Release 4.11 net/sctp/associola.c

/* SCTP kernel implementation
 * (C) Copyright IBM Corp. 2001, 2004
 * Copyright (c) 1999-2000 Cisco, Inc.
 * Copyright (c) 1999-2001 Motorola, Inc.
 * Copyright (c) 2001 Intel Corp.
 * Copyright (c) 2001 La Monte H.P. Yarroll
 *
 * This file is part of the SCTP kernel implementation
 *
 * This module provides the abstraction for an SCTP association.
 *
 * This SCTP implementation is free software;
 * you can redistribute it and/or modify it under the terms of
 * the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This SCTP implementation is distributed in the hope that it
 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
 *                 ************************
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GNU CC; see the file COPYING.  If not, see
 * <http://www.gnu.org/licenses/>.
 *
 * Please send any bug reports or fixes you make to the
 * email address(es):
 *    lksctp developers <linux-sctp@vger.kernel.org>
 *
 * Written or modified by:
 *    La Monte H.P. Yarroll <piggy@acm.org>
 *    Karl Knutson          <karl@athena.chicago.il.us>
 *    Jon Grimm             <jgrimm@us.ibm.com>
 *    Xingang Guo           <xingang.guo@intel.com>
 *    Hui Huang             <hui.huang@nokia.com>
 *    Sridhar Samudrala     <sri@us.ibm.com>
 *    Daisy Chang           <daisyc@us.ibm.com>
 *    Ryan Layer            <rmlayer@us.ibm.com>
 *    Kevin Gao             <kevin.gao@intel.com>
 */


#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/poll.h>
#include <linux/init.h>

#include <linux/slab.h>
#include <linux/in.h>
#include <net/ipv6.h>
#include <net/sctp/sctp.h>
#include <net/sctp/sm.h>

/* Forward declarations for internal functions. */
static void sctp_select_active_and_retran_path(struct sctp_association *asoc);
static void sctp_assoc_bh_rcv(struct work_struct *work);
static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc);
static void sctp_assoc_free_asconf_queue(struct sctp_association *asoc);

/* 1st Level Abstractions. */

/* Initialize a new association from provided memory. */


static struct sctp_association *sctp_association_init(struct sctp_association *asoc,
					  const struct sctp_endpoint *ep,
					  const struct sock *sk,
					  sctp_scope_t scope,
					  gfp_t gfp)
{
	struct net *net = sock_net(sk);
	struct sctp_sock *sp;
	sctp_paramhdr_t *p;
	int i;

	/* Retrieve the SCTP per socket area.  */
	sp = sctp_sk((struct sock *)sk);

	/* Discarding const is appropriate here.  */
	asoc->ep = (struct sctp_endpoint *)ep;
	asoc->base.sk = (struct sock *)sk;

	sctp_endpoint_hold(asoc->ep);
	sock_hold(asoc->base.sk);

	/* Initialize the common base substructure.  */
	asoc->base.type = SCTP_EP_TYPE_ASSOCIATION;

	/* Initialize the object handling fields.  */
	atomic_set(&asoc->base.refcnt, 1);

	/* Initialize the bind addr area.  */
	sctp_bind_addr_init(&asoc->base.bind_addr, ep->base.bind_addr.port);

	asoc->state = SCTP_STATE_CLOSED;
	asoc->cookie_life = ms_to_ktime(sp->assocparams.sasoc_cookie_life);
	asoc->user_frag = sp->user_frag;

	/* Set the association max_retrans and RTO values from the
         * socket values.
         */
	asoc->max_retrans = sp->assocparams.sasoc_asocmaxrxt;
	asoc->pf_retrans  = net->sctp.pf_retrans;

	asoc->rto_initial = msecs_to_jiffies(sp->rtoinfo.srto_initial);
	asoc->rto_max = msecs_to_jiffies(sp->rtoinfo.srto_max);
	asoc->rto_min = msecs_to_jiffies(sp->rtoinfo.srto_min);

	/* Initialize the association's heartbeat interval based on the
         * sock configured value.
         */
	asoc->hbinterval = msecs_to_jiffies(sp->hbinterval);

	/* Initialize path max retrans value. */
	asoc->pathmaxrxt = sp->pathmaxrxt;

	/* Initialize default path MTU. */
	asoc->pathmtu = sp->pathmtu;

	/* Set association default SACK delay */
	asoc->sackdelay = msecs_to_jiffies(sp->sackdelay);
	asoc->sackfreq = sp->sackfreq;

	/* Set the association default flags controlling
         * Heartbeat, SACK delay, and Path MTU Discovery.
         */
	asoc->param_flags = sp->param_flags;

	/* Initialize the maximum number of new data packets that can be sent
         * in a burst.
         */
	asoc->max_burst = sp->max_burst;

	/* initialize association timers */
	asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] = asoc->rto_initial;
	asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] = asoc->rto_initial;
	asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = asoc->rto_initial;

	/* sctpimpguide Section 2.12.2
         * If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the
         * recommended value of 5 times 'RTO.Max'.
         */
	asoc->timeouts[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]
		= 5 * asoc->rto_max;

	asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = asoc->sackdelay;
	asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] = sp->autoclose * HZ;

	/* Initializes the timers */
	for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i)
		setup_timer(&asoc->timers[i], sctp_timer_events[i],
				(unsigned long)asoc);

	/* Pull default initialization values from the sock options.
         * Note: This assumes that the values have already been
         * validated in the sock.
         */
	asoc->c.sinit_max_instreams = sp->initmsg.sinit_max_instreams;
	asoc->c.sinit_num_ostreams  = sp->initmsg.sinit_num_ostreams;
	asoc->max_init_attempts	= sp->initmsg.sinit_max_attempts;

	asoc->max_init_timeo =
		 msecs_to_jiffies(sp->initmsg.sinit_max_init_timeo);

	/* Set the local window size for receive.
         * This is also the rcvbuf space per association.
         * RFC 6 - A SCTP receiver MUST be able to receive a minimum of
         * 1500 bytes in one SCTP packet.
         */
	if ((sk->sk_rcvbuf/2) < SCTP_DEFAULT_MINWINDOW)
		asoc->rwnd = SCTP_DEFAULT_MINWINDOW;
	else
		asoc->rwnd = sk->sk_rcvbuf/2;

	asoc->a_rwnd = asoc->rwnd;

	/* Use my own max window until I learn something better.  */
	asoc->peer.rwnd = SCTP_DEFAULT_MAXWINDOW;

	/* Initialize the receive memory counter */
	atomic_set(&asoc->rmem_alloc, 0);

	init_waitqueue_head(&asoc->wait);

	asoc->c.my_vtag = sctp_generate_tag(ep);
	asoc->c.my_port = ep->base.bind_addr.port;

	asoc->c.initial_tsn = sctp_generate_tsn(ep);

	asoc->next_tsn = asoc->c.initial_tsn;

	asoc->ctsn_ack_point = asoc->next_tsn - 1;
	asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
	asoc->highest_sacked = asoc->ctsn_ack_point;
	asoc->last_cwr_tsn = asoc->ctsn_ack_point;

	/* ADDIP Section 4.1 Asconf Chunk Procedures
         *
         * When an endpoint has an ASCONF signaled change to be sent to the
         * remote endpoint it should do the following:
         * ...
         * A2) a serial number should be assigned to the chunk. The serial
         * number SHOULD be a monotonically increasing number. The serial
         * numbers SHOULD be initialized at the start of the
         * association to the same value as the initial TSN.
         */
	asoc->addip_serial = asoc->c.initial_tsn;
	asoc->strreset_outseq = asoc->c.initial_tsn;

	INIT_LIST_HEAD(&asoc->addip_chunk_list);
	INIT_LIST_HEAD(&asoc->asconf_ack_list);

	/* Make an empty list of remote transport addresses.  */
	INIT_LIST_HEAD(&asoc->peer.transport_addr_list);

	/* RFC 2960 5.1 Normal Establishment of an Association
         *
         * After the reception of the first data chunk in an
         * association the endpoint must immediately respond with a
         * sack to acknowledge the data chunk.  Subsequent
         * acknowledgements should be done as described in Section
         * 6.2.
         *
         * [We implement this by telling a new association that it
         * already received one packet.]
         */
	asoc->peer.sack_needed = 1;
	asoc->peer.sack_generation = 1;

	/* Assume that the peer will tell us if he recognizes ASCONF
         * as part of INIT exchange.
         * The sctp_addip_noauth option is there for backward compatibility
         * and will revert old behavior.
         */
	if (net->sctp.addip_noauth)
		asoc->peer.asconf_capable = 1;

	/* Create an input queue.  */
	sctp_inq_init(&asoc->base.inqueue);
	sctp_inq_set_th_handler(&asoc->base.inqueue, sctp_assoc_bh_rcv);

	/* Create an output queue.  */
	sctp_outq_init(asoc, &asoc->outqueue);

	if (!sctp_ulpq_init(&asoc->ulpq, asoc))
		goto fail_init;

	if (sctp_stream_new(asoc, gfp))
		goto fail_init;

	/* Assume that peer would support both address types unless we are
         * told otherwise.
         */
	asoc->peer.ipv4_address = 1;
	if (asoc->base.sk->sk_family == PF_INET6)
		asoc->peer.ipv6_address = 1;
	INIT_LIST_HEAD(&asoc->asocs);

	asoc->default_stream = sp->default_stream;
	asoc->default_ppid = sp->default_ppid;
	asoc->default_flags = sp->default_flags;
	asoc->default_context = sp->default_context;
	asoc->default_timetolive = sp->default_timetolive;
	asoc->default_rcv_context = sp->default_rcv_context;

	/* AUTH related initializations */
	INIT_LIST_HEAD(&asoc->endpoint_shared_keys);
	if (sctp_auth_asoc_copy_shkeys(ep, asoc, gfp))
		goto stream_free;

	asoc->active_key_id = ep->active_key_id;
	asoc->prsctp_enable = ep->prsctp_enable;
	asoc->reconf_enable = ep->reconf_enable;
	asoc->strreset_enable = ep->strreset_enable;

	/* Save the hmacs and chunks list into this association */
	if (ep->auth_hmacs_list)
		memcpy(asoc->c.auth_hmacs, ep->auth_hmacs_list,
			ntohs(ep->auth_hmacs_list->param_hdr.length));
	if (ep->auth_chunk_list)
		memcpy(asoc->c.auth_chunks, ep->auth_chunk_list,
			ntohs(ep->auth_chunk_list->param_hdr.length));

	/* Get the AUTH random number for this association */
	p = (sctp_paramhdr_t *)asoc->c.auth_random;
	p->type = SCTP_PARAM_RANDOM;
	p->length = htons(sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH);
	get_random_bytes(p+1, SCTP_AUTH_RANDOM_LENGTH);

	return asoc;

stream_free:
	sctp_stream_free(asoc->stream);
fail_init:
	sock_put(asoc->base.sk);
	sctp_endpoint_put(asoc->ep);
	return NULL;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Jon Grimm
474
46.24%
11
21.15%
Vladislav Yasevich
231
22.54%
6
11.54%
Sridhar Samudrala
89
8.68%
9
17.31%
Xin Long
59
5.76%
6
11.54%
Frank Filz
54
5.27%
1
1.92%
Neil Horman
29
2.83%
4
7.69%
Wei Yongjun
24
2.34%
2
3.85%
Eric W. Biedermann
20
1.95%
1
1.92%
Daniel Borkmann
16
1.56%
2
3.85%
Ivan Skytte Jörgensen
8
0.78%
1
1.92%
David S. Miller
6
0.59%
2
3.85%
Pavel Emelyanov
4
0.39%
1
1.92%
Andrew Morton
4
0.39%
1
1.92%
Arnaldo Carvalho de Melo
3
0.29%
2
3.85%
Wang Weidong
2
0.20%
1
1.92%
Uwe Kleine-König
1
0.10%
1
1.92%
Al Viro
1
0.10%
1
1.92%
Total
1025
100.00%
52
100.00%

/* Allocate and initialize a new association */


struct sctp_association *sctp_association_new(const struct sctp_endpoint *ep,
					 const struct sock *sk,
					 sctp_scope_t scope,
					 gfp_t gfp)
{
	struct sctp_association *asoc;

	asoc = kzalloc(sizeof(*asoc), gfp);
	if (!asoc)
		goto fail;

	if (!sctp_association_init(asoc, ep, sk, scope, gfp))
		goto fail_init;

	SCTP_DBG_OBJCNT_INC(assoc);

	pr_debug("Created asoc %p\n", asoc);

	return asoc;

fail_init:
	kfree(asoc);
fail:
	return NULL;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Sridhar Samudrala
83
85.57%
1
20.00%
Daniel Borkmann
7
7.22%
2
40.00%
Frank Filz
6
6.19%
1
20.00%
Al Viro
1
1.03%
1
20.00%
Total
97
100.00%
5
100.00%

/* Free this association if possible.  There may still be users, so
 * the actual deallocation may be delayed.
 */


void sctp_association_free(struct sctp_association *asoc)
{
	struct sock *sk = asoc->base.sk;
	struct sctp_transport *transport;
	struct list_head *pos, *temp;
	int i;

	/* Only real associations count against the endpoint, so
         * don't bother for if this is a temporary association.
         */
	if (!list_empty(&asoc->asocs)) {
		list_del(&asoc->asocs);

		/* Decrement the backlog value for a TCP-style listening
                 * socket.
                 */
		if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
			sk->sk_ack_backlog--;
	}

	/* Mark as dead, so other users can know this structure is
         * going away.
         */
	asoc->base.dead = true;

	/* Dispose of any data lying around in the outqueue. */
	sctp_outq_free(&asoc->outqueue);

	/* Dispose of any pending messages for the upper layer. */
	sctp_ulpq_free(&asoc->ulpq);

	/* Dispose of any pending chunks on the inqueue. */
	sctp_inq_free(&asoc->base.inqueue);

	sctp_tsnmap_free(&asoc->peer.tsn_map);

	/* Free stream information. */
	sctp_stream_free(asoc->stream);

	if (asoc->strreset_chunk)
		sctp_chunk_free(asoc->strreset_chunk);

	/* Clean up the bound address list. */
	sctp_bind_addr_free(&asoc->base.bind_addr);

	/* Do we need to go through all of our timers and
         * delete them?   To be safe we will try to delete all, but we
         * should be able to go through and make a guess based
         * on our state.
         */
	for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) {
		if (del_timer(&asoc->timers[i]))
			sctp_association_put(asoc);
	}

	/* Free peer's cached cookie. */
	kfree(asoc->peer.cookie);
	kfree(asoc->peer.peer_random);
	kfree(asoc->peer.peer_chunks);
	kfree(asoc->peer.peer_hmacs);

	/* Release the transport structures. */
	list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
		transport = list_entry(pos, struct sctp_transport, transports);
		list_del_rcu(pos);
		sctp_unhash_transport(transport);
		sctp_transport_free(transport);
	}

	asoc->peer.transport_count = 0;

	sctp_asconf_queue_teardown(asoc);

	/* Free pending address space being deleted */
	kfree(asoc->asconf_addr_del_pending);

	/* AUTH - Free the endpoint shared keys */
	sctp_auth_destroy_keys(&asoc->endpoint_shared_keys);

	/* AUTH - Free the association shared key */
	sctp_auth_key_put(asoc->asoc_shared_key);

	sctp_association_put(asoc);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Jon Grimm
163
52.08%
6
24.00%
Vladislav Yasevich
64
20.45%
4
16.00%
Sridhar Samudrala
35
11.18%
3
12.00%
Xin Long
21
6.71%
3
12.00%
Frank Filz
8
2.56%
1
4.00%
Michio Honda
8
2.56%
1
4.00%
Xufeng Zhang
5
1.60%
1
4.00%
David S. Miller
3
0.96%
1
4.00%
Rusty Russell
2
0.64%
1
4.00%
Wei Yongjun
1
0.32%
1
4.00%
Arnaldo Carvalho de Melo
1
0.32%
1
4.00%
Thomas Graf
1
0.32%
1
4.00%
Daniel Borkmann
1
0.32%
1
4.00%
Total
313
100.00%
25
100.00%

/* Cleanup and free up an association. */


static void sctp_association_destroy(struct sctp_association *asoc)
{
	if (unlikely(!asoc->base.dead)) {
		WARN(1, "Attempt to destroy undead association %p!\n", asoc);
		return;
	}

	sctp_endpoint_put(asoc->ep);
	sock_put(asoc->base.sk);

	if (asoc->assoc_id != 0) {
		spin_lock_bh(&sctp_assocs_id_lock);
		idr_remove(&sctp_assocs_id, asoc->assoc_id);
		spin_unlock_bh(&sctp_assocs_id_lock);
	}

	WARN_ON(atomic_read(&asoc->rmem_alloc));

	kfree(asoc);
	SCTP_DBG_OBJCNT_DEC(assoc);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Jon Grimm
43
41.35%
2
28.57%
Sridhar Samudrala
30
28.85%
2
28.57%
Daniel Borkmann
20
19.23%
1
14.29%
Neil Horman
10
9.62%
1
14.29%
Ilpo Järvinen
1
0.96%
1
14.29%
Total
104
100.00%
7
100.00%

/* Change the primary destination address for the peer. */


void sctp_assoc_set_primary(struct sctp_association *asoc,
			    struct sctp_transport *transport)
{
	int changeover = 0;

	/* it's a changeover only if we already have a primary path
         * that we are changing
         */
	if (asoc->peer.primary_path != NULL &&
	    asoc->peer.primary_path != transport)
		changeover = 1 ;

	asoc->peer.primary_path = transport;

	/* Set a default msg_name for events. */
	memcpy(&asoc->peer.primary_addr, &transport->ipaddr,
	       sizeof(union sctp_addr));

	/* If the primary path is changing, assume that the
         * user wants to use this new path.
         */
	if ((transport->state == SCTP_ACTIVE) ||
	    (transport->state == SCTP_UNKNOWN))
		asoc->peer.active_path = transport;

	/*
         * SFR-CACC algorithm:
         * Upon the receipt of a request to change the primary
         * destination address, on the data structure for the new
         * primary destination, the sender MUST do the following:
         *
         * 1) If CHANGEOVER_ACTIVE is set, then there was a switch
         * to this destination address earlier. The sender MUST set
         * CYCLING_CHANGEOVER to indicate that this switch is a
         * double switch to the same destination address.
         *
         * Really, only bother is we have data queued or outstanding on
         * the association.
         */
	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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Jon Grimm
93
60.39%
2
33.33%
Vladislav Yasevich
48
31.17%
2
33.33%
Sridhar Samudrala
12
7.79%
1
16.67%
Frank Filz
1
0.65%
1
16.67%
Total
154
100.00%
6
100.00%

/* Remove a transport from an association.  */


void sctp_assoc_rm_peer(struct sctp_association *asoc,
			struct sctp_transport *peer)
{
	struct list_head	*pos;
	struct sctp_transport	*transport;

	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;
		struct sctp_chunk *ch;

		/* 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);
	}

	asoc->peer.transport_count--;

	sctp_transport_free(peer);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Frank Filz
164
45.43%
1
9.09%
Vladislav Yasevich
99
27.42%
1
9.09%
Wei Yongjun
56
15.51%
3
27.27%
Xin Long
35
9.70%
2
18.18%
Daniel Borkmann
4
1.11%
1
9.09%
Thomas Graf
1
0.28%
1
9.09%
Al Viro
1
0.28%
1
9.09%
Wang Weidong
1
0.28%
1
9.09%
Total
361
100.00%
11
100.00%

/* 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;

	/* Enable/disable heartbeat, SACK delay, and path MTU discovery
         * based on association setting.
         */
	peer->param_flags = asoc->param_flags;

	sctp_transport_route(peer, NULL, sp);

	/* Initialize the pmtu of the transport. */
	if (peer->param_flags & SPP_PMTUD_DISABLE) {
		if (asoc->pathmtu)
			peer->pathmtu = asoc->pathmtu;
		else
			peer->pathmtu = SCTP_DEFAULT_MAXSEGMENT;
	}

	/* If this is the first transport addr on this association,
         * initialize the association PMTU to the peer's PMTU.
         * If not and the current association PMTU is higher than the new
         * peer's PMTU, reset the association PMTU to the new peer's PMTU.
         */
	if (asoc->pathmtu)
		asoc->pathmtu = min_t(int, peer->pathmtu, asoc->pathmtu);
	else
		asoc->pathmtu = peer->pathmtu;

	pr_debug("%s: association:%p PMTU set to %d\n", __func__, asoc,
		 asoc->pathmtu);

	peer->pmtu_pending = 0;

	asoc->frag_point = sctp_frag_point(asoc, asoc->pathmtu);

	/* 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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Jon Grimm
283
53.00%
12
32.43%
Frank Filz
112
20.97%
2
5.41%
Sridhar Samudrala
31
5.81%
5
13.51%
Vladislav Yasevich
26
4.87%
5
13.51%
Xin Long
18
3.37%
1
2.70%
Eric W. Biedermann
16
3.00%
1
2.70%
Daniel Borkmann
10
1.87%
1
2.70%
Neil Horman
8
1.50%
1
2.70%
Wei Yongjun
8
1.50%
1
2.70%
Michele Baldessari
7
1.31%
1
2.70%
Florian Westphal
6
1.12%
1
2.70%
Al Viro
4
0.75%
2
5.41%
David S. Miller
2
0.37%
1
2.70%
Thomas Graf
1
0.19%
1
2.70%
Arnaldo Carvalho de Melo
1
0.19%
1
2.70%
Wang Weidong
1
0.19%
1
2.70%
Total
534
100.00%
37
100.00%

/* 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;
		}
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Sridhar Samudrala
71
93.42%
1
50.00%
Frank Filz
5
6.58%
1
50.00%
Total
76
100.00%
2
100.00%

/* 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;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Jon Grimm
49
92.45%
4
80.00%
Robert P. J. Day
4
7.55%
1
20.00%
Total
53
100.00%
5
100.00%

/* 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);
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Vladislav Yasevich
51
100.00%
1
100.00%
Total
51
100.00%
1
100.00%

/* 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,
				  sctp_transport_cmd_t 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;
		}