core-lightning/bitcoin/short_channel_id.c
Rusty Russell 9450d46db1 bitcoin/short_channel_id: pass by copy everywhere.
It's a u64, we should pass by copy.  This is a big sweeping change,
but mainly mechanical (change one, compile, fix breakage, repeat).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2024-03-20 13:51:48 +10:30

102 lines
2.8 KiB
C

#include "config.h"
#include <bitcoin/short_channel_id.h>
#include <ccan/tal/str/str.h>
#include <stdio.h>
#include <wire/wire.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.
*/
bool mk_short_channel_id(struct short_channel_id *scid,
u64 blocknum, u64 txnum, u64 outnum)
{
if ((blocknum & 0xFFFFFF) != blocknum
|| (txnum & 0xFFFFFF) != txnum
|| (outnum & 0xFFFF) != outnum)
return false;
scid->u64 = (((u64)blocknum & 0xFFFFFF) << 40 |
((u64)txnum & 0xFFFFFF) << 16 |
(outnum & 0xFFFF));
return true;
}
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;
matches = sscanf(buf, "%ux%ux%hu", &blocknum, &txnum, &outnum);
return matches == 3
&& mk_short_channel_id(dst, blocknum, txnum, outnum);
}
char *fmt_short_channel_id(const tal_t *ctx, 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));
}
bool short_channel_id_dir_from_str(const char *str, size_t strlen,
struct short_channel_id_dir *scidd)
{
const char *slash = memchr(str, '/', strlen);
if (!slash || slash + 2 != str + strlen)
return false;
if (!short_channel_id_from_str(str, slash - str, &scidd->scid))
return false;
if (slash[1] == '0')
scidd->dir = 0;
else if (slash[1] == '1')
scidd->dir = 1;
else
return false;
return true;
}
char *fmt_short_channel_id_dir(const tal_t *ctx,
const struct short_channel_id_dir *scidd)
{
char *str, *scidstr = fmt_short_channel_id(NULL, scidd->scid);
str = tal_fmt(ctx, "%s/%u", scidstr, scidd->dir);
tal_free(scidstr);
return str;
}
void towire_short_channel_id(u8 **pptr,
struct short_channel_id short_channel_id)
{
towire_u64(pptr, short_channel_id.u64);
}
struct short_channel_id fromwire_short_channel_id(const u8 **cursor, size_t *max)
{
struct short_channel_id scid;
scid.u64 = fromwire_u64(cursor, max);
return scid;
}