sctp: implement report_ftsn for sctp_stream_interleave

report_ftsn is added as a member of sctp_stream_interleave, used to
skip tsn from tsnmap, remove old events from reasm or lobby queue,
and abort pd for data or idata, called for SCTP_CMD_REPORT_FWDTSN
cmd and asoc reset.

sctp_report_iftsn works for ifwdtsn, and sctp_report_fwdtsn works
for fwdtsn. Note that sctp_report_iftsn doesn't do asoc abort_pd,
as stream abort_pd will be done when handling ifwdtsn. But when
ftsn is equal with ftsn, which means asoc reset, asoc abort_pd has
to be done.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo R. Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/sctp/stream_interleave.h

@@ -51,6 +51,7 @@ struct sctp_stream_interleave {
 	/* (I-)FORWARD-TSN process */
 	void	(*generate_ftsn)(struct sctp_outq *q, __u32 ctsn);
 	bool	(*validate_ftsn)(struct sctp_chunk *chunk);
+	void	(*report_ftsn)(struct sctp_ulpq *ulpq, __u32 ftsn);
 };
 
 void sctp_stream_interleave_init(struct sctp_stream *stream);

net/sctp/sm_sideeffect.c

@@ -1368,14 +1368,7 @@ static int sctp_cmd_interpreter(enum sctp_event event_type,
 			break;
 
 		case SCTP_CMD_REPORT_FWDTSN:
-			/* Move the Cumulattive TSN Ack ahead. */
-			sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
-
-			/* purge the fragmentation queue */
-			sctp_ulpq_reasm_flushtsn(&asoc->ulpq, cmd->obj.u32);
-
-			/* Abort any in progress partial delivery. */
-			sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
+			asoc->stream.si->report_ftsn(&asoc->ulpq, cmd->obj.u32);
 			break;
 
 		case SCTP_CMD_PROCESS_FWDTSN:

net/sctp/stream.c

@@ -754,8 +754,7 @@ struct sctp_chunk *sctp_process_strreset_tsnreq(
 	 *     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);
+	asoc->stream.si->report_ftsn(&asoc->ulpq, max_tsn_seen);
 
 	/* 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
@@ -1024,8 +1023,7 @@ struct sctp_chunk *sctp_process_strreset_resp(
 						&asoc->peer.tsn_map);
 			LIST_HEAD(temp);
 
-			sctp_ulpq_reasm_flushtsn(&asoc->ulpq, mtsn);
-			sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
+			asoc->stream.si->report_ftsn(&asoc->ulpq, mtsn);
 
 			sctp_tsnmap_init(&asoc->peer.tsn_map,
 					 SCTP_TSN_MAP_INITIAL,

net/sctp/stream_interleave.c

@@ -1193,6 +1193,52 @@ static bool sctp_validate_iftsn(struct sctp_chunk *chunk)
 	return true;
 }
 
+static void sctp_report_fwdtsn(struct sctp_ulpq *ulpq, __u32 ftsn)
+{
+	/* Move the Cumulattive TSN Ack ahead. */
+	sctp_tsnmap_skip(&ulpq->asoc->peer.tsn_map, ftsn);
+	/* purge the fragmentation queue */
+	sctp_ulpq_reasm_flushtsn(ulpq, ftsn);
+	/* Abort any in progress partial delivery. */
+	sctp_ulpq_abort_pd(ulpq, GFP_ATOMIC);
+}
+
+static void sctp_intl_reasm_flushtsn(struct sctp_ulpq *ulpq, __u32 ftsn)
+{
+	struct sk_buff *pos, *tmp;
+
+	skb_queue_walk_safe(&ulpq->reasm, pos, tmp) {
+		struct sctp_ulpevent *event = sctp_skb2event(pos);
+		__u32 tsn = event->tsn;
+
+		if (TSN_lte(tsn, ftsn)) {
+			__skb_unlink(pos, &ulpq->reasm);
+			sctp_ulpevent_free(event);
+		}
+	}
+
+	skb_queue_walk_safe(&ulpq->reasm_uo, pos, tmp) {
+		struct sctp_ulpevent *event = sctp_skb2event(pos);
+		__u32 tsn = event->tsn;
+
+		if (TSN_lte(tsn, ftsn)) {
+			__skb_unlink(pos, &ulpq->reasm_uo);
+			sctp_ulpevent_free(event);
+		}
+	}
+}
+
+static void sctp_report_iftsn(struct sctp_ulpq *ulpq, __u32 ftsn)
+{
+	/* Move the Cumulattive TSN Ack ahead. */
+	sctp_tsnmap_skip(&ulpq->asoc->peer.tsn_map, ftsn);
+	/* purge the fragmentation queue */
+	sctp_intl_reasm_flushtsn(ulpq, ftsn);
+	/* abort only when it's for all data */
+	if (ftsn == sctp_tsnmap_get_max_tsn_seen(&ulpq->asoc->peer.tsn_map))
+		sctp_intl_abort_pd(ulpq, GFP_ATOMIC);
+}
+
 static struct sctp_stream_interleave sctp_stream_interleave_0 = {
 	.data_chunk_len		= sizeof(struct sctp_data_chunk),
 	.ftsn_chunk_len		= sizeof(struct sctp_fwdtsn_chunk),
@@ -1208,6 +1254,7 @@ static struct sctp_stream_interleave sctp_stream_interleave_0 = {
 	/* FORWARD-TSN process functions */
 	.generate_ftsn		= sctp_generate_fwdtsn,
 	.validate_ftsn		= sctp_validate_fwdtsn,
+	.report_ftsn		= sctp_report_fwdtsn,
 };
 
 static struct sctp_stream_interleave sctp_stream_interleave_1 = {
@@ -1225,6 +1272,7 @@ static struct sctp_stream_interleave sctp_stream_interleave_1 = {
 	/* I-FORWARD-TSN process functions */
 	.generate_ftsn		= sctp_generate_iftsn,
 	.validate_ftsn		= sctp_validate_iftsn,
+	.report_ftsn		= sctp_report_iftsn,
 };
 
 void sctp_stream_interleave_init(struct sctp_stream *stream)