core-lightning/common/lease_rates.c

96 lines
2.8 KiB
C

#include "config.h"
#include <bitcoin/pubkey.h>
#include <ccan/ccan/crypto/sha256/sha256.h>
#include <ccan/ccan/mem/mem.h>
#include <common/amount.h>
#include <common/lease_rates.h>
#include <wire/peer_wire.h>
bool lease_rates_empty(struct lease_rates *rates)
{
if (!rates)
return true;
/* FIXME: why can't i do memeqzero? */
return rates->funding_weight == 0
&& rates->channel_fee_max_base_msat == 0
&& rates->channel_fee_max_proportional_thousandths == 0
&& rates->lease_fee_base_sat == 0
&& rates->lease_fee_basis == 0;
}
void lease_rates_get_commitment(struct pubkey *pubkey,
u32 lease_expiry,
u32 chan_fee_msat,
u16 chan_fee_ppt,
struct sha256 *sha)
{
struct sha256_ctx sctx = SHA256_INIT;
u8 der[PUBKEY_CMPR_LEN];
/* BOLT- #2:
* - MUST set `signature` to the ECDSA signature of
* SHA256("option_will_fund"
* || `funding_pubkey`
* || `blockheight` + 4032
* || `channel_fee_max_base_msat`
* || `channel_fee_max_proportional_thousandths`)
* using the node_id key.
*/
pubkey_to_der(der, pubkey);
sha256_update(&sctx, "option_will_fund", strlen("option_will_fund"));
sha256_update(&sctx, der, PUBKEY_CMPR_LEN);
sha256_be32(&sctx, lease_expiry);
sha256_be32(&sctx, chan_fee_msat);
sha256_be16(&sctx, chan_fee_ppt);
sha256_done(&sctx, sha);
}
bool lease_rates_calc_fee(struct lease_rates *rates,
struct amount_sat accept_funding_sats,
struct amount_sat requested_sats,
u32 onchain_feerate,
struct amount_sat *fee)
{
struct amount_sat lease_fee, basis_sat, tx_fee;
/* BOLT- #2:
* The lease fee is calculated as:
* `lease_fee_base_sat` +
* min(`accept_channel2`.`funding_satoshis`, `open_channel2`.`requested_sats`) * `lease_fee_basis` / 10_000 +
* `funding_weight` * `funding_feerate_perkw` / 1000
*/
lease_fee = amount_sat(rates->lease_fee_base_sat);
basis_sat = amount_sat_less(accept_funding_sats, requested_sats)
? accept_funding_sats : requested_sats;
if (!amount_sat_scale(&basis_sat, basis_sat,
rates->lease_fee_basis))
return false;
basis_sat = amount_sat_div(basis_sat, 10000);
if (!amount_sat_add(&lease_fee, lease_fee, basis_sat))
return false;
tx_fee = amount_tx_fee(onchain_feerate, rates->funding_weight);
if (!amount_sat_add(&lease_fee, lease_fee, tx_fee))
return false;
*fee = lease_fee;
return true;
}
bool lease_rates_set_chan_fee_base_msat(struct lease_rates *rates,
struct amount_msat amt)
{
rates->channel_fee_max_base_msat = amt.millisatoshis; /* Raw: conversion */
return rates->channel_fee_max_base_msat == amt.millisatoshis; /* Raw: comparsion */
}
bool lease_rates_set_lease_fee_sat(struct lease_rates *rates,
struct amount_sat amt)
{
rates->lease_fee_base_sat = amt.satoshis; /* Raw: conversion */
return rates->lease_fee_base_sat == amt.satoshis; /* Raw: comparsion */
}