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source: rtems-libbsd/freebsd/sys/net/if_gre.c @ 6d9d7b1

55-freebsd-126-freebsd-12

Last change on this file since 6d9d7b1 was 3c967ca, checked in by Sebastian Huber <sebastian.huber@…>, on 06/08/17 at 11:15:12
Use <sys/lock.h> provided by Newlib
Property mode set to `100644`
File size: 22.7 KB

Line
1	#include <machine/rtems-bsd-kernel-space.h>
2
3	/*-
4	* Copyright (c) 1998 The NetBSD Foundation, Inc.
5	* Copyright (c) 2014 Andrey V. Elsukov <ae@FreeBSD.org>
6	* All rights reserved.
7	*
8	* This code is derived from software contributed to The NetBSD Foundation
9	* by Heiko W.Rupp <hwr@pilhuhn.de>
10	*
11	* IPv6-over-GRE contributed by Gert Doering <gert@greenie.muc.de>
12	*
13	* Redistribution and use in source and binary forms, with or without
14	* modification, are permitted provided that the following conditions
15	* are met:
16	* 1. Redistributions of source code must retain the above copyright
17	* notice, this list of conditions and the following disclaimer.
18	* 2. Redistributions in binary form must reproduce the above copyright
19	* notice, this list of conditions and the following disclaimer in the
20	* documentation and/or other materials provided with the distribution.
21	*
22	* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
23	* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
24	* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
25	* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
26	* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
30	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
31	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32	* POSSIBILITY OF SUCH DAMAGE.
33	*
34	* $NetBSD: if_gre.c,v 1.49 2003/12/11 00:22:29 itojun Exp $
35	*/
36
37	#include <sys/cdefs.h>
38	__FBSDID("$FreeBSD$");
39
40	#include <rtems/bsd/local/opt_inet.h>
41	#include <rtems/bsd/local/opt_inet6.h>
42
43	#include <sys/param.h>
44	#include <sys/jail.h>
45	#include <sys/kernel.h>
46	#include <sys/lock.h>
47	#include <sys/libkern.h>
48	#include <sys/malloc.h>
49	#include <sys/module.h>
50	#include <sys/mbuf.h>
51	#include <sys/priv.h>
52	#include <sys/proc.h>
53	#include <sys/protosw.h>
54	#include <sys/rmlock.h>
55	#include <sys/socket.h>
56	#include <sys/sockio.h>
57	#include <sys/sx.h>
58	#include <sys/sysctl.h>
59	#include <sys/syslog.h>
60	#include <sys/systm.h>
61
62	#include <net/ethernet.h>
63	#include <net/if.h>
64	#include <net/if_var.h>
65	#include <net/if_clone.h>
66	#include <net/if_types.h>
67	#include <net/netisr.h>
68	#include <net/vnet.h>
69	#include <net/route.h>
70
71	#include <netinet/in.h>
72	#ifdef INET
73	#include <netinet/in_systm.h>
74	#include <netinet/in_var.h>
75	#include <netinet/ip.h>
76	#include <netinet/ip_var.h>
77	#endif
78
79	#ifdef INET6
80	#include <netinet/ip6.h>
81	#include <netinet6/in6_var.h>
82	#include <netinet6/ip6_var.h>
83	#include <netinet6/scope6_var.h>
84	#endif
85
86	#include <netinet/ip_encap.h>
87	#include <net/bpf.h>
88	#include <net/if_gre.h>
89
90	#include <machine/in_cksum.h>
91	#include <security/mac/mac_framework.h>
92
93	#define GREMTU 1500
94	static const char grename[] = "gre";
95	static MALLOC_DEFINE(M_GRE, grename, "Generic Routing Encapsulation");
96	static VNET_DEFINE(struct mtx, gre_mtx);
97	#define V_gre_mtx VNET(gre_mtx)
98	#define GRE_LIST_LOCK_INIT(x) mtx_init(&V_gre_mtx, "gre_mtx", NULL, \
99	MTX_DEF)
100	#define GRE_LIST_LOCK_DESTROY(x) mtx_destroy(&V_gre_mtx)
101	#define GRE_LIST_LOCK(x) mtx_lock(&V_gre_mtx)
102	#define GRE_LIST_UNLOCK(x) mtx_unlock(&V_gre_mtx)
103
104	static VNET_DEFINE(LIST_HEAD(, gre_softc), gre_softc_list);
105	#define V_gre_softc_list VNET(gre_softc_list)
106	static struct sx gre_ioctl_sx;
107	SX_SYSINIT(gre_ioctl_sx, &gre_ioctl_sx, "gre_ioctl");
108
109	static int gre_clone_create(struct if_clone *, int, caddr_t);
110	static void gre_clone_destroy(struct ifnet *);
111	static VNET_DEFINE(struct if_clone *, gre_cloner);
112	#define V_gre_cloner VNET(gre_cloner)
113
114	static void gre_qflush(struct ifnet *);
115	static int gre_transmit(struct ifnet , struct mbuf );
116	static int gre_ioctl(struct ifnet *, u_long, caddr_t);
117	static int gre_output(struct ifnet , struct mbuf ,
118	const struct sockaddr , struct route );
119
120	static void gre_updatehdr(struct gre_softc *);
121	static int gre_set_tunnel(struct ifnet , struct sockaddr ,
122	struct sockaddr *);
123	static void gre_delete_tunnel(struct ifnet *);
124
125	SYSCTL_DECL(_net_link);
126	static SYSCTL_NODE(_net_link, IFT_TUNNEL, gre, CTLFLAG_RW, 0,
127	"Generic Routing Encapsulation");
128	#ifndef MAX_GRE_NEST
129	/*
130	* This macro controls the default upper limitation on nesting of gre tunnels.
131	* Since, setting a large value to this macro with a careless configuration
132	* may introduce system crash, we don't allow any nestings by default.
133	* If you need to configure nested gre tunnels, you can define this macro
134	* in your kernel configuration file. However, if you do so, please be
135	* careful to configure the tunnels so that it won't make a loop.
136	*/
137	#define MAX_GRE_NEST 1
138	#endif
139
140	static VNET_DEFINE(int, max_gre_nesting) = MAX_GRE_NEST;
141	#define V_max_gre_nesting VNET(max_gre_nesting)
142	SYSCTL_INT(_net_link_gre, OID_AUTO, max_nesting, CTLFLAG_RW \| CTLFLAG_VNET,
143	&VNET_NAME(max_gre_nesting), 0, "Max nested tunnels");
144
145	static void
146	vnet_gre_init(const void *unused __unused)
147	{
148	LIST_INIT(&V_gre_softc_list);
149	GRE_LIST_LOCK_INIT();
150	V_gre_cloner = if_clone_simple(grename, gre_clone_create,
151	gre_clone_destroy, 0);
152	}
153	VNET_SYSINIT(vnet_gre_init, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
154	vnet_gre_init, NULL);
155
156	static void
157	vnet_gre_uninit(const void *unused __unused)
158	{
159
160	if_clone_detach(V_gre_cloner);
161	GRE_LIST_LOCK_DESTROY();
162	}
163	VNET_SYSUNINIT(vnet_gre_uninit, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
164	vnet_gre_uninit, NULL);
165
166	static int
167	gre_clone_create(struct if_clone *ifc, int unit, caddr_t params)
168	{
169	struct gre_softc *sc;
170
171	sc = malloc(sizeof(struct gre_softc), M_GRE, M_WAITOK \| M_ZERO);
172	#ifndef __rtems__
173	sc->gre_fibnum = curthread->td_proc->p_fibnum;
174	#else /* __rtems__ */
175	sc->gre_fibnum = BSD_DEFAULT_FIB;
176	#endif /* __rtems__ */
177	GRE2IFP(sc) = if_alloc(IFT_TUNNEL);
178	GRE_LOCK_INIT(sc);
179	GRE2IFP(sc)->if_softc = sc;
180	if_initname(GRE2IFP(sc), grename, unit);
181
182	GRE2IFP(sc)->if_mtu = sc->gre_mtu = GREMTU;
183	GRE2IFP(sc)->if_flags = IFF_POINTOPOINT\|IFF_MULTICAST;
184	GRE2IFP(sc)->if_output = gre_output;
185	GRE2IFP(sc)->if_ioctl = gre_ioctl;
186	GRE2IFP(sc)->if_transmit = gre_transmit;
187	GRE2IFP(sc)->if_qflush = gre_qflush;
188	GRE2IFP(sc)->if_capabilities \|= IFCAP_LINKSTATE;
189	GRE2IFP(sc)->if_capenable \|= IFCAP_LINKSTATE;
190	if_attach(GRE2IFP(sc));
191	bpfattach(GRE2IFP(sc), DLT_NULL, sizeof(u_int32_t));
192	GRE_LIST_LOCK();
193	LIST_INSERT_HEAD(&V_gre_softc_list, sc, gre_list);
194	GRE_LIST_UNLOCK();
195	return (0);
196	}
197
198	static void
199	gre_clone_destroy(struct ifnet *ifp)
200	{
201	struct gre_softc *sc;
202
203	sx_xlock(&gre_ioctl_sx);
204	sc = ifp->if_softc;
205	gre_delete_tunnel(ifp);
206	GRE_LIST_LOCK();
207	LIST_REMOVE(sc, gre_list);
208	GRE_LIST_UNLOCK();
209	bpfdetach(ifp);
210	if_detach(ifp);
211	ifp->if_softc = NULL;
212	sx_xunlock(&gre_ioctl_sx);
213
214	if_free(ifp);
215	GRE_LOCK_DESTROY(sc);
216	free(sc, M_GRE);
217	}
218
219	static int
220	gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
221	{
222	GRE_RLOCK_TRACKER;
223	struct ifreq ifr = (struct ifreq )data;
224	struct sockaddr src, dst;
225	struct gre_softc *sc;
226	#ifdef INET
227	struct sockaddr_in *sin = NULL;
228	#endif
229	#ifdef INET6
230	struct sockaddr_in6 *sin6 = NULL;
231	#endif
232	uint32_t opt;
233	int error;
234
235	switch (cmd) {
236	case SIOCSIFMTU:
237	/* XXX: */
238	if (ifr->ifr_mtu < 576)
239	return (EINVAL);
240	break;
241	case SIOCSIFADDR:
242	ifp->if_flags \|= IFF_UP;
243	case SIOCSIFFLAGS:
244	case SIOCADDMULTI:
245	case SIOCDELMULTI:
246	return (0);
247	case GRESADDRS:
248	case GRESADDRD:
249	case GREGADDRS:
250	case GREGADDRD:
251	case GRESPROTO:
252	case GREGPROTO:
253	return (EOPNOTSUPP);
254	}
255	src = dst = NULL;
256	sx_xlock(&gre_ioctl_sx);
257	sc = ifp->if_softc;
258	if (sc == NULL) {
259	error = ENXIO;
260	goto end;
261	}
262	error = 0;
263	switch (cmd) {
264	case SIOCSIFMTU:
265	GRE_WLOCK(sc);
266	sc->gre_mtu = ifr->ifr_mtu;
267	gre_updatehdr(sc);
268	GRE_WUNLOCK(sc);
269	goto end;
270	case SIOCSIFPHYADDR:
271	#ifdef INET6
272	case SIOCSIFPHYADDR_IN6:
273	#endif
274	error = EINVAL;
275	switch (cmd) {
276	#ifdef INET
277	case SIOCSIFPHYADDR:
278	src = (struct sockaddr *)
279	&(((struct in_aliasreq *)data)->ifra_addr);
280	dst = (struct sockaddr *)
281	&(((struct in_aliasreq *)data)->ifra_dstaddr);
282	break;
283	#endif
284	#ifdef INET6
285	case SIOCSIFPHYADDR_IN6:
286	src = (struct sockaddr *)
287	&(((struct in6_aliasreq *)data)->ifra_addr);
288	dst = (struct sockaddr *)
289	&(((struct in6_aliasreq *)data)->ifra_dstaddr);
290	break;
291	#endif
292	default:
293	error = EAFNOSUPPORT;
294	goto end;
295	}
296	/* sa_family must be equal */
297	if (src->sa_family != dst->sa_family \|\|
298	src->sa_len != dst->sa_len)
299	goto end;
300
301	/* validate sa_len */
302	switch (src->sa_family) {
303	#ifdef INET
304	case AF_INET:
305	if (src->sa_len != sizeof(struct sockaddr_in))
306	goto end;
307	break;
308	#endif
309	#ifdef INET6
310	case AF_INET6:
311	if (src->sa_len != sizeof(struct sockaddr_in6))
312	goto end;
313	break;
314	#endif
315	default:
316	error = EAFNOSUPPORT;
317	goto end;
318	}
319	/* check sa_family looks sane for the cmd */
320	error = EAFNOSUPPORT;
321	switch (cmd) {
322	#ifdef INET
323	case SIOCSIFPHYADDR:
324	if (src->sa_family == AF_INET)
325	break;
326	goto end;
327	#endif
328	#ifdef INET6
329	case SIOCSIFPHYADDR_IN6:
330	if (src->sa_family == AF_INET6)
331	break;
332	goto end;
333	#endif
334	}
335	error = EADDRNOTAVAIL;
336	switch (src->sa_family) {
337	#ifdef INET
338	case AF_INET:
339	if (satosin(src)->sin_addr.s_addr == INADDR_ANY \|\|
340	satosin(dst)->sin_addr.s_addr == INADDR_ANY)
341	goto end;
342	break;
343	#endif
344	#ifdef INET6
345	case AF_INET6:
346	if (IN6_IS_ADDR_UNSPECIFIED(&satosin6(src)->sin6_addr)
347	\|\|
348	IN6_IS_ADDR_UNSPECIFIED(&satosin6(dst)->sin6_addr))
349	goto end;
350	/*
351	* Check validity of the scope zone ID of the
352	* addresses, and convert it into the kernel
353	* internal form if necessary.
354	*/
355	error = sa6_embedscope(satosin6(src), 0);
356	if (error != 0)
357	goto end;
358	error = sa6_embedscope(satosin6(dst), 0);
359	if (error != 0)
360	goto end;
361	#endif
362	}
363	error = gre_set_tunnel(ifp, src, dst);
364	break;
365	case SIOCDIFPHYADDR:
366	gre_delete_tunnel(ifp);
367	break;
368	case SIOCGIFPSRCADDR:
369	case SIOCGIFPDSTADDR:
370	#ifdef INET6
371	case SIOCGIFPSRCADDR_IN6:
372	case SIOCGIFPDSTADDR_IN6:
373	#endif
374	if (sc->gre_family == 0) {
375	error = EADDRNOTAVAIL;
376	break;
377	}
378	GRE_RLOCK(sc);
379	switch (cmd) {
380	#ifdef INET
381	case SIOCGIFPSRCADDR:
382	case SIOCGIFPDSTADDR:
383	if (sc->gre_family != AF_INET) {
384	error = EADDRNOTAVAIL;
385	break;
386	}
387	sin = (struct sockaddr_in *)&ifr->ifr_addr;
388	memset(sin, 0, sizeof(*sin));
389	sin->sin_family = AF_INET;
390	sin->sin_len = sizeof(*sin);
391	break;
392	#endif
393	#ifdef INET6
394	case SIOCGIFPSRCADDR_IN6:
395	case SIOCGIFPDSTADDR_IN6:
396	if (sc->gre_family != AF_INET6) {
397	error = EADDRNOTAVAIL;
398	break;
399	}
400	sin6 = (struct sockaddr_in6 *)
401	&(((struct in6_ifreq *)data)->ifr_addr);
402	memset(sin6, 0, sizeof(*sin6));
403	sin6->sin6_family = AF_INET6;
404	sin6->sin6_len = sizeof(*sin6);
405	break;
406	#endif
407	}
408	if (error == 0) {
409	switch (cmd) {
410	#ifdef INET
411	case SIOCGIFPSRCADDR:
412	sin->sin_addr = sc->gre_oip.ip_src;
413	break;
414	case SIOCGIFPDSTADDR:
415	sin->sin_addr = sc->gre_oip.ip_dst;
416	break;
417	#endif
418	#ifdef INET6
419	case SIOCGIFPSRCADDR_IN6:
420	sin6->sin6_addr = sc->gre_oip6.ip6_src;
421	break;
422	case SIOCGIFPDSTADDR_IN6:
423	sin6->sin6_addr = sc->gre_oip6.ip6_dst;
424	break;
425	#endif
426	}
427	}
428	GRE_RUNLOCK(sc);
429	if (error != 0)
430	break;
431	switch (cmd) {
432	#ifdef INET
433	case SIOCGIFPSRCADDR:
434	case SIOCGIFPDSTADDR:
435	error = prison_if(curthread->td_ucred,
436	(struct sockaddr *)sin);
437	if (error != 0)
438	memset(sin, 0, sizeof(*sin));
439	break;
440	#endif
441	#ifdef INET6
442	case SIOCGIFPSRCADDR_IN6:
443	case SIOCGIFPDSTADDR_IN6:
444	error = prison_if(curthread->td_ucred,
445	(struct sockaddr *)sin6);
446	if (error == 0)
447	error = sa6_recoverscope(sin6);
448	if (error != 0)
449	memset(sin6, 0, sizeof(*sin6));
450	#endif
451	}
452	break;
453	case SIOCGTUNFIB:
454	ifr->ifr_fib = sc->gre_fibnum;
455	break;
456	case SIOCSTUNFIB:
457	if ((error = priv_check(curthread, PRIV_NET_GRE)) != 0)
458	break;
459	if (ifr->ifr_fib >= rt_numfibs)
460	error = EINVAL;
461	else
462	sc->gre_fibnum = ifr->ifr_fib;
463	break;
464	case GRESKEY:
465	if ((error = priv_check(curthread, PRIV_NET_GRE)) != 0)
466	break;
467	if ((error = copyin(ifr->ifr_data, &opt, sizeof(opt))) != 0)
468	break;
469	if (sc->gre_key != opt) {
470	GRE_WLOCK(sc);
471	sc->gre_key = opt;
472	gre_updatehdr(sc);
473	GRE_WUNLOCK(sc);
474	}
475	break;
476	case GREGKEY:
477	error = copyout(&sc->gre_key, ifr->ifr_data,
478	sizeof(sc->gre_key));
479	break;
480	case GRESOPTS:
481	if ((error = priv_check(curthread, PRIV_NET_GRE)) != 0)
482	break;
483	if ((error = copyin(ifr->ifr_data, &opt, sizeof(opt))) != 0)
484	break;
485	if (opt & ~GRE_OPTMASK)
486	error = EINVAL;
487	else {
488	if (sc->gre_options != opt) {
489	GRE_WLOCK(sc);
490	sc->gre_options = opt;
491	gre_updatehdr(sc);
492	GRE_WUNLOCK(sc);
493	}
494	}
495	break;
496
497	case GREGOPTS:
498	error = copyout(&sc->gre_options, ifr->ifr_data,
499	sizeof(sc->gre_options));
500	break;
501	default:
502	error = EINVAL;
503	break;
504	}
505	end:
506	sx_xunlock(&gre_ioctl_sx);
507	return (error);
508	}
509
510	static void
511	gre_updatehdr(struct gre_softc *sc)
512	{
513	struct grehdr *gh = NULL;
514	uint32_t *opts;
515	uint16_t flags;
516
517	GRE_WLOCK_ASSERT(sc);
518	switch (sc->gre_family) {
519	#ifdef INET
520	case AF_INET:
521	sc->gre_hlen = sizeof(struct greip);
522	sc->gre_oip.ip_v = IPPROTO_IPV4;
523	sc->gre_oip.ip_hl = sizeof(struct ip) >> 2;
524	sc->gre_oip.ip_p = IPPROTO_GRE;
525	gh = &sc->gre_gihdr->gi_gre;
526	break;
527	#endif
528	#ifdef INET6
529	case AF_INET6:
530	sc->gre_hlen = sizeof(struct greip6);
531	sc->gre_oip6.ip6_vfc = IPV6_VERSION;
532	sc->gre_oip6.ip6_nxt = IPPROTO_GRE;
533	gh = &sc->gre_gi6hdr->gi6_gre;
534	break;
535	#endif
536	default:
537	return;
538	}
539	flags = 0;
540	opts = gh->gre_opts;
541	if (sc->gre_options & GRE_ENABLE_CSUM) {
542	flags \|= GRE_FLAGS_CP;
543	sc->gre_hlen += 2 * sizeof(uint16_t);
544	*opts++ = 0;
545	}
546	if (sc->gre_key != 0) {
547	flags \|= GRE_FLAGS_KP;
548	sc->gre_hlen += sizeof(uint32_t);
549	*opts++ = htonl(sc->gre_key);
550	}
551	if (sc->gre_options & GRE_ENABLE_SEQ) {
552	flags \|= GRE_FLAGS_SP;
553	sc->gre_hlen += sizeof(uint32_t);
554	*opts++ = 0;
555	} else
556	sc->gre_oseq = 0;
557	gh->gre_flags = htons(flags);
558	GRE2IFP(sc)->if_mtu = sc->gre_mtu - sc->gre_hlen;
559	}
560
561	static void
562	gre_detach(struct gre_softc *sc)
563	{
564
565	sx_assert(&gre_ioctl_sx, SA_XLOCKED);
566	if (sc->gre_ecookie != NULL)
567	encap_detach(sc->gre_ecookie);
568	sc->gre_ecookie = NULL;
569	}
570
571	static int
572	gre_set_tunnel(struct ifnet ifp, struct sockaddr src,
573	struct sockaddr *dst)
574	{
575	struct gre_softc sc, tsc;
576	#ifdef INET6
577	struct ip6_hdr *ip6;
578	#endif
579	#ifdef INET
580	struct ip *ip;
581	#endif
582	void *hdr;
583	int error;
584
585	sx_assert(&gre_ioctl_sx, SA_XLOCKED);
586	GRE_LIST_LOCK();
587	sc = ifp->if_softc;
588	LIST_FOREACH(tsc, &V_gre_softc_list, gre_list) {
589	if (tsc == sc \|\| tsc->gre_family != src->sa_family)
590	continue;
591	#ifdef INET
592	if (tsc->gre_family == AF_INET &&
593	tsc->gre_oip.ip_src.s_addr ==
594	satosin(src)->sin_addr.s_addr &&
595	tsc->gre_oip.ip_dst.s_addr ==
596	satosin(dst)->sin_addr.s_addr) {
597	GRE_LIST_UNLOCK();
598	return (EADDRNOTAVAIL);
599	}
600	#endif
601	#ifdef INET6
602	if (tsc->gre_family == AF_INET6 &&
603	IN6_ARE_ADDR_EQUAL(&tsc->gre_oip6.ip6_src,
604	&satosin6(src)->sin6_addr) &&
605	IN6_ARE_ADDR_EQUAL(&tsc->gre_oip6.ip6_dst,
606	&satosin6(dst)->sin6_addr)) {
607	GRE_LIST_UNLOCK();
608	return (EADDRNOTAVAIL);
609	}
610	#endif
611	}
612	GRE_LIST_UNLOCK();
613
614	switch (src->sa_family) {
615	#ifdef INET
616	case AF_INET:
617	hdr = ip = malloc(sizeof(struct greip) +
618	3 * sizeof(uint32_t), M_GRE, M_WAITOK \| M_ZERO);
619	ip->ip_src = satosin(src)->sin_addr;
620	ip->ip_dst = satosin(dst)->sin_addr;
621	break;
622	#endif
623	#ifdef INET6
624	case AF_INET6:
625	hdr = ip6 = malloc(sizeof(struct greip6) +
626	3 * sizeof(uint32_t), M_GRE, M_WAITOK \| M_ZERO);
627	ip6->ip6_src = satosin6(src)->sin6_addr;
628	ip6->ip6_dst = satosin6(dst)->sin6_addr;
629	break;
630	#endif
631	default:
632	return (EAFNOSUPPORT);
633	}
634	if (sc->gre_family != 0)
635	gre_detach(sc);
636	GRE_WLOCK(sc);
637	if (sc->gre_family != 0)
638	free(sc->gre_hdr, M_GRE);
639	sc->gre_family = src->sa_family;
640	sc->gre_hdr = hdr;
641	sc->gre_oseq = 0;
642	sc->gre_iseq = UINT32_MAX;
643	gre_updatehdr(sc);
644	GRE_WUNLOCK(sc);
645
646	error = 0;
647	switch (src->sa_family) {
648	#ifdef INET
649	case AF_INET:
650	error = in_gre_attach(sc);
651	break;
652	#endif
653	#ifdef INET6
654	case AF_INET6:
655	error = in6_gre_attach(sc);
656	break;
657	#endif
658	}
659	if (error == 0) {
660	ifp->if_drv_flags \|= IFF_DRV_RUNNING;
661	if_link_state_change(ifp, LINK_STATE_UP);
662	}
663	return (error);
664	}
665
666	static void
667	gre_delete_tunnel(struct ifnet *ifp)
668	{
669	struct gre_softc *sc = ifp->if_softc;
670	int family;
671
672	GRE_WLOCK(sc);
673	family = sc->gre_family;
674	sc->gre_family = 0;
675	GRE_WUNLOCK(sc);
676	if (family != 0) {
677	gre_detach(sc);
678	free(sc->gre_hdr, M_GRE);
679	}
680	ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
681	if_link_state_change(ifp, LINK_STATE_DOWN);
682	}
683
684	int
685	gre_input(struct mbuf *mp, int offp, int proto)
686	{
687	struct gre_softc *sc;
688	struct grehdr *gh;
689	struct ifnet *ifp;
690	struct mbuf *m;
691	uint32_t *opts;
692	#ifdef notyet
693	uint32_t key;
694	#endif
695	uint16_t flags;
696	int hlen, isr, af;
697
698	m = *mp;
699	sc = encap_getarg(m);
700	KASSERT(sc != NULL, ("encap_getarg returned NULL"));
701
702	ifp = GRE2IFP(sc);
703	hlen = offp + sizeof(struct grehdr) + 4 sizeof(uint32_t);
704	if (m->m_pkthdr.len < hlen)
705	goto drop;
706	if (m->m_len < hlen) {
707	m = m_pullup(m, hlen);
708	if (m == NULL)
709	goto drop;
710	}
711	gh = (struct grehdr )mtodo(m, offp);
712	flags = ntohs(gh->gre_flags);
713	if (flags & ~GRE_FLAGS_MASK)
714	goto drop;
715	opts = gh->gre_opts;
716	hlen = 2 * sizeof(uint16_t);
717	if (flags & GRE_FLAGS_CP) {
718	/* reserved1 field must be zero */
719	if (((uint16_t *)opts)[1] != 0)
720	goto drop;
721	if (in_cksum_skip(m, m->m_pkthdr.len, *offp) != 0)
722	goto drop;
723	hlen += 2 * sizeof(uint16_t);
724	opts++;
725	}
726	if (flags & GRE_FLAGS_KP) {
727	#ifdef notyet
728	/*
729	* XXX: The current implementation uses the key only for outgoing
730	* packets. But we can check the key value here, or even in the
731	* encapcheck function.
732	*/
733	key = ntohl(*opts);
734	#endif
735	hlen += sizeof(uint32_t);
736	opts++;
737	}
738	#ifdef notyet
739	} else
740	key = 0;
741
742	if (sc->gre_key != 0 && (key != sc->gre_key \|\| key != 0))
743	goto drop;
744	#endif
745	if (flags & GRE_FLAGS_SP) {
746	#ifdef notyet
747	seq = ntohl(*opts);
748	#endif
749	hlen += sizeof(uint32_t);
750	}
751	switch (ntohs(gh->gre_proto)) {
752	case ETHERTYPE_WCCP:
753	/*
754	* For WCCP skip an additional 4 bytes if after GRE header
755	* doesn't follow an IP header.
756	*/
757	if (flags == 0 && ((uint8_t )gh->gre_opts & 0xF0) != 0x40)
758	hlen += sizeof(uint32_t);
759	/* FALLTHROUGH */
760	case ETHERTYPE_IP:
761	isr = NETISR_IP;
762	af = AF_INET;
763	break;
764	case ETHERTYPE_IPV6:
765	isr = NETISR_IPV6;
766	af = AF_INET6;
767	break;
768	default:
769	goto drop;
770	}
771	m_adj(m, *offp + hlen);
772	m_clrprotoflags(m);
773	m->m_pkthdr.rcvif = ifp;
774	M_SETFIB(m, ifp->if_fib);
775	#ifdef MAC
776	mac_ifnet_create_mbuf(ifp, m);
777	#endif
778	BPF_MTAP2(ifp, &af, sizeof(af), m);
779	if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
780	if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
781	if ((ifp->if_flags & IFF_MONITOR) != 0)
782	m_freem(m);
783	else
784	netisr_dispatch(isr, m);
785	return (IPPROTO_DONE);
786	drop:
787	if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
788	m_freem(m);
789	return (IPPROTO_DONE);
790	}
791
792	#define MTAG_GRE 1307983903
793	static int
794	gre_check_nesting(struct ifnet ifp, struct mbuf m)
795	{
796	struct m_tag *mtag;
797	int count;
798
799	count = 1;
800	mtag = NULL;
801	while ((mtag = m_tag_locate(m, MTAG_GRE, 0, mtag)) != NULL) {
802	if ((struct ifnet *)(mtag + 1) == ifp) {
803	log(LOG_NOTICE, "%s: loop detected\n", ifp->if_xname);
804	return (EIO);
805	}
806	count++;
807	}
808	if (count > V_max_gre_nesting) {
809	log(LOG_NOTICE,
810	"%s: if_output recursively called too many times(%d)\n",
811	ifp->if_xname, count);
812	return (EIO);
813	}
814	mtag = m_tag_alloc(MTAG_GRE, 0, sizeof(struct ifnet *), M_NOWAIT);
815	if (mtag == NULL)
816	return (ENOMEM);
817	(struct ifnet *)(mtag + 1) = ifp;
818	m_tag_prepend(m, mtag);
819	return (0);
820	}
821
822	static int
823	gre_output(struct ifnet ifp, struct mbuf m, const struct sockaddr *dst,
824	struct route *ro)
825	{
826	uint32_t af;
827	int error;
828
829	#ifdef MAC
830	error = mac_ifnet_check_transmit(ifp, m);
831	if (error != 0)
832	goto drop;
833	#endif
834	if ((ifp->if_flags & IFF_MONITOR) != 0 \|\|
835	(ifp->if_flags & IFF_UP) == 0) {
836	error = ENETDOWN;
837	goto drop;
838	}
839
840	error = gre_check_nesting(ifp, m);
841	if (error != 0)
842	goto drop;
843
844	m->m_flags &= ~(M_BCAST\|M_MCAST);
845	if (dst->sa_family == AF_UNSPEC)
846	bcopy(dst->sa_data, &af, sizeof(af));
847	else
848	af = dst->sa_family;
849	BPF_MTAP2(ifp, &af, sizeof(af), m);
850	m->m_pkthdr.csum_data = af; /* save af for if_transmit */
851	return (ifp->if_transmit(ifp, m));
852	drop:
853	m_freem(m);
854	if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
855	return (error);
856	}
857
858	static void
859	gre_setseqn(struct grehdr *gh, uint32_t seq)
860	{
861	uint32_t *opts;
862	uint16_t flags;
863
864	opts = gh->gre_opts;
865	flags = ntohs(gh->gre_flags);
866	KASSERT((flags & GRE_FLAGS_SP) != 0,
867	("gre_setseqn called, but GRE_FLAGS_SP isn't set "));
868	if (flags & GRE_FLAGS_CP)
869	opts++;
870	if (flags & GRE_FLAGS_KP)
871	opts++;
872	*opts = htonl(seq);
873	}
874
875	static int
876	gre_transmit(struct ifnet ifp, struct mbuf m)
877	{
878	GRE_RLOCK_TRACKER;
879	struct gre_softc *sc;
880	struct grehdr *gh;
881	uint32_t iaf, oaf, oseq;
882	int error, hlen, olen, plen;
883	int want_seq, want_csum;
884
885	plen = 0;
886	sc = ifp->if_softc;
887	if (sc == NULL) {
888	error = ENETDOWN;
889	m_freem(m);
890	goto drop;
891	}
892	GRE_RLOCK(sc);
893	if (sc->gre_family == 0) {
894	GRE_RUNLOCK(sc);
895	error = ENETDOWN;
896	m_freem(m);
897	goto drop;
898	}
899	iaf = m->m_pkthdr.csum_data;
900	oaf = sc->gre_family;
901	hlen = sc->gre_hlen;
902	want_seq = (sc->gre_options & GRE_ENABLE_SEQ) != 0;
903	if (want_seq)
904	oseq = sc->gre_oseq++; /* XXX */
905	else
906	oseq = 0; /* Make compiler happy. */
907	want_csum = (sc->gre_options & GRE_ENABLE_CSUM) != 0;
908	M_SETFIB(m, sc->gre_fibnum);
909	M_PREPEND(m, hlen, M_NOWAIT);
910	if (m == NULL) {
911	GRE_RUNLOCK(sc);
912	error = ENOBUFS;
913	goto drop;
914	}
915	bcopy(sc->gre_hdr, mtod(m, void *), hlen);
916	GRE_RUNLOCK(sc);
917	switch (oaf) {
918	#ifdef INET
919	case AF_INET:
920	olen = sizeof(struct ip);
921	break;
922	#endif
923	#ifdef INET6
924	case AF_INET6:
925	olen = sizeof(struct ip6_hdr);
926	break;
927	#endif
928	default:
929	error = ENETDOWN;
930	goto drop;
931	}
932	gh = (struct grehdr *)mtodo(m, olen);
933	switch (iaf) {
934	#ifdef INET
935	case AF_INET:
936	gh->gre_proto = htons(ETHERTYPE_IP);
937	break;
938	#endif
939	#ifdef INET6
940	case AF_INET6:
941	gh->gre_proto = htons(ETHERTYPE_IPV6);
942	break;
943	#endif
944	default:
945	error = ENETDOWN;
946	goto drop;
947	}
948	if (want_seq)
949	gre_setseqn(gh, oseq);
950	if (want_csum) {
951	(uint16_t )gh->gre_opts = in_cksum_skip(m,
952	m->m_pkthdr.len, olen);
953	}
954	plen = m->m_pkthdr.len - hlen;
955	switch (oaf) {
956	#ifdef INET
957	case AF_INET:
958	error = in_gre_output(m, iaf, hlen);
959	break;
960	#endif
961	#ifdef INET6
962	case AF_INET6:
963	error = in6_gre_output(m, iaf, hlen);
964	break;
965	#endif
966	default:
967	m_freem(m);
968	error = ENETDOWN;
969	}
970	drop:
971	if (error)
972	if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
973	else {
974	if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
975	if_inc_counter(ifp, IFCOUNTER_OBYTES, plen);
976	}
977	return (error);
978	}
979
980	static void
981	gre_qflush(struct ifnet *ifp __unused)
982	{
983
984	}
985
986	static int
987	gremodevent(module_t mod, int type, void *data)
988	{
989
990	switch (type) {
991	case MOD_LOAD:
992	case MOD_UNLOAD:
993	break;
994	default:
995	return (EOPNOTSUPP);
996	}
997	return (0);
998	}
999
1000	static moduledata_t gre_mod = {
1001	"if_gre",
1002	gremodevent,
1003	0
1004	};
1005
1006	DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
1007	MODULE_VERSION(if_gre, 1);

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