xref: /freebsd/sys/dev/usb/net/usb_ethernet.c (revision 2f513db7)
1 /* $FreeBSD$ */
2 /*-
3  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4  *
5  * Copyright (c) 2009 Andrew Thompson (thompsa@FreeBSD.org)
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 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/bus.h>
35 #include <sys/condvar.h>
36 #include <sys/kernel.h>
37 #include <sys/lock.h>
38 #include <sys/malloc.h>
39 #include <sys/mbuf.h>
40 #include <sys/module.h>
41 #include <sys/mutex.h>
42 #include <sys/socket.h>
43 #include <sys/sockio.h>
44 #include <sys/sysctl.h>
45 #include <sys/sx.h>
46 
47 #include <net/if.h>
48 #include <net/if_var.h>
49 #include <net/ethernet.h>
50 #include <net/if_types.h>
51 #include <net/if_media.h>
52 #include <net/if_vlan_var.h>
53 
54 #include <dev/mii/mii.h>
55 #include <dev/mii/miivar.h>
56 
57 #include <dev/usb/usb.h>
58 #include <dev/usb/usbdi.h>
59 
60 #include <dev/usb/usb_process.h>
61 #include <dev/usb/net/usb_ethernet.h>
62 
63 static SYSCTL_NODE(_net, OID_AUTO, ue, CTLFLAG_RD, 0,
64     "USB Ethernet parameters");
65 
66 #define	UE_LOCK(_ue)		mtx_lock((_ue)->ue_mtx)
67 #define	UE_UNLOCK(_ue)		mtx_unlock((_ue)->ue_mtx)
68 #define	UE_LOCK_ASSERT(_ue, t)	mtx_assert((_ue)->ue_mtx, t)
69 
70 MODULE_DEPEND(uether, usb, 1, 1, 1);
71 MODULE_DEPEND(uether, miibus, 1, 1, 1);
72 
73 static struct unrhdr *ueunit;
74 
75 static usb_proc_callback_t ue_attach_post_task;
76 static usb_proc_callback_t ue_promisc_task;
77 static usb_proc_callback_t ue_setmulti_task;
78 static usb_proc_callback_t ue_ifmedia_task;
79 static usb_proc_callback_t ue_tick_task;
80 static usb_proc_callback_t ue_start_task;
81 static usb_proc_callback_t ue_stop_task;
82 
83 static void	ue_init(void *);
84 static void	ue_start(struct ifnet *);
85 static int	ue_ifmedia_upd(struct ifnet *);
86 static void	ue_watchdog(void *);
87 
88 /*
89  * Return values:
90  *    0: success
91  * Else: device has been detached
92  */
93 uint8_t
94 uether_pause(struct usb_ether *ue, unsigned int _ticks)
95 {
96 	if (usb_proc_is_gone(&ue->ue_tq)) {
97 		/* nothing to do */
98 		return (1);
99 	}
100 	usb_pause_mtx(ue->ue_mtx, _ticks);
101 	return (0);
102 }
103 
104 static void
105 ue_queue_command(struct usb_ether *ue,
106     usb_proc_callback_t *fn,
107     struct usb_proc_msg *t0, struct usb_proc_msg *t1)
108 {
109 	struct usb_ether_cfg_task *task;
110 
111 	UE_LOCK_ASSERT(ue, MA_OWNED);
112 
113 	if (usb_proc_is_gone(&ue->ue_tq)) {
114 		return;         /* nothing to do */
115 	}
116 	/*
117 	 * NOTE: The task cannot get executed before we drop the
118 	 * "sc_mtx" mutex. It is safe to update fields in the message
119 	 * structure after that the message got queued.
120 	 */
121 	task = (struct usb_ether_cfg_task *)
122 	  usb_proc_msignal(&ue->ue_tq, t0, t1);
123 
124 	/* Setup callback and self pointers */
125 	task->hdr.pm_callback = fn;
126 	task->ue = ue;
127 
128 	/*
129 	 * Start and stop must be synchronous!
130 	 */
131 	if ((fn == ue_start_task) || (fn == ue_stop_task))
132 		usb_proc_mwait(&ue->ue_tq, t0, t1);
133 }
134 
135 struct ifnet *
136 uether_getifp(struct usb_ether *ue)
137 {
138 	return (ue->ue_ifp);
139 }
140 
141 struct mii_data *
142 uether_getmii(struct usb_ether *ue)
143 {
144 	return (device_get_softc(ue->ue_miibus));
145 }
146 
147 void *
148 uether_getsc(struct usb_ether *ue)
149 {
150 	return (ue->ue_sc);
151 }
152 
153 static int
154 ue_sysctl_parent(SYSCTL_HANDLER_ARGS)
155 {
156 	struct usb_ether *ue = arg1;
157 	const char *name;
158 
159 	name = device_get_nameunit(ue->ue_dev);
160 	return SYSCTL_OUT_STR(req, name);
161 }
162 
163 int
164 uether_ifattach(struct usb_ether *ue)
165 {
166 	int error;
167 
168 	/* check some critical parameters */
169 	if ((ue->ue_dev == NULL) ||
170 	    (ue->ue_udev == NULL) ||
171 	    (ue->ue_mtx == NULL) ||
172 	    (ue->ue_methods == NULL))
173 		return (EINVAL);
174 
175 	error = usb_proc_create(&ue->ue_tq, ue->ue_mtx,
176 	    device_get_nameunit(ue->ue_dev), USB_PRI_MED);
177 	if (error) {
178 		device_printf(ue->ue_dev, "could not setup taskqueue\n");
179 		goto error;
180 	}
181 
182 	/* fork rest of the attach code */
183 	UE_LOCK(ue);
184 	ue_queue_command(ue, ue_attach_post_task,
185 	    &ue->ue_sync_task[0].hdr,
186 	    &ue->ue_sync_task[1].hdr);
187 	UE_UNLOCK(ue);
188 
189 error:
190 	return (error);
191 }
192 
193 void
194 uether_ifattach_wait(struct usb_ether *ue)
195 {
196 
197 	UE_LOCK(ue);
198 	usb_proc_mwait(&ue->ue_tq,
199 	    &ue->ue_sync_task[0].hdr,
200 	    &ue->ue_sync_task[1].hdr);
201 	UE_UNLOCK(ue);
202 }
203 
204 static void
205 ue_attach_post_task(struct usb_proc_msg *_task)
206 {
207 	struct usb_ether_cfg_task *task =
208 	    (struct usb_ether_cfg_task *)_task;
209 	struct usb_ether *ue = task->ue;
210 	struct ifnet *ifp;
211 	int error;
212 	char num[14];			/* sufficient for 32 bits */
213 
214 	/* first call driver's post attach routine */
215 	ue->ue_methods->ue_attach_post(ue);
216 
217 	UE_UNLOCK(ue);
218 
219 	ue->ue_unit = alloc_unr(ueunit);
220 	usb_callout_init_mtx(&ue->ue_watchdog, ue->ue_mtx, 0);
221 	sysctl_ctx_init(&ue->ue_sysctl_ctx);
222 	mbufq_init(&ue->ue_rxq, 0 /* unlimited length */);
223 
224 	error = 0;
225 	CURVNET_SET_QUIET(vnet0);
226 	ifp = if_alloc(IFT_ETHER);
227 	if (ifp == NULL) {
228 		device_printf(ue->ue_dev, "could not allocate ifnet\n");
229 		goto fail;
230 	}
231 
232 	ifp->if_softc = ue;
233 	if_initname(ifp, "ue", ue->ue_unit);
234 	if (ue->ue_methods->ue_attach_post_sub != NULL) {
235 		ue->ue_ifp = ifp;
236 		error = ue->ue_methods->ue_attach_post_sub(ue);
237 	} else {
238 		ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
239 		if (ue->ue_methods->ue_ioctl != NULL)
240 			ifp->if_ioctl = ue->ue_methods->ue_ioctl;
241 		else
242 			ifp->if_ioctl = uether_ioctl;
243 		ifp->if_start = ue_start;
244 		ifp->if_init = ue_init;
245 		IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
246 		ifp->if_snd.ifq_drv_maxlen = ifqmaxlen;
247 		IFQ_SET_READY(&ifp->if_snd);
248 		ue->ue_ifp = ifp;
249 
250 		if (ue->ue_methods->ue_mii_upd != NULL &&
251 		    ue->ue_methods->ue_mii_sts != NULL) {
252 			/* device_xxx() depends on this */
253 			mtx_lock(&Giant);
254 			error = mii_attach(ue->ue_dev, &ue->ue_miibus, ifp,
255 			    ue_ifmedia_upd, ue->ue_methods->ue_mii_sts,
256 			    BMSR_DEFCAPMASK, MII_PHY_ANY, MII_OFFSET_ANY, 0);
257 			mtx_unlock(&Giant);
258 		}
259 	}
260 
261 	if (error) {
262 		device_printf(ue->ue_dev, "attaching PHYs failed\n");
263 		goto fail;
264 	}
265 
266 	if_printf(ifp, "<USB Ethernet> on %s\n", device_get_nameunit(ue->ue_dev));
267 	ether_ifattach(ifp, ue->ue_eaddr);
268 	/* Tell upper layer we support VLAN oversized frames. */
269 	if (ifp->if_capabilities & IFCAP_VLAN_MTU)
270 		ifp->if_hdrlen = sizeof(struct ether_vlan_header);
271 
272 	CURVNET_RESTORE();
273 
274 	snprintf(num, sizeof(num), "%u", ue->ue_unit);
275 	ue->ue_sysctl_oid = SYSCTL_ADD_NODE(&ue->ue_sysctl_ctx,
276 	    &SYSCTL_NODE_CHILDREN(_net, ue),
277 	    OID_AUTO, num, CTLFLAG_RD, NULL, "");
278 	SYSCTL_ADD_PROC(&ue->ue_sysctl_ctx,
279 	    SYSCTL_CHILDREN(ue->ue_sysctl_oid), OID_AUTO,
280 	    "%parent", CTLTYPE_STRING | CTLFLAG_RD, ue, 0,
281 	    ue_sysctl_parent, "A", "parent device");
282 
283 	UE_LOCK(ue);
284 	return;
285 
286 fail:
287 	CURVNET_RESTORE();
288 
289 	/* drain mbuf queue */
290 	mbufq_drain(&ue->ue_rxq);
291 
292 	/* free unit */
293 	free_unr(ueunit, ue->ue_unit);
294 	if (ue->ue_ifp != NULL) {
295 		if_free(ue->ue_ifp);
296 		ue->ue_ifp = NULL;
297 	}
298 	UE_LOCK(ue);
299 	return;
300 }
301 
302 void
303 uether_ifdetach(struct usb_ether *ue)
304 {
305 	struct ifnet *ifp;
306 
307 	/* wait for any post attach or other command to complete */
308 	usb_proc_drain(&ue->ue_tq);
309 
310 	/* read "ifnet" pointer after taskqueue drain */
311 	ifp = ue->ue_ifp;
312 
313 	if (ifp != NULL) {
314 
315 		/* we are not running any more */
316 		UE_LOCK(ue);
317 		ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
318 		UE_UNLOCK(ue);
319 
320 		/* drain any callouts */
321 		usb_callout_drain(&ue->ue_watchdog);
322 
323 		/* detach miibus */
324 		if (ue->ue_miibus != NULL) {
325 			mtx_lock(&Giant);	/* device_xxx() depends on this */
326 			device_delete_child(ue->ue_dev, ue->ue_miibus);
327 			mtx_unlock(&Giant);
328 		}
329 
330 		/* detach ethernet */
331 		ether_ifdetach(ifp);
332 
333 		/* free interface instance */
334 		if_free(ifp);
335 
336 		/* free sysctl */
337 		sysctl_ctx_free(&ue->ue_sysctl_ctx);
338 
339 		/* drain mbuf queue */
340 		mbufq_drain(&ue->ue_rxq);
341 
342 		/* free unit */
343 		free_unr(ueunit, ue->ue_unit);
344 	}
345 
346 	/* free taskqueue, if any */
347 	usb_proc_free(&ue->ue_tq);
348 }
349 
350 uint8_t
351 uether_is_gone(struct usb_ether *ue)
352 {
353 	return (usb_proc_is_gone(&ue->ue_tq));
354 }
355 
356 void
357 uether_init(void *arg)
358 {
359 
360 	ue_init(arg);
361 }
362 
363 static void
364 ue_init(void *arg)
365 {
366 	struct usb_ether *ue = arg;
367 
368 	UE_LOCK(ue);
369 	ue_queue_command(ue, ue_start_task,
370 	    &ue->ue_sync_task[0].hdr,
371 	    &ue->ue_sync_task[1].hdr);
372 	UE_UNLOCK(ue);
373 }
374 
375 static void
376 ue_start_task(struct usb_proc_msg *_task)
377 {
378 	struct usb_ether_cfg_task *task =
379 	    (struct usb_ether_cfg_task *)_task;
380 	struct usb_ether *ue = task->ue;
381 	struct ifnet *ifp = ue->ue_ifp;
382 
383 	UE_LOCK_ASSERT(ue, MA_OWNED);
384 
385 	ue->ue_methods->ue_init(ue);
386 
387 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0)
388 		return;
389 
390 	if (ue->ue_methods->ue_tick != NULL)
391 		usb_callout_reset(&ue->ue_watchdog, hz, ue_watchdog, ue);
392 }
393 
394 static void
395 ue_stop_task(struct usb_proc_msg *_task)
396 {
397 	struct usb_ether_cfg_task *task =
398 	    (struct usb_ether_cfg_task *)_task;
399 	struct usb_ether *ue = task->ue;
400 
401 	UE_LOCK_ASSERT(ue, MA_OWNED);
402 
403 	usb_callout_stop(&ue->ue_watchdog);
404 
405 	ue->ue_methods->ue_stop(ue);
406 }
407 
408 void
409 uether_start(struct ifnet *ifp)
410 {
411 
412 	ue_start(ifp);
413 }
414 
415 static void
416 ue_start(struct ifnet *ifp)
417 {
418 	struct usb_ether *ue = ifp->if_softc;
419 
420 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0)
421 		return;
422 
423 	UE_LOCK(ue);
424 	ue->ue_methods->ue_start(ue);
425 	UE_UNLOCK(ue);
426 }
427 
428 static void
429 ue_promisc_task(struct usb_proc_msg *_task)
430 {
431 	struct usb_ether_cfg_task *task =
432 	    (struct usb_ether_cfg_task *)_task;
433 	struct usb_ether *ue = task->ue;
434 
435 	ue->ue_methods->ue_setpromisc(ue);
436 }
437 
438 static void
439 ue_setmulti_task(struct usb_proc_msg *_task)
440 {
441 	struct usb_ether_cfg_task *task =
442 	    (struct usb_ether_cfg_task *)_task;
443 	struct usb_ether *ue = task->ue;
444 
445 	ue->ue_methods->ue_setmulti(ue);
446 }
447 
448 int
449 uether_ifmedia_upd(struct ifnet *ifp)
450 {
451 
452 	return (ue_ifmedia_upd(ifp));
453 }
454 
455 static int
456 ue_ifmedia_upd(struct ifnet *ifp)
457 {
458 	struct usb_ether *ue = ifp->if_softc;
459 
460 	/* Defer to process context */
461 	UE_LOCK(ue);
462 	ue_queue_command(ue, ue_ifmedia_task,
463 	    &ue->ue_media_task[0].hdr,
464 	    &ue->ue_media_task[1].hdr);
465 	UE_UNLOCK(ue);
466 
467 	return (0);
468 }
469 
470 static void
471 ue_ifmedia_task(struct usb_proc_msg *_task)
472 {
473 	struct usb_ether_cfg_task *task =
474 	    (struct usb_ether_cfg_task *)_task;
475 	struct usb_ether *ue = task->ue;
476 	struct ifnet *ifp = ue->ue_ifp;
477 
478 	ue->ue_methods->ue_mii_upd(ifp);
479 }
480 
481 static void
482 ue_watchdog(void *arg)
483 {
484 	struct usb_ether *ue = arg;
485 	struct ifnet *ifp = ue->ue_ifp;
486 
487 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0)
488 		return;
489 
490 	ue_queue_command(ue, ue_tick_task,
491 	    &ue->ue_tick_task[0].hdr,
492 	    &ue->ue_tick_task[1].hdr);
493 
494 	usb_callout_reset(&ue->ue_watchdog, hz, ue_watchdog, ue);
495 }
496 
497 static void
498 ue_tick_task(struct usb_proc_msg *_task)
499 {
500 	struct usb_ether_cfg_task *task =
501 	    (struct usb_ether_cfg_task *)_task;
502 	struct usb_ether *ue = task->ue;
503 	struct ifnet *ifp = ue->ue_ifp;
504 
505 	if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0)
506 		return;
507 
508 	ue->ue_methods->ue_tick(ue);
509 }
510 
511 int
512 uether_ioctl(struct ifnet *ifp, u_long command, caddr_t data)
513 {
514 	struct usb_ether *ue = ifp->if_softc;
515 	struct ifreq *ifr = (struct ifreq *)data;
516 	struct mii_data *mii;
517 	int error = 0;
518 
519 	switch (command) {
520 	case SIOCSIFFLAGS:
521 		UE_LOCK(ue);
522 		if (ifp->if_flags & IFF_UP) {
523 			if (ifp->if_drv_flags & IFF_DRV_RUNNING)
524 				ue_queue_command(ue, ue_promisc_task,
525 				    &ue->ue_promisc_task[0].hdr,
526 				    &ue->ue_promisc_task[1].hdr);
527 			else
528 				ue_queue_command(ue, ue_start_task,
529 				    &ue->ue_sync_task[0].hdr,
530 				    &ue->ue_sync_task[1].hdr);
531 		} else {
532 			ue_queue_command(ue, ue_stop_task,
533 			    &ue->ue_sync_task[0].hdr,
534 			    &ue->ue_sync_task[1].hdr);
535 		}
536 		UE_UNLOCK(ue);
537 		break;
538 	case SIOCADDMULTI:
539 	case SIOCDELMULTI:
540 		UE_LOCK(ue);
541 		ue_queue_command(ue, ue_setmulti_task,
542 		    &ue->ue_multi_task[0].hdr,
543 		    &ue->ue_multi_task[1].hdr);
544 		UE_UNLOCK(ue);
545 		break;
546 	case SIOCGIFMEDIA:
547 	case SIOCSIFMEDIA:
548 		if (ue->ue_miibus != NULL) {
549 			mii = device_get_softc(ue->ue_miibus);
550 			error = ifmedia_ioctl(ifp, ifr, &mii->mii_media, command);
551 		} else
552 			error = ether_ioctl(ifp, command, data);
553 		break;
554 	default:
555 		error = ether_ioctl(ifp, command, data);
556 		break;
557 	}
558 	return (error);
559 }
560 
561 static int
562 uether_modevent(module_t mod, int type, void *data)
563 {
564 
565 	switch (type) {
566 	case MOD_LOAD:
567 		ueunit = new_unrhdr(0, INT_MAX, NULL);
568 		break;
569 	case MOD_UNLOAD:
570 		break;
571 	default:
572 		return (EOPNOTSUPP);
573 	}
574 	return (0);
575 }
576 static moduledata_t uether_mod = {
577 	"uether",
578 	uether_modevent,
579 	0
580 };
581 
582 struct mbuf *
583 uether_newbuf(void)
584 {
585 	struct mbuf *m_new;
586 
587 	m_new = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
588 	if (m_new == NULL)
589 		return (NULL);
590 	m_new->m_len = m_new->m_pkthdr.len = MCLBYTES;
591 
592 	m_adj(m_new, ETHER_ALIGN);
593 	return (m_new);
594 }
595 
596 int
597 uether_rxmbuf(struct usb_ether *ue, struct mbuf *m,
598     unsigned int len)
599 {
600 	struct ifnet *ifp = ue->ue_ifp;
601 
602 	UE_LOCK_ASSERT(ue, MA_OWNED);
603 
604 	/* finalize mbuf */
605 	if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
606 	m->m_pkthdr.rcvif = ifp;
607 	m->m_pkthdr.len = m->m_len = len;
608 
609 	/* enqueue for later when the lock can be released */
610 	(void)mbufq_enqueue(&ue->ue_rxq, m);
611 	return (0);
612 }
613 
614 int
615 uether_rxbuf(struct usb_ether *ue, struct usb_page_cache *pc,
616     unsigned int offset, unsigned int len)
617 {
618 	struct ifnet *ifp = ue->ue_ifp;
619 	struct mbuf *m;
620 
621 	UE_LOCK_ASSERT(ue, MA_OWNED);
622 
623 	if (len < ETHER_HDR_LEN || len > MCLBYTES - ETHER_ALIGN)
624 		return (1);
625 
626 	m = uether_newbuf();
627 	if (m == NULL) {
628 		if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
629 		return (ENOMEM);
630 	}
631 
632 	usbd_copy_out(pc, offset, mtod(m, uint8_t *), len);
633 
634 	/* finalize mbuf */
635 	if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
636 	m->m_pkthdr.rcvif = ifp;
637 	m->m_pkthdr.len = m->m_len = len;
638 
639 	/* enqueue for later when the lock can be released */
640 	(void)mbufq_enqueue(&ue->ue_rxq, m);
641 	return (0);
642 }
643 
644 void
645 uether_rxflush(struct usb_ether *ue)
646 {
647 	struct ifnet *ifp = ue->ue_ifp;
648 	struct epoch_tracker et;
649 	struct mbuf *m, *n;
650 
651 	UE_LOCK_ASSERT(ue, MA_OWNED);
652 
653 	n = mbufq_flush(&ue->ue_rxq);
654 	UE_UNLOCK(ue);
655 	NET_EPOCH_ENTER(et);
656 	while ((m = n) != NULL) {
657 		n = STAILQ_NEXT(m, m_stailqpkt);
658 		m->m_nextpkt = NULL;
659 		ifp->if_input(ifp, m);
660 	}
661 	NET_EPOCH_EXIT(et);
662 	UE_LOCK(ue);
663 }
664 
665 /*
666  * USB net drivers are run by DRIVER_MODULE() thus SI_SUB_DRIVERS,
667  * SI_ORDER_MIDDLE.  Run uether after that.
668  */
669 DECLARE_MODULE(uether, uether_mod, SI_SUB_DRIVERS, SI_ORDER_ANY);
670 MODULE_VERSION(uether, 1);
671