[PATCH net-next 7/8] sctp: update mid instead of ssn when doing stream and asoc reset

[Xin Long]

When using idata and doing stream and asoc reset, setting ssn with
0 could only clear the 1st 16 bits of mid.

So to make this work for both data and idata, it sets mid with 0
instead of ssn, and also mid_uo for unordered idata also need to
be cleared, as said in section 2.3.2 of RFC8260.

Signed-off-by: Xin Long <lucien....@gmail.com>
---
 net/sctp/stream.c | 40 +++++++++++++++++++++++++---------------
 1 file changed, 25 insertions(+), 15 deletions(-)

diff --git a/net/sctp/stream.c b/net/sctp/stream.c
index b3a9f37..06b644d 100644
--- a/net/sctp/stream.c
+++ b/net/sctp/stream.c
@@ -216,11 +216,13 @@ void sctp_stream_clear(struct sctp_stream *stream)
 {
        int i;
 
-       for (i = 0; i < stream->outcnt; i++)
-               stream->out[i].ssn = 0;
+       for (i = 0; i < stream->outcnt; i++) {
+               stream->out[i].mid = 0;
+               stream->out[i].mid_uo = 0;
+       }
 
        for (i = 0; i < stream->incnt; i++)
-               stream->in[i].ssn = 0;
+               stream->in[i].mid = 0;
 }
 
 void sctp_stream_update(struct sctp_stream *stream, struct sctp_stream *new)
@@ -607,10 +609,10 @@ struct sctp_chunk *sctp_process_strreset_outreq(
                }
 
                for (i = 0; i < nums; i++)
-                       stream->in[ntohs(str_p[i])].ssn = 0;
+                       stream->in[ntohs(str_p[i])].mid = 0;
        } else {
                for (i = 0; i < stream->incnt; i++)
-                       stream->in[i].ssn = 0;
+                       stream->in[i].mid = 0;
        }
 
        result = SCTP_STRRESET_PERFORMED;
@@ -783,10 +785,12 @@ struct sctp_chunk *sctp_process_strreset_tsnreq(
        /* G5:  The next expected and outgoing SSNs MUST be reset to 0 for all
         *      incoming and outgoing streams.
         */
-       for (i = 0; i < stream->outcnt; i++)
-               stream->out[i].ssn = 0;
+       for (i = 0; i < stream->outcnt; i++) {
+               stream->out[i].mid = 0;
+               stream->out[i].mid_uo = 0;
+       }
        for (i = 0; i < stream->incnt; i++)
-               stream->in[i].ssn = 0;
+               stream->in[i].mid = 0;
 
        result = SCTP_STRRESET_PERFORMED;
 
@@ -976,11 +980,15 @@ struct sctp_chunk *sctp_process_strreset_resp(
 
                if (result == SCTP_STRRESET_PERFORMED) {
                        if (nums) {
-                               for (i = 0; i < nums; i++)
-                                       stream->out[ntohs(str_p[i])].ssn = 0;
+                               for (i = 0; i < nums; i++) {
+                                       stream->out[ntohs(str_p[i])].mid = 0;
+                                       stream->out[ntohs(str_p[i])].mid_uo = 0;
+                               }
                        } else {
-                               for (i = 0; i < stream->outcnt; i++)
-                                       stream->out[i].ssn = 0;
+                               for (i = 0; i < stream->outcnt; i++) {
+                                       stream->out[i].mid = 0;
+                                       stream->out[i].mid_uo = 0;
+                               }
                        }
 
                        flags = SCTP_STREAM_RESET_OUTGOING_SSN;
@@ -1041,10 +1049,12 @@ struct sctp_chunk *sctp_process_strreset_resp(
                        asoc->ctsn_ack_point = asoc->next_tsn - 1;
                        asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
 
-                       for (i = 0; i < stream->outcnt; i++)
-                               stream->out[i].ssn = 0;
+                       for (i = 0; i < stream->outcnt; i++) {
+                               stream->out[i].mid = 0;
+                               stream->out[i].mid_uo = 0;
+                       }
                        for (i = 0; i < stream->incnt; i++)
-                               stream->in[i].ssn = 0;
+                               stream->in[i].mid = 0;
                }
 
                for (i = 0; i < stream->outcnt; i++)
-- 
2.1.0