1/*
2 * Copyright (C) 2003-2004 Greg Kroah-Hartman <greg@kroah.com>
3 * Copyright (C) 2004-2006 Kay Sievers <kay.sievers@vrfy.org>
4 *
5 *	This program is free software; you can redistribute it and/or modify it
6 *	under the terms of the GNU General Public License as published by the
7 *	Free Software Foundation version 2 of the License.
8 *
9 *	This program is distributed in the hope that it will be useful, but
10 *	WITHOUT ANY WARRANTY; without even the implied warranty of
11 *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12 *	General Public License for more details.
13 *
14 *	You should have received a copy of the GNU General Public License along
15 *	with this program; if not, write to the Free Software Foundation, Inc.,
16 *	51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
17 *
18 */
19
20#include <stdio.h>
21#include <stddef.h>
22#include <stdlib.h>
23#include <string.h>
24#include <fcntl.h>
25#include <ctype.h>
26#include <errno.h>
27#include <signal.h>
28#include <unistd.h>
29#include <syslog.h>
30
31#include "udev.h"
32#include "udev_rules.h"
33#include "udev_selinux.h"
34
35#ifdef USE_LOG
36void log_message(int priority, const char *format, ...)
37{
38	va_list args;
39
40	if (priority > udev_log_priority)
41		return;
42
43	va_start(args, format);
44	vsyslog(priority, format, args);
45	va_end(args);
46}
47#endif
48
49static void asmlinkage sig_handler(int signum)
50{
51	switch (signum) {
52		case SIGALRM:
53			exit(1);
54		case SIGINT:
55		case SIGTERM:
56			exit(20 + signum);
57	}
58}
59
60int main(int argc, char *argv[], char *envp[])
61{
62	struct sysfs_device *dev;
63	struct udevice *udev;
64	const char *maj, *min;
65	struct udev_rules rules;
66	const char *action;
67	const char *devpath;
68	const char *subsystem;
69	struct sigaction act;
70	int devnull;
71	int retval = -EINVAL;
72
73	if (argc == 2 && strcmp(argv[1], "-V") == 0) {
74		printf("%s\n", UDEV_VERSION);
75		exit(0);
76	}
77
78	/* set std fd's to /dev/null, /sbin/hotplug forks us, we don't have them at all */
79	devnull = open("/dev/null", O_RDWR);
80	if (devnull >= 0)  {
81		if (devnull != STDIN_FILENO)
82			dup2(devnull, STDIN_FILENO);
83		if (devnull != STDOUT_FILENO)
84			dup2(devnull, STDOUT_FILENO);
85		if (devnull != STDERR_FILENO)
86			dup2(devnull, STDERR_FILENO);
87		if (devnull > STDERR_FILENO)
88			close(devnull);
89	}
90
91	logging_init("udev");
92	if (devnull < 0)
93		err("open /dev/null failed: %s", strerror(errno));
94	udev_config_init();
95	selinux_init();
96	dbg("version %s", UDEV_VERSION);
97
98	/* set signal handlers */
99	memset(&act, 0x00, sizeof(act));
100	act.sa_handler = (void (*)(int)) sig_handler;
101	sigemptyset (&act.sa_mask);
102	act.sa_flags = 0;
103	sigaction(SIGALRM, &act, NULL);
104	sigaction(SIGINT, &act, NULL);
105	sigaction(SIGTERM, &act, NULL);
106
107	/* trigger timeout to prevent hanging processes */
108	alarm(UDEV_ALARM_TIMEOUT);
109
110	action = getenv("ACTION");
111	devpath = getenv("DEVPATH");
112	subsystem = getenv("SUBSYSTEM");
113	/* older kernels passed the SUBSYSTEM only as argument */
114	if (subsystem == NULL && argc == 2)
115		subsystem = argv[1];
116
117	if (action == NULL || subsystem == NULL || devpath == NULL) {
118		err("action, subsystem or devpath missing");
119		goto exit;
120	}
121
122	/* export log_priority , as called programs may want to do the same as udev */
123	if (udev_log_priority) {
124		char priority[32];
125
126		sprintf(priority, "%i", udev_log_priority);
127		setenv("UDEV_LOG", priority, 1);
128	}
129
130	sysfs_init();
131	udev_rules_init(&rules, 0);
132
133	dev = sysfs_device_get(devpath);
134	if (dev == NULL) {
135		info("unable to open '%s'", devpath);
136		goto fail;
137	}
138
139	udev = udev_device_init(NULL);
140	if (udev == NULL)
141		goto fail;
142
143	/* override built-in sysfs device */
144	udev->dev = dev;
145	strlcpy(udev->action, action, sizeof(udev->action));
146
147	/* get dev_t from environment, which is needed for "remove" to work, "add" works also from sysfs */
148	maj = getenv("MAJOR");
149	min = getenv("MINOR");
150	if (maj != NULL && min != NULL)
151		udev->devt = makedev(atoi(maj), atoi(min));
152	else
153		udev->devt = udev_device_get_devt(udev);
154
155	retval = udev_device_event(&rules, udev);
156
157	if (retval == 0 && !udev->ignore_device && udev_run) {
158		struct name_entry *name_loop;
159
160		dbg("executing run list");
161		list_for_each_entry(name_loop, &udev->run_list, node) {
162			if (strncmp(name_loop->name, "socket:", strlen("socket:")) == 0)
163				pass_env_to_socket(&name_loop->name[strlen("socket:")], devpath, action);
164			else {
165				char program[PATH_SIZE];
166
167				strlcpy(program, name_loop->name, sizeof(program));
168				udev_rules_apply_format(udev, program, sizeof(program));
169				run_program(program, udev->dev->subsystem, NULL, 0, NULL, (udev_log_priority >= LOG_INFO));
170			}
171		}
172	}
173
174	udev_device_cleanup(udev);
175fail:
176	udev_rules_cleanup(&rules);
177	sysfs_cleanup();
178	selinux_exit();
179
180exit:
181	logging_close();
182	if (retval != 0)
183		return 1;
184	return 0;
185}
186