mirror of
https://github.com/ElementsProject/lightning.git
synced 2025-02-22 14:42:40 +01:00
renepay: add routebuilder.c
Routebuilder constitute the module that builds the routes we try in the payment. The public API is simply `get_routes`, it replaces the similar interface for pay_flows.
This commit is contained in:
Lagrang3
Rusty Russell
parent
6766acbcdf
commit
84651fa4ba
2 changed files with 464 additions and 0 deletions
442
plugins/renepay/routebuilder.c
Normal file
442
plugins/renepay/routebuilder.c
Normal file
|
|
@ -0,0 +1,442 @@
|
|||
#include <ccan/bitmap/bitmap.h>
|
||||
#include <plugins/renepay/mcf.h>
|
||||
#include <plugins/renepay/routebuilder.h>
|
||||
|
||||
static bitmap *make_disabled_bitmap(const tal_t *ctx,
|
||||
const struct gossmap *gossmap,
|
||||
const struct short_channel_id *scids)
|
||||
{
|
||||
bitmap *disabled =
|
||||
tal_arrz(ctx, bitmap, BITMAP_NWORDS(gossmap_max_chan_idx(gossmap)));
|
||||
|
||||
for (size_t i = 0; i < tal_count(scids); i++) {
|
||||
struct gossmap_chan *c = gossmap_find_chan(gossmap, &scids[i]);
|
||||
if (c)
|
||||
bitmap_set_bit(disabled, gossmap_chan_idx(gossmap, c));
|
||||
}
|
||||
return disabled;
|
||||
}
|
||||
|
||||
// static void uncertainty_commit_routes(struct uncertainty *uncertainty,
|
||||
// struct route **routes)
|
||||
// {
|
||||
// const size_t N = tal_count(routes);
|
||||
// for (size_t i = 0; i < N; i++)
|
||||
// uncertainty_commit_htlcs(uncertainty, routes[i]);
|
||||
// }
|
||||
static void uncertainty_remove_routes(struct uncertainty *uncertainty,
|
||||
struct route **routes)
|
||||
{
|
||||
const size_t N = tal_count(routes);
|
||||
for (size_t i = 0; i < N; i++)
|
||||
uncertainty_remove_htlcs(uncertainty, routes[i]);
|
||||
}
|
||||
|
||||
static void mark_chan_disabled(const struct gossmap_chan *chan,
|
||||
struct short_channel_id **disabled_scids,
|
||||
bitmap *disabled_bitmap,
|
||||
struct gossmap *gossmap)
|
||||
{
|
||||
struct short_channel_id scid = gossmap_chan_scid(gossmap, chan);
|
||||
tal_arr_expand(disabled_scids, scid);
|
||||
bitmap_set_bit(disabled_bitmap, gossmap_chan_idx(gossmap, chan));
|
||||
}
|
||||
|
||||
// TODO: check
|
||||
/* Shave-off amounts that do not meet the liquidity constraints. Disable
|
||||
* channels that produce an htlc_max bottleneck. */
|
||||
static struct flow **flows_adjust_htlcmax_constraints(
|
||||
const tal_t *ctx, struct flow **flows TAKES, struct gossmap *gossmap,
|
||||
struct chan_extra_map *chan_extra_map,
|
||||
struct short_channel_id **disabled_scids, bitmap *disabled_bitmap)
|
||||
{
|
||||
struct flow **new_flows = tal_arr(ctx, struct flow *, 0);
|
||||
enum renepay_errorcode errorcode;
|
||||
|
||||
for (size_t i = 0; i < tal_count(flows); i++) {
|
||||
struct flow *f = flows[i];
|
||||
struct amount_msat max_deliverable;
|
||||
const struct gossmap_chan *bad_channel;
|
||||
|
||||
errorcode = flow_maximum_deliverable(
|
||||
&max_deliverable, f, gossmap, chan_extra_map, &bad_channel);
|
||||
|
||||
if (!errorcode) {
|
||||
// no issues
|
||||
f->amount =
|
||||
amount_msat_min(flow_delivers(f), max_deliverable);
|
||||
|
||||
tal_arr_expand(&new_flows, f);
|
||||
} else if (errorcode == RENEPAY_BAD_CHANNEL) {
|
||||
// this is a channel that we can disable
|
||||
mark_chan_disabled(bad_channel, disabled_scids,
|
||||
disabled_bitmap, gossmap);
|
||||
continue;
|
||||
} else {
|
||||
// we had an unexpected error
|
||||
goto function_fail;
|
||||
}
|
||||
}
|
||||
|
||||
for (size_t i = 0; i < tal_count(new_flows); i++) {
|
||||
tal_steal(new_flows, new_flows[i]);
|
||||
}
|
||||
|
||||
if (taken(flows))
|
||||
tal_free(flows);
|
||||
return new_flows;
|
||||
|
||||
function_fail:
|
||||
if (taken(flows))
|
||||
tal_free(flows);
|
||||
return tal_free(new_flows);
|
||||
}
|
||||
|
||||
// TODO: check
|
||||
/* Disable channels that produce an htlc_min bottleneck. */
|
||||
static struct flow **flows_adjust_htlcmin_constraints(
|
||||
const tal_t *ctx, struct flow **flows TAKES, struct gossmap *gossmap,
|
||||
struct chan_extra_map *chan_extra_map,
|
||||
struct short_channel_id **disabled_scids, bitmap *disabled_bitmap)
|
||||
{
|
||||
struct flow **new_flows = tal_arr(ctx, struct flow *, 0);
|
||||
enum renepay_errorcode errorcode;
|
||||
struct amount_msat max_deliverable;
|
||||
|
||||
for (size_t i = 0; i < tal_count(flows); i++) {
|
||||
struct flow *f = flows[i];
|
||||
const struct gossmap_chan *bad_channel;
|
||||
|
||||
errorcode = flow_maximum_deliverable(
|
||||
&max_deliverable, f, gossmap, chan_extra_map, &bad_channel);
|
||||
|
||||
if (!errorcode) {
|
||||
// no issues
|
||||
f->amount =
|
||||
amount_msat_min(flow_delivers(f), max_deliverable);
|
||||
|
||||
tal_arr_expand(&new_flows, f);
|
||||
} else if (errorcode == RENEPAY_BAD_CHANNEL) {
|
||||
// this is a channel that we can disable
|
||||
mark_chan_disabled(bad_channel, disabled_scids,
|
||||
disabled_bitmap, gossmap);
|
||||
continue;
|
||||
} else {
|
||||
// we had an unexpected error
|
||||
goto function_fail;
|
||||
}
|
||||
}
|
||||
|
||||
for (size_t i = 0; i < tal_count(new_flows); i++) {
|
||||
tal_steal(new_flows, new_flows[i]);
|
||||
}
|
||||
|
||||
if (taken(flows))
|
||||
tal_free(flows);
|
||||
return new_flows;
|
||||
|
||||
function_fail:
|
||||
if (taken(flows))
|
||||
tal_free(flows);
|
||||
return tal_free(new_flows);
|
||||
}
|
||||
|
||||
/* Routes are computed and saved in the payment for later use. */
|
||||
struct route **get_routes(const tal_t *ctx, struct payment *payment,
|
||||
|
||||
const struct node_id *source,
|
||||
const struct node_id *destination,
|
||||
struct gossmap *gossmap, struct uncertainty *uncertainty,
|
||||
|
||||
struct amount_msat amount_to_deliver,
|
||||
const u32 final_cltv, struct amount_msat feebudget,
|
||||
|
||||
enum jsonrpc_errcode *ecode, const char **fail)
|
||||
{
|
||||
assert(gossmap);
|
||||
assert(uncertainty);
|
||||
|
||||
const tal_t *this_ctx = tal(ctx, tal_t);
|
||||
struct route **routes = tal_arr(ctx, struct route *, 0);
|
||||
|
||||
double probability_budget = payment->min_prob_success;
|
||||
double delay_feefactor = payment->delay_feefactor;
|
||||
const double base_fee_penalty = payment->base_fee_penalty;
|
||||
const double prob_cost_factor = payment->prob_cost_factor;
|
||||
const unsigned int maxdelay = payment->maxdelay;
|
||||
|
||||
bitmap *disabled_bitmap =
|
||||
make_disabled_bitmap(this_ctx, gossmap, payment->disabled_scids);
|
||||
|
||||
const struct gossmap_node *src, *dst;
|
||||
src = gossmap_find_node(gossmap, source);
|
||||
if (!src) {
|
||||
if (ecode)
|
||||
*ecode = PAY_ROUTE_NOT_FOUND;
|
||||
if (fail)
|
||||
*fail = tal_fmt(ctx, "We don't have any channels.");
|
||||
goto function_fail;
|
||||
}
|
||||
dst = gossmap_find_node(gossmap, destination);
|
||||
if (!dst) {
|
||||
if (ecode)
|
||||
*ecode = PAY_ROUTE_NOT_FOUND;
|
||||
if (fail)
|
||||
*fail = tal_fmt(
|
||||
ctx,
|
||||
"Destination is unknown in the network gossip.");
|
||||
goto function_fail;
|
||||
}
|
||||
|
||||
char *errmsg;
|
||||
|
||||
while (!amount_msat_zero(amount_to_deliver)) {
|
||||
|
||||
/* TODO: choose an algorithm, could be something like
|
||||
* payment->algorithm, that we set up based on command line
|
||||
* options and that can be changed according to some conditions
|
||||
* met during the payment process, eg. add "select_solver" pay
|
||||
* mod. */
|
||||
/* TODO: use uncertainty instead of chan_extra */
|
||||
/* TODO: shall we add to possibility to blacklist nodes? */
|
||||
|
||||
/* Min. Cost Flow algorithm to find optimal flows. */
|
||||
struct flow **flows =
|
||||
minflow(this_ctx, gossmap, src, dst,
|
||||
uncertainty_get_chan_extra_map(uncertainty),
|
||||
disabled_bitmap, amount_to_deliver, feebudget,
|
||||
probability_budget, delay_feefactor,
|
||||
base_fee_penalty, prob_cost_factor, &errmsg);
|
||||
|
||||
if (!flows) {
|
||||
if (ecode)
|
||||
*ecode = PAY_ROUTE_NOT_FOUND;
|
||||
|
||||
if (fail)
|
||||
*fail = tal_fmt(
|
||||
ctx,
|
||||
"minflow couldn't find a feasible flow: %s",
|
||||
errmsg);
|
||||
goto function_fail;
|
||||
}
|
||||
|
||||
/* In previous implementations we would search for
|
||||
* htlcmax/htlcmin violations and disable those channels and
|
||||
* then redo the MCF computation. Now we instead remove only
|
||||
* those flows for which there is a constraint violation and
|
||||
* mark the involved channels as disabled for the next MCF
|
||||
* iteration. */
|
||||
flows = flows_adjust_htlcmax_constraints(
|
||||
this_ctx, take(flows), gossmap,
|
||||
uncertainty_get_chan_extra_map(uncertainty),
|
||||
&payment->disabled_scids, disabled_bitmap);
|
||||
if (!flows) {
|
||||
if (ecode)
|
||||
*ecode = PAY_ROUTE_NOT_FOUND;
|
||||
|
||||
if (fail)
|
||||
*fail = tal_fmt(
|
||||
ctx,
|
||||
"failed to adjust htlcmax constraints.");
|
||||
|
||||
goto function_fail;
|
||||
}
|
||||
|
||||
flows = flows_adjust_htlcmin_constraints(
|
||||
this_ctx, take(flows), gossmap,
|
||||
uncertainty_get_chan_extra_map(uncertainty),
|
||||
&payment->disabled_scids, disabled_bitmap);
|
||||
if (!flows) {
|
||||
if (ecode)
|
||||
*ecode = PAY_ROUTE_NOT_FOUND;
|
||||
|
||||
if (fail)
|
||||
*fail = tal_fmt(
|
||||
ctx,
|
||||
"failed to adjust htlcmin constraints.");
|
||||
|
||||
goto function_fail;
|
||||
}
|
||||
// TODO: check issue #7136
|
||||
|
||||
/* Check the fee limits. */
|
||||
/* TODO: review this, only flows with non-zero amount */
|
||||
struct amount_msat fee;
|
||||
if (!flowset_fee(&fee, flows)) {
|
||||
if (ecode)
|
||||
*ecode = PLUGIN_ERROR;
|
||||
|
||||
if (fail)
|
||||
*fail = tal_fmt(ctx, "flowset_fee failed");
|
||||
goto function_fail;
|
||||
}
|
||||
if (amount_msat_greater(fee, feebudget)) {
|
||||
if (ecode)
|
||||
*ecode = PAY_ROUTE_TOO_EXPENSIVE;
|
||||
|
||||
if (fail)
|
||||
*fail = tal_fmt(
|
||||
ctx,
|
||||
"Fee exceeds our fee budget, fee=%s "
|
||||
"(feebudget=%s)",
|
||||
fmt_amount_msat(this_ctx, fee),
|
||||
fmt_amount_msat(this_ctx, feebudget));
|
||||
goto function_fail;
|
||||
}
|
||||
|
||||
/* Check the CLTV delay */
|
||||
/* TODO: review this, only flows with non-zero amounts */
|
||||
const u64 delay = flows_worst_delay(flows) + final_cltv;
|
||||
if (delay > maxdelay) {
|
||||
/* FIXME: What is a sane limit? */
|
||||
if (delay_feefactor > 1000) {
|
||||
if (ecode)
|
||||
*ecode = PAY_ROUTE_TOO_EXPENSIVE;
|
||||
if (fail)
|
||||
*fail = tal_fmt(
|
||||
ctx,
|
||||
"CLTV delay exceeds our CLTV "
|
||||
"budget, delay=%" PRIu64
|
||||
"(maxdelay=%u)",
|
||||
delay, maxdelay);
|
||||
goto function_fail;
|
||||
}
|
||||
|
||||
delay_feefactor *= 2;
|
||||
continue; // retry
|
||||
}
|
||||
|
||||
/* Compute the flows probability */
|
||||
/* TODO: review this, only flows with non-zero amounts */
|
||||
double prob = flowset_probability(
|
||||
this_ctx, flows, gossmap,
|
||||
uncertainty_get_chan_extra_map(uncertainty), NULL);
|
||||
if (prob < 0) {
|
||||
if (ecode)
|
||||
*ecode = PLUGIN_ERROR;
|
||||
if (fail)
|
||||
*fail =
|
||||
tal_fmt(ctx, "flowset_probability failed");
|
||||
goto function_fail;
|
||||
}
|
||||
|
||||
struct amount_msat delivering;
|
||||
if (!flowset_delivers(&delivering, flows)) {
|
||||
if (ecode)
|
||||
*ecode = PLUGIN_ERROR;
|
||||
|
||||
if (fail)
|
||||
*fail = tal_fmt(ctx, "flowset_delivers failed");
|
||||
goto function_fail;
|
||||
}
|
||||
|
||||
/* OK, we are happy with these flows: convert to
|
||||
* routes in the current payment. */
|
||||
delivering = AMOUNT_MSAT(0);
|
||||
fee = AMOUNT_MSAT(0);
|
||||
// TODO check ownership of these routes
|
||||
for (size_t i = 0; i < tal_count(flows); i++) {
|
||||
struct route *r = flow_to_route(
|
||||
ctx, payment, payment->groupid,
|
||||
payment->next_partid, payment->payment_hash,
|
||||
final_cltv, gossmap, flows[i]);
|
||||
if (!r) {
|
||||
/* TODO: what could have gone wrong? */
|
||||
continue;
|
||||
}
|
||||
payment->next_partid++;
|
||||
uncertainty_commit_htlcs(uncertainty, r);
|
||||
tal_arr_expand(&routes, r);
|
||||
|
||||
struct amount_msat route_fee = route_fees(r),
|
||||
route_deliver = route_delivers(r);
|
||||
|
||||
if (!amount_msat_add(&fee, fee, route_fee) ||
|
||||
!amount_msat_add(&delivering, delivering,
|
||||
route_deliver)) {
|
||||
if (ecode)
|
||||
*ecode = PLUGIN_ERROR;
|
||||
|
||||
if (fail)
|
||||
*fail = tal_fmt(
|
||||
ctx,
|
||||
"%s (line %d) amount_msat "
|
||||
"arithmetic overflow.",
|
||||
__PRETTY_FUNCTION__, __LINE__);
|
||||
goto function_fail;
|
||||
}
|
||||
}
|
||||
|
||||
/* For the next iteration get me the amount_to_deliver */
|
||||
if (!amount_msat_sub(&amount_to_deliver, amount_to_deliver,
|
||||
delivering)) {
|
||||
/* In the next iteration we search routes that allocate
|
||||
*amount_to_deliver - delivering If we have delivering >
|
||||
*amount_to_deliver it means we have made a mistake
|
||||
*somewhere.
|
||||
*/
|
||||
if (ecode)
|
||||
*ecode = PLUGIN_ERROR;
|
||||
|
||||
if (fail)
|
||||
*fail = tal_fmt(
|
||||
ctx,
|
||||
"%s (line %d) delivering to destination "
|
||||
"(%s) is more than requested (%s)",
|
||||
__PRETTY_FUNCTION__, __LINE__,
|
||||
fmt_amount_msat(this_ctx, delivering),
|
||||
fmt_amount_msat(this_ctx,
|
||||
amount_to_deliver));
|
||||
goto function_fail;
|
||||
}
|
||||
|
||||
/* For the next iteration get me the feebudget */
|
||||
if (!amount_msat_sub(&feebudget, feebudget, fee)) {
|
||||
if (ecode)
|
||||
*ecode = PLUGIN_ERROR;
|
||||
|
||||
if (fail)
|
||||
*fail = tal_fmt(
|
||||
ctx,
|
||||
"%s (line %d) routing fees (%s) exceed fee "
|
||||
"budget (%s).",
|
||||
__PRETTY_FUNCTION__, __LINE__,
|
||||
fmt_amount_msat(this_ctx, fee),
|
||||
fmt_amount_msat(this_ctx, feebudget));
|
||||
goto function_fail;
|
||||
}
|
||||
|
||||
/* For the next iteration get me the probability_budget */
|
||||
if (prob < 1e-10) {
|
||||
/* this last flow probability is too small for division
|
||||
*/
|
||||
probability_budget = 1.0;
|
||||
} else {
|
||||
/* prob here is a conditional probability, the next
|
||||
* round of flows will have a conditional probability
|
||||
* prob2 and we would like that prob*prob2 >=
|
||||
* probability_budget hence probability_budget/prob
|
||||
* becomes the next iteration's target. */
|
||||
probability_budget =
|
||||
MIN(1.0, probability_budget / prob);
|
||||
}
|
||||
}
|
||||
|
||||
/* remove the temporary routes from the uncertainty network */
|
||||
uncertainty_remove_routes(uncertainty, routes);
|
||||
|
||||
/* ownership */
|
||||
for (size_t i = 0; i < tal_count(routes); i++)
|
||||
routes[i] = tal_steal(routes, routes[i]);
|
||||
|
||||
tal_free(this_ctx);
|
||||
return routes;
|
||||
|
||||
function_fail:
|
||||
/* remove the temporary routes from the uncertainty network */
|
||||
uncertainty_remove_routes(uncertainty, routes);
|
||||
|
||||
/* Discard any routes we have constructed here. */
|
||||
tal_free(this_ctx);
|
||||
return tal_free(routes);
|
||||
}
|
||||
22
plugins/renepay/routebuilder.h
Normal file
22
plugins/renepay/routebuilder.h
Normal file
|
|
@ -0,0 +1,22 @@
|
|||
#ifndef LIGHTNING_PLUGINS_RENEPAY_ROUTEBUILDER_H
|
||||
#define LIGHTNING_PLUGINS_RENEPAY_ROUTEBUILDER_H
|
||||
|
||||
#include "config.h"
|
||||
#include <ccan/tal/tal.h>
|
||||
#include <common/gossmap.h>
|
||||
#include <plugins/renepay/payment.h>
|
||||
#include <plugins/renepay/route.h>
|
||||
#include <plugins/renepay/uncertainty.h>
|
||||
|
||||
struct route **get_routes(const tal_t *ctx, struct payment *payment,
|
||||
|
||||
const struct node_id *source,
|
||||
const struct node_id *destination,
|
||||
struct gossmap *gossmap, struct uncertainty *uncertainty,
|
||||
|
||||
struct amount_msat amount_to_deliver,
|
||||
const u32 final_cltv, struct amount_msat feebudget,
|
||||
|
||||
enum jsonrpc_errcode *ecode, const char **fail);
|
||||
|
||||
#endif /* LIGHTNING_PLUGINS_RENEPAY_ROUTEBUILDER_H */
|
||||
Loading…
Add table
Reference in a new issue