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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/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->route = NULL;
p->temp_exclusion = NULL;
p->failroute_retry = false;
p->invstring = NULL;
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->destination_has_tlv = parent->destination_has_tlv;
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_offer_id = parent->local_offer_id;
p->groupid = parent->groupid;
} 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++;
/* Caller must set this. */
p->local_id = NULL;
p->local_offer_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 hint;
/* 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 && *htlc_budget < hint->htlc_budget) {
hint->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. */
hint.enabled = enabled;
hint.scid.scid = scid;
hint.scid.dir = direction;
hint.local = local;
if (estimated_capacity != NULL)
hint.estimated_capacity = *estimated_capacity;
if (htlc_budget != NULL)
hint.htlc_budget = *htlc_budget;
tal_arr_expand(&root->channel_hints, hint);
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, &hint.scid),
hint.enabled ? "true" : "false",
type_to_string(tmpctx, struct amount_msat,
&hint.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->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(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));
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 && remove)
curhint->htlc_budget++;
else if (curhint->local)
curhint->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_eq(p->amount,
hint->estimated_capacity))
/* We exclude on equality because we've set the
* estimate to the smallest failed attempt. */
tal_arr_expand(&res, hint->scid);
else if (hint->local && hint->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->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 capmsat, amtmsat = amount.millisatoshis; /* Raw: lengthy math */
/* Can fail in theory if gossmap changed underneath. */
if (!gossmap_chan_get_capacity(map, c, &capacity))
return 0;
capmsat = 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(ctx, 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;
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 u8 *tal_towire_legacy_payload(const tal_t *ctx, const struct legacy_payload *payload)
{
const u8 padding[] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
/* Prepend 0 byte for realm */
u8 *buf = tal_arrz(ctx, u8, 1);
towire_short_channel_id(&buf, &payload->scid);
towire_amount_msat(&buf, payload->forward_amt);
towire_u32(&buf, payload->outgoing_cltv);
towire(&buf, padding, ARRAY_SIZE(padding));
assert(tal_bytelen(buf) == 1 + 32);
return buf;
}
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 || senttok->type != JSMN_STRING ||
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);