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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 
45 enum 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 
51 struct 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 	atomic_t			notify_count;
61 	bool				is_open;
62 
63 	const struct ndp_parser_opts	*parser_opts;
64 	bool				is_crc;
65 	u32				ndp_sign;
66 
67 	/*
68 	 * for notification, it is accessed from both
69 	 * callback and ethernet open/close
70 	 */
71 	spinlock_t			lock;
72 
73 	struct net_device		*netdev;
74 
75 	/* For multi-frame NDP TX */
76 	struct sk_buff			*skb_tx_data;
77 	struct sk_buff			*skb_tx_ndp;
78 	u16				ndp_dgram_count;
79 	bool				timer_force_tx;
80 	struct tasklet_struct		tx_tasklet;
81 	struct hrtimer			task_timer;
82 
83 	bool				timer_stopping;
84 };
85 
func_to_ncm(struct usb_function * f)86 static inline struct f_ncm *func_to_ncm(struct usb_function *f)
87 {
88 	return container_of(f, struct f_ncm, port.func);
89 }
90 
91 /* peak (theoretical) bulk transfer rate in bits-per-second */
ncm_bitrate(struct usb_gadget * g)92 static inline unsigned ncm_bitrate(struct usb_gadget *g)
93 {
94 	if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
95 		return 13 * 512 * 8 * 1000 * 8;
96 	else
97 		return 19 *  64 * 1 * 1000 * 8;
98 }
99 
100 /*-------------------------------------------------------------------------*/
101 
102 /*
103  * We cannot group frames so use just the minimal size which ok to put
104  * one max-size ethernet frame.
105  * If the host can group frames, allow it to do that, 16K is selected,
106  * because it's used by default by the current linux host driver
107  */
108 #define NTB_DEFAULT_IN_SIZE	16384
109 #define NTB_OUT_SIZE		16384
110 
111 /* Allocation for storing the NDP, 32 should suffice for a
112  * 16k packet. This allows a maximum of 32 * 507 Byte packets to
113  * be transmitted in a single 16kB skb, though when sending full size
114  * packets this limit will be plenty.
115  * Smaller packets are not likely to be trying to maximize the
116  * throughput and will be mstly sending smaller infrequent frames.
117  */
118 #define TX_MAX_NUM_DPE		32
119 
120 /* Delay for the transmit to wait before sending an unfilled NTB frame. */
121 #define TX_TIMEOUT_NSECS	300000
122 
123 #define FORMATS_SUPPORTED	(USB_CDC_NCM_NTB16_SUPPORTED |	\
124 				 USB_CDC_NCM_NTB32_SUPPORTED)
125 
126 static struct usb_cdc_ncm_ntb_parameters ntb_parameters = {
127 	.wLength = cpu_to_le16(sizeof(ntb_parameters)),
128 	.bmNtbFormatsSupported = cpu_to_le16(FORMATS_SUPPORTED),
129 	.dwNtbInMaxSize = cpu_to_le32(NTB_DEFAULT_IN_SIZE),
130 	.wNdpInDivisor = cpu_to_le16(4),
131 	.wNdpInPayloadRemainder = cpu_to_le16(0),
132 	.wNdpInAlignment = cpu_to_le16(4),
133 
134 	.dwNtbOutMaxSize = cpu_to_le32(NTB_OUT_SIZE),
135 	.wNdpOutDivisor = cpu_to_le16(4),
136 	.wNdpOutPayloadRemainder = cpu_to_le16(0),
137 	.wNdpOutAlignment = cpu_to_le16(4),
138 };
139 
140 /*
141  * Use wMaxPacketSize big enough to fit CDC_NOTIFY_SPEED_CHANGE in one
142  * packet, to simplify cancellation; and a big transfer interval, to
143  * waste less bandwidth.
144  */
145 
146 #define NCM_STATUS_INTERVAL_MS		32
147 #define NCM_STATUS_BYTECOUNT		16	/* 8 byte header + data */
148 
149 static struct usb_interface_assoc_descriptor ncm_iad_desc = {
150 	.bLength =		sizeof ncm_iad_desc,
151 	.bDescriptorType =	USB_DT_INTERFACE_ASSOCIATION,
152 
153 	/* .bFirstInterface =	DYNAMIC, */
154 	.bInterfaceCount =	2,	/* control + data */
155 	.bFunctionClass =	USB_CLASS_COMM,
156 	.bFunctionSubClass =	USB_CDC_SUBCLASS_NCM,
157 	.bFunctionProtocol =	USB_CDC_PROTO_NONE,
158 	/* .iFunction =		DYNAMIC */
159 };
160 
161 /* interface descriptor: */
162 
163 static struct usb_interface_descriptor ncm_control_intf = {
164 	.bLength =		sizeof ncm_control_intf,
165 	.bDescriptorType =	USB_DT_INTERFACE,
166 
167 	/* .bInterfaceNumber = DYNAMIC */
168 	.bNumEndpoints =	1,
169 	.bInterfaceClass =	USB_CLASS_COMM,
170 	.bInterfaceSubClass =	USB_CDC_SUBCLASS_NCM,
171 	.bInterfaceProtocol =	USB_CDC_PROTO_NONE,
172 	/* .iInterface = DYNAMIC */
173 };
174 
175 static struct usb_cdc_header_desc ncm_header_desc = {
176 	.bLength =		sizeof ncm_header_desc,
177 	.bDescriptorType =	USB_DT_CS_INTERFACE,
178 	.bDescriptorSubType =	USB_CDC_HEADER_TYPE,
179 
180 	.bcdCDC =		cpu_to_le16(0x0110),
181 };
182 
183 static struct usb_cdc_union_desc ncm_union_desc = {
184 	.bLength =		sizeof(ncm_union_desc),
185 	.bDescriptorType =	USB_DT_CS_INTERFACE,
186 	.bDescriptorSubType =	USB_CDC_UNION_TYPE,
187 	/* .bMasterInterface0 =	DYNAMIC */
188 	/* .bSlaveInterface0 =	DYNAMIC */
189 };
190 
191 static struct usb_cdc_ether_desc ecm_desc = {
192 	.bLength =		sizeof ecm_desc,
193 	.bDescriptorType =	USB_DT_CS_INTERFACE,
194 	.bDescriptorSubType =	USB_CDC_ETHERNET_TYPE,
195 
196 	/* this descriptor actually adds value, surprise! */
197 	/* .iMACAddress = DYNAMIC */
198 	.bmEthernetStatistics =	cpu_to_le32(0), /* no statistics */
199 	.wMaxSegmentSize =	cpu_to_le16(ETH_FRAME_LEN),
200 	.wNumberMCFilters =	cpu_to_le16(0),
201 	.bNumberPowerFilters =	0,
202 };
203 
204 #define NCAPS	(USB_CDC_NCM_NCAP_ETH_FILTER | USB_CDC_NCM_NCAP_CRC_MODE)
205 
206 static struct usb_cdc_ncm_desc ncm_desc = {
207 	.bLength =		sizeof ncm_desc,
208 	.bDescriptorType =	USB_DT_CS_INTERFACE,
209 	.bDescriptorSubType =	USB_CDC_NCM_TYPE,
210 
211 	.bcdNcmVersion =	cpu_to_le16(0x0100),
212 	/* can process SetEthernetPacketFilter */
213 	.bmNetworkCapabilities = NCAPS,
214 };
215 
216 /* the default data interface has no endpoints ... */
217 
218 static struct usb_interface_descriptor ncm_data_nop_intf = {
219 	.bLength =		sizeof ncm_data_nop_intf,
220 	.bDescriptorType =	USB_DT_INTERFACE,
221 
222 	.bInterfaceNumber =	1,
223 	.bAlternateSetting =	0,
224 	.bNumEndpoints =	0,
225 	.bInterfaceClass =	USB_CLASS_CDC_DATA,
226 	.bInterfaceSubClass =	0,
227 	.bInterfaceProtocol =	USB_CDC_NCM_PROTO_NTB,
228 	/* .iInterface = DYNAMIC */
229 };
230 
231 /* ... but the "real" data interface has two bulk endpoints */
232 
233 static struct usb_interface_descriptor ncm_data_intf = {
234 	.bLength =		sizeof ncm_data_intf,
235 	.bDescriptorType =	USB_DT_INTERFACE,
236 
237 	.bInterfaceNumber =	1,
238 	.bAlternateSetting =	1,
239 	.bNumEndpoints =	2,
240 	.bInterfaceClass =	USB_CLASS_CDC_DATA,
241 	.bInterfaceSubClass =	0,
242 	.bInterfaceProtocol =	USB_CDC_NCM_PROTO_NTB,
243 	/* .iInterface = DYNAMIC */
244 };
245 
246 /* full speed support: */
247 
248 static struct usb_endpoint_descriptor fs_ncm_notify_desc = {
249 	.bLength =		USB_DT_ENDPOINT_SIZE,
250 	.bDescriptorType =	USB_DT_ENDPOINT,
251 
252 	.bEndpointAddress =	USB_DIR_IN,
253 	.bmAttributes =		USB_ENDPOINT_XFER_INT,
254 	.wMaxPacketSize =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
255 	.bInterval =		NCM_STATUS_INTERVAL_MS,
256 };
257 
258 static struct usb_endpoint_descriptor fs_ncm_in_desc = {
259 	.bLength =		USB_DT_ENDPOINT_SIZE,
260 	.bDescriptorType =	USB_DT_ENDPOINT,
261 
262 	.bEndpointAddress =	USB_DIR_IN,
263 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
264 };
265 
266 static struct usb_endpoint_descriptor fs_ncm_out_desc = {
267 	.bLength =		USB_DT_ENDPOINT_SIZE,
268 	.bDescriptorType =	USB_DT_ENDPOINT,
269 
270 	.bEndpointAddress =	USB_DIR_OUT,
271 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
272 };
273 
274 static struct usb_descriptor_header *ncm_fs_function[] = {
275 	(struct usb_descriptor_header *) &ncm_iad_desc,
276 	/* CDC NCM control descriptors */
277 	(struct usb_descriptor_header *) &ncm_control_intf,
278 	(struct usb_descriptor_header *) &ncm_header_desc,
279 	(struct usb_descriptor_header *) &ncm_union_desc,
280 	(struct usb_descriptor_header *) &ecm_desc,
281 	(struct usb_descriptor_header *) &ncm_desc,
282 	(struct usb_descriptor_header *) &fs_ncm_notify_desc,
283 	/* data interface, altsettings 0 and 1 */
284 	(struct usb_descriptor_header *) &ncm_data_nop_intf,
285 	(struct usb_descriptor_header *) &ncm_data_intf,
286 	(struct usb_descriptor_header *) &fs_ncm_in_desc,
287 	(struct usb_descriptor_header *) &fs_ncm_out_desc,
288 	NULL,
289 };
290 
291 /* high speed support: */
292 
293 static struct usb_endpoint_descriptor hs_ncm_notify_desc = {
294 	.bLength =		USB_DT_ENDPOINT_SIZE,
295 	.bDescriptorType =	USB_DT_ENDPOINT,
296 
297 	.bEndpointAddress =	USB_DIR_IN,
298 	.bmAttributes =		USB_ENDPOINT_XFER_INT,
299 	.wMaxPacketSize =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
300 	.bInterval =		USB_MS_TO_HS_INTERVAL(NCM_STATUS_INTERVAL_MS),
301 };
302 static struct usb_endpoint_descriptor hs_ncm_in_desc = {
303 	.bLength =		USB_DT_ENDPOINT_SIZE,
304 	.bDescriptorType =	USB_DT_ENDPOINT,
305 
306 	.bEndpointAddress =	USB_DIR_IN,
307 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
308 	.wMaxPacketSize =	cpu_to_le16(512),
309 };
310 
311 static struct usb_endpoint_descriptor hs_ncm_out_desc = {
312 	.bLength =		USB_DT_ENDPOINT_SIZE,
313 	.bDescriptorType =	USB_DT_ENDPOINT,
314 
315 	.bEndpointAddress =	USB_DIR_OUT,
316 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
317 	.wMaxPacketSize =	cpu_to_le16(512),
318 };
319 
320 static struct usb_descriptor_header *ncm_hs_function[] = {
321 	(struct usb_descriptor_header *) &ncm_iad_desc,
322 	/* CDC NCM control descriptors */
323 	(struct usb_descriptor_header *) &ncm_control_intf,
324 	(struct usb_descriptor_header *) &ncm_header_desc,
325 	(struct usb_descriptor_header *) &ncm_union_desc,
326 	(struct usb_descriptor_header *) &ecm_desc,
327 	(struct usb_descriptor_header *) &ncm_desc,
328 	(struct usb_descriptor_header *) &hs_ncm_notify_desc,
329 	/* data interface, altsettings 0 and 1 */
330 	(struct usb_descriptor_header *) &ncm_data_nop_intf,
331 	(struct usb_descriptor_header *) &ncm_data_intf,
332 	(struct usb_descriptor_header *) &hs_ncm_in_desc,
333 	(struct usb_descriptor_header *) &hs_ncm_out_desc,
334 	NULL,
335 };
336 
337 /* string descriptors: */
338 
339 #define STRING_CTRL_IDX	0
340 #define STRING_MAC_IDX	1
341 #define STRING_DATA_IDX	2
342 #define STRING_IAD_IDX	3
343 
344 static struct usb_string ncm_string_defs[] = {
345 	[STRING_CTRL_IDX].s = "CDC Network Control Model (NCM)",
346 	[STRING_MAC_IDX].s = "",
347 	[STRING_DATA_IDX].s = "CDC Network Data",
348 	[STRING_IAD_IDX].s = "CDC NCM",
349 	{  } /* end of list */
350 };
351 
352 static struct usb_gadget_strings ncm_string_table = {
353 	.language =		0x0409,	/* en-us */
354 	.strings =		ncm_string_defs,
355 };
356 
357 static struct usb_gadget_strings *ncm_strings[] = {
358 	&ncm_string_table,
359 	NULL,
360 };
361 
362 /*
363  * Here are options for NCM Datagram Pointer table (NDP) parser.
364  * There are 2 different formats: NDP16 and NDP32 in the spec (ch. 3),
365  * in NDP16 offsets and sizes fields are 1 16bit word wide,
366  * in NDP32 -- 2 16bit words wide. Also signatures are different.
367  * To make the parser code the same, put the differences in the structure,
368  * and switch pointers to the structures when the format is changed.
369  */
370 
371 struct ndp_parser_opts {
372 	u32		nth_sign;
373 	u32		ndp_sign;
374 	unsigned	nth_size;
375 	unsigned	ndp_size;
376 	unsigned	dpe_size;
377 	unsigned	ndplen_align;
378 	/* sizes in u16 units */
379 	unsigned	dgram_item_len; /* index or length */
380 	unsigned	block_length;
381 	unsigned	ndp_index;
382 	unsigned	reserved1;
383 	unsigned	reserved2;
384 	unsigned	next_ndp_index;
385 };
386 
387 #define INIT_NDP16_OPTS {					\
388 		.nth_sign = USB_CDC_NCM_NTH16_SIGN,		\
389 		.ndp_sign = USB_CDC_NCM_NDP16_NOCRC_SIGN,	\
390 		.nth_size = sizeof(struct usb_cdc_ncm_nth16),	\
391 		.ndp_size = sizeof(struct usb_cdc_ncm_ndp16),	\
392 		.dpe_size = sizeof(struct usb_cdc_ncm_dpe16),	\
393 		.ndplen_align = 4,				\
394 		.dgram_item_len = 1,				\
395 		.block_length = 1,				\
396 		.ndp_index = 1,					\
397 		.reserved1 = 0,					\
398 		.reserved2 = 0,					\
399 		.next_ndp_index = 1,				\
400 	}
401 
402 
403 #define INIT_NDP32_OPTS {					\
404 		.nth_sign = USB_CDC_NCM_NTH32_SIGN,		\
405 		.ndp_sign = USB_CDC_NCM_NDP32_NOCRC_SIGN,	\
406 		.nth_size = sizeof(struct usb_cdc_ncm_nth32),	\
407 		.ndp_size = sizeof(struct usb_cdc_ncm_ndp32),	\
408 		.dpe_size = sizeof(struct usb_cdc_ncm_dpe32),	\
409 		.ndplen_align = 8,				\
410 		.dgram_item_len = 2,				\
411 		.block_length = 2,				\
412 		.ndp_index = 2,					\
413 		.reserved1 = 1,					\
414 		.reserved2 = 2,					\
415 		.next_ndp_index = 2,				\
416 	}
417 
418 static const struct ndp_parser_opts ndp16_opts = INIT_NDP16_OPTS;
419 static const struct ndp_parser_opts ndp32_opts = INIT_NDP32_OPTS;
420 
put_ncm(__le16 ** p,unsigned size,unsigned val)421 static inline void put_ncm(__le16 **p, unsigned size, unsigned val)
422 {
423 	switch (size) {
424 	case 1:
425 		put_unaligned_le16((u16)val, *p);
426 		break;
427 	case 2:
428 		put_unaligned_le32((u32)val, *p);
429 
430 		break;
431 	default:
432 		BUG();
433 	}
434 
435 	*p += size;
436 }
437 
get_ncm(__le16 ** p,unsigned size)438 static inline unsigned get_ncm(__le16 **p, unsigned size)
439 {
440 	unsigned tmp;
441 
442 	switch (size) {
443 	case 1:
444 		tmp = get_unaligned_le16(*p);
445 		break;
446 	case 2:
447 		tmp = get_unaligned_le32(*p);
448 		break;
449 	default:
450 		BUG();
451 	}
452 
453 	*p += size;
454 	return tmp;
455 }
456 
457 /*-------------------------------------------------------------------------*/
458 
ncm_reset_values(struct f_ncm * ncm)459 static inline void ncm_reset_values(struct f_ncm *ncm)
460 {
461 	ncm->parser_opts = &ndp16_opts;
462 	ncm->is_crc = false;
463 	ncm->port.cdc_filter = DEFAULT_FILTER;
464 
465 	/* doesn't make sense for ncm, fixed size used */
466 	ncm->port.header_len = 0;
467 
468 	ncm->port.fixed_out_len = le32_to_cpu(ntb_parameters.dwNtbOutMaxSize);
469 	ncm->port.fixed_in_len = NTB_DEFAULT_IN_SIZE;
470 }
471 
472 /*
473  * Context: ncm->lock held
474  */
ncm_do_notify(struct f_ncm * ncm)475 static void ncm_do_notify(struct f_ncm *ncm)
476 {
477 	struct usb_request		*req = ncm->notify_req;
478 	struct usb_cdc_notification	*event;
479 	struct usb_composite_dev	*cdev = ncm->port.func.config->cdev;
480 	__le32				*data;
481 	int				status;
482 
483 	/* notification already in flight? */
484 	if (atomic_read(&ncm->notify_count))
485 		return;
486 
487 	event = req->buf;
488 	switch (ncm->notify_state) {
489 	case NCM_NOTIFY_NONE:
490 		return;
491 
492 	case NCM_NOTIFY_CONNECT:
493 		event->bNotificationType = USB_CDC_NOTIFY_NETWORK_CONNECTION;
494 		if (ncm->is_open)
495 			event->wValue = cpu_to_le16(1);
496 		else
497 			event->wValue = cpu_to_le16(0);
498 		event->wLength = 0;
499 		req->length = sizeof *event;
500 
501 		DBG(cdev, "notify connect %s\n",
502 				ncm->is_open ? "true" : "false");
503 		ncm->notify_state = NCM_NOTIFY_NONE;
504 		break;
505 
506 	case NCM_NOTIFY_SPEED:
507 		event->bNotificationType = USB_CDC_NOTIFY_SPEED_CHANGE;
508 		event->wValue = cpu_to_le16(0);
509 		event->wLength = cpu_to_le16(8);
510 		req->length = NCM_STATUS_BYTECOUNT;
511 
512 		/* SPEED_CHANGE data is up/down speeds in bits/sec */
513 		data = req->buf + sizeof *event;
514 		data[0] = cpu_to_le32(ncm_bitrate(cdev->gadget));
515 		data[1] = data[0];
516 
517 		DBG(cdev, "notify speed %u\n", ncm_bitrate(cdev->gadget));
518 		ncm->notify_state = NCM_NOTIFY_CONNECT;
519 		break;
520 	}
521 	event->bmRequestType = 0xA1;
522 	event->wIndex = cpu_to_le16(ncm->ctrl_id);
523 
524 	atomic_inc(&ncm->notify_count);
525 
526 	/*
527 	 * In double buffering if there is a space in FIFO,
528 	 * completion callback can be called right after the call,
529 	 * so unlocking
530 	 */
531 	spin_unlock(&ncm->lock);
532 	status = usb_ep_queue(ncm->notify, req, GFP_ATOMIC);
533 	spin_lock(&ncm->lock);
534 	if (status < 0) {
535 		atomic_dec(&ncm->notify_count);
536 		DBG(cdev, "notify --> %d\n", status);
537 	}
538 }
539 
540 /*
541  * Context: ncm->lock held
542  */
ncm_notify(struct f_ncm * ncm)543 static void ncm_notify(struct f_ncm *ncm)
544 {
545 	/*
546 	 * NOTE on most versions of Linux, host side cdc-ethernet
547 	 * won't listen for notifications until its netdevice opens.
548 	 * The first notification then sits in the FIFO for a long
549 	 * time, and the second one is queued.
550 	 *
551 	 * If ncm_notify() is called before the second (CONNECT)
552 	 * notification is sent, then it will reset to send the SPEED
553 	 * notificaion again (and again, and again), but it's not a problem
554 	 */
555 	ncm->notify_state = NCM_NOTIFY_SPEED;
556 	ncm_do_notify(ncm);
557 }
558 
ncm_notify_complete(struct usb_ep * ep,struct usb_request * req)559 static void ncm_notify_complete(struct usb_ep *ep, struct usb_request *req)
560 {
561 	struct f_ncm			*ncm = req->context;
562 	struct usb_composite_dev	*cdev = ncm->port.func.config->cdev;
563 	struct usb_cdc_notification	*event = req->buf;
564 
565 	spin_lock(&ncm->lock);
566 	switch (req->status) {
567 	case 0:
568 		VDBG(cdev, "Notification %02x sent\n",
569 		     event->bNotificationType);
570 		atomic_dec(&ncm->notify_count);
571 		break;
572 	case -ECONNRESET:
573 	case -ESHUTDOWN:
574 		atomic_set(&ncm->notify_count, 0);
575 		ncm->notify_state = NCM_NOTIFY_NONE;
576 		break;
577 	default:
578 		DBG(cdev, "event %02x --> %d\n",
579 			event->bNotificationType, req->status);
580 		atomic_dec(&ncm->notify_count);
581 		break;
582 	}
583 	ncm_do_notify(ncm);
584 	spin_unlock(&ncm->lock);
585 }
586 
ncm_ep0out_complete(struct usb_ep * ep,struct usb_request * req)587 static void ncm_ep0out_complete(struct usb_ep *ep, struct usb_request *req)
588 {
589 	/* now for SET_NTB_INPUT_SIZE only */
590 	unsigned		in_size;
591 	struct usb_function	*f = req->context;
592 	struct f_ncm		*ncm = func_to_ncm(f);
593 	struct usb_composite_dev *cdev = f->config->cdev;
594 
595 	req->context = NULL;
596 	if (req->status || req->actual != req->length) {
597 		DBG(cdev, "Bad control-OUT transfer\n");
598 		goto invalid;
599 	}
600 
601 	in_size = get_unaligned_le32(req->buf);
602 	if (in_size < USB_CDC_NCM_NTB_MIN_IN_SIZE ||
603 	    in_size > le32_to_cpu(ntb_parameters.dwNtbInMaxSize)) {
604 		DBG(cdev, "Got wrong INPUT SIZE (%d) from host\n", in_size);
605 		goto invalid;
606 	}
607 
608 	ncm->port.fixed_in_len = in_size;
609 	VDBG(cdev, "Set NTB INPUT SIZE %d\n", in_size);
610 	return;
611 
612 invalid:
613 	usb_ep_set_halt(ep);
614 	return;
615 }
616 
ncm_setup(struct usb_function * f,const struct usb_ctrlrequest * ctrl)617 static int ncm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
618 {
619 	struct f_ncm		*ncm = func_to_ncm(f);
620 	struct usb_composite_dev *cdev = f->config->cdev;
621 	struct usb_request	*req = cdev->req;
622 	int			value = -EOPNOTSUPP;
623 	u16			w_index = le16_to_cpu(ctrl->wIndex);
624 	u16			w_value = le16_to_cpu(ctrl->wValue);
625 	u16			w_length = le16_to_cpu(ctrl->wLength);
626 
627 	/*
628 	 * composite driver infrastructure handles everything except
629 	 * CDC class messages; interface activation uses set_alt().
630 	 */
631 	switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
632 	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
633 			| USB_CDC_SET_ETHERNET_PACKET_FILTER:
634 		/*
635 		 * see 6.2.30: no data, wIndex = interface,
636 		 * wValue = packet filter bitmap
637 		 */
638 		if (w_length != 0 || w_index != ncm->ctrl_id)
639 			goto invalid;
640 		DBG(cdev, "packet filter %02x\n", w_value);
641 		/*
642 		 * REVISIT locking of cdc_filter.  This assumes the UDC
643 		 * driver won't have a concurrent packet TX irq running on
644 		 * another CPU; or that if it does, this write is atomic...
645 		 */
646 		ncm->port.cdc_filter = w_value;
647 		value = 0;
648 		break;
649 	/*
650 	 * and optionally:
651 	 * case USB_CDC_SEND_ENCAPSULATED_COMMAND:
652 	 * case USB_CDC_GET_ENCAPSULATED_RESPONSE:
653 	 * case USB_CDC_SET_ETHERNET_MULTICAST_FILTERS:
654 	 * case USB_CDC_SET_ETHERNET_PM_PATTERN_FILTER:
655 	 * case USB_CDC_GET_ETHERNET_PM_PATTERN_FILTER:
656 	 * case USB_CDC_GET_ETHERNET_STATISTIC:
657 	 */
658 
659 	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
660 		| USB_CDC_GET_NTB_PARAMETERS:
661 
662 		if (w_length == 0 || w_value != 0 || w_index != ncm->ctrl_id)
663 			goto invalid;
664 		value = w_length > sizeof ntb_parameters ?
665 			sizeof ntb_parameters : w_length;
666 		memcpy(req->buf, &ntb_parameters, value);
667 		VDBG(cdev, "Host asked NTB parameters\n");
668 		break;
669 
670 	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
671 		| USB_CDC_GET_NTB_INPUT_SIZE:
672 
673 		if (w_length < 4 || w_value != 0 || w_index != ncm->ctrl_id)
674 			goto invalid;
675 		put_unaligned_le32(ncm->port.fixed_in_len, req->buf);
676 		value = 4;
677 		VDBG(cdev, "Host asked INPUT SIZE, sending %d\n",
678 		     ncm->port.fixed_in_len);
679 		break;
680 
681 	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
682 		| USB_CDC_SET_NTB_INPUT_SIZE:
683 	{
684 		if (w_length != 4 || w_value != 0 || w_index != ncm->ctrl_id)
685 			goto invalid;
686 		req->complete = ncm_ep0out_complete;
687 		req->length = w_length;
688 		req->context = f;
689 
690 		value = req->length;
691 		break;
692 	}
693 
694 	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
695 		| USB_CDC_GET_NTB_FORMAT:
696 	{
697 		uint16_t format;
698 
699 		if (w_length < 2 || w_value != 0 || w_index != ncm->ctrl_id)
700 			goto invalid;
701 		format = (ncm->parser_opts == &ndp16_opts) ? 0x0000 : 0x0001;
702 		put_unaligned_le16(format, req->buf);
703 		value = 2;
704 		VDBG(cdev, "Host asked NTB FORMAT, sending %d\n", format);
705 		break;
706 	}
707 
708 	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
709 		| USB_CDC_SET_NTB_FORMAT:
710 	{
711 		if (w_length != 0 || w_index != ncm->ctrl_id)
712 			goto invalid;
713 		switch (w_value) {
714 		case 0x0000:
715 			ncm->parser_opts = &ndp16_opts;
716 			DBG(cdev, "NCM16 selected\n");
717 			break;
718 		case 0x0001:
719 			ncm->parser_opts = &ndp32_opts;
720 			DBG(cdev, "NCM32 selected\n");
721 			break;
722 		default:
723 			goto invalid;
724 		}
725 		value = 0;
726 		break;
727 	}
728 	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
729 		| USB_CDC_GET_CRC_MODE:
730 	{
731 		uint16_t is_crc;
732 
733 		if (w_length < 2 || w_value != 0 || w_index != ncm->ctrl_id)
734 			goto invalid;
735 		is_crc = ncm->is_crc ? 0x0001 : 0x0000;
736 		put_unaligned_le16(is_crc, req->buf);
737 		value = 2;
738 		VDBG(cdev, "Host asked CRC MODE, sending %d\n", is_crc);
739 		break;
740 	}
741 
742 	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
743 		| USB_CDC_SET_CRC_MODE:
744 	{
745 		int ndp_hdr_crc = 0;
746 
747 		if (w_length != 0 || w_index != ncm->ctrl_id)
748 			goto invalid;
749 		switch (w_value) {
750 		case 0x0000:
751 			ncm->is_crc = false;
752 			ndp_hdr_crc = NCM_NDP_HDR_NOCRC;
753 			DBG(cdev, "non-CRC mode selected\n");
754 			break;
755 		case 0x0001:
756 			ncm->is_crc = true;
757 			ndp_hdr_crc = NCM_NDP_HDR_CRC;
758 			DBG(cdev, "CRC mode selected\n");
759 			break;
760 		default:
761 			goto invalid;
762 		}
763 		ncm->ndp_sign = ncm->parser_opts->ndp_sign | ndp_hdr_crc;
764 		value = 0;
765 		break;
766 	}
767 
768 	/* and disabled in ncm descriptor: */
769 	/* case USB_CDC_GET_NET_ADDRESS: */
770 	/* case USB_CDC_SET_NET_ADDRESS: */
771 	/* case USB_CDC_GET_MAX_DATAGRAM_SIZE: */
772 	/* case USB_CDC_SET_MAX_DATAGRAM_SIZE: */
773 
774 	default:
775 invalid:
776 		DBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
777 			ctrl->bRequestType, ctrl->bRequest,
778 			w_value, w_index, w_length);
779 	}
780 
781 	/* respond with data transfer or status phase? */
782 	if (value >= 0) {
783 		DBG(cdev, "ncm req%02x.%02x v%04x i%04x l%d\n",
784 			ctrl->bRequestType, ctrl->bRequest,
785 			w_value, w_index, w_length);
786 		req->zero = 0;
787 		req->length = value;
788 		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
789 		if (value < 0)
790 			ERROR(cdev, "ncm req %02x.%02x response err %d\n",
791 					ctrl->bRequestType, ctrl->bRequest,
792 					value);
793 	}
794 
795 	/* device either stalls (value < 0) or reports success */
796 	return value;
797 }
798 
799 
ncm_set_alt(struct usb_function * f,unsigned intf,unsigned alt)800 static int ncm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
801 {
802 	struct f_ncm		*ncm = func_to_ncm(f);
803 	struct usb_composite_dev *cdev = f->config->cdev;
804 
805 	/* Control interface has only altsetting 0 */
806 	if (intf == ncm->ctrl_id) {
807 		if (alt != 0)
808 			goto fail;
809 
810 		DBG(cdev, "reset ncm control %d\n", intf);
811 		usb_ep_disable(ncm->notify);
812 
813 		if (!(ncm->notify->desc)) {
814 			DBG(cdev, "init ncm ctrl %d\n", intf);
815 			if (config_ep_by_speed(cdev->gadget, f, ncm->notify))
816 				goto fail;
817 		}
818 		usb_ep_enable(ncm->notify);
819 
820 	/* Data interface has two altsettings, 0 and 1 */
821 	} else if (intf == ncm->data_id) {
822 		if (alt > 1)
823 			goto fail;
824 
825 		if (ncm->port.in_ep->enabled) {
826 			DBG(cdev, "reset ncm\n");
827 			ncm->timer_stopping = true;
828 			ncm->netdev = NULL;
829 			gether_disconnect(&ncm->port);
830 			ncm_reset_values(ncm);
831 		}
832 
833 		/*
834 		 * CDC Network only sends data in non-default altsettings.
835 		 * Changing altsettings resets filters, statistics, etc.
836 		 */
837 		if (alt == 1) {
838 			struct net_device	*net;
839 
840 			if (!ncm->port.in_ep->desc ||
841 			    !ncm->port.out_ep->desc) {
842 				DBG(cdev, "init ncm\n");
843 				if (config_ep_by_speed(cdev->gadget, f,
844 						       ncm->port.in_ep) ||
845 				    config_ep_by_speed(cdev->gadget, f,
846 						       ncm->port.out_ep)) {
847 					ncm->port.in_ep->desc = NULL;
848 					ncm->port.out_ep->desc = NULL;
849 					goto fail;
850 				}
851 			}
852 
853 			/* TODO */
854 			/* Enable zlps by default for NCM conformance;
855 			 * override for musb_hdrc (avoids txdma ovhead)
856 			 */
857 			ncm->port.is_zlp_ok =
858 				gadget_is_zlp_supported(cdev->gadget);
859 			ncm->port.cdc_filter = DEFAULT_FILTER;
860 			DBG(cdev, "activate ncm\n");
861 			net = gether_connect(&ncm->port);
862 			if (IS_ERR(net))
863 				return PTR_ERR(net);
864 			ncm->netdev = net;
865 			ncm->timer_stopping = false;
866 		}
867 
868 		spin_lock(&ncm->lock);
869 		ncm_notify(ncm);
870 		spin_unlock(&ncm->lock);
871 	} else
872 		goto fail;
873 
874 	return 0;
875 fail:
876 	return -EINVAL;
877 }
878 
879 /*
880  * Because the data interface supports multiple altsettings,
881  * this NCM function *MUST* implement a get_alt() method.
882  */
ncm_get_alt(struct usb_function * f,unsigned intf)883 static int ncm_get_alt(struct usb_function *f, unsigned intf)
884 {
885 	struct f_ncm		*ncm = func_to_ncm(f);
886 
887 	if (intf == ncm->ctrl_id)
888 		return 0;
889 	return ncm->port.in_ep->enabled ? 1 : 0;
890 }
891 
package_for_tx(struct f_ncm * ncm)892 static struct sk_buff *package_for_tx(struct f_ncm *ncm)
893 {
894 	__le16		*ntb_iter;
895 	struct sk_buff	*skb2 = NULL;
896 	unsigned	ndp_pad;
897 	unsigned	ndp_index;
898 	unsigned	new_len;
899 
900 	const struct ndp_parser_opts *opts = ncm->parser_opts;
901 	const int ndp_align = le16_to_cpu(ntb_parameters.wNdpInAlignment);
902 	const int dgram_idx_len = 2 * 2 * opts->dgram_item_len;
903 
904 	/* Stop the timer */
905 	hrtimer_try_to_cancel(&ncm->task_timer);
906 
907 	ndp_pad = ALIGN(ncm->skb_tx_data->len, ndp_align) -
908 			ncm->skb_tx_data->len;
909 	ndp_index = ncm->skb_tx_data->len + ndp_pad;
910 	new_len = ndp_index + dgram_idx_len + ncm->skb_tx_ndp->len;
911 
912 	/* Set the final BlockLength and wNdpIndex */
913 	ntb_iter = (void *) ncm->skb_tx_data->data;
914 	/* Increment pointer to BlockLength */
915 	ntb_iter += 2 + 1 + 1;
916 	put_ncm(&ntb_iter, opts->block_length, new_len);
917 	put_ncm(&ntb_iter, opts->ndp_index, ndp_index);
918 
919 	/* Set the final NDP wLength */
920 	new_len = opts->ndp_size +
921 			(ncm->ndp_dgram_count * dgram_idx_len);
922 	ncm->ndp_dgram_count = 0;
923 	/* Increment from start to wLength */
924 	ntb_iter = (void *) ncm->skb_tx_ndp->data;
925 	ntb_iter += 2;
926 	put_unaligned_le16(new_len, ntb_iter);
927 
928 	/* Merge the skbs */
929 	swap(skb2, ncm->skb_tx_data);
930 	if (ncm->skb_tx_data) {
931 		dev_kfree_skb_any(ncm->skb_tx_data);
932 		ncm->skb_tx_data = NULL;
933 	}
934 
935 	/* Insert NDP alignment. */
936 	ntb_iter = (void *) skb_put(skb2, ndp_pad);
937 	memset(ntb_iter, 0, ndp_pad);
938 
939 	/* Copy NTB across. */
940 	ntb_iter = (void *) skb_put(skb2, ncm->skb_tx_ndp->len);
941 	memcpy(ntb_iter, ncm->skb_tx_ndp->data, ncm->skb_tx_ndp->len);
942 	dev_kfree_skb_any(ncm->skb_tx_ndp);
943 	ncm->skb_tx_ndp = NULL;
944 
945 	/* Insert zero'd datagram. */
946 	ntb_iter = (void *) skb_put(skb2, dgram_idx_len);
947 	memset(ntb_iter, 0, dgram_idx_len);
948 
949 	return skb2;
950 }
951 
ncm_wrap_ntb(struct gether * port,struct sk_buff * skb)952 static struct sk_buff *ncm_wrap_ntb(struct gether *port,
953 				    struct sk_buff *skb)
954 {
955 	struct f_ncm	*ncm = func_to_ncm(&port->func);
956 	struct sk_buff	*skb2 = NULL;
957 	int		ncb_len = 0;
958 	__le16		*ntb_data;
959 	__le16		*ntb_ndp;
960 	int		dgram_pad;
961 
962 	unsigned	max_size = ncm->port.fixed_in_len;
963 	const struct ndp_parser_opts *opts = ncm->parser_opts;
964 	const int ndp_align = le16_to_cpu(ntb_parameters.wNdpInAlignment);
965 	const int div = le16_to_cpu(ntb_parameters.wNdpInDivisor);
966 	const int rem = le16_to_cpu(ntb_parameters.wNdpInPayloadRemainder);
967 	const int dgram_idx_len = 2 * 2 * opts->dgram_item_len;
968 
969 	if (!skb && !ncm->skb_tx_data)
970 		return NULL;
971 
972 	if (skb) {
973 		/* Add the CRC if required up front */
974 		if (ncm->is_crc) {
975 			uint32_t	crc;
976 			__le16		*crc_pos;
977 
978 			crc = ~crc32_le(~0,
979 					skb->data,
980 					skb->len);
981 			crc_pos = (void *) skb_put(skb, sizeof(uint32_t));
982 			put_unaligned_le32(crc, crc_pos);
983 		}
984 
985 		/* If the new skb is too big for the current NCM NTB then
986 		 * set the current stored skb to be sent now and clear it
987 		 * ready for new data.
988 		 * NOTE: Assume maximum align for speed of calculation.
989 		 */
990 		if (ncm->skb_tx_data
991 		    && (ncm->ndp_dgram_count >= TX_MAX_NUM_DPE
992 		    || (ncm->skb_tx_data->len +
993 		    div + rem + skb->len +
994 		    ncm->skb_tx_ndp->len + ndp_align + (2 * dgram_idx_len))
995 		    > max_size)) {
996 			skb2 = package_for_tx(ncm);
997 			if (!skb2)
998 				goto err;
999 		}
1000 
1001 		if (!ncm->skb_tx_data) {
1002 			ncb_len = opts->nth_size;
1003 			dgram_pad = ALIGN(ncb_len, div) + rem - ncb_len;
1004 			ncb_len += dgram_pad;
1005 
1006 			/* Create a new skb for the NTH and datagrams. */
1007 			ncm->skb_tx_data = alloc_skb(max_size, GFP_ATOMIC);
1008 			if (!ncm->skb_tx_data)
1009 				goto err;
1010 
1011 			ntb_data = (void *) skb_put(ncm->skb_tx_data, ncb_len);
1012 			memset(ntb_data, 0, ncb_len);
1013 			/* dwSignature */
1014 			put_unaligned_le32(opts->nth_sign, ntb_data);
1015 			ntb_data += 2;
1016 			/* wHeaderLength */
1017 			put_unaligned_le16(opts->nth_size, ntb_data++);
1018 
1019 			/* Allocate an skb for storing the NDP,
1020 			 * TX_MAX_NUM_DPE should easily suffice for a
1021 			 * 16k packet.
1022 			 */
1023 			ncm->skb_tx_ndp = alloc_skb((int)(opts->ndp_size
1024 						    + opts->dpe_size
1025 						    * TX_MAX_NUM_DPE),
1026 						    GFP_ATOMIC);
1027 			if (!ncm->skb_tx_ndp)
1028 				goto err;
1029 			ntb_ndp = (void *) skb_put(ncm->skb_tx_ndp,
1030 						    opts->ndp_size);
1031 			memset(ntb_ndp, 0, ncb_len);
1032 			/* dwSignature */
1033 			put_unaligned_le32(ncm->ndp_sign, ntb_ndp);
1034 			ntb_ndp += 2;
1035 
1036 			/* There is always a zeroed entry */
1037 			ncm->ndp_dgram_count = 1;
1038 
1039 			/* Note: we skip opts->next_ndp_index */
1040 		}
1041 
1042 		/* Delay the timer. */
1043 		hrtimer_start(&ncm->task_timer,
1044 			      ktime_set(0, TX_TIMEOUT_NSECS),
1045 			      HRTIMER_MODE_REL);
1046 
1047 		/* Add the datagram position entries */
1048 		ntb_ndp = (void *) skb_put(ncm->skb_tx_ndp, dgram_idx_len);
1049 		memset(ntb_ndp, 0, dgram_idx_len);
1050 
1051 		ncb_len = ncm->skb_tx_data->len;
1052 		dgram_pad = ALIGN(ncb_len, div) + rem - ncb_len;
1053 		ncb_len += dgram_pad;
1054 
1055 		/* (d)wDatagramIndex */
1056 		put_ncm(&ntb_ndp, opts->dgram_item_len, ncb_len);
1057 		/* (d)wDatagramLength */
1058 		put_ncm(&ntb_ndp, opts->dgram_item_len, skb->len);
1059 		ncm->ndp_dgram_count++;
1060 
1061 		/* Add the new data to the skb */
1062 		ntb_data = (void *) skb_put(ncm->skb_tx_data, dgram_pad);
1063 		memset(ntb_data, 0, dgram_pad);
1064 		ntb_data = (void *) skb_put(ncm->skb_tx_data, skb->len);
1065 		memcpy(ntb_data, skb->data, skb->len);
1066 		dev_kfree_skb_any(skb);
1067 		skb = NULL;
1068 
1069 	} else if (ncm->skb_tx_data && ncm->timer_force_tx) {
1070 		/* If the tx was requested because of a timeout then send */
1071 		skb2 = package_for_tx(ncm);
1072 		if (!skb2)
1073 			goto err;
1074 	}
1075 
1076 	return skb2;
1077 
1078 err:
1079 	ncm->netdev->stats.tx_dropped++;
1080 
1081 	if (skb)
1082 		dev_kfree_skb_any(skb);
1083 	if (ncm->skb_tx_data)
1084 		dev_kfree_skb_any(ncm->skb_tx_data);
1085 	if (ncm->skb_tx_ndp)
1086 		dev_kfree_skb_any(ncm->skb_tx_ndp);
1087 
1088 	return NULL;
1089 }
1090 
1091 /*
1092  * This transmits the NTB if there are frames waiting.
1093  */
ncm_tx_tasklet(unsigned long data)1094 static void ncm_tx_tasklet(unsigned long data)
1095 {
1096 	struct f_ncm	*ncm = (void *)data;
1097 
1098 	if (ncm->timer_stopping)
1099 		return;
1100 
1101 	/* Only send if data is available. */
1102 	if (ncm->skb_tx_data) {
1103 		ncm->timer_force_tx = true;
1104 
1105 		/* XXX This allowance of a NULL skb argument to ndo_start_xmit
1106 		 * XXX is not sane.  The gadget layer should be redesigned so
1107 		 * XXX that the dev->wrap() invocations to build SKBs is transparent
1108 		 * XXX and performed in some way outside of the ndo_start_xmit
1109 		 * XXX interface.
1110 		 */
1111 		ncm->netdev->netdev_ops->ndo_start_xmit(NULL, ncm->netdev);
1112 
1113 		ncm->timer_force_tx = false;
1114 	}
1115 }
1116 
1117 /*
1118  * The transmit should only be run if no skb data has been sent
1119  * for a certain duration.
1120  */
ncm_tx_timeout(struct hrtimer * data)1121 static enum hrtimer_restart ncm_tx_timeout(struct hrtimer *data)
1122 {
1123 	struct f_ncm *ncm = container_of(data, struct f_ncm, task_timer);
1124 	tasklet_schedule(&ncm->tx_tasklet);
1125 	return HRTIMER_NORESTART;
1126 }
1127 
ncm_unwrap_ntb(struct gether * port,struct sk_buff * skb,struct sk_buff_head * list)1128 static int ncm_unwrap_ntb(struct gether *port,
1129 			  struct sk_buff *skb,
1130 			  struct sk_buff_head *list)
1131 {
1132 	struct f_ncm	*ncm = func_to_ncm(&port->func);
1133 	__le16		*tmp = (void *) skb->data;
1134 	unsigned	index, index2;
1135 	int		ndp_index;
1136 	unsigned	dg_len, dg_len2;
1137 	unsigned	ndp_len;
1138 	struct sk_buff	*skb2;
1139 	int		ret = -EINVAL;
1140 	unsigned	max_size = le32_to_cpu(ntb_parameters.dwNtbOutMaxSize);
1141 	const struct ndp_parser_opts *opts = ncm->parser_opts;
1142 	unsigned	crc_len = ncm->is_crc ? sizeof(uint32_t) : 0;
1143 	int		dgram_counter;
1144 
1145 	/* dwSignature */
1146 	if (get_unaligned_le32(tmp) != opts->nth_sign) {
1147 		INFO(port->func.config->cdev, "Wrong NTH SIGN, skblen %d\n",
1148 			skb->len);
1149 		print_hex_dump(KERN_INFO, "HEAD:", DUMP_PREFIX_ADDRESS, 32, 1,
1150 			       skb->data, 32, false);
1151 
1152 		goto err;
1153 	}
1154 	tmp += 2;
1155 	/* wHeaderLength */
1156 	if (get_unaligned_le16(tmp++) != opts->nth_size) {
1157 		INFO(port->func.config->cdev, "Wrong NTB headersize\n");
1158 		goto err;
1159 	}
1160 	tmp++; /* skip wSequence */
1161 
1162 	/* (d)wBlockLength */
1163 	if (get_ncm(&tmp, opts->block_length) > max_size) {
1164 		INFO(port->func.config->cdev, "OUT size exceeded\n");
1165 		goto err;
1166 	}
1167 
1168 	ndp_index = get_ncm(&tmp, opts->ndp_index);
1169 
1170 	/* Run through all the NDP's in the NTB */
1171 	do {
1172 		/* NCM 3.2 */
1173 		if (((ndp_index % 4) != 0) &&
1174 				(ndp_index < opts->nth_size)) {
1175 			INFO(port->func.config->cdev, "Bad index: %#X\n",
1176 			     ndp_index);
1177 			goto err;
1178 		}
1179 
1180 		/* walk through NDP */
1181 		tmp = (void *)(skb->data + ndp_index);
1182 		if (get_unaligned_le32(tmp) != ncm->ndp_sign) {
1183 			INFO(port->func.config->cdev, "Wrong NDP SIGN\n");
1184 			goto err;
1185 		}
1186 		tmp += 2;
1187 
1188 		ndp_len = get_unaligned_le16(tmp++);
1189 		/*
1190 		 * NCM 3.3.1
1191 		 * entry is 2 items
1192 		 * item size is 16/32 bits, opts->dgram_item_len * 2 bytes
1193 		 * minimal: struct usb_cdc_ncm_ndpX + normal entry + zero entry
1194 		 * Each entry is a dgram index and a dgram length.
1195 		 */
1196 		if ((ndp_len < opts->ndp_size
1197 				+ 2 * 2 * (opts->dgram_item_len * 2))
1198 				|| (ndp_len % opts->ndplen_align != 0)) {
1199 			INFO(port->func.config->cdev, "Bad NDP length: %#X\n",
1200 			     ndp_len);
1201 			goto err;
1202 		}
1203 		tmp += opts->reserved1;
1204 		/* Check for another NDP (d)wNextNdpIndex */
1205 		ndp_index = get_ncm(&tmp, opts->next_ndp_index);
1206 		tmp += opts->reserved2;
1207 
1208 		ndp_len -= opts->ndp_size;
1209 		index2 = get_ncm(&tmp, opts->dgram_item_len);
1210 		dg_len2 = get_ncm(&tmp, opts->dgram_item_len);
1211 		dgram_counter = 0;
1212 
1213 		do {
1214 			index = index2;
1215 			dg_len = dg_len2;
1216 			if (dg_len < 14 + crc_len) { /* ethernet hdr + crc */
1217 				INFO(port->func.config->cdev,
1218 				     "Bad dgram length: %#X\n", dg_len);
1219 				goto err;
1220 			}
1221 			if (ncm->is_crc) {
1222 				uint32_t crc, crc2;
1223 
1224 				crc = get_unaligned_le32(skb->data +
1225 							 index + dg_len -
1226 							 crc_len);
1227 				crc2 = ~crc32_le(~0,
1228 						 skb->data + index,
1229 						 dg_len - crc_len);
1230 				if (crc != crc2) {
1231 					INFO(port->func.config->cdev,
1232 					     "Bad CRC\n");
1233 					goto err;
1234 				}
1235 			}
1236 
1237 			index2 = get_ncm(&tmp, opts->dgram_item_len);
1238 			dg_len2 = get_ncm(&tmp, opts->dgram_item_len);
1239 
1240 			/*
1241 			 * Copy the data into a new skb.
1242 			 * This ensures the truesize is correct
1243 			 */
1244 			skb2 = netdev_alloc_skb_ip_align(ncm->netdev,
1245 							 dg_len - crc_len);
1246 			if (skb2 == NULL)
1247 				goto err;
1248 			memcpy(skb_put(skb2, dg_len - crc_len),
1249 			       skb->data + index, dg_len - crc_len);
1250 
1251 			skb_queue_tail(list, skb2);
1252 
1253 			ndp_len -= 2 * (opts->dgram_item_len * 2);
1254 
1255 			dgram_counter++;
1256 
1257 			if (index2 == 0 || dg_len2 == 0)
1258 				break;
1259 		} while (ndp_len > 2 * (opts->dgram_item_len * 2));
1260 	} while (ndp_index);
1261 
1262 	dev_kfree_skb_any(skb);
1263 
1264 	VDBG(port->func.config->cdev,
1265 	     "Parsed NTB with %d frames\n", dgram_counter);
1266 	return 0;
1267 err:
1268 	skb_queue_purge(list);
1269 	dev_kfree_skb_any(skb);
1270 	return ret;
1271 }
1272 
ncm_disable(struct usb_function * f)1273 static void ncm_disable(struct usb_function *f)
1274 {
1275 	struct f_ncm		*ncm = func_to_ncm(f);
1276 	struct usb_composite_dev *cdev = f->config->cdev;
1277 
1278 	DBG(cdev, "ncm deactivated\n");
1279 
1280 	if (ncm->port.in_ep->enabled) {
1281 		ncm->timer_stopping = true;
1282 		ncm->netdev = NULL;
1283 		gether_disconnect(&ncm->port);
1284 	}
1285 
1286 	if (ncm->notify->enabled) {
1287 		usb_ep_disable(ncm->notify);
1288 		ncm->notify->desc = NULL;
1289 	}
1290 }
1291 
1292 /*-------------------------------------------------------------------------*/
1293 
1294 /*
1295  * Callbacks let us notify the host about connect/disconnect when the
1296  * net device is opened or closed.
1297  *
1298  * For testing, note that link states on this side include both opened
1299  * and closed variants of:
1300  *
1301  *   - disconnected/unconfigured
1302  *   - configured but inactive (data alt 0)
1303  *   - configured and active (data alt 1)
1304  *
1305  * Each needs to be tested with unplug, rmmod, SET_CONFIGURATION, and
1306  * SET_INTERFACE (altsetting).  Remember also that "configured" doesn't
1307  * imply the host is actually polling the notification endpoint, and
1308  * likewise that "active" doesn't imply it's actually using the data
1309  * endpoints for traffic.
1310  */
1311 
ncm_open(struct gether * geth)1312 static void ncm_open(struct gether *geth)
1313 {
1314 	struct f_ncm		*ncm = func_to_ncm(&geth->func);
1315 
1316 	DBG(ncm->port.func.config->cdev, "%s\n", __func__);
1317 
1318 	spin_lock(&ncm->lock);
1319 	ncm->is_open = true;
1320 	ncm_notify(ncm);
1321 	spin_unlock(&ncm->lock);
1322 }
1323 
ncm_close(struct gether * geth)1324 static void ncm_close(struct gether *geth)
1325 {
1326 	struct f_ncm		*ncm = func_to_ncm(&geth->func);
1327 
1328 	DBG(ncm->port.func.config->cdev, "%s\n", __func__);
1329 
1330 	spin_lock(&ncm->lock);
1331 	ncm->is_open = false;
1332 	ncm_notify(ncm);
1333 	spin_unlock(&ncm->lock);
1334 }
1335 
1336 /*-------------------------------------------------------------------------*/
1337 
1338 /* ethernet function driver setup/binding */
1339 
ncm_bind(struct usb_configuration * c,struct usb_function * f)1340 static int ncm_bind(struct usb_configuration *c, struct usb_function *f)
1341 {
1342 	struct usb_composite_dev *cdev = c->cdev;
1343 	struct f_ncm		*ncm = func_to_ncm(f);
1344 	struct usb_string	*us;
1345 	int			status;
1346 	struct usb_ep		*ep;
1347 	struct f_ncm_opts	*ncm_opts;
1348 
1349 	if (!can_support_ecm(cdev->gadget))
1350 		return -EINVAL;
1351 
1352 	ncm_opts = container_of(f->fi, struct f_ncm_opts, func_inst);
1353 	/*
1354 	 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
1355 	 * configurations are bound in sequence with list_for_each_entry,
1356 	 * in each configuration its functions are bound in sequence
1357 	 * with list_for_each_entry, so we assume no race condition
1358 	 * with regard to ncm_opts->bound access
1359 	 */
1360 	if (!ncm_opts->bound) {
1361 		mutex_lock(&ncm_opts->lock);
1362 		gether_set_gadget(ncm_opts->net, cdev->gadget);
1363 		status = gether_register_netdev(ncm_opts->net);
1364 		mutex_unlock(&ncm_opts->lock);
1365 		if (status)
1366 			return status;
1367 		ncm_opts->bound = true;
1368 	}
1369 	us = usb_gstrings_attach(cdev, ncm_strings,
1370 				 ARRAY_SIZE(ncm_string_defs));
1371 	if (IS_ERR(us))
1372 		return PTR_ERR(us);
1373 	ncm_control_intf.iInterface = us[STRING_CTRL_IDX].id;
1374 	ncm_data_nop_intf.iInterface = us[STRING_DATA_IDX].id;
1375 	ncm_data_intf.iInterface = us[STRING_DATA_IDX].id;
1376 	ecm_desc.iMACAddress = us[STRING_MAC_IDX].id;
1377 	ncm_iad_desc.iFunction = us[STRING_IAD_IDX].id;
1378 
1379 	/* allocate instance-specific interface IDs */
1380 	status = usb_interface_id(c, f);
1381 	if (status < 0)
1382 		goto fail;
1383 	ncm->ctrl_id = status;
1384 	ncm_iad_desc.bFirstInterface = status;
1385 
1386 	ncm_control_intf.bInterfaceNumber = status;
1387 	ncm_union_desc.bMasterInterface0 = status;
1388 
1389 	status = usb_interface_id(c, f);
1390 	if (status < 0)
1391 		goto fail;
1392 	ncm->data_id = status;
1393 
1394 	ncm_data_nop_intf.bInterfaceNumber = status;
1395 	ncm_data_intf.bInterfaceNumber = status;
1396 	ncm_union_desc.bSlaveInterface0 = status;
1397 
1398 	status = -ENODEV;
1399 
1400 	/* allocate instance-specific endpoints */
1401 	ep = usb_ep_autoconfig(cdev->gadget, &fs_ncm_in_desc);
1402 	if (!ep)
1403 		goto fail;
1404 	ncm->port.in_ep = ep;
1405 
1406 	ep = usb_ep_autoconfig(cdev->gadget, &fs_ncm_out_desc);
1407 	if (!ep)
1408 		goto fail;
1409 	ncm->port.out_ep = ep;
1410 
1411 	ep = usb_ep_autoconfig(cdev->gadget, &fs_ncm_notify_desc);
1412 	if (!ep)
1413 		goto fail;
1414 	ncm->notify = ep;
1415 
1416 	status = -ENOMEM;
1417 
1418 	/* allocate notification request and buffer */
1419 	ncm->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
1420 	if (!ncm->notify_req)
1421 		goto fail;
1422 	ncm->notify_req->buf = kmalloc(NCM_STATUS_BYTECOUNT, GFP_KERNEL);
1423 	if (!ncm->notify_req->buf)
1424 		goto fail;
1425 	ncm->notify_req->context = ncm;
1426 	ncm->notify_req->complete = ncm_notify_complete;
1427 
1428 	/*
1429 	 * support all relevant hardware speeds... we expect that when
1430 	 * hardware is dual speed, all bulk-capable endpoints work at
1431 	 * both speeds
1432 	 */
1433 	hs_ncm_in_desc.bEndpointAddress = fs_ncm_in_desc.bEndpointAddress;
1434 	hs_ncm_out_desc.bEndpointAddress = fs_ncm_out_desc.bEndpointAddress;
1435 	hs_ncm_notify_desc.bEndpointAddress =
1436 		fs_ncm_notify_desc.bEndpointAddress;
1437 
1438 	status = usb_assign_descriptors(f, ncm_fs_function, ncm_hs_function,
1439 			NULL);
1440 	if (status)
1441 		goto fail;
1442 
1443 	/*
1444 	 * NOTE:  all that is done without knowing or caring about
1445 	 * the network link ... which is unavailable to this code
1446 	 * until we're activated via set_alt().
1447 	 */
1448 
1449 	ncm->port.open = ncm_open;
1450 	ncm->port.close = ncm_close;
1451 
1452 	tasklet_init(&ncm->tx_tasklet, ncm_tx_tasklet, (unsigned long) ncm);
1453 	hrtimer_init(&ncm->task_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1454 	ncm->task_timer.function = ncm_tx_timeout;
1455 
1456 	DBG(cdev, "CDC Network: %s speed IN/%s OUT/%s NOTIFY/%s\n",
1457 			gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
1458 			ncm->port.in_ep->name, ncm->port.out_ep->name,
1459 			ncm->notify->name);
1460 	return 0;
1461 
1462 fail:
1463 	if (ncm->notify_req) {
1464 		kfree(ncm->notify_req->buf);
1465 		usb_ep_free_request(ncm->notify, ncm->notify_req);
1466 	}
1467 
1468 	ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
1469 
1470 	return status;
1471 }
1472 
to_f_ncm_opts(struct config_item * item)1473 static inline struct f_ncm_opts *to_f_ncm_opts(struct config_item *item)
1474 {
1475 	return container_of(to_config_group(item), struct f_ncm_opts,
1476 			    func_inst.group);
1477 }
1478 
1479 /* f_ncm_item_ops */
1480 USB_ETHERNET_CONFIGFS_ITEM(ncm);
1481 
1482 /* f_ncm_opts_dev_addr */
1483 USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(ncm);
1484 
1485 /* f_ncm_opts_host_addr */
1486 USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(ncm);
1487 
1488 /* f_ncm_opts_qmult */
1489 USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(ncm);
1490 
1491 /* f_ncm_opts_ifname */
1492 USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(ncm);
1493 
1494 static struct configfs_attribute *ncm_attrs[] = {
1495 	&ncm_opts_attr_dev_addr,
1496 	&ncm_opts_attr_host_addr,
1497 	&ncm_opts_attr_qmult,
1498 	&ncm_opts_attr_ifname,
1499 	NULL,
1500 };
1501 
1502 static struct config_item_type ncm_func_type = {
1503 	.ct_item_ops	= &ncm_item_ops,
1504 	.ct_attrs	= ncm_attrs,
1505 	.ct_owner	= THIS_MODULE,
1506 };
1507 
ncm_free_inst(struct usb_function_instance * f)1508 static void ncm_free_inst(struct usb_function_instance *f)
1509 {
1510 	struct f_ncm_opts *opts;
1511 
1512 	opts = container_of(f, struct f_ncm_opts, func_inst);
1513 	if (opts->bound)
1514 		gether_cleanup(netdev_priv(opts->net));
1515 	else
1516 		free_netdev(opts->net);
1517 	kfree(opts);
1518 }
1519 
ncm_alloc_inst(void)1520 static struct usb_function_instance *ncm_alloc_inst(void)
1521 {
1522 	struct f_ncm_opts *opts;
1523 
1524 	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1525 	if (!opts)
1526 		return ERR_PTR(-ENOMEM);
1527 	mutex_init(&opts->lock);
1528 	opts->func_inst.free_func_inst = ncm_free_inst;
1529 	opts->net = gether_setup_default();
1530 	if (IS_ERR(opts->net)) {
1531 		struct net_device *net = opts->net;
1532 		kfree(opts);
1533 		return ERR_CAST(net);
1534 	}
1535 
1536 	config_group_init_type_name(&opts->func_inst.group, "", &ncm_func_type);
1537 
1538 	return &opts->func_inst;
1539 }
1540 
ncm_free(struct usb_function * f)1541 static void ncm_free(struct usb_function *f)
1542 {
1543 	struct f_ncm *ncm;
1544 	struct f_ncm_opts *opts;
1545 
1546 	ncm = func_to_ncm(f);
1547 	opts = container_of(f->fi, struct f_ncm_opts, func_inst);
1548 	kfree(ncm);
1549 	mutex_lock(&opts->lock);
1550 	opts->refcnt--;
1551 	mutex_unlock(&opts->lock);
1552 }
1553 
ncm_unbind(struct usb_configuration * c,struct usb_function * f)1554 static void ncm_unbind(struct usb_configuration *c, struct usb_function *f)
1555 {
1556 	struct f_ncm *ncm = func_to_ncm(f);
1557 
1558 	DBG(c->cdev, "ncm unbind\n");
1559 
1560 	hrtimer_cancel(&ncm->task_timer);
1561 	tasklet_kill(&ncm->tx_tasklet);
1562 
1563 	ncm_string_defs[0].id = 0;
1564 	usb_free_all_descriptors(f);
1565 
1566 	if (atomic_read(&ncm->notify_count)) {
1567 		usb_ep_dequeue(ncm->notify, ncm->notify_req);
1568 		atomic_set(&ncm->notify_count, 0);
1569 	}
1570 
1571 	kfree(ncm->notify_req->buf);
1572 	usb_ep_free_request(ncm->notify, ncm->notify_req);
1573 }
1574 
ncm_alloc(struct usb_function_instance * fi)1575 static struct usb_function *ncm_alloc(struct usb_function_instance *fi)
1576 {
1577 	struct f_ncm		*ncm;
1578 	struct f_ncm_opts	*opts;
1579 	int status;
1580 
1581 	/* allocate and initialize one new instance */
1582 	ncm = kzalloc(sizeof(*ncm), GFP_KERNEL);
1583 	if (!ncm)
1584 		return ERR_PTR(-ENOMEM);
1585 
1586 	opts = container_of(fi, struct f_ncm_opts, func_inst);
1587 	mutex_lock(&opts->lock);
1588 	opts->refcnt++;
1589 
1590 	/* export host's Ethernet address in CDC format */
1591 	status = gether_get_host_addr_cdc(opts->net, ncm->ethaddr,
1592 				      sizeof(ncm->ethaddr));
1593 	if (status < 12) { /* strlen("01234567890a") */
1594 		kfree(ncm);
1595 		mutex_unlock(&opts->lock);
1596 		return ERR_PTR(-EINVAL);
1597 	}
1598 	ncm_string_defs[STRING_MAC_IDX].s = ncm->ethaddr;
1599 
1600 	spin_lock_init(&ncm->lock);
1601 	ncm_reset_values(ncm);
1602 	ncm->port.ioport = netdev_priv(opts->net);
1603 	mutex_unlock(&opts->lock);
1604 	ncm->port.is_fixed = true;
1605 	ncm->port.supports_multi_frame = true;
1606 
1607 	ncm->port.func.name = "cdc_network";
1608 	/* descriptors are per-instance copies */
1609 	ncm->port.func.bind = ncm_bind;
1610 	ncm->port.func.unbind = ncm_unbind;
1611 	ncm->port.func.set_alt = ncm_set_alt;
1612 	ncm->port.func.get_alt = ncm_get_alt;
1613 	ncm->port.func.setup = ncm_setup;
1614 	ncm->port.func.disable = ncm_disable;
1615 	ncm->port.func.free_func = ncm_free;
1616 
1617 	ncm->port.wrap = ncm_wrap_ntb;
1618 	ncm->port.unwrap = ncm_unwrap_ntb;
1619 
1620 	return &ncm->port.func;
1621 }
1622 
1623 DECLARE_USB_FUNCTION_INIT(ncm, ncm_alloc_inst, ncm_alloc);
1624 MODULE_LICENSE("GPL");
1625 MODULE_AUTHOR("Yauheni Kaliuta");
1626