388 строки
10 KiB
C
388 строки
10 KiB
C
/* SCTP kernel reference Implementation
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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) 2001-2002 International Business Machines, Corp.
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* Copyright (c) 2001 Intel Corp.
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* Copyright (c) 2001 Nokia, Inc.
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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 reference Implementation
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*
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* This abstraction represents an SCTP endpoint.
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*
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* This file is part of the implementation of the add-IP extension,
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* based on <draft-ietf-tsvwg-addip-sctp-02.txt> June 29, 2001,
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* for the SCTP kernel reference Implementation.
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*
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* The SCTP reference implementation is free software;
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* you can redistribute it and/or modify it under the terms of
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* the GNU General Public License as published by
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* the Free Software Foundation; either version 2, or (at your option)
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* any later version.
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*
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* The SCTP reference implementation is distributed in the hope that it
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* will be useful, but WITHOUT ANY WARRANTY; without even the implied
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* ************************
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* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
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* See the GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with GNU CC; see the file COPYING. If not, write to
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* the Free Software Foundation, 59 Temple Place - Suite 330,
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* Boston, MA 02111-1307, USA.
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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 <lksctp-developers@lists.sourceforge.net>
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*
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* Or submit a bug report through the following website:
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* http://www.sf.net/projects/lksctp
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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@austin.ibm.com>
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* Daisy Chang <daisyc@us.ibm.com>
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* Dajiang Zhang <dajiang.zhang@nokia.com>
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*
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* Any bugs reported given to us we will try to fix... any fixes shared will
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* be incorporated into the next SCTP release.
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*/
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#include <linux/types.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/in.h>
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#include <linux/random.h> /* get_random_bytes() */
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#include <linux/crypto.h>
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#include <net/sock.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 helpers. */
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static void sctp_endpoint_bh_rcv(struct sctp_endpoint *ep);
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/*
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* Initialize the base fields of the endpoint structure.
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*/
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static struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep,
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struct sock *sk,
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unsigned int __nocast gfp)
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{
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struct sctp_sock *sp = sctp_sk(sk);
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memset(ep, 0, sizeof(struct sctp_endpoint));
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/* Initialize the base structure. */
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/* What type of endpoint are we? */
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ep->base.type = SCTP_EP_TYPE_SOCKET;
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/* Initialize the basic object fields. */
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atomic_set(&ep->base.refcnt, 1);
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ep->base.dead = 0;
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ep->base.malloced = 1;
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/* Create an input queue. */
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sctp_inq_init(&ep->base.inqueue);
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/* Set its top-half handler */
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sctp_inq_set_th_handler(&ep->base.inqueue,
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(void (*)(void *))sctp_endpoint_bh_rcv, ep);
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/* Initialize the bind addr area */
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sctp_bind_addr_init(&ep->base.bind_addr, 0);
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rwlock_init(&ep->base.addr_lock);
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/* Remember who we are attached to. */
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ep->base.sk = sk;
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sock_hold(ep->base.sk);
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/* Create the lists of associations. */
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INIT_LIST_HEAD(&ep->asocs);
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/* Set up the base timeout information. */
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ep->timeouts[SCTP_EVENT_TIMEOUT_NONE] = 0;
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ep->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
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msecs_to_jiffies(sp->rtoinfo.srto_initial);
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ep->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
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msecs_to_jiffies(sp->rtoinfo.srto_initial);
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ep->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] =
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msecs_to_jiffies(sp->rtoinfo.srto_initial);
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ep->timeouts[SCTP_EVENT_TIMEOUT_T3_RTX] = 0;
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ep->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = 0;
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/* sctpimpguide-05 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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ep->timeouts[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]
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= 5 * msecs_to_jiffies(sp->rtoinfo.srto_max);
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ep->timeouts[SCTP_EVENT_TIMEOUT_HEARTBEAT] = 0;
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ep->timeouts[SCTP_EVENT_TIMEOUT_SACK] = sctp_sack_timeout;
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ep->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] = sp->autoclose * HZ;
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/* Use SCTP specific send buffer space queues. */
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ep->sndbuf_policy = sctp_sndbuf_policy;
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sk->sk_write_space = sctp_write_space;
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sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);
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/* Initialize the secret key used with cookie. */
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get_random_bytes(&ep->secret_key[0], SCTP_SECRET_SIZE);
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ep->last_key = ep->current_key = 0;
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ep->key_changed_at = jiffies;
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return ep;
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}
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/* Create a sctp_endpoint with all that boring stuff initialized.
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* Returns NULL if there isn't enough memory.
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*/
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struct sctp_endpoint *sctp_endpoint_new(struct sock *sk,
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unsigned int __nocast gfp)
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{
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struct sctp_endpoint *ep;
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/* Build a local endpoint. */
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ep = t_new(struct sctp_endpoint, gfp);
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if (!ep)
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goto fail;
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if (!sctp_endpoint_init(ep, sk, gfp))
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goto fail_init;
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ep->base.malloced = 1;
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SCTP_DBG_OBJCNT_INC(ep);
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return ep;
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fail_init:
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kfree(ep);
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fail:
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return NULL;
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}
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/* Add an association to an endpoint. */
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void sctp_endpoint_add_asoc(struct sctp_endpoint *ep,
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struct sctp_association *asoc)
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{
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struct sock *sk = ep->base.sk;
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/* Now just add it to our list of asocs */
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list_add_tail(&asoc->asocs, &ep->asocs);
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/* Increment the backlog value for a TCP-style listening socket. */
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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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/* Free the endpoint structure. Delay cleanup until
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* all users have released their reference count on this structure.
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*/
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void sctp_endpoint_free(struct sctp_endpoint *ep)
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{
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ep->base.dead = 1;
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sctp_endpoint_put(ep);
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}
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/* Final destructor for endpoint. */
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static void sctp_endpoint_destroy(struct sctp_endpoint *ep)
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{
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SCTP_ASSERT(ep->base.dead, "Endpoint is not dead", return);
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ep->base.sk->sk_state = SCTP_SS_CLOSED;
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/* Unlink this endpoint, so we can't find it again! */
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sctp_unhash_endpoint(ep);
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/* Free up the HMAC transform. */
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sctp_crypto_free_tfm(sctp_sk(ep->base.sk)->hmac);
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/* Cleanup. */
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sctp_inq_free(&ep->base.inqueue);
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sctp_bind_addr_free(&ep->base.bind_addr);
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/* Remove and free the port */
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if (sctp_sk(ep->base.sk)->bind_hash)
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sctp_put_port(ep->base.sk);
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/* Give up our hold on the sock. */
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if (ep->base.sk)
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sock_put(ep->base.sk);
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/* Finally, free up our memory. */
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if (ep->base.malloced) {
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kfree(ep);
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SCTP_DBG_OBJCNT_DEC(ep);
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}
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}
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/* Hold a reference to an endpoint. */
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void sctp_endpoint_hold(struct sctp_endpoint *ep)
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{
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atomic_inc(&ep->base.refcnt);
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}
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/* Release a reference to an endpoint and clean up if there are
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* no more references.
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*/
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void sctp_endpoint_put(struct sctp_endpoint *ep)
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{
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if (atomic_dec_and_test(&ep->base.refcnt))
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sctp_endpoint_destroy(ep);
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}
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/* Is this the endpoint we are looking for? */
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struct sctp_endpoint *sctp_endpoint_is_match(struct sctp_endpoint *ep,
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const union sctp_addr *laddr)
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{
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struct sctp_endpoint *retval;
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sctp_read_lock(&ep->base.addr_lock);
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if (ep->base.bind_addr.port == laddr->v4.sin_port) {
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if (sctp_bind_addr_match(&ep->base.bind_addr, laddr,
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sctp_sk(ep->base.sk))) {
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retval = ep;
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goto out;
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}
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}
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retval = NULL;
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out:
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sctp_read_unlock(&ep->base.addr_lock);
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return retval;
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}
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/* Find the association that goes with this chunk.
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* We do a linear search of the associations for this endpoint.
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* We return the matching transport address too.
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*/
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static struct sctp_association *__sctp_endpoint_lookup_assoc(
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const struct sctp_endpoint *ep,
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const union sctp_addr *paddr,
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struct sctp_transport **transport)
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{
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int rport;
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struct sctp_association *asoc;
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struct list_head *pos;
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rport = paddr->v4.sin_port;
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list_for_each(pos, &ep->asocs) {
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asoc = list_entry(pos, struct sctp_association, asocs);
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if (rport == asoc->peer.port) {
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sctp_read_lock(&asoc->base.addr_lock);
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*transport = sctp_assoc_lookup_paddr(asoc, paddr);
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sctp_read_unlock(&asoc->base.addr_lock);
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if (*transport)
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return asoc;
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}
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}
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*transport = NULL;
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return NULL;
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}
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/* Lookup association on an endpoint based on a peer address. BH-safe. */
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struct sctp_association *sctp_endpoint_lookup_assoc(
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const struct sctp_endpoint *ep,
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const union sctp_addr *paddr,
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struct sctp_transport **transport)
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{
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struct sctp_association *asoc;
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sctp_local_bh_disable();
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asoc = __sctp_endpoint_lookup_assoc(ep, paddr, transport);
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sctp_local_bh_enable();
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return asoc;
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}
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/* Look for any peeled off association from the endpoint that matches the
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* given peer address.
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*/
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int sctp_endpoint_is_peeled_off(struct sctp_endpoint *ep,
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const union sctp_addr *paddr)
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{
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struct list_head *pos;
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struct sctp_sockaddr_entry *addr;
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struct sctp_bind_addr *bp;
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sctp_read_lock(&ep->base.addr_lock);
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bp = &ep->base.bind_addr;
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list_for_each(pos, &bp->address_list) {
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addr = list_entry(pos, struct sctp_sockaddr_entry, list);
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if (sctp_has_association(&addr->a, paddr)) {
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sctp_read_unlock(&ep->base.addr_lock);
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return 1;
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}
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}
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sctp_read_unlock(&ep->base.addr_lock);
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return 0;
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}
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/* Do delayed input processing. This is scheduled by sctp_rcv().
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* This may be called on BH or task time.
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*/
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static void sctp_endpoint_bh_rcv(struct sctp_endpoint *ep)
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{
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struct sctp_association *asoc;
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struct sock *sk;
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struct sctp_transport *transport;
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struct sctp_chunk *chunk;
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struct sctp_inq *inqueue;
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sctp_subtype_t subtype;
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sctp_state_t state;
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int error = 0;
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if (ep->base.dead)
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return;
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asoc = NULL;
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inqueue = &ep->base.inqueue;
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sk = ep->base.sk;
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while (NULL != (chunk = sctp_inq_pop(inqueue))) {
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subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
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/* We might have grown an association since last we
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* looked, so try again.
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*
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* This happens when we've just processed our
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* COOKIE-ECHO chunk.
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*/
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if (NULL == chunk->asoc) {
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asoc = sctp_endpoint_lookup_assoc(ep,
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sctp_source(chunk),
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&transport);
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chunk->asoc = asoc;
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chunk->transport = transport;
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}
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state = asoc ? asoc->state : SCTP_STATE_CLOSED;
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/* Remember where the last DATA chunk came from so we
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* know where to send the SACK.
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*/
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if (asoc && sctp_chunk_is_data(chunk))
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asoc->peer.last_data_from = chunk->transport;
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else
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SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS);
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if (chunk->transport)
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chunk->transport->last_time_heard = jiffies;
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error = sctp_do_sm(SCTP_EVENT_T_CHUNK, subtype, state,
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ep, asoc, chunk, GFP_ATOMIC);
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if (error && chunk)
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chunk->pdiscard = 1;
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/* Check to see if the endpoint is freed in response to
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* the incoming chunk. If so, get out of the while loop.
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*/
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if (!sctp_sk(sk)->ep)
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break;
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}
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}
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