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   1#include <linux/etherdevice.h>
   2#include <linux/slab.h>
   3#include <linux/export.h>
   4#include <net/lib80211.h>
   5#include <linux/if_arp.h>
   6
   7#include "hostap_80211.h"
   8#include "hostap.h"
   9#include "hostap_ap.h"
  10
  11/* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */
  12/* Ethernet-II snap header (RFC1042 for most EtherTypes) */
  13static unsigned char rfc1042_header[] =
  14{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };
  15/* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */
  16static unsigned char bridge_tunnel_header[] =
  17{ 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 };
  18/* No encapsulation header if EtherType < 0x600 (=length) */
  19
  20void hostap_dump_rx_80211(const char *name, struct sk_buff *skb,
  21			  struct hostap_80211_rx_status *rx_stats)
  22{
  23	struct ieee80211_hdr *hdr;
  24	u16 fc;
  25
  26	hdr = (struct ieee80211_hdr *) skb->data;
  27
  28	printk(KERN_DEBUG "%s: RX signal=%d noise=%d rate=%d len=%d "
  29	       "jiffies=%ld\n",
  30	       name, rx_stats->signal, rx_stats->noise, rx_stats->rate,
  31	       skb->len, jiffies);
  32
  33	if (skb->len < 2)
  34		return;
  35
  36	fc = le16_to_cpu(hdr->frame_control);
  37	printk(KERN_DEBUG "   FC=0x%04x (type=%d:%d)%s%s",
  38	       fc, (fc & IEEE80211_FCTL_FTYPE) >> 2,
  39	       (fc & IEEE80211_FCTL_STYPE) >> 4,
  40	       fc & IEEE80211_FCTL_TODS ? " [ToDS]" : "",
  41	       fc & IEEE80211_FCTL_FROMDS ? " [FromDS]" : "");
  42
  43	if (skb->len < IEEE80211_DATA_HDR3_LEN) {
  44		printk("\n");
  45		return;
  46	}
  47
  48	printk(" dur=0x%04x seq=0x%04x\n", le16_to_cpu(hdr->duration_id),
  49	       le16_to_cpu(hdr->seq_ctrl));
  50
  51	printk(KERN_DEBUG "   A1=%pM", hdr->addr1);
  52	printk(" A2=%pM", hdr->addr2);
  53	printk(" A3=%pM", hdr->addr3);
  54	if (skb->len >= 30)
  55		printk(" A4=%pM", hdr->addr4);
  56	printk("\n");
  57}
  58
  59
  60/* Send RX frame to netif with 802.11 (and possible prism) header.
  61 * Called from hardware or software IRQ context. */
  62int prism2_rx_80211(struct net_device *dev, struct sk_buff *skb,
  63		    struct hostap_80211_rx_status *rx_stats, int type)
  64{
  65	struct hostap_interface *iface;
  66	local_info_t *local;
  67	int hdrlen, phdrlen, head_need, tail_need;
  68	u16 fc;
  69	int prism_header, ret;
  70	struct ieee80211_hdr *fhdr;
  71
  72	iface = netdev_priv(dev);
  73	local = iface->local;
  74
  75	if (dev->type == ARPHRD_IEEE80211_PRISM) {
  76		if (local->monitor_type == PRISM2_MONITOR_PRISM) {
  77			prism_header = 1;
  78			phdrlen = sizeof(struct linux_wlan_ng_prism_hdr);
  79		} else { /* local->monitor_type == PRISM2_MONITOR_CAPHDR */
  80			prism_header = 2;
  81			phdrlen = sizeof(struct linux_wlan_ng_cap_hdr);
  82		}
  83	} else if (dev->type == ARPHRD_IEEE80211_RADIOTAP) {
  84		prism_header = 3;
  85		phdrlen = sizeof(struct hostap_radiotap_rx);
  86	} else {
  87		prism_header = 0;
  88		phdrlen = 0;
  89	}
  90
  91	fhdr = (struct ieee80211_hdr *) skb->data;
  92	fc = le16_to_cpu(fhdr->frame_control);
  93
  94	if (type == PRISM2_RX_MGMT && (fc & IEEE80211_FCTL_VERS)) {
  95		printk(KERN_DEBUG "%s: dropped management frame with header "
  96		       "version %d\n", dev->name, fc & IEEE80211_FCTL_VERS);
  97		dev_kfree_skb_any(skb);
  98		return 0;
  99	}
 100
 101	hdrlen = hostap_80211_get_hdrlen(fhdr->frame_control);
 102
 103	/* check if there is enough room for extra data; if not, expand skb
 104	 * buffer to be large enough for the changes */
 105	head_need = phdrlen;
 106	tail_need = 0;
 107#ifdef PRISM2_ADD_BOGUS_CRC
 108	tail_need += 4;
 109#endif /* PRISM2_ADD_BOGUS_CRC */
 110
 111	head_need -= skb_headroom(skb);
 112	tail_need -= skb_tailroom(skb);
 113
 114	if (head_need > 0 || tail_need > 0) {
 115		if (pskb_expand_head(skb, head_need > 0 ? head_need : 0,
 116				     tail_need > 0 ? tail_need : 0,
 117				     GFP_ATOMIC)) {
 118			printk(KERN_DEBUG "%s: prism2_rx_80211 failed to "
 119			       "reallocate skb buffer\n", dev->name);
 120			dev_kfree_skb_any(skb);
 121			return 0;
 122		}
 123	}
 124
 125	/* We now have an skb with enough head and tail room, so just insert
 126	 * the extra data */
 127
 128#ifdef PRISM2_ADD_BOGUS_CRC
 129	memset(skb_put(skb, 4), 0xff, 4); /* Prism2 strips CRC */
 130#endif /* PRISM2_ADD_BOGUS_CRC */
 131
 132	if (prism_header == 1) {
 133		struct linux_wlan_ng_prism_hdr *hdr;
 134		hdr = (struct linux_wlan_ng_prism_hdr *)
 135			skb_push(skb, phdrlen);
 136		memset(hdr, 0, phdrlen);
 137		hdr->msgcode = LWNG_CAP_DID_BASE;
 138		hdr->msglen = sizeof(*hdr);
 139		memcpy(hdr->devname, dev->name, sizeof(hdr->devname));
 140#define LWNG_SETVAL(f,i,s,l,d) \
 141hdr->f.did = LWNG_CAP_DID_BASE | (i << 12); \
 142hdr->f.status = s; hdr->f.len = l; hdr->f.data = d
 143		LWNG_SETVAL(hosttime, 1, 0, 4, jiffies);
 144		LWNG_SETVAL(mactime, 2, 0, 4, rx_stats->mac_time);
 145		LWNG_SETVAL(channel, 3, 1 /* no value */, 4, 0);
 146		LWNG_SETVAL(rssi, 4, 1 /* no value */, 4, 0);
 147		LWNG_SETVAL(sq, 5, 1 /* no value */, 4, 0);
 148		LWNG_SETVAL(signal, 6, 0, 4, rx_stats->signal);
 149		LWNG_SETVAL(noise, 7, 0, 4, rx_stats->noise);
 150		LWNG_SETVAL(rate, 8, 0, 4, rx_stats->rate / 5);
 151		LWNG_SETVAL(istx, 9, 0, 4, 0);
 152		LWNG_SETVAL(frmlen, 10, 0, 4, skb->len - phdrlen);
 153#undef LWNG_SETVAL
 154	} else if (prism_header == 2) {
 155		struct linux_wlan_ng_cap_hdr *hdr;
 156		hdr = (struct linux_wlan_ng_cap_hdr *)
 157			skb_push(skb, phdrlen);
 158		memset(hdr, 0, phdrlen);
 159		hdr->version    = htonl(LWNG_CAPHDR_VERSION);
 160		hdr->length     = htonl(phdrlen);
 161		hdr->mactime    = __cpu_to_be64(rx_stats->mac_time);
 162		hdr->hosttime   = __cpu_to_be64(jiffies);
 163		hdr->phytype    = htonl(4); /* dss_dot11_b */
 164		hdr->channel    = htonl(local->channel);
 165		hdr->datarate   = htonl(rx_stats->rate);
 166		hdr->antenna    = htonl(0); /* unknown */
 167		hdr->priority   = htonl(0); /* unknown */
 168		hdr->ssi_type   = htonl(3); /* raw */
 169		hdr->ssi_signal = htonl(rx_stats->signal);
 170		hdr->ssi_noise  = htonl(rx_stats->noise);
 171		hdr->preamble   = htonl(0); /* unknown */
 172		hdr->encoding   = htonl(1); /* cck */
 173	} else if (prism_header == 3) {
 174		struct hostap_radiotap_rx *hdr;
 175		hdr = (struct hostap_radiotap_rx *)skb_push(skb, phdrlen);
 176		memset(hdr, 0, phdrlen);
 177		hdr->hdr.it_len = cpu_to_le16(phdrlen);
 178		hdr->hdr.it_present =
 179			cpu_to_le32((1 << IEEE80211_RADIOTAP_TSFT) |
 180				    (1 << IEEE80211_RADIOTAP_CHANNEL) |
 181				    (1 << IEEE80211_RADIOTAP_RATE) |
 182				    (1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL) |
 183				    (1 << IEEE80211_RADIOTAP_DBM_ANTNOISE));
 184		hdr->tsft = cpu_to_le64(rx_stats->mac_time);
 185		hdr->chan_freq = cpu_to_le16(freq_list[local->channel - 1]);
 186		hdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_CCK |
 187						 IEEE80211_CHAN_2GHZ);
 188		hdr->rate = rx_stats->rate / 5;
 189		hdr->dbm_antsignal = rx_stats->signal;
 190		hdr->dbm_antnoise = rx_stats->noise;
 191	}
 192
 193	ret = skb->len - phdrlen;
 194	skb->dev = dev;
 195	skb_reset_mac_header(skb);
 196	skb_pull(skb, hdrlen);
 197	if (prism_header)
 198		skb_pull(skb, phdrlen);
 199	skb->pkt_type = PACKET_OTHERHOST;
 200	skb->protocol = cpu_to_be16(ETH_P_802_2);
 201	memset(skb->cb, 0, sizeof(skb->cb));
 202	netif_rx(skb);
 203
 204	return ret;
 205}
 206
 207
 208/* Called only as a tasklet (software IRQ) */
 209static void monitor_rx(struct net_device *dev, struct sk_buff *skb,
 210		       struct hostap_80211_rx_status *rx_stats)
 211{
 212	int len;
 213
 214	len = prism2_rx_80211(dev, skb, rx_stats, PRISM2_RX_MONITOR);
 215	dev->stats.rx_packets++;
 216	dev->stats.rx_bytes += len;
 217}
 218
 219
 220/* Called only as a tasklet (software IRQ) */
 221static struct prism2_frag_entry *
 222prism2_frag_cache_find(local_info_t *local, unsigned int seq,
 223		       unsigned int frag, u8 *src, u8 *dst)
 224{
 225	struct prism2_frag_entry *entry;
 226	int i;
 227
 228	for (i = 0; i < PRISM2_FRAG_CACHE_LEN; i++) {
 229		entry = &local->frag_cache[i];
 230		if (entry->skb != NULL &&
 231		    time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
 232			printk(KERN_DEBUG "%s: expiring fragment cache entry "
 233			       "seq=%u last_frag=%u\n",
 234			       local->dev->name, entry->seq, entry->last_frag);
 235			dev_kfree_skb(entry->skb);
 236			entry->skb = NULL;
 237		}
 238
 239		if (entry->skb != NULL && entry->seq == seq &&
 240		    (entry->last_frag + 1 == frag || frag == -1) &&
 241		    memcmp(entry->src_addr, src, ETH_ALEN) == 0 &&
 242		    memcmp(entry->dst_addr, dst, ETH_ALEN) == 0)
 243			return entry;
 244	}
 245
 246	return NULL;
 247}
 248
 249
 250/* Called only as a tasklet (software IRQ) */
 251static struct sk_buff *
 252prism2_frag_cache_get(local_info_t *local, struct ieee80211_hdr *hdr)
 253{
 254	struct sk_buff *skb = NULL;
 255	u16 sc;
 256	unsigned int frag, seq;
 257	struct prism2_frag_entry *entry;
 258
 259	sc = le16_to_cpu(hdr->seq_ctrl);
 260	frag = sc & IEEE80211_SCTL_FRAG;
 261	seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
 262
 263	if (frag == 0) {
 264		/* Reserve enough space to fit maximum frame length */
 265		skb = dev_alloc_skb(local->dev->mtu +
 266				    sizeof(struct ieee80211_hdr) +
 267				    8 /* LLC */ +
 268				    2 /* alignment */ +
 269				    8 /* WEP */ + ETH_ALEN /* WDS */);
 270		if (skb == NULL)
 271			return NULL;
 272
 273		entry = &local->frag_cache[local->frag_next_idx];
 274		local->frag_next_idx++;
 275		if (local->frag_next_idx >= PRISM2_FRAG_CACHE_LEN)
 276			local->frag_next_idx = 0;
 277
 278		if (entry->skb != NULL)
 279			dev_kfree_skb(entry->skb);
 280
 281		entry->first_frag_time = jiffies;
 282		entry->seq = seq;
 283		entry->last_frag = frag;
 284		entry->skb = skb;
 285		memcpy(entry->src_addr, hdr->addr2, ETH_ALEN);
 286		memcpy(entry->dst_addr, hdr->addr1, ETH_ALEN);
 287	} else {
 288		/* received a fragment of a frame for which the head fragment
 289		 * should have already been received */
 290		entry = prism2_frag_cache_find(local, seq, frag, hdr->addr2,
 291					       hdr->addr1);
 292		if (entry != NULL) {
 293			entry->last_frag = frag;
 294			skb = entry->skb;
 295		}
 296	}
 297
 298	return skb;
 299}
 300
 301
 302/* Called only as a tasklet (software IRQ) */
 303static int prism2_frag_cache_invalidate(local_info_t *local,
 304					struct ieee80211_hdr *hdr)
 305{
 306	u16 sc;
 307	unsigned int seq;
 308	struct prism2_frag_entry *entry;
 309
 310	sc = le16_to_cpu(hdr->seq_ctrl);
 311	seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
 312
 313	entry = prism2_frag_cache_find(local, seq, -1, hdr->addr2, hdr->addr1);
 314
 315	if (entry == NULL) {
 316		printk(KERN_DEBUG "%s: could not invalidate fragment cache "
 317		       "entry (seq=%u)\n",
 318		       local->dev->name, seq);
 319		return -1;
 320	}
 321
 322	entry->skb = NULL;
 323	return 0;
 324}
 325
 326
 327static struct hostap_bss_info *__hostap_get_bss(local_info_t *local, u8 *bssid,
 328						u8 *ssid, size_t ssid_len)
 329{
 330	struct list_head *ptr;
 331	struct hostap_bss_info *bss;
 332
 333	list_for_each(ptr, &local->bss_list) {
 334		bss = list_entry(ptr, struct hostap_bss_info, list);
 335		if (memcmp(bss->bssid, bssid, ETH_ALEN) == 0 &&
 336		    (ssid == NULL ||
 337		     (ssid_len == bss->ssid_len &&
 338		      memcmp(ssid, bss->ssid, ssid_len) == 0))) {
 339			list_move(&bss->list, &local->bss_list);
 340			return bss;
 341		}
 342	}
 343
 344	return NULL;
 345}
 346
 347
 348static struct hostap_bss_info *__hostap_add_bss(local_info_t *local, u8 *bssid,
 349						u8 *ssid, size_t ssid_len)
 350{
 351	struct hostap_bss_info *bss;
 352
 353	if (local->num_bss_info >= HOSTAP_MAX_BSS_COUNT) {
 354		bss = list_entry(local->bss_list.prev,
 355				 struct hostap_bss_info, list);
 356		list_del(&bss->list);
 357		local->num_bss_info--;
 358	} else {
 359		bss = kmalloc(sizeof(*bss), GFP_ATOMIC);
 360		if (bss == NULL)
 361			return NULL;
 362	}
 363
 364	memset(bss, 0, sizeof(*bss));
 365	memcpy(bss->bssid, bssid, ETH_ALEN);
 366	memcpy(bss->ssid, ssid, ssid_len);
 367	bss->ssid_len = ssid_len;
 368	local->num_bss_info++;
 369	list_add(&bss->list, &local->bss_list);
 370	return bss;
 371}
 372
 373
 374static void __hostap_expire_bss(local_info_t *local)
 375{
 376	struct hostap_bss_info *bss;
 377
 378	while (local->num_bss_info > 0) {
 379		bss = list_entry(local->bss_list.prev,
 380				 struct hostap_bss_info, list);
 381		if (!time_after(jiffies, bss->last_update + 60 * HZ))
 382			break;
 383
 384		list_del(&bss->list);
 385		local->num_bss_info--;
 386		kfree(bss);
 387	}
 388}
 389
 390
 391/* Both IEEE 802.11 Beacon and Probe Response frames have similar structure, so
 392 * the same routine can be used to parse both of them. */
 393static void hostap_rx_sta_beacon(local_info_t *local, struct sk_buff *skb,
 394				 int stype)
 395{
 396	struct hostap_ieee80211_mgmt *mgmt;
 397	int left, chan = 0;
 398	u8 *pos;
 399	u8 *ssid = NULL, *wpa = NULL, *rsn = NULL;
 400	size_t ssid_len = 0, wpa_len = 0, rsn_len = 0;
 401	struct hostap_bss_info *bss;
 402
 403	if (skb->len < IEEE80211_MGMT_HDR_LEN + sizeof(mgmt->u.beacon))
 404		return;
 405
 406	mgmt = (struct hostap_ieee80211_mgmt *) skb->data;
 407	pos = mgmt->u.beacon.variable;
 408	left = skb->len - (pos - skb->data);
 409
 410	while (left >= 2) {
 411		if (2 + pos[1] > left)
 412			return; /* parse failed */
 413		switch (*pos) {
 414		case WLAN_EID_SSID:
 415			ssid = pos + 2;
 416			ssid_len = pos[1];
 417			break;
 418		case WLAN_EID_GENERIC:
 419			if (pos[1] >= 4 &&
 420			    pos[2] == 0x00 && pos[3] == 0x50 &&
 421			    pos[4] == 0xf2 && pos[5] == 1) {
 422				wpa = pos;
 423				wpa_len = pos[1] + 2;
 424			}
 425			break;
 426		case WLAN_EID_RSN:
 427			rsn = pos;
 428			rsn_len = pos[1] + 2;
 429			break;
 430		case WLAN_EID_DS_PARAMS:
 431			if (pos[1] >= 1)
 432				chan = pos[2];
 433			break;
 434		}
 435		left -= 2 + pos[1];
 436		pos += 2 + pos[1];
 437	}
 438
 439	if (wpa_len > MAX_WPA_IE_LEN)
 440		wpa_len = MAX_WPA_IE_LEN;
 441	if (rsn_len > MAX_WPA_IE_LEN)
 442		rsn_len = MAX_WPA_IE_LEN;
 443	if (ssid_len > sizeof(bss->ssid))
 444		ssid_len = sizeof(bss->ssid);
 445
 446	spin_lock(&local->lock);
 447	bss = __hostap_get_bss(local, mgmt->bssid, ssid, ssid_len);
 448	if (bss == NULL)
 449		bss = __hostap_add_bss(local, mgmt->bssid, ssid, ssid_len);
 450	if (bss) {
 451		bss->last_update = jiffies;
 452		bss->count++;
 453		bss->capab_info = le16_to_cpu(mgmt->u.beacon.capab_info);
 454		if (wpa) {
 455			memcpy(bss->wpa_ie, wpa, wpa_len);
 456			bss->wpa_ie_len = wpa_len;
 457		} else
 458			bss->wpa_ie_len = 0;
 459		if (rsn) {
 460			memcpy(bss->rsn_ie, rsn, rsn_len);
 461			bss->rsn_ie_len = rsn_len;
 462		} else
 463			bss->rsn_ie_len = 0;
 464		bss->chan = chan;
 465	}
 466	__hostap_expire_bss(local);
 467	spin_unlock(&local->lock);
 468}
 469
 470
 471static int
 472hostap_rx_frame_mgmt(local_info_t *local, struct sk_buff *skb,
 473		     struct hostap_80211_rx_status *rx_stats, u16 type,
 474		     u16 stype)
 475{
 476	if (local->iw_mode == IW_MODE_MASTER)
 477		hostap_update_sta_ps(local, (struct ieee80211_hdr *) skb->data);
 478
 479	if (local->hostapd && type == IEEE80211_FTYPE_MGMT) {
 480		if (stype == IEEE80211_STYPE_BEACON &&
 481		    local->iw_mode == IW_MODE_MASTER) {
 482			struct sk_buff *skb2;
 483			/* Process beacon frames also in kernel driver to
 484			 * update STA(AP) table statistics */
 485			skb2 = skb_clone(skb, GFP_ATOMIC);
 486			if (skb2)
 487				hostap_rx(skb2->dev, skb2, rx_stats);
 488		}
 489
 490		/* send management frames to the user space daemon for
 491		 * processing */
 492		local->apdevstats.rx_packets++;
 493		local->apdevstats.rx_bytes += skb->len;
 494		if (local->apdev == NULL)
 495			return -1;
 496		prism2_rx_80211(local->apdev, skb, rx_stats, PRISM2_RX_MGMT);
 497		return 0;
 498	}
 499
 500	if (local->iw_mode == IW_MODE_MASTER) {
 501		if (type != IEEE80211_FTYPE_MGMT &&
 502		    type != IEEE80211_FTYPE_CTL) {
 503			printk(KERN_DEBUG "%s: unknown management frame "
 504			       "(type=0x%02x, stype=0x%02x) dropped\n",
 505			       skb->dev->name, type >> 2, stype >> 4);
 506			return -1;
 507		}
 508
 509		hostap_rx(skb->dev, skb, rx_stats);
 510		return 0;
 511	} else if (type == IEEE80211_FTYPE_MGMT &&
 512		   (stype == IEEE80211_STYPE_BEACON ||
 513		    stype == IEEE80211_STYPE_PROBE_RESP)) {
 514		hostap_rx_sta_beacon(local, skb, stype);
 515		return -1;
 516	} else if (type == IEEE80211_FTYPE_MGMT &&
 517		   (stype == IEEE80211_STYPE_ASSOC_RESP ||
 518		    stype == IEEE80211_STYPE_REASSOC_RESP)) {
 519		/* Ignore (Re)AssocResp silently since these are not currently
 520		 * needed but are still received when WPA/RSN mode is enabled.
 521		 */
 522		return -1;
 523	} else {
 524		printk(KERN_DEBUG "%s: hostap_rx_frame_mgmt: dropped unhandled"
 525		       " management frame in non-Host AP mode (type=%d:%d)\n",
 526		       skb->dev->name, type >> 2, stype >> 4);
 527		return -1;
 528	}
 529}
 530
 531
 532/* Called only as a tasklet (software IRQ) */
 533static struct net_device *prism2_rx_get_wds(local_info_t *local,
 534						   u8 *addr)
 535{
 536	struct hostap_interface *iface = NULL;
 537	struct list_head *ptr;
 538
 539	read_lock_bh(&local->iface_lock);
 540	list_for_each(ptr, &local->hostap_interfaces) {
 541		iface = list_entry(ptr, struct hostap_interface, list);
 542		if (iface->type == HOSTAP_INTERFACE_WDS &&
 543		    memcmp(iface->u.wds.remote_addr, addr, ETH_ALEN) == 0)
 544			break;
 545		iface = NULL;
 546	}
 547	read_unlock_bh(&local->iface_lock);
 548
 549	return iface ? iface->dev : NULL;
 550}
 551
 552
 553static int
 554hostap_rx_frame_wds(local_info_t *local, struct ieee80211_hdr *hdr, u16 fc,
 555		    struct net_device **wds)
 556{
 557	/* FIX: is this really supposed to accept WDS frames only in Master
 558	 * mode? What about Repeater or Managed with WDS frames? */
 559	if ((fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) !=
 560	    (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS) &&
 561	    (local->iw_mode != IW_MODE_MASTER || !(fc & IEEE80211_FCTL_TODS)))
 562		return 0; /* not a WDS frame */
 563
 564	/* Possible WDS frame: either IEEE 802.11 compliant (if FromDS)
 565	 * or own non-standard frame with 4th address after payload */
 566	if (memcmp(hdr->addr1, local->dev->dev_addr, ETH_ALEN) != 0 &&
 567	    (hdr->addr1[0] != 0xff || hdr->addr1[1] != 0xff ||
 568	     hdr->addr1[2] != 0xff || hdr->addr1[3] != 0xff ||
 569	     hdr->addr1[4] != 0xff || hdr->addr1[5] != 0xff)) {
 570		/* RA (or BSSID) is not ours - drop */
 571		PDEBUG(DEBUG_EXTRA2, "%s: received WDS frame with "
 572		       "not own or broadcast %s=%pM\n",
 573		       local->dev->name,
 574		       fc & IEEE80211_FCTL_FROMDS ? "RA" : "BSSID",
 575		       hdr->addr1);
 576		return -1;
 577	}
 578
 579	/* check if the frame came from a registered WDS connection */
 580	*wds = prism2_rx_get_wds(local, hdr->addr2);
 581	if (*wds == NULL && fc & IEEE80211_FCTL_FROMDS &&
 582	    (local->iw_mode != IW_MODE_INFRA ||
 583	     !(local->wds_type & HOSTAP_WDS_AP_CLIENT) ||
 584	     memcmp(hdr->addr2, local->bssid, ETH_ALEN) != 0)) {
 585		/* require that WDS link has been registered with TA or the
 586		 * frame is from current AP when using 'AP client mode' */
 587		PDEBUG(DEBUG_EXTRA, "%s: received WDS[4 addr] frame "
 588		       "from unknown TA=%pM\n",
 589		       local->dev->name, hdr->addr2);
 590		if (local->ap && local->ap->autom_ap_wds)
 591			hostap_wds_link_oper(local, hdr->addr2, WDS_ADD);
 592		return -1;
 593	}
 594
 595	if (*wds && !(fc & IEEE80211_FCTL_FROMDS) && local->ap &&
 596	    hostap_is_sta_assoc(local->ap, hdr->addr2)) {
 597		/* STA is actually associated with us even though it has a
 598		 * registered WDS link. Assume it is in 'AP client' mode.
 599		 * Since this is a 3-addr frame, assume it is not (bogus) WDS
 600		 * frame and process it like any normal ToDS frame from
 601		 * associated STA. */
 602		*wds = NULL;
 603	}
 604
 605	return 0;
 606}
 607
 608
 609static int hostap_is_eapol_frame(local_info_t *local, struct sk_buff *skb)
 610{
 611	struct net_device *dev = local->dev;
 612	u16 fc, ethertype;
 613	struct ieee80211_hdr *hdr;
 614	u8 *pos;
 615
 616	if (skb->len < 24)
 617		return 0;
 618
 619	hdr = (struct ieee80211_hdr *) skb->data;
 620	fc = le16_to_cpu(hdr->frame_control);
 621
 622	/* check that the frame is unicast frame to us */
 623	if ((fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
 624	    IEEE80211_FCTL_TODS &&
 625	    memcmp(hdr->addr1, dev->dev_addr, ETH_ALEN) == 0 &&
 626	    memcmp(hdr->addr3, dev->dev_addr, ETH_ALEN) == 0) {
 627		/* ToDS frame with own addr BSSID and DA */
 628	} else if ((fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
 629		   IEEE80211_FCTL_FROMDS &&
 630		   memcmp(hdr->addr1, dev->dev_addr, ETH_ALEN) == 0) {
 631		/* FromDS frame with own addr as DA */
 632	} else
 633		return 0;
 634
 635	if (skb->len < 24 + 8)
 636		return 0;
 637
 638	/* check for port access entity Ethernet type */
 639	pos = skb->data + 24;
 640	ethertype = (pos[6] << 8) | pos[7];
 641	if (ethertype == ETH_P_PAE)
 642		return 1;
 643
 644	return 0;
 645}
 646
 647
 648/* Called only as a tasklet (software IRQ) */
 649static int
 650hostap_rx_frame_decrypt(local_info_t *local, struct sk_buff *skb,
 651			struct lib80211_crypt_data *crypt)
 652{
 653	struct ieee80211_hdr *hdr;
 654	int res, hdrlen;
 655
 656	if (crypt == NULL || crypt->ops->decrypt_mpdu == NULL)
 657		return 0;
 658
 659	hdr = (struct ieee80211_hdr *) skb->data;
 660	hdrlen = hostap_80211_get_hdrlen(hdr->frame_control);
 661
 662	if (local->tkip_countermeasures &&
 663	    strcmp(crypt->ops->name, "TKIP") == 0) {
 664		if (net_ratelimit()) {
 665			printk(KERN_DEBUG "%s: TKIP countermeasures: dropped "
 666			       "received packet from %pM\n",
 667			       local->dev->name, hdr->addr2);
 668		}
 669		return -1;
 670	}
 671
 672	atomic_inc(&crypt->refcnt);
 673	res = crypt->ops->decrypt_mpdu(skb, hdrlen, crypt->priv);
 674	atomic_dec(&crypt->refcnt);
 675	if (res < 0) {
 676		printk(KERN_DEBUG "%s: decryption failed (SA=%pM) res=%d\n",
 677		       local->dev->name, hdr->addr2, res);
 678		local->comm_tallies.rx_discards_wep_undecryptable++;
 679		return -1;
 680	}
 681
 682	return res;
 683}
 684
 685
 686/* Called only as a tasklet (software IRQ) */
 687static int
 688hostap_rx_frame_decrypt_msdu(local_info_t *local, struct sk_buff *skb,
 689			     int keyidx, struct lib80211_crypt_data *crypt)
 690{
 691	struct ieee80211_hdr *hdr;
 692	int res, hdrlen;
 693
 694	if (crypt == NULL || crypt->ops->decrypt_msdu == NULL)
 695		return 0;
 696
 697	hdr = (struct ieee80211_hdr *) skb->data;
 698	hdrlen = hostap_80211_get_hdrlen(hdr->frame_control);
 699
 700	atomic_inc(&crypt->refcnt);
 701	res = crypt->ops->decrypt_msdu(skb, keyidx, hdrlen, crypt->priv);
 702	atomic_dec(&crypt->refcnt);
 703	if (res < 0) {
 704		printk(KERN_DEBUG "%s: MSDU decryption/MIC verification failed"
 705		       " (SA=%pM keyidx=%d)\n",
 706		       local->dev->name, hdr->addr2, keyidx);
 707		return -1;
 708	}
 709
 710	return 0;
 711}
 712
 713
 714/* All received frames are sent to this function. @skb contains the frame in
 715 * IEEE 802.11 format, i.e., in the format it was sent over air.
 716 * This function is called only as a tasklet (software IRQ). */
 717void hostap_80211_rx(struct net_device *dev, struct sk_buff *skb,
 718		     struct hostap_80211_rx_status *rx_stats)
 719{
 720	struct hostap_interface *iface;
 721	local_info_t *local;
 722	struct ieee80211_hdr *hdr;
 723	size_t hdrlen;
 724	u16 fc, type, stype, sc;
 725	struct net_device *wds = NULL;
 726	unsigned int frag;
 727	u8 *payload;
 728	struct sk_buff *skb2 = NULL;
 729	u16 ethertype;
 730	int frame_authorized = 0;
 731	int from_assoc_ap = 0;
 732	u8 dst[ETH_ALEN];
 733	u8 src[ETH_ALEN];
 734	struct lib80211_crypt_data *crypt = NULL;
 735	void *sta = NULL;
 736	int keyidx = 0;
 737
 738	iface = netdev_priv(dev);
 739	local = iface->local;
 740	iface->stats.rx_packets++;
 741	iface->stats.rx_bytes += skb->len;
 742
 743	/* dev is the master radio device; change this to be the default
 744	 * virtual interface (this may be changed to WDS device below) */
 745	dev = local->ddev;
 746	iface = netdev_priv(dev);
 747
 748	hdr = (struct ieee80211_hdr *) skb->data;
 749
 750	if (skb->len < 10)
 751		goto rx_dropped;
 752
 753	fc = le16_to_cpu(hdr->frame_control);
 754	type = fc & IEEE80211_FCTL_FTYPE;
 755	stype = fc & IEEE80211_FCTL_STYPE;
 756	sc = le16_to_cpu(hdr->seq_ctrl);
 757	frag = sc & IEEE80211_SCTL_FRAG;
 758	hdrlen = hostap_80211_get_hdrlen(hdr->frame_control);
 759
 760	/* Put this code here so that we avoid duplicating it in all
 761	 * Rx paths. - Jean II */
 762#ifdef IW_WIRELESS_SPY		/* defined in iw_handler.h */
 763	/* If spy monitoring on */
 764	if (iface->spy_data.spy_number > 0) {
 765		struct iw_quality wstats;
 766		wstats.level = rx_stats->signal;
 767		wstats.noise = rx_stats->noise;
 768		wstats.updated = IW_QUAL_LEVEL_UPDATED | IW_QUAL_NOISE_UPDATED
 769			| IW_QUAL_QUAL_INVALID | IW_QUAL_DBM;
 770		/* Update spy records */
 771		wireless_spy_update(dev, hdr->addr2, &wstats);
 772	}
 773#endif /* IW_WIRELESS_SPY */
 774	hostap_update_rx_stats(local->ap, hdr, rx_stats);
 775
 776	if (local->iw_mode == IW_MODE_MONITOR) {
 777		monitor_rx(dev, skb, rx_stats);
 778		return;
 779	}
 780
 781	if (local->host_decrypt) {
 782		int idx = 0;
 783		if (skb->len >= hdrlen + 3)
 784			idx = skb->data[hdrlen + 3] >> 6;
 785		crypt = local->crypt_info.crypt[idx];
 786		sta = NULL;
 787
 788		/* Use station specific key to override default keys if the
 789		 * receiver address is a unicast address ("individual RA"). If
 790		 * bcrx_sta_key parameter is set, station specific key is used
 791		 * even with broad/multicast targets (this is against IEEE
 792		 * 802.11, but makes it easier to use different keys with
 793		 * stations that do not support WEP key mapping). */
 794
 795		if (!(hdr->addr1[0] & 0x01) || local->bcrx_sta_key)
 796			(void) hostap_handle_sta_crypto(local, hdr, &crypt,
 797							&sta);
 798
 799		/* allow NULL decrypt to indicate an station specific override
 800		 * for default encryption */
 801		if (crypt && (crypt->ops == NULL ||
 802			      crypt->ops->decrypt_mpdu == NULL))
 803			crypt = NULL;
 804
 805		if (!crypt && (fc & IEEE80211_FCTL_PROTECTED)) {
 806#if 0
 807			/* This seems to be triggered by some (multicast?)
 808			 * frames from other than current BSS, so just drop the
 809			 * frames silently instead of filling system log with
 810			 * these reports. */
 811			printk(KERN_DEBUG "%s: WEP decryption failed (not set)"
 812			       " (SA=%pM)\n",
 813			       local->dev->name, hdr->addr2);
 814#endif
 815			local->comm_tallies.rx_discards_wep_undecryptable++;
 816			goto rx_dropped;
 817		}
 818	}
 819
 820	if (type != IEEE80211_FTYPE_DATA) {
 821		if (type == IEEE80211_FTYPE_MGMT &&
 822		    stype == IEEE80211_STYPE_AUTH &&
 823		    fc & IEEE80211_FCTL_PROTECTED && local->host_decrypt &&
 824		    (keyidx = hostap_rx_frame_decrypt(local, skb, crypt)) < 0)
 825		{
 826			printk(KERN_DEBUG "%s: failed to decrypt mgmt::auth "
 827			       "from %pM\n", dev->name, hdr->addr2);
 828			/* TODO: could inform hostapd about this so that it
 829			 * could send auth failure report */
 830			goto rx_dropped;
 831		}
 832
 833		if (hostap_rx_frame_mgmt(local, skb, rx_stats, type, stype))
 834			goto rx_dropped;
 835		else
 836			goto rx_exit;
 837	}
 838
 839	/* Data frame - extract src/dst addresses */
 840	if (skb->len < IEEE80211_DATA_HDR3_LEN)
 841		goto rx_dropped;
 842
 843	switch (fc & (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) {
 844	case IEEE80211_FCTL_FROMDS:
 845		memcpy(dst, hdr->addr1, ETH_ALEN);
 846		memcpy(src, hdr->addr3, ETH_ALEN);
 847		break;
 848	case IEEE80211_FCTL_TODS:
 849		memcpy(dst, hdr->addr3, ETH_ALEN);
 850		memcpy(src, hdr->addr2, ETH_ALEN);
 851		break;
 852	case IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS:
 853		if (skb->len < IEEE80211_DATA_HDR4_LEN)
 854			goto rx_dropped;
 855		memcpy(dst, hdr->addr3, ETH_ALEN);
 856		memcpy(src, hdr->addr4, ETH_ALEN);
 857		break;
 858	case 0:
 859		memcpy(dst, hdr->addr1, ETH_ALEN);
 860		memcpy(src, hdr->addr2, ETH_ALEN);
 861		break;
 862	}
 863
 864	if (hostap_rx_frame_wds(local, hdr, fc, &wds))
 865		goto rx_dropped;
 866	if (wds)
 867		skb->dev = dev = wds;
 868
 869	if (local->iw_mode == IW_MODE_MASTER && !wds &&
 870	    (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
 871	    IEEE80211_FCTL_FROMDS &&
 872	    local->stadev &&
 873	    memcmp(hdr->addr2, local->assoc_ap_addr, ETH_ALEN) == 0) {
 874		/* Frame from BSSID of the AP for which we are a client */
 875		skb->dev = dev = local->stadev;
 876		from_assoc_ap = 1;
 877	}
 878
 879	if ((local->iw_mode == IW_MODE_MASTER ||
 880	     local->iw_mode == IW_MODE_REPEAT) &&
 881	    !from_assoc_ap) {
 882		switch (hostap_handle_sta_rx(local, dev, skb, rx_stats,
 883					     wds != NULL)) {
 884		case AP_RX_CONTINUE_NOT_AUTHORIZED:
 885			frame_authorized = 0;
 886			break;
 887		case AP_RX_CONTINUE:
 888			frame_authorized = 1;
 889			break;
 890		case AP_RX_DROP:
 891			goto rx_dropped;
 892		case AP_RX_EXIT:
 893			goto rx_exit;
 894		}
 895	}
 896
 897	/* Nullfunc frames may have PS-bit set, so they must be passed to
 898	 * hostap_handle_sta_rx() before being dropped here. */
 899	if (stype != IEEE80211_STYPE_DATA &&
 900	    stype != IEEE80211_STYPE_DATA_CFACK &&
 901	    stype != IEEE80211_STYPE_DATA_CFPOLL &&
 902	    stype != IEEE80211_STYPE_DATA_CFACKPOLL) {
 903		if (stype != IEEE80211_STYPE_NULLFUNC)
 904			printk(KERN_DEBUG "%s: RX: dropped data frame "
 905			       "with no data (type=0x%02x, subtype=0x%02x)\n",
 906			       dev->name, type >> 2, stype >> 4);
 907		goto rx_dropped;
 908	}
 909
 910	/* skb: hdr + (possibly fragmented, possibly encrypted) payload */
 911
 912	if (local->host_decrypt && (fc & IEEE80211_FCTL_PROTECTED) &&
 913	    (keyidx = hostap_rx_frame_decrypt(local, skb, crypt)) < 0)
 914		goto rx_dropped;
 915	hdr = (struct ieee80211_hdr *) skb->data;
 916
 917	/* skb: hdr + (possibly fragmented) plaintext payload */
 918
 919	if (local->host_decrypt && (fc & IEEE80211_FCTL_PROTECTED) &&
 920	    (frag != 0 || (fc & IEEE80211_FCTL_MOREFRAGS))) {
 921		int flen;
 922		struct sk_buff *frag_skb =
 923			prism2_frag_cache_get(local, hdr);
 924		if (!frag_skb) {
 925			printk(KERN_DEBUG "%s: Rx cannot get skb from "
 926			       "fragment cache (morefrag=%d seq=%u frag=%u)\n",
 927			       dev->name, (fc & IEEE80211_FCTL_MOREFRAGS) != 0,
 928			       (sc & IEEE80211_SCTL_SEQ) >> 4, frag);
 929			goto rx_dropped;
 930		}
 931
 932		flen = skb->len;
 933		if (frag != 0)
 934			flen -= hdrlen;
 935
 936		if (frag_skb->tail + flen > frag_skb->end) {
 937			printk(KERN_WARNING "%s: host decrypted and "
 938			       "reassembled frame did not fit skb\n",
 939			       dev->name);
 940			prism2_frag_cache_invalidate(local, hdr);
 941			goto rx_dropped;
 942		}
 943
 944		if (frag == 0) {
 945			/* copy first fragment (including full headers) into
 946			 * beginning of the fragment cache skb */
 947			skb_copy_from_linear_data(skb, skb_put(frag_skb, flen),
 948						  flen);
 949		} else {
 950			/* append frame payload to the end of the fragment
 951			 * cache skb */
 952			skb_copy_from_linear_data_offset(skb, hdrlen,
 953							 skb_put(frag_skb,
 954								 flen), flen);
 955		}
 956		dev_kfree_skb(skb);
 957		skb = NULL;
 958
 959		if (fc & IEEE80211_FCTL_MOREFRAGS) {
 960			/* more fragments expected - leave the skb in fragment
 961			 * cache for now; it will be delivered to upper layers
 962			 * after all fragments have been received */
 963			goto rx_exit;
 964		}
 965
 966		/* this was the last fragment and the frame will be
 967		 * delivered, so remove skb from fragment cache */
 968		skb = frag_skb;
 969		hdr = (struct ieee80211_hdr *) skb->data;
 970		prism2_frag_cache_invalidate(local, hdr);
 971	}
 972
 973	/* skb: hdr + (possible reassembled) full MSDU payload; possibly still
 974	 * encrypted/authenticated */
 975
 976	if (local->host_decrypt && (fc & IEEE80211_FCTL_PROTECTED) &&
 977	    hostap_rx_frame_decrypt_msdu(local, skb, keyidx, crypt))
 978		goto rx_dropped;
 979
 980	hdr = (struct ieee80211_hdr *) skb->data;
 981	if (crypt && !(fc & IEEE80211_FCTL_PROTECTED) && !local->open_wep) {
 982		if (local->ieee_802_1x &&
 983		    hostap_is_eapol_frame(local, skb)) {
 984			/* pass unencrypted EAPOL frames even if encryption is
 985			 * configured */
 986			PDEBUG(DEBUG_EXTRA2, "%s: RX: IEEE 802.1X - passing "
 987			       "unencrypted EAPOL frame\n", local->dev->name);
 988		} else {
 989			printk(KERN_DEBUG "%s: encryption configured, but RX "
 990			       "frame not encrypted (SA=%pM)\n",
 991			       local->dev->name, hdr->addr2);
 992			goto rx_dropped;
 993		}
 994	}
 995
 996	if (local->drop_unencrypted && !(fc & IEEE80211_FCTL_PROTECTED) &&
 997	    !hostap_is_eapol_frame(local, skb)) {
 998		if (net_ratelimit()) {
 999			printk(KERN_DEBUG "%s: dropped unencrypted RX data "
1000			       "frame from %pM (drop_unencrypted=1)\n",
1001			       dev->name, hdr->addr2);
1002		}
1003		goto rx_dropped;
1004	}
1005
1006	/* skb: hdr + (possible reassembled) full plaintext payload */
1007
1008	payload = skb->data + hdrlen;
1009	ethertype = (payload[6] << 8) | payload[7];
1010
1011	/* If IEEE 802.1X is used, check whether the port is authorized to send
1012	 * the received frame. */
1013	if (local->ieee_802_1x && local->iw_mode == IW_MODE_MASTER) {
1014		if (ethertype == ETH_P_PAE) {
1015			PDEBUG(DEBUG_EXTRA2, "%s: RX: IEEE 802.1X frame\n",
1016			       dev->name);
1017			if (local->hostapd && local->apdev) {
1018				/* Send IEEE 802.1X frames to the user
1019				 * space daemon for processing */
1020				prism2_rx_80211(local->apdev, skb, rx_stats,
1021						PRISM2_RX_MGMT);
1022				local->apdevstats.rx_packets++;
1023				local->apdevstats.rx_bytes += skb->len;
1024				goto rx_exit;
1025			}
1026		} else if (!frame_authorized) {
1027			printk(KERN_DEBUG "%s: dropped frame from "
1028			       "unauthorized port (IEEE 802.1X): "
1029			       "ethertype=0x%04x\n",
1030			       dev->name, ethertype);
1031			goto rx_dropped;
1032		}
1033	}
1034
1035	/* convert hdr + possible LLC headers into Ethernet header */
1036	if (skb->len - hdrlen >= 8 &&
1037	    ((memcmp(payload, rfc1042_header, 6) == 0 &&
1038	      ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1039	     memcmp(payload, bridge_tunnel_header, 6) == 0)) {
1040		/* remove RFC1042 or Bridge-Tunnel encapsulation and
1041		 * replace EtherType */
1042		skb_pull(skb, hdrlen + 6);
1043		memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
1044		memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
1045	} else {
1046		__be16 len;
1047		/* Leave Ethernet header part of hdr and full payload */
1048		skb_pull(skb, hdrlen);
1049		len = htons(skb->len);
1050		memcpy(skb_push(skb, 2), &len, 2);
1051		memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
1052		memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
1053	}
1054
1055	if (wds && ((fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
1056		    IEEE80211_FCTL_TODS) &&
1057	    skb->len >= ETH_HLEN + ETH_ALEN) {
1058		/* Non-standard frame: get addr4 from its bogus location after
1059		 * the payload */
1060		skb_copy_from_linear_data_offset(skb, skb->len - ETH_ALEN,
1061						 skb->data + ETH_ALEN,
1062						 ETH_ALEN);
1063		skb_trim(skb, skb->len - ETH_ALEN);
1064	}
1065
1066	dev->stats.rx_packets++;
1067	dev->stats.rx_bytes += skb->len;
1068
1069	if (local->iw_mode == IW_MODE_MASTER && !wds &&
1070	    local->ap->bridge_packets) {
1071		if (dst[0] & 0x01) {
1072			/* copy multicast frame both to the higher layers and
1073			 * to the wireless media */
1074			local->ap->bridged_multicast++;
1075			skb2 = skb_clone(skb, GFP_ATOMIC);
1076			if (skb2 == NULL)
1077				printk(KERN_DEBUG "%s: skb_clone failed for "
1078				       "multicast frame\n", dev->name);
1079		} else if (hostap_is_sta_authorized(local->ap, dst)) {
1080			/* send frame directly to the associated STA using
1081			 * wireless media and not passing to higher layers */
1082			local->ap->bridged_unicast++;
1083			skb2 = skb;
1084			skb = NULL;
1085		}
1086	}
1087
1088	if (skb2 != NULL) {
1089		/* send to wireless media */
1090		skb2->dev = dev;
1091		skb2->protocol = cpu_to_be16(ETH_P_802_3);
1092		skb_reset_mac_header(skb2);
1093		skb_reset_network_header(skb2);
1094		/* skb2->network_header += ETH_HLEN; */
1095		dev_queue_xmit(skb2);
1096	}
1097
1098	if (skb) {
1099		skb->protocol = eth_type_trans(skb, dev);
1100		memset(skb->cb, 0, sizeof(skb->cb));
1101		netif_rx(skb);
1102	}
1103
1104 rx_exit:
1105	if (sta)
1106		hostap_handle_sta_release(sta);
1107	return;
1108
1109 rx_dropped:
1110	dev_kfree_skb(skb);
1111
1112	dev->stats.rx_dropped++;
1113	goto rx_exit;
1114}
1115
1116
1117EXPORT_SYMBOL(hostap_80211_rx);