core-lightning/bitcoin/short_channel_id.c
Rusty Russell 269dbe585c wire: move short_channel formatting functions into bitcoin/short_channel_id
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2019-02-21 00:44:57 +00:00

103 lines
3.1 KiB
C

#include <bitcoin/short_channel_id.h>
#include <ccan/tal/str/str.h>
#include <common/type_to_string.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.
*/
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,
bool may_be_deprecated_form)
{
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 (may_be_deprecated_form && 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
return matches == 3
&& mk_short_channel_id(dst, blocknum, txnum, outnum);
}
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));
}
bool short_channel_id_dir_from_str(const char *str, size_t strlen,
struct short_channel_id_dir *scidd,
bool may_be_deprecated_form)
{
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,
may_be_deprecated_form))
return false;
if (slash[1] == '0')
scidd->dir = 0;
else if (slash[1] == '1')
scidd->dir = 1;
else
return false;
return true;
}
char *short_channel_id_dir_to_str(const tal_t *ctx,
const struct short_channel_id_dir *scidd)
{
char *str, *scidstr = short_channel_id_to_str(NULL, &scidd->scid);
str = tal_fmt(ctx, "%s/%u", scidstr, scidd->dir);
tal_free(scidstr);
return str;
}
REGISTER_TYPE_TO_STRING(short_channel_id, short_channel_id_to_str);
REGISTER_TYPE_TO_STRING(short_channel_id_dir, short_channel_id_dir_to_str);