summaryrefslogtreecommitdiff
path: root/udev.c
blob: bbe50eeeb4c542f6d8be634026da91098b97c6e4 (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
/*
 * Copyright (C) 2003-2004 Greg Kroah-Hartman <greg@kroah.com>
 * Copyright (C) 2004-2006 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.,
 *	51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, 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 <syslog.h>

#include "udev.h"
#include "udev_rules.h"
#include "udev_selinux.h"

#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 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_device *dev;
	struct udevice *udev;
	const char *maj, *min;
	struct udev_rules rules;
	const char *action;
	const char *devpath;
	const char *subsystem;
	struct sigaction act;
	int devnull;
	int retval = -EINVAL;

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

	/* set std fd's to /dev/null, /sbin/hotplug forks us, we don't have them at all */
	devnull = open("/dev/null", O_RDWR);
	if (devnull >= 0)  {
		if (devnull != STDIN_FILENO)
			dup2(devnull, STDIN_FILENO);
		if (devnull != STDOUT_FILENO)
			dup2(devnull, STDOUT_FILENO);
		if (devnull != STDERR_FILENO)
			dup2(devnull, STDERR_FILENO);
		if (devnull > STDERR_FILENO)
			close(devnull);
	}

	logging_init("udev");
	if (devnull < 0)
		err("open /dev/null failed: %s", strerror(errno));
	udev_config_init();
	selinux_init();
	dbg("version %s", UDEV_VERSION);

	/* 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(UDEV_ALARM_TIMEOUT);

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

	if (action == NULL || subsystem == NULL || devpath == NULL) {
		err("action, subsystem or devpath missing");
		goto exit;
	}

	/* export log_priority , as called programs may want to do the same as udev */
	if (udev_log_priority) {
		char priority[32];

		sprintf(priority, "%i", udev_log_priority);
		setenv("UDEV_LOG", priority, 1);
	}

	sysfs_init();
	udev_rules_init(&rules, 0);

	dev = sysfs_device_get(devpath);
	if (dev == NULL) {
		info("unable to open '%s'", devpath);
		goto fail;
	}

	udev = udev_device_init();
	if (udev == NULL)
		goto fail;

	/* override built-in sysfs device */
	udev->dev = dev;
	strlcpy(udev->action, action, sizeof(udev->action));

	/* get dev_t from environment, which is needed for "remove" to work, "add" works also from sysfs */
	maj = getenv("MAJOR");
	min = getenv("MINOR");
	if (maj != NULL && min != NULL)
		udev->devt = makedev(atoi(maj), atoi(min));
	else
		udev->devt = udev_device_get_devt(udev);

	retval = udev_device_event(&rules, udev);

	if (retval == 0 && !udev->ignore_device && udev_run) {
		struct name_entry *name_loop;

		dbg("executing run list");
		list_for_each_entry(name_loop, &udev->run_list, node) {
			if (strncmp(name_loop->name, "socket:", strlen("socket:")) == 0)
				pass_env_to_socket(&name_loop->name[strlen("socket:")], devpath, action);
			else {
				char program[PATH_SIZE];

				strlcpy(program, name_loop->name, sizeof(program));
				udev_rules_apply_format(udev, program, sizeof(program));
				run_program(program, udev->dev->subsystem, NULL, 0, NULL, (udev_log_priority >= LOG_INFO));
			}
		}
	}

	udev_device_cleanup(udev);
fail:
	udev_rules_cleanup(&rules);
	sysfs_cleanup();

exit:
	logging_close();
	if (retval != 0)
		return 1;
	return 0;
}