c400d040ce
Fixes: #16506
299 lines
10 KiB
C
299 lines
10 KiB
C
/* SPDX-License-Identifier: LGPL-2.1+ */
|
|
|
|
#include <sched.h>
|
|
#include <sys/prctl.h>
|
|
#include <sys/stat.h>
|
|
#include <unistd.h>
|
|
|
|
#include "alloc-util.h"
|
|
#include "btrfs-util.h"
|
|
#include "capability-util.h"
|
|
#include "dirent-util.h"
|
|
#include "fd-util.h"
|
|
#include "fileio.h"
|
|
#include "fs-util.h"
|
|
#include "import-common.h"
|
|
#include "os-util.h"
|
|
#include "process-util.h"
|
|
#include "selinux-util.h"
|
|
#include "signal-util.h"
|
|
#include "tmpfile-util.h"
|
|
#include "util.h"
|
|
|
|
int import_make_read_only_fd(int fd) {
|
|
int r;
|
|
|
|
assert(fd >= 0);
|
|
|
|
/* First, let's make this a read-only subvolume if it refers
|
|
* to a subvolume */
|
|
r = btrfs_subvol_set_read_only_fd(fd, true);
|
|
if (IN_SET(r, -ENOTTY, -ENOTDIR, -EINVAL)) {
|
|
struct stat st;
|
|
|
|
/* This doesn't refer to a subvolume, or the file
|
|
* system isn't even btrfs. In that, case fall back to
|
|
* chmod()ing */
|
|
|
|
r = fstat(fd, &st);
|
|
if (r < 0)
|
|
return log_error_errno(errno, "Failed to stat temporary image: %m");
|
|
|
|
/* Drop "w" flag */
|
|
if (fchmod(fd, st.st_mode & 07555) < 0)
|
|
return log_error_errno(errno, "Failed to chmod() final image: %m");
|
|
|
|
return 0;
|
|
|
|
} else if (r < 0)
|
|
return log_error_errno(r, "Failed to make subvolume read-only: %m");
|
|
|
|
return 0;
|
|
}
|
|
|
|
int import_make_read_only(const char *path) {
|
|
_cleanup_close_ int fd = 1;
|
|
|
|
fd = open(path, O_RDONLY|O_NOCTTY|O_CLOEXEC);
|
|
if (fd < 0)
|
|
return log_error_errno(errno, "Failed to open %s: %m", path);
|
|
|
|
return import_make_read_only_fd(fd);
|
|
}
|
|
|
|
int import_fork_tar_x(const char *path, pid_t *ret) {
|
|
_cleanup_close_pair_ int pipefd[2] = { -1, -1 };
|
|
bool use_selinux;
|
|
pid_t pid;
|
|
int r;
|
|
|
|
assert(path);
|
|
assert(ret);
|
|
|
|
if (pipe2(pipefd, O_CLOEXEC) < 0)
|
|
return log_error_errno(errno, "Failed to create pipe for tar: %m");
|
|
|
|
use_selinux = mac_selinux_use();
|
|
|
|
r = safe_fork("(tar)", FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_LOG, &pid);
|
|
if (r < 0)
|
|
return r;
|
|
if (r == 0) {
|
|
const char *cmdline[] = {
|
|
"tar",
|
|
"--numeric-owner",
|
|
"-C", path,
|
|
"-px",
|
|
"--xattrs",
|
|
"--xattrs-include=*",
|
|
use_selinux ? "--selinux" : "--no-selinux",
|
|
NULL
|
|
};
|
|
|
|
uint64_t retain =
|
|
(1ULL << CAP_CHOWN) |
|
|
(1ULL << CAP_FOWNER) |
|
|
(1ULL << CAP_FSETID) |
|
|
(1ULL << CAP_MKNOD) |
|
|
(1ULL << CAP_SETFCAP) |
|
|
(1ULL << CAP_DAC_OVERRIDE);
|
|
|
|
/* Child */
|
|
|
|
pipefd[1] = safe_close(pipefd[1]);
|
|
|
|
r = rearrange_stdio(pipefd[0], -1, STDERR_FILENO);
|
|
if (r < 0) {
|
|
log_error_errno(r, "Failed to rearrange stdin/stdout: %m");
|
|
_exit(EXIT_FAILURE);
|
|
}
|
|
|
|
if (unshare(CLONE_NEWNET) < 0)
|
|
log_error_errno(errno, "Failed to lock tar into network namespace, ignoring: %m");
|
|
|
|
r = capability_bounding_set_drop(retain, true);
|
|
if (r < 0)
|
|
log_error_errno(r, "Failed to drop capabilities, ignoring: %m");
|
|
|
|
/* Try "gtar" before "tar". We only test things upstream with GNU tar. Some distros appear to
|
|
* install a different implementation as "tar" (in particular some that do not support the
|
|
* same command line switches), but then provide "gtar" as alias for the real thing, hence
|
|
* let's prefer that. (Yes, it's a bad idea they do that, given they don't provide equivalent
|
|
* command line support, but we are not here to argue, let's just expose the same
|
|
* behaviour/implementation everywhere.) */
|
|
execvp("gtar", (char* const*) cmdline);
|
|
execvp("tar", (char* const*) cmdline);
|
|
|
|
log_error_errno(errno, "Failed to execute tar: %m");
|
|
_exit(EXIT_FAILURE);
|
|
}
|
|
|
|
*ret = pid;
|
|
|
|
return TAKE_FD(pipefd[1]);
|
|
}
|
|
|
|
int import_fork_tar_c(const char *path, pid_t *ret) {
|
|
_cleanup_close_pair_ int pipefd[2] = { -1, -1 };
|
|
bool use_selinux;
|
|
pid_t pid;
|
|
int r;
|
|
|
|
assert(path);
|
|
assert(ret);
|
|
|
|
if (pipe2(pipefd, O_CLOEXEC) < 0)
|
|
return log_error_errno(errno, "Failed to create pipe for tar: %m");
|
|
|
|
use_selinux = mac_selinux_use();
|
|
|
|
r = safe_fork("(tar)", FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_LOG, &pid);
|
|
if (r < 0)
|
|
return r;
|
|
if (r == 0) {
|
|
const char *cmdline[] = {
|
|
"tar",
|
|
"-C", path,
|
|
"-c",
|
|
"--xattrs",
|
|
"--xattrs-include=*",
|
|
use_selinux ? "--selinux" : "--no-selinux",
|
|
".",
|
|
NULL
|
|
};
|
|
|
|
uint64_t retain = (1ULL << CAP_DAC_OVERRIDE);
|
|
|
|
/* Child */
|
|
|
|
pipefd[0] = safe_close(pipefd[0]);
|
|
|
|
r = rearrange_stdio(-1, pipefd[1], STDERR_FILENO);
|
|
if (r < 0) {
|
|
log_error_errno(r, "Failed to rearrange stdin/stdout: %m");
|
|
_exit(EXIT_FAILURE);
|
|
}
|
|
|
|
if (unshare(CLONE_NEWNET) < 0)
|
|
log_error_errno(errno, "Failed to lock tar into network namespace, ignoring: %m");
|
|
|
|
r = capability_bounding_set_drop(retain, true);
|
|
if (r < 0)
|
|
log_error_errno(r, "Failed to drop capabilities, ignoring: %m");
|
|
|
|
execvp("gtar", (char* const*) cmdline);
|
|
execvp("tar", (char* const*) cmdline);
|
|
|
|
log_error_errno(errno, "Failed to execute tar: %m");
|
|
_exit(EXIT_FAILURE);
|
|
}
|
|
|
|
*ret = pid;
|
|
|
|
return TAKE_FD(pipefd[0]);
|
|
}
|
|
|
|
int import_mangle_os_tree(const char *path) {
|
|
_cleanup_closedir_ DIR *d = NULL, *cd = NULL;
|
|
_cleanup_free_ char *child = NULL, *t = NULL;
|
|
const char *joined;
|
|
struct dirent *de;
|
|
int r;
|
|
|
|
assert(path);
|
|
|
|
/* Some tarballs contain a single top-level directory that contains the actual OS directory tree. Try to
|
|
* recognize this, and move the tree one level up. */
|
|
|
|
r = path_is_os_tree(path);
|
|
if (r < 0)
|
|
return log_error_errno(r, "Failed to determine whether '%s' is an OS tree: %m", path);
|
|
if (r > 0) {
|
|
log_debug("Directory tree '%s' is a valid OS tree.", path);
|
|
return 0;
|
|
}
|
|
|
|
log_debug("Directory tree '%s' is not recognizable as OS tree, checking whether to rearrange it.", path);
|
|
|
|
d = opendir(path);
|
|
if (!d)
|
|
return log_error_errno(r, "Failed to open directory '%s': %m", path);
|
|
|
|
errno = 0;
|
|
de = readdir_no_dot(d);
|
|
if (!de) {
|
|
if (errno != 0)
|
|
return log_error_errno(errno, "Failed to iterate through directory '%s': %m", path);
|
|
|
|
log_debug("Directory '%s' is empty, leaving it as it is.", path);
|
|
return 0;
|
|
}
|
|
|
|
child = strdup(de->d_name);
|
|
if (!child)
|
|
return log_oom();
|
|
|
|
errno = 0;
|
|
de = readdir_no_dot(d);
|
|
if (de) {
|
|
if (errno != 0)
|
|
return log_error_errno(errno, "Failed to iterate through directory '%s': %m", path);
|
|
|
|
log_debug("Directory '%s' does not look like a directory tree, and has multiple children, leaving as it is.", path);
|
|
return 0;
|
|
}
|
|
|
|
joined = prefix_roota(path, child);
|
|
r = path_is_os_tree(joined);
|
|
if (r == -ENOTDIR) {
|
|
log_debug("Directory '%s' does not look like a directory tree, and contains a single regular file only, leaving as it is.", path);
|
|
return 0;
|
|
}
|
|
if (r < 0)
|
|
return log_error_errno(r, "Failed to determine whether '%s' is an OS tree: %m", joined);
|
|
if (r == 0) {
|
|
log_debug("Neither '%s' nor '%s' is a valid OS tree, leaving them as they are.", path, joined);
|
|
return 0;
|
|
}
|
|
|
|
/* Nice, we have checked now:
|
|
*
|
|
* 1. The top-level directory does not qualify as OS tree
|
|
* 1. The top-level directory only contains one item
|
|
* 2. That item is a directory
|
|
* 3. And that directory qualifies as OS tree
|
|
*
|
|
* Let's now rearrange things, moving everything in the inner directory one level up */
|
|
|
|
cd = xopendirat(dirfd(d), child, O_NOFOLLOW);
|
|
if (!cd)
|
|
return log_error_errno(errno, "Can't open directory '%s': %m", joined);
|
|
|
|
log_info("Rearranging '%s', moving OS tree one directory up.", joined);
|
|
|
|
/* Let's rename the child to an unguessable name so that we can be sure all files contained in it can be
|
|
* safely moved up and won't collide with the name. */
|
|
r = tempfn_random(child, NULL, &t);
|
|
if (r < 0)
|
|
return log_oom();
|
|
r = rename_noreplace(dirfd(d), child, dirfd(d), t);
|
|
if (r < 0)
|
|
return log_error_errno(r, "Unable to rename '%s' to '%s/%s': %m", joined, path, t);
|
|
|
|
FOREACH_DIRENT_ALL(de, cd, return log_error_errno(errno, "Failed to iterate through directory '%s': %m", joined)) {
|
|
if (dot_or_dot_dot(de->d_name))
|
|
continue;
|
|
|
|
r = rename_noreplace(dirfd(cd), de->d_name, dirfd(d), de->d_name);
|
|
if (r < 0)
|
|
return log_error_errno(r, "Unable to move '%s/%s/%s' to '%s/%s': %m", path, t, de->d_name, path, de->d_name);
|
|
}
|
|
|
|
if (unlinkat(dirfd(d), t, AT_REMOVEDIR) < 0)
|
|
return log_error_errno(errno, "Failed to remove temporary directory '%s/%s': %m", path, t);
|
|
|
|
log_info("Successfully rearranged OS tree.");
|
|
|
|
return 0;
|
|
}
|