core-lightning/bitcoin/short_channel_id.h
Rusty Russell 9f1f79587e short_channel_id_dir: new primitive for one direction of short_channel_id
Currently only used by gossipd for channel elimination.

Also print them in canonical form (/[01]), so tests need to be
changed.

Suggested-by: @cdecker
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2019-01-15 12:01:38 +01:00

65 lines
1.9 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 <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;
}
void mk_short_channel_id(struct short_channel_id *scid,
u32 blocknum, u32 txnum, u16 outnum);
bool 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 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 */