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sys/net/if_gre.c
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1 /* $NetBSD: if_gre.c,v 1.49 2003/12/11 00:22:29 itojun Exp $ */ 2 /* $FreeBSD$ */ 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 * 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 * 3. All advertising materials mentioning features or use of this software 22 * must display the following acknowledgement: 23 * This product includes software developed by the NetBSD 24 * Foundation, Inc. and its contributors. 25 * 4. Neither the name of The NetBSD Foundation nor the names of its 26 * contributors may be used to endorse or promote products derived 27 * from this software without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 30 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 31 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 32 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 33 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 34 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 35 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 36 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 37 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 38 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 39 * POSSIBILITY OF SUCH DAMAGE. 40 */ 41 42 /* 43 * Encapsulate L3 protocols into IP 44 * See RFC 2784 (successor of RFC 1701 and 1702) for more details. 45 * If_gre is compatible with Cisco GRE tunnels, so you can 46 * have a NetBSD box as the other end of a tunnel interface of a Cisco 47 * router. See gre(4) for more details. 48 * Also supported: IP in IP encaps (proto 55) as of RFC 2004 49 */ 50 51 #include "opt_atalk.h" 52 #include "opt_inet.h" 53 #include "opt_inet6.h" 54 55 #include <sys/param.h> 56 #include <sys/kernel.h> 57 #include <sys/malloc.h> 58 #include <sys/module.h> 59 #include <sys/mbuf.h> 60 #include <sys/protosw.h> 61 #include <sys/socket.h> 62 #include <sys/sockio.h> 63 #include <sys/sysctl.h> 64 #include <sys/systm.h> 65 66 #include <net/ethernet.h> 67 #include <net/if.h> 68 #include <net/if_clone.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 98 /* 99 * gre_mtx protects all global variables in if_gre.c. 100 * XXX: gre_softc data not protected yet. 101 */ 102 struct mtx gre_mtx; 103 static MALLOC_DEFINE(M_GRE, GRENAME, "Generic Routing Encapsulation"); 104 105 struct gre_softc_head gre_softc_list; 106 107 static int gre_clone_create(struct if_clone *, int); 108 static void gre_clone_destroy(struct ifnet *); 109 static int gre_ioctl(struct ifnet *, u_long, caddr_t); 110 static int gre_output(struct ifnet *, struct mbuf *, struct sockaddr *, 111 struct rtentry *rt); 112 113 IFC_SIMPLE_DECLARE(gre, 0); 114 115 static int gre_compute_route(struct gre_softc *sc); 116 117 static void greattach(void); 118 119 #ifdef INET 120 extern struct domain inetdomain; 121 static const struct protosw in_gre_protosw = { 122 .pr_type = SOCK_RAW, 123 .pr_domain = &inetdomain, 124 .pr_protocol = IPPROTO_GRE, 125 .pr_flags = PR_ATOMIC|PR_ADDR, 126 .pr_input = gre_input, 127 .pr_output = (pr_output_t *)rip_output, 128 .pr_ctlinput = rip_ctlinput, 129 .pr_ctloutput = rip_ctloutput, 130 .pr_usrreqs = &rip_usrreqs 131 }; 132 static const struct protosw in_mobile_protosw = { 133 .pr_type = SOCK_RAW, 134 .pr_domain = &inetdomain, 135 .pr_protocol = IPPROTO_MOBILE, 136 .pr_flags = PR_ATOMIC|PR_ADDR, 137 .pr_input = gre_mobile_input, 138 .pr_output = (pr_output_t *)rip_output, 139 .pr_ctlinput = rip_ctlinput, 140 .pr_ctloutput = rip_ctloutput, 141 .pr_usrreqs = &rip_usrreqs 142 }; 143 #endif 144 145 SYSCTL_DECL(_net_link); 146 SYSCTL_NODE(_net_link, IFT_TUNNEL, gre, CTLFLAG_RW, 0, 147 "Generic Routing Encapsulation"); 148 #ifndef MAX_GRE_NEST 149 /* 150 * This macro controls the default upper limitation on nesting of gre tunnels. 151 * Since, setting a large value to this macro with a careless configuration 152 * may introduce system crash, we don't allow any nestings by default. 153 * If you need to configure nested gre tunnels, you can define this macro 154 * in your kernel configuration file. However, if you do so, please be 155 * careful to configure the tunnels so that it won't make a loop. 156 */ 157 #define MAX_GRE_NEST 1 158 #endif 159 static int max_gre_nesting = MAX_GRE_NEST; 160 SYSCTL_INT(_net_link_gre, OID_AUTO, max_nesting, CTLFLAG_RW, 161 &max_gre_nesting, 0, "Max nested tunnels"); 162 163 /* ARGSUSED */ 164 static void 165 greattach(void) 166 { 167 168 mtx_init(&gre_mtx, "gre_mtx", NULL, MTX_DEF); 169 LIST_INIT(&gre_softc_list); 170 if_clone_attach(&gre_cloner); 171 } 172 173 static int 174 gre_clone_create(ifc, unit) 175 struct if_clone *ifc; 176 int unit; 177 { 178 struct gre_softc *sc; 179 180 sc = malloc(sizeof(struct gre_softc), M_GRE, M_WAITOK | M_ZERO); 181 182 GRE2IFP(sc) = if_alloc(IFT_TUNNEL); 183 if (GRE2IFP(sc) == NULL) { 184 free(sc, M_GRE); 185 return (ENOSPC); 186 } 187 188 GRE2IFP(sc)->if_softc = sc; 189 if_initname(GRE2IFP(sc), ifc->ifc_name, unit); 190 191 GRE2IFP(sc)->if_snd.ifq_maxlen = IFQ_MAXLEN; 192 GRE2IFP(sc)->if_addrlen = 0; 193 GRE2IFP(sc)->if_hdrlen = 24; /* IP + GRE */ 194 GRE2IFP(sc)->if_mtu = GREMTU; 195 GRE2IFP(sc)->if_flags = IFF_POINTOPOINT|IFF_MULTICAST; 196 GRE2IFP(sc)->if_output = gre_output; 197 GRE2IFP(sc)->if_ioctl = gre_ioctl; 198 sc->g_dst.s_addr = sc->g_src.s_addr = INADDR_ANY; 199 sc->g_proto = IPPROTO_GRE; 200 GRE2IFP(sc)->if_flags |= IFF_LINK0; 201 sc->encap = NULL; 202 sc->called = 0; 203 sc->wccp_ver = WCCP_V1; 204 if_attach(GRE2IFP(sc)); 205 bpfattach(GRE2IFP(sc), DLT_NULL, sizeof(u_int32_t)); 206 mtx_lock(&gre_mtx); 207 LIST_INSERT_HEAD(&gre_softc_list, sc, sc_list); 208 mtx_unlock(&gre_mtx); 209 return (0); 210 } 211 212 static void 213 gre_destroy(struct gre_softc *sc) 214 { 215 216 #ifdef INET 217 if (sc->encap != NULL) 218 encap_detach(sc->encap); 219 #endif 220 bpfdetach(GRE2IFP(sc)); 221 if_detach(GRE2IFP(sc)); 222 if_free(GRE2IFP(sc)); 223 free(sc, M_GRE); 224 } 225 226 static void 227 gre_clone_destroy(ifp) 228 struct ifnet *ifp; 229 { 230 struct gre_softc *sc = ifp->if_softc; 231 232 mtx_lock(&gre_mtx); 233 LIST_REMOVE(sc, sc_list); 234 mtx_unlock(&gre_mtx); 235 gre_destroy(sc); 236 } 237 238 /* 239 * The output routine. Takes a packet and encapsulates it in the protocol 240 * given by sc->g_proto. See also RFC 1701 and RFC 2004 241 */ 242 static int 243 gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 244 struct rtentry *rt) 245 { 246 int error = 0; 247 struct gre_softc *sc = ifp->if_softc; 248 struct greip *gh; 249 struct ip *ip; 250 u_short ip_id = 0; 251 uint8_t ip_tos = 0; 252 u_int16_t etype = 0; 253 struct mobile_h mob_h; 254 u_int32_t af; 255 256 /* 257 * gre may cause infinite recursion calls when misconfigured. 258 * We'll prevent this by introducing upper limit. 259 */ 260 if (++(sc->called) > max_gre_nesting) { 261 printf("%s: gre_output: recursively called too many " 262 "times(%d)\n", if_name(GRE2IFP(sc)), sc->called); 263 m_freem(m); 264 error = EIO; /* is there better errno? */ 265 goto end; 266 } 267 268 if (!((ifp->if_flags & IFF_UP) && 269 (ifp->if_drv_flags & IFF_DRV_RUNNING)) || 270 sc->g_src.s_addr == INADDR_ANY || sc->g_dst.s_addr == INADDR_ANY) { 271 m_freem(m); 272 error = ENETDOWN; 273 goto end; 274 } 275 276 gh = NULL; 277 ip = NULL; 278 279 /* BPF writes need to be handled specially. */ 280 if (dst->sa_family == AF_UNSPEC) { 281 bcopy(dst->sa_data, &af, sizeof(af)); 282 dst->sa_family = af; 283 } 284 285 if (bpf_peers_present(ifp->if_bpf)) { 286 af = dst->sa_family; 287 bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m); 288 } 289 290 m->m_flags &= ~(M_BCAST|M_MCAST); 291 292 if (sc->g_proto == IPPROTO_MOBILE) { 293 if (dst->sa_family == AF_INET) { 294 struct mbuf *m0; 295 int msiz; 296 297 ip = mtod(m, struct ip *); 298 299 /* 300 * RFC2004 specifies that fragmented diagrams shouldn't 301 * be encapsulated. 302 */ 303 if (ip->ip_off & (IP_MF | IP_OFFMASK)) { 304 _IF_DROP(&ifp->if_snd); 305 m_freem(m); 306 error = EINVAL; /* is there better errno? */ 307 goto end; 308 } 309 memset(&mob_h, 0, MOB_H_SIZ_L); 310 mob_h.proto = (ip->ip_p) << 8; 311 mob_h.odst = ip->ip_dst.s_addr; 312 ip->ip_dst.s_addr = sc->g_dst.s_addr; 313 314 /* 315 * If the packet comes from our host, we only change 316 * the destination address in the IP header. 317 * Else we also need to save and change the source 318 */ 319 if (in_hosteq(ip->ip_src, sc->g_src)) { 320 msiz = MOB_H_SIZ_S; 321 } else { 322 mob_h.proto |= MOB_H_SBIT; 323 mob_h.osrc = ip->ip_src.s_addr; 324 ip->ip_src.s_addr = sc->g_src.s_addr; 325 msiz = MOB_H_SIZ_L; 326 } 327 mob_h.proto = htons(mob_h.proto); 328 mob_h.hcrc = gre_in_cksum((u_int16_t *)&mob_h, msiz); 329 330 if ((m->m_data - msiz) < m->m_pktdat) { 331 /* need new mbuf */ 332 MGETHDR(m0, M_DONTWAIT, MT_HEADER); 333 if (m0 == NULL) { 334 _IF_DROP(&ifp->if_snd); 335 m_freem(m); 336 error = ENOBUFS; 337 goto end; 338 } 339 m0->m_next = m; 340 m->m_data += sizeof(struct ip); 341 m->m_len -= sizeof(struct ip); 342 m0->m_pkthdr.len = m->m_pkthdr.len + msiz; 343 m0->m_len = msiz + sizeof(struct ip); 344 m0->m_data += max_linkhdr; 345 memcpy(mtod(m0, caddr_t), (caddr_t)ip, 346 sizeof(struct ip)); 347 m = m0; 348 } else { /* we have some space left in the old one */ 349 m->m_data -= msiz; 350 m->m_len += msiz; 351 m->m_pkthdr.len += msiz; 352 bcopy(ip, mtod(m, caddr_t), 353 sizeof(struct ip)); 354 } 355 ip = mtod(m, struct ip *); 356 memcpy((caddr_t)(ip + 1), &mob_h, (unsigned)msiz); 357 ip->ip_len = ntohs(ip->ip_len) + msiz; 358 } else { /* AF_INET */ 359 _IF_DROP(&ifp->if_snd); 360 m_freem(m); 361 error = EINVAL; 362 goto end; 363 } 364 } else if (sc->g_proto == IPPROTO_GRE) { 365 switch (dst->sa_family) { 366 case AF_INET: 367 ip = mtod(m, struct ip *); 368 ip_tos = ip->ip_tos; 369 ip_id = ip->ip_id; 370 etype = ETHERTYPE_IP; 371 break; 372 #ifdef INET6 373 case AF_INET6: 374 ip_id = ip_newid(); 375 etype = ETHERTYPE_IPV6; 376 break; 377 #endif 378 #ifdef NETATALK 379 case AF_APPLETALK: 380 etype = ETHERTYPE_ATALK; 381 break; 382 #endif 383 default: 384 _IF_DROP(&ifp->if_snd); 385 m_freem(m); 386 error = EAFNOSUPPORT; 387 goto end; 388 } 389 M_PREPEND(m, sizeof(struct greip), M_DONTWAIT); 390 } else { 391 _IF_DROP(&ifp->if_snd); 392 m_freem(m); 393 error = EINVAL; 394 goto end; 395 } 396 397 if (m == NULL) { /* mbuf allocation failed */ 398 _IF_DROP(&ifp->if_snd); 399 error = ENOBUFS; 400 goto end; 401 } 402 403 gh = mtod(m, struct greip *); 404 if (sc->g_proto == IPPROTO_GRE) { 405 /* we don't have any GRE flags for now */ 406 memset((void *)gh, 0, sizeof(struct greip)); 407 gh->gi_ptype = htons(etype); 408 } 409 410 gh->gi_pr = sc->g_proto; 411 if (sc->g_proto != IPPROTO_MOBILE) { 412 gh->gi_src = sc->g_src; 413 gh->gi_dst = sc->g_dst; 414 ((struct ip*)gh)->ip_v = IPPROTO_IPV4; 415 ((struct ip*)gh)->ip_hl = (sizeof(struct ip)) >> 2; 416 ((struct ip*)gh)->ip_ttl = GRE_TTL; 417 ((struct ip*)gh)->ip_tos = ip_tos; 418 ((struct ip*)gh)->ip_id = ip_id; 419 gh->gi_len = m->m_pkthdr.len; 420 } 421 422 ifp->if_opackets++; 423 ifp->if_obytes += m->m_pkthdr.len; 424 /* 425 * Send it off and with IP_FORWARD flag to prevent it from 426 * overwriting the ip_id again. ip_id is already set to the 427 * ip_id of the encapsulated packet. 428 */ 429 error = ip_output(m, NULL, &sc->route, IP_FORWARDING, 430 (struct ip_moptions *)NULL, (struct inpcb *)NULL); 431 end: 432 sc->called = 0; 433 if (error) 434 ifp->if_oerrors++; 435 return (error); 436 } 437 438 static int 439 gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 440 { 441 struct ifreq *ifr = (struct ifreq *)data; 442 struct if_laddrreq *lifr = (struct if_laddrreq *)data; 443 struct in_aliasreq *aifr = (struct in_aliasreq *)data; 444 struct gre_softc *sc = ifp->if_softc; 445 int s; 446 struct sockaddr_in si; 447 struct sockaddr *sa = NULL; 448 int error; 449 struct sockaddr_in sp, sm, dp, dm; 450 451 error = 0; 452 453 s = splnet(); 454 switch (cmd) { 455 case SIOCSIFADDR: 456 ifp->if_flags |= IFF_UP; 457 break; 458 case SIOCSIFDSTADDR: 459 break; 460 case SIOCSIFFLAGS: 461 if ((error = suser(curthread)) != 0) 462 break; 463 if ((ifr->ifr_flags & IFF_LINK0) != 0) 464 sc->g_proto = IPPROTO_GRE; 465 else 466 sc->g_proto = IPPROTO_MOBILE; 467 if ((ifr->ifr_flags & IFF_LINK2) != 0) 468 sc->wccp_ver = WCCP_V2; 469 else 470 sc->wccp_ver = WCCP_V1; 471 goto recompute; 472 case SIOCSIFMTU: 473 if ((error = suser(curthread)) != 0) 474 break; 475 if (ifr->ifr_mtu < 576) { 476 error = EINVAL; 477 break; 478 } 479 ifp->if_mtu = ifr->ifr_mtu; 480 break; 481 case SIOCGIFMTU: 482 ifr->ifr_mtu = GRE2IFP(sc)->if_mtu; 483 break; 484 case SIOCADDMULTI: 485 case SIOCDELMULTI: 486 if ((error = suser(curthread)) != 0) 487 break; 488 if (ifr == 0) { 489 error = EAFNOSUPPORT; 490 break; 491 } 492 switch (ifr->ifr_addr.sa_family) { 493 #ifdef INET 494 case AF_INET: 495 break; 496 #endif 497 #ifdef INET6 498 case AF_INET6: 499 break; 500 #endif 501 default: 502 error = EAFNOSUPPORT; 503 break; 504 } 505 break; 506 case GRESPROTO: 507 if ((error = suser(curthread)) != 0) 508 break; 509 sc->g_proto = ifr->ifr_flags; 510 switch (sc->g_proto) { 511 case IPPROTO_GRE: 512 ifp->if_flags |= IFF_LINK0; 513 break; 514 case IPPROTO_MOBILE: 515 ifp->if_flags &= ~IFF_LINK0; 516 break; 517 default: 518 error = EPROTONOSUPPORT; 519 break; 520 } 521 goto recompute; 522 case GREGPROTO: 523 ifr->ifr_flags = sc->g_proto; 524 break; 525 case GRESADDRS: 526 case GRESADDRD: 527 if ((error = suser(curthread)) != 0) 528 break; 529 /* 530 * set tunnel endpoints, compute a less specific route 531 * to the remote end and mark if as up 532 */ 533 sa = &ifr->ifr_addr; 534 if (cmd == GRESADDRS) 535 sc->g_src = (satosin(sa))->sin_addr; 536 if (cmd == GRESADDRD) 537 sc->g_dst = (satosin(sa))->sin_addr; 538 recompute: 539 #ifdef INET 540 if (sc->encap != NULL) { 541 encap_detach(sc->encap); 542 sc->encap = NULL; 543 } 544 #endif 545 if ((sc->g_src.s_addr != INADDR_ANY) && 546 (sc->g_dst.s_addr != INADDR_ANY)) { 547 bzero(&sp, sizeof(sp)); 548 bzero(&sm, sizeof(sm)); 549 bzero(&dp, sizeof(dp)); 550 bzero(&dm, sizeof(dm)); 551 sp.sin_len = sm.sin_len = dp.sin_len = dm.sin_len = 552 sizeof(struct sockaddr_in); 553 sp.sin_family = sm.sin_family = dp.sin_family = 554 dm.sin_family = AF_INET; 555 sp.sin_addr = sc->g_src; 556 dp.sin_addr = sc->g_dst; 557 sm.sin_addr.s_addr = dm.sin_addr.s_addr = 558 INADDR_BROADCAST; 559 #ifdef INET 560 sc->encap = encap_attach(AF_INET, sc->g_proto, 561 sintosa(&sp), sintosa(&sm), sintosa(&dp), 562 sintosa(&dm), (sc->g_proto == IPPROTO_GRE) ? 563 &in_gre_protosw : &in_mobile_protosw, sc); 564 if (sc->encap == NULL) 565 printf("%s: unable to attach encap\n", 566 if_name(GRE2IFP(sc))); 567 #endif 568 if (sc->route.ro_rt != 0) /* free old route */ 569 RTFREE(sc->route.ro_rt); 570 if (gre_compute_route(sc) == 0) 571 ifp->if_drv_flags |= IFF_DRV_RUNNING; 572 else 573 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 574 } 575 break; 576 case GREGADDRS: 577 memset(&si, 0, sizeof(si)); 578 si.sin_family = AF_INET; 579 si.sin_len = sizeof(struct sockaddr_in); 580 si.sin_addr.s_addr = sc->g_src.s_addr; 581 sa = sintosa(&si); 582 ifr->ifr_addr = *sa; 583 break; 584 case GREGADDRD: 585 memset(&si, 0, sizeof(si)); 586 si.sin_family = AF_INET; 587 si.sin_len = sizeof(struct sockaddr_in); 588 si.sin_addr.s_addr = sc->g_dst.s_addr; 589 sa = sintosa(&si); 590 ifr->ifr_addr = *sa; 591 break; 592 case SIOCSIFPHYADDR: 593 if ((error = suser(curthread)) != 0) 594 break; 595 if (aifr->ifra_addr.sin_family != AF_INET || 596 aifr->ifra_dstaddr.sin_family != AF_INET) { 597 error = EAFNOSUPPORT; 598 break; 599 } 600 if (aifr->ifra_addr.sin_len != sizeof(si) || 601 aifr->ifra_dstaddr.sin_len != sizeof(si)) { 602 error = EINVAL; 603 break; 604 } 605 sc->g_src = aifr->ifra_addr.sin_addr; 606 sc->g_dst = aifr->ifra_dstaddr.sin_addr; 607 goto recompute; 608 case SIOCSLIFPHYADDR: 609 if ((error = suser(curthread)) != 0) 610 break; 611 if (lifr->addr.ss_family != AF_INET || 612 lifr->dstaddr.ss_family != AF_INET) { 613 error = EAFNOSUPPORT; 614 break; 615 } 616 if (lifr->addr.ss_len != sizeof(si) || 617 lifr->dstaddr.ss_len != sizeof(si)) { 618 error = EINVAL; 619 break; 620 } 621 sc->g_src = (satosin(&lifr->addr))->sin_addr; 622 sc->g_dst = 623 (satosin(&lifr->dstaddr))->sin_addr; 624 goto recompute; 625 case SIOCDIFPHYADDR: 626 if ((error = suser(curthread)) != 0) 627 break; 628 sc->g_src.s_addr = INADDR_ANY; 629 sc->g_dst.s_addr = INADDR_ANY; 630 goto recompute; 631 case SIOCGLIFPHYADDR: 632 if (sc->g_src.s_addr == INADDR_ANY || 633 sc->g_dst.s_addr == INADDR_ANY) { 634 error = EADDRNOTAVAIL; 635 break; 636 } 637 memset(&si, 0, sizeof(si)); 638 si.sin_family = AF_INET; 639 si.sin_len = sizeof(struct sockaddr_in); 640 si.sin_addr.s_addr = sc->g_src.s_addr; 641 memcpy(&lifr->addr, &si, sizeof(si)); 642 si.sin_addr.s_addr = sc->g_dst.s_addr; 643 memcpy(&lifr->dstaddr, &si, sizeof(si)); 644 break; 645 case SIOCGIFPSRCADDR: 646 #ifdef INET6 647 case SIOCGIFPSRCADDR_IN6: 648 #endif 649 if (sc->g_src.s_addr == INADDR_ANY) { 650 error = EADDRNOTAVAIL; 651 break; 652 } 653 memset(&si, 0, sizeof(si)); 654 si.sin_family = AF_INET; 655 si.sin_len = sizeof(struct sockaddr_in); 656 si.sin_addr.s_addr = sc->g_src.s_addr; 657 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr)); 658 break; 659 case SIOCGIFPDSTADDR: 660 #ifdef INET6 661 case SIOCGIFPDSTADDR_IN6: 662 #endif 663 if (sc->g_dst.s_addr == INADDR_ANY) { 664 error = EADDRNOTAVAIL; 665 break; 666 } 667 memset(&si, 0, sizeof(si)); 668 si.sin_family = AF_INET; 669 si.sin_len = sizeof(struct sockaddr_in); 670 si.sin_addr.s_addr = sc->g_dst.s_addr; 671 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr)); 672 break; 673 default: 674 error = EINVAL; 675 break; 676 } 677 678 splx(s); 679 return (error); 680 } 681 682 /* 683 * computes a route to our destination that is not the one 684 * which would be taken by ip_output(), as this one will loop back to 685 * us. If the interface is p2p as a--->b, then a routing entry exists 686 * If we now send a packet to b (e.g. ping b), this will come down here 687 * gets src=a, dst=b tacked on and would from ip_output() sent back to 688 * if_gre. 689 * Goal here is to compute a route to b that is less specific than 690 * a-->b. We know that this one exists as in normal operation we have 691 * at least a default route which matches. 692 */ 693 static int 694 gre_compute_route(struct gre_softc *sc) 695 { 696 struct route *ro; 697 u_int32_t a, b, c; 698 699 ro = &sc->route; 700 701 memset(ro, 0, sizeof(struct route)); 702 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst; 703 ro->ro_dst.sa_family = AF_INET; 704 ro->ro_dst.sa_len = sizeof(ro->ro_dst); 705 706 /* 707 * toggle last bit, so our interface is not found, but a less 708 * specific route. I'd rather like to specify a shorter mask, 709 * but this is not possible. Should work though. XXX 710 * there is a simpler way ... 711 */ 712 if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0) { 713 a = ntohl(sc->g_dst.s_addr); 714 b = a & 0x01; 715 c = a & 0xfffffffe; 716 b = b ^ 0x01; 717 a = b | c; 718 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr.s_addr 719 = htonl(a); 720 } 721 722 #ifdef DIAGNOSTIC 723 printf("%s: searching for a route to %s", if_name(GRE2IFP(sc)), 724 inet_ntoa(((struct sockaddr_in *)&ro->ro_dst)->sin_addr)); 725 #endif 726 727 rtalloc(ro); 728 729 /* 730 * check if this returned a route at all and this route is no 731 * recursion to ourself 732 */ 733 if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp->if_softc == sc) { 734 #ifdef DIAGNOSTIC 735 if (ro->ro_rt == NULL) 736 printf(" - no route found!\n"); 737 else 738 printf(" - route loops back to ourself!\n"); 739 #endif 740 return EADDRNOTAVAIL; 741 } 742 743 /* 744 * now change it back - else ip_output will just drop 745 * the route and search one to this interface ... 746 */ 747 if ((GRE2IFP(sc)->if_flags & IFF_LINK1) == 0) 748 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst; 749 750 #ifdef DIAGNOSTIC 751 printf(", choosing %s with gateway %s", if_name(ro->ro_rt->rt_ifp), 752 inet_ntoa(((struct sockaddr_in *)(ro->ro_rt->rt_gateway))->sin_addr)); 753 printf("\n"); 754 #endif 755 756 return 0; 757 } 758 759 /* 760 * do a checksum of a buffer - much like in_cksum, which operates on 761 * mbufs. 762 */ 763 u_int16_t 764 gre_in_cksum(u_int16_t *p, u_int len) 765 { 766 u_int32_t sum = 0; 767 int nwords = len >> 1; 768 769 while (nwords-- != 0) 770 sum += *p++; 771 772 if (len & 1) { 773 union { 774 u_short w; 775 u_char c[2]; 776 } u; 777 u.c[0] = *(u_char *)p; 778 u.c[1] = 0; 779 sum += u.w; 780 } 781 782 /* end-around-carry */ 783 sum = (sum >> 16) + (sum & 0xffff); 784 sum += (sum >> 16); 785 return (~sum); 786 } 787 788 static int 789 gremodevent(module_t mod, int type, void *data) 790 { 791 struct gre_softc *sc; 792 793 switch (type) { 794 case MOD_LOAD: 795 greattach(); 796 break; 797 case MOD_UNLOAD: 798 if_clone_detach(&gre_cloner); 799 800 mtx_lock(&gre_mtx); 801 while ((sc = LIST_FIRST(&gre_softc_list)) != NULL) { 802 LIST_REMOVE(sc, sc_list); 803 mtx_unlock(&gre_mtx); 804 gre_destroy(sc); 805 mtx_lock(&gre_mtx); 806 } 807 mtx_unlock(&gre_mtx); 808 mtx_destroy(&gre_mtx); 809 break; 810 default: 811 return EOPNOTSUPP; 812 } 813 return 0; 814 } 815 816 static moduledata_t gre_mod = { 817 "if_gre", 818 gremodevent, 819 0 820 }; 821 822 DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 823 MODULE_VERSION(if_gre, 1);
Cache object: b532babe820236d134a911be995ee07e
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