860 lines
31 KiB
C
860 lines
31 KiB
C
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
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/***
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This file is part of systemd.
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Copyright (C) 2014 David Herrmann <dh.herrmann@gmail.com>
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systemd is free software; you can redistribute it and/or modify it
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under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2.1 of the License, or
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(at your option) any later version.
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systemd is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with systemd; If not, see <http://www.gnu.org/licenses/>.
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***/
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#include <fcntl.h>
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#include <libevdev/libevdev.h>
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#include <libudev.h>
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#include <stdbool.h>
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#include <stdlib.h>
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#include "sd-bus.h"
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#include "sd-event.h"
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#include "macro.h"
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#include "util.h"
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#include "bus-util.h"
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#include "idev.h"
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#include "idev-internal.h"
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typedef struct idev_evdev idev_evdev;
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typedef struct unmanaged_evdev unmanaged_evdev;
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typedef struct managed_evdev managed_evdev;
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struct idev_evdev {
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idev_element element;
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struct libevdev *evdev;
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int fd;
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sd_event_source *fd_src;
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sd_event_source *idle_src;
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bool unsync : 1; /* not in-sync with kernel */
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bool resync : 1; /* re-syncing with kernel */
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bool running : 1;
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};
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struct unmanaged_evdev {
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idev_evdev evdev;
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char *devnode;
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};
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struct managed_evdev {
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idev_evdev evdev;
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dev_t devnum;
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sd_bus_slot *slot_take_device;
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bool requested : 1; /* TakeDevice() was sent */
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bool acquired : 1; /* TakeDevice() was successful */
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};
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#define idev_evdev_from_element(_e) container_of((_e), idev_evdev, element)
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#define unmanaged_evdev_from_element(_e) \
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container_of(idev_evdev_from_element(_e), unmanaged_evdev, evdev)
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#define managed_evdev_from_element(_e) \
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container_of(idev_evdev_from_element(_e), managed_evdev, evdev)
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#define IDEV_EVDEV_INIT(_vtable, _session) ((idev_evdev){ \
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.element = IDEV_ELEMENT_INIT((_vtable), (_session)), \
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.fd = -1, \
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})
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#define IDEV_EVDEV_NAME_MAX (8 + DECIMAL_STR_MAX(unsigned) * 2)
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static const idev_element_vtable unmanaged_evdev_vtable;
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static const idev_element_vtable managed_evdev_vtable;
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static int idev_evdev_resume(idev_evdev *evdev, int dev_fd);
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static void idev_evdev_pause(idev_evdev *evdev, bool release);
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/*
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* Virtual Evdev Element
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* The virtual evdev element is the base class of all other evdev elements. It
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* uses libevdev to access the kernel evdev API. It supports asynchronous
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* access revocation, re-syncing if events got dropped and more.
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* This element cannot be used by itself. There must be a wrapper around it
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* which opens a file-descriptor and passes it to the virtual evdev element.
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*/
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static void idev_evdev_name(char *out, dev_t devnum) {
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/* @out must be at least of size IDEV_EVDEV_NAME_MAX */
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sprintf(out, "evdev/%u:%u", major(devnum), minor(devnum));
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}
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static int idev_evdev_feed_resync(idev_evdev *evdev) {
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idev_data data = {
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.type = IDEV_DATA_RESYNC,
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.resync = evdev->resync,
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};
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return idev_element_feed(&evdev->element, &data);
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}
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static int idev_evdev_feed_evdev(idev_evdev *evdev, struct input_event *event) {
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idev_data data = {
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.type = IDEV_DATA_EVDEV,
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.resync = evdev->resync,
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.evdev = {
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.event = *event,
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},
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};
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return idev_element_feed(&evdev->element, &data);
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}
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static void idev_evdev_hup(idev_evdev *evdev) {
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/*
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* On HUP, we close the current fd via idev_evdev_pause(). This drops
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* the event-sources from the main-loop and effectively puts the
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* element asleep. If the HUP is part of a hotplug-event, a following
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* udev-notification will destroy the element. Otherwise, the HUP is
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* either result of access-revokation or a serious error.
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* For unmanaged devices, we should never receive HUP (except for
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* unplug-events). But if we do, something went seriously wrong and we
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* shouldn't try to be clever.
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* Instead, we simply stay asleep and wait for the device to be
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* disabled and then re-enabled (or closed and re-opened). This will
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* re-open the device node and restart the device.
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* For managed devices, a HUP usually means our device-access was
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* revoked. In that case, we simply put the device asleep and wait for
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* logind to notify us once the device is alive again. logind also
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* passes us a new fd. Hence, we don't have to re-enable the device.
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*
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* Long story short: The only thing we have to do here, is close() the
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* file-descriptor and remove it from the main-loop. Everything else is
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* handled via additional events we receive.
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*/
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idev_evdev_pause(evdev, true);
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}
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static int idev_evdev_io(idev_evdev *evdev) {
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idev_element *e = &evdev->element;
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struct input_event ev;
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unsigned int flags;
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int r, error = 0;
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/*
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* Read input-events via libevdev until the input-queue is drained. In
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* case we're disabled, don't do anything. The input-queue might
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* overflow, but we don't care as we have to resync after wake-up,
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* anyway.
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* TODO: libevdev should give us a hint how many events to read. We
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* really want to avoid starvation, so we shouldn't read forever in
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* case we cannot keep up with the kernel.
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* TODO: Make sure libevdev always reports SYN_DROPPED to us, regardless
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* whether any event was synced afterwards.
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*/
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flags = LIBEVDEV_READ_FLAG_NORMAL;
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while (e->enabled) {
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if (evdev->unsync) {
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/* immediately resync, even if in sync right now */
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evdev->unsync = false;
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evdev->resync = false;
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flags = LIBEVDEV_READ_FLAG_NORMAL;
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r = libevdev_next_event(evdev->evdev, flags | LIBEVDEV_READ_FLAG_FORCE_SYNC, &ev);
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if (r < 0 && r != -EAGAIN) {
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r = 0;
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goto error;
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} else if (r != LIBEVDEV_READ_STATUS_SYNC) {
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log_debug("idev-evdev: %s/%s: cannot force resync: %d",
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e->session->name, e->name, r);
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}
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} else {
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r = libevdev_next_event(evdev->evdev, flags, &ev);
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}
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if (evdev->resync && r == -EAGAIN) {
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/* end of re-sync */
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evdev->resync = false;
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flags = LIBEVDEV_READ_FLAG_NORMAL;
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} else if (r == -EAGAIN) {
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/* no data available */
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break;
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} else if (r < 0) {
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/* read error */
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goto error;
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} else if (r == LIBEVDEV_READ_STATUS_SYNC) {
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if (evdev->resync) {
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/* sync-event */
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r = idev_evdev_feed_evdev(evdev, &ev);
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if (r != 0) {
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error = r;
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break;
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}
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} else {
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/* start of sync */
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evdev->resync = true;
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flags = LIBEVDEV_READ_FLAG_SYNC;
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r = idev_evdev_feed_resync(evdev);
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if (r != 0) {
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error = r;
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break;
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}
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}
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} else {
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/* normal event */
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r = idev_evdev_feed_evdev(evdev, &ev);
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if (r != 0) {
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error = r;
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break;
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}
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}
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}
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if (error < 0)
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log_debug_errno(error, "idev-evdev: %s/%s: error on data event: %m",
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e->session->name, e->name);
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return error;
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error:
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idev_evdev_hup(evdev);
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return 0; /* idev_evdev_hup() handles the error so discard it */
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}
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static int idev_evdev_event_fn(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
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idev_evdev *evdev = userdata;
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/* fetch data as long as EPOLLIN is signalled */
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if (revents & EPOLLIN)
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return idev_evdev_io(evdev);
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if (revents & (EPOLLHUP | EPOLLERR))
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idev_evdev_hup(evdev);
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return 0;
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}
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static int idev_evdev_idle_fn(sd_event_source *s, void *userdata) {
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idev_evdev *evdev = userdata;
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/*
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* The idle-event is raised whenever we have to re-sync the libevdev
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* state from the kernel. We simply call into idev_evdev_io() which
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* flushes the state and re-syncs it if @unsync is set.
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* State has to be synced whenever our view of the kernel device is
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* out of date. This is the case when we open the device, if the
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* kernel's receive buffer overflows, or on other exceptional
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* situations. Events during re-syncs must be forwarded to the upper
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* layers so they can update their view of the device. However, such
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* events must only be handled passively, as they might be out-of-order
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* and/or re-ordered. Therefore, we mark them as 'sync' events.
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*/
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if (!evdev->unsync)
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return 0;
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return idev_evdev_io(evdev);
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}
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static void idev_evdev_destroy(idev_evdev *evdev) {
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assert(evdev);
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assert(evdev->fd < 0);
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libevdev_free(evdev->evdev);
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evdev->evdev = NULL;
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}
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static void idev_evdev_enable(idev_evdev *evdev) {
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assert(evdev);
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assert(evdev->fd_src);
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assert(evdev->idle_src);
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if (evdev->running)
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return;
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if (evdev->fd < 0 || evdev->element.n_open < 1 || !evdev->element.enabled)
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return;
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evdev->running = true;
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sd_event_source_set_enabled(evdev->fd_src, SD_EVENT_ON);
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sd_event_source_set_enabled(evdev->idle_src, SD_EVENT_ONESHOT);
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}
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static void idev_evdev_disable(idev_evdev *evdev) {
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assert(evdev);
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assert(evdev->fd_src);
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assert(evdev->idle_src);
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if (!evdev->running)
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return;
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evdev->running = false;
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idev_evdev_feed_resync(evdev);
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sd_event_source_set_enabled(evdev->fd_src, SD_EVENT_OFF);
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sd_event_source_set_enabled(evdev->idle_src, SD_EVENT_OFF);
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}
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static int idev_evdev_resume(idev_evdev *evdev, int dev_fd) {
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idev_element *e = &evdev->element;
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_cleanup_close_ int fd = dev_fd;
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int r, flags;
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if (fd < 0 || evdev->fd == fd) {
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fd = -1;
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idev_evdev_enable(evdev);
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return 0;
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}
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idev_evdev_pause(evdev, true);
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log_debug("idev-evdev: %s/%s: resume", e->session->name, e->name);
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r = fd_nonblock(fd, true);
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if (r < 0)
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return r;
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r = fd_cloexec(fd, true);
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if (r < 0)
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return r;
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flags = fcntl(fd, F_GETFL, 0);
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if (flags < 0)
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return -errno;
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flags &= O_ACCMODE;
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if (flags == O_WRONLY)
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return -EACCES;
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evdev->element.readable = true;
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evdev->element.writable = !(flags & O_RDONLY);
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/*
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* TODO: We *MUST* re-sync the device so we get a delta of the changed
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* state while we didn't read events from the device. This works just
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* fine with libevdev_change_fd(), however, libevdev_new_from_fd() (or
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* libevdev_set_fd()) don't pass us events for the initial device
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* state. So even if we force a re-sync, we will not get the delta for
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* the initial device state.
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* We really need to fix libevdev to support that!
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*/
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if (evdev->evdev)
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r = libevdev_change_fd(evdev->evdev, fd);
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else
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r = libevdev_new_from_fd(fd, &evdev->evdev);
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if (r < 0)
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return r;
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r = sd_event_add_io(e->session->context->event,
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&evdev->fd_src,
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fd,
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EPOLLHUP | EPOLLERR | EPOLLIN,
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idev_evdev_event_fn,
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evdev);
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if (r < 0)
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return r;
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r = sd_event_add_defer(e->session->context->event,
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&evdev->idle_src,
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idev_evdev_idle_fn,
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evdev);
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if (r < 0) {
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evdev->fd_src = sd_event_source_unref(evdev->fd_src);
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return r;
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}
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sd_event_source_set_enabled(evdev->fd_src, SD_EVENT_OFF);
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sd_event_source_set_enabled(evdev->idle_src, SD_EVENT_OFF);
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evdev->unsync = true;
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evdev->fd = fd;
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fd = -1;
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idev_evdev_enable(evdev);
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return 0;
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}
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static void idev_evdev_pause(idev_evdev *evdev, bool release) {
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idev_element *e = &evdev->element;
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if (evdev->fd < 0)
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return;
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log_debug("idev-evdev: %s/%s: pause", e->session->name, e->name);
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idev_evdev_disable(evdev);
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if (release) {
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evdev->idle_src = sd_event_source_unref(evdev->idle_src);
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evdev->fd_src = sd_event_source_unref(evdev->fd_src);
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evdev->fd = safe_close(evdev->fd);
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}
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}
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/*
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* Unmanaged Evdev Element
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* The unmanaged evdev element opens the evdev node for a given input device
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* directly (/dev/input/eventX) and thus needs sufficient privileges. It opens
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* the device only if we really require it and releases it as soon as we're
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* disabled or closed.
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* The unmanaged element can be used in all situations where you have direct
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* access to input device nodes. Unlike managed evdev elements, it can be used
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* outside of user sessions and in emergency situations where logind is not
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* available.
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*/
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static void unmanaged_evdev_resume(idev_element *e) {
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unmanaged_evdev *eu = unmanaged_evdev_from_element(e);
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int r, fd;
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/*
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* Unmanaged devices can be acquired on-demand. Therefore, don't
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* acquire it unless someone opened the device *and* we're enabled.
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*/
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if (e->n_open < 1 || !e->enabled)
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return;
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fd = eu->evdev.fd;
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if (fd < 0) {
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fd = open(eu->devnode, O_RDWR | O_CLOEXEC | O_NOCTTY | O_NONBLOCK);
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if (fd < 0) {
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if (errno != EACCES && errno != EPERM) {
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log_debug_errno(errno, "idev-evdev: %s/%s: cannot open node %s: %m",
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e->session->name, e->name, eu->devnode);
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return;
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}
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fd = open(eu->devnode, O_RDONLY | O_CLOEXEC | O_NOCTTY | O_NONBLOCK);
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if (fd < 0) {
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log_debug_errno(errno, "idev-evdev: %s/%s: cannot open node %s: %m",
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e->session->name, e->name, eu->devnode);
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return;
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}
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e->readable = true;
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e->writable = false;
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} else {
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e->readable = true;
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e->writable = true;
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}
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}
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r = idev_evdev_resume(&eu->evdev, fd);
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if (r < 0)
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log_debug_errno(r, "idev-evdev: %s/%s: cannot resume: %m",
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e->session->name, e->name);
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}
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static void unmanaged_evdev_pause(idev_element *e) {
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unmanaged_evdev *eu = unmanaged_evdev_from_element(e);
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/*
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* Release the device if the device is disabled or there is no-one who
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* opened it. This guarantees we stay only available if we're opened
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* *and* enabled.
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*/
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idev_evdev_pause(&eu->evdev, true);
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}
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static int unmanaged_evdev_new(idev_element **out, idev_session *s, struct udev_device *ud) {
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_cleanup_(idev_element_freep) idev_element *e = NULL;
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char name[IDEV_EVDEV_NAME_MAX];
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unmanaged_evdev *eu;
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const char *devnode;
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dev_t devnum;
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int r;
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assert_return(s, -EINVAL);
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assert_return(ud, -EINVAL);
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devnode = udev_device_get_devnode(ud);
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devnum = udev_device_get_devnum(ud);
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if (!devnode || devnum == 0)
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return -ENODEV;
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idev_evdev_name(name, devnum);
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eu = new0(unmanaged_evdev, 1);
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if (!eu)
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return -ENOMEM;
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e = &eu->evdev.element;
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eu->evdev = IDEV_EVDEV_INIT(&unmanaged_evdev_vtable, s);
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eu->devnode = strdup(devnode);
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if (!eu->devnode)
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return -ENOMEM;
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|
r = idev_element_add(e, name);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
if (out)
|
|
*out = e;
|
|
e = NULL;
|
|
return 0;
|
|
}
|
|
|
|
static void unmanaged_evdev_free(idev_element *e) {
|
|
unmanaged_evdev *eu = unmanaged_evdev_from_element(e);
|
|
|
|
idev_evdev_destroy(&eu->evdev);
|
|
free(eu->devnode);
|
|
free(eu);
|
|
}
|
|
|
|
static const idev_element_vtable unmanaged_evdev_vtable = {
|
|
.free = unmanaged_evdev_free,
|
|
.enable = unmanaged_evdev_resume,
|
|
.disable = unmanaged_evdev_pause,
|
|
.open = unmanaged_evdev_resume,
|
|
.close = unmanaged_evdev_pause,
|
|
};
|
|
|
|
/*
|
|
* Managed Evdev Element
|
|
* The managed evdev element uses systemd-logind to acquire evdev devices. This
|
|
* means, we do not open the device node /dev/input/eventX directly. Instead,
|
|
* logind passes us a file-descriptor whenever our session is activated. Thus,
|
|
* we don't need access to the device node directly.
|
|
* Furthermore, whenever the session is put asleep, logind revokes the
|
|
* file-descriptor so we loose access to the device.
|
|
* Managed evdev elements should be preferred over unmanaged elements whenever
|
|
* you run inside a user session with exclusive device access.
|
|
*/
|
|
|
|
static int managed_evdev_take_device_fn(sd_bus_message *reply,
|
|
void *userdata,
|
|
sd_bus_error *ret_error) {
|
|
managed_evdev *em = userdata;
|
|
idev_element *e = &em->evdev.element;
|
|
idev_session *s = e->session;
|
|
int r, paused, fd;
|
|
|
|
em->slot_take_device = sd_bus_slot_unref(em->slot_take_device);
|
|
|
|
if (sd_bus_message_is_method_error(reply, NULL)) {
|
|
const sd_bus_error *error = sd_bus_message_get_error(reply);
|
|
|
|
log_debug("idev-evdev: %s/%s: TakeDevice failed: %s: %s",
|
|
s->name, e->name, error->name, error->message);
|
|
return 0;
|
|
}
|
|
|
|
em->acquired = true;
|
|
|
|
r = sd_bus_message_read(reply, "hb", &fd, &paused);
|
|
if (r < 0) {
|
|
log_debug("idev-evdev: %s/%s: erroneous TakeDevice reply", s->name, e->name);
|
|
return 0;
|
|
}
|
|
|
|
/* If the device is paused, ignore it; we will get the next fd via
|
|
* ResumeDevice signals. */
|
|
if (paused)
|
|
return 0;
|
|
|
|
fd = fcntl(fd, F_DUPFD_CLOEXEC, 3);
|
|
if (fd < 0) {
|
|
log_debug_errno(errno, "idev-evdev: %s/%s: cannot duplicate evdev fd: %m", s->name, e->name);
|
|
return 0;
|
|
}
|
|
|
|
r = idev_evdev_resume(&em->evdev, fd);
|
|
if (r < 0)
|
|
log_debug_errno(r, "idev-evdev: %s/%s: cannot resume: %m",
|
|
s->name, e->name);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void managed_evdev_enable(idev_element *e) {
|
|
_cleanup_bus_message_unref_ sd_bus_message *m = NULL;
|
|
managed_evdev *em = managed_evdev_from_element(e);
|
|
idev_session *s = e->session;
|
|
idev_context *c = s->context;
|
|
int r;
|
|
|
|
/*
|
|
* Acquiring managed devices is heavy, so do it only once we're
|
|
* enabled *and* opened by someone.
|
|
*/
|
|
if (e->n_open < 1 || !e->enabled)
|
|
return;
|
|
|
|
/* bail out if already pending */
|
|
if (em->requested)
|
|
return;
|
|
|
|
r = sd_bus_message_new_method_call(c->sysbus,
|
|
&m,
|
|
"org.freedesktop.login1",
|
|
s->path,
|
|
"org.freedesktop.login1.Session",
|
|
"TakeDevice");
|
|
if (r < 0)
|
|
goto error;
|
|
|
|
r = sd_bus_message_append(m, "uu", major(em->devnum), minor(em->devnum));
|
|
if (r < 0)
|
|
goto error;
|
|
|
|
r = sd_bus_call_async(c->sysbus,
|
|
&em->slot_take_device,
|
|
m,
|
|
managed_evdev_take_device_fn,
|
|
em,
|
|
0);
|
|
if (r < 0)
|
|
goto error;
|
|
|
|
em->requested = true;
|
|
return;
|
|
|
|
error:
|
|
log_debug_errno(r, "idev-evdev: %s/%s: cannot send TakeDevice request: %m",
|
|
s->name, e->name);
|
|
}
|
|
|
|
static void managed_evdev_disable(idev_element *e) {
|
|
_cleanup_bus_message_unref_ sd_bus_message *m = NULL;
|
|
managed_evdev *em = managed_evdev_from_element(e);
|
|
idev_session *s = e->session;
|
|
idev_context *c = s->context;
|
|
int r;
|
|
|
|
/*
|
|
* Releasing managed devices is heavy. Once acquired, we get
|
|
* notifications for sleep/wake-up events, so there's no reason to
|
|
* release it if disabled but opened. However, if a device is closed,
|
|
* we release it immediately as we don't care for sleep/wake-up events
|
|
* then (even if we're actually enabled).
|
|
*/
|
|
|
|
idev_evdev_pause(&em->evdev, false);
|
|
|
|
if (e->n_open > 0 || !em->requested)
|
|
return;
|
|
|
|
/*
|
|
* If TakeDevice() is pending or was successful, make sure to
|
|
* release the device again. We don't care for return-values,
|
|
* so send it without waiting or callbacks.
|
|
* If a failed TakeDevice() is pending, but someone else took
|
|
* the device on the same bus-connection, we might incorrectly
|
|
* release their device. This is an unlikely race, though.
|
|
* Furthermore, you really shouldn't have two users of the
|
|
* controller-API on the same session, on the same devices, *AND* on
|
|
* the same bus-connection. So we don't care for that race..
|
|
*/
|
|
|
|
idev_evdev_pause(&em->evdev, true);
|
|
em->requested = false;
|
|
|
|
if (!em->acquired && !em->slot_take_device)
|
|
return;
|
|
|
|
em->slot_take_device = sd_bus_slot_unref(em->slot_take_device);
|
|
em->acquired = false;
|
|
|
|
r = sd_bus_message_new_method_call(c->sysbus,
|
|
&m,
|
|
"org.freedesktop.login1",
|
|
s->path,
|
|
"org.freedesktop.login1.Session",
|
|
"ReleaseDevice");
|
|
if (r >= 0) {
|
|
r = sd_bus_message_append(m, "uu", major(em->devnum), minor(em->devnum));
|
|
if (r >= 0)
|
|
r = sd_bus_send(c->sysbus, m, NULL);
|
|
}
|
|
|
|
if (r < 0 && r != -ENOTCONN)
|
|
log_debug_errno(r, "idev-evdev: %s/%s: cannot send ReleaseDevice: %m",
|
|
s->name, e->name);
|
|
}
|
|
|
|
static void managed_evdev_resume(idev_element *e, int fd) {
|
|
managed_evdev *em = managed_evdev_from_element(e);
|
|
idev_session *s = e->session;
|
|
int r;
|
|
|
|
/*
|
|
* We get ResumeDevice signals whenever logind resumed a previously
|
|
* paused device. The arguments contain the major/minor number of the
|
|
* related device and a new file-descriptor for the freshly opened
|
|
* device-node. We take the file-descriptor and immediately resume the
|
|
* device.
|
|
*/
|
|
|
|
fd = fcntl(fd, F_DUPFD_CLOEXEC, 3);
|
|
if (fd < 0) {
|
|
log_debug_errno(errno, "idev-evdev: %s/%s: cannot duplicate evdev fd: %m",
|
|
s->name, e->name);
|
|
return;
|
|
}
|
|
|
|
r = idev_evdev_resume(&em->evdev, fd);
|
|
if (r < 0)
|
|
log_debug_errno(r, "idev-evdev: %s/%s: cannot resume: %m",
|
|
s->name, e->name);
|
|
|
|
return;
|
|
}
|
|
|
|
static void managed_evdev_pause(idev_element *e, const char *mode) {
|
|
managed_evdev *em = managed_evdev_from_element(e);
|
|
idev_session *s = e->session;
|
|
idev_context *c = s->context;
|
|
int r;
|
|
|
|
/*
|
|
* We get PauseDevice() signals from logind whenever a device we
|
|
* requested was, or is about to be, paused. Arguments are major/minor
|
|
* number of the device and the mode of the operation.
|
|
* We treat it as asynchronous access-revocation (as if we got HUP on
|
|
* the device fd). Note that we might have already treated the HUP
|
|
* event via EPOLLHUP, whichever comes first.
|
|
*
|
|
* @mode can be one of the following:
|
|
* "pause": The device is about to be paused. We must react
|
|
* immediately and respond with PauseDeviceComplete(). Once
|
|
* we replied, logind will pause the device. Note that
|
|
* logind might apply any kind of timeout and force pause
|
|
* the device if we don't respond in a timely manner. In
|
|
* this case, we will receive a second PauseDevice event
|
|
* with @mode set to "force" (or similar).
|
|
* "force": The device was disabled forecfully by logind. Access is
|
|
* already revoked. This is just an asynchronous
|
|
* notification so we can put the device asleep (in case
|
|
* we didn't already notice the access revocation).
|
|
* "gone": This is like "force" but is sent if the device was
|
|
* paused due to a device-removal event.
|
|
*
|
|
* We always handle PauseDevice signals as "force" as we properly
|
|
* support asynchronous access revocation, anyway. But in case logind
|
|
* sent mode "pause", we also call PauseDeviceComplete() to immediately
|
|
* acknowledge the request.
|
|
*/
|
|
|
|
idev_evdev_pause(&em->evdev, true);
|
|
|
|
if (streq(mode, "pause")) {
|
|
_cleanup_bus_message_unref_ sd_bus_message *m = NULL;
|
|
|
|
/*
|
|
* Sending PauseDeviceComplete() is racy if logind triggers the
|
|
* timeout. That is, if we take too long and logind pauses the
|
|
* device by sending a forced PauseDevice, our
|
|
* PauseDeviceComplete call will be stray. That's fine, though.
|
|
* logind ignores such stray calls. Only if logind also sent a
|
|
* further PauseDevice() signal, it might match our call
|
|
* incorrectly to the newer PauseDevice(). That's fine, too, as
|
|
* we handle that event asynchronously, anyway. Therefore,
|
|
* whatever happens, we're fine. Yay!
|
|
*/
|
|
|
|
r = sd_bus_message_new_method_call(c->sysbus,
|
|
&m,
|
|
"org.freedesktop.login1",
|
|
s->path,
|
|
"org.freedesktop.login1.Session",
|
|
"PauseDeviceComplete");
|
|
if (r >= 0) {
|
|
r = sd_bus_message_append(m, "uu", major(em->devnum), minor(em->devnum));
|
|
if (r >= 0)
|
|
r = sd_bus_send(c->sysbus, m, NULL);
|
|
}
|
|
|
|
if (r < 0)
|
|
log_debug_errno(r, "idev-evdev: %s/%s: cannot send PauseDeviceComplete: %m",
|
|
s->name, e->name);
|
|
}
|
|
}
|
|
|
|
static int managed_evdev_new(idev_element **out, idev_session *s, struct udev_device *ud) {
|
|
_cleanup_(idev_element_freep) idev_element *e = NULL;
|
|
char name[IDEV_EVDEV_NAME_MAX];
|
|
managed_evdev *em;
|
|
dev_t devnum;
|
|
int r;
|
|
|
|
assert_return(s, -EINVAL);
|
|
assert_return(s->managed, -EINVAL);
|
|
assert_return(s->context->sysbus, -EINVAL);
|
|
assert_return(ud, -EINVAL);
|
|
|
|
devnum = udev_device_get_devnum(ud);
|
|
if (devnum == 0)
|
|
return -ENODEV;
|
|
|
|
idev_evdev_name(name, devnum);
|
|
|
|
em = new0(managed_evdev, 1);
|
|
if (!em)
|
|
return -ENOMEM;
|
|
|
|
e = &em->evdev.element;
|
|
em->evdev = IDEV_EVDEV_INIT(&managed_evdev_vtable, s);
|
|
em->devnum = devnum;
|
|
|
|
r = idev_element_add(e, name);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
if (out)
|
|
*out = e;
|
|
e = NULL;
|
|
return 0;
|
|
}
|
|
|
|
static void managed_evdev_free(idev_element *e) {
|
|
managed_evdev *em = managed_evdev_from_element(e);
|
|
|
|
idev_evdev_destroy(&em->evdev);
|
|
free(em);
|
|
}
|
|
|
|
static const idev_element_vtable managed_evdev_vtable = {
|
|
.free = managed_evdev_free,
|
|
.enable = managed_evdev_enable,
|
|
.disable = managed_evdev_disable,
|
|
.open = managed_evdev_enable,
|
|
.close = managed_evdev_disable,
|
|
.resume = managed_evdev_resume,
|
|
.pause = managed_evdev_pause,
|
|
};
|
|
|
|
/*
|
|
* Generic Constructor
|
|
* Instead of relying on the caller to choose between managed and unmanaged
|
|
* evdev devices, the idev_evdev_new() constructor does that for you (by
|
|
* looking at s->managed).
|
|
*/
|
|
|
|
bool idev_is_evdev(idev_element *e) {
|
|
return e && (e->vtable == &unmanaged_evdev_vtable ||
|
|
e->vtable == &managed_evdev_vtable);
|
|
}
|
|
|
|
idev_element *idev_find_evdev(idev_session *s, dev_t devnum) {
|
|
char name[IDEV_EVDEV_NAME_MAX];
|
|
|
|
assert_return(s, NULL);
|
|
assert_return(devnum != 0, NULL);
|
|
|
|
idev_evdev_name(name, devnum);
|
|
return idev_find_element(s, name);
|
|
}
|
|
|
|
int idev_evdev_new(idev_element **out, idev_session *s, struct udev_device *ud) {
|
|
assert_return(s, -EINVAL);
|
|
assert_return(ud, -EINVAL);
|
|
|
|
return s->managed ? managed_evdev_new(out, s, ud) : unmanaged_evdev_new(out, s, ud);
|
|
}
|