bfdd: forbid setting interface for multihop sessions

Signed-off-by: Igor Ryzhov <iryzhov@nfware.com>

3 files changed, 55 insertions, 31 deletions

diff --git a/bfdd/bfdd_cli.c b/bfdd/bfdd_cli.c
index 6ec724d80..26ff4a758 100644
--- a/bfdd/bfdd_cli.c
+++ b/bfdd/bfdd_cli.c
@@ -125,7 +125,13 @@ DEFPY_YANG_NOSH(
 
 	if (multihop) {
 		if (!local_address_str) {
-			vty_out(vty, "%% local-address is required when using multihop\n");
+			vty_out(vty,
+				"%% local-address is required when using multihop\n");
+			return CMD_WARNING_CONFIG_FAILED;
+		}
+		if (ifname) {
+			vty_out(vty,
+				"%% interface is prohibited when using multihop\n");
 			return CMD_WARNING_CONFIG_FAILED;
 		}
 		snprintf(source_str, sizeof(source_str), "[source-addr='%s']",
@@ -140,7 +146,7 @@ DEFPY_YANG_NOSH(
 	if (ifname)
 		slen += snprintf(xpath + slen, sizeof(xpath) - slen,
 				 "[interface='%s']", ifname);
-	else
+	else if (!multihop)
 		slen += snprintf(xpath + slen, sizeof(xpath) - slen,
 				 "[interface='*']");
 	if (vrf)
@@ -185,10 +191,20 @@ DEFPY_YANG(
 	char xpath[XPATH_MAXLEN];
 	char source_str[INET6_ADDRSTRLEN + 32];
 
-	if (multihop)
+	if (multihop) {
+		if (!local_address_str) {
+			vty_out(vty,
+				"%% local-address is required when using multihop\n");
+			return CMD_WARNING_CONFIG_FAILED;
+		}
+		if (ifname) {
+			vty_out(vty,
+				"%% interface is prohibited when using multihop\n");
+			return CMD_WARNING_CONFIG_FAILED;
+		}
 		snprintf(source_str, sizeof(source_str), "[source-addr='%s']",
 			 local_address_str);
-	else
+	} else
 		source_str[0] = 0;
 
 	slen = snprintf(xpath, sizeof(xpath),
@@ -198,7 +214,7 @@ DEFPY_YANG(
 	if (ifname)
 		slen += snprintf(xpath + slen, sizeof(xpath) - slen,
 				 "[interface='%s']", ifname);
-	else
+	else if (!multihop)
 		slen += snprintf(xpath + slen, sizeof(xpath) - slen,
 				 "[interface='*']");
 	if (vrf)
@@ -218,7 +234,6 @@ static void _bfd_cli_show_peer(struct vty *vty, struct lyd_node *dnode,
 			       bool mhop)
 {
 	const char *vrf = yang_dnode_get_string(dnode, "./vrf");
-	const char *ifname = yang_dnode_get_string(dnode, "./interface");
 
 	vty_out(vty, " peer %s",
 		yang_dnode_get_string(dnode, "./dest-addr"));
@@ -233,8 +248,12 @@ static void _bfd_cli_show_peer(struct vty *vty, struct lyd_node *dnode,
 	if (strcmp(vrf, VRF_DEFAULT_NAME))
 		vty_out(vty, " vrf %s", vrf);
 
-	if (strcmp(ifname, "*"))
-		vty_out(vty, " interface %s", ifname);
+	if (!mhop) {
+		const char *ifname =
+			yang_dnode_get_string(dnode, "./interface");
+		if (strcmp(ifname, "*"))
+			vty_out(vty, " interface %s", ifname);
+	}
 
 	vty_out(vty, "\n");
 }
diff --git a/bfdd/bfdd_nb_config.c b/bfdd/bfdd_nb_config.c
index b221b6d53..859e9475d 100644
--- a/bfdd/bfdd_nb_config.c
+++ b/bfdd/bfdd_nb_config.c
@@ -45,11 +45,13 @@ static void bfd_session_get_key(bool mhop, const struct lyd_node *dnode,
 	if (yang_dnode_exists(dnode, "./source-addr"))
 		strtosa(yang_dnode_get_string(dnode, "./source-addr"), &lsa);
 
-	ifname = yang_dnode_get_string(dnode, "./interface");
 	vrfname = yang_dnode_get_string(dnode, "./vrf");
 
-	if (strcmp(ifname, "*") == 0)
-		ifname = NULL;
+	if (!mhop) {
+		ifname = yang_dnode_get_string(dnode, "./interface");
+		if (strcmp(ifname, "*") == 0)
+			ifname = NULL;
+	}
 
 	/* Generate the corresponding key. */
 	gen_bfd_key(bk, &psa, &lsa, mhop, ifname, vrfname);
@@ -80,7 +82,6 @@ static int bfd_session_create(struct nb_cb_create_args *args, bool mhop)
 	const struct lyd_node *sess_dnode;
 	struct session_iter iter;
 	struct bfd_session *bs;
-	const char *source;
 	const char *dest;
 	const char *ifname;
 	const char *vrfname;
@@ -89,13 +90,27 @@ static int bfd_session_create(struct nb_cb_create_args *args, bool mhop)
 
 	switch (args->event) {
 	case NB_EV_VALIDATE:
+		yang_dnode_get_prefix(&p, args->dnode, "./dest-addr");
+
+		if (mhop) {
+			/*
+			 * Do not allow IPv6 link-local address for multihop.
+			 */
+			if (p.family == AF_INET6
+			    && IN6_IS_ADDR_LINKLOCAL(&p.u.prefix6)) {
+				snprintf(
+					args->errmsg, args->errmsg_len,
+					"Cannot use link-local address for multihop sessions");
+				return NB_ERR_VALIDATION;
+			}
+			return NB_OK;
+		}
+
 		/*
 		 * When `dest-addr` is IPv6 and link-local we must
 		 * require interface name, otherwise we can't figure
 		 * which interface to use to send the packets.
 		 */
-		yang_dnode_get_prefix(&p, args->dnode, "./dest-addr");
-
 		ifname = yang_dnode_get_string(args->dnode, "./interface");
 
 		if (p.family == AF_INET6 && IN6_IS_ADDR_LINKLOCAL(&p.u.prefix6)
@@ -114,17 +129,9 @@ static int bfd_session_create(struct nb_cb_create_args *args, bool mhop)
 		dest = yang_dnode_get_string(args->dnode, "./dest-addr");
 		vrfname = yang_dnode_get_string(args->dnode, "./vrf");
 
-		if (mhop) {
-			source = yang_dnode_get_string(args->dnode, "./source-addr");
-
-			yang_dnode_iterate(session_iter_cb, &iter, sess_dnode,
-					   "./multi-hop[source-addr='%s'][dest-addr='%s'][vrf='%s']",
-					   source, dest, vrfname);
-		} else {
-			yang_dnode_iterate(session_iter_cb, &iter, sess_dnode,
-					   "./single-hop[dest-addr='%s'][vrf='%s']",
-					   dest, vrfname);
-		}
+		yang_dnode_iterate(session_iter_cb, &iter, sess_dnode,
+				   "./single-hop[dest-addr='%s'][vrf='%s']",
+				   dest, vrfname);
 
 		if (iter.wildcard && iter.count > 1) {
 			snprintf(
diff --git a/bfdd/bfdd_nb_state.c b/bfdd/bfdd_nb_state.c
index 043f850af..de0dcebfe 100644
--- a/bfdd/bfdd_nb_state.c
+++ b/bfdd/bfdd_nb_state.c
@@ -351,9 +351,8 @@ int bfdd_bfd_sessions_multi_hop_get_keys(struct nb_cb_get_keys_args *args)
 	args->keys->num = 4;
 	strlcpy(args->keys->key[0], srcbuf, sizeof(args->keys->key[0]));
 	strlcpy(args->keys->key[1], dstbuf, sizeof(args->keys->key[1]));
-	strlcpy(args->keys->key[2], bs->key.ifname, sizeof(args->keys->key[2]));
-	strlcpy(args->keys->key[3], bs->key.vrfname,
-		sizeof(args->keys->key[3]));
+	strlcpy(args->keys->key[2], bs->key.vrfname,
+		sizeof(args->keys->key[2]));
 
 	return NB_OK;
 }
@@ -363,14 +362,13 @@ bfdd_bfd_sessions_multi_hop_lookup_entry(struct nb_cb_lookup_entry_args *args)
 {
 	const char *source_addr = args->keys->key[0];
 	const char *dest_addr = args->keys->key[1];
-	const char *ifname = args->keys->key[2];
-	const char *vrf = args->keys->key[3];
+	const char *vrf = args->keys->key[2];
 	struct sockaddr_any psa, lsa;
 	struct bfd_key bk;
 
 	strtosa(dest_addr, &psa);
 	strtosa(source_addr, &lsa);
-	gen_bfd_key(&bk, &psa, &lsa, true, ifname, vrf);
+	gen_bfd_key(&bk, &psa, &lsa, true, NULL, vrf);
 
 	return bfd_key_lookup(bk);
 }