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/* SPDX-License-Identifier: LGPL-2.1-or-later */
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include "fd-util.h"
#include "hexdecoct.h"
#include "id128-util.h"
#include "io-util.h"
#include "stdio-util.h"
#include "string-util.h"
#include "sync-util.h"
bool id128_is_valid(const char *s) {
size_t i, l;
assert(s);
l = strlen(s);
if (l == 32) {
/* Plain formatted 128bit hex string */
for (i = 0; i < l; i++) {
char c = s[i];
if (!(c >= '0' && c <= '9') &&
!(c >= 'a' && c <= 'z') &&
!(c >= 'A' && c <= 'Z'))
return false;
}
} else if (l == 36) {
/* Formatted UUID */
for (i = 0; i < l; i++) {
char c = s[i];
if (IN_SET(i, 8, 13, 18, 23)) {
if (c != '-')
return false;
} else {
if (!(c >= '0' && c <= '9') &&
!(c >= 'a' && c <= 'z') &&
!(c >= 'A' && c <= 'Z'))
return false;
}
}
} else
return false;
return true;
}
int id128_read_fd(int fd, Id128Format f, sd_id128_t *ret) {
char buffer[36 + 2];
ssize_t l;
assert(fd >= 0);
assert(f < _ID128_FORMAT_MAX);
/* Reads an 128bit ID from a file, which may either be in plain format (32 hex digits), or in UUID format, both
* optionally followed by a newline and nothing else. ID files should really be newline terminated, but if they
* aren't that's OK too, following the rule of "Be conservative in what you send, be liberal in what you
* accept". */
l = loop_read(fd, buffer, sizeof(buffer), false); /* we expect a short read of either 32/33 or 36/37 chars */
if (l < 0)
return (int) l;
if (l == 0) /* empty? */
return -ENOMEDIUM;
switch (l) {
case 13:
case 14:
/* Treat an "uninitialized" id file like an empty one */
return f == ID128_PLAIN_OR_UNINIT && strneq(buffer, "uninitialized\n", l) ? -ENOMEDIUM : -EINVAL;
case 33: /* plain UUID with trailing newline */
if (buffer[32] != '\n')
return -EINVAL;
_fallthrough_;
case 32: /* plain UUID without trailing newline */
if (f == ID128_UUID)
return -EINVAL;
buffer[32] = 0;
break;
case 37: /* RFC UUID with trailing newline */
if (buffer[36] != '\n')
return -EINVAL;
_fallthrough_;
case 36: /* RFC UUID without trailing newline */
if (IN_SET(f, ID128_PLAIN, ID128_PLAIN_OR_UNINIT))
return -EINVAL;
buffer[36] = 0;
break;
default:
return -EINVAL;
}
return sd_id128_from_string(buffer, ret);
}
int id128_read(const char *p, Id128Format f, sd_id128_t *ret) {
_cleanup_close_ int fd = -1;
fd = open(p, O_RDONLY|O_CLOEXEC|O_NOCTTY);
if (fd < 0)
return -errno;
return id128_read_fd(fd, f, ret);
}
int id128_write_fd(int fd, Id128Format f, sd_id128_t id, bool do_sync) {
char buffer[36 + 2];
size_t sz;
int r;
assert(fd >= 0);
assert(f < _ID128_FORMAT_MAX);
if (f != ID128_UUID) {
assert_se(sd_id128_to_string(id, buffer));
buffer[SD_ID128_STRING_MAX - 1] = '\n';
sz = SD_ID128_STRING_MAX;
} else {
assert_se(sd_id128_to_uuid_string(id, buffer));
buffer[SD_ID128_UUID_STRING_MAX - 1] = '\n';
sz = SD_ID128_UUID_STRING_MAX;
}
r = loop_write(fd, buffer, sz, false);
if (r < 0)
return r;
if (do_sync) {
r = fsync_full(fd);
if (r < 0)
return r;
}
return 0;
}
int id128_write(const char *p, Id128Format f, sd_id128_t id, bool do_sync) {
_cleanup_close_ int fd = -1;
fd = open(p, O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY|O_TRUNC, 0444);
if (fd < 0)
return -errno;
return id128_write_fd(fd, f, id, do_sync);
}
void id128_hash_func(const sd_id128_t *p, struct siphash *state) {
siphash24_compress(p, sizeof(sd_id128_t), state);
}
int id128_compare_func(const sd_id128_t *a, const sd_id128_t *b) {
return memcmp(a, b, 16);
}
sd_id128_t id128_make_v4_uuid(sd_id128_t id) {
/* Stolen from generate_random_uuid() of drivers/char/random.c
* in the kernel sources */
/* Set UUID version to 4 --- truly random generation */
id.bytes[6] = (id.bytes[6] & 0x0F) | 0x40;
/* Set the UUID variant to DCE */
id.bytes[8] = (id.bytes[8] & 0x3F) | 0x80;
return id;
}
DEFINE_HASH_OPS(id128_hash_ops, sd_id128_t, id128_hash_func, id128_compare_func);
int id128_get_product(sd_id128_t *ret) {
sd_id128_t uuid;
int r;
assert(ret);
/* Reads the systems product UUID from DMI or devicetree (where it is located on POWER). This is
* particularly relevant in VM environments, where VM managers typically place a VM uuid there. */
r = id128_read("/sys/class/dmi/id/product_uuid", ID128_UUID, &uuid);
if (r == -ENOENT)
r = id128_read("/proc/device-tree/vm,uuid", ID128_UUID, &uuid);
if (r < 0)
return r;
if (sd_id128_is_null(uuid) || sd_id128_is_allf(uuid))
return -EADDRNOTAVAIL; /* Recognizable error */
*ret = uuid;
return 0;
}
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