diff options
Diffstat (limited to 'src/core/machine-id-setup.c')
| -rw-r--r-- | src/core/machine-id-setup.c | 361 |
1 files changed, 0 insertions, 361 deletions
diff --git a/src/core/machine-id-setup.c b/src/core/machine-id-setup.c deleted file mode 100644 index 7505dcbcaa..0000000000 --- a/src/core/machine-id-setup.c +++ /dev/null @@ -1,361 +0,0 @@ -/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ - -/*** - This file is part of systemd. - - 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 <unistd.h> -#include <stdio.h> -#include <errno.h> -#include <string.h> -#include <fcntl.h> -#include <sys/mount.h> - -#include "systemd/sd-id128.h" - -#include "machine-id-setup.h" -#include "macro.h" -#include "util.h" -#include "mkdir.h" -#include "log.h" -#include "virt.h" -#include "fileio.h" -#include "path-util.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, char id[34]) { - assert(fd >= 0); - assert(id); - - if (lseek(fd, 0, SEEK_SET) < 0) - return -errno; - - return loop_write(fd, id, 33, false); -} - -static int generate_machine_id(char id[34], const char *root) { - int fd, r; - unsigned char *p; - sd_id128_t buf; - char *q; - const char *vm_id, *dbus_machine_id; - - assert(id); - - if (isempty(root)) - dbus_machine_id = "/var/lib/dbus/machine-id"; - else - dbus_machine_id = strjoina(root, "/var/lib/dbus/machine-id"); - - /* First, try reading the D-Bus machine id, unless it is a symlink */ - 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) { - log_info("Initializing machine ID from D-Bus machine ID."); - return 0; - } - } - - if (isempty(root)) { - /* If that didn't work, see if we are running in a container, - * and a machine ID was passed in via $container_uuid the way - * libvirt/LXC does it */ - r = detect_container(NULL); - if (r > 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; - } - } - - } else { - /* If we are not running in a container, see if we are - * running in qemu/kvm and a machine ID was passed in - * via -uuid on the qemu/kvm command line */ - - r = detect_vm(&vm_id); - if (r > 0 && streq(vm_id, "kvm")) { - 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 that didn't work, generate a random machine id */ - r = sd_id128_randomize(&buf); - 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; - - log_info("Initializing machine ID from random generator."); - - return 0; -} - -int machine_id_setup(const char *root) { - const char *etc_machine_id, *run_machine_id; - _cleanup_close_ int fd = -1; - bool writable = true; - char id[34]; /* 32 + \n + \0 */ - int r; - - if (isempty(root)) { - etc_machine_id = "/etc/machine-id"; - run_machine_id = "/run/machine-id"; - } else { - char *x; - - x = strjoina(root, "/etc/machine-id"); - etc_machine_id = path_kill_slashes(x); - - x = strjoina(root, "/run/machine-id"); - run_machine_id = path_kill_slashes(x); - } - - RUN_WITH_UMASK(0000) { - /* We create this 0444, to indicate that this isn't really - * something you should ever modify. Of course, since the file - * will be owned by root it doesn't matter much, but maybe - * people look. */ - - 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, - "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; - } - - writable = false; - } - } - - if (read_machine_id(fd, id) >= 0) - return 0; - - /* Hmm, so, the id currently stored is not useful, then let's - * generate one */ - - r = generate_machine_id(id, root); - if (r < 0) - return r; - - if (writable) - if (write_machine_id(fd, id) >= 0) - return 0; - - fd = safe_close(fd); - - /* 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); - } - 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 */ - if (mount(run_machine_id, etc_machine_id, NULL, MS_BIND, NULL) < 0) { - (void) unlink_noerrno(run_machine_id); - return log_error_errno(errno, "Failed to mount %s: %m", etc_machine_id); - } - - log_info("Installed transient %s file.", etc_machine_id); - - /* 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); - - return 0; -} - -int machine_id_commit(const char *root) { - _cleanup_close_ int fd = -1, initial_mntns_fd = -1; - const char *etc_machine_id; - char id[34]; /* 32 + \n + \0 */ - int r; - - if (isempty(root)) - etc_machine_id = "/etc/machine-id"; - else { - char *x; - - x = strjoina(root, "/etc/machine-id"); - etc_machine_id = path_kill_slashes(x); - } - - r = path_is_mount_point(etc_machine_id, false); - if (r < 0) - return log_error_errno(r, "Failed to determine whether %s is a mount point: %m", etc_machine_id); - if (r == 0) { - log_debug("%s is is not a mount point. Nothing to do.", etc_machine_id); - return 0; - } - - /* Read existing machine-id */ - fd = open(etc_machine_id, O_RDONLY|O_CLOEXEC|O_NOCTTY); - if (fd < 0) - return log_error_errno(errno, "Cannot open %s: %m", etc_machine_id); - - r = read_machine_id(fd, id); - if (r < 0) - return log_error_errno(r, "We didn't find a valid machine ID in %s.", etc_machine_id); - - r = is_fd_on_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; - } - - fd = safe_close(fd); - - /* Store current mount namespace */ - r = namespace_open(0, NULL, &initial_mntns_fd, NULL, NULL); - if (r < 0) - return log_error_errno(r, "Can't fetch current mount namespace: %m"); - - /* Switch to a new mount namespace, isolate ourself and unmount etc_machine_id in our new namespace */ - if (unshare(CLONE_NEWNS) < 0) - return log_error_errno(errno, "Failed to enter new namespace: %m"); - - if (mount(NULL, "/", NULL, MS_SLAVE | MS_REC, NULL) < 0) - return log_error_errno(errno, "Couldn't make-rslave / mountpoint in our private namespace: %m"); - - if (umount(etc_machine_id) < 0) - return log_error_errno(errno, "Failed to unmount transient %s file in our private namespace: %m", etc_machine_id); - - /* Update a persistent version of etc_machine_id */ - fd = open(etc_machine_id, O_RDWR|O_CREAT|O_CLOEXEC|O_NOCTTY, 0444); - if (fd < 0) - return log_error_errno(errno, "Cannot open for writing %s. This is mandatory to get a persistent machine-id: %m", etc_machine_id); - - r = write_machine_id(fd, id); - if (r < 0) - return log_error_errno(r, "Cannot write %s: %m", etc_machine_id); - - fd = safe_close(fd); - - /* Return to initial namespace and proceed a lazy tmpfs unmount */ - r = namespace_enter(-1, initial_mntns_fd, -1, -1); - if (r < 0) - return log_warning_errno(r, "Failed to switch back to initial mount namespace: %m.\nWe'll keep transient %s file until next reboot.", etc_machine_id); - - if (umount2(etc_machine_id, MNT_DETACH) < 0) - return log_warning_errno(errno, "Failed to unmount transient %s file: %m.\nWe keep that mount until next reboot.", etc_machine_id); - - return 0; -} |