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
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
|
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <ctype.h>
#define DBUS_API_SUBJECT_TO_CHANGE
#include <dbus/dbus.h>
#include "../../udev_lib.h"
#include "../../logging.h"
#ifdef LOG
unsigned char logname[LOGNAME_SIZE];
void log_message(int level, const char *format, ...)
{
va_list args;
if (!udev_log)
return;
va_start(args, format);
vsyslog(level, format, args);
va_end(args);
}
#endif
/** variable for the connection the to system message bus or #NULL
* if we cannot connect or acquire the org.kernel.udev service
*/
static DBusConnection* sysbus_connection;
/** Disconnect from the system message bus */
static void sysbus_disconnect(void)
{
if (sysbus_connection == NULL)
return;
dbus_connection_disconnect(sysbus_connection);
sysbus_connection = NULL;
}
/** Connect to the system message bus */
static void sysbus_connect(void)
{
DBusError error;
/* Connect to a well-known bus instance, the system bus */
dbus_error_init(&error);
sysbus_connection = dbus_bus_get(DBUS_BUS_SYSTEM, &error);
if (sysbus_connection == NULL) {
dbg("cannot connect to system message bus, error %s: %s",
error.name, error.message);
dbus_error_free(&error);
return;
}
/* Acquire the org.kernel.udev service such that listeners
* know that the message is really from us and not from a
* random attacker. See the file udev_sysbus_policy.conf for
* details.
*
* Note that a service can have multiple owners (though there
* is a concept of a primary owner for reception of messages)
* so no race is introduced if two copies of udev is running
* at the same time.
*/
dbus_bus_acquire_service(sysbus_connection, "org.kernel.udev", 0,
&error);
if (dbus_error_is_set(&error)) {
printf("cannot acquire org.kernel.udev service, error %s: %s'",
error.name, error.message);
sysbus_disconnect();
return;
}
}
/** Send out a signal that a device node is created
*
* @param devname name of the device node, e.g. /dev/sda1
* @param path Sysfs path of device
*/
static void sysbus_send_create(const char *devname, const char *path)
{
DBusMessage* message;
DBusMessageIter iter;
/* object, interface, member */
message = dbus_message_new_signal("/org/kernel/udev/NodeMonitor",
"org.kernel.udev.NodeMonitor",
"NodeCreated");
dbus_message_iter_init(message, &iter);
dbus_message_iter_append_string(&iter, devname);
dbus_message_iter_append_string(&iter, path);
if ( !dbus_connection_send(sysbus_connection, message, NULL) )
dbg("error sending d-bus signal");
dbus_message_unref(message);
dbus_connection_flush(sysbus_connection);
}
/** Send out a signal that a device node is deleted
*
* @param devname Name of the device node, e.g. /udev/sda1
* @param path Sysfs path of device
*/
static void sysbus_send_remove(const char *devname, const char *path)
{
DBusMessage* message;
DBusMessageIter iter;
/* object, interface, member */
message = dbus_message_new_signal("/org/kernel/udev/NodeMonitor",
"org.kernel.udev.NodeMonitor",
"NodeDeleted");
dbus_message_iter_init(message, &iter);
dbus_message_iter_append_string(&iter, devname);
dbus_message_iter_append_string(&iter, path);
if ( !dbus_connection_send(sysbus_connection, message, NULL) )
dbg("error sending d-bus signal");
dbus_message_unref(message);
dbus_connection_flush(sysbus_connection);
}
int main(int argc, char *argv[], char *envp[])
{
char *action;
char *devpath;
char *devname;
int retval = 0;
init_logging("udev_dbus");
sysbus_connect();
if (sysbus_connection == NULL)
return 0;
action = get_action();
if (!action) {
dbg("no action?");
goto exit;
}
devpath = get_devpath();
if (!devpath) {
dbg("no devpath?");
goto exit;
}
devname = get_devname();
if (!devname) {
dbg("no devname?");
goto exit;
}
if (strcmp(action, "add") == 0) {
sysbus_send_create(devname, devpath);
} else {
if (strcmp(action, "remove") == 0) {
sysbus_send_remove(devname, devpath);
} else {
dbg("unknown action '%s'", action);
retval = -EINVAL;
}
}
exit:
sysbus_disconnect();
return retval;
}
|
