isisd: Add log-pdu-drops log functionality

If log-pdu-drops is configured, create an INFO log that displays the PDU type and drop counts when a PDU drop is detected.

Example logs:

2023/03/30 23:54:59.749 ISIS: [VAS9N-1JNNR] PDU drop detected of type: P2P IIH. 1 Total Drops; 0 L1 IIH drops;  0 L2 IIH drops; 1 P2P IIH drops; 0 L1 LSP drops; 0 L2 LSP drops; 0 FS LSP drops; 0 L1 CSNP drops; 0 L2 CSNP drops; 0 L1 PSNP drops; 0 L2 PSNP drops.
2023/03/30 23:54:59.848 ISIS: [VAS9N-1JNNR] PDU drop detected of type: P2P IIH. 2 Total Drops; 0 L1 IIH drops;  0 L2 IIH drops; 2 P2P IIH drops; 0 L1 LSP drops; 0 L2 LSP drops; 0 FS LSP drops; 0 L1 CSNP drops; 0 L2 CSNP drops; 0 L1 PSNP drops; 0 L2 PSNP drops.

Code changes:
Add a new PDU counter function that increments the drop counter and runs the logging functionality if log-pdu-drops is configured.

Signed-off-by: Isabella de Leon <ideleon@microsoft.com>

4 files changed, 73 insertions, 17 deletions

diff --git a/isisd/isis_pdu.c b/isisd/isis_pdu.c
index d53d43ad0e..d489bb98ce 100644
--- a/isisd/isis_pdu.c
+++ b/isisd/isis_pdu.c
@@ -1654,14 +1654,14 @@ int isis_handle_pdu(struct isis_circuit *circuit, uint8_t *ssnpa)
 	if (idrp == ISO9542_ESIS) {
 		flog_err(EC_LIB_DEVELOPMENT,
 			 "No support for ES-IS packet IDRP=%hhx", idrp);
-		pdu_counter_count(circuit->area->pdu_drop_counters, pdu_type);
+		pdu_counter_count_drop(circuit->area, pdu_type);
 		return ISIS_ERROR;
 	}
 
 	if (idrp != ISO10589_ISIS) {
 		flog_err(EC_ISIS_PACKET, "Not an IS-IS packet IDRP=%hhx",
 			 idrp);
-		pdu_counter_count(circuit->area->pdu_drop_counters, pdu_type);
+		pdu_counter_count_drop(circuit->area, pdu_type);
 		return ISIS_ERROR;
 	}
 
@@ -1672,7 +1672,7 @@ int isis_handle_pdu(struct isis_circuit *circuit, uint8_t *ssnpa)
 		isis_notif_version_skew(circuit, version1, raw_pdu,
 					sizeof(raw_pdu));
 #endif /* ifndef FABRICD */
-		pdu_counter_count(circuit->area->pdu_drop_counters, pdu_type);
+		pdu_counter_count_drop(circuit->area, pdu_type);
 		return ISIS_WARNING;
 	}
 
@@ -1696,14 +1696,14 @@ int isis_handle_pdu(struct isis_circuit *circuit, uint8_t *ssnpa)
 		isis_notif_id_len_mismatch(circuit, id_len, raw_pdu,
 					   sizeof(raw_pdu));
 #endif /* ifndef FABRICD */
-		pdu_counter_count(circuit->area->pdu_drop_counters, pdu_type);
+		pdu_counter_count_drop(circuit->area, pdu_type);
 		return ISIS_ERROR;
 	}
 
 	uint8_t expected_length;
 	if (pdu_size(pdu_type, &expected_length)) {
 		zlog_warn("Unsupported ISIS PDU %hhu", pdu_type);
-		pdu_counter_count(circuit->area->pdu_drop_counters, pdu_type);
+		pdu_counter_count_drop(circuit->area, pdu_type);
 		return ISIS_WARNING;
 	}
 
@@ -1711,7 +1711,7 @@ int isis_handle_pdu(struct isis_circuit *circuit, uint8_t *ssnpa)
 		flog_err(EC_ISIS_PACKET,
 			 "Expected fixed header length = %hhu but got %hhu",
 			 expected_length, length);
-		pdu_counter_count(circuit->area->pdu_drop_counters, pdu_type);
+		pdu_counter_count_drop(circuit->area, pdu_type);
 		return ISIS_ERROR;
 	}
 
@@ -1719,7 +1719,7 @@ int isis_handle_pdu(struct isis_circuit *circuit, uint8_t *ssnpa)
 		flog_err(
 			EC_ISIS_PACKET,
 			"PDU is too short to contain fixed header of given PDU type.");
-		pdu_counter_count(circuit->area->pdu_drop_counters, pdu_type);
+		pdu_counter_count_drop(circuit->area, pdu_type);
 		return ISIS_ERROR;
 	}
 
@@ -1730,14 +1730,14 @@ int isis_handle_pdu(struct isis_circuit *circuit, uint8_t *ssnpa)
 		isis_notif_version_skew(circuit, version2, raw_pdu,
 					sizeof(raw_pdu));
 #endif /* ifndef FABRICD */
-		pdu_counter_count(circuit->area->pdu_drop_counters, pdu_type);
+		pdu_counter_count_drop(circuit->area, pdu_type);
 		return ISIS_WARNING;
 	}
 
 	if (circuit->is_passive) {
 		zlog_warn("Received ISIS PDU on passive circuit %s",
 			  circuit->interface->name);
-		pdu_counter_count(circuit->area->pdu_drop_counters, pdu_type);
+		pdu_counter_count_drop(circuit->area, pdu_type);
 		return ISIS_WARNING;
 	}
 
@@ -1756,7 +1756,7 @@ int isis_handle_pdu(struct isis_circuit *circuit, uint8_t *ssnpa)
 		isis_notif_max_area_addr_mismatch(circuit, max_area_addrs,
 						  raw_pdu, sizeof(raw_pdu));
 #endif /* ifndef FABRICD */
-		pdu_counter_count(circuit->area->pdu_drop_counters, pdu_type);
+		pdu_counter_count_drop(circuit->area, pdu_type);
 		return ISIS_ERROR;
 	}
 
@@ -1765,8 +1765,7 @@ int isis_handle_pdu(struct isis_circuit *circuit, uint8_t *ssnpa)
 	case L2_LAN_HELLO:
 	case P2P_HELLO:
 		if (fabricd && pdu_type != P2P_HELLO) {
-			pdu_counter_count(circuit->area->pdu_drop_counters,
-					  pdu_type);
+			pdu_counter_count_drop(circuit->area, pdu_type);
 			return ISIS_ERROR;
 		}
 
@@ -1777,8 +1776,7 @@ int isis_handle_pdu(struct isis_circuit *circuit, uint8_t *ssnpa)
 	case FS_LINK_STATE:
 		if (fabricd && pdu_type != L2_LINK_STATE &&
 		    pdu_type != FS_LINK_STATE) {
-			pdu_counter_count(circuit->area->pdu_drop_counters,
-					  pdu_type);
+			pdu_counter_count_drop(circuit->area, pdu_type);
 			return ISIS_ERROR;
 		}
 
@@ -1791,12 +1789,12 @@ int isis_handle_pdu(struct isis_circuit *circuit, uint8_t *ssnpa)
 		retval = process_snp(pdu_type, circuit, ssnpa);
 		break;
 	default:
-		pdu_counter_count(circuit->area->pdu_drop_counters, pdu_type);
+		pdu_counter_count_drop(circuit->area, pdu_type);
 		return ISIS_ERROR;
 	}
 
 	if (retval != ISIS_OK)
-		pdu_counter_count(circuit->area->pdu_drop_counters, pdu_type);
+		pdu_counter_count_drop(circuit->area, pdu_type);
 
 	return retval;
 }
@@ -2554,3 +2552,37 @@ out:
 		isis_tx_queue_del(circuit->tx_queue, lsp);
 	}
 }
+
+void isis_log_pdu_drops(struct isis_area *area, const char *pdu_type)
+{
+	uint64_t total_drops = 0;
+
+	for (int i = 0; i < PDU_COUNTER_SIZE; i++) {
+		if (!area->pdu_drop_counters[i])
+			continue;
+		total_drops += area->pdu_drop_counters[i];
+	}
+
+	zlog_info("PDU drop detected of type: %s. %" PRIu64
+		  " Total Drops; %" PRIu64 " L1 IIH drops;  %" PRIu64
+		  " L2 IIH drops; %" PRIu64 " P2P IIH drops; %" PRIu64
+		  " L1 LSP drops; %" PRIu64 " L2 LSP drops; %" PRIu64
+		  " FS LSP drops; %" PRIu64 " L1 CSNP drops; %" PRIu64
+		  " L2 CSNP drops; %" PRIu64 " L1 PSNP drops; %" PRIu64
+		  " L2 PSNP drops.",
+		  pdu_type, total_drops,
+		  pdu_counter_get_count(area->pdu_drop_counters, L1_LAN_HELLO),
+		  pdu_counter_get_count(area->pdu_drop_counters, L2_LAN_HELLO),
+		  pdu_counter_get_count(area->pdu_drop_counters, P2P_HELLO),
+		  pdu_counter_get_count(area->pdu_drop_counters, L1_LINK_STATE),
+		  pdu_counter_get_count(area->pdu_drop_counters, L2_LINK_STATE),
+		  pdu_counter_get_count(area->pdu_drop_counters, FS_LINK_STATE),
+		  pdu_counter_get_count(area->pdu_drop_counters,
+					L1_COMPLETE_SEQ_NUM),
+		  pdu_counter_get_count(area->pdu_drop_counters,
+					L2_COMPLETE_SEQ_NUM),
+		  pdu_counter_get_count(area->pdu_drop_counters,
+					L1_PARTIAL_SEQ_NUM),
+		  pdu_counter_get_count(area->pdu_drop_counters,
+					L2_PARTIAL_SEQ_NUM));
+}
diff --git a/isisd/isis_pdu.h b/isisd/isis_pdu.h
index ccd89a70f1..5303c61d38 100644
--- a/isisd/isis_pdu.h
+++ b/isisd/isis_pdu.h
@@ -206,4 +206,6 @@ void send_lsp(struct isis_circuit *circuit,
 void fill_fixed_hdr(uint8_t pdu_type, struct stream *stream);
 int send_hello(struct isis_circuit *circuit, int level);
 int isis_handle_pdu(struct isis_circuit *circuit, uint8_t *ssnpa);
+void isis_log_pdu_drops(struct isis_area *area, const char *pdu_type);
+
 #endif /* _ZEBRA_ISIS_PDU_H */
diff --git a/isisd/isis_pdu_counter.c b/isisd/isis_pdu_counter.c
index 9d07b5e598..a3605a32a1 100644
--- a/isisd/isis_pdu_counter.c
+++ b/isisd/isis_pdu_counter.c
@@ -8,10 +8,10 @@
 
 #include "vty.h"
 
-#include "isisd/isis_pdu_counter.h"
 #include "isisd/isisd.h"
 #include "isisd/isis_circuit.h"
 #include "isisd/isis_pdu.h"
+#include "isisd/isis_pdu_counter.h"
 
 static int pdu_type_to_counter_index(uint8_t pdu_type)
 {
@@ -91,3 +91,23 @@ void pdu_counter_print(struct vty *vty, const char *prefix,
 			pdu_counter_index_to_name(i), counter[i]);
 	}
 }
+
+void pdu_counter_count_drop(struct isis_area *area, uint8_t pdu_type)
+{
+	pdu_counter_count(area->pdu_drop_counters, pdu_type);
+
+	if (area->log_pdu_drops) {
+		isis_log_pdu_drops(
+			area, pdu_counter_index_to_name(
+				      pdu_type_to_counter_index(pdu_type)));
+	}
+}
+
+uint64_t pdu_counter_get_count(pdu_counter_t counter, uint8_t pdu_type)
+{
+	int index = pdu_type_to_counter_index(pdu_type);
+
+	if (index < 0)
+		return -1;
+	return counter[index];
+}
diff --git a/isisd/isis_pdu_counter.h b/isisd/isis_pdu_counter.h
index c53c47368f..5c35b4fb51 100644
--- a/isisd/isis_pdu_counter.h
+++ b/isisd/isis_pdu_counter.h
@@ -24,5 +24,7 @@ typedef uint64_t pdu_counter_t[PDU_COUNTER_SIZE];
 void pdu_counter_print(struct vty *vty, const char *prefix,
 		       pdu_counter_t counter);
 void pdu_counter_count(pdu_counter_t counter, uint8_t pdu_type);
+void pdu_counter_count_drop(struct isis_area *area, uint8_t pdu_type);
+uint64_t pdu_counter_get_count(pdu_counter_t counter, uint8_t pdu_type);
 
 #endif