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
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
|
/*
* udevsend.c
*
* Copyright (C) 2004 Ling, Xiaofeng <xiaofeng.ling@intel.com>
* Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
*
* 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 version 2 of the License.
*
* 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.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <unistd.h>
#include <string.h>
#include <time.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <sys/un.h>
#include <linux/stddef.h>
#include "udev.h"
#include "udev_version.h"
#include "udevd.h"
#include "logging.h"
/* global variables */
static int sock = -1;
#ifdef USE_LOG
void log_message (int priority, const char *format, ...)
{
va_list args;
if (priority > udev_log_priority)
return;
va_start(args, format);
vsyslog(priority, format, args);
va_end(args);
}
#endif
static int start_daemon(void)
{
pid_t pid;
pid_t child_pid;
char *const argv[] = { "udevd", NULL };
char *const envp[] = { NULL };
pid = fork();
switch (pid) {
case 0:
/* helper child */
child_pid = fork();
switch (child_pid) {
case 0:
/* daemon with empty environment */
close(sock);
execve(UDEVD_BIN, argv, envp);
err("exec of daemon failed");
_exit(1);
case -1:
err("fork of daemon failed");
return -1;
default:
exit(0);
}
break;
case -1:
err("fork of helper failed");
return -1;
default:
waitpid(pid, NULL, 0);
}
return 0;
}
static void run_udev(const char *subsystem)
{
char *const argv[] = { "udev", (char *)subsystem, NULL };
pid_t pid;
pid = fork();
switch (pid) {
case 0:
/* child */
execv(UDEV_BIN, argv);
err("exec of udev child failed");
_exit(1);
break;
case -1:
err("fork of udev child failed");
break;
default:
waitpid(pid, NULL, 0);
}
}
int main(int argc, char *argv[], char *envp[])
{
static struct udevd_msg usend_msg;
int usend_msg_len;
int i;
int loop;
struct sockaddr_un saddr;
socklen_t addrlen;
int bufpos = 0;
int retval = 1;
int started_daemon = 0;
const char *subsystem = NULL;
logging_init("udevsend");
#ifdef USE_LOG
udev_init_config();
#endif
dbg("version %s", UDEV_VERSION);
sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
if (sock == -1) {
err("error getting socket");
goto fallback;
}
memset(&saddr, 0x00, sizeof(struct sockaddr_un));
saddr.sun_family = AF_LOCAL;
/* use abstract namespace for socket path */
strcpy(&saddr.sun_path[1], UDEVD_SOCK_PATH);
addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1;
memset(&usend_msg, 0x00, sizeof(struct udevd_msg));
strcpy(usend_msg.magic, UDEV_MAGIC);
usend_msg.type = UDEVD_UEVENT_UDEVSEND;
/* copy all keys to send buffer */
for (i = 0; envp[i]; i++) {
const char *key;
int keylen;
key = envp[i];
keylen = strlen(key);
/* prevent loops in the scripts we execute */
if (strncmp(key, "UDEVD_EVENT=", 12) == 0) {
dbg("seems that the event source is not the kernel, just exit");
goto exit;
}
if (bufpos + keylen >= UEVENT_BUFFER_SIZE-1) {
err("environment buffer too small, probably not called by the kernel");
continue;
}
/* remember the SUBSYSTEM */
if (strncmp(key, "SUBSYSTEM=", 10) == 0)
subsystem = &key[10];
dbg("add '%s' to env[%i] buffer", key, i);
strcpy(&usend_msg.envbuf[bufpos], key);
bufpos += keylen + 1;
}
/* older kernels passed the SUBSYSTEM only as the first argument */
if (!subsystem && argc == 2) {
bufpos += sprintf(&usend_msg.envbuf[bufpos], "SUBSYSTEM=%s", argv[1]) + 1;
dbg("add 'SUBSYSTEM=%s' to env[%i] buffer from argv", argv[1], i);
}
usend_msg_len = offsetof(struct udevd_msg, envbuf) + bufpos;
dbg("usend_msg_len=%i", usend_msg_len);
/* If we can't send, try to start daemon and resend message */
loop = UDEVSEND_WAIT_MAX_SECONDS * UDEVSEND_WAIT_LOOP_PER_SECOND;
while (--loop) {
retval = sendto(sock, &usend_msg, usend_msg_len, 0, (struct sockaddr *)&saddr, addrlen);
if (retval != -1) {
retval = 0;
goto exit;
}
if (errno != ECONNREFUSED) {
err("error sending message (%s)", strerror(errno));
goto fallback;
}
if (!started_daemon) {
info("try to start udevd daemon");
retval = start_daemon();
if (retval) {
dbg("error starting daemon");
goto fallback;
}
dbg("udevd daemon started");
started_daemon = 1;
} else {
dbg("retry to connect %d", UDEVSEND_WAIT_MAX_SECONDS * UDEVSEND_WAIT_LOOP_PER_SECOND - loop);
usleep(1000 * 1000 / UDEVSEND_WAIT_LOOP_PER_SECOND);
}
}
fallback:
err("unable to connect to event daemon, try to call udev directly");
run_udev(subsystem);
exit:
if (sock != -1)
close(sock);
logging_close();
return retval;
}
|
