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lvm2/lib/uuid/uuid.c

114 lines
2.0 KiB
C

/*
* Copyright (C) 2001 Sistina Software (UK) Limited.
*
* This file is released under the LGPL.
*/
#include "uuid.h"
#include "log.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
static unsigned char _c[] =
"0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
static int _built_inverse;
static unsigned char _inverse_c[256];
int id_create(struct id *id)
{
int random, i, len = sizeof(id->uuid);
memset(id->uuid, 0, len);
if ((random = open("/dev/urandom", O_RDONLY)) < 0) {
log_sys_error("open", "id_create");
return 0;
}
if (read(random, id->uuid, len) != len) {
log_sys_error("read", "id_create");
return 0;
}
close(random);
for (i = 0; i < len; i++)
id->uuid[i] = _c[id->uuid[i] % (sizeof(_c) - 1)];
return 1;
}
/*
* The only validity check we have is that
* the uuid just contains characters from
* '_c'. A checksum would have been nice :(
*/
void _build_inverse(void)
{
char *ptr;
if (_built_inverse)
return;
memset(_inverse_c, 0, sizeof(_inverse_c));
for (ptr = _c; *ptr; ptr++)
_inverse_c[(int) *ptr] = (char) 0x1;
}
int id_valid(struct id *id)
{
int i;
_build_inverse();
for (i = 0; i < ID_LEN; i++)
if (!_inverse_c[id->uuid[i]]) {
log_err("UUID contains invalid character");
return 0;
}
return 1;
}
int id_cmp(struct id *lhs, struct id *rhs)
{
return memcmp(lhs->uuid, rhs->uuid, sizeof(lhs->uuid));
}
#define GROUPS (ID_LEN / 4)
int id_write_format(struct id *id, char *buffer, size_t size)
{
int i;
/* split into 8 groups of four, with dashes in between */
if (size < (GROUPS * 5))
return 0;
for (i = 0; i < GROUPS; i++) {
memcpy(buffer + (i * 5), id->uuid + (i * 4), 4);
buffer[(i * 5) + 4] = '-';
}
buffer[(GROUPS * 5) - 1] = '\0';
return 1;
}
int id_read_format(struct id *id, char *buffer)
{
int i;
if (strlen(buffer) < (GROUPS * 5)) {
log_err("Insufficient characters to be a proper uuid.");
return 0;
}
for (i = 0; i < ID_LEN; i++)
id->uuid[i] = buffer[((i / 4) * 5) + (i % 4)];
return id_valid(id);
}