xref: /freebsd/sys/dev/usb/net/if_ipheth.c (revision c992ac6213276f54d868f317cc5092f8aed4ff54)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2010 Hans Petter Selasky. All rights reserved.
5  * Copyright (c) 2009 Diego Giagio. All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 /*
30  * Thanks to Diego Giagio for figuring out the programming details for
31  * the Apple iPhone Ethernet driver.
32  */
33 
34 #include <sys/stdint.h>
35 #include <sys/stddef.h>
36 #include <sys/param.h>
37 #include <sys/queue.h>
38 #include <sys/types.h>
39 #include <sys/systm.h>
40 #include <sys/kernel.h>
41 #include <sys/bus.h>
42 #include <sys/module.h>
43 #include <sys/lock.h>
44 #include <sys/mutex.h>
45 #include <sys/condvar.h>
46 #include <sys/socket.h>
47 #include <sys/sysctl.h>
48 #include <sys/sx.h>
49 #include <sys/unistd.h>
50 #include <sys/callout.h>
51 #include <sys/malloc.h>
52 #include <sys/priv.h>
53 
54 #include <net/if.h>
55 #include <net/if_var.h>
56 
57 #include <dev/usb/usb.h>
58 #include <dev/usb/usb_cdc.h>
59 #include <dev/usb/usbdi.h>
60 #include <dev/usb/usbdi_util.h>
61 #include "usbdevs.h"
62 
63 #define	USB_DEBUG_VAR ipheth_debug
64 #include <dev/usb/usb_debug.h>
65 #include <dev/usb/usb_process.h>
66 
67 #include <dev/usb/net/usb_ethernet.h>
68 #include <dev/usb/net/if_iphethvar.h>
69 
70 static device_probe_t ipheth_probe;
71 static device_attach_t ipheth_attach;
72 static device_detach_t ipheth_detach;
73 
74 static usb_callback_t ipheth_bulk_write_callback;
75 static usb_callback_t ipheth_bulk_read_callback;
76 
77 static uether_fn_t ipheth_attach_post;
78 static uether_fn_t ipheth_tick;
79 static uether_fn_t ipheth_init;
80 static uether_fn_t ipheth_stop;
81 static uether_fn_t ipheth_start;
82 static uether_fn_t ipheth_setmulti;
83 static uether_fn_t ipheth_setpromisc;
84 
85 static ipheth_consumer_t ipheth_consume_read;
86 static ipheth_consumer_t ipheth_consume_read_ncm;
87 
88 #ifdef USB_DEBUG
89 static int ipheth_debug = 0;
90 
91 static SYSCTL_NODE(_hw_usb, OID_AUTO, ipheth, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
92     "USB iPhone ethernet");
93 SYSCTL_INT(_hw_usb_ipheth, OID_AUTO, debug, CTLFLAG_RWTUN, &ipheth_debug, 0, "Debug level");
94 #endif
95 
96 static const struct usb_config ipheth_config[IPHETH_N_TRANSFER] = {
97 	[IPHETH_BULK_RX] = {
98 		.type = UE_BULK,
99 		.endpoint = UE_ADDR_ANY,
100 		.direction = UE_DIR_RX,
101 		.frames = IPHETH_RX_FRAMES_MAX,
102 		.bufsize = (IPHETH_RX_FRAMES_MAX * MCLBYTES),
103 		.flags = {.short_frames_ok = 1, .short_xfer_ok = 1, .ext_buffer = 1,},
104 		.callback = ipheth_bulk_read_callback,
105 		.timeout = 0,		/* no timeout */
106 	},
107 
108 	[IPHETH_BULK_TX] = {
109 		.type = UE_BULK,
110 		.endpoint = UE_ADDR_ANY,
111 		.direction = UE_DIR_TX,
112 		.frames = IPHETH_TX_FRAMES_MAX,
113 		.bufsize = (IPHETH_TX_FRAMES_MAX * IPHETH_BUF_SIZE),
114 		.flags = {.force_short_xfer = 1,},
115 		.callback = ipheth_bulk_write_callback,
116 		.timeout = IPHETH_TX_TIMEOUT,
117 	},
118 };
119 
120 static const struct usb_config ipheth_config_ncm[IPHETH_N_TRANSFER] = {
121 	[IPHETH_BULK_RX] = {
122 		.type = UE_BULK,
123 		.endpoint = UE_ADDR_ANY,
124 		.direction = UE_DIR_RX,
125 		.frames = 1,
126 		.bufsize = IPHETH_RX_NCM_BUF_SIZE,
127 		.flags = {.short_frames_ok = 1, .short_xfer_ok = 1,},
128 		.callback = ipheth_bulk_read_callback,
129 		.timeout = 0,		/* no timeout */
130 	},
131 
132 	[IPHETH_BULK_TX] = {
133 		.type = UE_BULK,
134 		.endpoint = UE_ADDR_ANY,
135 		.direction = UE_DIR_TX,
136 		.frames = IPHETH_TX_FRAMES_MAX,
137 		.bufsize = (IPHETH_TX_FRAMES_MAX * IPHETH_BUF_SIZE),
138 		.flags = {.force_short_xfer = 1,},
139 		.callback = ipheth_bulk_write_callback,
140 		.timeout = IPHETH_TX_TIMEOUT,
141 	},
142 };
143 
144 static device_method_t ipheth_methods[] = {
145 	/* Device interface */
146 	DEVMETHOD(device_probe, ipheth_probe),
147 	DEVMETHOD(device_attach, ipheth_attach),
148 	DEVMETHOD(device_detach, ipheth_detach),
149 
150 	DEVMETHOD_END
151 };
152 
153 static driver_t ipheth_driver = {
154 	.name = "ipheth",
155 	.methods = ipheth_methods,
156 	.size = sizeof(struct ipheth_softc),
157 };
158 
159 static const STRUCT_USB_HOST_ID ipheth_devs[] = {
160 #if 0
161 	{IPHETH_ID(USB_VENDOR_APPLE, USB_PRODUCT_APPLE_IPHONE,
162 	    IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
163 	    IPHETH_USBINTF_PROTO)},
164 	{IPHETH_ID(USB_VENDOR_APPLE, USB_PRODUCT_APPLE_IPHONE_3G,
165 	    IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
166 	    IPHETH_USBINTF_PROTO)},
167 	{IPHETH_ID(USB_VENDOR_APPLE, USB_PRODUCT_APPLE_IPHONE_3GS,
168 	    IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
169 	    IPHETH_USBINTF_PROTO)},
170 	{IPHETH_ID(USB_VENDOR_APPLE, USB_PRODUCT_APPLE_IPHONE_4,
171 	    IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
172 	    IPHETH_USBINTF_PROTO)},
173 	{IPHETH_ID(USB_VENDOR_APPLE, USB_PRODUCT_APPLE_IPHONE_4S,
174 	    IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
175 	    IPHETH_USBINTF_PROTO)},
176 	{IPHETH_ID(USB_VENDOR_APPLE, USB_PRODUCT_APPLE_IPHONE_5,
177 	    IPHETH_USBINTF_CLASS, IPHETH_USBINTF_SUBCLASS,
178 	    IPHETH_USBINTF_PROTO)},
179 #else
180 	/* product agnostic interface match */
181 	{USB_VENDOR(USB_VENDOR_APPLE),
182 	 USB_IFACE_CLASS(IPHETH_USBINTF_CLASS),
183 	 USB_IFACE_SUBCLASS(IPHETH_USBINTF_SUBCLASS),
184 	 USB_IFACE_PROTOCOL(IPHETH_USBINTF_PROTO)},
185 #endif
186 };
187 
188 DRIVER_MODULE(ipheth, uhub, ipheth_driver, NULL, NULL);
189 MODULE_VERSION(ipheth, 1);
190 MODULE_DEPEND(ipheth, uether, 1, 1, 1);
191 MODULE_DEPEND(ipheth, usb, 1, 1, 1);
192 MODULE_DEPEND(ipheth, ether, 1, 1, 1);
193 USB_PNP_HOST_INFO(ipheth_devs);
194 
195 static const struct usb_ether_methods ipheth_ue_methods = {
196 	.ue_attach_post = ipheth_attach_post,
197 	.ue_start = ipheth_start,
198 	.ue_init = ipheth_init,
199 	.ue_tick = ipheth_tick,
200 	.ue_stop = ipheth_stop,
201 	.ue_setmulti = ipheth_setmulti,
202 	.ue_setpromisc = ipheth_setpromisc,
203 };
204 
205 #define	IPHETH_ID(v,p,c,sc,pt) \
206     USB_VENDOR(v), USB_PRODUCT(p), \
207     USB_IFACE_CLASS(c), USB_IFACE_SUBCLASS(sc), \
208     USB_IFACE_PROTOCOL(pt)
209 
210 static int
211 ipheth_get_mac_addr(struct ipheth_softc *sc)
212 {
213 	struct usb_device_request req;
214 	int error;
215 
216 	req.bmRequestType = UT_READ_VENDOR_DEVICE;
217 	req.bRequest = IPHETH_CMD_GET_MACADDR;
218 	req.wValue[0] = 0;
219 	req.wValue[1] = 0;
220 	req.wIndex[0] = sc->sc_iface_no;
221 	req.wIndex[1] = 0;
222 	req.wLength[0] = ETHER_ADDR_LEN;
223 	req.wLength[1] = 0;
224 
225 	error = usbd_do_request(sc->sc_ue.ue_udev, NULL, &req, sc->sc_data);
226 
227 	if (error)
228 		return (error);
229 
230 	memcpy(sc->sc_ue.ue_eaddr, sc->sc_data, ETHER_ADDR_LEN);
231 
232 	return (0);
233 }
234 
235 static bool
236 ipheth_enable_ncm(struct ipheth_softc *sc)
237 {
238 	struct usb_device_request req;
239 
240 	req.bmRequestType = UT_WRITE_VENDOR_INTERFACE;
241 	req.bRequest = IPHETH_CMD_ENABLE_NCM;
242 	USETW(req.wValue, 0);
243 	req.wIndex[0] = sc->sc_iface_no;
244 	req.wIndex[1] = 0;
245 	USETW(req.wLength, 0);
246 
247 	return (usbd_do_request(sc->sc_ue.ue_udev, NULL, &req, NULL) == 0);
248 }
249 
250 static int
251 ipheth_probe(device_t dev)
252 {
253 	struct usb_attach_arg *uaa = device_get_ivars(dev);
254 
255 	if (uaa->usb_mode != USB_MODE_HOST)
256 		return (ENXIO);
257 
258 	return (usbd_lookup_id_by_uaa(ipheth_devs, sizeof(ipheth_devs), uaa));
259 }
260 
261 static int
262 ipheth_attach(device_t dev)
263 {
264 	struct ipheth_softc *sc = device_get_softc(dev);
265 	struct usb_ether *ue = &sc->sc_ue;
266 	struct usb_attach_arg *uaa = device_get_ivars(dev);
267 	const struct usb_config *config;
268 	int error;
269 
270 	sc->sc_iface_no = uaa->info.bIfaceIndex;
271 
272 	device_set_usb_desc(dev);
273 
274 	mtx_init(&sc->sc_mtx, device_get_nameunit(dev), NULL, MTX_DEF);
275 
276 	error = usbd_set_alt_interface_index(uaa->device,
277 	    uaa->info.bIfaceIndex, IPHETH_ALT_INTFNUM);
278 	if (error) {
279 		device_printf(dev, "Cannot set alternate setting\n");
280 		goto detach;
281 	}
282 
283 	ue->ue_sc = sc;
284 	ue->ue_dev = dev;
285 	ue->ue_udev = uaa->device;
286 	ue->ue_mtx = &sc->sc_mtx;
287 	ue->ue_methods = &ipheth_ue_methods;
288 
289 	if (ipheth_enable_ncm(sc)) {
290 		config = ipheth_config_ncm;
291 		sc->is_ncm = true;
292 		sc->consume = &ipheth_consume_read_ncm;
293 	} else {
294 		config = ipheth_config;
295 		sc->consume = &ipheth_consume_read;
296 	}
297 
298 	error = usbd_transfer_setup(uaa->device, &sc->sc_iface_no, sc->sc_xfer,
299 	    config, IPHETH_N_TRANSFER, sc, &sc->sc_mtx);
300 	if (error) {
301 		device_printf(dev, "Cannot setup USB transfers\n");
302 		goto detach;
303 	}
304 
305 	error = ipheth_get_mac_addr(sc);
306 	if (error) {
307 		device_printf(dev, "Cannot get MAC address\n");
308 		goto detach;
309 	}
310 
311 	error = uether_ifattach(ue);
312 	if (error) {
313 		device_printf(dev, "could not attach interface\n");
314 		goto detach;
315 	}
316 	return (0);			/* success */
317 
318 detach:
319 	ipheth_detach(dev);
320 	return (ENXIO);			/* failure */
321 }
322 
323 static int
324 ipheth_detach(device_t dev)
325 {
326 	struct ipheth_softc *sc = device_get_softc(dev);
327 	struct usb_ether *ue = &sc->sc_ue;
328 
329 	/* stop all USB transfers first */
330 	usbd_transfer_unsetup(sc->sc_xfer, IPHETH_N_TRANSFER);
331 
332 	uether_ifdetach(ue);
333 
334 	mtx_destroy(&sc->sc_mtx);
335 
336 	return (0);
337 }
338 
339 static void
340 ipheth_start(struct usb_ether *ue)
341 {
342 	struct ipheth_softc *sc = uether_getsc(ue);
343 
344 	/*
345 	 * Start the USB transfers, if not already started:
346 	 */
347 	usbd_transfer_start(sc->sc_xfer[IPHETH_BULK_TX]);
348 	usbd_transfer_start(sc->sc_xfer[IPHETH_BULK_RX]);
349 }
350 
351 static void
352 ipheth_stop(struct usb_ether *ue)
353 {
354 	struct ipheth_softc *sc = uether_getsc(ue);
355 
356 	/*
357 	 * Stop the USB transfers, if not already stopped:
358 	 */
359 	usbd_transfer_stop(sc->sc_xfer[IPHETH_BULK_TX]);
360 	usbd_transfer_stop(sc->sc_xfer[IPHETH_BULK_RX]);
361 }
362 
363 static void
364 ipheth_tick(struct usb_ether *ue)
365 {
366 	struct ipheth_softc *sc = uether_getsc(ue);
367 	struct usb_device_request req;
368 	int error;
369 
370 	req.bmRequestType = UT_READ_VENDOR_DEVICE;
371 	req.bRequest = IPHETH_CMD_CARRIER_CHECK;
372 	req.wValue[0] = 0;
373 	req.wValue[1] = 0;
374 	req.wIndex[0] = sc->sc_iface_no;
375 	req.wIndex[1] = 0;
376 	req.wLength[0] = IPHETH_CTRL_BUF_SIZE;
377 	req.wLength[1] = 0;
378 
379 	error = uether_do_request(ue, &req, sc->sc_data, IPHETH_CTRL_TIMEOUT);
380 
381 	if (error)
382 		return;
383 
384 	sc->sc_carrier_on =
385 	    (sc->sc_data[0] == IPHETH_CARRIER_ON);
386 }
387 
388 static void
389 ipheth_attach_post(struct usb_ether *ue)
390 {
391 
392 }
393 
394 static void
395 ipheth_init(struct usb_ether *ue)
396 {
397 	struct ipheth_softc *sc = uether_getsc(ue);
398 	if_t ifp = uether_getifp(ue);
399 
400 	IPHETH_LOCK_ASSERT(sc, MA_OWNED);
401 
402 	if_setdrvflagbits(ifp, IFF_DRV_RUNNING, 0);
403 
404 	/* stall data write direction, which depends on USB mode */
405 	usbd_xfer_set_stall(sc->sc_xfer[IPHETH_BULK_TX]);
406 
407 	/* start data transfers */
408 	ipheth_start(ue);
409 }
410 
411 static void
412 ipheth_setmulti(struct usb_ether *ue)
413 {
414 
415 }
416 
417 static void
418 ipheth_setpromisc(struct usb_ether *ue)
419 {
420 
421 }
422 
423 static void
424 ipheth_free_queue(struct mbuf **ppm, uint8_t n)
425 {
426 	uint8_t x;
427 
428 	for (x = 0; x != n; x++) {
429 		if (ppm[x] != NULL) {
430 			m_freem(ppm[x]);
431 			ppm[x] = NULL;
432 		}
433 	}
434 }
435 
436 static void
437 ipheth_bulk_write_callback(struct usb_xfer *xfer, usb_error_t error)
438 {
439 	struct ipheth_softc *sc = usbd_xfer_softc(xfer);
440 	if_t ifp = uether_getifp(&sc->sc_ue);
441 	struct usb_page_cache *pc;
442 	struct mbuf *m;
443 	uint8_t x;
444 	int actlen;
445 	int aframes;
446 
447 	switch (USB_GET_STATE(xfer)) {
448 	case USB_ST_TRANSFERRED:
449 		usbd_xfer_status(xfer, &actlen, NULL, &aframes, NULL);
450 		DPRINTFN(11, "transfer complete: %u bytes in %u frames\n",
451 		    actlen, aframes);
452 
453 		if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
454 
455 		/* free all previous TX buffers */
456 		ipheth_free_queue(sc->sc_tx_buf, IPHETH_TX_FRAMES_MAX);
457 
458 		/* FALLTHROUGH */
459 	case USB_ST_SETUP:
460 tr_setup:
461 		for (x = 0; x != IPHETH_TX_FRAMES_MAX; x++) {
462 			m = if_dequeue(ifp);
463 
464 			if (m == NULL)
465 				break;
466 
467 			usbd_xfer_set_frame_offset(xfer,
468 			    x * IPHETH_BUF_SIZE, x);
469 
470 			pc = usbd_xfer_get_frame(xfer, x);
471 
472 			sc->sc_tx_buf[x] = m;
473 
474 			if (m->m_pkthdr.len > IPHETH_BUF_SIZE)
475 				m->m_pkthdr.len = IPHETH_BUF_SIZE;
476 
477 			usbd_m_copy_in(pc, 0, m, 0, m->m_pkthdr.len);
478 
479 			usbd_xfer_set_frame_len(xfer, x, IPHETH_BUF_SIZE);
480 
481 			if (IPHETH_BUF_SIZE != m->m_pkthdr.len) {
482 				usbd_frame_zero(pc, m->m_pkthdr.len,
483 					IPHETH_BUF_SIZE - m->m_pkthdr.len);
484 			}
485 
486 			/*
487 			 * If there's a BPF listener, bounce a copy of
488 			 * this frame to him:
489 			 */
490 			BPF_MTAP(ifp, m);
491 		}
492 		if (x != 0) {
493 			usbd_xfer_set_frames(xfer, x);
494 
495 			usbd_transfer_submit(xfer);
496 		}
497 		break;
498 
499 	default:			/* Error */
500 		DPRINTFN(11, "transfer error, %s\n",
501 		    usbd_errstr(error));
502 
503 		/* free all previous TX buffers */
504 		ipheth_free_queue(sc->sc_tx_buf, IPHETH_TX_FRAMES_MAX);
505 
506 		/* count output errors */
507 		if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
508 
509 		if (error != USB_ERR_CANCELLED) {
510 			/* try to clear stall first */
511 			usbd_xfer_set_stall(xfer);
512 			goto tr_setup;
513 		}
514 		break;
515 	}
516 }
517 
518 static void
519 ipheth_bulk_read_callback(struct usb_xfer *xfer, usb_error_t error)
520 {
521 	struct ipheth_softc *sc = usbd_xfer_softc(xfer);
522 	struct mbuf *m;
523 	uint8_t x;
524 	int actlen;
525 	int aframes;
526 
527 	switch (USB_GET_STATE(xfer)) {
528 	case USB_ST_TRANSFERRED:
529 		usbd_xfer_status(xfer, &actlen, NULL, &aframes, NULL);
530 		DPRINTF("received %u bytes in %u frames\n", actlen, aframes);
531 
532 		for (x = 0; x != aframes; x++)
533 			sc->consume(xfer, x);
534 
535 		/* FALLTHROUGH */
536 	case USB_ST_SETUP:
537 		if (!sc->is_ncm) {
538 			for (x = 0; x != IPHETH_RX_FRAMES_MAX; x++) {
539 				if (sc->sc_rx_buf[x] == NULL) {
540 					m = uether_newbuf();
541 					if (m == NULL)
542 						goto tr_stall;
543 
544 					/* cancel alignment for ethernet */
545 					m_adj(m, ETHER_ALIGN);
546 
547 					sc->sc_rx_buf[x] = m;
548 				} else {
549 					m = sc->sc_rx_buf[x];
550 				}
551 				usbd_xfer_set_frame_data(xfer, x, m->m_data, m->m_len);
552 			}
553 			usbd_xfer_set_frames(xfer, x);
554 		} else {
555 			usbd_xfer_set_frame_len(xfer, 0,
556 			    IPHETH_RX_NCM_BUF_SIZE);
557 			usbd_xfer_set_frames(xfer, 1);
558 		}
559 
560 		usbd_transfer_submit(xfer);
561 		/* flush any received frames */
562 		uether_rxflush(&sc->sc_ue);
563 		break;
564 
565 	default:			/* Error */
566 		DPRINTF("error = %s\n", usbd_errstr(error));
567 
568 		if (error != USB_ERR_CANCELLED) {
569 	tr_stall:
570 			/* try to clear stall first */
571 			usbd_xfer_set_stall(xfer);
572 			usbd_xfer_set_frames(xfer, 0);
573 			usbd_transfer_submit(xfer);
574 			break;
575 		}
576 		/* need to free the RX-mbufs when we are cancelled */
577 		ipheth_free_queue(sc->sc_rx_buf, IPHETH_RX_FRAMES_MAX);
578 		break;
579 	}
580 }
581 
582 static void
583 ipheth_consume_read(struct usb_xfer *xfer, int x)
584 {
585 	struct ipheth_softc *sc = usbd_xfer_softc(xfer);
586 	struct mbuf *m = sc->sc_rx_buf[x];
587 	int len;
588 
589 	sc->sc_rx_buf[x] = NULL;
590 	len = usbd_xfer_frame_len(xfer, x);
591 
592 	if (len < (int)(sizeof(struct ether_header) + IPHETH_RX_ADJ)) {
593 		m_freem(m);
594 		return;
595 	}
596 
597 	m_adj(m, IPHETH_RX_ADJ);
598 
599 	/* queue up mbuf */
600 	uether_rxmbuf(&sc->sc_ue, m, len - IPHETH_RX_ADJ);
601 }
602 
603 static void
604 ipheth_consume_read_ncm(struct usb_xfer *xfer, int x)
605 {
606 	struct ipheth_softc *sc = usbd_xfer_softc(xfer);
607 	struct usb_page_cache *pc = usbd_xfer_get_frame(xfer, 0);
608 	struct ncm_data_cache ncm;
609 	if_t ifp = uether_getifp(&sc->sc_ue);
610 	struct mbuf *new_buf;
611 	int i, actlen;
612 	uint16_t dp_offset, dp_len;
613 
614 	usbd_xfer_status(xfer, &actlen, NULL, NULL, NULL);
615 
616 	if (actlen < IPHETH_NCM_HEADER_SIZE)
617 		return;
618 
619 	usbd_copy_out(pc, 0, &ncm.hdr, sizeof(ncm.hdr));
620 
621 	if (UGETDW(ncm.hdr.dwSignature) != 0x484D434E)
622 		return;
623 
624 	/* Dpt follows the hdr on iOS */
625 	if (UGETW(ncm.hdr.wDptIndex) != (int)(sizeof(struct usb_ncm16_hdr)))
626 		return;
627 
628 	usbd_copy_out(pc, UGETW(ncm.hdr.wDptIndex), &ncm.dpt, sizeof(ncm.dpt));
629 
630 	if (UGETDW(ncm.dpt.dwSignature) != 0x304D434E)
631 		return;
632 
633 	usbd_copy_out(pc, UGETW(ncm.hdr.wDptIndex) + sizeof(ncm.dpt), &ncm.dp,
634 	    sizeof(ncm.dp));
635 
636 	for (i = 0; i < IPHETH_NCM_DPT_DP_NUM; ++i) {
637 		dp_offset = UGETW(ncm.dp[i].wFrameIndex);
638 		dp_len = UGETW(ncm.dp[i].wFrameLength);
639 
640 		/* (3.3.1 USB CDC NCM spec v1.0) */
641 		if (dp_offset == 0 && dp_len == 0)
642 			break;
643 
644 		if (dp_offset < IPHETH_NCM_HEADER_SIZE || dp_offset >= actlen ||
645 		    actlen < (dp_len + dp_offset) ||
646 		    dp_len < sizeof(struct ether_header)) {
647 			if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
648 			continue;
649 		}
650 		if (dp_len > (MCLBYTES - ETHER_ALIGN)) {
651 			if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
652 			continue;
653 		}
654 
655 		new_buf = uether_newbuf();
656 		if (new_buf == NULL) {
657 			if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
658 			continue;
659 		}
660 		usbd_copy_out(pc, dp_offset, new_buf->m_data, dp_len);
661 		uether_rxmbuf(&sc->sc_ue, new_buf, dp_len);
662 	}
663 }
664