[SCTP]: Verify all the paths to a peer via heartbeat before using them.

This patch implements Path Initialization procedure as described in Sec 2.36 of RFC4460. Signed-off-by: Sridhar Samudrala <sri@us.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>

[SCTP]: Verify all the paths to a peer via heartbeat before using them.
This patch implements Path Initialization procedure as described in Sec 2.36 of RFC4460. Signed-off-by: Sridhar Samudrala <sri@us.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Sridhar Samudrala · David S. Miller
1 parent cfdeef3282
Showing 8 changed files with 60 additions and 19 deletions Side-by-side Diff
include/net/sctp/structs.h
include/net/sctp/user.h
net/sctp/associola.c
net/sctp/outqueue.c
net/sctp/sm_make_chunk.c
net/sctp/sm_sideeffect.c
net/sctp/sm_statefuns.c
net/sctp/transport.c
@@ -445,6 +445,7 @@
 	struct sctp_paramhdr param_hdr;
 	union sctp_addr daddr;
 	unsigned long sent_at;
+	__u64 hb_nonce;
 } __attribute__((packed)) sctp_sender_hb_info_t;
  
 /*
@@ -984,6 +985,9 @@
 		 */
 		char cacc_saw_newack;
 	} cacc;
+
+	/* 64-bit random number sent with heartbeat. */
+	__u64 hb_nonce;
 };
  
 struct sctp_transport *sctp_transport_new(const union sctp_addr *,
@@ -560,9 +560,18 @@
 } __attribute__((packed, aligned(4)));
  
 /* Peer addresses's state. */
+/* UNKNOWN: Peer address passed by the upper layer in sendmsg or connect[x]
+ * calls.
+ * UNCONFIRMED: Peer address received in INIT/INIT-ACK address parameters.
+ *              Not yet confirmed by a heartbeat and not available for data
+ *		transfers.
+ * ACTIVE : Peer address confirmed, active and available for data transfers.
+ * INACTIVE: Peer address inactive and not available for data transfers.
+ */
 enum sctp_spinfo_state {
 	SCTP_INACTIVE,
 	SCTP_ACTIVE,
+	SCTP_UNCONFIRMED,
 	SCTP_UNKNOWN = 0xffff  /* Value used for transport state unknown */
 };
  
@@ -441,7 +441,8 @@
 	/* If the primary path is changing, assume that the
 	 * user wants to use this new path.
 	 */
-	if (transport->state != SCTP_INACTIVE)
+	if ((transport->state == SCTP_ACTIVE) ||
+	    (transport->state == SCTP_UNKNOWN))
 		asoc->peer.active_path = transport;
  
 	/*
  
@@ -532,11 +533,11 @@
 	port = addr->v4.sin_port;
  
 	SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_add_peer:association %p addr: ",
-				 " port: %d state:%s\n",
+				 " port: %d state:%d\n",
 				 asoc,
 				 addr,
 				 addr->v4.sin_port,
-				 peer_state == SCTP_UNKNOWN?"UNKNOWN":"ACTIVE");
+				 peer_state);
  
 	/* Set the port if it has not been set yet.  */
 	if (0 == asoc->peer.port)
@@ -545,9 +546,12 @@
 	/* Check to see if this is a duplicate. */
 	peer = sctp_assoc_lookup_paddr(asoc, addr);
 	if (peer) {
-		if (peer_state == SCTP_ACTIVE &&
-		    peer->state == SCTP_UNKNOWN)
-		     peer->state = SCTP_ACTIVE;
+		if (peer->state == SCTP_UNKNOWN) {
+			if (peer_state == SCTP_ACTIVE)
+				peer->state = SCTP_ACTIVE;
+			if (peer_state == SCTP_UNCONFIRMED)
+				peer->state = SCTP_UNCONFIRMED;
+		}
 		return peer;
 	}
  
@@ -739,7 +743,8 @@
 	list_for_each(pos, &asoc->peer.transport_addr_list) {
 		t = list_entry(pos, struct sctp_transport, transports);
  
-		if (t->state == SCTP_INACTIVE)
+		if ((t->state == SCTP_INACTIVE) ||
+		    (t->state == SCTP_UNCONFIRMED))
 			continue;
 		if (!first || t->last_time_heard > first->last_time_heard) {
 			second = first;
@@ -759,7 +764,8 @@
 	 * [If the primary is active but not most recent, bump the most
 	 * recently used transport.]
 	 */
-	if (asoc->peer.primary_path->state != SCTP_INACTIVE &&
+	if (((asoc->peer.primary_path->state == SCTP_ACTIVE) ||
+	     (asoc->peer.primary_path->state == SCTP_UNKNOWN)) &&
 	    first != asoc->peer.primary_path) {
 		second = first;
 		first = asoc->peer.primary_path;
@@ -1054,7 +1060,7 @@
 					   transports);
 			if (!sctp_assoc_lookup_paddr(asoc, &trans->ipaddr))
 				sctp_assoc_add_peer(asoc, &trans->ipaddr,
-						    GFP_ATOMIC, SCTP_ACTIVE);
+						    GFP_ATOMIC, trans->state);
 		}
  
 		asoc->ctsn_ack_point = asoc->next_tsn - 1;
@@ -1094,7 +1100,8 @@
  
 		/* Try to find an active transport. */
  
-		if (t->state != SCTP_INACTIVE) {
+		if ((t->state == SCTP_ACTIVE) ||
+		    (t->state == SCTP_UNKNOWN)) {
 			break;
 		} else {
 			/* Keep track of the next transport in case
@@ -691,7 +691,8 @@
  
 		if (!new_transport) {
 			new_transport = asoc->peer.active_path;
-		} else if (new_transport->state == SCTP_INACTIVE) {
+		} else if ((new_transport->state == SCTP_INACTIVE) ||
+			   (new_transport->state == SCTP_UNCONFIRMED)) {
 			/* If the chunk is Heartbeat or Heartbeat Ack,
 			 * send it to chunk->transport, even if it's
 			 * inactive.
@@ -848,7 +849,8 @@
 			 */
 			new_transport = chunk->transport;
 			if (!new_transport ||
-			    new_transport->state == SCTP_INACTIVE)
+			    ((new_transport->state == SCTP_INACTIVE) ||
+			     (new_transport->state == SCTP_UNCONFIRMED)))
 				new_transport = asoc->peer.active_path;
  
 			/* Change packets if necessary.  */
@@ -1464,7 +1466,8 @@
 			/* Mark the destination transport address as
 			 * active if it is not so marked.
 			 */
-			if (transport->state == SCTP_INACTIVE) {
+			if ((transport->state == SCTP_INACTIVE) ||
+			    (transport->state == SCTP_UNCONFIRMED)) {
 				sctp_assoc_control_transport(
 					transport->asoc,
 					transport,
@@ -2017,7 +2017,7 @@
 		af->from_addr_param(&addr, param.addr, asoc->peer.port, 0);
 		scope = sctp_scope(peer_addr);
 		if (sctp_in_scope(&addr, scope))
-			if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_ACTIVE))
+			if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED))
 				return 0;
 		break;
  
@@ -2418,7 +2418,7 @@
 	 	 * Due to Resource Shortage'.
 	 	 */
  
-		peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_ACTIVE);
+		peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED);
 		if (!peer)
 			return SCTP_ERROR_RSRC_LOW;
  
@@ -430,7 +430,11 @@
 	/* The check for association's overall error counter exceeding the
 	 * threshold is done in the state function.
 	 */
-	asoc->overall_error_count++;
+	/* When probing UNCONFIRMED addresses, the association overall
+	 * error count is NOT incremented
+	 */
+	if (transport->state != SCTP_UNCONFIRMED)
+		asoc->overall_error_count++;
  
 	if (transport->state != SCTP_INACTIVE &&
 	    (transport->error_count++ >= transport->pathmaxrxt)) {
@@ -610,7 +614,7 @@
 	/* Mark the destination transport address as active if it is not so
 	 * marked.
 	 */
-	if (t->state == SCTP_INACTIVE)
+	if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED))
 		sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 					     SCTP_HEARTBEAT_SUCCESS);
  
@@ -620,6 +624,10 @@
 	 */
 	hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
 	sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
+
+	/* Update the heartbeat timer.  */
+	if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
+		sctp_transport_hold(t);
 }
  
 /* Helper function to do a transport reset at the expiry of the hearbeat
@@ -846,6 +846,7 @@
 	hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t));
 	hbinfo.daddr = transport->ipaddr;
 	hbinfo.sent_at = jiffies;
+	hbinfo.hb_nonce = transport->hb_nonce;
  
 	/* Send a heartbeat to our peer.  */
 	paylen = sizeof(sctp_sender_hb_info_t);
@@ -1047,6 +1048,10 @@
 		}
 		return SCTP_DISPOSITION_DISCARD;
 	}
+
+	/* Validate the 64-bit random nonce. */
+	if (hbinfo->hb_nonce != link->hb_nonce)
+		return SCTP_DISPOSITION_DISCARD;
  
 	max_interval = link->hbinterval + link->rto;
  
@@ -49,6 +49,7 @@
  */
  
 #include <linux/types.h>
+#include <linux/random.h>
 #include <net/sctp/sctp.h>
 #include <net/sctp/sm.h>
  
@@ -85,7 +86,6 @@
  
 	peer->init_sent_count = 0;
  
-	peer->state = SCTP_ACTIVE;
 	peer->param_flags = SPP_HB_DISABLE |
 			    SPP_PMTUD_ENABLE |
 			    SPP_SACKDELAY_ENABLE;
@@ -109,6 +109,9 @@
 	peer->hb_timer.function = sctp_generate_heartbeat_event;
 	peer->hb_timer.data = (unsigned long)peer;
  
+	/* Initialize the 64-bit random nonce sent with heartbeat. */
+	get_random_bytes(&peer->hb_nonce, sizeof(peer->hb_nonce));
+
 	atomic_set(&peer->refcnt, 1);
 	peer->dead = 0;
  
@@ -517,7 +520,9 @@
 unsigned long sctp_transport_timeout(struct sctp_transport *t)
 {
 	unsigned long timeout;
-	timeout = t->hbinterval + t->rto + sctp_jitter(t->rto);
+	timeout = t->rto + sctp_jitter(t->rto);
+	if (t->state != SCTP_UNCONFIRMED)
+		timeout += t->hbinterval;
 	timeout += jiffies;
 	return timeout;
 }
...	...	@@ -445,6 +445,7 @@
445	445	struct sctp_paramhdr param_hdr;
446	446	union sctp_addr daddr;
447	447	unsigned long sent_at;
	448	+ __u64 hb_nonce;
448	449	} __attribute__((packed)) sctp_sender_hb_info_t;
449	450
450	451	/*
...	...	@@ -984,6 +985,9 @@
984	985	*/
985	986	char cacc_saw_newack;
986	987	} cacc;
	988	+
	989	+ /* 64-bit random number sent with heartbeat. */
	990	+ __u64 hb_nonce;
987	991	};
988	992
989	993	struct sctp_transport sctp_transport_new(const union sctp_addr ,
...	...	@@ -560,9 +560,18 @@
560	560	} __attribute__((packed, aligned(4)));
561	561
562	562	/* Peer addresses's state. */
	563	+/* UNKNOWN: Peer address passed by the upper layer in sendmsg or connect[x]
	564	+ * calls.
	565	+ * UNCONFIRMED: Peer address received in INIT/INIT-ACK address parameters.
	566	+ * Not yet confirmed by a heartbeat and not available for data
	567	+ * transfers.
	568	+ * ACTIVE : Peer address confirmed, active and available for data transfers.
	569	+ * INACTIVE: Peer address inactive and not available for data transfers.
	570	+ */
563	571	enum sctp_spinfo_state {
564	572	SCTP_INACTIVE,
565	573	SCTP_ACTIVE,
	574	+ SCTP_UNCONFIRMED,
566	575	SCTP_UNKNOWN = 0xffff /* Value used for transport state unknown */
567	576	};
568	577
...	...	@@ -441,7 +441,8 @@
441	441	/* If the primary path is changing, assume that the
442	442	* user wants to use this new path.
443	443	*/
444		- if (transport->state != SCTP_INACTIVE)
	444	+ if ((transport->state == SCTP_ACTIVE) \|\|
	445	+ (transport->state == SCTP_UNKNOWN))
445	446	asoc->peer.active_path = transport;
446	447
447	448	/*
448	449
...	...	@@ -532,11 +533,11 @@
532	533	port = addr->v4.sin_port;
533	534
534	535	SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_add_peer:association %p addr: ",
535		- " port: %d state:%s\n",
	536	+ " port: %d state:%d\n",
536	537	asoc,
537	538	addr,
538	539	addr->v4.sin_port,
539		- peer_state == SCTP_UNKNOWN?"UNKNOWN":"ACTIVE");
	540	+ peer_state);
540	541
541	542	/* Set the port if it has not been set yet. */
542	543	if (0 == asoc->peer.port)
...	...	@@ -545,9 +546,12 @@
545	546	/* Check to see if this is a duplicate. */
546	547	peer = sctp_assoc_lookup_paddr(asoc, addr);
547	548	if (peer) {
548		- if (peer_state == SCTP_ACTIVE &&
549		- peer->state == SCTP_UNKNOWN)
550		- peer->state = SCTP_ACTIVE;
	549	+ if (peer->state == SCTP_UNKNOWN) {
	550	+ if (peer_state == SCTP_ACTIVE)
	551	+ peer->state = SCTP_ACTIVE;
	552	+ if (peer_state == SCTP_UNCONFIRMED)
	553	+ peer->state = SCTP_UNCONFIRMED;
	554	+ }
551	555	return peer;
552	556	}
553	557
...	...	@@ -739,7 +743,8 @@
739	743	list_for_each(pos, &asoc->peer.transport_addr_list) {
740	744	t = list_entry(pos, struct sctp_transport, transports);
741	745
742		- if (t->state == SCTP_INACTIVE)
	746	+ if ((t->state == SCTP_INACTIVE) \|\|
	747	+ (t->state == SCTP_UNCONFIRMED))
743	748	continue;
744	749	if (!first \|\| t->last_time_heard > first->last_time_heard) {
745	750	second = first;
...	...	@@ -759,7 +764,8 @@
759	764	* [If the primary is active but not most recent, bump the most
760	765	* recently used transport.]
761	766	*/
762		- if (asoc->peer.primary_path->state != SCTP_INACTIVE &&
	767	+ if (((asoc->peer.primary_path->state == SCTP_ACTIVE) \|\|
	768	+ (asoc->peer.primary_path->state == SCTP_UNKNOWN)) &&
763	769	first != asoc->peer.primary_path) {
764	770	second = first;
765	771	first = asoc->peer.primary_path;
...	...	@@ -1054,7 +1060,7 @@
1054	1060	transports);
1055	1061	if (!sctp_assoc_lookup_paddr(asoc, &trans->ipaddr))
1056	1062	sctp_assoc_add_peer(asoc, &trans->ipaddr,
1057		- GFP_ATOMIC, SCTP_ACTIVE);
	1063	+ GFP_ATOMIC, trans->state);
1058	1064	}
1059	1065
1060	1066	asoc->ctsn_ack_point = asoc->next_tsn - 1;
...	...	@@ -1094,7 +1100,8 @@
1094	1100
1095	1101	/* Try to find an active transport. */
1096	1102
1097		- if (t->state != SCTP_INACTIVE) {
	1103	+ if ((t->state == SCTP_ACTIVE) \|\|
	1104	+ (t->state == SCTP_UNKNOWN)) {
1098	1105	break;
1099	1106	} else {
1100	1107	/* Keep track of the next transport in case
...	...	@@ -691,7 +691,8 @@
691	691
692	692	if (!new_transport) {
693	693	new_transport = asoc->peer.active_path;
694		- } else if (new_transport->state == SCTP_INACTIVE) {
	694	+ } else if ((new_transport->state == SCTP_INACTIVE) \|\|
	695	+ (new_transport->state == SCTP_UNCONFIRMED)) {
695	696	/* If the chunk is Heartbeat or Heartbeat Ack,
696	697	* send it to chunk->transport, even if it's
697	698	* inactive.
...	...	@@ -848,7 +849,8 @@
848	849	*/
849	850	new_transport = chunk->transport;
850	851	if (!new_transport \|\|
851		- new_transport->state == SCTP_INACTIVE)
	852	+ ((new_transport->state == SCTP_INACTIVE) \|\|
	853	+ (new_transport->state == SCTP_UNCONFIRMED)))
852	854	new_transport = asoc->peer.active_path;
853	855
854	856	/* Change packets if necessary. */
...	...	@@ -1464,7 +1466,8 @@
1464	1466	/* Mark the destination transport address as
1465	1467	* active if it is not so marked.
1466	1468	*/
1467		- if (transport->state == SCTP_INACTIVE) {
	1469	+ if ((transport->state == SCTP_INACTIVE) \|\|
	1470	+ (transport->state == SCTP_UNCONFIRMED)) {
1468	1471	sctp_assoc_control_transport(
1469	1472	transport->asoc,
1470	1473	transport,
...	...	@@ -2017,7 +2017,7 @@
2017	2017	af->from_addr_param(&addr, param.addr, asoc->peer.port, 0);
2018	2018	scope = sctp_scope(peer_addr);
2019	2019	if (sctp_in_scope(&addr, scope))
2020		- if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_ACTIVE))
	2020	+ if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED))
2021	2021	return 0;
2022	2022	break;
2023	2023
...	...	@@ -2418,7 +2418,7 @@
2418	2418	* Due to Resource Shortage'.
2419	2419	*/
2420	2420
2421		- peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_ACTIVE);
	2421	+ peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED);
2422	2422	if (!peer)
2423	2423	return SCTP_ERROR_RSRC_LOW;
2424	2424
...	...	@@ -430,7 +430,11 @@
430	430	/* The check for association's overall error counter exceeding the
431	431	* threshold is done in the state function.
432	432	*/
433		- asoc->overall_error_count++;
	433	+ /* When probing UNCONFIRMED addresses, the association overall
	434	+ * error count is NOT incremented
	435	+ */
	436	+ if (transport->state != SCTP_UNCONFIRMED)
	437	+ asoc->overall_error_count++;
434	438
435	439	if (transport->state != SCTP_INACTIVE &&
436	440	(transport->error_count++ >= transport->pathmaxrxt)) {
...	...	@@ -610,7 +614,7 @@
610	614	/* Mark the destination transport address as active if it is not so
611	615	* marked.
612	616	*/
613		- if (t->state == SCTP_INACTIVE)
	617	+ if ((t->state == SCTP_INACTIVE) \|\| (t->state == SCTP_UNCONFIRMED))
614	618	sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
615	619	SCTP_HEARTBEAT_SUCCESS);
616	620
...	...	@@ -620,6 +624,10 @@
620	624	*/
621	625	hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
622	626	sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
	627	+
	628	+ /* Update the heartbeat timer. */
	629	+ if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
	630	+ sctp_transport_hold(t);
623	631	}
624	632
625	633	/* Helper function to do a transport reset at the expiry of the hearbeat
...	...	@@ -846,6 +846,7 @@
846	846	hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t));
847	847	hbinfo.daddr = transport->ipaddr;
848	848	hbinfo.sent_at = jiffies;
	849	+ hbinfo.hb_nonce = transport->hb_nonce;
849	850
850	851	/* Send a heartbeat to our peer. */
851	852	paylen = sizeof(sctp_sender_hb_info_t);
...	...	@@ -1047,6 +1048,10 @@
1047	1048	}
1048	1049	return SCTP_DISPOSITION_DISCARD;
1049	1050	}
	1051	+
	1052	+ /* Validate the 64-bit random nonce. */
	1053	+ if (hbinfo->hb_nonce != link->hb_nonce)
	1054	+ return SCTP_DISPOSITION_DISCARD;
1050	1055
1051	1056	max_interval = link->hbinterval + link->rto;
1052	1057
...	...	@@ -49,6 +49,7 @@
49	49	*/
50	50
51	51	#include <linux/types.h>
	52	+#include <linux/random.h>
52	53	#include <net/sctp/sctp.h>
53	54	#include <net/sctp/sm.h>
54	55
...	...	@@ -85,7 +86,6 @@
85	86
86	87	peer->init_sent_count = 0;
87	88
88		- peer->state = SCTP_ACTIVE;
89	89	peer->param_flags = SPP_HB_DISABLE \|
90	90	SPP_PMTUD_ENABLE \|
91	91	SPP_SACKDELAY_ENABLE;
...	...	@@ -109,6 +109,9 @@
109	109	peer->hb_timer.function = sctp_generate_heartbeat_event;
110	110	peer->hb_timer.data = (unsigned long)peer;
111	111
	112	+ /* Initialize the 64-bit random nonce sent with heartbeat. */
	113	+ get_random_bytes(&peer->hb_nonce, sizeof(peer->hb_nonce));
	114	+
112	115	atomic_set(&peer->refcnt, 1);
113	116	peer->dead = 0;
114	117
...	...	@@ -517,7 +520,9 @@
517	520	unsigned long sctp_transport_timeout(struct sctp_transport *t)
518	521	{
519	522	unsigned long timeout;
520		- timeout = t->hbinterval + t->rto + sctp_jitter(t->rto);
	523	+ timeout = t->rto + sctp_jitter(t->rto);
	524	+ if (t->state != SCTP_UNCONFIRMED)
	525	+ timeout += t->hbinterval;
521	526	timeout += jiffies;
522	527	return timeout;
523	528	}