bgpd: Start abstraction of `struct peer_connection`

BGP tracks connections based upon the peer.  But the problem
with this is that the doppelganger structure for it is being
created.  This has introduced a bunch of fragileness in that
the peer exists independently of the connections to it.

The whole point of the doppelganger structure was to allow
BGP to both accept and initiate tcp connections and then
when we get one to a `good` state we collapse into the
appropriate one.  The problem with this is that having
2 peer structures for this creates a situation where
we have to make sure we are configing the `right` one
and also make sure that we collapse the two independent
peer structures into 1 acting peer.  This makes no sense
let's abstract out the peer into having 2 connection
one for incoming connections and one for outgoing connections
then we can easily collapse down without having to do crazy
stuff.  In addition people adding new features don't need
to have to go touch a million places in the code.

This is the start of this abstraction.  In this commit
we'll just pull out the fd and input/output buffers
into a connection data structure.  Future commits
will abstract further.

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

1 files changed, 29 insertions, 28 deletions

diff --git a/bgpd/bgp_network.c b/bgpd/bgp_network.c
index 73fe00c7ab..f83b9e8064 100644
--- a/bgpd/bgp_network.c
+++ b/bgpd/bgp_network.c
@@ -429,7 +429,7 @@ static void bgp_accept(struct event *thread)
 		peer1 = peer_lookup_dynamic_neighbor(bgp, &su);
 		if (peer1) {
 			/* Dynamic neighbor has been created, let it proceed */
-			peer1->fd = bgp_sock;
+			peer1->connection.fd = bgp_sock;
 
 			/* Set the user configured MSS to TCP socket */
 			if (CHECK_FLAG(peer1->flags, PEER_FLAG_TCP_MSS))
@@ -521,10 +521,9 @@ static void bgp_accept(struct event *thread)
 	}
 
 	if (bgp_debug_neighbor_events(peer1))
-		zlog_debug(
-			"[Event] connection from %s fd %d, active peer status %d fd %d",
-			inet_sutop(&su, buf), bgp_sock, peer1->status,
-			peer1->fd);
+		zlog_debug("[Event] connection from %s fd %d, active peer status %d fd %d",
+			   inet_sutop(&su, buf), bgp_sock, peer1->status,
+			   peer1->connection.fd);
 
 	if (peer1->doppelganger) {
 		/* We have an existing connection. Kill the existing one and run
@@ -563,7 +562,7 @@ static void bgp_accept(struct event *thread)
 
 	peer->doppelganger = peer1;
 	peer1->doppelganger = peer;
-	peer->fd = bgp_sock;
+	peer->connection.fd = bgp_sock;
 	frr_with_privs(&bgpd_privs) {
 		vrf_bind(peer->bgp->vrf_id, bgp_sock, bgp_get_bound_name(peer));
 	}
@@ -684,13 +683,13 @@ static int bgp_update_source(struct peer *peer)
 		if (bgp_update_address(ifp, &peer->su, &addr))
 			return -1;
 
-		ret = sockunion_bind(peer->fd, &addr, 0, &addr);
+		ret = sockunion_bind(peer->connection.fd, &addr, 0, &addr);
 	}
 
 	/* Source is specified with IP address.  */
 	if (peer->update_source)
-		ret = sockunion_bind(peer->fd, peer->update_source, 0,
-				     peer->update_source);
+		ret = sockunion_bind(peer->connection.fd, peer->update_source,
+				     0, peer->update_source);
 
 	return ret;
 }
@@ -708,11 +707,12 @@ int bgp_connect(struct peer *peer)
 		return 0;
 	}
 	frr_with_privs(&bgpd_privs) {
-	/* Make socket for the peer. */
-		peer->fd = vrf_sockunion_socket(&peer->su, peer->bgp->vrf_id,
-						bgp_get_bound_name(peer));
+		/* Make socket for the peer. */
+		peer->connection.fd =
+			vrf_sockunion_socket(&peer->su, peer->bgp->vrf_id,
+					     bgp_get_bound_name(peer));
 	}
-	if (peer->fd < 0) {
+	if (peer->connection.fd < 0) {
 		peer->last_reset = PEER_DOWN_SOCKET_ERROR;
 		if (bgp_debug_neighbor_events(peer))
 			zlog_debug("%s: Failure to create socket for connection to %s, error received: %s(%d)",
@@ -721,18 +721,18 @@ int bgp_connect(struct peer *peer)
 		return -1;
 	}
 
-	set_nonblocking(peer->fd);
+	set_nonblocking(peer->connection.fd);
 
 	/* Set the user configured MSS to TCP socket */
 	if (CHECK_FLAG(peer->flags, PEER_FLAG_TCP_MSS))
-		sockopt_tcp_mss_set(peer->fd, peer->tcp_mss);
+		sockopt_tcp_mss_set(peer->connection.fd, peer->tcp_mss);
 
-	bgp_socket_set_buffer_size(peer->fd);
+	bgp_socket_set_buffer_size(peer->connection.fd);
 
 	/* Set TCP keepalive when TCP keepalive is enabled */
-	bgp_update_setsockopt_tcp_keepalive(peer->bgp, peer->fd);
+	bgp_update_setsockopt_tcp_keepalive(peer->bgp, peer->connection.fd);
 
-	if (bgp_set_socket_ttl(peer, peer->fd) < 0) {
+	if (bgp_set_socket_ttl(peer, peer->connection.fd) < 0) {
 		peer->last_reset = PEER_DOWN_SOCKET_ERROR;
 		if (bgp_debug_neighbor_events(peer))
 			zlog_debug("%s: Failure to set socket ttl for connection to %s, error received: %s(%d)",
@@ -742,15 +742,16 @@ int bgp_connect(struct peer *peer)
 		return -1;
 	}
 
-	sockopt_reuseaddr(peer->fd);
-	sockopt_reuseport(peer->fd);
+	sockopt_reuseaddr(peer->connection.fd);
+	sockopt_reuseport(peer->connection.fd);
 
 #ifdef IPTOS_PREC_INTERNETCONTROL
 	frr_with_privs(&bgpd_privs) {
 		if (sockunion_family(&peer->su) == AF_INET)
-			setsockopt_ipv4_tos(peer->fd, bm->tcp_dscp);
+			setsockopt_ipv4_tos(peer->connection.fd, bm->tcp_dscp);
 		else if (sockunion_family(&peer->su) == AF_INET6)
-			setsockopt_ipv6_tclass(peer->fd, bm->tcp_dscp);
+			setsockopt_ipv6_tclass(peer->connection.fd,
+					       bm->tcp_dscp);
 	}
 #endif
 
@@ -762,7 +763,7 @@ int bgp_connect(struct peer *peer)
 		if (!BGP_PEER_SU_UNSPEC(peer))
 			bgp_md5_set(peer);
 
-		bgp_md5_set_connect(peer->fd, &peer->su, prefixlen,
+		bgp_md5_set_connect(peer->connection.fd, &peer->su, prefixlen,
 				    peer->password);
 	}
 
@@ -779,11 +780,11 @@ int bgp_connect(struct peer *peer)
 
 	if (bgp_debug_neighbor_events(peer))
 		zlog_debug("%s [Event] Connect start to %s fd %d", peer->host,
-			   peer->host, peer->fd);
+			   peer->host, peer->connection.fd);
 
 	/* Connect to the remote peer. */
-	return sockunion_connect(peer->fd, &peer->su, htons(peer->port),
-				 ifindex);
+	return sockunion_connect(peer->connection.fd, &peer->su,
+				 htons(peer->port), ifindex);
 }
 
 /* After TCP connection is established.  Get local address and port. */
@@ -799,10 +800,10 @@ int bgp_getsockname(struct peer *peer)
 		peer->su_remote = NULL;
 	}
 
-	peer->su_local = sockunion_getsockname(peer->fd);
+	peer->su_local = sockunion_getsockname(peer->connection.fd);
 	if (!peer->su_local)
 		return -1;
-	peer->su_remote = sockunion_getpeername(peer->fd);
+	peer->su_remote = sockunion_getpeername(peer->connection.fd);
 	if (!peer->su_remote)
 		return -1;