From dba7f9002f261ab46efa1f3655e64f314dab75ab Mon Sep 17 00:00:00 2001
From: Rusty Russell <rusty@rustcorp.com.au>
Date: Tue, 24 Jul 2018 15:48:58 +0930
Subject: [PATCH] gossipd: provide connectd with address resolution.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 connectd/connect.c               | 27 +++++++++++++++++++++++++--
 connectd/connect_gossip_wire.csv | 10 ++++++++++
 gossipd/gossip.c                 | 31 ++++++++++++++++++++++++++++++-
 tests/test_lightningd.py         |  1 -
 4 files changed, 65 insertions(+), 4 deletions(-)

diff --git a/connectd/connect.c b/connectd/connect.c
index d50207dcc..763913135 100644
--- a/connectd/connect.c
+++ b/connectd/connect.c
@@ -1505,8 +1505,31 @@ seed_resolve_addr(const tal_t *ctx, const struct pubkey *id,
 static struct wireaddr_internal *
 gossip_resolve_addr(const tal_t *ctx, const struct pubkey *id)
 {
-	/* FIXME: Ask gossipd! */
-	return NULL;
+	u8 *msg;
+	struct wireaddr *addrs;
+	struct wireaddr_internal *addr;
+
+	msg = towire_gossip_get_addrs(NULL, id);
+	if (!wire_sync_write(GOSSIPCTL_FD, take(msg)))
+		status_failed(STATUS_FAIL_INTERNAL_ERROR,
+			      "Failed writing to gossipctl: %s",
+			      strerror(errno));
+
+	msg = wire_sync_read(tmpctx, GOSSIPCTL_FD);
+	if (!fromwire_gossip_get_addrs_reply(tmpctx, msg, &addrs))
+		status_failed(STATUS_FAIL_INTERNAL_ERROR,
+			      "Failed parsing get_addrs_reply gossipctl: %s",
+			      tal_hex(tmpctx, msg));
+
+	if (!addrs)
+		return NULL;
+
+	/* FIXME: Don't just take first address! */
+	addr = tal(ctx, struct wireaddr_internal);
+	addr->itype = ADDR_INTERNAL_WIREADDR;
+	addr->u.wireaddr = addrs[0];
+
+	return addr;
 }
 
 static void try_reach_peer(struct daemon *daemon, const struct pubkey *id,
diff --git a/connectd/connect_gossip_wire.csv b/connectd/connect_gossip_wire.csv
index dba261d4b..76f829e56 100644
--- a/connectd/connect_gossip_wire.csv
+++ b/connectd/connect_gossip_wire.csv
@@ -1,3 +1,5 @@
+#include <common/wireaddr.h>
+
 # Communication between gossipd and connectd.
 gossip_new_peer,4000
 gossip_new_peer,,id,struct pubkey
@@ -9,3 +11,11 @@ gossip_new_peer,,initial_routing_sync,bool
 # if success: + fd.
 gossip_new_peer_reply,4100
 gossip_new_peer_reply,,success,bool
+
+# Connectd asks gossipd for any known addresses for that node.
+gossip_get_addrs,4001
+gossip_get_addrs,,id,struct pubkey
+
+gossip_get_addrs_reply,4101
+gossip_get_addrs_reply,,num,u16
+gossip_get_addrs_reply,,addrs,num*struct wireaddr
diff --git a/gossipd/gossip.c b/gossipd/gossip.c
index 88ba4d569..296d8355c 100644
--- a/gossipd/gossip.c
+++ b/gossipd/gossip.c
@@ -2164,6 +2164,31 @@ static struct io_plan *recv_req(struct io_conn *conn, struct daemon_conn *master
 		      t, tal_hex(tmpctx, master->msg_in));
 }
 
+static struct io_plan *connectd_get_address(struct io_conn *conn,
+					    struct daemon *daemon,
+					    const u8 *msg)
+{
+	struct pubkey id;
+	struct node *node;
+	const struct wireaddr *addrs;
+
+	if (!fromwire_gossip_get_addrs(msg, &id)) {
+		status_broken("Bad gossip_get_addrs msg from connectd: %s",
+			      tal_hex(tmpctx, msg));
+		return io_close(conn);
+	}
+
+	node = get_node(daemon->rstate, &id);
+	if (node)
+		addrs = node->addresses;
+	else
+		addrs = NULL;
+
+	daemon_conn_send(&daemon->connectd,
+			 take(towire_gossip_get_addrs_reply(NULL, addrs)));
+	return daemon_conn_read_next(conn, &daemon->connectd);
+}
+
 static struct io_plan *connectd_req(struct io_conn *conn,
 				    struct daemon_conn *connectd)
 {
@@ -2174,8 +2199,12 @@ static struct io_plan *connectd_req(struct io_conn *conn,
 	case WIRE_GOSSIP_NEW_PEER:
 		return connectd_new_peer(conn, daemon, connectd->msg_in);
 
-	/* We send this, don't receive it. */
+	case WIRE_GOSSIP_GET_ADDRS:
+		return connectd_get_address(conn, daemon, connectd->msg_in);
+
+	/* We send these, don't receive them. */
 	case WIRE_GOSSIP_NEW_PEER_REPLY:
+	case WIRE_GOSSIP_GET_ADDRS_REPLY:
 		break;
 	}
 
diff --git a/tests/test_lightningd.py b/tests/test_lightningd.py
index efb138388..ecc5e9595 100644
--- a/tests/test_lightningd.py
+++ b/tests/test_lightningd.py
@@ -695,7 +695,6 @@ class LightningDTests(BaseLightningDTests):
                                l1.rpc.connect, '032cf15d1ad9c4a08d26eab1918f732d8ef8fdc6abb9640bf3db174372c491304e', 'localhost', l2.port)
 
     @unittest.skipIf(not DEVELOPER, "needs --dev-allow-localhost")
-    @unittest.skip("FIXME: Re-enable once gossipd gives out addresses to connectd")
     def test_connect_by_gossip(self):
         """Test connecting to an unknown peer using node gossip
         """