gossipd: Implement `gossip_routing_failure` for master to report routing failures.

gossipd/Makefile

@@ -56,7 +56,8 @@ GOSSIPD_COMMON_OBJS :=				\
 	common/wire_error.o			\
 	hsmd/client.o				\
 	hsmd/gen_hsm_client_wire.o		\
-	lightningd/gossip_msg.o
+	lightningd/gossip_msg.o			\
+	wire/gen_onion_wire.o
 
 $(LIGHTNINGD_GOSSIP_OBJS) $(LIGHTNINGD_GOSSIP_CLIENT_OBJS): $(LIGHTNINGD_HEADERS) $(LIGHTNINGD_GOSSIP_HEADERS)
 

gossipd/gossip.c

@@ -1883,6 +1883,27 @@ fail:
 	tal_free(tmpctx);
 	return daemon_conn_read_next(conn, &daemon->master);
 }
+static struct io_plan *handle_routing_failure(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)
 {
@@ -1932,6 +1953,9 @@ static struct io_plan *recv_req(struct io_conn *conn, struct daemon_conn *master
 	case WIRE_GOSSIP_DISABLE_CHANNEL:
 		return handle_disable_channel(conn, daemon, master->msg_in);
 
+	case WIRE_GOSSIP_ROUTING_FAILURE:
+		return handle_routing_failure(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
@@ -195,3 +196,9 @@ gossip_disable_channel,3019
 gossip_disable_channel,,short_channel_id,struct short_channel_id
 gossip_disable_channel,,direction,u8
 gossip_disable_channel,,active,bool
+
+# master->gossipd a routing failure occurred
+gossip_routing_failure,3021
+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
@@ -238,6 +239,12 @@ get_or_make_connection(struct routing_state *rstate,
 	return nc;
 }
 
+static void delete_connection(struct routing_state *rstate,
+			      const struct node_connection *connection)
+{
+	tal_free(connection);
+}
+
 struct node_connection *half_add_connection(
 					    struct routing_state *rstate,
 					    const struct pubkey *from,
@@ -1007,3 +1014,99 @@ struct route_hop *get_route(tal_t *ctx, struct routing_state *rstate,
 	/* FIXME: Shadow route! */
 	return hops;
 }
+
+/* Get the struct node_connection matching the short_channel_id,
+ * which must be an out connection of the given node. */
+static struct node_connection *
+get_out_node_connection_of(struct routing_state *rstate,
+			   const struct node *node,
+			   const struct short_channel_id *short_channel_id)
+{
+	int i;
+
+	for (i = 0; i < tal_count(node->out); ++i) {
+		if (short_channel_id_eq(&node->out[i]->short_channel_id, short_channel_id))
+			return node->out[i];
+	}
+
+	return NULL;
+}
+
+/**
+ * routing_failure_on_nc - Handle routing failure on a specific
+ * node_connection.
+ */
+static void routing_failure_on_nc(struct routing_state *rstate,
+				  enum onion_type failcode,
+				  struct node_connection *nc)
+{
+	/* BOLT #4:
+	 *
+	 * - if the PERM bit is NOT set:
+	 *   - SHOULD restore the channels as it receives new `channel_update`s.
+	 */
+	if (failcode & PERM)
+		nc->active = false;
+	else
+		delete_connection(rstate, nc);
+}
+
+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 *nc;
+	int i;
+
+	status_trace("Received routing failure 0x%04x (%s), "
+		     "erring node %s, "
+		     "channel %s",
+		     (int) failcode, onion_type_name(failcode),
+		     type_to_string(tmpctx, struct pubkey, erring_node_pubkey),
+		     type_to_string(tmpctx, struct short_channel_id, scid));
+
+	node = get_node(rstate, erring_node_pubkey);
+	if (!node) {
+		status_trace("UNUSUAL routing_failure: "
+			     "Erring node %s not in map",
+			     type_to_string(tmpctx, struct pubkey,
+					    erring_node_pubkey));
+		/* No node, so no channel, so any channel_update
+		 * can also be ignored. */
+		goto out;
+	}
+
+	/* BOLT #4:
+	 *
+	 * - if the NODE bit is set:
+	 *   - SHOULD remove all channels connected with the erring node from
+	 *   consideration.
+	 *
+	 */
+	if (failcode & NODE) {
+		for (i = 0; i < tal_count(node->in); ++i)
+			routing_failure_on_nc(rstate, failcode, node->in[i]);
+		for (i = 0; i < tal_count(node->out); ++i)
+			routing_failure_on_nc(rstate, failcode, node->out[i]);
+	} else {
+		nc = get_out_node_connection_of(rstate, node, scid);
+		if (nc)
+			routing_failure_on_nc(rstate, failcode, nc);
+		else
+			status_trace("UNUSUAL routing_failure: "
+				     "Channel %s not an out channel "
+				     "of node %s",
+				     type_to_string(tmpctx,
+						    struct short_channel_id,
+						    scid),
+				     type_to_string(tmpctx, struct pubkey,
+						    erring_node_pubkey));
+	}
+
+	/* FIXME: if UPDATE is set, apply the channel update. */
+out:
+	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
@@ -148,6 +149,11 @@ 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 */

gossipd/test/run-bench-find_route.c

@@ -63,6 +63,9 @@ u8 fromwire_u8(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 /* Generated stub for fromwire_wireaddr */
 bool fromwire_wireaddr(const u8 **cursor UNNEEDED, size_t *max UNNEEDED, struct wireaddr *addr UNNEEDED)
 { fprintf(stderr, "fromwire_wireaddr called!\n"); abort(); }
+/* Generated stub for onion_type_name */
+const char *onion_type_name(int e UNNEEDED)
+{ fprintf(stderr, "onion_type_name called!\n"); abort(); }
 /* Generated stub for queue_broadcast */
 bool queue_broadcast(struct broadcast_state *bstate UNNEEDED,
 			     const int type UNNEEDED,

gossipd/test/run-find_route-specific.c

@@ -34,6 +34,9 @@ u8 fromwire_u8(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 /* Generated stub for fromwire_wireaddr */
 bool fromwire_wireaddr(const u8 **cursor UNNEEDED, size_t *max UNNEEDED, struct wireaddr *addr UNNEEDED)
 { fprintf(stderr, "fromwire_wireaddr called!\n"); abort(); }
+/* Generated stub for onion_type_name */
+const char *onion_type_name(int e UNNEEDED)
+{ fprintf(stderr, "onion_type_name called!\n"); abort(); }
 /* Generated stub for queue_broadcast */
 bool queue_broadcast(struct broadcast_state *bstate UNNEEDED,
 			     const int type UNNEEDED,

gossipd/test/run-find_route.c

@@ -27,6 +27,9 @@ u8 fromwire_u8(const u8 **cursor UNNEEDED, size_t *max UNNEEDED)
 /* Generated stub for fromwire_wireaddr */
 bool fromwire_wireaddr(const u8 **cursor UNNEEDED, size_t *max UNNEEDED, struct wireaddr *addr UNNEEDED)
 { fprintf(stderr, "fromwire_wireaddr called!\n"); abort(); }
+/* Generated stub for onion_type_name */
+const char *onion_type_name(int e UNNEEDED)
+{ fprintf(stderr, "onion_type_name called!\n"); abort(); }
 /* Generated stub for queue_broadcast */
 bool queue_broadcast(struct broadcast_state *bstate UNNEEDED,
 			     const int type UNNEEDED,

lightningd/gossip_control.c

@@ -110,6 +110,7 @@ static unsigned gossip_msg(struct subd *gossip, const u8 *msg, const int *fds)
 	case WIRE_GOSSIP_SEND_GOSSIP:
 	case WIRE_GOSSIP_GET_TXOUT_REPLY:
 	case WIRE_GOSSIP_DISABLE_CHANNEL:
+	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: