/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2013 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 .
***/
#include
#include "sd-daemon.h"
#include "sd-event.h"
#include "util.h"
#include "strv.h"
#include "macro.h"
#include "def.h"
#include "path-util.h"
#include "missing.h"
#include "set.h"
#include "signal-util.h"
#include "unit-name.h"
#include "sd-bus.h"
#include "bus-error.h"
#include "bus-label.h"
#include "bus-message.h"
#include "bus-util.h"
#include "bus-internal.h"
static int name_owner_change_callback(sd_bus_message *m, void *userdata, sd_bus_error *ret_error) {
sd_event *e = userdata;
assert(m);
assert(e);
sd_bus_close(sd_bus_message_get_bus(m));
sd_event_exit(e, 0);
return 1;
}
int bus_async_unregister_and_exit(sd_event *e, sd_bus *bus, const char *name) {
_cleanup_free_ char *match = NULL;
const char *unique;
int r;
assert(e);
assert(bus);
assert(name);
/* We unregister the name here and then wait for the
* NameOwnerChanged signal for this event to arrive before we
* quit. We do this in order to make sure that any queued
* requests are still processed before we really exit. */
r = sd_bus_get_unique_name(bus, &unique);
if (r < 0)
return r;
r = asprintf(&match,
"sender='org.freedesktop.DBus',"
"type='signal',"
"interface='org.freedesktop.DBus',"
"member='NameOwnerChanged',"
"path='/org/freedesktop/DBus',"
"arg0='%s',"
"arg1='%s',"
"arg2=''", name, unique);
if (r < 0)
return -ENOMEM;
r = sd_bus_add_match(bus, NULL, match, name_owner_change_callback, e);
if (r < 0)
return r;
r = sd_bus_release_name(bus, name);
if (r < 0)
return r;
return 0;
}
int bus_event_loop_with_idle(
sd_event *e,
sd_bus *bus,
const char *name,
usec_t timeout,
check_idle_t check_idle,
void *userdata) {
bool exiting = false;
int r, code;
assert(e);
assert(bus);
assert(name);
for (;;) {
bool idle;
r = sd_event_get_state(e);
if (r < 0)
return r;
if (r == SD_EVENT_FINISHED)
break;
if (check_idle)
idle = check_idle(userdata);
else
idle = true;
r = sd_event_run(e, exiting || !idle ? (uint64_t) -1 : timeout);
if (r < 0)
return r;
if (r == 0 && !exiting && idle) {
r = sd_bus_try_close(bus);
if (r == -EBUSY)
continue;
/* Fallback for dbus1 connections: we
* unregister the name and wait for the
* response to come through for it */
if (r == -EOPNOTSUPP) {
/* Inform the service manager that we
* are going down, so that it will
* queue all further start requests,
* instead of assuming we are already
* running. */
sd_notify(false, "STOPPING=1");
r = bus_async_unregister_and_exit(e, bus, name);
if (r < 0)
return r;
exiting = true;
continue;
}
if (r < 0)
return r;
sd_event_exit(e, 0);
break;
}
}
r = sd_event_get_exit_code(e, &code);
if (r < 0)
return r;
return code;
}
int bus_name_has_owner(sd_bus *c, const char *name, sd_bus_error *error) {
_cleanup_bus_message_unref_ sd_bus_message *rep = NULL;
int r, has_owner = 0;
assert(c);
assert(name);
r = sd_bus_call_method(c,
"org.freedesktop.DBus",
"/org/freedesktop/dbus",
"org.freedesktop.DBus",
"NameHasOwner",
error,
&rep,
"s",
name);
if (r < 0)
return r;
r = sd_bus_message_read_basic(rep, 'b', &has_owner);
if (r < 0)
return sd_bus_error_set_errno(error, r);
return has_owner;
}
static int check_good_user(sd_bus_message *m, uid_t good_user) {
_cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL;
uid_t sender_uid;
int r;
assert(m);
if (good_user == UID_INVALID)
return 0;
r = sd_bus_query_sender_creds(m, SD_BUS_CREDS_EUID, &creds);
if (r < 0)
return r;
/* Don't trust augmented credentials for authorization */
assert_return((sd_bus_creds_get_augmented_mask(creds) & SD_BUS_CREDS_EUID) == 0, -EPERM);
r = sd_bus_creds_get_euid(creds, &sender_uid);
if (r < 0)
return r;
return sender_uid == good_user;
}
int bus_test_polkit(
sd_bus_message *call,
int capability,
const char *action,
const char **details,
uid_t good_user,
bool *_challenge,
sd_bus_error *e) {
int r;
assert(call);
assert(action);
/* Tests non-interactively! */
r = check_good_user(call, good_user);
if (r != 0)
return r;
r = sd_bus_query_sender_privilege(call, capability);
if (r < 0)
return r;
else if (r > 0)
return 1;
#ifdef ENABLE_POLKIT
else {
_cleanup_bus_message_unref_ sd_bus_message *request = NULL;
_cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
int authorized = false, challenge = false;
const char *sender, **k, **v;
sender = sd_bus_message_get_sender(call);
if (!sender)
return -EBADMSG;
r = sd_bus_message_new_method_call(
call->bus,
&request,
"org.freedesktop.PolicyKit1",
"/org/freedesktop/PolicyKit1/Authority",
"org.freedesktop.PolicyKit1.Authority",
"CheckAuthorization");
if (r < 0)
return r;
r = sd_bus_message_append(
request,
"(sa{sv})s",
"system-bus-name", 1, "name", "s", sender,
action);
if (r < 0)
return r;
r = sd_bus_message_open_container(request, 'a', "{ss}");
if (r < 0)
return r;
STRV_FOREACH_PAIR(k, v, details) {
r = sd_bus_message_append(request, "{ss}", *k, *v);
if (r < 0)
return r;
}
r = sd_bus_message_close_container(request);
if (r < 0)
return r;
r = sd_bus_message_append(request, "us", 0, NULL);
if (r < 0)
return r;
r = sd_bus_call(call->bus, request, 0, e, &reply);
if (r < 0) {
/* Treat no PK available as access denied */
if (sd_bus_error_has_name(e, SD_BUS_ERROR_SERVICE_UNKNOWN)) {
sd_bus_error_free(e);
return -EACCES;
}
return r;
}
r = sd_bus_message_enter_container(reply, 'r', "bba{ss}");
if (r < 0)
return r;
r = sd_bus_message_read(reply, "bb", &authorized, &challenge);
if (r < 0)
return r;
if (authorized)
return 1;
if (_challenge) {
*_challenge = challenge;
return 0;
}
}
#endif
return -EACCES;
}
#ifdef ENABLE_POLKIT
typedef struct AsyncPolkitQuery {
sd_bus_message *request, *reply;
sd_bus_message_handler_t callback;
void *userdata;
sd_bus_slot *slot;
Hashmap *registry;
} AsyncPolkitQuery;
static void async_polkit_query_free(AsyncPolkitQuery *q) {
if (!q)
return;
sd_bus_slot_unref(q->slot);
if (q->registry && q->request)
hashmap_remove(q->registry, q->request);
sd_bus_message_unref(q->request);
sd_bus_message_unref(q->reply);
free(q);
}
static int async_polkit_callback(sd_bus_message *reply, void *userdata, sd_bus_error *error) {
_cleanup_bus_error_free_ sd_bus_error error_buffer = SD_BUS_ERROR_NULL;
AsyncPolkitQuery *q = userdata;
int r;
assert(reply);
assert(q);
q->slot = sd_bus_slot_unref(q->slot);
q->reply = sd_bus_message_ref(reply);
r = sd_bus_message_rewind(q->request, true);
if (r < 0) {
r = sd_bus_reply_method_errno(q->request, r, NULL);
goto finish;
}
r = q->callback(q->request, q->userdata, &error_buffer);
r = bus_maybe_reply_error(q->request, r, &error_buffer);
finish:
async_polkit_query_free(q);
return r;
}
#endif
int bus_verify_polkit_async(
sd_bus_message *call,
int capability,
const char *action,
const char **details,
bool interactive,
uid_t good_user,
Hashmap **registry,
sd_bus_error *error) {
#ifdef ENABLE_POLKIT
_cleanup_bus_message_unref_ sd_bus_message *pk = NULL;
AsyncPolkitQuery *q;
const char *sender, **k, **v;
sd_bus_message_handler_t callback;
void *userdata;
int c;
#endif
int r;
assert(call);
assert(action);
assert(registry);
r = check_good_user(call, good_user);
if (r != 0)
return r;
#ifdef ENABLE_POLKIT
q = hashmap_get(*registry, call);
if (q) {
int authorized, challenge;
/* This is the second invocation of this function, and
* there's already a response from polkit, let's
* process it */
assert(q->reply);
if (sd_bus_message_is_method_error(q->reply, NULL)) {
const sd_bus_error *e;
/* Copy error from polkit reply */
e = sd_bus_message_get_error(q->reply);
sd_bus_error_copy(error, e);
/* Treat no PK available as access denied */
if (sd_bus_error_has_name(e, SD_BUS_ERROR_SERVICE_UNKNOWN))
return -EACCES;
return -sd_bus_error_get_errno(e);
}
r = sd_bus_message_enter_container(q->reply, 'r', "bba{ss}");
if (r >= 0)
r = sd_bus_message_read(q->reply, "bb", &authorized, &challenge);
if (r < 0)
return r;
if (authorized)
return 1;
if (challenge)
return sd_bus_error_set(error, SD_BUS_ERROR_INTERACTIVE_AUTHORIZATION_REQUIRED, "Interactive authentication required.");
return -EACCES;
}
#endif
r = sd_bus_query_sender_privilege(call, capability);
if (r < 0)
return r;
else if (r > 0)
return 1;
#ifdef ENABLE_POLKIT
if (sd_bus_get_current_message(call->bus) != call)
return -EINVAL;
callback = sd_bus_get_current_handler(call->bus);
if (!callback)
return -EINVAL;
userdata = sd_bus_get_current_userdata(call->bus);
sender = sd_bus_message_get_sender(call);
if (!sender)
return -EBADMSG;
c = sd_bus_message_get_allow_interactive_authorization(call);
if (c < 0)
return c;
if (c > 0)
interactive = true;
r = hashmap_ensure_allocated(registry, NULL);
if (r < 0)
return r;
r = sd_bus_message_new_method_call(
call->bus,
&pk,
"org.freedesktop.PolicyKit1",
"/org/freedesktop/PolicyKit1/Authority",
"org.freedesktop.PolicyKit1.Authority",
"CheckAuthorization");
if (r < 0)
return r;
r = sd_bus_message_append(
pk,
"(sa{sv})s",
"system-bus-name", 1, "name", "s", sender,
action);
if (r < 0)
return r;
r = sd_bus_message_open_container(pk, 'a', "{ss}");
if (r < 0)
return r;
STRV_FOREACH_PAIR(k, v, details) {
r = sd_bus_message_append(pk, "{ss}", *k, *v);
if (r < 0)
return r;
}
r = sd_bus_message_close_container(pk);
if (r < 0)
return r;
r = sd_bus_message_append(pk, "us", !!interactive, NULL);
if (r < 0)
return r;
q = new0(AsyncPolkitQuery, 1);
if (!q)
return -ENOMEM;
q->request = sd_bus_message_ref(call);
q->callback = callback;
q->userdata = userdata;
r = hashmap_put(*registry, call, q);
if (r < 0) {
async_polkit_query_free(q);
return r;
}
q->registry = *registry;
r = sd_bus_call_async(call->bus, &q->slot, pk, async_polkit_callback, q, 0);
if (r < 0) {
async_polkit_query_free(q);
return r;
}
return 0;
#endif
return -EACCES;
}
void bus_verify_polkit_async_registry_free(Hashmap *registry) {
#ifdef ENABLE_POLKIT
AsyncPolkitQuery *q;
while ((q = hashmap_steal_first(registry)))
async_polkit_query_free(q);
hashmap_free(registry);
#endif
}
int bus_check_peercred(sd_bus *c) {
struct ucred ucred;
socklen_t l;
int fd;
assert(c);
fd = sd_bus_get_fd(c);
if (fd < 0)
return fd;
l = sizeof(struct ucred);
if (getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &ucred, &l) < 0)
return -errno;
if (l != sizeof(struct ucred))
return -E2BIG;
if (ucred.uid != 0 && ucred.uid != geteuid())
return -EPERM;
return 1;
}
int bus_open_system_systemd(sd_bus **_bus) {
_cleanup_bus_unref_ sd_bus *bus = NULL;
int r;
assert(_bus);
if (geteuid() != 0)
return sd_bus_open_system(_bus);
/* If we are root and kdbus is not available, then let's talk
* directly to the system instance, instead of going via the
* bus */
r = sd_bus_new(&bus);
if (r < 0)
return r;
r = sd_bus_set_address(bus, KERNEL_SYSTEM_BUS_ADDRESS);
if (r < 0)
return r;
bus->bus_client = true;
r = sd_bus_start(bus);
if (r >= 0) {
*_bus = bus;
bus = NULL;
return 0;
}
bus = sd_bus_unref(bus);
r = sd_bus_new(&bus);
if (r < 0)
return r;
r = sd_bus_set_address(bus, "unix:path=/run/systemd/private");
if (r < 0)
return r;
r = sd_bus_start(bus);
if (r < 0)
return sd_bus_open_system(_bus);
r = bus_check_peercred(bus);
if (r < 0)
return r;
*_bus = bus;
bus = NULL;
return 0;
}
int bus_open_user_systemd(sd_bus **_bus) {
_cleanup_bus_unref_ sd_bus *bus = NULL;
_cleanup_free_ char *ee = NULL;
const char *e;
int r;
/* Try via kdbus first, and then directly */
assert(_bus);
r = sd_bus_new(&bus);
if (r < 0)
return r;
if (asprintf(&bus->address, KERNEL_USER_BUS_ADDRESS_FMT, getuid()) < 0)
return -ENOMEM;
bus->bus_client = true;
r = sd_bus_start(bus);
if (r >= 0) {
*_bus = bus;
bus = NULL;
return 0;
}
bus = sd_bus_unref(bus);
e = secure_getenv("XDG_RUNTIME_DIR");
if (!e)
return sd_bus_open_user(_bus);
ee = bus_address_escape(e);
if (!ee)
return -ENOMEM;
r = sd_bus_new(&bus);
if (r < 0)
return r;
bus->address = strjoin("unix:path=", ee, "/systemd/private", NULL);
if (!bus->address)
return -ENOMEM;
r = sd_bus_start(bus);
if (r < 0)
return sd_bus_open_user(_bus);
r = bus_check_peercred(bus);
if (r < 0)
return r;
*_bus = bus;
bus = NULL;
return 0;
}
int bus_print_property(const char *name, sd_bus_message *property, bool all) {
char type;
const char *contents;
int r;
assert(name);
assert(property);
r = sd_bus_message_peek_type(property, &type, &contents);
if (r < 0)
return r;
switch (type) {
case SD_BUS_TYPE_STRING: {
const char *s;
r = sd_bus_message_read_basic(property, type, &s);
if (r < 0)
return r;
if (all || !isempty(s)) {
_cleanup_free_ char *escaped = NULL;
escaped = xescape(s, "\n");
if (!escaped)
return -ENOMEM;
printf("%s=%s\n", name, escaped);
}
return 1;
}
case SD_BUS_TYPE_BOOLEAN: {
int b;
r = sd_bus_message_read_basic(property, type, &b);
if (r < 0)
return r;
printf("%s=%s\n", name, yes_no(b));
return 1;
}
case SD_BUS_TYPE_UINT64: {
uint64_t u;
r = sd_bus_message_read_basic(property, type, &u);
if (r < 0)
return r;
/* Yes, heuristics! But we can change this check
* should it turn out to not be sufficient */
if (endswith(name, "Timestamp")) {
char timestamp[FORMAT_TIMESTAMP_MAX], *t;
t = format_timestamp(timestamp, sizeof(timestamp), u);
if (t || all)
printf("%s=%s\n", name, strempty(t));
} else if (strstr(name, "USec")) {
char timespan[FORMAT_TIMESPAN_MAX];
printf("%s=%s\n", name, format_timespan(timespan, sizeof(timespan), u, 0));
} else
printf("%s=%llu\n", name, (unsigned long long) u);
return 1;
}
case SD_BUS_TYPE_INT64: {
int64_t i;
r = sd_bus_message_read_basic(property, type, &i);
if (r < 0)
return r;
printf("%s=%lld\n", name, (long long) i);
return 1;
}
case SD_BUS_TYPE_UINT32: {
uint32_t u;
r = sd_bus_message_read_basic(property, type, &u);
if (r < 0)
return r;
if (strstr(name, "UMask") || strstr(name, "Mode"))
printf("%s=%04o\n", name, u);
else
printf("%s=%u\n", name, (unsigned) u);
return 1;
}
case SD_BUS_TYPE_INT32: {
int32_t i;
r = sd_bus_message_read_basic(property, type, &i);
if (r < 0)
return r;
printf("%s=%i\n", name, (int) i);
return 1;
}
case SD_BUS_TYPE_DOUBLE: {
double d;
r = sd_bus_message_read_basic(property, type, &d);
if (r < 0)
return r;
printf("%s=%g\n", name, d);
return 1;
}
case SD_BUS_TYPE_ARRAY:
if (streq(contents, "s")) {
bool first = true;
const char *str;
r = sd_bus_message_enter_container(property, SD_BUS_TYPE_ARRAY, contents);
if (r < 0)
return r;
while((r = sd_bus_message_read_basic(property, SD_BUS_TYPE_STRING, &str)) > 0) {
_cleanup_free_ char *escaped = NULL;
if (first)
printf("%s=", name);
escaped = xescape(str, "\n ");
if (!escaped)
return -ENOMEM;
printf("%s%s", first ? "" : " ", escaped);
first = false;
}
if (r < 0)
return r;
if (first && all)
printf("%s=", name);
if (!first || all)
puts("");
r = sd_bus_message_exit_container(property);
if (r < 0)
return r;
return 1;
} else if (streq(contents, "y")) {
const uint8_t *u;
size_t n;
r = sd_bus_message_read_array(property, SD_BUS_TYPE_BYTE, (const void**) &u, &n);
if (r < 0)
return r;
if (all || n > 0) {
unsigned int i;
printf("%s=", name);
for (i = 0; i < n; i++)
printf("%02x", u[i]);
puts("");
}
return 1;
} else if (streq(contents, "u")) {
uint32_t *u;
size_t n;
r = sd_bus_message_read_array(property, SD_BUS_TYPE_UINT32, (const void**) &u, &n);
if (r < 0)
return r;
if (all || n > 0) {
unsigned int i;
printf("%s=", name);
for (i = 0; i < n; i++)
printf("%08x", u[i]);
puts("");
}
return 1;
}
break;
}
return 0;
}
int bus_print_all_properties(sd_bus *bus, const char *dest, const char *path, char **filter, bool all) {
_cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
_cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
int r;
assert(bus);
assert(path);
r = sd_bus_call_method(bus,
dest,
path,
"org.freedesktop.DBus.Properties",
"GetAll",
&error,
&reply,
"s", "");
if (r < 0)
return r;
r = sd_bus_message_enter_container(reply, SD_BUS_TYPE_ARRAY, "{sv}");
if (r < 0)
return r;
while ((r = sd_bus_message_enter_container(reply, SD_BUS_TYPE_DICT_ENTRY, "sv")) > 0) {
const char *name;
const char *contents;
r = sd_bus_message_read_basic(reply, SD_BUS_TYPE_STRING, &name);
if (r < 0)
return r;
if (!filter || strv_find(filter, name)) {
r = sd_bus_message_peek_type(reply, NULL, &contents);
if (r < 0)
return r;
r = sd_bus_message_enter_container(reply, SD_BUS_TYPE_VARIANT, contents);
if (r < 0)
return r;
r = bus_print_property(name, reply, all);
if (r < 0)
return r;
if (r == 0) {
if (all)
printf("%s=[unprintable]\n", name);
/* skip what we didn't read */
r = sd_bus_message_skip(reply, contents);
if (r < 0)
return r;
}
r = sd_bus_message_exit_container(reply);
if (r < 0)
return r;
} else {
r = sd_bus_message_skip(reply, "v");
if (r < 0)
return r;
}
r = sd_bus_message_exit_container(reply);
if (r < 0)
return r;
}
if (r < 0)
return r;
r = sd_bus_message_exit_container(reply);
if (r < 0)
return r;
return 0;
}
int bus_map_id128(sd_bus *bus, const char *member, sd_bus_message *m, sd_bus_error *error, void *userdata) {
sd_id128_t *p = userdata;
const void *v;
size_t n;
int r;
r = sd_bus_message_read_array(m, SD_BUS_TYPE_BYTE, &v, &n);
if (r < 0)
return r;
if (n == 0)
*p = SD_ID128_NULL;
else if (n == 16)
memcpy((*p).bytes, v, n);
else
return -EINVAL;
return 0;
}
static int map_basic(sd_bus *bus, const char *member, sd_bus_message *m, sd_bus_error *error, void *userdata) {
char type;
int r;
r = sd_bus_message_peek_type(m, &type, NULL);
if (r < 0)
return r;
switch (type) {
case SD_BUS_TYPE_STRING: {
const char *s;
char **p = userdata;
r = sd_bus_message_read_basic(m, type, &s);
if (r < 0)
break;
if (isempty(s))
break;
r = free_and_strdup(p, s);
break;
}
case SD_BUS_TYPE_ARRAY: {
_cleanup_strv_free_ char **l = NULL;
char ***p = userdata;
r = bus_message_read_strv_extend(m, &l);
if (r < 0)
break;
strv_free(*p);
*p = l;
l = NULL;
break;
}
case SD_BUS_TYPE_BOOLEAN: {
unsigned b;
bool *p = userdata;
r = sd_bus_message_read_basic(m, type, &b);
if (r < 0)
break;
*p = b;
break;
}
case SD_BUS_TYPE_UINT32: {
uint64_t u;
uint32_t *p = userdata;
r = sd_bus_message_read_basic(m, type, &u);
if (r < 0)
break;
*p = u;
break;
}
case SD_BUS_TYPE_UINT64: {
uint64_t t;
uint64_t *p = userdata;
r = sd_bus_message_read_basic(m, type, &t);
if (r < 0)
break;
*p = t;
break;
}
default:
break;
}
return r;
}
int bus_message_map_all_properties(
sd_bus_message *m,
const struct bus_properties_map *map,
void *userdata) {
_cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
int r;
assert(m);
assert(map);
r = sd_bus_message_enter_container(m, SD_BUS_TYPE_ARRAY, "{sv}");
if (r < 0)
return r;
while ((r = sd_bus_message_enter_container(m, SD_BUS_TYPE_DICT_ENTRY, "sv")) > 0) {
const struct bus_properties_map *prop;
const char *member;
const char *contents;
void *v;
unsigned i;
r = sd_bus_message_read_basic(m, SD_BUS_TYPE_STRING, &member);
if (r < 0)
return r;
for (i = 0, prop = NULL; map[i].member; i++)
if (streq(map[i].member, member)) {
prop = &map[i];
break;
}
if (prop) {
r = sd_bus_message_peek_type(m, NULL, &contents);
if (r < 0)
return r;
r = sd_bus_message_enter_container(m, SD_BUS_TYPE_VARIANT, contents);
if (r < 0)
return r;
v = (uint8_t *)userdata + prop->offset;
if (map[i].set)
r = prop->set(sd_bus_message_get_bus(m), member, m, &error, v);
else
r = map_basic(sd_bus_message_get_bus(m), member, m, &error, v);
if (r < 0)
return r;
r = sd_bus_message_exit_container(m);
if (r < 0)
return r;
} else {
r = sd_bus_message_skip(m, "v");
if (r < 0)
return r;
}
r = sd_bus_message_exit_container(m);
if (r < 0)
return r;
}
if (r < 0)
return r;
return sd_bus_message_exit_container(m);
}
int bus_message_map_properties_changed(
sd_bus_message *m,
const struct bus_properties_map *map,
void *userdata) {
const char *member;
int r, invalidated, i;
assert(m);
assert(map);
r = bus_message_map_all_properties(m, map, userdata);
if (r < 0)
return r;
r = sd_bus_message_enter_container(m, SD_BUS_TYPE_ARRAY, "s");
if (r < 0)
return r;
invalidated = 0;
while ((r = sd_bus_message_read_basic(m, SD_BUS_TYPE_STRING, &member)) > 0)
for (i = 0; map[i].member; i++)
if (streq(map[i].member, member)) {
++invalidated;
break;
}
if (r < 0)
return r;
r = sd_bus_message_exit_container(m);
if (r < 0)
return r;
return invalidated;
}
int bus_map_all_properties(
sd_bus *bus,
const char *destination,
const char *path,
const struct bus_properties_map *map,
void *userdata) {
_cleanup_bus_message_unref_ sd_bus_message *m = NULL;
_cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
int r;
assert(bus);
assert(destination);
assert(path);
assert(map);
r = sd_bus_call_method(
bus,
destination,
path,
"org.freedesktop.DBus.Properties",
"GetAll",
&error,
&m,
"s", "");
if (r < 0)
return r;
return bus_message_map_all_properties(m, map, userdata);
}
int bus_open_transport(BusTransport transport, const char *host, bool user, sd_bus **bus) {
int r;
assert(transport >= 0);
assert(transport < _BUS_TRANSPORT_MAX);
assert(bus);
assert_return((transport == BUS_TRANSPORT_LOCAL) == !host, -EINVAL);
assert_return(transport == BUS_TRANSPORT_LOCAL || !user, -EOPNOTSUPP);
switch (transport) {
case BUS_TRANSPORT_LOCAL:
if (user)
r = sd_bus_default_user(bus);
else
r = sd_bus_default_system(bus);
break;
case BUS_TRANSPORT_REMOTE:
r = sd_bus_open_system_remote(bus, host);
break;
case BUS_TRANSPORT_MACHINE:
r = sd_bus_open_system_machine(bus, host);
break;
default:
assert_not_reached("Hmm, unknown transport type.");
}
return r;
}
int bus_open_transport_systemd(BusTransport transport, const char *host, bool user, sd_bus **bus) {
int r;
assert(transport >= 0);
assert(transport < _BUS_TRANSPORT_MAX);
assert(bus);
assert_return((transport == BUS_TRANSPORT_LOCAL) == !host, -EINVAL);
assert_return(transport == BUS_TRANSPORT_LOCAL || !user, -EOPNOTSUPP);
switch (transport) {
case BUS_TRANSPORT_LOCAL:
if (user)
r = bus_open_user_systemd(bus);
else
r = bus_open_system_systemd(bus);
break;
case BUS_TRANSPORT_REMOTE:
r = sd_bus_open_system_remote(bus, host);
break;
case BUS_TRANSPORT_MACHINE:
r = sd_bus_open_system_machine(bus, host);
break;
default:
assert_not_reached("Hmm, unknown transport type.");
}
return r;
}
int bus_property_get_bool(
sd_bus *bus,
const char *path,
const char *interface,
const char *property,
sd_bus_message *reply,
void *userdata,
sd_bus_error *error) {
int b = *(bool*) userdata;
return sd_bus_message_append_basic(reply, 'b', &b);
}
#if __SIZEOF_SIZE_T__ != 8
int bus_property_get_size(
sd_bus *bus,
const char *path,
const char *interface,
const char *property,
sd_bus_message *reply,
void *userdata,
sd_bus_error *error) {
uint64_t sz = *(size_t*) userdata;
return sd_bus_message_append_basic(reply, 't', &sz);
}
#endif
#if __SIZEOF_LONG__ != 8
int bus_property_get_long(
sd_bus *bus,
const char *path,
const char *interface,
const char *property,
sd_bus_message *reply,
void *userdata,
sd_bus_error *error) {
int64_t l = *(long*) userdata;
return sd_bus_message_append_basic(reply, 'x', &l);
}
int bus_property_get_ulong(
sd_bus *bus,
const char *path,
const char *interface,
const char *property,
sd_bus_message *reply,
void *userdata,
sd_bus_error *error) {
uint64_t ul = *(unsigned long*) userdata;
return sd_bus_message_append_basic(reply, 't', &ul);
}
#endif
int bus_log_parse_error(int r) {
return log_error_errno(r, "Failed to parse bus message: %m");
}
int bus_log_create_error(int r) {
return log_error_errno(r, "Failed to create bus message: %m");
}
int bus_parse_unit_info(sd_bus_message *message, UnitInfo *u) {
assert(message);
assert(u);
u->machine = NULL;
return sd_bus_message_read(
message,
"(ssssssouso)",
&u->id,
&u->description,
&u->load_state,
&u->active_state,
&u->sub_state,
&u->following,
&u->unit_path,
&u->job_id,
&u->job_type,
&u->job_path);
}
int bus_append_unit_property_assignment(sd_bus_message *m, const char *assignment) {
const char *eq, *field;
int r;
assert(m);
assert(assignment);
eq = strchr(assignment, '=');
if (!eq) {
log_error("Not an assignment: %s", assignment);
return -EINVAL;
}
field = strndupa(assignment, eq - assignment);
eq ++;
if (streq(field, "CPUQuota")) {
if (isempty(eq)) {
r = sd_bus_message_append_basic(m, SD_BUS_TYPE_STRING, "CPUQuotaPerSecUSec");
if (r < 0)
return bus_log_create_error(r);
r = sd_bus_message_append(m, "v", "t", USEC_INFINITY);
} else if (endswith(eq, "%")) {
double percent;
if (sscanf(eq, "%lf%%", &percent) != 1 || percent <= 0) {
log_error("CPU quota '%s' invalid.", eq);
return -EINVAL;
}
r = sd_bus_message_append_basic(m, SD_BUS_TYPE_STRING, "CPUQuotaPerSecUSec");
if (r < 0)
return bus_log_create_error(r);
r = sd_bus_message_append(m, "v", "t", (usec_t) percent * USEC_PER_SEC / 100);
} else {
log_error("CPU quota needs to be in percent.");
return -EINVAL;
}
if (r < 0)
return bus_log_create_error(r);
return 0;
}
r = sd_bus_message_append_basic(m, SD_BUS_TYPE_STRING, field);
if (r < 0)
return bus_log_create_error(r);
if (STR_IN_SET(field,
"CPUAccounting", "MemoryAccounting", "BlockIOAccounting",
"SendSIGHUP", "SendSIGKILL", "WakeSystem", "DefaultDependencies",
"IgnoreSIGPIPE", "TTYVHangup", "TTYReset", "RemainAfterExit")) {
r = parse_boolean(eq);
if (r < 0) {
log_error("Failed to parse boolean assignment %s.", assignment);
return -EINVAL;
}
r = sd_bus_message_append(m, "v", "b", r);
} else if (streq(field, "MemoryLimit")) {
uint64_t bytes;
r = parse_size(eq, 1024, &bytes);
if (r < 0) {
log_error("Failed to parse bytes specification %s", assignment);
return -EINVAL;
}
r = sd_bus_message_append(m, "v", "t", bytes);
} else if (STR_IN_SET(field, "CPUShares", "BlockIOWeight")) {
uint64_t u;
r = safe_atou64(eq, &u);
if (r < 0) {
log_error("Failed to parse %s value %s.", field, eq);
return -EINVAL;
}
r = sd_bus_message_append(m, "v", "t", u);
} else if (STR_IN_SET(field,
"User", "Group", "DevicePolicy", "KillMode",
"UtmpIdentifier", "UtmpMode", "PAMName", "TTYPath",
"StandardInput", "StandardOutput", "StandardError",
"Description", "Slice", "Type"))
r = sd_bus_message_append(m, "v", "s", eq);
else if (streq(field, "DeviceAllow")) {
if (isempty(eq))
r = sd_bus_message_append(m, "v", "a(ss)", 0);
else {
const char *path, *rwm, *e;
e = strchr(eq, ' ');
if (e) {
path = strndupa(eq, e - eq);
rwm = e+1;
} else {
path = eq;
rwm = "";
}
if (!path_startswith(path, "/dev")) {
log_error("%s is not a device file in /dev.", path);
return -EINVAL;
}
r = sd_bus_message_append(m, "v", "a(ss)", 1, path, rwm);
}
} else if (STR_IN_SET(field, "BlockIOReadBandwidth", "BlockIOWriteBandwidth")) {
if (isempty(eq))
r = sd_bus_message_append(m, "v", "a(st)", 0);
else {
const char *path, *bandwidth, *e;
uint64_t bytes;
e = strchr(eq, ' ');
if (e) {
path = strndupa(eq, e - eq);
bandwidth = e+1;
} else {
log_error("Failed to parse %s value %s.", field, eq);
return -EINVAL;
}
if (!path_startswith(path, "/dev")) {
log_error("%s is not a device file in /dev.", path);
return -EINVAL;
}
r = parse_size(bandwidth, 1000, &bytes);
if (r < 0) {
log_error("Failed to parse byte value %s.", bandwidth);
return -EINVAL;
}
r = sd_bus_message_append(m, "v", "a(st)", 1, path, bytes);
}
} else if (streq(field, "BlockIODeviceWeight")) {
if (isempty(eq))
r = sd_bus_message_append(m, "v", "a(st)", 0);
else {
const char *path, *weight, *e;
uint64_t u;
e = strchr(eq, ' ');
if (e) {
path = strndupa(eq, e - eq);
weight = e+1;
} else {
log_error("Failed to parse %s value %s.", field, eq);
return -EINVAL;
}
if (!path_startswith(path, "/dev")) {
log_error("%s is not a device file in /dev.", path);
return -EINVAL;
}
r = safe_atou64(weight, &u);
if (r < 0) {
log_error("Failed to parse %s value %s.", field, weight);
return -EINVAL;
}
r = sd_bus_message_append(m, "v", "a(st)", path, u);
}
} else if (rlimit_from_string(field) >= 0) {
uint64_t rl;
if (streq(eq, "infinity"))
rl = (uint64_t) -1;
else {
r = safe_atou64(eq, &rl);
if (r < 0) {
log_error("Invalid resource limit: %s", eq);
return -EINVAL;
}
}
r = sd_bus_message_append(m, "v", "t", rl);
} else if (streq(field, "Nice")) {
int32_t i;
r = safe_atoi32(eq, &i);
if (r < 0) {
log_error("Failed to parse %s value %s.", field, eq);
return -EINVAL;
}
r = sd_bus_message_append(m, "v", "i", i);
} else if (streq(field, "Environment")) {
r = sd_bus_message_append(m, "v", "as", 1, eq);
} else if (streq(field, "KillSignal")) {
int sig;
sig = signal_from_string_try_harder(eq);
if (sig < 0) {
log_error("Failed to parse %s value %s.", field, eq);
return -EINVAL;
}
r = sd_bus_message_append(m, "v", "i", sig);
} else if (streq(field, "AccuracySec")) {
usec_t u;
r = parse_sec(eq, &u);
if (r < 0) {
log_error("Failed to parse %s value %s", field, eq);
return -EINVAL;
}
r = sd_bus_message_append(m, "v", "t", u);
} else {
log_error("Unknown assignment %s.", assignment);
return -EINVAL;
}
if (r < 0)
return bus_log_create_error(r);
return 0;
}
typedef struct BusWaitForJobs {
sd_bus *bus;
Set *jobs;
char *name;
char *result;
sd_bus_slot *slot_job_removed;
sd_bus_slot *slot_disconnected;
} BusWaitForJobs;
static int match_disconnected(sd_bus_message *m, void *userdata, sd_bus_error *error) {
assert(m);
log_error("Warning! D-Bus connection terminated.");
sd_bus_close(sd_bus_message_get_bus(m));
return 0;
}
static int match_job_removed(sd_bus_message *m, void *userdata, sd_bus_error *error) {
const char *path, *unit, *result;
BusWaitForJobs *d = userdata;
uint32_t id;
char *found;
int r;
assert(m);
assert(d);
r = sd_bus_message_read(m, "uoss", &id, &path, &unit, &result);
if (r < 0) {
bus_log_parse_error(r);
return 0;
}
found = set_remove(d->jobs, (char*) path);
if (!found)
return 0;
free(found);
if (!isempty(result))
d->result = strdup(result);
if (!isempty(unit))
d->name = strdup(unit);
return 0;
}
void bus_wait_for_jobs_free(BusWaitForJobs *d) {
if (!d)
return;
set_free_free(d->jobs);
sd_bus_slot_unref(d->slot_disconnected);
sd_bus_slot_unref(d->slot_job_removed);
sd_bus_unref(d->bus);
free(d->name);
free(d->result);
free(d);
}
int bus_wait_for_jobs_new(sd_bus *bus, BusWaitForJobs **ret) {
_cleanup_(bus_wait_for_jobs_freep) BusWaitForJobs *d = NULL;
int r;
assert(bus);
assert(ret);
d = new0(BusWaitForJobs, 1);
if (!d)
return -ENOMEM;
d->bus = sd_bus_ref(bus);
/* When we are a bus client we match by sender. Direct
* connections OTOH have no initialized sender field, and
* hence we ignore the sender then */
r = sd_bus_add_match(
bus,
&d->slot_job_removed,
bus->bus_client ?
"type='signal',"
"sender='org.freedesktop.systemd1',"
"interface='org.freedesktop.systemd1.Manager',"
"member='JobRemoved',"
"path='/org/freedesktop/systemd1'" :
"type='signal',"
"interface='org.freedesktop.systemd1.Manager',"
"member='JobRemoved',"
"path='/org/freedesktop/systemd1'",
match_job_removed, d);
if (r < 0)
return r;
r = sd_bus_add_match(
bus,
&d->slot_disconnected,
"type='signal',"
"sender='org.freedesktop.DBus.Local',"
"interface='org.freedesktop.DBus.Local',"
"member='Disconnected'",
match_disconnected, d);
if (r < 0)
return r;
*ret = d;
d = NULL;
return 0;
}
static int bus_process_wait(sd_bus *bus) {
int r;
for (;;) {
r = sd_bus_process(bus, NULL);
if (r < 0)
return r;
if (r > 0)
return 0;
r = sd_bus_wait(bus, (uint64_t) -1);
if (r < 0)
return r;
}
}
static int bus_job_get_service_result(BusWaitForJobs *d, char **result) {
_cleanup_free_ char *dbus_path = NULL;
assert(d);
assert(d->name);
assert(result);
dbus_path = unit_dbus_path_from_name(d->name);
if (!dbus_path)
return -ENOMEM;
return sd_bus_get_property_string(d->bus,
"org.freedesktop.systemd1",
dbus_path,
"org.freedesktop.systemd1.Service",
"Result",
NULL,
result);
}
static const struct {
const char *result, *explanation;
} explanations [] = {
{ "resources", "a configured resource limit was exceeded" },
{ "timeout", "a timeout was exceeded" },
{ "exit-code", "the control process exited with error code" },
{ "signal", "a fatal signal was delivered to the control process" },
{ "core-dump", "a fatal signal was delivered causing the control process to dump core" },
{ "watchdog", "the service failed to send watchdog ping" },
{ "start-limit", "start of the service was attempted too often" }
};
static void log_job_error_with_service_result(const char* service, const char *result) {
_cleanup_free_ char *service_shell_quoted = NULL;
assert(service);
service_shell_quoted = shell_maybe_quote(service);
if (!isempty(result)) {
unsigned i;
for (i = 0; i < ELEMENTSOF(explanations); ++i)
if (streq(result, explanations[i].result))
break;
if (i < ELEMENTSOF(explanations)) {
log_error("Job for %s failed because %s. See \"systemctl status %s\" and \"journalctl -xe\" for details.\n",
service,
explanations[i].explanation,
strna(service_shell_quoted));
goto finish;
}
}
log_error("Job for %s failed. See \"systemctl status %s\" and \"journalctl -xe\" for details.\n",
service,
strna(service_shell_quoted));
finish:
/* For some results maybe additional explanation is required */
if (streq_ptr(result, "start-limit"))
log_info("To force a start use \"systemctl reset-failed %1$s\" followed by \"systemctl start %1$s\" again.",
strna(service_shell_quoted));
}
static int check_wait_response(BusWaitForJobs *d, bool quiet) {
int r = 0;
assert(d->result);
if (!quiet) {
if (streq(d->result, "canceled"))
log_error("Job for %s canceled.", strna(d->name));
else if (streq(d->result, "timeout"))
log_error("Job for %s timed out.", strna(d->name));
else if (streq(d->result, "dependency"))
log_error("A dependency job for %s failed. See 'journalctl -xe' for details.", strna(d->name));
else if (streq(d->result, "invalid"))
log_error("Job for %s invalid.", strna(d->name));
else if (streq(d->result, "assert"))
log_error("Assertion failed on job for %s.", strna(d->name));
else if (streq(d->result, "unsupported"))
log_error("Operation on or unit type of %s not supported on this system.", strna(d->name));
else if (!streq(d->result, "done") && !streq(d->result, "skipped")) {
if (d->name) {
int q;
_cleanup_free_ char *result = NULL;
q = bus_job_get_service_result(d, &result);
if (q < 0)
log_debug_errno(q, "Failed to get Result property of service %s: %m", d->name);
log_job_error_with_service_result(d->name, result);
} else
log_error("Job failed. See \"journalctl -xe\" for details.");
}
}
if (streq(d->result, "canceled"))
r = -ECANCELED;
else if (streq(d->result, "timeout"))
r = -ETIME;
else if (streq(d->result, "dependency"))
r = -EIO;
else if (streq(d->result, "invalid"))
r = -ENOEXEC;
else if (streq(d->result, "assert"))
r = -EPROTO;
else if (streq(d->result, "unsupported"))
r = -EOPNOTSUPP;
else if (!streq(d->result, "done") && !streq(d->result, "skipped"))
r = -EIO;
return r;
}
int bus_wait_for_jobs(BusWaitForJobs *d, bool quiet) {
int r = 0;
assert(d);
while (!set_isempty(d->jobs)) {
int q;
q = bus_process_wait(d->bus);
if (q < 0)
return log_error_errno(q, "Failed to wait for response: %m");
if (d->result) {
q = check_wait_response(d, quiet);
/* Return the first error as it is most likely to be
* meaningful. */
if (q < 0 && r == 0)
r = q;
log_debug_errno(q, "Got result %s/%m for job %s", strna(d->result), strna(d->name));
}
d->name = mfree(d->name);
d->result = mfree(d->result);
}
return r;
}
int bus_wait_for_jobs_add(BusWaitForJobs *d, const char *path) {
int r;
assert(d);
r = set_ensure_allocated(&d->jobs, &string_hash_ops);
if (r < 0)
return r;
return set_put_strdup(d->jobs, path);
}
int bus_wait_for_jobs_one(BusWaitForJobs *d, const char *path, bool quiet) {
int r;
r = bus_wait_for_jobs_add(d, path);
if (r < 0)
return log_oom();
return bus_wait_for_jobs(d, quiet);
}
int bus_deserialize_and_dump_unit_file_changes(sd_bus_message *m, bool quiet, UnitFileChange **changes, unsigned *n_changes) {
const char *type, *path, *source;
int r;
r = sd_bus_message_enter_container(m, SD_BUS_TYPE_ARRAY, "(sss)");
if (r < 0)
return bus_log_parse_error(r);
while ((r = sd_bus_message_read(m, "(sss)", &type, &path, &source)) > 0) {
if (!quiet) {
if (streq(type, "symlink"))
log_info("Created symlink from %s to %s.", path, source);
else
log_info("Removed symlink %s.", path);
}
r = unit_file_changes_add(changes, n_changes, streq(type, "symlink") ? UNIT_FILE_SYMLINK : UNIT_FILE_UNLINK, path, source);
if (r < 0)
return r;
}
if (r < 0)
return bus_log_parse_error(r);
r = sd_bus_message_exit_container(m);
if (r < 0)
return bus_log_parse_error(r);
return 0;
}
/**
* bus_path_encode_unique() - encode unique object path
* @b: bus connection or NULL
* @prefix: object path prefix
* @sender_id: unique-name of client, or NULL
* @external_id: external ID to be chosen by client, or NULL
* @ret_path: storage for encoded object path pointer
*
* Whenever we provide a bus API that allows clients to create and manage
* server-side objects, we need to provide a unique name for these objects. If
* we let the server choose the name, we suffer from a race condition: If a
* client creates an object asynchronously, it cannot destroy that object until
* it received the method reply. It cannot know the name of the new object,
* thus, it cannot destroy it. Furthermore, it enforces a round-trip.
*
* Therefore, many APIs allow the client to choose the unique name for newly
* created objects. There're two problems to solve, though:
* 1) Object names are usually defined via dbus object paths, which are
* usually globally namespaced. Therefore, multiple clients must be able
* to choose unique object names without interference.
* 2) If multiple libraries share the same bus connection, they must be
* able to choose unique object names without interference.
* The first problem is solved easily by prefixing a name with the
* unique-bus-name of a connection. The server side must enforce this and
* reject any other name. The second problem is solved by providing unique
* suffixes from within sd-bus.
*
* This helper allows clients to create unique object-paths. It uses the
* template '/prefix/sender_id/external_id' and returns the new path in
* @ret_path (must be freed by the caller).
* If @sender_id is NULL, the unique-name of @b is used. If @external_id is
* NULL, this function allocates a unique suffix via @b (by requesting a new
* cookie). If both @sender_id and @external_id are given, @b can be passed as
* NULL.
*
* Returns: 0 on success, negative error code on failure.
*/
int bus_path_encode_unique(sd_bus *b, const char *prefix, const char *sender_id, const char *external_id, char **ret_path) {
_cleanup_free_ char *sender_label = NULL, *external_label = NULL;
char external_buf[DECIMAL_STR_MAX(uint64_t)], *p;
int r;
assert_return(b || (sender_id && external_id), -EINVAL);
assert_return(object_path_is_valid(prefix), -EINVAL);
assert_return(ret_path, -EINVAL);
if (!sender_id) {
r = sd_bus_get_unique_name(b, &sender_id);
if (r < 0)
return r;
}
if (!external_id) {
xsprintf(external_buf, "%"PRIu64, ++b->cookie);
external_id = external_buf;
}
sender_label = bus_label_escape(sender_id);
if (!sender_label)
return -ENOMEM;
external_label = bus_label_escape(external_id);
if (!external_label)
return -ENOMEM;
p = strjoin(prefix, "/", sender_label, "/", external_label, NULL);
if (!p)
return -ENOMEM;
*ret_path = p;
return 0;
}
/**
* bus_path_decode_unique() - decode unique object path
* @path: object path to decode
* @prefix: object path prefix
* @ret_sender: output parameter for sender-id label
* @ret_external: output parameter for external-id label
*
* This does the reverse of bus_path_encode_unique() (see its description for
* details). Both trailing labels, sender-id and external-id, are unescaped and
* returned in the given output parameters (the caller must free them).
*
* Note that this function returns 0 if the path does not match the template
* (see bus_path_encode_unique()), 1 if it matched.
*
* Returns: Negative error code on failure, 0 if the given object path does not
* match the template (return parameters are set to NULL), 1 if it was
* parsed successfully (return parameters contain allocated labels).
*/
int bus_path_decode_unique(const char *path, const char *prefix, char **ret_sender, char **ret_external) {
const char *p, *q;
char *sender, *external;
assert(object_path_is_valid(path));
assert(object_path_is_valid(prefix));
assert(ret_sender);
assert(ret_external);
p = object_path_startswith(path, prefix);
if (!p) {
*ret_sender = NULL;
*ret_external = NULL;
return 0;
}
q = strchr(p, '/');
if (!q) {
*ret_sender = NULL;
*ret_external = NULL;
return 0;
}
sender = bus_label_unescape_n(p, q - p);
external = bus_label_unescape(q + 1);
if (!sender || !external) {
free(sender);
free(external);
return -ENOMEM;
}
*ret_sender = sender;
*ret_external = external;
return 1;
}
bool is_kdbus_wanted(void) {
_cleanup_free_ char *value = NULL;
#ifdef ENABLE_KDBUS
const bool configured = true;
#else
const bool configured = false;
#endif
int r;
if (get_proc_cmdline_key("kdbus", NULL) > 0)
return true;
r = get_proc_cmdline_key("kdbus=", &value);
if (r <= 0)
return configured;
return parse_boolean(value) == 1;
}
bool is_kdbus_available(void) {
_cleanup_close_ int fd = -1;
struct kdbus_cmd cmd = { .size = sizeof(cmd), .flags = KDBUS_FLAG_NEGOTIATE };
if (!is_kdbus_wanted())
return false;
fd = open("/sys/fs/kdbus/control", O_RDWR | O_CLOEXEC | O_NONBLOCK | O_NOCTTY);
if (fd < 0)
return false;
return ioctl(fd, KDBUS_CMD_BUS_MAKE, &cmd) >= 0;
}