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>
34 #include "rndis_host.h"
38 * RNDIS is NDIS remoted over USB. It's a MSFT variant of CDC ACM ... of
39 * course ACM was intended for modems, not Ethernet links! USB's standard
40 * for Ethernet links is "CDC Ethernet", which is significantly simpler.
42 * NOTE that Microsoft's "RNDIS 1.0" specification is incomplete. Issues
44 * - Power management in particular relies on information that's scattered
45 * through other documentation, and which is incomplete or incorrect even
47 * - There are various undocumented protocol requirements, such as the
48 * need to send unused garbage in control-OUT messages.
49 * - In some cases, MS-Windows will emit undocumented requests; this
50 * matters more to peripheral implementations than host ones.
52 * Moreover there's a no-open-specs variant of RNDIS called "ActiveSync".
54 * For these reasons and others, ** USE OF RNDIS IS STRONGLY DISCOURAGED ** in
55 * favor of such non-proprietary alternatives as CDC Ethernet or the newer (and
56 * currently rare) "Ethernet Emulation Model" (EEM).
60 * RNDIS notifications from device: command completion; "reverse"
63 void rndis_status(struct usbnet *dev, struct urb *urb)
65 devdbg(dev, "rndis status urb, len %d stat %d",
66 urb->actual_length, urb->status);
67 // FIXME for keepalives, respond immediately (asynchronously)
68 // if not an RNDIS status, do like cdc_status(dev,urb) does
70 EXPORT_SYMBOL_GPL(rndis_status);
73 * RPC done RNDIS-style. Caller guarantees:
74 * - message is properly byteswapped
75 * - there's no other request pending
76 * - buf can hold up to 1KB response (required by RNDIS spec)
77 * On return, the first few entries are already byteswapped.
79 * Call context is likely probe(), before interface name is known,
80 * which is why we won't try to use it in the diagnostics.
82 int rndis_command(struct usbnet *dev, struct rndis_msg_hdr *buf)
84 struct cdc_state *info = (void *) &dev->data;
89 u32 xid = 0, msg_len, request_id;
91 /* REVISIT when this gets called from contexts other than probe() or
92 * disconnect(): either serialize, or dispatch responses on xid
95 /* Issue the request; xid is unique, don't bother byteswapping it */
96 if (likely(buf->msg_type != RNDIS_MSG_HALT
97 && buf->msg_type != RNDIS_MSG_RESET)) {
101 buf->request_id = (__force __le32) xid;
103 master_ifnum = info->control->cur_altsetting->desc.bInterfaceNumber;
104 retval = usb_control_msg(dev->udev,
105 usb_sndctrlpipe(dev->udev, 0),
106 USB_CDC_SEND_ENCAPSULATED_COMMAND,
107 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
109 buf, le32_to_cpu(buf->msg_len),
110 RNDIS_CONTROL_TIMEOUT_MS);
111 if (unlikely(retval < 0 || xid == 0))
114 // FIXME Seems like some devices discard responses when
115 // we time out and cancel our "get response" requests...
116 // so, this is fragile. Probably need to poll for status.
118 /* ignore status endpoint, just poll the control channel;
119 * the request probably completed immediately
121 rsp = buf->msg_type | RNDIS_MSG_COMPLETION;
122 for (count = 0; count < 10; count++) {
123 memset(buf, 0, CONTROL_BUFFER_SIZE);
124 retval = usb_control_msg(dev->udev,
125 usb_rcvctrlpipe(dev->udev, 0),
126 USB_CDC_GET_ENCAPSULATED_RESPONSE,
127 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
129 buf, CONTROL_BUFFER_SIZE,
130 RNDIS_CONTROL_TIMEOUT_MS);
131 if (likely(retval >= 8)) {
132 msg_len = le32_to_cpu(buf->msg_len);
133 request_id = (__force u32) buf->request_id;
134 if (likely(buf->msg_type == rsp)) {
135 if (likely(request_id == xid)) {
136 if (unlikely(rsp == RNDIS_MSG_RESET_C))
138 if (likely(RNDIS_STATUS_SUCCESS
141 dev_dbg(&info->control->dev,
142 "rndis reply status %08x\n",
143 le32_to_cpu(buf->status));
146 dev_dbg(&info->control->dev,
147 "rndis reply id %d expected %d\n",
149 /* then likely retry */
150 } else switch (buf->msg_type) {
151 case RNDIS_MSG_INDICATE: { /* fault */
152 // struct rndis_indicate *msg = (void *)buf;
153 dev_info(&info->control->dev,
154 "rndis fault indication\n");
157 case RNDIS_MSG_KEEPALIVE: { /* ping */
158 struct rndis_keepalive_c *msg = (void *)buf;
160 msg->msg_type = RNDIS_MSG_KEEPALIVE_C;
161 msg->msg_len = ccpu2(sizeof *msg);
162 msg->status = RNDIS_STATUS_SUCCESS;
163 retval = usb_control_msg(dev->udev,
164 usb_sndctrlpipe(dev->udev, 0),
165 USB_CDC_SEND_ENCAPSULATED_COMMAND,
166 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
169 RNDIS_CONTROL_TIMEOUT_MS);
170 if (unlikely(retval < 0))
171 dev_dbg(&info->control->dev,
172 "rndis keepalive err %d\n",
177 dev_dbg(&info->control->dev,
178 "unexpected rndis msg %08x len %d\n",
179 le32_to_cpu(buf->msg_type), msg_len);
182 /* device probably issued a protocol stall; ignore */
183 dev_dbg(&info->control->dev,
184 "rndis response error, code %d\n", retval);
188 dev_dbg(&info->control->dev, "rndis response timeout\n");
191 EXPORT_SYMBOL_GPL(rndis_command);
196 * Performs a query for @oid along with 0 or more bytes of payload as
197 * specified by @in_len. If @reply_len is not set to -1 then the reply
198 * length is checked against this value, resulting in an error if it
201 * NOTE: Adding a payload exactly or greater than the size of the expected
202 * response payload is an evident requirement MSFT added for ActiveSync.
204 * The only exception is for OIDs that return a variably sized response,
205 * in which case no payload should be added. This undocumented (and
206 * nonsensical!) issue was found by sniffing protocol requests from the
207 * ActiveSync 4.1 Windows driver.
209 static int rndis_query(struct usbnet *dev, struct usb_interface *intf,
210 void *buf, u32 oid, u32 in_len,
211 void **reply, int *reply_len)
216 struct rndis_msg_hdr *header;
217 struct rndis_query *get;
218 struct rndis_query_c *get_c;
224 memset(u.get, 0, sizeof *u.get + in_len);
225 u.get->msg_type = RNDIS_MSG_QUERY;
226 u.get->msg_len = cpu_to_le32(sizeof *u.get + in_len);
228 u.get->len = cpu_to_le32(in_len);
229 u.get->offset = ccpu2(20);
231 retval = rndis_command(dev, u.header);
232 if (unlikely(retval < 0)) {
233 dev_err(&intf->dev, "RNDIS_MSG_QUERY(0x%08x) failed, %d\n",
238 off = le32_to_cpu(u.get_c->offset);
239 len = le32_to_cpu(u.get_c->len);
240 if (unlikely((8 + off + len) > CONTROL_BUFFER_SIZE))
243 if (*reply_len != -1 && len != *reply_len)
246 *reply = (unsigned char *) &u.get_c->request_id + off;
252 dev_err(&intf->dev, "RNDIS_MSG_QUERY(0x%08x) "
253 "invalid response - off %d len %d\n",
258 int generic_rndis_bind(struct usbnet *dev, struct usb_interface *intf)
261 struct net_device *net = dev->net;
262 struct cdc_state *info = (void *) &dev->data;
265 struct rndis_msg_hdr *header;
266 struct rndis_init *init;
267 struct rndis_init_c *init_c;
268 struct rndis_query *get;
269 struct rndis_query_c *get_c;
270 struct rndis_set *set;
271 struct rndis_set_c *set_c;
272 struct rndis_halt *halt;
278 /* we can't rely on i/o from stack working, or stack allocation */
279 u.buf = kmalloc(CONTROL_BUFFER_SIZE, GFP_KERNEL);
282 retval = usbnet_generic_cdc_bind(dev, intf);
286 u.init->msg_type = RNDIS_MSG_INIT;
287 u.init->msg_len = ccpu2(sizeof *u.init);
288 u.init->major_version = ccpu2(1);
289 u.init->minor_version = ccpu2(0);
291 /* max transfer (in spec) is 0x4000 at full speed, but for
292 * TX we'll stick to one Ethernet packet plus RNDIS framing.
293 * For RX we handle drivers that zero-pad to end-of-packet.
294 * Don't let userspace change these settings.
296 * NOTE: there still seems to be wierdness here, as if we need
297 * to do some more things to make sure WinCE targets accept this.
298 * They default to jumbograms of 8KB or 16KB, which is absurd
299 * for such low data rates and which is also more than Linux
300 * can usually expect to allocate for SKB data...
302 net->hard_header_len += sizeof (struct rndis_data_hdr);
303 dev->hard_mtu = net->mtu + net->hard_header_len;
305 dev->rx_urb_size = dev->hard_mtu + (dev->maxpacket + 1);
306 dev->rx_urb_size &= ~(dev->maxpacket - 1);
307 u.init->max_transfer_size = cpu_to_le32(dev->rx_urb_size);
309 net->change_mtu = NULL;
310 retval = rndis_command(dev, u.header);
311 if (unlikely(retval < 0)) {
312 /* it might not even be an RNDIS device!! */
313 dev_err(&intf->dev, "RNDIS init failed, %d\n", retval);
314 goto fail_and_release;
316 tmp = le32_to_cpu(u.init_c->max_transfer_size);
317 if (tmp < dev->hard_mtu) {
318 if (tmp <= net->hard_header_len) {
320 "dev can't take %u byte packets (max %u)\n",
323 goto halt_fail_and_release;
326 net->mtu = dev->hard_mtu - net->hard_header_len;
328 "dev can't take %u byte packets (max %u), "
329 "adjusting MTU to %u\n",
330 dev->hard_mtu, tmp, net->mtu);
333 /* REVISIT: peripheral "alignment" request is ignored ... */
335 "hard mtu %u (%u from dev), rx buflen %Zu, align %d\n",
336 dev->hard_mtu, tmp, dev->rx_urb_size,
337 1 << le32_to_cpu(u.init_c->packet_alignment));
339 /* module has some device initialization code needs to be done right
340 * after RNDIS_INIT */
341 if (dev->driver_info->early_init &&
342 dev->driver_info->early_init(dev) != 0)
343 goto halt_fail_and_release;
345 /* Get designated host ethernet address */
346 reply_len = ETH_ALEN;
347 retval = rndis_query(dev, intf, u.buf, OID_802_3_PERMANENT_ADDRESS,
348 48, (void **) &bp, &reply_len);
349 if (unlikely(retval< 0)) {
350 dev_err(&intf->dev, "rndis get ethaddr, %d\n", retval);
351 goto halt_fail_and_release;
353 memcpy(net->dev_addr, bp, ETH_ALEN);
355 /* set a nonzero filter to enable data transfers */
356 memset(u.set, 0, sizeof *u.set);
357 u.set->msg_type = RNDIS_MSG_SET;
358 u.set->msg_len = ccpu2(4 + sizeof *u.set);
359 u.set->oid = OID_GEN_CURRENT_PACKET_FILTER;
360 u.set->len = ccpu2(4);
361 u.set->offset = ccpu2((sizeof *u.set) - 8);
362 *(__le32 *)(u.buf + sizeof *u.set) = RNDIS_DEFAULT_FILTER;
364 retval = rndis_command(dev, u.header);
365 if (unlikely(retval < 0)) {
366 dev_err(&intf->dev, "rndis set packet filter, %d\n", retval);
367 goto halt_fail_and_release;
375 halt_fail_and_release:
376 memset(u.halt, 0, sizeof *u.halt);
377 u.halt->msg_type = RNDIS_MSG_HALT;
378 u.halt->msg_len = ccpu2(sizeof *u.halt);
379 (void) rndis_command(dev, (void *)u.halt);
381 usb_set_intfdata(info->data, NULL);
382 usb_driver_release_interface(driver_of(intf), info->data);
388 EXPORT_SYMBOL_GPL(generic_rndis_bind);
390 void rndis_unbind(struct usbnet *dev, struct usb_interface *intf)
392 struct rndis_halt *halt;
394 /* try to clear any rndis state/activity (no i/o from stack!) */
395 halt = kzalloc(CONTROL_BUFFER_SIZE, GFP_KERNEL);
397 halt->msg_type = RNDIS_MSG_HALT;
398 halt->msg_len = ccpu2(sizeof *halt);
399 (void) rndis_command(dev, (void *)halt);
403 usbnet_cdc_unbind(dev, intf);
405 EXPORT_SYMBOL_GPL(rndis_unbind);
408 * DATA -- host must not write zlps
410 int rndis_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
412 /* peripheral may have batched packets to us... */
413 while (likely(skb->len)) {
414 struct rndis_data_hdr *hdr = (void *)skb->data;
415 struct sk_buff *skb2;
416 u32 msg_len, data_offset, data_len;
418 msg_len = le32_to_cpu(hdr->msg_len);
419 data_offset = le32_to_cpu(hdr->data_offset);
420 data_len = le32_to_cpu(hdr->data_len);
422 /* don't choke if we see oob, per-packet data, etc */
423 if (unlikely(hdr->msg_type != RNDIS_MSG_PACKET
424 || skb->len < msg_len
425 || (data_offset + data_len + 8) > msg_len)) {
426 dev->stats.rx_frame_errors++;
427 devdbg(dev, "bad rndis message %d/%d/%d/%d, len %d",
428 le32_to_cpu(hdr->msg_type),
429 msg_len, data_offset, data_len, skb->len);
432 skb_pull(skb, 8 + data_offset);
434 /* at most one packet left? */
435 if (likely((data_len - skb->len) <= sizeof *hdr)) {
436 skb_trim(skb, data_len);
440 /* try to return all the packets in the batch */
441 skb2 = skb_clone(skb, GFP_ATOMIC);
444 skb_pull(skb, msg_len - sizeof *hdr);
445 skb_trim(skb2, data_len);
446 usbnet_skb_return(dev, skb2);
449 /* caller will usbnet_skb_return the remaining packet */
452 EXPORT_SYMBOL_GPL(rndis_rx_fixup);
455 rndis_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
457 struct rndis_data_hdr *hdr;
458 struct sk_buff *skb2;
459 unsigned len = skb->len;
461 if (likely(!skb_cloned(skb))) {
462 int room = skb_headroom(skb);
464 /* enough head room as-is? */
465 if (unlikely((sizeof *hdr) <= room))
468 /* enough room, but needs to be readjusted? */
469 room += skb_tailroom(skb);
470 if (likely((sizeof *hdr) <= room)) {
471 skb->data = memmove(skb->head + sizeof *hdr,
473 skb_set_tail_pointer(skb, len);
478 /* create a new skb, with the correct size (and tailpad) */
479 skb2 = skb_copy_expand(skb, sizeof *hdr, 1, flags);
480 dev_kfree_skb_any(skb);
485 /* fill out the RNDIS header. we won't bother trying to batch
486 * packets; Linux minimizes wasted bandwidth through tx queues.
489 hdr = (void *) __skb_push(skb, sizeof *hdr);
490 memset(hdr, 0, sizeof *hdr);
491 hdr->msg_type = RNDIS_MSG_PACKET;
492 hdr->msg_len = cpu_to_le32(skb->len);
493 hdr->data_offset = ccpu2(sizeof(*hdr) - 8);
494 hdr->data_len = cpu_to_le32(len);
496 /* FIXME make the last packet always be short ... */
499 EXPORT_SYMBOL_GPL(rndis_tx_fixup);
502 static const struct driver_info rndis_info = {
503 .description = "RNDIS device",
504 .flags = FLAG_ETHER | FLAG_FRAMING_RN | FLAG_NO_SETINT,
505 .bind = generic_rndis_bind,
506 .unbind = rndis_unbind,
507 .status = rndis_status,
508 .rx_fixup = rndis_rx_fixup,
509 .tx_fixup = rndis_tx_fixup,
515 /*-------------------------------------------------------------------------*/
517 static const struct usb_device_id products [] = {
519 /* RNDIS is MSFT's un-official variant of CDC ACM */
520 USB_INTERFACE_INFO(USB_CLASS_COMM, 2 /* ACM */, 0x0ff),
521 .driver_info = (unsigned long) &rndis_info,
523 /* "ActiveSync" is an undocumented variant of RNDIS, used in WM5 */
524 USB_INTERFACE_INFO(USB_CLASS_MISC, 1, 1),
525 .driver_info = (unsigned long) &rndis_info,
529 MODULE_DEVICE_TABLE(usb, products);
531 static struct usb_driver rndis_driver = {
532 .name = "rndis_host",
533 .id_table = products,
534 .probe = usbnet_probe,
535 .disconnect = usbnet_disconnect,
536 .suspend = usbnet_suspend,
537 .resume = usbnet_resume,
540 static int __init rndis_init(void)
542 return usb_register(&rndis_driver);
544 module_init(rndis_init);
546 static void __exit rndis_exit(void)
548 usb_deregister(&rndis_driver);
550 module_exit(rndis_exit);
552 MODULE_AUTHOR("David Brownell");
553 MODULE_DESCRIPTION("USB Host side RNDIS driver");
554 MODULE_LICENSE("GPL");