Merge pull request #18302 from bluca/mount_image_runtime

systemctl/core: add DBUS method to mount images without service restart

8 files changed, 149 insertions, 143 deletions

diff --git a/src/core/dbus-execute.c b/src/core/dbus-execute.c
index 20403df819..8434ccb48e 100644
--- a/src/core/dbus-execute.c
+++ b/src/core/dbus-execute.c
@@ -1497,74 +1497,6 @@ static BUS_DEFINE_SET_TRANSIENT_TO_STRING_ALLOC(capability, "t", uint64_t, uint6
 static BUS_DEFINE_SET_TRANSIENT_TO_STRING_ALLOC(namespace_flag, "t", uint64_t, unsigned long, "%" PRIu64, namespace_flags_to_string);
 static BUS_DEFINE_SET_TRANSIENT_TO_STRING(mount_flags, "t", uint64_t, unsigned long, "%" PRIu64, mount_propagation_flags_to_string_with_check);
 
-/* ret_format_str is an accumulator, so if it has any pre-existing content, new options will be appended to it */
-static int read_mount_options(sd_bus_message *message, sd_bus_error *error, MountOptions **ret_options, char **ret_format_str, const char *separator) {
-        _cleanup_(mount_options_free_allp) MountOptions *options = NULL;
-        _cleanup_free_ char *format_str = NULL;
-        const char *mount_options, *partition;
-        int r;
-
-        assert(message);
-        assert(ret_options);
-        assert(ret_format_str);
-        assert(separator);
-
-        r = sd_bus_message_enter_container(message, 'a', "(ss)");
-        if (r < 0)
-                return r;
-
-        while ((r = sd_bus_message_read(message, "(ss)", &partition, &mount_options)) > 0) {
-                _cleanup_free_ char *previous = NULL, *escaped = NULL;
-                _cleanup_free_ MountOptions *o = NULL;
-                PartitionDesignator partition_designator;
-
-                if (chars_intersect(mount_options, WHITESPACE))
-                        return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS,
-                                                "Invalid mount options string, contains whitespace character(s): %s", mount_options);
-
-                partition_designator = partition_designator_from_string(partition);
-                if (partition_designator < 0)
-                        return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid partition name %s", partition);
-
-                /* Need to store them in the unit with the escapes, so that they can be parsed again */
-                escaped = shell_escape(mount_options, ":");
-                if (!escaped)
-                        return -ENOMEM;
-
-                previous = TAKE_PTR(format_str);
-                format_str = strjoin(previous, previous ? separator : "", partition, ":", escaped);
-                if (!format_str)
-                        return -ENOMEM;
-
-                o = new(MountOptions, 1);
-                if (!o)
-                        return -ENOMEM;
-                *o = (MountOptions) {
-                        .partition_designator = partition_designator,
-                        .options = strdup(mount_options),
-                };
-                if (!o->options)
-                        return -ENOMEM;
-                LIST_APPEND(mount_options, options, TAKE_PTR(o));
-        }
-        if (r < 0)
-                return r;
-
-        r = sd_bus_message_exit_container(message);
-        if (r < 0)
-                return r;
-
-        if (!LIST_IS_EMPTY(options)) {
-                char *final = strjoin(*ret_format_str, !isempty(*ret_format_str) ? separator : "", format_str);
-                if (!final)
-                        return -ENOMEM;
-                free_and_replace(*ret_format_str, final);
-                LIST_JOIN(mount_options, *ret_options, options);
-        }
-
-        return 0;
-}
-
 int bus_exec_context_set_transient_property(
                 Unit *u,
                 ExecContext *c,
@@ -1599,7 +1531,7 @@ int bus_exec_context_set_transient_property(
                 _cleanup_(mount_options_free_allp) MountOptions *options = NULL;
                 _cleanup_free_ char *format_str = NULL;
 
-                r = read_mount_options(message, error, &options, &format_str, " ");
+                r = bus_read_mount_options(message, error, &options, &format_str, " ");
                 if (r < 0)
                         return r;
 
@@ -3407,7 +3339,7 @@ int bus_exec_context_set_transient_property(
                                 return -ENOMEM;
                         free_and_replace(format_str, tuple);
 
-                        r = read_mount_options(message, error, &options, &format_str, ":");
+                        r = bus_read_mount_options(message, error, &options, &format_str, ":");
                         if (r < 0)
                                 return r;
 
diff --git a/src/core/dbus-manager.c b/src/core/dbus-manager.c
index 4b88f0d9f0..eeb74353da 100644
--- a/src/core/dbus-manager.c
+++ b/src/core/dbus-manager.c
@@ -731,6 +731,11 @@ static int method_bind_mount_unit(sd_bus_message *message, void *userdata, sd_bu
         return method_generic_unit_operation(message, userdata, error, bus_service_method_bind_mount, GENERIC_UNIT_VALIDATE_LOADED);
 }
 
+static int method_mount_image_unit(sd_bus_message *message, void *userdata, sd_bus_error *error) {
+        /* Only add mounts on fully loaded units */
+        return method_generic_unit_operation(message, userdata, error, bus_service_method_mount_image, GENERIC_UNIT_VALIDATE_LOADED);
+}
+
 static int method_ref_unit(sd_bus_message *message, void *userdata, sd_bus_error *error) {
         /* Only allow reffing of fully loaded units, and make sure reffing a unit loads it. */
         return method_generic_unit_operation(message, userdata, error, bus_unit_method_ref, GENERIC_UNIT_LOAD|GENERIC_UNIT_VALIDATE_LOADED);
@@ -2776,6 +2781,17 @@ const sd_bus_vtable bus_manager_vtable[] = {
                                  NULL,,
                                  method_bind_mount_unit,
                                  SD_BUS_VTABLE_UNPRIVILEGED),
+        SD_BUS_METHOD_WITH_NAMES("MountImageUnit",
+                                 "sssbba(ss)",
+                                 SD_BUS_PARAM(name)
+                                 SD_BUS_PARAM(source)
+                                 SD_BUS_PARAM(destination)
+                                 SD_BUS_PARAM(read_only)
+                                 SD_BUS_PARAM(mkdir)
+                                 SD_BUS_PARAM(options),
+                                 NULL,,
+                                 method_mount_image_unit,
+                                 SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD_WITH_NAMES("RefUnit",
                                  "s",
                                  SD_BUS_PARAM(name),
diff --git a/src/core/dbus-service.c b/src/core/dbus-service.c
index 6df93e44a4..f7cdb51eba 100644
--- a/src/core/dbus-service.c
+++ b/src/core/dbus-service.c
@@ -95,9 +95,10 @@ static int property_get_exit_status_set(
         return sd_bus_message_close_container(reply);
 }
 
-int bus_service_method_bind_mount(sd_bus_message *message, void *userdata, sd_bus_error *error) {
-        int read_only, make_file_or_directory;
+static int bus_service_method_mount(sd_bus_message *message, void *userdata, sd_bus_error *error, bool is_image) {
+        _cleanup_(mount_options_free_allp) MountOptions *options = NULL;
         const char *dest, *src, *propagate_directory;
+        int read_only, make_file_or_directory;
         Unit *u = userdata;
         ExecContext *c;
         pid_t unit_pid;
@@ -120,16 +121,22 @@ int bus_service_method_bind_mount(sd_bus_message *message, void *userdata, sd_bu
         if (!path_is_absolute(src) || !path_is_normalized(src))
                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Source path must be absolute and normalized.");
 
-        if (isempty(dest))
+        if (!is_image && isempty(dest))
                 dest = src;
         else if (!path_is_absolute(dest) || !path_is_normalized(dest))
                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Destination path must be absolute and normalized.");
 
+        if (is_image) {
+                r = bus_read_mount_options(message, error, &options, NULL, "");
+                if (r < 0)
+                        return r;
+        }
+
         r = bus_verify_manage_units_async_full(
                         u,
-                        "bind-mount",
+                        is_image ? "mount-image" : "bind-mount",
                         CAP_SYS_ADMIN,
-                        N_("Authentication is required to bind mount on '$(unit)'."),
+                        N_("Authentication is required to mount on '$(unit)'."),
                         true,
                         message,
                         error);
@@ -158,16 +165,30 @@ int bus_service_method_bind_mount(sd_bus_message *message, void *userdata, sd_bu
                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Unit is not running");
 
         propagate_directory = strjoina("/run/systemd/propagate/", u->id);
-        r = bind_mount_in_namespace(unit_pid,
-                                    propagate_directory,
-                                    "/run/systemd/incoming/",
-                                    src, dest, read_only, make_file_or_directory);
+        if (is_image)
+                r = mount_image_in_namespace(unit_pid,
+                                             propagate_directory,
+                                             "/run/systemd/incoming/",
+                                             src, dest, read_only, make_file_or_directory, options);
+        else
+                r = bind_mount_in_namespace(unit_pid,
+                                            propagate_directory,
+                                            "/run/systemd/incoming/",
+                                            src, dest, read_only, make_file_or_directory);
         if (r < 0)
                 return sd_bus_error_set_errnof(error, r, "Failed to mount %s on %s in unit's namespace: %m", src, dest);
 
         return sd_bus_reply_method_return(message, NULL);
 }
 
+int bus_service_method_bind_mount(sd_bus_message *message, void *userdata, sd_bus_error *error) {
+        return bus_service_method_mount(message, userdata, error, false);
+}
+
+int bus_service_method_mount_image(sd_bus_message *message, void *userdata, sd_bus_error *error) {
+        return bus_service_method_mount(message, userdata, error, true);
+}
+
 const sd_bus_vtable bus_service_vtable[] = {
         SD_BUS_VTABLE_START(0),
         SD_BUS_PROPERTY("Type", "s", property_get_type, offsetof(Service, type), SD_BUS_VTABLE_PROPERTY_CONST),
@@ -233,6 +254,17 @@ const sd_bus_vtable bus_service_vtable[] = {
                                  bus_service_method_bind_mount,
                                  SD_BUS_VTABLE_UNPRIVILEGED),
 
+        SD_BUS_METHOD_WITH_NAMES("MountImage",
+                                 "ssbba(ss)",
+                                 SD_BUS_PARAM(source)
+                                 SD_BUS_PARAM(destination)
+                                 SD_BUS_PARAM(read_only)
+                                 SD_BUS_PARAM(mkdir)
+                                 SD_BUS_PARAM(options),
+                                 NULL,,
+                                 bus_service_method_mount_image,
+                                 SD_BUS_VTABLE_UNPRIVILEGED),
+
         /* The following four are obsolete, and thus marked hidden here. They moved into the Unit interface */
         SD_BUS_PROPERTY("StartLimitInterval", "t", bus_property_get_usec, offsetof(Unit, start_ratelimit.interval), SD_BUS_VTABLE_PROPERTY_CONST|SD_BUS_VTABLE_HIDDEN),
         SD_BUS_PROPERTY("StartLimitBurst", "u", bus_property_get_unsigned, offsetof(Unit, start_ratelimit.burst), SD_BUS_VTABLE_PROPERTY_CONST|SD_BUS_VTABLE_HIDDEN),
diff --git a/src/core/dbus-service.h b/src/core/dbus-service.h
index 5b7b7b757b..9a05465802 100644
--- a/src/core/dbus-service.h
+++ b/src/core/dbus-service.h
@@ -10,4 +10,5 @@ extern const sd_bus_vtable bus_service_vtable[];
 
 int bus_service_set_property(Unit *u, const char *name, sd_bus_message *i, UnitWriteFlags flags, sd_bus_error *error);
 int bus_service_method_bind_mount(sd_bus_message *message, void *userdata, sd_bus_error *error);
+int bus_service_method_mount_image(sd_bus_message *message, void *userdata, sd_bus_error *error);
 int bus_service_commit_properties(Unit *u);
diff --git a/src/core/dbus-util.c b/src/core/dbus-util.c
index 2d22bc699a..6a6dd1ff41 100644
--- a/src/core/dbus-util.c
+++ b/src/core/dbus-util.c
@@ -3,6 +3,7 @@
 #include "bus-polkit.h"
 #include "bus-util.h"
 #include "dbus-util.h"
+#include "escape.h"
 #include "parse-util.h"
 #include "path-util.h"
 #include "unit-printf.h"
@@ -186,3 +187,78 @@ int bus_verify_manage_units_async_full(
                         &u->manager->polkit_registry,
                         error);
 }
+
+/* ret_format_str is an accumulator, so if it has any pre-existing content, new options will be appended to it */
+int bus_read_mount_options(
+                sd_bus_message *message,
+                sd_bus_error *error,
+                MountOptions **ret_options,
+                char **ret_format_str,
+                const char *separator) {
+
+        _cleanup_(mount_options_free_allp) MountOptions *options = NULL;
+        _cleanup_free_ char *format_str = NULL;
+        const char *mount_options, *partition;
+        int r;
+
+        assert(message);
+        assert(ret_options);
+        assert(separator);
+
+        r = sd_bus_message_enter_container(message, 'a', "(ss)");
+        if (r < 0)
+                return r;
+
+        while ((r = sd_bus_message_read(message, "(ss)", &partition, &mount_options)) > 0) {
+                _cleanup_free_ char *previous = NULL, *escaped = NULL;
+                _cleanup_free_ MountOptions *o = NULL;
+                PartitionDesignator partition_designator;
+
+                if (chars_intersect(mount_options, WHITESPACE))
+                        return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS,
+                                                "Invalid mount options string, contains whitespace character(s): %s", mount_options);
+
+                partition_designator = partition_designator_from_string(partition);
+                if (partition_designator < 0)
+                        return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid partition name %s", partition);
+
+                /* Need to store the options with the escapes, so that they can be parsed again */
+                escaped = shell_escape(mount_options, ":");
+                if (!escaped)
+                        return -ENOMEM;
+
+                previous = TAKE_PTR(format_str);
+                format_str = strjoin(previous, previous ? separator : "", partition, ":", escaped);
+                if (!format_str)
+                        return -ENOMEM;
+
+                o = new(MountOptions, 1);
+                if (!o)
+                        return -ENOMEM;
+                *o = (MountOptions) {
+                        .partition_designator = partition_designator,
+                        .options = strdup(mount_options),
+                };
+                if (!o->options)
+                        return -ENOMEM;
+                LIST_APPEND(mount_options, options, TAKE_PTR(o));
+        }
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_exit_container(message);
+        if (r < 0)
+                return r;
+
+        if (!LIST_IS_EMPTY(options)) {
+                if (ret_format_str) {
+                        char *final = strjoin(*ret_format_str, !isempty(*ret_format_str) ? separator : "", format_str);
+                        if (!final)
+                                return -ENOMEM;
+                        free_and_replace(*ret_format_str, final);
+                }
+                LIST_JOIN(mount_options, *ret_options, options);
+        }
+
+        return 0;
+}
diff --git a/src/core/dbus-util.h b/src/core/dbus-util.h
index e35c632d37..bd4fd081c5 100644
--- a/src/core/dbus-util.h
+++ b/src/core/dbus-util.h
@@ -3,6 +3,7 @@
 
 #include "sd-bus.h"
 
+#include "dissect-image.h"
 #include "unit.h"
 
 int bus_property_get_triggered_unit(sd_bus *bus, const char *path, const char *interface, const char *property, sd_bus_message *reply, void *userdata, sd_bus_error *error);
@@ -249,3 +250,5 @@ static inline int bus_set_transient_usec_fix_0(Unit *u, const char *name, usec_t
         return bus_set_transient_usec_internal(u, name, p, true, message, flags, error);
 }
 int bus_verify_manage_units_async_full(Unit *u, const char *verb, int capability, const char *polkit_message, bool interactive, sd_bus_message *call, sd_bus_error *error);
+
+int bus_read_mount_options(sd_bus_message *message, sd_bus_error *error, MountOptions **ret_options, char **ret_format_str, const char *separator);
diff --git a/src/core/namespace.c b/src/core/namespace.c
index 12d9e4c867..db9a12319d 100644
--- a/src/core/namespace.c
+++ b/src/core/namespace.c
@@ -962,75 +962,13 @@ static int mount_run(const MountEntry *m) {
 }
 
 static int mount_images(const MountEntry *m) {
-        _cleanup_(loop_device_unrefp) LoopDevice *loop_device = NULL;
-        _cleanup_(decrypted_image_unrefp) DecryptedImage *decrypted_image = NULL;
-        _cleanup_(dissected_image_unrefp) DissectedImage *dissected_image = NULL;
-        _cleanup_(verity_settings_done) VeritySettings verity = VERITY_SETTINGS_DEFAULT;
-        DissectImageFlags dissect_image_flags;
         int r;
 
         assert(m);
 
-        r = verity_settings_load(&verity, mount_entry_source(m), NULL, NULL);
-        if (r < 0)
-                return log_debug_errno(r, "Failed to load root hash: %m");
-
-        dissect_image_flags =
-                (m->read_only ? DISSECT_IMAGE_READ_ONLY : 0) |
-                (verity.data_path ? DISSECT_IMAGE_NO_PARTITION_TABLE : 0);
-
-        r = loop_device_make_by_path(
-                        mount_entry_source(m),
-                        m->read_only ? O_RDONLY : -1 /* < 0 means writable if possible, read-only as fallback */,
-                        verity.data_path ? 0 : LO_FLAGS_PARTSCAN,
-                        &loop_device);
-        if (r < 0)
-                return log_debug_errno(r, "Failed to create loop device for image: %m");
-
-        r = dissect_image(
-                        loop_device->fd,
-                        &verity,
-                        m->image_options,
-                        dissect_image_flags,
-                        &dissected_image);
-        /* No partition table? Might be a single-filesystem image, try again */
-        if (!verity.data_path && r == -ENOPKG)
-                 r = dissect_image(
-                                 loop_device->fd,
-                                 &verity,
-                                 m->image_options,
-                                 dissect_image_flags|DISSECT_IMAGE_NO_PARTITION_TABLE,
-                                 &dissected_image);
-        if (r < 0)
-                return log_debug_errno(r, "Failed to dissect image: %m");
-
-        r = dissected_image_decrypt(
-                        dissected_image,
-                        NULL,
-                        &verity,
-                        dissect_image_flags,
-                        &decrypted_image);
-        if (r < 0)
-                return log_debug_errno(r, "Failed to decrypt dissected image: %m");
-
-        r = mkdir_p_label(mount_entry_path(m), 0755);
-        if (r < 0)
-                return log_debug_errno(r, "Failed to create destination directory %s: %m", mount_entry_path(m));
-        r = umount_recursive(mount_entry_path(m), 0);
-        if (r < 0)
-                return log_debug_errno(r, "Failed to umount under destination directory %s: %m", mount_entry_path(m));
-
-        r = dissected_image_mount(dissected_image, mount_entry_path(m), UID_INVALID, dissect_image_flags);
+        r = verity_dissect_and_mount(mount_entry_source(m), mount_entry_path(m), m->image_options);
         if (r < 0)
-                return log_debug_errno(r, "Failed to mount image: %m");
-
-        if (decrypted_image) {
-                r = decrypted_image_relinquish(decrypted_image);
-                if (r < 0)
-                        return log_debug_errno(r, "Failed to relinquish decrypted image: %m");
-        }
-
-        loop_device_relinquish(loop_device);
+                return log_debug_errno(r, "Failed to mount image %s on %s: %m", mount_entry_source(m), mount_entry_path(m));
 
         return 1;
 }
diff --git a/src/core/org.freedesktop.systemd1.conf b/src/core/org.freedesktop.systemd1.conf
index 0cea4d2b02..f405b27658 100644
--- a/src/core/org.freedesktop.systemd1.conf
+++ b/src/core/org.freedesktop.systemd1.conf
@@ -228,6 +228,10 @@
 
                 <allow send_destination="org.freedesktop.systemd1"
                        send_interface="org.freedesktop.systemd1.Manager"
+                       send_member="MountImageUnit"/>
+
+                <allow send_destination="org.freedesktop.systemd1"
+                       send_interface="org.freedesktop.systemd1.Manager"
                        send_member="KillUnit"/>
 
                 <allow send_destination="org.freedesktop.systemd1"
@@ -400,6 +404,10 @@
                        send_interface="org.freedesktop.systemd1.Service"
                        send_member="BindMount"/>
 
+                <allow send_destination="org.freedesktop.systemd1"
+                       send_interface="org.freedesktop.systemd1.Service"
+                       send_member="MountImage"/>
+
                 <!-- Managed via polkit or other criteria: org.freedesktop.systemd1.Scope interface -->
 
                 <allow send_destination="org.freedesktop.systemd1"