2 * f_rndis.c -- RNDIS link function driver
4 * Copyright (C) 2003-2005,2008 David Brownell
5 * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
6 * Copyright (C) 2008 Nokia Corporation
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 /* #define VERBOSE_DEBUG */
25 #include <linux/kernel.h>
26 #include <linux/device.h>
27 #include <linux/etherdevice.h>
29 #include <asm/atomic.h>
36 * This function is an RNDIS Ethernet port -- a Microsoft protocol that's
37 * been promoted instead of the standard CDC Ethernet. The published RNDIS
38 * spec is ambiguous, incomplete, and needlessly complex. Variants such as
39 * ActiveSync have even worse status in terms of specification.
41 * In short: it's a protocol controlled by (and for) Microsoft, not for an
42 * Open ecosystem or markets. Linux supports it *only* because Microsoft
43 * doesn't support the CDC Ethernet standard.
45 * The RNDIS data transfer model is complex, with multiple Ethernet packets
46 * per USB message, and out of band data. The control model is built around
47 * what's essentially an "RNDIS RPC" protocol. It's all wrapped in a CDC ACM
48 * (modem, not Ethernet) veneer, with those ACM descriptors being entirely
49 * useless (they're ignored). RNDIS expects to be the only function in its
50 * configuration, so it's no real help if you need composite devices; and
51 * it expects to be the first configuration too.
53 * There is a single technical advantage of RNDIS over CDC Ethernet, if you
54 * discount the fluff that its RPC can be made to deliver: it doesn't need
55 * a NOP altsetting for the data interface. That lets it work on some of the
56 * "so smart it's stupid" hardware which takes over configuration changes
57 * from the software, and adds restrictions like "no altsettings".
59 * Unfortunately MSFT's RNDIS drivers are buggy. They hang or oops, and
60 * have all sorts of contrary-to-specification oddities that can prevent
61 * them from working sanely. Since bugfixes (or accurate specs, letting
62 * Linux work around those bugs) are unlikely to ever come from MSFT, you
63 * may want to avoid using RNDIS on purely operational grounds.
65 * Omissions from the RNDIS 1.0 specification include:
67 * - Power management ... references data that's scattered around lots
68 * of other documentation, which is incorrect/incomplete there too.
70 * - There are various undocumented protocol requirements, like the need
71 * to send garbage in some control-OUT messages.
73 * - MS-Windows drivers sometimes emit undocumented requests.
76 struct rndis_ep_descs {
77 struct usb_endpoint_descriptor *in;
78 struct usb_endpoint_descriptor *out;
79 struct usb_endpoint_descriptor *notify;
88 struct rndis_ep_descs fs;
89 struct rndis_ep_descs hs;
91 struct usb_ep *notify;
92 struct usb_endpoint_descriptor *notify_desc;
93 struct usb_request *notify_req;
94 atomic_t notify_count;
97 static inline struct f_rndis *func_to_rndis(struct usb_function *f)
99 return container_of(f, struct f_rndis, port.func);
102 /* peak (theoretical) bulk transfer rate in bits-per-second */
103 static unsigned int bitrate(struct usb_gadget *g)
105 if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
106 return 13 * 512 * 8 * 1000 * 8;
108 return 19 * 64 * 1 * 1000 * 8;
111 /*-------------------------------------------------------------------------*/
116 #define LOG2_STATUS_INTERVAL_MSEC 5 /* 1 << 5 == 32 msec */
117 #define STATUS_BYTECOUNT 8 /* 8 bytes data */
120 /* interface descriptor: */
122 static struct usb_interface_descriptor rndis_control_intf __initdata = {
123 .bLength = sizeof rndis_control_intf,
124 .bDescriptorType = USB_DT_INTERFACE,
126 /* .bInterfaceNumber = DYNAMIC */
127 /* status endpoint is optional; this could be patched later */
129 .bInterfaceClass = USB_CLASS_COMM,
130 .bInterfaceSubClass = USB_CDC_SUBCLASS_ACM,
131 .bInterfaceProtocol = USB_CDC_ACM_PROTO_VENDOR,
132 /* .iInterface = DYNAMIC */
135 static struct usb_cdc_header_desc header_desc __initdata = {
136 .bLength = sizeof header_desc,
137 .bDescriptorType = USB_DT_CS_INTERFACE,
138 .bDescriptorSubType = USB_CDC_HEADER_TYPE,
140 .bcdCDC = __constant_cpu_to_le16(0x0110),
143 static struct usb_cdc_call_mgmt_descriptor call_mgmt_descriptor __initdata = {
144 .bLength = sizeof call_mgmt_descriptor,
145 .bDescriptorType = USB_DT_CS_INTERFACE,
146 .bDescriptorSubType = USB_CDC_CALL_MANAGEMENT_TYPE,
148 .bmCapabilities = 0x00,
149 .bDataInterface = 0x01,
152 static struct usb_cdc_acm_descriptor acm_descriptor __initdata = {
153 .bLength = sizeof acm_descriptor,
154 .bDescriptorType = USB_DT_CS_INTERFACE,
155 .bDescriptorSubType = USB_CDC_ACM_TYPE,
157 .bmCapabilities = 0x00,
160 static struct usb_cdc_union_desc rndis_union_desc __initdata = {
161 .bLength = sizeof(rndis_union_desc),
162 .bDescriptorType = USB_DT_CS_INTERFACE,
163 .bDescriptorSubType = USB_CDC_UNION_TYPE,
164 /* .bMasterInterface0 = DYNAMIC */
165 /* .bSlaveInterface0 = DYNAMIC */
168 /* the data interface has two bulk endpoints */
170 static struct usb_interface_descriptor rndis_data_intf __initdata = {
171 .bLength = sizeof rndis_data_intf,
172 .bDescriptorType = USB_DT_INTERFACE,
174 /* .bInterfaceNumber = DYNAMIC */
176 .bInterfaceClass = USB_CLASS_CDC_DATA,
177 .bInterfaceSubClass = 0,
178 .bInterfaceProtocol = 0,
179 /* .iInterface = DYNAMIC */
182 /* full speed support: */
184 static struct usb_endpoint_descriptor fs_notify_desc __initdata = {
185 .bLength = USB_DT_ENDPOINT_SIZE,
186 .bDescriptorType = USB_DT_ENDPOINT,
188 .bEndpointAddress = USB_DIR_IN,
189 .bmAttributes = USB_ENDPOINT_XFER_INT,
190 .wMaxPacketSize = __constant_cpu_to_le16(STATUS_BYTECOUNT),
191 .bInterval = 1 << LOG2_STATUS_INTERVAL_MSEC,
194 static struct usb_endpoint_descriptor fs_in_desc __initdata = {
195 .bLength = USB_DT_ENDPOINT_SIZE,
196 .bDescriptorType = USB_DT_ENDPOINT,
198 .bEndpointAddress = USB_DIR_IN,
199 .bmAttributes = USB_ENDPOINT_XFER_BULK,
202 static struct usb_endpoint_descriptor fs_out_desc __initdata = {
203 .bLength = USB_DT_ENDPOINT_SIZE,
204 .bDescriptorType = USB_DT_ENDPOINT,
206 .bEndpointAddress = USB_DIR_OUT,
207 .bmAttributes = USB_ENDPOINT_XFER_BULK,
210 static struct usb_descriptor_header *eth_fs_function[] __initdata = {
211 /* control interface matches ACM, not Ethernet */
212 (struct usb_descriptor_header *) &rndis_control_intf,
213 (struct usb_descriptor_header *) &header_desc,
214 (struct usb_descriptor_header *) &call_mgmt_descriptor,
215 (struct usb_descriptor_header *) &acm_descriptor,
216 (struct usb_descriptor_header *) &rndis_union_desc,
217 (struct usb_descriptor_header *) &fs_notify_desc,
218 /* data interface has no altsetting */
219 (struct usb_descriptor_header *) &rndis_data_intf,
220 (struct usb_descriptor_header *) &fs_in_desc,
221 (struct usb_descriptor_header *) &fs_out_desc,
225 /* high speed support: */
227 static struct usb_endpoint_descriptor hs_notify_desc __initdata = {
228 .bLength = USB_DT_ENDPOINT_SIZE,
229 .bDescriptorType = USB_DT_ENDPOINT,
231 .bEndpointAddress = USB_DIR_IN,
232 .bmAttributes = USB_ENDPOINT_XFER_INT,
233 .wMaxPacketSize = __constant_cpu_to_le16(STATUS_BYTECOUNT),
234 .bInterval = LOG2_STATUS_INTERVAL_MSEC + 4,
236 static struct usb_endpoint_descriptor hs_in_desc __initdata = {
237 .bLength = USB_DT_ENDPOINT_SIZE,
238 .bDescriptorType = USB_DT_ENDPOINT,
240 .bEndpointAddress = USB_DIR_IN,
241 .bmAttributes = USB_ENDPOINT_XFER_BULK,
242 .wMaxPacketSize = __constant_cpu_to_le16(512),
245 static struct usb_endpoint_descriptor hs_out_desc __initdata = {
246 .bLength = USB_DT_ENDPOINT_SIZE,
247 .bDescriptorType = USB_DT_ENDPOINT,
249 .bEndpointAddress = USB_DIR_OUT,
250 .bmAttributes = USB_ENDPOINT_XFER_BULK,
251 .wMaxPacketSize = __constant_cpu_to_le16(512),
254 static struct usb_descriptor_header *eth_hs_function[] __initdata = {
255 /* control interface matches ACM, not Ethernet */
256 (struct usb_descriptor_header *) &rndis_control_intf,
257 (struct usb_descriptor_header *) &header_desc,
258 (struct usb_descriptor_header *) &call_mgmt_descriptor,
259 (struct usb_descriptor_header *) &acm_descriptor,
260 (struct usb_descriptor_header *) &rndis_union_desc,
261 (struct usb_descriptor_header *) &hs_notify_desc,
262 /* data interface has no altsetting */
263 (struct usb_descriptor_header *) &rndis_data_intf,
264 (struct usb_descriptor_header *) &hs_in_desc,
265 (struct usb_descriptor_header *) &hs_out_desc,
269 /* string descriptors: */
271 static struct usb_string rndis_string_defs[] = {
272 [0].s = "RNDIS Communications Control",
273 [1].s = "RNDIS Ethernet Data",
274 { } /* end of list */
277 static struct usb_gadget_strings rndis_string_table = {
278 .language = 0x0409, /* en-us */
279 .strings = rndis_string_defs,
282 static struct usb_gadget_strings *rndis_strings[] = {
287 /*-------------------------------------------------------------------------*/
289 static struct sk_buff *rndis_add_header(struct sk_buff *skb)
291 skb = skb_realloc_headroom(skb, sizeof(struct rndis_packet_msg_type));
297 static void rndis_response_available(void *_rndis)
299 struct f_rndis *rndis = _rndis;
300 struct usb_request *req = rndis->notify_req;
301 struct usb_composite_dev *cdev = rndis->port.func.config->cdev;
302 __le32 *data = req->buf;
305 if (atomic_inc_return(&rndis->notify_count) != 1)
308 /* Send RNDIS RESPONSE_AVAILABLE notification; a
309 * USB_CDC_NOTIFY_RESPONSE_AVAILABLE "should" work too
311 * This is the only notification defined by RNDIS.
313 data[0] = cpu_to_le32(1);
314 data[1] = cpu_to_le32(0);
316 status = usb_ep_queue(rndis->notify, req, GFP_ATOMIC);
318 atomic_dec(&rndis->notify_count);
319 DBG(cdev, "notify/0 --> %d\n", status);
323 static void rndis_response_complete(struct usb_ep *ep, struct usb_request *req)
325 struct f_rndis *rndis = req->context;
326 struct usb_composite_dev *cdev = rndis->port.func.config->cdev;
327 int status = req->status;
330 * - USB_CDC_GET_ENCAPSULATED_RESPONSE (ep0/control)
331 * - RNDIS_RESPONSE_AVAILABLE (status/irq)
336 /* connection gone */
337 atomic_set(&rndis->notify_count, 0);
340 DBG(cdev, "RNDIS %s response error %d, %d/%d\n",
342 req->actual, req->length);
345 if (ep != rndis->notify)
348 /* handle multiple pending RNDIS_RESPONSE_AVAILABLE
349 * notifications by resending until we're done
351 if (atomic_dec_and_test(&rndis->notify_count))
353 status = usb_ep_queue(rndis->notify, req, GFP_ATOMIC);
355 atomic_dec(&rndis->notify_count);
356 DBG(cdev, "notify/1 --> %d\n", status);
362 static void rndis_command_complete(struct usb_ep *ep, struct usb_request *req)
364 struct f_rndis *rndis = req->context;
365 struct usb_composite_dev *cdev = rndis->port.func.config->cdev;
368 /* received RNDIS command from USB_CDC_SEND_ENCAPSULATED_COMMAND */
369 // spin_lock(&dev->lock);
370 status = rndis_msg_parser(rndis->config, (u8 *) req->buf);
372 ERROR(cdev, "RNDIS command error %d, %d/%d\n",
373 status, req->actual, req->length);
374 // spin_unlock(&dev->lock);
378 rndis_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
380 struct f_rndis *rndis = func_to_rndis(f);
381 struct usb_composite_dev *cdev = f->config->cdev;
382 struct usb_request *req = cdev->req;
383 int value = -EOPNOTSUPP;
384 u16 w_index = le16_to_cpu(ctrl->wIndex);
385 u16 w_value = le16_to_cpu(ctrl->wValue);
386 u16 w_length = le16_to_cpu(ctrl->wLength);
388 /* composite driver infrastructure handles everything except
389 * CDC class messages; interface activation uses set_alt().
391 switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
393 /* RNDIS uses the CDC command encapsulation mechanism to implement
394 * an RPC scheme, with much getting/setting of attributes by OID.
396 case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
397 | USB_CDC_SEND_ENCAPSULATED_COMMAND:
398 if (w_length > req->length || w_value
399 || w_index != rndis->ctrl_id)
401 /* read the request; process it later */
403 req->complete = rndis_command_complete;
404 req->context = rndis;
405 /* later, rndis_response_available() sends a notification */
408 case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
409 | USB_CDC_GET_ENCAPSULATED_RESPONSE:
410 if (w_value || w_index != rndis->ctrl_id)
416 /* return the result */
417 buf = rndis_get_next_response(rndis->config, &n);
419 memcpy(req->buf, buf, n);
420 req->complete = rndis_response_complete;
421 rndis_free_response(rndis->config, buf);
424 /* else stalls ... spec says to avoid that */
430 VDBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
431 ctrl->bRequestType, ctrl->bRequest,
432 w_value, w_index, w_length);
435 /* respond with data transfer or status phase? */
437 DBG(cdev, "rndis req%02x.%02x v%04x i%04x l%d\n",
438 ctrl->bRequestType, ctrl->bRequest,
439 w_value, w_index, w_length);
442 value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
444 ERROR(cdev, "rndis response on err %d\n", value);
447 /* device either stalls (value < 0) or reports success */
452 static int rndis_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
454 struct f_rndis *rndis = func_to_rndis(f);
455 struct usb_composite_dev *cdev = f->config->cdev;
457 /* we know alt == 0 */
459 if (intf == rndis->ctrl_id) {
460 if (rndis->notify->driver_data) {
461 VDBG(cdev, "reset rndis control %d\n", intf);
462 usb_ep_disable(rndis->notify);
464 VDBG(cdev, "init rndis ctrl %d\n", intf);
465 rndis->notify_desc = ep_choose(cdev->gadget,
469 usb_ep_enable(rndis->notify, rndis->notify_desc);
470 rndis->notify->driver_data = rndis;
472 } else if (intf == rndis->data_id) {
473 struct net_device *net;
475 if (rndis->port.in_ep->driver_data) {
476 DBG(cdev, "reset rndis\n");
477 gether_disconnect(&rndis->port);
479 DBG(cdev, "init rndis\n");
480 rndis->port.in = ep_choose(cdev->gadget,
481 rndis->hs.in, rndis->fs.in);
482 rndis->port.out = ep_choose(cdev->gadget,
483 rndis->hs.out, rndis->fs.out);
486 /* Avoid ZLPs; they can be troublesome. */
487 rndis->port.is_zlp_ok = false;
489 /* RNDIS should be in the "RNDIS uninitialized" state,
490 * either never activated or after rndis_uninit().
492 * We don't want data to flow here until a nonzero packet
493 * filter is set, at which point it enters "RNDIS data
494 * initialized" state ... but we do want the endpoints
495 * to be activated. It's a strange little state.
497 * REVISIT the RNDIS gadget code has done this wrong for a
498 * very long time. We need another call to the link layer
499 * code -- gether_updown(...bool) maybe -- to do it right.
501 rndis->port.cdc_filter = 0;
503 DBG(cdev, "RNDIS RX/TX early activation ... \n");
504 net = gether_connect(&rndis->port);
508 rndis_set_param_dev(rndis->config, net,
509 &rndis->port.cdc_filter);
518 static void rndis_disable(struct usb_function *f)
520 struct f_rndis *rndis = func_to_rndis(f);
521 struct usb_composite_dev *cdev = f->config->cdev;
523 if (!rndis->notify->driver_data)
526 DBG(cdev, "rndis deactivated\n");
528 rndis_uninit(rndis->config);
529 gether_disconnect(&rndis->port);
531 usb_ep_disable(rndis->notify);
532 rndis->notify->driver_data = NULL;
535 /*-------------------------------------------------------------------------*/
538 * This isn't quite the same mechanism as CDC Ethernet, since the
539 * notification scheme passes less data, but the same set of link
540 * states must be tested. A key difference is that altsettings are
541 * not used to tell whether the link should send packets or not.
544 static void rndis_open(struct gether *geth)
546 struct f_rndis *rndis = func_to_rndis(&geth->func);
547 struct usb_composite_dev *cdev = geth->func.config->cdev;
549 DBG(cdev, "%s\n", __func__);
551 rndis_set_param_medium(rndis->config, NDIS_MEDIUM_802_3,
552 bitrate(cdev->gadget) / 100);
553 rndis_signal_connect(rndis->config);
556 static void rndis_close(struct gether *geth)
558 struct f_rndis *rndis = func_to_rndis(&geth->func);
560 DBG(geth->func.config->cdev, "%s\n", __func__);
562 rndis_set_param_medium(rndis->config, NDIS_MEDIUM_802_3, 0);
563 rndis_signal_disconnect(rndis->config);
566 /*-------------------------------------------------------------------------*/
568 /* ethernet function driver setup/binding */
571 rndis_bind(struct usb_configuration *c, struct usb_function *f)
573 struct usb_composite_dev *cdev = c->cdev;
574 struct f_rndis *rndis = func_to_rndis(f);
578 /* allocate instance-specific interface IDs */
579 status = usb_interface_id(c, f);
582 rndis->ctrl_id = status;
584 rndis_control_intf.bInterfaceNumber = status;
585 rndis_union_desc.bMasterInterface0 = status;
587 status = usb_interface_id(c, f);
590 rndis->data_id = status;
592 rndis_data_intf.bInterfaceNumber = status;
593 rndis_union_desc.bSlaveInterface0 = status;
597 /* allocate instance-specific endpoints */
598 ep = usb_ep_autoconfig(cdev->gadget, &fs_in_desc);
601 rndis->port.in_ep = ep;
602 ep->driver_data = cdev; /* claim */
604 ep = usb_ep_autoconfig(cdev->gadget, &fs_out_desc);
607 rndis->port.out_ep = ep;
608 ep->driver_data = cdev; /* claim */
610 /* NOTE: a status/notification endpoint is, strictly speaking,
611 * optional. We don't treat it that way though! It's simpler,
612 * and some newer profiles don't treat it as optional.
614 ep = usb_ep_autoconfig(cdev->gadget, &fs_notify_desc);
618 ep->driver_data = cdev; /* claim */
622 /* allocate notification request and buffer */
623 rndis->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
624 if (!rndis->notify_req)
626 rndis->notify_req->buf = kmalloc(STATUS_BYTECOUNT, GFP_KERNEL);
627 if (!rndis->notify_req->buf)
629 rndis->notify_req->length = STATUS_BYTECOUNT;
630 rndis->notify_req->context = rndis;
631 rndis->notify_req->complete = rndis_response_complete;
633 /* copy descriptors, and track endpoint copies */
634 f->descriptors = usb_copy_descriptors(eth_fs_function);
638 rndis->fs.in = usb_find_endpoint(eth_fs_function,
639 f->descriptors, &fs_in_desc);
640 rndis->fs.out = usb_find_endpoint(eth_fs_function,
641 f->descriptors, &fs_out_desc);
642 rndis->fs.notify = usb_find_endpoint(eth_fs_function,
643 f->descriptors, &fs_notify_desc);
645 /* support all relevant hardware speeds... we expect that when
646 * hardware is dual speed, all bulk-capable endpoints work at
649 if (gadget_is_dualspeed(c->cdev->gadget)) {
650 hs_in_desc.bEndpointAddress =
651 fs_in_desc.bEndpointAddress;
652 hs_out_desc.bEndpointAddress =
653 fs_out_desc.bEndpointAddress;
655 /* copy descriptors, and track endpoint copies */
656 f->hs_descriptors = usb_copy_descriptors(eth_hs_function);
658 if (!f->hs_descriptors)
661 rndis->hs.in = usb_find_endpoint(eth_hs_function,
662 f->hs_descriptors, &hs_in_desc);
663 rndis->hs.out = usb_find_endpoint(eth_hs_function,
664 f->hs_descriptors, &hs_out_desc);
667 rndis->port.open = rndis_open;
668 rndis->port.close = rndis_close;
670 status = rndis_register(rndis_response_available, rndis);
673 rndis->config = status;
675 rndis_set_param_medium(rndis->config, NDIS_MEDIUM_802_3, 0);
676 rndis_set_host_mac(rndis->config, rndis->ethaddr);
680 if (rndis_set_param_vendor(rndis->config, vendorID,
685 /* NOTE: all that is done without knowing or caring about
686 * the network link ... which is unavailable to this code
687 * until we're activated via set_alt().
690 DBG(cdev, "RNDIS: %s speed IN/%s OUT/%s NOTIFY/%s\n",
691 gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
692 rndis->port.in_ep->name, rndis->port.out_ep->name,
693 rndis->notify->name);
697 if (gadget_is_dualspeed(c->cdev->gadget) && f->hs_descriptors)
698 usb_free_descriptors(f->hs_descriptors);
700 usb_free_descriptors(f->descriptors);
702 if (rndis->notify_req) {
703 kfree(rndis->notify_req->buf);
704 usb_ep_free_request(rndis->notify, rndis->notify_req);
707 /* we might as well release our claims on endpoints */
709 rndis->notify->driver_data = NULL;
711 rndis->port.out_ep->driver_data = NULL;
713 rndis->port.in_ep->driver_data = NULL;
715 ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
721 rndis_unbind(struct usb_configuration *c, struct usb_function *f)
723 struct f_rndis *rndis = func_to_rndis(f);
725 rndis_deregister(rndis->config);
728 if (gadget_is_dualspeed(c->cdev->gadget))
729 usb_free_descriptors(f->hs_descriptors);
730 usb_free_descriptors(f->descriptors);
732 kfree(rndis->notify_req->buf);
733 usb_ep_free_request(rndis->notify, rndis->notify_req);
738 /* Some controllers can't support RNDIS ... */
739 static inline bool can_support_rndis(struct usb_configuration *c)
741 /* only two endpoints on sa1100 */
742 if (gadget_is_sa1100(c->cdev->gadget))
745 /* everything else is *presumably* fine */
750 * rndis_bind_config - add RNDIS network link to a configuration
751 * @c: the configuration to support the network link
752 * @ethaddr: a buffer in which the ethernet address of the host side
753 * side of the link was recorded
754 * Context: single threaded during gadget setup
756 * Returns zero on success, else negative errno.
758 * Caller must have called @gether_setup(). Caller is also responsible
759 * for calling @gether_cleanup() before module unload.
761 int __init rndis_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN])
763 struct f_rndis *rndis;
766 if (!can_support_rndis(c) || !ethaddr)
769 /* maybe allocate device-global string IDs */
770 if (rndis_string_defs[0].id == 0) {
772 /* ... and setup RNDIS itself */
773 status = rndis_init();
777 /* control interface label */
778 status = usb_string_id(c->cdev);
781 rndis_string_defs[0].id = status;
782 rndis_control_intf.iInterface = status;
784 /* data interface label */
785 status = usb_string_id(c->cdev);
788 rndis_string_defs[1].id = status;
789 rndis_data_intf.iInterface = status;
792 /* allocate and initialize one new instance */
794 rndis = kzalloc(sizeof *rndis, GFP_KERNEL);
798 memcpy(rndis->ethaddr, ethaddr, ETH_ALEN);
800 /* RNDIS activates when the host changes this filter */
801 rndis->port.cdc_filter = 0;
803 /* RNDIS has special (and complex) framing */
804 rndis->port.header_len = sizeof(struct rndis_packet_msg_type);
805 rndis->port.wrap = rndis_add_header;
806 rndis->port.unwrap = rndis_rm_hdr;
808 rndis->port.func.name = "rndis";
809 rndis->port.func.strings = rndis_strings;
810 /* descriptors are per-instance copies */
811 rndis->port.func.bind = rndis_bind;
812 rndis->port.func.unbind = rndis_unbind;
813 rndis->port.func.set_alt = rndis_set_alt;
814 rndis->port.func.setup = rndis_setup;
815 rndis->port.func.disable = rndis_disable;
817 status = usb_add_function(c, &rndis->port.func);