rx.c 59 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11
/*
 * Copyright 2002-2005, Instant802 Networks, Inc.
 * Copyright 2005-2006, Devicescape Software, Inc.
 * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
 * Copyright 2007	Johannes Berg <johannes@sipsolutions.net>
 *
 * 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 14 15 16
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
17
#include <linux/rcupdate.h>
18 19 20 21
#include <net/mac80211.h>
#include <net/ieee80211_radiotap.h>

#include "ieee80211_i.h"
Johannes Berg's avatar
Johannes Berg committed
22
#include "led.h"
23
#include "mesh.h"
24 25 26 27 28
#include "wep.h"
#include "wpa.h"
#include "tkip.h"
#include "wme.h"

29 30 31 32
u8 ieee80211_sta_manage_reorder_buf(struct ieee80211_hw *hw,
				struct tid_ampdu_rx *tid_agg_rx,
				struct sk_buff *skb, u16 mpdu_seq_num,
				int bar_req);
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
/*
 * 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,
					   struct sk_buff *skb,
					   int rtap_len)
{
	skb_pull(skb, rtap_len);

	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS) {
		if (likely(skb->len > FCS_LEN))
			skb_trim(skb, skb->len - FCS_LEN);
		else {
			/* driver bug */
			WARN_ON(1);
			dev_kfree_skb(skb);
			skb = NULL;
		}
	}

	return skb;
}

static inline int should_drop_frame(struct ieee80211_rx_status *status,
				    struct sk_buff *skb,
				    int present_fcs_len,
				    int radiotap_len)
{
64
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
65 66 67 68 69

	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
		return 1;
	if (unlikely(skb->len < 16 + present_fcs_len + radiotap_len))
		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 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
static int
ieee80211_rx_radiotap_len(struct ieee80211_local *local,
			  struct ieee80211_rx_status *status)
{
	int len;

	/* always present fields */
	len = sizeof(struct ieee80211_radiotap_header) + 9;

	if (status->flag & RX_FLAG_TSFT)
		len += 8;
	if (local->hw.flags & IEEE80211_HW_SIGNAL_DB ||
	    local->hw.flags & IEEE80211_HW_SIGNAL_DBM)
		len += 1;
	if (local->hw.flags & IEEE80211_HW_NOISE_DBM)
		len += 1;

	if (len & 1) /* padding for RX_FLAGS if necessary */
		len++;

	/* make sure radiotap starts at a naturally aligned address */
	if (len % 8)
		len = roundup(len, 8);

	return len;
}

/**
 * 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_rx_status *status,
				 struct ieee80211_rate *rate,
				 int rtap_len)
{
	struct ieee80211_radiotap_header *rthdr;
	unsigned char *pos;

	rthdr = (struct ieee80211_radiotap_header *)skb_push(skb, rtap_len);
	memset(rthdr, 0, rtap_len);

	/* radiotap header, set always present flags */
	rthdr->it_present =
		cpu_to_le32((1 << IEEE80211_RADIOTAP_FLAGS) |
			    (1 << IEEE80211_RADIOTAP_RATE) |
			    (1 << IEEE80211_RADIOTAP_CHANNEL) |
			    (1 << IEEE80211_RADIOTAP_ANTENNA) |
			    (1 << IEEE80211_RADIOTAP_RX_FLAGS));
	rthdr->it_len = cpu_to_le16(rtap_len);

	pos = (unsigned char *)(rthdr+1);

	/* the order of the following fields is important */

	/* IEEE80211_RADIOTAP_TSFT */
	if (status->flag & RX_FLAG_TSFT) {
		*(__le64 *)pos = cpu_to_le64(status->mactime);
		rthdr->it_present |=
			cpu_to_le32(1 << IEEE80211_RADIOTAP_TSFT);
		pos += 8;
	}

	/* IEEE80211_RADIOTAP_FLAGS */
	if (local->hw.flags & IEEE80211_HW_RX_INCLUDES_FCS)
		*pos |= IEEE80211_RADIOTAP_F_FCS;
	pos++;

	/* IEEE80211_RADIOTAP_RATE */
	*pos = rate->bitrate / 5;
	pos++;

	/* IEEE80211_RADIOTAP_CHANNEL */
	*(__le16 *)pos = cpu_to_le16(status->freq);
	pos += 2;
	if (status->band == IEEE80211_BAND_5GHZ)
		*(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_OFDM |
					     IEEE80211_CHAN_5GHZ);
	else
		*(__le16 *)pos = cpu_to_le16(IEEE80211_CHAN_DYN |
					     IEEE80211_CHAN_2GHZ);
	pos += 2;

	/* IEEE80211_RADIOTAP_DBM_ANTSIGNAL */
	if (local->hw.flags & IEEE80211_HW_SIGNAL_DBM) {
		*pos = status->signal;
		rthdr->it_present |=
			cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL);
		pos++;
	}

	/* IEEE80211_RADIOTAP_DBM_ANTNOISE */
	if (local->hw.flags & IEEE80211_HW_NOISE_DBM) {
		*pos = status->noise;
		rthdr->it_present |=
			cpu_to_le32(1 << IEEE80211_RADIOTAP_DBM_ANTNOISE);
		pos++;
	}

	/* IEEE80211_RADIOTAP_LOCK_QUALITY is missing */

	/* IEEE80211_RADIOTAP_ANTENNA */
	*pos = status->antenna;
	pos++;

	/* IEEE80211_RADIOTAP_DB_ANTSIGNAL */
	if (local->hw.flags & IEEE80211_HW_SIGNAL_DB) {
		*pos = status->signal;
		rthdr->it_present |=
			cpu_to_le32(1 << IEEE80211_RADIOTAP_DB_ANTSIGNAL);
		pos++;
	}

	/* IEEE80211_RADIOTAP_DB_ANTNOISE is not used */

	/* IEEE80211_RADIOTAP_RX_FLAGS */
	/* ensure 2 byte alignment for the 2 byte field as required */
	if ((pos - (unsigned char *)rthdr) & 1)
		pos++;
	/* FIXME: when radiotap gets a 'bad PLCP' flag use it here */
	if (status->flag & (RX_FLAG_FAILED_FCS_CRC | RX_FLAG_FAILED_PLCP_CRC))
		*(__le16 *)pos |= cpu_to_le16(IEEE80211_RADIOTAP_F_RX_BADFCS);
	pos += 2;
}

205 206 207 208 209 210 211
/*
 * 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,
212 213
		     struct ieee80211_rx_status *status,
		     struct ieee80211_rate *rate)
214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232
{
	struct ieee80211_sub_if_data *sdata;
	int needed_headroom = 0;
	struct sk_buff *skb, *skb2;
	struct net_device *prev_dev = NULL;
	int present_fcs_len = 0;
	int rtap_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.
	 */
	if (status->flag & RX_FLAG_RADIOTAP)
		rtap_len = ieee80211_get_radiotap_len(origskb->data);
	else
233 234
		/* room for the radiotap header based on driver features */
		needed_headroom = ieee80211_rx_radiotap_len(local, status);
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

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

	if (!local->monitors) {
		if (should_drop_frame(status, origskb, present_fcs_len,
				      rtap_len)) {
			dev_kfree_skb(origskb);
			return NULL;
		}

		return remove_monitor_info(local, origskb, rtap_len);
	}

	if (should_drop_frame(status, origskb, present_fcs_len, rtap_len)) {
		/* 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 &&
262
		    pskb_expand_head(skb, needed_headroom, 0, GFP_ATOMIC)) {
263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279
			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);

		origskb = remove_monitor_info(local, origskb, rtap_len);

		if (!skb)
			return origskb;
	}

	/* if necessary, prepend radiotap information */
280 281 282
	if (!(status->flag & RX_FLAG_RADIOTAP))
		ieee80211_add_rx_radiotap_header(local, skb, status, rate,
						 needed_headroom);
283

284
	skb_reset_mac_header(skb);
285 286 287 288 289 290 291 292
	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) {
		if (!netif_running(sdata->dev))
			continue;

293
		if (sdata->vif.type != IEEE80211_IF_TYPE_MNTR)
294 295
			continue;

296 297 298
		if (sdata->u.mntr_flags & MONITOR_FLAG_COOK_FRAMES)
			continue;

299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321
		if (prev_dev) {
			skb2 = skb_clone(skb, GFP_ATOMIC);
			if (skb2) {
				skb2->dev = prev_dev;
				netif_rx(skb2);
			}
		}

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

	if (prev_dev) {
		skb->dev = prev_dev;
		netif_rx(skb);
	} else
		dev_kfree_skb(skb);

	return origskb;
}


322
static void ieee80211_parse_qos(struct ieee80211_rx_data *rx)
323
{
324
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
325 326 327
	int tid;

	/* does the frame have a qos control field? */
328 329
	if (ieee80211_is_data_qos(hdr->frame_control)) {
		u8 *qc = ieee80211_get_qos_ctl(hdr);
330
		/* frame has qos control */
331 332
		tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
		if (*qc & IEEE80211_QOS_CONTROL_A_MSDU_PRESENT)
333
			rx->flags |= IEEE80211_RX_AMSDU;
334
		else
335
			rx->flags &= ~IEEE80211_RX_AMSDU;
336
	} else {
337 338 339 340 341 342 343 344 345 346 347 348
		/*
		 * 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.
		 */
		tid = NUM_RX_DATA_QUEUES - 1;
349
	}
350

351
	rx->queue = tid;
352 353 354
	/* 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;
355
}
356

357
static void ieee80211_verify_ip_alignment(struct ieee80211_rx_data *rx)
358 359
{
#ifdef CONFIG_MAC80211_DEBUG_PACKET_ALIGNMENT
360
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
361 362
	int hdrlen;

363
	if (!ieee80211_is_data_present(hdr->frame_control))
364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384
		return;

	/*
	 * Drivers are required to 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 in front of it.
	 *
	 * 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.
	 *
	 * Padding like atheros hardware adds which is inbetween the 802.11
	 * header and the payload is not supported, the driver is required
	 * to move the 802.11 header further back in that case.
	 */
385
	hdrlen = ieee80211_hdrlen(hdr->frame_control);
386
	if (rx->flags & IEEE80211_RX_AMSDU)
387 388 389
		hdrlen += ETH_HLEN;
	WARN_ON_ONCE(((unsigned long)(rx->skb->data + hdrlen)) & 3);
#endif
390 391
}

392

393 394
/* rx handlers */

395
static ieee80211_rx_result debug_noinline
396
ieee80211_rx_h_passive_scan(struct ieee80211_rx_data *rx)
397 398 399 400
{
	struct ieee80211_local *local = rx->local;
	struct sk_buff *skb = rx->skb;

Zhu Yi's avatar
Zhu Yi committed
401
	if (unlikely(local->sta_hw_scanning))
402
		return ieee80211_sta_rx_scan(rx->dev, skb, rx->status);
Zhu Yi's avatar
Zhu Yi committed
403 404 405

	if (unlikely(local->sta_sw_scanning)) {
		/* drop all the other packets during a software scan anyway */
406
		if (ieee80211_sta_rx_scan(rx->dev, skb, rx->status)
407
		    != RX_QUEUED)
Zhu Yi's avatar
Zhu Yi committed
408
			dev_kfree_skb(skb);
409
		return RX_QUEUED;
410 411
	}

412
	if (unlikely(rx->flags & IEEE80211_RX_IN_SCAN)) {
413 414
		/* scanning finished during invoking of handlers */
		I802_DEBUG_INC(local->rx_handlers_drop_passive_scan);
Johannes Berg's avatar
Johannes Berg committed
415
		return RX_DROP_UNUSABLE;
416 417
	}

418
	return RX_CONTINUE;
419 420
}

421
static ieee80211_rx_result
422
ieee80211_rx_mesh_check(struct ieee80211_rx_data *rx)
423
{
424 425
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
	unsigned int hdrlen = ieee80211_hdrlen(hdr->frame_control);
426

427 428
	if (ieee80211_is_data(hdr->frame_control)) {
		if (!ieee80211_has_a4(hdr->frame_control))
429 430 431 432 433 434 435 436 437
			return RX_DROP_MONITOR;
		if (memcmp(hdr->addr4, rx->dev->dev_addr, ETH_ALEN) == 0)
			return RX_DROP_MONITOR;
	}

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

438
	if (!rx->sta || sta_plink_state(rx->sta) != PLINK_ESTAB) {
439
		struct ieee80211_mgmt *mgmt;
440

441
		if (!ieee80211_is_mgmt(hdr->frame_control))
442 443
			return RX_DROP_MONITOR;

444
		if (ieee80211_is_action(hdr->frame_control)) {
445 446 447 448 449 450
			mgmt = (struct ieee80211_mgmt *)hdr;
			if (mgmt->u.action.category != PLINK_CATEGORY)
				return RX_DROP_MONITOR;
			return RX_CONTINUE;
		}

451 452 453 454 455 456 457 458 459 460 461 462 463 464
		if (ieee80211_is_probe_req(hdr->frame_control) ||
		    ieee80211_is_probe_resp(hdr->frame_control) ||
		    ieee80211_is_beacon(hdr->frame_control))
			return RX_CONTINUE;

		return RX_DROP_MONITOR;

	}

#define msh_h_get(h, l) ((struct ieee80211s_hdr *) ((u8 *)h + l))

	if (ieee80211_is_data(hdr->frame_control) &&
	    is_multicast_ether_addr(hdr->addr1) &&
	    mesh_rmc_check(hdr->addr4, msh_h_get(hdr, hdrlen), rx->dev))
465
		return RX_DROP_MONITOR;
Johannes Berg's avatar
Johannes Berg committed
466
#undef msh_h_get
467

Johannes Berg's avatar
Johannes Berg committed
468 469
	return RX_CONTINUE;
}
470 471


472
static ieee80211_rx_result debug_noinline
473
ieee80211_rx_h_check(struct ieee80211_rx_data *rx)
474
{
475
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
476 477 478

	/* Drop duplicate 802.11 retransmissions (IEEE 802.11 Chap. 9.2.9) */
	if (rx->sta && !is_multicast_ether_addr(hdr->addr1)) {
479
		if (unlikely(ieee80211_has_retry(hdr->frame_control) &&
480
			     rx->sta->last_seq_ctrl[rx->queue] ==
481
			     hdr->seq_ctrl)) {
482
			if (rx->flags & IEEE80211_RX_RA_MATCH) {
483 484 485
				rx->local->dot11FrameDuplicateCount++;
				rx->sta->num_duplicates++;
			}
Johannes Berg's avatar
Johannes Berg committed
486
			return RX_DROP_MONITOR;
487
		} else
488
			rx->sta->last_seq_ctrl[rx->queue] = hdr->seq_ctrl;
489 490 491 492
	}

	if (unlikely(rx->skb->len < 16)) {
		I802_DEBUG_INC(rx->local->rx_handlers_drop_short);
Johannes Berg's avatar
Johannes Berg committed
493
		return RX_DROP_MONITOR;
494 495 496 497 498 499 500 501 502 503
	}

	/* Drop disallowed frame classes based on STA auth/assoc state;
	 * IEEE 802.11, Chap 5.5.
	 *
	 * 80211.o does filtering only based on association state, i.e., it
	 * drops Class 3 frames from not associated stations. hostapd sends
	 * deauth/disassoc frames when needed. In addition, hostapd is
	 * responsible for filtering on both auth and assoc states.
	 */
504

Johannes Berg's avatar
Johannes Berg committed
505
	if (ieee80211_vif_is_mesh(&rx->sdata->vif))
506 507
		return ieee80211_rx_mesh_check(rx);

508 509
	if (unlikely((ieee80211_is_data(hdr->frame_control) ||
		      ieee80211_is_pspoll(hdr->frame_control)) &&
510
		     rx->sdata->vif.type != IEEE80211_IF_TYPE_IBSS &&
511
		     (!rx->sta || !test_sta_flags(rx->sta, WLAN_STA_ASSOC)))) {
512 513 514 515
		if ((!ieee80211_has_fromds(hdr->frame_control) &&
		     !ieee80211_has_tods(hdr->frame_control) &&
		     ieee80211_is_data(hdr->frame_control)) ||
		    !(rx->flags & IEEE80211_RX_RA_MATCH)) {
516 517
			/* Drop IBSS frames and frames for other hosts
			 * silently. */
Johannes Berg's avatar
Johannes Berg committed
518
			return RX_DROP_MONITOR;
519 520
		}

Johannes Berg's avatar
Johannes Berg committed
521
		return RX_DROP_MONITOR;
522 523
	}

524
	return RX_CONTINUE;
525 526 527
}


528
static ieee80211_rx_result debug_noinline
529
ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
530
{
531
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
532 533
	int keyidx;
	int hdrlen;
Johannes Berg's avatar
Johannes Berg committed
534
	ieee80211_rx_result result = RX_DROP_UNUSABLE;
535
	struct ieee80211_key *stakey = NULL;
536

537 538 539 540 541 542 543 544 545 546 547 548 549 550 551
	/*
	 * Key selection 101
	 *
	 * There are three types of keys:
	 *  - GTK (group keys)
	 *  - PTK (pairwise keys)
	 *  - STK (station-to-station pairwise keys)
	 *
	 * When selecting a key, we have to distinguish between multicast
	 * (including broadcast) and unicast frames, the latter can only
	 * use PTKs and STKs while the former always use GTKs. Unless, of
	 * course, actual WEP keys ("pre-RSNA") are used, then unicast
	 * frames can also use key indizes like GTKs. Hence, if we don't
	 * have a PTK/STK we check the key index for a WEP key.
	 *
552 553 554 555
	 * Note that in a regular BSS, multicast frames are sent by the
	 * AP only, associated stations unicast the frame to the AP first
	 * which then multicasts it on their behalf.
	 *
556 557
	 * There is also a slight problem in IBSS mode: GTKs are negotiated
	 * with each station, that is something we don't currently handle.
558 559 560
	 * The spec seems to expect that one negotiates the same key with
	 * every station but there's no such requirement; VLANs could be
	 * possible.
561 562
	 */

563
	if (!ieee80211_has_protected(hdr->frame_control))
564
		return RX_CONTINUE;
565

566
	/*
567
	 * No point in finding a key and decrypting if the frame is neither
568 569
	 * addressed to us nor a multicast frame.
	 */
570
	if (!(rx->flags & IEEE80211_RX_RA_MATCH))
571
		return RX_CONTINUE;
572

573 574 575 576 577
	if (rx->sta)
		stakey = rcu_dereference(rx->sta->key);

	if (!is_multicast_ether_addr(hdr->addr1) && stakey) {
		rx->key = stakey;
578
	} else {
579 580 581 582 583 584 585 586 587
		/*
		 * The device doesn't give us the IV so we won't be
		 * able to look up the key. That's ok though, we
		 * don't need to decrypt the frame, we just won't
		 * be able to keep statistics accurate.
		 * Except for key threshold notifications, should
		 * we somehow allow the driver to tell us which key
		 * the hardware used if this flag is set?
		 */
588 589
		if ((rx->status->flag & RX_FLAG_DECRYPTED) &&
		    (rx->status->flag & RX_FLAG_IV_STRIPPED))
590
			return RX_CONTINUE;
591

592
		hdrlen = ieee80211_hdrlen(hdr->frame_control);
593 594

		if (rx->skb->len < 8 + hdrlen)
Johannes Berg's avatar
Johannes Berg committed
595
			return RX_DROP_UNUSABLE; /* TODO: count this? */
596 597 598 599 600 601 602

		/*
		 * no need to call ieee80211_wep_get_keyidx,
		 * it verifies a bunch of things we've done already
		 */
		keyidx = rx->skb->data[hdrlen + 3] >> 6;

603
		rx->key = rcu_dereference(rx->sdata->keys[keyidx]);
604 605 606 607 608 609

		/*
		 * RSNA-protected unicast frames should always be sent with
		 * pairwise or station-to-station keys, but for WEP we allow
		 * using a key index as well.
		 */
610
		if (rx->key && rx->key->conf.alg != ALG_WEP &&
611 612
		    !is_multicast_ether_addr(hdr->addr1))
			rx->key = NULL;
613 614
	}

615
	if (rx->key) {
616
		rx->key->tx_rx_count++;
617
		/* TODO: add threshold stuff again */
618
	} else {
Johannes Berg's avatar
Johannes Berg committed
619
		return RX_DROP_MONITOR;
620 621
	}

622 623
	/* Check for weak IVs if possible */
	if (rx->sta && rx->key->conf.alg == ALG_WEP &&
624
	    ieee80211_is_data(hdr->frame_control) &&
625 626
	    (!(rx->status->flag & RX_FLAG_IV_STRIPPED) ||
	     !(rx->status->flag & RX_FLAG_DECRYPTED)) &&
627 628 629
	    ieee80211_wep_is_weak_iv(rx->skb, rx->key))
		rx->sta->wep_weak_iv_count++;

630 631
	switch (rx->key->conf.alg) {
	case ALG_WEP:
632 633
		result = ieee80211_crypto_wep_decrypt(rx);
		break;
634
	case ALG_TKIP:
635 636
		result = ieee80211_crypto_tkip_decrypt(rx);
		break;
637
	case ALG_CCMP:
638 639
		result = ieee80211_crypto_ccmp_decrypt(rx);
		break;
640 641
	}

642
	/* either the frame has been decrypted or will be dropped */
643
	rx->status->flag |= RX_FLAG_DECRYPTED;
644 645

	return result;
646 647
}

648 649 650
static void ap_sta_ps_start(struct net_device *dev, struct sta_info *sta)
{
	struct ieee80211_sub_if_data *sdata;
651 652
	DECLARE_MAC_BUF(mac);

653
	sdata = sta->sdata;
654

655
	atomic_inc(&sdata->bss->num_sta_ps);
656
	set_and_clear_sta_flags(sta, WLAN_STA_PS, WLAN_STA_PSPOLL);
657
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
658 659
	printk(KERN_DEBUG "%s: STA %s aid %d enters power save mode\n",
	       dev->name, print_mac(mac, sta->addr), sta->aid);
660 661 662 663 664 665 666 667 668
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
}

static int ap_sta_ps_end(struct net_device *dev, struct sta_info *sta)
{
	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
	struct sk_buff *skb;
	int sent = 0;
	struct ieee80211_sub_if_data *sdata;
669
	struct ieee80211_tx_info *info;
670
	DECLARE_MAC_BUF(mac);
671

672
	sdata = sta->sdata;
673

674
	atomic_dec(&sdata->bss->num_sta_ps);
675

676
	clear_sta_flags(sta, WLAN_STA_PS | WLAN_STA_PSPOLL);
677 678 679 680

	if (!skb_queue_empty(&sta->ps_tx_buf))
		sta_info_clear_tim_bit(sta);

681
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
682 683
	printk(KERN_DEBUG "%s: STA %s aid %d exits power save mode\n",
	       dev->name, print_mac(mac, sta->addr), sta->aid);
684
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
685

686 687
	/* Send all buffered frames to the station */
	while ((skb = skb_dequeue(&sta->tx_filtered)) != NULL) {
688
		info = IEEE80211_SKB_CB(skb);
689
		sent++;
690
		info->flags |= IEEE80211_TX_CTL_REQUEUE;
691 692 693
		dev_queue_xmit(skb);
	}
	while ((skb = skb_dequeue(&sta->ps_tx_buf)) != NULL) {
694
		info = IEEE80211_SKB_CB(skb);
695 696 697
		local->total_ps_buffered--;
		sent++;
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
698
		printk(KERN_DEBUG "%s: STA %s aid %d send PS frame "
699
		       "since STA not sleeping anymore\n", dev->name,
700
		       print_mac(mac, sta->addr), sta->aid);
701
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
702
		info->flags |= IEEE80211_TX_CTL_REQUEUE;
703 704 705 706 707 708
		dev_queue_xmit(skb);
	}

	return sent;
}

709
static ieee80211_rx_result debug_noinline
710
ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
711 712 713
{
	struct sta_info *sta = rx->sta;
	struct net_device *dev = rx->dev;
714
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)rx->skb->data;
715 716

	if (!sta)
717
		return RX_CONTINUE;
718 719 720 721

	/* Update last_rx only for IBSS packets which are for the current
	 * BSSID to avoid keeping the current IBSS network alive in cases where
	 * other STAs are using different BSSID. */
722
	if (rx->sdata->vif.type == IEEE80211_IF_TYPE_IBSS) {
723 724
		u8 *bssid = ieee80211_get_bssid(hdr, rx->skb->len,
						IEEE80211_IF_TYPE_IBSS);
725 726 727 728
		if (compare_ether_addr(bssid, rx->sdata->u.sta.bssid) == 0)
			sta->last_rx = jiffies;
	} else
	if (!is_multicast_ether_addr(hdr->addr1) ||
729
	    rx->sdata->vif.type == IEEE80211_IF_TYPE_STA) {
730 731 732
		/* Update last_rx only for unicast frames in order to prevent
		 * the Probe Request frames (the only broadcast frames from a
		 * STA in infrastructure mode) from keeping a connection alive.
733 734
		 * Mesh beacons will update last_rx when if they are found to
		 * match the current local configuration when processed.
735 736 737 738
		 */
		sta->last_rx = jiffies;
	}

739
	if (!(rx->flags & IEEE80211_RX_RA_MATCH))
740
		return RX_CONTINUE;
741 742 743

	sta->rx_fragments++;
	sta->rx_bytes += rx->skb->len;
744
	sta->last_signal = rx->status->signal;
745
	sta->last_qual = rx->status->qual;
746
	sta->last_noise = rx->status->noise;
747

748 749 750
	if (!ieee80211_has_morefrags(hdr->frame_control) &&
	    (rx->sdata->vif.type == IEEE80211_IF_TYPE_AP ||
	     rx->sdata->vif.type == IEEE80211_IF_TYPE_VLAN)) {
751 752
		/* Change STA power saving mode only in the end of a frame
		 * exchange sequence */
753
		if (test_sta_flags(sta, WLAN_STA_PS) &&
754
		    !ieee80211_has_pm(hdr->frame_control))
755
			rx->sent_ps_buffered += ap_sta_ps_end(dev, sta);
756
		else if (!test_sta_flags(sta, WLAN_STA_PS) &&
757
			 ieee80211_has_pm(hdr->frame_control))
758 759 760 761 762
			ap_sta_ps_start(dev, sta);
	}

	/* Drop data::nullfunc frames silently, since they are used only to
	 * control station power saving mode. */
763
	if (ieee80211_is_nullfunc(hdr->frame_control)) {
764 765 766 767 768
		I802_DEBUG_INC(rx->local->rx_handlers_drop_nullfunc);
		/* Update counter and free packet here to avoid counting this
		 * as a dropped packed. */
		sta->rx_packets++;
		dev_kfree_skb(rx->skb);
769
		return RX_QUEUED;
770 771
	}

772
	return RX_CONTINUE;
773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788
} /* ieee80211_rx_h_sta_process */

static inline struct ieee80211_fragment_entry *
ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
			 unsigned int frag, unsigned int seq, int rx_queue,
			 struct sk_buff **skb)
{
	struct ieee80211_fragment_entry *entry;
	int idx;

	idx = sdata->fragment_next;
	entry = &sdata->fragments[sdata->fragment_next++];
	if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
		sdata->fragment_next = 0;

	if (!skb_queue_empty(&entry->skb_list)) {
789
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
790 791
		struct ieee80211_hdr *hdr =
			(struct ieee80211_hdr *) entry->skb_list.next->data;
792 793
		DECLARE_MAC_BUF(mac);
		DECLARE_MAC_BUF(mac2);
794 795
		printk(KERN_DEBUG "%s: RX reassembly removed oldest "
		       "fragment entry (idx=%d age=%lu seq=%d last_frag=%d "
796
		       "addr1=%s addr2=%s\n",
797 798
		       sdata->dev->name, idx,
		       jiffies - entry->first_frag_time, entry->seq,
799 800
		       entry->last_frag, print_mac(mac, hdr->addr1),
		       print_mac(mac2, hdr->addr2));
801
#endif
802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847
		__skb_queue_purge(&entry->skb_list);
	}

	__skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
	*skb = NULL;
	entry->first_frag_time = jiffies;
	entry->seq = seq;
	entry->rx_queue = rx_queue;
	entry->last_frag = frag;
	entry->ccmp = 0;
	entry->extra_len = 0;

	return entry;
}

static inline struct ieee80211_fragment_entry *
ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
			  u16 fc, unsigned int frag, unsigned int seq,
			  int rx_queue, struct ieee80211_hdr *hdr)
{
	struct ieee80211_fragment_entry *entry;
	int i, idx;

	idx = sdata->fragment_next;
	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
		struct ieee80211_hdr *f_hdr;
		u16 f_fc;

		idx--;
		if (idx < 0)
			idx = IEEE80211_FRAGMENT_MAX - 1;

		entry = &sdata->fragments[idx];
		if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
		    entry->rx_queue != rx_queue ||
		    entry->last_frag + 1 != frag)
			continue;

		f_hdr = (struct ieee80211_hdr *) entry->skb_list.next->data;
		f_fc = le16_to_cpu(f_hdr->frame_control);

		if ((fc & IEEE80211_FCTL_FTYPE) != (f_fc & IEEE80211_FCTL_FTYPE) ||
		    compare_ether_addr(hdr->addr1, f_hdr->addr1) != 0 ||
		    compare_ether_addr(hdr->addr2, f_hdr->addr2) != 0)
			continue;

848
		if (time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
849 850 851 852 853 854 855 856 857
			__skb_queue_purge(&entry->skb_list);
			continue;
		}
		return entry;
	}

	return NULL;
}

858
static ieee80211_rx_result debug_noinline
859
ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
860 861 862 863 864 865
{
	struct ieee80211_hdr *hdr;
	u16 sc;
	unsigned int frag, seq;
	struct ieee80211_fragment_entry *entry;
	struct sk_buff *skb;
866
	DECLARE_MAC_BUF(mac);
867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884

	hdr = (struct ieee80211_hdr *) rx->skb->data;
	sc = le16_to_cpu(hdr->seq_ctrl);
	frag = sc & IEEE80211_SCTL_FRAG;

	if (likely((!(rx->fc & IEEE80211_FCTL_MOREFRAGS) && frag == 0) ||
		   (rx->skb)->len < 24 ||
		   is_multicast_ether_addr(hdr->addr1))) {
		/* not fragmented */
		goto out;
	}
	I802_DEBUG_INC(rx->local->rx_handlers_fragments);

	seq = (sc & IEEE80211_SCTL_SEQ) >> 4;

	if (frag == 0) {
		/* This is the first fragment of a new frame. */
		entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
885
						 rx->queue, &(rx->skb));
886
		if (rx->key && rx->key->conf.alg == ALG_CCMP &&
887 888 889 890 891
		    (rx->fc & IEEE80211_FCTL_PROTECTED)) {
			/* Store CCMP PN so that we can verify that the next
			 * fragment has a sequential PN value. */
			entry->ccmp = 1;
			memcpy(entry->last_pn,
892
			       rx->key->u.ccmp.rx_pn[rx->queue],
893 894
			       CCMP_PN_LEN);
		}
895
		return RX_QUEUED;
896 897 898 899 900 901
	}

	/* This is a fragment for a frame that should already be pending in
	 * fragment cache. Add this fragment to the end of the pending entry.
	 */
	entry = ieee80211_reassemble_find(rx->sdata, rx->fc, frag, seq,
902
					  rx->queue, hdr);
903 904
	if (!entry) {
		I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
Johannes Berg's avatar
Johannes Berg committed
905
		return RX_DROP_MONITOR;
906 907 908 909 910 911 912
	}

	/* Verify that MPDUs within one MSDU have sequential PN values.
	 * (IEEE 802.11i, 8.3.3.4.5) */
	if (entry->ccmp) {
		int i;
		u8 pn[CCMP_PN_LEN], *rpn;
913
		if (!rx->key || rx->key->conf.alg != ALG_CCMP)
Johannes Berg's avatar
Johannes Berg committed
914
			return RX_DROP_UNUSABLE;
915 916 917 918 919 920
		memcpy(pn, entry->last_pn, CCMP_PN_LEN);
		for (i = CCMP_PN_LEN - 1; i >= 0; i--) {
			pn[i]++;
			if (pn[i])
				break;
		}
921
		rpn = rx->key->u.ccmp.rx_pn[rx->queue];
922
		if (memcmp(pn, rpn, CCMP_PN_LEN))
Johannes Berg's avatar
Johannes Berg committed
923
			return RX_DROP_UNUSABLE;
924 925 926 927 928 929 930 931 932
		memcpy(entry->last_pn, pn, CCMP_PN_LEN);
	}

	skb_pull(rx->skb, ieee80211_get_hdrlen(rx->fc));
	__skb_queue_tail(&entry->skb_list, rx->skb);
	entry->last_frag = frag;
	entry->extra_len += rx->skb->len;
	if (rx->fc & IEEE80211_FCTL_MOREFRAGS) {
		rx->skb = NULL;
933
		return RX_QUEUED;
934 935 936 937 938 939 940 941 942
	}

	rx->skb = __skb_dequeue(&entry->skb_list);
	if (skb_tailroom(rx->skb) < entry->extra_len) {
		I802_DEBUG_INC(rx->local->rx_expand_skb_head2);
		if (unlikely(pskb_expand_head(rx->skb, 0, entry->extra_len,
					      GFP_ATOMIC))) {
			I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
			__skb_queue_purge(&entry->skb_list);
Johannes Berg's avatar
Johannes Berg committed
943
			return RX_DROP_UNUSABLE;
944 945 946 947 948 949 950 951
		}
	}
	while ((skb = __skb_dequeue(&entry->skb_list))) {
		memcpy(skb_put(rx->skb, skb->len), skb->data, skb->len);
		dev_kfree_skb(skb);
	}

	/* Complete frame has been reassembled - process it now */
952
	rx->flags |= IEEE80211_RX_FRAGMENTED;
953 954 955 956 957 958 959 960

 out:
	if (rx->sta)
		rx->sta->rx_packets++;
	if (is_multicast_ether_addr(hdr->addr1))
		rx->local->dot11MulticastReceivedFrameCount++;
	else
		ieee80211_led_rx(rx->local);
961
	return RX_CONTINUE;
962 963
}

964
static ieee80211_rx_result debug_noinline
965
ieee80211_rx_h_ps_poll(struct ieee80211_rx_data *rx)
966
{
967
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(rx->dev);
968 969
	struct sk_buff *skb;
	int no_pending_pkts;
970
	DECLARE_MAC_BUF(mac);
971 972 973 974

	if (likely(!rx->sta ||
		   (rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_CTL ||
		   (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_PSPOLL ||
975
		   !(rx->flags & IEEE80211_RX_RA_MATCH)))
976
		return RX_CONTINUE;
977

978 979
	if ((sdata->vif.type != IEEE80211_IF_TYPE_AP) &&
	    (sdata->vif.type != IEEE80211_IF_TYPE_VLAN))
Johannes Berg's avatar
Johannes Berg committed
980
		return RX_DROP_UNUSABLE;
981

982 983 984 985 986 987 988 989 990 991 992 993 994
	skb = skb_dequeue(&rx->sta->tx_filtered);
	if (!skb) {
		skb = skb_dequeue(&rx->sta->ps_tx_buf);
		if (skb)
			rx->local->total_ps_buffered--;
	}
	no_pending_pkts = skb_queue_empty(&rx->sta->tx_filtered) &&
		skb_queue_empty(&rx->sta->ps_tx_buf);

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

995 996 997 998
		/*
		 * Tell TX path to send one frame even though the STA may
		 * still remain is PS mode after this frame exchange.
		 */
999
		set_sta_flags(rx->sta, WLAN_STA_PSPOLL);
1000 1001

#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1002 1003
		printk(KERN_DEBUG "STA %s aid %d: PS Poll (entries after %d)\n",
		       print_mac(mac, rx->sta->addr), rx->sta->aid,
1004 1005 1006 1007 1008
		       skb_queue_len(&rx->sta->ps_tx_buf));
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */

		/* Use MoreData flag to indicate whether there are more
		 * buffered frames for this STA */
1009
		if (no_pending_pkts)
1010
			hdr->frame_control &= cpu_to_le16(~IEEE80211_FCTL_MOREDATA);
1011
		else
1012 1013 1014 1015
			hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_MOREDATA);

		dev_queue_xmit(skb);

1016 1017
		if (no_pending_pkts)
			sta_info_clear_tim_bit(rx->sta);
1018
#ifdef CONFIG_MAC80211_VERBOSE_PS_DEBUG
1019
	} else if (!rx->sent_ps_buffered) {
1020 1021 1022 1023 1024 1025
		/*
		 * FIXME: This can be the result of a race condition between
		 *	  us expiring a frame and the station polling for it.
		 *	  Should we send it a null-func frame indicating we
		 *	  have nothing buffered for it?
		 */
1026
		printk(KERN_DEBUG "%s: STA %s sent PS Poll even "
1027
		       "though there are no buffered frames for it\n",
1028
		       rx->dev->name, print_mac(mac, rx->sta->addr));
1029 1030 1031
#endif /* CONFIG_MAC80211_VERBOSE_PS_DEBUG */
	}

1032
	/* Free PS Poll skb here instead of returning RX_DROP that would
1033 1034 1035
	 * count as an dropped frame. */
	dev_kfree_skb(rx->skb);

1036
	return RX_QUEUED;
1037 1038
}

1039
static ieee80211_rx_result debug_noinline
1040
ieee80211_rx_h_remove_qos_control(struct ieee80211_rx_data *rx)
1041 1042
{
	u8 *data = rx->skb->data;
1043
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)data;
1044

1045
	if (!ieee80211_is_data_qos(hdr->frame_control))
1046
		return RX_CONTINUE;
1047 1048

	/* remove the qos control field, update frame type and meta-data */
1049 1050 1051
	memmove(data + IEEE80211_QOS_CTL_LEN, data,
		ieee80211_hdrlen(hdr->frame_control) - IEEE80211_QOS_CTL_LEN);
	hdr = (struct ieee80211_hdr *)skb_pull(rx->skb, IEEE80211_QOS_CTL_LEN);
1052
	/* change frame type to non QOS */
1053 1054
	rx->fc &= ~IEEE80211_STYPE_QOS_DATA;
	hdr->frame_control &= ~cpu_to_le16(IEEE80211_STYPE_QOS_DATA);
1055

1056
	return RX_CONTINUE;
1057 1058
}

1059
static int
1060
ieee80211_802_1x_port_control(struct ieee80211_rx_data *rx)
1061
{
1062
	if (unlikely(!rx->sta ||
1063
	    !test_sta_flags(rx->sta, WLAN_STA_AUTHORIZED)))
1064
		return -EACCES;
1065

1066
	return 0;
1067 1068
}

1069
static int
1070
ieee80211_drop_unencrypted(struct ieee80211_rx_data *rx)
1071
{
1072
	/*
1073 1074
	 * Pass through unencrypted frames if the hardware has
	 * decrypted them already.
1075
	 */
1076
	if (rx->status->flag & RX_FLAG_DECRYPTED)
1077
		return 0;
1078 1079 1080 1081 1082

	/* Drop unencrypted frames if key is set. */
	if (unlikely(!(rx->fc & IEEE80211_FCTL_PROTECTED) &&
		     (rx->fc & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_DATA &&
		     (rx->fc & IEEE80211_FCTL_STYPE) != IEEE80211_STYPE_NULLFUNC &&
1083
		     (rx->key || rx->sdata->drop_unencrypted)))
1084
		return -EACCES;
1085

1086
	return 0;
1087 1088
}

1089
static int
1090
ieee80211_data_to_8023(struct ieee80211_rx_data *rx)
1091 1092 1093 1094 1095 1096
{
	struct net_device *dev = rx->dev;
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data;
	u16 fc, hdrlen, ethertype;
	u8 *payload;
	u8 dst[ETH_ALEN];
1097
	u8 src[ETH_ALEN] __aligned(2);
1098
	struct sk_buff *skb = rx->skb;
1099
	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);