jsonrpc: adds optional remote_addr to listpeers

Changelog-Added: jsonrpc: adds optional `remote_addr` to listpeers

doc/lightning-listpeers.7.md

@@ -159,6 +159,7 @@ If **connected** is *true*:
   - **netaddr** (array of strings): A single entry array:
     - address, e.g. 1.2.3.4:1234
   - **features** (hex): bitmap of BOLT #9 features from peer's INIT message
+  - **remote_addr** (string, optional): The public IPv4/6 address the peer sees us from, e.g. 1.2.3.4:1234
 
 [comment]: # (GENERATE-FROM-SCHEMA-END)
 
@@ -380,4 +381,4 @@ Main web site: <https://github.com/ElementsProject/lightning> Lightning
 RFC site (BOLT \#9):
 <https://github.com/lightningnetwork/lightning-rfc/blob/master/09-features.md>
 
-[comment]: # ( SHA256STAMP:4f76b5ac19d3dfdaf3d04f5dd5de2312a2ab0ccffe779508c416aaf6e644612a)
+[comment]: # ( SHA256STAMP:e6829e8ced923131b95bcfa4f366dd04286fe85485039e9ebc89e79899937df6)

doc/schemas/listpeers.schema.json

@@ -1114,6 +1114,10 @@
                     "description": "address, e.g. 1.2.3.4:1234"
                   }
                 },
+                "remote_addr": {
+                  "type": "string",
+                  "description": "The public IPv4/6 address the peer sees us from, e.g. 1.2.3.4:1234"
+                },
                 "features": {
                   "type": "hex",
                   "description": "bitmap of BOLT #9 features from peer's INIT message"

lightningd/peer_control.c

@@ -97,6 +97,7 @@ struct peer *new_peer(struct lightningd *ld, u64 dbid,
 	peer->uncommitted_channel = NULL;
 	peer->addr = *addr;
 	peer->connected_incoming = connected_incoming;
+	peer->remote_addr = NULL;
 	peer->their_features = NULL;
 	list_head_init(&peer->channels);
 	peer->direction = node_id_idx(&peer->ld->id, &peer->id);
@@ -1154,6 +1155,9 @@ void peer_connected(struct lightningd *ld, const u8 *msg)
 	/* Update peer address and direction */
 	peer->addr = hook_payload->addr;
 	peer->connected_incoming = hook_payload->incoming;
+	if (peer->remote_addr)
+		tal_free(peer->remote_addr);
+	peer->remote_addr = NULL;
 	peer_update_features(peer, their_features);
 
 	tal_steal(peer, hook_payload);
@@ -1172,6 +1176,8 @@ void peer_connected(struct lightningd *ld, const u8 *msg)
 	if (hook_payload->remote_addr) {
 		log_peer_info(ld->log, &id, "Peer says it sees our address as: %s",
 			      fmt_wireaddr(tmpctx, hook_payload->remote_addr));
+		peer->remote_addr = tal_dup(peer, struct wireaddr,
+					    hook_payload->remote_addr);
 		/* Currently only from peers we have a channel with, until we
 		 * do stuff like probing for remote_addr to a random node. */
 		if (!list_empty(&peer->channels))
@@ -1671,6 +1677,10 @@ static void json_add_peer(struct lightningd *ld,
 					       struct wireaddr_internal,
 					       &p->addr));
 		json_array_end(response);
+		/* If peer reports our IP remote_addr, add that here */
+		if (p->remote_addr)
+			json_add_string(response, "remote_addr",
+					fmt_wireaddr(response, p->remote_addr));
 		json_add_hex_talarr(response, "features", p->their_features);
 	}
 

lightningd/peer_control.h

@@ -40,6 +40,9 @@ struct peer {
 	struct wireaddr_internal addr;
 	bool connected_incoming;
 
+	/* They send what they see as our address as remote_addr */
+	struct wireaddr *remote_addr;
+
 	/* We keep a copy of their feature bits */
 	const u8 *their_features;
 

tests/test_connection.py

@@ -86,7 +86,9 @@ def test_remote_addr(node_factory, bitcoind):
     l2.start()
 
     l2.rpc.connect(l1.info['id'], 'localhost', l1.port)
-    l2.daemon.wait_for_log("Peer says it sees our address as: 127.0.0.1:[0-9]{5}")
+    logmsg = l2.daemon.wait_for_log("Peer says it sees our address as: 127.0.0.1:[0-9]{5}")
+    # check 'listpeers' contains the 'remote_addr' as logged
+    assert logmsg.endswith(l2.rpc.listpeers()['peers'][0]['remote_addr'])
 
     # Fund first channel so initial node_announcement is send
     # and also check no addresses have been announced yet