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 $ */ 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_inet.h" 50 51 #include <sys/param.h> 52 #include <sys/kernel.h> 53 #include <sys/bus.h> 54 #include <sys/malloc.h> 55 #include <sys/mbuf.h> 56 #include <sys/proc.h> 57 #include <sys/caps.h> 58 #include <sys/protosw.h> 59 #include <sys/socket.h> 60 #include <sys/sockio.h> 61 #include <sys/sysctl.h> 62 #include <sys/systm.h> 63 #include <sys/thread2.h> 64 65 #include <net/ethernet.h> 66 #include <net/if.h> 67 #include <net/if_types.h> 68 #include <net/ifq_var.h> 69 #include <net/route.h> 70 #include <net/if_clone.h> 71 #include <net/netmsg2.h> 72 #include <net/netisr2.h> 73 74 #ifdef INET 75 #include <netinet/in.h> 76 #include <netinet/in_systm.h> 77 #include <netinet/in_var.h> 78 #include <netinet/ip.h> 79 #include <netinet/ip_gre.h> 80 #include <netinet/ip_var.h> 81 #include <netinet/ip_encap.h> 82 #else 83 #error "Huh? if_gre without inet?" 84 #endif 85 86 #include <net/bpf.h> 87 88 #include <net/net_osdep.h> 89 #include "if_gre.h" 90 91 /* 92 * It is not easy to calculate the right value for a GRE MTU. 93 * We leave this task to the admin and use the same default that 94 * other vendors use. 95 */ 96 #define GREMTU 1476 97 98 #define GRENAME "gre" 99 100 static MALLOC_DEFINE(M_GRE, GRENAME, "Generic Routing Encapsulation"); 101 102 struct gre_softc_head gre_softc_list; 103 104 static int gre_clone_create(struct if_clone *, int, caddr_t, caddr_t); 105 static int gre_clone_destroy(struct ifnet *); 106 static int gre_ioctl(struct ifnet *, u_long, caddr_t, struct ucred *); 107 static int gre_output(struct ifnet *, struct mbuf *, struct sockaddr *, 108 struct rtentry *rt); 109 110 static struct if_clone gre_cloner = IF_CLONE_INITIALIZER("gre", 111 gre_clone_create, gre_clone_destroy, 0, IF_MAXUNIT); 112 113 static int gre_compute_route(struct gre_softc *sc, struct route *); 114 static int gre_check_route(struct gre_softc *sc); 115 116 static void greattach(void); 117 118 #ifdef INET 119 120 extern struct domain inetdomain; 121 122 static const struct protosw in_gre_protosw = 123 { 124 .pr_type = SOCK_RAW, 125 .pr_domain = &inetdomain, 126 .pr_protocol = IPPROTO_GRE, 127 .pr_flags = PR_ATOMIC|PR_ADDR, 128 129 .pr_input = gre_input, 130 .pr_output = rip_output, 131 .pr_ctlinput = NULL, 132 .pr_ctloutput = rip_ctloutput, 133 134 .pr_ctlport = NULL, 135 .pr_usrreqs = &rip_usrreqs 136 }; 137 138 static const struct protosw in_mobile_protosw = 139 { 140 .pr_type = SOCK_RAW, 141 .pr_domain = &inetdomain, 142 .pr_protocol = IPPROTO_MOBILE, 143 .pr_flags = PR_ATOMIC|PR_ADDR, 144 145 .pr_input = gre_mobile_input, 146 .pr_output = rip_output, 147 .pr_ctlinput = NULL, 148 .pr_ctloutput = rip_ctloutput, 149 150 .pr_ctlport = NULL, 151 .pr_usrreqs = &rip_usrreqs 152 }; 153 154 #endif 155 156 SYSCTL_DECL(_net_link); 157 SYSCTL_NODE(_net_link, IFT_OTHER, gre, CTLFLAG_RW, 0, 158 "Generic Routing Encapsulation"); 159 #ifndef MAX_GRE_NEST 160 /* 161 * This macro controls the default upper limitation on nesting of gre tunnels. 162 * Since, setting a large value to this macro with a careless configuration 163 * may introduce system crash, we don't allow any nestings by default. 164 * If you need to configure nested gre tunnels, you can define this macro 165 * in your kernel configuration file. However, if you do so, please be 166 * careful to configure the tunnels so that it won't make a loop. 167 */ 168 #define MAX_GRE_NEST 1 169 #endif 170 static int max_gre_nesting = MAX_GRE_NEST; 171 SYSCTL_INT(_net_link_gre, OID_AUTO, max_nesting, CTLFLAG_RW, 172 &max_gre_nesting, 0, "Max nested tunnels"); 173 174 /* ARGSUSED */ 175 static void 176 greattach(void) 177 { 178 179 LIST_INIT(&gre_softc_list); 180 if_clone_attach(&gre_cloner); 181 } 182 183 static int 184 gre_clone_create(struct if_clone *ifc, int unit, 185 caddr_t params __unused, caddr_t data __unused) 186 { 187 struct gre_softc *sc; 188 189 sc = kmalloc(sizeof(struct gre_softc), M_GRE, M_WAITOK); 190 memset(sc, 0, sizeof(struct gre_softc)); 191 192 sc->sc_if.if_softc = sc; 193 if_initname(&(sc->sc_if), GRENAME, unit); 194 ifq_set_maxlen(&sc->sc_if.if_snd, IFQ_MAXLEN); 195 sc->sc_if.if_type = IFT_OTHER; 196 sc->sc_if.if_addrlen = 0; 197 sc->sc_if.if_hdrlen = 24; /* IP + GRE */ 198 sc->sc_if.if_mtu = GREMTU; 199 sc->sc_if.if_flags = IFF_POINTOPOINT|IFF_MULTICAST; 200 sc->sc_if.if_output = gre_output; 201 sc->sc_if.if_ioctl = gre_ioctl; 202 sc->g_dst.s_addr = sc->g_src.s_addr = INADDR_ANY; 203 sc->g_proto = IPPROTO_GRE; 204 sc->sc_if.if_flags |= IFF_LINK0; 205 sc->encap = NULL; 206 sc->route_pcpu = kmalloc(netisr_ncpus * sizeof(struct route), M_GRE, 207 M_WAITOK | M_ZERO); 208 if_attach(&sc->sc_if, NULL); 209 bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int32_t)); 210 LIST_INSERT_HEAD(&gre_softc_list, sc, sc_list); 211 return (0); 212 } 213 214 static int 215 gre_clone_destroy(struct ifnet *ifp) 216 { 217 struct gre_softc *sc = ifp->if_softc; 218 int cpu; 219 220 #ifdef INET 221 if (sc->encap != NULL) 222 encap_detach(sc->encap); 223 #endif 224 LIST_REMOVE(sc, sc_list); 225 bpfdetach(ifp); 226 if_detach(ifp); 227 228 for (cpu = 0; cpu < netisr_ncpus; ++cpu) { 229 if (sc->route_pcpu[cpu].ro_rt != NULL) { 230 rtfree_async(sc->route_pcpu[cpu].ro_rt); 231 sc->route_pcpu[cpu].ro_rt = NULL; 232 } 233 } 234 kfree(sc->route_pcpu, M_GRE); 235 kfree(sc, M_GRE); 236 237 return 0; 238 } 239 240 /* 241 * The output routine. Takes a packet and encapsulates it in the protocol 242 * given by sc->g_proto. See also RFC 1701 and RFC 2004 243 */ 244 static int 245 gre_output_serialized(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 246 struct rtentry *rt) 247 { 248 int error = 0; 249 struct gre_softc *sc = ifp->if_softc; 250 struct greip *gh; 251 struct ip *ip; 252 u_short etype = 0; 253 struct mobile_h mob_h; 254 struct route *ro; 255 struct sockaddr_in *ro_dst; 256 257 ASSERT_NETISR_NCPUS(mycpuid); 258 259 /* 260 * gre may cause infinite recursion calls when misconfigured. 261 * We'll prevent this by introducing upper limit. 262 */ 263 if (++m->m_pkthdr.loop_cnt > max_gre_nesting) { 264 kprintf("%s: gre_output: packet looped too many times (%d)\n", 265 if_name(&sc->sc_if), m->m_pkthdr.loop_cnt); 266 m_freem(m); 267 error = ELOOP; 268 goto end; 269 } 270 271 if ((ifp->if_flags & (IFF_UP | IFF_RUNNING)) == 0 || 272 sc->g_src.s_addr == INADDR_ANY || sc->g_dst.s_addr == INADDR_ANY) { 273 m_freem(m); 274 error = ENETDOWN; 275 goto end; 276 } 277 278 ro = &sc->route_pcpu[mycpuid]; 279 ro_dst = (struct sockaddr_in *)&ro->ro_dst; 280 if (ro->ro_rt != NULL && 281 ((ro->ro_rt->rt_flags & RTF_UP) == 0 || 282 ro_dst->sin_addr.s_addr != sc->g_dst.s_addr)) { 283 RTFREE(ro->ro_rt); 284 ro->ro_rt = NULL; 285 } 286 if (ro->ro_rt == NULL) { 287 error = gre_compute_route(sc, ro); 288 if (error) { 289 m_freem(m); 290 goto end; 291 } 292 } 293 294 gh = NULL; 295 ip = NULL; 296 297 if (ifp->if_bpf) { 298 bpf_gettoken(); 299 if (ifp->if_bpf) { 300 uint32_t af = dst->sa_family; 301 302 bpf_ptap(ifp->if_bpf, m, &af, sizeof(af)); 303 } 304 bpf_reltoken(); 305 } 306 307 m->m_flags &= ~(M_BCAST|M_MCAST); 308 309 if (sc->g_proto == IPPROTO_MOBILE) { 310 if (dst->sa_family == AF_INET) { 311 struct mbuf *m0; 312 int msiz; 313 314 ip = mtod(m, struct ip *); 315 316 /* 317 * RFC2004 specifies that fragmented datagrams shouldn't 318 * be encapsulated. 319 */ 320 if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) { 321 m_freem(m); 322 error = EINVAL; /* is there better errno? */ 323 goto end; 324 } 325 memset(&mob_h, 0, MOB_H_SIZ_L); 326 mob_h.proto = (ip->ip_p) << 8; 327 mob_h.odst = ip->ip_dst.s_addr; 328 ip->ip_dst.s_addr = sc->g_dst.s_addr; 329 330 /* 331 * If the packet comes from our host, we only change 332 * the destination address in the IP header. 333 * Else we also need to save and change the source 334 */ 335 if (in_hosteq(ip->ip_src, sc->g_src)) { 336 msiz = MOB_H_SIZ_S; 337 } else { 338 mob_h.proto |= MOB_H_SBIT; 339 mob_h.osrc = ip->ip_src.s_addr; 340 ip->ip_src.s_addr = sc->g_src.s_addr; 341 msiz = MOB_H_SIZ_L; 342 } 343 mob_h.proto = htons(mob_h.proto); 344 mob_h.hcrc = gre_in_cksum((u_short *)&mob_h, msiz); 345 346 if ((m->m_data - msiz) < m->m_pktdat) { 347 /* need new mbuf */ 348 MGETHDR(m0, M_NOWAIT, MT_HEADER); 349 if (m0 == NULL) { 350 m_freem(m); 351 error = ENOBUFS; 352 goto end; 353 } 354 m0->m_next = m; 355 m->m_data += sizeof(struct ip); 356 m->m_len -= sizeof(struct ip); 357 m0->m_pkthdr.len = m->m_pkthdr.len + msiz; 358 m0->m_len = msiz + sizeof(struct ip); 359 m0->m_data += max_linkhdr; 360 memcpy(mtod(m0, caddr_t), (caddr_t)ip, 361 sizeof(struct ip)); 362 m = m0; 363 } else { /* we have some space left in the old one */ 364 m->m_data -= msiz; 365 m->m_len += msiz; 366 m->m_pkthdr.len += msiz; 367 bcopy(ip, mtod(m, caddr_t), 368 sizeof(struct ip)); 369 } 370 ip = mtod(m, struct ip *); 371 memcpy((caddr_t)(ip + 1), &mob_h, (unsigned)msiz); 372 ip->ip_len = htons(ntohs(ip->ip_len) + msiz); 373 } else { /* AF_INET */ 374 m_freem(m); 375 error = EINVAL; 376 goto end; 377 } 378 } else if (sc->g_proto == IPPROTO_GRE) { 379 switch (dst->sa_family) { 380 case AF_INET: 381 ip = mtod(m, struct ip *); 382 etype = ETHERTYPE_IP; 383 break; 384 default: 385 m_freem(m); 386 error = EAFNOSUPPORT; 387 goto end; 388 } 389 M_PREPEND(m, sizeof(struct greip), M_NOWAIT); 390 } else { 391 m_freem(m); 392 error = EINVAL; 393 goto end; 394 } 395 396 if (m == NULL) { /* impossible */ 397 error = ENOBUFS; 398 goto end; 399 } 400 401 gh = mtod(m, struct greip *); 402 if (sc->g_proto == IPPROTO_GRE) { 403 /* we don't have any GRE flags for now */ 404 405 memset((void *)&gh->gi_g, 0, sizeof(struct gre_h)); 406 gh->gi_ptype = htons(etype); 407 } 408 409 gh->gi_pr = sc->g_proto; 410 if (sc->g_proto != IPPROTO_MOBILE) { 411 gh->gi_src = sc->g_src; 412 gh->gi_dst = sc->g_dst; 413 ((struct ip*)gh)->ip_hl = (sizeof(struct ip)) >> 2; 414 ((struct ip*)gh)->ip_ttl = GRE_TTL; 415 ((struct ip*)gh)->ip_tos = ip->ip_tos; 416 ((struct ip*)gh)->ip_id = ip->ip_id; 417 gh->gi_len = htons(m->m_pkthdr.len); 418 } 419 420 IFNET_STAT_INC(ifp, opackets, 1); 421 IFNET_STAT_INC(ifp, obytes, m->m_pkthdr.len); 422 /* send it off */ 423 error = ip_output(m, NULL, ro, IP_DEBUGROUTE, NULL, NULL); 424 end: 425 if (error) 426 IFNET_STAT_INC(ifp, oerrors, 1); 427 return (error); 428 } 429 430 static int 431 gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 432 struct rtentry *rt) 433 { 434 struct ifaltq_subque *ifsq = ifq_get_subq_default(&ifp->if_snd); 435 int error; 436 437 ifsq_serialize_hw(ifsq); 438 error = gre_output_serialized(ifp, m, dst, rt); 439 ifsq_deserialize_hw(ifsq); 440 441 return error; 442 } 443 444 static int 445 gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr) 446 { 447 struct ifreq *ifr = (struct ifreq *)data; 448 struct if_laddrreq *lifr = (struct if_laddrreq *)data; 449 struct in_aliasreq *aifr = (struct in_aliasreq *)data; 450 struct gre_softc *sc = ifp->if_softc; 451 struct sockaddr_in si; 452 struct sockaddr *sa = NULL; 453 int error; 454 struct sockaddr_in sp, sm, dp, dm; 455 456 error = 0; 457 458 crit_enter(); 459 switch (cmd) { 460 case SIOCSIFADDR: 461 ifp->if_flags |= IFF_UP; 462 break; 463 case SIOCSIFDSTADDR: 464 break; 465 case SIOCSIFFLAGS: 466 error = caps_priv_check(cr, SYSCAP_RESTRICTEDROOT | 467 __SYSCAP_NULLCRED); 468 if (error) 469 break; 470 if ((ifr->ifr_flags & IFF_LINK0) != 0) 471 sc->g_proto = IPPROTO_GRE; 472 else 473 sc->g_proto = IPPROTO_MOBILE; 474 goto recompute; 475 case SIOCSIFMTU: 476 error = caps_priv_check(cr, SYSCAP_RESTRICTEDROOT | 477 __SYSCAP_NULLCRED); 478 if (error) 479 break; 480 if (ifr->ifr_mtu < 576) { 481 error = EINVAL; 482 break; 483 } 484 ifp->if_mtu = ifr->ifr_mtu; 485 break; 486 case SIOCGIFMTU: 487 ifr->ifr_mtu = sc->sc_if.if_mtu; 488 break; 489 case SIOCADDMULTI: 490 case SIOCDELMULTI: 491 error = caps_priv_check(cr, SYSCAP_RESTRICTEDROOT | 492 __SYSCAP_NULLCRED); 493 if (error) 494 break; 495 if (ifr == NULL) { 496 error = EAFNOSUPPORT; 497 break; 498 } 499 switch (ifr->ifr_addr.sa_family) { 500 #ifdef INET 501 case AF_INET: 502 break; 503 #endif 504 default: 505 error = EAFNOSUPPORT; 506 break; 507 } 508 break; 509 case GRESPROTO: 510 error = caps_priv_check(cr, SYSCAP_RESTRICTEDROOT | 511 __SYSCAP_NULLCRED); 512 if (error) 513 break; 514 sc->g_proto = ifr->ifr_flags; 515 switch (sc->g_proto) { 516 case IPPROTO_GRE: 517 ifp->if_flags |= IFF_LINK0; 518 break; 519 case IPPROTO_MOBILE: 520 ifp->if_flags &= ~IFF_LINK0; 521 break; 522 default: 523 error = EPROTONOSUPPORT; 524 break; 525 } 526 goto recompute; 527 case GREGPROTO: 528 ifr->ifr_flags = sc->g_proto; 529 break; 530 case GRESADDRS: 531 case GRESADDRD: 532 error = caps_priv_check(cr, SYSCAP_RESTRICTEDROOT | 533 __SYSCAP_NULLCRED); 534 if (error) 535 break; 536 /* 537 * set tunnel endpoints, compute a less specific route 538 * to the remote end and mark if as up 539 */ 540 sa = &ifr->ifr_addr; 541 if (cmd == GRESADDRS) 542 sc->g_src = (satosin(sa))->sin_addr; 543 if (cmd == GRESADDRD) 544 sc->g_dst = (satosin(sa))->sin_addr; 545 recompute: 546 #ifdef INET 547 if (sc->encap != NULL) { 548 encap_detach(sc->encap); 549 sc->encap = NULL; 550 } 551 #endif 552 if ((sc->g_src.s_addr != INADDR_ANY) && 553 (sc->g_dst.s_addr != INADDR_ANY)) { 554 bzero(&sp, sizeof(sp)); 555 bzero(&sm, sizeof(sm)); 556 bzero(&dp, sizeof(dp)); 557 bzero(&dm, sizeof(dm)); 558 sp.sin_len = sm.sin_len = dp.sin_len = dm.sin_len = 559 sizeof(struct sockaddr_in); 560 sp.sin_family = sm.sin_family = dp.sin_family = 561 dm.sin_family = AF_INET; 562 sp.sin_addr = sc->g_src; 563 dp.sin_addr = sc->g_dst; 564 sm.sin_addr.s_addr = dm.sin_addr.s_addr = 565 INADDR_BROADCAST; 566 #ifdef INET 567 sc->encap = encap_attach(AF_INET, sc->g_proto, 568 sintosa(&sp), sintosa(&sm), sintosa(&dp), 569 sintosa(&dm), (sc->g_proto == IPPROTO_GRE) ? 570 &in_gre_protosw : &in_mobile_protosw, sc); 571 if (sc->encap == NULL) 572 kprintf("%s: unable to attach encap\n", 573 if_name(&sc->sc_if)); 574 #endif 575 ifnet_deserialize_all(ifp); 576 error = gre_check_route(sc); 577 ifnet_serialize_all(ifp); 578 if (!error) 579 ifp->if_flags |= IFF_RUNNING; 580 else 581 ifp->if_flags &= ~IFF_RUNNING; 582 } 583 break; 584 case GREGADDRS: 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_src.s_addr; 589 sa = sintosa(&si); 590 ifr->ifr_addr = *sa; 591 break; 592 case GREGADDRD: 593 memset(&si, 0, sizeof(si)); 594 si.sin_family = AF_INET; 595 si.sin_len = sizeof(struct sockaddr_in); 596 si.sin_addr.s_addr = sc->g_dst.s_addr; 597 sa = sintosa(&si); 598 ifr->ifr_addr = *sa; 599 break; 600 case SIOCSIFPHYADDR: 601 error = caps_priv_check(cr, SYSCAP_RESTRICTEDROOT | 602 __SYSCAP_NULLCRED); 603 if (error) 604 break; 605 if (aifr->ifra_addr.sin_family != AF_INET || 606 aifr->ifra_dstaddr.sin_family != AF_INET) 607 { 608 error = EAFNOSUPPORT; 609 break; 610 } 611 if (aifr->ifra_addr.sin_len != sizeof(si) || 612 aifr->ifra_dstaddr.sin_len != sizeof(si)) 613 { 614 error = EINVAL; 615 break; 616 } 617 sc->g_src = aifr->ifra_addr.sin_addr; 618 sc->g_dst = aifr->ifra_dstaddr.sin_addr; 619 goto recompute; 620 case SIOCSLIFPHYADDR: 621 error = caps_priv_check(cr, SYSCAP_RESTRICTEDROOT | 622 __SYSCAP_NULLCRED); 623 if (error) 624 break; 625 if (lifr->addr.ss_family != AF_INET || 626 lifr->dstaddr.ss_family != AF_INET) { 627 error = EAFNOSUPPORT; 628 break; 629 } 630 if (lifr->addr.ss_len != sizeof(si) || 631 lifr->dstaddr.ss_len != sizeof(si)) { 632 error = EINVAL; 633 break; 634 } 635 sc->g_src = (satosin((struct sockadrr *)&lifr->addr))->sin_addr; 636 sc->g_dst = 637 (satosin((struct sockadrr *)&lifr->dstaddr))->sin_addr; 638 goto recompute; 639 case SIOCDIFPHYADDR: 640 error = caps_priv_check(cr, SYSCAP_RESTRICTEDROOT | 641 __SYSCAP_NULLCRED); 642 if (error) 643 break; 644 sc->g_src.s_addr = INADDR_ANY; 645 sc->g_dst.s_addr = INADDR_ANY; 646 goto recompute; 647 case SIOCGLIFPHYADDR: 648 if (sc->g_src.s_addr == INADDR_ANY || 649 sc->g_dst.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 memcpy(&lifr->addr, &si, sizeof(si)); 658 si.sin_addr.s_addr = sc->g_dst.s_addr; 659 memcpy(&lifr->dstaddr, &si, sizeof(si)); 660 break; 661 case SIOCGIFPSRCADDR: 662 if (sc->g_src.s_addr == INADDR_ANY) { 663 error = EADDRNOTAVAIL; 664 break; 665 } 666 memset(&si, 0, sizeof(si)); 667 si.sin_family = AF_INET; 668 si.sin_len = sizeof(struct sockaddr_in); 669 si.sin_addr.s_addr = sc->g_src.s_addr; 670 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr)); 671 break; 672 case SIOCGIFPDSTADDR: 673 if (sc->g_dst.s_addr == INADDR_ANY) { 674 error = EADDRNOTAVAIL; 675 break; 676 } 677 memset(&si, 0, sizeof(si)); 678 si.sin_family = AF_INET; 679 si.sin_len = sizeof(struct sockaddr_in); 680 si.sin_addr.s_addr = sc->g_dst.s_addr; 681 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr)); 682 break; 683 default: 684 error = EINVAL; 685 break; 686 } 687 688 crit_exit(); 689 return (error); 690 } 691 692 /* 693 * computes a route to our destination that is not the one 694 * which would be taken by ip_output(), as this one will loop back to 695 * us. If the interface is p2p as a--->b, then a routing entry exists 696 * If we now send a packet to b (e.g. ping b), this will come down here 697 * gets src=a, dst=b tacked on and would from ip_ouput() sent back to 698 * if_gre. 699 * Goal here is to compute a route to b that is less specific than 700 * a-->b. We know that this one exists as in normal operation we have 701 * at least a default route which matches. 702 */ 703 static int 704 gre_compute_route(struct gre_softc *sc, struct route *ro) 705 { 706 #ifdef DIAGNOSTIC 707 char abuf[INET_ADDRSTRLEN]; 708 #endif 709 u_int32_t a, b, c; 710 711 ASSERT_NETISR_NCPUS(mycpuid); 712 KASSERT(ro == &sc->route_pcpu[mycpuid], ("route mismatch")); 713 KASSERT(ro->ro_rt == NULL, ("rtentry not freed")); 714 715 memset(ro, 0, sizeof(struct route)); 716 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst; 717 ro->ro_dst.sa_family = AF_INET; 718 ro->ro_dst.sa_len = sizeof(ro->ro_dst); 719 720 /* 721 * toggle last bit, so our interface is not found, but a less 722 * specific route. I'd rather like to specify a shorter mask, 723 * but this is not possible. Should work though. XXX 724 * there is a simpler way ... 725 */ 726 if ((sc->sc_if.if_flags & IFF_LINK1) == 0) { 727 a = ntohl(sc->g_dst.s_addr); 728 b = a & 0x01; 729 c = a & 0xfffffffe; 730 b = b ^ 0x01; 731 a = b | c; 732 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr.s_addr 733 = htonl(a); 734 } 735 736 #ifdef DIAGNOSTIC 737 kprintf("%s: searching a route to %s", if_name(&sc->sc_if), 738 kinet_ntoa(((struct sockaddr_in *)&ro->ro_dst)->sin_addr, abuf)); 739 #endif 740 741 rtalloc(ro); 742 743 /* 744 * check if this returned a route at all and this route is no 745 * recursion to ourself 746 */ 747 if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp->if_softc == sc) { 748 #ifdef DIAGNOSTIC 749 if (ro->ro_rt == NULL) 750 kprintf(" - no route found!\n"); 751 else 752 kprintf(" - route loops back to ourself!\n"); 753 #endif 754 return EADDRNOTAVAIL; 755 } 756 757 /* 758 * now change it back - else ip_output will just drop 759 * the route and search one to this interface ... 760 */ 761 if ((sc->sc_if.if_flags & IFF_LINK1) == 0) 762 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst; 763 764 #ifdef DIAGNOSTIC 765 kprintf(", choosing %s with gateway %s", if_name(ro->ro_rt->rt_ifp), 766 kinet_ntoa( 767 ((struct sockaddr_in *)(ro->ro_rt->rt_gateway))->sin_addr, abuf)); 768 kprintf("\n"); 769 #endif 770 771 return 0; 772 } 773 774 static void 775 gre_check_route_handler(netmsg_t msg) 776 { 777 struct gre_softc *sc = msg->base.lmsg.u.ms_resultp; 778 struct route *ro; 779 int error; 780 781 ASSERT_NETISR0; 782 783 ro = &sc->route_pcpu[mycpuid]; 784 if (ro->ro_rt != NULL) { 785 RTFREE(ro->ro_rt); 786 ro->ro_rt = NULL; 787 } 788 error = gre_compute_route(sc, ro); 789 790 netisr_replymsg(&msg->base, error); 791 } 792 793 static int 794 gre_check_route(struct gre_softc *sc) 795 { 796 struct netmsg_base msg; 797 798 netmsg_init(&msg, NULL, &curthread->td_msgport, MSGF_PRIORITY, 799 gre_check_route_handler); 800 msg.lmsg.u.ms_resultp = sc; 801 802 return (netisr_domsg(&msg, 0)); 803 } 804 805 /* 806 * do a checksum of a buffer - much like in_cksum, which operates on 807 * mbufs. 808 */ 809 u_short 810 gre_in_cksum(u_short *p, u_int len) 811 { 812 u_int sum = 0; 813 int nwords = len >> 1; 814 815 while (nwords-- != 0) 816 sum += *p++; 817 818 if (len & 1) { 819 union { 820 u_short w; 821 u_char c[2]; 822 } u; 823 u.c[0] = *(u_char *)p; 824 u.c[1] = 0; 825 sum += u.w; 826 } 827 828 /* end-around-carry */ 829 sum = (sum >> 16) + (sum & 0xffff); 830 sum += (sum >> 16); 831 return (~sum); 832 } 833 834 static int 835 gremodevent(module_t mod, int type, void *data) 836 { 837 838 switch (type) { 839 case MOD_LOAD: 840 greattach(); 841 break; 842 case MOD_UNLOAD: 843 if_clone_detach(&gre_cloner); 844 845 while (!LIST_EMPTY(&gre_softc_list)) 846 gre_clone_destroy(&LIST_FIRST(&gre_softc_list)->sc_if); 847 848 break; 849 } 850 return 0; 851 } 852 853 static moduledata_t gre_mod = { 854 "if_gre", 855 gremodevent, 856 0 857 }; 858 859 DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 860 MODULE_VERSION(if_gre, 1); 861