[SCTP] SCTP path mtu discovery support for v4 addresses.

include/net/ip.h

@@ -96,7 +96,7 @@ extern int		ip_mc_output(struct sk_buff *skb);
 extern int		ip_fragment(struct sk_buff *skb, int (*out)(struct sk_buff*));
 extern int		ip_do_nat(struct sk_buff *skb);
 extern void		ip_send_check(struct iphdr *ip);
-extern int		ip_queue_xmit(struct sk_buff *skb);
+extern int		ip_queue_xmit(struct sk_buff *skb, int ipfragok);
 extern void		ip_init(void);
 extern int		ip_append_data(struct sock *sk,
 				       int getfrag(void *from, char *to, int offset, int len,

include/net/sctp/constants.h

@@ -118,11 +118,10 @@ typedef enum {
 	SCTP_EVENT_TIMEOUT_HEARTBEAT,
 	SCTP_EVENT_TIMEOUT_SACK,
 	SCTP_EVENT_TIMEOUT_AUTOCLOSE,
-	SCTP_EVENT_TIMEOUT_PMTU_RAISE,
 
 } sctp_event_timeout_t;
 
-#define SCTP_EVENT_TIMEOUT_MAX		SCTP_EVENT_TIMEOUT_PMTU_RAISE
+#define SCTP_EVENT_TIMEOUT_MAX		SCTP_EVENT_TIMEOUT_AUTOCLOSE
 #define SCTP_NUM_TIMEOUT_TYPES		(SCTP_EVENT_TIMEOUT_MAX + 1)
 
 typedef enum {
@@ -319,10 +318,6 @@ typedef enum {
 #define SCTP_DEFAULT_TIMEOUT_SACK	((200 * HZ) / 1000)
 #define SCTP_DEFAULT_TIMEOUT_SACK_MAX	((500 * HZ) / 1000) /* 500 ms */
 
-/* How long do we wait before attempting to raise the PMTU?  */
-#define SCTP_DEFAULT_TIMEOUT_PMTU_RAISE (10 * 60 * HZ) /* 10 Minutes */
-#define SCTP_DEFAULT_TIMEOUT_PMTU_RAISE_MIN (10 * 60 * HZ) /* 10 Minutes */
-
 /* RTO.Initial              - 3  seconds
  * RTO.Min                  - 1  second
  * RTO.Max                  - 60 seconds
@@ -441,6 +436,13 @@ typedef enum {
 #define SCTP_ADDR6_PEERSUPP	0x00000004	/* IPv6 address is supported by
 						   peer */
 
+/* Reasons to retransmit. */
+typedef enum {
+	SCTP_RETRANSMIT_T3_RTX,
+	SCTP_RETRANSMIT_FAST_RTX,
+	SCTP_RETRANSMIT_PMTU_DISCOVERY,
+} sctp_retransmit_reason_t;
+
 /* Reasons to lower cwnd. */
 typedef enum {
 	SCTP_LOWER_CWND_T3_RTX,
@@ -450,4 +452,3 @@ typedef enum {
 } sctp_lower_cwnd_t;
 
 #endif /* __sctp_constants_h__ */
-

include/net/sctp/sctp.h

@@ -166,6 +166,9 @@ extern void sctp_hash_endpoint(sctp_endpoint_t *);
 extern void __sctp_hash_endpoint(sctp_endpoint_t *);
 extern void sctp_unhash_endpoint(sctp_endpoint_t *);
 extern void __sctp_unhash_endpoint(sctp_endpoint_t *);
+extern sctp_association_t *__sctp_lookup_association(const union sctp_addr *,
+						     const union sctp_addr *,
+						     sctp_transport_t **);
 
 /*
  * sctp_hashdriver.c

include/net/sctp/structs.h

@@ -238,7 +238,8 @@ struct sctp_protocol {
  * (i.e. things that depend on the address family.)
  */
 struct sctp_af {
-	int		(*queue_xmit)	(struct sk_buff *skb);
+	int		(*queue_xmit)	(struct sk_buff *skb,
+					 int ipfragok);
 	int 		(*setsockopt)	(struct sock *sk,
 					 int level,
 					 int optname,
@@ -619,6 +620,9 @@ struct SCTP_packet {
 	/* This packet contains a COOKIE-ECHO chunk. */
 	int has_cookie_echo;
 
+	/* SCTP cannot fragment this packet. So let ip fragment it. */
+	int ipfragok;
+
 	int malloced;
 };
 
@@ -936,7 +940,8 @@ int sctp_outq_set_output_handlers(struct sctp_outq *,
 				  sctp_outq_ohandler_t build,
 				  sctp_outq_ohandler_force_t force);
 void sctp_outq_restart(struct sctp_outq *);
-void sctp_retransmit(struct sctp_outq *, sctp_transport_t *, __u8);
+void sctp_retransmit(struct sctp_outq *, sctp_transport_t *,
+		     sctp_retransmit_reason_t);
 void sctp_retransmit_mark(struct sctp_outq *, sctp_transport_t *, __u8);
 
 
@@ -1626,6 +1631,8 @@ __u32 __sctp_association_get_next_tsn(sctp_association_t *);
 __u32 __sctp_association_get_tsn_block(sctp_association_t *, int);
 __u16 __sctp_association_get_next_ssn(sctp_association_t *, __u16 sid);
 
+void sctp_assoc_sync_pmtu(sctp_association_t *);
+
 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
 		        const union sctp_addr *ss2);
 sctp_chunk_t *sctp_get_ecne_prepend(sctp_association_t *asoc);

include/net/tcp.h

@@ -566,7 +566,8 @@ static inline void tcp_openreq_free(struct open_request *req)
  */
 
 struct tcp_func {
-	int			(*queue_xmit)		(struct sk_buff *skb);
+	int			(*queue_xmit)		(struct sk_buff *skb,
+							 int ipfragok);
 
 	void			(*send_check)		(struct sock *sk,
 							 struct tcphdr *th,

net/ipv4/ip_output.c

@@ -280,7 +280,7 @@ int ip_output(struct sk_buff *skb)
 		return ip_finish_output(skb);
 }
 
-int ip_queue_xmit(struct sk_buff *skb)
+int ip_queue_xmit(struct sk_buff *skb, int ipfragok)
 {
 	struct sock *sk = skb->sk;
 	struct inet_opt *inet = inet_sk(sk);
@@ -337,7 +337,7 @@ int ip_queue_xmit(struct sk_buff *skb)
 	iph = (struct iphdr *) skb_push(skb, sizeof(struct iphdr) + (opt ? opt->optlen : 0));
 	*((__u16 *)iph)	= htons((4 << 12) | (5 << 8) | (inet->tos & 0xff));
 	iph->tot_len = htons(skb->len);
-	if (ip_dont_fragment(sk, &rt->u.dst))
+	if (ip_dont_fragment(sk, &rt->u.dst) && !ipfragok)
 		iph->frag_off = htons(IP_DF);
 	else
 		iph->frag_off = 0;

net/ipv4/tcp_output.c

@@ -276,7 +276,7 @@ int tcp_transmit_skb(struct sock *sk, struct sk_buff *skb)
 
 		TCP_INC_STATS(TcpOutSegs);
 
-		err = tp->af_specific->queue_xmit(skb);
+		err = tp->af_specific->queue_xmit(skb, 0);
 		if (err <= 0)
 			return err;
 

net/ipv6/tcp_ipv6.c

@@ -60,7 +60,7 @@ static void	tcp_v6_send_check(struct sock *sk, struct tcphdr *th, int len,
 				  struct sk_buff *skb);
 
 static int	tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb);
-static int	tcp_v6_xmit(struct sk_buff *skb);
+static int	tcp_v6_xmit(struct sk_buff *skb, int ipfragok);
 
 static struct tcp_func ipv6_mapped;
 static struct tcp_func ipv6_specific;
@@ -1746,7 +1746,7 @@ static int tcp_v6_rebuild_header(struct sock *sk)
 	return 0;
 }
 
-static int tcp_v6_xmit(struct sk_buff *skb)
+static int tcp_v6_xmit(struct sk_buff *skb, int ipfragok)
 {
 	struct sock *sk = skb->sk;
 	struct inet_opt *inet = inet_sk(sk);

net/netsyms.c

@@ -248,6 +248,8 @@ EXPORT_SYMBOL(inet_unregister_protosw);
 EXPORT_SYMBOL(ip_route_output_key);
 EXPORT_SYMBOL(ip_route_input);
 EXPORT_SYMBOL(icmp_send);
+EXPORT_SYMBOL(icmp_statistics);
+EXPORT_SYMBOL(icmp_err_convert);
 EXPORT_SYMBOL(ip_options_compile);
 EXPORT_SYMBOL(ip_options_undo);
 EXPORT_SYMBOL(arp_send);

net/sctp/associola.c

@@ -948,3 +948,32 @@ sctp_transport_t *sctp_assoc_choose_shutdown_transport(sctp_association_t *asoc)
 
 	return t;
 }
+
+/* Update the association's pmtu and frag_point by going through all the
+ * transports. This routine is called when a transport's PMTU has changed.
+ */
+void sctp_assoc_sync_pmtu(sctp_association_t *asoc)
+{
+	sctp_transport_t *t;
+	struct list_head *pos;
+	__u32 pmtu = 0;
+
+	if (!asoc)
+		return;
+
+	/* Get the lowest pmtu of all the transports. */
+	list_for_each(pos, &asoc->peer.transport_addr_list) {
+		t = list_entry(pos, sctp_transport_t, transports);
+		if (!pmtu || (t->pmtu < pmtu))
+			pmtu = t->pmtu;
+	}
+
+	if (pmtu) {
+		asoc->pmtu = pmtu;
+		asoc->frag_point = pmtu - (SCTP_IP_OVERHEAD +
+					   sizeof(sctp_data_chunk_t));
+	}
+
+	SCTP_DEBUG_PRINTK("%s: asoc:%p, pmtu:%d, frag_point:%d\n",
+			  __FUNCTION__, asoc, asoc->pmtu, asoc->frag_point);
+}

net/sctp/debug.c

@@ -202,7 +202,6 @@ static const char *sctp_timer_tbl[] = {
 	"TIMEOUT_HEARTBEAT",
 	"TIMEOUT_SACK",
 	"TIMEOUT_AUTOCLOSE",
-	"TIMEOUT_PMTU_RAISE",
 };
 
 /* Lookup timer debug name. */

net/sctp/endpointola.c

@@ -152,8 +152,6 @@ sctp_endpoint_t *sctp_endpoint_init(sctp_endpoint_t *ep, sctp_protocol_t *proto,
 		SCTP_DEFAULT_TIMEOUT_SACK;
 	ep->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] = 
 		sp->autoclose * HZ;
-	ep->timeouts[SCTP_EVENT_TIMEOUT_PMTU_RAISE] = 
-		SCTP_DEFAULT_TIMEOUT_PMTU_RAISE;
 
 	/* Set up the default send/receive buffer space.  */
 

net/sctp/input.c

@@ -53,6 +53,9 @@
 #include <linux/socket.h>
 #include <linux/ip.h>
 #include <linux/time.h> /* For struct timeval */
+#include <net/ip.h>
+#include <net/icmp.h>
+#include <net/snmp.h>
 #include <net/sock.h>
 #include <net/xfrm.h>
 #include <net/sctp/sctp.h>
@@ -253,6 +256,20 @@ int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb)
         return 0;
 }
 
+/* Handle icmp frag needed error. */
+static inline void sctp_icmp_frag_needed(struct sock *sk,
+					 sctp_association_t *asoc,
+					 sctp_transport_t *transport,
+					 __u32 pmtu)
+{
+	if (!sock_owned_by_user(sk) && transport && (transport->pmtu != pmtu)) {
+		transport->pmtu = pmtu;
+		sctp_assoc_sync_pmtu(asoc);
+		sctp_retransmit(&asoc->outqueue, transport,
+				SCTP_RETRANSMIT_PMTU_DISCOVERY );
+	}
+}
+
 /*
  * This routine is called by the ICMP module when it gets some
  * sort of error condition.  If err < 0 then the socket should
@@ -268,9 +285,103 @@ int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb)
  * is probably better.
  *
  */
-void sctp_v4_err(struct sk_buff *skb, u32 info)
+void sctp_v4_err(struct sk_buff *skb, __u32 info)
 {
-	/* This should probably involve a call to SCTPhandleICMP().  */
+	struct iphdr *iph = (struct iphdr *)skb->data;
+	struct sctphdr *sh = (struct sctphdr *)(skb->data + (iph->ihl <<2));
+	int type = skb->h.icmph->type;
+	int code = skb->h.icmph->code;
+	union sctp_addr saddr, daddr;
+	struct inet_opt *inet;
+	struct sock *sk = NULL;
+	sctp_endpoint_t *ep = NULL;
+	sctp_association_t *asoc = NULL;
+	sctp_transport_t *transport;
+	int err;
+
+	if (skb->len < ((iph->ihl << 2) + 8)) {
+		ICMP_INC_STATS_BH(IcmpInErrors);
+		return;
+	}
+
+	saddr.v4.sin_family = AF_INET;
+	saddr.v4.sin_port = ntohs(sh->source);
+	memcpy(&saddr.v4.sin_addr.s_addr, &iph->saddr, sizeof(struct in_addr));	
+	daddr.v4.sin_family = AF_INET;
+	daddr.v4.sin_port = ntohs(sh->dest);
+	memcpy(&daddr.v4.sin_addr.s_addr, &iph->daddr, sizeof(struct in_addr));	
+
+	/* Look for an association that matches the incoming ICMP error 
+	 * packet.
+	 */
+	asoc = __sctp_lookup_association(&saddr, &daddr, &transport);
+	if (!asoc) {
+		/* If there is no matching association, see if it matches any
+		 * endpoint. This may happen for an ICMP error generated in 
+		 * response to an INIT_ACK. 
+		 */ 
+		ep = __sctp_rcv_lookup_endpoint(&daddr);
+		if (!ep) {
+			ICMP_INC_STATS_BH(IcmpInErrors);
+			return;
+		}
+	}
+
+	if (asoc) {
+		if (ntohl(sh->vtag) != asoc->c.peer_vtag) {
+			ICMP_INC_STATS_BH(IcmpInErrors);
+			goto out;
+		}
+		sk = asoc->base.sk;
+	} else
+		sk = ep->base.sk;
+
+	sctp_bh_lock_sock(sk);
+	/* If too many ICMPs get dropped on busy
+	 * servers this needs to be solved differently.
+	 */
+	if (sock_owned_by_user(sk))
+		NET_INC_STATS_BH(LockDroppedIcmps);
+
+	switch (type) {
+	case ICMP_PARAMETERPROB:
+		err = EPROTO;
+		break;
+	case ICMP_DEST_UNREACH:
+		if (code > NR_ICMP_UNREACH)
+			goto out_unlock;
+
+		/* PMTU discovery (RFC1191) */
+		if (code == ICMP_FRAG_NEEDED) {
+			sctp_icmp_frag_needed(sk, asoc, transport, info);
+			goto out_unlock;
+		}
+
+		err = icmp_err_convert[code].errno;
+		break;
+	case ICMP_TIME_EXCEEDED:
+		err = EHOSTUNREACH;
+		break;
+	default:
+		goto out_unlock;
+	}
+
+	inet = inet_sk(sk);
+	if (!sock_owned_by_user(sk) && inet->recverr) {
+		sk->err = err;
+		sk->error_report(sk);
+	} else {  /* Only an error on timeout */
+		sk->err_soft = err;
+	}
+
+out_unlock:
+	sctp_bh_unlock_sock(sk);
+out:
+	sock_put(sk);
+	if (asoc)
+		sctp_association_put(asoc);
+	if (ep)	
+		sctp_endpoint_put(ep);
 }
 
 /*

net/sctp/ipv6.c

@@ -98,7 +98,7 @@ static inline void sctp_v6_err(struct sk_buff *skb,
 }
 
 /* Based on tcp_v6_xmit() in tcp_ipv6.c. */
-static inline int sctp_v6_xmit(struct sk_buff *skb)
+static inline int sctp_v6_xmit(struct sk_buff *skb, int ipfragok)
 {
 	struct sock *sk = skb->sk;
 	struct ipv6_pinfo *np = inet6_sk(sk);

net/sctp/output.c

@@ -80,6 +80,7 @@ sctp_packet_t *sctp_packet_config(sctp_packet_t *packet,
 	packet->ecn_capable = ecn_capable;
 	packet->get_prepend_chunk = prepend_handler;
 	packet->has_cookie_echo = 0;
+	packet->ipfragok = 0;
 
 	/* We might need to call the prepend_handler right away.  */
 	if (packet_empty)
@@ -101,6 +102,7 @@ sctp_packet_t *sctp_packet_init(sctp_packet_t *packet,
 	packet->ecn_capable = 0;
 	packet->get_prepend_chunk = NULL;
 	packet->has_cookie_echo = 0;
+	packet->ipfragok = 0;
 	packet->malloced = 0;
 	sctp_packet_reset(packet);
 	return packet;
@@ -192,6 +194,7 @@ sctp_xmit_t sctp_packet_append_chunk(sctp_packet_t *packet, sctp_chunk_t *chunk)
 				 * transmit and rely on IP
 				 * fragmentation.
 				 */
+				packet->ipfragok = 1;
 				goto append;
 			}
 		} else { /* !packet_empty */
@@ -425,6 +428,7 @@ int sctp_packet_transmit(sctp_packet_t *packet)
 	dst = transport->dst;
 	if (!dst || dst->obsolete) {
 		sctp_transport_route(transport, NULL, sctp_sk(sk));
+		sctp_assoc_sync_pmtu(asoc);
 	}
 
 	nskb->dst = dst_clone(transport->dst);
@@ -433,7 +437,7 @@ int sctp_packet_transmit(sctp_packet_t *packet)
 
 	SCTP_DEBUG_PRINTK("***sctp_transmit_packet*** skb length %d\n",
 			  nskb->len);
-	(*transport->af_specific->queue_xmit)(nskb);
+	(*transport->af_specific->queue_xmit)(nskb, packet->ipfragok);
 out:
 	packet->size = SCTP_IP_OVERHEAD;
 	return err;

net/sctp/outqueue.c

@@ -238,8 +238,9 @@ void sctp_retransmit_mark(struct sctp_outq *q, sctp_transport_t *transport,
 		/* If we are doing retransmission due to a fast retransmit,
 		 * only the chunk's that are marked for fast retransmit
 		 * should be added to the retransmit queue.  If we are doing
-		 * retransmission due to a timeout, only the chunks that are
-		 * not yet acked should be added to the retransmit queue.
+		 * retransmission due to a timeout or pmtu discovery, only the
+		 * chunks that are not yet acked should be added to the
+		 * retransmit queue.
 		 */
 		if ((fast_retransmit && chunk->fast_retransmit) ||
 		   (!fast_retransmit && !chunk->tsn_gap_acked)) {
@@ -295,14 +296,21 @@ void sctp_retransmit_mark(struct sctp_outq *q, sctp_transport_t *transport,
  * one packet out.
  */
 void sctp_retransmit(struct sctp_outq *q, sctp_transport_t *transport,
-		     __u8 fast_retransmit)
+		     sctp_retransmit_reason_t reason)
 {
 	int error = 0;
+	__u8 fast_retransmit = 0;
 
-	if (fast_retransmit) {
-		sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_FAST_RTX);
-	} else {
+	switch(reason) {
+	case SCTP_RETRANSMIT_T3_RTX:
 		sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_T3_RTX);
+		break;
+	case SCTP_RETRANSMIT_FAST_RTX:
+		sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_FAST_RTX);
+		fast_retransmit = 1;
+		break;
+	default:
+		break;
 	}
 
 	sctp_retransmit_mark(q, transport, fast_retransmit);
@@ -1501,7 +1509,7 @@ static void sctp_check_transmitted(struct sctp_outq *q,
 
 	if (transport) {
 		if (do_fast_retransmit)
-			sctp_retransmit(q, transport, do_fast_retransmit);
+			sctp_retransmit(q, transport, SCTP_RETRANSMIT_FAST_RTX);
 
 		SCTP_DEBUG_PRINTK("%s: transport: %p, cwnd: %d, "
 				  "ssthresh: %d, flight_size: %d, pba: %d\n",

net/sctp/sm_sideeffect.c

@@ -427,7 +427,8 @@ int sctp_cmd_interpreter(sctp_event_t event_type, sctp_subtype_t subtype,
 		case SCTP_CMD_RETRAN:
 			/* Mark a transport for retransmission.  */
 			sctp_retransmit(&asoc->outqueue,
-					command->obj.transport, 0);
+					command->obj.transport,
+					SCTP_RETRANSMIT_T3_RTX);
 			break;
 
 		case SCTP_CMD_TRANSMIT:
@@ -957,12 +958,6 @@ void sctp_generate_sack_event(unsigned long data)
 	sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
 }
 
-void sctp_generate_pmtu_raise_event(unsigned long data)
-{
-	sctp_association_t *asoc = (sctp_association_t *) data;
-	sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_PMTU_RAISE);
-}
-
 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
 	NULL,
 	sctp_generate_t1_cookie_event,
@@ -974,7 +969,6 @@ sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
 	sctp_generate_heartbeat_event,
 	sctp_generate_sack_event,
 	sctp_generate_autoclose_event,
-	sctp_generate_pmtu_raise_event,
 };
 
 /********************************************************************

net/sctp/sm_statetable.c

@@ -1139,27 +1139,6 @@ sctp_sm_table_entry_t other_event_table[SCTP_NUM_OTHER_TYPES][SCTP_STATE_NUM_STA
 	{.fn = sctp_sf_timer_ignore, .name = "sctp_sf_timer_ignore"}, \
 }
 
-#define TYPE_SCTP_EVENT_TIMEOUT_PMTU_RAISE { \
-	/* SCTP_STATE_EMPTY */ \
-	{.fn = sctp_sf_bug, .name = "sctp_sf_bug"}, \
-	/* SCTP_STATE_CLOSED */ \
-	{.fn = sctp_sf_not_impl, .name = "sctp_sf_not_impl"}, \
-	/* SCTP_STATE_COOKIE_WAIT */ \
-	{.fn = sctp_sf_not_impl, .name = "sctp_sf_not_impl"}, \
-	/* SCTP_STATE_COOKIE_ECHOED */ \
-	{.fn = sctp_sf_not_impl, .name = "sctp_sf_not_impl"}, \
-	/* SCTP_STATE_ESTABLISHED */ \
-	{.fn = sctp_sf_not_impl, .name = "sctp_sf_not_impl"}, \
-	/* SCTP_STATE_SHUTDOWN_PENDING */ \
-	{.fn = sctp_sf_not_impl, .name = "sctp_sf_not_impl"}, \
-	/* SCTP_STATE_SHUTDOWN_SENT */ \
-	{.fn = sctp_sf_not_impl, .name = "sctp_sf_not_impl"}, \
-	/* SCTP_STATE_SHUTDOWN_RECEIVED */ \
-	{.fn = sctp_sf_not_impl, .name = "sctp_sf_not_impl"}, \
-	/* SCTP_STATE_SHUTDOWN_ACK_SENT */ \
-	{.fn = sctp_sf_not_impl, .name = "sctp_sf_not_impl"}, \
-}
-
 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,
@@ -1171,7 +1150,6 @@ sctp_sm_table_entry_t timeout_event_table[SCTP_NUM_TIMEOUT_TYPES][SCTP_STATE_NUM
 	TYPE_SCTP_EVENT_TIMEOUT_HEARTBEAT,
 	TYPE_SCTP_EVENT_TIMEOUT_SACK,
 	TYPE_SCTP_EVENT_TIMEOUT_AUTOCLOSE,
-	TYPE_SCTP_EVENT_TIMEOUT_PMTU_RAISE,
 };
 
 sctp_sm_table_entry_t *sctp_chunk_event_lookup(sctp_cid_t cid, sctp_state_t state)