mirrors/core-lightning
1
0
Fork 0
mirror of https://github.com/ElementsProject/lightning.git synced 2025-03-03 18:57:06 +01:00
Code Issues Projects Releases Wiki Activity

payalgo: Randomize paths as long as we respect maxfeepercent.

Browse source
This commit is contained in:
ZmnSCPxj 2018-02-16 15:44:00 +00:00 • committed by Rusty Russell
parent 9693843141
commit 61d0b50c54
1 changed files with 40 additions and 10 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

50
lightningd/payalgo.c
View file

@ -1,5 +1,6 @@
#include "pay.h"
#include "payalgo.h"
#include <ccan/isaac/isaac64.h>
#include <ccan/tal/str/str.h>
#include <ccan/time/time.h>
#include <common/bolt11.h>
@ -9,6 +10,7 @@
#include <lightningd/jsonrpc_errors.h>
#include <lightningd/lightningd.h>
#include <lightningd/subd.h>
#include <sodium/randombytes.h>
struct pay {
/* Parent command. */
@ -25,8 +27,12 @@ struct pay {
double riskfactor;
double maxfeepercent;
/* Number of payment tries */
unsigned int tries;
/* Number of getroute and sendpay tries */
unsigned int getroute_tries;
unsigned int sendpay_tries;
/* Current fuzz we pass into getroute. */
double fuzz;
/* Parent of the current pay attempt. This object is
* freed, then allocated at the start of each pay
@ -37,7 +43,8 @@ struct pay {
static void
json_pay_success(struct command *cmd,
const struct preimage *payment_preimage,
unsigned int tries)
unsigned int getroute_tries,
unsigned int sendpay_tries)
{
struct json_result *response;
@ -45,7 +52,8 @@ json_pay_success(struct command *cmd,
json_object_start(response, NULL);
json_add_hex(response, "preimage",
payment_preimage, sizeof(*payment_preimage));
json_add_num(response, "tries", tries);
json_add_num(response, "getroute_tries", getroute_tries);
json_add_num(response, "sendpay_tries", sendpay_tries);
json_object_end(response);
command_success(cmd, response);
}
@ -126,7 +134,8 @@ static void json_pay_sendpay_resolve(const struct sendpay_result *r,
/* If we succeed, hurray */
if (r->succeeded) {
json_pay_success(pay->cmd, &r->preimage, pay->tries);
json_pay_success(pay->cmd, &r->preimage,
pay->getroute_tries, pay->sendpay_tries);
return;
}
@ -149,6 +158,7 @@ static void json_pay_getroute_reply(struct subd *gossip UNUSED,
u64 msatoshi_sent;
u64 fee;
double feepercent;
bool fee_too_high;
struct json_result *data;
fromwire_gossip_getroute_reply(reply, reply, &route);
@ -169,7 +179,9 @@ static void json_pay_getroute_reply(struct subd *gossip UNUSED,
* and thus losing precision in the below. Currently, OK, as,
* payments are limited to 4294967295 msatoshi. */
feepercent = ((double) fee) * 100.0 / ((double) pay->msatoshi);
if (feepercent > pay->maxfeepercent) {
fee_too_high = (feepercent > pay->maxfeepercent);
/* compare fuzz to range */
if (fee_too_high && pay->fuzz < 0.01) {
data = new_json_result(pay);
json_object_start(data, NULL);
json_add_u64(data, "fee", fee);
@ -188,6 +200,16 @@ static void json_pay_getroute_reply(struct subd *gossip UNUSED,
pay->maxfeepercent);
return;
}
if (fee_too_high) {
/* Retry with lower fuzz */
pay->fuzz -= 0.15;
if (pay->fuzz <= 0.0)
pay->fuzz = 0.0;
json_pay_try(pay);
return;
}
++pay->sendpay_tries;
send_payment(pay->try_parent,
pay->cmd->ld, &pay->payment_hash, route,
@ -198,6 +220,7 @@ static void json_pay_getroute_reply(struct subd *gossip UNUSED,
* false if resolved now. */
static bool json_pay_try(struct pay *pay)
{
u8 *seed;
u8 *req;
struct command *cmd = pay->cmd;
struct timeabs now = time_now();
@ -215,11 +238,15 @@ static bool json_pay_try(struct pay *pay)
return false;
}
/* Clear previous sendpay. */
/* Clear previous try memory. */
pay->try_parent = tal_free(pay->try_parent);
pay->try_parent = tal(pay, char);
++pay->tries;
/* Generate random seed */
seed = tal_arr(pay->try_parent, u8, ISAAC64_SEED_SZ_MAX);
randombytes_buf(seed, tal_len(seed));
++pay->getroute_tries;
/* FIXME: use b11->routes */
req = towire_gossip_getroute_request(pay->try_parent,
@ -228,7 +255,8 @@ static bool json_pay_try(struct pay *pay)
pay->msatoshi,
pay->riskfactor,
pay->min_final_cltv_expiry,
0, tal_arrz(pay->try_parent, u8, 8));
&pay->fuzz,
seed);
subd_req(pay->try_parent, cmd->ld->gossip, req, -1, 0, json_pay_getroute_reply, pay);
return true;
@ -326,7 +354,9 @@ static void json_pay(struct command *cmd,
}
pay->maxfeepercent = maxfeepercent;
pay->tries = 0;
pay->getroute_tries = 0;
pay->sendpay_tries = 0;
pay->fuzz = 0.75;
pay->try_parent = NULL;
/* Initiate payment */