add new portable service framework

This adds a small service "systemd-portabled" and a matching client
"portablectl", which implement the "portable service" concept.

The daemon implements the actual operations, is PolicyKit-enabled and is
activated on demand with exit-on-idle.

Both the daemon and the client are an optional build artifact, enabled
by default rhough.

1 files changed, 733 insertions, 0 deletions

diff --git a/src/portable/portabled-image-bus.c b/src/portable/portabled-image-bus.c
new file mode 100644
index 0000000000..7a13ea235a
--- /dev/null
+++ b/src/portable/portabled-image-bus.c
@@ -0,0 +1,733 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include "alloc-util.h"
+#include "bus-common-errors.h"
+#include "bus-label.h"
+#include "bus-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "io-util.h"
+#include "machine-image.h"
+#include "portable.h"
+#include "portabled-bus.h"
+#include "portabled-image-bus.h"
+#include "portabled-image.h"
+#include "portabled.h"
+#include "process-util.h"
+#include "strv.h"
+#include "user-util.h"
+
+static BUS_DEFINE_PROPERTY_GET_ENUM(property_get_type, image_type, ImageType);
+
+int bus_image_common_get_os_release(
+                Manager *m,
+                sd_bus_message *message,
+                const char *name_or_path,
+                Image *image,
+                sd_bus_error *error) {
+
+        int r;
+
+        assert(name_or_path || image);
+        assert(message);
+
+        if (!m) {
+                assert(image);
+                m = image->userdata;
+        }
+
+        r = bus_image_acquire(m,
+                              message,
+                              name_or_path,
+                              image,
+                              BUS_IMAGE_AUTHENTICATE_BY_PATH,
+                              "org.freedesktop.portable1.inspect-images",
+                              &image,
+                              error);
+        if (r < 0)
+                return r;
+        if (r == 0) /* Will call us back */
+                return 1;
+
+        if (!image->metadata_valid) {
+                r = image_read_metadata(image);
+                if (r < 0)
+                        return sd_bus_error_set_errnof(error, r, "Failed to read image metadata: %m");
+        }
+
+        return bus_reply_pair_array(message, image->os_release);
+}
+
+static int bus_image_method_get_os_release(sd_bus_message *message, void *userdata, sd_bus_error *error) {
+        return bus_image_common_get_os_release(NULL, message, NULL, userdata, error);
+}
+
+static int append_fd(sd_bus_message *m, PortableMetadata *d) {
+        _cleanup_fclose_ FILE *f = NULL;
+        _cleanup_free_ char *buf = NULL;
+        size_t n;
+        int r;
+
+        assert(m);
+        assert(d);
+        assert(d->fd >= 0);
+
+        f = fdopen(d->fd, "re");
+        if (!f)
+                return -errno;
+
+        d->fd = -1;
+
+        r = read_full_stream(f, &buf, &n);
+        if (r < 0)
+                return r;
+
+        return sd_bus_message_append_array(m, 'y', buf, n);
+}
+
+int bus_image_common_get_metadata(
+                Manager *m,
+                sd_bus_message *message,
+                const char *name_or_path,
+                Image *image,
+                sd_bus_error *error) {
+
+        _cleanup_(portable_metadata_unrefp) PortableMetadata *os_release = NULL;
+        _cleanup_(portable_metadata_hashmap_unrefp) Hashmap *unit_files = NULL;
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
+        _cleanup_free_ PortableMetadata **sorted = NULL;
+        _cleanup_strv_free_ char **matches = NULL;
+        size_t i;
+        int r;
+
+        assert(name_or_path || image);
+        assert(message);
+
+        if (!m) {
+                assert(image);
+                m = image->userdata;
+        }
+
+        r = sd_bus_message_read_strv(message, &matches);
+        if (r < 0)
+                return r;
+
+        r = bus_image_acquire(m,
+                              message,
+                              name_or_path,
+                              image,
+                              BUS_IMAGE_AUTHENTICATE_BY_PATH,
+                              "org.freedesktop.portable1.inspect-images",
+                              &image,
+                              error);
+        if (r < 0)
+                return r;
+        if (r == 0) /* Will call us back */
+                return 1;
+
+        r = portable_extract(
+                        image->path,
+                        matches,
+                        &os_release,
+                        &unit_files,
+                        error);
+        if (r < 0)
+                return r;
+
+        r = portable_metadata_hashmap_to_sorted_array(unit_files, &sorted);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_new_method_return(message, &reply);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_append(reply, "s", image->path);
+        if (r < 0)
+                return r;
+
+        r = append_fd(reply, os_release);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_open_container(reply, 'a', "{say}");
+        if (r < 0)
+                return r;
+
+        for (i = 0; i < hashmap_size(unit_files); i++) {
+
+
+                r = sd_bus_message_open_container(reply, 'e', "say");
+                if (r < 0)
+                        return r;
+
+                r = sd_bus_message_append(reply, "s", sorted[i]->name);
+                if (r < 0)
+                        return r;
+
+                r = append_fd(reply, sorted[i]);
+                if (r < 0)
+                        return r;
+
+                r = sd_bus_message_close_container(reply);
+                if (r < 0)
+                        return r;
+        }
+
+        r = sd_bus_message_close_container(reply);
+        if (r < 0)
+                return r;
+
+        return sd_bus_send(NULL, reply, NULL);
+}
+
+static int bus_image_method_get_metadata(sd_bus_message *message, void *userdata, sd_bus_error *error) {
+        return bus_image_common_get_metadata(NULL, message, NULL, userdata, error);
+}
+
+static int bus_image_method_get_state(
+                sd_bus_message *message,
+                void *userdata,
+                sd_bus_error *error) {
+
+        Image *image = userdata;
+        PortableState state;
+        int r;
+
+        assert(message);
+        assert(image);
+
+        r = portable_get_state(
+                        sd_bus_message_get_bus(message),
+                        image->path,
+                        0,
+                        &state,
+                        error);
+        if (r < 0)
+                return r;
+
+        return sd_bus_reply_method_return(message, "s", portable_state_to_string(state));
+}
+
+int bus_image_common_attach(
+                Manager *m,
+                sd_bus_message *message,
+                const char *name_or_path,
+                Image *image,
+                sd_bus_error *error) {
+
+        _cleanup_free_ char **matches = NULL;
+        PortableChange *changes = NULL;
+        PortableFlags flags = 0;
+        const char *copy_mode;
+        size_t n_changes = 0;
+        const char *profile;
+        int runtime, r;
+
+        assert(message);
+        assert(name_or_path || image);
+
+        if (!m) {
+                assert(image);
+                m = image->userdata;
+        }
+
+        r = sd_bus_message_read_strv(message, &matches);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_read(message, "sbs", &profile, &runtime, &copy_mode);
+        if (r < 0)
+                return r;
+
+        if (streq(copy_mode, "symlink"))
+                flags |= PORTABLE_PREFER_SYMLINK;
+        else if (streq(copy_mode, "copy"))
+                flags |= PORTABLE_PREFER_COPY;
+        else if (!isempty(copy_mode))
+                return sd_bus_reply_method_errorf(message, SD_BUS_ERROR_INVALID_ARGS, "Unknown copy mode '%s'", copy_mode);
+
+        if (runtime)
+                flags |= PORTABLE_RUNTIME;
+
+        r = bus_image_acquire(m,
+                              message,
+                              name_or_path,
+                              image,
+                              BUS_IMAGE_AUTHENTICATE_ALL,
+                              "org.freedesktop.portable1.attach-images",
+                              &image,
+                              error);
+        if (r < 0)
+                return r;
+        if (r == 0) /* Will call us back */
+                return 1;
+
+        r = portable_attach(
+                        sd_bus_message_get_bus(message),
+                        image->path,
+                        matches,
+                        profile,
+                        flags,
+                        &changes,
+                        &n_changes,
+                        error);
+        if (r < 0)
+                goto finish;
+
+        r = reply_portable_changes(message, changes, n_changes);
+
+finish:
+        portable_changes_free(changes, n_changes);
+        return r;
+}
+
+static int bus_image_method_attach(sd_bus_message *message, void *userdata, sd_bus_error *error) {
+        return bus_image_common_attach(NULL, message, NULL, userdata, error);
+}
+
+static int bus_image_method_detach(
+                sd_bus_message *message,
+                void *userdata,
+                sd_bus_error *error) {
+
+        PortableChange *changes = NULL;
+        Image *image = userdata;
+        Manager *m = image->userdata;
+        size_t n_changes = 0;
+        int r, runtime;
+
+        assert(message);
+        assert(image);
+        assert(m);
+
+        r = sd_bus_message_read(message, "b", &runtime);
+        if (r < 0)
+                return r;
+
+        r = bus_verify_polkit_async(
+                        message,
+                        CAP_SYS_ADMIN,
+                        "org.freedesktop.portable1.attach-images",
+                        NULL,
+                        false,
+                        UID_INVALID,
+                        &m->polkit_registry,
+                        error);
+        if (r < 0)
+                return r;
+        if (r == 0)
+                return 1; /* Will call us back */
+
+        r = portable_detach(
+                        sd_bus_message_get_bus(message),
+                        image->path,
+                        runtime ? PORTABLE_RUNTIME : 0,
+                        &changes,
+                        &n_changes,
+                        error);
+        if (r < 0)
+                goto finish;
+
+        r = reply_portable_changes(message, changes, n_changes);
+
+finish:
+        portable_changes_free(changes, n_changes);
+        return r;
+}
+
+int bus_image_common_remove(
+                Manager *m,
+                sd_bus_message *message,
+                const char *name_or_path,
+                Image *image,
+                sd_bus_error *error) {
+
+        _cleanup_close_pair_ int errno_pipe_fd[2] = { -1, -1 };
+        _cleanup_(sigkill_waitp) pid_t child = 0;
+        PortableState state;
+        int r;
+
+        assert(message);
+        assert(name_or_path || image);
+
+        if (!m) {
+                assert(image);
+                m = image->userdata;
+        }
+
+        if (m->n_operations >= OPERATIONS_MAX)
+                return sd_bus_error_setf(error, SD_BUS_ERROR_LIMITS_EXCEEDED, "Too many ongoing operations.");
+
+        r = bus_image_acquire(m,
+                              message,
+                              name_or_path,
+                              image,
+                              BUS_IMAGE_AUTHENTICATE_ALL,
+                              "org.freedesktop.portable1.manage-images",
+                              &image,
+                              error);
+        if (r < 0)
+                return r;
+        if (r == 0)
+                return 1; /* Will call us back */
+
+        r = portable_get_state(
+                        sd_bus_message_get_bus(message),
+                        image->path,
+                        0,
+                        &state,
+                        error);
+        if (r < 0)
+                return r;
+
+        if (state != PORTABLE_DETACHED)
+                return sd_bus_error_set_errnof(error, EBUSY, "Image '%s' is not detached, refusing.", image->path);
+
+        if (pipe2(errno_pipe_fd, O_CLOEXEC|O_NONBLOCK) < 0)
+                return sd_bus_error_set_errnof(error, errno, "Failed to create pipe: %m");
+
+        r = safe_fork("(sd-imgrm)", FORK_RESET_SIGNALS, &child);
+        if (r < 0)
+                return sd_bus_error_set_errnof(error, r, "Failed to fork(): %m");
+        if (r == 0) {
+                errno_pipe_fd[0] = safe_close(errno_pipe_fd[0]);
+
+                r = image_remove(image);
+                if (r < 0) {
+                        (void) write(errno_pipe_fd[1], &r, sizeof(r));
+                        _exit(EXIT_FAILURE);
+                }
+
+                _exit(EXIT_SUCCESS);
+        }
+
+        errno_pipe_fd[1] = safe_close(errno_pipe_fd[1]);
+
+        r = operation_new(m, child, message, errno_pipe_fd[0], NULL);
+        if (r < 0)
+                return r;
+
+        child = 0;
+        errno_pipe_fd[0] = -1;
+
+        return 1;
+}
+
+static int bus_image_method_remove(sd_bus_message *message, void *userdata, sd_bus_error *error) {
+        return bus_image_common_remove(NULL, message, NULL, userdata, error);
+}
+
+int bus_image_common_mark_read_only(
+                Manager *m,
+                sd_bus_message *message,
+                const char *name_or_path,
+                Image *image,
+                sd_bus_error *error) {
+
+        int r, read_only;
+
+        assert(message);
+        assert(name_or_path || image);
+
+        if (!m) {
+                assert(image);
+                m = image->userdata;
+        }
+
+        r = sd_bus_message_read(message, "b", &read_only);
+        if (r < 0)
+                return r;
+
+        r = bus_image_acquire(m,
+                              message,
+                              name_or_path,
+                              image,
+                              BUS_IMAGE_AUTHENTICATE_ALL,
+                              "org.freedesktop.portable1.manage-images",
+                              &image,
+                              error);
+        if (r < 0)
+                return r;
+        if (r == 0)
+                return 1; /* Will call us back */
+
+        r = image_read_only(image, read_only);
+        if (r < 0)
+                return r;
+
+        return sd_bus_reply_method_return(message, NULL);
+}
+
+static int bus_image_method_mark_read_only(sd_bus_message *message, void *userdata, sd_bus_error *error) {
+        return bus_image_common_mark_read_only(NULL, message, NULL, userdata, error);
+}
+
+int bus_image_common_set_limit(
+                Manager *m,
+                sd_bus_message *message,
+                const char *name_or_path,
+                Image *image,
+                sd_bus_error *error) {
+
+        uint64_t limit;
+        int r;
+
+        assert(message);
+        assert(name_or_path || image);
+
+        if (!m) {
+                assert(image);
+                m = image->userdata;
+        }
+
+        r = sd_bus_message_read(message, "t", &limit);
+        if (r < 0)
+                return r;
+        if (!FILE_SIZE_VALID_OR_INFINITY(limit))
+                return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "New limit out of range");
+
+        r = bus_image_acquire(m,
+                              message,
+                              name_or_path,
+                              image,
+                              BUS_IMAGE_AUTHENTICATE_ALL,
+                              "org.freedesktop.portable1.manage-images",
+                              &image,
+                              error);
+        if (r < 0)
+                return r;
+        if (r == 0)
+                return 1; /* Will call us back */
+
+        r = image_set_limit(image, limit);
+        if (r < 0)
+                return r;
+
+        return sd_bus_reply_method_return(message, NULL);
+}
+
+static int bus_image_method_set_limit(sd_bus_message *message, void *userdata, sd_bus_error *error) {
+        return bus_image_common_set_limit(NULL, message, NULL, userdata, error);
+}
+
+const sd_bus_vtable image_vtable[] = {
+        SD_BUS_VTABLE_START(0),
+        SD_BUS_PROPERTY("Name", "s", NULL, offsetof(Image, name), 0),
+        SD_BUS_PROPERTY("Path", "s", NULL, offsetof(Image, path), 0),
+        SD_BUS_PROPERTY("Type", "s", property_get_type,  offsetof(Image, type), 0),
+        SD_BUS_PROPERTY("ReadOnly", "b", bus_property_get_bool, offsetof(Image, read_only), 0),
+        SD_BUS_PROPERTY("CreationTimestamp", "t", NULL, offsetof(Image, crtime), 0),
+        SD_BUS_PROPERTY("ModificationTimestamp", "t", NULL, offsetof(Image, mtime), 0),
+        SD_BUS_PROPERTY("Usage", "t", NULL, offsetof(Image, usage), 0),
+        SD_BUS_PROPERTY("Limit", "t", NULL, offsetof(Image, limit), 0),
+        SD_BUS_PROPERTY("UsageExclusive", "t", NULL, offsetof(Image, usage_exclusive), 0),
+        SD_BUS_PROPERTY("LimitExclusive", "t", NULL, offsetof(Image, limit_exclusive), 0),
+        SD_BUS_METHOD("GetOSRelease", NULL, "a{ss}", bus_image_method_get_os_release, SD_BUS_VTABLE_UNPRIVILEGED),
+        SD_BUS_METHOD("GetMedatadata", "as", "saya{say}", bus_image_method_get_metadata, SD_BUS_VTABLE_UNPRIVILEGED),
+        SD_BUS_METHOD("GetState", NULL, "s", bus_image_method_get_state, SD_BUS_VTABLE_UNPRIVILEGED),
+        SD_BUS_METHOD("Attach", "assbs", "a(sss)", bus_image_method_attach, SD_BUS_VTABLE_UNPRIVILEGED),
+        SD_BUS_METHOD("Detach", "b", "a(sss)", bus_image_method_detach, SD_BUS_VTABLE_UNPRIVILEGED),
+        SD_BUS_METHOD("Remove", NULL, NULL, bus_image_method_remove, SD_BUS_VTABLE_UNPRIVILEGED),
+        SD_BUS_METHOD("MarkReadOnly", "b", NULL, bus_image_method_mark_read_only, SD_BUS_VTABLE_UNPRIVILEGED),
+        SD_BUS_METHOD("SetLimit", "t", NULL, bus_image_method_set_limit, SD_BUS_VTABLE_UNPRIVILEGED),
+        SD_BUS_VTABLE_END
+};
+
+int bus_image_path(Image *image, char **ret) {
+        assert(image);
+        assert(ret);
+
+        if (!image->discoverable)
+                return -EINVAL;
+
+        return sd_bus_path_encode("/org/freedesktop/portable1/image", image->name, ret);
+}
+
+int bus_image_acquire(
+                Manager *m,
+                sd_bus_message *message,
+                const char *name_or_path,
+                Image *image,
+                ImageAcquireMode mode,
+                const char *polkit_action,
+                Image **ret,
+                sd_bus_error *error) {
+
+        _cleanup_(image_unrefp) Image *loaded = NULL;
+        Image *cached;
+        int r;
+
+        assert(m);
+        assert(message);
+        assert(name_or_path || image);
+        assert(mode >= 0);
+        assert(mode < _BUS_IMAGE_ACQUIRE_MODE_MAX);
+        assert(polkit_action || mode == BUS_IMAGE_REFUSE_BY_PATH);
+        assert(ret);
+
+        /* Acquires an 'Image' object if not acquired yet, and enforces necessary authentication while doing so. */
+
+        if (mode == BUS_IMAGE_AUTHENTICATE_ALL) {
+                r = bus_verify_polkit_async(
+                                message,
+                                CAP_SYS_ADMIN,
+                                polkit_action,
+                                NULL,
+                                false,
+                                UID_INVALID,
+                                &m->polkit_registry,
+                                error);
+                if (r < 0)
+                        return r;
+                if (r == 0) { /* Will call us back */
+                        *ret = NULL;
+                        return 0;
+                }
+        }
+
+        /* Already passed in? */
+        if (image) {
+                *ret = image;
+                return 1;
+        }
+
+        /* Let's see if this image is already cached? */
+        cached = manager_image_cache_get(m, name_or_path);
+        if (cached) {
+                *ret = cached;
+                return 1;
+        }
+
+        if (image_name_is_valid(name_or_path)) {
+
+                /* If it's a short name, let's search for it */
+                r = image_find(IMAGE_PORTABLE, name_or_path, &loaded);
+                if (r == -ENOENT)
+                        return sd_bus_error_setf(error, BUS_ERROR_NO_SUCH_PORTABLE_IMAGE, "No image '%s' found.", name_or_path);
+
+                /* other errors are handled below… */
+        } else {
+                /* Don't accept path if this is always forbidden */
+                if (mode == BUS_IMAGE_REFUSE_BY_PATH)
+                        return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Expected image name, not path in place of '%s'.", name_or_path);
+
+                if (!path_is_absolute(name_or_path))
+                        return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Image name '%s' is not valid or not a valid path.", name_or_path);
+
+                if (!path_is_normalized(name_or_path))
+                        return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Image path '%s' is not normalized.", name_or_path);
+
+                if (mode == BUS_IMAGE_AUTHENTICATE_BY_PATH) {
+                        r = bus_verify_polkit_async(
+                                        message,
+                                        CAP_SYS_ADMIN,
+                                        polkit_action,
+                                        NULL,
+                                        false,
+                                        UID_INVALID,
+                                        &m->polkit_registry,
+                                        error);
+                        if (r < 0)
+                                return r;
+                        if (r == 0) { /* Will call us back */
+                                *ret = NULL;
+                                return 0;
+                        }
+                }
+
+                r = image_from_path(name_or_path, &loaded);
+        }
+        if (r < 0)
+                return r;
+
+        /* Add what we just loaded to the cache. This has as side-effect that the object stays in memory until the
+         * cache is purged again, i.e. at least for the current event loop iteration, which is all we need, and which
+         * means we don't actually need to ref the return object. */
+        r = manager_image_cache_add(m, loaded);
+        if (r < 0)
+                return r;
+
+        *ret = loaded;
+        return 1;
+}
+
+int bus_image_object_find(
+                sd_bus *bus,
+                const char *path,
+                const char *interface,
+                void *userdata,
+                void **found,
+                sd_bus_error *error) {
+
+        _cleanup_free_ char *e = NULL;
+        Manager *m = userdata;
+        Image *image = NULL;
+        int r;
+
+        assert(bus);
+        assert(path);
+        assert(interface);
+        assert(found);
+
+        r = sd_bus_path_decode(path, "/org/freedesktop/portable1/image", &e);
+        if (r < 0)
+                return 0;
+        if (r == 0)
+                goto not_found;
+
+        r = bus_image_acquire(m, sd_bus_get_current_message(bus), e, NULL, BUS_IMAGE_REFUSE_BY_PATH, NULL, &image, error);
+        if (r == -ENOENT)
+                goto not_found;
+        if (r < 0)
+                return r;
+
+        *found = image;
+        return 1;
+
+not_found:
+        *found = NULL;
+        return 0;
+}
+
+int bus_image_node_enumerator(sd_bus *bus, const char *path, void *userdata, char ***nodes, sd_bus_error *error) {
+        _cleanup_(image_hashmap_freep) Hashmap *images = NULL;
+        _cleanup_strv_free_ char **l = NULL;
+        size_t n_allocated = 0, n = 0;
+        Manager *m = userdata;
+        Image *image;
+        Iterator i;
+        int r;
+
+        assert(bus);
+        assert(path);
+        assert(nodes);
+
+        images = hashmap_new(&string_hash_ops);
+        if (!images)
+                return -ENOMEM;
+
+        r = manager_image_cache_discover(m, images, error);
+        if (r < 0)
+                return r;
+
+        HASHMAP_FOREACH(image, images, i) {
+                char *p;
+
+                r = bus_image_path(image, &p);
+                if (r < 0)
+                        return r;
+
+                if (!GREEDY_REALLOC(l, n_allocated, n+2)) {
+                        free(p);
+                        return -ENOMEM;
+                }
+
+                l[n++] = p;
+                l[n] = NULL;
+        }
+
+        *nodes = TAKE_PTR(l);
+
+        return 1;
+}