Bootlin logo

Elixir Cross Referencer

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
/*
 * f_rndis.c -- RNDIS link function driver
 *
 * Copyright (C) 2003-2005,2008 David Brownell
 * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
 * Copyright (C) 2008 Nokia Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

/* #define VERBOSE_DEBUG */

#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/etherdevice.h>

#include <asm/atomic.h>

#include "u_ether.h"
#include "rndis.h"


/*
 * This function is an RNDIS Ethernet port -- a Microsoft protocol that's
 * been promoted instead of the standard CDC Ethernet.  The published RNDIS
 * spec is ambiguous, incomplete, and needlessly complex.  Variants such as
 * ActiveSync have even worse status in terms of specification.
 *
 * In short:  it's a protocol controlled by (and for) Microsoft, not for an
 * Open ecosystem or markets.  Linux supports it *only* because Microsoft
 * doesn't support the CDC Ethernet standard.
 *
 * The RNDIS data transfer model is complex, with multiple Ethernet packets
 * per USB message, and out of band data.  The control model is built around
 * what's essentially an "RNDIS RPC" protocol.  It's all wrapped in a CDC ACM
 * (modem, not Ethernet) veneer, with those ACM descriptors being entirely
 * useless (they're ignored).  RNDIS expects to be the only function in its
 * configuration, so it's no real help if you need composite devices; and
 * it expects to be the first configuration too.
 *
 * There is a single technical advantage of RNDIS over CDC Ethernet, if you
 * discount the fluff that its RPC can be made to deliver: it doesn't need
 * a NOP altsetting for the data interface.  That lets it work on some of the
 * "so smart it's stupid" hardware which takes over configuration changes
 * from the software, and adds restrictions like "no altsettings".
 *
 * Unfortunately MSFT's RNDIS drivers are buggy.  They hang or oops, and
 * have all sorts of contrary-to-specification oddities that can prevent
 * them from working sanely.  Since bugfixes (or accurate specs, letting
 * Linux work around those bugs) are unlikely to ever come from MSFT, you
 * may want to avoid using RNDIS on purely operational grounds.
 *
 * Omissions from the RNDIS 1.0 specification include:
 *
 *   - Power management ... references data that's scattered around lots
 *     of other documentation, which is incorrect/incomplete there too.
 *
 *   - There are various undocumented protocol requirements, like the need
 *     to send garbage in some control-OUT messages.
 *
 *   - MS-Windows drivers sometimes emit undocumented requests.
 */

struct rndis_ep_descs {
	struct usb_endpoint_descriptor	*in;
	struct usb_endpoint_descriptor	*out;
	struct usb_endpoint_descriptor	*notify;
};

struct f_rndis {
	struct gether			port;
	u8				ctrl_id, data_id;
	u8				ethaddr[ETH_ALEN];
	int				config;

	struct rndis_ep_descs		fs;
	struct rndis_ep_descs		hs;

	struct usb_ep			*notify;
	struct usb_endpoint_descriptor	*notify_desc;
	struct usb_request		*notify_req;
	atomic_t			notify_count;
};

static inline struct f_rndis *func_to_rndis(struct usb_function *f)
{
	return container_of(f, struct f_rndis, port.func);
}

/* peak (theoretical) bulk transfer rate in bits-per-second */
static unsigned int bitrate(struct usb_gadget *g)
{
	if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
		return 13 * 512 * 8 * 1000 * 8;
	else
		return 19 *  64 * 1 * 1000 * 8;
}

/*-------------------------------------------------------------------------*/

/*
 */

#define LOG2_STATUS_INTERVAL_MSEC	5	/* 1 << 5 == 32 msec */
#define STATUS_BYTECOUNT		8	/* 8 bytes data */


/* interface descriptor: */

static struct usb_interface_descriptor rndis_control_intf __initdata = {
	.bLength =		sizeof rndis_control_intf,
	.bDescriptorType =	USB_DT_INTERFACE,

	/* .bInterfaceNumber = DYNAMIC */
	/* status endpoint is optional; this could be patched later */
	.bNumEndpoints =	1,
	.bInterfaceClass =	USB_CLASS_COMM,
	.bInterfaceSubClass =   USB_CDC_SUBCLASS_ACM,
	.bInterfaceProtocol =   USB_CDC_ACM_PROTO_VENDOR,
	/* .iInterface = DYNAMIC */
};

static struct usb_cdc_header_desc header_desc __initdata = {
	.bLength =		sizeof header_desc,
	.bDescriptorType =	USB_DT_CS_INTERFACE,
	.bDescriptorSubType =	USB_CDC_HEADER_TYPE,

	.bcdCDC =		cpu_to_le16(0x0110),
};

static struct usb_cdc_call_mgmt_descriptor call_mgmt_descriptor __initdata = {
	.bLength =		sizeof call_mgmt_descriptor,
	.bDescriptorType =	USB_DT_CS_INTERFACE,
	.bDescriptorSubType =	USB_CDC_CALL_MANAGEMENT_TYPE,

	.bmCapabilities =	0x00,
	.bDataInterface =	0x01,
};

static struct usb_cdc_acm_descriptor acm_descriptor __initdata = {
	.bLength =		sizeof acm_descriptor,
	.bDescriptorType =	USB_DT_CS_INTERFACE,
	.bDescriptorSubType =	USB_CDC_ACM_TYPE,

	.bmCapabilities =	0x00,
};

static struct usb_cdc_union_desc rndis_union_desc __initdata = {
	.bLength =		sizeof(rndis_union_desc),
	.bDescriptorType =	USB_DT_CS_INTERFACE,
	.bDescriptorSubType =	USB_CDC_UNION_TYPE,
	/* .bMasterInterface0 =	DYNAMIC */
	/* .bSlaveInterface0 =	DYNAMIC */
};

/* the data interface has two bulk endpoints */

static struct usb_interface_descriptor rndis_data_intf __initdata = {
	.bLength =		sizeof rndis_data_intf,
	.bDescriptorType =	USB_DT_INTERFACE,

	/* .bInterfaceNumber = DYNAMIC */
	.bNumEndpoints =	2,
	.bInterfaceClass =	USB_CLASS_CDC_DATA,
	.bInterfaceSubClass =	0,
	.bInterfaceProtocol =	0,
	/* .iInterface = DYNAMIC */
};

/* full speed support: */

static struct usb_endpoint_descriptor fs_notify_desc __initdata = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,

	.bEndpointAddress =	USB_DIR_IN,
	.bmAttributes =		USB_ENDPOINT_XFER_INT,
	.wMaxPacketSize =	cpu_to_le16(STATUS_BYTECOUNT),
	.bInterval =		1 << LOG2_STATUS_INTERVAL_MSEC,
};

static struct usb_endpoint_descriptor fs_in_desc __initdata = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,

	.bEndpointAddress =	USB_DIR_IN,
	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
};

static struct usb_endpoint_descriptor fs_out_desc __initdata = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,

	.bEndpointAddress =	USB_DIR_OUT,
	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
};

static struct usb_descriptor_header *eth_fs_function[] __initdata = {
	/* control interface matches ACM, not Ethernet */
	(struct usb_descriptor_header *) &rndis_control_intf,
	(struct usb_descriptor_header *) &header_desc,
	(struct usb_descriptor_header *) &call_mgmt_descriptor,
	(struct usb_descriptor_header *) &acm_descriptor,
	(struct usb_descriptor_header *) &rndis_union_desc,
	(struct usb_descriptor_header *) &fs_notify_desc,
	/* data interface has no altsetting */
	(struct usb_descriptor_header *) &rndis_data_intf,
	(struct usb_descriptor_header *) &fs_in_desc,
	(struct usb_descriptor_header *) &fs_out_desc,
	NULL,
};

/* high speed support: */

static struct usb_endpoint_descriptor hs_notify_desc __initdata = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,

	.bEndpointAddress =	USB_DIR_IN,
	.bmAttributes =		USB_ENDPOINT_XFER_INT,
	.wMaxPacketSize =	cpu_to_le16(STATUS_BYTECOUNT),
	.bInterval =		LOG2_STATUS_INTERVAL_MSEC + 4,
};
static struct usb_endpoint_descriptor hs_in_desc __initdata = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,

	.bEndpointAddress =	USB_DIR_IN,
	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
	.wMaxPacketSize =	cpu_to_le16(512),
};

static struct usb_endpoint_descriptor hs_out_desc __initdata = {
	.bLength =		USB_DT_ENDPOINT_SIZE,
	.bDescriptorType =	USB_DT_ENDPOINT,

	.bEndpointAddress =	USB_DIR_OUT,
	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
	.wMaxPacketSize =	cpu_to_le16(512),
};

static struct usb_descriptor_header *eth_hs_function[] __initdata = {
	/* control interface matches ACM, not Ethernet */
	(struct usb_descriptor_header *) &rndis_control_intf,
	(struct usb_descriptor_header *) &header_desc,
	(struct usb_descriptor_header *) &call_mgmt_descriptor,
	(struct usb_descriptor_header *) &acm_descriptor,
	(struct usb_descriptor_header *) &rndis_union_desc,
	(struct usb_descriptor_header *) &hs_notify_desc,
	/* data interface has no altsetting */
	(struct usb_descriptor_header *) &rndis_data_intf,
	(struct usb_descriptor_header *) &hs_in_desc,
	(struct usb_descriptor_header *) &hs_out_desc,
	NULL,
};

/* string descriptors: */

static struct usb_string rndis_string_defs[] = {
	[0].s = "RNDIS Communications Control",
	[1].s = "RNDIS Ethernet Data",
	{  } /* end of list */
};

static struct usb_gadget_strings rndis_string_table = {
	.language =		0x0409,	/* en-us */
	.strings =		rndis_string_defs,
};

static struct usb_gadget_strings *rndis_strings[] = {
	&rndis_string_table,
	NULL,
};

/*-------------------------------------------------------------------------*/

static struct sk_buff *rndis_add_header(struct gether *port,
					struct sk_buff *skb)
{
	struct sk_buff *skb2;

	skb2 = skb_realloc_headroom(skb, sizeof(struct rndis_packet_msg_type));
	if (skb2)
		rndis_add_hdr(skb2);

	dev_kfree_skb_any(skb);
	return skb2;
}

static void rndis_response_available(void *_rndis)
{
	struct f_rndis			*rndis = _rndis;
	struct usb_request		*req = rndis->notify_req;
	struct usb_composite_dev	*cdev = rndis->port.func.config->cdev;
	__le32				*data = req->buf;
	int				status;

	if (atomic_inc_return(&rndis->notify_count) != 1)
		return;

	/* Send RNDIS RESPONSE_AVAILABLE notification; a
	 * USB_CDC_NOTIFY_RESPONSE_AVAILABLE "should" work too
	 *
	 * This is the only notification defined by RNDIS.
	 */
	data[0] = cpu_to_le32(1);
	data[1] = cpu_to_le32(0);

	status = usb_ep_queue(rndis->notify, req, GFP_ATOMIC);
	if (status) {
		atomic_dec(&rndis->notify_count);
		DBG(cdev, "notify/0 --> %d\n", status);
	}
}

static void rndis_response_complete(struct usb_ep *ep, struct usb_request *req)
{
	struct f_rndis			*rndis = req->context;
	struct usb_composite_dev	*cdev = rndis->port.func.config->cdev;
	int				status = req->status;

	/* after TX:
	 *  - USB_CDC_GET_ENCAPSULATED_RESPONSE (ep0/control)
	 *  - RNDIS_RESPONSE_AVAILABLE (status/irq)
	 */
	switch (status) {
	case -ECONNRESET:
	case -ESHUTDOWN:
		/* connection gone */
		atomic_set(&rndis->notify_count, 0);
		break;
	default:
		DBG(cdev, "RNDIS %s response error %d, %d/%d\n",
			ep->name, status,
			req->actual, req->length);
		/* FALLTHROUGH */
	case 0:
		if (ep != rndis->notify)
			break;

		/* handle multiple pending RNDIS_RESPONSE_AVAILABLE
		 * notifications by resending until we're done
		 */
		if (atomic_dec_and_test(&rndis->notify_count))
			break;
		status = usb_ep_queue(rndis->notify, req, GFP_ATOMIC);
		if (status) {
			atomic_dec(&rndis->notify_count);
			DBG(cdev, "notify/1 --> %d\n", status);
		}
		break;
	}
}

static void rndis_command_complete(struct usb_ep *ep, struct usb_request *req)
{
	struct f_rndis			*rndis = req->context;
	struct usb_composite_dev	*cdev = rndis->port.func.config->cdev;
	int				status;

	/* received RNDIS command from USB_CDC_SEND_ENCAPSULATED_COMMAND */
//	spin_lock(&dev->lock);
	status = rndis_msg_parser(rndis->config, (u8 *) req->buf);
	if (status < 0)
		ERROR(cdev, "RNDIS command error %d, %d/%d\n",
			status, req->actual, req->length);
//	spin_unlock(&dev->lock);
}

static int
rndis_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
{
	struct f_rndis		*rndis = func_to_rndis(f);
	struct usb_composite_dev *cdev = f->config->cdev;
	struct usb_request	*req = cdev->req;
	int			value = -EOPNOTSUPP;
	u16			w_index = le16_to_cpu(ctrl->wIndex);
	u16			w_value = le16_to_cpu(ctrl->wValue);
	u16			w_length = le16_to_cpu(ctrl->wLength);

	/* composite driver infrastructure handles everything except
	 * CDC class messages; interface activation uses set_alt().
	 */
	switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {

	/* RNDIS uses the CDC command encapsulation mechanism to implement
	 * an RPC scheme, with much getting/setting of attributes by OID.
	 */
	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
			| USB_CDC_SEND_ENCAPSULATED_COMMAND:
		if (w_length > req->length || w_value
				|| w_index != rndis->ctrl_id)
			goto invalid;
		/* read the request; process it later */
		value = w_length;
		req->complete = rndis_command_complete;
		req->context = rndis;
		/* later, rndis_response_available() sends a notification */
		break;

	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
			| USB_CDC_GET_ENCAPSULATED_RESPONSE:
		if (w_value || w_index != rndis->ctrl_id)
			goto invalid;
		else {
			u8 *buf;
			u32 n;

			/* return the result */
			buf = rndis_get_next_response(rndis->config, &n);
			if (buf) {
				memcpy(req->buf, buf, n);
				req->complete = rndis_response_complete;
				rndis_free_response(rndis->config, buf);
				value = n;
			}
			/* else stalls ... spec says to avoid that */
		}
		break;

	default:
invalid:
		VDBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
			ctrl->bRequestType, ctrl->bRequest,
			w_value, w_index, w_length);
	}

	/* respond with data transfer or status phase? */
	if (value >= 0) {
		DBG(cdev, "rndis req%02x.%02x v%04x i%04x l%d\n",
			ctrl->bRequestType, ctrl->bRequest,
			w_value, w_index, w_length);
		req->zero = (value < w_length);
		req->length = value;
		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
		if (value < 0)
			ERROR(cdev, "rndis response on err %d\n", value);
	}

	/* device either stalls (value < 0) or reports success */
	return value;
}


static int rndis_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
{
	struct f_rndis		*rndis = func_to_rndis(f);
	struct usb_composite_dev *cdev = f->config->cdev;

	/* we know alt == 0 */

	if (intf == rndis->ctrl_id) {
		if (rndis->notify->driver_data) {
			VDBG(cdev, "reset rndis control %d\n", intf);
			usb_ep_disable(rndis->notify);
		} else {
			VDBG(cdev, "init rndis ctrl %d\n", intf);
			rndis->notify_desc = ep_choose(cdev->gadget,
					rndis->hs.notify,
					rndis->fs.notify);
		}
		usb_ep_enable(rndis->notify, rndis->notify_desc);
		rndis->notify->driver_data = rndis;

	} else if (intf == rndis->data_id) {
		struct net_device	*net;

		if (rndis->port.in_ep->driver_data) {
			DBG(cdev, "reset rndis\n");
			gether_disconnect(&rndis->port);
		}

		if (!rndis->port.in) {
			DBG(cdev, "init rndis\n");
			rndis->port.in = ep_choose(cdev->gadget,
					rndis->hs.in, rndis->fs.in);
			rndis->port.out = ep_choose(cdev->gadget,
					rndis->hs.out, rndis->fs.out);
		}

		/* Avoid ZLPs; they can be troublesome. */
		rndis->port.is_zlp_ok = false;

		/* RNDIS should be in the "RNDIS uninitialized" state,
		 * either never activated or after rndis_uninit().
		 *
		 * We don't want data to flow here until a nonzero packet
		 * filter is set, at which point it enters "RNDIS data
		 * initialized" state ... but we do want the endpoints
		 * to be activated.  It's a strange little state.
		 *
		 * REVISIT the RNDIS gadget code has done this wrong for a
		 * very long time.  We need another call to the link layer
		 * code -- gether_updown(...bool) maybe -- to do it right.
		 */
		rndis->port.cdc_filter = 0;

		DBG(cdev, "RNDIS RX/TX early activation ... \n");
		net = gether_connect(&rndis->port);
		if (IS_ERR(net))
			return PTR_ERR(net);

		rndis_set_param_dev(rndis->config, net,
				&rndis->port.cdc_filter);
	} else
		goto fail;

	return 0;
fail:
	return -EINVAL;
}

static void rndis_disable(struct usb_function *f)
{
	struct f_rndis		*rndis = func_to_rndis(f);
	struct usb_composite_dev *cdev = f->config->cdev;

	if (!rndis->notify->driver_data)
		return;

	DBG(cdev, "rndis deactivated\n");

	rndis_uninit(rndis->config);
	gether_disconnect(&rndis->port);

	usb_ep_disable(rndis->notify);
	rndis->notify->driver_data = NULL;
}

/*-------------------------------------------------------------------------*/

/*
 * This isn't quite the same mechanism as CDC Ethernet, since the
 * notification scheme passes less data, but the same set of link
 * states must be tested.  A key difference is that altsettings are
 * not used to tell whether the link should send packets or not.
 */

static void rndis_open(struct gether *geth)
{
	struct f_rndis		*rndis = func_to_rndis(&geth->func);
	struct usb_composite_dev *cdev = geth->func.config->cdev;

	DBG(cdev, "%s\n", __func__);

	rndis_set_param_medium(rndis->config, NDIS_MEDIUM_802_3,
				bitrate(cdev->gadget) / 100);
	rndis_signal_connect(rndis->config);
}

static void rndis_close(struct gether *geth)
{
	struct f_rndis		*rndis = func_to_rndis(&geth->func);

	DBG(geth->func.config->cdev, "%s\n", __func__);

	rndis_set_param_medium(rndis->config, NDIS_MEDIUM_802_3, 0);
	rndis_signal_disconnect(rndis->config);
}

/*-------------------------------------------------------------------------*/

/* ethernet function driver setup/binding */

static int __init
rndis_bind(struct usb_configuration *c, struct usb_function *f)
{
	struct usb_composite_dev *cdev = c->cdev;
	struct f_rndis		*rndis = func_to_rndis(f);
	int			status;
	struct usb_ep		*ep;

	/* allocate instance-specific interface IDs */
	status = usb_interface_id(c, f);
	if (status < 0)
		goto fail;
	rndis->ctrl_id = status;

	rndis_control_intf.bInterfaceNumber = status;
	rndis_union_desc.bMasterInterface0 = status;

	status = usb_interface_id(c, f);
	if (status < 0)
		goto fail;
	rndis->data_id = status;

	rndis_data_intf.bInterfaceNumber = status;
	rndis_union_desc.bSlaveInterface0 = status;

	status = -ENODEV;

	/* allocate instance-specific endpoints */
	ep = usb_ep_autoconfig(cdev->gadget, &fs_in_desc);
	if (!ep)
		goto fail;
	rndis->port.in_ep = ep;
	ep->driver_data = cdev;	/* claim */

	ep = usb_ep_autoconfig(cdev->gadget, &fs_out_desc);
	if (!ep)
		goto fail;
	rndis->port.out_ep = ep;
	ep->driver_data = cdev;	/* claim */

	/* NOTE:  a status/notification endpoint is, strictly speaking,
	 * optional.  We don't treat it that way though!  It's simpler,
	 * and some newer profiles don't treat it as optional.
	 */
	ep = usb_ep_autoconfig(cdev->gadget, &fs_notify_desc);
	if (!ep)
		goto fail;
	rndis->notify = ep;
	ep->driver_data = cdev;	/* claim */

	status = -ENOMEM;

	/* allocate notification request and buffer */
	rndis->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
	if (!rndis->notify_req)
		goto fail;
	rndis->notify_req->buf = kmalloc(STATUS_BYTECOUNT, GFP_KERNEL);
	if (!rndis->notify_req->buf)
		goto fail;
	rndis->notify_req->length = STATUS_BYTECOUNT;
	rndis->notify_req->context = rndis;
	rndis->notify_req->complete = rndis_response_complete;

	/* copy descriptors, and track endpoint copies */
	f->descriptors = usb_copy_descriptors(eth_fs_function);
	if (!f->descriptors)
		goto fail;

	rndis->fs.in = usb_find_endpoint(eth_fs_function,
			f->descriptors, &fs_in_desc);
	rndis->fs.out = usb_find_endpoint(eth_fs_function,
			f->descriptors, &fs_out_desc);
	rndis->fs.notify = usb_find_endpoint(eth_fs_function,
			f->descriptors, &fs_notify_desc);

	/* support all relevant hardware speeds... we expect that when
	 * hardware is dual speed, all bulk-capable endpoints work at
	 * both speeds
	 */
	if (gadget_is_dualspeed(c->cdev->gadget)) {
		hs_in_desc.bEndpointAddress =
				fs_in_desc.bEndpointAddress;
		hs_out_desc.bEndpointAddress =
				fs_out_desc.bEndpointAddress;
		hs_notify_desc.bEndpointAddress =
				fs_notify_desc.bEndpointAddress;

		/* copy descriptors, and track endpoint copies */
		f->hs_descriptors = usb_copy_descriptors(eth_hs_function);

		if (!f->hs_descriptors)
			goto fail;

		rndis->hs.in = usb_find_endpoint(eth_hs_function,
				f->hs_descriptors, &hs_in_desc);
		rndis->hs.out = usb_find_endpoint(eth_hs_function,
				f->hs_descriptors, &hs_out_desc);
		rndis->hs.notify = usb_find_endpoint(eth_hs_function,
				f->hs_descriptors, &hs_notify_desc);
	}

	rndis->port.open = rndis_open;
	rndis->port.close = rndis_close;

	status = rndis_register(rndis_response_available, rndis);
	if (status < 0)
		goto fail;
	rndis->config = status;

	rndis_set_param_medium(rndis->config, NDIS_MEDIUM_802_3, 0);
	rndis_set_host_mac(rndis->config, rndis->ethaddr);

#if 0
// FIXME
	if (rndis_set_param_vendor(rndis->config, vendorID,
				manufacturer))
		goto fail0;
#endif

	/* NOTE:  all that is done without knowing or caring about
	 * the network link ... which is unavailable to this code
	 * until we're activated via set_alt().
	 */

	DBG(cdev, "RNDIS: %s speed IN/%s OUT/%s NOTIFY/%s\n",
			gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
			rndis->port.in_ep->name, rndis->port.out_ep->name,
			rndis->notify->name);
	return 0;

fail:
	if (gadget_is_dualspeed(c->cdev->gadget) && f->hs_descriptors)
		usb_free_descriptors(f->hs_descriptors);
	if (f->descriptors)
		usb_free_descriptors(f->descriptors);

	if (rndis->notify_req) {
		kfree(rndis->notify_req->buf);
		usb_ep_free_request(rndis->notify, rndis->notify_req);
	}

	/* we might as well release our claims on endpoints */
	if (rndis->notify)
		rndis->notify->driver_data = NULL;
	if (rndis->port.out)
		rndis->port.out_ep->driver_data = NULL;
	if (rndis->port.in)
		rndis->port.in_ep->driver_data = NULL;

	ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);

	return status;
}

static void
rndis_unbind(struct usb_configuration *c, struct usb_function *f)
{
	struct f_rndis		*rndis = func_to_rndis(f);

	rndis_deregister(rndis->config);
	rndis_exit();

	if (gadget_is_dualspeed(c->cdev->gadget))
		usb_free_descriptors(f->hs_descriptors);
	usb_free_descriptors(f->descriptors);

	kfree(rndis->notify_req->buf);
	usb_ep_free_request(rndis->notify, rndis->notify_req);

	kfree(rndis);
}

/* Some controllers can't support RNDIS ... */
static inline bool can_support_rndis(struct usb_configuration *c)
{
	/* only two endpoints on sa1100 */
	if (gadget_is_sa1100(c->cdev->gadget))
		return false;

	/* everything else is *presumably* fine */
	return true;
}

/**
 * rndis_bind_config - add RNDIS network link to a configuration
 * @c: the configuration to support the network link
 * @ethaddr: a buffer in which the ethernet address of the host side
 *	side of the link was recorded
 * Context: single threaded during gadget setup
 *
 * Returns zero on success, else negative errno.
 *
 * Caller must have called @gether_setup().  Caller is also responsible
 * for calling @gether_cleanup() before module unload.
 */
int __init rndis_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN])
{
	struct f_rndis	*rndis;
	int		status;

	if (!can_support_rndis(c) || !ethaddr)
		return -EINVAL;

	/* maybe allocate device-global string IDs */
	if (rndis_string_defs[0].id == 0) {

		/* ... and setup RNDIS itself */
		status = rndis_init();
		if (status < 0)
			return status;

		/* control interface label */
		status = usb_string_id(c->cdev);
		if (status < 0)
			return status;
		rndis_string_defs[0].id = status;
		rndis_control_intf.iInterface = status;

		/* data interface label */
		status = usb_string_id(c->cdev);
		if (status < 0)
			return status;
		rndis_string_defs[1].id = status;
		rndis_data_intf.iInterface = status;
	}

	/* allocate and initialize one new instance */
	status = -ENOMEM;
	rndis = kzalloc(sizeof *rndis, GFP_KERNEL);
	if (!rndis)
		goto fail;

	memcpy(rndis->ethaddr, ethaddr, ETH_ALEN);

	/* RNDIS activates when the host changes this filter */
	rndis->port.cdc_filter = 0;

	/* RNDIS has special (and complex) framing */
	rndis->port.header_len = sizeof(struct rndis_packet_msg_type);
	rndis->port.wrap = rndis_add_header;
	rndis->port.unwrap = rndis_rm_hdr;

	rndis->port.func.name = "rndis";
	rndis->port.func.strings = rndis_strings;
	/* descriptors are per-instance copies */
	rndis->port.func.bind = rndis_bind;
	rndis->port.func.unbind = rndis_unbind;
	rndis->port.func.set_alt = rndis_set_alt;
	rndis->port.func.setup = rndis_setup;
	rndis->port.func.disable = rndis_disable;

	status = usb_add_function(c, &rndis->port.func);
	if (status) {
		kfree(rndis);
fail:
		rndis_exit();
	}
	return status;
}