tipc: split UDP nl address parsing

Split the UDP netlink parse function so that it only parses one
netlink attribute at the time. This makes the parse function more
generic and allow future UDP API functions to use it for parsing.
Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/udp_media.c

@@ -258,68 +258,47 @@ static int enable_mcast(struct udp_bearer *ub, struct udp_media_addr *remote)
 }
 
 /**
- * parse_options - build local/remote addresses from configuration
- * @attrs:	netlink config data
- * @ub:		UDP bearer instance
- * @local:	local bearer IP address/port
- * @remote:	peer or multicast IP/port
+ * tipc_parse_udp_addr - build udp media address from netlink data
+ * @nlattr:	netlink attribute containing sockaddr storage aligned address
+ * @addr:	tipc media address to fill with address, port and protocol type
+ * @scope_id:	IPv6 scope id pointer, not NULL indicates it's required
  */
-static int parse_options(struct nlattr *attrs[], struct udp_bearer *ub,
-			 struct udp_media_addr *local,
-			 struct udp_media_addr *remote)
+
+static int tipc_parse_udp_addr(struct nlattr *nla, struct udp_media_addr *addr,
+			       u32 *scope_id)
 {
-	struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
-	struct sockaddr_storage sa_local, sa_remote;
+	struct sockaddr_storage sa;
 
-	if (!attrs[TIPC_NLA_BEARER_UDP_OPTS])
-		goto err;
-	if (nla_parse_nested(opts, TIPC_NLA_UDP_MAX,
-			     attrs[TIPC_NLA_BEARER_UDP_OPTS],
-			     tipc_nl_udp_policy))
-		goto err;
-	if (opts[TIPC_NLA_UDP_LOCAL] && opts[TIPC_NLA_UDP_REMOTE]) {
-		nla_memcpy(&sa_local, opts[TIPC_NLA_UDP_LOCAL],
-			   sizeof(sa_local));
-		nla_memcpy(&sa_remote, opts[TIPC_NLA_UDP_REMOTE],
-			   sizeof(sa_remote));
-	} else {
-err:
-		pr_err("Invalid UDP bearer configuration");
-		return -EINVAL;
-	}
-	if ((sa_local.ss_family & sa_remote.ss_family) == AF_INET) {
-		struct sockaddr_in *ip4;
-
-		ip4 = (struct sockaddr_in *)&sa_local;
-		local->proto = htons(ETH_P_IP);
-		local->port = ip4->sin_port;
-		local->ipv4.s_addr = ip4->sin_addr.s_addr;
-
-		ip4 = (struct sockaddr_in *)&sa_remote;
-		remote->proto = htons(ETH_P_IP);
-		remote->port = ip4->sin_port;
-		remote->ipv4.s_addr = ip4->sin_addr.s_addr;
+	nla_memcpy(&sa, nla, sizeof(sa));
+	if (sa.ss_family == AF_INET) {
+		struct sockaddr_in *ip4 = (struct sockaddr_in *)&sa;
+
+		addr->proto = htons(ETH_P_IP);
+		addr->port = ip4->sin_port;
+		addr->ipv4.s_addr = ip4->sin_addr.s_addr;
 		return 0;
 
 #if IS_ENABLED(CONFIG_IPV6)
-	} else if ((sa_local.ss_family & sa_remote.ss_family) == AF_INET6) {
-		int atype;
-		struct sockaddr_in6 *ip6;
-
-		ip6 = (struct sockaddr_in6 *)&sa_local;
-		atype = ipv6_addr_type(&ip6->sin6_addr);
-		if (__ipv6_addr_needs_scope_id(atype) && !ip6->sin6_scope_id)
-			return -EINVAL;
-
-		local->proto = htons(ETH_P_IPV6);
-		local->port = ip6->sin6_port;
-		memcpy(&local->ipv6, &ip6->sin6_addr, sizeof(struct in6_addr));
-		ub->ifindex = ip6->sin6_scope_id;
-
-		ip6 = (struct sockaddr_in6 *)&sa_remote;
-		remote->proto = htons(ETH_P_IPV6);
-		remote->port = ip6->sin6_port;
-		memcpy(&remote->ipv6, &ip6->sin6_addr, sizeof(struct in6_addr));
+	} else if (sa.ss_family == AF_INET6) {
+		struct sockaddr_in6 *ip6 = (struct sockaddr_in6 *)&sa;
+
+		addr->proto = htons(ETH_P_IPV6);
+		addr->port = ip6->sin6_port;
+		memcpy(&addr->ipv6, &ip6->sin6_addr, sizeof(struct in6_addr));
+
+		/* Scope ID is only interesting for local addresses */
+		if (scope_id) {
+			int atype;
+
+			atype = ipv6_addr_type(&ip6->sin6_addr);
+			if (__ipv6_addr_needs_scope_id(atype) &&
+			    !ip6->sin6_scope_id) {
+				return -EINVAL;
+			}
+
+			*scope_id = ip6->sin6_scope_id ? : 0;
+		}
+
 		return 0;
 #endif
 	}
@@ -344,14 +323,33 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
 	struct udp_media_addr local = {0};
 	struct udp_port_cfg udp_conf = {0};
 	struct udp_tunnel_sock_cfg tuncfg = {NULL};
+	struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
 
 	ub = kzalloc(sizeof(*ub), GFP_ATOMIC);
 	if (!ub)
 		return -ENOMEM;
 
+	if (!attrs[TIPC_NLA_BEARER_UDP_OPTS])
+		goto err;
+
+	if (nla_parse_nested(opts, TIPC_NLA_UDP_MAX,
+			     attrs[TIPC_NLA_BEARER_UDP_OPTS],
+			     tipc_nl_udp_policy))
+		goto err;
+
+	if (!opts[TIPC_NLA_UDP_LOCAL] || !opts[TIPC_NLA_UDP_REMOTE]) {
+		pr_err("Invalid UDP bearer configuration");
+		return -EINVAL;
+	}
+
+	err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_LOCAL], &local,
+				  &ub->ifindex);
+	if (err)
+		goto err;
+
 	remote = (struct udp_media_addr *)&b->bcast_addr.value;
 	memset(remote, 0, sizeof(struct udp_media_addr));
-	err = parse_options(attrs, ub, &local, remote);
+	err = tipc_parse_udp_addr(opts[TIPC_NLA_UDP_REMOTE], remote, NULL);
 	if (err)
 		goto err;