xref: /openbmc/linux/drivers/net/usb/rndis_host.c (revision 81d67439)
1 /*
2  * Host Side support for RNDIS Networking Links
3  * Copyright (C) 2005 by David Brownell
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; either version 2 of the License, or
8  * (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
18  */
19 #include <linux/module.h>
20 #include <linux/init.h>
21 #include <linux/netdevice.h>
22 #include <linux/etherdevice.h>
23 #include <linux/ethtool.h>
24 #include <linux/workqueue.h>
25 #include <linux/slab.h>
26 #include <linux/mii.h>
27 #include <linux/usb.h>
28 #include <linux/usb/cdc.h>
29 #include <linux/usb/usbnet.h>
30 #include <linux/usb/rndis_host.h>
31 
32 
33 /*
34  * RNDIS is NDIS remoted over USB.  It's a MSFT variant of CDC ACM ... of
35  * course ACM was intended for modems, not Ethernet links!  USB's standard
36  * for Ethernet links is "CDC Ethernet", which is significantly simpler.
37  *
38  * NOTE that Microsoft's "RNDIS 1.0" specification is incomplete.  Issues
39  * include:
40  *    - Power management in particular relies on information that's scattered
41  *	through other documentation, and which is incomplete or incorrect even
42  *	there.
43  *    - There are various undocumented protocol requirements, such as the
44  *	need to send unused garbage in control-OUT messages.
45  *    - In some cases, MS-Windows will emit undocumented requests; this
46  *	matters more to peripheral implementations than host ones.
47  *
48  * Moreover there's a no-open-specs variant of RNDIS called "ActiveSync".
49  *
50  * For these reasons and others, ** USE OF RNDIS IS STRONGLY DISCOURAGED ** in
51  * favor of such non-proprietary alternatives as CDC Ethernet or the newer (and
52  * currently rare) "Ethernet Emulation Model" (EEM).
53  */
54 
55 /*
56  * RNDIS notifications from device: command completion; "reverse"
57  * keepalives; etc
58  */
59 void rndis_status(struct usbnet *dev, struct urb *urb)
60 {
61 	netdev_dbg(dev->net, "rndis status urb, len %d stat %d\n",
62 		   urb->actual_length, urb->status);
63 	// FIXME for keepalives, respond immediately (asynchronously)
64 	// if not an RNDIS status, do like cdc_status(dev,urb) does
65 }
66 EXPORT_SYMBOL_GPL(rndis_status);
67 
68 /*
69  * RNDIS indicate messages.
70  */
71 static void rndis_msg_indicate(struct usbnet *dev, struct rndis_indicate *msg,
72 				int buflen)
73 {
74 	struct cdc_state *info = (void *)&dev->data;
75 	struct device *udev = &info->control->dev;
76 
77 	if (dev->driver_info->indication) {
78 		dev->driver_info->indication(dev, msg, buflen);
79 	} else {
80 		switch (msg->status) {
81 		case RNDIS_STATUS_MEDIA_CONNECT:
82 			dev_info(udev, "rndis media connect\n");
83 			break;
84 		case RNDIS_STATUS_MEDIA_DISCONNECT:
85 			dev_info(udev, "rndis media disconnect\n");
86 			break;
87 		default:
88 			dev_info(udev, "rndis indication: 0x%08x\n",
89 					le32_to_cpu(msg->status));
90 		}
91 	}
92 }
93 
94 /*
95  * RPC done RNDIS-style.  Caller guarantees:
96  * - message is properly byteswapped
97  * - there's no other request pending
98  * - buf can hold up to 1KB response (required by RNDIS spec)
99  * On return, the first few entries are already byteswapped.
100  *
101  * Call context is likely probe(), before interface name is known,
102  * which is why we won't try to use it in the diagnostics.
103  */
104 int rndis_command(struct usbnet *dev, struct rndis_msg_hdr *buf, int buflen)
105 {
106 	struct cdc_state	*info = (void *) &dev->data;
107 	struct usb_cdc_notification notification;
108 	int			master_ifnum;
109 	int			retval;
110 	int			partial;
111 	unsigned		count;
112 	__le32			rsp;
113 	u32			xid = 0, msg_len, request_id;
114 
115 	/* REVISIT when this gets called from contexts other than probe() or
116 	 * disconnect(): either serialize, or dispatch responses on xid
117 	 */
118 
119 	/* Issue the request; xid is unique, don't bother byteswapping it */
120 	if (likely(buf->msg_type != RNDIS_MSG_HALT &&
121 		   buf->msg_type != RNDIS_MSG_RESET)) {
122 		xid = dev->xid++;
123 		if (!xid)
124 			xid = dev->xid++;
125 		buf->request_id = (__force __le32) xid;
126 	}
127 	master_ifnum = info->control->cur_altsetting->desc.bInterfaceNumber;
128 	retval = usb_control_msg(dev->udev,
129 		usb_sndctrlpipe(dev->udev, 0),
130 		USB_CDC_SEND_ENCAPSULATED_COMMAND,
131 		USB_TYPE_CLASS | USB_RECIP_INTERFACE,
132 		0, master_ifnum,
133 		buf, le32_to_cpu(buf->msg_len),
134 		RNDIS_CONTROL_TIMEOUT_MS);
135 	if (unlikely(retval < 0 || xid == 0))
136 		return retval;
137 
138 	/* Some devices don't respond on the control channel until
139 	 * polled on the status channel, so do that first. */
140 	if (dev->driver_info->data & RNDIS_DRIVER_DATA_POLL_STATUS) {
141 		retval = usb_interrupt_msg(
142 			dev->udev,
143 			usb_rcvintpipe(dev->udev,
144 				       dev->status->desc.bEndpointAddress),
145 			&notification, sizeof(notification), &partial,
146 			RNDIS_CONTROL_TIMEOUT_MS);
147 		if (unlikely(retval < 0))
148 			return retval;
149 	}
150 
151 	/* Poll the control channel; the request probably completed immediately */
152 	rsp = buf->msg_type | RNDIS_MSG_COMPLETION;
153 	for (count = 0; count < 10; count++) {
154 		memset(buf, 0, CONTROL_BUFFER_SIZE);
155 		retval = usb_control_msg(dev->udev,
156 			usb_rcvctrlpipe(dev->udev, 0),
157 			USB_CDC_GET_ENCAPSULATED_RESPONSE,
158 			USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
159 			0, master_ifnum,
160 			buf, buflen,
161 			RNDIS_CONTROL_TIMEOUT_MS);
162 		if (likely(retval >= 8)) {
163 			msg_len = le32_to_cpu(buf->msg_len);
164 			request_id = (__force u32) buf->request_id;
165 			if (likely(buf->msg_type == rsp)) {
166 				if (likely(request_id == xid)) {
167 					if (unlikely(rsp == RNDIS_MSG_RESET_C))
168 						return 0;
169 					if (likely(RNDIS_STATUS_SUCCESS
170 							== buf->status))
171 						return 0;
172 					dev_dbg(&info->control->dev,
173 						"rndis reply status %08x\n",
174 						le32_to_cpu(buf->status));
175 					return -EL3RST;
176 				}
177 				dev_dbg(&info->control->dev,
178 					"rndis reply id %d expected %d\n",
179 					request_id, xid);
180 				/* then likely retry */
181 			} else switch (buf->msg_type) {
182 			case RNDIS_MSG_INDICATE:	/* fault/event */
183 				rndis_msg_indicate(dev, (void *)buf, buflen);
184 
185 				break;
186 			case RNDIS_MSG_KEEPALIVE: {	/* ping */
187 				struct rndis_keepalive_c *msg = (void *)buf;
188 
189 				msg->msg_type = RNDIS_MSG_KEEPALIVE_C;
190 				msg->msg_len = cpu_to_le32(sizeof *msg);
191 				msg->status = RNDIS_STATUS_SUCCESS;
192 				retval = usb_control_msg(dev->udev,
193 					usb_sndctrlpipe(dev->udev, 0),
194 					USB_CDC_SEND_ENCAPSULATED_COMMAND,
195 					USB_TYPE_CLASS | USB_RECIP_INTERFACE,
196 					0, master_ifnum,
197 					msg, sizeof *msg,
198 					RNDIS_CONTROL_TIMEOUT_MS);
199 				if (unlikely(retval < 0))
200 					dev_dbg(&info->control->dev,
201 						"rndis keepalive err %d\n",
202 						retval);
203 				}
204 				break;
205 			default:
206 				dev_dbg(&info->control->dev,
207 					"unexpected rndis msg %08x len %d\n",
208 					le32_to_cpu(buf->msg_type), msg_len);
209 			}
210 		} else {
211 			/* device probably issued a protocol stall; ignore */
212 			dev_dbg(&info->control->dev,
213 				"rndis response error, code %d\n", retval);
214 		}
215 		msleep(20);
216 	}
217 	dev_dbg(&info->control->dev, "rndis response timeout\n");
218 	return -ETIMEDOUT;
219 }
220 EXPORT_SYMBOL_GPL(rndis_command);
221 
222 /*
223  * rndis_query:
224  *
225  * Performs a query for @oid along with 0 or more bytes of payload as
226  * specified by @in_len. If @reply_len is not set to -1 then the reply
227  * length is checked against this value, resulting in an error if it
228  * doesn't match.
229  *
230  * NOTE: Adding a payload exactly or greater than the size of the expected
231  * response payload is an evident requirement MSFT added for ActiveSync.
232  *
233  * The only exception is for OIDs that return a variably sized response,
234  * in which case no payload should be added.  This undocumented (and
235  * nonsensical!) issue was found by sniffing protocol requests from the
236  * ActiveSync 4.1 Windows driver.
237  */
238 static int rndis_query(struct usbnet *dev, struct usb_interface *intf,
239 		void *buf, __le32 oid, u32 in_len,
240 		void **reply, int *reply_len)
241 {
242 	int retval;
243 	union {
244 		void			*buf;
245 		struct rndis_msg_hdr	*header;
246 		struct rndis_query	*get;
247 		struct rndis_query_c	*get_c;
248 	} u;
249 	u32 off, len;
250 
251 	u.buf = buf;
252 
253 	memset(u.get, 0, sizeof *u.get + in_len);
254 	u.get->msg_type = RNDIS_MSG_QUERY;
255 	u.get->msg_len = cpu_to_le32(sizeof *u.get + in_len);
256 	u.get->oid = oid;
257 	u.get->len = cpu_to_le32(in_len);
258 	u.get->offset = cpu_to_le32(20);
259 
260 	retval = rndis_command(dev, u.header, CONTROL_BUFFER_SIZE);
261 	if (unlikely(retval < 0)) {
262 		dev_err(&intf->dev, "RNDIS_MSG_QUERY(0x%08x) failed, %d\n",
263 				oid, retval);
264 		return retval;
265 	}
266 
267 	off = le32_to_cpu(u.get_c->offset);
268 	len = le32_to_cpu(u.get_c->len);
269 	if (unlikely((8 + off + len) > CONTROL_BUFFER_SIZE))
270 		goto response_error;
271 
272 	if (*reply_len != -1 && len != *reply_len)
273 		goto response_error;
274 
275 	*reply = (unsigned char *) &u.get_c->request_id + off;
276 	*reply_len = len;
277 
278 	return retval;
279 
280 response_error:
281 	dev_err(&intf->dev, "RNDIS_MSG_QUERY(0x%08x) "
282 			"invalid response - off %d len %d\n",
283 		oid, off, len);
284 	return -EDOM;
285 }
286 
287 /* same as usbnet_netdev_ops but MTU change not allowed */
288 static const struct net_device_ops rndis_netdev_ops = {
289 	.ndo_open		= usbnet_open,
290 	.ndo_stop		= usbnet_stop,
291 	.ndo_start_xmit		= usbnet_start_xmit,
292 	.ndo_tx_timeout		= usbnet_tx_timeout,
293 	.ndo_set_mac_address 	= eth_mac_addr,
294 	.ndo_validate_addr	= eth_validate_addr,
295 };
296 
297 int
298 generic_rndis_bind(struct usbnet *dev, struct usb_interface *intf, int flags)
299 {
300 	int			retval;
301 	struct net_device	*net = dev->net;
302 	struct cdc_state	*info = (void *) &dev->data;
303 	union {
304 		void			*buf;
305 		struct rndis_msg_hdr	*header;
306 		struct rndis_init	*init;
307 		struct rndis_init_c	*init_c;
308 		struct rndis_query	*get;
309 		struct rndis_query_c	*get_c;
310 		struct rndis_set	*set;
311 		struct rndis_set_c	*set_c;
312 		struct rndis_halt	*halt;
313 	} u;
314 	u32			tmp;
315 	__le32			phym_unspec, *phym;
316 	int			reply_len;
317 	unsigned char		*bp;
318 
319 	/* we can't rely on i/o from stack working, or stack allocation */
320 	u.buf = kmalloc(CONTROL_BUFFER_SIZE, GFP_KERNEL);
321 	if (!u.buf)
322 		return -ENOMEM;
323 	retval = usbnet_generic_cdc_bind(dev, intf);
324 	if (retval < 0)
325 		goto fail;
326 
327 	u.init->msg_type = RNDIS_MSG_INIT;
328 	u.init->msg_len = cpu_to_le32(sizeof *u.init);
329 	u.init->major_version = cpu_to_le32(1);
330 	u.init->minor_version = cpu_to_le32(0);
331 
332 	/* max transfer (in spec) is 0x4000 at full speed, but for
333 	 * TX we'll stick to one Ethernet packet plus RNDIS framing.
334 	 * For RX we handle drivers that zero-pad to end-of-packet.
335 	 * Don't let userspace change these settings.
336 	 *
337 	 * NOTE: there still seems to be wierdness here, as if we need
338 	 * to do some more things to make sure WinCE targets accept this.
339 	 * They default to jumbograms of 8KB or 16KB, which is absurd
340 	 * for such low data rates and which is also more than Linux
341 	 * can usually expect to allocate for SKB data...
342 	 */
343 	net->hard_header_len += sizeof (struct rndis_data_hdr);
344 	dev->hard_mtu = net->mtu + net->hard_header_len;
345 
346 	dev->maxpacket = usb_maxpacket(dev->udev, dev->out, 1);
347 	if (dev->maxpacket == 0) {
348 		netif_dbg(dev, probe, dev->net,
349 			  "dev->maxpacket can't be 0\n");
350 		retval = -EINVAL;
351 		goto fail_and_release;
352 	}
353 
354 	dev->rx_urb_size = dev->hard_mtu + (dev->maxpacket + 1);
355 	dev->rx_urb_size &= ~(dev->maxpacket - 1);
356 	u.init->max_transfer_size = cpu_to_le32(dev->rx_urb_size);
357 
358 	net->netdev_ops = &rndis_netdev_ops;
359 
360 	retval = rndis_command(dev, u.header, CONTROL_BUFFER_SIZE);
361 	if (unlikely(retval < 0)) {
362 		/* it might not even be an RNDIS device!! */
363 		dev_err(&intf->dev, "RNDIS init failed, %d\n", retval);
364 		goto fail_and_release;
365 	}
366 	tmp = le32_to_cpu(u.init_c->max_transfer_size);
367 	if (tmp < dev->hard_mtu) {
368 		if (tmp <= net->hard_header_len) {
369 			dev_err(&intf->dev,
370 				"dev can't take %u byte packets (max %u)\n",
371 				dev->hard_mtu, tmp);
372 			retval = -EINVAL;
373 			goto halt_fail_and_release;
374 		}
375 		dev_warn(&intf->dev,
376 			 "dev can't take %u byte packets (max %u), "
377 			 "adjusting MTU to %u\n",
378 			 dev->hard_mtu, tmp, tmp - net->hard_header_len);
379 		dev->hard_mtu = tmp;
380 		net->mtu = dev->hard_mtu - net->hard_header_len;
381 	}
382 
383 	/* REVISIT:  peripheral "alignment" request is ignored ... */
384 	dev_dbg(&intf->dev,
385 		"hard mtu %u (%u from dev), rx buflen %Zu, align %d\n",
386 		dev->hard_mtu, tmp, dev->rx_urb_size,
387 		1 << le32_to_cpu(u.init_c->packet_alignment));
388 
389 	/* module has some device initialization code needs to be done right
390 	 * after RNDIS_INIT */
391 	if (dev->driver_info->early_init &&
392 			dev->driver_info->early_init(dev) != 0)
393 		goto halt_fail_and_release;
394 
395 	/* Check physical medium */
396 	phym = NULL;
397 	reply_len = sizeof *phym;
398 	retval = rndis_query(dev, intf, u.buf, OID_GEN_PHYSICAL_MEDIUM,
399 			0, (void **) &phym, &reply_len);
400 	if (retval != 0 || !phym) {
401 		/* OID is optional so don't fail here. */
402 		phym_unspec = RNDIS_PHYSICAL_MEDIUM_UNSPECIFIED;
403 		phym = &phym_unspec;
404 	}
405 	if ((flags & FLAG_RNDIS_PHYM_WIRELESS) &&
406 			*phym != RNDIS_PHYSICAL_MEDIUM_WIRELESS_LAN) {
407 		netif_dbg(dev, probe, dev->net,
408 			  "driver requires wireless physical medium, but device is not\n");
409 		retval = -ENODEV;
410 		goto halt_fail_and_release;
411 	}
412 	if ((flags & FLAG_RNDIS_PHYM_NOT_WIRELESS) &&
413 			*phym == RNDIS_PHYSICAL_MEDIUM_WIRELESS_LAN) {
414 		netif_dbg(dev, probe, dev->net,
415 			  "driver requires non-wireless physical medium, but device is wireless.\n");
416 		retval = -ENODEV;
417 		goto halt_fail_and_release;
418 	}
419 
420 	/* Get designated host ethernet address */
421 	reply_len = ETH_ALEN;
422 	retval = rndis_query(dev, intf, u.buf, OID_802_3_PERMANENT_ADDRESS,
423 			48, (void **) &bp, &reply_len);
424 	if (unlikely(retval< 0)) {
425 		dev_err(&intf->dev, "rndis get ethaddr, %d\n", retval);
426 		goto halt_fail_and_release;
427 	}
428 	memcpy(net->dev_addr, bp, ETH_ALEN);
429 	memcpy(net->perm_addr, bp, ETH_ALEN);
430 
431 	/* set a nonzero filter to enable data transfers */
432 	memset(u.set, 0, sizeof *u.set);
433 	u.set->msg_type = RNDIS_MSG_SET;
434 	u.set->msg_len = cpu_to_le32(4 + sizeof *u.set);
435 	u.set->oid = OID_GEN_CURRENT_PACKET_FILTER;
436 	u.set->len = cpu_to_le32(4);
437 	u.set->offset = cpu_to_le32((sizeof *u.set) - 8);
438 	*(__le32 *)(u.buf + sizeof *u.set) = RNDIS_DEFAULT_FILTER;
439 
440 	retval = rndis_command(dev, u.header, CONTROL_BUFFER_SIZE);
441 	if (unlikely(retval < 0)) {
442 		dev_err(&intf->dev, "rndis set packet filter, %d\n", retval);
443 		goto halt_fail_and_release;
444 	}
445 
446 	retval = 0;
447 
448 	kfree(u.buf);
449 	return retval;
450 
451 halt_fail_and_release:
452 	memset(u.halt, 0, sizeof *u.halt);
453 	u.halt->msg_type = RNDIS_MSG_HALT;
454 	u.halt->msg_len = cpu_to_le32(sizeof *u.halt);
455 	(void) rndis_command(dev, (void *)u.halt, CONTROL_BUFFER_SIZE);
456 fail_and_release:
457 	usb_set_intfdata(info->data, NULL);
458 	usb_driver_release_interface(driver_of(intf), info->data);
459 	info->data = NULL;
460 fail:
461 	kfree(u.buf);
462 	return retval;
463 }
464 EXPORT_SYMBOL_GPL(generic_rndis_bind);
465 
466 static int rndis_bind(struct usbnet *dev, struct usb_interface *intf)
467 {
468 	return generic_rndis_bind(dev, intf, FLAG_RNDIS_PHYM_NOT_WIRELESS);
469 }
470 
471 void rndis_unbind(struct usbnet *dev, struct usb_interface *intf)
472 {
473 	struct rndis_halt	*halt;
474 
475 	/* try to clear any rndis state/activity (no i/o from stack!) */
476 	halt = kzalloc(CONTROL_BUFFER_SIZE, GFP_KERNEL);
477 	if (halt) {
478 		halt->msg_type = RNDIS_MSG_HALT;
479 		halt->msg_len = cpu_to_le32(sizeof *halt);
480 		(void) rndis_command(dev, (void *)halt, CONTROL_BUFFER_SIZE);
481 		kfree(halt);
482 	}
483 
484 	usbnet_cdc_unbind(dev, intf);
485 }
486 EXPORT_SYMBOL_GPL(rndis_unbind);
487 
488 /*
489  * DATA -- host must not write zlps
490  */
491 int rndis_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
492 {
493 	/* peripheral may have batched packets to us... */
494 	while (likely(skb->len)) {
495 		struct rndis_data_hdr	*hdr = (void *)skb->data;
496 		struct sk_buff		*skb2;
497 		u32			msg_len, data_offset, data_len;
498 
499 		msg_len = le32_to_cpu(hdr->msg_len);
500 		data_offset = le32_to_cpu(hdr->data_offset);
501 		data_len = le32_to_cpu(hdr->data_len);
502 
503 		/* don't choke if we see oob, per-packet data, etc */
504 		if (unlikely(hdr->msg_type != RNDIS_MSG_PACKET ||
505 			     skb->len < msg_len ||
506 			     (data_offset + data_len + 8) > msg_len)) {
507 			dev->net->stats.rx_frame_errors++;
508 			netdev_dbg(dev->net, "bad rndis message %d/%d/%d/%d, len %d\n",
509 				   le32_to_cpu(hdr->msg_type),
510 				   msg_len, data_offset, data_len, skb->len);
511 			return 0;
512 		}
513 		skb_pull(skb, 8 + data_offset);
514 
515 		/* at most one packet left? */
516 		if (likely((data_len - skb->len) <= sizeof *hdr)) {
517 			skb_trim(skb, data_len);
518 			break;
519 		}
520 
521 		/* try to return all the packets in the batch */
522 		skb2 = skb_clone(skb, GFP_ATOMIC);
523 		if (unlikely(!skb2))
524 			break;
525 		skb_pull(skb, msg_len - sizeof *hdr);
526 		skb_trim(skb2, data_len);
527 		usbnet_skb_return(dev, skb2);
528 	}
529 
530 	/* caller will usbnet_skb_return the remaining packet */
531 	return 1;
532 }
533 EXPORT_SYMBOL_GPL(rndis_rx_fixup);
534 
535 struct sk_buff *
536 rndis_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
537 {
538 	struct rndis_data_hdr	*hdr;
539 	struct sk_buff		*skb2;
540 	unsigned		len = skb->len;
541 
542 	if (likely(!skb_cloned(skb))) {
543 		int	room = skb_headroom(skb);
544 
545 		/* enough head room as-is? */
546 		if (unlikely((sizeof *hdr) <= room))
547 			goto fill;
548 
549 		/* enough room, but needs to be readjusted? */
550 		room += skb_tailroom(skb);
551 		if (likely((sizeof *hdr) <= room)) {
552 			skb->data = memmove(skb->head + sizeof *hdr,
553 					    skb->data, len);
554 			skb_set_tail_pointer(skb, len);
555 			goto fill;
556 		}
557 	}
558 
559 	/* create a new skb, with the correct size (and tailpad) */
560 	skb2 = skb_copy_expand(skb, sizeof *hdr, 1, flags);
561 	dev_kfree_skb_any(skb);
562 	if (unlikely(!skb2))
563 		return skb2;
564 	skb = skb2;
565 
566 	/* fill out the RNDIS header.  we won't bother trying to batch
567 	 * packets; Linux minimizes wasted bandwidth through tx queues.
568 	 */
569 fill:
570 	hdr = (void *) __skb_push(skb, sizeof *hdr);
571 	memset(hdr, 0, sizeof *hdr);
572 	hdr->msg_type = RNDIS_MSG_PACKET;
573 	hdr->msg_len = cpu_to_le32(skb->len);
574 	hdr->data_offset = cpu_to_le32(sizeof(*hdr) - 8);
575 	hdr->data_len = cpu_to_le32(len);
576 
577 	/* FIXME make the last packet always be short ... */
578 	return skb;
579 }
580 EXPORT_SYMBOL_GPL(rndis_tx_fixup);
581 
582 
583 static const struct driver_info	rndis_info = {
584 	.description =	"RNDIS device",
585 	.flags =	FLAG_ETHER | FLAG_POINTTOPOINT | FLAG_FRAMING_RN | FLAG_NO_SETINT,
586 	.bind =		rndis_bind,
587 	.unbind =	rndis_unbind,
588 	.status =	rndis_status,
589 	.rx_fixup =	rndis_rx_fixup,
590 	.tx_fixup =	rndis_tx_fixup,
591 };
592 
593 static const struct driver_info	rndis_poll_status_info = {
594 	.description =	"RNDIS device (poll status before control)",
595 	.flags =	FLAG_ETHER | FLAG_POINTTOPOINT | FLAG_FRAMING_RN | FLAG_NO_SETINT,
596 	.data =		RNDIS_DRIVER_DATA_POLL_STATUS,
597 	.bind =		rndis_bind,
598 	.unbind =	rndis_unbind,
599 	.status =	rndis_status,
600 	.rx_fixup =	rndis_rx_fixup,
601 	.tx_fixup =	rndis_tx_fixup,
602 };
603 
604 /*-------------------------------------------------------------------------*/
605 
606 static const struct usb_device_id	products [] = {
607 {
608 	/* 2Wire HomePortal 1000SW */
609 	USB_DEVICE_AND_INTERFACE_INFO(0x1630, 0x0042,
610 				      USB_CLASS_COMM, 2 /* ACM */, 0x0ff),
611 	.driver_info = (unsigned long) &rndis_poll_status_info,
612 }, {
613 	/* RNDIS is MSFT's un-official variant of CDC ACM */
614 	USB_INTERFACE_INFO(USB_CLASS_COMM, 2 /* ACM */, 0x0ff),
615 	.driver_info = (unsigned long) &rndis_info,
616 }, {
617 	/* "ActiveSync" is an undocumented variant of RNDIS, used in WM5 */
618 	USB_INTERFACE_INFO(USB_CLASS_MISC, 1, 1),
619 	.driver_info = (unsigned long) &rndis_poll_status_info,
620 }, {
621 	/* RNDIS for tethering */
622 	USB_INTERFACE_INFO(USB_CLASS_WIRELESS_CONTROLLER, 1, 3),
623 	.driver_info = (unsigned long) &rndis_info,
624 },
625 	{ },		// END
626 };
627 MODULE_DEVICE_TABLE(usb, products);
628 
629 static struct usb_driver rndis_driver = {
630 	.name =		"rndis_host",
631 	.id_table =	products,
632 	.probe =	usbnet_probe,
633 	.disconnect =	usbnet_disconnect,
634 	.suspend =	usbnet_suspend,
635 	.resume =	usbnet_resume,
636 };
637 
638 static int __init rndis_init(void)
639 {
640 	return usb_register(&rndis_driver);
641 }
642 module_init(rndis_init);
643 
644 static void __exit rndis_exit(void)
645 {
646 	usb_deregister(&rndis_driver);
647 }
648 module_exit(rndis_exit);
649 
650 MODULE_AUTHOR("David Brownell");
651 MODULE_DESCRIPTION("USB Host side RNDIS driver");
652 MODULE_LICENSE("GPL");
653