rgb-cln/bitcoin/short_channel_id.c

64 lines
2.0 KiB
C

#include <bitcoin/short_channel_id.h>
#include <ccan/tal/str/str.h>
#include <stdio.h>
#include <string.h>
/* BOLT#07:
*
* The `short_channel_id` is the unique description of the funding
* transaction. It is constructed as follows:
* 1. the most significant 3 bytes: indicating the block height
* 2. the next 3 bytes: indicating the transaction index within the block
* 3. the least significant 2 bytes: indicating the output index that pays to the channel.
*
* The standard human readable format for `short_channel_id` is created
* by printing the above components, in the order: block height,
* transaction index, and output index. Each component is printed as a
* decimal number, and separated from each other by the small letter
* `x`. For example, a `short_channel_id` might be written as
* `539268x845x1`, indicating a channel on the output 1 of the
* transaction at index 845 of the block at height 539268.
*/
void mk_short_channel_id(struct short_channel_id *scid,
u32 blocknum, u32 txnum, u16 outnum)
{
scid->u64 = (((u64)blocknum & 0xFFFFFF) << 40 |
((u64)txnum & 0xFFFFFF) << 16 |
(outnum & 0xFFFF));
}
bool short_channel_id_from_str(const char *str, size_t strlen,
struct short_channel_id *dst)
{
u32 blocknum, txnum;
u16 outnum;
int matches;
char buf[strlen + 1];
memcpy(buf, str, strlen);
buf[strlen] = 0;
#ifdef COMPAT_V062
/* Pre-adelaide format vs. post-adelaide format */
if (strchr(buf, ':'))
matches = sscanf(buf, "%u:%u:%hu", &blocknum, &txnum, &outnum);
else
matches = sscanf(buf, "%ux%ux%hu", &blocknum, &txnum, &outnum);
#else
matches = sscanf(buf, "%ux%ux%hu", &blocknum, &txnum, &outnum);
#endif
mk_short_channel_id(dst, blocknum, txnum, outnum);
return matches == 3;
}
char *short_channel_id_to_str(const tal_t *ctx, const struct short_channel_id *scid)
{
return tal_fmt(ctx, "%dx%dx%d",
short_channel_id_blocknum(scid),
short_channel_id_txnum(scid),
short_channel_id_outnum(scid));
}