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-rw-r--r--src/import/import-common.c259
1 files changed, 259 insertions, 0 deletions
diff --git a/src/import/import-common.c b/src/import/import-common.c
new file mode 100644
index 0000000..89f0301
--- /dev/null
+++ b/src/import/import-common.c
@@ -0,0 +1,259 @@
+/* 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 "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 };
+ 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");
+
+ r = safe_fork("(tar)", FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_LOG, &pid);
+ if (r < 0)
+ return r;
+ if (r == 0) {
+ 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");
+
+ execlp("tar", "tar", "--numeric-owner", "-C", path, "-px", "--xattrs", "--xattrs-include=*", NULL);
+ 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 };
+ 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");
+
+ r = safe_fork("(tar)", FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_LOG, &pid);
+ if (r < 0)
+ return r;
+ if (r == 0) {
+ 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");
+
+ execlp("tar", "tar", "-C", path, "-c", "--xattrs", "--xattrs-include=*", ".", NULL);
+ 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 = strjoina(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;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-08-13 12:49:03 +0000