xref: /netbsd-src/sys/net/if_gre.c (revision c42dbd0ed2e61fe6eda8590caa852ccf34719964)
1 /*	$NetBSD: if_gre.c,v 1.185 2024/02/03 19:05:14 jdolecek Exp $ */
2 
3 /*
4  * Copyright (c) 1998, 2008 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Heiko W.Rupp <hwr@pilhuhn.de>
9  *
10  * IPv6-over-GRE contributed by Gert Doering <gert@greenie.muc.de>
11  *
12  * GRE over UDP/IPv4/IPv6 sockets contributed by David Young <dyoung@NetBSD.org>
13  *
14  * Redistribution and use in source and binary forms, with or without
15  * modification, are permitted provided that the following conditions
16  * are met:
17  * 1. Redistributions of source code must retain the above copyright
18  *    notice, this list of conditions and the following disclaimer.
19  * 2. Redistributions in binary form must reproduce the above copyright
20  *    notice, this list of conditions and the following disclaimer in the
21  *    documentation and/or other materials provided with the distribution.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
24  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
25  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
26  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
27  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
28  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
30  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
31  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
33  * POSSIBILITY OF SUCH DAMAGE.
34  *
35  * This material is based upon work partially supported by NSF
36  * under Contract No. NSF CNS-0626584.
37  */
38 
39 /*
40  * Encapsulate L3 protocols into IP
41  * See RFC 1701 and 1702 for more details.
42  * If_gre is compatible with Cisco GRE tunnels, so you can
43  * have a NetBSD box as the other end of a tunnel interface of a Cisco
44  * router. See gre(4) for more details.
45  */
46 
47 #include <sys/cdefs.h>
48 __KERNEL_RCSID(0, "$NetBSD: if_gre.c,v 1.185 2024/02/03 19:05:14 jdolecek Exp $");
49 
50 #ifdef _KERNEL_OPT
51 #include "opt_atalk.h"
52 #include "opt_gre.h"
53 #include "opt_inet.h"
54 #include "opt_mpls.h"
55 #endif
56 
57 #include <sys/param.h>
58 #include <sys/file.h>
59 #include <sys/filedesc.h>
60 #include <sys/malloc.h>
61 #include <sys/mallocvar.h>
62 #include <sys/mbuf.h>
63 #include <sys/proc.h>
64 #include <sys/domain.h>
65 #include <sys/protosw.h>
66 #include <sys/socket.h>
67 #include <sys/socketvar.h>
68 #include <sys/ioctl.h>
69 #include <sys/queue.h>
70 #include <sys/intr.h>
71 #include <sys/systm.h>
72 #include <sys/sysctl.h>
73 #include <sys/kauth.h>
74 #include <sys/device.h>
75 #include <sys/module.h>
76 
77 #include <sys/kernel.h>
78 #include <sys/mutex.h>
79 #include <sys/condvar.h>
80 #include <sys/kthread.h>
81 
82 #include <sys/cpu.h>
83 
84 #include <net/ethertypes.h>
85 #include <net/if.h>
86 #include <net/if_types.h>
87 #include <net/route.h>
88 #include <sys/device.h>
89 #include <sys/module.h>
90 #include <sys/atomic.h>
91 
92 #include <netinet/in_systm.h>
93 #include <netinet/in.h>
94 #include <netinet/ip.h> /* we always need this for sizeof(struct ip) */
95 
96 #ifdef INET
97 #include <netinet/in_var.h>
98 #include <netinet/ip_var.h>
99 #endif
100 
101 #ifdef INET6
102 #include <netinet6/in6_var.h>
103 #endif
104 
105 #ifdef MPLS
106 #include <netmpls/mpls.h>
107 #include <netmpls/mpls_var.h>
108 #endif
109 
110 #ifdef NETATALK
111 #include <netatalk/at.h>
112 #include <netatalk/at_var.h>
113 #include <netatalk/at_extern.h>
114 #endif
115 
116 #include <sys/time.h>
117 #include <net/bpf.h>
118 
119 #include <net/if_gre.h>
120 
121 #include "ioconf.h"
122 
123 /*
124  * It is not easy to calculate the right value for a GRE MTU.
125  * We leave this task to the admin and use the same default that
126  * other vendors use.
127  */
128 #define GREMTU 1476
129 
130 #ifdef GRE_DEBUG
131 int gre_debug = 0;
132 #define	GRE_DPRINTF(__sc, ...)						\
133 	do {								\
134 		if (__predict_false(gre_debug ||			\
135 		    ((__sc)->sc_if.if_flags & IFF_DEBUG) != 0)) {	\
136 			printf("%s.%d: ", __func__, __LINE__);		\
137 			printf(__VA_ARGS__);				\
138 		}							\
139 	} while (/*CONSTCOND*/0)
140 #else
141 #define	GRE_DPRINTF(__sc, __fmt, ...)	do { } while (/*CONSTCOND*/0)
142 #endif /* GRE_DEBUG */
143 
144 CTASSERT(sizeof(struct gre_h) == 4);
145 
146 int ip_gre_ttl = GRE_TTL;
147 
148 static u_int gre_count;
149 
150 static int gre_clone_create(struct if_clone *, int);
151 static int gre_clone_destroy(struct ifnet *);
152 
153 static struct if_clone gre_cloner =
154     IF_CLONE_INITIALIZER("gre", gre_clone_create, gre_clone_destroy);
155 
156 static int gre_input(struct gre_softc *, struct mbuf *, const struct gre_h *);
157 static bool gre_is_nullconf(const struct gre_soparm *);
158 static int gre_output(struct ifnet *, struct mbuf *,
159 			   const struct sockaddr *, const struct rtentry *);
160 static int gre_ioctl(struct ifnet *, u_long, void *);
161 static int gre_getsockname(struct socket *, struct sockaddr *);
162 static int gre_getpeername(struct socket *, struct sockaddr *);
163 static int gre_getnames(struct socket *, struct lwp *,
164     struct sockaddr_storage *, struct sockaddr_storage *);
165 static void gre_clearconf(struct gre_soparm *, bool);
166 static int gre_soreceive(struct socket *, struct mbuf **);
167 static int gre_sosend(struct socket *, struct mbuf *);
168 static struct socket *gre_reconf(struct gre_softc *, const struct gre_soparm *);
169 
170 static bool gre_fp_send(struct gre_softc *, enum gre_msg, file_t *);
171 static bool gre_fp_recv(struct gre_softc *);
172 static void gre_fp_recvloop(void *);
173 
174 static void
175 gre_bufq_init(struct gre_bufq *bq, size_t len0)
176 {
177 	memset(bq, 0, sizeof(*bq));
178 	bq->bq_q = pcq_create(len0, KM_SLEEP);
179 	KASSERT(bq->bq_q != NULL);
180 }
181 
182 static struct mbuf *
183 gre_bufq_dequeue(struct gre_bufq *bq)
184 {
185 	return pcq_get(bq->bq_q);
186 }
187 
188 static void
189 gre_bufq_purge(struct gre_bufq *bq)
190 {
191 	struct mbuf *m;
192 
193 	while ((m = gre_bufq_dequeue(bq)) != NULL)
194 		m_freem(m);
195 }
196 
197 static void
198 gre_bufq_destroy(struct gre_bufq *bq)
199 {
200 	gre_bufq_purge(bq);
201 	pcq_destroy(bq->bq_q);
202 }
203 
204 static int
205 gre_bufq_enqueue(struct gre_bufq *bq, struct mbuf *m)
206 {
207 	KASSERT(bq->bq_q != NULL);
208 
209 	if (!pcq_put(bq->bq_q, m)) {
210 		bq->bq_drops++;
211 		return ENOBUFS;
212 	}
213 	return 0;
214 }
215 
216 static void
217 greintr(void *arg)
218 {
219 	struct gre_softc *sc = (struct gre_softc *)arg;
220 	struct socket *so = sc->sc_soparm.sp_so;
221 	int rc;
222 	struct mbuf *m;
223 
224 	KASSERT(so != NULL);
225 
226 	sc->sc_send_ev.ev_count++;
227 	GRE_DPRINTF(sc, "enter\n");
228 	while ((m = gre_bufq_dequeue(&sc->sc_snd)) != NULL) {
229 		/* XXX handle ENOBUFS? */
230 		if ((rc = gre_sosend(so, m)) != 0)
231 			GRE_DPRINTF(sc, "gre_sosend failed %d\n", rc);
232 	}
233 }
234 
235 /* Caller must hold sc->sc_mtx. */
236 static void
237 gre_fp_wait(struct gre_softc *sc)
238 {
239 	sc->sc_fp_waiters++;
240 	cv_wait(&sc->sc_fp_condvar, &sc->sc_mtx);
241 	sc->sc_fp_waiters--;
242 }
243 
244 static void
245 gre_evcnt_detach(struct gre_softc *sc)
246 {
247 	evcnt_detach(&sc->sc_recv_ev);
248 	evcnt_detach(&sc->sc_block_ev);
249 	evcnt_detach(&sc->sc_error_ev);
250 	evcnt_detach(&sc->sc_pullup_ev);
251 	evcnt_detach(&sc->sc_unsupp_ev);
252 
253 	evcnt_detach(&sc->sc_send_ev);
254 	evcnt_detach(&sc->sc_oflow_ev);
255 }
256 
257 static void
258 gre_evcnt_attach(struct gre_softc *sc)
259 {
260 	evcnt_attach_dynamic(&sc->sc_recv_ev, EVCNT_TYPE_MISC,
261 	    NULL, sc->sc_if.if_xname, "recv");
262 	evcnt_attach_dynamic(&sc->sc_block_ev, EVCNT_TYPE_MISC,
263 	    &sc->sc_recv_ev, sc->sc_if.if_xname, "would block");
264 	evcnt_attach_dynamic(&sc->sc_error_ev, EVCNT_TYPE_MISC,
265 	    &sc->sc_recv_ev, sc->sc_if.if_xname, "error");
266 	evcnt_attach_dynamic(&sc->sc_pullup_ev, EVCNT_TYPE_MISC,
267 	    &sc->sc_recv_ev, sc->sc_if.if_xname, "pullup failed");
268 	evcnt_attach_dynamic(&sc->sc_unsupp_ev, EVCNT_TYPE_MISC,
269 	    &sc->sc_recv_ev, sc->sc_if.if_xname, "unsupported");
270 
271 	evcnt_attach_dynamic(&sc->sc_send_ev, EVCNT_TYPE_MISC,
272 	    NULL, sc->sc_if.if_xname, "send");
273 	evcnt_attach_dynamic(&sc->sc_oflow_ev, EVCNT_TYPE_MISC,
274 	    &sc->sc_send_ev, sc->sc_if.if_xname, "overflow");
275 }
276 
277 static int
278 gre_clone_create(struct if_clone *ifc, int unit)
279 {
280 	int rc;
281 	struct gre_softc *sc;
282 	struct gre_soparm *sp;
283 	const struct sockaddr *any;
284 
285 	if ((any = sockaddr_any_by_family(AF_INET)) == NULL &&
286 	    (any = sockaddr_any_by_family(AF_INET6)) == NULL)
287 		goto fail0;
288 
289 	sc = malloc(sizeof(*sc), M_DEVBUF, M_WAITOK|M_ZERO);
290 	mutex_init(&sc->sc_mtx, MUTEX_DRIVER, IPL_SOFTNET);
291 	cv_init(&sc->sc_condvar, "gre wait");
292 	cv_init(&sc->sc_fp_condvar, "gre fp");
293 
294 	if_initname(&sc->sc_if, ifc->ifc_name, unit);
295 	sc->sc_if.if_softc = sc;
296 	sc->sc_if.if_type = IFT_TUNNEL;
297 	sc->sc_if.if_addrlen = 0;
298 	sc->sc_if.if_hdrlen = sizeof(struct ip) + sizeof(struct gre_h);
299 	sc->sc_if.if_dlt = DLT_NULL;
300 	sc->sc_if.if_mtu = GREMTU;
301 	sc->sc_if.if_flags = IFF_POINTOPOINT|IFF_MULTICAST;
302 	sc->sc_if.if_output = gre_output;
303 	sc->sc_if.if_ioctl = gre_ioctl;
304 	sp = &sc->sc_soparm;
305 	sockaddr_copy(sstosa(&sp->sp_dst), sizeof(sp->sp_dst), any);
306 	sockaddr_copy(sstosa(&sp->sp_src), sizeof(sp->sp_src), any);
307 	sp->sp_proto = IPPROTO_GRE;
308 	sp->sp_type = SOCK_RAW;
309 
310 	sc->sc_fd = -1;
311 
312 	rc = kthread_create(PRI_NONE, KTHREAD_MPSAFE, NULL, gre_fp_recvloop, sc,
313 	    NULL, "%s", sc->sc_if.if_xname);
314 	if (rc)
315 		goto fail1;
316 
317 	gre_evcnt_attach(sc);
318 
319 	gre_bufq_init(&sc->sc_snd, 17);
320 	sc->sc_if.if_flags |= IFF_LINK0;
321 	if_attach(&sc->sc_if);
322 	if_alloc_sadl(&sc->sc_if);
323 	bpf_attach(&sc->sc_if, DLT_NULL, sizeof(uint32_t));
324 	atomic_inc_uint(&gre_count);
325 	return 0;
326 
327 fail1:
328 	cv_destroy(&sc->sc_fp_condvar);
329 	cv_destroy(&sc->sc_condvar);
330 	mutex_destroy(&sc->sc_mtx);
331 	free(sc, M_DEVBUF);
332 
333 fail0:
334 	return -1;
335 }
336 
337 static int
338 gre_clone_destroy(struct ifnet *ifp)
339 {
340 	int s;
341 	struct gre_softc *sc = ifp->if_softc;
342 
343 	GRE_DPRINTF(sc, "\n");
344 
345 	bpf_detach(ifp);
346 	s = splnet();
347 	if_detach(ifp);
348 
349 	GRE_DPRINTF(sc, "\n");
350 	/* Note that we must not hold the mutex while we call gre_reconf(). */
351 	gre_reconf(sc, NULL);
352 
353 	mutex_enter(&sc->sc_mtx);
354 	sc->sc_msg = GRE_M_STOP;
355 	cv_signal(&sc->sc_fp_condvar);
356 	while (sc->sc_fp_waiters > 0)
357 		cv_wait(&sc->sc_fp_condvar, &sc->sc_mtx);
358 	mutex_exit(&sc->sc_mtx);
359 
360 	splx(s);
361 
362 	cv_destroy(&sc->sc_condvar);
363 	cv_destroy(&sc->sc_fp_condvar);
364 	mutex_destroy(&sc->sc_mtx);
365 	gre_bufq_destroy(&sc->sc_snd);
366 	gre_evcnt_detach(sc);
367 	free(sc, M_DEVBUF);
368 
369 	atomic_dec_uint(&gre_count);
370 	return 0;
371 }
372 
373 static void
374 gre_receive(struct socket *so, void *arg, int events, int waitflag)
375 {
376 	struct gre_softc *sc = (struct gre_softc *)arg;
377 	int rc;
378 	struct gre_h gh;
379 	struct mbuf *m;
380 
381 	GRE_DPRINTF(sc, "enter\n");
382 
383 	sc->sc_recv_ev.ev_count++;
384 
385 	rc = gre_soreceive(so, &m);
386 	/* TBD Back off if ECONNREFUSED (indicates
387 	 * ICMP Port Unreachable)?
388 	 */
389 	if (rc == EWOULDBLOCK) {
390 		GRE_DPRINTF(sc, "EWOULDBLOCK\n");
391 		sc->sc_block_ev.ev_count++;
392 		return;
393 	} else if (rc != 0 || m == NULL) {
394 		GRE_DPRINTF(sc, "%s: rc %d m %p\n",
395 		    sc->sc_if.if_xname, rc, (void *)m);
396 		sc->sc_error_ev.ev_count++;
397 		return;
398 	}
399 
400 	if (__predict_false(m->m_len < sizeof(gh))) {
401 		if ((m = m_pullup(m, sizeof(gh))) == NULL) {
402 			GRE_DPRINTF(sc, "m_pullup failed\n");
403 			sc->sc_pullup_ev.ev_count++;
404 			return;
405 		}
406 	}
407 	memcpy(&gh, mtod(m, void *), sizeof(gh));
408 
409 	if (gre_input(sc, m, &gh) == 0) {
410 		sc->sc_unsupp_ev.ev_count++;
411 		GRE_DPRINTF(sc, "dropping unsupported\n");
412 		m_freem(m);
413 	}
414 }
415 
416 static void
417 gre_upcall_add(struct socket *so, void *arg)
418 {
419 	/* XXX What if the kernel already set an upcall? */
420 	KASSERT((so->so_rcv.sb_flags & SB_UPCALL) == 0);
421 	so->so_upcallarg = arg;
422 	so->so_upcall = gre_receive;
423 	so->so_rcv.sb_flags |= SB_UPCALL;
424 }
425 
426 static void
427 gre_upcall_remove(struct socket *so)
428 {
429 	so->so_rcv.sb_flags &= ~SB_UPCALL;
430 	so->so_upcallarg = NULL;
431 	so->so_upcall = NULL;
432 }
433 
434 static int
435 gre_socreate(struct gre_softc *sc, const struct gre_soparm *sp, int *fdout)
436 {
437 	int fd, rc;
438 	file_t *fp;
439 	struct socket *so;
440 	struct sockaddr_big sbig;
441 	sa_family_t af;
442 	int val;
443 
444 	GRE_DPRINTF(sc, "enter\n");
445 
446 	af = sp->sp_src.ss_family;
447 	rc = fsocreate(af, &so, sp->sp_type, sp->sp_proto, &fd, &fp, NULL);
448 	if (rc != 0) {
449 		GRE_DPRINTF(sc, "fsocreate failed\n");
450 		return rc;
451 	}
452 
453 	memcpy(&sbig, &sp->sp_src, sizeof(sp->sp_src));
454 	if ((rc = sobind(so, (struct sockaddr *)&sbig, curlwp)) != 0) {
455 		GRE_DPRINTF(sc, "sobind failed\n");
456 		goto out;
457 	}
458 
459 	memcpy(&sbig, &sp->sp_dst, sizeof(sp->sp_dst));
460 	solock(so);
461 	if ((rc = soconnect(so, (struct sockaddr *)&sbig, curlwp)) != 0) {
462 		GRE_DPRINTF(sc, "soconnect failed\n");
463 		sounlock(so);
464 		goto out;
465 	}
466 	sounlock(so);
467 
468 	/* XXX convert to a (new) SOL_SOCKET call */
469   	KASSERT(so->so_proto != NULL);
470  	rc = so_setsockopt(curlwp, so, IPPROTO_IP, IP_TTL,
471 	    &ip_gre_ttl, sizeof(ip_gre_ttl));
472   	if (rc != 0) {
473  		GRE_DPRINTF(sc, "so_setsockopt ttl failed\n");
474   		rc = 0;
475   	}
476 
477  	val = 1;
478  	rc = so_setsockopt(curlwp, so, SOL_SOCKET, SO_NOHEADER,
479 	    &val, sizeof(val));
480   	if (rc != 0) {
481  		GRE_DPRINTF(sc, "so_setsockopt SO_NOHEADER failed\n");
482 		rc = 0;
483 	}
484 out:
485 	if (rc != 0) {
486 		soclose(so);
487 		fd_abort(curproc, fp, fd);
488 	} else  {
489 		fd_affix(curproc, fp, fd);
490 		*fdout = fd;
491 	}
492 
493 	return rc;
494 }
495 
496 static int
497 gre_sosend(struct socket *so, struct mbuf *top)
498 {
499 	struct proc	*p;
500 	long		space, resid;
501 	int		error;
502 	struct lwp * const l = curlwp;
503 
504 	p = l->l_proc;
505 
506 	resid = top->m_pkthdr.len;
507 	if (p)
508 		l->l_ru.ru_msgsnd++;
509 #define	snderr(errno)	{ error = errno; goto release; }
510 
511 	solock(so);
512 	if ((error = sblock(&so->so_snd, M_NOWAIT)) != 0)
513 		goto out;
514 	if (so->so_state & SS_CANTSENDMORE)
515 		snderr(EPIPE);
516 	if (so->so_error) {
517 		error = so->so_error;
518 		so->so_error = 0;
519 		goto release;
520 	}
521 	if ((so->so_state & SS_ISCONNECTED) == 0) {
522 		if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
523 			snderr(ENOTCONN);
524 		} else {
525 			snderr(EDESTADDRREQ);
526 		}
527 	}
528 	space = sbspace(&so->so_snd);
529 	if (resid > so->so_snd.sb_hiwat)
530 		snderr(EMSGSIZE);
531 	if (space < resid)
532 		snderr(EWOULDBLOCK);
533 	/*
534 	 * Data is prepackaged in "top".
535 	 */
536 	if (so->so_state & SS_CANTSENDMORE)
537 		snderr(EPIPE);
538 	error = (*so->so_proto->pr_usrreqs->pr_send)(so,
539 	    top, NULL, NULL, l);
540 	top = NULL;
541  release:
542 	sbunlock(&so->so_snd);
543  out:
544  	sounlock(so);
545 	if (top != NULL)
546 		m_freem(top);
547 	return error;
548 }
549 
550 /* This is a stripped-down version of soreceive() that will never
551  * block.  It will support SOCK_DGRAM sockets.  It may also support
552  * SOCK_SEQPACKET sockets.
553  */
554 static int
555 gre_soreceive(struct socket *so, struct mbuf **mp0)
556 {
557 	struct mbuf *m, **mp;
558 	int flags, len, error, type;
559 	const struct protosw	*pr;
560 	struct mbuf *nextrecord;
561 
562 	KASSERT(mp0 != NULL);
563 
564 	flags = MSG_DONTWAIT;
565 	pr = so->so_proto;
566 	mp = mp0;
567 	type = 0;
568 
569 	*mp = NULL;
570 
571 	KASSERT(pr->pr_flags & PR_ATOMIC);
572  restart:
573 	if ((error = sblock(&so->so_rcv, M_NOWAIT)) != 0) {
574 		return error;
575 	}
576 	m = so->so_rcv.sb_mb;
577 	/*
578 	 * If we have less data than requested, do not block awaiting more.
579 	 */
580 	if (m == NULL) {
581 #ifdef DIAGNOSTIC
582 		if (so->so_rcv.sb_cc)
583 			panic("receive 1");
584 #endif
585 		if (so->so_error) {
586 			error = so->so_error;
587 			so->so_error = 0;
588 		} else if (so->so_state & SS_CANTRCVMORE)
589 			;
590 		else if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0
591 		      && (so->so_proto->pr_flags & PR_CONNREQUIRED))
592 			error = ENOTCONN;
593 		else
594 			error = EWOULDBLOCK;
595 		goto release;
596 	}
597 	/*
598 	 * On entry here, m points to the first record of the socket buffer.
599 	 * While we process the initial mbufs containing address and control
600 	 * info, we save a copy of m->m_nextpkt into nextrecord.
601 	 */
602 	if (curlwp != NULL)
603 		curlwp->l_ru.ru_msgrcv++;
604 	KASSERT(m == so->so_rcv.sb_mb);
605 	SBLASTRECORDCHK(&so->so_rcv, "soreceive 1");
606 	SBLASTMBUFCHK(&so->so_rcv, "soreceive 1");
607 	nextrecord = m->m_nextpkt;
608 	if (pr->pr_flags & PR_ADDR) {
609 #ifdef DIAGNOSTIC
610 		if (m->m_type != MT_SONAME)
611 			panic("receive 1a");
612 #endif
613 		sbfree(&so->so_rcv, m);
614 		m = so->so_rcv.sb_mb = m_free(m);
615 	}
616 	while (m != NULL && m->m_type == MT_CONTROL && error == 0) {
617 		sbfree(&so->so_rcv, m);
618 		/*
619 		 * Dispose of any SCM_RIGHTS message that went
620 		 * through the read path rather than recv.
621 		 */
622 		if (pr->pr_domain->dom_dispose &&
623 		    mtod(m, struct cmsghdr *)->cmsg_type == SCM_RIGHTS)
624 			(*pr->pr_domain->dom_dispose)(m);
625 		m = so->so_rcv.sb_mb = m_free(m);
626 	}
627 
628 	/*
629 	 * If m is non-NULL, we have some data to read.  From now on,
630 	 * make sure to keep sb_lastrecord consistent when working on
631 	 * the last packet on the chain (nextrecord == NULL) and we
632 	 * change m->m_nextpkt.
633 	 */
634 	if (m != NULL) {
635 		m->m_nextpkt = nextrecord;
636 		/*
637 		 * If nextrecord == NULL (this is a single chain),
638 		 * then sb_lastrecord may not be valid here if m
639 		 * was changed earlier.
640 		 */
641 		if (nextrecord == NULL) {
642 			KASSERT(so->so_rcv.sb_mb == m);
643 			so->so_rcv.sb_lastrecord = m;
644 		}
645 		type = m->m_type;
646 		if (type == MT_OOBDATA)
647 			flags |= MSG_OOB;
648 	} else {
649 		KASSERT(so->so_rcv.sb_mb == m);
650 		so->so_rcv.sb_mb = nextrecord;
651 		SB_EMPTY_FIXUP(&so->so_rcv);
652 	}
653 	SBLASTRECORDCHK(&so->so_rcv, "soreceive 2");
654 	SBLASTMBUFCHK(&so->so_rcv, "soreceive 2");
655 
656 	while (m != NULL) {
657 		if (m->m_type == MT_OOBDATA) {
658 			if (type != MT_OOBDATA)
659 				break;
660 		} else if (type == MT_OOBDATA)
661 			break;
662 #ifdef DIAGNOSTIC
663 		else if (m->m_type != MT_DATA && m->m_type != MT_HEADER)
664 			panic("receive 3");
665 #endif
666 		so->so_state &= ~SS_RCVATMARK;
667 		if (so->so_oobmark != 0 && so->so_oobmark < m->m_len)
668 			break;
669 		len = m->m_len;
670 		/*
671 		 * mp is set, just pass back the mbufs.
672 		 * Sockbuf must be consistent here (points to current mbuf,
673 		 * it points to next record) when we drop priority;
674 		 * we must note any additions to the sockbuf when we
675 		 * block interrupts again.
676 		 */
677 		if (m->m_flags & M_EOR)
678 			flags |= MSG_EOR;
679 		nextrecord = m->m_nextpkt;
680 		sbfree(&so->so_rcv, m);
681 		*mp = m;
682 		mp = &m->m_next;
683 		so->so_rcv.sb_mb = m = m->m_next;
684 		*mp = NULL;
685 		/*
686 		 * If m != NULL, we also know that
687 		 * so->so_rcv.sb_mb != NULL.
688 		 */
689 		KASSERT(so->so_rcv.sb_mb == m);
690 		if (m) {
691 			m->m_nextpkt = nextrecord;
692 			if (nextrecord == NULL)
693 				so->so_rcv.sb_lastrecord = m;
694 		} else {
695 			so->so_rcv.sb_mb = nextrecord;
696 			SB_EMPTY_FIXUP(&so->so_rcv);
697 		}
698 		SBLASTRECORDCHK(&so->so_rcv, "soreceive 3");
699 		SBLASTMBUFCHK(&so->so_rcv, "soreceive 3");
700 		if (so->so_oobmark) {
701 			so->so_oobmark -= len;
702 			if (so->so_oobmark == 0) {
703 				so->so_state |= SS_RCVATMARK;
704 				break;
705 			}
706 		}
707 		if (flags & MSG_EOR)
708 			break;
709 	}
710 
711 	if (m != NULL) {
712 		m_freem(*mp);
713 		*mp = NULL;
714 		error = ENOMEM;
715 		(void) sbdroprecord(&so->so_rcv);
716 	} else {
717 		/*
718 		 * First part is an inline SB_EMPTY_FIXUP().  Second
719 		 * part makes sure sb_lastrecord is up-to-date if
720 		 * there is still data in the socket buffer.
721 		 */
722 		so->so_rcv.sb_mb = nextrecord;
723 		if (so->so_rcv.sb_mb == NULL) {
724 			so->so_rcv.sb_mbtail = NULL;
725 			so->so_rcv.sb_lastrecord = NULL;
726 		} else if (nextrecord->m_nextpkt == NULL)
727 			so->so_rcv.sb_lastrecord = nextrecord;
728 	}
729 	SBLASTRECORDCHK(&so->so_rcv, "soreceive 4");
730 	SBLASTMBUFCHK(&so->so_rcv, "soreceive 4");
731 	if (pr->pr_flags & PR_WANTRCVD && so->so_pcb)
732 		(*pr->pr_usrreqs->pr_rcvd)(so, flags, curlwp);
733 	if (*mp0 == NULL && (flags & MSG_EOR) == 0 &&
734 	    (so->so_state & SS_CANTRCVMORE) == 0) {
735 		sbunlock(&so->so_rcv);
736 		goto restart;
737 	}
738 
739  release:
740 	sbunlock(&so->so_rcv);
741 	return error;
742 }
743 
744 static struct socket *
745 gre_reconf(struct gre_softc *sc, const struct gre_soparm *newsoparm)
746 {
747 	struct ifnet *ifp = &sc->sc_if;
748 
749 	GRE_DPRINTF(sc, "enter\n");
750 
751 shutdown:
752 	if (sc->sc_soparm.sp_so != NULL) {
753 		GRE_DPRINTF(sc, "\n");
754 		gre_upcall_remove(sc->sc_soparm.sp_so);
755 		softint_disestablish(sc->sc_si);
756 		sc->sc_si = NULL;
757 		gre_fp_send(sc, GRE_M_DELFP, NULL);
758 		gre_clearconf(&sc->sc_soparm, false);
759 	}
760 
761 	if (newsoparm != NULL) {
762 		GRE_DPRINTF(sc, "\n");
763 		sc->sc_soparm = *newsoparm;
764 		newsoparm = NULL;
765 	}
766 
767 	if (sc->sc_soparm.sp_so != NULL) {
768 		GRE_DPRINTF(sc, "\n");
769 		sc->sc_si = softint_establish(SOFTINT_NET, greintr, sc);
770 		gre_upcall_add(sc->sc_soparm.sp_so, sc);
771 		if ((ifp->if_flags & IFF_UP) == 0) {
772 			GRE_DPRINTF(sc, "down\n");
773 			goto shutdown;
774 		}
775 	}
776 
777 	GRE_DPRINTF(sc, "\n");
778 	if (sc->sc_soparm.sp_so != NULL)
779 		sc->sc_if.if_flags |= IFF_RUNNING;
780 	else {
781 		gre_bufq_purge(&sc->sc_snd);
782 		sc->sc_if.if_flags &= ~IFF_RUNNING;
783 	}
784 	return sc->sc_soparm.sp_so;
785 }
786 
787 static int
788 gre_input(struct gre_softc *sc, struct mbuf *m, const struct gre_h *gh)
789 {
790 	pktqueue_t *pktq = NULL;
791 	uint16_t flags;
792 	uint32_t af;		/* af passed to BPF tap */
793 	int hlen;
794 
795 	if_statadd2(&sc->sc_if, if_ipackets, 1, if_ibytes, m->m_pkthdr.len);
796 
797 	hlen = sizeof(struct gre_h);
798 
799 	/* process GRE flags as packet can be of variable len */
800 	flags = ntohs(gh->flags);
801 
802 	/* Checksum & Offset are present */
803 	if ((flags & GRE_CP) | (flags & GRE_RP))
804 		hlen += 4;
805 	/* We don't support routing fields (variable length) */
806 	if (flags & GRE_RP) {
807 		if_statinc(&sc->sc_if, if_ierrors);
808 		return 0;
809 	}
810 	if (flags & GRE_KP)
811 		hlen += 4;
812 	if (flags & GRE_SP)
813 		hlen += 4;
814 
815 	switch (ntohs(gh->ptype)) { /* ethertypes */
816 #ifdef INET
817 	case ETHERTYPE_IP:
818 		pktq = ip_pktq;
819 		af = AF_INET;
820 		break;
821 #endif
822 #ifdef NETATALK
823 	case ETHERTYPE_ATALK:
824 		pktq = at_pktq1;
825 		af = AF_APPLETALK;
826 		break;
827 #endif
828 #ifdef INET6
829 	case ETHERTYPE_IPV6:
830 		pktq = ip6_pktq;
831 		af = AF_INET6;
832 		break;
833 #endif
834 #ifdef MPLS
835 	case ETHERTYPE_MPLS:
836 		pktq = mpls_pktq;
837 		af = AF_MPLS;
838 		break;
839 #endif
840 	default:	   /* others not yet supported */
841 		GRE_DPRINTF(sc, "unhandled ethertype 0x%04x\n",
842 		    ntohs(gh->ptype));
843 		if_statinc(&sc->sc_if, if_noproto);
844 		return 0;
845 	}
846 
847 	if (hlen > m->m_pkthdr.len) {
848 		m_freem(m);
849 		if_statinc(&sc->sc_if, if_ierrors);
850 		return 1;
851 	}
852 	m_adj(m, hlen);
853 
854 	bpf_mtap_af(&sc->sc_if, af, m, BPF_D_IN);
855 
856 	m_set_rcvif(m, &sc->sc_if);
857 
858 	KASSERT(pktq != NULL);
859 	if (__predict_false(!pktq_enqueue(pktq, m, 0))) {
860 		m_freem(m);
861 	}
862 	return 1;	/* packet is done, no further processing needed */
863 }
864 
865 /*
866  * The output routine. Takes a packet and encapsulates it in the protocol
867  * given by sc->sc_soparm.sp_proto. See also RFC 1701 and RFC 2004
868  */
869 static int
870 gre_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
871     const struct rtentry *rt)
872 {
873 	int error = 0;
874 	struct gre_softc *sc = ifp->if_softc;
875 	struct gre_h gh = { .flags = 0 };
876 	uint16_t etype = 0;
877 
878 	KASSERT((m->m_flags & M_PKTHDR) != 0);
879 
880 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
881 		m_freem(m);
882 		error = ENETDOWN;
883 		goto end;
884 	}
885 
886 	bpf_mtap_af(ifp, dst->sa_family, m, BPF_D_OUT);
887 
888 	m->m_flags &= ~(M_BCAST|M_MCAST);
889 
890 	GRE_DPRINTF(sc, "dst->sa_family=%d\n", dst->sa_family);
891 	switch (dst->sa_family) {
892 #ifdef INET
893 	case AF_INET:
894 		/*
895 		 * TBD Extract the IP ToS field and set the
896 		 * encapsulating protocol's ToS to suit.
897 		 */
898 		etype = htons(ETHERTYPE_IP);
899 		break;
900 #endif
901 #ifdef NETATALK
902 	case AF_APPLETALK:
903 		etype = htons(ETHERTYPE_ATALK);
904 		break;
905 #endif
906 #ifdef INET6
907 	case AF_INET6:
908 		etype = htons(ETHERTYPE_IPV6);
909 		break;
910 #endif
911 	default:
912 		IF_DROP(&ifp->if_snd);
913 		m_freem(m);
914 		error = EAFNOSUPPORT;
915 		goto end;
916 	}
917 
918 #ifdef MPLS
919 	if (rt != NULL && rt_gettag(rt) != NULL) {
920 		union mpls_shim msh;
921 		msh.s_addr = MPLS_GETSADDR(rt);
922 		if (msh.shim.label != MPLS_LABEL_IMPLNULL)
923 			etype = htons(ETHERTYPE_MPLS);
924 	}
925 #endif
926 
927 	M_PREPEND(m, sizeof(gh), M_DONTWAIT);
928 	if (m == NULL) {
929 		IF_DROP(&ifp->if_snd);
930 		error = ENOBUFS;
931 		goto end;
932 	}
933 
934 	gh.ptype = etype;
935 	memcpy(mtod(m, void *), &gh, sizeof(gh));
936 	/* XXX Need to handle IP ToS.  Look at how I handle IP TTL. */
937 
938 	if_statadd2(ifp, if_opackets, 1, if_obytes, m->m_pkthdr.len);
939 
940 	/* Clear checksum-offload flags. */
941 	m->m_pkthdr.csum_flags = 0;
942 	m->m_pkthdr.csum_data = 0;
943 
944 	/* send it off */
945 	if ((error = gre_bufq_enqueue(&sc->sc_snd, m)) != 0) {
946 		sc->sc_oflow_ev.ev_count++;
947 		m_freem(m);
948 	} else {
949 		kpreempt_disable();
950 		softint_schedule(sc->sc_si);
951 		kpreempt_enable();
952 	}
953 
954 end:
955 	if (error)
956 		if_statinc(ifp, if_oerrors);
957 	return error;
958 }
959 
960 static int
961 gre_getsockname(struct socket *so, struct sockaddr *nam)
962 {
963 	return (*so->so_proto->pr_usrreqs->pr_sockaddr)(so, nam);
964 }
965 
966 static int
967 gre_getpeername(struct socket *so, struct sockaddr *nam)
968 {
969 	return (*so->so_proto->pr_usrreqs->pr_peeraddr)(so, nam);
970 }
971 
972 static int
973 gre_getnames(struct socket *so, struct lwp *l, struct sockaddr_storage *src,
974     struct sockaddr_storage *dst)
975 {
976 	struct sockaddr_storage ss;
977 	int rc;
978 
979 	solock(so);
980 	if ((rc = gre_getsockname(so, (struct sockaddr *)&ss)) != 0)
981 		goto out;
982 	*src = ss;
983 
984 	if ((rc = gre_getpeername(so, (struct sockaddr *)&ss)) != 0)
985 		goto out;
986 	*dst = ss;
987 out:
988 	sounlock(so);
989 	return rc;
990 }
991 
992 static void
993 gre_fp_recvloop(void *arg)
994 {
995 	struct gre_softc *sc = arg;
996 
997 	mutex_enter(&sc->sc_mtx);
998 	while (gre_fp_recv(sc))
999 		;
1000 	mutex_exit(&sc->sc_mtx);
1001 	kthread_exit(0);
1002 }
1003 
1004 static bool
1005 gre_fp_recv(struct gre_softc *sc)
1006 {
1007 	int fd, ofd, rc;
1008 	file_t *fp;
1009 
1010 	fp = sc->sc_fp;
1011 	ofd = sc->sc_fd;
1012 	fd = -1;
1013 
1014 	switch (sc->sc_msg) {
1015 	case GRE_M_STOP:
1016 		cv_signal(&sc->sc_fp_condvar);
1017 		return false;
1018 	case GRE_M_SETFP:
1019 		mutex_exit(&sc->sc_mtx);
1020 		rc = fd_dup(fp, 0, &fd, 0);
1021 		mutex_enter(&sc->sc_mtx);
1022 		if (rc != 0) {
1023 			sc->sc_msg = GRE_M_ERR;
1024 			break;
1025 		}
1026 		/*FALLTHROUGH*/
1027 	case GRE_M_DELFP:
1028 		mutex_exit(&sc->sc_mtx);
1029 		if (ofd != -1 && fd_getfile(ofd) != NULL)
1030 			fd_close(ofd);
1031 		mutex_enter(&sc->sc_mtx);
1032 		sc->sc_fd = fd;
1033 		sc->sc_msg = GRE_M_OK;
1034 		break;
1035 	default:
1036 		gre_fp_wait(sc);
1037 		return true;
1038 	}
1039 	cv_signal(&sc->sc_fp_condvar);
1040 	return true;
1041 }
1042 
1043 static bool
1044 gre_fp_send(struct gre_softc *sc, enum gre_msg msg, file_t *fp)
1045 {
1046 	bool rc;
1047 
1048 	mutex_enter(&sc->sc_mtx);
1049 	while (sc->sc_msg != GRE_M_NONE)
1050 		gre_fp_wait(sc);
1051 	sc->sc_fp = fp;
1052 	sc->sc_msg = msg;
1053 	cv_signal(&sc->sc_fp_condvar);
1054 	while (sc->sc_msg != GRE_M_STOP && sc->sc_msg != GRE_M_OK &&
1055 	            sc->sc_msg != GRE_M_ERR)
1056 		gre_fp_wait(sc);
1057 	rc = (sc->sc_msg != GRE_M_ERR);
1058 	sc->sc_msg = GRE_M_NONE;
1059 	cv_signal(&sc->sc_fp_condvar);
1060 	mutex_exit(&sc->sc_mtx);
1061 	return rc;
1062 }
1063 
1064 static int
1065 gre_ssock(struct ifnet *ifp, struct gre_soparm *sp, int fd)
1066 {
1067 	int error = 0;
1068 	const struct protosw *pr;
1069 	file_t *fp;
1070 	struct gre_softc *sc = ifp->if_softc;
1071 	struct socket *so;
1072 	struct sockaddr_storage dst, src;
1073 
1074 	if ((fp = fd_getfile(fd)) == NULL)
1075 		return EBADF;
1076 	if (fp->f_type != DTYPE_SOCKET) {
1077 		fd_putfile(fd);
1078 		return ENOTSOCK;
1079 	}
1080 
1081 	GRE_DPRINTF(sc, "\n");
1082 
1083 	so = fp->f_socket;
1084 	pr = so->so_proto;
1085 
1086 	GRE_DPRINTF(sc, "type %d, proto %d\n", pr->pr_type, pr->pr_protocol);
1087 
1088 	if ((pr->pr_flags & PR_ATOMIC) == 0 ||
1089 	    (sp->sp_type != 0 && pr->pr_type != sp->sp_type) ||
1090 	    (sp->sp_proto != 0 && pr->pr_protocol != 0 &&
1091 	     pr->pr_protocol != sp->sp_proto)) {
1092 		error = EINVAL;
1093 		goto err;
1094 	}
1095 
1096 	GRE_DPRINTF(sc, "\n");
1097 
1098 	/* check address */
1099 	if ((error = gre_getnames(so, curlwp, &src, &dst)) != 0)
1100 		goto err;
1101 
1102 	GRE_DPRINTF(sc, "\n");
1103 
1104 	if (!gre_fp_send(sc, GRE_M_SETFP, fp)) {
1105 		error = EBUSY;
1106 		goto err;
1107 	}
1108 
1109 	GRE_DPRINTF(sc, "\n");
1110 
1111 	sp->sp_src = src;
1112 	sp->sp_dst = dst;
1113 
1114 	sp->sp_so = so;
1115 
1116 err:
1117 	fd_putfile(fd);
1118 	return error;
1119 }
1120 
1121 static bool
1122 sockaddr_is_anyaddr(const struct sockaddr *sa)
1123 {
1124 	socklen_t anylen, salen;
1125 	const void *anyaddr, *addr;
1126 
1127 	if ((anyaddr = sockaddr_anyaddr(sa, &anylen)) == NULL ||
1128 	    (addr = sockaddr_const_addr(sa, &salen)) == NULL)
1129 		return false;
1130 
1131 	if (salen > anylen)
1132 		return false;
1133 
1134 	return memcmp(anyaddr, addr, MIN(anylen, salen)) == 0;
1135 }
1136 
1137 static bool
1138 gre_is_nullconf(const struct gre_soparm *sp)
1139 {
1140 	return sockaddr_is_anyaddr(sstocsa(&sp->sp_src)) ||
1141 	       sockaddr_is_anyaddr(sstocsa(&sp->sp_dst));
1142 }
1143 
1144 static void
1145 gre_clearconf(struct gre_soparm *sp, bool force)
1146 {
1147 	if (sp->sp_bysock || force) {
1148 		sockaddr_copy(sstosa(&sp->sp_src), sizeof(sp->sp_src),
1149 		    sockaddr_any(sstosa(&sp->sp_src)));
1150 		sockaddr_copy(sstosa(&sp->sp_dst), sizeof(sp->sp_dst),
1151 		    sockaddr_any(sstosa(&sp->sp_dst)));
1152 		sp->sp_bysock = false;
1153 	}
1154 	sp->sp_so = NULL; /* XXX */
1155 }
1156 
1157 static int
1158 gre_ioctl(struct ifnet *ifp, const u_long cmd, void *data)
1159 {
1160 	struct ifreq *ifr;
1161 	struct ifaddr *ifa = (struct ifaddr *)data;
1162 	struct if_laddrreq *lifr = (struct if_laddrreq *)data;
1163 	struct gre_softc *sc = ifp->if_softc;
1164 	struct gre_soparm *sp;
1165 	int fd, error = 0, oproto, otype, s;
1166 	struct gre_soparm sp0;
1167 
1168 	ifr = data;
1169 
1170 	GRE_DPRINTF(sc, "cmd %lu\n", cmd);
1171 
1172 	switch (cmd) {
1173 	case GRESPROTO:
1174 	case GRESADDRD:
1175 	case GRESADDRS:
1176 	case GRESSOCK:
1177 	case GREDSOCK:
1178 		if (kauth_authorize_network(kauth_cred_get(),
1179 		    KAUTH_NETWORK_INTERFACE,
1180 		    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
1181 		    NULL) != 0)
1182 			return EPERM;
1183 		break;
1184 	default:
1185 		break;
1186 	}
1187 
1188 	s = splnet();
1189 
1190 	sp0 = sc->sc_soparm;
1191 	sp0.sp_so = NULL;
1192 	sp = &sp0;
1193 
1194 	GRE_DPRINTF(sc, "\n");
1195 
1196 	switch (cmd) {
1197 	case SIOCINITIFADDR:
1198 		GRE_DPRINTF(sc, "\n");
1199 		if ((ifp->if_flags & IFF_UP) != 0)
1200 			break;
1201 		gre_clearconf(sp, false);
1202 		ifp->if_flags |= IFF_UP;
1203 		ifa->ifa_rtrequest = p2p_rtrequest;
1204 		goto mksocket;
1205 	case SIOCSIFFLAGS:
1206 		if ((error = ifioctl_common(ifp, cmd, data)) != 0)
1207 			break;
1208 		oproto = sp->sp_proto;
1209 		otype = sp->sp_type;
1210 		switch (ifr->ifr_flags & (IFF_LINK0|IFF_LINK2)) {
1211 		case IFF_LINK0|IFF_LINK2:
1212 			sp->sp_proto = IPPROTO_UDP;
1213 			sp->sp_type = SOCK_DGRAM;
1214 			break;
1215 		case IFF_LINK2:
1216 			sp->sp_proto = 0;
1217 			sp->sp_type = 0;
1218 			break;
1219 		case IFF_LINK0:
1220 			sp->sp_proto = IPPROTO_GRE;
1221 			sp->sp_type = SOCK_RAW;
1222 			break;
1223 		default:
1224 			GRE_DPRINTF(sc, "\n");
1225 			error = EINVAL;
1226 			goto out;
1227 		}
1228 		GRE_DPRINTF(sc, "\n");
1229 		gre_clearconf(sp, false);
1230 		if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) ==
1231 		    (IFF_UP|IFF_RUNNING) &&
1232 		    (oproto == sp->sp_proto || sp->sp_proto == 0) &&
1233 		    (otype == sp->sp_type || sp->sp_type == 0))
1234 			break;
1235 		switch (sp->sp_proto) {
1236 		case IPPROTO_UDP:
1237 		case IPPROTO_GRE:
1238 			goto mksocket;
1239 		default:
1240 			break;
1241 		}
1242 		break;
1243 	case SIOCSIFMTU:
1244 		/* XXX determine MTU automatically by probing w/
1245 		 * XXX do-not-fragment packets?
1246 		 */
1247 		if (ifr->ifr_mtu < 576) {
1248 			error = EINVAL;
1249 			break;
1250 		}
1251 		/*FALLTHROUGH*/
1252 	case SIOCGIFMTU:
1253 		if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET)
1254 			error = 0;
1255 		break;
1256 	case SIOCADDMULTI:
1257 	case SIOCDELMULTI:
1258 		if (ifr == NULL) {
1259 			error = EAFNOSUPPORT;
1260 			break;
1261 		}
1262 		switch (ifreq_getaddr(cmd, ifr)->sa_family) {
1263 #ifdef INET
1264 		case AF_INET:
1265 			break;
1266 #endif
1267 #ifdef INET6
1268 		case AF_INET6:
1269 			break;
1270 #endif
1271 		default:
1272 			error = EAFNOSUPPORT;
1273 			break;
1274 		}
1275 		break;
1276 	case GRESPROTO:
1277 		gre_clearconf(sp, false);
1278 		oproto = sp->sp_proto;
1279 		otype = sp->sp_type;
1280 		sp->sp_proto = ifr->ifr_flags;
1281 		switch (sp->sp_proto) {
1282 		case IPPROTO_UDP:
1283 			ifp->if_flags |= IFF_LINK0|IFF_LINK2;
1284 			sp->sp_type = SOCK_DGRAM;
1285 			break;
1286 		case IPPROTO_GRE:
1287 			ifp->if_flags |= IFF_LINK0;
1288 			ifp->if_flags &= ~IFF_LINK2;
1289 			sp->sp_type = SOCK_RAW;
1290 			break;
1291 		case 0:
1292 			ifp->if_flags &= ~IFF_LINK0;
1293 			ifp->if_flags |= IFF_LINK2;
1294 			sp->sp_type = 0;
1295 			break;
1296 		default:
1297 			error = EPROTONOSUPPORT;
1298 			break;
1299 		}
1300 		if ((oproto == sp->sp_proto || sp->sp_proto == 0) &&
1301 		    (otype == sp->sp_type || sp->sp_type == 0))
1302 			break;
1303 		switch (sp->sp_proto) {
1304 		case IPPROTO_UDP:
1305 		case IPPROTO_GRE:
1306 			goto mksocket;
1307 		default:
1308 			break;
1309 		}
1310 		break;
1311 	case GREGPROTO:
1312 		ifr->ifr_flags = sp->sp_proto;
1313 		break;
1314 	case GRESADDRS:
1315 	case GRESADDRD:
1316 		gre_clearconf(sp, false);
1317 		/* set tunnel endpoints and mark interface as up */
1318 		switch (cmd) {
1319 		case GRESADDRS:
1320 			sockaddr_copy(sstosa(&sp->sp_src),
1321 			    sizeof(sp->sp_src), ifreq_getaddr(cmd, ifr));
1322 			break;
1323 		case GRESADDRD:
1324 			sockaddr_copy(sstosa(&sp->sp_dst),
1325 			    sizeof(sp->sp_dst), ifreq_getaddr(cmd, ifr));
1326 			break;
1327 		}
1328 	checkaddr:
1329 		if (sockaddr_any(sstosa(&sp->sp_src)) == NULL ||
1330 		    sockaddr_any(sstosa(&sp->sp_dst)) == NULL) {
1331 			error = EINVAL;
1332 			break;
1333 		}
1334 		/* let gre_socreate() check the rest */
1335 	mksocket:
1336 		GRE_DPRINTF(sc, "\n");
1337 		/* If we're administratively down, or the configuration
1338 		 * is empty, there's no use creating a socket.
1339 		 */
1340 		if ((ifp->if_flags & IFF_UP) == 0 || gre_is_nullconf(sp))
1341 			goto sendconf;
1342 
1343 		GRE_DPRINTF(sc, "\n");
1344 		fd = 0;
1345 		error = gre_socreate(sc, sp, &fd);
1346 		if (error != 0)
1347 			break;
1348 
1349 	setsock:
1350 		GRE_DPRINTF(sc, "\n");
1351 
1352 		error = gre_ssock(ifp, sp, fd);
1353 
1354 		if (cmd != GRESSOCK) {
1355 			GRE_DPRINTF(sc, "\n");
1356 			/* XXX v. dodgy */
1357 			if (fd_getfile(fd) != NULL)
1358 				fd_close(fd);
1359 		}
1360 
1361 		if (error == 0) {
1362 	sendconf:
1363 			GRE_DPRINTF(sc, "\n");
1364 			ifp->if_flags &= ~IFF_RUNNING;
1365 			gre_reconf(sc, sp);
1366 		}
1367 
1368 		break;
1369 	case GREGADDRS:
1370 		ifreq_setaddr(cmd, ifr, sstosa(&sp->sp_src));
1371 		break;
1372 	case GREGADDRD:
1373 		ifreq_setaddr(cmd, ifr, sstosa(&sp->sp_dst));
1374 		break;
1375 	case GREDSOCK:
1376 		GRE_DPRINTF(sc, "\n");
1377 		if (sp->sp_bysock)
1378 			ifp->if_flags &= ~IFF_UP;
1379 		gre_clearconf(sp, false);
1380 		goto mksocket;
1381 	case GRESSOCK:
1382 		GRE_DPRINTF(sc, "\n");
1383 		gre_clearconf(sp, true);
1384 		fd = (int)ifr->ifr_value;
1385 		sp->sp_bysock = true;
1386 		ifp->if_flags |= IFF_UP;
1387 		goto setsock;
1388 	case SIOCSLIFPHYADDR:
1389 		GRE_DPRINTF(sc, "\n");
1390 		if (lifr->addr.ss_family != lifr->dstaddr.ss_family) {
1391 			error = EAFNOSUPPORT;
1392 			break;
1393 		}
1394 		sockaddr_copy(sstosa(&sp->sp_src), sizeof(sp->sp_src),
1395 		    sstosa(&lifr->addr));
1396 		sockaddr_copy(sstosa(&sp->sp_dst), sizeof(sp->sp_dst),
1397 		    sstosa(&lifr->dstaddr));
1398 		GRE_DPRINTF(sc, "\n");
1399 		goto checkaddr;
1400 	case SIOCDIFPHYADDR:
1401 		GRE_DPRINTF(sc, "\n");
1402 		gre_clearconf(sp, true);
1403 		ifp->if_flags &= ~IFF_UP;
1404 		goto mksocket;
1405 	case SIOCGLIFPHYADDR:
1406 		GRE_DPRINTF(sc, "\n");
1407 		if (gre_is_nullconf(sp)) {
1408 			error = EADDRNOTAVAIL;
1409 			break;
1410 		}
1411 		sockaddr_copy(sstosa(&lifr->addr), sizeof(lifr->addr),
1412 		    sstosa(&sp->sp_src));
1413 		sockaddr_copy(sstosa(&lifr->dstaddr), sizeof(lifr->dstaddr),
1414 		    sstosa(&sp->sp_dst));
1415 		GRE_DPRINTF(sc, "\n");
1416 		break;
1417 	default:
1418 		error = ifioctl_common(ifp, cmd, data);
1419 		break;
1420 	}
1421 out:
1422 	GRE_DPRINTF(sc, "\n");
1423 	splx(s);
1424 	return error;
1425 }
1426 
1427 /* ARGSUSED */
1428 void
1429 greattach(int count)
1430 {
1431 
1432 	/*
1433 	 * Nothing to do here, initialization is handled by the
1434 	 * module initialization code in greinit() below.
1435 	 */
1436 }
1437 
1438 static void
1439 greinit(void)
1440 {
1441 	if_clone_attach(&gre_cloner);
1442 }
1443 
1444 static int
1445 gredetach(void)
1446 {
1447 	int error = 0;
1448 
1449 	if (gre_count != 0)
1450 		error = EBUSY;
1451 
1452 	if (error == 0)
1453 		if_clone_detach(&gre_cloner);
1454 
1455 	return error;
1456 }
1457 
1458 /*
1459  * Module infrastructure
1460  */
1461 #include "if_module.h"
1462 
1463 IF_MODULE(MODULE_CLASS_DRIVER, gre, NULL)
1464