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12#include <net/cfg80211.h>
13#include <net/rtnetlink.h>
14#include <linux/etherdevice.h>
15#include <linux/module.h>
16
17static struct wiphy *common_wiphy;
18
19struct virt_wifi_wiphy_priv {
20 struct delayed_work scan_result;
21 struct cfg80211_scan_request *scan_request;
22 bool being_deleted;
23};
24
25static struct ieee80211_channel channel_2ghz = {
26 .band = NL80211_BAND_2GHZ,
27 .center_freq = 2432,
28 .hw_value = 2432,
29 .max_power = 20,
30};
31
32static struct ieee80211_rate bitrates_2ghz[] = {
33 { .bitrate = 10 },
34 { .bitrate = 20 },
35 { .bitrate = 55 },
36 { .bitrate = 110 },
37 { .bitrate = 60 },
38 { .bitrate = 120 },
39 { .bitrate = 240 },
40};
41
42static struct ieee80211_supported_band band_2ghz = {
43 .channels = &channel_2ghz,
44 .bitrates = bitrates_2ghz,
45 .band = NL80211_BAND_2GHZ,
46 .n_channels = 1,
47 .n_bitrates = ARRAY_SIZE(bitrates_2ghz),
48 .ht_cap = {
49 .ht_supported = true,
50 .cap = IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
51 IEEE80211_HT_CAP_GRN_FLD |
52 IEEE80211_HT_CAP_SGI_20 |
53 IEEE80211_HT_CAP_SGI_40 |
54 IEEE80211_HT_CAP_DSSSCCK40,
55 .ampdu_factor = 0x3,
56 .ampdu_density = 0x6,
57 .mcs = {
58 .rx_mask = {0xff, 0xff},
59 .tx_params = IEEE80211_HT_MCS_TX_DEFINED,
60 },
61 },
62};
63
64static struct ieee80211_channel channel_5ghz = {
65 .band = NL80211_BAND_5GHZ,
66 .center_freq = 5240,
67 .hw_value = 5240,
68 .max_power = 20,
69};
70
71static struct ieee80211_rate bitrates_5ghz[] = {
72 { .bitrate = 60 },
73 { .bitrate = 120 },
74 { .bitrate = 240 },
75};
76
77#define RX_MCS_MAP (IEEE80211_VHT_MCS_SUPPORT_0_9 << 0 | \
78 IEEE80211_VHT_MCS_SUPPORT_0_9 << 2 | \
79 IEEE80211_VHT_MCS_SUPPORT_0_9 << 4 | \
80 IEEE80211_VHT_MCS_SUPPORT_0_9 << 6 | \
81 IEEE80211_VHT_MCS_SUPPORT_0_9 << 8 | \
82 IEEE80211_VHT_MCS_SUPPORT_0_9 << 10 | \
83 IEEE80211_VHT_MCS_SUPPORT_0_9 << 12 | \
84 IEEE80211_VHT_MCS_SUPPORT_0_9 << 14)
85
86#define TX_MCS_MAP (IEEE80211_VHT_MCS_SUPPORT_0_9 << 0 | \
87 IEEE80211_VHT_MCS_SUPPORT_0_9 << 2 | \
88 IEEE80211_VHT_MCS_SUPPORT_0_9 << 4 | \
89 IEEE80211_VHT_MCS_SUPPORT_0_9 << 6 | \
90 IEEE80211_VHT_MCS_SUPPORT_0_9 << 8 | \
91 IEEE80211_VHT_MCS_SUPPORT_0_9 << 10 | \
92 IEEE80211_VHT_MCS_SUPPORT_0_9 << 12 | \
93 IEEE80211_VHT_MCS_SUPPORT_0_9 << 14)
94
95static struct ieee80211_supported_band band_5ghz = {
96 .channels = &channel_5ghz,
97 .bitrates = bitrates_5ghz,
98 .band = NL80211_BAND_5GHZ,
99 .n_channels = 1,
100 .n_bitrates = ARRAY_SIZE(bitrates_5ghz),
101 .ht_cap = {
102 .ht_supported = true,
103 .cap = IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
104 IEEE80211_HT_CAP_GRN_FLD |
105 IEEE80211_HT_CAP_SGI_20 |
106 IEEE80211_HT_CAP_SGI_40 |
107 IEEE80211_HT_CAP_DSSSCCK40,
108 .ampdu_factor = 0x3,
109 .ampdu_density = 0x6,
110 .mcs = {
111 .rx_mask = {0xff, 0xff},
112 .tx_params = IEEE80211_HT_MCS_TX_DEFINED,
113 },
114 },
115 .vht_cap = {
116 .vht_supported = true,
117 .cap = IEEE80211_VHT_CAP_MAX_MPDU_LENGTH_11454 |
118 IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ |
119 IEEE80211_VHT_CAP_RXLDPC |
120 IEEE80211_VHT_CAP_SHORT_GI_80 |
121 IEEE80211_VHT_CAP_SHORT_GI_160 |
122 IEEE80211_VHT_CAP_TXSTBC |
123 IEEE80211_VHT_CAP_RXSTBC_1 |
124 IEEE80211_VHT_CAP_RXSTBC_2 |
125 IEEE80211_VHT_CAP_RXSTBC_3 |
126 IEEE80211_VHT_CAP_RXSTBC_4 |
127 IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK,
128 .vht_mcs = {
129 .rx_mcs_map = cpu_to_le16(RX_MCS_MAP),
130 .tx_mcs_map = cpu_to_le16(TX_MCS_MAP),
131 }
132 },
133};
134
135
136static u8 fake_router_bssid[ETH_ALEN] __ro_after_init = {};
137
138
139static int virt_wifi_scan(struct wiphy *wiphy,
140 struct cfg80211_scan_request *request)
141{
142 struct virt_wifi_wiphy_priv *priv = wiphy_priv(wiphy);
143
144 wiphy_debug(wiphy, "scan\n");
145
146 if (priv->scan_request || priv->being_deleted)
147 return -EBUSY;
148
149 priv->scan_request = request;
150 schedule_delayed_work(&priv->scan_result, HZ * 2);
151
152 return 0;
153}
154
155
156static void virt_wifi_scan_result(struct work_struct *work)
157{
158 struct {
159 u8 tag;
160 u8 len;
161 u8 ssid[8];
162 } __packed ssid = {
163 .tag = WLAN_EID_SSID, .len = 8, .ssid = "VirtWifi",
164 };
165 struct cfg80211_bss *informed_bss;
166 struct virt_wifi_wiphy_priv *priv =
167 container_of(work, struct virt_wifi_wiphy_priv,
168 scan_result.work);
169 struct wiphy *wiphy = priv_to_wiphy(priv);
170 struct cfg80211_scan_info scan_info = { .aborted = false };
171
172 informed_bss = cfg80211_inform_bss(wiphy, &channel_5ghz,
173 CFG80211_BSS_FTYPE_PRESP,
174 fake_router_bssid,
175 ktime_get_boottime_ns(),
176 WLAN_CAPABILITY_ESS, 0,
177 (void *)&ssid, sizeof(ssid),
178 DBM_TO_MBM(-50), GFP_KERNEL);
179 cfg80211_put_bss(wiphy, informed_bss);
180
181
182 cfg80211_scan_done(priv->scan_request, &scan_info);
183 priv->scan_request = NULL;
184}
185
186
187static void virt_wifi_cancel_scan(struct wiphy *wiphy)
188{
189 struct virt_wifi_wiphy_priv *priv = wiphy_priv(wiphy);
190
191 cancel_delayed_work_sync(&priv->scan_result);
192
193 if (priv->scan_request) {
194 struct cfg80211_scan_info scan_info = { .aborted = true };
195
196 cfg80211_scan_done(priv->scan_request, &scan_info);
197 priv->scan_request = NULL;
198 }
199}
200
201struct virt_wifi_netdev_priv {
202 struct delayed_work connect;
203 struct net_device *lowerdev;
204 struct net_device *upperdev;
205 u32 tx_packets;
206 u32 tx_failed;
207 u8 connect_requested_bss[ETH_ALEN];
208 bool is_up;
209 bool is_connected;
210 bool being_deleted;
211};
212
213
214static int virt_wifi_connect(struct wiphy *wiphy, struct net_device *netdev,
215 struct cfg80211_connect_params *sme)
216{
217 struct virt_wifi_netdev_priv *priv = netdev_priv(netdev);
218 bool could_schedule;
219
220 if (priv->being_deleted || !priv->is_up)
221 return -EBUSY;
222
223 could_schedule = schedule_delayed_work(&priv->connect, HZ * 2);
224 if (!could_schedule)
225 return -EBUSY;
226
227 if (sme->bssid)
228 ether_addr_copy(priv->connect_requested_bss, sme->bssid);
229 else
230 eth_zero_addr(priv->connect_requested_bss);
231
232 wiphy_debug(wiphy, "connect\n");
233
234 return 0;
235}
236
237
238static void virt_wifi_connect_complete(struct work_struct *work)
239{
240 struct virt_wifi_netdev_priv *priv =
241 container_of(work, struct virt_wifi_netdev_priv, connect.work);
242 u8 *requested_bss = priv->connect_requested_bss;
243 bool has_addr = !is_zero_ether_addr(requested_bss);
244 bool right_addr = ether_addr_equal(requested_bss, fake_router_bssid);
245 u16 status = WLAN_STATUS_SUCCESS;
246
247 if (!priv->is_up || (has_addr && !right_addr))
248 status = WLAN_STATUS_UNSPECIFIED_FAILURE;
249 else
250 priv->is_connected = true;
251
252
253 cfg80211_connect_result(priv->upperdev, requested_bss, NULL, 0, NULL, 0,
254 status, GFP_KERNEL);
255 netif_carrier_on(priv->upperdev);
256}
257
258
259static void virt_wifi_cancel_connect(struct net_device *netdev)
260{
261 struct virt_wifi_netdev_priv *priv = netdev_priv(netdev);
262
263
264 if (cancel_delayed_work_sync(&priv->connect)) {
265
266 cfg80211_connect_result(priv->upperdev,
267 priv->connect_requested_bss, NULL, 0,
268 NULL, 0,
269 WLAN_STATUS_UNSPECIFIED_FAILURE,
270 GFP_KERNEL);
271 }
272}
273
274
275static int virt_wifi_disconnect(struct wiphy *wiphy, struct net_device *netdev,
276 u16 reason_code)
277{
278 struct virt_wifi_netdev_priv *priv = netdev_priv(netdev);
279
280 if (priv->being_deleted)
281 return -EBUSY;
282
283 wiphy_debug(wiphy, "disconnect\n");
284 virt_wifi_cancel_connect(netdev);
285
286 cfg80211_disconnected(netdev, reason_code, NULL, 0, true, GFP_KERNEL);
287 priv->is_connected = false;
288 netif_carrier_off(netdev);
289
290 return 0;
291}
292
293
294static int virt_wifi_get_station(struct wiphy *wiphy, struct net_device *dev,
295 const u8 *mac, struct station_info *sinfo)
296{
297 struct virt_wifi_netdev_priv *priv = netdev_priv(dev);
298
299 wiphy_debug(wiphy, "get_station\n");
300
301 if (!priv->is_connected || !ether_addr_equal(mac, fake_router_bssid))
302 return -ENOENT;
303
304 sinfo->filled = BIT_ULL(NL80211_STA_INFO_TX_PACKETS) |
305 BIT_ULL(NL80211_STA_INFO_TX_FAILED) |
306 BIT_ULL(NL80211_STA_INFO_SIGNAL) |
307 BIT_ULL(NL80211_STA_INFO_TX_BITRATE);
308 sinfo->tx_packets = priv->tx_packets;
309 sinfo->tx_failed = priv->tx_failed;
310
311 sinfo->signal = -50;
312 sinfo->txrate = (struct rate_info) {
313 .legacy = 10,
314 };
315 return 0;
316}
317
318
319static int virt_wifi_dump_station(struct wiphy *wiphy, struct net_device *dev,
320 int idx, u8 *mac, struct station_info *sinfo)
321{
322 struct virt_wifi_netdev_priv *priv = netdev_priv(dev);
323
324 wiphy_debug(wiphy, "dump_station\n");
325
326 if (idx != 0 || !priv->is_connected)
327 return -ENOENT;
328
329 ether_addr_copy(mac, fake_router_bssid);
330 return virt_wifi_get_station(wiphy, dev, fake_router_bssid, sinfo);
331}
332
333static const struct cfg80211_ops virt_wifi_cfg80211_ops = {
334 .scan = virt_wifi_scan,
335
336 .connect = virt_wifi_connect,
337 .disconnect = virt_wifi_disconnect,
338
339 .get_station = virt_wifi_get_station,
340 .dump_station = virt_wifi_dump_station,
341};
342
343
344static struct wiphy *virt_wifi_make_wiphy(void)
345{
346 struct wiphy *wiphy;
347 struct virt_wifi_wiphy_priv *priv;
348 int err;
349
350 wiphy = wiphy_new(&virt_wifi_cfg80211_ops, sizeof(*priv));
351
352 if (!wiphy)
353 return NULL;
354
355 wiphy->max_scan_ssids = 4;
356 wiphy->max_scan_ie_len = 1000;
357 wiphy->signal_type = CFG80211_SIGNAL_TYPE_MBM;
358
359 wiphy->bands[NL80211_BAND_2GHZ] = &band_2ghz;
360 wiphy->bands[NL80211_BAND_5GHZ] = &band_5ghz;
361 wiphy->bands[NL80211_BAND_60GHZ] = NULL;
362
363 wiphy->interface_modes = BIT(NL80211_IFTYPE_STATION);
364
365 priv = wiphy_priv(wiphy);
366 priv->being_deleted = false;
367 priv->scan_request = NULL;
368 INIT_DELAYED_WORK(&priv->scan_result, virt_wifi_scan_result);
369
370 err = wiphy_register(wiphy);
371 if (err < 0) {
372 wiphy_free(wiphy);
373 return NULL;
374 }
375
376 return wiphy;
377}
378
379
380static void virt_wifi_destroy_wiphy(struct wiphy *wiphy)
381{
382 struct virt_wifi_wiphy_priv *priv;
383
384 WARN(!wiphy, "%s called with null wiphy", __func__);
385 if (!wiphy)
386 return;
387
388 priv = wiphy_priv(wiphy);
389 priv->being_deleted = true;
390 virt_wifi_cancel_scan(wiphy);
391
392 if (wiphy->registered)
393 wiphy_unregister(wiphy);
394 wiphy_free(wiphy);
395}
396
397
398static netdev_tx_t virt_wifi_start_xmit(struct sk_buff *skb,
399 struct net_device *dev)
400{
401 struct virt_wifi_netdev_priv *priv = netdev_priv(dev);
402
403 priv->tx_packets++;
404 if (!priv->is_connected) {
405 priv->tx_failed++;
406 return NET_XMIT_DROP;
407 }
408
409 skb->dev = priv->lowerdev;
410 return dev_queue_xmit(skb);
411}
412
413
414static int virt_wifi_net_device_open(struct net_device *dev)
415{
416 struct virt_wifi_netdev_priv *priv = netdev_priv(dev);
417
418 priv->is_up = true;
419 return 0;
420}
421
422
423static int virt_wifi_net_device_stop(struct net_device *dev)
424{
425 struct virt_wifi_netdev_priv *n_priv = netdev_priv(dev);
426
427 n_priv->is_up = false;
428
429 if (!dev->ieee80211_ptr)
430 return 0;
431
432 virt_wifi_cancel_scan(dev->ieee80211_ptr->wiphy);
433 virt_wifi_cancel_connect(dev);
434 netif_carrier_off(dev);
435
436 return 0;
437}
438
439static int virt_wifi_net_device_get_iflink(const struct net_device *dev)
440{
441 struct virt_wifi_netdev_priv *priv = netdev_priv(dev);
442
443 return priv->lowerdev->ifindex;
444}
445
446static const struct net_device_ops virt_wifi_ops = {
447 .ndo_start_xmit = virt_wifi_start_xmit,
448 .ndo_open = virt_wifi_net_device_open,
449 .ndo_stop = virt_wifi_net_device_stop,
450 .ndo_get_iflink = virt_wifi_net_device_get_iflink,
451};
452
453
454static void virt_wifi_net_device_destructor(struct net_device *dev)
455{
456
457
458
459 kfree(dev->ieee80211_ptr);
460 dev->ieee80211_ptr = NULL;
461}
462
463
464static void virt_wifi_setup(struct net_device *dev)
465{
466 ether_setup(dev);
467 dev->netdev_ops = &virt_wifi_ops;
468 dev->needs_free_netdev = true;
469}
470
471
472static rx_handler_result_t virt_wifi_rx_handler(struct sk_buff **pskb)
473{
474 struct sk_buff *skb = *pskb;
475 struct virt_wifi_netdev_priv *priv =
476 rcu_dereference(skb->dev->rx_handler_data);
477
478 if (!priv->is_connected)
479 return RX_HANDLER_PASS;
480
481
482 skb = skb_share_check(skb, GFP_ATOMIC);
483 if (!skb) {
484 dev_err(&priv->upperdev->dev, "can't skb_share_check\n");
485 return RX_HANDLER_CONSUMED;
486 }
487
488 *pskb = skb;
489 skb->dev = priv->upperdev;
490 skb->pkt_type = PACKET_HOST;
491 return RX_HANDLER_ANOTHER;
492}
493
494
495static int virt_wifi_newlink(struct net *src_net, struct net_device *dev,
496 struct nlattr *tb[], struct nlattr *data[],
497 struct netlink_ext_ack *extack)
498{
499 struct virt_wifi_netdev_priv *priv = netdev_priv(dev);
500 int err;
501
502 if (!tb[IFLA_LINK])
503 return -EINVAL;
504
505 netif_carrier_off(dev);
506
507 priv->upperdev = dev;
508 priv->lowerdev = __dev_get_by_index(src_net,
509 nla_get_u32(tb[IFLA_LINK]));
510
511 if (!priv->lowerdev)
512 return -ENODEV;
513 if (!tb[IFLA_MTU])
514 dev->mtu = priv->lowerdev->mtu;
515 else if (dev->mtu > priv->lowerdev->mtu)
516 return -EINVAL;
517
518 err = netdev_rx_handler_register(priv->lowerdev, virt_wifi_rx_handler,
519 priv);
520 if (err) {
521 dev_err(&priv->lowerdev->dev,
522 "can't netdev_rx_handler_register: %d\n", err);
523 return err;
524 }
525
526 eth_hw_addr_inherit(dev, priv->lowerdev);
527 netif_stacked_transfer_operstate(priv->lowerdev, dev);
528
529 SET_NETDEV_DEV(dev, &priv->lowerdev->dev);
530 dev->ieee80211_ptr = kzalloc(sizeof(*dev->ieee80211_ptr), GFP_KERNEL);
531
532 if (!dev->ieee80211_ptr) {
533 err = -ENOMEM;
534 goto remove_handler;
535 }
536
537 dev->ieee80211_ptr->iftype = NL80211_IFTYPE_STATION;
538 dev->ieee80211_ptr->wiphy = common_wiphy;
539
540 err = register_netdevice(dev);
541 if (err) {
542 dev_err(&priv->lowerdev->dev, "can't register_netdevice: %d\n",
543 err);
544 goto free_wireless_dev;
545 }
546
547 err = netdev_upper_dev_link(priv->lowerdev, dev, extack);
548 if (err) {
549 dev_err(&priv->lowerdev->dev, "can't netdev_upper_dev_link: %d\n",
550 err);
551 goto unregister_netdev;
552 }
553
554 dev->priv_destructor = virt_wifi_net_device_destructor;
555 priv->being_deleted = false;
556 priv->is_connected = false;
557 priv->is_up = false;
558 INIT_DELAYED_WORK(&priv->connect, virt_wifi_connect_complete);
559 __module_get(THIS_MODULE);
560
561 return 0;
562unregister_netdev:
563 unregister_netdevice(dev);
564free_wireless_dev:
565 kfree(dev->ieee80211_ptr);
566 dev->ieee80211_ptr = NULL;
567remove_handler:
568 netdev_rx_handler_unregister(priv->lowerdev);
569
570 return err;
571}
572
573
574static void virt_wifi_dellink(struct net_device *dev,
575 struct list_head *head)
576{
577 struct virt_wifi_netdev_priv *priv = netdev_priv(dev);
578
579 if (dev->ieee80211_ptr)
580 virt_wifi_cancel_scan(dev->ieee80211_ptr->wiphy);
581
582 priv->being_deleted = true;
583 virt_wifi_cancel_connect(dev);
584 netif_carrier_off(dev);
585
586 netdev_rx_handler_unregister(priv->lowerdev);
587 netdev_upper_dev_unlink(priv->lowerdev, dev);
588
589 unregister_netdevice_queue(dev, head);
590 module_put(THIS_MODULE);
591
592
593}
594
595static struct rtnl_link_ops virt_wifi_link_ops = {
596 .kind = "virt_wifi",
597 .setup = virt_wifi_setup,
598 .newlink = virt_wifi_newlink,
599 .dellink = virt_wifi_dellink,
600 .priv_size = sizeof(struct virt_wifi_netdev_priv),
601};
602
603static bool netif_is_virt_wifi_dev(const struct net_device *dev)
604{
605 return rcu_access_pointer(dev->rx_handler) == virt_wifi_rx_handler;
606}
607
608static int virt_wifi_event(struct notifier_block *this, unsigned long event,
609 void *ptr)
610{
611 struct net_device *lower_dev = netdev_notifier_info_to_dev(ptr);
612 struct virt_wifi_netdev_priv *priv;
613 struct net_device *upper_dev;
614 LIST_HEAD(list_kill);
615
616 if (!netif_is_virt_wifi_dev(lower_dev))
617 return NOTIFY_DONE;
618
619 switch (event) {
620 case NETDEV_UNREGISTER:
621 priv = rtnl_dereference(lower_dev->rx_handler_data);
622 if (!priv)
623 return NOTIFY_DONE;
624
625 upper_dev = priv->upperdev;
626
627 upper_dev->rtnl_link_ops->dellink(upper_dev, &list_kill);
628 unregister_netdevice_many(&list_kill);
629 break;
630 }
631
632 return NOTIFY_DONE;
633}
634
635static struct notifier_block virt_wifi_notifier = {
636 .notifier_call = virt_wifi_event,
637};
638
639
640static int __init virt_wifi_init_module(void)
641{
642 int err;
643
644
645 eth_random_addr(fake_router_bssid);
646
647 err = register_netdevice_notifier(&virt_wifi_notifier);
648 if (err)
649 return err;
650
651 err = -ENOMEM;
652 common_wiphy = virt_wifi_make_wiphy();
653 if (!common_wiphy)
654 goto notifier;
655
656 err = rtnl_link_register(&virt_wifi_link_ops);
657 if (err)
658 goto destroy_wiphy;
659
660 return 0;
661
662destroy_wiphy:
663 virt_wifi_destroy_wiphy(common_wiphy);
664notifier:
665 unregister_netdevice_notifier(&virt_wifi_notifier);
666 return err;
667}
668
669
670static void __exit virt_wifi_cleanup_module(void)
671{
672
673 rtnl_link_unregister(&virt_wifi_link_ops);
674 virt_wifi_destroy_wiphy(common_wiphy);
675 unregister_netdevice_notifier(&virt_wifi_notifier);
676}
677
678module_init(virt_wifi_init_module);
679module_exit(virt_wifi_cleanup_module);
680
681MODULE_LICENSE("GPL v2");
682MODULE_AUTHOR("Cody Schuffelen <schuffelen@google.com>");
683MODULE_DESCRIPTION("Driver for a wireless wrapper of ethernet devices");
684MODULE_ALIAS_RTNL_LINK("virt_wifi");
685
