From ffddb91e3e69827fca2a6ceaa9d6a7e0a59510bc Mon Sep 17 00:00:00 2001
From: Rusty Russell <rusty@rustcorp.com.au>
Date: Tue, 22 Aug 2017 14:36:37 +0930
Subject: [PATCH] gossipd: hand in chain_hash.

This will be needed for gossip messages.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 lightningd/gossip/gossip.c        | 21 ++++++++++++---------
 lightningd/gossip/gossip_wire.csv |  1 +
 lightningd/gossip_control.c       |  3 ++-
 3 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/lightningd/gossip/gossip.c b/lightningd/gossip/gossip.c
index de067d0dd..ae3cb0a87 100644
--- a/lightningd/gossip/gossip.c
+++ b/lightningd/gossip/gossip.c
@@ -653,10 +653,21 @@ static struct io_plan *ping_req(struct io_conn *conn, struct daemon *daemon,
 static struct io_plan *gossip_init(struct daemon_conn *master,
 				   struct daemon *daemon, u8 *msg)
 {
-	if (!fromwire_gossipctl_init(msg, NULL, &daemon->broadcast_interval)) {
+	struct sha256_double chain_hash;
+	struct log_book *log_book;
+	struct log *base_log;
+
+	if (!fromwire_gossipctl_init(msg, NULL, &daemon->broadcast_interval,
+				     &chain_hash)) {
 		status_failed(WIRE_GOSSIPSTATUS_INIT_FAILED,
 			      "Unable to parse init message");
 	}
+	/* Do not log absolutely anything, stdout is now a socket
+	 * connected to some other daemon. */
+	log_book = new_log_book(daemon, 2 * 1024 * 1024, LOG_BROKEN + 1);
+	base_log =
+	    new_log(daemon, log_book, "lightningd_gossip(%u):", (int)getpid());
+	daemon->rstate = new_routing_state(daemon, base_log);
 	return daemon_conn_read_next(master->conn, master);
 }
 
@@ -773,8 +784,6 @@ static void master_gone(struct io_conn *unused, struct daemon_conn *dc)
 int main(int argc, char *argv[])
 {
 	struct daemon *daemon;
-	struct log_book *log_book;
-	struct log *base_log;
 
 	subdaemon_debug(argc, argv);
 
@@ -787,12 +796,6 @@ int main(int argc, char *argv[])
 						 SECP256K1_CONTEXT_SIGN);
 
 	daemon = tal(NULL, struct daemon);
-	/* Do not log absolutely anything, stdout is now a socket
-	 * connected to some other daemon. */
-	log_book = new_log_book(daemon, 2 * 1024 * 1024, LOG_BROKEN + 1);
-	base_log =
-	    new_log(daemon, log_book, "lightningd_gossip(%u):", (int)getpid());
-	daemon->rstate = new_routing_state(daemon, base_log);
 	list_head_init(&daemon->peers);
 	timers_init(&daemon->timers, time_mono());
 	daemon->broadcast_interval = 30000;
diff --git a/lightningd/gossip/gossip_wire.csv b/lightningd/gossip/gossip_wire.csv
index 51a7baca4..f12602cf9 100644
--- a/lightningd/gossip/gossip_wire.csv
+++ b/lightningd/gossip/gossip_wire.csv
@@ -23,6 +23,7 @@ gossipstatus_peer_failed,,err,len*u8
 # Initialize the gossip daemon
 gossipctl_init,0
 gossipctl_init,,broadcast_interval,4
+gossipctl_init,,chain_hash,struct sha256_double
 
 # These take an fd, but have no response
 # (if it is to move onto a channel, we get a status msg).
diff --git a/lightningd/gossip_control.c b/lightningd/gossip_control.c
index f26877311..166d29230 100644
--- a/lightningd/gossip_control.c
+++ b/lightningd/gossip_control.c
@@ -149,7 +149,8 @@ void gossip_init(struct lightningd *ld)
 	if (!ld->gossip)
 		err(1, "Could not subdaemon gossip");
 
-	init = towire_gossipctl_init(tmpctx, ld->broadcast_interval);
+	init = towire_gossipctl_init(tmpctx, ld->broadcast_interval,
+				     &ld->chainparams->genesis_blockhash);
 	subd_send_msg(ld->gossip, init);
 	tal_free(tmpctx);
 }