/src/usrsctp/usrsctplib/netinet/sctp_input.c

Source
/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 2001-2008, by Cisco Systems, Inc. All rights reserved.
 * Copyright (c) 2008-2012, by Randall Stewart. All rights reserved.
 * Copyright (c) 2008-2012, by Michael Tuexen. 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.
 */

#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_auth.h>
#include <netinet/sctp_indata.h>
#include <netinet/sctp_asconf.h>
#include <netinet/sctp_bsd_addr.h>
#include <netinet/sctp_timer.h>
#include <netinet/sctp_crc32.h>
#if defined(__FreeBSD__) && !defined(__Userspace__)
#include <netinet/sctp_kdtrace.h>
#endif
#if defined(INET) || defined(INET6)
#if !defined(_WIN32)
#include <netinet/udp.h>
#endif
#endif
#if defined(__FreeBSD__) && !defined(__Userspace__)
#include <sys/smp.h>
#endif

static void
sctp_stop_all_cookie_timers(struct sctp_tcb *stcb)
{
  struct sctp_nets *net;

  /* This now not only stops all cookie timers
   * it also stops any INIT timers as well. This
   * will make sure that the timers are stopped in
   * all collision cases.
   */
  SCTP_TCB_LOCK_ASSERT(stcb);
  TAILQ_FOREACH(net, &stcb->asoc.nets, sctp_next) {
    if (net->rxt_timer.type == SCTP_TIMER_TYPE_COOKIE) {
      sctp_timer_stop(SCTP_TIMER_TYPE_COOKIE,
          stcb->sctp_ep,
          stcb,
          net, SCTP_FROM_SCTP_INPUT + SCTP_LOC_1);
    } else if (net->rxt_timer.type == SCTP_TIMER_TYPE_INIT) {
      sctp_timer_stop(SCTP_TIMER_TYPE_INIT,
          stcb->sctp_ep,
          stcb,
          net, SCTP_FROM_SCTP_INPUT + SCTP_LOC_2);
    }
  }
}

/* INIT handler */
static void
sctp_handle_init(struct mbuf *m, int iphlen, int offset,
                 struct sockaddr *src, struct sockaddr *dst, struct sctphdr *sh,
                 struct sctp_init_chunk *cp, struct sctp_inpcb *inp,
                 struct sctp_tcb *stcb, struct sctp_nets *net,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                 uint8_t mflowtype, uint32_t mflowid,
#endif
                 uint32_t vrf_id, uint16_t port)
{
  struct sctp_init *init;
  struct mbuf *op_err;

  SCTPDBG(SCTP_DEBUG_INPUT2, "sctp_handle_init: handling INIT tcb:%p\n",
    (void *)stcb);
  if (stcb == NULL) {
    SCTP_INP_RLOCK(inp);
  }
  /* Validate parameters */
  init = &cp->init;
  if (ntohl(init->initiate_tag) == 0) {
    goto outnow;
  }
  if ((ntohl(init->a_rwnd) < SCTP_MIN_RWND) ||
      (ntohs(init->num_inbound_streams) == 0) ||
      (ntohs(init->num_outbound_streams) == 0)) {
    /* protocol error... send abort */
    op_err = sctp_generate_cause(SCTP_CAUSE_INVALID_PARAM, "");
    sctp_send_abort(m, iphlen, src, dst, sh, init->initiate_tag, op_err,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                    mflowtype, mflowid, inp->fibnum,
#endif
                    vrf_id, port);
    goto outnow;
  }
  if (sctp_validate_init_auth_params(m, offset + sizeof(*cp),
             offset + ntohs(cp->ch.chunk_length))) {
    /* auth parameter(s) error... send abort */
    op_err = sctp_generate_cause(SCTP_BASE_SYSCTL(sctp_diag_info_code),
                                 "Problem with AUTH parameters");
    sctp_send_abort(m, iphlen, src, dst, sh, init->initiate_tag, op_err,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                    mflowtype, mflowid, inp->fibnum,
#endif
                    vrf_id, port);
    goto outnow;
  }
  /* We are only accepting if we have a listening socket.*/
  if ((stcb == NULL) &&
      ((inp->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE) ||
       (inp->sctp_flags & SCTP_PCB_FLAGS_SOCKET_ALLGONE) ||
       (!SCTP_IS_LISTENING(inp)))) {
    /*
     * FIX ME ?? What about TCP model and we have a
     * match/restart case? Actually no fix is needed.
     * the lookup will always find the existing assoc so stcb
     * would not be NULL. It may be questionable to do this
     * since we COULD just send back the INIT-ACK and hope that
     * the app did accept()'s by the time the COOKIE was sent. But
     * there is a price to pay for COOKIE generation and I don't
     * want to pay it on the chance that the app will actually do
     * some accepts(). The App just looses and should NOT be in
     * this state :-)
     */
    if (SCTP_BASE_SYSCTL(sctp_blackhole) == 0) {
      op_err = sctp_generate_cause(SCTP_BASE_SYSCTL(sctp_diag_info_code),
                                   "No listener");
      sctp_send_abort(m, iphlen, src, dst, sh, 0, op_err,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                      mflowtype, mflowid, inp->fibnum,
#endif
                      vrf_id, port);
    }
    goto outnow;
  }
  if ((stcb != NULL) &&
      (SCTP_GET_STATE(stcb) == SCTP_STATE_SHUTDOWN_ACK_SENT)) {
    SCTPDBG(SCTP_DEBUG_INPUT3, "sctp_handle_init: sending SHUTDOWN-ACK\n");
    sctp_send_shutdown_ack(stcb, NULL);
    sctp_chunk_output(inp, stcb, SCTP_OUTPUT_FROM_CONTROL_PROC, SCTP_SO_NOT_LOCKED);
  } else {
    SCTPDBG(SCTP_DEBUG_INPUT3, "sctp_handle_init: sending INIT-ACK\n");
    sctp_send_initiate_ack(inp, stcb, net, m, iphlen, offset,
                           src, dst, sh, cp,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                           mflowtype, mflowid,
#endif
                           vrf_id, port);
  }
 outnow:
  if (stcb == NULL) {
    SCTP_INP_RUNLOCK(inp);
  }
}

/*
 * process peer "INIT/INIT-ACK" chunk returns value < 0 on error
 */

int
sctp_is_there_unsent_data(struct sctp_tcb *stcb, int so_locked)
{
  int unsent_data;
  unsigned int i;
  struct sctp_stream_queue_pending *sp;
  struct sctp_association *asoc;

  SCTP_TCB_LOCK_ASSERT(stcb);

  /* This function returns if any stream has true unsent data on it.
   * Note that as it looks through it will clean up any places that
   * have old data that has been sent but left at top of stream queue.
   */
  asoc = &stcb->asoc;
  unsent_data = 0;
  if (!stcb->asoc.ss_functions.sctp_ss_is_empty(stcb, asoc)) {
    /* Check to see if some data queued */
    for (i = 0; i < stcb->asoc.streamoutcnt; i++) {
      /*sa_ignore FREED_MEMORY*/
      sp = TAILQ_FIRST(&stcb->asoc.strmout[i].outqueue);
      if (sp == NULL) {
        continue;
      }
      if ((sp->msg_is_complete) &&
          (sp->length == 0) &&
          (sp->sender_all_done)) {
        /* We are doing differed cleanup. Last
         * time through when we took all the data
         * the sender_all_done was not set.
         */
        if (sp->put_last_out == 0) {
          SCTP_PRINTF("Gak, put out entire msg with NO end!-1\n");
          SCTP_PRINTF("sender_done:%d len:%d msg_comp:%d put_last_out:%d\n",
                      sp->sender_all_done,
                      sp->length,
                      sp->msg_is_complete,
                      sp->put_last_out);
        }
        atomic_subtract_int(&stcb->asoc.stream_queue_cnt, 1);
        TAILQ_REMOVE(&stcb->asoc.strmout[i].outqueue, sp, next);
        stcb->asoc.ss_functions.sctp_ss_remove_from_stream(stcb, asoc, &asoc->strmout[i], sp);
        if (sp->net) {
          sctp_free_remote_addr(sp->net);
          sp->net = NULL;
        }
        if (sp->data) {
          sctp_m_freem(sp->data);
          sp->data = NULL;
        }
        sctp_free_a_strmoq(stcb, sp, so_locked);
        if (!TAILQ_EMPTY(&stcb->asoc.strmout[i].outqueue)) {
          unsent_data++;
        }
      } else {
        unsent_data++;
      }
      if (unsent_data > 0) {
        break;
      }
    }
  }
  return (unsent_data);
}

static int
sctp_process_init(struct sctp_init_chunk *cp, struct sctp_tcb *stcb)
{
  struct sctp_init *init;
  struct sctp_association *asoc;
  struct sctp_nets *lnet;
  unsigned int i;

  SCTP_TCB_LOCK_ASSERT(stcb);

  init = &cp->init;
  asoc = &stcb->asoc;
  /* save off parameters */
  asoc->peer_vtag = ntohl(init->initiate_tag);
  asoc->peers_rwnd = ntohl(init->a_rwnd);
  /* init tsn's */
  asoc->highest_tsn_inside_map = asoc->asconf_seq_in = ntohl(init->initial_tsn) - 1;

  if (!TAILQ_EMPTY(&asoc->nets)) {
    /* update any ssthresh's that may have a default */
    TAILQ_FOREACH(lnet, &asoc->nets, sctp_next) {
      lnet->ssthresh = asoc->peers_rwnd;
      if (SCTP_BASE_SYSCTL(sctp_logging_level) & (SCTP_CWND_MONITOR_ENABLE|SCTP_CWND_LOGGING_ENABLE)) {
        sctp_log_cwnd(stcb, lnet, 0, SCTP_CWND_INITIALIZATION);
      }
    }
  }
  if (asoc->pre_open_streams > ntohs(init->num_inbound_streams)) {
    unsigned int newcnt;
    struct sctp_stream_out *outs;
    struct sctp_stream_queue_pending *sp, *nsp;
    struct sctp_tmit_chunk *chk, *nchk;

    /* abandon the upper streams */
    newcnt = ntohs(init->num_inbound_streams);
    TAILQ_FOREACH_SAFE(chk, &asoc->send_queue, sctp_next, nchk) {
      if (chk->rec.data.sid >= newcnt) {
        TAILQ_REMOVE(&asoc->send_queue, chk, sctp_next);
        asoc->send_queue_cnt--;
        if (asoc->strmout[chk->rec.data.sid].chunks_on_queues > 0) {
          asoc->strmout[chk->rec.data.sid].chunks_on_queues--;
#ifdef INVARIANTS
        } else {
          panic("No chunks on the queues for sid %u.", chk->rec.data.sid);
#endif
        }
        if (chk->data != NULL) {
          sctp_free_bufspace(stcb, asoc, chk, 1);
          sctp_ulp_notify(SCTP_NOTIFY_UNSENT_DG_FAIL, stcb,
                          0, chk, SCTP_SO_NOT_LOCKED);
          if (chk->data) {
            sctp_m_freem(chk->data);
            chk->data = NULL;
          }
        }
        sctp_free_a_chunk(stcb, chk, SCTP_SO_NOT_LOCKED);
        /*sa_ignore FREED_MEMORY*/
      }
    }
    if (asoc->strmout) {
      for (i = newcnt; i < asoc->pre_open_streams; i++) {
        outs = &asoc->strmout[i];
        TAILQ_FOREACH_SAFE(sp, &outs->outqueue, next, nsp) {
          atomic_subtract_int(&stcb->asoc.stream_queue_cnt, 1);
          TAILQ_REMOVE(&outs->outqueue, sp, next);
          stcb->asoc.ss_functions.sctp_ss_remove_from_stream(stcb, asoc, outs, sp);
          sctp_ulp_notify(SCTP_NOTIFY_SPECIAL_SP_FAIL,
              stcb, 0, sp, SCTP_SO_NOT_LOCKED);
          if (sp->data) {
            sctp_m_freem(sp->data);
            sp->data = NULL;
          }
          if (sp->net) {
            sctp_free_remote_addr(sp->net);
            sp->net = NULL;
          }
          /* Free the chunk */
          sctp_free_a_strmoq(stcb, sp, SCTP_SO_NOT_LOCKED);
          /*sa_ignore FREED_MEMORY*/
        }
        outs->state = SCTP_STREAM_CLOSED;
      }
    }
    /* cut back the count */
    asoc->pre_open_streams = newcnt;
  }
  asoc->streamoutcnt = asoc->pre_open_streams;
  if (asoc->strmout) {
    for (i = 0; i < asoc->streamoutcnt; i++) {
      asoc->strmout[i].state = SCTP_STREAM_OPEN;
    }
  }
  /* EY - nr_sack: initialize highest tsn in nr_mapping_array */
  asoc->highest_tsn_inside_nr_map = asoc->highest_tsn_inside_map;
  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_MAP_LOGGING_ENABLE) {
    sctp_log_map(0, 5, asoc->highest_tsn_inside_map, SCTP_MAP_SLIDE_RESULT);
  }
  /* This is the next one we expect */
  asoc->str_reset_seq_in = asoc->asconf_seq_in + 1;

  asoc->mapping_array_base_tsn = ntohl(init->initial_tsn);
  asoc->tsn_last_delivered = asoc->cumulative_tsn = asoc->asconf_seq_in;

  asoc->advanced_peer_ack_point = asoc->last_acked_seq;
  /* open the requested streams */

  if (asoc->strmin != NULL) {
    /* Free the old ones */
    for (i = 0; i < asoc->streamincnt; i++) {
      sctp_clean_up_stream(stcb, &asoc->strmin[i].inqueue);
      sctp_clean_up_stream(stcb, &asoc->strmin[i].uno_inqueue);
    }
    SCTP_FREE(asoc->strmin, SCTP_M_STRMI);
  }
  if (asoc->max_inbound_streams > ntohs(init->num_outbound_streams)) {
    asoc->streamincnt = ntohs(init->num_outbound_streams);
  } else {
    asoc->streamincnt = asoc->max_inbound_streams;
  }
  SCTP_MALLOC(asoc->strmin, struct sctp_stream_in *, asoc->streamincnt *
        sizeof(struct sctp_stream_in), SCTP_M_STRMI);
  if (asoc->strmin == NULL) {
    /* we didn't get memory for the streams! */
    SCTPDBG(SCTP_DEBUG_INPUT2, "process_init: couldn't get memory for the streams!\n");
    return (-1);
  }
  for (i = 0; i < asoc->streamincnt; i++) {
    asoc->strmin[i].sid = i;
    asoc->strmin[i].last_mid_delivered = 0xffffffff;
    TAILQ_INIT(&asoc->strmin[i].inqueue);
    TAILQ_INIT(&asoc->strmin[i].uno_inqueue);
    asoc->strmin[i].pd_api_started = 0;
    asoc->strmin[i].delivery_started = 0;
  }
  /*
   * load_address_from_init will put the addresses into the
   * association when the COOKIE is processed or the INIT-ACK is
   * processed. Both types of COOKIE's existing and new call this
   * routine. It will remove addresses that are no longer in the
   * association (for the restarting case where addresses are
   * removed). Up front when the INIT arrives we will discard it if it
   * is a restart and new addresses have been added.
   */
  /* sa_ignore MEMLEAK */
  return (0);
}

/*
 * INIT-ACK message processing/consumption returns value < 0 on error
 */
static int
sctp_process_init_ack(struct mbuf *m, int iphlen, int offset,
                      struct sockaddr *src, struct sockaddr *dst, struct sctphdr *sh,
                      struct sctp_init_ack_chunk *cp, struct sctp_tcb *stcb,
                      struct sctp_nets *net, int *abort_no_unlock,
#if defined(__FreeBSD__) && !defined(__Userspace__)
          uint8_t mflowtype, uint32_t mflowid,
#endif
                      uint32_t vrf_id)
{
  struct sctp_association *asoc;
  struct mbuf *op_err;
  int retval, abort_flag, cookie_found;
  int initack_limit;
  int nat_friendly = 0;

  /* First verify that we have no illegal param's */
  abort_flag = 0;
  cookie_found = 0;

  op_err = sctp_arethere_unrecognized_parameters(m,
                   (offset + sizeof(struct sctp_init_chunk)),
                   &abort_flag, (struct sctp_chunkhdr *)cp,
                   &nat_friendly, &cookie_found, NULL);
  if (abort_flag) {
    /* Send an abort and notify peer */
    sctp_abort_association(stcb->sctp_ep, stcb, m, iphlen,
                           src, dst, sh, op_err,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                           mflowtype, mflowid,
#endif
                           vrf_id, net->port);
    *abort_no_unlock = 1;
    return (-1);
  }
  if (!cookie_found) {
    uint16_t len;

    /* Only report the missing cookie parameter */
    if (op_err != NULL) {
      sctp_m_freem(op_err);
    }
    len = (uint16_t)(sizeof(struct sctp_error_missing_param) + sizeof(uint16_t));
    /* We abort with an error of missing mandatory param */
    op_err = sctp_get_mbuf_for_msg(len, 0, M_NOWAIT, 1, MT_DATA);
    if (op_err != NULL) {
      struct sctp_error_missing_param *cause;

      SCTP_BUF_LEN(op_err) = len;
      cause = mtod(op_err, struct sctp_error_missing_param *);
      /* Subtract the reserved param */
      cause->cause.code = htons(SCTP_CAUSE_MISSING_PARAM);
      cause->cause.length = htons(len);
      cause->num_missing_params = htonl(1);
      cause->type[0] = htons(SCTP_STATE_COOKIE);
    }
    sctp_abort_association(stcb->sctp_ep, stcb, m, iphlen,
                           src, dst, sh, op_err,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                           mflowtype, mflowid,
#endif
                           vrf_id, net->port);
    *abort_no_unlock = 1;
    return (-3);
  }
  asoc = &stcb->asoc;
  asoc->peer_supports_nat = (uint8_t)nat_friendly;
  /* process the peer's parameters in the INIT-ACK */
  if (sctp_process_init((struct sctp_init_chunk *)cp, stcb) < 0) {
    if (op_err != NULL) {
      sctp_m_freem(op_err);
    }
    op_err = sctp_generate_cause(SCTP_CAUSE_OUT_OF_RESC, "");
    SCTPDBG(SCTP_DEBUG_INPUT1, "sctp_process_init() failed\n");
    sctp_abort_association(stcb->sctp_ep, stcb, m, iphlen,
                           src, dst, sh, op_err,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                           mflowtype, mflowid,
#endif
                           vrf_id, net->port);
    *abort_no_unlock = 1;
    return (-1);
  }
  initack_limit = offset + ntohs(cp->ch.chunk_length);
  /* load all addresses */
  if ((retval = sctp_load_addresses_from_init(stcb, m,
                                              offset + sizeof(struct sctp_init_chunk),
                                              initack_limit, src, dst, NULL, stcb->asoc.port)) < 0) {
    if (op_err != NULL) {
      sctp_m_freem(op_err);
    }
    op_err = sctp_generate_cause(SCTP_BASE_SYSCTL(sctp_diag_info_code),
                                 "Problem with address parameters");
    SCTPDBG(SCTP_DEBUG_INPUT1,
            "Load addresses from INIT causes an abort %d\n",
            retval);
    sctp_abort_association(stcb->sctp_ep, stcb, m, iphlen,
                           src, dst, sh, op_err,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                           mflowtype, mflowid,
#endif
                           vrf_id, net->port);
    *abort_no_unlock = 1;
    return (-1);
  }
  /* if the peer doesn't support asconf, flush the asconf queue */
  if (asoc->asconf_supported == 0) {
    struct sctp_asconf_addr *param, *nparam;

    TAILQ_FOREACH_SAFE(param, &asoc->asconf_queue, next, nparam) {
      TAILQ_REMOVE(&asoc->asconf_queue, param, next);
      SCTP_FREE(param, SCTP_M_ASC_ADDR);
    }
  }

  stcb->asoc.peer_hmac_id = sctp_negotiate_hmacid(stcb->asoc.peer_hmacs,
      stcb->asoc.local_hmacs);
  if (op_err) {
    sctp_queue_op_err(stcb, op_err);
    /* queuing will steal away the mbuf chain to the out queue */
    op_err = NULL;
  }
  /* extract the cookie and queue it to "echo" it back... */
  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_THRESHOLD_LOGGING) {
    sctp_misc_ints(SCTP_THRESHOLD_CLEAR,
             stcb->asoc.overall_error_count,
             0,
             SCTP_FROM_SCTP_INPUT,
             __LINE__);
  }

  /*
   * Cancel the INIT timer, We do this first before queueing the
   * cookie. We always cancel at the primary to assume that we are
   * canceling the timer started by the INIT which always goes to the
   * primary.
   */
  sctp_timer_stop(SCTP_TIMER_TYPE_INIT, stcb->sctp_ep, stcb,
      asoc->primary_destination, SCTP_FROM_SCTP_INPUT + SCTP_LOC_3);

  /* calculate the RTO */
  if (asoc->overall_error_count == 0) {
    sctp_calculate_rto(stcb, asoc, net, &asoc->time_entered,
                       SCTP_RTT_FROM_NON_DATA);
  }
  stcb->asoc.overall_error_count = 0;
  net->error_count = 0;
#if defined(__Userspace__)
  if (stcb->sctp_ep->recv_callback) {
    if (stcb->sctp_socket) {
      uint32_t inqueue_bytes, sb_free_now;
      struct sctp_inpcb *inp;

      inp = stcb->sctp_ep;
      inqueue_bytes = stcb->asoc.total_output_queue_size - (stcb->asoc.chunks_on_out_queue * sizeof(struct sctp_data_chunk));
      sb_free_now = SCTP_SB_LIMIT_SND(stcb->sctp_socket) - (inqueue_bytes + stcb->asoc.sb_send_resv);

      /* check if the amount free in the send socket buffer crossed the threshold */
      if (inp->send_callback &&
          (((inp->send_sb_threshold > 0) &&
            (sb_free_now >= inp->send_sb_threshold) &&
            (stcb->asoc.chunks_on_out_queue <= SCTP_BASE_SYSCTL(sctp_max_chunks_on_queue))) ||
           (inp->send_sb_threshold == 0))) {
        atomic_add_int(&stcb->asoc.refcnt, 1);
        SCTP_TCB_UNLOCK(stcb);
        inp->send_callback(stcb->sctp_socket, sb_free_now, inp->ulp_info);
        SCTP_TCB_LOCK(stcb);
        atomic_subtract_int(&stcb->asoc.refcnt, 1);
      }
    }
  }
#endif
  retval = sctp_send_cookie_echo(m, offset, initack_limit, stcb, net);
  return (retval);
}

static void
sctp_handle_heartbeat_ack(struct sctp_heartbeat_chunk *cp,
    struct sctp_tcb *stcb, struct sctp_nets *net)
{
  union sctp_sockstore store;
  struct sctp_nets *r_net, *f_net;
  struct timeval tv;
  int req_prim = 0;
  uint16_t old_error_counter;

  if (ntohs(cp->ch.chunk_length) != sizeof(struct sctp_heartbeat_chunk)) {
    /* Invalid length */
    return;
  }

  memset(&store, 0, sizeof(store));
  switch (cp->heartbeat.hb_info.addr_family) {
#ifdef INET
  case AF_INET:
    if (cp->heartbeat.hb_info.addr_len == sizeof(struct sockaddr_in)) {
      store.sin.sin_family = cp->heartbeat.hb_info.addr_family;
#ifdef HAVE_SIN_LEN
      store.sin.sin_len = cp->heartbeat.hb_info.addr_len;
#endif
      store.sin.sin_port = stcb->rport;
      memcpy(&store.sin.sin_addr, cp->heartbeat.hb_info.address,
             sizeof(store.sin.sin_addr));
    } else {
      return;
    }
    break;
#endif
#ifdef INET6
  case AF_INET6:
    if (cp->heartbeat.hb_info.addr_len == sizeof(struct sockaddr_in6)) {
      store.sin6.sin6_family = cp->heartbeat.hb_info.addr_family;
#ifdef HAVE_SIN6_LEN
      store.sin6.sin6_len = cp->heartbeat.hb_info.addr_len;
#endif
      store.sin6.sin6_port = stcb->rport;
      memcpy(&store.sin6.sin6_addr, cp->heartbeat.hb_info.address, sizeof(struct in6_addr));
    } else {
      return;
    }
    break;
#endif
#if defined(__Userspace__)
  case AF_CONN:
    if (cp->heartbeat.hb_info.addr_len == sizeof(struct sockaddr_conn)) {
      store.sconn.sconn_family = cp->heartbeat.hb_info.addr_family;
#ifdef HAVE_SCONN_LEN
      store.sconn.sconn_len = cp->heartbeat.hb_info.addr_len;
#endif
      store.sconn.sconn_port = stcb->rport;
      memcpy(&store.sconn.sconn_addr, cp->heartbeat.hb_info.address, sizeof(void *));
    } else {
      return;
    }
    break;
#endif
  default:
    return;
  }
  r_net = sctp_findnet(stcb, &store.sa);
  if (r_net == NULL) {
    SCTPDBG(SCTP_DEBUG_INPUT1, "Huh? I can't find the address I sent it to, discard\n");
    return;
  }
  if ((r_net && (r_net->dest_state & SCTP_ADDR_UNCONFIRMED)) &&
      (r_net->heartbeat_random1 == cp->heartbeat.hb_info.random_value1) &&
      (r_net->heartbeat_random2 == cp->heartbeat.hb_info.random_value2)) {
    /*
     * If the its a HB and it's random value is correct when can
     * confirm the destination.
     */
    r_net->dest_state &= ~SCTP_ADDR_UNCONFIRMED;
    if (r_net->dest_state & SCTP_ADDR_REQ_PRIMARY) {
      stcb->asoc.primary_destination = r_net;
      r_net->dest_state &= ~SCTP_ADDR_REQ_PRIMARY;
      f_net = TAILQ_FIRST(&stcb->asoc.nets);
      if (f_net != r_net) {
        /* first one on the list is NOT the primary
         * sctp_cmpaddr() is much more efficient if
         * the primary is the first on the list, make it
         * so.
         */
        TAILQ_REMOVE(&stcb->asoc.nets, r_net, sctp_next);
        TAILQ_INSERT_HEAD(&stcb->asoc.nets, r_net, sctp_next);
      }
      req_prim = 1;
    }
    sctp_ulp_notify(SCTP_NOTIFY_INTERFACE_CONFIRMED,
        stcb, 0, (void *)r_net, SCTP_SO_NOT_LOCKED);
    sctp_timer_stop(SCTP_TIMER_TYPE_HEARTBEAT, stcb->sctp_ep, stcb,
                    r_net, SCTP_FROM_SCTP_INPUT + SCTP_LOC_4);
    sctp_timer_start(SCTP_TIMER_TYPE_HEARTBEAT, stcb->sctp_ep, stcb, r_net);
  }
  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_THRESHOLD_LOGGING) {
    sctp_misc_ints(SCTP_THRESHOLD_CLEAR,
             stcb->asoc.overall_error_count,
             0,
             SCTP_FROM_SCTP_INPUT,
             __LINE__);
  }
  stcb->asoc.overall_error_count = 0;
  old_error_counter = r_net->error_count;
  r_net->error_count = 0;
  r_net->hb_responded = 1;
  tv.tv_sec = cp->heartbeat.hb_info.time_value_1;
  tv.tv_usec = cp->heartbeat.hb_info.time_value_2;
  /* Now lets do a RTO with this */
  sctp_calculate_rto(stcb, &stcb->asoc, r_net, &tv,
                     SCTP_RTT_FROM_NON_DATA);
  if ((r_net->dest_state & SCTP_ADDR_REACHABLE) == 0) {
    r_net->dest_state |= SCTP_ADDR_REACHABLE;
    sctp_ulp_notify(SCTP_NOTIFY_INTERFACE_UP, stcb,
        0, (void *)r_net, SCTP_SO_NOT_LOCKED);
  }
  if (r_net->dest_state & SCTP_ADDR_PF) {
    r_net->dest_state &= ~SCTP_ADDR_PF;
    stcb->asoc.cc_functions.sctp_cwnd_update_exit_pf(stcb, net);
  }
  if (old_error_counter > 0) {
    sctp_timer_stop(SCTP_TIMER_TYPE_HEARTBEAT, stcb->sctp_ep,
                    stcb, r_net, SCTP_FROM_SCTP_INPUT + SCTP_LOC_5);
    sctp_timer_start(SCTP_TIMER_TYPE_HEARTBEAT, stcb->sctp_ep, stcb, r_net);
  }
  if (r_net == stcb->asoc.primary_destination) {
    if (stcb->asoc.alternate) {
      /* release the alternate, primary is good */
      sctp_free_remote_addr(stcb->asoc.alternate);
      stcb->asoc.alternate = NULL;
    }
  }
  /* Mobility adaptation */
  if (req_prim) {
    if ((sctp_is_mobility_feature_on(stcb->sctp_ep,
                                     SCTP_MOBILITY_BASE) ||
        sctp_is_mobility_feature_on(stcb->sctp_ep,
                                    SCTP_MOBILITY_FASTHANDOFF)) &&
        sctp_is_mobility_feature_on(stcb->sctp_ep,
                                    SCTP_MOBILITY_PRIM_DELETED)) {
      sctp_timer_stop(SCTP_TIMER_TYPE_PRIM_DELETED,
                      stcb->sctp_ep, stcb, NULL,
                      SCTP_FROM_SCTP_INPUT + SCTP_LOC_6);
      if (sctp_is_mobility_feature_on(stcb->sctp_ep,
                                      SCTP_MOBILITY_FASTHANDOFF)) {
        sctp_assoc_immediate_retrans(stcb,
                                     stcb->asoc.primary_destination);
      }
      if (sctp_is_mobility_feature_on(stcb->sctp_ep,
                                SCTP_MOBILITY_BASE)) {
        sctp_move_chunks_from_net(stcb,
                                  stcb->asoc.deleted_primary);
      }
      sctp_delete_prim_timer(stcb->sctp_ep, stcb);
    }
  }
}

static int
sctp_handle_nat_colliding_state(struct sctp_tcb *stcb)
{
  /*
   * Return 0 means we want you to proceed with the abort
   * non-zero means no abort processing.
   */
  uint32_t new_vtag;
  struct sctpasochead *head;

  if ((SCTP_GET_STATE(stcb) == SCTP_STATE_COOKIE_WAIT) ||
      (SCTP_GET_STATE(stcb) == SCTP_STATE_COOKIE_ECHOED)) {
    atomic_add_int(&stcb->asoc.refcnt, 1);
    SCTP_TCB_UNLOCK(stcb);
    SCTP_INP_INFO_WLOCK();
    SCTP_TCB_LOCK(stcb);
    atomic_subtract_int(&stcb->asoc.refcnt, 1);
  } else {
    return (0);
  }
  new_vtag = sctp_select_a_tag(stcb->sctp_ep, stcb->sctp_ep->sctp_lport, stcb->rport, 1);
  if (SCTP_GET_STATE(stcb) == SCTP_STATE_COOKIE_WAIT) {
    /* generate a new vtag and send init */
    LIST_REMOVE(stcb, sctp_asocs);
    stcb->asoc.my_vtag = new_vtag;
    head = &SCTP_BASE_INFO(sctp_asochash)[SCTP_PCBHASH_ASOC(stcb->asoc.my_vtag, SCTP_BASE_INFO(hashasocmark))];
    /* put it in the bucket in the vtag hash of assoc's for the system */
    LIST_INSERT_HEAD(head, stcb, sctp_asocs);
    SCTP_INP_INFO_WUNLOCK();
    sctp_send_initiate(stcb->sctp_ep, stcb, SCTP_SO_NOT_LOCKED);
    return (1);
  } else {
    /* treat like a case where the cookie expired i.e.:
    * - dump current cookie.
    * - generate a new vtag.
    * - resend init.
    */
    /* generate a new vtag and send init */
    LIST_REMOVE(stcb, sctp_asocs);
    SCTP_SET_STATE(stcb, SCTP_STATE_COOKIE_WAIT);
    sctp_stop_all_cookie_timers(stcb);
    sctp_toss_old_cookies(stcb, &stcb->asoc);
    stcb->asoc.my_vtag = new_vtag;
    head = &SCTP_BASE_INFO(sctp_asochash)[SCTP_PCBHASH_ASOC(stcb->asoc.my_vtag, SCTP_BASE_INFO(hashasocmark))];
    /* put it in the bucket in the vtag hash of assoc's for the system */
    LIST_INSERT_HEAD(head, stcb, sctp_asocs);
    SCTP_INP_INFO_WUNLOCK();
    sctp_send_initiate(stcb->sctp_ep, stcb, SCTP_SO_NOT_LOCKED);
    return (1);
  }
  return (0);
}

static int
sctp_handle_nat_missing_state(struct sctp_tcb *stcb,
            struct sctp_nets *net)
{
  /* return 0 means we want you to proceed with the abort
   * non-zero means no abort processing
   */
  if (stcb->asoc.auth_supported == 0) {
    SCTPDBG(SCTP_DEBUG_INPUT2, "sctp_handle_nat_missing_state: Peer does not support AUTH, cannot send an asconf\n");
    return (0);
  }
  sctp_asconf_send_nat_state_update(stcb, net);
  return (1);
}

/* Returns 1 if the stcb was aborted, 0 otherwise */
static int
sctp_handle_abort(struct sctp_abort_chunk *abort,
    struct sctp_tcb *stcb, struct sctp_nets *net)
{
#if defined(__APPLE__) && !defined(__Userspace__)
  struct socket *so;
#endif
  uint16_t len;
  uint16_t error;

  SCTPDBG(SCTP_DEBUG_INPUT2, "sctp_handle_abort: handling ABORT\n");
  if (stcb == NULL)
    return (0);

  len = ntohs(abort->ch.chunk_length);
  if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_error_cause)) {
    /* Need to check the cause codes for our
     * two magic nat aborts which don't kill the assoc
     * necessarily.
     */
    struct sctp_error_cause *cause;

    cause = (struct sctp_error_cause *)(abort + 1);
    error = ntohs(cause->code);
    if (error == SCTP_CAUSE_NAT_COLLIDING_STATE) {
      SCTPDBG(SCTP_DEBUG_INPUT2, "Received Colliding state, ABORT flags:%x\n",
                                 abort->ch.chunk_flags);
      if (sctp_handle_nat_colliding_state(stcb)) {
        return (0);
      }
    } else if (error == SCTP_CAUSE_NAT_MISSING_STATE) {
      SCTPDBG(SCTP_DEBUG_INPUT2, "Received missing state, ABORT flags:%x\n",
                                 abort->ch.chunk_flags);
      if (sctp_handle_nat_missing_state(stcb, net)) {
        return (0);
      }
    }
  } else {
    error = 0;
  }
  /* stop any receive timers */
  sctp_timer_stop(SCTP_TIMER_TYPE_RECV, stcb->sctp_ep, stcb, NULL,
                  SCTP_FROM_SCTP_INPUT + SCTP_LOC_7);
  /* notify user of the abort and clean up... */
  sctp_abort_notification(stcb, true, false, error, abort, SCTP_SO_NOT_LOCKED);
  /* free the tcb */
  SCTP_STAT_INCR_COUNTER32(sctps_aborted);
  if ((SCTP_GET_STATE(stcb) == SCTP_STATE_OPEN) ||
      (SCTP_GET_STATE(stcb) == SCTP_STATE_SHUTDOWN_RECEIVED)) {
    SCTP_STAT_DECR_GAUGE32(sctps_currestab);
  }
#ifdef SCTP_ASOCLOG_OF_TSNS
  sctp_print_out_track_log(stcb);
#endif
#if defined(__APPLE__) && !defined(__Userspace__)
  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);
#endif
  (void)sctp_free_assoc(stcb->sctp_ep, stcb, SCTP_NORMAL_PROC,
            SCTP_FROM_SCTP_INPUT + SCTP_LOC_8);
#if defined(__APPLE__) && !defined(__Userspace__)
  SCTP_SOCKET_UNLOCK(so, 1);
#endif
  SCTPDBG(SCTP_DEBUG_INPUT2, "sctp_handle_abort: finished\n");
  return (1);
}

static void
sctp_start_net_timers(struct sctp_tcb *stcb)
{
  uint32_t cnt_hb_sent;
  struct sctp_nets *net;

  cnt_hb_sent = 0;
  TAILQ_FOREACH(net, &stcb->asoc.nets, sctp_next) {
    /* For each network start:
     * 1) A pmtu timer.
     * 2) A HB timer
     * 3) If the dest in unconfirmed send
     *    a hb as well if under max_hb_burst have
     *    been sent.
     */
    sctp_timer_start(SCTP_TIMER_TYPE_PATHMTURAISE, stcb->sctp_ep, stcb, net);
    sctp_timer_start(SCTP_TIMER_TYPE_HEARTBEAT, stcb->sctp_ep, stcb, net);
    if ((net->dest_state & SCTP_ADDR_UNCONFIRMED) &&
        (cnt_hb_sent < SCTP_BASE_SYSCTL(sctp_hb_maxburst))) {
      sctp_send_hb(stcb, net, SCTP_SO_NOT_LOCKED);
      cnt_hb_sent++;
    }
  }
  if (cnt_hb_sent) {
    sctp_chunk_output(stcb->sctp_ep, stcb,
          SCTP_OUTPUT_FROM_COOKIE_ACK,
          SCTP_SO_NOT_LOCKED);
  }
}

static void
sctp_check_data_from_peer(struct sctp_tcb *stcb, int *abort_flag)
{
  char msg[SCTP_DIAG_INFO_LEN];
  struct sctp_association *asoc;
  struct mbuf *op_err;
  unsigned int i;

  *abort_flag = 0;
  asoc = &stcb->asoc;
  if (SCTP_TSN_GT(asoc->highest_tsn_inside_map, asoc->cumulative_tsn) ||
      SCTP_TSN_GT(asoc->highest_tsn_inside_nr_map, asoc->cumulative_tsn)) {
    SCTP_SNPRINTF(msg, sizeof(msg), "Missing TSN");
    *abort_flag = 1;
  }
  if (!*abort_flag) {
    for (i = 0; i < asoc->streamincnt; i++) {
      if (!TAILQ_EMPTY(&asoc->strmin[i].inqueue) ||
          !TAILQ_EMPTY(&asoc->strmin[i].uno_inqueue)) {
        SCTP_SNPRINTF(msg, sizeof(msg), "Missing user data");
        *abort_flag = 1;
        break;
      }
    }
  }
  if (*abort_flag) {
    op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
    stcb->sctp_ep->last_abort_code = SCTP_FROM_SCTP_INPUT + SCTP_LOC_9;
    sctp_abort_an_association(stcb->sctp_ep, stcb, op_err, false, SCTP_SO_NOT_LOCKED);
  }
}

static void
sctp_handle_shutdown(struct sctp_shutdown_chunk *cp,
    struct sctp_tcb *stcb, struct sctp_nets *net, int *abort_flag)
{
  int some_on_streamwheel;
  int old_state;
#if defined(__APPLE__) && !defined(__Userspace__)
  struct socket *so;
#endif

  SCTPDBG(SCTP_DEBUG_INPUT2, "sctp_handle_shutdown: handling SHUTDOWN\n");
  if (stcb == NULL)
    return;
  if ((SCTP_GET_STATE(stcb) == SCTP_STATE_COOKIE_WAIT) ||
      (SCTP_GET_STATE(stcb) == SCTP_STATE_COOKIE_ECHOED)) {
    return;
  }
  if (ntohs(cp->ch.chunk_length) != sizeof(struct sctp_shutdown_chunk)) {
    /* Shutdown NOT the expected size */
    return;
  }
  old_state = SCTP_GET_STATE(stcb);
  sctp_update_acked(stcb, cp, abort_flag);
  if (*abort_flag) {
    return;
  }
  sctp_check_data_from_peer(stcb, abort_flag);
  if (*abort_flag) {
    return;
  }
  if (stcb->sctp_socket) {
    if ((SCTP_GET_STATE(stcb) != SCTP_STATE_SHUTDOWN_RECEIVED) &&
        (SCTP_GET_STATE(stcb) != SCTP_STATE_SHUTDOWN_ACK_SENT) &&
        (SCTP_GET_STATE(stcb) != SCTP_STATE_SHUTDOWN_SENT)) {
      SCTP_SET_STATE(stcb, SCTP_STATE_SHUTDOWN_RECEIVED);
      /* notify upper layer that peer has initiated a shutdown */
      sctp_ulp_notify(SCTP_NOTIFY_PEER_SHUTDOWN, stcb, 0, NULL, SCTP_SO_NOT_LOCKED);

      /* reset time */
      (void)SCTP_GETTIME_TIMEVAL(&stcb->asoc.time_entered);
    }
  }
  if (SCTP_GET_STATE(stcb) == SCTP_STATE_SHUTDOWN_SENT) {
    /*
     * stop the shutdown timer, since we WILL move to
     * SHUTDOWN-ACK-SENT.
     */
    sctp_timer_stop(SCTP_TIMER_TYPE_SHUTDOWN, stcb->sctp_ep, stcb,
                    net, SCTP_FROM_SCTP_INPUT + SCTP_LOC_9);
  }
  /* Now is there unsent data on a stream somewhere? */
  some_on_streamwheel = sctp_is_there_unsent_data(stcb, SCTP_SO_NOT_LOCKED);

  if (!TAILQ_EMPTY(&stcb->asoc.send_queue) ||
      !TAILQ_EMPTY(&stcb->asoc.sent_queue) ||
      some_on_streamwheel) {
    /* By returning we will push more data out */
    return;
  } else {
    /* no outstanding data to send, so move on... */
    /* send SHUTDOWN-ACK */
    /* move to SHUTDOWN-ACK-SENT state */
    if ((SCTP_GET_STATE(stcb) == SCTP_STATE_OPEN) ||
        (SCTP_GET_STATE(stcb) == SCTP_STATE_SHUTDOWN_RECEIVED)) {
      SCTP_STAT_DECR_GAUGE32(sctps_currestab);
    }
    if (SCTP_GET_STATE(stcb) != SCTP_STATE_SHUTDOWN_ACK_SENT) {
      SCTP_SET_STATE(stcb, SCTP_STATE_SHUTDOWN_ACK_SENT);
      sctp_stop_timers_for_shutdown(stcb);
      sctp_send_shutdown_ack(stcb, net);
      sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWNACK,
                       stcb->sctp_ep, stcb, net);
    } else if (old_state == SCTP_STATE_SHUTDOWN_ACK_SENT) {
      sctp_send_shutdown_ack(stcb, net);
    }
  }
}

static void
sctp_handle_shutdown_ack(struct sctp_shutdown_ack_chunk *cp SCTP_UNUSED,
                         struct sctp_tcb *stcb,
                         struct sctp_nets *net)
{
  int abort_flag;
#if defined(__APPLE__) && !defined(__Userspace__)
  struct socket *so;

  so = SCTP_INP_SO(stcb->sctp_ep);
#endif
  SCTPDBG(SCTP_DEBUG_INPUT2,
          "sctp_handle_shutdown_ack: handling SHUTDOWN ACK\n");
  if (stcb == NULL) {
    return;
  }

  /* process according to association state */
  if ((SCTP_GET_STATE(stcb) == SCTP_STATE_COOKIE_WAIT) ||
      (SCTP_GET_STATE(stcb) == SCTP_STATE_COOKIE_ECHOED)) {
    /* unexpected SHUTDOWN-ACK... do OOTB handling... */
    sctp_send_shutdown_complete(stcb, net, 1);
    SCTP_TCB_UNLOCK(stcb);
    return;
  }
  if ((SCTP_GET_STATE(stcb) != SCTP_STATE_SHUTDOWN_SENT) &&
      (SCTP_GET_STATE(stcb) != SCTP_STATE_SHUTDOWN_ACK_SENT)) {
    /* unexpected SHUTDOWN-ACK... so ignore... */
    SCTP_TCB_UNLOCK(stcb);
    return;
  }
  sctp_check_data_from_peer(stcb, &abort_flag);
  if (abort_flag) {
    return;
  }
#ifdef INVARIANTS
  if (!TAILQ_EMPTY(&stcb->asoc.send_queue) ||
      !TAILQ_EMPTY(&stcb->asoc.sent_queue) ||
      sctp_is_there_unsent_data(stcb, SCTP_SO_NOT_LOCKED)) {
    panic("Queues are not empty when handling SHUTDOWN-ACK");
  }
#endif
  /* stop the timer */
  sctp_timer_stop(SCTP_TIMER_TYPE_SHUTDOWN, stcb->sctp_ep, stcb, net,
                  SCTP_FROM_SCTP_INPUT + SCTP_LOC_10);
  /* send SHUTDOWN-COMPLETE */
  sctp_send_shutdown_complete(stcb, net, 0);
  /* notify upper layer protocol */
  if (stcb->sctp_socket) {
    if ((stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_TCPTYPE) ||
        (stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_IN_TCPPOOL)) {
      SCTP_SB_CLEAR(stcb->sctp_socket->so_snd);
    }
    sctp_ulp_notify(SCTP_NOTIFY_ASSOC_DOWN, stcb, 0, NULL, SCTP_SO_NOT_LOCKED);
  }
  SCTP_STAT_INCR_COUNTER32(sctps_shutdown);
  /* free the TCB but first save off the ep */
#if defined(__APPLE__) && !defined(__Userspace__)
  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);
#endif
  (void)sctp_free_assoc(stcb->sctp_ep, stcb, SCTP_NORMAL_PROC,
                        SCTP_FROM_SCTP_INPUT + SCTP_LOC_11);
#if defined(__APPLE__) && !defined(__Userspace__)
  SCTP_SOCKET_UNLOCK(so, 1);
#endif
}

static void
sctp_process_unrecog_chunk(struct sctp_tcb *stcb, uint8_t chunk_type)
{
  switch (chunk_type) {
  case SCTP_ASCONF_ACK:
  case SCTP_ASCONF:
    sctp_asconf_cleanup(stcb);
    break;
  case SCTP_IFORWARD_CUM_TSN:
  case SCTP_FORWARD_CUM_TSN:
    stcb->asoc.prsctp_supported = 0;
    break;
  default:
    SCTPDBG(SCTP_DEBUG_INPUT2,
      "Peer does not support chunk type %d (0x%x).\n",
      chunk_type, chunk_type);
    break;
  }
}

/*
 * Skip past the param header and then we will find the param that caused the
 * problem.  There are a number of param's in a ASCONF OR the prsctp param
 * these will turn of specific features.
 * XXX: Is this the right thing to do?
 */
static void
sctp_process_unrecog_param(struct sctp_tcb *stcb, uint16_t parameter_type)
{
  switch (parameter_type) {
    /* pr-sctp draft */
  case SCTP_PRSCTP_SUPPORTED:
    stcb->asoc.prsctp_supported = 0;
    break;
  case SCTP_SUPPORTED_CHUNK_EXT:
    break;
    /* draft-ietf-tsvwg-addip-sctp */
  case SCTP_HAS_NAT_SUPPORT:
          stcb->asoc.peer_supports_nat = 0;
          break;
  case SCTP_ADD_IP_ADDRESS:
  case SCTP_DEL_IP_ADDRESS:
  case SCTP_SET_PRIM_ADDR:
    stcb->asoc.asconf_supported = 0;
    break;
  case SCTP_SUCCESS_REPORT:
  case SCTP_ERROR_CAUSE_IND:
    SCTPDBG(SCTP_DEBUG_INPUT2, "Huh, the peer does not support success? or error cause?\n");
    SCTPDBG(SCTP_DEBUG_INPUT2,
      "Turning off ASCONF to this strange peer\n");
    stcb->asoc.asconf_supported = 0;
    break;
  default:
    SCTPDBG(SCTP_DEBUG_INPUT2,
      "Peer does not support param type %d (0x%x)??\n",
      parameter_type, parameter_type);
    break;
  }
}

static int
sctp_handle_error(struct sctp_chunkhdr *ch,
                  struct sctp_tcb *stcb, struct sctp_nets *net, uint32_t limit)
{
  struct sctp_error_cause *cause;
  struct sctp_association *asoc;
  uint32_t remaining_length, adjust;
  uint16_t code, cause_code, cause_length;
#if defined(__APPLE__) && !defined(__Userspace__)
  struct socket *so;
#endif

  /* parse through all of the errors and process */
  asoc = &stcb->asoc;
  cause = (struct sctp_error_cause *)((caddr_t)ch +
      sizeof(struct sctp_chunkhdr));
  remaining_length = ntohs(ch->chunk_length);
  if (remaining_length > limit) {
    remaining_length = limit;
  }
  if (remaining_length >= sizeof(struct sctp_chunkhdr)) {
    remaining_length -= sizeof(struct sctp_chunkhdr);
  } else {
    remaining_length = 0;
  }
  code = 0;
  while (remaining_length >= sizeof(struct sctp_error_cause)) {
    /* Process an Error Cause */
    cause_code = ntohs(cause->code);
    cause_length = ntohs(cause->length);
    if ((cause_length > remaining_length) || (cause_length == 0)) {
      /* Invalid cause length, possibly due to truncation. */
      SCTPDBG(SCTP_DEBUG_INPUT1, "Bogus length in cause - bytes left: %u cause length: %u\n",
        remaining_length, cause_length);
      return (0);
    }
    if (code == 0) {
      /* report the first error cause */
      code = cause_code;
    }
    switch (cause_code) {
    case SCTP_CAUSE_INVALID_STREAM:
    case SCTP_CAUSE_MISSING_PARAM:
    case SCTP_CAUSE_INVALID_PARAM:
    case SCTP_CAUSE_NO_USER_DATA:
      SCTPDBG(SCTP_DEBUG_INPUT1, "Software error we got a %u back? We have a bug :/ (or do they?)\n",
        cause_code);
      break;
    case SCTP_CAUSE_NAT_COLLIDING_STATE:
      SCTPDBG(SCTP_DEBUG_INPUT2, "Received Colliding state, ERROR flags: %x\n",
        ch->chunk_flags);
      if (sctp_handle_nat_colliding_state(stcb)) {
        return (0);
      }
      break;
    case SCTP_CAUSE_NAT_MISSING_STATE:
      SCTPDBG(SCTP_DEBUG_INPUT2, "Received missing state, ERROR flags: %x\n",
                                 ch->chunk_flags);
      if (sctp_handle_nat_missing_state(stcb, net)) {
        return (0);
      }
      break;
    case SCTP_CAUSE_STALE_COOKIE:
      /*
       * We only act if we have echoed a cookie and are
       * waiting.
       */
      if ((cause_length >= sizeof(struct sctp_error_stale_cookie)) &&
          (SCTP_GET_STATE(stcb) == SCTP_STATE_COOKIE_ECHOED)) {
        struct timeval now;
        struct sctp_error_stale_cookie *stale_cookie;
        uint64_t stale_time;

        asoc->stale_cookie_count++;
        if (asoc->stale_cookie_count > asoc->max_init_times) {
          sctp_abort_notification(stcb, false, true, 0, NULL, SCTP_SO_NOT_LOCKED);
#if defined(__APPLE__) && !defined(__Userspace__)
          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);
#endif
          (void)sctp_free_assoc(stcb->sctp_ep, stcb, SCTP_NORMAL_PROC,
                                SCTP_FROM_SCTP_INPUT + SCTP_LOC_12);
#if defined(__APPLE__) && !defined(__Userspace__)
          SCTP_SOCKET_UNLOCK(so, 1);
#endif
          return (-1);
        }
        stale_cookie = (struct sctp_error_stale_cookie *)cause;
        stale_time = ntohl(stale_cookie->stale_time);
        if (stale_time == 0) {
          /* Use an RTT as an approximation. */
          (void)SCTP_GETTIME_TIMEVAL(&now);
          timevalsub(&now, &asoc->time_entered);
          stale_time = (uint64_t)1000000 * (uint64_t)now.tv_sec + (uint64_t)now.tv_usec;
          if (stale_time == 0) {
            stale_time = 1;
          }
        }
        /*
         * stale_time is in usec, convert it to msec.
         * Round upwards, to ensure that it is non-zero.
         */
        stale_time = (stale_time + 999) / 1000;
        /* Double it, to be more robust on RTX. */
        stale_time = 2 * stale_time;
        asoc->cookie_preserve_req = (uint32_t)stale_time;
        if (asoc->overall_error_count == 0) {
          sctp_calculate_rto(stcb, asoc, net, &asoc->time_entered,
                             SCTP_RTT_FROM_NON_DATA);
        }
        asoc->overall_error_count = 0;
        /* Blast back to INIT state */
        sctp_toss_old_cookies(stcb, &stcb->asoc);
        sctp_stop_all_cookie_timers(stcb);
        SCTP_SET_STATE(stcb, SCTP_STATE_COOKIE_WAIT);
        (void)SCTP_GETTIME_TIMEVAL(&asoc->time_entered);
        sctp_send_initiate(stcb->sctp_ep, stcb, SCTP_SO_NOT_LOCKED);
      }
      break;
    case SCTP_CAUSE_UNRESOLVABLE_ADDR:
      /*
       * Nothing we can do here, we don't do hostname
       * addresses so if the peer does not like my IPv6
       * (or IPv4 for that matter) it does not matter. If
       * they don't support that type of address, they can
       * NOT possibly get that packet type... i.e. with no
       * IPv6 you can't receive a IPv6 packet. so we can
       * safely ignore this one. If we ever added support
       * for HOSTNAME Addresses, then we would need to do
       * something here.
       */
      break;
    case SCTP_CAUSE_UNRECOG_CHUNK:
      if (cause_length >= sizeof(struct sctp_error_unrecognized_chunk)) {
        struct sctp_error_unrecognized_chunk *unrec_chunk;

        unrec_chunk = (struct sctp_error_unrecognized_chunk *)cause;
        sctp_process_unrecog_chunk(stcb, unrec_chunk->ch.chunk_type);
      }
      break;
    case SCTP_CAUSE_UNRECOG_PARAM:
      /* XXX: We only consider the first parameter */
      if (cause_length >= sizeof(struct sctp_error_cause) + sizeof(struct sctp_paramhdr)) {
        struct sctp_paramhdr *unrec_parameter;

        unrec_parameter = (struct sctp_paramhdr *)(cause + 1);
        sctp_process_unrecog_param(stcb, ntohs(unrec_parameter->param_type));
      }
      break;
    case SCTP_CAUSE_COOKIE_IN_SHUTDOWN:
      /*
       * We ignore this since the timer will drive out a
       * new cookie anyway and there timer will drive us
       * to send a SHUTDOWN_COMPLETE. We can't send one
       * here since we don't have their tag.
       */
      break;
    case SCTP_CAUSE_DELETING_LAST_ADDR:
    case SCTP_CAUSE_RESOURCE_SHORTAGE:
    case SCTP_CAUSE_DELETING_SRC_ADDR:
      /*
       * We should NOT get these here, but in a
       * ASCONF-ACK.
       */
      SCTPDBG(SCTP_DEBUG_INPUT2, "Peer sends ASCONF errors in a error cause with code %u.\n",
        cause_code);
      break;
    case SCTP_CAUSE_OUT_OF_RESC:
      /*
       * And what, pray tell do we do with the fact that
       * the peer is out of resources? Not really sure we
       * could do anything but abort. I suspect this
       * should have came WITH an abort instead of in a
       * OP-ERROR.
       */
      break;
    default:
      SCTPDBG(SCTP_DEBUG_INPUT1, "sctp_handle_error: unknown code 0x%x\n",
        cause_code);
      break;
    }
    adjust = SCTP_SIZE32(cause_length);
    if (remaining_length >= adjust) {
      remaining_length -= adjust;
    } else {
      remaining_length = 0;
    }
    cause = (struct sctp_error_cause *)((caddr_t)cause + adjust);
  }
  sctp_ulp_notify(SCTP_NOTIFY_REMOTE_ERROR, stcb, code, ch, SCTP_SO_NOT_LOCKED);
  return (0);
}

static int
sctp_handle_init_ack(struct mbuf *m, int iphlen, int offset,
                     struct sockaddr *src, struct sockaddr *dst, struct sctphdr *sh,
                     struct sctp_init_ack_chunk *cp, struct sctp_tcb *stcb,
                     struct sctp_nets *net, int *abort_no_unlock,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                     uint8_t mflowtype, uint32_t mflowid,
#endif
                     uint32_t vrf_id)
{
  struct sctp_init_ack *init_ack;
  struct mbuf *op_err;

  SCTPDBG(SCTP_DEBUG_INPUT2,
    "sctp_handle_init_ack: handling INIT-ACK\n");

  if (stcb == NULL) {
    SCTPDBG(SCTP_DEBUG_INPUT2,
      "sctp_handle_init_ack: TCB is null\n");
    return (-1);
  }
  /* Only process the INIT-ACK chunk in COOKIE WAIT state.*/
  if (SCTP_GET_STATE(stcb) == SCTP_STATE_COOKIE_WAIT) {
    init_ack = &cp->init;
    /* Validate parameters. */
    if ((ntohl(init_ack->initiate_tag) == 0) ||
        (ntohl(init_ack->a_rwnd) < SCTP_MIN_RWND) ||
        (ntohs(init_ack->num_inbound_streams) == 0) ||
        (ntohs(init_ack->num_outbound_streams) == 0)) {
      /* One of the mandatory parameters is illegal. */
      op_err = sctp_generate_cause(SCTP_CAUSE_INVALID_PARAM, "");
      sctp_abort_association(stcb->sctp_ep, stcb, m, iphlen,
                             src, dst, sh, op_err,
  #if defined(__FreeBSD__) && !defined(__Userspace__)
                             mflowtype, mflowid,
  #endif
                             vrf_id, net->port);
      *abort_no_unlock = 1;
      return (-1);
    }
    if (stcb->asoc.primary_destination->dest_state &
        SCTP_ADDR_UNCONFIRMED) {
      /*
       * The primary is where we sent the INIT, we can
       * always consider it confirmed when the INIT-ACK is
       * returned. Do this before we load addresses
       * though.
       */
      stcb->asoc.primary_destination->dest_state &=
          ~SCTP_ADDR_UNCONFIRMED;
      sctp_ulp_notify(SCTP_NOTIFY_INTERFACE_CONFIRMED,
          stcb, 0, (void *)stcb->asoc.primary_destination, SCTP_SO_NOT_LOCKED);
    }
    if (sctp_process_init_ack(m, iphlen, offset, src, dst, sh, cp, stcb,
                              net, abort_no_unlock,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                              mflowtype, mflowid,
#endif
                              vrf_id) < 0) {
      /* error in parsing parameters */
      return (-1);
    }
    /* Update our state. */
    SCTPDBG(SCTP_DEBUG_INPUT2, "moving to COOKIE-ECHOED state\n");
    SCTP_SET_STATE(stcb, SCTP_STATE_COOKIE_ECHOED);

    /* Reset the RTO calculation. */
    if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_THRESHOLD_LOGGING) {
      sctp_misc_ints(SCTP_THRESHOLD_CLEAR,
                     stcb->asoc.overall_error_count,
                     0,
                     SCTP_FROM_SCTP_INPUT,
                     __LINE__);
    }
    stcb->asoc.overall_error_count = 0;
    (void)SCTP_GETTIME_TIMEVAL(&stcb->asoc.time_entered);
    /*
     * Collapse the init timer back in case of a exponential
     * backoff.
     */
    sctp_timer_start(SCTP_TIMER_TYPE_COOKIE, stcb->sctp_ep,
        stcb, net);
    /*
     * The output routine at the end of the inbound data processing
     * will cause the cookie to be sent.
     */
    SCTPDBG(SCTP_DEBUG_INPUT1, "Leaving handle-init-ack end\n");
    return (0);
  } else {
    return (-1);
  }
}

static struct sctp_tcb *
sctp_process_cookie_new(struct mbuf *m, int iphlen, int offset,
    struct sockaddr *src, struct sockaddr *dst,
    struct sctphdr *sh, struct sctp_state_cookie *cookie, int cookie_len,
    struct sctp_inpcb *inp, struct sctp_nets **netp,
    struct sockaddr *init_src, int *notification,
    int auth_skipped, uint32_t auth_offset, uint32_t auth_len,
#if defined(__FreeBSD__) && !defined(__Userspace__)
    uint8_t mflowtype, uint32_t mflowid,
#endif
    uint32_t vrf_id, uint16_t port);

/*
 * handle a state cookie for an existing association m: input packet mbuf
 * chain-- assumes a pullup on IP/SCTP/COOKIE-ECHO chunk note: this is a
 * "split" mbuf and the cookie signature does not exist offset: offset into
 * mbuf to the cookie-echo chunk
 */
static struct sctp_tcb *
sctp_process_cookie_existing(struct mbuf *m, int iphlen, int offset,
    struct sockaddr *src, struct sockaddr *dst,
    struct sctphdr *sh, struct sctp_state_cookie *cookie, int cookie_len,
    struct sctp_inpcb *inp, struct sctp_tcb *stcb, struct sctp_nets **netp,
    struct sockaddr *init_src, int *notification,
    int auth_skipped, uint32_t auth_offset, uint32_t auth_len,
#if defined(__FreeBSD__) && !defined(__Userspace__)
    uint8_t mflowtype, uint32_t mflowid,
#endif
    uint32_t vrf_id, uint16_t port)
{
  struct sctp_association *asoc;
  struct sctp_init_chunk *init_cp, init_buf;
  struct sctp_init_ack_chunk *initack_cp, initack_buf;
  struct sctp_asconf_addr *aparam, *naparam;
  struct sctp_asconf_ack *aack, *naack;
  struct sctp_tmit_chunk *chk, *nchk;
  struct sctp_stream_reset_list *strrst, *nstrrst;
  struct sctp_queued_to_read *sq, *nsq;
  struct sctp_nets *net;
  struct mbuf *op_err;
  int init_offset, initack_offset, i;
  int retval;
  int spec_flag = 0;
  uint32_t how_indx;
#if defined(SCTP_DETAILED_STR_STATS)
  int j;
#endif

  net = *netp;
  /* I know that the TCB is non-NULL from the caller */
  asoc = &stcb->asoc;
  for (how_indx = 0; how_indx  < sizeof(asoc->cookie_how); how_indx++) {
    if (asoc->cookie_how[how_indx] == 0)
      break;
  }
  if (how_indx < sizeof(asoc->cookie_how)) {
    asoc->cookie_how[how_indx] = 1;
  }
  if (SCTP_GET_STATE(stcb) == SCTP_STATE_SHUTDOWN_ACK_SENT) {
    /* SHUTDOWN came in after sending INIT-ACK */
    sctp_send_shutdown_ack(stcb, stcb->asoc.primary_destination);
    op_err = sctp_generate_cause(SCTP_CAUSE_COOKIE_IN_SHUTDOWN, "");
    sctp_send_operr_to(src, dst, sh, cookie->peers_vtag, op_err,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                       mflowtype, mflowid, inp->fibnum,
#endif
                       vrf_id, net->port);
    if (how_indx < sizeof(asoc->cookie_how))
      asoc->cookie_how[how_indx] = 2;
    SCTP_TCB_UNLOCK(stcb);
    return (NULL);
  }
  /*
   * find and validate the INIT chunk in the cookie (peer's info) the
   * INIT should start after the cookie-echo header struct (chunk
   * header, state cookie header struct)
   */
  init_offset = offset += sizeof(struct sctp_cookie_echo_chunk);

  init_cp = (struct sctp_init_chunk *)
    sctp_m_getptr(m, init_offset, sizeof(struct sctp_init_chunk),
            (uint8_t *) & init_buf);
  if (init_cp == NULL) {
    /* could not pull a INIT chunk in cookie */
    SCTP_TCB_UNLOCK(stcb);
    return (NULL);
  }
  if (init_cp->ch.chunk_type != SCTP_INITIATION) {
    SCTP_TCB_UNLOCK(stcb);
    return (NULL);
  }
  /*
   * find and validate the INIT-ACK chunk in the cookie (my info) the
   * INIT-ACK follows the INIT chunk
   */
  initack_offset = init_offset + SCTP_SIZE32(ntohs(init_cp->ch.chunk_length));
  initack_cp = (struct sctp_init_ack_chunk *)
    sctp_m_getptr(m, initack_offset, sizeof(struct sctp_init_ack_chunk),
            (uint8_t *) & initack_buf);
  if (initack_cp == NULL) {
    /* could not pull INIT-ACK chunk in cookie */
    SCTP_TCB_UNLOCK(stcb);
    return (NULL);
  }
  if (initack_cp->ch.chunk_type != SCTP_INITIATION_ACK) {
    SCTP_TCB_UNLOCK(stcb);
    return (NULL);
  }
  if ((ntohl(initack_cp->init.initiate_tag) == asoc->my_vtag) &&
      (ntohl(init_cp->init.initiate_tag) == asoc->peer_vtag)) {
    /*
     * case D in Section 5.2.4 Table 2: MMAA process accordingly
     * to get into the OPEN state
     */
    if (ntohl(initack_cp->init.initial_tsn) != asoc->init_seq_number) {
      /*-
       * Opps, this means that we somehow generated two vtag's
       * the same. I.e. we did:
       *  Us               Peer
       *   <---INIT(tag=a)------
       *   ----INIT-ACK(tag=t)-->
       *   ----INIT(tag=t)------> *1
       *   <---INIT-ACK(tag=a)---
       *   <----CE(tag=t)------------- *2
       *
       * At point *1 we should be generating a different
       * tag t'. Which means we would throw away the CE and send
       * ours instead. Basically this is case C (throw away side).
       */
      if (how_indx < sizeof(asoc->cookie_how))
        asoc->cookie_how[how_indx] = 17;
      SCTP_TCB_UNLOCK(stcb);
      return (NULL);
    }
    switch (SCTP_GET_STATE(stcb)) {
      case SCTP_STATE_COOKIE_WAIT:
      case SCTP_STATE_COOKIE_ECHOED:
        /*
         * INIT was sent but got a COOKIE_ECHO with the
         * correct tags... just accept it...but we must
         * process the init so that we can make sure we
         * have the right seq no's.
         */
        /* First we must process the INIT !! */
        if (sctp_process_init(init_cp, stcb) < 0) {
          if (how_indx < sizeof(asoc->cookie_how))
            asoc->cookie_how[how_indx] = 3;
          op_err = sctp_generate_cause(SCTP_CAUSE_OUT_OF_RESC, "");
          SCTPDBG(SCTP_DEBUG_INPUT1, "sctp_process_init() failed\n");
          sctp_abort_association(stcb->sctp_ep, stcb, m, iphlen,
                                 src, dst, sh, op_err,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                                 mflowtype, mflowid,
#endif
                                 vrf_id, net->port);
          return (NULL);
        }
        /* we have already processed the INIT so no problem */
        sctp_timer_stop(SCTP_TIMER_TYPE_HEARTBEAT, inp,
                        stcb, net,
                        SCTP_FROM_SCTP_INPUT + SCTP_LOC_13);
        sctp_timer_stop(SCTP_TIMER_TYPE_INIT, inp,
                        stcb, net,
                        SCTP_FROM_SCTP_INPUT + SCTP_LOC_14);
        /* update current state */
        if (SCTP_GET_STATE(stcb) == SCTP_STATE_COOKIE_ECHOED)
          SCTP_STAT_INCR_COUNTER32(sctps_activeestab);
        else
          SCTP_STAT_INCR_COUNTER32(sctps_collisionestab);

        SCTP_SET_STATE(stcb, SCTP_STATE_OPEN);
        SCTP_STAT_INCR_GAUGE32(sctps_currestab);
        sctp_stop_all_cookie_timers(stcb);
        if (((stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_TCPTYPE) ||
             (stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_IN_TCPPOOL)) &&
            (!SCTP_IS_LISTENING(inp))) {
#if defined(__APPLE__) && !defined(__Userspace__)
          struct socket *so;
#endif
          /*
           * Here is where collision would go if we
           * did a connect() and instead got a
           * init/init-ack/cookie done before the
           * init-ack came back..
           */
          sctp_pcb_add_flags(stcb->sctp_ep, SCTP_PCB_FLAGS_CONNECTED);
#if defined(__APPLE__) && !defined(__Userspace__)
          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) {
            SCTP_TCB_UNLOCK(stcb);
            SCTP_SOCKET_UNLOCK(so, 1);
            return (NULL);
          }
#endif
          soisconnected(stcb->sctp_socket);
#if defined(__APPLE__) && !defined(__Userspace__)
          SCTP_SOCKET_UNLOCK(so, 1);
#endif
        }
        /* notify upper layer */
        *notification = SCTP_NOTIFY_ASSOC_UP;
        net->hb_responded = 1;
        if (stcb->asoc.sctp_autoclose_ticks &&
            (sctp_is_feature_on(inp, SCTP_PCB_FLAGS_AUTOCLOSE))) {
          sctp_timer_start(SCTP_TIMER_TYPE_AUTOCLOSE,
                           inp, stcb, NULL);
        }
        break;
      default:
        /*
         * we're in the OPEN state (or beyond), so
         * peer must have simply lost the COOKIE-ACK
         */
        break;
    } /* end switch */
    sctp_stop_all_cookie_timers(stcb);
    if ((retval = sctp_load_addresses_from_init(stcb, m,
                                          init_offset + sizeof(struct sctp_init_chunk),
                                          initack_offset, src, dst, init_src, stcb->asoc.port)) < 0) {
      if (how_indx < sizeof(asoc->cookie_how))
        asoc->cookie_how[how_indx] = 4;
      op_err = sctp_generate_cause(SCTP_BASE_SYSCTL(sctp_diag_info_code),
                                   "Problem with address parameters");
      SCTPDBG(SCTP_DEBUG_INPUT1,
              "Load addresses from INIT causes an abort %d\n",
              retval);
      sctp_abort_association(stcb->sctp_ep, stcb, m, iphlen,
                             src, dst, sh, op_err,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                             mflowtype, mflowid,
#endif
                             vrf_id, net->port);
      return (NULL);
    }
    /* respond with a COOKIE-ACK */
    sctp_toss_old_cookies(stcb, asoc);
    sctp_send_cookie_ack(stcb);
    if (how_indx < sizeof(asoc->cookie_how))
      asoc->cookie_how[how_indx] = 5;
    return (stcb);
  }

  if (ntohl(initack_cp->init.initiate_tag) != asoc->my_vtag &&
      ntohl(init_cp->init.initiate_tag) == asoc->peer_vtag &&
      cookie->tie_tag_my_vtag == 0 &&
      cookie->tie_tag_peer_vtag == 0) {
    /*
     * case C in Section 5.2.4 Table 2: XMOO silently discard
     */
    if (how_indx < sizeof(asoc->cookie_how))
      asoc->cookie_how[how_indx] = 6;
    SCTP_TCB_UNLOCK(stcb);
    return (NULL);
  }
  /* If nat support, and the below and stcb is established,
   * send back a ABORT(colliding state) if we are established.
   */
  if ((SCTP_GET_STATE(stcb) == SCTP_STATE_OPEN) &&
      (asoc->peer_supports_nat) &&
      ((ntohl(initack_cp->init.initiate_tag) == asoc->my_vtag) &&
      ((ntohl(init_cp->init.initiate_tag) != asoc->peer_vtag) ||
       (asoc->peer_vtag == 0)))) {
    /* Special case - Peer's support nat. We may have
     * two init's that we gave out the same tag on since
     * one was not established.. i.e. we get INIT from host-1
     * behind the nat and we respond tag-a, we get a INIT from
     * host-2 behind the nat and we get tag-a again. Then we
     * bring up host-1 (or 2's) assoc, Then comes the cookie
     * from hsot-2 (or 1). Now we have colliding state. We must
     * send an abort here with colliding state indication.
     */
    op_err = sctp_generate_cause(SCTP_CAUSE_NAT_COLLIDING_STATE, "");
    sctp_send_abort(m, iphlen,  src, dst, sh, 0, op_err,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                    mflowtype, mflowid, inp->fibnum,
#endif
                    vrf_id, port);
    SCTP_TCB_UNLOCK(stcb);
    return (NULL);
  }
  if ((ntohl(initack_cp->init.initiate_tag) == asoc->my_vtag) &&
      ((ntohl(init_cp->init.initiate_tag) != asoc->peer_vtag) ||
       (asoc->peer_vtag == 0))) {
    /*
     * case B in Section 5.2.4 Table 2: MXAA or MOAA my info
     * should be ok, re-accept peer info
     */
    if (ntohl(initack_cp->init.initial_tsn) != asoc->init_seq_number) {
      /* Extension of case C.
       * If we hit this, then the random number
       * generator returned the same vtag when we
       * first sent our INIT-ACK and when we later sent
       * our INIT. The side with the seq numbers that are
       * different will be the one that normally would
       * have hit case C. This in effect "extends" our vtags
       * in this collision case to be 64 bits. The same collision
       * could occur aka you get both vtag and seq number the
       * same twice in a row.. but is much less likely. If it
       * did happen then we would proceed through and bring
       * up the assoc.. we may end up with the wrong stream
       * setup however.. which would be bad.. but there is
       * no way to tell.. until we send on a stream that does
       * not exist :-)
       */
      if (how_indx < sizeof(asoc->cookie_how))
        asoc->cookie_how[how_indx] = 7;

      SCTP_TCB_UNLOCK(stcb);
      return (NULL);
    }
    if (how_indx < sizeof(asoc->cookie_how))
      asoc->cookie_how[how_indx] = 8;
    sctp_timer_stop(SCTP_TIMER_TYPE_HEARTBEAT, inp, stcb, net,
                    SCTP_FROM_SCTP_INPUT + SCTP_LOC_15);
    sctp_stop_all_cookie_timers(stcb);
    /*
     * since we did not send a HB make sure we don't double
     * things
     */
    net->hb_responded = 1;
    if (stcb->asoc.sctp_autoclose_ticks &&
        sctp_is_feature_on(inp, SCTP_PCB_FLAGS_AUTOCLOSE)) {
      sctp_timer_start(SCTP_TIMER_TYPE_AUTOCLOSE, inp, stcb,
                       NULL);
    }
    asoc->my_rwnd = ntohl(initack_cp->init.a_rwnd);
    if (asoc->pre_open_streams < asoc->streamoutcnt) {
      asoc->pre_open_streams = asoc->streamoutcnt;
    }

    if (ntohl(init_cp->init.initiate_tag) != asoc->peer_vtag) {
      /* Ok the peer probably discarded our
       * data (if we echoed a cookie+data). So anything
       * on the sent_queue should be marked for
       * retransmit, we may not get something to
       * kick us so it COULD still take a timeout
       * to move these.. but it can't hurt to mark them.
       */

      TAILQ_FOREACH(chk, &stcb->asoc.sent_queue, sctp_next) {
        if (chk->sent < SCTP_DATAGRAM_RESEND) {
          chk->sent = SCTP_DATAGRAM_RESEND;
          sctp_flight_size_decrease(chk);
          sctp_total_flight_decrease(stcb, chk);
          sctp_ucount_incr(stcb->asoc.sent_queue_retran_cnt);
          spec_flag++;
        }
      }
    }
    /* process the INIT info (peer's info) */
    if (sctp_process_init(init_cp, stcb) < 0) {
      if (how_indx < sizeof(asoc->cookie_how))
        asoc->cookie_how[how_indx] = 9;
      op_err = sctp_generate_cause(SCTP_CAUSE_OUT_OF_RESC, "");
      SCTPDBG(SCTP_DEBUG_INPUT1, "sctp_process_init() failed\n");
      sctp_abort_association(stcb->sctp_ep, stcb, m, iphlen,
                             src, dst, sh, op_err,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                             mflowtype, mflowid,
#endif
                             vrf_id, net->port);
      return (NULL);
    }
    if ((retval = sctp_load_addresses_from_init(stcb, m,
                                                init_offset + sizeof(struct sctp_init_chunk),
                                                initack_offset, src, dst, init_src, stcb->asoc.port)) < 0) {
      if (how_indx < sizeof(asoc->cookie_how))
        asoc->cookie_how[how_indx] = 10;
      op_err = sctp_generate_cause(SCTP_BASE_SYSCTL(sctp_diag_info_code),
                                   "Problem with address parameters");
      SCTPDBG(SCTP_DEBUG_INPUT1,
              "Load addresses from INIT causes an abort %d\n",
              retval);
      sctp_abort_association(stcb->sctp_ep, stcb, m, iphlen,
                             src, dst, sh, op_err,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                             mflowtype, mflowid,
#endif
                             vrf_id, net->port);
      return (NULL);
    }
    if ((SCTP_GET_STATE(stcb) == SCTP_STATE_COOKIE_WAIT) ||
        (SCTP_GET_STATE(stcb) == SCTP_STATE_COOKIE_ECHOED)) {
      *notification = SCTP_NOTIFY_ASSOC_UP;

      if (((stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_TCPTYPE) ||
           (stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_IN_TCPPOOL)) &&
          (!SCTP_IS_LISTENING(inp))) {
#if defined(__APPLE__) && !defined(__Userspace__)
        struct socket *so;
#endif
        sctp_pcb_add_flags(stcb->sctp_ep, SCTP_PCB_FLAGS_CONNECTED);
#if defined(__APPLE__) && !defined(__Userspace__)
        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) {
          SCTP_TCB_UNLOCK(stcb);
          SCTP_SOCKET_UNLOCK(so, 1);
          return (NULL);
        }
#endif
        soisconnected(stcb->sctp_socket);
#if defined(__APPLE__) && !defined(__Userspace__)
        SCTP_SOCKET_UNLOCK(so, 1);
#endif
      }
      if (SCTP_GET_STATE(stcb) == SCTP_STATE_COOKIE_ECHOED)
        SCTP_STAT_INCR_COUNTER32(sctps_activeestab);
      else
        SCTP_STAT_INCR_COUNTER32(sctps_collisionestab);
      SCTP_STAT_INCR_GAUGE32(sctps_currestab);
    } else if (SCTP_GET_STATE(stcb) == SCTP_STATE_OPEN) {
      SCTP_STAT_INCR_COUNTER32(sctps_restartestab);
    } else {
      SCTP_STAT_INCR_COUNTER32(sctps_collisionestab);
    }
    SCTP_SET_STATE(stcb, SCTP_STATE_OPEN);
    sctp_stop_all_cookie_timers(stcb);
    sctp_toss_old_cookies(stcb, asoc);
    sctp_send_cookie_ack(stcb);
    if (spec_flag) {
      /* only if we have retrans set do we do this. What
       * this call does is get only the COOKIE-ACK out
       * and then when we return the normal call to
       * sctp_chunk_output will get the retrans out
       * behind this.
       */
      sctp_chunk_output(inp,stcb, SCTP_OUTPUT_FROM_COOKIE_ACK, SCTP_SO_NOT_LOCKED);
    }
    if (how_indx < sizeof(asoc->cookie_how))
      asoc->cookie_how[how_indx] = 11;

    return (stcb);
  }
  if ((ntohl(initack_cp->init.initiate_tag) != asoc->my_vtag &&
       ntohl(init_cp->init.initiate_tag) != asoc->peer_vtag) &&
      cookie->tie_tag_my_vtag == asoc->my_vtag_nonce &&
      cookie->tie_tag_peer_vtag == asoc->peer_vtag_nonce &&
      cookie->tie_tag_peer_vtag != 0) {
    struct sctpasochead *head;
#if defined(__APPLE__) && !defined(__Userspace__)
    struct socket *so;
#endif

    if (asoc->peer_supports_nat) {
      struct sctp_tcb *local_stcb;

      /* This is a gross gross hack.
       * Just call the cookie_new code since we
       * are allowing a duplicate association.
       * I hope this works...
       */
      local_stcb = sctp_process_cookie_new(m, iphlen, offset, src, dst,
                                           sh, cookie, cookie_len,
                                           inp, netp, init_src,notification,
                                           auth_skipped, auth_offset, auth_len,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                                           mflowtype, mflowid,
#endif
                                           vrf_id, port);
      if (local_stcb == NULL) {
        SCTP_TCB_UNLOCK(stcb);
      }
      return (local_stcb);
    }
    /*
     * case A in Section 5.2.4 Table 2: XXMM (peer restarted)
     */
    /* temp code */
    if (how_indx < sizeof(asoc->cookie_how))
      asoc->cookie_how[how_indx] = 12;
    sctp_stop_association_timers(stcb, false);
    /* notify upper layer */
    *notification = SCTP_NOTIFY_ASSOC_RESTART;
    atomic_add_int(&stcb->asoc.refcnt, 1);
    if ((SCTP_GET_STATE(stcb) != SCTP_STATE_OPEN) &&
        (SCTP_GET_STATE(stcb) != SCTP_STATE_SHUTDOWN_RECEIVED) &&
        (SCTP_GET_STATE(stcb) != SCTP_STATE_SHUTDOWN_SENT)) {
      SCTP_STAT_INCR_GAUGE32(sctps_currestab);
    }
    if (SCTP_GET_STATE(stcb) == SCTP_STATE_OPEN) {
      SCTP_STAT_INCR_GAUGE32(sctps_restartestab);
    } else if (SCTP_GET_STATE(stcb) != SCTP_STATE_SHUTDOWN_SENT) {
      SCTP_STAT_INCR_GAUGE32(sctps_collisionestab);
    }
    if (asoc->state & SCTP_STATE_SHUTDOWN_PENDING) {
      SCTP_SET_STATE(stcb, SCTP_STATE_OPEN);

    } else if (SCTP_GET_STATE(stcb) != SCTP_STATE_SHUTDOWN_SENT) {
      /* move to OPEN state, if not in SHUTDOWN_SENT */
      SCTP_SET_STATE(stcb, SCTP_STATE_OPEN);
    }
    if (asoc->pre_open_streams < asoc->streamoutcnt) {
      asoc->pre_open_streams = asoc->streamoutcnt;
    }
    asoc->init_seq_number = ntohl(initack_cp->init.initial_tsn);
    asoc->sending_seq = asoc->asconf_seq_out = asoc->str_reset_seq_out = asoc->init_seq_number;
    asoc->asconf_seq_out_acked = asoc->asconf_seq_out - 1;
    asoc->asconf_seq_in = asoc->last_acked_seq = asoc->init_seq_number - 1;
    asoc->str_reset_seq_in = asoc->init_seq_number;
    asoc->advanced_peer_ack_point = asoc->last_acked_seq;
    asoc->send_sack = 1;
    asoc->data_pkts_seen = 0;
    asoc->last_data_chunk_from = NULL;
    asoc->last_control_chunk_from = NULL;
    asoc->last_net_cmt_send_started = NULL;
    if (asoc->mapping_array) {
      memset(asoc->mapping_array, 0,
             asoc->mapping_array_size);
    }
    if (asoc->nr_mapping_array) {
      memset(asoc->nr_mapping_array, 0,
          asoc->mapping_array_size);
    }
    SCTP_TCB_UNLOCK(stcb);
#if defined(__APPLE__) && !defined(__Userspace__)
    so = SCTP_INP_SO(stcb->sctp_ep);
    SCTP_SOCKET_LOCK(so, 1);
#endif
    SCTP_INP_INFO_WLOCK();
    SCTP_INP_WLOCK(stcb->sctp_ep);
    SCTP_TCB_LOCK(stcb);
    atomic_subtract_int(&stcb->asoc.refcnt, 1);
    /* send up all the data */
    sctp_report_all_outbound(stcb, 0, SCTP_SO_LOCKED);
    for (i = 0; i < stcb->asoc.streamoutcnt; i++) {
      stcb->asoc.strmout[i].chunks_on_queues = 0;
#if defined(SCTP_DETAILED_STR_STATS)
      for (j = 0; j < SCTP_PR_SCTP_MAX + 1; j++) {
        asoc->strmout[i].abandoned_sent[j] = 0;
        asoc->strmout[i].abandoned_unsent[j] = 0;
      }
#else
      asoc->strmout[i].abandoned_sent[0] = 0;
      asoc->strmout[i].abandoned_unsent[0] = 0;
#endif
      stcb->asoc.strmout[i].next_mid_ordered = 0;
      stcb->asoc.strmout[i].next_mid_unordered = 0;
      stcb->asoc.strmout[i].sid = i;
      stcb->asoc.strmout[i].last_msg_incomplete = 0;
    }
    TAILQ_FOREACH_SAFE(strrst, &asoc->resetHead, next_resp, nstrrst) {
      TAILQ_REMOVE(&asoc->resetHead, strrst, next_resp);
      SCTP_FREE(strrst, SCTP_M_STRESET);
    }
    TAILQ_FOREACH_SAFE(sq, &asoc->pending_reply_queue, next, nsq) {
      TAILQ_REMOVE(&asoc->pending_reply_queue, sq, next);
      if (sq->data) {
        sctp_m_freem(sq->data);
        sq->data = NULL;
      }
      sctp_free_remote_addr(sq->whoFrom);
      sq->whoFrom = NULL;
      sq->stcb = NULL;
      sctp_free_a_readq(stcb, sq);
    }
    TAILQ_FOREACH_SAFE(chk, &asoc->control_send_queue, sctp_next, nchk) {
      TAILQ_REMOVE(&asoc->control_send_queue, chk, sctp_next);
      if (chk->data) {
        sctp_m_freem(chk->data);
        chk->data = NULL;
      }
      if (chk->holds_key_ref)
        sctp_auth_key_release(stcb, chk->auth_keyid, SCTP_SO_LOCKED);
      sctp_free_remote_addr(chk->whoTo);
      SCTP_ZONE_FREE(SCTP_BASE_INFO(ipi_zone_chunk), chk);
      SCTP_DECR_CHK_COUNT();
    }
    asoc->ctrl_queue_cnt = 0;
    asoc->str_reset = NULL;
    asoc->stream_reset_outstanding = 0;
    TAILQ_FOREACH_SAFE(chk, &asoc->asconf_send_queue, sctp_next, nchk) {
      TAILQ_REMOVE(&asoc->asconf_send_queue, chk, sctp_next);
      if (chk->data) {
        sctp_m_freem(chk->data);
        chk->data = NULL;
      }
      if (chk->holds_key_ref)
        sctp_auth_key_release(stcb, chk->auth_keyid, SCTP_SO_LOCKED);
      sctp_free_remote_addr(chk->whoTo);
      SCTP_ZONE_FREE(SCTP_BASE_INFO(ipi_zone_chunk), chk);
      SCTP_DECR_CHK_COUNT();
    }
    TAILQ_FOREACH_SAFE(aparam, &asoc->asconf_queue, next, naparam) {
      TAILQ_REMOVE(&asoc->asconf_queue, aparam, next);
      SCTP_FREE(aparam,SCTP_M_ASC_ADDR);
    }
    TAILQ_FOREACH_SAFE(aack, &asoc->asconf_ack_sent, next, naack) {
      TAILQ_REMOVE(&asoc->asconf_ack_sent, aack, next);
      if (aack->data != NULL) {
        sctp_m_freem(aack->data);
      }
      SCTP_ZONE_FREE(SCTP_BASE_INFO(ipi_zone_asconf_ack), aack);
    }
    asoc->rcv_edmid = cookie->rcv_edmid;

    /* process the INIT-ACK info (my info) */
    asoc->my_vtag = ntohl(initack_cp->init.initiate_tag);
    asoc->my_rwnd = ntohl(initack_cp->init.a_rwnd);

    /* pull from vtag hash */
    LIST_REMOVE(stcb, sctp_asocs);
    /* re-insert to new vtag position */
    head = &SCTP_BASE_INFO(sctp_asochash)[SCTP_PCBHASH_ASOC(stcb->asoc.my_vtag,
                                                            SCTP_BASE_INFO(hashasocmark))];
    /*
     * put it in the bucket in the vtag hash of assoc's for the
     * system
     */
    LIST_INSERT_HEAD(head, stcb, sctp_asocs);

    SCTP_INP_WUNLOCK(stcb->sctp_ep);
    SCTP_INP_INFO_WUNLOCK();
#if defined(__APPLE__) && !defined(__Userspace__)
    SCTP_SOCKET_UNLOCK(so, 1);
#endif
    asoc->total_flight = 0;
    asoc->total_flight_count = 0;
    /* process the INIT info (peer's info) */
    if (sctp_process_init(init_cp, stcb) < 0) {
      if (how_indx < sizeof(asoc->cookie_how))
        asoc->cookie_how[how_indx] = 13;
      op_err = sctp_generate_cause(SCTP_CAUSE_OUT_OF_RESC, "");
      SCTPDBG(SCTP_DEBUG_INPUT1, "sctp_process_init() failed\n");
      sctp_abort_association(stcb->sctp_ep, stcb, m, iphlen,
                             src, dst, sh, op_err,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                             mflowtype, mflowid,
#endif
                             vrf_id, net->port);
      return (NULL);
    }
    /*
     * since we did not send a HB make sure we don't double
     * things
     */
    net->hb_responded = 1;

    if ((retval = sctp_load_addresses_from_init(stcb, m,
                                                init_offset + sizeof(struct sctp_init_chunk),
                                                initack_offset, src, dst, init_src, stcb->asoc.port)) < 0) {
      if (how_indx < sizeof(asoc->cookie_how))
        asoc->cookie_how[how_indx] = 14;
      op_err = sctp_generate_cause(SCTP_BASE_SYSCTL(sctp_diag_info_code),
                                   "Problem with address parameters");
      SCTPDBG(SCTP_DEBUG_INPUT1,
              "Load addresses from INIT causes an abort %d\n",
              retval);
      sctp_abort_association(stcb->sctp_ep, stcb, m, iphlen,
                             src, dst, sh, op_err,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                             mflowtype, mflowid,
#endif
                             vrf_id, net->port);
      return (NULL);
    }
    /* respond with a COOKIE-ACK */
    sctp_send_cookie_ack(stcb);
    if (how_indx < sizeof(asoc->cookie_how))
      asoc->cookie_how[how_indx] = 15;
    if (sctp_is_feature_on(inp, SCTP_PCB_FLAGS_AUTOCLOSE) &&
        (asoc->sctp_autoclose_ticks > 0)) {
      sctp_timer_start(SCTP_TIMER_TYPE_AUTOCLOSE, inp, stcb, NULL);
    }
    return (stcb);
  }
  if (how_indx < sizeof(asoc->cookie_how))
    asoc->cookie_how[how_indx] = 16;
  /* all other cases... */
  SCTP_TCB_UNLOCK(stcb);
  return (NULL);
}

/*
 * handle a state cookie for a new association m: input packet mbuf chain--
 * assumes a pullup on IP/SCTP/COOKIE-ECHO chunk note: this is a "split" mbuf
 * and the cookie signature does not exist offset: offset into mbuf to the
 * cookie-echo chunk length: length of the cookie chunk to: where the init
 * was from returns a new TCB
 */
static struct sctp_tcb *
sctp_process_cookie_new(struct mbuf *m, int iphlen, int offset,
    struct sockaddr *src, struct sockaddr *dst,
    struct sctphdr *sh, struct sctp_state_cookie *cookie, int cookie_len,
    struct sctp_inpcb *inp, struct sctp_nets **netp,
    struct sockaddr *init_src, int *notification,
    int auth_skipped, uint32_t auth_offset, uint32_t auth_len,
#if defined(__FreeBSD__) && !defined(__Userspace__)
    uint8_t mflowtype, uint32_t mflowid,
#endif
    uint32_t vrf_id, uint16_t port)
{
  struct sctp_tcb *stcb;
  struct sctp_init_chunk *init_cp, init_buf;
  struct sctp_init_ack_chunk *initack_cp, initack_buf;
  union sctp_sockstore store;
  struct sctp_association *asoc;
  int init_offset, initack_offset, initack_limit;
  int error = 0;
  uint8_t auth_chunk_buf[SCTP_CHUNK_BUFFER_SIZE];
#if defined(__APPLE__) && !defined(__Userspace__)
  struct socket *so;

  so = SCTP_INP_SO(inp);
#endif

  /*
   * find and validate the INIT chunk in the cookie (peer's info) the
   * INIT should start after the cookie-echo header struct (chunk
   * header, state cookie header struct)
   */
  init_offset = offset + sizeof(struct sctp_cookie_echo_chunk);
  init_cp = (struct sctp_init_chunk *)
      sctp_m_getptr(m, init_offset, sizeof(struct sctp_init_chunk),
      (uint8_t *) & init_buf);
  if (init_cp == NULL) {
    /* could not pull a INIT chunk in cookie */
    SCTPDBG(SCTP_DEBUG_INPUT1,
      "process_cookie_new: could not pull INIT chunk hdr\n");
    return (NULL);
  }
  if (init_cp->ch.chunk_type != SCTP_INITIATION) {
    SCTPDBG(SCTP_DEBUG_INPUT1, "HUH? process_cookie_new: could not find INIT chunk!\n");
    return (NULL);
  }
  initack_offset = init_offset + SCTP_SIZE32(ntohs(init_cp->ch.chunk_length));
  /*
   * find and validate the INIT-ACK chunk in the cookie (my info) the
   * INIT-ACK follows the INIT chunk
   */
  initack_cp = (struct sctp_init_ack_chunk *)
      sctp_m_getptr(m, initack_offset, sizeof(struct sctp_init_ack_chunk),
      (uint8_t *) & initack_buf);
  if (initack_cp == NULL) {
    /* could not pull INIT-ACK chunk in cookie */
    SCTPDBG(SCTP_DEBUG_INPUT1, "process_cookie_new: could not pull INIT-ACK chunk hdr\n");
    return (NULL);
  }
  if (initack_cp->ch.chunk_type != SCTP_INITIATION_ACK) {
    return (NULL);
  }
  /*
   * NOTE: We can't use the INIT_ACK's chk_length to determine the
   * "initack_limit" value.  This is because the chk_length field
   * includes the length of the cookie, but the cookie is omitted when
   * the INIT and INIT_ACK are tacked onto the cookie...
   */
  initack_limit = offset + cookie_len;

  /*
   * now that we know the INIT/INIT-ACK are in place, create a new TCB
   * and populate
   */

  /*
   * Here we do a trick, we set in NULL for the proc/thread argument. We
   * do this since in effect we only use the p argument when
   * the socket is unbound and we must do an implicit bind.
   * Since we are getting a cookie, we cannot be unbound.
   */
  stcb = sctp_aloc_assoc(inp, init_src, &error,
                         ntohl(initack_cp->init.initiate_tag),
                         ntohl(initack_cp->init.initial_tsn), vrf_id,
                         ntohs(initack_cp->init.num_outbound_streams),
                         port,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                         (struct thread *)NULL,
#elif defined(_WIN32) && !defined(__Userspace__)
                         (PKTHREAD)NULL,
#else
                         (struct proc *)NULL,
#endif
                         SCTP_DONT_INITIALIZE_AUTH_PARAMS);
  if (stcb == NULL) {
    struct mbuf *op_err;

    /* memory problem? */
    SCTPDBG(SCTP_DEBUG_INPUT1,
      "process_cookie_new: no room for another TCB!\n");
    op_err = sctp_generate_cause(SCTP_CAUSE_OUT_OF_RESC, "");
    sctp_abort_association(inp, (struct sctp_tcb *)NULL, m, iphlen,
                           src, dst, sh, op_err,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                           mflowtype, mflowid,
#endif
                           vrf_id, port);
    return (NULL);
  }
  asoc = &stcb->asoc;
  /* get scope variables out of cookie */
  asoc->scope.ipv4_local_scope = cookie->ipv4_scope;
  asoc->scope.site_scope = cookie->site_scope;
  asoc->scope.local_scope = cookie->local_scope;
  asoc->scope.loopback_scope = cookie->loopback_scope;

#if defined(__Userspace__)
  if ((asoc->scope.ipv4_addr_legal != cookie->ipv4_addr_legal) ||
      (asoc->scope.ipv6_addr_legal != cookie->ipv6_addr_legal) ||
      (asoc->scope.conn_addr_legal != cookie->conn_addr_legal)) {
#else
  if ((asoc->scope.ipv4_addr_legal != cookie->ipv4_addr_legal) ||
      (asoc->scope.ipv6_addr_legal != cookie->ipv6_addr_legal)) {
#endif
    struct mbuf *op_err;

    /*
     * Houston we have a problem. The EP changed while the
     * cookie was in flight. Only recourse is to abort the
     * association.
     */
    op_err = sctp_generate_cause(SCTP_CAUSE_OUT_OF_RESC, "");
    sctp_abort_association(inp, (struct sctp_tcb *)NULL, m, iphlen,
               src, dst, sh, op_err,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                           mflowtype, mflowid,
#endif
                           vrf_id, port);
#if defined(__APPLE__) && !defined(__Userspace__)
    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);
#endif
    (void)sctp_free_assoc(inp, stcb, SCTP_NORMAL_PROC,
              SCTP_FROM_SCTP_INPUT + SCTP_LOC_18);
#if defined(__APPLE__) && !defined(__Userspace__)
    SCTP_SOCKET_UNLOCK(so, 1);
#endif
    return (NULL);
  }
  asoc->rcv_edmid = cookie->rcv_edmid;
  /* process the INIT-ACK info (my info) */
  asoc->my_rwnd = ntohl(initack_cp->init.a_rwnd);

  /* process the INIT info (peer's info) */
  if (sctp_process_init(init_cp, stcb) < 0) {
#if defined(__APPLE__) && !defined(__Userspace__)
    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);
#endif
    (void)sctp_free_assoc(inp, stcb, SCTP_NORMAL_PROC,
                          SCTP_FROM_SCTP_INPUT + SCTP_LOC_19);
#if defined(__APPLE__) && !defined(__Userspace__)
    SCTP_SOCKET_UNLOCK(so, 1);
#endif
    return (NULL);
  }
  /* load all addresses */
  if (sctp_load_addresses_from_init(stcb, m,
                                    init_offset + sizeof(struct sctp_init_chunk),
                                    initack_offset, src, dst, init_src, port) < 0) {
#if defined(__APPLE__) && !defined(__Userspace__)
    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);
#endif
    (void)sctp_free_assoc(inp, stcb, SCTP_NORMAL_PROC,
                          SCTP_FROM_SCTP_INPUT + SCTP_LOC_20);
#if defined(__APPLE__) && !defined(__Userspace__)
    SCTP_SOCKET_UNLOCK(so, 1);
#endif
    return (NULL);
  }
  /*
   * verify any preceding AUTH chunk that was skipped
   */
  /* pull the local authentication parameters from the cookie/init-ack */
  sctp_auth_get_cookie_params(stcb, m,
      initack_offset + sizeof(struct sctp_init_ack_chunk),
      initack_limit - (initack_offset + sizeof(struct sctp_init_ack_chunk)));
  if (auth_skipped) {
    struct sctp_auth_chunk *auth;

    if (auth_len <= SCTP_CHUNK_BUFFER_SIZE) {
      auth = (struct sctp_auth_chunk *)sctp_m_getptr(m, auth_offset, auth_len, auth_chunk_buf);
    } else {
      auth = NULL;
    }
    if ((auth == NULL) || sctp_handle_auth(stcb, auth, m, auth_offset)) {
      /* auth HMAC failed, dump the assoc and packet */
      SCTPDBG(SCTP_DEBUG_AUTH1,
        "COOKIE-ECHO: AUTH failed\n");
#if defined(__APPLE__) && !defined(__Userspace__)
      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);
#endif
      (void)sctp_free_assoc(inp, stcb, SCTP_NORMAL_PROC,
                            SCTP_FROM_SCTP_INPUT + SCTP_LOC_21);
#if defined(__APPLE__) && !defined(__Userspace__)
      SCTP_SOCKET_UNLOCK(so, 1);
#endif
      return (NULL);
    } else {
      /* remaining chunks checked... good to go */
      stcb->asoc.authenticated = 1;
    }
  }

  /*
   * if we're doing ASCONFs, check to see if we have any new local
   * addresses that need to get added to the peer (eg. addresses
   * changed while cookie echo in flight).  This needs to be done
   * after we go to the OPEN state to do the correct asconf
   * processing. else, make sure we have the correct addresses in our
   * lists
   */

  /* warning, we re-use sin, sin6, sa_store here! */
  /* pull in local_address (our "from" address) */
  switch (cookie->laddr_type) {
#ifdef INET
  case SCTP_IPV4_ADDRESS:
    /* source addr is IPv4 */
    memset(&store.sin, 0, sizeof(struct sockaddr_in));
    store.sin.sin_family = AF_INET;
#ifdef HAVE_SIN_LEN
    store.sin.sin_len = sizeof(struct sockaddr_in);
#endif
    store.sin.sin_addr.s_addr = cookie->laddress[0];
    break;
#endif
#ifdef INET6
  case SCTP_IPV6_ADDRESS:
    /* source addr is IPv6 */
    memset(&store.sin6, 0, sizeof(struct sockaddr_in6));
    store.sin6.sin6_family = AF_INET6;
#ifdef HAVE_SIN6_LEN
    store.sin6.sin6_len = sizeof(struct sockaddr_in6);
#endif
    store.sin6.sin6_scope_id = cookie->scope_id;
    memcpy(&store.sin6.sin6_addr, cookie->laddress, sizeof(struct in6_addr));
    break;
#endif
#if defined(__Userspace__)
  case SCTP_CONN_ADDRESS:
    /* source addr is conn */
    memset(&store.sconn, 0, sizeof(struct sockaddr_conn));
    store.sconn.sconn_family = AF_CONN;
#ifdef HAVE_SCONN_LEN
    store.sconn.sconn_len = sizeof(struct sockaddr_conn);
#endif
    memcpy(&store.sconn.sconn_addr, cookie->laddress, sizeof(void *));
    break;
#endif
  default:
#if defined(__APPLE__) && !defined(__Userspace__)
    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);
#endif
    (void)sctp_free_assoc(inp, stcb, SCTP_NORMAL_PROC,
                          SCTP_FROM_SCTP_INPUT + SCTP_LOC_22);
#if defined(__APPLE__) && !defined(__Userspace__)
    SCTP_SOCKET_UNLOCK(so, 1);
#endif
    return (NULL);
  }

  /* update current state */
  SCTPDBG(SCTP_DEBUG_INPUT2, "moving to OPEN state\n");
  SCTP_SET_STATE(stcb, SCTP_STATE_OPEN);
  sctp_stop_all_cookie_timers(stcb);
  SCTP_STAT_INCR_COUNTER32(sctps_passiveestab);
  SCTP_STAT_INCR_GAUGE32(sctps_currestab);

  /* set up to notify upper layer */
  *notification = SCTP_NOTIFY_ASSOC_UP;
  if (((stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_TCPTYPE) ||
      (stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_IN_TCPPOOL)) &&
      (!SCTP_IS_LISTENING(inp))) {
    /*
     * This is an endpoint that called connect() how it got a
     * cookie that is NEW is a bit of a mystery. It must be that
     * the INIT was sent, but before it got there.. a complete
     * INIT/INIT-ACK/COOKIE arrived. But of course then it
     * should have went to the other code.. not here.. oh well..
     * a bit of protection is worth having..
     *
     * XXXMJ unlocked
     */
    sctp_pcb_add_flags(stcb->sctp_ep, SCTP_PCB_FLAGS_CONNECTED);
#if defined(__APPLE__) && !defined(__Userspace__)
    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) {
      SCTP_SOCKET_UNLOCK(so, 1);
      return (NULL);
    }
#endif
    soisconnected(stcb->sctp_socket);
#if defined(__APPLE__) && !defined(__Userspace__)
    SCTP_SOCKET_UNLOCK(so, 1);
#endif
  } else if ((stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_TCPTYPE) &&
             (SCTP_IS_LISTENING(inp))) {
    /*
     * We don't want to do anything with this one. Since it is
     * the listening guy. The timer will get started for
     * accepted connections in the caller.
     */
    ;
  }
  if (stcb->asoc.sctp_autoclose_ticks &&
      sctp_is_feature_on(inp, SCTP_PCB_FLAGS_AUTOCLOSE)) {
    sctp_timer_start(SCTP_TIMER_TYPE_AUTOCLOSE, inp, stcb, NULL);
  }
  (void)SCTP_GETTIME_TIMEVAL(&stcb->asoc.time_entered);
  *netp = sctp_findnet(stcb, init_src);
  if (*netp != NULL) {
    /*
     * Since we did not send a HB, make sure we don't double
     * things.
     */
    (*netp)->hb_responded = 1;
  }
  /* respond with a COOKIE-ACK */
  sctp_send_cookie_ack(stcb);

  /*
   * check the address lists for any ASCONFs that need to be sent
   * AFTER the cookie-ack is sent
   */
  sctp_check_address_list(stcb, m,
      initack_offset + sizeof(struct sctp_init_ack_chunk),
      initack_limit - (initack_offset + sizeof(struct sctp_init_ack_chunk)),
      &store.sa, cookie->local_scope, cookie->site_scope,
      cookie->ipv4_scope, cookie->loopback_scope);

  return (stcb);
}

/*
 * CODE LIKE THIS NEEDS TO RUN IF the peer supports the NAT extension, i.e
 * we NEED to make sure we are not already using the vtag. If so we
 * need to send back an ABORT-TRY-AGAIN-WITH-NEW-TAG No middle box bit!
  head = &SCTP_BASE_INFO(sctp_asochash)[SCTP_PCBHASH_ASOC(tag,
                  SCTP_BASE_INFO(hashasocmark))];
  LIST_FOREACH(stcb, head, sctp_asocs) {
          if ((stcb->asoc.my_vtag == tag) && (stcb->rport == rport) && (inp == stcb->sctp_ep)) {
           -- SEND ABORT - TRY AGAIN --
    }
  }
*/

/*
 * handles a COOKIE-ECHO message stcb: modified to either a new or left as
 * existing (non-NULL) TCB
 */
static struct mbuf *
sctp_handle_cookie_echo(struct mbuf *m, int iphlen, int offset,
    struct sockaddr *src, struct sockaddr *dst,
    struct sctphdr *sh, struct sctp_cookie_echo_chunk *cp,
    struct sctp_inpcb **inp_p, struct sctp_tcb **stcb, struct sctp_nets **netp,
    int auth_skipped, uint32_t auth_offset, uint32_t auth_len,
    struct sctp_tcb **locked_tcb,
#if defined(__FreeBSD__) && !defined(__Userspace__)
    uint8_t mflowtype, uint32_t mflowid,
#endif
    uint32_t vrf_id, uint16_t port)
{
  struct sctp_state_cookie *cookie;
  struct sctp_tcb *l_stcb = *stcb;
  struct sctp_inpcb *l_inp;
  struct sockaddr *to;
  struct sctp_pcb *ep;
  struct mbuf *m_sig;
  uint8_t calc_sig[SCTP_SIGNATURE_SIZE], tmp_sig[SCTP_SIGNATURE_SIZE];
  uint8_t *sig;
#if defined(__Userspace__) && defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION)
  uint8_t cookie_ok = 1;
#else
  uint8_t cookie_ok = 0;
#endif
  unsigned int sig_offset, cookie_offset;
  unsigned int cookie_len;
  struct timeval now;
  struct timeval time_entered, time_expires;
  int notification = 0;
  struct sctp_nets *netl;
  int had_a_existing_tcb = 0;
  int send_int_conf = 0;
#ifdef INET
  struct sockaddr_in sin;
#endif
#ifdef INET6
  struct sockaddr_in6 sin6;
#endif
#if defined(__Userspace__)
  struct sockaddr_conn sconn;
#endif

  SCTPDBG(SCTP_DEBUG_INPUT2,
    "sctp_handle_cookie: handling COOKIE-ECHO\n");

  if (inp_p == NULL) {
    return (NULL);
  }
  cookie = &cp->cookie;
  cookie_offset = offset + sizeof(struct sctp_chunkhdr);
  cookie_len = ntohs(cp->ch.chunk_length);

  if (cookie_len < sizeof(struct sctp_cookie_echo_chunk) +
      sizeof(struct sctp_init_chunk) +
      sizeof(struct sctp_init_ack_chunk) + SCTP_SIGNATURE_SIZE) {
    /* cookie too small */
    return (NULL);
  }
  if ((cookie->peerport != sh->src_port) ||
      (cookie->myport != sh->dest_port) ||
      (cookie->my_vtag != sh->v_tag)) {
    /*
     * invalid ports or bad tag.  Note that we always leave the
     * v_tag in the header in network order and when we stored
     * it in the my_vtag slot we also left it in network order.
     * This maintains the match even though it may be in the
     * opposite byte order of the machine :->
     */
    return (NULL);
  }
#if defined(__Userspace__)
  /*
   * Recover the AF_CONN addresses within the cookie.
   * This needs to be done in the buffer provided for later processing
   * of the cookie and in the mbuf chain for HMAC validation.
   */
  if ((cookie->addr_type == SCTP_CONN_ADDRESS) && (src->sa_family == AF_CONN)) {
    struct sockaddr_conn *sconnp = (struct sockaddr_conn *)src;

    memcpy(cookie->address, &sconnp->sconn_addr , sizeof(void *));
    m_copyback(m, cookie_offset + offsetof(struct sctp_state_cookie, address),
               (int)sizeof(void *), (caddr_t)&sconnp->sconn_addr);
  }
  if ((cookie->laddr_type == SCTP_CONN_ADDRESS) && (dst->sa_family == AF_CONN)) {
    struct sockaddr_conn *sconnp = (struct sockaddr_conn *)dst;

    memcpy(cookie->laddress, &sconnp->sconn_addr , sizeof(void *));
    m_copyback(m, cookie_offset + offsetof(struct sctp_state_cookie, laddress),
               (int)sizeof(void *), (caddr_t)&sconnp->sconn_addr);
  }
#endif
  /*
   * split off the signature into its own mbuf (since it should not be
   * calculated in the sctp_hmac_m() call).
   */
  sig_offset = offset + cookie_len - SCTP_SIGNATURE_SIZE;
  m_sig = m_split(m, sig_offset, M_NOWAIT);
  if (m_sig == NULL) {
    /* out of memory or ?? */
    return (NULL);
  }
#ifdef SCTP_MBUF_LOGGING
  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_MBUF_LOGGING_ENABLE) {
    sctp_log_mbc(m_sig, SCTP_MBUF_SPLIT);
  }
#endif

  /*
   * compute the signature/digest for the cookie
   */
  if (l_stcb != NULL) {
    atomic_add_int(&l_stcb->asoc.refcnt, 1);
    SCTP_TCB_UNLOCK(l_stcb);
  }
  l_inp = *inp_p;
  SCTP_INP_RLOCK(l_inp);
  if (l_stcb != NULL) {
    SCTP_TCB_LOCK(l_stcb);
    atomic_subtract_int(&l_stcb->asoc.refcnt, 1);
  }
  if (l_inp->sctp_flags & (SCTP_PCB_FLAGS_SOCKET_GONE | SCTP_PCB_FLAGS_SOCKET_ALLGONE)) {
    SCTP_INP_RUNLOCK(l_inp);
    sctp_m_freem(m_sig);
    return (NULL);
  }
  ep = &(*inp_p)->sctp_ep;
  /* which cookie is it? */
  if ((cookie->time_entered.tv_sec < ep->time_of_secret_change) &&
      (ep->current_secret_number != ep->last_secret_number)) {
    /* it's the old cookie */
    (void)sctp_hmac_m(SCTP_HMAC,
        (uint8_t *)ep->secret_key[(int)ep->last_secret_number],
        SCTP_SECRET_SIZE, m, cookie_offset, calc_sig, 0);
  } else {
    /* it's the current cookie */
    (void)sctp_hmac_m(SCTP_HMAC,
        (uint8_t *)ep->secret_key[(int)ep->current_secret_number],
        SCTP_SECRET_SIZE, m, cookie_offset, calc_sig, 0);
  }
  /* get the signature */
  SCTP_INP_RUNLOCK(l_inp);
  sig = (uint8_t *) sctp_m_getptr(m_sig, 0, SCTP_SIGNATURE_SIZE, (uint8_t *) & tmp_sig);
  if (sig == NULL) {
    /* couldn't find signature */
    sctp_m_freem(m_sig);
    return (NULL);
  }
  /* compare the received digest with the computed digest */
  if (timingsafe_bcmp(calc_sig, sig, SCTP_SIGNATURE_SIZE) != 0) {
    /* try the old cookie? */
    if ((cookie->time_entered.tv_sec == ep->time_of_secret_change) &&
        (ep->current_secret_number != ep->last_secret_number)) {
      /* compute digest with old */
      (void)sctp_hmac_m(SCTP_HMAC,
          (uint8_t *)ep->secret_key[(int)ep->last_secret_number],
          SCTP_SECRET_SIZE, m, cookie_offset, calc_sig, 0);
      /* compare */
      if (timingsafe_bcmp(calc_sig, sig, SCTP_SIGNATURE_SIZE) == 0)
        cookie_ok = 1;
    }
  } else {
    cookie_ok = 1;
  }

  /*
   * Now before we continue we must reconstruct our mbuf so that
   * normal processing of any other chunks will work.
   */
  {
    struct mbuf *m_at;

    m_at = m;
    while (SCTP_BUF_NEXT(m_at) != NULL) {
      m_at = SCTP_BUF_NEXT(m_at);
    }
    SCTP_BUF_NEXT(m_at) = m_sig;
  }

  if (cookie_ok == 0) {
    SCTPDBG(SCTP_DEBUG_INPUT2, "handle_cookie_echo: cookie signature validation failed!\n");
    SCTPDBG(SCTP_DEBUG_INPUT2,
      "offset = %u, cookie_offset = %u, sig_offset = %u\n",
      (uint32_t) offset, cookie_offset, sig_offset);
    return (NULL);
  }

  if (sctp_ticks_to_msecs(cookie->cookie_life) > SCTP_MAX_COOKIE_LIFE) {
    SCTPDBG(SCTP_DEBUG_INPUT2, "handle_cookie_echo: Invalid cookie lifetime\n");
    return (NULL);
  }
  time_entered.tv_sec = cookie->time_entered.tv_sec;
  time_entered.tv_usec = cookie->time_entered.tv_usec;
  if ((time_entered.tv_sec < 0) ||
      (time_entered.tv_usec < 0) ||
      (time_entered.tv_usec >= 1000000)) {
    /* Invalid time stamp. Cookie must have been modified. */
    SCTPDBG(SCTP_DEBUG_INPUT2, "handle_cookie_echo: Invalid time stamp\n");
    return (NULL);
  }
  (void)SCTP_GETTIME_TIMEVAL(&now);
#if !(defined(__FreeBSD__) && !defined(__Userspace__))
  if (timercmp(&now, &time_entered, <)) {
#else
  if (timevalcmp(&now, &time_entered, <)) {
#endif
    SCTPDBG(SCTP_DEBUG_INPUT2, "handle_cookie_echo: cookie generated in the future!\n");
    return (NULL);
  }
  /*
   * Check the cookie timestamps to be sure it's not stale.
   * cookie_life is in ticks, so we convert to seconds.
   */
  time_expires.tv_sec = time_entered.tv_sec + sctp_ticks_to_secs(cookie->cookie_life);
  time_expires.tv_usec = time_entered.tv_usec;
#if !(defined(__FreeBSD__) && !defined(__Userspace__))
  if (timercmp(&now, &time_expires, >))
#else
  if (timevalcmp(&now, &time_expires, >))
#endif
  {
    /* cookie is stale! */
    struct mbuf *op_err;
    struct sctp_error_stale_cookie *cause;
    struct timeval diff;
    uint32_t staleness;

    op_err = sctp_get_mbuf_for_msg(sizeof(struct sctp_error_stale_cookie),
                                   0, M_NOWAIT, 1, MT_DATA);
    if (op_err == NULL) {
      /* FOOBAR */
      return (NULL);
    }
    /* Set the len */
    SCTP_BUF_LEN(op_err) = sizeof(struct sctp_error_stale_cookie);
    cause = mtod(op_err, struct sctp_error_stale_cookie *);
    cause->cause.code = htons(SCTP_CAUSE_STALE_COOKIE);
    cause->cause.length = htons(sizeof(struct sctp_error_stale_cookie));
#if !(defined(__FreeBSD__) && !defined(__Userspace__))
    timersub(&now, &time_expires, &diff);
#else
    diff = now;
    timevalsub(&diff, &time_expires);
#endif
    if ((uint32_t)diff.tv_sec > UINT32_MAX / 1000000) {
      staleness = UINT32_MAX;
    } else {
      staleness = (uint32_t)diff.tv_sec * 1000000;
    }
    if (UINT32_MAX - staleness >= (uint32_t)diff.tv_usec) {
      staleness += (uint32_t)diff.tv_usec;
    } else {
      staleness = UINT32_MAX;
    }
    cause->stale_time = htonl(staleness);
    sctp_send_operr_to(src, dst, sh, cookie->peers_vtag, op_err,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                       mflowtype, mflowid, l_inp->fibnum,
#endif
                       vrf_id, port);
    return (NULL);
  }
  /*
   * Now we must see with the lookup address if we have an existing
   * asoc. This will only happen if we were in the COOKIE-WAIT state
   * and a INIT collided with us and somewhere the peer sent the
   * cookie on another address besides the single address our assoc
   * had for him. In this case we will have one of the tie-tags set at
   * least AND the address field in the cookie can be used to look it
   * up.
   */
  to = NULL;
  switch (cookie->addr_type) {
#ifdef INET6
  case SCTP_IPV6_ADDRESS:
    memset(&sin6, 0, sizeof(sin6));
    sin6.sin6_family = AF_INET6;
#ifdef HAVE_SIN6_LEN
    sin6.sin6_len = sizeof(sin6);
#endif
    sin6.sin6_port = sh->src_port;
    sin6.sin6_scope_id = cookie->scope_id;
    memcpy(&sin6.sin6_addr.s6_addr, cookie->address,
        sizeof(sin6.sin6_addr.s6_addr));
    to = (struct sockaddr *)&sin6;
    break;
#endif
#ifdef INET
  case SCTP_IPV4_ADDRESS:
    memset(&sin, 0, sizeof(sin));
    sin.sin_family = AF_INET;
#ifdef HAVE_SIN_LEN
    sin.sin_len = sizeof(sin);
#endif
    sin.sin_port = sh->src_port;
    sin.sin_addr.s_addr = cookie->address[0];
    to = (struct sockaddr *)&sin;
    break;
#endif
#if defined(__Userspace__)
  case SCTP_CONN_ADDRESS:
    memset(&sconn, 0, sizeof(struct sockaddr_conn));
    sconn.sconn_family = AF_CONN;
#ifdef HAVE_SCONN_LEN
    sconn.sconn_len = sizeof(struct sockaddr_conn);
#endif
    sconn.sconn_port = sh->src_port;
    memcpy(&sconn.sconn_addr, cookie->address, sizeof(void *));
    to = (struct sockaddr *)&sconn;
    break;
#endif
  default:
    /* This should not happen */
    return (NULL);
  }
  if (*stcb == NULL) {
    /* Yep, lets check */
    *stcb = sctp_findassociation_ep_addr(inp_p, to, netp, dst, NULL);
    if (*stcb == NULL) {
      /*
       * We should have only got back the same inp. If we
       * got back a different ep we have a problem. The
       * original findep got back l_inp and now
       */
      if (l_inp != *inp_p) {
        SCTP_PRINTF("Bad problem find_ep got a diff inp then special_locate?\n");
      }
    } else {
      if (*locked_tcb == NULL) {
        /* In this case we found the assoc only
         * after we locked the create lock. This means
         * we are in a colliding case and we must make
         * sure that we unlock the tcb if its one of the
         * cases where we throw away the incoming packets.
         */
        *locked_tcb = *stcb;

        /* We must also increment the inp ref count
         * since the ref_count flags was set when we
         * did not find the TCB, now we found it which
         * reduces the refcount.. we must raise it back
         * out to balance it all :-)
         */
        SCTP_INP_INCR_REF((*stcb)->sctp_ep);
        if ((*stcb)->sctp_ep != l_inp) {
          SCTP_PRINTF("Huh? ep:%p diff then l_inp:%p?\n",
                (void *)(*stcb)->sctp_ep, (void *)l_inp);
        }
      }
    }
  }

  cookie_len -= SCTP_SIGNATURE_SIZE;
  if (*stcb == NULL) {
    /* this is the "normal" case... get a new TCB */
    *stcb = sctp_process_cookie_new(m, iphlen, offset, src, dst, sh,
                                    cookie, cookie_len, *inp_p,
                                    netp, to, &notification,
                                    auth_skipped, auth_offset, auth_len,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                                    mflowtype, mflowid,
#endif
                                    vrf_id, port);
  } else {
    /* this is abnormal... cookie-echo on existing TCB */
    had_a_existing_tcb = 1;
    *stcb = sctp_process_cookie_existing(m, iphlen, offset,
                                         src, dst, sh,
                                         cookie, cookie_len, *inp_p, *stcb, netp, to,
                                         &notification, auth_skipped, auth_offset, auth_len,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                                         mflowtype, mflowid,
#endif
                                         vrf_id, port);
    if (*stcb == NULL) {
      *locked_tcb = NULL;
    }
  }

  if (*stcb == NULL) {
    /* still no TCB... must be bad cookie-echo */
    return (NULL);
  }
#if defined(__FreeBSD__) && !defined(__Userspace__)
  if (*netp != NULL) {
    (*netp)->flowtype = mflowtype;
    (*netp)->flowid = mflowid;
  }
#endif
  /*
   * Ok, we built an association so confirm the address we sent the
   * INIT-ACK to.
   */
  netl = sctp_findnet(*stcb, to);
  /*
   * This code should in theory NOT run but
   */
  if (netl == NULL) {
    /* TSNH! Huh, why do I need to add this address here? */
    if (sctp_add_remote_addr(*stcb, to, NULL, port,
                             SCTP_DONOT_SETSCOPE, SCTP_IN_COOKIE_PROC)) {
      return (NULL);
    }
    netl = sctp_findnet(*stcb, to);
  }
  if (netl) {
    if (netl->dest_state & SCTP_ADDR_UNCONFIRMED) {
      netl->dest_state &= ~SCTP_ADDR_UNCONFIRMED;
      (void)sctp_set_primary_addr((*stcb), (struct sockaddr *)NULL,
          netl);
      send_int_conf = 1;
    }
  }
  sctp_start_net_timers(*stcb);
  if ((*inp_p)->sctp_flags & SCTP_PCB_FLAGS_TCPTYPE) {
    if (!had_a_existing_tcb ||
        (((*inp_p)->sctp_flags & SCTP_PCB_FLAGS_CONNECTED) == 0)) {
      /*
       * If we have a NEW cookie or the connect never
       * reached the connected state during collision we
       * must do the TCP accept thing.
       */
      struct socket *so, *oso;
      struct sctp_inpcb *inp;

      if (notification == SCTP_NOTIFY_ASSOC_RESTART) {
        /*
         * For a restart we will keep the same
         * socket, no need to do anything. I THINK!!
         */
        sctp_ulp_notify(notification, *stcb, 0, NULL, SCTP_SO_NOT_LOCKED);
        if (send_int_conf) {
          sctp_ulp_notify(SCTP_NOTIFY_INTERFACE_CONFIRMED,
                          (*stcb), 0, (void *)netl, SCTP_SO_NOT_LOCKED);
        }
        return (m);
      }
      oso = (*inp_p)->sctp_socket;
      atomic_add_int(&(*stcb)->asoc.refcnt, 1);
      SCTP_TCB_UNLOCK((*stcb));
#if defined(__FreeBSD__) && !defined(__Userspace__)
      CURVNET_SET(oso->so_vnet);
#endif
#if defined(__APPLE__) && !defined(__Userspace__)
      SCTP_SOCKET_LOCK(oso, 1);
#endif
      so = sonewconn(oso, 0
#if defined(__APPLE__) && !defined(__Userspace__)
          ,NULL
#endif
          );
#if defined(__APPLE__) && !defined(__Userspace__)
      SCTP_SOCKET_UNLOCK(oso, 1);
#endif
#if defined(__FreeBSD__) && !defined(__Userspace__)
      CURVNET_RESTORE();
#endif
      SCTP_TCB_LOCK((*stcb));
      atomic_subtract_int(&(*stcb)->asoc.refcnt, 1);

      if (so == NULL) {
        struct mbuf *op_err;
#if defined(__APPLE__) && !defined(__Userspace__)
        struct socket *pcb_so;
#endif
        /* Too many sockets */
        SCTPDBG(SCTP_DEBUG_INPUT1, "process_cookie_new: no room for another socket!\n");
        op_err = sctp_generate_cause(SCTP_CAUSE_OUT_OF_RESC, "");
        sctp_abort_association(*inp_p, NULL, m, iphlen,
                   src, dst, sh, op_err,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                               mflowtype, mflowid,
#endif
                               vrf_id, port);
#if defined(__APPLE__) && !defined(__Userspace__)
        pcb_so = SCTP_INP_SO(*inp_p);
        atomic_add_int(&(*stcb)->asoc.refcnt, 1);
        SCTP_TCB_UNLOCK((*stcb));
        SCTP_SOCKET_LOCK(pcb_so, 1);
        SCTP_TCB_LOCK((*stcb));
        atomic_subtract_int(&(*stcb)->asoc.refcnt, 1);
#endif
        (void)sctp_free_assoc(*inp_p, *stcb, SCTP_NORMAL_PROC,
                              SCTP_FROM_SCTP_INPUT + SCTP_LOC_23);
#if defined(__APPLE__) && !defined(__Userspace__)
        SCTP_SOCKET_UNLOCK(pcb_so, 1);
#endif
        return (NULL);
      }
      inp = (struct sctp_inpcb *)so->so_pcb;
      SCTP_INP_INCR_REF(inp);
      /*
       * We add the unbound flag here so that
       * if we get an soabort() before we get the
       * move_pcb done, we will properly cleanup.
       */
      inp->sctp_flags = (SCTP_PCB_FLAGS_TCPTYPE |
          SCTP_PCB_FLAGS_CONNECTED |
          SCTP_PCB_FLAGS_IN_TCPPOOL |
          SCTP_PCB_FLAGS_UNBOUND |
          (SCTP_PCB_COPY_FLAGS & (*inp_p)->sctp_flags) |
          SCTP_PCB_FLAGS_DONT_WAKE);
      inp->sctp_features = (*inp_p)->sctp_features;
      inp->sctp_mobility_features = (*inp_p)->sctp_mobility_features;
      inp->sctp_socket = so;
      inp->sctp_frag_point = (*inp_p)->sctp_frag_point;
      inp->max_cwnd = (*inp_p)->max_cwnd;
      inp->sctp_cmt_on_off = (*inp_p)->sctp_cmt_on_off;
      inp->ecn_supported = (*inp_p)->ecn_supported;
      inp->prsctp_supported = (*inp_p)->prsctp_supported;
      inp->auth_supported = (*inp_p)->auth_supported;
      inp->asconf_supported = (*inp_p)->asconf_supported;
      inp->reconfig_supported = (*inp_p)->reconfig_supported;
      inp->nrsack_supported = (*inp_p)->nrsack_supported;
      inp->pktdrop_supported = (*inp_p)->pktdrop_supported;
      inp->partial_delivery_point = (*inp_p)->partial_delivery_point;
      inp->sctp_context = (*inp_p)->sctp_context;
      inp->local_strreset_support = (*inp_p)->local_strreset_support;
      inp->fibnum = (*inp_p)->fibnum;
#if defined(__Userspace__)
      inp->ulp_info = (*inp_p)->ulp_info;
      inp->recv_callback = (*inp_p)->recv_callback;
      inp->send_callback = (*inp_p)->send_callback;
      inp->send_sb_threshold = (*inp_p)->send_sb_threshold;
#endif
      /*
       * copy in the authentication parameters from the
       * original endpoint
       */
      if (inp->sctp_ep.local_hmacs)
        sctp_free_hmaclist(inp->sctp_ep.local_hmacs);
      inp->sctp_ep.local_hmacs =
          sctp_copy_hmaclist((*inp_p)->sctp_ep.local_hmacs);
      if (inp->sctp_ep.local_auth_chunks)
        sctp_free_chunklist(inp->sctp_ep.local_auth_chunks);
      inp->sctp_ep.local_auth_chunks =
          sctp_copy_chunklist((*inp_p)->sctp_ep.local_auth_chunks);

      /*
       * Now we must move it from one hash table to
       * another and get the tcb in the right place.
       */

      /* This is where the one-2-one socket is put into
       * the accept state waiting for the accept!
       */
      if (*stcb) {
        SCTP_ADD_SUBSTATE(*stcb, SCTP_STATE_IN_ACCEPT_QUEUE);
      }
      sctp_move_pcb_and_assoc(*inp_p, inp, *stcb);

      atomic_add_int(&(*stcb)->asoc.refcnt, 1);
      SCTP_TCB_UNLOCK((*stcb));

#if defined(__FreeBSD__) && !defined(__Userspace__)
      sctp_pull_off_control_to_new_inp((*inp_p), inp, *stcb,
          0);
#else
      sctp_pull_off_control_to_new_inp((*inp_p), inp, *stcb, M_NOWAIT);
#endif
      SCTP_TCB_LOCK((*stcb));
      atomic_subtract_int(&(*stcb)->asoc.refcnt, 1);

      /* now we must check to see if we were aborted while
       * the move was going on and the lock/unlock happened.
       */
      if (inp->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE) {
        /* yep it was, we leave the
         * assoc attached to the socket since
         * the sctp_inpcb_free() call will send
         * an abort for us.
         */
        SCTP_INP_DECR_REF(inp);
        return (NULL);
      }
      SCTP_INP_DECR_REF(inp);
      /* Switch over to the new guy */
      *inp_p = inp;
      sctp_ulp_notify(notification, *stcb, 0, NULL, SCTP_SO_NOT_LOCKED);
      if (send_int_conf) {
        sctp_ulp_notify(SCTP_NOTIFY_INTERFACE_CONFIRMED,
                        (*stcb), 0, (void *)netl, SCTP_SO_NOT_LOCKED);
      }

      /* Pull it from the incomplete queue and wake the guy */
#if defined(__APPLE__) && !defined(__Userspace__)
      atomic_add_int(&(*stcb)->asoc.refcnt, 1);
      SCTP_TCB_UNLOCK((*stcb));
      SCTP_SOCKET_LOCK(so, 1);
#endif
      soisconnected(so);
#if defined(__APPLE__) && !defined(__Userspace__)
      SCTP_TCB_LOCK((*stcb));
      atomic_subtract_int(&(*stcb)->asoc.refcnt, 1);
      SCTP_SOCKET_UNLOCK(so, 1);
#endif
      return (m);
    }
  }
  if (notification) {
    sctp_ulp_notify(notification, *stcb, 0, NULL, SCTP_SO_NOT_LOCKED);
  }
  if (send_int_conf) {
    sctp_ulp_notify(SCTP_NOTIFY_INTERFACE_CONFIRMED,
                    (*stcb), 0, (void *)netl, SCTP_SO_NOT_LOCKED);
  }
  return (m);
}

static void
sctp_handle_cookie_ack(struct sctp_cookie_ack_chunk *cp SCTP_UNUSED,
    struct sctp_tcb *stcb, struct sctp_nets *net)
{
  /* cp must not be used, others call this without a c-ack :-) */
  struct sctp_association *asoc;
  struct sctp_tmit_chunk *chk;

  SCTPDBG(SCTP_DEBUG_INPUT2,
    "sctp_handle_cookie_ack: handling COOKIE-ACK\n");
  if ((stcb == NULL) || (net == NULL)) {
    return;
  }

  asoc = &stcb->asoc;
  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_THRESHOLD_LOGGING) {
    sctp_misc_ints(SCTP_THRESHOLD_CLEAR,
             asoc->overall_error_count,
             0,
             SCTP_FROM_SCTP_INPUT,
             __LINE__);
  }
  sctp_stop_all_cookie_timers(stcb);
  sctp_toss_old_cookies(stcb, asoc);
  /* process according to association state */
  if (SCTP_GET_STATE(stcb) == SCTP_STATE_COOKIE_ECHOED) {
    /* state change only needed when I am in right state */
    SCTPDBG(SCTP_DEBUG_INPUT2, "moving to OPEN state\n");
    SCTP_SET_STATE(stcb, SCTP_STATE_OPEN);
    sctp_start_net_timers(stcb);
    /* update RTO */
    SCTP_STAT_INCR_COUNTER32(sctps_activeestab);
    SCTP_STAT_INCR_GAUGE32(sctps_currestab);
    if (asoc->overall_error_count == 0) {
      sctp_calculate_rto(stcb, asoc, net, &asoc->time_entered,
                         SCTP_RTT_FROM_NON_DATA);
    }
    /*
     * Since we did not send a HB make sure we don't double
     * things.
     */
    asoc->overall_error_count = 0;
    net->hb_responded = 1;
    (void)SCTP_GETTIME_TIMEVAL(&asoc->time_entered);
    sctp_ulp_notify(SCTP_NOTIFY_ASSOC_UP, stcb, 0, NULL, SCTP_SO_NOT_LOCKED);
    if ((stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_TCPTYPE) ||
        (stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_IN_TCPPOOL)) {
#if defined(__APPLE__) && !defined(__Userspace__)
      struct socket *so;

#endif
      sctp_pcb_add_flags(stcb->sctp_ep, SCTP_PCB_FLAGS_CONNECTED);
#if defined(__APPLE__) && !defined(__Userspace__)
      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);
#endif
      if ((stcb->asoc.state & SCTP_STATE_CLOSED_SOCKET) == 0) {
        soisconnected(stcb->sctp_socket);
      }
#if defined(__APPLE__) && !defined(__Userspace__)
      SCTP_SOCKET_UNLOCK(so, 1);
#endif
    }

    if ((asoc->state & SCTP_STATE_SHUTDOWN_PENDING) &&
        TAILQ_EMPTY(&asoc->send_queue) &&
        TAILQ_EMPTY(&asoc->sent_queue) &&
        (asoc->stream_queue_cnt == 0)) {
      SCTP_STAT_DECR_GAUGE32(sctps_currestab);
      SCTP_SET_STATE(stcb, SCTP_STATE_SHUTDOWN_SENT);
      sctp_stop_timers_for_shutdown(stcb);
      sctp_send_shutdown(stcb, net);
      sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWN,
                       stcb->sctp_ep, stcb, net);
      sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWNGUARD,
                       stcb->sctp_ep, stcb, NULL);
      sctp_chunk_output(stcb->sctp_ep, stcb, SCTP_OUTPUT_FROM_T3, SCTP_SO_LOCKED);
    }

    if (stcb->asoc.state & SCTP_STATE_CLOSED_SOCKET) {
      /* We don't need to do the asconf thing,
       * nor hb or autoclose if the socket is closed.
       */
      goto closed_socket;
    }

    sctp_timer_start(SCTP_TIMER_TYPE_HEARTBEAT, stcb->sctp_ep,
        stcb, net);

    if (stcb->asoc.sctp_autoclose_ticks &&
        sctp_is_feature_on(stcb->sctp_ep, SCTP_PCB_FLAGS_AUTOCLOSE)) {
      sctp_timer_start(SCTP_TIMER_TYPE_AUTOCLOSE,
          stcb->sctp_ep, stcb, NULL);
    }
    /*
     * send ASCONF if parameters are pending and ASCONFs are
     * allowed (eg. addresses changed when init/cookie echo were
     * in flight)
     */
    if ((sctp_is_feature_on(stcb->sctp_ep, SCTP_PCB_FLAGS_DO_ASCONF)) &&
        (stcb->asoc.asconf_supported == 1) &&
        (!TAILQ_EMPTY(&stcb->asoc.asconf_queue))) {
#ifdef SCTP_TIMER_BASED_ASCONF
      sctp_timer_start(SCTP_TIMER_TYPE_ASCONF,
           stcb->sctp_ep, stcb,
           stcb->asoc.primary_destination);
#else
      sctp_send_asconf(stcb, stcb->asoc.primary_destination,
           SCTP_ADDR_NOT_LOCKED);
#endif
    }
  }
closed_socket:
  /* Restart the timer if we have pending data */
  TAILQ_FOREACH(chk, &asoc->sent_queue, sctp_next) {
    if (chk->whoTo != NULL) {
      break;
    }
  }
  if (chk != NULL) {
    sctp_timer_start(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep, stcb, chk->whoTo);
  }
}

static void
sctp_handle_ecn_echo(struct sctp_ecne_chunk *cp,
         struct sctp_tcb *stcb)
{
  struct sctp_nets *net;
  struct sctp_tmit_chunk *lchk;
  struct sctp_ecne_chunk bkup;
  uint8_t override_bit;
  uint32_t tsn, window_data_tsn;
  int len;
  unsigned int pkt_cnt;

  len = ntohs(cp->ch.chunk_length);
  if (len == sizeof(struct old_sctp_ecne_chunk)) {
    /* Its the old format */
    memcpy(&bkup, cp, sizeof(struct old_sctp_ecne_chunk));
    bkup.num_pkts_since_cwr = htonl(1);
    cp = &bkup;
  }
  SCTP_STAT_INCR(sctps_recvecne);
  tsn = ntohl(cp->tsn);
  pkt_cnt = ntohl(cp->num_pkts_since_cwr);
  lchk = TAILQ_LAST(&stcb->asoc.send_queue, sctpchunk_listhead);
  if (lchk == NULL) {
    window_data_tsn = stcb->asoc.sending_seq - 1;
  } else {
    window_data_tsn = lchk->rec.data.tsn;
  }

  /* Find where it was sent to if possible. */
  net = NULL;
  TAILQ_FOREACH(lchk, &stcb->asoc.sent_queue, sctp_next) {
    if (lchk->rec.data.tsn == tsn) {
      net = lchk->whoTo;
      net->ecn_prev_cwnd = lchk->rec.data.cwnd_at_send;
      break;
    }
    if (SCTP_TSN_GT(lchk->rec.data.tsn, tsn)) {
      break;
    }
  }
  if (net == NULL) {
    /*
     * What to do. A previous send of a
     * CWR was possibly lost. See how old it is, we
     * may have it marked on the actual net.
     */
    TAILQ_FOREACH(net, &stcb->asoc.nets, sctp_next) {
      if (tsn == net->last_cwr_tsn) {
        /* Found him, send it off */
        break;
      }
    }
    if (net == NULL) {
      /*
       * If we reach here, we need to send a special
       * CWR that says hey, we did this a long time
       * ago and you lost the response.
       */
      net = TAILQ_FIRST(&stcb->asoc.nets);
      if (net == NULL) {
        /* TSNH */
        return;
      }
      override_bit = SCTP_CWR_REDUCE_OVERRIDE;
    } else {
      override_bit = 0;
    }
  } else {
    override_bit = 0;
  }
  if (SCTP_TSN_GT(tsn, net->cwr_window_tsn) &&
      ((override_bit&SCTP_CWR_REDUCE_OVERRIDE) == 0)) {
    /* JRS - Use the congestion control given in the pluggable CC module */
    stcb->asoc.cc_functions.sctp_cwnd_update_after_ecn_echo(stcb, net, 0, pkt_cnt);
    /*
     * We reduce once every RTT. So we will only lower cwnd at
     * the next sending seq i.e. the window_data_tsn
     */
    net->cwr_window_tsn = window_data_tsn;
    net->ecn_ce_pkt_cnt += pkt_cnt;
    net->lost_cnt = pkt_cnt;
    net->last_cwr_tsn = tsn;
  } else {
    override_bit |= SCTP_CWR_IN_SAME_WINDOW;
    if (SCTP_TSN_GT(tsn, net->last_cwr_tsn) &&
        ((override_bit&SCTP_CWR_REDUCE_OVERRIDE) == 0)) {
      /*
       * Another loss in the same window update how
       * many marks/packets lost we have had.
       */
      int cnt = 1;
      if (pkt_cnt > net->lost_cnt) {
        /* Should be the case */
        cnt = (pkt_cnt - net->lost_cnt);
        net->ecn_ce_pkt_cnt += cnt;
      }
      net->lost_cnt = pkt_cnt;
      net->last_cwr_tsn = tsn;
      /*
       * Most CC functions will ignore this call, since we are in-window
       * yet of the initial CE the peer saw.
       */
      stcb->asoc.cc_functions.sctp_cwnd_update_after_ecn_echo(stcb, net, 1, cnt);
    }
  }
  /*
   * We always send a CWR this way if our previous one was lost our
   * peer will get an update, or if it is not time again to reduce we
   * still get the cwr to the peer. Note we set the override when we
   * could not find the TSN on the chunk or the destination network.
   */
  sctp_send_cwr(stcb, net, net->last_cwr_tsn, override_bit);
}

static void
sctp_handle_ecn_cwr(struct sctp_cwr_chunk *cp, struct sctp_tcb *stcb, struct sctp_nets *net)
{
  /*
   * Here we get a CWR from the peer. We must look in the outqueue and
   * make sure that we have a covered ECNE in the control chunk part.
   * If so remove it.
   */
  struct sctp_tmit_chunk *chk, *nchk;
  struct sctp_ecne_chunk *ecne;
  int override;
  uint32_t cwr_tsn;

  cwr_tsn = ntohl(cp->tsn);
  override = cp->ch.chunk_flags & SCTP_CWR_REDUCE_OVERRIDE;
  TAILQ_FOREACH_SAFE(chk, &stcb->asoc.control_send_queue, sctp_next, nchk) {
    if (chk->rec.chunk_id.id != SCTP_ECN_ECHO) {
      continue;
    }
    if ((override == 0) && (chk->whoTo != net)) {
      /* Must be from the right src unless override is set */
      continue;
    }
    ecne = mtod(chk->data, struct sctp_ecne_chunk *);
    if (SCTP_TSN_GE(cwr_tsn, ntohl(ecne->tsn))) {
      /* this covers this ECNE, we can remove it */
      stcb->asoc.ecn_echo_cnt_onq--;
      TAILQ_REMOVE(&stcb->asoc.control_send_queue, chk,
          sctp_next);
      stcb->asoc.ctrl_queue_cnt--;
      sctp_m_freem(chk->data);
      chk->data = NULL;
      sctp_free_a_chunk(stcb, chk, SCTP_SO_NOT_LOCKED);
      if (override == 0) {
        break;
      }
    }
  }
}

static void
sctp_handle_shutdown_complete(struct sctp_shutdown_complete_chunk *cp SCTP_UNUSED,
    struct sctp_tcb *stcb, struct sctp_nets *net)
{
#if defined(__APPLE__) && !defined(__Userspace__)
  struct socket *so;
#endif

  SCTPDBG(SCTP_DEBUG_INPUT2,
    "sctp_handle_shutdown_complete: handling SHUTDOWN-COMPLETE\n");
  if (stcb == NULL)
    return;

  /* process according to association state */
  if (SCTP_GET_STATE(stcb) != SCTP_STATE_SHUTDOWN_ACK_SENT) {
    /* unexpected SHUTDOWN-COMPLETE... so ignore... */
    SCTPDBG(SCTP_DEBUG_INPUT2,
      "sctp_handle_shutdown_complete: not in SCTP_STATE_SHUTDOWN_ACK_SENT --- ignore\n");
    SCTP_TCB_UNLOCK(stcb);
    return;
  }
  /* notify upper layer protocol */
  if (stcb->sctp_socket) {
    sctp_ulp_notify(SCTP_NOTIFY_ASSOC_DOWN, stcb, 0, NULL, SCTP_SO_NOT_LOCKED);
  }
#ifdef INVARIANTS
  if (!TAILQ_EMPTY(&stcb->asoc.send_queue) ||
      !TAILQ_EMPTY(&stcb->asoc.sent_queue) ||
      sctp_is_there_unsent_data(stcb, SCTP_SO_NOT_LOCKED)) {
    panic("Queues are not empty when handling SHUTDOWN-COMPLETE");
  }
#endif
  /* stop the timer */
  sctp_timer_stop(SCTP_TIMER_TYPE_SHUTDOWNACK, stcb->sctp_ep, stcb, net,
                  SCTP_FROM_SCTP_INPUT + SCTP_LOC_24);
  SCTP_STAT_INCR_COUNTER32(sctps_shutdown);
  /* free the TCB */
  SCTPDBG(SCTP_DEBUG_INPUT2,
    "sctp_handle_shutdown_complete: calls free-asoc\n");
#if defined(__APPLE__) && !defined(__Userspace__)
  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);
#endif
  (void)sctp_free_assoc(stcb->sctp_ep, stcb, SCTP_NORMAL_PROC,
                        SCTP_FROM_SCTP_INPUT + SCTP_LOC_25);
#if defined(__APPLE__) && !defined(__Userspace__)
  SCTP_SOCKET_UNLOCK(so, 1);
#endif
  return;
}

static int
process_chunk_drop(struct sctp_tcb *stcb, struct sctp_chunk_desc *desc,
    struct sctp_nets *net, uint8_t flg)
{
  switch (desc->chunk_type) {
  case SCTP_DATA:
  case SCTP_IDATA:
    /* find the tsn to resend (possibly) */
  {
    uint32_t tsn;
    struct sctp_tmit_chunk *tp1;

    tsn = ntohl(desc->tsn_ifany);
    TAILQ_FOREACH(tp1, &stcb->asoc.sent_queue, sctp_next) {
      if (tp1->rec.data.tsn == tsn) {
        /* found it */
        break;
      }
      if (SCTP_TSN_GT(tp1->rec.data.tsn, tsn)) {
        /* not found */
        tp1 = NULL;
        break;
      }
    }
    if (tp1 == NULL) {
      /*
       * Do it the other way , aka without paying
       * attention to queue seq order.
       */
      SCTP_STAT_INCR(sctps_pdrpdnfnd);
      TAILQ_FOREACH(tp1, &stcb->asoc.sent_queue, sctp_next) {
        if (tp1->rec.data.tsn == tsn) {
          /* found it */
          break;
        }
      }
    }
    if (tp1 == NULL) {
      SCTP_STAT_INCR(sctps_pdrptsnnf);
    }
    if ((tp1) && (tp1->sent < SCTP_DATAGRAM_ACKED)) {
      if (((flg & SCTP_BADCRC) == 0) &&
          ((flg & SCTP_FROM_MIDDLE_BOX) == 0)) {
        return (0);
      }
      if ((stcb->asoc.peers_rwnd == 0) &&
          ((flg & SCTP_FROM_MIDDLE_BOX) == 0)) {
        SCTP_STAT_INCR(sctps_pdrpdiwnp);
        return (0);
      }
      if (stcb->asoc.peers_rwnd == 0 &&
          (flg & SCTP_FROM_MIDDLE_BOX)) {
        SCTP_STAT_INCR(sctps_pdrpdizrw);
        return (0);
      }
      if ((uint32_t)SCTP_BUF_LEN(tp1->data) <
          SCTP_DATA_CHUNK_OVERHEAD(stcb) + SCTP_NUM_DB_TO_VERIFY) {
        /* Payload not matching. */
        SCTP_STAT_INCR(sctps_pdrpbadd);
        return (-1);
      }
      if (memcmp(mtod(tp1->data, caddr_t) + SCTP_DATA_CHUNK_OVERHEAD(stcb),
                 desc->data_bytes, SCTP_NUM_DB_TO_VERIFY) != 0) {
        /* Payload not matching. */
        SCTP_STAT_INCR(sctps_pdrpbadd);
        return (-1);
      }
      if (tp1->do_rtt) {
        /*
         * this guy had a RTO calculation
         * pending on it, cancel it
         */
        if (tp1->whoTo->rto_needed == 0) {
          tp1->whoTo->rto_needed = 1;
        }
        tp1->do_rtt = 0;
      }
      SCTP_STAT_INCR(sctps_pdrpmark);
      if (tp1->sent != SCTP_DATAGRAM_RESEND)
        sctp_ucount_incr(stcb->asoc.sent_queue_retran_cnt);
      /*
       * mark it as if we were doing a FR, since
       * we will be getting gap ack reports behind
       * the info from the router.
       */
      tp1->rec.data.doing_fast_retransmit = 1;
      /*
       * mark the tsn with what sequences can
       * cause a new FR.
       */
      if (TAILQ_EMPTY(&stcb->asoc.send_queue)) {
        tp1->rec.data.fast_retran_tsn = stcb->asoc.sending_seq;
      } else {
        tp1->rec.data.fast_retran_tsn = (TAILQ_FIRST(&stcb->asoc.send_queue))->rec.data.tsn;
      }

      /* restart the timer */
      sctp_timer_stop(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep,
          stcb, tp1->whoTo,
                      SCTP_FROM_SCTP_INPUT + SCTP_LOC_26);
      sctp_timer_start(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep,
           stcb, tp1->whoTo);

      /* fix counts and things */
      if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FLIGHT_LOGGING_ENABLE) {
        sctp_misc_ints(SCTP_FLIGHT_LOG_DOWN_PDRP,
                 tp1->whoTo->flight_size,
                 tp1->book_size,
                 (uint32_t)(uintptr_t)stcb,
                 tp1->rec.data.tsn);
      }
      if (tp1->sent < SCTP_DATAGRAM_RESEND) {
        sctp_flight_size_decrease(tp1);
        sctp_total_flight_decrease(stcb, tp1);
      }
      tp1->sent = SCTP_DATAGRAM_RESEND;
    } {
      /* audit code */
      unsigned int audit;

      audit = 0;
      TAILQ_FOREACH(tp1, &stcb->asoc.sent_queue, sctp_next) {
        if (tp1->sent == SCTP_DATAGRAM_RESEND)
          audit++;
      }
      TAILQ_FOREACH(tp1, &stcb->asoc.control_send_queue,
              sctp_next) {
        if (tp1->sent == SCTP_DATAGRAM_RESEND)
          audit++;
      }
      if (audit != stcb->asoc.sent_queue_retran_cnt) {
        SCTP_PRINTF("**Local Audit finds cnt:%d asoc cnt:%d\n",
              audit, stcb->asoc.sent_queue_retran_cnt);
#ifndef SCTP_AUDITING_ENABLED
        stcb->asoc.sent_queue_retran_cnt = audit;
#endif
      }
    }
  }
  break;
  case SCTP_ASCONF:
  {
    struct sctp_tmit_chunk *asconf;

    TAILQ_FOREACH(asconf, &stcb->asoc.control_send_queue,
            sctp_next) {
      if (asconf->rec.chunk_id.id == SCTP_ASCONF) {
        break;
      }
    }
    if (asconf) {
      if (asconf->sent != SCTP_DATAGRAM_RESEND)
        sctp_ucount_incr(stcb->asoc.sent_queue_retran_cnt);
      asconf->sent = SCTP_DATAGRAM_RESEND;
      asconf->snd_count--;
    }
  }
  break;
  case SCTP_INITIATION:
    /* resend the INIT */
    stcb->asoc.dropped_special_cnt++;
    if (stcb->asoc.dropped_special_cnt < SCTP_RETRY_DROPPED_THRESH) {
      /*
       * If we can get it in, in a few attempts we do
       * this, otherwise we let the timer fire.
       */
      sctp_timer_stop(SCTP_TIMER_TYPE_INIT, stcb->sctp_ep,
          stcb, net,
                      SCTP_FROM_SCTP_INPUT + SCTP_LOC_27);
      sctp_send_initiate(stcb->sctp_ep, stcb, SCTP_SO_NOT_LOCKED);
    }
    break;
  case SCTP_SELECTIVE_ACK:
  case SCTP_NR_SELECTIVE_ACK:
    /* resend the sack */
    sctp_send_sack(stcb, SCTP_SO_NOT_LOCKED);
    break;
  case SCTP_HEARTBEAT_REQUEST:
    /* resend a demand HB */
    if ((stcb->asoc.overall_error_count + 3) < stcb->asoc.max_send_times) {
      /* Only retransmit if we KNOW we wont destroy the tcb */
      sctp_send_hb(stcb, net, SCTP_SO_NOT_LOCKED);
    }
    break;
  case SCTP_SHUTDOWN:
    sctp_send_shutdown(stcb, net);
    break;
  case SCTP_SHUTDOWN_ACK:
    sctp_send_shutdown_ack(stcb, net);
    break;
  case SCTP_COOKIE_ECHO:
  {
    struct sctp_tmit_chunk *cookie;

    cookie = NULL;
    TAILQ_FOREACH(cookie, &stcb->asoc.control_send_queue,
            sctp_next) {
      if (cookie->rec.chunk_id.id == SCTP_COOKIE_ECHO) {
        break;
      }
    }
    if (cookie) {
      if (cookie->sent != SCTP_DATAGRAM_RESEND)
        sctp_ucount_incr(stcb->asoc.sent_queue_retran_cnt);
      cookie->sent = SCTP_DATAGRAM_RESEND;
      sctp_stop_all_cookie_timers(stcb);
    }
  }
  break;
  case SCTP_COOKIE_ACK:
    sctp_send_cookie_ack(stcb);
    break;
  case SCTP_ASCONF_ACK:
    /* resend last asconf ack */
    sctp_send_asconf_ack(stcb);
    break;
  case SCTP_IFORWARD_CUM_TSN:
  case SCTP_FORWARD_CUM_TSN:
    send_forward_tsn(stcb, &stcb->asoc);
    break;
    /* can't do anything with these */
  case SCTP_PACKET_DROPPED:
  case SCTP_INITIATION_ACK: /* this should not happen */
  case SCTP_HEARTBEAT_ACK:
  case SCTP_ABORT_ASSOCIATION:
  case SCTP_OPERATION_ERROR:
  case SCTP_SHUTDOWN_COMPLETE:
  case SCTP_ECN_ECHO:
  case SCTP_ECN_CWR:
  default:
    break;
  }
  return (0);
}

void
sctp_reset_in_stream(struct sctp_tcb *stcb, uint32_t number_entries, uint16_t *list)
{
  uint32_t i;
  uint16_t temp;

  /*
   * We set things to 0xffffffff since this is the last delivered sequence
   * and we will be sending in 0 after the reset.
   */

  if (number_entries) {
    for (i = 0; i < number_entries; i++) {
      temp = ntohs(list[i]);
      if (temp >= stcb->asoc.streamincnt) {
        continue;
      }
      stcb->asoc.strmin[temp].last_mid_delivered = 0xffffffff;
    }
  } else {
    list = NULL;
    for (i = 0; i < stcb->asoc.streamincnt; i++) {
      stcb->asoc.strmin[i].last_mid_delivered = 0xffffffff;
    }
  }
  sctp_ulp_notify(SCTP_NOTIFY_STR_RESET_RECV, stcb, number_entries, (void *)list, SCTP_SO_NOT_LOCKED);
}

static void
sctp_reset_out_streams(struct sctp_tcb *stcb, uint32_t number_entries, uint16_t *list)
{
  uint32_t i;
  uint16_t temp;

  if (number_entries > 0) {
    for (i = 0; i < number_entries; i++) {
      temp = ntohs(list[i]);
      if (temp >= stcb->asoc.streamoutcnt) {
        /* no such stream */
        continue;
      }
      stcb->asoc.strmout[temp].next_mid_ordered = 0;
      stcb->asoc.strmout[temp].next_mid_unordered = 0;
    }
  } else {
    for (i = 0; i < stcb->asoc.streamoutcnt; i++) {
      stcb->asoc.strmout[i].next_mid_ordered = 0;
      stcb->asoc.strmout[i].next_mid_unordered = 0;
    }
  }
  sctp_ulp_notify(SCTP_NOTIFY_STR_RESET_SEND, stcb, number_entries, (void *)list, SCTP_SO_NOT_LOCKED);
}

static void
sctp_reset_clear_pending(struct sctp_tcb *stcb, uint32_t number_entries, uint16_t *list)
{
  uint32_t i;
  uint16_t temp;

  if (number_entries > 0) {
    for (i = 0; i < number_entries; i++) {
      temp = ntohs(list[i]);
      if (temp >= stcb->asoc.streamoutcnt) {
        /* no such stream */
        continue;
      }
      stcb->asoc.strmout[temp].state = SCTP_STREAM_OPEN;
    }
  } else {
    for (i = 0; i < stcb->asoc.streamoutcnt; i++) {
      stcb->asoc.strmout[i].state = SCTP_STREAM_OPEN;
    }
  }
}

struct sctp_stream_reset_request *
sctp_find_stream_reset(struct sctp_tcb *stcb, uint32_t seq, struct sctp_tmit_chunk **bchk)
{
  struct sctp_association *asoc;
  struct sctp_chunkhdr *ch;
  struct sctp_stream_reset_request *r;
  struct sctp_tmit_chunk *chk;
  int len, clen;

  asoc = &stcb->asoc;
  chk = asoc->str_reset;
  if (TAILQ_EMPTY(&asoc->control_send_queue) ||
      (chk == NULL)) {
    asoc->stream_reset_outstanding = 0;
    return (NULL);
  }
  if (chk->data == NULL) {
    return (NULL);
  }
  if (bchk != NULL) {
    /* he wants a copy of the chk pointer */
    *bchk = chk;
  }
  clen = chk->send_size;
  ch = mtod(chk->data, struct sctp_chunkhdr *);
  r = (struct sctp_stream_reset_request *)(ch + 1);
  if (ntohl(r->request_seq) == seq) {
    /* found it */
    return (r);
  }
  len = SCTP_SIZE32(ntohs(r->ph.param_length));
  if (clen > (len + (int)sizeof(struct sctp_chunkhdr))) {
    /* move to the next one, there can only be a max of two */
    r = (struct sctp_stream_reset_request *)((caddr_t)r + len);
    if (ntohl(r->request_seq) == seq) {
      return (r);
    }
  }
  /* that seq is not here */
  return (NULL);
}

static void
sctp_clean_up_stream_reset(struct sctp_tcb *stcb)
{
  struct sctp_association *asoc;
  struct sctp_tmit_chunk *chk;

  asoc = &stcb->asoc;
  chk = asoc->str_reset;
  if (chk == NULL) {
    return;
  }
  asoc->str_reset = NULL;
  sctp_timer_stop(SCTP_TIMER_TYPE_STRRESET, stcb->sctp_ep, stcb,
                  NULL, SCTP_FROM_SCTP_INPUT + SCTP_LOC_28);
  TAILQ_REMOVE(&asoc->control_send_queue, chk, sctp_next);
  asoc->ctrl_queue_cnt--;
  if (chk->data) {
    sctp_m_freem(chk->data);
    chk->data = NULL;
  }
  sctp_free_a_chunk(stcb, chk, SCTP_SO_NOT_LOCKED);
}

static int
sctp_handle_stream_reset_response(struct sctp_tcb *stcb,
          uint32_t seq, uint32_t action,
          struct sctp_stream_reset_response *respin)
{
  uint16_t type;
  int lparam_len;
  struct sctp_association *asoc = &stcb->asoc;
  struct sctp_tmit_chunk *chk;
  struct sctp_stream_reset_request *req_param;
  struct sctp_stream_reset_out_request *req_out_param;
  struct sctp_stream_reset_in_request *req_in_param;
  uint32_t number_entries;

  if (asoc->stream_reset_outstanding == 0) {
    /* duplicate */
    return (0);
  }
  if (seq == stcb->asoc.str_reset_seq_out) {
    req_param = sctp_find_stream_reset(stcb, seq, &chk);
    if (req_param != NULL) {
      stcb->asoc.str_reset_seq_out++;
      type = ntohs(req_param->ph.param_type);
      lparam_len = ntohs(req_param->ph.param_length);
      if (type == SCTP_STR_RESET_OUT_REQUEST) {
        int no_clear = 0;

        req_out_param = (struct sctp_stream_reset_out_request *)req_param;
        number_entries = (lparam_len - sizeof(struct sctp_stream_reset_out_request)) / sizeof(uint16_t);
        asoc->stream_reset_out_is_outstanding = 0;
        if (asoc->stream_reset_outstanding)
          asoc->stream_reset_outstanding--;
        if (action == SCTP_STREAM_RESET_RESULT_PERFORMED) {
          /* do it */
          sctp_reset_out_streams(stcb, number_entries, req_out_param->list_of_streams);
        } else if (action == SCTP_STREAM_RESET_RESULT_DENIED) {
          sctp_ulp_notify(SCTP_NOTIFY_STR_RESET_DENIED_OUT, stcb, number_entries, req_out_param->list_of_streams, SCTP_SO_NOT_LOCKED);
        } else if (action == SCTP_STREAM_RESET_RESULT_IN_PROGRESS) {
          /* Set it up so we don't stop retransmitting */
          asoc->stream_reset_outstanding++;
          stcb->asoc.str_reset_seq_out--;
          asoc->stream_reset_out_is_outstanding = 1;
          no_clear = 1;
        } else {
          sctp_ulp_notify(SCTP_NOTIFY_STR_RESET_FAILED_OUT, stcb, number_entries, req_out_param->list_of_streams, SCTP_SO_NOT_LOCKED);
        }
        if (no_clear == 0) {
          sctp_reset_clear_pending(stcb, number_entries, req_out_param->list_of_streams);
        }
      } else if (type == SCTP_STR_RESET_IN_REQUEST) {
        req_in_param = (struct sctp_stream_reset_in_request *)req_param;
        number_entries = (lparam_len - sizeof(struct sctp_stream_reset_in_request)) / sizeof(uint16_t);
        if (asoc->stream_reset_outstanding)
          asoc->stream_reset_outstanding--;
        if (action == SCTP_STREAM_RESET_RESULT_DENIED) {
          sctp_ulp_notify(SCTP_NOTIFY_STR_RESET_DENIED_IN, stcb,
              number_entries, req_in_param->list_of_streams, SCTP_SO_NOT_LOCKED);
        } else if (action != SCTP_STREAM_RESET_RESULT_PERFORMED) {
          sctp_ulp_notify(SCTP_NOTIFY_STR_RESET_FAILED_IN, stcb,
              number_entries, req_in_param->list_of_streams, SCTP_SO_NOT_LOCKED);
        }
      } else if (type == SCTP_STR_RESET_ADD_OUT_STREAMS) {
        /* Ok we now may have more streams */
        int num_stream;

        num_stream = stcb->asoc.strm_pending_add_size;
        if (num_stream > (stcb->asoc.strm_realoutsize - stcb->asoc.streamoutcnt)) {
          /* TSNH */
          num_stream = stcb->asoc.strm_realoutsize - stcb->asoc.streamoutcnt;
        }
        stcb->asoc.strm_pending_add_size = 0;
        if (asoc->stream_reset_outstanding)
          asoc->stream_reset_outstanding--;
        if (action == SCTP_STREAM_RESET_RESULT_PERFORMED) {
          /* Put the new streams into effect */
          int i;
          for (i = asoc->streamoutcnt; i < (asoc->streamoutcnt + num_stream); i++) {
            asoc->strmout[i].state = SCTP_STREAM_OPEN;
          }
          asoc->streamoutcnt += num_stream;
          sctp_ulp_notify(SCTP_NOTIFY_STR_RESET_ADD, stcb, 0, NULL, SCTP_SO_NOT_LOCKED);
        } else if (action == SCTP_STREAM_RESET_RESULT_DENIED) {
          sctp_ulp_notify(SCTP_NOTIFY_STR_RESET_ADD, stcb, SCTP_STREAM_CHANGE_DENIED, NULL, SCTP_SO_NOT_LOCKED);
        } else {
          sctp_ulp_notify(SCTP_NOTIFY_STR_RESET_ADD, stcb, SCTP_STREAM_CHANGE_FAILED, NULL, SCTP_SO_NOT_LOCKED);
        }
      } else if (type == SCTP_STR_RESET_ADD_IN_STREAMS) {
        if (asoc->stream_reset_outstanding)
          asoc->stream_reset_outstanding--;
        if (action == SCTP_STREAM_RESET_RESULT_DENIED) {
          sctp_ulp_notify(SCTP_NOTIFY_STR_RESET_ADD, stcb, SCTP_STREAM_CHANGE_DENIED, NULL, SCTP_SO_NOT_LOCKED);
        } else if (action != SCTP_STREAM_RESET_RESULT_PERFORMED) {
          sctp_ulp_notify(SCTP_NOTIFY_STR_RESET_ADD, stcb, SCTP_STREAM_CHANGE_DENIED, NULL, SCTP_SO_NOT_LOCKED);
        }
      } else if (type == SCTP_STR_RESET_TSN_REQUEST) {
        /**
         * a) Adopt the new in tsn.
         * b) reset the map
         * c) Adopt the new out-tsn
         */
        struct sctp_stream_reset_response_tsn *resp;
        struct sctp_forward_tsn_chunk fwdtsn;
        int abort_flag = 0;
        if (respin == NULL) {
          /* huh ? */
          return (0);
        }
        if (ntohs(respin->ph.param_length) < sizeof(struct sctp_stream_reset_response_tsn)) {
          return (0);
        }
        if (action == SCTP_STREAM_RESET_RESULT_PERFORMED) {
          resp = (struct sctp_stream_reset_response_tsn *)respin;
          asoc->stream_reset_outstanding--;
          fwdtsn.ch.chunk_length = htons(sizeof(struct sctp_forward_tsn_chunk));
          fwdtsn.ch.chunk_type = SCTP_FORWARD_CUM_TSN;
          fwdtsn.new_cumulative_tsn = htonl(ntohl(resp->senders_next_tsn) - 1);
          sctp_handle_forward_tsn(stcb, &fwdtsn, &abort_flag, NULL, 0);
          if (abort_flag) {
            return (1);
          }
          stcb->asoc.highest_tsn_inside_map = (ntohl(resp->senders_next_tsn) - 1);
          if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_MAP_LOGGING_ENABLE) {
            sctp_log_map(0, 7, asoc->highest_tsn_inside_map, SCTP_MAP_SLIDE_RESULT);
          }

          stcb->asoc.tsn_last_delivered = stcb->asoc.cumulative_tsn = stcb->asoc.highest_tsn_inside_map;
          stcb->asoc.mapping_array_base_tsn = ntohl(resp->senders_next_tsn);
          memset(stcb->asoc.mapping_array, 0, stcb->asoc.mapping_array_size);

          stcb->asoc.highest_tsn_inside_nr_map = stcb->asoc.highest_tsn_inside_map;
          memset(stcb->asoc.nr_mapping_array, 0, stcb->asoc.mapping_array_size);

          stcb->asoc.sending_seq = ntohl(resp->receivers_next_tsn);
          stcb->asoc.last_acked_seq = stcb->asoc.cumulative_tsn;

          sctp_reset_out_streams(stcb, 0, (uint16_t *) NULL);
          sctp_reset_in_stream(stcb, 0, (uint16_t *) NULL);
          sctp_ulp_notify(SCTP_NOTIFY_STR_RESET_TSN, stcb, 0, NULL, SCTP_SO_NOT_LOCKED);
        } else if (action == SCTP_STREAM_RESET_RESULT_DENIED) {
          sctp_ulp_notify(SCTP_NOTIFY_STR_RESET_TSN, stcb, SCTP_ASSOC_RESET_DENIED, NULL, SCTP_SO_NOT_LOCKED);
        } else {
          sctp_ulp_notify(SCTP_NOTIFY_STR_RESET_TSN, stcb, SCTP_ASSOC_RESET_FAILED, NULL, SCTP_SO_NOT_LOCKED);
        }
      }
      /* get rid of the request and get the request flags */
      if (asoc->stream_reset_outstanding == 0) {
        sctp_clean_up_stream_reset(stcb);
      }
    }
  }
  if (asoc->stream_reset_outstanding == 0) {
    sctp_send_stream_reset_out_if_possible(stcb, SCTP_SO_NOT_LOCKED);
  }
  return (0);
}

static void
sctp_handle_str_reset_request_in(struct sctp_tcb *stcb,
    struct sctp_tmit_chunk *chk,
    struct sctp_stream_reset_in_request *req, int trunc)
{
  uint32_t seq;
  int len, i;
  int number_entries;
  uint16_t temp;

  /*
   * peer wants me to send a str-reset to him for my outgoing seq's if
   * seq_in is right.
   */
  struct sctp_association *asoc = &stcb->asoc;

  seq = ntohl(req->request_seq);
  if (asoc->str_reset_seq_in == seq) {
    asoc->last_reset_action[1] = asoc->last_reset_action[0];
    if ((asoc->local_strreset_support & SCTP_ENABLE_RESET_STREAM_REQ) == 0) {
      asoc->last_reset_action[0] = SCTP_STREAM_RESET_RESULT_DENIED;
    } else if (trunc) {
      /* Can't do it, since they exceeded our buffer size  */
      asoc->last_reset_action[0] = SCTP_STREAM_RESET_RESULT_DENIED;
    } else if (stcb->asoc.stream_reset_out_is_outstanding == 0) {
      len = ntohs(req->ph.param_length);
      number_entries = ((len - sizeof(struct sctp_stream_reset_in_request)) / sizeof(uint16_t));
      if (number_entries) {
        for (i = 0; i < number_entries; i++) {
          temp = ntohs(req->list_of_streams[i]);
          if (temp >= stcb->asoc.streamoutcnt) {
            asoc->last_reset_action[0] = SCTP_STREAM_RESET_RESULT_DENIED;
            goto bad_boy;
          }
          req->list_of_streams[i] = temp;
        }
        for (i = 0; i < number_entries; i++) {
          if (stcb->asoc.strmout[req->list_of_streams[i]].state == SCTP_STREAM_OPEN) {
            stcb->asoc.strmout[req->list_of_streams[i]].state = SCTP_STREAM_RESET_PENDING;
          }
        }
      } else {
        /* Its all */
        for (i = 0; i < stcb->asoc.streamoutcnt; i++) {
          if (stcb->asoc.strmout[i].state == SCTP_STREAM_OPEN)
            stcb->asoc.strmout[i].state = SCTP_STREAM_RESET_PENDING;
        }
      }
      asoc->last_reset_action[0] = SCTP_STREAM_RESET_RESULT_PERFORMED;
    } else {
      /* Can't do it, since we have sent one out */
      asoc->last_reset_action[0] = SCTP_STREAM_RESET_RESULT_ERR_IN_PROGRESS;
    }
  bad_boy:
    sctp_add_stream_reset_result(chk, seq, asoc->last_reset_action[0]);
    asoc->str_reset_seq_in++;
  } else if (asoc->str_reset_seq_in - 1 == seq) {
    sctp_add_stream_reset_result(chk, seq, asoc->last_reset_action[0]);
  } else if (asoc->str_reset_seq_in - 2 == seq) {
    sctp_add_stream_reset_result(chk, seq, asoc->last_reset_action[1]);
  } else {
    sctp_add_stream_reset_result(chk, seq, SCTP_STREAM_RESET_RESULT_ERR_BAD_SEQNO);
  }
  sctp_send_stream_reset_out_if_possible(stcb, SCTP_SO_NOT_LOCKED);
}

static int
sctp_handle_str_reset_request_tsn(struct sctp_tcb *stcb,
    struct sctp_tmit_chunk *chk,
    struct sctp_stream_reset_tsn_request *req)
{
  /* reset all in and out and update the tsn */
  /*
   * A) reset my str-seq's on in and out. B) Select a receive next,
   * and set cum-ack to it. Also process this selected number as a
   * fwd-tsn as well. C) set in the response my next sending seq.
   */
  struct sctp_forward_tsn_chunk fwdtsn;
  struct sctp_association *asoc = &stcb->asoc;
  int abort_flag = 0;
  uint32_t seq;

  seq = ntohl(req->request_seq);
  if (asoc->str_reset_seq_in == seq) {
    asoc->last_reset_action[1] = stcb->asoc.last_reset_action[0];
    if ((asoc->local_strreset_support & SCTP_ENABLE_CHANGE_ASSOC_REQ) == 0) {
      asoc->last_reset_action[0] = SCTP_STREAM_RESET_RESULT_DENIED;
    } else {
      fwdtsn.ch.chunk_length = htons(sizeof(struct sctp_forward_tsn_chunk));
      fwdtsn.ch.chunk_type = SCTP_FORWARD_CUM_TSN;
      fwdtsn.ch.chunk_flags = 0;
      fwdtsn.new_cumulative_tsn = htonl(stcb->asoc.highest_tsn_inside_map + 1);
      sctp_handle_forward_tsn(stcb, &fwdtsn, &abort_flag, NULL, 0);
      if (abort_flag) {
        return (1);
      }
      asoc->highest_tsn_inside_map += SCTP_STREAM_RESET_TSN_DELTA;
      if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_MAP_LOGGING_ENABLE) {
        sctp_log_map(0, 10, asoc->highest_tsn_inside_map, SCTP_MAP_SLIDE_RESULT);
      }
      asoc->tsn_last_delivered = asoc->cumulative_tsn = asoc->highest_tsn_inside_map;
      asoc->mapping_array_base_tsn = asoc->highest_tsn_inside_map + 1;
      memset(asoc->mapping_array, 0, asoc->mapping_array_size);
      asoc->highest_tsn_inside_nr_map = asoc->highest_tsn_inside_map;
      memset(asoc->nr_mapping_array, 0, asoc->mapping_array_size);
      atomic_add_int(&asoc->sending_seq, 1);
      /* save off historical data for retrans */
      asoc->last_sending_seq[1] = asoc->last_sending_seq[0];
      asoc->last_sending_seq[0] = asoc->sending_seq;
      asoc->last_base_tsnsent[1] = asoc->last_base_tsnsent[0];
      asoc->last_base_tsnsent[0] = asoc->mapping_array_base_tsn;
      sctp_reset_out_streams(stcb, 0, (uint16_t *) NULL);
      sctp_reset_in_stream(stcb, 0, (uint16_t *) NULL);
      asoc->last_reset_action[0] = SCTP_STREAM_RESET_RESULT_PERFORMED;
      sctp_ulp_notify(SCTP_NOTIFY_STR_RESET_TSN, stcb, 0, NULL, SCTP_SO_NOT_LOCKED);
    }
    sctp_add_stream_reset_result_tsn(chk, seq, asoc->last_reset_action[0],
                                     asoc->last_sending_seq[0], asoc->last_base_tsnsent[0]);
    asoc->str_reset_seq_in++;
  } else if (asoc->str_reset_seq_in - 1 == seq) {
    sctp_add_stream_reset_result_tsn(chk, seq, asoc->last_reset_action[0],
                                     asoc->last_sending_seq[0], asoc->last_base_tsnsent[0]);
  } else if (asoc->str_reset_seq_in - 2 == seq) {
    sctp_add_stream_reset_result_tsn(chk, seq, asoc->last_reset_action[1],
                                     asoc->last_sending_seq[1], asoc->last_base_tsnsent[1]);
  } else {
    sctp_add_stream_reset_result(chk, seq, SCTP_STREAM_RESET_RESULT_ERR_BAD_SEQNO);
  }
  return (0);
}

static void
sctp_handle_str_reset_request_out(struct sctp_tcb *stcb,
    struct sctp_tmit_chunk *chk,
    struct sctp_stream_reset_out_request *req, int trunc)
{
  uint32_t seq, tsn;
  int number_entries, len;
  struct sctp_association *asoc = &stcb->asoc;

  seq = ntohl(req->request_seq);

  /* now if its not a duplicate we process it */
  if (asoc->str_reset_seq_in == seq) {
    len = ntohs(req->ph.param_length);
    number_entries = ((len - sizeof(struct sctp_stream_reset_out_request)) / sizeof(uint16_t));
    /*
     * the sender is resetting, handle the list issue.. we must
     * a) verify if we can do the reset, if so no problem b) If
     * we can't do the reset we must copy the request. c) queue
     * it, and setup the data in processor to trigger it off
     * when needed and dequeue all the queued data.
     */
    tsn = ntohl(req->send_reset_at_tsn);

    /* move the reset action back one */
    asoc->last_reset_action[1] = asoc->last_reset_action[0];
    if ((asoc->local_strreset_support & SCTP_ENABLE_RESET_STREAM_REQ) == 0) {
      asoc->last_reset_action[0] = SCTP_STREAM_RESET_RESULT_DENIED;
    } else if (trunc) {
      asoc->last_reset_action[0] = SCTP_STREAM_RESET_RESULT_DENIED;
    } else if (SCTP_TSN_GE(asoc->cumulative_tsn, tsn)) {
      /* we can do it now */
      sctp_reset_in_stream(stcb, number_entries, req->list_of_streams);
      asoc->last_reset_action[0] = SCTP_STREAM_RESET_RESULT_PERFORMED;
    } else {
      /*
       * we must queue it up and thus wait for the TSN's
       * to arrive that are at or before tsn
       */
      struct sctp_stream_reset_list *liste;
      int siz;

      siz = sizeof(struct sctp_stream_reset_list) + (number_entries * sizeof(uint16_t));
      SCTP_MALLOC(liste, struct sctp_stream_reset_list *,
            siz, SCTP_M_STRESET);
      if (liste == NULL) {
        /* gak out of memory */
        asoc->last_reset_action[0] = SCTP_STREAM_RESET_RESULT_DENIED;
        sctp_add_stream_reset_result(chk, seq, asoc->last_reset_action[0]);
        return;
      }
      liste->seq = seq;
      liste->tsn = tsn;
      liste->number_entries = number_entries;
      memcpy(&liste->list_of_streams, req->list_of_streams, number_entries * sizeof(uint16_t));
      TAILQ_INSERT_TAIL(&asoc->resetHead, liste, next_resp);
      asoc->last_reset_action[0] = SCTP_STREAM_RESET_RESULT_IN_PROGRESS;
    }
    sctp_add_stream_reset_result(chk, seq, asoc->last_reset_action[0]);
    asoc->str_reset_seq_in++;
  } else if ((asoc->str_reset_seq_in - 1) == seq) {
    /*
     * one seq back, just echo back last action since my
     * response was lost.
     */
    sctp_add_stream_reset_result(chk, seq, asoc->last_reset_action[0]);
  } else if ((asoc->str_reset_seq_in - 2) == seq) {
    /*
     * two seq back, just echo back last action since my
     * response was lost.
     */
    sctp_add_stream_reset_result(chk, seq, asoc->last_reset_action[1]);
  } else {
    sctp_add_stream_reset_result(chk, seq, SCTP_STREAM_RESET_RESULT_ERR_BAD_SEQNO);
  }
}

static void
sctp_handle_str_reset_add_strm(struct sctp_tcb *stcb, struct sctp_tmit_chunk *chk,
             struct sctp_stream_reset_add_strm  *str_add)
{
  /*
   * Peer is requesting to add more streams.
   * If its within our max-streams we will
   * allow it.
   */
  uint32_t num_stream, i;
  uint32_t seq;
  struct sctp_association *asoc = &stcb->asoc;
  struct sctp_queued_to_read *ctl, *nctl;

  /* Get the number. */
  seq = ntohl(str_add->request_seq);
  num_stream = ntohs(str_add->number_of_streams);
  /* Now what would be the new total? */
  if (asoc->str_reset_seq_in == seq) {
    num_stream += stcb->asoc.streamincnt;
    stcb->asoc.last_reset_action[1] = stcb->asoc.last_reset_action[0];
    if ((asoc->local_strreset_support & SCTP_ENABLE_CHANGE_ASSOC_REQ) == 0) {
      asoc->last_reset_action[0] = SCTP_STREAM_RESET_RESULT_DENIED;
    } else if ((num_stream > stcb->asoc.max_inbound_streams) ||
               (num_stream > 0xffff)) {
      /* We must reject it they ask for to many */
  denied:
      stcb->asoc.last_reset_action[0] = SCTP_STREAM_RESET_RESULT_DENIED;
    } else {
      /* Ok, we can do that :-) */
      struct sctp_stream_in *oldstrm;

      /* save off the old */
      oldstrm = stcb->asoc.strmin;
      SCTP_MALLOC(stcb->asoc.strmin, struct sctp_stream_in *,
                  (num_stream * sizeof(struct sctp_stream_in)),
                  SCTP_M_STRMI);
      if (stcb->asoc.strmin == NULL) {
        stcb->asoc.strmin = oldstrm;
        goto denied;
      }
      /* copy off the old data */
      for (i = 0; i < stcb->asoc.streamincnt; i++) {
        TAILQ_INIT(&stcb->asoc.strmin[i].inqueue);
        TAILQ_INIT(&stcb->asoc.strmin[i].uno_inqueue);
        stcb->asoc.strmin[i].sid = i;
        stcb->asoc.strmin[i].last_mid_delivered = oldstrm[i].last_mid_delivered;
        stcb->asoc.strmin[i].delivery_started = oldstrm[i].delivery_started;
        stcb->asoc.strmin[i].pd_api_started = oldstrm[i].pd_api_started;
        /* now anything on those queues? */
        TAILQ_FOREACH_SAFE(ctl, &oldstrm[i].inqueue, next_instrm, nctl) {
          TAILQ_REMOVE(&oldstrm[i].inqueue, ctl, next_instrm);
          TAILQ_INSERT_TAIL(&stcb->asoc.strmin[i].inqueue, ctl, next_instrm);
        }
        TAILQ_FOREACH_SAFE(ctl, &oldstrm[i].uno_inqueue, next_instrm, nctl) {
          TAILQ_REMOVE(&oldstrm[i].uno_inqueue, ctl, next_instrm);
          TAILQ_INSERT_TAIL(&stcb->asoc.strmin[i].uno_inqueue, ctl, next_instrm);
        }
      }
      /* Init the new streams */
      for (i = stcb->asoc.streamincnt; i < num_stream; i++) {
        TAILQ_INIT(&stcb->asoc.strmin[i].inqueue);
        TAILQ_INIT(&stcb->asoc.strmin[i].uno_inqueue);
        stcb->asoc.strmin[i].sid = i;
        stcb->asoc.strmin[i].last_mid_delivered = 0xffffffff;
        stcb->asoc.strmin[i].pd_api_started = 0;
        stcb->asoc.strmin[i].delivery_started = 0;
      }
      SCTP_FREE(oldstrm, SCTP_M_STRMI);
      /* update the size */
      stcb->asoc.streamincnt = num_stream;
      stcb->asoc.last_reset_action[0] = SCTP_STREAM_RESET_RESULT_PERFORMED;
      sctp_ulp_notify(SCTP_NOTIFY_STR_RESET_ADD, stcb, 0, NULL, SCTP_SO_NOT_LOCKED);
    }
    sctp_add_stream_reset_result(chk, seq, asoc->last_reset_action[0]);
    asoc->str_reset_seq_in++;
  } else if ((asoc->str_reset_seq_in - 1) == seq) {
    /*
     * one seq back, just echo back last action since my
     * response was lost.
     */
    sctp_add_stream_reset_result(chk, seq, asoc->last_reset_action[0]);
  } else if ((asoc->str_reset_seq_in - 2) == seq) {
    /*
     * two seq back, just echo back last action since my
     * response was lost.
     */
    sctp_add_stream_reset_result(chk, seq, asoc->last_reset_action[1]);
  } else {
    sctp_add_stream_reset_result(chk, seq, SCTP_STREAM_RESET_RESULT_ERR_BAD_SEQNO);
  }
}

static void
sctp_handle_str_reset_add_out_strm(struct sctp_tcb *stcb, struct sctp_tmit_chunk *chk,
           struct sctp_stream_reset_add_strm  *str_add)
{
  /*
   * Peer is requesting to add more streams.
   * If its within our max-streams we will
   * allow it.
   */
  uint16_t num_stream;
  uint32_t seq;
  struct sctp_association *asoc = &stcb->asoc;

  /* Get the number. */
  seq = ntohl(str_add->request_seq);
  num_stream = ntohs(str_add->number_of_streams);
  /* Now what would be the new total? */
  if (asoc->str_reset_seq_in == seq) {
    stcb->asoc.last_reset_action[1] = stcb->asoc.last_reset_action[0];
    if ((asoc->local_strreset_support & SCTP_ENABLE_CHANGE_ASSOC_REQ) == 0) {
      asoc->last_reset_action[0] = SCTP_STREAM_RESET_RESULT_DENIED;
    } else if (stcb->asoc.stream_reset_outstanding) {
      /* We must reject it we have something pending */
      stcb->asoc.last_reset_action[0] = SCTP_STREAM_RESET_RESULT_ERR_IN_PROGRESS;
    } else {
      /* Ok, we can do that :-) */
      int mychk;
      mychk = stcb->asoc.streamoutcnt;
      mychk += num_stream;
      if (mychk < 0x10000) {
        stcb->asoc.last_reset_action[0] = SCTP_STREAM_RESET_RESULT_PERFORMED;
        if (sctp_send_str_reset_req(stcb, 0, NULL, 0, 0, 1, num_stream, 0, 1)) {
          stcb->asoc.last_reset_action[0] = SCTP_STREAM_RESET_RESULT_DENIED;
        }
      } else {
        stcb->asoc.last_reset_action[0] = SCTP_STREAM_RESET_RESULT_DENIED;
      }
    }
    sctp_add_stream_reset_result(chk, seq, stcb->asoc.last_reset_action[0]);
    asoc->str_reset_seq_in++;
  } else if ((asoc->str_reset_seq_in - 1) == seq) {
    /*
     * one seq back, just echo back last action since my
     * response was lost.
     */
    sctp_add_stream_reset_result(chk, seq, asoc->last_reset_action[0]);
  } else if ((asoc->str_reset_seq_in - 2) == seq) {
    /*
     * two seq back, just echo back last action since my
     * response was lost.
     */
    sctp_add_stream_reset_result(chk, seq, asoc->last_reset_action[1]);
  } else {
    sctp_add_stream_reset_result(chk, seq, SCTP_STREAM_RESET_RESULT_ERR_BAD_SEQNO);
  }
}

#ifdef __GNUC__
__attribute__ ((noinline))
#endif
static int
sctp_handle_stream_reset(struct sctp_tcb *stcb, struct mbuf *m, int offset,
       struct sctp_chunkhdr *ch_req)
{
  uint16_t remaining_length, param_len, ptype;
  struct sctp_paramhdr pstore;
  uint8_t cstore[SCTP_CHUNK_BUFFER_SIZE];
  uint32_t seq = 0;
  int num_req = 0;
  int trunc = 0;
  struct sctp_tmit_chunk *chk;
  struct sctp_chunkhdr *ch;
  struct sctp_paramhdr *ph;
  int ret_code = 0;
  int num_param = 0;

  /* now it may be a reset or a reset-response */
  remaining_length = ntohs(ch_req->chunk_length) - sizeof(struct sctp_chunkhdr);

  /* setup for adding the response */
  sctp_alloc_a_chunk(stcb, chk);
  if (chk == NULL) {
    return (ret_code);
  }
  chk->copy_by_ref = 0;
  chk->rec.chunk_id.id = SCTP_STREAM_RESET;
  chk->rec.chunk_id.can_take_data = 0;
  chk->flags = 0;
  chk->asoc = &stcb->asoc;
  chk->no_fr_allowed = 0;
  chk->book_size = chk->send_size = sizeof(struct sctp_chunkhdr);
  chk->book_size_scale = 0;
  chk->data = sctp_get_mbuf_for_msg(MCLBYTES, 0, M_NOWAIT, 1, MT_DATA);
  if (chk->data == NULL) {
  strres_nochunk:
    if (chk->data) {
      sctp_m_freem(chk->data);
      chk->data = NULL;
    }
    sctp_free_a_chunk(stcb, chk, SCTP_SO_NOT_LOCKED);
    return (ret_code);
  }
  SCTP_BUF_RESV_UF(chk->data, SCTP_MIN_OVERHEAD);

  /* setup chunk parameters */
  chk->sent = SCTP_DATAGRAM_UNSENT;
  chk->snd_count = 0;
  chk->whoTo = NULL;

  ch = mtod(chk->data, struct sctp_chunkhdr *);
  ch->chunk_type = SCTP_STREAM_RESET;
  ch->chunk_flags = 0;
  ch->chunk_length = htons(chk->send_size);
  SCTP_BUF_LEN(chk->data) = SCTP_SIZE32(chk->send_size);
  offset += sizeof(struct sctp_chunkhdr);
  while (remaining_length >= sizeof(struct sctp_paramhdr)) {
    ph = (struct sctp_paramhdr *)sctp_m_getptr(m, offset, sizeof(pstore), (uint8_t *)&pstore);
    if (ph == NULL) {
      /* TSNH */
      break;
    }
    param_len = ntohs(ph->param_length);
    if ((param_len > remaining_length) ||
        (param_len < (sizeof(struct sctp_paramhdr) + sizeof(uint32_t)))) {
      /* bad parameter length */
      break;
    }
    ph = (struct sctp_paramhdr *)sctp_m_getptr(m, offset, min(param_len, sizeof(cstore)),
                 (uint8_t *)&cstore);
    if (ph == NULL) {
      /* TSNH */
      break;
    }
    ptype = ntohs(ph->param_type);
    num_param++;
    if (param_len > sizeof(cstore)) {
      trunc = 1;
    } else {
      trunc = 0;
    }
    if (num_param > SCTP_MAX_RESET_PARAMS) {
      /* hit the max of parameters already sorry.. */
      break;
    }
    if (ptype == SCTP_STR_RESET_OUT_REQUEST) {
      struct sctp_stream_reset_out_request *req_out;

      if (param_len < sizeof(struct sctp_stream_reset_out_request)) {
        break;
      }
      req_out = (struct sctp_stream_reset_out_request *)ph;
      num_req++;
      if (stcb->asoc.stream_reset_outstanding) {
        seq = ntohl(req_out->response_seq);
        if (seq == stcb->asoc.str_reset_seq_out) {
          /* implicit ack */
          (void)sctp_handle_stream_reset_response(stcb, seq, SCTP_STREAM_RESET_RESULT_PERFORMED, NULL);
        }
      }
      sctp_handle_str_reset_request_out(stcb, chk, req_out, trunc);
    } else if (ptype == SCTP_STR_RESET_ADD_OUT_STREAMS) {
      struct sctp_stream_reset_add_strm  *str_add;

      if (param_len < sizeof(struct sctp_stream_reset_add_strm)) {
        break;
      }
      str_add = (struct sctp_stream_reset_add_strm  *)ph;
      num_req++;
      sctp_handle_str_reset_add_strm(stcb, chk, str_add);
    } else if (ptype == SCTP_STR_RESET_ADD_IN_STREAMS) {
      struct sctp_stream_reset_add_strm  *str_add;

      if (param_len < sizeof(struct sctp_stream_reset_add_strm)) {
        break;
      }
      str_add = (struct sctp_stream_reset_add_strm  *)ph;
      num_req++;
      sctp_handle_str_reset_add_out_strm(stcb, chk, str_add);
    } else if (ptype == SCTP_STR_RESET_IN_REQUEST) {
      struct sctp_stream_reset_in_request *req_in;

      num_req++;
      req_in = (struct sctp_stream_reset_in_request *)ph;
      sctp_handle_str_reset_request_in(stcb, chk, req_in, trunc);
    } else if (ptype == SCTP_STR_RESET_TSN_REQUEST) {
      struct sctp_stream_reset_tsn_request *req_tsn;

      num_req++;
      req_tsn = (struct sctp_stream_reset_tsn_request *)ph;
      if (sctp_handle_str_reset_request_tsn(stcb, chk, req_tsn)) {
        ret_code = 1;
        goto strres_nochunk;
      }
      /* no more */
      break;
    } else if (ptype == SCTP_STR_RESET_RESPONSE) {
      struct sctp_stream_reset_response *resp;
      uint32_t result;

      if (param_len < sizeof(struct sctp_stream_reset_response)) {
        break;
      }
      resp = (struct sctp_stream_reset_response *)ph;
      seq = ntohl(resp->response_seq);
      result = ntohl(resp->result);
      if (sctp_handle_stream_reset_response(stcb, seq, result, resp)) {
        ret_code = 1;
        goto strres_nochunk;
      }
    } else {
      break;
    }
    offset += SCTP_SIZE32(param_len);
    if (remaining_length >= SCTP_SIZE32(param_len)) {
      remaining_length -= SCTP_SIZE32(param_len);
    } else {
      remaining_length = 0;
    }
  }
  if (num_req == 0) {
    /* we have no response free the stuff */
    goto strres_nochunk;
  }
  /* ok we have a chunk to link in */
  TAILQ_INSERT_TAIL(&stcb->asoc.control_send_queue,
        chk,
        sctp_next);
  stcb->asoc.ctrl_queue_cnt++;
  return (ret_code);
}

/*
 * Handle a router or endpoints report of a packet loss, there are two ways
 * to handle this, either we get the whole packet and must disect it
 * ourselves (possibly with truncation and or corruption) or it is a summary
 * from a middle box that did the disecting for us.
 */
static void
sctp_handle_packet_dropped(struct sctp_pktdrop_chunk *cp,
    struct sctp_tcb *stcb, struct sctp_nets *net, uint32_t limit)
{
  struct sctp_chunk_desc desc;
  struct sctp_chunkhdr *chk_hdr;
  struct sctp_data_chunk *data_chunk;
  struct sctp_idata_chunk *idata_chunk;
  uint32_t bottle_bw, on_queue;
  uint32_t offset, chk_len;
  uint16_t pktdrp_len;
  uint8_t pktdrp_flags;

  KASSERT(sizeof(struct sctp_pktdrop_chunk) <= limit,
          ("PKTDROP chunk too small"));
  pktdrp_flags = cp->ch.chunk_flags;
  pktdrp_len = ntohs(cp->ch.chunk_length);
  KASSERT(limit <= pktdrp_len, ("Inconsistent limit"));
  if (pktdrp_flags & SCTP_PACKET_TRUNCATED) {
    if (ntohs(cp->trunc_len) <= pktdrp_len - sizeof(struct sctp_pktdrop_chunk)) {
      /* The peer plays games with us. */
      return;
    }
  }
  limit -= sizeof(struct sctp_pktdrop_chunk);
  offset = 0;
  if (offset == limit) {
    if (pktdrp_flags & SCTP_FROM_MIDDLE_BOX) {
      SCTP_STAT_INCR(sctps_pdrpbwrpt);
    }
  } else if (offset + sizeof(struct sctphdr) > limit) {
    /* Only a partial SCTP common header. */
    SCTP_STAT_INCR(sctps_pdrpcrupt);
    offset = limit;
  } else {
    /* XXX: Check embedded SCTP common header. */
    offset += sizeof(struct sctphdr);
  }
  /* Now parse through the chunks themselves. */
  while (offset < limit) {
    if (offset + sizeof(struct sctp_chunkhdr) > limit) {
      SCTP_STAT_INCR(sctps_pdrpcrupt);
      break;
    }
    chk_hdr = (struct sctp_chunkhdr *)(cp->data + offset);
    desc.chunk_type = chk_hdr->chunk_type;
    /* get amount we need to move */
    chk_len = (uint32_t)ntohs(chk_hdr->chunk_length);
    if (chk_len < sizeof(struct sctp_chunkhdr)) {
      /* Someone is lying... */
      break;
    }
    if (desc.chunk_type == SCTP_DATA) {
      if (stcb->asoc.idata_supported) {
        /* Some is playing games with us. */
        break;
      }
      if (chk_len <= sizeof(struct sctp_data_chunk)) {
        /* Some is playing games with us. */
        break;
      }
      if (chk_len < sizeof(struct sctp_data_chunk) + SCTP_NUM_DB_TO_VERIFY) {
        /* Not enough data bytes available in the chunk. */
        SCTP_STAT_INCR(sctps_pdrpnedat);
        goto next_chunk;
      }
      if (offset + sizeof(struct sctp_data_chunk) + SCTP_NUM_DB_TO_VERIFY > limit) {
        /* Not enough data in buffer. */
        break;
      }
      data_chunk = (struct sctp_data_chunk *)(cp->data + offset);
      memcpy(desc.data_bytes, data_chunk + 1, SCTP_NUM_DB_TO_VERIFY);
      desc.tsn_ifany = data_chunk->dp.tsn;
      if (pktdrp_flags & SCTP_FROM_MIDDLE_BOX) {
        SCTP_STAT_INCR(sctps_pdrpmbda);
      }
    } else if (desc.chunk_type == SCTP_IDATA) {
      if (!stcb->asoc.idata_supported) {
        /* Some is playing games with us. */
        break;
      }
      if (chk_len <= sizeof(struct sctp_idata_chunk)) {
        /* Some is playing games with us. */
        break;
      }
      if (chk_len < sizeof(struct sctp_idata_chunk) + SCTP_NUM_DB_TO_VERIFY) {
        /* Not enough data bytes available in the chunk. */
        SCTP_STAT_INCR(sctps_pdrpnedat);
        goto next_chunk;
      }
      if (offset + sizeof(struct sctp_idata_chunk) + SCTP_NUM_DB_TO_VERIFY > limit) {
        /* Not enough data in buffer. */
        break;
      }
      idata_chunk = (struct sctp_idata_chunk *)(cp->data + offset);
      memcpy(desc.data_bytes, idata_chunk + 1, SCTP_NUM_DB_TO_VERIFY);
      desc.tsn_ifany = idata_chunk->dp.tsn;
      if (pktdrp_flags & SCTP_FROM_MIDDLE_BOX) {
        SCTP_STAT_INCR(sctps_pdrpmbda);
      }
    } else {
      desc.tsn_ifany = htonl(0);
      memset(desc.data_bytes, 0, SCTP_NUM_DB_TO_VERIFY);
      if (pktdrp_flags & SCTP_FROM_MIDDLE_BOX) {
        SCTP_STAT_INCR(sctps_pdrpmbct);
      }
    }
    if (process_chunk_drop(stcb, &desc, net, pktdrp_flags)) {
      SCTP_STAT_INCR(sctps_pdrppdbrk);
      break;
    }
next_chunk:
    offset += SCTP_SIZE32(chk_len);
  }
  /* Now update any rwnd --- possibly */
  if ((pktdrp_flags & SCTP_FROM_MIDDLE_BOX) == 0) {
    /* From a peer, we get a rwnd report */
    uint32_t a_rwnd;

    SCTP_STAT_INCR(sctps_pdrpfehos);

    bottle_bw = ntohl(cp->bottle_bw);
    on_queue = ntohl(cp->current_onq);
    if (bottle_bw && on_queue) {
      /* a rwnd report is in here */
      if (bottle_bw > on_queue)
        a_rwnd = bottle_bw - on_queue;
      else
        a_rwnd = 0;

      if (a_rwnd == 0)
        stcb->asoc.peers_rwnd = 0;
      else {
        if (a_rwnd > stcb->asoc.total_flight) {
          stcb->asoc.peers_rwnd =
              a_rwnd - stcb->asoc.total_flight;
        } else {
          stcb->asoc.peers_rwnd = 0;
        }
        if (stcb->asoc.peers_rwnd <
            stcb->sctp_ep->sctp_ep.sctp_sws_sender) {
          /* SWS sender side engages */
          stcb->asoc.peers_rwnd = 0;
        }
      }
    }
  } else {
    SCTP_STAT_INCR(sctps_pdrpfmbox);
  }

  /* now middle boxes in sat networks get a cwnd bump */
  if ((pktdrp_flags & SCTP_FROM_MIDDLE_BOX) &&
      (stcb->asoc.sat_t3_loss_recovery == 0) &&
      (stcb->asoc.sat_network)) {
    /*
     * This is debatable but for sat networks it makes sense
     * Note if a T3 timer has went off, we will prohibit any
     * changes to cwnd until we exit the t3 loss recovery.
     */
    stcb->asoc.cc_functions.sctp_cwnd_update_after_packet_dropped(stcb,
      net, cp, &bottle_bw, &on_queue);
  }
}

/*
 * handles all control chunks in a packet inputs: - m: mbuf chain, assumed to
 * still contain IP/SCTP header - stcb: is the tcb found for this packet -
 * offset: offset into the mbuf chain to first chunkhdr - length: is the
 * length of the complete packet outputs: - length: modified to remaining
 * length after control processing - netp: modified to new sctp_nets after
 * cookie-echo processing - return NULL to discard the packet (ie. no asoc,
 * bad packet,...) otherwise return the tcb for this packet
 */
#ifdef __GNUC__
__attribute__ ((noinline))
#endif
static struct sctp_tcb *
sctp_process_control(struct mbuf *m, int iphlen, int *offset, int length,
    struct sockaddr *src, struct sockaddr *dst,
    struct sctphdr *sh, struct sctp_chunkhdr *ch, struct sctp_inpcb *inp,
    struct sctp_tcb *stcb, struct sctp_nets **netp, int *fwd_tsn_seen,
#if defined(__FreeBSD__) && !defined(__Userspace__)
    uint8_t mflowtype, uint32_t mflowid, uint16_t fibnum,
#endif
    uint32_t vrf_id, uint16_t port)
{
  struct sctp_association *asoc;
  struct mbuf *op_err;
  char msg[SCTP_DIAG_INFO_LEN];
  uint32_t vtag_in;
  int num_chunks = 0; /* number of control chunks processed */
  uint32_t chk_length, contiguous;
  int ret;
  int abort_no_unlock = 0;
  int ecne_seen = 0;
  int abort_flag;
  /*
   * How big should this be, and should it be alloc'd? Lets try the
   * d-mtu-ceiling for now (2k) and that should hopefully work ...
   * until we get into jumbo grams and such..
   */
  uint8_t chunk_buf[SCTP_CHUNK_BUFFER_SIZE];
  int got_auth = 0;
  uint32_t auth_offset = 0, auth_len = 0;
  int auth_skipped = 0;
  int asconf_cnt = 0;
#if defined(__APPLE__) && !defined(__Userspace__)
  struct socket *so;
#endif

  SCTPDBG(SCTP_DEBUG_INPUT1, "sctp_process_control: iphlen=%u, offset=%u, length=%u stcb:%p\n",
    iphlen, *offset, length, (void *)stcb);

  if (stcb) {
    SCTP_TCB_LOCK_ASSERT(stcb);
  }
  /* validate chunk header length... */
  if (ntohs(ch->chunk_length) < sizeof(*ch)) {
    SCTPDBG(SCTP_DEBUG_INPUT1, "Invalid header length %d\n",
      ntohs(ch->chunk_length));
    *offset = length;
    return (stcb);
  }
  /*
   * validate the verification tag
   */
  vtag_in = ntohl(sh->v_tag);

  if (ch->chunk_type == SCTP_INITIATION) {
    SCTPDBG(SCTP_DEBUG_INPUT1, "Its an INIT of len:%d vtag:%x\n",
      ntohs(ch->chunk_length), vtag_in);
    if (vtag_in != 0) {
      /* protocol error- silently discard... */
      SCTP_STAT_INCR(sctps_badvtag);
      if (stcb != NULL) {
        SCTP_TCB_UNLOCK(stcb);
      }
      return (NULL);
    }
  } else if (ch->chunk_type != SCTP_COOKIE_ECHO) {
    /*
     * If there is no stcb, skip the AUTH chunk and process
     * later after a stcb is found (to validate the lookup was
     * valid.
     */
    if ((ch->chunk_type == SCTP_AUTHENTICATION) &&
        (stcb == NULL) &&
        (inp->auth_supported == 1)) {
      /* save this chunk for later processing */
      auth_skipped = 1;
      auth_offset = *offset;
      auth_len = ntohs(ch->chunk_length);

      /* (temporarily) move past this chunk */
      *offset += SCTP_SIZE32(auth_len);
      if (*offset >= length) {
        /* no more data left in the mbuf chain */
        *offset = length;
        return (NULL);
      }
      ch = (struct sctp_chunkhdr *)sctp_m_getptr(m, *offset,
                   sizeof(struct sctp_chunkhdr), chunk_buf);
    }
    if (ch == NULL) {
      /* Help */
      *offset = length;
      return (stcb);
    }
    if (ch->chunk_type == SCTP_COOKIE_ECHO) {
      goto process_control_chunks;
    }
    /*
     * first check if it's an ASCONF with an unknown src addr we
     * need to look inside to find the association
     */
    if (ch->chunk_type == SCTP_ASCONF && stcb == NULL) {
      struct sctp_chunkhdr *asconf_ch = ch;
      uint32_t asconf_offset = 0, asconf_len = 0;

      /* inp's refcount may be reduced */
      SCTP_INP_INCR_REF(inp);

      asconf_offset = *offset;
      do {
        asconf_len = ntohs(asconf_ch->chunk_length);
        if (asconf_len < sizeof(struct sctp_asconf_paramhdr))
          break;
        stcb = sctp_findassociation_ep_asconf(m,
                                              *offset,
                                              dst,
                                              sh, &inp, netp, vrf_id);
        if (stcb != NULL)
          break;
        asconf_offset += SCTP_SIZE32(asconf_len);
        asconf_ch = (struct sctp_chunkhdr *)sctp_m_getptr(m, asconf_offset,
                      sizeof(struct sctp_chunkhdr), chunk_buf);
      } while (asconf_ch != NULL && asconf_ch->chunk_type == SCTP_ASCONF);
      if (stcb == NULL) {
        /*
         * reduce inp's refcount if not reduced in
         * sctp_findassociation_ep_asconf().
         */
        SCTP_INP_DECR_REF(inp);
      }

      /* now go back and verify any auth chunk to be sure */
      if (auth_skipped && (stcb != NULL)) {
        struct sctp_auth_chunk *auth;

        if (auth_len <= SCTP_CHUNK_BUFFER_SIZE) {
          auth = (struct sctp_auth_chunk *)sctp_m_getptr(m, auth_offset, auth_len, chunk_buf);
          got_auth = 1;
          auth_skipped = 0;
        } else {
          auth = NULL;
        }
        if ((auth == NULL) || sctp_handle_auth(stcb, auth, m,
                       auth_offset)) {
          /* auth HMAC failed so dump it */
          *offset = length;
          return (stcb);
        } else {
          /* remaining chunks are HMAC checked */
          stcb->asoc.authenticated = 1;
        }
      }
    }
    if (stcb == NULL) {
      SCTP_SNPRINTF(msg, sizeof(msg), "OOTB, %s:%d at %s", __FILE__, __LINE__, __func__);
      op_err = sctp_generate_cause(SCTP_BASE_SYSCTL(sctp_diag_info_code),
                                   msg);
      /* no association, so it's out of the blue... */
      sctp_handle_ootb(m, iphlen, *offset, src, dst, sh, inp, op_err,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                       mflowtype, mflowid, inp->fibnum,
#endif
           vrf_id, port);
      *offset = length;
      return (NULL);
    }
    asoc = &stcb->asoc;
    /* ABORT and SHUTDOWN can use either v_tag... */
    if ((ch->chunk_type == SCTP_ABORT_ASSOCIATION) ||
        (ch->chunk_type == SCTP_SHUTDOWN_COMPLETE) ||
        (ch->chunk_type == SCTP_PACKET_DROPPED)) {
      /* Take the T-bit always into account. */
      if ((((ch->chunk_flags & SCTP_HAD_NO_TCB) == 0) &&
           (vtag_in == asoc->my_vtag)) ||
          (((ch->chunk_flags & SCTP_HAD_NO_TCB) == SCTP_HAD_NO_TCB) &&
           (asoc->peer_vtag != htonl(0)) &&
           (vtag_in == asoc->peer_vtag))) {
        /* this is valid */
      } else {
        /* drop this packet... */
        SCTP_STAT_INCR(sctps_badvtag);
        if (stcb != NULL) {
          SCTP_TCB_UNLOCK(stcb);
        }
        return (NULL);
      }
    } else {
      /* for all other chunks, vtag must match */
      if (vtag_in != asoc->my_vtag) {
        /* invalid vtag... */
        SCTPDBG(SCTP_DEBUG_INPUT3,
          "invalid vtag: %xh, expect %xh\n",
          vtag_in, asoc->my_vtag);
        SCTP_STAT_INCR(sctps_badvtag);
        if (stcb != NULL) {
          SCTP_TCB_UNLOCK(stcb);
        }
        *offset = length;
        return (NULL);
      }
    }
  }      /* end if !SCTP_COOKIE_ECHO */
  /*
   * process all control chunks...
   */
  if (((ch->chunk_type == SCTP_SELECTIVE_ACK) ||
       (ch->chunk_type == SCTP_NR_SELECTIVE_ACK) ||
       (ch->chunk_type == SCTP_HEARTBEAT_REQUEST)) &&
      (SCTP_GET_STATE(stcb) == SCTP_STATE_COOKIE_ECHOED)) {
    /* implied cookie-ack.. we must have lost the ack */
    sctp_handle_cookie_ack((struct sctp_cookie_ack_chunk *)ch, stcb,
               *netp);
  }

 process_control_chunks:
  while (IS_SCTP_CONTROL(ch)) {
    /* validate chunk length */
    chk_length = ntohs(ch->chunk_length);
    SCTPDBG(SCTP_DEBUG_INPUT2, "sctp_process_control: processing a chunk type=%u, len=%u\n",
      ch->chunk_type, chk_length);
    SCTP_LTRACE_CHK(inp, stcb, ch->chunk_type, chk_length);
    if (chk_length < sizeof(*ch) ||
        (*offset + (int)chk_length) > length) {
      *offset = length;
      return (stcb);
    }
    SCTP_STAT_INCR_COUNTER64(sctps_incontrolchunks);
    /*
     * INIT and INIT-ACK only gets the init ack "header" portion
     * only because we don't have to process the peer's COOKIE.
     * All others get a complete chunk.
     */
    switch (ch->chunk_type) {
    case SCTP_INITIATION:
      contiguous = sizeof(struct sctp_init_chunk);
      break;
    case SCTP_INITIATION_ACK:
      contiguous = sizeof(struct sctp_init_ack_chunk);
      break;
    default:
      contiguous = min(chk_length, sizeof(chunk_buf));
      break;
    }
    ch = (struct sctp_chunkhdr *)sctp_m_getptr(m, *offset,
                                               contiguous,
                                               chunk_buf);
    if (ch == NULL) {
      *offset = length;
      return (stcb);
    }

    num_chunks++;
    /* Save off the last place we got a control from */
    if (stcb != NULL) {
      if (((netp != NULL) && (*netp != NULL)) || (ch->chunk_type == SCTP_ASCONF)) {
        /*
         * allow last_control to be NULL if
         * ASCONF... ASCONF processing will find the
         * right net later
         */
        if ((netp != NULL) && (*netp != NULL))
          stcb->asoc.last_control_chunk_from = *netp;
      }
    }
#ifdef SCTP_AUDITING_ENABLED
    sctp_audit_log(0xB0, ch->chunk_type);
#endif

    /* check to see if this chunk required auth, but isn't */
    if ((stcb != NULL) &&
        sctp_auth_is_required_chunk(ch->chunk_type, stcb->asoc.local_auth_chunks) &&
        !stcb->asoc.authenticated) {
      /* "silently" ignore */
      SCTP_STAT_INCR(sctps_recvauthmissing);
      goto next_chunk;
    }
    switch (ch->chunk_type) {
    case SCTP_INITIATION:
      SCTPDBG(SCTP_DEBUG_INPUT3, "SCTP_INIT\n");
      /* The INIT chunk must be the only chunk. */
      if ((num_chunks > 1) ||
          (length - *offset > (int)SCTP_SIZE32(chk_length))) {
        /*
         * RFC 4960bis requires stopping the
         * processing of the packet.
         */
        *offset = length;
        return (stcb);
      }
      /* Honor our resource limit. */
      if (chk_length > SCTP_LARGEST_INIT_ACCEPTED) {
        op_err = sctp_generate_cause(SCTP_CAUSE_OUT_OF_RESC, "");
        sctp_send_abort(m, iphlen, src, dst, sh, 0, op_err,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                        mflowtype, mflowid, inp->fibnum,
#endif
                        vrf_id, port);
        *offset = length;
        if (stcb != NULL) {
          SCTP_TCB_UNLOCK(stcb);
        }
        return (NULL);
      }
      sctp_handle_init(m, iphlen, *offset, src, dst, sh,
                       (struct sctp_init_chunk *)ch, inp,
                       stcb, *netp,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                       mflowtype, mflowid,
#endif
                       vrf_id, port);
      *offset = length;
      if (stcb != NULL) {
        SCTP_TCB_UNLOCK(stcb);
      }
      return (NULL);
      break;
    case SCTP_PAD_CHUNK:
      break;
    case SCTP_INITIATION_ACK:
      SCTPDBG(SCTP_DEBUG_INPUT3, "SCTP_INIT_ACK\n");
      if (inp->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE) {
        /* We are not interested anymore */
        if ((stcb != NULL) && (stcb->asoc.total_output_queue_size)) {
          ;
        } else {
          *offset = length;
          if (stcb != NULL) {
#if defined(__APPLE__) && !defined(__Userspace__)
            so = SCTP_INP_SO(inp);
            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);
#endif
            (void)sctp_free_assoc(inp, stcb, SCTP_NORMAL_PROC,
                                  SCTP_FROM_SCTP_INPUT + SCTP_LOC_29);
#if defined(__APPLE__) && !defined(__Userspace__)
            SCTP_SOCKET_UNLOCK(so, 1);
#endif
          }
          return (NULL);
        }
      }
      /* The INIT-ACK chunk must be the only chunk. */
      if ((num_chunks > 1) ||
          (length - *offset > (int)SCTP_SIZE32(chk_length))) {
        *offset = length;
        return (stcb);
      }
      if ((netp != NULL) && (*netp != NULL)) {
        ret = sctp_handle_init_ack(m, iphlen, *offset,
                                   src, dst, sh,
                                   (struct sctp_init_ack_chunk *)ch,
                                   stcb, *netp,
                                   &abort_no_unlock,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                                   mflowtype, mflowid,
#endif
                                   vrf_id);
      } else {
        ret = -1;
      }
      *offset = length;
      if (abort_no_unlock) {
        return (NULL);
      }
      /*
       * Special case, I must call the output routine to
       * get the cookie echoed
       */
      if ((stcb != NULL) && (ret == 0)) {
        sctp_chunk_output(stcb->sctp_ep, stcb, SCTP_OUTPUT_FROM_CONTROL_PROC, SCTP_SO_NOT_LOCKED);
      }
      return (stcb);
      break;
    case SCTP_SELECTIVE_ACK:
    case SCTP_NR_SELECTIVE_ACK:
    {
      int abort_now = 0;
      uint32_t a_rwnd, cum_ack;
      uint16_t num_seg, num_nr_seg, num_dup;
      uint8_t flags;
      int offset_seg, offset_dup;

      SCTPDBG(SCTP_DEBUG_INPUT3, "%s\n",
        ch->chunk_type == SCTP_SELECTIVE_ACK ? "SCTP_SACK" : "SCTP_NR_SACK");
      SCTP_STAT_INCR(sctps_recvsacks);
      if (stcb == NULL) {
        SCTPDBG(SCTP_DEBUG_INDATA1, "No stcb when processing %s chunk\n",
                (ch->chunk_type == SCTP_SELECTIVE_ACK) ? "SCTP_SACK" : "SCTP_NR_SACK");
        break;
      }
      if (ch->chunk_type == SCTP_SELECTIVE_ACK) {
        if (chk_length < sizeof(struct sctp_sack_chunk)) {
          SCTPDBG(SCTP_DEBUG_INDATA1, "Bad size on SACK chunk, too small\n");
          break;
        }
      } else {
        if (stcb->asoc.nrsack_supported == 0) {
          goto unknown_chunk;
        }
        if (chk_length < sizeof(struct sctp_nr_sack_chunk)) {
          SCTPDBG(SCTP_DEBUG_INDATA1, "Bad size on NR_SACK chunk, too small\n");
          break;
        }
      }
      if (SCTP_GET_STATE(stcb) == SCTP_STATE_SHUTDOWN_ACK_SENT) {
        /*-
         * If we have sent a shutdown-ack, we will pay no
         * attention to a sack sent in to us since
         * we don't care anymore.
         */
        break;
      }
      flags = ch->chunk_flags;
      if (ch->chunk_type == SCTP_SELECTIVE_ACK) {
        struct sctp_sack_chunk *sack;

        sack = (struct sctp_sack_chunk *)ch;
        cum_ack = ntohl(sack->sack.cum_tsn_ack);
        num_seg = ntohs(sack->sack.num_gap_ack_blks);
        num_nr_seg = 0;
        num_dup = ntohs(sack->sack.num_dup_tsns);
        a_rwnd = ntohl(sack->sack.a_rwnd);
        if (sizeof(struct sctp_sack_chunk) +
            num_seg * sizeof(struct sctp_gap_ack_block) +
            num_dup * sizeof(uint32_t) != chk_length) {
          SCTPDBG(SCTP_DEBUG_INDATA1, "Bad size of SACK chunk\n");
          break;
        }
        offset_seg = *offset + sizeof(struct sctp_sack_chunk);
        offset_dup = offset_seg + num_seg * sizeof(struct sctp_gap_ack_block);
      } else {
        struct sctp_nr_sack_chunk *nr_sack;

        nr_sack = (struct sctp_nr_sack_chunk *)ch;
        cum_ack = ntohl(nr_sack->nr_sack.cum_tsn_ack);
        num_seg = ntohs(nr_sack->nr_sack.num_gap_ack_blks);
        num_nr_seg = ntohs(nr_sack->nr_sack.num_nr_gap_ack_blks);
        num_dup = ntohs(nr_sack->nr_sack.num_dup_tsns);
        a_rwnd = ntohl(nr_sack->nr_sack.a_rwnd);
        if (sizeof(struct sctp_nr_sack_chunk) +
            (num_seg + num_nr_seg) * sizeof(struct sctp_gap_ack_block) +
            num_dup * sizeof(uint32_t) != chk_length) {
          SCTPDBG(SCTP_DEBUG_INDATA1, "Bad size of NR_SACK chunk\n");
          break;
        }
        offset_seg = *offset + sizeof(struct sctp_nr_sack_chunk);
        offset_dup = offset_seg + (num_seg + num_nr_seg) * sizeof(struct sctp_gap_ack_block);
      }
      SCTPDBG(SCTP_DEBUG_INPUT3, "%s process cum_ack:%x num_seg:%d a_rwnd:%d\n",
        (ch->chunk_type == SCTP_SELECTIVE_ACK) ? "SCTP_SACK" : "SCTP_NR_SACK",
              cum_ack, num_seg, a_rwnd);
      stcb->asoc.seen_a_sack_this_pkt = 1;
      if ((stcb->asoc.pr_sctp_cnt == 0) &&
          (num_seg == 0) && (num_nr_seg == 0) &&
          SCTP_TSN_GE(cum_ack, stcb->asoc.last_acked_seq) &&
          (stcb->asoc.saw_sack_with_frags == 0) &&
          (stcb->asoc.saw_sack_with_nr_frags == 0) &&
          (!TAILQ_EMPTY(&stcb->asoc.sent_queue))) {
        /*
         * We have a SIMPLE sack having no
         * prior segments and data on sent
         * queue to be acked. Use the
         * faster path sack processing. We
         * also allow window update sacks
         * with no missing segments to go
         * this way too.
         */
        sctp_express_handle_sack(stcb, cum_ack, a_rwnd,
                                 &abort_now, ecne_seen);
      } else {
        if ((netp != NULL) && (*netp != NULL)) {
          sctp_handle_sack(m, offset_seg, offset_dup, stcb,
                           num_seg, num_nr_seg, num_dup, &abort_now, flags,
                           cum_ack, a_rwnd, ecne_seen);
        }
      }
      if (abort_now) {
        /* ABORT signal from sack processing */
        *offset = length;
        return (NULL);
      }
      if (TAILQ_EMPTY(&stcb->asoc.send_queue) &&
          TAILQ_EMPTY(&stcb->asoc.sent_queue) &&
          (stcb->asoc.stream_queue_cnt == 0)) {
        sctp_ulp_notify(SCTP_NOTIFY_SENDER_DRY, stcb,  0, NULL, SCTP_SO_NOT_LOCKED);
      }
      break;
    }
    case SCTP_HEARTBEAT_REQUEST:
      SCTPDBG(SCTP_DEBUG_INPUT3, "SCTP_HEARTBEAT\n");
      if ((stcb != NULL) && (netp != NULL) && (*netp != NULL)) {
        SCTP_STAT_INCR(sctps_recvheartbeat);
        sctp_send_heartbeat_ack(stcb, m, *offset,
                                chk_length, *netp);
      }
      break;
    case SCTP_HEARTBEAT_ACK:
      SCTPDBG(SCTP_DEBUG_INPUT3, "SCTP_HEARTBEAT_ACK\n");
      if ((stcb == NULL) || (chk_length != sizeof(struct sctp_heartbeat_chunk))) {
        /* Its not ours */
        break;
      }
      SCTP_STAT_INCR(sctps_recvheartbeatack);
      if ((netp != NULL) && (*netp != NULL)) {
        sctp_handle_heartbeat_ack((struct sctp_heartbeat_chunk *)ch,
                                  stcb, *netp);
      }
      break;
    case SCTP_ABORT_ASSOCIATION:
      SCTPDBG(SCTP_DEBUG_INPUT3, "SCTP_ABORT, stcb %p\n",
        (void *)stcb);
      *offset = length;
      if ((stcb != NULL) && (netp != NULL) && (*netp != NULL)) {
        if (sctp_handle_abort((struct sctp_abort_chunk *)ch, stcb, *netp)) {
          return (NULL);
        } else {
          return (stcb);
        }
      } else {
        return (NULL);
      }
      break;
    case SCTP_SHUTDOWN:
      SCTPDBG(SCTP_DEBUG_INPUT3, "SCTP_SHUTDOWN, stcb %p\n",
        (void *)stcb);
      if ((stcb == NULL) || (chk_length != sizeof(struct sctp_shutdown_chunk))) {
        break;
      }
      if ((netp != NULL) && (*netp != NULL)) {
        abort_flag = 0;
        sctp_handle_shutdown((struct sctp_shutdown_chunk *)ch,
                             stcb, *netp, &abort_flag);
        if (abort_flag) {
          *offset = length;
          return (NULL);
        }
      }
      break;
    case SCTP_SHUTDOWN_ACK:
      SCTPDBG(SCTP_DEBUG_INPUT3, "SCTP_SHUTDOWN_ACK, stcb %p\n", (void *)stcb);
      if ((chk_length == sizeof(struct sctp_shutdown_ack_chunk)) &&
          (stcb != NULL) && (netp != NULL) && (*netp != NULL)) {
        sctp_handle_shutdown_ack((struct sctp_shutdown_ack_chunk *)ch, stcb, *netp);
        *offset = length;
        return (NULL);
      }
      break;
    case SCTP_OPERATION_ERROR:
      SCTPDBG(SCTP_DEBUG_INPUT3, "SCTP_OP_ERR\n");
      if ((stcb != NULL) && (netp != NULL) && (*netp != NULL) &&
          sctp_handle_error(ch, stcb, *netp, contiguous) < 0) {
        *offset = length;
        return (NULL);
      }
      break;
    case SCTP_COOKIE_ECHO:
      SCTPDBG(SCTP_DEBUG_INPUT3,
        "SCTP_COOKIE_ECHO, stcb %p\n", (void *)stcb);
      if ((stcb != NULL) && (stcb->asoc.total_output_queue_size > 0)) {
        ;
      } else {
        if (inp->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE) {
          /* We are not interested anymore */
        abend:
          if (stcb != NULL) {
            SCTP_TCB_UNLOCK(stcb);
          }
          *offset = length;
          return (NULL);
        }
      }
      /*-
       * First are we accepting? We do this again here
       * since it is possible that a previous endpoint WAS
       * listening responded to a INIT-ACK and then
       * closed. We opened and bound.. and are now no
       * longer listening.
       *
       * XXXGL: notes on checking listen queue length.
       * 1) SCTP_IS_LISTENING() doesn't necessarily mean
       *    SOLISTENING(), because a listening "UDP type"
       *    socket isn't listening in terms of the socket
       *    layer.  It is a normal data flow socket, that
       *    can fork off new connections.  Thus, we should
       *    look into sol_qlen only in case we are !UDP.
       * 2) Checking sol_qlen in general requires locking
       *    the socket, and this code lacks that.
       */
      if ((stcb == NULL) &&
          (!SCTP_IS_LISTENING(inp) ||
           (((inp->sctp_flags & SCTP_PCB_FLAGS_UDPTYPE) == 0) &&
#if defined(__FreeBSD__) && !defined(__Userspace__)
            inp->sctp_socket->sol_qlen >= inp->sctp_socket->sol_qlimit))) {
#else
            inp->sctp_socket->so_qlen >= inp->sctp_socket->so_qlimit))) {
#endif
        if ((inp->sctp_flags & SCTP_PCB_FLAGS_TCPTYPE) &&
            (SCTP_BASE_SYSCTL(sctp_abort_if_one_2_one_hits_limit))) {
          op_err = sctp_generate_cause(SCTP_CAUSE_OUT_OF_RESC, "");
          sctp_abort_association(inp, stcb, m, iphlen,
                                 src, dst, sh, op_err,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                                 mflowtype, mflowid,
#endif
                                 vrf_id, port);
        }
        *offset = length;
        return (NULL);
      } else {
        struct mbuf *ret_buf;
        struct sctp_inpcb *linp;
        struct sctp_tmit_chunk *chk;

        if (inp->sctp_flags & (SCTP_PCB_FLAGS_SOCKET_GONE |
            SCTP_PCB_FLAGS_SOCKET_ALLGONE)) {
          goto abend;
        }

        if (stcb) {
          linp = NULL;
        } else {
          linp = inp;
        }

        if (linp != NULL) {
          SCTP_ASOC_CREATE_LOCK(linp);
        }

        if (netp != NULL) {
          struct sctp_tcb *locked_stcb;

          locked_stcb = stcb;
          ret_buf =
            sctp_handle_cookie_echo(m, iphlen,
                                    *offset,
                                    src, dst,
                                    sh,
                                    (struct sctp_cookie_echo_chunk *)ch,
                                    &inp, &stcb, netp,
                                    auth_skipped,
                                    auth_offset,
                                    auth_len,
                                    &locked_stcb,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                                    mflowtype,
                                    mflowid,
#endif
                                    vrf_id,
                                    port);
          if ((locked_stcb != NULL) && (locked_stcb != stcb)) {
            SCTP_TCB_UNLOCK(locked_stcb);
          }
          if (stcb != NULL) {
            SCTP_TCB_LOCK_ASSERT(stcb);
          }
        } else {
          ret_buf = NULL;
        }
        if (linp != NULL) {
          SCTP_ASOC_CREATE_UNLOCK(linp);
        }
        if (ret_buf == NULL) {
          if (stcb != NULL) {
            SCTP_TCB_UNLOCK(stcb);
          }
          SCTPDBG(SCTP_DEBUG_INPUT3,
            "GAK, null buffer\n");
          *offset = length;
          return (NULL);
        }
        /* if AUTH skipped, see if it verified... */
        if (auth_skipped) {
          got_auth = 1;
          auth_skipped = 0;
        }
        /* Restart the timer if we have pending data */
        TAILQ_FOREACH(chk, &stcb->asoc.sent_queue, sctp_next) {
          if (chk->whoTo != NULL) {
            break;
          }
        }
        if (chk != NULL) {
          sctp_timer_start(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep, stcb, chk->whoTo);
        }
      }
      break;
    case SCTP_COOKIE_ACK:
      SCTPDBG(SCTP_DEBUG_INPUT3, "SCTP_COOKIE_ACK, stcb %p\n", (void *)stcb);
      if ((stcb == NULL) || chk_length != sizeof(struct sctp_cookie_ack_chunk)) {
        break;
      }
      if (inp->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE) {
        /* We are not interested anymore */
        if ((stcb) && (stcb->asoc.total_output_queue_size)) {
          ;
        } else if (stcb) {
#if defined(__APPLE__) && !defined(__Userspace__)
          so = SCTP_INP_SO(inp);
          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);
#endif
          (void)sctp_free_assoc(inp, stcb, SCTP_NORMAL_PROC,
                                SCTP_FROM_SCTP_INPUT + SCTP_LOC_30);
#if defined(__APPLE__) && !defined(__Userspace__)
          SCTP_SOCKET_UNLOCK(so, 1);
#endif
          *offset = length;
          return (NULL);
        }
      }
      if ((netp != NULL) && (*netp != NULL)) {
        sctp_handle_cookie_ack((struct sctp_cookie_ack_chunk *)ch, stcb, *netp);
      }
      break;
    case SCTP_ECN_ECHO:
      SCTPDBG(SCTP_DEBUG_INPUT3, "SCTP_ECN_ECHO\n");
      if (stcb == NULL) {
        break;
      }
      if (stcb->asoc.ecn_supported == 0) {
        goto unknown_chunk;
      }
      if ((chk_length != sizeof(struct sctp_ecne_chunk)) &&
          (chk_length != sizeof(struct old_sctp_ecne_chunk))) {
        break;
      }
      sctp_handle_ecn_echo((struct sctp_ecne_chunk *)ch, stcb);
      ecne_seen = 1;
      break;
    case SCTP_ECN_CWR:
      SCTPDBG(SCTP_DEBUG_INPUT3, "SCTP_ECN_CWR\n");
      if (stcb == NULL) {
        break;
      }
      if (stcb->asoc.ecn_supported == 0) {
        goto unknown_chunk;
      }
      if (chk_length != sizeof(struct sctp_cwr_chunk)) {
        break;
      }
      sctp_handle_ecn_cwr((struct sctp_cwr_chunk *)ch, stcb, *netp);
      break;
    case SCTP_SHUTDOWN_COMPLETE:
      SCTPDBG(SCTP_DEBUG_INPUT3, "SCTP_SHUTDOWN_COMPLETE, stcb %p\n", (void *)stcb);
      /* must be first and only chunk */
      if ((num_chunks > 1) ||
          (length - *offset > (int)SCTP_SIZE32(chk_length))) {
        *offset = length;
        return (stcb);
      }
      if ((chk_length == sizeof(struct sctp_shutdown_complete_chunk)) &&
          (stcb != NULL) && (netp != NULL) && (*netp != NULL)) {
        sctp_handle_shutdown_complete((struct sctp_shutdown_complete_chunk *)ch,
                                      stcb, *netp);
        *offset = length;
        return (NULL);
      }
      break;
    case SCTP_ASCONF:
      SCTPDBG(SCTP_DEBUG_INPUT3, "SCTP_ASCONF\n");
      if (stcb != NULL) {
        if (stcb->asoc.asconf_supported == 0) {
          goto unknown_chunk;
        }
        sctp_handle_asconf(m, *offset, src,
                           (struct sctp_asconf_chunk *)ch, stcb, asconf_cnt == 0);
        asconf_cnt++;
      }
      break;
    case SCTP_ASCONF_ACK:
      SCTPDBG(SCTP_DEBUG_INPUT3, "SCTP_ASCONF_ACK\n");
      if (stcb == NULL) {
        break;
      }
      if (stcb->asoc.asconf_supported == 0) {
        goto unknown_chunk;
      }
      if (chk_length < sizeof(struct sctp_asconf_ack_chunk)) {
        break;
      }
      if ((netp != NULL) && (*netp != NULL)) {
        /* He's alive so give him credit */
        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_THRESHOLD_LOGGING) {
          sctp_misc_ints(SCTP_THRESHOLD_CLEAR,
                         stcb->asoc.overall_error_count,
                         0,
                         SCTP_FROM_SCTP_INPUT,
                         __LINE__);
        }
        stcb->asoc.overall_error_count = 0;
        sctp_handle_asconf_ack(m, *offset,
                               (struct sctp_asconf_ack_chunk *)ch, stcb, *netp, &abort_no_unlock);
        if (abort_no_unlock)
          return (NULL);
      }
      break;
    case SCTP_FORWARD_CUM_TSN:
    case SCTP_IFORWARD_CUM_TSN:
      SCTPDBG(SCTP_DEBUG_INPUT3, "%s\n",
        ch->chunk_type == SCTP_FORWARD_CUM_TSN ? "FORWARD_TSN" : "I_FORWARD_TSN");
      if (stcb == NULL) {
        break;
      }
      if (stcb->asoc.prsctp_supported == 0) {
        goto unknown_chunk;
      }
      if (chk_length < sizeof(struct sctp_forward_tsn_chunk)) {
        break;
      }
      if (((stcb->asoc.idata_supported == 1) && (ch->chunk_type == SCTP_FORWARD_CUM_TSN)) ||
          ((stcb->asoc.idata_supported == 0) && (ch->chunk_type == SCTP_IFORWARD_CUM_TSN))) {
        if (ch->chunk_type == SCTP_FORWARD_CUM_TSN) {
          SCTP_SNPRINTF(msg, sizeof(msg), "%s", "FORWARD-TSN chunk received when I-FORWARD-TSN was negotiated");
        } else {
          SCTP_SNPRINTF(msg, sizeof(msg), "%s", "I-FORWARD-TSN chunk received when FORWARD-TSN was negotiated");
        }
        op_err = sctp_generate_cause(SCTP_CAUSE_PROTOCOL_VIOLATION, msg);
        sctp_abort_an_association(inp, stcb, op_err, false, SCTP_SO_NOT_LOCKED);
        *offset = length;
        return (NULL);
      }
      *fwd_tsn_seen = 1;
      if (inp->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE) {
        /* We are not interested anymore */
#if defined(__APPLE__) && !defined(__Userspace__)
        so = SCTP_INP_SO(inp);
        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);
#endif
        (void)sctp_free_assoc(inp, stcb, SCTP_NORMAL_PROC,
                              SCTP_FROM_SCTP_INPUT + SCTP_LOC_31);
#if defined(__APPLE__) && !defined(__Userspace__)
        SCTP_SOCKET_UNLOCK(so, 1);
#endif
        *offset = length;
        return (NULL);
      }
      /*
       * For sending a SACK this looks like DATA
       * chunks.
       */
      stcb->asoc.last_data_chunk_from = stcb->asoc.last_control_chunk_from;
      abort_flag = 0;
      sctp_handle_forward_tsn(stcb,
                              (struct sctp_forward_tsn_chunk *)ch, &abort_flag, m, *offset);
      if (abort_flag) {
        *offset = length;
        return (NULL);
      }
      break;
    case SCTP_STREAM_RESET:
      SCTPDBG(SCTP_DEBUG_INPUT3, "SCTP_STREAM_RESET\n");
      if (stcb == NULL) {
        break;
      }
      if (stcb->asoc.reconfig_supported == 0) {
        goto unknown_chunk;
      }
      if (chk_length < sizeof(struct sctp_stream_reset_tsn_req)) {
        break;
      }
      if (sctp_handle_stream_reset(stcb, m, *offset, ch)) {
        /* stop processing */
        *offset = length;
        return (NULL);
      }
      break;
    case SCTP_PACKET_DROPPED:
      SCTPDBG(SCTP_DEBUG_INPUT3, "SCTP_PACKET_DROPPED\n");
      if (stcb == NULL) {
        break;
      }
      if (stcb->asoc.pktdrop_supported == 0) {
        goto unknown_chunk;
      }
      if (chk_length < sizeof(struct sctp_pktdrop_chunk)) {
        break;
      }
      if ((netp != NULL) && (*netp != NULL)) {
        sctp_handle_packet_dropped((struct sctp_pktdrop_chunk *)ch,
                                   stcb, *netp,
                                   min(chk_length, contiguous));
      }
      break;
    case SCTP_AUTHENTICATION:
      SCTPDBG(SCTP_DEBUG_INPUT3, "SCTP_AUTHENTICATION\n");
      if (stcb == NULL) {
        /* save the first AUTH for later processing */
        if (auth_skipped == 0) {
          auth_offset = *offset;
          auth_len = chk_length;
          auth_skipped = 1;
        }
        /* skip this chunk (temporarily) */
        break;
      }
      if (stcb->asoc.auth_supported == 0) {
        goto unknown_chunk;
      }
      if ((chk_length < (sizeof(struct sctp_auth_chunk))) ||
          (chk_length > (sizeof(struct sctp_auth_chunk) +
                        SCTP_AUTH_DIGEST_LEN_MAX))) {
        /* Its not ours */
        *offset = length;
        return (stcb);
      }
      if (got_auth == 1) {
        /* skip this chunk... it's already auth'd */
        break;
      }
      got_auth = 1;
      if (sctp_handle_auth(stcb, (struct sctp_auth_chunk *)ch, m, *offset)) {
        /* auth HMAC failed so dump the packet */
        *offset = length;
        return (stcb);
      } else {
        /* remaining chunks are HMAC checked */
        stcb->asoc.authenticated = 1;
      }
      break;

    default:
    unknown_chunk:
      /* it's an unknown chunk! */
      if ((ch->chunk_type & 0x40) &&
          (stcb != NULL) &&
          (SCTP_GET_STATE(stcb) != SCTP_STATE_EMPTY) &&
          (SCTP_GET_STATE(stcb) != SCTP_STATE_INUSE) &&
          (SCTP_GET_STATE(stcb) != SCTP_STATE_COOKIE_WAIT)) {
        struct sctp_gen_error_cause *cause;
        int len;

        op_err = sctp_get_mbuf_for_msg(sizeof(struct sctp_gen_error_cause),
                                       0, M_NOWAIT, 1, MT_DATA);
        if (op_err != NULL) {
          len = min(SCTP_SIZE32(chk_length), (uint32_t)(length - *offset));
          cause = mtod(op_err, struct sctp_gen_error_cause *);
          cause->code = htons(SCTP_CAUSE_UNRECOG_CHUNK);
          cause->length = htons((uint16_t)(len + sizeof(struct sctp_gen_error_cause)));
          SCTP_BUF_LEN(op_err) = sizeof(struct sctp_gen_error_cause);
          SCTP_BUF_NEXT(op_err) = SCTP_M_COPYM(m, *offset, len, M_NOWAIT);
          if (SCTP_BUF_NEXT(op_err) != NULL) {
#ifdef SCTP_MBUF_LOGGING
            if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_MBUF_LOGGING_ENABLE) {
              sctp_log_mbc(SCTP_BUF_NEXT(op_err), SCTP_MBUF_ICOPY);
            }
#endif
            sctp_queue_op_err(stcb, op_err);
          } else {
            sctp_m_freem(op_err);
          }
        }
      }
      if ((ch->chunk_type & 0x80) == 0) {
        /* discard this packet */
        *offset = length;
        return (stcb);
      } /* else skip this bad chunk and continue... */
      break;
    }    /* switch (ch->chunk_type) */

  next_chunk:
    /* get the next chunk */
    *offset += SCTP_SIZE32(chk_length);
    if (*offset >= length) {
      /* no more data left in the mbuf chain */
      break;
    }
    ch = (struct sctp_chunkhdr *)sctp_m_getptr(m, *offset,
                                               sizeof(struct sctp_chunkhdr), chunk_buf);
    if (ch == NULL) {
      *offset = length;
      return (stcb);
    }
  }      /* while */

  if ((asconf_cnt > 0) && (stcb != NULL)) {
    sctp_send_asconf_ack(stcb);
  }
  return (stcb);
}

/*
 * common input chunk processing (v4 and v6)
 */
void
sctp_common_input_processing(struct mbuf **mm, int iphlen, int offset, int length,
                             struct sockaddr *src, struct sockaddr *dst,
                             struct sctphdr *sh, struct sctp_chunkhdr *ch,
                             uint8_t compute_crc,
                             uint8_t ecn_bits,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                             uint8_t mflowtype, uint32_t mflowid, uint16_t fibnum,
#endif
                             uint32_t vrf_id, uint16_t port)
{
  char msg[SCTP_DIAG_INFO_LEN];
  struct mbuf *m = *mm, *op_err;
  struct sctp_inpcb *inp = NULL, *inp_decr = NULL;
  struct sctp_tcb *stcb = NULL;
  struct sctp_nets *net = NULL;
#if defined(__Userspace__)
  struct socket *upcall_socket = NULL;
#endif
  uint32_t high_tsn;
  uint32_t cksum_in_hdr;
  int un_sent;
  int cnt_ctrl_ready = 0;
  int fwd_tsn_seen = 0, data_processed = 0;
  bool cksum_validated, stcb_looked_up;

  SCTP_STAT_INCR(sctps_recvdatagrams);
#ifdef SCTP_AUDITING_ENABLED
  sctp_audit_log(0xE0, 1);
  sctp_auditing(0, inp, stcb, net);
#endif

  stcb_looked_up = false;
  if (compute_crc != 0) {
    cksum_validated = false;
    cksum_in_hdr = sh->checksum;
    if (cksum_in_hdr != htonl(0)) {
      uint32_t cksum_calculated;

validate_cksum:
      sh->checksum = 0;
      cksum_calculated = sctp_calculate_cksum(m, iphlen);
      sh->checksum = cksum_in_hdr;
      if (cksum_calculated != cksum_in_hdr) {
        if (stcb_looked_up) {
          /*
           * The packet has a zero checksum, which
           * is not the correct CRC, no stcb has
           * been found or an stcb has been found
           * but an incorrect zero checksum is not
           * acceptable.
           */
          KASSERT(cksum_in_hdr == htonl(0),
                  ("cksum in header not zero: %x",
                   ntohl(cksum_in_hdr)));
          if ((inp == NULL) &&
              (SCTP_BASE_SYSCTL(sctp_ootb_with_zero_cksum) == 1)) {
            /*
             * This is an OOTB packet,
             * depending on the sysctl
             * variable, pretend that the
             * checksum is acceptable,
             * to allow an appropriate
             * response (ABORT, for examlpe)
             * to be sent.
             */
            KASSERT(stcb == NULL,
                    ("stcb is %p", stcb));
            SCTP_STAT_INCR(sctps_recvzerocrc);
            goto cksum_validated;
          }
        } else {
          stcb = sctp_findassociation_addr(m, offset, src, dst,
                                           sh, ch, &inp, &net, vrf_id);
        }
        SCTPDBG(SCTP_DEBUG_INPUT1, "Bad cksum in SCTP packet:%x calculated:%x m:%p mlen:%d iphlen:%d\n",
                ntohl(cksum_in_hdr), ntohl(cksum_calculated), (void *)m, length, iphlen);
#if defined(INET) || defined(INET6)
        if ((ch->chunk_type != SCTP_INITIATION) &&
            (net != NULL) && (net->port != port)) {
          if (net->port == 0) {
            /* UDP encapsulation turned on. */
            net->mtu -= sizeof(struct udphdr);
            if (stcb->asoc.smallest_mtu > net->mtu) {
              sctp_pathmtu_adjustment(stcb, net->mtu, true);
            }
          } else if (port == 0) {
            /* UDP encapsulation turned off. */
            net->mtu += sizeof(struct udphdr);
            /* XXX Update smallest_mtu */
          }
          net->port = port;
        }
#endif
#if defined(__FreeBSD__) && !defined(__Userspace__)
        if (net != NULL) {
          net->flowtype = mflowtype;
          net->flowid = mflowid;
        }
        SCTP_PROBE5(receive, NULL, stcb, m, stcb, sh);
#endif
        if ((inp != NULL) && (stcb != NULL)) {
          if (stcb->asoc.pktdrop_supported) {
            sctp_send_packet_dropped(stcb, net, m, length, iphlen, 1);
            sctp_chunk_output(inp, stcb, SCTP_OUTPUT_FROM_INPUT_ERROR, SCTP_SO_NOT_LOCKED);
          }
        } else if ((inp != NULL) && (stcb == NULL)) {
          inp_decr = inp;
        }
        SCTP_STAT_INCR(sctps_badsum);
        SCTP_STAT_INCR_COUNTER32(sctps_checksumerrors);
        goto out;
      } else {
        cksum_validated = true;
      }
    }
    KASSERT(cksum_validated || cksum_in_hdr == htonl(0),
            ("cksum 0x%08x not zero and not validated", ntohl(cksum_in_hdr)));
    if (!cksum_validated) {
      stcb = sctp_findassociation_addr(m, offset, src, dst,
                                       sh, ch, &inp, &net, vrf_id);
      stcb_looked_up = true;
      if (stcb == NULL) {
        goto validate_cksum;
      }
      if (stcb->asoc.rcv_edmid == SCTP_EDMID_NONE) {
        goto validate_cksum;
      }
      KASSERT(stcb->asoc.rcv_edmid == SCTP_EDMID_LOWER_LAYER_DTLS,
        ("Unexpected EDMID %u", stcb->asoc.rcv_edmid));
      SCTP_STAT_INCR(sctps_recvzerocrc);
    }
  }
cksum_validated:
  /* Destination port of 0 is illegal, based on RFC4960. */
  if (sh->dest_port == htons(0)) {
    SCTP_STAT_INCR(sctps_hdrops);
    if ((stcb == NULL) && (inp != NULL)) {
      inp_decr = inp;
    }
    goto out;
  }
  if (!stcb_looked_up) {
    stcb = sctp_findassociation_addr(m, offset, src, dst,
                                     sh, ch, &inp, &net, vrf_id);
  }
#if defined(INET) || defined(INET6)
  if ((ch->chunk_type != SCTP_INITIATION) &&
      (net != NULL) && (net->port != port)) {
    if (net->port == 0) {
      /* UDP encapsulation turned on. */
      net->mtu -= sizeof(struct udphdr);
      if (stcb->asoc.smallest_mtu > net->mtu) {
        sctp_pathmtu_adjustment(stcb, net->mtu, true);
      }
    } else if (port == 0) {
      /* UDP encapsulation turned off. */
      net->mtu += sizeof(struct udphdr);
      /* XXX Update smallest_mtu */
    }
    net->port = port;
  }
#endif
#if defined(__FreeBSD__) && !defined(__Userspace__)
  if (net != NULL) {
    net->flowtype = mflowtype;
    net->flowid = mflowid;
  }
#endif
  if (inp == NULL) {
    SCTP_STAT_INCR(sctps_noport);
#if defined(__FreeBSD__) && !defined(__Userspace__)
    SCTP_PROBE5(receive, NULL, stcb, m, stcb, sh);
    if (badport_bandlim(BANDLIM_SCTP_OOTB) < 0) {
      goto out;
    }
#endif
    if (ch->chunk_type == SCTP_SHUTDOWN_ACK) {
      SCTP_STAT_INCR_COUNTER64(sctps_incontrolchunks);
      sctp_send_shutdown_complete2(src, dst, sh,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                                   mflowtype, mflowid, fibnum,
#endif
                                   vrf_id, port);
      goto out;
    }
    if (ch->chunk_type == SCTP_SHUTDOWN_COMPLETE) {
      SCTP_STAT_INCR_COUNTER64(sctps_incontrolchunks);
      goto out;
    }
    if (ch->chunk_type != SCTP_ABORT_ASSOCIATION) {
      if ((SCTP_BASE_SYSCTL(sctp_blackhole) == 0) ||
          ((SCTP_BASE_SYSCTL(sctp_blackhole) == 1) &&
           (ch->chunk_type != SCTP_INIT))) {
        op_err = sctp_generate_cause(SCTP_BASE_SYSCTL(sctp_diag_info_code),
                                     "Out of the blue");
        sctp_send_abort(m, iphlen, src, dst,
                        sh, 0, op_err,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                        mflowtype, mflowid, fibnum,
#endif
                        vrf_id, port);
      }
    }
    goto out;
  } else if (stcb == NULL) {
    inp_decr = inp;
  }
  SCTPDBG(SCTP_DEBUG_INPUT1, "Ok, Common input processing called, m:%p iphlen:%d offset:%d length:%d stcb:%p\n",
    (void *)m, iphlen, offset, length, (void *)stcb);
  if (stcb) {
    /* always clear this before beginning a packet */
    stcb->asoc.authenticated = 0;
    stcb->asoc.seen_a_sack_this_pkt = 0;
    SCTPDBG(SCTP_DEBUG_INPUT1, "stcb:%p state:%x\n",
      (void *)stcb, stcb->asoc.state);

    if ((stcb->asoc.state & SCTP_STATE_WAS_ABORTED) ||
        (stcb->asoc.state & SCTP_STATE_ABOUT_TO_BE_FREED)) {
      /*-
       * If we hit here, we had a ref count
       * up when the assoc was aborted and the
       * timer is clearing out the assoc, we should
       * NOT respond to any packet.. its OOTB.
       */
      SCTP_TCB_UNLOCK(stcb);
      stcb = NULL;
#if defined(__FreeBSD__) && !defined(__Userspace__)
      SCTP_PROBE5(receive, NULL, stcb, m, stcb, sh);
#endif
      SCTP_SNPRINTF(msg, sizeof(msg), "OOTB, %s:%d at %s", __FILE__, __LINE__, __func__);
      op_err = sctp_generate_cause(SCTP_BASE_SYSCTL(sctp_diag_info_code),
                                   msg);
      sctp_handle_ootb(m, iphlen, offset, src, dst, sh, inp, op_err,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                       mflowtype, mflowid, inp->fibnum,
#endif
                       vrf_id, port);
      goto out;
    }
  }
#if defined(__Userspace__)
  if ((stcb != NULL) &&
      ((stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE) == 0) &&
      (stcb->sctp_socket != NULL)) {
    if (stcb->sctp_socket->so_head != NULL) {
      upcall_socket = stcb->sctp_socket->so_head;
    } else {
      upcall_socket = stcb->sctp_socket;
    }
    SOCK_LOCK(upcall_socket);
    soref(upcall_socket);
    SOCK_UNLOCK(upcall_socket);
  }
#endif
  if (IS_SCTP_CONTROL(ch)) {
    /* process the control portion of the SCTP packet */
    /* sa_ignore NO_NULL_CHK */
    stcb = sctp_process_control(m, iphlen, &offset, length,
                                src, dst, sh, ch,
                                inp, stcb, &net, &fwd_tsn_seen,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                                mflowtype, mflowid, fibnum,
#endif
                                vrf_id, port);
    if (stcb) {
      /* This covers us if the cookie-echo was there
       * and it changes our INP.
       */
      inp = stcb->sctp_ep;
#if defined(INET) || defined(INET6)
      if ((ch->chunk_type != SCTP_INITIATION) &&
          (net != NULL) && (net->port != port)) {
        if (net->port == 0) {
          /* UDP encapsulation turned on. */
          net->mtu -= sizeof(struct udphdr);
          if (stcb->asoc.smallest_mtu > net->mtu) {
            sctp_pathmtu_adjustment(stcb, net->mtu, true);
          }
        } else if (port == 0) {
          /* UDP encapsulation turned off. */
          net->mtu += sizeof(struct udphdr);
          /* XXX Update smallest_mtu */
        }
        net->port = port;
      }
#endif
    }
  } else {
    /*
     * no control chunks, so pre-process DATA chunks (these
     * checks are taken care of by control processing)
     */

    /*
     * if DATA only packet, and auth is required, then punt...
     * can't have authenticated without any AUTH (control)
     * chunks
     */
    if ((stcb != NULL) &&
        sctp_auth_is_required_chunk(SCTP_DATA, stcb->asoc.local_auth_chunks)) {
      /* "silently" ignore */
#if defined(__FreeBSD__) && !defined(__Userspace__)
      SCTP_PROBE5(receive, NULL, stcb, m, stcb, sh);
#endif
      SCTP_STAT_INCR(sctps_recvauthmissing);
      goto out;
    }
    if (stcb == NULL) {
      /* out of the blue DATA chunk */
#if defined(__FreeBSD__) && !defined(__Userspace__)
      SCTP_PROBE5(receive, NULL, NULL, m, NULL, sh);
#endif
      SCTP_SNPRINTF(msg, sizeof(msg), "OOTB, %s:%d at %s", __FILE__, __LINE__, __func__);
      op_err = sctp_generate_cause(SCTP_BASE_SYSCTL(sctp_diag_info_code),
                                   msg);
      sctp_handle_ootb(m, iphlen, offset, src, dst, sh, inp, op_err,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                       mflowtype, mflowid, fibnum,
#endif
           vrf_id, port);
      goto out;
    }
    if (stcb->asoc.my_vtag != ntohl(sh->v_tag)) {
      /* v_tag mismatch! */
#if defined(__FreeBSD__) && !defined(__Userspace__)
      SCTP_PROBE5(receive, NULL, stcb, m, stcb, sh);
#endif
      SCTP_STAT_INCR(sctps_badvtag);
      goto out;
    }
  }

#if defined(__FreeBSD__) && !defined(__Userspace__)
  SCTP_PROBE5(receive, NULL, stcb, m, stcb, sh);
#endif
  if (stcb == NULL) {
    /*
     * no valid TCB for this packet, or we found it's a bad
     * packet while processing control, or we're done with this
     * packet (done or skip rest of data), so we drop it...
     */
    goto out;
  }
#if defined(__Userspace__)
  if ((upcall_socket == NULL) &&
      ((stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE) == 0) &&
      (stcb->sctp_socket != NULL)) {
    if (stcb->sctp_socket->so_head != NULL) {
      upcall_socket = stcb->sctp_socket->so_head;
    } else {
      upcall_socket = stcb->sctp_socket;
    }
    SOCK_LOCK(upcall_socket);
    soref(upcall_socket);
    SOCK_UNLOCK(upcall_socket);
  }
#endif

  /*
   * DATA chunk processing
   */
  /* plow through the data chunks while length > offset */

  /*
   * Rest should be DATA only.  Check authentication state if AUTH for
   * DATA is required.
   */
  if ((length > offset) &&
      (stcb != NULL) &&
      sctp_auth_is_required_chunk(SCTP_DATA, stcb->asoc.local_auth_chunks) &&
      !stcb->asoc.authenticated) {
    /* "silently" ignore */
    SCTP_STAT_INCR(sctps_recvauthmissing);
    SCTPDBG(SCTP_DEBUG_AUTH1,
      "Data chunk requires AUTH, skipped\n");
    goto trigger_send;
  }
  if (length > offset) {
    int retval;

    /*
     * First check to make sure our state is correct. We would
     * not get here unless we really did have a tag, so we don't
     * abort if this happens, just dump the chunk silently.
     */
    switch (SCTP_GET_STATE(stcb)) {
    case SCTP_STATE_COOKIE_ECHOED:
      /*
       * we consider data with valid tags in this state
       * shows us the cookie-ack was lost. Imply it was
       * there.
       */
      sctp_handle_cookie_ack((struct sctp_cookie_ack_chunk *)ch, stcb, net);
      break;
    case SCTP_STATE_COOKIE_WAIT:
      /*
       * We consider OOTB any data sent during asoc setup.
       */
      SCTP_SNPRINTF(msg, sizeof(msg), "OOTB, %s:%d at %s", __FILE__, __LINE__, __func__);
      op_err = sctp_generate_cause(SCTP_BASE_SYSCTL(sctp_diag_info_code),
                                   msg);
      sctp_handle_ootb(m, iphlen, offset, src, dst, sh, inp, op_err,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                       mflowtype, mflowid, inp->fibnum,
#endif
           vrf_id, port);
      goto out;
      /*sa_ignore NOTREACHED*/
      break;
    case SCTP_STATE_EMPTY: /* should not happen */
    case SCTP_STATE_INUSE: /* should not happen */
    case SCTP_STATE_SHUTDOWN_RECEIVED: /* This is a peer error */
    case SCTP_STATE_SHUTDOWN_ACK_SENT:
    default:
      goto out;
      /*sa_ignore NOTREACHED*/
      break;
    case SCTP_STATE_OPEN:
    case SCTP_STATE_SHUTDOWN_SENT:
      break;
    }
    /* plow through the data chunks while length > offset */
    retval = sctp_process_data(mm, iphlen, &offset, length,
                               inp, stcb, net, &high_tsn);
    if (retval == 2) {
      /*
       * The association aborted, NO UNLOCK needed since
       * the association is destroyed.
       */
      stcb = NULL;
      goto out;
    }
    if (retval == 0) {
      data_processed = 1;
    }
    /*
     * Anything important needs to have been m_copy'ed in
     * process_data
     */
  }

  /* take care of ecn */
  if ((data_processed == 1) &&
      (stcb->asoc.ecn_supported == 1) &&
      ((ecn_bits & SCTP_CE_BITS) == SCTP_CE_BITS)) {
    /* Yep, we need to add a ECNE */
    sctp_send_ecn_echo(stcb, net, high_tsn);
  }

  if ((data_processed == 0) && (fwd_tsn_seen)) {
    int was_a_gap;
    uint32_t highest_tsn;

    if (SCTP_TSN_GT(stcb->asoc.highest_tsn_inside_nr_map, stcb->asoc.highest_tsn_inside_map)) {
      highest_tsn = stcb->asoc.highest_tsn_inside_nr_map;
    } else {
      highest_tsn = stcb->asoc.highest_tsn_inside_map;
    }
    was_a_gap = SCTP_TSN_GT(highest_tsn, stcb->asoc.cumulative_tsn);
    stcb->asoc.send_sack = 1;
    sctp_sack_check(stcb, was_a_gap);
  } else if (fwd_tsn_seen) {
    stcb->asoc.send_sack = 1;
  }
  /* trigger send of any chunks in queue... */
trigger_send:
#ifdef SCTP_AUDITING_ENABLED
  sctp_audit_log(0xE0, 2);
  sctp_auditing(1, inp, stcb, net);
#endif
  SCTPDBG(SCTP_DEBUG_INPUT1,
    "Check for chunk output prw:%d tqe:%d tf=%d\n",
    stcb->asoc.peers_rwnd,
    TAILQ_EMPTY(&stcb->asoc.control_send_queue),
    stcb->asoc.total_flight);
  un_sent = (stcb->asoc.total_output_queue_size - stcb->asoc.total_flight);
  if (!TAILQ_EMPTY(&stcb->asoc.control_send_queue)) {
    cnt_ctrl_ready = stcb->asoc.ctrl_queue_cnt - stcb->asoc.ecn_echo_cnt_onq;
  }
  if (!TAILQ_EMPTY(&stcb->asoc.asconf_send_queue) ||
      cnt_ctrl_ready ||
      stcb->asoc.trigger_reset ||
      ((un_sent > 0) &&
       (stcb->asoc.peers_rwnd > 0 || stcb->asoc.total_flight == 0))) {
    SCTPDBG(SCTP_DEBUG_INPUT3, "Calling chunk OUTPUT\n");
    sctp_chunk_output(inp, stcb, SCTP_OUTPUT_FROM_CONTROL_PROC, SCTP_SO_NOT_LOCKED);
    SCTPDBG(SCTP_DEBUG_INPUT3, "chunk OUTPUT returns\n");
  }
#ifdef SCTP_AUDITING_ENABLED
  sctp_audit_log(0xE0, 3);
  sctp_auditing(2, inp, stcb, net);
#endif
 out:
  if (stcb != NULL) {
    SCTP_TCB_UNLOCK(stcb);
  }
#if defined(__Userspace__)
  if (upcall_socket != NULL) {
    if (upcall_socket->so_upcall != NULL) {
      if (soreadable(upcall_socket) ||
          sowriteable(upcall_socket) ||
          upcall_socket->so_error) {
        (*upcall_socket->so_upcall)(upcall_socket, upcall_socket->so_upcallarg, M_NOWAIT);
      }
    }
    ACCEPT_LOCK();
    SOCK_LOCK(upcall_socket);
    sorele(upcall_socket);
  }
#endif
  if (inp_decr != NULL) {
    /* reduce ref-count */
    SCTP_INP_WLOCK(inp_decr);
    SCTP_INP_DECR_REF(inp_decr);
    SCTP_INP_WUNLOCK(inp_decr);
  }
  return;
}

#ifdef INET
#if !defined(__Userspace__)
void
sctp_input_with_port(struct mbuf *i_pak, int off, uint16_t port)
{
  struct mbuf *m;
  int iphlen;
  uint32_t vrf_id = 0;
  uint8_t ecn_bits;
  struct sockaddr_in src, dst;
  struct ip *ip;
  struct sctphdr *sh;
  struct sctp_chunkhdr *ch;
  int length, offset;
  uint8_t compute_crc;
#if defined(__FreeBSD__) && !defined(__Userspace__)
  uint32_t mflowid;
  uint8_t mflowtype;
  uint16_t fibnum;
#endif
#if defined(__Userspace__)
  uint16_t port = 0;
#endif

  iphlen = off;
  if (SCTP_GET_PKT_VRFID(i_pak, vrf_id)) {
    SCTP_RELEASE_PKT(i_pak);
    return;
  }
  m = SCTP_HEADER_TO_CHAIN(i_pak);
#ifdef SCTP_MBUF_LOGGING
  /* Log in any input mbufs */
  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_MBUF_LOGGING_ENABLE) {
    sctp_log_mbc(m, SCTP_MBUF_INPUT);
  }
#endif
#ifdef SCTP_PACKET_LOGGING
  if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_LAST_PACKET_TRACING) {
    sctp_packet_log(m);
  }
#endif
#if defined(__FreeBSD__) && !defined(__Userspace__)
  SCTPDBG(SCTP_DEBUG_CRCOFFLOAD,
          "sctp_input(): Packet of length %d received on %s with csum_flags 0x%b.\n",
          m->m_pkthdr.len,
          if_name(m->m_pkthdr.rcvif),
          (int)m->m_pkthdr.csum_flags, CSUM_BITS);
#endif
#if defined(__APPLE__) && !defined(__Userspace__)
  SCTPDBG(SCTP_DEBUG_CRCOFFLOAD,
          "sctp_input(): Packet of length %d received on %s%d with csum_flags 0x%x.\n",
          m->m_pkthdr.len,
          m->m_pkthdr.rcvif->if_name,
          m->m_pkthdr.rcvif->if_unit,
          m->m_pkthdr.csum_flags);
#endif
#if defined(_WIN32) && !defined(__Userspace__)
  SCTPDBG(SCTP_DEBUG_CRCOFFLOAD,
          "sctp_input(): Packet of length %d received on %s with csum_flags 0x%x.\n",
          m->m_pkthdr.len,
          m->m_pkthdr.rcvif->if_xname,
          m->m_pkthdr.csum_flags);
#endif
#if defined(__FreeBSD__) && !defined(__Userspace__)
  mflowid = m->m_pkthdr.flowid;
  mflowtype = M_HASHTYPE_GET(m);
  fibnum = M_GETFIB(m);
#endif
  SCTP_STAT_INCR(sctps_recvpackets);
  SCTP_STAT_INCR_COUNTER64(sctps_inpackets);
  /* Get IP, SCTP, and first chunk header together in the first mbuf. */
  offset = iphlen + sizeof(struct sctphdr) + sizeof(struct sctp_chunkhdr);
  if (SCTP_BUF_LEN(m) < offset) {
    if ((m = m_pullup(m, offset)) == NULL) {
      SCTP_STAT_INCR(sctps_hdrops);
      return;
    }
  }
  ip = mtod(m, struct ip *);
  sh = (struct sctphdr *)((caddr_t)ip + iphlen);
  ch = (struct sctp_chunkhdr *)((caddr_t)sh + sizeof(struct sctphdr));
  offset -= sizeof(struct sctp_chunkhdr);
  memset(&src, 0, sizeof(struct sockaddr_in));
  src.sin_family = AF_INET;
#ifdef HAVE_SIN_LEN
  src.sin_len = sizeof(struct sockaddr_in);
#endif
  src.sin_port = sh->src_port;
  src.sin_addr = ip->ip_src;
  memset(&dst, 0, sizeof(struct sockaddr_in));
  dst.sin_family = AF_INET;
#ifdef HAVE_SIN_LEN
  dst.sin_len = sizeof(struct sockaddr_in);
#endif
  dst.sin_port = sh->dest_port;
  dst.sin_addr = ip->ip_dst;
#if defined(_WIN32) && !defined(__Userspace__)
  NTOHS(ip->ip_len);
#endif
#if defined(__linux__) || (defined(_WIN32) && defined(__Userspace__))
  ip->ip_len = ntohs(ip->ip_len);
#endif
#if defined(__Userspace__)
#if defined(__linux__) || defined(_WIN32)
  length = ip->ip_len;
#else
  length = ip->ip_len + iphlen;
#endif
#elif defined(__FreeBSD__)
  length = ntohs(ip->ip_len);
#elif defined(__APPLE__)
  length = ip->ip_len + iphlen;
#else
  length = ip->ip_len;
#endif
  /* Validate mbuf chain length with IP payload length. */
  if (SCTP_HEADER_LEN(m) != length) {
    SCTPDBG(SCTP_DEBUG_INPUT1,
            "sctp_input() length:%d reported length:%d\n", length, SCTP_HEADER_LEN(m));
    SCTP_STAT_INCR(sctps_hdrops);
    goto out;
  }
  /* SCTP does not allow broadcasts or multicasts */
  if (IN_MULTICAST(ntohl(dst.sin_addr.s_addr))) {
    goto out;
  }
  if (SCTP_IS_IT_BROADCAST(dst.sin_addr, m)) {
    goto out;
  }
  ecn_bits = ip->ip_tos;
#if defined(__FreeBSD__) && !defined(__Userspace__)
  if (m->m_pkthdr.csum_flags & (CSUM_SCTP_VALID | CSUM_IP_SCTP)) {
    /*
     * Packet with CSUM_IP_SCTP were sent from local host using
     * checksum offloading. Checksum not required.
     */
    SCTP_STAT_INCR(sctps_recvhwcrc);
    compute_crc = 0;
  } else {
#else
  if (SCTP_BASE_SYSCTL(sctp_no_csum_on_loopback) &&
      ((src.sin_addr.s_addr == dst.sin_addr.s_addr) ||
       (SCTP_IS_IT_LOOPBACK(m)))) {
    SCTP_STAT_INCR(sctps_recvhwcrc);
    compute_crc = 0;
  } else {
#endif
    SCTP_STAT_INCR(sctps_recvswcrc);
    compute_crc = 1;
  }
  sctp_common_input_processing(&m, iphlen, offset, length,
                               (struct sockaddr *)&src,
                               (struct sockaddr *)&dst,
                               sh, ch,
                               compute_crc,
                               ecn_bits,
#if defined(__FreeBSD__) && !defined(__Userspace__)
                               mflowtype, mflowid, fibnum,
#endif
                               vrf_id, port);
 out:
  if (m) {
    sctp_m_freem(m);
  }
  return;
}

#if defined(__FreeBSD__) && !defined(__Userspace__)
#if defined(SCTP_MCORE_INPUT) && defined(SMP)
extern int *sctp_cpuarry;
#endif
#endif

#if defined(__FreeBSD__) && !defined(__Userspace__)
int
sctp_input(struct mbuf **mp, int *offp, int proto SCTP_UNUSED)
{
  struct mbuf *m;
  int off;

  m = *mp;
  off = *offp;
#else
void
sctp_input(struct mbuf *m, int off)
{
#endif
#if defined(__FreeBSD__) && !defined(__Userspace__)
#if defined(SCTP_MCORE_INPUT) && defined(SMP)
  if (mp_ncpus > 1) {
    struct ip *ip;
    struct sctphdr *sh;
    int offset;
    int cpu_to_use;
    uint32_t flowid, tag;

    if (M_HASHTYPE_GET(m) != M_HASHTYPE_NONE) {
      flowid = m->m_pkthdr.flowid;
    } else {
      /* No flow id built by lower layers
       * fix it so we create one.
       */
      offset = off + sizeof(struct sctphdr);
      if (SCTP_BUF_LEN(m) < offset) {
        if ((m = m_pullup(m, offset)) == NULL) {
          SCTP_STAT_INCR(sctps_hdrops);
          return (IPPROTO_DONE);
        }
      }
      ip = mtod(m, struct ip *);
      sh = (struct sctphdr *)((caddr_t)ip + off);
      tag = htonl(sh->v_tag);
      flowid = tag ^ ntohs(sh->dest_port) ^ ntohs(sh->src_port);
      m->m_pkthdr.flowid = flowid;
      M_HASHTYPE_SET(m, M_HASHTYPE_OPAQUE_HASH);
    }
    cpu_to_use = sctp_cpuarry[flowid % mp_ncpus];
    sctp_queue_to_mcore(m, off, cpu_to_use);
    return (IPPROTO_DONE);
  }
#endif
#endif
  sctp_input_with_port(m, off, 0);
#if defined(__FreeBSD__) && !defined(__Userspace__)
  return (IPPROTO_DONE);
#endif
}
#endif
#endif

Coverage Report

Created: 2025-10-10 06:38