wireaddr: Do hostname resolution in parse_wireaddr.

Fixes: #834

common/test/run-ip_port_parsing.c

@@ -72,23 +72,23 @@ int main(void)
 	assert(!separate_address_and_port(ctx, "[::1]:http", &ip, &port));
 
 	// localhost hostnames for backward compat
-	parse_wireaddr("localhost", &addr, 200);
+	parse_wireaddr("localhost", &addr, 200, NULL);
 	assert(addr.port == 200);
 
 	// string should win the port battle
-	parse_wireaddr("[::1]:9735", &addr, 500);
+	parse_wireaddr("[::1]:9735", &addr, 500, NULL);
 	assert(addr.port == 9735);
 	ip = fmt_wireaddr(ctx, &addr);
 	assert(streq(ip, "[::1]:9735"));
 
 	// should use argument if we have no port in string
-	parse_wireaddr("2001:db8:85a3::8a2e:370:7334", &addr, 9777);
+	parse_wireaddr("2001:db8:85a3::8a2e:370:7334", &addr, 9777, NULL);
 	assert(addr.port == 9777);
 
 	ip = fmt_wireaddr(ctx, &addr);
 	assert(streq(ip, "[2001:db8:85a3::8a2e:370:7334]:9777"));
 
-	assert(parse_wireaddr("[::ffff:127.0.0.1]:49150", &addr, 1));
+	assert(parse_wireaddr("[::ffff:127.0.0.1]:49150", &addr, 1, NULL));
 	assert(addr.port == 49150);
 	tal_free(ctx);
 	return 0;

common/wireaddr.c

@@ -4,8 +4,10 @@
 #include <common/type_to_string.h>
 #include <common/utils.h>
 #include <common/wireaddr.h>
+#include <netdb.h>
 #include <netinet/in.h>
 #include <sys/socket.h>
+#include <sys/types.h>
 #include <wire/wire.h>
 
 /* Returns false if we didn't parse it, and *cursor == NULL if malformed. */
@@ -111,10 +113,16 @@ static bool separate_address_and_port(tal_t *ctx, const char *arg,
 	return true;
 }
 
-bool parse_wireaddr(const char *arg, struct wireaddr *addr, u16 defport)
+bool parse_wireaddr(const char *arg, struct wireaddr *addr, u16 defport,
+		    const char **err_msg)
 {
 	struct in6_addr v6;
 	struct in_addr v4;
+	struct sockaddr_in6 *sa6;
+	struct sockaddr_in *sa4;
+	struct addrinfo *addrinfo;
+	struct addrinfo hints;
+	int gai_err;
 	u16 port;
 	char *ip;
 	bool res;
@@ -122,13 +130,12 @@ bool parse_wireaddr(const char *arg, struct wireaddr *addr, u16 defport)
 
 	res = false;
 	port = defport;
+	if (err_msg)
+		*err_msg = NULL;
 
-	if (!separate_address_and_port(tmpctx, arg, &ip, &port)) {
-		tal_free(tmpctx);
-		return false;
-	}
+	if (!separate_address_and_port(tmpctx, arg, &ip, &port))
+		goto finish;
 
-	/* FIXME: change arg to addr[:port] and use getaddrinfo? */
 	if (streq(ip, "localhost"))
 		ip = "127.0.0.1";
 	else if (streq(ip, "ip6-localhost"))
@@ -150,6 +157,44 @@ bool parse_wireaddr(const char *arg, struct wireaddr *addr, u16 defport)
 		res = true;
 	}
 
+	/* Resolve with getaddrinfo */
+	if (!res) {
+		memset(&hints, 0, sizeof(hints));
+		hints.ai_family = AF_UNSPEC;
+		hints.ai_socktype = SOCK_STREAM;
+		hints.ai_protocol = 0;
+		hints.ai_flags = AI_ADDRCONFIG;
+		gai_err = getaddrinfo(ip, tal_fmt(tmpctx, "%d", port),
+				      &hints, &addrinfo);
+		if (gai_err != 0) {
+			if (err_msg)
+				*err_msg = gai_strerror(gai_err);
+			goto finish;
+		}
+		/* Use only the first found address */
+		if (addrinfo->ai_family == AF_INET) {
+			addr->type = ADDR_TYPE_IPV4;
+			addr->addrlen = 4;
+			addr->port = port;
+			sa4 = (struct sockaddr_in *) addrinfo->ai_addr;
+			memcpy(&addr->addr, &sa4->sin_addr, addr->addrlen);
+			res = true;
+		} else if (addrinfo->ai_family == AF_INET6) {
+			addr->type = ADDR_TYPE_IPV6;
+			addr->addrlen = 16;
+			addr->port = port;
+			sa6 = (struct sockaddr_in6 *) addrinfo->ai_addr;
+			memcpy(&addr->addr, &sa6->sin6_addr, addr->addrlen);
+			res = true;
+		}
+
+		/* Clean up */
+		freeaddrinfo(addrinfo);
+	}
+
+finish:
+	if (!res && err_msg && !*err_msg)
+		*err_msg = "Error parsing hostname";
 	tal_free(tmpctx);
 	return res;
 }

common/wireaddr.h

@@ -41,7 +41,7 @@ struct wireaddr {
 void towire_wireaddr(u8 **pptr, const struct wireaddr *addr);
 bool fromwire_wireaddr(const u8 **cursor, size_t *max, struct wireaddr *addr);
 
-bool parse_wireaddr(const char *arg, struct wireaddr *addr, u16 port);
+bool parse_wireaddr(const char *arg, struct wireaddr *addr, u16 port, const char **err_msg);
 
 char *fmt_wireaddr(const tal_t *ctx, const struct wireaddr *a);
 

lightningd/connect_control.c

@@ -114,6 +114,7 @@ static void json_connect(struct command *cmd,
 	const char *name;
 	struct wireaddr addr;
 	u8 *msg;
+	const char *err_msg;
 
 	if (!json_get_params(cmd, buffer, params,
 			     "id", &idtok,
@@ -178,9 +179,9 @@ static void json_connect(struct command *cmd,
 		} else {
 			addr.port = DEFAULT_PORT;
 		}
-		if (!parse_wireaddr(name, &addr, addr.port) || !addr.port) {
-			command_fail(cmd, "Host %s:%u not valid",
-				     name, addr.port);
+		if (!parse_wireaddr(name, &addr, addr.port, &err_msg) || !addr.port) {
+			command_fail(cmd, "Host %s:%u not valid: %s",
+				     name, addr.port, err_msg ? err_msg : "port is 0");
 			return;
 		}
 

lightningd/options.c

@@ -117,11 +117,12 @@ static char *opt_set_s32(const char *arg, s32 *u)
 static char *opt_add_ipaddr(const char *arg, struct lightningd *ld)
 {
 	size_t n = tal_count(ld->wireaddrs);
+	char const *err_msg;
 
 	tal_resize(&ld->wireaddrs, n+1);
 
-	if (!parse_wireaddr(arg, &ld->wireaddrs[n], ld->portnum)) {
-		return tal_fmt(NULL, "Unable to parse IP address '%s'", arg);
+	if (!parse_wireaddr(arg, &ld->wireaddrs[n], ld->portnum, &err_msg)) {
+		return tal_fmt(NULL, "Unable to parse IP address '%s': %s", arg, err_msg);
 	}
 
 	return NULL;

wallet/wallet.c

@@ -436,7 +436,7 @@ static struct peer *wallet_peer_load(struct wallet *w, const u64 dbid)
 	addrstr = sqlite3_column_text(stmt, 2);
 	if (addrstr) {
 		addrp = &addr;
-		if (!parse_wireaddr((const char*)addrstr, addrp, DEFAULT_PORT)) {
+		if (!parse_wireaddr((const char*)addrstr, addrp, DEFAULT_PORT, NULL)) {
 			sqlite3_finalize(stmt);
 			return NULL;
 		}
@@ -466,7 +466,7 @@ bool wallet_peer_by_nodeid(struct wallet *w, const struct pubkey *nodeid,
 		addrstr = sqlite3_column_text(stmt, 2);
 
 		if (addrstr)
-			parse_wireaddr((const char*)addrstr, &peer->addr, DEFAULT_PORT);
+			parse_wireaddr((const char*)addrstr, &peer->addr, DEFAULT_PORT, NULL);
 	} else {
 		/* Make sure we mark this as a new peer */
 		peer->dbid = 0;