1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/slab.h>
3 #include <linux/export.h>
4 #include <linux/etherdevice.h>
5
6 #include "hostap_80211.h"
7 #include "hostap_common.h"
8 #include "hostap_wlan.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
hostap_dump_tx_80211(const char * name,struct sk_buff * skb)21 void hostap_dump_tx_80211(const char *name, struct sk_buff *skb)
22 {
23 struct ieee80211_hdr *hdr;
24 u16 fc;
25
26 hdr = (struct ieee80211_hdr *) skb->data;
27
28 printk(KERN_DEBUG "%s: TX len=%d jiffies=%ld\n",
29 name, skb->len, jiffies);
30
31 if (skb->len < 2)
32 return;
33
34 fc = le16_to_cpu(hdr->frame_control);
35 printk(KERN_DEBUG " FC=0x%04x (type=%d:%d)%s%s",
36 fc, (fc & IEEE80211_FCTL_FTYPE) >> 2,
37 (fc & IEEE80211_FCTL_STYPE) >> 4,
38 fc & IEEE80211_FCTL_TODS ? " [ToDS]" : "",
39 fc & IEEE80211_FCTL_FROMDS ? " [FromDS]" : "");
40
41 if (skb->len < IEEE80211_DATA_HDR3_LEN) {
42 printk("\n");
43 return;
44 }
45
46 printk(" dur=0x%04x seq=0x%04x\n", le16_to_cpu(hdr->duration_id),
47 le16_to_cpu(hdr->seq_ctrl));
48
49 printk(KERN_DEBUG " A1=%pM", hdr->addr1);
50 printk(" A2=%pM", hdr->addr2);
51 printk(" A3=%pM", hdr->addr3);
52 if (skb->len >= 30)
53 printk(" A4=%pM", hdr->addr4);
54 printk("\n");
55 }
56
57
58 /* hard_start_xmit function for data interfaces (wlan#, wlan#wds#, wlan#sta)
59 * Convert Ethernet header into a suitable IEEE 802.11 header depending on
60 * device configuration. */
hostap_data_start_xmit(struct sk_buff * skb,struct net_device * dev)61 netdev_tx_t hostap_data_start_xmit(struct sk_buff *skb,
62 struct net_device *dev)
63 {
64 struct hostap_interface *iface;
65 local_info_t *local;
66 int need_headroom, need_tailroom = 0;
67 struct ieee80211_hdr hdr;
68 u16 fc, ethertype = 0;
69 enum {
70 WDS_NO = 0, WDS_OWN_FRAME, WDS_COMPLIANT_FRAME
71 } use_wds = WDS_NO;
72 u8 *encaps_data;
73 int hdr_len, encaps_len, skip_header_bytes;
74 int to_assoc_ap = 0;
75 struct hostap_skb_tx_data *meta;
76
77 iface = netdev_priv(dev);
78 local = iface->local;
79
80 if (skb->len < ETH_HLEN) {
81 printk(KERN_DEBUG "%s: hostap_data_start_xmit: short skb "
82 "(len=%d)\n", dev->name, skb->len);
83 kfree_skb(skb);
84 return NETDEV_TX_OK;
85 }
86
87 if (local->ddev != dev) {
88 use_wds = (local->iw_mode == IW_MODE_MASTER &&
89 !(local->wds_type & HOSTAP_WDS_STANDARD_FRAME)) ?
90 WDS_OWN_FRAME : WDS_COMPLIANT_FRAME;
91 if (dev == local->stadev) {
92 to_assoc_ap = 1;
93 use_wds = WDS_NO;
94 } else if (dev == local->apdev) {
95 printk(KERN_DEBUG "%s: prism2_tx: trying to use "
96 "AP device with Ethernet net dev\n", dev->name);
97 kfree_skb(skb);
98 return NETDEV_TX_OK;
99 }
100 } else {
101 if (local->iw_mode == IW_MODE_REPEAT) {
102 printk(KERN_DEBUG "%s: prism2_tx: trying to use "
103 "non-WDS link in Repeater mode\n", dev->name);
104 kfree_skb(skb);
105 return NETDEV_TX_OK;
106 } else if (local->iw_mode == IW_MODE_INFRA &&
107 (local->wds_type & HOSTAP_WDS_AP_CLIENT) &&
108 !ether_addr_equal(skb->data + ETH_ALEN, dev->dev_addr)) {
109 /* AP client mode: send frames with foreign src addr
110 * using 4-addr WDS frames */
111 use_wds = WDS_COMPLIANT_FRAME;
112 }
113 }
114
115 /* Incoming skb->data: dst_addr[6], src_addr[6], proto[2], payload
116 * ==>
117 * Prism2 TX frame with 802.11 header:
118 * txdesc (address order depending on used mode; includes dst_addr and
119 * src_addr), possible encapsulation (RFC1042/Bridge-Tunnel;
120 * proto[2], payload {, possible addr4[6]} */
121
122 ethertype = (skb->data[12] << 8) | skb->data[13];
123
124 memset(&hdr, 0, sizeof(hdr));
125
126 /* Length of data after IEEE 802.11 header */
127 encaps_data = NULL;
128 encaps_len = 0;
129 skip_header_bytes = ETH_HLEN;
130 if (ethertype == ETH_P_AARP || ethertype == ETH_P_IPX) {
131 encaps_data = bridge_tunnel_header;
132 encaps_len = sizeof(bridge_tunnel_header);
133 skip_header_bytes -= 2;
134 } else if (ethertype >= 0x600) {
135 encaps_data = rfc1042_header;
136 encaps_len = sizeof(rfc1042_header);
137 skip_header_bytes -= 2;
138 }
139
140 fc = IEEE80211_FTYPE_DATA | IEEE80211_STYPE_DATA;
141 hdr_len = IEEE80211_DATA_HDR3_LEN;
142
143 if (use_wds != WDS_NO) {
144 /* Note! Prism2 station firmware has problems with sending real
145 * 802.11 frames with four addresses; until these problems can
146 * be fixed or worked around, 4-addr frames needed for WDS are
147 * using incompatible format: FromDS flag is not set and the
148 * fourth address is added after the frame payload; it is
149 * assumed, that the receiving station knows how to handle this
150 * frame format */
151
152 if (use_wds == WDS_COMPLIANT_FRAME) {
153 fc |= IEEE80211_FCTL_FROMDS | IEEE80211_FCTL_TODS;
154 /* From&To DS: Addr1 = RA, Addr2 = TA, Addr3 = DA,
155 * Addr4 = SA */
156 skb_copy_from_linear_data_offset(skb, ETH_ALEN,
157 &hdr.addr4, ETH_ALEN);
158 hdr_len += ETH_ALEN;
159 } else {
160 /* bogus 4-addr format to workaround Prism2 station
161 * f/w bug */
162 fc |= IEEE80211_FCTL_TODS;
163 /* From DS: Addr1 = DA (used as RA),
164 * Addr2 = BSSID (used as TA), Addr3 = SA (used as DA),
165 */
166
167 /* SA from skb->data + ETH_ALEN will be added after
168 * frame payload; use hdr.addr4 as a temporary buffer
169 */
170 skb_copy_from_linear_data_offset(skb, ETH_ALEN,
171 &hdr.addr4, ETH_ALEN);
172 need_tailroom += ETH_ALEN;
173 }
174
175 /* send broadcast and multicast frames to broadcast RA, if
176 * configured; otherwise, use unicast RA of the WDS link */
177 if ((local->wds_type & HOSTAP_WDS_BROADCAST_RA) &&
178 is_multicast_ether_addr(skb->data))
179 eth_broadcast_addr(hdr.addr1);
180 else if (iface->type == HOSTAP_INTERFACE_WDS)
181 memcpy(&hdr.addr1, iface->u.wds.remote_addr,
182 ETH_ALEN);
183 else
184 memcpy(&hdr.addr1, local->bssid, ETH_ALEN);
185 memcpy(&hdr.addr2, dev->dev_addr, ETH_ALEN);
186 skb_copy_from_linear_data(skb, &hdr.addr3, ETH_ALEN);
187 } else if (local->iw_mode == IW_MODE_MASTER && !to_assoc_ap) {
188 fc |= IEEE80211_FCTL_FROMDS;
189 /* From DS: Addr1 = DA, Addr2 = BSSID, Addr3 = SA */
190 skb_copy_from_linear_data(skb, &hdr.addr1, ETH_ALEN);
191 memcpy(&hdr.addr2, dev->dev_addr, ETH_ALEN);
192 skb_copy_from_linear_data_offset(skb, ETH_ALEN, &hdr.addr3,
193 ETH_ALEN);
194 } else if (local->iw_mode == IW_MODE_INFRA || to_assoc_ap) {
195 fc |= IEEE80211_FCTL_TODS;
196 /* To DS: Addr1 = BSSID, Addr2 = SA, Addr3 = DA */
197 memcpy(&hdr.addr1, to_assoc_ap ?
198 local->assoc_ap_addr : local->bssid, ETH_ALEN);
199 skb_copy_from_linear_data_offset(skb, ETH_ALEN, &hdr.addr2,
200 ETH_ALEN);
201 skb_copy_from_linear_data(skb, &hdr.addr3, ETH_ALEN);
202 } else if (local->iw_mode == IW_MODE_ADHOC) {
203 /* not From/To DS: Addr1 = DA, Addr2 = SA, Addr3 = BSSID */
204 skb_copy_from_linear_data(skb, &hdr.addr1, ETH_ALEN);
205 skb_copy_from_linear_data_offset(skb, ETH_ALEN, &hdr.addr2,
206 ETH_ALEN);
207 memcpy(&hdr.addr3, local->bssid, ETH_ALEN);
208 }
209
210 hdr.frame_control = cpu_to_le16(fc);
211
212 skb_pull(skb, skip_header_bytes);
213 need_headroom = local->func->need_tx_headroom + hdr_len + encaps_len;
214 if (skb_tailroom(skb) < need_tailroom) {
215 skb = skb_unshare(skb, GFP_ATOMIC);
216 if (skb == NULL) {
217 iface->stats.tx_dropped++;
218 return NETDEV_TX_OK;
219 }
220 if (pskb_expand_head(skb, need_headroom, need_tailroom,
221 GFP_ATOMIC)) {
222 kfree_skb(skb);
223 iface->stats.tx_dropped++;
224 return NETDEV_TX_OK;
225 }
226 } else if (skb_headroom(skb) < need_headroom) {
227 struct sk_buff *tmp = skb;
228 skb = skb_realloc_headroom(skb, need_headroom);
229 kfree_skb(tmp);
230 if (skb == NULL) {
231 iface->stats.tx_dropped++;
232 return NETDEV_TX_OK;
233 }
234 } else {
235 skb = skb_unshare(skb, GFP_ATOMIC);
236 if (skb == NULL) {
237 iface->stats.tx_dropped++;
238 return NETDEV_TX_OK;
239 }
240 }
241
242 if (encaps_data)
243 memcpy(skb_push(skb, encaps_len), encaps_data, encaps_len);
244 memcpy(skb_push(skb, hdr_len), &hdr, hdr_len);
245 if (use_wds == WDS_OWN_FRAME) {
246 skb_put_data(skb, &hdr.addr4, ETH_ALEN);
247 }
248
249 iface->stats.tx_packets++;
250 iface->stats.tx_bytes += skb->len;
251
252 skb_reset_mac_header(skb);
253 meta = (struct hostap_skb_tx_data *) skb->cb;
254 memset(meta, 0, sizeof(*meta));
255 meta->magic = HOSTAP_SKB_TX_DATA_MAGIC;
256 if (use_wds)
257 meta->flags |= HOSTAP_TX_FLAGS_WDS;
258 meta->ethertype = ethertype;
259 meta->iface = iface;
260
261 /* Send IEEE 802.11 encapsulated frame using the master radio device */
262 skb->dev = local->dev;
263 dev_queue_xmit(skb);
264 return NETDEV_TX_OK;
265 }
266
267
268 /* hard_start_xmit function for hostapd wlan#ap interfaces */
hostap_mgmt_start_xmit(struct sk_buff * skb,struct net_device * dev)269 netdev_tx_t hostap_mgmt_start_xmit(struct sk_buff *skb,
270 struct net_device *dev)
271 {
272 struct hostap_interface *iface;
273 local_info_t *local;
274 struct hostap_skb_tx_data *meta;
275 struct ieee80211_hdr *hdr;
276 u16 fc;
277
278 iface = netdev_priv(dev);
279 local = iface->local;
280
281 if (skb->len < 10) {
282 printk(KERN_DEBUG "%s: hostap_mgmt_start_xmit: short skb "
283 "(len=%d)\n", dev->name, skb->len);
284 kfree_skb(skb);
285 return NETDEV_TX_OK;
286 }
287
288 iface->stats.tx_packets++;
289 iface->stats.tx_bytes += skb->len;
290
291 meta = (struct hostap_skb_tx_data *) skb->cb;
292 memset(meta, 0, sizeof(*meta));
293 meta->magic = HOSTAP_SKB_TX_DATA_MAGIC;
294 meta->iface = iface;
295
296 if (skb->len >= IEEE80211_DATA_HDR3_LEN + sizeof(rfc1042_header) + 2) {
297 hdr = (struct ieee80211_hdr *) skb->data;
298 fc = le16_to_cpu(hdr->frame_control);
299 if (ieee80211_is_data(hdr->frame_control) &&
300 (fc & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_DATA) {
301 u8 *pos = &skb->data[IEEE80211_DATA_HDR3_LEN +
302 sizeof(rfc1042_header)];
303 meta->ethertype = (pos[0] << 8) | pos[1];
304 }
305 }
306
307 /* Send IEEE 802.11 encapsulated frame using the master radio device */
308 skb->dev = local->dev;
309 dev_queue_xmit(skb);
310 return NETDEV_TX_OK;
311 }
312
313
314 /* Called only from software IRQ */
hostap_tx_encrypt(struct sk_buff * skb,struct lib80211_crypt_data * crypt)315 static struct sk_buff * hostap_tx_encrypt(struct sk_buff *skb,
316 struct lib80211_crypt_data *crypt)
317 {
318 struct hostap_interface *iface;
319 local_info_t *local;
320 struct ieee80211_hdr *hdr;
321 int prefix_len, postfix_len, hdr_len, res;
322
323 iface = netdev_priv(skb->dev);
324 local = iface->local;
325
326 if (skb->len < IEEE80211_DATA_HDR3_LEN) {
327 kfree_skb(skb);
328 return NULL;
329 }
330
331 if (local->tkip_countermeasures &&
332 strcmp(crypt->ops->name, "TKIP") == 0) {
333 hdr = (struct ieee80211_hdr *) skb->data;
334 if (net_ratelimit()) {
335 printk(KERN_DEBUG "%s: TKIP countermeasures: dropped "
336 "TX packet to %pM\n",
337 local->dev->name, hdr->addr1);
338 }
339 kfree_skb(skb);
340 return NULL;
341 }
342
343 skb = skb_unshare(skb, GFP_ATOMIC);
344 if (skb == NULL)
345 return NULL;
346
347 prefix_len = crypt->ops->extra_mpdu_prefix_len +
348 crypt->ops->extra_msdu_prefix_len;
349 postfix_len = crypt->ops->extra_mpdu_postfix_len +
350 crypt->ops->extra_msdu_postfix_len;
351 if ((skb_headroom(skb) < prefix_len ||
352 skb_tailroom(skb) < postfix_len) &&
353 pskb_expand_head(skb, prefix_len, postfix_len, GFP_ATOMIC)) {
354 kfree_skb(skb);
355 return NULL;
356 }
357
358 hdr = (struct ieee80211_hdr *) skb->data;
359 hdr_len = hostap_80211_get_hdrlen(hdr->frame_control);
360
361 /* Host-based IEEE 802.11 fragmentation for TX is not yet supported, so
362 * call both MSDU and MPDU encryption functions from here. */
363 atomic_inc(&crypt->refcnt);
364 res = 0;
365 if (crypt->ops->encrypt_msdu)
366 res = crypt->ops->encrypt_msdu(skb, hdr_len, crypt->priv);
367 if (res == 0 && crypt->ops->encrypt_mpdu)
368 res = crypt->ops->encrypt_mpdu(skb, hdr_len, crypt->priv);
369 atomic_dec(&crypt->refcnt);
370 if (res < 0) {
371 kfree_skb(skb);
372 return NULL;
373 }
374
375 return skb;
376 }
377
378
379 /* hard_start_xmit function for master radio interface wifi#.
380 * AP processing (TX rate control, power save buffering, etc.).
381 * Use hardware TX function to send the frame. */
hostap_master_start_xmit(struct sk_buff * skb,struct net_device * dev)382 netdev_tx_t hostap_master_start_xmit(struct sk_buff *skb,
383 struct net_device *dev)
384 {
385 struct hostap_interface *iface;
386 local_info_t *local;
387 netdev_tx_t ret = NETDEV_TX_BUSY;
388 u16 fc;
389 struct hostap_tx_data tx;
390 ap_tx_ret tx_ret;
391 struct hostap_skb_tx_data *meta;
392 int no_encrypt = 0;
393 struct ieee80211_hdr *hdr;
394
395 iface = netdev_priv(dev);
396 local = iface->local;
397
398 tx.skb = skb;
399 tx.sta_ptr = NULL;
400
401 meta = (struct hostap_skb_tx_data *) skb->cb;
402 if (meta->magic != HOSTAP_SKB_TX_DATA_MAGIC) {
403 printk(KERN_DEBUG "%s: invalid skb->cb magic (0x%08x, "
404 "expected 0x%08x)\n",
405 dev->name, meta->magic, HOSTAP_SKB_TX_DATA_MAGIC);
406 ret = NETDEV_TX_OK;
407 iface->stats.tx_dropped++;
408 goto fail;
409 }
410
411 if (local->host_encrypt) {
412 /* Set crypt to default algorithm and key; will be replaced in
413 * AP code if STA has own alg/key */
414 tx.crypt = local->crypt_info.crypt[local->crypt_info.tx_keyidx];
415 tx.host_encrypt = 1;
416 } else {
417 tx.crypt = NULL;
418 tx.host_encrypt = 0;
419 }
420
421 if (skb->len < 24) {
422 printk(KERN_DEBUG "%s: hostap_master_start_xmit: short skb "
423 "(len=%d)\n", dev->name, skb->len);
424 ret = NETDEV_TX_OK;
425 iface->stats.tx_dropped++;
426 goto fail;
427 }
428
429 /* FIX (?):
430 * Wi-Fi 802.11b test plan suggests that AP should ignore power save
431 * bit in authentication and (re)association frames and assume tha
432 * STA remains awake for the response. */
433 tx_ret = hostap_handle_sta_tx(local, &tx);
434 skb = tx.skb;
435 meta = (struct hostap_skb_tx_data *) skb->cb;
436 hdr = (struct ieee80211_hdr *) skb->data;
437 fc = le16_to_cpu(hdr->frame_control);
438 switch (tx_ret) {
439 case AP_TX_CONTINUE:
440 break;
441 case AP_TX_CONTINUE_NOT_AUTHORIZED:
442 if (local->ieee_802_1x &&
443 ieee80211_is_data(hdr->frame_control) &&
444 meta->ethertype != ETH_P_PAE &&
445 !(meta->flags & HOSTAP_TX_FLAGS_WDS)) {
446 printk(KERN_DEBUG "%s: dropped frame to unauthorized "
447 "port (IEEE 802.1X): ethertype=0x%04x\n",
448 dev->name, meta->ethertype);
449 hostap_dump_tx_80211(dev->name, skb);
450
451 ret = NETDEV_TX_OK; /* drop packet */
452 iface->stats.tx_dropped++;
453 goto fail;
454 }
455 break;
456 case AP_TX_DROP:
457 ret = NETDEV_TX_OK; /* drop packet */
458 iface->stats.tx_dropped++;
459 goto fail;
460 case AP_TX_RETRY:
461 goto fail;
462 case AP_TX_BUFFERED:
463 /* do not free skb here, it will be freed when the
464 * buffered frame is sent/timed out */
465 ret = NETDEV_TX_OK;
466 goto tx_exit;
467 }
468
469 /* Request TX callback if protocol version is 2 in 802.11 header;
470 * this version 2 is a special case used between hostapd and kernel
471 * driver */
472 if (((fc & IEEE80211_FCTL_VERS) == BIT(1)) &&
473 local->ap && local->ap->tx_callback_idx && meta->tx_cb_idx == 0) {
474 meta->tx_cb_idx = local->ap->tx_callback_idx;
475
476 /* remove special version from the frame header */
477 fc &= ~IEEE80211_FCTL_VERS;
478 hdr->frame_control = cpu_to_le16(fc);
479 }
480
481 if (!ieee80211_is_data(hdr->frame_control)) {
482 no_encrypt = 1;
483 tx.crypt = NULL;
484 }
485
486 if (local->ieee_802_1x && meta->ethertype == ETH_P_PAE && tx.crypt &&
487 !(fc & IEEE80211_FCTL_PROTECTED)) {
488 no_encrypt = 1;
489 PDEBUG(DEBUG_EXTRA2, "%s: TX: IEEE 802.1X - passing "
490 "unencrypted EAPOL frame\n", dev->name);
491 tx.crypt = NULL; /* no encryption for IEEE 802.1X frames */
492 }
493
494 if (tx.crypt && (!tx.crypt->ops || !tx.crypt->ops->encrypt_mpdu))
495 tx.crypt = NULL;
496 else if ((tx.crypt ||
497 local->crypt_info.crypt[local->crypt_info.tx_keyidx]) &&
498 !no_encrypt) {
499 /* Add ISWEP flag both for firmware and host based encryption
500 */
501 fc |= IEEE80211_FCTL_PROTECTED;
502 hdr->frame_control = cpu_to_le16(fc);
503 } else if (local->drop_unencrypted &&
504 ieee80211_is_data(hdr->frame_control) &&
505 meta->ethertype != ETH_P_PAE) {
506 if (net_ratelimit()) {
507 printk(KERN_DEBUG "%s: dropped unencrypted TX data "
508 "frame (drop_unencrypted=1)\n", dev->name);
509 }
510 iface->stats.tx_dropped++;
511 ret = NETDEV_TX_OK;
512 goto fail;
513 }
514
515 if (tx.crypt) {
516 skb = hostap_tx_encrypt(skb, tx.crypt);
517 if (skb == NULL) {
518 printk(KERN_DEBUG "%s: TX - encryption failed\n",
519 dev->name);
520 ret = NETDEV_TX_OK;
521 goto fail;
522 }
523 meta = (struct hostap_skb_tx_data *) skb->cb;
524 if (meta->magic != HOSTAP_SKB_TX_DATA_MAGIC) {
525 printk(KERN_DEBUG "%s: invalid skb->cb magic (0x%08x, "
526 "expected 0x%08x) after hostap_tx_encrypt\n",
527 dev->name, meta->magic,
528 HOSTAP_SKB_TX_DATA_MAGIC);
529 ret = NETDEV_TX_OK;
530 iface->stats.tx_dropped++;
531 goto fail;
532 }
533 }
534
535 if (local->func->tx == NULL || local->func->tx(skb, dev)) {
536 ret = NETDEV_TX_OK;
537 iface->stats.tx_dropped++;
538 } else {
539 ret = NETDEV_TX_OK;
540 iface->stats.tx_packets++;
541 iface->stats.tx_bytes += skb->len;
542 }
543
544 fail:
545 if (ret == NETDEV_TX_OK && skb)
546 dev_kfree_skb(skb);
547 tx_exit:
548 if (tx.sta_ptr)
549 hostap_handle_sta_release(tx.sta_ptr);
550 return ret;
551 }
552
553
554 EXPORT_SYMBOL(hostap_master_start_xmit);
555