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-rw-r--r--src/libsystemd/sd-id128/id128-util.c212
1 files changed, 212 insertions, 0 deletions
diff --git a/src/libsystemd/sd-id128/id128-util.c b/src/libsystemd/sd-id128/id128-util.c
new file mode 100644
index 0000000..a3f6da6
--- /dev/null
+++ b/src/libsystemd/sd-id128/id128-util.c
@@ -0,0 +1,212 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "fd-util.h"
+#include "fs-util.h"
+#include "hexdecoct.h"
+#include "id128-util.h"
+#include "io-util.h"
+#include "stdio-util.h"
+#include "string-util.h"
+
+char *id128_to_uuid_string(sd_id128_t id, char s[static ID128_UUID_STRING_MAX]) {
+ unsigned n, k = 0;
+
+ assert(s);
+
+ /* Similar to sd_id128_to_string() but formats the result as UUID instead of plain hex chars */
+
+ for (n = 0; n < 16; n++) {
+
+ if (IN_SET(n, 4, 6, 8, 10))
+ s[k++] = '-';
+
+ s[k++] = hexchar(id.bytes[n] >> 4);
+ s[k++] = hexchar(id.bytes[n] & 0xF);
+ }
+
+ assert(k == 36);
+
+ s[k] = 0;
+
+ return s;
+}
+
+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) {
+ sd_id128_to_string(id, buffer);
+ buffer[32] = '\n';
+ sz = 33;
+ } else {
+ id128_to_uuid_string(id, buffer);
+ buffer[36] = '\n';
+ sz = 37;
+ }
+
+ r = loop_write(fd, buffer, sz, false);
+ if (r < 0)
+ return r;
+
+ if (do_sync) {
+ if (fsync(fd) < 0)
+ return -errno;
+
+ r = fsync_directory_of_file(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);