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
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
|
/* -*- Mode: C; tab-width: 4; indent-tabs-mode: t; c-basic-offset: 4 -*- */
/* vim: set ft=c ts=4 sts=4 sw=4 noexpandtab smartindent: */
/*
* This program 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.
*
* This program 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 this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* (C) Copyright 2012 Red Hat, Inc.
*/
/*
* This example monitors whether NM is running by checking D-Bus
* NameOwnerChanged signal.
* It uses dbus-glib library.
*
* Standalone compilation:
* gcc -Wall `pkg-config --libs --cflags glib-2.0 dbus-glib-1` monitor-nm-running.c -o monitor-nm-running
*/
#include <glib.h>
#include <dbus/dbus-glib.h>
#include <dbus/dbus-glib-bindings.h>
#include <string.h>
#define NM_DBUS_SERVICE "org.freedesktop.NetworkManager"
static void
proxy_name_owner_changed (DBusGProxy *proxy,
const char *name,
const char *old_owner,
const char *new_owner,
gpointer user_data)
{
gboolean *nm_running = (gboolean *) user_data;
gboolean old_good = (old_owner && strlen (old_owner));
gboolean new_good = (new_owner && strlen (new_owner));
gboolean new_running = FALSE;
/* We are only interested in NetworkManager */
if (!name || strcmp (name, NM_DBUS_SERVICE) != 0)
return;
if (!old_good && new_good)
new_running = TRUE;
else if (old_good && !new_good)
new_running = FALSE;
*nm_running = new_running;
g_print ("name: '%s', old_owner: '%s', new_owner: '%s'", name, old_owner, new_owner);
g_print (" => NM is %s\n", *nm_running ? "running" : "not running");
}
int
main (int argc, char *argv[])
{
DBusGConnection *bus;
DBusGProxy *bus_proxy;
GMainLoop *loop = NULL;
GError *err = NULL;
gboolean nm_running;
/* Initialize GType system */
g_type_init ();
g_print ("Monitor 'org.freedesktop.NetworkManager' D-Bus name\n");
g_print ("===================================================\n");
/* Get system bus */
bus = dbus_g_bus_get (DBUS_BUS_SYSTEM, NULL);
/* Create a D-Bus proxy to D-Bus daemon */
bus_proxy = dbus_g_proxy_new_for_name (bus,
"org.freedesktop.DBus",
"/org/freedesktop/DBus",
"org.freedesktop.DBus");
if (!bus_proxy) {
g_message ("Error: Couldn't create D-Bus object proxy for org.freedesktop.DBus.");
dbus_g_connection_unref (bus);
return -1;
}
/* Call NameHasOwner method to find out if NM is running. When NM runs it claims
* 'org.freedesktop.NetworkManager' service name on D-Bus */
if (!org_freedesktop_DBus_name_has_owner (bus_proxy, NM_DBUS_SERVICE, &nm_running, &err)) {
g_message ("Error: NameHasOwner request failed: %s",
(err && err->message) ? err->message : "(unknown)");
g_clear_error (&err);
g_object_unref (bus_proxy);
dbus_g_connection_unref (bus);
return -1;
}
g_print ("NM is %s\n", nm_running ? "running" : "not running");
/* Connect to NameOwnerChanged signal to monitor NM running state */
dbus_g_proxy_add_signal (bus_proxy, "NameOwnerChanged",
G_TYPE_STRING, G_TYPE_STRING, G_TYPE_STRING,
G_TYPE_INVALID);
dbus_g_proxy_connect_signal (bus_proxy,
"NameOwnerChanged",
G_CALLBACK (proxy_name_owner_changed),
&nm_running, NULL);
loop = g_main_loop_new (NULL, FALSE); /* Create main loop */
g_main_loop_run (loop); /* Run main loop */
g_object_unref (bus_proxy);
dbus_g_connection_unref (bus);
return 0;
}
|