chiark / gitweb /
bus-kernel: move bus_kernel_make_message
authorDaniel Mack <zonque@gmail.com>
Sat, 18 Jan 2014 19:06:21 +0000 (20:06 +0100)
committerDaniel Mack <zonque@gmail.com>
Sun, 19 Jan 2014 21:05:43 +0000 (22:05 +0100)
This makes future commits more readable.

src/libsystemd/bus-kernel.c

index d3eeb52..f85b4d5 100644 (file)
@@ -320,630 +320,630 @@ fail:
         return r;
 }
 
-int bus_kernel_take_fd(sd_bus *b) {
-        struct kdbus_cmd_hello *hello;
-        struct kdbus_item *item;
-        size_t l = 0, sz;
+static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k) {
+        sd_bus_message *m = NULL;
+        struct kdbus_item *d;
+        unsigned n_fds = 0;
+        _cleanup_free_ int *fds = NULL;
+        struct bus_header *h = NULL;
+        size_t total, n_bytes = 0, idx = 0;
+        const char *destination = NULL, *seclabel = NULL;
         int r;
 
-        assert(b);
+        assert(bus);
+        assert(k);
+        assert(k->payload_type == KDBUS_PAYLOAD_DBUS);
 
-        if (b->is_server)
-                return -EINVAL;
+        KDBUS_ITEM_FOREACH(d, k, items) {
+                size_t l;
 
-        b->use_memfd = 1;
+                l = d->size - offsetof(struct kdbus_item, data);
 
-        sz = ALIGN8(offsetof(struct kdbus_cmd_hello, items));
+                switch (d->type) {
 
-        if (b->fake_creds_valid)
-                sz += ALIGN8(offsetof(struct kdbus_item, creds)) + sizeof(struct kdbus_creds);
+                case KDBUS_ITEM_PAYLOAD_OFF:
+                        if (!h) {
+                                h = (struct bus_header *)((uint8_t *)k + d->vec.offset);
 
-        if (b->fake_label) {
-                l = strlen(b->fake_label);
-                sz += ALIGN8(offsetof(struct kdbus_item, str) + l + 1);
-        }
+                                if (!bus_header_is_complete(h, d->vec.size))
+                                        return -EBADMSG;
+                        }
 
-        hello = alloca0(sz);
-        hello->size = sz;
-        hello->conn_flags = b->hello_flags;
-        hello->attach_flags = b->attach_flags;
-        hello->pool_size = KDBUS_POOL_SIZE;
+                        n_bytes += d->vec.size;
+                        break;
 
-        item = hello->items;
+                case KDBUS_ITEM_PAYLOAD_MEMFD:
+                        if (!h)
+                                return -EBADMSG;
 
-        if (b->fake_creds_valid) {
-                item->size = offsetof(struct kdbus_item, creds) + sizeof(struct kdbus_creds);
-                item->type = KDBUS_ITEM_CREDS;
-                item->creds = b->fake_creds;
+                        n_bytes += d->memfd.size;
+                        break;
 
-                item = KDBUS_ITEM_NEXT(item);
-        }
+                case KDBUS_ITEM_FDS: {
+                        int *f;
+                        unsigned j;
 
-        if (b->fake_label) {
-                item->size = offsetof(struct kdbus_item, str) + l + 1;
-                memcpy(item->str, b->fake_label, l+1);
-        }
+                        j = l / sizeof(int);
+                        f = realloc(fds, sizeof(int) * (n_fds + j));
+                        if (!f)
+                                return -ENOMEM;
 
-        r = ioctl(b->input_fd, KDBUS_CMD_HELLO, hello);
-        if (r < 0)
-                return -errno;
+                        fds = f;
+                        memcpy(fds + n_fds, d->fds, sizeof(int) * j);
+                        n_fds += j;
+                        break;
+                }
 
-        if (!b->kdbus_buffer) {
-                b->kdbus_buffer = mmap(NULL, KDBUS_POOL_SIZE, PROT_READ, MAP_SHARED, b->input_fd, 0);
-                if (b->kdbus_buffer == MAP_FAILED) {
-                        b->kdbus_buffer = NULL;
-                        return -errno;
+                case KDBUS_ITEM_SECLABEL:
+                        seclabel = d->str;
+                        break;
                 }
         }
 
-        /* The higher 32bit of both flags fields are considered
-         * 'incompatible flags'. Refuse them all for now. */
-        if (hello->bus_flags > 0xFFFFFFFFULL ||
-            hello->conn_flags > 0xFFFFFFFFULL)
-                return -ENOTSUP;
-
-        if (hello->bloom_size != BLOOM_SIZE)
-                return -ENOTSUP;
-
-        if (asprintf(&b->unique_name, ":1.%llu", (unsigned long long) hello->id) < 0)
-                return -ENOMEM;
+        if (!h)
+                return -EBADMSG;
 
-        b->unique_id = hello->id;
+        r = bus_header_message_size(h, &total);
+        if (r < 0)
+                return r;
 
-        b->is_kernel = true;
-        b->bus_client = true;
-        b->can_fds = !!(hello->conn_flags & KDBUS_HELLO_ACCEPT_FD);
-        b->message_version = 2;
-        b->message_endian = BUS_NATIVE_ENDIAN;
+        if (n_bytes != total)
+                return -EBADMSG;
 
-        /* the kernel told us the UUID of the underlying bus */
-        memcpy(b->server_id.bytes, hello->id128, sizeof(b->server_id.bytes));
+        /* on kdbus we only speak native endian gvariant, never dbus1
+         * marshalling or reverse endian */
+        if (h->version != 2 ||
+            h->endian != BUS_NATIVE_ENDIAN)
+                return -EPROTOTYPE;
 
-        return bus_start_running(b);
-}
+        r = bus_message_from_header(bus, h, sizeof(struct bus_header), fds, n_fds, NULL, seclabel, 0, &m);
+        if (r < 0)
+                return r;
 
-int bus_kernel_connect(sd_bus *b) {
-        assert(b);
-        assert(b->input_fd < 0);
-        assert(b->output_fd < 0);
-        assert(b->kernel);
+        /* The well-known names list is different from the other
+        credentials. If we asked for it, but nothing is there, this
+        means that the list of well-known names is simply empty, not
+        that we lack any data */
 
-        if (b->is_server)
-                return -EINVAL;
+        m->creds.mask |= (SD_BUS_CREDS_UNIQUE_NAME|SD_BUS_CREDS_WELL_KNOWN_NAMES) & bus->creds_mask;
 
-        b->input_fd = open(b->kernel, O_RDWR|O_NOCTTY|O_CLOEXEC);
-        if (b->input_fd < 0)
-                return -errno;
+        KDBUS_ITEM_FOREACH(d, k, items) {
+                size_t l;
 
-        b->output_fd = b->input_fd;
+                l = d->size - offsetof(struct kdbus_item, data);
 
-        return bus_kernel_take_fd(b);
-}
+                switch (d->type) {
 
-int bus_kernel_write_message(sd_bus *bus, sd_bus_message *m) {
-        int r;
+                case KDBUS_ITEM_PAYLOAD_OFF: {
+                        size_t begin_body;
 
-        assert(bus);
-        assert(m);
-        assert(bus->state == BUS_RUNNING);
+                        begin_body = BUS_MESSAGE_BODY_BEGIN(m);
 
-        /* If we can't deliver, we want room for the error message */
-        r = bus_rqueue_make_room(bus);
-        if (r < 0)
-                return r;
+                        if (idx + d->vec.size > begin_body) {
+                                struct bus_body_part *part;
 
-        r = bus_message_setup_kmsg(bus, m);
-        if (r < 0)
-                return r;
+                                /* Contains body material */
 
-        r = ioctl(bus->output_fd, KDBUS_CMD_MSG_SEND, m->kdbus);
-        if (r < 0) {
-                _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
-                sd_bus_message *reply;
+                                part = message_append_part(m);
+                                if (!part) {
+                                        r = -ENOMEM;
+                                        goto fail;
+                                }
 
-                if (errno == EAGAIN || errno == EINTR)
-                        return 0;
-                else if (errno == ENXIO || errno == ESRCH) {
+                                /* A -1 offset is NUL padding. */
+                                part->is_zero = d->vec.offset == ~0ULL;
 
-                        /* ENXIO: unique name not known
-                         * ESRCH: well-known name not known */
+                                if (idx >= begin_body) {
+                                        if (!part->is_zero)
+                                                part->data = (uint8_t *)k + d->vec.offset;
+                                        part->size = d->vec.size;
+                                } else {
+                                        if (!part->is_zero)
+                                                part->data = (uint8_t *)k + d->vec.offset + (begin_body - idx);
+                                        part->size = d->vec.size - (begin_body - idx);
+                                }
 
-                        if (m->header->type == SD_BUS_MESSAGE_METHOD_CALL)
-                                sd_bus_error_setf(&error, SD_BUS_ERROR_SERVICE_UNKNOWN, "Destination %s not known", m->destination);
-                        else {
-                                log_debug("Could not deliver message to %s as destination is not known. Ignoring.", m->destination);
-                                return 0;
+                                part->sealed = true;
                         }
 
-                } else if (errno == EADDRNOTAVAIL) {
+                        idx += d->vec.size;
+                        break;
+                }
 
-                        /* EADDRNOTAVAIL: activation is possible, but turned off in request flags */
+                case KDBUS_ITEM_PAYLOAD_MEMFD: {
+                        struct bus_body_part *part;
 
-                        if (m->header->type == SD_BUS_MESSAGE_METHOD_CALL)
-                                sd_bus_error_setf(&error, SD_BUS_ERROR_SERVICE_UNKNOWN, "Activation of %s not requested", m->destination);
-                        else {
-                                log_debug("Could not deliver message to %s as destination is not activated. Ignoring.", m->destination);
-                                return 0;
+                        if (idx < BUS_MESSAGE_BODY_BEGIN(m)) {
+                                r = -EBADMSG;
+                                goto fail;
                         }
-                } else
-                        return -errno;
 
-                r = bus_message_new_synthetic_error(
-                                bus,
-                                BUS_MESSAGE_COOKIE(m),
-                                &error,
-                                &reply);
+                        part = message_append_part(m);
+                        if (!part) {
+                                r = -ENOMEM;
+                                goto fail;
+                        }
 
-                if (r < 0)
-                        return r;
+                        part->memfd = d->memfd.fd;
+                        part->size = d->memfd.size;
+                        part->sealed = true;
 
-                r = bus_seal_synthetic_message(bus, reply);
-                if (r < 0)
-                        return r;
+                        idx += d->memfd.size;
+                        break;
+                }
 
-                bus->rqueue[bus->rqueue_size++] = reply;
+                case KDBUS_ITEM_CREDS:
+                        /* UID/GID/PID are always valid */
+                        m->creds.uid = (uid_t) d->creds.uid;
+                        m->creds.gid = (gid_t) d->creds.gid;
+                        m->creds.pid = (pid_t) d->creds.pid;
+                        m->creds.mask |= (SD_BUS_CREDS_UID|SD_BUS_CREDS_GID|SD_BUS_CREDS_PID) & bus->creds_mask;
 
-                return 0;
-        }
+                        /* The PID starttime/TID might be missing
+                         * however, when the data is faked by some
+                         * data bus proxy and it lacks that
+                         * information about the real client since
+                         * SO_PEERCRED is used for that */
 
-        return 1;
-}
+                        if (d->creds.starttime > 0) {
+                                m->creds.pid_starttime = d->creds.starttime / NSEC_PER_USEC;
+                                m->creds.mask |= SD_BUS_CREDS_PID_STARTTIME & bus->creds_mask;
+                        }
 
-static void close_kdbus_msg(sd_bus *bus, struct kdbus_msg *k) {
-        uint64_t off;
-        struct kdbus_item *d;
+                        if (d->creds.tid > 0) {
+                                m->creds.tid = (pid_t) d->creds.tid;
+                                m->creds.mask |= SD_BUS_CREDS_TID & bus->creds_mask;
+                        }
+                        break;
 
-        assert(bus);
-        assert(k);
+                case KDBUS_ITEM_TIMESTAMP:
+                        m->realtime = d->timestamp.realtime_ns / NSEC_PER_USEC;
+                        m->monotonic = d->timestamp.monotonic_ns / NSEC_PER_USEC;
+                        break;
 
-        off = (uint8_t *)k - (uint8_t *)bus->kdbus_buffer;
-        ioctl(bus->input_fd, KDBUS_CMD_FREE, &off);
+                case KDBUS_ITEM_PID_COMM:
+                        m->creds.comm = d->str;
+                        m->creds.mask |= SD_BUS_CREDS_COMM & bus->creds_mask;
+                        break;
 
-        KDBUS_ITEM_FOREACH(d, k, items) {
+                case KDBUS_ITEM_TID_COMM:
+                        m->creds.tid_comm = d->str;
+                        m->creds.mask |= SD_BUS_CREDS_TID_COMM & bus->creds_mask;
+                        break;
 
-                if (d->type == KDBUS_ITEM_FDS)
-                        close_many(d->fds, (d->size - offsetof(struct kdbus_item, fds)) / sizeof(int));
-                else if (d->type == KDBUS_ITEM_PAYLOAD_MEMFD)
-                        close_nointr_nofail(d->memfd.fd);
-        }
-}
+                case KDBUS_ITEM_EXE:
+                        m->creds.exe = d->str;
+                        m->creds.mask |= SD_BUS_CREDS_EXE & bus->creds_mask;
+                        break;
 
-static int push_name_owner_changed(sd_bus *bus, const char *name, const char *old_owner, const char *new_owner) {
-        _cleanup_bus_message_unref_ sd_bus_message *m = NULL;
-        int r;
+                case KDBUS_ITEM_CMDLINE:
+                        m->creds.cmdline = d->str;
+                        m->creds.cmdline_size = l;
+                        m->creds.mask |= SD_BUS_CREDS_CMDLINE & bus->creds_mask;
+                        break;
 
-        assert(bus);
+                case KDBUS_ITEM_CGROUP:
+                        m->creds.cgroup = d->str;
+                        m->creds.mask |= (SD_BUS_CREDS_CGROUP|SD_BUS_CREDS_UNIT|SD_BUS_CREDS_USER_UNIT|SD_BUS_CREDS_SLICE|SD_BUS_CREDS_SESSION|SD_BUS_CREDS_OWNER_UID) & bus->creds_mask;
 
-        r = sd_bus_message_new_signal(
-                        bus,
-                        "/org/freedesktop/DBus",
-                        "org.freedesktop.DBus",
-                        "NameOwnerChanged",
-                        &m);
-        if (r < 0)
-                return r;
+                        if (!bus->cgroup_root) {
+                                r = cg_get_root_path(&bus->cgroup_root);
+                                if (r < 0)
+                                        goto fail;
+                        }
 
-        r = sd_bus_message_append(m, "sss", name, old_owner, new_owner);
-        if (r < 0)
-                return r;
+                        m->creds.cgroup_root = bus->cgroup_root;
 
-        m->sender = "org.freedesktop.DBus";
+                        break;
 
-        r = bus_seal_synthetic_message(bus, m);
-        if (r < 0)
-                return r;
+                case KDBUS_ITEM_AUDIT:
+                        m->creds.audit_session_id = (uint32_t) d->audit.sessionid;
+                        m->creds.audit_login_uid = (uid_t) d->audit.loginuid;
+                        m->creds.mask |= (SD_BUS_CREDS_AUDIT_SESSION_ID|SD_BUS_CREDS_AUDIT_LOGIN_UID) & bus->creds_mask;
+                        break;
 
-        bus->rqueue[bus->rqueue_size++] = m;
-        m = NULL;
+                case KDBUS_ITEM_CAPS:
+                        m->creds.capability = d->data;
+                        m->creds.capability_size = l;
+                        m->creds.mask |= (SD_BUS_CREDS_EFFECTIVE_CAPS|SD_BUS_CREDS_PERMITTED_CAPS|SD_BUS_CREDS_INHERITABLE_CAPS|SD_BUS_CREDS_BOUNDING_CAPS) & bus->creds_mask;
+                        break;
 
-        return 1;
-}
+                case KDBUS_ITEM_DST_NAME:
+                        if (!service_name_is_valid(d->str))
+                                return -EBADMSG;
 
-static int translate_name_change(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *d) {
-        char new_owner[UNIQUE_NAME_MAX], old_owner[UNIQUE_NAME_MAX];
+                        destination = d->str;
+                        break;
 
-        assert(bus);
-        assert(k);
-        assert(d);
+                case KDBUS_ITEM_NAME:
+                        if (!service_name_is_valid(d->name.name))
+                                return -EBADMSG;
 
-        if (d->type == KDBUS_ITEM_NAME_ADD || (d->name_change.old.flags & (KDBUS_NAME_IN_QUEUE|KDBUS_NAME_ACTIVATOR)))
-                old_owner[0] = 0;
-        else
-                sprintf(old_owner, ":1.%llu", (unsigned long long) d->name_change.old.id);
+                        r = strv_extend(&m->creds.well_known_names, d->name.name);
+                        if (r < 0)
+                                goto fail;
+                        break;
 
-        if (d->type == KDBUS_ITEM_NAME_REMOVE || (d->name_change.new.flags & (KDBUS_NAME_IN_QUEUE|KDBUS_NAME_ACTIVATOR))) {
+                case KDBUS_ITEM_FDS:
+                case KDBUS_ITEM_SECLABEL:
+                        break;
 
-                if (isempty(old_owner))
-                        return 0;
+                default:
+                        log_debug("Got unknown field from kernel %llu", d->type);
+                }
+        }
 
-                new_owner[0] = 0;
-        } else
-                sprintf(new_owner, ":1.%llu", (unsigned long long) d->name_change.new.id);
+        r = bus_message_parse_fields(m);
+        if (r < 0)
+                goto fail;
 
-        return push_name_owner_changed(bus, d->name_change.name, old_owner, new_owner);
-}
+        /* Override information from the user header with data from the kernel */
+        if (k->src_id == KDBUS_SRC_ID_KERNEL)
+                m->sender = m->creds.unique_name = (char*) "org.freedesktop.DBus";
+        else {
+                snprintf(m->sender_buffer, sizeof(m->sender_buffer), ":1.%llu", (unsigned long long) k->src_id);
+                m->sender = m->creds.unique_name = m->sender_buffer;
+        }
 
-static int translate_id_change(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *d) {
-        char owner[UNIQUE_NAME_MAX];
+        if (destination)
+                m->destination = destination;
+        else if (k->dst_id == KDBUS_DST_ID_BROADCAST)
+                m->destination = NULL;
+        else if (k->dst_id == KDBUS_DST_ID_NAME)
+                m->destination = bus->unique_name; /* fill in unique name if the well-known name is missing */
+        else {
+                snprintf(m->destination_buffer, sizeof(m->destination_buffer), ":1.%llu", (unsigned long long) k->dst_id);
+                m->destination = m->destination_buffer;
+        }
 
-        assert(bus);
-        assert(k);
-        assert(d);
+        /* We take possession of the kmsg struct now */
+        m->kdbus = k;
+        m->release_kdbus = true;
+        m->free_fds = true;
+        fds = NULL;
 
-        sprintf(owner, ":1.%llu", d->id_change.id);
+        bus->rqueue[bus->rqueue_size++] = m;
 
-        return push_name_owner_changed(
-                        bus, owner,
-                        d->type == KDBUS_ITEM_ID_ADD ? NULL : owner,
-                        d->type == KDBUS_ITEM_ID_ADD ? owner : NULL);
-}
+        return 1;
 
-static int translate_reply(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *d) {
-        _cleanup_bus_message_unref_ sd_bus_message *m = NULL;
-        int r;
+fail:
+        if (m) {
+                struct bus_body_part *part;
+                unsigned i;
 
-        assert(bus);
-        assert(k);
-        assert(d);
+                /* Make sure the memfds are not freed twice */
+                MESSAGE_FOREACH_PART(part, i, m)
+                        if (part->memfd >= 0)
+                                part->memfd = -1;
 
-        r = bus_message_new_synthetic_error(
-                        bus,
-                        k->cookie_reply,
-                        d->type == KDBUS_ITEM_REPLY_TIMEOUT ?
-                        &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_NO_REPLY, "Method call timed out") :
-                        &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_NO_REPLY, "Method call peer died"),
-                        &m);
-        if (r < 0)
-                return r;
+                sd_bus_message_unref(m);
+        }
 
-        m->sender = "org.freedesktop.DBus";
+        return r;
+}
 
-        r = bus_seal_synthetic_message(bus, m);
-        if (r < 0)
-                return r;
+int bus_kernel_take_fd(sd_bus *b) {
+        struct kdbus_cmd_hello *hello;
+        struct kdbus_item *item;
+        size_t l = 0, sz;
+        int r;
 
-        bus->rqueue[bus->rqueue_size++] = m;
-        m = NULL;
+        assert(b);
 
-        return 1;
-}
+        if (b->is_server)
+                return -EINVAL;
 
-static int bus_kernel_translate_message(sd_bus *bus, struct kdbus_msg *k) {
-        struct kdbus_item *d, *found = NULL;
+        b->use_memfd = 1;
 
-        static int (* const translate[])(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *d) = {
-                [KDBUS_ITEM_NAME_ADD - _KDBUS_ITEM_KERNEL_BASE] = translate_name_change,
-                [KDBUS_ITEM_NAME_REMOVE - _KDBUS_ITEM_KERNEL_BASE] = translate_name_change,
-                [KDBUS_ITEM_NAME_CHANGE - _KDBUS_ITEM_KERNEL_BASE] = translate_name_change,
+        sz = ALIGN8(offsetof(struct kdbus_cmd_hello, items));
 
-                [KDBUS_ITEM_ID_ADD - _KDBUS_ITEM_KERNEL_BASE] = translate_id_change,
-                [KDBUS_ITEM_ID_REMOVE - _KDBUS_ITEM_KERNEL_BASE] = translate_id_change,
+        if (b->fake_creds_valid)
+                sz += ALIGN8(offsetof(struct kdbus_item, creds)) + sizeof(struct kdbus_creds);
 
-                [KDBUS_ITEM_REPLY_TIMEOUT - _KDBUS_ITEM_KERNEL_BASE] = translate_reply,
-                [KDBUS_ITEM_REPLY_DEAD - _KDBUS_ITEM_KERNEL_BASE] = translate_reply,
-        };
+        if (b->fake_label) {
+                l = strlen(b->fake_label);
+                sz += ALIGN8(offsetof(struct kdbus_item, str) + l + 1);
+        }
 
-        assert(bus);
-        assert(k);
-        assert(k->payload_type == KDBUS_PAYLOAD_KERNEL);
+        hello = alloca0(sz);
+        hello->size = sz;
+        hello->conn_flags = b->hello_flags;
+        hello->attach_flags = b->attach_flags;
+        hello->pool_size = KDBUS_POOL_SIZE;
 
-        KDBUS_ITEM_FOREACH(d, k, items) {
-                if (d->type >= _KDBUS_ITEM_KERNEL_BASE && d->type < _KDBUS_ITEM_KERNEL_BASE + ELEMENTSOF(translate)) {
-                        if (found)
-                                return -EBADMSG;
-                        found = d;
-                } else
-                        log_debug("Got unknown field from kernel %llu", d->type);
+        item = hello->items;
+
+        if (b->fake_creds_valid) {
+                item->size = offsetof(struct kdbus_item, creds) + sizeof(struct kdbus_creds);
+                item->type = KDBUS_ITEM_CREDS;
+                item->creds = b->fake_creds;
+
+                item = KDBUS_ITEM_NEXT(item);
         }
 
-        if (!found) {
-                log_debug("Didn't find a kernel message to translate.");
-                return 0;
+        if (b->fake_label) {
+                item->size = offsetof(struct kdbus_item, str) + l + 1;
+                memcpy(item->str, b->fake_label, l+1);
         }
 
-        return translate[found->type - _KDBUS_ITEM_KERNEL_BASE](bus, k, found);
-}
+        r = ioctl(b->input_fd, KDBUS_CMD_HELLO, hello);
+        if (r < 0)
+                return -errno;
 
-static int bus_kernel_make_message(sd_bus *bus, struct kdbus_msg *k) {
-        sd_bus_message *m = NULL;
-        struct kdbus_item *d;
-        unsigned n_fds = 0;
-        _cleanup_free_ int *fds = NULL;
-        struct bus_header *h = NULL;
-        size_t total, n_bytes = 0, idx = 0;
-        const char *destination = NULL, *seclabel = NULL;
-        int r;
+        if (!b->kdbus_buffer) {
+                b->kdbus_buffer = mmap(NULL, KDBUS_POOL_SIZE, PROT_READ, MAP_SHARED, b->input_fd, 0);
+                if (b->kdbus_buffer == MAP_FAILED) {
+                        b->kdbus_buffer = NULL;
+                        return -errno;
+                }
+        }
 
-        assert(bus);
-        assert(k);
-        assert(k->payload_type == KDBUS_PAYLOAD_DBUS);
+        /* The higher 32bit of both flags fields are considered
+         * 'incompatible flags'. Refuse them all for now. */
+        if (hello->bus_flags > 0xFFFFFFFFULL ||
+            hello->conn_flags > 0xFFFFFFFFULL)
+                return -ENOTSUP;
 
-        KDBUS_ITEM_FOREACH(d, k, items) {
-                size_t l;
+        if (hello->bloom_size != BLOOM_SIZE)
+                return -ENOTSUP;
 
-                l = d->size - offsetof(struct kdbus_item, data);
+        if (asprintf(&b->unique_name, ":1.%llu", (unsigned long long) hello->id) < 0)
+                return -ENOMEM;
 
-                switch (d->type) {
+        b->unique_id = hello->id;
 
-                case KDBUS_ITEM_PAYLOAD_OFF:
-                        if (!h) {
-                                h = (struct bus_header *)((uint8_t *)k + d->vec.offset);
+        b->is_kernel = true;
+        b->bus_client = true;
+        b->can_fds = !!(hello->conn_flags & KDBUS_HELLO_ACCEPT_FD);
+        b->message_version = 2;
+        b->message_endian = BUS_NATIVE_ENDIAN;
 
-                                if (!bus_header_is_complete(h, d->vec.size))
-                                        return -EBADMSG;
-                        }
+        /* the kernel told us the UUID of the underlying bus */
+        memcpy(b->server_id.bytes, hello->id128, sizeof(b->server_id.bytes));
 
-                        n_bytes += d->vec.size;
-                        break;
+        return bus_start_running(b);
+}
 
-                case KDBUS_ITEM_PAYLOAD_MEMFD:
-                        if (!h)
-                                return -EBADMSG;
+int bus_kernel_connect(sd_bus *b) {
+        assert(b);
+        assert(b->input_fd < 0);
+        assert(b->output_fd < 0);
+        assert(b->kernel);
 
-                        n_bytes += d->memfd.size;
-                        break;
+        if (b->is_server)
+                return -EINVAL;
 
-                case KDBUS_ITEM_FDS: {
-                        int *f;
-                        unsigned j;
+        b->input_fd = open(b->kernel, O_RDWR|O_NOCTTY|O_CLOEXEC);
+        if (b->input_fd < 0)
+                return -errno;
 
-                        j = l / sizeof(int);
-                        f = realloc(fds, sizeof(int) * (n_fds + j));
-                        if (!f)
-                                return -ENOMEM;
+        b->output_fd = b->input_fd;
 
-                        fds = f;
-                        memcpy(fds + n_fds, d->fds, sizeof(int) * j);
-                        n_fds += j;
-                        break;
-                }
+        return bus_kernel_take_fd(b);
+}
 
-                case KDBUS_ITEM_SECLABEL:
-                        seclabel = d->str;
-                        break;
-                }
-        }
+int bus_kernel_write_message(sd_bus *bus, sd_bus_message *m) {
+        int r;
 
-        if (!h)
-                return -EBADMSG;
+        assert(bus);
+        assert(m);
+        assert(bus->state == BUS_RUNNING);
 
-        r = bus_header_message_size(h, &total);
+        /* If we can't deliver, we want room for the error message */
+        r = bus_rqueue_make_room(bus);
         if (r < 0)
                 return r;
 
-        if (n_bytes != total)
-                return -EBADMSG;
-
-        /* on kdbus we only speak native endian gvariant, never dbus1
-         * marshalling or reverse endian */
-        if (h->version != 2 ||
-            h->endian != BUS_NATIVE_ENDIAN)
-                return -EPROTOTYPE;
-
-        r = bus_message_from_header(bus, h, sizeof(struct bus_header), fds, n_fds, NULL, seclabel, 0, &m);
+        r = bus_message_setup_kmsg(bus, m);
         if (r < 0)
                 return r;
 
-        /* The well-known names list is different from the other
-        credentials. If we asked for it, but nothing is there, this
-        means that the list of well-known names is simply empty, not
-        that we lack any data */
-
-        m->creds.mask |= (SD_BUS_CREDS_UNIQUE_NAME|SD_BUS_CREDS_WELL_KNOWN_NAMES) & bus->creds_mask;
+        r = ioctl(bus->output_fd, KDBUS_CMD_MSG_SEND, m->kdbus);
+        if (r < 0) {
+                _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
+                sd_bus_message *reply;
 
-        KDBUS_ITEM_FOREACH(d, k, items) {
-                size_t l;
+                if (errno == EAGAIN || errno == EINTR)
+                        return 0;
+                else if (errno == ENXIO || errno == ESRCH) {
 
-                l = d->size - offsetof(struct kdbus_item, data);
+                        /* ENXIO: unique name not known
+                         * ESRCH: well-known name not known */
 
-                switch (d->type) {
+                        if (m->header->type == SD_BUS_MESSAGE_METHOD_CALL)
+                                sd_bus_error_setf(&error, SD_BUS_ERROR_SERVICE_UNKNOWN, "Destination %s not known", m->destination);
+                        else {
+                                log_debug("Could not deliver message to %s as destination is not known. Ignoring.", m->destination);
+                                return 0;
+                        }
 
-                case KDBUS_ITEM_PAYLOAD_OFF: {
-                        size_t begin_body;
+                } else if (errno == EADDRNOTAVAIL) {
 
-                        begin_body = BUS_MESSAGE_BODY_BEGIN(m);
+                        /* EADDRNOTAVAIL: activation is possible, but turned off in request flags */
 
-                        if (idx + d->vec.size > begin_body) {
-                                struct bus_body_part *part;
+                        if (m->header->type == SD_BUS_MESSAGE_METHOD_CALL)
+                                sd_bus_error_setf(&error, SD_BUS_ERROR_SERVICE_UNKNOWN, "Activation of %s not requested", m->destination);
+                        else {
+                                log_debug("Could not deliver message to %s as destination is not activated. Ignoring.", m->destination);
+                                return 0;
+                        }
+                } else
+                        return -errno;
 
-                                /* Contains body material */
+                r = bus_message_new_synthetic_error(
+                                bus,
+                                BUS_MESSAGE_COOKIE(m),
+                                &error,
+                                &reply);
 
-                                part = message_append_part(m);
-                                if (!part) {
-                                        r = -ENOMEM;
-                                        goto fail;
-                                }
+                if (r < 0)
+                        return r;
 
-                                /* A -1 offset is NUL padding. */
-                                part->is_zero = d->vec.offset == ~0ULL;
+                r = bus_seal_synthetic_message(bus, reply);
+                if (r < 0)
+                        return r;
 
-                                if (idx >= begin_body) {
-                                        if (!part->is_zero)
-                                                part->data = (uint8_t *)k + d->vec.offset;
-                                        part->size = d->vec.size;
-                                } else {
-                                        if (!part->is_zero)
-                                                part->data = (uint8_t *)k + d->vec.offset + (begin_body - idx);
-                                        part->size = d->vec.size - (begin_body - idx);
-                                }
+                bus->rqueue[bus->rqueue_size++] = reply;
 
-                                part->sealed = true;
-                        }
+                return 0;
+        }
 
-                        idx += d->vec.size;
-                        break;
-                }
+        return 1;
+}
 
-                case KDBUS_ITEM_PAYLOAD_MEMFD: {
-                        struct bus_body_part *part;
+static void close_kdbus_msg(sd_bus *bus, struct kdbus_msg *k) {
+        uint64_t off;
+        struct kdbus_item *d;
 
-                        if (idx < BUS_MESSAGE_BODY_BEGIN(m)) {
-                                r = -EBADMSG;
-                                goto fail;
-                        }
+        assert(bus);
+        assert(k);
 
-                        part = message_append_part(m);
-                        if (!part) {
-                                r = -ENOMEM;
-                                goto fail;
-                        }
+        off = (uint8_t *)k - (uint8_t *)bus->kdbus_buffer;
+        ioctl(bus->input_fd, KDBUS_CMD_FREE, &off);
 
-                        part->memfd = d->memfd.fd;
-                        part->size = d->memfd.size;
-                        part->sealed = true;
+        KDBUS_ITEM_FOREACH(d, k, items) {
 
-                        idx += d->memfd.size;
-                        break;
-                }
+                if (d->type == KDBUS_ITEM_FDS)
+                        close_many(d->fds, (d->size - offsetof(struct kdbus_item, fds)) / sizeof(int));
+                else if (d->type == KDBUS_ITEM_PAYLOAD_MEMFD)
+                        close_nointr_nofail(d->memfd.fd);
+        }
+}
 
-                case KDBUS_ITEM_CREDS:
-                        /* UID/GID/PID are always valid */
-                        m->creds.uid = (uid_t) d->creds.uid;
-                        m->creds.gid = (gid_t) d->creds.gid;
-                        m->creds.pid = (pid_t) d->creds.pid;
-                        m->creds.mask |= (SD_BUS_CREDS_UID|SD_BUS_CREDS_GID|SD_BUS_CREDS_PID) & bus->creds_mask;
+static int push_name_owner_changed(sd_bus *bus, const char *name, const char *old_owner, const char *new_owner) {
+        _cleanup_bus_message_unref_ sd_bus_message *m = NULL;
+        int r;
 
-                        /* The PID starttime/TID might be missing
-                         * however, when the data is faked by some
-                         * data bus proxy and it lacks that
-                         * information about the real client since
-                         * SO_PEERCRED is used for that */
+        assert(bus);
 
-                        if (d->creds.starttime > 0) {
-                                m->creds.pid_starttime = d->creds.starttime / NSEC_PER_USEC;
-                                m->creds.mask |= SD_BUS_CREDS_PID_STARTTIME & bus->creds_mask;
-                        }
+        r = sd_bus_message_new_signal(
+                        bus,
+                        "/org/freedesktop/DBus",
+                        "org.freedesktop.DBus",
+                        "NameOwnerChanged",
+                        &m);
+        if (r < 0)
+                return r;
 
-                        if (d->creds.tid > 0) {
-                                m->creds.tid = (pid_t) d->creds.tid;
-                                m->creds.mask |= SD_BUS_CREDS_TID & bus->creds_mask;
-                        }
-                        break;
+        r = sd_bus_message_append(m, "sss", name, old_owner, new_owner);
+        if (r < 0)
+                return r;
 
-                case KDBUS_ITEM_TIMESTAMP:
-                        m->realtime = d->timestamp.realtime_ns / NSEC_PER_USEC;
-                        m->monotonic = d->timestamp.monotonic_ns / NSEC_PER_USEC;
-                        break;
+        m->sender = "org.freedesktop.DBus";
 
-                case KDBUS_ITEM_PID_COMM:
-                        m->creds.comm = d->str;
-                        m->creds.mask |= SD_BUS_CREDS_COMM & bus->creds_mask;
-                        break;
+        r = bus_seal_synthetic_message(bus, m);
+        if (r < 0)
+                return r;
 
-                case KDBUS_ITEM_TID_COMM:
-                        m->creds.tid_comm = d->str;
-                        m->creds.mask |= SD_BUS_CREDS_TID_COMM & bus->creds_mask;
-                        break;
+        bus->rqueue[bus->rqueue_size++] = m;
+        m = NULL;
 
-                case KDBUS_ITEM_EXE:
-                        m->creds.exe = d->str;
-                        m->creds.mask |= SD_BUS_CREDS_EXE & bus->creds_mask;
-                        break;
+        return 1;
+}
 
-                case KDBUS_ITEM_CMDLINE:
-                        m->creds.cmdline = d->str;
-                        m->creds.cmdline_size = l;
-                        m->creds.mask |= SD_BUS_CREDS_CMDLINE & bus->creds_mask;
-                        break;
+static int translate_name_change(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *d) {
+        char new_owner[UNIQUE_NAME_MAX], old_owner[UNIQUE_NAME_MAX];
 
-                case KDBUS_ITEM_CGROUP:
-                        m->creds.cgroup = d->str;
-                        m->creds.mask |= (SD_BUS_CREDS_CGROUP|SD_BUS_CREDS_UNIT|SD_BUS_CREDS_USER_UNIT|SD_BUS_CREDS_SLICE|SD_BUS_CREDS_SESSION|SD_BUS_CREDS_OWNER_UID) & bus->creds_mask;
+        assert(bus);
+        assert(k);
+        assert(d);
 
-                        if (!bus->cgroup_root) {
-                                r = cg_get_root_path(&bus->cgroup_root);
-                                if (r < 0)
-                                        goto fail;
-                        }
+        if (d->type == KDBUS_ITEM_NAME_ADD || (d->name_change.old.flags & (KDBUS_NAME_IN_QUEUE|KDBUS_NAME_ACTIVATOR)))
+                old_owner[0] = 0;
+        else
+                sprintf(old_owner, ":1.%llu", (unsigned long long) d->name_change.old.id);
 
-                        m->creds.cgroup_root = bus->cgroup_root;
+        if (d->type == KDBUS_ITEM_NAME_REMOVE || (d->name_change.new.flags & (KDBUS_NAME_IN_QUEUE|KDBUS_NAME_ACTIVATOR))) {
 
-                        break;
+                if (isempty(old_owner))
+                        return 0;
 
-                case KDBUS_ITEM_AUDIT:
-                        m->creds.audit_session_id = (uint32_t) d->audit.sessionid;
-                        m->creds.audit_login_uid = (uid_t) d->audit.loginuid;
-                        m->creds.mask |= (SD_BUS_CREDS_AUDIT_SESSION_ID|SD_BUS_CREDS_AUDIT_LOGIN_UID) & bus->creds_mask;
-                        break;
+                new_owner[0] = 0;
+        } else
+                sprintf(new_owner, ":1.%llu", (unsigned long long) d->name_change.new.id);
 
-                case KDBUS_ITEM_CAPS:
-                        m->creds.capability = d->data;
-                        m->creds.capability_size = l;
-                        m->creds.mask |= (SD_BUS_CREDS_EFFECTIVE_CAPS|SD_BUS_CREDS_PERMITTED_CAPS|SD_BUS_CREDS_INHERITABLE_CAPS|SD_BUS_CREDS_BOUNDING_CAPS) & bus->creds_mask;
-                        break;
+        return push_name_owner_changed(bus, d->name_change.name, old_owner, new_owner);
+}
 
-                case KDBUS_ITEM_DST_NAME:
-                        if (!service_name_is_valid(d->str))
-                                return -EBADMSG;
+static int translate_id_change(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *d) {
+        char owner[UNIQUE_NAME_MAX];
 
-                        destination = d->str;
-                        break;
+        assert(bus);
+        assert(k);
+        assert(d);
 
-                case KDBUS_ITEM_NAME:
-                        if (!service_name_is_valid(d->name.name))
-                                return -EBADMSG;
+        sprintf(owner, ":1.%llu", d->id_change.id);
 
-                        r = strv_extend(&m->creds.well_known_names, d->name.name);
-                        if (r < 0)
-                                goto fail;
-                        break;
+        return push_name_owner_changed(
+                        bus, owner,
+                        d->type == KDBUS_ITEM_ID_ADD ? NULL : owner,
+                        d->type == KDBUS_ITEM_ID_ADD ? owner : NULL);
+}
 
-                case KDBUS_ITEM_FDS:
-                case KDBUS_ITEM_SECLABEL:
-                        break;
+static int translate_reply(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *d) {
+        _cleanup_bus_message_unref_ sd_bus_message *m = NULL;
+        int r;
 
-                default:
-                        log_debug("Got unknown field from kernel %llu", d->type);
-                }
-        }
+        assert(bus);
+        assert(k);
+        assert(d);
 
-        r = bus_message_parse_fields(m);
+        r = bus_message_new_synthetic_error(
+                        bus,
+                        k->cookie_reply,
+                        d->type == KDBUS_ITEM_REPLY_TIMEOUT ?
+                        &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_NO_REPLY, "Method call timed out") :
+                        &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_NO_REPLY, "Method call peer died"),
+                        &m);
         if (r < 0)
-                goto fail;
-
-        /* Override information from the user header with data from the kernel */
-        if (k->src_id == KDBUS_SRC_ID_KERNEL)
-                m->sender = m->creds.unique_name = (char*) "org.freedesktop.DBus";
-        else {
-                snprintf(m->sender_buffer, sizeof(m->sender_buffer), ":1.%llu", (unsigned long long) k->src_id);
-                m->sender = m->creds.unique_name = m->sender_buffer;
-        }
+                return r;
 
-        if (destination)
-                m->destination = destination;
-        else if (k->dst_id == KDBUS_DST_ID_BROADCAST)
-                m->destination = NULL;
-        else if (k->dst_id == KDBUS_DST_ID_NAME)
-                m->destination = bus->unique_name; /* fill in unique name if the well-known name is missing */
-        else {
-                snprintf(m->destination_buffer, sizeof(m->destination_buffer), ":1.%llu", (unsigned long long) k->dst_id);
-                m->destination = m->destination_buffer;
-        }
+        m->sender = "org.freedesktop.DBus";
 
-        /* We take possession of the kmsg struct now */
-        m->kdbus = k;
-        m->release_kdbus = true;
-        m->free_fds = true;
-        fds = NULL;
+        r = bus_seal_synthetic_message(bus, m);
+        if (r < 0)
+                return r;
 
         bus->rqueue[bus->rqueue_size++] = m;
+        m = NULL;
 
         return 1;
+}
 
-fail:
-        if (m) {
-                struct bus_body_part *part;
-                unsigned i;
+static int bus_kernel_translate_message(sd_bus *bus, struct kdbus_msg *k) {
+        struct kdbus_item *d, *found = NULL;
 
-                /* Make sure the memfds are not freed twice */
-                MESSAGE_FOREACH_PART(part, i, m)
-                        if (part->memfd >= 0)
-                                part->memfd = -1;
+        static int (* const translate[])(sd_bus *bus, struct kdbus_msg *k, struct kdbus_item *d) = {
+                [KDBUS_ITEM_NAME_ADD - _KDBUS_ITEM_KERNEL_BASE] = translate_name_change,
+                [KDBUS_ITEM_NAME_REMOVE - _KDBUS_ITEM_KERNEL_BASE] = translate_name_change,
+                [KDBUS_ITEM_NAME_CHANGE - _KDBUS_ITEM_KERNEL_BASE] = translate_name_change,
 
-                sd_bus_message_unref(m);
+                [KDBUS_ITEM_ID_ADD - _KDBUS_ITEM_KERNEL_BASE] = translate_id_change,
+                [KDBUS_ITEM_ID_REMOVE - _KDBUS_ITEM_KERNEL_BASE] = translate_id_change,
+
+                [KDBUS_ITEM_REPLY_TIMEOUT - _KDBUS_ITEM_KERNEL_BASE] = translate_reply,
+                [KDBUS_ITEM_REPLY_DEAD - _KDBUS_ITEM_KERNEL_BASE] = translate_reply,
+        };
+
+        assert(bus);
+        assert(k);
+        assert(k->payload_type == KDBUS_PAYLOAD_KERNEL);
+
+        KDBUS_ITEM_FOREACH(d, k, items) {
+                if (d->type >= _KDBUS_ITEM_KERNEL_BASE && d->type < _KDBUS_ITEM_KERNEL_BASE + ELEMENTSOF(translate)) {
+                        if (found)
+                                return -EBADMSG;
+                        found = d;
+                } else
+                        log_debug("Got unknown field from kernel %llu", d->type);
         }
 
-        return r;
+        if (!found) {
+                log_debug("Didn't find a kernel message to translate.");
+                return 0;
+        }
+
+        return translate[found->type - _KDBUS_ITEM_KERNEL_BASE](bus, k, found);
 }
 
 int bus_kernel_read_message(sd_bus *bus) {