gossip: Implement gossip_routing_failure for master to report routi…

…ng failures.

gossipd/gossip.c

@@ -1769,6 +1769,28 @@ static struct io_plan *handle_txout_reply(struct io_conn *conn,
 	return daemon_conn_read_next(conn, &daemon->master);
 }
 
+static struct io_plan *routing_failure_req(struct io_conn *conn,
+					   struct daemon *daemon,
+					   const u8 *msg)
+{
+	struct pubkey erring_node;
+	struct short_channel_id erring_channel;
+	u16 failcode;
+
+	if (!fromwire_gossip_routing_failure(msg, NULL,
+					     &erring_node,
+					     &erring_channel,
+					     &failcode))
+		master_badmsg(WIRE_GOSSIP_ROUTING_FAILURE, msg);
+
+	routing_failure(daemon->rstate,
+			&erring_node,
+			&erring_channel,
+			(enum onion_type) failcode);
+
+	return daemon_conn_read_next(conn, &daemon->master);
+}
+
 static struct io_plan *recv_req(struct io_conn *conn, struct daemon_conn *master)
 {
 	struct daemon *daemon = container_of(master, struct daemon, master);
@@ -1814,6 +1836,9 @@ static struct io_plan *recv_req(struct io_conn *conn, struct daemon_conn *master
 	case WIRE_GOSSIP_GET_TXOUT_REPLY:
 		return handle_txout_reply(conn, daemon, master->msg_in);
 
+	case WIRE_GOSSIP_ROUTING_FAILURE:
+		return routing_failure_req(conn, daemon, master->msg_in);
+
 	/* We send these, we don't receive them */
 	case WIRE_GOSSIPCTL_RELEASE_PEER_REPLY:
 	case WIRE_GOSSIPCTL_RELEASE_PEER_REPLYFAIL:

gossipd/gossip_wire.csv

@@ -1,5 +1,6 @@
 #include <common/cryptomsg.h>
 #include <common/wireaddr.h>
+#include <wire/gen_onion_wire.h>
 
 # Initialize the gossip daemon.
 gossipctl_init,3000
@@ -183,3 +184,8 @@ gossip_get_txout_reply,,short_channel_id,struct short_channel_id
 gossip_get_txout_reply,,len,u16
 gossip_get_txout_reply,,outscript,len*u8
 
+# master->gossipd a routing failure occurred
+gossip_routing_failure,3019
+gossip_routing_failure,,erring_node,struct pubkey
+gossip_routing_failure,,erring_channel,struct short_channel_id
+gossip_routing_failure,,failcode,u16

gossipd/routing.c

@@ -13,6 +13,7 @@
 #include <common/type_to_string.h>
 #include <common/wireaddr.h>
 #include <inttypes.h>
+#include <wire/gen_onion_wire.h>
 #include <wire/gen_peer_wire.h>
 
 #ifndef SUPERVERBOSE
@@ -225,6 +226,7 @@ get_or_make_connection(struct routing_state *rstate,
 	nc->dst = to;
 	nc->channel_announcement = NULL;
 	nc->channel_update = NULL;
+	nc->perminactive = false;
 
 	/* Hook it into in/out arrays. */
 	i = tal_count(to->in);
@@ -800,7 +802,8 @@ void handle_channel_update(struct routing_state *rstate, const u8 *update)
 	c->htlc_minimum_msat = htlc_minimum_msat;
 	c->base_fee = fee_base_msat;
 	c->proportional_fee = fee_proportional_millionths;
-	c->active = (flags & ROUTING_FLAGS_DISABLED) == 0;
+	if (!c->perminactive)
+		c->active = (flags & ROUTING_FLAGS_DISABLED) == 0;
 	status_trace("Channel %s(%d) was updated.",
 		     type_to_string(trc, struct short_channel_id,
 				    &short_channel_id),
@@ -994,3 +997,85 @@ struct route_hop *get_route(tal_t *ctx, struct routing_state *rstate,
 	/* FIXME: Shadow route! */
 	return hops;
 }
+
+/* Get a singleton array of struct node_connection containing
+ * the channel matching the short_channel_id, which must be
+ * an out connection of the given node. */
+static struct node_connection **
+get_out_node_connection_of(const tal_t *ctx,
+			   struct routing_state *rstate,
+			   const struct node *node,
+			   const struct short_channel_id *short_channel_id)
+{
+	struct node_connection **ncs;
+	int i;
+
+	for (i = 0; i < tal_count(node->out); ++i) {
+		if (structeq(&node->out[i]->short_channel_id, short_channel_id)) {
+			ncs = tal_arr(ctx, struct node_connection*, 1);
+			ncs[0] = node->out[i];
+			return ncs;
+		}
+	}
+
+	return NULL;
+}
+/* Get an array of all channels connected to this node. */
+static struct node_connection **
+get_all_node_connections_of(const tal_t *ctx,
+			    struct routing_state *rstate,
+			    const struct node *node)
+{
+	struct node_connection **ncs;
+
+	u64 num_ins = tal_count(node->in);
+	u64 num_outs = tal_count(node->out);
+	u64 num = num_ins + num_outs;
+
+	ncs = tal_arr(ctx, struct node_connection*, num);
+	memcpy(&ncs[0], node->in, num_ins * sizeof(struct node_connection*));
+	memcpy(&ncs[num_ins], node->out, num_outs * sizeof(struct node_connection*));
+
+	return ncs;
+}
+
+void routing_failure(struct routing_state *rstate,
+		     const struct pubkey *erring_node_pubkey,
+		     const struct short_channel_id *scid,
+		     enum onion_type failcode)
+{
+	const tal_t *tmpctx = tal_tmpctx(rstate);
+	struct node *node;
+	struct node_connection **ncs;
+	int i;
+
+	node = get_node(rstate, erring_node_pubkey);
+
+	/* Get all affected channels. */
+	/* BOLT #4:
+	 *
+	 * - if the NODE bit is set:
+	 *   - SHOULD remove all channels connected with the erring node from
+	 *   consideration.
+	 *
+	 */
+	if ((failcode & NODE) != 0)
+		ncs = get_all_node_connections_of(tmpctx, rstate, node);
+	else
+		ncs = get_out_node_connection_of(tmpctx, rstate, node, scid);
+
+	for (i = 0; i < tal_count(ncs); ++i) {
+		ncs[i]->active = false;
+		/* BOLT #4:
+		 *
+		 * - if the PERM bit is NOT set:
+		 *   - SHOULD restore the channels as it receives new `channel_update`s.
+		 */
+		if ((failcode & PERM) != 0)
+			ncs[i]->perminactive = true;
+	}
+
+	/* FIXME: if UPDATE is set, apply the channel update. */
+
+	tal_free(tmpctx);
+}

gossipd/routing.h

@@ -4,6 +4,7 @@
 #include <bitcoin/pubkey.h>
 #include <ccan/htable/htable_type.h>
 #include <gossipd/broadcast.h>
+#include <wire/gen_onion_wire.h>
 #include <wire/wire.h>
 
 #define ROUTING_MAX_HOPS 20
@@ -21,6 +22,8 @@ struct node_connection {
 
 	/* Is this connection active? */
 	bool active;
+	/* Is this connection permanently inactive? */
+	bool perminactive;
 
 	s64 last_timestamp;
 
@@ -148,6 +151,11 @@ struct route_hop *get_route(tal_t *ctx, struct routing_state *rstate,
 			    const struct pubkey *destination,
 			    const u32 msatoshi, double riskfactor,
 			    u32 final_cltv);
+/* Disable channel(s) based on the given routing failure. */
+void routing_failure(struct routing_state *rstate,
+		     const struct pubkey *erring_node,
+		     const struct short_channel_id *erring_channel,
+		     enum onion_type failcode);
 
 /* Utility function that, given a source and a destination, gives us
  * the direction bit the matching channel should get */

lightningd/gossip_control.c

@@ -109,6 +109,7 @@ static unsigned gossip_msg(struct subd *gossip, const u8 *msg, const int *fds)
 	case WIRE_GOSSIP_GET_UPDATE:
 	case WIRE_GOSSIP_SEND_GOSSIP:
 	case WIRE_GOSSIP_GET_TXOUT_REPLY:
+	case WIRE_GOSSIP_ROUTING_FAILURE:
 	/* This is a reply, so never gets through to here. */
 	case WIRE_GOSSIP_GET_UPDATE_REPLY:
 	case WIRE_GOSSIP_GETNODES_REPLY: