2 * Host Side support for RNDIS Networking Links
3 * Copyright (C) 2005 by David Brownell
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.
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.
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
20 // #define DEBUG // error path messages, extra info
21 // #define VERBOSE // more; success messages
23 #include <linux/module.h>
24 #include <linux/init.h>
25 #include <linux/netdevice.h>
26 #include <linux/etherdevice.h>
27 #include <linux/ethtool.h>
28 #include <linux/workqueue.h>
29 #include <linux/mii.h>
30 #include <linux/usb.h>
31 #include <linux/usb/cdc.h>
32 #include <linux/usb/usbnet.h>
33 #include <linux/usb/rndis_host.h>
37 * RNDIS is NDIS remoted over USB. It's a MSFT variant of CDC ACM ... of
38 * course ACM was intended for modems, not Ethernet links! USB's standard
39 * for Ethernet links is "CDC Ethernet", which is significantly simpler.
41 * NOTE that Microsoft's "RNDIS 1.0" specification is incomplete. Issues
43 * - Power management in particular relies on information that's scattered
44 * through other documentation, and which is incomplete or incorrect even
46 * - There are various undocumented protocol requirements, such as the
47 * need to send unused garbage in control-OUT messages.
48 * - In some cases, MS-Windows will emit undocumented requests; this
49 * matters more to peripheral implementations than host ones.
51 * Moreover there's a no-open-specs variant of RNDIS called "ActiveSync".
53 * For these reasons and others, ** USE OF RNDIS IS STRONGLY DISCOURAGED ** in
54 * favor of such non-proprietary alternatives as CDC Ethernet or the newer (and
55 * currently rare) "Ethernet Emulation Model" (EEM).
59 * RNDIS notifications from device: command completion; "reverse"
62 void rndis_status(struct usbnet *dev, struct urb *urb)
64 devdbg(dev, "rndis status urb, len %d stat %d",
65 urb->actual_length, urb->status);
66 // FIXME for keepalives, respond immediately (asynchronously)
67 // if not an RNDIS status, do like cdc_status(dev,urb) does
69 EXPORT_SYMBOL_GPL(rndis_status);
72 * RPC done RNDIS-style. Caller guarantees:
73 * - message is properly byteswapped
74 * - there's no other request pending
75 * - buf can hold up to 1KB response (required by RNDIS spec)
76 * On return, the first few entries are already byteswapped.
78 * Call context is likely probe(), before interface name is known,
79 * which is why we won't try to use it in the diagnostics.
81 int rndis_command(struct usbnet *dev, struct rndis_msg_hdr *buf)
83 struct cdc_state *info = (void *) &dev->data;
88 u32 xid = 0, msg_len, request_id;
90 /* REVISIT when this gets called from contexts other than probe() or
91 * disconnect(): either serialize, or dispatch responses on xid
94 /* Issue the request; xid is unique, don't bother byteswapping it */
95 if (likely(buf->msg_type != RNDIS_MSG_HALT
96 && buf->msg_type != RNDIS_MSG_RESET)) {
100 buf->request_id = (__force __le32) xid;
102 master_ifnum = info->control->cur_altsetting->desc.bInterfaceNumber;
103 retval = usb_control_msg(dev->udev,
104 usb_sndctrlpipe(dev->udev, 0),
105 USB_CDC_SEND_ENCAPSULATED_COMMAND,
106 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
108 buf, le32_to_cpu(buf->msg_len),
109 RNDIS_CONTROL_TIMEOUT_MS);
110 if (unlikely(retval < 0 || xid == 0))
113 // FIXME Seems like some devices discard responses when
114 // we time out and cancel our "get response" requests...
115 // so, this is fragile. Probably need to poll for status.
117 /* ignore status endpoint, just poll the control channel;
118 * the request probably completed immediately
120 rsp = buf->msg_type | RNDIS_MSG_COMPLETION;
121 for (count = 0; count < 10; count++) {
122 memset(buf, 0, CONTROL_BUFFER_SIZE);
123 retval = usb_control_msg(dev->udev,
124 usb_rcvctrlpipe(dev->udev, 0),
125 USB_CDC_GET_ENCAPSULATED_RESPONSE,
126 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
128 buf, CONTROL_BUFFER_SIZE,
129 RNDIS_CONTROL_TIMEOUT_MS);
130 if (likely(retval >= 8)) {
131 msg_len = le32_to_cpu(buf->msg_len);
132 request_id = (__force u32) buf->request_id;
133 if (likely(buf->msg_type == rsp)) {
134 if (likely(request_id == xid)) {
135 if (unlikely(rsp == RNDIS_MSG_RESET_C))
137 if (likely(RNDIS_STATUS_SUCCESS
140 dev_dbg(&info->control->dev,
141 "rndis reply status %08x\n",
142 le32_to_cpu(buf->status));
145 dev_dbg(&info->control->dev,
146 "rndis reply id %d expected %d\n",
148 /* then likely retry */
149 } else switch (buf->msg_type) {
150 case RNDIS_MSG_INDICATE: { /* fault/event */
151 struct rndis_indicate *msg = (void *)buf;
154 switch (msg->status) {
155 case RNDIS_STATUS_MEDIA_CONNECT:
157 case RNDIS_STATUS_MEDIA_DISCONNECT:
158 dev_info(&info->control->dev,
159 "rndis media %sconnect\n",
161 if (dev->driver_info->link_change)
162 dev->driver_info->link_change(
166 dev_info(&info->control->dev,
167 "rndis indication: 0x%08x\n",
168 le32_to_cpu(msg->status));
172 case RNDIS_MSG_KEEPALIVE: { /* ping */
173 struct rndis_keepalive_c *msg = (void *)buf;
175 msg->msg_type = RNDIS_MSG_KEEPALIVE_C;
176 msg->msg_len = ccpu2(sizeof *msg);
177 msg->status = RNDIS_STATUS_SUCCESS;
178 retval = usb_control_msg(dev->udev,
179 usb_sndctrlpipe(dev->udev, 0),
180 USB_CDC_SEND_ENCAPSULATED_COMMAND,
181 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
184 RNDIS_CONTROL_TIMEOUT_MS);
185 if (unlikely(retval < 0))
186 dev_dbg(&info->control->dev,
187 "rndis keepalive err %d\n",
192 dev_dbg(&info->control->dev,
193 "unexpected rndis msg %08x len %d\n",
194 le32_to_cpu(buf->msg_type), msg_len);
197 /* device probably issued a protocol stall; ignore */
198 dev_dbg(&info->control->dev,
199 "rndis response error, code %d\n", retval);
203 dev_dbg(&info->control->dev, "rndis response timeout\n");
206 EXPORT_SYMBOL_GPL(rndis_command);
211 * Performs a query for @oid along with 0 or more bytes of payload as
212 * specified by @in_len. If @reply_len is not set to -1 then the reply
213 * length is checked against this value, resulting in an error if it
216 * NOTE: Adding a payload exactly or greater than the size of the expected
217 * response payload is an evident requirement MSFT added for ActiveSync.
219 * The only exception is for OIDs that return a variably sized response,
220 * in which case no payload should be added. This undocumented (and
221 * nonsensical!) issue was found by sniffing protocol requests from the
222 * ActiveSync 4.1 Windows driver.
224 static int rndis_query(struct usbnet *dev, struct usb_interface *intf,
225 void *buf, u32 oid, u32 in_len,
226 void **reply, int *reply_len)
231 struct rndis_msg_hdr *header;
232 struct rndis_query *get;
233 struct rndis_query_c *get_c;
239 memset(u.get, 0, sizeof *u.get + in_len);
240 u.get->msg_type = RNDIS_MSG_QUERY;
241 u.get->msg_len = cpu_to_le32(sizeof *u.get + in_len);
243 u.get->len = cpu_to_le32(in_len);
244 u.get->offset = ccpu2(20);
246 retval = rndis_command(dev, u.header);
247 if (unlikely(retval < 0)) {
248 dev_err(&intf->dev, "RNDIS_MSG_QUERY(0x%08x) failed, %d\n",
253 off = le32_to_cpu(u.get_c->offset);
254 len = le32_to_cpu(u.get_c->len);
255 if (unlikely((8 + off + len) > CONTROL_BUFFER_SIZE))
258 if (*reply_len != -1 && len != *reply_len)
261 *reply = (unsigned char *) &u.get_c->request_id + off;
267 dev_err(&intf->dev, "RNDIS_MSG_QUERY(0x%08x) "
268 "invalid response - off %d len %d\n",
274 generic_rndis_bind(struct usbnet *dev, struct usb_interface *intf, int flags)
277 struct net_device *net = dev->net;
278 struct cdc_state *info = (void *) &dev->data;
281 struct rndis_msg_hdr *header;
282 struct rndis_init *init;
283 struct rndis_init_c *init_c;
284 struct rndis_query *get;
285 struct rndis_query_c *get_c;
286 struct rndis_set *set;
287 struct rndis_set_c *set_c;
288 struct rndis_halt *halt;
294 /* we can't rely on i/o from stack working, or stack allocation */
295 u.buf = kmalloc(CONTROL_BUFFER_SIZE, GFP_KERNEL);
298 retval = usbnet_generic_cdc_bind(dev, intf);
302 u.init->msg_type = RNDIS_MSG_INIT;
303 u.init->msg_len = ccpu2(sizeof *u.init);
304 u.init->major_version = ccpu2(1);
305 u.init->minor_version = ccpu2(0);
307 /* max transfer (in spec) is 0x4000 at full speed, but for
308 * TX we'll stick to one Ethernet packet plus RNDIS framing.
309 * For RX we handle drivers that zero-pad to end-of-packet.
310 * Don't let userspace change these settings.
312 * NOTE: there still seems to be wierdness here, as if we need
313 * to do some more things to make sure WinCE targets accept this.
314 * They default to jumbograms of 8KB or 16KB, which is absurd
315 * for such low data rates and which is also more than Linux
316 * can usually expect to allocate for SKB data...
318 net->hard_header_len += sizeof (struct rndis_data_hdr);
319 dev->hard_mtu = net->mtu + net->hard_header_len;
321 dev->rx_urb_size = dev->hard_mtu + (dev->maxpacket + 1);
322 dev->rx_urb_size &= ~(dev->maxpacket - 1);
323 u.init->max_transfer_size = cpu_to_le32(dev->rx_urb_size);
325 net->change_mtu = NULL;
326 retval = rndis_command(dev, u.header);
327 if (unlikely(retval < 0)) {
328 /* it might not even be an RNDIS device!! */
329 dev_err(&intf->dev, "RNDIS init failed, %d\n", retval);
330 goto fail_and_release;
332 tmp = le32_to_cpu(u.init_c->max_transfer_size);
333 if (tmp < dev->hard_mtu) {
334 if (tmp <= net->hard_header_len) {
336 "dev can't take %u byte packets (max %u)\n",
339 goto halt_fail_and_release;
342 net->mtu = dev->hard_mtu - net->hard_header_len;
344 "dev can't take %u byte packets (max %u), "
345 "adjusting MTU to %u\n",
346 dev->hard_mtu, tmp, net->mtu);
349 /* REVISIT: peripheral "alignment" request is ignored ... */
351 "hard mtu %u (%u from dev), rx buflen %Zu, align %d\n",
352 dev->hard_mtu, tmp, dev->rx_urb_size,
353 1 << le32_to_cpu(u.init_c->packet_alignment));
355 /* module has some device initialization code needs to be done right
356 * after RNDIS_INIT */
357 if (dev->driver_info->early_init &&
358 dev->driver_info->early_init(dev) != 0)
359 goto halt_fail_and_release;
361 /* Check physical medium */
362 reply_len = sizeof *phym;
363 retval = rndis_query(dev, intf, u.buf, OID_GEN_PHYSICAL_MEDIUM,
364 0, (void **) &phym, &reply_len);
366 /* OID is optional so don't fail here. */
367 *phym = RNDIS_PHYSICAL_MEDIUM_UNSPECIFIED;
368 if ((flags & FLAG_RNDIS_PHYM_WIRELESS) &&
369 *phym != RNDIS_PHYSICAL_MEDIUM_WIRELESS_LAN) {
370 if (netif_msg_probe(dev))
371 dev_dbg(&intf->dev, "driver requires wireless "
372 "physical medium, but device is not.\n");
374 goto halt_fail_and_release;
376 if ((flags & FLAG_RNDIS_PHYM_NOT_WIRELESS) &&
377 *phym == RNDIS_PHYSICAL_MEDIUM_WIRELESS_LAN) {
378 if (netif_msg_probe(dev))
379 dev_dbg(&intf->dev, "driver requires non-wireless "
380 "physical medium, but device is wireless.\n");
382 goto halt_fail_and_release;
385 /* Get designated host ethernet address */
386 reply_len = ETH_ALEN;
387 retval = rndis_query(dev, intf, u.buf, OID_802_3_PERMANENT_ADDRESS,
388 48, (void **) &bp, &reply_len);
389 if (unlikely(retval< 0)) {
390 dev_err(&intf->dev, "rndis get ethaddr, %d\n", retval);
391 goto halt_fail_and_release;
393 memcpy(net->dev_addr, bp, ETH_ALEN);
395 /* set a nonzero filter to enable data transfers */
396 memset(u.set, 0, sizeof *u.set);
397 u.set->msg_type = RNDIS_MSG_SET;
398 u.set->msg_len = ccpu2(4 + sizeof *u.set);
399 u.set->oid = OID_GEN_CURRENT_PACKET_FILTER;
400 u.set->len = ccpu2(4);
401 u.set->offset = ccpu2((sizeof *u.set) - 8);
402 *(__le32 *)(u.buf + sizeof *u.set) = RNDIS_DEFAULT_FILTER;
404 retval = rndis_command(dev, u.header);
405 if (unlikely(retval < 0)) {
406 dev_err(&intf->dev, "rndis set packet filter, %d\n", retval);
407 goto halt_fail_and_release;
415 halt_fail_and_release:
416 memset(u.halt, 0, sizeof *u.halt);
417 u.halt->msg_type = RNDIS_MSG_HALT;
418 u.halt->msg_len = ccpu2(sizeof *u.halt);
419 (void) rndis_command(dev, (void *)u.halt);
421 usb_set_intfdata(info->data, NULL);
422 usb_driver_release_interface(driver_of(intf), info->data);
428 EXPORT_SYMBOL_GPL(generic_rndis_bind);
430 static int rndis_bind(struct usbnet *dev, struct usb_interface *intf)
432 return generic_rndis_bind(dev, intf, FLAG_RNDIS_PHYM_NOT_WIRELESS);
435 void rndis_unbind(struct usbnet *dev, struct usb_interface *intf)
437 struct rndis_halt *halt;
439 /* try to clear any rndis state/activity (no i/o from stack!) */
440 halt = kzalloc(CONTROL_BUFFER_SIZE, GFP_KERNEL);
442 halt->msg_type = RNDIS_MSG_HALT;
443 halt->msg_len = ccpu2(sizeof *halt);
444 (void) rndis_command(dev, (void *)halt);
448 usbnet_cdc_unbind(dev, intf);
450 EXPORT_SYMBOL_GPL(rndis_unbind);
453 * DATA -- host must not write zlps
455 int rndis_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
457 /* peripheral may have batched packets to us... */
458 while (likely(skb->len)) {
459 struct rndis_data_hdr *hdr = (void *)skb->data;
460 struct sk_buff *skb2;
461 u32 msg_len, data_offset, data_len;
463 msg_len = le32_to_cpu(hdr->msg_len);
464 data_offset = le32_to_cpu(hdr->data_offset);
465 data_len = le32_to_cpu(hdr->data_len);
467 /* don't choke if we see oob, per-packet data, etc */
468 if (unlikely(hdr->msg_type != RNDIS_MSG_PACKET
469 || skb->len < msg_len
470 || (data_offset + data_len + 8) > msg_len)) {
471 dev->stats.rx_frame_errors++;
472 devdbg(dev, "bad rndis message %d/%d/%d/%d, len %d",
473 le32_to_cpu(hdr->msg_type),
474 msg_len, data_offset, data_len, skb->len);
477 skb_pull(skb, 8 + data_offset);
479 /* at most one packet left? */
480 if (likely((data_len - skb->len) <= sizeof *hdr)) {
481 skb_trim(skb, data_len);
485 /* try to return all the packets in the batch */
486 skb2 = skb_clone(skb, GFP_ATOMIC);
489 skb_pull(skb, msg_len - sizeof *hdr);
490 skb_trim(skb2, data_len);
491 usbnet_skb_return(dev, skb2);
494 /* caller will usbnet_skb_return the remaining packet */
497 EXPORT_SYMBOL_GPL(rndis_rx_fixup);
500 rndis_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
502 struct rndis_data_hdr *hdr;
503 struct sk_buff *skb2;
504 unsigned len = skb->len;
506 if (likely(!skb_cloned(skb))) {
507 int room = skb_headroom(skb);
509 /* enough head room as-is? */
510 if (unlikely((sizeof *hdr) <= room))
513 /* enough room, but needs to be readjusted? */
514 room += skb_tailroom(skb);
515 if (likely((sizeof *hdr) <= room)) {
516 skb->data = memmove(skb->head + sizeof *hdr,
518 skb_set_tail_pointer(skb, len);
523 /* create a new skb, with the correct size (and tailpad) */
524 skb2 = skb_copy_expand(skb, sizeof *hdr, 1, flags);
525 dev_kfree_skb_any(skb);
530 /* fill out the RNDIS header. we won't bother trying to batch
531 * packets; Linux minimizes wasted bandwidth through tx queues.
534 hdr = (void *) __skb_push(skb, sizeof *hdr);
535 memset(hdr, 0, sizeof *hdr);
536 hdr->msg_type = RNDIS_MSG_PACKET;
537 hdr->msg_len = cpu_to_le32(skb->len);
538 hdr->data_offset = ccpu2(sizeof(*hdr) - 8);
539 hdr->data_len = cpu_to_le32(len);
541 /* FIXME make the last packet always be short ... */
544 EXPORT_SYMBOL_GPL(rndis_tx_fixup);
547 static const struct driver_info rndis_info = {
548 .description = "RNDIS device",
549 .flags = FLAG_ETHER | FLAG_FRAMING_RN | FLAG_NO_SETINT,
551 .unbind = rndis_unbind,
552 .status = rndis_status,
553 .rx_fixup = rndis_rx_fixup,
554 .tx_fixup = rndis_tx_fixup,
560 /*-------------------------------------------------------------------------*/
562 static const struct usb_device_id products [] = {
564 /* RNDIS is MSFT's un-official variant of CDC ACM */
565 USB_INTERFACE_INFO(USB_CLASS_COMM, 2 /* ACM */, 0x0ff),
566 .driver_info = (unsigned long) &rndis_info,
568 /* "ActiveSync" is an undocumented variant of RNDIS, used in WM5 */
569 USB_INTERFACE_INFO(USB_CLASS_MISC, 1, 1),
570 .driver_info = (unsigned long) &rndis_info,
574 MODULE_DEVICE_TABLE(usb, products);
576 static struct usb_driver rndis_driver = {
577 .name = "rndis_host",
578 .id_table = products,
579 .probe = usbnet_probe,
580 .disconnect = usbnet_disconnect,
581 .suspend = usbnet_suspend,
582 .resume = usbnet_resume,
585 static int __init rndis_init(void)
587 return usb_register(&rndis_driver);
589 module_init(rndis_init);
591 static void __exit rndis_exit(void)
593 usb_deregister(&rndis_driver);
595 module_exit(rndis_exit);
597 MODULE_AUTHOR("David Brownell");
598 MODULE_DESCRIPTION("USB Host side RNDIS driver");
599 MODULE_LICENSE("GPL");