/* SCTP kernel reference Implementation * Copyright (c) 1999-2000 Cisco, Inc. * Copyright (c) 1999-2001 Motorola, Inc. * Copyright (c) 2001-2002 International Business Machines Corp. * Copyright (c) 2001 Intel Corp. * Copyright (c) 2001 La Monte H.P. Yarroll * * This file is part of the SCTP kernel reference Implementation * * This module provides the abstraction for an SCTP association. * * 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@us.ibm.com> * Xingang Guo <xingang.guo@intel.com> * Hui Huang <hui.huang@nokia.com> * Sridhar Samudrala <sri@us.ibm.com> * Daisy Chang <daisyc@us.ibm.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/types.h> #include <linux/fcntl.h> #include <linux/poll.h> #include <linux/init.h> #include <linux/sched.h> #include <linux/sched.h> #include <linux/slab.h> #include <linux/in.h> #include <net/ipv6.h> #include <net/sctp/sctp.h> /* Forward declarations for internal functions. */ static void sctp_assoc_bh_rcv(sctp_association_t *asoc); /* 1st Level Abstractions. */ /* Allocate and initialize a new association */ sctp_association_t *sctp_association_new(const sctp_endpoint_t *ep, const struct sock *sk, sctp_scope_t scope, int priority) { sctp_association_t *asoc; asoc = t_new(sctp_association_t, priority); if (!asoc) goto fail; if (!sctp_association_init(asoc, ep, sk, scope, priority)) goto fail_init; asoc->base.malloced = 1; SCTP_DBG_OBJCNT_INC(assoc); return asoc; fail_init: kfree(asoc); fail: return NULL; } /* Intialize a new association from provided memory. */ sctp_association_t *sctp_association_init(sctp_association_t *asoc, const sctp_endpoint_t *ep, const struct sock *sk, sctp_scope_t scope, int priority) { sctp_opt_t *sp; int i; /* Retrieve the SCTP per socket area. */ sp = sctp_sk((struct sock *)sk); /* Init all variables to a known value. */ memset(asoc, 0, sizeof(sctp_association_t)); /* Discarding const is appropriate here. */ asoc->ep = (sctp_endpoint_t *)ep; sctp_endpoint_hold(asoc->ep); /* Hold the sock. */ asoc->base.sk = (struct sock *)sk; sock_hold(asoc->base.sk); /* Initialize the common base substructure. */ asoc->base.type = SCTP_EP_TYPE_ASSOCIATION; /* Initialize the object handling fields. */ atomic_set(&asoc->base.refcnt, 1); asoc->base.dead = 0; asoc->base.malloced = 0; /* Initialize the bind addr area. */ sctp_bind_addr_init(&asoc->base.bind_addr, ep->base.bind_addr.port); asoc->base.addr_lock = RW_LOCK_UNLOCKED; asoc->state = SCTP_STATE_CLOSED; asoc->state_timestamp = jiffies; /* Set things that have constant value. */ asoc->cookie_life.tv_sec = SCTP_DEFAULT_COOKIE_LIFE_SEC; asoc->cookie_life.tv_usec = SCTP_DEFAULT_COOKIE_LIFE_USEC; asoc->pmtu = 0; asoc->frag_point = 0; /* Initialize the default association max_retrans and RTO values. */ asoc->max_retrans = ep->proto->max_retrans_association; asoc->rto_initial = ep->proto->rto_initial; asoc->rto_max = ep->proto->rto_max; asoc->rto_min = ep->proto->rto_min; asoc->overall_error_threshold = 0; asoc->overall_error_count = 0; /* Initialize the maximum mumber of new data packets that can be sent * in a burst. */ asoc->max_burst = ep->proto->max_burst; /* Copy things from the endpoint. */ for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) { asoc->timeouts[i] = ep->timeouts[i]; init_timer(&asoc->timers[i]); asoc->timers[i].function = sctp_timer_events[i]; asoc->timers[i].data = (unsigned long) asoc; } /* Pull default initialization values from the sock options. * Note: This assumes that the values have already been * validated in the sock. */ asoc->c.sinit_max_instreams = sp->initmsg.sinit_max_instreams; asoc->c.sinit_num_ostreams = sp->initmsg.sinit_num_ostreams; asoc->max_init_attempts = sp->initmsg.sinit_max_attempts; asoc->max_init_timeo = sp->initmsg.sinit_max_init_timeo * HZ; /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number * * The stream sequence number in all the streams shall start * from 0 when the association is established. Also, when the * stream sequence number reaches the value 65535 the next * stream sequence number shall be set to 0. */ for (i = 0; i < SCTP_MAX_STREAM; i++) asoc->ssn[i] = 0; /* Set the local window size for receive. * This is also the rcvbuf space per association. * RFC 6 - A SCTP receiver MUST be able to receive a minimum of * 1500 bytes in one SCTP packet. */ if (sk->rcvbuf < SCTP_DEFAULT_MINWINDOW) asoc->rwnd = SCTP_DEFAULT_MINWINDOW; else asoc->rwnd = sk->rcvbuf; asoc->rwnd_over = 0; /* Use my own max window until I learn something better. */ asoc->peer.rwnd = SCTP_DEFAULT_MAXWINDOW; /* Set the sndbuf size for transmit. */ asoc->sndbuf_used = 0; init_waitqueue_head(&asoc->wait); asoc->c.my_vtag = sctp_generate_tag(ep); asoc->peer.i.init_tag = 0; /* INIT needs a vtag of 0. */ asoc->c.peer_vtag = 0; asoc->c.my_ttag = 0; asoc->c.peer_ttag = 0; asoc->c.initial_tsn = sctp_generate_tsn(ep); asoc->next_tsn = asoc->c.initial_tsn; asoc->ctsn_ack_point = asoc->next_tsn - 1; asoc->highest_sacked = asoc->ctsn_ack_point; asoc->last_cwr_tsn = asoc->ctsn_ack_point; asoc->unack_data = 0; SCTP_DEBUG_PRINTK("myctsnap for %s INIT as 0x%x.\n", asoc->ep->debug_name, asoc->ctsn_ack_point); /* ADDIP Section 4.1 Asconf Chunk Procedures * * When an endpoint has an ASCONF signaled change to be sent to the * remote endpoint it should do the following: * ... * A2) a serial number should be assigned to the chunk. The serial * number should be a monotonically increasing number. All serial * numbers are defined to be initialized at the start of the * association to the same value as the initial TSN. */ asoc->addip_serial = asoc->c.initial_tsn; /* Make an empty list of remote transport addresses. */ INIT_LIST_HEAD(&asoc->peer.transport_addr_list); /* RFC 2960 5.1 Normal Establishment of an Association * * After the reception of the first data chunk in an * association the endpoint must immediately respond with a * sack to acknowledge the data chunk. Subsequent * acknowledgements should be done as described in Section * 6.2. * * [We implement this by telling a new association that it * already received one packet.] */ asoc->peer.sack_needed = 1; /* Create an input queue. */ sctp_inqueue_init(&asoc->base.inqueue); sctp_inqueue_set_th_handler(&asoc->base.inqueue, (void (*)(void *))sctp_assoc_bh_rcv, asoc); /* Create an output queue. */ sctp_outqueue_init(asoc, &asoc->outqueue); sctp_outqueue_set_output_handlers(&asoc->outqueue, sctp_packet_init, sctp_packet_config, sctp_packet_append_chunk, sctp_packet_transmit_chunk, sctp_packet_transmit); if (NULL == sctp_ulpqueue_init(&asoc->ulpq, asoc, SCTP_MAX_STREAM)) goto fail_init; /* Set up the tsn tracking. */ sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_SIZE, 0); asoc->peer.next_dup_tsn = 0; skb_queue_head_init(&asoc->addip_chunks); asoc->need_ecne = 0; asoc->debug_name = "unnamedasoc"; asoc->eyecatcher = SCTP_ASSOC_EYECATCHER; /* Assume that peer would support both address types unless we are * told otherwise. */ asoc->peer.ipv4_address = 1; asoc->peer.ipv6_address = 1; INIT_LIST_HEAD(&asoc->asocs); asoc->autoclose = sp->autoclose; return asoc; fail_init: sctp_endpoint_put(asoc->ep); sock_put(asoc->base.sk); return NULL; } /* Free this association if possible. There may still be users, so * the actual deallocation may be delayed. */ void sctp_association_free(sctp_association_t *asoc) { sctp_transport_t *transport; sctp_endpoint_t *ep; struct list_head *pos, *temp; int i; ep = asoc->ep; list_del(&asoc->asocs); /* Mark as dead, so other users can know this structure is * going away. */ asoc->base.dead = 1; /* Dispose of any data lying around in the outqueue. */ sctp_outqueue_free(&asoc->outqueue); /* Dispose of any pending messages for the upper layer. */ sctp_ulpqueue_free(&asoc->ulpq); /* Dispose of any pending chunks on the inqueue. */ sctp_inqueue_free(&asoc->base.inqueue); /* Clean up the bound address list. */ sctp_bind_addr_free(&asoc->base.bind_addr); /* Do we need to go through all of our timers and * delete them? To be safe we will try to delete all, but we * should be able to go through and make a guess based * on our state. */ for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) { if (timer_pending(&asoc->timers[i]) && del_timer(&asoc->timers[i])) sctp_association_put(asoc); } /* Free peer's cached cookie. */ if (asoc->peer.cookie) { kfree(asoc->peer.cookie); } /* Release the transport structures. */ list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) { transport = list_entry(pos, sctp_transport_t, transports); list_del(pos); sctp_transport_free(transport); } asoc->eyecatcher = 0; sctp_association_put(asoc); } /* Cleanup and free up an association. */ static void sctp_association_destroy(sctp_association_t *asoc) { SCTP_ASSERT(asoc->base.dead, "Assoc is not dead", return); sctp_endpoint_put(asoc->ep); sock_put(asoc->base.sk); if (asoc->base.malloced) { kfree(asoc); SCTP_DBG_OBJCNT_DEC(assoc); } } /* Add a transport address to an association. */ sctp_transport_t *sctp_assoc_add_peer(sctp_association_t *asoc, const union sctp_addr *addr, int priority) { sctp_transport_t *peer; sctp_opt_t *sp; const __u16 *port; switch (addr->sa.sa_family) { case AF_INET: port = &addr->v4.sin_port; break; case AF_INET6: SCTP_V6( port = &addr->v6.sin6_port; break; ); default: return NULL; }; /* Set the port if it has not been set yet. */ if (0 == asoc->peer.port) { asoc->peer.port = *port; } SCTP_ASSERT(*port == asoc->peer.port, ":Invalid port\n", return NULL); /* Check to see if this is a duplicate. */ peer = sctp_assoc_lookup_paddr(asoc, addr); if (peer) return peer; peer = sctp_transport_new(addr, priority); if (NULL == peer) return NULL; sctp_transport_set_owner(peer, asoc); /* Cache a route for the transport. */ sctp_transport_route(peer, NULL); /* If this is the first transport addr on this association, * initialize the association PMTU to the peer's PMTU. * If not and the current association PMTU is higher than the new * peer's PMTU, reset the association PMTU to the new peer's PMTU. */ if (asoc->pmtu) { asoc->pmtu = min_t(int, peer->pmtu, asoc->pmtu); } else { asoc->pmtu = peer->pmtu; } SCTP_DEBUG_PRINTK("sctp_assoc_add_peer:association %p PMTU set to " "%d\n", asoc, asoc->pmtu); asoc->frag_point = asoc->pmtu - (SCTP_IP_OVERHEAD + sizeof(sctp_data_chunk_t)); /* The asoc->peer.port might not be meaningful yet, but * initialize the packet structure anyway. */ (asoc->outqueue.init_output)(&peer->packet, peer, asoc->base.bind_addr.port, asoc->peer.port); /* 7.2.1 Slow-Start * * o The initial cwnd before data transmission or after a * sufficiently long idle period MUST be <= 2*MTU. * * o The initial value of ssthresh MAY be arbitrarily high * (for example, implementations MAY use the size of the * receiver advertised window). */ peer->cwnd = asoc->pmtu * 2; /* At this point, we may not have the receiver's advertised window, * so initialize ssthresh to the default value and it will be set * later when we process the INIT. */ peer->ssthresh = SCTP_DEFAULT_MAXWINDOW; peer->partial_bytes_acked = 0; peer->flight_size = 0; peer->error_threshold = peer->max_retrans; /* Update the overall error threshold value of the association * taking the new peer's error threshold into account. */ asoc->overall_error_threshold = min(asoc->overall_error_threshold + peer->error_threshold, asoc->max_retrans); /* By default, enable heartbeat for peer address. */ peer->hb_allowed = 1; /* Initialize the peer's heartbeat interval based on the * sock configured value. */ sp = sctp_sk(asoc->base.sk); peer->hb_interval = sp->paddrparam.spp_hbinterval * HZ; /* Attach the remote transport to our asoc. */ list_add_tail(&peer->transports, &asoc->peer.transport_addr_list); /* If we do not yet have a primary path, set one. */ if (NULL == asoc->peer.primary_path) { asoc->peer.primary_path = peer; /* Set a default msg_name for events. */ memcpy(&asoc->peer.primary_addr, &peer->ipaddr, sizeof(union sctp_addr)); asoc->peer.active_path = peer; asoc->peer.retran_path = peer; } if (asoc->peer.active_path == asoc->peer.retran_path) asoc->peer.retran_path = peer; return peer; } /* Lookup a transport by address. */ sctp_transport_t *sctp_assoc_lookup_paddr(const sctp_association_t *asoc, const union sctp_addr *address) { sctp_transport_t *t; struct list_head *pos; /* Cycle through all transports searching for a peer address. */ list_for_each(pos, &asoc->peer.transport_addr_list) { t = list_entry(pos, sctp_transport_t, transports); if (sctp_cmp_addr_exact(address, &t->ipaddr)) return t; } return NULL; } /* Engage in transport control operations. * Mark the transport up or down and send a notification to the user. * Select and update the new active and retran paths. */ void sctp_assoc_control_transport(sctp_association_t *asoc, sctp_transport_t *transport, sctp_transport_cmd_t command, sctp_sn_error_t error) { sctp_transport_t *t = NULL; sctp_transport_t *first; sctp_transport_t *second; sctp_ulpevent_t *event; struct list_head *pos; int spc_state = 0; /* Record the transition on the transport. */ switch (command) { case SCTP_TRANSPORT_UP: transport->active = 1; spc_state = ADDRESS_AVAILABLE; break; case SCTP_TRANSPORT_DOWN: transport->active = 0; spc_state = ADDRESS_UNREACHABLE; break; default: BUG(); }; /* Generate and send a SCTP_PEER_ADDR_CHANGE notification to the * user. */ event = sctp_ulpevent_make_peer_addr_change(asoc, (struct sockaddr_storage *) &transport->ipaddr, 0, spc_state, error, GFP_ATOMIC); if (event) sctp_ulpqueue_tail_event(&asoc->ulpq, event); /* Select new active and retran paths. */ /* Look for the two most recently used active transports. * * This code produces the wrong ordering whenever jiffies * rolls over, but we still get usable transports, so we don't * worry about it. */ first = NULL; second = NULL; list_for_each(pos, &asoc->peer.transport_addr_list) { t = list_entry(pos, sctp_transport_t, transports); if (!t->active) continue; if (!first || t->last_time_heard > first->last_time_heard) { second = first; first = t; } if (!second || t->last_time_heard > second->last_time_heard) second = t; } /* RFC 2960 6.4 Multi-Homed SCTP Endpoints * * By default, an endpoint should always transmit to the * primary path, unless the SCTP user explicitly specifies the * destination transport address (and possibly source * transport address) to use. * * [If the primary is active but not most recent, bump the most * recently used transport.] */ if (asoc->peer.primary_path->active && first != asoc->peer.primary_path) { second = first; first = asoc->peer.primary_path; } /* If we failed to find a usable transport, just camp on the * primary, even if it is inactive. */ if (NULL == first) { first = asoc->peer.primary_path; second = asoc->peer.primary_path; } /* Set the active and retran transports. */ asoc->peer.active_path = first; asoc->peer.retran_path = second; } /* Hold a reference to an association. */ void sctp_association_hold(sctp_association_t *asoc) { atomic_inc(&asoc->base.refcnt); } /* Release a reference to an association and cleanup * if there are no more references. */ void sctp_association_put(sctp_association_t *asoc) { if (atomic_dec_and_test(&asoc->base.refcnt)) sctp_association_destroy(asoc); } /* Allocate the next TSN, Transmission Sequence Number, for the given * association. */ __u32 __sctp_association_get_next_tsn(sctp_association_t *asoc) { /* From Section 1.6 Serial Number Arithmetic: * Transmission Sequence Numbers wrap around when they reach * 2**32 - 1. That is, the next TSN a DATA chunk MUST use * after transmitting TSN = 2*32 - 1 is TSN = 0. */ __u32 retval = asoc->next_tsn; asoc->next_tsn++; asoc->unack_data++; return retval; } /* Allocate 'num' TSNs by incrementing the association's TSN by num. */ __u32 __sctp_association_get_tsn_block(sctp_association_t *asoc, int num) { __u32 retval = asoc->next_tsn; asoc->next_tsn += num; asoc->unack_data += num; return retval; } /* Fetch the next Stream Sequence Number for stream number 'sid'. */ __u16 __sctp_association_get_next_ssn(sctp_association_t *asoc, __u16 sid) { return asoc->ssn[sid]++; } /* Compare two addresses to see if they match. Wildcard addresses * always match within their address family. * * FIXME: We do not match address scopes correctly. */ int sctp_cmp_addr(const union sctp_addr *ss1, const union sctp_addr *ss2) { int len; const void *base1; const void *base2; if (ss1->sa.sa_family != ss2->sa.sa_family) return 0; if (ss1->v4.sin_port != ss2->v4.sin_port) return 0; switch (ss1->sa.sa_family) { case AF_INET: if (INADDR_ANY == ss1->v4.sin_addr.s_addr || INADDR_ANY == ss2->v4.sin_addr.s_addr) goto match; len = sizeof(struct in_addr); base1 = &ss1->v4.sin_addr; base2 = &ss2->v4.sin_addr; break; case AF_INET6: SCTP_V6( if (IPV6_ADDR_ANY == sctp_ipv6_addr_type(&ss1->v6.sin6_addr)) goto match; if (IPV6_ADDR_ANY == sctp_ipv6_addr_type(&ss2->v6.sin6_addr)) goto match; len = sizeof(struct in6_addr); base1 = &ss1->v6.sin6_addr; base2 = &ss2->v6.sin6_addr; break; ) default: printk(KERN_WARNING "WARNING, bogus socket address family %d\n", ss1->sa.sa_family); return 0; }; return (0 == memcmp(base1, base2, len)); match: return 1; } /* Compare two addresses to see if they match. Wildcard addresses * only match themselves. * * FIXME: We do not match address scopes correctly. */ int sctp_cmp_addr_exact(const union sctp_addr *ss1, const union sctp_addr *ss2) { int len; const void *base1; const void *base2; if (ss1->sa.sa_family != ss2->sa.sa_family) return 0; if (ss1->v4.sin_port != ss2->v4.sin_port) return 0; switch (ss1->sa.sa_family) { case AF_INET: len = sizeof(struct in_addr); base1 = &ss1->v4.sin_addr; base2 = &ss2->v4.sin_addr; break; case AF_INET6: SCTP_V6( len = sizeof(struct in6_addr); base1 = &ss1->v6.sin6_addr; base2 = &ss2->v6.sin6_addr; break; ) default: printk(KERN_WARNING "WARNING, bogus socket address family %d\n", ss1->sa.sa_family); return 0; }; return (0 == memcmp(base1, base2, len)); } /* Return an ecne chunk to get prepended to a packet. * Note: We are sly and return a shared, prealloced chunk. */ sctp_chunk_t *sctp_get_ecne_prepend(sctp_association_t *asoc) { sctp_chunk_t *chunk; int need_ecne; __u32 lowest_tsn; /* Can be called from task or bh. Both need_ecne and * last_ecne_tsn are written during bh. */ need_ecne = asoc->need_ecne; lowest_tsn = asoc->last_ecne_tsn; if (need_ecne) { chunk = sctp_make_ecne(asoc, lowest_tsn); /* ECNE is not mandatory to the flow. Being unable to * alloc mem is not deadly. We are just unable to help * out the network. If we run out of memory, just return * NULL. */ } else { chunk = NULL; } return chunk; } /* Use this function for the packet prepend callback when no ECNE * packet is desired (e.g. some packets don't like to be bundled). */ sctp_chunk_t *sctp_get_no_prepend(sctp_association_t *asoc) { return NULL; } /* * Find which transport this TSN was sent on. */ sctp_transport_t *sctp_assoc_lookup_tsn(sctp_association_t *asoc, __u32 tsn) { sctp_transport_t *active; sctp_transport_t *match; struct list_head *entry, *pos; sctp_transport_t *transport; sctp_chunk_t *chunk; __u32 key = htonl(tsn); match = NULL; /* * FIXME: In general, find a more efficient data structure for * searching. */ /* * The general strategy is to search each transport's transmitted * list. Return which transport this TSN lives on. * * Let's be hopeful and check the active_path first. * Another optimization would be to know if there is only one * outbound path and not have to look for the TSN at all. * */ active = asoc->peer.active_path; list_for_each(entry, &active->transmitted) { chunk = list_entry(entry, sctp_chunk_t, transmitted_list); if (key == chunk->subh.data_hdr->tsn) { match = active; goto out; } } /* If not found, go search all the other transports. */ list_for_each(pos, &asoc->peer.transport_addr_list) { transport = list_entry(pos, sctp_transport_t, transports); if (transport == active) break; list_for_each(entry, &transport->transmitted) { chunk = list_entry(entry, sctp_chunk_t, transmitted_list); if (key == chunk->subh.data_hdr->tsn) { match = transport; goto out; } } } out: return match; } /* Is this the association we are looking for? */ sctp_transport_t *sctp_assoc_is_match(sctp_association_t *asoc, const union sctp_addr *laddr, const union sctp_addr *paddr) { sctp_transport_t *transport; sctp_read_lock(&asoc->base.addr_lock); if ((asoc->base.bind_addr.port == laddr->v4.sin_port) && (asoc->peer.port == paddr->v4.sin_port)) { transport = sctp_assoc_lookup_paddr(asoc, paddr); if (!transport) goto out; if (sctp_bind_addr_has_addr(&asoc->base.bind_addr, laddr)) goto out; } transport = NULL; out: sctp_read_unlock(&asoc->base.addr_lock); return transport; } /* Do delayed input processing. This is scheduled by sctp_rcv(). */ static void sctp_assoc_bh_rcv(sctp_association_t *asoc) { sctp_endpoint_t *ep; sctp_chunk_t *chunk; struct sock *sk; sctp_inqueue_t *inqueue; int state, subtype; sctp_assoc_t associd = sctp_assoc2id(asoc); int error = 0; /* The association should be held so we should be safe. */ ep = asoc->ep; sk = asoc->base.sk; inqueue = &asoc->base.inqueue; while (NULL != (chunk = sctp_pop_inqueue(inqueue))) { state = asoc->state; subtype = chunk->chunk_hdr->type; /* Remember where the last DATA chunk came from so we * know where to send the SACK. */ if (sctp_chunk_is_data(chunk)) asoc->peer.last_data_from = chunk->transport; if (chunk->transport) chunk->transport->last_time_heard = jiffies; /* Run through the state machine. */ error = sctp_do_sm(SCTP_EVENT_T_CHUNK, SCTP_ST_CHUNK(subtype), state, ep, asoc, chunk, GFP_ATOMIC); /* Check to see if the association is freed in response to * the incoming chunk. If so, get out of the while loop. */ if (!sctp_id2assoc(sk, associd)) break; /* If there is an error on chunk, discard this packet. */ if (error && chunk) chunk->pdiscard = 1; } } /* This routine moves an association from its old sk to a new sk. */ void sctp_assoc_migrate(sctp_association_t *assoc, struct sock *newsk) { sctp_opt_t *newsp = sctp_sk(newsk); /* Delete the association from the old endpoint's list of * associations. */ list_del(&assoc->asocs); /* Release references to the old endpoint and the sock. */ sctp_endpoint_put(assoc->ep); sock_put(assoc->base.sk); /* Get a reference to the new endpoint. */ assoc->ep = newsp->ep; sctp_endpoint_hold(assoc->ep); /* Get a reference to the new sock. */ assoc->base.sk = newsk; sock_hold(assoc->base.sk); /* Add the association to the new endpoint's list of associations. */ sctp_endpoint_add_asoc(newsp->ep, assoc); } /* Update an association (possibly from unexpected COOKIE-ECHO processing). */ void sctp_assoc_update(sctp_association_t *asoc, sctp_association_t *new) { int i; /* Copy in new parameters of peer. */ asoc->c = new->c; asoc->peer.rwnd = new->peer.rwnd; asoc->peer.next_dup_tsn = new->peer.next_dup_tsn; asoc->peer.sack_needed = new->peer.sack_needed; asoc->peer.i = new->peer.i; sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_SIZE, asoc->peer.i.initial_tsn); /* FIXME: * Do we need to copy primary_path etc? * * More explicitly, addresses may have been removed and * this needs accounting for. */ /* If the case is A (association restart), use * initial_tsn as next_tsn. If the case is B, use * current next_tsn in case there is data sent to peer * has been discarded and needs retransmission. */ if (SCTP_STATE_ESTABLISHED == asoc->state) { asoc->next_tsn = new->next_tsn; asoc->ctsn_ack_point = new->ctsn_ack_point; /* Reinitialize SSN for both local streams * and peer's streams. */ for (i = 0; i < SCTP_MAX_STREAM; i++) { asoc->ssn[i] = 0; asoc->ulpq.ssn[i] = 0; } } else { asoc->ctsn_ack_point = asoc->next_tsn - 1; } } /* Choose the transport for sending a shutdown packet. * Round-robin through the active transports, else round-robin * through the inactive transports as this is the next best thing * we can try. */ sctp_transport_t *sctp_assoc_choose_shutdown_transport(sctp_association_t *asoc) { sctp_transport_t *t, *next; struct list_head *head = &asoc->peer.transport_addr_list; struct list_head *pos; /* If this is the first time SHUTDOWN is sent, use the active * path. */ if (!asoc->shutdown_last_sent_to) return asoc->peer.active_path; /* Otherwise, find the next transport in a round-robin fashion. */ t = asoc->shutdown_last_sent_to; pos = &t->transports; next = NULL; while (1) { /* Skip the head. */ if (pos->next == head) pos = head->next; else pos = pos->next; t = list_entry(pos, sctp_transport_t, transports); /* Try to find an active transport. */ if (t->active) { break; } else { /* Keep track of the next transport in case * we don't find any active transport. */ if (!next) next = t; } /* We have exhausted the list, but didn't find any * other active transports. If so, use the next * transport. */ if (t == asoc->shutdown_last_sent_to) { t = next; break; } } return t; }