xref: /linux/drivers/net/usb/ipheth.c (revision c2933b2befe25309f4c5cfbea0ca80909735fd76)
1 /*
2  * ipheth.c - Apple iPhone USB Ethernet driver
3  *
4  * Copyright (c) 2009 Diego Giagio <diego@giagio.com>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of GIAGIO.COM nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * Alternatively, provided that this notice is retained in full, this
20  * software may be distributed under the terms of the GNU General
21  * Public License ("GPL") version 2, in which case the provisions of the
22  * GPL apply INSTEAD OF those given above.
23  *
24  * The provided data structures and external interfaces from this code
25  * are not restricted to be used by modules with a GPL compatible license.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
30  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
31  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
32  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
33  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
37  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
38  * DAMAGE.
39  *
40  *
41  * Attention: iPhone device must be paired, otherwise it won't respond to our
42  * driver. For more info: http://giagio.com/wiki/moin.cgi/iPhoneEthernetDriver
43  *
44  */
45 
46 #include <linux/kernel.h>
47 #include <linux/errno.h>
48 #include <linux/slab.h>
49 #include <linux/module.h>
50 #include <linux/netdevice.h>
51 #include <linux/etherdevice.h>
52 #include <linux/ethtool.h>
53 #include <linux/usb.h>
54 #include <linux/workqueue.h>
55 #include <linux/usb/cdc.h>
56 
57 #define USB_VENDOR_APPLE        0x05ac
58 
59 #define IPHETH_USBINTF_CLASS    255
60 #define IPHETH_USBINTF_SUBCLASS 253
61 #define IPHETH_USBINTF_PROTO    1
62 
63 #define IPHETH_IP_ALIGN		2	/* padding at front of URB */
64 /* On iOS devices, NCM headers in RX have a fixed size regardless of DPE count:
65  * - NTH16 (NCMH): 12 bytes, as per CDC NCM 1.0 spec
66  * - NDP16 (NCM0): 96 bytes, of which
67  *    - NDP16 fixed header: 8 bytes
68  *    - maximum of 22 DPEs (21 datagrams + trailer), 4 bytes each
69  */
70 #define IPHETH_NDP16_MAX_DPE	22
71 #define IPHETH_NDP16_HEADER_SIZE (sizeof(struct usb_cdc_ncm_ndp16) + \
72 				  IPHETH_NDP16_MAX_DPE * \
73 				  sizeof(struct usb_cdc_ncm_dpe16))
74 #define IPHETH_NCM_HEADER_SIZE	(sizeof(struct usb_cdc_ncm_nth16) + \
75 				 IPHETH_NDP16_HEADER_SIZE)
76 #define IPHETH_TX_BUF_SIZE      ETH_FRAME_LEN
77 #define IPHETH_RX_BUF_SIZE_LEGACY (IPHETH_IP_ALIGN + ETH_FRAME_LEN)
78 #define IPHETH_RX_BUF_SIZE_NCM	65536
79 
80 #define IPHETH_TX_TIMEOUT       (5 * HZ)
81 
82 #define IPHETH_INTFNUM          2
83 #define IPHETH_ALT_INTFNUM      1
84 
85 #define IPHETH_CTRL_ENDP        0x00
86 #define IPHETH_CTRL_BUF_SIZE    0x40
87 #define IPHETH_CTRL_TIMEOUT     (5 * HZ)
88 
89 #define IPHETH_CMD_GET_MACADDR   0x00
90 #define IPHETH_CMD_ENABLE_NCM    0x04
91 #define IPHETH_CMD_CARRIER_CHECK 0x45
92 
93 #define IPHETH_CARRIER_CHECK_TIMEOUT round_jiffies_relative(1 * HZ)
94 #define IPHETH_CARRIER_ON       0x04
95 
96 static const struct usb_device_id ipheth_table[] = {
97 	{ USB_VENDOR_AND_INTERFACE_INFO(USB_VENDOR_APPLE, IPHETH_USBINTF_CLASS,
98 					IPHETH_USBINTF_SUBCLASS,
99 					IPHETH_USBINTF_PROTO) },
100 	{ }
101 };
102 MODULE_DEVICE_TABLE(usb, ipheth_table);
103 
104 struct ipheth_device {
105 	struct usb_device *udev;
106 	struct usb_interface *intf;
107 	struct net_device *net;
108 	struct urb *tx_urb;
109 	struct urb *rx_urb;
110 	unsigned char *tx_buf;
111 	unsigned char *rx_buf;
112 	unsigned char *ctrl_buf;
113 	u8 bulk_in;
114 	u8 bulk_out;
115 	struct delayed_work carrier_work;
116 	bool confirmed_pairing;
117 	int (*rcvbulk_callback)(struct urb *urb);
118 	size_t rx_buf_len;
119 };
120 
121 static int ipheth_rx_submit(struct ipheth_device *dev, gfp_t mem_flags);
122 
ipheth_alloc_urbs(struct ipheth_device * iphone)123 static int ipheth_alloc_urbs(struct ipheth_device *iphone)
124 {
125 	struct urb *tx_urb = NULL;
126 	struct urb *rx_urb = NULL;
127 	u8 *tx_buf = NULL;
128 	u8 *rx_buf = NULL;
129 
130 	tx_urb = usb_alloc_urb(0, GFP_KERNEL);
131 	if (tx_urb == NULL)
132 		goto error_nomem;
133 
134 	rx_urb = usb_alloc_urb(0, GFP_KERNEL);
135 	if (rx_urb == NULL)
136 		goto free_tx_urb;
137 
138 	tx_buf = usb_alloc_coherent(iphone->udev, IPHETH_TX_BUF_SIZE,
139 				    GFP_KERNEL, &tx_urb->transfer_dma);
140 	if (tx_buf == NULL)
141 		goto free_rx_urb;
142 
143 	rx_buf = usb_alloc_coherent(iphone->udev, iphone->rx_buf_len,
144 				    GFP_KERNEL, &rx_urb->transfer_dma);
145 	if (rx_buf == NULL)
146 		goto free_tx_buf;
147 
148 
149 	iphone->tx_urb = tx_urb;
150 	iphone->rx_urb = rx_urb;
151 	iphone->tx_buf = tx_buf;
152 	iphone->rx_buf = rx_buf;
153 	return 0;
154 
155 free_tx_buf:
156 	usb_free_coherent(iphone->udev, IPHETH_TX_BUF_SIZE, tx_buf,
157 			  tx_urb->transfer_dma);
158 free_rx_urb:
159 	usb_free_urb(rx_urb);
160 free_tx_urb:
161 	usb_free_urb(tx_urb);
162 error_nomem:
163 	return -ENOMEM;
164 }
165 
ipheth_free_urbs(struct ipheth_device * iphone)166 static void ipheth_free_urbs(struct ipheth_device *iphone)
167 {
168 	usb_free_coherent(iphone->udev, iphone->rx_buf_len, iphone->rx_buf,
169 			  iphone->rx_urb->transfer_dma);
170 	usb_free_coherent(iphone->udev, IPHETH_TX_BUF_SIZE, iphone->tx_buf,
171 			  iphone->tx_urb->transfer_dma);
172 	usb_free_urb(iphone->rx_urb);
173 	usb_free_urb(iphone->tx_urb);
174 }
175 
ipheth_kill_urbs(struct ipheth_device * dev)176 static void ipheth_kill_urbs(struct ipheth_device *dev)
177 {
178 	usb_kill_urb(dev->tx_urb);
179 	usb_kill_urb(dev->rx_urb);
180 }
181 
ipheth_consume_skb(char * buf,int len,struct ipheth_device * dev)182 static int ipheth_consume_skb(char *buf, int len, struct ipheth_device *dev)
183 {
184 	struct sk_buff *skb;
185 
186 	skb = dev_alloc_skb(len);
187 	if (!skb) {
188 		dev->net->stats.rx_dropped++;
189 		return -ENOMEM;
190 	}
191 
192 	skb_put_data(skb, buf, len);
193 	skb->dev = dev->net;
194 	skb->protocol = eth_type_trans(skb, dev->net);
195 
196 	dev->net->stats.rx_packets++;
197 	dev->net->stats.rx_bytes += len;
198 	netif_rx(skb);
199 
200 	return 0;
201 }
202 
ipheth_rcvbulk_callback_legacy(struct urb * urb)203 static int ipheth_rcvbulk_callback_legacy(struct urb *urb)
204 {
205 	struct ipheth_device *dev;
206 	char *buf;
207 	int len;
208 
209 	dev = urb->context;
210 
211 	if (urb->actual_length <= IPHETH_IP_ALIGN) {
212 		dev->net->stats.rx_length_errors++;
213 		return -EINVAL;
214 	}
215 	len = urb->actual_length - IPHETH_IP_ALIGN;
216 	buf = urb->transfer_buffer + IPHETH_IP_ALIGN;
217 
218 	return ipheth_consume_skb(buf, len, dev);
219 }
220 
221 /* In "NCM mode", the iOS device encapsulates RX (phone->computer) traffic
222  * in NCM Transfer Blocks (similarly to CDC NCM). However, unlike reverse
223  * tethering (handled by the `cdc_ncm` driver), regular tethering is not
224  * compliant with the CDC NCM spec, as the device is missing the necessary
225  * descriptors, and TX (computer->phone) traffic is not encapsulated
226  * at all. Thus `ipheth` implements a very limited subset of the spec with
227  * the sole purpose of parsing RX URBs.
228  */
ipheth_rcvbulk_callback_ncm(struct urb * urb)229 static int ipheth_rcvbulk_callback_ncm(struct urb *urb)
230 {
231 	struct usb_cdc_ncm_nth16 *ncmh;
232 	struct usb_cdc_ncm_ndp16 *ncm0;
233 	struct usb_cdc_ncm_dpe16 *dpe;
234 	struct ipheth_device *dev;
235 	u16 dg_idx, dg_len;
236 	int retval = -EINVAL;
237 	char *buf;
238 
239 	dev = urb->context;
240 
241 	if (urb->actual_length < IPHETH_NCM_HEADER_SIZE) {
242 		dev->net->stats.rx_length_errors++;
243 		return retval;
244 	}
245 
246 	ncmh = urb->transfer_buffer;
247 	if (ncmh->dwSignature != cpu_to_le32(USB_CDC_NCM_NTH16_SIGN) ||
248 	    /* On iOS, NDP16 directly follows NTH16 */
249 	    ncmh->wNdpIndex != cpu_to_le16(sizeof(struct usb_cdc_ncm_nth16)))
250 		goto rx_error;
251 
252 	ncm0 = urb->transfer_buffer + sizeof(struct usb_cdc_ncm_nth16);
253 	if (ncm0->dwSignature != cpu_to_le32(USB_CDC_NCM_NDP16_NOCRC_SIGN))
254 		goto rx_error;
255 
256 	dpe = ncm0->dpe16;
257 	for (int dpe_i = 0; dpe_i < IPHETH_NDP16_MAX_DPE; ++dpe_i, ++dpe) {
258 		dg_idx = le16_to_cpu(dpe->wDatagramIndex);
259 		dg_len = le16_to_cpu(dpe->wDatagramLength);
260 
261 		/* Null DPE must be present after last datagram pointer entry
262 		 * (3.3.1 USB CDC NCM spec v1.0)
263 		 */
264 		if (dg_idx == 0 && dg_len == 0)
265 			return 0;
266 
267 		if (dg_idx < IPHETH_NCM_HEADER_SIZE ||
268 		    dg_idx >= urb->actual_length ||
269 		    dg_len > urb->actual_length - dg_idx) {
270 			dev->net->stats.rx_length_errors++;
271 			return retval;
272 		}
273 
274 		buf = urb->transfer_buffer + dg_idx;
275 
276 		retval = ipheth_consume_skb(buf, dg_len, dev);
277 		if (retval != 0)
278 			return retval;
279 	}
280 
281 rx_error:
282 	dev->net->stats.rx_errors++;
283 	return retval;
284 }
285 
ipheth_rcvbulk_callback(struct urb * urb)286 static void ipheth_rcvbulk_callback(struct urb *urb)
287 {
288 	struct ipheth_device *dev;
289 	int retval, status;
290 
291 	dev = urb->context;
292 	if (dev == NULL)
293 		return;
294 
295 	status = urb->status;
296 	switch (status) {
297 	case -ENOENT:
298 	case -ECONNRESET:
299 	case -ESHUTDOWN:
300 	case -EPROTO:
301 		return;
302 	case 0:
303 		break;
304 	default:
305 		dev_err(&dev->intf->dev, "%s: urb status: %d\n",
306 			__func__, status);
307 		return;
308 	}
309 
310 	/* iPhone may periodically send URBs with no payload
311 	 * on the "bulk in" endpoint. It is safe to ignore them.
312 	 */
313 	if (urb->actual_length == 0)
314 		goto rx_submit;
315 
316 	/* RX URBs starting with 0x00 0x01 do not encapsulate Ethernet frames,
317 	 * but rather are control frames. Their purpose is not documented, and
318 	 * they don't affect driver functionality, okay to drop them.
319 	 * There is usually just one 4-byte control frame as the very first
320 	 * URB received from the bulk IN endpoint.
321 	 */
322 	if (unlikely
323 		(urb->actual_length == 4 &&
324 		 ((char *)urb->transfer_buffer)[0] == 0 &&
325 		 ((char *)urb->transfer_buffer)[1] == 1))
326 		goto rx_submit;
327 
328 	retval = dev->rcvbulk_callback(urb);
329 	if (retval != 0) {
330 		dev_err(&dev->intf->dev, "%s: callback retval: %d\n",
331 			__func__, retval);
332 	}
333 
334 rx_submit:
335 	dev->confirmed_pairing = true;
336 	ipheth_rx_submit(dev, GFP_ATOMIC);
337 }
338 
ipheth_sndbulk_callback(struct urb * urb)339 static void ipheth_sndbulk_callback(struct urb *urb)
340 {
341 	struct ipheth_device *dev;
342 	int status = urb->status;
343 
344 	dev = urb->context;
345 	if (dev == NULL)
346 		return;
347 
348 	if (status != 0 &&
349 	    status != -ENOENT &&
350 	    status != -ECONNRESET &&
351 	    status != -ESHUTDOWN)
352 		dev_err(&dev->intf->dev, "%s: urb status: %d\n",
353 		__func__, status);
354 
355 	if (status == 0)
356 		netif_wake_queue(dev->net);
357 	else
358 		// on URB error, trigger immediate poll
359 		schedule_delayed_work(&dev->carrier_work, 0);
360 }
361 
ipheth_carrier_set(struct ipheth_device * dev)362 static int ipheth_carrier_set(struct ipheth_device *dev)
363 {
364 	struct usb_device *udev;
365 	int retval;
366 
367 	if (!dev->confirmed_pairing)
368 		return 0;
369 
370 	udev = dev->udev;
371 	retval = usb_control_msg(udev,
372 			usb_rcvctrlpipe(udev, IPHETH_CTRL_ENDP),
373 			IPHETH_CMD_CARRIER_CHECK, /* request */
374 			0xc0, /* request type */
375 			0x00, /* value */
376 			0x02, /* index */
377 			dev->ctrl_buf, IPHETH_CTRL_BUF_SIZE,
378 			IPHETH_CTRL_TIMEOUT);
379 	if (retval <= 0) {
380 		dev_err(&dev->intf->dev, "%s: usb_control_msg: %d\n",
381 			__func__, retval);
382 		return retval;
383 	}
384 
385 	if ((retval == 1 && dev->ctrl_buf[0] == IPHETH_CARRIER_ON) ||
386 	    (retval >= 2 && dev->ctrl_buf[1] == IPHETH_CARRIER_ON)) {
387 		netif_carrier_on(dev->net);
388 		if (dev->tx_urb->status != -EINPROGRESS)
389 			netif_wake_queue(dev->net);
390 	} else {
391 		netif_carrier_off(dev->net);
392 		netif_stop_queue(dev->net);
393 	}
394 	return 0;
395 }
396 
ipheth_carrier_check_work(struct work_struct * work)397 static void ipheth_carrier_check_work(struct work_struct *work)
398 {
399 	struct ipheth_device *dev = container_of(work, struct ipheth_device,
400 						 carrier_work.work);
401 
402 	ipheth_carrier_set(dev);
403 	schedule_delayed_work(&dev->carrier_work, IPHETH_CARRIER_CHECK_TIMEOUT);
404 }
405 
ipheth_get_macaddr(struct ipheth_device * dev)406 static int ipheth_get_macaddr(struct ipheth_device *dev)
407 {
408 	struct usb_device *udev = dev->udev;
409 	struct net_device *net = dev->net;
410 	int retval;
411 
412 	retval = usb_control_msg(udev,
413 				 usb_rcvctrlpipe(udev, IPHETH_CTRL_ENDP),
414 				 IPHETH_CMD_GET_MACADDR, /* request */
415 				 0xc0, /* request type */
416 				 0x00, /* value */
417 				 0x02, /* index */
418 				 dev->ctrl_buf,
419 				 IPHETH_CTRL_BUF_SIZE,
420 				 IPHETH_CTRL_TIMEOUT);
421 	if (retval < 0) {
422 		dev_err(&dev->intf->dev, "%s: usb_control_msg: %d\n",
423 			__func__, retval);
424 	} else if (retval < ETH_ALEN) {
425 		dev_err(&dev->intf->dev,
426 			"%s: usb_control_msg: short packet: %d bytes\n",
427 			__func__, retval);
428 		retval = -EINVAL;
429 	} else {
430 		eth_hw_addr_set(net, dev->ctrl_buf);
431 		retval = 0;
432 	}
433 
434 	return retval;
435 }
436 
ipheth_enable_ncm(struct ipheth_device * dev)437 static int ipheth_enable_ncm(struct ipheth_device *dev)
438 {
439 	struct usb_device *udev = dev->udev;
440 	int retval;
441 
442 	retval = usb_control_msg(udev,
443 				 usb_sndctrlpipe(udev, IPHETH_CTRL_ENDP),
444 				 IPHETH_CMD_ENABLE_NCM, /* request */
445 				 0x41, /* request type */
446 				 0x00, /* value */
447 				 0x02, /* index */
448 				 NULL,
449 				 0,
450 				 IPHETH_CTRL_TIMEOUT);
451 
452 	dev_info(&dev->intf->dev, "%s: usb_control_msg: %d\n",
453 		 __func__, retval);
454 
455 	return retval;
456 }
457 
ipheth_rx_submit(struct ipheth_device * dev,gfp_t mem_flags)458 static int ipheth_rx_submit(struct ipheth_device *dev, gfp_t mem_flags)
459 {
460 	struct usb_device *udev = dev->udev;
461 	int retval;
462 
463 	usb_fill_bulk_urb(dev->rx_urb, udev,
464 			  usb_rcvbulkpipe(udev, dev->bulk_in),
465 			  dev->rx_buf, dev->rx_buf_len,
466 			  ipheth_rcvbulk_callback,
467 			  dev);
468 	dev->rx_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
469 
470 	retval = usb_submit_urb(dev->rx_urb, mem_flags);
471 	if (retval)
472 		dev_err(&dev->intf->dev, "%s: usb_submit_urb: %d\n",
473 			__func__, retval);
474 	return retval;
475 }
476 
ipheth_open(struct net_device * net)477 static int ipheth_open(struct net_device *net)
478 {
479 	struct ipheth_device *dev = netdev_priv(net);
480 	struct usb_device *udev = dev->udev;
481 	int retval = 0;
482 
483 	usb_set_interface(udev, IPHETH_INTFNUM, IPHETH_ALT_INTFNUM);
484 
485 	retval = ipheth_carrier_set(dev);
486 	if (retval)
487 		return retval;
488 
489 	retval = ipheth_rx_submit(dev, GFP_KERNEL);
490 	if (retval)
491 		return retval;
492 
493 	schedule_delayed_work(&dev->carrier_work, IPHETH_CARRIER_CHECK_TIMEOUT);
494 	return retval;
495 }
496 
ipheth_close(struct net_device * net)497 static int ipheth_close(struct net_device *net)
498 {
499 	struct ipheth_device *dev = netdev_priv(net);
500 
501 	netif_stop_queue(net);
502 	cancel_delayed_work_sync(&dev->carrier_work);
503 	return 0;
504 }
505 
ipheth_tx(struct sk_buff * skb,struct net_device * net)506 static netdev_tx_t ipheth_tx(struct sk_buff *skb, struct net_device *net)
507 {
508 	struct ipheth_device *dev = netdev_priv(net);
509 	struct usb_device *udev = dev->udev;
510 	int retval;
511 
512 	/* Paranoid */
513 	if (skb->len > IPHETH_TX_BUF_SIZE) {
514 		WARN(1, "%s: skb too large: %d bytes\n", __func__, skb->len);
515 		dev->net->stats.tx_dropped++;
516 		dev_kfree_skb_any(skb);
517 		return NETDEV_TX_OK;
518 	}
519 
520 	memcpy(dev->tx_buf, skb->data, skb->len);
521 
522 	usb_fill_bulk_urb(dev->tx_urb, udev,
523 			  usb_sndbulkpipe(udev, dev->bulk_out),
524 			  dev->tx_buf, skb->len,
525 			  ipheth_sndbulk_callback,
526 			  dev);
527 	dev->tx_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
528 
529 	netif_stop_queue(net);
530 	retval = usb_submit_urb(dev->tx_urb, GFP_ATOMIC);
531 	if (retval) {
532 		dev_err(&dev->intf->dev, "%s: usb_submit_urb: %d\n",
533 			__func__, retval);
534 		dev->net->stats.tx_errors++;
535 		dev_kfree_skb_any(skb);
536 		netif_wake_queue(net);
537 	} else {
538 		dev->net->stats.tx_packets++;
539 		dev->net->stats.tx_bytes += skb->len;
540 		dev_consume_skb_any(skb);
541 	}
542 
543 	return NETDEV_TX_OK;
544 }
545 
ipheth_tx_timeout(struct net_device * net,unsigned int txqueue)546 static void ipheth_tx_timeout(struct net_device *net, unsigned int txqueue)
547 {
548 	struct ipheth_device *dev = netdev_priv(net);
549 
550 	dev_err(&dev->intf->dev, "%s: TX timeout\n", __func__);
551 	dev->net->stats.tx_errors++;
552 	usb_unlink_urb(dev->tx_urb);
553 }
554 
ipheth_ethtool_op_get_link(struct net_device * net)555 static u32 ipheth_ethtool_op_get_link(struct net_device *net)
556 {
557 	struct ipheth_device *dev = netdev_priv(net);
558 	return netif_carrier_ok(dev->net);
559 }
560 
561 static const struct ethtool_ops ops = {
562 	.get_link = ipheth_ethtool_op_get_link
563 };
564 
565 static const struct net_device_ops ipheth_netdev_ops = {
566 	.ndo_open = ipheth_open,
567 	.ndo_stop = ipheth_close,
568 	.ndo_start_xmit = ipheth_tx,
569 	.ndo_tx_timeout = ipheth_tx_timeout,
570 };
571 
ipheth_probe(struct usb_interface * intf,const struct usb_device_id * id)572 static int ipheth_probe(struct usb_interface *intf,
573 			const struct usb_device_id *id)
574 {
575 	struct usb_device *udev = interface_to_usbdev(intf);
576 	struct usb_host_interface *hintf;
577 	struct usb_endpoint_descriptor *endp;
578 	struct ipheth_device *dev;
579 	struct net_device *netdev;
580 	int i;
581 	int retval;
582 
583 	netdev = alloc_etherdev(sizeof(struct ipheth_device));
584 	if (!netdev)
585 		return -ENOMEM;
586 
587 	netdev->netdev_ops = &ipheth_netdev_ops;
588 	netdev->watchdog_timeo = IPHETH_TX_TIMEOUT;
589 	strscpy(netdev->name, "eth%d", sizeof(netdev->name));
590 
591 	dev = netdev_priv(netdev);
592 	dev->udev = udev;
593 	dev->net = netdev;
594 	dev->intf = intf;
595 	dev->confirmed_pairing = false;
596 	dev->rx_buf_len = IPHETH_RX_BUF_SIZE_LEGACY;
597 	dev->rcvbulk_callback = ipheth_rcvbulk_callback_legacy;
598 	/* Set up endpoints */
599 	hintf = usb_altnum_to_altsetting(intf, IPHETH_ALT_INTFNUM);
600 	if (hintf == NULL) {
601 		retval = -ENODEV;
602 		dev_err(&intf->dev, "Unable to find alternate settings interface\n");
603 		goto err_endpoints;
604 	}
605 
606 	for (i = 0; i < hintf->desc.bNumEndpoints; i++) {
607 		endp = &hintf->endpoint[i].desc;
608 		if (usb_endpoint_is_bulk_in(endp))
609 			dev->bulk_in = endp->bEndpointAddress;
610 		else if (usb_endpoint_is_bulk_out(endp))
611 			dev->bulk_out = endp->bEndpointAddress;
612 	}
613 	if (!(dev->bulk_in && dev->bulk_out)) {
614 		retval = -ENODEV;
615 		dev_err(&intf->dev, "Unable to find endpoints\n");
616 		goto err_endpoints;
617 	}
618 
619 	dev->ctrl_buf = kmalloc(IPHETH_CTRL_BUF_SIZE, GFP_KERNEL);
620 	if (dev->ctrl_buf == NULL) {
621 		retval = -ENOMEM;
622 		goto err_alloc_ctrl_buf;
623 	}
624 
625 	retval = ipheth_get_macaddr(dev);
626 	if (retval)
627 		goto err_get_macaddr;
628 
629 	retval = ipheth_enable_ncm(dev);
630 	if (!retval) {
631 		dev->rx_buf_len = IPHETH_RX_BUF_SIZE_NCM;
632 		dev->rcvbulk_callback = ipheth_rcvbulk_callback_ncm;
633 	}
634 
635 	INIT_DELAYED_WORK(&dev->carrier_work, ipheth_carrier_check_work);
636 
637 	retval = ipheth_alloc_urbs(dev);
638 	if (retval) {
639 		dev_err(&intf->dev, "error allocating urbs: %d\n", retval);
640 		goto err_alloc_urbs;
641 	}
642 
643 	usb_set_intfdata(intf, dev);
644 
645 	SET_NETDEV_DEV(netdev, &intf->dev);
646 	netdev->ethtool_ops = &ops;
647 
648 	retval = register_netdev(netdev);
649 	if (retval) {
650 		dev_err(&intf->dev, "error registering netdev: %d\n", retval);
651 		retval = -EIO;
652 		goto err_register_netdev;
653 	}
654 	// carrier down and transmit queues stopped until packet from device
655 	netif_carrier_off(netdev);
656 	netif_tx_stop_all_queues(netdev);
657 	dev_info(&intf->dev, "Apple iPhone USB Ethernet device attached\n");
658 	return 0;
659 
660 err_register_netdev:
661 	ipheth_free_urbs(dev);
662 err_alloc_urbs:
663 err_get_macaddr:
664 	kfree(dev->ctrl_buf);
665 err_alloc_ctrl_buf:
666 err_endpoints:
667 	free_netdev(netdev);
668 	return retval;
669 }
670 
ipheth_disconnect(struct usb_interface * intf)671 static void ipheth_disconnect(struct usb_interface *intf)
672 {
673 	struct ipheth_device *dev;
674 
675 	dev = usb_get_intfdata(intf);
676 	if (dev != NULL) {
677 		unregister_netdev(dev->net);
678 		ipheth_kill_urbs(dev);
679 		ipheth_free_urbs(dev);
680 		kfree(dev->ctrl_buf);
681 		free_netdev(dev->net);
682 	}
683 	usb_set_intfdata(intf, NULL);
684 	dev_info(&intf->dev, "Apple iPhone USB Ethernet now disconnected\n");
685 }
686 
687 static struct usb_driver ipheth_driver = {
688 	.name =		"ipheth",
689 	.probe =	ipheth_probe,
690 	.disconnect =	ipheth_disconnect,
691 	.id_table =	ipheth_table,
692 	.disable_hub_initiated_lpm = 1,
693 };
694 
695 module_usb_driver(ipheth_driver);
696 
697 MODULE_AUTHOR("Diego Giagio <diego@giagio.com>");
698 MODULE_DESCRIPTION("Apple iPhone USB Ethernet driver");
699 MODULE_LICENSE("Dual BSD/GPL");
700