data.stream_number].last_sequence_delivered,
                            MAX_SEQ))) {
                              /*
                               * We must dump forward this streams
                               * sequence number if the chunk is
                               * not unordered that is being
                               * skipped. There is a chance that
                               * if the peer does not include the
                               * last fragment in its FWD-TSN we
                               * WILL have a problem here since
                               * you would have a partial chunk in
                               * queue that may not be
                               * deliverable. Also if a Partial
                               * delivery API as started the user
                               * may get a partial chunk. The next
                               * read returning a new chunk...
                               * really ugly but I see no way
                               * around it! Maybe a notify??
                               */
                              asoc->strmin[chk->rec.data.stream_number].last_sequence_delivered =
                                  chk->rec.data.stream_seq;
                        }
                        if (chk->data) {
                              sctp_m_freem(chk->data);
                              chk->data = NULL;
                        }
                        sctp_free_a_chunk(stcb, chk);
                  } else {
                        /*
                         * Ok we have gone beyond the end of the
                         * fwd-tsn's mark. Some checks...
                         */
                        if ((asoc->fragmented_delivery_inprogress) &&
                            (chk->rec.data.rcv_flags & SCTP_DATA_FIRST_FRAG)) {
                              uint32_t str_seq;

                              /*
                               * Special case PD-API is up and
                               * what we fwd-tsn' over includes
                               * one that had the LAST_FRAG. We no
                               * longer need to do the PD-API.
                               */
                              asoc->fragmented_delivery_inprogress = 0;

                              str_seq = (asoc->str_of_pdapi << 16) | asoc->ssn_of_pdapi;
                              sctp_ulp_notify(SCTP_NOTIFY_PARTIAL_DELVIERY_INDICATION,
                                  stcb, SCTP_PARTIAL_DELIVERY_ABORTED, (void *)&str_seq, SCTP_SO_NOT_LOCKED);

                        }
                        break;
                  }
                  chk = at;
            }
      }
      if (asoc->fragmented_delivery_inprogress) {
            /*
             * Ok we removed cnt_gone chunks in the PD-API queue that
             * were being delivered. So now we must turn off the flag.
             */
            uint32_t str_seq;

            str_seq = (asoc->str_of_pdapi << 16) | asoc->ssn_of_pdapi;
            sctp_ulp_notify(SCTP_NOTIFY_PARTIAL_DELVIERY_INDICATION,
                stcb, SCTP_PARTIAL_DELIVERY_ABORTED, (void *)&str_seq, SCTP_SO_NOT_LOCKED);
            asoc->fragmented_delivery_inprogress = 0;
      }
      /*************************************************************/
      /* 3. Update the PR-stream re-ordering queues                */
      /*************************************************************/
      fwd_sz -= sizeof(*fwd);
      if (m && fwd_sz) {
            /* New method. */
            unsigned int num_str;
            struct sctp_strseq *stseq, strseqbuf;

            offset += sizeof(*fwd);

            num_str = fwd_sz / sizeof(struct sctp_strseq);
            for (i = 0; i < num_str; i++) {
                  uint16_t st;

                  stseq = (struct sctp_strseq *)sctp_m_getptr(m, offset,
                      sizeof(struct sctp_strseq),
                      (uint8_t *) & strseqbuf);
                  offset += sizeof(struct sctp_strseq);
                  if (stseq == NULL) {
                        break;
                  }
                  /* Convert */
                  st = ntohs(stseq->stream);
                  stseq->stream = st;
                  st = ntohs(stseq->sequence);
                  stseq->sequence = st;
                  /* now process */
                  if (stseq->stream >= asoc->streamincnt) {
                        /* screwed up streams, stop!  */
                        break;
                  }
                  strm = &asoc->strmin[stseq->stream];
                  if (compare_with_wrap(stseq->sequence,
                      strm->last_sequence_delivered, MAX_SEQ)) {
                        /* Update the sequence number */
                        strm->last_sequence_delivered =
                            stseq->sequence;
                  }
                  /* now kick the stream the new way */
                  /* sa_ignore NO_NULL_CHK */
                  sctp_kick_prsctp_reorder_queue(stcb, strm);
            }
      }
      if (TAILQ_FIRST(&asoc->reasmqueue)) {
            /* now lets kick out and check for more fragmented delivery */
            /* sa_ignore NO_NULL_CHK */
            sctp_deliver_reasm_check(stcb, &stcb->asoc);
      }
}

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