xref: /netbsd-src/sys/net/if_gre.c (revision afab4e300d3a9fb07dd8c80daf53d0feb3345706)
1 /*	$NetBSD: if_gre.c,v 1.184 2022/09/03 02:47:59 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 1.184 2022/09/03 02:47:59 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/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 	struct socket *so;
439 	struct sockaddr_big sbig;
440 	sa_family_t af;
441 	int val;
442 
443 	GRE_DPRINTF(sc, "enter\n");
444 
445 	af = sp->sp_src.ss_family;
446 	rc = fsocreate(af, NULL, sp->sp_type, sp->sp_proto, &fd);
447 	if (rc != 0) {
448 		GRE_DPRINTF(sc, "fsocreate failed\n");
449 		return rc;
450 	}
451 
452 	if ((rc = fd_getsock(fd, &so)) != 0)
453 		return rc;
454 
455 	memcpy(&sbig, &sp->sp_src, sizeof(sp->sp_src));
456 	if ((rc = sobind(so, (struct sockaddr *)&sbig, curlwp)) != 0) {
457 		GRE_DPRINTF(sc, "sobind failed\n");
458 		goto out;
459 	}
460 
461 	memcpy(&sbig, &sp->sp_dst, sizeof(sp->sp_dst));
462 	solock(so);
463 	if ((rc = soconnect(so, (struct sockaddr *)&sbig, curlwp)) != 0) {
464 		GRE_DPRINTF(sc, "soconnect failed\n");
465 		sounlock(so);
466 		goto out;
467 	}
468 	sounlock(so);
469 
470 	/* XXX convert to a (new) SOL_SOCKET call */
471   	KASSERT(so->so_proto != NULL);
472  	rc = so_setsockopt(curlwp, so, IPPROTO_IP, IP_TTL,
473 	    &ip_gre_ttl, sizeof(ip_gre_ttl));
474   	if (rc != 0) {
475  		GRE_DPRINTF(sc, "so_setsockopt ttl failed\n");
476   		rc = 0;
477   	}
478 
479  	val = 1;
480  	rc = so_setsockopt(curlwp, so, SOL_SOCKET, SO_NOHEADER,
481 	    &val, sizeof(val));
482   	if (rc != 0) {
483  		GRE_DPRINTF(sc, "so_setsockopt SO_NOHEADER failed\n");
484 		rc = 0;
485 	}
486 out:
487 	if (rc != 0)
488 		fd_close(fd);
489 	else  {
490 		fd_putfile(fd);
491 		*fdout = fd;
492 	}
493 
494 	return rc;
495 }
496 
497 static int
498 gre_sosend(struct socket *so, struct mbuf *top)
499 {
500 	struct proc	*p;
501 	long		space, resid;
502 	int		error;
503 	struct lwp * const l = curlwp;
504 
505 	p = l->l_proc;
506 
507 	resid = top->m_pkthdr.len;
508 	if (p)
509 		l->l_ru.ru_msgsnd++;
510 #define	snderr(errno)	{ error = errno; goto release; }
511 
512 	solock(so);
513 	if ((error = sblock(&so->so_snd, M_NOWAIT)) != 0)
514 		goto out;
515 	if (so->so_state & SS_CANTSENDMORE)
516 		snderr(EPIPE);
517 	if (so->so_error) {
518 		error = so->so_error;
519 		so->so_error = 0;
520 		goto release;
521 	}
522 	if ((so->so_state & SS_ISCONNECTED) == 0) {
523 		if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
524 			snderr(ENOTCONN);
525 		} else {
526 			snderr(EDESTADDRREQ);
527 		}
528 	}
529 	space = sbspace(&so->so_snd);
530 	if (resid > so->so_snd.sb_hiwat)
531 		snderr(EMSGSIZE);
532 	if (space < resid)
533 		snderr(EWOULDBLOCK);
534 	/*
535 	 * Data is prepackaged in "top".
536 	 */
537 	if (so->so_state & SS_CANTSENDMORE)
538 		snderr(EPIPE);
539 	error = (*so->so_proto->pr_usrreqs->pr_send)(so,
540 	    top, NULL, NULL, l);
541 	top = NULL;
542  release:
543 	sbunlock(&so->so_snd);
544  out:
545  	sounlock(so);
546 	if (top != NULL)
547 		m_freem(top);
548 	return error;
549 }
550 
551 /* This is a stripped-down version of soreceive() that will never
552  * block.  It will support SOCK_DGRAM sockets.  It may also support
553  * SOCK_SEQPACKET sockets.
554  */
555 static int
556 gre_soreceive(struct socket *so, struct mbuf **mp0)
557 {
558 	struct mbuf *m, **mp;
559 	int flags, len, error, type;
560 	const struct protosw	*pr;
561 	struct mbuf *nextrecord;
562 
563 	KASSERT(mp0 != NULL);
564 
565 	flags = MSG_DONTWAIT;
566 	pr = so->so_proto;
567 	mp = mp0;
568 	type = 0;
569 
570 	*mp = NULL;
571 
572 	KASSERT(pr->pr_flags & PR_ATOMIC);
573  restart:
574 	if ((error = sblock(&so->so_rcv, M_NOWAIT)) != 0) {
575 		return error;
576 	}
577 	m = so->so_rcv.sb_mb;
578 	/*
579 	 * If we have less data than requested, do not block awaiting more.
580 	 */
581 	if (m == NULL) {
582 #ifdef DIAGNOSTIC
583 		if (so->so_rcv.sb_cc)
584 			panic("receive 1");
585 #endif
586 		if (so->so_error) {
587 			error = so->so_error;
588 			so->so_error = 0;
589 		} else if (so->so_state & SS_CANTRCVMORE)
590 			;
591 		else if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0
592 		      && (so->so_proto->pr_flags & PR_CONNREQUIRED))
593 			error = ENOTCONN;
594 		else
595 			error = EWOULDBLOCK;
596 		goto release;
597 	}
598 	/*
599 	 * On entry here, m points to the first record of the socket buffer.
600 	 * While we process the initial mbufs containing address and control
601 	 * info, we save a copy of m->m_nextpkt into nextrecord.
602 	 */
603 	if (curlwp != NULL)
604 		curlwp->l_ru.ru_msgrcv++;
605 	KASSERT(m == so->so_rcv.sb_mb);
606 	SBLASTRECORDCHK(&so->so_rcv, "soreceive 1");
607 	SBLASTMBUFCHK(&so->so_rcv, "soreceive 1");
608 	nextrecord = m->m_nextpkt;
609 	if (pr->pr_flags & PR_ADDR) {
610 #ifdef DIAGNOSTIC
611 		if (m->m_type != MT_SONAME)
612 			panic("receive 1a");
613 #endif
614 		sbfree(&so->so_rcv, m);
615 		m = so->so_rcv.sb_mb = m_free(m);
616 	}
617 	while (m != NULL && m->m_type == MT_CONTROL && error == 0) {
618 		sbfree(&so->so_rcv, m);
619 		/*
620 		 * Dispose of any SCM_RIGHTS message that went
621 		 * through the read path rather than recv.
622 		 */
623 		if (pr->pr_domain->dom_dispose &&
624 		    mtod(m, struct cmsghdr *)->cmsg_type == SCM_RIGHTS)
625 			(*pr->pr_domain->dom_dispose)(m);
626 		m = so->so_rcv.sb_mb = m_free(m);
627 	}
628 
629 	/*
630 	 * If m is non-NULL, we have some data to read.  From now on,
631 	 * make sure to keep sb_lastrecord consistent when working on
632 	 * the last packet on the chain (nextrecord == NULL) and we
633 	 * change m->m_nextpkt.
634 	 */
635 	if (m != NULL) {
636 		m->m_nextpkt = nextrecord;
637 		/*
638 		 * If nextrecord == NULL (this is a single chain),
639 		 * then sb_lastrecord may not be valid here if m
640 		 * was changed earlier.
641 		 */
642 		if (nextrecord == NULL) {
643 			KASSERT(so->so_rcv.sb_mb == m);
644 			so->so_rcv.sb_lastrecord = m;
645 		}
646 		type = m->m_type;
647 		if (type == MT_OOBDATA)
648 			flags |= MSG_OOB;
649 	} else {
650 		KASSERT(so->so_rcv.sb_mb == m);
651 		so->so_rcv.sb_mb = nextrecord;
652 		SB_EMPTY_FIXUP(&so->so_rcv);
653 	}
654 	SBLASTRECORDCHK(&so->so_rcv, "soreceive 2");
655 	SBLASTMBUFCHK(&so->so_rcv, "soreceive 2");
656 
657 	while (m != NULL) {
658 		if (m->m_type == MT_OOBDATA) {
659 			if (type != MT_OOBDATA)
660 				break;
661 		} else if (type == MT_OOBDATA)
662 			break;
663 #ifdef DIAGNOSTIC
664 		else if (m->m_type != MT_DATA && m->m_type != MT_HEADER)
665 			panic("receive 3");
666 #endif
667 		so->so_state &= ~SS_RCVATMARK;
668 		if (so->so_oobmark != 0 && so->so_oobmark < m->m_len)
669 			break;
670 		len = m->m_len;
671 		/*
672 		 * mp is set, just pass back the mbufs.
673 		 * Sockbuf must be consistent here (points to current mbuf,
674 		 * it points to next record) when we drop priority;
675 		 * we must note any additions to the sockbuf when we
676 		 * block interrupts again.
677 		 */
678 		if (m->m_flags & M_EOR)
679 			flags |= MSG_EOR;
680 		nextrecord = m->m_nextpkt;
681 		sbfree(&so->so_rcv, m);
682 		*mp = m;
683 		mp = &m->m_next;
684 		so->so_rcv.sb_mb = m = m->m_next;
685 		*mp = NULL;
686 		/*
687 		 * If m != NULL, we also know that
688 		 * so->so_rcv.sb_mb != NULL.
689 		 */
690 		KASSERT(so->so_rcv.sb_mb == m);
691 		if (m) {
692 			m->m_nextpkt = nextrecord;
693 			if (nextrecord == NULL)
694 				so->so_rcv.sb_lastrecord = m;
695 		} else {
696 			so->so_rcv.sb_mb = nextrecord;
697 			SB_EMPTY_FIXUP(&so->so_rcv);
698 		}
699 		SBLASTRECORDCHK(&so->so_rcv, "soreceive 3");
700 		SBLASTMBUFCHK(&so->so_rcv, "soreceive 3");
701 		if (so->so_oobmark) {
702 			so->so_oobmark -= len;
703 			if (so->so_oobmark == 0) {
704 				so->so_state |= SS_RCVATMARK;
705 				break;
706 			}
707 		}
708 		if (flags & MSG_EOR)
709 			break;
710 	}
711 
712 	if (m != NULL) {
713 		m_freem(*mp);
714 		*mp = NULL;
715 		error = ENOMEM;
716 		(void) sbdroprecord(&so->so_rcv);
717 	} else {
718 		/*
719 		 * First part is an inline SB_EMPTY_FIXUP().  Second
720 		 * part makes sure sb_lastrecord is up-to-date if
721 		 * there is still data in the socket buffer.
722 		 */
723 		so->so_rcv.sb_mb = nextrecord;
724 		if (so->so_rcv.sb_mb == NULL) {
725 			so->so_rcv.sb_mbtail = NULL;
726 			so->so_rcv.sb_lastrecord = NULL;
727 		} else if (nextrecord->m_nextpkt == NULL)
728 			so->so_rcv.sb_lastrecord = nextrecord;
729 	}
730 	SBLASTRECORDCHK(&so->so_rcv, "soreceive 4");
731 	SBLASTMBUFCHK(&so->so_rcv, "soreceive 4");
732 	if (pr->pr_flags & PR_WANTRCVD && so->so_pcb)
733 		(*pr->pr_usrreqs->pr_rcvd)(so, flags, curlwp);
734 	if (*mp0 == NULL && (flags & MSG_EOR) == 0 &&
735 	    (so->so_state & SS_CANTRCVMORE) == 0) {
736 		sbunlock(&so->so_rcv);
737 		goto restart;
738 	}
739 
740  release:
741 	sbunlock(&so->so_rcv);
742 	return error;
743 }
744 
745 static struct socket *
746 gre_reconf(struct gre_softc *sc, const struct gre_soparm *newsoparm)
747 {
748 	struct ifnet *ifp = &sc->sc_if;
749 
750 	GRE_DPRINTF(sc, "enter\n");
751 
752 shutdown:
753 	if (sc->sc_soparm.sp_so != NULL) {
754 		GRE_DPRINTF(sc, "\n");
755 		gre_upcall_remove(sc->sc_soparm.sp_so);
756 		softint_disestablish(sc->sc_si);
757 		sc->sc_si = NULL;
758 		gre_fp_send(sc, GRE_M_DELFP, NULL);
759 		gre_clearconf(&sc->sc_soparm, false);
760 	}
761 
762 	if (newsoparm != NULL) {
763 		GRE_DPRINTF(sc, "\n");
764 		sc->sc_soparm = *newsoparm;
765 		newsoparm = NULL;
766 	}
767 
768 	if (sc->sc_soparm.sp_so != NULL) {
769 		GRE_DPRINTF(sc, "\n");
770 		sc->sc_si = softint_establish(SOFTINT_NET, greintr, sc);
771 		gre_upcall_add(sc->sc_soparm.sp_so, sc);
772 		if ((ifp->if_flags & IFF_UP) == 0) {
773 			GRE_DPRINTF(sc, "down\n");
774 			goto shutdown;
775 		}
776 	}
777 
778 	GRE_DPRINTF(sc, "\n");
779 	if (sc->sc_soparm.sp_so != NULL)
780 		sc->sc_if.if_flags |= IFF_RUNNING;
781 	else {
782 		gre_bufq_purge(&sc->sc_snd);
783 		sc->sc_if.if_flags &= ~IFF_RUNNING;
784 	}
785 	return sc->sc_soparm.sp_so;
786 }
787 
788 static int
789 gre_input(struct gre_softc *sc, struct mbuf *m, const struct gre_h *gh)
790 {
791 	pktqueue_t *pktq = NULL;
792 	uint16_t flags;
793 	uint32_t af;		/* af passed to BPF tap */
794 	int hlen;
795 
796 	if_statadd2(&sc->sc_if, if_ipackets, 1, if_ibytes, m->m_pkthdr.len);
797 
798 	hlen = sizeof(struct gre_h);
799 
800 	/* process GRE flags as packet can be of variable len */
801 	flags = ntohs(gh->flags);
802 
803 	/* Checksum & Offset are present */
804 	if ((flags & GRE_CP) | (flags & GRE_RP))
805 		hlen += 4;
806 	/* We don't support routing fields (variable length) */
807 	if (flags & GRE_RP) {
808 		if_statinc(&sc->sc_if, if_ierrors);
809 		return 0;
810 	}
811 	if (flags & GRE_KP)
812 		hlen += 4;
813 	if (flags & GRE_SP)
814 		hlen += 4;
815 
816 	switch (ntohs(gh->ptype)) { /* ethertypes */
817 #ifdef INET
818 	case ETHERTYPE_IP:
819 		pktq = ip_pktq;
820 		af = AF_INET;
821 		break;
822 #endif
823 #ifdef NETATALK
824 	case ETHERTYPE_ATALK:
825 		pktq = at_pktq1;
826 		af = AF_APPLETALK;
827 		break;
828 #endif
829 #ifdef INET6
830 	case ETHERTYPE_IPV6:
831 		pktq = ip6_pktq;
832 		af = AF_INET6;
833 		break;
834 #endif
835 #ifdef MPLS
836 	case ETHERTYPE_MPLS:
837 		pktq = mpls_pktq;
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 	KASSERT(pktq != NULL);
860 	if (__predict_false(!pktq_enqueue(pktq, m, 0))) {
861 		m_freem(m);
862 	}
863 	return 1;	/* packet is done, no further processing needed */
864 }
865 
866 /*
867  * The output routine. Takes a packet and encapsulates it in the protocol
868  * given by sc->sc_soparm.sp_proto. See also RFC 1701 and RFC 2004
869  */
870 static int
871 gre_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
872     const struct rtentry *rt)
873 {
874 	int error = 0;
875 	struct gre_softc *sc = ifp->if_softc;
876 	struct gre_h gh = { .flags = 0 };
877 	uint16_t etype = 0;
878 
879 	KASSERT((m->m_flags & M_PKTHDR) != 0);
880 
881 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
882 		m_freem(m);
883 		error = ENETDOWN;
884 		goto end;
885 	}
886 
887 	bpf_mtap_af(ifp, dst->sa_family, m, BPF_D_OUT);
888 
889 	m->m_flags &= ~(M_BCAST|M_MCAST);
890 
891 	GRE_DPRINTF(sc, "dst->sa_family=%d\n", dst->sa_family);
892 	switch (dst->sa_family) {
893 #ifdef INET
894 	case AF_INET:
895 		/*
896 		 * TBD Extract the IP ToS field and set the
897 		 * encapsulating protocol's ToS to suit.
898 		 */
899 		etype = htons(ETHERTYPE_IP);
900 		break;
901 #endif
902 #ifdef NETATALK
903 	case AF_APPLETALK:
904 		etype = htons(ETHERTYPE_ATALK);
905 		break;
906 #endif
907 #ifdef INET6
908 	case AF_INET6:
909 		etype = htons(ETHERTYPE_IPV6);
910 		break;
911 #endif
912 	default:
913 		IF_DROP(&ifp->if_snd);
914 		m_freem(m);
915 		error = EAFNOSUPPORT;
916 		goto end;
917 	}
918 
919 #ifdef MPLS
920 	if (rt != NULL && rt_gettag(rt) != NULL) {
921 		union mpls_shim msh;
922 		msh.s_addr = MPLS_GETSADDR(rt);
923 		if (msh.shim.label != MPLS_LABEL_IMPLNULL)
924 			etype = htons(ETHERTYPE_MPLS);
925 	}
926 #endif
927 
928 	M_PREPEND(m, sizeof(gh), M_DONTWAIT);
929 	if (m == NULL) {
930 		IF_DROP(&ifp->if_snd);
931 		error = ENOBUFS;
932 		goto end;
933 	}
934 
935 	gh.ptype = etype;
936 	memcpy(mtod(m, void *), &gh, sizeof(gh));
937 	/* XXX Need to handle IP ToS.  Look at how I handle IP TTL. */
938 
939 	if_statadd2(ifp, if_opackets, 1, if_obytes, m->m_pkthdr.len);
940 
941 	/* Clear checksum-offload flags. */
942 	m->m_pkthdr.csum_flags = 0;
943 	m->m_pkthdr.csum_data = 0;
944 
945 	/* send it off */
946 	if ((error = gre_bufq_enqueue(&sc->sc_snd, m)) != 0) {
947 		sc->sc_oflow_ev.ev_count++;
948 		m_freem(m);
949 	} else {
950 		kpreempt_disable();
951 		softint_schedule(sc->sc_si);
952 		kpreempt_enable();
953 	}
954 
955 end:
956 	if (error)
957 		if_statinc(ifp, if_oerrors);
958 	return error;
959 }
960 
961 static int
962 gre_getsockname(struct socket *so, struct sockaddr *nam)
963 {
964 	return (*so->so_proto->pr_usrreqs->pr_sockaddr)(so, nam);
965 }
966 
967 static int
968 gre_getpeername(struct socket *so, struct sockaddr *nam)
969 {
970 	return (*so->so_proto->pr_usrreqs->pr_peeraddr)(so, nam);
971 }
972 
973 static int
974 gre_getnames(struct socket *so, struct lwp *l, struct sockaddr_storage *src,
975     struct sockaddr_storage *dst)
976 {
977 	struct sockaddr_storage ss;
978 	int rc;
979 
980 	solock(so);
981 	if ((rc = gre_getsockname(so, (struct sockaddr *)&ss)) != 0)
982 		goto out;
983 	*src = ss;
984 
985 	if ((rc = gre_getpeername(so, (struct sockaddr *)&ss)) != 0)
986 		goto out;
987 	*dst = ss;
988 out:
989 	sounlock(so);
990 	return rc;
991 }
992 
993 static void
994 gre_fp_recvloop(void *arg)
995 {
996 	struct gre_softc *sc = arg;
997 
998 	mutex_enter(&sc->sc_mtx);
999 	while (gre_fp_recv(sc))
1000 		;
1001 	mutex_exit(&sc->sc_mtx);
1002 	kthread_exit(0);
1003 }
1004 
1005 static bool
1006 gre_fp_recv(struct gre_softc *sc)
1007 {
1008 	int fd, ofd, rc;
1009 	file_t *fp;
1010 
1011 	fp = sc->sc_fp;
1012 	ofd = sc->sc_fd;
1013 	fd = -1;
1014 
1015 	switch (sc->sc_msg) {
1016 	case GRE_M_STOP:
1017 		cv_signal(&sc->sc_fp_condvar);
1018 		return false;
1019 	case GRE_M_SETFP:
1020 		mutex_exit(&sc->sc_mtx);
1021 		rc = fd_dup(fp, 0, &fd, 0);
1022 		mutex_enter(&sc->sc_mtx);
1023 		if (rc != 0) {
1024 			sc->sc_msg = GRE_M_ERR;
1025 			break;
1026 		}
1027 		/*FALLTHROUGH*/
1028 	case GRE_M_DELFP:
1029 		mutex_exit(&sc->sc_mtx);
1030 		if (ofd != -1 && fd_getfile(ofd) != NULL)
1031 			fd_close(ofd);
1032 		mutex_enter(&sc->sc_mtx);
1033 		sc->sc_fd = fd;
1034 		sc->sc_msg = GRE_M_OK;
1035 		break;
1036 	default:
1037 		gre_fp_wait(sc);
1038 		return true;
1039 	}
1040 	cv_signal(&sc->sc_fp_condvar);
1041 	return true;
1042 }
1043 
1044 static bool
1045 gre_fp_send(struct gre_softc *sc, enum gre_msg msg, file_t *fp)
1046 {
1047 	bool rc;
1048 
1049 	mutex_enter(&sc->sc_mtx);
1050 	while (sc->sc_msg != GRE_M_NONE)
1051 		gre_fp_wait(sc);
1052 	sc->sc_fp = fp;
1053 	sc->sc_msg = msg;
1054 	cv_signal(&sc->sc_fp_condvar);
1055 	while (sc->sc_msg != GRE_M_STOP && sc->sc_msg != GRE_M_OK &&
1056 	            sc->sc_msg != GRE_M_ERR)
1057 		gre_fp_wait(sc);
1058 	rc = (sc->sc_msg != GRE_M_ERR);
1059 	sc->sc_msg = GRE_M_NONE;
1060 	cv_signal(&sc->sc_fp_condvar);
1061 	mutex_exit(&sc->sc_mtx);
1062 	return rc;
1063 }
1064 
1065 static int
1066 gre_ssock(struct ifnet *ifp, struct gre_soparm *sp, int fd)
1067 {
1068 	int error = 0;
1069 	const struct protosw *pr;
1070 	file_t *fp;
1071 	struct gre_softc *sc = ifp->if_softc;
1072 	struct socket *so;
1073 	struct sockaddr_storage dst, src;
1074 
1075 	if ((fp = fd_getfile(fd)) == NULL)
1076 		return EBADF;
1077 	if (fp->f_type != DTYPE_SOCKET) {
1078 		fd_putfile(fd);
1079 		return ENOTSOCK;
1080 	}
1081 
1082 	GRE_DPRINTF(sc, "\n");
1083 
1084 	so = fp->f_socket;
1085 	pr = so->so_proto;
1086 
1087 	GRE_DPRINTF(sc, "type %d, proto %d\n", pr->pr_type, pr->pr_protocol);
1088 
1089 	if ((pr->pr_flags & PR_ATOMIC) == 0 ||
1090 	    (sp->sp_type != 0 && pr->pr_type != sp->sp_type) ||
1091 	    (sp->sp_proto != 0 && pr->pr_protocol != 0 &&
1092 	     pr->pr_protocol != sp->sp_proto)) {
1093 		error = EINVAL;
1094 		goto err;
1095 	}
1096 
1097 	GRE_DPRINTF(sc, "\n");
1098 
1099 	/* check address */
1100 	if ((error = gre_getnames(so, curlwp, &src, &dst)) != 0)
1101 		goto err;
1102 
1103 	GRE_DPRINTF(sc, "\n");
1104 
1105 	if (!gre_fp_send(sc, GRE_M_SETFP, fp)) {
1106 		error = EBUSY;
1107 		goto err;
1108 	}
1109 
1110 	GRE_DPRINTF(sc, "\n");
1111 
1112 	sp->sp_src = src;
1113 	sp->sp_dst = dst;
1114 
1115 	sp->sp_so = so;
1116 
1117 err:
1118 	fd_putfile(fd);
1119 	return error;
1120 }
1121 
1122 static bool
1123 sockaddr_is_anyaddr(const struct sockaddr *sa)
1124 {
1125 	socklen_t anylen, salen;
1126 	const void *anyaddr, *addr;
1127 
1128 	if ((anyaddr = sockaddr_anyaddr(sa, &anylen)) == NULL ||
1129 	    (addr = sockaddr_const_addr(sa, &salen)) == NULL)
1130 		return false;
1131 
1132 	if (salen > anylen)
1133 		return false;
1134 
1135 	return memcmp(anyaddr, addr, MIN(anylen, salen)) == 0;
1136 }
1137 
1138 static bool
1139 gre_is_nullconf(const struct gre_soparm *sp)
1140 {
1141 	return sockaddr_is_anyaddr(sstocsa(&sp->sp_src)) ||
1142 	       sockaddr_is_anyaddr(sstocsa(&sp->sp_dst));
1143 }
1144 
1145 static void
1146 gre_clearconf(struct gre_soparm *sp, bool force)
1147 {
1148 	if (sp->sp_bysock || force) {
1149 		sockaddr_copy(sstosa(&sp->sp_src), sizeof(sp->sp_src),
1150 		    sockaddr_any(sstosa(&sp->sp_src)));
1151 		sockaddr_copy(sstosa(&sp->sp_dst), sizeof(sp->sp_dst),
1152 		    sockaddr_any(sstosa(&sp->sp_dst)));
1153 		sp->sp_bysock = false;
1154 	}
1155 	sp->sp_so = NULL; /* XXX */
1156 }
1157 
1158 static int
1159 gre_ioctl(struct ifnet *ifp, const u_long cmd, void *data)
1160 {
1161 	struct ifreq *ifr;
1162 	struct ifaddr *ifa = (struct ifaddr *)data;
1163 	struct if_laddrreq *lifr = (struct if_laddrreq *)data;
1164 	struct gre_softc *sc = ifp->if_softc;
1165 	struct gre_soparm *sp;
1166 	int fd, error = 0, oproto, otype, s;
1167 	struct gre_soparm sp0;
1168 
1169 	ifr = data;
1170 
1171 	GRE_DPRINTF(sc, "cmd %lu\n", cmd);
1172 
1173 	switch (cmd) {
1174 	case GRESPROTO:
1175 	case GRESADDRD:
1176 	case GRESADDRS:
1177 	case GRESSOCK:
1178 	case GREDSOCK:
1179 		if (kauth_authorize_network(kauth_cred_get(),
1180 		    KAUTH_NETWORK_INTERFACE,
1181 		    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
1182 		    NULL) != 0)
1183 			return EPERM;
1184 		break;
1185 	default:
1186 		break;
1187 	}
1188 
1189 	s = splnet();
1190 
1191 	sp0 = sc->sc_soparm;
1192 	sp0.sp_so = NULL;
1193 	sp = &sp0;
1194 
1195 	GRE_DPRINTF(sc, "\n");
1196 
1197 	switch (cmd) {
1198 	case SIOCINITIFADDR:
1199 		GRE_DPRINTF(sc, "\n");
1200 		if ((ifp->if_flags & IFF_UP) != 0)
1201 			break;
1202 		gre_clearconf(sp, false);
1203 		ifp->if_flags |= IFF_UP;
1204 		ifa->ifa_rtrequest = p2p_rtrequest;
1205 		goto mksocket;
1206 	case SIOCSIFFLAGS:
1207 		if ((error = ifioctl_common(ifp, cmd, data)) != 0)
1208 			break;
1209 		oproto = sp->sp_proto;
1210 		otype = sp->sp_type;
1211 		switch (ifr->ifr_flags & (IFF_LINK0|IFF_LINK2)) {
1212 		case IFF_LINK0|IFF_LINK2:
1213 			sp->sp_proto = IPPROTO_UDP;
1214 			sp->sp_type = SOCK_DGRAM;
1215 			break;
1216 		case IFF_LINK2:
1217 			sp->sp_proto = 0;
1218 			sp->sp_type = 0;
1219 			break;
1220 		case IFF_LINK0:
1221 			sp->sp_proto = IPPROTO_GRE;
1222 			sp->sp_type = SOCK_RAW;
1223 			break;
1224 		default:
1225 			GRE_DPRINTF(sc, "\n");
1226 			error = EINVAL;
1227 			goto out;
1228 		}
1229 		GRE_DPRINTF(sc, "\n");
1230 		gre_clearconf(sp, false);
1231 		if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) ==
1232 		    (IFF_UP|IFF_RUNNING) &&
1233 		    (oproto == sp->sp_proto || sp->sp_proto == 0) &&
1234 		    (otype == sp->sp_type || sp->sp_type == 0))
1235 			break;
1236 		switch (sp->sp_proto) {
1237 		case IPPROTO_UDP:
1238 		case IPPROTO_GRE:
1239 			goto mksocket;
1240 		default:
1241 			break;
1242 		}
1243 		break;
1244 	case SIOCSIFMTU:
1245 		/* XXX determine MTU automatically by probing w/
1246 		 * XXX do-not-fragment packets?
1247 		 */
1248 		if (ifr->ifr_mtu < 576) {
1249 			error = EINVAL;
1250 			break;
1251 		}
1252 		/*FALLTHROUGH*/
1253 	case SIOCGIFMTU:
1254 		if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET)
1255 			error = 0;
1256 		break;
1257 	case SIOCADDMULTI:
1258 	case SIOCDELMULTI:
1259 		if (ifr == NULL) {
1260 			error = EAFNOSUPPORT;
1261 			break;
1262 		}
1263 		switch (ifreq_getaddr(cmd, ifr)->sa_family) {
1264 #ifdef INET
1265 		case AF_INET:
1266 			break;
1267 #endif
1268 #ifdef INET6
1269 		case AF_INET6:
1270 			break;
1271 #endif
1272 		default:
1273 			error = EAFNOSUPPORT;
1274 			break;
1275 		}
1276 		break;
1277 	case GRESPROTO:
1278 		gre_clearconf(sp, false);
1279 		oproto = sp->sp_proto;
1280 		otype = sp->sp_type;
1281 		sp->sp_proto = ifr->ifr_flags;
1282 		switch (sp->sp_proto) {
1283 		case IPPROTO_UDP:
1284 			ifp->if_flags |= IFF_LINK0|IFF_LINK2;
1285 			sp->sp_type = SOCK_DGRAM;
1286 			break;
1287 		case IPPROTO_GRE:
1288 			ifp->if_flags |= IFF_LINK0;
1289 			ifp->if_flags &= ~IFF_LINK2;
1290 			sp->sp_type = SOCK_RAW;
1291 			break;
1292 		case 0:
1293 			ifp->if_flags &= ~IFF_LINK0;
1294 			ifp->if_flags |= IFF_LINK2;
1295 			sp->sp_type = 0;
1296 			break;
1297 		default:
1298 			error = EPROTONOSUPPORT;
1299 			break;
1300 		}
1301 		if ((oproto == sp->sp_proto || sp->sp_proto == 0) &&
1302 		    (otype == sp->sp_type || sp->sp_type == 0))
1303 			break;
1304 		switch (sp->sp_proto) {
1305 		case IPPROTO_UDP:
1306 		case IPPROTO_GRE:
1307 			goto mksocket;
1308 		default:
1309 			break;
1310 		}
1311 		break;
1312 	case GREGPROTO:
1313 		ifr->ifr_flags = sp->sp_proto;
1314 		break;
1315 	case GRESADDRS:
1316 	case GRESADDRD:
1317 		gre_clearconf(sp, false);
1318 		/* set tunnel endpoints and mark interface as up */
1319 		switch (cmd) {
1320 		case GRESADDRS:
1321 			sockaddr_copy(sstosa(&sp->sp_src),
1322 			    sizeof(sp->sp_src), ifreq_getaddr(cmd, ifr));
1323 			break;
1324 		case GRESADDRD:
1325 			sockaddr_copy(sstosa(&sp->sp_dst),
1326 			    sizeof(sp->sp_dst), ifreq_getaddr(cmd, ifr));
1327 			break;
1328 		}
1329 	checkaddr:
1330 		if (sockaddr_any(sstosa(&sp->sp_src)) == NULL ||
1331 		    sockaddr_any(sstosa(&sp->sp_dst)) == NULL) {
1332 			error = EINVAL;
1333 			break;
1334 		}
1335 		/* let gre_socreate() check the rest */
1336 	mksocket:
1337 		GRE_DPRINTF(sc, "\n");
1338 		/* If we're administratively down, or the configuration
1339 		 * is empty, there's no use creating a socket.
1340 		 */
1341 		if ((ifp->if_flags & IFF_UP) == 0 || gre_is_nullconf(sp))
1342 			goto sendconf;
1343 
1344 		GRE_DPRINTF(sc, "\n");
1345 		fd = 0;
1346 		error = gre_socreate(sc, sp, &fd);
1347 		if (error != 0)
1348 			break;
1349 
1350 	setsock:
1351 		GRE_DPRINTF(sc, "\n");
1352 
1353 		error = gre_ssock(ifp, sp, fd);
1354 
1355 		if (cmd != GRESSOCK) {
1356 			GRE_DPRINTF(sc, "\n");
1357 			/* XXX v. dodgy */
1358 			if (fd_getfile(fd) != NULL)
1359 				fd_close(fd);
1360 		}
1361 
1362 		if (error == 0) {
1363 	sendconf:
1364 			GRE_DPRINTF(sc, "\n");
1365 			ifp->if_flags &= ~IFF_RUNNING;
1366 			gre_reconf(sc, sp);
1367 		}
1368 
1369 		break;
1370 	case GREGADDRS:
1371 		ifreq_setaddr(cmd, ifr, sstosa(&sp->sp_src));
1372 		break;
1373 	case GREGADDRD:
1374 		ifreq_setaddr(cmd, ifr, sstosa(&sp->sp_dst));
1375 		break;
1376 	case GREDSOCK:
1377 		GRE_DPRINTF(sc, "\n");
1378 		if (sp->sp_bysock)
1379 			ifp->if_flags &= ~IFF_UP;
1380 		gre_clearconf(sp, false);
1381 		goto mksocket;
1382 	case GRESSOCK:
1383 		GRE_DPRINTF(sc, "\n");
1384 		gre_clearconf(sp, true);
1385 		fd = (int)ifr->ifr_value;
1386 		sp->sp_bysock = true;
1387 		ifp->if_flags |= IFF_UP;
1388 		goto setsock;
1389 	case SIOCSLIFPHYADDR:
1390 		GRE_DPRINTF(sc, "\n");
1391 		if (lifr->addr.ss_family != lifr->dstaddr.ss_family) {
1392 			error = EAFNOSUPPORT;
1393 			break;
1394 		}
1395 		sockaddr_copy(sstosa(&sp->sp_src), sizeof(sp->sp_src),
1396 		    sstosa(&lifr->addr));
1397 		sockaddr_copy(sstosa(&sp->sp_dst), sizeof(sp->sp_dst),
1398 		    sstosa(&lifr->dstaddr));
1399 		GRE_DPRINTF(sc, "\n");
1400 		goto checkaddr;
1401 	case SIOCDIFPHYADDR:
1402 		GRE_DPRINTF(sc, "\n");
1403 		gre_clearconf(sp, true);
1404 		ifp->if_flags &= ~IFF_UP;
1405 		goto mksocket;
1406 	case SIOCGLIFPHYADDR:
1407 		GRE_DPRINTF(sc, "\n");
1408 		if (gre_is_nullconf(sp)) {
1409 			error = EADDRNOTAVAIL;
1410 			break;
1411 		}
1412 		sockaddr_copy(sstosa(&lifr->addr), sizeof(lifr->addr),
1413 		    sstosa(&sp->sp_src));
1414 		sockaddr_copy(sstosa(&lifr->dstaddr), sizeof(lifr->dstaddr),
1415 		    sstosa(&sp->sp_dst));
1416 		GRE_DPRINTF(sc, "\n");
1417 		break;
1418 	default:
1419 		error = ifioctl_common(ifp, cmd, data);
1420 		break;
1421 	}
1422 out:
1423 	GRE_DPRINTF(sc, "\n");
1424 	splx(s);
1425 	return error;
1426 }
1427 
1428 /* ARGSUSED */
1429 void
1430 greattach(int count)
1431 {
1432 
1433 	/*
1434 	 * Nothing to do here, initialization is handled by the
1435 	 * module initialization code in greinit() below.
1436 	 */
1437 }
1438 
1439 static void
1440 greinit(void)
1441 {
1442 	if_clone_attach(&gre_cloner);
1443 }
1444 
1445 static int
1446 gredetach(void)
1447 {
1448 	int error = 0;
1449 
1450 	if (gre_count != 0)
1451 		error = EBUSY;
1452 
1453 	if (error == 0)
1454 		if_clone_detach(&gre_cloner);
1455 
1456 	return error;
1457 }
1458 
1459 /*
1460  * Module infrastructure
1461  */
1462 #include "if_module.h"
1463 
1464 IF_MODULE(MODULE_CLASS_DRIVER, gre, NULL)
1465