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");