[SCTP]: Correctly set IP id for SCTP traffic

Make SCTP 1-1 style and peeled-off associations behave like TCP when
setting IP id. In both cases, we set the inet_sk(sk)->daddr and initialize
inet_sk(sk)->id to a random value.

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

2 files changed, 10 insertions, 1 deletions

diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index fac7674438a4..5b4f82fd98f8 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -591,7 +591,7 @@ static struct sock *sctp_v4_create_accept_sk(struct sock *sk,
         newinet->dport = htons(asoc->peer.port);
         newinet->daddr = asoc->peer.primary_addr.v4.sin_addr.s_addr;
         newinet->pmtudisc = inet->pmtudisc;
-        newinet->id = 0;
+        newinet->id = asoc->next_tsn ^ jiffies;
 
         newinet->uc_ttl = -1;
         newinet->mc_loop = 1;
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 9f34dec6ff8e..935bc9187fd8 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -3372,6 +3372,7 @@ SCTP_STATIC int sctp_do_peeloff(struct sctp_association *asoc,
 {
         struct sock *sk = asoc->base.sk;
         struct socket *sock;
+        struct inet_sock *inetsk;
         int err = 0;
 
         /* An association cannot be branched off from an already peeled-off
@@ -3389,6 +3390,14 @@ SCTP_STATIC int sctp_do_peeloff(struct sctp_association *asoc,
          * asoc to the newsk.
          */
         sctp_sock_migrate(sk, sock->sk, asoc, SCTP_SOCKET_UDP_HIGH_BANDWIDTH);
+
+        /* Make peeled-off sockets more like 1-1 accepted sockets.
+         * Set the daddr and initialize id to something more random
+         */
+        inetsk = inet_sk(sock->sk);
+        inetsk->daddr = asoc->peer.primary_addr.v4.sin_addr.s_addr;
+        inetsk->id = asoc->next_tsn ^ jiffies;
+
         *sockp = sock;
 
         return err;