bgpd: Set TCP min MSS per listener

Set only if at least one peer is in passive mode.

Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>

diff --git a/bgpd/bgp_network.c b/bgpd/bgp_network.c
index 3bfdeb17710ac6ccdc9fa53b816e8a83776c710e..f322de76833fad845fdd7eb464a4b1eada8c8c2f 100644 (file)
--- a/bgpd/bgp_network.c
+++ b/bgpd/bgp_network.c
@@ -334,6 +334,53 @@ static int bgp_get_instance_for_inc_conn(int sock, struct bgp **bgp_inst)
 #endif
 }
 
+int bgp_tcp_mss_set(struct peer *peer)
+{
+       struct listnode *node;
+       int ret = 0;
+       struct bgp_listener *listener;
+       uint32_t min_mss = 0;
+       struct peer *p;
+
+       for (ALL_LIST_ELEMENTS_RO(peer->bgp->peer, node, p)) {
+               if (!CHECK_FLAG(p->flags, PEER_FLAG_TCP_MSS))
+                       continue;
+
+               if (!p->tcp_mss)
+                       continue;
+
+               if (!min_mss)
+                       min_mss = p->tcp_mss;
+
+               min_mss = MIN(min_mss, p->tcp_mss);
+       }
+
+       frr_with_privs(&bgpd_privs) {
+               for (ALL_LIST_ELEMENTS_RO(bm->listen_sockets, node, listener)) {
+                       if (listener->su.sa.sa_family !=
+                           peer->connection->su.sa.sa_family)
+                               continue;
+
+                       if (!listener->bgp) {
+                               if (peer->bgp->vrf_id != VRF_DEFAULT)
+                                       continue;
+                       } else if (listener->bgp != peer->bgp)
+                               continue;
+
+                       /* Set TCP MSS per listener only if there is at least
+                        * one peer that is in passive mode. Otherwise, TCP MSS
+                        * is set per socket via bgp_connect().
+                        */
+                       if (CHECK_FLAG(peer->flags, PEER_FLAG_PASSIVE))
+                               sockopt_tcp_mss_set(listener->fd, min_mss);
+
+                       break;
+               }
+       }
+
+       return ret;
+}
+
 static void bgp_socket_set_buffer_size(const int fd)
 {
        if (getsockopt_so_sendbuf(fd) < (int)bm->socket_buffer)

diff --git a/bgpd/bgp_network.h b/bgpd/bgp_network.h
index f26d64f1f80582b3d3d4d8e8a8fe7c5deebf8762..7a0b3cc67d7ea7f506623c8ce573926dfea6ad36 100644 (file)
--- a/bgpd/bgp_network.h
+++ b/bgpd/bgp_network.h
@@ -30,6 +30,7 @@ extern int bgp_md5_unset_prefix(struct bgp *bgp, struct prefix *p);
 extern int bgp_md5_set(struct peer_connection *connection);
 extern int bgp_md5_unset(struct peer_connection *connection);
 extern int bgp_set_socket_ttl(struct peer_connection *connection);
+extern int bgp_tcp_mss_set(struct peer *peer);
 extern int bgp_update_address(struct interface *ifp, const union sockunion *dst,
                              union sockunion *addr);
 

diff --git a/bgpd/bgpd.c b/bgpd/bgpd.c
index 895f36f992e0808bd5329333c750c7a4ae31d3b1..585863954cc09653d11340478b949469c293a34a 100644 (file)
--- a/bgpd/bgpd.c
+++ b/bgpd/bgpd.c
@@ -5779,6 +5779,7 @@ void peer_tcp_mss_set(struct peer *peer, uint32_t tcp_mss)
 {
        peer->tcp_mss = tcp_mss;
        SET_FLAG(peer->flags, PEER_FLAG_TCP_MSS);
+       bgp_tcp_mss_set(peer);
 }
 
 /* Reset the TCP-MSS value in the peer structure,
@@ -5789,6 +5790,7 @@ void peer_tcp_mss_unset(struct peer *peer)
 {
        UNSET_FLAG(peer->flags, PEER_FLAG_TCP_MSS);
        peer->tcp_mss = 0;
+       bgp_tcp_mss_set(peer);
 }
 
 /*