-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
-/***
- This file is part of systemd.
-
- Copyright 2011 Lennart Poettering
-
- systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 2.1 of the License, or
- (at your option) any later version.
-
- systemd is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public License
- along with systemd; If not, see <http://www.gnu.org/licenses/>.
-***/
-
-#include <stdbool.h>
-#include <assert.h>
-#include <sys/epoll.h>
-#include <string.h>
-#include <errno.h>
-#include <sys/timerfd.h>
-#include <unistd.h>
-
-#include "dbus-loop.h"
-#include "dbus-common.h"
-#include "util.h"
-
-/* Minimal implementation of the dbus loop which integrates all dbus
- * events into a single epoll fd which we can triviall integrate with
- * other loops. Note that this is not used in the main systemd daemon
- * since we run a more elaborate mainloop there. */
-
-typedef struct EpollData {
- int fd;
- void *object;
- bool is_timeout:1;
- bool fd_is_dupped:1;
-} EpollData;
-
-static dbus_bool_t add_watch(DBusWatch *watch, void *data) {
- _cleanup_free_ EpollData *e = NULL;
- struct epoll_event ev = {};
-
- assert(watch);
-
- e = new0(EpollData, 1);
- if (!e)
- return FALSE;
-
- e->fd = dbus_watch_get_unix_fd(watch);
- e->object = watch;
- e->is_timeout = false;
-
- ev.events = bus_flags_to_events(watch);
- ev.data.ptr = e;
-
- if (epoll_ctl(PTR_TO_INT(data), EPOLL_CTL_ADD, e->fd, &ev) < 0) {
-
- if (errno != EEXIST)
- 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(). */
-
- e->fd = dup(e->fd);
- if (e->fd < 0)
- return FALSE;
-
- if (epoll_ctl(PTR_TO_INT(data), EPOLL_CTL_ADD, e->fd, &ev) < 0) {
- close_nointr_nofail(e->fd);
- return FALSE;
- }
-
- e->fd_is_dupped = true;
- }
-
- dbus_watch_set_data(watch, e, NULL);
- e = NULL; /* prevent freeing */
-
- return TRUE;
-}
-
-static void remove_watch(DBusWatch *watch, void *data) {
- _cleanup_free_ EpollData *e = NULL;
-
- assert(watch);
-
- e = dbus_watch_get_data(watch);
- if (!e)
- return;
-
- assert_se(epoll_ctl(PTR_TO_INT(data), EPOLL_CTL_DEL, e->fd, NULL) >= 0);
-
- if (e->fd_is_dupped)
- close_nointr_nofail(e->fd);
-}
-
-static void toggle_watch(DBusWatch *watch, void *data) {
- EpollData *e;
- struct epoll_event ev = {};
-
- assert(watch);
-
- e = dbus_watch_get_data(watch);
- if (!e)
- return;
-
- ev.data.ptr = e;
- ev.events = bus_flags_to_events(watch);
-
- assert_se(epoll_ctl(PTR_TO_INT(data), EPOLL_CTL_MOD, e->fd, &ev) == 0);
-}
-
-static int timeout_arm(EpollData *e) {
- struct itimerspec its = {};
-
- assert(e);
- assert(e->is_timeout);
-
- if (dbus_timeout_get_enabled(e->object)) {
- timespec_store(&its.it_value, dbus_timeout_get_interval(e->object) * USEC_PER_MSEC);
- its.it_interval = its.it_value;
- }
-
- if (timerfd_settime(e->fd, 0, &its, NULL) < 0)
- return -errno;
-
- return 0;
-}
-
-static dbus_bool_t add_timeout(DBusTimeout *timeout, void *data) {
- EpollData *e;
- struct epoll_event ev = {};
-
- assert(timeout);
-
- e = new0(EpollData, 1);
- if (!e)
- return FALSE;
-
- e->fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK|TFD_CLOEXEC);
- if (e->fd < 0)
- goto fail;
-
- e->object = timeout;
- e->is_timeout = true;
-
- if (timeout_arm(e) < 0)
- goto fail;
-
- ev.events = EPOLLIN;
- ev.data.ptr = e;
-
- if (epoll_ctl(PTR_TO_INT(data), EPOLL_CTL_ADD, e->fd, &ev) < 0)
- goto fail;
-
- dbus_timeout_set_data(timeout, e, NULL);
-
- return TRUE;
-
-fail:
- if (e->fd >= 0)
- close_nointr_nofail(e->fd);
-
- free(e);
- return FALSE;
-}
-
-static void remove_timeout(DBusTimeout *timeout, void *data) {
- _cleanup_free_ EpollData *e = NULL;
-
- assert(timeout);
-
- e = dbus_timeout_get_data(timeout);
- if (!e)
- return;
-
- assert_se(epoll_ctl(PTR_TO_INT(data), EPOLL_CTL_DEL, e->fd, NULL) >= 0);
- close_nointr_nofail(e->fd);
-}
-
-static void toggle_timeout(DBusTimeout *timeout, void *data) {
- EpollData *e;
- int r;
-
- assert(timeout);
-
- e = dbus_timeout_get_data(timeout);
- if (!e)
- return;
-
- r = timeout_arm(e);
- if (r < 0)
- log_error("Failed to rearm timer: %s", strerror(-r));
-}
-
-int bus_loop_open(DBusConnection *c) {
- int fd;
-
- assert(c);
-
- fd = epoll_create1(EPOLL_CLOEXEC);
- if (fd < 0)
- return -errno;
-
- if (!dbus_connection_set_watch_functions(c, add_watch, remove_watch, toggle_watch, INT_TO_PTR(fd), NULL) ||
- !dbus_connection_set_timeout_functions(c, add_timeout, remove_timeout, toggle_timeout, INT_TO_PTR(fd), NULL)) {
- close_nointr_nofail(fd);
- return -ENOMEM;
- }
-
- return fd;
-}
-
-int bus_loop_dispatch(int fd) {
- int n;
- struct epoll_event event = {};
- EpollData *d;
-
- assert(fd >= 0);
-
- n = epoll_wait(fd, &event, 1, 0);
- if (n < 0)
- return errno == EAGAIN || errno == EINTR ? 0 : -errno;
-
- assert_se(d = event.data.ptr);
-
- if (d->is_timeout) {
- DBusTimeout *t = d->object;
-
- if (dbus_timeout_get_enabled(t))
- dbus_timeout_handle(t);
- } else {
- DBusWatch *w = d->object;
-
- if (dbus_watch_get_enabled(w))
- dbus_watch_handle(w, bus_events_to_flags(event.events));
- }
-
- return 0;
-}
~ianmdlvl / elogind.git / commitdiff