--- /dev/null
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <fcntl.h>
+#include <getopt.h>
+#include <unistd.h>
+
+#include "argv-util.h"
+#include "build.h"
+#include "chase.h"
+#include "errno-util.h"
+#include "extract-word.h"
+#include "fd-util.h"
+#include "format-table.h"
+#include "image-policy.h"
+#include "main-func.h"
+#include "mount-util.h"
+#include "mountpoint-util.h"
+#include "mstack.h"
+#include "parse-argument.h"
+#include "pretty-print.h"
+#include "string-util.h"
+
+static enum {
+ ACTION_INSPECT,
+ ACTION_MOUNT,
+ ACTION_UMOUNT,
+} arg_action = ACTION_INSPECT;
+static char *arg_what = NULL;
+static char *arg_where = NULL;
+static sd_json_format_flags_t arg_json_format_flags = SD_JSON_FORMAT_OFF;
+static PagerFlags arg_pager_flags = 0;
+static int arg_legend = true;
+static MStackFlags arg_mstack_flags = 0;
+static bool arg_rmdir = false;
+static ImagePolicy *arg_image_policy = NULL;
+static ImageFilter *arg_image_filter = NULL;
+
+STATIC_DESTRUCTOR_REGISTER(arg_what, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_where, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_image_policy, image_policy_freep);
+STATIC_DESTRUCTOR_REGISTER(arg_image_filter, image_filter_freep);
+
+static int help(void) {
+ _cleanup_free_ char *link = NULL;
+ int r;
+
+ r = terminal_urlify_man("systemd-mstack", "1", &link);
+ if (r < 0)
+ return log_oom();
+
+ printf("%1$s [OPTIONS...] WHAT\n"
+ "%1$s [OPTIONS...] --mount WHAT WHERE\n"
+ "%1$s [OPTIONS...] --umount WHERE\n"
+ "\n%5$sInspect or apply mount stack.%6$s\n\n"
+ "%3$sOptions:%4$s\n"
+ " --no-pager Do not pipe output into a pager\n"
+ " --no-legend Do not print the column headers\n"
+ " --json=pretty|short|off Generate JSON output\n"
+ " -r --read-only Mount read-only\n"
+ " --mkdir Make mount directory before mounting, if missing\n"
+ " --rmdir Remove mount directory after unmounting\n"
+ " --image-policy=POLICY\n"
+ " Specify image dissection policy\n"
+ " --image-filter=FILTER\n"
+ " Specify image dissection filter\n"
+ "\n%3$sCommands:%4$s\n"
+ " -h --help Show this help\n"
+ " --version Show package version\n"
+ " -m --mount Mount the mstack to the specified directory\n"
+ " -M Shortcut for --mount --mkdir\n"
+ " -u --umount Unmount the image from the specified directory\n"
+ " -U Shortcut for --umount --rmdir\n"
+ "\nSee the %2$s for details.\n",
+ program_invocation_short_name,
+ link,
+ ansi_underline(), ansi_normal(),
+ ansi_highlight(), ansi_normal());
+
+ return 0;
+}
+
+static int parse_argv(int argc, char *argv[]) {
+
+ enum {
+ ARG_VERSION = 0x100,
+ ARG_NO_PAGER,
+ ARG_NO_LEGEND,
+ ARG_JSON,
+ ARG_MKDIR,
+ ARG_RMDIR,
+ ARG_IMAGE_POLICY,
+ ARG_IMAGE_FILTER,
+ };
+
+ static const struct option options[] = {
+ { "help", no_argument, NULL, 'h' },
+ { "version", no_argument, NULL, ARG_VERSION },
+ { "no-pager", no_argument, NULL, ARG_NO_PAGER },
+ { "no-legend", no_argument, NULL, ARG_NO_LEGEND },
+ { "mount", no_argument, NULL, 'm' },
+ { "umount", no_argument, NULL, 'u' },
+ { "json", required_argument, NULL, ARG_JSON },
+ { "read-only", no_argument, NULL, 'r' },
+ { "rmdir", no_argument, NULL, ARG_RMDIR },
+ { "image-policy", required_argument, NULL, ARG_IMAGE_POLICY },
+ { "image-filter", required_argument, NULL, ARG_IMAGE_FILTER },
+ {}
+ };
+
+ int c, r;
+
+ assert(argc >= 0);
+ assert(argv);
+
+ while ((c = getopt_long(argc, argv, "hmMuUr", options, NULL)) >= 0) {
+
+ switch (c) {
+
+ case 'h':
+ return help();
+
+ case ARG_VERSION:
+ return version();
+
+ case ARG_NO_PAGER:
+ arg_pager_flags |= PAGER_DISABLE;
+ break;
+
+ case ARG_NO_LEGEND:
+ arg_legend = false;
+ break;
+
+ case ARG_JSON:
+ r = parse_json_argument(optarg, &arg_json_format_flags);
+ if (r <= 0)
+ return r;
+
+ break;
+
+ case 'r':
+ arg_mstack_flags |= MSTACK_RDONLY;
+ break;
+
+ case ARG_IMAGE_POLICY:
+ r = parse_image_policy_argument(optarg, &arg_image_policy);
+ if (r < 0)
+ return r;
+ break;
+
+ case ARG_IMAGE_FILTER: {
+ _cleanup_(image_filter_freep) ImageFilter *f = NULL;
+ r = image_filter_parse(optarg, &f);
+ if (r < 0)
+ return log_error_errno(r, "Failed to parse image filter expression: %s", optarg);
+
+ image_filter_free(arg_image_filter);
+ arg_image_filter = TAKE_PTR(f);
+ break;
+ }
+
+ case ARG_MKDIR:
+ arg_mstack_flags |= MSTACK_MKDIR;
+ break;
+
+ case ARG_RMDIR:
+ arg_rmdir = true;
+ break;
+
+ case 'm':
+ arg_action = ACTION_MOUNT;
+ break;
+
+ case 'M':
+ /* Shortcut combination of --mkdir + --mount */
+ arg_action = ACTION_MOUNT;
+ arg_mstack_flags |= MSTACK_MKDIR;
+ break;
+
+ case 'u':
+ arg_action = ACTION_UMOUNT;
+ break;
+
+ case 'U':
+ /* Shortcut combination of --rmdir + --umount */
+ arg_action = ACTION_UMOUNT;
+ arg_rmdir = true;
+ break;
+
+ case '?':
+ return -EINVAL;
+
+ default:
+ assert_not_reached();
+ }
+ }
+
+ switch (arg_action) {
+
+ case ACTION_INSPECT:
+ if (optind + 1 != argc)
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Expected one argument.");
+
+ r = parse_path_argument(argv[optind], /* suppress_root= */ false, &arg_what);
+ if (r < 0)
+ return r;
+
+ break;
+
+ case ACTION_MOUNT:
+ if (optind + 2 != argc)
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Expected two arguments.");
+
+ r = parse_path_argument(argv[optind], /* suppress_root= */ false, &arg_what);
+ if (r < 0)
+ return r;
+
+ r = parse_path_argument(argv[optind+1], /* suppress_root= */ false, &arg_where);
+ if (r < 0)
+ return r;
+
+ break;
+
+ case ACTION_UMOUNT:
+ if (optind + 1 != argc)
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Expected one argument.");
+
+ r = parse_path_argument(argv[optind], /* suppress_root= */ false, &arg_where);
+ if (r < 0)
+ return r;
+
+ break;
+
+ default:
+ assert_not_reached();
+ }
+
+ return 1;
+}
+
+static int parse_argv_as_mount_helper(int argc, char *argv[]) {
+ const char *options = NULL;
+ bool fake = false;
+ int c, r;
+
+ /* Implements util-linux "external helper" command line interface, as per mount(8) man page. */
+
+ while ((c = getopt(argc, argv, "sfnvN:o:t:")) >= 0) {
+ switch (c) {
+
+ case 'f':
+ fake = true;
+ break;
+
+ case 'o':
+ options = optarg;
+ break;
+
+ case 't':
+ if (!streq(optarg, "mstack"))
+ log_debug("Unexpected file system type '%s', ignoring.", optarg);
+ break;
+
+ case 's': /* sloppy mount options */
+ case 'n': /* aka --no-mtab */
+ case 'v': /* aka --verbose */
+ log_debug("Ignoring option -%c, not implemented.", c);
+ break;
+
+ case 'N': /* aka --namespace= */
+ return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Option -%c is not implemented, refusing.", c);
+
+ case '?':
+ return -EINVAL;
+ }
+ }
+
+ if (optind + 2 != argc)
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+ "Expected an image file path and target directory as only argument.");
+
+ for (const char *p = options;;) {
+ _cleanup_free_ char *word = NULL;
+
+ r = extract_first_word(&p, &word, ",", EXTRACT_KEEP_QUOTE);
+ if (r < 0)
+ return log_error_errno(r, "Failed to extract mount option: %m");
+ if (r == 0)
+ break;
+
+ if (streq(word, "ro"))
+ SET_FLAG(arg_mstack_flags, MSTACK_RDONLY, true);
+ else if (streq(word, "rw"))
+ SET_FLAG(arg_mstack_flags, MSTACK_RDONLY, false);
+ else
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+ "Unknown mount option '%s'.", word);
+ }
+
+ if (fake)
+ return 0;
+
+ r = parse_path_argument(argv[optind], /* suppress_root= */ false, &arg_what);
+ if (r < 0)
+ return r;
+
+ r = parse_path_argument(argv[optind+1], /* suppress_root= */ false, &arg_where);
+ if (r < 0)
+ return r;
+
+ arg_action = ACTION_MOUNT;
+ return 1;
+}
+
+static int inspect_mstack(void) {
+ _cleanup_(mstack_freep) MStack *mstack = NULL;
+ int r;
+
+ assert(arg_what);
+
+ r = mstack_load(arg_what, /* dir_fd= */ -EBADF, &mstack);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to load .mstack/ directory '%s': %m", arg_what);
+
+ _cleanup_(table_unrefp) Table *t = NULL;
+
+ t = table_new("type", "name", "image", "what", "where", "sort");
+ if (!t)
+ return log_oom();
+
+ table_set_ersatz_string(t, TABLE_ERSATZ_DASH);
+
+ FOREACH_ARRAY(m, mstack->mounts, mstack->n_mounts) {
+ _cleanup_free_ char *w = NULL;
+ r = fd_get_path(m->what_fd, &w);
+ if (r < 0)
+ return log_error_errno(r, "Failed to get path of what file descriptor: %m");
+
+ r = table_add_many(
+ t,
+ TABLE_STRING, mstack_mount_type_to_string(m->mount_type),
+ TABLE_STRING, m->what,
+ TABLE_STRING, image_type_to_string(m->image_type),
+ TABLE_PATH, w,
+ TABLE_PATH, m->where ?: ((mstack->root_mount && mstack->root_mount != m) ? "/usr" : "/"),
+ TABLE_STRING, m->sort_key);
+ if (r < 0)
+ return table_log_add_error(r);
+ }
+
+ return table_print_with_pager(t, arg_json_format_flags, arg_pager_flags, arg_legend);
+}
+
+static int mount_mstack(void) {
+ int r;
+
+ assert(arg_what);
+ assert(arg_where);
+
+ r = mstack_apply(
+ arg_what,
+ /* dir_fd= */ -EBADF,
+ arg_where,
+ /* temp_mount_dir= */ NULL, /* auto-create temporary directory */
+ /* userns_fd= */ -EBADF,
+ arg_image_policy,
+ arg_image_filter,
+ arg_mstack_flags,
+ /* ret_root_fd= */ NULL);
+ if (r < 0)
+ return log_error_errno(r, "Failed to apply .mstack/ directory '%s': %m", arg_what);
+
+ return 0;
+}
+
+static int umount_mstack(void) {
+ int r;
+
+ assert(arg_where);
+
+ _cleanup_free_ char *canonical = NULL;
+ _cleanup_close_ int fd = chase_and_open(arg_where, /* root= */ NULL, /* chase_flags= */ 0, O_DIRECTORY, &canonical);
+ if (fd == -ENOTDIR)
+ return log_error_errno(SYNTHETIC_ERRNO(ENOTDIR), "'%s' is not a directory", arg_where);
+ if (fd < 0)
+ return log_error_errno(fd, "Failed to resolve path '%s': %m", arg_where);
+
+ r = is_mount_point_at(fd, /* path= */ NULL, /* flags= */ 0);
+ if (r == 0)
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "'%s' is not a mount point", canonical);
+ if (r < 0)
+ return log_error_errno(r, "Failed to determine whether '%s' is a mount point: %m", canonical);
+
+ fd = safe_close(fd);
+
+ r = umount_recursive(canonical, 0);
+ if (r < 0)
+ return log_error_errno(r, "Failed to unmount '%s': %m", canonical);
+
+ if (arg_rmdir) {
+ r = RET_NERRNO(rmdir(canonical));
+ if (r < 0)
+ return log_error_errno(r, "Failed to remove mount directory '%s': %m", canonical);
+ }
+
+ return 0;
+}
+
+static int run(int argc, char *argv[]) {
+ int r;
+
+ log_setup();
+
+ if (invoked_as(argv, "mount.mstack"))
+ r = parse_argv_as_mount_helper(argc, argv);
+ else
+ r = parse_argv(argc, argv);
+ if (r <= 0)
+ return r;
+
+ switch (arg_action) {
+
+ case ACTION_INSPECT:
+ return inspect_mstack();
+
+ case ACTION_MOUNT:
+ return mount_mstack();
+
+ case ACTION_UMOUNT:
+ return umount_mstack();
+
+ default:
+ assert_not_reached();
+ }
+}
+
+DEFINE_MAIN_FUNCTION(run);
projects / thirdparty / systemd.git / commitdiff
