[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>

5 files changed, 44 insertions, 6 deletions

diff --git a/net/sctp/input.c b/net/sctp/input.c
index 42b66e74bbb..8a34d95602c 100644
--- a/net/sctp/input.c
+++ b/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;
 
diff --git a/net/sctp/inqueue.c b/net/sctp/inqueue.c
index cf0c767d43a..cf6deed7e84 100644
--- a/net/sctp/inqueue.c
+++ b/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);
 }
 
diff --git a/net/sctp/outqueue.c b/net/sctp/outqueue.c
index 30b710c54e6..37074a39ecb 100644
--- a/net/sctp/outqueue.c
+++ b/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);
diff --git a/net/sctp/proc.c b/net/sctp/proc.c
index 5b3b0e0ae7e..a356d8d310a 100644
--- a/net/sctp/proc.c
+++ b/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);
diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index 5b5ae795832..32f57f42af9 100644
--- a/net/sctp/sm_statefuns.c
+++ b/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