11  * This module provides the abstraction for an SCTP transport representing
12  * a remote transport address.  For local transport addresses, we just use
39 /* Initialize a new transport from provided memory.  */
55 	 * given destination transport address, set RTO to the protocol
90 /* Allocate and initialize a new transport.  */
95 	struct sctp_transport *transport;
97 	transport = kzalloc(sizeof(*transport), gfp);
98 	if (!transport)
101 	if (!sctp_transport_init(net, transport, addr, gfp))
104 	SCTP_DBG_OBJCNT_INC(transport);
106 	return transport;
109 	kfree(transport);
115 /* This transport is no longer needed.  Free up if possible, or
118 void sctp_transport_free(struct sctp_transport *transport)
121 	if (del_timer(&transport->hb_timer))
122 		sctp_transport_put(transport);
127 	 * the transport is going away.
129 	if (del_timer(&transport->T3_rtx_timer))
130 		sctp_transport_put(transport);
132 	if (del_timer(&transport->reconf_timer))
133 		sctp_transport_put(transport);
135 	if (del_timer(&transport->probe_timer))
136 		sctp_transport_put(transport);
139 	if (del_timer(&transport->proto_unreach_timer))
140 		sctp_transport_put(transport);
142 	sctp_transport_put(transport);
147 	struct sctp_transport *transport;
149 	transport = container_of(head, struct sctp_transport, rcu);
151 	dst_release(transport->dst);
152 	kfree(transport);
153 	SCTP_DBG_OBJCNT_DEC(transport);
156 /* Destroy the transport data structure.
159 static void sctp_transport_destroy(struct sctp_transport *transport)
161 	if (unlikely(refcount_read(&transport->refcnt))) {
162 		WARN(1, "Attempt to destroy undead transport %p!\n", transport);
166 	sctp_packet_free(&transport->packet);
168 	if (transport->asoc)
169 		sctp_association_put(transport->asoc);
171 	call_rcu(&transport->rcu, sctp_transport_destroy_rcu);
177 void sctp_transport_reset_t3_rtx(struct sctp_transport *transport)
187 	if (!timer_pending(&transport->T3_rtx_timer))
188 		if (!mod_timer(&transport->T3_rtx_timer,
189 			       jiffies + transport->rto))
190 			sctp_transport_hold(transport);
193 void sctp_transport_reset_hb_timer(struct sctp_transport *transport)
198 	expires = jiffies + sctp_transport_timeout(transport);
199 	if (!mod_timer(&transport->hb_timer,
200 		       expires + get_random_u32_below(transport->rto)))
201 		sctp_transport_hold(transport);
204 void sctp_transport_reset_reconf_timer(struct sctp_transport *transport)
206 	if (!timer_pending(&transport->reconf_timer))
207 		if (!mod_timer(&transport->reconf_timer,
208 			       jiffies + transport->rto))
209 			sctp_transport_hold(transport);
212 void sctp_transport_reset_probe_timer(struct sctp_transport *transport)
214 	if (!mod_timer(&transport->probe_timer,
215 		       jiffies + transport->probe_interval))
216 		sctp_transport_hold(transport);
219 void sctp_transport_reset_raise_timer(struct sctp_transport *transport)
221 	if (!mod_timer(&transport->probe_timer,
222 		       jiffies + transport->probe_interval * 30))
223 		sctp_transport_hold(transport);
226 /* This transport has been assigned to an association.
230 void sctp_transport_set_owner(struct sctp_transport *transport,
233 	transport->asoc = asoc;
237 /* Initialize the pmtu of a transport. */
238 void sctp_transport_pmtu(struct sctp_transport *transport, struct sock *sk)
241 	if (!transport->dst || transport->dst->obsolete) {
242 		sctp_transport_dst_release(transport);
243 		transport->af_specific->get_dst(transport, &transport->saddr,
244 						&transport->fl, sk);
247 	if (transport->param_flags & SPP_PMTUD_DISABLE) {
248 		struct sctp_association *asoc = transport->asoc;
250 		if (!transport->pathmtu && asoc && asoc->pathmtu)
251 			transport->pathmtu = asoc->pathmtu;
252 		if (transport->pathmtu)
256 	if (transport->dst)
257 		transport->pathmtu = sctp_dst_mtu(transport->dst);
259 		transport->pathmtu = SCTP_DEFAULT_MAXSEGMENT;
261 	sctp_transport_pl_update(transport);
303 	pr_debug("%s: PLPMTUD: transport: %p, state: %d, pmtu: %d, size: %d, high: %d\n",
310 	pr_debug("%s: PLPMTUD: transport: %p, state: %d, pmtu: %d, size: %d, high: %d\n",
355 	pr_debug("%s: PLPMTUD: transport: %p, state: %d, pmtu: %d, size: %d, ptb: %d\n",
445 /* Caches the dst entry and source address for a transport's destination
448 void sctp_transport_route(struct sctp_transport *transport,
451 	struct sctp_association *asoc = transport->asoc;
452 	struct sctp_af *af = transport->af_specific;
454 	sctp_transport_dst_release(transport);
455 	af->get_dst(transport, saddr, &transport->fl, sctp_opt2sk(opt));
458 		memcpy(&transport->saddr, saddr, sizeof(union sctp_addr));
460 		af->get_saddr(opt, transport, &transport->fl);
462 	sctp_transport_pmtu(transport, sctp_opt2sk(opt));
464 	/* Initialize sk->sk_rcv_saddr, if the transport is the
467 	if (transport->dst && asoc &&
468 	    (!asoc->peer.primary_path || transport == asoc->peer.active_path))
469 		opt->pf->to_sk_saddr(&transport->saddr, asoc->base.sk);
472 /* Hold a reference to a transport.  */
473 int sctp_transport_hold(struct sctp_transport *transport)
475 	return refcount_inc_not_zero(&transport->refcnt);
478 /* Release a reference to a transport and clean up
481 void sctp_transport_put(struct sctp_transport *transport)
483 	if (refcount_dec_and_test(&transport->refcnt))
484 		sctp_transport_destroy(transport);
487 /* Update transport's RTO based on the newly calculated RTT. */
492 		pr_debug("%s: rto_pending not set on transport %p!\n", __func__, tp);
548 	pr_debug("%s: transport:%p, rtt:%d, srtt:%d rttvar:%d, rto:%ld\n",
552 /* This routine updates the transport's cwnd and partial_bytes_acked
555 void sctp_transport_raise_cwnd(struct sctp_transport *transport,
558 	struct sctp_association *asoc = transport->asoc;
561 	cwnd = transport->cwnd;
562 	flight_size = transport->flight_size;
569 	ssthresh = transport->ssthresh;
570 	pba = transport->partial_bytes_acked;
571 	pmtu = transport->asoc->pathmtu;
604 		pr_debug("%s: slow start: transport:%p, bytes_acked:%d, "
606 			 __func__, transport, bytes_acked, cwnd, ssthresh,
639 		pr_debug("%s: congestion avoidance: transport:%p, "
642 			 transport, bytes_acked, cwnd, ssthresh,
646 	transport->cwnd = cwnd;
647 	transport->partial_bytes_acked = pba;
650 /* This routine is used to lower the transport's cwnd when congestion is
653 void sctp_transport_lower_cwnd(struct sctp_transport *transport,
656 	struct sctp_association *asoc = transport->asoc;
667 		transport->ssthresh = max(transport->cwnd/2,
669 		transport->cwnd = asoc->pathmtu;
695 		transport->ssthresh = max(transport->cwnd/2,
697 		transport->cwnd = transport->ssthresh;
713 		if (time_after(jiffies, transport->last_time_ecne_reduced +
714 					transport->rtt)) {
715 			transport->ssthresh = max(transport->cwnd/2,
717 			transport->cwnd = transport->ssthresh;
718 			transport->last_time_ecne_reduced = jiffies;
725 		 * transport address, the cwnd of the transport address
731 		transport->cwnd = max(transport->cwnd/2,
734 		transport->ssthresh = transport->cwnd;
738 	transport->partial_bytes_acked = 0;
740 	pr_debug("%s: transport:%p, reason:%d, cwnd:%d, ssthresh:%d\n",
741 		 __func__, transport, reason, transport->cwnd,
742 		 transport->ssthresh);
782 /* What is the next timeout value for this transport? */
795 /* Reset transport variables to their initial values */
828 /* Schedule retransmission on the given transport */

Indexes created Sat May 04 09:44:38 MDT 2024