sctp_timer.c

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/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 2001-2007, 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
 
#define _IP_VHL
#include <netinet/sctp_os.h>
#include <netinet/sctp_pcb.h>
#ifdef INET6
#endif
#include <netinet/sctp_var.h>
#include <netinet/sctp_sysctl.h>
#include <netinet/sctp_timer.h>
#include <netinet/sctputil.h>
#include <netinet/sctp_output.h>
#include <netinet/sctp_header.h>
#include <netinet/sctp_indata.h>
#include <netinet/sctp_asconf.h>
#include <netinet/sctp_input.h>
#include <netinet/sctp.h>
#include <netinet/sctp_uio.h>
#if defined(INET) || defined(INET6)
#include <netinet/udp.h>
#endif
 
void
sctp_audit_retranmission_queue(struct sctp_association *asoc)
{
        struct sctp_tmit_chunk *chk;
 
        SCTPDBG(SCTP_DEBUG_TIMER4, "Audit invoked on send queue cnt:%d onqueue:%d\n",
            asoc->sent_queue_retran_cnt,
            asoc->sent_queue_cnt);
        asoc->sent_queue_retran_cnt = 0;
        asoc->sent_queue_cnt = 0;
        TAILQ_FOREACH(chk, &asoc->sent_queue, sctp_next) {
                if (chk->sent == SCTP_DATAGRAM_RESEND) {
                        sctp_ucount_incr(asoc->sent_queue_retran_cnt);
                }
                asoc->sent_queue_cnt++;
        }
        TAILQ_FOREACH(chk, &asoc->control_send_queue, sctp_next) {
                if (chk->sent == SCTP_DATAGRAM_RESEND) {
                        sctp_ucount_incr(asoc->sent_queue_retran_cnt);
                }
        }
        TAILQ_FOREACH(chk, &asoc->asconf_send_queue, sctp_next) {
                if (chk->sent == SCTP_DATAGRAM_RESEND) {
                        sctp_ucount_incr(asoc->sent_queue_retran_cnt);
                }
        }
        SCTPDBG(SCTP_DEBUG_TIMER4, "Audit completes retran:%d onqueue:%d\n",
            asoc->sent_queue_retran_cnt,
            asoc->sent_queue_cnt);
}
 
static int
sctp_threshold_management(struct sctp_inpcb *inp, struct sctp_tcb *stcb,
    struct sctp_nets *net, uint16_t threshold)
{
        if (net) {
                net->error_count++;
                SCTPDBG(SCTP_DEBUG_TIMER4, "Error count for %p now %d thresh:%d\n",
                    (void *)net, net->error_count,
                    net->failure_threshold);
                if (net->error_count > net->failure_threshold) {
                        /* We had a threshold failure */
                        if (net->dest_state & SCTP_ADDR_REACHABLE) {
                                net->dest_state &= ~SCTP_ADDR_REACHABLE;
                                net->dest_state &= ~SCTP_ADDR_REQ_PRIMARY;
                                net->dest_state &= ~SCTP_ADDR_PF;
                                sctp_ulp_notify(SCTP_NOTIFY_INTERFACE_DOWN,
                                    stcb, 0,
                                    (void *)net, SCTP_SO_NOT_LOCKED);
                        }
                } else if ((net->pf_threshold < net->failure_threshold) &&
                    (net->error_count > net->pf_threshold)) {
                        if (!(net->dest_state & SCTP_ADDR_PF)) {
                                net->dest_state |= SCTP_ADDR_PF;
                                net->last_active = sctp_get_tick_count();
                                sctp_send_hb(stcb, net, SCTP_SO_NOT_LOCKED);
                                sctp_timer_stop(SCTP_TIMER_TYPE_HEARTBEAT,
                                    inp, stcb, net,
                                    SCTP_FROM_SCTP_TIMER + SCTP_LOC_1);
                                sctp_timer_start(SCTP_TIMER_TYPE_HEARTBEAT, inp, stcb, net);
                        }
                }
        }
        if (stcb == NULL)
                return (0);
 
        if (net) {
                if ((net->dest_state & SCTP_ADDR_UNCONFIRMED) == 0) {
                        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_THRESHOLD_LOGGING) {
                                sctp_misc_ints(SCTP_THRESHOLD_INCR,
                                    stcb->asoc.overall_error_count,
                                    (stcb->asoc.overall_error_count + 1),
                                    SCTP_FROM_SCTP_TIMER,
                                    __LINE__);
                        }
                        stcb->asoc.overall_error_count++;
                }
        } else {
                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_THRESHOLD_LOGGING) {
                        sctp_misc_ints(SCTP_THRESHOLD_INCR,
                            stcb->asoc.overall_error_count,
                            (stcb->asoc.overall_error_count + 1),
                            SCTP_FROM_SCTP_TIMER,
                            __LINE__);
                }
                stcb->asoc.overall_error_count++;
        }
        SCTPDBG(SCTP_DEBUG_TIMER4, "Overall error count for %p now %d thresh:%u state:%x\n",
            (void *)&stcb->asoc, stcb->asoc.overall_error_count,
            (uint32_t)threshold,
            ((net == NULL) ? (uint32_t)0 : (uint32_t)net->dest_state));
        /*
         * We specifically do not do >= to give the assoc one more change
         * before we fail it.
         */
        if (stcb->asoc.overall_error_count > threshold) {
                /* Abort notification sends a ULP notify */
                struct mbuf *op_err;
 
                op_err = sctp_generate_cause(SCTP_BASE_SYSCTL(sctp_diag_info_code),
                    "Association error counter exceeded");
                inp->last_abort_code = SCTP_FROM_SCTP_TIMER + SCTP_LOC_2;
                sctp_abort_an_association(inp, stcb, op_err, true, SCTP_SO_NOT_LOCKED);
                return (1);
        }
        return (0);
}
 
/*
 * sctp_find_alternate_net() returns a non-NULL pointer as long as there
 * exists nets, which are not being deleted.
 */
struct sctp_nets *
sctp_find_alternate_net(struct sctp_tcb *stcb,
    struct sctp_nets *net,
    int mode)
{
        /* Find and return an alternate network if possible */
        struct sctp_nets *alt, *mnet, *min_errors_net = NULL, *max_cwnd_net = NULL;
        bool looped;
 
        /* JRS 5/14/07 - Initialize min_errors to an impossible value. */
        int min_errors = -1;
        uint32_t max_cwnd = 0;
 
        if (stcb->asoc.numnets == 1) {
                /* No selection can be made. */
                return (TAILQ_FIRST(&stcb->asoc.nets));
        }
        /*
         * JRS 5/14/07 - If mode is set to 2, use the CMT PF find alternate
         * net algorithm. This algorithm chooses the active destination (not
         * in PF state) with the largest cwnd value. If all destinations are
         * in PF state, unreachable, or unconfirmed, choose the desination
         * that is in PF state with the lowest error count. In case of a
         * tie, choose the destination that was most recently active.
         */
        if (mode == 2) {
                TAILQ_FOREACH(mnet, &stcb->asoc.nets, sctp_next) {
                        /*
                         * JRS 5/14/07 - If the destination is unreachable
                         * or unconfirmed, skip it.
                         */
                        if (((mnet->dest_state & SCTP_ADDR_REACHABLE) != SCTP_ADDR_REACHABLE) ||
                            (mnet->dest_state & SCTP_ADDR_UNCONFIRMED)) {
                                continue;
                        }
                        /*
                         * JRS 5/14/07 -  If the destination is reachable
                         * but in PF state, compare the error count of the
                         * destination to the minimum error count seen thus
                         * far. Store the destination with the lower error
                         * count.  If the error counts are equal, store the
                         * destination that was most recently active.
                         */
                        if (mnet->dest_state & SCTP_ADDR_PF) {
                                /*
                                 * JRS 5/14/07 - If the destination under
                                 * consideration is the current destination,
                                 * work as if the error count is one higher.
                                 * The actual error count will not be
                                 * incremented until later in the t3
                                 * handler.
                                 */
                                if (mnet == net) {
                                        if (min_errors == -1) {
                                                min_errors = mnet->error_count + 1;
                                                min_errors_net = mnet;
                                        } else if (mnet->error_count + 1 < min_errors) {
                                                min_errors = mnet->error_count + 1;
                                                min_errors_net = mnet;
                                        } else if (mnet->error_count + 1 == min_errors
                                            && mnet->last_active > min_errors_net->last_active) {
                                                min_errors_net = mnet;
                                                min_errors = mnet->error_count + 1;
                                        }
                                        continue;
                                } else {
                                        if (min_errors == -1) {
                                                min_errors = mnet->error_count;
                                                min_errors_net = mnet;
                                        } else if (mnet->error_count < min_errors) {
                                                min_errors = mnet->error_count;
                                                min_errors_net = mnet;
                                        } else if (mnet->error_count == min_errors
                                            && mnet->last_active > min_errors_net->last_active) {
                                                min_errors_net = mnet;
                                                min_errors = mnet->error_count;
                                        }
                                        continue;
                                }
                        }
                        /*
                         * JRS 5/14/07 - If the destination is reachable and
                         * not in PF state, compare the cwnd of the
                         * destination to the highest cwnd seen thus far.
                         * Store the destination with the higher cwnd value.
                         * If the cwnd values are equal, randomly choose one
                         * of the two destinations.
                         */
                        if (max_cwnd < mnet->cwnd) {
                                max_cwnd_net = mnet;
                                max_cwnd = mnet->cwnd;
                        } else if (max_cwnd == mnet->cwnd) {
                                uint32_t rndval;
                                uint8_t this_random;
 
                                if (stcb->asoc.hb_random_idx > 3) {
                                        rndval = sctp_select_initial_TSN(&stcb->sctp_ep->sctp_ep);
                                        memcpy(stcb->asoc.hb_random_values, &rndval, sizeof(stcb->asoc.hb_random_values));
                                        this_random = stcb->asoc.hb_random_values[0];
                                        stcb->asoc.hb_random_idx++;
                                        stcb->asoc.hb_ect_randombit = 0;
                                } else {
                                        this_random = stcb->asoc.hb_random_values[stcb->asoc.hb_random_idx];
                                        stcb->asoc.hb_random_idx++;
                                        stcb->asoc.hb_ect_randombit = 0;
                                }
                                if (this_random % 2 == 1) {
                                        max_cwnd_net = mnet;
                                        max_cwnd = mnet->cwnd;  /* Useless? */
                                }
                        }
                }
                if (max_cwnd_net == NULL) {
                        if (min_errors_net == NULL) {
                                return (net);
                        }
                        return (min_errors_net);
                } else {
                        return (max_cwnd_net);
                }
        }                       /* JRS 5/14/07 - If mode is set to 1, use the
                                 * CMT policy for choosing an alternate net. */
        else if (mode == 1) {
                TAILQ_FOREACH(mnet, &stcb->asoc.nets, sctp_next) {
                        if (((mnet->dest_state & SCTP_ADDR_REACHABLE) != SCTP_ADDR_REACHABLE) ||
                            (mnet->dest_state & SCTP_ADDR_UNCONFIRMED)) {
                                /*
                                 * will skip ones that are not-reachable or
                                 * unconfirmed
                                 */
                                continue;
                        }
                        if (max_cwnd < mnet->cwnd) {
                                max_cwnd_net = mnet;
                                max_cwnd = mnet->cwnd;
                        } else if (max_cwnd == mnet->cwnd) {
                                uint32_t rndval;
                                uint8_t this_random;
 
                                if (stcb->asoc.hb_random_idx > 3) {
                                        rndval = sctp_select_initial_TSN(&stcb->sctp_ep->sctp_ep);
                                        memcpy(stcb->asoc.hb_random_values, &rndval,
                                            sizeof(stcb->asoc.hb_random_values));
                                        this_random = stcb->asoc.hb_random_values[0];
                                        stcb->asoc.hb_random_idx = 0;
                                        stcb->asoc.hb_ect_randombit = 0;
                                } else {
                                        this_random = stcb->asoc.hb_random_values[stcb->asoc.hb_random_idx];
                                        stcb->asoc.hb_random_idx++;
                                        stcb->asoc.hb_ect_randombit = 0;
                                }
                                if (this_random % 2) {
                                        max_cwnd_net = mnet;
                                        max_cwnd = mnet->cwnd;
                                }
                        }
                }
                if (max_cwnd_net) {
                        return (max_cwnd_net);
                }
        }
        /* Look for an alternate net, which is active. */
        if ((net != NULL) && ((net->dest_state & SCTP_ADDR_BEING_DELETED) == 0)) {
                alt = TAILQ_NEXT(net, sctp_next);
        } else {
                alt = TAILQ_FIRST(&stcb->asoc.nets);
        }
        looped = false;
        for (;;) {
                if (alt == NULL) {
                        if (!looped) {
                                alt = TAILQ_FIRST(&stcb->asoc.nets);
                                looped = true;
                        }
                        /* Definitely out of candidates. */
                        if (alt == NULL) {
                                break;
                        }
                }
                if (alt->ro.ro_nh == NULL) {
                        if (alt->ro._s_addr) {
                                sctp_free_ifa(alt->ro._s_addr);
                                alt->ro._s_addr = NULL;
                        }
                        alt->src_addr_selected = 0;
                }
                if (((alt->dest_state & SCTP_ADDR_REACHABLE) == SCTP_ADDR_REACHABLE) &&
                    (alt->ro.ro_nh != NULL) &&
                    (!(alt->dest_state & SCTP_ADDR_UNCONFIRMED)) &&
                    (alt != net)) {
                        /* Found an alternate net, which is reachable. */
                        break;
                }
                alt = TAILQ_NEXT(alt, sctp_next);
        }
 
        if (alt == NULL) {
                /*
                 * In case no active alternate net has been found, look for
                 * an alternate net, which is confirmed.
                 */
                if ((net != NULL) && ((net->dest_state & SCTP_ADDR_BEING_DELETED) == 0)) {
                        alt = TAILQ_NEXT(net, sctp_next);
                } else {
                        alt = TAILQ_FIRST(&stcb->asoc.nets);
                }
                looped = false;
                for (;;) {
                        if (alt == NULL) {
                                if (!looped) {
                                        alt = TAILQ_FIRST(&stcb->asoc.nets);
                                        looped = true;
                                }
                                /* Definitely out of candidates. */
                                if (alt == NULL) {
                                        break;
                                }
                        }
                        if ((!(alt->dest_state & SCTP_ADDR_UNCONFIRMED)) &&
                            (alt != net)) {
                                /*
                                 * Found an alternate net, which is
                                 * confirmed.
                                 */
                                break;
                        }
                        alt = TAILQ_NEXT(alt, sctp_next);
                }
        }
        if (alt == NULL) {
                /*
                 * In case no confirmed alternate net has been found, just
                 * return net, if it is not being deleted. In the other case
                 * just return the first net.
                 */
                if ((net != NULL) && ((net->dest_state & SCTP_ADDR_BEING_DELETED) == 0)) {
                        alt = net;
                }
                if (alt == NULL) {
                        alt = TAILQ_FIRST(&stcb->asoc.nets);
                }
        }
        return (alt);
}
 
static void
sctp_backoff_on_timeout(struct sctp_tcb *stcb,
    struct sctp_nets *net,
    int win_probe,
    int num_marked, int num_abandoned)
{
        if (net->RTO == 0) {
                if (net->RTO_measured) {
                        net->RTO = stcb->asoc.minrto;
                } else {
                        net->RTO = stcb->asoc.initial_rto;
                }
        }
        net->RTO <<= 1;
        if (net->RTO > stcb->asoc.maxrto) {
                net->RTO = stcb->asoc.maxrto;
        }
        if ((win_probe == 0) && (num_marked || num_abandoned)) {
                /* We don't apply penalty to window probe scenarios */
                /* JRS - Use the congestion control given in the CC module */
                stcb->asoc.cc_functions.sctp_cwnd_update_after_timeout(stcb, net);
        }
}
 
#ifndef INVARIANTS
static void
sctp_recover_sent_list(struct sctp_tcb *stcb)
{
        struct sctp_tmit_chunk *chk, *nchk;
        struct sctp_association *asoc;
 
        asoc = &stcb->asoc;
        TAILQ_FOREACH_SAFE(chk, &asoc->sent_queue, sctp_next, nchk) {
                if (SCTP_TSN_GE(asoc->last_acked_seq, chk->rec.data.tsn)) {
                        SCTP_PRINTF("Found chk:%p tsn:%x <= last_acked_seq:%x\n",
                            (void *)chk, chk->rec.data.tsn, asoc->last_acked_seq);
                        if (chk->sent != SCTP_DATAGRAM_NR_ACKED) {
                                if (asoc->strmout[chk->rec.data.sid].chunks_on_queues > 0) {
                                        asoc->strmout[chk->rec.data.sid].chunks_on_queues--;
                                }
                        }
                        if ((asoc->strmout[chk->rec.data.sid].chunks_on_queues == 0) &&
                            (asoc->strmout[chk->rec.data.sid].state == SCTP_STREAM_RESET_PENDING) &&
                            TAILQ_EMPTY(&asoc->strmout[chk->rec.data.sid].outqueue)) {
                                asoc->trigger_reset = 1;
                        }
                        TAILQ_REMOVE(&asoc->sent_queue, chk, sctp_next);
                        if (PR_SCTP_ENABLED(chk->flags)) {
                                if (asoc->pr_sctp_cnt != 0)
                                        asoc->pr_sctp_cnt--;
                        }
                        if (chk->data) {
                                /* sa_ignore NO_NULL_CHK */
                                sctp_free_bufspace(stcb, asoc, chk, 1);
                                sctp_m_freem(chk->data);
                                chk->data = NULL;
                                if (asoc->prsctp_supported && PR_SCTP_BUF_ENABLED(chk->flags)) {
                                        asoc->sent_queue_cnt_removeable--;
                                }
                        }
                        asoc->sent_queue_cnt--;
                        sctp_free_a_chunk(stcb, chk, SCTP_SO_NOT_LOCKED);
                }
        }
        SCTP_PRINTF("after recover order is as follows\n");
        TAILQ_FOREACH(chk, &asoc->sent_queue, sctp_next) {
                SCTP_PRINTF("chk:%p TSN:%x\n", (void *)chk, chk->rec.data.tsn);
        }
}
#endif
 
static int
sctp_mark_all_for_resend(struct sctp_tcb *stcb,
    struct sctp_nets *net,
    struct sctp_nets *alt,
    int window_probe,
    int *num_marked,
    int *num_abandoned)
{
 
        /*
         * Mark all chunks (well not all) that were sent to *net for
         * retransmission. Move them to alt for there destination as well...
         * We only mark chunks that have been outstanding long enough to
         * have received feed-back.
         */
        struct sctp_tmit_chunk *chk, *nchk;
        struct sctp_nets *lnets;
        struct timeval now, min_wait, tv;
        int cur_rto;
        int cnt_abandoned;
        int audit_tf, num_mk, fir;
        unsigned int cnt_mk;
        uint32_t orig_flight, orig_tf;
        uint32_t tsnlast, tsnfirst;
        int recovery_cnt = 0;
 
        /* none in flight now */
        audit_tf = 0;
        fir = 0;
        /*
         * figure out how long a data chunk must be pending before we can
         * mark it ..
         */
        (void)SCTP_GETTIME_TIMEVAL(&now);
        /* get cur rto in micro-seconds */
        cur_rto = (net->lastsa >> SCTP_RTT_SHIFT) + net->lastsv;
        cur_rto *= 1000;
        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FR_LOGGING_ENABLE) {
                sctp_log_fr(cur_rto,
                    stcb->asoc.peers_rwnd,
                    window_probe,
                    SCTP_FR_T3_MARK_TIME);
                sctp_log_fr(net->flight_size, 0, 0, SCTP_FR_CWND_REPORT);
                sctp_log_fr(net->flight_size, net->cwnd, stcb->asoc.total_flight, SCTP_FR_CWND_REPORT);
        }
        tv.tv_sec = cur_rto / 1000000;
        tv.tv_usec = cur_rto % 1000000;
        min_wait = now;
        timevalsub(&min_wait, &tv);
        if (min_wait.tv_sec < 0 || min_wait.tv_usec < 0) {
                /*
                 * if we hit here, we don't have enough seconds on the clock
                 * to account for the RTO. We just let the lower seconds be
                 * the bounds and don't worry about it. This may mean we
                 * will mark a lot more than we should.
                 */
                min_wait.tv_sec = min_wait.tv_usec = 0;
        }
        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FR_LOGGING_ENABLE) {
                sctp_log_fr(cur_rto, (uint32_t)now.tv_sec, now.tv_usec, SCTP_FR_T3_MARK_TIME);
                sctp_log_fr(0, (uint32_t)min_wait.tv_sec, min_wait.tv_usec, SCTP_FR_T3_MARK_TIME);
        }
        /*
         * Our rwnd will be incorrect here since we are not adding back the
         * cnt * mbuf but we will fix that down below.
         */
        orig_flight = net->flight_size;
        orig_tf = stcb->asoc.total_flight;
 
        net->fast_retran_ip = 0;
        /* Now on to each chunk */
        cnt_abandoned = 0;
        num_mk = cnt_mk = 0;
        tsnfirst = tsnlast = 0;
#ifndef INVARIANTS
start_again:
#endif
        TAILQ_FOREACH_SAFE(chk, &stcb->asoc.sent_queue, sctp_next, nchk) {
                if (SCTP_TSN_GE(stcb->asoc.last_acked_seq, chk->rec.data.tsn)) {
                        /* Strange case our list got out of order? */
                        SCTP_PRINTF("Our list is out of order? last_acked:%x chk:%x\n",
                            (unsigned int)stcb->asoc.last_acked_seq, (unsigned int)chk->rec.data.tsn);
                        recovery_cnt++;
#ifdef INVARIANTS
                        panic("last acked >= chk on sent-Q");
#else
                        SCTP_PRINTF("Recover attempts a restart cnt:%d\n", recovery_cnt);
                        sctp_recover_sent_list(stcb);
                        if (recovery_cnt < 10) {
                                goto start_again;
                        } else {
                                SCTP_PRINTF("Recovery fails %d times??\n", recovery_cnt);
                        }
#endif
                }
                if ((chk->whoTo == net) && (chk->sent < SCTP_DATAGRAM_ACKED)) {
                        /*
                         * found one to mark: If it is less than
                         * DATAGRAM_ACKED it MUST not be a skipped or marked
                         * TSN but instead one that is either already set
                         * for retransmission OR one that needs
                         * retransmission.
                         */
 
                        /* validate its been outstanding long enough */
                        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FR_LOGGING_ENABLE) {
                                sctp_log_fr(chk->rec.data.tsn,
                                    (uint32_t)chk->sent_rcv_time.tv_sec,
                                    chk->sent_rcv_time.tv_usec,
                                    SCTP_FR_T3_MARK_TIME);
                        }
                        if ((chk->sent_rcv_time.tv_sec > min_wait.tv_sec) && (window_probe == 0)) {
                                /*
                                 * we have reached a chunk that was sent
                                 * some seconds past our min.. forget it we
                                 * will find no more to send.
                                 */
                                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FR_LOGGING_ENABLE) {
                                        sctp_log_fr(0,
                                            (uint32_t)chk->sent_rcv_time.tv_sec,
                                            chk->sent_rcv_time.tv_usec,
                                            SCTP_FR_T3_STOPPED);
                                }
                                continue;
                        } else if ((chk->sent_rcv_time.tv_sec == min_wait.tv_sec) &&
                            (window_probe == 0)) {
                                /*
                                 * we must look at the micro seconds to
                                 * know.
                                 */
                                if (chk->sent_rcv_time.tv_usec >= min_wait.tv_usec) {
                                        /*
                                         * ok it was sent after our boundary
                                         * time.
                                         */
                                        continue;
                                }
                        }
                        if (stcb->asoc.prsctp_supported && PR_SCTP_TTL_ENABLED(chk->flags)) {
                                /* Is it expired? */
                                if (timevalcmp(&now, &chk->rec.data.timetodrop, >)) {
                                        /* Yes so drop it */
                                        if (chk->data) {
                                                (void)sctp_release_pr_sctp_chunk(stcb,
                                                    chk,
                                                    1,
                                                    SCTP_SO_NOT_LOCKED);
                                                cnt_abandoned++;
                                        }
                                        continue;
                                }
                        }
                        if (stcb->asoc.prsctp_supported && PR_SCTP_RTX_ENABLED(chk->flags)) {
                                /* Has it been retransmitted tv_sec times? */
                                if (chk->snd_count > chk->rec.data.timetodrop.tv_sec) {
                                        if (chk->data) {
                                                (void)sctp_release_pr_sctp_chunk(stcb,
                                                    chk,
                                                    1,
                                                    SCTP_SO_NOT_LOCKED);
                                                cnt_abandoned++;
                                        }
                                        continue;
                                }
                        }
                        if (chk->sent < SCTP_DATAGRAM_RESEND) {
                                sctp_ucount_incr(stcb->asoc.sent_queue_retran_cnt);
                                num_mk++;
                                if (fir == 0) {
                                        fir = 1;
                                        tsnfirst = chk->rec.data.tsn;
                                }
                                tsnlast = chk->rec.data.tsn;
                                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FR_LOGGING_ENABLE) {
                                        sctp_log_fr(chk->rec.data.tsn, chk->snd_count,
                                            0, SCTP_FR_T3_MARKED);
                                }
 
                                if (chk->rec.data.chunk_was_revoked) {
                                        /* deflate the cwnd */
                                        chk->whoTo->cwnd -= chk->book_size;
                                        chk->rec.data.chunk_was_revoked = 0;
                                }
                                net->marked_retrans++;
                                stcb->asoc.marked_retrans++;
                                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FLIGHT_LOGGING_ENABLE) {
                                        sctp_misc_ints(SCTP_FLIGHT_LOG_DOWN_RSND_TO,
                                            chk->whoTo->flight_size,
                                            chk->book_size,
                                            (uint32_t)(uintptr_t)chk->whoTo,
                                            chk->rec.data.tsn);
                                }
                                sctp_flight_size_decrease(chk);
                                sctp_total_flight_decrease(stcb, chk);
                                stcb->asoc.peers_rwnd += chk->send_size;
                                stcb->asoc.peers_rwnd += SCTP_BASE_SYSCTL(sctp_peer_chunk_oh);
                        }
                        chk->sent = SCTP_DATAGRAM_RESEND;
                        chk->flags |= CHUNK_FLAGS_FRAGMENT_OK;
                        SCTP_STAT_INCR(sctps_markedretrans);
 
                        /* reset the TSN for striking and other FR stuff */
                        chk->rec.data.doing_fast_retransmit = 0;
                        /* Clear any time so NO RTT is being done */
 
                        if (chk->do_rtt) {
                                if (chk->whoTo->rto_needed == 0) {
                                        chk->whoTo->rto_needed = 1;
                                }
                        }
                        chk->do_rtt = 0;
                        if (alt != net) {
                                sctp_free_remote_addr(chk->whoTo);
                                chk->no_fr_allowed = 1;
                                chk->whoTo = alt;
                                atomic_add_int(&alt->ref_count, 1);
                        } else {
                                chk->no_fr_allowed = 0;
                                if (TAILQ_EMPTY(&stcb->asoc.send_queue)) {
                                        chk->rec.data.fast_retran_tsn = stcb->asoc.sending_seq;
                                } else {
                                        chk->rec.data.fast_retran_tsn = (TAILQ_FIRST(&stcb->asoc.send_queue))->rec.data.tsn;
                                }
                        }
                        /*
                         * CMT: Do not allow FRs on retransmitted TSNs.
                         */
                        if (stcb->asoc.sctp_cmt_on_off > 0) {
                                chk->no_fr_allowed = 1;
                        }
#ifdef THIS_SHOULD_NOT_BE_DONE
                } else if (chk->sent == SCTP_DATAGRAM_ACKED) {
                        /* remember highest acked one */
                        could_be_sent = chk;
#endif
                }
                if (chk->sent == SCTP_DATAGRAM_RESEND) {
                        cnt_mk++;
                }
        }
        if ((orig_flight - net->flight_size) != (orig_tf - stcb->asoc.total_flight)) {
                /* we did not subtract the same things? */
                audit_tf = 1;
        }
 
        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FR_LOGGING_ENABLE) {
                sctp_log_fr(tsnfirst, tsnlast, num_mk, SCTP_FR_T3_TIMEOUT);
        }
#ifdef SCTP_DEBUG
        if (num_mk) {
                SCTPDBG(SCTP_DEBUG_TIMER1, "LAST TSN marked was %x\n",
                    tsnlast);
                SCTPDBG(SCTP_DEBUG_TIMER1, "Num marked for retransmission was %d peer-rwd:%u\n",
                    num_mk,
                    stcb->asoc.peers_rwnd);
        }
#endif
        *num_marked = num_mk;
        *num_abandoned = cnt_abandoned;
        /*
         * Now check for a ECN Echo that may be stranded And include the
         * cnt_mk'd to have all resends in the control queue.
         */
        TAILQ_FOREACH(chk, &stcb->asoc.control_send_queue, sctp_next) {
                if (chk->sent == SCTP_DATAGRAM_RESEND) {
                        cnt_mk++;
                }
                if ((chk->whoTo == net) &&
                    (chk->rec.chunk_id.id == SCTP_ECN_ECHO)) {
                        sctp_free_remote_addr(chk->whoTo);
                        chk->whoTo = alt;
                        if (chk->sent != SCTP_DATAGRAM_RESEND) {
                                chk->sent = SCTP_DATAGRAM_RESEND;
                                chk->flags |= CHUNK_FLAGS_FRAGMENT_OK;
                                sctp_ucount_incr(stcb->asoc.sent_queue_retran_cnt);
                                cnt_mk++;
                        }
                        atomic_add_int(&alt->ref_count, 1);
                }
        }
#ifdef THIS_SHOULD_NOT_BE_DONE
        if ((stcb->asoc.sent_queue_retran_cnt == 0) && (could_be_sent)) {
                /* fix it so we retransmit the highest acked anyway */
                sctp_ucount_incr(stcb->asoc.sent_queue_retran_cnt);
                cnt_mk++;
                could_be_sent->sent = SCTP_DATAGRAM_RESEND;
        }
#endif
        if (stcb->asoc.sent_queue_retran_cnt != cnt_mk) {
#ifdef INVARIANTS
                SCTP_PRINTF("Local Audit says there are %d for retran asoc cnt:%d we marked:%d this time\n",
                    cnt_mk, stcb->asoc.sent_queue_retran_cnt, num_mk);
#endif
#ifndef SCTP_AUDITING_ENABLED
                stcb->asoc.sent_queue_retran_cnt = cnt_mk;
#endif
        }
        if (audit_tf) {
                SCTPDBG(SCTP_DEBUG_TIMER4,
                    "Audit total flight due to negative value net:%p\n",
                    (void *)net);
                stcb->asoc.total_flight = 0;
                stcb->asoc.total_flight_count = 0;
                /* Clear all networks flight size */
                TAILQ_FOREACH(lnets, &stcb->asoc.nets, sctp_next) {
                        lnets->flight_size = 0;
                        SCTPDBG(SCTP_DEBUG_TIMER4,
                            "Net:%p c-f cwnd:%d ssthresh:%d\n",
                            (void *)lnets, lnets->cwnd, lnets->ssthresh);
                }
                TAILQ_FOREACH(chk, &stcb->asoc.sent_queue, sctp_next) {
                        if (chk->sent < SCTP_DATAGRAM_RESEND) {
                                if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FLIGHT_LOGGING_ENABLE) {
                                        sctp_misc_ints(SCTP_FLIGHT_LOG_UP,
                                            chk->whoTo->flight_size,
                                            chk->book_size,
                                            (uint32_t)(uintptr_t)chk->whoTo,
                                            chk->rec.data.tsn);
                                }
 
                                sctp_flight_size_increase(chk);
                                sctp_total_flight_increase(stcb, chk);
                        }
                }
        }
        /* We return 1 if we only have a window probe outstanding */
        return (0);
}
 
int
sctp_t3rxt_timer(struct sctp_inpcb *inp,
    struct sctp_tcb *stcb,
    struct sctp_nets *net)
{
        struct sctp_nets *alt;
        int win_probe, num_mk, num_abandoned;
 
        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_FR_LOGGING_ENABLE) {
                sctp_log_fr(0, 0, 0, SCTP_FR_T3_TIMEOUT);
        }
        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_LOGGING_ENABLE) {
                struct sctp_nets *lnet;
 
                TAILQ_FOREACH(lnet, &stcb->asoc.nets, sctp_next) {
                        if (net == lnet) {
                                sctp_log_cwnd(stcb, lnet, 1, SCTP_CWND_LOG_FROM_T3);
                        } else {
                                sctp_log_cwnd(stcb, lnet, 0, SCTP_CWND_LOG_FROM_T3);
                        }
                }
        }
        /* Find an alternate and mark those for retransmission */
        if ((stcb->asoc.peers_rwnd == 0) &&
            (stcb->asoc.total_flight < net->mtu)) {
                SCTP_STAT_INCR(sctps_timowindowprobe);
                win_probe = 1;
        } else {
                win_probe = 0;
        }
 
        if (win_probe == 0) {
                /* We don't do normal threshold management on window probes */
                if (sctp_threshold_management(inp, stcb, net,
                    stcb->asoc.max_send_times)) {
                        /* Association was destroyed */
                        return (1);
                } else {
                        if (net != stcb->asoc.primary_destination) {
                                /* send a immediate HB if our RTO is stale */
                                struct timeval now;
                                uint32_t ms_goneby;
 
                                (void)SCTP_GETTIME_TIMEVAL(&now);
                                if (net->last_sent_time.tv_sec) {
                                        ms_goneby = (uint32_t)(now.tv_sec - net->last_sent_time.tv_sec) * 1000;
                                } else {
                                        ms_goneby = 0;
                                }
                                if ((net->dest_state & SCTP_ADDR_PF) == 0) {
                                        if ((ms_goneby > net->RTO) || (net->RTO == 0)) {
                                                /*
                                                 * no recent feed back in an
                                                 * RTO or more, request a
                                                 * RTT update
                                                 */
                                                sctp_send_hb(stcb, net, SCTP_SO_NOT_LOCKED);
                                        }
                                }
                        }
                }
        } else {
                /*
                 * For a window probe we don't penalize the net's but only
                 * the association. This may fail it if SACKs are not coming
                 * back. If sack's are coming with rwnd locked at 0, we will
                 * continue to hold things waiting for rwnd to raise
                 */
                if (sctp_threshold_management(inp, stcb, NULL,
                    stcb->asoc.max_send_times)) {
                        /* Association was destroyed */
                        return (1);
                }
        }
        if (stcb->asoc.sctp_cmt_on_off > 0) {
                if (net->pf_threshold < net->failure_threshold) {
                        alt = sctp_find_alternate_net(stcb, net, 2);
                } else {
                        /*
                         * CMT: Using RTX_SSTHRESH policy for CMT. If CMT is
                         * being used, then pick dest with largest ssthresh
                         * for any retransmission.
                         */
                        alt = sctp_find_alternate_net(stcb, net, 1);
                        /*
                         * CUCv2: If a different dest is picked for the
                         * retransmission, then new (rtx-)pseudo_cumack
                         * needs to be tracked for orig dest. Let CUCv2
                         * track new (rtx-) pseudo-cumack always.
                         */
                        net->find_pseudo_cumack = 1;
                        net->find_rtx_pseudo_cumack = 1;
                }
        } else {
                alt = sctp_find_alternate_net(stcb, net, 0);
        }
 
        num_mk = 0;
        num_abandoned = 0;
        (void)sctp_mark_all_for_resend(stcb, net, alt, win_probe,
            &num_mk, &num_abandoned);
        /* FR Loss recovery just ended with the T3. */
        stcb->asoc.fast_retran_loss_recovery = 0;
 
        /* CMT FR loss recovery ended with the T3 */
        net->fast_retran_loss_recovery = 0;
        if ((stcb->asoc.cc_functions.sctp_cwnd_new_transmission_begins) &&
            (net->flight_size == 0)) {
                (*stcb->asoc.cc_functions.sctp_cwnd_new_transmission_begins) (stcb, net);
        }
 
        /*
         * setup the sat loss recovery that prevents satellite cwnd advance.
         */
        stcb->asoc.sat_t3_loss_recovery = 1;
        stcb->asoc.sat_t3_recovery_tsn = stcb->asoc.sending_seq;
 
        /* Backoff the timer and cwnd */
        sctp_backoff_on_timeout(stcb, net, win_probe, num_mk, num_abandoned);
        if ((!(net->dest_state & SCTP_ADDR_REACHABLE)) ||
            (net->dest_state & SCTP_ADDR_PF)) {
                /* Move all pending over too */
                sctp_move_chunks_from_net(stcb, net);
 
                /*
                 * Get the address that failed, to force a new src address
                 * selecton and a route allocation.
                 */
                if (net->ro._s_addr) {
                        sctp_free_ifa(net->ro._s_addr);
                        net->ro._s_addr = NULL;
                }
                net->src_addr_selected = 0;
 
                /* Force a route allocation too */
                RO_NHFREE(&net->ro);
 
                /* Was it our primary? */
                if ((stcb->asoc.primary_destination == net) && (alt != net)) {
                        /*
                         * Yes, note it as such and find an alternate note:
                         * this means HB code must use this to resent the
                         * primary if it goes active AND if someone does a
                         * change-primary then this flag must be cleared
                         * from any net structures.
                         */
                        if (stcb->asoc.alternate) {
                                sctp_free_remote_addr(stcb->asoc.alternate);
                        }
                        stcb->asoc.alternate = alt;
                        atomic_add_int(&stcb->asoc.alternate->ref_count, 1);
                }
        }
        /*
         * Special case for cookie-echo'ed case, we don't do output but must
         * await the COOKIE-ACK before retransmission
         */
        if (SCTP_GET_STATE(stcb) == SCTP_STATE_COOKIE_ECHOED) {
                /*
                 * Here we just reset the timer and start again since we
                 * have not established the asoc
                 */
                sctp_timer_start(SCTP_TIMER_TYPE_SEND, inp, stcb, net);
                return (0);
        }
        if (stcb->asoc.prsctp_supported) {
                struct sctp_tmit_chunk *lchk;
 
                lchk = sctp_try_advance_peer_ack_point(stcb, &stcb->asoc);
                /* C3. See if we need to send a Fwd-TSN */
                if (SCTP_TSN_GT(stcb->asoc.advanced_peer_ack_point, stcb->asoc.last_acked_seq)) {
                        send_forward_tsn(stcb, &stcb->asoc);
                        for (; lchk != NULL; lchk = TAILQ_NEXT(lchk, sctp_next)) {
                                if (lchk->whoTo != NULL) {
                                        break;
                                }
                        }
                        if (lchk != NULL) {
                                /* Assure a timer is up */
                                sctp_timer_start(SCTP_TIMER_TYPE_SEND, stcb->sctp_ep, stcb, lchk->whoTo);
                        }
                }
        }
        if (SCTP_BASE_SYSCTL(sctp_logging_level) & SCTP_CWND_MONITOR_ENABLE) {
                sctp_log_cwnd(stcb, net, net->cwnd, SCTP_CWND_LOG_FROM_RTX);
        }
        return (0);
}
 
int
sctp_t1init_timer(struct sctp_inpcb *inp,
    struct sctp_tcb *stcb,
    struct sctp_nets *net)
{
        /* bump the thresholds */
        if (stcb->asoc.delayed_connection) {
                /*
                 * special hook for delayed connection. The library did NOT
                 * complete the rest of its sends.
                 */
                stcb->asoc.delayed_connection = 0;
                sctp_send_initiate(inp, stcb, SCTP_SO_NOT_LOCKED);
                return (0);
        }
        if (SCTP_GET_STATE(stcb) != SCTP_STATE_COOKIE_WAIT) {
                return (0);
        }
        if (sctp_threshold_management(inp, stcb, net,
            stcb->asoc.max_init_times)) {
                /* Association was destroyed */
                return (1);
        }
        stcb->asoc.dropped_special_cnt = 0;
        sctp_backoff_on_timeout(stcb, stcb->asoc.primary_destination, 1, 0, 0);
        if (stcb->asoc.initial_init_rto_max < net->RTO) {
                net->RTO = stcb->asoc.initial_init_rto_max;
        }
        if (stcb->asoc.numnets > 1) {
                /* If we have more than one addr use it */
                struct sctp_nets *alt;
 
                alt = sctp_find_alternate_net(stcb, stcb->asoc.primary_destination, 0);
                if (alt != stcb->asoc.primary_destination) {
                        sctp_move_chunks_from_net(stcb, stcb->asoc.primary_destination);
                        stcb->asoc.primary_destination = alt;
                }
        }
        /* Send out a new init */
        sctp_send_initiate(inp, stcb, SCTP_SO_NOT_LOCKED);
        return (0);
}
 
/*
 * For cookie and asconf we actually need to find and mark for resend, then
 * increment the resend counter (after all the threshold management stuff of
 * course).
 */
int
sctp_cookie_timer(struct sctp_inpcb *inp,
    struct sctp_tcb *stcb,
    struct sctp_nets *net SCTP_UNUSED)
{
        struct sctp_nets *alt;
        struct sctp_tmit_chunk *cookie;
 
        /* first before all else we must find the cookie */
        TAILQ_FOREACH(cookie, &stcb->asoc.control_send_queue, sctp_next) {
                if (cookie->rec.chunk_id.id == SCTP_COOKIE_ECHO) {
                        break;
                }
        }
        if (cookie == NULL) {
                if (SCTP_GET_STATE(stcb) == SCTP_STATE_COOKIE_ECHOED) {
                        /* FOOBAR! */
                        struct mbuf *op_err;
 
                        op_err = sctp_generate_cause(SCTP_BASE_SYSCTL(sctp_diag_info_code),
                            "Cookie timer expired, but no cookie");
                        inp->last_abort_code = SCTP_FROM_SCTP_TIMER + SCTP_LOC_3;
                        sctp_abort_an_association(inp, stcb, op_err, false, SCTP_SO_NOT_LOCKED);
                } else {
#ifdef INVARIANTS
                        panic("Cookie timer expires in wrong state?");
#else
                        SCTP_PRINTF("Strange in state %d not cookie-echoed yet c-e timer expires?\n", SCTP_GET_STATE(stcb));
                        return (0);
#endif
                }
                return (0);
        }
        /* Ok we found the cookie, threshold management next */
        if (sctp_threshold_management(inp, stcb, cookie->whoTo,
            stcb->asoc.max_init_times)) {
                /* Assoc is over */
                return (1);
        }
        /*
         * Cleared threshold management, now lets backoff the address and
         * select an alternate
         */
        stcb->asoc.dropped_special_cnt = 0;
        sctp_backoff_on_timeout(stcb, cookie->whoTo, 1, 0, 0);
        alt = sctp_find_alternate_net(stcb, cookie->whoTo, 0);
        if (alt != cookie->whoTo) {
                sctp_free_remote_addr(cookie->whoTo);
                cookie->whoTo = alt;
                atomic_add_int(&alt->ref_count, 1);
        }
        /* Now mark the retran info */
        if (cookie->sent != SCTP_DATAGRAM_RESEND) {
                sctp_ucount_incr(stcb->asoc.sent_queue_retran_cnt);
        }
        cookie->sent = SCTP_DATAGRAM_RESEND;
        cookie->flags |= CHUNK_FLAGS_FRAGMENT_OK;
        /*
         * Now call the output routine to kick out the cookie again, Note we
         * don't mark any chunks for retran so that FR will need to kick in
         * to move these (or a send timer).
         */
        return (0);
}
 
int
sctp_strreset_timer(struct sctp_inpcb *inp, struct sctp_tcb *stcb)
{
        struct sctp_nets *alt, *net;
        struct sctp_tmit_chunk *strrst = NULL, *chk = NULL;
 
        if (stcb->asoc.stream_reset_outstanding == 0) {
                return (0);
        }
        /* find the existing STRRESET, we use the seq number we sent out on */
        (void)sctp_find_stream_reset(stcb, stcb->asoc.str_reset_seq_out, &strrst);
        if (strrst == NULL) {
                return (0);
        }
        net = strrst->whoTo;
        /* do threshold management */
        if (sctp_threshold_management(inp, stcb, net, stcb->asoc.max_send_times)) {
                /* Assoc is over */
                return (1);
        }
        /*
         * Cleared threshold management, now lets backoff the address and
         * select an alternate
         */
        sctp_backoff_on_timeout(stcb, net, 1, 0, 0);
        alt = sctp_find_alternate_net(stcb, net, 0);
        strrst->whoTo = alt;
        atomic_add_int(&alt->ref_count, 1);
 
        /* See if a ECN Echo is also stranded */
        TAILQ_FOREACH(chk, &stcb->asoc.control_send_queue, sctp_next) {
                if ((chk->whoTo == net) &&
                    (chk->rec.chunk_id.id == SCTP_ECN_ECHO)) {
                        sctp_free_remote_addr(chk->whoTo);
                        if (chk->sent != SCTP_DATAGRAM_RESEND) {
                                chk->sent = SCTP_DATAGRAM_RESEND;
                                chk->flags |= CHUNK_FLAGS_FRAGMENT_OK;
                                sctp_ucount_incr(stcb->asoc.sent_queue_retran_cnt);
                        }
                        chk->whoTo = alt;
                        atomic_add_int(&alt->ref_count, 1);
                }
        }
        if (!(net->dest_state & SCTP_ADDR_REACHABLE)) {
                /*
                 * If the address went un-reachable, we need to move to
                 * alternates for ALL chk's in queue
                 */
                sctp_move_chunks_from_net(stcb, net);
        }
        sctp_free_remote_addr(net);
 
        /* mark the retran info */
        if (strrst->sent != SCTP_DATAGRAM_RESEND)
                sctp_ucount_incr(stcb->asoc.sent_queue_retran_cnt);
        strrst->sent = SCTP_DATAGRAM_RESEND;
        strrst->flags |= CHUNK_FLAGS_FRAGMENT_OK;
 
        /* restart the timer */
        sctp_timer_start(SCTP_TIMER_TYPE_STRRESET, inp, stcb, alt);
        return (0);
}
 
int
sctp_asconf_timer(struct sctp_inpcb *inp, struct sctp_tcb *stcb,
    struct sctp_nets *net)
{
        struct sctp_nets *alt;
        struct sctp_tmit_chunk *asconf, *chk;
 
        /* is this a first send, or a retransmission? */
        if (TAILQ_EMPTY(&stcb->asoc.asconf_send_queue)) {
                /* compose a new ASCONF chunk and send it */
                sctp_send_asconf(stcb, net, SCTP_ADDR_NOT_LOCKED);
        } else {
                /*
                 * Retransmission of the existing ASCONF is needed
                 */
 
                /* find the existing ASCONF */
                asconf = TAILQ_FIRST(&stcb->asoc.asconf_send_queue);
                if (asconf == NULL) {
                        return (0);
                }
                net = asconf->whoTo;
                /* do threshold management */
                if (sctp_threshold_management(inp, stcb, net,
                    stcb->asoc.max_send_times)) {
                        /* Assoc is over */
                        return (1);
                }
                if (asconf->snd_count > stcb->asoc.max_send_times) {
                        /*
                         * Something is rotten: our peer is not responding
                         * to ASCONFs but apparently is to other chunks.
                         * i.e. it is not properly handling the chunk type
                         * upper bits. Mark this peer as ASCONF incapable
                         * and cleanup.
                         */
                        SCTPDBG(SCTP_DEBUG_TIMER1, "asconf_timer: Peer has not responded to our repeated ASCONFs\n");
                        sctp_asconf_cleanup(stcb);
                        return (0);
                }
                /*
                 * cleared threshold management, so now backoff the net and
                 * select an alternate
                 */
                sctp_backoff_on_timeout(stcb, net, 1, 0, 0);
                alt = sctp_find_alternate_net(stcb, net, 0);
                if (asconf->whoTo != alt) {
                        asconf->whoTo = alt;
                        atomic_add_int(&alt->ref_count, 1);
                }
 
                /* See if an ECN Echo is also stranded */
                TAILQ_FOREACH(chk, &stcb->asoc.control_send_queue, sctp_next) {
                        if ((chk->whoTo == net) &&
                            (chk->rec.chunk_id.id == SCTP_ECN_ECHO)) {
                                sctp_free_remote_addr(chk->whoTo);
                                chk->whoTo = alt;
                                if (chk->sent != SCTP_DATAGRAM_RESEND) {
                                        chk->sent = SCTP_DATAGRAM_RESEND;
                                        chk->flags |= CHUNK_FLAGS_FRAGMENT_OK;
                                        sctp_ucount_incr(stcb->asoc.sent_queue_retran_cnt);
                                }
                                atomic_add_int(&alt->ref_count, 1);
                        }
                }
                TAILQ_FOREACH(chk, &stcb->asoc.asconf_send_queue, sctp_next) {
                        if (chk->whoTo != alt) {
                                sctp_free_remote_addr(chk->whoTo);
                                chk->whoTo = alt;
                                atomic_add_int(&alt->ref_count, 1);
                        }
                        if (asconf->sent != SCTP_DATAGRAM_RESEND && chk->sent != SCTP_DATAGRAM_UNSENT)
                                sctp_ucount_incr(stcb->asoc.sent_queue_retran_cnt);
                        chk->sent = SCTP_DATAGRAM_RESEND;
                        chk->flags |= CHUNK_FLAGS_FRAGMENT_OK;
                }
                if (!(net->dest_state & SCTP_ADDR_REACHABLE)) {
                        /*
                         * If the address went un-reachable, we need to move
                         * to the alternate for ALL chunks in queue
                         */
                        sctp_move_chunks_from_net(stcb, net);
                }
                sctp_free_remote_addr(net);
 
                /* mark the retran info */
                if (asconf->sent != SCTP_DATAGRAM_RESEND)
                        sctp_ucount_incr(stcb->asoc.sent_queue_retran_cnt);
                asconf->sent = SCTP_DATAGRAM_RESEND;
                asconf->flags |= CHUNK_FLAGS_FRAGMENT_OK;
 
                /* send another ASCONF if any and we can do */
                sctp_send_asconf(stcb, alt, SCTP_ADDR_NOT_LOCKED);
        }
        return (0);
}
 
/* Mobility adaptation */
void
sctp_delete_prim_timer(struct sctp_inpcb *inp, struct sctp_tcb *stcb)
{
        if (stcb->asoc.deleted_primary == NULL) {
                SCTPDBG(SCTP_DEBUG_ASCONF1, "delete_prim_timer: deleted_primary is not stored...\n");
                sctp_mobility_feature_off(inp, SCTP_MOBILITY_PRIM_DELETED);
                return;
        }
        SCTPDBG(SCTP_DEBUG_ASCONF1, "delete_prim_timer: finished to keep deleted primary ");
        SCTPDBG_ADDR(SCTP_DEBUG_ASCONF1, &stcb->asoc.deleted_primary->ro._l_addr.sa);
        sctp_free_remote_addr(stcb->asoc.deleted_primary);
        stcb->asoc.deleted_primary = NULL;
        sctp_mobility_feature_off(inp, SCTP_MOBILITY_PRIM_DELETED);
        return;
}
 
/*
 * For the shutdown and shutdown-ack, we do not keep one around on the
 * control queue. This means we must generate a new one and call the general
 * chunk output routine, AFTER having done threshold management.
 * It is assumed that net is non-NULL.
 */
int
sctp_shutdown_timer(struct sctp_inpcb *inp, struct sctp_tcb *stcb,
    struct sctp_nets *net)
{
        struct sctp_nets *alt;
 
        /* first threshold management */
        if (sctp_threshold_management(inp, stcb, net, stcb->asoc.max_send_times)) {
                /* Assoc is over */
                return (1);
        }
        sctp_backoff_on_timeout(stcb, net, 1, 0, 0);
        /* second select an alternative */
        alt = sctp_find_alternate_net(stcb, net, 0);
 
        /* third generate a shutdown into the queue for out net */
        sctp_send_shutdown(stcb, alt);
 
        /* fourth restart timer */
        sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWN, inp, stcb, alt);
        return (0);
}
 
int
sctp_shutdownack_timer(struct sctp_inpcb *inp, struct sctp_tcb *stcb,
    struct sctp_nets *net)
{
        struct sctp_nets *alt;
 
        /* first threshold management */
        if (sctp_threshold_management(inp, stcb, net, stcb->asoc.max_send_times)) {
                /* Assoc is over */
                return (1);
        }
        sctp_backoff_on_timeout(stcb, net, 1, 0, 0);
        /* second select an alternative */
        alt = sctp_find_alternate_net(stcb, net, 0);
 
        /* third generate a shutdown into the queue for out net */
        sctp_send_shutdown_ack(stcb, alt);
 
        /* fourth restart timer */
        sctp_timer_start(SCTP_TIMER_TYPE_SHUTDOWNACK, inp, stcb, alt);
        return (0);
}
 
static void
sctp_audit_stream_queues_for_size(struct sctp_inpcb *inp, struct sctp_tcb *stcb)
{
        struct sctp_stream_queue_pending *sp;
        unsigned int i, chks_in_queue = 0;
        int being_filled = 0;
 
        KASSERT(inp != NULL, ("inp is NULL"));
        KASSERT(stcb != NULL, ("stcb is NULL"));
 
        SCTP_TCB_SEND_LOCK(stcb);
        KASSERT(TAILQ_EMPTY(&stcb->asoc.send_queue), ("send_queue not empty"));
        KASSERT(TAILQ_EMPTY(&stcb->asoc.sent_queue), ("sent_queue not empty"));
 
        if (stcb->asoc.sent_queue_retran_cnt) {
                SCTP_PRINTF("Hmm, sent_queue_retran_cnt is non-zero %d\n",
                    stcb->asoc.sent_queue_retran_cnt);
                stcb->asoc.sent_queue_retran_cnt = 0;
        }
        if (stcb->asoc.ss_functions.sctp_ss_is_empty(stcb, &stcb->asoc)) {
                /* No stream scheduler information, initialize scheduler */
                stcb->asoc.ss_functions.sctp_ss_init(stcb, &stcb->asoc);
                if (!stcb->asoc.ss_functions.sctp_ss_is_empty(stcb, &stcb->asoc)) {
                        /* yep, we lost a stream or two */
                        SCTP_PRINTF("Found additional streams NOT managed by scheduler, corrected\n");
                } else {
                        /* no streams lost */
                        stcb->asoc.total_output_queue_size = 0;
                }
        }
        /* Check to see if some data queued, if so report it */
        for (i = 0; i < stcb->asoc.streamoutcnt; i++) {
                if (!TAILQ_EMPTY(&stcb->asoc.strmout[i].outqueue)) {
                        TAILQ_FOREACH(sp, &stcb->asoc.strmout[i].outqueue, next) {
                                if (sp->msg_is_complete)
                                        being_filled++;
                                chks_in_queue++;
                        }
                }
        }
        if (chks_in_queue != stcb->asoc.stream_queue_cnt) {
                SCTP_PRINTF("Hmm, stream queue cnt at %d I counted %d in stream out wheel\n",
                    stcb->asoc.stream_queue_cnt, chks_in_queue);
        }
        SCTP_TCB_SEND_UNLOCK(stcb);
        if (chks_in_queue) {
                /* call the output queue function */
                sctp_chunk_output(inp, stcb, SCTP_OUTPUT_FROM_T3, SCTP_SO_NOT_LOCKED);
                if ((TAILQ_EMPTY(&stcb->asoc.send_queue)) &&
                    (TAILQ_EMPTY(&stcb->asoc.sent_queue))) {
                        /*
                         * Probably should go in and make it go back through
                         * and add fragments allowed
                         */
                        if (being_filled == 0) {
                                SCTP_PRINTF("Still nothing moved %d chunks are stuck\n",
                                    chks_in_queue);
                        }
                }
        } else {
                SCTP_PRINTF("Found no chunks on any queue tot:%lu\n",
                    (u_long)stcb->asoc.total_output_queue_size);
                stcb->asoc.total_output_queue_size = 0;
        }
}
 
int
sctp_heartbeat_timer(struct sctp_inpcb *inp, struct sctp_tcb *stcb,
    struct sctp_nets *net)
{
        uint8_t net_was_pf;
 
        if (net->dest_state & SCTP_ADDR_PF) {
                net_was_pf = 1;
        } else {
                net_was_pf = 0;
        }
        if (net->hb_responded == 0) {
                if (net->ro._s_addr) {
                        /*
                         * Invalidate the src address if we did not get a
                         * response last time.
                         */
                        sctp_free_ifa(net->ro._s_addr);
                        net->ro._s_addr = NULL;
                        net->src_addr_selected = 0;
                }
                sctp_backoff_on_timeout(stcb, net, 1, 0, 0);
                if (sctp_threshold_management(inp, stcb, net, stcb->asoc.max_send_times)) {
                        /* Assoc is over */
                        return (1);
                }
        }
        /* Zero PBA, if it needs it */
        if (net->partial_bytes_acked) {
                net->partial_bytes_acked = 0;
        }
        if ((stcb->asoc.total_output_queue_size > 0) &&
            (TAILQ_EMPTY(&stcb->asoc.send_queue)) &&
            (TAILQ_EMPTY(&stcb->asoc.sent_queue))) {
                sctp_audit_stream_queues_for_size(inp, stcb);
        }
        if (!(net->dest_state & SCTP_ADDR_NOHB) &&
            !((net_was_pf == 0) && (net->dest_state & SCTP_ADDR_PF))) {
                /*
                 * when move to PF during threshold mangement, a HB has been
                 * queued in that routine
                 */
                uint32_t ms_gone_by;
 
                if ((net->last_sent_time.tv_sec > 0) ||
                    (net->last_sent_time.tv_usec > 0)) {
                        struct timeval diff;
 
                        SCTP_GETTIME_TIMEVAL(&diff);
                        timevalsub(&diff, &net->last_sent_time);
                        ms_gone_by = (uint32_t)(diff.tv_sec * 1000) +
                            (uint32_t)(diff.tv_usec / 1000);
                } else {
                        ms_gone_by = 0xffffffff;
                }
                if ((ms_gone_by >= net->heart_beat_delay) ||
                    (net->dest_state & SCTP_ADDR_PF)) {
                        sctp_send_hb(stcb, net, SCTP_SO_NOT_LOCKED);
                }
        }
        return (0);
}
 
void
sctp_pathmtu_timer(struct sctp_inpcb *inp,
    struct sctp_tcb *stcb,
    struct sctp_nets *net)
{
        uint32_t next_mtu, mtu;
 
        next_mtu = sctp_get_next_mtu(net->mtu);
 
        if ((next_mtu > net->mtu) && (net->port == 0)) {
                if ((net->src_addr_selected == 0) ||
                    (net->ro._s_addr == NULL) ||
                    (net->ro._s_addr->localifa_flags & SCTP_BEING_DELETED)) {
                        if ((net->ro._s_addr != NULL) && (net->ro._s_addr->localifa_flags & SCTP_BEING_DELETED)) {
                                sctp_free_ifa(net->ro._s_addr);
                                net->ro._s_addr = NULL;
                                net->src_addr_selected = 0;
                        } else if (net->ro._s_addr == NULL) {
#if defined(INET6) && defined(SCTP_EMBEDDED_V6_SCOPE)
                                if (net->ro._l_addr.sa.sa_family == AF_INET6) {
                                        struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&net->ro._l_addr;
 
                                        /* KAME hack: embed scopeid */
                                        (void)sa6_embedscope(sin6, MODULE_GLOBAL(ip6_use_defzone));
                                }
#endif
 
                                net->ro._s_addr = sctp_source_address_selection(inp,
                                    stcb,
                                    (sctp_route_t *)&net->ro,
                                    net, 0, stcb->asoc.vrf_id);
#if defined(INET6) && defined(SCTP_EMBEDDED_V6_SCOPE)
                                if (net->ro._l_addr.sa.sa_family == AF_INET6) {
                                        struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&net->ro._l_addr;
 
                                        (void)sa6_recoverscope(sin6);
                                }
#endif                          /* INET6 */
                        }
                        if (net->ro._s_addr)
                                net->src_addr_selected = 1;
                }
                if (net->ro._s_addr) {
                        mtu = SCTP_GATHER_MTU_FROM_ROUTE(net->ro._s_addr, &net->ro._s_addr.sa, net->ro.ro_nh);
#if defined(INET) || defined(INET6)
                        if (net->port) {
                                mtu -= sizeof(struct udphdr);
                        }
#endif
                        if (mtu > next_mtu) {
                                net->mtu = next_mtu;
                        } else {
                                net->mtu = mtu;
                        }
                }
        }
        /* restart the timer */
        sctp_timer_start(SCTP_TIMER_TYPE_PATHMTURAISE, inp, stcb, net);
}
 
void
sctp_autoclose_timer(struct sctp_inpcb *inp, struct sctp_tcb *stcb)
{
        struct timeval tn, *tim_touse;
        struct sctp_association *asoc;
        uint32_t ticks_gone_by;
 
        (void)SCTP_GETTIME_TIMEVAL(&tn);
        if (stcb->asoc.sctp_autoclose_ticks > 0 &&
            sctp_is_feature_on(inp, SCTP_PCB_FLAGS_AUTOCLOSE)) {
                /* Auto close is on */
                asoc = &stcb->asoc;
                /* pick the time to use */
                if (asoc->time_last_rcvd.tv_sec >
                    asoc->time_last_sent.tv_sec) {
                        tim_touse = &asoc->time_last_rcvd;
                } else {
                        tim_touse = &asoc->time_last_sent;
                }
                /* Now has long enough transpired to autoclose? */
                ticks_gone_by = sctp_secs_to_ticks((uint32_t)(tn.tv_sec - tim_touse->tv_sec));
                if (ticks_gone_by >= asoc->sctp_autoclose_ticks) {
                        /*
                         * autoclose time has hit, call the output routine,
                         * which should do nothing just to be SURE we don't
                         * have hanging data. We can then safely check the
                         * queues and know that we are clear to send
                         * shutdown
                         */
                        sctp_chunk_output(inp, stcb, SCTP_OUTPUT_FROM_AUTOCLOSE_TMR, SCTP_SO_NOT_LOCKED);
                        /* Are we clean? */
                        if (TAILQ_EMPTY(&asoc->send_queue) &&
                            TAILQ_EMPTY(&asoc->sent_queue)) {
                                /*
                                 * there is nothing queued to send, so I'm
                                 * done...
                                 */
                                if (SCTP_GET_STATE(stcb) != SCTP_STATE_SHUTDOWN_SENT) {
                                        /* only send SHUTDOWN 1st time thru */
                                        struct sctp_nets *net;
 
                                        if ((SCTP_GET_STATE(stcb) == SCTP_STATE_OPEN) ||
                                            (SCTP_GET_STATE(stcb) == SCTP_STATE_SHUTDOWN_RECEIVED)) {
                                                SCTP_STAT_DECR_GAUGE32(sctps_currestab);
                                        }
                                        SCTP_SET_STATE(stcb, SCTP_STATE_SHUTDOWN_SENT);
                                        sctp_stop_timers_for_shutdown(stcb);
                                        if (stcb->asoc.alternate) {
                                                net = stcb->asoc.alternate;
                                        } else {
                                                net = stcb->asoc.primary_destination;
                                        }
                                        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);
                                }
                        }
                } else {
                        /*
                         * No auto close at this time, reset t-o to check
                         * later
                         */
                        uint32_t tmp;
 
                        /* fool the timer startup to use the time left */
                        tmp = asoc->sctp_autoclose_ticks;
                        asoc->sctp_autoclose_ticks -= ticks_gone_by;
                        sctp_timer_start(SCTP_TIMER_TYPE_AUTOCLOSE, inp, stcb, NULL);
                        /* restore the real tick value */
                        asoc->sctp_autoclose_ticks = tmp;
                }
        }
}