Skip to content

renepay: handle it if channel_capacity unavailable. #7194

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
rustyrussell wants to merge 1 commit into from
Closed

renepay: handle it if channel_capacity unavailable. #7194

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
26 changes: 20 additions & 6 deletions plugins/renepay/uncertainty_network.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -170,15 +170,29 @@ void uncertainty_network_update(

if(!gossmap_chan_get_capacity(gossmap,chan,&cap))
{
plugin_err(pay_plugin->plugin,"%s (line %d) unable to fetch channel capacity",
__PRETTY_FUNCTION__,
__LINE__);
/* This can happen transiently if gossipd is
* writing it to the store right now. Set
* it to larger htlc_max */
cap_msat = AMOUNT_MSAT(0);
for (int dir = 0; dir < 2; dir++)
{
struct amount_msat htlc_max;
if (!gossmap_chan_set(chan, dir))
continue;
htlc_max = amount_msat(fp16_to_u64(chan->half[dir].htlc_max));
if (amount_msat_greater(htlc_max, cap_msat))
cap_msat = htlc_max;
}
plugin_log(pay_plugin->plugin, LOG_UNUSUAL,
"Cannot fetch capacity for channel %s: using %s",
fmt_short_channel_id(tmpctx, scid),
fmt_amount_msat(tmpctx, cap_msat));
Comment on lines +173 to +189

@Lagrang3 Lagrang3 Apr 3, 2024

Copy link
Copy Markdown
Collaborator

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

An easier solution would be to ignore those channels temporarily, they can still be picked up next time uncertainty_network_update is called again.

Suggested change
/* This can happen transiently if gossipd is
* writing it to the store right now. Set
* it to larger htlc_max */
cap_msat = AMOUNT_MSAT(0);
for (int dir = 0; dir < 2; dir++)
{
struct amount_msat htlc_max;
if (!gossmap_chan_set(chan, dir))
continue;
htlc_max = amount_msat(fp16_to_u64(chan->half[dir].htlc_max));
if (amount_msat_greater(htlc_max, cap_msat))
cap_msat = htlc_max;
}
plugin_log(pay_plugin->plugin, LOG_UNUSUAL,
"Cannot fetch capacity for channel %s: using %s",
fmt_short_channel_id(tmpctx, scid),
fmt_amount_msat(tmpctx, cap_msat));
/* This can happen transiently if gossipd is
* writing it to the store right now.
* Ignore this channel for the moment, we can
* pick it up next time. */
plugin_log(pay_plugin->plugin, LOG_UNUSUAL,
"Cannot fetch capacity for channel %s: skipping it.",
fmt_short_channel_id(tmpctx, scid));

The only issue I can think of right now, is that we will have some channels in gossmap that have no counterpart in chan_extra_map and we would have to handle this case when the MCF graph is built (init_linear_network in mcf.c assumes that).

}
if(!amount_sat_to_msat(&cap_msat,cap))
else if(!amount_sat_to_msat(&cap_msat,cap))
{
plugin_err(pay_plugin->plugin,"%s (line %d) unable convert sat to msat",
__PRETTY_FUNCTION__,
__LINE__);
__PRETTY_FUNCTION__,
__LINE__);
}
new_chan_extra(chan_extra_map,scid,cap_msat);
}
Expand Down