![Xin Long](/assets/img/avatar_default.png)
Like reconf_enable, prsctp_enable should also be removed from asoc, as asoc->peer.prsctp_capable has taken its job. Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1731 lines
49 KiB
C
1731 lines
49 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/* SCTP kernel implementation
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* (C) Copyright IBM Corp. 2001, 2004
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* Copyright (c) 1999-2000 Cisco, Inc.
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* Copyright (c) 1999-2001 Motorola, Inc.
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* Copyright (c) 2001 Intel Corp.
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* Copyright (c) 2001 La Monte H.P. Yarroll
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*
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* This file is part of the SCTP kernel implementation
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*
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* This module provides the abstraction for an SCTP association.
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*
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* Please send any bug reports or fixes you make to the
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* email address(es):
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* lksctp developers <linux-sctp@vger.kernel.org>
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*
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* Written or modified by:
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* La Monte H.P. Yarroll <piggy@acm.org>
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* Karl Knutson <karl@athena.chicago.il.us>
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* Jon Grimm <jgrimm@us.ibm.com>
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* Xingang Guo <xingang.guo@intel.com>
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* Hui Huang <hui.huang@nokia.com>
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* Sridhar Samudrala <sri@us.ibm.com>
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* Daisy Chang <daisyc@us.ibm.com>
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* Ryan Layer <rmlayer@us.ibm.com>
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* Kevin Gao <kevin.gao@intel.com>
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/types.h>
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#include <linux/fcntl.h>
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#include <linux/poll.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/in.h>
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#include <net/ipv6.h>
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#include <net/sctp/sctp.h>
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#include <net/sctp/sm.h>
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/* Forward declarations for internal functions. */
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static void sctp_select_active_and_retran_path(struct sctp_association *asoc);
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static void sctp_assoc_bh_rcv(struct work_struct *work);
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static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc);
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static void sctp_assoc_free_asconf_queue(struct sctp_association *asoc);
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/* 1st Level Abstractions. */
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/* Initialize a new association from provided memory. */
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static struct sctp_association *sctp_association_init(
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struct sctp_association *asoc,
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const struct sctp_endpoint *ep,
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const struct sock *sk,
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enum sctp_scope scope, gfp_t gfp)
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{
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struct net *net = sock_net(sk);
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struct sctp_sock *sp;
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struct sctp_paramhdr *p;
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int i;
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/* Retrieve the SCTP per socket area. */
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sp = sctp_sk((struct sock *)sk);
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/* Discarding const is appropriate here. */
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asoc->ep = (struct sctp_endpoint *)ep;
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asoc->base.sk = (struct sock *)sk;
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sctp_endpoint_hold(asoc->ep);
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sock_hold(asoc->base.sk);
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/* Initialize the common base substructure. */
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asoc->base.type = SCTP_EP_TYPE_ASSOCIATION;
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/* Initialize the object handling fields. */
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refcount_set(&asoc->base.refcnt, 1);
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/* Initialize the bind addr area. */
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sctp_bind_addr_init(&asoc->base.bind_addr, ep->base.bind_addr.port);
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asoc->state = SCTP_STATE_CLOSED;
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asoc->cookie_life = ms_to_ktime(sp->assocparams.sasoc_cookie_life);
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asoc->user_frag = sp->user_frag;
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/* Set the association max_retrans and RTO values from the
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* socket values.
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*/
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asoc->max_retrans = sp->assocparams.sasoc_asocmaxrxt;
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asoc->pf_retrans = sp->pf_retrans;
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asoc->rto_initial = msecs_to_jiffies(sp->rtoinfo.srto_initial);
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asoc->rto_max = msecs_to_jiffies(sp->rtoinfo.srto_max);
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asoc->rto_min = msecs_to_jiffies(sp->rtoinfo.srto_min);
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/* Initialize the association's heartbeat interval based on the
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* sock configured value.
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*/
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asoc->hbinterval = msecs_to_jiffies(sp->hbinterval);
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/* Initialize path max retrans value. */
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asoc->pathmaxrxt = sp->pathmaxrxt;
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asoc->flowlabel = sp->flowlabel;
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asoc->dscp = sp->dscp;
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/* Set association default SACK delay */
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asoc->sackdelay = msecs_to_jiffies(sp->sackdelay);
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asoc->sackfreq = sp->sackfreq;
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/* Set the association default flags controlling
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* Heartbeat, SACK delay, and Path MTU Discovery.
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*/
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asoc->param_flags = sp->param_flags;
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/* Initialize the maximum number of new data packets that can be sent
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* in a burst.
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*/
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asoc->max_burst = sp->max_burst;
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asoc->subscribe = sp->subscribe;
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/* initialize association timers */
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asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] = asoc->rto_initial;
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asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] = asoc->rto_initial;
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asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = asoc->rto_initial;
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/* sctpimpguide Section 2.12.2
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* If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the
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* recommended value of 5 times 'RTO.Max'.
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*/
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asoc->timeouts[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]
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= 5 * asoc->rto_max;
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asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = asoc->sackdelay;
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asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] = sp->autoclose * HZ;
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/* Initializes the timers */
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for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i)
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timer_setup(&asoc->timers[i], sctp_timer_events[i], 0);
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/* Pull default initialization values from the sock options.
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* Note: This assumes that the values have already been
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* validated in the sock.
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*/
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asoc->c.sinit_max_instreams = sp->initmsg.sinit_max_instreams;
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asoc->c.sinit_num_ostreams = sp->initmsg.sinit_num_ostreams;
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asoc->max_init_attempts = sp->initmsg.sinit_max_attempts;
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asoc->max_init_timeo =
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msecs_to_jiffies(sp->initmsg.sinit_max_init_timeo);
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/* Set the local window size for receive.
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* This is also the rcvbuf space per association.
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* RFC 6 - A SCTP receiver MUST be able to receive a minimum of
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* 1500 bytes in one SCTP packet.
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*/
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if ((sk->sk_rcvbuf/2) < SCTP_DEFAULT_MINWINDOW)
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asoc->rwnd = SCTP_DEFAULT_MINWINDOW;
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else
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asoc->rwnd = sk->sk_rcvbuf/2;
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asoc->a_rwnd = asoc->rwnd;
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/* Use my own max window until I learn something better. */
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asoc->peer.rwnd = SCTP_DEFAULT_MAXWINDOW;
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/* Initialize the receive memory counter */
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atomic_set(&asoc->rmem_alloc, 0);
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init_waitqueue_head(&asoc->wait);
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asoc->c.my_vtag = sctp_generate_tag(ep);
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asoc->c.my_port = ep->base.bind_addr.port;
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asoc->c.initial_tsn = sctp_generate_tsn(ep);
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asoc->next_tsn = asoc->c.initial_tsn;
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asoc->ctsn_ack_point = asoc->next_tsn - 1;
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asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
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asoc->highest_sacked = asoc->ctsn_ack_point;
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asoc->last_cwr_tsn = asoc->ctsn_ack_point;
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/* ADDIP Section 4.1 Asconf Chunk Procedures
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*
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* When an endpoint has an ASCONF signaled change to be sent to the
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* remote endpoint it should do the following:
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* ...
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* A2) a serial number should be assigned to the chunk. The serial
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* number SHOULD be a monotonically increasing number. The serial
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* numbers SHOULD be initialized at the start of the
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* association to the same value as the initial TSN.
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*/
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asoc->addip_serial = asoc->c.initial_tsn;
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asoc->strreset_outseq = asoc->c.initial_tsn;
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INIT_LIST_HEAD(&asoc->addip_chunk_list);
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INIT_LIST_HEAD(&asoc->asconf_ack_list);
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/* Make an empty list of remote transport addresses. */
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INIT_LIST_HEAD(&asoc->peer.transport_addr_list);
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/* RFC 2960 5.1 Normal Establishment of an Association
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*
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* After the reception of the first data chunk in an
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* association the endpoint must immediately respond with a
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* sack to acknowledge the data chunk. Subsequent
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* acknowledgements should be done as described in Section
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* 6.2.
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*
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* [We implement this by telling a new association that it
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* already received one packet.]
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*/
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asoc->peer.sack_needed = 1;
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asoc->peer.sack_generation = 1;
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/* Assume that the peer will tell us if he recognizes ASCONF
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* as part of INIT exchange.
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* The sctp_addip_noauth option is there for backward compatibility
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* and will revert old behavior.
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*/
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if (net->sctp.addip_noauth)
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asoc->peer.asconf_capable = 1;
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/* Create an input queue. */
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sctp_inq_init(&asoc->base.inqueue);
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sctp_inq_set_th_handler(&asoc->base.inqueue, sctp_assoc_bh_rcv);
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/* Create an output queue. */
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sctp_outq_init(asoc, &asoc->outqueue);
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if (!sctp_ulpq_init(&asoc->ulpq, asoc))
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goto fail_init;
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if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams,
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0, gfp))
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goto fail_init;
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/* Initialize default path MTU. */
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asoc->pathmtu = sp->pathmtu;
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sctp_assoc_update_frag_point(asoc);
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/* Assume that peer would support both address types unless we are
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* told otherwise.
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*/
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asoc->peer.ipv4_address = 1;
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if (asoc->base.sk->sk_family == PF_INET6)
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asoc->peer.ipv6_address = 1;
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INIT_LIST_HEAD(&asoc->asocs);
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asoc->default_stream = sp->default_stream;
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asoc->default_ppid = sp->default_ppid;
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asoc->default_flags = sp->default_flags;
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asoc->default_context = sp->default_context;
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asoc->default_timetolive = sp->default_timetolive;
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asoc->default_rcv_context = sp->default_rcv_context;
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/* AUTH related initializations */
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INIT_LIST_HEAD(&asoc->endpoint_shared_keys);
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if (sctp_auth_asoc_copy_shkeys(ep, asoc, gfp))
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goto stream_free;
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asoc->active_key_id = ep->active_key_id;
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asoc->strreset_enable = ep->strreset_enable;
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/* Save the hmacs and chunks list into this association */
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if (ep->auth_hmacs_list)
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memcpy(asoc->c.auth_hmacs, ep->auth_hmacs_list,
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ntohs(ep->auth_hmacs_list->param_hdr.length));
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if (ep->auth_chunk_list)
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memcpy(asoc->c.auth_chunks, ep->auth_chunk_list,
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ntohs(ep->auth_chunk_list->param_hdr.length));
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/* Get the AUTH random number for this association */
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p = (struct sctp_paramhdr *)asoc->c.auth_random;
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p->type = SCTP_PARAM_RANDOM;
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p->length = htons(sizeof(*p) + SCTP_AUTH_RANDOM_LENGTH);
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get_random_bytes(p+1, SCTP_AUTH_RANDOM_LENGTH);
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return asoc;
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stream_free:
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sctp_stream_free(&asoc->stream);
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fail_init:
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sock_put(asoc->base.sk);
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sctp_endpoint_put(asoc->ep);
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return NULL;
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}
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/* Allocate and initialize a new association */
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struct sctp_association *sctp_association_new(const struct sctp_endpoint *ep,
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const struct sock *sk,
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enum sctp_scope scope, gfp_t gfp)
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{
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struct sctp_association *asoc;
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asoc = kzalloc(sizeof(*asoc), gfp);
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if (!asoc)
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goto fail;
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if (!sctp_association_init(asoc, ep, sk, scope, gfp))
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goto fail_init;
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SCTP_DBG_OBJCNT_INC(assoc);
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pr_debug("Created asoc %p\n", asoc);
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return asoc;
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fail_init:
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kfree(asoc);
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fail:
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return NULL;
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}
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/* Free this association if possible. There may still be users, so
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* the actual deallocation may be delayed.
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*/
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void sctp_association_free(struct sctp_association *asoc)
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{
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struct sock *sk = asoc->base.sk;
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struct sctp_transport *transport;
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struct list_head *pos, *temp;
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int i;
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/* Only real associations count against the endpoint, so
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* don't bother for if this is a temporary association.
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*/
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if (!list_empty(&asoc->asocs)) {
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list_del(&asoc->asocs);
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/* Decrement the backlog value for a TCP-style listening
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* socket.
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*/
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if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
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sk->sk_ack_backlog--;
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}
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/* Mark as dead, so other users can know this structure is
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* going away.
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*/
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asoc->base.dead = true;
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/* Dispose of any data lying around in the outqueue. */
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sctp_outq_free(&asoc->outqueue);
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/* Dispose of any pending messages for the upper layer. */
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sctp_ulpq_free(&asoc->ulpq);
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/* Dispose of any pending chunks on the inqueue. */
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sctp_inq_free(&asoc->base.inqueue);
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sctp_tsnmap_free(&asoc->peer.tsn_map);
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/* Free stream information. */
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sctp_stream_free(&asoc->stream);
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if (asoc->strreset_chunk)
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sctp_chunk_free(asoc->strreset_chunk);
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/* Clean up the bound address list. */
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sctp_bind_addr_free(&asoc->base.bind_addr);
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/* Do we need to go through all of our timers and
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* delete them? To be safe we will try to delete all, but we
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* should be able to go through and make a guess based
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* on our state.
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*/
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for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) {
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if (del_timer(&asoc->timers[i]))
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sctp_association_put(asoc);
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}
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/* Free peer's cached cookie. */
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kfree(asoc->peer.cookie);
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kfree(asoc->peer.peer_random);
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kfree(asoc->peer.peer_chunks);
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kfree(asoc->peer.peer_hmacs);
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/* Release the transport structures. */
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list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
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transport = list_entry(pos, struct sctp_transport, transports);
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list_del_rcu(pos);
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sctp_unhash_transport(transport);
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sctp_transport_free(transport);
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}
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asoc->peer.transport_count = 0;
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sctp_asconf_queue_teardown(asoc);
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/* Free pending address space being deleted */
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kfree(asoc->asconf_addr_del_pending);
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/* AUTH - Free the endpoint shared keys */
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sctp_auth_destroy_keys(&asoc->endpoint_shared_keys);
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/* AUTH - Free the association shared key */
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sctp_auth_key_put(asoc->asoc_shared_key);
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sctp_association_put(asoc);
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}
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/* Cleanup and free up an association. */
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static void sctp_association_destroy(struct sctp_association *asoc)
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{
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if (unlikely(!asoc->base.dead)) {
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WARN(1, "Attempt to destroy undead association %p!\n", asoc);
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return;
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}
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sctp_endpoint_put(asoc->ep);
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sock_put(asoc->base.sk);
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if (asoc->assoc_id != 0) {
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spin_lock_bh(&sctp_assocs_id_lock);
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idr_remove(&sctp_assocs_id, asoc->assoc_id);
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spin_unlock_bh(&sctp_assocs_id_lock);
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}
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WARN_ON(atomic_read(&asoc->rmem_alloc));
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kfree_rcu(asoc, rcu);
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SCTP_DBG_OBJCNT_DEC(assoc);
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}
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/* Change the primary destination address for the peer. */
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void sctp_assoc_set_primary(struct sctp_association *asoc,
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struct sctp_transport *transport)
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{
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int changeover = 0;
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/* it's a changeover only if we already have a primary path
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* that we are changing
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*/
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if (asoc->peer.primary_path != NULL &&
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asoc->peer.primary_path != transport)
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changeover = 1 ;
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asoc->peer.primary_path = transport;
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/* Set a default msg_name for events. */
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memcpy(&asoc->peer.primary_addr, &transport->ipaddr,
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sizeof(union sctp_addr));
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/* If the primary path is changing, assume that the
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* user wants to use this new path.
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*/
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if ((transport->state == SCTP_ACTIVE) ||
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(transport->state == SCTP_UNKNOWN))
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asoc->peer.active_path = transport;
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|
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/*
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* SFR-CACC algorithm:
|
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* Upon the receipt of a request to change the primary
|
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* destination address, on the data structure for the new
|
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* primary destination, the sender MUST do the following:
|
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*
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* 1) If CHANGEOVER_ACTIVE is set, then there was a switch
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* to this destination address earlier. The sender MUST set
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* CYCLING_CHANGEOVER to indicate that this switch is a
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* double switch to the same destination address.
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*
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* Really, only bother is we have data queued or outstanding on
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* the association.
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*/
|
|
if (!asoc->outqueue.outstanding_bytes && !asoc->outqueue.out_qlen)
|
|
return;
|
|
|
|
if (transport->cacc.changeover_active)
|
|
transport->cacc.cycling_changeover = changeover;
|
|
|
|
/* 2) The sender MUST set CHANGEOVER_ACTIVE to indicate that
|
|
* a changeover has occurred.
|
|
*/
|
|
transport->cacc.changeover_active = changeover;
|
|
|
|
/* 3) The sender MUST store the next TSN to be sent in
|
|
* next_tsn_at_change.
|
|
*/
|
|
transport->cacc.next_tsn_at_change = asoc->next_tsn;
|
|
}
|
|
|
|
/* Remove a transport from an association. */
|
|
void sctp_assoc_rm_peer(struct sctp_association *asoc,
|
|
struct sctp_transport *peer)
|
|
{
|
|
struct sctp_transport *transport;
|
|
struct list_head *pos;
|
|
struct sctp_chunk *ch;
|
|
|
|
pr_debug("%s: association:%p addr:%pISpc\n",
|
|
__func__, asoc, &peer->ipaddr.sa);
|
|
|
|
/* If we are to remove the current retran_path, update it
|
|
* to the next peer before removing this peer from the list.
|
|
*/
|
|
if (asoc->peer.retran_path == peer)
|
|
sctp_assoc_update_retran_path(asoc);
|
|
|
|
/* Remove this peer from the list. */
|
|
list_del_rcu(&peer->transports);
|
|
/* Remove this peer from the transport hashtable */
|
|
sctp_unhash_transport(peer);
|
|
|
|
/* Get the first transport of asoc. */
|
|
pos = asoc->peer.transport_addr_list.next;
|
|
transport = list_entry(pos, struct sctp_transport, transports);
|
|
|
|
/* Update any entries that match the peer to be deleted. */
|
|
if (asoc->peer.primary_path == peer)
|
|
sctp_assoc_set_primary(asoc, transport);
|
|
if (asoc->peer.active_path == peer)
|
|
asoc->peer.active_path = transport;
|
|
if (asoc->peer.retran_path == peer)
|
|
asoc->peer.retran_path = transport;
|
|
if (asoc->peer.last_data_from == peer)
|
|
asoc->peer.last_data_from = transport;
|
|
|
|
if (asoc->strreset_chunk &&
|
|
asoc->strreset_chunk->transport == peer) {
|
|
asoc->strreset_chunk->transport = transport;
|
|
sctp_transport_reset_reconf_timer(transport);
|
|
}
|
|
|
|
/* If we remove the transport an INIT was last sent to, set it to
|
|
* NULL. Combined with the update of the retran path above, this
|
|
* will cause the next INIT to be sent to the next available
|
|
* transport, maintaining the cycle.
|
|
*/
|
|
if (asoc->init_last_sent_to == peer)
|
|
asoc->init_last_sent_to = NULL;
|
|
|
|
/* If we remove the transport an SHUTDOWN was last sent to, set it
|
|
* to NULL. Combined with the update of the retran path above, this
|
|
* will cause the next SHUTDOWN to be sent to the next available
|
|
* transport, maintaining the cycle.
|
|
*/
|
|
if (asoc->shutdown_last_sent_to == peer)
|
|
asoc->shutdown_last_sent_to = NULL;
|
|
|
|
/* If we remove the transport an ASCONF was last sent to, set it to
|
|
* NULL.
|
|
*/
|
|
if (asoc->addip_last_asconf &&
|
|
asoc->addip_last_asconf->transport == peer)
|
|
asoc->addip_last_asconf->transport = NULL;
|
|
|
|
/* If we have something on the transmitted list, we have to
|
|
* save it off. The best place is the active path.
|
|
*/
|
|
if (!list_empty(&peer->transmitted)) {
|
|
struct sctp_transport *active = asoc->peer.active_path;
|
|
|
|
/* Reset the transport of each chunk on this list */
|
|
list_for_each_entry(ch, &peer->transmitted,
|
|
transmitted_list) {
|
|
ch->transport = NULL;
|
|
ch->rtt_in_progress = 0;
|
|
}
|
|
|
|
list_splice_tail_init(&peer->transmitted,
|
|
&active->transmitted);
|
|
|
|
/* Start a T3 timer here in case it wasn't running so
|
|
* that these migrated packets have a chance to get
|
|
* retransmitted.
|
|
*/
|
|
if (!timer_pending(&active->T3_rtx_timer))
|
|
if (!mod_timer(&active->T3_rtx_timer,
|
|
jiffies + active->rto))
|
|
sctp_transport_hold(active);
|
|
}
|
|
|
|
list_for_each_entry(ch, &asoc->outqueue.out_chunk_list, list)
|
|
if (ch->transport == peer)
|
|
ch->transport = NULL;
|
|
|
|
asoc->peer.transport_count--;
|
|
|
|
sctp_transport_free(peer);
|
|
}
|
|
|
|
/* Add a transport address to an association. */
|
|
struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
|
|
const union sctp_addr *addr,
|
|
const gfp_t gfp,
|
|
const int peer_state)
|
|
{
|
|
struct net *net = sock_net(asoc->base.sk);
|
|
struct sctp_transport *peer;
|
|
struct sctp_sock *sp;
|
|
unsigned short port;
|
|
|
|
sp = sctp_sk(asoc->base.sk);
|
|
|
|
/* AF_INET and AF_INET6 share common port field. */
|
|
port = ntohs(addr->v4.sin_port);
|
|
|
|
pr_debug("%s: association:%p addr:%pISpc state:%d\n", __func__,
|
|
asoc, &addr->sa, peer_state);
|
|
|
|
/* 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) {
|
|
/* An UNKNOWN state is only set on transports added by
|
|
* user in sctp_connectx() call. Such transports should be
|
|
* considered CONFIRMED per RFC 4960, Section 5.4.
|
|
*/
|
|
if (peer->state == SCTP_UNKNOWN) {
|
|
peer->state = SCTP_ACTIVE;
|
|
}
|
|
return peer;
|
|
}
|
|
|
|
peer = sctp_transport_new(net, addr, gfp);
|
|
if (!peer)
|
|
return NULL;
|
|
|
|
sctp_transport_set_owner(peer, asoc);
|
|
|
|
/* Initialize the peer's heartbeat interval based on the
|
|
* association configured value.
|
|
*/
|
|
peer->hbinterval = asoc->hbinterval;
|
|
|
|
/* Set the path max_retrans. */
|
|
peer->pathmaxrxt = asoc->pathmaxrxt;
|
|
|
|
/* And the partial failure retrans threshold */
|
|
peer->pf_retrans = asoc->pf_retrans;
|
|
|
|
/* Initialize the peer's SACK delay timeout based on the
|
|
* association configured value.
|
|
*/
|
|
peer->sackdelay = asoc->sackdelay;
|
|
peer->sackfreq = asoc->sackfreq;
|
|
|
|
if (addr->sa.sa_family == AF_INET6) {
|
|
__be32 info = addr->v6.sin6_flowinfo;
|
|
|
|
if (info) {
|
|
peer->flowlabel = ntohl(info & IPV6_FLOWLABEL_MASK);
|
|
peer->flowlabel |= SCTP_FLOWLABEL_SET_MASK;
|
|
} else {
|
|
peer->flowlabel = asoc->flowlabel;
|
|
}
|
|
}
|
|
peer->dscp = asoc->dscp;
|
|
|
|
/* Enable/disable heartbeat, SACK delay, and path MTU discovery
|
|
* based on association setting.
|
|
*/
|
|
peer->param_flags = asoc->param_flags;
|
|
|
|
/* Initialize the pmtu of the transport. */
|
|
sctp_transport_route(peer, NULL, sp);
|
|
|
|
/* 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.
|
|
*/
|
|
sctp_assoc_set_pmtu(asoc, asoc->pathmtu ?
|
|
min_t(int, peer->pathmtu, asoc->pathmtu) :
|
|
peer->pathmtu);
|
|
|
|
peer->pmtu_pending = 0;
|
|
|
|
/* The asoc->peer.port might not be meaningful yet, but
|
|
* initialize the packet structure anyway.
|
|
*/
|
|
sctp_packet_init(&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 set to
|
|
* min(4*MTU, max(2*MTU, 4380 bytes))
|
|
*
|
|
* o The initial value of ssthresh MAY be arbitrarily high
|
|
* (for example, implementations MAY use the size of the
|
|
* receiver advertised window).
|
|
*/
|
|
peer->cwnd = min(4*asoc->pathmtu, max_t(__u32, 2*asoc->pathmtu, 4380));
|
|
|
|
/* 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->burst_limited = 0;
|
|
|
|
/* Set the transport's RTO.initial value */
|
|
peer->rto = asoc->rto_initial;
|
|
sctp_max_rto(asoc, peer);
|
|
|
|
/* Set the peer's active state. */
|
|
peer->state = peer_state;
|
|
|
|
/* Add this peer into the transport hashtable */
|
|
if (sctp_hash_transport(peer)) {
|
|
sctp_transport_free(peer);
|
|
return NULL;
|
|
}
|
|
|
|
/* Attach the remote transport to our asoc. */
|
|
list_add_tail_rcu(&peer->transports, &asoc->peer.transport_addr_list);
|
|
asoc->peer.transport_count++;
|
|
|
|
/* If we do not yet have a primary path, set one. */
|
|
if (!asoc->peer.primary_path) {
|
|
sctp_assoc_set_primary(asoc, peer);
|
|
asoc->peer.retran_path = peer;
|
|
}
|
|
|
|
if (asoc->peer.active_path == asoc->peer.retran_path &&
|
|
peer->state != SCTP_UNCONFIRMED) {
|
|
asoc->peer.retran_path = peer;
|
|
}
|
|
|
|
return peer;
|
|
}
|
|
|
|
/* Delete a transport address from an association. */
|
|
void sctp_assoc_del_peer(struct sctp_association *asoc,
|
|
const union sctp_addr *addr)
|
|
{
|
|
struct list_head *pos;
|
|
struct list_head *temp;
|
|
struct sctp_transport *transport;
|
|
|
|
list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
|
|
transport = list_entry(pos, struct sctp_transport, transports);
|
|
if (sctp_cmp_addr_exact(addr, &transport->ipaddr)) {
|
|
/* Do book keeping for removing the peer and free it. */
|
|
sctp_assoc_rm_peer(asoc, transport);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Lookup a transport by address. */
|
|
struct sctp_transport *sctp_assoc_lookup_paddr(
|
|
const struct sctp_association *asoc,
|
|
const union sctp_addr *address)
|
|
{
|
|
struct sctp_transport *t;
|
|
|
|
/* Cycle through all transports searching for a peer address. */
|
|
|
|
list_for_each_entry(t, &asoc->peer.transport_addr_list,
|
|
transports) {
|
|
if (sctp_cmp_addr_exact(address, &t->ipaddr))
|
|
return t;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/* Remove all transports except a give one */
|
|
void sctp_assoc_del_nonprimary_peers(struct sctp_association *asoc,
|
|
struct sctp_transport *primary)
|
|
{
|
|
struct sctp_transport *temp;
|
|
struct sctp_transport *t;
|
|
|
|
list_for_each_entry_safe(t, temp, &asoc->peer.transport_addr_list,
|
|
transports) {
|
|
/* if the current transport is not the primary one, delete it */
|
|
if (t != primary)
|
|
sctp_assoc_rm_peer(asoc, t);
|
|
}
|
|
}
|
|
|
|
/* 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(struct sctp_association *asoc,
|
|
struct sctp_transport *transport,
|
|
enum sctp_transport_cmd command,
|
|
sctp_sn_error_t error)
|
|
{
|
|
struct sctp_ulpevent *event;
|
|
struct sockaddr_storage addr;
|
|
int spc_state = 0;
|
|
bool ulp_notify = true;
|
|
|
|
/* Record the transition on the transport. */
|
|
switch (command) {
|
|
case SCTP_TRANSPORT_UP:
|
|
/* If we are moving from UNCONFIRMED state due
|
|
* to heartbeat success, report the SCTP_ADDR_CONFIRMED
|
|
* state to the user, otherwise report SCTP_ADDR_AVAILABLE.
|
|
*/
|
|
if (SCTP_UNCONFIRMED == transport->state &&
|
|
SCTP_HEARTBEAT_SUCCESS == error)
|
|
spc_state = SCTP_ADDR_CONFIRMED;
|
|
else
|
|
spc_state = SCTP_ADDR_AVAILABLE;
|
|
/* Don't inform ULP about transition from PF to
|
|
* active state and set cwnd to 1 MTU, see SCTP
|
|
* Quick failover draft section 5.1, point 5
|
|
*/
|
|
if (transport->state == SCTP_PF) {
|
|
ulp_notify = false;
|
|
transport->cwnd = asoc->pathmtu;
|
|
}
|
|
transport->state = SCTP_ACTIVE;
|
|
break;
|
|
|
|
case SCTP_TRANSPORT_DOWN:
|
|
/* If the transport was never confirmed, do not transition it
|
|
* to inactive state. Also, release the cached route since
|
|
* there may be a better route next time.
|
|
*/
|
|
if (transport->state != SCTP_UNCONFIRMED)
|
|
transport->state = SCTP_INACTIVE;
|
|
else {
|
|
sctp_transport_dst_release(transport);
|
|
ulp_notify = false;
|
|
}
|
|
|
|
spc_state = SCTP_ADDR_UNREACHABLE;
|
|
break;
|
|
|
|
case SCTP_TRANSPORT_PF:
|
|
transport->state = SCTP_PF;
|
|
ulp_notify = false;
|
|
break;
|
|
|
|
default:
|
|
return;
|
|
}
|
|
|
|
/* Generate and send a SCTP_PEER_ADDR_CHANGE notification
|
|
* to the user.
|
|
*/
|
|
if (ulp_notify) {
|
|
memset(&addr, 0, sizeof(struct sockaddr_storage));
|
|
memcpy(&addr, &transport->ipaddr,
|
|
transport->af_specific->sockaddr_len);
|
|
|
|
event = sctp_ulpevent_make_peer_addr_change(asoc, &addr,
|
|
0, spc_state, error, GFP_ATOMIC);
|
|
if (event)
|
|
asoc->stream.si->enqueue_event(&asoc->ulpq, event);
|
|
}
|
|
|
|
/* Select new active and retran paths. */
|
|
sctp_select_active_and_retran_path(asoc);
|
|
}
|
|
|
|
/* Hold a reference to an association. */
|
|
void sctp_association_hold(struct sctp_association *asoc)
|
|
{
|
|
refcount_inc(&asoc->base.refcnt);
|
|
}
|
|
|
|
/* Release a reference to an association and cleanup
|
|
* if there are no more references.
|
|
*/
|
|
void sctp_association_put(struct sctp_association *asoc)
|
|
{
|
|
if (refcount_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(struct sctp_association *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;
|
|
}
|
|
|
|
/* Compare two addresses to see if they match. Wildcard addresses
|
|
* only match themselves.
|
|
*/
|
|
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 (unlikely(!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. FIXME:
|
|
* No we don't, but we could/should.
|
|
*/
|
|
struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc)
|
|
{
|
|
if (!asoc->need_ecne)
|
|
return NULL;
|
|
|
|
/* Send ECNE if needed.
|
|
* Not being able to allocate a chunk here is not deadly.
|
|
*/
|
|
return sctp_make_ecne(asoc, asoc->last_ecne_tsn);
|
|
}
|
|
|
|
/*
|
|
* Find which transport this TSN was sent on.
|
|
*/
|
|
struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *asoc,
|
|
__u32 tsn)
|
|
{
|
|
struct sctp_transport *active;
|
|
struct sctp_transport *match;
|
|
struct sctp_transport *transport;
|
|
struct sctp_chunk *chunk;
|
|
__be32 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(chunk, &active->transmitted,
|
|
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_entry(transport, &asoc->peer.transport_addr_list,
|
|
transports) {
|
|
|
|
if (transport == active)
|
|
continue;
|
|
list_for_each_entry(chunk, &transport->transmitted,
|
|
transmitted_list) {
|
|
if (key == chunk->subh.data_hdr->tsn) {
|
|
match = transport;
|
|
goto out;
|
|
}
|
|
}
|
|
}
|
|
out:
|
|
return match;
|
|
}
|
|
|
|
/* Do delayed input processing. This is scheduled by sctp_rcv(). */
|
|
static void sctp_assoc_bh_rcv(struct work_struct *work)
|
|
{
|
|
struct sctp_association *asoc =
|
|
container_of(work, struct sctp_association,
|
|
base.inqueue.immediate);
|
|
struct net *net = sock_net(asoc->base.sk);
|
|
union sctp_subtype subtype;
|
|
struct sctp_endpoint *ep;
|
|
struct sctp_chunk *chunk;
|
|
struct sctp_inq *inqueue;
|
|
int first_time = 1; /* is this the first time through the loop */
|
|
int error = 0;
|
|
int state;
|
|
|
|
/* The association should be held so we should be safe. */
|
|
ep = asoc->ep;
|
|
|
|
inqueue = &asoc->base.inqueue;
|
|
sctp_association_hold(asoc);
|
|
while (NULL != (chunk = sctp_inq_pop(inqueue))) {
|
|
state = asoc->state;
|
|
subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
|
|
|
|
/* If the first chunk in the packet is AUTH, do special
|
|
* processing specified in Section 6.3 of SCTP-AUTH spec
|
|
*/
|
|
if (first_time && subtype.chunk == SCTP_CID_AUTH) {
|
|
struct sctp_chunkhdr *next_hdr;
|
|
|
|
next_hdr = sctp_inq_peek(inqueue);
|
|
if (!next_hdr)
|
|
goto normal;
|
|
|
|
/* If the next chunk is COOKIE-ECHO, skip the AUTH
|
|
* chunk while saving a pointer to it so we can do
|
|
* Authentication later (during cookie-echo
|
|
* processing).
|
|
*/
|
|
if (next_hdr->type == SCTP_CID_COOKIE_ECHO) {
|
|
chunk->auth_chunk = skb_clone(chunk->skb,
|
|
GFP_ATOMIC);
|
|
chunk->auth = 1;
|
|
continue;
|
|
}
|
|
}
|
|
|
|
normal:
|
|
/* SCTP-AUTH, Section 6.3:
|
|
* The receiver has a list of chunk types which it expects
|
|
* to be received only after an AUTH-chunk. This list has
|
|
* been sent to the peer during the association setup. It
|
|
* MUST silently discard these chunks if they are not placed
|
|
* after an AUTH chunk in the packet.
|
|
*/
|
|
if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth)
|
|
continue;
|
|
|
|
/* 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;
|
|
else {
|
|
SCTP_INC_STATS(net, SCTP_MIB_INCTRLCHUNKS);
|
|
asoc->stats.ictrlchunks++;
|
|
if (chunk->chunk_hdr->type == SCTP_CID_SACK)
|
|
asoc->stats.isacks++;
|
|
}
|
|
|
|
if (chunk->transport)
|
|
chunk->transport->last_time_heard = ktime_get();
|
|
|
|
/* Run through the state machine. */
|
|
error = sctp_do_sm(net, SCTP_EVENT_T_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 (asoc->base.dead)
|
|
break;
|
|
|
|
/* If there is an error on chunk, discard this packet. */
|
|
if (error && chunk)
|
|
chunk->pdiscard = 1;
|
|
|
|
if (first_time)
|
|
first_time = 0;
|
|
}
|
|
sctp_association_put(asoc);
|
|
}
|
|
|
|
/* This routine moves an association from its old sk to a new sk. */
|
|
void sctp_assoc_migrate(struct sctp_association *assoc, struct sock *newsk)
|
|
{
|
|
struct sctp_sock *newsp = sctp_sk(newsk);
|
|
struct sock *oldsk = assoc->base.sk;
|
|
|
|
/* Delete the association from the old endpoint's list of
|
|
* associations.
|
|
*/
|
|
list_del_init(&assoc->asocs);
|
|
|
|
/* Decrement the backlog value for a TCP-style socket. */
|
|
if (sctp_style(oldsk, TCP))
|
|
oldsk->sk_ack_backlog--;
|
|
|
|
/* 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). */
|
|
int sctp_assoc_update(struct sctp_association *asoc,
|
|
struct sctp_association *new)
|
|
{
|
|
struct sctp_transport *trans;
|
|
struct list_head *pos, *temp;
|
|
|
|
/* Copy in new parameters of peer. */
|
|
asoc->c = new->c;
|
|
asoc->peer.rwnd = new->peer.rwnd;
|
|
asoc->peer.sack_needed = new->peer.sack_needed;
|
|
asoc->peer.auth_capable = new->peer.auth_capable;
|
|
asoc->peer.i = new->peer.i;
|
|
|
|
if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
|
|
asoc->peer.i.initial_tsn, GFP_ATOMIC))
|
|
return -ENOMEM;
|
|
|
|
/* Remove any peer addresses not present in the new association. */
|
|
list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
|
|
trans = list_entry(pos, struct sctp_transport, transports);
|
|
if (!sctp_assoc_lookup_paddr(new, &trans->ipaddr)) {
|
|
sctp_assoc_rm_peer(asoc, trans);
|
|
continue;
|
|
}
|
|
|
|
if (asoc->state >= SCTP_STATE_ESTABLISHED)
|
|
sctp_transport_reset(trans);
|
|
}
|
|
|
|
/* 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 (asoc->state >= SCTP_STATE_ESTABLISHED) {
|
|
asoc->next_tsn = new->next_tsn;
|
|
asoc->ctsn_ack_point = new->ctsn_ack_point;
|
|
asoc->adv_peer_ack_point = new->adv_peer_ack_point;
|
|
|
|
/* Reinitialize SSN for both local streams
|
|
* and peer's streams.
|
|
*/
|
|
sctp_stream_clear(&asoc->stream);
|
|
|
|
/* Flush the ULP reassembly and ordered queue.
|
|
* Any data there will now be stale and will
|
|
* cause problems.
|
|
*/
|
|
sctp_ulpq_flush(&asoc->ulpq);
|
|
|
|
/* reset the overall association error count so
|
|
* that the restarted association doesn't get torn
|
|
* down on the next retransmission timer.
|
|
*/
|
|
asoc->overall_error_count = 0;
|
|
|
|
} else {
|
|
/* Add any peer addresses from the new association. */
|
|
list_for_each_entry(trans, &new->peer.transport_addr_list,
|
|
transports)
|
|
if (!sctp_assoc_lookup_paddr(asoc, &trans->ipaddr) &&
|
|
!sctp_assoc_add_peer(asoc, &trans->ipaddr,
|
|
GFP_ATOMIC, trans->state))
|
|
return -ENOMEM;
|
|
|
|
asoc->ctsn_ack_point = asoc->next_tsn - 1;
|
|
asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
|
|
|
|
if (sctp_state(asoc, COOKIE_WAIT))
|
|
sctp_stream_update(&asoc->stream, &new->stream);
|
|
|
|
/* get a new assoc id if we don't have one yet. */
|
|
if (sctp_assoc_set_id(asoc, GFP_ATOMIC))
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/* SCTP-AUTH: Save the peer parameters from the new associations
|
|
* and also move the association shared keys over
|
|
*/
|
|
kfree(asoc->peer.peer_random);
|
|
asoc->peer.peer_random = new->peer.peer_random;
|
|
new->peer.peer_random = NULL;
|
|
|
|
kfree(asoc->peer.peer_chunks);
|
|
asoc->peer.peer_chunks = new->peer.peer_chunks;
|
|
new->peer.peer_chunks = NULL;
|
|
|
|
kfree(asoc->peer.peer_hmacs);
|
|
asoc->peer.peer_hmacs = new->peer.peer_hmacs;
|
|
new->peer.peer_hmacs = NULL;
|
|
|
|
return sctp_auth_asoc_init_active_key(asoc, GFP_ATOMIC);
|
|
}
|
|
|
|
/* Update the retran path for sending a retransmitted packet.
|
|
* See also RFC4960, 6.4. Multi-Homed SCTP Endpoints:
|
|
*
|
|
* When there is outbound data to send and the primary path
|
|
* becomes inactive (e.g., due to failures), or where the
|
|
* SCTP user explicitly requests to send data to an
|
|
* inactive destination transport address, before reporting
|
|
* an error to its ULP, the SCTP endpoint should try to send
|
|
* the data to an alternate active destination transport
|
|
* address if one exists.
|
|
*
|
|
* When retransmitting data that timed out, if the endpoint
|
|
* is multihomed, it should consider each source-destination
|
|
* address pair in its retransmission selection policy.
|
|
* When retransmitting timed-out data, the endpoint should
|
|
* attempt to pick the most divergent source-destination
|
|
* pair from the original source-destination pair to which
|
|
* the packet was transmitted.
|
|
*
|
|
* Note: Rules for picking the most divergent source-destination
|
|
* pair are an implementation decision and are not specified
|
|
* within this document.
|
|
*
|
|
* Our basic strategy is to round-robin transports in priorities
|
|
* according to sctp_trans_score() e.g., if no such
|
|
* transport with state SCTP_ACTIVE exists, round-robin through
|
|
* SCTP_UNKNOWN, etc. You get the picture.
|
|
*/
|
|
static u8 sctp_trans_score(const struct sctp_transport *trans)
|
|
{
|
|
switch (trans->state) {
|
|
case SCTP_ACTIVE:
|
|
return 3; /* best case */
|
|
case SCTP_UNKNOWN:
|
|
return 2;
|
|
case SCTP_PF:
|
|
return 1;
|
|
default: /* case SCTP_INACTIVE */
|
|
return 0; /* worst case */
|
|
}
|
|
}
|
|
|
|
static struct sctp_transport *sctp_trans_elect_tie(struct sctp_transport *trans1,
|
|
struct sctp_transport *trans2)
|
|
{
|
|
if (trans1->error_count > trans2->error_count) {
|
|
return trans2;
|
|
} else if (trans1->error_count == trans2->error_count &&
|
|
ktime_after(trans2->last_time_heard,
|
|
trans1->last_time_heard)) {
|
|
return trans2;
|
|
} else {
|
|
return trans1;
|
|
}
|
|
}
|
|
|
|
static struct sctp_transport *sctp_trans_elect_best(struct sctp_transport *curr,
|
|
struct sctp_transport *best)
|
|
{
|
|
u8 score_curr, score_best;
|
|
|
|
if (best == NULL || curr == best)
|
|
return curr;
|
|
|
|
score_curr = sctp_trans_score(curr);
|
|
score_best = sctp_trans_score(best);
|
|
|
|
/* First, try a score-based selection if both transport states
|
|
* differ. If we're in a tie, lets try to make a more clever
|
|
* decision here based on error counts and last time heard.
|
|
*/
|
|
if (score_curr > score_best)
|
|
return curr;
|
|
else if (score_curr == score_best)
|
|
return sctp_trans_elect_tie(best, curr);
|
|
else
|
|
return best;
|
|
}
|
|
|
|
void sctp_assoc_update_retran_path(struct sctp_association *asoc)
|
|
{
|
|
struct sctp_transport *trans = asoc->peer.retran_path;
|
|
struct sctp_transport *trans_next = NULL;
|
|
|
|
/* We're done as we only have the one and only path. */
|
|
if (asoc->peer.transport_count == 1)
|
|
return;
|
|
/* If active_path and retran_path are the same and active,
|
|
* then this is the only active path. Use it.
|
|
*/
|
|
if (asoc->peer.active_path == asoc->peer.retran_path &&
|
|
asoc->peer.active_path->state == SCTP_ACTIVE)
|
|
return;
|
|
|
|
/* Iterate from retran_path's successor back to retran_path. */
|
|
for (trans = list_next_entry(trans, transports); 1;
|
|
trans = list_next_entry(trans, transports)) {
|
|
/* Manually skip the head element. */
|
|
if (&trans->transports == &asoc->peer.transport_addr_list)
|
|
continue;
|
|
if (trans->state == SCTP_UNCONFIRMED)
|
|
continue;
|
|
trans_next = sctp_trans_elect_best(trans, trans_next);
|
|
/* Active is good enough for immediate return. */
|
|
if (trans_next->state == SCTP_ACTIVE)
|
|
break;
|
|
/* We've reached the end, time to update path. */
|
|
if (trans == asoc->peer.retran_path)
|
|
break;
|
|
}
|
|
|
|
asoc->peer.retran_path = trans_next;
|
|
|
|
pr_debug("%s: association:%p updated new path to addr:%pISpc\n",
|
|
__func__, asoc, &asoc->peer.retran_path->ipaddr.sa);
|
|
}
|
|
|
|
static void sctp_select_active_and_retran_path(struct sctp_association *asoc)
|
|
{
|
|
struct sctp_transport *trans, *trans_pri = NULL, *trans_sec = NULL;
|
|
struct sctp_transport *trans_pf = NULL;
|
|
|
|
/* Look for the two most recently used active transports. */
|
|
list_for_each_entry(trans, &asoc->peer.transport_addr_list,
|
|
transports) {
|
|
/* Skip uninteresting transports. */
|
|
if (trans->state == SCTP_INACTIVE ||
|
|
trans->state == SCTP_UNCONFIRMED)
|
|
continue;
|
|
/* Keep track of the best PF transport from our
|
|
* list in case we don't find an active one.
|
|
*/
|
|
if (trans->state == SCTP_PF) {
|
|
trans_pf = sctp_trans_elect_best(trans, trans_pf);
|
|
continue;
|
|
}
|
|
/* For active transports, pick the most recent ones. */
|
|
if (trans_pri == NULL ||
|
|
ktime_after(trans->last_time_heard,
|
|
trans_pri->last_time_heard)) {
|
|
trans_sec = trans_pri;
|
|
trans_pri = trans;
|
|
} else if (trans_sec == NULL ||
|
|
ktime_after(trans->last_time_heard,
|
|
trans_sec->last_time_heard)) {
|
|
trans_sec = trans;
|
|
}
|
|
}
|
|
|
|
/* 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->state == SCTP_ACTIVE ||
|
|
asoc->peer.primary_path->state == SCTP_UNKNOWN) &&
|
|
asoc->peer.primary_path != trans_pri) {
|
|
trans_sec = trans_pri;
|
|
trans_pri = asoc->peer.primary_path;
|
|
}
|
|
|
|
/* We did not find anything useful for a possible retransmission
|
|
* path; either primary path that we found is the the same as
|
|
* the current one, or we didn't generally find an active one.
|
|
*/
|
|
if (trans_sec == NULL)
|
|
trans_sec = trans_pri;
|
|
|
|
/* If we failed to find a usable transport, just camp on the
|
|
* active or pick a PF iff it's the better choice.
|
|
*/
|
|
if (trans_pri == NULL) {
|
|
trans_pri = sctp_trans_elect_best(asoc->peer.active_path, trans_pf);
|
|
trans_sec = trans_pri;
|
|
}
|
|
|
|
/* Set the active and retran transports. */
|
|
asoc->peer.active_path = trans_pri;
|
|
asoc->peer.retran_path = trans_sec;
|
|
}
|
|
|
|
struct sctp_transport *
|
|
sctp_assoc_choose_alter_transport(struct sctp_association *asoc,
|
|
struct sctp_transport *last_sent_to)
|
|
{
|
|
/* If this is the first time packet is sent, use the active path,
|
|
* else use the retran path. If the last packet was sent over the
|
|
* retran path, update the retran path and use it.
|
|
*/
|
|
if (last_sent_to == NULL) {
|
|
return asoc->peer.active_path;
|
|
} else {
|
|
if (last_sent_to == asoc->peer.retran_path)
|
|
sctp_assoc_update_retran_path(asoc);
|
|
|
|
return asoc->peer.retran_path;
|
|
}
|
|
}
|
|
|
|
void sctp_assoc_update_frag_point(struct sctp_association *asoc)
|
|
{
|
|
int frag = sctp_mtu_payload(sctp_sk(asoc->base.sk), asoc->pathmtu,
|
|
sctp_datachk_len(&asoc->stream));
|
|
|
|
if (asoc->user_frag)
|
|
frag = min_t(int, frag, asoc->user_frag);
|
|
|
|
frag = min_t(int, frag, SCTP_MAX_CHUNK_LEN -
|
|
sctp_datachk_len(&asoc->stream));
|
|
|
|
asoc->frag_point = SCTP_TRUNC4(frag);
|
|
}
|
|
|
|
void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu)
|
|
{
|
|
if (asoc->pathmtu != pmtu) {
|
|
asoc->pathmtu = pmtu;
|
|
sctp_assoc_update_frag_point(asoc);
|
|
}
|
|
|
|
pr_debug("%s: asoc:%p, pmtu:%d, frag_point:%d\n", __func__, asoc,
|
|
asoc->pathmtu, asoc->frag_point);
|
|
}
|
|
|
|
/* 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(struct sctp_association *asoc)
|
|
{
|
|
struct sctp_transport *t;
|
|
__u32 pmtu = 0;
|
|
|
|
if (!asoc)
|
|
return;
|
|
|
|
/* Get the lowest pmtu of all the transports. */
|
|
list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) {
|
|
if (t->pmtu_pending && t->dst) {
|
|
sctp_transport_update_pmtu(t,
|
|
atomic_read(&t->mtu_info));
|
|
t->pmtu_pending = 0;
|
|
}
|
|
if (!pmtu || (t->pathmtu < pmtu))
|
|
pmtu = t->pathmtu;
|
|
}
|
|
|
|
sctp_assoc_set_pmtu(asoc, pmtu);
|
|
}
|
|
|
|
/* Should we send a SACK to update our peer? */
|
|
static inline bool sctp_peer_needs_update(struct sctp_association *asoc)
|
|
{
|
|
struct net *net = sock_net(asoc->base.sk);
|
|
switch (asoc->state) {
|
|
case SCTP_STATE_ESTABLISHED:
|
|
case SCTP_STATE_SHUTDOWN_PENDING:
|
|
case SCTP_STATE_SHUTDOWN_RECEIVED:
|
|
case SCTP_STATE_SHUTDOWN_SENT:
|
|
if ((asoc->rwnd > asoc->a_rwnd) &&
|
|
((asoc->rwnd - asoc->a_rwnd) >= max_t(__u32,
|
|
(asoc->base.sk->sk_rcvbuf >> net->sctp.rwnd_upd_shift),
|
|
asoc->pathmtu)))
|
|
return true;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/* Increase asoc's rwnd by len and send any window update SACK if needed. */
|
|
void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned int len)
|
|
{
|
|
struct sctp_chunk *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;
|
|
}
|
|
|
|
/* If we had window pressure, start recovering it
|
|
* once our rwnd had reached the accumulated pressure
|
|
* threshold. The idea is to recover slowly, but up
|
|
* to the initial advertised window.
|
|
*/
|
|
if (asoc->rwnd_press) {
|
|
int change = min(asoc->pathmtu, asoc->rwnd_press);
|
|
asoc->rwnd += change;
|
|
asoc->rwnd_press -= change;
|
|
}
|
|
|
|
pr_debug("%s: asoc:%p rwnd increased by %d to (%u, %u) - %u\n",
|
|
__func__, 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 (sctp_peer_needs_update(asoc)) {
|
|
asoc->a_rwnd = asoc->rwnd;
|
|
|
|
pr_debug("%s: sending window update SACK- asoc:%p rwnd:%u "
|
|
"a_rwnd:%u\n", __func__, asoc, asoc->rwnd,
|
|
asoc->a_rwnd);
|
|
|
|
sack = sctp_make_sack(asoc);
|
|
if (!sack)
|
|
return;
|
|
|
|
asoc->peer.sack_needed = 0;
|
|
|
|
sctp_outq_tail(&asoc->outqueue, sack, GFP_ATOMIC);
|
|
|
|
/* Stop the SACK timer. */
|
|
timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK];
|
|
if (del_timer(timer))
|
|
sctp_association_put(asoc);
|
|
}
|
|
}
|
|
|
|
/* Decrease asoc's rwnd by len. */
|
|
void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned int len)
|
|
{
|
|
int rx_count;
|
|
int over = 0;
|
|
|
|
if (unlikely(!asoc->rwnd || asoc->rwnd_over))
|
|
pr_debug("%s: association:%p has asoc->rwnd:%u, "
|
|
"asoc->rwnd_over:%u!\n", __func__, asoc,
|
|
asoc->rwnd, asoc->rwnd_over);
|
|
|
|
if (asoc->ep->rcvbuf_policy)
|
|
rx_count = atomic_read(&asoc->rmem_alloc);
|
|
else
|
|
rx_count = atomic_read(&asoc->base.sk->sk_rmem_alloc);
|
|
|
|
/* If we've reached or overflowed our receive buffer, announce
|
|
* a 0 rwnd if rwnd would still be positive. Store the
|
|
* the potential pressure overflow so that the window can be restored
|
|
* back to original value.
|
|
*/
|
|
if (rx_count >= asoc->base.sk->sk_rcvbuf)
|
|
over = 1;
|
|
|
|
if (asoc->rwnd >= len) {
|
|
asoc->rwnd -= len;
|
|
if (over) {
|
|
asoc->rwnd_press += asoc->rwnd;
|
|
asoc->rwnd = 0;
|
|
}
|
|
} else {
|
|
asoc->rwnd_over += len - asoc->rwnd;
|
|
asoc->rwnd = 0;
|
|
}
|
|
|
|
pr_debug("%s: asoc:%p rwnd decreased by %d to (%u, %u, %u)\n",
|
|
__func__, asoc, len, asoc->rwnd, asoc->rwnd_over,
|
|
asoc->rwnd_press);
|
|
}
|
|
|
|
/* 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(struct sctp_association *asoc,
|
|
enum sctp_scope scope, gfp_t gfp)
|
|
{
|
|
int flags;
|
|
|
|
/* Use scoping rules to determine the subset of addresses from
|
|
* the endpoint.
|
|
*/
|
|
flags = (PF_INET6 == asoc->base.sk->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(sock_net(asoc->base.sk),
|
|
&asoc->base.bind_addr,
|
|
&asoc->ep->base.bind_addr,
|
|
scope, gfp, flags);
|
|
}
|
|
|
|
/* Build the association's bind address list from the cookie. */
|
|
int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *asoc,
|
|
struct sctp_cookie *cookie,
|
|
gfp_t gfp)
|
|
{
|
|
int var_size2 = ntohs(cookie->peer_init->chunk_hdr.length);
|
|
int var_size3 = cookie->raw_addr_list_len;
|
|
__u8 *raw = (__u8 *)cookie->peer_init + var_size2;
|
|
|
|
return sctp_raw_to_bind_addrs(&asoc->base.bind_addr, raw, var_size3,
|
|
asoc->ep->base.bind_addr.port, gfp);
|
|
}
|
|
|
|
/* Lookup laddr in the bind address list of an association. */
|
|
int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
|
|
const union sctp_addr *laddr)
|
|
{
|
|
int found = 0;
|
|
|
|
if ((asoc->base.bind_addr.port == ntohs(laddr->v4.sin_port)) &&
|
|
sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
|
|
sctp_sk(asoc->base.sk)))
|
|
found = 1;
|
|
|
|
return found;
|
|
}
|
|
|
|
/* Set an association id for a given association */
|
|
int sctp_assoc_set_id(struct sctp_association *asoc, gfp_t gfp)
|
|
{
|
|
bool preload = gfpflags_allow_blocking(gfp);
|
|
int ret;
|
|
|
|
/* If the id is already assigned, keep it. */
|
|
if (asoc->assoc_id)
|
|
return 0;
|
|
|
|
if (preload)
|
|
idr_preload(gfp);
|
|
spin_lock_bh(&sctp_assocs_id_lock);
|
|
/* 0, 1, 2 are used as SCTP_FUTURE_ASSOC, SCTP_CURRENT_ASSOC and
|
|
* SCTP_ALL_ASSOC, so an available id must be > SCTP_ALL_ASSOC.
|
|
*/
|
|
ret = idr_alloc_cyclic(&sctp_assocs_id, asoc, SCTP_ALL_ASSOC + 1, 0,
|
|
GFP_NOWAIT);
|
|
spin_unlock_bh(&sctp_assocs_id_lock);
|
|
if (preload)
|
|
idr_preload_end();
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
asoc->assoc_id = (sctp_assoc_t)ret;
|
|
return 0;
|
|
}
|
|
|
|
/* Free the ASCONF queue */
|
|
static void sctp_assoc_free_asconf_queue(struct sctp_association *asoc)
|
|
{
|
|
struct sctp_chunk *asconf;
|
|
struct sctp_chunk *tmp;
|
|
|
|
list_for_each_entry_safe(asconf, tmp, &asoc->addip_chunk_list, list) {
|
|
list_del_init(&asconf->list);
|
|
sctp_chunk_free(asconf);
|
|
}
|
|
}
|
|
|
|
/* Free asconf_ack cache */
|
|
static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc)
|
|
{
|
|
struct sctp_chunk *ack;
|
|
struct sctp_chunk *tmp;
|
|
|
|
list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list,
|
|
transmitted_list) {
|
|
list_del_init(&ack->transmitted_list);
|
|
sctp_chunk_free(ack);
|
|
}
|
|
}
|
|
|
|
/* Clean up the ASCONF_ACK queue */
|
|
void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc)
|
|
{
|
|
struct sctp_chunk *ack;
|
|
struct sctp_chunk *tmp;
|
|
|
|
/* We can remove all the entries from the queue up to
|
|
* the "Peer-Sequence-Number".
|
|
*/
|
|
list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list,
|
|
transmitted_list) {
|
|
if (ack->subh.addip_hdr->serial ==
|
|
htonl(asoc->peer.addip_serial))
|
|
break;
|
|
|
|
list_del_init(&ack->transmitted_list);
|
|
sctp_chunk_free(ack);
|
|
}
|
|
}
|
|
|
|
/* Find the ASCONF_ACK whose serial number matches ASCONF */
|
|
struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
|
|
const struct sctp_association *asoc,
|
|
__be32 serial)
|
|
{
|
|
struct sctp_chunk *ack;
|
|
|
|
/* Walk through the list of cached ASCONF-ACKs and find the
|
|
* ack chunk whose serial number matches that of the request.
|
|
*/
|
|
list_for_each_entry(ack, &asoc->asconf_ack_list, transmitted_list) {
|
|
if (sctp_chunk_pending(ack))
|
|
continue;
|
|
if (ack->subh.addip_hdr->serial == serial) {
|
|
sctp_chunk_hold(ack);
|
|
return ack;
|
|
}
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
void sctp_asconf_queue_teardown(struct sctp_association *asoc)
|
|
{
|
|
/* Free any cached ASCONF_ACK chunk. */
|
|
sctp_assoc_free_asconf_acks(asoc);
|
|
|
|
/* Free the ASCONF queue. */
|
|
sctp_assoc_free_asconf_queue(asoc);
|
|
|
|
/* Free any cached ASCONF chunk. */
|
|
if (asoc->addip_last_asconf)
|
|
sctp_chunk_free(asoc->addip_last_asconf);
|
|
}
|