sctp: handle ootb packet in chunk order as defined

Changed the order of processing SHUTDOWN ACK and COOKIE ACK
refer to section 8.4:Handle "Out of the Blue" Packets.

SHUTDOWN ACK chunk should be processed before processing
"Stale Cookie" ERROR or a COOKIE ACK.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 21 insertions, 15 deletions

diff --git a/net/sctp/input.c b/net/sctp/input.c
index 30cec7732e80..3a8eb79eb78b 100644
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -661,7 +661,6 @@ static int sctp_rcv_ootb(struct sk_buff *skb)
 {
         sctp_chunkhdr_t *ch;
         __u8 *ch_end;
-        sctp_errhdr_t *err;
 
         ch = (sctp_chunkhdr_t *) skb->data;
 
@@ -697,20 +696,6 @@ static int sctp_rcv_ootb(struct sk_buff *skb)
                 if (SCTP_CID_INIT == ch->type && (void *)ch != skb->data)
                         goto discard;
 
-                /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR
-                 * or a COOKIE ACK the SCTP Packet should be silently
-                 * discarded.
-                 */
-                if (SCTP_CID_COOKIE_ACK == ch->type)
-                        goto discard;
-
-                if (SCTP_CID_ERROR == ch->type) {
-                        sctp_walk_errors(err, ch) {
-                                if (SCTP_ERROR_STALE_COOKIE == err->cause)
-                                        goto discard;
-                        }
-                }
-
                 ch = (sctp_chunkhdr_t *) ch_end;
         } while (ch_end < skb_tail_pointer(skb));
 
diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index 194d5ecab5c3..ad3b43bb75cc 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -3332,8 +3332,10 @@ sctp_disposition_t sctp_sf_ootb(const struct sctp_endpoint *ep,
         struct sctp_chunk *chunk = arg;
         struct sk_buff *skb = chunk->skb;
         sctp_chunkhdr_t *ch;
+        sctp_errhdr_t *err;
         __u8 *ch_end;
         int ootb_shut_ack = 0;
+        int ootb_cookie_ack = 0;
 
         SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
 
@@ -3358,6 +3360,23 @@ sctp_disposition_t sctp_sf_ootb(const struct sctp_endpoint *ep,
                 if (SCTP_CID_ABORT == ch->type)
                         return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
 
+                /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR
+                 * or a COOKIE ACK the SCTP Packet should be silently
+                 * discarded.
+                 */
+
+                if (SCTP_CID_COOKIE_ACK == ch->type)
+                        ootb_cookie_ack = 1;
+
+                if (SCTP_CID_ERROR == ch->type) {
+                        sctp_walk_errors(err, ch) {
+                                if (SCTP_ERROR_STALE_COOKIE == err->cause) {
+                                        ootb_cookie_ack = 1;
+                                        break;
+                                }
+                        }
+                }
+
                 /* Report violation if chunk len overflows */
                 ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
                 if (ch_end > skb_tail_pointer(skb))
@@ -3369,6 +3388,8 @@ sctp_disposition_t sctp_sf_ootb(const struct sctp_endpoint *ep,
 
         if (ootb_shut_ack)
                 return sctp_sf_shut_8_4_5(ep, asoc, type, arg, commands);
+        else if (ootb_cookie_ack)
+                return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
         else
                 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
 }