aboutsummaryrefslogtreecommitdiffstats
path: root/udev_device.c
blob: bc0b33077e274eedcaf913c11d0d3b27e0112f0d (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
269
270
271
272
/*
 * 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 <stdlib.h>
#include <stdio.h>
#include <stddef.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <ctype.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <net/if.h>
#include <linux/sockios.h>

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


struct udevice *udev_device_init(void)
{
	struct udevice *udev;

	udev = malloc(sizeof(struct udevice));
	if (udev == NULL)
		return NULL;
	memset(udev, 0x00, sizeof(struct udevice));

	INIT_LIST_HEAD(&udev->symlink_list);
	INIT_LIST_HEAD(&udev->run_list);
	INIT_LIST_HEAD(&udev->env_list);

	/* set sysfs device to local storage, can be overridden if needed */
	udev->dev = &udev->dev_local;

	/* default node permissions */
	udev->mode = 0660;
	strcpy(udev->owner, "root");
	strcpy(udev->group, "root");

	return udev;
}

void udev_device_cleanup(struct udevice *udev)
{
	name_list_cleanup(&udev->symlink_list);
	name_list_cleanup(&udev->run_list);
	name_list_cleanup(&udev->env_list);
	free(udev);
}

dev_t udev_device_get_devt(struct udevice *udev)
{
	const char *attr;
	unsigned int maj, min;

	/* read it from sysfs  */
	attr = sysfs_attr_get_value(udev->dev->devpath, "dev");
	if (attr != NULL) {
		if (sscanf(attr, "%u:%u", &maj, &min) == 2)
			return makedev(maj, min);
	}
	return makedev(0, 0);
}

static int rename_netif(struct udevice *udev)
{
	int sk;
	struct ifreq ifr;
	int retval;

	info("changing net interface name from '%s' to '%s'", udev->dev->kernel, udev->name);
	if (udev->test_run)
		return 0;

	sk = socket(PF_INET, SOCK_DGRAM, 0);
	if (sk < 0) {
		err("error opening socket: %s", strerror(errno));
		return -1;
	}

	memset(&ifr, 0x00, sizeof(struct ifreq));
	strlcpy(ifr.ifr_name, udev->dev->kernel, IFNAMSIZ);
	strlcpy(ifr.ifr_newname, udev->name, IFNAMSIZ);
	retval = ioctl(sk, SIOCSIFNAME, &ifr);
	if (retval != 0) {
		int loop;

		/* see if the destination interface name already exists */
		if (errno != EEXIST) {
			err("error changing netif name %s to %s: %s", ifr.ifr_name, ifr.ifr_newname, strerror(errno));
			goto exit;
		}

		/* free our own name, another process may wait for us */
		strlcpy(ifr.ifr_newname, udev->dev->kernel, IFNAMSIZ);
		strlcat(ifr.ifr_newname, "_rename", IFNAMSIZ);
		retval = ioctl(sk, SIOCSIFNAME, &ifr);
		if (retval != 0) {
			err("error changing netif name %s to %s: %s", ifr.ifr_name, ifr.ifr_newname, strerror(errno));
			goto exit;
		}

		/* wait 30 seconds for our target to become available */
		strlcpy(ifr.ifr_name, ifr.ifr_newname, IFNAMSIZ);
		strlcpy(ifr.ifr_newname, udev->name, IFNAMSIZ);
		loop = 30 * 20;
		while (loop--) {
			retval = ioctl(sk, SIOCSIFNAME, &ifr);	
			if (retval != 0) {
				if (errno != EEXIST) {
					err("error changing net interface name %s to %s: %s",
					    ifr.ifr_name, ifr.ifr_newname, strerror(errno));
					break;
				}
				dbg("wait for netif '%s' to become free, loop=%i", udev->name, (30 * 20) - loop);
				usleep(1000 * 1000 / 20);
			}
		}
	}

exit:
	close(sk);
	return retval;
}

int udev_device_event(struct udev_rules *rules, struct udevice *udev)
{
	int retval = 0;

	/* add device node */
	if (major(udev->devt) != 0 &&
	    (strcmp(udev->action, "add") == 0 || strcmp(udev->action, "change") == 0)) {
		struct udevice *udev_old;

		dbg("device node add '%s'", udev->dev->devpath);

		udev_rules_get_name(rules, udev);
		if (udev->ignore_device) {
			info("device event will be ignored");
			goto exit;
		}
		if (udev->name[0] == '\0') {
			info("device node creation supressed");
			goto exit;
		}

		/* read current database entry, we may want to cleanup symlinks */
		udev_old = udev_device_init();
		if (udev_old != NULL) {
			if (udev_db_get_device(udev_old, udev->dev->devpath) != 0) {
				udev_device_cleanup(udev_old);
				udev_old = NULL;
			} else
				info("device '%s' already in database, validate currently present symlinks",
				     udev->dev->devpath);
		}

		/* create node and symlinks */
		retval = udev_node_add(udev, udev_old);
		if (retval == 0) {
			/* store record in database */
			udev_db_add_device(udev);

			/* remove possibly left-over symlinks */
			if (udev_old != NULL) {
				struct name_entry *link_loop;
				struct name_entry *link_old_loop;
				struct name_entry *link_old_tmp_loop;

				/* remove still valid symlinks from old list */
				list_for_each_entry_safe(link_old_loop, link_old_tmp_loop, &udev_old->symlink_list, node)
					list_for_each_entry(link_loop, &udev->symlink_list, node)
						if (strcmp(link_old_loop->name, link_loop->name) == 0) {
							dbg("symlink '%s' still valid, keep it", link_old_loop->name);
							list_del(&link_old_loop->node);
							free(link_old_loop);
						}
				udev_node_remove_symlinks(udev_old);
				udev_device_cleanup(udev_old);
			}
		}
		goto exit;
	}

	/* add netif */
	if (strcmp(udev->dev->subsystem, "net") == 0 && strcmp(udev->action, "add") == 0) {
		dbg("netif add '%s'", udev->dev->devpath);
		udev_rules_get_name(rules, udev);
		if (udev->ignore_device) {
			info("device event will be ignored");
			goto exit;
		}

		/* look if we want to change the name of the netif */
		if (strcmp(udev->name, udev->dev->kernel) != 0) {
			char *pos;

			retval = rename_netif(udev);
			if (retval != 0)
				goto exit;
			info("renamed netif to '%s'", udev->name);

			/* export old name */
			setenv("INTERFACE_OLD", udev->dev->kernel, 1);

			/* now fake the devpath, because the kernel name changed silently */
			pos = strrchr(udev->dev->devpath, '/');
			if (pos != NULL) {
				pos[1] = '\0';
				strlcat(udev->dev->devpath, udev->name, sizeof(udev->dev->devpath));
				strlcpy(udev->dev->kernel, udev->name, sizeof(udev->dev->kernel));
				setenv("DEVPATH", udev->dev->devpath, 1);
				setenv("INTERFACE", udev->name, 1);
			}
		}
		goto exit;
	}

	/* remove device node */
	if (major(udev->devt) != 0 && strcmp(udev->action, "remove") == 0) {
		struct name_entry *name_loop;

		/* import and delete database entry */
		if (udev_db_get_device(udev, udev->dev->devpath) == 0) {
			udev_db_delete_device(udev);
			if (udev->ignore_remove) {
				dbg("remove event for '%s' requested to be ignored by rule", udev->name);
				return 0;
			}
			/* restore stored persistent data */
			list_for_each_entry(name_loop, &udev->env_list, node)
				putenv(name_loop->name);
		} else {
			dbg("'%s' not found in database, using kernel name '%s'", udev->dev->devpath, udev->dev->kernel);
			strlcpy(udev->name, udev->dev->kernel, sizeof(udev->name));
		}

		udev_rules_get_run(rules, udev);
		if (udev->ignore_device) {
			info("device event will be ignored");
			goto exit;
		}

		retval = udev_node_remove(udev);
		goto exit;
	}

	/* default devices */
	udev_rules_get_run(rules, udev);
	if (udev->ignore_device)
		info("device event will be ignored");

exit:
	return retval;
}