xref: /netbsd-src/sys/net/if_gre.c (revision 404fbe5fb94ca1e054339640cabb2801ce52dd30)
1 /*	$NetBSD: if_gre.c,v 1.139 2008/11/07 00:20:13 dyoung 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 1.139 2008/11/07 00:20:13 dyoung Exp $");
49 
50 #include "opt_gre.h"
51 #include "opt_inet.h"
52 #include "bpfilter.h"
53 
54 #ifdef INET
55 #include <sys/param.h>
56 #include <sys/file.h>
57 #include <sys/filedesc.h>
58 #include <sys/malloc.h>
59 #include <sys/mallocvar.h>
60 #include <sys/mbuf.h>
61 #include <sys/proc.h>
62 #include <sys/domain.h>
63 #include <sys/protosw.h>
64 #include <sys/socket.h>
65 #include <sys/socketvar.h>
66 #include <sys/ioctl.h>
67 #include <sys/queue.h>
68 #include <sys/intr.h>
69 #if __NetBSD__
70 #include <sys/systm.h>
71 #include <sys/sysctl.h>
72 #include <sys/kauth.h>
73 #endif
74 
75 #include <sys/kernel.h>
76 #include <sys/mutex.h>
77 #include <sys/condvar.h>
78 #include <sys/kthread.h>
79 
80 #include <sys/cpu.h>
81 
82 #include <net/ethertypes.h>
83 #include <net/if.h>
84 #include <net/if_types.h>
85 #include <net/netisr.h>
86 #include <net/route.h>
87 
88 #ifdef INET
89 #include <netinet/in.h>
90 #include <netinet/in_systm.h>
91 #include <netinet/in_var.h>
92 #include <netinet/ip.h>
93 #include <netinet/ip_var.h>
94 #else
95 #error "Huh? if_gre without inet?"
96 #endif
97 
98 
99 #ifdef NETATALK
100 #include <netatalk/at.h>
101 #include <netatalk/at_var.h>
102 #include <netatalk/at_extern.h>
103 #endif
104 
105 #if NBPFILTER > 0
106 #include <sys/time.h>
107 #include <net/bpf.h>
108 #endif
109 
110 #include <net/if_gre.h>
111 
112 #include <compat/sys/socket.h>
113 #include <compat/sys/sockio.h>
114 /*
115  * It is not easy to calculate the right value for a GRE MTU.
116  * We leave this task to the admin and use the same default that
117  * other vendors use.
118  */
119 #define GREMTU 1476
120 
121 #ifdef GRE_DEBUG
122 int gre_debug = 0;
123 #define	GRE_DPRINTF(__sc, ...)						\
124 	do {								\
125 		if (__predict_false(gre_debug ||			\
126 		    ((__sc)->sc_if.if_flags & IFF_DEBUG) != 0)) {	\
127 			printf("%s.%d: ", __func__, __LINE__);		\
128 			printf(__VA_ARGS__);				\
129 		}							\
130 	} while (/*CONSTCOND*/0)
131 #else
132 #define	GRE_DPRINTF(__sc, __fmt, ...)	do { } while (/*CONSTCOND*/0)
133 #endif /* GRE_DEBUG */
134 
135 int ip_gre_ttl = GRE_TTL;
136 MALLOC_DEFINE(M_GRE_BUFQ, "gre_bufq", "gre mbuf queue");
137 
138 static int gre_clone_create(struct if_clone *, int);
139 static int gre_clone_destroy(struct ifnet *);
140 
141 static struct if_clone gre_cloner =
142     IF_CLONE_INITIALIZER("gre", gre_clone_create, gre_clone_destroy);
143 
144 static int gre_input(struct gre_softc *, struct mbuf *, int,
145     const struct gre_h *);
146 static bool gre_is_nullconf(const struct gre_soparm *);
147 static int gre_output(struct ifnet *, struct mbuf *,
148 			   const struct sockaddr *, struct rtentry *);
149 static int gre_ioctl(struct ifnet *, u_long, void *);
150 static int gre_getsockname(struct socket *, struct mbuf *, struct lwp *);
151 static int gre_getpeername(struct socket *, struct mbuf *, struct lwp *);
152 static int gre_getnames(struct socket *, struct lwp *,
153     struct sockaddr_storage *, struct sockaddr_storage *);
154 static void gre_clearconf(struct gre_soparm *, bool);
155 static int gre_soreceive(struct socket *, struct mbuf **);
156 static int gre_sosend(struct socket *, struct mbuf *);
157 static struct socket *gre_reconf(struct gre_softc *, const struct gre_soparm *);
158 
159 static bool gre_fp_send(struct gre_softc *, enum gre_msg, file_t *);
160 static bool gre_fp_recv(struct gre_softc *);
161 static void gre_fp_recvloop(void *);
162 
163 static int
164 nearest_pow2(size_t len0)
165 {
166 	size_t len, mid;
167 
168 	if (len0 == 0)
169 		return 1;
170 
171 	for (len = len0; (len & (len - 1)) != 0; len &= len - 1)
172 		;
173 
174 	mid = len | (len >> 1);
175 
176 	/* avoid overflow */
177 	if ((len << 1) < len)
178 		return len;
179 	if (len0 >= mid)
180 		return len << 1;
181 	return len;
182 }
183 
184 static struct gre_bufq *
185 gre_bufq_init(struct gre_bufq *bq, size_t len0)
186 {
187 	size_t len;
188 
189 	len = nearest_pow2(len0);
190 
191 	memset(bq, 0, sizeof(*bq));
192 	bq->bq_buf = malloc(len * sizeof(struct mbuf *), M_GRE_BUFQ, M_WAITOK);
193 	bq->bq_len = len;
194 	bq->bq_lenmask = len - 1;
195 
196 	return bq;
197 }
198 
199 static bool
200 gre_bufq_empty(struct gre_bufq *bq)
201 {
202 	return bq->bq_prodidx == bq->bq_considx;
203 }
204 
205 static struct mbuf *
206 gre_bufq_dequeue(struct gre_bufq *bq)
207 {
208 	struct mbuf *m;
209 
210 	if (gre_bufq_empty(bq))
211 		return NULL;
212 
213 	m = bq->bq_buf[bq->bq_considx];
214 	bq->bq_considx = (bq->bq_considx + 1) & bq->bq_lenmask;
215 
216 	return m;
217 }
218 
219 static void
220 gre_bufq_purge(struct gre_bufq *bq)
221 {
222 	struct mbuf *m;
223 
224 	while ((m = gre_bufq_dequeue(bq)) != NULL)
225 		m_freem(m);
226 }
227 
228 static int
229 gre_bufq_enqueue(struct gre_bufq *bq, struct mbuf *m)
230 {
231 	int next;
232 
233 	next = (bq->bq_prodidx + 1) & bq->bq_lenmask;
234 
235 	if (next == bq->bq_considx) {
236 		bq->bq_drops++;
237 		return ENOBUFS;
238 	}
239 
240 	bq->bq_buf[bq->bq_prodidx] = m;
241 	bq->bq_prodidx = next;
242 	return 0;
243 }
244 
245 static void
246 greintr(void *arg)
247 {
248 	struct gre_softc *sc = (struct gre_softc *)arg;
249 	struct socket *so = sc->sc_soparm.sp_so;
250 	int rc;
251 	struct mbuf *m;
252 
253 	KASSERT(so != NULL);
254 
255 	sc->sc_send_ev.ev_count++;
256 	GRE_DPRINTF(sc, "enter\n");
257 	while ((m = gre_bufq_dequeue(&sc->sc_snd)) != NULL) {
258 		/* XXX handle ENOBUFS? */
259 		if ((rc = gre_sosend(so, m)) != 0)
260 			GRE_DPRINTF(sc, "gre_sosend failed %d\n", rc);
261 	}
262 }
263 
264 /* Caller must hold sc->sc_mtx. */
265 static void
266 gre_wait(struct gre_softc *sc)
267 {
268 	sc->sc_waiters++;
269 	cv_wait(&sc->sc_condvar, &sc->sc_mtx);
270 	sc->sc_waiters--;
271 }
272 
273 static void
274 gre_fp_wait(struct gre_softc *sc)
275 {
276 	sc->sc_fp_waiters++;
277 	cv_wait(&sc->sc_fp_condvar, &sc->sc_mtx);
278 	sc->sc_fp_waiters--;
279 }
280 
281 static void
282 gre_evcnt_detach(struct gre_softc *sc)
283 {
284 	evcnt_detach(&sc->sc_unsupp_ev);
285 	evcnt_detach(&sc->sc_pullup_ev);
286 	evcnt_detach(&sc->sc_error_ev);
287 	evcnt_detach(&sc->sc_block_ev);
288 	evcnt_detach(&sc->sc_recv_ev);
289 
290 	evcnt_detach(&sc->sc_oflow_ev);
291 	evcnt_detach(&sc->sc_send_ev);
292 }
293 
294 static void
295 gre_evcnt_attach(struct gre_softc *sc)
296 {
297 	evcnt_attach_dynamic(&sc->sc_recv_ev, EVCNT_TYPE_MISC,
298 	    NULL, sc->sc_if.if_xname, "recv");
299 	evcnt_attach_dynamic(&sc->sc_block_ev, EVCNT_TYPE_MISC,
300 	    &sc->sc_recv_ev, sc->sc_if.if_xname, "would block");
301 	evcnt_attach_dynamic(&sc->sc_error_ev, EVCNT_TYPE_MISC,
302 	    &sc->sc_recv_ev, sc->sc_if.if_xname, "error");
303 	evcnt_attach_dynamic(&sc->sc_pullup_ev, EVCNT_TYPE_MISC,
304 	    &sc->sc_recv_ev, sc->sc_if.if_xname, "pullup failed");
305 	evcnt_attach_dynamic(&sc->sc_unsupp_ev, EVCNT_TYPE_MISC,
306 	    &sc->sc_recv_ev, sc->sc_if.if_xname, "unsupported");
307 
308 	evcnt_attach_dynamic(&sc->sc_send_ev, EVCNT_TYPE_MISC,
309 	    NULL, sc->sc_if.if_xname, "send");
310 	evcnt_attach_dynamic(&sc->sc_oflow_ev, EVCNT_TYPE_MISC,
311 	    &sc->sc_send_ev, sc->sc_if.if_xname, "overflow");
312 }
313 
314 static int
315 gre_clone_create(struct if_clone *ifc, int unit)
316 {
317 	int rc;
318 	struct gre_softc *sc;
319 	struct gre_soparm *sp;
320 
321 	sc = malloc(sizeof(struct gre_softc), M_DEVBUF, M_WAITOK|M_ZERO);
322 	mutex_init(&sc->sc_mtx, MUTEX_DRIVER, IPL_SOFTNET);
323 	cv_init(&sc->sc_condvar, "gre wait");
324 	cv_init(&sc->sc_fp_condvar, "gre fp");
325 
326 	if_initname(&sc->sc_if, ifc->ifc_name, unit);
327 	sc->sc_if.if_softc = sc;
328 	sc->sc_if.if_type = IFT_TUNNEL;
329 	sc->sc_if.if_addrlen = 0;
330 	sc->sc_if.if_hdrlen = sizeof(struct ip) + sizeof(struct gre_h);
331 	sc->sc_if.if_dlt = DLT_NULL;
332 	sc->sc_if.if_mtu = GREMTU;
333 	sc->sc_if.if_flags = IFF_POINTOPOINT|IFF_MULTICAST;
334 	sc->sc_if.if_output = gre_output;
335 	sc->sc_if.if_ioctl = gre_ioctl;
336 	sp = &sc->sc_soparm;
337 	sockaddr_copy(sstosa(&sp->sp_dst), sizeof(sp->sp_dst),
338 	    sintocsa(&in_any));
339 	sockaddr_copy(sstosa(&sp->sp_src), sizeof(sp->sp_src),
340 	    sintocsa(&in_any));
341 	sp->sp_proto = IPPROTO_GRE;
342 	sp->sp_type = SOCK_RAW;
343 
344 	sc->sc_fd = -1;
345 
346 	rc = kthread_create(PRI_NONE, KTHREAD_MPSAFE, NULL, gre_fp_recvloop, sc,
347 	    NULL, sc->sc_if.if_xname);
348 
349 	if (rc != 0)
350 		return -1;
351 
352 	gre_evcnt_attach(sc);
353 
354 	gre_bufq_init(&sc->sc_snd, 17);
355 	sc->sc_if.if_flags |= IFF_LINK0;
356 	if_attach(&sc->sc_if);
357 	if_alloc_sadl(&sc->sc_if);
358 #if NBPFILTER > 0
359 	bpfattach(&sc->sc_if, DLT_NULL, sizeof(uint32_t));
360 #endif
361 	sc->sc_state = GRE_S_IDLE;
362 	return 0;
363 }
364 
365 static int
366 gre_clone_destroy(struct ifnet *ifp)
367 {
368 	int s;
369 	struct gre_softc *sc = ifp->if_softc;
370 
371 	GRE_DPRINTF(sc, "\n");
372 
373 #if NBPFILTER > 0
374 	bpfdetach(ifp);
375 #endif
376 	s = splnet();
377 	if_detach(ifp);
378 
379 	/* Some LWPs may still wait in gre_ioctl_lock(), however,
380 	 * no new LWP will enter gre_ioctl_lock(), because ifunit()
381 	 * cannot locate the interface any longer.
382 	 */
383 	mutex_enter(&sc->sc_mtx);
384 	GRE_DPRINTF(sc, "\n");
385 	while (sc->sc_state != GRE_S_IDLE)
386 		gre_wait(sc);
387 	GRE_DPRINTF(sc, "\n");
388 	sc->sc_state = GRE_S_DIE;
389 	cv_broadcast(&sc->sc_condvar);
390 	while (sc->sc_waiters > 0)
391 		cv_wait(&sc->sc_condvar, &sc->sc_mtx);
392 	/* At this point, no other LWP will access the gre_softc, so
393 	 * we can release the mutex.
394 	 */
395 	mutex_exit(&sc->sc_mtx);
396 	GRE_DPRINTF(sc, "\n");
397 	/* Note that we must not hold the mutex while we call gre_reconf(). */
398 	gre_reconf(sc, NULL);
399 
400 	mutex_enter(&sc->sc_mtx);
401 	sc->sc_msg = GRE_M_STOP;
402 	cv_signal(&sc->sc_fp_condvar);
403 	while (sc->sc_fp_waiters > 0)
404 		cv_wait(&sc->sc_fp_condvar, &sc->sc_mtx);
405 	mutex_exit(&sc->sc_mtx);
406 
407 	splx(s);
408 
409 	cv_destroy(&sc->sc_condvar);
410 	cv_destroy(&sc->sc_fp_condvar);
411 	mutex_destroy(&sc->sc_mtx);
412 	gre_evcnt_detach(sc);
413 	free(sc, M_DEVBUF);
414 
415 	return 0;
416 }
417 
418 static void
419 gre_receive(struct socket *so, void *arg, int waitflag)
420 {
421 	struct gre_softc *sc = (struct gre_softc *)arg;
422 	int rc;
423 	const struct gre_h *gh;
424 	struct mbuf *m;
425 
426 	GRE_DPRINTF(sc, "enter\n");
427 
428 	sc->sc_recv_ev.ev_count++;
429 
430 	rc = gre_soreceive(so, &m);
431 	/* TBD Back off if ECONNREFUSED (indicates
432 	 * ICMP Port Unreachable)?
433 	 */
434 	if (rc == EWOULDBLOCK) {
435 		GRE_DPRINTF(sc, "EWOULDBLOCK\n");
436 		sc->sc_block_ev.ev_count++;
437 		return;
438 	} else if (rc != 0 || m == NULL) {
439 		GRE_DPRINTF(sc, "%s: rc %d m %p\n",
440 		    sc->sc_if.if_xname, rc, (void *)m);
441 		sc->sc_error_ev.ev_count++;
442 		return;
443 	}
444 	if (m->m_len < sizeof(*gh) && (m = m_pullup(m, sizeof(*gh))) == NULL) {
445 		GRE_DPRINTF(sc, "m_pullup failed\n");
446 		sc->sc_pullup_ev.ev_count++;
447 		return;
448 	}
449 	gh = mtod(m, const struct gre_h *);
450 
451 	if (gre_input(sc, m, 0, gh) == 0) {
452 		sc->sc_unsupp_ev.ev_count++;
453 		GRE_DPRINTF(sc, "dropping unsupported\n");
454 		m_freem(m);
455 	}
456 }
457 
458 static void
459 gre_upcall_add(struct socket *so, void *arg)
460 {
461 	/* XXX What if the kernel already set an upcall? */
462 	KASSERT((so->so_rcv.sb_flags & SB_UPCALL) == 0);
463 	so->so_upcallarg = arg;
464 	so->so_upcall = gre_receive;
465 	so->so_rcv.sb_flags |= SB_UPCALL;
466 }
467 
468 static void
469 gre_upcall_remove(struct socket *so)
470 {
471 	so->so_rcv.sb_flags &= ~SB_UPCALL;
472 	so->so_upcallarg = NULL;
473 	so->so_upcall = NULL;
474 }
475 
476 static int
477 gre_socreate(struct gre_softc *sc, const struct gre_soparm *sp, int *fdout)
478 {
479 	const struct protosw *pr;
480 	int fd, rc;
481 	struct mbuf *m;
482 	struct sockaddr *sa;
483 	struct socket *so;
484 	sa_family_t af;
485 	int val;
486 
487 	GRE_DPRINTF(sc, "enter\n");
488 
489 	af = sp->sp_src.ss_family;
490 	rc = fsocreate(af, NULL, sp->sp_type, sp->sp_proto, curlwp, &fd);
491 	if (rc != 0) {
492 		GRE_DPRINTF(sc, "fsocreate failed\n");
493 		return rc;
494 	}
495 
496 	if ((rc = fd_getsock(fd, &so)) != 0)
497 		return rc;
498 
499 	if ((m = getsombuf(so, MT_SONAME)) == NULL) {
500 		rc = ENOBUFS;
501 		goto out;
502 	}
503 	sa = mtod(m, struct sockaddr *);
504 	sockaddr_copy(sa, MIN(MLEN, sizeof(sp->sp_src)), sstocsa(&sp->sp_src));
505 	m->m_len = sp->sp_src.ss_len;
506 
507 	if ((rc = sobind(so, m, curlwp)) != 0) {
508 		GRE_DPRINTF(sc, "sobind failed\n");
509 		goto out;
510 	}
511 
512 	sockaddr_copy(sa, MIN(MLEN, sizeof(sp->sp_dst)), sstocsa(&sp->sp_dst));
513 	m->m_len = sp->sp_dst.ss_len;
514 
515 	solock(so);
516 	if ((rc = soconnect(so, m, curlwp)) != 0) {
517 		GRE_DPRINTF(sc, "soconnect failed\n");
518 		sounlock(so);
519 		goto out;
520 	}
521 	sounlock(so);
522 
523 	m = NULL;
524 
525 	/* XXX convert to a (new) SOL_SOCKET call */
526   	pr = so->so_proto;
527   	KASSERT(pr != NULL);
528  	rc = so_setsockopt(curlwp, so, IPPROTO_IP, IP_TTL,
529 	    &ip_gre_ttl, sizeof(ip_gre_ttl));
530   	if (rc != 0) {
531  		GRE_DPRINTF(sc, "so_setsockopt ttl failed\n");
532   		rc = 0;
533   	}
534  	val = 1;
535  	rc = so_setsockopt(curlwp, so, SOL_SOCKET, SO_NOHEADER,
536 	    &val, sizeof(val));
537   	if (rc != 0) {
538  		GRE_DPRINTF(sc, "so_setsockopt SO_NOHEADER failed\n");
539 		rc = 0;
540 	}
541 out:
542 	m_freem(m);
543 
544 	if (rc != 0)
545 		fd_close(fd);
546 	else  {
547 		fd_putfile(fd);
548 		*fdout = fd;
549 	}
550 
551 	return rc;
552 }
553 
554 static int
555 gre_sosend(struct socket *so, struct mbuf *top)
556 {
557 	struct mbuf	**mp;
558 	struct proc	*p;
559 	long		space, resid;
560 	int		error;
561 	struct lwp * const l = curlwp;
562 
563 	p = l->l_proc;
564 
565 	resid = top->m_pkthdr.len;
566 	if (p)
567 		l->l_ru.ru_msgsnd++;
568 #define	snderr(errno)	{ error = errno; goto release; }
569 
570 	solock(so);
571 	if ((error = sblock(&so->so_snd, M_NOWAIT)) != 0)
572 		goto out;
573 	if (so->so_state & SS_CANTSENDMORE)
574 		snderr(EPIPE);
575 	if (so->so_error) {
576 		error = so->so_error;
577 		so->so_error = 0;
578 		goto release;
579 	}
580 	if ((so->so_state & SS_ISCONNECTED) == 0) {
581 		if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
582 			if ((so->so_state & SS_ISCONFIRMING) == 0)
583 				snderr(ENOTCONN);
584 		} else
585 			snderr(EDESTADDRREQ);
586 	}
587 	space = sbspace(&so->so_snd);
588 	if (resid > so->so_snd.sb_hiwat)
589 		snderr(EMSGSIZE);
590 	if (space < resid)
591 		snderr(EWOULDBLOCK);
592 	mp = &top;
593 	/*
594 	 * Data is prepackaged in "top".
595 	 */
596 	if (so->so_state & SS_CANTSENDMORE)
597 		snderr(EPIPE);
598 	error = (*so->so_proto->pr_usrreq)(so, PRU_SEND, top, NULL, NULL, l);
599 	top = NULL;
600 	mp = &top;
601  release:
602 	sbunlock(&so->so_snd);
603  out:
604  	sounlock(so);
605 	if (top != NULL)
606 		m_freem(top);
607 	return error;
608 }
609 
610 /* This is a stripped-down version of soreceive() that will never
611  * block.  It will support SOCK_DGRAM sockets.  It may also support
612  * SOCK_SEQPACKET sockets.
613  */
614 static int
615 gre_soreceive(struct socket *so, struct mbuf **mp0)
616 {
617 	struct mbuf *m, **mp;
618 	int flags, len, error, type;
619 	const struct protosw	*pr;
620 	struct mbuf *nextrecord;
621 
622 	KASSERT(mp0 != NULL);
623 
624 	flags = MSG_DONTWAIT;
625 	pr = so->so_proto;
626 	mp = mp0;
627 	type = 0;
628 
629 	*mp = NULL;
630 
631 	KASSERT(pr->pr_flags & PR_ATOMIC);
632 
633 	if (so->so_state & SS_ISCONFIRMING)
634 		(*pr->pr_usrreq)(so, PRU_RCVD, NULL, NULL, NULL, curlwp);
635  restart:
636 	if ((error = sblock(&so->so_rcv, M_NOWAIT)) != 0) {
637 		return error;
638 	}
639 	m = so->so_rcv.sb_mb;
640 	/*
641 	 * If we have less data than requested, do not block awaiting more.
642 	 */
643 	if (m == NULL) {
644 #ifdef DIAGNOSTIC
645 		if (so->so_rcv.sb_cc)
646 			panic("receive 1");
647 #endif
648 		if (so->so_error) {
649 			error = so->so_error;
650 			so->so_error = 0;
651 		} else if (so->so_state & SS_CANTRCVMORE)
652 			;
653 		else if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0
654 		      && (so->so_proto->pr_flags & PR_CONNREQUIRED))
655 			error = ENOTCONN;
656 		else
657 			error = EWOULDBLOCK;
658 		goto release;
659 	}
660 	/*
661 	 * On entry here, m points to the first record of the socket buffer.
662 	 * While we process the initial mbufs containing address and control
663 	 * info, we save a copy of m->m_nextpkt into nextrecord.
664 	 */
665 	if (curlwp != NULL)
666 		curlwp->l_ru.ru_msgrcv++;
667 	KASSERT(m == so->so_rcv.sb_mb);
668 	SBLASTRECORDCHK(&so->so_rcv, "soreceive 1");
669 	SBLASTMBUFCHK(&so->so_rcv, "soreceive 1");
670 	nextrecord = m->m_nextpkt;
671 	if (pr->pr_flags & PR_ADDR) {
672 #ifdef DIAGNOSTIC
673 		if (m->m_type != MT_SONAME)
674 			panic("receive 1a");
675 #endif
676 		sbfree(&so->so_rcv, m);
677 		MFREE(m, so->so_rcv.sb_mb);
678 		m = so->so_rcv.sb_mb;
679 	}
680 	while (m != NULL && m->m_type == MT_CONTROL && error == 0) {
681 		sbfree(&so->so_rcv, m);
682 		/*
683 		 * Dispose of any SCM_RIGHTS message that went
684 		 * through the read path rather than recv.
685 		 */
686 		if (pr->pr_domain->dom_dispose &&
687 		    mtod(m, struct cmsghdr *)->cmsg_type == SCM_RIGHTS)
688 			(*pr->pr_domain->dom_dispose)(m);
689 		MFREE(m, so->so_rcv.sb_mb);
690 		m = so->so_rcv.sb_mb;
691 	}
692 
693 	/*
694 	 * If m is non-NULL, we have some data to read.  From now on,
695 	 * make sure to keep sb_lastrecord consistent when working on
696 	 * the last packet on the chain (nextrecord == NULL) and we
697 	 * change m->m_nextpkt.
698 	 */
699 	if (m != NULL) {
700 		m->m_nextpkt = nextrecord;
701 		/*
702 		 * If nextrecord == NULL (this is a single chain),
703 		 * then sb_lastrecord may not be valid here if m
704 		 * was changed earlier.
705 		 */
706 		if (nextrecord == NULL) {
707 			KASSERT(so->so_rcv.sb_mb == m);
708 			so->so_rcv.sb_lastrecord = m;
709 		}
710 		type = m->m_type;
711 		if (type == MT_OOBDATA)
712 			flags |= MSG_OOB;
713 	} else {
714 		KASSERT(so->so_rcv.sb_mb == m);
715 		so->so_rcv.sb_mb = nextrecord;
716 		SB_EMPTY_FIXUP(&so->so_rcv);
717 	}
718 	SBLASTRECORDCHK(&so->so_rcv, "soreceive 2");
719 	SBLASTMBUFCHK(&so->so_rcv, "soreceive 2");
720 
721 	while (m != NULL) {
722 		if (m->m_type == MT_OOBDATA) {
723 			if (type != MT_OOBDATA)
724 				break;
725 		} else if (type == MT_OOBDATA)
726 			break;
727 #ifdef DIAGNOSTIC
728 		else if (m->m_type != MT_DATA && m->m_type != MT_HEADER)
729 			panic("receive 3");
730 #endif
731 		so->so_state &= ~SS_RCVATMARK;
732 		if (so->so_oobmark != 0 && so->so_oobmark < m->m_len)
733 			break;
734 		len = m->m_len;
735 		/*
736 		 * mp is set, just pass back the mbufs.
737 		 * Sockbuf must be consistent here (points to current mbuf,
738 		 * it points to next record) when we drop priority;
739 		 * we must note any additions to the sockbuf when we
740 		 * block interrupts again.
741 		 */
742 		if (m->m_flags & M_EOR)
743 			flags |= MSG_EOR;
744 		nextrecord = m->m_nextpkt;
745 		sbfree(&so->so_rcv, m);
746 		*mp = m;
747 		mp = &m->m_next;
748 		so->so_rcv.sb_mb = m = m->m_next;
749 		*mp = NULL;
750 		/*
751 		 * If m != NULL, we also know that
752 		 * so->so_rcv.sb_mb != NULL.
753 		 */
754 		KASSERT(so->so_rcv.sb_mb == m);
755 		if (m) {
756 			m->m_nextpkt = nextrecord;
757 			if (nextrecord == NULL)
758 				so->so_rcv.sb_lastrecord = m;
759 		} else {
760 			so->so_rcv.sb_mb = nextrecord;
761 			SB_EMPTY_FIXUP(&so->so_rcv);
762 		}
763 		SBLASTRECORDCHK(&so->so_rcv, "soreceive 3");
764 		SBLASTMBUFCHK(&so->so_rcv, "soreceive 3");
765 		if (so->so_oobmark) {
766 			so->so_oobmark -= len;
767 			if (so->so_oobmark == 0) {
768 				so->so_state |= SS_RCVATMARK;
769 				break;
770 			}
771 		}
772 		if (flags & MSG_EOR)
773 			break;
774 	}
775 
776 	if (m != NULL) {
777 		m_freem(*mp);
778 		*mp = NULL;
779 		error = ENOMEM;
780 		(void) sbdroprecord(&so->so_rcv);
781 	} else {
782 		/*
783 		 * First part is an inline SB_EMPTY_FIXUP().  Second
784 		 * part makes sure sb_lastrecord is up-to-date if
785 		 * there is still data in the socket buffer.
786 		 */
787 		so->so_rcv.sb_mb = nextrecord;
788 		if (so->so_rcv.sb_mb == NULL) {
789 			so->so_rcv.sb_mbtail = NULL;
790 			so->so_rcv.sb_lastrecord = NULL;
791 		} else if (nextrecord->m_nextpkt == NULL)
792 			so->so_rcv.sb_lastrecord = nextrecord;
793 	}
794 	SBLASTRECORDCHK(&so->so_rcv, "soreceive 4");
795 	SBLASTMBUFCHK(&so->so_rcv, "soreceive 4");
796 	if (pr->pr_flags & PR_WANTRCVD && so->so_pcb)
797 		(*pr->pr_usrreq)(so, PRU_RCVD, NULL,
798 		    (struct mbuf *)(long)flags, NULL, curlwp);
799 	if (*mp0 == NULL && (flags & MSG_EOR) == 0 &&
800 	    (so->so_state & SS_CANTRCVMORE) == 0) {
801 		sbunlock(&so->so_rcv);
802 		goto restart;
803 	}
804 
805  release:
806 	sbunlock(&so->so_rcv);
807 	return error;
808 }
809 
810 static struct socket *
811 gre_reconf(struct gre_softc *sc, const struct gre_soparm *newsoparm)
812 {
813 	struct ifnet *ifp = &sc->sc_if;
814 
815 	GRE_DPRINTF(sc, "enter\n");
816 
817 shutdown:
818 	if (sc->sc_soparm.sp_so != NULL) {
819 		GRE_DPRINTF(sc, "\n");
820 		gre_upcall_remove(sc->sc_soparm.sp_so);
821 		softint_disestablish(sc->sc_si);
822 		sc->sc_si = NULL;
823 		gre_fp_send(sc, GRE_M_DELFP, NULL);
824 		gre_clearconf(&sc->sc_soparm, false);
825 	}
826 
827 	if (newsoparm != NULL) {
828 		GRE_DPRINTF(sc, "\n");
829 		sc->sc_soparm = *newsoparm;
830 		newsoparm = NULL;
831 	}
832 
833 	if (sc->sc_soparm.sp_so != NULL) {
834 		GRE_DPRINTF(sc, "\n");
835 		sc->sc_si = softint_establish(SOFTINT_NET, greintr, sc);
836 		gre_upcall_add(sc->sc_soparm.sp_so, sc);
837 		if ((ifp->if_flags & IFF_UP) == 0) {
838 			GRE_DPRINTF(sc, "down\n");
839 			goto shutdown;
840 		}
841 	}
842 
843 	GRE_DPRINTF(sc, "\n");
844 	if (sc->sc_soparm.sp_so != NULL)
845 		sc->sc_if.if_flags |= IFF_RUNNING;
846 	else {
847 		gre_bufq_purge(&sc->sc_snd);
848 		sc->sc_if.if_flags &= ~IFF_RUNNING;
849 	}
850 	return sc->sc_soparm.sp_so;
851 }
852 
853 static int
854 gre_input(struct gre_softc *sc, struct mbuf *m, int hlen,
855     const struct gre_h *gh)
856 {
857 	uint16_t flags;
858 	uint32_t af;		/* af passed to BPF tap */
859 	int isr, s;
860 	struct ifqueue *ifq;
861 
862 	sc->sc_if.if_ipackets++;
863 	sc->sc_if.if_ibytes += m->m_pkthdr.len;
864 
865 	hlen += sizeof(struct gre_h);
866 
867 	/* process GRE flags as packet can be of variable len */
868 	flags = ntohs(gh->flags);
869 
870 	/* Checksum & Offset are present */
871 	if ((flags & GRE_CP) | (flags & GRE_RP))
872 		hlen += 4;
873 	/* We don't support routing fields (variable length) */
874 	if (flags & GRE_RP) {
875 		sc->sc_if.if_ierrors++;
876 		return 0;
877 	}
878 	if (flags & GRE_KP)
879 		hlen += 4;
880 	if (flags & GRE_SP)
881 		hlen += 4;
882 
883 	switch (ntohs(gh->ptype)) { /* ethertypes */
884 	case ETHERTYPE_IP:
885 		ifq = &ipintrq;
886 		isr = NETISR_IP;
887 		af = AF_INET;
888 		break;
889 #ifdef NETATALK
890 	case ETHERTYPE_ATALK:
891 		ifq = &atintrq1;
892 		isr = NETISR_ATALK;
893 		af = AF_APPLETALK;
894 		break;
895 #endif
896 #ifdef INET6
897 	case ETHERTYPE_IPV6:
898 		ifq = &ip6intrq;
899 		isr = NETISR_IPV6;
900 		af = AF_INET6;
901 		break;
902 #endif
903 	default:	   /* others not yet supported */
904 		GRE_DPRINTF(sc, "unhandled ethertype 0x%04x\n",
905 		    ntohs(gh->ptype));
906 		sc->sc_if.if_noproto++;
907 		return 0;
908 	}
909 
910 	if (hlen > m->m_pkthdr.len) {
911 		m_freem(m);
912 		sc->sc_if.if_ierrors++;
913 		return EINVAL;
914 	}
915 	m_adj(m, hlen);
916 
917 #if NBPFILTER > 0
918 	if (sc->sc_if.if_bpf != NULL)
919 		bpf_mtap_af(sc->sc_if.if_bpf, af, m);
920 #endif /*NBPFILTER > 0*/
921 
922 	m->m_pkthdr.rcvif = &sc->sc_if;
923 
924 	s = splnet();
925 	if (IF_QFULL(ifq)) {
926 		IF_DROP(ifq);
927 		m_freem(m);
928 	} else {
929 		IF_ENQUEUE(ifq, m);
930 	}
931 	/* we need schednetisr since the address family may change */
932 	schednetisr(isr);
933 	splx(s);
934 
935 	return 1;	/* packet is done, no further processing needed */
936 }
937 
938 /*
939  * The output routine. Takes a packet and encapsulates it in the protocol
940  * given by sc->sc_soparm.sp_proto. See also RFC 1701 and RFC 2004
941  */
942 static int
943 gre_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
944 	   struct rtentry *rt)
945 {
946 	int error = 0;
947 	struct gre_softc *sc = ifp->if_softc;
948 	struct gre_h *gh;
949 	struct ip *ip;
950 	uint8_t ip_tos = 0;
951 	uint16_t etype = 0;
952 
953 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
954 		m_freem(m);
955 		error = ENETDOWN;
956 		goto end;
957 	}
958 
959 #if NBPFILTER > 0
960 	if (ifp->if_bpf != NULL)
961 		bpf_mtap_af(ifp->if_bpf, dst->sa_family, m);
962 #endif
963 
964 	m->m_flags &= ~(M_BCAST|M_MCAST);
965 
966 	GRE_DPRINTF(sc, "dst->sa_family=%d\n", dst->sa_family);
967 	switch (dst->sa_family) {
968 	case AF_INET:
969 		ip = mtod(m, struct ip *);
970 		ip_tos = ip->ip_tos;
971 		etype = htons(ETHERTYPE_IP);
972 		break;
973 #ifdef NETATALK
974 	case AF_APPLETALK:
975 		etype = htons(ETHERTYPE_ATALK);
976 		break;
977 #endif
978 #ifdef INET6
979 	case AF_INET6:
980 		etype = htons(ETHERTYPE_IPV6);
981 		break;
982 #endif
983 	default:
984 		IF_DROP(&ifp->if_snd);
985 		m_freem(m);
986 		error = EAFNOSUPPORT;
987 		goto end;
988 	}
989 
990 	M_PREPEND(m, sizeof(*gh), M_DONTWAIT);
991 
992 	if (m == NULL) {
993 		IF_DROP(&ifp->if_snd);
994 		error = ENOBUFS;
995 		goto end;
996 	}
997 
998 	gh = mtod(m, struct gre_h *);
999 	gh->flags = 0;
1000 	gh->ptype = etype;
1001 	/* XXX Need to handle IP ToS.  Look at how I handle IP TTL. */
1002 
1003 	ifp->if_opackets++;
1004 	ifp->if_obytes += m->m_pkthdr.len;
1005 
1006 	/* send it off */
1007 	if ((error = gre_bufq_enqueue(&sc->sc_snd, m)) != 0) {
1008 		sc->sc_oflow_ev.ev_count++;
1009 		m_freem(m);
1010 	} else
1011 		softint_schedule(sc->sc_si);
1012   end:
1013 	if (error)
1014 		ifp->if_oerrors++;
1015 	return error;
1016 }
1017 
1018 static int
1019 gre_getname(struct socket *so, int req, struct mbuf *nam, struct lwp *l)
1020 {
1021 	return (*so->so_proto->pr_usrreq)(so, req, NULL, nam, NULL, l);
1022 }
1023 
1024 static int
1025 gre_getsockname(struct socket *so, struct mbuf *nam, struct lwp *l)
1026 {
1027 	return gre_getname(so, PRU_SOCKADDR, nam, l);
1028 }
1029 
1030 static int
1031 gre_getpeername(struct socket *so, struct mbuf *nam, struct lwp *l)
1032 {
1033 	return gre_getname(so, PRU_PEERADDR, nam, l);
1034 }
1035 
1036 static int
1037 gre_getnames(struct socket *so, struct lwp *l, struct sockaddr_storage *src,
1038     struct sockaddr_storage *dst)
1039 {
1040 	struct mbuf *m;
1041 	struct sockaddr_storage *ss;
1042 	int rc;
1043 
1044 	if ((m = getsombuf(so, MT_SONAME)) == NULL)
1045 		return ENOBUFS;
1046 
1047 	ss = mtod(m, struct sockaddr_storage *);
1048 
1049 	solock(so);
1050 	if ((rc = gre_getsockname(so, m, l)) != 0)
1051 		goto out;
1052 	*src = *ss;
1053 
1054 	if ((rc = gre_getpeername(so, m, l)) != 0)
1055 		goto out;
1056 	*dst = *ss;
1057 out:
1058 	sounlock(so);
1059 	m_freem(m);
1060 	return rc;
1061 }
1062 
1063 static void
1064 gre_fp_recvloop(void *arg)
1065 {
1066 	struct gre_softc *sc = arg;
1067 
1068 	mutex_enter(&sc->sc_mtx);
1069 	while (gre_fp_recv(sc))
1070 		;
1071 	mutex_exit(&sc->sc_mtx);
1072 	kthread_exit(0);
1073 }
1074 
1075 static bool
1076 gre_fp_recv(struct gre_softc *sc)
1077 {
1078 	int fd, ofd, rc;
1079 	file_t *fp;
1080 
1081 	fp = sc->sc_fp;
1082 	ofd = sc->sc_fd;
1083 	fd = -1;
1084 
1085 	switch (sc->sc_msg) {
1086 	case GRE_M_STOP:
1087 		cv_signal(&sc->sc_fp_condvar);
1088 		return false;
1089 	case GRE_M_SETFP:
1090 		mutex_exit(&sc->sc_mtx);
1091 		rc = fd_dup(fp, 0, &fd, 0);
1092 		mutex_enter(&sc->sc_mtx);
1093 		if (rc != 0) {
1094 			sc->sc_msg = GRE_M_ERR;
1095 			break;
1096 		}
1097 		/*FALLTHROUGH*/
1098 	case GRE_M_DELFP:
1099 		mutex_exit(&sc->sc_mtx);
1100 		if (ofd != -1 && fd_getfile(ofd) != NULL)
1101 			fd_close(ofd);
1102 		mutex_enter(&sc->sc_mtx);
1103 		sc->sc_fd = fd;
1104 		sc->sc_msg = GRE_M_OK;
1105 		break;
1106 	default:
1107 		gre_fp_wait(sc);
1108 		return true;
1109 	}
1110 	cv_signal(&sc->sc_fp_condvar);
1111 	return true;
1112 }
1113 
1114 static bool
1115 gre_fp_send(struct gre_softc *sc, enum gre_msg msg, file_t *fp)
1116 {
1117 	bool rc;
1118 
1119 	mutex_enter(&sc->sc_mtx);
1120 	while (sc->sc_msg != GRE_M_NONE)
1121 		gre_fp_wait(sc);
1122 	sc->sc_fp = fp;
1123 	sc->sc_msg = msg;
1124 	cv_signal(&sc->sc_fp_condvar);
1125 	while (sc->sc_msg != GRE_M_STOP && sc->sc_msg != GRE_M_OK &&
1126 	            sc->sc_msg != GRE_M_ERR)
1127 		gre_fp_wait(sc);
1128 	rc = (sc->sc_msg != GRE_M_ERR);
1129 	sc->sc_msg = GRE_M_NONE;
1130 	cv_signal(&sc->sc_fp_condvar);
1131 	mutex_exit(&sc->sc_mtx);
1132 	return rc;
1133 }
1134 
1135 static int
1136 gre_ssock(struct ifnet *ifp, struct gre_soparm *sp, int fd)
1137 {
1138 	int error = 0;
1139 	const struct protosw *pr;
1140 	file_t *fp;
1141 	struct gre_softc *sc = ifp->if_softc;
1142 	struct socket *so;
1143 	struct sockaddr_storage dst, src;
1144 
1145 	if ((fp = fd_getfile(fd)) == NULL)
1146 		return EBADF;
1147 	if (fp->f_type != DTYPE_SOCKET) {
1148 		fd_putfile(fd);
1149 		return ENOTSOCK;
1150 	}
1151 
1152 	GRE_DPRINTF(sc, "\n");
1153 
1154 	so = (struct socket *)fp->f_data;
1155 	pr = so->so_proto;
1156 
1157 	GRE_DPRINTF(sc, "type %d, proto %d\n", pr->pr_type, pr->pr_protocol);
1158 
1159 	if ((pr->pr_flags & PR_ATOMIC) == 0 ||
1160 	    (sp->sp_type != 0 && pr->pr_type != sp->sp_type) ||
1161 	    (sp->sp_proto != 0 && pr->pr_protocol != 0 &&
1162 	     pr->pr_protocol != sp->sp_proto)) {
1163 		error = EINVAL;
1164 		goto err;
1165 	}
1166 
1167 	GRE_DPRINTF(sc, "\n");
1168 
1169 	/* check address */
1170 	if ((error = gre_getnames(so, curlwp, &src, &dst)) != 0)
1171 		goto err;
1172 
1173 	GRE_DPRINTF(sc, "\n");
1174 
1175 	if (!gre_fp_send(sc, GRE_M_SETFP, fp)) {
1176 		error = EBUSY;
1177 		goto err;
1178 	}
1179 
1180 	GRE_DPRINTF(sc, "\n");
1181 
1182 	sp->sp_src = src;
1183 	sp->sp_dst = dst;
1184 
1185 	sp->sp_so = so;
1186 
1187 err:
1188 	fd_putfile(fd);
1189 	return error;
1190 }
1191 
1192 static bool
1193 sockaddr_is_anyaddr(const struct sockaddr *sa)
1194 {
1195 	socklen_t anylen, salen;
1196 	const void *anyaddr, *addr;
1197 
1198 	if ((anyaddr = sockaddr_anyaddr(sa, &anylen)) == NULL ||
1199 	    (addr = sockaddr_const_addr(sa, &salen)) == NULL)
1200 		return false;
1201 
1202 	if (salen > anylen)
1203 		return false;
1204 
1205 	return memcmp(anyaddr, addr, MIN(anylen, salen)) == 0;
1206 }
1207 
1208 static bool
1209 gre_is_nullconf(const struct gre_soparm *sp)
1210 {
1211 	return sockaddr_is_anyaddr(sstocsa(&sp->sp_src)) ||
1212 	       sockaddr_is_anyaddr(sstocsa(&sp->sp_dst));
1213 }
1214 
1215 static void
1216 gre_clearconf(struct gre_soparm *sp, bool force)
1217 {
1218 	if (sp->sp_bysock || force) {
1219 		sockaddr_copy(sstosa(&sp->sp_src), sizeof(sp->sp_src),
1220 		    sockaddr_any(sstosa(&sp->sp_src)));
1221 		sockaddr_copy(sstosa(&sp->sp_dst), sizeof(sp->sp_dst),
1222 		    sockaddr_any(sstosa(&sp->sp_dst)));
1223 		sp->sp_bysock = false;
1224 	}
1225 	sp->sp_so = NULL; /* XXX */
1226 }
1227 
1228 static int
1229 gre_ioctl_lock(struct gre_softc *sc)
1230 {
1231 	mutex_enter(&sc->sc_mtx);
1232 
1233 	while (sc->sc_state == GRE_S_IOCTL)
1234 		gre_wait(sc);
1235 
1236 	if (sc->sc_state != GRE_S_IDLE) {
1237 		cv_signal(&sc->sc_condvar);
1238 		mutex_exit(&sc->sc_mtx);
1239 		GRE_DPRINTF(sc, "\n");
1240 		return ENXIO;
1241 	}
1242 
1243 	sc->sc_state = GRE_S_IOCTL;
1244 
1245 	mutex_exit(&sc->sc_mtx);
1246 	return 0;
1247 }
1248 
1249 static void
1250 gre_ioctl_unlock(struct gre_softc *sc)
1251 {
1252 	mutex_enter(&sc->sc_mtx);
1253 
1254 	KASSERT(sc->sc_state == GRE_S_IOCTL);
1255 	sc->sc_state = GRE_S_IDLE;
1256 	cv_signal(&sc->sc_condvar);
1257 
1258 	mutex_exit(&sc->sc_mtx);
1259 }
1260 
1261 static int
1262 gre_ioctl(struct ifnet *ifp, const u_long cmd, void *data)
1263 {
1264 	struct ifreq *ifr;
1265 	struct if_laddrreq *lifr = (struct if_laddrreq *)data;
1266 	struct gre_softc *sc = ifp->if_softc;
1267 	struct gre_soparm *sp;
1268 	int fd, error = 0, oproto, otype, s;
1269 	struct gre_soparm sp0;
1270 
1271 	ifr = data;
1272 
1273 	GRE_DPRINTF(sc, "cmd %lu\n", cmd);
1274 
1275 	switch (cmd) {
1276 	case SIOCSIFFLAGS:
1277 	case SIOCSIFMTU:
1278 	case GRESPROTO:
1279 	case GRESADDRD:
1280 	case GRESADDRS:
1281 	case GRESSOCK:
1282 	case GREDSOCK:
1283 	case SIOCSLIFPHYADDR:
1284 	case SIOCDIFPHYADDR:
1285 		if (kauth_authorize_network(curlwp->l_cred,
1286 		    KAUTH_NETWORK_INTERFACE,
1287 		    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
1288 		    NULL) != 0)
1289 			return EPERM;
1290 		break;
1291 	default:
1292 		break;
1293 	}
1294 
1295 	if ((error = gre_ioctl_lock(sc)) != 0) {
1296 		GRE_DPRINTF(sc, "\n");
1297 		return error;
1298 	}
1299 	s = splnet();
1300 
1301 	sp0 = sc->sc_soparm;
1302 	sp0.sp_so = NULL;
1303 	sp = &sp0;
1304 
1305 	GRE_DPRINTF(sc, "\n");
1306 
1307 	switch (cmd) {
1308 	case SIOCINITIFADDR:
1309 		GRE_DPRINTF(sc, "\n");
1310 		if ((ifp->if_flags & IFF_UP) != 0)
1311 			break;
1312 		gre_clearconf(sp, false);
1313 		ifp->if_flags |= IFF_UP;
1314 		goto mksocket;
1315 	case SIOCSIFDSTADDR:
1316 		break;
1317 	case SIOCSIFFLAGS:
1318 		if ((error = ifioctl_common(ifp, cmd, data)) != 0)
1319 			break;
1320 		oproto = sp->sp_proto;
1321 		otype = sp->sp_type;
1322 		switch (ifr->ifr_flags & (IFF_LINK0|IFF_LINK2)) {
1323 		case IFF_LINK0|IFF_LINK2:
1324 			sp->sp_proto = IPPROTO_UDP;
1325 			sp->sp_type = SOCK_DGRAM;
1326 			break;
1327 		case IFF_LINK2:
1328 			sp->sp_proto = 0;
1329 			sp->sp_type = 0;
1330 			break;
1331 		case IFF_LINK0:
1332 			sp->sp_proto = IPPROTO_GRE;
1333 			sp->sp_type = SOCK_RAW;
1334 			break;
1335 		default:
1336 			GRE_DPRINTF(sc, "\n");
1337 			error = EINVAL;
1338 			goto out;
1339 		}
1340 		GRE_DPRINTF(sc, "\n");
1341 		gre_clearconf(sp, false);
1342 		if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) ==
1343 		    (IFF_UP|IFF_RUNNING) &&
1344 		    (oproto == sp->sp_proto || sp->sp_proto == 0) &&
1345 		    (otype == sp->sp_type || sp->sp_type == 0))
1346 			break;
1347 		switch (sp->sp_proto) {
1348 		case IPPROTO_UDP:
1349 		case IPPROTO_GRE:
1350 			goto mksocket;
1351 		default:
1352 			break;
1353 		}
1354 		break;
1355 	case SIOCSIFMTU:
1356 		/* XXX determine MTU automatically by probing w/
1357 		 * XXX do-not-fragment packets?
1358 		 */
1359 		if (ifr->ifr_mtu < 576) {
1360 			error = EINVAL;
1361 			break;
1362 		}
1363 		/*FALLTHROUGH*/
1364 	case SIOCGIFMTU:
1365 		if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET)
1366 			error = 0;
1367 		break;
1368 	case SIOCADDMULTI:
1369 	case SIOCDELMULTI:
1370 		if (ifr == NULL) {
1371 			error = EAFNOSUPPORT;
1372 			break;
1373 		}
1374 		switch (ifreq_getaddr(cmd, ifr)->sa_family) {
1375 #ifdef INET
1376 		case AF_INET:
1377 			break;
1378 #endif
1379 #ifdef INET6
1380 		case AF_INET6:
1381 			break;
1382 #endif
1383 		default:
1384 			error = EAFNOSUPPORT;
1385 			break;
1386 		}
1387 		break;
1388 	case GRESPROTO:
1389 		gre_clearconf(sp, false);
1390 		oproto = sp->sp_proto;
1391 		otype = sp->sp_type;
1392 		sp->sp_proto = ifr->ifr_flags;
1393 		switch (sp->sp_proto) {
1394 		case IPPROTO_UDP:
1395 			ifp->if_flags |= IFF_LINK0|IFF_LINK2;
1396 			sp->sp_type = SOCK_DGRAM;
1397 			break;
1398 		case IPPROTO_GRE:
1399 			ifp->if_flags |= IFF_LINK0;
1400 			ifp->if_flags &= ~IFF_LINK2;
1401 			sp->sp_type = SOCK_RAW;
1402 			break;
1403 		case 0:
1404 			ifp->if_flags &= ~IFF_LINK0;
1405 			ifp->if_flags |= IFF_LINK2;
1406 			sp->sp_type = 0;
1407 			break;
1408 		default:
1409 			error = EPROTONOSUPPORT;
1410 			break;
1411 		}
1412 		if ((oproto == sp->sp_proto || sp->sp_proto == 0) &&
1413 		    (otype == sp->sp_type || sp->sp_type == 0))
1414 			break;
1415 		switch (sp->sp_proto) {
1416 		case IPPROTO_UDP:
1417 		case IPPROTO_GRE:
1418 			goto mksocket;
1419 		default:
1420 			break;
1421 		}
1422 		break;
1423 	case GREGPROTO:
1424 		ifr->ifr_flags = sp->sp_proto;
1425 		break;
1426 	case GRESADDRS:
1427 	case GRESADDRD:
1428 		gre_clearconf(sp, false);
1429 		/* set tunnel endpoints and mark interface as up */
1430 		switch (cmd) {
1431 		case GRESADDRS:
1432 			sockaddr_copy(sstosa(&sp->sp_src),
1433 			    sizeof(sp->sp_src), ifreq_getaddr(cmd, ifr));
1434 			break;
1435 		case GRESADDRD:
1436 			sockaddr_copy(sstosa(&sp->sp_dst),
1437 			    sizeof(sp->sp_dst), ifreq_getaddr(cmd, ifr));
1438 			break;
1439 		}
1440 	checkaddr:
1441 		if (sockaddr_any(sstosa(&sp->sp_src)) == NULL ||
1442 		    sockaddr_any(sstosa(&sp->sp_dst)) == NULL) {
1443 			error = EINVAL;
1444 			break;
1445 		}
1446 		/* let gre_socreate() check the rest */
1447 	mksocket:
1448 		GRE_DPRINTF(sc, "\n");
1449 		/* If we're administratively down, or the configuration
1450 		 * is empty, there's no use creating a socket.
1451 		 */
1452 		if ((ifp->if_flags & IFF_UP) == 0 || gre_is_nullconf(sp))
1453 			goto sendconf;
1454 
1455 		GRE_DPRINTF(sc, "\n");
1456 		fd = 0;
1457 		error = gre_socreate(sc, sp, &fd);
1458 		if (error != 0)
1459 			break;
1460 
1461 	setsock:
1462 		GRE_DPRINTF(sc, "\n");
1463 
1464 		error = gre_ssock(ifp, sp, fd);
1465 
1466 		if (cmd != GRESSOCK) {
1467 			GRE_DPRINTF(sc, "\n");
1468 			/* XXX v. dodgy */
1469 			if (fd_getfile(fd) != NULL)
1470 				fd_close(fd);
1471 		}
1472 
1473 		if (error == 0) {
1474 	sendconf:
1475 			GRE_DPRINTF(sc, "\n");
1476 			ifp->if_flags &= ~IFF_RUNNING;
1477 			gre_reconf(sc, sp);
1478 		}
1479 
1480 		break;
1481 	case GREGADDRS:
1482 		ifreq_setaddr(cmd, ifr, sstosa(&sp->sp_src));
1483 		break;
1484 	case GREGADDRD:
1485 		ifreq_setaddr(cmd, ifr, sstosa(&sp->sp_dst));
1486 		break;
1487 	case GREDSOCK:
1488 		GRE_DPRINTF(sc, "\n");
1489 		if (sp->sp_bysock)
1490 			ifp->if_flags &= ~IFF_UP;
1491 		gre_clearconf(sp, false);
1492 		goto mksocket;
1493 	case GRESSOCK:
1494 		GRE_DPRINTF(sc, "\n");
1495 		gre_clearconf(sp, true);
1496 		fd = (int)ifr->ifr_value;
1497 		sp->sp_bysock = true;
1498 		ifp->if_flags |= IFF_UP;
1499 		goto setsock;
1500 	case SIOCSLIFPHYADDR:
1501 		GRE_DPRINTF(sc, "\n");
1502 		if (lifr->addr.ss_family != lifr->dstaddr.ss_family) {
1503 			error = EAFNOSUPPORT;
1504 			break;
1505 		}
1506 		sockaddr_copy(sstosa(&sp->sp_src), sizeof(sp->sp_src),
1507 		    sstosa(&lifr->addr));
1508 		sockaddr_copy(sstosa(&sp->sp_dst), sizeof(sp->sp_dst),
1509 		    sstosa(&lifr->dstaddr));
1510 		GRE_DPRINTF(sc, "\n");
1511 		goto checkaddr;
1512 	case SIOCDIFPHYADDR:
1513 		GRE_DPRINTF(sc, "\n");
1514 		gre_clearconf(sp, true);
1515 		ifp->if_flags &= ~IFF_UP;
1516 		goto mksocket;
1517 	case SIOCGLIFPHYADDR:
1518 		GRE_DPRINTF(sc, "\n");
1519 		if (gre_is_nullconf(sp)) {
1520 			error = EADDRNOTAVAIL;
1521 			break;
1522 		}
1523 		sockaddr_copy(sstosa(&lifr->addr), sizeof(lifr->addr),
1524 		    sstosa(&sp->sp_src));
1525 		sockaddr_copy(sstosa(&lifr->dstaddr), sizeof(lifr->dstaddr),
1526 		    sstosa(&sp->sp_dst));
1527 		GRE_DPRINTF(sc, "\n");
1528 		break;
1529 	default:
1530 		error = ifioctl_common(ifp, cmd, data);
1531 		break;
1532 	}
1533 out:
1534 	GRE_DPRINTF(sc, "\n");
1535 	splx(s);
1536 	gre_ioctl_unlock(sc);
1537 	return error;
1538 }
1539 
1540 #endif
1541 
1542 void	greattach(int);
1543 
1544 /* ARGSUSED */
1545 void
1546 greattach(int count)
1547 {
1548 #ifdef INET
1549 	if_clone_attach(&gre_cloner);
1550 #endif
1551 }
1552