This patch is to implement Receiver-Side Procedures for the Outgoing
SSN Reset Request Parameter described in rfc6525 section 5.2.2.
Note that some checks must be after request_seq check, as even those
checks fail, strreset_inseq still has to be increase by 1.
Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx>
---
include/net/sctp/sm.h | 6 +++
net/sctp/stream.c | 113 ++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 119 insertions(+)
diff --git a/include/net/sctp/sm.h b/include/net/sctp/sm.h
index 8a85dd7..c0f9bea 100644
--- a/include/net/sctp/sm.h
+++ b/include/net/sctp/sm.h
@@ -280,6 +280,12 @@ struct sctp_chunk *sctp_make_strreset_tsnresp(
void sctp_chunk_assign_tsn(struct sctp_chunk *);
void sctp_chunk_assign_ssn(struct sctp_chunk *);
+/* Prototypes for stream-processing functions. */
+struct sctp_chunk *sctp_process_strreset_outreq(
+ struct sctp_association *asoc,
+ union sctp_params param,
+ struct sctp_ulpevent **evp);
+
/* Prototypes for statetable processing. */
int sctp_do_sm(struct net *net, sctp_event_t event_type, sctp_subtype_t subtype,
diff --git a/net/sctp/stream.c b/net/sctp/stream.c
index eb02490..531fcc4 100644
--- a/net/sctp/stream.c
+++ b/net/sctp/stream.c
@@ -294,3 +294,116 @@ int sctp_send_add_streams(struct sctp_association *asoc,
out:
return retval;
}
+
+static sctp_paramhdr_t *sctp_chunk_lookup_strreset_param(
+ struct sctp_association *asoc, __u32 resp_seq)
+{
+ struct sctp_chunk *chunk = asoc->strreset_chunk;
+ struct sctp_reconf_chunk *hdr;
+ union sctp_params param;
+
+ if (ntohl(resp_seq) != asoc->strreset_outseq || !chunk)
+ return NULL;
+
+ hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr;
+ sctp_walk_params(param, hdr, params) {
+ /* sctp_strreset_tsnreq is actually the basic structure
+ * of all stream reconf params, so it's safe to use it
+ * to access request_seq.
+ */
+ struct sctp_strreset_tsnreq *req = param.v;
+
+ if (req->request_seq == resp_seq)
+ return param.v;
+ }
+
+ return NULL;
+}
+
+struct sctp_chunk *sctp_process_strreset_outreq(
+ struct sctp_association *asoc,
+ union sctp_params param,
+ struct sctp_ulpevent **evp)
+{
+ struct sctp_strreset_outreq *outreq = param.v;
+ struct sctp_stream *stream = asoc->stream;
+ __u16 i, nums, flags = 0, *str_p = NULL;
+ __u32 result = SCTP_STRRESET_DENIED;
+ __u32 request_seq;
+
+ request_seq = ntohl(outreq->request_seq);
+
+ if (ntohl(outreq->send_reset_at_tsn) >
+ sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map)) {
+ result = SCTP_STRRESET_IN_PROGRESS;
+ goto out;
+ }
+
+ if (request_seq > asoc->strreset_inseq) {
+ result = SCTP_STRRESET_ERR_BAD_SEQNO;
+ goto out;
+ } else if (request_seq == asoc->strreset_inseq) {
+ asoc->strreset_inseq++;
+ }
+
+ /* Check strreset_enable after inseq inc, as sender cannot tell
+ * the peer doesn't enable strreset after receiving response with
+ * result denied, as well as to keep consistent with bsd.
+ */
+ if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_STREAM_REQ))
+ goto out;
+
+ if (asoc->strreset_chunk) {
+ sctp_paramhdr_t *param_hdr;
+ struct sctp_transport *t;
+
+ param_hdr = sctp_chunk_lookup_strreset_param(
+ asoc, outreq->response_seq);
+ if (!param_hdr || param_hdr->type !=
+ SCTP_PARAM_RESET_IN_REQUEST) {
+ /* same process with outstanding isn't 0 */
+ result = SCTP_STRRESET_ERR_IN_PROGRESS;
+ goto out;
+ }
+
+ asoc->strreset_outstanding--;
+ asoc->strreset_outseq++;
+
+ if (!asoc->strreset_outstanding) {
+ t = asoc->strreset_chunk->transport;
+ if (del_timer(&t->reconf_timer))
+ sctp_transport_put(t);
+
+ sctp_chunk_put(asoc->strreset_chunk);
+ asoc->strreset_chunk = NULL;
+ }
+
+ flags = SCTP_STREAM_RESET_INCOMING_SSN;
+ }
+
+ nums = (ntohs(param.p->length) - sizeof(*outreq)) / 2;
+ if (nums) {
+ str_p = outreq->list_of_streams;
+ for (i = 0; i < nums; i++) {
+ if (ntohs(str_p[i]) >= stream->incnt) {
+ result = SCTP_STRRESET_ERR_WRONG_SSN;
+ goto out;
+ }
+ }
+
+ for (i = 0; i < nums; i++)
+ stream->in[ntohs(str_p[i])].ssn = 0;
+ } else {
+ for (i = 0; i < stream->incnt; i++)
+ stream->in[i].ssn = 0;
+ }
+
+ result = SCTP_STRRESET_PERFORMED;
+
+ *evp = sctp_ulpevent_make_stream_reset_event(asoc,
+ flags | SCTP_STREAM_RESET_OUTGOING_SSN, nums, str_p,
+ GFP_ATOMIC);
+
+out:
+ return sctp_make_strreset_resp(asoc, result, request_seq);
+}
--
2.1.0
--
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