-/***
- This file is part of systemd.
+/* SPDX-License-Identifier: LGPL-2.1+ */
- Copyright 2010 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 <sched.h>
-#include <stdio.h>
-#include <string.h>
#include <sys/mount.h>
#include <unistd.h>
#include "alloc-util.h"
#include "fd-util.h"
-#include "fileio.h"
#include "fs-util.h"
-#include "hexdecoct.h"
#include "id128-util.h"
-#include "io-util.h"
#include "log.h"
#include "machine-id-setup.h"
#include "macro.h"
#include "util.h"
#include "virt.h"
-static int shorten_uuid(char destination[34], const char source[36]) {
- unsigned i, j;
-
- assert(destination);
- assert(source);
-
- /* Converts a UUID into a machine ID, by lowercasing it and
- * removing dashes. Validates everything. */
-
- for (i = 0, j = 0; i < 36 && j < 32; i++) {
- int t;
-
- t = unhexchar(source[i]);
- if (t < 0)
- continue;
-
- destination[j++] = hexchar(t);
- }
-
- if (i != 36 || j != 32)
- return -EINVAL;
-
- destination[32] = '\n';
- destination[33] = 0;
- return 0;
-}
-
-static int read_machine_id(int fd, char id[34]) {
- char id_to_validate[34];
- int r;
-
- assert(fd >= 0);
- assert(id);
-
- /* Reads a machine ID from a file, validates it, and returns
- * it. The returned ID ends in a newline. */
-
- r = loop_read_exact(fd, id_to_validate, 33, false);
- if (r < 0)
- return r;
-
- if (id_to_validate[32] != '\n')
- return -EINVAL;
-
- id_to_validate[32] = 0;
-
- if (!id128_is_valid(id_to_validate))
- return -EINVAL;
-
- memcpy(id, id_to_validate, 32);
- id[32] = '\n';
- id[33] = 0;
- return 0;
-}
-
-static int write_machine_id(int fd, const char id[34]) {
- int r;
-
- assert(fd >= 0);
- assert(id);
-
- if (lseek(fd, 0, SEEK_SET) < 0)
- return -errno;
-
- r = loop_write(fd, id, 33, false);
- if (r < 0)
- return r;
-
- if (fsync(fd) < 0)
- return -errno;
-
- return 0;
-}
-
-static int generate_machine_id(char id[34], const char *root) {
- int fd, r;
- unsigned char *p;
- sd_id128_t buf;
- char *q;
+static int generate_machine_id(const char *root, sd_id128_t *ret) {
const char *dbus_machine_id;
+ _cleanup_close_ int fd = -1;
+ int r;
- assert(id);
-
- dbus_machine_id = prefix_roota(root, "/var/lib/dbus/machine-id");
+ assert(ret);
/* First, try reading the D-Bus machine id, unless it is a symlink */
+ dbus_machine_id = prefix_roota(root, "/var/lib/dbus/machine-id");
fd = open(dbus_machine_id, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
if (fd >= 0) {
- r = read_machine_id(fd, id);
- safe_close(fd);
-
- if (r >= 0) {
+ if (id128_read_fd(fd, ID128_PLAIN, ret) >= 0) {
log_info("Initializing machine ID from D-Bus machine ID.");
return 0;
}
+
+ fd = safe_close(fd);
}
if (isempty(root)) {
if (detect_container() > 0) {
_cleanup_free_ char *e = NULL;
- r = getenv_for_pid(1, "container_uuid", &e);
- if (r > 0) {
- r = shorten_uuid(id, e);
- if (r >= 0) {
- log_info("Initializing machine ID from container UUID.");
- return 0;
- }
+ if (getenv_for_pid(1, "container_uuid", &e) > 0 &&
+ sd_id128_from_string(e, ret) >= 0) {
+ log_info("Initializing machine ID from container UUID.");
+ return 0;
}
} else if (detect_vm() == VIRTUALIZATION_KVM) {
* running in qemu/kvm and a machine ID was passed in
* via -uuid on the qemu/kvm command line */
- char uuid[36];
-
- fd = open("/sys/class/dmi/id/product_uuid", O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);
- if (fd >= 0) {
- r = loop_read_exact(fd, uuid, 36, false);
- safe_close(fd);
-
- if (r >= 0) {
- r = shorten_uuid(id, uuid);
- if (r >= 0) {
- log_info("Initializing machine ID from KVM UUID.");
- return 0;
- }
- }
+ if (id128_read("/sys/class/dmi/id/product_uuid", ID128_UUID, ret) >= 0) {
+ log_info("Initializing machine ID from KVM UUID.");
+ return 0;
}
}
}
/* If that didn't work, generate a random machine id */
- r = sd_id128_randomize(&buf);
+ r = sd_id128_randomize(ret);
if (r < 0)
- return log_error_errno(r, "Failed to open /dev/urandom: %m");
-
- for (p = buf.bytes, q = id; p < buf.bytes + sizeof(buf); p++, q += 2) {
- q[0] = hexchar(*p >> 4);
- q[1] = hexchar(*p & 15);
- }
-
- id[32] = '\n';
- id[33] = 0;
+ return log_error_errno(r, "Failed to generate randomized machine ID: %m");
log_info("Initializing machine ID from random generator.");
-
return 0;
}
-int machine_id_setup(const char *root, sd_id128_t machine_id) {
+int machine_id_setup(const char *root, sd_id128_t machine_id, sd_id128_t *ret) {
const char *etc_machine_id, *run_machine_id;
_cleanup_close_ int fd = -1;
- bool writable = true;
- char id[34]; /* 32 + \n + \0 */
+ bool writable;
int r;
etc_machine_id = prefix_roota(root, "/etc/machine-id");
- run_machine_id = prefix_roota(root, "/run/machine-id");
RUN_WITH_UMASK(0000) {
/* We create this 0444, to indicate that this isn't really
* will be owned by root it doesn't matter much, but maybe
* people look. */
- mkdir_parents(etc_machine_id, 0755);
+ (void) mkdir_parents(etc_machine_id, 0755);
fd = open(etc_machine_id, O_RDWR|O_CREAT|O_CLOEXEC|O_NOCTTY, 0444);
if (fd < 0) {
int old_errno = errno;
fd = open(etc_machine_id, O_RDONLY|O_CLOEXEC|O_NOCTTY);
if (fd < 0) {
if (old_errno == EROFS && errno == ENOENT)
- log_error_errno(errno,
+ return log_error_errno(errno,
"System cannot boot: Missing /etc/machine-id and /etc is mounted read-only.\n"
"Booting up is supported only when:\n"
"1) /etc/machine-id exists and is populated.\n"
"2) /etc/machine-id exists and is empty.\n"
"3) /etc/machine-id is missing and /etc is writable.\n");
else
- log_error_errno(errno, "Cannot open %s: %m", etc_machine_id);
-
- return -errno;
+ return log_error_errno(errno, "Cannot open %s: %m", etc_machine_id);
}
writable = false;
- }
+ } else
+ writable = true;
}
- /* A machine id argument overrides all other machined-ids */
- if (!sd_id128_is_null(machine_id)) {
- sd_id128_to_string(machine_id, id);
- id[32] = '\n';
- id[33] = 0;
- } else {
- if (read_machine_id(fd, id) >= 0)
- return 0;
+ /* A we got a valid machine ID argument, that's what counts */
+ if (sd_id128_is_null(machine_id)) {
- /* Hmm, so, the id currently stored is not useful, then let's
- * generate one */
+ /* Try to read any existing machine ID */
+ if (id128_read_fd(fd, ID128_PLAIN, ret) >= 0)
+ return 0;
- r = generate_machine_id(id, root);
+ /* Hmm, so, the id currently stored is not useful, then let's generate one */
+ r = generate_machine_id(root, &machine_id);
if (r < 0)
return r;
}
- if (writable)
- if (write_machine_id(fd, id) >= 0)
- return 0;
+ if (writable) {
+ if (lseek(fd, 0, SEEK_SET) == (off_t) -1)
+ return log_error_errno(errno, "Failed to seek %s: %m", etc_machine_id);
+
+ if (ftruncate(fd, 0) < 0)
+ return log_error_errno(errno, "Failed to truncate %s: %m", etc_machine_id);
+
+ if (id128_write_fd(fd, ID128_PLAIN, machine_id, true) >= 0)
+ goto finish;
+ }
fd = safe_close(fd);
- /* Hmm, we couldn't write it? So let's write it to
- * /run/machine-id as a replacement */
+ /* Hmm, we couldn't write it? So let's write it to /run/machine-id as a replacement */
- RUN_WITH_UMASK(0022) {
- r = write_string_file(run_machine_id, id, WRITE_STRING_FILE_CREATE);
- if (r < 0) {
- (void) unlink(run_machine_id);
- return log_error_errno(r, "Cannot write %s: %m", run_machine_id);
- }
+ run_machine_id = prefix_roota(root, "/run/machine-id");
+
+ RUN_WITH_UMASK(0022)
+ r = id128_write(run_machine_id, ID128_PLAIN, machine_id, false);
+ if (r < 0) {
+ (void) unlink(run_machine_id);
+ return log_error_errno(r, "Cannot write %s: %m", run_machine_id);
}
/* And now, let's mount it over */
/* Mark the mount read-only */
if (mount(NULL, etc_machine_id, NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, NULL) < 0)
- log_warning_errno(errno, "Failed to make transient %s read-only: %m", etc_machine_id);
+ log_warning_errno(errno, "Failed to make transient %s read-only, ignoring: %m", etc_machine_id);
+
+finish:
+ if (ret)
+ *ret = machine_id;
return 0;
}
etc_machine_id = prefix_roota(root, "/etc/machine-id");
- r = path_is_mount_point(etc_machine_id, 0);
+ r = path_is_mount_point(etc_machine_id, NULL, 0);
if (r < 0)
return log_error_errno(r, "Failed to determine whether %s is a mount point: %m", etc_machine_id);
if (r == 0) {
r = fd_is_temporary_fs(fd);
if (r < 0)
return log_error_errno(r, "Failed to determine whether %s is on a temporary file system: %m", etc_machine_id);
- if (r == 0) {
- log_error("%s is not on a temporary file system.", etc_machine_id);
- return -EROFS;
- }
+ if (r == 0)
+ return log_error_errno(SYNTHETIC_ERRNO(EROFS),
+ "%s is not on a temporary file system.",
+ etc_machine_id);
r = id128_read_fd(fd, ID128_PLAIN, &id);
if (r < 0)
- return log_error_errno(r, "We didn't find a valid machine ID in %s.", etc_machine_id);
+ return log_error_errno(r, "We didn't find a valid machine ID in %s: %m", etc_machine_id);
fd = safe_close(fd);
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