tmpfiles: support --image= similar to --root=

[thirdparty/systemd.git] / src / tmpfiles / tmpfiles.c

diff --git a/src/tmpfiles/tmpfiles.c b/src/tmpfiles/tmpfiles.c
index 2404e36bf2984873eeb709721115d7ad91a560bc..616a54b3c31c20f392d4a8e19bdcc40a6f89cea8 100644 (file)
--- a/src/tmpfiles/tmpfiles.c
+++ b/src/tmpfiles/tmpfiles.c
@@ -26,6 +26,7 @@
 #include "copy.h"
 #include "def.h"
 #include "dirent-util.h"
+#include "dissect-image.h"
 #include "escape.h"
 #include "fd-util.h"
 #include "fileio.h"
@@ -38,6 +39,7 @@
 #include "macro.h"
 #include "main-func.h"
 #include "mkdir.h"
+#include "mount-util.h"
 #include "mountpoint-util.h"
 #include "offline-passwd.h"
 #include "pager.h"
@@ -164,6 +166,7 @@ static PagerFlags arg_pager_flags = 0;
 static char **arg_include_prefixes = NULL;
 static char **arg_exclude_prefixes = NULL;
 static char *arg_root = NULL;
+static char *arg_image = NULL;
 static char *arg_replace = NULL;
 
 #define MAX_DEPTH 256
@@ -177,6 +180,7 @@ STATIC_DESTRUCTOR_REGISTER(unix_sockets, set_free_freep);
 STATIC_DESTRUCTOR_REGISTER(arg_include_prefixes, freep);
 STATIC_DESTRUCTOR_REGISTER(arg_exclude_prefixes, freep);
 STATIC_DESTRUCTOR_REGISTER(arg_root, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_image, freep);
 
 static int specifier_machine_id_safe(char specifier, const void *data, const void *userdata, char **ret);
 static int specifier_directory(char specifier, const void *data, const void *userdata, char **ret);
@@ -2884,6 +2888,27 @@ static int cat_config(char **config_dirs, char **args) {
         return cat_files(NULL, files, 0);
 }
 
+static int exclude_default_prefixes(void) {
+        int r;
+
+        /* Provide an easy way to exclude virtual/memory file systems from what we do here. Useful in
+         * combination with --root= where we probably don't want to apply stuff to these dirs as they are
+         * likely over-mounted if the root directory is actually used, and it wouldbe less than ideal to have
+         * all kinds of files created/adjusted underneath these mount points. */
+
+        r = strv_extend_strv(
+                        &arg_exclude_prefixes,
+                        STRV_MAKE("/dev",
+                                  "/proc",
+                                  "/run",
+                                  "/sys"),
+                                 true);
+        if (r < 0)
+                return log_oom();
+
+        return 0;
+}
+
 static int help(void) {
         _cleanup_free_ char *link = NULL;
         int r;
@@ -2904,7 +2929,9 @@ static int help(void) {
                "     --boot                 Execute actions only safe at boot\n"
                "     --prefix=PATH          Only apply rules with the specified prefix\n"
                "     --exclude-prefix=PATH  Ignore rules with the specified prefix\n"
+               "  -E                        Ignore rules prefixed with /dev, /proc, /run, /sys\n"
                "     --root=PATH            Operate on an alternate filesystem root\n"
+               "     --image=PATH           Operate on disk image as filesystem root\n"
                "     --replace=PATH         Treat arguments as replacement for PATH\n"
                "     --no-pager             Do not pipe output into a pager\n"
                "\nSee the %s for details.\n"
@@ -2928,6 +2955,7 @@ static int parse_argv(int argc, char *argv[]) {
                 ARG_PREFIX,
                 ARG_EXCLUDE_PREFIX,
                 ARG_ROOT,
+                ARG_IMAGE,
                 ARG_REPLACE,
                 ARG_NO_PAGER,
         };
@@ -2944,6 +2972,7 @@ static int parse_argv(int argc, char *argv[]) {
                 { "prefix",         required_argument,   NULL, ARG_PREFIX         },
                 { "exclude-prefix", required_argument,   NULL, ARG_EXCLUDE_PREFIX },
                 { "root",           required_argument,   NULL, ARG_ROOT           },
+                { "image",          required_argument,   NULL, ARG_IMAGE          },
                 { "replace",        required_argument,   NULL, ARG_REPLACE        },
                 { "no-pager",       no_argument,         NULL, ARG_NO_PAGER       },
                 {}
@@ -2954,7 +2983,7 @@ static int parse_argv(int argc, char *argv[]) {
         assert(argc >= 0);
         assert(argv);
 
-        while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0)
+        while ((c = getopt_long(argc, argv, "hE", options, NULL)) >= 0)
 
                 switch (c) {
 
@@ -3004,6 +3033,21 @@ static int parse_argv(int argc, char *argv[]) {
                                 return r;
                         break;
 
+                case ARG_IMAGE:
+                        r = parse_path_argument_and_warn(optarg, /* suppress_root= */ false, &arg_image);
+                        if (r < 0)
+                                return r;
+
+                        /* Imply -E here since it makes little sense to create files persistently in the /run mointpoint of a disk image */
+                        _fallthrough_;
+
+                case 'E':
+                        r = exclude_default_prefixes();
+                        if (r < 0)
+                                return r;
+
+                        break;
+
                 case ARG_REPLACE:
                         if (!path_is_absolute(optarg) ||
                             !endswith(optarg, ".conf"))
@@ -3036,6 +3080,13 @@ static int parse_argv(int argc, char *argv[]) {
                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                        "When --replace= is given, some configuration items must be specified");
 
+        if (arg_root && arg_user)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "Combination of --user and --root= is not supported.");
+
+        if (arg_image && arg_root)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Please specify either --root= or --image=, the combination of both is not supported.");
+
         return 1;
 }
 
@@ -3211,6 +3262,9 @@ DEFINE_PRIVATE_HASH_OPS_WITH_VALUE_DESTRUCTOR(item_array_hash_ops, char, string_
                                               ItemArray, item_array_free);
 
 static int run(int argc, char *argv[]) {
+        _cleanup_(loop_device_unrefp) LoopDevice *loop_device = NULL;
+        _cleanup_(decrypted_image_unrefp) DecryptedImage *decrypted_image = NULL;
+        _cleanup_(umount_and_rmdir_and_freep) char *unlink_dir = NULL;
         _cleanup_strv_free_ char **config_dirs = NULL;
         bool invalid_config = false;
         Iterator iterator;
@@ -3243,10 +3297,20 @@ static int run(int argc, char *argv[]) {
 
         if (DEBUG_LOGGING) {
                 _cleanup_free_ char *t = NULL;
+                char **i;
+
+                STRV_FOREACH(i, config_dirs) {
+                        _cleanup_free_ char *j = NULL;
+
+                        j = path_join(arg_root, *i);
+                        if (!j)
+                                return log_oom();
+
+                        if (!strextend(&t, "\n\t", j, NULL))
+                                return log_oom();
+                }
 
-                t = strv_join(config_dirs, "\n\t");
-                if (t)
-                        log_debug("Looking for configuration files in (higher priority first):\n\t%s", t);
+                log_debug("Looking for configuration files in (higher priority first):%s", t);
         }
 
         if (arg_cat_config) {
@@ -3261,6 +3325,23 @@ static int run(int argc, char *argv[]) {
         if (r < 0)
                 return r;
 
+        if (arg_image) {
+                assert(!arg_root);
+
+                r = mount_image_privately_interactively(
+                                arg_image,
+                                DISSECT_IMAGE_REQUIRE_ROOT|DISSECT_IMAGE_VALIDATE_OS|DISSECT_IMAGE_RELAX_VAR_CHECK|DISSECT_IMAGE_FSCK,
+                                &unlink_dir,
+                                &loop_device,
+                                &decrypted_image);
+                if (r < 0)
+                        return r;
+
+                arg_root = strdup(unlink_dir);
+                if (!arg_root)
+                        return log_oom();
+        }
+
         items = ordered_hashmap_new(&item_array_hash_ops);
         globs = ordered_hashmap_new(&item_array_hash_ops);
         if (!items || !globs)