xref: /netbsd-src/sys/net/if_gre.c (revision 3816d47b2c42fcd6e549e3407f842a5b1a1d23ad)
1 /*	$NetBSD: if_gre.c,v 1.141 2009/09/02 14:56:57 tls 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 1.141 2009/09/02 14:56:57 tls Exp $");
49 
50 #include "opt_atalk.h"
51 #include "opt_gre.h"
52 #include "opt_inet.h"
53 #include "bpfilter.h"
54 
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 #include <sys/systm.h>
70 #include <sys/sysctl.h>
71 #include <sys/kauth.h>
72 
73 #include <sys/kernel.h>
74 #include <sys/mutex.h>
75 #include <sys/condvar.h>
76 #include <sys/kthread.h>
77 
78 #include <sys/cpu.h>
79 
80 #include <net/ethertypes.h>
81 #include <net/if.h>
82 #include <net/if_types.h>
83 #include <net/netisr.h>
84 #include <net/route.h>
85 
86 #include <netinet/in_systm.h>
87 #include <netinet/in.h>
88 #include <netinet/ip.h> /* we always need this for sizeof(struct ip) */
89 
90 #ifdef INET
91 #include <netinet/in_var.h>
92 #include <netinet/ip_var.h>
93 #endif
94 
95 #ifdef INET6
96 #include <netinet6/in6_var.h>
97 #endif
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 	const struct sockaddr *any;
321 
322 	if ((any = sockaddr_any_by_family(AF_INET)) == NULL &&
323 	    (any = sockaddr_any_by_family(AF_INET6)) == NULL)
324 		return -1;
325 
326 	sc = malloc(sizeof(struct gre_softc), M_DEVBUF, M_WAITOK|M_ZERO);
327 	mutex_init(&sc->sc_mtx, MUTEX_DRIVER, IPL_SOFTNET);
328 	cv_init(&sc->sc_condvar, "gre wait");
329 	cv_init(&sc->sc_fp_condvar, "gre fp");
330 
331 	if_initname(&sc->sc_if, ifc->ifc_name, unit);
332 	sc->sc_if.if_softc = sc;
333 	sc->sc_if.if_type = IFT_TUNNEL;
334 	sc->sc_if.if_addrlen = 0;
335 	sc->sc_if.if_hdrlen = sizeof(struct ip) + sizeof(struct gre_h);
336 	sc->sc_if.if_dlt = DLT_NULL;
337 	sc->sc_if.if_mtu = GREMTU;
338 	sc->sc_if.if_flags = IFF_POINTOPOINT|IFF_MULTICAST;
339 	sc->sc_if.if_output = gre_output;
340 	sc->sc_if.if_ioctl = gre_ioctl;
341 	sp = &sc->sc_soparm;
342 	sockaddr_copy(sstosa(&sp->sp_dst), sizeof(sp->sp_dst), any);
343 	sockaddr_copy(sstosa(&sp->sp_src), sizeof(sp->sp_src), any);
344 	sp->sp_proto = IPPROTO_GRE;
345 	sp->sp_type = SOCK_RAW;
346 
347 	sc->sc_fd = -1;
348 
349 	rc = kthread_create(PRI_NONE, KTHREAD_MPSAFE, NULL, gre_fp_recvloop, sc,
350 	    NULL, sc->sc_if.if_xname);
351 
352 	if (rc != 0)
353 		return -1;
354 
355 	gre_evcnt_attach(sc);
356 
357 	gre_bufq_init(&sc->sc_snd, 17);
358 	sc->sc_if.if_flags |= IFF_LINK0;
359 	if_attach(&sc->sc_if);
360 	if_alloc_sadl(&sc->sc_if);
361 #if NBPFILTER > 0
362 	bpfattach(&sc->sc_if, DLT_NULL, sizeof(uint32_t));
363 #endif
364 	sc->sc_state = GRE_S_IDLE;
365 	return 0;
366 }
367 
368 static int
369 gre_clone_destroy(struct ifnet *ifp)
370 {
371 	int s;
372 	struct gre_softc *sc = ifp->if_softc;
373 
374 	GRE_DPRINTF(sc, "\n");
375 
376 #if NBPFILTER > 0
377 	bpfdetach(ifp);
378 #endif
379 	s = splnet();
380 	if_detach(ifp);
381 
382 	/* Some LWPs may still wait in gre_ioctl_lock(), however,
383 	 * no new LWP will enter gre_ioctl_lock(), because ifunit()
384 	 * cannot locate the interface any longer.
385 	 */
386 	mutex_enter(&sc->sc_mtx);
387 	GRE_DPRINTF(sc, "\n");
388 	while (sc->sc_state != GRE_S_IDLE)
389 		gre_wait(sc);
390 	GRE_DPRINTF(sc, "\n");
391 	sc->sc_state = GRE_S_DIE;
392 	cv_broadcast(&sc->sc_condvar);
393 	while (sc->sc_waiters > 0)
394 		cv_wait(&sc->sc_condvar, &sc->sc_mtx);
395 	/* At this point, no other LWP will access the gre_softc, so
396 	 * we can release the mutex.
397 	 */
398 	mutex_exit(&sc->sc_mtx);
399 	GRE_DPRINTF(sc, "\n");
400 	/* Note that we must not hold the mutex while we call gre_reconf(). */
401 	gre_reconf(sc, NULL);
402 
403 	mutex_enter(&sc->sc_mtx);
404 	sc->sc_msg = GRE_M_STOP;
405 	cv_signal(&sc->sc_fp_condvar);
406 	while (sc->sc_fp_waiters > 0)
407 		cv_wait(&sc->sc_fp_condvar, &sc->sc_mtx);
408 	mutex_exit(&sc->sc_mtx);
409 
410 	splx(s);
411 
412 	cv_destroy(&sc->sc_condvar);
413 	cv_destroy(&sc->sc_fp_condvar);
414 	mutex_destroy(&sc->sc_mtx);
415 	gre_evcnt_detach(sc);
416 	free(sc, M_DEVBUF);
417 
418 	return 0;
419 }
420 
421 static void
422 gre_receive(struct socket *so, void *arg, int events, int waitflag)
423 {
424 	struct gre_softc *sc = (struct gre_softc *)arg;
425 	int rc;
426 	const struct gre_h *gh;
427 	struct mbuf *m;
428 
429 	GRE_DPRINTF(sc, "enter\n");
430 
431 	sc->sc_recv_ev.ev_count++;
432 
433 	rc = gre_soreceive(so, &m);
434 	/* TBD Back off if ECONNREFUSED (indicates
435 	 * ICMP Port Unreachable)?
436 	 */
437 	if (rc == EWOULDBLOCK) {
438 		GRE_DPRINTF(sc, "EWOULDBLOCK\n");
439 		sc->sc_block_ev.ev_count++;
440 		return;
441 	} else if (rc != 0 || m == NULL) {
442 		GRE_DPRINTF(sc, "%s: rc %d m %p\n",
443 		    sc->sc_if.if_xname, rc, (void *)m);
444 		sc->sc_error_ev.ev_count++;
445 		return;
446 	}
447 	if (m->m_len < sizeof(*gh) && (m = m_pullup(m, sizeof(*gh))) == NULL) {
448 		GRE_DPRINTF(sc, "m_pullup failed\n");
449 		sc->sc_pullup_ev.ev_count++;
450 		return;
451 	}
452 	gh = mtod(m, const struct gre_h *);
453 
454 	if (gre_input(sc, m, 0, gh) == 0) {
455 		sc->sc_unsupp_ev.ev_count++;
456 		GRE_DPRINTF(sc, "dropping unsupported\n");
457 		m_freem(m);
458 	}
459 }
460 
461 static void
462 gre_upcall_add(struct socket *so, void *arg)
463 {
464 	/* XXX What if the kernel already set an upcall? */
465 	KASSERT((so->so_rcv.sb_flags & SB_UPCALL) == 0);
466 	so->so_upcallarg = arg;
467 	so->so_upcall = gre_receive;
468 	so->so_rcv.sb_flags |= SB_UPCALL;
469 }
470 
471 static void
472 gre_upcall_remove(struct socket *so)
473 {
474 	so->so_rcv.sb_flags &= ~SB_UPCALL;
475 	so->so_upcallarg = NULL;
476 	so->so_upcall = NULL;
477 }
478 
479 static int
480 gre_socreate(struct gre_softc *sc, const struct gre_soparm *sp, int *fdout)
481 {
482 	const struct protosw *pr;
483 	int fd, rc;
484 	struct mbuf *m;
485 	struct sockaddr *sa;
486 	struct socket *so;
487 	sa_family_t af;
488 	int val;
489 
490 	GRE_DPRINTF(sc, "enter\n");
491 
492 	af = sp->sp_src.ss_family;
493 	rc = fsocreate(af, NULL, sp->sp_type, sp->sp_proto, curlwp, &fd);
494 	if (rc != 0) {
495 		GRE_DPRINTF(sc, "fsocreate failed\n");
496 		return rc;
497 	}
498 
499 	if ((rc = fd_getsock(fd, &so)) != 0)
500 		return rc;
501 
502 	if ((m = getsombuf(so, MT_SONAME)) == NULL) {
503 		rc = ENOBUFS;
504 		goto out;
505 	}
506 	sa = mtod(m, struct sockaddr *);
507 	sockaddr_copy(sa, MIN(MLEN, sizeof(sp->sp_src)), sstocsa(&sp->sp_src));
508 	m->m_len = sp->sp_src.ss_len;
509 
510 	if ((rc = sobind(so, m, curlwp)) != 0) {
511 		GRE_DPRINTF(sc, "sobind failed\n");
512 		goto out;
513 	}
514 
515 	sockaddr_copy(sa, MIN(MLEN, sizeof(sp->sp_dst)), sstocsa(&sp->sp_dst));
516 	m->m_len = sp->sp_dst.ss_len;
517 
518 	solock(so);
519 	if ((rc = soconnect(so, m, curlwp)) != 0) {
520 		GRE_DPRINTF(sc, "soconnect failed\n");
521 		sounlock(so);
522 		goto out;
523 	}
524 	sounlock(so);
525 
526 	m = NULL;
527 
528 	/* XXX convert to a (new) SOL_SOCKET call */
529   	pr = so->so_proto;
530   	KASSERT(pr != NULL);
531  	rc = so_setsockopt(curlwp, so, IPPROTO_IP, IP_TTL,
532 	    &ip_gre_ttl, sizeof(ip_gre_ttl));
533   	if (rc != 0) {
534  		GRE_DPRINTF(sc, "so_setsockopt ttl failed\n");
535   		rc = 0;
536   	}
537 
538  	val = 1;
539  	rc = so_setsockopt(curlwp, so, SOL_SOCKET, SO_NOHEADER,
540 	    &val, sizeof(val));
541   	if (rc != 0) {
542  		GRE_DPRINTF(sc, "so_setsockopt SO_NOHEADER failed\n");
543 		rc = 0;
544 	}
545 out:
546 	m_freem(m);
547 
548 	if (rc != 0)
549 		fd_close(fd);
550 	else  {
551 		fd_putfile(fd);
552 		*fdout = fd;
553 	}
554 
555 	return rc;
556 }
557 
558 static int
559 gre_sosend(struct socket *so, struct mbuf *top)
560 {
561 	struct mbuf	**mp;
562 	struct proc	*p;
563 	long		space, resid;
564 	int		error;
565 	struct lwp * const l = curlwp;
566 
567 	p = l->l_proc;
568 
569 	resid = top->m_pkthdr.len;
570 	if (p)
571 		l->l_ru.ru_msgsnd++;
572 #define	snderr(errno)	{ error = errno; goto release; }
573 
574 	solock(so);
575 	if ((error = sblock(&so->so_snd, M_NOWAIT)) != 0)
576 		goto out;
577 	if (so->so_state & SS_CANTSENDMORE)
578 		snderr(EPIPE);
579 	if (so->so_error) {
580 		error = so->so_error;
581 		so->so_error = 0;
582 		goto release;
583 	}
584 	if ((so->so_state & SS_ISCONNECTED) == 0) {
585 		if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
586 			if ((so->so_state & SS_ISCONFIRMING) == 0)
587 				snderr(ENOTCONN);
588 		} else
589 			snderr(EDESTADDRREQ);
590 	}
591 	space = sbspace(&so->so_snd);
592 	if (resid > so->so_snd.sb_hiwat)
593 		snderr(EMSGSIZE);
594 	if (space < resid)
595 		snderr(EWOULDBLOCK);
596 	mp = &top;
597 	/*
598 	 * Data is prepackaged in "top".
599 	 */
600 	if (so->so_state & SS_CANTSENDMORE)
601 		snderr(EPIPE);
602 	error = (*so->so_proto->pr_usrreq)(so, PRU_SEND, top, NULL, NULL, l);
603 	top = NULL;
604 	mp = &top;
605  release:
606 	sbunlock(&so->so_snd);
607  out:
608  	sounlock(so);
609 	if (top != NULL)
610 		m_freem(top);
611 	return error;
612 }
613 
614 /* This is a stripped-down version of soreceive() that will never
615  * block.  It will support SOCK_DGRAM sockets.  It may also support
616  * SOCK_SEQPACKET sockets.
617  */
618 static int
619 gre_soreceive(struct socket *so, struct mbuf **mp0)
620 {
621 	struct mbuf *m, **mp;
622 	int flags, len, error, type;
623 	const struct protosw	*pr;
624 	struct mbuf *nextrecord;
625 
626 	KASSERT(mp0 != NULL);
627 
628 	flags = MSG_DONTWAIT;
629 	pr = so->so_proto;
630 	mp = mp0;
631 	type = 0;
632 
633 	*mp = NULL;
634 
635 	KASSERT(pr->pr_flags & PR_ATOMIC);
636 
637 	if (so->so_state & SS_ISCONFIRMING)
638 		(*pr->pr_usrreq)(so, PRU_RCVD, NULL, NULL, NULL, curlwp);
639  restart:
640 	if ((error = sblock(&so->so_rcv, M_NOWAIT)) != 0) {
641 		return error;
642 	}
643 	m = so->so_rcv.sb_mb;
644 	/*
645 	 * If we have less data than requested, do not block awaiting more.
646 	 */
647 	if (m == NULL) {
648 #ifdef DIAGNOSTIC
649 		if (so->so_rcv.sb_cc)
650 			panic("receive 1");
651 #endif
652 		if (so->so_error) {
653 			error = so->so_error;
654 			so->so_error = 0;
655 		} else if (so->so_state & SS_CANTRCVMORE)
656 			;
657 		else if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0
658 		      && (so->so_proto->pr_flags & PR_CONNREQUIRED))
659 			error = ENOTCONN;
660 		else
661 			error = EWOULDBLOCK;
662 		goto release;
663 	}
664 	/*
665 	 * On entry here, m points to the first record of the socket buffer.
666 	 * While we process the initial mbufs containing address and control
667 	 * info, we save a copy of m->m_nextpkt into nextrecord.
668 	 */
669 	if (curlwp != NULL)
670 		curlwp->l_ru.ru_msgrcv++;
671 	KASSERT(m == so->so_rcv.sb_mb);
672 	SBLASTRECORDCHK(&so->so_rcv, "soreceive 1");
673 	SBLASTMBUFCHK(&so->so_rcv, "soreceive 1");
674 	nextrecord = m->m_nextpkt;
675 	if (pr->pr_flags & PR_ADDR) {
676 #ifdef DIAGNOSTIC
677 		if (m->m_type != MT_SONAME)
678 			panic("receive 1a");
679 #endif
680 		sbfree(&so->so_rcv, m);
681 		MFREE(m, so->so_rcv.sb_mb);
682 		m = so->so_rcv.sb_mb;
683 	}
684 	while (m != NULL && m->m_type == MT_CONTROL && error == 0) {
685 		sbfree(&so->so_rcv, m);
686 		/*
687 		 * Dispose of any SCM_RIGHTS message that went
688 		 * through the read path rather than recv.
689 		 */
690 		if (pr->pr_domain->dom_dispose &&
691 		    mtod(m, struct cmsghdr *)->cmsg_type == SCM_RIGHTS)
692 			(*pr->pr_domain->dom_dispose)(m);
693 		MFREE(m, so->so_rcv.sb_mb);
694 		m = so->so_rcv.sb_mb;
695 	}
696 
697 	/*
698 	 * If m is non-NULL, we have some data to read.  From now on,
699 	 * make sure to keep sb_lastrecord consistent when working on
700 	 * the last packet on the chain (nextrecord == NULL) and we
701 	 * change m->m_nextpkt.
702 	 */
703 	if (m != NULL) {
704 		m->m_nextpkt = nextrecord;
705 		/*
706 		 * If nextrecord == NULL (this is a single chain),
707 		 * then sb_lastrecord may not be valid here if m
708 		 * was changed earlier.
709 		 */
710 		if (nextrecord == NULL) {
711 			KASSERT(so->so_rcv.sb_mb == m);
712 			so->so_rcv.sb_lastrecord = m;
713 		}
714 		type = m->m_type;
715 		if (type == MT_OOBDATA)
716 			flags |= MSG_OOB;
717 	} else {
718 		KASSERT(so->so_rcv.sb_mb == m);
719 		so->so_rcv.sb_mb = nextrecord;
720 		SB_EMPTY_FIXUP(&so->so_rcv);
721 	}
722 	SBLASTRECORDCHK(&so->so_rcv, "soreceive 2");
723 	SBLASTMBUFCHK(&so->so_rcv, "soreceive 2");
724 
725 	while (m != NULL) {
726 		if (m->m_type == MT_OOBDATA) {
727 			if (type != MT_OOBDATA)
728 				break;
729 		} else if (type == MT_OOBDATA)
730 			break;
731 #ifdef DIAGNOSTIC
732 		else if (m->m_type != MT_DATA && m->m_type != MT_HEADER)
733 			panic("receive 3");
734 #endif
735 		so->so_state &= ~SS_RCVATMARK;
736 		if (so->so_oobmark != 0 && so->so_oobmark < m->m_len)
737 			break;
738 		len = m->m_len;
739 		/*
740 		 * mp is set, just pass back the mbufs.
741 		 * Sockbuf must be consistent here (points to current mbuf,
742 		 * it points to next record) when we drop priority;
743 		 * we must note any additions to the sockbuf when we
744 		 * block interrupts again.
745 		 */
746 		if (m->m_flags & M_EOR)
747 			flags |= MSG_EOR;
748 		nextrecord = m->m_nextpkt;
749 		sbfree(&so->so_rcv, m);
750 		*mp = m;
751 		mp = &m->m_next;
752 		so->so_rcv.sb_mb = m = m->m_next;
753 		*mp = NULL;
754 		/*
755 		 * If m != NULL, we also know that
756 		 * so->so_rcv.sb_mb != NULL.
757 		 */
758 		KASSERT(so->so_rcv.sb_mb == m);
759 		if (m) {
760 			m->m_nextpkt = nextrecord;
761 			if (nextrecord == NULL)
762 				so->so_rcv.sb_lastrecord = m;
763 		} else {
764 			so->so_rcv.sb_mb = nextrecord;
765 			SB_EMPTY_FIXUP(&so->so_rcv);
766 		}
767 		SBLASTRECORDCHK(&so->so_rcv, "soreceive 3");
768 		SBLASTMBUFCHK(&so->so_rcv, "soreceive 3");
769 		if (so->so_oobmark) {
770 			so->so_oobmark -= len;
771 			if (so->so_oobmark == 0) {
772 				so->so_state |= SS_RCVATMARK;
773 				break;
774 			}
775 		}
776 		if (flags & MSG_EOR)
777 			break;
778 	}
779 
780 	if (m != NULL) {
781 		m_freem(*mp);
782 		*mp = NULL;
783 		error = ENOMEM;
784 		(void) sbdroprecord(&so->so_rcv);
785 	} else {
786 		/*
787 		 * First part is an inline SB_EMPTY_FIXUP().  Second
788 		 * part makes sure sb_lastrecord is up-to-date if
789 		 * there is still data in the socket buffer.
790 		 */
791 		so->so_rcv.sb_mb = nextrecord;
792 		if (so->so_rcv.sb_mb == NULL) {
793 			so->so_rcv.sb_mbtail = NULL;
794 			so->so_rcv.sb_lastrecord = NULL;
795 		} else if (nextrecord->m_nextpkt == NULL)
796 			so->so_rcv.sb_lastrecord = nextrecord;
797 	}
798 	SBLASTRECORDCHK(&so->so_rcv, "soreceive 4");
799 	SBLASTMBUFCHK(&so->so_rcv, "soreceive 4");
800 	if (pr->pr_flags & PR_WANTRCVD && so->so_pcb)
801 		(*pr->pr_usrreq)(so, PRU_RCVD, NULL,
802 		    (struct mbuf *)(long)flags, NULL, curlwp);
803 	if (*mp0 == NULL && (flags & MSG_EOR) == 0 &&
804 	    (so->so_state & SS_CANTRCVMORE) == 0) {
805 		sbunlock(&so->so_rcv);
806 		goto restart;
807 	}
808 
809  release:
810 	sbunlock(&so->so_rcv);
811 	return error;
812 }
813 
814 static struct socket *
815 gre_reconf(struct gre_softc *sc, const struct gre_soparm *newsoparm)
816 {
817 	struct ifnet *ifp = &sc->sc_if;
818 
819 	GRE_DPRINTF(sc, "enter\n");
820 
821 shutdown:
822 	if (sc->sc_soparm.sp_so != NULL) {
823 		GRE_DPRINTF(sc, "\n");
824 		gre_upcall_remove(sc->sc_soparm.sp_so);
825 		softint_disestablish(sc->sc_si);
826 		sc->sc_si = NULL;
827 		gre_fp_send(sc, GRE_M_DELFP, NULL);
828 		gre_clearconf(&sc->sc_soparm, false);
829 	}
830 
831 	if (newsoparm != NULL) {
832 		GRE_DPRINTF(sc, "\n");
833 		sc->sc_soparm = *newsoparm;
834 		newsoparm = NULL;
835 	}
836 
837 	if (sc->sc_soparm.sp_so != NULL) {
838 		GRE_DPRINTF(sc, "\n");
839 		sc->sc_si = softint_establish(SOFTINT_NET, greintr, sc);
840 		gre_upcall_add(sc->sc_soparm.sp_so, sc);
841 		if ((ifp->if_flags & IFF_UP) == 0) {
842 			GRE_DPRINTF(sc, "down\n");
843 			goto shutdown;
844 		}
845 	}
846 
847 	GRE_DPRINTF(sc, "\n");
848 	if (sc->sc_soparm.sp_so != NULL)
849 		sc->sc_if.if_flags |= IFF_RUNNING;
850 	else {
851 		gre_bufq_purge(&sc->sc_snd);
852 		sc->sc_if.if_flags &= ~IFF_RUNNING;
853 	}
854 	return sc->sc_soparm.sp_so;
855 }
856 
857 static int
858 gre_input(struct gre_softc *sc, struct mbuf *m, int hlen,
859     const struct gre_h *gh)
860 {
861 	uint16_t flags;
862 	uint32_t af;		/* af passed to BPF tap */
863 	int isr, s;
864 	struct ifqueue *ifq;
865 
866 	sc->sc_if.if_ipackets++;
867 	sc->sc_if.if_ibytes += m->m_pkthdr.len;
868 
869 	hlen += sizeof(struct gre_h);
870 
871 	/* process GRE flags as packet can be of variable len */
872 	flags = ntohs(gh->flags);
873 
874 	/* Checksum & Offset are present */
875 	if ((flags & GRE_CP) | (flags & GRE_RP))
876 		hlen += 4;
877 	/* We don't support routing fields (variable length) */
878 	if (flags & GRE_RP) {
879 		sc->sc_if.if_ierrors++;
880 		return 0;
881 	}
882 	if (flags & GRE_KP)
883 		hlen += 4;
884 	if (flags & GRE_SP)
885 		hlen += 4;
886 
887 	switch (ntohs(gh->ptype)) { /* ethertypes */
888 #ifdef INET
889 	case ETHERTYPE_IP:
890 		ifq = &ipintrq;
891 		isr = NETISR_IP;
892 		af = AF_INET;
893 		break;
894 #endif
895 #ifdef NETATALK
896 	case ETHERTYPE_ATALK:
897 		ifq = &atintrq1;
898 		isr = NETISR_ATALK;
899 		af = AF_APPLETALK;
900 		break;
901 #endif
902 #ifdef INET6
903 	case ETHERTYPE_IPV6:
904 		ifq = &ip6intrq;
905 		isr = NETISR_IPV6;
906 		af = AF_INET6;
907 		break;
908 #endif
909 	default:	   /* others not yet supported */
910 		GRE_DPRINTF(sc, "unhandled ethertype 0x%04x\n",
911 		    ntohs(gh->ptype));
912 		sc->sc_if.if_noproto++;
913 		return 0;
914 	}
915 
916 	if (hlen > m->m_pkthdr.len) {
917 		m_freem(m);
918 		sc->sc_if.if_ierrors++;
919 		return EINVAL;
920 	}
921 	m_adj(m, hlen);
922 
923 #if NBPFILTER > 0
924 	if (sc->sc_if.if_bpf != NULL)
925 		bpf_mtap_af(sc->sc_if.if_bpf, af, m);
926 #endif /*NBPFILTER > 0*/
927 
928 	m->m_pkthdr.rcvif = &sc->sc_if;
929 
930 	s = splnet();
931 	if (IF_QFULL(ifq)) {
932 		IF_DROP(ifq);
933 		m_freem(m);
934 	} else {
935 		IF_ENQUEUE(ifq, m);
936 	}
937 	/* we need schednetisr since the address family may change */
938 	schednetisr(isr);
939 	splx(s);
940 
941 	return 1;	/* packet is done, no further processing needed */
942 }
943 
944 /*
945  * The output routine. Takes a packet and encapsulates it in the protocol
946  * given by sc->sc_soparm.sp_proto. See also RFC 1701 and RFC 2004
947  */
948 static int
949 gre_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
950 	   struct rtentry *rt)
951 {
952 	int error = 0;
953 	struct gre_softc *sc = ifp->if_softc;
954 	struct gre_h *gh;
955 	uint16_t etype = 0;
956 
957 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING)) {
958 		m_freem(m);
959 		error = ENETDOWN;
960 		goto end;
961 	}
962 
963 #if NBPFILTER > 0
964 	if (ifp->if_bpf != NULL)
965 		bpf_mtap_af(ifp->if_bpf, dst->sa_family, m);
966 #endif
967 
968 	m->m_flags &= ~(M_BCAST|M_MCAST);
969 
970 	GRE_DPRINTF(sc, "dst->sa_family=%d\n", dst->sa_family);
971 	switch (dst->sa_family) {
972 #ifdef INET
973 	case AF_INET:
974 		/* TBD Extract the IP ToS field and set the
975 		 * encapsulating protocol's ToS to suit.
976 		 */
977 		etype = htons(ETHERTYPE_IP);
978 		break;
979 #endif
980 #ifdef NETATALK
981 	case AF_APPLETALK:
982 		etype = htons(ETHERTYPE_ATALK);
983 		break;
984 #endif
985 #ifdef INET6
986 	case AF_INET6:
987 		etype = htons(ETHERTYPE_IPV6);
988 		break;
989 #endif
990 	default:
991 		IF_DROP(&ifp->if_snd);
992 		m_freem(m);
993 		error = EAFNOSUPPORT;
994 		goto end;
995 	}
996 
997 	M_PREPEND(m, sizeof(*gh), M_DONTWAIT);
998 
999 	if (m == NULL) {
1000 		IF_DROP(&ifp->if_snd);
1001 		error = ENOBUFS;
1002 		goto end;
1003 	}
1004 
1005 	gh = mtod(m, struct gre_h *);
1006 	gh->flags = 0;
1007 	gh->ptype = etype;
1008 	/* XXX Need to handle IP ToS.  Look at how I handle IP TTL. */
1009 
1010 	ifp->if_opackets++;
1011 	ifp->if_obytes += m->m_pkthdr.len;
1012 
1013 	/* send it off */
1014 	if ((error = gre_bufq_enqueue(&sc->sc_snd, m)) != 0) {
1015 		sc->sc_oflow_ev.ev_count++;
1016 		m_freem(m);
1017 	} else
1018 		softint_schedule(sc->sc_si);
1019   end:
1020 	if (error)
1021 		ifp->if_oerrors++;
1022 	return error;
1023 }
1024 
1025 static int
1026 gre_getname(struct socket *so, int req, struct mbuf *nam, struct lwp *l)
1027 {
1028 	return (*so->so_proto->pr_usrreq)(so, req, NULL, nam, NULL, l);
1029 }
1030 
1031 static int
1032 gre_getsockname(struct socket *so, struct mbuf *nam, struct lwp *l)
1033 {
1034 	return gre_getname(so, PRU_SOCKADDR, nam, l);
1035 }
1036 
1037 static int
1038 gre_getpeername(struct socket *so, struct mbuf *nam, struct lwp *l)
1039 {
1040 	return gre_getname(so, PRU_PEERADDR, nam, l);
1041 }
1042 
1043 static int
1044 gre_getnames(struct socket *so, struct lwp *l, struct sockaddr_storage *src,
1045     struct sockaddr_storage *dst)
1046 {
1047 	struct mbuf *m;
1048 	struct sockaddr_storage *ss;
1049 	int rc;
1050 
1051 	if ((m = getsombuf(so, MT_SONAME)) == NULL)
1052 		return ENOBUFS;
1053 
1054 	ss = mtod(m, struct sockaddr_storage *);
1055 
1056 	solock(so);
1057 	if ((rc = gre_getsockname(so, m, l)) != 0)
1058 		goto out;
1059 	*src = *ss;
1060 
1061 	if ((rc = gre_getpeername(so, m, l)) != 0)
1062 		goto out;
1063 	*dst = *ss;
1064 out:
1065 	sounlock(so);
1066 	m_freem(m);
1067 	return rc;
1068 }
1069 
1070 static void
1071 gre_fp_recvloop(void *arg)
1072 {
1073 	struct gre_softc *sc = arg;
1074 
1075 	mutex_enter(&sc->sc_mtx);
1076 	while (gre_fp_recv(sc))
1077 		;
1078 	mutex_exit(&sc->sc_mtx);
1079 	kthread_exit(0);
1080 }
1081 
1082 static bool
1083 gre_fp_recv(struct gre_softc *sc)
1084 {
1085 	int fd, ofd, rc;
1086 	file_t *fp;
1087 
1088 	fp = sc->sc_fp;
1089 	ofd = sc->sc_fd;
1090 	fd = -1;
1091 
1092 	switch (sc->sc_msg) {
1093 	case GRE_M_STOP:
1094 		cv_signal(&sc->sc_fp_condvar);
1095 		return false;
1096 	case GRE_M_SETFP:
1097 		mutex_exit(&sc->sc_mtx);
1098 		rc = fd_dup(fp, 0, &fd, 0);
1099 		mutex_enter(&sc->sc_mtx);
1100 		if (rc != 0) {
1101 			sc->sc_msg = GRE_M_ERR;
1102 			break;
1103 		}
1104 		/*FALLTHROUGH*/
1105 	case GRE_M_DELFP:
1106 		mutex_exit(&sc->sc_mtx);
1107 		if (ofd != -1 && fd_getfile(ofd) != NULL)
1108 			fd_close(ofd);
1109 		mutex_enter(&sc->sc_mtx);
1110 		sc->sc_fd = fd;
1111 		sc->sc_msg = GRE_M_OK;
1112 		break;
1113 	default:
1114 		gre_fp_wait(sc);
1115 		return true;
1116 	}
1117 	cv_signal(&sc->sc_fp_condvar);
1118 	return true;
1119 }
1120 
1121 static bool
1122 gre_fp_send(struct gre_softc *sc, enum gre_msg msg, file_t *fp)
1123 {
1124 	bool rc;
1125 
1126 	mutex_enter(&sc->sc_mtx);
1127 	while (sc->sc_msg != GRE_M_NONE)
1128 		gre_fp_wait(sc);
1129 	sc->sc_fp = fp;
1130 	sc->sc_msg = msg;
1131 	cv_signal(&sc->sc_fp_condvar);
1132 	while (sc->sc_msg != GRE_M_STOP && sc->sc_msg != GRE_M_OK &&
1133 	            sc->sc_msg != GRE_M_ERR)
1134 		gre_fp_wait(sc);
1135 	rc = (sc->sc_msg != GRE_M_ERR);
1136 	sc->sc_msg = GRE_M_NONE;
1137 	cv_signal(&sc->sc_fp_condvar);
1138 	mutex_exit(&sc->sc_mtx);
1139 	return rc;
1140 }
1141 
1142 static int
1143 gre_ssock(struct ifnet *ifp, struct gre_soparm *sp, int fd)
1144 {
1145 	int error = 0;
1146 	const struct protosw *pr;
1147 	file_t *fp;
1148 	struct gre_softc *sc = ifp->if_softc;
1149 	struct socket *so;
1150 	struct sockaddr_storage dst, src;
1151 
1152 	if ((fp = fd_getfile(fd)) == NULL)
1153 		return EBADF;
1154 	if (fp->f_type != DTYPE_SOCKET) {
1155 		fd_putfile(fd);
1156 		return ENOTSOCK;
1157 	}
1158 
1159 	GRE_DPRINTF(sc, "\n");
1160 
1161 	so = (struct socket *)fp->f_data;
1162 	pr = so->so_proto;
1163 
1164 	GRE_DPRINTF(sc, "type %d, proto %d\n", pr->pr_type, pr->pr_protocol);
1165 
1166 	if ((pr->pr_flags & PR_ATOMIC) == 0 ||
1167 	    (sp->sp_type != 0 && pr->pr_type != sp->sp_type) ||
1168 	    (sp->sp_proto != 0 && pr->pr_protocol != 0 &&
1169 	     pr->pr_protocol != sp->sp_proto)) {
1170 		error = EINVAL;
1171 		goto err;
1172 	}
1173 
1174 	GRE_DPRINTF(sc, "\n");
1175 
1176 	/* check address */
1177 	if ((error = gre_getnames(so, curlwp, &src, &dst)) != 0)
1178 		goto err;
1179 
1180 	GRE_DPRINTF(sc, "\n");
1181 
1182 	if (!gre_fp_send(sc, GRE_M_SETFP, fp)) {
1183 		error = EBUSY;
1184 		goto err;
1185 	}
1186 
1187 	GRE_DPRINTF(sc, "\n");
1188 
1189 	sp->sp_src = src;
1190 	sp->sp_dst = dst;
1191 
1192 	sp->sp_so = so;
1193 
1194 err:
1195 	fd_putfile(fd);
1196 	return error;
1197 }
1198 
1199 static bool
1200 sockaddr_is_anyaddr(const struct sockaddr *sa)
1201 {
1202 	socklen_t anylen, salen;
1203 	const void *anyaddr, *addr;
1204 
1205 	if ((anyaddr = sockaddr_anyaddr(sa, &anylen)) == NULL ||
1206 	    (addr = sockaddr_const_addr(sa, &salen)) == NULL)
1207 		return false;
1208 
1209 	if (salen > anylen)
1210 		return false;
1211 
1212 	return memcmp(anyaddr, addr, MIN(anylen, salen)) == 0;
1213 }
1214 
1215 static bool
1216 gre_is_nullconf(const struct gre_soparm *sp)
1217 {
1218 	return sockaddr_is_anyaddr(sstocsa(&sp->sp_src)) ||
1219 	       sockaddr_is_anyaddr(sstocsa(&sp->sp_dst));
1220 }
1221 
1222 static void
1223 gre_clearconf(struct gre_soparm *sp, bool force)
1224 {
1225 	if (sp->sp_bysock || force) {
1226 		sockaddr_copy(sstosa(&sp->sp_src), sizeof(sp->sp_src),
1227 		    sockaddr_any(sstosa(&sp->sp_src)));
1228 		sockaddr_copy(sstosa(&sp->sp_dst), sizeof(sp->sp_dst),
1229 		    sockaddr_any(sstosa(&sp->sp_dst)));
1230 		sp->sp_bysock = false;
1231 	}
1232 	sp->sp_so = NULL; /* XXX */
1233 }
1234 
1235 static int
1236 gre_ioctl_lock(struct gre_softc *sc)
1237 {
1238 	mutex_enter(&sc->sc_mtx);
1239 
1240 	while (sc->sc_state == GRE_S_IOCTL)
1241 		gre_wait(sc);
1242 
1243 	if (sc->sc_state != GRE_S_IDLE) {
1244 		cv_signal(&sc->sc_condvar);
1245 		mutex_exit(&sc->sc_mtx);
1246 		GRE_DPRINTF(sc, "\n");
1247 		return ENXIO;
1248 	}
1249 
1250 	sc->sc_state = GRE_S_IOCTL;
1251 
1252 	mutex_exit(&sc->sc_mtx);
1253 	return 0;
1254 }
1255 
1256 static void
1257 gre_ioctl_unlock(struct gre_softc *sc)
1258 {
1259 	mutex_enter(&sc->sc_mtx);
1260 
1261 	KASSERT(sc->sc_state == GRE_S_IOCTL);
1262 	sc->sc_state = GRE_S_IDLE;
1263 	cv_signal(&sc->sc_condvar);
1264 
1265 	mutex_exit(&sc->sc_mtx);
1266 }
1267 
1268 static int
1269 gre_ioctl(struct ifnet *ifp, const u_long cmd, void *data)
1270 {
1271 	struct ifreq *ifr;
1272 	struct if_laddrreq *lifr = (struct if_laddrreq *)data;
1273 	struct gre_softc *sc = ifp->if_softc;
1274 	struct gre_soparm *sp;
1275 	int fd, error = 0, oproto, otype, s;
1276 	struct gre_soparm sp0;
1277 
1278 	ifr = data;
1279 
1280 	GRE_DPRINTF(sc, "cmd %lu\n", cmd);
1281 
1282 	switch (cmd) {
1283 	case SIOCSIFFLAGS:
1284 	case SIOCSIFMTU:
1285 	case GRESPROTO:
1286 	case GRESADDRD:
1287 	case GRESADDRS:
1288 	case GRESSOCK:
1289 	case GREDSOCK:
1290 	case SIOCSLIFPHYADDR:
1291 	case SIOCDIFPHYADDR:
1292 		if (kauth_authorize_network(curlwp->l_cred,
1293 		    KAUTH_NETWORK_INTERFACE,
1294 		    KAUTH_REQ_NETWORK_INTERFACE_SETPRIV, ifp, (void *)cmd,
1295 		    NULL) != 0)
1296 			return EPERM;
1297 		break;
1298 	default:
1299 		break;
1300 	}
1301 
1302 	if ((error = gre_ioctl_lock(sc)) != 0) {
1303 		GRE_DPRINTF(sc, "\n");
1304 		return error;
1305 	}
1306 	s = splnet();
1307 
1308 	sp0 = sc->sc_soparm;
1309 	sp0.sp_so = NULL;
1310 	sp = &sp0;
1311 
1312 	GRE_DPRINTF(sc, "\n");
1313 
1314 	switch (cmd) {
1315 	case SIOCINITIFADDR:
1316 		GRE_DPRINTF(sc, "\n");
1317 		if ((ifp->if_flags & IFF_UP) != 0)
1318 			break;
1319 		gre_clearconf(sp, false);
1320 		ifp->if_flags |= IFF_UP;
1321 		goto mksocket;
1322 	case SIOCSIFDSTADDR:
1323 		break;
1324 	case SIOCSIFFLAGS:
1325 		if ((error = ifioctl_common(ifp, cmd, data)) != 0)
1326 			break;
1327 		oproto = sp->sp_proto;
1328 		otype = sp->sp_type;
1329 		switch (ifr->ifr_flags & (IFF_LINK0|IFF_LINK2)) {
1330 		case IFF_LINK0|IFF_LINK2:
1331 			sp->sp_proto = IPPROTO_UDP;
1332 			sp->sp_type = SOCK_DGRAM;
1333 			break;
1334 		case IFF_LINK2:
1335 			sp->sp_proto = 0;
1336 			sp->sp_type = 0;
1337 			break;
1338 		case IFF_LINK0:
1339 			sp->sp_proto = IPPROTO_GRE;
1340 			sp->sp_type = SOCK_RAW;
1341 			break;
1342 		default:
1343 			GRE_DPRINTF(sc, "\n");
1344 			error = EINVAL;
1345 			goto out;
1346 		}
1347 		GRE_DPRINTF(sc, "\n");
1348 		gre_clearconf(sp, false);
1349 		if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) ==
1350 		    (IFF_UP|IFF_RUNNING) &&
1351 		    (oproto == sp->sp_proto || sp->sp_proto == 0) &&
1352 		    (otype == sp->sp_type || sp->sp_type == 0))
1353 			break;
1354 		switch (sp->sp_proto) {
1355 		case IPPROTO_UDP:
1356 		case IPPROTO_GRE:
1357 			goto mksocket;
1358 		default:
1359 			break;
1360 		}
1361 		break;
1362 	case SIOCSIFMTU:
1363 		/* XXX determine MTU automatically by probing w/
1364 		 * XXX do-not-fragment packets?
1365 		 */
1366 		if (ifr->ifr_mtu < 576) {
1367 			error = EINVAL;
1368 			break;
1369 		}
1370 		/*FALLTHROUGH*/
1371 	case SIOCGIFMTU:
1372 		if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET)
1373 			error = 0;
1374 		break;
1375 	case SIOCADDMULTI:
1376 	case SIOCDELMULTI:
1377 		if (ifr == NULL) {
1378 			error = EAFNOSUPPORT;
1379 			break;
1380 		}
1381 		switch (ifreq_getaddr(cmd, ifr)->sa_family) {
1382 #ifdef INET
1383 		case AF_INET:
1384 			break;
1385 #endif
1386 #ifdef INET6
1387 		case AF_INET6:
1388 			break;
1389 #endif
1390 		default:
1391 			error = EAFNOSUPPORT;
1392 			break;
1393 		}
1394 		break;
1395 	case GRESPROTO:
1396 		gre_clearconf(sp, false);
1397 		oproto = sp->sp_proto;
1398 		otype = sp->sp_type;
1399 		sp->sp_proto = ifr->ifr_flags;
1400 		switch (sp->sp_proto) {
1401 		case IPPROTO_UDP:
1402 			ifp->if_flags |= IFF_LINK0|IFF_LINK2;
1403 			sp->sp_type = SOCK_DGRAM;
1404 			break;
1405 		case IPPROTO_GRE:
1406 			ifp->if_flags |= IFF_LINK0;
1407 			ifp->if_flags &= ~IFF_LINK2;
1408 			sp->sp_type = SOCK_RAW;
1409 			break;
1410 		case 0:
1411 			ifp->if_flags &= ~IFF_LINK0;
1412 			ifp->if_flags |= IFF_LINK2;
1413 			sp->sp_type = 0;
1414 			break;
1415 		default:
1416 			error = EPROTONOSUPPORT;
1417 			break;
1418 		}
1419 		if ((oproto == sp->sp_proto || sp->sp_proto == 0) &&
1420 		    (otype == sp->sp_type || sp->sp_type == 0))
1421 			break;
1422 		switch (sp->sp_proto) {
1423 		case IPPROTO_UDP:
1424 		case IPPROTO_GRE:
1425 			goto mksocket;
1426 		default:
1427 			break;
1428 		}
1429 		break;
1430 	case GREGPROTO:
1431 		ifr->ifr_flags = sp->sp_proto;
1432 		break;
1433 	case GRESADDRS:
1434 	case GRESADDRD:
1435 		gre_clearconf(sp, false);
1436 		/* set tunnel endpoints and mark interface as up */
1437 		switch (cmd) {
1438 		case GRESADDRS:
1439 			sockaddr_copy(sstosa(&sp->sp_src),
1440 			    sizeof(sp->sp_src), ifreq_getaddr(cmd, ifr));
1441 			break;
1442 		case GRESADDRD:
1443 			sockaddr_copy(sstosa(&sp->sp_dst),
1444 			    sizeof(sp->sp_dst), ifreq_getaddr(cmd, ifr));
1445 			break;
1446 		}
1447 	checkaddr:
1448 		if (sockaddr_any(sstosa(&sp->sp_src)) == NULL ||
1449 		    sockaddr_any(sstosa(&sp->sp_dst)) == NULL) {
1450 			error = EINVAL;
1451 			break;
1452 		}
1453 		/* let gre_socreate() check the rest */
1454 	mksocket:
1455 		GRE_DPRINTF(sc, "\n");
1456 		/* If we're administratively down, or the configuration
1457 		 * is empty, there's no use creating a socket.
1458 		 */
1459 		if ((ifp->if_flags & IFF_UP) == 0 || gre_is_nullconf(sp))
1460 			goto sendconf;
1461 
1462 		GRE_DPRINTF(sc, "\n");
1463 		fd = 0;
1464 		error = gre_socreate(sc, sp, &fd);
1465 		if (error != 0)
1466 			break;
1467 
1468 	setsock:
1469 		GRE_DPRINTF(sc, "\n");
1470 
1471 		error = gre_ssock(ifp, sp, fd);
1472 
1473 		if (cmd != GRESSOCK) {
1474 			GRE_DPRINTF(sc, "\n");
1475 			/* XXX v. dodgy */
1476 			if (fd_getfile(fd) != NULL)
1477 				fd_close(fd);
1478 		}
1479 
1480 		if (error == 0) {
1481 	sendconf:
1482 			GRE_DPRINTF(sc, "\n");
1483 			ifp->if_flags &= ~IFF_RUNNING;
1484 			gre_reconf(sc, sp);
1485 		}
1486 
1487 		break;
1488 	case GREGADDRS:
1489 		ifreq_setaddr(cmd, ifr, sstosa(&sp->sp_src));
1490 		break;
1491 	case GREGADDRD:
1492 		ifreq_setaddr(cmd, ifr, sstosa(&sp->sp_dst));
1493 		break;
1494 	case GREDSOCK:
1495 		GRE_DPRINTF(sc, "\n");
1496 		if (sp->sp_bysock)
1497 			ifp->if_flags &= ~IFF_UP;
1498 		gre_clearconf(sp, false);
1499 		goto mksocket;
1500 	case GRESSOCK:
1501 		GRE_DPRINTF(sc, "\n");
1502 		gre_clearconf(sp, true);
1503 		fd = (int)ifr->ifr_value;
1504 		sp->sp_bysock = true;
1505 		ifp->if_flags |= IFF_UP;
1506 		goto setsock;
1507 	case SIOCSLIFPHYADDR:
1508 		GRE_DPRINTF(sc, "\n");
1509 		if (lifr->addr.ss_family != lifr->dstaddr.ss_family) {
1510 			error = EAFNOSUPPORT;
1511 			break;
1512 		}
1513 		sockaddr_copy(sstosa(&sp->sp_src), sizeof(sp->sp_src),
1514 		    sstosa(&lifr->addr));
1515 		sockaddr_copy(sstosa(&sp->sp_dst), sizeof(sp->sp_dst),
1516 		    sstosa(&lifr->dstaddr));
1517 		GRE_DPRINTF(sc, "\n");
1518 		goto checkaddr;
1519 	case SIOCDIFPHYADDR:
1520 		GRE_DPRINTF(sc, "\n");
1521 		gre_clearconf(sp, true);
1522 		ifp->if_flags &= ~IFF_UP;
1523 		goto mksocket;
1524 	case SIOCGLIFPHYADDR:
1525 		GRE_DPRINTF(sc, "\n");
1526 		if (gre_is_nullconf(sp)) {
1527 			error = EADDRNOTAVAIL;
1528 			break;
1529 		}
1530 		sockaddr_copy(sstosa(&lifr->addr), sizeof(lifr->addr),
1531 		    sstosa(&sp->sp_src));
1532 		sockaddr_copy(sstosa(&lifr->dstaddr), sizeof(lifr->dstaddr),
1533 		    sstosa(&sp->sp_dst));
1534 		GRE_DPRINTF(sc, "\n");
1535 		break;
1536 	default:
1537 		error = ifioctl_common(ifp, cmd, data);
1538 		break;
1539 	}
1540 out:
1541 	GRE_DPRINTF(sc, "\n");
1542 	splx(s);
1543 	gre_ioctl_unlock(sc);
1544 	return error;
1545 }
1546 
1547 void	greattach(int);
1548 
1549 /* ARGSUSED */
1550 void
1551 greattach(int count)
1552 {
1553 	if_clone_attach(&gre_cloner);
1554 }
1555