Systemd/src/machine/image-dbus.c

587 lines
18 KiB
C

/***
This file is part of systemd.
Copyright 2014 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 <sys/mount.h>
#include "alloc-util.h"
#include "bus-label.h"
#include "bus-util.h"
#include "copy.h"
#include "dissect-image.h"
#include "fd-util.h"
#include "fileio.h"
#include "fs-util.h"
#include "image-dbus.h"
#include "io-util.h"
#include "loop-util.h"
#include "machine-image.h"
#include "mount-util.h"
#include "process-util.h"
#include "raw-clone.h"
#include "strv.h"
#include "user-util.h"
static BUS_DEFINE_PROPERTY_GET_ENUM(property_get_type, image_type, ImageType);
int bus_image_method_remove(
sd_bus_message *message,
void *userdata,
sd_bus_error *error) {
_cleanup_close_pair_ int errno_pipe_fd[2] = { -1, -1 };
Image *image = userdata;
Manager *m = image->userdata;
pid_t child;
int r;
assert(message);
assert(image);
if (m->n_operations >= OPERATIONS_MAX)
return sd_bus_error_setf(error, SD_BUS_ERROR_LIMITS_EXCEEDED, "Too many ongoing operations.");
r = bus_verify_polkit_async(
message,
CAP_SYS_ADMIN,
"org.freedesktop.machine1.manage-images",
NULL,
false,
UID_INVALID,
&m->polkit_registry,
error);
if (r < 0)
return r;
if (r == 0)
return 1; /* Will call us back */
if (pipe2(errno_pipe_fd, O_CLOEXEC|O_NONBLOCK) < 0)
return sd_bus_error_set_errnof(error, errno, "Failed to create pipe: %m");
child = fork();
if (child < 0)
return sd_bus_error_set_errnof(error, errno, "Failed to fork(): %m");
if (child == 0) {
errno_pipe_fd[0] = safe_close(errno_pipe_fd[0]);
r = image_remove(image);
if (r < 0) {
(void) write(errno_pipe_fd[1], &r, sizeof(r));
_exit(EXIT_FAILURE);
}
_exit(EXIT_SUCCESS);
}
errno_pipe_fd[1] = safe_close(errno_pipe_fd[1]);
r = operation_new(m, NULL, child, message, errno_pipe_fd[0], NULL);
if (r < 0) {
(void) sigkill_wait(child);
return r;
}
errno_pipe_fd[0] = -1;
return 1;
}
int bus_image_method_rename(
sd_bus_message *message,
void *userdata,
sd_bus_error *error) {
Image *image = userdata;
Manager *m = image->userdata;
const char *new_name;
int r;
assert(message);
assert(image);
r = sd_bus_message_read(message, "s", &new_name);
if (r < 0)
return r;
if (!image_name_is_valid(new_name))
return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Image name '%s' is invalid.", new_name);
r = bus_verify_polkit_async(
message,
CAP_SYS_ADMIN,
"org.freedesktop.machine1.manage-images",
NULL,
false,
UID_INVALID,
&m->polkit_registry,
error);
if (r < 0)
return r;
if (r == 0)
return 1; /* Will call us back */
r = image_rename(image, new_name);
if (r < 0)
return r;
return sd_bus_reply_method_return(message, NULL);
}
int bus_image_method_clone(
sd_bus_message *message,
void *userdata,
sd_bus_error *error) {
_cleanup_close_pair_ int errno_pipe_fd[2] = { -1, -1 };
Image *image = userdata;
Manager *m = image->userdata;
const char *new_name;
int r, read_only;
pid_t child;
assert(message);
assert(image);
assert(m);
if (m->n_operations >= OPERATIONS_MAX)
return sd_bus_error_setf(error, SD_BUS_ERROR_LIMITS_EXCEEDED, "Too many ongoing operations.");
r = sd_bus_message_read(message, "sb", &new_name, &read_only);
if (r < 0)
return r;
if (!image_name_is_valid(new_name))
return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Image name '%s' is invalid.", new_name);
r = bus_verify_polkit_async(
message,
CAP_SYS_ADMIN,
"org.freedesktop.machine1.manage-images",
NULL,
false,
UID_INVALID,
&m->polkit_registry,
error);
if (r < 0)
return r;
if (r == 0)
return 1; /* Will call us back */
if (pipe2(errno_pipe_fd, O_CLOEXEC|O_NONBLOCK) < 0)
return sd_bus_error_set_errnof(error, errno, "Failed to create pipe: %m");
child = fork();
if (child < 0)
return sd_bus_error_set_errnof(error, errno, "Failed to fork(): %m");
if (child == 0) {
errno_pipe_fd[0] = safe_close(errno_pipe_fd[0]);
r = image_clone(image, new_name, read_only);
if (r < 0) {
(void) write(errno_pipe_fd[1], &r, sizeof(r));
_exit(EXIT_FAILURE);
}
_exit(EXIT_SUCCESS);
}
errno_pipe_fd[1] = safe_close(errno_pipe_fd[1]);
r = operation_new(m, NULL, child, message, errno_pipe_fd[0], NULL);
if (r < 0) {
(void) sigkill_wait(child);
return r;
}
errno_pipe_fd[0] = -1;
return 1;
}
int bus_image_method_mark_read_only(
sd_bus_message *message,
void *userdata,
sd_bus_error *error) {
Image *image = userdata;
Manager *m = image->userdata;
int r, read_only;
assert(message);
r = sd_bus_message_read(message, "b", &read_only);
if (r < 0)
return r;
r = bus_verify_polkit_async(
message,
CAP_SYS_ADMIN,
"org.freedesktop.machine1.manage-images",
NULL,
false,
UID_INVALID,
&m->polkit_registry,
error);
if (r < 0)
return r;
if (r == 0)
return 1; /* Will call us back */
r = image_read_only(image, read_only);
if (r < 0)
return r;
return sd_bus_reply_method_return(message, NULL);
}
int bus_image_method_set_limit(
sd_bus_message *message,
void *userdata,
sd_bus_error *error) {
Image *image = userdata;
Manager *m = image->userdata;
uint64_t limit;
int r;
assert(message);
r = sd_bus_message_read(message, "t", &limit);
if (r < 0)
return r;
if (!FILE_SIZE_VALID_OR_INFINITY(limit))
return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "New limit out of range");
r = bus_verify_polkit_async(
message,
CAP_SYS_ADMIN,
"org.freedesktop.machine1.manage-images",
NULL,
false,
UID_INVALID,
&m->polkit_registry,
error);
if (r < 0)
return r;
if (r == 0)
return 1; /* Will call us back */
r = image_set_limit(image, limit);
if (r < 0)
return r;
return sd_bus_reply_method_return(message, NULL);
}
#define EXIT_NOT_FOUND 2
static int directory_image_get_os_release(Image *image, char ***ret, sd_bus_error *error) {
_cleanup_free_ char *path = NULL;
int r;
assert(image);
assert(ret);
r = chase_symlinks("/etc/os-release", image->path, CHASE_PREFIX_ROOT, &path);
if (r == -ENOENT)
r = chase_symlinks("/usr/lib/os-release", image->path, CHASE_PREFIX_ROOT, &path);
if (r == -ENOENT)
return sd_bus_error_setf(error, SD_BUS_ERROR_FAILED, "Image does not contain OS release information");
if (r < 0)
return sd_bus_error_set_errnof(error, r, "Failed to resolve %s: %m", image->path);
r = load_env_file_pairs(NULL, path, NULL, ret);
if (r < 0)
return sd_bus_error_set_errnof(error, r, "Failed to open %s: %m", path);
return 0;
}
static int raw_image_get_os_release(Image *image, char ***ret, sd_bus_error *error) {
_cleanup_(rmdir_and_freep) char *t = NULL;
_cleanup_(loop_device_unrefp) LoopDevice *d = NULL;
_cleanup_(dissected_image_unrefp) DissectedImage *m = NULL;
_cleanup_(sigkill_waitp) pid_t child = 0;
_cleanup_close_pair_ int pair[2] = { -1, -1 };
_cleanup_fclose_ FILE *f = NULL;
_cleanup_strv_free_ char **v = NULL;
siginfo_t si;
int r;
assert(image);
assert(ret);
r = mkdtemp_malloc("/tmp/machined-root-XXXXXX", &t);
if (r < 0)
return sd_bus_error_set_errnof(error, r, "Failed to create temporary directory: %m");
r = loop_device_make_by_path(image->path, O_RDONLY, &d);
if (r < 0)
return sd_bus_error_set_errnof(error, r, "Failed to set up loop block device for %s: %m", image->path);
r = dissect_image(d->fd, NULL, 0, DISSECT_IMAGE_REQUIRE_ROOT, &m);
if (r == -ENOPKG)
return sd_bus_error_set_errnof(error, r, "Disk image %s not understood: %m", image->path);
if (r < 0)
return sd_bus_error_set_errnof(error, r, "Failed to dissect image %s: %m", image->path);
if (pipe2(pair, O_CLOEXEC) < 0)
return sd_bus_error_set_errnof(error, errno, "Failed to create communication pipe: %m");
child = raw_clone(SIGCHLD|CLONE_NEWNS);
if (child < 0)
return sd_bus_error_set_errnof(error, errno, "Failed to fork(): %m");
if (child == 0) {
int fd;
pair[0] = safe_close(pair[0]);
/* Make sure we never propagate to the host */
if (mount(NULL, "/", NULL, MS_SLAVE | MS_REC, NULL) < 0)
_exit(EXIT_FAILURE);
r = dissected_image_mount(m, t, DISSECT_IMAGE_READ_ONLY);
if (r < 0)
_exit(EXIT_FAILURE);
r = mount_move_root(t);
if (r < 0)
_exit(EXIT_FAILURE);
fd = open("/etc/os-release", O_RDONLY|O_CLOEXEC|O_NOCTTY);
if (fd < 0 && errno == ENOENT) {
fd = open("/usr/lib/os-release", O_RDONLY|O_CLOEXEC|O_NOCTTY);
if (fd < 0 && errno == ENOENT)
_exit(EXIT_NOT_FOUND);
}
if (fd < 0)
_exit(EXIT_FAILURE);
r = copy_bytes(fd, pair[1], (uint64_t) -1, false);
if (r < 0)
_exit(EXIT_FAILURE);
_exit(EXIT_SUCCESS);
}
pair[1] = safe_close(pair[1]);
f = fdopen(pair[0], "re");
if (!f)
return -errno;
pair[0] = -1;
r = load_env_file_pairs(f, "os-release", NULL, &v);
if (r < 0)
return r;
r = wait_for_terminate(child, &si);
if (r < 0)
return sd_bus_error_set_errnof(error, r, "Failed to wait for child: %m");
child = 0;
if (si.si_code == CLD_EXITED && si.si_status == EXIT_NOT_FOUND)
return sd_bus_error_setf(error, SD_BUS_ERROR_FAILED, "Image does not contain OS release information");
if (si.si_code != CLD_EXITED || si.si_status != EXIT_SUCCESS)
return sd_bus_error_setf(error, SD_BUS_ERROR_FAILED, "Child died abnormally.");
*ret = v;
v = NULL;
return 0;
}
int bus_image_method_get_os_release(
sd_bus_message *message,
void *userdata,
sd_bus_error *error) {
_cleanup_release_lock_file_ LockFile tree_global_lock = LOCK_FILE_INIT, tree_local_lock = LOCK_FILE_INIT;
_cleanup_strv_free_ char **v = NULL;
Image *image = userdata;
int r;
r = image_path_lock(image->path, LOCK_SH|LOCK_NB, &tree_global_lock, &tree_local_lock);
if (r < 0)
return sd_bus_error_set_errnof(error, r, "Failed to lock image: %m");
switch (image->type) {
case IMAGE_DIRECTORY:
case IMAGE_SUBVOLUME:
r = directory_image_get_os_release(image, &v, error);
break;
case IMAGE_RAW:
r = raw_image_get_os_release(image, &v, error);
break;
default:
assert_not_reached("Unknown image type");
}
if (r < 0)
return r;
return bus_reply_pair_array(message, v);
}
const sd_bus_vtable image_vtable[] = {
SD_BUS_VTABLE_START(0),
SD_BUS_PROPERTY("Name", "s", NULL, offsetof(Image, name), 0),
SD_BUS_PROPERTY("Path", "s", NULL, offsetof(Image, path), 0),
SD_BUS_PROPERTY("Type", "s", property_get_type, offsetof(Image, type), 0),
SD_BUS_PROPERTY("ReadOnly", "b", bus_property_get_bool, offsetof(Image, read_only), 0),
SD_BUS_PROPERTY("CreationTimestamp", "t", NULL, offsetof(Image, crtime), 0),
SD_BUS_PROPERTY("ModificationTimestamp", "t", NULL, offsetof(Image, mtime), 0),
SD_BUS_PROPERTY("Usage", "t", NULL, offsetof(Image, usage), 0),
SD_BUS_PROPERTY("Limit", "t", NULL, offsetof(Image, limit), 0),
SD_BUS_PROPERTY("UsageExclusive", "t", NULL, offsetof(Image, usage_exclusive), 0),
SD_BUS_PROPERTY("LimitExclusive", "t", NULL, offsetof(Image, limit_exclusive), 0),
SD_BUS_METHOD("Remove", NULL, NULL, bus_image_method_remove, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_METHOD("Rename", "s", NULL, bus_image_method_rename, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_METHOD("Clone", "sb", NULL, bus_image_method_clone, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_METHOD("MarkReadOnly", "b", NULL, bus_image_method_mark_read_only, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_METHOD("SetLimit", "t", NULL, bus_image_method_set_limit, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_METHOD("GetOSRelease", NULL, "a{ss}", bus_image_method_get_os_release, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_VTABLE_END
};
static int image_flush_cache(sd_event_source *s, void *userdata) {
Manager *m = userdata;
Image *i;
assert(s);
assert(m);
while ((i = hashmap_steal_first(m->image_cache)))
image_unref(i);
return 0;
}
int image_object_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error) {
_cleanup_free_ char *e = NULL;
Manager *m = userdata;
Image *image = NULL;
const char *p;
int r;
assert(bus);
assert(path);
assert(interface);
assert(found);
p = startswith(path, "/org/freedesktop/machine1/image/");
if (!p)
return 0;
e = bus_label_unescape(p);
if (!e)
return -ENOMEM;
image = hashmap_get(m->image_cache, e);
if (image) {
*found = image;
return 1;
}
r = hashmap_ensure_allocated(&m->image_cache, &string_hash_ops);
if (r < 0)
return r;
if (!m->image_cache_defer_event) {
r = sd_event_add_defer(m->event, &m->image_cache_defer_event, image_flush_cache, m);
if (r < 0)
return r;
r = sd_event_source_set_priority(m->image_cache_defer_event, SD_EVENT_PRIORITY_IDLE);
if (r < 0)
return r;
}
r = sd_event_source_set_enabled(m->image_cache_defer_event, SD_EVENT_ONESHOT);
if (r < 0)
return r;
r = image_find(e, &image);
if (r <= 0)
return r;
image->userdata = m;
r = hashmap_put(m->image_cache, image->name, image);
if (r < 0) {
image_unref(image);
return r;
}
*found = image;
return 1;
}
char *image_bus_path(const char *name) {
_cleanup_free_ char *e = NULL;
assert(name);
e = bus_label_escape(name);
if (!e)
return NULL;
return strappend("/org/freedesktop/machine1/image/", e);
}
int image_node_enumerator(sd_bus *bus, const char *path, void *userdata, char ***nodes, sd_bus_error *error) {
_cleanup_(image_hashmap_freep) Hashmap *images = NULL;
_cleanup_strv_free_ char **l = NULL;
Image *image;
Iterator i;
int r;
assert(bus);
assert(path);
assert(nodes);
images = hashmap_new(&string_hash_ops);
if (!images)
return -ENOMEM;
r = image_discover(images);
if (r < 0)
return r;
HASHMAP_FOREACH(image, images, i) {
char *p;
p = image_bus_path(image->name);
if (!p)
return -ENOMEM;
r = strv_consume(&l, p);
if (r < 0)
return r;
}
*nodes = l;
l = NULL;
return 1;
}