FreeBSD/Linux Kernel Cross Reference
sys/net/if_gre.c
1 /*-
2 * Copyright (c) 1998 The NetBSD Foundation, Inc.
3 * Copyright (c) 2014 Andrey V. Elsukov <ae@FreeBSD.org>
4 * All rights reserved.
5 *
6 * This code is derived from software contributed to The NetBSD Foundation
7 * by Heiko W.Rupp <hwr@pilhuhn.de>
8 *
9 * IPv6-over-GRE contributed by Gert Doering <gert@greenie.muc.de>
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 *
32 * $NetBSD: if_gre.c,v 1.49 2003/12/11 00:22:29 itojun Exp $
33 */
34
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD$");
37
38 #include "opt_inet.h"
39 #include "opt_inet6.h"
40
41 #include <sys/param.h>
42 #include <sys/jail.h>
43 #include <sys/kernel.h>
44 #include <sys/lock.h>
45 #include <sys/libkern.h>
46 #include <sys/malloc.h>
47 #include <sys/module.h>
48 #include <sys/mbuf.h>
49 #include <sys/priv.h>
50 #include <sys/proc.h>
51 #include <sys/protosw.h>
52 #include <sys/rmlock.h>
53 #include <sys/socket.h>
54 #include <sys/sockio.h>
55 #include <sys/sx.h>
56 #include <sys/sysctl.h>
57 #include <sys/syslog.h>
58 #include <sys/systm.h>
59
60 #include <net/ethernet.h>
61 #include <net/if.h>
62 #include <net/if_var.h>
63 #include <net/if_clone.h>
64 #include <net/if_types.h>
65 #include <net/netisr.h>
66 #include <net/vnet.h>
67 #include <net/route.h>
68
69 #include <netinet/in.h>
70 #ifdef INET
71 #include <netinet/in_systm.h>
72 #include <netinet/in_var.h>
73 #include <netinet/ip.h>
74 #include <netinet/ip_var.h>
75 #endif
76
77 #ifdef INET6
78 #include <netinet/ip6.h>
79 #include <netinet6/in6_var.h>
80 #include <netinet6/ip6_var.h>
81 #include <netinet6/scope6_var.h>
82 #endif
83
84 #include <netinet/ip_encap.h>
85 #include <net/bpf.h>
86 #include <net/if_gre.h>
87
88 #include <machine/in_cksum.h>
89 #include <security/mac/mac_framework.h>
90
91 #define GREMTU 1476
92 static const char grename[] = "gre";
93 static MALLOC_DEFINE(M_GRE, grename, "Generic Routing Encapsulation");
94 static VNET_DEFINE(struct mtx, gre_mtx);
95 #define V_gre_mtx VNET(gre_mtx)
96 #define GRE_LIST_LOCK_INIT(x) mtx_init(&V_gre_mtx, "gre_mtx", NULL, \
97 MTX_DEF)
98 #define GRE_LIST_LOCK_DESTROY(x) mtx_destroy(&V_gre_mtx)
99 #define GRE_LIST_LOCK(x) mtx_lock(&V_gre_mtx)
100 #define GRE_LIST_UNLOCK(x) mtx_unlock(&V_gre_mtx)
101
102 static VNET_DEFINE(LIST_HEAD(, gre_softc), gre_softc_list);
103 #define V_gre_softc_list VNET(gre_softc_list)
104 static struct sx gre_ioctl_sx;
105 SX_SYSINIT(gre_ioctl_sx, &gre_ioctl_sx, "gre_ioctl");
106
107 static int gre_clone_create(struct if_clone *, int, caddr_t);
108 static void gre_clone_destroy(struct ifnet *);
109 static VNET_DEFINE(struct if_clone *, gre_cloner);
110 #define V_gre_cloner VNET(gre_cloner)
111
112 static void gre_qflush(struct ifnet *);
113 static int gre_transmit(struct ifnet *, struct mbuf *);
114 static int gre_ioctl(struct ifnet *, u_long, caddr_t);
115 static int gre_output(struct ifnet *, struct mbuf *,
116 const struct sockaddr *, struct route *);
117
118 static void gre_updatehdr(struct gre_softc *);
119 static int gre_set_tunnel(struct ifnet *, struct sockaddr *,
120 struct sockaddr *);
121 static void gre_delete_tunnel(struct ifnet *);
122
123 SYSCTL_DECL(_net_link);
124 static SYSCTL_NODE(_net_link, IFT_TUNNEL, gre, CTLFLAG_RW, 0,
125 "Generic Routing Encapsulation");
126 #ifndef MAX_GRE_NEST
127 /*
128 * This macro controls the default upper limitation on nesting of gre tunnels.
129 * Since, setting a large value to this macro with a careless configuration
130 * may introduce system crash, we don't allow any nestings by default.
131 * If you need to configure nested gre tunnels, you can define this macro
132 * in your kernel configuration file. However, if you do so, please be
133 * careful to configure the tunnels so that it won't make a loop.
134 */
135 #define MAX_GRE_NEST 1
136 #endif
137
138 static VNET_DEFINE(int, max_gre_nesting) = MAX_GRE_NEST;
139 #define V_max_gre_nesting VNET(max_gre_nesting)
140 SYSCTL_INT(_net_link_gre, OID_AUTO, max_nesting, CTLFLAG_RW | CTLFLAG_VNET,
141 &VNET_NAME(max_gre_nesting), 0, "Max nested tunnels");
142
143 static void
144 vnet_gre_init(const void *unused __unused)
145 {
146 LIST_INIT(&V_gre_softc_list);
147 GRE_LIST_LOCK_INIT();
148 V_gre_cloner = if_clone_simple(grename, gre_clone_create,
149 gre_clone_destroy, 0);
150 }
151 VNET_SYSINIT(vnet_gre_init, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
152 vnet_gre_init, NULL);
153
154 static void
155 vnet_gre_uninit(const void *unused __unused)
156 {
157
158 if_clone_detach(V_gre_cloner);
159 GRE_LIST_LOCK_DESTROY();
160 }
161 VNET_SYSUNINIT(vnet_gre_uninit, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
162 vnet_gre_uninit, NULL);
163
164 static int
165 gre_clone_create(struct if_clone *ifc, int unit, caddr_t params)
166 {
167 struct gre_softc *sc;
168
169 sc = malloc(sizeof(struct gre_softc), M_GRE, M_WAITOK | M_ZERO);
170 sc->gre_fibnum = curthread->td_proc->p_fibnum;
171 GRE2IFP(sc) = if_alloc(IFT_TUNNEL);
172 GRE_LOCK_INIT(sc);
173 GRE2IFP(sc)->if_softc = sc;
174 if_initname(GRE2IFP(sc), grename, unit);
175
176 GRE2IFP(sc)->if_mtu = GREMTU;
177 GRE2IFP(sc)->if_flags = IFF_POINTOPOINT|IFF_MULTICAST;
178 GRE2IFP(sc)->if_output = gre_output;
179 GRE2IFP(sc)->if_ioctl = gre_ioctl;
180 GRE2IFP(sc)->if_transmit = gre_transmit;
181 GRE2IFP(sc)->if_qflush = gre_qflush;
182 GRE2IFP(sc)->if_capabilities |= IFCAP_LINKSTATE;
183 GRE2IFP(sc)->if_capenable |= IFCAP_LINKSTATE;
184 if_attach(GRE2IFP(sc));
185 bpfattach(GRE2IFP(sc), DLT_NULL, sizeof(u_int32_t));
186 GRE_LIST_LOCK();
187 LIST_INSERT_HEAD(&V_gre_softc_list, sc, gre_list);
188 GRE_LIST_UNLOCK();
189 return (0);
190 }
191
192 static void
193 gre_clone_destroy(struct ifnet *ifp)
194 {
195 struct gre_softc *sc;
196
197 sx_xlock(&gre_ioctl_sx);
198 sc = ifp->if_softc;
199 gre_delete_tunnel(ifp);
200 GRE_LIST_LOCK();
201 LIST_REMOVE(sc, gre_list);
202 GRE_LIST_UNLOCK();
203 bpfdetach(ifp);
204 if_detach(ifp);
205 ifp->if_softc = NULL;
206 sx_xunlock(&gre_ioctl_sx);
207
208 if_free(ifp);
209 GRE_LOCK_DESTROY(sc);
210 free(sc, M_GRE);
211 }
212
213 static int
214 gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
215 {
216 GRE_RLOCK_TRACKER;
217 struct ifreq *ifr = (struct ifreq *)data;
218 struct sockaddr *src, *dst;
219 struct gre_softc *sc;
220 #ifdef INET
221 struct sockaddr_in *sin = NULL;
222 #endif
223 #ifdef INET6
224 struct sockaddr_in6 *sin6 = NULL;
225 #endif
226 uint32_t opt;
227 int error;
228
229 switch (cmd) {
230 case SIOCSIFMTU:
231 /* XXX: */
232 if (ifr->ifr_mtu < 576)
233 return (EINVAL);
234 ifp->if_mtu = ifr->ifr_mtu;
235 return (0);
236 case SIOCSIFADDR:
237 ifp->if_flags |= IFF_UP;
238 case SIOCSIFFLAGS:
239 case SIOCADDMULTI:
240 case SIOCDELMULTI:
241 return (0);
242 case GRESADDRS:
243 case GRESADDRD:
244 case GREGADDRS:
245 case GREGADDRD:
246 case GRESPROTO:
247 case GREGPROTO:
248 return (EOPNOTSUPP);
249 }
250 src = dst = NULL;
251 sx_xlock(&gre_ioctl_sx);
252 sc = ifp->if_softc;
253 if (sc == NULL) {
254 error = ENXIO;
255 goto end;
256 }
257 error = 0;
258 switch (cmd) {
259 case SIOCSIFPHYADDR:
260 #ifdef INET6
261 case SIOCSIFPHYADDR_IN6:
262 #endif
263 error = EINVAL;
264 switch (cmd) {
265 #ifdef INET
266 case SIOCSIFPHYADDR:
267 src = (struct sockaddr *)
268 &(((struct in_aliasreq *)data)->ifra_addr);
269 dst = (struct sockaddr *)
270 &(((struct in_aliasreq *)data)->ifra_dstaddr);
271 break;
272 #endif
273 #ifdef INET6
274 case SIOCSIFPHYADDR_IN6:
275 src = (struct sockaddr *)
276 &(((struct in6_aliasreq *)data)->ifra_addr);
277 dst = (struct sockaddr *)
278 &(((struct in6_aliasreq *)data)->ifra_dstaddr);
279 break;
280 #endif
281 default:
282 error = EAFNOSUPPORT;
283 goto end;
284 }
285 /* sa_family must be equal */
286 if (src->sa_family != dst->sa_family ||
287 src->sa_len != dst->sa_len)
288 goto end;
289
290 /* validate sa_len */
291 switch (src->sa_family) {
292 #ifdef INET
293 case AF_INET:
294 if (src->sa_len != sizeof(struct sockaddr_in))
295 goto end;
296 break;
297 #endif
298 #ifdef INET6
299 case AF_INET6:
300 if (src->sa_len != sizeof(struct sockaddr_in6))
301 goto end;
302 break;
303 #endif
304 default:
305 error = EAFNOSUPPORT;
306 goto end;
307 }
308 /* check sa_family looks sane for the cmd */
309 error = EAFNOSUPPORT;
310 switch (cmd) {
311 #ifdef INET
312 case SIOCSIFPHYADDR:
313 if (src->sa_family == AF_INET)
314 break;
315 goto end;
316 #endif
317 #ifdef INET6
318 case SIOCSIFPHYADDR_IN6:
319 if (src->sa_family == AF_INET6)
320 break;
321 goto end;
322 #endif
323 }
324 error = EADDRNOTAVAIL;
325 switch (src->sa_family) {
326 #ifdef INET
327 case AF_INET:
328 if (satosin(src)->sin_addr.s_addr == INADDR_ANY ||
329 satosin(dst)->sin_addr.s_addr == INADDR_ANY)
330 goto end;
331 break;
332 #endif
333 #ifdef INET6
334 case AF_INET6:
335 if (IN6_IS_ADDR_UNSPECIFIED(&satosin6(src)->sin6_addr)
336 ||
337 IN6_IS_ADDR_UNSPECIFIED(&satosin6(dst)->sin6_addr))
338 goto end;
339 /*
340 * Check validity of the scope zone ID of the
341 * addresses, and convert it into the kernel
342 * internal form if necessary.
343 */
344 error = sa6_embedscope(satosin6(src), 0);
345 if (error != 0)
346 goto end;
347 error = sa6_embedscope(satosin6(dst), 0);
348 if (error != 0)
349 goto end;
350 #endif
351 }
352 error = gre_set_tunnel(ifp, src, dst);
353 break;
354 case SIOCDIFPHYADDR:
355 gre_delete_tunnel(ifp);
356 break;
357 case SIOCGIFPSRCADDR:
358 case SIOCGIFPDSTADDR:
359 #ifdef INET6
360 case SIOCGIFPSRCADDR_IN6:
361 case SIOCGIFPDSTADDR_IN6:
362 #endif
363 if (sc->gre_family == 0) {
364 error = EADDRNOTAVAIL;
365 break;
366 }
367 GRE_RLOCK(sc);
368 switch (cmd) {
369 #ifdef INET
370 case SIOCGIFPSRCADDR:
371 case SIOCGIFPDSTADDR:
372 if (sc->gre_family != AF_INET) {
373 error = EADDRNOTAVAIL;
374 break;
375 }
376 sin = (struct sockaddr_in *)&ifr->ifr_addr;
377 memset(sin, 0, sizeof(*sin));
378 sin->sin_family = AF_INET;
379 sin->sin_len = sizeof(*sin);
380 break;
381 #endif
382 #ifdef INET6
383 case SIOCGIFPSRCADDR_IN6:
384 case SIOCGIFPDSTADDR_IN6:
385 if (sc->gre_family != AF_INET6) {
386 error = EADDRNOTAVAIL;
387 break;
388 }
389 sin6 = (struct sockaddr_in6 *)
390 &(((struct in6_ifreq *)data)->ifr_addr);
391 memset(sin6, 0, sizeof(*sin6));
392 sin6->sin6_family = AF_INET6;
393 sin6->sin6_len = sizeof(*sin6);
394 break;
395 #endif
396 }
397 if (error == 0) {
398 switch (cmd) {
399 #ifdef INET
400 case SIOCGIFPSRCADDR:
401 sin->sin_addr = sc->gre_oip.ip_src;
402 break;
403 case SIOCGIFPDSTADDR:
404 sin->sin_addr = sc->gre_oip.ip_dst;
405 break;
406 #endif
407 #ifdef INET6
408 case SIOCGIFPSRCADDR_IN6:
409 sin6->sin6_addr = sc->gre_oip6.ip6_src;
410 break;
411 case SIOCGIFPDSTADDR_IN6:
412 sin6->sin6_addr = sc->gre_oip6.ip6_dst;
413 break;
414 #endif
415 }
416 }
417 GRE_RUNLOCK(sc);
418 if (error != 0)
419 break;
420 switch (cmd) {
421 #ifdef INET
422 case SIOCGIFPSRCADDR:
423 case SIOCGIFPDSTADDR:
424 error = prison_if(curthread->td_ucred,
425 (struct sockaddr *)sin);
426 if (error != 0)
427 memset(sin, 0, sizeof(*sin));
428 break;
429 #endif
430 #ifdef INET6
431 case SIOCGIFPSRCADDR_IN6:
432 case SIOCGIFPDSTADDR_IN6:
433 error = prison_if(curthread->td_ucred,
434 (struct sockaddr *)sin6);
435 if (error == 0)
436 error = sa6_recoverscope(sin6);
437 if (error != 0)
438 memset(sin6, 0, sizeof(*sin6));
439 #endif
440 }
441 break;
442 case SIOCGTUNFIB:
443 ifr->ifr_fib = sc->gre_fibnum;
444 break;
445 case SIOCSTUNFIB:
446 if ((error = priv_check(curthread, PRIV_NET_GRE)) != 0)
447 break;
448 if (ifr->ifr_fib >= rt_numfibs)
449 error = EINVAL;
450 else
451 sc->gre_fibnum = ifr->ifr_fib;
452 break;
453 case GRESKEY:
454 if ((error = priv_check(curthread, PRIV_NET_GRE)) != 0)
455 break;
456 if ((error = copyin(ifr_data_get_ptr(ifr), &opt,
457 sizeof(opt))) != 0)
458 break;
459 if (sc->gre_key != opt) {
460 GRE_WLOCK(sc);
461 sc->gre_key = opt;
462 gre_updatehdr(sc);
463 GRE_WUNLOCK(sc);
464 }
465 break;
466 case GREGKEY:
467 error = copyout(&sc->gre_key, ifr_data_get_ptr(ifr),
468 sizeof(sc->gre_key));
469 break;
470 case GRESOPTS:
471 if ((error = priv_check(curthread, PRIV_NET_GRE)) != 0)
472 break;
473 if ((error = copyin(ifr_data_get_ptr(ifr), &opt,
474 sizeof(opt))) != 0)
475 break;
476 if (opt & ~GRE_OPTMASK)
477 error = EINVAL;
478 else {
479 if (sc->gre_options != opt) {
480 GRE_WLOCK(sc);
481 sc->gre_options = opt;
482 gre_updatehdr(sc);
483 GRE_WUNLOCK(sc);
484 }
485 }
486 break;
487
488 case GREGOPTS:
489 error = copyout(&sc->gre_options, ifr_data_get_ptr(ifr),
490 sizeof(sc->gre_options));
491 break;
492 default:
493 error = EINVAL;
494 break;
495 }
496 end:
497 sx_xunlock(&gre_ioctl_sx);
498 return (error);
499 }
500
501 static void
502 gre_updatehdr(struct gre_softc *sc)
503 {
504 struct grehdr *gh = NULL;
505 uint32_t *opts;
506 uint16_t flags;
507
508 GRE_WLOCK_ASSERT(sc);
509 switch (sc->gre_family) {
510 #ifdef INET
511 case AF_INET:
512 sc->gre_hlen = sizeof(struct greip);
513 sc->gre_oip.ip_v = IPPROTO_IPV4;
514 sc->gre_oip.ip_hl = sizeof(struct ip) >> 2;
515 sc->gre_oip.ip_p = IPPROTO_GRE;
516 gh = &sc->gre_gihdr->gi_gre;
517 break;
518 #endif
519 #ifdef INET6
520 case AF_INET6:
521 sc->gre_hlen = sizeof(struct greip6);
522 sc->gre_oip6.ip6_vfc = IPV6_VERSION;
523 sc->gre_oip6.ip6_nxt = IPPROTO_GRE;
524 gh = &sc->gre_gi6hdr->gi6_gre;
525 break;
526 #endif
527 default:
528 return;
529 }
530 flags = 0;
531 opts = gh->gre_opts;
532 if (sc->gre_options & GRE_ENABLE_CSUM) {
533 flags |= GRE_FLAGS_CP;
534 sc->gre_hlen += 2 * sizeof(uint16_t);
535 *opts++ = 0;
536 }
537 if (sc->gre_key != 0) {
538 flags |= GRE_FLAGS_KP;
539 sc->gre_hlen += sizeof(uint32_t);
540 *opts++ = htonl(sc->gre_key);
541 }
542 if (sc->gre_options & GRE_ENABLE_SEQ) {
543 flags |= GRE_FLAGS_SP;
544 sc->gre_hlen += sizeof(uint32_t);
545 *opts++ = 0;
546 } else
547 sc->gre_oseq = 0;
548 gh->gre_flags = htons(flags);
549 }
550
551 static void
552 gre_detach(struct gre_softc *sc)
553 {
554
555 sx_assert(&gre_ioctl_sx, SA_XLOCKED);
556 if (sc->gre_ecookie != NULL)
557 encap_detach(sc->gre_ecookie);
558 sc->gre_ecookie = NULL;
559 }
560
561 static int
562 gre_set_tunnel(struct ifnet *ifp, struct sockaddr *src,
563 struct sockaddr *dst)
564 {
565 struct gre_softc *sc, *tsc;
566 #ifdef INET6
567 struct ip6_hdr *ip6;
568 #endif
569 #ifdef INET
570 struct ip *ip;
571 #endif
572 void *hdr;
573 int error;
574
575 sx_assert(&gre_ioctl_sx, SA_XLOCKED);
576 GRE_LIST_LOCK();
577 sc = ifp->if_softc;
578 LIST_FOREACH(tsc, &V_gre_softc_list, gre_list) {
579 if (tsc == sc || tsc->gre_family != src->sa_family)
580 continue;
581 #ifdef INET
582 if (tsc->gre_family == AF_INET &&
583 tsc->gre_oip.ip_src.s_addr ==
584 satosin(src)->sin_addr.s_addr &&
585 tsc->gre_oip.ip_dst.s_addr ==
586 satosin(dst)->sin_addr.s_addr) {
587 GRE_LIST_UNLOCK();
588 return (EADDRNOTAVAIL);
589 }
590 #endif
591 #ifdef INET6
592 if (tsc->gre_family == AF_INET6 &&
593 IN6_ARE_ADDR_EQUAL(&tsc->gre_oip6.ip6_src,
594 &satosin6(src)->sin6_addr) &&
595 IN6_ARE_ADDR_EQUAL(&tsc->gre_oip6.ip6_dst,
596 &satosin6(dst)->sin6_addr)) {
597 GRE_LIST_UNLOCK();
598 return (EADDRNOTAVAIL);
599 }
600 #endif
601 }
602 GRE_LIST_UNLOCK();
603
604 switch (src->sa_family) {
605 #ifdef INET
606 case AF_INET:
607 hdr = ip = malloc(sizeof(struct greip) +
608 3 * sizeof(uint32_t), M_GRE, M_WAITOK | M_ZERO);
609 ip->ip_src = satosin(src)->sin_addr;
610 ip->ip_dst = satosin(dst)->sin_addr;
611 break;
612 #endif
613 #ifdef INET6
614 case AF_INET6:
615 hdr = ip6 = malloc(sizeof(struct greip6) +
616 3 * sizeof(uint32_t), M_GRE, M_WAITOK | M_ZERO);
617 ip6->ip6_src = satosin6(src)->sin6_addr;
618 ip6->ip6_dst = satosin6(dst)->sin6_addr;
619 break;
620 #endif
621 default:
622 return (EAFNOSUPPORT);
623 }
624 if (sc->gre_family != 0)
625 gre_detach(sc);
626 GRE_WLOCK(sc);
627 if (sc->gre_family != 0)
628 free(sc->gre_hdr, M_GRE);
629 sc->gre_family = src->sa_family;
630 sc->gre_hdr = hdr;
631 sc->gre_oseq = 0;
632 sc->gre_iseq = UINT32_MAX;
633 gre_updatehdr(sc);
634 GRE_WUNLOCK(sc);
635
636 error = 0;
637 switch (src->sa_family) {
638 #ifdef INET
639 case AF_INET:
640 error = in_gre_attach(sc);
641 break;
642 #endif
643 #ifdef INET6
644 case AF_INET6:
645 error = in6_gre_attach(sc);
646 break;
647 #endif
648 }
649 if (error == 0) {
650 ifp->if_drv_flags |= IFF_DRV_RUNNING;
651 if_link_state_change(ifp, LINK_STATE_UP);
652 }
653 return (error);
654 }
655
656 static void
657 gre_delete_tunnel(struct ifnet *ifp)
658 {
659 struct gre_softc *sc = ifp->if_softc;
660 int family;
661
662 GRE_WLOCK(sc);
663 family = sc->gre_family;
664 sc->gre_family = 0;
665 GRE_WUNLOCK(sc);
666 if (family != 0) {
667 gre_detach(sc);
668 free(sc->gre_hdr, M_GRE);
669 }
670 ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
671 if_link_state_change(ifp, LINK_STATE_DOWN);
672 }
673
674 int
675 gre_input(struct mbuf **mp, int *offp, int proto)
676 {
677 struct gre_softc *sc;
678 struct grehdr *gh;
679 struct ifnet *ifp;
680 struct mbuf *m;
681 uint32_t *opts;
682 #ifdef notyet
683 uint32_t key;
684 #endif
685 uint16_t flags;
686 int hlen, isr, af;
687
688 m = *mp;
689 sc = encap_getarg(m);
690 KASSERT(sc != NULL, ("encap_getarg returned NULL"));
691
692 ifp = GRE2IFP(sc);
693 hlen = *offp + sizeof(struct grehdr) + 4 * sizeof(uint32_t);
694 if (m->m_pkthdr.len < hlen)
695 goto drop;
696 if (m->m_len < hlen) {
697 m = m_pullup(m, hlen);
698 if (m == NULL)
699 goto drop;
700 }
701 gh = (struct grehdr *)mtodo(m, *offp);
702 flags = ntohs(gh->gre_flags);
703 if (flags & ~GRE_FLAGS_MASK)
704 goto drop;
705 opts = gh->gre_opts;
706 hlen = 2 * sizeof(uint16_t);
707 if (flags & GRE_FLAGS_CP) {
708 /* reserved1 field must be zero */
709 if (((uint16_t *)opts)[1] != 0)
710 goto drop;
711 if (in_cksum_skip(m, m->m_pkthdr.len, *offp) != 0)
712 goto drop;
713 hlen += 2 * sizeof(uint16_t);
714 opts++;
715 }
716 if (flags & GRE_FLAGS_KP) {
717 #ifdef notyet
718 /*
719 * XXX: The current implementation uses the key only for outgoing
720 * packets. But we can check the key value here, or even in the
721 * encapcheck function.
722 */
723 key = ntohl(*opts);
724 #endif
725 hlen += sizeof(uint32_t);
726 opts++;
727 }
728 #ifdef notyet
729 } else
730 key = 0;
731
732 if (sc->gre_key != 0 && (key != sc->gre_key || key != 0))
733 goto drop;
734 #endif
735 if (flags & GRE_FLAGS_SP) {
736 #ifdef notyet
737 seq = ntohl(*opts);
738 #endif
739 hlen += sizeof(uint32_t);
740 }
741 switch (ntohs(gh->gre_proto)) {
742 case ETHERTYPE_WCCP:
743 /*
744 * For WCCP skip an additional 4 bytes if after GRE header
745 * doesn't follow an IP header.
746 */
747 if (flags == 0 && (*(uint8_t *)gh->gre_opts & 0xF0) != 0x40)
748 hlen += sizeof(uint32_t);
749 /* FALLTHROUGH */
750 case ETHERTYPE_IP:
751 isr = NETISR_IP;
752 af = AF_INET;
753 break;
754 case ETHERTYPE_IPV6:
755 isr = NETISR_IPV6;
756 af = AF_INET6;
757 break;
758 default:
759 goto drop;
760 }
761 m_adj(m, *offp + hlen);
762 m_clrprotoflags(m);
763 m->m_pkthdr.rcvif = ifp;
764 M_SETFIB(m, ifp->if_fib);
765 #ifdef MAC
766 mac_ifnet_create_mbuf(ifp, m);
767 #endif
768 BPF_MTAP2(ifp, &af, sizeof(af), m);
769 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
770 if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
771 if ((ifp->if_flags & IFF_MONITOR) != 0)
772 m_freem(m);
773 else
774 netisr_dispatch(isr, m);
775 return (IPPROTO_DONE);
776 drop:
777 if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
778 m_freem(m);
779 return (IPPROTO_DONE);
780 }
781
782 #define MTAG_GRE 1307983903
783 static int
784 gre_check_nesting(struct ifnet *ifp, struct mbuf *m)
785 {
786 struct m_tag *mtag;
787 int count;
788
789 count = 1;
790 mtag = NULL;
791 while ((mtag = m_tag_locate(m, MTAG_GRE, 0, mtag)) != NULL) {
792 if (*(struct ifnet **)(mtag + 1) == ifp) {
793 log(LOG_NOTICE, "%s: loop detected\n", ifp->if_xname);
794 return (EIO);
795 }
796 count++;
797 }
798 if (count > V_max_gre_nesting) {
799 log(LOG_NOTICE,
800 "%s: if_output recursively called too many times(%d)\n",
801 ifp->if_xname, count);
802 return (EIO);
803 }
804 mtag = m_tag_alloc(MTAG_GRE, 0, sizeof(struct ifnet *), M_NOWAIT);
805 if (mtag == NULL)
806 return (ENOMEM);
807 *(struct ifnet **)(mtag + 1) = ifp;
808 m_tag_prepend(m, mtag);
809 return (0);
810 }
811
812 static int
813 gre_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
814 struct route *ro)
815 {
816 uint32_t af;
817 int error;
818
819 #ifdef MAC
820 error = mac_ifnet_check_transmit(ifp, m);
821 if (error != 0)
822 goto drop;
823 #endif
824 if ((ifp->if_flags & IFF_MONITOR) != 0 ||
825 (ifp->if_flags & IFF_UP) == 0) {
826 error = ENETDOWN;
827 goto drop;
828 }
829
830 error = gre_check_nesting(ifp, m);
831 if (error != 0)
832 goto drop;
833
834 m->m_flags &= ~(M_BCAST|M_MCAST);
835 if (dst->sa_family == AF_UNSPEC)
836 bcopy(dst->sa_data, &af, sizeof(af));
837 else
838 af = dst->sa_family;
839 BPF_MTAP2(ifp, &af, sizeof(af), m);
840 m->m_pkthdr.csum_data = af; /* save af for if_transmit */
841 return (ifp->if_transmit(ifp, m));
842 drop:
843 m_freem(m);
844 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
845 return (error);
846 }
847
848 static void
849 gre_setseqn(struct grehdr *gh, uint32_t seq)
850 {
851 uint32_t *opts;
852 uint16_t flags;
853
854 opts = gh->gre_opts;
855 flags = ntohs(gh->gre_flags);
856 KASSERT((flags & GRE_FLAGS_SP) != 0,
857 ("gre_setseqn called, but GRE_FLAGS_SP isn't set "));
858 if (flags & GRE_FLAGS_CP)
859 opts++;
860 if (flags & GRE_FLAGS_KP)
861 opts++;
862 *opts = htonl(seq);
863 }
864
865 static int
866 gre_transmit(struct ifnet *ifp, struct mbuf *m)
867 {
868 GRE_RLOCK_TRACKER;
869 struct gre_softc *sc;
870 struct grehdr *gh;
871 uint32_t iaf, oaf, oseq;
872 int error, hlen, olen, plen;
873 int want_seq, want_csum;
874
875 plen = 0;
876 sc = ifp->if_softc;
877 if (sc == NULL) {
878 error = ENETDOWN;
879 m_freem(m);
880 goto drop;
881 }
882 GRE_RLOCK(sc);
883 if (sc->gre_family == 0) {
884 GRE_RUNLOCK(sc);
885 error = ENETDOWN;
886 m_freem(m);
887 goto drop;
888 }
889 iaf = m->m_pkthdr.csum_data;
890 oaf = sc->gre_family;
891 hlen = sc->gre_hlen;
892 want_seq = (sc->gre_options & GRE_ENABLE_SEQ) != 0;
893 if (want_seq)
894 oseq = sc->gre_oseq++; /* XXX */
895 else
896 oseq = 0; /* Make compiler happy. */
897 want_csum = (sc->gre_options & GRE_ENABLE_CSUM) != 0;
898 M_SETFIB(m, sc->gre_fibnum);
899 M_PREPEND(m, hlen, M_NOWAIT);
900 if (m == NULL) {
901 GRE_RUNLOCK(sc);
902 error = ENOBUFS;
903 goto drop;
904 }
905 bcopy(sc->gre_hdr, mtod(m, void *), hlen);
906 GRE_RUNLOCK(sc);
907 switch (oaf) {
908 #ifdef INET
909 case AF_INET:
910 olen = sizeof(struct ip);
911 break;
912 #endif
913 #ifdef INET6
914 case AF_INET6:
915 olen = sizeof(struct ip6_hdr);
916 break;
917 #endif
918 default:
919 error = ENETDOWN;
920 goto drop;
921 }
922 gh = (struct grehdr *)mtodo(m, olen);
923 switch (iaf) {
924 #ifdef INET
925 case AF_INET:
926 gh->gre_proto = htons(ETHERTYPE_IP);
927 break;
928 #endif
929 #ifdef INET6
930 case AF_INET6:
931 gh->gre_proto = htons(ETHERTYPE_IPV6);
932 break;
933 #endif
934 default:
935 error = ENETDOWN;
936 goto drop;
937 }
938 if (want_seq)
939 gre_setseqn(gh, oseq);
940 if (want_csum) {
941 *(uint16_t *)gh->gre_opts = in_cksum_skip(m,
942 m->m_pkthdr.len, olen);
943 }
944 plen = m->m_pkthdr.len - hlen;
945 switch (oaf) {
946 #ifdef INET
947 case AF_INET:
948 error = in_gre_output(m, iaf, hlen);
949 break;
950 #endif
951 #ifdef INET6
952 case AF_INET6:
953 error = in6_gre_output(m, iaf, hlen);
954 break;
955 #endif
956 default:
957 m_freem(m);
958 error = ENETDOWN;
959 }
960 drop:
961 if (error)
962 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
963 else {
964 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
965 if_inc_counter(ifp, IFCOUNTER_OBYTES, plen);
966 }
967 return (error);
968 }
969
970 static void
971 gre_qflush(struct ifnet *ifp __unused)
972 {
973
974 }
975
976 static int
977 gremodevent(module_t mod, int type, void *data)
978 {
979
980 switch (type) {
981 case MOD_LOAD:
982 case MOD_UNLOAD:
983 break;
984 default:
985 return (EOPNOTSUPP);
986 }
987 return (0);
988 }
989
990 static moduledata_t gre_mod = {
991 "if_gre",
992 gremodevent,
993 0
994 };
995
996 DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
997 MODULE_VERSION(if_gre, 1);
Cache object: cc31fff1702a52cb44a10a3a2e7a4f36
|