aboutsummaryrefslogtreecommitdiff
path: root/drivers/net/wireless/hostap/hostap_80211_tx.c
blob: 6693423f63feb3b032681276af06ed5666e89927 (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
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
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
#include "hostap_80211.h"
#include "hostap_common.h"
#include "hostap_wlan.h"
#include "hostap.h"
#include "hostap_ap.h"

/* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */
/* Ethernet-II snap header (RFC1042 for most EtherTypes) */
static unsigned char rfc1042_header[] =
{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };
/* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */
static unsigned char bridge_tunnel_header[] =
{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 };
/* No encapsulation header if EtherType < 0x600 (=length) */

void hostap_dump_tx_80211(const char *name, struct sk_buff *skb)
{
	struct ieee80211_hdr *hdr;
	u16 fc;

	hdr = (struct ieee80211_hdr *) skb->data;

	printk(KERN_DEBUG "%s: TX len=%d jiffies=%ld\n",
	       name, skb->len, jiffies);

	if (skb->len < 2)
		return;

	fc = le16_to_cpu(hdr->frame_control);
	printk(KERN_DEBUG "   FC=0x%04x (type=%d:%d)%s%s",
	       fc, (fc & IEEE80211_FCTL_FTYPE) >> 2,
	       (fc & IEEE80211_FCTL_STYPE) >> 4,
	       fc & IEEE80211_FCTL_TODS ? " [ToDS]" : "",
	       fc & IEEE80211_FCTL_FROMDS ? " [FromDS]" : "");

	if (skb->len < IEEE80211_DATA_HDR3_LEN) {
		printk("\n");
		return;
	}

	printk(" dur=0x%04x seq=0x%04x\n", le16_to_cpu(hdr->duration_id),
	       le16_to_cpu(hdr->seq_ctrl));

	printk(KERN_DEBUG "   A1=%pM", hdr->addr1);
	printk(" A2=%pM", hdr->addr2);
	printk(" A3=%pM", hdr->addr3);
	if (skb->len >= 30)
		printk(" A4=%pM", hdr->addr4);
	printk("\n");
}


/* hard_start_xmit function for data interfaces (wlan#, wlan#wds#, wlan#sta)
 * Convert Ethernet header into a suitable IEEE 802.11 header depending on
 * device configuration. */
int hostap_data_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct hostap_interface *iface;
	local_info_t *local;
	int need_headroom, need_tailroom = 0;
	struct ieee80211_hdr hdr;
	u16 fc, ethertype = 0;
	enum {
		WDS_NO = 0, WDS_OWN_FRAME, WDS_COMPLIANT_FRAME
	} use_wds = WDS_NO;
	u8 *encaps_data;
	int hdr_len, encaps_len, skip_header_bytes;
	int to_assoc_ap = 0;
	struct hostap_skb_tx_data *meta;

	iface = netdev_priv(dev);
	local = iface->local;

	if (skb->len < ETH_HLEN) {
		printk(KERN_DEBUG "%s: hostap_data_start_xmit: short skb "
		       "(len=%d)\n", dev->name, skb->len);
		kfree_skb(skb);
		return 0;
	}

	if (local->ddev != dev) {
		use_wds = (local->iw_mode == IW_MODE_MASTER &&
			   !(local->wds_type & HOSTAP_WDS_STANDARD_FRAME)) ?
			WDS_OWN_FRAME : WDS_COMPLIANT_FRAME;
		if (dev == local->stadev) {
			to_assoc_ap = 1;
			use_wds = WDS_NO;
		} else if (dev == local->apdev) {
			printk(KERN_DEBUG "%s: prism2_tx: trying to use "
			       "AP device with Ethernet net dev\n", dev->name);
			kfree_skb(skb);
			return 0;
		}
	} else {
		if (local->iw_mode == IW_MODE_REPEAT) {
			printk(KERN_DEBUG "%s: prism2_tx: trying to use "
			       "non-WDS link in Repeater mode\n", dev->name);
			kfree_skb(skb);
			return 0;
		} else if (local->iw_mode == IW_MODE_INFRA &&
			   (local->wds_type & HOSTAP_WDS_AP_CLIENT) &&
			   memcmp(skb->data + ETH_ALEN, dev->dev_addr,
				  ETH_ALEN) != 0) {
			/* AP client mode: send frames with foreign src addr
			 * using 4-addr WDS frames */
			use_wds = WDS_COMPLIANT_FRAME;
		}
	}

	/* Incoming skb->data: dst_addr[6], src_addr[6], proto[2], payload
	 * ==>
	 * Prism2 TX frame with 802.11 header:
	 * txdesc (address order depending on used mode; includes dst_addr and
	 * src_addr), possible encapsulation (RFC1042/Bridge-Tunnel;
	 * proto[2], payload {, possible addr4[6]} */

	ethertype = (skb->data[12] << 8) | skb->data[13];

	memset(&hdr, 0, sizeof(hdr));

	/* Length of data after IEEE 802.11 header */
	encaps_data = NULL;
	encaps_len = 0;
	skip_header_bytes = ETH_HLEN;
	if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
		encaps_data = bridge_tunnel_header;
		encaps_len = sizeof(bridge_tunnel_header);
		skip_header_bytes -= 2;
	} else if (ethertype >= 0x600) {
		encaps_data = rfc1042_header;
		encaps_len = sizeof(rfc1042_header);
		skip_header_bytes -= 2;
	}

	fc = IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA;
	hdr_len = IEEE80211_DATA_HDR3_LEN;

	if (use_wds != WDS_NO) {
		/* Note! Prism2 station firmware has problems with sending real
		 * 802.11 frames with four addresses; until these problems can
		 * be fixed or worked around, 4-addr frames needed for WDS are
		 * using incompatible format: FromDS flag is not set and the
		 * fourth address is added after the frame payload; it is
		 * assumed, that the receiving station knows how to handle this
		 * frame format */

		if (use_wds == WDS_COMPLIANT_FRAME) {
			fc |= IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS;
			/* From&To DS: Addr1 = RA, Addr2 = TA, Addr3 = DA,
			 * Addr4 = SA */
			skb_copy_from_linear_data_offset(skb, ETH_ALEN,
							 &hdr.addr4, ETH_ALEN);
			hdr_len += ETH_ALEN;
		} else {
			/* bogus 4-addr format to workaround Prism2 station
			 * f/w bug */
			fc |= IEEE80211_FCTL_TODS;
			/* From DS: Addr1 = DA (used as RA),
			 * Addr2 = BSSID (used as TA), Addr3 = SA (used as DA),
			 */

			/* SA from skb->data + ETH_ALEN will be added after
			 * frame payload; use hdr.addr4 as a temporary buffer
			 */
			skb_copy_from_linear_data_offset(skb, ETH_ALEN,
							 &hdr.addr4, ETH_ALEN);
			need_tailroom += ETH_ALEN;
		}

		/* send broadcast and multicast frames to broadcast RA, if
		 * configured; otherwise, use unicast RA of the WDS link */
		if ((local->wds_type & HOSTAP_WDS_BROADCAST_RA) &&
		    skb->data[0] & 0x01)
			memset(&hdr.addr1, 0xff, ETH_ALEN);
		else if (iface->type == HOSTAP_INTERFACE_WDS)
			memcpy(&hdr.addr1, iface->u.wds.remote_addr,
			       ETH_ALEN);
		else
			memcpy(&hdr.addr1, local->bssid, ETH_ALEN);
		memcpy(&hdr.addr2, dev->dev_addr, ETH_ALEN);
		skb_copy_from_linear_data(skb, &hdr.addr3, ETH_ALEN);
	} else if (local->iw_mode == IW_MODE_MASTER && !to_assoc_ap) {
		fc |= IEEE80211_FCTL_FROMDS;
		/* From DS: Addr1 = DA, Addr2 = BSSID, Addr3 = SA */
		skb_copy_from_linear_data(skb, &hdr.addr1, ETH_ALEN);
		memcpy(&hdr.addr2, dev->dev_addr, ETH_ALEN);
		skb_copy_from_linear_data_offset(skb, ETH_ALEN, &hdr.addr3,
						 ETH_ALEN);
	} else if (local->iw_mode == IW_MODE_INFRA || to_assoc_ap) {
		fc |= IEEE80211_FCTL_TODS;
		/* To DS: Addr1 = BSSID, Addr2 = SA, Addr3 = DA */
		memcpy(&hdr.addr1, to_assoc_ap ?
		       local->assoc_ap_addr : local->bssid, ETH_ALEN);
		skb_copy_from_linear_data_offset(skb, ETH_ALEN, &hdr.addr2,
						 ETH_ALEN);
		skb_copy_from_linear_data(skb, &hdr.addr3, ETH_ALEN);
	} else if (local->iw_mode == IW_MODE_ADHOC) {
		/* not From/To DS: Addr1 = DA, Addr2 = SA, Addr3 = BSSID */
		skb_copy_from_linear_data(skb, &hdr.addr1, ETH_ALEN);
		skb_copy_from_linear_data_offset(skb, ETH_ALEN, &hdr.addr2,
						 ETH_ALEN);
		memcpy(&hdr.addr3, local->bssid, ETH_ALEN);
	}

	hdr.frame_control = cpu_to_le16(fc);

	skb_pull(skb, skip_header_bytes);
	need_headroom = local->func->need_tx_headroom + hdr_len + encaps_len;
	if (skb_tailroom(skb) < need_tailroom) {
		skb = skb_unshare(skb, GFP_ATOMIC);
		if (skb == NULL) {
			iface->stats.tx_dropped++;
			return 0;
		}
		if (pskb_expand_head(skb, need_headroom, need_tailroom,
				     GFP_ATOMIC)) {
			kfree_skb(skb);
			iface->stats.tx_dropped++;
			return 0;
		}
	} else if (skb_headroom(skb) < need_headroom) {
		struct sk_buff *tmp = skb;
		skb = skb_realloc_headroom(skb, need_headroom);
		kfree_skb(tmp);
		if (skb == NULL) {
			iface->stats.tx_dropped++;
			return 0;
		}
	} else {
		skb = skb_unshare(skb, GFP_ATOMIC);
		if (skb == NULL) {
			iface->stats.tx_dropped++;
			return 0;
		}
	}

	if (encaps_data)
		memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
	memcpy(skb_push(skb, hdr_len), &hdr, hdr_len);
	if (use_wds == WDS_OWN_FRAME) {
		memcpy(skb_put(skb, ETH_ALEN), &hdr.addr4, ETH_ALEN);
	}

	iface->stats.tx_packets++;
	iface->stats.tx_bytes += skb->len;

	skb_reset_mac_header(skb);
	meta = (struct hostap_skb_tx_data *) skb->cb;
	memset(meta, 0, sizeof(*meta));
	meta->magic = HOSTAP_SKB_TX_DATA_MAGIC;
	if (use_wds)
		meta->flags |= HOSTAP_TX_FLAGS_WDS;
	meta->ethertype = ethertype;
	meta->iface = iface;

	/* Send IEEE 802.11 encapsulated frame using the master radio device */
	skb->dev = local->dev;
	dev_queue_xmit(skb);
	return 0;
}


/* hard_start_xmit function for hostapd wlan#ap interfaces */
int hostap_mgmt_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct hostap_interface *iface;
	local_info_t *local;
	struct hostap_skb_tx_data *meta;
	struct ieee80211_hdr *hdr;
	u16 fc;

	iface = netdev_priv(dev);
	local = iface->local;

	if (skb->len < 10) {
		printk(KERN_DEBUG "%s: hostap_mgmt_start_xmit: short skb "
		       "(len=%d)\n", dev->name, skb->len);
		kfree_skb(skb);
		return 0;
	}

	iface->stats.tx_packets++;
	iface->stats.tx_bytes += skb->len;

	meta = (struct hostap_skb_tx_data *) skb->cb;
	memset(meta, 0, sizeof(*meta));
	meta->magic = HOSTAP_SKB_TX_DATA_MAGIC;
	meta->iface = iface;

	if (skb->len >= IEEE80211_DATA_HDR3_LEN + sizeof(rfc1042_header) + 2) {
		hdr = (struct ieee80211_hdr *) skb->data;
		fc = le16_to_cpu(hdr->frame_control);
		if (ieee80211_is_data(hdr->frame_control) &&
		    (fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_DATA) {
			u8 *pos = &skb->data[IEEE80211_DATA_HDR3_LEN +
					     sizeof(rfc1042_header)];
			meta->ethertype = (pos[0] << 8) | pos[1];
		}
	}

	/* Send IEEE 802.11 encapsulated frame using the master radio device */
	skb->dev = local->dev;
	dev_queue_xmit(skb);
	return 0;
}


/* Called only from software IRQ */
static struct sk_buff * hostap_tx_encrypt(struct sk_buff *skb,
					  struct lib80211_crypt_data *crypt)
{
	struct hostap_interface *iface;
	local_info_t *local;
	struct ieee80211_hdr *hdr;
	int prefix_len, postfix_len, hdr_len, res;

	iface = netdev_priv(skb->dev);
	local = iface->local;

	if (skb->len < IEEE80211_DATA_HDR3_LEN) {
		kfree_skb(skb);
		return NULL;
	}

	if (local->tkip_countermeasures &&
	    strcmp(crypt->ops->name, "TKIP") == 0) {
		hdr = (struct ieee80211_hdr *) skb->data;
		if (net_ratelimit()) {
			printk(KERN_DEBUG "%s: TKIP countermeasures: dropped "
			       "TX packet to %pM\n",
			       local->dev->name, hdr->addr1);
		}
		kfree_skb(skb);
		return NULL;
	}

	skb = skb_unshare(skb, GFP_ATOMIC);
	if (skb == NULL)
		return NULL;

	prefix_len = crypt->ops->extra_mpdu_prefix_len +
		crypt->ops->extra_msdu_prefix_len;
	postfix_len = crypt->ops->extra_mpdu_postfix_len +
		crypt->ops->extra_msdu_postfix_len;
	if ((skb_headroom(skb) < prefix_len ||
	     skb_tailroom(skb) < postfix_len) &&
	    pskb_expand_head(skb, prefix_len, postfix_len, GFP_ATOMIC)) {
		kfree_skb(skb);
		return NULL;
	}

	hdr = (struct ieee80211_hdr *) skb->data;
	hdr_len = hostap_80211_get_hdrlen(hdr->frame_control);

	/* Host-based IEEE 802.11 fragmentation for TX is not yet supported, so
	 * call both MSDU and MPDU encryption functions from here. */
	atomic_inc(&crypt->refcnt);
	res = 0;
	if (crypt->ops->encrypt_msdu)
		res = crypt->ops->encrypt_msdu(skb, hdr_len, crypt->priv);
	if (res == 0 && crypt->ops->encrypt_mpdu)
		res = crypt->ops->encrypt_mpdu(skb, hdr_len, crypt->priv);
	atomic_dec(&crypt->refcnt);
	if (res < 0) {
		kfree_skb(skb);
		return NULL;
	}

	return skb;
}


/* hard_start_xmit function for master radio interface wifi#.
 * AP processing (TX rate control, power save buffering, etc.).
 * Use hardware TX function to send the frame. */
int hostap_master_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct hostap_interface *iface;
	local_info_t *local;
	int ret = 1;
	u16 fc;
	struct hostap_tx_data tx;
	ap_tx_ret tx_ret;
	struct hostap_skb_tx_data *meta;
	int no_encrypt = 0;
	struct ieee80211_hdr *hdr;

	iface = netdev_priv(dev);
	local = iface->local;

	tx.skb = skb;
	tx.sta_ptr = NULL;

	meta = (struct hostap_skb_tx_data *) skb->cb;
	if (meta->magic != HOSTAP_SKB_TX_DATA_MAGIC) {
		printk(KERN_DEBUG "%s: invalid skb->cb magic (0x%08x, "
		       "expected 0x%08x)\n",
		       dev->name, meta->magic, HOSTAP_SKB_TX_DATA_MAGIC);
		ret = 0;
		iface->stats.tx_dropped++;
		goto fail;
	}

	if (local->host_encrypt) {
		/* Set crypt to default algorithm and key; will be replaced in
		 * AP code if STA has own alg/key */
		tx.crypt = local->crypt_info.crypt[local->crypt_info.tx_keyidx];
		tx.host_encrypt = 1;
	} else {
		tx.crypt = NULL;
		tx.host_encrypt = 0;
	}

	if (skb->len < 24) {
		printk(KERN_DEBUG "%s: hostap_master_start_xmit: short skb "
		       "(len=%d)\n", dev->name, skb->len);
		ret = 0;
		iface->stats.tx_dropped++;
		goto fail;
	}

	/* FIX (?):
	 * Wi-Fi 802.11b test plan suggests that AP should ignore power save
	 * bit in authentication and (re)association frames and assume tha
	 * STA remains awake for the response. */
	tx_ret = hostap_handle_sta_tx(local, &tx);
	skb = tx.skb;
	meta = (struct hostap_skb_tx_data *) skb->cb;
	hdr = (struct ieee80211_hdr *) skb->data;
	fc = le16_to_cpu(hdr->frame_control);
	switch (tx_ret) {
	case AP_TX_CONTINUE:
		break;
	case AP_TX_CONTINUE_NOT_AUTHORIZED:
		if (local->ieee_802_1x &&
		    ieee80211_is_data(hdr->frame_control) &&
		    meta->ethertype != ETH_P_PAE &&
		    !(meta->flags & HOSTAP_TX_FLAGS_WDS)) {
			printk(KERN_DEBUG "%s: dropped frame to unauthorized "
			       "port (IEEE 802.1X): ethertype=0x%04x\n",
			       dev->name, meta->ethertype);
			hostap_dump_tx_80211(dev->name, skb);

			ret = 0; /* drop packet */
			iface->stats.tx_dropped++;
			goto fail;
		}
		break;
	case AP_TX_DROP:
		ret = 0; /* drop packet */
		iface->stats.tx_dropped++;
		goto fail;
	case AP_TX_RETRY:
		goto fail;
	case AP_TX_BUFFERED:
		/* do not free skb here, it will be freed when the
		 * buffered frame is sent/timed out */
		ret = 0;
		goto tx_exit;
	}

	/* Request TX callback if protocol version is 2 in 802.11 header;
	 * this version 2 is a special case used between hostapd and kernel
	 * driver */
	if (((fc & IEEE80211_FCTL_VERS) == BIT(1)) &&
	    local->ap && local->ap->tx_callback_idx && meta->tx_cb_idx == 0) {
		meta->tx_cb_idx = local->ap->tx_callback_idx;

		/* remove special version from the frame header */
		fc &= ~IEEE80211_FCTL_VERS;
		hdr->frame_control = cpu_to_le16(fc);
	}

	if (!ieee80211_is_data(hdr->frame_control)) {
		no_encrypt = 1;
		tx.crypt = NULL;
	}

	if (local->ieee_802_1x && meta->ethertype == ETH_P_PAE && tx.crypt &&
	    !(fc & IEEE80211_FCTL_PROTECTED)) {
		no_encrypt = 1;
		PDEBUG(DEBUG_EXTRA2, "%s: TX: IEEE 802.1X - passing "
		       "unencrypted EAPOL frame\n", dev->name);
		tx.crypt = NULL; /* no encryption for IEEE 802.1X frames */
	}

	if (tx.crypt && (!tx.crypt->ops || !tx.crypt->ops->encrypt_mpdu))
		tx.crypt = NULL;
	else if ((tx.crypt ||
		 local->crypt_info.crypt[local->crypt_info.tx_keyidx]) &&
		 !no_encrypt) {
		/* Add ISWEP flag both for firmware and host based encryption
		 */
		fc |= IEEE80211_FCTL_PROTECTED;
		hdr->frame_control = cpu_to_le16(fc);
	} else if (local->drop_unencrypted &&
		   ieee80211_is_data(hdr->frame_control) &&
		   meta->ethertype != ETH_P_PAE) {
		if (net_ratelimit()) {
			printk(KERN_DEBUG "%s: dropped unencrypted TX data "
			       "frame (drop_unencrypted=1)\n", dev->name);
		}
		iface->stats.tx_dropped++;
		ret = 0;
		goto fail;
	}

	if (tx.crypt) {
		skb = hostap_tx_encrypt(skb, tx.crypt);
		if (skb == NULL) {
			printk(KERN_DEBUG "%s: TX - encryption failed\n",
			       dev->name);
			ret = 0;
			goto fail;
		}
		meta = (struct hostap_skb_tx_data *) skb->cb;
		if (meta->magic != HOSTAP_SKB_TX_DATA_MAGIC) {
			printk(KERN_DEBUG "%s: invalid skb->cb magic (0x%08x, "
			       "expected 0x%08x) after hostap_tx_encrypt\n",
			       dev->name, meta->magic,
			       HOSTAP_SKB_TX_DATA_MAGIC);
			ret = 0;
			iface->stats.tx_dropped++;
			goto fail;
		}
	}

	if (local->func->tx == NULL || local->func->tx(skb, dev)) {
		ret = 0;
		iface->stats.tx_dropped++;
	} else {
		ret = 0;
		iface->stats.tx_packets++;
		iface->stats.tx_bytes += skb->len;
	}

 fail:
	if (!ret && skb)
		dev_kfree_skb(skb);
 tx_exit:
	if (tx.sta_ptr)
		hostap_handle_sta_release(tx.sta_ptr);
	return ret;
}


EXPORT_SYMBOL(hostap_master_start_xmit);