MFC r294057:

Fix a bug in INIT handling on accepted 1-to-1 style sockets when the
listener is closed.
This fix allows the following packetdrill test to pass:
// Setup a connected, blocking 1-to-1 style socket
+0.0 socket(..., SOCK_STREAM, IPPROTO_SCTP) = 3
// Check the handshake with en empty(!) cookie
+0.0 bind(3, ..., ...) = 0
+0.0 listen(3, 1) = 0
+0.0 < sctp: INIT[flgs=0, tag=1, a_rwnd=1500, os=1, is=1, tsn=1]
+0.0 > sctp: INIT_ACK[flgs=0, tag=2, a_rwnd=..., os=..., is=..., tsn=1, ...]
+0.0 < sctp: COOKIE_ECHO[flgs=0, len=..., val=...]
+0.0 > sctp: COOKIE_ACK[flgs=0]
+0.0 accept(3, ..., ...) = 4
+0.0 close(3) = 0
// Inject an INIT chunk and expect an INIT-ACK
+0.0 < sctp: INIT[flgs=0, tag=3, a_rwnd=1500, os=1, is=1, tsn=1]
+0.0 > sctp: INIT_ACK[flgs=0, tag=..., a_rwnd=..., os=..., is=..., tsn=..., ...]

1 files changed, 6 insertions, 2 deletions

diff --git a/sys/netinet/sctp_pcb.c b/sys/netinet/sctp_pcb.c
index 303a944..39872e4 100644
--- a/sys/netinet/sctp_pcb.c
+++ b/sys/netinet/sctp_pcb.c
@@ -2269,8 +2269,12 @@ sctp_findassociation_addr(struct mbuf *m, int offset,
 		}
 	}
 	find_tcp_pool = 0;
-	if ((ch->chunk_type != SCTP_INITIATION) &&
-	    (ch->chunk_type != SCTP_INITIATION_ACK) &&
+	/*
+	 * Don't consider INIT chunks since that breaks 1-to-1 sockets: When
+	 * a server closes the listener, incoming INIT chunks are not
+	 * responsed by an INIT-ACK chunk.
+	 */
+	if ((ch->chunk_type != SCTP_INITIATION_ACK) &&
 	    (ch->chunk_type != SCTP_COOKIE_ACK) &&
 	    (ch->chunk_type != SCTP_COOKIE_ECHO)) {
 		/* Other chunk types go to the tcp pool. */