summaryrefslogtreecommitdiff
path: root/udev.c
blob: 8d5be0542e8d3edff7fabc74f388eaeecb01ade2 (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
/*
 * 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.
 *
 */

#define _KLIBC_HAS_ARCH_SIG_ATOMIC_T
#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
#include <signal.h>

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

/* timeout flag for udevdb */
extern sig_atomic_t gotalarm;

/* global variables */
char **main_argv;
char **main_envp;

#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:
			gotalarm = 1;
			info("error: timeout reached, event probably not handled correctly");
			break;
		case SIGINT:
		case SIGTERM:
			udevdb_exit();
			exit(20 + signum);
		default:
			dbg("unhandled signal %d", signum);
	}
}

/* list of subsystems we don't care about. not listing such systems here
 * is not critical, but it makes it faster as we don't look for the "dev" file
 */
static int subsystem_without_dev(const char *subsystem)
{
	char *subsystem_blacklist[] = {
		"scsi_host",
		"scsi_device",
		"usb_host",
		"pci_bus",
		"pcmcia_socket",
		"bluetooth",
		"i2c-adapter",
		"pci_bus",
		"ieee1394",
		"ieee1394_host",
		"ieee1394_node",
		NULL
	};
	char **subsys;

	for (subsys = subsystem_blacklist; *subsys != NULL; subsys++) {
		if (strcmp(subsystem, *subsys) == 0)
			return 1;
	}

	return 0;
}

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);

	main_argv = argv;
	main_envp = envp;

	logging_init("udev");

	udev_init_config();

	if (strstr(argv[0], "udevstart")) {
		act_type = UDEVSTART;
	} else {
		const char *action = get_action();
		const char *devpath = get_devpath();
		const char *subsystem = get_subsystem(main_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'", udev.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;
		}

		/* skip blacklisted subsystems */
		if (subsystem_without_dev(subsystem)) {
			dbg("don't care about '%s' devices", subsystem);
			goto exit;
		};

		udev_set_values(&udev, devpath, subsystem);
	}

	/* set signal handlers */
	act.sa_handler = (void (*) (int))sig_handler;
	sigemptyset (&act.sa_mask);
	/* 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);

	/* initialize udev database */
	if (udevdb_init(UDEVDB_DEFAULT) != 0)
		info("error: unable to initialize database, continuing without database");

	switch(act_type) {
	case UDEVSTART:
		dbg("udevstart");
		namedev_init();
		retval = udev_start();
		break;
	case ADD:
		dbg("udev add");

		/* init rules */
		namedev_init();

		/* 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");
			break;
		}
		dbg("opened class_dev->name='%s'", class_dev->name);

		/* name, create node, store in db */
		retval = udev_add_device(&udev, class_dev);
		break;
	case REMOVE:
		dbg("udev remove");
		retval = udev_remove_device(&udev);
	}

	udevdb_exit();

exit:
	logging_close();
	return retval;
}