1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/etherdevice.h>
3 #include <linux/slab.h>
4 #include <linux/export.h>
5 #include <net/lib80211.h>
6 #include <linux/if_arp.h>
7 
8 #include "hostap_80211.h"
9 #include "hostap.h"
10 #include "hostap_ap.h"
11 
12 /* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */
13 /* Ethernet-II snap header (RFC1042 for most EtherTypes) */
14 static unsigned char rfc1042_header[] =
15 { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };
16 /* Bridge-Tunnel header (for EtherTypes ETH_P_AARP and ETH_P_IPX) */
17 static unsigned char bridge_tunnel_header[] =
18 { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0xf8 };
19 /* No encapsulation header if EtherType < 0x600 (=length) */
20 
21 void hostap_dump_rx_80211(const char *name, struct sk_buff *skb,
22 			  struct hostap_80211_rx_status *rx_stats)
23 {
24 	struct ieee80211_hdr *hdr;
25 	u16 fc;
26 
27 	hdr = (struct ieee80211_hdr *) skb->data;
28 
29 	printk(KERN_DEBUG "%s: RX signal=%d noise=%d rate=%d len=%d "
30 	       "jiffies=%ld\n",
31 	       name, rx_stats->signal, rx_stats->noise, rx_stats->rate,
32 	       skb->len, jiffies);
33 
34 	if (skb->len < 2)
35 		return;
36 
37 	fc = le16_to_cpu(hdr->frame_control);
38 	printk(KERN_DEBUG "   FC=0x%04x (type=%d:%d)%s%s",
39 	       fc, (fc & IEEE80211_FCTL_FTYPE) >> 2,
40 	       (fc & IEEE80211_FCTL_STYPE) >> 4,
41 	       fc & IEEE80211_FCTL_TODS ? " [ToDS]" : "",
42 	       fc & IEEE80211_FCTL_FROMDS ? " [FromDS]" : "");
43 
44 	if (skb->len < IEEE80211_DATA_HDR3_LEN) {
45 		printk("\n");
46 		return;
47 	}
48 
49 	printk(" dur=0x%04x seq=0x%04x\n", le16_to_cpu(hdr->duration_id),
50 	       le16_to_cpu(hdr->seq_ctrl));
51 
52 	printk(KERN_DEBUG "   A1=%pM", hdr->addr1);
53 	printk(" A2=%pM", hdr->addr2);
54 	printk(" A3=%pM", hdr->addr3);
55 	if (skb->len >= 30)
56 		printk(" A4=%pM", hdr->addr4);
57 	printk("\n");
58 }
59 
60 
61 /* Send RX frame to netif with 802.11 (and possible prism) header.
62  * Called from hardware or software IRQ context. */
63 int prism2_rx_80211(struct net_device *dev, struct sk_buff *skb,
64 		    struct hostap_80211_rx_status *rx_stats, int type)
65 {
66 	struct hostap_interface *iface;
67 	local_info_t *local;
68 	int hdrlen, phdrlen, head_need, tail_need;
69 	u16 fc;
70 	int prism_header, ret;
71 	struct ieee80211_hdr *fhdr;
72 
73 	iface = netdev_priv(dev);
74 	local = iface->local;
75 
76 	if (dev->type == ARPHRD_IEEE80211_PRISM) {
77 		if (local->monitor_type == PRISM2_MONITOR_PRISM) {
78 			prism_header = 1;
79 			phdrlen = sizeof(struct linux_wlan_ng_prism_hdr);
80 		} else { /* local->monitor_type == PRISM2_MONITOR_CAPHDR */
81 			prism_header = 2;
82 			phdrlen = sizeof(struct linux_wlan_ng_cap_hdr);
83 		}
84 	} else if (dev->type == ARPHRD_IEEE80211_RADIOTAP) {
85 		prism_header = 3;
86 		phdrlen = sizeof(struct hostap_radiotap_rx);
87 	} else {
88 		prism_header = 0;
89 		phdrlen = 0;
90 	}
91 
92 	fhdr = (struct ieee80211_hdr *) skb->data;
93 	fc = le16_to_cpu(fhdr->frame_control);
94 
95 	if (type == PRISM2_RX_MGMT && (fc & IEEE80211_FCTL_VERS)) {
96 		printk(KERN_DEBUG "%s: dropped management frame with header "
97 		       "version %d\n", dev->name, fc & IEEE80211_FCTL_VERS);
98 		dev_kfree_skb_any(skb);
99 		return 0;
100 	}
101 
102 	hdrlen = hostap_80211_get_hdrlen(fhdr->frame_control);
103 
104 	/* check if there is enough room for extra data; if not, expand skb
105 	 * buffer to be large enough for the changes */
106 	head_need = phdrlen;
107 	tail_need = 0;
108 #ifdef PRISM2_ADD_BOGUS_CRC
109 	tail_need += 4;
110 #endif /* PRISM2_ADD_BOGUS_CRC */
111 
112 	head_need -= skb_headroom(skb);
113 	tail_need -= skb_tailroom(skb);
114 
115 	if (head_need > 0 || tail_need > 0) {
116 		if (pskb_expand_head(skb, head_need > 0 ? head_need : 0,
117 				     tail_need > 0 ? tail_need : 0,
118 				     GFP_ATOMIC)) {
119 			printk(KERN_DEBUG "%s: prism2_rx_80211 failed to "
120 			       "reallocate skb buffer\n", dev->name);
121 			dev_kfree_skb_any(skb);
122 			return 0;
123 		}
124 	}
125 
126 	/* We now have an skb with enough head and tail room, so just insert
127 	 * the extra data */
128 
129 #ifdef PRISM2_ADD_BOGUS_CRC
130 	memset(skb_put(skb, 4), 0xff, 4); /* Prism2 strips CRC */
131 #endif /* PRISM2_ADD_BOGUS_CRC */
132 
133 	if (prism_header == 1) {
134 		struct linux_wlan_ng_prism_hdr *hdr;
135 		hdr = 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) \
141 hdr->f.did = LWNG_CAP_DID_BASE | (i << 12); \
142 hdr->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 = skb_push(skb, phdrlen);
157 		memset(hdr, 0, phdrlen);
158 		hdr->version    = htonl(LWNG_CAPHDR_VERSION);
159 		hdr->length     = htonl(phdrlen);
160 		hdr->mactime    = __cpu_to_be64(rx_stats->mac_time);
161 		hdr->hosttime   = __cpu_to_be64(jiffies);
162 		hdr->phytype    = htonl(4); /* dss_dot11_b */
163 		hdr->channel    = htonl(local->channel);
164 		hdr->datarate   = htonl(rx_stats->rate);
165 		hdr->antenna    = htonl(0); /* unknown */
166 		hdr->priority   = htonl(0); /* unknown */
167 		hdr->ssi_type   = htonl(3); /* raw */
168 		hdr->ssi_signal = htonl(rx_stats->signal);
169 		hdr->ssi_noise  = htonl(rx_stats->noise);
170 		hdr->preamble   = htonl(0); /* unknown */
171 		hdr->encoding   = htonl(1); /* cck */
172 	} else if (prism_header == 3) {
173 		struct hostap_radiotap_rx *hdr;
174 		hdr = skb_push(skb, phdrlen);
175 		memset(hdr, 0, phdrlen);
176 		hdr->hdr.it_len = cpu_to_le16(phdrlen);
177 		hdr->hdr.it_present =
178 			cpu_to_le32((1 << IEEE80211_RADIOTAP_TSFT) |
179 				    (1 << IEEE80211_RADIOTAP_CHANNEL) |
180 				    (1 << IEEE80211_RADIOTAP_RATE) |
181 				    (1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL) |
182 				    (1 << IEEE80211_RADIOTAP_DBM_ANTNOISE));
183 		hdr->tsft = cpu_to_le64(rx_stats->mac_time);
184 		hdr->chan_freq = cpu_to_le16(freq_list[local->channel - 1]);
185 		hdr->chan_flags = cpu_to_le16(IEEE80211_CHAN_CCK |
186 						 IEEE80211_CHAN_2GHZ);
187 		hdr->rate = rx_stats->rate / 5;
188 		hdr->dbm_antsignal = rx_stats->signal;
189 		hdr->dbm_antnoise = rx_stats->noise;
190 	}
191 
192 	ret = skb->len - phdrlen;
193 	skb->dev = dev;
194 	skb_reset_mac_header(skb);
195 	skb_pull(skb, hdrlen);
196 	if (prism_header)
197 		skb_pull(skb, phdrlen);
198 	skb->pkt_type = PACKET_OTHERHOST;
199 	skb->protocol = cpu_to_be16(ETH_P_802_2);
200 	memset(skb->cb, 0, sizeof(skb->cb));
201 	netif_rx(skb);
202 
203 	return ret;
204 }
205 
206 
207 /* Called only as a tasklet (software IRQ) */
208 static void monitor_rx(struct net_device *dev, struct sk_buff *skb,
209 		       struct hostap_80211_rx_status *rx_stats)
210 {
211 	int len;
212 
213 	len = prism2_rx_80211(dev, skb, rx_stats, PRISM2_RX_MONITOR);
214 	dev->stats.rx_packets++;
215 	dev->stats.rx_bytes += len;
216 }
217 
218 
219 /* Called only as a tasklet (software IRQ) */
220 static struct prism2_frag_entry *
221 prism2_frag_cache_find(local_info_t *local, unsigned int seq,
222 		       unsigned int frag, u8 *src, u8 *dst)
223 {
224 	struct prism2_frag_entry *entry;
225 	int i;
226 
227 	for (i = 0; i < PRISM2_FRAG_CACHE_LEN; i++) {
228 		entry = &local->frag_cache[i];
229 		if (entry->skb != NULL &&
230 		    time_after(jiffies, entry->first_frag_time + 2 * HZ)) {
231 			printk(KERN_DEBUG "%s: expiring fragment cache entry "
232 			       "seq=%u last_frag=%u\n",
233 			       local->dev->name, entry->seq, entry->last_frag);
234 			dev_kfree_skb(entry->skb);
235 			entry->skb = NULL;
236 		}
237 
238 		if (entry->skb != NULL && entry->seq == seq &&
239 		    (entry->last_frag + 1 == frag || frag == -1) &&
240 		    memcmp(entry->src_addr, src, ETH_ALEN) == 0 &&
241 		    memcmp(entry->dst_addr, dst, ETH_ALEN) == 0)
242 			return entry;
243 	}
244 
245 	return NULL;
246 }
247 
248 
249 /* Called only as a tasklet (software IRQ) */
250 static struct sk_buff *
251 prism2_frag_cache_get(local_info_t *local, struct ieee80211_hdr *hdr)
252 {
253 	struct sk_buff *skb = NULL;
254 	u16 sc;
255 	unsigned int frag, seq;
256 	struct prism2_frag_entry *entry;
257 
258 	sc = le16_to_cpu(hdr->seq_ctrl);
259 	frag = sc & IEEE80211_SCTL_FRAG;
260 	seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
261 
262 	if (frag == 0) {
263 		/* Reserve enough space to fit maximum frame length */
264 		skb = dev_alloc_skb(local->dev->mtu +
265 				    sizeof(struct ieee80211_hdr) +
266 				    8 /* LLC */ +
267 				    2 /* alignment */ +
268 				    8 /* WEP */ + ETH_ALEN /* WDS */);
269 		if (skb == NULL)
270 			return NULL;
271 
272 		entry = &local->frag_cache[local->frag_next_idx];
273 		local->frag_next_idx++;
274 		if (local->frag_next_idx >= PRISM2_FRAG_CACHE_LEN)
275 			local->frag_next_idx = 0;
276 
277 		if (entry->skb != NULL)
278 			dev_kfree_skb(entry->skb);
279 
280 		entry->first_frag_time = jiffies;
281 		entry->seq = seq;
282 		entry->last_frag = frag;
283 		entry->skb = skb;
284 		memcpy(entry->src_addr, hdr->addr2, ETH_ALEN);
285 		memcpy(entry->dst_addr, hdr->addr1, ETH_ALEN);
286 	} else {
287 		/* received a fragment of a frame for which the head fragment
288 		 * should have already been received */
289 		entry = prism2_frag_cache_find(local, seq, frag, hdr->addr2,
290 					       hdr->addr1);
291 		if (entry != NULL) {
292 			entry->last_frag = frag;
293 			skb = entry->skb;
294 		}
295 	}
296 
297 	return skb;
298 }
299 
300 
301 /* Called only as a tasklet (software IRQ) */
302 static int prism2_frag_cache_invalidate(local_info_t *local,
303 					struct ieee80211_hdr *hdr)
304 {
305 	u16 sc;
306 	unsigned int seq;
307 	struct prism2_frag_entry *entry;
308 
309 	sc = le16_to_cpu(hdr->seq_ctrl);
310 	seq = (sc & IEEE80211_SCTL_SEQ) >> 4;
311 
312 	entry = prism2_frag_cache_find(local, seq, -1, hdr->addr2, hdr->addr1);
313 
314 	if (entry == NULL) {
315 		printk(KERN_DEBUG "%s: could not invalidate fragment cache "
316 		       "entry (seq=%u)\n",
317 		       local->dev->name, seq);
318 		return -1;
319 	}
320 
321 	entry->skb = NULL;
322 	return 0;
323 }
324 
325 
326 static struct hostap_bss_info *__hostap_get_bss(local_info_t *local, u8 *bssid,
327 						u8 *ssid, size_t ssid_len)
328 {
329 	struct list_head *ptr;
330 	struct hostap_bss_info *bss;
331 
332 	list_for_each(ptr, &local->bss_list) {
333 		bss = list_entry(ptr, struct hostap_bss_info, list);
334 		if (memcmp(bss->bssid, bssid, ETH_ALEN) == 0 &&
335 		    (ssid == NULL ||
336 		     (ssid_len == bss->ssid_len &&
337 		      memcmp(ssid, bss->ssid, ssid_len) == 0))) {
338 			list_move(&bss->list, &local->bss_list);
339 			return bss;
340 		}
341 	}
342 
343 	return NULL;
344 }
345 
346 
347 static struct hostap_bss_info *__hostap_add_bss(local_info_t *local, u8 *bssid,
348 						u8 *ssid, size_t ssid_len)
349 {
350 	struct hostap_bss_info *bss;
351 
352 	if (local->num_bss_info >= HOSTAP_MAX_BSS_COUNT) {
353 		bss = list_entry(local->bss_list.prev,
354 				 struct hostap_bss_info, list);
355 		list_del(&bss->list);
356 		local->num_bss_info--;
357 	} else {
358 		bss = kmalloc(sizeof(*bss), GFP_ATOMIC);
359 		if (bss == NULL)
360 			return NULL;
361 	}
362 
363 	memset(bss, 0, sizeof(*bss));
364 	memcpy(bss->bssid, bssid, ETH_ALEN);
365 	memcpy(bss->ssid, ssid, ssid_len);
366 	bss->ssid_len = ssid_len;
367 	local->num_bss_info++;
368 	list_add(&bss->list, &local->bss_list);
369 	return bss;
370 }
371 
372 
373 static void __hostap_expire_bss(local_info_t *local)
374 {
375 	struct hostap_bss_info *bss;
376 
377 	while (local->num_bss_info > 0) {
378 		bss = list_entry(local->bss_list.prev,
379 				 struct hostap_bss_info, list);
380 		if (!time_after(jiffies, bss->last_update + 60 * HZ))
381 			break;
382 
383 		list_del(&bss->list);
384 		local->num_bss_info--;
385 		kfree(bss);
386 	}
387 }
388 
389 
390 /* Both IEEE 802.11 Beacon and Probe Response frames have similar structure, so
391  * the same routine can be used to parse both of them. */
392 static void hostap_rx_sta_beacon(local_info_t *local, struct sk_buff *skb,
393 				 int stype)
394 {
395 	struct hostap_ieee80211_mgmt *mgmt;
396 	int left, chan = 0;
397 	u8 *pos;
398 	u8 *ssid = NULL, *wpa = NULL, *rsn = NULL;
399 	size_t ssid_len = 0, wpa_len = 0, rsn_len = 0;
400 	struct hostap_bss_info *bss;
401 
402 	if (skb->len < IEEE80211_MGMT_HDR_LEN + sizeof(mgmt->u.beacon))
403 		return;
404 
405 	mgmt = (struct hostap_ieee80211_mgmt *) skb->data;
406 	pos = mgmt->u.beacon.variable;
407 	left = skb->len - (pos - skb->data);
408 
409 	while (left >= 2) {
410 		if (2 + pos[1] > left)
411 			return; /* parse failed */
412 		switch (*pos) {
413 		case WLAN_EID_SSID:
414 			ssid = pos + 2;
415 			ssid_len = pos[1];
416 			break;
417 		case WLAN_EID_VENDOR_SPECIFIC:
418 			if (pos[1] >= 4 &&
419 			    pos[2] == 0x00 && pos[3] == 0x50 &&
420 			    pos[4] == 0xf2 && pos[5] == 1) {
421 				wpa = pos;
422 				wpa_len = pos[1] + 2;
423 			}
424 			break;
425 		case WLAN_EID_RSN:
426 			rsn = pos;
427 			rsn_len = pos[1] + 2;
428 			break;
429 		case WLAN_EID_DS_PARAMS:
430 			if (pos[1] >= 1)
431 				chan = pos[2];
432 			break;
433 		}
434 		left -= 2 + pos[1];
435 		pos += 2 + pos[1];
436 	}
437 
438 	if (wpa_len > MAX_WPA_IE_LEN)
439 		wpa_len = MAX_WPA_IE_LEN;
440 	if (rsn_len > MAX_WPA_IE_LEN)
441 		rsn_len = MAX_WPA_IE_LEN;
442 	if (ssid_len > sizeof(bss->ssid))
443 		ssid_len = sizeof(bss->ssid);
444 
445 	spin_lock(&local->lock);
446 	bss = __hostap_get_bss(local, mgmt->bssid, ssid, ssid_len);
447 	if (bss == NULL)
448 		bss = __hostap_add_bss(local, mgmt->bssid, ssid, ssid_len);
449 	if (bss) {
450 		bss->last_update = jiffies;
451 		bss->count++;
452 		bss->capab_info = le16_to_cpu(mgmt->u.beacon.capab_info);
453 		if (wpa) {
454 			memcpy(bss->wpa_ie, wpa, wpa_len);
455 			bss->wpa_ie_len = wpa_len;
456 		} else
457 			bss->wpa_ie_len = 0;
458 		if (rsn) {
459 			memcpy(bss->rsn_ie, rsn, rsn_len);
460 			bss->rsn_ie_len = rsn_len;
461 		} else
462 			bss->rsn_ie_len = 0;
463 		bss->chan = chan;
464 	}
465 	__hostap_expire_bss(local);
466 	spin_unlock(&local->lock);
467 }
468 
469 
470 static int
471 hostap_rx_frame_mgmt(local_info_t *local, struct sk_buff *skb,
472 		     struct hostap_80211_rx_status *rx_stats, u16 type,
473 		     u16 stype)
474 {
475 	if (local->iw_mode == IW_MODE_MASTER)
476 		hostap_update_sta_ps(local, (struct ieee80211_hdr *) skb->data);
477 
478 	if (local->hostapd && type == IEEE80211_FTYPE_MGMT) {
479 		if (stype == IEEE80211_STYPE_BEACON &&
480 		    local->iw_mode == IW_MODE_MASTER) {
481 			struct sk_buff *skb2;
482 			/* Process beacon frames also in kernel driver to
483 			 * update STA(AP) table statistics */
484 			skb2 = skb_clone(skb, GFP_ATOMIC);
485 			if (skb2)
486 				hostap_rx(skb2->dev, skb2, rx_stats);
487 		}
488 
489 		/* send management frames to the user space daemon for
490 		 * processing */
491 		local->apdevstats.rx_packets++;
492 		local->apdevstats.rx_bytes += skb->len;
493 		if (local->apdev == NULL)
494 			return -1;
495 		prism2_rx_80211(local->apdev, skb, rx_stats, PRISM2_RX_MGMT);
496 		return 0;
497 	}
498 
499 	if (local->iw_mode == IW_MODE_MASTER) {
500 		if (type != IEEE80211_FTYPE_MGMT &&
501 		    type != IEEE80211_FTYPE_CTL) {
502 			printk(KERN_DEBUG "%s: unknown management frame "
503 			       "(type=0x%02x, stype=0x%02x) dropped\n",
504 			       skb->dev->name, type >> 2, stype >> 4);
505 			return -1;
506 		}
507 
508 		hostap_rx(skb->dev, skb, rx_stats);
509 		return 0;
510 	} else if (type == IEEE80211_FTYPE_MGMT &&
511 		   (stype == IEEE80211_STYPE_BEACON ||
512 		    stype == IEEE80211_STYPE_PROBE_RESP)) {
513 		hostap_rx_sta_beacon(local, skb, stype);
514 		return -1;
515 	} else if (type == IEEE80211_FTYPE_MGMT &&
516 		   (stype == IEEE80211_STYPE_ASSOC_RESP ||
517 		    stype == IEEE80211_STYPE_REASSOC_RESP)) {
518 		/* Ignore (Re)AssocResp silently since these are not currently
519 		 * needed but are still received when WPA/RSN mode is enabled.
520 		 */
521 		return -1;
522 	} else {
523 		printk(KERN_DEBUG "%s: hostap_rx_frame_mgmt: dropped unhandled"
524 		       " management frame in non-Host AP mode (type=%d:%d)\n",
525 		       skb->dev->name, type >> 2, stype >> 4);
526 		return -1;
527 	}
528 }
529 
530 
531 /* Called only as a tasklet (software IRQ) */
532 static struct net_device *prism2_rx_get_wds(local_info_t *local,
533 						   u8 *addr)
534 {
535 	struct hostap_interface *iface = NULL;
536 	struct list_head *ptr;
537 
538 	read_lock_bh(&local->iface_lock);
539 	list_for_each(ptr, &local->hostap_interfaces) {
540 		iface = list_entry(ptr, struct hostap_interface, list);
541 		if (iface->type == HOSTAP_INTERFACE_WDS &&
542 		    memcmp(iface->u.wds.remote_addr, addr, ETH_ALEN) == 0)
543 			break;
544 		iface = NULL;
545 	}
546 	read_unlock_bh(&local->iface_lock);
547 
548 	return iface ? iface->dev : NULL;
549 }
550 
551 
552 static int
553 hostap_rx_frame_wds(local_info_t *local, struct ieee80211_hdr *hdr, u16 fc,
554 		    struct net_device **wds)
555 {
556 	/* FIX: is this really supposed to accept WDS frames only in Master
557 	 * mode? What about Repeater or Managed with WDS frames? */
558 	if ((fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) !=
559 	    (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS) &&
560 	    (local->iw_mode != IW_MODE_MASTER || !(fc & IEEE80211_FCTL_TODS)))
561 		return 0; /* not a WDS frame */
562 
563 	/* Possible WDS frame: either IEEE 802.11 compliant (if FromDS)
564 	 * or own non-standard frame with 4th address after payload */
565 	if (!ether_addr_equal(hdr->addr1, local->dev->dev_addr) &&
566 	    (hdr->addr1[0] != 0xff || hdr->addr1[1] != 0xff ||
567 	     hdr->addr1[2] != 0xff || hdr->addr1[3] != 0xff ||
568 	     hdr->addr1[4] != 0xff || hdr->addr1[5] != 0xff)) {
569 		/* RA (or BSSID) is not ours - drop */
570 		PDEBUG(DEBUG_EXTRA2, "%s: received WDS frame with "
571 		       "not own or broadcast %s=%pM\n",
572 		       local->dev->name,
573 		       fc & IEEE80211_FCTL_FROMDS ? "RA" : "BSSID",
574 		       hdr->addr1);
575 		return -1;
576 	}
577 
578 	/* check if the frame came from a registered WDS connection */
579 	*wds = prism2_rx_get_wds(local, hdr->addr2);
580 	if (*wds == NULL && fc & IEEE80211_FCTL_FROMDS &&
581 	    (local->iw_mode != IW_MODE_INFRA ||
582 	     !(local->wds_type & HOSTAP_WDS_AP_CLIENT) ||
583 	     memcmp(hdr->addr2, local->bssid, ETH_ALEN) != 0)) {
584 		/* require that WDS link has been registered with TA or the
585 		 * frame is from current AP when using 'AP client mode' */
586 		PDEBUG(DEBUG_EXTRA, "%s: received WDS[4 addr] frame "
587 		       "from unknown TA=%pM\n",
588 		       local->dev->name, hdr->addr2);
589 		if (local->ap && local->ap->autom_ap_wds)
590 			hostap_wds_link_oper(local, hdr->addr2, WDS_ADD);
591 		return -1;
592 	}
593 
594 	if (*wds && !(fc & IEEE80211_FCTL_FROMDS) && local->ap &&
595 	    hostap_is_sta_assoc(local->ap, hdr->addr2)) {
596 		/* STA is actually associated with us even though it has a
597 		 * registered WDS link. Assume it is in 'AP client' mode.
598 		 * Since this is a 3-addr frame, assume it is not (bogus) WDS
599 		 * frame and process it like any normal ToDS frame from
600 		 * associated STA. */
601 		*wds = NULL;
602 	}
603 
604 	return 0;
605 }
606 
607 
608 static int hostap_is_eapol_frame(local_info_t *local, struct sk_buff *skb)
609 {
610 	struct net_device *dev = local->dev;
611 	u16 fc, ethertype;
612 	struct ieee80211_hdr *hdr;
613 	u8 *pos;
614 
615 	if (skb->len < 24)
616 		return 0;
617 
618 	hdr = (struct ieee80211_hdr *) skb->data;
619 	fc = le16_to_cpu(hdr->frame_control);
620 
621 	/* check that the frame is unicast frame to us */
622 	if ((fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
623 	    IEEE80211_FCTL_TODS &&
624 	    ether_addr_equal(hdr->addr1, dev->dev_addr) &&
625 	    ether_addr_equal(hdr->addr3, dev->dev_addr)) {
626 		/* ToDS frame with own addr BSSID and DA */
627 	} else if ((fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
628 		   IEEE80211_FCTL_FROMDS &&
629 		   ether_addr_equal(hdr->addr1, dev->dev_addr)) {
630 		/* FromDS frame with own addr as DA */
631 	} else
632 		return 0;
633 
634 	if (skb->len < 24 + 8)
635 		return 0;
636 
637 	/* check for port access entity Ethernet type */
638 	pos = skb->data + 24;
639 	ethertype = (pos[6] << 8) | pos[7];
640 	if (ethertype == ETH_P_PAE)
641 		return 1;
642 
643 	return 0;
644 }
645 
646 
647 /* Called only as a tasklet (software IRQ) */
648 static int
649 hostap_rx_frame_decrypt(local_info_t *local, struct sk_buff *skb,
650 			struct lib80211_crypt_data *crypt)
651 {
652 	struct ieee80211_hdr *hdr;
653 	int res, hdrlen;
654 
655 	if (crypt == NULL || crypt->ops->decrypt_mpdu == NULL)
656 		return 0;
657 
658 	hdr = (struct ieee80211_hdr *) skb->data;
659 	hdrlen = hostap_80211_get_hdrlen(hdr->frame_control);
660 
661 	if (local->tkip_countermeasures &&
662 	    strcmp(crypt->ops->name, "TKIP") == 0) {
663 		if (net_ratelimit()) {
664 			printk(KERN_DEBUG "%s: TKIP countermeasures: dropped "
665 			       "received packet from %pM\n",
666 			       local->dev->name, hdr->addr2);
667 		}
668 		return -1;
669 	}
670 
671 	atomic_inc(&crypt->refcnt);
672 	res = crypt->ops->decrypt_mpdu(skb, hdrlen, crypt->priv);
673 	atomic_dec(&crypt->refcnt);
674 	if (res < 0) {
675 		printk(KERN_DEBUG "%s: decryption failed (SA=%pM) res=%d\n",
676 		       local->dev->name, hdr->addr2, res);
677 		local->comm_tallies.rx_discards_wep_undecryptable++;
678 		return -1;
679 	}
680 
681 	return res;
682 }
683 
684 
685 /* Called only as a tasklet (software IRQ) */
686 static int
687 hostap_rx_frame_decrypt_msdu(local_info_t *local, struct sk_buff *skb,
688 			     int keyidx, struct lib80211_crypt_data *crypt)
689 {
690 	struct ieee80211_hdr *hdr;
691 	int res, hdrlen;
692 
693 	if (crypt == NULL || crypt->ops->decrypt_msdu == NULL)
694 		return 0;
695 
696 	hdr = (struct ieee80211_hdr *) skb->data;
697 	hdrlen = hostap_80211_get_hdrlen(hdr->frame_control);
698 
699 	atomic_inc(&crypt->refcnt);
700 	res = crypt->ops->decrypt_msdu(skb, keyidx, hdrlen, crypt->priv);
701 	atomic_dec(&crypt->refcnt);
702 	if (res < 0) {
703 		printk(KERN_DEBUG "%s: MSDU decryption/MIC verification failed"
704 		       " (SA=%pM keyidx=%d)\n",
705 		       local->dev->name, hdr->addr2, keyidx);
706 		return -1;
707 	}
708 
709 	return 0;
710 }
711 
712 
713 /* All received frames are sent to this function. @skb contains the frame in
714  * IEEE 802.11 format, i.e., in the format it was sent over air.
715  * This function is called only as a tasklet (software IRQ). */
716 void hostap_80211_rx(struct net_device *dev, struct sk_buff *skb,
717 		     struct hostap_80211_rx_status *rx_stats)
718 {
719 	struct hostap_interface *iface;
720 	local_info_t *local;
721 	struct ieee80211_hdr *hdr;
722 	size_t hdrlen;
723 	u16 fc, type, stype, sc;
724 	struct net_device *wds = NULL;
725 	unsigned int frag;
726 	u8 *payload;
727 	struct sk_buff *skb2 = NULL;
728 	u16 ethertype;
729 	int frame_authorized = 0;
730 	int from_assoc_ap = 0;
731 	u8 dst[ETH_ALEN];
732 	u8 src[ETH_ALEN];
733 	struct lib80211_crypt_data *crypt = NULL;
734 	void *sta = NULL;
735 	int keyidx = 0;
736 
737 	iface = netdev_priv(dev);
738 	local = iface->local;
739 	iface->stats.rx_packets++;
740 	iface->stats.rx_bytes += skb->len;
741 
742 	/* dev is the master radio device; change this to be the default
743 	 * virtual interface (this may be changed to WDS device below) */
744 	dev = local->ddev;
745 	iface = netdev_priv(dev);
746 
747 	hdr = (struct ieee80211_hdr *) skb->data;
748 
749 	if (skb->len < 10)
750 		goto rx_dropped;
751 
752 	fc = le16_to_cpu(hdr->frame_control);
753 	type = fc & IEEE80211_FCTL_FTYPE;
754 	stype = fc & IEEE80211_FCTL_STYPE;
755 	sc = le16_to_cpu(hdr->seq_ctrl);
756 	frag = sc & IEEE80211_SCTL_FRAG;
757 	hdrlen = hostap_80211_get_hdrlen(hdr->frame_control);
758 
759 	/* Put this code here so that we avoid duplicating it in all
760 	 * Rx paths. - Jean II */
761 #ifdef IW_WIRELESS_SPY		/* defined in iw_handler.h */
762 	/* If spy monitoring on */
763 	if (iface->spy_data.spy_number > 0) {
764 		struct iw_quality wstats;
765 		wstats.level = rx_stats->signal;
766 		wstats.noise = rx_stats->noise;
767 		wstats.updated = IW_QUAL_LEVEL_UPDATED | IW_QUAL_NOISE_UPDATED
768 			| IW_QUAL_QUAL_INVALID | IW_QUAL_DBM;
769 		/* Update spy records */
770 		wireless_spy_update(dev, hdr->addr2, &wstats);
771 	}
772 #endif /* IW_WIRELESS_SPY */
773 	hostap_update_rx_stats(local->ap, hdr, rx_stats);
774 
775 	if (local->iw_mode == IW_MODE_MONITOR) {
776 		monitor_rx(dev, skb, rx_stats);
777 		return;
778 	}
779 
780 	if (local->host_decrypt) {
781 		int idx = 0;
782 		if (skb->len >= hdrlen + 3)
783 			idx = skb->data[hdrlen + 3] >> 6;
784 		crypt = local->crypt_info.crypt[idx];
785 		sta = NULL;
786 
787 		/* Use station specific key to override default keys if the
788 		 * receiver address is a unicast address ("individual RA"). If
789 		 * bcrx_sta_key parameter is set, station specific key is used
790 		 * even with broad/multicast targets (this is against IEEE
791 		 * 802.11, but makes it easier to use different keys with
792 		 * stations that do not support WEP key mapping). */
793 
794 		if (!(hdr->addr1[0] & 0x01) || local->bcrx_sta_key)
795 			(void) hostap_handle_sta_crypto(local, hdr, &crypt,
796 							&sta);
797 
798 		/* allow NULL decrypt to indicate an station specific override
799 		 * for default encryption */
800 		if (crypt && (crypt->ops == NULL ||
801 			      crypt->ops->decrypt_mpdu == NULL))
802 			crypt = NULL;
803 
804 		if (!crypt && (fc & IEEE80211_FCTL_PROTECTED)) {
805 #if 0
806 			/* This seems to be triggered by some (multicast?)
807 			 * frames from other than current BSS, so just drop the
808 			 * frames silently instead of filling system log with
809 			 * these reports. */
810 			printk(KERN_DEBUG "%s: WEP decryption failed (not set)"
811 			       " (SA=%pM)\n",
812 			       local->dev->name, hdr->addr2);
813 #endif
814 			local->comm_tallies.rx_discards_wep_undecryptable++;
815 			goto rx_dropped;
816 		}
817 	}
818 
819 	if (type != IEEE80211_FTYPE_DATA) {
820 		if (type == IEEE80211_FTYPE_MGMT &&
821 		    stype == IEEE80211_STYPE_AUTH &&
822 		    fc & IEEE80211_FCTL_PROTECTED && local->host_decrypt &&
823 		    (keyidx = hostap_rx_frame_decrypt(local, skb, crypt)) < 0)
824 		{
825 			printk(KERN_DEBUG "%s: failed to decrypt mgmt::auth "
826 			       "from %pM\n", dev->name, hdr->addr2);
827 			/* TODO: could inform hostapd about this so that it
828 			 * could send auth failure report */
829 			goto rx_dropped;
830 		}
831 
832 		if (hostap_rx_frame_mgmt(local, skb, rx_stats, type, stype))
833 			goto rx_dropped;
834 		else
835 			goto rx_exit;
836 	}
837 
838 	/* Data frame - extract src/dst addresses */
839 	if (skb->len < IEEE80211_DATA_HDR3_LEN)
840 		goto rx_dropped;
841 
842 	switch (fc & (IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS)) {
843 	case IEEE80211_FCTL_FROMDS:
844 		memcpy(dst, hdr->addr1, ETH_ALEN);
845 		memcpy(src, hdr->addr3, ETH_ALEN);
846 		break;
847 	case IEEE80211_FCTL_TODS:
848 		memcpy(dst, hdr->addr3, ETH_ALEN);
849 		memcpy(src, hdr->addr2, ETH_ALEN);
850 		break;
851 	case IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS:
852 		if (skb->len < IEEE80211_DATA_HDR4_LEN)
853 			goto rx_dropped;
854 		memcpy(dst, hdr->addr3, ETH_ALEN);
855 		memcpy(src, hdr->addr4, ETH_ALEN);
856 		break;
857 	default:
858 		memcpy(dst, hdr->addr1, ETH_ALEN);
859 		memcpy(src, hdr->addr2, ETH_ALEN);
860 		break;
861 	}
862 
863 	if (hostap_rx_frame_wds(local, hdr, fc, &wds))
864 		goto rx_dropped;
865 	if (wds)
866 		skb->dev = dev = wds;
867 
868 	if (local->iw_mode == IW_MODE_MASTER && !wds &&
869 	    (fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
870 	    IEEE80211_FCTL_FROMDS &&
871 	    local->stadev &&
872 	    memcmp(hdr->addr2, local->assoc_ap_addr, ETH_ALEN) == 0) {
873 		/* Frame from BSSID of the AP for which we are a client */
874 		skb->dev = dev = local->stadev;
875 		from_assoc_ap = 1;
876 	}
877 
878 	if ((local->iw_mode == IW_MODE_MASTER ||
879 	     local->iw_mode == IW_MODE_REPEAT) &&
880 	    !from_assoc_ap) {
881 		switch (hostap_handle_sta_rx(local, dev, skb, rx_stats,
882 					     wds != NULL)) {
883 		case AP_RX_CONTINUE_NOT_AUTHORIZED:
884 			frame_authorized = 0;
885 			break;
886 		case AP_RX_CONTINUE:
887 			frame_authorized = 1;
888 			break;
889 		case AP_RX_DROP:
890 			goto rx_dropped;
891 		case AP_RX_EXIT:
892 			goto rx_exit;
893 		}
894 	}
895 
896 	/* Nullfunc frames may have PS-bit set, so they must be passed to
897 	 * hostap_handle_sta_rx() before being dropped here. */
898 	if (stype != IEEE80211_STYPE_DATA &&
899 	    stype != IEEE80211_STYPE_DATA_CFACK &&
900 	    stype != IEEE80211_STYPE_DATA_CFPOLL &&
901 	    stype != IEEE80211_STYPE_DATA_CFACKPOLL) {
902 		if (stype != IEEE80211_STYPE_NULLFUNC)
903 			printk(KERN_DEBUG "%s: RX: dropped data frame "
904 			       "with no data (type=0x%02x, subtype=0x%02x)\n",
905 			       dev->name, type >> 2, stype >> 4);
906 		goto rx_dropped;
907 	}
908 
909 	/* skb: hdr + (possibly fragmented, possibly encrypted) payload */
910 
911 	if (local->host_decrypt && (fc & IEEE80211_FCTL_PROTECTED) &&
912 	    (keyidx = hostap_rx_frame_decrypt(local, skb, crypt)) < 0)
913 		goto rx_dropped;
914 	hdr = (struct ieee80211_hdr *) skb->data;
915 
916 	/* skb: hdr + (possibly fragmented) plaintext payload */
917 
918 	if (local->host_decrypt && (fc & IEEE80211_FCTL_PROTECTED) &&
919 	    (frag != 0 || (fc & IEEE80211_FCTL_MOREFRAGS))) {
920 		int flen;
921 		struct sk_buff *frag_skb =
922 			prism2_frag_cache_get(local, hdr);
923 		if (!frag_skb) {
924 			printk(KERN_DEBUG "%s: Rx cannot get skb from "
925 			       "fragment cache (morefrag=%d seq=%u frag=%u)\n",
926 			       dev->name, (fc & IEEE80211_FCTL_MOREFRAGS) != 0,
927 			       (sc & IEEE80211_SCTL_SEQ) >> 4, frag);
928 			goto rx_dropped;
929 		}
930 
931 		flen = skb->len;
932 		if (frag != 0)
933 			flen -= hdrlen;
934 
935 		if (frag_skb->tail + flen > frag_skb->end) {
936 			printk(KERN_WARNING "%s: host decrypted and "
937 			       "reassembled frame did not fit skb\n",
938 			       dev->name);
939 			prism2_frag_cache_invalidate(local, hdr);
940 			goto rx_dropped;
941 		}
942 
943 		if (frag == 0) {
944 			/* copy first fragment (including full headers) into
945 			 * beginning of the fragment cache skb */
946 			skb_copy_from_linear_data(skb, skb_put(frag_skb, flen),
947 						  flen);
948 		} else {
949 			/* append frame payload to the end of the fragment
950 			 * cache skb */
951 			skb_copy_from_linear_data_offset(skb, hdrlen,
952 							 skb_put(frag_skb,
953 								 flen), flen);
954 		}
955 		dev_kfree_skb(skb);
956 		skb = NULL;
957 
958 		if (fc & IEEE80211_FCTL_MOREFRAGS) {
959 			/* more fragments expected - leave the skb in fragment
960 			 * cache for now; it will be delivered to upper layers
961 			 * after all fragments have been received */
962 			goto rx_exit;
963 		}
964 
965 		/* this was the last fragment and the frame will be
966 		 * delivered, so remove skb from fragment cache */
967 		skb = frag_skb;
968 		hdr = (struct ieee80211_hdr *) skb->data;
969 		prism2_frag_cache_invalidate(local, hdr);
970 	}
971 
972 	/* skb: hdr + (possible reassembled) full MSDU payload; possibly still
973 	 * encrypted/authenticated */
974 
975 	if (local->host_decrypt && (fc & IEEE80211_FCTL_PROTECTED) &&
976 	    hostap_rx_frame_decrypt_msdu(local, skb, keyidx, crypt))
977 		goto rx_dropped;
978 
979 	hdr = (struct ieee80211_hdr *) skb->data;
980 	if (crypt && !(fc & IEEE80211_FCTL_PROTECTED) && !local->open_wep) {
981 		if (local->ieee_802_1x &&
982 		    hostap_is_eapol_frame(local, skb)) {
983 			/* pass unencrypted EAPOL frames even if encryption is
984 			 * configured */
985 			PDEBUG(DEBUG_EXTRA2, "%s: RX: IEEE 802.1X - passing "
986 			       "unencrypted EAPOL frame\n", local->dev->name);
987 		} else {
988 			printk(KERN_DEBUG "%s: encryption configured, but RX "
989 			       "frame not encrypted (SA=%pM)\n",
990 			       local->dev->name, hdr->addr2);
991 			goto rx_dropped;
992 		}
993 	}
994 
995 	if (local->drop_unencrypted && !(fc & IEEE80211_FCTL_PROTECTED) &&
996 	    !hostap_is_eapol_frame(local, skb)) {
997 		if (net_ratelimit()) {
998 			printk(KERN_DEBUG "%s: dropped unencrypted RX data "
999 			       "frame from %pM (drop_unencrypted=1)\n",
1000 			       dev->name, hdr->addr2);
1001 		}
1002 		goto rx_dropped;
1003 	}
1004 
1005 	/* skb: hdr + (possible reassembled) full plaintext payload */
1006 
1007 	payload = skb->data + hdrlen;
1008 	ethertype = (payload[6] << 8) | payload[7];
1009 
1010 	/* If IEEE 802.1X is used, check whether the port is authorized to send
1011 	 * the received frame. */
1012 	if (local->ieee_802_1x && local->iw_mode == IW_MODE_MASTER) {
1013 		if (ethertype == ETH_P_PAE) {
1014 			PDEBUG(DEBUG_EXTRA2, "%s: RX: IEEE 802.1X frame\n",
1015 			       dev->name);
1016 			if (local->hostapd && local->apdev) {
1017 				/* Send IEEE 802.1X frames to the user
1018 				 * space daemon for processing */
1019 				prism2_rx_80211(local->apdev, skb, rx_stats,
1020 						PRISM2_RX_MGMT);
1021 				local->apdevstats.rx_packets++;
1022 				local->apdevstats.rx_bytes += skb->len;
1023 				goto rx_exit;
1024 			}
1025 		} else if (!frame_authorized) {
1026 			printk(KERN_DEBUG "%s: dropped frame from "
1027 			       "unauthorized port (IEEE 802.1X): "
1028 			       "ethertype=0x%04x\n",
1029 			       dev->name, ethertype);
1030 			goto rx_dropped;
1031 		}
1032 	}
1033 
1034 	/* convert hdr + possible LLC headers into Ethernet header */
1035 	if (skb->len - hdrlen >= 8 &&
1036 	    ((memcmp(payload, rfc1042_header, 6) == 0 &&
1037 	      ethertype != ETH_P_AARP && ethertype != ETH_P_IPX) ||
1038 	     memcmp(payload, bridge_tunnel_header, 6) == 0)) {
1039 		/* remove RFC1042 or Bridge-Tunnel encapsulation and
1040 		 * replace EtherType */
1041 		skb_pull(skb, hdrlen + 6);
1042 		memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
1043 		memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
1044 	} else {
1045 		__be16 len;
1046 		/* Leave Ethernet header part of hdr and full payload */
1047 		skb_pull(skb, hdrlen);
1048 		len = htons(skb->len);
1049 		memcpy(skb_push(skb, 2), &len, 2);
1050 		memcpy(skb_push(skb, ETH_ALEN), src, ETH_ALEN);
1051 		memcpy(skb_push(skb, ETH_ALEN), dst, ETH_ALEN);
1052 	}
1053 
1054 	if (wds && ((fc & (IEEE80211_FCTL_TODS | IEEE80211_FCTL_FROMDS)) ==
1055 		    IEEE80211_FCTL_TODS) &&
1056 	    skb->len >= ETH_HLEN + ETH_ALEN) {
1057 		/* Non-standard frame: get addr4 from its bogus location after
1058 		 * the payload */
1059 		skb_copy_from_linear_data_offset(skb, skb->len - ETH_ALEN,
1060 						 skb->data + ETH_ALEN,
1061 						 ETH_ALEN);
1062 		skb_trim(skb, skb->len - ETH_ALEN);
1063 	}
1064 
1065 	dev->stats.rx_packets++;
1066 	dev->stats.rx_bytes += skb->len;
1067 
1068 	if (local->iw_mode == IW_MODE_MASTER && !wds &&
1069 	    local->ap->bridge_packets) {
1070 		if (dst[0] & 0x01) {
1071 			/* copy multicast frame both to the higher layers and
1072 			 * to the wireless media */
1073 			local->ap->bridged_multicast++;
1074 			skb2 = skb_clone(skb, GFP_ATOMIC);
1075 			if (skb2 == NULL)
1076 				printk(KERN_DEBUG "%s: skb_clone failed for "
1077 				       "multicast frame\n", dev->name);
1078 		} else if (hostap_is_sta_authorized(local->ap, dst)) {
1079 			/* send frame directly to the associated STA using
1080 			 * wireless media and not passing to higher layers */
1081 			local->ap->bridged_unicast++;
1082 			skb2 = skb;
1083 			skb = NULL;
1084 		}
1085 	}
1086 
1087 	if (skb2 != NULL) {
1088 		/* send to wireless media */
1089 		skb2->dev = dev;
1090 		skb2->protocol = cpu_to_be16(ETH_P_802_3);
1091 		skb_reset_mac_header(skb2);
1092 		skb_reset_network_header(skb2);
1093 		/* skb2->network_header += ETH_HLEN; */
1094 		dev_queue_xmit(skb2);
1095 	}
1096 
1097 	if (skb) {
1098 		skb->protocol = eth_type_trans(skb, dev);
1099 		memset(skb->cb, 0, sizeof(skb->cb));
1100 		netif_rx(skb);
1101 	}
1102 
1103  rx_exit:
1104 	if (sta)
1105 		hostap_handle_sta_release(sta);
1106 	return;
1107 
1108  rx_dropped:
1109 	dev_kfree_skb(skb);
1110 
1111 	dev->stats.rx_dropped++;
1112 	goto rx_exit;
1113 }
1114 
1115 
1116 EXPORT_SYMBOL(hostap_80211_rx);
1117