FreeBSD/Linux Kernel Cross Reference
sys/net/if_gre.c
1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 1998 The NetBSD Foundation, Inc.
5 * Copyright (c) 2014, 2018 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 "opt_inet.h"
41 #include "opt_inet6.h"
42 #include "opt_rss.h"
43
44 #include <sys/param.h>
45 #include <sys/kernel.h>
46 #include <sys/lock.h>
47 #include <sys/malloc.h>
48 #include <sys/module.h>
49 #include <sys/mbuf.h>
50 #include <sys/priv.h>
51 #include <sys/proc.h>
52 #include <sys/socket.h>
53 #include <sys/socketvar.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_private.h>
64 #include <net/if_clone.h>
65 #include <net/if_types.h>
66 #include <net/netisr.h>
67 #include <net/vnet.h>
68 #include <net/route.h>
69
70 #include <netinet/in.h>
71 #include <netinet/in_pcb.h>
72 #ifdef INET
73 #include <netinet/in_var.h>
74 #include <netinet/ip.h>
75 #include <netinet/ip_var.h>
76 #ifdef RSS
77 #include <netinet/in_rss.h>
78 #endif
79 #endif
80
81 #ifdef INET6
82 #include <netinet/ip6.h>
83 #include <netinet6/in6_var.h>
84 #include <netinet6/ip6_var.h>
85 #ifdef RSS
86 #include <netinet6/in6_rss.h>
87 #endif
88 #endif
89
90 #include <netinet/ip_encap.h>
91 #include <netinet/udp.h>
92 #include <net/bpf.h>
93 #include <net/if_gre.h>
94
95 #include <machine/in_cksum.h>
96 #include <security/mac/mac_framework.h>
97
98 #define GREMTU 1476
99
100 static const char grename[] = "gre";
101 MALLOC_DEFINE(M_GRE, grename, "Generic Routing Encapsulation");
102
103 static struct sx gre_ioctl_sx;
104 SX_SYSINIT(gre_ioctl_sx, &gre_ioctl_sx, "gre_ioctl");
105
106 static int gre_clone_create(struct if_clone *, int, caddr_t);
107 static void gre_clone_destroy(struct ifnet *);
108 VNET_DEFINE_STATIC(struct if_clone *, gre_cloner);
109 #define V_gre_cloner VNET(gre_cloner)
110
111 #ifdef VIMAGE
112 static void gre_reassign(struct ifnet *, struct vnet *, char *);
113 #endif
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 static void gre_delete_tunnel(struct gre_softc *);
120
121 SYSCTL_DECL(_net_link);
122 static SYSCTL_NODE(_net_link, IFT_TUNNEL, gre, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
123 "Generic Routing Encapsulation");
124 #ifndef MAX_GRE_NEST
125 /*
126 * This macro controls the default upper limitation on nesting of gre tunnels.
127 * Since, setting a large value to this macro with a careless configuration
128 * may introduce system crash, we don't allow any nestings by default.
129 * If you need to configure nested gre tunnels, you can define this macro
130 * in your kernel configuration file. However, if you do so, please be
131 * careful to configure the tunnels so that it won't make a loop.
132 */
133 #define MAX_GRE_NEST 1
134 #endif
135
136 VNET_DEFINE_STATIC(int, max_gre_nesting) = MAX_GRE_NEST;
137 #define V_max_gre_nesting VNET(max_gre_nesting)
138 SYSCTL_INT(_net_link_gre, OID_AUTO, max_nesting, CTLFLAG_RW | CTLFLAG_VNET,
139 &VNET_NAME(max_gre_nesting), 0, "Max nested tunnels");
140
141 static void
142 vnet_gre_init(const void *unused __unused)
143 {
144
145 V_gre_cloner = if_clone_simple(grename, gre_clone_create,
146 gre_clone_destroy, 0);
147 #ifdef INET
148 in_gre_init();
149 #endif
150 #ifdef INET6
151 in6_gre_init();
152 #endif
153 }
154 VNET_SYSINIT(vnet_gre_init, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
155 vnet_gre_init, NULL);
156
157 static void
158 vnet_gre_uninit(const void *unused __unused)
159 {
160
161 if_clone_detach(V_gre_cloner);
162 #ifdef INET
163 in_gre_uninit();
164 #endif
165 #ifdef INET6
166 in6_gre_uninit();
167 #endif
168 /* XXX: epoch_call drain */
169 }
170 VNET_SYSUNINIT(vnet_gre_uninit, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
171 vnet_gre_uninit, NULL);
172
173 static int
174 gre_clone_create(struct if_clone *ifc, int unit, caddr_t params)
175 {
176 struct gre_softc *sc;
177
178 sc = malloc(sizeof(struct gre_softc), M_GRE, M_WAITOK | M_ZERO);
179 sc->gre_fibnum = curthread->td_proc->p_fibnum;
180 GRE2IFP(sc) = if_alloc(IFT_TUNNEL);
181 GRE2IFP(sc)->if_softc = sc;
182 if_initname(GRE2IFP(sc), grename, unit);
183
184 GRE2IFP(sc)->if_mtu = GREMTU;
185 GRE2IFP(sc)->if_flags = IFF_POINTOPOINT|IFF_MULTICAST;
186 GRE2IFP(sc)->if_output = gre_output;
187 GRE2IFP(sc)->if_ioctl = gre_ioctl;
188 GRE2IFP(sc)->if_transmit = gre_transmit;
189 GRE2IFP(sc)->if_qflush = gre_qflush;
190 #ifdef VIMAGE
191 GRE2IFP(sc)->if_reassign = gre_reassign;
192 #endif
193 GRE2IFP(sc)->if_capabilities |= IFCAP_LINKSTATE;
194 GRE2IFP(sc)->if_capenable |= IFCAP_LINKSTATE;
195 if_attach(GRE2IFP(sc));
196 bpfattach(GRE2IFP(sc), DLT_NULL, sizeof(u_int32_t));
197 return (0);
198 }
199
200 #ifdef VIMAGE
201 static void
202 gre_reassign(struct ifnet *ifp, struct vnet *new_vnet __unused,
203 char *unused __unused)
204 {
205 struct gre_softc *sc;
206
207 sx_xlock(&gre_ioctl_sx);
208 sc = ifp->if_softc;
209 if (sc != NULL)
210 gre_delete_tunnel(sc);
211 sx_xunlock(&gre_ioctl_sx);
212 }
213 #endif /* VIMAGE */
214
215 static void
216 gre_clone_destroy(struct ifnet *ifp)
217 {
218 struct gre_softc *sc;
219
220 sx_xlock(&gre_ioctl_sx);
221 sc = ifp->if_softc;
222 gre_delete_tunnel(sc);
223 bpfdetach(ifp);
224 if_detach(ifp);
225 ifp->if_softc = NULL;
226 sx_xunlock(&gre_ioctl_sx);
227
228 GRE_WAIT();
229 if_free(ifp);
230 free(sc, M_GRE);
231 }
232
233 static int
234 gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
235 {
236 struct ifreq *ifr = (struct ifreq *)data;
237 struct gre_softc *sc;
238 uint32_t opt;
239 int error;
240
241 switch (cmd) {
242 case SIOCSIFMTU:
243 /* XXX: */
244 if (ifr->ifr_mtu < 576)
245 return (EINVAL);
246 ifp->if_mtu = ifr->ifr_mtu;
247 return (0);
248 case SIOCSIFADDR:
249 ifp->if_flags |= IFF_UP;
250 case SIOCSIFFLAGS:
251 case SIOCADDMULTI:
252 case SIOCDELMULTI:
253 return (0);
254 case GRESADDRS:
255 case GRESADDRD:
256 case GREGADDRS:
257 case GREGADDRD:
258 case GRESPROTO:
259 case GREGPROTO:
260 return (EOPNOTSUPP);
261 }
262 sx_xlock(&gre_ioctl_sx);
263 sc = ifp->if_softc;
264 if (sc == NULL) {
265 error = ENXIO;
266 goto end;
267 }
268 error = 0;
269 switch (cmd) {
270 case SIOCDIFPHYADDR:
271 if (sc->gre_family == 0)
272 break;
273 gre_delete_tunnel(sc);
274 break;
275 #ifdef INET
276 case SIOCSIFPHYADDR:
277 case SIOCGIFPSRCADDR:
278 case SIOCGIFPDSTADDR:
279 error = in_gre_ioctl(sc, cmd, data);
280 break;
281 #endif
282 #ifdef INET6
283 case SIOCSIFPHYADDR_IN6:
284 case SIOCGIFPSRCADDR_IN6:
285 case SIOCGIFPDSTADDR_IN6:
286 error = in6_gre_ioctl(sc, cmd, data);
287 break;
288 #endif
289 case SIOCGTUNFIB:
290 ifr->ifr_fib = sc->gre_fibnum;
291 break;
292 case SIOCSTUNFIB:
293 if ((error = priv_check(curthread, PRIV_NET_GRE)) != 0)
294 break;
295 if (ifr->ifr_fib >= rt_numfibs)
296 error = EINVAL;
297 else
298 sc->gre_fibnum = ifr->ifr_fib;
299 break;
300 case GRESKEY:
301 case GRESOPTS:
302 case GRESPORT:
303 if ((error = priv_check(curthread, PRIV_NET_GRE)) != 0)
304 break;
305 if ((error = copyin(ifr_data_get_ptr(ifr), &opt,
306 sizeof(opt))) != 0)
307 break;
308 if (cmd == GRESKEY) {
309 if (sc->gre_key == opt)
310 break;
311 } else if (cmd == GRESOPTS) {
312 if (opt & ~GRE_OPTMASK) {
313 error = EINVAL;
314 break;
315 }
316 if (sc->gre_options == opt)
317 break;
318 } else if (cmd == GRESPORT) {
319 if (opt != 0 && (opt < V_ipport_hifirstauto ||
320 opt > V_ipport_hilastauto)) {
321 error = EINVAL;
322 break;
323 }
324 if (sc->gre_port == opt)
325 break;
326 if ((sc->gre_options & GRE_UDPENCAP) == 0) {
327 /*
328 * UDP encapsulation is not enabled, thus
329 * there is no need to reattach softc.
330 */
331 sc->gre_port = opt;
332 break;
333 }
334 }
335 switch (sc->gre_family) {
336 #ifdef INET
337 case AF_INET:
338 error = in_gre_setopts(sc, cmd, opt);
339 break;
340 #endif
341 #ifdef INET6
342 case AF_INET6:
343 error = in6_gre_setopts(sc, cmd, opt);
344 break;
345 #endif
346 default:
347 /*
348 * Tunnel is not yet configured.
349 * We can just change any parameters.
350 */
351 if (cmd == GRESKEY)
352 sc->gre_key = opt;
353 if (cmd == GRESOPTS)
354 sc->gre_options = opt;
355 if (cmd == GRESPORT)
356 sc->gre_port = opt;
357 break;
358 }
359 /*
360 * XXX: Do we need to initiate change of interface
361 * state here?
362 */
363 break;
364 case GREGKEY:
365 error = copyout(&sc->gre_key, ifr_data_get_ptr(ifr),
366 sizeof(sc->gre_key));
367 break;
368 case GREGOPTS:
369 error = copyout(&sc->gre_options, ifr_data_get_ptr(ifr),
370 sizeof(sc->gre_options));
371 break;
372 case GREGPORT:
373 error = copyout(&sc->gre_port, ifr_data_get_ptr(ifr),
374 sizeof(sc->gre_port));
375 break;
376 default:
377 error = EINVAL;
378 break;
379 }
380 if (error == 0 && sc->gre_family != 0) {
381 if (
382 #ifdef INET
383 cmd == SIOCSIFPHYADDR ||
384 #endif
385 #ifdef INET6
386 cmd == SIOCSIFPHYADDR_IN6 ||
387 #endif
388 0) {
389 if_link_state_change(ifp, LINK_STATE_UP);
390 }
391 }
392 end:
393 sx_xunlock(&gre_ioctl_sx);
394 return (error);
395 }
396
397 static void
398 gre_delete_tunnel(struct gre_softc *sc)
399 {
400 struct gre_socket *gs;
401
402 sx_assert(&gre_ioctl_sx, SA_XLOCKED);
403 if (sc->gre_family != 0) {
404 CK_LIST_REMOVE(sc, chain);
405 CK_LIST_REMOVE(sc, srchash);
406 GRE_WAIT();
407 free(sc->gre_hdr, M_GRE);
408 sc->gre_family = 0;
409 }
410 /*
411 * If this Tunnel was the last one that could use UDP socket,
412 * we should unlink socket from hash table and close it.
413 */
414 if ((gs = sc->gre_so) != NULL && CK_LIST_EMPTY(&gs->list)) {
415 CK_LIST_REMOVE(gs, chain);
416 soclose(gs->so);
417 NET_EPOCH_CALL(gre_sofree, &gs->epoch_ctx);
418 sc->gre_so = NULL;
419 }
420 GRE2IFP(sc)->if_drv_flags &= ~IFF_DRV_RUNNING;
421 if_link_state_change(GRE2IFP(sc), LINK_STATE_DOWN);
422 }
423
424 struct gre_list *
425 gre_hashinit(void)
426 {
427 struct gre_list *hash;
428 int i;
429
430 hash = malloc(sizeof(struct gre_list) * GRE_HASH_SIZE,
431 M_GRE, M_WAITOK);
432 for (i = 0; i < GRE_HASH_SIZE; i++)
433 CK_LIST_INIT(&hash[i]);
434
435 return (hash);
436 }
437
438 void
439 gre_hashdestroy(struct gre_list *hash)
440 {
441
442 free(hash, M_GRE);
443 }
444
445 void
446 gre_sofree(epoch_context_t ctx)
447 {
448 struct gre_socket *gs;
449
450 gs = __containerof(ctx, struct gre_socket, epoch_ctx);
451 free(gs, M_GRE);
452 }
453
454 static __inline uint16_t
455 gre_cksum_add(uint16_t sum, uint16_t a)
456 {
457 uint16_t res;
458
459 res = sum + a;
460 return (res + (res < a));
461 }
462
463 void
464 gre_update_udphdr(struct gre_softc *sc, struct udphdr *udp, uint16_t csum)
465 {
466
467 sx_assert(&gre_ioctl_sx, SA_XLOCKED);
468 MPASS(sc->gre_options & GRE_UDPENCAP);
469
470 udp->uh_dport = htons(GRE_UDPPORT);
471 udp->uh_sport = htons(sc->gre_port);
472 udp->uh_sum = csum;
473 udp->uh_ulen = 0;
474 }
475
476 void
477 gre_update_hdr(struct gre_softc *sc, struct grehdr *gh)
478 {
479 uint32_t *opts;
480 uint16_t flags;
481
482 sx_assert(&gre_ioctl_sx, SA_XLOCKED);
483
484 flags = 0;
485 opts = gh->gre_opts;
486 if (sc->gre_options & GRE_ENABLE_CSUM) {
487 flags |= GRE_FLAGS_CP;
488 sc->gre_hlen += 2 * sizeof(uint16_t);
489 *opts++ = 0;
490 }
491 if (sc->gre_key != 0) {
492 flags |= GRE_FLAGS_KP;
493 sc->gre_hlen += sizeof(uint32_t);
494 *opts++ = htonl(sc->gre_key);
495 }
496 if (sc->gre_options & GRE_ENABLE_SEQ) {
497 flags |= GRE_FLAGS_SP;
498 sc->gre_hlen += sizeof(uint32_t);
499 *opts++ = 0;
500 } else
501 sc->gre_oseq = 0;
502 gh->gre_flags = htons(flags);
503 }
504
505 int
506 gre_input(struct mbuf *m, int off, int proto, void *arg)
507 {
508 struct gre_softc *sc = arg;
509 struct grehdr *gh;
510 struct ifnet *ifp;
511 uint32_t *opts;
512 #ifdef notyet
513 uint32_t key;
514 #endif
515 uint16_t flags;
516 int hlen, isr, af;
517
518 ifp = GRE2IFP(sc);
519 hlen = off + sizeof(struct grehdr) + 4 * sizeof(uint32_t);
520 if (m->m_pkthdr.len < hlen)
521 goto drop;
522 if (m->m_len < hlen) {
523 m = m_pullup(m, hlen);
524 if (m == NULL)
525 goto drop;
526 }
527 gh = (struct grehdr *)mtodo(m, off);
528 flags = ntohs(gh->gre_flags);
529 if (flags & ~GRE_FLAGS_MASK)
530 goto drop;
531 opts = gh->gre_opts;
532 hlen = 2 * sizeof(uint16_t);
533 if (flags & GRE_FLAGS_CP) {
534 /* reserved1 field must be zero */
535 if (((uint16_t *)opts)[1] != 0)
536 goto drop;
537 if (in_cksum_skip(m, m->m_pkthdr.len, off) != 0)
538 goto drop;
539 hlen += 2 * sizeof(uint16_t);
540 opts++;
541 }
542 if (flags & GRE_FLAGS_KP) {
543 #ifdef notyet
544 /*
545 * XXX: The current implementation uses the key only for outgoing
546 * packets. But we can check the key value here, or even in the
547 * encapcheck function.
548 */
549 key = ntohl(*opts);
550 #endif
551 hlen += sizeof(uint32_t);
552 opts++;
553 }
554 #ifdef notyet
555 } else
556 key = 0;
557
558 if (sc->gre_key != 0 && (key != sc->gre_key || key != 0))
559 goto drop;
560 #endif
561 if (flags & GRE_FLAGS_SP) {
562 #ifdef notyet
563 seq = ntohl(*opts);
564 #endif
565 hlen += sizeof(uint32_t);
566 }
567 switch (ntohs(gh->gre_proto)) {
568 case ETHERTYPE_WCCP:
569 /*
570 * For WCCP skip an additional 4 bytes if after GRE header
571 * doesn't follow an IP header.
572 */
573 if (flags == 0 && (*(uint8_t *)gh->gre_opts & 0xF0) != 0x40)
574 hlen += sizeof(uint32_t);
575 /* FALLTHROUGH */
576 case ETHERTYPE_IP:
577 isr = NETISR_IP;
578 af = AF_INET;
579 break;
580 case ETHERTYPE_IPV6:
581 isr = NETISR_IPV6;
582 af = AF_INET6;
583 break;
584 default:
585 goto drop;
586 }
587 m_adj(m, off + hlen);
588 m_clrprotoflags(m);
589 m->m_pkthdr.rcvif = ifp;
590 M_SETFIB(m, ifp->if_fib);
591 #ifdef MAC
592 mac_ifnet_create_mbuf(ifp, m);
593 #endif
594 BPF_MTAP2(ifp, &af, sizeof(af), m);
595 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
596 if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
597 if ((ifp->if_flags & IFF_MONITOR) != 0)
598 m_freem(m);
599 else
600 netisr_dispatch(isr, m);
601 return (IPPROTO_DONE);
602 drop:
603 if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
604 m_freem(m);
605 return (IPPROTO_DONE);
606 }
607
608 static int
609 gre_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
610 struct route *ro)
611 {
612 uint32_t af;
613
614 if (dst->sa_family == AF_UNSPEC)
615 bcopy(dst->sa_data, &af, sizeof(af));
616 else
617 af = RO_GET_FAMILY(ro, dst);
618 /*
619 * Now save the af in the inbound pkt csum data, this is a cheat since
620 * we are using the inbound csum_data field to carry the af over to
621 * the gre_transmit() routine, avoiding using yet another mtag.
622 */
623 m->m_pkthdr.csum_data = af;
624 return (ifp->if_transmit(ifp, m));
625 }
626
627 static void
628 gre_setseqn(struct grehdr *gh, uint32_t seq)
629 {
630 uint32_t *opts;
631 uint16_t flags;
632
633 opts = gh->gre_opts;
634 flags = ntohs(gh->gre_flags);
635 KASSERT((flags & GRE_FLAGS_SP) != 0,
636 ("gre_setseqn called, but GRE_FLAGS_SP isn't set "));
637 if (flags & GRE_FLAGS_CP)
638 opts++;
639 if (flags & GRE_FLAGS_KP)
640 opts++;
641 *opts = htonl(seq);
642 }
643
644 static uint32_t
645 gre_flowid(struct gre_softc *sc, struct mbuf *m, uint32_t af)
646 {
647 uint32_t flowid = 0;
648
649 if ((sc->gre_options & GRE_UDPENCAP) == 0 || sc->gre_port != 0)
650 return (flowid);
651 switch (af) {
652 #ifdef INET
653 case AF_INET:
654 #ifdef RSS
655 flowid = rss_hash_ip4_2tuple(mtod(m, struct ip *)->ip_src,
656 mtod(m, struct ip *)->ip_dst);
657 break;
658 #endif
659 flowid = mtod(m, struct ip *)->ip_src.s_addr ^
660 mtod(m, struct ip *)->ip_dst.s_addr;
661 break;
662 #endif
663 #ifdef INET6
664 case AF_INET6:
665 #ifdef RSS
666 flowid = rss_hash_ip6_2tuple(
667 &mtod(m, struct ip6_hdr *)->ip6_src,
668 &mtod(m, struct ip6_hdr *)->ip6_dst);
669 break;
670 #endif
671 flowid = mtod(m, struct ip6_hdr *)->ip6_src.s6_addr32[3] ^
672 mtod(m, struct ip6_hdr *)->ip6_dst.s6_addr32[3];
673 break;
674 #endif
675 default:
676 break;
677 }
678 return (flowid);
679 }
680
681 #define MTAG_GRE 1307983903
682 static int
683 gre_transmit(struct ifnet *ifp, struct mbuf *m)
684 {
685 GRE_RLOCK_TRACKER;
686 struct gre_softc *sc;
687 struct grehdr *gh;
688 struct udphdr *uh;
689 uint32_t af, flowid;
690 int error, len;
691 uint16_t proto;
692
693 len = 0;
694 GRE_RLOCK();
695 #ifdef MAC
696 error = mac_ifnet_check_transmit(ifp, m);
697 if (error) {
698 m_freem(m);
699 goto drop;
700 }
701 #endif
702 error = ENETDOWN;
703 sc = ifp->if_softc;
704 if ((ifp->if_flags & IFF_MONITOR) != 0 ||
705 (ifp->if_flags & IFF_UP) == 0 ||
706 (ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
707 sc->gre_family == 0 ||
708 (error = if_tunnel_check_nesting(ifp, m, MTAG_GRE,
709 V_max_gre_nesting)) != 0) {
710 m_freem(m);
711 goto drop;
712 }
713 af = m->m_pkthdr.csum_data;
714 BPF_MTAP2(ifp, &af, sizeof(af), m);
715 m->m_flags &= ~(M_BCAST|M_MCAST);
716 flowid = gre_flowid(sc, m, af);
717 M_SETFIB(m, sc->gre_fibnum);
718 M_PREPEND(m, sc->gre_hlen, M_NOWAIT);
719 if (m == NULL) {
720 error = ENOBUFS;
721 goto drop;
722 }
723 bcopy(sc->gre_hdr, mtod(m, void *), sc->gre_hlen);
724 /* Determine GRE proto */
725 switch (af) {
726 #ifdef INET
727 case AF_INET:
728 proto = htons(ETHERTYPE_IP);
729 break;
730 #endif
731 #ifdef INET6
732 case AF_INET6:
733 proto = htons(ETHERTYPE_IPV6);
734 break;
735 #endif
736 default:
737 m_freem(m);
738 error = ENETDOWN;
739 goto drop;
740 }
741 /* Determine offset of GRE header */
742 switch (sc->gre_family) {
743 #ifdef INET
744 case AF_INET:
745 len = sizeof(struct ip);
746 break;
747 #endif
748 #ifdef INET6
749 case AF_INET6:
750 len = sizeof(struct ip6_hdr);
751 break;
752 #endif
753 default:
754 m_freem(m);
755 error = ENETDOWN;
756 goto drop;
757 }
758 if (sc->gre_options & GRE_UDPENCAP) {
759 uh = (struct udphdr *)mtodo(m, len);
760 uh->uh_sport |= htons(V_ipport_hifirstauto) |
761 (flowid >> 16) | (flowid & 0xFFFF);
762 uh->uh_sport = htons(ntohs(uh->uh_sport) %
763 V_ipport_hilastauto);
764 uh->uh_ulen = htons(m->m_pkthdr.len - len);
765 uh->uh_sum = gre_cksum_add(uh->uh_sum,
766 htons(m->m_pkthdr.len - len + IPPROTO_UDP));
767 m->m_pkthdr.csum_flags = sc->gre_csumflags;
768 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
769 len += sizeof(struct udphdr);
770 }
771 gh = (struct grehdr *)mtodo(m, len);
772 gh->gre_proto = proto;
773 if (sc->gre_options & GRE_ENABLE_SEQ)
774 gre_setseqn(gh, sc->gre_oseq++);
775 if (sc->gre_options & GRE_ENABLE_CSUM) {
776 *(uint16_t *)gh->gre_opts = in_cksum_skip(m,
777 m->m_pkthdr.len, len);
778 }
779 len = m->m_pkthdr.len - len;
780 switch (sc->gre_family) {
781 #ifdef INET
782 case AF_INET:
783 error = in_gre_output(m, af, sc->gre_hlen);
784 break;
785 #endif
786 #ifdef INET6
787 case AF_INET6:
788 error = in6_gre_output(m, af, sc->gre_hlen, flowid);
789 break;
790 #endif
791 default:
792 m_freem(m);
793 error = ENETDOWN;
794 }
795 drop:
796 if (error)
797 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
798 else {
799 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
800 if_inc_counter(ifp, IFCOUNTER_OBYTES, len);
801 }
802 GRE_RUNLOCK();
803 return (error);
804 }
805
806 static void
807 gre_qflush(struct ifnet *ifp __unused)
808 {
809
810 }
811
812 static int
813 gremodevent(module_t mod, int type, void *data)
814 {
815
816 switch (type) {
817 case MOD_LOAD:
818 case MOD_UNLOAD:
819 break;
820 default:
821 return (EOPNOTSUPP);
822 }
823 return (0);
824 }
825
826 static moduledata_t gre_mod = {
827 "if_gre",
828 gremodevent,
829 0
830 };
831
832 DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
833 MODULE_VERSION(if_gre, 1);
Cache object: 873b7c2b1ed278e6a305dce8e67e537f
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