bus-convenience.c revision 0f51442056157cfec2efc52ddbff7392b0ff674a
/*-*- 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 <http://www.gnu.org/licenses/>.
***/
#include "bus-internal.h"
#include "bus-message.h"
#include "bus-signature.h"
#include "bus-util.h"
#include "bus-type.h"
_public_ int sd_bus_emit_signal(
sd_bus *bus,
const char *path,
const char *interface,
const char *member,
const char *types, ...) {
_cleanup_bus_message_unref_ sd_bus_message *m = NULL;
int r;
assert_return(bus, -EINVAL);
assert_return(!bus_pid_changed(bus), -ECHILD);
if (!BUS_IS_OPEN(bus->state))
return -ENOTCONN;
r = sd_bus_message_new_signal(bus, &m, path, interface, member);
if (r < 0)
return r;
if (!isempty(types)) {
va_list ap;
va_start(ap, types);
r = bus_message_append_ap(m, types, ap);
va_end(ap);
if (r < 0)
return r;
}
return sd_bus_send(bus, m, NULL);
}
_public_ int sd_bus_call_method(
sd_bus *bus,
const char *destination,
const char *path,
const char *interface,
const char *member,
sd_bus_error *error,
sd_bus_message **reply,
const char *types, ...) {
_cleanup_bus_message_unref_ sd_bus_message *m = NULL;
int r;
assert_return(bus, -EINVAL);
assert_return(!bus_pid_changed(bus), -ECHILD);
if (!BUS_IS_OPEN(bus->state))
return -ENOTCONN;
r = sd_bus_message_new_method_call(bus, &m, destination, path, interface, member);
if (r < 0)
return r;
if (!isempty(types)) {
va_list ap;
va_start(ap, types);
r = bus_message_append_ap(m, types, ap);
va_end(ap);
if (r < 0)
return r;
}
return sd_bus_call(bus, m, 0, error, reply);
}
_public_ int sd_bus_reply_method_return(
sd_bus_message *call,
const char *types, ...) {
_cleanup_bus_message_unref_ sd_bus_message *m = NULL;
int r;
assert_return(call, -EINVAL);
assert_return(call->sealed, -EPERM);
assert_return(call->header->type == SD_BUS_MESSAGE_METHOD_CALL, -EINVAL);
assert_return(call->bus, -EINVAL);
assert_return(!bus_pid_changed(call->bus), -ECHILD);
if (!BUS_IS_OPEN(call->bus->state))
return -ENOTCONN;
if (call->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED)
return 0;
r = sd_bus_message_new_method_return(call, &m);
if (r < 0)
return r;
if (!isempty(types)) {
va_list ap;
va_start(ap, types);
r = bus_message_append_ap(m, types, ap);
va_end(ap);
if (r < 0)
return r;
}
return sd_bus_send(call->bus, m, NULL);
}
_public_ int sd_bus_reply_method_error(
sd_bus_message *call,
const sd_bus_error *e) {
_cleanup_bus_message_unref_ sd_bus_message *m = NULL;
int r;
assert_return(call, -EINVAL);
assert_return(call->sealed, -EPERM);
assert_return(call->header->type == SD_BUS_MESSAGE_METHOD_CALL, -EINVAL);
assert_return(sd_bus_error_is_set(e), -EINVAL);
assert_return(call->bus, -EINVAL);
assert_return(!bus_pid_changed(call->bus), -ECHILD);
if (!BUS_IS_OPEN(call->bus->state))
return -ENOTCONN;
if (call->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED)
return 0;
r = sd_bus_message_new_method_error(call, &m, e);
if (r < 0)
return r;
return sd_bus_send(call->bus, m, NULL);
}
_public_ int sd_bus_reply_method_errorf(
sd_bus_message *call,
const char *name,
const char *format,
...) {
_cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
va_list ap;
assert_return(call, -EINVAL);
assert_return(call->sealed, -EPERM);
assert_return(call->header->type == SD_BUS_MESSAGE_METHOD_CALL, -EINVAL);
assert_return(call->bus, -EINVAL);
assert_return(!bus_pid_changed(call->bus), -ECHILD);
if (!BUS_IS_OPEN(call->bus->state))
return -ENOTCONN;
if (call->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED)
return 0;
va_start(ap, format);
bus_error_setfv(&error, name, format, ap);
va_end(ap);
return sd_bus_reply_method_error(call, &error);
}
_public_ int sd_bus_reply_method_errno(
sd_bus_message *call,
int error,
const sd_bus_error *p) {
_cleanup_bus_error_free_ sd_bus_error berror = SD_BUS_ERROR_NULL;
assert_return(call, -EINVAL);
assert_return(call->sealed, -EPERM);
assert_return(call->header->type == SD_BUS_MESSAGE_METHOD_CALL, -EINVAL);
assert_return(call->bus, -EINVAL);
assert_return(!bus_pid_changed(call->bus), -ECHILD);
if (!BUS_IS_OPEN(call->bus->state))
return -ENOTCONN;
if (call->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED)
return 0;
if (sd_bus_error_is_set(p))
return sd_bus_reply_method_error(call, p);
sd_bus_error_set_errno(&berror, error);
return sd_bus_reply_method_error(call, &berror);
}
_public_ int sd_bus_reply_method_errnof(
sd_bus_message *call,
int error,
const char *format,
...) {
_cleanup_bus_error_free_ sd_bus_error berror = SD_BUS_ERROR_NULL;
va_list ap;
assert_return(call, -EINVAL);
assert_return(call->sealed, -EPERM);
assert_return(call->header->type == SD_BUS_MESSAGE_METHOD_CALL, -EINVAL);
assert_return(call->bus, -EINVAL);
assert_return(!bus_pid_changed(call->bus), -ECHILD);
if (!BUS_IS_OPEN(call->bus->state))
return -ENOTCONN;
if (call->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED)
return 0;
va_start(ap, format);
sd_bus_error_set_errnofv(&berror, error, format, ap);
va_end(ap);
return sd_bus_reply_method_error(call, &berror);
}
_public_ int sd_bus_get_property(
sd_bus *bus,
const char *destination,
const char *path,
const char *interface,
const char *member,
sd_bus_error *error,
sd_bus_message **reply,
const char *type) {
sd_bus_message *rep = NULL;
int r;
assert_return(bus, -EINVAL);
assert_return(isempty(interface) || interface_name_is_valid(interface), -EINVAL);
assert_return(member_name_is_valid(member), -EINVAL);
assert_return(reply, -EINVAL);
assert_return(signature_is_single(type, false), -EINVAL);
assert_return(!bus_pid_changed(bus), -ECHILD);
if (!BUS_IS_OPEN(bus->state))
return -ENOTCONN;
r = sd_bus_call_method(bus, destination, path, "org.freedesktop.DBus.Properties", "Get", error, &rep, "ss", strempty(interface), member);
if (r < 0)
return r;
r = sd_bus_message_enter_container(rep, 'v', type);
if (r < 0) {
sd_bus_message_unref(rep);
return r;
}
*reply = rep;
return 0;
}
_public_ int sd_bus_get_property_trivial(
sd_bus *bus,
const char *destination,
const char *path,
const char *interface,
const char *member,
sd_bus_error *error,
char type, void *ptr) {
_cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
int r;
assert_return(bus, -EINVAL);
assert_return(isempty(interface) || interface_name_is_valid(interface), -EINVAL);
assert_return(member_name_is_valid(member), -EINVAL);
assert_return(bus_type_is_trivial(type), -EINVAL);
assert_return(ptr, -EINVAL);
assert_return(!bus_pid_changed(bus), -ECHILD);
if (!BUS_IS_OPEN(bus->state))
return -ENOTCONN;
r = sd_bus_call_method(bus, destination, path, "org.freedesktop.DBus.Properties", "Get", error, &reply, "ss", strempty(interface), member);
if (r < 0)
return r;
r = sd_bus_message_enter_container(reply, 'v', CHAR_TO_STR(type));
if (r < 0)
return r;
r = sd_bus_message_read_basic(reply, type, ptr);
if (r < 0)
return r;
return 0;
}
_public_ int sd_bus_get_property_string(
sd_bus *bus,
const char *destination,
const char *path,
const char *interface,
const char *member,
sd_bus_error *error,
char **ret) {
_cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
const char *s;
char *n;
int r;
assert_return(bus, -EINVAL);
assert_return(isempty(interface) || interface_name_is_valid(interface), -EINVAL);
assert_return(member_name_is_valid(member), -EINVAL);
assert_return(ret, -EINVAL);
assert_return(!bus_pid_changed(bus), -ECHILD);
if (!BUS_IS_OPEN(bus->state))
return -ENOTCONN;
r = sd_bus_call_method(bus, destination, path, "org.freedesktop.DBus.Properties", "Get", error, &reply, "ss", strempty(interface), member);
if (r < 0)
return r;
r = sd_bus_message_enter_container(reply, 'v', "s");
if (r < 0)
return r;
r = sd_bus_message_read_basic(reply, 's', &s);
if (r < 0)
return r;
n = strdup(s);
if (!n)
return -ENOMEM;
*ret = n;
return 0;
}
_public_ int sd_bus_get_property_strv(
sd_bus *bus,
const char *destination,
const char *path,
const char *interface,
const char *member,
sd_bus_error *error,
char ***ret) {
_cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
int r;
assert_return(bus, -EINVAL);
assert_return(isempty(interface) || interface_name_is_valid(interface), -EINVAL);
assert_return(member_name_is_valid(member), -EINVAL);
assert_return(ret, -EINVAL);
assert_return(!bus_pid_changed(bus), -ECHILD);
if (!BUS_IS_OPEN(bus->state))
return -ENOTCONN;
r = sd_bus_call_method(bus, destination, path, "org.freedesktop.DBus.Properties", "Get", error, &reply, "ss", strempty(interface), member);
if (r < 0)
return r;
r = sd_bus_message_enter_container(reply, 'v', NULL);
if (r < 0)
return r;
r = sd_bus_message_read_strv(reply, ret);
if (r < 0)
return r;
return 0;
}
_public_ int sd_bus_set_property(
sd_bus *bus,
const char *destination,
const char *path,
const char *interface,
const char *member,
sd_bus_error *error,
const char *type, ...) {
_cleanup_bus_message_unref_ sd_bus_message *m = NULL;
va_list ap;
int r;
assert_return(bus, -EINVAL);
assert_return(isempty(interface) || interface_name_is_valid(interface), -EINVAL);
assert_return(member_name_is_valid(member), -EINVAL);
assert_return(signature_is_single(type, false), -EINVAL);
assert_return(!bus_pid_changed(bus), -ECHILD);
if (!BUS_IS_OPEN(bus->state))
return -ENOTCONN;
r = sd_bus_message_new_method_call(bus, &m, destination, path, "org.freedesktop.DBus.Properties", "Set");
if (r < 0)
return r;
r = sd_bus_message_append(m, "ss", strempty(interface), member);
if (r < 0)
return r;
r = sd_bus_message_open_container(m, 'v', type);
if (r < 0)
return r;
va_start(ap, type);
r = bus_message_append_ap(m, type, ap);
va_end(ap);
if (r < 0)
return r;
r = sd_bus_message_close_container(m);
if (r < 0)
return r;
return sd_bus_call(bus, m, 0, error, NULL);
}
_public_ int sd_bus_query_sender_creds(sd_bus_message *call, uint64_t mask, sd_bus_creds **creds) {
sd_bus_creds *c;
assert_return(call, -EINVAL);
assert_return(call->sealed, -EPERM);
assert_return(call->bus, -EINVAL);
assert_return(!bus_pid_changed(call->bus), -ECHILD);
if (!BUS_IS_OPEN(call->bus->state))
return -ENOTCONN;
c = sd_bus_message_get_creds(call);
/* All data we need? */
if (c && (mask & ~c->mask) == 0) {
*creds = sd_bus_creds_ref(c);
return 0;
}
/* No data passed? Or not enough data passed to retrieve the missing bits? */
if (!c || !(c->mask & SD_BUS_CREDS_PID)) {
/* We couldn't read anything from the call, let's try
* to get it from the sender or peer. */
if (call->sender)
/* There's a sender, but the creds are
* missing. This means we are talking via
* dbus1, or are getting a message that was
* sent to us via kdbus, but was converted
* from a dbus1 message by the bus-proxy and
* thus also lacks the creds. */
return sd_bus_get_name_creds(call->bus, call->sender, mask, creds);
else
/* There's no sender, hence we are on a dbus1
* direct connection. For direct connections
* the credentials of the AF_UNIX peer matter,
* which may be queried via
* sd_bus_get_owner_creds(). */
return sd_bus_get_owner_creds(call->bus, mask, creds);
}
return bus_creds_extend_by_pid(c, mask, creds);
}
_public_ int sd_bus_query_sender_privilege(sd_bus_message *call, int capability) {
_cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL;
uid_t our_uid;
bool know_caps = false;
int r;
assert_return(call, -EINVAL);
assert_return(call->sealed, -EPERM);
assert_return(call->bus, -EINVAL);
assert_return(!bus_pid_changed(call->bus), -ECHILD);
if (!BUS_IS_OPEN(call->bus->state))
return -ENOTCONN;
if (capability >= 0) {
r = sd_bus_query_sender_creds(call, SD_BUS_CREDS_UID|SD_BUS_CREDS_EUID|SD_BUS_CREDS_EFFECTIVE_CAPS, &creds);
if (r < 0)
return r;
/* We cannot use augmented caps for authorization,
* since then data is acquired raceful from
* /proc. This can never actually happen, but let's
* better be safe than sorry, and do an extra check
* here. */
assert_return((sd_bus_creds_get_augmented_mask(creds) & SD_BUS_CREDS_EFFECTIVE_CAPS) == 0, -EPERM);
/* Note that not even on kdbus we might have the caps
* field, due to faked identities, or namespace
* translation issues. */
r = sd_bus_creds_has_effective_cap(creds, capability);
if (r > 0)
return 1;
if (r == 0)
know_caps = true;
} else {
r = sd_bus_query_sender_creds(call, SD_BUS_CREDS_UID|SD_BUS_CREDS_EUID, &creds);
if (r < 0)
return r;
}
/* Now, check the UID, but only if the capability check wasn't
* sufficient */
our_uid = getuid();
if (our_uid != 0 || !know_caps || capability < 0) {
uid_t sender_uid;
/* We cannot use augmented uid/euid for authorization,
* since then data is acquired raceful from
* /proc. This can never actually happen, but let's
* better be safe than sorry, and do an extra check
* here. */
assert_return((sd_bus_creds_get_augmented_mask(creds) & (SD_BUS_CREDS_UID|SD_BUS_CREDS_EUID)) == 0, -EPERM);
/* Try to use the EUID, if we have it. */
r = sd_bus_creds_get_euid(creds, &sender_uid);
if (r < 0)
r = sd_bus_creds_get_uid(creds, &sender_uid);
if (r >= 0) {
/* Sender has same UID as us, then let's grant access */
if (sender_uid == our_uid)
return 1;
/* Sender is root, we are not root. */
if (our_uid != 0 && sender_uid == 0)
return 1;
}
}
return 0;
}