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sm_sideeffect.c

/* SCTP kernel reference Implementation
 * (C) Copyright IBM Corp. 2001, 2004
 * Copyright (c) 1999 Cisco, Inc.
 * Copyright (c) 1999-2001 Motorola, Inc.
 *
 * This file is part of the SCTP kernel reference Implementation
 *
 * These functions work with the state functions in sctp_sm_statefuns.c
 * to implement that state operations.  These functions implement the
 * steps which require modifying existing data structures.
 *
 * The SCTP reference implementation is free software;
 * you can redistribute it and/or modify it under the terms of
 * the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * The SCTP reference implementation is distributed in the hope that it
 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
 *                 ************************
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GNU CC; see the file COPYING.  If not, write to
 * the Free Software Foundation, 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * Please send any bug reports or fixes you make to the
 * email address(es):
 *    lksctp developers <lksctp-developers@lists.sourceforge.net>
 *
 * Or submit a bug report through the following website:
 *    http://www.sf.net/projects/lksctp
 *
 * Written or modified by:
 *    La Monte H.P. Yarroll <piggy@acm.org>
 *    Karl Knutson          <karl@athena.chicago.il.us>
 *    Jon Grimm             <jgrimm@austin.ibm.com>
 *    Hui Huang             <hui.huang@nokia.com>
 *    Dajiang Zhang         <dajiang.zhang@nokia.com>
 *    Daisy Chang     <daisyc@us.ibm.com>
 *    Sridhar Samudrala     <sri@us.ibm.com>
 *    Ardelle Fan     <ardelle.fan@intel.com>
 *
 * Any bugs reported given to us we will try to fix... any fixes shared will
 * be incorporated into the next SCTP release.
 */

#include <linux/skbuff.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/ip.h>
#include <net/sock.h>
#include <net/sctp/sctp.h>
#include <net/sctp/sm.h>

static int sctp_cmd_interpreter(sctp_event_t event_type,
                        sctp_subtype_t subtype,
                        sctp_state_t state,
                        struct sctp_endpoint *ep,
                        struct sctp_association *asoc,
                        void *event_arg,
                        sctp_disposition_t status,
                        sctp_cmd_seq_t *commands,
                        gfp_t gfp);
static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
                       sctp_state_t state,
                       struct sctp_endpoint *ep,
                       struct sctp_association *asoc,
                       void *event_arg,
                       sctp_disposition_t status,
                       sctp_cmd_seq_t *commands,
                       gfp_t gfp);

/********************************************************************
 * Helper functions
 ********************************************************************/

/* A helper function for delayed processing of INET ECN CE bit. */
static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
                        __u32 lowest_tsn)
{
      /* Save the TSN away for comparison when we receive CWR */

      asoc->last_ecne_tsn = lowest_tsn;
      asoc->need_ecne = 1;
}

/* Helper function for delayed processing of SCTP ECNE chunk.  */
/* RFC 2960 Appendix A
 *
 * RFC 2481 details a specific bit for a sender to send in
 * the header of its next outbound TCP segment to indicate to
 * its peer that it has reduced its congestion window.  This
 * is termed the CWR bit.  For SCTP the same indication is made
 * by including the CWR chunk.  This chunk contains one data
 * element, i.e. the TSN number that was sent in the ECNE chunk.
 * This element represents the lowest TSN number in the datagram
 * that was originally marked with the CE bit.
 */
static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
                                 __u32 lowest_tsn,
                                 struct sctp_chunk *chunk)
{
      struct sctp_chunk *repl;

      /* Our previously transmitted packet ran into some congestion
       * so we should take action by reducing cwnd and ssthresh
       * and then ACK our peer that we we've done so by
       * sending a CWR.
       */

      /* First, try to determine if we want to actually lower
       * our cwnd variables.  Only lower them if the ECNE looks more
       * recent than the last response.
       */
      if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
            struct sctp_transport *transport;

            /* Find which transport's congestion variables
             * need to be adjusted.
             */
            transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);

            /* Update the congestion variables. */
            if (transport)
                  sctp_transport_lower_cwnd(transport,
                                      SCTP_LOWER_CWND_ECNE);
            asoc->last_cwr_tsn = lowest_tsn;
      }

      /* Always try to quiet the other end.  In case of lost CWR,
       * resend last_cwr_tsn.
       */
      repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);

      /* If we run out of memory, it will look like a lost CWR.  We'll
       * get back in sync eventually.
       */
      return repl;
}

/* Helper function to do delayed processing of ECN CWR chunk.  */
static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
                         __u32 lowest_tsn)
{
      /* Turn off ECNE getting auto-prepended to every outgoing
       * packet
       */
      asoc->need_ecne = 0;
}

/* Generate SACK if necessary.  We call this at the end of a packet.  */
static int sctp_gen_sack(struct sctp_association *asoc, int force,
                   sctp_cmd_seq_t *commands)
{
      __u32 ctsn, max_tsn_seen;
      struct sctp_chunk *sack;
      struct sctp_transport *trans = asoc->peer.last_data_from;
      int error = 0;

      if (force ||
          (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
          (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
            asoc->peer.sack_needed = 1;

      ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
      max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);

      /* From 12.2 Parameters necessary per association (i.e. the TCB):
       *
       * Ack State : This flag indicates if the next received packet
       *         : is to be responded to with a SACK. ...
       *         : When DATA chunks are out of order, SACK's
       *           : are not delayed (see Section 6).
       *
       * [This is actually not mentioned in Section 6, but we
       * implement it here anyway. --piggy]
       */
      if (max_tsn_seen != ctsn)
            asoc->peer.sack_needed = 1;

      /* From 6.2  Acknowledgement on Reception of DATA Chunks:
       *
       * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
       * an acknowledgement SHOULD be generated for at least every
       * second packet (not every second DATA chunk) received, and
       * SHOULD be generated within 200 ms of the arrival of any
       * unacknowledged DATA chunk. ...
       */
      if (!asoc->peer.sack_needed) {
            /* We will need a SACK for the next packet.  */
            asoc->peer.sack_needed = 1;

            /* Set the SACK delay timeout based on the
             * SACK delay for the last transport
             * data was received from, or the default
             * for the association.
             */
            if (trans)
                  asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
                        trans->sackdelay;
            else
                  asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
                        asoc->sackdelay;

            /* Restart the SACK timer. */
            sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
                        SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
      } else {
            if (asoc->a_rwnd > asoc->rwnd)
                  asoc->a_rwnd = asoc->rwnd;
            sack = sctp_make_sack(asoc);
            if (!sack)
                  goto nomem;

            asoc->peer.sack_needed = 0;

            sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));

            /* Stop the SACK timer.  */
            sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
                        SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
      }

      return error;
nomem:
      error = -ENOMEM;
      return error;
}

/* When the T3-RTX timer expires, it calls this function to create the
 * relevant state machine event.
 */
void sctp_generate_t3_rtx_event(unsigned long peer)
{
      int error;
      struct sctp_transport *transport = (struct sctp_transport *) peer;
      struct sctp_association *asoc = transport->asoc;

      /* Check whether a task is in the sock.  */

      sctp_bh_lock_sock(asoc->base.sk);
      if (sock_owned_by_user(asoc->base.sk)) {
            SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __FUNCTION__);

            /* Try again later.  */
            if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
                  sctp_transport_hold(transport);
            goto out_unlock;
      }

      /* Is this transport really dead and just waiting around for
       * the timer to let go of the reference?
       */
      if (transport->dead)
            goto out_unlock;

      /* Run through the state machine.  */
      error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
                     SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
                     asoc->state,
                     asoc->ep, asoc,
                     transport, GFP_ATOMIC);

      if (error)
            asoc->base.sk->sk_err = -error;

out_unlock:
      sctp_bh_unlock_sock(asoc->base.sk);
      sctp_transport_put(transport);
}

/* This is a sa interface for producing timeout events.  It works
 * for timeouts which use the association as their parameter.
 */
static void sctp_generate_timeout_event(struct sctp_association *asoc,
                              sctp_event_timeout_t timeout_type)
{
      int error = 0;

      sctp_bh_lock_sock(asoc->base.sk);
      if (sock_owned_by_user(asoc->base.sk)) {
            SCTP_DEBUG_PRINTK("%s:Sock is busy: timer %d\n",
                          __FUNCTION__,
                          timeout_type);

            /* Try again later.  */
            if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
                  sctp_association_hold(asoc);
            goto out_unlock;
      }

      /* Is this association really dead and just waiting around for
       * the timer to let go of the reference?
       */
      if (asoc->base.dead)
            goto out_unlock;

      /* Run through the state machine.  */
      error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
                     SCTP_ST_TIMEOUT(timeout_type),
                     asoc->state, asoc->ep, asoc,
                     (void *)timeout_type, GFP_ATOMIC);

      if (error)
            asoc->base.sk->sk_err = -error;

out_unlock:
      sctp_bh_unlock_sock(asoc->base.sk);
      sctp_association_put(asoc);
}

static void sctp_generate_t1_cookie_event(unsigned long data)
{
      struct sctp_association *asoc = (struct sctp_association *) data;
      sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
}

static void sctp_generate_t1_init_event(unsigned long data)
{
      struct sctp_association *asoc = (struct sctp_association *) data;
      sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
}

static void sctp_generate_t2_shutdown_event(unsigned long data)
{
      struct sctp_association *asoc = (struct sctp_association *) data;
      sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
}

static void sctp_generate_t4_rto_event(unsigned long data)
{
      struct sctp_association *asoc = (struct sctp_association *) data;
      sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
}

static void sctp_generate_t5_shutdown_guard_event(unsigned long data)
{
      struct sctp_association *asoc = (struct sctp_association *)data;
      sctp_generate_timeout_event(asoc,
                            SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);

} /* sctp_generate_t5_shutdown_guard_event() */

static void sctp_generate_autoclose_event(unsigned long data)
{
      struct sctp_association *asoc = (struct sctp_association *) data;
      sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
}

/* Generate a heart beat event.  If the sock is busy, reschedule.   Make
 * sure that the transport is still valid.
 */
void sctp_generate_heartbeat_event(unsigned long data)
{
      int error = 0;
      struct sctp_transport *transport = (struct sctp_transport *) data;
      struct sctp_association *asoc = transport->asoc;

      sctp_bh_lock_sock(asoc->base.sk);
      if (sock_owned_by_user(asoc->base.sk)) {
            SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __FUNCTION__);

            /* Try again later.  */
            if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
                  sctp_transport_hold(transport);
            goto out_unlock;
      }

      /* Is this structure just waiting around for us to actually
       * get destroyed?
       */
      if (transport->dead)
            goto out_unlock;

      error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
                     SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
                     asoc->state, asoc->ep, asoc,
                     transport, GFP_ATOMIC);

       if (error)
             asoc->base.sk->sk_err = -error;

out_unlock:
      sctp_bh_unlock_sock(asoc->base.sk);
      sctp_transport_put(transport);
}

/* Inject a SACK Timeout event into the state machine.  */
static void sctp_generate_sack_event(unsigned long data)
{
      struct sctp_association *asoc = (struct sctp_association *) data;
      sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
}

sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
      NULL,
      sctp_generate_t1_cookie_event,
      sctp_generate_t1_init_event,
      sctp_generate_t2_shutdown_event,
      NULL,
      sctp_generate_t4_rto_event,
      sctp_generate_t5_shutdown_guard_event,
      NULL,
      sctp_generate_sack_event,
      sctp_generate_autoclose_event,
};


/* RFC 2960 8.2 Path Failure Detection
 *
 * When its peer endpoint is multi-homed, an endpoint should keep a
 * error counter for each of the destination transport addresses of the
 * peer endpoint.
 *
 * Each time the T3-rtx timer expires on any address, or when a
 * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
 * the error counter of that destination address will be incremented.
 * When the value in the error counter exceeds the protocol parameter
 * 'Path.Max.Retrans' of that destination address, the endpoint should
 * mark the destination transport address as inactive, and a
 * notification SHOULD be sent to the upper layer.
 *
 */
static void sctp_do_8_2_transport_strike(struct sctp_association *asoc,
                               struct sctp_transport *transport)
{
      /* The check for association's overall error counter exceeding the
       * threshold is done in the state function.
       */
      /* When probing UNCONFIRMED addresses, the association overall
       * error count is NOT incremented
       */
      if (transport->state != SCTP_UNCONFIRMED)
            asoc->overall_error_count++;

      if (transport->state != SCTP_INACTIVE &&
          (transport->error_count++ >= transport->pathmaxrxt)) {
            SCTP_DEBUG_PRINTK_IPADDR("transport_strike:association %p",
                               " transport IP: port:%d failed.\n",
                               asoc,
                               (&transport->ipaddr),
                               ntohs(transport->ipaddr.v4.sin_port));
            sctp_assoc_control_transport(asoc, transport,
                                   SCTP_TRANSPORT_DOWN,
                                   SCTP_FAILED_THRESHOLD);
      }

      /* E2) For the destination address for which the timer
       * expires, set RTO <- RTO * 2 ("back off the timer").  The
       * maximum value discussed in rule C7 above (RTO.max) may be
       * used to provide an upper bound to this doubling operation.
       */
      transport->last_rto = transport->rto;
      transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
}

/* Worker routine to handle INIT command failure.  */
static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
                         struct sctp_association *asoc,
                         unsigned error)
{
      struct sctp_ulpevent *event;

      event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC,
                                    (__u16)error, 0, 0, NULL,
                                    GFP_ATOMIC);

      if (event)
            sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
                        SCTP_ULPEVENT(event));

      sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
                  SCTP_STATE(SCTP_STATE_CLOSED));

      /* SEND_FAILED sent later when cleaning up the association. */
      asoc->outqueue.error = error;
      sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
}

/* Worker routine to handle SCTP_CMD_ASSOC_FAILED.  */
static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
                          struct sctp_association *asoc,
                          sctp_event_t event_type,
                          sctp_subtype_t subtype,
                          struct sctp_chunk *chunk,
                          unsigned error)
{
      struct sctp_ulpevent *event;

      /* Cancel any partial delivery in progress. */
      sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);

      if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
            event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
                                    (__u16)error, 0, 0, chunk,
                                    GFP_ATOMIC);
      else
            event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
                                    (__u16)error, 0, 0, NULL,
                                    GFP_ATOMIC);
      if (event)
            sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
                        SCTP_ULPEVENT(event));

      sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
                  SCTP_STATE(SCTP_STATE_CLOSED));

      /* SEND_FAILED sent later when cleaning up the association. */
      asoc->outqueue.error = error;
      sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
}

/* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
 * inside the cookie.  In reality, this is only used for INIT-ACK processing
 * since all other cases use "temporary" associations and can do all
 * their work in statefuns directly.
 */
static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
                         struct sctp_association *asoc,
                         struct sctp_chunk *chunk,
                         sctp_init_chunk_t *peer_init,
                         gfp_t gfp)
{
      int error;

      /* We only process the init as a sideeffect in a single
       * case.   This is when we process the INIT-ACK.   If we
       * fail during INIT processing (due to malloc problems),
       * just return the error and stop processing the stack.
       */
      if (!sctp_process_init(asoc, chunk->chunk_hdr->type,
                         sctp_source(chunk), peer_init, gfp))
            error = -ENOMEM;
      else
            error = 0;

      return error;
}

/* Helper function to break out starting up of heartbeat timers.  */
static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
                             struct sctp_association *asoc)
{
      struct sctp_transport *t;
      struct list_head *pos;

      /* Start a heartbeat timer for each transport on the association.
       * hold a reference on the transport to make sure none of
       * the needed data structures go away.
       */
      list_for_each(pos, &asoc->peer.transport_addr_list) {
            t = list_entry(pos, struct sctp_transport, transports);

            if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
                  sctp_transport_hold(t);
      }
}

static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
                            struct sctp_association *asoc)
{
      struct sctp_transport *t;
      struct list_head *pos;

      /* Stop all heartbeat timers. */

      list_for_each(pos, &asoc->peer.transport_addr_list) {
            t = list_entry(pos, struct sctp_transport, transports);
            if (del_timer(&t->hb_timer))
                  sctp_transport_put(t);
      }
}

/* Helper function to stop any pending T3-RTX timers */
static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
                              struct sctp_association *asoc)
{
      struct sctp_transport *t;
      struct list_head *pos;

      list_for_each(pos, &asoc->peer.transport_addr_list) {
            t = list_entry(pos, struct sctp_transport, transports);
            if (timer_pending(&t->T3_rtx_timer) &&
                del_timer(&t->T3_rtx_timer)) {
                  sctp_transport_put(t);
            }
      }
}


/* Helper function to update the heartbeat timer. */
static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
                             struct sctp_association *asoc,
                             struct sctp_transport *t)
{
      /* Update the heartbeat timer.  */
      if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
            sctp_transport_hold(t);
}

/* Helper function to handle the reception of an HEARTBEAT ACK.  */
static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
                          struct sctp_association *asoc,
                          struct sctp_transport *t,
                          struct sctp_chunk *chunk)
{
      sctp_sender_hb_info_t *hbinfo;

      /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
       * HEARTBEAT should clear the error counter of the destination
       * transport address to which the HEARTBEAT was sent.
       * The association's overall error count is also cleared.
       */
      t->error_count = 0;
      t->asoc->overall_error_count = 0;

      /* Mark the destination transport address as active if it is not so
       * marked.
       */
      if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED))
            sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
                                   SCTP_HEARTBEAT_SUCCESS);

      /* The receiver of the HEARTBEAT ACK should also perform an
       * RTT measurement for that destination transport address
       * using the time value carried in the HEARTBEAT ACK chunk.
       * If the transport's rto_pending variable has been cleared,
       * it was most likely due to a retransmit.  However, we want
       * to re-enable it to properly update the rto.
       */
      if (t->rto_pending == 0)
            t->rto_pending = 1;

      hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
      sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));

      /* Update the heartbeat timer.  */
      if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
            sctp_transport_hold(t);
}

/* Helper function to do a transport reset at the expiry of the hearbeat
 * timer.
 */
static void sctp_cmd_transport_reset(sctp_cmd_seq_t *cmds,
                             struct sctp_association *asoc,
                             struct sctp_transport *t)
{
      sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);

      /* Mark one strike against a transport.  */
      sctp_do_8_2_transport_strike(asoc, t);
}

/* Helper function to process the process SACK command.  */
static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
                         struct sctp_association *asoc,
                         struct sctp_sackhdr *sackh)
{
      int err;

      if (sctp_outq_sack(&asoc->outqueue, sackh)) {
            /* There are no more TSNs awaiting SACK.  */
            err = sctp_do_sm(SCTP_EVENT_T_OTHER,
                         SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
                         asoc->state, asoc->ep, asoc, NULL,
                         GFP_ATOMIC);
      } else {
            /* Windows may have opened, so we need
             * to check if we have DATA to transmit
             */
            err = sctp_outq_flush(&asoc->outqueue, 0);
      }

      return err;
}

/* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
 * the transport for a shutdown chunk.
 */
static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
                        struct sctp_association *asoc,
                        struct sctp_chunk *chunk)
{
      struct sctp_transport *t;

      t = sctp_assoc_choose_shutdown_transport(asoc);
      asoc->shutdown_last_sent_to = t;
      asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
      chunk->transport = t;
}

/* Helper function to change the state of an association. */
static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
                         struct sctp_association *asoc,
                         sctp_state_t state)
{
      struct sock *sk = asoc->base.sk;

      asoc->state = state;

      SCTP_DEBUG_PRINTK("sctp_cmd_new_state: asoc %p[%s]\n",
                    asoc, sctp_state_tbl[state]);

      if (sctp_style(sk, TCP)) {
            /* Change the sk->sk_state of a TCP-style socket that has
             * sucessfully completed a connect() call.
             */
            if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
                  sk->sk_state = SCTP_SS_ESTABLISHED;

            /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
            if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
                sctp_sstate(sk, ESTABLISHED))
                  sk->sk_shutdown |= RCV_SHUTDOWN;
      }

      if (sctp_state(asoc, COOKIE_WAIT)) {
            /* Reset init timeouts since they may have been
             * increased due to timer expirations.
             */
            asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
                                    asoc->rto_initial;
            asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
                                    asoc->rto_initial;
      }

      if (sctp_state(asoc, ESTABLISHED) ||
          sctp_state(asoc, CLOSED) ||
          sctp_state(asoc, SHUTDOWN_RECEIVED)) {
            /* Wake up any processes waiting in the asoc's wait queue in
             * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
             */
            if (waitqueue_active(&asoc->wait))
                  wake_up_interruptible(&asoc->wait);

            /* Wake up any processes waiting in the sk's sleep queue of
             * a TCP-style or UDP-style peeled-off socket in
             * sctp_wait_for_accept() or sctp_wait_for_packet().
             * For a UDP-style socket, the waiters are woken up by the
             * notifications.
             */
            if (!sctp_style(sk, UDP))
                  sk->sk_state_change(sk);
      }
}

/* Helper function to delete an association. */
static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
                        struct sctp_association *asoc)
{
      struct sock *sk = asoc->base.sk;

      /* If it is a non-temporary association belonging to a TCP-style
       * listening socket that is not closed, do not free it so that accept()
       * can pick it up later.
       */
      if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
          (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
            return;

      sctp_unhash_established(asoc);
      sctp_association_free(asoc);
}

/*
 * ADDIP Section 4.1 ASCONF Chunk Procedures
 * A4) Start a T-4 RTO timer, using the RTO value of the selected
 * destination address (we use active path instead of primary path just
 * because primary path may be inactive.
 */
static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
                        struct sctp_association *asoc,
                        struct sctp_chunk *chunk)
{
      struct sctp_transport *t;

      t = asoc->peer.active_path;
      asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
      chunk->transport = t;
}

/* Process an incoming Operation Error Chunk. */
static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
                           struct sctp_association *asoc,
                           struct sctp_chunk *chunk)
{
      struct sctp_operr_chunk *operr_chunk;
      struct sctp_errhdr *err_hdr;

      operr_chunk = (struct sctp_operr_chunk *)chunk->chunk_hdr;
      err_hdr = &operr_chunk->err_hdr;

      switch (err_hdr->cause) {
      case SCTP_ERROR_UNKNOWN_CHUNK:
      {
            struct sctp_chunkhdr *unk_chunk_hdr;

            unk_chunk_hdr = (struct sctp_chunkhdr *)err_hdr->variable;
            switch (unk_chunk_hdr->type) {
            /* ADDIP 4.1 A9) If the peer responds to an ASCONF with an
             * ERROR chunk reporting that it did not recognized the ASCONF
             * chunk type, the sender of the ASCONF MUST NOT send any
             * further ASCONF chunks and MUST stop its T-4 timer.
             */
            case SCTP_CID_ASCONF:
                  asoc->peer.asconf_capable = 0;
                  sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
                              SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
                  break;
            default:
                  break;
            }
            break;
      }
      default:
            break;
      }
}

/* Process variable FWDTSN chunk information. */
static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
                            struct sctp_chunk *chunk)
{
      struct sctp_fwdtsn_skip *skip;
      /* Walk through all the skipped SSNs */
      sctp_walk_fwdtsn(skip, chunk) {
            sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
      }

      return;
}

/* Helper function to remove the association non-primary peer
 * transports.
 */
static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
{
      struct sctp_transport *t;
      struct list_head *pos;
      struct list_head *temp;

      list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
            t = list_entry(pos, struct sctp_transport, transports);
            if (!sctp_cmp_addr_exact(&t->ipaddr,
                               &asoc->peer.primary_addr)) {
                  sctp_assoc_del_peer(asoc, &t->ipaddr);
            }
      }

      return;
}

/* Helper function to set sk_err on a 1-1 style socket. */
static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
{
      struct sock *sk = asoc->base.sk;

      if (!sctp_style(sk, UDP))
            sk->sk_err = error;
}

/* Helper function to generate an association change event */
static void sctp_cmd_assoc_change(sctp_cmd_seq_t *commands,
                         struct sctp_association *asoc,
                         u8 state)
{
      struct sctp_ulpevent *ev;

      ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
                                  asoc->c.sinit_num_ostreams,
                                  asoc->c.sinit_max_instreams,
                                  NULL, GFP_ATOMIC);
      if (ev)
            sctp_ulpq_tail_event(&asoc->ulpq, ev);
}

/* Helper function to generate an adaptation indication event */
static void sctp_cmd_adaptation_ind(sctp_cmd_seq_t *commands,
                            struct sctp_association *asoc)
{
      struct sctp_ulpevent *ev;

      ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);

      if (ev)
            sctp_ulpq_tail_event(&asoc->ulpq, ev);
}

/* These three macros allow us to pull the debugging code out of the
 * main flow of sctp_do_sm() to keep attention focused on the real
 * functionality there.
 */
#define DEBUG_PRE \
      SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
                    "ep %p, %s, %s, asoc %p[%s], %s\n", \
                    ep, sctp_evttype_tbl[event_type], \
                    (*debug_fn)(subtype), asoc, \
                    sctp_state_tbl[state], state_fn->name)

#define DEBUG_POST \
      SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
                    "asoc %p, status: %s\n", \
                    asoc, sctp_status_tbl[status])

#define DEBUG_POST_SFX \
      SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
                    error, asoc, \
                    sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
                    sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])

/*
 * This is the master state machine processing function.
 *
 * If you want to understand all of lksctp, this is a
 * good place to start.
 */
int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
             sctp_state_t state,
             struct sctp_endpoint *ep,
             struct sctp_association *asoc,
             void *event_arg,
             gfp_t gfp)
{
      sctp_cmd_seq_t commands;
      const sctp_sm_table_entry_t *state_fn;
      sctp_disposition_t status;
      int error = 0;
      typedef const char *(printfn_t)(sctp_subtype_t);

      static printfn_t *table[] = {
            NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
      };
      printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];

      /* Look up the state function, run it, and then process the
       * side effects.  These three steps are the heart of lksctp.
       */
      state_fn = sctp_sm_lookup_event(event_type, state, subtype);

      sctp_init_cmd_seq(&commands);

      DEBUG_PRE;
      status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands);
      DEBUG_POST;

      error = sctp_side_effects(event_type, subtype, state,
                          ep, asoc, event_arg, status,
                          &commands, gfp);
      DEBUG_POST_SFX;

      return error;
}

#undef DEBUG_PRE
#undef DEBUG_POST

/*****************************************************************
 * This the master state function side effect processing function.
 *****************************************************************/
static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
                       sctp_state_t state,
                       struct sctp_endpoint *ep,
                       struct sctp_association *asoc,
                       void *event_arg,
                       sctp_disposition_t status,
                       sctp_cmd_seq_t *commands,
                       gfp_t gfp)
{
      int error;

      /* FIXME - Most of the dispositions left today would be categorized
       * as "exceptional" dispositions.  For those dispositions, it
       * may not be proper to run through any of the commands at all.
       * For example, the command interpreter might be run only with
       * disposition SCTP_DISPOSITION_CONSUME.
       */
      if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
                                     ep, asoc,
                                     event_arg, status,
                                     commands, gfp)))
            goto bail;

      switch (status) {
      case SCTP_DISPOSITION_DISCARD:
            SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
                          "event_type %d, event_id %d\n",
                          state, event_type, subtype.chunk);
            break;

      case SCTP_DISPOSITION_NOMEM:
            /* We ran out of memory, so we need to discard this
             * packet.
             */
            /* BUG--we should now recover some memory, probably by
             * reneging...
             */
            error = -ENOMEM;
            break;

      case SCTP_DISPOSITION_DELETE_TCB:
            /* This should now be a command. */
            break;

      case SCTP_DISPOSITION_CONSUME:
      case SCTP_DISPOSITION_ABORT:
            /*
             * We should no longer have much work to do here as the
             * real work has been done as explicit commands above.
             */
            break;

      case SCTP_DISPOSITION_VIOLATION:
            if (net_ratelimit())
                  printk(KERN_ERR "sctp protocol violation state %d "
                         "chunkid %d\n", state, subtype.chunk);
            break;

      case SCTP_DISPOSITION_NOT_IMPL:
            printk(KERN_WARNING "sctp unimplemented feature in state %d, "
                   "event_type %d, event_id %d\n",
                   state, event_type, subtype.chunk);
            break;

      case SCTP_DISPOSITION_BUG:
            printk(KERN_ERR "sctp bug in state %d, "
                   "event_type %d, event_id %d\n",
                   state, event_type, subtype.chunk);
            BUG();
            break;

      default:
            printk(KERN_ERR "sctp impossible disposition %d "
                   "in state %d, event_type %d, event_id %d\n",
                   status, state, event_type, subtype.chunk);
            BUG();
            break;
      }

bail:
      return error;
}

/********************************************************************
 * 2nd Level Abstractions
 ********************************************************************/

/* This is the side-effect interpreter.  */
static int sctp_cmd_interpreter(sctp_event_t event_type,
                        sctp_subtype_t subtype,
                        sctp_state_t state,
                        struct sctp_endpoint *ep,
                        struct sctp_association *asoc,
                        void *event_arg,
                        sctp_disposition_t status,
                        sctp_cmd_seq_t *commands,
                        gfp_t gfp)
{
      int error = 0;
      int force;
      sctp_cmd_t *cmd;
      struct sctp_chunk *new_obj;
      struct sctp_chunk *chunk = NULL;
      struct sctp_packet *packet;
      struct list_head *pos;
      struct timer_list *timer;
      unsigned long timeout;
      struct sctp_transport *t;
      struct sctp_sackhdr sackh;
      int local_cork = 0;

      if (SCTP_EVENT_T_TIMEOUT != event_type)
            chunk = (struct sctp_chunk *) event_arg;

      /* Note:  This whole file is a huge candidate for rework.
       * For example, each command could either have its own handler, so
       * the loop would look like:
       *     while (cmds)
       *         cmd->handle(x, y, z)
       * --jgrimm
       */
      while (NULL != (cmd = sctp_next_cmd(commands))) {
            switch (cmd->verb) {
            case SCTP_CMD_NOP:
                  /* Do nothing. */
                  break;

            case SCTP_CMD_NEW_ASOC:
                  /* Register a new association.  */
                  if (local_cork) {
                        sctp_outq_uncork(&asoc->outqueue);
                        local_cork = 0;
                  }
                  asoc = cmd->obj.ptr;
                  /* Register with the endpoint.  */
                  sctp_endpoint_add_asoc(ep, asoc);
                  sctp_hash_established(asoc);
                  break;

            case SCTP_CMD_UPDATE_ASSOC:
                   sctp_assoc_update(asoc, cmd->obj.ptr);
                   break;

            case SCTP_CMD_PURGE_OUTQUEUE:
                   sctp_outq_teardown(&asoc->outqueue);
                   break;

            case SCTP_CMD_DELETE_TCB:
                  if (local_cork) {
                        sctp_outq_uncork(&asoc->outqueue);
                        local_cork = 0;
                  }
                  /* Delete the current association.  */
                  sctp_cmd_delete_tcb(commands, asoc);
                  asoc = NULL;
                  break;

            case SCTP_CMD_NEW_STATE:
                  /* Enter a new state.  */
                  sctp_cmd_new_state(commands, asoc, cmd->obj.state);
                  break;

            case SCTP_CMD_REPORT_TSN:
                  /* Record the arrival of a TSN.  */
                  sctp_tsnmap_mark(&asoc->peer.tsn_map, cmd->obj.u32);
                  break;

            case SCTP_CMD_REPORT_FWDTSN:
                  /* Move the Cumulattive TSN Ack ahead. */
                  sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);

                  /* purge the fragmentation queue */
                  sctp_ulpq_reasm_flushtsn(&asoc->ulpq, cmd->obj.u32);

                  /* Abort any in progress partial delivery. */
                  sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
                  break;

            case SCTP_CMD_PROCESS_FWDTSN:
                  sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr);
                  break;

            case SCTP_CMD_GEN_SACK:
                  /* Generate a Selective ACK.
                   * The argument tells us whether to just count
                   * the packet and MAYBE generate a SACK, or
                   * force a SACK out.
                   */
                  force = cmd->obj.i32;
                  error = sctp_gen_sack(asoc, force, commands);
                  break;

            case SCTP_CMD_PROCESS_SACK:
                  /* Process an inbound SACK.  */
                  error = sctp_cmd_process_sack(commands, asoc,
                                          cmd->obj.ptr);
                  break;

            case SCTP_CMD_GEN_INIT_ACK:
                  /* Generate an INIT ACK chunk.  */
                  new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
                                         0);
                  if (!new_obj)
                        goto nomem;

                  sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
                              SCTP_CHUNK(new_obj));
                  break;

            case SCTP_CMD_PEER_INIT:
                  /* Process a unified INIT from the peer.
                   * Note: Only used during INIT-ACK processing.  If
                   * there is an error just return to the outter
                   * layer which will bail.
                   */
                  error = sctp_cmd_process_init(commands, asoc, chunk,
                                          cmd->obj.ptr, gfp);
                  break;

            case SCTP_CMD_GEN_COOKIE_ECHO:
                  /* Generate a COOKIE ECHO chunk.  */
                  new_obj = sctp_make_cookie_echo(asoc, chunk);
                  if (!new_obj) {
                        if (cmd->obj.ptr)
                              sctp_chunk_free(cmd->obj.ptr);
                        goto nomem;
                  }
                  sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
                              SCTP_CHUNK(new_obj));

                  /* If there is an ERROR chunk to be sent along with
                   * the COOKIE_ECHO, send it, too.
                   */
                  if (cmd->obj.ptr)
                        sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
                                    SCTP_CHUNK(cmd->obj.ptr));

                  /* FIXME - Eventually come up with a cleaner way to
                   * enabling COOKIE-ECHO + DATA bundling during
                   * multihoming stale cookie scenarios, the following
                   * command plays with asoc->peer.retran_path to
                   * avoid the problem of sending the COOKIE-ECHO and
                   * DATA in different paths, which could result
                   * in the association being ABORTed if the DATA chunk
                   * is processed first by the server.  Checking the
                   * init error counter simply causes this command
                   * to be executed only during failed attempts of
                   * association establishment.
                   */
                  if ((asoc->peer.retran_path !=
                       asoc->peer.primary_path) &&
                      (asoc->init_err_counter > 0)) {
                        sctp_add_cmd_sf(commands,
                                    SCTP_CMD_FORCE_PRIM_RETRAN,
                                    SCTP_NULL());
                  }

                  break;

            case SCTP_CMD_GEN_SHUTDOWN:
                  /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
                   * Reset error counts.
                   */
                  asoc->overall_error_count = 0;

                  /* Generate a SHUTDOWN chunk.  */
                  new_obj = sctp_make_shutdown(asoc, chunk);
                  if (!new_obj)
                        goto nomem;
                  sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
                              SCTP_CHUNK(new_obj));
                  break;

            case SCTP_CMD_CHUNK_ULP:
                  /* Send a chunk to the sockets layer.  */
                  SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
                                "chunk_up:", cmd->obj.ptr,
                                "ulpq:", &asoc->ulpq);
                  sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
                                  GFP_ATOMIC);
                  break;

            case SCTP_CMD_EVENT_ULP:
                  /* Send a notification to the sockets layer.  */
                  SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
                                "event_up:",cmd->obj.ptr,
                                "ulpq:",&asoc->ulpq);
                  sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
                  break;

            case SCTP_CMD_REPLY:
                  /* If an caller has not already corked, do cork. */
                  if (!asoc->outqueue.cork) {
                        sctp_outq_cork(&asoc->outqueue);
                        local_cork = 1;
                  }
                  /* Send a chunk to our peer.  */
                  error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr);
                  break;

            case SCTP_CMD_SEND_PKT:
                  /* Send a full packet to our peer.  */
                  packet = cmd->obj.ptr;
                  sctp_packet_transmit(packet);
                  sctp_ootb_pkt_free(packet);
                  break;

            case SCTP_CMD_T1_RETRAN:
                  /* Mark a transport for retransmission.  */
                  sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
                              SCTP_RTXR_T1_RTX);
                  break;

            case SCTP_CMD_RETRAN:
                  /* Mark a transport for retransmission.  */
                  sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
                              SCTP_RTXR_T3_RTX);
                  break;

            case SCTP_CMD_TRANSMIT:
                  /* Kick start transmission. */
                  error = sctp_outq_uncork(&asoc->outqueue);
                  local_cork = 0;
                  break;

            case SCTP_CMD_ECN_CE:
                  /* Do delayed CE processing.   */
                  sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
                  break;

            case SCTP_CMD_ECN_ECNE:
                  /* Do delayed ECNE processing. */
                  new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
                                          chunk);
                  if (new_obj)
                        sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
                                    SCTP_CHUNK(new_obj));
                  break;

            case SCTP_CMD_ECN_CWR:
                  /* Do delayed CWR processing.  */
                  sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
                  break;

            case SCTP_CMD_SETUP_T2:
                  sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr);
                  break;

            case SCTP_CMD_TIMER_START:
                  timer = &asoc->timers[cmd->obj.to];
                  timeout = asoc->timeouts[cmd->obj.to];
                  BUG_ON(!timeout);

                  timer->expires = jiffies + timeout;
                  sctp_association_hold(asoc);
                  add_timer(timer);
                  break;

            case SCTP_CMD_TIMER_RESTART:
                  timer = &asoc->timers[cmd->obj.to];
                  timeout = asoc->timeouts[cmd->obj.to];
                  if (!mod_timer(timer, jiffies + timeout))
                        sctp_association_hold(asoc);
                  break;

            case SCTP_CMD_TIMER_STOP:
                  timer = &asoc->timers[cmd->obj.to];
                  if (timer_pending(timer) && del_timer(timer))
                        sctp_association_put(asoc);
                  break;

            case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
                  chunk = cmd->obj.ptr;
                  t = sctp_assoc_choose_init_transport(asoc);
                  asoc->init_last_sent_to = t;
                  chunk->transport = t;
                  t->init_sent_count++;
                  break;

            case SCTP_CMD_INIT_RESTART:
                  /* Do the needed accounting and updates
                   * associated with restarting an initialization
                   * timer. Only multiply the timeout by two if
                   * all transports have been tried at the current
                   * timeout.
                   */
                  t = asoc->init_last_sent_to;
                  asoc->init_err_counter++;

                  if (t->init_sent_count > (asoc->init_cycle + 1)) {
                        asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] *= 2;
                        if (asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] >
                            asoc->max_init_timeo) {
                              asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
                                    asoc->max_init_timeo;
                        }
                        asoc->init_cycle++;
                        SCTP_DEBUG_PRINTK(
                              "T1 INIT Timeout adjustment"
                              " init_err_counter: %d"
                              " cycle: %d"
                              " timeout: %ld\n",
                              asoc->init_err_counter,
                              asoc->init_cycle,
                              asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT]);
                  }

                  sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
                              SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
                  break;

            case SCTP_CMD_COOKIEECHO_RESTART:
                  /* Do the needed accounting and updates
                   * associated with restarting an initialization
                   * timer. Only multiply the timeout by two if
                   * all transports have been tried at the current
                   * timeout.
                   */
                  asoc->init_err_counter++;

                  asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] *= 2;
                  if (asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] >
                      asoc->max_init_timeo) {
                        asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
                              asoc->max_init_timeo;
                  }
                  SCTP_DEBUG_PRINTK(
                        "T1 COOKIE Timeout adjustment"
                        " init_err_counter: %d"
                        " timeout: %ld\n",
                        asoc->init_err_counter,
                        asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE]);

                  /* If we've sent any data bundled with
                   * COOKIE-ECHO we need to resend.
                   */
                  list_for_each(pos, &asoc->peer.transport_addr_list) {
                        t = list_entry(pos, struct sctp_transport,
                                     transports);
                        sctp_retransmit_mark(&asoc->outqueue, t,
                                  SCTP_RTXR_T1_RTX);
                  }

                  sctp_add_cmd_sf(commands,
                              SCTP_CMD_TIMER_RESTART,
                              SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
                  break;

            case SCTP_CMD_INIT_FAILED:
                  sctp_cmd_init_failed(commands, asoc, cmd->obj.err);
                  break;

            case SCTP_CMD_ASSOC_FAILED:
                  sctp_cmd_assoc_failed(commands, asoc, event_type,
                                    subtype, chunk, cmd->obj.err);
                  break;

            case SCTP_CMD_INIT_COUNTER_INC:
                  asoc->init_err_counter++;
                  break;

            case SCTP_CMD_INIT_COUNTER_RESET:
                  asoc->init_err_counter = 0;
                  asoc->init_cycle = 0;
                  break;

            case SCTP_CMD_REPORT_DUP:
                  sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
                                   cmd->obj.u32);
                  break;

            case SCTP_CMD_REPORT_BAD_TAG:
                  SCTP_DEBUG_PRINTK("vtag mismatch!\n");
                  break;

            case SCTP_CMD_STRIKE:
                  /* Mark one strike against a transport.  */
                  sctp_do_8_2_transport_strike(asoc, cmd->obj.transport);
                  break;

            case SCTP_CMD_TRANSPORT_RESET:
                  t = cmd->obj.transport;
                  sctp_cmd_transport_reset(commands, asoc, t);
                  break;

            case SCTP_CMD_TRANSPORT_ON:
                  t = cmd->obj.transport;
                  sctp_cmd_transport_on(commands, asoc, t, chunk);
                  break;

            case SCTP_CMD_HB_TIMERS_START:
                  sctp_cmd_hb_timers_start(commands, asoc);
                  break;

            case SCTP_CMD_HB_TIMER_UPDATE:
                  t = cmd->obj.transport;
                  sctp_cmd_hb_timer_update(commands, asoc, t);
                  break;

            case SCTP_CMD_HB_TIMERS_STOP:
                  sctp_cmd_hb_timers_stop(commands, asoc);
                  break;

            case SCTP_CMD_REPORT_ERROR:
                  error = cmd->obj.error;
                  break;

            case SCTP_CMD_PROCESS_CTSN:
                  /* Dummy up a SACK for processing. */
                  sackh.cum_tsn_ack = cmd->obj.be32;
                  sackh.a_rwnd = 0;
                  sackh.num_gap_ack_blocks = 0;
                  sackh.num_dup_tsns = 0;
                  sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
                              SCTP_SACKH(&sackh));
                  break;

            case SCTP_CMD_DISCARD_PACKET:
                  /* We need to discard the whole packet.  */
                  chunk->pdiscard = 1;
                  break;

            case SCTP_CMD_RTO_PENDING:
                  t = cmd->obj.transport;
                  t->rto_pending = 1;
                  break;

            case SCTP_CMD_PART_DELIVER:
                  sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
                                       GFP_ATOMIC);
                  break;

            case SCTP_CMD_RENEGE:
                  sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
                               GFP_ATOMIC);
                  break;

            case SCTP_CMD_SETUP_T4:
                  sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr);
                  break;

            case SCTP_CMD_PROCESS_OPERR:
                  sctp_cmd_process_operr(commands, asoc, chunk);
                  break;
            case SCTP_CMD_CLEAR_INIT_TAG:
                  asoc->peer.i.init_tag = 0;
                  break;
            case SCTP_CMD_DEL_NON_PRIMARY:
                  sctp_cmd_del_non_primary(asoc);
                  break;
            case SCTP_CMD_T3_RTX_TIMERS_STOP:
                  sctp_cmd_t3_rtx_timers_stop(commands, asoc);
                  break;
            case SCTP_CMD_FORCE_PRIM_RETRAN:
                  t = asoc->peer.retran_path;
                  asoc->peer.retran_path = asoc->peer.primary_path;
                  error = sctp_outq_uncork(&asoc->outqueue);
                  local_cork = 0;
                  asoc->peer.retran_path = t;
                  break;
            case SCTP_CMD_SET_SK_ERR:
                  sctp_cmd_set_sk_err(asoc, cmd->obj.error);
                  break;
            case SCTP_CMD_ASSOC_CHANGE:
                  sctp_cmd_assoc_change(commands, asoc,
                                    cmd->obj.u8);
                  break;
            case SCTP_CMD_ADAPTATION_IND:
                  sctp_cmd_adaptation_ind(commands, asoc);
                  break;

            case SCTP_CMD_ASSOC_SHKEY:
                  error = sctp_auth_asoc_init_active_key(asoc,
                                    GFP_ATOMIC);
                  break;

            default:
                  printk(KERN_WARNING "Impossible command: %u, %p\n",
                         cmd->verb, cmd->obj.ptr);
                  break;
            }

            if (error)
                  break;
      }

out:
      if (local_cork)
            sctp_outq_uncork(&asoc->outqueue);
      return error;
nomem:
      error = -ENOMEM;
      goto out;
}


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