From b3a2a0623c018cdb34745b4585ad64c5c04dc302 Mon Sep 17 00:00:00 2001
From: Rusty Russell <rusty@rustcorp.com.au>
Date: Tue, 23 May 2017 21:47:34 +0930
Subject: [PATCH] lightningd: set up reconnect timer if we don't want to forget
 peer.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 lightningd/new_connection.c |  5 ++++
 lightningd/new_connection.h |  1 +
 lightningd/peer_control.c   | 59 ++++++++++++++++++++++++++++++-------
 3 files changed, 54 insertions(+), 11 deletions(-)

diff --git a/lightningd/new_connection.c b/lightningd/new_connection.c
index 4b2b32610..afffa74ad 100644
--- a/lightningd/new_connection.c
+++ b/lightningd/new_connection.c
@@ -248,3 +248,8 @@ struct io_plan *connection_in(struct io_conn *conn, struct lightningd *ld)
 	}
 	return hsm_then_handshake(conn, ld, c);
 }
+
+const struct pubkey *connection_known_id(const struct connection *c)
+{
+	return c->known_id;
+}
diff --git a/lightningd/new_connection.h b/lightningd/new_connection.h
index 5a17ad35a..428c79d20 100644
--- a/lightningd/new_connection.h
+++ b/lightningd/new_connection.h
@@ -22,4 +22,5 @@ struct io_plan *connection_out(struct io_conn *conn,
 
 struct io_plan *connection_in(struct io_conn *conn, struct lightningd *ld);
 
+const struct pubkey *connection_known_id(const struct connection *c);
 #endif /* LIGHTNING_LIGHTNINGD_NEW_CONNECTION_H */
diff --git a/lightningd/peer_control.c b/lightningd/peer_control.c
index 0a72f12c4..512be11a3 100644
--- a/lightningd/peer_control.c
+++ b/lightningd/peer_control.c
@@ -13,6 +13,7 @@
 #include <daemon/invoice.h>
 #include <daemon/jsonrpc.h>
 #include <daemon/log.h>
+#include <daemon/timeout.h>
 #include <errno.h>
 #include <inttypes.h>
 #include <lightningd/build_utxos.h>
@@ -50,9 +51,55 @@ static void destroy_peer(struct peer *peer)
 		close(peer->fd);
 }
 
+static struct peer *peer_by_pubkey(struct lightningd *ld, const struct pubkey *id)
+{
+	struct peer *peer;
+	list_for_each(&ld->peers, peer, list) {
+		if (pubkey_cmp(id, peer->id) == 0)
+			return peer;
+	}
+	return NULL;
+}
+
+/* Mutual recursion, sets timer. */
+static void peer_reconnect(struct peer *peer);
+
+static void reconnect_failed(struct lightningd_state *dstate,
+			     struct connection *c)
+{
+	/* Figure out what peer, set reconnect timer. */
+	struct lightningd *ld = ld_from_dstate(dstate);
+	struct peer *peer = peer_by_pubkey(ld, connection_known_id(c));
+
+	tal_free(c);
+	peer_reconnect(peer);
+}
+
+static void try_reconnect(struct peer *peer)
+{
+	struct connection *c;
+	struct netaddr *addrs;
+
+	/* We may already be reconnected (another incoming connection) */
+	if (peer->fd != -1) {
+		log_debug(peer->log, "try_reconnect: already reconnected");
+		return;
+	}
+
+	c = new_connection(peer, peer->ld, NULL, peer->id);
+
+	/* FIXME: Combine known address with gossip addresses and possibly
+	 * DNS seed addresses. */
+	addrs = tal_dup_arr(c, struct netaddr, &peer->netaddr, 1, 0);
+	multiaddress_connect(&peer->ld->dstate, addrs,
+			     connection_out, reconnect_failed, c);
+}
+
 static void peer_reconnect(struct peer *peer)
 {
-	/* FIXME: Set timer, etc. */
+	new_reltimer(&peer->ld->dstate.timers,
+		     peer, peer->ld->dstate.config.poll_time,
+		     try_reconnect, peer);
 }
 
 void peer_fail(struct peer *peer, const char *fmt, ...)
@@ -967,16 +1014,6 @@ fail:
 	tal_free(hend);
 }
 
-static struct peer *peer_by_pubkey(struct lightningd *ld, const struct pubkey *id)
-{
-	struct peer *peer;
-	list_for_each(&ld->peers, peer, list) {
-		if (pubkey_cmp(id, peer->id) == 0)
-			return peer;
-	}
-	return NULL;
-}
-
 /*
  * A catchall in case outgoing peer disconnects before getting fwd.
  *