opts: announce-addr-discovered on/off/auto switch

This adds the option to explicitly enable ip-discovery, which maybe
helpful for example when a user wants TOR announced along with
discovered IPs to improve connectivity and have TOR just as a fallback.

Changelog-Added: Adds config switch 'announce-addr-discovered': on/off/auto

doc/lightning-listconfigs.7.md

@@ -88,7 +88,8 @@ On success, an object is returned, containing:
 - **autolisten** (boolean, optional): `autolisten` field from config or cmdline, or default
 - **proxy** (string, optional): `proxy` field from config or cmdline, or default
 - **disable-dns** (boolean, optional): `true` if `disable-dns` was set in config or cmdline
-- **disable-ip-discovery** (boolean, optional): `true` if `disable-ip-discovery` was set in config or cmdline
+- **disable-ip-discovery** (boolean, optional): `true` if `disable-ip-discovery` was set in config or cmdline (DEPRECATED)
+- **ip-discovery** (string, optional): `true` if `ip-discovery` was set in config or cmdline
 - **encrypted-hsm** (boolean, optional): `true` if `encrypted-hsm` was set in config or cmdline
 - **rpc-file-mode** (string, optional): `rpc-file-mode` field from config or cmdline, or default
 - **log-level** (string, optional): `log-level` field from config or cmdline, or default

doc/schemas/listconfigs.schema.json

@@ -247,6 +247,11 @@
       "type": "boolean",
       "description": "`true` if `disable-ip-discovery` was set in config or cmdline"
     },
+    "announce-addr-discovered": {
+      "type": "string",
+      "description": "`true`/`false`/`auto` depending on how `announce-addr-discovered` was set in config or cmdline",
+      "added": "v23.02"
+    },
     "encrypted-hsm": {
       "type": "boolean",
       "description": "`true` if `encrypted-hsm` was set in config or cmdline"

gossipd/gossip_generation.c

@@ -3,6 +3,7 @@
 #include "config.h"
 #include <ccan/asort/asort.h>
 #include <ccan/cast/cast.h>
+#include <ccan/ccan/opt/opt.h>
 #include <ccan/mem/mem.h>
 #include <common/daemon_conn.h>
 #include <common/features.h>
@@ -44,8 +45,10 @@ static u8 *create_node_announcement(const tal_t *ctx, struct daemon *daemon,
 		tal_arr_expand(&was, daemon->announceable[i]);
 
 	/* Add discovered IPs v4/v6 verified by peer `remote_addr` feature. */
-	/* Only do that if we don't have addresses announced. */
-	if (count_announceable == 0) {
+	/* Only do that if we don't have any addresses announced or
+	 * `config.ip_discovery` is explicitly enabled. */
+	if ((daemon->ip_discovery == OPT_AUTOBOOL_AUTO && count_announceable == 0) ||
+	     daemon->ip_discovery == OPT_AUTOBOOL_TRUE) {
 		if (daemon->discovered_ip_v4 != NULL &&
 		    !wireaddr_arr_contains(was, daemon->discovered_ip_v4))
 			tal_arr_expand(&was, *daemon->discovered_ip_v4);

gossipd/gossipd.c

@@ -346,6 +346,7 @@ static void handle_local_private_channel(struct daemon *daemon, const u8 *msg)
 static void handle_discovered_ip(struct daemon *daemon, const u8 *msg)
 {
 	struct wireaddr discovered_ip;
+	size_t count_announceable;
 
 	if (!fromwire_gossipd_discovered_ip(msg, &discovered_ip))
 		master_badmsg(WIRE_GOSSIPD_DISCOVERED_IP, msg);
@@ -380,8 +381,11 @@ static void handle_discovered_ip(struct daemon *daemon, const u8 *msg)
 	return;
 
 update_node_annoucement:
-	status_debug("Update our node_announcement for discovered address: %s",
-		     fmt_wireaddr(tmpctx, &discovered_ip));
+	count_announceable = tal_count(daemon->announceable);
+	if ((daemon->ip_discovery == OPT_AUTOBOOL_AUTO && count_announceable == 0) ||
+	     daemon->ip_discovery == OPT_AUTOBOOL_TRUE)
+		status_debug("Update our node_announcement for discovered address: %s",
+			     fmt_wireaddr(tmpctx, &discovered_ip));
 	maybe_send_own_node_announce(daemon, false);
 }
 
@@ -727,7 +731,8 @@ static void gossip_init(struct daemon *daemon, const u8 *msg)
 				     &daemon->announceable,
 				     &dev_gossip_time,
 				     &dev_fast_gossip,
-				     &dev_fast_gossip_prune)) {
+				     &dev_fast_gossip_prune,
+				     &daemon->ip_discovery)) {
 		master_badmsg(WIRE_GOSSIPD_INIT, msg);
 	}
 
@@ -1096,6 +1101,7 @@ int main(int argc, char *argv[])
 	daemon->rates = NULL;
 	daemon->discovered_ip_v4 = NULL;
 	daemon->discovered_ip_v6 = NULL;
+	daemon->ip_discovery = OPT_AUTOBOOL_AUTO;
 	list_head_init(&daemon->deferred_updates);
 
 	/* Tell the ecdh() function how to talk to hsmd */

gossipd/gossipd.h

@@ -1,6 +1,7 @@
 #ifndef LIGHTNING_GOSSIPD_GOSSIPD_H
 #define LIGHTNING_GOSSIPD_GOSSIPD_H
 #include "config.h"
+#include <ccan/ccan/opt/opt.h>
 #include <ccan/timer/timer.h>
 #include <common/node_id.h>
 #include <lightningd/options.h>
@@ -52,6 +53,7 @@ struct daemon {
 	/* verified remote_addr as reported by recent peers */
 	struct wireaddr *discovered_ip_v4;
 	struct wireaddr *discovered_ip_v6;
+	enum opt_autobool ip_discovery;
 
 	/* Timer until we can send an updated node_announcement */
 	struct oneshot *node_announce_timer;

gossipd/gossipd_wire.csv

@@ -16,6 +16,7 @@ msgdata,gossipd_init,announceable,wireaddr,num_announceable
 msgdata,gossipd_init,dev_gossip_time,?u32,
 msgdata,gossipd_init,dev_fast_gossip,bool,
 msgdata,gossipd_init,dev_fast_gossip_prune,bool,
+msgdata,gossipd_init,ip_discovery,u32,
 
 msgtype,gossipd_init_reply,3100
 

lightningd/gossip_control.c

@@ -262,7 +262,8 @@ void gossip_init(struct lightningd *ld, int connectd_fd)
 	    ld->announceable,
 	    IFDEV(ld->dev_gossip_time ? &ld->dev_gossip_time: NULL, NULL),
 	    IFDEV(ld->dev_fast_gossip, false),
-	    IFDEV(ld->dev_fast_gossip_prune, false));
+	    IFDEV(ld->dev_fast_gossip_prune, false),
+	    ld->config.ip_discovery);
 
 	subd_req(ld->gossip, ld->gossip, take(msg), -1, 0,
 		 gossipd_init_done, NULL);

lightningd/lightningd.h

@@ -1,6 +1,7 @@
 #ifndef LIGHTNING_LIGHTNINGD_LIGHTNINGD_H
 #define LIGHTNING_LIGHTNINGD_LIGHTNINGD_H
 #include "config.h"
+#include <ccan/ccan/opt/opt.h>
 #include <lightningd/htlc_end.h>
 #include <lightningd/htlc_set.h>
 #include <lightningd/options.h>
@@ -58,6 +59,8 @@ struct config {
 	/* Are we allowed to use DNS lookup for peers. */
 	bool use_dns;
 
+	/* Excplicitly turns 'on' or 'off' IP discovery feature. */
+	enum opt_autobool ip_discovery;
 	/* Turn off IP address announcement discovered via peer `remote_addr` */
 	bool disable_ip_discovery;
 

lightningd/options.c

@@ -843,6 +843,8 @@ static const struct config testnet_config = {
 
 	.use_dns = true,
 
+	/* Excplicitly turns 'on' or 'off' IP discovery feature. */
+	.ip_discovery = OPT_AUTOBOOL_AUTO,
 	/* Turn off IP address announcement discovered via peer `remote_addr` */
 	.disable_ip_discovery = false,
 
@@ -909,6 +911,8 @@ static const struct config mainnet_config = {
 
 	.use_dns = true,
 
+	/* Excplicitly turns 'on' or 'off' IP discovery feature. */
+	.ip_discovery = OPT_AUTOBOOL_AUTO,
 	/* Turn off IP address announcement discovered via peer `remote_addr` */
 	.disable_ip_discovery = false,
 
@@ -1211,9 +1215,13 @@ static void register_opts(struct lightningd *ld)
 	opt_register_arg("--announce-addr", opt_add_announce_addr, NULL,
 			 ld,
 			 "Set an IP address (v4 or v6) or .onion v3 to announce, but not listen on");
+
 	opt_register_noarg("--disable-ip-discovery", opt_set_bool,
 			 &ld->config.disable_ip_discovery,
 			 "Turn off announcement of discovered public IPs");
+	opt_register_arg("--announce-addr-discovered", opt_set_autobool_arg, opt_show_autobool,
+			 &ld->config.ip_discovery,
+			 "Explicitly turns IP discovery 'on' or 'off'.");
 
 	opt_register_noarg("--offline", opt_set_offline, ld,
 			   "Start in offline-mode (do not automatically reconnect and do not accept incoming connections)");

tests/test_connection.py

@@ -73,7 +73,8 @@ def test_remote_addr(node_factory, bitcoind):
     # don't announce anything per se
     opts = {'may_reconnect': True,
             'dev-allow-localhost': None,
-            'dev-no-reconnect': None}
+            'dev-no-reconnect': None,
+            'ip-discovery': True}
     l1, l2, l3 = node_factory.get_nodes(3, opts)
 
     # Disable announcing local autobind addresses with dev-allow-localhost.