[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>

1 files changed, 5 insertions, 0 deletions

diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index 9e58144f4851..e8498dce5335 100644
--- 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.  */