nl80211.c 9.46 KB
Newer Older
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
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
/*
 * This is the new netlink-based wireless configuration interface.
 *
 * Copyright 2006, 2007	Johannes Berg <johannes@sipsolutions.net>
 */

#include <linux/if.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/list.h>
#include <linux/if_ether.h>
#include <linux/ieee80211.h>
#include <linux/nl80211.h>
#include <linux/rtnetlink.h>
#include <linux/netlink.h>
#include <net/genetlink.h>
#include <net/cfg80211.h>
#include "core.h"
#include "nl80211.h"

/* the netlink family */
static struct genl_family nl80211_fam = {
	.id = GENL_ID_GENERATE,	/* don't bother with a hardcoded ID */
	.name = "nl80211",	/* have users key off the name instead */
	.hdrsize = 0,		/* no private header */
	.version = 1,		/* no particular meaning now */
	.maxattr = NL80211_ATTR_MAX,
};

/* internal helper: get drv and dev */
static int get_drv_dev_by_info_ifindex(struct genl_info *info,
				       struct cfg80211_registered_device **drv,
				       struct net_device **dev)
{
	int ifindex;

	if (!info->attrs[NL80211_ATTR_IFINDEX])
		return -EINVAL;

	ifindex = nla_get_u32(info->attrs[NL80211_ATTR_IFINDEX]);
	*dev = dev_get_by_index(&init_net, ifindex);
	if (!*dev)
		return -ENODEV;

	*drv = cfg80211_get_dev_from_ifindex(ifindex);
	if (IS_ERR(*drv)) {
		dev_put(*dev);
		return PTR_ERR(*drv);
	}

	return 0;
}

/* policy for the attributes */
static struct nla_policy nl80211_policy[NL80211_ATTR_MAX+1] __read_mostly = {
	[NL80211_ATTR_WIPHY] = { .type = NLA_U32 },
	[NL80211_ATTR_WIPHY_NAME] = { .type = NLA_NUL_STRING,
				      .len = BUS_ID_SIZE-1 },

	[NL80211_ATTR_IFTYPE] = { .type = NLA_U32 },
	[NL80211_ATTR_IFINDEX] = { .type = NLA_U32 },
	[NL80211_ATTR_IFNAME] = { .type = NLA_NUL_STRING, .len = IFNAMSIZ-1 },
};

/* message building helper */
static inline void *nl80211hdr_put(struct sk_buff *skb, u32 pid, u32 seq,
				   int flags, u8 cmd)
{
	/* since there is no private header just add the generic one */
	return genlmsg_put(skb, pid, seq, &nl80211_fam, flags, cmd);
}

/* netlink command implementations */

static int nl80211_send_wiphy(struct sk_buff *msg, u32 pid, u32 seq, int flags,
			      struct cfg80211_registered_device *dev)
{
	void *hdr;

	hdr = nl80211hdr_put(msg, pid, seq, flags, NL80211_CMD_NEW_WIPHY);
	if (!hdr)
		return -1;

	NLA_PUT_U32(msg, NL80211_ATTR_WIPHY, dev->idx);
	NLA_PUT_STRING(msg, NL80211_ATTR_WIPHY_NAME, wiphy_name(&dev->wiphy));
	return genlmsg_end(msg, hdr);

 nla_put_failure:
	return genlmsg_cancel(msg, hdr);
}

static int nl80211_dump_wiphy(struct sk_buff *skb, struct netlink_callback *cb)
{
	int idx = 0;
	int start = cb->args[0];
	struct cfg80211_registered_device *dev;

	mutex_lock(&cfg80211_drv_mutex);
	list_for_each_entry(dev, &cfg80211_drv_list, list) {
		if (++idx < start)
			continue;
		if (nl80211_send_wiphy(skb, NETLINK_CB(cb->skb).pid,
				       cb->nlh->nlmsg_seq, NLM_F_MULTI,
				       dev) < 0)
			break;
	}
	mutex_unlock(&cfg80211_drv_mutex);

	cb->args[0] = idx;

	return skb->len;
}

static int nl80211_get_wiphy(struct sk_buff *skb, struct genl_info *info)
{
	struct sk_buff *msg;
	struct cfg80211_registered_device *dev;

	dev = cfg80211_get_dev_from_info(info);
	if (IS_ERR(dev))
		return PTR_ERR(dev);

	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
	if (!msg)
		goto out_err;

	if (nl80211_send_wiphy(msg, info->snd_pid, info->snd_seq, 0, dev) < 0)
		goto out_free;

	cfg80211_put_dev(dev);

	return genlmsg_unicast(msg, info->snd_pid);

 out_free:
	nlmsg_free(msg);
 out_err:
	cfg80211_put_dev(dev);
	return -ENOBUFS;
}

static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
{
	struct cfg80211_registered_device *rdev;
	int result;

	if (!info->attrs[NL80211_ATTR_WIPHY_NAME])
		return -EINVAL;

	rdev = cfg80211_get_dev_from_info(info);
	if (IS_ERR(rdev))
		return PTR_ERR(rdev);

	result = cfg80211_dev_rename(rdev, nla_data(info->attrs[NL80211_ATTR_WIPHY_NAME]));

	cfg80211_put_dev(rdev);
	return result;
}


static int nl80211_send_iface(struct sk_buff *msg, u32 pid, u32 seq, int flags,
			      struct net_device *dev)
{
	void *hdr;

	hdr = nl80211hdr_put(msg, pid, seq, flags, NL80211_CMD_NEW_INTERFACE);
	if (!hdr)
		return -1;

	NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, dev->ifindex);
	NLA_PUT_STRING(msg, NL80211_ATTR_IFNAME, dev->name);
	/* TODO: interface type */
	return genlmsg_end(msg, hdr);

 nla_put_failure:
	return genlmsg_cancel(msg, hdr);
}

static int nl80211_dump_interface(struct sk_buff *skb, struct netlink_callback *cb)
{
	int wp_idx = 0;
	int if_idx = 0;
	int wp_start = cb->args[0];
	int if_start = cb->args[1];
	struct cfg80211_registered_device *dev;
	struct wireless_dev *wdev;

	mutex_lock(&cfg80211_drv_mutex);
	list_for_each_entry(dev, &cfg80211_drv_list, list) {
		if (++wp_idx < wp_start)
			continue;
		if_idx = 0;

		mutex_lock(&dev->devlist_mtx);
		list_for_each_entry(wdev, &dev->netdev_list, list) {
			if (++if_idx < if_start)
				continue;
			if (nl80211_send_iface(skb, NETLINK_CB(cb->skb).pid,
					       cb->nlh->nlmsg_seq, NLM_F_MULTI,
					       wdev->netdev) < 0)
				break;
		}
		mutex_unlock(&dev->devlist_mtx);
	}
	mutex_unlock(&cfg80211_drv_mutex);

	cb->args[0] = wp_idx;
	cb->args[1] = if_idx;

	return skb->len;
}

static int nl80211_get_interface(struct sk_buff *skb, struct genl_info *info)
{
	struct sk_buff *msg;
	struct cfg80211_registered_device *dev;
	struct net_device *netdev;
	int err;

	err = get_drv_dev_by_info_ifindex(info, &dev, &netdev);
	if (err)
		return err;

	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
	if (!msg)
		goto out_err;

	if (nl80211_send_iface(msg, info->snd_pid, info->snd_seq, 0, netdev) < 0)
		goto out_free;

	dev_put(netdev);
	cfg80211_put_dev(dev);

	return genlmsg_unicast(msg, info->snd_pid);

 out_free:
	nlmsg_free(msg);
 out_err:
	dev_put(netdev);
	cfg80211_put_dev(dev);
	return -ENOBUFS;
}

static int nl80211_set_interface(struct sk_buff *skb, struct genl_info *info)
{
	struct cfg80211_registered_device *drv;
	int err, ifindex;
	enum nl80211_iftype type;
	struct net_device *dev;

	if (info->attrs[NL80211_ATTR_IFTYPE]) {
		type = nla_get_u32(info->attrs[NL80211_ATTR_IFTYPE]);
		if (type > NL80211_IFTYPE_MAX)
			return -EINVAL;
	} else
		return -EINVAL;

	err = get_drv_dev_by_info_ifindex(info, &drv, &dev);
	if (err)
		return err;
	ifindex = dev->ifindex;
	dev_put(dev);

	if (!drv->ops->change_virtual_intf) {
		err = -EOPNOTSUPP;
		goto unlock;
	}

	rtnl_lock();
	err = drv->ops->change_virtual_intf(&drv->wiphy, ifindex, type);
	rtnl_unlock();

 unlock:
	cfg80211_put_dev(drv);
	return err;
}

static int nl80211_new_interface(struct sk_buff *skb, struct genl_info *info)
{
	struct cfg80211_registered_device *drv;
	int err;
	enum nl80211_iftype type = NL80211_IFTYPE_UNSPECIFIED;

	if (!info->attrs[NL80211_ATTR_IFNAME])
		return -EINVAL;

	if (info->attrs[NL80211_ATTR_IFTYPE]) {
		type = nla_get_u32(info->attrs[NL80211_ATTR_IFTYPE]);
		if (type > NL80211_IFTYPE_MAX)
			return -EINVAL;
	}

	drv = cfg80211_get_dev_from_info(info);
	if (IS_ERR(drv))
		return PTR_ERR(drv);

	if (!drv->ops->add_virtual_intf) {
		err = -EOPNOTSUPP;
		goto unlock;
	}

	rtnl_lock();
	err = drv->ops->add_virtual_intf(&drv->wiphy,
		nla_data(info->attrs[NL80211_ATTR_IFNAME]), type);
	rtnl_unlock();

 unlock:
	cfg80211_put_dev(drv);
	return err;
}

static int nl80211_del_interface(struct sk_buff *skb, struct genl_info *info)
{
	struct cfg80211_registered_device *drv;
	int ifindex, err;
	struct net_device *dev;

	err = get_drv_dev_by_info_ifindex(info, &drv, &dev);
	if (err)
		return err;
	ifindex = dev->ifindex;
	dev_put(dev);

	if (!drv->ops->del_virtual_intf) {
		err = -EOPNOTSUPP;
		goto out;
	}

	rtnl_lock();
	err = drv->ops->del_virtual_intf(&drv->wiphy, ifindex);
	rtnl_unlock();

 out:
	cfg80211_put_dev(drv);
	return err;
}

static struct genl_ops nl80211_ops[] = {
	{
		.cmd = NL80211_CMD_GET_WIPHY,
		.doit = nl80211_get_wiphy,
		.dumpit = nl80211_dump_wiphy,
		.policy = nl80211_policy,
		/* can be retrieved by unprivileged users */
	},
	{
		.cmd = NL80211_CMD_SET_WIPHY,
		.doit = nl80211_set_wiphy,
		.policy = nl80211_policy,
		.flags = GENL_ADMIN_PERM,
	},
	{
		.cmd = NL80211_CMD_GET_INTERFACE,
		.doit = nl80211_get_interface,
		.dumpit = nl80211_dump_interface,
		.policy = nl80211_policy,
		/* can be retrieved by unprivileged users */
	},
	{
		.cmd = NL80211_CMD_SET_INTERFACE,
		.doit = nl80211_set_interface,
		.policy = nl80211_policy,
		.flags = GENL_ADMIN_PERM,
	},
	{
		.cmd = NL80211_CMD_NEW_INTERFACE,
		.doit = nl80211_new_interface,
		.policy = nl80211_policy,
		.flags = GENL_ADMIN_PERM,
	},
	{
		.cmd = NL80211_CMD_DEL_INTERFACE,
		.doit = nl80211_del_interface,
		.policy = nl80211_policy,
		.flags = GENL_ADMIN_PERM,
	},
};

/* multicast groups */
static struct genl_multicast_group nl80211_config_mcgrp = {
	.name = "config",
};

/* notification functions */

void nl80211_notify_dev_rename(struct cfg80211_registered_device *rdev)
{
	struct sk_buff *msg;

	msg = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
	if (!msg)
		return;

	if (nl80211_send_wiphy(msg, 0, 0, 0, rdev) < 0) {
		nlmsg_free(msg);
		return;
	}

	genlmsg_multicast(msg, 0, nl80211_config_mcgrp.id, GFP_KERNEL);
}

/* initialisation/exit functions */

int nl80211_init(void)
{
	int err, i;

	err = genl_register_family(&nl80211_fam);
	if (err)
		return err;

	for (i = 0; i < ARRAY_SIZE(nl80211_ops); i++) {
		err = genl_register_ops(&nl80211_fam, &nl80211_ops[i]);
		if (err)
			goto err_out;
	}

	err = genl_register_mc_group(&nl80211_fam, &nl80211_config_mcgrp);
	if (err)
		goto err_out;

	return 0;
 err_out:
	genl_unregister_family(&nl80211_fam);
	return err;
}

void nl80211_exit(void)
{
	genl_unregister_family(&nl80211_fam);
}