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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/interrupt.h>
20 #include <linux/module.h>
21 #include <linux/device.h>
22 #include <linux/etherdevice.h>
23 #include <linux/crc32.h>
24 
25 #include <linux/usb/cdc.h>
26 
27 #include "u_ether.h"
28 #include "u_ether_configfs.h"
29 #include "u_ncm.h"
30 
31 /*
32  * This function is a "CDC Network Control Model" (CDC NCM) Ethernet link.
33  * NCM is intended to be used with high-speed network attachments.
34  *
35  * Note that NCM requires the use of "alternate settings" for its data
36  * interface.  This means that the set_alt() method has real work to do,
37  * and also means that a get_alt() method is required.
38  */
39 
40 /* to trigger crc/non-crc ndp signature */
41 
42 #define NCM_NDP_HDR_CRC_MASK	0x01000000
43 #define NCM_NDP_HDR_CRC		0x01000000
44 #define NCM_NDP_HDR_NOCRC	0x00000000
45 
46 enum ncm_notify_state {
47 	NCM_NOTIFY_NONE,		/* don't notify */
48 	NCM_NOTIFY_CONNECT,		/* issue CONNECT next */
49 	NCM_NOTIFY_SPEED,		/* issue SPEED_CHANGE next */
50 };
51 
52 struct f_ncm {
53 	struct gether			port;
54 	u8				ctrl_id, data_id;
55 
56 	char				ethaddr[14];
57 
58 	struct usb_ep			*notify;
59 	struct usb_request		*notify_req;
60 	u8				notify_state;
61 	atomic_t			notify_count;
62 	bool				is_open;
63 
64 	const struct ndp_parser_opts	*parser_opts;
65 	bool				is_crc;
66 	u32				ndp_sign;
67 
68 	/*
69 	 * for notification, it is accessed from both
70 	 * callback and ethernet open/close
71 	 */
72 	spinlock_t			lock;
73 
74 	struct net_device		*netdev;
75 
76 	/* For multi-frame NDP TX */
77 	struct sk_buff			*skb_tx_data;
78 	struct sk_buff			*skb_tx_ndp;
79 	u16				ndp_dgram_count;
80 	bool				timer_force_tx;
81 	struct tasklet_struct		tx_tasklet;
82 	struct hrtimer			task_timer;
83 
84 	bool				timer_stopping;
85 };
86 
func_to_ncm(struct usb_function * f)87 static inline struct f_ncm *func_to_ncm(struct usb_function *f)
88 {
89 	return container_of(f, struct f_ncm, port.func);
90 }
91 
92 /* peak (theoretical) bulk transfer rate in bits-per-second */
ncm_bitrate(struct usb_gadget * g)93 static inline unsigned ncm_bitrate(struct usb_gadget *g)
94 {
95 	if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER)
96 		return 13 * 1024 * 8 * 1000 * 8;
97 	else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH)
98 		return 13 * 512 * 8 * 1000 * 8;
99 	else
100 		return 19 *  64 * 1 * 1000 * 8;
101 }
102 
103 /*-------------------------------------------------------------------------*/
104 
105 /*
106  * We cannot group frames so use just the minimal size which ok to put
107  * one max-size ethernet frame.
108  * If the host can group frames, allow it to do that, 16K is selected,
109  * because it's used by default by the current linux host driver
110  */
111 #define NTB_DEFAULT_IN_SIZE	16384
112 #define NTB_OUT_SIZE		16384
113 
114 /* Allocation for storing the NDP, 32 should suffice for a
115  * 16k packet. This allows a maximum of 32 * 507 Byte packets to
116  * be transmitted in a single 16kB skb, though when sending full size
117  * packets this limit will be plenty.
118  * Smaller packets are not likely to be trying to maximize the
119  * throughput and will be mstly sending smaller infrequent frames.
120  */
121 #define TX_MAX_NUM_DPE		32
122 
123 /* Delay for the transmit to wait before sending an unfilled NTB frame. */
124 #define TX_TIMEOUT_NSECS	300000
125 
126 #define FORMATS_SUPPORTED	(USB_CDC_NCM_NTB16_SUPPORTED |	\
127 				 USB_CDC_NCM_NTB32_SUPPORTED)
128 
129 static struct usb_cdc_ncm_ntb_parameters ntb_parameters = {
130 	.wLength = cpu_to_le16(sizeof(ntb_parameters)),
131 	.bmNtbFormatsSupported = cpu_to_le16(FORMATS_SUPPORTED),
132 	.dwNtbInMaxSize = cpu_to_le32(NTB_DEFAULT_IN_SIZE),
133 	.wNdpInDivisor = cpu_to_le16(4),
134 	.wNdpInPayloadRemainder = cpu_to_le16(0),
135 	.wNdpInAlignment = cpu_to_le16(4),
136 
137 	.dwNtbOutMaxSize = cpu_to_le32(NTB_OUT_SIZE),
138 	.wNdpOutDivisor = cpu_to_le16(4),
139 	.wNdpOutPayloadRemainder = cpu_to_le16(0),
140 	.wNdpOutAlignment = cpu_to_le16(4),
141 };
142 
143 /*
144  * Use wMaxPacketSize big enough to fit CDC_NOTIFY_SPEED_CHANGE in one
145  * packet, to simplify cancellation; and a big transfer interval, to
146  * waste less bandwidth.
147  */
148 
149 #define NCM_STATUS_INTERVAL_MS		32
150 #define NCM_STATUS_BYTECOUNT		16	/* 8 byte header + data */
151 
152 static struct usb_interface_assoc_descriptor ncm_iad_desc = {
153 	.bLength =		sizeof ncm_iad_desc,
154 	.bDescriptorType =	USB_DT_INTERFACE_ASSOCIATION,
155 
156 	/* .bFirstInterface =	DYNAMIC, */
157 	.bInterfaceCount =	2,	/* control + data */
158 	.bFunctionClass =	USB_CLASS_COMM,
159 	.bFunctionSubClass =	USB_CDC_SUBCLASS_NCM,
160 	.bFunctionProtocol =	USB_CDC_PROTO_NONE,
161 	/* .iFunction =		DYNAMIC */
162 };
163 
164 /* interface descriptor: */
165 
166 static struct usb_interface_descriptor ncm_control_intf = {
167 	.bLength =		sizeof ncm_control_intf,
168 	.bDescriptorType =	USB_DT_INTERFACE,
169 
170 	/* .bInterfaceNumber = DYNAMIC */
171 	.bNumEndpoints =	1,
172 	.bInterfaceClass =	USB_CLASS_COMM,
173 	.bInterfaceSubClass =	USB_CDC_SUBCLASS_NCM,
174 	.bInterfaceProtocol =	USB_CDC_PROTO_NONE,
175 	/* .iInterface = DYNAMIC */
176 };
177 
178 static struct usb_cdc_header_desc ncm_header_desc = {
179 	.bLength =		sizeof ncm_header_desc,
180 	.bDescriptorType =	USB_DT_CS_INTERFACE,
181 	.bDescriptorSubType =	USB_CDC_HEADER_TYPE,
182 
183 	.bcdCDC =		cpu_to_le16(0x0110),
184 };
185 
186 static struct usb_cdc_union_desc ncm_union_desc = {
187 	.bLength =		sizeof(ncm_union_desc),
188 	.bDescriptorType =	USB_DT_CS_INTERFACE,
189 	.bDescriptorSubType =	USB_CDC_UNION_TYPE,
190 	/* .bMasterInterface0 =	DYNAMIC */
191 	/* .bSlaveInterface0 =	DYNAMIC */
192 };
193 
194 static struct usb_cdc_ether_desc ecm_desc = {
195 	.bLength =		sizeof ecm_desc,
196 	.bDescriptorType =	USB_DT_CS_INTERFACE,
197 	.bDescriptorSubType =	USB_CDC_ETHERNET_TYPE,
198 
199 	/* this descriptor actually adds value, surprise! */
200 	/* .iMACAddress = DYNAMIC */
201 	.bmEthernetStatistics =	cpu_to_le32(0), /* no statistics */
202 	.wMaxSegmentSize =	cpu_to_le16(ETH_FRAME_LEN),
203 	.wNumberMCFilters =	cpu_to_le16(0),
204 	.bNumberPowerFilters =	0,
205 };
206 
207 #define NCAPS	(USB_CDC_NCM_NCAP_ETH_FILTER | USB_CDC_NCM_NCAP_CRC_MODE)
208 
209 static struct usb_cdc_ncm_desc ncm_desc = {
210 	.bLength =		sizeof ncm_desc,
211 	.bDescriptorType =	USB_DT_CS_INTERFACE,
212 	.bDescriptorSubType =	USB_CDC_NCM_TYPE,
213 
214 	.bcdNcmVersion =	cpu_to_le16(0x0100),
215 	/* can process SetEthernetPacketFilter */
216 	.bmNetworkCapabilities = NCAPS,
217 };
218 
219 /* the default data interface has no endpoints ... */
220 
221 static struct usb_interface_descriptor ncm_data_nop_intf = {
222 	.bLength =		sizeof ncm_data_nop_intf,
223 	.bDescriptorType =	USB_DT_INTERFACE,
224 
225 	.bInterfaceNumber =	1,
226 	.bAlternateSetting =	0,
227 	.bNumEndpoints =	0,
228 	.bInterfaceClass =	USB_CLASS_CDC_DATA,
229 	.bInterfaceSubClass =	0,
230 	.bInterfaceProtocol =	USB_CDC_NCM_PROTO_NTB,
231 	/* .iInterface = DYNAMIC */
232 };
233 
234 /* ... but the "real" data interface has two bulk endpoints */
235 
236 static struct usb_interface_descriptor ncm_data_intf = {
237 	.bLength =		sizeof ncm_data_intf,
238 	.bDescriptorType =	USB_DT_INTERFACE,
239 
240 	.bInterfaceNumber =	1,
241 	.bAlternateSetting =	1,
242 	.bNumEndpoints =	2,
243 	.bInterfaceClass =	USB_CLASS_CDC_DATA,
244 	.bInterfaceSubClass =	0,
245 	.bInterfaceProtocol =	USB_CDC_NCM_PROTO_NTB,
246 	/* .iInterface = DYNAMIC */
247 };
248 
249 /* full speed support: */
250 
251 static struct usb_endpoint_descriptor fs_ncm_notify_desc = {
252 	.bLength =		USB_DT_ENDPOINT_SIZE,
253 	.bDescriptorType =	USB_DT_ENDPOINT,
254 
255 	.bEndpointAddress =	USB_DIR_IN,
256 	.bmAttributes =		USB_ENDPOINT_XFER_INT,
257 	.wMaxPacketSize =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
258 	.bInterval =		NCM_STATUS_INTERVAL_MS,
259 };
260 
261 static struct usb_endpoint_descriptor fs_ncm_in_desc = {
262 	.bLength =		USB_DT_ENDPOINT_SIZE,
263 	.bDescriptorType =	USB_DT_ENDPOINT,
264 
265 	.bEndpointAddress =	USB_DIR_IN,
266 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
267 };
268 
269 static struct usb_endpoint_descriptor fs_ncm_out_desc = {
270 	.bLength =		USB_DT_ENDPOINT_SIZE,
271 	.bDescriptorType =	USB_DT_ENDPOINT,
272 
273 	.bEndpointAddress =	USB_DIR_OUT,
274 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
275 };
276 
277 static struct usb_descriptor_header *ncm_fs_function[] = {
278 	(struct usb_descriptor_header *) &ncm_iad_desc,
279 	/* CDC NCM control descriptors */
280 	(struct usb_descriptor_header *) &ncm_control_intf,
281 	(struct usb_descriptor_header *) &ncm_header_desc,
282 	(struct usb_descriptor_header *) &ncm_union_desc,
283 	(struct usb_descriptor_header *) &ecm_desc,
284 	(struct usb_descriptor_header *) &ncm_desc,
285 	(struct usb_descriptor_header *) &fs_ncm_notify_desc,
286 	/* data interface, altsettings 0 and 1 */
287 	(struct usb_descriptor_header *) &ncm_data_nop_intf,
288 	(struct usb_descriptor_header *) &ncm_data_intf,
289 	(struct usb_descriptor_header *) &fs_ncm_in_desc,
290 	(struct usb_descriptor_header *) &fs_ncm_out_desc,
291 	NULL,
292 };
293 
294 /* high speed support: */
295 
296 static struct usb_endpoint_descriptor hs_ncm_notify_desc = {
297 	.bLength =		USB_DT_ENDPOINT_SIZE,
298 	.bDescriptorType =	USB_DT_ENDPOINT,
299 
300 	.bEndpointAddress =	USB_DIR_IN,
301 	.bmAttributes =		USB_ENDPOINT_XFER_INT,
302 	.wMaxPacketSize =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
303 	.bInterval =		USB_MS_TO_HS_INTERVAL(NCM_STATUS_INTERVAL_MS),
304 };
305 static struct usb_endpoint_descriptor hs_ncm_in_desc = {
306 	.bLength =		USB_DT_ENDPOINT_SIZE,
307 	.bDescriptorType =	USB_DT_ENDPOINT,
308 
309 	.bEndpointAddress =	USB_DIR_IN,
310 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
311 	.wMaxPacketSize =	cpu_to_le16(512),
312 };
313 
314 static struct usb_endpoint_descriptor hs_ncm_out_desc = {
315 	.bLength =		USB_DT_ENDPOINT_SIZE,
316 	.bDescriptorType =	USB_DT_ENDPOINT,
317 
318 	.bEndpointAddress =	USB_DIR_OUT,
319 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
320 	.wMaxPacketSize =	cpu_to_le16(512),
321 };
322 
323 static struct usb_descriptor_header *ncm_hs_function[] = {
324 	(struct usb_descriptor_header *) &ncm_iad_desc,
325 	/* CDC NCM control descriptors */
326 	(struct usb_descriptor_header *) &ncm_control_intf,
327 	(struct usb_descriptor_header *) &ncm_header_desc,
328 	(struct usb_descriptor_header *) &ncm_union_desc,
329 	(struct usb_descriptor_header *) &ecm_desc,
330 	(struct usb_descriptor_header *) &ncm_desc,
331 	(struct usb_descriptor_header *) &hs_ncm_notify_desc,
332 	/* data interface, altsettings 0 and 1 */
333 	(struct usb_descriptor_header *) &ncm_data_nop_intf,
334 	(struct usb_descriptor_header *) &ncm_data_intf,
335 	(struct usb_descriptor_header *) &hs_ncm_in_desc,
336 	(struct usb_descriptor_header *) &hs_ncm_out_desc,
337 	NULL,
338 };
339 
340 
341 /* super speed support: */
342 
343 static struct usb_endpoint_descriptor ss_ncm_notify_desc = {
344 	.bLength =		USB_DT_ENDPOINT_SIZE,
345 	.bDescriptorType =	USB_DT_ENDPOINT,
346 
347 	.bEndpointAddress =	USB_DIR_IN,
348 	.bmAttributes =		USB_ENDPOINT_XFER_INT,
349 	.wMaxPacketSize =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
350 	.bInterval =		USB_MS_TO_HS_INTERVAL(NCM_STATUS_INTERVAL_MS)
351 };
352 
353 static struct usb_ss_ep_comp_descriptor ss_ncm_notify_comp_desc = {
354 	.bLength =		sizeof(ss_ncm_notify_comp_desc),
355 	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
356 
357 	/* the following 3 values can be tweaked if necessary */
358 	/* .bMaxBurst =		0, */
359 	/* .bmAttributes =	0, */
360 	.wBytesPerInterval =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
361 };
362 
363 static struct usb_endpoint_descriptor ss_ncm_in_desc = {
364 	.bLength =		USB_DT_ENDPOINT_SIZE,
365 	.bDescriptorType =	USB_DT_ENDPOINT,
366 
367 	.bEndpointAddress =	USB_DIR_IN,
368 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
369 	.wMaxPacketSize =	cpu_to_le16(1024),
370 };
371 
372 static struct usb_endpoint_descriptor ss_ncm_out_desc = {
373 	.bLength =		USB_DT_ENDPOINT_SIZE,
374 	.bDescriptorType =	USB_DT_ENDPOINT,
375 
376 	.bEndpointAddress =	USB_DIR_OUT,
377 	.bmAttributes =		USB_ENDPOINT_XFER_BULK,
378 	.wMaxPacketSize =	cpu_to_le16(1024),
379 };
380 
381 static struct usb_ss_ep_comp_descriptor ss_ncm_bulk_comp_desc = {
382 	.bLength =		sizeof(ss_ncm_bulk_comp_desc),
383 	.bDescriptorType =	USB_DT_SS_ENDPOINT_COMP,
384 
385 	/* the following 2 values can be tweaked if necessary */
386 	/* .bMaxBurst =		0, */
387 	/* .bmAttributes =	0, */
388 };
389 
390 static struct usb_descriptor_header *ncm_ss_function[] = {
391 	(struct usb_descriptor_header *) &ncm_iad_desc,
392 	/* CDC NCM control descriptors */
393 	(struct usb_descriptor_header *) &ncm_control_intf,
394 	(struct usb_descriptor_header *) &ncm_header_desc,
395 	(struct usb_descriptor_header *) &ncm_union_desc,
396 	(struct usb_descriptor_header *) &ecm_desc,
397 	(struct usb_descriptor_header *) &ncm_desc,
398 	(struct usb_descriptor_header *) &ss_ncm_notify_desc,
399 	(struct usb_descriptor_header *) &ss_ncm_notify_comp_desc,
400 	/* data interface, altsettings 0 and 1 */
401 	(struct usb_descriptor_header *) &ncm_data_nop_intf,
402 	(struct usb_descriptor_header *) &ncm_data_intf,
403 	(struct usb_descriptor_header *) &ss_ncm_in_desc,
404 	(struct usb_descriptor_header *) &ss_ncm_bulk_comp_desc,
405 	(struct usb_descriptor_header *) &ss_ncm_out_desc,
406 	(struct usb_descriptor_header *) &ss_ncm_bulk_comp_desc,
407 	NULL,
408 };
409 
410 /* string descriptors: */
411 
412 #define STRING_CTRL_IDX	0
413 #define STRING_MAC_IDX	1
414 #define STRING_DATA_IDX	2
415 #define STRING_IAD_IDX	3
416 
417 static struct usb_string ncm_string_defs[] = {
418 	[STRING_CTRL_IDX].s = "CDC Network Control Model (NCM)",
419 	[STRING_MAC_IDX].s = "",
420 	[STRING_DATA_IDX].s = "CDC Network Data",
421 	[STRING_IAD_IDX].s = "CDC NCM",
422 	{  } /* end of list */
423 };
424 
425 static struct usb_gadget_strings ncm_string_table = {
426 	.language =		0x0409,	/* en-us */
427 	.strings =		ncm_string_defs,
428 };
429 
430 static struct usb_gadget_strings *ncm_strings[] = {
431 	&ncm_string_table,
432 	NULL,
433 };
434 
435 /*
436  * Here are options for NCM Datagram Pointer table (NDP) parser.
437  * There are 2 different formats: NDP16 and NDP32 in the spec (ch. 3),
438  * in NDP16 offsets and sizes fields are 1 16bit word wide,
439  * in NDP32 -- 2 16bit words wide. Also signatures are different.
440  * To make the parser code the same, put the differences in the structure,
441  * and switch pointers to the structures when the format is changed.
442  */
443 
444 struct ndp_parser_opts {
445 	u32		nth_sign;
446 	u32		ndp_sign;
447 	unsigned	nth_size;
448 	unsigned	ndp_size;
449 	unsigned	dpe_size;
450 	unsigned	ndplen_align;
451 	/* sizes in u16 units */
452 	unsigned	dgram_item_len; /* index or length */
453 	unsigned	block_length;
454 	unsigned	ndp_index;
455 	unsigned	reserved1;
456 	unsigned	reserved2;
457 	unsigned	next_ndp_index;
458 };
459 
460 #define INIT_NDP16_OPTS {					\
461 		.nth_sign = USB_CDC_NCM_NTH16_SIGN,		\
462 		.ndp_sign = USB_CDC_NCM_NDP16_NOCRC_SIGN,	\
463 		.nth_size = sizeof(struct usb_cdc_ncm_nth16),	\
464 		.ndp_size = sizeof(struct usb_cdc_ncm_ndp16),	\
465 		.dpe_size = sizeof(struct usb_cdc_ncm_dpe16),	\
466 		.ndplen_align = 4,				\
467 		.dgram_item_len = 1,				\
468 		.block_length = 1,				\
469 		.ndp_index = 1,					\
470 		.reserved1 = 0,					\
471 		.reserved2 = 0,					\
472 		.next_ndp_index = 1,				\
473 	}
474 
475 
476 #define INIT_NDP32_OPTS {					\
477 		.nth_sign = USB_CDC_NCM_NTH32_SIGN,		\
478 		.ndp_sign = USB_CDC_NCM_NDP32_NOCRC_SIGN,	\
479 		.nth_size = sizeof(struct usb_cdc_ncm_nth32),	\
480 		.ndp_size = sizeof(struct usb_cdc_ncm_ndp32),	\
481 		.dpe_size = sizeof(struct usb_cdc_ncm_dpe32),	\
482 		.ndplen_align = 8,				\
483 		.dgram_item_len = 2,				\
484 		.block_length = 2,				\
485 		.ndp_index = 2,					\
486 		.reserved1 = 1,					\
487 		.reserved2 = 2,					\
488 		.next_ndp_index = 2,				\
489 	}
490 
491 static const struct ndp_parser_opts ndp16_opts = INIT_NDP16_OPTS;
492 static const struct ndp_parser_opts ndp32_opts = INIT_NDP32_OPTS;
493 
put_ncm(__le16 ** p,unsigned size,unsigned val)494 static inline void put_ncm(__le16 **p, unsigned size, unsigned val)
495 {
496 	switch (size) {
497 	case 1:
498 		put_unaligned_le16((u16)val, *p);
499 		break;
500 	case 2:
501 		put_unaligned_le32((u32)val, *p);
502 
503 		break;
504 	default:
505 		BUG();
506 	}
507 
508 	*p += size;
509 }
510 
get_ncm(__le16 ** p,unsigned size)511 static inline unsigned get_ncm(__le16 **p, unsigned size)
512 {
513 	unsigned tmp;
514 
515 	switch (size) {
516 	case 1:
517 		tmp = get_unaligned_le16(*p);
518 		break;
519 	case 2:
520 		tmp = get_unaligned_le32(*p);
521 		break;
522 	default:
523 		BUG();
524 	}
525 
526 	*p += size;
527 	return tmp;
528 }
529 
530 /*-------------------------------------------------------------------------*/
531 
ncm_reset_values(struct f_ncm * ncm)532 static inline void ncm_reset_values(struct f_ncm *ncm)
533 {
534 	ncm->parser_opts = &ndp16_opts;
535 	ncm->is_crc = false;
536 	ncm->port.cdc_filter = DEFAULT_FILTER;
537 
538 	/* doesn't make sense for ncm, fixed size used */
539 	ncm->port.header_len = 0;
540 
541 	ncm->port.fixed_out_len = le32_to_cpu(ntb_parameters.dwNtbOutMaxSize);
542 	ncm->port.fixed_in_len = NTB_DEFAULT_IN_SIZE;
543 }
544 
545 /*
546  * Context: ncm->lock held
547  */
ncm_do_notify(struct f_ncm * ncm)548 static void ncm_do_notify(struct f_ncm *ncm)
549 {
550 	struct usb_request		*req = ncm->notify_req;
551 	struct usb_cdc_notification	*event;
552 	struct usb_composite_dev	*cdev = ncm->port.func.config->cdev;
553 	__le32				*data;
554 	int				status;
555 
556 	/* notification already in flight? */
557 	if (atomic_read(&ncm->notify_count))
558 		return;
559 
560 	event = req->buf;
561 	switch (ncm->notify_state) {
562 	case NCM_NOTIFY_NONE:
563 		return;
564 
565 	case NCM_NOTIFY_CONNECT:
566 		event->bNotificationType = USB_CDC_NOTIFY_NETWORK_CONNECTION;
567 		if (ncm->is_open)
568 			event->wValue = cpu_to_le16(1);
569 		else
570 			event->wValue = cpu_to_le16(0);
571 		event->wLength = 0;
572 		req->length = sizeof *event;
573 
574 		DBG(cdev, "notify connect %s\n",
575 				ncm->is_open ? "true" : "false");
576 		ncm->notify_state = NCM_NOTIFY_NONE;
577 		break;
578 
579 	case NCM_NOTIFY_SPEED:
580 		event->bNotificationType = USB_CDC_NOTIFY_SPEED_CHANGE;
581 		event->wValue = cpu_to_le16(0);
582 		event->wLength = cpu_to_le16(8);
583 		req->length = NCM_STATUS_BYTECOUNT;
584 
585 		/* SPEED_CHANGE data is up/down speeds in bits/sec */
586 		data = req->buf + sizeof *event;
587 		data[0] = cpu_to_le32(ncm_bitrate(cdev->gadget));
588 		data[1] = data[0];
589 
590 		DBG(cdev, "notify speed %d\n", ncm_bitrate(cdev->gadget));
591 		ncm->notify_state = NCM_NOTIFY_CONNECT;
592 		break;
593 	}
594 	event->bmRequestType = 0xA1;
595 	event->wIndex = cpu_to_le16(ncm->ctrl_id);
596 
597 	atomic_inc(&ncm->notify_count);
598 
599 	/*
600 	 * In double buffering if there is a space in FIFO,
601 	 * completion callback can be called right after the call,
602 	 * so unlocking
603 	 */
604 	spin_unlock(&ncm->lock);
605 	status = usb_ep_queue(ncm->notify, req, GFP_ATOMIC);
606 	spin_lock(&ncm->lock);
607 	if (status < 0) {
608 		atomic_dec(&ncm->notify_count);
609 		DBG(cdev, "notify --> %d\n", status);
610 	}
611 }
612 
613 /*
614  * Context: ncm->lock held
615  */
ncm_notify(struct f_ncm * ncm)616 static void ncm_notify(struct f_ncm *ncm)
617 {
618 	/*
619 	 * NOTE on most versions of Linux, host side cdc-ethernet
620 	 * won't listen for notifications until its netdevice opens.
621 	 * The first notification then sits in the FIFO for a long
622 	 * time, and the second one is queued.
623 	 *
624 	 * If ncm_notify() is called before the second (CONNECT)
625 	 * notification is sent, then it will reset to send the SPEED
626 	 * notificaion again (and again, and again), but it's not a problem
627 	 */
628 	ncm->notify_state = NCM_NOTIFY_SPEED;
629 	ncm_do_notify(ncm);
630 }
631 
ncm_notify_complete(struct usb_ep * ep,struct usb_request * req)632 static void ncm_notify_complete(struct usb_ep *ep, struct usb_request *req)
633 {
634 	struct f_ncm			*ncm = req->context;
635 	struct usb_composite_dev	*cdev = ncm->port.func.config->cdev;
636 	struct usb_cdc_notification	*event = req->buf;
637 
638 	spin_lock(&ncm->lock);
639 	switch (req->status) {
640 	case 0:
641 		VDBG(cdev, "Notification %02x sent\n",
642 		     event->bNotificationType);
643 		atomic_dec(&ncm->notify_count);
644 		break;
645 	case -ECONNRESET:
646 	case -ESHUTDOWN:
647 		atomic_set(&ncm->notify_count, 0);
648 		ncm->notify_state = NCM_NOTIFY_NONE;
649 		break;
650 	default:
651 		DBG(cdev, "event %02x --> %d\n",
652 			event->bNotificationType, req->status);
653 		atomic_dec(&ncm->notify_count);
654 		break;
655 	}
656 	ncm_do_notify(ncm);
657 	spin_unlock(&ncm->lock);
658 }
659 
ncm_ep0out_complete(struct usb_ep * ep,struct usb_request * req)660 static void ncm_ep0out_complete(struct usb_ep *ep, struct usb_request *req)
661 {
662 	/* now for SET_NTB_INPUT_SIZE only */
663 	unsigned		in_size;
664 	struct usb_function	*f = req->context;
665 	struct f_ncm		*ncm = func_to_ncm(f);
666 	struct usb_composite_dev *cdev = f->config->cdev;
667 
668 	req->context = NULL;
669 	if (req->status || req->actual != req->length) {
670 		DBG(cdev, "Bad control-OUT transfer\n");
671 		goto invalid;
672 	}
673 
674 	in_size = get_unaligned_le32(req->buf);
675 	if (in_size < USB_CDC_NCM_NTB_MIN_IN_SIZE ||
676 	    in_size > le32_to_cpu(ntb_parameters.dwNtbInMaxSize)) {
677 		DBG(cdev, "Got wrong INPUT SIZE (%d) from host\n", in_size);
678 		goto invalid;
679 	}
680 
681 	ncm->port.fixed_in_len = in_size;
682 	VDBG(cdev, "Set NTB INPUT SIZE %d\n", in_size);
683 	return;
684 
685 invalid:
686 	usb_ep_set_halt(ep);
687 	return;
688 }
689 
ncm_setup(struct usb_function * f,const struct usb_ctrlrequest * ctrl)690 static int ncm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl)
691 {
692 	struct f_ncm		*ncm = func_to_ncm(f);
693 	struct usb_composite_dev *cdev = f->config->cdev;
694 	struct usb_request	*req = cdev->req;
695 	int			value = -EOPNOTSUPP;
696 	u16			w_index = le16_to_cpu(ctrl->wIndex);
697 	u16			w_value = le16_to_cpu(ctrl->wValue);
698 	u16			w_length = le16_to_cpu(ctrl->wLength);
699 
700 	/*
701 	 * composite driver infrastructure handles everything except
702 	 * CDC class messages; interface activation uses set_alt().
703 	 */
704 	switch ((ctrl->bRequestType << 8) | ctrl->bRequest) {
705 	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
706 			| USB_CDC_SET_ETHERNET_PACKET_FILTER:
707 		/*
708 		 * see 6.2.30: no data, wIndex = interface,
709 		 * wValue = packet filter bitmap
710 		 */
711 		if (w_length != 0 || w_index != ncm->ctrl_id)
712 			goto invalid;
713 		DBG(cdev, "packet filter %02x\n", w_value);
714 		/*
715 		 * REVISIT locking of cdc_filter.  This assumes the UDC
716 		 * driver won't have a concurrent packet TX irq running on
717 		 * another CPU; or that if it does, this write is atomic...
718 		 */
719 		ncm->port.cdc_filter = w_value;
720 		value = 0;
721 		break;
722 	/*
723 	 * and optionally:
724 	 * case USB_CDC_SEND_ENCAPSULATED_COMMAND:
725 	 * case USB_CDC_GET_ENCAPSULATED_RESPONSE:
726 	 * case USB_CDC_SET_ETHERNET_MULTICAST_FILTERS:
727 	 * case USB_CDC_SET_ETHERNET_PM_PATTERN_FILTER:
728 	 * case USB_CDC_GET_ETHERNET_PM_PATTERN_FILTER:
729 	 * case USB_CDC_GET_ETHERNET_STATISTIC:
730 	 */
731 
732 	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
733 		| USB_CDC_GET_NTB_PARAMETERS:
734 
735 		if (w_length == 0 || w_value != 0 || w_index != ncm->ctrl_id)
736 			goto invalid;
737 		value = w_length > sizeof ntb_parameters ?
738 			sizeof ntb_parameters : w_length;
739 		memcpy(req->buf, &ntb_parameters, value);
740 		VDBG(cdev, "Host asked NTB parameters\n");
741 		break;
742 
743 	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
744 		| USB_CDC_GET_NTB_INPUT_SIZE:
745 
746 		if (w_length < 4 || w_value != 0 || w_index != ncm->ctrl_id)
747 			goto invalid;
748 		put_unaligned_le32(ncm->port.fixed_in_len, req->buf);
749 		value = 4;
750 		VDBG(cdev, "Host asked INPUT SIZE, sending %d\n",
751 		     ncm->port.fixed_in_len);
752 		break;
753 
754 	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
755 		| USB_CDC_SET_NTB_INPUT_SIZE:
756 	{
757 		if (w_length != 4 || w_value != 0 || w_index != ncm->ctrl_id)
758 			goto invalid;
759 		req->complete = ncm_ep0out_complete;
760 		req->length = w_length;
761 		req->context = f;
762 
763 		value = req->length;
764 		break;
765 	}
766 
767 	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
768 		| USB_CDC_GET_NTB_FORMAT:
769 	{
770 		uint16_t format;
771 
772 		if (w_length < 2 || w_value != 0 || w_index != ncm->ctrl_id)
773 			goto invalid;
774 		format = (ncm->parser_opts == &ndp16_opts) ? 0x0000 : 0x0001;
775 		put_unaligned_le16(format, req->buf);
776 		value = 2;
777 		VDBG(cdev, "Host asked NTB FORMAT, sending %d\n", format);
778 		break;
779 	}
780 
781 	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
782 		| USB_CDC_SET_NTB_FORMAT:
783 	{
784 		if (w_length != 0 || w_index != ncm->ctrl_id)
785 			goto invalid;
786 		switch (w_value) {
787 		case 0x0000:
788 			ncm->parser_opts = &ndp16_opts;
789 			DBG(cdev, "NCM16 selected\n");
790 			break;
791 		case 0x0001:
792 			ncm->parser_opts = &ndp32_opts;
793 			DBG(cdev, "NCM32 selected\n");
794 			break;
795 		default:
796 			goto invalid;
797 		}
798 		value = 0;
799 		break;
800 	}
801 	case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
802 		| USB_CDC_GET_CRC_MODE:
803 	{
804 		uint16_t is_crc;
805 
806 		if (w_length < 2 || w_value != 0 || w_index != ncm->ctrl_id)
807 			goto invalid;
808 		is_crc = ncm->is_crc ? 0x0001 : 0x0000;
809 		put_unaligned_le16(is_crc, req->buf);
810 		value = 2;
811 		VDBG(cdev, "Host asked CRC MODE, sending %d\n", is_crc);
812 		break;
813 	}
814 
815 	case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8)
816 		| USB_CDC_SET_CRC_MODE:
817 	{
818 		int ndp_hdr_crc = 0;
819 
820 		if (w_length != 0 || w_index != ncm->ctrl_id)
821 			goto invalid;
822 		switch (w_value) {
823 		case 0x0000:
824 			ncm->is_crc = false;
825 			ndp_hdr_crc = NCM_NDP_HDR_NOCRC;
826 			DBG(cdev, "non-CRC mode selected\n");
827 			break;
828 		case 0x0001:
829 			ncm->is_crc = true;
830 			ndp_hdr_crc = NCM_NDP_HDR_CRC;
831 			DBG(cdev, "CRC mode selected\n");
832 			break;
833 		default:
834 			goto invalid;
835 		}
836 		ncm->ndp_sign = ncm->parser_opts->ndp_sign | ndp_hdr_crc;
837 		value = 0;
838 		break;
839 	}
840 
841 	/* and disabled in ncm descriptor: */
842 	/* case USB_CDC_GET_NET_ADDRESS: */
843 	/* case USB_CDC_SET_NET_ADDRESS: */
844 	/* case USB_CDC_GET_MAX_DATAGRAM_SIZE: */
845 	/* case USB_CDC_SET_MAX_DATAGRAM_SIZE: */
846 
847 	default:
848 invalid:
849 		DBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n",
850 			ctrl->bRequestType, ctrl->bRequest,
851 			w_value, w_index, w_length);
852 	}
853 
854 	/* respond with data transfer or status phase? */
855 	if (value >= 0) {
856 		DBG(cdev, "ncm req%02x.%02x v%04x i%04x l%d\n",
857 			ctrl->bRequestType, ctrl->bRequest,
858 			w_value, w_index, w_length);
859 		req->zero = 0;
860 		req->length = value;
861 		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
862 		if (value < 0)
863 			ERROR(cdev, "ncm req %02x.%02x response err %d\n",
864 					ctrl->bRequestType, ctrl->bRequest,
865 					value);
866 	}
867 
868 	/* device either stalls (value < 0) or reports success */
869 	return value;
870 }
871 
872 
ncm_set_alt(struct usb_function * f,unsigned intf,unsigned alt)873 static int ncm_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
874 {
875 	struct f_ncm		*ncm = func_to_ncm(f);
876 	struct usb_composite_dev *cdev = f->config->cdev;
877 
878 	/* Control interface has only altsetting 0 */
879 	if (intf == ncm->ctrl_id) {
880 		if (alt != 0)
881 			goto fail;
882 
883 		DBG(cdev, "reset ncm control %d\n", intf);
884 		usb_ep_disable(ncm->notify);
885 
886 		if (!(ncm->notify->desc)) {
887 			DBG(cdev, "init ncm ctrl %d\n", intf);
888 			if (config_ep_by_speed(cdev->gadget, f, ncm->notify))
889 				goto fail;
890 		}
891 		usb_ep_enable(ncm->notify);
892 
893 	/* Data interface has two altsettings, 0 and 1 */
894 	} else if (intf == ncm->data_id) {
895 		if (alt > 1)
896 			goto fail;
897 
898 		if (ncm->port.in_ep->enabled) {
899 			DBG(cdev, "reset ncm\n");
900 			ncm->timer_stopping = true;
901 			ncm->netdev = NULL;
902 			gether_disconnect(&ncm->port);
903 			ncm_reset_values(ncm);
904 		}
905 
906 		/*
907 		 * CDC Network only sends data in non-default altsettings.
908 		 * Changing altsettings resets filters, statistics, etc.
909 		 */
910 		if (alt == 1) {
911 			struct net_device	*net;
912 
913 			if (!ncm->port.in_ep->desc ||
914 			    !ncm->port.out_ep->desc) {
915 				DBG(cdev, "init ncm\n");
916 				if (config_ep_by_speed(cdev->gadget, f,
917 						       ncm->port.in_ep) ||
918 				    config_ep_by_speed(cdev->gadget, f,
919 						       ncm->port.out_ep)) {
920 					ncm->port.in_ep->desc = NULL;
921 					ncm->port.out_ep->desc = NULL;
922 					goto fail;
923 				}
924 			}
925 
926 			/* TODO */
927 			/* Enable zlps by default for NCM conformance;
928 			 * override for musb_hdrc (avoids txdma ovhead)
929 			 */
930 			ncm->port.is_zlp_ok =
931 				gadget_is_zlp_supported(cdev->gadget);
932 			ncm->port.cdc_filter = DEFAULT_FILTER;
933 			DBG(cdev, "activate ncm\n");
934 			net = gether_connect(&ncm->port);
935 			if (IS_ERR(net))
936 				return PTR_ERR(net);
937 			ncm->netdev = net;
938 			ncm->timer_stopping = false;
939 		}
940 
941 		spin_lock(&ncm->lock);
942 		ncm_notify(ncm);
943 		spin_unlock(&ncm->lock);
944 	} else
945 		goto fail;
946 
947 	return 0;
948 fail:
949 	return -EINVAL;
950 }
951 
952 /*
953  * Because the data interface supports multiple altsettings,
954  * this NCM function *MUST* implement a get_alt() method.
955  */
ncm_get_alt(struct usb_function * f,unsigned intf)956 static int ncm_get_alt(struct usb_function *f, unsigned intf)
957 {
958 	struct f_ncm		*ncm = func_to_ncm(f);
959 
960 	if (intf == ncm->ctrl_id)
961 		return 0;
962 	return ncm->port.in_ep->enabled ? 1 : 0;
963 }
964 
package_for_tx(struct f_ncm * ncm)965 static struct sk_buff *package_for_tx(struct f_ncm *ncm)
966 {
967 	__le16		*ntb_iter;
968 	struct sk_buff	*skb2 = NULL;
969 	unsigned	ndp_pad;
970 	unsigned	ndp_index;
971 	unsigned	new_len;
972 
973 	const struct ndp_parser_opts *opts = ncm->parser_opts;
974 	const int ndp_align = le16_to_cpu(ntb_parameters.wNdpInAlignment);
975 	const int dgram_idx_len = 2 * 2 * opts->dgram_item_len;
976 
977 	/* Stop the timer */
978 	hrtimer_try_to_cancel(&ncm->task_timer);
979 
980 	ndp_pad = ALIGN(ncm->skb_tx_data->len, ndp_align) -
981 			ncm->skb_tx_data->len;
982 	ndp_index = ncm->skb_tx_data->len + ndp_pad;
983 	new_len = ndp_index + dgram_idx_len + ncm->skb_tx_ndp->len;
984 
985 	/* Set the final BlockLength and wNdpIndex */
986 	ntb_iter = (void *) ncm->skb_tx_data->data;
987 	/* Increment pointer to BlockLength */
988 	ntb_iter += 2 + 1 + 1;
989 	put_ncm(&ntb_iter, opts->block_length, new_len);
990 	put_ncm(&ntb_iter, opts->ndp_index, ndp_index);
991 
992 	/* Set the final NDP wLength */
993 	new_len = opts->ndp_size +
994 			(ncm->ndp_dgram_count * dgram_idx_len);
995 	ncm->ndp_dgram_count = 0;
996 	/* Increment from start to wLength */
997 	ntb_iter = (void *) ncm->skb_tx_ndp->data;
998 	ntb_iter += 2;
999 	put_unaligned_le16(new_len, ntb_iter);
1000 
1001 	/* Merge the skbs */
1002 	swap(skb2, ncm->skb_tx_data);
1003 	if (ncm->skb_tx_data) {
1004 		dev_consume_skb_any(ncm->skb_tx_data);
1005 		ncm->skb_tx_data = NULL;
1006 	}
1007 
1008 	/* Insert NDP alignment. */
1009 	skb_put_zero(skb2, ndp_pad);
1010 
1011 	/* Copy NTB across. */
1012 	skb_put_data(skb2, ncm->skb_tx_ndp->data, ncm->skb_tx_ndp->len);
1013 	dev_consume_skb_any(ncm->skb_tx_ndp);
1014 	ncm->skb_tx_ndp = NULL;
1015 
1016 	/* Insert zero'd datagram. */
1017 	skb_put_zero(skb2, dgram_idx_len);
1018 
1019 	return skb2;
1020 }
1021 
ncm_wrap_ntb(struct gether * port,struct sk_buff * skb)1022 static 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 = 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 = skb_put_zero(ncm->skb_tx_data, ncb_len);
1083 			/* dwSignature */
1084 			put_unaligned_le32(opts->nth_sign, ntb_data);
1085 			ntb_data += 2;
1086 			/* wHeaderLength */
1087 			put_unaligned_le16(opts->nth_size, ntb_data++);
1088 
1089 			/* Allocate an skb for storing the NDP,
1090 			 * TX_MAX_NUM_DPE should easily suffice for a
1091 			 * 16k packet.
1092 			 */
1093 			ncm->skb_tx_ndp = alloc_skb((int)(opts->ndp_size
1094 						    + opts->dpe_size
1095 						    * TX_MAX_NUM_DPE),
1096 						    GFP_ATOMIC);
1097 			if (!ncm->skb_tx_ndp)
1098 				goto err;
1099 
1100 			ncm->skb_tx_ndp->dev = ncm->netdev;
1101 			ntb_ndp = skb_put(ncm->skb_tx_ndp, opts->ndp_size);
1102 			memset(ntb_ndp, 0, ncb_len);
1103 			/* dwSignature */
1104 			put_unaligned_le32(ncm->ndp_sign, ntb_ndp);
1105 			ntb_ndp += 2;
1106 
1107 			/* There is always a zeroed entry */
1108 			ncm->ndp_dgram_count = 1;
1109 
1110 			/* Note: we skip opts->next_ndp_index */
1111 		}
1112 
1113 		/* Delay the timer. */
1114 		hrtimer_start(&ncm->task_timer, TX_TIMEOUT_NSECS,
1115 			      HRTIMER_MODE_REL);
1116 
1117 		/* Add the datagram position entries */
1118 		ntb_ndp = skb_put_zero(ncm->skb_tx_ndp, dgram_idx_len);
1119 
1120 		ncb_len = ncm->skb_tx_data->len;
1121 		dgram_pad = ALIGN(ncb_len, div) + rem - ncb_len;
1122 		ncb_len += dgram_pad;
1123 
1124 		/* (d)wDatagramIndex */
1125 		put_ncm(&ntb_ndp, opts->dgram_item_len, ncb_len);
1126 		/* (d)wDatagramLength */
1127 		put_ncm(&ntb_ndp, opts->dgram_item_len, skb->len);
1128 		ncm->ndp_dgram_count++;
1129 
1130 		/* Add the new data to the skb */
1131 		skb_put_zero(ncm->skb_tx_data, dgram_pad);
1132 		skb_put_data(ncm->skb_tx_data, skb->data, skb->len);
1133 		dev_consume_skb_any(skb);
1134 		skb = NULL;
1135 
1136 	} else if (ncm->skb_tx_data && ncm->timer_force_tx) {
1137 		/* If the tx was requested because of a timeout then send */
1138 		skb2 = package_for_tx(ncm);
1139 		if (!skb2)
1140 			goto err;
1141 	}
1142 
1143 	return skb2;
1144 
1145 err:
1146 	ncm->netdev->stats.tx_dropped++;
1147 
1148 	if (skb)
1149 		dev_kfree_skb_any(skb);
1150 	if (ncm->skb_tx_data)
1151 		dev_kfree_skb_any(ncm->skb_tx_data);
1152 	if (ncm->skb_tx_ndp)
1153 		dev_kfree_skb_any(ncm->skb_tx_ndp);
1154 
1155 	return NULL;
1156 }
1157 
1158 /*
1159  * This transmits the NTB if there are frames waiting.
1160  */
ncm_tx_tasklet(unsigned long data)1161 static void ncm_tx_tasklet(unsigned long data)
1162 {
1163 	struct f_ncm	*ncm = (void *)data;
1164 
1165 	if (ncm->timer_stopping)
1166 		return;
1167 
1168 	/* Only send if data is available. */
1169 	if (ncm->skb_tx_data) {
1170 		ncm->timer_force_tx = true;
1171 
1172 		/* XXX This allowance of a NULL skb argument to ndo_start_xmit
1173 		 * XXX is not sane.  The gadget layer should be redesigned so
1174 		 * XXX that the dev->wrap() invocations to build SKBs is transparent
1175 		 * XXX and performed in some way outside of the ndo_start_xmit
1176 		 * XXX interface.
1177 		 */
1178 		ncm->netdev->netdev_ops->ndo_start_xmit(NULL, ncm->netdev);
1179 
1180 		ncm->timer_force_tx = false;
1181 	}
1182 }
1183 
1184 /*
1185  * The transmit should only be run if no skb data has been sent
1186  * for a certain duration.
1187  */
ncm_tx_timeout(struct hrtimer * data)1188 static enum hrtimer_restart ncm_tx_timeout(struct hrtimer *data)
1189 {
1190 	struct f_ncm *ncm = container_of(data, struct f_ncm, task_timer);
1191 	tasklet_schedule(&ncm->tx_tasklet);
1192 	return HRTIMER_NORESTART;
1193 }
1194 
ncm_unwrap_ntb(struct gether * port,struct sk_buff * skb,struct sk_buff_head * list)1195 static int ncm_unwrap_ntb(struct gether *port,
1196 			  struct sk_buff *skb,
1197 			  struct sk_buff_head *list)
1198 {
1199 	struct f_ncm	*ncm = func_to_ncm(&port->func);
1200 	__le16		*tmp = (void *) skb->data;
1201 	unsigned	index, index2;
1202 	int		ndp_index;
1203 	unsigned	dg_len, dg_len2;
1204 	unsigned	ndp_len;
1205 	struct sk_buff	*skb2;
1206 	int		ret = -EINVAL;
1207 	unsigned	max_size = le32_to_cpu(ntb_parameters.dwNtbOutMaxSize);
1208 	const struct ndp_parser_opts *opts = ncm->parser_opts;
1209 	unsigned	crc_len = ncm->is_crc ? sizeof(uint32_t) : 0;
1210 	int		dgram_counter;
1211 
1212 	/* dwSignature */
1213 	if (get_unaligned_le32(tmp) != opts->nth_sign) {
1214 		INFO(port->func.config->cdev, "Wrong NTH SIGN, skblen %d\n",
1215 			skb->len);
1216 		print_hex_dump(KERN_INFO, "HEAD:", DUMP_PREFIX_ADDRESS, 32, 1,
1217 			       skb->data, 32, false);
1218 
1219 		goto err;
1220 	}
1221 	tmp += 2;
1222 	/* wHeaderLength */
1223 	if (get_unaligned_le16(tmp++) != opts->nth_size) {
1224 		INFO(port->func.config->cdev, "Wrong NTB headersize\n");
1225 		goto err;
1226 	}
1227 	tmp++; /* skip wSequence */
1228 
1229 	/* (d)wBlockLength */
1230 	if (get_ncm(&tmp, opts->block_length) > max_size) {
1231 		INFO(port->func.config->cdev, "OUT size exceeded\n");
1232 		goto err;
1233 	}
1234 
1235 	ndp_index = get_ncm(&tmp, opts->ndp_index);
1236 
1237 	/* Run through all the NDP's in the NTB */
1238 	do {
1239 		/* NCM 3.2 */
1240 		if (((ndp_index % 4) != 0) &&
1241 				(ndp_index < opts->nth_size)) {
1242 			INFO(port->func.config->cdev, "Bad index: %#X\n",
1243 			     ndp_index);
1244 			goto err;
1245 		}
1246 
1247 		/* walk through NDP */
1248 		tmp = (void *)(skb->data + ndp_index);
1249 		if (get_unaligned_le32(tmp) != ncm->ndp_sign) {
1250 			INFO(port->func.config->cdev, "Wrong NDP SIGN\n");
1251 			goto err;
1252 		}
1253 		tmp += 2;
1254 
1255 		ndp_len = get_unaligned_le16(tmp++);
1256 		/*
1257 		 * NCM 3.3.1
1258 		 * entry is 2 items
1259 		 * item size is 16/32 bits, opts->dgram_item_len * 2 bytes
1260 		 * minimal: struct usb_cdc_ncm_ndpX + normal entry + zero entry
1261 		 * Each entry is a dgram index and a dgram length.
1262 		 */
1263 		if ((ndp_len < opts->ndp_size
1264 				+ 2 * 2 * (opts->dgram_item_len * 2))
1265 				|| (ndp_len % opts->ndplen_align != 0)) {
1266 			INFO(port->func.config->cdev, "Bad NDP length: %#X\n",
1267 			     ndp_len);
1268 			goto err;
1269 		}
1270 		tmp += opts->reserved1;
1271 		/* Check for another NDP (d)wNextNdpIndex */
1272 		ndp_index = get_ncm(&tmp, opts->next_ndp_index);
1273 		tmp += opts->reserved2;
1274 
1275 		ndp_len -= opts->ndp_size;
1276 		index2 = get_ncm(&tmp, opts->dgram_item_len);
1277 		dg_len2 = get_ncm(&tmp, opts->dgram_item_len);
1278 		dgram_counter = 0;
1279 
1280 		do {
1281 			index = index2;
1282 			dg_len = dg_len2;
1283 			if (dg_len < 14 + crc_len) { /* ethernet hdr + crc */
1284 				INFO(port->func.config->cdev,
1285 				     "Bad dgram length: %#X\n", dg_len);
1286 				goto err;
1287 			}
1288 			if (ncm->is_crc) {
1289 				uint32_t crc, crc2;
1290 
1291 				crc = get_unaligned_le32(skb->data +
1292 							 index + dg_len -
1293 							 crc_len);
1294 				crc2 = ~crc32_le(~0,
1295 						 skb->data + index,
1296 						 dg_len - crc_len);
1297 				if (crc != crc2) {
1298 					INFO(port->func.config->cdev,
1299 					     "Bad CRC\n");
1300 					goto err;
1301 				}
1302 			}
1303 
1304 			index2 = get_ncm(&tmp, opts->dgram_item_len);
1305 			dg_len2 = get_ncm(&tmp, opts->dgram_item_len);
1306 
1307 			/*
1308 			 * Copy the data into a new skb.
1309 			 * This ensures the truesize is correct
1310 			 */
1311 			skb2 = netdev_alloc_skb_ip_align(ncm->netdev,
1312 							 dg_len - crc_len);
1313 			if (skb2 == NULL)
1314 				goto err;
1315 			skb_put_data(skb2, skb->data + index,
1316 				     dg_len - crc_len);
1317 
1318 			skb_queue_tail(list, skb2);
1319 
1320 			ndp_len -= 2 * (opts->dgram_item_len * 2);
1321 
1322 			dgram_counter++;
1323 
1324 			if (index2 == 0 || dg_len2 == 0)
1325 				break;
1326 		} while (ndp_len > 2 * (opts->dgram_item_len * 2));
1327 	} while (ndp_index);
1328 
1329 	dev_consume_skb_any(skb);
1330 
1331 	VDBG(port->func.config->cdev,
1332 	     "Parsed NTB with %d frames\n", dgram_counter);
1333 	return 0;
1334 err:
1335 	skb_queue_purge(list);
1336 	dev_kfree_skb_any(skb);
1337 	return ret;
1338 }
1339 
ncm_disable(struct usb_function * f)1340 static void ncm_disable(struct usb_function *f)
1341 {
1342 	struct f_ncm		*ncm = func_to_ncm(f);
1343 	struct usb_composite_dev *cdev = f->config->cdev;
1344 
1345 	DBG(cdev, "ncm deactivated\n");
1346 
1347 	if (ncm->port.in_ep->enabled) {
1348 		ncm->timer_stopping = true;
1349 		ncm->netdev = NULL;
1350 		gether_disconnect(&ncm->port);
1351 	}
1352 
1353 	if (ncm->notify->enabled) {
1354 		usb_ep_disable(ncm->notify);
1355 		ncm->notify->desc = NULL;
1356 	}
1357 }
1358 
1359 /*-------------------------------------------------------------------------*/
1360 
1361 /*
1362  * Callbacks let us notify the host about connect/disconnect when the
1363  * net device is opened or closed.
1364  *
1365  * For testing, note that link states on this side include both opened
1366  * and closed variants of:
1367  *
1368  *   - disconnected/unconfigured
1369  *   - configured but inactive (data alt 0)
1370  *   - configured and active (data alt 1)
1371  *
1372  * Each needs to be tested with unplug, rmmod, SET_CONFIGURATION, and
1373  * SET_INTERFACE (altsetting).  Remember also that "configured" doesn't
1374  * imply the host is actually polling the notification endpoint, and
1375  * likewise that "active" doesn't imply it's actually using the data
1376  * endpoints for traffic.
1377  */
1378 
ncm_open(struct gether * geth)1379 static void ncm_open(struct gether *geth)
1380 {
1381 	struct f_ncm		*ncm = func_to_ncm(&geth->func);
1382 
1383 	DBG(ncm->port.func.config->cdev, "%s\n", __func__);
1384 
1385 	spin_lock(&ncm->lock);
1386 	ncm->is_open = true;
1387 	ncm_notify(ncm);
1388 	spin_unlock(&ncm->lock);
1389 }
1390 
ncm_close(struct gether * geth)1391 static void ncm_close(struct gether *geth)
1392 {
1393 	struct f_ncm		*ncm = func_to_ncm(&geth->func);
1394 
1395 	DBG(ncm->port.func.config->cdev, "%s\n", __func__);
1396 
1397 	spin_lock(&ncm->lock);
1398 	ncm->is_open = false;
1399 	ncm_notify(ncm);
1400 	spin_unlock(&ncm->lock);
1401 }
1402 
1403 /*-------------------------------------------------------------------------*/
1404 
1405 /* ethernet function driver setup/binding */
1406 
ncm_bind(struct usb_configuration * c,struct usb_function * f)1407 static int ncm_bind(struct usb_configuration *c, struct usb_function *f)
1408 {
1409 	struct usb_composite_dev *cdev = c->cdev;
1410 	struct f_ncm		*ncm = func_to_ncm(f);
1411 	struct usb_string	*us;
1412 	int			status;
1413 	struct usb_ep		*ep;
1414 	struct f_ncm_opts	*ncm_opts;
1415 
1416 	if (!can_support_ecm(cdev->gadget))
1417 		return -EINVAL;
1418 
1419 	ncm_opts = container_of(f->fi, struct f_ncm_opts, func_inst);
1420 	/*
1421 	 * in drivers/usb/gadget/configfs.c:configfs_composite_bind()
1422 	 * configurations are bound in sequence with list_for_each_entry,
1423 	 * in each configuration its functions are bound in sequence
1424 	 * with list_for_each_entry, so we assume no race condition
1425 	 * with regard to ncm_opts->bound access
1426 	 */
1427 	if (!ncm_opts->bound) {
1428 		mutex_lock(&ncm_opts->lock);
1429 		gether_set_gadget(ncm_opts->net, cdev->gadget);
1430 		status = gether_register_netdev(ncm_opts->net);
1431 		mutex_unlock(&ncm_opts->lock);
1432 		if (status)
1433 			return status;
1434 		ncm_opts->bound = true;
1435 	}
1436 	us = usb_gstrings_attach(cdev, ncm_strings,
1437 				 ARRAY_SIZE(ncm_string_defs));
1438 	if (IS_ERR(us))
1439 		return PTR_ERR(us);
1440 	ncm_control_intf.iInterface = us[STRING_CTRL_IDX].id;
1441 	ncm_data_nop_intf.iInterface = us[STRING_DATA_IDX].id;
1442 	ncm_data_intf.iInterface = us[STRING_DATA_IDX].id;
1443 	ecm_desc.iMACAddress = us[STRING_MAC_IDX].id;
1444 	ncm_iad_desc.iFunction = us[STRING_IAD_IDX].id;
1445 
1446 	/* allocate instance-specific interface IDs */
1447 	status = usb_interface_id(c, f);
1448 	if (status < 0)
1449 		goto fail;
1450 	ncm->ctrl_id = status;
1451 	ncm_iad_desc.bFirstInterface = status;
1452 
1453 	ncm_control_intf.bInterfaceNumber = status;
1454 	ncm_union_desc.bMasterInterface0 = status;
1455 
1456 	status = usb_interface_id(c, f);
1457 	if (status < 0)
1458 		goto fail;
1459 	ncm->data_id = status;
1460 
1461 	ncm_data_nop_intf.bInterfaceNumber = status;
1462 	ncm_data_intf.bInterfaceNumber = status;
1463 	ncm_union_desc.bSlaveInterface0 = status;
1464 
1465 	status = -ENODEV;
1466 
1467 	/* allocate instance-specific endpoints */
1468 	ep = usb_ep_autoconfig(cdev->gadget, &fs_ncm_in_desc);
1469 	if (!ep)
1470 		goto fail;
1471 	ncm->port.in_ep = ep;
1472 
1473 	ep = usb_ep_autoconfig(cdev->gadget, &fs_ncm_out_desc);
1474 	if (!ep)
1475 		goto fail;
1476 	ncm->port.out_ep = ep;
1477 
1478 	ep = usb_ep_autoconfig(cdev->gadget, &fs_ncm_notify_desc);
1479 	if (!ep)
1480 		goto fail;
1481 	ncm->notify = ep;
1482 
1483 	status = -ENOMEM;
1484 
1485 	/* allocate notification request and buffer */
1486 	ncm->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL);
1487 	if (!ncm->notify_req)
1488 		goto fail;
1489 	ncm->notify_req->buf = kmalloc(NCM_STATUS_BYTECOUNT, GFP_KERNEL);
1490 	if (!ncm->notify_req->buf)
1491 		goto fail;
1492 	ncm->notify_req->context = ncm;
1493 	ncm->notify_req->complete = ncm_notify_complete;
1494 
1495 	/*
1496 	 * support all relevant hardware speeds... we expect that when
1497 	 * hardware is dual speed, all bulk-capable endpoints work at
1498 	 * both speeds
1499 	 */
1500 	hs_ncm_in_desc.bEndpointAddress = fs_ncm_in_desc.bEndpointAddress;
1501 	hs_ncm_out_desc.bEndpointAddress = fs_ncm_out_desc.bEndpointAddress;
1502 	hs_ncm_notify_desc.bEndpointAddress =
1503 		fs_ncm_notify_desc.bEndpointAddress;
1504 
1505 	ss_ncm_in_desc.bEndpointAddress = fs_ncm_in_desc.bEndpointAddress;
1506 	ss_ncm_out_desc.bEndpointAddress = fs_ncm_out_desc.bEndpointAddress;
1507 	ss_ncm_notify_desc.bEndpointAddress =
1508 		fs_ncm_notify_desc.bEndpointAddress;
1509 
1510 	status = usb_assign_descriptors(f, ncm_fs_function, ncm_hs_function,
1511 			ncm_ss_function, NULL);
1512 	if (status)
1513 		goto fail;
1514 
1515 	/*
1516 	 * NOTE:  all that is done without knowing or caring about
1517 	 * the network link ... which is unavailable to this code
1518 	 * until we're activated via set_alt().
1519 	 */
1520 
1521 	ncm->port.open = ncm_open;
1522 	ncm->port.close = ncm_close;
1523 
1524 	tasklet_init(&ncm->tx_tasklet, ncm_tx_tasklet, (unsigned long) ncm);
1525 	hrtimer_init(&ncm->task_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1526 	ncm->task_timer.function = ncm_tx_timeout;
1527 
1528 	DBG(cdev, "CDC Network: %s speed IN/%s OUT/%s NOTIFY/%s\n",
1529 			gadget_is_superspeed(c->cdev->gadget) ? "super" :
1530 			gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
1531 			ncm->port.in_ep->name, ncm->port.out_ep->name,
1532 			ncm->notify->name);
1533 	return 0;
1534 
1535 fail:
1536 	if (ncm->notify_req) {
1537 		kfree(ncm->notify_req->buf);
1538 		usb_ep_free_request(ncm->notify, ncm->notify_req);
1539 	}
1540 
1541 	ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
1542 
1543 	return status;
1544 }
1545 
to_f_ncm_opts(struct config_item * item)1546 static inline struct f_ncm_opts *to_f_ncm_opts(struct config_item *item)
1547 {
1548 	return container_of(to_config_group(item), struct f_ncm_opts,
1549 			    func_inst.group);
1550 }
1551 
1552 /* f_ncm_item_ops */
1553 USB_ETHERNET_CONFIGFS_ITEM(ncm);
1554 
1555 /* f_ncm_opts_dev_addr */
1556 USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(ncm);
1557 
1558 /* f_ncm_opts_host_addr */
1559 USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(ncm);
1560 
1561 /* f_ncm_opts_qmult */
1562 USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(ncm);
1563 
1564 /* f_ncm_opts_ifname */
1565 USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(ncm);
1566 
1567 static struct configfs_attribute *ncm_attrs[] = {
1568 	&ncm_opts_attr_dev_addr,
1569 	&ncm_opts_attr_host_addr,
1570 	&ncm_opts_attr_qmult,
1571 	&ncm_opts_attr_ifname,
1572 	NULL,
1573 };
1574 
1575 static struct config_item_type ncm_func_type = {
1576 	.ct_item_ops	= &ncm_item_ops,
1577 	.ct_attrs	= ncm_attrs,
1578 	.ct_owner	= THIS_MODULE,
1579 };
1580 
ncm_free_inst(struct usb_function_instance * f)1581 static void ncm_free_inst(struct usb_function_instance *f)
1582 {
1583 	struct f_ncm_opts *opts;
1584 
1585 	opts = container_of(f, struct f_ncm_opts, func_inst);
1586 	if (opts->bound)
1587 		gether_cleanup(netdev_priv(opts->net));
1588 	else
1589 		free_netdev(opts->net);
1590 	kfree(opts);
1591 }
1592 
ncm_alloc_inst(void)1593 static struct usb_function_instance *ncm_alloc_inst(void)
1594 {
1595 	struct f_ncm_opts *opts;
1596 
1597 	opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1598 	if (!opts)
1599 		return ERR_PTR(-ENOMEM);
1600 	mutex_init(&opts->lock);
1601 	opts->func_inst.free_func_inst = ncm_free_inst;
1602 	opts->net = gether_setup_default();
1603 	if (IS_ERR(opts->net)) {
1604 		struct net_device *net = opts->net;
1605 		kfree(opts);
1606 		return ERR_CAST(net);
1607 	}
1608 
1609 	config_group_init_type_name(&opts->func_inst.group, "", &ncm_func_type);
1610 
1611 	return &opts->func_inst;
1612 }
1613 
ncm_free(struct usb_function * f)1614 static void ncm_free(struct usb_function *f)
1615 {
1616 	struct f_ncm *ncm;
1617 	struct f_ncm_opts *opts;
1618 
1619 	ncm = func_to_ncm(f);
1620 	opts = container_of(f->fi, struct f_ncm_opts, func_inst);
1621 	kfree(ncm);
1622 	mutex_lock(&opts->lock);
1623 	opts->refcnt--;
1624 	mutex_unlock(&opts->lock);
1625 }
1626 
ncm_unbind(struct usb_configuration * c,struct usb_function * f)1627 static void ncm_unbind(struct usb_configuration *c, struct usb_function *f)
1628 {
1629 	struct f_ncm *ncm = func_to_ncm(f);
1630 
1631 	DBG(c->cdev, "ncm unbind\n");
1632 
1633 	hrtimer_cancel(&ncm->task_timer);
1634 	tasklet_kill(&ncm->tx_tasklet);
1635 
1636 	ncm_string_defs[0].id = 0;
1637 	usb_free_all_descriptors(f);
1638 
1639 	if (atomic_read(&ncm->notify_count)) {
1640 		usb_ep_dequeue(ncm->notify, ncm->notify_req);
1641 		atomic_set(&ncm->notify_count, 0);
1642 	}
1643 
1644 	kfree(ncm->notify_req->buf);
1645 	usb_ep_free_request(ncm->notify, ncm->notify_req);
1646 }
1647 
ncm_alloc(struct usb_function_instance * fi)1648 static 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 
1696 DECLARE_USB_FUNCTION_INIT(ncm, ncm_alloc_inst, ncm_alloc);
1697 MODULE_LICENSE("GPL");
1698 MODULE_AUTHOR("Yauheni Kaliuta");
1699