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/event */
152 struct rndis_indicate *msg = (void *)buf;
155 switch (msg->status) {
156 case RNDIS_STATUS_MEDIA_CONNECT:
158 case RNDIS_STATUS_MEDIA_DISCONNECT:
159 dev_info(&info->control->dev,
160 "rndis media %sconnect\n",
162 if (dev->driver_info->link_change)
163 dev->driver_info->link_change(
167 dev_info(&info->control->dev,
168 "rndis indication: 0x%08x\n",
169 le32_to_cpu(msg->status));
173 case RNDIS_MSG_KEEPALIVE: { /* ping */
174 struct rndis_keepalive_c *msg = (void *)buf;
176 msg->msg_type = RNDIS_MSG_KEEPALIVE_C;
177 msg->msg_len = ccpu2(sizeof *msg);
178 msg->status = RNDIS_STATUS_SUCCESS;
179 retval = usb_control_msg(dev->udev,
180 usb_sndctrlpipe(dev->udev, 0),
181 USB_CDC_SEND_ENCAPSULATED_COMMAND,
182 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
185 RNDIS_CONTROL_TIMEOUT_MS);
186 if (unlikely(retval < 0))
187 dev_dbg(&info->control->dev,
188 "rndis keepalive err %d\n",
193 dev_dbg(&info->control->dev,
194 "unexpected rndis msg %08x len %d\n",
195 le32_to_cpu(buf->msg_type), msg_len);
198 /* device probably issued a protocol stall; ignore */
199 dev_dbg(&info->control->dev,
200 "rndis response error, code %d\n", retval);
204 dev_dbg(&info->control->dev, "rndis response timeout\n");
207 EXPORT_SYMBOL_GPL(rndis_command);
212 * Performs a query for @oid along with 0 or more bytes of payload as
213 * specified by @in_len. If @reply_len is not set to -1 then the reply
214 * length is checked against this value, resulting in an error if it
217 * NOTE: Adding a payload exactly or greater than the size of the expected
218 * response payload is an evident requirement MSFT added for ActiveSync.
220 * The only exception is for OIDs that return a variably sized response,
221 * in which case no payload should be added. This undocumented (and
222 * nonsensical!) issue was found by sniffing protocol requests from the
223 * ActiveSync 4.1 Windows driver.
225 static int rndis_query(struct usbnet *dev, struct usb_interface *intf,
226 void *buf, u32 oid, u32 in_len,
227 void **reply, int *reply_len)
232 struct rndis_msg_hdr *header;
233 struct rndis_query *get;
234 struct rndis_query_c *get_c;
240 memset(u.get, 0, sizeof *u.get + in_len);
241 u.get->msg_type = RNDIS_MSG_QUERY;
242 u.get->msg_len = cpu_to_le32(sizeof *u.get + in_len);
244 u.get->len = cpu_to_le32(in_len);
245 u.get->offset = ccpu2(20);
247 retval = rndis_command(dev, u.header);
248 if (unlikely(retval < 0)) {
249 dev_err(&intf->dev, "RNDIS_MSG_QUERY(0x%08x) failed, %d\n",
254 off = le32_to_cpu(u.get_c->offset);
255 len = le32_to_cpu(u.get_c->len);
256 if (unlikely((8 + off + len) > CONTROL_BUFFER_SIZE))
259 if (*reply_len != -1 && len != *reply_len)
262 *reply = (unsigned char *) &u.get_c->request_id + off;
268 dev_err(&intf->dev, "RNDIS_MSG_QUERY(0x%08x) "
269 "invalid response - off %d len %d\n",
275 generic_rndis_bind(struct usbnet *dev, struct usb_interface *intf, int flags)
278 struct net_device *net = dev->net;
279 struct cdc_state *info = (void *) &dev->data;
282 struct rndis_msg_hdr *header;
283 struct rndis_init *init;
284 struct rndis_init_c *init_c;
285 struct rndis_query *get;
286 struct rndis_query_c *get_c;
287 struct rndis_set *set;
288 struct rndis_set_c *set_c;
289 struct rndis_halt *halt;
295 /* we can't rely on i/o from stack working, or stack allocation */
296 u.buf = kmalloc(CONTROL_BUFFER_SIZE, GFP_KERNEL);
299 retval = usbnet_generic_cdc_bind(dev, intf);
303 u.init->msg_type = RNDIS_MSG_INIT;
304 u.init->msg_len = ccpu2(sizeof *u.init);
305 u.init->major_version = ccpu2(1);
306 u.init->minor_version = ccpu2(0);
308 /* max transfer (in spec) is 0x4000 at full speed, but for
309 * TX we'll stick to one Ethernet packet plus RNDIS framing.
310 * For RX we handle drivers that zero-pad to end-of-packet.
311 * Don't let userspace change these settings.
313 * NOTE: there still seems to be wierdness here, as if we need
314 * to do some more things to make sure WinCE targets accept this.
315 * They default to jumbograms of 8KB or 16KB, which is absurd
316 * for such low data rates and which is also more than Linux
317 * can usually expect to allocate for SKB data...
319 net->hard_header_len += sizeof (struct rndis_data_hdr);
320 dev->hard_mtu = net->mtu + net->hard_header_len;
322 dev->rx_urb_size = dev->hard_mtu + (dev->maxpacket + 1);
323 dev->rx_urb_size &= ~(dev->maxpacket - 1);
324 u.init->max_transfer_size = cpu_to_le32(dev->rx_urb_size);
326 net->change_mtu = NULL;
327 retval = rndis_command(dev, u.header);
328 if (unlikely(retval < 0)) {
329 /* it might not even be an RNDIS device!! */
330 dev_err(&intf->dev, "RNDIS init failed, %d\n", retval);
331 goto fail_and_release;
333 tmp = le32_to_cpu(u.init_c->max_transfer_size);
334 if (tmp < dev->hard_mtu) {
335 if (tmp <= net->hard_header_len) {
337 "dev can't take %u byte packets (max %u)\n",
340 goto halt_fail_and_release;
343 net->mtu = dev->hard_mtu - net->hard_header_len;
345 "dev can't take %u byte packets (max %u), "
346 "adjusting MTU to %u\n",
347 dev->hard_mtu, tmp, net->mtu);
350 /* REVISIT: peripheral "alignment" request is ignored ... */
352 "hard mtu %u (%u from dev), rx buflen %Zu, align %d\n",
353 dev->hard_mtu, tmp, dev->rx_urb_size,
354 1 << le32_to_cpu(u.init_c->packet_alignment));
356 /* module has some device initialization code needs to be done right
357 * after RNDIS_INIT */
358 if (dev->driver_info->early_init &&
359 dev->driver_info->early_init(dev) != 0)
360 goto halt_fail_and_release;
362 /* Check physical medium */
363 reply_len = sizeof *phym;
364 retval = rndis_query(dev, intf, u.buf, OID_GEN_PHYSICAL_MEDIUM,
365 0, (void **) &phym, &reply_len);
367 /* OID is optional so don't fail here. */
368 *phym = RNDIS_PHYSICAL_MEDIUM_UNSPECIFIED;
369 if ((flags & FLAG_RNDIS_PHYM_WIRELESS) &&
370 *phym != RNDIS_PHYSICAL_MEDIUM_WIRELESS_LAN) {
371 if (netif_msg_probe(dev))
372 dev_dbg(&intf->dev, "driver requires wireless "
373 "physical medium, but device is not.\n");
375 goto halt_fail_and_release;
377 if ((flags & FLAG_RNDIS_PHYM_NOT_WIRELESS) &&
378 *phym == RNDIS_PHYSICAL_MEDIUM_WIRELESS_LAN) {
379 if (netif_msg_probe(dev))
380 dev_dbg(&intf->dev, "driver requires non-wireless "
381 "physical medium, but device is wireless.\n");
383 goto halt_fail_and_release;
386 /* Get designated host ethernet address */
387 reply_len = ETH_ALEN;
388 retval = rndis_query(dev, intf, u.buf, OID_802_3_PERMANENT_ADDRESS,
389 48, (void **) &bp, &reply_len);
390 if (unlikely(retval< 0)) {
391 dev_err(&intf->dev, "rndis get ethaddr, %d\n", retval);
392 goto halt_fail_and_release;
394 memcpy(net->dev_addr, bp, ETH_ALEN);
396 /* set a nonzero filter to enable data transfers */
397 memset(u.set, 0, sizeof *u.set);
398 u.set->msg_type = RNDIS_MSG_SET;
399 u.set->msg_len = ccpu2(4 + sizeof *u.set);
400 u.set->oid = OID_GEN_CURRENT_PACKET_FILTER;
401 u.set->len = ccpu2(4);
402 u.set->offset = ccpu2((sizeof *u.set) - 8);
403 *(__le32 *)(u.buf + sizeof *u.set) = RNDIS_DEFAULT_FILTER;
405 retval = rndis_command(dev, u.header);
406 if (unlikely(retval < 0)) {
407 dev_err(&intf->dev, "rndis set packet filter, %d\n", retval);
408 goto halt_fail_and_release;
416 halt_fail_and_release:
417 memset(u.halt, 0, sizeof *u.halt);
418 u.halt->msg_type = RNDIS_MSG_HALT;
419 u.halt->msg_len = ccpu2(sizeof *u.halt);
420 (void) rndis_command(dev, (void *)u.halt);
422 usb_set_intfdata(info->data, NULL);
423 usb_driver_release_interface(driver_of(intf), info->data);
429 EXPORT_SYMBOL_GPL(generic_rndis_bind);
431 static int rndis_bind(struct usbnet *dev, struct usb_interface *intf)
433 return generic_rndis_bind(dev, intf, FLAG_RNDIS_PHYM_NOT_WIRELESS);
436 void rndis_unbind(struct usbnet *dev, struct usb_interface *intf)
438 struct rndis_halt *halt;
440 /* try to clear any rndis state/activity (no i/o from stack!) */
441 halt = kzalloc(CONTROL_BUFFER_SIZE, GFP_KERNEL);
443 halt->msg_type = RNDIS_MSG_HALT;
444 halt->msg_len = ccpu2(sizeof *halt);
445 (void) rndis_command(dev, (void *)halt);
449 usbnet_cdc_unbind(dev, intf);
451 EXPORT_SYMBOL_GPL(rndis_unbind);
454 * DATA -- host must not write zlps
456 int rndis_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
458 /* peripheral may have batched packets to us... */
459 while (likely(skb->len)) {
460 struct rndis_data_hdr *hdr = (void *)skb->data;
461 struct sk_buff *skb2;
462 u32 msg_len, data_offset, data_len;
464 msg_len = le32_to_cpu(hdr->msg_len);
465 data_offset = le32_to_cpu(hdr->data_offset);
466 data_len = le32_to_cpu(hdr->data_len);
468 /* don't choke if we see oob, per-packet data, etc */
469 if (unlikely(hdr->msg_type != RNDIS_MSG_PACKET
470 || skb->len < msg_len
471 || (data_offset + data_len + 8) > msg_len)) {
472 dev->stats.rx_frame_errors++;
473 devdbg(dev, "bad rndis message %d/%d/%d/%d, len %d",
474 le32_to_cpu(hdr->msg_type),
475 msg_len, data_offset, data_len, skb->len);
478 skb_pull(skb, 8 + data_offset);
480 /* at most one packet left? */
481 if (likely((data_len - skb->len) <= sizeof *hdr)) {
482 skb_trim(skb, data_len);
486 /* try to return all the packets in the batch */
487 skb2 = skb_clone(skb, GFP_ATOMIC);
490 skb_pull(skb, msg_len - sizeof *hdr);
491 skb_trim(skb2, data_len);
492 usbnet_skb_return(dev, skb2);
495 /* caller will usbnet_skb_return the remaining packet */
498 EXPORT_SYMBOL_GPL(rndis_rx_fixup);
501 rndis_tx_fixup(struct usbnet *dev, struct sk_buff *skb, gfp_t flags)
503 struct rndis_data_hdr *hdr;
504 struct sk_buff *skb2;
505 unsigned len = skb->len;
507 if (likely(!skb_cloned(skb))) {
508 int room = skb_headroom(skb);
510 /* enough head room as-is? */
511 if (unlikely((sizeof *hdr) <= room))
514 /* enough room, but needs to be readjusted? */
515 room += skb_tailroom(skb);
516 if (likely((sizeof *hdr) <= room)) {
517 skb->data = memmove(skb->head + sizeof *hdr,
519 skb_set_tail_pointer(skb, len);
524 /* create a new skb, with the correct size (and tailpad) */
525 skb2 = skb_copy_expand(skb, sizeof *hdr, 1, flags);
526 dev_kfree_skb_any(skb);
531 /* fill out the RNDIS header. we won't bother trying to batch
532 * packets; Linux minimizes wasted bandwidth through tx queues.
535 hdr = (void *) __skb_push(skb, sizeof *hdr);
536 memset(hdr, 0, sizeof *hdr);
537 hdr->msg_type = RNDIS_MSG_PACKET;
538 hdr->msg_len = cpu_to_le32(skb->len);
539 hdr->data_offset = ccpu2(sizeof(*hdr) - 8);
540 hdr->data_len = cpu_to_le32(len);
542 /* FIXME make the last packet always be short ... */
545 EXPORT_SYMBOL_GPL(rndis_tx_fixup);
548 static const struct driver_info rndis_info = {
549 .description = "RNDIS device",
550 .flags = FLAG_ETHER | FLAG_FRAMING_RN | FLAG_NO_SETINT,
552 .unbind = rndis_unbind,
553 .status = rndis_status,
554 .rx_fixup = rndis_rx_fixup,
555 .tx_fixup = rndis_tx_fixup,
561 /*-------------------------------------------------------------------------*/
563 static const struct usb_device_id products [] = {
565 /* RNDIS is MSFT's un-official variant of CDC ACM */
566 USB_INTERFACE_INFO(USB_CLASS_COMM, 2 /* ACM */, 0x0ff),
567 .driver_info = (unsigned long) &rndis_info,
569 /* "ActiveSync" is an undocumented variant of RNDIS, used in WM5 */
570 USB_INTERFACE_INFO(USB_CLASS_MISC, 1, 1),
571 .driver_info = (unsigned long) &rndis_info,
575 MODULE_DEVICE_TABLE(usb, products);
577 static struct usb_driver rndis_driver = {
578 .name = "rndis_host",
579 .id_table = products,
580 .probe = usbnet_probe,
581 .disconnect = usbnet_disconnect,
582 .suspend = usbnet_suspend,
583 .resume = usbnet_resume,
586 static int __init rndis_init(void)
588 return usb_register(&rndis_driver);
590 module_init(rndis_init);
592 static void __exit rndis_exit(void)
594 usb_deregister(&rndis_driver);
596 module_exit(rndis_exit);
598 MODULE_AUTHOR("David Brownell");
599 MODULE_DESCRIPTION("USB Host side RNDIS driver");
600 MODULE_LICENSE("GPL");