[SCTP]: Fix protocol violation when receiving an error lenght INIT-ACK
When receiving an error length INIT-ACK during COOKIE-WAIT,
a 0-vtag ABORT will be responsed. This action violates the
protocol apparently. This patch achieves the following things.
1 If the INIT-ACK contains all the fixed parameters, use init-tag
recorded from INIT-ACK as vtag.
2 If the INIT-ACK doesn't contain all the fixed parameters,
just reflect its vtag.
Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index f2ed647..3ef9749 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -4144,6 +4144,24 @@
goto nomem;
if (asoc) {
+ /* Treat INIT-ACK as a special case during COOKIE-WAIT. */
+ if (chunk->chunk_hdr->type == SCTP_CID_INIT_ACK &&
+ !asoc->peer.i.init_tag) {
+ sctp_initack_chunk_t *initack;
+
+ initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
+ if (!sctp_chunk_length_valid(chunk,
+ sizeof(sctp_initack_chunk_t)))
+ abort->chunk_hdr->flags |= SCTP_CHUNK_FLAG_T;
+ else {
+ unsigned int inittag;
+
+ inittag = ntohl(initack->init_hdr.init_tag);
+ sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_INITTAG,
+ SCTP_U32(inittag));
+ }
+ }
+
sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);