summaryrefslogtreecommitdiff
path: root/udev.c
blob: c26ce46b64ded246f87a5cca5f329a9a6421989f (plain)
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
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
/*
 * udev.c
 *
 * Userspace devfs
 *
 * Copyright (C) 2003,2004 Greg Kroah-Hartman <greg@kroah.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 <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <ctype.h>
#include <errno.h>
#include <signal.h>
#include <unistd.h>

#include "libsysfs/sysfs/libsysfs.h"
#include "udev.h"
#include "udev_utils.h"
#include "udev_sysfs.h"
#include "udev_version.h"
#include "namedev.h"
#include "logging.h"


#ifdef LOG
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

/* decide if we should manage the whole hotplug event
 * for now look if the kernel calls udevsend instead of /sbin/hotplug
 */
static int manage_hotplug_event(void) {
	char helper[256];
	int fd;
	int len;

	/* don't handle hotplug.d if we are called directly */
	if (!getenv("UDEVD_EVENT"))
		return 0;

	fd = open("/proc/sys/kernel/hotplug", O_RDONLY);
	if (fd < 0)
		return 0;

	len = read(fd, helper, 256);
	close(fd);

	if (len < 0)
		return 0;
	helper[len] = '\0';

	if (strstr(helper, "udevsend"))
		return 1;

	return 0;
}

static void asmlinkage sig_handler(int signum)
{
	switch (signum) {
		case SIGALRM:
			exit(1);
		case SIGINT:
		case SIGTERM:
			exit(20 + signum);
	}
}

int main(int argc, char *argv[], char *envp[])
{
	struct sysfs_class_device *class_dev;
	struct sysfs_device *devices_dev;
	struct udevice udev;
	char path[SYSFS_PATH_MAX];
	const char *error;
	const char *action;
	const char *devpath;
	const char *subsystem;
	int managed_event;
	struct sigaction act;
	int retval = -EINVAL;

	if (argc == 2 && strcmp(argv[1], "-V") == 0) {
		printf("%s\n", UDEV_VERSION);
		exit(0);
	}

	logging_init("udev");
	dbg("version %s", UDEV_VERSION);

	udev_init_config();

	/* set signal handlers */
	memset(&act, 0x00, sizeof(act));
	act.sa_handler = (void (*) (int))sig_handler;
	sigemptyset (&act.sa_mask);
	act.sa_flags = 0;
	sigaction(SIGALRM, &act, NULL);
	sigaction(SIGINT, &act, NULL);
	sigaction(SIGTERM, &act, NULL);

	/* trigger timeout to prevent hanging processes */
	alarm(ALARM_TIMEOUT);

	if (strstr(argv[0], "udevstart") || (argc == 2 && strstr(argv[1], "udevstart"))) {
		dbg("udevstart");

		/* disable all logging, as it's much too slow on some facilities */
		udev_log = 0;

		namedev_init();
		retval = udev_start();
		goto exit;
	}

	/* let the executed programs know if we handle the whole hotplug event */
	managed_event = manage_hotplug_event();
	if (managed_event)
		setenv("MANAGED_EVENT", "1", 1);

	action = getenv("ACTION");
	devpath = getenv("DEVPATH");
	subsystem = getenv("SUBSYSTEM");
	/* older kernels passed the SUBSYSTEM only as argument */
	if (!subsystem && argc == 2)
		subsystem = argv[1];

	udev_init_device(&udev, devpath, subsystem);

	if (!action || !subsystem || !devpath) {
		dbg("action, subsystem or devpath missing");
		goto hotplug;
	}

	/* export logging flag, as called scripts may want to do the same as udev */
	if (udev_log)
		setenv("UDEV_LOG", "1", 1);

	if (udev.type == BLOCK || udev.type == CLASS || udev.type == NET) {
		if (strcmp(action, "add") == 0) {
			/* wait for sysfs and possibly add node */
			dbg("udev add");

			/* skip subsystems without "dev", but handle net devices */
			if (udev.type != NET && subsystem_expect_no_dev(udev.subsystem)) {
				dbg("don't care about '%s' devices", udev.subsystem);
				goto hotplug;
			}

			snprintf(path, SYSFS_PATH_MAX, "%s%s", sysfs_path, udev.devpath);
			class_dev = wait_class_device_open(path);
			if (class_dev == NULL) {
				dbg ("open class device failed");
				goto hotplug;
			}
			dbg("opened class_dev->name='%s'", class_dev->name);

			wait_for_class_device(class_dev, &error);

			/* init rules */
			namedev_init();

			/* name, create node, store in db */
			retval = udev_add_device(&udev, class_dev);

			sysfs_close_class_device(class_dev);
		} else if (strcmp(action, "remove") == 0) {
			/* possibly remove a node */
			dbg("udev remove");

			/* skip subsystems without "dev" */
			if (subsystem_expect_no_dev(udev.subsystem)) {
				dbg("don't care about '%s' devices", udev.subsystem);
				goto hotplug;
			}

			/* get node from db, remove db-entry, delete created node */
			retval = udev_remove_device(&udev);
		}

		/* run dev.d/ scripts if we created/deleted a node or changed a netif name */
		if (udev.devname[0] != '\0') {
			setenv("DEVNAME", udev.devname, 1);
			if (udev_dev_d)
				udev_multiplex_directory(&udev, DEVD_DIR, DEVD_SUFFIX);
		}
	} else if (udev.type == PHYSDEV) {
		if (strcmp(action, "add") == 0) {
			/* wait for sysfs */
			dbg("devices add");

			snprintf(path, SYSFS_PATH_MAX, "%s%s", sysfs_path, devpath);
			devices_dev = wait_devices_device_open(path);
			if (!devices_dev) {
				dbg("devices device unavailable (probably remove has beaten us)");
				goto hotplug;
			}
			dbg("devices device opened '%s'", path);

			wait_for_devices_device(devices_dev, &error);

			sysfs_close_device(devices_dev);
		} else if (strcmp(action, "remove") == 0) {
			dbg("devices remove");
		}
	} else {
		dbg("unhandled");
	}

hotplug:
	udev_cleanup_device(&udev);
	if (udev_hotplug_d && managed_event)
		udev_multiplex_directory(&udev, HOTPLUGD_DIR, HOTPLUG_SUFFIX);

exit:
	logging_close();
	return retval;
}