stp: Track BPDU tx and rx counts.

When debugging spanning tree, it's useful to have counters about how
many BPDUs have been sent and received.  This commit keeps track of
these counters and stores them in a new "statistics" column of the Port
table.

Feature #8103

2 files changed, 23 insertions, 0 deletions

diff --git a/lib/stp.c b/lib/stp.c
index 94b9a4b5..62c2ea8a 100644
--- a/lib/stp.c
+++ b/lib/stp.c
@@ -93,6 +93,10 @@ struct stp_port {
     struct stp_timer forward_delay_timer; /* 8.5.6.2: State change timer. */
     struct stp_timer hold_timer;        /* 8.5.6.3: BPDU rate limit timer. */
 
+    int tx_count;                   /* Number of BPDUs transmitted. */
+    int rx_count;                   /* Number of valid BPDUs received. */
+    int error_count;                /* Number of bad BPDUs received. */
+
     bool state_changed;
 };
 
@@ -562,6 +566,7 @@ stp_received_bpdu(struct stp_port *p, const void *bpdu, size_t bpdu_size)
 
     if (bpdu_size < sizeof(struct stp_bpdu_header)) {
         VLOG_WARN("%s: received runt %zu-byte BPDU", stp->name, bpdu_size);
+        p->error_count++;
         return;
     }
 
@@ -569,6 +574,7 @@ stp_received_bpdu(struct stp_port *p, const void *bpdu, size_t bpdu_size)
     if (header->protocol_id != htons(STP_PROTOCOL_ID)) {
         VLOG_WARN("%s: received BPDU with unexpected protocol ID %"PRIu16,
                   stp->name, ntohs(header->protocol_id));
+        p->error_count++;
         return;
     }
     if (header->protocol_version != STP_PROTOCOL_VERSION) {
@@ -581,6 +587,7 @@ stp_received_bpdu(struct stp_port *p, const void *bpdu, size_t bpdu_size)
         if (bpdu_size < sizeof(struct stp_config_bpdu)) {
             VLOG_WARN("%s: received config BPDU with invalid size %zu",
                       stp->name, bpdu_size);
+            p->error_count++;
             return;
         }
         stp_received_config_bpdu(stp, p, bpdu);
@@ -590,6 +597,7 @@ stp_received_bpdu(struct stp_port *p, const void *bpdu, size_t bpdu_size)
         if (bpdu_size != sizeof(struct stp_tcn_bpdu)) {
             VLOG_WARN("%s: received TCN BPDU with invalid size %zu",
                       stp->name, bpdu_size);
+            p->error_count++;
             return;
         }
         stp_received_tcn_bpdu(stp, p);
@@ -598,8 +606,10 @@ stp_received_bpdu(struct stp_port *p, const void *bpdu, size_t bpdu_size)
     default:
         VLOG_WARN("%s: received BPDU of unexpected type %"PRIu8,
                   stp->name, header->bpdu_type);
+        p->error_count++;
         return;
     }
+    p->rx_count++;
 }
 
 /* Returns the STP entity in which 'p' is nested. */
@@ -667,6 +677,15 @@ stp_port_get_role(const struct stp_port *p)
     }
 }
 
+/* Retrieves BPDU transmit and receive counts for 'p'. */
+void stp_port_get_counts(const struct stp_port *p,
+                         int *tx_count, int *rx_count, int *error_count)
+{
+    *tx_count = p->tx_count;
+    *rx_count = p->rx_count;
+    *error_count = p->error_count;
+}
+
 /* Disables STP on port 'p'. */
 void
 stp_port_disable(struct stp_port *p)
@@ -1185,6 +1204,7 @@ stp_initialize_port(struct stp_port *p, enum stp_state state)
     stp_stop_timer(&p->message_age_timer);
     stp_stop_timer(&p->forward_delay_timer);
     stp_stop_timer(&p->hold_timer);
+    p->tx_count = p->rx_count = p->error_count = 0;
 }
 
 static void
@@ -1299,4 +1319,5 @@ stp_send_bpdu(struct stp_port *p, const void *bpdu, size_t bpdu_size)
     llc->llc_cntl = STP_LLC_CNTL;
 
     p->stp->send_bpdu(pkt, stp_port_no(p), p->stp->aux);
+    p->tx_count++;
 }
diff --git a/lib/stp.h b/lib/stp.h
index 54f7f5b4..ec29d9a7 100644
--- a/lib/stp.h
+++ b/lib/stp.h
@@ -136,6 +136,8 @@ int stp_port_no(const struct stp_port *);
 int stp_port_get_id(const struct stp_port *);
 enum stp_state stp_port_get_state(const struct stp_port *);
 enum stp_role stp_port_get_role(const struct stp_port *);
+void stp_port_get_counts(const struct stp_port *,
+                         int *tx_count, int *rx_count, int *error_count);
 void stp_port_enable(struct stp_port *);
 void stp_port_disable(struct stp_port *);
 void stp_port_set_priority(struct stp_port *, uint8_t new_priority);