diff options
Diffstat (limited to 'dbus.c')
| -rw-r--r-- | dbus.c | 608 |
1 files changed, 608 insertions, 0 deletions
diff --git a/dbus.c b/dbus.c new file mode 100644 index 0000000000..17987210e6 --- /dev/null +++ b/dbus.c @@ -0,0 +1,608 @@ +/*-*- Mode: C; c-basic-offset: 8 -*-*/ + +#include <dbus/dbus.h> + +#include <sys/epoll.h> +#include <sys/timerfd.h> +#include <errno.h> +#include <unistd.h> + +#include "dbus.h" +#include "log.h" +#include "strv.h" + +static void bus_dispatch_status(DBusConnection *bus, DBusDispatchStatus status, void *data) { + Manager *m = data; + + assert(bus); + assert(m); + + m->request_bus_dispatch = status != DBUS_DISPATCH_COMPLETE; +} + +static uint32_t bus_flags_to_events(DBusWatch *bus_watch) { + unsigned flags; + uint32_t events = 0; + + assert(bus_watch); + + /* no watch flags for disabled watches */ + if (!dbus_watch_get_enabled(bus_watch)) + return 0; + + flags = dbus_watch_get_flags(bus_watch); + + if (flags & DBUS_WATCH_READABLE) + events |= EPOLLIN; + if (flags & DBUS_WATCH_WRITABLE) + events |= EPOLLOUT; + + return events | EPOLLHUP | EPOLLERR; +} + +static unsigned events_to_bus_flags(uint32_t events) { + unsigned flags = 0; + + if (events & EPOLLIN) + flags |= DBUS_WATCH_READABLE; + if (events & EPOLLOUT) + flags |= DBUS_WATCH_WRITABLE; + if (events & EPOLLHUP) + flags |= DBUS_WATCH_HANGUP; + if (events & EPOLLERR) + flags |= DBUS_WATCH_ERROR; + + return flags; +} + +void bus_watch_event(Manager *m, Watch *w, int events) { + assert(m); + assert(w); + + /* This is called by the event loop whenever there is + * something happening on D-Bus' file handles. */ + + if (!(dbus_watch_get_enabled(w->data.bus_watch))) + return; + + dbus_watch_handle(w->data.bus_watch, events_to_bus_flags(events)); +} + +static dbus_bool_t bus_add_watch(DBusWatch *bus_watch, void *data) { + Manager *m = data; + Watch *w; + struct epoll_event ev; + + assert(bus_watch); + assert(m); + + if (!(w = new0(Watch, 1))) + return FALSE; + + w->fd = dbus_watch_get_unix_fd(bus_watch); + w->type = WATCH_DBUS_WATCH; + w->data.bus_watch = bus_watch; + + zero(ev); + ev.events = bus_flags_to_events(bus_watch); + ev.data.ptr = w; + + if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, w->fd, &ev) < 0) { + + if (errno != EEXIST) { + free(w); + return FALSE; + } + + /* Hmm, bloody D-Bus creates multiple watches on the + * same fd. epoll() does not like that. As a dirty + * hack we simply dup() the fd and hence get a second + * one we can safely add to the epoll(). */ + + if ((w->fd = dup(w->fd)) < 0) { + free(w); + return FALSE; + } + + if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, w->fd, &ev) < 0) { + free(w); + close_nointr_nofail(w->fd); + return FALSE; + } + + w->fd_is_dupped = true; + } + + dbus_watch_set_data(bus_watch, w, NULL); + + return TRUE; +} + +static void bus_remove_watch(DBusWatch *bus_watch, void *data) { + Manager *m = data; + Watch *w; + + assert(bus_watch); + assert(m); + + if (!(w = dbus_watch_get_data(bus_watch))) + return; + + assert(w->type == WATCH_DBUS_WATCH); + assert_se(epoll_ctl(m->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0); + + if (w->fd_is_dupped) + close_nointr_nofail(w->fd); + + free(w); +} + +static void bus_toggle_watch(DBusWatch *bus_watch, void *data) { + Manager *m = data; + Watch *w; + struct epoll_event ev; + + assert(bus_watch); + assert(m); + + assert_se(w = dbus_watch_get_data(bus_watch)); + assert(w->type == WATCH_DBUS_WATCH); + + zero(ev); + ev.events = bus_flags_to_events(bus_watch); + ev.data.ptr = w; + + assert_se(epoll_ctl(m->epoll_fd, EPOLL_CTL_MOD, w->fd, &ev) == 0); +} + +static int bus_timeout_arm(Manager *m, Watch *w) { + struct itimerspec its; + + assert(m); + assert(w); + + zero(its); + + if (dbus_timeout_get_enabled(w->data.bus_timeout)) { + timespec_store(&its.it_value, dbus_timeout_get_interval(w->data.bus_timeout) * USEC_PER_MSEC); + its.it_interval = its.it_interval; + } + + if (timerfd_settime(w->fd, 0, &its, NULL) < 0) + return -errno; + + return 0; +} + +void bus_timeout_event(Manager *m, Watch *w, int events) { + assert(m); + assert(w); + + /* This is called by the event loop whenever there is + * something happening on D-Bus' file handles. */ + + if (!(dbus_timeout_get_enabled(w->data.bus_timeout))) + return; + + dbus_timeout_handle(w->data.bus_timeout); +} + +static dbus_bool_t bus_add_timeout(DBusTimeout *timeout, void *data) { + Manager *m = data; + Watch *w; + struct epoll_event ev; + + assert(timeout); + assert(m); + + if (!(w = new0(Watch, 1))) + return FALSE; + + if (!(w->fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK|TFD_CLOEXEC)) < 0) + goto fail; + + w->type = WATCH_DBUS_TIMEOUT; + w->data.bus_timeout = timeout; + + if (bus_timeout_arm(m, w) < 0) + goto fail; + + zero(ev); + ev.events = EPOLLIN; + ev.data.ptr = w; + + if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, w->fd, &ev) < 0) + goto fail; + + dbus_timeout_set_data(timeout, w, NULL); + + return TRUE; + +fail: + if (w->fd >= 0) + close_nointr_nofail(w->fd); + + free(w); + return FALSE; +} + +static void bus_remove_timeout(DBusTimeout *timeout, void *data) { + Manager *m = data; + Watch *w; + + assert(timeout); + assert(m); + + if (!(w = dbus_timeout_get_data(timeout))) + return; + + assert(w->type == WATCH_DBUS_TIMEOUT); + assert_se(epoll_ctl(m->epoll_fd, EPOLL_CTL_DEL, w->fd, NULL) >= 0); + close_nointr_nofail(w->fd); + free(w); +} + +static void bus_toggle_timeout(DBusTimeout *timeout, void *data) { + Manager *m = data; + Watch *w; + int r; + + assert(timeout); + assert(m); + + assert_se(w = dbus_timeout_get_data(timeout)); + assert(w->type == WATCH_DBUS_TIMEOUT); + + if ((r = bus_timeout_arm(m, w)) < 0) + log_error("Failed to rearm timer: %s", strerror(-r)); +} + +void bus_dispatch(Manager *m) { + assert(m); + + if (dbus_connection_dispatch(m->bus) == DBUS_DISPATCH_COMPLETE) + m->request_bus_dispatch = false; +} + +static int request_name(Manager *m) { + DBusMessage *message; + const char *name = "org.freedesktop.systemd1"; + uint32_t flags = 0; + + if (!(message = dbus_message_new_method_call( + DBUS_SERVICE_DBUS, + DBUS_PATH_DBUS, + DBUS_INTERFACE_DBUS, + "RequestName"))) + return -ENOMEM; + + if (!dbus_message_append_args( + message, + DBUS_TYPE_STRING, &name, + DBUS_TYPE_UINT32, &flags, + DBUS_TYPE_INVALID)) { + dbus_message_unref(message); + return -ENOMEM; + } + + if (!dbus_connection_send(m->bus, message, NULL)) { + dbus_message_unref(message); + return -ENOMEM; + } + + /* We simple ask for the name and don't wait for it. Sooner or + * later we'll have it, and we wouldn't know what to do on + * error anyway. */ + + dbus_message_unref(message); + + return 0; +} + +int bus_init(Manager *m) { + DBusError error; + char *id; + int r; + + assert(m); + + if (m->bus) + return 0; + + dbus_connection_set_change_sigpipe(FALSE); + + dbus_error_init(&error); + if (!(m->bus = dbus_bus_get_private(m->is_init ? DBUS_BUS_SYSTEM : DBUS_BUS_SESSION, &error))) { + log_error("Failed to get D-Bus connection: %s", error.message); + dbus_error_free(&error); + return -ECONNREFUSED; + } + + dbus_connection_set_exit_on_disconnect(m->bus, FALSE); + dbus_connection_set_dispatch_status_function(m->bus, bus_dispatch_status, m, NULL); + if (!dbus_connection_set_watch_functions(m->bus, bus_add_watch, bus_remove_watch, bus_toggle_watch, m, NULL) || + !dbus_connection_set_timeout_functions(m->bus, bus_add_timeout, bus_remove_timeout, bus_toggle_timeout, m, NULL) || + !dbus_connection_register_object_path(m->bus, "/org/freedesktop/systemd1", &bus_manager_vtable, m) || + !dbus_connection_register_fallback(m->bus, "/org/freedesktop/systemd1/unit", &bus_unit_vtable, m) || + !dbus_connection_register_fallback(m->bus, "/org/freedesktop/systemd1/job", &bus_job_vtable, m)) { + bus_done(m); + return -ENOMEM; + } + + if ((r = request_name(m)) < 0) { + bus_done(m); + return r; + } + + log_debug("Successfully connected to D-Bus bus %s as %s", + strnull((id = dbus_connection_get_server_id(m->bus))), + strnull(dbus_bus_get_unique_name(m->bus))); + dbus_free(id); + + m->request_bus_dispatch = true; + + return 0; +} + +void bus_done(Manager *m) { + assert(m); + + if (m->bus) { + dbus_connection_close(m->bus); + dbus_connection_unref(m->bus); + m->bus = NULL; + } +} + +DBusHandlerResult bus_default_message_handler(Manager *m, DBusMessage *message, const char*introspection, const BusProperty *properties) { + DBusError error; + DBusMessage *reply = NULL; + int r; + + assert(m); + assert(message); + + dbus_error_init(&error); + + if (dbus_message_is_method_call(message, "org.freedesktop.DBus.Introspectable", "Introspect") && introspection) { + + if (!(reply = dbus_message_new_method_return(message))) + goto oom; + + if (!dbus_message_append_args(reply, DBUS_TYPE_STRING, &introspection, DBUS_TYPE_INVALID)) + goto oom; + + } else if (dbus_message_is_method_call(message, "org.freedesktop.DBus.Properties", "Get") && properties) { + const char *interface, *property; + const BusProperty *p; + + if (!dbus_message_get_args( + message, + &error, + DBUS_TYPE_STRING, &interface, + DBUS_TYPE_STRING, &property, + DBUS_TYPE_INVALID)) + return bus_send_error_reply(m, message, &error, -EINVAL); + + for (p = properties; p->property; p++) + if (streq(p->interface, interface) && streq(p->property, property)) + break; + + if (p->property) { + DBusMessageIter iter, sub; + + if (!(reply = dbus_message_new_method_return(message))) + goto oom; + + dbus_message_iter_init_append(reply, &iter); + + if (!dbus_message_iter_open_container(&iter, DBUS_TYPE_VARIANT, p->signature, &sub)) + goto oom; + + if ((r = p->append(m, &sub, property, p->data)) < 0) { + + if (r == -ENOMEM) + goto oom; + + dbus_message_unref(reply); + return bus_send_error_reply(m, message, NULL, r); + } + + if (!dbus_message_iter_close_container(&iter, &sub)) + goto oom; + } + } else if (dbus_message_is_method_call(message, "org.freedesktop.DBus.Properties", "GetAll") && properties) { + const char *interface; + const BusProperty *p; + DBusMessageIter iter, sub, sub2, sub3; + bool any = false; + + if (!dbus_message_get_args( + message, + &error, + DBUS_TYPE_STRING, &interface, + DBUS_TYPE_INVALID)) + return bus_send_error_reply(m, message, &error, -EINVAL); + + if (!(reply = dbus_message_new_method_return(message))) + goto oom; + + dbus_message_iter_init_append(reply, &iter); + + if (!dbus_message_iter_open_container(&iter, DBUS_TYPE_ARRAY, "{sv}", &sub)) + goto oom; + + for (p = properties; p->property; p++) { + if (!streq(p->interface, interface)) + continue; + + if (!dbus_message_iter_open_container(&sub, DBUS_TYPE_DICT_ENTRY, "sv" , &sub2) || + !dbus_message_iter_append_basic(&sub2, DBUS_TYPE_STRING, &p->property) || + !dbus_message_iter_open_container(&sub2, DBUS_TYPE_VARIANT, p->signature, &sub3)) + goto oom; + + if ((r = p->append(m, &sub3, p->property, p->data)) < 0) { + + if (r == -ENOMEM) + goto oom; + + dbus_message_unref(reply); + return bus_send_error_reply(m, message, NULL, r); + } + + if (!dbus_message_iter_close_container(&sub2, &sub3) || + !dbus_message_iter_close_container(&sub, &sub2)) + goto oom; + + any = true; + } + + if (!dbus_message_iter_close_container(&iter, &sub)) + goto oom; + } + + if (reply) { + if (!dbus_connection_send(m->bus, reply, NULL)) + goto oom; + + dbus_message_unref(reply); + return DBUS_HANDLER_RESULT_HANDLED; + } + + return DBUS_HANDLER_RESULT_NOT_YET_HANDLED; + +oom: + if (reply) + dbus_message_unref(reply); + + dbus_error_free(&error); + + return DBUS_HANDLER_RESULT_NEED_MEMORY; +} + + + +static const char *error_to_dbus(int error) { + + switch(error) { + + case -EINVAL: + return DBUS_ERROR_INVALID_ARGS; + + case -ENOMEM: + return DBUS_ERROR_NO_MEMORY; + + case -EPERM: + case -EACCES: + return DBUS_ERROR_ACCESS_DENIED; + + case -ESRCH: + return DBUS_ERROR_UNIX_PROCESS_ID_UNKNOWN; + + case -ENOENT: + return DBUS_ERROR_FILE_NOT_FOUND; + + case -EEXIST: + return DBUS_ERROR_FILE_EXISTS; + + case -ETIMEDOUT: + return DBUS_ERROR_TIMEOUT; + + case -EIO: + return DBUS_ERROR_IO_ERROR; + + case -ENETRESET: + case -ECONNABORTED: + case -ECONNRESET: + return DBUS_ERROR_DISCONNECTED; + } + + return DBUS_ERROR_FAILED; +} + +DBusHandlerResult bus_send_error_reply(Manager *m, DBusMessage *message, DBusError *bus_error, int error) { + DBusMessage *reply = NULL; + const char *name, *text; + + if (bus_error && dbus_error_is_set(bus_error)) { + name = bus_error->name; + text = bus_error->message; + } else { + name = error_to_dbus(error); + text = strerror(-error); + } + + if (!(reply = dbus_message_new_error(message, name, text))) + goto oom; + + if (!dbus_connection_send(m->bus, reply, NULL)) + goto oom; + + dbus_message_unref(reply); + + if (bus_error) + dbus_error_free(bus_error); + + return DBUS_HANDLER_RESULT_HANDLED; + +oom: + if (reply) + dbus_message_unref(reply); + + if (bus_error) + dbus_error_free(bus_error); + + return DBUS_HANDLER_RESULT_NEED_MEMORY; +} + +int bus_property_append_string(Manager *m, DBusMessageIter *i, const char *property, void *data) { + const char *t = data; + + assert(m); + assert(i); + assert(property); + assert(t); + + if (!dbus_message_iter_append_basic(i, DBUS_TYPE_STRING, &t)) + return -ENOMEM; + + return 0; +} + +int bus_property_append_strv(Manager *m, DBusMessageIter *i, const char *property, void *data) { + DBusMessageIter sub; + char **t = data; + + assert(m); + assert(i); + assert(property); + + if (!dbus_message_iter_open_container(i, DBUS_TYPE_ARRAY, "s", &sub)) + return -ENOMEM; + + STRV_FOREACH(t, t) + if (!dbus_message_iter_append_basic(&sub, DBUS_TYPE_STRING, t)) + return -ENOMEM; + + if (!dbus_message_iter_close_container(i, &sub)) + return -ENOMEM; + + return 0; +} + +int bus_property_append_bool(Manager *m, DBusMessageIter *i, const char *property, void *data) { + bool *b = data; + dbus_bool_t db; + + assert(m); + assert(i); + assert(property); + assert(b); + + db = *b; + + if (!dbus_message_iter_append_basic(i, DBUS_TYPE_BOOLEAN, &db)) + return -ENOMEM; + + return 0; +} |