Systemd/src/login/logind-session-dbus.c
Franck Bui aed24c4cd7 logind: save/restore session devices and their respective file descriptors
This patch ensures that session devices are saved for each session.

In order to make the revokation logic work when logind is restarted, the
session devices are now saved in the session state files and their respective
file descriptors sent to PID1's fdstore in order to keep them open accross
restart.

This is mandatory in order to keep the revokation logic working. Indeed in case
of input-devices, the same file descriptors must be shared by logind and a
given session controller in order EVIOCREVOKE to work otherwise multiple
sessions can have device access in parallel.

This should be the only remaining and missing piece for making logind fully
restartable.

Fixes: #1163
2017-06-08 16:21:36 +02:00

810 lines
26 KiB
C

/***
This file is part of systemd.
Copyright 2011 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <errno.h>
#include <string.h>
#include "alloc-util.h"
#include "bus-common-errors.h"
#include "bus-label.h"
#include "bus-util.h"
#include "fd-util.h"
#include "logind-session-device.h"
#include "logind-session.h"
#include "logind.h"
#include "signal-util.h"
#include "strv.h"
#include "util.h"
static int property_get_user(
sd_bus *bus,
const char *path,
const char *interface,
const char *property,
sd_bus_message *reply,
void *userdata,
sd_bus_error *error) {
_cleanup_free_ char *p = NULL;
Session *s = userdata;
assert(bus);
assert(reply);
assert(s);
p = user_bus_path(s->user);
if (!p)
return -ENOMEM;
return sd_bus_message_append(reply, "(uo)", (uint32_t) s->user->uid, p);
}
static int property_get_name(
sd_bus *bus,
const char *path,
const char *interface,
const char *property,
sd_bus_message *reply,
void *userdata,
sd_bus_error *error) {
Session *s = userdata;
assert(bus);
assert(reply);
assert(s);
return sd_bus_message_append(reply, "s", s->user->name);
}
static int property_get_seat(
sd_bus *bus,
const char *path,
const char *interface,
const char *property,
sd_bus_message *reply,
void *userdata,
sd_bus_error *error) {
_cleanup_free_ char *p = NULL;
Session *s = userdata;
assert(bus);
assert(reply);
assert(s);
p = s->seat ? seat_bus_path(s->seat) : strdup("/");
if (!p)
return -ENOMEM;
return sd_bus_message_append(reply, "(so)", s->seat ? s->seat->id : "", p);
}
static BUS_DEFINE_PROPERTY_GET_ENUM(property_get_type, session_type, SessionType);
static BUS_DEFINE_PROPERTY_GET_ENUM(property_get_class, session_class, SessionClass);
static int property_get_active(
sd_bus *bus,
const char *path,
const char *interface,
const char *property,
sd_bus_message *reply,
void *userdata,
sd_bus_error *error) {
Session *s = userdata;
assert(bus);
assert(reply);
assert(s);
return sd_bus_message_append(reply, "b", session_is_active(s));
}
static int property_get_state(
sd_bus *bus,
const char *path,
const char *interface,
const char *property,
sd_bus_message *reply,
void *userdata,
sd_bus_error *error) {
Session *s = userdata;
assert(bus);
assert(reply);
assert(s);
return sd_bus_message_append(reply, "s", session_state_to_string(session_get_state(s)));
}
static int property_get_idle_hint(
sd_bus *bus,
const char *path,
const char *interface,
const char *property,
sd_bus_message *reply,
void *userdata,
sd_bus_error *error) {
Session *s = userdata;
assert(bus);
assert(reply);
assert(s);
return sd_bus_message_append(reply, "b", session_get_idle_hint(s, NULL) > 0);
}
static int property_get_idle_since_hint(
sd_bus *bus,
const char *path,
const char *interface,
const char *property,
sd_bus_message *reply,
void *userdata,
sd_bus_error *error) {
Session *s = userdata;
dual_timestamp t = DUAL_TIMESTAMP_NULL;
uint64_t u;
int r;
assert(bus);
assert(reply);
assert(s);
r = session_get_idle_hint(s, &t);
if (r < 0)
return r;
u = streq(property, "IdleSinceHint") ? t.realtime : t.monotonic;
return sd_bus_message_append(reply, "t", u);
}
static int property_get_locked_hint(
sd_bus *bus,
const char *path,
const char *interface,
const char *property,
sd_bus_message *reply,
void *userdata,
sd_bus_error *error) {
Session *s = userdata;
assert(bus);
assert(reply);
assert(s);
return sd_bus_message_append(reply, "b", session_get_locked_hint(s) > 0);
}
int bus_session_method_terminate(sd_bus_message *message, void *userdata, sd_bus_error *error) {
Session *s = userdata;
int r;
assert(message);
assert(s);
r = bus_verify_polkit_async(
message,
CAP_KILL,
"org.freedesktop.login1.manage",
NULL,
false,
s->user->uid,
&s->manager->polkit_registry,
error);
if (r < 0)
return r;
if (r == 0)
return 1; /* Will call us back */
r = session_stop(s, true);
if (r < 0)
return r;
return sd_bus_reply_method_return(message, NULL);
}
int bus_session_method_activate(sd_bus_message *message, void *userdata, sd_bus_error *error) {
Session *s = userdata;
int r;
assert(message);
assert(s);
r = session_activate(s);
if (r < 0)
return r;
return sd_bus_reply_method_return(message, NULL);
}
int bus_session_method_lock(sd_bus_message *message, void *userdata, sd_bus_error *error) {
Session *s = userdata;
int r;
assert(message);
assert(s);
r = bus_verify_polkit_async(
message,
CAP_SYS_ADMIN,
"org.freedesktop.login1.lock-sessions",
NULL,
false,
s->user->uid,
&s->manager->polkit_registry,
error);
if (r < 0)
return r;
if (r == 0)
return 1; /* Will call us back */
r = session_send_lock(s, strstr(sd_bus_message_get_member(message), "Lock"));
if (r < 0)
return r;
return sd_bus_reply_method_return(message, NULL);
}
static int method_set_idle_hint(sd_bus_message *message, void *userdata, sd_bus_error *error) {
_cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL;
Session *s = userdata;
uid_t uid;
int r, b;
assert(message);
assert(s);
r = sd_bus_message_read(message, "b", &b);
if (r < 0)
return r;
r = sd_bus_query_sender_creds(message, SD_BUS_CREDS_EUID, &creds);
if (r < 0)
return r;
r = sd_bus_creds_get_euid(creds, &uid);
if (r < 0)
return r;
if (uid != 0 && uid != s->user->uid)
return sd_bus_error_setf(error, SD_BUS_ERROR_ACCESS_DENIED, "Only owner of session may set idle hint");
session_set_idle_hint(s, b);
return sd_bus_reply_method_return(message, NULL);
}
static int method_set_locked_hint(sd_bus_message *message, void *userdata, sd_bus_error *error) {
_cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL;
Session *s = userdata;
uid_t uid;
int r, b;
assert(message);
assert(s);
r = sd_bus_message_read(message, "b", &b);
if (r < 0)
return r;
r = sd_bus_query_sender_creds(message, SD_BUS_CREDS_EUID, &creds);
if (r < 0)
return r;
r = sd_bus_creds_get_euid(creds, &uid);
if (r < 0)
return r;
if (uid != 0 && uid != s->user->uid)
return sd_bus_error_setf(error, SD_BUS_ERROR_ACCESS_DENIED, "Only owner of session may set locked hint");
session_set_locked_hint(s, b);
return sd_bus_reply_method_return(message, NULL);
}
int bus_session_method_kill(sd_bus_message *message, void *userdata, sd_bus_error *error) {
Session *s = userdata;
const char *swho;
int32_t signo;
KillWho who;
int r;
assert(message);
assert(s);
r = sd_bus_message_read(message, "si", &swho, &signo);
if (r < 0)
return r;
if (isempty(swho))
who = KILL_ALL;
else {
who = kill_who_from_string(swho);
if (who < 0)
return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid kill parameter '%s'", swho);
}
if (!SIGNAL_VALID(signo))
return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid signal %i", signo);
r = bus_verify_polkit_async(
message,
CAP_KILL,
"org.freedesktop.login1.manage",
NULL,
false,
s->user->uid,
&s->manager->polkit_registry,
error);
if (r < 0)
return r;
if (r == 0)
return 1; /* Will call us back */
r = session_kill(s, who, signo);
if (r < 0)
return r;
return sd_bus_reply_method_return(message, NULL);
}
static int method_take_control(sd_bus_message *message, void *userdata, sd_bus_error *error) {
_cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL;
Session *s = userdata;
int r, force;
uid_t uid;
assert(message);
assert(s);
r = sd_bus_message_read(message, "b", &force);
if (r < 0)
return r;
r = sd_bus_query_sender_creds(message, SD_BUS_CREDS_EUID, &creds);
if (r < 0)
return r;
r = sd_bus_creds_get_euid(creds, &uid);
if (r < 0)
return r;
if (uid != 0 && (force || uid != s->user->uid))
return sd_bus_error_setf(error, SD_BUS_ERROR_ACCESS_DENIED, "Only owner of session may take control");
r = session_set_controller(s, sd_bus_message_get_sender(message), force, true);
if (r < 0)
return r;
return sd_bus_reply_method_return(message, NULL);
}
static int method_release_control(sd_bus_message *message, void *userdata, sd_bus_error *error) {
Session *s = userdata;
assert(message);
assert(s);
if (!session_is_controller(s, sd_bus_message_get_sender(message)))
return sd_bus_error_setf(error, BUS_ERROR_NOT_IN_CONTROL, "You are not in control of this session");
session_drop_controller(s);
return sd_bus_reply_method_return(message, NULL);
}
static int method_take_device(sd_bus_message *message, void *userdata, sd_bus_error *error) {
Session *s = userdata;
uint32_t major, minor;
SessionDevice *sd;
dev_t dev;
int r;
assert(message);
assert(s);
r = sd_bus_message_read(message, "uu", &major, &minor);
if (r < 0)
return r;
if (!session_is_controller(s, sd_bus_message_get_sender(message)))
return sd_bus_error_setf(error, BUS_ERROR_NOT_IN_CONTROL, "You are not in control of this session");
dev = makedev(major, minor);
sd = hashmap_get(s->devices, &dev);
if (sd)
/* We don't allow retrieving a device multiple times.
* The related ReleaseDevice call is not ref-counted.
* The caller should use dup() if it requires more
* than one fd (it would be functionally
* equivalent). */
return sd_bus_error_setf(error, BUS_ERROR_DEVICE_IS_TAKEN, "Device already taken");
r = session_device_new(s, dev, true, &sd);
if (r < 0)
return r;
r = session_device_save(sd);
if (r < 0)
goto error;
r = sd_bus_reply_method_return(message, "hb", sd->fd, !sd->active);
if (r < 0)
goto error;
session_save(s);
return 0;
error:
session_device_free(sd);
return r;
}
static int method_release_device(sd_bus_message *message, void *userdata, sd_bus_error *error) {
Session *s = userdata;
uint32_t major, minor;
SessionDevice *sd;
dev_t dev;
int r;
assert(message);
assert(s);
r = sd_bus_message_read(message, "uu", &major, &minor);
if (r < 0)
return r;
if (!session_is_controller(s, sd_bus_message_get_sender(message)))
return sd_bus_error_setf(error, BUS_ERROR_NOT_IN_CONTROL, "You are not in control of this session");
dev = makedev(major, minor);
sd = hashmap_get(s->devices, &dev);
if (!sd)
return sd_bus_error_setf(error, BUS_ERROR_DEVICE_NOT_TAKEN, "Device not taken");
session_device_free(sd);
session_save(s);
return sd_bus_reply_method_return(message, NULL);
}
static int method_pause_device_complete(sd_bus_message *message, void *userdata, sd_bus_error *error) {
Session *s = userdata;
uint32_t major, minor;
SessionDevice *sd;
dev_t dev;
int r;
assert(message);
assert(s);
r = sd_bus_message_read(message, "uu", &major, &minor);
if (r < 0)
return r;
if (!session_is_controller(s, sd_bus_message_get_sender(message)))
return sd_bus_error_setf(error, BUS_ERROR_NOT_IN_CONTROL, "You are not in control of this session");
dev = makedev(major, minor);
sd = hashmap_get(s->devices, &dev);
if (!sd)
return sd_bus_error_setf(error, BUS_ERROR_DEVICE_NOT_TAKEN, "Device not taken");
session_device_complete_pause(sd);
return sd_bus_reply_method_return(message, NULL);
}
const sd_bus_vtable session_vtable[] = {
SD_BUS_VTABLE_START(0),
SD_BUS_PROPERTY("Id", "s", NULL, offsetof(Session, id), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("User", "(uo)", property_get_user, 0, SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("Name", "s", property_get_name, 0, SD_BUS_VTABLE_PROPERTY_CONST),
BUS_PROPERTY_DUAL_TIMESTAMP("Timestamp", offsetof(Session, timestamp), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("VTNr", "u", NULL, offsetof(Session, vtnr), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("Seat", "(so)", property_get_seat, 0, SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("TTY", "s", NULL, offsetof(Session, tty), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("Display", "s", NULL, offsetof(Session, display), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("Remote", "b", bus_property_get_bool, offsetof(Session, remote), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("RemoteHost", "s", NULL, offsetof(Session, remote_host), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("RemoteUser", "s", NULL, offsetof(Session, remote_user), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("Service", "s", NULL, offsetof(Session, service), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("Desktop", "s", NULL, offsetof(Session, desktop), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("Scope", "s", NULL, offsetof(Session, scope), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("Leader", "u", bus_property_get_pid, offsetof(Session, leader), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("Audit", "u", NULL, offsetof(Session, audit_id), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("Type", "s", property_get_type, offsetof(Session, type), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("Class", "s", property_get_class, offsetof(Session, class), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("Active", "b", property_get_active, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
SD_BUS_PROPERTY("State", "s", property_get_state, 0, 0),
SD_BUS_PROPERTY("IdleHint", "b", property_get_idle_hint, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
SD_BUS_PROPERTY("IdleSinceHint", "t", property_get_idle_since_hint, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
SD_BUS_PROPERTY("IdleSinceHintMonotonic", "t", property_get_idle_since_hint, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
SD_BUS_PROPERTY("LockedHint", "b", property_get_locked_hint, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
SD_BUS_METHOD("Terminate", NULL, NULL, bus_session_method_terminate, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_METHOD("Activate", NULL, NULL, bus_session_method_activate, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_METHOD("Lock", NULL, NULL, bus_session_method_lock, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_METHOD("Unlock", NULL, NULL, bus_session_method_lock, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_METHOD("SetIdleHint", "b", NULL, method_set_idle_hint, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_METHOD("SetLockedHint", "b", NULL, method_set_locked_hint, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_METHOD("Kill", "si", NULL, bus_session_method_kill, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_METHOD("TakeControl", "b", NULL, method_take_control, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_METHOD("ReleaseControl", NULL, NULL, method_release_control, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_METHOD("TakeDevice", "uu", "hb", method_take_device, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_METHOD("ReleaseDevice", "uu", NULL, method_release_device, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_METHOD("PauseDeviceComplete", "uu", NULL, method_pause_device_complete, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_SIGNAL("PauseDevice", "uus", 0),
SD_BUS_SIGNAL("ResumeDevice", "uuh", 0),
SD_BUS_SIGNAL("Lock", NULL, 0),
SD_BUS_SIGNAL("Unlock", NULL, 0),
SD_BUS_VTABLE_END
};
int session_object_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error) {
Manager *m = userdata;
Session *session;
int r;
assert(bus);
assert(path);
assert(interface);
assert(found);
assert(m);
if (streq(path, "/org/freedesktop/login1/session/self")) {
_cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL;
sd_bus_message *message;
const char *name;
message = sd_bus_get_current_message(bus);
if (!message)
return 0;
r = sd_bus_query_sender_creds(message, SD_BUS_CREDS_SESSION|SD_BUS_CREDS_AUGMENT, &creds);
if (r < 0)
return r;
r = sd_bus_creds_get_session(creds, &name);
if (r < 0)
return r;
session = hashmap_get(m->sessions, name);
} else {
_cleanup_free_ char *e = NULL;
const char *p;
p = startswith(path, "/org/freedesktop/login1/session/");
if (!p)
return 0;
e = bus_label_unescape(p);
if (!e)
return -ENOMEM;
session = hashmap_get(m->sessions, e);
}
if (!session)
return 0;
*found = session;
return 1;
}
char *session_bus_path(Session *s) {
_cleanup_free_ char *t = NULL;
assert(s);
t = bus_label_escape(s->id);
if (!t)
return NULL;
return strappend("/org/freedesktop/login1/session/", t);
}
int session_node_enumerator(sd_bus *bus, const char *path, void *userdata, char ***nodes, sd_bus_error *error) {
_cleanup_strv_free_ char **l = NULL;
sd_bus_message *message;
Manager *m = userdata;
Session *session;
Iterator i;
int r;
assert(bus);
assert(path);
assert(nodes);
HASHMAP_FOREACH(session, m->sessions, i) {
char *p;
p = session_bus_path(session);
if (!p)
return -ENOMEM;
r = strv_consume(&l, p);
if (r < 0)
return r;
}
message = sd_bus_get_current_message(bus);
if (message) {
_cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL;
const char *name;
r = sd_bus_query_sender_creds(message, SD_BUS_CREDS_SESSION|SD_BUS_CREDS_AUGMENT, &creds);
if (r >= 0) {
r = sd_bus_creds_get_session(creds, &name);
if (r >= 0) {
session = hashmap_get(m->sessions, name);
if (session) {
r = strv_extend(&l, "/org/freedesktop/login1/session/self");
if (r < 0)
return r;
}
}
}
}
*nodes = l;
l = NULL;
return 1;
}
int session_send_signal(Session *s, bool new_session) {
_cleanup_free_ char *p = NULL;
assert(s);
p = session_bus_path(s);
if (!p)
return -ENOMEM;
return sd_bus_emit_signal(
s->manager->bus,
"/org/freedesktop/login1",
"org.freedesktop.login1.Manager",
new_session ? "SessionNew" : "SessionRemoved",
"so", s->id, p);
}
int session_send_changed(Session *s, const char *properties, ...) {
_cleanup_free_ char *p = NULL;
char **l;
assert(s);
if (!s->started)
return 0;
p = session_bus_path(s);
if (!p)
return -ENOMEM;
l = strv_from_stdarg_alloca(properties);
return sd_bus_emit_properties_changed_strv(s->manager->bus, p, "org.freedesktop.login1.Session", l);
}
int session_send_lock(Session *s, bool lock) {
_cleanup_free_ char *p = NULL;
assert(s);
p = session_bus_path(s);
if (!p)
return -ENOMEM;
return sd_bus_emit_signal(
s->manager->bus,
p,
"org.freedesktop.login1.Session",
lock ? "Lock" : "Unlock",
NULL);
}
int session_send_lock_all(Manager *m, bool lock) {
Session *session;
Iterator i;
int r = 0;
assert(m);
HASHMAP_FOREACH(session, m->sessions, i) {
int k;
k = session_send_lock(session, lock);
if (k < 0)
r = k;
}
return r;
}
int session_send_create_reply(Session *s, sd_bus_error *error) {
_cleanup_(sd_bus_message_unrefp) sd_bus_message *c = NULL;
_cleanup_close_ int fifo_fd = -1;
_cleanup_free_ char *p = NULL;
assert(s);
/* This is called after the session scope and the user service
* were successfully created, and finishes where
* bus_manager_create_session() left off. */
if (!s->create_message)
return 0;
if (!sd_bus_error_is_set(error) && (s->scope_job || s->user->service_job))
return 0;
c = s->create_message;
s->create_message = NULL;
if (error)
return sd_bus_reply_method_error(c, error);
fifo_fd = session_create_fifo(s);
if (fifo_fd < 0)
return fifo_fd;
/* Update the session state file before we notify the client
* about the result. */
session_save(s);
p = session_bus_path(s);
if (!p)
return -ENOMEM;
log_debug("Sending reply about created session: "
"id=%s object_path=%s uid=%u runtime_path=%s "
"session_fd=%d seat=%s vtnr=%u",
s->id,
p,
(uint32_t) s->user->uid,
s->user->runtime_path,
fifo_fd,
s->seat ? s->seat->id : "",
(uint32_t) s->vtnr);
return sd_bus_reply_method_return(
c, "soshusub",
s->id,
p,
s->user->runtime_path,
fifo_fd,
(uint32_t) s->user->uid,
s->seat ? s->seat->id : "",
(uint32_t) s->vtnr,
false);
}