1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * f_rndis.c -- RNDIS link function driver
4 *
5 * Copyright (C) 2003-2005,2008 David Brownell
6 * Copyright (C) 2003-2004 Robert Schwebel, Benedikt Spranger
7 * Copyright (C) 2008 Nokia Corporation
8 * Copyright (C) 2009 Samsung Electronics
9 *                    Author: Michal Nazarewicz (mina86@mina86.com)
10 */
11
12/* #define VERBOSE_DEBUG */
13
14#include <linux/slab.h>
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/device.h>
18#include <linux/etherdevice.h>
19
20#include <linux/atomic.h>
21
22#include "u_ether.h"
23#include "u_ether_configfs.h"
24#include "u_rndis.h"
25#include "rndis.h"
26#include "configfs.h"
27
28/*
29 * This function is an RNDIS Ethernet port -- a Microsoft protocol that's
30 * been promoted instead of the standard CDC Ethernet.  The published RNDIS
31 * spec is ambiguous, incomplete, and needlessly complex.  Variants such as
32 * ActiveSync have even worse status in terms of specification.
33 *
34 * In short:  it's a protocol controlled by (and for) Microsoft, not for an
35 * Open ecosystem or markets.  Linux supports it *only* because Microsoft
36 * doesn't support the CDC Ethernet standard.
37 *
38 * The RNDIS data transfer model is complex, with multiple Ethernet packets
39 * per USB message, and out of band data.  The control model is built around
40 * what's essentially an "RNDIS RPC" protocol.  It's all wrapped in a CDC ACM
41 * (modem, not Ethernet) veneer, with those ACM descriptors being entirely
42 * useless (they're ignored).  RNDIS expects to be the only function in its
43 * configuration, so it's no real help if you need composite devices; and
44 * it expects to be the first configuration too.
45 *
46 * There is a single technical advantage of RNDIS over CDC Ethernet, if you
47 * discount the fluff that its RPC can be made to deliver: it doesn't need
48 * a NOP altsetting for the data interface.  That lets it work on some of the
49 * "so smart it's stupid" hardware which takes over configuration changes
50 * from the software, and adds restrictions like "no altsettings".
51 *
52 * Unfortunately MSFT's RNDIS drivers are buggy.  They hang or oops, and
53 * have all sorts of contrary-to-specification oddities that can prevent
54 * them from working sanely.  Since bugfixes (or accurate specs, letting
55 * Linux work around those bugs) are unlikely to ever come from MSFT, you
56 * may want to avoid using RNDIS on purely operational grounds.
57 *
58 * Omissions from the RNDIS 1.0 specification include:
59 *
60 *   - Power management ... references data that's scattered around lots
61 *     of other documentation, which is incorrect/incomplete there too.
62 *
63 *   - There are various undocumented protocol requirements, like the need
64 *     to send garbage in some control-OUT messages.
65 *
66 *   - MS-Windows drivers sometimes emit undocumented requests.
67 */
68
69struct f_rndis {
70	struct gether			port;
71	u8				ctrl_id, data_id;
72	u8				ethaddr[ETH_ALEN];
73	u32				vendorID;
74	const char			*manufacturer;
75	struct rndis_params		*params;
76
77	struct usb_ep			*notify;
78	struct usb_request		*notify_req;
79	atomic_t			notify_count;
80};
81
82static inline struct f_rndis *func_to_rndis(struct usb_function *f)
83{
84	return container_of(f, struct f_rndis, port.func);
85}
86
87/*-------------------------------------------------------------------------*/
88
89/*
90 */
91
92#define RNDIS_STATUS_INTERVAL_MS	32
93#define STATUS_BYTECOUNT		8	/* 8 bytes data */
94
95
96/* interface descriptor: */
97
98static struct usb_interface_descriptor rndis_control_intf = {
99	.bLength =		sizeof rndis_control_intf,
100	.bDescriptorType =	USB_DT_INTERFACE,
101
102	/* .bInterfaceNumber = DYNAMIC */
103	/* status endpoint is optional; this could be patched later */
104	.bNumEndpoints =	1,
105	.bInterfaceClass =	USB_CLASS_COMM,
106	.bInterfaceSubClass =   USB_CDC_SUBCLASS_ACM,
107	.bInterfaceProtocol =   USB_CDC_ACM_PROTO_VENDOR,
108	/* .iInterface = DYNAMIC */
109};
110
111static struct usb_cdc_header_desc header_desc = {
112	.bLength =		sizeof header_desc,
113	.bDescriptorType =	USB_DT_CS_INTERFACE,
114	.bDescriptorSubType =	USB_CDC_HEADER_TYPE,
115
116	.bcdCDC =		cpu_to_le16(0x0110),
117};
118
119static struct usb_cdc_call_mgmt_descriptor call_mgmt_descriptor = {
120	.bLength =		sizeof call_mgmt_descriptor,
121	.bDescriptorType =	USB_DT_CS_INTERFACE,
122	.bDescriptorSubType =	USB_CDC_CALL_MANAGEMENT_TYPE,
123
124	.bmCapabilities =	0x00,
125	.bDataInterface =	0x01,
126};
127
128static struct usb_cdc_acm_descriptor rndis_acm_descriptor = {
129	.bLength =		sizeof rndis_acm_descriptor,
130	.bDescriptorType =	USB_DT_CS_INTERFACE,
131	.bDescriptorSubType =	USB_CDC_ACM_TYPE,
132
133	.bmCapabilities =	0x00,
134};
135
136static struct usb_cdc_union_desc rndis_union_desc = {
137	.bLength =		sizeof(rndis_union_desc),
138	.bDescriptorType =	USB_DT_CS_INTERFACE,
139	.bDescriptorSubType =	USB_CDC_UNION_TYPE,
140	/* .bMasterInterface0 =	DYNAMIC */
141	/* .bSlaveInterface0 =	DYNAMIC */
142};
143
144/* the data interface has two bulk endpoints */
145
146static struct usb_interface_descriptor rndis_data_intf = {
147	.bLength =		sizeof rndis_data_intf,
148	.bDescriptorType =	USB_DT_INTERFACE,
149
150	/* .bInterfaceNumber = DYNAMIC */
151	.bNumEndpoints =	2,
152	.bInterfaceClass =	USB_CLASS_CDC_DATA,
153	.bInterfaceSubClass =	0,
154	.bInterfaceProtocol =	0,
155	/* .iInterface = DYNAMIC */
156};
157
158
159static struct usb_interface_assoc_descriptor
160rndis_iad_descriptor = {
161	.bLength =		sizeof rndis_iad_descriptor,
162	.bDescriptorType =	USB_DT_INTERFACE_ASSOCIATION,
163
164	.bFirstInterface =	0, /* XXX, hardcoded */
165	.bInterfaceCount = 	2,	// control + data
166	.bFunctionClass =	USB_CLASS_COMM,
167	.bFunctionSubClass =	USB_CDC_SUBCLASS_ETHERNET,
168	.bFunctionProtocol =	USB_CDC_PROTO_NONE,
169	/* .iFunction = DYNAMIC */
170};
171
172/* full speed support: */
173
174static struct usb_endpoint_descriptor fs_notify_desc = {
175	.bLength =		USB_DT_ENDPOINT_SIZE,
176	.bDescriptorType =	USB_DT_ENDPOINT,
177
178	.bEndpointAddress =	USB_DIR_IN,
179	.bmAttributes =		USB_ENDPOINT_XFER_INT,
180	.wMaxPacketSize =	cpu_to_le16(STATUS_BYTECOUNT),
181	.bInterval =		RNDIS_STATUS_INTERVAL_MS,
182};
183
184static struct usb_endpoint_descriptor fs_in_desc = {
185	.bLength =		USB_DT_ENDPOINT_SIZE,
186	.bDescriptorType =	USB_DT_ENDPOINT,
187
188	.bEndpointAddress =	USB_DIR_IN,
189	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
190};
191
192static struct usb_endpoint_descriptor fs_out_desc = {
193	.bLength =		USB_DT_ENDPOINT_SIZE,
194	.bDescriptorType =	USB_DT_ENDPOINT,
195
196	.bEndpointAddress =	USB_DIR_OUT,
197	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
198};
199
200static struct usb_descriptor_header *eth_fs_function[] = {
201	(struct usb_descriptor_header *) &rndis_iad_descriptor,
202
203	/* control interface matches ACM, not Ethernet */
204	(struct usb_descriptor_header *) &rndis_control_intf,
205	(struct usb_descriptor_header *) &header_desc,
206	(struct usb_descriptor_header *) &call_mgmt_descriptor,
207	(struct usb_descriptor_header *) &rndis_acm_descriptor,
208	(struct usb_descriptor_header *) &rndis_union_desc,
209	(struct usb_descriptor_header *) &fs_notify_desc,
210
211	/* data interface has no altsetting */
212	(struct usb_descriptor_header *) &rndis_data_intf,
213	(struct usb_descriptor_header *) &fs_in_desc,
214	(struct usb_descriptor_header *) &fs_out_desc,
215	NULL,
216};
217
218/* high speed support: */
219
220static struct usb_endpoint_descriptor hs_notify_desc = {
221	.bLength =		USB_DT_ENDPOINT_SIZE,
222	.bDescriptorType =	USB_DT_ENDPOINT,
223
224	.bEndpointAddress =	USB_DIR_IN,
225	.bmAttributes =		USB_ENDPOINT_XFER_INT,
226	.wMaxPacketSize =	cpu_to_le16(STATUS_BYTECOUNT),
227	.bInterval =		USB_MS_TO_HS_INTERVAL(RNDIS_STATUS_INTERVAL_MS)
228};
229
230static struct usb_endpoint_descriptor hs_in_desc = {
231	.bLength =		USB_DT_ENDPOINT_SIZE,
232	.bDescriptorType =	USB_DT_ENDPOINT,
233
234	.bEndpointAddress =	USB_DIR_IN,
235	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
236	.wMaxPacketSize =	cpu_to_le16(512),
237};
238
239static struct usb_endpoint_descriptor hs_out_desc = {
240	.bLength =		USB_DT_ENDPOINT_SIZE,
241	.bDescriptorType =	USB_DT_ENDPOINT,
242
243	.bEndpointAddress =	USB_DIR_OUT,
244	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
245	.wMaxPacketSize =	cpu_to_le16(512),
246};
247
248static struct usb_descriptor_header *eth_hs_function[] = {
249	(struct usb_descriptor_header *) &rndis_iad_descriptor,
250
251	/* control interface matches ACM, not Ethernet */
252	(struct usb_descriptor_header *) &rndis_control_intf,
253	(struct usb_descriptor_header *) &header_desc,
254	(struct usb_descriptor_header *) &call_mgmt_descriptor,
255	(struct usb_descriptor_header *) &rndis_acm_descriptor,
256	(struct usb_descriptor_header *) &rndis_union_desc,
257	(struct usb_descriptor_header *) &hs_notify_desc,
258
259	/* data interface has no altsetting */
260	(struct usb_descriptor_header *) &rndis_data_intf,
261	(struct usb_descriptor_header *) &hs_in_desc,
262	(struct usb_descriptor_header *) &hs_out_desc,
263	NULL,
264};
265
266/* super speed support: */
267
268static struct usb_endpoint_descriptor ss_notify_desc = {
269	.bLength =		USB_DT_ENDPOINT_SIZE,
270	.bDescriptorType =	USB_DT_ENDPOINT,
271
272	.bEndpointAddress =	USB_DIR_IN,
273	.bmAttributes =		USB_ENDPOINT_XFER_INT,
274	.wMaxPacketSize =	cpu_to_le16(STATUS_BYTECOUNT),
275	.bInterval =		USB_MS_TO_HS_INTERVAL(RNDIS_STATUS_INTERVAL_MS)
276};
277
278static struct usb_ss_ep_comp_descriptor ss_intr_comp_desc = {
279	.bLength =		sizeof ss_intr_comp_desc,
280	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
281
282	/* the following 3 values can be tweaked if necessary */
283	/* .bMaxBurst =		0, */
284	/* .bmAttributes =	0, */
285	.wBytesPerInterval =	cpu_to_le16(STATUS_BYTECOUNT),
286};
287
288static struct usb_endpoint_descriptor ss_in_desc = {
289	.bLength =		USB_DT_ENDPOINT_SIZE,
290	.bDescriptorType =	USB_DT_ENDPOINT,
291
292	.bEndpointAddress =	USB_DIR_IN,
293	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
294	.wMaxPacketSize =	cpu_to_le16(1024),
295};
296
297static struct usb_endpoint_descriptor ss_out_desc = {
298	.bLength =		USB_DT_ENDPOINT_SIZE,
299	.bDescriptorType =	USB_DT_ENDPOINT,
300
301	.bEndpointAddress =	USB_DIR_OUT,
302	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
303	.wMaxPacketSize =	cpu_to_le16(1024),
304};
305
306static struct usb_ss_ep_comp_descriptor ss_bulk_comp_desc = {
307	.bLength =		sizeof ss_bulk_comp_desc,
308	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
309
310	/* the following 2 values can be tweaked if necessary */
311	/* .bMaxBurst =		0, */
312	/* .bmAttributes =	0, */
313};
314
315static struct usb_descriptor_header *eth_ss_function[] = {
316	(struct usb_descriptor_header *) &rndis_iad_descriptor,
317
318	/* control interface matches ACM, not Ethernet */
319	(struct usb_descriptor_header *) &rndis_control_intf,
320	(struct usb_descriptor_header *) &header_desc,
321	(struct usb_descriptor_header *) &call_mgmt_descriptor,
322	(struct usb_descriptor_header *) &rndis_acm_descriptor,
323	(struct usb_descriptor_header *) &rndis_union_desc,
324	(struct usb_descriptor_header *) &ss_notify_desc,
325	(struct usb_descriptor_header *) &ss_intr_comp_desc,
326
327	/* data interface has no altsetting */
328	(struct usb_descriptor_header *) &rndis_data_intf,
329	(struct usb_descriptor_header *) &ss_in_desc,
330	(struct usb_descriptor_header *) &ss_bulk_comp_desc,
331	(struct usb_descriptor_header *) &ss_out_desc,
332	(struct usb_descriptor_header *) &ss_bulk_comp_desc,
333	NULL,
334};
335
336/* string descriptors: */
337
338static struct usb_string rndis_string_defs[] = {
339	[0].s = "RNDIS Communications Control",
340	[1].s = "RNDIS Ethernet Data",
341	[2].s = "RNDIS",
342	{  } /* end of list */
343};
344
345static struct usb_gadget_strings rndis_string_table = {
346	.language =		0x0409,	/* en-us */
347	.strings =		rndis_string_defs,
348};
349
350static struct usb_gadget_strings *rndis_strings[] = {
351	&rndis_string_table,
352	NULL,
353};
354
355/*-------------------------------------------------------------------------*/
356
357static struct sk_buff *rndis_add_header(struct gether *port,
358					struct sk_buff *skb)
359{
360	struct sk_buff *skb2;
361
362	if (!skb)
363		return NULL;
364
365	skb2 = skb_realloc_headroom(skb, sizeof(struct rndis_packet_msg_type));
366	rndis_add_hdr(skb2);
367
368	dev_kfree_skb(skb);
369	return skb2;
370}
371
372static void rndis_response_available(void *_rndis)
373{
374	struct f_rndis			*rndis = _rndis;
375	struct usb_request		*req = rndis->notify_req;
376	struct usb_composite_dev	*cdev = rndis->port.func.config->cdev;
377	__le32				*data = req->buf;
378	int				status;
379
380	if (atomic_inc_return(&rndis->notify_count) != 1)
381		return;
382
383	/* Send RNDIS RESPONSE_AVAILABLE notification; a
384	 * USB_CDC_NOTIFY_RESPONSE_AVAILABLE "should" work too
385	 *
386	 * This is the only notification defined by RNDIS.
387	 */
388	data[0] = cpu_to_le32(1);
389	data[1] = cpu_to_le32(0);
390
391	status = usb_ep_queue(rndis->notify, req, GFP_ATOMIC);
392	if (status) {
393		atomic_dec(&rndis->notify_count);
394		DBG(cdev, "notify/0 --> %d\n", status);
395	}
396}
397
398static void rndis_response_complete(struct usb_ep *ep, struct usb_request *req)
399{
400	struct f_rndis			*rndis = req->context;
401	struct usb_composite_dev	*cdev = rndis->port.func.config->cdev;
402	int				status = req->status;
403
404	/* after TX:
405	 *  - USB_CDC_GET_ENCAPSULATED_RESPONSE (ep0/control)
406	 *  - RNDIS_RESPONSE_AVAILABLE (status/irq)
407	 */
408	switch (status) {
409	case -ECONNRESET:
410	case -ESHUTDOWN:
411		/* connection gone */
412		atomic_set(&rndis->notify_count, 0);
413		break;
414	default:
415		DBG(cdev, "RNDIS %s response error %d, %d/%d\n",
416			ep->name, status,
417			req->actual, req->length);
418		fallthrough;
419	case 0:
420		if (ep != rndis->notify)
421			break;
422
423		/* handle multiple pending RNDIS_RESPONSE_AVAILABLE
424		 * notifications by resending until we're done
425		 */
426		if (atomic_dec_and_test(&rndis->notify_count))
427			break;
428		status = usb_ep_queue(rndis->notify, req, GFP_ATOMIC);
429		if (status) {
430			atomic_dec(&rndis->notify_count);
431			DBG(cdev, "notify/1 --> %d\n", status);
432		}
433		break;
434	}
435}
436
437static void rndis_command_complete(struct usb_ep *ep, struct usb_request *req)
438{
439	struct f_rndis			*rndis = req->context;
440	int				status;
441
442	/* received RNDIS command from USB_CDC_SEND_ENCAPSULATED_COMMAND */
443//	spin_lock(&dev->lock);
444	status = rndis_msg_parser(rndis->params, (u8 *) req->buf);
445	if (status < 0)
446		pr_err("RNDIS command error %d, %d/%d\n",
447			status, req->actual, req->length);
448//	spin_unlock(&dev->lock);
449}
450
451static int
452rndis_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
453{
454	struct f_rndis		*rndis = func_to_rndis(f);
455	struct usb_composite_dev *cdev = f->config->cdev;
456	struct usb_request	*req = cdev->req;
457	int			value = -EOPNOTSUPP;
458	u16			w_index = le16_to_cpu(ctrl->wIndex);
459	u16			w_value = le16_to_cpu(ctrl->wValue);
460	u16			w_length = le16_to_cpu(ctrl->wLength);
461
462	/* composite driver infrastructure handles everything except
463	 * CDC class messages; interface activation uses set_alt().
464	 */
465	switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
466
467	/* RNDIS uses the CDC command encapsulation mechanism to implement
468	 * an RPC scheme, with much getting/setting of attributes by OID.
469	 */
470	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
471			| USB_CDC_SEND_ENCAPSULATED_COMMAND:
472		if (w_value || w_index != rndis->ctrl_id)
473			goto invalid;
474		/* read the request; process it later */
475		value = w_length;
476		req->complete = rndis_command_complete;
477		req->context = rndis;
478		/* later, rndis_response_available() sends a notification */
479		break;
480
481	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
482			| USB_CDC_GET_ENCAPSULATED_RESPONSE:
483		if (w_value || w_index != rndis->ctrl_id)
484			goto invalid;
485		else {
486			u8 *buf;
487			u32 n;
488
489			/* return the result */
490			buf = rndis_get_next_response(rndis->params, &n);
491			if (buf) {
492				memcpy(req->buf, buf, n);
493				req->complete = rndis_response_complete;
494				req->context = rndis;
495				rndis_free_response(rndis->params, buf);
496				value = n;
497			}
498			/* else stalls ... spec says to avoid that */
499		}
500		break;
501
502	default:
503invalid:
504		VDBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
505			ctrl->bRequestType, ctrl->bRequest,
506			w_value, w_index, w_length);
507	}
508
509	/* respond with data transfer or status phase? */
510	if (value >= 0) {
511		DBG(cdev, "rndis req%02x.%02x v%04x i%04x l%d\n",
512			ctrl->bRequestType, ctrl->bRequest,
513			w_value, w_index, w_length);
514		req->zero = (value < w_length);
515		req->length = value;
516		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
517		if (value < 0)
518			ERROR(cdev, "rndis response on err %d\n", value);
519	}
520
521	/* device either stalls (value < 0) or reports success */
522	return value;
523}
524
525
526static int rndis_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
527{
528	struct f_rndis		*rndis = func_to_rndis(f);
529	struct usb_composite_dev *cdev = f->config->cdev;
530
531	/* we know alt == 0 */
532
533	if (intf == rndis->ctrl_id) {
534		VDBG(cdev, "reset rndis control %d\n", intf);
535		usb_ep_disable(rndis->notify);
536
537		if (!rndis->notify->desc) {
538			VDBG(cdev, "init rndis ctrl %d\n", intf);
539			if (config_ep_by_speed(cdev->gadget, f, rndis->notify))
540				goto fail;
541		}
542		usb_ep_enable(rndis->notify);
543
544	} else if (intf == rndis->data_id) {
545		struct net_device	*net;
546
547		if (rndis->port.in_ep->enabled) {
548			DBG(cdev, "reset rndis\n");
549			gether_disconnect(&rndis->port);
550		}
551
552		if (!rndis->port.in_ep->desc || !rndis->port.out_ep->desc) {
553			DBG(cdev, "init rndis\n");
554			if (config_ep_by_speed(cdev->gadget, f,
555					       rndis->port.in_ep) ||
556			    config_ep_by_speed(cdev->gadget, f,
557					       rndis->port.out_ep)) {
558				rndis->port.in_ep->desc = NULL;
559				rndis->port.out_ep->desc = NULL;
560				goto fail;
561			}
562		}
563
564		/* Avoid ZLPs; they can be troublesome. */
565		rndis->port.is_zlp_ok = false;
566
567		/* RNDIS should be in the "RNDIS uninitialized" state,
568		 * either never activated or after rndis_uninit().
569		 *
570		 * We don't want data to flow here until a nonzero packet
571		 * filter is set, at which point it enters "RNDIS data
572		 * initialized" state ... but we do want the endpoints
573		 * to be activated.  It's a strange little state.
574		 *
575		 * REVISIT the RNDIS gadget code has done this wrong for a
576		 * very long time.  We need another call to the link layer
577		 * code -- gether_updown(...bool) maybe -- to do it right.
578		 */
579		rndis->port.cdc_filter = 0;
580
581		DBG(cdev, "RNDIS RX/TX early activation ... \n");
582		net = gether_connect(&rndis->port);
583		if (IS_ERR(net))
584			return PTR_ERR(net);
585
586		rndis_set_param_dev(rndis->params, net,
587				&rndis->port.cdc_filter);
588	} else
589		goto fail;
590
591	return 0;
592fail:
593	return -EINVAL;
594}
595
596static void rndis_disable(struct usb_function *f)
597{
598	struct f_rndis		*rndis = func_to_rndis(f);
599	struct usb_composite_dev *cdev = f->config->cdev;
600
601	if (!rndis->notify->enabled)
602		return;
603
604	DBG(cdev, "rndis deactivated\n");
605
606	rndis_uninit(rndis->params);
607	gether_disconnect(&rndis->port);
608
609	usb_ep_disable(rndis->notify);
610	rndis->notify->desc = NULL;
611}
612
613/*-------------------------------------------------------------------------*/
614
615/*
616 * This isn't quite the same mechanism as CDC Ethernet, since the
617 * notification scheme passes less data, but the same set of link
618 * states must be tested.  A key difference is that altsettings are
619 * not used to tell whether the link should send packets or not.
620 */
621
622static void rndis_open(struct gether *geth)
623{
624	struct f_rndis		*rndis = func_to_rndis(&geth->func);
625	struct usb_composite_dev *cdev = geth->func.config->cdev;
626
627	DBG(cdev, "%s\n", __func__);
628
629	rndis_set_param_medium(rndis->params, RNDIS_MEDIUM_802_3,
630				gether_bitrate(cdev->gadget) / 100);
631	rndis_signal_connect(rndis->params);
632}
633
634static void rndis_close(struct gether *geth)
635{
636	struct f_rndis		*rndis = func_to_rndis(&geth->func);
637
638	DBG(geth->func.config->cdev, "%s\n", __func__);
639
640	rndis_set_param_medium(rndis->params, RNDIS_MEDIUM_802_3, 0);
641	rndis_signal_disconnect(rndis->params);
642}
643
644/*-------------------------------------------------------------------------*/
645
646/* Some controllers can't support RNDIS ... */
647static inline bool can_support_rndis(struct usb_configuration *c)
648{
649	/* everything else is *presumably* fine */
650	return true;
651}
652
653/* ethernet function driver setup/binding */
654
655static int
656rndis_bind(struct usb_configuration *c, struct usb_function *f)
657{
658	struct usb_composite_dev *cdev = c->cdev;
659	struct f_rndis		*rndis = func_to_rndis(f);
660	struct usb_string	*us;
661	int			status;
662	struct usb_ep		*ep;
663
664	struct f_rndis_opts *rndis_opts;
665
666	if (!can_support_rndis(c))
667		return -EINVAL;
668
669	rndis_opts = container_of(f->fi, struct f_rndis_opts, func_inst);
670
671	if (cdev->use_os_string) {
672		f->os_desc_table = kzalloc(sizeof(*f->os_desc_table),
673					   GFP_KERNEL);
674		if (!f->os_desc_table)
675			return -ENOMEM;
676		f->os_desc_n = 1;
677		f->os_desc_table[0].os_desc = &rndis_opts->rndis_os_desc;
678	}
679
680	rndis_iad_descriptor.bFunctionClass = rndis_opts->class;
681	rndis_iad_descriptor.bFunctionSubClass = rndis_opts->subclass;
682	rndis_iad_descriptor.bFunctionProtocol = rndis_opts->protocol;
683
684	/*
685	 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
686	 * configurations are bound in sequence with list_for_each_entry,
687	 * in each configuration its functions are bound in sequence
688	 * with list_for_each_entry, so we assume no race condition
689	 * with regard to rndis_opts->bound access
690	 */
691	if (!rndis_opts->bound) {
692		gether_set_gadget(rndis_opts->net, cdev->gadget);
693		status = gether_register_netdev(rndis_opts->net);
694		if (status)
695			goto fail;
696		rndis_opts->bound = true;
697	}
698
699	us = usb_gstrings_attach(cdev, rndis_strings,
700				 ARRAY_SIZE(rndis_string_defs));
701	if (IS_ERR(us)) {
702		status = PTR_ERR(us);
703		goto fail;
704	}
705	rndis_control_intf.iInterface = us[0].id;
706	rndis_data_intf.iInterface = us[1].id;
707	rndis_iad_descriptor.iFunction = us[2].id;
708
709	/* allocate instance-specific interface IDs */
710	status = usb_interface_id(c, f);
711	if (status < 0)
712		goto fail;
713	rndis->ctrl_id = status;
714	rndis_iad_descriptor.bFirstInterface = status;
715
716	rndis_control_intf.bInterfaceNumber = status;
717	rndis_union_desc.bMasterInterface0 = status;
718
719	if (cdev->use_os_string)
720		f->os_desc_table[0].if_id =
721			rndis_iad_descriptor.bFirstInterface;
722
723	status = usb_interface_id(c, f);
724	if (status < 0)
725		goto fail;
726	rndis->data_id = status;
727
728	rndis_data_intf.bInterfaceNumber = status;
729	rndis_union_desc.bSlaveInterface0 = status;
730
731	status = -ENODEV;
732
733	/* allocate instance-specific endpoints */
734	ep = usb_ep_autoconfig(cdev->gadget, &fs_in_desc);
735	if (!ep)
736		goto fail;
737	rndis->port.in_ep = ep;
738
739	ep = usb_ep_autoconfig(cdev->gadget, &fs_out_desc);
740	if (!ep)
741		goto fail;
742	rndis->port.out_ep = ep;
743
744	/* NOTE:  a status/notification endpoint is, strictly speaking,
745	 * optional.  We don't treat it that way though!  It's simpler,
746	 * and some newer profiles don't treat it as optional.
747	 */
748	ep = usb_ep_autoconfig(cdev->gadget, &fs_notify_desc);
749	if (!ep)
750		goto fail;
751	rndis->notify = ep;
752
753	status = -ENOMEM;
754
755	/* allocate notification request and buffer */
756	rndis->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
757	if (!rndis->notify_req)
758		goto fail;
759	rndis->notify_req->buf = kmalloc(STATUS_BYTECOUNT, GFP_KERNEL);
760	if (!rndis->notify_req->buf)
761		goto fail;
762	rndis->notify_req->length = STATUS_BYTECOUNT;
763	rndis->notify_req->context = rndis;
764	rndis->notify_req->complete = rndis_response_complete;
765
766	/* support all relevant hardware speeds... we expect that when
767	 * hardware is dual speed, all bulk-capable endpoints work at
768	 * both speeds
769	 */
770	hs_in_desc.bEndpointAddress = fs_in_desc.bEndpointAddress;
771	hs_out_desc.bEndpointAddress = fs_out_desc.bEndpointAddress;
772	hs_notify_desc.bEndpointAddress = fs_notify_desc.bEndpointAddress;
773
774	ss_in_desc.bEndpointAddress = fs_in_desc.bEndpointAddress;
775	ss_out_desc.bEndpointAddress = fs_out_desc.bEndpointAddress;
776	ss_notify_desc.bEndpointAddress = fs_notify_desc.bEndpointAddress;
777
778	status = usb_assign_descriptors(f, eth_fs_function, eth_hs_function,
779			eth_ss_function, eth_ss_function);
780	if (status)
781		goto fail;
782
783	rndis->port.open = rndis_open;
784	rndis->port.close = rndis_close;
785
786	rndis_set_param_medium(rndis->params, RNDIS_MEDIUM_802_3, 0);
787	rndis_set_host_mac(rndis->params, rndis->ethaddr);
788
789	if (rndis->manufacturer && rndis->vendorID &&
790			rndis_set_param_vendor(rndis->params, rndis->vendorID,
791					       rndis->manufacturer)) {
792		status = -EINVAL;
793		goto fail_free_descs;
794	}
795
796	/* NOTE:  all that is done without knowing or caring about
797	 * the network link ... which is unavailable to this code
798	 * until we're activated via set_alt().
799	 */
800
801	DBG(cdev, "RNDIS: IN/%s OUT/%s NOTIFY/%s\n",
802			rndis->port.in_ep->name, rndis->port.out_ep->name,
803			rndis->notify->name);
804	return 0;
805
806fail_free_descs:
807	usb_free_all_descriptors(f);
808fail:
809	kfree(f->os_desc_table);
810	f->os_desc_n = 0;
811
812	if (rndis->notify_req) {
813		kfree(rndis->notify_req->buf);
814		usb_ep_free_request(rndis->notify, rndis->notify_req);
815	}
816
817	ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
818
819	return status;
820}
821
822void rndis_borrow_net(struct usb_function_instance *f, struct net_device *net)
823{
824	struct f_rndis_opts *opts;
825
826	opts = container_of(f, struct f_rndis_opts, func_inst);
827	if (opts->bound)
828		gether_cleanup(netdev_priv(opts->net));
829	else
830		free_netdev(opts->net);
831	opts->borrowed_net = opts->bound = true;
832	opts->net = net;
833}
834EXPORT_SYMBOL_GPL(rndis_borrow_net);
835
836static inline struct f_rndis_opts *to_f_rndis_opts(struct config_item *item)
837{
838	return container_of(to_config_group(item), struct f_rndis_opts,
839			    func_inst.group);
840}
841
842/* f_rndis_item_ops */
843USB_ETHERNET_CONFIGFS_ITEM(rndis);
844
845/* f_rndis_opts_dev_addr */
846USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(rndis);
847
848/* f_rndis_opts_host_addr */
849USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(rndis);
850
851/* f_rndis_opts_qmult */
852USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(rndis);
853
854/* f_rndis_opts_ifname */
855USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(rndis);
856
857/* f_rndis_opts_class */
858USB_ETHER_CONFIGFS_ITEM_ATTR_U8_RW(rndis, class);
859
860/* f_rndis_opts_subclass */
861USB_ETHER_CONFIGFS_ITEM_ATTR_U8_RW(rndis, subclass);
862
863/* f_rndis_opts_protocol */
864USB_ETHER_CONFIGFS_ITEM_ATTR_U8_RW(rndis, protocol);
865
866static struct configfs_attribute *rndis_attrs[] = {
867	&rndis_opts_attr_dev_addr,
868	&rndis_opts_attr_host_addr,
869	&rndis_opts_attr_qmult,
870	&rndis_opts_attr_ifname,
871	&rndis_opts_attr_class,
872	&rndis_opts_attr_subclass,
873	&rndis_opts_attr_protocol,
874	NULL,
875};
876
877static const struct config_item_type rndis_func_type = {
878	.ct_item_ops	= &rndis_item_ops,
879	.ct_attrs	= rndis_attrs,
880	.ct_owner	= THIS_MODULE,
881};
882
883static void rndis_free_inst(struct usb_function_instance *f)
884{
885	struct f_rndis_opts *opts;
886
887	opts = container_of(f, struct f_rndis_opts, func_inst);
888	if (!opts->borrowed_net) {
889		if (opts->bound)
890			gether_cleanup(netdev_priv(opts->net));
891		else
892			free_netdev(opts->net);
893	}
894
895	kfree(opts->rndis_interf_group);	/* single VLA chunk */
896	kfree(opts);
897}
898
899static struct usb_function_instance *rndis_alloc_inst(void)
900{
901	struct f_rndis_opts *opts;
902	struct usb_os_desc *descs[1];
903	char *names[1];
904	struct config_group *rndis_interf_group;
905
906	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
907	if (!opts)
908		return ERR_PTR(-ENOMEM);
909	opts->rndis_os_desc.ext_compat_id = opts->rndis_ext_compat_id;
910
911	mutex_init(&opts->lock);
912	opts->func_inst.free_func_inst = rndis_free_inst;
913	opts->net = gether_setup_default();
914	if (IS_ERR(opts->net)) {
915		struct net_device *net = opts->net;
916		kfree(opts);
917		return ERR_CAST(net);
918	}
919	INIT_LIST_HEAD(&opts->rndis_os_desc.ext_prop);
920
921	opts->class = rndis_iad_descriptor.bFunctionClass;
922	opts->subclass = rndis_iad_descriptor.bFunctionSubClass;
923	opts->protocol = rndis_iad_descriptor.bFunctionProtocol;
924
925	descs[0] = &opts->rndis_os_desc;
926	names[0] = "rndis";
927	config_group_init_type_name(&opts->func_inst.group, "",
928				    &rndis_func_type);
929	rndis_interf_group =
930		usb_os_desc_prepare_interf_dir(&opts->func_inst.group, 1, descs,
931					       names, THIS_MODULE);
932	if (IS_ERR(rndis_interf_group)) {
933		rndis_free_inst(&opts->func_inst);
934		return ERR_CAST(rndis_interf_group);
935	}
936	opts->rndis_interf_group = rndis_interf_group;
937
938	return &opts->func_inst;
939}
940
941static void rndis_free(struct usb_function *f)
942{
943	struct f_rndis *rndis;
944	struct f_rndis_opts *opts;
945
946	rndis = func_to_rndis(f);
947	rndis_deregister(rndis->params);
948	opts = container_of(f->fi, struct f_rndis_opts, func_inst);
949	kfree(rndis);
950	mutex_lock(&opts->lock);
951	opts->refcnt--;
952	mutex_unlock(&opts->lock);
953}
954
955static void rndis_unbind(struct usb_configuration *c, struct usb_function *f)
956{
957	struct f_rndis		*rndis = func_to_rndis(f);
958
959	kfree(f->os_desc_table);
960	f->os_desc_n = 0;
961	usb_free_all_descriptors(f);
962
963	kfree(rndis->notify_req->buf);
964	usb_ep_free_request(rndis->notify, rndis->notify_req);
965}
966
967static struct usb_function *rndis_alloc(struct usb_function_instance *fi)
968{
969	struct f_rndis	*rndis;
970	struct f_rndis_opts *opts;
971	struct rndis_params *params;
972
973	/* allocate and initialize one new instance */
974	rndis = kzalloc(sizeof(*rndis), GFP_KERNEL);
975	if (!rndis)
976		return ERR_PTR(-ENOMEM);
977
978	opts = container_of(fi, struct f_rndis_opts, func_inst);
979	mutex_lock(&opts->lock);
980	opts->refcnt++;
981
982	gether_get_host_addr_u8(opts->net, rndis->ethaddr);
983	rndis->vendorID = opts->vendor_id;
984	rndis->manufacturer = opts->manufacturer;
985
986	rndis->port.ioport = netdev_priv(opts->net);
987	mutex_unlock(&opts->lock);
988	/* RNDIS activates when the host changes this filter */
989	rndis->port.cdc_filter = 0;
990
991	/* RNDIS has special (and complex) framing */
992	rndis->port.header_len = sizeof(struct rndis_packet_msg_type);
993	rndis->port.wrap = rndis_add_header;
994	rndis->port.unwrap = rndis_rm_hdr;
995
996	rndis->port.func.name = "rndis";
997	/* descriptors are per-instance copies */
998	rndis->port.func.bind = rndis_bind;
999	rndis->port.func.unbind = rndis_unbind;
1000	rndis->port.func.set_alt = rndis_set_alt;
1001	rndis->port.func.setup = rndis_setup;
1002	rndis->port.func.disable = rndis_disable;
1003	rndis->port.func.free_func = rndis_free;
1004
1005	params = rndis_register(rndis_response_available, rndis);
1006	if (IS_ERR(params)) {
1007		kfree(rndis);
1008		return ERR_CAST(params);
1009	}
1010	rndis->params = params;
1011
1012	return &rndis->port.func;
1013}
1014
1015DECLARE_USB_FUNCTION_INIT(rndis, rndis_alloc_inst, rndis_alloc);
1016MODULE_LICENSE("GPL");
1017MODULE_AUTHOR("David Brownell");
1018