mirrors/core-lightning
1
0
Fork 0
mirror of https://github.com/ElementsProject/lightning.git synced 2024-11-19 18:11:28 +01:00
Code Issues Projects Releases Wiki Activity

routing: Fix the announcement detection for channel_announcements

Browse Source 
If we side-load a channel, using local-add or the removed JSON-RPC
call, then we could end up in a situation in which a channel is
present, but has no associated channel_announcement. The presence of
the channel_announcement was used to identify new channels, so this
could lead to channels always being considered new. This then caused
the announcements being added to the queue always, resulting in
channel_updates preceeding the announcement.

Signed-off-by: Christian Decker <decker.christian@gmail.com>
This commit is contained in:
Christian Decker 2017-12-21 10:53:37 +01:00
parent 83caf1fdab
commit 0db821e2cf
1 changed files with 46 additions and 42 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

88
gossipd/routing.c
View File

@ -426,25 +426,32 @@ find_route(const tal_t *ctx, struct routing_state *rstate,
return first_conn;
}
static bool add_channel_direction(struct routing_state *rstate,
const struct pubkey *from,
const struct pubkey *to,
const struct short_channel_id *short_channel_id,
const u8 *announcement)
static struct node_connection *
add_channel_direction(struct routing_state *rstate, const struct pubkey *from,
const struct pubkey *to,
const struct short_channel_id *short_channel_id,
const u8 *announcement)
{
struct node_connection *c = get_connection(rstate, from, to);
struct node_connection *c1, *c2, *c;
u16 direction = get_channel_direction(from, to);
if (c){
/* Do not clobber connections added otherwise */
memcpy(&c->short_channel_id, short_channel_id,
sizeof(c->short_channel_id));
c->flags = direction;
return false;
}else if(get_connection_by_scid(rstate, short_channel_id, direction)) {
return false;
}
c = half_add_connection(rstate, from, to, short_channel_id, direction);
c1 = get_connection(rstate, from, to);
c2 = get_connection_by_scid(rstate, short_channel_id, direction);
if(c2) {
/* We already know the channel by its scid, just
* update the announcement below */
c = c2;
} else if (c2) {
/* We found the channel by its endpoints, not by scid,
* so update its scid */
memcpy(&c1->short_channel_id, short_channel_id,
sizeof(c->short_channel_id));
c1->flags = direction;
c = c1;
} else {
/* We don't know this channel at all, create it */
c = half_add_connection(rstate, from, to, short_channel_id, direction);
}
/* Remember the announcement so we can forward it to new peers */
if (announcement) {
@ -452,7 +459,8 @@ static bool add_channel_direction(struct routing_state *rstate,
c->channel_announcement = tal_dup_arr(c, u8, announcement,
tal_count(announcement), 0);
}
return true;
return c;
}
/* Verify the signature of a channel_update message */
@ -507,6 +515,7 @@ bool handle_channel_announcement(
struct node_connection *c0, *c1;
const tal_t *tmpctx = tal_tmpctx(rstate);
u8 *features;
char *tag;
size_t len = tal_len(announce);
serialized = tal_dup_arr(tmpctx, u8, announce, len, 0);
@ -523,16 +532,19 @@ bool handle_channel_announcement(
return false;
}
tag = type_to_string(tmpctx, struct short_channel_id,
&short_channel_id);
/* BOLT #7:
*
* The receiving node MUST ignore the message if the specified
* `chain_hash` is unknown to the receiver.
*/
if (!structeq(&chain_hash, &rstate->chain_hash)) {
status_trace("Received channel_announcement for unknown chain"
" %s",
type_to_string(tmpctx, struct bitcoin_blkid,
&chain_hash));
status_trace(
"Received channel_announcement %s for unknown chain %s",
tag,
type_to_string(tmpctx, struct bitcoin_blkid, &chain_hash));
tal_free(tmpctx);
return false;
}
@ -540,51 +552,43 @@ bool handle_channel_announcement(
// FIXME: Check features!
//FIXME(cdecker) Check chain topology for the anchor TX
local = pubkey_eq(&node_id_1, &rstate->local_id) ||
pubkey_eq(&node_id_2, &rstate->local_id);
sigfail = !check_channel_announcement(
&node_id_1, &node_id_2, &bitcoin_key_1, &bitcoin_key_2,
&node_signature_1, &node_signature_2, &bitcoin_signature_1,
&bitcoin_signature_2, serialized);
status_trace("Received channel_announcement for channel %s, local=%d, sigfail=%d",
type_to_string(trc, struct short_channel_id,
&short_channel_id), local, sigfail);
tag, local, sigfail);
if (sigfail && !local) {
if (sigfail) {
status_trace(
"Signature verification of non-local channel announcement failed");
"Signature verification of channel_announcement for %s failed", tag);
tal_free(tmpctx);
return false;
}
/* Is this a new connection? */
/* Is this a new connection? It is if we don't know the
* channel yet, or do not have a matching announcement in the
* case of side-loaded channels*/
c0 = get_connection_by_scid(rstate, &short_channel_id, 0);
c1 = get_connection_by_scid(rstate, &short_channel_id, 1);
forward = !c0 || !c1 || !c0->channel_announcement || !c1->channel_announcement;
add_channel_direction(rstate, &node_id_1, &node_id_2, &short_channel_id,
sigfail ? NULL : serialized);
serialized);
add_channel_direction(rstate, &node_id_2, &node_id_1, &short_channel_id,
sigfail ? NULL : serialized);
serialized);
if (!forward || sigfail) {
status_trace("Not forwarding channel_announcement, forward=%d, sigfail=%d", forward, sigfail);
tal_free(tmpctx);
/* This will not be forwarded so we do not want to
* announce the node either, others might drop it. */
return false;
if (forward) {
assert(!queue_broadcast(rstate->broadcasts, WIRE_CHANNEL_ANNOUNCEMENT,
(u8*)tag, serialized));
}
u8 *tag = tal_arr(tmpctx, u8, 0);
towire_short_channel_id(&tag, &short_channel_id);
assert(!queue_broadcast(rstate->broadcasts, WIRE_CHANNEL_ANNOUNCEMENT,
tag, serialized));
tal_free(tmpctx);
return local;
return local && forward;
}
void handle_channel_update(struct routing_state *rstate, const u8 *update)