xref: /openbmc/linux/drivers/net/usb/rndis_host.c (revision c4c11dd1)
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 		u32 status = le32_to_cpu(msg->status);
81 
82 		switch (status) {
83 		case RNDIS_STATUS_MEDIA_CONNECT:
84 			dev_info(udev, "rndis media connect\n");
85 			break;
86 		case RNDIS_STATUS_MEDIA_DISCONNECT:
87 			dev_info(udev, "rndis media disconnect\n");
88 			break;
89 		default:
90 			dev_info(udev, "rndis indication: 0x%08x\n", status);
91 		}
92 	}
93 }
94 
95 /*
96  * RPC done RNDIS-style.  Caller guarantees:
97  * - message is properly byteswapped
98  * - there's no other request pending
99  * - buf can hold up to 1KB response (required by RNDIS spec)
100  * On return, the first few entries are already byteswapped.
101  *
102  * Call context is likely probe(), before interface name is known,
103  * which is why we won't try to use it in the diagnostics.
104  */
105 int rndis_command(struct usbnet *dev, struct rndis_msg_hdr *buf, int buflen)
106 {
107 	struct cdc_state	*info = (void *) &dev->data;
108 	struct usb_cdc_notification notification;
109 	int			master_ifnum;
110 	int			retval;
111 	int			partial;
112 	unsigned		count;
113 	u32			xid = 0, msg_len, request_id, msg_type, rsp,
114 				status;
115 
116 	/* REVISIT when this gets called from contexts other than probe() or
117 	 * disconnect(): either serialize, or dispatch responses on xid
118 	 */
119 
120 	msg_type = le32_to_cpu(buf->msg_type);
121 
122 	/* Issue the request; xid is unique, don't bother byteswapping it */
123 	if (likely(msg_type != RNDIS_MSG_HALT && msg_type != RNDIS_MSG_RESET)) {
124 		xid = dev->xid++;
125 		if (!xid)
126 			xid = dev->xid++;
127 		buf->request_id = (__force __le32) xid;
128 	}
129 	master_ifnum = info->control->cur_altsetting->desc.bInterfaceNumber;
130 	retval = usb_control_msg(dev->udev,
131 		usb_sndctrlpipe(dev->udev, 0),
132 		USB_CDC_SEND_ENCAPSULATED_COMMAND,
133 		USB_TYPE_CLASS | USB_RECIP_INTERFACE,
134 		0, master_ifnum,
135 		buf, le32_to_cpu(buf->msg_len),
136 		RNDIS_CONTROL_TIMEOUT_MS);
137 	if (unlikely(retval < 0 || xid == 0))
138 		return retval;
139 
140 	/* Some devices don't respond on the control channel until
141 	 * polled on the status channel, so do that first. */
142 	if (dev->driver_info->data & RNDIS_DRIVER_DATA_POLL_STATUS) {
143 		retval = usb_interrupt_msg(
144 			dev->udev,
145 			usb_rcvintpipe(dev->udev,
146 				       dev->status->desc.bEndpointAddress),
147 			&notification, sizeof(notification), &partial,
148 			RNDIS_CONTROL_TIMEOUT_MS);
149 		if (unlikely(retval < 0))
150 			return retval;
151 	}
152 
153 	/* Poll the control channel; the request probably completed immediately */
154 	rsp = le32_to_cpu(buf->msg_type) | RNDIS_MSG_COMPLETION;
155 	for (count = 0; count < 10; count++) {
156 		memset(buf, 0, CONTROL_BUFFER_SIZE);
157 		retval = usb_control_msg(dev->udev,
158 			usb_rcvctrlpipe(dev->udev, 0),
159 			USB_CDC_GET_ENCAPSULATED_RESPONSE,
160 			USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
161 			0, master_ifnum,
162 			buf, buflen,
163 			RNDIS_CONTROL_TIMEOUT_MS);
164 		if (likely(retval >= 8)) {
165 			msg_type = le32_to_cpu(buf->msg_type);
166 			msg_len = le32_to_cpu(buf->msg_len);
167 			status = le32_to_cpu(buf->status);
168 			request_id = (__force u32) buf->request_id;
169 			if (likely(msg_type == rsp)) {
170 				if (likely(request_id == xid)) {
171 					if (unlikely(rsp == RNDIS_MSG_RESET_C))
172 						return 0;
173 					if (likely(RNDIS_STATUS_SUCCESS ==
174 							status))
175 						return 0;
176 					dev_dbg(&info->control->dev,
177 						"rndis reply status %08x\n",
178 						status);
179 					return -EL3RST;
180 				}
181 				dev_dbg(&info->control->dev,
182 					"rndis reply id %d expected %d\n",
183 					request_id, xid);
184 				/* then likely retry */
185 			} else switch (msg_type) {
186 			case RNDIS_MSG_INDICATE: /* fault/event */
187 				rndis_msg_indicate(dev, (void *)buf, buflen);
188 				break;
189 			case RNDIS_MSG_KEEPALIVE: { /* ping */
190 				struct rndis_keepalive_c *msg = (void *)buf;
191 
192 				msg->msg_type = cpu_to_le32(RNDIS_MSG_KEEPALIVE_C);
193 				msg->msg_len = cpu_to_le32(sizeof *msg);
194 				msg->status = cpu_to_le32(RNDIS_STATUS_SUCCESS);
195 				retval = usb_control_msg(dev->udev,
196 					usb_sndctrlpipe(dev->udev, 0),
197 					USB_CDC_SEND_ENCAPSULATED_COMMAND,
198 					USB_TYPE_CLASS | USB_RECIP_INTERFACE,
199 					0, master_ifnum,
200 					msg, sizeof *msg,
201 					RNDIS_CONTROL_TIMEOUT_MS);
202 				if (unlikely(retval < 0))
203 					dev_dbg(&info->control->dev,
204 						"rndis keepalive err %d\n",
205 						retval);
206 				}
207 				break;
208 			default:
209 				dev_dbg(&info->control->dev,
210 					"unexpected rndis msg %08x len %d\n",
211 					le32_to_cpu(buf->msg_type), msg_len);
212 			}
213 		} else {
214 			/* device probably issued a protocol stall; ignore */
215 			dev_dbg(&info->control->dev,
216 				"rndis response error, code %d\n", retval);
217 		}
218 		msleep(20);
219 	}
220 	dev_dbg(&info->control->dev, "rndis response timeout\n");
221 	return -ETIMEDOUT;
222 }
223 EXPORT_SYMBOL_GPL(rndis_command);
224 
225 /*
226  * rndis_query:
227  *
228  * Performs a query for @oid along with 0 or more bytes of payload as
229  * specified by @in_len. If @reply_len is not set to -1 then the reply
230  * length is checked against this value, resulting in an error if it
231  * doesn't match.
232  *
233  * NOTE: Adding a payload exactly or greater than the size of the expected
234  * response payload is an evident requirement MSFT added for ActiveSync.
235  *
236  * The only exception is for OIDs that return a variably sized response,
237  * in which case no payload should be added.  This undocumented (and
238  * nonsensical!) issue was found by sniffing protocol requests from the
239  * ActiveSync 4.1 Windows driver.
240  */
241 static int rndis_query(struct usbnet *dev, struct usb_interface *intf,
242 		void *buf, u32 oid, u32 in_len,
243 		void **reply, int *reply_len)
244 {
245 	int retval;
246 	union {
247 		void			*buf;
248 		struct rndis_msg_hdr	*header;
249 		struct rndis_query	*get;
250 		struct rndis_query_c	*get_c;
251 	} u;
252 	u32 off, len;
253 
254 	u.buf = buf;
255 
256 	memset(u.get, 0, sizeof *u.get + in_len);
257 	u.get->msg_type = cpu_to_le32(RNDIS_MSG_QUERY);
258 	u.get->msg_len = cpu_to_le32(sizeof *u.get + in_len);
259 	u.get->oid = cpu_to_le32(oid);
260 	u.get->len = cpu_to_le32(in_len);
261 	u.get->offset = cpu_to_le32(20);
262 
263 	retval = rndis_command(dev, u.header, CONTROL_BUFFER_SIZE);
264 	if (unlikely(retval < 0)) {
265 		dev_err(&intf->dev, "RNDIS_MSG_QUERY(0x%08x) failed, %d\n",
266 				oid, retval);
267 		return retval;
268 	}
269 
270 	off = le32_to_cpu(u.get_c->offset);
271 	len = le32_to_cpu(u.get_c->len);
272 	if (unlikely((8 + off + len) > CONTROL_BUFFER_SIZE))
273 		goto response_error;
274 
275 	if (*reply_len != -1 && len != *reply_len)
276 		goto response_error;
277 
278 	*reply = (unsigned char *) &u.get_c->request_id + off;
279 	*reply_len = len;
280 
281 	return retval;
282 
283 response_error:
284 	dev_err(&intf->dev, "RNDIS_MSG_QUERY(0x%08x) "
285 			"invalid response - off %d len %d\n",
286 		oid, off, len);
287 	return -EDOM;
288 }
289 
290 /* same as usbnet_netdev_ops but MTU change not allowed */
291 static const struct net_device_ops rndis_netdev_ops = {
292 	.ndo_open		= usbnet_open,
293 	.ndo_stop		= usbnet_stop,
294 	.ndo_start_xmit		= usbnet_start_xmit,
295 	.ndo_tx_timeout		= usbnet_tx_timeout,
296 	.ndo_set_mac_address 	= eth_mac_addr,
297 	.ndo_validate_addr	= eth_validate_addr,
298 };
299 
300 int
301 generic_rndis_bind(struct usbnet *dev, struct usb_interface *intf, int flags)
302 {
303 	int			retval;
304 	struct net_device	*net = dev->net;
305 	struct cdc_state	*info = (void *) &dev->data;
306 	union {
307 		void			*buf;
308 		struct rndis_msg_hdr	*header;
309 		struct rndis_init	*init;
310 		struct rndis_init_c	*init_c;
311 		struct rndis_query	*get;
312 		struct rndis_query_c	*get_c;
313 		struct rndis_set	*set;
314 		struct rndis_set_c	*set_c;
315 		struct rndis_halt	*halt;
316 	} u;
317 	u32			tmp;
318 	__le32			phym_unspec, *phym;
319 	int			reply_len;
320 	unsigned char		*bp;
321 
322 	/* we can't rely on i/o from stack working, or stack allocation */
323 	u.buf = kmalloc(CONTROL_BUFFER_SIZE, GFP_KERNEL);
324 	if (!u.buf)
325 		return -ENOMEM;
326 	retval = usbnet_generic_cdc_bind(dev, intf);
327 	if (retval < 0)
328 		goto fail;
329 
330 	u.init->msg_type = cpu_to_le32(RNDIS_MSG_INIT);
331 	u.init->msg_len = cpu_to_le32(sizeof *u.init);
332 	u.init->major_version = cpu_to_le32(1);
333 	u.init->minor_version = cpu_to_le32(0);
334 
335 	/* max transfer (in spec) is 0x4000 at full speed, but for
336 	 * TX we'll stick to one Ethernet packet plus RNDIS framing.
337 	 * For RX we handle drivers that zero-pad to end-of-packet.
338 	 * Don't let userspace change these settings.
339 	 *
340 	 * NOTE: there still seems to be wierdness here, as if we need
341 	 * to do some more things to make sure WinCE targets accept this.
342 	 * They default to jumbograms of 8KB or 16KB, which is absurd
343 	 * for such low data rates and which is also more than Linux
344 	 * can usually expect to allocate for SKB data...
345 	 */
346 	net->hard_header_len += sizeof (struct rndis_data_hdr);
347 	dev->hard_mtu = net->mtu + net->hard_header_len;
348 
349 	dev->maxpacket = usb_maxpacket(dev->udev, dev->out, 1);
350 	if (dev->maxpacket == 0) {
351 		netif_dbg(dev, probe, dev->net,
352 			  "dev->maxpacket can't be 0\n");
353 		retval = -EINVAL;
354 		goto fail_and_release;
355 	}
356 
357 	dev->rx_urb_size = dev->hard_mtu + (dev->maxpacket + 1);
358 	dev->rx_urb_size &= ~(dev->maxpacket - 1);
359 	u.init->max_transfer_size = cpu_to_le32(dev->rx_urb_size);
360 
361 	net->netdev_ops = &rndis_netdev_ops;
362 
363 	retval = rndis_command(dev, u.header, CONTROL_BUFFER_SIZE);
364 	if (unlikely(retval < 0)) {
365 		/* it might not even be an RNDIS device!! */
366 		dev_err(&intf->dev, "RNDIS init failed, %d\n", retval);
367 		goto fail_and_release;
368 	}
369 	tmp = le32_to_cpu(u.init_c->max_transfer_size);
370 	if (tmp < dev->hard_mtu) {
371 		if (tmp <= net->hard_header_len) {
372 			dev_err(&intf->dev,
373 				"dev can't take %u byte packets (max %u)\n",
374 				dev->hard_mtu, tmp);
375 			retval = -EINVAL;
376 			goto halt_fail_and_release;
377 		}
378 		dev_warn(&intf->dev,
379 			 "dev can't take %u byte packets (max %u), "
380 			 "adjusting MTU to %u\n",
381 			 dev->hard_mtu, tmp, tmp - net->hard_header_len);
382 		dev->hard_mtu = tmp;
383 		net->mtu = dev->hard_mtu - net->hard_header_len;
384 	}
385 
386 	/* REVISIT:  peripheral "alignment" request is ignored ... */
387 	dev_dbg(&intf->dev,
388 		"hard mtu %u (%u from dev), rx buflen %Zu, align %d\n",
389 		dev->hard_mtu, tmp, dev->rx_urb_size,
390 		1 << le32_to_cpu(u.init_c->packet_alignment));
391 
392 	/* module has some device initialization code needs to be done right
393 	 * after RNDIS_INIT */
394 	if (dev->driver_info->early_init &&
395 			dev->driver_info->early_init(dev) != 0)
396 		goto halt_fail_and_release;
397 
398 	/* Check physical medium */
399 	phym = NULL;
400 	reply_len = sizeof *phym;
401 	retval = rndis_query(dev, intf, u.buf,
402 			     RNDIS_OID_GEN_PHYSICAL_MEDIUM,
403 			     0, (void **) &phym, &reply_len);
404 	if (retval != 0 || !phym) {
405 		/* OID is optional so don't fail here. */
406 		phym_unspec = cpu_to_le32(RNDIS_PHYSICAL_MEDIUM_UNSPECIFIED);
407 		phym = &phym_unspec;
408 	}
409 	if ((flags & FLAG_RNDIS_PHYM_WIRELESS) &&
410 	    le32_to_cpup(phym) != RNDIS_PHYSICAL_MEDIUM_WIRELESS_LAN) {
411 		netif_dbg(dev, probe, dev->net,
412 			  "driver requires wireless physical medium, but device is not\n");
413 		retval = -ENODEV;
414 		goto halt_fail_and_release;
415 	}
416 	if ((flags & FLAG_RNDIS_PHYM_NOT_WIRELESS) &&
417 	    le32_to_cpup(phym) == RNDIS_PHYSICAL_MEDIUM_WIRELESS_LAN) {
418 		netif_dbg(dev, probe, dev->net,
419 			  "driver requires non-wireless physical medium, but device is wireless.\n");
420 		retval = -ENODEV;
421 		goto halt_fail_and_release;
422 	}
423 
424 	/* Get designated host ethernet address */
425 	reply_len = ETH_ALEN;
426 	retval = rndis_query(dev, intf, u.buf,
427 			     RNDIS_OID_802_3_PERMANENT_ADDRESS,
428 			     48, (void **) &bp, &reply_len);
429 	if (unlikely(retval< 0)) {
430 		dev_err(&intf->dev, "rndis get ethaddr, %d\n", retval);
431 		goto halt_fail_and_release;
432 	}
433 	memcpy(net->dev_addr, bp, ETH_ALEN);
434 
435 	/* set a nonzero filter to enable data transfers */
436 	memset(u.set, 0, sizeof *u.set);
437 	u.set->msg_type = cpu_to_le32(RNDIS_MSG_SET);
438 	u.set->msg_len = cpu_to_le32(4 + sizeof *u.set);
439 	u.set->oid = cpu_to_le32(RNDIS_OID_GEN_CURRENT_PACKET_FILTER);
440 	u.set->len = cpu_to_le32(4);
441 	u.set->offset = cpu_to_le32((sizeof *u.set) - 8);
442 	*(__le32 *)(u.buf + sizeof *u.set) = cpu_to_le32(RNDIS_DEFAULT_FILTER);
443 
444 	retval = rndis_command(dev, u.header, CONTROL_BUFFER_SIZE);
445 	if (unlikely(retval < 0)) {
446 		dev_err(&intf->dev, "rndis set packet filter, %d\n", retval);
447 		goto halt_fail_and_release;
448 	}
449 
450 	retval = 0;
451 
452 	kfree(u.buf);
453 	return retval;
454 
455 halt_fail_and_release:
456 	memset(u.halt, 0, sizeof *u.halt);
457 	u.halt->msg_type = cpu_to_le32(RNDIS_MSG_HALT);
458 	u.halt->msg_len = cpu_to_le32(sizeof *u.halt);
459 	(void) rndis_command(dev, (void *)u.halt, CONTROL_BUFFER_SIZE);
460 fail_and_release:
461 	usb_set_intfdata(info->data, NULL);
462 	usb_driver_release_interface(driver_of(intf), info->data);
463 	info->data = NULL;
464 fail:
465 	kfree(u.buf);
466 	return retval;
467 }
468 EXPORT_SYMBOL_GPL(generic_rndis_bind);
469 
470 static int rndis_bind(struct usbnet *dev, struct usb_interface *intf)
471 {
472 	return generic_rndis_bind(dev, intf, FLAG_RNDIS_PHYM_NOT_WIRELESS);
473 }
474 
475 void rndis_unbind(struct usbnet *dev, struct usb_interface *intf)
476 {
477 	struct rndis_halt	*halt;
478 
479 	/* try to clear any rndis state/activity (no i/o from stack!) */
480 	halt = kzalloc(CONTROL_BUFFER_SIZE, GFP_KERNEL);
481 	if (halt) {
482 		halt->msg_type = cpu_to_le32(RNDIS_MSG_HALT);
483 		halt->msg_len = cpu_to_le32(sizeof *halt);
484 		(void) rndis_command(dev, (void *)halt, CONTROL_BUFFER_SIZE);
485 		kfree(halt);
486 	}
487 
488 	usbnet_cdc_unbind(dev, intf);
489 }
490 EXPORT_SYMBOL_GPL(rndis_unbind);
491 
492 /*
493  * DATA -- host must not write zlps
494  */
495 int rndis_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
496 {
497 	/* peripheral may have batched packets to us... */
498 	while (likely(skb->len)) {
499 		struct rndis_data_hdr	*hdr = (void *)skb->data;
500 		struct sk_buff		*skb2;
501 		u32			msg_type, msg_len, data_offset, data_len;
502 
503 		msg_type = le32_to_cpu(hdr->msg_type);
504 		msg_len = le32_to_cpu(hdr->msg_len);
505 		data_offset = le32_to_cpu(hdr->data_offset);
506 		data_len = le32_to_cpu(hdr->data_len);
507 
508 		/* don't choke if we see oob, per-packet data, etc */
509 		if (unlikely(msg_type != RNDIS_MSG_PACKET || skb->len < msg_len
510 				|| (data_offset + data_len + 8) > msg_len)) {
511 			dev->net->stats.rx_frame_errors++;
512 			netdev_dbg(dev->net, "bad rndis message %d/%d/%d/%d, len %d\n",
513 				   le32_to_cpu(hdr->msg_type),
514 				   msg_len, data_offset, data_len, skb->len);
515 			return 0;
516 		}
517 		skb_pull(skb, 8 + data_offset);
518 
519 		/* at most one packet left? */
520 		if (likely((data_len - skb->len) <= sizeof *hdr)) {
521 			skb_trim(skb, data_len);
522 			break;
523 		}
524 
525 		/* try to return all the packets in the batch */
526 		skb2 = skb_clone(skb, GFP_ATOMIC);
527 		if (unlikely(!skb2))
528 			break;
529 		skb_pull(skb, msg_len - sizeof *hdr);
530 		skb_trim(skb2, data_len);
531 		usbnet_skb_return(dev, skb2);
532 	}
533 
534 	/* caller will usbnet_skb_return the remaining packet */
535 	return 1;
536 }
537 EXPORT_SYMBOL_GPL(rndis_rx_fixup);
538 
539 struct sk_buff *
540 rndis_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
541 {
542 	struct rndis_data_hdr	*hdr;
543 	struct sk_buff		*skb2;
544 	unsigned		len = skb->len;
545 
546 	if (likely(!skb_cloned(skb))) {
547 		int	room = skb_headroom(skb);
548 
549 		/* enough head room as-is? */
550 		if (unlikely((sizeof *hdr) <= room))
551 			goto fill;
552 
553 		/* enough room, but needs to be readjusted? */
554 		room += skb_tailroom(skb);
555 		if (likely((sizeof *hdr) <= room)) {
556 			skb->data = memmove(skb->head + sizeof *hdr,
557 					    skb->data, len);
558 			skb_set_tail_pointer(skb, len);
559 			goto fill;
560 		}
561 	}
562 
563 	/* create a new skb, with the correct size (and tailpad) */
564 	skb2 = skb_copy_expand(skb, sizeof *hdr, 1, flags);
565 	dev_kfree_skb_any(skb);
566 	if (unlikely(!skb2))
567 		return skb2;
568 	skb = skb2;
569 
570 	/* fill out the RNDIS header.  we won't bother trying to batch
571 	 * packets; Linux minimizes wasted bandwidth through tx queues.
572 	 */
573 fill:
574 	hdr = (void *) __skb_push(skb, sizeof *hdr);
575 	memset(hdr, 0, sizeof *hdr);
576 	hdr->msg_type = cpu_to_le32(RNDIS_MSG_PACKET);
577 	hdr->msg_len = cpu_to_le32(skb->len);
578 	hdr->data_offset = cpu_to_le32(sizeof(*hdr) - 8);
579 	hdr->data_len = cpu_to_le32(len);
580 
581 	/* FIXME make the last packet always be short ... */
582 	return skb;
583 }
584 EXPORT_SYMBOL_GPL(rndis_tx_fixup);
585 
586 
587 static const struct driver_info	rndis_info = {
588 	.description =	"RNDIS device",
589 	.flags =	FLAG_ETHER | FLAG_POINTTOPOINT | FLAG_FRAMING_RN | FLAG_NO_SETINT,
590 	.bind =		rndis_bind,
591 	.unbind =	rndis_unbind,
592 	.status =	rndis_status,
593 	.rx_fixup =	rndis_rx_fixup,
594 	.tx_fixup =	rndis_tx_fixup,
595 };
596 
597 static const struct driver_info	rndis_poll_status_info = {
598 	.description =	"RNDIS device (poll status before control)",
599 	.flags =	FLAG_ETHER | FLAG_POINTTOPOINT | FLAG_FRAMING_RN | FLAG_NO_SETINT,
600 	.data =		RNDIS_DRIVER_DATA_POLL_STATUS,
601 	.bind =		rndis_bind,
602 	.unbind =	rndis_unbind,
603 	.status =	rndis_status,
604 	.rx_fixup =	rndis_rx_fixup,
605 	.tx_fixup =	rndis_tx_fixup,
606 };
607 
608 /*-------------------------------------------------------------------------*/
609 
610 static const struct usb_device_id	products [] = {
611 {
612 	/* 2Wire HomePortal 1000SW */
613 	USB_DEVICE_AND_INTERFACE_INFO(0x1630, 0x0042,
614 				      USB_CLASS_COMM, 2 /* ACM */, 0x0ff),
615 	.driver_info = (unsigned long) &rndis_poll_status_info,
616 }, {
617 	/* RNDIS is MSFT's un-official variant of CDC ACM */
618 	USB_INTERFACE_INFO(USB_CLASS_COMM, 2 /* ACM */, 0x0ff),
619 	.driver_info = (unsigned long) &rndis_info,
620 }, {
621 	/* "ActiveSync" is an undocumented variant of RNDIS, used in WM5 */
622 	USB_INTERFACE_INFO(USB_CLASS_MISC, 1, 1),
623 	.driver_info = (unsigned long) &rndis_poll_status_info,
624 }, {
625 	/* RNDIS for tethering */
626 	USB_INTERFACE_INFO(USB_CLASS_WIRELESS_CONTROLLER, 1, 3),
627 	.driver_info = (unsigned long) &rndis_info,
628 },
629 	{ },		// END
630 };
631 MODULE_DEVICE_TABLE(usb, products);
632 
633 static struct usb_driver rndis_driver = {
634 	.name =		"rndis_host",
635 	.id_table =	products,
636 	.probe =	usbnet_probe,
637 	.disconnect =	usbnet_disconnect,
638 	.suspend =	usbnet_suspend,
639 	.resume =	usbnet_resume,
640 	.disable_hub_initiated_lpm = 1,
641 };
642 
643 module_usb_driver(rndis_driver);
644 
645 MODULE_AUTHOR("David Brownell");
646 MODULE_DESCRIPTION("USB Host side RNDIS driver");
647 MODULE_LICENSE("GPL");
648