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