pimd: add support for MSDP authentication

Implement MSDP MD5 authentication connection support.

Implementation details:
- Move the MSDP socket creation code to a generic function so it can be
  parametrized to be used with/without authentication.
- The MSDP peer connection will not change when the configuration is
  set, instead it will only be applied next connection or when
  `clear ip msdp peer A.B.C.D` is called.

Signed-off-by: Rafael Zalamena <rzalamena@opensourcerouting.org>

1 files changed, 32 insertions, 5 deletions

diff --git a/pimd/pim_msdp.c b/pimd/pim_msdp.c
index 0bb2d93a3a..215cc3c502 100644
--- a/pimd/pim_msdp.c
+++ b/pimd/pim_msdp.c
@@ -773,7 +773,10 @@ static void pim_msdp_peer_listen(struct pim_msdp_peer *mp)
 	* first listening peer is configured; but don't bother tearing it down
 	* when
 	* all the peers go down */
-	pim_msdp_sock_listen(mp->pim);
+	if (mp->auth_type == MSDP_AUTH_NONE)
+		pim_msdp_sock_listen(mp->pim);
+	else
+		pim_msdp_sock_auth_listen(mp);
 }
 
 /* 11.2.A4 and 11.2.A5: transition active or passive peer to
@@ -1045,6 +1048,7 @@ struct pim_msdp_peer *pim_msdp_peer_add(struct pim_instance *pim,
 
 	mp->state = PIM_MSDP_INACTIVE;
 	mp->fd = -1;
+	mp->auth_listen_sock = -1;
 	strlcpy(mp->last_reset, "-", sizeof(mp->last_reset));
 	/* higher IP address is listener */
 	if (ntohl(mp->local.s_addr) > ntohl(mp->peer.s_addr)) {
@@ -1100,6 +1104,12 @@ static void pim_msdp_peer_free(struct pim_msdp_peer *mp)
 		stream_fifo_free(mp->obuf);
 	}
 
+	/* Free authentication data. */
+	event_cancel(&mp->auth_listen_ev);
+	XFREE(MTYPE_PIM_MSDP_AUTH_KEY, mp->auth_key);
+	if (mp->auth_listen_sock != -1)
+		close(mp->auth_listen_sock);
+
 	XFREE(MTYPE_PIM_MSDP_MG_NAME, mp->mesh_group_name);
 
 	mp->pim = NULL;
@@ -1128,19 +1138,32 @@ void pim_msdp_peer_del(struct pim_msdp_peer **mp)
 	*mp = NULL;
 }
 
-void pim_msdp_peer_change_source(struct pim_msdp_peer *mp,
-				 const struct in_addr *addr)
+void pim_msdp_peer_restart(struct pim_msdp_peer *mp)
 {
-	pim_msdp_peer_stop_tcp_conn(mp, true);
+	/* Stop auth listening socket if any. */
+	event_cancel(&mp->auth_listen_ev);
+	if (mp->auth_listen_sock != -1) {
+		close(mp->auth_listen_sock);
+		mp->auth_listen_sock = -1;
+	}
 
-	mp->local = *addr;
+	/* Stop previously running connection. */
+	pim_msdp_peer_stop_tcp_conn(mp, true);
 
+	/* Start connection again. */
 	if (PIM_MSDP_PEER_IS_LISTENER(mp))
 		pim_msdp_peer_listen(mp);
 	else
 		pim_msdp_peer_connect(mp);
 }
 
+void pim_msdp_peer_change_source(struct pim_msdp_peer *mp,
+				 const struct in_addr *addr)
+{
+	mp->local = *addr;
+	pim_msdp_peer_restart(mp);
+}
+
 /* peer hash and peer list helpers */
 static unsigned int pim_msdp_peer_hash_key_make(const void *p)
 {
@@ -1318,6 +1341,10 @@ bool pim_msdp_peer_config_write(struct vty *vty, struct pim_instance *pim)
 		vty_out(vty, " msdp peer %pI4 source %pI4\n", &mp->peer,
 			&mp->local);
 
+		if (mp->auth_type == MSDP_AUTH_MD5)
+			vty_out(vty, " msdp peer %pI4 password %s\n", &mp->peer,
+				mp->auth_key);
+
 		if (mp->acl_in)
 			vty_out(vty, " msdp peer %pI4 sa-filter %s in\n",
 				&mp->peer, mp->acl_in);