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->called = 0; 207 sc->route_pcpu = kmalloc(netisr_ncpus * sizeof(struct route), M_GRE, 208 M_WAITOK | M_ZERO); 209 if_attach(&sc->sc_if, NULL); 210 bpfattach(&sc->sc_if, DLT_NULL, sizeof(u_int32_t)); 211 LIST_INSERT_HEAD(&gre_softc_list, sc, sc_list); 212 return (0); 213 } 214 215 static int 216 gre_clone_destroy(struct ifnet *ifp) 217 { 218 struct gre_softc *sc = ifp->if_softc; 219 int cpu; 220 221 #ifdef INET 222 if (sc->encap != NULL) 223 encap_detach(sc->encap); 224 #endif 225 LIST_REMOVE(sc, sc_list); 226 bpfdetach(ifp); 227 if_detach(ifp); 228 229 for (cpu = 0; cpu < netisr_ncpus; ++cpu) { 230 if (sc->route_pcpu[cpu].ro_rt != NULL) { 231 rtfree_async(sc->route_pcpu[cpu].ro_rt); 232 sc->route_pcpu[cpu].ro_rt = NULL; 233 } 234 } 235 kfree(sc->route_pcpu, M_GRE); 236 kfree(sc, M_GRE); 237 238 return 0; 239 } 240 241 /* 242 * The output routine. Takes a packet and encapsulates it in the protocol 243 * given by sc->g_proto. See also RFC 1701 and RFC 2004 244 */ 245 static int 246 gre_output_serialized(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 247 struct rtentry *rt) 248 { 249 int error = 0; 250 struct gre_softc *sc = ifp->if_softc; 251 struct greip *gh; 252 struct ip *ip; 253 u_short etype = 0; 254 struct mobile_h mob_h; 255 struct route *ro; 256 struct sockaddr_in *ro_dst; 257 258 ASSERT_NETISR_NCPUS(mycpuid); 259 260 /* 261 * gre may cause infinite recursion calls when misconfigured. 262 * We'll prevent this by introducing upper limit. 263 */ 264 if (++(sc->called) > max_gre_nesting) { 265 kprintf("%s: gre_output: recursively called too many " 266 "times(%d)\n", if_name(&sc->sc_if), sc->called); 267 m_freem(m); 268 error = EIO; /* is there better errno? */ 269 goto end; 270 } 271 272 if ((ifp->if_flags & (IFF_UP | IFF_RUNNING)) == 0 || 273 sc->g_src.s_addr == INADDR_ANY || sc->g_dst.s_addr == INADDR_ANY) { 274 m_freem(m); 275 error = ENETDOWN; 276 goto end; 277 } 278 279 ro = &sc->route_pcpu[mycpuid]; 280 ro_dst = (struct sockaddr_in *)&ro->ro_dst; 281 if (ro->ro_rt != NULL && 282 ((ro->ro_rt->rt_flags & RTF_UP) == 0 || 283 ro_dst->sin_addr.s_addr != sc->g_dst.s_addr)) { 284 RTFREE(ro->ro_rt); 285 ro->ro_rt = NULL; 286 } 287 if (ro->ro_rt == NULL) { 288 error = gre_compute_route(sc, ro); 289 if (error) { 290 m_freem(m); 291 goto end; 292 } 293 } 294 295 gh = NULL; 296 ip = NULL; 297 298 if (ifp->if_bpf) { 299 bpf_gettoken(); 300 if (ifp->if_bpf) { 301 uint32_t af = dst->sa_family; 302 303 bpf_ptap(ifp->if_bpf, m, &af, sizeof(af)); 304 } 305 bpf_reltoken(); 306 } 307 308 m->m_flags &= ~(M_BCAST|M_MCAST); 309 310 if (sc->g_proto == IPPROTO_MOBILE) { 311 if (dst->sa_family == AF_INET) { 312 struct mbuf *m0; 313 int msiz; 314 315 ip = mtod(m, struct ip *); 316 317 /* 318 * RFC2004 specifies that fragmented datagrams shouldn't 319 * be encapsulated. 320 */ 321 if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) { 322 m_freem(m); 323 error = EINVAL; /* is there better errno? */ 324 goto end; 325 } 326 memset(&mob_h, 0, MOB_H_SIZ_L); 327 mob_h.proto = (ip->ip_p) << 8; 328 mob_h.odst = ip->ip_dst.s_addr; 329 ip->ip_dst.s_addr = sc->g_dst.s_addr; 330 331 /* 332 * If the packet comes from our host, we only change 333 * the destination address in the IP header. 334 * Else we also need to save and change the source 335 */ 336 if (in_hosteq(ip->ip_src, sc->g_src)) { 337 msiz = MOB_H_SIZ_S; 338 } else { 339 mob_h.proto |= MOB_H_SBIT; 340 mob_h.osrc = ip->ip_src.s_addr; 341 ip->ip_src.s_addr = sc->g_src.s_addr; 342 msiz = MOB_H_SIZ_L; 343 } 344 mob_h.proto = htons(mob_h.proto); 345 mob_h.hcrc = gre_in_cksum((u_short *)&mob_h, msiz); 346 347 if ((m->m_data - msiz) < m->m_pktdat) { 348 /* need new mbuf */ 349 MGETHDR(m0, M_NOWAIT, MT_HEADER); 350 if (m0 == NULL) { 351 m_freem(m); 352 error = ENOBUFS; 353 goto end; 354 } 355 m0->m_next = m; 356 m->m_data += sizeof(struct ip); 357 m->m_len -= sizeof(struct ip); 358 m0->m_pkthdr.len = m->m_pkthdr.len + msiz; 359 m0->m_len = msiz + sizeof(struct ip); 360 m0->m_data += max_linkhdr; 361 memcpy(mtod(m0, caddr_t), (caddr_t)ip, 362 sizeof(struct ip)); 363 m = m0; 364 } else { /* we have some space left in the old one */ 365 m->m_data -= msiz; 366 m->m_len += msiz; 367 m->m_pkthdr.len += msiz; 368 bcopy(ip, mtod(m, caddr_t), 369 sizeof(struct ip)); 370 } 371 ip = mtod(m, struct ip *); 372 memcpy((caddr_t)(ip + 1), &mob_h, (unsigned)msiz); 373 ip->ip_len = htons(ntohs(ip->ip_len) + msiz); 374 } else { /* AF_INET */ 375 m_freem(m); 376 error = EINVAL; 377 goto end; 378 } 379 } else if (sc->g_proto == IPPROTO_GRE) { 380 switch (dst->sa_family) { 381 case AF_INET: 382 ip = mtod(m, struct ip *); 383 etype = ETHERTYPE_IP; 384 break; 385 default: 386 m_freem(m); 387 error = EAFNOSUPPORT; 388 goto end; 389 } 390 M_PREPEND(m, sizeof(struct greip), M_NOWAIT); 391 } else { 392 m_freem(m); 393 error = EINVAL; 394 goto end; 395 } 396 397 if (m == NULL) { /* impossible */ 398 error = ENOBUFS; 399 goto end; 400 } 401 402 gh = mtod(m, struct greip *); 403 if (sc->g_proto == IPPROTO_GRE) { 404 /* we don't have any GRE flags for now */ 405 406 memset((void *)&gh->gi_g, 0, sizeof(struct gre_h)); 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_hl = (sizeof(struct ip)) >> 2; 415 ((struct ip*)gh)->ip_ttl = GRE_TTL; 416 ((struct ip*)gh)->ip_tos = ip->ip_tos; 417 ((struct ip*)gh)->ip_id = ip->ip_id; 418 gh->gi_len = htons(m->m_pkthdr.len); 419 } 420 421 IFNET_STAT_INC(ifp, opackets, 1); 422 IFNET_STAT_INC(ifp, obytes, m->m_pkthdr.len); 423 /* send it off */ 424 error = ip_output(m, NULL, ro, IP_DEBUGROUTE, NULL, NULL); 425 end: 426 sc->called = 0; 427 if (error) 428 IFNET_STAT_INC(ifp, oerrors, 1); 429 return (error); 430 } 431 432 static int 433 gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 434 struct rtentry *rt) 435 { 436 struct ifaltq_subque *ifsq = ifq_get_subq_default(&ifp->if_snd); 437 int error; 438 439 ifsq_serialize_hw(ifsq); 440 error = gre_output_serialized(ifp, m, dst, rt); 441 ifsq_deserialize_hw(ifsq); 442 443 return error; 444 } 445 446 static int 447 gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr) 448 { 449 struct ifreq *ifr = (struct ifreq *)data; 450 struct if_laddrreq *lifr = (struct if_laddrreq *)data; 451 struct in_aliasreq *aifr = (struct in_aliasreq *)data; 452 struct gre_softc *sc = ifp->if_softc; 453 struct sockaddr_in si; 454 struct sockaddr *sa = NULL; 455 int error; 456 struct sockaddr_in sp, sm, dp, dm; 457 458 error = 0; 459 460 crit_enter(); 461 switch (cmd) { 462 case SIOCSIFADDR: 463 ifp->if_flags |= IFF_UP; 464 break; 465 case SIOCSIFDSTADDR: 466 break; 467 case SIOCSIFFLAGS: 468 error = caps_priv_check(cr, SYSCAP_RESTRICTEDROOT | 469 __SYSCAP_NULLCRED); 470 if (error) 471 break; 472 if ((ifr->ifr_flags & IFF_LINK0) != 0) 473 sc->g_proto = IPPROTO_GRE; 474 else 475 sc->g_proto = IPPROTO_MOBILE; 476 goto recompute; 477 case SIOCSIFMTU: 478 error = caps_priv_check(cr, SYSCAP_RESTRICTEDROOT | 479 __SYSCAP_NULLCRED); 480 if (error) 481 break; 482 if (ifr->ifr_mtu < 576) { 483 error = EINVAL; 484 break; 485 } 486 ifp->if_mtu = ifr->ifr_mtu; 487 break; 488 case SIOCGIFMTU: 489 ifr->ifr_mtu = sc->sc_if.if_mtu; 490 break; 491 case SIOCADDMULTI: 492 case SIOCDELMULTI: 493 error = caps_priv_check(cr, SYSCAP_RESTRICTEDROOT | 494 __SYSCAP_NULLCRED); 495 if (error) 496 break; 497 if (ifr == NULL) { 498 error = EAFNOSUPPORT; 499 break; 500 } 501 switch (ifr->ifr_addr.sa_family) { 502 #ifdef INET 503 case AF_INET: 504 break; 505 #endif 506 default: 507 error = EAFNOSUPPORT; 508 break; 509 } 510 break; 511 case GRESPROTO: 512 error = caps_priv_check(cr, SYSCAP_RESTRICTEDROOT | 513 __SYSCAP_NULLCRED); 514 if (error) 515 break; 516 sc->g_proto = ifr->ifr_flags; 517 switch (sc->g_proto) { 518 case IPPROTO_GRE: 519 ifp->if_flags |= IFF_LINK0; 520 break; 521 case IPPROTO_MOBILE: 522 ifp->if_flags &= ~IFF_LINK0; 523 break; 524 default: 525 error = EPROTONOSUPPORT; 526 break; 527 } 528 goto recompute; 529 case GREGPROTO: 530 ifr->ifr_flags = sc->g_proto; 531 break; 532 case GRESADDRS: 533 case GRESADDRD: 534 error = caps_priv_check(cr, SYSCAP_RESTRICTEDROOT | 535 __SYSCAP_NULLCRED); 536 if (error) 537 break; 538 /* 539 * set tunnel endpoints, compute a less specific route 540 * to the remote end and mark if as up 541 */ 542 sa = &ifr->ifr_addr; 543 if (cmd == GRESADDRS) 544 sc->g_src = (satosin(sa))->sin_addr; 545 if (cmd == GRESADDRD) 546 sc->g_dst = (satosin(sa))->sin_addr; 547 recompute: 548 #ifdef INET 549 if (sc->encap != NULL) { 550 encap_detach(sc->encap); 551 sc->encap = NULL; 552 } 553 #endif 554 if ((sc->g_src.s_addr != INADDR_ANY) && 555 (sc->g_dst.s_addr != INADDR_ANY)) { 556 bzero(&sp, sizeof(sp)); 557 bzero(&sm, sizeof(sm)); 558 bzero(&dp, sizeof(dp)); 559 bzero(&dm, sizeof(dm)); 560 sp.sin_len = sm.sin_len = dp.sin_len = dm.sin_len = 561 sizeof(struct sockaddr_in); 562 sp.sin_family = sm.sin_family = dp.sin_family = 563 dm.sin_family = AF_INET; 564 sp.sin_addr = sc->g_src; 565 dp.sin_addr = sc->g_dst; 566 sm.sin_addr.s_addr = dm.sin_addr.s_addr = 567 INADDR_BROADCAST; 568 #ifdef INET 569 sc->encap = encap_attach(AF_INET, sc->g_proto, 570 sintosa(&sp), sintosa(&sm), sintosa(&dp), 571 sintosa(&dm), (sc->g_proto == IPPROTO_GRE) ? 572 &in_gre_protosw : &in_mobile_protosw, sc); 573 if (sc->encap == NULL) 574 kprintf("%s: unable to attach encap\n", 575 if_name(&sc->sc_if)); 576 #endif 577 ifnet_deserialize_all(ifp); 578 error = gre_check_route(sc); 579 ifnet_serialize_all(ifp); 580 if (!error) 581 ifp->if_flags |= IFF_RUNNING; 582 else 583 ifp->if_flags &= ~IFF_RUNNING; 584 } 585 break; 586 case GREGADDRS: 587 memset(&si, 0, sizeof(si)); 588 si.sin_family = AF_INET; 589 si.sin_len = sizeof(struct sockaddr_in); 590 si.sin_addr.s_addr = sc->g_src.s_addr; 591 sa = sintosa(&si); 592 ifr->ifr_addr = *sa; 593 break; 594 case GREGADDRD: 595 memset(&si, 0, sizeof(si)); 596 si.sin_family = AF_INET; 597 si.sin_len = sizeof(struct sockaddr_in); 598 si.sin_addr.s_addr = sc->g_dst.s_addr; 599 sa = sintosa(&si); 600 ifr->ifr_addr = *sa; 601 break; 602 case SIOCSIFPHYADDR: 603 error = caps_priv_check(cr, SYSCAP_RESTRICTEDROOT | 604 __SYSCAP_NULLCRED); 605 if (error) 606 break; 607 if (aifr->ifra_addr.sin_family != AF_INET || 608 aifr->ifra_dstaddr.sin_family != AF_INET) 609 { 610 error = EAFNOSUPPORT; 611 break; 612 } 613 if (aifr->ifra_addr.sin_len != sizeof(si) || 614 aifr->ifra_dstaddr.sin_len != sizeof(si)) 615 { 616 error = EINVAL; 617 break; 618 } 619 sc->g_src = aifr->ifra_addr.sin_addr; 620 sc->g_dst = aifr->ifra_dstaddr.sin_addr; 621 goto recompute; 622 case SIOCSLIFPHYADDR: 623 error = caps_priv_check(cr, SYSCAP_RESTRICTEDROOT | 624 __SYSCAP_NULLCRED); 625 if (error) 626 break; 627 if (lifr->addr.ss_family != AF_INET || 628 lifr->dstaddr.ss_family != AF_INET) { 629 error = EAFNOSUPPORT; 630 break; 631 } 632 if (lifr->addr.ss_len != sizeof(si) || 633 lifr->dstaddr.ss_len != sizeof(si)) { 634 error = EINVAL; 635 break; 636 } 637 sc->g_src = (satosin((struct sockadrr *)&lifr->addr))->sin_addr; 638 sc->g_dst = 639 (satosin((struct sockadrr *)&lifr->dstaddr))->sin_addr; 640 goto recompute; 641 case SIOCDIFPHYADDR: 642 error = caps_priv_check(cr, SYSCAP_RESTRICTEDROOT | 643 __SYSCAP_NULLCRED); 644 if (error) 645 break; 646 sc->g_src.s_addr = INADDR_ANY; 647 sc->g_dst.s_addr = INADDR_ANY; 648 goto recompute; 649 case SIOCGLIFPHYADDR: 650 if (sc->g_src.s_addr == INADDR_ANY || 651 sc->g_dst.s_addr == INADDR_ANY) { 652 error = EADDRNOTAVAIL; 653 break; 654 } 655 memset(&si, 0, sizeof(si)); 656 si.sin_family = AF_INET; 657 si.sin_len = sizeof(struct sockaddr_in); 658 si.sin_addr.s_addr = sc->g_src.s_addr; 659 memcpy(&lifr->addr, &si, sizeof(si)); 660 si.sin_addr.s_addr = sc->g_dst.s_addr; 661 memcpy(&lifr->dstaddr, &si, sizeof(si)); 662 break; 663 case SIOCGIFPSRCADDR: 664 if (sc->g_src.s_addr == INADDR_ANY) { 665 error = EADDRNOTAVAIL; 666 break; 667 } 668 memset(&si, 0, sizeof(si)); 669 si.sin_family = AF_INET; 670 si.sin_len = sizeof(struct sockaddr_in); 671 si.sin_addr.s_addr = sc->g_src.s_addr; 672 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr)); 673 break; 674 case SIOCGIFPDSTADDR: 675 if (sc->g_dst.s_addr == INADDR_ANY) { 676 error = EADDRNOTAVAIL; 677 break; 678 } 679 memset(&si, 0, sizeof(si)); 680 si.sin_family = AF_INET; 681 si.sin_len = sizeof(struct sockaddr_in); 682 si.sin_addr.s_addr = sc->g_dst.s_addr; 683 bcopy(&si, &ifr->ifr_addr, sizeof(ifr->ifr_addr)); 684 break; 685 default: 686 error = EINVAL; 687 break; 688 } 689 690 crit_exit(); 691 return (error); 692 } 693 694 /* 695 * computes a route to our destination that is not the one 696 * which would be taken by ip_output(), as this one will loop back to 697 * us. If the interface is p2p as a--->b, then a routing entry exists 698 * If we now send a packet to b (e.g. ping b), this will come down here 699 * gets src=a, dst=b tacked on and would from ip_ouput() sent back to 700 * if_gre. 701 * Goal here is to compute a route to b that is less specific than 702 * a-->b. We know that this one exists as in normal operation we have 703 * at least a default route which matches. 704 */ 705 static int 706 gre_compute_route(struct gre_softc *sc, struct route *ro) 707 { 708 #ifdef DIAGNOSTIC 709 char abuf[INET_ADDRSTRLEN]; 710 #endif 711 u_int32_t a, b, c; 712 713 ASSERT_NETISR_NCPUS(mycpuid); 714 KASSERT(ro == &sc->route_pcpu[mycpuid], ("route mismatch")); 715 KASSERT(ro->ro_rt == NULL, ("rtentry not freed")); 716 717 memset(ro, 0, sizeof(struct route)); 718 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst; 719 ro->ro_dst.sa_family = AF_INET; 720 ro->ro_dst.sa_len = sizeof(ro->ro_dst); 721 722 /* 723 * toggle last bit, so our interface is not found, but a less 724 * specific route. I'd rather like to specify a shorter mask, 725 * but this is not possible. Should work though. XXX 726 * there is a simpler way ... 727 */ 728 if ((sc->sc_if.if_flags & IFF_LINK1) == 0) { 729 a = ntohl(sc->g_dst.s_addr); 730 b = a & 0x01; 731 c = a & 0xfffffffe; 732 b = b ^ 0x01; 733 a = b | c; 734 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr.s_addr 735 = htonl(a); 736 } 737 738 #ifdef DIAGNOSTIC 739 kprintf("%s: searching a route to %s", if_name(&sc->sc_if), 740 kinet_ntoa(((struct sockaddr_in *)&ro->ro_dst)->sin_addr, abuf)); 741 #endif 742 743 rtalloc(ro); 744 745 /* 746 * check if this returned a route at all and this route is no 747 * recursion to ourself 748 */ 749 if (ro->ro_rt == NULL || ro->ro_rt->rt_ifp->if_softc == sc) { 750 #ifdef DIAGNOSTIC 751 if (ro->ro_rt == NULL) 752 kprintf(" - no route found!\n"); 753 else 754 kprintf(" - route loops back to ourself!\n"); 755 #endif 756 return EADDRNOTAVAIL; 757 } 758 759 /* 760 * now change it back - else ip_output will just drop 761 * the route and search one to this interface ... 762 */ 763 if ((sc->sc_if.if_flags & IFF_LINK1) == 0) 764 ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = sc->g_dst; 765 766 #ifdef DIAGNOSTIC 767 kprintf(", choosing %s with gateway %s", if_name(ro->ro_rt->rt_ifp), 768 kinet_ntoa( 769 ((struct sockaddr_in *)(ro->ro_rt->rt_gateway))->sin_addr, abuf)); 770 kprintf("\n"); 771 #endif 772 773 return 0; 774 } 775 776 static void 777 gre_check_route_handler(netmsg_t msg) 778 { 779 struct gre_softc *sc = msg->base.lmsg.u.ms_resultp; 780 struct route *ro; 781 int error; 782 783 ASSERT_NETISR0; 784 785 ro = &sc->route_pcpu[mycpuid]; 786 if (ro->ro_rt != NULL) { 787 RTFREE(ro->ro_rt); 788 ro->ro_rt = NULL; 789 } 790 error = gre_compute_route(sc, ro); 791 792 netisr_replymsg(&msg->base, error); 793 } 794 795 static int 796 gre_check_route(struct gre_softc *sc) 797 { 798 struct netmsg_base msg; 799 800 netmsg_init(&msg, NULL, &curthread->td_msgport, MSGF_PRIORITY, 801 gre_check_route_handler); 802 msg.lmsg.u.ms_resultp = sc; 803 804 return (netisr_domsg(&msg, 0)); 805 } 806 807 /* 808 * do a checksum of a buffer - much like in_cksum, which operates on 809 * mbufs. 810 */ 811 u_short 812 gre_in_cksum(u_short *p, u_int len) 813 { 814 u_int sum = 0; 815 int nwords = len >> 1; 816 817 while (nwords-- != 0) 818 sum += *p++; 819 820 if (len & 1) { 821 union { 822 u_short w; 823 u_char c[2]; 824 } u; 825 u.c[0] = *(u_char *)p; 826 u.c[1] = 0; 827 sum += u.w; 828 } 829 830 /* end-around-carry */ 831 sum = (sum >> 16) + (sum & 0xffff); 832 sum += (sum >> 16); 833 return (~sum); 834 } 835 836 static int 837 gremodevent(module_t mod, int type, void *data) 838 { 839 840 switch (type) { 841 case MOD_LOAD: 842 greattach(); 843 break; 844 case MOD_UNLOAD: 845 if_clone_detach(&gre_cloner); 846 847 while (!LIST_EMPTY(&gre_softc_list)) 848 gre_clone_destroy(&LIST_FIRST(&gre_softc_list)->sc_if); 849 850 break; 851 } 852 return 0; 853 } 854 855 static moduledata_t gre_mod = { 856 "if_gre", 857 gremodevent, 858 0 859 }; 860 861 DECLARE_MODULE(if_gre, gre_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 862 MODULE_VERSION(if_gre, 1); 863