mirror of
https://github.com/ElementsProject/lightning.git
synced 2024-11-19 18:11:28 +01:00
45381bba33
The math is a bit tricky, so encapsulate it. Includes the extra 'e' in 'announcable' as noted by @cdecker :) Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
77 lines
2.4 KiB
C
77 lines
2.4 KiB
C
#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 numerically-lesser of the
|
|
* two DER-encoded keys sorted in ascending numerical 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);
|
|
|
|
#endif /* LIGHTNING_BITCOIN_SHORT_CHANNEL_ID_H */
|