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[thirdparty/systemd.git] / udevsend.c
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1/*
2 * udevsend.c
3 *
4 * Userspace devfs
5 *
6 * Copyright (C) 2004 Ling, Xiaofeng <xiaofeng.ling@intel.com>
7 * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
8 *
9 *
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by the
12 * Free Software Foundation version 2 of the License.
13 *
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write to the Free Software Foundation, Inc.,
21 * 675 Mass Ave, Cambridge, MA 02139, USA.
22 *
23 */
24
25#include <sys/types.h>
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26#include <sys/socket.h>
27#include <sys/wait.h>
28#include <sys/un.h>
e5a2989e 29#include <time.h>
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30#include <errno.h>
31#include <stdio.h>
32#include <stdlib.h>
1dadabd7 33#include <stddef.h>
7fafc032 34#include <string.h>
33db4b8d 35#include <unistd.h>
2f6cbd19 36#include <linux/stddef.h>
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37
38#include "udev.h"
35b7d88c 39#include "udev_version.h"
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40#include "udevd.h"
41#include "logging.h"
42
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43/* global variables */
44static int sock = -1;
45
6c18b1fb 46#ifdef USE_LOG
6b493a20 47void log_message (int priority, const char *format, ...)
51a8bb2f 48{
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49 va_list args;
50
51 if (priority > udev_log_priority)
52 return;
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53
54 va_start(args, format);
6b493a20 55 vsyslog(priority, format, args);
d026a35d 56 va_end(args);
51a8bb2f 57}
d026a35d 58#endif
51a8bb2f 59
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60static int start_daemon(void)
61{
62 pid_t pid;
63 pid_t child_pid;
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64 char *const argv[] = { "udevd", NULL };
65 char *const envp[] = { NULL };
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66
67 pid = fork();
68 switch (pid) {
69 case 0:
70 /* helper child */
71 child_pid = fork();
72 switch (child_pid) {
73 case 0:
4497fcbf 74 /* daemon with empty environment */
13f24d59 75 close(sock);
4497fcbf 76 execve(UDEVD_BIN, argv, envp);
6b493a20 77 err("exec of daemon failed");
4a231017 78 _exit(1);
33db4b8d 79 case -1:
6b493a20 80 err("fork of daemon failed");
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81 return -1;
82 default:
83 exit(0);
84 }
85 break;
86 case -1:
6b493a20 87 err("fork of helper failed");
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88 return -1;
89 default:
e920fed3 90 waitpid(pid, NULL, 0);
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91 }
92 return 0;
93}
94
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95static void run_udev(const char *subsystem)
96{
4497fcbf 97 char *const argv[] = { "udev", (char *)subsystem, NULL };
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98 pid_t pid;
99
100 pid = fork();
101 switch (pid) {
102 case 0:
103 /* child */
4497fcbf 104 execv(UDEV_BIN, argv);
6b493a20 105 err("exec of udev child failed");
5cab7caa 106 _exit(1);
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107 break;
108 case -1:
6b493a20 109 err("fork of udev child failed");
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110 break;
111 default:
e920fed3 112 waitpid(pid, NULL, 0);
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113 }
114}
115
4a231017 116int main(int argc, char *argv[], char *envp[])
7fafc032 117{
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118 static struct udevsend_msg usend_msg;
119 int usend_msg_len;
120 int i;
33db4b8d 121 int loop;
53921bfa 122 struct sockaddr_un saddr;
1dadabd7 123 socklen_t addrlen;
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124 int bufpos = 0;
125 int retval = 1;
2f6cbd19 126 int started_daemon = 0;
4497fcbf 127 const char *subsystem = NULL;
7fafc032 128
7257cb18 129 logging_init("udevsend");
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130#ifdef USE_LOG
131 udev_init_config();
132#endif
8bbf2751 133 dbg("version %s", UDEV_VERSION);
95a6f4c8 134
2f6cbd19 135 sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
53921bfa 136 if (sock == -1) {
6b493a20 137 err("error getting socket");
28e169f0 138 goto fallback;
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139 }
140
e5a2989e 141 memset(&saddr, 0x00, sizeof(struct sockaddr_un));
53921bfa 142 saddr.sun_family = AF_LOCAL;
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143 /* use abstract namespace for socket path */
144 strcpy(&saddr.sun_path[1], UDEVD_SOCK_PATH);
1dadabd7 145 addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1;
53921bfa 146
4a231017 147 memset(&usend_msg, 0x00, sizeof(struct udevsend_msg));
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148 strcpy(usend_msg.magic, UDEV_MAGIC);
149
150 /* copy all keys to send buffer */
151 for (i = 0; envp[i]; i++) {
152 const char *key;
153 int keylen;
154
155 key = envp[i];
156 keylen = strlen(key);
4a231017 157
4497fcbf 158 /* prevent loops in the scripts we execute */
eabfc973 159 if (strncmp(key, "UDEVD_EVENT=", 12) == 0) {
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160 dbg("seems that the event source is not the kernel, just exit");
161 goto exit;
162 }
163
d3c37635 164 if (bufpos + keylen >= HOTPLUG_BUFFER_SIZE-1) {
6b493a20 165 err("environment buffer too small, probably not called by the kernel");
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166 continue;
167 }
168
4497fcbf 169 /* remember the SUBSYSTEM */
4a231017 170 if (strncmp(key, "SUBSYSTEM=", 10) == 0)
4497fcbf 171 subsystem = &key[10];
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172
173 dbg("add '%s' to env[%i] buffer", key, i);
174 strcpy(&usend_msg.envbuf[bufpos], key);
175 bufpos += keylen + 1;
176 }
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177 /* older kernels passed the SUBSYSTEM only as the first argument */
178 if (!subsystem && argc == 2) {
179 bufpos += sprintf(&usend_msg.envbuf[bufpos], "SUBSYSTEM=%s", argv[1]) + 1;
180 dbg("add 'SUBSYSTEM=%s' to env[%i] buffer from argv", argv[1], i);
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181 }
182
183 usend_msg_len = offsetof(struct udevsend_msg, envbuf) + bufpos;
184 dbg("usend_msg_len=%i", usend_msg_len);
0028653c 185
2f6cbd19 186 /* If we can't send, try to start daemon and resend message */
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187 loop = SEND_WAIT_MAX_SECONDS * SEND_WAIT_LOOP_PER_SECOND;
188 while (--loop) {
4a231017 189 retval = sendto(sock, &usend_msg, usend_msg_len, 0, (struct sockaddr *)&saddr, addrlen);
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190 if (retval != -1) {
191 retval = 0;
28e169f0 192 goto exit;
2f6cbd19 193 }
28e169f0 194
2f6cbd19 195 if (errno != ECONNREFUSED) {
6b493a20 196 err("error sending message (%s)", strerror(errno));
28e169f0 197 goto fallback;
2f6cbd19 198 }
28e169f0 199
2f6cbd19 200 if (!started_daemon) {
6b493a20 201 info("try to start udevd daemon");
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202 retval = start_daemon();
203 if (retval) {
e750d24b 204 dbg("error starting daemon");
28e169f0 205 goto fallback;
2f6cbd19 206 }
e750d24b 207 dbg("udevd daemon started");
2f6cbd19 208 started_daemon = 1;
53921bfa 209 } else {
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210 dbg("retry to connect %d", SEND_WAIT_MAX_SECONDS * SEND_WAIT_LOOP_PER_SECOND - loop);
211 usleep(1000 * 1000 / SEND_WAIT_LOOP_PER_SECOND);
53921bfa 212 }
7fafc032 213 }
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214
215fallback:
6b493a20 216 err("unable to connect to event daemon, try to call udev directly");
4497fcbf 217 run_udev(subsystem);
28e169f0 218
33db4b8d 219exit:
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220 if (sock != -1)
221 close(sock);
222
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223 logging_close();
224
2f6cbd19 225 return retval;
7fafc032 226}