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v6.8
   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");
v5.9
   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/* peak (theoretical) bulk transfer rate in bits-per-second */
  88static unsigned int bitrate(struct usb_gadget *g)
  89{
  90	if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
  91		return 13 * 1024 * 8 * 1000 * 8;
  92	else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
  93		return 13 * 512 * 8 * 1000 * 8;
  94	else
  95		return 19 * 64 * 1 * 1000 * 8;
  96}
  97
  98/*-------------------------------------------------------------------------*/
  99
 100/*
 101 */
 102
 103#define RNDIS_STATUS_INTERVAL_MS	32
 104#define STATUS_BYTECOUNT		8	/* 8 bytes data */
 105
 106
 107/* interface descriptor: */
 108
 109static struct usb_interface_descriptor rndis_control_intf = {
 110	.bLength =		sizeof rndis_control_intf,
 111	.bDescriptorType =	USB_DT_INTERFACE,
 112
 113	/* .bInterfaceNumber = DYNAMIC */
 114	/* status endpoint is optional; this could be patched later */
 115	.bNumEndpoints =	1,
 116	.bInterfaceClass =	USB_CLASS_COMM,
 117	.bInterfaceSubClass =   USB_CDC_SUBCLASS_ACM,
 118	.bInterfaceProtocol =   USB_CDC_ACM_PROTO_VENDOR,
 119	/* .iInterface = DYNAMIC */
 120};
 121
 122static struct usb_cdc_header_desc header_desc = {
 123	.bLength =		sizeof header_desc,
 124	.bDescriptorType =	USB_DT_CS_INTERFACE,
 125	.bDescriptorSubType =	USB_CDC_HEADER_TYPE,
 126
 127	.bcdCDC =		cpu_to_le16(0x0110),
 128};
 129
 130static struct usb_cdc_call_mgmt_descriptor call_mgmt_descriptor = {
 131	.bLength =		sizeof call_mgmt_descriptor,
 132	.bDescriptorType =	USB_DT_CS_INTERFACE,
 133	.bDescriptorSubType =	USB_CDC_CALL_MANAGEMENT_TYPE,
 134
 135	.bmCapabilities =	0x00,
 136	.bDataInterface =	0x01,
 137};
 138
 139static struct usb_cdc_acm_descriptor rndis_acm_descriptor = {
 140	.bLength =		sizeof rndis_acm_descriptor,
 141	.bDescriptorType =	USB_DT_CS_INTERFACE,
 142	.bDescriptorSubType =	USB_CDC_ACM_TYPE,
 143
 144	.bmCapabilities =	0x00,
 145};
 146
 147static struct usb_cdc_union_desc rndis_union_desc = {
 148	.bLength =		sizeof(rndis_union_desc),
 149	.bDescriptorType =	USB_DT_CS_INTERFACE,
 150	.bDescriptorSubType =	USB_CDC_UNION_TYPE,
 151	/* .bMasterInterface0 =	DYNAMIC */
 152	/* .bSlaveInterface0 =	DYNAMIC */
 153};
 154
 155/* the data interface has two bulk endpoints */
 156
 157static struct usb_interface_descriptor rndis_data_intf = {
 158	.bLength =		sizeof rndis_data_intf,
 159	.bDescriptorType =	USB_DT_INTERFACE,
 160
 161	/* .bInterfaceNumber = DYNAMIC */
 162	.bNumEndpoints =	2,
 163	.bInterfaceClass =	USB_CLASS_CDC_DATA,
 164	.bInterfaceSubClass =	0,
 165	.bInterfaceProtocol =	0,
 166	/* .iInterface = DYNAMIC */
 167};
 168
 169
 170static struct usb_interface_assoc_descriptor
 171rndis_iad_descriptor = {
 172	.bLength =		sizeof rndis_iad_descriptor,
 173	.bDescriptorType =	USB_DT_INTERFACE_ASSOCIATION,
 174
 175	.bFirstInterface =	0, /* XXX, hardcoded */
 176	.bInterfaceCount = 	2,	// control + data
 177	.bFunctionClass =	USB_CLASS_COMM,
 178	.bFunctionSubClass =	USB_CDC_SUBCLASS_ETHERNET,
 179	.bFunctionProtocol =	USB_CDC_PROTO_NONE,
 180	/* .iFunction = DYNAMIC */
 181};
 182
 183/* full speed support: */
 184
 185static struct usb_endpoint_descriptor fs_notify_desc = {
 186	.bLength =		USB_DT_ENDPOINT_SIZE,
 187	.bDescriptorType =	USB_DT_ENDPOINT,
 188
 189	.bEndpointAddress =	USB_DIR_IN,
 190	.bmAttributes =		USB_ENDPOINT_XFER_INT,
 191	.wMaxPacketSize =	cpu_to_le16(STATUS_BYTECOUNT),
 192	.bInterval =		RNDIS_STATUS_INTERVAL_MS,
 193};
 194
 195static struct usb_endpoint_descriptor fs_in_desc = {
 196	.bLength =		USB_DT_ENDPOINT_SIZE,
 197	.bDescriptorType =	USB_DT_ENDPOINT,
 198
 199	.bEndpointAddress =	USB_DIR_IN,
 200	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
 201};
 202
 203static struct usb_endpoint_descriptor fs_out_desc = {
 204	.bLength =		USB_DT_ENDPOINT_SIZE,
 205	.bDescriptorType =	USB_DT_ENDPOINT,
 206
 207	.bEndpointAddress =	USB_DIR_OUT,
 208	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
 209};
 210
 211static struct usb_descriptor_header *eth_fs_function[] = {
 212	(struct usb_descriptor_header *) &rndis_iad_descriptor,
 213
 214	/* control interface matches ACM, not Ethernet */
 215	(struct usb_descriptor_header *) &rndis_control_intf,
 216	(struct usb_descriptor_header *) &header_desc,
 217	(struct usb_descriptor_header *) &call_mgmt_descriptor,
 218	(struct usb_descriptor_header *) &rndis_acm_descriptor,
 219	(struct usb_descriptor_header *) &rndis_union_desc,
 220	(struct usb_descriptor_header *) &fs_notify_desc,
 221
 222	/* data interface has no altsetting */
 223	(struct usb_descriptor_header *) &rndis_data_intf,
 224	(struct usb_descriptor_header *) &fs_in_desc,
 225	(struct usb_descriptor_header *) &fs_out_desc,
 226	NULL,
 227};
 228
 229/* high speed support: */
 230
 231static struct usb_endpoint_descriptor hs_notify_desc = {
 232	.bLength =		USB_DT_ENDPOINT_SIZE,
 233	.bDescriptorType =	USB_DT_ENDPOINT,
 234
 235	.bEndpointAddress =	USB_DIR_IN,
 236	.bmAttributes =		USB_ENDPOINT_XFER_INT,
 237	.wMaxPacketSize =	cpu_to_le16(STATUS_BYTECOUNT),
 238	.bInterval =		USB_MS_TO_HS_INTERVAL(RNDIS_STATUS_INTERVAL_MS)
 239};
 240
 241static struct usb_endpoint_descriptor hs_in_desc = {
 242	.bLength =		USB_DT_ENDPOINT_SIZE,
 243	.bDescriptorType =	USB_DT_ENDPOINT,
 244
 245	.bEndpointAddress =	USB_DIR_IN,
 246	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
 247	.wMaxPacketSize =	cpu_to_le16(512),
 248};
 249
 250static struct usb_endpoint_descriptor hs_out_desc = {
 251	.bLength =		USB_DT_ENDPOINT_SIZE,
 252	.bDescriptorType =	USB_DT_ENDPOINT,
 253
 254	.bEndpointAddress =	USB_DIR_OUT,
 255	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
 256	.wMaxPacketSize =	cpu_to_le16(512),
 257};
 258
 259static struct usb_descriptor_header *eth_hs_function[] = {
 260	(struct usb_descriptor_header *) &rndis_iad_descriptor,
 261
 262	/* control interface matches ACM, not Ethernet */
 263	(struct usb_descriptor_header *) &rndis_control_intf,
 264	(struct usb_descriptor_header *) &header_desc,
 265	(struct usb_descriptor_header *) &call_mgmt_descriptor,
 266	(struct usb_descriptor_header *) &rndis_acm_descriptor,
 267	(struct usb_descriptor_header *) &rndis_union_desc,
 268	(struct usb_descriptor_header *) &hs_notify_desc,
 269
 270	/* data interface has no altsetting */
 271	(struct usb_descriptor_header *) &rndis_data_intf,
 272	(struct usb_descriptor_header *) &hs_in_desc,
 273	(struct usb_descriptor_header *) &hs_out_desc,
 274	NULL,
 275};
 276
 277/* super speed support: */
 278
 279static struct usb_endpoint_descriptor ss_notify_desc = {
 280	.bLength =		USB_DT_ENDPOINT_SIZE,
 281	.bDescriptorType =	USB_DT_ENDPOINT,
 282
 283	.bEndpointAddress =	USB_DIR_IN,
 284	.bmAttributes =		USB_ENDPOINT_XFER_INT,
 285	.wMaxPacketSize =	cpu_to_le16(STATUS_BYTECOUNT),
 286	.bInterval =		USB_MS_TO_HS_INTERVAL(RNDIS_STATUS_INTERVAL_MS)
 287};
 288
 289static struct usb_ss_ep_comp_descriptor ss_intr_comp_desc = {
 290	.bLength =		sizeof ss_intr_comp_desc,
 291	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
 292
 293	/* the following 3 values can be tweaked if necessary */
 294	/* .bMaxBurst =		0, */
 295	/* .bmAttributes =	0, */
 296	.wBytesPerInterval =	cpu_to_le16(STATUS_BYTECOUNT),
 297};
 298
 299static struct usb_endpoint_descriptor ss_in_desc = {
 300	.bLength =		USB_DT_ENDPOINT_SIZE,
 301	.bDescriptorType =	USB_DT_ENDPOINT,
 302
 303	.bEndpointAddress =	USB_DIR_IN,
 304	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
 305	.wMaxPacketSize =	cpu_to_le16(1024),
 306};
 307
 308static struct usb_endpoint_descriptor ss_out_desc = {
 309	.bLength =		USB_DT_ENDPOINT_SIZE,
 310	.bDescriptorType =	USB_DT_ENDPOINT,
 311
 312	.bEndpointAddress =	USB_DIR_OUT,
 313	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
 314	.wMaxPacketSize =	cpu_to_le16(1024),
 315};
 316
 317static struct usb_ss_ep_comp_descriptor ss_bulk_comp_desc = {
 318	.bLength =		sizeof ss_bulk_comp_desc,
 319	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
 320
 321	/* the following 2 values can be tweaked if necessary */
 322	/* .bMaxBurst =		0, */
 323	/* .bmAttributes =	0, */
 324};
 325
 326static struct usb_descriptor_header *eth_ss_function[] = {
 327	(struct usb_descriptor_header *) &rndis_iad_descriptor,
 328
 329	/* control interface matches ACM, not Ethernet */
 330	(struct usb_descriptor_header *) &rndis_control_intf,
 331	(struct usb_descriptor_header *) &header_desc,
 332	(struct usb_descriptor_header *) &call_mgmt_descriptor,
 333	(struct usb_descriptor_header *) &rndis_acm_descriptor,
 334	(struct usb_descriptor_header *) &rndis_union_desc,
 335	(struct usb_descriptor_header *) &ss_notify_desc,
 336	(struct usb_descriptor_header *) &ss_intr_comp_desc,
 337
 338	/* data interface has no altsetting */
 339	(struct usb_descriptor_header *) &rndis_data_intf,
 340	(struct usb_descriptor_header *) &ss_in_desc,
 341	(struct usb_descriptor_header *) &ss_bulk_comp_desc,
 342	(struct usb_descriptor_header *) &ss_out_desc,
 343	(struct usb_descriptor_header *) &ss_bulk_comp_desc,
 344	NULL,
 345};
 346
 347/* string descriptors: */
 348
 349static struct usb_string rndis_string_defs[] = {
 350	[0].s = "RNDIS Communications Control",
 351	[1].s = "RNDIS Ethernet Data",
 352	[2].s = "RNDIS",
 353	{  } /* end of list */
 354};
 355
 356static struct usb_gadget_strings rndis_string_table = {
 357	.language =		0x0409,	/* en-us */
 358	.strings =		rndis_string_defs,
 359};
 360
 361static struct usb_gadget_strings *rndis_strings[] = {
 362	&rndis_string_table,
 363	NULL,
 364};
 365
 366/*-------------------------------------------------------------------------*/
 367
 368static struct sk_buff *rndis_add_header(struct gether *port,
 369					struct sk_buff *skb)
 370{
 371	struct sk_buff *skb2;
 372
 373	if (!skb)
 374		return NULL;
 375
 376	skb2 = skb_realloc_headroom(skb, sizeof(struct rndis_packet_msg_type));
 377	rndis_add_hdr(skb2);
 378
 379	dev_kfree_skb(skb);
 380	return skb2;
 381}
 382
 383static void rndis_response_available(void *_rndis)
 384{
 385	struct f_rndis			*rndis = _rndis;
 386	struct usb_request		*req = rndis->notify_req;
 387	struct usb_composite_dev	*cdev = rndis->port.func.config->cdev;
 388	__le32				*data = req->buf;
 389	int				status;
 390
 391	if (atomic_inc_return(&rndis->notify_count) != 1)
 392		return;
 393
 394	/* Send RNDIS RESPONSE_AVAILABLE notification; a
 395	 * USB_CDC_NOTIFY_RESPONSE_AVAILABLE "should" work too
 396	 *
 397	 * This is the only notification defined by RNDIS.
 398	 */
 399	data[0] = cpu_to_le32(1);
 400	data[1] = cpu_to_le32(0);
 401
 402	status = usb_ep_queue(rndis->notify, req, GFP_ATOMIC);
 403	if (status) {
 404		atomic_dec(&rndis->notify_count);
 405		DBG(cdev, "notify/0 --> %d\n", status);
 406	}
 407}
 408
 409static void rndis_response_complete(struct usb_ep *ep, struct usb_request *req)
 410{
 411	struct f_rndis			*rndis = req->context;
 412	struct usb_composite_dev	*cdev = rndis->port.func.config->cdev;
 413	int				status = req->status;
 414
 415	/* after TX:
 416	 *  - USB_CDC_GET_ENCAPSULATED_RESPONSE (ep0/control)
 417	 *  - RNDIS_RESPONSE_AVAILABLE (status/irq)
 418	 */
 419	switch (status) {
 420	case -ECONNRESET:
 421	case -ESHUTDOWN:
 422		/* connection gone */
 423		atomic_set(&rndis->notify_count, 0);
 424		break;
 425	default:
 426		DBG(cdev, "RNDIS %s response error %d, %d/%d\n",
 427			ep->name, status,
 428			req->actual, req->length);
 429		fallthrough;
 430	case 0:
 431		if (ep != rndis->notify)
 432			break;
 433
 434		/* handle multiple pending RNDIS_RESPONSE_AVAILABLE
 435		 * notifications by resending until we're done
 436		 */
 437		if (atomic_dec_and_test(&rndis->notify_count))
 438			break;
 439		status = usb_ep_queue(rndis->notify, req, GFP_ATOMIC);
 440		if (status) {
 441			atomic_dec(&rndis->notify_count);
 442			DBG(cdev, "notify/1 --> %d\n", status);
 443		}
 444		break;
 445	}
 446}
 447
 448static void rndis_command_complete(struct usb_ep *ep, struct usb_request *req)
 449{
 450	struct f_rndis			*rndis = req->context;
 451	int				status;
 452
 453	/* received RNDIS command from USB_CDC_SEND_ENCAPSULATED_COMMAND */
 454//	spin_lock(&dev->lock);
 455	status = rndis_msg_parser(rndis->params, (u8 *) req->buf);
 456	if (status < 0)
 457		pr_err("RNDIS command error %d, %d/%d\n",
 458			status, req->actual, req->length);
 459//	spin_unlock(&dev->lock);
 460}
 461
 462static int
 463rndis_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 464{
 465	struct f_rndis		*rndis = func_to_rndis(f);
 466	struct usb_composite_dev *cdev = f->config->cdev;
 467	struct usb_request	*req = cdev->req;
 468	int			value = -EOPNOTSUPP;
 469	u16			w_index = le16_to_cpu(ctrl->wIndex);
 470	u16			w_value = le16_to_cpu(ctrl->wValue);
 471	u16			w_length = le16_to_cpu(ctrl->wLength);
 472
 473	/* composite driver infrastructure handles everything except
 474	 * CDC class messages; interface activation uses set_alt().
 475	 */
 476	switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 477
 478	/* RNDIS uses the CDC command encapsulation mechanism to implement
 479	 * an RPC scheme, with much getting/setting of attributes by OID.
 480	 */
 481	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 482			| USB_CDC_SEND_ENCAPSULATED_COMMAND:
 483		if (w_value || w_index != rndis->ctrl_id)
 484			goto invalid;
 485		/* read the request; process it later */
 486		value = w_length;
 487		req->complete = rndis_command_complete;
 488		req->context = rndis;
 489		/* later, rndis_response_available() sends a notification */
 490		break;
 491
 492	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 493			| USB_CDC_GET_ENCAPSULATED_RESPONSE:
 494		if (w_value || w_index != rndis->ctrl_id)
 495			goto invalid;
 496		else {
 497			u8 *buf;
 498			u32 n;
 499
 500			/* return the result */
 501			buf = rndis_get_next_response(rndis->params, &n);
 502			if (buf) {
 503				memcpy(req->buf, buf, n);
 504				req->complete = rndis_response_complete;
 505				req->context = rndis;
 506				rndis_free_response(rndis->params, buf);
 507				value = n;
 508			}
 509			/* else stalls ... spec says to avoid that */
 510		}
 511		break;
 512
 513	default:
 514invalid:
 515		VDBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 516			ctrl->bRequestType, ctrl->bRequest,
 517			w_value, w_index, w_length);
 518	}
 519
 520	/* respond with data transfer or status phase? */
 521	if (value >= 0) {
 522		DBG(cdev, "rndis req%02x.%02x v%04x i%04x l%d\n",
 523			ctrl->bRequestType, ctrl->bRequest,
 524			w_value, w_index, w_length);
 525		req->zero = (value < w_length);
 526		req->length = value;
 527		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 528		if (value < 0)
 529			ERROR(cdev, "rndis response on err %d\n", value);
 530	}
 531
 532	/* device either stalls (value < 0) or reports success */
 533	return value;
 534}
 535
 536
 537static int rndis_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 538{
 539	struct f_rndis		*rndis = func_to_rndis(f);
 540	struct usb_composite_dev *cdev = f->config->cdev;
 541
 542	/* we know alt == 0 */
 543
 544	if (intf == rndis->ctrl_id) {
 545		VDBG(cdev, "reset rndis control %d\n", intf);
 546		usb_ep_disable(rndis->notify);
 547
 548		if (!rndis->notify->desc) {
 549			VDBG(cdev, "init rndis ctrl %d\n", intf);
 550			if (config_ep_by_speed(cdev->gadget, f, rndis->notify))
 551				goto fail;
 552		}
 553		usb_ep_enable(rndis->notify);
 554
 555	} else if (intf == rndis->data_id) {
 556		struct net_device	*net;
 557
 558		if (rndis->port.in_ep->enabled) {
 559			DBG(cdev, "reset rndis\n");
 560			gether_disconnect(&rndis->port);
 561		}
 562
 563		if (!rndis->port.in_ep->desc || !rndis->port.out_ep->desc) {
 564			DBG(cdev, "init rndis\n");
 565			if (config_ep_by_speed(cdev->gadget, f,
 566					       rndis->port.in_ep) ||
 567			    config_ep_by_speed(cdev->gadget, f,
 568					       rndis->port.out_ep)) {
 569				rndis->port.in_ep->desc = NULL;
 570				rndis->port.out_ep->desc = NULL;
 571				goto fail;
 572			}
 573		}
 574
 575		/* Avoid ZLPs; they can be troublesome. */
 576		rndis->port.is_zlp_ok = false;
 577
 578		/* RNDIS should be in the "RNDIS uninitialized" state,
 579		 * either never activated or after rndis_uninit().
 580		 *
 581		 * We don't want data to flow here until a nonzero packet
 582		 * filter is set, at which point it enters "RNDIS data
 583		 * initialized" state ... but we do want the endpoints
 584		 * to be activated.  It's a strange little state.
 585		 *
 586		 * REVISIT the RNDIS gadget code has done this wrong for a
 587		 * very long time.  We need another call to the link layer
 588		 * code -- gether_updown(...bool) maybe -- to do it right.
 589		 */
 590		rndis->port.cdc_filter = 0;
 591
 592		DBG(cdev, "RNDIS RX/TX early activation ... \n");
 593		net = gether_connect(&rndis->port);
 594		if (IS_ERR(net))
 595			return PTR_ERR(net);
 596
 597		rndis_set_param_dev(rndis->params, net,
 598				&rndis->port.cdc_filter);
 599	} else
 600		goto fail;
 601
 602	return 0;
 603fail:
 604	return -EINVAL;
 605}
 606
 607static void rndis_disable(struct usb_function *f)
 608{
 609	struct f_rndis		*rndis = func_to_rndis(f);
 610	struct usb_composite_dev *cdev = f->config->cdev;
 611
 612	if (!rndis->notify->enabled)
 613		return;
 614
 615	DBG(cdev, "rndis deactivated\n");
 616
 617	rndis_uninit(rndis->params);
 618	gether_disconnect(&rndis->port);
 619
 620	usb_ep_disable(rndis->notify);
 621	rndis->notify->desc = NULL;
 622}
 623
 624/*-------------------------------------------------------------------------*/
 625
 626/*
 627 * This isn't quite the same mechanism as CDC Ethernet, since the
 628 * notification scheme passes less data, but the same set of link
 629 * states must be tested.  A key difference is that altsettings are
 630 * not used to tell whether the link should send packets or not.
 631 */
 632
 633static void rndis_open(struct gether *geth)
 634{
 635	struct f_rndis		*rndis = func_to_rndis(&geth->func);
 636	struct usb_composite_dev *cdev = geth->func.config->cdev;
 637
 638	DBG(cdev, "%s\n", __func__);
 639
 640	rndis_set_param_medium(rndis->params, RNDIS_MEDIUM_802_3,
 641				bitrate(cdev->gadget) / 100);
 642	rndis_signal_connect(rndis->params);
 643}
 644
 645static void rndis_close(struct gether *geth)
 646{
 647	struct f_rndis		*rndis = func_to_rndis(&geth->func);
 648
 649	DBG(geth->func.config->cdev, "%s\n", __func__);
 650
 651	rndis_set_param_medium(rndis->params, RNDIS_MEDIUM_802_3, 0);
 652	rndis_signal_disconnect(rndis->params);
 653}
 654
 655/*-------------------------------------------------------------------------*/
 656
 657/* Some controllers can't support RNDIS ... */
 658static inline bool can_support_rndis(struct usb_configuration *c)
 659{
 660	/* everything else is *presumably* fine */
 661	return true;
 662}
 663
 664/* ethernet function driver setup/binding */
 665
 666static int
 667rndis_bind(struct usb_configuration *c, struct usb_function *f)
 668{
 669	struct usb_composite_dev *cdev = c->cdev;
 670	struct f_rndis		*rndis = func_to_rndis(f);
 671	struct usb_string	*us;
 672	int			status;
 673	struct usb_ep		*ep;
 674
 675	struct f_rndis_opts *rndis_opts;
 676
 677	if (!can_support_rndis(c))
 678		return -EINVAL;
 679
 680	rndis_opts = container_of(f->fi, struct f_rndis_opts, func_inst);
 681
 682	if (cdev->use_os_string) {
 683		f->os_desc_table = kzalloc(sizeof(*f->os_desc_table),
 684					   GFP_KERNEL);
 685		if (!f->os_desc_table)
 686			return -ENOMEM;
 687		f->os_desc_n = 1;
 688		f->os_desc_table[0].os_desc = &rndis_opts->rndis_os_desc;
 689	}
 690
 691	rndis_iad_descriptor.bFunctionClass = rndis_opts->class;
 692	rndis_iad_descriptor.bFunctionSubClass = rndis_opts->subclass;
 693	rndis_iad_descriptor.bFunctionProtocol = rndis_opts->protocol;
 694
 695	/*
 696	 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
 697	 * configurations are bound in sequence with list_for_each_entry,
 698	 * in each configuration its functions are bound in sequence
 699	 * with list_for_each_entry, so we assume no race condition
 700	 * with regard to rndis_opts->bound access
 701	 */
 702	if (!rndis_opts->bound) {
 703		gether_set_gadget(rndis_opts->net, cdev->gadget);
 704		status = gether_register_netdev(rndis_opts->net);
 705		if (status)
 706			goto fail;
 707		rndis_opts->bound = true;
 708	}
 709
 710	us = usb_gstrings_attach(cdev, rndis_strings,
 711				 ARRAY_SIZE(rndis_string_defs));
 712	if (IS_ERR(us)) {
 713		status = PTR_ERR(us);
 714		goto fail;
 715	}
 716	rndis_control_intf.iInterface = us[0].id;
 717	rndis_data_intf.iInterface = us[1].id;
 718	rndis_iad_descriptor.iFunction = us[2].id;
 719
 720	/* allocate instance-specific interface IDs */
 721	status = usb_interface_id(c, f);
 722	if (status < 0)
 723		goto fail;
 724	rndis->ctrl_id = status;
 725	rndis_iad_descriptor.bFirstInterface = status;
 726
 727	rndis_control_intf.bInterfaceNumber = status;
 728	rndis_union_desc.bMasterInterface0 = status;
 729
 730	if (cdev->use_os_string)
 731		f->os_desc_table[0].if_id =
 732			rndis_iad_descriptor.bFirstInterface;
 733
 734	status = usb_interface_id(c, f);
 735	if (status < 0)
 736		goto fail;
 737	rndis->data_id = status;
 738
 739	rndis_data_intf.bInterfaceNumber = status;
 740	rndis_union_desc.bSlaveInterface0 = status;
 741
 742	status = -ENODEV;
 743
 744	/* allocate instance-specific endpoints */
 745	ep = usb_ep_autoconfig(cdev->gadget, &fs_in_desc);
 746	if (!ep)
 747		goto fail;
 748	rndis->port.in_ep = ep;
 749
 750	ep = usb_ep_autoconfig(cdev->gadget, &fs_out_desc);
 751	if (!ep)
 752		goto fail;
 753	rndis->port.out_ep = ep;
 754
 755	/* NOTE:  a status/notification endpoint is, strictly speaking,
 756	 * optional.  We don't treat it that way though!  It's simpler,
 757	 * and some newer profiles don't treat it as optional.
 758	 */
 759	ep = usb_ep_autoconfig(cdev->gadget, &fs_notify_desc);
 760	if (!ep)
 761		goto fail;
 762	rndis->notify = ep;
 763
 764	status = -ENOMEM;
 765
 766	/* allocate notification request and buffer */
 767	rndis->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
 768	if (!rndis->notify_req)
 769		goto fail;
 770	rndis->notify_req->buf = kmalloc(STATUS_BYTECOUNT, GFP_KERNEL);
 771	if (!rndis->notify_req->buf)
 772		goto fail;
 773	rndis->notify_req->length = STATUS_BYTECOUNT;
 774	rndis->notify_req->context = rndis;
 775	rndis->notify_req->complete = rndis_response_complete;
 776
 777	/* support all relevant hardware speeds... we expect that when
 778	 * hardware is dual speed, all bulk-capable endpoints work at
 779	 * both speeds
 780	 */
 781	hs_in_desc.bEndpointAddress = fs_in_desc.bEndpointAddress;
 782	hs_out_desc.bEndpointAddress = fs_out_desc.bEndpointAddress;
 783	hs_notify_desc.bEndpointAddress = fs_notify_desc.bEndpointAddress;
 784
 785	ss_in_desc.bEndpointAddress = fs_in_desc.bEndpointAddress;
 786	ss_out_desc.bEndpointAddress = fs_out_desc.bEndpointAddress;
 787	ss_notify_desc.bEndpointAddress = fs_notify_desc.bEndpointAddress;
 788
 789	status = usb_assign_descriptors(f, eth_fs_function, eth_hs_function,
 790			eth_ss_function, NULL);
 791	if (status)
 792		goto fail;
 793
 794	rndis->port.open = rndis_open;
 795	rndis->port.close = rndis_close;
 796
 797	rndis_set_param_medium(rndis->params, RNDIS_MEDIUM_802_3, 0);
 798	rndis_set_host_mac(rndis->params, rndis->ethaddr);
 799
 800	if (rndis->manufacturer && rndis->vendorID &&
 801			rndis_set_param_vendor(rndis->params, rndis->vendorID,
 802					       rndis->manufacturer)) {
 803		status = -EINVAL;
 804		goto fail_free_descs;
 805	}
 806
 807	/* NOTE:  all that is done without knowing or caring about
 808	 * the network link ... which is unavailable to this code
 809	 * until we're activated via set_alt().
 810	 */
 811
 812	DBG(cdev, "RNDIS: %s speed IN/%s OUT/%s NOTIFY/%s\n",
 813			gadget_is_superspeed(c->cdev->gadget) ? "super" :
 814			gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
 815			rndis->port.in_ep->name, rndis->port.out_ep->name,
 816			rndis->notify->name);
 817	return 0;
 818
 819fail_free_descs:
 820	usb_free_all_descriptors(f);
 821fail:
 822	kfree(f->os_desc_table);
 823	f->os_desc_n = 0;
 824
 825	if (rndis->notify_req) {
 826		kfree(rndis->notify_req->buf);
 827		usb_ep_free_request(rndis->notify, rndis->notify_req);
 828	}
 829
 830	ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
 831
 832	return status;
 833}
 834
 835void rndis_borrow_net(struct usb_function_instance *f, struct net_device *net)
 836{
 837	struct f_rndis_opts *opts;
 838
 839	opts = container_of(f, struct f_rndis_opts, func_inst);
 840	if (opts->bound)
 841		gether_cleanup(netdev_priv(opts->net));
 842	else
 843		free_netdev(opts->net);
 844	opts->borrowed_net = opts->bound = true;
 845	opts->net = net;
 846}
 847EXPORT_SYMBOL_GPL(rndis_borrow_net);
 848
 849static inline struct f_rndis_opts *to_f_rndis_opts(struct config_item *item)
 850{
 851	return container_of(to_config_group(item), struct f_rndis_opts,
 852			    func_inst.group);
 853}
 854
 855/* f_rndis_item_ops */
 856USB_ETHERNET_CONFIGFS_ITEM(rndis);
 857
 858/* f_rndis_opts_dev_addr */
 859USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(rndis);
 860
 861/* f_rndis_opts_host_addr */
 862USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(rndis);
 863
 864/* f_rndis_opts_qmult */
 865USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(rndis);
 866
 867/* f_rndis_opts_ifname */
 868USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(rndis);
 869
 870/* f_rndis_opts_class */
 871USB_ETHER_CONFIGFS_ITEM_ATTR_U8_RW(rndis, class);
 872
 873/* f_rndis_opts_subclass */
 874USB_ETHER_CONFIGFS_ITEM_ATTR_U8_RW(rndis, subclass);
 875
 876/* f_rndis_opts_protocol */
 877USB_ETHER_CONFIGFS_ITEM_ATTR_U8_RW(rndis, protocol);
 878
 879static struct configfs_attribute *rndis_attrs[] = {
 880	&rndis_opts_attr_dev_addr,
 881	&rndis_opts_attr_host_addr,
 882	&rndis_opts_attr_qmult,
 883	&rndis_opts_attr_ifname,
 884	&rndis_opts_attr_class,
 885	&rndis_opts_attr_subclass,
 886	&rndis_opts_attr_protocol,
 887	NULL,
 888};
 889
 890static const struct config_item_type rndis_func_type = {
 891	.ct_item_ops	= &rndis_item_ops,
 892	.ct_attrs	= rndis_attrs,
 893	.ct_owner	= THIS_MODULE,
 894};
 895
 896static void rndis_free_inst(struct usb_function_instance *f)
 897{
 898	struct f_rndis_opts *opts;
 899
 900	opts = container_of(f, struct f_rndis_opts, func_inst);
 901	if (!opts->borrowed_net) {
 902		if (opts->bound)
 903			gether_cleanup(netdev_priv(opts->net));
 904		else
 905			free_netdev(opts->net);
 906	}
 907
 908	kfree(opts->rndis_interf_group);	/* single VLA chunk */
 909	kfree(opts);
 910}
 911
 912static struct usb_function_instance *rndis_alloc_inst(void)
 913{
 914	struct f_rndis_opts *opts;
 915	struct usb_os_desc *descs[1];
 916	char *names[1];
 917	struct config_group *rndis_interf_group;
 918
 919	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
 920	if (!opts)
 921		return ERR_PTR(-ENOMEM);
 922	opts->rndis_os_desc.ext_compat_id = opts->rndis_ext_compat_id;
 923
 924	mutex_init(&opts->lock);
 925	opts->func_inst.free_func_inst = rndis_free_inst;
 926	opts->net = gether_setup_default();
 927	if (IS_ERR(opts->net)) {
 928		struct net_device *net = opts->net;
 929		kfree(opts);
 930		return ERR_CAST(net);
 931	}
 932	INIT_LIST_HEAD(&opts->rndis_os_desc.ext_prop);
 933
 934	opts->class = rndis_iad_descriptor.bFunctionClass;
 935	opts->subclass = rndis_iad_descriptor.bFunctionSubClass;
 936	opts->protocol = rndis_iad_descriptor.bFunctionProtocol;
 937
 938	descs[0] = &opts->rndis_os_desc;
 939	names[0] = "rndis";
 940	config_group_init_type_name(&opts->func_inst.group, "",
 941				    &rndis_func_type);
 942	rndis_interf_group =
 943		usb_os_desc_prepare_interf_dir(&opts->func_inst.group, 1, descs,
 944					       names, THIS_MODULE);
 945	if (IS_ERR(rndis_interf_group)) {
 946		rndis_free_inst(&opts->func_inst);
 947		return ERR_CAST(rndis_interf_group);
 948	}
 949	opts->rndis_interf_group = rndis_interf_group;
 950
 951	return &opts->func_inst;
 952}
 953
 954static void rndis_free(struct usb_function *f)
 955{
 956	struct f_rndis *rndis;
 957	struct f_rndis_opts *opts;
 958
 959	rndis = func_to_rndis(f);
 960	rndis_deregister(rndis->params);
 961	opts = container_of(f->fi, struct f_rndis_opts, func_inst);
 962	kfree(rndis);
 963	mutex_lock(&opts->lock);
 964	opts->refcnt--;
 965	mutex_unlock(&opts->lock);
 966}
 967
 968static void rndis_unbind(struct usb_configuration *c, struct usb_function *f)
 969{
 970	struct f_rndis		*rndis = func_to_rndis(f);
 971
 972	kfree(f->os_desc_table);
 973	f->os_desc_n = 0;
 974	usb_free_all_descriptors(f);
 975
 976	kfree(rndis->notify_req->buf);
 977	usb_ep_free_request(rndis->notify, rndis->notify_req);
 978}
 979
 980static struct usb_function *rndis_alloc(struct usb_function_instance *fi)
 981{
 982	struct f_rndis	*rndis;
 983	struct f_rndis_opts *opts;
 984	struct rndis_params *params;
 985
 986	/* allocate and initialize one new instance */
 987	rndis = kzalloc(sizeof(*rndis), GFP_KERNEL);
 988	if (!rndis)
 989		return ERR_PTR(-ENOMEM);
 990
 991	opts = container_of(fi, struct f_rndis_opts, func_inst);
 992	mutex_lock(&opts->lock);
 993	opts->refcnt++;
 994
 995	gether_get_host_addr_u8(opts->net, rndis->ethaddr);
 996	rndis->vendorID = opts->vendor_id;
 997	rndis->manufacturer = opts->manufacturer;
 998
 999	rndis->port.ioport = netdev_priv(opts->net);
1000	mutex_unlock(&opts->lock);
1001	/* RNDIS activates when the host changes this filter */
1002	rndis->port.cdc_filter = 0;
1003
1004	/* RNDIS has special (and complex) framing */
1005	rndis->port.header_len = sizeof(struct rndis_packet_msg_type);
1006	rndis->port.wrap = rndis_add_header;
1007	rndis->port.unwrap = rndis_rm_hdr;
1008
1009	rndis->port.func.name = "rndis";
1010	/* descriptors are per-instance copies */
1011	rndis->port.func.bind = rndis_bind;
1012	rndis->port.func.unbind = rndis_unbind;
1013	rndis->port.func.set_alt = rndis_set_alt;
1014	rndis->port.func.setup = rndis_setup;
1015	rndis->port.func.disable = rndis_disable;
1016	rndis->port.func.free_func = rndis_free;
1017
1018	params = rndis_register(rndis_response_available, rndis);
1019	if (IS_ERR(params)) {
1020		kfree(rndis);
1021		return ERR_CAST(params);
1022	}
1023	rndis->params = params;
1024
1025	return &rndis->port.func;
1026}
1027
1028DECLARE_USB_FUNCTION_INIT(rndis, rndis_alloc_inst, rndis_alloc);
1029MODULE_LICENSE("GPL");
1030MODULE_AUTHOR("David Brownell");