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10#include <linux/kernel.h>
11#include <linux/mm.h>
12#include <linux/module.h>
13#include <linux/gfp.h>
14#include <linux/usb.h>
15#include <linux/usb/cdc.h>
16#include <linux/netdevice.h>
17#include <linux/if_arp.h>
18#include <linux/if_phonet.h>
19#include <linux/phonet.h>
20
21#define PN_MEDIA_USB 0x1B
22
23static const unsigned rxq_size = 17;
24
25struct usbpn_dev {
26 struct net_device *dev;
27
28 struct usb_interface *intf, *data_intf;
29 struct usb_device *usb;
30 unsigned int tx_pipe, rx_pipe;
31 u8 active_setting;
32 u8 disconnected;
33
34 unsigned tx_queue;
35 spinlock_t tx_lock;
36
37 spinlock_t rx_lock;
38 struct sk_buff *rx_skb;
39 struct urb *urbs[];
40};
41
42static void tx_complete(struct urb *req);
43static void rx_complete(struct urb *req);
44
45
46
47
48static netdev_tx_t usbpn_xmit(struct sk_buff *skb, struct net_device *dev)
49{
50 struct usbpn_dev *pnd = netdev_priv(dev);
51 struct urb *req = NULL;
52 unsigned long flags;
53 int err;
54
55 if (skb->protocol != htons(ETH_P_PHONET))
56 goto drop;
57
58 req = usb_alloc_urb(0, GFP_ATOMIC);
59 if (!req)
60 goto drop;
61 usb_fill_bulk_urb(req, pnd->usb, pnd->tx_pipe, skb->data, skb->len,
62 tx_complete, skb);
63 req->transfer_flags = URB_ZERO_PACKET;
64 err = usb_submit_urb(req, GFP_ATOMIC);
65 if (err) {
66 usb_free_urb(req);
67 goto drop;
68 }
69
70 spin_lock_irqsave(&pnd->tx_lock, flags);
71 pnd->tx_queue++;
72 if (pnd->tx_queue >= dev->tx_queue_len)
73 netif_stop_queue(dev);
74 spin_unlock_irqrestore(&pnd->tx_lock, flags);
75 return NETDEV_TX_OK;
76
77drop:
78 dev_kfree_skb(skb);
79 dev->stats.tx_dropped++;
80 return NETDEV_TX_OK;
81}
82
83static void tx_complete(struct urb *req)
84{
85 struct sk_buff *skb = req->context;
86 struct net_device *dev = skb->dev;
87 struct usbpn_dev *pnd = netdev_priv(dev);
88 int status = req->status;
89 unsigned long flags;
90
91 switch (status) {
92 case 0:
93 dev->stats.tx_bytes += skb->len;
94 break;
95
96 case -ENOENT:
97 case -ECONNRESET:
98 case -ESHUTDOWN:
99 dev->stats.tx_aborted_errors++;
100 fallthrough;
101 default:
102 dev->stats.tx_errors++;
103 dev_dbg(&dev->dev, "TX error (%d)\n", status);
104 }
105 dev->stats.tx_packets++;
106
107 spin_lock_irqsave(&pnd->tx_lock, flags);
108 pnd->tx_queue--;
109 netif_wake_queue(dev);
110 spin_unlock_irqrestore(&pnd->tx_lock, flags);
111
112 dev_kfree_skb_any(skb);
113 usb_free_urb(req);
114}
115
116static int rx_submit(struct usbpn_dev *pnd, struct urb *req, gfp_t gfp_flags)
117{
118 struct net_device *dev = pnd->dev;
119 struct page *page;
120 int err;
121
122 page = __dev_alloc_page(gfp_flags | __GFP_NOMEMALLOC);
123 if (!page)
124 return -ENOMEM;
125
126 usb_fill_bulk_urb(req, pnd->usb, pnd->rx_pipe, page_address(page),
127 PAGE_SIZE, rx_complete, dev);
128 req->transfer_flags = 0;
129 err = usb_submit_urb(req, gfp_flags);
130 if (unlikely(err)) {
131 dev_dbg(&dev->dev, "RX submit error (%d)\n", err);
132 put_page(page);
133 }
134 return err;
135}
136
137static void rx_complete(struct urb *req)
138{
139 struct net_device *dev = req->context;
140 struct usbpn_dev *pnd = netdev_priv(dev);
141 struct page *page = virt_to_page(req->transfer_buffer);
142 struct sk_buff *skb;
143 unsigned long flags;
144 int status = req->status;
145
146 switch (status) {
147 case 0:
148 spin_lock_irqsave(&pnd->rx_lock, flags);
149 skb = pnd->rx_skb;
150 if (!skb) {
151 skb = pnd->rx_skb = netdev_alloc_skb(dev, 12);
152 if (likely(skb)) {
153
154 skb_put_data(skb, page_address(page), 1);
155 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
156 page, 1, req->actual_length,
157 PAGE_SIZE);
158 page = NULL;
159 }
160 } else {
161 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,
162 page, 0, req->actual_length,
163 PAGE_SIZE);
164 page = NULL;
165 }
166 if (req->actual_length < PAGE_SIZE)
167 pnd->rx_skb = NULL;
168 else
169 skb = NULL;
170 spin_unlock_irqrestore(&pnd->rx_lock, flags);
171 if (skb) {
172 skb->protocol = htons(ETH_P_PHONET);
173 skb_reset_mac_header(skb);
174 __skb_pull(skb, 1);
175 skb->dev = dev;
176 dev->stats.rx_packets++;
177 dev->stats.rx_bytes += skb->len;
178
179 netif_rx(skb);
180 }
181 goto resubmit;
182
183 case -ENOENT:
184 case -ECONNRESET:
185 case -ESHUTDOWN:
186 req = NULL;
187 break;
188
189 case -EOVERFLOW:
190 dev->stats.rx_over_errors++;
191 dev_dbg(&dev->dev, "RX overflow\n");
192 break;
193
194 case -EILSEQ:
195 dev->stats.rx_crc_errors++;
196 break;
197 }
198
199 dev->stats.rx_errors++;
200resubmit:
201 if (page)
202 put_page(page);
203 if (req)
204 rx_submit(pnd, req, GFP_ATOMIC);
205}
206
207static int usbpn_close(struct net_device *dev);
208
209static int usbpn_open(struct net_device *dev)
210{
211 struct usbpn_dev *pnd = netdev_priv(dev);
212 int err;
213 unsigned i;
214 unsigned num = pnd->data_intf->cur_altsetting->desc.bInterfaceNumber;
215
216 err = usb_set_interface(pnd->usb, num, pnd->active_setting);
217 if (err)
218 return err;
219
220 for (i = 0; i < rxq_size; i++) {
221 struct urb *req = usb_alloc_urb(0, GFP_KERNEL);
222
223 if (!req || rx_submit(pnd, req, GFP_KERNEL)) {
224 usb_free_urb(req);
225 usbpn_close(dev);
226 return -ENOMEM;
227 }
228 pnd->urbs[i] = req;
229 }
230
231 netif_wake_queue(dev);
232 return 0;
233}
234
235static int usbpn_close(struct net_device *dev)
236{
237 struct usbpn_dev *pnd = netdev_priv(dev);
238 unsigned i;
239 unsigned num = pnd->data_intf->cur_altsetting->desc.bInterfaceNumber;
240
241 netif_stop_queue(dev);
242
243 for (i = 0; i < rxq_size; i++) {
244 struct urb *req = pnd->urbs[i];
245
246 if (!req)
247 continue;
248 usb_kill_urb(req);
249 usb_free_urb(req);
250 pnd->urbs[i] = NULL;
251 }
252
253 return usb_set_interface(pnd->usb, num, !pnd->active_setting);
254}
255
256static int usbpn_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
257 void __user *data, int cmd)
258{
259 struct if_phonet_req *req = (struct if_phonet_req *)ifr;
260
261 switch (cmd) {
262 case SIOCPNGAUTOCONF:
263 req->ifr_phonet_autoconf.device = PN_DEV_PC;
264 return 0;
265 }
266 return -ENOIOCTLCMD;
267}
268
269static const struct net_device_ops usbpn_ops = {
270 .ndo_open = usbpn_open,
271 .ndo_stop = usbpn_close,
272 .ndo_start_xmit = usbpn_xmit,
273 .ndo_siocdevprivate = usbpn_siocdevprivate,
274};
275
276static void usbpn_setup(struct net_device *dev)
277{
278 dev->features = 0;
279 dev->netdev_ops = &usbpn_ops;
280 dev->header_ops = &phonet_header_ops;
281 dev->type = ARPHRD_PHONET;
282 dev->flags = IFF_POINTOPOINT | IFF_NOARP;
283 dev->mtu = PHONET_MAX_MTU;
284 dev->min_mtu = PHONET_MIN_MTU;
285 dev->max_mtu = PHONET_MAX_MTU;
286 dev->hard_header_len = 1;
287 dev->dev_addr[0] = PN_MEDIA_USB;
288 dev->addr_len = 1;
289 dev->tx_queue_len = 3;
290
291 dev->needs_free_netdev = true;
292}
293
294
295
296
297static const struct usb_device_id usbpn_ids[] = {
298 {
299 .match_flags = USB_DEVICE_ID_MATCH_VENDOR
300 | USB_DEVICE_ID_MATCH_INT_CLASS
301 | USB_DEVICE_ID_MATCH_INT_SUBCLASS,
302 .idVendor = 0x0421,
303 .bInterfaceClass = USB_CLASS_COMM,
304 .bInterfaceSubClass = 0xFE,
305 },
306 { },
307};
308
309MODULE_DEVICE_TABLE(usb, usbpn_ids);
310
311static struct usb_driver usbpn_driver;
312
313static int usbpn_probe(struct usb_interface *intf, const struct usb_device_id *id)
314{
315 static const char ifname[] = "usbpn%d";
316 const struct usb_cdc_union_desc *union_header = NULL;
317 const struct usb_host_interface *data_desc;
318 struct usb_interface *data_intf;
319 struct usb_device *usbdev = interface_to_usbdev(intf);
320 struct net_device *dev;
321 struct usbpn_dev *pnd;
322 u8 *data;
323 int phonet = 0;
324 int len, err;
325 struct usb_cdc_parsed_header hdr;
326
327 data = intf->altsetting->extra;
328 len = intf->altsetting->extralen;
329 cdc_parse_cdc_header(&hdr, intf, data, len);
330 union_header = hdr.usb_cdc_union_desc;
331 phonet = hdr.phonet_magic_present;
332
333 if (!union_header || !phonet)
334 return -EINVAL;
335
336 data_intf = usb_ifnum_to_if(usbdev, union_header->bSlaveInterface0);
337 if (data_intf == NULL)
338 return -ENODEV;
339
340 if (data_intf->num_altsetting != 2)
341 return -EINVAL;
342 if (data_intf->altsetting[0].desc.bNumEndpoints == 0 &&
343 data_intf->altsetting[1].desc.bNumEndpoints == 2)
344 data_desc = data_intf->altsetting + 1;
345 else
346 if (data_intf->altsetting[0].desc.bNumEndpoints == 2 &&
347 data_intf->altsetting[1].desc.bNumEndpoints == 0)
348 data_desc = data_intf->altsetting;
349 else
350 return -EINVAL;
351
352 dev = alloc_netdev(struct_size(pnd, urbs, rxq_size), ifname,
353 NET_NAME_UNKNOWN, usbpn_setup);
354 if (!dev)
355 return -ENOMEM;
356
357 pnd = netdev_priv(dev);
358 SET_NETDEV_DEV(dev, &intf->dev);
359
360 pnd->dev = dev;
361 pnd->usb = usbdev;
362 pnd->intf = intf;
363 pnd->data_intf = data_intf;
364 spin_lock_init(&pnd->tx_lock);
365 spin_lock_init(&pnd->rx_lock);
366
367 if (usb_pipein(data_desc->endpoint[0].desc.bEndpointAddress)) {
368 pnd->rx_pipe = usb_rcvbulkpipe(usbdev,
369 data_desc->endpoint[0].desc.bEndpointAddress);
370 pnd->tx_pipe = usb_sndbulkpipe(usbdev,
371 data_desc->endpoint[1].desc.bEndpointAddress);
372 } else {
373 pnd->rx_pipe = usb_rcvbulkpipe(usbdev,
374 data_desc->endpoint[1].desc.bEndpointAddress);
375 pnd->tx_pipe = usb_sndbulkpipe(usbdev,
376 data_desc->endpoint[0].desc.bEndpointAddress);
377 }
378 pnd->active_setting = data_desc - data_intf->altsetting;
379
380 err = usb_driver_claim_interface(&usbpn_driver, data_intf, pnd);
381 if (err)
382 goto out;
383
384
385 usb_set_interface(usbdev, union_header->bSlaveInterface0,
386 !pnd->active_setting);
387 usb_set_intfdata(intf, pnd);
388
389 err = register_netdev(dev);
390 if (err) {
391
392 pnd->disconnected = 1;
393 usb_driver_release_interface(&usbpn_driver, data_intf);
394 goto out;
395 }
396
397 dev_dbg(&dev->dev, "USB CDC Phonet device found\n");
398 return 0;
399
400out:
401 usb_set_intfdata(intf, NULL);
402 free_netdev(dev);
403 return err;
404}
405
406static void usbpn_disconnect(struct usb_interface *intf)
407{
408 struct usbpn_dev *pnd = usb_get_intfdata(intf);
409
410 if (pnd->disconnected)
411 return;
412
413 pnd->disconnected = 1;
414 usb_driver_release_interface(&usbpn_driver,
415 (pnd->intf == intf) ? pnd->data_intf : pnd->intf);
416 unregister_netdev(pnd->dev);
417}
418
419static struct usb_driver usbpn_driver = {
420 .name = "cdc_phonet",
421 .probe = usbpn_probe,
422 .disconnect = usbpn_disconnect,
423 .id_table = usbpn_ids,
424 .disable_hub_initiated_lpm = 1,
425};
426
427module_usb_driver(usbpn_driver);
428
429MODULE_AUTHOR("Remi Denis-Courmont");
430MODULE_DESCRIPTION("USB CDC Phonet host interface");
431MODULE_LICENSE("GPL");
432
