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
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/mii.h>
26 #include <linux/usb.h>
27 #include <linux/usb/cdc.h>
28 #include <linux/usb/usbnet.h>
29 #include <linux/usb/rndis_host.h>
33 * RNDIS is NDIS remoted over USB. It's a MSFT variant of CDC ACM ... of
34 * course ACM was intended for modems, not Ethernet links! USB's standard
35 * for Ethernet links is "CDC Ethernet", which is significantly simpler.
37 * NOTE that Microsoft's "RNDIS 1.0" specification is incomplete. Issues
39 * - Power management in particular relies on information that's scattered
40 * through other documentation, and which is incomplete or incorrect even
42 * - There are various undocumented protocol requirements, such as the
43 * need to send unused garbage in control-OUT messages.
44 * - In some cases, MS-Windows will emit undocumented requests; this
45 * matters more to peripheral implementations than host ones.
47 * Moreover there's a no-open-specs variant of RNDIS called "ActiveSync".
49 * For these reasons and others, ** USE OF RNDIS IS STRONGLY DISCOURAGED ** in
50 * favor of such non-proprietary alternatives as CDC Ethernet or the newer (and
51 * currently rare) "Ethernet Emulation Model" (EEM).
55 * RNDIS notifications from device: command completion; "reverse"
58 void rndis_status(struct usbnet *dev, struct urb *urb)
60 devdbg(dev, "rndis status urb, len %d stat %d",
61 urb->actual_length, urb->status);
62 // FIXME for keepalives, respond immediately (asynchronously)
63 // if not an RNDIS status, do like cdc_status(dev,urb) does
65 EXPORT_SYMBOL_GPL(rndis_status);
68 * RPC done RNDIS-style. Caller guarantees:
69 * - message is properly byteswapped
70 * - there's no other request pending
71 * - buf can hold up to 1KB response (required by RNDIS spec)
72 * On return, the first few entries are already byteswapped.
74 * Call context is likely probe(), before interface name is known,
75 * which is why we won't try to use it in the diagnostics.
77 int rndis_command(struct usbnet *dev, struct rndis_msg_hdr *buf)
79 struct cdc_state *info = (void *) &dev->data;
84 u32 xid = 0, msg_len, request_id;
86 /* REVISIT when this gets called from contexts other than probe() or
87 * disconnect(): either serialize, or dispatch responses on xid
90 /* Issue the request; xid is unique, don't bother byteswapping it */
91 if (likely(buf->msg_type != RNDIS_MSG_HALT
92 && buf->msg_type != RNDIS_MSG_RESET)) {
96 buf->request_id = (__force __le32) xid;
98 master_ifnum = info->control->cur_altsetting->desc.bInterfaceNumber;
99 retval = usb_control_msg(dev->udev,
100 usb_sndctrlpipe(dev->udev, 0),
101 USB_CDC_SEND_ENCAPSULATED_COMMAND,
102 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
104 buf, le32_to_cpu(buf->msg_len),
105 RNDIS_CONTROL_TIMEOUT_MS);
106 if (unlikely(retval < 0 || xid == 0))
109 // FIXME Seems like some devices discard responses when
110 // we time out and cancel our "get response" requests...
111 // so, this is fragile. Probably need to poll for status.
113 /* ignore status endpoint, just poll the control channel;
114 * the request probably completed immediately
116 rsp = buf->msg_type | RNDIS_MSG_COMPLETION;
117 for (count = 0; count < 10; count++) {
118 memset(buf, 0, CONTROL_BUFFER_SIZE);
119 retval = usb_control_msg(dev->udev,
120 usb_rcvctrlpipe(dev->udev, 0),
121 USB_CDC_GET_ENCAPSULATED_RESPONSE,
122 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
124 buf, CONTROL_BUFFER_SIZE,
125 RNDIS_CONTROL_TIMEOUT_MS);
126 if (likely(retval >= 8)) {
127 msg_len = le32_to_cpu(buf->msg_len);
128 request_id = (__force u32) buf->request_id;
129 if (likely(buf->msg_type == rsp)) {
130 if (likely(request_id == xid)) {
131 if (unlikely(rsp == RNDIS_MSG_RESET_C))
133 if (likely(RNDIS_STATUS_SUCCESS
136 dev_dbg(&info->control->dev,
137 "rndis reply status %08x\n",
138 le32_to_cpu(buf->status));
141 dev_dbg(&info->control->dev,
142 "rndis reply id %d expected %d\n",
144 /* then likely retry */
145 } else switch (buf->msg_type) {
146 case RNDIS_MSG_INDICATE: { /* fault/event */
147 struct rndis_indicate *msg = (void *)buf;
150 switch (msg->status) {
151 case RNDIS_STATUS_MEDIA_CONNECT:
153 case RNDIS_STATUS_MEDIA_DISCONNECT:
154 dev_info(&info->control->dev,
155 "rndis media %sconnect\n",
157 if (dev->driver_info->link_change)
158 dev->driver_info->link_change(
162 dev_info(&info->control->dev,
163 "rndis indication: 0x%08x\n",
164 le32_to_cpu(msg->status));
168 case RNDIS_MSG_KEEPALIVE: { /* ping */
169 struct rndis_keepalive_c *msg = (void *)buf;
171 msg->msg_type = RNDIS_MSG_KEEPALIVE_C;
172 msg->msg_len = ccpu2(sizeof *msg);
173 msg->status = RNDIS_STATUS_SUCCESS;
174 retval = usb_control_msg(dev->udev,
175 usb_sndctrlpipe(dev->udev, 0),
176 USB_CDC_SEND_ENCAPSULATED_COMMAND,
177 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
180 RNDIS_CONTROL_TIMEOUT_MS);
181 if (unlikely(retval < 0))
182 dev_dbg(&info->control->dev,
183 "rndis keepalive err %d\n",
188 dev_dbg(&info->control->dev,
189 "unexpected rndis msg %08x len %d\n",
190 le32_to_cpu(buf->msg_type), msg_len);
193 /* device probably issued a protocol stall; ignore */
194 dev_dbg(&info->control->dev,
195 "rndis response error, code %d\n", retval);
199 dev_dbg(&info->control->dev, "rndis response timeout\n");
202 EXPORT_SYMBOL_GPL(rndis_command);
207 * Performs a query for @oid along with 0 or more bytes of payload as
208 * specified by @in_len. If @reply_len is not set to -1 then the reply
209 * length is checked against this value, resulting in an error if it
212 * NOTE: Adding a payload exactly or greater than the size of the expected
213 * response payload is an evident requirement MSFT added for ActiveSync.
215 * The only exception is for OIDs that return a variably sized response,
216 * in which case no payload should be added. This undocumented (and
217 * nonsensical!) issue was found by sniffing protocol requests from the
218 * ActiveSync 4.1 Windows driver.
220 static int rndis_query(struct usbnet *dev, struct usb_interface *intf,
221 void *buf, u32 oid, u32 in_len,
222 void **reply, int *reply_len)
227 struct rndis_msg_hdr *header;
228 struct rndis_query *get;
229 struct rndis_query_c *get_c;
235 memset(u.get, 0, sizeof *u.get + in_len);
236 u.get->msg_type = RNDIS_MSG_QUERY;
237 u.get->msg_len = cpu_to_le32(sizeof *u.get + in_len);
239 u.get->len = cpu_to_le32(in_len);
240 u.get->offset = ccpu2(20);
242 retval = rndis_command(dev, u.header);
243 if (unlikely(retval < 0)) {
244 dev_err(&intf->dev, "RNDIS_MSG_QUERY(0x%08x) failed, %d\n",
249 off = le32_to_cpu(u.get_c->offset);
250 len = le32_to_cpu(u.get_c->len);
251 if (unlikely((8 + off + len) > CONTROL_BUFFER_SIZE))
254 if (*reply_len != -1 && len != *reply_len)
257 *reply = (unsigned char *) &u.get_c->request_id + off;
263 dev_err(&intf->dev, "RNDIS_MSG_QUERY(0x%08x) "
264 "invalid response - off %d len %d\n",
270 generic_rndis_bind(struct usbnet *dev, struct usb_interface *intf, int flags)
273 struct net_device *net = dev->net;
274 struct cdc_state *info = (void *) &dev->data;
277 struct rndis_msg_hdr *header;
278 struct rndis_init *init;
279 struct rndis_init_c *init_c;
280 struct rndis_query *get;
281 struct rndis_query_c *get_c;
282 struct rndis_set *set;
283 struct rndis_set_c *set_c;
284 struct rndis_halt *halt;
290 /* we can't rely on i/o from stack working, or stack allocation */
291 u.buf = kmalloc(CONTROL_BUFFER_SIZE, GFP_KERNEL);
294 retval = usbnet_generic_cdc_bind(dev, intf);
298 u.init->msg_type = RNDIS_MSG_INIT;
299 u.init->msg_len = ccpu2(sizeof *u.init);
300 u.init->major_version = ccpu2(1);
301 u.init->minor_version = ccpu2(0);
303 /* max transfer (in spec) is 0x4000 at full speed, but for
304 * TX we'll stick to one Ethernet packet plus RNDIS framing.
305 * For RX we handle drivers that zero-pad to end-of-packet.
306 * Don't let userspace change these settings.
308 * NOTE: there still seems to be wierdness here, as if we need
309 * to do some more things to make sure WinCE targets accept this.
310 * They default to jumbograms of 8KB or 16KB, which is absurd
311 * for such low data rates and which is also more than Linux
312 * can usually expect to allocate for SKB data...
314 net->hard_header_len += sizeof (struct rndis_data_hdr);
315 dev->hard_mtu = net->mtu + net->hard_header_len;
317 dev->maxpacket = usb_maxpacket(dev->udev, dev->out, 1);
318 if (dev->maxpacket == 0) {
319 if (netif_msg_probe(dev))
320 dev_dbg(&intf->dev, "dev->maxpacket can't be 0\n");
322 goto fail_and_release;
325 dev->rx_urb_size = dev->hard_mtu + (dev->maxpacket + 1);
326 dev->rx_urb_size &= ~(dev->maxpacket - 1);
327 u.init->max_transfer_size = cpu_to_le32(dev->rx_urb_size);
329 net->change_mtu = NULL;
330 retval = rndis_command(dev, u.header);
331 if (unlikely(retval < 0)) {
332 /* it might not even be an RNDIS device!! */
333 dev_err(&intf->dev, "RNDIS init failed, %d\n", retval);
334 goto fail_and_release;
336 tmp = le32_to_cpu(u.init_c->max_transfer_size);
337 if (tmp < dev->hard_mtu) {
338 if (tmp <= net->hard_header_len) {
340 "dev can't take %u byte packets (max %u)\n",
343 goto halt_fail_and_release;
346 net->mtu = dev->hard_mtu - net->hard_header_len;
348 "dev can't take %u byte packets (max %u), "
349 "adjusting MTU to %u\n",
350 dev->hard_mtu, tmp, net->mtu);
353 /* REVISIT: peripheral "alignment" request is ignored ... */
355 "hard mtu %u (%u from dev), rx buflen %Zu, align %d\n",
356 dev->hard_mtu, tmp, dev->rx_urb_size,
357 1 << le32_to_cpu(u.init_c->packet_alignment));
359 /* module has some device initialization code needs to be done right
360 * after RNDIS_INIT */
361 if (dev->driver_info->early_init &&
362 dev->driver_info->early_init(dev) != 0)
363 goto halt_fail_and_release;
365 /* Check physical medium */
366 reply_len = sizeof *phym;
367 retval = rndis_query(dev, intf, u.buf, OID_GEN_PHYSICAL_MEDIUM,
368 0, (void **) &phym, &reply_len);
370 /* OID is optional so don't fail here. */
371 *phym = RNDIS_PHYSICAL_MEDIUM_UNSPECIFIED;
372 if ((flags & FLAG_RNDIS_PHYM_WIRELESS) &&
373 *phym != RNDIS_PHYSICAL_MEDIUM_WIRELESS_LAN) {
374 if (netif_msg_probe(dev))
375 dev_dbg(&intf->dev, "driver requires wireless "
376 "physical medium, but device is not.\n");
378 goto halt_fail_and_release;
380 if ((flags & FLAG_RNDIS_PHYM_NOT_WIRELESS) &&
381 *phym == RNDIS_PHYSICAL_MEDIUM_WIRELESS_LAN) {
382 if (netif_msg_probe(dev))
383 dev_dbg(&intf->dev, "driver requires non-wireless "
384 "physical medium, but device is wireless.\n");
386 goto halt_fail_and_release;
389 /* Get designated host ethernet address */
390 reply_len = ETH_ALEN;
391 retval = rndis_query(dev, intf, u.buf, OID_802_3_PERMANENT_ADDRESS,
392 48, (void **) &bp, &reply_len);
393 if (unlikely(retval< 0)) {
394 dev_err(&intf->dev, "rndis get ethaddr, %d\n", retval);
395 goto halt_fail_and_release;
397 memcpy(net->dev_addr, bp, ETH_ALEN);
399 /* set a nonzero filter to enable data transfers */
400 memset(u.set, 0, sizeof *u.set);
401 u.set->msg_type = RNDIS_MSG_SET;
402 u.set->msg_len = ccpu2(4 + sizeof *u.set);
403 u.set->oid = OID_GEN_CURRENT_PACKET_FILTER;
404 u.set->len = ccpu2(4);
405 u.set->offset = ccpu2((sizeof *u.set) - 8);
406 *(__le32 *)(u.buf + sizeof *u.set) = RNDIS_DEFAULT_FILTER;
408 retval = rndis_command(dev, u.header);
409 if (unlikely(retval < 0)) {
410 dev_err(&intf->dev, "rndis set packet filter, %d\n", retval);
411 goto halt_fail_and_release;
419 halt_fail_and_release:
420 memset(u.halt, 0, sizeof *u.halt);
421 u.halt->msg_type = RNDIS_MSG_HALT;
422 u.halt->msg_len = ccpu2(sizeof *u.halt);
423 (void) rndis_command(dev, (void *)u.halt);
425 usb_set_intfdata(info->data, NULL);
426 usb_driver_release_interface(driver_of(intf), info->data);
432 EXPORT_SYMBOL_GPL(generic_rndis_bind);
434 static int rndis_bind(struct usbnet *dev, struct usb_interface *intf)
436 return generic_rndis_bind(dev, intf, FLAG_RNDIS_PHYM_NOT_WIRELESS);
439 void rndis_unbind(struct usbnet *dev, struct usb_interface *intf)
441 struct rndis_halt *halt;
443 /* try to clear any rndis state/activity (no i/o from stack!) */
444 halt = kzalloc(CONTROL_BUFFER_SIZE, GFP_KERNEL);
446 halt->msg_type = RNDIS_MSG_HALT;
447 halt->msg_len = ccpu2(sizeof *halt);
448 (void) rndis_command(dev, (void *)halt);
452 usbnet_cdc_unbind(dev, intf);
454 EXPORT_SYMBOL_GPL(rndis_unbind);
457 * DATA -- host must not write zlps
459 int rndis_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
461 /* peripheral may have batched packets to us... */
462 while (likely(skb->len)) {
463 struct rndis_data_hdr *hdr = (void *)skb->data;
464 struct sk_buff *skb2;
465 u32 msg_len, data_offset, data_len;
467 msg_len = le32_to_cpu(hdr->msg_len);
468 data_offset = le32_to_cpu(hdr->data_offset);
469 data_len = le32_to_cpu(hdr->data_len);
471 /* don't choke if we see oob, per-packet data, etc */
472 if (unlikely(hdr->msg_type != RNDIS_MSG_PACKET
473 || skb->len < msg_len
474 || (data_offset + data_len + 8) > msg_len)) {
475 dev->stats.rx_frame_errors++;
476 devdbg(dev, "bad rndis message %d/%d/%d/%d, len %d",
477 le32_to_cpu(hdr->msg_type),
478 msg_len, data_offset, data_len, skb->len);
481 skb_pull(skb, 8 + data_offset);
483 /* at most one packet left? */
484 if (likely((data_len - skb->len) <= sizeof *hdr)) {
485 skb_trim(skb, data_len);
489 /* try to return all the packets in the batch */
490 skb2 = skb_clone(skb, GFP_ATOMIC);
493 skb_pull(skb, msg_len - sizeof *hdr);
494 skb_trim(skb2, data_len);
495 usbnet_skb_return(dev, skb2);
498 /* caller will usbnet_skb_return the remaining packet */
501 EXPORT_SYMBOL_GPL(rndis_rx_fixup);
504 rndis_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
506 struct rndis_data_hdr *hdr;
507 struct sk_buff *skb2;
508 unsigned len = skb->len;
510 if (likely(!skb_cloned(skb))) {
511 int room = skb_headroom(skb);
513 /* enough head room as-is? */
514 if (unlikely((sizeof *hdr) <= room))
517 /* enough room, but needs to be readjusted? */
518 room += skb_tailroom(skb);
519 if (likely((sizeof *hdr) <= room)) {
520 skb->data = memmove(skb->head + sizeof *hdr,
522 skb_set_tail_pointer(skb, len);
527 /* create a new skb, with the correct size (and tailpad) */
528 skb2 = skb_copy_expand(skb, sizeof *hdr, 1, flags);
529 dev_kfree_skb_any(skb);
534 /* fill out the RNDIS header. we won't bother trying to batch
535 * packets; Linux minimizes wasted bandwidth through tx queues.
538 hdr = (void *) __skb_push(skb, sizeof *hdr);
539 memset(hdr, 0, sizeof *hdr);
540 hdr->msg_type = RNDIS_MSG_PACKET;
541 hdr->msg_len = cpu_to_le32(skb->len);
542 hdr->data_offset = ccpu2(sizeof(*hdr) - 8);
543 hdr->data_len = cpu_to_le32(len);
545 /* FIXME make the last packet always be short ... */
548 EXPORT_SYMBOL_GPL(rndis_tx_fixup);
551 static const struct driver_info rndis_info = {
552 .description = "RNDIS device",
553 .flags = FLAG_ETHER | FLAG_FRAMING_RN | FLAG_NO_SETINT,
555 .unbind = rndis_unbind,
556 .status = rndis_status,
557 .rx_fixup = rndis_rx_fixup,
558 .tx_fixup = rndis_tx_fixup,
564 /*-------------------------------------------------------------------------*/
566 static const struct usb_device_id products [] = {
568 /* RNDIS is MSFT's un-official variant of CDC ACM */
569 USB_INTERFACE_INFO(USB_CLASS_COMM, 2 /* ACM */, 0x0ff),
570 .driver_info = (unsigned long) &rndis_info,
572 /* "ActiveSync" is an undocumented variant of RNDIS, used in WM5 */
573 USB_INTERFACE_INFO(USB_CLASS_MISC, 1, 1),
574 .driver_info = (unsigned long) &rndis_info,
578 MODULE_DEVICE_TABLE(usb, products);
580 static struct usb_driver rndis_driver = {
581 .name = "rndis_host",
582 .id_table = products,
583 .probe = usbnet_probe,
584 .disconnect = usbnet_disconnect,
585 .suspend = usbnet_suspend,
586 .resume = usbnet_resume,
589 static int __init rndis_init(void)
591 return usb_register(&rndis_driver);
593 module_init(rndis_init);
595 static void __exit rndis_exit(void)
597 usb_deregister(&rndis_driver);
599 module_exit(rndis_exit);
601 MODULE_AUTHOR("David Brownell");
602 MODULE_DESCRIPTION("USB Host side RNDIS driver");
603 MODULE_LICENSE("GPL");