bgpd: Only update peer connection information when needed

Currently bgp is repeatedly grabbing peer connection information.
This is a bit overkill.  There are two situations:

a) Opening a connection to the peer
   In this case, we know the remote port/address a priori and can get
   the local information by just asking the OS.
b) Peer opening a connection to us.
   In this case, we know the local port/address a priori and can get
   the remote information by just asking the OS.

Modify the code to just grab this data at the appropriate time.

Signed-off-by: Donald Sharp <sharpd@nvidia.com>

3 files changed, 22 insertions, 16 deletions

diff --git a/bgpd/bgp_fsm.c b/bgpd/bgp_fsm.c
index 8097f5317..0e3ed9f0d 100644
--- a/bgpd/bgp_fsm.c
+++ b/bgpd/bgp_fsm.c
@@ -1819,7 +1819,6 @@ static void bgp_connect_in_progress_update_connection(struct peer_connection *co
 {
 	struct peer *peer = connection->peer;
 
-	bgp_updatesockname(connection);
 	if (!connection->su_remote && !BGP_CONNECTION_SU_UNSPEC(connection)) {
 		/* if connect initiated, then dest port and dest addresses are well known */
 		connection->su_remote = sockunion_dup(&connection->su);
diff --git a/bgpd/bgp_network.c b/bgpd/bgp_network.c
index e4984ea46..af5d815d3 100644
--- a/bgpd/bgp_network.c
+++ b/bgpd/bgp_network.c
@@ -484,6 +484,9 @@ static void bgp_accept(struct event *thread)
 			/* Dynamic neighbor has been created, let it proceed */
 			connection1->fd = bgp_sock;
 
+			connection1->su_local = sockunion_getsockname(connection1->fd);
+			connection1->su_remote = sockunion_dup(&su);
+
 			if (bgp_set_socket_ttl(connection1) < 0) {
 				peer1->last_reset = PEER_DOWN_SOCKET_ERROR;
 				zlog_err("%s: Unable to set min/max TTL on peer %s (dynamic), error received: %s(%d)",
@@ -623,7 +626,10 @@ static void bgp_accept(struct event *thread)
 
 	peer->doppelganger = peer1;
 	peer1->doppelganger = peer;
+
 	connection->fd = bgp_sock;
+	connection->su_local = sockunion_getsockname(connection->fd);
+	connection->su_remote = sockunion_dup(&su);
 
 	if (bgp_set_socket_ttl(connection) < 0)
 		if (bgp_debug_neighbor_events(peer))
@@ -857,24 +863,28 @@ enum connect_result bgp_connect(struct peer_connection *connection)
 			   peer->host, connection->fd);
 
 	/* Connect to the remote peer. */
-	return sockunion_connect(connection->fd, &connection->su,
-				 htons(peer->port), ifindex);
-}
+	enum connect_result res;
 
-void bgp_updatesockname(struct peer_connection *connection)
-{
-	if (connection->su_local) {
-		sockunion_free(connection->su_local);
-		connection->su_local = NULL;
-	}
+	res = sockunion_connect(connection->fd, &connection->su, htons(peer->port), ifindex);
 
-	if (connection->su_remote) {
+	if (connection->su_remote)
 		sockunion_free(connection->su_remote);
-		connection->su_remote = NULL;
+
+	connection->su_remote = sockunion_dup(&connection->su);
+	switch (connection->su.sa.sa_family) {
+	case AF_INET:
+		connection->su_remote->sin.sin_port = htons(peer->port);
+		break;
+	case AF_INET6:
+		connection->su_remote->sin6.sin6_port = htons(peer->port);
+		break;
 	}
 
+	if (connection->su_local)
+		sockunion_free(connection->su_local);
 	connection->su_local = sockunion_getsockname(connection->fd);
-	connection->su_remote = sockunion_getpeername(connection->fd);
+
+	return res;
 }
 
 /* After TCP connection is established.  Get local address and port. */
@@ -882,8 +892,6 @@ int bgp_getsockname(struct peer_connection *connection)
 {
 	struct peer *peer = connection->peer;
 
-	bgp_updatesockname(connection);
-
 	if (!bgp_zebra_nexthop_set(connection->su_local, connection->su_remote, &peer->nexthop,
 				   peer)) {
 		flog_err(EC_BGP_NH_UPD,
diff --git a/bgpd/bgp_network.h b/bgpd/bgp_network.h
index bd8c285f3..a2f4851f1 100644
--- a/bgpd/bgp_network.h
+++ b/bgpd/bgp_network.h
@@ -23,7 +23,6 @@ extern void bgp_close_vrf_socket(struct bgp *bgp);
 extern void bgp_close(void);
 extern enum connect_result bgp_connect(struct peer_connection *connection);
 extern int bgp_getsockname(struct peer_connection *connection);
-extern void bgp_updatesockname(struct peer_connection *connection);
 
 extern int bgp_md5_set_prefix(struct bgp *bgp, struct prefix *p,
 			      const char *password);