proc->thread stage 4: rework the VFS and DEVICE subsystems to take thread
[dragonfly.git] / sys / net / gre / if_gre.c
CommitLineData
984263bc
MD
1/* $NetBSD: if_gre.c,v 1.42 2002/08/14 00:23:27 itojun Exp $ */
2/* $FreeBSD: src/sys/net/if_gre.c,v 1.9.2.3 2003/01/23 21:06:44 sam Exp $ */
dadab5e9 3/* $DragonFly: src/sys/net/gre/if_gre.c,v 1.4 2003/06/25 03:56:02 dillon Exp $ */
984263bc
MD
4
5/*
6 * Copyright (c) 1998 The NetBSD Foundation, Inc.
7 * All rights reserved.
8 *
9 * This code is derived from software contributed to The NetBSD Foundation
10 * by Heiko W.Rupp <hwr@pilhuhn.de>
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. All advertising materials mentioning features or use of this software
21 * must display the following acknowledgement:
22 * This product includes software developed by the NetBSD
23 * Foundation, Inc. and its contributors.
24 * 4. Neither the name of The NetBSD Foundation nor the names of its
25 * contributors may be used to endorse or promote products derived
26 * from this software without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
29 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
30 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
31 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
32 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
33 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
34 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
35 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
36 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
37 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
38 * POSSIBILITY OF SUCH DAMAGE.
39 */
40
41/*
42 * Encapsulate L3 protocols into IP
43 * See RFC 1701 and 1702 for more details.
44 * If_gre is compatible with Cisco GRE tunnels, so you can
45 * have a NetBSD box as the other end of a tunnel interface of a Cisco
46 * router. See gre(4) for more details.
47 * Also supported: IP in IP encaps (proto 55) as of RFC 2004
48 */
49
50#include "opt_atalk.h"
51#include "opt_inet.h"
52#include "opt_ns.h"
53
54#include <sys/param.h>
55#include <sys/kernel.h>
56#include <sys/malloc.h>
57#include <sys/mbuf.h>
58#include <sys/proc.h>
59#include <sys/protosw.h>
60#include <machine/bus.h>
61#include <sys/rman.h>
62#include <sys/socket.h>
63#include <sys/sockio.h>
64#include <sys/sysctl.h>
65#include <sys/systm.h>
66
67#include <net/ethernet.h>
68#include <net/if.h>
69#include <net/if_types.h>
70#include <net/route.h>
71
72#ifdef INET
73#include <netinet/in.h>
74#include <netinet/in_systm.h>
75#include <netinet/in_var.h>
76#include <netinet/ip.h>
77#include <netinet/ip_gre.h>
78#include <netinet/ip_var.h>
79#include <netinet/ip_encap.h>
80#else
81#error "Huh? if_gre without inet?"
82#endif
83
84#include <net/bpf.h>
85
86#include <net/net_osdep.h>
87#include <net/if_gre.h>
88
89/*
90 * It is not easy to calculate the right value for a GRE MTU.
91 * We leave this task to the admin and use the same default that
92 * other vendors use.
93 */
94#define GREMTU 1476
95
96#define GRENAME "gre"
97#define GRE_MAXUNIT 0x7fff
98
99static MALLOC_DEFINE(M_GRE, GRENAME, "Generic Routing Encapsulation");
100static struct rman greunits[1];
101
102struct gre_softc_head gre_softc_list;
103
104static int gre_clone_create(struct if_clone *, int *);
105static void gre_clone_destroy(struct ifnet *);
106static int gre_ioctl(struct ifnet *, u_long, caddr_t);
107static int gre_output(struct ifnet *, struct mbuf *, struct sockaddr *,
108 struct rtentry *rt);
109
110static struct if_clone gre_cloner =
111 IF_CLONE_INITIALIZER("gre", gre_clone_create, gre_clone_destroy);
112
113static int gre_compute_route(struct gre_softc *sc);
114
115static void greattach(void);
116
117#ifdef INET
118extern struct domain inetdomain;
119static const struct protosw in_gre_protosw =
120{ SOCK_RAW, &inetdomain, IPPROTO_GRE, PR_ATOMIC|PR_ADDR,
121 gre_input, rip_output, rip_ctlinput, rip_ctloutput,
122 0,
123 0, 0, 0, 0,
124 &rip_usrreqs
125};
126static const struct protosw in_mobile_protosw =
127{ SOCK_RAW, &inetdomain, IPPROTO_MOBILE, PR_ATOMIC|PR_ADDR,
128 gre_mobile_input, rip_output, rip_ctlinput, rip_ctloutput,
129 0,
130 0, 0, 0, 0,
131 &rip_usrreqs
132};
133#endif
134
135SYSCTL_DECL(_net_link);
136SYSCTL_NODE(_net_link, IFT_OTHER, gre, CTLFLAG_RW, 0,
137 "Generic Routing Encapsulation");
138#ifndef MAX_GRE_NEST
139/*
140 * This macro controls the default upper limitation on nesting of gre tunnels.
141 * Since, setting a large value to this macro with a careless configuration
142 * may introduce system crash, we don't allow any nestings by default.
143 * If you need to configure nested gre tunnels, you can define this macro
144 * in your kernel configuration file. However, if you do so, please be
145 * careful to configure the tunnels so that it won't make a loop.
146 */
147#define MAX_GRE_NEST 1
148#endif
149static int max_gre_nesting = MAX_GRE_NEST;
150SYSCTL_INT(_net_link_gre, OID_AUTO, max_nesting, CTLFLAG_RW,
151 &max_gre_nesting, 0, "Max nested tunnels");
152
153/* ARGSUSED */
154static void
155greattach(void)
156{
157
158 LIST_INIT(&gre_softc_list);
159 if_clone_attach(&gre_cloner);
160}
161
162static int
163gre_clone_create(ifc, unit)
164 struct if_clone *ifc;
165 int *unit;
166{
167 struct resource *r;
168 struct gre_softc *sc;
169
170 if (*unit > GRE_MAXUNIT)
171 return (ENXIO);
172
173 if (*unit < 0) {
174 r = rman_reserve_resource(greunits, 0, GRE_MAXUNIT, 1,
175 RF_ALLOCATED | RF_ACTIVE, NULL);
176 if (r == NULL)
177 return (ENOSPC);
178 *unit = rman_get_start(r);
179 } else {
180 r = rman_reserve_resource(greunits, *unit, *unit, 1,
181 RF_ALLOCATED | RF_ACTIVE, NULL);
182 if (r == NULL)
183 return (EEXIST);
184 }
185
186 sc = malloc(sizeof(struct gre_softc), M_GRE, M_WAITOK);
187 memset(sc, 0, sizeof(struct gre_softc));
188
189 sc->sc_if.if_name = GRENAME;
190 sc->sc_if.if_softc = sc;
191 sc->sc_if.if_unit = *unit;
192 sc->sc_if.if_snd.ifq_maxlen = IFQ_MAXLEN;
193 sc->sc_if.if_type = IFT_OTHER;
194 sc->sc_if.if_addrlen = 0;
195 sc->sc_if.if_hdrlen = 24; /* IP + GRE */
196 sc->sc_if.if_mtu = GREMTU;
197 sc->sc_if.if_flags = IFF_POINTOPOINT|IFF_MULTICAST;
198 sc->sc_if.if_output = gre_output;
199 sc->sc_if.if_ioctl = gre_ioctl;
200 sc->g_dst.s_addr = sc->g_src.s_addr = INADDR_ANY;
201 sc->g_proto = IPPROTO_GRE;
202 sc->sc_if.if_flags |= IFF_LINK0;
203 sc->encap = NULL;
204 sc->called = 0;
205 sc->r_unit = r;
206 if_attach(&sc->sc_if);
207 bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int32_t));
208 LIST_INSERT_HEAD(&gre_softc_list, sc, sc_list);
209 return (0);
210}
211
212static void
213gre_clone_destroy(ifp)
214 struct ifnet *ifp;
215{
216 int err;
217 struct gre_softc *sc = ifp->if_softc;
218
219#ifdef INET
220 if (sc->encap != NULL)
221 encap_detach(sc->encap);
222#endif
223 LIST_REMOVE(sc, sc_list);
224 bpfdetach(ifp);
225 if_detach(ifp);
226
227 err = rman_release_resource(sc->r_unit);
228 KASSERT(err == 0, ("Unexpected error freeing resource"));
229
230 free(sc, M_GRE);
231}
232
233/*
234 * The output routine. Takes a packet and encapsulates it in the protocol
235 * given by sc->g_proto. See also RFC 1701 and RFC 2004
236 */
237static int
238gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
239 struct rtentry *rt)
240{
241 int error = 0;
242 struct gre_softc *sc = ifp->if_softc;
243 struct greip *gh;
244 struct ip *ip;
245 u_char osrc;
246 u_short etype = 0;
247 struct mobile_h mob_h;
248
249 /*
250 * gre may cause infinite recursion calls when misconfigured.
251 * We'll prevent this by introducing upper limit.
252 */
253 if (++(sc->called) > max_gre_nesting) {
254 printf("%s: gre_output: recursively called too many "
255 "times(%d)\n", if_name(&sc->sc_if), sc->called);
256 m_freem(m);
257 error = EIO; /* is there better errno? */
258 goto end;
259 }
260
261 if ((ifp->if_flags & (IFF_UP | IFF_RUNNING)) == 0 ||
262 sc->g_src.s_addr == INADDR_ANY || sc->g_dst.s_addr == INADDR_ANY) {
263 m_freem(m);
264 error = ENETDOWN;
265 goto end;
266 }
267
268 gh = NULL;
269 ip = NULL;
270 osrc = 0;
271
272 if (ifp->if_bpf) {
273 /* see comment of other if_foo.c files */
274 struct mbuf m0;
275 u_int32_t af = dst->sa_family;
276
277 m0.m_next = m;
278 m0.m_len = 4;
279 m0.m_data = (char *)&af;
280
281 bpf_mtap(ifp, &m0);
282 }
283
284 m->m_flags &= ~(M_BCAST|M_MCAST);
285
286 if (sc->g_proto == IPPROTO_MOBILE) {
287 if (dst->sa_family == AF_INET) {
288 struct mbuf *m0;
289 int msiz;
290
291 ip = mtod(m, struct ip *);
292
293 /*
294 * RFC2004 specifies that fragmented diagrams shouldn't
295 * be encapsulated.
296 */
297 if ((ip->ip_off & IP_MF) != 0) {
298 IF_DROP(&ifp->if_snd);
299 m_freem(m);
300 error = EINVAL; /* is there better errno? */
301 goto end;
302 }
303 memset(&mob_h, 0, MOB_H_SIZ_L);
304 mob_h.proto = (ip->ip_p) << 8;
305 mob_h.odst = ip->ip_dst.s_addr;
306 ip->ip_dst.s_addr = sc->g_dst.s_addr;
307
308 /*
309 * If the packet comes from our host, we only change
310 * the destination address in the IP header.
311 * Else we also need to save and change the source
312 */
313 if (in_hosteq(ip->ip_src, sc->g_src)) {
314 msiz = MOB_H_SIZ_S;
315 } else {
316 mob_h.proto |= MOB_H_SBIT;
317 mob_h.osrc = ip->ip_src.s_addr;
318 ip->ip_src.s_addr = sc->g_src.s_addr;
319 msiz = MOB_H_SIZ_L;
320 }
321 mob_h.proto = htons(mob_h.proto);
322 mob_h.hcrc = gre_in_cksum((u_short *)&mob_h, msiz);
323
324 if ((m->m_data - msiz) < m->m_pktdat) {
325 /* need new mbuf */
326 MGETHDR(m0, M_DONTWAIT, MT_HEADER);
327 if (m0 == NULL) {
328 IF_DROP(&ifp->if_snd);
329 m_freem(m);
330 error = ENOBUFS;
331 goto end;
332 }
333 m0->m_next = m;
334 m->m_data += sizeof(struct ip);
335 m->m_len -= sizeof(struct ip);
336 m0->m_pkthdr.len = m->m_pkthdr.len + msiz;
337 m0->m_len = msiz + sizeof(struct ip);
338 m0->m_data += max_linkhdr;
339 memcpy(mtod(m0, caddr_t), (caddr_t)ip,
340 sizeof(struct ip));
341 m = m0;
342 } else { /* we have some space left in the old one */
343 m->m_data -= msiz;
344 m->m_len += msiz;
345 m->m_pkthdr.len += msiz;
346 bcopy(ip, mtod(m, caddr_t),
347 sizeof(struct ip));
348 }
349 ip = mtod(m, struct ip *);
350 memcpy((caddr_t)(ip + 1), &mob_h, (unsigned)msiz);
351 ip->ip_len = ntohs(ip->ip_len) + msiz;
352 } else { /* AF_INET */
353 IF_DROP(&ifp->if_snd);
354 m_freem(m);
355 error = EINVAL;
356 goto end;
357 }
358 } else if (sc->g_proto == IPPROTO_GRE) {
359 switch (dst->sa_family) {
360 case AF_INET:
361 ip = mtod(m, struct ip *);
362 etype = ETHERTYPE_IP;
363 break;
364#ifdef NETATALK
365 case AF_APPLETALK:
366 etype = ETHERTYPE_ATALK;
367 break;
368#endif
369#ifdef NS
370 case AF_NS:
371 etype = ETHERTYPE_NS;
372 break;
373#endif
374 default:
375 IF_DROP(&ifp->if_snd);
376 m_freem(m);
377 error = EAFNOSUPPORT;
378 goto end;
379 }
380 M_PREPEND(m, sizeof(struct greip), M_DONTWAIT);
381 } else {
382 IF_DROP(&ifp->if_snd);
383 m_freem(m);
384 error = EINVAL;
385 goto end;
386 }
387
388 if (m == NULL) { /* impossible */
389 IF_DROP(&ifp->if_snd);
390 error = ENOBUFS;
391 goto end;
392 }
393
394 gh = mtod(m, struct greip *);
395 if (sc->g_proto == IPPROTO_GRE) {
396 /* we don't have any GRE flags for now */
397
398 memset((void *)&gh->gi_g, 0, sizeof(struct gre_h));
399 gh->gi_ptype = htons(etype);
400 }
401
402 gh->gi_pr = sc->g_proto;
403 if (sc->g_proto != IPPROTO_MOBILE) {
404 gh->gi_src = sc->g_src;
405 gh->gi_dst = sc->g_dst;
406 ((struct ip*)gh)->ip_hl = (sizeof(struct ip)) >> 2;
407 ((struct ip*)gh)->ip_ttl = GRE_TTL;
408 ((struct ip*)gh)->ip_tos = ip->ip_tos;
409 ((struct ip*)gh)->ip_id = ip->ip_id;
410 gh->gi_len = m->m_pkthdr.len;
411 }
412
413 ifp->if_opackets++;
414 ifp->if_obytes += m->m_pkthdr.len;
415 /* send it off */
416 error = ip_output(m, NULL, &sc->route, 0, NULL, NULL);
417 end:
418 sc->called = 0;
419 if (error)
420 ifp->if_oerrors++;
421 return (error);
422}
423
424static int
425gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
426{
427 struct ifreq *ifr = (struct ifreq *)data;
428 struct if_laddrreq *lifr = (struct if_laddrreq *)data;
429 struct in_aliasreq *aifr = (struct in_aliasreq *)data;
430 struct gre_softc *sc = ifp->if_softc;
431 int s;
432 struct sockaddr_in si;
433 struct sockaddr *sa = NULL;
434 int error;
435 struct sockaddr_in sp, sm, dp, dm;
dadab5e9 436 struct thread *td = curthread;
984263bc
MD
437
438 error = 0;
439
440 s = splnet();
441 switch (cmd) {
442 case SIOCSIFADDR:
443 ifp->if_flags |= IFF_UP;
444 break;
445 case SIOCSIFDSTADDR:
446 break;
447 case SIOCSIFFLAGS:
dadab5e9 448 if ((error = suser(td)) != 0)
984263bc
MD
449 break;
450 if ((ifr->ifr_flags & IFF_LINK0) != 0)
451 sc->g_proto = IPPROTO_GRE;
452 else
453 sc->g_proto = IPPROTO_MOBILE;
454 goto recompute;
455 case SIOCSIFMTU:
dadab5e9 456 if ((error = suser(td)) != 0)
984263bc
MD
457 break;
458 if (ifr->ifr_mtu < 576) {
459 error = EINVAL;
460 break;
461 }
462 ifp->if_mtu = ifr->ifr_mtu;
463 break;
464 case SIOCGIFMTU:
465 ifr->ifr_mtu = sc->sc_if.if_mtu;
466 break;
467 case SIOCADDMULTI:
468 case SIOCDELMULTI:
dadab5e9 469 if ((error = suser(td)) != 0)
984263bc
MD
470 break;
471 if (ifr == 0) {
472 error = EAFNOSUPPORT;
473 break;
474 }
475 switch (ifr->ifr_addr.sa_family) {
476#ifdef INET
477 case AF_INET:
478 break;
479#endif
480 default:
481 error = EAFNOSUPPORT;
482 break;
483 }
484 break;
485 case GRESPROTO:
dadab5e9 486 if ((error = suser(td)) != 0)
984263bc
MD
487 break;
488 sc->g_proto = ifr->ifr_flags;
489 switch (sc->g_proto) {
490 case IPPROTO_GRE:
491 ifp->if_flags |= IFF_LINK0;
492 break;
493 case IPPROTO_MOBILE:
494 ifp->if_flags &= ~IFF_LINK0;
495 break;
496 default:
497 error = EPROTONOSUPPORT;
498 break;
499 }
500 goto recompute;
501 case GREGPROTO:
502 ifr->ifr_flags = sc->g_proto;
503 break;
504 case GRESADDRS:
505 case GRESADDRD:
dadab5e9 506 if ((error = suser(td)) != 0)
984263bc
MD
507 break;
508 /*
509 * set tunnel endpoints, compute a less specific route
510 * to the remote end and mark if as up
511 */
512 sa = &ifr->ifr_addr;
513 if (cmd == GRESADDRS)
514 sc->g_src = (satosin(sa))->sin_addr;
515 if (cmd == GRESADDRD)
516 sc->g_dst = (satosin(sa))->sin_addr;
517 recompute:
518#ifdef INET
519 if (sc->encap != NULL) {
520 encap_detach(sc->encap);
521 sc->encap = NULL;
522 }
523#endif
524 if ((sc->g_src.s_addr != INADDR_ANY) &&
525 (sc->g_dst.s_addr != INADDR_ANY)) {
526 bzero(&sp, sizeof(sp));
527 bzero(&sm, sizeof(sm));
528 bzero(&dp, sizeof(dp));
529 bzero(&dm, sizeof(dm));
530 sp.sin_len = sm.sin_len = dp.sin_len = dm.sin_len =
531 sizeof(struct sockaddr_in);
532 sp.sin_family = sm.sin_family = dp.sin_family =
533 dm.sin_family = AF_INET;
534 sp.sin_addr = sc->g_src;
535 dp.sin_addr = sc->g_dst;
536 sm.sin_addr.s_addr = dm.sin_addr.s_addr =
537 INADDR_BROADCAST;
538#ifdef INET
539 sc->encap = encap_attach(AF_INET, sc->g_proto,
540 sintosa(&sp), sintosa(&sm), sintosa(&dp),
541 sintosa(&dm), (sc->g_proto == IPPROTO_GRE) ?
542 &in_gre_protosw : &in_mobile_protosw, sc);
543 if (sc->encap == NULL)
544 printf("%s: unable to attach encap\n",
545 if_name(&sc->sc_if));
546#endif
547 if (sc->route.ro_rt != 0) /* free old route */
548 RTFREE(sc->route.ro_rt);
549 if (gre_compute_route(sc) == 0)
550 ifp->if_flags |= IFF_RUNNING;
551 else
552 ifp->if_flags &= ~IFF_RUNNING;
553 }
554 break;
555 case GREGADDRS:
556 memset(&si, 0, sizeof(si));
557 si.sin_family = AF_INET;
558 si.sin_len = sizeof(struct sockaddr_in);
559 si.sin_addr.s_addr = sc->g_src.s_addr;
560 sa = sintosa(&si);
561 ifr->ifr_addr = *sa;
562 break;
563 case GREGADDRD:
564 memset(&si, 0, sizeof(si));
565 si.sin_family = AF_INET;
566 si.sin_len = sizeof(struct sockaddr_in);
567 si.sin_addr.s_addr = sc->g_dst.s_addr;
568 sa = sintosa(&si);
569 ifr->ifr_addr = *sa;
570 break;
571 case SIOCSIFPHYADDR:
dadab5e9 572 if ((error = suser(td)) != 0)
984263bc
MD
573 break;
574 if (aifr->ifra_addr.sin_family != AF_INET ||
575 aifr->ifra_dstaddr.sin_family != AF_INET) {
576 error = EAFNOSUPPORT;
577 break;
578 }
579 if (aifr->ifra_addr.sin_len != sizeof(si) ||
580 aifr->ifra_dstaddr.sin_len != sizeof(si)) {
581 error = EINVAL;
582 break;
583 }
584 sc->g_src = aifr->ifra_addr.sin_addr;
585 sc->g_dst = aifr->ifra_dstaddr.sin_addr;
586 goto recompute;
587 case SIOCSLIFPHYADDR:
dadab5e9 588 if ((error = suser(td)) != 0)
984263bc
MD
589 break;
590 if (lifr->addr.ss_family != AF_INET ||
591 lifr->dstaddr.ss_family != AF_INET) {
592 error = EAFNOSUPPORT;
593 break;
594 }
595 if (lifr->addr.ss_len != sizeof(si) ||
596 lifr->dstaddr.ss_len != sizeof(si)) {
597 error = EINVAL;
598 break;
599 }
600 sc->g_src = (satosin((struct sockadrr *)&lifr->addr))->sin_addr;
601 sc->g_dst =
602 (satosin((struct sockadrr *)&lifr->dstaddr))->sin_addr;
603 goto recompute;
604 case SIOCDIFPHYADDR:
dadab5e9 605 if ((error = suser(td)) != 0)
984263bc
MD
606 break;
607 sc->g_src.s_addr = INADDR_ANY;
608 sc->g_dst.s_addr = INADDR_ANY;
609 goto recompute;
610 case SIOCGLIFPHYADDR:
611 if (sc->g_src.s_addr == INADDR_ANY ||
612 sc->g_dst.s_addr == INADDR_ANY) {
613 error = EADDRNOTAVAIL;
614 break;
615 }
616 memset(&si, 0, sizeof(si));
617 si.sin_family = AF_INET;
618 si.sin_len = sizeof(struct sockaddr_in);
619 si.sin_addr.s_addr = sc->g_src.s_addr;
620 memcpy(&lifr->addr, &si, sizeof(si));
621 si.sin_addr.s_addr = sc->g_dst.s_addr;
622 memcpy(&lifr->dstaddr, &si, sizeof(si));
623 break;
624 case SIOCGIFPSRCADDR:
625 if (sc->g_src.s_addr == INADDR_ANY) {
626 error = EADDRNOTAVAIL;
627 break;
628 }
629 memset(&si, 0, sizeof(si));
630 si.sin_family = AF_INET;
631 si.sin_len = sizeof(struct sockaddr_in);
632 si.sin_addr.s_addr = sc->g_src.s_addr;
633 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr));
634 break;
635 case SIOCGIFPDSTADDR:
636 if (sc->g_dst.s_addr == INADDR_ANY) {
637 error = EADDRNOTAVAIL;
638 break;
639 }
640 memset(&si, 0, sizeof(si));
641 si.sin_family = AF_INET;
642 si.sin_len = sizeof(struct sockaddr_in);
643 si.sin_addr.s_addr = sc->g_dst.s_addr;
644 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr));
645 break;
646 default:
647 error = EINVAL;
648 break;
649 }
650
651 splx(s);
652 return (error);
653}
654
655/*
656 * computes a route to our destination that is not the one
657 * which would be taken by ip_output(), as this one will loop back to
658 * us. If the interface is p2p as a--->b, then a routing entry exists
659 * If we now send a packet to b (e.g. ping b), this will come down here
660 * gets src=a, dst=b tacked on and would from ip_ouput() sent back to
661 * if_gre.
662 * Goal here is to compute a route to b that is less specific than
663 * a-->b. We know that this one exists as in normal operation we have
664 * at least a default route which matches.
665 */
666static int
667gre_compute_route(struct gre_softc *sc)
668{
669 struct route *ro;
670 u_int32_t a, b, c;
671
672 ro = &sc->route;
673
674 memset(ro, 0, sizeof(struct route));
675 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst;
676 ro->ro_dst.sa_family = AF_INET;
677 ro->ro_dst.sa_len = sizeof(ro->ro_dst);
678
679 /*
680 * toggle last bit, so our interface is not found, but a less
681 * specific route. I'd rather like to specify a shorter mask,
682 * but this is not possible. Should work though. XXX
683 * there is a simpler way ...
684 */
685 if ((sc->sc_if.if_flags & IFF_LINK1) == 0) {
686 a = ntohl(sc->g_dst.s_addr);
687 b = a & 0x01;
688 c = a & 0xfffffffe;
689 b = b ^ 0x01;
690 a = b | c;
691 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr.s_addr
692 = htonl(a);
693 }
694
695#ifdef DIAGNOSTIC
696 printf("%s: searching a route to %s", if_name(&sc->sc_if),
697 inet_ntoa(((struct sockaddr_in *)&ro->ro_dst)->sin_addr));
698#endif
699
700 rtalloc(ro);
701
702 /*
703 * check if this returned a route at all and this route is no
704 * recursion to ourself
705 */
706 if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp->if_softc == sc) {
707#ifdef DIAGNOSTIC
708 if (ro->ro_rt == NULL)
709 printf(" - no route found!\n");
710 else
711 printf(" - route loops back to ourself!\n");
712#endif
713 return EADDRNOTAVAIL;
714 }
715
716 /*
717 * now change it back - else ip_output will just drop
718 * the route and search one to this interface ...
719 */
720 if ((sc->sc_if.if_flags & IFF_LINK1) == 0)
721 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst;
722
723#ifdef DIAGNOSTIC
724 printf(", choosing %s with gateway %s", if_name(ro->ro_rt->rt_ifp),
725 inet_ntoa(((struct sockaddr_in *)(ro->ro_rt->rt_gateway))->sin_addr));
726 printf("\n");
727#endif
728
729 return 0;
730}
731
732/*
733 * do a checksum of a buffer - much like in_cksum, which operates on
734 * mbufs.
735 */
736u_short
737gre_in_cksum(u_short *p, u_int len)
738{
739 u_int sum = 0;
740 int nwords = len >> 1;
741
742 while (nwords-- != 0)
743 sum += *p++;
744
745 if (len & 1) {
746 union {
747 u_short w;
748 u_char c[2];
749 } u;
750 u.c[0] = *(u_char *)p;
751 u.c[1] = 0;
752 sum += u.w;
753 }
754
755 /* end-around-carry */
756 sum = (sum >> 16) + (sum & 0xffff);
757 sum += (sum >> 16);
758 return (~sum);
759}
760
761static int
762gremodevent(module_t mod, int type, void *data)
763{
764 int err;
765
766 switch (type) {
767 case MOD_LOAD:
768 greunits->rm_type = RMAN_ARRAY;
769 greunits->rm_descr = "configurable if_gre units";
770 err = rman_init(greunits);
771 if (err != 0)
772 return (err);
773 err = rman_manage_region(greunits, 0, GRE_MAXUNIT);
774 if (err != 0) {
775 printf("%s: greunits: rman_manage_region: Failed %d\n",
776 GRENAME, err);
777 rman_fini(greunits);
778 return (err);
779 }
780 greattach();
781 break;
782 case MOD_UNLOAD:
783 if_clone_detach(&gre_cloner);
784
785 while (!LIST_EMPTY(&gre_softc_list))
786 gre_clone_destroy(&LIST_FIRST(&gre_softc_list)->sc_if);
787
788 err = rman_fini(greunits);
789 if (err != 0)
790 return (err);
791
792 break;
793 }
794 return 0;
795}
796
797static moduledata_t gre_mod = {
798 "if_gre",
799 gremodevent,
800 0
801};
802
803DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
804MODULE_VERSION(if_gre, 1);