mirrors/core-lightning
1
0
Fork 0
mirror of https://github.com/ElementsProject/lightning.git synced 2025-03-12 10:30:29 +01:00
Code Issues Projects Releases Wiki Activity

pay: Add a pre-flight check for the spendable balance

Browse source 
Changelog-Added: pay: The pay plugin now checks whether we have enough spendable capacity before computing a route, returning a clear error message if we don't
This commit is contained in:
Christian Decker 2024-06-19 17:49:08 +02:00 • committed by ShahanaFarooqui
parent c2a698069e
commit 82afa8d38c
4 changed files with 119 additions and 9 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

3
common/jsonrpc_errors.h
View file

@ -48,6 +48,9 @@ enum jsonrpc_errcode {
PAY_INVOICE_REQUEST_INVALID = 212,
PAY_INVOICE_PREAPPROVAL_DECLINED = 213,
PAY_KEYSEND_PREAPPROVAL_DECLINED = 214,
PAY_INSUFFICIENT_FUNDS = 215,
PAY_UNREACHABLE = 216,
PAY_USER_ERROR = 217,
/* `fundchannel` or `withdraw` errors */
FUND_MAX_EXCEEDED = 300,

107
plugins/libplugin-pay.c
View file

@ -1002,16 +1002,105 @@ static struct command_result *payment_getroute(struct payment *p)
return command_still_pending(p->cmd);
}
static struct command_result *
payment_listpeerchannels_success(struct command *cmd,
const char *buffer,
const jsmntok_t *toks,
struct payment *p)
/**
* Compute the total sum of balances. Limits the maximum size we can
* pay as a preflight test. Returns `false` on errors, otherwise
* `sum` contains the sum of all channel balances.*/
static bool payment_listpeerchannels_balance_sum(struct payment *p,
const char *buf,
const jsmntok_t *toks,
struct amount_msat *sum)
{
p->mods = gossmods_from_listpeerchannels(p, p->local_id,
buffer, toks, true,
gossmod_add_localchan,
NULL);
*sum = AMOUNT_MSAT(0);
const jsmntok_t *channels, *channel;
struct amount_msat spendable;
bool connected;
size_t i;
const char *err;
channels = json_get_member(buf, toks, "channels");
json_for_each_arr(i, channel, channels)
{
err = json_scan(tmpctx, buf, channel,
"{spendable_msat?:%,peer_connected:%}",
JSON_SCAN(json_to_msat, &spendable),
JSON_SCAN(json_to_bool, &connected));
if (err) {
paymod_log(p, LOG_UNUSUAL,
"Bad listpeerchannels.channels %zu: %s", i,
err);
return false;
}
if (!amount_msat_add(sum, *sum, spendable)) {
paymod_log(
p, LOG_BROKEN,
"Integer sum overflow summing spendable amounts.");
return false;
}
}
return true;
}
static struct command_result *
payment_listpeerchannels_success(struct command *cmd, const char *buffer,
const jsmntok_t *toks, struct payment *p)
{
/* The maximum amount we may end up trying to send. This
* includes the value and the full fee budget. If the
* available funds are below this, we emit a warning. */
struct amount_msat maxrequired, spendable;
if (!amount_msat_add(&maxrequired, p->getroute->amount,
p->constraints.fee_budget)) {
paymod_log(p, LOG_BROKEN,
"amount_msat overflow computing the fee budget");
return payment_getroute(p);
}
p->mods = gossmods_from_listpeerchannels(
p, p->local_id, buffer, toks, true, gossmod_add_localchan, NULL);
if (!payment_listpeerchannels_balance_sum(p, buffer, toks,
&spendable)) {
paymod_log(p, LOG_UNUSUAL,
"Unable to get total spendable amount from "
"listpeerchannels. Skipping affordability check.");
/* Keep your fingers crossed, we may still succeed. */
return payment_getroute(p);
}
/* Pre-flight check: can we even afford the full amount of the
* payment? And if yes, can we afford the full amount with the
* full fee budget? If the former fails, we fail immediately,
* for the latter we log a warning, so we can root-cause this
* a bit better if we then run into routing issues. */
if (amount_msat_greater(p->getroute->amount, spendable)) {
paymod_log(p, LOG_UNUSUAL,
"Insufficient funds to perform the payment: "
"spendable=%s < payment=%s",
fmt_amount_msat(tmpctx, spendable),
fmt_amount_msat(tmpctx, p->getroute->amount));
payment_abort(p, PAY_INSUFFICIENT_FUNDS,
"Insufficient funds to perform the payment: "
"spendable=%s < payment=%s",
fmt_amount_msat(tmpctx, spendable),
fmt_amount_msat(tmpctx, p->getroute->amount));
return command_still_pending(p->cmd);
} else if (amount_msat_greater(maxrequired, spendable)) {
char *msg = tal_fmt(
tmpctx,
"We do not have sufficient funds to pay for the specified "
"fee budget: spendable=%s < payment=%s + budget=%s. This "
"may cause a failed payment, but we'll try anyway.",
fmt_amount_msat(tmpctx, spendable),
fmt_amount_msat(tmpctx, p->getroute->amount),
fmt_amount_msat(tmpctx, p->constraints.fee_budget));
plugin_notify_message(p->cmd, LOG_INFORM, "%s", msg);
}
return payment_getroute(p);
}

9
plugins/test/run-route-calc.c
View file

@ -165,6 +165,9 @@ const char *json_scan(const tal_t *ctx UNNEEDED,
/* Generated stub for json_strdup */
char *json_strdup(const tal_t *ctx UNNEEDED, const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED)
{ fprintf(stderr, "json_strdup called!\n"); abort(); }
/* Generated stub for json_to_bool */
bool json_to_bool(const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED, bool *b UNNEEDED)
{ fprintf(stderr, "json_to_bool called!\n"); abort(); }
/* Generated stub for json_to_createonion_response */
struct createonion_response *json_to_createonion_response(const tal_t *ctx UNNEEDED,
const char *buffer UNNEEDED,
@ -264,6 +267,12 @@ void plugin_notification_end(struct plugin *plugin UNNEEDED,
struct json_stream *plugin_notification_start(struct plugin *plugins UNNEEDED,
const char *method UNNEEDED)
{ fprintf(stderr, "plugin_notification_start called!\n"); abort(); }
/* Generated stub for plugin_notify_message */
void plugin_notify_message(struct command *cmd UNNEEDED,
enum log_level level UNNEEDED,
const char *fmt UNNEEDED, ...)
{ fprintf(stderr, "plugin_notify_message called!\n"); abort(); }
/* Generated stub for random_select */
bool random_select(double weight UNNEEDED, double *tot_weight UNNEEDED)
{ fprintf(stderr, "random_select called!\n"); abort(); }

9
plugins/test/run-route-overlong.c
View file

@ -162,6 +162,9 @@ const char *json_scan(const tal_t *ctx UNNEEDED,
/* Generated stub for json_strdup */
char *json_strdup(const tal_t *ctx UNNEEDED, const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED)
{ fprintf(stderr, "json_strdup called!\n"); abort(); }
/* Generated stub for json_to_bool */
bool json_to_bool(const char *buffer UNNEEDED, const jsmntok_t *tok UNNEEDED, bool *b UNNEEDED)
{ fprintf(stderr, "json_to_bool called!\n"); abort(); }
/* Generated stub for json_to_createonion_response */
struct createonion_response *json_to_createonion_response(const tal_t *ctx UNNEEDED,
const char *buffer UNNEEDED,
@ -261,6 +264,12 @@ void plugin_notification_end(struct plugin *plugin UNNEEDED,
struct json_stream *plugin_notification_start(struct plugin *plugins UNNEEDED,
const char *method UNNEEDED)
{ fprintf(stderr, "plugin_notification_start called!\n"); abort(); }
/* Generated stub for plugin_notify_message */
void plugin_notify_message(struct command *cmd UNNEEDED,
enum log_level level UNNEEDED,
const char *fmt UNNEEDED, ...)
{ fprintf(stderr, "plugin_notify_message called!\n"); abort(); }
/* Generated stub for random_select */
bool random_select(double weight UNNEEDED, double *tot_weight UNNEEDED)
{ fprintf(stderr, "random_select called!\n"); abort(); }