[SCTP]: Verify all the paths to a peer via heartbeat before using them.

This patch implements Path Initialization procedure as described in
Sec 2.36 of RFC4460.

Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index 5f69158..268f2e1 100644 (file)
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -445,6 +445,7 @@ typedef struct sctp_sender_hb_info {
        struct sctp_paramhdr param_hdr;
        union sctp_addr daddr;
        unsigned long sent_at;
+       __u64 hb_nonce;
 } __attribute__((packed)) sctp_sender_hb_info_t;
 
 /*
@@ -984,6 +985,9 @@ struct sctp_transport {
                 */
                char cacc_saw_newack;
        } cacc;
+
+       /* 64-bit random number sent with heartbeat. */
+       __u64 hb_nonce;
 };
 
 struct sctp_transport *sctp_transport_new(const union sctp_addr *,

diff --git a/include/net/sctp/user.h b/include/net/sctp/user.h
index 8a6bef6..1b7aae6 100644 (file)
--- a/include/net/sctp/user.h
+++ b/include/net/sctp/user.h
@@ -560,9 +560,18 @@ struct sctp_paddrinfo {
 } __attribute__((packed, aligned(4)));
 
 /* Peer addresses's state. */
+/* UNKNOWN: Peer address passed by the upper layer in sendmsg or connect[x]
+ * calls.
+ * UNCONFIRMED: Peer address received in INIT/INIT-ACK address parameters.
+ *              Not yet confirmed by a heartbeat and not available for data
+ *             transfers.
+ * ACTIVE : Peer address confirmed, active and available for data transfers.
+ * INACTIVE: Peer address inactive and not available for data transfers.
+ */
 enum sctp_spinfo_state {
        SCTP_INACTIVE,
        SCTP_ACTIVE,
+       SCTP_UNCONFIRMED,
        SCTP_UNKNOWN = 0xffff  /* Value used for transport state unknown */
 };
 

diff --git a/net/sctp/associola.c b/net/sctp/associola.c
index 9d05e13..27329ce 100644 (file)
--- a/net/sctp/associola.c
+++ b/net/sctp/associola.c
@@ -441,7 +441,8 @@ void sctp_assoc_set_primary(struct sctp_association *asoc,
        /* If the primary path is changing, assume that the
         * user wants to use this new path.
         */
-       if (transport->state != SCTP_INACTIVE)
+       if ((transport->state == SCTP_ACTIVE) ||
+           (transport->state == SCTP_UNKNOWN))
                asoc->peer.active_path = transport;
 
        /*
@@ -532,11 +533,11 @@ struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
        port = addr->v4.sin_port;
 
        SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_add_peer:association %p addr: ",
-                                " port: %d state:%s\n",
+                                " port: %d state:%d\n",
                                 asoc,
                                 addr,
                                 addr->v4.sin_port,
-                                peer_state == SCTP_UNKNOWN?"UNKNOWN":"ACTIVE");
+                                peer_state);
 
        /* Set the port if it has not been set yet.  */
        if (0 == asoc->peer.port)
@@ -545,9 +546,12 @@ struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
        /* Check to see if this is a duplicate. */
        peer = sctp_assoc_lookup_paddr(asoc, addr);
        if (peer) {
-               if (peer_state == SCTP_ACTIVE &&
-                   peer->state == SCTP_UNKNOWN)
-                    peer->state = SCTP_ACTIVE;
+               if (peer->state == SCTP_UNKNOWN) {
+                       if (peer_state == SCTP_ACTIVE)
+                               peer->state = SCTP_ACTIVE;
+                       if (peer_state == SCTP_UNCONFIRMED)
+                               peer->state = SCTP_UNCONFIRMED;
+               }
                return peer;
        }
 
@@ -739,7 +743,8 @@ void sctp_assoc_control_transport(struct sctp_association *asoc,
        list_for_each(pos, &asoc->peer.transport_addr_list) {
                t = list_entry(pos, struct sctp_transport, transports);
 
-               if (t->state == SCTP_INACTIVE)
+               if ((t->state == SCTP_INACTIVE) ||
+                   (t->state == SCTP_UNCONFIRMED))
                        continue;
                if (!first || t->last_time_heard > first->last_time_heard) {
                        second = first;
@@ -759,7 +764,8 @@ void sctp_assoc_control_transport(struct sctp_association *asoc,
         * [If the primary is active but not most recent, bump the most
         * recently used transport.]
         */
-       if (asoc->peer.primary_path->state != SCTP_INACTIVE &&
+       if (((asoc->peer.primary_path->state == SCTP_ACTIVE) ||
+            (asoc->peer.primary_path->state == SCTP_UNKNOWN)) &&
            first != asoc->peer.primary_path) {
                second = first;
                first = asoc->peer.primary_path;
@@ -1054,7 +1060,7 @@ void sctp_assoc_update(struct sctp_association *asoc,
                                           transports);
                        if (!sctp_assoc_lookup_paddr(asoc, &trans->ipaddr))
                                sctp_assoc_add_peer(asoc, &trans->ipaddr,
-                                                   GFP_ATOMIC, SCTP_ACTIVE);
+                                                   GFP_ATOMIC, trans->state);
                }
 
                asoc->ctsn_ack_point = asoc->next_tsn - 1;
@@ -1094,7 +1100,8 @@ void sctp_assoc_update_retran_path(struct sctp_association *asoc)
 
                /* Try to find an active transport. */
 
-               if (t->state != SCTP_INACTIVE) {
+               if ((t->state == SCTP_ACTIVE) ||
+                   (t->state == SCTP_UNKNOWN)) {
                        break;
                } else {
                        /* Keep track of the next transport in case

diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c
index e5faa35..30b710c 100644 (file)
--- a/net/sctp/outqueue.c
+++ b/net/sctp/outqueue.c
@@ -691,7 +691,8 @@ int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout)
 
                if (!new_transport) {
                        new_transport = asoc->peer.active_path;
-               } else if (new_transport->state == SCTP_INACTIVE) {
+               } else if ((new_transport->state == SCTP_INACTIVE) ||
+                          (new_transport->state == SCTP_UNCONFIRMED)) {
                        /* If the chunk is Heartbeat or Heartbeat Ack,
                         * send it to chunk->transport, even if it's
                         * inactive.
@@ -848,7 +849,8 @@ int sctp_outq_flush(struct sctp_outq *q, int rtx_timeout)
                         */
                        new_transport = chunk->transport;
                        if (!new_transport ||
-                           new_transport->state == SCTP_INACTIVE)
+                           ((new_transport->state == SCTP_INACTIVE) ||
+                            (new_transport->state == SCTP_UNCONFIRMED)))
                                new_transport = asoc->peer.active_path;
 
                        /* Change packets if necessary.  */
@@ -1464,7 +1466,8 @@ static void sctp_check_transmitted(struct sctp_outq *q,
                        /* Mark the destination transport address as
                         * active if it is not so marked.
                         */
-                       if (transport->state == SCTP_INACTIVE) {
+                       if ((transport->state == SCTP_INACTIVE) ||
+                           (transport->state == SCTP_UNCONFIRMED)) {
                                sctp_assoc_control_transport(
                                        transport->asoc,
                                        transport,

diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index 2a87736..8134e8b 100644 (file)
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -2017,7 +2017,7 @@ static int sctp_process_param(struct sctp_association *asoc,
                af->from_addr_param(&addr, param.addr, asoc->peer.port, 0);
                scope = sctp_scope(peer_addr);
                if (sctp_in_scope(&addr, scope))
-                       if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_ACTIVE))
+                       if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED))
                                return 0;
                break;
 
@@ -2418,7 +2418,7 @@ static __u16 sctp_process_asconf_param(struct sctp_association *asoc,
                 * Due to Resource Shortage'.
                 */
 
-               peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_ACTIVE);
+               peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED);
                if (!peer)
                        return SCTP_ERROR_RSRC_LOW;
 

diff --git a/net/sctp/sm_sideeffect.c b/net/sctp/sm_sideeffect.c
index c5beb2a..9c10bde 100644 (file)
--- a/net/sctp/sm_sideeffect.c
+++ b/net/sctp/sm_sideeffect.c
@@ -430,7 +430,11 @@ static void sctp_do_8_2_transport_strike(struct sctp_association *asoc,
        /* The check for association's overall error counter exceeding the
         * threshold is done in the state function.
         */
-       asoc->overall_error_count++;
+       /* When probing UNCONFIRMED addresses, the association overall
+        * error count is NOT incremented
+        */
+       if (transport->state != SCTP_UNCONFIRMED)
+               asoc->overall_error_count++;
 
        if (transport->state != SCTP_INACTIVE &&
            (transport->error_count++ >= transport->pathmaxrxt)) {
@@ -610,7 +614,7 @@ static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
        /* Mark the destination transport address as active if it is not so
         * marked.
         */
-       if (t->state == SCTP_INACTIVE)
+       if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED))
                sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
                                             SCTP_HEARTBEAT_SUCCESS);
 
@@ -620,6 +624,10 @@ static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
         */
        hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
        sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
+
+       /* Update the heartbeat timer.  */
+       if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
+               sctp_transport_hold(t);
 }
 
 /* Helper function to do a transport reset at the expiry of the hearbeat

diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index 9e58144..e8498dc 100644 (file)
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -846,6 +846,7 @@ static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep,
        hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t));
        hbinfo.daddr = transport->ipaddr;
        hbinfo.sent_at = jiffies;
+       hbinfo.hb_nonce = transport->hb_nonce;
 
        /* Send a heartbeat to our peer.  */
        paylen = sizeof(sctp_sender_hb_info_t);
@@ -1048,6 +1049,10 @@ sctp_disposition_t sctp_sf_backbeat_8_3(const struct sctp_endpoint *ep,
                return SCTP_DISPOSITION_DISCARD;
        }
 
+       /* Validate the 64-bit random nonce. */
+       if (hbinfo->hb_nonce != link->hb_nonce)
+               return SCTP_DISPOSITION_DISCARD;
+
        max_interval = link->hbinterval + link->rto;
 
        /* Check if the timestamp looks valid.  */

diff --git a/net/sctp/transport.c b/net/sctp/transport.c
index 160f62a..2763aa9 100644 (file)
--- a/net/sctp/transport.c
+++ b/net/sctp/transport.c
@@ -49,6 +49,7 @@
  */
 
 #include <linux/types.h>
+#include <linux/random.h>
 #include <net/sctp/sctp.h>
 #include <net/sctp/sm.h>
 
@@ -85,7 +86,6 @@ static struct sctp_transport *sctp_transport_init(struct sctp_transport *peer,
 
        peer->init_sent_count = 0;
 
-       peer->state = SCTP_ACTIVE;
        peer->param_flags = SPP_HB_DISABLE |
                            SPP_PMTUD_ENABLE |
                            SPP_SACKDELAY_ENABLE;
@@ -109,6 +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;
 
@@ -517,7 +520,9 @@ void sctp_transport_lower_cwnd(struct sctp_transport *transport,
 unsigned long sctp_transport_timeout(struct sctp_transport *t)
 {
        unsigned long timeout;
-       timeout = t->hbinterval + 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;
 }