summaryrefslogtreecommitdiff
path: root/udev.c
blob: 605a55bf19a956e69d4258774d8e5fa1e4df07af (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
/*
 * udev.c
 *
 * Userspace devfs
 *
 * Copyright (C) 2003,2004 Greg Kroah-Hartman <greg@kroah.com>
 *
 *	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 <ctype.h>
#include <errno.h>
#include <signal.h>
#include <unistd.h>

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

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 sigaction act;
	struct sysfs_class_device *class_dev;
	struct udevice udev;
	char path[SYSFS_PATH_MAX];
	int retval = -EINVAL;
	enum {
		ADD,
		REMOVE,
		UDEVSTART,
	} act_type;

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

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

	if (strstr(argv[0], "udevstart") || (argv[1] != NULL && strstr(argv[1], "udevstart"))) {
		act_type = UDEVSTART;
	} else {
		const char *action = getenv("ACTION");
		const char *devpath = getenv("DEVPATH");
		const char *subsystem = argv[1];

		if (!action) {
			dbg("no action?");
			goto exit;
		}
		if (strcmp(action, "add") == 0) {
			act_type = ADD;
		} else if (strcmp(action, "remove") == 0) {
			act_type = REMOVE;
		} else {
			dbg("no action '%s' for us", action);
			goto exit;
		}

		if (!devpath) {
			dbg("no devpath?");
			goto exit;
		}
		dbg("looking at '%s'", devpath);

		/* we only care about class devices and block stuff */
		if (!strstr(devpath, "class") && !strstr(devpath, "block")) {
			dbg("not a block or class device");
			goto exit;
		}

		if (!subsystem) {
			dbg("no subsystem");
			goto exit;
		}

		udev_set_values(&udev, devpath, subsystem, action);

		/* skip blacklisted subsystems */
		if (udev.type != 'n' && subsystem_expect_no_dev(subsystem)) {
			dbg("don't care about '%s' devices", subsystem);
			goto exit;
		};

	}

	/* set signal handlers */
	act.sa_handler = (void (*) (int))sig_handler;
	sigemptyset (&act.sa_mask);
	act.sa_flags = 0;
	/* alarm must not restart syscalls*/
	sigaction(SIGALRM, &act, NULL);
	sigaction(SIGINT, &act, NULL);
	sigaction(SIGTERM, &act, NULL);

	/* trigger timout to interrupt blocking syscalls */
	alarm(ALARM_TIMEOUT);

	switch(act_type) {
	case UDEVSTART:
		dbg("udevstart");

		/* disable all logging as it's much too slow on some facilities */
		udev_log = 0;
		unsetenv("UDEV_LOG");

		namedev_init();
		retval = udev_start();
		break;
	case ADD:
		dbg("udev add");

		/* open the device */
		snprintf(path, SYSFS_PATH_MAX, "%s%s", sysfs_path, udev.devpath);
		class_dev = sysfs_open_class_device_path(path);
		if (class_dev == NULL) {
			dbg ("sysfs_open_class_device_path failed");
			goto exit;
		}
		dbg("opened class_dev->name='%s'", class_dev->name);

		/* init rules */
		namedev_init();

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

		/* run dev.d/ scripts if we created a node or changed a netif name */
		if (udev.devname[0] != '\0') {
			setenv("DEVNAME", udev.devname, 1);
			dev_d_execute(&udev, DEVD_DIR, DEVD_SUFFIX);
		}

		sysfs_close_class_device(class_dev);
		break;
	case REMOVE:
		dbg("udev remove");

		/* get node from db, delete it*/
		retval = udev_remove_device(&udev);

		/* run dev.d/ scripts if we're not instructed to ignore the event */
		if (udev.devname[0] != '\0') {
			setenv("DEVNAME", udev.devname, 1);
			dev_d_execute(&udev, DEVD_DIR, DEVD_SUFFIX);
		}
	}

exit:
	logging_close();
	return retval;
}