xref: /freebsd/sys/dev/usb/net/if_cdceem.c (revision ccfd87fe2ac0e2e6aeb1911a7d7cce6712a8564f)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (C) 2012 Ben Gray <bgray@freebsd.org>.
5  * Copyright (C) 2018 The FreeBSD Foundation.
6  * Copyright (c) 2019 Edward Tomasz Napierala <trasz@FreeBSD.org>
7  *
8  * This software was developed by Arshan Khanifar <arshankhanifar@gmail.com>
9  * under sponsorship from the FreeBSD Foundation.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 /*
34  * Universal Serial Bus Communications Class Subclass Specification
35  * for Ethernet Emulation Model Devices:
36  *
37  * https://usb.org/sites/default/files/CDC_EEM10.pdf
38  */
39 
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
42 
43 #include <sys/gsb_crc32.h>
44 #include <sys/eventhandler.h>
45 #include <sys/stdint.h>
46 #include <sys/stddef.h>
47 #include <sys/queue.h>
48 #include <sys/systm.h>
49 #include <sys/socket.h>
50 #include <sys/kernel.h>
51 #include <sys/bus.h>
52 #include <sys/module.h>
53 #include <sys/lock.h>
54 #include <sys/mutex.h>
55 #include <sys/condvar.h>
56 #include <sys/sysctl.h>
57 #include <sys/sx.h>
58 #include <sys/unistd.h>
59 #include <sys/callout.h>
60 #include <sys/malloc.h>
61 #include <sys/priv.h>
62 
63 #include <net/if.h>
64 #include <net/if_var.h>
65 
66 #include <dev/usb/usb.h>
67 #include <dev/usb/usbdi.h>
68 #include <dev/usb/usbdi_util.h>
69 #include <dev/usb/usb_cdc.h>
70 #include "usbdevs.h"
71 
72 #define	USB_DEBUG_VAR cdceem_debug
73 #include <dev/usb/usb_debug.h>
74 #include <dev/usb/usb_process.h>
75 #include <dev/usb/usb_msctest.h>
76 #include "usb_if.h"
77 
78 #include <dev/usb/net/usb_ethernet.h>
79 
80 #define	CDCEEM_FRAMES_MAX	1
81 #define	CDCEEM_ECHO_MAX		1024
82 
83 #define	CDCEEM_ECHO_PAYLOAD	\
84     "ICH DALEKOPIS FALSZUJE GDY PROBY XQV NIE WYTRZYMUJE 1234567890"
85 
86 enum {
87 	CDCEEM_BULK_RX,
88 	CDCEEM_BULK_TX,
89 	CDCEEM_N_TRANSFER,
90 };
91 
92 struct cdceem_softc {
93 	struct usb_ether	sc_ue;
94 	struct mtx		sc_mtx;
95 	int			sc_flags;
96 	struct usb_xfer		*sc_xfer[CDCEEM_N_TRANSFER];
97 	size_t			sc_echo_len;
98 	char			sc_echo_buffer[CDCEEM_ECHO_MAX];
99 };
100 
101 #define	CDCEEM_SC_FLAGS_ECHO_RESPONSE_PENDING	0x1
102 #define	CDCEEM_SC_FLAGS_ECHO_PENDING		0x2
103 
104 static SYSCTL_NODE(_hw_usb, OID_AUTO, cdceem, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
105     "USB CDC EEM");
106 static int cdceem_debug = 1;
107 SYSCTL_INT(_hw_usb_cdceem, OID_AUTO, debug, CTLFLAG_RWTUN,
108     &cdceem_debug, 0, "Debug level");
109 static int cdceem_send_echoes = 0;
110 SYSCTL_INT(_hw_usb_cdceem, OID_AUTO, send_echoes, CTLFLAG_RWTUN,
111     &cdceem_send_echoes, 0, "Send an Echo command");
112 static int cdceem_send_fake_crc = 0;
113 SYSCTL_INT(_hw_usb_cdceem, OID_AUTO, send_fake_crc, CTLFLAG_RWTUN,
114     &cdceem_send_fake_crc, 0, "Use 0xdeadbeef instead of CRC");
115 
116 #define	CDCEEM_DEBUG(S, X, ...)						\
117 	do {								\
118 		if (cdceem_debug > 1) {					\
119 			device_printf(S->sc_ue.ue_dev, "%s: " X "\n",	\
120 			    __func__, ## __VA_ARGS__);			\
121 		}							\
122 	} while (0)
123 
124 #define	CDCEEM_WARN(S, X, ...)						\
125 	do {								\
126 		if (cdceem_debug > 0) {					\
127 			device_printf(S->sc_ue.ue_dev,			\
128 			    "WARNING: %s: " X "\n",			\
129 			    __func__, ## __VA_ARGS__);			\
130 		}							\
131 	} while (0)
132 
133 #define	CDCEEM_LOCK(X)				mtx_lock(&(X)->sc_mtx)
134 #define	CDCEEM_UNLOCK(X)			mtx_unlock(&(X)->sc_mtx)
135 
136 #define	CDCEEM_TYPE_CMD				(0x1 << 15)
137 
138 #define	CDCEEM_CMD_MASK				(0x7 << 11)
139 
140 #define	CDCEEM_CMD_ECHO				(0x0 << 11)
141 #define	CDCEEM_CMD_ECHO_RESPONSE		(0x1 << 11)
142 #define	CDCEEM_CMD_SUSPEND_HINT			(0x2 << 11)
143 #define	CDCEEM_CMD_RESPONSE_HINT		(0x3 << 11)
144 #define	CDCEEM_CMD_RESPONSE_COMPLETE_HINT	(0x4 << 11)
145 #define	CDCEEM_CMD_TICKLE			(0x5 << 11)
146 
147 #define	CDCEEM_CMD_RESERVED			(0x1 << 14)
148 
149 #define	CDCEEM_ECHO_LEN_MASK			0x3ff
150 
151 #define	CDCEEM_DATA_CRC				(0x1 << 14)
152 #define	CDCEEM_DATA_LEN_MASK			0x3fff
153 
154 static device_probe_t cdceem_probe;
155 static device_attach_t cdceem_attach;
156 static device_detach_t cdceem_detach;
157 static device_suspend_t cdceem_suspend;
158 static device_resume_t cdceem_resume;
159 
160 static usb_callback_t cdceem_bulk_write_callback;
161 static usb_callback_t cdceem_bulk_read_callback;
162 
163 static uether_fn_t cdceem_attach_post;
164 static uether_fn_t cdceem_init;
165 static uether_fn_t cdceem_stop;
166 static uether_fn_t cdceem_start;
167 static uether_fn_t cdceem_setmulti;
168 static uether_fn_t cdceem_setpromisc;
169 
170 static uint32_t	cdceem_m_crc32(struct mbuf *, uint32_t, uint32_t);
171 
172 static const struct usb_config cdceem_config[CDCEEM_N_TRANSFER] = {
173 	[CDCEEM_BULK_TX] = {
174 		.type = UE_BULK,
175 		.endpoint = UE_ADDR_ANY,
176 		.direction = UE_DIR_TX,
177 		.bufsize = 16 * (MCLBYTES + 16),
178 		.flags = {.pipe_bof = 1,.force_short_xfer = 1,},
179 		.callback = cdceem_bulk_write_callback,
180 		.timeout = 10000,	/* 10 seconds */
181 		.usb_mode = USB_MODE_DUAL,
182 	},
183 
184 	[CDCEEM_BULK_RX] = {
185 		.type = UE_BULK,
186 		.endpoint = UE_ADDR_ANY,
187 		.direction = UE_DIR_RX,
188 		.bufsize = 20480,	/* bytes */
189 		.flags = {.pipe_bof = 1,.short_xfer_ok = 1,},
190 		.callback = cdceem_bulk_read_callback,
191 		.timeout = 0,	/* no timeout */
192 		.usb_mode = USB_MODE_DUAL,
193 	},
194 };
195 
196 static device_method_t cdceem_methods[] = {
197 	/* Device interface */
198 	DEVMETHOD(device_probe, cdceem_probe),
199 	DEVMETHOD(device_attach, cdceem_attach),
200 	DEVMETHOD(device_detach, cdceem_detach),
201 	DEVMETHOD(device_suspend, cdceem_suspend),
202 	DEVMETHOD(device_resume, cdceem_resume),
203 
204 	DEVMETHOD_END
205 };
206 
207 static driver_t cdceem_driver = {
208 	.name = "cdceem",
209 	.methods = cdceem_methods,
210 	.size = sizeof(struct cdceem_softc),
211 };
212 
213 static const STRUCT_USB_DUAL_ID cdceem_dual_devs[] = {
214 	{USB_IFACE_CLASS(UICLASS_CDC),
215 		USB_IFACE_SUBCLASS(UISUBCLASS_ETHERNET_EMULATION_MODEL),
216 		0},
217 };
218 
219 DRIVER_MODULE(cdceem, uhub, cdceem_driver, NULL, NULL);
220 MODULE_VERSION(cdceem, 1);
221 MODULE_DEPEND(cdceem, uether, 1, 1, 1);
222 MODULE_DEPEND(cdceem, usb, 1, 1, 1);
223 MODULE_DEPEND(cdceem, ether, 1, 1, 1);
224 USB_PNP_DUAL_INFO(cdceem_dual_devs);
225 
226 static const struct usb_ether_methods cdceem_ue_methods = {
227 	.ue_attach_post = cdceem_attach_post,
228 	.ue_start = cdceem_start,
229 	.ue_init = cdceem_init,
230 	.ue_stop = cdceem_stop,
231 	.ue_setmulti = cdceem_setmulti,
232 	.ue_setpromisc = cdceem_setpromisc,
233 };
234 
235 static int
236 cdceem_probe(device_t dev)
237 {
238 	struct usb_attach_arg *uaa;
239 	int error;
240 
241 	uaa = device_get_ivars(dev);
242 	error = usbd_lookup_id_by_uaa(cdceem_dual_devs,
243 	    sizeof(cdceem_dual_devs), uaa);
244 
245 	return (error);
246 }
247 
248 static void
249 cdceem_attach_post(struct usb_ether *ue)
250 {
251 
252 	return;
253 }
254 
255 static int
256 cdceem_attach(device_t dev)
257 {
258 	struct cdceem_softc *sc;
259 	struct usb_ether *ue;
260 	struct usb_attach_arg *uaa;
261 	int error;
262 	uint8_t iface_index;
263 
264 	sc = device_get_softc(dev);
265 	ue = &sc->sc_ue;
266 	uaa = device_get_ivars(dev);
267 
268 	device_set_usb_desc(dev);
269 
270 	mtx_init(&sc->sc_mtx, device_get_nameunit(dev), NULL, MTX_DEF);
271 
272 	/* Setup the endpoints. */
273 	iface_index = 0;
274 	error = usbd_transfer_setup(uaa->device, &iface_index, sc->sc_xfer,
275 	    cdceem_config, CDCEEM_N_TRANSFER, sc, &sc->sc_mtx);
276 	if (error != 0) {
277 		CDCEEM_WARN(sc,
278 		    "allocating USB transfers failed, error %d", error);
279 		mtx_destroy(&sc->sc_mtx);
280 		return (error);
281 	}
282 
283 	/* Random MAC address. */
284 	arc4rand(ue->ue_eaddr, ETHER_ADDR_LEN, 0);
285 	ue->ue_eaddr[0] &= ~0x01;	/* unicast */
286 	ue->ue_eaddr[0] |= 0x02;	/* locally administered */
287 
288 	ue->ue_sc = sc;
289 	ue->ue_dev = dev;
290 	ue->ue_udev = uaa->device;
291 	ue->ue_mtx = &sc->sc_mtx;
292 	ue->ue_methods = &cdceem_ue_methods;
293 
294 	error = uether_ifattach(ue);
295 	if (error != 0) {
296 		CDCEEM_WARN(sc, "could not attach interface, error %d", error);
297 		usbd_transfer_unsetup(sc->sc_xfer, CDCEEM_N_TRANSFER);
298 		mtx_destroy(&sc->sc_mtx);
299 		return (error);
300 	}
301 
302 	return (0);
303 }
304 
305 static int
306 cdceem_detach(device_t dev)
307 {
308 	struct cdceem_softc *sc = device_get_softc(dev);
309 	struct usb_ether *ue = &sc->sc_ue;
310 
311 	/* Stop all USB transfers first. */
312 	usbd_transfer_unsetup(sc->sc_xfer, CDCEEM_N_TRANSFER);
313 	uether_ifdetach(ue);
314 	mtx_destroy(&sc->sc_mtx);
315 
316 	return (0);
317 }
318 
319 static void
320 cdceem_handle_cmd(struct usb_xfer *xfer, uint16_t hdr, int *offp)
321 {
322 	struct cdceem_softc *sc;
323 	struct usb_page_cache *pc;
324 	int actlen, off;
325 	uint16_t pktlen;
326 
327 	off = *offp;
328 	sc = usbd_xfer_softc(xfer);
329 	pc = usbd_xfer_get_frame(xfer, 0);
330 	usbd_xfer_status(xfer, &actlen, NULL, NULL, NULL);
331 
332 	if (hdr & CDCEEM_CMD_RESERVED) {
333 		CDCEEM_WARN(sc, "received command header %#x "
334 		    "with Reserved bit set; ignoring", hdr);
335 		return;
336 	}
337 
338 	switch (hdr & CDCEEM_CMD_MASK) {
339 	case CDCEEM_CMD_ECHO:
340 		pktlen = hdr & CDCEEM_ECHO_LEN_MASK;
341 		CDCEEM_DEBUG(sc, "received Echo, length %d", pktlen);
342 
343 		if (pktlen > (actlen - off)) {
344 			CDCEEM_WARN(sc,
345 			    "bad Echo length %d, should be at most %d",
346 			    pktlen, actlen - off);
347 			break;
348 		}
349 
350 		if (pktlen > sizeof(sc->sc_echo_buffer)) {
351 			CDCEEM_WARN(sc,
352 			    "Echo length %u too big, must be less than %zd",
353 			    pktlen, sizeof(sc->sc_echo_buffer));
354 			break;
355 		}
356 
357 		sc->sc_flags |= CDCEEM_SC_FLAGS_ECHO_RESPONSE_PENDING;
358 		sc->sc_echo_len = pktlen;
359 		usbd_copy_out(pc, off, sc->sc_echo_buffer, pktlen);
360 		off += pktlen;
361 		break;
362 
363 	case CDCEEM_CMD_ECHO_RESPONSE:
364 		pktlen = hdr & CDCEEM_ECHO_LEN_MASK;
365 		CDCEEM_DEBUG(sc, "received Echo Response, length %d", pktlen);
366 
367 		if (pktlen > (actlen - off)) {
368 			CDCEEM_WARN(sc,
369 			    "bad Echo Response length %d, "
370 			    "should be at most %d",
371 			    pktlen, actlen - off);
372 			break;
373 		}
374 
375 		if (pktlen != sizeof(CDCEEM_ECHO_PAYLOAD)) {
376 			CDCEEM_WARN(sc, "received Echo Response with bad "
377 			    "length %hu, should be %zd",
378 			    pktlen, sizeof(CDCEEM_ECHO_PAYLOAD));
379 			break;
380 		}
381 
382 		usbd_copy_out(pc, off, sc->sc_echo_buffer, pktlen);
383 		off += pktlen;
384 
385 		if (memcmp(sc->sc_echo_buffer, CDCEEM_ECHO_PAYLOAD,
386 		    sizeof(CDCEEM_ECHO_PAYLOAD)) != 0) {
387 			CDCEEM_WARN(sc,
388 			    "received Echo Response payload does not match");
389 		} else {
390 			CDCEEM_DEBUG(sc, "received Echo Response is valid");
391 		}
392 		break;
393 
394 	case CDCEEM_CMD_SUSPEND_HINT:
395 		CDCEEM_DEBUG(sc, "received SuspendHint; ignoring");
396 		break;
397 
398 	case CDCEEM_CMD_RESPONSE_HINT:
399 		CDCEEM_DEBUG(sc, "received ResponseHint; ignoring");
400 		break;
401 
402 	case CDCEEM_CMD_RESPONSE_COMPLETE_HINT:
403 		CDCEEM_DEBUG(sc, "received ResponseCompleteHint; ignoring");
404 		break;
405 
406 	case CDCEEM_CMD_TICKLE:
407 		CDCEEM_DEBUG(sc, "received Tickle; ignoring");
408 		break;
409 
410 	default:
411 		CDCEEM_WARN(sc,
412 		    "received unknown command %u, header %#x; ignoring",
413 		    (hdr & CDCEEM_CMD_MASK >> 11), hdr);
414 		break;
415 	}
416 
417 	*offp = off;
418 }
419 
420 static void
421 cdceem_handle_data(struct usb_xfer *xfer, uint16_t hdr, int *offp)
422 {
423 	struct cdceem_softc *sc;
424 	struct usb_page_cache *pc;
425 	struct usb_ether *ue;
426 	if_t ifp;
427 	struct mbuf *m;
428 	uint32_t computed_crc, received_crc;
429 	int pktlen;
430 	int actlen;
431 	int off;
432 
433 	off = *offp;
434 	sc = usbd_xfer_softc(xfer);
435 	pc = usbd_xfer_get_frame(xfer, 0);
436 	ue = &sc->sc_ue;
437 	ifp = uether_getifp(ue);
438 	usbd_xfer_status(xfer, &actlen, NULL, NULL, NULL);
439 
440 	pktlen = hdr & CDCEEM_DATA_LEN_MASK;
441 	CDCEEM_DEBUG(sc, "received Data, CRC %s, length %d",
442 	    (hdr & CDCEEM_DATA_CRC) ? "valid" : "absent",
443 	    pktlen);
444 
445 	if (pktlen < (ETHER_HDR_LEN + 4)) {
446 		CDCEEM_WARN(sc,
447 		    "bad ethernet frame length %d, should be at least %d",
448 		    pktlen, ETHER_HDR_LEN);
449 		if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
450 		return;
451 	}
452 
453 	if (pktlen > (actlen - off)) {
454 		CDCEEM_WARN(sc,
455 		    "bad ethernet frame length %d, should be at most %d",
456 		    pktlen, actlen - off);
457 		if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
458 		return;
459 	}
460 
461 	m = uether_newbuf();
462 	if (m == NULL) {
463 		CDCEEM_WARN(sc, "uether_newbuf() failed");
464 		if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
465 		return;
466 	}
467 
468 	pktlen -= 4; /* Subtract the CRC. */
469 
470 	if (pktlen > m->m_len) {
471 		CDCEEM_WARN(sc, "buffer too small %d vs %d bytes",
472 		    pktlen, m->m_len);
473 		if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
474 		m_freem(m);
475 		return;
476 	}
477 	usbd_copy_out(pc, off, mtod(m, uint8_t *), pktlen);
478 	off += pktlen;
479 
480 	usbd_copy_out(pc, off, &received_crc, sizeof(received_crc));
481 	off += sizeof(received_crc);
482 
483 	if (hdr & CDCEEM_DATA_CRC) {
484 		computed_crc = cdceem_m_crc32(m, 0, pktlen);
485 	} else {
486 		computed_crc = be32toh(0xdeadbeef);
487 	}
488 
489 	if (received_crc != computed_crc) {
490 		CDCEEM_WARN(sc,
491 		    "received Data packet with wrong CRC %#x, expected %#x",
492 		    received_crc, computed_crc);
493 		if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
494 		m_freem(m);
495 		return;
496 	} else {
497 		CDCEEM_DEBUG(sc, "received correct CRC %#x", received_crc);
498 	}
499 
500 	uether_rxmbuf(ue, m, pktlen);
501 	*offp = off;
502 }
503 
504 static void
505 cdceem_bulk_read_callback(struct usb_xfer *xfer, usb_error_t usb_error)
506 {
507 	struct cdceem_softc *sc;
508 	struct usb_page_cache *pc;
509 	int actlen, aframes, off;
510 	uint16_t hdr;
511 
512 	sc = usbd_xfer_softc(xfer);
513 	usbd_xfer_status(xfer, &actlen, NULL, &aframes, NULL);
514 
515 	switch (USB_GET_STATE(xfer)) {
516 	case USB_ST_TRANSFERRED:
517 		CDCEEM_DEBUG(sc,
518 		    "received %u bytes in %u frames", actlen, aframes);
519 
520 		pc = usbd_xfer_get_frame(xfer, 0);
521 		off = 0;
522 
523 		while ((off + sizeof(hdr)) <= actlen) {
524 			usbd_copy_out(pc, off, &hdr, sizeof(hdr));
525 			CDCEEM_DEBUG(sc, "hdr = %#x", hdr);
526 			off += sizeof(hdr);
527 
528 			if (hdr == 0) {
529 				CDCEEM_DEBUG(sc, "received Zero Length EEM");
530 				continue;
531 			}
532 
533 			hdr = le16toh(hdr);
534 
535 			if ((hdr & CDCEEM_TYPE_CMD) != 0) {
536 				cdceem_handle_cmd(xfer, hdr, &off);
537 			} else {
538 				cdceem_handle_data(xfer, hdr, &off);
539 			}
540 
541 			KASSERT(off <= actlen,
542 			    ("%s: went past the buffer, off %d, actlen %d",
543 			     __func__, off, actlen));
544 		}
545 
546 		/* FALLTHROUGH */
547 	case USB_ST_SETUP:
548 		CDCEEM_DEBUG(sc, "setup");
549 tr_setup:
550 		usbd_xfer_set_frame_len(xfer, 0, usbd_xfer_max_len(xfer));
551 		usbd_transfer_submit(xfer);
552 		uether_rxflush(&sc->sc_ue);
553 		break;
554 
555 	default:
556 		CDCEEM_WARN(sc, "USB_ST_ERROR: %s", usbd_errstr(usb_error));
557 
558 		if (usb_error != USB_ERR_CANCELLED) {
559 			/* try to clear stall first */
560 			usbd_xfer_set_stall(xfer);
561 			goto tr_setup;
562 		}
563 		break;
564 	}
565 }
566 
567 static void
568 cdceem_send_echo(struct usb_xfer *xfer, int *offp)
569 {
570 	struct cdceem_softc *sc;
571 	struct usb_page_cache *pc;
572 	int maxlen __diagused, off;
573 	uint16_t hdr;
574 
575 	off = *offp;
576 	sc = usbd_xfer_softc(xfer);
577 	pc = usbd_xfer_get_frame(xfer, 0);
578 	maxlen = usbd_xfer_max_len(xfer);
579 
580 	CDCEEM_DEBUG(sc, "sending Echo, length %zd",
581 	    sizeof(CDCEEM_ECHO_PAYLOAD));
582 
583 	KASSERT(off + sizeof(hdr) + sizeof(CDCEEM_ECHO_PAYLOAD) < maxlen,
584 	    ("%s: out of space; have %d, need %zd", __func__, maxlen,
585 	    off + sizeof(hdr) + sizeof(CDCEEM_ECHO_PAYLOAD)));
586 
587 	hdr = 0;
588 	hdr |= CDCEEM_TYPE_CMD;
589 	hdr |= CDCEEM_CMD_ECHO;
590 	hdr |= sizeof(CDCEEM_ECHO_PAYLOAD);
591 	CDCEEM_DEBUG(sc, "hdr = %#x", hdr);
592 	hdr = htole16(hdr);
593 
594 	usbd_copy_in(pc, off, &hdr, sizeof(hdr));
595 	off += sizeof(hdr);
596 
597 	usbd_copy_in(pc, off, CDCEEM_ECHO_PAYLOAD,
598 	    sizeof(CDCEEM_ECHO_PAYLOAD));
599 	off += sizeof(CDCEEM_ECHO_PAYLOAD);
600 
601 	sc->sc_flags &= ~CDCEEM_SC_FLAGS_ECHO_PENDING;
602 
603 	*offp = off;
604 }
605 
606 static void
607 cdceem_send_echo_response(struct usb_xfer *xfer, int *offp)
608 {
609 	struct cdceem_softc *sc;
610 	struct usb_page_cache *pc;
611 	int maxlen __diagused, off;
612 	uint16_t hdr;
613 
614 	off = *offp;
615 	sc = usbd_xfer_softc(xfer);
616 	pc = usbd_xfer_get_frame(xfer, 0);
617 	maxlen = usbd_xfer_max_len(xfer);
618 
619 	KASSERT(off + sizeof(hdr) + sc->sc_echo_len < maxlen,
620 	    ("%s: out of space; have %d, need %zd", __func__, maxlen,
621 	    off + sizeof(hdr) + sc->sc_echo_len));
622 
623 	CDCEEM_DEBUG(sc, "sending Echo Response, length %zd", sc->sc_echo_len);
624 
625 	hdr = 0;
626 	hdr |= CDCEEM_TYPE_CMD;
627 	hdr |= CDCEEM_CMD_ECHO_RESPONSE;
628 	hdr |= sc->sc_echo_len;
629 	CDCEEM_DEBUG(sc, "hdr = %#x", hdr);
630 	hdr = htole16(hdr);
631 
632 	usbd_copy_in(pc, off, &hdr, sizeof(hdr));
633 	off += sizeof(hdr);
634 
635 	usbd_copy_in(pc, off, sc->sc_echo_buffer, sc->sc_echo_len);
636 	off += sc->sc_echo_len;
637 
638 	sc->sc_flags &= ~CDCEEM_SC_FLAGS_ECHO_RESPONSE_PENDING;
639 	sc->sc_echo_len = 0;
640 
641 	*offp = off;
642 }
643 
644 static void
645 cdceem_send_data(struct usb_xfer *xfer, int *offp)
646 {
647 	struct cdceem_softc *sc;
648 	struct usb_page_cache *pc;
649 	if_t ifp;
650 	struct mbuf *m;
651 	int maxlen __diagused, off;
652 	uint32_t crc;
653 	uint16_t hdr;
654 
655 	off = *offp;
656 	sc = usbd_xfer_softc(xfer);
657 	pc = usbd_xfer_get_frame(xfer, 0);
658 	ifp = uether_getifp(&sc->sc_ue);
659 	maxlen = usbd_xfer_max_len(xfer);
660 
661 	m = if_dequeue(ifp);
662 	if (m == NULL) {
663 		CDCEEM_DEBUG(sc, "no Data packets to send");
664 		return;
665 	}
666 
667 	KASSERT((m->m_pkthdr.len & CDCEEM_DATA_LEN_MASK) == m->m_pkthdr.len,
668 	    ("%s: packet too long: %d, should be %d\n", __func__,
669 	     m->m_pkthdr.len, m->m_pkthdr.len & CDCEEM_DATA_LEN_MASK));
670 	KASSERT(off + sizeof(hdr) + m->m_pkthdr.len + 4 < maxlen,
671 	    ("%s: out of space; have %d, need %zd", __func__, maxlen,
672 	    off + sizeof(hdr) + m->m_pkthdr.len + 4));
673 
674 	CDCEEM_DEBUG(sc, "sending Data, length %d + 4", m->m_pkthdr.len);
675 
676 	hdr = 0;
677 	if (!cdceem_send_fake_crc)
678 		hdr |= CDCEEM_DATA_CRC;
679 	hdr |= (m->m_pkthdr.len + 4); /* +4 for CRC */
680 	CDCEEM_DEBUG(sc, "hdr = %#x", hdr);
681 	hdr = htole16(hdr);
682 
683 	usbd_copy_in(pc, off, &hdr, sizeof(hdr));
684 	off += sizeof(hdr);
685 
686 	usbd_m_copy_in(pc, off, m, 0, m->m_pkthdr.len);
687 	off += m->m_pkthdr.len;
688 
689 	if (cdceem_send_fake_crc) {
690 		crc = htobe32(0xdeadbeef);
691 	} else {
692 		crc = cdceem_m_crc32(m, 0, m->m_pkthdr.len);
693 	}
694 	CDCEEM_DEBUG(sc, "CRC = %#x", crc);
695 
696 	usbd_copy_in(pc, off, &crc, sizeof(crc));
697 	off += sizeof(crc);
698 
699 	if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
700 
701 	/*
702 	 * If there's a BPF listener, bounce a copy of this frame to it.
703 	 */
704 	BPF_MTAP(ifp, m);
705 	m_freem(m);
706 
707 	*offp = off;
708 }
709 
710 static void
711 cdceem_bulk_write_callback(struct usb_xfer *xfer, usb_error_t usb_error)
712 {
713 	struct cdceem_softc *sc;
714 	if_t ifp;
715 	int actlen, aframes, maxlen __diagused, off;
716 
717 	sc = usbd_xfer_softc(xfer);
718 	maxlen = usbd_xfer_max_len(xfer);
719 
720 	switch (USB_GET_STATE(xfer)) {
721 	case USB_ST_TRANSFERRED:
722 		usbd_xfer_status(xfer, &actlen, NULL, &aframes, NULL);
723 		CDCEEM_DEBUG(sc, "transferred %u bytes in %u frames",
724 		    actlen, aframes);
725 
726 		/* FALLTHROUGH */
727 	case USB_ST_SETUP:
728 		CDCEEM_DEBUG(sc, "setup");
729 tr_setup:
730 
731 		off = 0;
732 		usbd_xfer_set_frame_offset(xfer, 0, 0);
733 
734 		if (sc->sc_flags & CDCEEM_SC_FLAGS_ECHO_PENDING) {
735 			cdceem_send_echo(xfer, &off);
736 		} else if (sc->sc_flags & CDCEEM_SC_FLAGS_ECHO_RESPONSE_PENDING) {
737 			cdceem_send_echo_response(xfer, &off);
738 		} else {
739 			cdceem_send_data(xfer, &off);
740 		}
741 
742 		KASSERT(off <= maxlen,
743 		    ("%s: went past the buffer, off %d, maxlen %d",
744 		     __func__, off, maxlen));
745 
746 		if (off > 0) {
747 			CDCEEM_DEBUG(sc, "starting transfer, length %d", off);
748 			usbd_xfer_set_frame_len(xfer, 0, off);
749 			usbd_transfer_submit(xfer);
750 		} else {
751 			CDCEEM_DEBUG(sc, "nothing to transfer");
752 		}
753 
754 		break;
755 
756 	default:
757 		CDCEEM_WARN(sc, "USB_ST_ERROR: %s", usbd_errstr(usb_error));
758 
759 		ifp = uether_getifp(&sc->sc_ue);
760 		if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
761 
762 		if (usb_error != USB_ERR_CANCELLED) {
763 			/* try to clear stall first */
764 			usbd_xfer_set_stall(xfer);
765 			goto tr_setup;
766 		}
767 		break;
768 	}
769 }
770 
771 static int32_t
772 cdceem_m_crc32_cb(void *arg, void *src, uint32_t count)
773 {
774 	uint32_t *p_crc = arg;
775 
776 	*p_crc = crc32_raw(src, count, *p_crc);
777 	return (0);
778 }
779 
780 static uint32_t
781 cdceem_m_crc32(struct mbuf *m, uint32_t src_offset, uint32_t src_len)
782 {
783 	uint32_t crc = 0xFFFFFFFF;
784 
785 	m_apply(m, src_offset, src_len, cdceem_m_crc32_cb, &crc);
786 	return (crc ^ 0xFFFFFFFF);
787 }
788 
789 static void
790 cdceem_start(struct usb_ether *ue)
791 {
792 	struct cdceem_softc *sc;
793 
794 	sc = uether_getsc(ue);
795 
796 	/*
797 	 * Start the USB transfers, if not already started.
798 	 */
799 	usbd_transfer_start(sc->sc_xfer[CDCEEM_BULK_RX]);
800 	usbd_transfer_start(sc->sc_xfer[CDCEEM_BULK_TX]);
801 }
802 
803 static void
804 cdceem_init(struct usb_ether *ue)
805 {
806 	struct cdceem_softc *sc;
807 	if_t ifp;
808 
809 	sc = uether_getsc(ue);
810 	ifp = uether_getifp(ue);
811 
812 	if_setdrvflagbits(ifp, IFF_DRV_RUNNING, 0);
813 
814 	if (cdceem_send_echoes)
815 		sc->sc_flags = CDCEEM_SC_FLAGS_ECHO_PENDING;
816 	else
817 		sc->sc_flags = 0;
818 
819 	/*
820 	 * Stall data write direction, which depends on USB mode.
821 	 *
822 	 * Some USB host stacks (e.g. Mac OS X) don't clears stall
823 	 * bit as it should, so set it in our host mode only.
824 	 */
825 	if (usbd_get_mode(sc->sc_ue.ue_udev) == USB_MODE_HOST)
826 		usbd_xfer_set_stall(sc->sc_xfer[CDCEEM_BULK_TX]);
827 
828 	cdceem_start(ue);
829 }
830 
831 static void
832 cdceem_stop(struct usb_ether *ue)
833 {
834 	struct cdceem_softc *sc;
835 	if_t ifp;
836 
837 	sc = uether_getsc(ue);
838 	ifp = uether_getifp(ue);
839 
840 	if_setdrvflagbits(ifp, 0, IFF_DRV_RUNNING);
841 
842 	usbd_transfer_stop(sc->sc_xfer[CDCEEM_BULK_RX]);
843 	usbd_transfer_stop(sc->sc_xfer[CDCEEM_BULK_TX]);
844 }
845 
846 static void
847 cdceem_setmulti(struct usb_ether *ue)
848 {
849 	/* no-op */
850 	return;
851 }
852 
853 static void
854 cdceem_setpromisc(struct usb_ether *ue)
855 {
856 	/* no-op */
857 	return;
858 }
859 
860 static int
861 cdceem_suspend(device_t dev)
862 {
863 	struct cdceem_softc *sc = device_get_softc(dev);
864 
865 	CDCEEM_DEBUG(sc, "go");
866 	return (0);
867 }
868 
869 static int
870 cdceem_resume(device_t dev)
871 {
872 	struct cdceem_softc *sc = device_get_softc(dev);
873 
874 	CDCEEM_DEBUG(sc, "go");
875 	return (0);
876 }
877