SCTP: Abort on COOKIE-ECHO if backlog is exceeded.

Currently we abort on the INIT chunk we our backlog is currenlty
exceeded.  Delay this about untill COOKIE-ECHO to give the user
time to accept the socket.  Also, make sure that we treat
sk_max_backlog of 0 as no connections allowed.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>

1 files changed, 10 insertions, 11 deletions

diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index 276e26d3d7da..177528ed3e1b 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -264,7 +264,6 @@ sctp_disposition_t sctp_sf_do_5_1B_init(const struct sctp_endpoint *ep,
         struct sctp_chunk *err_chunk;
         struct sctp_packet *packet;
         sctp_unrecognized_param_t *unk_param;
-        struct sock *sk;
         int len;
 
         /* 6.10 Bundling
@@ -285,16 +284,6 @@ sctp_disposition_t sctp_sf_do_5_1B_init(const struct sctp_endpoint *ep,
         if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
                 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
 
-        sk = ep->base.sk;
-        /* If the endpoint is not listening or if the number of associations
-         * on the TCP-style socket exceed the max backlog, respond with an
-         * ABORT.
-         */
-        if (!sctp_sstate(sk, LISTENING) ||
-            (sctp_style(sk, TCP) &&
-             sk_acceptq_is_full(sk)))
-                return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
-
         /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
          * Tag.
          */
@@ -590,6 +579,7 @@ sctp_disposition_t sctp_sf_do_5_1D_ce(const struct sctp_endpoint *ep,
         struct sctp_ulpevent *ev, *ai_ev = NULL;
         int error = 0;
         struct sctp_chunk *err_chk_p;
+        struct sock *sk;
 
         /* If the packet is an OOTB packet which is temporarily on the
          * control endpoint, respond with an ABORT.
@@ -605,6 +595,15 @@ sctp_disposition_t sctp_sf_do_5_1D_ce(const struct sctp_endpoint *ep,
         if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
                 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
 
+        /* If the endpoint is not listening or if the number of associations
+         * on the TCP-style socket exceed the max backlog, respond with an
+         * ABORT.
+         */
+        sk = ep->base.sk;
+        if (!sctp_sstate(sk, LISTENING) ||
+            (sctp_style(sk, TCP) && sk_acceptq_is_full(sk)))
+                return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
+
         /* "Decode" the chunk.  We have no optional parameters so we
          * are in good shape.
          */