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/slab.h>
26 #include <linux/mii.h>
27 #include <linux/usb.h>
28 #include <linux/usb/cdc.h>
29 #include <linux/usb/usbnet.h>
30 #include <linux/usb/rndis_host.h>
34 * RNDIS is NDIS remoted over USB. It's a MSFT variant of CDC ACM ... of
35 * course ACM was intended for modems, not Ethernet links! USB's standard
36 * for Ethernet links is "CDC Ethernet", which is significantly simpler.
38 * NOTE that Microsoft's "RNDIS 1.0" specification is incomplete. Issues
40 * - Power management in particular relies on information that's scattered
41 * through other documentation, and which is incomplete or incorrect even
43 * - There are various undocumented protocol requirements, such as the
44 * need to send unused garbage in control-OUT messages.
45 * - In some cases, MS-Windows will emit undocumented requests; this
46 * matters more to peripheral implementations than host ones.
48 * Moreover there's a no-open-specs variant of RNDIS called "ActiveSync".
50 * For these reasons and others, ** USE OF RNDIS IS STRONGLY DISCOURAGED ** in
51 * favor of such non-proprietary alternatives as CDC Ethernet or the newer (and
52 * currently rare) "Ethernet Emulation Model" (EEM).
56 * RNDIS notifications from device: command completion; "reverse"
59 void rndis_status(struct usbnet
*dev
, struct urb
*urb
)
61 netdev_dbg(dev
->net
, "rndis status urb, len %d stat %d\n",
62 urb
->actual_length
, urb
->status
);
63 // FIXME for keepalives, respond immediately (asynchronously)
64 // if not an RNDIS status, do like cdc_status(dev,urb) does
66 EXPORT_SYMBOL_GPL(rndis_status
);
69 * RNDIS indicate messages.
71 static void rndis_msg_indicate(struct usbnet
*dev
, struct rndis_indicate
*msg
,
74 struct cdc_state
*info
= (void *)&dev
->data
;
75 struct device
*udev
= &info
->control
->dev
;
77 if (dev
->driver_info
->indication
) {
78 dev
->driver_info
->indication(dev
, msg
, buflen
);
80 switch (msg
->status
) {
81 case RNDIS_STATUS_MEDIA_CONNECT
:
82 dev_info(udev
, "rndis media connect\n");
84 case RNDIS_STATUS_MEDIA_DISCONNECT
:
85 dev_info(udev
, "rndis media disconnect\n");
88 dev_info(udev
, "rndis indication: 0x%08x\n",
89 le32_to_cpu(msg
->status
));
95 * RPC done RNDIS-style. Caller guarantees:
96 * - message is properly byteswapped
97 * - there's no other request pending
98 * - buf can hold up to 1KB response (required by RNDIS spec)
99 * On return, the first few entries are already byteswapped.
101 * Call context is likely probe(), before interface name is known,
102 * which is why we won't try to use it in the diagnostics.
104 int rndis_command(struct usbnet
*dev
, struct rndis_msg_hdr
*buf
, int buflen
)
106 struct cdc_state
*info
= (void *) &dev
->data
;
111 u32 xid
= 0, msg_len
, request_id
;
113 /* REVISIT when this gets called from contexts other than probe() or
114 * disconnect(): either serialize, or dispatch responses on xid
117 /* Issue the request; xid is unique, don't bother byteswapping it */
118 if (likely(buf
->msg_type
!= RNDIS_MSG_HALT
&&
119 buf
->msg_type
!= RNDIS_MSG_RESET
)) {
123 buf
->request_id
= (__force __le32
) xid
;
125 master_ifnum
= info
->control
->cur_altsetting
->desc
.bInterfaceNumber
;
126 retval
= usb_control_msg(dev
->udev
,
127 usb_sndctrlpipe(dev
->udev
, 0),
128 USB_CDC_SEND_ENCAPSULATED_COMMAND
,
129 USB_TYPE_CLASS
| USB_RECIP_INTERFACE
,
131 buf
, le32_to_cpu(buf
->msg_len
),
132 RNDIS_CONTROL_TIMEOUT_MS
);
133 if (unlikely(retval
< 0 || xid
== 0))
136 // FIXME Seems like some devices discard responses when
137 // we time out and cancel our "get response" requests...
138 // so, this is fragile. Probably need to poll for status.
140 /* ignore status endpoint, just poll the control channel;
141 * the request probably completed immediately
143 rsp
= buf
->msg_type
| RNDIS_MSG_COMPLETION
;
144 for (count
= 0; count
< 10; count
++) {
145 memset(buf
, 0, CONTROL_BUFFER_SIZE
);
146 retval
= usb_control_msg(dev
->udev
,
147 usb_rcvctrlpipe(dev
->udev
, 0),
148 USB_CDC_GET_ENCAPSULATED_RESPONSE
,
149 USB_DIR_IN
| USB_TYPE_CLASS
| USB_RECIP_INTERFACE
,
152 RNDIS_CONTROL_TIMEOUT_MS
);
153 if (likely(retval
>= 8)) {
154 msg_len
= le32_to_cpu(buf
->msg_len
);
155 request_id
= (__force u32
) buf
->request_id
;
156 if (likely(buf
->msg_type
== rsp
)) {
157 if (likely(request_id
== xid
)) {
158 if (unlikely(rsp
== RNDIS_MSG_RESET_C
))
160 if (likely(RNDIS_STATUS_SUCCESS
163 dev_dbg(&info
->control
->dev
,
164 "rndis reply status %08x\n",
165 le32_to_cpu(buf
->status
));
168 dev_dbg(&info
->control
->dev
,
169 "rndis reply id %d expected %d\n",
171 /* then likely retry */
172 } else switch (buf
->msg_type
) {
173 case RNDIS_MSG_INDICATE
: /* fault/event */
174 rndis_msg_indicate(dev
, (void *)buf
, buflen
);
177 case RNDIS_MSG_KEEPALIVE
: { /* ping */
178 struct rndis_keepalive_c
*msg
= (void *)buf
;
180 msg
->msg_type
= RNDIS_MSG_KEEPALIVE_C
;
181 msg
->msg_len
= cpu_to_le32(sizeof *msg
);
182 msg
->status
= RNDIS_STATUS_SUCCESS
;
183 retval
= usb_control_msg(dev
->udev
,
184 usb_sndctrlpipe(dev
->udev
, 0),
185 USB_CDC_SEND_ENCAPSULATED_COMMAND
,
186 USB_TYPE_CLASS
| USB_RECIP_INTERFACE
,
189 RNDIS_CONTROL_TIMEOUT_MS
);
190 if (unlikely(retval
< 0))
191 dev_dbg(&info
->control
->dev
,
192 "rndis keepalive err %d\n",
197 dev_dbg(&info
->control
->dev
,
198 "unexpected rndis msg %08x len %d\n",
199 le32_to_cpu(buf
->msg_type
), msg_len
);
202 /* device probably issued a protocol stall; ignore */
203 dev_dbg(&info
->control
->dev
,
204 "rndis response error, code %d\n", retval
);
208 dev_dbg(&info
->control
->dev
, "rndis response timeout\n");
211 EXPORT_SYMBOL_GPL(rndis_command
);
216 * Performs a query for @oid along with 0 or more bytes of payload as
217 * specified by @in_len. If @reply_len is not set to -1 then the reply
218 * length is checked against this value, resulting in an error if it
221 * NOTE: Adding a payload exactly or greater than the size of the expected
222 * response payload is an evident requirement MSFT added for ActiveSync.
224 * The only exception is for OIDs that return a variably sized response,
225 * in which case no payload should be added. This undocumented (and
226 * nonsensical!) issue was found by sniffing protocol requests from the
227 * ActiveSync 4.1 Windows driver.
229 static int rndis_query(struct usbnet
*dev
, struct usb_interface
*intf
,
230 void *buf
, __le32 oid
, u32 in_len
,
231 void **reply
, int *reply_len
)
236 struct rndis_msg_hdr
*header
;
237 struct rndis_query
*get
;
238 struct rndis_query_c
*get_c
;
244 memset(u
.get
, 0, sizeof *u
.get
+ in_len
);
245 u
.get
->msg_type
= RNDIS_MSG_QUERY
;
246 u
.get
->msg_len
= cpu_to_le32(sizeof *u
.get
+ in_len
);
248 u
.get
->len
= cpu_to_le32(in_len
);
249 u
.get
->offset
= cpu_to_le32(20);
251 retval
= rndis_command(dev
, u
.header
, CONTROL_BUFFER_SIZE
);
252 if (unlikely(retval
< 0)) {
253 dev_err(&intf
->dev
, "RNDIS_MSG_QUERY(0x%08x) failed, %d\n",
258 off
= le32_to_cpu(u
.get_c
->offset
);
259 len
= le32_to_cpu(u
.get_c
->len
);
260 if (unlikely((8 + off
+ len
) > CONTROL_BUFFER_SIZE
))
263 if (*reply_len
!= -1 && len
!= *reply_len
)
266 *reply
= (unsigned char *) &u
.get_c
->request_id
+ off
;
272 dev_err(&intf
->dev
, "RNDIS_MSG_QUERY(0x%08x) "
273 "invalid response - off %d len %d\n",
278 /* same as usbnet_netdev_ops but MTU change not allowed */
279 static const struct net_device_ops rndis_netdev_ops
= {
280 .ndo_open
= usbnet_open
,
281 .ndo_stop
= usbnet_stop
,
282 .ndo_start_xmit
= usbnet_start_xmit
,
283 .ndo_tx_timeout
= usbnet_tx_timeout
,
284 .ndo_set_mac_address
= eth_mac_addr
,
285 .ndo_validate_addr
= eth_validate_addr
,
289 generic_rndis_bind(struct usbnet
*dev
, struct usb_interface
*intf
, int flags
)
292 struct net_device
*net
= dev
->net
;
293 struct cdc_state
*info
= (void *) &dev
->data
;
296 struct rndis_msg_hdr
*header
;
297 struct rndis_init
*init
;
298 struct rndis_init_c
*init_c
;
299 struct rndis_query
*get
;
300 struct rndis_query_c
*get_c
;
301 struct rndis_set
*set
;
302 struct rndis_set_c
*set_c
;
303 struct rndis_halt
*halt
;
306 __le32 phym_unspec
, *phym
;
310 /* we can't rely on i/o from stack working, or stack allocation */
311 u
.buf
= kmalloc(CONTROL_BUFFER_SIZE
, GFP_KERNEL
);
314 retval
= usbnet_generic_cdc_bind(dev
, intf
);
318 u
.init
->msg_type
= RNDIS_MSG_INIT
;
319 u
.init
->msg_len
= cpu_to_le32(sizeof *u
.init
);
320 u
.init
->major_version
= cpu_to_le32(1);
321 u
.init
->minor_version
= cpu_to_le32(0);
323 /* max transfer (in spec) is 0x4000 at full speed, but for
324 * TX we'll stick to one Ethernet packet plus RNDIS framing.
325 * For RX we handle drivers that zero-pad to end-of-packet.
326 * Don't let userspace change these settings.
328 * NOTE: there still seems to be wierdness here, as if we need
329 * to do some more things to make sure WinCE targets accept this.
330 * They default to jumbograms of 8KB or 16KB, which is absurd
331 * for such low data rates and which is also more than Linux
332 * can usually expect to allocate for SKB data...
334 net
->hard_header_len
+= sizeof (struct rndis_data_hdr
);
335 dev
->hard_mtu
= net
->mtu
+ net
->hard_header_len
;
337 dev
->maxpacket
= usb_maxpacket(dev
->udev
, dev
->out
, 1);
338 if (dev
->maxpacket
== 0) {
339 netif_dbg(dev
, probe
, dev
->net
,
340 "dev->maxpacket can't be 0\n");
342 goto fail_and_release
;
345 dev
->rx_urb_size
= dev
->hard_mtu
+ (dev
->maxpacket
+ 1);
346 dev
->rx_urb_size
&= ~(dev
->maxpacket
- 1);
347 u
.init
->max_transfer_size
= cpu_to_le32(dev
->rx_urb_size
);
349 net
->netdev_ops
= &rndis_netdev_ops
;
351 retval
= rndis_command(dev
, u
.header
, CONTROL_BUFFER_SIZE
);
352 if (unlikely(retval
< 0)) {
353 /* it might not even be an RNDIS device!! */
354 dev_err(&intf
->dev
, "RNDIS init failed, %d\n", retval
);
355 goto fail_and_release
;
357 tmp
= le32_to_cpu(u
.init_c
->max_transfer_size
);
358 if (tmp
< dev
->hard_mtu
) {
359 if (tmp
<= net
->hard_header_len
) {
361 "dev can't take %u byte packets (max %u)\n",
364 goto halt_fail_and_release
;
367 "dev can't take %u byte packets (max %u), "
368 "adjusting MTU to %u\n",
369 dev
->hard_mtu
, tmp
, tmp
- net
->hard_header_len
);
371 net
->mtu
= dev
->hard_mtu
- net
->hard_header_len
;
374 /* REVISIT: peripheral "alignment" request is ignored ... */
376 "hard mtu %u (%u from dev), rx buflen %Zu, align %d\n",
377 dev
->hard_mtu
, tmp
, dev
->rx_urb_size
,
378 1 << le32_to_cpu(u
.init_c
->packet_alignment
));
380 /* module has some device initialization code needs to be done right
381 * after RNDIS_INIT */
382 if (dev
->driver_info
->early_init
&&
383 dev
->driver_info
->early_init(dev
) != 0)
384 goto halt_fail_and_release
;
386 /* Check physical medium */
388 reply_len
= sizeof *phym
;
389 retval
= rndis_query(dev
, intf
, u
.buf
, OID_GEN_PHYSICAL_MEDIUM
,
390 0, (void **) &phym
, &reply_len
);
391 if (retval
!= 0 || !phym
) {
392 /* OID is optional so don't fail here. */
393 phym_unspec
= RNDIS_PHYSICAL_MEDIUM_UNSPECIFIED
;
396 if ((flags
& FLAG_RNDIS_PHYM_WIRELESS
) &&
397 *phym
!= RNDIS_PHYSICAL_MEDIUM_WIRELESS_LAN
) {
398 netif_dbg(dev
, probe
, dev
->net
,
399 "driver requires wireless physical medium, but device is not\n");
401 goto halt_fail_and_release
;
403 if ((flags
& FLAG_RNDIS_PHYM_NOT_WIRELESS
) &&
404 *phym
== RNDIS_PHYSICAL_MEDIUM_WIRELESS_LAN
) {
405 netif_dbg(dev
, probe
, dev
->net
,
406 "driver requires non-wireless physical medium, but device is wireless.\n");
408 goto halt_fail_and_release
;
411 /* Get designated host ethernet address */
412 reply_len
= ETH_ALEN
;
413 retval
= rndis_query(dev
, intf
, u
.buf
, OID_802_3_PERMANENT_ADDRESS
,
414 48, (void **) &bp
, &reply_len
);
415 if (unlikely(retval
< 0)) {
416 dev_err(&intf
->dev
, "rndis get ethaddr, %d\n", retval
);
417 goto halt_fail_and_release
;
419 memcpy(net
->dev_addr
, bp
, ETH_ALEN
);
420 memcpy(net
->perm_addr
, bp
, ETH_ALEN
);
422 /* set a nonzero filter to enable data transfers */
423 memset(u
.set
, 0, sizeof *u
.set
);
424 u
.set
->msg_type
= RNDIS_MSG_SET
;
425 u
.set
->msg_len
= cpu_to_le32(4 + sizeof *u
.set
);
426 u
.set
->oid
= OID_GEN_CURRENT_PACKET_FILTER
;
427 u
.set
->len
= cpu_to_le32(4);
428 u
.set
->offset
= cpu_to_le32((sizeof *u
.set
) - 8);
429 *(__le32
*)(u
.buf
+ sizeof *u
.set
) = RNDIS_DEFAULT_FILTER
;
431 retval
= rndis_command(dev
, u
.header
, CONTROL_BUFFER_SIZE
);
432 if (unlikely(retval
< 0)) {
433 dev_err(&intf
->dev
, "rndis set packet filter, %d\n", retval
);
434 goto halt_fail_and_release
;
442 halt_fail_and_release
:
443 memset(u
.halt
, 0, sizeof *u
.halt
);
444 u
.halt
->msg_type
= RNDIS_MSG_HALT
;
445 u
.halt
->msg_len
= cpu_to_le32(sizeof *u
.halt
);
446 (void) rndis_command(dev
, (void *)u
.halt
, CONTROL_BUFFER_SIZE
);
448 usb_set_intfdata(info
->data
, NULL
);
449 usb_driver_release_interface(driver_of(intf
), info
->data
);
455 EXPORT_SYMBOL_GPL(generic_rndis_bind
);
457 static int rndis_bind(struct usbnet
*dev
, struct usb_interface
*intf
)
459 return generic_rndis_bind(dev
, intf
, FLAG_RNDIS_PHYM_NOT_WIRELESS
);
462 void rndis_unbind(struct usbnet
*dev
, struct usb_interface
*intf
)
464 struct rndis_halt
*halt
;
466 /* try to clear any rndis state/activity (no i/o from stack!) */
467 halt
= kzalloc(CONTROL_BUFFER_SIZE
, GFP_KERNEL
);
469 halt
->msg_type
= RNDIS_MSG_HALT
;
470 halt
->msg_len
= cpu_to_le32(sizeof *halt
);
471 (void) rndis_command(dev
, (void *)halt
, CONTROL_BUFFER_SIZE
);
475 usbnet_cdc_unbind(dev
, intf
);
477 EXPORT_SYMBOL_GPL(rndis_unbind
);
480 * DATA -- host must not write zlps
482 int rndis_rx_fixup(struct usbnet
*dev
, struct sk_buff
*skb
)
484 /* peripheral may have batched packets to us... */
485 while (likely(skb
->len
)) {
486 struct rndis_data_hdr
*hdr
= (void *)skb
->data
;
487 struct sk_buff
*skb2
;
488 u32 msg_len
, data_offset
, data_len
;
490 msg_len
= le32_to_cpu(hdr
->msg_len
);
491 data_offset
= le32_to_cpu(hdr
->data_offset
);
492 data_len
= le32_to_cpu(hdr
->data_len
);
494 /* don't choke if we see oob, per-packet data, etc */
495 if (unlikely(hdr
->msg_type
!= RNDIS_MSG_PACKET
||
496 skb
->len
< msg_len
||
497 (data_offset
+ data_len
+ 8) > msg_len
)) {
498 dev
->net
->stats
.rx_frame_errors
++;
499 netdev_dbg(dev
->net
, "bad rndis message %d/%d/%d/%d, len %d\n",
500 le32_to_cpu(hdr
->msg_type
),
501 msg_len
, data_offset
, data_len
, skb
->len
);
504 skb_pull(skb
, 8 + data_offset
);
506 /* at most one packet left? */
507 if (likely((data_len
- skb
->len
) <= sizeof *hdr
)) {
508 skb_trim(skb
, data_len
);
512 /* try to return all the packets in the batch */
513 skb2
= skb_clone(skb
, GFP_ATOMIC
);
516 skb_pull(skb
, msg_len
- sizeof *hdr
);
517 skb_trim(skb2
, data_len
);
518 usbnet_skb_return(dev
, skb2
);
521 /* caller will usbnet_skb_return the remaining packet */
524 EXPORT_SYMBOL_GPL(rndis_rx_fixup
);
527 rndis_tx_fixup(struct usbnet
*dev
, struct sk_buff
*skb
, gfp_t flags
)
529 struct rndis_data_hdr
*hdr
;
530 struct sk_buff
*skb2
;
531 unsigned len
= skb
->len
;
533 if (likely(!skb_cloned(skb
))) {
534 int room
= skb_headroom(skb
);
536 /* enough head room as-is? */
537 if (unlikely((sizeof *hdr
) <= room
))
540 /* enough room, but needs to be readjusted? */
541 room
+= skb_tailroom(skb
);
542 if (likely((sizeof *hdr
) <= room
)) {
543 skb
->data
= memmove(skb
->head
+ sizeof *hdr
,
545 skb_set_tail_pointer(skb
, len
);
550 /* create a new skb, with the correct size (and tailpad) */
551 skb2
= skb_copy_expand(skb
, sizeof *hdr
, 1, flags
);
552 dev_kfree_skb_any(skb
);
557 /* fill out the RNDIS header. we won't bother trying to batch
558 * packets; Linux minimizes wasted bandwidth through tx queues.
561 hdr
= (void *) __skb_push(skb
, sizeof *hdr
);
562 memset(hdr
, 0, sizeof *hdr
);
563 hdr
->msg_type
= RNDIS_MSG_PACKET
;
564 hdr
->msg_len
= cpu_to_le32(skb
->len
);
565 hdr
->data_offset
= cpu_to_le32(sizeof(*hdr
) - 8);
566 hdr
->data_len
= cpu_to_le32(len
);
568 /* FIXME make the last packet always be short ... */
571 EXPORT_SYMBOL_GPL(rndis_tx_fixup
);
574 static const struct driver_info rndis_info
= {
575 .description
= "RNDIS device",
576 .flags
= FLAG_ETHER
| FLAG_FRAMING_RN
| FLAG_NO_SETINT
,
578 .unbind
= rndis_unbind
,
579 .status
= rndis_status
,
580 .rx_fixup
= rndis_rx_fixup
,
581 .tx_fixup
= rndis_tx_fixup
,
584 /*-------------------------------------------------------------------------*/
586 static const struct usb_device_id products
[] = {
588 /* RNDIS is MSFT's un-official variant of CDC ACM */
589 USB_INTERFACE_INFO(USB_CLASS_COMM
, 2 /* ACM */, 0x0ff),
590 .driver_info
= (unsigned long) &rndis_info
,
592 /* "ActiveSync" is an undocumented variant of RNDIS, used in WM5 */
593 USB_INTERFACE_INFO(USB_CLASS_MISC
, 1, 1),
594 .driver_info
= (unsigned long) &rndis_info
,
596 /* RNDIS for tethering */
597 USB_INTERFACE_INFO(USB_CLASS_WIRELESS_CONTROLLER
, 1, 3),
598 .driver_info
= (unsigned long) &rndis_info
,
602 MODULE_DEVICE_TABLE(usb
, products
);
604 static struct usb_driver rndis_driver
= {
605 .name
= "rndis_host",
606 .id_table
= products
,
607 .probe
= usbnet_probe
,
608 .disconnect
= usbnet_disconnect
,
609 .suspend
= usbnet_suspend
,
610 .resume
= usbnet_resume
,
613 static int __init
rndis_init(void)
615 return usb_register(&rndis_driver
);
617 module_init(rndis_init
);
619 static void __exit
rndis_exit(void)
621 usb_deregister(&rndis_driver
);
623 module_exit(rndis_exit
);
625 MODULE_AUTHOR("David Brownell");
626 MODULE_DESCRIPTION("USB Host side RNDIS driver");
627 MODULE_LICENSE("GPL");