pimd: MSDP peer MD5 authentication

doc/user/pim.rst

@@ -386,6 +386,17 @@ Commands available for MSDP:
       The filtering will only take effect starting from the command
       application.
 
+.. clicmd:: msdp peer A.B.C.D password WORD
+
+   Use MD5 authentication to connect with the remote peer.
+
+   .. note::
+
+      The authentication will only take effect when starting a new
+      connection.
+
+      To apply it immediately call `clear ip msdp peer A.B.C.D`.
+
 
 .. _show-pim-information:
 
@@ -715,6 +726,13 @@ Clear commands reset various variables.
    removes the next hop tracking for the bsr and resets the upstreams
    for the dynamically learnt RPs.
 
+.. clicmd:: clear ip msdp peer A.B.C.D
+
+   Reset MSDP peer connection.
+
+   Use this command to set/unset MD5 authentication.
+
+
 PIM EVPN configuration
 ======================
 To use PIM in the underlay for overlay BUM forwarding associate a multicast

lib/sockopt.h

@@ -60,6 +60,16 @@ extern int setsockopt_ipv6_tclass(int, int);
   (((af) == AF_INET) : SOPT_SIZE_CMSG_IFINDEX_IPV4() \
                     ? SOPT_SIZE_CMSG_PKTINFO_IPV6())
 
+/*
+ * If not defined then define the value for `TCP_MD5SIG_MAXKEYLEN`. This seems
+ * to be unavailable for NetBSD 8, FreeBSD 11 and FreeBSD 12.
+ *
+ * The value below was copied from `linux/tcp.h` from the Linux kernel headers.
+ */
+#ifndef TCP_MD5SIG_MAXKEYLEN
+#define TCP_MD5SIG_MAXKEYLEN 80
+#endif
+
 extern int setsockopt_ipv4_multicast_if(int sock, struct in_addr if_addr,
 					ifindex_t ifindex);
 extern int setsockopt_ipv4_multicast(int sock, int optname,

pimd/pim_cmd.c

@@ -2823,6 +2823,39 @@ DEFPY (clear_ip_mroute_count,
 	return clear_ip_mroute_count_command(vty, name);
 }
 
+DEFPY(clear_ip_msdp_peer, clear_ip_msdp_peer_cmd,
+      "clear ip msdp peer A.B.C.D$peer [vrf WORD$vrfname]",
+      CLEAR_STR
+      IP_STR
+      MSDP_STR
+      "Restart MSDP peer\n"
+      "MSDP peer address\n"
+      VRF_CMD_HELP_STR)
+{
+	const struct pim_instance *pim;
+	const struct listnode *node;
+	const struct vrf *vrf;
+	struct pim_msdp_peer *mp;
+
+	if (vrfname) {
+		vrf = vrf_lookup_by_name(vrfname);
+		if (vrf == NULL)
+			return CMD_WARNING;
+	} else
+		vrf = vrf_lookup_by_id(VRF_DEFAULT);
+
+	pim = vrf->info;
+	for (ALL_LIST_ELEMENTS_RO(pim->msdp.peer_list, node, mp)) {
+		if (mp->peer.s_addr != peer.s_addr)
+			continue;
+
+		pim_msdp_peer_restart(mp);
+		break;
+	}
+
+	return CMD_SUCCESS;
+}
+
 DEFPY (show_ip_mroute_count,
        show_ip_mroute_count_cmd,
        "show ip mroute [vrf NAME] count [json$json]",
@@ -6285,6 +6318,57 @@ DEFPY_ATTR(ip_pim_msdp_peer,
 	return ret;
 }
 
+DEFPY(msdp_peer_md5, msdp_peer_md5_cmd,
+      "msdp peer A.B.C.D$peer password WORD$psk",
+      CFG_MSDP_STR
+      "Configure MSDP peer\n"
+      "MSDP Peer address\n"
+      "Use MD5 authentication\n"
+      "MD5 pre shared key\n")
+{
+	const struct lyd_node *peer_node;
+	char xpath[XPATH_MAXLEN + 24];
+
+	snprintf(xpath, sizeof(xpath), "%s/msdp-peer[peer-ip='%s']",
+		 VTY_CURR_XPATH, peer_str);
+	peer_node = yang_dnode_get(vty->candidate_config->dnode, xpath);
+	if (peer_node == NULL) {
+		vty_out(vty, "%% MSDP peer %s not yet configured\n", peer_str);
+		return CMD_SUCCESS;
+	}
+
+	nb_cli_enqueue_change(vty, "./authentication-type", NB_OP_MODIFY, "MD5");
+	nb_cli_enqueue_change(vty, "./authentication-key", NB_OP_MODIFY, psk);
+
+	return nb_cli_apply_changes(vty, "%s", xpath);
+}
+
+DEFPY(no_msdp_peer_md5, no_msdp_peer_md5_cmd,
+      "no msdp peer A.B.C.D$peer password [WORD]",
+      NO_STR
+      CFG_MSDP_STR
+      "Configure MSDP peer\n"
+      "MSDP Peer address\n"
+      "Use MD5 authentication\n"
+      "MD5 pre shared key\n")
+{
+	const struct lyd_node *peer_node;
+	char xpath[XPATH_MAXLEN + 24];
+
+	snprintf(xpath, sizeof(xpath), "%s/msdp-peer[peer-ip='%s']",
+		 VTY_CURR_XPATH, peer_str);
+	peer_node = yang_dnode_get(vty->candidate_config->dnode, xpath);
+	if (peer_node == NULL) {
+		vty_out(vty, "%% MSDP peer %s not yet configured\n", peer_str);
+		return CMD_SUCCESS;
+	}
+
+	nb_cli_enqueue_change(vty, "./authentication-type", NB_OP_MODIFY,
+			      "None");
+
+	return nb_cli_apply_changes(vty, "%s", xpath);
+}
+
 DEFPY(pim_msdp_timers, pim_msdp_timers_cmd,
       "msdp timers (1-65535)$keepalive (1-65535)$holdtime [(1-65535)$connretry]",
       CFG_MSDP_STR
@@ -8320,6 +8404,8 @@ void pim_cmd_init(void)
 
 	install_element(PIM_NODE, &pim_msdp_peer_cmd);
 	install_element(PIM_NODE, &no_pim_msdp_peer_cmd);
+	install_element(PIM_NODE, &msdp_peer_md5_cmd);
+	install_element(PIM_NODE, &no_msdp_peer_md5_cmd);
 	install_element(PIM_NODE, &pim_msdp_timers_cmd);
 	install_element(PIM_NODE, &no_pim_msdp_timers_cmd);
 	install_element(PIM_NODE, &msdp_peer_sa_filter_cmd);
@@ -8462,6 +8548,7 @@ void pim_cmd_init(void)
 	install_element(ENABLE_NODE, &pim_test_sg_keepalive_cmd);
 
 	install_element(ENABLE_NODE, &clear_ip_mroute_count_cmd);
+	install_element(ENABLE_NODE, &clear_ip_msdp_peer_cmd);
 	install_element(ENABLE_NODE, &clear_ip_interfaces_cmd);
 	install_element(ENABLE_NODE, &clear_ip_igmp_interfaces_cmd);
 	install_element(ENABLE_NODE, &clear_ip_mroute_cmd);

pimd/pim_memory.c

@@ -26,6 +26,7 @@ DEFINE_MTYPE(PIMD, PIM_RP, "PIM RP info");
 DEFINE_MTYPE(PIMD, PIM_FILTER_NAME, "PIM RP filter info");
 DEFINE_MTYPE(PIMD, PIM_MSDP_PEER, "PIM MSDP peer");
 DEFINE_MTYPE(PIMD, PIM_MSDP_MG_NAME, "PIM MSDP mesh-group name");
+DEFINE_MTYPE(PIMD, PIM_MSDP_AUTH_KEY, "PIM MSDP authentication key");
 DEFINE_MTYPE(PIMD, PIM_MSDP_SA, "PIM MSDP source-active cache");
 DEFINE_MTYPE(PIMD, PIM_MSDP_MG, "PIM MSDP mesh group");
 DEFINE_MTYPE(PIMD, PIM_MSDP_MG_MBR, "PIM MSDP mesh group mbr");

pimd/pim_memory.h

@@ -28,6 +28,7 @@ DECLARE_MTYPE(PIM_MSDP_MG_NAME);
 DECLARE_MTYPE(PIM_MSDP_SA);
 DECLARE_MTYPE(PIM_MSDP_MG);
 DECLARE_MTYPE(PIM_MSDP_MG_MBR);
+DECLARE_MTYPE(PIM_MSDP_AUTH_KEY);
 DECLARE_MTYPE(PIM_SEC_ADDR);
 DECLARE_MTYPE(PIM_JP_AGG_GROUP);
 DECLARE_MTYPE(PIM_JP_AGG_SOURCE);

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);

pimd/pim_msdp.h

@@ -89,6 +89,11 @@ enum pim_msdp_peer_flags {
 	PIM_MSDP_PEERF_IN_GROUP = (1 << 2),
 };
 
+enum msdp_auth_type {
+	MSDP_AUTH_NONE = 0,
+	MSDP_AUTH_MD5 = 1,
+};
+
 struct pim_msdp_peer {
 	struct pim_instance *pim;
 
@@ -98,6 +103,13 @@ struct pim_msdp_peer {
 	char *mesh_group_name;
 	char key_str[INET_ADDRSTRLEN];
 
+	/* Authentication data. */
+	enum msdp_auth_type auth_type;
+	char *auth_key;
+
+	int auth_listen_sock;
+	struct event *auth_listen_ev;
+
 	/* state */
 	enum pim_msdp_peer_state state;
 	enum pim_msdp_peer_flags flags;
@@ -309,6 +321,15 @@ void pim_msdp_peer_del(struct pim_msdp_peer **mp);
 void pim_msdp_peer_change_source(struct pim_msdp_peer *mp,
 				 const struct in_addr *addr);
 
+/**
+ * Restart peer's connection.
+ *
+ * This is used internally in MSDP and should be used by northbound
+ * when wanting to immediately apply connections settings such as
+ * authentication.
+ */
+void pim_msdp_peer_restart(struct pim_msdp_peer *mp);
+
 #else /* PIM_IPV == 6 */
 static inline void pim_msdp_init(struct pim_instance *pim,
 				 struct event_loop *master)