rx.c 94.3 KB
Newer Older
1 2 3 4
/*
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, Inc.
 * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
5
 * Copyright 2007-2010	Johannes Berg <johannes@sipsolutions.net>
6 7 8 9 10 11
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

12
#include <linux/jiffies.h>
13
#include <linux/slab.h>
14 15 16 17
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
18
#include <linux/rcupdate.h>
19
#include <linux/export.h>
20 21
#include <net/mac80211.h>
#include <net/ieee80211_radiotap.h>
22
#include <asm/unaligned.h>
23 24

#include "ieee80211_i.h"
25
#include "driver-ops.h"
Johannes Berg's avatar
Johannes Berg committed
26
#include "led.h"
27
#include "mesh.h"
28 29 30 31
#include "wep.h"
#include "wpa.h"
#include "tkip.h"
#include "wme.h"
32
#include "rate.h"
33

34 35 36 37 38 39 40
/*
 * monitor mode reception
 *
 * This function cleans up the SKB, i.e. it removes all the stuff
 * only useful for monitoring.
 */
static struct sk_buff *remove_monitor_info(struct ieee80211_local *local,
41
					   struct sk_buff *skb)
42 43 44
{
	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
		if (likely(skb->len > FCS_LEN))
Zhu Yi's avatar
Zhu Yi committed
45
			__pskb_trim(skb, skb->len - FCS_LEN);
46 47 48 49
		else {
			/* driver bug */
			WARN_ON(1);
			dev_kfree_skb(skb);
50
			return NULL;
51 52 53 54 55 56
		}
	}

	return skb;
}

57
static inline int should_drop_frame(struct sk_buff *skb, int present_fcs_len)
58
{
59
	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
60 61
	struct ieee80211_hdr *hdr;

62
	hdr = (void *)(skb->data);
63

64 65 66
	if (status->flag & (RX_FLAG_FAILED_FCS_CRC |
			    RX_FLAG_FAILED_PLCP_CRC |
			    RX_FLAG_AMPDU_IS_ZEROLEN))
67
		return 1;
68
	if (unlikely(skb->len < 16 + present_fcs_len))
69
		return 1;
70 71 72
	if (ieee80211_is_ctl(hdr->frame_control) &&
	    !ieee80211_is_pspoll(hdr->frame_control) &&
	    !ieee80211_is_back_req(hdr->frame_control))
73 74 75 76
		return 1;
	return 0;
}

77
static int
78 79
ieee80211_rx_radiotap_space(struct ieee80211_local *local,
			    struct ieee80211_rx_status *status)
80 81 82 83
{
	int len;

	/* always present fields */
84
	len = sizeof(struct ieee80211_radiotap_header) + 8;
85

86 87 88
	/* allocate extra bitmaps */
	if (status->chains)
		len += 4 * hweight8(status->chains);
89 90 91

	if (ieee80211_have_rx_timestamp(status)) {
		len = ALIGN(len, 8);
92
		len += 8;
93
	}
Johannes Berg's avatar
Johannes Berg committed
94
	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
95 96
		len += 1;

97 98 99 100
	/* antenna field, if we don't have per-chain info */
	if (!status->chains)
		len += 1;

101 102
	/* padding for RX_FLAGS if necessary */
	len = ALIGN(len, 2);
103

104 105 106
	if (status->flag & RX_FLAG_HT) /* HT info */
		len += 3;

107
	if (status->flag & RX_FLAG_AMPDU_DETAILS) {
108
		len = ALIGN(len, 4);
109 110 111
		len += 8;
	}

112 113 114 115 116
	if (status->flag & RX_FLAG_VHT) {
		len = ALIGN(len, 2);
		len += 12;
	}

117 118 119 120 121
	if (status->chains) {
		/* antenna and antenna signal fields */
		len += 2 * hweight8(status->chains);
	}

122 123 124
	return len;
}

125
/*
126 127 128 129 130 131 132 133
 * ieee80211_add_rx_radiotap_header - add radiotap header
 *
 * add a radiotap header containing all the fields which the hardware provided.
 */
static void
ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
				 struct sk_buff *skb,
				 struct ieee80211_rate *rate,
134
				 int rtap_len, bool has_fcs)
135
{
136
	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
137 138
	struct ieee80211_radiotap_header *rthdr;
	unsigned char *pos;
139 140
	__le32 *it_present;
	u32 it_present_val;
141
	u16 rx_flags = 0;
142
	u16 channel_flags = 0;
143 144
	int mpdulen, chain;
	unsigned long chains = status->chains;
145 146 147 148

	mpdulen = skb->len;
	if (!(has_fcs && (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)))
		mpdulen += FCS_LEN;
149 150 151

	rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
	memset(rthdr, 0, rtap_len);
152
	it_present = &rthdr->it_present;
153 154

	/* radiotap header, set always present flags */
155
	rthdr->it_len = cpu_to_le16(rtap_len);
156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171
	it_present_val = BIT(IEEE80211_RADIOTAP_FLAGS) |
			 BIT(IEEE80211_RADIOTAP_CHANNEL) |
			 BIT(IEEE80211_RADIOTAP_RX_FLAGS);

	if (!status->chains)
		it_present_val |= BIT(IEEE80211_RADIOTAP_ANTENNA);

	for_each_set_bit(chain, &chains, IEEE80211_MAX_CHAINS) {
		it_present_val |=
			BIT(IEEE80211_RADIOTAP_EXT) |
			BIT(IEEE80211_RADIOTAP_RADIOTAP_NAMESPACE);
		put_unaligned_le32(it_present_val, it_present);
		it_present++;
		it_present_val = BIT(IEEE80211_RADIOTAP_ANTENNA) |
				 BIT(IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
	}
172

173 174 175 176
	put_unaligned_le32(it_present_val, it_present);

	pos = (void *)(it_present + 1);

177 178 179
	/* the order of the following fields is important */

	/* IEEE80211_RADIOTAP_TSFT */
180
	if (ieee80211_have_rx_timestamp(status)) {
181 182 183
		/* padding */
		while ((pos - (u8 *)rthdr) & 7)
			*pos++ = 0;
184 185 186 187
		put_unaligned_le64(
			ieee80211_calculate_rx_timestamp(local, status,
							 mpdulen, 0),
			pos);
188
		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
189 190 191 192
		pos += 8;
	}

	/* IEEE80211_RADIOTAP_FLAGS */
193
	if (has_fcs && (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS))
194
		*pos |= IEEE80211_RADIOTAP_F_FCS;
Johannes Berg's avatar
Johannes Berg committed
195 196
	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
		*pos |= IEEE80211_RADIOTAP_F_BADFCS;
197 198
	if (status->flag & RX_FLAG_SHORTPRE)
		*pos |= IEEE80211_RADIOTAP_F_SHORTPRE;
199 200 201
	pos++;

	/* IEEE80211_RADIOTAP_RATE */
202
	if (!rate || status->flag & (RX_FLAG_HT | RX_FLAG_VHT)) {
203
		/*
204
		 * Without rate information don't add it. If we have,
205
		 * MCS information is a separate field in radiotap,
206 207
		 * added below. The byte here is needed as padding
		 * for the channel though, so initialise it to 0.
208 209
		 */
		*pos = 0;
210
	} else {
211
		int shift = 0;
212
		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_RATE);
213 214 215 216 217
		if (status->flag & RX_FLAG_10MHZ)
			shift = 1;
		else if (status->flag & RX_FLAG_5MHZ)
			shift = 2;
		*pos = DIV_ROUND_UP(rate->bitrate, 5 * (1 << shift));
218
	}
219 220 221
	pos++;

	/* IEEE80211_RADIOTAP_CHANNEL */
222
	put_unaligned_le16(status->freq, pos);
223
	pos += 2;
224 225 226 227 228
	if (status->flag & RX_FLAG_10MHZ)
		channel_flags |= IEEE80211_CHAN_HALF;
	else if (status->flag & RX_FLAG_5MHZ)
		channel_flags |= IEEE80211_CHAN_QUARTER;

229
	if (status->band == IEEE80211_BAND_5GHZ)
230
		channel_flags |= IEEE80211_CHAN_OFDM | IEEE80211_CHAN_5GHZ;
231
	else if (status->flag & (RX_FLAG_HT | RX_FLAG_VHT))
232
		channel_flags |= IEEE80211_CHAN_DYN | IEEE80211_CHAN_2GHZ;
233
	else if (rate && rate->flags & IEEE80211_RATE_ERP_G)
234
		channel_flags |= IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ;
235
	else if (rate)
236
		channel_flags |= IEEE80211_CHAN_OFDM | IEEE80211_CHAN_2GHZ;
237
	else
238 239
		channel_flags |= IEEE80211_CHAN_2GHZ;
	put_unaligned_le16(channel_flags, pos);
240 241 242
	pos += 2;

	/* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
243 244
	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM &&
	    !(status->flag & RX_FLAG_NO_SIGNAL_VAL)) {
245 246 247 248 249 250 251 252
		*pos = status->signal;
		rthdr->it_present |=
			cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
		pos++;
	}

	/* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */

253 254 255 256 257
	if (!status->chains) {
		/* IEEE80211_RADIOTAP_ANTENNA */
		*pos = status->antenna;
		pos++;
	}
258 259 260 261 262

	/* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */

	/* IEEE80211_RADIOTAP_RX_FLAGS */
	/* ensure 2 byte alignment for the 2 byte field as required */
263
	if ((pos - (u8 *)rthdr) & 1)
264
		*pos++ = 0;
Johannes Berg's avatar
Johannes Berg committed
265
	if (status->flag & RX_FLAG_FAILED_PLCP_CRC)
266 267
		rx_flags |= IEEE80211_RADIOTAP_F_RX_BADPLCP;
	put_unaligned_le16(rx_flags, pos);
268
	pos += 2;
269 270

	if (status->flag & RX_FLAG_HT) {
271 272
		unsigned int stbc;

273
		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_MCS);
274
		*pos++ = local->hw.radiotap_mcs_details;
275 276 277 278 279
		*pos = 0;
		if (status->flag & RX_FLAG_SHORT_GI)
			*pos |= IEEE80211_RADIOTAP_MCS_SGI;
		if (status->flag & RX_FLAG_40MHZ)
			*pos |= IEEE80211_RADIOTAP_MCS_BW_40;
280 281
		if (status->flag & RX_FLAG_HT_GF)
			*pos |= IEEE80211_RADIOTAP_MCS_FMT_GF;
282 283
		stbc = (status->flag & RX_FLAG_STBC_MASK) >> RX_FLAG_STBC_SHIFT;
		*pos |= stbc << IEEE80211_RADIOTAP_MCS_STBC_SHIFT;
284 285 286
		pos++;
		*pos++ = status->rate_idx;
	}
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

	if (status->flag & RX_FLAG_AMPDU_DETAILS) {
		u16 flags = 0;

		/* ensure 4 byte alignment */
		while ((pos - (u8 *)rthdr) & 3)
			pos++;
		rthdr->it_present |=
			cpu_to_le32(1 << IEEE80211_RADIOTAP_AMPDU_STATUS);
		put_unaligned_le32(status->ampdu_reference, pos);
		pos += 4;
		if (status->flag & RX_FLAG_AMPDU_REPORT_ZEROLEN)
			flags |= IEEE80211_RADIOTAP_AMPDU_REPORT_ZEROLEN;
		if (status->flag & RX_FLAG_AMPDU_IS_ZEROLEN)
			flags |= IEEE80211_RADIOTAP_AMPDU_IS_ZEROLEN;
		if (status->flag & RX_FLAG_AMPDU_LAST_KNOWN)
			flags |= IEEE80211_RADIOTAP_AMPDU_LAST_KNOWN;
		if (status->flag & RX_FLAG_AMPDU_IS_LAST)
			flags |= IEEE80211_RADIOTAP_AMPDU_IS_LAST;
		if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_ERROR)
			flags |= IEEE80211_RADIOTAP_AMPDU_DELIM_CRC_ERR;
		if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_KNOWN)
			flags |= IEEE80211_RADIOTAP_AMPDU_DELIM_CRC_KNOWN;
		put_unaligned_le16(flags, pos);
		pos += 2;
		if (status->flag & RX_FLAG_AMPDU_DELIM_CRC_KNOWN)
			*pos++ = status->ampdu_delimiter_crc;
		else
			*pos++ = 0;
		*pos++ = 0;
	}
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
	if (status->flag & RX_FLAG_VHT) {
		u16 known = local->hw.radiotap_vht_details;

		rthdr->it_present |= cpu_to_le32(1 << IEEE80211_RADIOTAP_VHT);
		/* known field - how to handle 80+80? */
		if (status->flag & RX_FLAG_80P80MHZ)
			known &= ~IEEE80211_RADIOTAP_VHT_KNOWN_BANDWIDTH;
		put_unaligned_le16(known, pos);
		pos += 2;
		/* flags */
		if (status->flag & RX_FLAG_SHORT_GI)
			*pos |= IEEE80211_RADIOTAP_VHT_FLAG_SGI;
		pos++;
		/* bandwidth */
		if (status->flag & RX_FLAG_80MHZ)
			*pos++ = 4;
		else if (status->flag & RX_FLAG_80P80MHZ)
			*pos++ = 0; /* marked not known above */
		else if (status->flag & RX_FLAG_160MHZ)
			*pos++ = 11;
		else if (status->flag & RX_FLAG_40MHZ)
			*pos++ = 1;
		else /* 20 MHz */
			*pos++ = 0;
		/* MCS/NSS */
		*pos = (status->rate_idx << 4) | status->vht_nss;
		pos += 4;
		/* coding field */
		pos++;
		/* group ID */
		pos++;
		/* partial_aid */
		pos += 2;
	}

354 355 356 357
	for_each_set_bit(chain, &chains, IEEE80211_MAX_CHAINS) {
		*pos++ = status->chain_signal[chain];
		*pos++ = chain;
	}
358 359
}

360 361 362 363 364 365 366
/*
 * This function copies a received frame to all monitor interfaces and
 * returns a cleaned-up SKB that no longer includes the FCS nor the
 * radiotap header the driver might have added.
 */
static struct sk_buff *
ieee80211_rx_monitor(struct ieee80211_local *local, struct sk_buff *origskb,
367
		     struct ieee80211_rate *rate)
368
{
369
	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(origskb);
370
	struct ieee80211_sub_if_data *sdata;
371
	int needed_headroom;
372 373 374 375 376 377 378 379 380 381 382 383
	struct sk_buff *skb, *skb2;
	struct net_device *prev_dev = NULL;
	int present_fcs_len = 0;

	/*
	 * First, we may need to make a copy of the skb because
	 *  (1) we need to modify it for radiotap (if not present), and
	 *  (2) the other RX handlers will modify the skb we got.
	 *
	 * We don't need to, of course, if we aren't going to return
	 * the SKB because it has a bad FCS/PLCP checksum.
	 */
384

385 386 387
	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
		present_fcs_len = FCS_LEN;

388 389
	/* ensure hdr->frame_control is in skb head */
	if (!pskb_may_pull(origskb, 2)) {
Zhu Yi's avatar
Zhu Yi committed
390 391 392 393
		dev_kfree_skb(origskb);
		return NULL;
	}

394
	if (!local->monitors) {
395
		if (should_drop_frame(origskb, present_fcs_len)) {
396 397 398 399
			dev_kfree_skb(origskb);
			return NULL;
		}

400
		return remove_monitor_info(local, origskb);
401 402
	}

403 404 405
	/* room for the radiotap header based on driver features */
	needed_headroom = ieee80211_rx_radiotap_space(local, status);

406
	if (should_drop_frame(origskb, present_fcs_len)) {
407 408 409 410 411 412 413 414 415 416 417 418
		/* only need to expand headroom if necessary */
		skb = origskb;
		origskb = NULL;

		/*
		 * This shouldn't trigger often because most devices have an
		 * RX header they pull before we get here, and that should
		 * be big enough for our radiotap information. We should
		 * probably export the length to drivers so that we can have
		 * them allocate enough headroom to start with.
		 */
		if (skb_headroom(skb) < needed_headroom &&
419
		    pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
420 421 422 423 424 425 426 427 428 429
			dev_kfree_skb(skb);
			return NULL;
		}
	} else {
		/*
		 * Need to make a copy and possibly remove radiotap header
		 * and FCS from the original.
		 */
		skb = skb_copy_expand(origskb, needed_headroom, 0, GFP_ATOMIC);

430
		origskb = remove_monitor_info(local, origskb);
431 432 433 434 435

		if (!skb)
			return origskb;
	}

436
	/* prepend radiotap information */
437 438
	ieee80211_add_rx_radiotap_header(local, skb, rate, needed_headroom,
					 true);
439

440
	skb_reset_mac_header(skb);
441 442 443 444 445
	skb->ip_summed = CHECKSUM_UNNECESSARY;
	skb->pkt_type = PACKET_OTHERHOST;
	skb->protocol = htons(ETH_P_802_2);

	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
446
		if (sdata->vif.type != NL80211_IFTYPE_MONITOR)
447 448
			continue;

449 450 451
		if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
			continue;

452
		if (!ieee80211_sdata_running(sdata))
453 454
			continue;

455 456 457 458
		if (prev_dev) {
			skb2 = skb_clone(skb, GFP_ATOMIC);
			if (skb2) {
				skb2->dev = prev_dev;
459
				netif_receive_skb(skb2);
460 461 462 463 464 465 466 467 468 469
			}
		}

		prev_dev = sdata->dev;
		sdata->dev->stats.rx_packets++;
		sdata->dev->stats.rx_bytes += skb->len;
	}

	if (prev_dev) {
		skb->dev = prev_dev;
470
		netif_receive_skb(skb);
471 472 473 474 475 476
	} else
		dev_kfree_skb(skb);

	return origskb;
}

477
static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
478
{
479
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
480
	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
481
	int tid, seqno_idx, security_idx;
482 483

	/* does the frame have a qos control field? */
484 485
	if (ieee80211_is_data_qos(hdr->frame_control)) {
		u8 *qc = ieee80211_get_qos_ctl(hdr);
486
		/* frame has qos control */
487
		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
488
		if (*qc & IEEE80211_QOS_CTL_A_MSDU_PRESENT)
489
			status->rx_flags |= IEEE80211_RX_AMSDU;
490 491 492

		seqno_idx = tid;
		security_idx = tid;
493
	} else {
494 495 496 497 498 499 500 501 502 503 504
		/*
		 * IEEE 802.11-2007, 7.1.3.4.1 ("Sequence Number field"):
		 *
		 *	Sequence numbers for management frames, QoS data
		 *	frames with a broadcast/multicast address in the
		 *	Address 1 field, and all non-QoS data frames sent
		 *	by QoS STAs are assigned using an additional single
		 *	modulo-4096 counter, [...]
		 *
		 * We also use that counter for non-QoS STAs.
		 */
505
		seqno_idx = IEEE80211_NUM_TIDS;
506 507
		security_idx = 0;
		if (ieee80211_is_mgmt(hdr->frame_control))
508
			security_idx = IEEE80211_NUM_TIDS;
509
		tid = 0;
510
	}
511

512 513
	rx->seqno_idx = seqno_idx;
	rx->security_idx = security_idx;
514 515 516
	/* Set skb->priority to 1d tag if highest order bit of TID is not set.
	 * For now, set skb->priority to 0 for other cases. */
	rx->skb->priority = (tid > 7) ? 0 : tid;
517
}
518

519 520 521 522 523 524 525 526 527 528 529
/**
 * DOC: Packet alignment
 *
 * Drivers always need to pass packets that are aligned to two-byte boundaries
 * to the stack.
 *
 * Additionally, should, if possible, align the payload data in a way that
 * guarantees that the contained IP header is aligned to a four-byte
 * boundary. In the case of regular frames, this simply means aligning the
 * payload to a four-byte boundary (because either the IP header is directly
 * contained, or IV/RFC1042 headers that have a length divisible by four are
530 531 532
 * in front of it).  If the payload data is not properly aligned and the
 * architecture doesn't support efficient unaligned operations, mac80211
 * will align the data.
533 534 535 536 537 538 539
 *
 * With A-MSDU frames, however, the payload data address must yield two modulo
 * four because there are 14-byte 802.3 headers within the A-MSDU frames that
 * push the IP header further back to a multiple of four again. Thankfully, the
 * specs were sane enough this time around to require padding each A-MSDU
 * subframe to a length that is a multiple of four.
 *
Lucas De Marchi's avatar
Lucas De Marchi committed
540
 * Padding like Atheros hardware adds which is between the 802.11 header and
541 542 543 544
 * the payload is not supported, the driver is required to move the 802.11
 * header to be directly in front of the payload in that case.
 */
static void ieee80211_verify_alignment(struct ieee80211_rx_data *rx)
545
{
546 547 548
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
	WARN_ONCE((unsigned long)rx->skb->data & 1,
		  "unaligned packet at 0x%p\n", rx->skb->data);
549
#endif
550 551
}

552

553 554
/* rx handlers */

555 556 557 558
static int ieee80211_is_unicast_robust_mgmt_frame(struct sk_buff *skb)
{
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;

559
	if (is_multicast_ether_addr(hdr->addr1))
560 561
		return 0;

562
	return ieee80211_is_robust_mgmt_frame(skb);
563 564 565 566 567 568 569
}


static int ieee80211_is_multicast_robust_mgmt_frame(struct sk_buff *skb)
{
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;

570
	if (!is_multicast_ether_addr(hdr->addr1))
571 572
		return 0;

573
	return ieee80211_is_robust_mgmt_frame(skb);
574 575 576 577 578 579 580 581 582
}


/* Get the BIP key index from MMIE; return -1 if this is not a BIP frame */
static int ieee80211_get_mmie_keyidx(struct sk_buff *skb)
{
	struct ieee80211_mgmt *hdr = (struct ieee80211_mgmt *) skb->data;
	struct ieee80211_mmie *mmie;

583
	if (skb->len < 24 + sizeof(*mmie) || !is_multicast_ether_addr(hdr->da))
584 585
		return -1;

586
	if (!ieee80211_is_robust_mgmt_frame(skb))
587 588 589 590 591 592 593 594 595 596 597
		return -1; /* not a robust management frame */

	mmie = (struct ieee80211_mmie *)
		(skb->data + skb->len - sizeof(*mmie));
	if (mmie->element_id != WLAN_EID_MMIE ||
	    mmie->length != sizeof(*mmie) - 2)
		return -1;

	return le16_to_cpu(mmie->key_id);
}

598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618
static int iwl80211_get_cs_keyid(const struct ieee80211_cipher_scheme *cs,
				 struct sk_buff *skb)
{
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
	__le16 fc;
	int hdrlen;
	u8 keyid;

	fc = hdr->frame_control;
	hdrlen = ieee80211_hdrlen(fc);

	if (skb->len < hdrlen + cs->hdr_len)
		return -EINVAL;

	skb_copy_bits(skb, hdrlen + cs->key_idx_off, &keyid, 1);
	keyid &= cs->key_idx_mask;
	keyid >>= cs->key_idx_shift;

	return keyid;
}

619
static ieee80211_rx_result ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
620
{
621
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
622
	char *dev_addr = rx->sdata->vif.addr;
623

624
	if (ieee80211_is_data(hdr->frame_control)) {
625 626
		if (is_multicast_ether_addr(hdr->addr1)) {
			if (ieee80211_has_tods(hdr->frame_control) ||
627
			    !ieee80211_has_fromds(hdr->frame_control))
628
				return RX_DROP_MONITOR;
629
			if (ether_addr_equal(hdr->addr3, dev_addr))
630 631 632 633
				return RX_DROP_MONITOR;
		} else {
			if (!ieee80211_has_a4(hdr->frame_control))
				return RX_DROP_MONITOR;
634
			if (ether_addr_equal(hdr->addr4, dev_addr))
635 636
				return RX_DROP_MONITOR;
		}
637 638 639 640 641 642
	}

	/* If there is not an established peer link and this is not a peer link
	 * establisment frame, beacon or probe, drop the frame.
	 */

643
	if (!rx->sta || sta_plink_state(rx->sta) != NL80211_PLINK_ESTAB) {
644
		struct ieee80211_mgmt *mgmt;
645

646
		if (!ieee80211_is_mgmt(hdr->frame_control))
647 648
			return RX_DROP_MONITOR;

649
		if (ieee80211_is_action(hdr->frame_control)) {
650
			u8 category;
651 652 653 654 655

			/* make sure category field is present */
			if (rx->skb->len < IEEE80211_MIN_ACTION_SIZE)
				return RX_DROP_MONITOR;

656
			mgmt = (struct ieee80211_mgmt *)hdr;
657 658
			category = mgmt->u.action.category;
			if (category != WLAN_CATEGORY_MESH_ACTION &&
659
			    category != WLAN_CATEGORY_SELF_PROTECTED)
660 661 662 663
				return RX_DROP_MONITOR;
			return RX_CONTINUE;
		}

664 665
		if (ieee80211_is_probe_req(hdr->frame_control) ||
		    ieee80211_is_probe_resp(hdr->frame_control) ||
666 667
		    ieee80211_is_beacon(hdr->frame_control) ||
		    ieee80211_is_auth(hdr->frame_control))
668 669 670 671 672
			return RX_CONTINUE;

		return RX_DROP_MONITOR;
	}

Johannes Berg's avatar
Johannes Berg committed
673 674
	return RX_CONTINUE;
}
675

676
static void ieee80211_release_reorder_frame(struct ieee80211_sub_if_data *sdata,
677
					    struct tid_ampdu_rx *tid_agg_rx,
678 679
					    int index,
					    struct sk_buff_head *frames)
680 681
{
	struct sk_buff *skb = tid_agg_rx->reorder_buf[index];
682
	struct ieee80211_rx_status *status;
683

684 685
	lockdep_assert_held(&tid_agg_rx->reorder_lock);

686 687 688
	if (!skb)
		goto no_frame;

689
	/* release the frame from the reorder ring buffer */
690 691
	tid_agg_rx->stored_mpdu_num--;
	tid_agg_rx->reorder_buf[index] = NULL;
692 693
	status = IEEE80211_SKB_RXCB(skb);
	status->rx_flags |= IEEE80211_RX_DEFERRED_RELEASE;
694
	__skb_queue_tail(frames, skb);
695 696

no_frame:
697
	tid_agg_rx->head_seq_num = ieee80211_sn_inc(tid_agg_rx->head_seq_num);
698 699
}

700
static void ieee80211_release_reorder_frames(struct ieee80211_sub_if_data *sdata,
701
					     struct tid_ampdu_rx *tid_agg_rx,
702 703
					     u16 head_seq_num,
					     struct sk_buff_head *frames)
704 705 706
{
	int index;

707 708
	lockdep_assert_held(&tid_agg_rx->reorder_lock);

709
	while (ieee80211_sn_less(tid_agg_rx->head_seq_num, head_seq_num)) {
710
		index = tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
711 712
		ieee80211_release_reorder_frame(sdata, tid_agg_rx, index,
						frames);
713 714 715 716 717 718 719 720 721
	}
}

/*
 * Timeout (in jiffies) for skb's that are waiting in the RX reorder buffer. If
 * the skb was added to the buffer longer than this time ago, the earlier
 * frames that have not yet been received are assumed to be lost and the skb
 * can be released for processing. This may also release other skb's from the
 * reorder buffer if there are no additional gaps between the frames.
722 723
 *
 * Callers must hold tid_agg_rx->reorder_lock.
724 725 726
 */
#define HT_RX_REORDER_BUF_TIMEOUT (HZ / 10)

727
static void ieee80211_sta_reorder_release(struct ieee80211_sub_if_data *sdata,
728 729
					  struct tid_ampdu_rx *tid_agg_rx,
					  struct sk_buff_head *frames)
730
{
731
	int index, j;
732

733 734
	lockdep_assert_held(&tid_agg_rx->reorder_lock);

735
	/* release the buffer until next missing frame */
736
	index = tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
737
	if (!tid_agg_rx->reorder_buf[index] &&
738
	    tid_agg_rx->stored_mpdu_num) {
739 740 741 742 743 744 745 746 747 748 749
		/*
		 * No buffers ready to be released, but check whether any
		 * frames in the reorder buffer have timed out.
		 */
		int skipped = 1;
		for (j = (index + 1) % tid_agg_rx->buf_size; j != index;
		     j = (j + 1) % tid_agg_rx->buf_size) {
			if (!tid_agg_rx->reorder_buf[j]) {
				skipped++;
				continue;
			}
750 751
			if (skipped &&
			    !time_after(jiffies, tid_agg_rx->reorder_time[j] +
752
					HT_RX_REORDER_BUF_TIMEOUT))
753
				goto set_release_timer;
754

Johannes Berg's avatar
Johannes Berg committed
755 756
			ht_dbg_ratelimited(sdata,
					   "release an RX reorder frame due to timeout on earlier frames\n");
757 758
			ieee80211_release_reorder_frame(sdata, tid_agg_rx, j,
							frames);
759 760 761 762 763

			/*
			 * Increment the head seq# also for the skipped slots.
			 */
			tid_agg_rx->head_seq_num =
764 765
				(tid_agg_rx->head_seq_num +
				 skipped) & IEEE80211_SN_MASK;
766 767 768
			skipped = 0;
		}
	} else while (tid_agg_rx->reorder_buf[index]) {
769 770
		ieee80211_release_reorder_frame(sdata, tid_agg_rx, index,
						frames);
771
		index =	tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
772
	}
773 774

	if (tid_agg_rx->stored_mpdu_num) {
775
		j = index = tid_agg_rx->head_seq_num % tid_agg_rx->buf_size;
776 777 778 779 780 781 782 783 784 785

		for (; j != (index - 1) % tid_agg_rx->buf_size;
		     j = (j + 1) % tid_agg_rx->buf_size) {
			if (tid_agg_rx->reorder_buf[j])
				break;
		}

 set_release_timer:

		mod_timer(&tid_agg_rx->reorder_timer,
786
			  tid_agg_rx->reorder_time[j] + 1 +
787 788 789 790
			  HT_RX_REORDER_BUF_TIMEOUT);
	} else {
		del_timer(&tid_agg_rx->reorder_timer);
	}
791 792
}

793 794 795 796 797
/*
 * As this function belongs to the RX path it must be under
 * rcu_read_lock protection. It returns false if the frame
 * can be processed immediately, true if it was consumed.
 */
798
static bool ieee80211_sta_manage_reorder_buf(struct ieee80211_sub_if_data *sdata,
799
					     struct tid_ampdu_rx *tid_agg_rx,
800 801
					     struct sk_buff *skb,
					     struct sk_buff_head *frames)
802 803 804 805 806 807
{
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
	u16 sc = le16_to_cpu(hdr->seq_ctrl);
	u16 mpdu_seq_num = (sc & IEEE80211_SCTL_SEQ) >> 4;
	u16 head_seq_num, buf_size;
	int index;
808
	bool ret = true;
809

810 811
	spin_lock(&tid_agg_rx->reorder_lock);

812 813 814 815
	buf_size = tid_agg_rx->buf_size;
	head_seq_num = tid_agg_rx->head_seq_num;

	/* frame with out of date sequence number */
816
	if (ieee80211_sn_less(mpdu_seq_num, head_seq_num)) {
817
		dev_kfree_skb(skb);
818
		goto out;
819 820 821 822 823 824
	}

	/*
	 * If frame the sequence number exceeds our buffering window
	 * size release some previous frames to make room for this one.
	 */
825 826 827
	if (!ieee80211_sn_less(mpdu_seq_num, head_seq_num + buf_size)) {
		head_seq_num = ieee80211_sn_inc(
				ieee80211_sn_sub(mpdu_seq_num, buf_size));
828
		/* release stored frames up to new head to stack */
829
		ieee80211_release_reorder_frames(sdata, tid_agg_rx,
830
						 head_seq_num, frames);
831 832 833 834
	}

	/* Now the new frame is always in the range of the reordering buffer */

835
	index = mpdu_seq_num % tid_agg_rx->buf_size;
836 837 838 839

	/* check if we already stored this frame */
	if (tid_agg_rx->reorder_buf[index]) {
		dev_kfree_skb(skb);
840
		goto out;
841 842 843 844 845
	}

	/*
	 * If the current MPDU is in the right order and nothing else
	 * is stored we can process it directly, no need to buffer it.
846 847
	 * If it is first but there's something stored, we may be able
	 * to release frames after this one.
848 849 850
	 */
	if (mpdu_seq_num == tid_agg_rx->head_seq_num &&
	    tid_agg_rx->stored_mpdu_num == 0) {
851 852
		tid_agg_rx->head_seq_num =
			ieee80211_sn_inc(tid_agg_rx->head_seq_num);
853 854
		ret = false;
		goto out;
855 856 857 858 859 860
	}

	/* put the frame in the reordering buffer */
	tid_agg_rx->reorder_buf[index] = skb;
	tid_agg_rx->reorder_time[index] = jiffies;
	tid_agg_rx->stored_mpdu_num++;
861
	ieee80211_sta_reorder_release(sdata, tid_agg_rx, frames);
862

863 864 865
 out:
	spin_unlock(&tid_agg_rx->reorder_lock);
	return ret;
866 867 868 869 870 871
}

/*
 * Reorder MPDUs from A-MPDUs, keeping them on a buffer. Returns
 * true if the MPDU was buffered, false if it should be processed.
 */
872 873
static void ieee80211_rx_reorder_ampdu(struct ieee80211_rx_data *rx,
				       struct sk_buff_head *frames)
874
{
875 876
	struct sk_buff *skb = rx->skb;
	struct ieee80211_local *local = rx->local;
877
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
878
	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
879
	struct sta_info *sta = rx->sta;
880 881
	struct tid_ampdu_rx *tid_agg_rx;
	u16 sc;
882
	u8 tid, ack_policy;
883

884 885
	if (!ieee80211_is_data_qos(hdr->frame_control) ||
	    is_multicast_ether_addr(hdr->addr1))
886
		goto dont_reorder;
887 888 889 890 891 892 893

	/*
	 * filter the QoS data rx stream according to
	 * STA/TID and check if this STA/TID is on aggregation
	 */

	if (!sta)
894
		goto dont_reorder;
895

896 897
	ack_policy = *ieee80211_get_qos_ctl(hdr) &
		     IEEE80211_QOS_CTL_ACK_POLICY_MASK;
898 899
	tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;

900 901 902
	tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]);
	if (!tid_agg_rx)
		goto dont_reorder;
903 904 905

	/* qos null data frames are excluded */
	if (unlikely(hdr->frame_control & cpu_to_le16(IEEE80211_STYPE_NULLFUNC)))
906
		goto dont_reorder;
907

908 909 910 911 912
	/* not part of a BA session */
	if (ack_policy != IEEE80211_QOS_CTL_ACK_POLICY_BLOCKACK &&
	    ack_policy != IEEE80211_QOS_CTL_ACK_POLICY_NORMAL)
		goto dont_reorder;

913 914 915 916
	/* not actually part of this BA session */
	if (!(status->rx_flags & IEEE80211_RX_RA_MATCH))
		goto dont_reorder;

917 918 919 920
	/* new, potentially un-ordered, ampdu frame - process it */

	/* reset session timer */
	if (tid_agg_rx->timeout)
921
		tid_agg_rx->last_rx = jiffies;
922 923 924 925

	/* if this mpdu is fragmented - terminate rx aggregation session */
	sc = le16_to_cpu(hdr->seq_ctrl);
	if (sc & IEEE80211_SCTL_FRAG) {
926
		skb->pkt_type = IEEE80211_SDATA_QUEUE_TYPE_FRAME;
927 928
		skb_queue_tail(&rx->sdata->skb_queue, skb);
		ieee80211_queue_work(&local->hw, &rx->sdata->work);
929
		return;
930 931
	}

932 933 934 935 936 937 938
	/*
	 * No locking needed -- we will only ever process one
	 * RX packet at a time, and thus own tid_agg_rx. All
	 * other code manipulating it needs to (and does) make
	 * sure that we cannot get to it any more before doing
	 * anything with it.
	 */
939 940
	if (ieee80211_sta_manage_reorder_buf(rx->sdata, tid_agg_rx, skb,
					     frames))
941 942 943
		return;

 dont_reorder:
944
	__skb_queue_tail(frames, skb);
945
}
946

947
static ieee80211_rx_result debug_noinline
948
ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
949
{
950
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
951
	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
952

953 954 955 956 957 958 959 960
	/*
	 * Drop duplicate 802.11 retransmissions
	 * (IEEE 802.11-2012: 9.3.2.10 "Duplicate detection and recovery")
	 */
	if (rx->skb->len >= 24 && rx->sta &&
	    !ieee80211_is_ctl(hdr->frame_control) &&
	    !ieee80211_is_qos_nullfunc(hdr->frame_control) &&
	    !is_multicast_ether_addr(hdr->addr1)) {
961
		if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
962
			     rx->sta->last_seq_ctrl[rx->seqno_idx] ==
963
			     hdr->seq_ctrl)) {
964
			if (status->rx_flags & IEEE80211_RX_RA_MATCH) {
965 966 967
				rx->local->dot11FrameDuplicateCount++;
				rx->sta->num_duplicates++;
			}
968
			return RX_DROP_UNUSABLE;
969
		} else if (!(status->flag & RX_FLAG_AMSDU_MORE)) {
970
			rx->sta->last_seq_ctrl[rx->seqno_idx] = hdr->seq_ctrl;
971
		}
972 973 974 975
	}

	if (unlikely(rx->skb->len < 16)) {
		I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
Johannes Berg's avatar
Johannes Berg committed
976
		return RX_DROP_MONITOR;
977 978 979 980 981
	}

	/* Drop disallowed frame classes based on STA auth/assoc state;
	 * IEEE 802.11, Chap 5.5.
	 *
982 983
	 * mac80211 filters only based on association state, i.e. it drops
	 * Class 3 frames from not associated stations. hostapd sends
984 985 986
	 * deauth/disassoc frames when needed. In addition, hostapd is
	 * responsible for filtering on both auth and assoc states.
	 */
987

Johannes Berg's avatar
Johannes Berg committed
988
	if (ieee80211_vif_is_mesh(&rx->sdata->vif))
989 990
		return ieee80211_rx_mesh_check(rx);

991 992
	if (unlikely((ieee80211_is_data(hdr->frame_control) ||
		      ieee80211_is_pspoll(hdr->frame_control)) &&
993
		     rx->sdata->vif.type != NL80211_IFTYPE_ADHOC &&
Bill Jordan's avatar
Bill Jordan committed
994
		     rx->sdata->vif.type != NL80211_IFTYPE_WDS &&
995
		     (!rx->sta || !test_sta_flag(rx->sta, WLAN_STA_ASSOC)))) {
996 997 998 999 1000 1001
		/*
		 * accept port control frames from the AP even when it's not
		 * yet marked ASSOC to prevent a race where we don't set the
		 * assoc bit quickly enough before it sends the first frame
		 */
		if (rx->sta && rx->sdata->vif.type == NL80211_IFTYPE_STATION &&
1002
		    ieee80211_is_data_present(hdr->frame_control)) {
1003 1004 1005 1006 1007 1008 1009 1010