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channel: Disable channels that are lost via a channel_update

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Before exiting, `channeld` constructs and sends a `channel_update`
marking the channel as disabled. This is the pro-active signalling
that the channel may no longer be used.
This commit is contained in:
Christian Decker 2017-03-21 21:21:17 +01:00 committed by Rusty Russell
parent c8da420a9d
commit 60a2227f0d
3 changed files with 44 additions and 25 deletions
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2
daemon/routing.c
View File

@ -750,7 +750,7 @@ void handle_channel_update(struct routing_state *rstate, const u8 *update, size_
c->htlc_minimum_msat = htlc_minimum_msat;
c->base_fee = fee_base_msat;
c->proportional_fee = fee_proportional_millionths;
c->active = true;
c->active = (flags & ROUTING_FLAGS_DISABLED) == 0;
log_debug(rstate->base_log, "Channel %d:%d:%d(%d) was updated.",
short_channel_id.blocknum,
short_channel_id.txnum,

1
daemon/routing.h
View File

@ -7,6 +7,7 @@
#include <ccan/htable/htable_type.h>
#define ROUTING_MAX_HOPS 20
#define ROUTING_FLAGS_DISABLED 2
struct node_connection {
struct node *src, *dst;

66
lightningd/channel/channel.c
View File

@ -97,19 +97,46 @@ static void send_announcement_signatures(struct peer *peer)
tal_free(tmpctx);
}
static void announce_channel(struct peer *peer)
/* The direction bit is 0 if our local node-id is lexicographically
* smaller than the remote node-id. */
static int get_direction_bit(struct peer *peer)
{
tal_t *tmpctx = tal_tmpctx(peer);
u8 local_der[33], remote_der[33];
int first, second;
u32 timestamp = time_now().ts.tv_sec;
u8 *cannounce, *cupdate, *features = tal_arr(peer, u8, 0);
u16 flags;
/* Find out in which order we have to list the endpoints */
pubkey_to_der(local_der, &peer->node_ids[LOCAL]);
pubkey_to_der(remote_der, &peer->node_ids[REMOTE]);
if (memcmp(local_der, remote_der, sizeof(local_der)) < 0) {
return memcmp(local_der, remote_der, sizeof(local_der)) < 0;
}
static void send_channel_update(struct peer *peer, bool disabled)
{
tal_t *tmpctx = tal_tmpctx(peer);
u32 timestamp = time_now().ts.tv_sec;
u16 flags;
u8 *cupdate;
// TODO(cdecker) Create a real signature for this update
secp256k1_ecdsa_signature *sig =
talz(tmpctx, secp256k1_ecdsa_signature);
flags = get_direction_bit(peer) | (disabled << 1);
cupdate = towire_channel_update(
tmpctx, sig, &peer->short_channel_ids[LOCAL], timestamp, flags, 36,
1, 10, peer->channel->view[LOCAL].feerate_per_kw);
daemon_conn_send(&peer->gossip_client, take(cupdate));
msg_enqueue(&peer->peer_out, cupdate);
tal_free(tmpctx);
}
/* Now that we have a working channel, tell the world. */
static void send_channel_announcement(struct peer *peer)
{
tal_t *tmpctx = tal_tmpctx(peer);
int first, second;
u8 *cannounce, *features = tal_arr(peer, u8, 0);
if (get_direction_bit(peer) == 1) {
first = LOCAL;
second = REMOTE;
} else {
@ -117,7 +144,6 @@ static void announce_channel(struct peer *peer)
second = LOCAL;
}
/* Now that we have a working channel, tell the world. */
cannounce = towire_channel_announcement(
tmpctx, &peer->announcement_node_sigs[first],
&peer->announcement_node_sigs[second],
@ -127,21 +153,8 @@ static void announce_channel(struct peer *peer)
&peer->node_ids[second], &peer->funding_pubkey[first],
&peer->funding_pubkey[second], features);
// TODO(cdecker) Create a real signature for this update
secp256k1_ecdsa_signature *sig =
talz(tmpctx, secp256k1_ecdsa_signature);
flags = first == LOCAL;
cupdate = towire_channel_update(
tmpctx, sig, &peer->short_channel_ids[LOCAL], timestamp, flags, 36,
1, 10, peer->channel->view[LOCAL].feerate_per_kw);
msg_enqueue(&peer->peer_out, cannounce);
msg_enqueue(&peer->peer_out, cupdate);
daemon_conn_send(&peer->gossip_client, take(cannounce));
daemon_conn_send(&peer->gossip_client, take(cupdate));
tal_free(tmpctx);
}
@ -192,7 +205,8 @@ static struct io_plan *peer_in(struct io_conn *conn, struct peer *peer, u8 *msg)
sizeof(struct short_channel_id)));
}
if (peer->funding_locked[LOCAL]) {
announce_channel(peer);
send_channel_announcement(peer);
send_channel_update(peer, false);
}
} else if (type == WIRE_CHANNEL_ANNOUNCEMENT ||
type == WIRE_CHANNEL_UPDATE ||
@ -211,6 +225,9 @@ static struct io_plan *setup_peer_conn(struct io_conn *conn, struct peer *peer)
static void peer_conn_broken(struct io_conn *conn, struct peer *peer)
{
send_channel_update(peer, true);
/* Make sure gossipd actually gets this message before dying */
daemon_conn_sync_flush(&peer->gossip_client);
status_failed(WIRE_CHANNEL_PEER_READ_FAILED,
"peer connection broken: %s", strerror(errno));
}
@ -274,7 +291,8 @@ static struct io_plan *req_in(struct io_conn *conn, struct daemon_conn *master)
peer->funding_locked[LOCAL] = true;
if (peer->funding_locked[REMOTE]) {
announce_channel(peer);
send_channel_announcement(peer);
send_channel_update(peer, false);
daemon_conn_send(master,
take(towire_channel_normal_operation(peer)));
}