1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
|
/*-*- Mode: C; c-basic-offset: 8 -*-*/
/***
This file is part of systemd.
Copyright 2010 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 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
General Public License for more details.
You should have received a copy of the GNU General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <assert.h>
#include <sys/socket.h>
#include <errno.h>
#include <unistd.h>
#include <dbus/dbus.h>
#include "log.h"
#include "dbus-common.h"
int bus_check_peercred(DBusConnection *c) {
int fd;
struct ucred ucred;
socklen_t l;
assert(c);
assert_se(dbus_connection_get_unix_fd(c, &fd));
l = sizeof(struct ucred);
if (getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &ucred, &l) < 0) {
log_error("SO_PEERCRED failed: %m");
return -errno;
}
if (l != sizeof(struct ucred)) {
log_error("SO_PEERCRED returned wrong size.");
return -E2BIG;
}
if (ucred.uid != 0)
return -EPERM;
return 1;
}
int bus_connect(DBusBusType t, DBusConnection **_bus, DBusError *error) {
DBusConnection *bus;
assert(_bus);
/* If we are root, then let's not go via the bus */
if (geteuid() == 0 && t == DBUS_BUS_SYSTEM) {
if (!(bus = dbus_connection_open("unix:abstract=/org/freedesktop/systemd1/private", error)))
return -EIO;
if (bus_check_peercred(bus) < 0) {
dbus_connection_unref(bus);
dbus_set_error_const(error, DBUS_ERROR_ACCESS_DENIED, "Failed to verify owner of bus.");
return -EACCES;
}
} else {
if (!(bus = dbus_bus_get(t, error)))
return -EIO;
}
dbus_connection_set_exit_on_disconnect(bus, FALSE);
*_bus = bus;
return 0;
}
|
