jsonrpc: Implemented `getchannels` JSON-RPC call

lightningd/gossip/gossip.c

@@ -476,6 +476,40 @@ static struct io_plan *getroute_req(struct io_conn *conn, struct daemon *daemon,
 	return daemon_conn_read_next(conn, &daemon->master);
 }
 
+static struct io_plan *getchannels_req(struct io_conn *conn, struct daemon *daemon,
+				    u8 *msg)
+{
+	tal_t *tmpctx = tal_tmpctx(daemon);
+	u8 *out;
+	size_t j, num_chans = 0;
+	struct gossip_getchannels_entry *entries;
+	struct node *n;
+	struct node_map_iter i;
+
+	entries = tal_arr(tmpctx, struct gossip_getchannels_entry, num_chans);
+	n = node_map_first(daemon->rstate->nodes, &i);
+	while (n != NULL) {
+		for (j=0; j<tal_count(n->out); j++){
+			tal_resize(&entries, num_chans + 1);
+			entries[num_chans].source = n->out[j]->src->id;
+			entries[num_chans].destination = n->out[j]->dst->id;
+			entries[num_chans].active = n->out[j]->active;
+			entries[num_chans].delay = n->out[j]->delay;
+			entries[num_chans].fee_per_kw = n->out[j]->proportional_fee;
+			entries[num_chans].last_update_timestamp = n->out[j]->last_timestamp;
+			entries[num_chans].flags = n->out[j]->flags;
+			entries[num_chans].short_channel_id = n->out[j]->short_channel_id;
+			num_chans++;
+		}
+		n = node_map_next(daemon->rstate->nodes, &i);
+	}
+
+	out = towire_gossip_getchannels_reply(daemon, entries);
+	daemon_conn_send(&daemon->master, take(out));
+	tal_free(tmpctx);
+	return daemon_conn_read_next(conn, &daemon->master);
+}
+
 static struct io_plan *getnodes(struct io_conn *conn, struct daemon *daemon)
 {
 	tal_t *tmpctx = tal_tmpctx(daemon);
@@ -521,9 +555,13 @@ static struct io_plan *recv_req(struct io_conn *conn, struct daemon_conn *master
 	case WIRE_GOSSIP_GETROUTE_REQUEST:
 		return getroute_req(conn, daemon, daemon->master.msg_in);
 
+	case WIRE_GOSSIP_GETCHANNELS_REQUEST:
+		return getchannels_req(conn, daemon, daemon->master.msg_in);
+
 	case WIRE_GOSSIPCTL_RELEASE_PEER_REPLY:
 	case WIRE_GOSSIP_GETNODES_REPLY:
 	case WIRE_GOSSIP_GETROUTE_REPLY:
+	case WIRE_GOSSIP_GETCHANNELS_REPLY:
 	case WIRE_GOSSIPSTATUS_INIT_FAILED:
 	case WIRE_GOSSIPSTATUS_BAD_NEW_PEER_REQUEST:
 	case WIRE_GOSSIPSTATUS_BAD_RELEASE_REQUEST:

lightningd/gossip/gossip_wire.csv

@@ -71,3 +71,9 @@ gossip_getroute_request,70,riskfactor,u16
 gossip_getroute_reply,106
 gossip_getroute_reply,0,num_hops,u16
 gossip_getroute_reply,2,hops,num_hops*struct route_hop
+
+gossip_getchannels_request,7
+
+gossip_getchannels_reply,107
+gossip_getchannels_reply,0,num_channels,u16
+gossip_getchannels_reply,2,nodes,num_channels*struct gossip_getchannels_entry

lightningd/gossip_control.c

@@ -4,6 +4,7 @@
 #include "subd.h"
 #include <ccan/err/err.h>
 #include <ccan/take/take.h>
+#include <ccan/tal/str/str.h>
 #include <daemon/jsonrpc.h>
 #include <daemon/log.h>
 #include <inttypes.h>
@@ -143,10 +144,12 @@ static size_t gossip_msg(struct subd *gossip, const u8 *msg, const int *fds)
 	case WIRE_GOSSIPCTL_RELEASE_PEER:
 	case WIRE_GOSSIP_GETNODES_REQUEST:
 	case WIRE_GOSSIP_GETROUTE_REQUEST:
+	case WIRE_GOSSIP_GETCHANNELS_REQUEST:
 	/* This is a reply, so never gets through to here. */
 	case WIRE_GOSSIPCTL_RELEASE_PEER_REPLY:
 	case WIRE_GOSSIP_GETNODES_REPLY:
 	case WIRE_GOSSIP_GETROUTE_REPLY:
+	case WIRE_GOSSIP_GETCHANNELS_REPLY:
 		break;
 	case WIRE_GOSSIPSTATUS_PEER_BAD_MSG:
 		peer_bad_message(gossip, msg);
@@ -296,3 +299,56 @@ static const struct json_command getroute_command = {
 	"Returns a {route} array of {id} {msatoshi} {delay}: msatoshi and delay (in blocks) is cumulative."
 };
 AUTODATA(json_command, &getroute_command);
+
+/* Called upon receiving a getchannels_reply from `gossipd` */
+static bool json_getchannels_reply(struct subd *gossip, const u8 *reply,
+				   const int *fds, struct command *cmd)
+{
+	size_t i;
+	struct gossip_getchannels_entry *entries;
+	struct json_result *response = new_json_result(cmd);
+	struct short_channel_id *scid;
+
+	if (!fromwire_gossip_getchannels_reply(reply, reply, NULL, &entries)) {
+		command_fail(cmd, "Invalid reply from gossipd");
+		return true;
+	}
+
+	json_object_start(response, NULL);
+	json_array_start(response, "channels");
+	for (i = 0; i < tal_count(entries); i++) {
+		scid = &entries[i].short_channel_id;
+		json_object_start(response, NULL);
+		json_add_pubkey(response, "source", &entries[i].source);
+		json_add_pubkey(response, "destination",
+				&entries[i].destination);
+		json_add_bool(response, "active", entries[i].active);
+		json_add_num(response, "fee_per_kw", entries[i].fee_per_kw);
+		json_add_num(response, "last_update",
+			     entries[i].last_update_timestamp);
+		json_add_num(response, "flags", entries[i].flags);
+		json_add_num(response, "delay", entries[i].delay);
+		json_add_string(response, "short_id",
+				tal_fmt(reply, "%d:%d:%d/%d", scid->blocknum,
+					scid->txnum, scid->outnum,
+					entries[i].flags & 0x1));
+		json_object_end(response);
+	}
+	json_array_end(response);
+	json_object_end(response);
+	command_success(cmd, response);
+	return true;
+}
+
+static void json_getchannels(struct command *cmd, const char *buffer,
+			     const jsmntok_t *params)
+{
+	struct lightningd *ld = ld_from_dstate(cmd->dstate);
+	u8 *req = towire_gossip_getchannels_request(cmd);
+	subd_req(ld->gossip, req, -1, 0, json_getchannels_reply, cmd);
+}
+
+static const struct json_command getchannels_command = {
+    "getchannels", json_getchannels, "List all known channels.",
+    "Returns a 'channels' array with all known channels including their fees."};
+AUTODATA(json_command, &getchannels_command);

lightningd/gossip_msg.c

@@ -39,3 +39,28 @@ void towire_route_hop(u8 **pptr, const struct route_hop *entry)
 	towire_u32(pptr, entry->delay);
 }
 
+void fromwire_gossip_getchannels_entry(const u8 **pptr, size_t *max,
+				      struct gossip_getchannels_entry *entry)
+{
+	fromwire_short_channel_id(pptr, max, &entry->short_channel_id);
+	fromwire_pubkey(pptr, max, &entry->source);
+	fromwire_pubkey(pptr, max, &entry->destination);
+	entry->active = fromwire_bool(pptr, max);
+	entry->fee_per_kw = fromwire_u32(pptr, max);
+	entry->delay = fromwire_u32(pptr, max);
+	entry->last_update_timestamp = fromwire_u32(pptr, max);
+	entry->flags = fromwire_u16(pptr, max);
+}
+
+void towire_gossip_getchannels_entry(
+    u8 **pptr, const struct gossip_getchannels_entry *entry)
+{
+	towire_short_channel_id(pptr, &entry->short_channel_id);
+	towire_pubkey(pptr, &entry->source);
+	towire_pubkey(pptr, &entry->destination);
+	towire_bool(pptr, entry->active);
+	towire_u32(pptr, entry->fee_per_kw);
+	towire_u32(pptr, entry->delay);
+	towire_u32(pptr, entry->last_update_timestamp);
+	towire_u16(pptr, entry->flags);
+}

lightningd/gossip_msg.h

@@ -10,10 +10,28 @@ struct gossip_getnodes_entry {
 	u16 port;
 };
 
-void fromwire_gossip_getnodes_entry(const tal_t *ctx, const u8 **pptr, size_t *max, struct gossip_getnodes_entry *entry);
-void towire_gossip_getnodes_entry(u8 **pptr, const struct gossip_getnodes_entry *entry);
+struct gossip_getchannels_entry {
+	struct pubkey source, destination;
+	u32 fee_per_kw;
+	bool active;
+	struct short_channel_id short_channel_id;
+	u32 last_update_timestamp;
+	u32 delay;
+	u16 flags;
+};
+
+void fromwire_gossip_getnodes_entry(const tal_t *ctx, const u8 **pptr,
+				    size_t *max,
+				    struct gossip_getnodes_entry *entry);
+void towire_gossip_getnodes_entry(u8 **pptr,
+				  const struct gossip_getnodes_entry *entry);
 
 void fromwire_route_hop(const u8 **pprt, size_t *max, struct route_hop *entry);
 void towire_route_hop(u8 **pprt, const struct route_hop *entry);
 
+void fromwire_gossip_getchannels_entry(const u8 **pptr, size_t *max,
+				       struct gossip_getchannels_entry *entry);
+void towire_gossip_getchannels_entry(
+    u8 **pptr, const struct gossip_getchannels_entry *entry);
+
 #endif /* LIGHTNING_LIGHTGNINGD_GOSSIP_MSG_H */