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   1/*
   2 * f_ncm.c -- USB CDC Network (NCM) link function driver
   3 *
   4 * Copyright (C) 2010 Nokia Corporation
   5 * Contact: Yauheni Kaliuta <yauheni.kaliuta@nokia.com>
   6 *
   7 * The driver borrows from f_ecm.c which is:
   8 *
   9 * Copyright (C) 2003-2005,2008 David Brownell
  10 * Copyright (C) 2008 Nokia Corporation
  11 *
  12 * This program is free software; you can redistribute it and/or modify
  13 * it under the terms of the GNU General Public License as published by
  14 * the Free Software Foundation; either version 2 of the License, or
  15 * (at your option) any later version.
  16 */
  17
  18#include <linux/kernel.h>
  19#include <linux/module.h>
  20#include <linux/device.h>
  21#include <linux/etherdevice.h>
  22#include <linux/crc32.h>
  23
  24#include <linux/usb/cdc.h>
  25
  26#include "u_ether.h"
  27#include "u_ether_configfs.h"
  28#include "u_ncm.h"
  29
  30/*
  31 * This function is a "CDC Network Control Model" (CDC NCM) Ethernet link.
  32 * NCM is intended to be used with high-speed network attachments.
  33 *
  34 * Note that NCM requires the use of "alternate settings" for its data
  35 * interface.  This means that the set_alt() method has real work to do,
  36 * and also means that a get_alt() method is required.
  37 */
  38
  39/* to trigger crc/non-crc ndp signature */
  40
  41#define NCM_NDP_HDR_CRC_MASK	0x01000000
  42#define NCM_NDP_HDR_CRC		0x01000000
  43#define NCM_NDP_HDR_NOCRC	0x00000000
  44
  45enum ncm_notify_state {
  46	NCM_NOTIFY_NONE,		/* don't notify */
  47	NCM_NOTIFY_CONNECT,		/* issue CONNECT next */
  48	NCM_NOTIFY_SPEED,		/* issue SPEED_CHANGE next */
  49};
  50
  51struct f_ncm {
  52	struct gether			port;
  53	u8				ctrl_id, data_id;
  54
  55	char				ethaddr[14];
  56
  57	struct usb_ep			*notify;
  58	struct usb_request		*notify_req;
  59	u8				notify_state;
  60	bool				is_open;
  61
  62	const struct ndp_parser_opts	*parser_opts;
  63	bool				is_crc;
  64	u32				ndp_sign;
  65
  66	/*
  67	 * for notification, it is accessed from both
  68	 * callback and ethernet open/close
  69	 */
  70	spinlock_t			lock;
  71
  72	struct net_device		*netdev;
  73
  74	/* For multi-frame NDP TX */
  75	struct sk_buff			*skb_tx_data;
  76	struct sk_buff			*skb_tx_ndp;
  77	u16				ndp_dgram_count;
  78	bool				timer_force_tx;
  79	struct tasklet_struct		tx_tasklet;
  80	struct hrtimer			task_timer;
  81
  82	bool				timer_stopping;
  83};
  84
  85static inline struct f_ncm *func_to_ncm(struct usb_function *f)
  86{
  87	return container_of(f, struct f_ncm, port.func);
  88}
  89
  90/* peak (theoretical) bulk transfer rate in bits-per-second */
  91static inline unsigned ncm_bitrate(struct usb_gadget *g)
  92{
  93	if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
  94		return 13 * 1024 * 8 * 1000 * 8;
  95	else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
  96		return 13 * 512 * 8 * 1000 * 8;
  97	else
  98		return 19 *  64 * 1 * 1000 * 8;
  99}
 100
 101/*-------------------------------------------------------------------------*/
 102
 103/*
 104 * We cannot group frames so use just the minimal size which ok to put
 105 * one max-size ethernet frame.
 106 * If the host can group frames, allow it to do that, 16K is selected,
 107 * because it's used by default by the current linux host driver
 108 */
 109#define NTB_DEFAULT_IN_SIZE	16384
 110#define NTB_OUT_SIZE		16384
 111
 112/* Allocation for storing the NDP, 32 should suffice for a
 113 * 16k packet. This allows a maximum of 32 * 507 Byte packets to
 114 * be transmitted in a single 16kB skb, though when sending full size
 115 * packets this limit will be plenty.
 116 * Smaller packets are not likely to be trying to maximize the
 117 * throughput and will be mstly sending smaller infrequent frames.
 118 */
 119#define TX_MAX_NUM_DPE		32
 120
 121/* Delay for the transmit to wait before sending an unfilled NTB frame. */
 122#define TX_TIMEOUT_NSECS	300000
 123
 124#define FORMATS_SUPPORTED	(USB_CDC_NCM_NTB16_SUPPORTED |	\
 125				 USB_CDC_NCM_NTB32_SUPPORTED)
 126
 127static struct usb_cdc_ncm_ntb_parameters ntb_parameters = {
 128	.wLength = cpu_to_le16(sizeof(ntb_parameters)),
 129	.bmNtbFormatsSupported = cpu_to_le16(FORMATS_SUPPORTED),
 130	.dwNtbInMaxSize = cpu_to_le32(NTB_DEFAULT_IN_SIZE),
 131	.wNdpInDivisor = cpu_to_le16(4),
 132	.wNdpInPayloadRemainder = cpu_to_le16(0),
 133	.wNdpInAlignment = cpu_to_le16(4),
 134
 135	.dwNtbOutMaxSize = cpu_to_le32(NTB_OUT_SIZE),
 136	.wNdpOutDivisor = cpu_to_le16(4),
 137	.wNdpOutPayloadRemainder = cpu_to_le16(0),
 138	.wNdpOutAlignment = cpu_to_le16(4),
 139};
 140
 141/*
 142 * Use wMaxPacketSize big enough to fit CDC_NOTIFY_SPEED_CHANGE in one
 143 * packet, to simplify cancellation; and a big transfer interval, to
 144 * waste less bandwidth.
 145 */
 146
 147#define NCM_STATUS_INTERVAL_MS		32
 148#define NCM_STATUS_BYTECOUNT		16	/* 8 byte header + data */
 149
 150static struct usb_interface_assoc_descriptor ncm_iad_desc = {
 151	.bLength =		sizeof ncm_iad_desc,
 152	.bDescriptorType =	USB_DT_INTERFACE_ASSOCIATION,
 153
 154	/* .bFirstInterface =	DYNAMIC, */
 155	.bInterfaceCount =	2,	/* control + data */
 156	.bFunctionClass =	USB_CLASS_COMM,
 157	.bFunctionSubClass =	USB_CDC_SUBCLASS_NCM,
 158	.bFunctionProtocol =	USB_CDC_PROTO_NONE,
 159	/* .iFunction =		DYNAMIC */
 160};
 161
 162/* interface descriptor: */
 163
 164static struct usb_interface_descriptor ncm_control_intf = {
 165	.bLength =		sizeof ncm_control_intf,
 166	.bDescriptorType =	USB_DT_INTERFACE,
 167
 168	/* .bInterfaceNumber = DYNAMIC */
 169	.bNumEndpoints =	1,
 170	.bInterfaceClass =	USB_CLASS_COMM,
 171	.bInterfaceSubClass =	USB_CDC_SUBCLASS_NCM,
 172	.bInterfaceProtocol =	USB_CDC_PROTO_NONE,
 173	/* .iInterface = DYNAMIC */
 174};
 175
 176static struct usb_cdc_header_desc ncm_header_desc = {
 177	.bLength =		sizeof ncm_header_desc,
 178	.bDescriptorType =	USB_DT_CS_INTERFACE,
 179	.bDescriptorSubType =	USB_CDC_HEADER_TYPE,
 180
 181	.bcdCDC =		cpu_to_le16(0x0110),
 182};
 183
 184static struct usb_cdc_union_desc ncm_union_desc = {
 185	.bLength =		sizeof(ncm_union_desc),
 186	.bDescriptorType =	USB_DT_CS_INTERFACE,
 187	.bDescriptorSubType =	USB_CDC_UNION_TYPE,
 188	/* .bMasterInterface0 =	DYNAMIC */
 189	/* .bSlaveInterface0 =	DYNAMIC */
 190};
 191
 192static struct usb_cdc_ether_desc ecm_desc = {
 193	.bLength =		sizeof ecm_desc,
 194	.bDescriptorType =	USB_DT_CS_INTERFACE,
 195	.bDescriptorSubType =	USB_CDC_ETHERNET_TYPE,
 196
 197	/* this descriptor actually adds value, surprise! */
 198	/* .iMACAddress = DYNAMIC */
 199	.bmEthernetStatistics =	cpu_to_le32(0), /* no statistics */
 200	.wMaxSegmentSize =	cpu_to_le16(ETH_FRAME_LEN),
 201	.wNumberMCFilters =	cpu_to_le16(0),
 202	.bNumberPowerFilters =	0,
 203};
 204
 205#define NCAPS	(USB_CDC_NCM_NCAP_ETH_FILTER | USB_CDC_NCM_NCAP_CRC_MODE)
 206
 207static struct usb_cdc_ncm_desc ncm_desc = {
 208	.bLength =		sizeof ncm_desc,
 209	.bDescriptorType =	USB_DT_CS_INTERFACE,
 210	.bDescriptorSubType =	USB_CDC_NCM_TYPE,
 211
 212	.bcdNcmVersion =	cpu_to_le16(0x0100),
 213	/* can process SetEthernetPacketFilter */
 214	.bmNetworkCapabilities = NCAPS,
 215};
 216
 217/* the default data interface has no endpoints ... */
 218
 219static struct usb_interface_descriptor ncm_data_nop_intf = {
 220	.bLength =		sizeof ncm_data_nop_intf,
 221	.bDescriptorType =	USB_DT_INTERFACE,
 222
 223	.bInterfaceNumber =	1,
 224	.bAlternateSetting =	0,
 225	.bNumEndpoints =	0,
 226	.bInterfaceClass =	USB_CLASS_CDC_DATA,
 227	.bInterfaceSubClass =	0,
 228	.bInterfaceProtocol =	USB_CDC_NCM_PROTO_NTB,
 229	/* .iInterface = DYNAMIC */
 230};
 231
 232/* ... but the "real" data interface has two bulk endpoints */
 233
 234static struct usb_interface_descriptor ncm_data_intf = {
 235	.bLength =		sizeof ncm_data_intf,
 236	.bDescriptorType =	USB_DT_INTERFACE,
 237
 238	.bInterfaceNumber =	1,
 239	.bAlternateSetting =	1,
 240	.bNumEndpoints =	2,
 241	.bInterfaceClass =	USB_CLASS_CDC_DATA,
 242	.bInterfaceSubClass =	0,
 243	.bInterfaceProtocol =	USB_CDC_NCM_PROTO_NTB,
 244	/* .iInterface = DYNAMIC */
 245};
 246
 247/* full speed support: */
 248
 249static struct usb_endpoint_descriptor fs_ncm_notify_desc = {
 250	.bLength =		USB_DT_ENDPOINT_SIZE,
 251	.bDescriptorType =	USB_DT_ENDPOINT,
 252
 253	.bEndpointAddress =	USB_DIR_IN,
 254	.bmAttributes =		USB_ENDPOINT_XFER_INT,
 255	.wMaxPacketSize =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
 256	.bInterval =		NCM_STATUS_INTERVAL_MS,
 257};
 258
 259static struct usb_endpoint_descriptor fs_ncm_in_desc = {
 260	.bLength =		USB_DT_ENDPOINT_SIZE,
 261	.bDescriptorType =	USB_DT_ENDPOINT,
 262
 263	.bEndpointAddress =	USB_DIR_IN,
 264	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
 265};
 266
 267static struct usb_endpoint_descriptor fs_ncm_out_desc = {
 268	.bLength =		USB_DT_ENDPOINT_SIZE,
 269	.bDescriptorType =	USB_DT_ENDPOINT,
 270
 271	.bEndpointAddress =	USB_DIR_OUT,
 272	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
 273};
 274
 275static struct usb_descriptor_header *ncm_fs_function[] = {
 276	(struct usb_descriptor_header *) &ncm_iad_desc,
 277	/* CDC NCM control descriptors */
 278	(struct usb_descriptor_header *) &ncm_control_intf,
 279	(struct usb_descriptor_header *) &ncm_header_desc,
 280	(struct usb_descriptor_header *) &ncm_union_desc,
 281	(struct usb_descriptor_header *) &ecm_desc,
 282	(struct usb_descriptor_header *) &ncm_desc,
 283	(struct usb_descriptor_header *) &fs_ncm_notify_desc,
 284	/* data interface, altsettings 0 and 1 */
 285	(struct usb_descriptor_header *) &ncm_data_nop_intf,
 286	(struct usb_descriptor_header *) &ncm_data_intf,
 287	(struct usb_descriptor_header *) &fs_ncm_in_desc,
 288	(struct usb_descriptor_header *) &fs_ncm_out_desc,
 289	NULL,
 290};
 291
 292/* high speed support: */
 293
 294static struct usb_endpoint_descriptor hs_ncm_notify_desc = {
 295	.bLength =		USB_DT_ENDPOINT_SIZE,
 296	.bDescriptorType =	USB_DT_ENDPOINT,
 297
 298	.bEndpointAddress =	USB_DIR_IN,
 299	.bmAttributes =		USB_ENDPOINT_XFER_INT,
 300	.wMaxPacketSize =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
 301	.bInterval =		USB_MS_TO_HS_INTERVAL(NCM_STATUS_INTERVAL_MS),
 302};
 303static struct usb_endpoint_descriptor hs_ncm_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(512),
 310};
 311
 312static struct usb_endpoint_descriptor hs_ncm_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(512),
 319};
 320
 321static struct usb_descriptor_header *ncm_hs_function[] = {
 322	(struct usb_descriptor_header *) &ncm_iad_desc,
 323	/* CDC NCM control descriptors */
 324	(struct usb_descriptor_header *) &ncm_control_intf,
 325	(struct usb_descriptor_header *) &ncm_header_desc,
 326	(struct usb_descriptor_header *) &ncm_union_desc,
 327	(struct usb_descriptor_header *) &ecm_desc,
 328	(struct usb_descriptor_header *) &ncm_desc,
 329	(struct usb_descriptor_header *) &hs_ncm_notify_desc,
 330	/* data interface, altsettings 0 and 1 */
 331	(struct usb_descriptor_header *) &ncm_data_nop_intf,
 332	(struct usb_descriptor_header *) &ncm_data_intf,
 333	(struct usb_descriptor_header *) &hs_ncm_in_desc,
 334	(struct usb_descriptor_header *) &hs_ncm_out_desc,
 335	NULL,
 336};
 337
 338
 339/* super speed support: */
 340
 341static struct usb_endpoint_descriptor ss_ncm_notify_desc = {
 342	.bLength =		USB_DT_ENDPOINT_SIZE,
 343	.bDescriptorType =	USB_DT_ENDPOINT,
 344
 345	.bEndpointAddress =	USB_DIR_IN,
 346	.bmAttributes =		USB_ENDPOINT_XFER_INT,
 347	.wMaxPacketSize =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
 348	.bInterval =		USB_MS_TO_HS_INTERVAL(NCM_STATUS_INTERVAL_MS)
 349};
 350
 351static struct usb_ss_ep_comp_descriptor ss_ncm_notify_comp_desc = {
 352	.bLength =		sizeof(ss_ncm_notify_comp_desc),
 353	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
 354
 355	/* the following 3 values can be tweaked if necessary */
 356	/* .bMaxBurst =		0, */
 357	/* .bmAttributes =	0, */
 358	.wBytesPerInterval =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
 359};
 360
 361static struct usb_endpoint_descriptor ss_ncm_in_desc = {
 362	.bLength =		USB_DT_ENDPOINT_SIZE,
 363	.bDescriptorType =	USB_DT_ENDPOINT,
 364
 365	.bEndpointAddress =	USB_DIR_IN,
 366	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
 367	.wMaxPacketSize =	cpu_to_le16(1024),
 368};
 369
 370static struct usb_endpoint_descriptor ss_ncm_out_desc = {
 371	.bLength =		USB_DT_ENDPOINT_SIZE,
 372	.bDescriptorType =	USB_DT_ENDPOINT,
 373
 374	.bEndpointAddress =	USB_DIR_OUT,
 375	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
 376	.wMaxPacketSize =	cpu_to_le16(1024),
 377};
 378
 379static struct usb_ss_ep_comp_descriptor ss_ncm_bulk_comp_desc = {
 380	.bLength =		sizeof(ss_ncm_bulk_comp_desc),
 381	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
 382
 383	/* the following 2 values can be tweaked if necessary */
 384	/* .bMaxBurst =		0, */
 385	/* .bmAttributes =	0, */
 386};
 387
 388static struct usb_descriptor_header *ncm_ss_function[] = {
 389	(struct usb_descriptor_header *) &ncm_iad_desc,
 390	/* CDC NCM control descriptors */
 391	(struct usb_descriptor_header *) &ncm_control_intf,
 392	(struct usb_descriptor_header *) &ncm_header_desc,
 393	(struct usb_descriptor_header *) &ncm_union_desc,
 394	(struct usb_descriptor_header *) &ecm_desc,
 395	(struct usb_descriptor_header *) &ncm_desc,
 396	(struct usb_descriptor_header *) &ss_ncm_notify_desc,
 397	(struct usb_descriptor_header *) &ss_ncm_notify_comp_desc,
 398	/* data interface, altsettings 0 and 1 */
 399	(struct usb_descriptor_header *) &ncm_data_nop_intf,
 400	(struct usb_descriptor_header *) &ncm_data_intf,
 401	(struct usb_descriptor_header *) &ss_ncm_in_desc,
 402	(struct usb_descriptor_header *) &ss_ncm_bulk_comp_desc,
 403	(struct usb_descriptor_header *) &ss_ncm_out_desc,
 404	(struct usb_descriptor_header *) &ss_ncm_bulk_comp_desc,
 405	NULL,
 406};
 407
 408/* string descriptors: */
 409
 410#define STRING_CTRL_IDX	0
 411#define STRING_MAC_IDX	1
 412#define STRING_DATA_IDX	2
 413#define STRING_IAD_IDX	3
 414
 415static struct usb_string ncm_string_defs[] = {
 416	[STRING_CTRL_IDX].s = "CDC Network Control Model (NCM)",
 417	[STRING_MAC_IDX].s = "",
 418	[STRING_DATA_IDX].s = "CDC Network Data",
 419	[STRING_IAD_IDX].s = "CDC NCM",
 420	{  } /* end of list */
 421};
 422
 423static struct usb_gadget_strings ncm_string_table = {
 424	.language =		0x0409,	/* en-us */
 425	.strings =		ncm_string_defs,
 426};
 427
 428static struct usb_gadget_strings *ncm_strings[] = {
 429	&ncm_string_table,
 430	NULL,
 431};
 432
 433/*
 434 * Here are options for NCM Datagram Pointer table (NDP) parser.
 435 * There are 2 different formats: NDP16 and NDP32 in the spec (ch. 3),
 436 * in NDP16 offsets and sizes fields are 1 16bit word wide,
 437 * in NDP32 -- 2 16bit words wide. Also signatures are different.
 438 * To make the parser code the same, put the differences in the structure,
 439 * and switch pointers to the structures when the format is changed.
 440 */
 441
 442struct ndp_parser_opts {
 443	u32		nth_sign;
 444	u32		ndp_sign;
 445	unsigned	nth_size;
 446	unsigned	ndp_size;
 447	unsigned	dpe_size;
 448	unsigned	ndplen_align;
 449	/* sizes in u16 units */
 450	unsigned	dgram_item_len; /* index or length */
 451	unsigned	block_length;
 452	unsigned	ndp_index;
 453	unsigned	reserved1;
 454	unsigned	reserved2;
 455	unsigned	next_ndp_index;
 456};
 457
 458#define INIT_NDP16_OPTS {					\
 459		.nth_sign = USB_CDC_NCM_NTH16_SIGN,		\
 460		.ndp_sign = USB_CDC_NCM_NDP16_NOCRC_SIGN,	\
 461		.nth_size = sizeof(struct usb_cdc_ncm_nth16),	\
 462		.ndp_size = sizeof(struct usb_cdc_ncm_ndp16),	\
 463		.dpe_size = sizeof(struct usb_cdc_ncm_dpe16),	\
 464		.ndplen_align = 4,				\
 465		.dgram_item_len = 1,				\
 466		.block_length = 1,				\
 467		.ndp_index = 1,					\
 468		.reserved1 = 0,					\
 469		.reserved2 = 0,					\
 470		.next_ndp_index = 1,				\
 471	}
 472
 473
 474#define INIT_NDP32_OPTS {					\
 475		.nth_sign = USB_CDC_NCM_NTH32_SIGN,		\
 476		.ndp_sign = USB_CDC_NCM_NDP32_NOCRC_SIGN,	\
 477		.nth_size = sizeof(struct usb_cdc_ncm_nth32),	\
 478		.ndp_size = sizeof(struct usb_cdc_ncm_ndp32),	\
 479		.dpe_size = sizeof(struct usb_cdc_ncm_dpe32),	\
 480		.ndplen_align = 8,				\
 481		.dgram_item_len = 2,				\
 482		.block_length = 2,				\
 483		.ndp_index = 2,					\
 484		.reserved1 = 1,					\
 485		.reserved2 = 2,					\
 486		.next_ndp_index = 2,				\
 487	}
 488
 489static const struct ndp_parser_opts ndp16_opts = INIT_NDP16_OPTS;
 490static const struct ndp_parser_opts ndp32_opts = INIT_NDP32_OPTS;
 491
 492static inline void put_ncm(__le16 **p, unsigned size, unsigned val)
 493{
 494	switch (size) {
 495	case 1:
 496		put_unaligned_le16((u16)val, *p);
 497		break;
 498	case 2:
 499		put_unaligned_le32((u32)val, *p);
 500
 501		break;
 502	default:
 503		BUG();
 504	}
 505
 506	*p += size;
 507}
 508
 509static inline unsigned get_ncm(__le16 **p, unsigned size)
 510{
 511	unsigned tmp;
 512
 513	switch (size) {
 514	case 1:
 515		tmp = get_unaligned_le16(*p);
 516		break;
 517	case 2:
 518		tmp = get_unaligned_le32(*p);
 519		break;
 520	default:
 521		BUG();
 522	}
 523
 524	*p += size;
 525	return tmp;
 526}
 527
 528/*-------------------------------------------------------------------------*/
 529
 530static inline void ncm_reset_values(struct f_ncm *ncm)
 531{
 532	ncm->parser_opts = &ndp16_opts;
 533	ncm->is_crc = false;
 534	ncm->port.cdc_filter = DEFAULT_FILTER;
 535
 536	/* doesn't make sense for ncm, fixed size used */
 537	ncm->port.header_len = 0;
 538
 539	ncm->port.fixed_out_len = le32_to_cpu(ntb_parameters.dwNtbOutMaxSize);
 540	ncm->port.fixed_in_len = NTB_DEFAULT_IN_SIZE;
 541}
 542
 543/*
 544 * Context: ncm->lock held
 545 */
 546static void ncm_do_notify(struct f_ncm *ncm)
 547{
 548	struct usb_request		*req = ncm->notify_req;
 549	struct usb_cdc_notification	*event;
 550	struct usb_composite_dev	*cdev = ncm->port.func.config->cdev;
 551	__le32				*data;
 552	int				status;
 553
 554	/* notification already in flight? */
 555	if (!req)
 556		return;
 557
 558	event = req->buf;
 559	switch (ncm->notify_state) {
 560	case NCM_NOTIFY_NONE:
 561		return;
 562
 563	case NCM_NOTIFY_CONNECT:
 564		event->bNotificationType = USB_CDC_NOTIFY_NETWORK_CONNECTION;
 565		if (ncm->is_open)
 566			event->wValue = cpu_to_le16(1);
 567		else
 568			event->wValue = cpu_to_le16(0);
 569		event->wLength = 0;
 570		req->length = sizeof *event;
 571
 572		DBG(cdev, "notify connect %s\n",
 573				ncm->is_open ? "true" : "false");
 574		ncm->notify_state = NCM_NOTIFY_NONE;
 575		break;
 576
 577	case NCM_NOTIFY_SPEED:
 578		event->bNotificationType = USB_CDC_NOTIFY_SPEED_CHANGE;
 579		event->wValue = cpu_to_le16(0);
 580		event->wLength = cpu_to_le16(8);
 581		req->length = NCM_STATUS_BYTECOUNT;
 582
 583		/* SPEED_CHANGE data is up/down speeds in bits/sec */
 584		data = req->buf + sizeof *event;
 585		data[0] = cpu_to_le32(ncm_bitrate(cdev->gadget));
 586		data[1] = data[0];
 587
 588		DBG(cdev, "notify speed %d\n", ncm_bitrate(cdev->gadget));
 589		ncm->notify_state = NCM_NOTIFY_CONNECT;
 590		break;
 591	}
 592	event->bmRequestType = 0xA1;
 593	event->wIndex = cpu_to_le16(ncm->ctrl_id);
 594
 595	ncm->notify_req = NULL;
 596	/*
 597	 * In double buffering if there is a space in FIFO,
 598	 * completion callback can be called right after the call,
 599	 * so unlocking
 600	 */
 601	spin_unlock(&ncm->lock);
 602	status = usb_ep_queue(ncm->notify, req, GFP_ATOMIC);
 603	spin_lock(&ncm->lock);
 604	if (status < 0) {
 605		ncm->notify_req = req;
 606		DBG(cdev, "notify --> %d\n", status);
 607	}
 608}
 609
 610/*
 611 * Context: ncm->lock held
 612 */
 613static void ncm_notify(struct f_ncm *ncm)
 614{
 615	/*
 616	 * NOTE on most versions of Linux, host side cdc-ethernet
 617	 * won't listen for notifications until its netdevice opens.
 618	 * The first notification then sits in the FIFO for a long
 619	 * time, and the second one is queued.
 620	 *
 621	 * If ncm_notify() is called before the second (CONNECT)
 622	 * notification is sent, then it will reset to send the SPEED
 623	 * notificaion again (and again, and again), but it's not a problem
 624	 */
 625	ncm->notify_state = NCM_NOTIFY_SPEED;
 626	ncm_do_notify(ncm);
 627}
 628
 629static void ncm_notify_complete(struct usb_ep *ep, struct usb_request *req)
 630{
 631	struct f_ncm			*ncm = req->context;
 632	struct usb_composite_dev	*cdev = ncm->port.func.config->cdev;
 633	struct usb_cdc_notification	*event = req->buf;
 634
 635	spin_lock(&ncm->lock);
 636	switch (req->status) {
 637	case 0:
 638		VDBG(cdev, "Notification %02x sent\n",
 639		     event->bNotificationType);
 640		break;
 641	case -ECONNRESET:
 642	case -ESHUTDOWN:
 643		ncm->notify_state = NCM_NOTIFY_NONE;
 644		break;
 645	default:
 646		DBG(cdev, "event %02x --> %d\n",
 647			event->bNotificationType, req->status);
 648		break;
 649	}
 650	ncm->notify_req = req;
 651	ncm_do_notify(ncm);
 652	spin_unlock(&ncm->lock);
 653}
 654
 655static void ncm_ep0out_complete(struct usb_ep *ep, struct usb_request *req)
 656{
 657	/* now for SET_NTB_INPUT_SIZE only */
 658	unsigned		in_size;
 659	struct usb_function	*f = req->context;
 660	struct f_ncm		*ncm = func_to_ncm(f);
 661	struct usb_composite_dev *cdev = f->config->cdev;
 662
 663	req->context = NULL;
 664	if (req->status || req->actual != req->length) {
 665		DBG(cdev, "Bad control-OUT transfer\n");
 666		goto invalid;
 667	}
 668
 669	in_size = get_unaligned_le32(req->buf);
 670	if (in_size < USB_CDC_NCM_NTB_MIN_IN_SIZE ||
 671	    in_size > le32_to_cpu(ntb_parameters.dwNtbInMaxSize)) {
 672		DBG(cdev, "Got wrong INPUT SIZE (%d) from host\n", in_size);
 673		goto invalid;
 674	}
 675
 676	ncm->port.fixed_in_len = in_size;
 677	VDBG(cdev, "Set NTB INPUT SIZE %d\n", in_size);
 678	return;
 679
 680invalid:
 681	usb_ep_set_halt(ep);
 682	return;
 683}
 684
 685static int ncm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
 686{
 687	struct f_ncm		*ncm = func_to_ncm(f);
 688	struct usb_composite_dev *cdev = f->config->cdev;
 689	struct usb_request	*req = cdev->req;
 690	int			value = -EOPNOTSUPP;
 691	u16			w_index = le16_to_cpu(ctrl->wIndex);
 692	u16			w_value = le16_to_cpu(ctrl->wValue);
 693	u16			w_length = le16_to_cpu(ctrl->wLength);
 694
 695	/*
 696	 * composite driver infrastructure handles everything except
 697	 * CDC class messages; interface activation uses set_alt().
 698	 */
 699	switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
 700	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 701			| USB_CDC_SET_ETHERNET_PACKET_FILTER:
 702		/*
 703		 * see 6.2.30: no data, wIndex = interface,
 704		 * wValue = packet filter bitmap
 705		 */
 706		if (w_length != 0 || w_index != ncm->ctrl_id)
 707			goto invalid;
 708		DBG(cdev, "packet filter %02x\n", w_value);
 709		/*
 710		 * REVISIT locking of cdc_filter.  This assumes the UDC
 711		 * driver won't have a concurrent packet TX irq running on
 712		 * another CPU; or that if it does, this write is atomic...
 713		 */
 714		ncm->port.cdc_filter = w_value;
 715		value = 0;
 716		break;
 717	/*
 718	 * and optionally:
 719	 * case USB_CDC_SEND_ENCAPSULATED_COMMAND:
 720	 * case USB_CDC_GET_ENCAPSULATED_RESPONSE:
 721	 * case USB_CDC_SET_ETHERNET_MULTICAST_FILTERS:
 722	 * case USB_CDC_SET_ETHERNET_PM_PATTERN_FILTER:
 723	 * case USB_CDC_GET_ETHERNET_PM_PATTERN_FILTER:
 724	 * case USB_CDC_GET_ETHERNET_STATISTIC:
 725	 */
 726
 727	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 728		| USB_CDC_GET_NTB_PARAMETERS:
 729
 730		if (w_length == 0 || w_value != 0 || w_index != ncm->ctrl_id)
 731			goto invalid;
 732		value = w_length > sizeof ntb_parameters ?
 733			sizeof ntb_parameters : w_length;
 734		memcpy(req->buf, &ntb_parameters, value);
 735		VDBG(cdev, "Host asked NTB parameters\n");
 736		break;
 737
 738	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 739		| USB_CDC_GET_NTB_INPUT_SIZE:
 740
 741		if (w_length < 4 || w_value != 0 || w_index != ncm->ctrl_id)
 742			goto invalid;
 743		put_unaligned_le32(ncm->port.fixed_in_len, req->buf);
 744		value = 4;
 745		VDBG(cdev, "Host asked INPUT SIZE, sending %d\n",
 746		     ncm->port.fixed_in_len);
 747		break;
 748
 749	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 750		| USB_CDC_SET_NTB_INPUT_SIZE:
 751	{
 752		if (w_length != 4 || w_value != 0 || w_index != ncm->ctrl_id)
 753			goto invalid;
 754		req->complete = ncm_ep0out_complete;
 755		req->length = w_length;
 756		req->context = f;
 757
 758		value = req->length;
 759		break;
 760	}
 761
 762	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 763		| USB_CDC_GET_NTB_FORMAT:
 764	{
 765		uint16_t format;
 766
 767		if (w_length < 2 || w_value != 0 || w_index != ncm->ctrl_id)
 768			goto invalid;
 769		format = (ncm->parser_opts == &ndp16_opts) ? 0x0000 : 0x0001;
 770		put_unaligned_le16(format, req->buf);
 771		value = 2;
 772		VDBG(cdev, "Host asked NTB FORMAT, sending %d\n", format);
 773		break;
 774	}
 775
 776	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 777		| USB_CDC_SET_NTB_FORMAT:
 778	{
 779		if (w_length != 0 || w_index != ncm->ctrl_id)
 780			goto invalid;
 781		switch (w_value) {
 782		case 0x0000:
 783			ncm->parser_opts = &ndp16_opts;
 784			DBG(cdev, "NCM16 selected\n");
 785			break;
 786		case 0x0001:
 787			ncm->parser_opts = &ndp32_opts;
 788			DBG(cdev, "NCM32 selected\n");
 789			break;
 790		default:
 791			goto invalid;
 792		}
 793		value = 0;
 794		break;
 795	}
 796	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 797		| USB_CDC_GET_CRC_MODE:
 798	{
 799		uint16_t is_crc;
 800
 801		if (w_length < 2 || w_value != 0 || w_index != ncm->ctrl_id)
 802			goto invalid;
 803		is_crc = ncm->is_crc ? 0x0001 : 0x0000;
 804		put_unaligned_le16(is_crc, req->buf);
 805		value = 2;
 806		VDBG(cdev, "Host asked CRC MODE, sending %d\n", is_crc);
 807		break;
 808	}
 809
 810	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
 811		| USB_CDC_SET_CRC_MODE:
 812	{
 813		int ndp_hdr_crc = 0;
 814
 815		if (w_length != 0 || w_index != ncm->ctrl_id)
 816			goto invalid;
 817		switch (w_value) {
 818		case 0x0000:
 819			ncm->is_crc = false;
 820			ndp_hdr_crc = NCM_NDP_HDR_NOCRC;
 821			DBG(cdev, "non-CRC mode selected\n");
 822			break;
 823		case 0x0001:
 824			ncm->is_crc = true;
 825			ndp_hdr_crc = NCM_NDP_HDR_CRC;
 826			DBG(cdev, "CRC mode selected\n");
 827			break;
 828		default:
 829			goto invalid;
 830		}
 831		ncm->ndp_sign = ncm->parser_opts->ndp_sign | ndp_hdr_crc;
 832		value = 0;
 833		break;
 834	}
 835
 836	/* and disabled in ncm descriptor: */
 837	/* case USB_CDC_GET_NET_ADDRESS: */
 838	/* case USB_CDC_SET_NET_ADDRESS: */
 839	/* case USB_CDC_GET_MAX_DATAGRAM_SIZE: */
 840	/* case USB_CDC_SET_MAX_DATAGRAM_SIZE: */
 841
 842	default:
 843invalid:
 844		DBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
 845			ctrl->bRequestType, ctrl->bRequest,
 846			w_value, w_index, w_length);
 847	}
 848
 849	/* respond with data transfer or status phase? */
 850	if (value >= 0) {
 851		DBG(cdev, "ncm req%02x.%02x v%04x i%04x l%d\n",
 852			ctrl->bRequestType, ctrl->bRequest,
 853			w_value, w_index, w_length);
 854		req->zero = 0;
 855		req->length = value;
 856		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
 857		if (value < 0)
 858			ERROR(cdev, "ncm req %02x.%02x response err %d\n",
 859					ctrl->bRequestType, ctrl->bRequest,
 860					value);
 861	}
 862
 863	/* device either stalls (value < 0) or reports success */
 864	return value;
 865}
 866
 867
 868static int ncm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 869{
 870	struct f_ncm		*ncm = func_to_ncm(f);
 871	struct usb_composite_dev *cdev = f->config->cdev;
 872
 873	/* Control interface has only altsetting 0 */
 874	if (intf == ncm->ctrl_id) {
 875		if (alt != 0)
 876			goto fail;
 877
 878		DBG(cdev, "reset ncm control %d\n", intf);
 879		usb_ep_disable(ncm->notify);
 880
 881		if (!(ncm->notify->desc)) {
 882			DBG(cdev, "init ncm ctrl %d\n", intf);
 883			if (config_ep_by_speed(cdev->gadget, f, ncm->notify))
 884				goto fail;
 885		}
 886		usb_ep_enable(ncm->notify);
 887
 888	/* Data interface has two altsettings, 0 and 1 */
 889	} else if (intf == ncm->data_id) {
 890		if (alt > 1)
 891			goto fail;
 892
 893		if (ncm->port.in_ep->enabled) {
 894			DBG(cdev, "reset ncm\n");
 895			ncm->timer_stopping = true;
 896			ncm->netdev = NULL;
 897			gether_disconnect(&ncm->port);
 898			ncm_reset_values(ncm);
 899		}
 900
 901		/*
 902		 * CDC Network only sends data in non-default altsettings.
 903		 * Changing altsettings resets filters, statistics, etc.
 904		 */
 905		if (alt == 1) {
 906			struct net_device	*net;
 907
 908			if (!ncm->port.in_ep->desc ||
 909			    !ncm->port.out_ep->desc) {
 910				DBG(cdev, "init ncm\n");
 911				if (config_ep_by_speed(cdev->gadget, f,
 912						       ncm->port.in_ep) ||
 913				    config_ep_by_speed(cdev->gadget, f,
 914						       ncm->port.out_ep)) {
 915					ncm->port.in_ep->desc = NULL;
 916					ncm->port.out_ep->desc = NULL;
 917					goto fail;
 918				}
 919			}
 920
 921			/* TODO */
 922			/* Enable zlps by default for NCM conformance;
 923			 * override for musb_hdrc (avoids txdma ovhead)
 924			 */
 925			ncm->port.is_zlp_ok =
 926				gadget_is_zlp_supported(cdev->gadget);
 927			ncm->port.no_skb_reserve =
 928				gadget_avoids_skb_reserve(cdev->gadget);
 929			ncm->port.cdc_filter = DEFAULT_FILTER;
 930			DBG(cdev, "activate ncm\n");
 931			net = gether_connect(&ncm->port);
 932			if (IS_ERR(net))
 933				return PTR_ERR(net);
 934			ncm->netdev = net;
 935			ncm->timer_stopping = false;
 936		}
 937
 938		spin_lock(&ncm->lock);
 939		ncm_notify(ncm);
 940		spin_unlock(&ncm->lock);
 941	} else
 942		goto fail;
 943
 944	return 0;
 945fail:
 946	return -EINVAL;
 947}
 948
 949/*
 950 * Because the data interface supports multiple altsettings,
 951 * this NCM function *MUST* implement a get_alt() method.
 952 */
 953static int ncm_get_alt(struct usb_function *f, unsigned intf)
 954{
 955	struct f_ncm		*ncm = func_to_ncm(f);
 956
 957	if (intf == ncm->ctrl_id)
 958		return 0;
 959	return ncm->port.in_ep->enabled ? 1 : 0;
 960}
 961
 962static struct sk_buff *package_for_tx(struct f_ncm *ncm)
 963{
 964	__le16		*ntb_iter;
 965	struct sk_buff	*skb2 = NULL;
 966	unsigned	ndp_pad;
 967	unsigned	ndp_index;
 968	unsigned	new_len;
 969
 970	const struct ndp_parser_opts *opts = ncm->parser_opts;
 971	const int ndp_align = le16_to_cpu(ntb_parameters.wNdpInAlignment);
 972	const int dgram_idx_len = 2 * 2 * opts->dgram_item_len;
 973
 974	/* Stop the timer */
 975	hrtimer_try_to_cancel(&ncm->task_timer);
 976
 977	ndp_pad = ALIGN(ncm->skb_tx_data->len, ndp_align) -
 978			ncm->skb_tx_data->len;
 979	ndp_index = ncm->skb_tx_data->len + ndp_pad;
 980	new_len = ndp_index + dgram_idx_len + ncm->skb_tx_ndp->len;
 981
 982	/* Set the final BlockLength and wNdpIndex */
 983	ntb_iter = (void *) ncm->skb_tx_data->data;
 984	/* Increment pointer to BlockLength */
 985	ntb_iter += 2 + 1 + 1;
 986	put_ncm(&ntb_iter, opts->block_length, new_len);
 987	put_ncm(&ntb_iter, opts->ndp_index, ndp_index);
 988
 989	/* Set the final NDP wLength */
 990	new_len = opts->ndp_size +
 991			(ncm->ndp_dgram_count * dgram_idx_len);
 992	ncm->ndp_dgram_count = 0;
 993	/* Increment from start to wLength */
 994	ntb_iter = (void *) ncm->skb_tx_ndp->data;
 995	ntb_iter += 2;
 996	put_unaligned_le16(new_len, ntb_iter);
 997
 998	/* Merge the skbs */
 999	swap(skb2, ncm->skb_tx_data);
1000	if (ncm->skb_tx_data) {
1001		dev_consume_skb_any(ncm->skb_tx_data);
1002		ncm->skb_tx_data = NULL;
1003	}
1004
1005	/* Insert NDP alignment. */
1006	ntb_iter = (void *) skb_put(skb2, ndp_pad);
1007	memset(ntb_iter, 0, ndp_pad);
1008
1009	/* Copy NTB across. */
1010	ntb_iter = (void *) skb_put(skb2, ncm->skb_tx_ndp->len);
1011	memcpy(ntb_iter, ncm->skb_tx_ndp->data, ncm->skb_tx_ndp->len);
1012	dev_consume_skb_any(ncm->skb_tx_ndp);
1013	ncm->skb_tx_ndp = NULL;
1014
1015	/* Insert zero'd datagram. */
1016	ntb_iter = (void *) skb_put(skb2, dgram_idx_len);
1017	memset(ntb_iter, 0, dgram_idx_len);
1018
1019	return skb2;
1020}
1021
1022static struct sk_buff *ncm_wrap_ntb(struct gether *port,
1023				    struct sk_buff *skb)
1024{
1025	struct f_ncm	*ncm = func_to_ncm(&port->func);
1026	struct sk_buff	*skb2 = NULL;
1027	int		ncb_len = 0;
1028	__le16		*ntb_data;
1029	__le16		*ntb_ndp;
1030	int		dgram_pad;
1031
1032	unsigned	max_size = ncm->port.fixed_in_len;
1033	const struct ndp_parser_opts *opts = ncm->parser_opts;
1034	const int ndp_align = le16_to_cpu(ntb_parameters.wNdpInAlignment);
1035	const int div = le16_to_cpu(ntb_parameters.wNdpInDivisor);
1036	const int rem = le16_to_cpu(ntb_parameters.wNdpInPayloadRemainder);
1037	const int dgram_idx_len = 2 * 2 * opts->dgram_item_len;
1038
1039	if (!skb && !ncm->skb_tx_data)
1040		return NULL;
1041
1042	if (skb) {
1043		/* Add the CRC if required up front */
1044		if (ncm->is_crc) {
1045			uint32_t	crc;
1046			__le16		*crc_pos;
1047
1048			crc = ~crc32_le(~0,
1049					skb->data,
1050					skb->len);
1051			crc_pos = (void *) skb_put(skb, sizeof(uint32_t));
1052			put_unaligned_le32(crc, crc_pos);
1053		}
1054
1055		/* If the new skb is too big for the current NCM NTB then
1056		 * set the current stored skb to be sent now and clear it
1057		 * ready for new data.
1058		 * NOTE: Assume maximum align for speed of calculation.
1059		 */
1060		if (ncm->skb_tx_data
1061		    && (ncm->ndp_dgram_count >= TX_MAX_NUM_DPE
1062		    || (ncm->skb_tx_data->len +
1063		    div + rem + skb->len +
1064		    ncm->skb_tx_ndp->len + ndp_align + (2 * dgram_idx_len))
1065		    > max_size)) {
1066			skb2 = package_for_tx(ncm);
1067			if (!skb2)
1068				goto err;
1069		}
1070
1071		if (!ncm->skb_tx_data) {
1072			ncb_len = opts->nth_size;
1073			dgram_pad = ALIGN(ncb_len, div) + rem - ncb_len;
1074			ncb_len += dgram_pad;
1075
1076			/* Create a new skb for the NTH and datagrams. */
1077			ncm->skb_tx_data = alloc_skb(max_size, GFP_ATOMIC);
1078			if (!ncm->skb_tx_data)
1079				goto err;
1080
1081			ncm->skb_tx_data->dev = ncm->netdev;
1082			ntb_data = (void *) skb_put(ncm->skb_tx_data, ncb_len);
1083			memset(ntb_data, 0, ncb_len);
1084			/* dwSignature */
1085			put_unaligned_le32(opts->nth_sign, ntb_data);
1086			ntb_data += 2;
1087			/* wHeaderLength */
1088			put_unaligned_le16(opts->nth_size, ntb_data++);
1089
1090			/* Allocate an skb for storing the NDP,
1091			 * TX_MAX_NUM_DPE should easily suffice for a
1092			 * 16k packet.
1093			 */
1094			ncm->skb_tx_ndp = alloc_skb((int)(opts->ndp_size
1095						    + opts->dpe_size
1096						    * TX_MAX_NUM_DPE),
1097						    GFP_ATOMIC);
1098			if (!ncm->skb_tx_ndp)
1099				goto err;
1100
1101			ncm->skb_tx_ndp->dev = ncm->netdev;
1102			ntb_ndp = (void *) skb_put(ncm->skb_tx_ndp,
1103						    opts->ndp_size);
1104			memset(ntb_ndp, 0, ncb_len);
1105			/* dwSignature */
1106			put_unaligned_le32(ncm->ndp_sign, ntb_ndp);
1107			ntb_ndp += 2;
1108
1109			/* There is always a zeroed entry */
1110			ncm->ndp_dgram_count = 1;
1111
1112			/* Note: we skip opts->next_ndp_index */
1113		}
1114
1115		/* Delay the timer. */
1116		hrtimer_start(&ncm->task_timer, TX_TIMEOUT_NSECS,
1117			      HRTIMER_MODE_REL);
1118
1119		/* Add the datagram position entries */
1120		ntb_ndp = (void *) skb_put(ncm->skb_tx_ndp, dgram_idx_len);
1121		memset(ntb_ndp, 0, dgram_idx_len);
1122
1123		ncb_len = ncm->skb_tx_data->len;
1124		dgram_pad = ALIGN(ncb_len, div) + rem - ncb_len;
1125		ncb_len += dgram_pad;
1126
1127		/* (d)wDatagramIndex */
1128		put_ncm(&ntb_ndp, opts->dgram_item_len, ncb_len);
1129		/* (d)wDatagramLength */
1130		put_ncm(&ntb_ndp, opts->dgram_item_len, skb->len);
1131		ncm->ndp_dgram_count++;
1132
1133		/* Add the new data to the skb */
1134		ntb_data = (void *) skb_put(ncm->skb_tx_data, dgram_pad);
1135		memset(ntb_data, 0, dgram_pad);
1136		ntb_data = (void *) skb_put(ncm->skb_tx_data, skb->len);
1137		memcpy(ntb_data, skb->data, skb->len);
1138		dev_consume_skb_any(skb);
1139		skb = NULL;
1140
1141	} else if (ncm->skb_tx_data && ncm->timer_force_tx) {
1142		/* If the tx was requested because of a timeout then send */
1143		skb2 = package_for_tx(ncm);
1144		if (!skb2)
1145			goto err;
1146	}
1147
1148	return skb2;
1149
1150err:
1151	ncm->netdev->stats.tx_dropped++;
1152
1153	if (skb)
1154		dev_kfree_skb_any(skb);
1155	if (ncm->skb_tx_data)
1156		dev_kfree_skb_any(ncm->skb_tx_data);
1157	if (ncm->skb_tx_ndp)
1158		dev_kfree_skb_any(ncm->skb_tx_ndp);
1159
1160	return NULL;
1161}
1162
1163/*
1164 * This transmits the NTB if there are frames waiting.
1165 */
1166static void ncm_tx_tasklet(unsigned long data)
1167{
1168	struct f_ncm	*ncm = (void *)data;
1169
1170	if (ncm->timer_stopping)
1171		return;
1172
1173	/* Only send if data is available. */
1174	if (ncm->skb_tx_data) {
1175		ncm->timer_force_tx = true;
1176
1177		/* XXX This allowance of a NULL skb argument to ndo_start_xmit
1178		 * XXX is not sane.  The gadget layer should be redesigned so
1179		 * XXX that the dev->wrap() invocations to build SKBs is transparent
1180		 * XXX and performed in some way outside of the ndo_start_xmit
1181		 * XXX interface.
1182		 */
1183		ncm->netdev->netdev_ops->ndo_start_xmit(NULL, ncm->netdev);
1184
1185		ncm->timer_force_tx = false;
1186	}
1187}
1188
1189/*
1190 * The transmit should only be run if no skb data has been sent
1191 * for a certain duration.
1192 */
1193static enum hrtimer_restart ncm_tx_timeout(struct hrtimer *data)
1194{
1195	struct f_ncm *ncm = container_of(data, struct f_ncm, task_timer);
1196	tasklet_schedule(&ncm->tx_tasklet);
1197	return HRTIMER_NORESTART;
1198}
1199
1200static int ncm_unwrap_ntb(struct gether *port,
1201			  struct sk_buff *skb,
1202			  struct sk_buff_head *list)
1203{
1204	struct f_ncm	*ncm = func_to_ncm(&port->func);
1205	__le16		*tmp = (void *) skb->data;
1206	unsigned	index, index2;
1207	int		ndp_index;
1208	unsigned	dg_len, dg_len2;
1209	unsigned	ndp_len;
1210	struct sk_buff	*skb2;
1211	int		ret = -EINVAL;
1212	unsigned	max_size = le32_to_cpu(ntb_parameters.dwNtbOutMaxSize);
1213	const struct ndp_parser_opts *opts = ncm->parser_opts;
1214	unsigned	crc_len = ncm->is_crc ? sizeof(uint32_t) : 0;
1215	int		dgram_counter;
1216
1217	/* dwSignature */
1218	if (get_unaligned_le32(tmp) != opts->nth_sign) {
1219		INFO(port->func.config->cdev, "Wrong NTH SIGN, skblen %d\n",
1220			skb->len);
1221		print_hex_dump(KERN_INFO, "HEAD:", DUMP_PREFIX_ADDRESS, 32, 1,
1222			       skb->data, 32, false);
1223
1224		goto err;
1225	}
1226	tmp += 2;
1227	/* wHeaderLength */
1228	if (get_unaligned_le16(tmp++) != opts->nth_size) {
1229		INFO(port->func.config->cdev, "Wrong NTB headersize\n");
1230		goto err;
1231	}
1232	tmp++; /* skip wSequence */
1233
1234	/* (d)wBlockLength */
1235	if (get_ncm(&tmp, opts->block_length) > max_size) {
1236		INFO(port->func.config->cdev, "OUT size exceeded\n");
1237		goto err;
1238	}
1239
1240	ndp_index = get_ncm(&tmp, opts->ndp_index);
1241
1242	/* Run through all the NDP's in the NTB */
1243	do {
1244		/* NCM 3.2 */
1245		if (((ndp_index % 4) != 0) &&
1246				(ndp_index < opts->nth_size)) {
1247			INFO(port->func.config->cdev, "Bad index: %#X\n",
1248			     ndp_index);
1249			goto err;
1250		}
1251
1252		/* walk through NDP */
1253		tmp = (void *)(skb->data + ndp_index);
1254		if (get_unaligned_le32(tmp) != ncm->ndp_sign) {
1255			INFO(port->func.config->cdev, "Wrong NDP SIGN\n");
1256			goto err;
1257		}
1258		tmp += 2;
1259
1260		ndp_len = get_unaligned_le16(tmp++);
1261		/*
1262		 * NCM 3.3.1
1263		 * entry is 2 items
1264		 * item size is 16/32 bits, opts->dgram_item_len * 2 bytes
1265		 * minimal: struct usb_cdc_ncm_ndpX + normal entry + zero entry
1266		 * Each entry is a dgram index and a dgram length.
1267		 */
1268		if ((ndp_len < opts->ndp_size
1269				+ 2 * 2 * (opts->dgram_item_len * 2))
1270				|| (ndp_len % opts->ndplen_align != 0)) {
1271			INFO(port->func.config->cdev, "Bad NDP length: %#X\n",
1272			     ndp_len);
1273			goto err;
1274		}
1275		tmp += opts->reserved1;
1276		/* Check for another NDP (d)wNextNdpIndex */
1277		ndp_index = get_ncm(&tmp, opts->next_ndp_index);
1278		tmp += opts->reserved2;
1279
1280		ndp_len -= opts->ndp_size;
1281		index2 = get_ncm(&tmp, opts->dgram_item_len);
1282		dg_len2 = get_ncm(&tmp, opts->dgram_item_len);
1283		dgram_counter = 0;
1284
1285		do {
1286			index = index2;
1287			dg_len = dg_len2;
1288			if (dg_len < 14 + crc_len) { /* ethernet hdr + crc */
1289				INFO(port->func.config->cdev,
1290				     "Bad dgram length: %#X\n", dg_len);
1291				goto err;
1292			}
1293			if (ncm->is_crc) {
1294				uint32_t crc, crc2;
1295
1296				crc = get_unaligned_le32(skb->data +
1297							 index + dg_len -
1298							 crc_len);
1299				crc2 = ~crc32_le(~0,
1300						 skb->data + index,
1301						 dg_len - crc_len);
1302				if (crc != crc2) {
1303					INFO(port->func.config->cdev,
1304					     "Bad CRC\n");
1305					goto err;
1306				}
1307			}
1308
1309			index2 = get_ncm(&tmp, opts->dgram_item_len);
1310			dg_len2 = get_ncm(&tmp, opts->dgram_item_len);
1311
1312			/*
1313			 * Copy the data into a new skb.
1314			 * This ensures the truesize is correct
1315			 */
1316			skb2 = netdev_alloc_skb_ip_align(ncm->netdev,
1317							 dg_len - crc_len);
1318			if (skb2 == NULL)
1319				goto err;
1320			memcpy(skb_put(skb2, dg_len - crc_len),
1321			       skb->data + index, dg_len - crc_len);
1322
1323			skb_queue_tail(list, skb2);
1324
1325			ndp_len -= 2 * (opts->dgram_item_len * 2);
1326
1327			dgram_counter++;
1328
1329			if (index2 == 0 || dg_len2 == 0)
1330				break;
1331		} while (ndp_len > 2 * (opts->dgram_item_len * 2));
1332	} while (ndp_index);
1333
1334	dev_consume_skb_any(skb);
1335
1336	VDBG(port->func.config->cdev,
1337	     "Parsed NTB with %d frames\n", dgram_counter);
1338	return 0;
1339err:
1340	skb_queue_purge(list);
1341	dev_kfree_skb_any(skb);
1342	return ret;
1343}
1344
1345static void ncm_disable(struct usb_function *f)
1346{
1347	struct f_ncm		*ncm = func_to_ncm(f);
1348	struct usb_composite_dev *cdev = f->config->cdev;
1349
1350	DBG(cdev, "ncm deactivated\n");
1351
1352	if (ncm->port.in_ep->enabled) {
1353		ncm->timer_stopping = true;
1354		ncm->netdev = NULL;
1355		gether_disconnect(&ncm->port);
1356	}
1357
1358	if (ncm->notify->enabled) {
1359		usb_ep_disable(ncm->notify);
1360		ncm->notify->desc = NULL;
1361	}
1362}
1363
1364/*-------------------------------------------------------------------------*/
1365
1366/*
1367 * Callbacks let us notify the host about connect/disconnect when the
1368 * net device is opened or closed.
1369 *
1370 * For testing, note that link states on this side include both opened
1371 * and closed variants of:
1372 *
1373 *   - disconnected/unconfigured
1374 *   - configured but inactive (data alt 0)
1375 *   - configured and active (data alt 1)
1376 *
1377 * Each needs to be tested with unplug, rmmod, SET_CONFIGURATION, and
1378 * SET_INTERFACE (altsetting).  Remember also that "configured" doesn't
1379 * imply the host is actually polling the notification endpoint, and
1380 * likewise that "active" doesn't imply it's actually using the data
1381 * endpoints for traffic.
1382 */
1383
1384static void ncm_open(struct gether *geth)
1385{
1386	struct f_ncm		*ncm = func_to_ncm(&geth->func);
1387
1388	DBG(ncm->port.func.config->cdev, "%s\n", __func__);
1389
1390	spin_lock(&ncm->lock);
1391	ncm->is_open = true;
1392	ncm_notify(ncm);
1393	spin_unlock(&ncm->lock);
1394}
1395
1396static void ncm_close(struct gether *geth)
1397{
1398	struct f_ncm		*ncm = func_to_ncm(&geth->func);
1399
1400	DBG(ncm->port.func.config->cdev, "%s\n", __func__);
1401
1402	spin_lock(&ncm->lock);
1403	ncm->is_open = false;
1404	ncm_notify(ncm);
1405	spin_unlock(&ncm->lock);
1406}
1407
1408/*-------------------------------------------------------------------------*/
1409
1410/* ethernet function driver setup/binding */
1411
1412static int ncm_bind(struct usb_configuration *c, struct usb_function *f)
1413{
1414	struct usb_composite_dev *cdev = c->cdev;
1415	struct f_ncm		*ncm = func_to_ncm(f);
1416	struct usb_string	*us;
1417	int			status;
1418	struct usb_ep		*ep;
1419	struct f_ncm_opts	*ncm_opts;
1420
1421	if (!can_support_ecm(cdev->gadget))
1422		return -EINVAL;
1423
1424	ncm_opts = container_of(f->fi, struct f_ncm_opts, func_inst);
1425	/*
1426	 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
1427	 * configurations are bound in sequence with list_for_each_entry,
1428	 * in each configuration its functions are bound in sequence
1429	 * with list_for_each_entry, so we assume no race condition
1430	 * with regard to ncm_opts->bound access
1431	 */
1432	if (!ncm_opts->bound) {
1433		mutex_lock(&ncm_opts->lock);
1434		gether_set_gadget(ncm_opts->net, cdev->gadget);
1435		status = gether_register_netdev(ncm_opts->net);
1436		mutex_unlock(&ncm_opts->lock);
1437		if (status)
1438			return status;
1439		ncm_opts->bound = true;
1440	}
1441	us = usb_gstrings_attach(cdev, ncm_strings,
1442				 ARRAY_SIZE(ncm_string_defs));
1443	if (IS_ERR(us))
1444		return PTR_ERR(us);
1445	ncm_control_intf.iInterface = us[STRING_CTRL_IDX].id;
1446	ncm_data_nop_intf.iInterface = us[STRING_DATA_IDX].id;
1447	ncm_data_intf.iInterface = us[STRING_DATA_IDX].id;
1448	ecm_desc.iMACAddress = us[STRING_MAC_IDX].id;
1449	ncm_iad_desc.iFunction = us[STRING_IAD_IDX].id;
1450
1451	/* allocate instance-specific interface IDs */
1452	status = usb_interface_id(c, f);
1453	if (status < 0)
1454		goto fail;
1455	ncm->ctrl_id = status;
1456	ncm_iad_desc.bFirstInterface = status;
1457
1458	ncm_control_intf.bInterfaceNumber = status;
1459	ncm_union_desc.bMasterInterface0 = status;
1460
1461	status = usb_interface_id(c, f);
1462	if (status < 0)
1463		goto fail;
1464	ncm->data_id = status;
1465
1466	ncm_data_nop_intf.bInterfaceNumber = status;
1467	ncm_data_intf.bInterfaceNumber = status;
1468	ncm_union_desc.bSlaveInterface0 = status;
1469
1470	status = -ENODEV;
1471
1472	/* allocate instance-specific endpoints */
1473	ep = usb_ep_autoconfig(cdev->gadget, &fs_ncm_in_desc);
1474	if (!ep)
1475		goto fail;
1476	ncm->port.in_ep = ep;
1477
1478	ep = usb_ep_autoconfig(cdev->gadget, &fs_ncm_out_desc);
1479	if (!ep)
1480		goto fail;
1481	ncm->port.out_ep = ep;
1482
1483	ep = usb_ep_autoconfig(cdev->gadget, &fs_ncm_notify_desc);
1484	if (!ep)
1485		goto fail;
1486	ncm->notify = ep;
1487
1488	status = -ENOMEM;
1489
1490	/* allocate notification request and buffer */
1491	ncm->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
1492	if (!ncm->notify_req)
1493		goto fail;
1494	ncm->notify_req->buf = kmalloc(NCM_STATUS_BYTECOUNT, GFP_KERNEL);
1495	if (!ncm->notify_req->buf)
1496		goto fail;
1497	ncm->notify_req->context = ncm;
1498	ncm->notify_req->complete = ncm_notify_complete;
1499
1500	/*
1501	 * support all relevant hardware speeds... we expect that when
1502	 * hardware is dual speed, all bulk-capable endpoints work at
1503	 * both speeds
1504	 */
1505	hs_ncm_in_desc.bEndpointAddress = fs_ncm_in_desc.bEndpointAddress;
1506	hs_ncm_out_desc.bEndpointAddress = fs_ncm_out_desc.bEndpointAddress;
1507	hs_ncm_notify_desc.bEndpointAddress =
1508		fs_ncm_notify_desc.bEndpointAddress;
1509
1510	ss_ncm_in_desc.bEndpointAddress = fs_ncm_in_desc.bEndpointAddress;
1511	ss_ncm_out_desc.bEndpointAddress = fs_ncm_out_desc.bEndpointAddress;
1512	ss_ncm_notify_desc.bEndpointAddress =
1513		fs_ncm_notify_desc.bEndpointAddress;
1514
1515	status = usb_assign_descriptors(f, ncm_fs_function, ncm_hs_function,
1516			ncm_ss_function, NULL);
1517	if (status)
1518		goto fail;
1519
1520	/*
1521	 * NOTE:  all that is done without knowing or caring about
1522	 * the network link ... which is unavailable to this code
1523	 * until we're activated via set_alt().
1524	 */
1525
1526	ncm->port.open = ncm_open;
1527	ncm->port.close = ncm_close;
1528
1529	tasklet_init(&ncm->tx_tasklet, ncm_tx_tasklet, (unsigned long) ncm);
1530	hrtimer_init(&ncm->task_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1531	ncm->task_timer.function = ncm_tx_timeout;
1532
1533	DBG(cdev, "CDC Network: %s speed IN/%s OUT/%s NOTIFY/%s\n",
1534			gadget_is_superspeed(c->cdev->gadget) ? "super" :
1535			gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
1536			ncm->port.in_ep->name, ncm->port.out_ep->name,
1537			ncm->notify->name);
1538	return 0;
1539
1540fail:
1541	if (ncm->notify_req) {
1542		kfree(ncm->notify_req->buf);
1543		usb_ep_free_request(ncm->notify, ncm->notify_req);
1544	}
1545
1546	ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
1547
1548	return status;
1549}
1550
1551static inline struct f_ncm_opts *to_f_ncm_opts(struct config_item *item)
1552{
1553	return container_of(to_config_group(item), struct f_ncm_opts,
1554			    func_inst.group);
1555}
1556
1557/* f_ncm_item_ops */
1558USB_ETHERNET_CONFIGFS_ITEM(ncm);
1559
1560/* f_ncm_opts_dev_addr */
1561USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(ncm);
1562
1563/* f_ncm_opts_host_addr */
1564USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(ncm);
1565
1566/* f_ncm_opts_qmult */
1567USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(ncm);
1568
1569/* f_ncm_opts_ifname */
1570USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(ncm);
1571
1572static struct configfs_attribute *ncm_attrs[] = {
1573	&ncm_opts_attr_dev_addr,
1574	&ncm_opts_attr_host_addr,
1575	&ncm_opts_attr_qmult,
1576	&ncm_opts_attr_ifname,
1577	NULL,
1578};
1579
1580static struct config_item_type ncm_func_type = {
1581	.ct_item_ops	= &ncm_item_ops,
1582	.ct_attrs	= ncm_attrs,
1583	.ct_owner	= THIS_MODULE,
1584};
1585
1586static void ncm_free_inst(struct usb_function_instance *f)
1587{
1588	struct f_ncm_opts *opts;
1589
1590	opts = container_of(f, struct f_ncm_opts, func_inst);
1591	if (opts->bound)
1592		gether_cleanup(netdev_priv(opts->net));
1593	else
1594		free_netdev(opts->net);
1595	kfree(opts);
1596}
1597
1598static struct usb_function_instance *ncm_alloc_inst(void)
1599{
1600	struct f_ncm_opts *opts;
1601
1602	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1603	if (!opts)
1604		return ERR_PTR(-ENOMEM);
1605	mutex_init(&opts->lock);
1606	opts->func_inst.free_func_inst = ncm_free_inst;
1607	opts->net = gether_setup_default();
1608	if (IS_ERR(opts->net)) {
1609		struct net_device *net = opts->net;
1610		kfree(opts);
1611		return ERR_CAST(net);
1612	}
1613
1614	config_group_init_type_name(&opts->func_inst.group, "", &ncm_func_type);
1615
1616	return &opts->func_inst;
1617}
1618
1619static void ncm_free(struct usb_function *f)
1620{
1621	struct f_ncm *ncm;
1622	struct f_ncm_opts *opts;
1623
1624	ncm = func_to_ncm(f);
1625	opts = container_of(f->fi, struct f_ncm_opts, func_inst);
1626	kfree(ncm);
1627	mutex_lock(&opts->lock);
1628	opts->refcnt--;
1629	mutex_unlock(&opts->lock);
1630}
1631
1632static void ncm_unbind(struct usb_configuration *c, struct usb_function *f)
1633{
1634	struct f_ncm *ncm = func_to_ncm(f);
1635
1636	DBG(c->cdev, "ncm unbind\n");
1637
1638	hrtimer_cancel(&ncm->task_timer);
1639	tasklet_kill(&ncm->tx_tasklet);
1640
1641	ncm_string_defs[0].id = 0;
1642	usb_free_all_descriptors(f);
1643
1644	kfree(ncm->notify_req->buf);
1645	usb_ep_free_request(ncm->notify, ncm->notify_req);
1646}
1647
1648static struct usb_function *ncm_alloc(struct usb_function_instance *fi)
1649{
1650	struct f_ncm		*ncm;
1651	struct f_ncm_opts	*opts;
1652	int status;
1653
1654	/* allocate and initialize one new instance */
1655	ncm = kzalloc(sizeof(*ncm), GFP_KERNEL);
1656	if (!ncm)
1657		return ERR_PTR(-ENOMEM);
1658
1659	opts = container_of(fi, struct f_ncm_opts, func_inst);
1660	mutex_lock(&opts->lock);
1661	opts->refcnt++;
1662
1663	/* export host's Ethernet address in CDC format */
1664	status = gether_get_host_addr_cdc(opts->net, ncm->ethaddr,
1665				      sizeof(ncm->ethaddr));
1666	if (status < 12) { /* strlen("01234567890a") */
1667		kfree(ncm);
1668		mutex_unlock(&opts->lock);
1669		return ERR_PTR(-EINVAL);
1670	}
1671	ncm_string_defs[STRING_MAC_IDX].s = ncm->ethaddr;
1672
1673	spin_lock_init(&ncm->lock);
1674	ncm_reset_values(ncm);
1675	ncm->port.ioport = netdev_priv(opts->net);
1676	mutex_unlock(&opts->lock);
1677	ncm->port.is_fixed = true;
1678	ncm->port.supports_multi_frame = true;
1679
1680	ncm->port.func.name = "cdc_network";
1681	/* descriptors are per-instance copies */
1682	ncm->port.func.bind = ncm_bind;
1683	ncm->port.func.unbind = ncm_unbind;
1684	ncm->port.func.set_alt = ncm_set_alt;
1685	ncm->port.func.get_alt = ncm_get_alt;
1686	ncm->port.func.setup = ncm_setup;
1687	ncm->port.func.disable = ncm_disable;
1688	ncm->port.func.free_func = ncm_free;
1689
1690	ncm->port.wrap = ncm_wrap_ntb;
1691	ncm->port.unwrap = ncm_unwrap_ntb;
1692
1693	return &ncm->port.func;
1694}
1695
1696DECLARE_USB_FUNCTION_INIT(ncm, ncm_alloc_inst, ncm_alloc);
1697MODULE_LICENSE("GPL");
1698MODULE_AUTHOR("Yauheni Kaliuta");