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#ifndef LIGHTNING_FUNDING_H
#define LIGHTNING_FUNDING_H
#include "config.h"
#include "bitcoin/locktime.h"
#include <ccan/crypto/sha256/sha256.h>
#include <ccan/tal/tal.h>
#include <stdbool.h>
struct channel_htlc {
u64 id;
u64 msatoshis;
struct abs_locktime expiry;
struct sha256 rhash;
};
struct channel_oneside {
/* Payment and fee is in millisatoshi. */
uint32_t pay_msat, fee_msat;
/* Use tal_count to get the number */
struct channel_htlc *htlcs;
};
enum channel_side {
/* Output for us, htlcs we offered to them. */
OURS,
/* Output for them, htlcs they offered to us. */
THEIRS
};
struct channel_state {
/* Satoshis paid by anchor. */
uint64_t anchor;
/* Satoshis per 1000 bytes. */
uint32_t fee_rate;
/* Generation counter (incremented on every change) */
uint32_t changes;
struct channel_oneside side[2];
};
/**
* initial_funding: Given initial fees and funding anchor, what is initial state?
* @ctx: tal context to allocate return value from.
* @anchor_satoshis: The anchor amount.
* @fee_rate: amount to pay in fees per kb (in satoshi).
* @dir: which side paid for the anchor.
*
* Returns state, or NULL if malformed.
*/
struct channel_state *initial_funding(const tal_t *ctx,
uint64_t anchor_satoshis,
uint32_t fee_rate,
enum channel_side side);
/**
* copy_funding: Make a deep copy of channel_state
* @ctx: tal context to allocate return value from.
* @cstate: state to copy.
*/
struct channel_state *copy_funding(const tal_t *ctx,
const struct channel_state *cstate);
/**
* funding_add_htlc: append an HTLC to cstate if it can afford it
* @cstate: The channel state
* @msatoshis: Millisatoshi going into a HTLC
* @expiry: time it expires
* @rhash: hash of redeem secret
* @id: 64-bit ID for htlc
* @side: OURS or THEIRS
*
* If that direction can't afford the HTLC (or still owes its half of the fees),
* this will return NULL and leave @cstate unchanged. Otherwise
* cstate->side[dir].htlcs will have the HTLC appended, and pay_msat and
* fee_msat are adjusted accordingly; &cstate->side[dir].htlcs[<last>]
* is returned.
*/
struct channel_htlc *funding_add_htlc(struct channel_state *cstate,
u32 msatoshis,
const struct abs_locktime *expiry,
const struct sha256 *rhash, uint64_t id,
enum channel_side side);
/**
* funding_fail_htlc: remove an HTLC, funds to the side which offered it.
* @cstate: The channel state
* @htlc: the htlc in cstate->side[dir].htlcs[].
* @side: OURS or THEIRS
*
* This will remove the @index'th entry in cstate->side[dir].htlcs[], and credit
* the value of the HTLC (back) to cstate->side[dir].
*/
void funding_fail_htlc(struct channel_state *cstate,
struct channel_htlc *htlc,
enum channel_side side);
/**
* funding_fulfill_htlc: remove an HTLC, funds to side which accepted it.
* @cstate: The channel state
* @htlc: the htlc in cstate->side[dir].htlcs[].
* @side: OURS or THEIRS
*
* This will remove the @index'th entry in cstate->side[dir].htlcs[], and credit
* the value of the HTLC to cstate->side[!dir].
*/
void funding_fulfill_htlc(struct channel_state *cstate,
struct channel_htlc *htlc,
enum channel_side side);
/**
* adjust_fee: Change fee rate.
* @cstate: The channel state
* @fee_rate: fee in satoshi per 1000 bytes.
*/
void adjust_fee(struct channel_state *cstate, uint32_t fee_rate);
/**
* force_fee: Change fee to a specific value.
* @cstate: The channel state
* @fee: fee in satoshi.
*
* This is used for the close transaction, which specifies an exact fee.
* If the fee cannot be paid in full, this return false (but cstate will
* still be altered).
*/
bool force_fee(struct channel_state *cstate, uint64_t fee);
/**
* funding_find_htlc: find an HTLC on this side of the channel.
* @cstate: The channel state
* @rhash: hash of redeem secret
* @side: OURS or THEIRS
*
* Returns a number < tal_count(cstate->side[dir].htlcs), or -1 on fail.
*/
size_t funding_find_htlc(const struct channel_state *cstate,
const struct sha256 *rhash,
enum channel_side side);
/**
* funding_htlc_by_id: find an HTLC on this side of the channel by ID.
* @cstate: The channel state
* @id: id for HTLC.
* @side: OURS or THEIRS
*
* Returns a pointer into cstate->side[@side].htlcs, or NULL.
*/
struct channel_htlc *funding_htlc_by_id(const struct channel_state *cstate,
uint64_t id,
enum channel_side side);
/**
* fee_for_feerate: calculate the fee (in satoshi) for a given fee_rate.
* @txsize: transaction size in bytes.
* @fee_rate: satoshi per 1000 bytes.
*/
uint64_t fee_by_feerate(size_t txsize, uint32_t fee_rate);
/**
* is_dust_amount: is an output of this value considered dust?
* @satoshis: number of satoshis.
*
* Transactions with dust outputs will not be relayed by the bitcoin
* network. It's not an exact definition, unfortunately.
*/
bool is_dust_amount(uint64_t satoshis);
#endif /* LIGHTNING_FUNDING_H */