| /* SCTP kernel reference Implementation |
| * Copyright (c) 1999-2000 Cisco, Inc. |
| * Copyright (c) 1999-2001 Motorola, Inc. |
| * Copyright (c) 2001-2003 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/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_proto.valid_cookie_life / HZ; |
| asoc->cookie_life.tv_usec = (sctp_proto.valid_cookie_life % HZ) * |
| 1000000L / HZ; |
| |
| 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; |
| |
| /* Allocate storage for the ssnmap after the inbound and outbound |
| * streams have been negotiated during Init. |
| */ |
| asoc->ssnmap = NULL; |
| |
| /* 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->a_rwnd = 0; |
| |
| 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_outq_init(asoc, &asoc->outqueue); |
| sctp_outq_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_ulpq_init(&asoc->ulpq, asoc)) |
| 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) |
| { |
| struct sctp_transport *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_outq_free(&asoc->outqueue); |
| |
| /* Dispose of any pending messages for the upper layer. */ |
| sctp_ulpq_free(&asoc->ulpq); |
| |
| /* Dispose of any pending chunks on the inqueue. */ |
| sctp_inqueue_free(&asoc->base.inqueue); |
| |
| /* Free ssnmap storage. */ |
| sctp_ssnmap_free(asoc->ssnmap); |
| |
| /* 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, struct sctp_transport, 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. */ |
| struct sctp_transport *sctp_assoc_add_peer(sctp_association_t *asoc, |
| const union sctp_addr *addr, |
| int priority) |
| { |
| struct sctp_transport *peer; |
| sctp_opt_t *sp; |
| unsigned short port; |
| |
| /* AF_INET and AF_INET6 share common port field. */ |
| port = addr->v4.sin_port; |
| |
| /* Set the port if it has not been set yet. */ |
| if (0 == asoc->peer.port) { |
| asoc->peer.port = port; |
| } |
| |
| /* 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 (!peer) |
| return NULL; |
| |
| sctp_transport_set_owner(peer, asoc); |
| |
| /* Initialize the pmtu of the transport. */ |
| sctp_transport_pmtu(peer); |
| |
| /* 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. */ |
| struct sctp_transport *sctp_assoc_lookup_paddr(const sctp_association_t *asoc, |
| const union sctp_addr *address) |
| { |
| struct sctp_transport *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, struct sctp_transport, 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, |
| struct sctp_transport *transport, |
| sctp_transport_cmd_t command, |
| sctp_sn_error_t error) |
| { |
| struct sctp_transport *t = NULL; |
| struct sctp_transport *first; |
| struct sctp_transport *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: |
| return; |
| }; |
| |
| /* 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_ulpq_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, struct sctp_transport, 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; |
| } |
| |
| |
| /* 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) |
| { |
| struct sctp_af *af; |
| |
| af = sctp_get_af_specific(ss1->sa.sa_family); |
| if (!af) |
| return 0; |
| |
| return af->cmp_addr(ss1, ss2); |
| } |
| |
| /* 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. |
| */ |
| struct sctp_transport *sctp_assoc_lookup_tsn(sctp_association_t *asoc, __u32 tsn) |
| { |
| struct sctp_transport *active; |
| struct sctp_transport *match; |
| struct list_head *entry, *pos; |
| struct sctp_transport *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, struct sctp_transport, 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? */ |
| struct sctp_transport *sctp_assoc_is_match(sctp_association_t *asoc, |
| const union sctp_addr *laddr, |
| const union sctp_addr *paddr) |
| { |
| struct sctp_transport *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_match(&asoc->base.bind_addr, laddr, |
| sctp_sk(asoc->base.sk))) |
| 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) |
| { |
| /* 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 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. |
| */ |
| sctp_ssnmap_clear(asoc->ssnmap); |
| |
| } else { |
| asoc->ctsn_ack_point = asoc->next_tsn - 1; |
| if (!asoc->ssnmap) { |
| /* Move the ssnmap. */ |
| asoc->ssnmap = new->ssnmap; |
| new->ssnmap = NULL; |
| } |
| } |
| |
| } |
| |
| /* 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. |
| */ |
| struct sctp_transport *sctp_assoc_choose_shutdown_transport(sctp_association_t *asoc) |
| { |
| struct sctp_transport *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, struct sctp_transport, 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; |
| } |
| |
| /* Update the association's pmtu and frag_point by going through all the |
| * transports. This routine is called when a transport's PMTU has changed. |
| */ |
| void sctp_assoc_sync_pmtu(sctp_association_t *asoc) |
| { |
| struct sctp_transport *t; |
| struct list_head *pos; |
| __u32 pmtu = 0; |
| |
| if (!asoc) |
| return; |
| |
| /* Get the lowest pmtu of all the transports. */ |
| list_for_each(pos, &asoc->peer.transport_addr_list) { |
| t = list_entry(pos, struct sctp_transport, transports); |
| if (!pmtu || (t->pmtu < pmtu)) |
| pmtu = t->pmtu; |
| } |
| |
| if (pmtu) { |
| asoc->pmtu = pmtu; |
| asoc->frag_point = pmtu - (SCTP_IP_OVERHEAD + |
| sizeof(sctp_data_chunk_t)); |
| } |
| |
| SCTP_DEBUG_PRINTK("%s: asoc:%p, pmtu:%d, frag_point:%d\n", |
| __FUNCTION__, asoc, asoc->pmtu, asoc->frag_point); |
| } |
| |
| /* Increase asoc's rwnd by len and send any window update SACK if needed. */ |
| void sctp_assoc_rwnd_increase(sctp_association_t *asoc, int len) |
| { |
| sctp_chunk_t *sack; |
| struct timer_list *timer; |
| |
| if (asoc->rwnd_over) { |
| if (asoc->rwnd_over >= len) { |
| asoc->rwnd_over -= len; |
| } else { |
| asoc->rwnd += (len - asoc->rwnd_over); |
| asoc->rwnd_over = 0; |
| } |
| } else { |
| asoc->rwnd += len; |
| } |
| |
| SCTP_DEBUG_PRINTK("%s: asoc %p rwnd increased by %d to (%u, %u) - %u\n", |
| __FUNCTION__, asoc, len, asoc->rwnd, asoc->rwnd_over, |
| asoc->a_rwnd); |
| |
| /* Send a window update SACK if the rwnd has increased by at least the |
| * minimum of the association's PMTU and half of the receive buffer. |
| * The algorithm used is similar to the one described in |
| * Section 4.2.3.3 of RFC 1122. |
| */ |
| if ((asoc->state == SCTP_STATE_ESTABLISHED) && |
| (asoc->rwnd > asoc->a_rwnd) && |
| ((asoc->rwnd - asoc->a_rwnd) >= |
| min_t(__u32, (asoc->base.sk->rcvbuf >> 1), asoc->pmtu))) { |
| SCTP_DEBUG_PRINTK("%s: Sending window update SACK- asoc: %p " |
| "rwnd: %u a_rwnd: %u\n", |
| __FUNCTION__, asoc, asoc->rwnd, asoc->a_rwnd); |
| sack = sctp_make_sack(asoc); |
| if (!sack) |
| return; |
| |
| /* Update the last advertised rwnd value. */ |
| asoc->a_rwnd = asoc->rwnd; |
| |
| asoc->peer.sack_needed = 0; |
| asoc->peer.next_dup_tsn = 0; |
| |
| sctp_outq_tail(&asoc->outqueue, sack); |
| |
| /* Stop the SACK timer. */ |
| timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK]; |
| if (timer_pending(timer) && del_timer(timer)) |
| sctp_association_put(asoc); |
| } |
| } |
| |
| /* Decrease asoc's rwnd by len. */ |
| void sctp_assoc_rwnd_decrease(sctp_association_t *asoc, int len) |
| { |
| SCTP_ASSERT(asoc->rwnd, "rwnd zero", return); |
| SCTP_ASSERT(!asoc->rwnd_over, "rwnd_over not zero", return); |
| if (asoc->rwnd >= len) { |
| asoc->rwnd -= len; |
| } else { |
| asoc->rwnd_over = len - asoc->rwnd; |
| asoc->rwnd = 0; |
| } |
| SCTP_DEBUG_PRINTK("%s: asoc %p rwnd decreased by %d to (%u, %u)\n", |
| __FUNCTION__, asoc, len, asoc->rwnd, asoc->rwnd_over); |
| } |
| |
| /* Build the bind address list for the association based on info from the |
| * local endpoint and the remote peer. |
| */ |
| int sctp_assoc_set_bind_addr_from_ep(sctp_association_t *asoc, int priority) |
| { |
| sctp_scope_t scope; |
| int flags; |
| |
| /* Use scoping rules to determine the subset of addresses from |
| * the endpoint. |
| */ |
| scope = sctp_scope(&asoc->peer.active_path->ipaddr); |
| flags = (PF_INET6 == asoc->base.sk->family) ? SCTP_ADDR6_ALLOWED : 0; |
| if (asoc->peer.ipv4_address) |
| flags |= SCTP_ADDR4_PEERSUPP; |
| if (asoc->peer.ipv6_address) |
| flags |= SCTP_ADDR6_PEERSUPP; |
| |
| return sctp_bind_addr_copy(&asoc->base.bind_addr, |
| &asoc->ep->base.bind_addr, |
| scope, priority, flags); |
| } |
| |
| /* Build the association's bind address list from the cookie. */ |
| int sctp_assoc_set_bind_addr_from_cookie(sctp_association_t *asoc, |
| sctp_cookie_t *cookie, int priority) |
| { |
| int var_size2 = ntohs(cookie->peer_init->chunk_hdr.length); |
| int var_size3 = cookie->raw_addr_list_len; |
| __u8 *raw_addr_list = (__u8 *)cookie + sizeof(sctp_cookie_t) + |
| var_size2; |
| |
| return sctp_raw_to_bind_addrs(&asoc->base.bind_addr, raw_addr_list, |
| var_size3, asoc->ep->base.bind_addr.port, |
| priority); |
| } |