Development

CHANGELOG.md

@@ -1,4 +1,11 @@
 # Change Log
+- 0.0.8
+    - Added 4-byte ASN support (RFC 6793)
+    - Added COMMUNITY path attribute parsing (RFC 1997)
+    - Added LARGE_COMMUNITY path attribute parsing (RFC 8092)
+    - Added timestamp to log messages
+    - Fixed header include guard issue causing build failures in CI
+
 - 0.0.7
     - Added automatic reconnection with exponential backoff (`-R` flag)
     - Added output queue with dedicated writer thread to prevent keepalive stalls on slow stdout

README.md

@@ -21,13 +21,13 @@ BGPSee is a multi-threaded BGP client for the CLI. Its goal is to allow you to q
 
 # Version
 
-Current version is **0.0.7**
+Current version is **0.0.8**
 
-Major changes from **0.0.6** to **0.0.7**:
-- Automatic reconnection with exponential backoff (`-R` flag)
-- Output queue for reliable keepalive handling on slow connections
-- Hold time negotiation per RFC 4271
-- FSM race condition fixes 
+Major changes from **0.0.7** to **0.0.8**:
+- 4-byte ASN support (RFC 6793)
+- COMMUNITY path attribute parsing (RFC 1997)
+- LARGE_COMMUNITY path attribute parsing (RFC 8092)
+- Timestamp added to log messages
 
 See the [CHANGELOG](CHANGELOG.md) for further information.
 

src/bgp.c

@@ -26,7 +26,7 @@
 
 struct bgp_instance {
     uint8_t version;
-    uint16_t local_asn;
+    uint32_t local_asn;
     uint32_t local_rid;
     int n_peers;
     struct bgp_peer *peers[MAX_BGP_PEERS];
@@ -162,7 +162,7 @@ int setup_reconnect_timer(struct bgp_peer *peer) {
 */
 
 
-struct bgp_instance *create_bgp_instance(uint16_t local_asn, uint32_t local_rid, uint8_t version) {
+struct bgp_instance *create_bgp_instance(uint32_t local_asn, uint32_t local_rid, uint8_t version) {
     struct bgp_instance *i;
 
     log_print(LOG_DEBUG, "Creating new peer (ASN %d, RID: %d, Version: %d)\n", local_asn, local_rid, version);
@@ -239,7 +239,7 @@ struct bgp_peer *get_peer_from_instance(struct bgp_instance *i, unsigned int id)
 
 
 //TODO: Need to fix unsigned here, as we need to be able to signal failure of the function
-unsigned int create_bgp_peer(struct bgp_instance *i, const char *peer_ip, const uint16_t peer_asn, const char *peer_name) {
+unsigned int create_bgp_peer(struct bgp_instance *i, const char *peer_ip, const uint32_t peer_asn, const char *peer_name) {
     struct bgp_peer *peer;
     unsigned int new_id;
 
@@ -309,6 +309,7 @@ unsigned int create_bgp_peer(struct bgp_instance *i, const char *peer_ip, const
     peer->socket.fd = -1;
 
     peer->peer_asn = peer_asn;
+    peer->four_octet_asn = 0;
 
     //Init the stdout lock and the output function
     pthread_mutex_init(&peer->stdout_lock, NULL);
@@ -625,7 +626,7 @@ void *bgp_peer_thread(void *param) {
             //Did we receive messages?
             if (peer->socket.fd >= 0 && FD_ISSET(peer->socket.fd, set)) {
                 log_print(LOG_DEBUG, "Calling recv_msg() on socket\n");
-                message = recv_msg(peer->socket.fd);
+                message = recv_msg(peer);
 
                 if (!message) {
                     log_print(LOG_ERROR, "recv_msg() errored\n");
@@ -789,7 +790,7 @@ int fsm_state_idle(struct bgp_peer *peer, fd_set *set) {
     //Start the ConnectRetryTimer
     start_timer(peer->local_timers, ConnectRetryTimer);
 
-    log_print(LOG_INFO, "Opening connection to %s,%d (%s)\n", peer->peer_ip, peer->peer_asn, peer->name);
+    log_print(LOG_INFO, "Opening connection to %s,%u (%s)\n", peer->peer_ip, peer->peer_asn, peer->name);
     peer->socket.fd = tcp_connect(peer->peer_ip, "179", peer->source_ip);
 
     if (peer->socket.fd < 0) {
@@ -814,6 +815,7 @@ int fsm_state_idle(struct bgp_peer *peer, fd_set *set) {
 
 int fsm_state_connect(struct bgp_peer *peer) {
     struct bgp_capabilities *caps;
+    uint16_t open_asn;
 
     log_print(LOG_DEBUG, "Peer %s FSM state: CONNECT\n", peer->name);
 
@@ -823,12 +825,14 @@ int fsm_state_connect(struct bgp_peer *peer) {
         bgp_capabilities_add_route_refresh(caps);
         bgp_capabilities_add_mp_ext(caps, BGP_AFI_IPV4, BGP_SAFI_UNICAST);
         bgp_capabilities_add_mp_ext(caps, BGP_AFI_IPV6, BGP_SAFI_UNICAST);
+        bgp_capabilities_add_four_octet_asn(caps, *peer->local_asn);
     }
 
-    //TODO: fix hold timer
+    /* RFC 6793: OPEN ASN field is 2 bytes. Use AS_TRANS (23456) if local ASN > 65535 */
+    open_asn = (*peer->local_asn > 65535) ? 23456 : (uint16_t)*peer->local_asn;
+
     log_print(LOG_DEBUG, "Sending OPEN to peer %s\n", peer->name);
-    /* Note: caps ownership transfers to the queued message, freed by free_msg() */
-    queue_and_send_open(peer, *peer->version, *peer->local_asn, 30, *peer->local_rid, caps);
+    queue_and_send_open(peer, *peer->version, open_asn, 30, *peer->local_rid, caps);
 
     start_timer(peer->local_timers, HoldTimer);
     peer->fsm_state = OPENSENT;
@@ -855,10 +859,30 @@ int fsm_state_opensent(struct bgp_peer *peer, struct bgp_msg *msg, fd_set *set)
         if (message->type == OPEN) {
             log_print(LOG_DEBUG, "Checking OPEN for correctness\n");
 
+            /* Check 4-byte ASN capability (RFC 6793) */
+            uint32_t peer_real_asn = message->open.asn;
+            uint32_t peer_cap_asn = 0;
+            int peer_has_4byte = 0;
+
+            if (message->open.capabilities) {
+                peer_has_4byte = bgp_capabilities_has_four_octet_asn(
+                    message->open.capabilities, &peer_cap_asn);
+            }
+
+            if (peer_has_4byte) {
+                /* Peer supports 4-byte ASN - use capability value as real ASN */
+                peer_real_asn = peer_cap_asn;
+                peer->four_octet_asn = 1;
+                log_print(LOG_INFO, "Peer %s supports 4-byte ASN (ASN %u)\n",
+                    peer->name, peer_real_asn);
+            } else {
+                peer->four_octet_asn = 0;
+            }
+
             //Check peer ASN matches configured ASN
-            if (message->open.asn != peer->peer_asn) {
-                log_print(LOG_WARN, "Peer %s ASN mismatch: expected %d, got %d\n",
-                    peer->name, peer->peer_asn, message->open.asn);
+            if (peer_real_asn != peer->peer_asn) {
+                log_print(LOG_WARN, "Peer %s ASN mismatch: expected %u, got %u\n",
+                    peer->name, peer->peer_asn, peer_real_asn);
                 queue_and_send_notification(peer, BGP_ERR_OPEN, BGP_ERR_OPEN_PEER_AS);
                 bgp_close_socket(peer);
                 peer->fsm_state = IDLE;

src/bgp.h

@@ -13,10 +13,10 @@ struct bgp_peer;
 struct bgp_instance;
 struct bgp_local;
 
-struct bgp_instance *create_bgp_instance(uint16_t,  uint32_t, uint8_t);
+struct bgp_instance *create_bgp_instance(uint32_t,  uint32_t, uint8_t);
 void free_bgp_instance(struct bgp_instance *);
 
-unsigned int create_bgp_peer(struct bgp_instance *, const char *, const uint16_t, const char *);
+unsigned int create_bgp_peer(struct bgp_instance *, const char *, const uint32_t, const char *);
 unsigned int bgp_peer_source(struct bgp_instance *, unsigned int, const char *);
 
 int set_bgp_output(struct bgp_instance *, unsigned int, enum bgp_output);

src/bgp_capability.c

@@ -238,3 +238,24 @@ const char *bgp_capability_name(uint8_t code) {
         default:                       return "Unknown";
     }
 }
+
+int bgp_capabilities_has_four_octet_asn(const struct bgp_capabilities *caps, uint32_t *asn) {
+    struct list_head *pos;
+    struct bgp_capability *cap;
+
+    if (!caps) {
+        return 0;
+    }
+
+    list_for_each(pos, &caps->caps) {
+        cap = list_entry(pos, struct bgp_capability, list);
+        if (cap->code == BGP_CAP_FOUR_OCTET_ASN && cap->length == 4 && cap->value) {
+            if (asn) {
+                *asn = uchar_be_to_uint32(cap->value);
+            }
+            return 1;
+        }
+    }
+
+    return 0;
+}

src/bgp_capability.h

@@ -126,3 +126,9 @@ struct bgp_capabilities *bgp_capabilities_parse(const unsigned char *opt_params,
  * Returns a static string describing the capability
  */
 const char *bgp_capability_name(uint8_t code);
+
+/*
+ * Check if 4-octet ASN capability is present and extract the ASN
+ * Returns 1 if present (and sets *asn to the 4-byte ASN), 0 if not present
+ */
+int bgp_capabilities_has_four_octet_asn(const struct bgp_capabilities *caps, uint32_t *asn);