[SCTP]: Extend /proc/net/sctp/snmp to provide more statistics.

This patch adds more statistics info under /proc/net/sctp/snmp
that should be useful for debugging. The additional events that
are counted now include timer expirations, retransmits, packet
and data chunk discards.

The Data chunk discards include all the cases where a data chunk
is discarded including high tsn, bad stream, dup tsn and the most
useful one(out of receive buffer/rwnd).

Also moved the SCTP MIB data structures from the generic include
directories to include/sctp/sctp.h.

Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/snmp.h

@@ -160,39 +160,6 @@ enum
 	__UDP_MIB_MAX
 };
 
-/* sctp mib definitions */
-/*
- * draft-ietf-sigtran-sctp-mib-07.txt
- */
-enum
-{
-	SCTP_MIB_NUM = 0,
-	SCTP_MIB_CURRESTAB,			/* CurrEstab */
-	SCTP_MIB_ACTIVEESTABS,			/* ActiveEstabs */
-	SCTP_MIB_PASSIVEESTABS,			/* PassiveEstabs */
-	SCTP_MIB_ABORTEDS,			/* Aborteds */
-	SCTP_MIB_SHUTDOWNS,			/* Shutdowns */
-	SCTP_MIB_OUTOFBLUES,			/* OutOfBlues */
-	SCTP_MIB_CHECKSUMERRORS,		/* ChecksumErrors */
-	SCTP_MIB_OUTCTRLCHUNKS,			/* OutCtrlChunks */
-	SCTP_MIB_OUTORDERCHUNKS,		/* OutOrderChunks */
-	SCTP_MIB_OUTUNORDERCHUNKS,		/* OutUnorderChunks */
-	SCTP_MIB_INCTRLCHUNKS,			/* InCtrlChunks */
-	SCTP_MIB_INORDERCHUNKS,			/* InOrderChunks */
-	SCTP_MIB_INUNORDERCHUNKS,		/* InUnorderChunks */
-	SCTP_MIB_FRAGUSRMSGS,			/* FragUsrMsgs */
-	SCTP_MIB_REASMUSRMSGS,			/* ReasmUsrMsgs */
-	SCTP_MIB_OUTSCTPPACKS,			/* OutSCTPPacks */
-	SCTP_MIB_INSCTPPACKS,			/* InSCTPPacks */
-	SCTP_MIB_RTOALGORITHM,			/* RtoAlgorithm */
-	SCTP_MIB_RTOMIN,			/* RtoMin */
-	SCTP_MIB_RTOMAX,			/* RtoMax */
-	SCTP_MIB_RTOINITIAL,			/* RtoInitial */
-	SCTP_MIB_VALCOOKIELIFE,			/* ValCookieLife */
-	SCTP_MIB_MAXINITRETR,			/* MaxInitRetr */
-	__SCTP_MIB_MAX
-};
-
 /* linux mib definitions */
 enum
 {

include/net/sctp/sctp.h

@@ -216,6 +216,50 @@ DECLARE_SNMP_STAT(struct sctp_mib, sctp_statistics);
 
 #endif /* !TEST_FRAME */
 
+/* sctp mib definitions */
+enum
+{
+	SCTP_MIB_NUM = 0,
+	SCTP_MIB_CURRESTAB,			/* CurrEstab */
+	SCTP_MIB_ACTIVEESTABS,			/* ActiveEstabs */
+	SCTP_MIB_PASSIVEESTABS,			/* PassiveEstabs */
+	SCTP_MIB_ABORTEDS,			/* Aborteds */
+	SCTP_MIB_SHUTDOWNS,			/* Shutdowns */
+	SCTP_MIB_OUTOFBLUES,			/* OutOfBlues */
+	SCTP_MIB_CHECKSUMERRORS,		/* ChecksumErrors */
+	SCTP_MIB_OUTCTRLCHUNKS,			/* OutCtrlChunks */
+	SCTP_MIB_OUTORDERCHUNKS,		/* OutOrderChunks */
+	SCTP_MIB_OUTUNORDERCHUNKS,		/* OutUnorderChunks */
+	SCTP_MIB_INCTRLCHUNKS,			/* InCtrlChunks */
+	SCTP_MIB_INORDERCHUNKS,			/* InOrderChunks */
+	SCTP_MIB_INUNORDERCHUNKS,		/* InUnorderChunks */
+	SCTP_MIB_FRAGUSRMSGS,			/* FragUsrMsgs */
+	SCTP_MIB_REASMUSRMSGS,			/* ReasmUsrMsgs */
+	SCTP_MIB_OUTSCTPPACKS,			/* OutSCTPPacks */
+	SCTP_MIB_INSCTPPACKS,			/* InSCTPPacks */
+	SCTP_MIB_T1_INIT_EXPIREDS,
+	SCTP_MIB_T1_COOKIE_EXPIREDS,
+	SCTP_MIB_T2_SHUTDOWN_EXPIREDS,
+	SCTP_MIB_T3_RTX_EXPIREDS,
+	SCTP_MIB_T4_RTO_EXPIREDS,
+	SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS,
+	SCTP_MIB_DELAY_SACK_EXPIREDS,
+	SCTP_MIB_AUTOCLOSE_EXPIREDS,
+	SCTP_MIB_T3_RETRANSMITS,
+	SCTP_MIB_PMTUD_RETRANSMITS,
+	SCTP_MIB_FAST_RETRANSMITS,
+	SCTP_MIB_IN_PKT_SOFTIRQ,
+	SCTP_MIB_IN_PKT_BACKLOG,
+	SCTP_MIB_IN_PKT_DISCARDS,
+	SCTP_MIB_IN_DATA_CHUNK_DISCARDS,
+	__SCTP_MIB_MAX
+};
+
+#define SCTP_MIB_MAX    __SCTP_MIB_MAX
+struct sctp_mib {
+        unsigned long   mibs[SCTP_MIB_MAX];
+} __SNMP_MIB_ALIGN__;
+
 
 /* Print debugging messages.  */
 #if SCTP_DEBUG

include/net/snmp.h

@@ -100,12 +100,6 @@ struct udp_mib {
 	unsigned long	mibs[UDP_MIB_MAX];
 } __SNMP_MIB_ALIGN__;
 
-/* SCTP */
-#define SCTP_MIB_MAX	__SCTP_MIB_MAX
-struct sctp_mib {
-	unsigned long	mibs[SCTP_MIB_MAX];
-} __SNMP_MIB_ALIGN__;
-
 /* Linux */
 #define LINUX_MIB_MAX	__LINUX_MIB_MAX
 struct linux_mib {

net/sctp/input.c

@@ -255,10 +255,13 @@ int sctp_rcv(struct sk_buff *skb)
 	 */
 	sctp_bh_lock_sock(sk);
 
-	if (sock_owned_by_user(sk))
+	if (sock_owned_by_user(sk)) {
+		SCTP_INC_STATS_BH(SCTP_MIB_IN_PKT_BACKLOG);
 		sctp_add_backlog(sk, skb);
-	else
+	} else {
+		SCTP_INC_STATS_BH(SCTP_MIB_IN_PKT_SOFTIRQ);
 		sctp_inq_push(&chunk->rcvr->inqueue, chunk);
+	}
 
 	sctp_bh_unlock_sock(sk);
 
@@ -271,6 +274,7 @@ int sctp_rcv(struct sk_buff *skb)
 	return 0;
 
 discard_it:
+	SCTP_INC_STATS_BH(SCTP_MIB_IN_PKT_DISCARDS);
 	kfree_skb(skb);
 	return 0;
 

net/sctp/inqueue.c

@@ -87,7 +87,7 @@ void sctp_inq_free(struct sctp_inq *queue)
 /* Put a new packet in an SCTP inqueue.
  * We assume that packet->sctp_hdr is set and in host byte order.
  */
-void sctp_inq_push(struct sctp_inq *q, struct sctp_chunk *packet)
+void sctp_inq_push(struct sctp_inq *q, struct sctp_chunk *chunk)
 {
 	/* Directly call the packet handling routine. */
 
@@ -96,7 +96,7 @@ void sctp_inq_push(struct sctp_inq *q, struct sctp_chunk *packet)
 	 * Eventually, we should clean up inqueue to not rely
 	 * on the BH related data structures.
 	 */
-	list_add_tail(&packet->list, &q->in_chunk_list);
+	list_add_tail(&chunk->list, &q->in_chunk_list);
 	q->immediate.func(q->immediate.data);
 }
 

net/sctp/outqueue.c

@@ -467,6 +467,7 @@ void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
 
 	switch(reason) {
 	case SCTP_RTXR_T3_RTX:
+		SCTP_INC_STATS(SCTP_MIB_T3_RETRANSMITS);
 		sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_T3_RTX);
 		/* Update the retran path if the T3-rtx timer has expired for
 		 * the current retran path.
@@ -475,12 +476,15 @@ void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport,
 			sctp_assoc_update_retran_path(transport->asoc);
 		break;
 	case SCTP_RTXR_FAST_RTX:
+		SCTP_INC_STATS(SCTP_MIB_FAST_RETRANSMITS);
 		sctp_transport_lower_cwnd(transport, SCTP_LOWER_CWND_FAST_RTX);
 		fast_retransmit = 1;
 		break;
 	case SCTP_RTXR_PMTUD:
-	default:
+		SCTP_INC_STATS(SCTP_MIB_PMTUD_RETRANSMITS);
 		break;
+	default:
+		BUG();
 	}
 
 	sctp_retransmit_mark(q, transport, fast_retransmit);

net/sctp/proc.c

@@ -57,6 +57,21 @@ static struct snmp_mib sctp_snmp_list[] = {
 	SNMP_MIB_ITEM("SctpReasmUsrMsgs", SCTP_MIB_REASMUSRMSGS),
 	SNMP_MIB_ITEM("SctpOutSCTPPacks", SCTP_MIB_OUTSCTPPACKS),
 	SNMP_MIB_ITEM("SctpInSCTPPacks", SCTP_MIB_INSCTPPACKS),
+	SNMP_MIB_ITEM("SctpT1InitExpireds", SCTP_MIB_T1_INIT_EXPIREDS),
+	SNMP_MIB_ITEM("SctpT1CookieExpireds", SCTP_MIB_T1_COOKIE_EXPIREDS),
+	SNMP_MIB_ITEM("SctpT2ShutdownExpireds", SCTP_MIB_T2_SHUTDOWN_EXPIREDS),
+	SNMP_MIB_ITEM("SctpT3RtxExpireds", SCTP_MIB_T3_RTX_EXPIREDS),
+	SNMP_MIB_ITEM("SctpT4RtoExpireds", SCTP_MIB_T4_RTO_EXPIREDS),
+	SNMP_MIB_ITEM("SctpT5ShutdownGuardExpireds", SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS),
+	SNMP_MIB_ITEM("SctpDelaySackExpireds", SCTP_MIB_DELAY_SACK_EXPIREDS),
+	SNMP_MIB_ITEM("SctpAutocloseExpireds", SCTP_MIB_AUTOCLOSE_EXPIREDS),
+	SNMP_MIB_ITEM("SctpT3Retransmits", SCTP_MIB_T3_RETRANSMITS),
+	SNMP_MIB_ITEM("SctpPmtudRetransmits", SCTP_MIB_PMTUD_RETRANSMITS),
+	SNMP_MIB_ITEM("SctpFastRetransmits", SCTP_MIB_FAST_RETRANSMITS),
+	SNMP_MIB_ITEM("SctpInPktSoftirq", SCTP_MIB_IN_PKT_SOFTIRQ),
+	SNMP_MIB_ITEM("SctpInPktBacklog", SCTP_MIB_IN_PKT_BACKLOG),
+	SNMP_MIB_ITEM("SctpInPktDiscards", SCTP_MIB_IN_PKT_DISCARDS),
+	SNMP_MIB_ITEM("SctpInDataChunkDiscards", SCTP_MIB_IN_DATA_CHUNK_DISCARDS),
 	SNMP_MIB_SENTINEL
 };
 
@@ -328,8 +343,8 @@ static int sctp_assocs_seq_show(struct seq_file *seq, void *v)
 			   "%8p %8p %-3d %-3d %-2d %-4d %4d %8d %8d %7d %5lu %-5d %5d ",
 			   assoc, sk, sctp_sk(sk)->type, sk->sk_state,
 			   assoc->state, hash, assoc->assoc_id,
-			   (sk->sk_rcvbuf - assoc->rwnd),
 			   assoc->sndbuf_used,
+			   (sk->sk_rcvbuf - assoc->rwnd),
 			   sock_i_uid(sk), sock_i_ino(sk),
 			   epb->bind_addr.port,
 			   assoc->peer.port);

net/sctp/sm_statefuns.c

@@ -2663,9 +2663,11 @@ sctp_disposition_t sctp_sf_eat_data_6_2(const struct sctp_endpoint *ep,
 		break;
 	case SCTP_IERROR_HIGH_TSN:
 	case SCTP_IERROR_BAD_STREAM:
+		SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
 		goto discard_noforce;
 	case SCTP_IERROR_DUP_TSN:
 	case SCTP_IERROR_IGNORE_TSN:
+		SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
 		goto discard_force;
 	case SCTP_IERROR_NO_DATA:
 		goto consume;
@@ -3652,6 +3654,7 @@ sctp_disposition_t sctp_sf_pdiscard(const struct sctp_endpoint *ep,
 				    void *arg,
 				    sctp_cmd_seq_t *commands)
 {
+	SCTP_INC_STATS(SCTP_MIB_IN_PKT_DISCARDS);
 	sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
 
 	return SCTP_DISPOSITION_CONSUME;
@@ -4548,6 +4551,8 @@ sctp_disposition_t sctp_sf_do_6_3_3_rtx(const struct sctp_endpoint *ep,
 {
 	struct sctp_transport *transport = arg;
 
+	SCTP_INC_STATS(SCTP_MIB_T3_RTX_EXPIREDS);
+
 	if (asoc->overall_error_count >= asoc->max_retrans) {
 		sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
 				SCTP_ERROR(ETIMEDOUT));
@@ -4616,6 +4621,7 @@ sctp_disposition_t sctp_sf_do_6_2_sack(const struct sctp_endpoint *ep,
 				       void *arg,
 				       sctp_cmd_seq_t *commands)
 {
+	SCTP_INC_STATS(SCTP_MIB_DELAY_SACK_EXPIREDS);
 	sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
 	return SCTP_DISPOSITION_CONSUME;
 }
@@ -4650,6 +4656,7 @@ sctp_disposition_t sctp_sf_t1_init_timer_expire(const struct sctp_endpoint *ep,
 	int attempts = asoc->init_err_counter + 1;
 
 	SCTP_DEBUG_PRINTK("Timer T1 expired (INIT).\n");
+	SCTP_INC_STATS(SCTP_MIB_T1_INIT_EXPIREDS);
 
 	if (attempts <= asoc->max_init_attempts) {
 		bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
@@ -4709,6 +4716,7 @@ sctp_disposition_t sctp_sf_t1_cookie_timer_expire(const struct sctp_endpoint *ep
 	int attempts = asoc->init_err_counter + 1;
 
 	SCTP_DEBUG_PRINTK("Timer T1 expired (COOKIE-ECHO).\n");
+	SCTP_INC_STATS(SCTP_MIB_T1_COOKIE_EXPIREDS);
 
 	if (attempts <= asoc->max_init_attempts) {
 		repl = sctp_make_cookie_echo(asoc, NULL);
@@ -4753,6 +4761,8 @@ sctp_disposition_t sctp_sf_t2_timer_expire(const struct sctp_endpoint *ep,
 	struct sctp_chunk *reply = NULL;
 
 	SCTP_DEBUG_PRINTK("Timer T2 expired.\n");
+	SCTP_INC_STATS(SCTP_MIB_T2_SHUTDOWN_EXPIREDS);
+
 	if (asoc->overall_error_count >= asoc->max_retrans) {
 		sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
 				SCTP_ERROR(ETIMEDOUT));
@@ -4814,6 +4824,8 @@ sctp_disposition_t sctp_sf_t4_timer_expire(
 	struct sctp_chunk *chunk = asoc->addip_last_asconf;
 	struct sctp_transport *transport = chunk->transport;
 
+	SCTP_INC_STATS(SCTP_MIB_T4_RTO_EXPIREDS);
+
 	/* ADDIP 4.1 B1) Increment the error counters and perform path failure
 	 * detection on the appropriate destination address as defined in
 	 * RFC2960 [5] section 8.1 and 8.2.
@@ -4880,6 +4892,7 @@ sctp_disposition_t sctp_sf_t5_timer_expire(const struct sctp_endpoint *ep,
 	struct sctp_chunk *reply = NULL;
 
 	SCTP_DEBUG_PRINTK("Timer T5 expired.\n");
+	SCTP_INC_STATS(SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS);
 
 	reply = sctp_make_abort(asoc, NULL, 0);
 	if (!reply)
@@ -4910,6 +4923,8 @@ sctp_disposition_t sctp_sf_autoclose_timer_expire(
 {
 	int disposition;
 
+	SCTP_INC_STATS(SCTP_MIB_AUTOCLOSE_EXPIREDS);
+
 	/* From 9.2 Shutdown of an Association
 	 * Upon receipt of the SHUTDOWN primitive from its upper
 	 * layer, the endpoint enters SHUTDOWN-PENDING state and