wireaddr: new type, ADDR_INTERNAL_FORPROXY, use it if we can't/wont resolve.

Tor wasn't actually working for me to connect to anything, but it worked
for 'ssh -D' testing.

Note that the resulting 'netaddr' is a bit weird, but I guess it's honest.

    $ ./cli/lightning-cli connect 021f2cbffc4045ca2d70678ecf8ed75e488290874c9da38074f6d378248337062b
    {
      "id": "021f2cbffc4045ca2d70678ecf8ed75e488290874c9da38074f6d378248337062b"
    }
    $ ./cli/lightning-cli listpeers
    {
      "peers": [
        {
          "state": "GOSSIPING", 
          "id": "021f2cbffc4045ca2d70678ecf8ed75e488290874c9da38074f6d378248337062b", 
          "netaddr": [
            "ln1qg0je0lugpzu5ttsv78vlrkhteyg9yy8fjw68qr57mfhsfyrxurzkq522ah.lseed.bitcoinstats.com:9735"
          ], 
          "connected": true, 
          "owner": "lightning_gossipd"
        }
      ]
    }

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

common/wireaddr.c

@@ -83,6 +83,11 @@ void towire_wireaddr_internal(u8 **pptr, const struct wireaddr_internal *addr)
 	case ADDR_INTERNAL_WIREADDR:
 		towire_wireaddr(pptr, &addr->u.wireaddr);
 		return;
+	case ADDR_INTERNAL_FORPROXY:
+		towire_u8_array(pptr, (const u8 *)addr->u.unresolved.name,
+				sizeof(addr->u.unresolved.name));
+		towire_u16(pptr, addr->u.unresolved.port);
+		return;
 	}
 	abort();
 }
@@ -106,6 +111,15 @@ bool fromwire_wireaddr_internal(const u8 **cursor, size_t *max,
 		return fromwire_wireaddr(cursor, max, &addr->u.torservice);
 	case ADDR_INTERNAL_WIREADDR:
 		return fromwire_wireaddr(cursor, max, &addr->u.wireaddr);
+	case ADDR_INTERNAL_FORPROXY:
+		fromwire_u8_array(cursor, max, (u8 *)addr->u.unresolved.name,
+				  sizeof(addr->u.unresolved.name));
+		/* Must be NUL terminated */
+		if (!memchr(addr->u.unresolved.name, 0,
+			    sizeof(addr->u.unresolved.name)))
+			fromwire_fail(cursor, max);
+		addr->u.unresolved.port = fromwire_u16(cursor, max);
+		return *cursor != NULL;
 	}
 	fromwire_fail(cursor, max);
 	return false;
@@ -179,6 +193,9 @@ char *fmt_wireaddr_internal(const tal_t *ctx,
 		return tal_fmt(ctx, ":%u", a->u.port);
 	case ADDR_INTERNAL_WIREADDR:
 		return fmt_wireaddr(ctx, &a->u.wireaddr);
+	case ADDR_INTERNAL_FORPROXY:
+		return tal_fmt(ctx, "%s:%u",
+			       a->u.unresolved.name, a->u.unresolved.port);
 	case ADDR_INTERNAL_AUTOTOR:
 		return tal_fmt(ctx, "autotor:%s",
 			       fmt_wireaddr(tmpctx, &a->u.torservice));
@@ -383,11 +400,12 @@ finish:
 
 bool parse_wireaddr_internal(const char *arg, struct wireaddr_internal *addr,
 			     u16 port, bool wildcard_ok, bool dns_ok,
+			     bool unresolved_ok,
 			     const char **err_msg)
 {
-	u16 wildport;
+	u16 splitport;
 	char *ip;
-	bool needed_dns;
+	bool needed_dns = false;
 
 	/* Addresses starting with '/' are local socket paths */
 	if (arg[0] == '/') {
@@ -405,12 +423,12 @@ bool parse_wireaddr_internal(const char *arg, struct wireaddr_internal *addr,
 
 	/* An empty string means IPv4 and IPv6 (which under Linux by default
 	 * means just IPv6, and IPv4 gets autobound). */
-	wildport = port;
+	splitport = port;
 	if (wildcard_ok
-	    && separate_address_and_port(tmpctx, arg, &ip, &wildport)
+	    && separate_address_and_port(tmpctx, arg, &ip, &splitport)
 	    && streq(ip, "")) {
 		addr->itype = ADDR_INTERNAL_ALLPROTO;
-		addr->u.port = wildport;
+		addr->u.port = splitport;
 		return true;
 	}
 
@@ -425,8 +443,33 @@ bool parse_wireaddr_internal(const char *arg, struct wireaddr_internal *addr,
 	}
 
 	addr->itype = ADDR_INTERNAL_WIREADDR;
-	return parse_wireaddr(arg, &addr->u.wireaddr, port,
-			      dns_ok ? NULL : &needed_dns, err_msg);
+	if (parse_wireaddr(arg, &addr->u.wireaddr, port,
+			   dns_ok ? NULL : &needed_dns, err_msg))
+		return true;
+
+	if (!needed_dns || !unresolved_ok)
+		return false;
+
+	/* We can't do DNS, so keep unresolved. */
+	if (!wireaddr_from_unresolved(addr, ip, splitport)) {
+		if (err_msg)
+			*err_msg = "Name too long";
+		return false;
+	}
+	return true;
+}
+
+bool wireaddr_from_unresolved(struct wireaddr_internal *addr,
+			      const char *name, u16 port)
+{
+	addr->itype = ADDR_INTERNAL_FORPROXY;
+	if (strlen(name) >= sizeof(addr->u.unresolved.name))
+		return false;
+
+	memset(addr->u.unresolved.name, 0, sizeof(addr->u.unresolved.name));
+	strcpy(addr->u.unresolved.name, name);
+	addr->u.unresolved.port = port;
+	return true;
 }
 
 void wireaddr_from_sockname(struct wireaddr_internal *addr,
@@ -466,6 +509,7 @@ struct addrinfo *wireaddr_internal_to_addrinfo(const tal_t *ctx,
 		return ai;
 	case ADDR_INTERNAL_ALLPROTO:
 	case ADDR_INTERNAL_AUTOTOR:
+	case ADDR_INTERNAL_FORPROXY:
 		break;
 	case ADDR_INTERNAL_WIREADDR:
 		return wireaddr_to_addrinfo(ctx, &wireaddr->u.wireaddr);
@@ -511,6 +555,8 @@ bool all_tor_addresses(const struct wireaddr_internal *wireaddr)
 		switch (wireaddr[i].itype) {
 		case ADDR_INTERNAL_SOCKNAME:
 			return false;
+		case ADDR_INTERNAL_FORPROXY:
+			abort();
 		case ADDR_INTERNAL_ALLPROTO:
 			return false;
 		case ADDR_INTERNAL_AUTOTOR:

common/wireaddr.h

@@ -104,6 +104,7 @@ enum wireaddr_internal_type {
 	ADDR_INTERNAL_SOCKNAME,
 	ADDR_INTERNAL_ALLPROTO,
 	ADDR_INTERNAL_AUTOTOR,
+	ADDR_INTERNAL_FORPROXY,
 	ADDR_INTERNAL_WIREADDR,
 };
 
@@ -117,13 +118,18 @@ struct wireaddr_internal {
 		u16 port;
 		/* ADDR_INTERNAL_AUTOTOR */
 		struct wireaddr torservice;
+		/* ADDR_INTERNAL_FORPROXY */
+		struct unresolved {
+			char name[256];
+			u16 port;
+		} unresolved;
 		/* ADDR_INTERNAL_SOCKNAME */
 		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, bool dns_ok,
-			     const char **err_msg);
+			     bool unresolved_ok, const char **err_msg);
 
 void towire_wireaddr_internal(u8 **pptr,
 				 const struct wireaddr_internal *addr);
@@ -132,6 +138,9 @@ bool fromwire_wireaddr_internal(const u8 **cursor, size_t *max,
 char *fmt_wireaddr_internal(const tal_t *ctx,
 			       const struct wireaddr_internal *a);
 
+bool wireaddr_from_unresolved(struct wireaddr_internal *addr,
+			      const char *name, u16 port);
+
 void wireaddr_from_sockname(struct wireaddr_internal *addr,
 			    const char *sockname);
 bool wireaddr_to_sockname(const struct wireaddr_internal *addr,

gossipd/gossip.c

@@ -1711,6 +1711,8 @@ static struct wireaddr_internal *setup_listeners(const tal_t *ctx,
 			if (public_address(daemon, &wa.u.wireaddr))
 				add_announcable(daemon, &wa.u.wireaddr);
 			continue;
+		case ADDR_INTERNAL_FORPROXY:
+			break;
 		}
 		/* Shouldn't happen. */
 		status_failed(STATUS_FAIL_INTERNAL_ERROR,
@@ -1911,6 +1913,10 @@ static struct io_plan *conn_init(struct io_conn *conn, struct reaching *reach)
 		status_failed(STATUS_FAIL_INTERNAL_ERROR,
 			      "Can't reach to autotor address");
 		break;
+	case ADDR_INTERNAL_FORPROXY:
+		status_failed(STATUS_FAIL_INTERNAL_ERROR,
+			      "Can't reach to forproxy address");
+		break;
 	case ADDR_INTERNAL_WIREADDR:
 		/* If it was a Tor address, we wouldn't be here. */
 		ai = wireaddr_to_addrinfo(tmpctx, &reach->addr.u.wireaddr);
@@ -1929,6 +1935,10 @@ static struct io_plan *conn_proxy_init(struct io_conn *conn,
 	u16 port;
 
 	switch (reach->addr.itype) {
+	case ADDR_INTERNAL_FORPROXY:
+		host = reach->addr.u.unresolved.name;
+		port = reach->addr.u.unresolved.port;
+		break;
 	case ADDR_INTERNAL_WIREADDR:
 		host = fmt_wireaddr_without_port(tmpctx,
 						 &reach->addr.u.wireaddr);
@@ -2024,7 +2034,7 @@ static void try_reach_peer(struct daemon *daemon, const struct pubkey *id,
 	int fd, af;
 	struct reaching *reach;
 	u8 *msg;
-	bool use_proxy;
+	bool use_proxy = daemon->use_proxy_always;
 	struct peer *peer = find_peer(daemon, id);
 
 	if (peer) {
@@ -2063,8 +2073,16 @@ static void try_reach_peer(struct daemon *daemon, const struct pubkey *id,
 					daemon->rstate,
 					id);
 
-	if (!a && !daemon->use_proxy_always)
+	if (!a) {
+		/* Don't resolve via DNS seed if we're supposed to use proxy. */
+		if (use_proxy) {
+			a = tal(tmpctx, struct wireaddr_internal);
+			wireaddr_from_unresolved(a, seedname(tmpctx, id),
+						 DEFAULT_PORT);
+		} else {
 			a = seed_resolve_addr(tmpctx, id);
+		}
+	}
 
 	if (!a) {
 		status_debug("No address known for %s, giving up",
@@ -2080,7 +2098,6 @@ static void try_reach_peer(struct daemon *daemon, const struct pubkey *id,
 
 	/* Might not even be able to create eg. IPv6 sockets */
 	af = -1;
-	use_proxy = daemon->use_proxy_always;
 
 	switch (a->itype) {
 	case ADDR_INTERNAL_SOCKNAME:
@@ -2094,6 +2111,9 @@ static void try_reach_peer(struct daemon *daemon, const struct pubkey *id,
 	case ADDR_INTERNAL_AUTOTOR:
 		status_failed(STATUS_FAIL_INTERNAL_ERROR,
 			      "Can't reach AUTOTOR");
+	case ADDR_INTERNAL_FORPROXY:
+		use_proxy = true;
+		break;
 	case ADDR_INTERNAL_WIREADDR:
 		switch (a->u.wireaddr.type) {
 		case ADDR_TYPE_TOR_V2:

lightningd/connect_control.c

@@ -154,6 +154,7 @@ static void json_connect(struct command *cmd,
 		if (!parse_wireaddr_internal(name, &addr, port, false,
 					     !cmd->ld->use_proxy_always
 					     && !cmd->ld->pure_tor_setup,
+					     true,
 					     &err_msg)) {
 			command_fail(cmd, "Host %s:%u not valid: %s",
 				     name, port, err_msg ? err_msg : "port is 0");

lightningd/json.c

@@ -174,6 +174,13 @@ void json_add_address_internal(struct json_result *response,
 		json_add_address(response, "service", &addr->u.torservice);
 		json_object_end(response);
 		return;
+	case ADDR_INTERNAL_FORPROXY:
+		json_object_start(response, fieldname);
+		json_add_string(response, "type", "unresolved");
+		json_add_string(response, "name", addr->u.unresolved.name);
+		json_add_num(response, "port", addr->u.unresolved.port);
+		json_object_end(response);
+		return;
 	case ADDR_INTERNAL_WIREADDR:
 		json_add_address(response, fieldname, &addr->u.wireaddr);
 		return;

lightningd/options.c

@@ -160,7 +160,7 @@ 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,
-				     wildcard_ok, !ld->use_proxy_always,
+				     wildcard_ok, !ld->use_proxy_always, false,
 				     &err_msg)) {
 		return tal_fmt(NULL, "Unable to parse address '%s': %s", arg, err_msg);
 	}

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, false, NULL)) {
+		if (!parse_wireaddr_internal((const char*)addrstr, addrp, DEFAULT_PORT, false, false, true, NULL)) {
 			db_stmt_done(stmt);
 			return NULL;
 		}