xref: /netbsd-src/sys/net/if_gre.c (revision 8ecbf5f02b752fcb7debe1a8fab1dc82602bc760)
1 /*	$NetBSD: if_gre.c,v 1.177 2020/01/29 04:18:34 thorpej 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 1.177 2020/01/29 04:18:34 thorpej 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/netisr.h>
88 #include <net/route.h>
89 #include <sys/device.h>
90 #include <sys/module.h>
91 #include <sys/atomic.h>
92 
93 #include <netinet/in_systm.h>
94 #include <netinet/in.h>
95 #include <netinet/ip.h> /* we always need this for sizeof(struct ip) */
96 
97 #ifdef INET
98 #include <netinet/in_var.h>
99 #include <netinet/ip_var.h>
100 #endif
101 
102 #ifdef INET6
103 #include <netinet6/in6_var.h>
104 #endif
105 
106 #ifdef MPLS
107 #include <netmpls/mpls.h>
108 #include <netmpls/mpls_var.h>
109 #endif
110 
111 #ifdef NETATALK
112 #include <netatalk/at.h>
113 #include <netatalk/at_var.h>
114 #include <netatalk/at_extern.h>
115 #endif
116 
117 #include <sys/time.h>
118 #include <net/bpf.h>
119 
120 #include <net/if_gre.h>
121 
122 #include "ioconf.h"
123 
124 /*
125  * It is not easy to calculate the right value for a GRE MTU.
126  * We leave this task to the admin and use the same default that
127  * other vendors use.
128  */
129 #define GREMTU 1476
130 
131 #ifdef GRE_DEBUG
132 int gre_debug = 0;
133 #define	GRE_DPRINTF(__sc, ...)						\
134 	do {								\
135 		if (__predict_false(gre_debug ||			\
136 		    ((__sc)->sc_if.if_flags & IFF_DEBUG) != 0)) {	\
137 			printf("%s.%d: ", __func__, __LINE__);		\
138 			printf(__VA_ARGS__);				\
139 		}							\
140 	} while (/*CONSTCOND*/0)
141 #else
142 #define	GRE_DPRINTF(__sc, __fmt, ...)	do { } while (/*CONSTCOND*/0)
143 #endif /* GRE_DEBUG */
144 
145 int ip_gre_ttl = GRE_TTL;
146 
147 static u_int gre_count;
148 
149 static int gre_clone_create(struct if_clone *, int);
150 static int gre_clone_destroy(struct ifnet *);
151 
152 static struct if_clone gre_cloner =
153     IF_CLONE_INITIALIZER("gre", gre_clone_create, gre_clone_destroy);
154 
155 static int gre_input(struct gre_softc *, struct mbuf *, const struct gre_h *);
156 static bool gre_is_nullconf(const struct gre_soparm *);
157 static int gre_output(struct ifnet *, struct mbuf *,
158 			   const struct sockaddr *, const struct rtentry *);
159 static int gre_ioctl(struct ifnet *, u_long, void *);
160 static int gre_getsockname(struct socket *, struct sockaddr *);
161 static int gre_getpeername(struct socket *, struct sockaddr *);
162 static int gre_getnames(struct socket *, struct lwp *,
163     struct sockaddr_storage *, struct sockaddr_storage *);
164 static void gre_clearconf(struct gre_soparm *, bool);
165 static int gre_soreceive(struct socket *, struct mbuf **);
166 static int gre_sosend(struct socket *, struct mbuf *);
167 static struct socket *gre_reconf(struct gre_softc *, const struct gre_soparm *);
168 
169 static bool gre_fp_send(struct gre_softc *, enum gre_msg, file_t *);
170 static bool gre_fp_recv(struct gre_softc *);
171 static void gre_fp_recvloop(void *);
172 
173 static void
174 gre_bufq_init(struct gre_bufq *bq, size_t len0)
175 {
176 	memset(bq, 0, sizeof(*bq));
177 	bq->bq_q = pcq_create(len0, KM_SLEEP);
178 	KASSERT(bq->bq_q != NULL);
179 }
180 
181 static struct mbuf *
182 gre_bufq_dequeue(struct gre_bufq *bq)
183 {
184 	return pcq_get(bq->bq_q);
185 }
186 
187 static void
188 gre_bufq_purge(struct gre_bufq *bq)
189 {
190 	struct mbuf *m;
191 
192 	while ((m = gre_bufq_dequeue(bq)) != NULL)
193 		m_freem(m);
194 }
195 
196 static void
197 gre_bufq_destroy(struct gre_bufq *bq)
198 {
199 	gre_bufq_purge(bq);
200 	pcq_destroy(bq->bq_q);
201 }
202 
203 static int
204 gre_bufq_enqueue(struct gre_bufq *bq, struct mbuf *m)
205 {
206 	KASSERT(bq->bq_q != NULL);
207 
208 	if (!pcq_put(bq->bq_q, m)) {
209 		bq->bq_drops++;
210 		return ENOBUFS;
211 	}
212 	return 0;
213 }
214 
215 static void
216 greintr(void *arg)
217 {
218 	struct gre_softc *sc = (struct gre_softc *)arg;
219 	struct socket *so = sc->sc_soparm.sp_so;
220 	int rc;
221 	struct mbuf *m;
222 
223 	KASSERT(so != NULL);
224 
225 	sc->sc_send_ev.ev_count++;
226 	GRE_DPRINTF(sc, "enter\n");
227 	while ((m = gre_bufq_dequeue(&sc->sc_snd)) != NULL) {
228 		/* XXX handle ENOBUFS? */
229 		if ((rc = gre_sosend(so, m)) != 0)
230 			GRE_DPRINTF(sc, "gre_sosend failed %d\n", rc);
231 	}
232 }
233 
234 /* Caller must hold sc->sc_mtx. */
235 static void
236 gre_fp_wait(struct gre_softc *sc)
237 {
238 	sc->sc_fp_waiters++;
239 	cv_wait(&sc->sc_fp_condvar, &sc->sc_mtx);
240 	sc->sc_fp_waiters--;
241 }
242 
243 static void
244 gre_evcnt_detach(struct gre_softc *sc)
245 {
246 	evcnt_detach(&sc->sc_recv_ev);
247 	evcnt_detach(&sc->sc_block_ev);
248 	evcnt_detach(&sc->sc_error_ev);
249 	evcnt_detach(&sc->sc_pullup_ev);
250 	evcnt_detach(&sc->sc_unsupp_ev);
251 
252 	evcnt_detach(&sc->sc_send_ev);
253 	evcnt_detach(&sc->sc_oflow_ev);
254 }
255 
256 static void
257 gre_evcnt_attach(struct gre_softc *sc)
258 {
259 	evcnt_attach_dynamic(&sc->sc_recv_ev, EVCNT_TYPE_MISC,
260 	    NULL, sc->sc_if.if_xname, "recv");
261 	evcnt_attach_dynamic(&sc->sc_block_ev, EVCNT_TYPE_MISC,
262 	    &sc->sc_recv_ev, sc->sc_if.if_xname, "would block");
263 	evcnt_attach_dynamic(&sc->sc_error_ev, EVCNT_TYPE_MISC,
264 	    &sc->sc_recv_ev, sc->sc_if.if_xname, "error");
265 	evcnt_attach_dynamic(&sc->sc_pullup_ev, EVCNT_TYPE_MISC,
266 	    &sc->sc_recv_ev, sc->sc_if.if_xname, "pullup failed");
267 	evcnt_attach_dynamic(&sc->sc_unsupp_ev, EVCNT_TYPE_MISC,
268 	    &sc->sc_recv_ev, sc->sc_if.if_xname, "unsupported");
269 
270 	evcnt_attach_dynamic(&sc->sc_send_ev, EVCNT_TYPE_MISC,
271 	    NULL, sc->sc_if.if_xname, "send");
272 	evcnt_attach_dynamic(&sc->sc_oflow_ev, EVCNT_TYPE_MISC,
273 	    &sc->sc_send_ev, sc->sc_if.if_xname, "overflow");
274 }
275 
276 static int
277 gre_clone_create(struct if_clone *ifc, int unit)
278 {
279 	int rc;
280 	struct gre_softc *sc;
281 	struct gre_soparm *sp;
282 	const struct sockaddr *any;
283 
284 	if ((any = sockaddr_any_by_family(AF_INET)) == NULL &&
285 	    (any = sockaddr_any_by_family(AF_INET6)) == NULL)
286 		goto fail0;
287 
288 	sc = malloc(sizeof(*sc), M_DEVBUF, M_WAITOK|M_ZERO);
289 	mutex_init(&sc->sc_mtx, MUTEX_DRIVER, IPL_SOFTNET);
290 	cv_init(&sc->sc_condvar, "gre wait");
291 	cv_init(&sc->sc_fp_condvar, "gre fp");
292 
293 	if_initname(&sc->sc_if, ifc->ifc_name, unit);
294 	sc->sc_if.if_softc = sc;
295 	sc->sc_if.if_type = IFT_TUNNEL;
296 	sc->sc_if.if_addrlen = 0;
297 	sc->sc_if.if_hdrlen = sizeof(struct ip) + sizeof(struct gre_h);
298 	sc->sc_if.if_dlt = DLT_NULL;
299 	sc->sc_if.if_mtu = GREMTU;
300 	sc->sc_if.if_flags = IFF_POINTOPOINT|IFF_MULTICAST;
301 	sc->sc_if.if_output = gre_output;
302 	sc->sc_if.if_ioctl = gre_ioctl;
303 	sp = &sc->sc_soparm;
304 	sockaddr_copy(sstosa(&sp->sp_dst), sizeof(sp->sp_dst), any);
305 	sockaddr_copy(sstosa(&sp->sp_src), sizeof(sp->sp_src), any);
306 	sp->sp_proto = IPPROTO_GRE;
307 	sp->sp_type = SOCK_RAW;
308 
309 	sc->sc_fd = -1;
310 
311 	rc = kthread_create(PRI_NONE, KTHREAD_MPSAFE, NULL, gre_fp_recvloop, sc,
312 	    NULL, "%s", sc->sc_if.if_xname);
313 	if (rc)
314 		goto fail1;
315 
316 	gre_evcnt_attach(sc);
317 
318 	gre_bufq_init(&sc->sc_snd, 17);
319 	sc->sc_if.if_flags |= IFF_LINK0;
320 	if_attach(&sc->sc_if);
321 	if_alloc_sadl(&sc->sc_if);
322 	bpf_attach(&sc->sc_if, DLT_NULL, sizeof(uint32_t));
323 	atomic_inc_uint(&gre_count);
324 	return 0;
325 
326 fail1:
327 	cv_destroy(&sc->sc_fp_condvar);
328 	cv_destroy(&sc->sc_condvar);
329 	mutex_destroy(&sc->sc_mtx);
330 	free(sc, M_DEVBUF);
331 
332 fail0:
333 	return -1;
334 }
335 
336 static int
337 gre_clone_destroy(struct ifnet *ifp)
338 {
339 	int s;
340 	struct gre_softc *sc = ifp->if_softc;
341 
342 	GRE_DPRINTF(sc, "\n");
343 
344 	bpf_detach(ifp);
345 	s = splnet();
346 	if_detach(ifp);
347 
348 	GRE_DPRINTF(sc, "\n");
349 	/* Note that we must not hold the mutex while we call gre_reconf(). */
350 	gre_reconf(sc, NULL);
351 
352 	mutex_enter(&sc->sc_mtx);
353 	sc->sc_msg = GRE_M_STOP;
354 	cv_signal(&sc->sc_fp_condvar);
355 	while (sc->sc_fp_waiters > 0)
356 		cv_wait(&sc->sc_fp_condvar, &sc->sc_mtx);
357 	mutex_exit(&sc->sc_mtx);
358 
359 	splx(s);
360 
361 	cv_destroy(&sc->sc_condvar);
362 	cv_destroy(&sc->sc_fp_condvar);
363 	mutex_destroy(&sc->sc_mtx);
364 	gre_bufq_destroy(&sc->sc_snd);
365 	gre_evcnt_detach(sc);
366 	free(sc, M_DEVBUF);
367 
368 	atomic_dec_uint(&gre_count);
369 	return 0;
370 }
371 
372 static void
373 gre_receive(struct socket *so, void *arg, int events, int waitflag)
374 {
375 	struct gre_softc *sc = (struct gre_softc *)arg;
376 	int rc;
377 	const struct gre_h *gh;
378 	struct mbuf *m;
379 
380 	GRE_DPRINTF(sc, "enter\n");
381 
382 	sc->sc_recv_ev.ev_count++;
383 
384 	rc = gre_soreceive(so, &m);
385 	/* TBD Back off if ECONNREFUSED (indicates
386 	 * ICMP Port Unreachable)?
387 	 */
388 	if (rc == EWOULDBLOCK) {
389 		GRE_DPRINTF(sc, "EWOULDBLOCK\n");
390 		sc->sc_block_ev.ev_count++;
391 		return;
392 	} else if (rc != 0 || m == NULL) {
393 		GRE_DPRINTF(sc, "%s: rc %d m %p\n",
394 		    sc->sc_if.if_xname, rc, (void *)m);
395 		sc->sc_error_ev.ev_count++;
396 		return;
397 	}
398 	if (m->m_len < sizeof(*gh) && (m = m_pullup(m, sizeof(*gh))) == NULL) {
399 		GRE_DPRINTF(sc, "m_pullup failed\n");
400 		sc->sc_pullup_ev.ev_count++;
401 		return;
402 	}
403 	gh = mtod(m, const struct gre_h *);
404 
405 	if (gre_input(sc, m, gh) == 0) {
406 		sc->sc_unsupp_ev.ev_count++;
407 		GRE_DPRINTF(sc, "dropping unsupported\n");
408 		m_freem(m);
409 	}
410 }
411 
412 static void
413 gre_upcall_add(struct socket *so, void *arg)
414 {
415 	/* XXX What if the kernel already set an upcall? */
416 	KASSERT((so->so_rcv.sb_flags & SB_UPCALL) == 0);
417 	so->so_upcallarg = arg;
418 	so->so_upcall = gre_receive;
419 	so->so_rcv.sb_flags |= SB_UPCALL;
420 }
421 
422 static void
423 gre_upcall_remove(struct socket *so)
424 {
425 	so->so_rcv.sb_flags &= ~SB_UPCALL;
426 	so->so_upcallarg = NULL;
427 	so->so_upcall = NULL;
428 }
429 
430 static int
431 gre_socreate(struct gre_softc *sc, const struct gre_soparm *sp, int *fdout)
432 {
433 	int fd, rc;
434 	struct socket *so;
435 	struct sockaddr_big sbig;
436 	sa_family_t af;
437 	int val;
438 
439 	GRE_DPRINTF(sc, "enter\n");
440 
441 	af = sp->sp_src.ss_family;
442 	rc = fsocreate(af, NULL, sp->sp_type, sp->sp_proto, &fd);
443 	if (rc != 0) {
444 		GRE_DPRINTF(sc, "fsocreate failed\n");
445 		return rc;
446 	}
447 
448 	if ((rc = fd_getsock(fd, &so)) != 0)
449 		return rc;
450 
451 	memcpy(&sbig, &sp->sp_src, sizeof(sp->sp_src));
452 	if ((rc = sobind(so, (struct sockaddr *)&sbig, curlwp)) != 0) {
453 		GRE_DPRINTF(sc, "sobind failed\n");
454 		goto out;
455 	}
456 
457 	memcpy(&sbig, &sp->sp_dst, sizeof(sp->sp_dst));
458 	solock(so);
459 	if ((rc = soconnect(so, (struct sockaddr *)&sbig, curlwp)) != 0) {
460 		GRE_DPRINTF(sc, "soconnect failed\n");
461 		sounlock(so);
462 		goto out;
463 	}
464 	sounlock(so);
465 
466 	/* XXX convert to a (new) SOL_SOCKET call */
467   	KASSERT(so->so_proto != NULL);
468  	rc = so_setsockopt(curlwp, so, IPPROTO_IP, IP_TTL,
469 	    &ip_gre_ttl, sizeof(ip_gre_ttl));
470   	if (rc != 0) {
471  		GRE_DPRINTF(sc, "so_setsockopt ttl failed\n");
472   		rc = 0;
473   	}
474 
475  	val = 1;
476  	rc = so_setsockopt(curlwp, so, SOL_SOCKET, SO_NOHEADER,
477 	    &val, sizeof(val));
478   	if (rc != 0) {
479  		GRE_DPRINTF(sc, "so_setsockopt SO_NOHEADER failed\n");
480 		rc = 0;
481 	}
482 out:
483 	if (rc != 0)
484 		fd_close(fd);
485 	else  {
486 		fd_putfile(fd);
487 		*fdout = fd;
488 	}
489 
490 	return rc;
491 }
492 
493 static int
494 gre_sosend(struct socket *so, struct mbuf *top)
495 {
496 	struct proc	*p;
497 	long		space, resid;
498 	int		error;
499 	struct lwp * const l = curlwp;
500 
501 	p = l->l_proc;
502 
503 	resid = top->m_pkthdr.len;
504 	if (p)
505 		l->l_ru.ru_msgsnd++;
506 #define	snderr(errno)	{ error = errno; goto release; }
507 
508 	solock(so);
509 	if ((error = sblock(&so->so_snd, M_NOWAIT)) != 0)
510 		goto out;
511 	if (so->so_state & SS_CANTSENDMORE)
512 		snderr(EPIPE);
513 	if (so->so_error) {
514 		error = so->so_error;
515 		so->so_error = 0;
516 		goto release;
517 	}
518 	if ((so->so_state & SS_ISCONNECTED) == 0) {
519 		if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
520 			snderr(ENOTCONN);
521 		} else {
522 			snderr(EDESTADDRREQ);
523 		}
524 	}
525 	space = sbspace(&so->so_snd);
526 	if (resid > so->so_snd.sb_hiwat)
527 		snderr(EMSGSIZE);
528 	if (space < resid)
529 		snderr(EWOULDBLOCK);
530 	/*
531 	 * Data is prepackaged in "top".
532 	 */
533 	if (so->so_state & SS_CANTSENDMORE)
534 		snderr(EPIPE);
535 	error = (*so->so_proto->pr_usrreqs->pr_send)(so,
536 	    top, NULL, NULL, l);
537 	top = NULL;
538  release:
539 	sbunlock(&so->so_snd);
540  out:
541  	sounlock(so);
542 	if (top != NULL)
543 		m_freem(top);
544 	return error;
545 }
546 
547 /* This is a stripped-down version of soreceive() that will never
548  * block.  It will support SOCK_DGRAM sockets.  It may also support
549  * SOCK_SEQPACKET sockets.
550  */
551 static int
552 gre_soreceive(struct socket *so, struct mbuf **mp0)
553 {
554 	struct mbuf *m, **mp;
555 	int flags, len, error, type;
556 	const struct protosw	*pr;
557 	struct mbuf *nextrecord;
558 
559 	KASSERT(mp0 != NULL);
560 
561 	flags = MSG_DONTWAIT;
562 	pr = so->so_proto;
563 	mp = mp0;
564 	type = 0;
565 
566 	*mp = NULL;
567 
568 	KASSERT(pr->pr_flags & PR_ATOMIC);
569  restart:
570 	if ((error = sblock(&so->so_rcv, M_NOWAIT)) != 0) {
571 		return error;
572 	}
573 	m = so->so_rcv.sb_mb;
574 	/*
575 	 * If we have less data than requested, do not block awaiting more.
576 	 */
577 	if (m == NULL) {
578 #ifdef DIAGNOSTIC
579 		if (so->so_rcv.sb_cc)
580 			panic("receive 1");
581 #endif
582 		if (so->so_error) {
583 			error = so->so_error;
584 			so->so_error = 0;
585 		} else if (so->so_state & SS_CANTRCVMORE)
586 			;
587 		else if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0
588 		      && (so->so_proto->pr_flags & PR_CONNREQUIRED))
589 			error = ENOTCONN;
590 		else
591 			error = EWOULDBLOCK;
592 		goto release;
593 	}
594 	/*
595 	 * On entry here, m points to the first record of the socket buffer.
596 	 * While we process the initial mbufs containing address and control
597 	 * info, we save a copy of m->m_nextpkt into nextrecord.
598 	 */
599 	if (curlwp != NULL)
600 		curlwp->l_ru.ru_msgrcv++;
601 	KASSERT(m == so->so_rcv.sb_mb);
602 	SBLASTRECORDCHK(&so->so_rcv, "soreceive 1");
603 	SBLASTMBUFCHK(&so->so_rcv, "soreceive 1");
604 	nextrecord = m->m_nextpkt;
605 	if (pr->pr_flags & PR_ADDR) {
606 #ifdef DIAGNOSTIC
607 		if (m->m_type != MT_SONAME)
608 			panic("receive 1a");
609 #endif
610 		sbfree(&so->so_rcv, m);
611 		m = so->so_rcv.sb_mb = m_free(m);
612 	}
613 	while (m != NULL && m->m_type == MT_CONTROL && error == 0) {
614 		sbfree(&so->so_rcv, m);
615 		/*
616 		 * Dispose of any SCM_RIGHTS message that went
617 		 * through the read path rather than recv.
618 		 */
619 		if (pr->pr_domain->dom_dispose &&
620 		    mtod(m, struct cmsghdr *)->cmsg_type == SCM_RIGHTS)
621 			(*pr->pr_domain->dom_dispose)(m);
622 		m = so->so_rcv.sb_mb = m_free(m);
623 	}
624 
625 	/*
626 	 * If m is non-NULL, we have some data to read.  From now on,
627 	 * make sure to keep sb_lastrecord consistent when working on
628 	 * the last packet on the chain (nextrecord == NULL) and we
629 	 * change m->m_nextpkt.
630 	 */
631 	if (m != NULL) {
632 		m->m_nextpkt = nextrecord;
633 		/*
634 		 * If nextrecord == NULL (this is a single chain),
635 		 * then sb_lastrecord may not be valid here if m
636 		 * was changed earlier.
637 		 */
638 		if (nextrecord == NULL) {
639 			KASSERT(so->so_rcv.sb_mb == m);
640 			so->so_rcv.sb_lastrecord = m;
641 		}
642 		type = m->m_type;
643 		if (type == MT_OOBDATA)
644 			flags |= MSG_OOB;
645 	} else {
646 		KASSERT(so->so_rcv.sb_mb == m);
647 		so->so_rcv.sb_mb = nextrecord;
648 		SB_EMPTY_FIXUP(&so->so_rcv);
649 	}
650 	SBLASTRECORDCHK(&so->so_rcv, "soreceive 2");
651 	SBLASTMBUFCHK(&so->so_rcv, "soreceive 2");
652 
653 	while (m != NULL) {
654 		if (m->m_type == MT_OOBDATA) {
655 			if (type != MT_OOBDATA)
656 				break;
657 		} else if (type == MT_OOBDATA)
658 			break;
659 #ifdef DIAGNOSTIC
660 		else if (m->m_type != MT_DATA && m->m_type != MT_HEADER)
661 			panic("receive 3");
662 #endif
663 		so->so_state &= ~SS_RCVATMARK;
664 		if (so->so_oobmark != 0 && so->so_oobmark < m->m_len)
665 			break;
666 		len = m->m_len;
667 		/*
668 		 * mp is set, just pass back the mbufs.
669 		 * Sockbuf must be consistent here (points to current mbuf,
670 		 * it points to next record) when we drop priority;
671 		 * we must note any additions to the sockbuf when we
672 		 * block interrupts again.
673 		 */
674 		if (m->m_flags & M_EOR)
675 			flags |= MSG_EOR;
676 		nextrecord = m->m_nextpkt;
677 		sbfree(&so->so_rcv, m);
678 		*mp = m;
679 		mp = &m->m_next;
680 		so->so_rcv.sb_mb = m = m->m_next;
681 		*mp = NULL;
682 		/*
683 		 * If m != NULL, we also know that
684 		 * so->so_rcv.sb_mb != NULL.
685 		 */
686 		KASSERT(so->so_rcv.sb_mb == m);
687 		if (m) {
688 			m->m_nextpkt = nextrecord;
689 			if (nextrecord == NULL)
690 				so->so_rcv.sb_lastrecord = m;
691 		} else {
692 			so->so_rcv.sb_mb = nextrecord;
693 			SB_EMPTY_FIXUP(&so->so_rcv);
694 		}
695 		SBLASTRECORDCHK(&so->so_rcv, "soreceive 3");
696 		SBLASTMBUFCHK(&so->so_rcv, "soreceive 3");
697 		if (so->so_oobmark) {
698 			so->so_oobmark -= len;
699 			if (so->so_oobmark == 0) {
700 				so->so_state |= SS_RCVATMARK;
701 				break;
702 			}
703 		}
704 		if (flags & MSG_EOR)
705 			break;
706 	}
707 
708 	if (m != NULL) {
709 		m_freem(*mp);
710 		*mp = NULL;
711 		error = ENOMEM;
712 		(void) sbdroprecord(&so->so_rcv);
713 	} else {
714 		/*
715 		 * First part is an inline SB_EMPTY_FIXUP().  Second
716 		 * part makes sure sb_lastrecord is up-to-date if
717 		 * there is still data in the socket buffer.
718 		 */
719 		so->so_rcv.sb_mb = nextrecord;
720 		if (so->so_rcv.sb_mb == NULL) {
721 			so->so_rcv.sb_mbtail = NULL;
722 			so->so_rcv.sb_lastrecord = NULL;
723 		} else if (nextrecord->m_nextpkt == NULL)
724 			so->so_rcv.sb_lastrecord = nextrecord;
725 	}
726 	SBLASTRECORDCHK(&so->so_rcv, "soreceive 4");
727 	SBLASTMBUFCHK(&so->so_rcv, "soreceive 4");
728 	if (pr->pr_flags & PR_WANTRCVD && so->so_pcb)
729 		(*pr->pr_usrreqs->pr_rcvd)(so, flags, curlwp);
730 	if (*mp0 == NULL && (flags & MSG_EOR) == 0 &&
731 	    (so->so_state & SS_CANTRCVMORE) == 0) {
732 		sbunlock(&so->so_rcv);
733 		goto restart;
734 	}
735 
736  release:
737 	sbunlock(&so->so_rcv);
738 	return error;
739 }
740 
741 static struct socket *
742 gre_reconf(struct gre_softc *sc, const struct gre_soparm *newsoparm)
743 {
744 	struct ifnet *ifp = &sc->sc_if;
745 
746 	GRE_DPRINTF(sc, "enter\n");
747 
748 shutdown:
749 	if (sc->sc_soparm.sp_so != NULL) {
750 		GRE_DPRINTF(sc, "\n");
751 		gre_upcall_remove(sc->sc_soparm.sp_so);
752 		softint_disestablish(sc->sc_si);
753 		sc->sc_si = NULL;
754 		gre_fp_send(sc, GRE_M_DELFP, NULL);
755 		gre_clearconf(&sc->sc_soparm, false);
756 	}
757 
758 	if (newsoparm != NULL) {
759 		GRE_DPRINTF(sc, "\n");
760 		sc->sc_soparm = *newsoparm;
761 		newsoparm = NULL;
762 	}
763 
764 	if (sc->sc_soparm.sp_so != NULL) {
765 		GRE_DPRINTF(sc, "\n");
766 		sc->sc_si = softint_establish(SOFTINT_NET, greintr, sc);
767 		gre_upcall_add(sc->sc_soparm.sp_so, sc);
768 		if ((ifp->if_flags & IFF_UP) == 0) {
769 			GRE_DPRINTF(sc, "down\n");
770 			goto shutdown;
771 		}
772 	}
773 
774 	GRE_DPRINTF(sc, "\n");
775 	if (sc->sc_soparm.sp_so != NULL)
776 		sc->sc_if.if_flags |= IFF_RUNNING;
777 	else {
778 		gre_bufq_purge(&sc->sc_snd);
779 		sc->sc_if.if_flags &= ~IFF_RUNNING;
780 	}
781 	return sc->sc_soparm.sp_so;
782 }
783 
784 static int
785 gre_input(struct gre_softc *sc, struct mbuf *m, const struct gre_h *gh)
786 {
787 	pktqueue_t *pktq = NULL;
788 	struct ifqueue *ifq = NULL;
789 	uint16_t flags;
790 	uint32_t af;		/* af passed to BPF tap */
791 	int isr = 0, s;
792 	int hlen;
793 
794 	if_statadd2(&sc->sc_if, if_ipackets, 1, if_ibytes, m->m_pkthdr.len);
795 
796 	hlen = sizeof(struct gre_h);
797 
798 	/* process GRE flags as packet can be of variable len */
799 	flags = ntohs(gh->flags);
800 
801 	/* Checksum & Offset are present */
802 	if ((flags & GRE_CP) | (flags & GRE_RP))
803 		hlen += 4;
804 	/* We don't support routing fields (variable length) */
805 	if (flags & GRE_RP) {
806 		if_statinc(&sc->sc_if, if_ierrors);
807 		return 0;
808 	}
809 	if (flags & GRE_KP)
810 		hlen += 4;
811 	if (flags & GRE_SP)
812 		hlen += 4;
813 
814 	switch (ntohs(gh->ptype)) { /* ethertypes */
815 #ifdef INET
816 	case ETHERTYPE_IP:
817 		pktq = ip_pktq;
818 		af = AF_INET;
819 		break;
820 #endif
821 #ifdef NETATALK
822 	case ETHERTYPE_ATALK:
823 		ifq = &atintrq1;
824 		isr = NETISR_ATALK;
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 		ifq = &mplsintrq;
837 		isr = NETISR_MPLS;
838 		af = AF_MPLS;
839 		break;
840 #endif
841 	default:	   /* others not yet supported */
842 		GRE_DPRINTF(sc, "unhandled ethertype 0x%04x\n",
843 		    ntohs(gh->ptype));
844 		if_statinc(&sc->sc_if, if_noproto);
845 		return 0;
846 	}
847 
848 	if (hlen > m->m_pkthdr.len) {
849 		m_freem(m);
850 		if_statinc(&sc->sc_if, if_ierrors);
851 		return 1;
852 	}
853 	m_adj(m, hlen);
854 
855 	bpf_mtap_af(&sc->sc_if, af, m, BPF_D_IN);
856 
857 	m_set_rcvif(m, &sc->sc_if);
858 
859 	if (__predict_true(pktq)) {
860 		if (__predict_false(!pktq_enqueue(pktq, m, 0))) {
861 			m_freem(m);
862 		}
863 		return 1;
864 	}
865 
866 	s = splnet();
867 	if (IF_QFULL(ifq)) {
868 		IF_DROP(ifq);
869 		m_freem(m);
870 	} else {
871 		IF_ENQUEUE(ifq, m);
872 	}
873 	/* we need schednetisr since the address family may change */
874 	schednetisr(isr);
875 	splx(s);
876 
877 	return 1;	/* packet is done, no further processing needed */
878 }
879 
880 /*
881  * The output routine. Takes a packet and encapsulates it in the protocol
882  * given by sc->sc_soparm.sp_proto. See also RFC 1701 and RFC 2004
883  */
884 static int
885 gre_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
886     const struct rtentry *rt)
887 {
888 	int error = 0;
889 	struct gre_softc *sc = ifp->if_softc;
890 	struct gre_h *gh;
891 	uint16_t etype = 0;
892 
893 	KASSERT((m->m_flags & M_PKTHDR) != 0);
894 
895 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
896 		m_freem(m);
897 		error = ENETDOWN;
898 		goto end;
899 	}
900 
901 	bpf_mtap_af(ifp, dst->sa_family, m, BPF_D_OUT);
902 
903 	m->m_flags &= ~(M_BCAST|M_MCAST);
904 
905 	GRE_DPRINTF(sc, "dst->sa_family=%d\n", dst->sa_family);
906 	switch (dst->sa_family) {
907 #ifdef INET
908 	case AF_INET:
909 		/*
910 		 * TBD Extract the IP ToS field and set the
911 		 * encapsulating protocol's ToS to suit.
912 		 */
913 		etype = htons(ETHERTYPE_IP);
914 		break;
915 #endif
916 #ifdef NETATALK
917 	case AF_APPLETALK:
918 		etype = htons(ETHERTYPE_ATALK);
919 		break;
920 #endif
921 #ifdef INET6
922 	case AF_INET6:
923 		etype = htons(ETHERTYPE_IPV6);
924 		break;
925 #endif
926 	default:
927 		IF_DROP(&ifp->if_snd);
928 		m_freem(m);
929 		error = EAFNOSUPPORT;
930 		goto end;
931 	}
932 
933 #ifdef MPLS
934 	if (rt != NULL && rt_gettag(rt) != NULL) {
935 		union mpls_shim msh;
936 		msh.s_addr = MPLS_GETSADDR(rt);
937 		if (msh.shim.label != MPLS_LABEL_IMPLNULL)
938 			etype = htons(ETHERTYPE_MPLS);
939 	}
940 #endif
941 
942 	M_PREPEND(m, sizeof(*gh), M_DONTWAIT);
943 
944 	if (m == NULL) {
945 		IF_DROP(&ifp->if_snd);
946 		error = ENOBUFS;
947 		goto end;
948 	}
949 
950 	gh = mtod(m, struct gre_h *);
951 	gh->flags = 0;
952 	gh->ptype = etype;
953 	/* XXX Need to handle IP ToS.  Look at how I handle IP TTL. */
954 
955 	if_statadd2(ifp, if_opackets, 1, if_obytes, m->m_pkthdr.len);
956 
957 	/* Clear checksum-offload flags. */
958 	m->m_pkthdr.csum_flags = 0;
959 	m->m_pkthdr.csum_data = 0;
960 
961 	/* send it off */
962 	if ((error = gre_bufq_enqueue(&sc->sc_snd, m)) != 0) {
963 		sc->sc_oflow_ev.ev_count++;
964 		m_freem(m);
965 	} else {
966 		kpreempt_disable();
967 		softint_schedule(sc->sc_si);
968 		kpreempt_enable();
969 	}
970 
971 end:
972 	if (error)
973 		if_statinc(ifp, if_oerrors);
974 	return error;
975 }
976 
977 static int
978 gre_getsockname(struct socket *so, struct sockaddr *nam)
979 {
980 	return (*so->so_proto->pr_usrreqs->pr_sockaddr)(so, nam);
981 }
982 
983 static int
984 gre_getpeername(struct socket *so, struct sockaddr *nam)
985 {
986 	return (*so->so_proto->pr_usrreqs->pr_peeraddr)(so, nam);
987 }
988 
989 static int
990 gre_getnames(struct socket *so, struct lwp *l, struct sockaddr_storage *src,
991     struct sockaddr_storage *dst)
992 {
993 	struct sockaddr_storage ss;
994 	int rc;
995 
996 	solock(so);
997 	if ((rc = gre_getsockname(so, (struct sockaddr *)&ss)) != 0)
998 		goto out;
999 	*src = ss;
1000 
1001 	if ((rc = gre_getpeername(so, (struct sockaddr *)&ss)) != 0)
1002 		goto out;
1003 	*dst = ss;
1004 out:
1005 	sounlock(so);
1006 	return rc;
1007 }
1008 
1009 static void
1010 gre_fp_recvloop(void *arg)
1011 {
1012 	struct gre_softc *sc = arg;
1013 
1014 	mutex_enter(&sc->sc_mtx);
1015 	while (gre_fp_recv(sc))
1016 		;
1017 	mutex_exit(&sc->sc_mtx);
1018 	kthread_exit(0);
1019 }
1020 
1021 static bool
1022 gre_fp_recv(struct gre_softc *sc)
1023 {
1024 	int fd, ofd, rc;
1025 	file_t *fp;
1026 
1027 	fp = sc->sc_fp;
1028 	ofd = sc->sc_fd;
1029 	fd = -1;
1030 
1031 	switch (sc->sc_msg) {
1032 	case GRE_M_STOP:
1033 		cv_signal(&sc->sc_fp_condvar);
1034 		return false;
1035 	case GRE_M_SETFP:
1036 		mutex_exit(&sc->sc_mtx);
1037 		rc = fd_dup(fp, 0, &fd, 0);
1038 		mutex_enter(&sc->sc_mtx);
1039 		if (rc != 0) {
1040 			sc->sc_msg = GRE_M_ERR;
1041 			break;
1042 		}
1043 		/*FALLTHROUGH*/
1044 	case GRE_M_DELFP:
1045 		mutex_exit(&sc->sc_mtx);
1046 		if (ofd != -1 && fd_getfile(ofd) != NULL)
1047 			fd_close(ofd);
1048 		mutex_enter(&sc->sc_mtx);
1049 		sc->sc_fd = fd;
1050 		sc->sc_msg = GRE_M_OK;
1051 		break;
1052 	default:
1053 		gre_fp_wait(sc);
1054 		return true;
1055 	}
1056 	cv_signal(&sc->sc_fp_condvar);
1057 	return true;
1058 }
1059 
1060 static bool
1061 gre_fp_send(struct gre_softc *sc, enum gre_msg msg, file_t *fp)
1062 {
1063 	bool rc;
1064 
1065 	mutex_enter(&sc->sc_mtx);
1066 	while (sc->sc_msg != GRE_M_NONE)
1067 		gre_fp_wait(sc);
1068 	sc->sc_fp = fp;
1069 	sc->sc_msg = msg;
1070 	cv_signal(&sc->sc_fp_condvar);
1071 	while (sc->sc_msg != GRE_M_STOP && sc->sc_msg != GRE_M_OK &&
1072 	            sc->sc_msg != GRE_M_ERR)
1073 		gre_fp_wait(sc);
1074 	rc = (sc->sc_msg != GRE_M_ERR);
1075 	sc->sc_msg = GRE_M_NONE;
1076 	cv_signal(&sc->sc_fp_condvar);
1077 	mutex_exit(&sc->sc_mtx);
1078 	return rc;
1079 }
1080 
1081 static int
1082 gre_ssock(struct ifnet *ifp, struct gre_soparm *sp, int fd)
1083 {
1084 	int error = 0;
1085 	const struct protosw *pr;
1086 	file_t *fp;
1087 	struct gre_softc *sc = ifp->if_softc;
1088 	struct socket *so;
1089 	struct sockaddr_storage dst, src;
1090 
1091 	if ((fp = fd_getfile(fd)) == NULL)
1092 		return EBADF;
1093 	if (fp->f_type != DTYPE_SOCKET) {
1094 		fd_putfile(fd);
1095 		return ENOTSOCK;
1096 	}
1097 
1098 	GRE_DPRINTF(sc, "\n");
1099 
1100 	so = fp->f_socket;
1101 	pr = so->so_proto;
1102 
1103 	GRE_DPRINTF(sc, "type %d, proto %d\n", pr->pr_type, pr->pr_protocol);
1104 
1105 	if ((pr->pr_flags & PR_ATOMIC) == 0 ||
1106 	    (sp->sp_type != 0 && pr->pr_type != sp->sp_type) ||
1107 	    (sp->sp_proto != 0 && pr->pr_protocol != 0 &&
1108 	     pr->pr_protocol != sp->sp_proto)) {
1109 		error = EINVAL;
1110 		goto err;
1111 	}
1112 
1113 	GRE_DPRINTF(sc, "\n");
1114 
1115 	/* check address */
1116 	if ((error = gre_getnames(so, curlwp, &src, &dst)) != 0)
1117 		goto err;
1118 
1119 	GRE_DPRINTF(sc, "\n");
1120 
1121 	if (!gre_fp_send(sc, GRE_M_SETFP, fp)) {
1122 		error = EBUSY;
1123 		goto err;
1124 	}
1125 
1126 	GRE_DPRINTF(sc, "\n");
1127 
1128 	sp->sp_src = src;
1129 	sp->sp_dst = dst;
1130 
1131 	sp->sp_so = so;
1132 
1133 err:
1134 	fd_putfile(fd);
1135 	return error;
1136 }
1137 
1138 static bool
1139 sockaddr_is_anyaddr(const struct sockaddr *sa)
1140 {
1141 	socklen_t anylen, salen;
1142 	const void *anyaddr, *addr;
1143 
1144 	if ((anyaddr = sockaddr_anyaddr(sa, &anylen)) == NULL ||
1145 	    (addr = sockaddr_const_addr(sa, &salen)) == NULL)
1146 		return false;
1147 
1148 	if (salen > anylen)
1149 		return false;
1150 
1151 	return memcmp(anyaddr, addr, MIN(anylen, salen)) == 0;
1152 }
1153 
1154 static bool
1155 gre_is_nullconf(const struct gre_soparm *sp)
1156 {
1157 	return sockaddr_is_anyaddr(sstocsa(&sp->sp_src)) ||
1158 	       sockaddr_is_anyaddr(sstocsa(&sp->sp_dst));
1159 }
1160 
1161 static void
1162 gre_clearconf(struct gre_soparm *sp, bool force)
1163 {
1164 	if (sp->sp_bysock || force) {
1165 		sockaddr_copy(sstosa(&sp->sp_src), sizeof(sp->sp_src),
1166 		    sockaddr_any(sstosa(&sp->sp_src)));
1167 		sockaddr_copy(sstosa(&sp->sp_dst), sizeof(sp->sp_dst),
1168 		    sockaddr_any(sstosa(&sp->sp_dst)));
1169 		sp->sp_bysock = false;
1170 	}
1171 	sp->sp_so = NULL; /* XXX */
1172 }
1173 
1174 static int
1175 gre_ioctl(struct ifnet *ifp, const u_long cmd, void *data)
1176 {
1177 	struct ifreq *ifr;
1178 	struct ifaddr *ifa = (struct ifaddr *)data;
1179 	struct if_laddrreq *lifr = (struct if_laddrreq *)data;
1180 	struct gre_softc *sc = ifp->if_softc;
1181 	struct gre_soparm *sp;
1182 	int fd, error = 0, oproto, otype, s;
1183 	struct gre_soparm sp0;
1184 
1185 	ifr = data;
1186 
1187 	GRE_DPRINTF(sc, "cmd %lu\n", cmd);
1188 
1189 	switch (cmd) {
1190 	case GRESPROTO:
1191 	case GRESADDRD:
1192 	case GRESADDRS:
1193 	case GRESSOCK:
1194 	case GREDSOCK:
1195 		if (kauth_authorize_network(curlwp->l_cred,
1196 		    KAUTH_NETWORK_INTERFACE,
1197 		    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
1198 		    NULL) != 0)
1199 			return EPERM;
1200 		break;
1201 	default:
1202 		break;
1203 	}
1204 
1205 	s = splnet();
1206 
1207 	sp0 = sc->sc_soparm;
1208 	sp0.sp_so = NULL;
1209 	sp = &sp0;
1210 
1211 	GRE_DPRINTF(sc, "\n");
1212 
1213 	switch (cmd) {
1214 	case SIOCINITIFADDR:
1215 		GRE_DPRINTF(sc, "\n");
1216 		if ((ifp->if_flags & IFF_UP) != 0)
1217 			break;
1218 		gre_clearconf(sp, false);
1219 		ifp->if_flags |= IFF_UP;
1220 		ifa->ifa_rtrequest = p2p_rtrequest;
1221 		goto mksocket;
1222 	case SIOCSIFFLAGS:
1223 		if ((error = ifioctl_common(ifp, cmd, data)) != 0)
1224 			break;
1225 		oproto = sp->sp_proto;
1226 		otype = sp->sp_type;
1227 		switch (ifr->ifr_flags & (IFF_LINK0|IFF_LINK2)) {
1228 		case IFF_LINK0|IFF_LINK2:
1229 			sp->sp_proto = IPPROTO_UDP;
1230 			sp->sp_type = SOCK_DGRAM;
1231 			break;
1232 		case IFF_LINK2:
1233 			sp->sp_proto = 0;
1234 			sp->sp_type = 0;
1235 			break;
1236 		case IFF_LINK0:
1237 			sp->sp_proto = IPPROTO_GRE;
1238 			sp->sp_type = SOCK_RAW;
1239 			break;
1240 		default:
1241 			GRE_DPRINTF(sc, "\n");
1242 			error = EINVAL;
1243 			goto out;
1244 		}
1245 		GRE_DPRINTF(sc, "\n");
1246 		gre_clearconf(sp, false);
1247 		if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) ==
1248 		    (IFF_UP|IFF_RUNNING) &&
1249 		    (oproto == sp->sp_proto || sp->sp_proto == 0) &&
1250 		    (otype == sp->sp_type || sp->sp_type == 0))
1251 			break;
1252 		switch (sp->sp_proto) {
1253 		case IPPROTO_UDP:
1254 		case IPPROTO_GRE:
1255 			goto mksocket;
1256 		default:
1257 			break;
1258 		}
1259 		break;
1260 	case SIOCSIFMTU:
1261 		/* XXX determine MTU automatically by probing w/
1262 		 * XXX do-not-fragment packets?
1263 		 */
1264 		if (ifr->ifr_mtu < 576) {
1265 			error = EINVAL;
1266 			break;
1267 		}
1268 		/*FALLTHROUGH*/
1269 	case SIOCGIFMTU:
1270 		if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET)
1271 			error = 0;
1272 		break;
1273 	case SIOCADDMULTI:
1274 	case SIOCDELMULTI:
1275 		if (ifr == NULL) {
1276 			error = EAFNOSUPPORT;
1277 			break;
1278 		}
1279 		switch (ifreq_getaddr(cmd, ifr)->sa_family) {
1280 #ifdef INET
1281 		case AF_INET:
1282 			break;
1283 #endif
1284 #ifdef INET6
1285 		case AF_INET6:
1286 			break;
1287 #endif
1288 		default:
1289 			error = EAFNOSUPPORT;
1290 			break;
1291 		}
1292 		break;
1293 	case GRESPROTO:
1294 		gre_clearconf(sp, false);
1295 		oproto = sp->sp_proto;
1296 		otype = sp->sp_type;
1297 		sp->sp_proto = ifr->ifr_flags;
1298 		switch (sp->sp_proto) {
1299 		case IPPROTO_UDP:
1300 			ifp->if_flags |= IFF_LINK0|IFF_LINK2;
1301 			sp->sp_type = SOCK_DGRAM;
1302 			break;
1303 		case IPPROTO_GRE:
1304 			ifp->if_flags |= IFF_LINK0;
1305 			ifp->if_flags &= ~IFF_LINK2;
1306 			sp->sp_type = SOCK_RAW;
1307 			break;
1308 		case 0:
1309 			ifp->if_flags &= ~IFF_LINK0;
1310 			ifp->if_flags |= IFF_LINK2;
1311 			sp->sp_type = 0;
1312 			break;
1313 		default:
1314 			error = EPROTONOSUPPORT;
1315 			break;
1316 		}
1317 		if ((oproto == sp->sp_proto || sp->sp_proto == 0) &&
1318 		    (otype == sp->sp_type || sp->sp_type == 0))
1319 			break;
1320 		switch (sp->sp_proto) {
1321 		case IPPROTO_UDP:
1322 		case IPPROTO_GRE:
1323 			goto mksocket;
1324 		default:
1325 			break;
1326 		}
1327 		break;
1328 	case GREGPROTO:
1329 		ifr->ifr_flags = sp->sp_proto;
1330 		break;
1331 	case GRESADDRS:
1332 	case GRESADDRD:
1333 		gre_clearconf(sp, false);
1334 		/* set tunnel endpoints and mark interface as up */
1335 		switch (cmd) {
1336 		case GRESADDRS:
1337 			sockaddr_copy(sstosa(&sp->sp_src),
1338 			    sizeof(sp->sp_src), ifreq_getaddr(cmd, ifr));
1339 			break;
1340 		case GRESADDRD:
1341 			sockaddr_copy(sstosa(&sp->sp_dst),
1342 			    sizeof(sp->sp_dst), ifreq_getaddr(cmd, ifr));
1343 			break;
1344 		}
1345 	checkaddr:
1346 		if (sockaddr_any(sstosa(&sp->sp_src)) == NULL ||
1347 		    sockaddr_any(sstosa(&sp->sp_dst)) == NULL) {
1348 			error = EINVAL;
1349 			break;
1350 		}
1351 		/* let gre_socreate() check the rest */
1352 	mksocket:
1353 		GRE_DPRINTF(sc, "\n");
1354 		/* If we're administratively down, or the configuration
1355 		 * is empty, there's no use creating a socket.
1356 		 */
1357 		if ((ifp->if_flags & IFF_UP) == 0 || gre_is_nullconf(sp))
1358 			goto sendconf;
1359 
1360 		GRE_DPRINTF(sc, "\n");
1361 		fd = 0;
1362 		error = gre_socreate(sc, sp, &fd);
1363 		if (error != 0)
1364 			break;
1365 
1366 	setsock:
1367 		GRE_DPRINTF(sc, "\n");
1368 
1369 		error = gre_ssock(ifp, sp, fd);
1370 
1371 		if (cmd != GRESSOCK) {
1372 			GRE_DPRINTF(sc, "\n");
1373 			/* XXX v. dodgy */
1374 			if (fd_getfile(fd) != NULL)
1375 				fd_close(fd);
1376 		}
1377 
1378 		if (error == 0) {
1379 	sendconf:
1380 			GRE_DPRINTF(sc, "\n");
1381 			ifp->if_flags &= ~IFF_RUNNING;
1382 			gre_reconf(sc, sp);
1383 		}
1384 
1385 		break;
1386 	case GREGADDRS:
1387 		ifreq_setaddr(cmd, ifr, sstosa(&sp->sp_src));
1388 		break;
1389 	case GREGADDRD:
1390 		ifreq_setaddr(cmd, ifr, sstosa(&sp->sp_dst));
1391 		break;
1392 	case GREDSOCK:
1393 		GRE_DPRINTF(sc, "\n");
1394 		if (sp->sp_bysock)
1395 			ifp->if_flags &= ~IFF_UP;
1396 		gre_clearconf(sp, false);
1397 		goto mksocket;
1398 	case GRESSOCK:
1399 		GRE_DPRINTF(sc, "\n");
1400 		gre_clearconf(sp, true);
1401 		fd = (int)ifr->ifr_value;
1402 		sp->sp_bysock = true;
1403 		ifp->if_flags |= IFF_UP;
1404 		goto setsock;
1405 	case SIOCSLIFPHYADDR:
1406 		GRE_DPRINTF(sc, "\n");
1407 		if (lifr->addr.ss_family != lifr->dstaddr.ss_family) {
1408 			error = EAFNOSUPPORT;
1409 			break;
1410 		}
1411 		sockaddr_copy(sstosa(&sp->sp_src), sizeof(sp->sp_src),
1412 		    sstosa(&lifr->addr));
1413 		sockaddr_copy(sstosa(&sp->sp_dst), sizeof(sp->sp_dst),
1414 		    sstosa(&lifr->dstaddr));
1415 		GRE_DPRINTF(sc, "\n");
1416 		goto checkaddr;
1417 	case SIOCDIFPHYADDR:
1418 		GRE_DPRINTF(sc, "\n");
1419 		gre_clearconf(sp, true);
1420 		ifp->if_flags &= ~IFF_UP;
1421 		goto mksocket;
1422 	case SIOCGLIFPHYADDR:
1423 		GRE_DPRINTF(sc, "\n");
1424 		if (gre_is_nullconf(sp)) {
1425 			error = EADDRNOTAVAIL;
1426 			break;
1427 		}
1428 		sockaddr_copy(sstosa(&lifr->addr), sizeof(lifr->addr),
1429 		    sstosa(&sp->sp_src));
1430 		sockaddr_copy(sstosa(&lifr->dstaddr), sizeof(lifr->dstaddr),
1431 		    sstosa(&sp->sp_dst));
1432 		GRE_DPRINTF(sc, "\n");
1433 		break;
1434 	default:
1435 		error = ifioctl_common(ifp, cmd, data);
1436 		break;
1437 	}
1438 out:
1439 	GRE_DPRINTF(sc, "\n");
1440 	splx(s);
1441 	return error;
1442 }
1443 
1444 /* ARGSUSED */
1445 void
1446 greattach(int count)
1447 {
1448 
1449 	/*
1450 	 * Nothing to do here, initialization is handled by the
1451 	 * module initialization code in greinit() below.
1452 	 */
1453 }
1454 
1455 static void
1456 greinit(void)
1457 {
1458 	if_clone_attach(&gre_cloner);
1459 }
1460 
1461 static int
1462 gredetach(void)
1463 {
1464 	int error = 0;
1465 
1466 	if (gre_count != 0)
1467 		error = EBUSY;
1468 
1469 	if (error == 0)
1470 		if_clone_detach(&gre_cloner);
1471 
1472 	return error;
1473 }
1474 
1475 /*
1476  * Module infrastructure
1477  */
1478 #include "if_module.h"
1479 
1480 IF_MODULE(MODULE_CLASS_DRIVER, gre, NULL)
1481