Tor: don't do seed queries if we're supposed to always use proxy.

Risks leakage.  We could do lookup via the proxy, but that's a TODO.

There's only one occurance of getaddrinfo (and no gethostbyname), so
we add a flag to the callers.

Note: the use of --always-use-proxy suppresses *all* DNS lookups, even
those from connect commands and the command line.

FIXME: An implicit setting of use_proxy_always is done in gossipd if it
determines that we are announcing nothing but Tor addresses, but that
does *not* suppress 'connect'.

This is fixed in a later patch.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

common/test/run-ip_port_parsing.c

@@ -85,35 +85,35 @@ int main(void)
 	assert(!separate_address_and_port(tmpctx, "[::1]:http", &ip, &port));
 
 	// localhost hostnames for backward compat
-	assert(parse_wireaddr("localhost", &addr, 200, NULL));
+	assert(parse_wireaddr("localhost", &addr, 200, false, NULL));
 	assert(addr.port == 200);
 
 	// string should win the port battle
-	assert(parse_wireaddr("[::1]:9735", &addr, 500, NULL));
+	assert(parse_wireaddr("[::1]:9735", &addr, 500, false, NULL));
 	assert(addr.port == 9735);
 	ip = fmt_wireaddr(tmpctx, &addr);
 	assert(streq(ip, "[::1]:9735"));
 
 	// should use argument if we have no port in string
-	assert(parse_wireaddr("2001:db8:85a3::8a2e:370:7334", &addr, 9777, NULL));
+	assert(parse_wireaddr("2001:db8:85a3::8a2e:370:7334", &addr, 9777, false, NULL));
 	assert(addr.port == 9777);
 
 	ip = fmt_wireaddr(tmpctx, &addr);
 	assert(streq(ip, "[2001:db8:85a3::8a2e:370:7334]:9777"));
 
-	assert(parse_wireaddr("[::ffff:127.0.0.1]:49150", &addr, 1, NULL));
+	assert(parse_wireaddr("[::ffff:127.0.0.1]:49150", &addr, 1, false, NULL));
 	assert(addr.port == 49150);
 
-  assert(parse_wireaddr("4ruvswpqec5i2gogopxl4vm5bruzknbvbylov2awbo4rxiq4cimdldad.onion:49150", &addr, 1, NULL));
+  assert(parse_wireaddr("4ruvswpqec5i2gogopxl4vm5bruzknbvbylov2awbo4rxiq4cimdldad.onion:49150", &addr, 1, false, NULL));
 	assert(addr.port == 49150);
 
-	assert(parse_wireaddr("4ruvswpqec5i2gogopxl4vm5bruzknbvbylov2awbo4rxiq4cimdldad.onion", &addr, 1, NULL));
+	assert(parse_wireaddr("4ruvswpqec5i2gogopxl4vm5bruzknbvbylov2awbo4rxiq4cimdldad.onion", &addr, 1, false, NULL));
 	assert(addr.port == 1);
 
-	assert(parse_wireaddr("odpzvneidqdf5hdq.onion:49150", &addr, 1, NULL));
+	assert(parse_wireaddr("odpzvneidqdf5hdq.onion:49150", &addr, 1, false, NULL));
 	assert(addr.port == 49150);
 
-	assert(parse_wireaddr("odpzvneidqdf5hdq.onion", &addr, 1, NULL));
+	assert(parse_wireaddr("odpzvneidqdf5hdq.onion", &addr, 1, false, NULL));
 	assert(addr.port == 1);
 	tal_free(tmpctx);
 	return 0;

common/wireaddr.c

@@ -262,7 +262,7 @@ static bool separate_address_and_port(const tal_t *ctx, const char *arg,
 }
 
 bool wireaddr_from_hostname(struct wireaddr *addr, const char *hostname,
-			    const u16 port, const char **err_msg)
+			    const u16 port, bool dns_ok, const char **err_msg)
 {
 	struct sockaddr_in6 *sa6;
 	struct sockaddr_in *sa4;
@@ -296,6 +296,8 @@ bool wireaddr_from_hostname(struct wireaddr *addr, const char *hostname,
 	hints.ai_socktype = SOCK_STREAM;
 	hints.ai_protocol = 0;
 	hints.ai_flags = AI_ADDRCONFIG;
+	if (!dns_ok)
+		hints.ai_flags = AI_NUMERICHOST;
 	gai_err = getaddrinfo(hostname, tal_fmt(tmpctx, "%d", port),
 			      &hints, &addrinfo);
 	if (gai_err != 0) {
@@ -320,7 +322,7 @@ bool wireaddr_from_hostname(struct wireaddr *addr, const char *hostname,
 }
 
 bool parse_wireaddr(const char *arg, struct wireaddr *addr, u16 defport,
-		    const char **err_msg)
+		    bool dns_ok, const char **err_msg)
 {
 	struct in6_addr v6;
 	struct in_addr v4;
@@ -353,7 +355,7 @@ bool parse_wireaddr(const char *arg, struct wireaddr *addr, u16 defport,
 
 	/* Resolve with getaddrinfo */
 	if (!res)
-		res = wireaddr_from_hostname(addr, ip, port, err_msg);
+		res = wireaddr_from_hostname(addr, ip, port, dns_ok, err_msg);
 
 finish:
 	if (!res && err_msg && !*err_msg)
@@ -362,7 +364,8 @@ finish:
 }
 
 bool parse_wireaddr_internal(const char *arg, struct wireaddr_internal *addr,
-			     u16 port, bool wildcard_ok, const char **err_msg)
+			     u16 port, bool wildcard_ok, bool dns_ok,
+			     const char **err_msg)
 {
 	u16 wildport;
 	char *ip;
@@ -392,7 +395,7 @@ bool parse_wireaddr_internal(const char *arg, struct wireaddr_internal *addr,
 	}
 
 	addr->itype = ADDR_INTERNAL_WIREADDR;
-	return parse_wireaddr(arg, &addr->u.wireaddr, port, err_msg);
+	return parse_wireaddr(arg, &addr->u.wireaddr, port, dns_ok, err_msg);
 }
 
 void wireaddr_from_sockname(struct wireaddr_internal *addr,

common/wireaddr.h

@@ -67,13 +67,14 @@ enum addr_listen_announce fromwire_addr_listen_announce(const u8 **cursor,
 							size_t *max);
 void towire_addr_listen_announce(u8 **pptr, enum addr_listen_announce ala);
 
-bool parse_wireaddr(const char *arg, struct wireaddr *addr, u16 port, const char **err_msg);
+bool parse_wireaddr(const char *arg, struct wireaddr *addr, u16 port,
+		    bool dns_ok, const char **err_msg);
 
 char *fmt_wireaddr(const tal_t *ctx, const struct wireaddr *a);
 char *fmt_wireaddr_without_port(const tal_t *ctx, const struct wireaddr *a);
 
 bool wireaddr_from_hostname(struct wireaddr *addr, const char *hostname,
-			    const u16 port, const char **err_msg);
+			    const u16 port, bool dns_ok, const char **err_msg);
 
 void wireaddr_from_ipv4(struct wireaddr *addr,
 			const struct in_addr *ip4,
@@ -104,7 +105,9 @@ struct wireaddr_internal {
 		char sockname[sizeof(((struct sockaddr_un *)0)->sun_path)];
 	} u;
 };
-bool parse_wireaddr_internal(const char *arg, struct wireaddr_internal *addr, u16 port, bool wildcard_ok, const char **err_msg);
+bool parse_wireaddr_internal(const char *arg, struct wireaddr_internal *addr,
+			     u16 port, bool wildcard_ok, bool dns_ok,
+			     const char **err_msg);
 
 void towire_wireaddr_internal(u8 **pptr,
 				 const struct wireaddr_internal *addr);

gossipd/gossip.c

@@ -1930,7 +1930,8 @@ static struct io_plan *conn_tor_init(struct io_conn *conn,
 }
 
 static struct addrhint *
-seed_resolve_addr(const tal_t *ctx, const struct pubkey *id, const u16 port)
+seed_resolve_addr(const tal_t *ctx, const struct pubkey *id, const u16 port,
+		  bool dns_ok)
 {
 	struct addrhint *a;
 	char bech32[100], *addr;
@@ -1946,7 +1947,8 @@ seed_resolve_addr(const tal_t *ctx, const struct pubkey *id, const u16 port)
 
 	a = tal(ctx, struct addrhint);
 	a->addr.itype = ADDR_INTERNAL_WIREADDR;
-	if (!wireaddr_from_hostname(&a->addr.u.wireaddr, addr, port, NULL)) {
+	if (!wireaddr_from_hostname(&a->addr.u.wireaddr, addr, port, dns_ok,
+				    NULL)) {
 		status_trace("Could not resolve %s", addr);
 		return tal_free(a);
 	} else {
@@ -2033,7 +2035,8 @@ static void try_reach_peer(struct daemon *daemon, const struct pubkey *id,
 					id);
 
 	if (!a)
-		a = seed_resolve_addr(tmpctx, id, 9735);
+		a = seed_resolve_addr(tmpctx, id, 9735,
+				      !daemon->use_proxy_always);
 
 	if (!a) {
 		status_debug("No address known for %s, giving up",

lightningd/connect_control.c

@@ -152,6 +152,7 @@ static void json_connect(struct command *cmd,
 			port = DEFAULT_PORT;
 		}
 		if (!parse_wireaddr_internal(name, &addr, port, false,
+					     !cmd->ld->use_proxy_always,
 					     &err_msg)) {
 			command_fail(cmd, "Host %s:%u not valid: %s",
 				     name, port, err_msg ? err_msg : "port is 0");

lightningd/options.c

@@ -159,7 +159,7 @@ static char *opt_add_addr_withtype(const char *arg,
 	ld->proposed_listen_announce[n] = ala;
 
 	if (!parse_wireaddr_internal(arg, &ld->proposed_wireaddr[n], ld->portnum,
-				     true, &err_msg)) {
+				     true, !ld->use_proxy_always, &err_msg)) {
 		return tal_fmt(NULL, "Unable to parse address '%s': %s", arg, err_msg);
 	}
 
@@ -302,7 +302,8 @@ static char *opt_add_proxy_addr(const char *arg, struct lightningd *ld)
 	/* We use a tal_arr here, so we can marshal it to gossipd */
 	ld->proxyaddr = tal_arr(ld, struct wireaddr, 1);
 
-	if (!parse_wireaddr(arg, ld->proxyaddr, 9050, NULL)) {
+	if (!parse_wireaddr(arg, ld->proxyaddr, 9050, !ld->use_proxy_always,
+			    NULL)) {
 		return tal_fmt(NULL, "Unable to parse Tor proxy address '%s'",
 			       arg);
 	}
@@ -313,7 +314,8 @@ static char *opt_add_tor_service_addr(const char *arg, struct lightningd *ld)
 {
 	tal_free(ld->tor_serviceaddr);
 	ld->tor_serviceaddr = tal(ld, struct wireaddr);
-	if (!parse_wireaddr(arg, ld->tor_serviceaddr, 9051, NULL)) {
+	if (!parse_wireaddr(arg, ld->tor_serviceaddr, 9051,
+			    !ld->use_proxy_always, NULL)) {
 		return tal_fmt(NULL, "Unable to parse Tor service address '%s'",
 			       arg);
 	}
@@ -432,8 +434,11 @@ static void config_register_opts(struct lightningd *ld)
 			 "Set a Tor hidden service password");
 	opt_register_arg("--tor-auto-listen", opt_set_bool_arg, opt_show_bool,
 			&ld->config.tor_enable_auto_hidden_service , "Generate and use a temp auto hidden-service and show the onion address");
-	opt_register_arg("--always-use-proxy", opt_set_bool_arg, opt_show_bool,
-			&ld->use_proxy_always, "Use the proxy always");
+
+	/* Early, as it suppresses DNS lookups from cmdline too. */
+	opt_register_early_arg("--always-use-proxy",
+			       opt_set_bool_arg, opt_show_bool,
+			       &ld->use_proxy_always, "Use the proxy always");
 }
 
 #if DEVELOPER

lightningd/tor.c

@@ -94,7 +94,7 @@ static void make_onion(struct lightningd *ld, struct rbuf *rbuf)
 		tal_resize(&ld->proposed_listen_announce, n + 1);
 		parse_wireaddr_internal(tal_fmt(tmpctx, "%s.onion", line),
 					&ld->proposed_wireaddr[n],
-					ld->portnum, false, NULL);
+					ld->portnum, false, false, NULL);
 		ld->proposed_listen_announce[n] = ADDR_ANNOUNCE;
 		discard_remaining_response(ld, rbuf);
 		return;

wallet/wallet.c

@@ -510,7 +510,7 @@ 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_internal((const char*)addrstr, addrp, DEFAULT_PORT, false, NULL)) {
+		if (!parse_wireaddr_internal((const char*)addrstr, addrp, DEFAULT_PORT, false, false, NULL)) {
 			db_stmt_done(stmt);
 			return NULL;
 		}