[SCTP] Update pmtu handling to be similar to tcp
[safe/jmp/linux-2.6] / net / sctp / transport.c
index 6bc2720..e14c271 100644 (file)
@@ -49,6 +49,7 @@
  */
 
 #include <linux/types.h>
+#include <linux/random.h>
 #include <net/sctp/sctp.h>
 #include <net/sctp/sm.h>
 
@@ -74,7 +75,7 @@ static struct sctp_transport *sctp_transport_init(struct sctp_transport *peer,
         * parameter 'RTO.Initial'.
         */
        peer->rtt = 0;
-       peer->rto = sctp_rto_initial;
+       peer->rto = msecs_to_jiffies(sctp_rto_initial);
        peer->rttvar = 0;
        peer->srtt = 0;
        peer->rto_pending = 0;
@@ -85,11 +86,13 @@ static struct sctp_transport *sctp_transport_init(struct sctp_transport *peer,
 
        peer->init_sent_count = 0;
 
-       peer->state = SCTP_ACTIVE;
-       peer->hb_allowed = 0;
+       peer->param_flags = SPP_HB_DISABLE |
+                           SPP_PMTUD_ENABLE |
+                           SPP_SACKDELAY_ENABLE;
+       peer->hbinterval  = 0;
 
        /* Initialize the default path max_retrans.  */
-       peer->max_retrans = sctp_max_retrans_path;
+       peer->pathmaxrxt  = sctp_max_retrans_path;
        peer->error_count = 0;
 
        INIT_LIST_HEAD(&peer->transmitted);
@@ -106,6 +109,9 @@ static struct sctp_transport *sctp_transport_init(struct sctp_transport *peer,
        peer->hb_timer.function = sctp_generate_heartbeat_event;
        peer->hb_timer.data = (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);
        peer->dead = 0;
 
@@ -124,9 +130,9 @@ static struct sctp_transport *sctp_transport_init(struct sctp_transport *peer,
 struct sctp_transport *sctp_transport_new(const union sctp_addr *addr,
                                          gfp_t gfp)
 {
-        struct sctp_transport *transport;
+       struct sctp_transport *transport;
 
-        transport = t_new(struct sctp_transport, gfp);
+       transport = t_new(struct sctp_transport, gfp);
        if (!transport)
                goto fail;
 
@@ -179,7 +185,7 @@ static void sctp_transport_destroy(struct sctp_transport *transport)
        if (transport->asoc)
                sctp_association_put(transport->asoc);
 
-        sctp_packet_free(&transport->packet);
+       sctp_packet_free(&transport->packet);
 
        dst_release(transport->dst);
        kfree(transport);
@@ -229,10 +235,51 @@ void sctp_transport_pmtu(struct sctp_transport *transport)
        dst = transport->af_specific->get_dst(NULL, &transport->ipaddr, NULL);
 
        if (dst) {
-               transport->pmtu = dst_mtu(dst);
+               transport->pathmtu = dst_mtu(dst);
                dst_release(dst);
        } else
-               transport->pmtu = SCTP_DEFAULT_MAXSEGMENT;
+               transport->pathmtu = SCTP_DEFAULT_MAXSEGMENT;
+}
+
+/* this is a complete rip-off from __sk_dst_check
+ * the cookie is always 0 since this is how it's used in the
+ * pmtu code
+ */
+static struct dst_entry *sctp_transport_dst_check(struct sctp_transport *t)
+{
+       struct dst_entry *dst = t->dst;
+
+       if (dst && dst->obsolete && dst->ops->check(dst, 0) == NULL) {
+               dst_release(t->dst);
+               t->dst = NULL;
+               return NULL;
+       }
+
+       return dst;
+}
+
+void sctp_transport_update_pmtu(struct sctp_transport *t, u32 pmtu)
+{
+       struct dst_entry *dst;
+
+       if (unlikely(pmtu < SCTP_DEFAULT_MINSEGMENT)) {
+               printk(KERN_WARNING "%s: Reported pmtu %d too low, "
+                      "using default minimum of %d\n",
+                      __FUNCTION__, pmtu,
+                      SCTP_DEFAULT_MINSEGMENT);
+               /* Use default minimum segment size and disable
+                * pmtu discovery on this transport.
+                */
+               t->pathmtu = SCTP_DEFAULT_MINSEGMENT;
+               t->param_flags = (t->param_flags & ~SPP_PMTUD) |
+                       SPP_PMTUD_DISABLE;
+       } 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
@@ -254,16 +301,20 @@ void sctp_transport_route(struct sctp_transport *transport,
                af->get_saddr(asoc, dst, daddr, &transport->saddr);
 
        transport->dst = dst;
+       if ((transport->param_flags & SPP_PMTUD_DISABLE) && transport->pathmtu) {
+               return;
+       }
        if (dst) {
-               transport->pmtu = dst_mtu(dst);
+               transport->pathmtu = dst_mtu(dst);
 
                /* Initialize sk->sk_rcv_saddr, if the transport is the
                 * association's active path for getsockname().
-                */ 
+                */
                if (asoc && (transport == asoc->peer.active_path))
-                       af->to_sk_saddr(&transport->saddr, asoc->base.sk);
+                       opt->pf->af->to_sk_saddr(&transport->saddr,
+                                                asoc->base.sk);
        } else
-               transport->pmtu = SCTP_DEFAULT_MAXSEGMENT;
+               transport->pathmtu = SCTP_DEFAULT_MAXSEGMENT;
 }
 
 /* Hold a reference to a transport.  */
@@ -343,7 +394,7 @@ void sctp_transport_update_rto(struct sctp_transport *tp, __u32 rtt)
        tp->rto_pending = 0;
 
        SCTP_DEBUG_PRINTK("%s: transport: %p, rtt: %d, srtt: %d "
-                         "rttvar: %d, rto: %d\n", __FUNCTION__,
+                         "rttvar: %d, rto: %ld\n", __FUNCTION__,
                          tp, rtt, tp->srtt, tp->rttvar, tp->rto);
 }
 
@@ -368,7 +419,7 @@ void sctp_transport_raise_cwnd(struct sctp_transport *transport,
 
        ssthresh = transport->ssthresh;
        pba = transport->partial_bytes_acked;
-       pmtu = transport->asoc->pmtu;
+       pmtu = transport->asoc->pathmtu;
 
        if (cwnd <= ssthresh) {
                /* RFC 2960 7.2.1, sctpimpguide-05 2.14.2 When cwnd is less
@@ -440,8 +491,8 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport,
                 *      partial_bytes_acked = 0
                 */
                transport->ssthresh = max(transport->cwnd/2,
-                                         4*transport->asoc->pmtu);
-               transport->cwnd = transport->asoc->pmtu;
+                                         4*transport->asoc->pathmtu);
+               transport->cwnd = transport->asoc->pathmtu;
                break;
 
        case SCTP_LOWER_CWND_FAST_RTX:
@@ -449,8 +500,8 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport,
                 * destination address(es) to which the missing DATA chunks
                 * were last sent, according to the formula described in
                 * Section 7.2.3.
-                *
-                * RFC 2960 7.2.3, sctpimpguide Upon detection of packet
+                *
+                * RFC 2960 7.2.3, sctpimpguide Upon detection of packet
                 * losses from SACK (see Section 7.2.4), An endpoint
                 * should do the following:
                 *      ssthresh = max(cwnd/2, 4*MTU)
@@ -458,7 +509,7 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport,
                 *      partial_bytes_acked = 0
                 */
                transport->ssthresh = max(transport->cwnd/2,
-                                         4*transport->asoc->pmtu);
+                                         4*transport->asoc->pathmtu);
                transport->cwnd = transport->ssthresh;
                break;
 
@@ -478,7 +529,7 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport,
                if ((jiffies - transport->last_time_ecne_reduced) >
                    transport->rtt) {
                        transport->ssthresh = max(transport->cwnd/2,
-                                                 4*transport->asoc->pmtu);
+                                                 4*transport->asoc->pathmtu);
                        transport->cwnd = transport->ssthresh;
                        transport->last_time_ecne_reduced = jiffies;
                }
@@ -495,9 +546,9 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport,
                 */
                if ((jiffies - transport->last_time_used) > transport->rto)
                        transport->cwnd = max(transport->cwnd/2,
-                                                4*transport->asoc->pmtu);
+                                                4*transport->asoc->pathmtu);
                break;
-       };
+       }
 
        transport->partial_bytes_acked = 0;
        SCTP_DEBUG_PRINTK("%s: transport: %p reason: %d cwnd: "
@@ -510,7 +561,41 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport,
 unsigned long sctp_transport_timeout(struct sctp_transport *t)
 {
        unsigned long timeout;
-       timeout = t->hb_interval + t->rto + sctp_jitter(t->rto);
+       timeout = t->rto + sctp_jitter(t->rto);
+       if (t->state != SCTP_UNCONFIRMED)
+               timeout += t->hbinterval;
        timeout += jiffies;
        return timeout;
 }
+
+/* Reset transport variables to their initial values */
+void sctp_transport_reset(struct sctp_transport *t)
+{
+       struct sctp_association *asoc = t->asoc;
+
+       /* RFC 2960 (bis), Section 5.2.4
+        * All the congestion control parameters (e.g., cwnd, ssthresh)
+        * related to this peer MUST be reset to their initial values
+        * (see Section 6.2.1)
+        */
+       t->cwnd = min(4*asoc->pathmtu, max_t(__u32, 2*asoc->pathmtu, 4380));
+       t->ssthresh = asoc->peer.i.a_rwnd;
+       t->rto = asoc->rto_initial;
+       t->rtt = 0;
+       t->srtt = 0;
+       t->rttvar = 0;
+
+       /* Reset these additional varibles so that we have a clean
+        * slate.
+        */
+       t->partial_bytes_acked = 0;
+       t->flight_size = 0;
+       t->error_count = 0;
+       t->rto_pending = 0;
+
+       /* Initialize the state information for SFR-CACC */
+       t->cacc.changeover_active = 0;
+       t->cacc.cycling_changeover = 0;
+       t->cacc.next_tsn_at_change = 0;
+       t->cacc.cacc_saw_newack = 0;
+}