+++ /dev/null
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
-/***
- This file is part of systemd.
-
- Copyright (C) 2014 David Herrmann <dh.herrmann@gmail.com>
-
- 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 <fcntl.h>
-#include <libevdev/libevdev.h>
-#include <libudev.h>
-#include <stdbool.h>
-#include <stdlib.h>
-#include <systemd/sd-bus.h>
-#include <systemd/sd-event.h>
-#include "bus-util.h"
-#include "idev.h"
-#include "idev-internal.h"
-#include "macro.h"
-#include "util.h"
-
-typedef struct idev_evdev idev_evdev;
-typedef struct unmanaged_evdev unmanaged_evdev;
-typedef struct managed_evdev managed_evdev;
-
-struct idev_evdev {
- idev_element element;
- struct libevdev *evdev;
- int fd;
- sd_event_source *fd_src;
- sd_event_source *idle_src;
-
- bool unsync : 1; /* not in-sync with kernel */
- bool resync : 1; /* re-syncing with kernel */
- bool running : 1;
-};
-
-struct unmanaged_evdev {
- idev_evdev evdev;
- char *devnode;
-};
-
-struct managed_evdev {
- idev_evdev evdev;
- dev_t devnum;
- sd_bus_slot *slot_take_device;
-
- bool requested : 1; /* TakeDevice() was sent */
- bool acquired : 1; /* TakeDevice() was successful */
-};
-
-#define idev_evdev_from_element(_e) container_of((_e), idev_evdev, element)
-#define unmanaged_evdev_from_element(_e) \
- container_of(idev_evdev_from_element(_e), unmanaged_evdev, evdev)
-#define managed_evdev_from_element(_e) \
- container_of(idev_evdev_from_element(_e), managed_evdev, evdev)
-
-#define IDEV_EVDEV_INIT(_vtable, _session) ((idev_evdev){ \
- .element = IDEV_ELEMENT_INIT((_vtable), (_session)), \
- .fd = -1, \
- })
-
-#define IDEV_EVDEV_NAME_MAX (8 + DECIMAL_STR_MAX(unsigned) * 2)
-
-static const idev_element_vtable unmanaged_evdev_vtable;
-static const idev_element_vtable managed_evdev_vtable;
-
-static int idev_evdev_resume(idev_evdev *evdev, int dev_fd);
-static void idev_evdev_pause(idev_evdev *evdev, bool release);
-
-/*
- * Virtual Evdev Element
- * The virtual evdev element is the base class of all other evdev elements. It
- * uses libevdev to access the kernel evdev API. It supports asynchronous
- * access revocation, re-syncing if events got dropped and more.
- * This element cannot be used by itself. There must be a wrapper around it
- * which opens a file-descriptor and passes it to the virtual evdev element.
- */
-
-static void idev_evdev_name(char *out, dev_t devnum) {
- /* @out must be at least of size IDEV_EVDEV_NAME_MAX */
- sprintf(out, "evdev/%u:%u", major(devnum), minor(devnum));
-}
-
-static int idev_evdev_feed_resync(idev_evdev *evdev) {
- idev_data data = {
- .type = IDEV_DATA_RESYNC,
- .resync = evdev->resync,
- };
-
- return idev_element_feed(&evdev->element, &data);
-}
-
-static int idev_evdev_feed_evdev(idev_evdev *evdev, struct input_event *event) {
- idev_data data = {
- .type = IDEV_DATA_EVDEV,
- .resync = evdev->resync,
- .evdev = {
- .event = *event,
- },
- };
-
- return idev_element_feed(&evdev->element, &data);
-}
-
-static void idev_evdev_hup(idev_evdev *evdev) {
- /*
- * On HUP, we close the current fd via idev_evdev_pause(). This drops
- * the event-sources from the main-loop and effectively puts the
- * element asleep. If the HUP is part of a hotplug-event, a following
- * udev-notification will destroy the element. Otherwise, the HUP is
- * either result of access-revokation or a serious error.
- * For unmanaged devices, we should never receive HUP (except for
- * unplug-events). But if we do, something went seriously wrong and we
- * shouldn't try to be clever.
- * Instead, we simply stay asleep and wait for the device to be
- * disabled and then re-enabled (or closed and re-opened). This will
- * re-open the device node and restart the device.
- * For managed devices, a HUP usually means our device-access was
- * revoked. In that case, we simply put the device asleep and wait for
- * logind to notify us once the device is alive again. logind also
- * passes us a new fd. Hence, we don't have to re-enable the device.
- *
- * Long story short: The only thing we have to do here, is close() the
- * file-descriptor and remove it from the main-loop. Everything else is
- * handled via additional events we receive.
- */
-
- idev_evdev_pause(evdev, true);
-}
-
-static int idev_evdev_io(idev_evdev *evdev) {
- idev_element *e = &evdev->element;
- struct input_event ev;
- unsigned int flags;
- int r, error = 0;
-
- /*
- * Read input-events via libevdev until the input-queue is drained. In
- * case we're disabled, don't do anything. The input-queue might
- * overflow, but we don't care as we have to resync after wake-up,
- * anyway.
- * TODO: libevdev should give us a hint how many events to read. We
- * really want to avoid starvation, so we shouldn't read forever in
- * case we cannot keep up with the kernel.
- * TODO: Make sure libevdev always reports SYN_DROPPED to us, regardless
- * whether any event was synced afterwards.
- */
-
- flags = LIBEVDEV_READ_FLAG_NORMAL;
- while (e->enabled) {
- if (evdev->unsync) {
- /* immediately resync, even if in sync right now */
- evdev->unsync = false;
- evdev->resync = false;
- flags = LIBEVDEV_READ_FLAG_NORMAL;
- r = libevdev_next_event(evdev->evdev, flags | LIBEVDEV_READ_FLAG_FORCE_SYNC, &ev);
- if (r < 0 && r != -EAGAIN) {
- r = 0;
- goto error;
- } else if (r != LIBEVDEV_READ_STATUS_SYNC) {
- log_debug("idev-evdev: %s/%s: cannot force resync: %d",
- e->session->name, e->name, r);
- }
- } else {
- r = libevdev_next_event(evdev->evdev, flags, &ev);
- }
-
- if (evdev->resync && r == -EAGAIN) {
- /* end of re-sync */
- evdev->resync = false;
- flags = LIBEVDEV_READ_FLAG_NORMAL;
- } else if (r == -EAGAIN) {
- /* no data available */
- break;
- } else if (r < 0) {
- /* read error */
- goto error;
- } else if (r == LIBEVDEV_READ_STATUS_SYNC) {
- if (evdev->resync) {
- /* sync-event */
- r = idev_evdev_feed_evdev(evdev, &ev);
- if (r != 0) {
- error = r;
- break;
- }
- } else {
- /* start of sync */
- evdev->resync = true;
- flags = LIBEVDEV_READ_FLAG_SYNC;
- r = idev_evdev_feed_resync(evdev);
- if (r != 0) {
- error = r;
- break;
- }
- }
- } else {
- /* normal event */
- r = idev_evdev_feed_evdev(evdev, &ev);
- if (r != 0) {
- error = r;
- break;
- }
- }
- }
-
- if (error < 0)
- log_debug_errno(error, "idev-evdev: %s/%s: error on data event: %m",
- e->session->name, e->name);
- return error;
-
-error:
- idev_evdev_hup(evdev);
- return 0; /* idev_evdev_hup() handles the error so discard it */
-}
-
-static int idev_evdev_event_fn(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
- idev_evdev *evdev = userdata;
-
- /* fetch data as long as EPOLLIN is signalled */
- if (revents & EPOLLIN)
- return idev_evdev_io(evdev);
-
- if (revents & (EPOLLHUP | EPOLLERR))
- idev_evdev_hup(evdev);
-
- return 0;
-}
-
-static int idev_evdev_idle_fn(sd_event_source *s, void *userdata) {
- idev_evdev *evdev = userdata;
-
- /*
- * The idle-event is raised whenever we have to re-sync the libevdev
- * state from the kernel. We simply call into idev_evdev_io() which
- * flushes the state and re-syncs it if @unsync is set.
- * State has to be synced whenever our view of the kernel device is
- * out of date. This is the case when we open the device, if the
- * kernel's receive buffer overflows, or on other exceptional
- * situations. Events during re-syncs must be forwarded to the upper
- * layers so they can update their view of the device. However, such
- * events must only be handled passively, as they might be out-of-order
- * and/or re-ordered. Therefore, we mark them as 'sync' events.
- */
-
- if (!evdev->unsync)
- return 0;
-
- return idev_evdev_io(evdev);
-}
-
-static void idev_evdev_destroy(idev_evdev *evdev) {
- assert(evdev);
- assert(evdev->fd < 0);
-
- libevdev_free(evdev->evdev);
- evdev->evdev = NULL;
-}
-
-static void idev_evdev_enable(idev_evdev *evdev) {
- assert(evdev);
- assert(evdev->fd_src);
- assert(evdev->idle_src);
-
- if (evdev->running)
- return;
- if (evdev->fd < 0 || evdev->element.n_open < 1 || !evdev->element.enabled)
- return;
-
- evdev->running = true;
- sd_event_source_set_enabled(evdev->fd_src, SD_EVENT_ON);
- sd_event_source_set_enabled(evdev->idle_src, SD_EVENT_ONESHOT);
-}
-
-static void idev_evdev_disable(idev_evdev *evdev) {
- assert(evdev);
- assert(evdev->fd_src);
- assert(evdev->idle_src);
-
- if (!evdev->running)
- return;
-
- evdev->running = false;
- idev_evdev_feed_resync(evdev);
- sd_event_source_set_enabled(evdev->fd_src, SD_EVENT_OFF);
- sd_event_source_set_enabled(evdev->idle_src, SD_EVENT_OFF);
-}
-
-static int idev_evdev_resume(idev_evdev *evdev, int dev_fd) {
- idev_element *e = &evdev->element;
- _cleanup_close_ int fd = dev_fd;
- int r, flags;
-
- if (fd < 0 || evdev->fd == fd) {
- fd = -1;
- idev_evdev_enable(evdev);
- return 0;
- }
-
- idev_evdev_pause(evdev, true);
- log_debug("idev-evdev: %s/%s: resume", e->session->name, e->name);
-
- r = fd_nonblock(fd, true);
- if (r < 0)
- return r;
-
- r = fd_cloexec(fd, true);
- if (r < 0)
- return r;
-
- flags = fcntl(fd, F_GETFL, 0);
- if (flags < 0)
- return -errno;
-
- flags &= O_ACCMODE;
- if (flags == O_WRONLY)
- return -EACCES;
-
- evdev->element.readable = true;
- evdev->element.writable = !(flags & O_RDONLY);
-
- /*
- * TODO: We *MUST* re-sync the device so we get a delta of the changed
- * state while we didn't read events from the device. This works just
- * fine with libevdev_change_fd(), however, libevdev_new_from_fd() (or
- * libevdev_set_fd()) don't pass us events for the initial device
- * state. So even if we force a re-sync, we will not get the delta for
- * the initial device state.
- * We really need to fix libevdev to support that!
- */
- if (evdev->evdev)
- r = libevdev_change_fd(evdev->evdev, fd);
- else
- r = libevdev_new_from_fd(fd, &evdev->evdev);
-
- if (r < 0)
- return r;
-
- r = sd_event_add_io(e->session->context->event,
- &evdev->fd_src,
- fd,
- EPOLLHUP | EPOLLERR | EPOLLIN,
- idev_evdev_event_fn,
- evdev);
- if (r < 0)
- return r;
-
- r = sd_event_add_defer(e->session->context->event,
- &evdev->idle_src,
- idev_evdev_idle_fn,
- evdev);
- if (r < 0) {
- evdev->fd_src = sd_event_source_unref(evdev->fd_src);
- return r;
- }
-
- sd_event_source_set_enabled(evdev->fd_src, SD_EVENT_OFF);
- sd_event_source_set_enabled(evdev->idle_src, SD_EVENT_OFF);
-
- evdev->unsync = true;
- evdev->fd = fd;
- fd = -1;
-
- idev_evdev_enable(evdev);
- return 0;
-}
-
-static void idev_evdev_pause(idev_evdev *evdev, bool release) {
- idev_element *e = &evdev->element;
-
- if (evdev->fd < 0)
- return;
-
- log_debug("idev-evdev: %s/%s: pause", e->session->name, e->name);
-
- idev_evdev_disable(evdev);
- if (release) {
- evdev->idle_src = sd_event_source_unref(evdev->idle_src);
- evdev->fd_src = sd_event_source_unref(evdev->fd_src);
- evdev->fd = safe_close(evdev->fd);
- }
-}
-
-/*
- * Unmanaged Evdev Element
- * The unmanaged evdev element opens the evdev node for a given input device
- * directly (/dev/input/eventX) and thus needs sufficient privileges. It opens
- * the device only if we really require it and releases it as soon as we're
- * disabled or closed.
- * The unmanaged element can be used in all situations where you have direct
- * access to input device nodes. Unlike managed evdev elements, it can be used
- * outside of user sessions and in emergency situations where logind is not
- * available.
- */
-
-static void unmanaged_evdev_resume(idev_element *e) {
- unmanaged_evdev *eu = unmanaged_evdev_from_element(e);
- int r, fd;
-
- /*
- * Unmanaged devices can be acquired on-demand. Therefore, don't
- * acquire it unless someone opened the device *and* we're enabled.
- */
- if (e->n_open < 1 || !e->enabled)
- return;
-
- fd = eu->evdev.fd;
- if (fd < 0) {
- fd = open(eu->devnode, O_RDWR | O_CLOEXEC | O_NOCTTY | O_NONBLOCK);
- if (fd < 0) {
- if (errno != EACCES && errno != EPERM) {
- log_debug_errno(errno, "idev-evdev: %s/%s: cannot open node %s: %m",
- e->session->name, e->name, eu->devnode);
- return;
- }
-
- fd = open(eu->devnode, O_RDONLY | O_CLOEXEC | O_NOCTTY | O_NONBLOCK);
- if (fd < 0) {
- log_debug_errno(errno, "idev-evdev: %s/%s: cannot open node %s: %m",
- e->session->name, e->name, eu->devnode);
- return;
- }
-
- e->readable = true;
- e->writable = false;
- } else {
- e->readable = true;
- e->writable = true;
- }
- }
-
- r = idev_evdev_resume(&eu->evdev, fd);
- if (r < 0)
- log_debug_errno(r, "idev-evdev: %s/%s: cannot resume: %m",
- e->session->name, e->name);
-}
-
-static void unmanaged_evdev_pause(idev_element *e) {
- unmanaged_evdev *eu = unmanaged_evdev_from_element(e);
-
- /*
- * Release the device if the device is disabled or there is no-one who
- * opened it. This guarantees we stay only available if we're opened
- * *and* enabled.
- */
-
- idev_evdev_pause(&eu->evdev, true);
-}
-
-static int unmanaged_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];
- unmanaged_evdev *eu;
- const char *devnode;
- dev_t devnum;
- int r;
-
- assert_return(s, -EINVAL);
- assert_return(ud, -EINVAL);
-
- devnode = udev_device_get_devnode(ud);
- devnum = udev_device_get_devnum(ud);
- if (!devnode || devnum == 0)
- return -ENODEV;
-
- idev_evdev_name(name, devnum);
-
- eu = new0(unmanaged_evdev, 1);
- if (!eu)
- return -ENOMEM;
-
- e = &eu->evdev.element;
- eu->evdev = IDEV_EVDEV_INIT(&unmanaged_evdev_vtable, s);
-
- eu->devnode = strdup(devnode);
- if (!eu->devnode)
- return -ENOMEM;
-
- 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 *bus,
- 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);
-}
~ianmdlvl / elogind.git / blobdiff