From 7ed3a638b2e4ffb5e76a0cf1a008e1c7233edb75 Mon Sep 17 00:00:00 2001
From: David Herrmann <dh.herrmann@gmail.com>
Date: Tue, 26 Aug 2014 15:03:41 +0200
Subject: [PATCH] terminal: add system view interface
We're going to need multiple binaries that provide session-services via
logind device management. To avoid re-writing the seat/session/device
scan/monitor interface for each of them, this commit adds a generic helper
to libsystemd-terminal:
The sysview interface scans and tracks seats, sessions and devices on a
system. It basically mirrors the state of logind on the application side.
Now, each session-service can listen for matching sessions and
attach to them. On each session, managed device access is provided. This
way, it is pretty simple to write session-services that attach to multiple
sessions (even split across seats).
---
Makefile.am | 4 +
src/libsystemd-terminal/sysview-internal.h | 140 +++
src/libsystemd-terminal/sysview.c | 1471 ++++++++++++++++++++++++++++
src/libsystemd-terminal/sysview.h | 151 +++
4 files changed, 1766 insertions(+)
create mode 100644 src/libsystemd-terminal/sysview-internal.h
create mode 100644 src/libsystemd-terminal/sysview.c
create mode 100644 src/libsystemd-terminal/sysview.h
diff --git a/Makefile.am b/Makefile.am
index 70faed4acb..3a263f8c17 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -2971,6 +2971,9 @@ libsystemd_terminal_la_CFLAGS = \
$(AM_CFLAGS)
libsystemd_terminal_la_SOURCES = \
+ src/libsystemd-terminal/sysview.h \
+ src/libsystemd-terminal/sysview-internal.h \
+ src/libsystemd-terminal/sysview.c \
src/libsystemd-terminal/term-internal.h \
src/libsystemd-terminal/term-charset.c \
src/libsystemd-terminal/term-page.c \
@@ -2981,6 +2984,7 @@ libsystemd_terminal_la_SOURCES = \
src/libsystemd-terminal/unifont.c
libsystemd_terminal_la_LIBADD = \
+ libudev-internal.la \
libsystemd-internal.la \
libsystemd-shared.la
diff --git a/src/libsystemd-terminal/sysview-internal.h b/src/libsystemd-terminal/sysview-internal.h
new file mode 100644
index 0000000000..5aee9f67d8
--- /dev/null
+++ b/src/libsystemd-terminal/sysview-internal.h
@@ -0,0 +1,140 @@
+/*-*- 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/>.
+***/
+
+#pragma once
+
+#include <inttypes.h>
+#include <libudev.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <systemd/sd-bus.h>
+#include <systemd/sd-event.h>
+#include "hashmap.h"
+#include "list.h"
+#include "macro.h"
+#include "sysview.h"
+#include "util.h"
+
+/*
+ * Devices
+ */
+
+struct sysview_device {
+ sysview_seat *seat;
+ const char *name;
+ unsigned int type;
+
+ union {
+ struct {
+ struct udev_device *ud;
+ } evdev, drm;
+ };
+};
+
+sysview_device *sysview_find_device(sysview_context *c, const char *name);
+
+int sysview_device_new(sysview_device **out, sysview_seat *seat, const char *name);
+sysview_device *sysview_device_free(sysview_device *device);
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(sysview_device*, sysview_device_free);
+
+/*
+ * Sessions
+ */
+
+struct sysview_session {
+ sysview_seat *seat;
+ char *name;
+ char *path;
+
+ sd_bus_slot *slot_take_control;
+
+ bool custom : 1;
+ bool public : 1;
+ bool wants_control : 1;
+ bool has_control : 1;
+};
+
+sysview_session *sysview_find_session(sysview_context *c, const char *name);
+
+int sysview_session_new(sysview_session **out, sysview_seat *seat, const char *name);
+sysview_session *sysview_session_free(sysview_session *session);
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(sysview_session*, sysview_session_free);
+
+/*
+ * Seats
+ */
+
+struct sysview_seat {
+ sysview_context *context;
+ char *name;
+
+ Hashmap *session_map;
+ Hashmap *device_map;
+
+ bool scanned : 1;
+ bool public : 1;
+};
+
+sysview_seat *sysview_find_seat(sysview_context *c, const char *name);
+
+int sysview_seat_new(sysview_seat **out, sysview_context *c, const char *name);
+sysview_seat *sysview_seat_free(sysview_seat *seat);
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(sysview_seat*, sysview_seat_free);
+
+/*
+ * Contexts
+ */
+
+struct sysview_context {
+ sd_event *event;
+ sd_bus *sysbus;
+ struct udev *ud;
+ uint64_t custom_sid;
+
+ Hashmap *seat_map;
+ Hashmap *session_map;
+ Hashmap *device_map;
+
+ sd_event_source *scan_src;
+ sysview_event_fn event_fn;
+ void *userdata;
+
+ /* udev scanner */
+ struct udev_monitor *ud_monitor;
+ sd_event_source *ud_monitor_src;
+
+ /* logind scanner */
+ sd_bus_slot *ld_slot_manager_signal;
+ sd_bus_slot *ld_slot_list_seats;
+ sd_bus_slot *ld_slot_list_sessions;
+
+ bool scan_logind : 1;
+ bool scan_evdev : 1;
+ bool scan_drm : 1;
+ bool running : 1;
+ bool scanned : 1;
+ bool rescan : 1;
+};
+
+int sysview_context_rescan(sysview_context *c);
diff --git a/src/libsystemd-terminal/sysview.c b/src/libsystemd-terminal/sysview.c
new file mode 100644
index 0000000000..d885cb4d4a
--- /dev/null
+++ b/src/libsystemd-terminal/sysview.c
@@ -0,0 +1,1471 @@
+/*-*- 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 <inttypes.h>
+#include <libudev.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <systemd/sd-bus.h>
+#include <systemd/sd-event.h>
+#include <systemd/sd-login.h>
+#include "bus-util.h"
+#include "event-util.h"
+#include "macro.h"
+#include "set.h"
+#include "sysview.h"
+#include "sysview-internal.h"
+#include "udev-util.h"
+#include "util.h"
+
+static int context_raise_session_control(sysview_context *c, sysview_session *session, int error);
+
+/*
+ * Devices
+ */
+
+sysview_device *sysview_find_device(sysview_context *c, const char *name) {
+ assert_return(c, NULL);
+ assert_return(name, NULL);
+
+ return hashmap_get(c->device_map, name);
+}
+
+int sysview_device_new(sysview_device **out, sysview_seat *seat, const char *name) {
+ _cleanup_(sysview_device_freep) sysview_device *device = NULL;
+ int r;
+
+ assert_return(seat, -EINVAL);
+ assert_return(name, -EINVAL);
+
+ device = new0(sysview_device, 1);
+ if (!device)
+ return -ENOMEM;
+
+ device->seat = seat;
+ device->type = (unsigned)-1;
+
+ device->name = strdup(name);
+ if (!device->name)
+ return -ENOMEM;
+
+ r = hashmap_put(seat->context->device_map, device->name, device);
+ if (r < 0)
+ return r;
+
+ r = hashmap_put(seat->device_map, device->name, device);
+ if (r < 0)
+ return r;
+
+ if (out)
+ *out = device;
+ device = NULL;
+ return 0;
+}
+
+sysview_device *sysview_device_free(sysview_device *device) {
+ if (!device)
+ return NULL;
+
+ if (device->name) {
+ hashmap_remove_value(device->seat->device_map, device->name, device);
+ hashmap_remove_value(device->seat->context->device_map, device->name, device);
+ }
+
+ switch (device->type) {
+ case SYSVIEW_DEVICE_EVDEV:
+ device->evdev.ud = udev_device_unref(device->evdev.ud);
+ break;
+ case SYSVIEW_DEVICE_DRM:
+ device->drm.ud = udev_device_unref(device->drm.ud);
+ break;
+ }
+
+ free(device);
+
+ return NULL;
+}
+
+unsigned int sysview_device_get_type(sysview_device *device) {
+ assert_return(device, (unsigned)-1);
+
+ return device->type;
+}
+
+struct udev_device *sysview_device_get_ud(sysview_device *device) {
+ assert_return(device, NULL);
+
+ switch (device->type) {
+ case SYSVIEW_DEVICE_EVDEV:
+ return device->evdev.ud;
+ case SYSVIEW_DEVICE_DRM:
+ return device->drm.ud;
+ default:
+ assert_return(0, NULL);
+ }
+}
+
+static int device_new_ud(sysview_device **out, sysview_seat *seat, unsigned int type, struct udev_device *ud) {
+ _cleanup_(sysview_device_freep) sysview_device *device = NULL;
+ int r;
+
+ assert_return(seat, -EINVAL);
+ assert_return(ud, -EINVAL);
+
+ r = sysview_device_new(&device, seat, udev_device_get_syspath(ud));
+ if (r < 0)
+ return r;
+
+ device->type = type;
+
+ switch (type) {
+ case SYSVIEW_DEVICE_EVDEV:
+ device->evdev.ud = udev_device_ref(ud);
+ break;
+ case SYSVIEW_DEVICE_DRM:
+ device->drm.ud = udev_device_ref(ud);
+ break;
+ default:
+ assert_not_reached("sysview: invalid udev-device type");
+ }
+
+ if (out)
+ *out = device;
+ device = NULL;
+ return 0;
+}
+
+/*
+ * Sessions
+ */
+
+sysview_session *sysview_find_session(sysview_context *c, const char *name) {
+ assert_return(c, NULL);
+ assert_return(name, NULL);
+
+ return hashmap_get(c->session_map, name);
+}
+
+int sysview_session_new(sysview_session **out, sysview_seat *seat, const char *name) {
+ _cleanup_(sysview_session_freep) sysview_session *session = NULL;
+ int r;
+
+ assert_return(seat, -EINVAL);
+
+ session = new0(sysview_session, 1);
+ if (!session)
+ return -ENOMEM;
+
+ session->seat = seat;
+
+ if (name) {
+ /*
+ * If a name is given, we require it to be a logind session
+ * name. The session will be put in managed mode and we use
+ * logind to request controller access.
+ */
+
+ session->name = strdup(name);
+ if (!session->name)
+ return -ENOMEM;
+
+ r = sd_bus_path_encode("/org/freedesktop/login1/session",
+ session->name, &session->path);
+ if (r < 0)
+ return r;
+
+ session->custom = false;;
+ } else {
+ /*
+ * No session name was given. We assume this is an unmanaged
+ * session controlled by the application. We don't use logind
+ * at all and leave session management to the application. The
+ * name of the session-object is set to a unique random string
+ * that does not clash with the logind namespace.
+ */
+
+ r = asprintf(&session->name, "@custom%" PRIu64,
+ ++seat->context->custom_sid);
+ if (r < 0)
+ return -ENOMEM;
+
+ session->custom = true;
+ }
+
+ r = hashmap_put(seat->context->session_map, session->name, session);
+ if (r < 0)
+ return r;
+
+ r = hashmap_put(seat->session_map, session->name, session);
+ if (r < 0)
+ return r;
+
+ if (out)
+ *out = session;
+ session = NULL;
+ return 0;
+}
+
+sysview_session *sysview_session_free(sysview_session *session) {
+ if (!session)
+ return NULL;
+
+ assert(!session->public);
+ assert(!session->wants_control);
+
+ if (session->name) {
+ hashmap_remove_value(session->seat->session_map, session->name, session);
+ hashmap_remove_value(session->seat->context->session_map, session->name, session);
+ }
+
+ free(session->path);
+ free(session->name);
+ free(session);
+
+ return NULL;
+}
+
+const char *sysview_session_get_name(sysview_session *session) {
+ assert_return(session, NULL);
+
+ return session->name;
+}
+
+static int session_take_control_fn(sd_bus *bus,
+ sd_bus_message *reply,
+ void *userdata,
+ sd_bus_error *ret_error) {
+ sysview_session *session = userdata;
+ int error;
+
+ session->slot_take_control = sd_bus_slot_unref(session->slot_take_control);
+
+ if (sd_bus_message_is_method_error(reply, NULL)) {
+ const sd_bus_error *e = sd_bus_message_get_error(reply);
+
+ log_debug("sysview: %s: TakeControl failed: %s: %s",
+ session->name, e->name, e->message);
+ error = sd_bus_error_get_errno(e);
+ } else {
+ session->has_control = true;
+ error = 0;
+ }
+
+ return context_raise_session_control(session->seat->context, session, error);
+}
+
+int sysview_session_take_control(sysview_session *session) {
+ _cleanup_bus_message_unref_ sd_bus_message *m = NULL;
+ int r;
+
+ assert_return(session, -EINVAL);
+ assert_return(!session->custom, -EINVAL);
+
+ if (session->wants_control)
+ return 0;
+
+ r = sd_bus_message_new_method_call(session->seat->context->sysbus,
+ &m,
+ "org.freedesktop.login1",
+ session->path,
+ "org.freedesktop.login1.Session",
+ "TakeControl");
+ if (r < 0)
+ return r;
+
+ r = sd_bus_message_append(m, "b", 0);
+ if (r < 0)
+ return r;
+
+ r = sd_bus_call_async(session->seat->context->sysbus,
+ &session->slot_take_control,
+ m,
+ session_take_control_fn,
+ session,
+ 0);
+ if (r < 0)
+ return r;
+
+ session->wants_control = true;
+ return 0;
+}
+
+void sysview_session_release_control(sysview_session *session) {
+ _cleanup_bus_message_unref_ sd_bus_message *m = NULL;
+ int r;
+
+ assert(session);
+ assert(!session->custom);
+
+ if (!session->wants_control)
+ return;
+
+ session->wants_control = false;
+
+ if (!session->has_control && !session->slot_take_control)
+ return;
+
+ session->has_control = false;
+ session->slot_take_control = sd_bus_slot_unref(session->slot_take_control);
+
+ r = sd_bus_message_new_method_call(session->seat->context->sysbus,
+ &m,
+ "org.freedesktop.login1",
+ session->path,
+ "org.freedesktop.login1.Session",
+ "ReleaseControl");
+ if (r >= 0)
+ r = sd_bus_send(session->seat->context->sysbus, m, NULL);
+
+ if (r < 0 && r != -ENOTCONN)
+ log_debug("sysview: %s: cannot send ReleaseControl: %s",
+ session->name, strerror(-r));
+}
+
+/*
+ * Seats
+ */
+
+sysview_seat *sysview_find_seat(sysview_context *c, const char *name) {
+ assert_return(c, NULL);
+ assert_return(name, NULL);
+
+ return hashmap_get(c->seat_map, name);
+}
+
+int sysview_seat_new(sysview_seat **out, sysview_context *c, const char *name) {
+ _cleanup_(sysview_seat_freep) sysview_seat *seat = NULL;
+ int r;
+
+ assert_return(c, -EINVAL);
+ assert_return(name, -EINVAL);
+
+ seat = new0(sysview_seat, 1);
+ if (!seat)
+ return -ENOMEM;
+
+ seat->context = c;
+
+ seat->name = strdup(name);
+ if (!seat->name)
+ return -ENOMEM;
+
+ seat->session_map = hashmap_new(string_hash_func, string_compare_func);
+ if (!seat->session_map)
+ return -ENOMEM;
+
+ seat->device_map = hashmap_new(string_hash_func, string_compare_func);
+ if (!seat->device_map)
+ return -ENOMEM;
+
+ r = hashmap_put(c->seat_map, seat->name, seat);
+ if (r < 0)
+ return r;
+
+ if (out)
+ *out = seat;
+ seat = NULL;
+ return 0;
+}
+
+sysview_seat *sysview_seat_free(sysview_seat *seat) {
+ if (!seat)
+ return NULL;
+
+ assert(!seat->public);
+ assert(hashmap_size(seat->device_map) == 0);
+ assert(hashmap_size(seat->session_map) == 0);
+
+ if (seat->name)
+ hashmap_remove_value(seat->context->seat_map, seat->name, seat);
+
+ hashmap_free(seat->device_map);
+ hashmap_free(seat->session_map);
+ free(seat->name);
+ free(seat);
+
+ return NULL;
+}
+
+const char *sysview_seat_get_name(sysview_seat *seat) {
+ assert_return(seat, NULL);
+
+ return seat->name;
+}
+
+/*
+ * Contexts
+ */
+
+static int context_raise(sysview_context *c, sysview_event *event, int def) {
+ return c->running ? c->event_fn(c, c->userdata, event) : def;
+}
+
+static int context_raise_seat_add(sysview_context *c, sysview_seat *seat) {
+ sysview_event event = {
+ .type = SYSVIEW_EVENT_SEAT_ADD,
+ .seat_add = {
+ .seat = seat,
+ }
+ };
+
+ return context_raise(c, &event, 0);
+}
+
+static int context_raise_seat_remove(sysview_context *c, sysview_seat *seat) {
+ sysview_event event = {
+ .type = SYSVIEW_EVENT_SEAT_REMOVE,
+ .seat_remove = {
+ .seat = seat,
+ }
+ };
+
+ return context_raise(c, &event, 0);
+}
+
+static int context_raise_session_filter(sysview_context *c,
+ const char *id,
+ const char *seatid,
+ const char *username,
+ unsigned int uid) {
+ sysview_event event = {
+ .type = SYSVIEW_EVENT_SESSION_FILTER,
+ .session_filter = {
+ .id = id,
+ .seatid = seatid,
+ .username = username,
+ .uid = uid,
+ }
+ };
+
+ return context_raise(c, &event, 1);
+}
+
+static int context_raise_session_add(sysview_context *c, sysview_session *session) {
+ sysview_event event = {
+ .type = SYSVIEW_EVENT_SESSION_ADD,
+ .session_add = {
+ .session = session,
+ }
+ };
+
+ return context_raise(c, &event, 0);
+}
+
+static int context_raise_session_remove(sysview_context *c, sysview_session *session) {
+ sysview_event event = {
+ .type = SYSVIEW_EVENT_SESSION_REMOVE,
+ .session_remove = {
+ .session = session,
+ }
+ };
+
+ return context_raise(c, &event, 0);
+}
+
+static int context_raise_session_control(sysview_context *c, sysview_session *session, int error) {
+ sysview_event event = {
+ .type = SYSVIEW_EVENT_SESSION_CONTROL,
+ .session_control = {
+ .session = session,
+ .error = error,
+ }
+ };
+
+ return context_raise(c, &event, 0);
+}
+
+static int context_raise_session_attach(sysview_context *c, sysview_session *session, sysview_device *device) {
+ sysview_event event = {
+ .type = SYSVIEW_EVENT_SESSION_ATTACH,
+ .session_attach = {
+ .session = session,
+ .device = device,
+ }
+ };
+
+ return context_raise(c, &event, 0);
+}
+
+static int context_raise_session_detach(sysview_context *c, sysview_session *session, sysview_device *device) {
+ sysview_event event = {
+ .type = SYSVIEW_EVENT_SESSION_DETACH,
+ .session_detach = {
+ .session = session,
+ .device = device,
+ }
+ };
+
+ return context_raise(c, &event, 0);
+}
+
+static int context_add_device(sysview_context *c, sysview_device *device) {
+ sysview_session *session;
+ int r, error = 0;
+ Iterator i;
+
+ assert(c);
+ assert(device);
+
+ log_debug("sysview: add device '%s' on seat '%s'",
+ device->name, device->seat->name);
+
+ HASHMAP_FOREACH(session, device->seat->session_map, i) {
+ if (!session->public)
+ continue;
+
+ r = context_raise_session_attach(c, session, device);
+ if (r != 0)
+ error = r;
+ }
+
+ if (error < 0)
+ log_debug("sysview: error while adding device '%s': %s",
+ device->name, strerror(-r));
+ return error;
+}
+
+static int context_remove_device(sysview_context *c, sysview_device *device) {
+ sysview_session *session;
+ int r, error = 0;
+ Iterator i;
+
+ assert(c);
+ assert(device);
+
+ log_debug("sysview: remove device '%s'", device->name);
+
+ HASHMAP_FOREACH(session, device->seat->session_map, i) {
+ if (!session->public)
+ continue;
+
+ r = context_raise_session_detach(c, session, device);
+ if (r != 0)
+ error = r;
+ }
+
+ if (error < 0)
+ log_debug("sysview: error while removing device '%s': %s",
+ device->name, strerror(-r));
+ sysview_device_free(device);
+ return error;
+}
+
+static int context_add_session(sysview_context *c, sysview_seat *seat, const char *id) {
+ sysview_session *session;
+ sysview_device *device;
+ int r, error = 0;
+ Iterator i;
+
+ assert(c);
+ assert(seat);
+ assert(id);
+
+ session = sysview_find_session(c, id);
+ if (session)
+ return 0;
+
+ log_debug("sysview: add session '%s' on seat '%s'", id, seat->name);
+
+ r = sysview_session_new(&session, seat, id);
+ if (r < 0)
+ goto error;
+
+ if (!seat->scanned) {
+ r = sysview_context_rescan(c);
+ if (r < 0)
+ goto error;
+ }
+
+ if (seat->public) {
+ session->public = true;
+ r = context_raise_session_add(c, session);
+ if (r != 0) {
+ session->public = false;
+ goto error;
+ }
+
+ HASHMAP_FOREACH(device, seat->device_map, i) {
+ r = context_raise_session_attach(c, session, device);
+ if (r != 0)
+ error = r;
+ }
+
+ r = error;
+ if (r != 0)
+ goto error;
+ }
+
+ return 0;
+
+error:
+ if (r < 0)
+ log_debug("sysview: error while adding session '%s': %s",
+ id, strerror(-r));
+ return r;
+}
+
+static int context_remove_session(sysview_context *c, sysview_session *session) {
+ sysview_device *device;
+ int r, error = 0;
+ Iterator i;
+
+ assert(c);
+ assert(session);
+
+ log_debug("sysview: remove session '%s'", session->name);
+
+ if (session->public) {
+ HASHMAP_FOREACH(device, session->seat->device_map, i) {
+ r = context_raise_session_detach(c, session, device);
+ if (r != 0)
+ error = r;
+ }
+
+ session->public = false;
+ r = context_raise_session_remove(c, session);
+ if (r != 0)
+ error = r;
+ }
+
+ if (!session->custom)
+ sysview_session_release_control(session);
+
+ if (error < 0)
+ log_debug("sysview: error while removing session '%s': %s",
+ session->name, strerror(-error));
+ sysview_session_free(session);
+ return error;
+}
+
+static int context_add_seat(sysview_context *c, const char *id) {
+ sysview_seat *seat;
+ int r;
+
+ assert(c);
+ assert(id);
+
+ seat = sysview_find_seat(c, id);
+ if (seat)
+ return 0;
+
+ log_debug("sysview: add seat '%s'", id);
+
+ r = sysview_seat_new(&seat, c, id);
+ if (r < 0)
+ goto error;
+
+ seat->public = true;
+ r = context_raise_seat_add(c, seat);
+ if (r != 0) {
+ seat->public = false;
+ goto error;
+ }
+
+ return 0;
+
+error:
+ if (r < 0)
+ log_debug("sysview: error while adding seat '%s': %s",
+ id, strerror(-r));
+ return r;
+}
+
+static int context_remove_seat(sysview_context *c, sysview_seat *seat) {
+ sysview_session *session;
+ sysview_device *device;
+ int r, error = 0;
+
+ assert(c);
+ assert(seat);
+
+ log_debug("sysview: remove seat '%s'", seat->name);
+
+ while ((device = hashmap_first(seat->device_map))) {
+ r = context_remove_device(c, device);
+ if (r != 0)
+ error = r;
+ }
+
+ while ((session = hashmap_first(seat->session_map))) {
+ r = context_remove_session(c, session);
+ if (r != 0)
+ error = r;
+ }
+
+ if (seat->public) {
+ seat->public = false;
+ r = context_raise_seat_remove(c, seat);
+ if (r != 0)
+ error = r;
+ }
+
+ if (error < 0)
+ log_debug("sysview: error while removing seat '%s': %s",
+ seat->name, strerror(-error));
+ sysview_seat_free(seat);
+ return error;
+}
+
+int sysview_context_new(sysview_context **out,
+ unsigned int flags,
+ sd_event *event,
+ sd_bus *sysbus,
+ struct udev *ud) {
+ _cleanup_(sysview_context_freep) sysview_context *c = NULL;
+ int r;
+
+ assert_return(out, -EINVAL);
+ assert_return(event, -EINVAL);
+
+ log_debug("sysview: new");
+
+ c = new0(sysview_context, 1);
+ if (!c)
+ return -ENOMEM;
+
+ c->event = sd_event_ref(event);
+ if (flags & SYSVIEW_CONTEXT_SCAN_LOGIND)
+ c->scan_logind = true;
+ if (flags & SYSVIEW_CONTEXT_SCAN_EVDEV)
+ c->scan_evdev = true;
+ if (flags & SYSVIEW_CONTEXT_SCAN_DRM)
+ c->scan_drm = true;
+
+ if (sysbus) {
+ c->sysbus = sd_bus_ref(sysbus);
+ } else if (c->scan_logind) {
+ r = sd_bus_open_system(&c->sysbus);
+ if (r < 0)
+ return r;
+ }
+
+ if (ud) {
+ c->ud = udev_ref(ud);
+ } else if (c->scan_evdev || c->scan_drm) {
+ errno = 0;
+ c->ud = udev_new();
+ if (!c->ud)
+ return errno > 0 ? -errno : -EFAULT;
+ }
+
+ c->seat_map = hashmap_new(string_hash_func, string_compare_func);
+ if (!c->seat_map)
+ return -ENOMEM;
+
+ c->session_map = hashmap_new(string_hash_func, string_compare_func);
+ if (!c->session_map)
+ return -ENOMEM;
+
+ c->device_map = hashmap_new(string_hash_func, string_compare_func);
+ if (!c->device_map)
+ return -ENOMEM;
+
+ *out = c;
+ c = NULL;
+ return 0;
+}
+
+sysview_context *sysview_context_free(sysview_context *c) {
+ if (!c)
+ return NULL;
+
+ log_debug("sysview: free");
+
+ sysview_context_stop(c);
+
+ assert(hashmap_size(c->device_map) == 0);
+ assert(hashmap_size(c->session_map) == 0);
+ assert(hashmap_size(c->seat_map) == 0);
+
+ hashmap_free(c->device_map);
+ hashmap_free(c->session_map);
+ hashmap_free(c->seat_map);
+ c->ud = udev_unref(c->ud);
+ c->sysbus = sd_bus_unref(c->sysbus);
+ c->event = sd_event_unref(c->event);
+ free(c);
+
+ return NULL;
+}
+
+static int context_ud_prepare_monitor(sysview_context *c, struct udev_monitor *m) {
+ int r;
+
+ if (c->scan_evdev) {
+ r = udev_monitor_filter_add_match_subsystem_devtype(m, "input", NULL);
+ if (r < 0)
+ return r;
+ }
+
+ if (c->scan_drm) {
+ r = udev_monitor_filter_add_match_subsystem_devtype(m, "drm", NULL);
+ if (r < 0)
+ return r;
+ }
+
+ return r;
+}
+
+static int context_ud_prepare_scan(sysview_context *c, struct udev_enumerate *e) {
+ int r;
+
+ if (c->scan_evdev) {
+ r = udev_enumerate_add_match_subsystem(e, "input");
+ if (r < 0)
+ return r;
+ }
+
+ if (c->scan_drm) {
+ r = udev_enumerate_add_match_subsystem(e, "drm");
+ if (r < 0)
+ return r;
+ }
+
+ r = udev_enumerate_add_match_is_initialized(e);
+ if (r < 0)
+ return r;
+
+ return 0;
+}
+
+static int context_ud_hotplug(sysview_context *c, struct udev_device *d) {
+ const char *syspath, *sysname, *subsystem, *action, *seatname;
+ sysview_device *device;
+ int r;
+
+ syspath = udev_device_get_syspath(d);
+ sysname = udev_device_get_sysname(d);
+ subsystem = udev_device_get_subsystem(d);
+ action = udev_device_get_action(d);
+
+ /* not interested in custom devices without syspath/etc */
+ if (!syspath || !sysname || !subsystem)
+ return 0;
+
+ device = sysview_find_device(c, syspath);
+
+ if (streq_ptr(action, "remove")) {
+ if (!device)
+ return 0;
+
+ return context_remove_device(c, device);
+ } else if (streq_ptr(action, "change")) {
+ if (!device)
+ return 0;
+
+ /* TODO: send REFRESH event */
+ } else if (!action || streq_ptr(action, "add")) {
+ struct udev_device *p;
+ unsigned int type, t;
+ sysview_seat *seat;
+
+ if (device)
+ return 0;
+
+ if (streq(subsystem, "input") && startswith(sysname, "event") && safe_atou(sysname + 5, &t) >= 0)
+ type = SYSVIEW_DEVICE_EVDEV;
+ else if (streq(subsystem, "drm") && startswith(sysname, "card") && safe_atou(sysname + 4, &t) >= 0)
+ type = SYSVIEW_DEVICE_DRM;
+ else
+ type = (unsigned)-1;
+
+ if (type >= SYSVIEW_DEVICE_CNT)
+ return 0;
+
+ p = d;
+ seatname = NULL;
+ while ((p = udev_device_get_parent(p))) {
+ seatname = udev_device_get_property_value(p, "ID_SEAT");
+ if (seatname)
+ break;
+ }
+
+ seat = sysview_find_seat(c, seatname ? : "seat0");
+ if (!seat)
+ return 0;
+
+ r = device_new_ud(&device, seat, type, d);
+ if (r < 0) {
+ log_debug("sysview: cannot create device for udev-device '%s': %s",
+ syspath, strerror(-r));
+ return r;
+ }
+
+ return context_add_device(c, device);
+ }
+
+ return 0;
+}
+
+static int context_ud_monitor_fn(sd_event_source *s,
+ int fd,
+ uint32_t revents,
+ void *userdata) {
+ sysview_context *c = userdata;
+ struct udev_device *d;
+ int r;
+
+ if (revents & EPOLLIN) {
+ while ((d = udev_monitor_receive_device(c->ud_monitor))) {
+ r = context_ud_hotplug(c, d);
+ udev_device_unref(d);
+ if (r != 0)
+ return r;
+ }
+
+ /* as long as EPOLLIN is signalled, read pending data */
+ return 0;
+ }
+
+ if (revents & (EPOLLHUP | EPOLLERR)) {
+ log_debug("sysview: HUP on udev-monitor");
+ c->ud_monitor_src = sd_event_source_unref(c->ud_monitor_src);
+ }
+
+ return 0;
+}
+
+static int context_ud_start(sysview_context *c) {
+ int r, fd;
+
+ if (!c->ud)
+ return 0;
+
+ errno = 0;
+ c->ud_monitor = udev_monitor_new_from_netlink(c->ud, "udev");
+ if (!c->ud_monitor)
+ return errno > 0 ? -errno : -EFAULT;
+
+ r = context_ud_prepare_monitor(c, c->ud_monitor);
+ if (r < 0)
+ return r;
+
+ r = udev_monitor_enable_receiving(c->ud_monitor);
+ if (r < 0)
+ return r;
+
+ fd = udev_monitor_get_fd(c->ud_monitor);
+ r = sd_event_add_io(c->event,
+ &c->ud_monitor_src,
+ fd,
+ EPOLLHUP | EPOLLERR | EPOLLIN,
+ context_ud_monitor_fn,
+ c);
+ if (r < 0)
+ return r;
+
+ return 0;
+}
+
+static void context_ud_stop(sysview_context *c) {
+ c->ud_monitor_src = sd_event_source_unref(c->ud_monitor_src);
+ c->ud_monitor = udev_monitor_unref(c->ud_monitor);
+}
+
+static int context_ud_scan(sysview_context *c) {
+ _cleanup_(udev_enumerate_unrefp) struct udev_enumerate *e = NULL;
+ struct udev_list_entry *entry;
+ struct udev_device *d;
+ int r;
+
+ if (!c->ud_monitor)
+ return 0;
+
+ errno = 0;
+ e = udev_enumerate_new(c->ud);
+ if (!e)
+ return errno > 0 ? -errno : -EFAULT;
+
+ r = context_ud_prepare_scan(c, e);
+ if (r < 0)
+ return r;
+
+ r = udev_enumerate_scan_devices(e);
+ if (r < 0)
+ return r;
+
+ udev_list_entry_foreach(entry, udev_enumerate_get_list_entry(e)) {
+ const char *name;
+
+ name = udev_list_entry_get_name(entry);
+
+ errno = 0;
+ d = udev_device_new_from_syspath(c->ud, name);
+ if (!d) {
+ r = errno > 0 ? -errno : -EFAULT;
+ log_debug("sysview: cannot create udev-device for %s: %s",
+ name, strerror(-r));
+ continue;
+ }
+
+ r = context_ud_hotplug(c, d);
+ udev_device_unref(d);
+ if (r != 0)
+ return r;
+ }
+
+ return 0;
+}
+
+static int context_ld_seat_new(sysview_context *c, sd_bus_message *signal) {
+ const char *id, *path;
+ int r;
+
+ r = sd_bus_message_read(signal, "so", &id, &path);
+ if (r < 0) {
+ log_debug("sysview: cannot parse SeatNew from logind: %s",
+ strerror(-r));
+ return r;
+ }
+
+ return context_add_seat(c, id);
+}
+
+static int context_ld_seat_removed(sysview_context *c, sd_bus_message *signal) {
+ const char *id, *path;
+ sysview_seat *seat;
+ int r;
+
+ r = sd_bus_message_read(signal, "so", &id, &path);
+ if (r < 0) {
+ log_debug("sysview: cannot parse SeatRemoved from logind: %s",
+ strerror(-r));
+ return r;
+ }
+
+ seat = sysview_find_seat(c, id);
+ if (!seat)
+ return 0;
+
+ return context_remove_seat(c, seat);
+}
+
+static int context_ld_session_new(sysview_context *c, sd_bus_message *signal) {
+ _cleanup_free_ char *seatid = NULL, *username = NULL;
+ const char *id, *path;
+ sysview_seat *seat;
+ uid_t uid;
+ int r;
+
+ r = sd_bus_message_read(signal, "so", &id, &path);
+ if (r < 0) {
+ log_debug("sysview: cannot parse SessionNew from logind: %s",
+ strerror(-r));
+ return r;
+ }
+
+ /*
+ * As the dbus message didn't contain enough information, we
+ * read missing bits via sd-login. Note that this might race session
+ * destruction, so we handle ENOENT properly.
+ */
+
+ /* ENOENT is also returned for sessions without seats */
+ r = sd_session_get_seat(id, &seatid);
+ if (r == -ENOENT)
+ return 0;
+ else if (r < 0)
+ goto error;
+
+ seat = sysview_find_seat(c, seatid);
+ if (!seat)
+ return 0;
+
+ r = sd_session_get_uid(id, &uid);
+ if (r == -ENOENT)
+ return 0;
+ else if (r < 0)
+ goto error;
+
+ username = lookup_uid(uid);
+ if (!username) {
+ r = -ENOMEM;
+ goto error;
+ }
+
+ r = context_raise_session_filter(c, id, seatid, username, uid);
+ if (r <= 0) {
+ if (r < 0)
+ log_debug("sysview: cannot filter new session '%s' on seat '%s': %s",
+ id, seatid, strerror(-r));
+ return r;
+ }
+
+ return context_add_session(c, seat, id);
+
+error:
+ log_debug("sysview: failed retrieving information for new session '%s': %s",
+ id, strerror(-r));
+ return r;
+}
+
+static int context_ld_session_removed(sysview_context *c, sd_bus_message *signal) {
+ sysview_session *session;
+ const char *id, *path;
+ int r;
+
+ r = sd_bus_message_read(signal, "so", &id, &path);
+ if (r < 0) {
+ log_debug("sysview: cannot parse SessionRemoved from logind: %s",
+ strerror(-r));
+ return r;
+ }
+
+ session = sysview_find_session(c, id);
+ if (!session)
+ return 0;
+
+ return context_remove_session(c, session);
+}
+
+static int context_ld_manager_signal_fn(sd_bus *bus,
+ sd_bus_message *signal,
+ void *userdata,
+ sd_bus_error *ret_error) {
+ sysview_context *c = userdata;
+
+ if (sd_bus_message_is_signal(signal, "org.freedesktop.login1.Manager", "SeatNew"))
+ return context_ld_seat_new(c, signal);
+ else if (sd_bus_message_is_signal(signal, "org.freedesktop.login1.Manager", "SeatRemoved"))
+ return context_ld_seat_removed(c, signal);
+ else if (sd_bus_message_is_signal(signal, "org.freedesktop.login1.Manager", "SessionNew"))
+ return context_ld_session_new(c, signal);
+ else if (sd_bus_message_is_signal(signal, "org.freedesktop.login1.Manager", "SessionRemoved"))
+ return context_ld_session_removed(c, signal);
+ else
+ return 0;
+}
+
+static int context_ld_start(sysview_context *c) {
+ int r;
+
+ if (!c->scan_logind)
+ return 0;
+
+ r = sd_bus_add_match(c->sysbus,
+ &c->ld_slot_manager_signal,
+ "type='signal',"
+ "sender='org.freedesktop.login1',"
+ "interface='org.freedesktop.login1.Manager',"
+ "path='/org/freedesktop/login1'",
+ context_ld_manager_signal_fn,
+ c);
+ if (r < 0)
+ return r;
+
+ return 0;
+}
+
+static void context_ld_stop(sysview_context *c) {
+ c->ld_slot_list_sessions = sd_bus_slot_unref(c->ld_slot_list_sessions);
+ c->ld_slot_list_seats = sd_bus_slot_unref(c->ld_slot_list_seats);
+ c->ld_slot_manager_signal = sd_bus_slot_unref(c->ld_slot_manager_signal);
+}
+
+static int context_ld_list_seats_fn(sd_bus *bus,
+ sd_bus_message *reply,
+ void *userdata,
+ sd_bus_error *ret_error) {
+ sysview_context *c = userdata;
+ int r;
+
+ c->ld_slot_list_seats = sd_bus_slot_unref(c->ld_slot_list_seats);
+
+ if (sd_bus_message_is_method_error(reply, NULL)) {
+ const sd_bus_error *error = sd_bus_message_get_error(reply);
+
+ log_debug("sysview: ListSeats on logind failed: %s: %s",
+ error->name, error->message);
+ return sd_bus_error_get_errno(error);
+ }
+
+ r = sd_bus_message_enter_container(reply, 'a', "(so)");
+ if (r < 0)
+ goto error;
+
+ while ((r = sd_bus_message_enter_container(reply, 'r', "so")) > 0) {
+ const char *id, *path;
+
+ r = sd_bus_message_read(reply, "so", &id, &path);
+ if (r < 0)
+ goto error;
+
+ r = context_add_seat(c, id);
+ if (r != 0)
+ return r;
+
+ r = sd_bus_message_exit_container(reply);
+ if (r < 0)
+ goto error;
+ }
+
+ if (r < 0)
+ goto error;
+
+ r = sd_bus_message_exit_container(reply);
+ if (r < 0)
+ return r;
+
+ return 0;
+
+error:
+ log_debug("sysview: erroneous ListSeats response from logind: %s",
+ strerror(-r));
+ return r;
+}
+
+static int context_ld_list_sessions_fn(sd_bus *bus,
+ sd_bus_message *reply,
+ void *userdata,
+ sd_bus_error *ret_error) {
+ sysview_context *c = userdata;
+ int r;
+
+ c->ld_slot_list_sessions = sd_bus_slot_unref(c->ld_slot_list_sessions);
+
+ if (sd_bus_message_is_method_error(reply, NULL)) {
+ const sd_bus_error *error = sd_bus_message_get_error(reply);
+
+ log_debug("sysview: ListSessions on logind failed: %s: %s",
+ error->name, error->message);
+ return sd_bus_error_get_errno(error);
+ }
+
+ r = sd_bus_message_enter_container(reply, 'a', "(susso)");
+ if (r < 0)
+ goto error;
+
+ while ((r = sd_bus_message_enter_container(reply, 'r', "susso")) > 0) {
+ const char *id, *username, *seatid, *path;
+ sysview_seat *seat;
+ unsigned int uid;
+
+ r = sd_bus_message_read(reply,
+ "susso",
+ &id,
+ &uid,
+ &username,
+ &seatid,
+ &path);
+ if (r < 0)
+ goto error;
+
+ seat = sysview_find_seat(c, seatid);
+ if (seat) {
+ r = context_raise_session_filter(c, id, seatid, username, uid);
+ if (r < 0) {
+ log_debug("sysview: cannot filter listed session '%s' on seat '%s': %s",
+ id, seatid, strerror(-r));
+ return r;
+ } else if (r > 0) {
+ r = context_add_session(c, seat, id);
+ if (r != 0)
+ return r;
+ }
+ }
+
+ r = sd_bus_message_exit_container(reply);
+ if (r < 0)
+ goto error;
+ }
+
+ if (r < 0)
+ goto error;
+
+ r = sd_bus_message_exit_container(reply);
+ if (r < 0)
+ return r;
+
+ return 0;
+
+error:
+ log_debug("sysview: erroneous ListSessions response from logind: %s",
+ strerror(-r));
+ return r;
+}
+
+static int context_ld_scan(sysview_context *c) {
+ _cleanup_bus_message_unref_ sd_bus_message *m = NULL;
+ int r;
+
+ if (!c->ld_slot_manager_signal)
+ return 0;
+
+ /* request seat list */
+
+ r = sd_bus_message_new_method_call(c->sysbus,
+ &m,
+ "org.freedesktop.login1",
+ "/org/freedesktop/login1",
+ "org.freedesktop.login1.Manager",
+ "ListSeats");
+ if (r < 0)
+ return r;
+
+ r = sd_bus_call_async(c->sysbus,
+ &c->ld_slot_list_seats,
+ m,
+ context_ld_list_seats_fn,
+ c,
+ 0);
+ if (r < 0)
+ return r;
+
+ /* request session list */
+
+ m = sd_bus_message_unref(m);
+ r = sd_bus_message_new_method_call(c->sysbus,
+ &m,
+ "org.freedesktop.login1",
+ "/org/freedesktop/login1",
+ "org.freedesktop.login1.Manager",
+ "ListSessions");
+ if (r < 0)
+ return r;
+
+ r = sd_bus_call_async(c->sysbus,
+ &c->ld_slot_list_sessions,
+ m,
+ context_ld_list_sessions_fn,
+ c,
+ 0);
+ if (r < 0)
+ return r;
+
+ return 0;
+}
+
+bool sysview_context_is_running(sysview_context *c) {
+ return c && c->running;
+}
+
+int sysview_context_start(sysview_context *c, sysview_event_fn event_fn, void *userdata) {
+ int r;
+
+ assert_return(c, -EINVAL);
+ assert_return(event_fn, -EINVAL);
+
+ if (c->running)
+ return -EALREADY;
+
+ log_debug("sysview: start");
+
+ c->running = true;
+ c->event_fn = event_fn;
+ c->userdata = userdata;
+
+ r = context_ld_start(c);
+ if (r < 0)
+ goto error;
+
+ r = context_ud_start(c);
+ if (r < 0)
+ goto error;
+
+ r = sysview_context_rescan(c);
+ if (r < 0)
+ goto error;
+
+ return 0;
+
+error:
+ sysview_context_stop(c);
+ return r;
+}
+
+void sysview_context_stop(sysview_context *c) {
+ sysview_session *session;
+ sysview_device *device;
+ sysview_seat *seat;
+
+ assert(c);
+
+ if (!c->running)
+ return;
+
+ log_debug("sysview: stop");
+
+ c->running = false;
+ c->scanned = false;
+ c->event_fn = NULL;
+ c->userdata = NULL;
+ c->scan_src = sd_event_source_unref(c->scan_src);
+ context_ud_stop(c);
+ context_ld_stop(c);
+
+ /*
+ * Event-callbacks are already cleared, hence we can safely ignore
+ * return codes of the context_remove_*() helpers. They cannot be
+ * originated from user-callbacks, so we already handled them.
+ */
+
+ while ((device = hashmap_first(c->device_map)))
+ context_remove_device(c, device);
+
+ while ((session = hashmap_first(c->session_map)))
+ context_remove_session(c, session);
+
+ while ((seat = hashmap_first(c->seat_map)))
+ context_remove_seat(c, seat);
+}
+
+static int context_scan_fn(sd_event_source *s, void *userdata) {
+ sysview_context *c = userdata;
+ sysview_seat *seat;
+ Iterator i;
+ int r;
+
+ if (!c->scanned) {
+ r = context_ld_scan(c);
+ if (r < 0) {
+ log_debug("sysview: logind scan failed: %s", strerror(-r));
+ return r;
+ }
+ }
+
+ /* skip device scans if no sessions are available */
+ if (hashmap_size(c->session_map) > 0) {
+ r = context_ud_scan(c);
+ if (r < 0) {
+ log_debug("sysview: udev scan failed: %s", strerror(-r));
+ return r;
+ }
+
+ HASHMAP_FOREACH(seat, c->seat_map, i)
+ seat->scanned = true;
+ }
+
+ c->scanned = true;
+
+ return 0;
+}
+
+int sysview_context_rescan(sysview_context *c) {
+ assert(c);
+
+ if (!c->running)
+ return 0;
+
+ if (c->scan_src)
+ return sd_event_source_set_enabled(c->scan_src, SD_EVENT_ONESHOT);
+ else
+ return sd_event_add_defer(c->event, &c->scan_src, context_scan_fn, c);
+}
diff --git a/src/libsystemd-terminal/sysview.h b/src/libsystemd-terminal/sysview.h
new file mode 100644
index 0000000000..de6ff371db
--- /dev/null
+++ b/src/libsystemd-terminal/sysview.h
@@ -0,0 +1,151 @@
+/*-*- 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/>.
+***/
+
+/*
+ * System View
+ * The sysview interface scans and monitors the system for seats, sessions and
+ * devices. It basically mirrors the state of logind on the application side.
+ * It's meant as base for session services that require managed device access.
+ * The logind controller API is employed to allow unprivileged access to all
+ * devices of a user.
+ * Furthermore, the sysview interface can be used for system services that run
+ * in situations where logind is not available, but session-like services are
+ * needed. For instance, the initrd does not run logind but might require
+ * graphics access. It cannot run session services, though. The sysview
+ * interface pretends that a session is available and provides the same
+ * interface as to normal session services.
+ */
+
+#pragma once
+
+#include <inttypes.h>
+#include <libudev.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <systemd/sd-bus.h>
+#include <systemd/sd-event.h>
+#include "util.h"
+
+typedef struct sysview_event sysview_event;
+typedef struct sysview_device sysview_device;
+typedef struct sysview_session sysview_session;
+typedef struct sysview_seat sysview_seat;
+typedef struct sysview_context sysview_context;
+
+/*
+ * Events
+ */
+
+enum {
+ SYSVIEW_EVENT_SEAT_ADD,
+ SYSVIEW_EVENT_SEAT_REMOVE,
+
+ SYSVIEW_EVENT_SESSION_FILTER,
+ SYSVIEW_EVENT_SESSION_ADD,
+ SYSVIEW_EVENT_SESSION_REMOVE,
+ SYSVIEW_EVENT_SESSION_ATTACH,
+ SYSVIEW_EVENT_SESSION_DETACH,
+ SYSVIEW_EVENT_SESSION_CONTROL,
+};
+
+struct sysview_event {
+ unsigned int type;
+
+ union {
+ struct {
+ sysview_seat *seat;
+ } seat_add, seat_remove;
+
+ struct {
+ const char *id;
+ const char *seatid;
+ const char *username;
+ unsigned int uid;
+ } session_filter;
+
+ struct {
+ sysview_session *session;
+ } session_add, session_remove;
+
+ struct {
+ sysview_session *session;
+ sysview_device *device;
+ } session_attach, session_detach;
+
+ struct {
+ sysview_session *session;
+ int error;
+ } session_control;
+ };
+};
+
+typedef int (*sysview_event_fn) (sysview_context *c, void *userdata, sysview_event *e);
+
+/*
+ * Devices
+ */
+
+enum {
+ SYSVIEW_DEVICE_EVDEV,
+ SYSVIEW_DEVICE_DRM,
+ SYSVIEW_DEVICE_CNT
+};
+
+unsigned int sysview_device_get_type(sysview_device *device);
+struct udev_device *sysview_device_get_ud(sysview_device *device);
+
+/*
+ * Sessions
+ */
+
+const char *sysview_session_get_name(sysview_session *session);
+
+int sysview_session_take_control(sysview_session *session);
+void sysview_session_release_control(sysview_session *session);
+
+/*
+ * Seats
+ */
+
+const char *sysview_seat_get_name(sysview_seat *seat);
+
+/*
+ * Contexts
+ */
+
+enum {
+ SYSVIEW_CONTEXT_SCAN_LOGIND = (1 << 0),
+ SYSVIEW_CONTEXT_SCAN_EVDEV = (1 << 1),
+ SYSVIEW_CONTEXT_SCAN_DRM = (1 << 2),
+};
+
+int sysview_context_new(sysview_context **out,
+ unsigned int flags,
+ sd_event *event,
+ sd_bus *sysbus,
+ struct udev *ud);
+sysview_context *sysview_context_free(sysview_context *c);
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(sysview_context*, sysview_context_free);
+
+bool sysview_context_is_running(sysview_context *c);
+int sysview_context_start(sysview_context *c, sysview_event_fn event_fn, void *userdata);
+void sysview_context_stop(sysview_context *c);