Merge branch 'sctp-sender-side-stream-reconf-ssn-reset-request-chunk'

Xin Long says:

====================
sctp: add sender-side procedures for stream reconf ssn reset request chunk

Patch 6/6 is to implement sender-side procedures for the Outgoing
and Incoming SSN Reset Request Parameter described in rfc6525
section 5.1.2 and 5.1.3

Patches 1-5/6 are ahead of it to define some apis and asoc members
for it.

Note that with this patchset, asoc->reconf_enable has no chance yet to
be set, until the patch "sctp: add get and set sockopt for reconf_enable"
is applied in the future. As we can not just enable it when sctp is not
capable of processing reconf chunk yet.

v1->v2:
  - put these into a smaller group.
  - rename some temporary variables in the codes.
  - rename the titles of the commits and improve some changelogs.
v2->v3:
  - re-split the patchset and make sure it has no dead codes for review.
v3->v4:
  - move sctp_make_reconf() into patch 1/6 to avoid kbuild warning.
  - drop unused struct sctp_strreset_req.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/sctp.h

@@ -108,6 +108,7 @@ typedef enum {
 	/* Use hex, as defined in ADDIP sec. 3.1 */
 	SCTP_CID_ASCONF			= 0xC1,
 	SCTP_CID_ASCONF_ACK		= 0x80,
+	SCTP_CID_RECONF			= 0x82,
 } sctp_cid_t; /* enum */
 
 
@@ -199,6 +200,13 @@ typedef enum {
 	SCTP_PARAM_SUCCESS_REPORT	= cpu_to_be16(0xc005),
 	SCTP_PARAM_ADAPTATION_LAYER_IND = cpu_to_be16(0xc006),
 
+	/* RE-CONFIG. Section 4 */
+	SCTP_PARAM_RESET_OUT_REQUEST		= cpu_to_be16(0x000d),
+	SCTP_PARAM_RESET_IN_REQUEST		= cpu_to_be16(0x000e),
+	SCTP_PARAM_RESET_TSN_REQUEST		= cpu_to_be16(0x000f),
+	SCTP_PARAM_RESET_RESPONSE		= cpu_to_be16(0x0010),
+	SCTP_PARAM_RESET_ADD_OUT_STREAMS	= cpu_to_be16(0x0011),
+	SCTP_PARAM_RESET_ADD_IN_STREAMS		= cpu_to_be16(0x0012),
 } sctp_param_t; /* enum */
 
 
@@ -710,4 +718,23 @@ struct sctp_infox {
 	struct sctp_association *asoc;
 };
 
+struct sctp_reconf_chunk {
+	sctp_chunkhdr_t chunk_hdr;
+	__u8 params[0];
+} __packed;
+
+struct sctp_strreset_outreq {
+	sctp_paramhdr_t param_hdr;
+	__u32 request_seq;
+	__u32 response_seq;
+	__u32 send_reset_at_tsn;
+	__u16 list_of_streams[0];
+} __packed;
+
+struct sctp_strreset_inreq {
+	sctp_paramhdr_t param_hdr;
+	__u32 request_seq;
+	__u16 list_of_streams[0];
+} __packed;
+
 #endif /* __LINUX_SCTP_H__ */

include/net/netns/sctp.h

@@ -118,6 +118,9 @@ struct netns_sctp {
 	/* Flag to indicate if PR-SCTP is enabled. */
 	int prsctp_enable;
 
+	/* Flag to indicate if PR-CONFIG is enabled. */
+	int reconf_enable;
+
 	/* Flag to idicate if SCTP-AUTH is enabled */
 	int auth_enable;
 

include/net/sctp/constants.h

@@ -90,6 +90,7 @@ typedef enum {
 	SCTP_EVENT_TIMEOUT_T4_RTO,
 	SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD,
 	SCTP_EVENT_TIMEOUT_HEARTBEAT,
+	SCTP_EVENT_TIMEOUT_RECONF,
 	SCTP_EVENT_TIMEOUT_SACK,
 	SCTP_EVENT_TIMEOUT_AUTOCLOSE,
 } sctp_event_timeout_t;
@@ -113,9 +114,10 @@ typedef enum {
 	SCTP_PRIMITIVE_SEND,
 	SCTP_PRIMITIVE_REQUESTHEARTBEAT,
 	SCTP_PRIMITIVE_ASCONF,
+	SCTP_PRIMITIVE_RECONF,
 } sctp_event_primitive_t;
 
-#define SCTP_EVENT_PRIMITIVE_MAX	SCTP_PRIMITIVE_ASCONF
+#define SCTP_EVENT_PRIMITIVE_MAX	SCTP_PRIMITIVE_RECONF
 #define SCTP_NUM_PRIMITIVE_TYPES	(SCTP_EVENT_PRIMITIVE_MAX + 1)
 
 /* We define here a utility type for manipulating subtypes.

include/net/sctp/sctp.h

@@ -141,6 +141,8 @@ int sctp_primitive_ABORT(struct net *, struct sctp_association *, void *arg);
 int sctp_primitive_SEND(struct net *, struct sctp_association *, void *arg);
 int sctp_primitive_REQUESTHEARTBEAT(struct net *, struct sctp_association *, void *arg);
 int sctp_primitive_ASCONF(struct net *, struct sctp_association *, void *arg);
+int sctp_primitive_RECONF(struct net *net, struct sctp_association *asoc,
+			  void *arg);
 
 /*
  * sctp/input.c
@@ -191,6 +193,12 @@ void sctp_remaddr_proc_exit(struct net *net);
  */
 int sctp_offload_init(void);
 
+/*
+ * sctp/stream.c
+ */
+int sctp_send_reset_streams(struct sctp_association *asoc,
+			    struct sctp_reset_streams *params);
+
 /*
  * Module global variables
  */

include/net/sctp/sm.h

@@ -157,6 +157,7 @@ sctp_state_fn_t sctp_sf_error_shutdown;
 sctp_state_fn_t sctp_sf_ignore_primitive;
 sctp_state_fn_t sctp_sf_do_prm_requestheartbeat;
 sctp_state_fn_t sctp_sf_do_prm_asconf;
+sctp_state_fn_t sctp_sf_do_prm_reconf;
 
 /* Prototypes for other event state functions.  */
 sctp_state_fn_t sctp_sf_do_no_pending_tsn;
@@ -167,6 +168,7 @@ sctp_state_fn_t sctp_sf_cookie_wait_icmp_abort;
 
 /* Prototypes for timeout event state functions.  */
 sctp_state_fn_t sctp_sf_do_6_3_3_rtx;
+sctp_state_fn_t sctp_sf_send_reconf;
 sctp_state_fn_t sctp_sf_do_6_2_sack;
 sctp_state_fn_t sctp_sf_autoclose_timer_expire;
 
@@ -259,7 +261,10 @@ struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
 				    __u32 new_cum_tsn, size_t nstreams,
 				    struct sctp_fwdtsn_skip *skiplist);
 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc);
-
+struct sctp_chunk *sctp_make_strreset_req(
+				const struct sctp_association *asoc,
+				__u16 stream_num, __u16 *stream_list,
+				bool out, bool in);
 void sctp_chunk_assign_tsn(struct sctp_chunk *);
 void sctp_chunk_assign_ssn(struct sctp_chunk *);
 
@@ -275,6 +280,7 @@ int sctp_do_sm(struct net *net, sctp_event_t event_type, sctp_subtype_t subtype,
 /* 2nd level prototypes */
 void sctp_generate_t3_rtx_event(unsigned long peer);
 void sctp_generate_heartbeat_event(unsigned long peer);
+void sctp_generate_reconf_event(unsigned long peer);
 void sctp_generate_proto_unreach_event(unsigned long peer);
 
 void sctp_ootb_pkt_free(struct sctp_packet *);

include/net/sctp/structs.h

@@ -877,6 +877,9 @@ struct sctp_transport {
 	/* Timer to handle ICMP proto unreachable envets */
 	struct timer_list proto_unreach_timer;
 
+	/* Timer to handler reconf chunk rtx */
+	struct timer_list reconf_timer;
+
 	/* Since we're using per-destination retransmission timers
 	 * (see above), we're also using per-destination "transmitted"
 	 * queues.  This probably ought to be a private struct
@@ -935,6 +938,7 @@ void sctp_transport_pmtu(struct sctp_transport *, struct sock *sk);
 void sctp_transport_free(struct sctp_transport *);
 void sctp_transport_reset_t3_rtx(struct sctp_transport *);
 void sctp_transport_reset_hb_timer(struct sctp_transport *);
+void sctp_transport_reset_reconf_timer(struct sctp_transport *transport);
 int sctp_transport_hold(struct sctp_transport *);
 void sctp_transport_put(struct sctp_transport *);
 void sctp_transport_update_rto(struct sctp_transport *, __u32);
@@ -1251,7 +1255,10 @@ struct sctp_endpoint {
 	struct list_head endpoint_shared_keys;
 	__u16 active_key_id;
 	__u8  auth_enable:1,
-	      prsctp_enable:1;
+	      prsctp_enable:1,
+	      reconf_enable:1;
+
+	__u8  strreset_enable;
 };
 
 /* Recover the outter endpoint structure. */
@@ -1504,6 +1511,7 @@ struct sctp_association {
 			hostname_address:1, /* Peer understands DNS addresses? */
 			asconf_capable:1,   /* Does peer support ADDIP? */
 			prsctp_capable:1,   /* Can peer do PR-SCTP? */
+			reconf_capable:1,   /* Can peer do RE-CONFIG? */
 			auth_capable:1;     /* Is peer doing SCTP-AUTH? */
 
 		/* sack_needed : This flag indicates if the next received
@@ -1863,7 +1871,16 @@ struct sctp_association {
 
 	__u8 need_ecne:1,	/* Need to send an ECNE Chunk? */
 	     temp:1,		/* Is it a temporary association? */
-	     prsctp_enable:1;
+	     prsctp_enable:1,
+	     reconf_enable:1;
+
+	__u8 strreset_enable;
+	__u8 strreset_outstanding; /* request param count on the fly */
+
+	__u32 strreset_outseq; /* Update after receiving response */
+	__u32 strreset_inseq; /* Update after receiving request */
+
+	struct sctp_chunk *strreset_chunk; /* save request chunk */
 
 	struct sctp_priv_assoc_stats stats;
 

include/uapi/linux/sctp.h

@@ -115,6 +115,8 @@ typedef __s32 sctp_assoc_t;
 #define SCTP_PR_SUPPORTED	113
 #define SCTP_DEFAULT_PRINFO	114
 #define SCTP_PR_ASSOC_STATUS	115
+#define SCTP_ENABLE_STREAM_RESET	118
+#define SCTP_RESET_STREAMS	119
 
 /* PR-SCTP policies */
 #define SCTP_PR_SCTP_NONE	0x0000
@@ -138,6 +140,15 @@ typedef __s32 sctp_assoc_t;
 #define SCTP_PR_RTX_ENABLED(x)	(SCTP_PR_POLICY(x) == SCTP_PR_SCTP_RTX)
 #define SCTP_PR_PRIO_ENABLED(x)	(SCTP_PR_POLICY(x) == SCTP_PR_SCTP_PRIO)
 
+/* For enable stream reset */
+#define SCTP_ENABLE_RESET_STREAM_REQ	0x01
+#define SCTP_ENABLE_RESET_ASSOC_REQ	0x02
+#define SCTP_ENABLE_CHANGE_ASSOC_REQ	0x04
+#define SCTP_ENABLE_STRRESET_MASK	0x07
+
+#define SCTP_STREAM_RESET_INCOMING	0x01
+#define SCTP_STREAM_RESET_OUTGOING	0x02
+
 /* These are bit fields for msghdr->msg_flags.  See section 5.1.  */
 /* On user space Linux, these live in <bits/socket.h> as an enum.  */
 enum sctp_msg_flags {
@@ -1008,4 +1019,11 @@ struct sctp_info {
 	__u32	__reserved3;
 };
 
+struct sctp_reset_streams {
+	sctp_assoc_t srs_assoc_id;
+	uint16_t srs_flags;
+	uint16_t srs_number_streams;	/* 0 == ALL */
+	uint16_t srs_stream_list[];	/* list if srs_num_streams is not 0 */
+};
+
 #endif /* _UAPI_SCTP_H */

net/sctp/associola.c

@@ -207,6 +207,7 @@ static struct sctp_association *sctp_association_init(struct sctp_association *a
 	 * association to the same value as the initial TSN.
 	 */
 	asoc->addip_serial = asoc->c.initial_tsn;
+	asoc->strreset_outseq = asoc->c.initial_tsn;
 
 	INIT_LIST_HEAD(&asoc->addip_chunk_list);
 	INIT_LIST_HEAD(&asoc->asconf_ack_list);
@@ -269,6 +270,8 @@ static struct sctp_association *sctp_association_init(struct sctp_association *a
 
 	asoc->active_key_id = ep->active_key_id;
 	asoc->prsctp_enable = ep->prsctp_enable;
+	asoc->reconf_enable = ep->reconf_enable;
+	asoc->strreset_enable = ep->strreset_enable;
 
 	/* Save the hmacs and chunks list into this association */
 	if (ep->auth_hmacs_list)
@@ -361,6 +364,9 @@ void sctp_association_free(struct sctp_association *asoc)
 	/* Free stream information. */
 	sctp_stream_free(asoc->stream);
 
+	if (asoc->strreset_chunk)
+		sctp_chunk_free(asoc->strreset_chunk);
+
 	/* Clean up the bound address list. */
 	sctp_bind_addr_free(&asoc->base.bind_addr);
 
@@ -519,6 +525,12 @@ void sctp_assoc_rm_peer(struct sctp_association *asoc,
 	if (asoc->peer.last_data_from == peer)
 		asoc->peer.last_data_from = transport;
 
+	if (asoc->strreset_chunk &&
+	    asoc->strreset_chunk->transport == peer) {
+		asoc->strreset_chunk->transport = transport;
+		sctp_transport_reset_reconf_timer(transport);
+	}
+
 	/* If we remove the transport an INIT was last sent to, set it to
 	 * NULL. Combined with the update of the retran path above, this
 	 * will cause the next INIT to be sent to the next available

net/sctp/endpointola.c

@@ -164,6 +164,7 @@ static struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep,
 	ep->auth_hmacs_list = auth_hmacs;
 	ep->auth_chunk_list = auth_chunks;
 	ep->prsctp_enable = net->sctp.prsctp_enable;
+	ep->reconf_enable = net->sctp.reconf_enable;
 
 	return ep;
 

net/sctp/outqueue.c

@@ -915,22 +915,28 @@ static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
 		case SCTP_CID_ECN_ECNE:
 		case SCTP_CID_ASCONF:
 		case SCTP_CID_FWD_TSN:
+		case SCTP_CID_RECONF:
 			status = sctp_packet_transmit_chunk(packet, chunk,
 							    one_packet, gfp);
 			if (status  != SCTP_XMIT_OK) {
 				/* put the chunk back */
 				list_add(&chunk->list, &q->control_chunk_list);
-			} else {
-				asoc->stats.octrlchunks++;
-				/* PR-SCTP C5) If a FORWARD TSN is sent, the
-				 * sender MUST assure that at least one T3-rtx
-				 * timer is running.
-				 */
-				if (chunk->chunk_hdr->type == SCTP_CID_FWD_TSN) {
-					sctp_transport_reset_t3_rtx(transport);
-					transport->last_time_sent = jiffies;
-				}
+				break;
+			}
+
+			asoc->stats.octrlchunks++;
+			/* PR-SCTP C5) If a FORWARD TSN is sent, the
+			 * sender MUST assure that at least one T3-rtx
+			 * timer is running.
+			 */
+			if (chunk->chunk_hdr->type == SCTP_CID_FWD_TSN) {
+				sctp_transport_reset_t3_rtx(transport);
+				transport->last_time_sent = jiffies;
 			}
+
+			if (chunk == asoc->strreset_chunk)
+				sctp_transport_reset_reconf_timer(transport);
+
 			break;
 
 		default:
@@ -1016,6 +1022,8 @@ static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
 
 		/* Finally, transmit new packets.  */
 		while ((chunk = sctp_outq_dequeue_data(q)) != NULL) {
+			__u32 sid = ntohs(chunk->subh.data_hdr->stream);
+
 			/* RFC 2960 6.5 Every DATA chunk MUST carry a valid
 			 * stream identifier.
 			 */
@@ -1038,6 +1046,11 @@ static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp)
 				continue;
 			}
 
+			if (asoc->stream->out[sid].state == SCTP_STREAM_CLOSED) {
+				sctp_outq_head_data(q, chunk);
+				goto sctp_flush_out;
+			}
+
 			/* If there is a specified transport, use it.
 			 * Otherwise, we want to use the active path.
 			 */

net/sctp/primitive.c

@@ -211,3 +211,6 @@ DECLARE_PRIMITIVE(REQUESTHEARTBEAT);
 */
 
 DECLARE_PRIMITIVE(ASCONF);
+
+/* RE-CONFIG 5.1 */
+DECLARE_PRIMITIVE(RECONF);

net/sctp/protocol.c

@@ -1258,6 +1258,9 @@ static int __net_init sctp_defaults_init(struct net *net)
 	/* Enable PR-SCTP by default. */
 	net->sctp.prsctp_enable = 1;
 
+	/* Disable RECONF by default. */
+	net->sctp.reconf_enable = 0;
+
 	/* Disable AUTH by default. */
 	net->sctp.auth_enable = 0;
 

net/sctp/sm_make_chunk.c

@@ -270,6 +270,11 @@ struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
 		num_ext += 2;
 	}
 
+	if (asoc->reconf_enable) {
+		extensions[num_ext] = SCTP_CID_RECONF;
+		num_ext += 1;
+	}
+
 	if (sp->adaptation_ind)
 		chunksize += sizeof(aiparam);
 
@@ -434,6 +439,11 @@ struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
 		num_ext += 2;
 	}
 
+	if (asoc->peer.reconf_capable) {
+		extensions[num_ext] = SCTP_CID_RECONF;
+		num_ext += 1;
+	}
+
 	if (sp->adaptation_ind)
 		chunksize += sizeof(aiparam);
 
@@ -1844,6 +1854,7 @@ no_hmac:
 	retval->next_tsn = retval->c.initial_tsn;
 	retval->ctsn_ack_point = retval->next_tsn - 1;
 	retval->addip_serial = retval->c.initial_tsn;
+	retval->strreset_outseq = retval->c.initial_tsn;
 	retval->adv_peer_ack_point = retval->ctsn_ack_point;
 	retval->peer.prsctp_capable = retval->c.prsctp_capable;
 	retval->peer.adaptation_ind = retval->c.adaptation_ind;
@@ -2011,6 +2022,11 @@ static void sctp_process_ext_param(struct sctp_association *asoc,
 
 	for (i = 0; i < num_ext; i++) {
 		switch (param.ext->chunks[i]) {
+		case SCTP_CID_RECONF:
+			if (asoc->reconf_enable &&
+			    !asoc->peer.reconf_capable)
+				asoc->peer.reconf_capable = 1;
+			break;
 		case SCTP_CID_FWD_TSN:
 			if (asoc->prsctp_enable && !asoc->peer.prsctp_capable)
 				asoc->peer.prsctp_capable = 1;
@@ -2387,6 +2403,8 @@ int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk,
 	asoc->peer.i.initial_tsn =
 		ntohl(peer_init->init_hdr.initial_tsn);
 
+	asoc->strreset_inseq = asoc->peer.i.initial_tsn;
+
 	/* Apply the upper bounds for output streams based on peer's
 	 * number of inbound streams.
 	 */
@@ -3524,3 +3542,121 @@ struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
 
 	return retval;
 }
+
+/* RE-CONFIG 3.1 (RE-CONFIG chunk)
+ *   0                   1                   2                   3
+ *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  | Type = 130    |  Chunk Flags  |      Chunk Length             |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  \                                                               \
+ *  /                  Re-configuration Parameter                   /
+ *  \                                                               \
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  \                                                               \
+ *  /             Re-configuration Parameter (optional)             /
+ *  \                                                               \
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ */
+static struct sctp_chunk *sctp_make_reconf(
+				const struct sctp_association *asoc,
+				int length)
+{
+	struct sctp_reconf_chunk *reconf;
+	struct sctp_chunk *retval;
+
+	retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length,
+				   GFP_ATOMIC);
+	if (!retval)
+		return NULL;
+
+	reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr;
+	retval->param_hdr.v = reconf->params;
+
+	return retval;
+}
+
+/* RE-CONFIG 4.1 (STREAM OUT RESET)
+ *   0                   1                   2                   3
+ *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |     Parameter Type = 13       | Parameter Length = 16 + 2 * N |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |           Re-configuration Request Sequence Number            |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |           Re-configuration Response Sequence Number           |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |                Sender's Last Assigned TSN                     |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |  Stream Number 1 (optional)   |    Stream Number 2 (optional) |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  /                            ......                             /
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |  Stream Number N-1 (optional) |    Stream Number N (optional) |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ * RE-CONFIG 4.2 (STREAM IN RESET)
+ *   0                   1                   2                   3
+ *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |     Parameter Type = 14       |  Parameter Length = 8 + 2 * N |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |          Re-configuration Request Sequence Number             |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |  Stream Number 1 (optional)   |    Stream Number 2 (optional) |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  /                            ......                             /
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |  Stream Number N-1 (optional) |    Stream Number N (optional) |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ */
+struct sctp_chunk *sctp_make_strreset_req(
+				const struct sctp_association *asoc,
+				__u16 stream_num, __u16 *stream_list,
+				bool out, bool in)
+{
+	struct sctp_strreset_outreq outreq;
+	__u16 stream_len = stream_num * 2;
+	struct sctp_strreset_inreq inreq;
+	struct sctp_chunk *retval;
+	__u16 outlen, inlen, i;
+
+	outlen = (sizeof(outreq) + stream_len) * out;
+	inlen = (sizeof(inreq) + stream_len) * in;
+
+	retval = sctp_make_reconf(asoc, outlen + inlen);
+	if (!retval)
+		return NULL;
+
+	for (i = 0; i < stream_num; i++)
+		stream_list[i] = htons(stream_list[i]);
+
+	if (outlen) {
+		outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST;
+		outreq.param_hdr.length = htons(outlen);
+		outreq.request_seq = htonl(asoc->strreset_outseq);
+		outreq.response_seq = htonl(asoc->strreset_inseq - 1);
+		outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1);
+
+		sctp_addto_chunk(retval, sizeof(outreq), &outreq);
+
+		if (stream_len)
+			sctp_addto_chunk(retval, stream_len, stream_list);
+	}
+
+	if (inlen) {
+		inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST;
+		inreq.param_hdr.length = htons(inlen);
+		inreq.request_seq = htonl(asoc->strreset_outseq + out);
+
+		sctp_addto_chunk(retval, sizeof(inreq), &inreq);
+
+		if (stream_len)
+			sctp_addto_chunk(retval, stream_len, stream_list);
+	}
+
+	for (i = 0; i < stream_num; i++)
+		stream_list[i] = ntohs(stream_list[i]);
+
+	return retval;
+}

net/sctp/sm_sideeffect.c

@@ -436,6 +436,37 @@ out_unlock:
 	sctp_association_put(asoc);
 }
 
+ /* Handle the timeout of the RE-CONFIG timer. */
+void sctp_generate_reconf_event(unsigned long data)
+{
+	struct sctp_transport *transport = (struct sctp_transport *)data;
+	struct sctp_association *asoc = transport->asoc;
+	struct sock *sk = asoc->base.sk;
+	struct net *net = sock_net(sk);
+	int error = 0;
+
+	bh_lock_sock(sk);
+	if (sock_owned_by_user(sk)) {
+		pr_debug("%s: sock is busy\n", __func__);
+
+		/* Try again later.  */
+		if (!mod_timer(&transport->reconf_timer, jiffies + (HZ / 20)))
+			sctp_transport_hold(transport);
+		goto out_unlock;
+	}
+
+	error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
+			   SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_RECONF),
+			   asoc->state, asoc->ep, asoc,
+			   transport, GFP_ATOMIC);
+
+	if (error)
+		sk->sk_err = -error;
+
+out_unlock:
+	bh_unlock_sock(sk);
+	sctp_transport_put(transport);
+}
 
 /* Inject a SACK Timeout event into the state machine.  */
 static void sctp_generate_sack_event(unsigned long data)
@@ -453,6 +484,7 @@ sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
 	sctp_generate_t4_rto_event,
 	sctp_generate_t5_shutdown_guard_event,
 	NULL,
+	NULL,
 	sctp_generate_sack_event,
 	sctp_generate_autoclose_event,
 };

net/sctp/sm_statefuns.c

@@ -1021,6 +1021,34 @@ sctp_disposition_t sctp_sf_sendbeat_8_3(struct net *net,
 	return SCTP_DISPOSITION_CONSUME;
 }
 
+/* resend asoc strreset_chunk.  */
+sctp_disposition_t sctp_sf_send_reconf(struct net *net,
+				       const struct sctp_endpoint *ep,
+				       const struct sctp_association *asoc,
+				       const sctp_subtype_t type, void *arg,
+				       sctp_cmd_seq_t *commands)
+{
+	struct sctp_transport *transport = arg;
+
+	if (asoc->overall_error_count >= asoc->max_retrans) {
+		sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
+				SCTP_ERROR(ETIMEDOUT));
+		/* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
+		sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
+				SCTP_PERR(SCTP_ERROR_NO_ERROR));
+		SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
+		SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
+		return SCTP_DISPOSITION_DELETE_TCB;
+	}
+
+	sctp_chunk_hold(asoc->strreset_chunk);
+	sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
+			SCTP_CHUNK(asoc->strreset_chunk));
+	sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
+
+	return SCTP_DISPOSITION_CONSUME;
+}
+
 /*
  * Process an heartbeat request.
  *
@@ -5157,6 +5185,19 @@ sctp_disposition_t sctp_sf_do_prm_asconf(struct net *net,
 	return SCTP_DISPOSITION_CONSUME;
 }
 
+/* RE-CONFIG Section 5.1 RECONF Chunk Procedures */
+sctp_disposition_t sctp_sf_do_prm_reconf(struct net *net,
+					 const struct sctp_endpoint *ep,
+					 const struct sctp_association *asoc,
+					 const sctp_subtype_t type,
+					 void *arg, sctp_cmd_seq_t *commands)
+{
+	struct sctp_chunk *chunk = arg;
+
+	sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
+	return SCTP_DISPOSITION_CONSUME;
+}
+
 /*
  * Ignore the primitive event
  *

net/sctp/sm_statetable.c

@@ -643,6 +643,25 @@ chunk_event_table_unknown[SCTP_STATE_NUM_STATES] = {
 	TYPE_SCTP_FUNC(sctp_sf_error_shutdown), \
 } /* TYPE_SCTP_PRIMITIVE_ASCONF */
 
+#define TYPE_SCTP_PRIMITIVE_RECONF { \
+	/* SCTP_STATE_CLOSED */ \
+	TYPE_SCTP_FUNC(sctp_sf_error_closed), \
+	/* SCTP_STATE_COOKIE_WAIT */ \
+	TYPE_SCTP_FUNC(sctp_sf_error_closed), \
+	/* SCTP_STATE_COOKIE_ECHOED */ \
+	TYPE_SCTP_FUNC(sctp_sf_error_closed), \
+	/* SCTP_STATE_ESTABLISHED */ \
+	TYPE_SCTP_FUNC(sctp_sf_do_prm_reconf), \
+	/* SCTP_STATE_SHUTDOWN_PENDING */ \
+	TYPE_SCTP_FUNC(sctp_sf_do_prm_reconf), \
+	/* SCTP_STATE_SHUTDOWN_SENT */ \
+	TYPE_SCTP_FUNC(sctp_sf_do_prm_reconf), \
+	/* SCTP_STATE_SHUTDOWN_RECEIVED */ \
+	TYPE_SCTP_FUNC(sctp_sf_do_prm_reconf), \
+	/* SCTP_STATE_SHUTDOWN_ACK_SENT */ \
+	TYPE_SCTP_FUNC(sctp_sf_error_shutdown), \
+} /* TYPE_SCTP_PRIMITIVE_RECONF */
+
 /* The primary index for this table is the primitive type.
  * The secondary index for this table is the state.
  */
@@ -653,6 +672,7 @@ static const sctp_sm_table_entry_t primitive_event_table[SCTP_NUM_PRIMITIVE_TYPE
 	TYPE_SCTP_PRIMITIVE_SEND,
 	TYPE_SCTP_PRIMITIVE_REQUESTHEARTBEAT,
 	TYPE_SCTP_PRIMITIVE_ASCONF,
+	TYPE_SCTP_PRIMITIVE_RECONF,
 };
 
 #define TYPE_SCTP_OTHER_NO_PENDING_TSN  { \
@@ -888,6 +908,25 @@ static const sctp_sm_table_entry_t other_event_table[SCTP_NUM_OTHER_TYPES][SCTP_
 	TYPE_SCTP_FUNC(sctp_sf_timer_ignore), \
 }
 
+#define TYPE_SCTP_EVENT_TIMEOUT_RECONF { \
+	/* SCTP_STATE_CLOSED */ \
+	TYPE_SCTP_FUNC(sctp_sf_timer_ignore), \
+	/* SCTP_STATE_COOKIE_WAIT */ \
+	TYPE_SCTP_FUNC(sctp_sf_timer_ignore), \
+	/* SCTP_STATE_COOKIE_ECHOED */ \
+	TYPE_SCTP_FUNC(sctp_sf_timer_ignore), \
+	/* SCTP_STATE_ESTABLISHED */ \
+	TYPE_SCTP_FUNC(sctp_sf_send_reconf), \
+	/* SCTP_STATE_SHUTDOWN_PENDING */ \
+	TYPE_SCTP_FUNC(sctp_sf_timer_ignore), \
+	/* SCTP_STATE_SHUTDOWN_SENT */ \
+	TYPE_SCTP_FUNC(sctp_sf_timer_ignore), \
+	/* SCTP_STATE_SHUTDOWN_RECEIVED */ \
+	TYPE_SCTP_FUNC(sctp_sf_timer_ignore), \
+	/* SCTP_STATE_SHUTDOWN_ACK_SENT */ \
+	TYPE_SCTP_FUNC(sctp_sf_timer_ignore), \
+}
+
 static const sctp_sm_table_entry_t timeout_event_table[SCTP_NUM_TIMEOUT_TYPES][SCTP_STATE_NUM_STATES] = {
 	TYPE_SCTP_EVENT_TIMEOUT_NONE,
 	TYPE_SCTP_EVENT_TIMEOUT_T1_COOKIE,
@@ -897,6 +936,7 @@ static const sctp_sm_table_entry_t timeout_event_table[SCTP_NUM_TIMEOUT_TYPES][S
 	TYPE_SCTP_EVENT_TIMEOUT_T4_RTO,
 	TYPE_SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD,
 	TYPE_SCTP_EVENT_TIMEOUT_HEARTBEAT,
+	TYPE_SCTP_EVENT_TIMEOUT_RECONF,
 	TYPE_SCTP_EVENT_TIMEOUT_SACK,
 	TYPE_SCTP_EVENT_TIMEOUT_AUTOCLOSE,
 };

net/sctp/socket.c

@@ -3750,6 +3750,68 @@ out:
 	return retval;
 }
 
+static int sctp_setsockopt_enable_strreset(struct sock *sk,
+					   char __user *optval,
+					   unsigned int optlen)
+{
+	struct sctp_assoc_value params;
+	struct sctp_association *asoc;
+	int retval = -EINVAL;
+
+	if (optlen != sizeof(params))
+		goto out;
+
+	if (copy_from_user(&params, optval, optlen)) {
+		retval = -EFAULT;
+		goto out;
+	}
+
+	if (params.assoc_value & (~SCTP_ENABLE_STRRESET_MASK))
+		goto out;
+
+	asoc = sctp_id2assoc(sk, params.assoc_id);
+	if (asoc) {
+		asoc->strreset_enable = params.assoc_value;
+	} else if (!params.assoc_id) {
+		struct sctp_sock *sp = sctp_sk(sk);
+
+		sp->ep->strreset_enable = params.assoc_value;
+	} else {
+		goto out;
+	}
+
+	retval = 0;
+
+out:
+	return retval;
+}
+
+static int sctp_setsockopt_reset_streams(struct sock *sk,
+					 char __user *optval,
+					 unsigned int optlen)
+{
+	struct sctp_reset_streams *params;
+	struct sctp_association *asoc;
+	int retval = -EINVAL;
+
+	if (optlen < sizeof(struct sctp_reset_streams))
+		return -EINVAL;
+
+	params = memdup_user(optval, optlen);
+	if (IS_ERR(params))
+		return PTR_ERR(params);
+
+	asoc = sctp_id2assoc(sk, params->srs_assoc_id);
+	if (!asoc)
+		goto out;
+
+	retval = sctp_send_reset_streams(asoc, params);
+
+out:
+	kfree(params);
+	return retval;
+}
+
 /* API 6.2 setsockopt(), getsockopt()
  *
  * Applications use setsockopt() and getsockopt() to set or retrieve
@@ -3916,6 +3978,12 @@ static int sctp_setsockopt(struct sock *sk, int level, int optname,
 	case SCTP_DEFAULT_PRINFO:
 		retval = sctp_setsockopt_default_prinfo(sk, optval, optlen);
 		break;
+	case SCTP_ENABLE_STREAM_RESET:
+		retval = sctp_setsockopt_enable_strreset(sk, optval, optlen);
+		break;
+	case SCTP_RESET_STREAMS:
+		retval = sctp_setsockopt_reset_streams(sk, optval, optlen);
+		break;
 	default:
 		retval = -ENOPROTOOPT;
 		break;
@@ -6400,6 +6468,47 @@ out:
 	return retval;
 }
 
+static int sctp_getsockopt_enable_strreset(struct sock *sk, int len,
+					   char __user *optval,
+					   int __user *optlen)
+{
+	struct sctp_assoc_value params;
+	struct sctp_association *asoc;
+	int retval = -EFAULT;
+
+	if (len < sizeof(params)) {
+		retval = -EINVAL;
+		goto out;
+	}
+
+	len = sizeof(params);
+	if (copy_from_user(&params, optval, len))
+		goto out;
+
+	asoc = sctp_id2assoc(sk, params.assoc_id);
+	if (asoc) {
+		params.assoc_value = asoc->strreset_enable;
+	} else if (!params.assoc_id) {
+		struct sctp_sock *sp = sctp_sk(sk);
+
+		params.assoc_value = sp->ep->strreset_enable;
+	} else {
+		retval = -EINVAL;
+		goto out;
+	}
+
+	if (put_user(len, optlen))
+		goto out;
+
+	if (copy_to_user(optval, &params, len))
+		goto out;
+
+	retval = 0;
+
+out:
+	return retval;
+}
+
 static int sctp_getsockopt(struct sock *sk, int level, int optname,
 			   char __user *optval, int __user *optlen)
 {
@@ -6567,6 +6676,10 @@ static int sctp_getsockopt(struct sock *sk, int level, int optname,
 		retval = sctp_getsockopt_pr_assocstatus(sk, len, optval,
 							optlen);
 		break;
+	case SCTP_ENABLE_STREAM_RESET:
+		retval = sctp_getsockopt_enable_strreset(sk, len, optval,
+							 optlen);
+		break;
 	default:
 		retval = -ENOPROTOOPT;
 		break;

net/sctp/stream.c

@@ -33,6 +33,7 @@
  */
 
 #include <net/sctp/sctp.h>
+#include <net/sctp/sm.h>
 
 struct sctp_stream *sctp_stream_new(__u16 incnt, __u16 outcnt, gfp_t gfp)
 {
@@ -83,3 +84,81 @@ void sctp_stream_clear(struct sctp_stream *stream)
 	for (i = 0; i < stream->incnt; i++)
 		stream->in[i].ssn = 0;
 }
+
+static int sctp_send_reconf(struct sctp_association *asoc,
+			    struct sctp_chunk *chunk)
+{
+	struct net *net = sock_net(asoc->base.sk);
+	int retval = 0;
+
+	retval = sctp_primitive_RECONF(net, asoc, chunk);
+	if (retval)
+		sctp_chunk_free(chunk);
+
+	return retval;
+}
+
+int sctp_send_reset_streams(struct sctp_association *asoc,
+			    struct sctp_reset_streams *params)
+{
+	struct sctp_stream *stream = asoc->stream;
+	__u16 i, str_nums, *str_list;
+	struct sctp_chunk *chunk;
+	int retval = -EINVAL;
+	bool out, in;
+
+	if (!asoc->peer.reconf_capable ||
+	    !(asoc->strreset_enable & SCTP_ENABLE_RESET_STREAM_REQ)) {
+		retval = -ENOPROTOOPT;
+		goto out;
+	}
+
+	if (asoc->strreset_outstanding) {
+		retval = -EINPROGRESS;
+		goto out;
+	}
+
+	out = params->srs_flags & SCTP_STREAM_RESET_OUTGOING;
+	in  = params->srs_flags & SCTP_STREAM_RESET_INCOMING;
+	if (!out && !in)
+		goto out;
+
+	str_nums = params->srs_number_streams;
+	str_list = params->srs_stream_list;
+	if (out && str_nums)
+		for (i = 0; i < str_nums; i++)
+			if (str_list[i] >= stream->outcnt)
+				goto out;
+
+	if (in && str_nums)
+		for (i = 0; i < str_nums; i++)
+			if (str_list[i] >= stream->incnt)
+				goto out;
+
+	chunk = sctp_make_strreset_req(asoc, str_nums, str_list, out, in);
+	if (!chunk)
+		goto out;
+
+	if (out) {
+		if (str_nums)
+			for (i = 0; i < str_nums; i++)
+				stream->out[str_list[i]].state =
+						       SCTP_STREAM_CLOSED;
+		else
+			for (i = 0; i < stream->outcnt; i++)
+				stream->out[i].state = SCTP_STREAM_CLOSED;
+	}
+
+	asoc->strreset_outstanding = out + in;
+	asoc->strreset_chunk = chunk;
+	sctp_chunk_hold(asoc->strreset_chunk);
+
+	retval = sctp_send_reconf(asoc, chunk);
+	if (retval) {
+		sctp_chunk_put(asoc->strreset_chunk);
+		asoc->strreset_chunk = NULL;
+	}
+
+out:
+	return retval;
+}

net/sctp/transport.c

@@ -88,9 +88,11 @@ static struct sctp_transport *sctp_transport_init(struct net *net,
 	INIT_LIST_HEAD(&peer->transports);
 
 	setup_timer(&peer->T3_rtx_timer, sctp_generate_t3_rtx_event,
-			(unsigned long)peer);
+		    (unsigned long)peer);
 	setup_timer(&peer->hb_timer, sctp_generate_heartbeat_event,
-			(unsigned long)peer);
+		    (unsigned long)peer);
+	setup_timer(&peer->reconf_timer, sctp_generate_reconf_event,
+		    (unsigned long)peer);
 	setup_timer(&peer->proto_unreach_timer,
 		    sctp_generate_proto_unreach_event, (unsigned long)peer);
 
@@ -144,6 +146,9 @@ void sctp_transport_free(struct sctp_transport *transport)
 	if (del_timer(&transport->T3_rtx_timer))
 		sctp_transport_put(transport);
 
+	if (del_timer(&transport->reconf_timer))
+		sctp_transport_put(transport);
+
 	/* Delete the ICMP proto unreachable timer if it's active. */
 	if (del_timer(&transport->proto_unreach_timer))
 		sctp_association_put(transport->asoc);
@@ -211,6 +216,14 @@ void sctp_transport_reset_hb_timer(struct sctp_transport *transport)
 		sctp_transport_hold(transport);
 }
 
+void sctp_transport_reset_reconf_timer(struct sctp_transport *transport)
+{
+	if (!timer_pending(&transport->reconf_timer))
+		if (!mod_timer(&transport->reconf_timer,
+			       jiffies + transport->rto))
+			sctp_transport_hold(transport);
+}
+
 /* This transport has been assigned to an association.
  * Initialize fields from the association or from the sock itself.
  * Register the reference count in the association.