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#ifndef LIGHTNING_BITCOIN_SHORT_CHANNEL_ID_H
#define LIGHTNING_BITCOIN_SHORT_CHANNEL_ID_H
#include "config.h"
#include <ccan/short_types/short_types.h>
#include <ccan/structeq/structeq.h>
#include <ccan/tal/tal.h>
#include <common/gossip_constants.h>
#include <stdbool.h>
#include <stddef.h>
/* Short Channel ID is composed of 3 bytes for the block height, 3
* bytes of tx index in block and 2 bytes of output index. */
struct short_channel_id {
u64 u64;
};
/* Define short_channel_id_eq (no padding) */
STRUCTEQ_DEF(short_channel_id, 0, u64);
/* BOLT #7:
*
* - MUST set `node_id_1` and `node_id_2` to the public keys of the two nodes
* operating the channel, such that `node_id_1` is the lexicographically-lesser of the
* two compressed keys sorted in ascending lexicographic order.
*...
* - if the origin node is `node_id_1` in the message:
* - MUST set the `direction` bit of `channel_flags` to 0.
* - otherwise:
* - MUST set the `direction` bit of `channel_flags` to 1.
*/
struct short_channel_id_dir {
struct short_channel_id scid;
/* 0 == from lesser id node, 1 == to lesser id node */
int dir;
};
static inline u32 short_channel_id_blocknum(const struct short_channel_id *scid)
{
return scid->u64 >> 40;
}
static inline u32 short_channel_id_txnum(const struct short_channel_id *scid)
{
return (scid->u64 >> 16) & 0x00FFFFFF;
}
static inline u16 short_channel_id_outnum(const struct short_channel_id *scid)
{
return scid->u64 & 0xFFFF;
}
/* Subtly, at block N, depth is 1, hence the -1 here. eg. 103x1x0 is announceable
* when height is 108. */
static inline bool
is_scid_depth_announceable(const struct short_channel_id *scid,
unsigned int height)
{
return short_channel_id_blocknum(scid) + ANNOUNCE_MIN_DEPTH - 1
<= height;
}
/* Returns false if blocknum, txnum or outnum require too many bits */
bool WARN_UNUSED_RESULT mk_short_channel_id(struct short_channel_id *scid,
u64 blocknum, u64 txnum, u64 outnum);
bool WARN_UNUSED_RESULT short_channel_id_from_str(const char *str, size_t strlen,
struct short_channel_id *dst);
char *short_channel_id_to_str(const tal_t *ctx, const struct short_channel_id *scid);
bool WARN_UNUSED_RESULT short_channel_id_dir_from_str(const char *str, size_t strlen,
struct short_channel_id_dir *scidd);
char *short_channel_id_dir_to_str(const tal_t *ctx,
const struct short_channel_id_dir *scidd);
/* Marshal/unmarshal */
void towire_short_channel_id(u8 **pptr,
const struct short_channel_id *short_channel_id);
void towire_short_channel_id_dir(u8 **pptr,
const struct short_channel_id_dir *scidd);
void fromwire_short_channel_id(const u8 **cursor, size_t *max,
struct short_channel_id *short_channel_id);
void fromwire_short_channel_id_dir(const u8 **cursor, size_t *max,
struct short_channel_id_dir *scidd);
#endif /* LIGHTNING_BITCOIN_SHORT_CHANNEL_ID_H */