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|
/* SCTP kernel implementation
* Copyright (c) 1999-2000 Cisco, Inc.
* Copyright (c) 1999-2001 Motorola, Inc.
* Copyright (c) 2001-2003 International Business Machines Corp.
* Copyright (c) 2001 Intel Corp.
* Copyright (c) 2001 La Monte H.P. Yarroll
*
* This file is part of the SCTP kernel implementation
*
* This module provides the abstraction for an SCTP tranport representing
* a remote transport address. For local transport addresses, we just use
* union sctp_addr.
*
* 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, write to
* the Free Software Foundation, 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*
* Please send any bug reports or fixes you make to the
* email address(es):
* lksctp developers <lksctp-developers@lists.sourceforge.net>
*
* Or submit a bug report through the following website:
* http://www.sf.net/projects/lksctp
*
* Written or modified by:
* La Monte H.P. Yarroll <piggy@acm.org>
* Karl Knutson <karl@athena.chicago.il.us>
* Jon Grimm <jgrimm@us.ibm.com>
* Xingang Guo <xingang.guo@intel.com>
* Hui Huang <hui.huang@nokia.com>
* Sridhar Samudrala <sri@us.ibm.com>
* Ardelle Fan <ardelle.fan@intel.com>
*
* Any bugs reported given to us we will try to fix... any fixes shared will
* be incorporated into the next SCTP release.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/random.h>
#include <net/sctp/sctp.h>
#include <net/sctp/sm.h>
/* 1st Level Abstractions. */
/* Initialize a new transport from provided memory. */
static struct sctp_transport *sctp_transport_init(struct sctp_transport *peer,
const union sctp_addr *addr,
gfp_t gfp)
{
/* Copy in the address. */
peer->ipaddr = *addr;
peer->af_specific = sctp_get_af_specific(addr->sa.sa_family);
memset(&peer->saddr, 0, sizeof(union sctp_addr));
/* From 6.3.1 RTO Calculation:
*
* C1) Until an RTT measurement has been made for a packet sent to the
* given destination transport address, set RTO to the protocol
* parameter 'RTO.Initial'.
*/
peer->rto = msecs_to_jiffies(sctp_rto_initial);
peer->last_time_heard = jiffies;
peer->last_time_ecne_reduced = jiffies;
peer->param_flags = SPP_HB_DISABLE |
SPP_PMTUD_ENABLE |
SPP_SACKDELAY_ENABLE;
/* Initialize the default path max_retrans. */
peer->pathmaxrxt = sctp_max_retrans_path;
INIT_LIST_HEAD(&peer->transmitted);
INIT_LIST_HEAD(&peer->send_ready);
INIT_LIST_HEAD(&peer->transports);
setup_timer(&peer->T3_rtx_timer, sctp_generate_t3_rtx_event,
(unsigned long)peer);
setup_timer(&peer->hb_timer, sctp_generate_heartbeat_event,
(unsigned long)peer);
setup_timer(&peer->proto_unreach_timer,
sctp_generate_proto_unreach_event, (unsigned long)peer);
/* Initialize the 64-bit random nonce sent with heartbeat. */
get_random_bytes(&peer->hb_nonce, sizeof(peer->hb_nonce));
atomic_set(&peer->refcnt, 1);
return peer;
}
/* Allocate and initialize a new transport. */
struct sctp_transport *sctp_transport_new(const union sctp_addr *addr,
gfp_t gfp)
{
struct sctp_transport *transport;
transport = t_new(struct sctp_transport, gfp);
if (!transport)
goto fail;
if (!sctp_transport_init(transport, addr, gfp))
goto fail_init;
transport->malloced = 1;
SCTP_DBG_OBJCNT_INC(transport);
return transport;
fail_init:
kfree(transport);
fail:
return NULL;
}
/* This transport is no longer needed. Free up if possible, or
* delay until it last reference count.
*/
void sctp_transport_free(struct sctp_transport *transport)
{
transport->dead = 1;
/* Try to delete the heartbeat timer. */
if (del_timer(&transport->hb_timer))
sctp_transport_put(transport);
/* Delete the T3_rtx timer if it's active.
* There is no point in not doing this now and letting
* structure hang around in memory since we know
* the tranport is going away.
*/
if (timer_pending(&transport->T3_rtx_timer) &&
del_timer(&transport->T3_rtx_timer))
sctp_transport_put(transport);
/* Delete the ICMP proto unreachable timer if it's active. */
if (timer_pending(&transport->proto_unreach_timer) &&
del_timer(&transport->proto_unreach_timer))
sctp_association_put(transport->asoc);
sctp_transport_put(transport);
}
/* Destroy the transport data structure.
* Assumes there are no more users of this structure.
*/
static void sctp_transport_destroy(struct sctp_transport *transport)
{
SCTP_ASSERT(transport->dead, "Transport is not dead", return);
if (transport->asoc)
sctp_association_put(transport->asoc);
sctp_packet_free(&transport->packet);
dst_release(transport->dst);
kfree(transport);
SCTP_DBG_OBJCNT_DEC(transport);
}
/* Start T3_rtx timer if it is not already running and update the heartbeat
* timer. This routine is called every time a DATA chunk is sent.
*/
void sctp_transport_reset_timers(struct sctp_transport *transport)
{
/* RFC 2960 6.3.2 Retransmission Timer Rules
*
* R1) Every time a DATA chunk is sent to any address(including a
* retransmission), if the T3-rtx timer of that address is not running
* start it running so that it will expire after the RTO of that
* address.
*/
if (!timer_pending(&transport->T3_rtx_timer))
if (!mod_timer(&transport->T3_rtx_timer,
jiffies + transport->rto))
sctp_transport_hold(transport);
/* When a data chunk is sent, reset the heartbeat interval. */
if (!mod_timer(&transport->hb_timer,
sctp_transport_timeout(transport)))
sctp_transport_hold(transport);
}
/* This transport has been assigned to an association.
* Initialize fields from the association or from the sock itself.
* Register the reference count in the association.
*/
void sctp_transport_set_owner(struct sctp_transport *transport,
struct sctp_association *asoc)
{
transport->asoc = asoc;
sctp_association_hold(asoc);
}
/* Initialize the pmtu of a transport. */
void sctp_transport_pmtu(struct sctp_transport *transport, struct sock *sk)
{
/* If we don't have a fresh route, look one up */
if (!transport->dst || transport->dst->obsolete > 1) {
dst_release(transport->dst);
transport->af_specific->get_dst(transport, &transport->saddr,
&transport->fl, sk);
}
if (transport->dst) {
transport->pathmtu = dst_mtu(transport->dst);
} else
transport->pathmtu = SCTP_DEFAULT_MAXSEGMENT;
}
void sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu)
{
struct dst_entry *dst;
if (unlikely(pmtu < SCTP_DEFAULT_MINSEGMENT)) {
pr_warn("%s: Reported pmtu %d too low, using default minimum of %d\n",
__func__, pmtu,
SCTP_DEFAULT_MINSEGMENT);
/* Use default minimum segment size and disable
* pmtu discovery on this transport.
*/
t->pathmtu = SCTP_DEFAULT_MINSEGMENT;
} else {
t->pathmtu = pmtu;
}
dst = sctp_transport_dst_check(t);
if (dst)
dst->ops->update_pmtu(dst, pmtu);
}
/* Caches the dst entry and source address for a transport's destination
* address.
*/
void sctp_transport_route(struct sctp_transport *transport,
union sctp_addr *saddr, struct sctp_sock *opt)
{
struct sctp_association *asoc = transport->asoc;
struct sctp_af *af = transport->af_specific;
af->get_dst(transport, saddr, &transport->fl, sctp_opt2sk(opt));
if (saddr)
memcpy(&transport->saddr, saddr, sizeof(union sctp_addr));
else
af->get_saddr(opt, transport, &transport->fl);
if ((transport->param_flags & SPP_PMTUD_DISABLE) && transport->pathmtu) {
return;
}
if (transport->dst) {
transport->pathmtu = dst_mtu(transport->dst);
/* Initialize sk->sk_rcv_saddr, if the transport is the
* association's active path for getsockname().
*/
|