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rgb-cln/plugins/libplugin-pay.c

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#include "config.h"
#include <ccan/array_size/array_size.h>
#include <ccan/tal/str/str.h>
#include <common/blindedpay.h>
#include <common/dijkstra.h>
#include <common/gossmap.h>
#include <common/json_stream.h>
#include <common/memleak.h>
#include <common/pseudorand.h>
#include <common/random_select.h>
#include <common/type_to_string.h>
#include <errno.h>
#include <math.h>
#include <plugins/libplugin-pay.h>
#include <sys/types.h>
#include <wire/peer_wire.h>
static struct gossmap *global_gossmap;
static void init_gossmap(struct plugin *plugin)
{
size_t num_channel_updates_rejected;
global_gossmap
= notleak_with_children(gossmap_load(NULL,
GOSSIP_STORE_FILENAME,
&num_channel_updates_rejected));
if (!global_gossmap)
plugin_err(plugin, "Could not load gossmap %s: %s",
GOSSIP_STORE_FILENAME, strerror(errno));
if (num_channel_updates_rejected)
plugin_log(plugin, LOG_DBG,
"gossmap ignored %zu channel updates",
num_channel_updates_rejected);
}
struct gossmap *get_gossmap(struct plugin *plugin)
{
if (!global_gossmap)
init_gossmap(plugin);
else
gossmap_refresh(global_gossmap, NULL);
return global_gossmap;
}
struct payment *payment_new(tal_t *ctx, struct command *cmd,
struct payment *parent,
struct payment_modifier **mods)
{
struct payment *p = tal(ctx, struct payment);
static u64 next_id = 0;
p->children = tal_arr(p, struct payment *, 0);
p->parent = parent;
p->modifiers = mods;
p->cmd = cmd;
p->start_time = time_now();
p->result = NULL;
p->why = NULL;
p->getroute = tal(p, struct getroute_request);
p->label = NULL;
p->failreason = NULL;
p->getroute->riskfactorppm = 10000000;
p->abort = false;
p->invstring_used = false;
p->route = NULL;
p->temp_exclusion = NULL;
p->failroute_retry = false;
p->routetxt = NULL;
p->max_htlcs = UINT32_MAX;
p->aborterror = NULL;
p->on_payment_success = NULL;
p->on_payment_failure = NULL;
/* Copy over the relevant pieces of information. */
if (parent != NULL) {
assert(cmd == NULL);
tal_arr_expand(&parent->children, p);
p->destination = parent->destination;
p->amount = parent->amount;
p->label = parent->label;
p->payment_hash = parent->payment_hash;
p->partid = payment_root(p->parent)->next_partid++;
p->plugin = parent->plugin;
/* Re-establish the unmodified constraints for our sub-payment. */
p->constraints = *parent->start_constraints;
p->deadline = parent->deadline;
p->min_final_cltv_expiry = parent->min_final_cltv_expiry;
p->routes = parent->routes;
p->features = parent->features;
p->id = parent->id;
p->local_id = parent->local_id;
p->local_invreq_id = parent->local_invreq_id;
p->groupid = parent->groupid;
p->invstring = parent->invstring;
p->description = parent->description;
} else {
assert(cmd != NULL);
p->partid = 0;
p->next_partid = 1;
p->plugin = cmd->plugin;
p->channel_hints = tal_arr(p, struct channel_hint, 0);
p->excluded_nodes = tal_arr(p, struct node_id, 0);
p->id = next_id++;
p->description = NULL;
/* Caller must set this. */
p->local_id = NULL;
p->local_invreq_id = NULL;
p->groupid = 0;
}
/* Initialize all modifier data so we can point to the fields when
* wiring into the param() call in a JSON-RPC handler. The callback
* can also just `memcpy` the parent if this outside access is not
* required. */
p->modifier_data = tal_arr(p, void *, 0);
for (size_t i=0; mods[i] != NULL; i++) {
if (mods[i]->data_init != NULL)
tal_arr_expand(&p->modifier_data,
mods[i]->data_init(p));
else
tal_arr_expand(&p->modifier_data, NULL);
}
return p;
}
struct payment *payment_root(struct payment *p)
{
if (p->parent == NULL)
return p;
else
return payment_root(p->parent);
}
static void
paymod_log_header(struct payment *p, const char **type, u64 *id)
{
struct payment *root = payment_root(p);
/* We prefer to show the command ID here since it is also known
* by `lightningd`, so in theory it can be used to correlate
* debugging logs between the main `lightningd` and whatever
* plugin is using the paymod system.
* We only fall back to a unique id per root payment if there
* is no command with an id associated with this payment.
*/
if (root->cmd && root->cmd->id) {
*type = "cmd";
*id = *root->cmd->id;
} else {
*type = "id";
*id = root->id;
}
}
static void
paymod_log(struct payment *p, enum log_level l, const char *fmt, ...)
{
const char *type;
u64 id;
char *txt;
va_list ap;
va_start(ap, fmt);
txt = tal_vfmt(tmpctx, fmt, ap);
va_end(ap);
paymod_log_header(p, &type, &id);
plugin_log(p->plugin, l, "%s %"PRIu64" partid %"PRIu32": %s",
type, id, p->partid, txt);
}
static void
paymod_err(struct payment *p, const char *fmt, ...)
{
const char *type;
u64 id;
char *txt;
va_list ap;
va_start(ap, fmt);
txt = tal_vfmt(tmpctx, fmt, ap);
va_end(ap);
paymod_log_header(p, &type, &id);
plugin_err(p->plugin, "%s %"PRIu64" partid %"PRIu32": %s",
type, id, p->partid, txt);
}
/* Generic handler for RPC failures that should end up failing the payment. */
static struct command_result *payment_rpc_failure(struct command *cmd,
const char *buffer,
const jsmntok_t *toks,
struct payment *p)
{
payment_fail(p,
"Failing a partial payment due to a failed RPC call: %.*s",
toks->end - toks->start, buffer + toks->start);
return command_still_pending(cmd);
}
struct payment_tree_result payment_collect_result(struct payment *p)
{
struct payment_tree_result res;
size_t numchildren = tal_count(p->children);
res.sent = AMOUNT_MSAT(0);
res.attempts = 1;
res.treestates = p->step;
res.leafstates = 0;
res.preimage = NULL;
res.failure = NULL;
if (p->step == PAYMENT_STEP_FAILED && p->result != NULL)
res.failure = p->result;
if (numchildren == 0) {
res.leafstates |= p->step;
if (p->result && p->result->state == PAYMENT_COMPLETE) {
res.sent = p->result->amount_sent;
res.preimage = p->result->payment_preimage;
}
}
for (size_t i = 0; i < numchildren; i++) {
struct payment_tree_result cres =
payment_collect_result(p->children[i]);
/* Some of our subpayments have succeeded, aggregate how much
* we sent in total. */
if (!amount_msat_add(&res.sent, res.sent, cres.sent))
paymod_err(
p,
"Number overflow summing partial payments: %s + %s",
type_to_string(tmpctx, struct amount_msat,
&res.sent),
type_to_string(tmpctx, struct amount_msat,
&cres.sent));
/* Bubble up the first preimage we see. */
if (res.preimage == NULL && cres.preimage != NULL)
res.preimage = cres.preimage;
res.leafstates |= cres.leafstates;
res.treestates |= cres.treestates;
res.attempts += cres.attempts;
/* We bubble the failure result with the highest failcode up
* to the root. */
if (res.failure == NULL ||
(cres.failure != NULL &&
cres.failure->failcode > res.failure->failcode)) {
res.failure = cres.failure;
}
}
return res;
}
static struct command_result *
payment_getblockheight_success(struct command *cmd,
const char *buffer,
const jsmntok_t *toks,
struct payment *p)
{
const jsmntok_t *blockheighttok =
json_get_member(buffer, toks, "blockheight");
json_to_number(buffer, blockheighttok, &p->start_block);
payment_continue(p);
return command_still_pending(cmd);
}
#define INVALID_BLOCKHEIGHT UINT32_MAX
static
void payment_start_at_blockheight(struct payment *p, u32 blockheight)
{
struct payment *root = payment_root(p);
/* Should have been set in root payment, or propagated from root
* payment to all child payments. */
assert(p->local_id);
p->step = PAYMENT_STEP_INITIALIZED;
p->current_modifier = -1;
/* Pre-generate the getroute request, so modifiers can have their say,
* before we actually call `getroute` */
p->getroute->destination = p->destination;
p->getroute->max_hops = ROUTING_MAX_HOPS;
p->getroute->cltv = root->min_final_cltv_expiry;
p->getroute->amount = p->amount;
p->start_constraints = tal_dup(p, struct payment_constraints, &p->constraints);
if (blockheight != INVALID_BLOCKHEIGHT) {
/* The caller knows the actual blockheight. */
p->start_block = blockheight;
return payment_continue(p);
}
if (p->parent) {
/* The parent should have a start block. */
p->start_block = p->parent->start_block;
return payment_continue(p);
}
/* `waitblockheight 0` can be used as a query for the current
* block height.
* This is slightly better than `getinfo` since `getinfo`
* counts the channels and addresses and pushes more data
* onto the RPC but all we care about is the blockheight.
*/
struct out_req *req;
req = jsonrpc_request_start(p->plugin, NULL, "waitblockheight",
&payment_getblockheight_success,
&payment_rpc_failure, p);
json_add_u32(req->js, "blockheight", 0);
send_outreq(p->plugin, req);
}
void payment_start(struct payment *p)
{
payment_start_at_blockheight(p, INVALID_BLOCKHEIGHT);
}
static void channel_hints_update(struct payment *p,
const struct short_channel_id scid,
int direction, bool enabled, bool local,
const struct amount_msat *estimated_capacity,
u16 *htlc_budget)
{
struct payment *root = payment_root(p);
struct channel_hint newhint;
/* If the channel is marked as enabled it must have an estimate. */
assert(!enabled || estimated_capacity != NULL);
/* Try and look for an existing hint: */
for (size_t i=0; i<tal_count(root->channel_hints); i++) {
struct channel_hint *hint = &root->channel_hints[i];
if (short_channel_id_eq(&hint->scid.scid, &scid) &&
hint->scid.dir == direction) {
bool modified = false;
/* Prefer to disable a channel. */
if (!enabled && hint->enabled) {
hint->enabled = false;
modified = true;
}
/* Prefer the more conservative estimate. */
if (estimated_capacity != NULL &&
amount_msat_greater(hint->estimated_capacity,
*estimated_capacity)) {
hint->estimated_capacity = *estimated_capacity;
modified = true;
}
if (htlc_budget != NULL) {
assert(hint->local);
hint->local->htlc_budget = *htlc_budget;
modified = true;
}
if (modified)
paymod_log(p, LOG_DBG,
"Updated a channel hint for %s: "
"enabled %s, "
"estimated capacity %s",
type_to_string(tmpctx,
struct short_channel_id_dir,
&hint->scid),
hint->enabled ? "true" : "false",
type_to_string(tmpctx,
struct amount_msat,
&hint->estimated_capacity));
return;
}
}
/* No hint found, create one. */
newhint.enabled = enabled;
newhint.scid.scid = scid;
newhint.scid.dir = direction;
if (local) {
newhint.local = tal(root->channel_hints, struct local_hint);
assert(htlc_budget);
newhint.local->htlc_budget = *htlc_budget;
} else
newhint.local = NULL;
if (estimated_capacity != NULL)
newhint.estimated_capacity = *estimated_capacity;
tal_arr_expand(&root->channel_hints, newhint);
paymod_log(
p, LOG_DBG,
"Added a channel hint for %s: enabled %s, estimated capacity %s",
type_to_string(tmpctx, struct short_channel_id_dir, &newhint.scid),
newhint.enabled ? "true" : "false",
type_to_string(tmpctx, struct amount_msat,
&newhint.estimated_capacity));
}
static void payment_exclude_most_expensive(struct payment *p)
{
struct route_hop *e = &p->route[0];
struct amount_msat fee, worst = AMOUNT_MSAT(0);
for (size_t i = 0; i < tal_count(p->route)-1; i++) {
if (!amount_msat_sub(&fee, p->route[i].amount, p->route[i+1].amount))
paymod_err(p, "Negative fee in a route.");
if (amount_msat_greater_eq(fee, worst)) {
e = &p->route[i];
worst = fee;
}
}
channel_hints_update(p, e->scid, e->direction, false, false,
NULL, NULL);
}
static void payment_exclude_longest_delay(struct payment *p)
{
struct route_hop *e = &p->route[0];
u32 delay, worst = 0;
for (size_t i = 0; i < tal_count(p->route)-1; i++) {
delay = p->route[i].delay - p->route[i+1].delay;
if (delay >= worst) {
e = &p->route[i];
worst = delay;
}
}
channel_hints_update(p, e->scid, e->direction, false, false,
NULL, NULL);
}
static struct amount_msat payment_route_fee(struct payment *p)
{
struct amount_msat fee;
if (!amount_msat_sub(&fee, p->route[0].amount, p->amount)) {
paymod_log(
p,
LOG_BROKEN,
"gossipd returned a route with a negative fee: sending %s "
"to deliver %s",
type_to_string(tmpctx, struct amount_msat,
&p->route[0].amount),
type_to_string(tmpctx, struct amount_msat, &p->amount));
abort();
}
return fee;
}
/* Update the constraints by subtracting the delta_fee and delta_cltv if the
* result is positive. Returns whether or not the update has been applied. */
static WARN_UNUSED_RESULT bool
payment_constraints_update(struct payment_constraints *cons,
const struct amount_msat delta_fee,
const u32 delta_cltv)
{
if (delta_cltv > cons->cltv_budget)
return false;
/* amount_msat_sub performs a check before actually subtracting. */
if (!amount_msat_sub(&cons->fee_budget, cons->fee_budget, delta_fee))
return false;
cons->cltv_budget -= delta_cltv;
return true;
}
static struct channel_hint *payment_chanhints_get(struct payment *p,
struct route_hop *h)
{
struct payment *root = payment_root(p);
struct channel_hint *curhint;
for (size_t j = 0; j < tal_count(root->channel_hints); j++) {
curhint = &root->channel_hints[j];
if (short_channel_id_eq(&curhint->scid.scid, &h->scid) &&
curhint->scid.dir == h->direction) {
return curhint;
}
}
return NULL;
}
/* Given a route and a couple of channel hints, apply the route to the channel
* hints, so we have a better estimation of channel's capacity. We apply a
* route to a channel hint before calling `sendonion` so subsequent `route`
* calls don't accidentally try to use those out-of-date estimates. We unapply
* if the payment failed, i.e., all HTLCs we might have added have been torn
* down again. Finally we leave the update in place if the payment went
* through, since the balances really changed in that case. The `remove`
* argument indicates whether we want to apply (`remove=false`), or clear a
* prior application (`remove=true`). */
static bool payment_chanhints_apply_route(struct payment *p, bool remove)
{
bool apply;
struct route_hop *curhop;
struct channel_hint *curhint;
struct payment *root = payment_root(p);
assert(p->route != NULL);
/* No need to check for applicability if we increase
* capacity and budgets. */
if (remove)
goto apply_changes;
/* First round: make sure we can cleanly apply the update. */
for (size_t i = 0; i < tal_count(p->route); i++) {
curhop = &p->route[i];
curhint = payment_chanhints_get(root, curhop);
/* If we don't have a hint we can't fail updating it. */
if (!curhint)
continue;
/* For local channels we check that we don't overwhelm
* them with too many HTLCs. */
apply = (!curhint->local) ||
(curhint->local->htlc_budget > 0);
/* For all channels we check that they have a
* sufficiently large estimated capacity to have some
* chance of succeeding. */
apply &= amount_msat_greater_eq(curhint->estimated_capacity,
curhop->amount);
if (!apply) {
/* This can happen in case of multiple
* concurrent getroute calls using the
* same channel_hints, no biggy, it's
* an estimation anyway. */
paymod_log(p, LOG_DBG,
"Could not update the channel hint "
"for %s. Could be a concurrent "
"`getroute` call.",
type_to_string(tmpctx,
struct short_channel_id_dir,
&curhint->scid));
paymod_log(
p, LOG_DBG,
"Capacity: estimated_capacity=%s, hop_amount=%s. "
"local=%s%s",
type_to_string(tmpctx, struct amount_msat,
&curhint->estimated_capacity),
type_to_string(tmpctx, struct amount_msat,
&curhop->amount),
curhint->local ? "Y" : "N",
curhint->local ?
tal_fmt(tmpctx, " HTLC Budget: htlc_budget=%d",
curhint->local->htlc_budget) : "");
return false;
}
}
apply_changes:
/* Second round: apply the changes, now that we know they'll succeed. */
for (size_t i = 0; i < tal_count(p->route); i++) {
curhop = &p->route[i];
curhint = payment_chanhints_get(root, curhop);
if (!curhint)
continue;
/* Update the number of htlcs for any local
* channel in the route */
if (curhint->local) {
if (remove)
curhint->local->htlc_budget++;
else
curhint->local->htlc_budget--;
}
if (remove && !amount_msat_add(
&curhint->estimated_capacity,
curhint->estimated_capacity,
curhop->amount)) {
/* This should never happen, it'd mean
* that we unapply a route that would
* result in a msatoshi
* wrap-around. */
abort();
} else if (!amount_msat_sub(
&curhint->estimated_capacity,
curhint->estimated_capacity,
curhop->amount)) {
/* Given our preemptive test
* above, this should never
* happen either. */
abort();
}
}
return true;
}
static const struct short_channel_id_dir *
payment_get_excluded_channels(const tal_t *ctx, struct payment *p)
{
struct payment *root = payment_root(p);
struct channel_hint *hint;
struct short_channel_id_dir *res =
tal_arr(ctx, struct short_channel_id_dir, 0);
for (size_t i = 0; i < tal_count(root->channel_hints); i++) {
hint = &root->channel_hints[i];
if (!hint->enabled)
tal_arr_expand(&res, hint->scid);
else if (amount_msat_greater(p->amount,
hint->estimated_capacity))
tal_arr_expand(&res, hint->scid);
else if (hint->local && hint->local->htlc_budget == 0)
/* If we cannot add any HTLCs to the channel we
* shouldn't look for a route through that channel */
tal_arr_expand(&res, hint->scid);
}
return res;
}
static const struct node_id *payment_get_excluded_nodes(const tal_t *ctx,
struct payment *p)
{
struct payment *root = payment_root(p);
return root->excluded_nodes;
}
/* FIXME: This is slow! */
static const struct channel_hint *find_hint(const struct channel_hint *hints,
const struct short_channel_id *scid,
int dir)
{
for (size_t i = 0; i < tal_count(hints); i++) {
if (short_channel_id_eq(scid, &hints[i].scid.scid)
&& dir == hints[i].scid.dir)
return &hints[i];
}
return NULL;
}
/* FIXME: This is slow! */
static bool dst_is_excluded(const struct gossmap *gossmap,
const struct gossmap_chan *c,
int dir,
const struct node_id *nodes)
{
struct node_id dstid;
/* Premature optimization */
if (!tal_count(nodes))
return false;
gossmap_node_get_id(gossmap, gossmap_nth_node(gossmap, c, !dir),
&dstid);
for (size_t i = 0; i < tal_count(nodes); i++) {
if (node_id_eq(&dstid, &nodes[i]))
return true;
}
return false;
}
static bool payment_route_check(const struct gossmap *gossmap,
const struct gossmap_chan *c,
int dir,
struct amount_msat amount,
struct payment *p)
{
struct short_channel_id scid;
const struct channel_hint *hint;
if (dst_is_excluded(gossmap, c, dir, payment_root(p)->excluded_nodes))
return false;
if (dst_is_excluded(gossmap, c, dir, p->temp_exclusion))
return false;
scid = gossmap_chan_scid(gossmap, c);
hint = find_hint(payment_root(p)->channel_hints, &scid, dir);
if (!hint)
return true;
if (!hint->enabled)
return false;
if (amount_msat_greater_eq(amount, hint->estimated_capacity))
/* We exclude on equality because we've set the
* estimate to the smallest failed attempt. */
return false;
if (hint->local && hint->local->htlc_budget == 0)
/* If we cannot add any HTLCs to the channel we
* shouldn't look for a route through that channel */
return false;
return true;
}
static bool payment_route_can_carry(const struct gossmap *map,
const struct gossmap_chan *c,
int dir,
struct amount_msat amount,
struct payment *p)
{
if (!route_can_carry(map, c, dir, amount, p))
return false;
return payment_route_check(map, c, dir, amount, p);
}
static bool payment_route_can_carry_even_disabled(const struct gossmap *map,
const struct gossmap_chan *c,
int dir,
struct amount_msat amount,
struct payment *p)
{
if (!route_can_carry_even_disabled(map, c, dir, amount, p))
return false;
return payment_route_check(map, c, dir, amount, p);
}
/* Rene Pickhardt:
*
* Btw the linear term of the Taylor series of -log((c+1-x)/(c+1)) is 1/(c+1)
* meaning that another suitable Weight for Dijkstra would be amt/(c+1) +
* \mu*fee(amt) which is the linearized version which for small amounts and
* suitable value of \mu should be good enough)
*/
static u64 capacity_bias(const struct gossmap *map,
const struct gossmap_chan *c,
int dir,
struct amount_msat amount)
{
struct amount_sat capacity;
u64 amtmsat = amount.millisatoshis; /* Raw: lengthy math */
double capmsat;
/* Can fail in theory if gossmap changed underneath. */
if (!gossmap_chan_get_capacity(map, c, &capacity))
return 0;
capmsat = (double)capacity.satoshis * 1000; /* Raw: lengthy math */
return -log((capmsat + 1 - amtmsat) / (capmsat + 1));
}
/* Prioritize costs over distance, but bias to larger channels. */
static u64 route_score(u32 distance,
struct amount_msat cost,
struct amount_msat risk,
int dir,
const struct gossmap_chan *c)
{
u64 cmsat = cost.millisatoshis; /* Raw: lengthy math */
u64 rmsat = risk.millisatoshis; /* Raw: lengthy math */
u64 bias = capacity_bias(global_gossmap, c, dir, cost);
/* Smoothed harmonic mean to avoid division by 0 */
u64 costs = (cmsat * rmsat * bias) / (cmsat + rmsat + bias + 1);
if (costs > 0xFFFFFFFF)
costs = 0xFFFFFFFF;
return costs;
}
static struct route_hop *route(const tal_t *ctx,
struct gossmap *gossmap,
const struct gossmap_node *src,
const struct gossmap_node *dst,
struct amount_msat amount,
u32 final_delay,
double riskfactor,
size_t max_hops,
struct payment *p,
const char **errmsg)
{
const struct dijkstra *dij;
struct route_hop *r;
bool (*can_carry)(const struct gossmap *,
const struct gossmap_chan *,
int,
struct amount_msat,
struct payment *);
can_carry = payment_route_can_carry;
dij = dijkstra(tmpctx, gossmap, dst, amount, riskfactor,
can_carry, route_score, p);
r = route_from_dijkstra(ctx, gossmap, dij, src, amount, final_delay);
if (!r) {
/* Try using disabled channels too */
/* FIXME: is there somewhere we can annotate this for paystatus? */
can_carry = payment_route_can_carry_even_disabled;
dij = dijkstra(tmpctx, gossmap, dst, amount, riskfactor,
can_carry, route_score, p);
r = route_from_dijkstra(ctx, gossmap, dij, src,
amount, final_delay);
if (!r) {
*errmsg = "No path found";
return NULL;
}
}
/* If it's too far, fall back to using shortest path. */
if (tal_count(r) > max_hops) {
tal_free(r);
/* FIXME: is there somewhere we can annotate this for paystatus? */
dij = dijkstra(tmpctx, gossmap, dst, amount, riskfactor,
can_carry, route_score_shorter, p);
r = route_from_dijkstra(ctx, gossmap, dij, src,
amount, final_delay);
if (!r) {
*errmsg = "No path found";
return NULL;
}
/* If it's still too far, fail. */
if (tal_count(r) > max_hops) {
*errmsg = tal_fmt(ctx, "Shortest path found was length %zu",
tal_count(r));
return tal_free(r);
}
}
return r;
}
static struct command_result *payment_getroute(struct payment *p)
{
const struct gossmap_node *dst, *src;
struct amount_msat fee;
const char *errstr;
struct gossmap *gossmap;
/* If we retry the getroute call we might already have a route, so
* free an eventual stale route. */
p->route = tal_free(p->route);
gossmap = get_gossmap(p->plugin);
dst = gossmap_find_node(gossmap, p->getroute->destination);
if (!dst) {
payment_fail(
p, "Unknown destination %s",
type_to_string(tmpctx, struct node_id,
p->getroute->destination));
/* Let payment_finished_ handle this, so we mark it as pending */
return command_still_pending(p->cmd);
}
/* If we don't exist in gossip, routing can't happen. */
src = gossmap_find_node(gossmap, p->local_id);
if (!src) {
payment_fail(p, "We don't have any channels");
/* Let payment_finished_ handle this, so we mark it as pending */
return command_still_pending(p->cmd);
}
p->route = route(p, gossmap, src, dst, p->getroute->amount, p->getroute->cltv,
p->getroute->riskfactorppm / 1000000.0, p->getroute->max_hops,
p, &errstr);
if (!p->route) {
payment_fail(p, "%s", errstr);
/* Let payment_finished_ handle this, so we mark it as pending */
return command_still_pending(p->cmd);
}
/* OK, now we *have* a route */
p->step = PAYMENT_STEP_GOT_ROUTE;
if (tal_count(p->route) == 0) {
payment_root(p)->abort = true;
payment_fail(p, "Empty route returned by getroute, are you "
"trying to pay yourself?");
}
fee = payment_route_fee(p);
/* Ensure that our fee and CLTV budgets are respected. */
if (amount_msat_greater(fee, p->constraints.fee_budget)) {
payment_exclude_most_expensive(p);
p->route = tal_free(p->route);
payment_fail(
p, "Fee exceeds our fee budget: %s > %s, discarding route",
type_to_string(tmpctx, struct amount_msat, &fee),
type_to_string(tmpctx, struct amount_msat,
&p->constraints.fee_budget));
return command_still_pending(p->cmd);
}
if (p->route[0].delay > p->constraints.cltv_budget) {
u32 delay = p->route[0].delay;
payment_exclude_longest_delay(p);
p->route = tal_free(p->route);
payment_fail(p, "CLTV delay exceeds our CLTV budget: %d > %d",
delay, p->constraints.cltv_budget);
return command_still_pending(p->cmd);
}
/* Now update the constraints in fee_budget and cltv_budget so
* modifiers know what constraints they need to adhere to. */
if (!payment_constraints_update(&p->constraints, fee, p->route[0].delay)) {
paymod_log(p, LOG_BROKEN,
"Could not update constraints.");
abort();
}
/* Allow modifiers to modify the route, before
* payment_compute_onion_payloads uses the route to generate the
* onion_payloads */
payment_continue(p);
return command_still_pending(p->cmd);
}
static struct payment_result *tal_sendpay_result_from_json(const tal_t *ctx,
const char *buffer,
const jsmntok_t *toks)
{
const jsmntok_t *idtok = json_get_member(buffer, toks, "id");
const jsmntok_t *hashtok = json_get_member(buffer, toks, "payment_hash");
const jsmntok_t *partidtok = json_get_member(buffer, toks, "partid");
const jsmntok_t *senttok = json_get_member(buffer, toks, "amount_sent_msat");
const jsmntok_t *statustok = json_get_member(buffer, toks, "status");
const jsmntok_t *preimagetok = json_get_member(buffer, toks, "payment_preimage");
const jsmntok_t *codetok = json_get_member(buffer, toks, "code");
const jsmntok_t *datatok = json_get_member(buffer, toks, "data");
const jsmntok_t *erridxtok, *msgtok, *failcodetok, *rawmsgtok,
*failcodenametok, *errchantok, *errnodetok, *errdirtok;
struct payment_result *result;
/* Check if we have an error and need to descend into data to get
* details. */
if (codetok != NULL && datatok != NULL) {
idtok = json_get_member(buffer, datatok, "id");
hashtok = json_get_member(buffer, datatok, "payment_hash");
partidtok = json_get_member(buffer, datatok, "partid");
senttok = json_get_member(buffer, datatok, "amount_sent_msat");
statustok = json_get_member(buffer, datatok, "status");
}
/* Initial sanity checks, all these fields must exist. */
if (idtok == NULL || idtok->type != JSMN_PRIMITIVE ||
hashtok == NULL || hashtok->type != JSMN_STRING ||
senttok == NULL ||
statustok == NULL || statustok->type != JSMN_STRING) {
return NULL;
}
result = tal(ctx, struct payment_result);
if (codetok != NULL)
json_to_u32(buffer, codetok, &result->code);
else
result->code = 0;
/* If the partid is 0 it'd be omitted in waitsendpay, fix this here. */
if (partidtok != NULL)
json_to_u32(buffer, partidtok, &result->partid);
else
result->partid = 0;
json_to_u64(buffer, idtok, &result->id);
json_to_msat(buffer, senttok, &result->amount_sent);
if (json_tok_streq(buffer, statustok, "pending")) {
result->state = PAYMENT_PENDING;
} else if (json_tok_streq(buffer, statustok, "complete")) {
result->state = PAYMENT_COMPLETE;
} else if (json_tok_streq(buffer, statustok, "failed")) {
result->state = PAYMENT_FAILED;
} else {
goto fail;
}
if (preimagetok != NULL) {
result->payment_preimage = tal(result, struct preimage);
json_to_preimage(buffer, preimagetok, result->payment_preimage);
}
/* Now extract the error details if the error code is not 0 */
if (result->code != 0) {
erridxtok = json_get_member(buffer, datatok, "erring_index");
errnodetok = json_get_member(buffer, datatok, "erring_node");
errchantok = json_get_member(buffer, datatok, "erring_channel");
errdirtok = json_get_member(buffer, datatok, "erring_direction");
failcodetok = json_get_member(buffer, datatok, "failcode");
failcodenametok =json_get_member(buffer, datatok, "failcodename");
msgtok = json_get_member(buffer, toks, "message");
rawmsgtok = json_get_member(buffer, datatok, "raw_message");
if (failcodetok == NULL || failcodetok->type != JSMN_PRIMITIVE ||
(failcodenametok != NULL && failcodenametok->type != JSMN_STRING) ||
(erridxtok != NULL && erridxtok->type != JSMN_PRIMITIVE) ||
(errnodetok != NULL && errnodetok->type != JSMN_STRING) ||
(errchantok != NULL && errchantok->type != JSMN_STRING) ||
(errdirtok != NULL && errdirtok->type != JSMN_PRIMITIVE) ||
msgtok == NULL || msgtok->type != JSMN_STRING ||
(rawmsgtok != NULL && rawmsgtok->type != JSMN_STRING))
goto fail;
if (rawmsgtok != NULL)
result->raw_message = json_tok_bin_from_hex(result, buffer, rawmsgtok);
else
result->raw_message = NULL;
if (failcodenametok != NULL)
result->failcodename = json_strdup(result, buffer, failcodenametok);
else
result->failcodename = NULL;
json_to_u32(buffer, failcodetok, &result->failcode);
result->message = json_strdup(result, buffer, msgtok);
if (erridxtok != NULL) {
result->erring_index = tal(result, u32);
json_to_u32(buffer, erridxtok, result->erring_index);
} else {
result->erring_index = NULL;
}
if (errdirtok != NULL) {
result->erring_direction = tal(result, int);
json_to_int(buffer, errdirtok, result->erring_direction);
} else {
result->erring_direction = NULL;
}
if (errnodetok != NULL) {
result->erring_node = tal(result, struct node_id);
json_to_node_id(buffer, errnodetok,
result->erring_node);
} else {
result->erring_node = NULL;
}
if (errchantok != NULL) {
result->erring_channel =
tal(result, struct short_channel_id);
json_to_short_channel_id(buffer, errchantok,
result->erring_channel);
} else {
result->erring_channel = NULL;
}
}
return result;
fail:
return tal_free(result);
}
/* Try to infer the erring_node, erring_channel and erring_direction from what
* we know, but don't override the values that are returned by `waitsendpay`. */
static void payment_result_infer(struct route_hop *route,
struct payment_result *r)
{
int i, len;
assert(r != NULL);
if (r->code == 0 || r->erring_index == NULL || route == NULL)
return;
len = tal_count(route);
i = *r->erring_index;
assert(i <= len);
if (r->erring_node == NULL)
r->erring_node = &route[i-1].node_id;
/* The above assert was enough for the erring_node, but might be off
* by one on channel and direction, in case the destination failed on
* us. */
if (i == len)
return;
if (r->erring_channel == NULL)
r->erring_channel = &route[i].scid;
if (r->erring_direction == NULL)
r->erring_direction = &route[i].direction;
}
/* If a node takes too much fee or cltv, the next one reports it. We don't
* know who to believe, but log it */
static void report_tampering(struct payment *p,
size_t report_pos,
const char *style)
{
const struct node_id *id = &p->route[report_pos].node_id;
if (report_pos == 0) {
paymod_log(p, LOG_UNUSUAL,
"Node #%zu (%s) claimed we sent them invalid %s",
report_pos + 1,
type_to_string(tmpctx, struct node_id, id),
style);
} else {
paymod_log(p, LOG_UNUSUAL,
"Node #%zu (%s) claimed #%zu (%s) sent them invalid %s",
report_pos + 1,
type_to_string(tmpctx, struct node_id, id),
report_pos,
type_to_string(tmpctx, struct node_id,
&p->route[report_pos-1].node_id),
style);
}
}
static bool
failure_is_blockheight_disagreement(const struct payment *p,
u32 *blockheight)
{
struct amount_msat unused;
assert(p && p->result);
if (p->result->failcode == 17 /* Former final_expiry_too_soon */)
*blockheight = p->start_block + 1;
else if (!fromwire_incorrect_or_unknown_payment_details(
p->result->raw_message,
&unused, blockheight))
/* If it's incorrect_or_unknown_payment_details, that tells us
* what height they're at */
return false;
/* If we are already at the desired blockheight there is no point in
* waiting, and it is likely just some other error. Notice that
* start_block gets set by the initial getinfo call for each
* attempt.*/
if (*blockheight <= p->start_block)
return false;
return true;
}
static char *describe_failcode(const tal_t *ctx, enum onion_wire failcode)
{
char *rv = tal_strdup(ctx, "");
if (failcode & BADONION) {
tal_append_fmt(&rv, "BADONION|");
failcode &= ~BADONION;
}
if (failcode & PERM) {
tal_append_fmt(&rv, "PERM|");
failcode &= ~PERM;
}
if (failcode & NODE) {
tal_append_fmt(&rv, "NODE|");
failcode &= ~NODE;
}
if (failcode & UPDATE) {
tal_append_fmt(&rv, "UPDATE|");
failcode &= ~UPDATE;
}
tal_append_fmt(&rv, "%u", failcode);
return rv;
}
static struct command_result *
handle_final_failure(struct command *cmd,
struct payment *p,
const struct node_id *final_id,
enum onion_wire failcode)
{
u32 unused;
/* Need to check for blockheight disagreement case here,
* otherwise we would set the abort flag too eagerly.
*/
if (failure_is_blockheight_disagreement(p, &unused)) {
paymod_log(p, LOG_DBG,
"Blockheight disagreement, not aborting.");
goto nonerror;
}
paymod_log(p, LOG_DBG,
"Final node %s reported %04x (%s) on route %s",
type_to_string(tmpctx, struct node_id, final_id),
failcode, onion_wire_name(failcode),
p->routetxt);
/* We use an exhaustive switch statement here so you get a compile
* warning when new ones are added, and can think about where they go */
switch (failcode) {
case WIRE_FINAL_INCORRECT_CLTV_EXPIRY:
report_tampering(p, tal_count(p->route)-1, "cltv");
goto error;
case WIRE_FINAL_INCORRECT_HTLC_AMOUNT:
report_tampering(p, tal_count(p->route)-1, "amount");
goto error;
/* BOLT #4:
*
* A _forwarding node_ MAY, but a _final node_ MUST NOT:
*...
* - return an `invalid_onion_version` error.
*...
* - return an `invalid_onion_hmac` error.
*...
* - return an `invalid_onion_key` error.
*...
* - return a `temporary_channel_failure` error.
*...
* - return a `permanent_channel_failure` error.
*...
* - return a `required_channel_feature_missing` error.
*...
* - return an `unknown_next_peer` error.
*...
* - return an `amount_below_minimum` error.
*...
* - return a `fee_insufficient` error.
*...
* - return an `incorrect_cltv_expiry` error.
*...
* - return an `expiry_too_soon` error.
*...
* - return an `expiry_too_far` error.
*...
* - return a `channel_disabled` error.
*/
case WIRE_INVALID_ONION_VERSION:
case WIRE_INVALID_ONION_HMAC:
case WIRE_INVALID_ONION_KEY:
case WIRE_TEMPORARY_CHANNEL_FAILURE:
case WIRE_PERMANENT_CHANNEL_FAILURE:
case WIRE_REQUIRED_CHANNEL_FEATURE_MISSING:
case WIRE_UNKNOWN_NEXT_PEER:
case WIRE_AMOUNT_BELOW_MINIMUM:
case WIRE_FEE_INSUFFICIENT:
case WIRE_INCORRECT_CLTV_EXPIRY:
case WIRE_EXPIRY_TOO_FAR:
case WIRE_EXPIRY_TOO_SOON:
case WIRE_CHANNEL_DISABLED:
goto strange_error;
case WIRE_INVALID_ONION_PAYLOAD:
case WIRE_INVALID_REALM:
case WIRE_PERMANENT_NODE_FAILURE:
case WIRE_TEMPORARY_NODE_FAILURE:
case WIRE_REQUIRED_NODE_FEATURE_MISSING:
case WIRE_INVALID_ONION_BLINDING:
case WIRE_INCORRECT_OR_UNKNOWN_PAYMENT_DETAILS:
case WIRE_MPP_TIMEOUT:
goto error;
}
strange_error:
paymod_log(p, LOG_UNUSUAL,
"Final node %s reported strange error code %04x (%s)",
type_to_string(tmpctx, struct node_id, final_id),
failcode, describe_failcode(tmpctx, failcode));
error:
p->result->code = PAY_DESTINATION_PERM_FAIL;
payment_root(p)->abort = true;
nonerror:
payment_fail(p, "%s", p->result->message);
return command_still_pending(cmd);
}
static struct command_result *
handle_intermediate_failure(struct command *cmd,
struct payment *p,
const struct node_id *errnode,
const struct route_hop *errchan,
enum onion_wire failcode)
{
struct payment *root = payment_root(p);
struct amount_msat estimated;
paymod_log(p, LOG_DBG,
"Intermediate node %s reported %04x (%s) at %s on route %s",
type_to_string(tmpctx, struct node_id, errnode),
failcode, onion_wire_name(failcode),
type_to_string(tmpctx, struct short_channel_id,
&errchan->scid),
p->routetxt);
/* We use an exhaustive switch statement here so you get a compile
* warning when new ones are added, and can think about where they go */
switch (failcode) {
/* BOLT #4:
*
* An _intermediate hop_ MUST NOT, but the _final node_:
*...
* - MUST return an `incorrect_or_unknown_payment_details` error.
*...
* - MUST return `final_incorrect_cltv_expiry` error.
*...
* - MUST return a `final_incorrect_htlc_amount` error.
*/
case WIRE_INCORRECT_OR_UNKNOWN_PAYMENT_DETAILS:
case WIRE_FINAL_INCORRECT_CLTV_EXPIRY:
case WIRE_FINAL_INCORRECT_HTLC_AMOUNT:
/* FIXME: Document in BOLT that intermediates must not return this! */
case WIRE_MPP_TIMEOUT:
goto strange_error;
case WIRE_PERMANENT_CHANNEL_FAILURE:
case WIRE_CHANNEL_DISABLED:
case WIRE_UNKNOWN_NEXT_PEER:
case WIRE_REQUIRED_CHANNEL_FEATURE_MISSING:
/* All of these result in the channel being marked as disabled. */
channel_hints_update(root, errchan->scid,
errchan->direction, false, false, NULL,
NULL);
break;
case WIRE_TEMPORARY_CHANNEL_FAILURE: {
estimated = errchan->amount;
/* Subtract one msat more, since we know that the amount did not
* work. This allows us to then allow on equality, this is for
* example necessary for local channels where exact matches
* should be allowed. */
if (!amount_msat_sub(&estimated, estimated, AMOUNT_MSAT(1)))
abort();
/* These are an indication that the capacity was insufficient,
* remember the amount we tried as an estimate. */
channel_hints_update(root, errchan->scid,
errchan->direction, true, false,
&estimated, NULL);
goto error;
}
case WIRE_INCORRECT_CLTV_EXPIRY:
report_tampering(p, errchan - p->route, "cltv");
goto error;
case WIRE_INVALID_ONION_VERSION:
case WIRE_INVALID_ONION_HMAC:
case WIRE_INVALID_ONION_KEY:
case WIRE_PERMANENT_NODE_FAILURE:
case WIRE_TEMPORARY_NODE_FAILURE:
case WIRE_REQUIRED_NODE_FEATURE_MISSING:
case WIRE_INVALID_ONION_PAYLOAD:
case WIRE_INVALID_REALM:
case WIRE_INVALID_ONION_BLINDING:
tal_arr_expand(&root->excluded_nodes, *errnode);
goto error;
case WIRE_AMOUNT_BELOW_MINIMUM:
case WIRE_FEE_INSUFFICIENT:
case WIRE_EXPIRY_TOO_FAR:
case WIRE_EXPIRY_TOO_SOON:
goto error;
}
strange_error:
paymod_log(p, LOG_UNUSUAL,
"Intermediate node %s reported strange error code %04x (%s)",
type_to_string(tmpctx, struct node_id, errnode),
failcode, describe_failcode(tmpctx, failcode));
error:
payment_fail(p, "%s", p->result->message);
return command_still_pending(cmd);
}
/* From the docs:
*
* - *erring_index*: The index of the node along the route that
* reported the error. 0 for the local node, 1 for the first hop,
* and so on.
*
* The only difficulty is mapping the erring_index to the correct hop.
* We split into the erring node, and the error channel, since they're
* used in different contexts. NULL error_channel means it's the final
* node, whose errors are treated differently.
*/
static bool assign_blame(const struct payment *p,
const struct node_id **errnode,
const struct route_hop **errchan)
{
int index;
if (p->result->erring_index == NULL)
return false;
index = *p->result->erring_index;
/* BADONION errors are reported on behalf of the next node. */
if (p->result->failcode & BADONION)
index++;
/* Final node *shouldn't* report BADONION, but don't assume. */
if (index >= tal_count(p->route)) {
*errchan = NULL;
*errnode = &p->route[tal_count(p->route) - 1].node_id;
return true;
}
*errchan = &p->route[index];
if (index == 0)
*errnode = p->local_id;
else
*errnode = &p->route[index - 1].node_id;
return true;
}
/* Fix up the channel_update to include the type if it doesn't currently have
* one. See ElementsProject/lightning#1730 and lightningnetwork/lnd#1599 for the
* in-depth discussion on why we break message parsing here... */
static u8 *patch_channel_update(const tal_t *ctx, u8 *channel_update TAKES)
{
u8 *fixed;
if (channel_update != NULL &&
fromwire_peektype(channel_update) != WIRE_CHANNEL_UPDATE) {
/* This should be a channel_update, prefix with the
* WIRE_CHANNEL_UPDATE type, but isn't. Let's prefix it. */
fixed = tal_arr(ctx, u8, 0);
towire_u16(&fixed, WIRE_CHANNEL_UPDATE);
towire(&fixed, channel_update, tal_bytelen(channel_update));
if (taken(channel_update))
tal_free(channel_update);
return fixed;
} else {
return tal_dup_talarr(ctx, u8, channel_update);
}
}
/* Return NULL if the wrapped onion error message has no channel_update field,
* or return the embedded channel_update message otherwise. */
static u8 *channel_update_from_onion_error(const tal_t *ctx,
const u8 *onion_message)
{
u8 *channel_update = NULL;
struct amount_msat unused_msat;
u32 unused32;
/* Identify failcodes that have some channel_update.
*
* TODO > BOLT 1.0: Add new failcodes when updating to a
* new BOLT version. */
if (!fromwire_temporary_channel_failure(ctx,
onion_message,
&channel_update) &&
!fromwire_amount_below_minimum(ctx,
onion_message, &unused_msat,
&channel_update) &&
!fromwire_fee_insufficient(ctx,
onion_message, &unused_msat,
&channel_update) &&
!fromwire_incorrect_cltv_expiry(ctx,
onion_message, &unused32,
&channel_update) &&
!fromwire_expiry_too_soon(ctx,
onion_message,
&channel_update))
/* No channel update. */
return NULL;
return patch_channel_update(ctx, take(channel_update));
}
static struct command_result *
payment_addgossip_success(struct command *cmd, const char *buffer,
const jsmntok_t *toks, struct payment *p)
{
const struct node_id *errnode;
const struct route_hop *errchan;
if (!assign_blame(p, &errnode, &errchan)) {
paymod_log(p, LOG_UNUSUAL,
"No erring_index set in `waitsendpay` result: %.*s",
json_tok_full_len(toks),
json_tok_full(buffer, toks));
/* FIXME: Pick a random channel to fail? */
payment_set_step(p, PAYMENT_STEP_FAILED);
payment_continue(p);
return command_still_pending(cmd);
}
if (!errchan)
return handle_final_failure(cmd, p, errnode,
p->result->failcode);
return handle_intermediate_failure(cmd, p, errnode, errchan,
p->result->failcode);
}
/* If someone gives us an invalid update, all we can do is log it */
static struct command_result *
payment_addgossip_failure(struct command *cmd, const char *buffer,
const jsmntok_t *toks, struct payment *p)
{
paymod_log(p, LOG_DBG, "Invalid channel_update: %.*s",
json_tok_full_len(toks),
json_tok_full(buffer, toks));
return payment_addgossip_success(cmd, NULL, NULL, p);
}
static struct command_result *
payment_waitsendpay_finished(struct command *cmd, const char *buffer,
const jsmntok_t *toks, struct payment *p)
{
u8 *update;
assert(p->route != NULL);
p->end_time = time_now();
p->result = tal_sendpay_result_from_json(p, buffer, toks);
if (p->result == NULL) {
paymod_log(p, LOG_UNUSUAL,
"Unable to parse `waitsendpay` result: %.*s",
json_tok_full_len(toks),
json_tok_full(buffer, toks));
payment_set_step(p, PAYMENT_STEP_FAILED);
payment_continue(p);
return command_still_pending(cmd);
}
payment_result_infer(p->route, p->result);
if (p->result->state == PAYMENT_COMPLETE) {
payment_set_step(p, PAYMENT_STEP_SUCCESS);
payment_continue(p);
return command_still_pending(cmd);
}
payment_chanhints_apply_route(p, true);
/* Tell gossipd, if we received an update */
update = channel_update_from_onion_error(tmpctx, p->result->raw_message);
if (update) {
struct out_req *req;
paymod_log(p, LOG_DBG,
"Extracted channel_update %s from onionreply %s",
tal_hex(tmpctx, update),
tal_hex(tmpctx, p->result->raw_message));
req = jsonrpc_request_start(p->plugin, NULL, "addgossip",
payment_addgossip_success,
payment_addgossip_failure, p);
json_add_hex_talarr(req->js, "message", update);
send_outreq(p->plugin, req);
return command_still_pending(cmd);
}
return payment_addgossip_success(cmd, NULL, NULL, p);
}
static struct command_result *payment_sendonion_success(struct command *cmd,
const char *buffer,
const jsmntok_t *toks,
struct payment *p)
{
struct out_req *req;
req = jsonrpc_request_start(p->plugin, NULL, "waitsendpay",
payment_waitsendpay_finished,
payment_waitsendpay_finished, p);
json_add_sha256(req->js, "payment_hash", p->payment_hash);
json_add_num(req->js, "partid", p->partid);
json_add_u64(req->js, "groupid", p->groupid);
send_outreq(p->plugin, req);
return command_still_pending(cmd);
}
static struct command_result *payment_createonion_success(struct command *cmd,
const char *buffer,
const jsmntok_t *toks,
struct payment *p)
{
struct out_req *req;
struct route_hop *first = &p->route[0];
struct secret *secrets;
struct payment *root = payment_root(p);
p->createonion_response = json_to_createonion_response(p, buffer, toks);
req = jsonrpc_request_start(p->plugin, NULL, "sendonion",
payment_sendonion_success,
payment_rpc_failure, p);
json_add_hex_talarr(req->js, "onion", p->createonion_response->onion);
json_object_start(req->js, "first_hop");
json_add_amount_msat(req->js, "amount_msat", first->amount);
json_add_num(req->js, "delay", first->delay);
json_add_node_id(req->js, "id", &first->node_id);
json_add_short_channel_id(req->js, "channel", &first->scid);
json_object_end(req->js);
json_add_sha256(req->js, "payment_hash", p->payment_hash);
json_add_amount_msat(req->js, "amount_msat", p->amount);
json_array_start(req->js, "shared_secrets");
secrets = p->createonion_response->shared_secrets;
for(size_t i=0; i<tal_count(secrets); i++)
json_add_secret(req->js, NULL, &secrets[i]);
json_array_end(req->js);
json_add_num(req->js, "partid", p->partid);
json_add_u64(req->js, "groupid", p->groupid);
if (p->label)
json_add_string(req->js, "label", p->label);
if (!root->invstring_used) {
/* FIXME: rename parameter to invstring */
json_add_string(req->js, "bolt11", p->invstring);
if (p->description)
json_add_string(req->js, "description", p->description);
root->invstring_used = true;
}
if (p->destination)
json_add_node_id(req->js, "destination", p->destination);
if (p->local_invreq_id)
json_add_sha256(req->js, "localinvreqid", p->local_invreq_id);
send_outreq(p->plugin, req);
return command_still_pending(cmd);
}
/* Temporary serialization method for the tlv_payload.data until we rework the
* API that is generated from the specs to use the setter/getter interface. */
static void tlvstream_set_tlv_payload_data(struct tlv_field **stream,
const struct secret *payment_secret,
u64 total_msat)
{
u8 *ser = tal_arr(NULL, u8, 0);
towire_secret(&ser, payment_secret);
towire_tu64(&ser, total_msat);
tlvstream_set_raw(stream, TLV_PAYLOAD_PAYMENT_DATA, ser, tal_bytelen(ser));
tal_free(ser);
}
static void payment_add_hop_onion_payload(struct payment *p,
struct createonion_hop *dst,
struct route_hop *node,
struct route_hop *next,
bool final,
struct secret *payment_secret,
const u8 *payment_metadata)
{
struct createonion_request *cr = p->createonion_request;
u32 cltv = p->start_block + next->delay + 1;
u64 msat = next->amount.millisatoshis; /* Raw: TLV payload generation*/
struct tlv_field **fields;
struct payment *root = payment_root(p);
/* This is the information of the node processing this payload, while
* `next` are the instructions to include in the payload, which is
* basically the channel going to the next node. */
dst->pubkey = node->node_id;
dst->tlv_payload = tlv_payload_new(cr->hops);
fields = &dst->tlv_payload->fields;
tlvstream_set_tu64(fields, TLV_PAYLOAD_AMT_TO_FORWARD,
msat);
tlvstream_set_tu32(fields, TLV_PAYLOAD_OUTGOING_CLTV_VALUE,
cltv);
if (!final)
tlvstream_set_short_channel_id(fields,
TLV_PAYLOAD_SHORT_CHANNEL_ID,
&next->scid);
if (payment_secret != NULL) {
assert(final);
tlvstream_set_tlv_payload_data(
fields, payment_secret,
root->amount.millisatoshis); /* Raw: TLV payload generation*/
}
if (payment_metadata != NULL) {
assert(final);
tlvstream_set_raw(fields, TLV_PAYLOAD_PAYMENT_METADATA,
payment_metadata, tal_bytelen(payment_metadata));
}
}
static void payment_add_blindedpath(const tal_t *ctx,
struct createonion_hop *hops,
const struct blinded_path *bpath,
struct amount_msat final_amt,
u32 final_cltv)
{
/* It's a bit of a weird API for us, so we convert it back to
* the struct tlv_payload */
u8 **tlvs = blinded_onion_hops(tmpctx, final_amt, final_cltv,
final_amt, bpath);
for (size_t i = 0; i < tal_count(tlvs); i++) {
const u8 *cursor = tlvs[i];
size_t max = tal_bytelen(tlvs[i]);
/* First one has to use real node_id */
if (i == 0)
node_id_from_pubkey(&hops[i].pubkey,
&bpath->first_node_id);
else
node_id_from_pubkey(&hops[i].pubkey,
&bpath->path[i]->blinded_node_id);
/* Length is prepended, discard that first! */
fromwire_bigsize(&cursor, &max);
hops[i].tlv_payload = fromwire_tlv_payload(ctx, &cursor, &max);
}
}
static void payment_compute_onion_payloads(struct payment *p)
{
struct createonion_request *cr;
size_t hopcount;
struct payment *root = payment_root(p);
char *routetxt = tal_strdup(tmpctx, "");
p->step = PAYMENT_STEP_ONION_PAYLOAD;
hopcount = tal_count(p->route);
/* Now that we are about to fix the route parameters by
* encoding them in an onion is the right time to update the
* channel hints. */
if (!payment_chanhints_apply_route(p, false)) {
/* We can still end up with a failed channel_hints
* update, either because a plugin changed the route,
* or because a modifier was not synchronous, allowing
* for multiple concurrent routes being built. If that
* is the case, discard this route and retry. */
payment_set_step(p, PAYMENT_STEP_RETRY_GETROUTE);
return payment_continue(p);
}
/* Now compute the payload we're about to pass to `createonion` */
cr = p->createonion_request = tal(p, struct createonion_request);
cr->assocdata = tal_arr(cr, u8, 0);
towire_sha256(&cr->assocdata, p->payment_hash);
cr->session_key = NULL;
cr->hops = tal_arr(cr, struct createonion_hop,
tal_count(p->route)
+ (root->blindedpath ? tal_count(root->blindedpath->path) - 1: 0));
/* Non-final hops */
for (size_t i = 0; i < hopcount - 1; i++) {
/* The message is destined for hop i, but contains fields for
* i+1 */
payment_add_hop_onion_payload(p, &cr->hops[i], &p->route[i],
&p->route[i + 1], false,
NULL, NULL);
tal_append_fmt(&routetxt, "%s -> ",
type_to_string(tmpctx, struct short_channel_id,
&p->route[i].scid));
}
/* If we're headed to a blinded path, connect that now. */
if (root->blindedpath) {
payment_add_blindedpath(cr->hops, cr->hops + hopcount - 1,
root->blindedpath,
root->blindedfinalamount,
root->blindedfinalcltv);
tal_append_fmt(&routetxt, "%s -> blinded path (%zu hops)",
type_to_string(tmpctx, struct short_channel_id,
&p->route[hopcount-1].scid),
tal_count(root->blindedpath->path));
} else {
/* Final hop */
payment_add_hop_onion_payload(
p, &cr->hops[hopcount - 1], &p->route[hopcount - 1],
&p->route[hopcount - 1], true,
root->payment_secret,
root->payment_metadata);
tal_append_fmt(&routetxt, "%s",
type_to_string(tmpctx, struct short_channel_id,
&p->route[hopcount - 1].scid));
}
paymod_log(p, LOG_DBG,
"Created outgoing onion for route: %s", routetxt);
p->routetxt = tal_steal(p, routetxt);
/* Now allow all the modifiers to mess with the payloads, before we
* serialize via a call to createonion in the next step. */
payment_continue(p);
}
static void payment_sendonion(struct payment *p)
{
struct out_req *req;
u8 *payload, *tlv;
req = jsonrpc_request_start(p->plugin, NULL, "createonion",
payment_createonion_success,
payment_rpc_failure, p);
json_array_start(req->js, "hops");
for (size_t i = 0; i < tal_count(p->createonion_request->hops); i++) {
json_object_start(req->js, NULL);
struct createonion_hop *hop = &p->createonion_request->hops[i];
json_add_node_id(req->js, "pubkey", &hop->pubkey);
tlv = tal_arr(tmpctx, u8, 0);
towire_tlvstream_raw(&tlv, hop->tlv_payload->fields);
payload = tal_arr(tmpctx, u8, 0);
towire_bigsize(&payload, tal_bytelen(tlv));
towire(&payload, tlv, tal_bytelen(tlv));
json_add_hex_talarr(req->js, "payload", payload);
tal_free(tlv);
tal_free(payload);
json_object_end(req->js);
}
json_array_end(req->js);
json_add_hex_talarr(req->js, "assocdata",
p->createonion_request->assocdata);
if (p->createonion_request->session_key)
json_add_secret(req->js, "sessionkey",
p->createonion_request->session_key);
send_outreq(p->plugin, req);
}
/* Mutual recursion. */
static void payment_finished(struct payment *p);
/* A payment is finished if a) it is in a final state, of b) it's in a
* child-spawning state and all of its children are in a final state. */
static bool payment_is_finished(const struct payment *p)
{
top:
if (p->step == PAYMENT_STEP_FAILED || p->step == PAYMENT_STEP_SUCCESS || p->abort)
return true;
else if (p->step == PAYMENT_STEP_SPLIT || p->step == PAYMENT_STEP_RETRY) {
size_t num_children = tal_count(p->children);
/* Retry case will almost always have just one child, so avoid
* the overhead of pushing and popping off the C stack and
* tail-recurse manually. */
if (num_children == 1) {
p = p->children[0];
goto top;
}
for (size_t i = 0; i < num_children; i++)
/* In other words: if any child is unfinished,
* we are unfinished. */
if (!payment_is_finished(p->children[i]))
return false;
return true;
} else {
return false;
}
}
static enum payment_step payment_aggregate_states(struct payment *p)
{
enum payment_step agg = p->step;
for (size_t i=0; i<tal_count(p->children); i++)
agg |= payment_aggregate_states(p->children[i]);
return agg;
}
/* A payment is finished if a) it is in a final state, of b) it's in a
* child-spawning state and all of its children are in a final state. */
static bool payment_is_success(struct payment *p)
{
return (payment_aggregate_states(p) & PAYMENT_STEP_SUCCESS) != 0;
}
/* Function to bubble up completions to the root, which actually holds on to
* the command that initiated the flow. */
static void payment_child_finished(struct payment *p,
struct payment *child)
{
if (!payment_is_finished(p))
return;
/* Should we continue bubbling up? */
payment_finished(p);
}
static void payment_add_attempt(struct json_stream *s, const char *fieldname, struct payment *p, bool recurse)
{
bool finished = p->step >= PAYMENT_STEP_RETRY,
success = p->step == PAYMENT_STEP_SUCCESS;
/* A fieldname is only reasonable if we're not recursing. Otherwise the
* fieldname would be reused for all attempts. */
assert(!recurse || fieldname == NULL);
json_object_start(s, fieldname);
if (!finished)
json_add_string(s, "status", "pending");
else if (success)
json_add_string(s, "status", "success");
else
json_add_string(s, "status", "failed");
if (p->failreason != NULL)
json_add_string(s, "failreason", p->failreason);
json_add_u64(s, "partid", p->partid);
json_add_amount_msat(s, "amount_msat", p->amount);
if (p->parent != NULL)
json_add_u64(s, "parent_partid", p->parent->partid);
json_object_end(s);
for (size_t i=0; i<tal_count(p->children); i++) {
payment_add_attempt(s, fieldname, p->children[i], recurse);
}
}
static void payment_json_add_attempts(struct json_stream *s,
const char *fieldname, struct payment *p)
{
assert(p == payment_root(p));
json_array_start(s, fieldname);
payment_add_attempt(s, NULL, p, true);
json_array_end(s);
}
static void payment_notify_failure(struct payment *p, const char *error_message)
{
struct payment *root = payment_root(p);
struct json_stream *n;
n = plugin_notification_start(p->plugin, "pay_failure");
json_add_sha256(n, "payment_hash", p->payment_hash);
if (root->invstring != NULL)
json_add_string(n, "bolt11", root->invstring);
json_object_start(n, "error");
json_add_string(n, "message", error_message);
json_object_end(n); /* .error */
plugin_notification_end(p->plugin, n);
}
/* Code shared by selfpay fast-path: populate JSON output for successful
* payment, and send pay_success notification. */
void json_add_payment_success(struct json_stream *js,
struct payment *p,
const struct preimage *preimage,
const struct payment_tree_result *result)
{
struct json_stream *n;
struct payment *root = payment_root(p);
json_add_node_id(js, "destination", p->destination);
json_add_sha256(js, "payment_hash", p->payment_hash);
json_add_timeabs(js, "created_at", p->start_time);
if (result)
json_add_num(js, "parts", result->attempts);
else
json_add_num(js, "parts", 1);
json_add_amount_msat(js, "amount_msat", p->amount);
if (result)
json_add_amount_msat(js, "amount_sent_msat", result->sent);
else
json_add_amount_msat(js, "amount_sent_msat", p->amount);
if (result && result->leafstates != PAYMENT_STEP_SUCCESS)
json_add_string(js, "warning_partial_completion",
"Some parts of the payment are not yet "
"completed, but we have the confirmation "
"from the recipient.");
json_add_preimage(js, "payment_preimage", preimage);
json_add_string(js, "status", "complete");
n = plugin_notification_start(p->plugin, "pay_success");
json_add_sha256(n, "payment_hash", p->payment_hash);
if (root->invstring != NULL)
json_add_string(n, "bolt11", root->invstring);
plugin_notification_end(p->plugin, n);
}
/* This function is called whenever a payment ends up in a final state, or all
* leafs in the subtree rooted in the payment are all in a final state. It is
* called only once, and it is guaranteed to be called in post-order
* traversal, i.e., all children are finished before the parent is called. */
static void payment_finished(struct payment *p)
{
struct payment_tree_result result = payment_collect_result(p);
struct json_stream *ret;
struct command *cmd = p->cmd;
const char *msg;
/* Either none of the leaf attempts succeeded yet, or we have a
* preimage. */
assert((result.leafstates & PAYMENT_STEP_SUCCESS) == 0 ||
result.preimage != NULL);
if (p->parent == NULL) {
/* We are about to reply, unset the pointer to the cmd so we
* don't attempt to return a response twice. */
p->cmd = NULL;
if (cmd == NULL) {
/* This is the tree root, but we already reported
* success or failure, so noop. */
return;
} else if (payment_is_success(p)) {
assert(result.treestates & PAYMENT_STEP_SUCCESS);
assert(result.leafstates & PAYMENT_STEP_SUCCESS);
assert(result.preimage != NULL);
/* Call any callback we might have registered. */
if (p->on_payment_success != NULL)
p->on_payment_success(p);
ret = jsonrpc_stream_success(cmd);
json_add_payment_success(ret, p, result.preimage,
&result);
if (command_finished(cmd, ret)) {/* Ignore result. */}
p->cmd = NULL;
return;
} else if (p->aborterror != NULL) {
/* We set an explicit toplevel error message,
* so let's report that. */
ret = jsonrpc_stream_fail(cmd, PAY_STOPPED_RETRYING,
p->aborterror);
payment_json_add_attempts(ret, "attempts", p);
payment_notify_failure(p, p->aborterror);
if (command_finished(cmd, ret)) {/* Ignore result. */}
p->cmd = NULL;
return;
} else if (result.failure == NULL || result.failure->failcode < NODE) {
if (p->on_payment_failure != NULL)
p->on_payment_failure(p);
/* This is failing because we have no more routes to try */
msg = tal_fmt(cmd,
"Ran out of routes to try after "
"%d attempt%s: see `paystatus`",
result.attempts,
result.attempts == 1 ? "" : "s");
ret = jsonrpc_stream_fail(cmd, PAY_STOPPED_RETRYING,
msg);
payment_json_add_attempts(ret, "attempts", p);
payment_notify_failure(p, msg);
if (command_finished(cmd, ret)) {/* Ignore result. */}
p->cmd = NULL;
return;
} else {
struct payment_result *failure = result.failure;
assert(failure!= NULL);
if (p->on_payment_failure != NULL)
p->on_payment_failure(p);
ret = jsonrpc_stream_fail(cmd, failure->code,
failure->message);
json_add_u64(ret, "id", failure->id);
json_add_u32(ret, "failcode", failure->failcode);
json_add_string(ret, "failcodename",
failure->failcodename);
if (p->invstring)
json_add_invstring(ret, p->invstring);
json_add_hex_talarr(ret, "raw_message",
result.failure->raw_message);
json_add_num(ret, "created_at", p->start_time.ts.tv_sec);
json_add_node_id(ret, "destination", p->destination);
json_add_sha256(ret, "payment_hash", p->payment_hash);
if (result.leafstates & PAYMENT_STEP_SUCCESS) {
/* If one sub-payment succeeded then we have
* proof of payment, and the payment is a
* success. */
json_add_string(ret, "status", "complete");
} else if (result.leafstates & ~PAYMENT_STEP_FAILED) {
/* If there are non-failed leafs we are still trying. */
json_add_string(ret, "status", "pending");
} else {
json_add_string(ret, "status", "failed");
}
json_add_amount_msat(ret, "amount_msat", p->amount);
json_add_amount_msat(ret, "amount_sent_msat",
result.sent);
if (failure != NULL) {
if (failure->erring_index)
json_add_num(ret, "erring_index",
*failure->erring_index);
if (failure->erring_node)
json_add_node_id(ret, "erring_node",
failure->erring_node);
if (failure->erring_channel)
json_add_short_channel_id(
ret, "erring_channel",
failure->erring_channel);
if (failure->erring_direction)
json_add_num(
ret, "erring_direction",
*failure->erring_direction);
}
payment_notify_failure(p, failure->message);
if (command_finished(cmd, ret)) { /* Ignore result. */}
p->cmd = NULL;
return;
}
} else {
payment_child_finished(p->parent, p);
return;
}
}
void payment_set_step(struct payment *p, enum payment_step newstep)
{
p->current_modifier = -1;
p->step = newstep;
/* Any final state needs an end_time */
if (p->step >= PAYMENT_STEP_SPLIT)
p->end_time = time_now();
}
void payment_continue(struct payment *p)
{
struct payment_modifier *mod;
void *moddata;
/* If we are in the middle of calling the modifiers, continue calling
* them, otherwise we can continue with the payment state-machine. */
p->current_modifier++;
mod = p->modifiers[p->current_modifier];
if (mod != NULL) {
/* There is another modifier, so call it. */
moddata = p->modifier_data[p->current_modifier];
return mod->post_step_cb(moddata, p);
} else {
/* There are no more modifiers, so reset the call chain and
* proceed to the next state. */
p->current_modifier = -1;
switch (p->step) {
case PAYMENT_STEP_INITIALIZED:
case PAYMENT_STEP_RETRY_GETROUTE:
payment_getroute(p);
return;
case PAYMENT_STEP_GOT_ROUTE:
payment_compute_onion_payloads(p);
return;
case PAYMENT_STEP_ONION_PAYLOAD:
payment_sendonion(p);
return;
case PAYMENT_STEP_SUCCESS:
case PAYMENT_STEP_FAILED:
payment_finished(p);
return;
case PAYMENT_STEP_RETRY:
case PAYMENT_STEP_SPLIT:
/* Do nothing, we'll get pinged by a child succeeding
* or failing. */
return;
}
}
/* We should never get here, it'd mean one of the state machine called
* `payment_continue` after the final state. */
abort();
}
void payment_abort(struct payment *p, const char *fmt, ...) {
va_list ap;
struct payment *root = payment_root(p);
payment_set_step(p, PAYMENT_STEP_FAILED);
p->end_time = time_now();
/* We can fail twice, it seems. */
tal_free(p->failreason);
va_start(ap, fmt);
p->failreason = tal_vfmt(p, fmt, ap);
va_end(ap);
root->abort = true;
/* Only set the abort error if it's not yet set, otherwise we
* might end up clobbering the earliest and decisive failure
* with less relevant ones. */
if (root->aborterror == NULL)
root->aborterror = tal_dup_talarr(root, char, p->failreason);
paymod_log(p, LOG_INFORM, "%s", p->failreason);
/* Do not use payment_continue, because that'd continue
* applying the modifiers before calling
* payment_finished(). */
payment_finished(p);
}
void payment_fail(struct payment *p, const char *fmt, ...)
{
va_list ap;
p->end_time = time_now();
payment_set_step(p, PAYMENT_STEP_FAILED);
/* We can fail twice, it seems. */
tal_free(p->failreason);
va_start(ap, fmt);
p->failreason = tal_vfmt(p, fmt, ap);
va_end(ap);
paymod_log(p, LOG_INFORM, "%s", p->failreason);
payment_continue(p);
}
void *payment_mod_get_data(const struct payment *p,
const struct payment_modifier *mod)
{
for (size_t i = 0; p->modifiers[i] != NULL; i++)
if (p->modifiers[i] == mod)
return p->modifier_data[i];
/* If we ever get here it means that we asked for the data for a
* non-existent modifier. This is a compile-time/wiring issue, so we
* better check that modifiers match the data we ask for. */
abort();
}
static struct retry_mod_data *retry_data_init(struct payment *p);
static inline void retry_step_cb(struct retry_mod_data *rd,
struct payment *p);
static struct retry_mod_data *
retry_data_init(struct payment *p)
{
struct retry_mod_data *rdata = tal(p, struct retry_mod_data);
struct retry_mod_data *parent_rdata;
/* We start the retry counter from scratch for the root payment, or if
* the parent was split, meaning this is a new attempt with new
* amounts. */
if (p->parent == NULL || p->parent->step == PAYMENT_STEP_SPLIT) {
rdata->retries = 10;
} else {
parent_rdata = payment_mod_retry_get_data(p->parent);
rdata->retries = parent_rdata->retries - 1;
}
return rdata;
}
/* Determine whether retrying could possibly succeed. Retrying in this case
* means that we repeat the entire flow, including computing a new route, new
* payload and a new sendonion call. It does not mean we retry the exact same
* attempt that just failed. */
static bool payment_can_retry(struct payment *p)
{
struct payment_result *res = p->result;
u32 idx;
bool is_final;
if (p->result == NULL)
return p->failroute_retry;
idx = res->erring_index != NULL ? *res->erring_index : 0;
is_final = (idx == tal_count(p->route));
/* Full matrix of failure code x is_final. Prefer to retry once too
* often over eagerly failing. */
switch (res->failcode) {
case WIRE_EXPIRY_TOO_FAR:
case WIRE_INCORRECT_OR_UNKNOWN_PAYMENT_DETAILS:
case WIRE_INVALID_ONION_PAYLOAD:
case WIRE_INVALID_ONION_VERSION:
case WIRE_INVALID_REALM:
case WIRE_MPP_TIMEOUT:
case WIRE_PERMANENT_NODE_FAILURE:
case WIRE_REQUIRED_NODE_FEATURE_MISSING:
case WIRE_TEMPORARY_NODE_FAILURE:
case WIRE_UNKNOWN_NEXT_PEER:
return !is_final;
case WIRE_AMOUNT_BELOW_MINIMUM:
case WIRE_CHANNEL_DISABLED:
case WIRE_EXPIRY_TOO_SOON:
case WIRE_FEE_INSUFFICIENT:
case WIRE_FINAL_INCORRECT_CLTV_EXPIRY:
case WIRE_FINAL_INCORRECT_HTLC_AMOUNT:
case WIRE_INCORRECT_CLTV_EXPIRY:
case WIRE_INVALID_ONION_HMAC:
case WIRE_INVALID_ONION_KEY:
case WIRE_PERMANENT_CHANNEL_FAILURE:
case WIRE_REQUIRED_CHANNEL_FEATURE_MISSING:
case WIRE_TEMPORARY_CHANNEL_FAILURE:
case WIRE_INVALID_ONION_BLINDING:
return true;
}
/* We should never get here, otherwise the above `switch` isn't
* exhaustive. Nevertheless the failcode is provided by the erring
* node, so retry anyway. `abort()`ing on externally supplied info is
* not a good idea. */
return true;
}
static inline void retry_step_cb(struct retry_mod_data *rd,
struct payment *p)
{
struct payment *subpayment, *root = payment_root(p);
struct retry_mod_data *rdata = payment_mod_retry_get_data(p);
struct timeabs now = time_now();
if (p->step != PAYMENT_STEP_FAILED)
return payment_continue(p);
if (time_after(now, p->deadline)) {
paymod_log(
p, LOG_INFORM,
"Payment deadline expired, not retrying (partial-)payment "
"%s/%d",
type_to_string(tmpctx, struct sha256, p->payment_hash),
p->partid);
root->abort = true;
return payment_continue(p);
}
/* If we failed to find a route, it's unlikely we can suddenly find a
* new one without any other changes, so it's time to give up. */
if (p->route == NULL && !p->failroute_retry)
return payment_continue(p);
/* If the root is marked as abort, we do not retry anymore */
if (payment_root(p)->abort)
return payment_continue(p);
if (!payment_can_retry(p))
return payment_continue(p);
/* If the failure was not final, and we tried a route, try again. */
if (rdata->retries > 0) {
payment_set_step(p, PAYMENT_STEP_RETRY);
subpayment = payment_new(p, NULL, p, p->modifiers);
payment_start(subpayment);
subpayment->why =
tal_fmt(subpayment, "Still have %d attempts left",
rdata->retries - 1);
paymod_log(
p, LOG_DBG,
"Retrying %s/%d (%s), new partid %d. %d attempts left\n",
type_to_string(tmpctx, struct sha256, p->payment_hash),
p->partid,
type_to_string(tmpctx, struct amount_msat, &p->amount),
subpayment->partid,
rdata->retries - 1);
}
payment_continue(p);
}
REGISTER_PAYMENT_MODIFIER(retry, struct retry_mod_data *, retry_data_init,
retry_step_cb);
static struct command_result *
local_channel_hints_listpeerchannels(struct command *cmd, const char *buffer,
const jsmntok_t *toks, struct payment *p)
{
struct listpeers_channel **chans;
chans = json_to_listpeers_channels(tmpctx, buffer, toks);
for (size_t i = 0; i < tal_count(chans); i++) {
bool enabled;
u16 htlc_budget;
/* Filter out local channels if they are
* either a) disconnected, or b) not in normal
* state. */
enabled = chans[i]->connected
&& (streq(chans[i]->state, "CHANNELD_NORMAL")
|| streq(chans[i]->state, "CHANNELD_AWAITING_SPLICE"));
/* Take the configured number of max_htlcs and
* subtract any HTLCs that might already be added to
* the channel. This is a best effort estimate and
* mostly considers stuck htlcs, concurrent payments
* may throw us off a bit. */
if (chans[i]->num_htlcs > chans[i]->max_accepted_htlcs)
htlc_budget = 0;
else
htlc_budget = chans[i]->max_accepted_htlcs - chans[i]->num_htlcs;
/* If we have both a scid and a local alias we want to
* use the scid, and mark the alias as
* unusable. Otherwise `getroute` might return the
* alias, which we resolve correctly, but our
* channel_hints would be off after updates, since
* we'd only ever update one of the aliases. Causing
* the other to be considered usable.
*/
if (chans[i]->scid != NULL) {
channel_hints_update(
p, *chans[i]->scid, chans[i]->direction, enabled,
true, &chans[i]->spendable_msat, &htlc_budget);
if (chans[i]->alias[LOCAL] != NULL)
channel_hints_update(p, *chans[i]->alias[LOCAL],
chans[i]->direction,
false /* not enabled */,
true, &AMOUNT_MSAT(0),
&htlc_budget);
} else {
channel_hints_update(p, *chans[i]->alias[LOCAL],
chans[i]->direction, enabled, true,
&chans[i]->spendable_msat,
&htlc_budget);
}
}
payment_continue(p);
return command_still_pending(cmd);
}
static void local_channel_hints_cb(void *d UNUSED, struct payment *p)
{
struct out_req *req;
/* If we are not the root we don't look up the channel balances since
* it is unlikely that the capacities have changed much since the root
* payment looked at them. We also only call `listpeers` when the
* payment is in state PAYMENT_STEP_INITIALIZED, right before calling
* `getroute`. */
if (p->parent != NULL || p->step != PAYMENT_STEP_INITIALIZED)
return payment_continue(p);
req = jsonrpc_request_start(p->plugin, NULL, "listpeerchannels",
local_channel_hints_listpeerchannels,
local_channel_hints_listpeerchannels, p);
send_outreq(p->plugin, req);
}
REGISTER_PAYMENT_MODIFIER(local_channel_hints, void *, NULL, local_channel_hints_cb);
/* Trim route to this length by taking from the *front* of route
* (end points to destination, so we need that bit!) */
static void trim_route(struct route_info **route, size_t n)
{
size_t remove = tal_count(*route) - n;
memmove(*route, *route + remove, sizeof(**route) * n);
tal_resize(route, n);
}
/* Make sure routehints are reasonable length, and (since we assume we
* can append), not directly to us. Note: untrusted data! */
static struct route_info **filter_routehints(struct gossmap *map,
struct payment *p,
struct routehints_data *d,
struct node_id *myid,
struct route_info **hints)
{
const size_t max_hops = ROUTING_MAX_HOPS / 2;
char *mods = tal_strdup(tmpctx, "");
struct gossmap_node *src = gossmap_find_node(map, p->local_id);
if (src == NULL) {
tal_append_fmt(&mods,
"Could not locate ourselves in the gossip map, "
"leaving routehints untouched. ");
}
for (size_t i = 0; i < tal_count(hints) && src != NULL; i++) {
struct gossmap_node *entrynode;
u32 distance;
/* Trim any routehint > 10 hops */
if (tal_count(hints[i]) > max_hops) {
tal_append_fmt(&mods,
"Trimmed routehint %zu (%zu hops) to %zu. ",
i, tal_count(hints[i]), max_hops);
trim_route(&hints[i], max_hops);
}
/* If we are first hop, trim. */
if (tal_count(hints[i]) > 0
&& node_id_eq(&hints[i][0].pubkey, myid)) {
tal_append_fmt(&mods,
"Removed ourselves from routehint %zu. ",
i);
trim_route(&hints[i], tal_count(hints[i])-1);
}
/* If route is empty, remove altogether. */
if (tal_count(hints[i]) == 0) {
tal_append_fmt(&mods,
"Removed empty routehint %zu. ", i);
tal_arr_remove(&hints, i);
i--;
continue;
}
/* If routehint entrypoint is unreachable there's no
* point in keeping it. */
entrynode = gossmap_find_node(map, &hints[i][0].pubkey);
if (entrynode == NULL) {
tal_append_fmt(&mods,
"Removed routehint %zu because "
"entrypoint %s is unknown. ",
i,
type_to_string(tmpctx, struct node_id,
&hints[i][0].pubkey));
plugin_log(p->plugin, LOG_DBG,
"Removed routehint %zu because "
"entrypoint %s is unknown. ",
i,
type_to_string(tmpctx, struct node_id,
&hints[i][0].pubkey));
tal_arr_remove(&hints, i);
i--;
continue;
}
distance = dijkstra_distance(
dijkstra(tmpctx, map, entrynode, AMOUNT_MSAT(0), 1,
payment_route_can_carry_even_disabled,
route_score_cheaper, p),
gossmap_node_idx(map, src));
if (distance == UINT_MAX) {
tal_append_fmt(&mods,
"Removed routehint %zu because "
"entrypoint %s is unreachable. ",
i,
type_to_string(tmpctx, struct node_id,
&hints[i][0].pubkey));
plugin_log(p->plugin, LOG_DBG,
"Removed routehint %zu because "
"entrypoint %s is unreachable. ",
i,
type_to_string(tmpctx, struct node_id,
&hints[i][0].pubkey));
tal_arr_remove(&hints, i);
i--;
}
}
if (!streq(mods, ""))
d->routehint_modifications = tal_steal(d, mods);
return tal_steal(d, hints);
}
static bool route_msatoshi(struct amount_msat *total,
const struct amount_msat msat,
const struct route_info *route, size_t num_route);
static bool routehint_excluded(struct payment *p,
const struct route_info *routehint)
{
const struct node_id *nodes = payment_get_excluded_nodes(tmpctx, p);
const struct short_channel_id_dir *chans =
payment_get_excluded_channels(tmpctx, p);
const struct channel_hint *hints = payment_root(p)->channel_hints;
/* Note that we ignore direction here: in theory, we could have
* found that one direction of a channel is unavailable, but they
* are suggesting we use it the other way. Very unlikely though! */
for (size_t i = 0; i < tal_count(routehint); i++) {
const struct route_info *r = &routehint[i];
for (size_t j = 0; j < tal_count(nodes); j++)
if (node_id_eq(&r->pubkey, &nodes[j]))
return true;
for (size_t j = 0; j < tal_count(chans); j++)
if (short_channel_id_eq(&chans[j].scid, &r->short_channel_id))
return true;
/* Skip the capacity check if this is the last hop
* in the routehint.
* The last hop in the routehint delivers the exact
* final amount to the destination, which
* payment_get_excluded_channels uses for excluding
* already.
* Thus, the capacity check below only really matters
* for multi-hop routehints.
*/
if (i == tal_count(routehint) - 1)
continue;
/* Check our capacity fits. */
struct amount_msat needed_capacity;
if (!route_msatoshi(&needed_capacity, p->amount,
r + 1, tal_count(routehint) - i - 1))
return true;
/* Why do we scan the hints again if
* payment_get_excluded_channels already does?
* Because payment_get_excluded_channels checks the
* amount at destination, but we know that we are
* a specific distance from the destination and we
* know the exact capacity we need to send via this
* channel, which is greater than the destination.
*/
for (size_t j = 0; j < tal_count(hints); j++) {
if (!short_channel_id_eq(&hints[j].scid.scid, &r->short_channel_id))
continue;
/* We exclude on equality because we set the estimate
* to the smallest failed attempt. */
if (amount_msat_greater_eq(needed_capacity,
hints[j].estimated_capacity))
return true;
}
}
return false;
}
static struct route_info *next_routehint(struct routehints_data *d,
struct payment *p)
{
size_t numhints = tal_count(d->routehints);
struct route_info *curr;
if (d->routehints == NULL || numhints == 0)
return NULL;
/* BOLT #11:
*
* - if a writer offers more than one of any field type, it:
* - MUST specify the most-preferred field first, followed
* by less-preferred fields, in order.
*/
for (; d->offset < numhints; d->offset++) {
curr = d->routehints[(d->base + d->offset) % numhints];
if (curr == NULL || !routehint_excluded(p, curr))
return curr;
}
return NULL;
}
/* Calculate how many millisatoshi we need at the start of this route
* to get msatoshi to the end. */
static bool route_msatoshi(struct amount_msat *total,
const struct amount_msat msat,
const struct route_info *route, size_t num_route)
{
*total = msat;
for (ssize_t i = num_route - 1; i >= 0; i--) {
if (!amount_msat_add_fee(total,
route[i].fee_base_msat,
route[i].fee_proportional_millionths))
return false;
}
return true;
}
/* The pubkey to use is the destination of this routehint. */
static const struct node_id *route_pubkey(const struct payment *p,
const struct route_info *routehint,
size_t n)
{
if (n == tal_count(routehint))
return p->destination;
return &routehint[n].pubkey;
}
static u32 route_cltv(u32 cltv,
const struct route_info *route, size_t num_route)
{
for (size_t i = 0; i < num_route; i++)
cltv += route[i].cltv_expiry_delta;
return cltv;
}
/** routehint_generate_exclusion_list
*
* @brief generate a list of items to append to `excludes`
* parameter of `getroute`.
*
* @param ctx - the context to allocate off of.
* @param routehint - the actual routehint, a `tal` array.
* @param payment - the payment that we will create an
* exclusion list for.
*
* @return an array of strings that will be appended to the
* `excludes` parameter of `getroute`.
*/
static
struct node_id *routehint_generate_exclusion_list(const tal_t *ctx,
struct route_info *routehint,
struct payment *payment)
{
struct node_id *exc;
if (!routehint || tal_count(routehint) == 0)
/* Nothing to exclude. */
return NULL;
exc = tal_arr(ctx, struct node_id, tal_count(routehint));
/* Exclude every node except the first, because the first is
* the entry point to the routehint. */
for (size_t i = 1 /* Skip the first! */; i < tal_count(routehint); ++i)
exc[i-1] = routehint[i].pubkey;
/* Also exclude the destination, because it would be foolish to
* pass through it and *then* go to the routehint entry point. */
exc[tal_count(routehint)-1] = *payment->destination;
return exc;
}
/* Change the destination and compute the final msatoshi amount to send to the
* routehint entry point. */
static void routehint_pre_getroute(struct routehints_data *d, struct payment *p)
{
bool have_more;
d->current_routehint = next_routehint(d, p);
/* Signal that we could retry with another routehint even if getroute
* fails. */
have_more = (d->offset < tal_count(d->routehints) - 1);
p->failroute_retry = have_more;
p->temp_exclusion = tal_free(p->temp_exclusion);
if (d->current_routehint != NULL) {
if (!route_msatoshi(&p->getroute->amount, p->amount,
d->current_routehint,
tal_count(d->current_routehint))) {
}
d->final_cltv = p->getroute->cltv;
p->getroute->destination = &d->current_routehint[0].pubkey;
p->getroute->cltv =
route_cltv(p->getroute->cltv, d->current_routehint,
tal_count(d->current_routehint));
paymod_log(
p, LOG_DBG, "Using routehint %s (%s) cltv_delta=%d",
type_to_string(tmpctx, struct node_id,
&d->current_routehint->pubkey),
type_to_string(tmpctx, struct short_channel_id,
&d->current_routehint->short_channel_id),
d->current_routehint->cltv_expiry_delta);
/* Exclude the entrypoint to the routehint, so we don't end up
* going through the destination to the entrypoint. */
p->temp_exclusion = routehint_generate_exclusion_list(p, d->current_routehint, p);
} else
paymod_log(p, LOG_DBG, "Not using a routehint");
}
static void routehint_check_reachable(struct payment *p)
{
const struct gossmap_node *dst, *src;
struct gossmap *gossmap = get_gossmap(p->plugin);
const struct dijkstra *dij;
struct route_hop *r;
struct payment *root = payment_root(p);
struct routehints_data *d = payment_mod_routehints_get_data(root);
/* Start a tiny exploratory route computation, so we know
* whether we stand any chance of reaching the destination
* without routehints. This will later be used to mix in
* attempts without routehints. */
src = gossmap_find_node(gossmap, p->local_id);
dst = gossmap_find_node(gossmap, p->destination);
if (dst == NULL)
d->destination_reachable = false;
else if (src != NULL) {
dij = dijkstra(tmpctx, gossmap, dst, AMOUNT_MSAT(0),
10 / 1000000.0,
payment_route_can_carry_even_disabled,
route_score_cheaper, p);
r = route_from_dijkstra(tmpctx, gossmap, dij, src,
AMOUNT_MSAT(0), 0);
/* If there was a route the destination is reachable
* without routehints. */
d->destination_reachable = r != NULL;
} else {
paymod_log(p, LOG_DBG,
"Could not locate ourselves in the network. "
"Allowing direct attempts");
d->destination_reachable = true;
}
if (d->destination_reachable) {
tal_arr_expand(&d->routehints, NULL);
/* The above could trigger a realloc.
* However, p->routes and d->routehints are
* actually the same array, so we need to update the
* p->routes pointer, since the realloc
* might have changed pointer addresses, in order to
* ensure that the pointers are not stale.
*/
p->routes = d->routehints;
/* FIXME: ***DO*** we need to add this extra routehint?
* Once we run out of routehints the default system will
* just attempt directly routing to the destination anyway. */
} else if (tal_count(d->routehints) == 0) {
/* If we don't have any routehints and the destination
* isn't reachable, then there is no point in
* continuing. */
payment_abort(
p,
"Destination %s is not reachable directly and "
"all routehints were unusable.",
type_to_string(tmpctx, struct node_id, p->destination));
return;
}
routehint_pre_getroute(d, p);
paymod_log(p, LOG_DBG,
"The destination is%s directly reachable %s attempts "
"without routehints",
d->destination_reachable ? "" : " not",
d->destination_reachable ? "including" : "excluding");
/* Now we can continue on our merry way. */
payment_continue(p);
}
static void routehint_step_cb(struct routehints_data *d, struct payment *p)
{
struct route_hop hop;
const struct payment *root = payment_root(p);
struct gossmap *map;
if (p->step == PAYMENT_STEP_INITIALIZED) {
if (root->routes == NULL)
return payment_continue(p);
/* We filter out non-functional routehints once at the
* beginning, and every other payment will filter out the
* exluded ones on the fly. */
if (p->parent == NULL) {
map = get_gossmap(p->plugin);
d->routehints = filter_routehints(
map, p, d, p->local_id, p->routes);
/* filter_routehints modifies the array, but
* this could trigger a resize and the resize
* could trigger a realloc.
* Keep the invoice pointer up-to-date.
* FIXME: We should really consider that if we are
* mutating p->routes, maybe we should
* drop d->routehints and just use p->routes
* directly.
* It is probably not a good idea to *copy* the
* routehints: other paymods are interested in
* p->routes, and if the routehints system
* itself adds or removes routehints from its
* copy, the *actual* number of routehints that we
* end up using is the one that the routehints paymod
* is maintaining and traversing, and it is *that*
* set of routehints that is the important one.
* So rather than copying the array of routehints
* in paymod, paymod should use (and mutate) the
* p->routes array, and
*/
p->routes = d->routehints;
paymod_log(p, LOG_DBG,
"After filtering routehints we're left with "
"%zu usable hints",
tal_count(d->routehints));
/* Do not continue normally, instead go and check if
* we can reach the destination directly. */
return routehint_check_reachable(p);
}
routehint_pre_getroute(d, p);
} else if (p->step == PAYMENT_STEP_GOT_ROUTE && d->current_routehint != NULL) {
/* Now it's time to stitch the two partial routes together. */
struct amount_msat dest_amount;
struct route_info *routehint = d->current_routehint;
struct route_hop *prev_hop;
for (ssize_t i = 0; i < tal_count(routehint); i++) {
prev_hop = &p->route[tal_count(p->route)-1];
if (!route_msatoshi(&dest_amount, p->amount,
routehint + i + 1,
tal_count(routehint) - i - 1)) {
/* Just let it fail, since we couldn't stitch
* the routes together. */
return payment_continue(p);
}
hop.node_id = *route_pubkey(p, routehint, i + 1);
hop.scid = routehint[i].short_channel_id;
hop.amount = dest_amount;
hop.delay = route_cltv(d->final_cltv, routehint + i + 1,
tal_count(routehint) - i - 1);
/* Should we get a failure inside the routehint we'll
* need the direction so we can exclude it. Luckily
* it's rather easy to compute given the two
* subsequent hops. */
hop.direction =
node_id_cmp(&prev_hop->node_id, &hop.node_id) > 0 ? 1
: 0;
tal_arr_expand(&p->route, hop);
}
}
payment_continue(p);
}
static struct routehints_data *routehint_data_init(struct payment *p)
{
struct routehints_data *pd, *d = tal(p, struct routehints_data);
/* If for some reason we skipped the getroute call (directpay) we'll
* need this to be initialized. */
d->current_routehint = NULL;
if (p->parent != NULL) {
pd = payment_mod_routehints_get_data(payment_root(p));
d->destination_reachable = pd->destination_reachable;
d->routehints = pd->routehints;
pd = payment_mod_routehints_get_data(p->parent);
if (p->parent->step == PAYMENT_STEP_RETRY) {
d->base = pd->base;
d->offset = pd->offset;
/* If the previous try failed to route, advance
* to the next routehint. */
if (!p->parent->route)
++d->offset;
} else {
size_t num_routehints = tal_count(d->routehints);
d->offset = 0;
/* This used to be pseudorand.
*
* However, it turns out that using the partid for
* this payment has some nice properties.
* The partid is in general quite random, due to
* getting entropy from the network on the timing
* of when payments complete/fail, and the routehint
* randomization is not a privacy or security feature,
* only a reliability one, thus does not need a lot
* of entropy.
*
* But the most important bit is that *splits
* get contiguous partids*, e.g. an adaptive
* split will get two consecutive partid.
* Because of the contiguity, using the partid
* for the base will cause the split-up
* payments to have fairly diverse initial
* routehints.
*/
if (num_routehints == 0)
d->base = 0;
else
d->base = (p->partid - 1) % num_routehints;
}
return d;
} else {
/* We defer the actual initialization of the routehints array to
* the step callback when we have the invoice attached. */
d->routehints = NULL;
d->base = 0;
d->offset = 0;
d->destination_reachable = false;
return d;
}
return d;
}
REGISTER_PAYMENT_MODIFIER(routehints, struct routehints_data *,
routehint_data_init, routehint_step_cb);
/* For tiny payments the fees incurred due to the fixed base_fee may dominate
* the overall cost of the payment. Since these payments are often used as a
* way to signal, rather than actually transfer the amount, we add an
* exemption that allows tiny payments to exceed the fee allowance. This is
* implemented by setting a larger allowance than we would normally do if the
* payment is below the threshold. */
static struct exemptfee_data *exemptfee_data_init(struct payment *p)
{
if (p->parent == NULL) {
struct exemptfee_data *d = tal(p, struct exemptfee_data);
d->amount = AMOUNT_MSAT(5000);
return d;
} else {
return payment_mod_exemptfee_get_data(p->parent);
}
}
static void exemptfee_cb(struct exemptfee_data *d, struct payment *p)
{
if (p->step != PAYMENT_STEP_INITIALIZED || p->parent != NULL)
return payment_continue(p);
if (amount_msat_greater_eq(d->amount, p->constraints.fee_budget)) {
paymod_log(
p, LOG_INFORM,
"Payment fee constraint %s is below exemption threshold, "
"allowing a maximum fee of %s",
type_to_string(tmpctx, struct amount_msat, &p->constraints.fee_budget),
type_to_string(tmpctx, struct amount_msat, &d->amount));
p->constraints.fee_budget = d->amount;
p->start_constraints->fee_budget = d->amount;
}
return payment_continue(p);
}
REGISTER_PAYMENT_MODIFIER(exemptfee, struct exemptfee_data *,
exemptfee_data_init, exemptfee_cb);
/* BOLT #7:
*
* If a route is computed by simply routing to the intended recipient and
* summing the `cltv_expiry_delta`s, then it's possible for intermediate nodes
* to guess their position in the route. Knowing the CLTV of the HTLC, the
* surrounding network topology, and the `cltv_expiry_delta`s gives an
* attacker a way to guess the intended recipient. Therefore, it's highly
* desirable to add a random offset to the CLTV that the intended recipient
* will receive, which bumps all CLTVs along the route.
*
* In order to create a plausible offset, the origin node MAY start a limited
* random walk on the graph, starting from the intended recipient and summing
* the `cltv_expiry_delta`s, and use the resulting sum as the offset. This
* effectively creates a _shadow route extension_ to the actual route and
* provides better protection against this attack vector than simply picking a
* random offset would.
*/
static struct shadow_route_data *shadow_route_init(struct payment *p)
{
struct shadow_route_data *d = tal(p, struct shadow_route_data), *pd;
/* If we're not the root we need to inherit the flags set only on the
* root payment. Since we inherit them at each step it's sufficient to
* do so from our direct parent. */
if (p->parent != NULL) {
pd = payment_mod_shadowroute_get_data(p->parent);
d->fuzz_amount = pd->fuzz_amount;
d->use_shadow = pd->use_shadow;
} else {
d->fuzz_amount = true;
}
return d;
}
/* Mutual recursion */
static struct command_result *shadow_route_listchannels(struct command *cmd,
const char *buf,
const jsmntok_t *result,
struct payment *p);
static struct command_result *shadow_route_extend(struct shadow_route_data *d,
struct payment *p)
{
struct out_req *req;
req = jsonrpc_request_start(p->plugin, NULL, "listchannels",
shadow_route_listchannels,
payment_rpc_failure, p);
json_add_node_id(req->js, "source", &d->destination);
return send_outreq(p->plugin, req);
}
static struct command_result *shadow_route_listchannels(struct command *cmd,
const char *buf,
const jsmntok_t *result,
struct payment *p)
{
struct shadow_route_data *d = payment_mod_shadowroute_get_data(p);
struct payment_constraints *cons = &d->constraints;
struct route_info *best = NULL;
double total_weight = 0.0;
size_t i;
struct amount_msat best_fee;
const jsmntok_t *sattok, *delaytok, *basefeetok, *propfeetok, *desttok,
*channelstok, *chan, *scidtok;
/* Check the invariants on the constraints between payment and modifier. */
assert(d->constraints.cltv_budget <= p->constraints.cltv_budget / 4);
assert(amount_msat_greater_eq(p->constraints.fee_budget,
d->constraints.fee_budget));
channelstok = json_get_member(buf, result, "channels");
json_for_each_arr(i, chan, channelstok) {
struct route_info curr;
struct amount_sat capacity;
struct amount_msat fee;
sattok = json_get_member(buf, chan, "satoshis");
delaytok = json_get_member(buf, chan, "delay");
basefeetok = json_get_member(buf, chan, "base_fee_millisatoshi");
propfeetok = json_get_member(buf, chan, "fee_per_millionth");
scidtok = json_get_member(buf, chan, "short_channel_id");
desttok = json_get_member(buf, chan, "destination");
if (sattok == NULL || delaytok == NULL ||
delaytok->type != JSMN_PRIMITIVE || basefeetok == NULL ||
basefeetok->type != JSMN_PRIMITIVE || propfeetok == NULL ||
propfeetok->type != JSMN_PRIMITIVE || desttok == NULL ||
scidtok == NULL)
continue;
json_to_u16(buf, delaytok, &curr.cltv_expiry_delta);
json_to_number(buf, basefeetok, &curr.fee_base_msat);
json_to_number(buf, propfeetok,
&curr.fee_proportional_millionths);
json_to_short_channel_id(buf, scidtok, &curr.short_channel_id);
json_to_sat(buf, sattok, &capacity);
json_to_node_id(buf, desttok, &curr.pubkey);
/* If the capacity is insufficient to pass the amount
* it's not a plausible extension. */
if (amount_msat_greater_sat(p->amount, capacity))
continue;
if (curr.cltv_expiry_delta > cons->cltv_budget)
continue;
if (!amount_msat_fee(
&fee, p->amount, curr.fee_base_msat,
curr.fee_proportional_millionths)) {
/* Fee computation failed... */
continue;
}
if (amount_msat_greater_eq(fee, cons->fee_budget))
continue;
if (random_select(1.0, &total_weight)) {
best = tal_dup(tmpctx, struct route_info, &curr);
best_fee = fee;
}
}
if (best != NULL) {
/* Check that we could apply the shadow route extension. Check
* against both the shadow route budget as well as the
* original payment's budget. */
if (best->cltv_expiry_delta > d->constraints.cltv_budget ||
best->cltv_expiry_delta > p->constraints.cltv_budget) {
best = NULL;
goto next;
}
/* Check the fee budget only if we didn't opt out, since
* testing against a virtual budget is not useful if we do not
* actually use it (it could give false positives and fail
* attempts that might have gone through, */
if (d->fuzz_amount &&
(amount_msat_greater(best_fee, d->constraints.fee_budget) ||
(amount_msat_greater(best_fee,
p->constraints.fee_budget)))) {
best = NULL;
goto next;
}
/* Now we can be sure that adding the shadow route will succeed */
paymod_log(
p, LOG_DBG,
"Adding shadow_route hop over channel %s: adding %s "
"in fees and %d CLTV delta",
type_to_string(tmpctx, struct short_channel_id,
&best->short_channel_id),
type_to_string(tmpctx, struct amount_msat, &best_fee),
best->cltv_expiry_delta);
d->destination = best->pubkey;
d->constraints.cltv_budget -= best->cltv_expiry_delta;
p->getroute->cltv += best->cltv_expiry_delta;
if (!d->fuzz_amount)
goto next;
/* Only try to apply the fee budget changes if we want to fuzz
* the amount. Virtual fees that we then don't deliver to the
* destination could otherwise cause the route to be too
* expensive, while really being ok. If any of these fail then
* the above checks are insufficient. */
if (!amount_msat_sub(&d->constraints.fee_budget,
d->constraints.fee_budget, best_fee) ||
!amount_msat_sub(&p->constraints.fee_budget,
p->constraints.fee_budget, best_fee))
paymod_err(p,
"Could not update fee constraints "
"for shadow route extension. "
"payment fee budget %s, modifier "
"fee budget %s, shadow fee to add %s",
type_to_string(tmpctx, struct amount_msat,
&p->constraints.fee_budget),
type_to_string(tmpctx, struct amount_msat,
&d->constraints.fee_budget),
type_to_string(tmpctx, struct amount_msat,
&best_fee));
}
next:
/* Now it's time to decide whether we want to extend or continue. */
if (best == NULL || pseudorand(2) == 0) {
payment_continue(p);
return command_still_pending(cmd);
} else {
return shadow_route_extend(d, p);
}
}
static void shadow_route_cb(struct shadow_route_data *d,
struct payment *p)
{
if (!d->use_shadow)
return payment_continue(p);
if (p->step != PAYMENT_STEP_INITIALIZED)
return payment_continue(p);
d->destination = *p->destination;
/* Allow shadowroutes to consume up to 1/4th of our budget. */
d->constraints.cltv_budget = p->constraints.cltv_budget / 4;
d->constraints.fee_budget
= amount_msat_div(p->constraints.fee_budget, 4);
if (pseudorand(2) == 0) {
return payment_continue(p);
} else {
shadow_route_extend(d, p);
}
}
REGISTER_PAYMENT_MODIFIER(shadowroute, struct shadow_route_data *,
shadow_route_init, shadow_route_cb);
static void direct_pay_override(struct payment *p) {
/* The root has performed the search for a direct channel. */
struct payment *root = payment_root(p);
struct direct_pay_data *d;
struct channel_hint *hint = NULL;
/* If we were unable to find a direct channel we don't need to do
* anything. */
d = payment_mod_directpay_get_data(root);
if (d->chan == NULL)
return payment_continue(p);
/* If we have a channel we need to make sure that it still has
* sufficient capacity. Look it up in the channel_hints. */
for (size_t i=0; i<tal_count(root->channel_hints); i++) {
struct short_channel_id_dir *cur = &root->channel_hints[i].scid;
if (short_channel_id_eq(&cur->scid, &d->chan->scid) &&
cur->dir == d->chan->dir) {
hint = &root->channel_hints[i];
break;
}
}
if (hint && hint->enabled &&
amount_msat_greater(hint->estimated_capacity, p->amount)) {
/* Now build a route that consists only of this single hop */
p->route = tal_arr(p, struct route_hop, 1);
p->route[0].amount = p->amount;
p->route[0].delay = p->getroute->cltv;
p->route[0].scid = hint->scid.scid;
p->route[0].direction = hint->scid.dir;
p->route[0].node_id = *p->destination;
paymod_log(p, LOG_DBG,
"Found a direct channel (%s) with sufficient "
"capacity, skipping route computation.",
type_to_string(tmpctx, struct short_channel_id_dir,
&hint->scid));
payment_set_step(p, PAYMENT_STEP_GOT_ROUTE);
}
payment_continue(p);
}
/* Now that we have the listpeerchannels result for the root payment, let's search
* for a direct channel that is a) connected and b) in state normal. We will
* check the capacity based on the channel_hints in the override. */
static struct command_result *direct_pay_listpeerchannels(struct command *cmd,
const char *buffer,
const jsmntok_t *toks,
struct payment *p)
{
struct listpeers_channel **channels = json_to_listpeers_channels(tmpctx, buffer, toks);
struct direct_pay_data *d = payment_mod_directpay_get_data(p);
for (size_t i=0; i<tal_count(channels); i++) {
struct listpeers_channel *chan = channels[i];
if (!chan->connected)
continue;
if (!streq(chan->state, "CHANNELD_NORMAL")
&& !streq(chan->state, "CHANNELD_AWAITING_SPLICE"))
continue;
/* Must have either a local alias for zeroconf
* channels or a final scid. */
assert(chan->alias[LOCAL] || chan->scid);
tal_free(d->chan);
d->chan = tal(d, struct short_channel_id_dir);
if (chan->scid) {
d->chan->scid = *chan->scid;
} else {
d->chan->scid = *chan->alias[LOCAL];
}
d->chan->dir = chan->direction;
}
direct_pay_override(p);
return command_still_pending(cmd);
}
static void direct_pay_cb(struct direct_pay_data *d, struct payment *p)
{
struct out_req *req;
/* Look up the direct channel only on root. */
if (p->step != PAYMENT_STEP_INITIALIZED)
return payment_continue(p);
req = jsonrpc_request_start(p->plugin, NULL, "listpeerchannels",
direct_pay_listpeerchannels,
direct_pay_listpeerchannels,
p);
json_add_node_id(req->js, "id", p->destination);
send_outreq(p->plugin, req);
}
static struct direct_pay_data *direct_pay_init(struct payment *p)
{
struct direct_pay_data *d = tal(p, struct direct_pay_data);
d->chan = NULL;
return d;
}
REGISTER_PAYMENT_MODIFIER(directpay, struct direct_pay_data *, direct_pay_init,
direct_pay_cb);
static struct command_result *waitblockheight_rpc_cb(struct command *cmd,
const char *buffer,
const jsmntok_t *toks,
struct payment *p)
{
const jsmntok_t *blockheighttok, *codetok;
u32 blockheight;
int code;
struct payment *subpayment;
blockheighttok = json_get_member(buffer, toks, "blockheight");
if (!blockheighttok ||
!json_to_number(buffer, blockheighttok, &blockheight)) {
codetok = json_get_member(buffer, toks, "code");
json_to_int(buffer, codetok, &code);
if (code == WAIT_TIMEOUT) {
payment_fail(
p,
"Timed out while attempting to sync to blockheight "
"returned by destination. Please finish syncing "
"with the blockchain and try again.");
} else {
plugin_err(
p->plugin,
"Unexpected result from waitblockheight: %.*s",
json_tok_full_len(toks),
json_tok_full(buffer, toks));
}
} else {
subpayment = payment_new(p, NULL, p, p->modifiers);
payment_start_at_blockheight(subpayment, blockheight);
payment_set_step(p, PAYMENT_STEP_RETRY);
subpayment->why = tal_fmt(
subpayment, "Retrying after waiting for blockchain sync.");
paymod_log(
p, LOG_DBG,
"Retrying after waitblockheight, new partid %" PRIu32,
subpayment->partid);
payment_continue(p);
}
return command_still_pending(cmd);
}
static void waitblockheight_cb(void *d, struct payment *p)
{
struct out_req *req;
struct timeabs now = time_now();
struct timerel remaining;
u32 blockheight;
if (p->step != PAYMENT_STEP_FAILED)
return payment_continue(p);
/* If we don't have an error message to parse we can't wait for blockheight. */
if (p->result == NULL)
return payment_continue(p);
/* Check if we'd be waiting more than 0 seconds. If we have
* less than a second then waitblockheight would return
* immediately resulting in a loop. */
if (time_after(now, p->deadline))
return payment_continue(p);
remaining = time_between(p->deadline, now);
if (time_to_sec(remaining) < 1)
return payment_continue(p);
/* *Was* it a blockheight disagreement that caused the failure? */
if (!failure_is_blockheight_disagreement(p, &blockheight))
return payment_continue(p);
paymod_log(p, LOG_INFORM,
"Remote node appears to be on a longer chain, which causes "
"CLTV timeouts to be incorrect. Waiting up to %" PRIu64
" seconds to catch up to block %d before retrying.",
time_to_sec(remaining), blockheight);
/* Set temporarily set the state of the payment to not failed, so
* interim status queries don't show this as terminally failed. We're
* in control for this payment so nobody else could be fooled by
* this. The callback will set it to retry anyway. */
payment_set_step(p, PAYMENT_STEP_RETRY);
req = jsonrpc_request_start(p->plugin, NULL, "waitblockheight",
waitblockheight_rpc_cb,
waitblockheight_rpc_cb, p);
json_add_u32(req->js, "blockheight", blockheight);
json_add_u32(req->js, "timeout", time_to_sec(remaining));
send_outreq(p->plugin, req);
}
REGISTER_PAYMENT_MODIFIER(waitblockheight, void *, NULL, waitblockheight_cb);
static u32 payment_max_htlcs(const struct payment *p)
{
const struct payment *root;
struct channel_hint *h;
u32 res = 0;
for (size_t i = 0; i < tal_count(p->channel_hints); i++) {
h = &p->channel_hints[i];
if (h->local && h->enabled)
res += h->local->htlc_budget;
}
root = p;
while (root->parent)
root = root->parent;
if (res > root->max_htlcs)
res = root->max_htlcs;
return res;
}
/** payment_lower_max_htlcs
*
* @brief indicates that we have a good reason to believe that
* we should limit our number of max HTLCs.
*
* @desc Causes future payment_max_htlcs to have a maximum value
* they return.
* Can be called by multiple paymods: the lowest one any paymod
* has given will be used.
* If this is called with a limit higher than the existing limit,
* it just successfully returns without doing anything.
*
* @param p - a payment on the payment tree we should limit.
* @param limit - the number of max HTLCs.
* @param why - the reason we think the given max HTLCs is
* reasonable.
*/
static void payment_lower_max_htlcs(struct payment *p, u32 limit,
const char *why)
{
struct payment *root = payment_root(p);
if (root->max_htlcs > limit) {
paymod_log(p, LOG_INFORM,
"%s limit on max HTLCs: %"PRIu32", %s",
root->max_htlcs == UINT32_MAX ?
"Initial" : "Lowering",
limit, why);
root->max_htlcs = limit;
}
}
static bool payment_supports_mpp(struct payment *p)
{
return feature_offered(p->features, OPT_BASIC_MPP);
}
/*****************************************************************************
* Adaptive splitter -- Split payment if we can't get it through.
*
* The adaptive splitter splits the amount of a failed payment in half, with
* +/- 10% randomness, and then starts two attempts, one for either side of
* the split. The goal is to find two smaller routes, that still adhere to our
* constraints, but that can complete the payment.
*
* This modifier also checks whether we can split and still have enough HTLCs
* available on the channels and aborts if that's no longer the case.
*/
#define MPP_ADAPTIVE_LOWER_LIMIT AMOUNT_MSAT(100 * 1000)
static struct adaptive_split_mod_data *adaptive_splitter_data_init(struct payment *p)
{
struct adaptive_split_mod_data *d;
if (p->parent == NULL) {
d = tal(p, struct adaptive_split_mod_data);
d->disable = false;
d->htlc_budget = 0;
return d;
} else {
return payment_mod_adaptive_splitter_get_data(p->parent);
}
}
static void adaptive_splitter_cb(struct adaptive_split_mod_data *d, struct payment *p)
{
struct payment *root = payment_root(p);
struct adaptive_split_mod_data *root_data =
payment_mod_adaptive_splitter_get_data(root);
if (d->disable)
return payment_continue(p);
if (!payment_supports_mpp(p) || root->abort)
return payment_continue(p);
if (p->parent == NULL && d->htlc_budget == 0) {
/* Now that we potentially had an early splitter run, let's
* update our htlc_budget that we own exclusively from now
* on. */
int children = tal_count(p->children);
d->htlc_budget = payment_max_htlcs(p);
if (children > d->htlc_budget) {
p->abort = true;
return payment_fail(
p,
"Cannot add %d HTLCs to our channels, we "
"only have %d HTLCs available.",
children, d->htlc_budget);
}
d->htlc_budget -= children;
}
if (p->step == PAYMENT_STEP_ONION_PAYLOAD) {
/* We need to tell the last hop the total we're going
* to send. MPP disables amount fuzzing, so we should
* always get the exact value through. */
size_t lastidx = tal_count(p->createonion_request->hops) - 1;
struct createonion_hop *hop = &p->createonion_request->hops[lastidx];
struct tlv_field **fields = &hop->tlv_payload->fields;
tlvstream_set_tlv_payload_data(
fields, root->payment_secret,
root->amount.millisatoshis); /* Raw: onion payload */
} else if (p->step == PAYMENT_STEP_FAILED && !p->abort) {
if (amount_msat_greater(p->amount, MPP_ADAPTIVE_LOWER_LIMIT)) {
struct payment *a, *b;
/* Random number in the range [90%, 110%] */
double rand = pseudorand_double() * 0.2 + 0.9;
u64 mid = p->amount.millisatoshis / 2 * rand; /* Raw: multiplication */
bool ok;
/* Use the start constraints, not the ones updated by routes and shadow-routes. */
struct payment_constraints *pconstraints = p->start_constraints;
/* First check that splitting doesn't exceed our HTLC budget */
if (root_data->htlc_budget == 0) {
root->abort = true;
return payment_fail(
p,
"Cannot split payment any further without "
"exceeding the maximum number of HTLCs "
"allowed by our channels");
}
p->step = PAYMENT_STEP_SPLIT;
a = payment_new(p, NULL, p, p->modifiers);
b = payment_new(p, NULL, p, p->modifiers);
a->amount.millisatoshis = mid; /* Raw: split. */
b->amount.millisatoshis -= mid; /* Raw: split. */
double multiplier = amount_msat_ratio(a->amount,
p->amount);
assert(multiplier >= 0.4 && multiplier < 0.6);
/* Adjust constraints since we don't want to double our
* fee allowance when we split. */
if (!amount_msat_scale(&a->constraints.fee_budget,
pconstraints->fee_budget,
multiplier))
abort();
ok = amount_msat_sub(&b->constraints.fee_budget,
pconstraints->fee_budget,
a->constraints.fee_budget);
/* Should not fail, mid is less than 55% of original
* amount. fee_budget_a <= 55% of fee_budget_p (parent
* of the new payments).*/
assert(ok);
payment_start(a);
payment_start(b);
paymod_log(p, LOG_DBG,
"Adaptively split into 2 sub-payments: "
"new partid %"PRIu32" (%s), "
"new partid %"PRIu32" (%s)",
a->partid,
type_to_string(tmpctx, struct amount_msat,
&a->amount),
b->partid,
type_to_string(tmpctx, struct amount_msat,
&b->amount));
/* Take note that we now have an additional split that
* may end up using an HTLC. */
root_data->htlc_budget--;
} else {
paymod_log(p, LOG_INFORM,
"Lower limit of adaptive splitter reached "
"(%s < %s), not splitting further.",
type_to_string(tmpctx, struct amount_msat,
&p->amount),
type_to_string(tmpctx, struct amount_msat,
&MPP_ADAPTIVE_LOWER_LIMIT));
}
}
payment_continue(p);
}
REGISTER_PAYMENT_MODIFIER(adaptive_splitter, struct adaptive_split_mod_data *,
adaptive_splitter_data_init, adaptive_splitter_cb);
/*****************************************************************************
* payee_incoming_limit
*
* @desc every channel has a limit on the number of HTLCs it is willing to
* transport.
* This is particularly crucial for the payers and payees, as they represent
* the bottleneck to and from the network.
* The `payment_max_htlcs` function will, by itself, be able to count the
* payer-side channels, but assessing the payee requires us to probe the
* area around it.
*
* This paymod must be *after* `routehints` paymod:
*
* - If we cannot find the destination on the public network, we can only
* use channels it put in the routehints.
* In this case, that is the number of channels we assess the payee as
* having.
* However, the `routehints` paymod may filter out some routehints, thus
* we should assess based on the post-filtered routehints.
*/
/* The default `max-concurrent-htlcs` is 30, but node operators might want
* to push it even lower to reduce their liabilities in case they have to
* unilaterally close.
* This will not necessarily improve even in a post-anchor-commitments world,
* since one of the reasons to unilaterally close is if some HTLC is about to
* expire, which of course requires the HTLCs to be published anyway, meaning
* it will still be potentially costly.
* So our initial assumption is 15 HTLCs per channel.
*/
#define ASSUMED_MAX_HTLCS_PER_CHANNEL 15
static struct command_result *
payee_incoming_limit_count(struct command *cmd,
const char *buf,
const jsmntok_t *result,
struct payment *p)
{
const jsmntok_t *channelstok;
size_t num_channels = 0;
channelstok = json_get_member(buf, result, "channels");
assert(channelstok);
/* Count channels.
* `listchannels` returns half-channels, i.e. it normally
* gives two objects per channel, one for each direction.
* However, `listchannels <source>` returns only half-channel
* objects whose `source` is the given channel.
* Thus, the length of `channels` is accurately the number
* of channels.
*/
num_channels = channelstok->size;
/* If num_channels is 0, check if there is an invoice. */
if (num_channels == 0)
num_channels = tal_count(p->routes);
/* If we got a decent number of channels, limit! */
if (num_channels != 0) {
const char *why;
u32 lim;
why = tal_fmt(tmpctx,
"Destination %s has %zd channels, "
"assuming %d HTLCs per channel",
type_to_string(tmpctx, struct node_id,
p->destination),
num_channels,
ASSUMED_MAX_HTLCS_PER_CHANNEL);
lim = num_channels * ASSUMED_MAX_HTLCS_PER_CHANNEL;
payment_lower_max_htlcs(p, lim, why);
}
payment_continue(p);
return command_still_pending(cmd);
}
static void payee_incoming_limit_step_cb(void *d UNUSED, struct payment *p)
{
/* Only operate at the initialization of te root payment.
* Also, no point operating if payment does not support MPP anyway.
*/
if (p->parent || p->step != PAYMENT_STEP_INITIALIZED
|| !payment_supports_mpp(p))
return payment_continue(p);
/* Get information on the destination. */
struct out_req *req;
req = jsonrpc_request_start(p->plugin, NULL, "listchannels",
&payee_incoming_limit_count,
&payment_rpc_failure, p);
json_add_node_id(req->js, "source", p->destination);
(void) send_outreq(p->plugin, req);
}
REGISTER_PAYMENT_MODIFIER(payee_incoming_limit, void *, NULL,
payee_incoming_limit_step_cb);
/*****************************************************************************
* check_preapproveinvoice
*
* @desc submit the invoice to the HSM for approval, fail the payment if not approved.
*
* This paymod checks the invoice for approval with the HSM, which might:
* - check with the user for specific approval
* - enforce velocity controls
* - automatically approve the invoice (default)
*/
static struct command_result *
check_preapproveinvoice_allow(struct command *cmd,
const char *buf,
const jsmntok_t *result,
struct payment *p)
{
/* On success, an empty object is returned. */
payment_continue(p);
return command_still_pending(cmd);
}
static struct command_result *preapproveinvoice_rpc_failure(struct command *cmd,
const char *buffer,
const jsmntok_t *toks,
struct payment *p)
{
payment_abort(p,
"Failing payment due to a failed RPC call: %.*s",
toks->end - toks->start, buffer + toks->start);
return command_still_pending(cmd);
}
static void check_preapproveinvoice_start(void *d UNUSED, struct payment *p)
{
/* Ask the HSM if the invoice is OK to pay */
struct out_req *req;
req = jsonrpc_request_start(p->plugin, NULL, "preapproveinvoice",
&check_preapproveinvoice_allow,
&preapproveinvoice_rpc_failure, p);
/* FIXME: rename parameter to invstring */
json_add_string(req->js, "bolt11", p->invstring);
(void) send_outreq(p->plugin, req);
}
REGISTER_PAYMENT_MODIFIER(check_preapproveinvoice, void *, NULL,
check_preapproveinvoice_start);
static struct route_exclusions_data *
route_exclusions_data_init(struct payment *p)
{
struct route_exclusions_data *d;
if (p->parent != NULL) {
return payment_mod_route_exclusions_get_data(p->parent);
} else {
d = tal(p, struct route_exclusions_data);
d->exclusions = NULL;
}
return d;
}
static void route_exclusions_step_cb(struct route_exclusions_data *d,
struct payment *p)
{
if (p->parent)
return payment_continue(p);
struct route_exclusion **exclusions = d->exclusions;
for (size_t i = 0; i < tal_count(exclusions); i++) {
struct route_exclusion *e = exclusions[i];
if (e->type == EXCLUDE_CHANNEL) {
channel_hints_update(p, e->u.chan_id.scid, e->u.chan_id.dir,
false, false, NULL, NULL);
} else {
if (node_id_eq(&e->u.node_id, p->destination)) {
payment_abort(p, "Payee is manually excluded");
return;
} else if (node_id_eq(&e->u.node_id, p->local_id)) {
payment_abort(p, "Payer is manually excluded");
return;
}
tal_arr_expand(&p->excluded_nodes, e->u.node_id);
}
}
payment_continue(p);
}
REGISTER_PAYMENT_MODIFIER(route_exclusions, struct route_exclusions_data *,
route_exclusions_data_init, route_exclusions_step_cb);
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