diff options
Diffstat (limited to 'src/libsystemd/src/sd-id128/sd-id128.c')
| -rw-r--r-- | src/libsystemd/src/sd-id128/sd-id128.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/src/libsystemd/src/sd-id128/sd-id128.c b/src/libsystemd/src/sd-id128/sd-id128.c new file mode 100644 index 0000000000..275949c651 --- /dev/null +++ b/src/libsystemd/src/sd-id128/sd-id128.c @@ -0,0 +1,184 @@ +/*** + 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 <systemd/sd-id128.h> + +#include "systemd-basic/fd-util.h" +#include "systemd-basic/hexdecoct.h" +#include "systemd-basic/io-util.h" +#include "systemd-basic/macro.h" +#include "systemd-basic/random-util.h" +#include "systemd-basic/util.h" + +#include "id128-util.h" + +_public_ char *sd_id128_to_string(sd_id128_t id, char s[SD_ID128_STRING_MAX]) { + 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); + + 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; + + if (ret) + *ret = t; + return 0; +} + +_public_ int sd_id128_get_machine(sd_id128_t *ret) { + static thread_local sd_id128_t saved_machine_id = {}; + int r; + + assert_return(ret, -EINVAL); + + if (sd_id128_is_null(saved_machine_id)) { + r = id128_read("/etc/machine-id", ID128_PLAIN, &saved_machine_id); + if (r < 0) + return r; + + if (sd_id128_is_null(saved_machine_id)) + return -EINVAL; + } + + *ret = saved_machine_id; + return 0; +} + +_public_ int sd_id128_get_boot(sd_id128_t *ret) { + static thread_local sd_id128_t saved_boot_id = {}; + int r; + + assert_return(ret, -EINVAL); + + if (sd_id128_is_null(saved_boot_id)) { + r = id128_read("/proc/sys/kernel/random/boot_id", ID128_UUID, &saved_boot_id); + if (r < 0) + return r; + } + + *ret = saved_boot_id; + return 0; +} + +_public_ int sd_id128_get_invocation(sd_id128_t *ret) { + static thread_local sd_id128_t saved_invocation_id = {}; + int r; + + assert_return(ret, -EINVAL); + + if (sd_id128_is_null(saved_invocation_id)) { + const char *e; + + e = secure_getenv("INVOCATION_ID"); + if (!e) + return -ENXIO; + + r = sd_id128_from_string(e, &saved_invocation_id); + if (r < 0) + return r; + } + + *ret = saved_invocation_id; + 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_randomize(sd_id128_t *ret) { + sd_id128_t t; + int r; + + assert_return(ret, -EINVAL); + + r = dev_urandom(&t, sizeof(t)); + if (r < 0) + return r; + + /* 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; +} |