1 // SPDX-License-Identifier: GPL-2.0
2 /* drivers/net/wireless/virt_wifi.c
3 *
4 * A fake implementation of cfg80211_ops that can be tacked on to an ethernet
5 * net_device to make it appear as a wireless connection.
6 *
7 * Copyright (C) 2018 Google, Inc.
8 *
9 * Author: schuffelen@google.com
10 */
11
12 #include <net/cfg80211.h>
13 #include <net/rtnetlink.h>
14 #include <linux/etherdevice.h>
15 #include <linux/module.h>
16
17 static struct wiphy *common_wiphy;
18
19 struct virt_wifi_wiphy_priv {
20 struct delayed_work scan_result;
21 struct cfg80211_scan_request *scan_request;
22 bool being_deleted;
23 };
24
25 static struct ieee80211_channel channel_2ghz = {
26 .band = NL80211_BAND_2GHZ,
27 .center_freq = 2432,
28 .hw_value = 2432,
29 .max_power = 20,
30 };
31
32 static 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
42 static 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
64 static struct ieee80211_channel channel_5ghz = {
65 .band = NL80211_BAND_5GHZ,
66 .center_freq = 5240,
67 .hw_value = 5240,
68 .max_power = 20,
69 };
70
71 static 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
95 static 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 /* Assigned at module init. Guaranteed locally-administered and unicast. */
136 static u8 fake_router_bssid[ETH_ALEN] __ro_after_init = {};
137
138 /* Called with the rtnl lock held. */
virt_wifi_scan(struct wiphy * wiphy,struct cfg80211_scan_request * request)139 static 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 /* Acquires and releases the rdev BSS lock. */
virt_wifi_scan_result(struct work_struct * work)156 static 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 /* Schedules work which acquires and releases the rtnl lock. */
182 cfg80211_scan_done(priv->scan_request, &scan_info);
183 priv->scan_request = NULL;
184 }
185
186 /* May acquire and release the rdev BSS lock. */
virt_wifi_cancel_scan(struct wiphy * wiphy)187 static 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 /* Clean up dangling callbacks if necessary. */
193 if (priv->scan_request) {
194 struct cfg80211_scan_info scan_info = { .aborted = true };
195 /* Schedules work which acquires and releases the rtnl lock. */
196 cfg80211_scan_done(priv->scan_request, &scan_info);
197 priv->scan_request = NULL;
198 }
199 }
200
201 struct 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 /* Called with the rtnl lock held. */
virt_wifi_connect(struct wiphy * wiphy,struct net_device * netdev,struct cfg80211_connect_params * sme)214 static 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 /* Acquires and releases the rdev event lock. */
virt_wifi_connect_complete(struct work_struct * work)238 static 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 /* Schedules an event that acquires the rtnl lock. */
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 /* May acquire and release the rdev event lock. */
virt_wifi_cancel_connect(struct net_device * netdev)259 static void virt_wifi_cancel_connect(struct net_device *netdev)
260 {
261 struct virt_wifi_netdev_priv *priv = netdev_priv(netdev);
262
263 /* If there is work pending, clean up dangling callbacks. */
264 if (cancel_delayed_work_sync(&priv->connect)) {
265 /* Schedules an event that acquires the rtnl lock. */
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 /* Called with the rtnl lock held. Acquires the rdev event lock. */
virt_wifi_disconnect(struct wiphy * wiphy,struct net_device * netdev,u16 reason_code)275 static 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 /* Called with the rtnl lock held. */
virt_wifi_get_station(struct wiphy * wiphy,struct net_device * dev,const u8 * mac,struct station_info * sinfo)294 static 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 /* For CFG80211_SIGNAL_TYPE_MBM, value is expressed in _dBm_ */
311 sinfo->signal = -50;
312 sinfo->txrate = (struct rate_info) {
313 .legacy = 10, /* units are 100kbit/s */
314 };
315 return 0;
316 }
317
318 /* Called with the rtnl lock held. */
virt_wifi_dump_station(struct wiphy * wiphy,struct net_device * dev,int idx,u8 * mac,struct station_info * sinfo)319 static 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
333 static 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 /* Acquires and releases the rtnl lock. */
virt_wifi_make_wiphy(void)344 static 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 /* Acquires and releases the rtnl lock. */
virt_wifi_destroy_wiphy(struct wiphy * wiphy)380 static 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 /* Enters and exits a RCU-bh critical section. */
virt_wifi_start_xmit(struct sk_buff * skb,struct net_device * dev)398 static 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 /* Called with rtnl lock held. */
virt_wifi_net_device_open(struct net_device * dev)414 static 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 /* Called with rtnl lock held. */
virt_wifi_net_device_stop(struct net_device * dev)423 static 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
439 static const struct net_device_ops virt_wifi_ops = {
440 .ndo_start_xmit = virt_wifi_start_xmit,
441 .ndo_open = virt_wifi_net_device_open,
442 .ndo_stop = virt_wifi_net_device_stop,
443 };
444
445 /* Invoked as part of rtnl lock release. */
virt_wifi_net_device_destructor(struct net_device * dev)446 static void virt_wifi_net_device_destructor(struct net_device *dev)
447 {
448 /* Delayed past dellink to allow nl80211 to react to the device being
449 * deleted.
450 */
451 kfree(dev->ieee80211_ptr);
452 dev->ieee80211_ptr = NULL;
453 free_netdev(dev);
454 }
455
456 /* No lock interaction. */
virt_wifi_setup(struct net_device * dev)457 static void virt_wifi_setup(struct net_device *dev)
458 {
459 ether_setup(dev);
460 dev->netdev_ops = &virt_wifi_ops;
461 dev->priv_destructor = virt_wifi_net_device_destructor;
462 }
463
464 /* Called in a RCU read critical section from netif_receive_skb */
virt_wifi_rx_handler(struct sk_buff ** pskb)465 static rx_handler_result_t virt_wifi_rx_handler(struct sk_buff **pskb)
466 {
467 struct sk_buff *skb = *pskb;
468 struct virt_wifi_netdev_priv *priv =
469 rcu_dereference(skb->dev->rx_handler_data);
470
471 if (!priv->is_connected)
472 return RX_HANDLER_PASS;
473
474 /* GFP_ATOMIC because this is a packet interrupt handler. */
475 skb = skb_share_check(skb, GFP_ATOMIC);
476 if (!skb) {
477 dev_err(&priv->upperdev->dev, "can't skb_share_check\n");
478 return RX_HANDLER_CONSUMED;
479 }
480
481 *pskb = skb;
482 skb->dev = priv->upperdev;
483 skb->pkt_type = PACKET_HOST;
484 return RX_HANDLER_ANOTHER;
485 }
486
487 /* Called with rtnl lock held. */
virt_wifi_newlink(struct net * src_net,struct net_device * dev,struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)488 static int virt_wifi_newlink(struct net *src_net, struct net_device *dev,
489 struct nlattr *tb[], struct nlattr *data[],
490 struct netlink_ext_ack *extack)
491 {
492 struct virt_wifi_netdev_priv *priv = netdev_priv(dev);
493 int err;
494
495 if (!tb[IFLA_LINK])
496 return -EINVAL;
497
498 netif_carrier_off(dev);
499
500 priv->upperdev = dev;
501 priv->lowerdev = __dev_get_by_index(src_net,
502 nla_get_u32(tb[IFLA_LINK]));
503
504 if (!priv->lowerdev)
505 return -ENODEV;
506 if (!tb[IFLA_MTU])
507 dev->mtu = priv->lowerdev->mtu;
508 else if (dev->mtu > priv->lowerdev->mtu)
509 return -EINVAL;
510
511 err = netdev_rx_handler_register(priv->lowerdev, virt_wifi_rx_handler,
512 priv);
513 if (err) {
514 dev_err(&priv->lowerdev->dev,
515 "can't netdev_rx_handler_register: %d\n", err);
516 return err;
517 }
518
519 eth_hw_addr_inherit(dev, priv->lowerdev);
520 netif_stacked_transfer_operstate(priv->lowerdev, dev);
521
522 SET_NETDEV_DEV(dev, &priv->lowerdev->dev);
523 dev->ieee80211_ptr = kzalloc(sizeof(*dev->ieee80211_ptr), GFP_KERNEL);
524
525 if (!dev->ieee80211_ptr) {
526 err = -ENOMEM;
527 goto remove_handler;
528 }
529
530 dev->ieee80211_ptr->iftype = NL80211_IFTYPE_STATION;
531 dev->ieee80211_ptr->wiphy = common_wiphy;
532
533 err = register_netdevice(dev);
534 if (err) {
535 dev_err(&priv->lowerdev->dev, "can't register_netdevice: %d\n",
536 err);
537 goto free_wireless_dev;
538 }
539
540 err = netdev_upper_dev_link(priv->lowerdev, dev, extack);
541 if (err) {
542 dev_err(&priv->lowerdev->dev, "can't netdev_upper_dev_link: %d\n",
543 err);
544 goto unregister_netdev;
545 }
546
547 priv->being_deleted = false;
548 priv->is_connected = false;
549 priv->is_up = false;
550 INIT_DELAYED_WORK(&priv->connect, virt_wifi_connect_complete);
551 __module_get(THIS_MODULE);
552
553 return 0;
554 unregister_netdev:
555 unregister_netdevice(dev);
556 free_wireless_dev:
557 kfree(dev->ieee80211_ptr);
558 dev->ieee80211_ptr = NULL;
559 remove_handler:
560 netdev_rx_handler_unregister(priv->lowerdev);
561
562 return err;
563 }
564
565 /* Called with rtnl lock held. */
virt_wifi_dellink(struct net_device * dev,struct list_head * head)566 static void virt_wifi_dellink(struct net_device *dev,
567 struct list_head *head)
568 {
569 struct virt_wifi_netdev_priv *priv = netdev_priv(dev);
570
571 if (dev->ieee80211_ptr)
572 virt_wifi_cancel_scan(dev->ieee80211_ptr->wiphy);
573
574 priv->being_deleted = true;
575 virt_wifi_cancel_connect(dev);
576 netif_carrier_off(dev);
577
578 netdev_rx_handler_unregister(priv->lowerdev);
579 netdev_upper_dev_unlink(priv->lowerdev, dev);
580
581 unregister_netdevice_queue(dev, head);
582 module_put(THIS_MODULE);
583
584 /* Deleting the wiphy is handled in the module destructor. */
585 }
586
587 static struct rtnl_link_ops virt_wifi_link_ops = {
588 .kind = "virt_wifi",
589 .setup = virt_wifi_setup,
590 .newlink = virt_wifi_newlink,
591 .dellink = virt_wifi_dellink,
592 .priv_size = sizeof(struct virt_wifi_netdev_priv),
593 };
594
netif_is_virt_wifi_dev(const struct net_device * dev)595 static bool netif_is_virt_wifi_dev(const struct net_device *dev)
596 {
597 return rcu_access_pointer(dev->rx_handler) == virt_wifi_rx_handler;
598 }
599
virt_wifi_event(struct notifier_block * this,unsigned long event,void * ptr)600 static int virt_wifi_event(struct notifier_block *this, unsigned long event,
601 void *ptr)
602 {
603 struct net_device *lower_dev = netdev_notifier_info_to_dev(ptr);
604 struct virt_wifi_netdev_priv *priv;
605 struct net_device *upper_dev;
606 LIST_HEAD(list_kill);
607
608 if (!netif_is_virt_wifi_dev(lower_dev))
609 return NOTIFY_DONE;
610
611 switch (event) {
612 case NETDEV_UNREGISTER:
613 priv = rtnl_dereference(lower_dev->rx_handler_data);
614 if (!priv)
615 return NOTIFY_DONE;
616
617 upper_dev = priv->upperdev;
618
619 upper_dev->rtnl_link_ops->dellink(upper_dev, &list_kill);
620 unregister_netdevice_many(&list_kill);
621 break;
622 }
623
624 return NOTIFY_DONE;
625 }
626
627 static struct notifier_block virt_wifi_notifier = {
628 .notifier_call = virt_wifi_event,
629 };
630
631 /* Acquires and releases the rtnl lock. */
virt_wifi_init_module(void)632 static int __init virt_wifi_init_module(void)
633 {
634 int err;
635
636 /* Guaranteed to be locallly-administered and not multicast. */
637 eth_random_addr(fake_router_bssid);
638
639 err = register_netdevice_notifier(&virt_wifi_notifier);
640 if (err)
641 return err;
642
643 err = -ENOMEM;
644 common_wiphy = virt_wifi_make_wiphy();
645 if (!common_wiphy)
646 goto notifier;
647
648 err = rtnl_link_register(&virt_wifi_link_ops);
649 if (err)
650 goto destroy_wiphy;
651
652 return 0;
653
654 destroy_wiphy:
655 virt_wifi_destroy_wiphy(common_wiphy);
656 notifier:
657 unregister_netdevice_notifier(&virt_wifi_notifier);
658 return err;
659 }
660
661 /* Acquires and releases the rtnl lock. */
virt_wifi_cleanup_module(void)662 static void __exit virt_wifi_cleanup_module(void)
663 {
664 /* Will delete any devices that depend on the wiphy. */
665 rtnl_link_unregister(&virt_wifi_link_ops);
666 virt_wifi_destroy_wiphy(common_wiphy);
667 unregister_netdevice_notifier(&virt_wifi_notifier);
668 }
669
670 module_init(virt_wifi_init_module);
671 module_exit(virt_wifi_cleanup_module);
672
673 MODULE_LICENSE("GPL v2");
674 MODULE_AUTHOR("Cody Schuffelen <schuffelen@google.com>");
675 MODULE_DESCRIPTION("Driver for a wireless wrapper of ethernet devices");
676 MODULE_ALIAS_RTNL_LINK("virt_wifi");
677
