summaryrefslogtreecommitdiff
path: root/udev-add.c
blob: d20e96ee72e7faeb3ebf9c2799b5035646e679e3 (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
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
/*
 * udev-add.c
 *
 * Userspace devfs
 *
 * Copyright (C) 2003 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 <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <sys/stat.h>

#include "udev.h"
#include "udev_version.h"
#include "namedev.h"
#include "udevdb.h"
#include "libsysfs/libsysfs.h"

/* 
 * Right now the major/minor of a device is stored in a file called
 * "dev" in sysfs.
 * The number is stored as:
 * 	MM:mm
 * 		MM is the major
 * 		mm is the minor
 * 		The value is in decimal.
 */
static int get_major_minor(struct sysfs_class_device *class_dev, int *major, int *minor)
{
	int retval = -ENODEV;

	char *dev;

	dev = sysfs_get_value_from_attributes(class_dev->directory->attributes, "dev");
	if (dev == NULL)
		goto exit;

	dbg("dev = %s", dev);

	if (sscanf(dev, "%u:%u", major, minor) != 2)
		goto exit;

	dbg("found major = %d, minor = %d", *major, *minor);

	retval = 0;
exit:
	return retval;
}

/*
 * we possibly want to add some symlinks here
 * only numeric owner/group id's are supported
 */
static int create_node(struct udevice *dev)
{
	char filename[255];
	int retval = 0;
	uid_t uid = 0;
	gid_t gid = 0;
	dev_t res;

	strncpy(filename, udev_root, sizeof(filename));
	strncat(filename, dev->name, sizeof(filename));

#ifdef __KLIBC__
	res = (dev->major << 8) | (dev->minor);
#else
	res = makedev(dev->major, dev->minor);
#endif

	switch (dev->type) {
	case 'b':
		dev->mode |= S_IFBLK;
		break;
	case 'c':
	case 'u':
		dev->mode |= S_IFCHR;
		break;
	case 'p':
		dev->mode |= S_IFIFO;
		break;
	default:
		dbg("unknown node type %c\n", dev->type);
		return -EINVAL;
	}

	/* create subdirectories if requested */
	if (strchr(dev->name, '/')) {
		char path[255];
		char *pos;
		struct stat stats;

		strncpy(path, filename, sizeof(path));
		pos = strchr(path+1, '/');
		while (1) {
			pos = strchr(pos+1, '/');
			if (pos == NULL)
				break;
			*pos = 0x00;
			if (stat(path, &stats)) {
				retval = mkdir(path, 0755);
				if (retval) {
					dbg("mkdir(%s) failed with error '%s'",
					    path, strerror(errno));
					return retval;
				}
				dbg("created %s", path);
			}
			*pos = '/';
		}
	}

	dbg("mknod(%s, %#o, %u, %u)", filename, dev->mode, dev->major, dev->minor);
	retval = mknod(filename, dev->mode, res);
	if (retval)
		dbg("mknod(%s, %#o, %u, %u) failed with error '%s'",
		    filename, dev->mode, dev->major, dev->minor, strerror(errno));

	if (*dev->owner) {
		char *endptr;
		unsigned long id = strtoul(dev->owner, &endptr, 10);
		if (*endptr == 0x00)
			uid = (uid_t) id;
		else
			dbg("only numeric owner id supported: %s", dev->owner);
	}

	if (*dev->group) {
		char *endptr;
		unsigned long id = strtoul(dev->group, &endptr, 10);
		if (*endptr == 0x00)
			gid = (gid_t) id;
		else
			dbg("only numeric group id supported: %s", dev->group);
	}

	if (uid || gid) {
		dbg("chown(%s, %u, %u)", filename, uid, gid);
		retval = chown(filename, uid, gid);
		if (retval)
			dbg("chown(%s, %u, %u) failed with error '%s'", filename,
			    uid, gid, strerror(errno));
	}

	return retval;
}

static struct sysfs_class_device *get_class_dev(char *device_name)
{
	char dev_path[SYSFS_PATH_MAX];
	struct sysfs_class_device *class_dev = NULL;

	strcpy(dev_path, sysfs_path);
	strcat(dev_path, device_name);

	dbg("looking at %s", dev_path);

	/* open up the sysfs class device for this thing... */
	class_dev = sysfs_open_class_device(dev_path);
	if (class_dev == NULL) {
		dbg ("sysfs_open_class_device failed");
		goto exit;
	}
	dbg("class_dev->name = %s", class_dev->name);

exit:
	return class_dev;
}

/* wait for the "dev" file to show up in the directory in sysfs.
 * If it doesn't happen in about 10 seconds, give up.
 */
#define SECONDS_TO_WAIT_FOR_DEV		10
static int sleep_for_dev(char *path)
{
	char filename[SYSFS_PATH_MAX + 6];
	int loop = SECONDS_TO_WAIT_FOR_DEV;
	int retval;

	strcpy(filename, sysfs_path);
	strcat(filename, path);
	strcat(filename, "/dev");

	while (loop--) {
		struct stat buf;

		dbg("looking for %s", filename);
		retval = stat(filename, &buf);
		if (!retval)
			goto exit;

		/* sleep for a second or two to give the kernel a chance to
		 * create the dev file */
		sleep(1);
	}
	retval = -ENODEV;
exit:
	return retval;
}

int udev_add_device(char *path, char *subsystem)
{
	struct sysfs_class_device *class_dev;
	struct udevice dev;
	int retval = -EINVAL;

	/* for now, the block layer is the only place where block devices are */
	if (strcmp(subsystem, "block") == 0)
		dev.type = 'b';
	else
		dev.type = 'c';

	retval = sleep_for_dev(path);
	if (retval)
		goto exit;

	class_dev = get_class_dev(path);
	if (class_dev == NULL)
		goto exit;

	retval = namedev_name_device(class_dev, &dev);
	if (retval)
		return retval;

	retval = get_major_minor(class_dev, &dev.major, &dev.minor);
	if (retval) {
		dbg("get_major_minor failed");
		goto exit;
	}

//	strcpy(dev.name, attr.name);
//	strcpy(dev.owner, attr.owner);
//	strcpy(dev.group, attr.group);
//	dev.mode = attr.mode;
	
	retval = udevdb_add_dev(path, &dev);
	if (retval != 0)
		dbg("udevdb_add_dev failed, but we are going to try to create the node anyway. "
		    "But remove might not work properly for this device.");

	sysfs_close_class_device(class_dev);

	dbg("name = %s", dev.name);
	retval = create_node(&dev);

exit:
	return retval;
}