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