--- /dev/null
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+ This file is part of systemd.
+
+ Copyright 2011 Lennart Poettering
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+
+ systemd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "util.h"
+#include "macro.h"
+#include "sd-id128.h"
+
+_public_ char *sd_id128_to_string(sd_id128_t id, char s[33]) {
+ unsigned n;
+
+ assert_return(s, NULL);
+
+ for (n = 0; n < 16; n++) {
+ s[n*2] = hexchar(id.bytes[n] >> 4);
+ s[n*2+1] = hexchar(id.bytes[n] & 0xF);
+ }
+
+ s[32] = 0;
+
+ return s;
+}
+
+_public_ int sd_id128_from_string(const char s[], sd_id128_t *ret) {
+ unsigned n, i;
+ sd_id128_t t;
+ bool is_guid = false;
+
+ assert_return(s, -EINVAL);
+ assert_return(ret, -EINVAL);
+
+ for (n = 0, i = 0; n < 16;) {
+ int a, b;
+
+ if (s[i] == '-') {
+ /* Is this a GUID? Then be nice, and skip over
+ * the dashes */
+
+ if (i == 8)
+ is_guid = true;
+ else if (i == 13 || i == 18 || i == 23) {
+ if (!is_guid)
+ return -EINVAL;
+ } else
+ return -EINVAL;
+
+ i++;
+ continue;
+ }
+
+ a = unhexchar(s[i++]);
+ if (a < 0)
+ return -EINVAL;
+
+ b = unhexchar(s[i++]);
+ if (b < 0)
+ return -EINVAL;
+
+ t.bytes[n++] = (a << 4) | b;
+ }
+
+ if (i != (is_guid ? 36 : 32))
+ return -EINVAL;
+
+ if (s[i] != 0)
+ return -EINVAL;
+
+ *ret = t;
+ return 0;
+}
+
+static sd_id128_t 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;
+}
+
+_public_ int sd_id128_get_machine(sd_id128_t *ret) {
+ static thread_local sd_id128_t saved_machine_id;
+ static thread_local bool saved_machine_id_valid = false;
+ _cleanup_close_ int fd = -1;
+ char buf[33];
+ ssize_t k;
+ unsigned j;
+ sd_id128_t t;
+
+ assert_return(ret, -EINVAL);
+
+ if (saved_machine_id_valid) {
+ *ret = saved_machine_id;
+ return 0;
+ }
+
+ fd = open("/etc/machine-id", O_RDONLY|O_CLOEXEC|O_NOCTTY);
+ if (fd < 0)
+ return -errno;
+
+ k = loop_read(fd, buf, 33, false);
+ if (k < 0)
+ return (int) k;
+
+ if (k != 33)
+ return -EIO;
+
+ if (buf[32] !='\n')
+ return -EIO;
+
+ for (j = 0; j < 16; j++) {
+ int a, b;
+
+ a = unhexchar(buf[j*2]);
+ b = unhexchar(buf[j*2+1]);
+
+ if (a < 0 || b < 0)
+ return -EIO;
+
+ t.bytes[j] = a << 4 | b;
+ }
+
+ saved_machine_id = t;
+ saved_machine_id_valid = true;
+
+ *ret = t;
+ return 0;
+}
+
+_public_ int sd_id128_get_boot(sd_id128_t *ret) {
+ static thread_local sd_id128_t saved_boot_id;
+ static thread_local bool saved_boot_id_valid = false;
+ _cleanup_close_ int fd = -1;
+ char buf[36];
+ ssize_t k;
+ unsigned j;
+ sd_id128_t t;
+ char *p;
+
+ assert_return(ret, -EINVAL);
+
+ if (saved_boot_id_valid) {
+ *ret = saved_boot_id;
+ return 0;
+ }
+
+ fd = open("/proc/sys/kernel/random/boot_id", O_RDONLY|O_CLOEXEC|O_NOCTTY);
+ if (fd < 0)
+ return -errno;
+
+ k = loop_read(fd, buf, 36, false);
+ if (k < 0)
+ return (int) k;
+
+ if (k != 36)
+ return -EIO;
+
+ for (j = 0, p = buf; j < 16; j++) {
+ int a, b;
+
+ if (p >= buf + k)
+ return -EIO;
+
+ if (*p == '-')
+ p++;
+
+ a = unhexchar(p[0]);
+ b = unhexchar(p[1]);
+
+ if (a < 0 || b < 0)
+ return -EIO;
+
+ t.bytes[j] = a << 4 | b;
+
+ p += 2;
+ }
+
+ saved_boot_id = t;
+ saved_boot_id_valid = true;
+
+ *ret = t;
+ return 0;
+}
+
+_public_ int sd_id128_randomize(sd_id128_t *ret) {
+ _cleanup_close_ int fd = -1;
+ sd_id128_t t;
+ ssize_t k;
+
+ assert_return(ret, -EINVAL);
+
+ fd = open("/dev/urandom", O_RDONLY|O_CLOEXEC|O_NOCTTY);
+ if (fd < 0)
+ return -errno;
+
+ k = loop_read(fd, &t, 16, false);
+ if (k < 0)
+ return (int) k;
+
+ if (k != 16)
+ return -EIO;
+
+ /* Turn this into a valid v4 UUID, to be nice. Note that we
+ * only guarantee this for newly generated UUIDs, not for
+ * pre-existing ones.*/
+
+ *ret = make_v4_uuid(t);
+ return 0;
+}
~ianmdlvl / elogind.git / blobdiff