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, int buflen)
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,
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 = cpu_to_le32(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, __le32 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 = cpu_to_le32(20);
242 retval = rndis_command(dev, u.header, CONTROL_BUFFER_SIZE);
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",
269 /* same as usbnet_netdev_ops but MTU change not allowed */
270 static const struct net_device_ops rndis_netdev_ops = {
271 .ndo_open = usbnet_open,
272 .ndo_stop = usbnet_stop,
273 .ndo_start_xmit = usbnet_start_xmit,
274 .ndo_tx_timeout = usbnet_tx_timeout,
275 .ndo_set_mac_address = eth_mac_addr,
276 .ndo_validate_addr = eth_validate_addr,
280 generic_rndis_bind(struct usbnet *dev, struct usb_interface *intf, int flags)
283 struct net_device *net = dev->net;
284 struct cdc_state *info = (void *) &dev->data;
287 struct rndis_msg_hdr *header;
288 struct rndis_init *init;
289 struct rndis_init_c *init_c;
290 struct rndis_query *get;
291 struct rndis_query_c *get_c;
292 struct rndis_set *set;
293 struct rndis_set_c *set_c;
294 struct rndis_halt *halt;
297 __le32 phym_unspec, *phym;
301 /* we can't rely on i/o from stack working, or stack allocation */
302 u.buf = kmalloc(CONTROL_BUFFER_SIZE, GFP_KERNEL);
305 retval = usbnet_generic_cdc_bind(dev, intf);
309 u.init->msg_type = RNDIS_MSG_INIT;
310 u.init->msg_len = cpu_to_le32(sizeof *u.init);
311 u.init->major_version = cpu_to_le32(1);
312 u.init->minor_version = cpu_to_le32(0);
314 /* max transfer (in spec) is 0x4000 at full speed, but for
315 * TX we'll stick to one Ethernet packet plus RNDIS framing.
316 * For RX we handle drivers that zero-pad to end-of-packet.
317 * Don't let userspace change these settings.
319 * NOTE: there still seems to be wierdness here, as if we need
320 * to do some more things to make sure WinCE targets accept this.
321 * They default to jumbograms of 8KB or 16KB, which is absurd
322 * for such low data rates and which is also more than Linux
323 * can usually expect to allocate for SKB data...
325 net->hard_header_len += sizeof (struct rndis_data_hdr);
326 dev->hard_mtu = net->mtu + net->hard_header_len;
328 dev->maxpacket = usb_maxpacket(dev->udev, dev->out, 1);
329 if (dev->maxpacket == 0) {
330 if (netif_msg_probe(dev))
331 dev_dbg(&intf->dev, "dev->maxpacket can't be 0\n");
333 goto fail_and_release;
336 dev->rx_urb_size = dev->hard_mtu + (dev->maxpacket + 1);
337 dev->rx_urb_size &= ~(dev->maxpacket - 1);
338 u.init->max_transfer_size = cpu_to_le32(dev->rx_urb_size);
340 net->netdev_ops = &rndis_netdev_ops;
342 retval = rndis_command(dev, u.header, CONTROL_BUFFER_SIZE);
343 if (unlikely(retval < 0)) {
344 /* it might not even be an RNDIS device!! */
345 dev_err(&intf->dev, "RNDIS init failed, %d\n", retval);
346 goto fail_and_release;
348 tmp = le32_to_cpu(u.init_c->max_transfer_size);
349 if (tmp < dev->hard_mtu) {
350 if (tmp <= net->hard_header_len) {
352 "dev can't take %u byte packets (max %u)\n",
355 goto halt_fail_and_release;
358 net->mtu = dev->hard_mtu - net->hard_header_len;
360 "dev can't take %u byte packets (max %u), "
361 "adjusting MTU to %u\n",
362 dev->hard_mtu, tmp, net->mtu);
365 /* REVISIT: peripheral "alignment" request is ignored ... */
367 "hard mtu %u (%u from dev), rx buflen %Zu, align %d\n",
368 dev->hard_mtu, tmp, dev->rx_urb_size,
369 1 << le32_to_cpu(u.init_c->packet_alignment));
371 /* module has some device initialization code needs to be done right
372 * after RNDIS_INIT */
373 if (dev->driver_info->early_init &&
374 dev->driver_info->early_init(dev) != 0)
375 goto halt_fail_and_release;
377 /* Check physical medium */
379 reply_len = sizeof *phym;
380 retval = rndis_query(dev, intf, u.buf, OID_GEN_PHYSICAL_MEDIUM,
381 0, (void **) &phym, &reply_len);
382 if (retval != 0 || !phym) {
383 /* OID is optional so don't fail here. */
384 phym_unspec = RNDIS_PHYSICAL_MEDIUM_UNSPECIFIED;
387 if ((flags & FLAG_RNDIS_PHYM_WIRELESS) &&
388 *phym != RNDIS_PHYSICAL_MEDIUM_WIRELESS_LAN) {
389 if (netif_msg_probe(dev))
390 dev_dbg(&intf->dev, "driver requires wireless "
391 "physical medium, but device is not.\n");
393 goto halt_fail_and_release;
395 if ((flags & FLAG_RNDIS_PHYM_NOT_WIRELESS) &&
396 *phym == RNDIS_PHYSICAL_MEDIUM_WIRELESS_LAN) {
397 if (netif_msg_probe(dev))
398 dev_dbg(&intf->dev, "driver requires non-wireless "
399 "physical medium, but device is wireless.\n");
401 goto halt_fail_and_release;
404 /* Get designated host ethernet address */
405 reply_len = ETH_ALEN;
406 retval = rndis_query(dev, intf, u.buf, OID_802_3_PERMANENT_ADDRESS,
407 48, (void **) &bp, &reply_len);
408 if (unlikely(retval< 0)) {
409 dev_err(&intf->dev, "rndis get ethaddr, %d\n", retval);
410 goto halt_fail_and_release;
412 memcpy(net->dev_addr, bp, ETH_ALEN);
414 /* set a nonzero filter to enable data transfers */
415 memset(u.set, 0, sizeof *u.set);
416 u.set->msg_type = RNDIS_MSG_SET;
417 u.set->msg_len = cpu_to_le32(4 + sizeof *u.set);
418 u.set->oid = OID_GEN_CURRENT_PACKET_FILTER;
419 u.set->len = cpu_to_le32(4);
420 u.set->offset = cpu_to_le32((sizeof *u.set) - 8);
421 *(__le32 *)(u.buf + sizeof *u.set) = RNDIS_DEFAULT_FILTER;
423 retval = rndis_command(dev, u.header, CONTROL_BUFFER_SIZE);
424 if (unlikely(retval < 0)) {
425 dev_err(&intf->dev, "rndis set packet filter, %d\n", retval);
426 goto halt_fail_and_release;
434 halt_fail_and_release:
435 memset(u.halt, 0, sizeof *u.halt);
436 u.halt->msg_type = RNDIS_MSG_HALT;
437 u.halt->msg_len = cpu_to_le32(sizeof *u.halt);
438 (void) rndis_command(dev, (void *)u.halt, CONTROL_BUFFER_SIZE);
440 usb_set_intfdata(info->data, NULL);
441 usb_driver_release_interface(driver_of(intf), info->data);
447 EXPORT_SYMBOL_GPL(generic_rndis_bind);
449 static int rndis_bind(struct usbnet *dev, struct usb_interface *intf)
451 return generic_rndis_bind(dev, intf, FLAG_RNDIS_PHYM_NOT_WIRELESS);
454 void rndis_unbind(struct usbnet *dev, struct usb_interface *intf)
456 struct rndis_halt *halt;
458 /* try to clear any rndis state/activity (no i/o from stack!) */
459 halt = kzalloc(CONTROL_BUFFER_SIZE, GFP_KERNEL);
461 halt->msg_type = RNDIS_MSG_HALT;
462 halt->msg_len = cpu_to_le32(sizeof *halt);
463 (void) rndis_command(dev, (void *)halt, CONTROL_BUFFER_SIZE);
467 usbnet_cdc_unbind(dev, intf);
469 EXPORT_SYMBOL_GPL(rndis_unbind);
472 * DATA -- host must not write zlps
474 int rndis_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
476 /* peripheral may have batched packets to us... */
477 while (likely(skb->len)) {
478 struct rndis_data_hdr *hdr = (void *)skb->data;
479 struct sk_buff *skb2;
480 u32 msg_len, data_offset, data_len;
482 msg_len = le32_to_cpu(hdr->msg_len);
483 data_offset = le32_to_cpu(hdr->data_offset);
484 data_len = le32_to_cpu(hdr->data_len);
486 /* don't choke if we see oob, per-packet data, etc */
487 if (unlikely(hdr->msg_type != RNDIS_MSG_PACKET
488 || skb->len < msg_len
489 || (data_offset + data_len + 8) > msg_len)) {
490 dev->stats.rx_frame_errors++;
491 devdbg(dev, "bad rndis message %d/%d/%d/%d, len %d",
492 le32_to_cpu(hdr->msg_type),
493 msg_len, data_offset, data_len, skb->len);
496 skb_pull(skb, 8 + data_offset);
498 /* at most one packet left? */
499 if (likely((data_len - skb->len) <= sizeof *hdr)) {
500 skb_trim(skb, data_len);
504 /* try to return all the packets in the batch */
505 skb2 = skb_clone(skb, GFP_ATOMIC);
508 skb_pull(skb, msg_len - sizeof *hdr);
509 skb_trim(skb2, data_len);
510 usbnet_skb_return(dev, skb2);
513 /* caller will usbnet_skb_return the remaining packet */
516 EXPORT_SYMBOL_GPL(rndis_rx_fixup);
519 rndis_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
521 struct rndis_data_hdr *hdr;
522 struct sk_buff *skb2;
523 unsigned len = skb->len;
525 if (likely(!skb_cloned(skb))) {
526 int room = skb_headroom(skb);
528 /* enough head room as-is? */
529 if (unlikely((sizeof *hdr) <= room))
532 /* enough room, but needs to be readjusted? */
533 room += skb_tailroom(skb);
534 if (likely((sizeof *hdr) <= room)) {
535 skb->data = memmove(skb->head + sizeof *hdr,
537 skb_set_tail_pointer(skb, len);
542 /* create a new skb, with the correct size (and tailpad) */
543 skb2 = skb_copy_expand(skb, sizeof *hdr, 1, flags);
544 dev_kfree_skb_any(skb);
549 /* fill out the RNDIS header. we won't bother trying to batch
550 * packets; Linux minimizes wasted bandwidth through tx queues.
553 hdr = (void *) __skb_push(skb, sizeof *hdr);
554 memset(hdr, 0, sizeof *hdr);
555 hdr->msg_type = RNDIS_MSG_PACKET;
556 hdr->msg_len = cpu_to_le32(skb->len);
557 hdr->data_offset = cpu_to_le32(sizeof(*hdr) - 8);
558 hdr->data_len = cpu_to_le32(len);
560 /* FIXME make the last packet always be short ... */
563 EXPORT_SYMBOL_GPL(rndis_tx_fixup);
566 static const struct driver_info rndis_info = {
567 .description = "RNDIS device",
568 .flags = FLAG_ETHER | FLAG_FRAMING_RN | FLAG_NO_SETINT,
570 .unbind = rndis_unbind,
571 .status = rndis_status,
572 .rx_fixup = rndis_rx_fixup,
573 .tx_fixup = rndis_tx_fixup,
576 /*-------------------------------------------------------------------------*/
578 static const struct usb_device_id products [] = {
580 /* RNDIS is MSFT's un-official variant of CDC ACM */
581 USB_INTERFACE_INFO(USB_CLASS_COMM, 2 /* ACM */, 0x0ff),
582 .driver_info = (unsigned long) &rndis_info,
584 /* "ActiveSync" is an undocumented variant of RNDIS, used in WM5 */
585 USB_INTERFACE_INFO(USB_CLASS_MISC, 1, 1),
586 .driver_info = (unsigned long) &rndis_info,
588 /* RNDIS for tethering */
589 USB_INTERFACE_INFO(USB_CLASS_WIRELESS_CONTROLLER, 1, 3),
590 .driver_info = (unsigned long) &rndis_info,
594 MODULE_DEVICE_TABLE(usb, products);
596 static struct usb_driver rndis_driver = {
597 .name = "rndis_host",
598 .id_table = products,
599 .probe = usbnet_probe,
600 .disconnect = usbnet_disconnect,
601 .suspend = usbnet_suspend,
602 .resume = usbnet_resume,
605 static int __init rndis_init(void)
607 return usb_register(&rndis_driver);
609 module_init(rndis_init);
611 static void __exit rndis_exit(void)
613 usb_deregister(&rndis_driver);
615 module_exit(rndis_exit);
617 MODULE_AUTHOR("David Brownell");
618 MODULE_DESCRIPTION("USB Host side RNDIS driver");
619 MODULE_LICENSE("GPL");