This patch is to implement Receiver-Side Procedures for the SSN/TSN
Reset Request Parameter described in section 6.2.4.
The process is kinda complicate, it's wonth having comments from
section 6.2.4 in the codes.
Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx>
---
include/net/sctp/sm.h | 4 +++
net/sctp/stream.c | 76 +++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 80 insertions(+)
diff --git a/include/net/sctp/sm.h b/include/net/sctp/sm.h
index 180d017..e1b2509 100644
--- a/include/net/sctp/sm.h
+++ b/include/net/sctp/sm.h
@@ -289,6 +289,10 @@ struct sctp_chunk *sctp_process_strreset_inreq(
struct sctp_association *asoc,
union sctp_params param,
struct sctp_ulpevent **evp);
+struct sctp_chunk *sctp_process_strreset_tsnreq(
+ struct sctp_association *asoc,
+ union sctp_params param,
+ struct sctp_ulpevent **evp);
/* Prototypes for statetable processing. */
diff --git a/net/sctp/stream.c b/net/sctp/stream.c
index 3053d06..fce4317 100644
--- a/net/sctp/stream.c
+++ b/net/sctp/stream.c
@@ -207,3 +207,79 @@ struct sctp_chunk *sctp_process_strreset_inreq(
return chunk;
}
+
+struct sctp_chunk *sctp_process_strreset_tsnreq(
+ struct sctp_association *asoc,
+ union sctp_params param,
+ struct sctp_ulpevent **evp)
+{
+ struct sctp_strreset_tsnreq *tsnreq = param.v;
+ __u32 request_seq, initial_tsn, max_tsn_seen;
+ __u32 result = SCTP_STRRESET_DENIED;
+ __u16 i;
+
+ request_seq = ntohl(tsnreq->request_seq);
+ if (request_seq > asoc->strreset_inseq) {
+ result = SCTP_STRRESET_ERR_BAD_SEQNO;
+ goto out;
+ } else if (request_seq == asoc->strreset_inseq) {
+ asoc->strreset_inseq++;
+ }
+
+ if (!(asoc->strreset_enable & SCTP_ENABLE_RESET_ASSOC_REQ))
+ goto out;
+
+ if (asoc->strreset_outstanding) {
+ result = SCTP_STRRESET_ERR_IN_PROGRESS;
+ goto out;
+ }
+
+ /* G3: The same processing as though a SACK chunk with no gap report
+ * and a cumulative TSN ACK of the Sender's Next TSN minus 1 were
+ * received MUST be performed.
+ */
+ max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
+ sctp_ulpq_reasm_flushtsn(&asoc->ulpq, max_tsn_seen);
+ sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
+
+ /* G1: Compute an appropriate value for the Receiver's Next TSN -- the
+ * TSN that the peer should use to send the next DATA chunk. The
+ * value SHOULD be the smallest TSN not acknowledged by the
+ * receiver of the request plus 2^31.
+ */
+ initial_tsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map) + (1 << 31);
+ sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
+ initial_tsn, GFP_ATOMIC);
+
+ /* G4: The same processing as though a FWD-TSN chunk (as defined in
+ * [RFC3758]) with all streams affected and a new cumulative TSN
+ * ACK of the Receiver's Next TSN minus 1 were received MUST be
+ * performed.
+ */
+ sctp_outq_free(&asoc->outqueue);
+
+ /* G2: Compute an appropriate value for the local endpoint's next TSN,
+ * i.e., the next TSN assigned by the receiver of the SSN/TSN reset
+ * chunk. The value SHOULD be the highest TSN sent by the receiver
+ * of the request plus 1.
+ */
+ asoc->ctsn_ack_point = asoc->next_tsn - 1;
+ asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
+
+ /* G5: The next expected and outgoing SSNs MUST be reset to 0 for all
+ * incoming and outgoing streams.
+ */
+ for (i = 0; i < asoc->streamoutcnt; i++)
+ asoc->streamout[i].ssn = 0;
+ for (i = 0; i < asoc->streamincnt; i++)
+ asoc->streamin[i].ssn = 0;
+
+ result = SCTP_STRRESET_PERFORMED;
+
+ *evp = sctp_ulpevent_make_assoc_reset_event(asoc,
+ 0, initial_tsn, asoc->next_tsn, GFP_ATOMIC);
+
+out:
+ return sctp_make_strreset_tsnresp(asoc, result, request_seq,
+ asoc->next_tsn, initial_tsn);
+}
--
2.1.0
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