[PATCH net-next 7/9] sctp: remove the unnecessary transport looking up from sctp_sendmsg

[Xin Long]

Now sctp_assoc_lookup_paddr can only be called only if daddr has
been set. But if daddr has been set, sctp_endpoint_lookup_assoc
would be done, where it could already have the transport.

So this unnecessary transport looking up should be removed, but
only reset transport as NULL when SCTP_ADDR_OVER is not set for
UDP type socket.

Signed-off-by: Xin Long <lucien....@gmail.com>
---
 net/sctp/socket.c | 24 ++++++------------------
 1 file changed, 6 insertions(+), 18 deletions(-)

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index bd1a657..4260310 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -1911,7 +1911,7 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr 
*msg, size_t msg_len)
 {
        struct sctp_endpoint *ep = sctp_sk(sk)->ep;
        struct sctp_association *new_asoc = NULL, *asoc = NULL;
-       struct sctp_transport *transport, *chunk_tp;
+       struct sctp_transport *transport = NULL;
        struct sctp_sndrcvinfo _sinfo, *sinfo;
        sctp_assoc_t associd = 0;
        struct sctp_cmsgs cmsgs = { NULL };
@@ -1966,29 +1966,17 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr 
*msg, size_t msg_len)
                new_asoc = asoc;
        }
 
+       if (!sctp_style(sk, TCP) && !(sinfo_flags & SCTP_ADDR_OVER))
+               transport = NULL;
+
        /* Update snd_info with the asoc */
        sctp_sendmsg_update_sinfo(asoc, sinfo, &cmsgs);
 
-       /* If an address is passed with the sendto/sendmsg call, it is used
-        * to override the primary destination address in the TCP model, or
-        * when SCTP_ADDR_OVER flag is set in the UDP model.
-        */
-       if ((sctp_style(sk, TCP) && daddr) ||
-           (sinfo_flags & SCTP_ADDR_OVER)) {
-               chunk_tp = sctp_assoc_lookup_paddr(asoc, daddr);
-               if (!chunk_tp) {
-                       err = -EINVAL;
-                       goto out_free;
-               }
-       } else
-               chunk_tp = NULL;
-
        /* Send msg to the asoc */
-       err = sctp_sendmsg_to_asoc(asoc, msg, msg_len, chunk_tp, sinfo);
-
-out_free:
+       err = sctp_sendmsg_to_asoc(asoc, msg, msg_len, transport, sinfo);
        if (err < 0 && err != -ESRCH && new_asoc)
                sctp_association_free(asoc);
+
 out_unlock:
        release_sock(sk);
 out_nounlock:
-- 
2.1.0