1 /* $OpenBSD: if_gre.c,v 1.57 2011/07/12 15:23:50 jsg Exp $ */ 2 /* $NetBSD: if_gre.c,v 1.9 1999/10/25 19:18:11 drochner 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 * 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 * 22 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 23 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 24 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 25 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 26 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 28 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 29 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 30 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 31 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 32 * POSSIBILITY OF SUCH DAMAGE. 33 */ 34 35 /* 36 * Encapsulate L3 protocols into IP, per RFC 1701 and 1702. 37 * See gre(4) for more details. 38 * Also supported: IP in IP encapsulation (proto 55) per RFC 2004. 39 */ 40 41 #include "gre.h" 42 #if NGRE > 0 43 44 #include "bpfilter.h" 45 #include "pf.h" 46 47 #include <sys/param.h> 48 #include <sys/proc.h> 49 #include <sys/mbuf.h> 50 #include <sys/socket.h> 51 #include <sys/sockio.h> 52 #include <sys/kernel.h> 53 #include <sys/systm.h> 54 55 #include <net/if.h> 56 #include <net/if_types.h> 57 #include <net/netisr.h> 58 #include <net/route.h> 59 60 #ifdef INET 61 #include <netinet/in.h> 62 #include <netinet/in_systm.h> 63 #include <netinet/in_var.h> 64 #include <netinet/ip.h> 65 #include <netinet/ip_var.h> 66 #include <netinet/if_ether.h> 67 #else 68 #error "if_gre used without inet" 69 #endif 70 71 #if NBPFILTER > 0 72 #include <net/bpf.h> 73 #endif 74 75 #if NPF > 0 76 #include <net/pfvar.h> 77 #endif 78 79 #include <net/if_gre.h> 80 81 #ifndef GRE_RECURSION_LIMIT 82 #define GRE_RECURSION_LIMIT 3 /* How many levels of recursion allowed */ 83 #endif /* GRE_RECURSION_LIMIT */ 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 int gre_clone_create(struct if_clone *, int); 93 int gre_clone_destroy(struct ifnet *); 94 95 struct gre_softc_head gre_softc_list; 96 struct if_clone gre_cloner = 97 IF_CLONE_INITIALIZER("gre", gre_clone_create, gre_clone_destroy); 98 99 /* 100 * We can control the acceptance of GRE and MobileIP packets by 101 * altering the sysctl net.inet.gre.allow and net.inet.mobileip.allow values 102 * respectively. Zero means drop them, all else is acceptance. We can also 103 * control acceptance of WCCPv1-style GRE packets through the 104 * net.inet.gre.wccp value, but be aware it depends upon normal GRE being 105 * allowed as well. 106 * 107 */ 108 int gre_allow = 0; 109 int gre_wccp = 0; 110 int ip_mobile_allow = 0; 111 112 void gre_keepalive(void *); 113 void gre_send_keepalive(void *); 114 void gre_link_state(struct gre_softc *); 115 116 void 117 greattach(int n) 118 { 119 LIST_INIT(&gre_softc_list); 120 if_clone_attach(&gre_cloner); 121 } 122 123 int 124 gre_clone_create(struct if_clone *ifc, int unit) 125 { 126 struct gre_softc *sc; 127 int s; 128 129 sc = malloc(sizeof(*sc), M_DEVBUF, M_NOWAIT|M_ZERO); 130 if (!sc) 131 return (ENOMEM); 132 snprintf(sc->sc_if.if_xname, sizeof sc->sc_if.if_xname, "%s%d", 133 ifc->ifc_name, unit); 134 sc->sc_if.if_softc = sc; 135 sc->sc_if.if_type = IFT_TUNNEL; 136 sc->sc_if.if_addrlen = 0; 137 sc->sc_if.if_hdrlen = 24; /* IP + GRE */ 138 sc->sc_if.if_mtu = GREMTU; 139 sc->sc_if.if_flags = IFF_POINTOPOINT|IFF_MULTICAST; 140 sc->sc_if.if_output = gre_output; 141 sc->sc_if.if_ioctl = gre_ioctl; 142 sc->sc_if.if_collisions = 0; 143 sc->sc_if.if_ierrors = 0; 144 sc->sc_if.if_oerrors = 0; 145 sc->sc_if.if_ipackets = 0; 146 sc->sc_if.if_opackets = 0; 147 sc->g_dst.s_addr = sc->g_src.s_addr = INADDR_ANY; 148 sc->g_proto = IPPROTO_GRE; 149 sc->sc_if.if_flags |= IFF_LINK0; 150 sc->sc_ka_state = GRE_STATE_UKNWN; 151 152 timeout_set(&sc->sc_ka_hold, gre_keepalive, sc); 153 timeout_set(&sc->sc_ka_snd, gre_send_keepalive, sc); 154 155 if_attach(&sc->sc_if); 156 if_alloc_sadl(&sc->sc_if); 157 158 #if NBPFILTER > 0 159 bpfattach(&sc->sc_if.if_bpf, &sc->sc_if, DLT_NULL, 160 sizeof(u_int32_t)); 161 #endif 162 s = splnet(); 163 LIST_INSERT_HEAD(&gre_softc_list, sc, sc_list); 164 splx(s); 165 166 return (0); 167 } 168 169 int 170 gre_clone_destroy(struct ifnet *ifp) 171 { 172 struct gre_softc *sc = ifp->if_softc; 173 int s; 174 175 s = splnet(); 176 timeout_del(&sc->sc_ka_snd); 177 timeout_del(&sc->sc_ka_hold); 178 LIST_REMOVE(sc, sc_list); 179 splx(s); 180 181 if_detach(ifp); 182 183 free(sc, M_DEVBUF); 184 return (0); 185 } 186 187 /* 188 * The output routine. Takes a packet and encapsulates it in the protocol 189 * given by sc->g_proto. See also RFC 1701 and RFC 2004. 190 */ 191 192 int 193 gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 194 struct rtentry *rt) 195 { 196 int error = 0; 197 struct gre_softc *sc = (struct gre_softc *) (ifp->if_softc); 198 struct greip *gh = NULL; 199 struct ip *inp = NULL; 200 u_int8_t ip_tos = 0; 201 u_int16_t etype = 0; 202 struct mobile_h mob_h; 203 struct m_tag *mtag; 204 205 if ((ifp->if_flags & IFF_UP) == 0 || 206 sc->g_src.s_addr == INADDR_ANY || sc->g_dst.s_addr == INADDR_ANY) { 207 m_freem(m); 208 error = ENETDOWN; 209 goto end; 210 } 211 212 #ifdef DIAGNOSTIC 213 if (ifp->if_rdomain != rtable_l2(m->m_pkthdr.rdomain)) { 214 printf("%s: trying to send packet on wrong domain. " 215 "if %d vs. mbuf %d, AF %d\n", ifp->if_xname, 216 ifp->if_rdomain, rtable_l2(m->m_pkthdr.rdomain), 217 dst->sa_family); 218 } 219 #endif 220 221 /* Try to limit infinite recursion through misconfiguration. */ 222 for (mtag = m_tag_find(m, PACKET_TAG_GRE, NULL); mtag; 223 mtag = m_tag_find(m, PACKET_TAG_GRE, mtag)) { 224 if (!bcmp((caddr_t)(mtag + 1), &ifp, sizeof(struct ifnet *))) { 225 IF_DROP(&ifp->if_snd); 226 m_freem(m); 227 error = EIO; 228 goto end; 229 } 230 } 231 232 mtag = m_tag_get(PACKET_TAG_GRE, sizeof(struct ifnet *), M_NOWAIT); 233 if (mtag == NULL) { 234 IF_DROP(&ifp->if_snd); 235 m_freem(m); 236 error = ENOBUFS; 237 goto end; 238 } 239 bcopy(&ifp, (caddr_t)(mtag + 1), sizeof(struct ifnet *)); 240 m_tag_prepend(m, mtag); 241 242 m->m_flags &= ~(M_BCAST|M_MCAST); 243 244 #if NBPFILTER > 0 245 if (ifp->if_bpf) 246 bpf_mtap_af(ifp->if_bpf, dst->sa_family, m, BPF_DIRECTION_OUT); 247 #endif 248 249 if (sc->g_proto == IPPROTO_MOBILE) { 250 if (ip_mobile_allow == 0) { 251 IF_DROP(&ifp->if_snd); 252 m_freem(m); 253 error = EACCES; 254 goto end; 255 } 256 257 if (dst->sa_family == AF_INET) { 258 struct mbuf *m0; 259 int msiz; 260 261 /* 262 * Make sure the complete IP header (with options) 263 * is in the first mbuf. 264 */ 265 if (m->m_len < sizeof(struct ip)) { 266 m = m_pullup(m, sizeof(struct ip)); 267 if (m == NULL) { 268 IF_DROP(&ifp->if_snd); 269 error = ENOBUFS; 270 goto end; 271 } else 272 inp = mtod(m, struct ip *); 273 274 if (m->m_len < inp->ip_hl << 2) { 275 m = m_pullup(m, inp->ip_hl << 2); 276 if (m == NULL) { 277 IF_DROP(&ifp->if_snd); 278 error = ENOBUFS; 279 goto end; 280 } 281 } 282 } 283 284 inp = mtod(m, struct ip *); 285 286 bzero(&mob_h, MOB_H_SIZ_L); 287 mob_h.proto = (inp->ip_p) << 8; 288 mob_h.odst = inp->ip_dst.s_addr; 289 inp->ip_dst.s_addr = sc->g_dst.s_addr; 290 291 /* 292 * If the packet comes from our host, we only change 293 * the destination address in the IP header. 294 * Otherwise we need to save and change the source. 295 */ 296 if (inp->ip_src.s_addr == sc->g_src.s_addr) { 297 msiz = MOB_H_SIZ_S; 298 } else { 299 mob_h.proto |= MOB_H_SBIT; 300 mob_h.osrc = inp->ip_src.s_addr; 301 inp->ip_src.s_addr = sc->g_src.s_addr; 302 msiz = MOB_H_SIZ_L; 303 } 304 305 HTONS(mob_h.proto); 306 mob_h.hcrc = gre_in_cksum((u_int16_t *) &mob_h, msiz); 307 308 /* Squeeze in the mobility header */ 309 if ((m->m_data - msiz) < m->m_pktdat) { 310 /* Need new mbuf */ 311 MGETHDR(m0, M_DONTWAIT, MT_HEADER); 312 if (m0 == NULL) { 313 IF_DROP(&ifp->if_snd); 314 m_freem(m); 315 error = ENOBUFS; 316 goto end; 317 } 318 M_MOVE_HDR(m0, m); 319 320 m0->m_len = msiz + (inp->ip_hl << 2); 321 m0->m_data += max_linkhdr; 322 m0->m_pkthdr.len = m->m_pkthdr.len + msiz; 323 m->m_data += inp->ip_hl << 2; 324 m->m_len -= inp->ip_hl << 2; 325 326 bcopy((caddr_t) inp, mtod(m0, caddr_t), 327 sizeof(struct ip)); 328 329 m0->m_next = m; 330 m = m0; 331 } else { /* we have some space left in the old one */ 332 m->m_data -= msiz; 333 m->m_len += msiz; 334 m->m_pkthdr.len += msiz; 335 bcopy(inp, mtod(m, caddr_t), 336 inp->ip_hl << 2); 337 } 338 339 /* Copy Mobility header */ 340 inp = mtod(m, struct ip *); 341 bcopy(&mob_h, (caddr_t)(inp + 1), (unsigned) msiz); 342 inp->ip_len = htons(ntohs(inp->ip_len) + msiz); 343 } else { /* AF_INET */ 344 IF_DROP(&ifp->if_snd); 345 m_freem(m); 346 error = EINVAL; 347 goto end; 348 } 349 } else if (sc->g_proto == IPPROTO_GRE) { 350 if (gre_allow == 0) { 351 IF_DROP(&ifp->if_snd); 352 m_freem(m); 353 error = EACCES; 354 goto end; 355 } 356 357 switch(dst->sa_family) { 358 case AF_INET: 359 if (m->m_len < sizeof(struct ip)) { 360 m = m_pullup(m, sizeof(struct ip)); 361 if (m == NULL) { 362 IF_DROP(&ifp->if_snd); 363 error = ENOBUFS; 364 goto end; 365 } 366 } 367 368 inp = mtod(m, struct ip *); 369 ip_tos = inp->ip_tos; 370 etype = ETHERTYPE_IP; 371 break; 372 #ifdef INET6 373 case AF_INET6: 374 etype = ETHERTYPE_IPV6; 375 break; 376 #endif 377 #ifdef MPLS 378 case AF_MPLS: 379 if (m->m_flags & (M_BCAST | M_MCAST)) 380 etype = ETHERTYPE_MPLS_MCAST; 381 else 382 etype = ETHERTYPE_MPLS; 383 break; 384 #endif 385 default: 386 IF_DROP(&ifp->if_snd); 387 m_freem(m); 388 error = EAFNOSUPPORT; 389 goto end; 390 } 391 392 M_PREPEND(m, sizeof(struct greip), M_DONTWAIT); 393 } else { 394 IF_DROP(&ifp->if_snd); 395 m_freem(m); 396 error = EINVAL; 397 goto end; 398 } 399 400 if (m == NULL) { 401 IF_DROP(&ifp->if_snd); 402 error = ENOBUFS; 403 goto end; 404 } 405 406 gh = mtod(m, struct greip *); 407 if (sc->g_proto == IPPROTO_GRE) { 408 /* We don't support any GRE flags for now */ 409 410 bzero((void *) &gh->gi_g, sizeof(struct gre_h)); 411 gh->gi_ptype = htons(etype); 412 } 413 414 gh->gi_pr = sc->g_proto; 415 if (sc->g_proto != IPPROTO_MOBILE) { 416 gh->gi_src = sc->g_src; 417 gh->gi_dst = sc->g_dst; 418 ((struct ip *) gh)->ip_hl = (sizeof(struct ip)) >> 2; 419 ((struct ip *) gh)->ip_ttl = ip_defttl; 420 ((struct ip *) gh)->ip_tos = ip_tos; 421 gh->gi_len = htons(m->m_pkthdr.len); 422 } 423 424 ifp->if_opackets++; 425 ifp->if_obytes += m->m_pkthdr.len; 426 427 428 m->m_pkthdr.rdomain = sc->g_rtableid; 429 430 #if NPF > 0 431 pf_pkt_addr_changed(m); 432 #endif 433 434 /* Send it off */ 435 error = ip_output(m, (void *)NULL, &sc->route, 0, (void *)NULL, (void *)NULL); 436 end: 437 if (error) 438 ifp->if_oerrors++; 439 return (error); 440 } 441 442 int 443 gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 444 { 445 446 struct ifreq *ifr = (struct ifreq *) data; 447 struct if_laddrreq *lifr = (struct if_laddrreq *)data; 448 struct ifkalivereq *ikar = (struct ifkalivereq *)data; 449 struct gre_softc *sc = ifp->if_softc; 450 int s; 451 struct sockaddr_in si; 452 struct sockaddr *sa = NULL; 453 int error = 0; 454 struct proc *prc = curproc; /* XXX */ 455 456 s = splnet(); 457 switch(cmd) { 458 case SIOCSIFADDR: 459 ifp->if_flags |= IFF_UP; 460 break; 461 case SIOCSIFDSTADDR: 462 break; 463 case SIOCSIFFLAGS: 464 if ((ifr->ifr_flags & IFF_LINK0) != 0) 465 sc->g_proto = IPPROTO_GRE; 466 else 467 sc->g_proto = IPPROTO_MOBILE; 468 break; 469 case SIOCSIFMTU: 470 if (ifr->ifr_mtu < 576) { 471 error = EINVAL; 472 break; 473 } 474 ifp->if_mtu = ifr->ifr_mtu; 475 break; 476 case SIOCGIFMTU: 477 ifr->ifr_mtu = sc->sc_if.if_mtu; 478 break; 479 case SIOCADDMULTI: 480 case SIOCDELMULTI: 481 if (ifr == 0) { 482 error = EAFNOSUPPORT; 483 break; 484 } 485 switch (ifr->ifr_addr.sa_family) { 486 #ifdef INET 487 case AF_INET: 488 break; 489 #endif 490 #ifdef INET6 491 case AF_INET6: 492 break; 493 #endif 494 default: 495 error = EAFNOSUPPORT; 496 break; 497 } 498 break; 499 case GRESPROTO: 500 /* Check for superuser */ 501 if ((error = suser(prc, 0)) != 0) 502 break; 503 504 sc->g_proto = ifr->ifr_flags; 505 switch (sc->g_proto) { 506 case IPPROTO_GRE: 507 ifp->if_flags |= IFF_LINK0; 508 break; 509 case IPPROTO_MOBILE: 510 ifp->if_flags &= ~IFF_LINK0; 511 break; 512 default: 513 error = EPROTONOSUPPORT; 514 break; 515 } 516 break; 517 case GREGPROTO: 518 ifr->ifr_flags = sc->g_proto; 519 break; 520 case GRESADDRS: 521 case GRESADDRD: 522 /* Check for superuser */ 523 if ((error = suser(prc, 0)) != 0) 524 break; 525 526 /* 527 * set tunnel endpoints and mark if as up 528 */ 529 sa = &ifr->ifr_addr; 530 if (cmd == GRESADDRS ) 531 sc->g_src = (satosin(sa))->sin_addr; 532 if (cmd == GRESADDRD ) 533 sc->g_dst = (satosin(sa))->sin_addr; 534 recompute: 535 if ((sc->g_src.s_addr != INADDR_ANY) && 536 (sc->g_dst.s_addr != INADDR_ANY)) { 537 if (sc->route.ro_rt != 0) 538 RTFREE(sc->route.ro_rt); 539 /* ip_output() will do the lookup */ 540 bzero(&sc->route, sizeof(sc->route)); 541 ifp->if_flags |= IFF_UP; 542 } 543 break; 544 case GREGADDRS: 545 bzero(&si, sizeof(si)); 546 si.sin_family = AF_INET; 547 si.sin_len = sizeof(struct sockaddr_in); 548 si.sin_addr.s_addr = sc->g_src.s_addr; 549 sa = sintosa(&si); 550 ifr->ifr_addr = *sa; 551 break; 552 case GREGADDRD: 553 bzero(&si, sizeof(si)); 554 si.sin_family = AF_INET; 555 si.sin_len = sizeof(struct sockaddr_in); 556 si.sin_addr.s_addr = sc->g_dst.s_addr; 557 sa = sintosa(&si); 558 ifr->ifr_addr = *sa; 559 break; 560 case SIOCSETKALIVE: 561 if ((error = suser(prc, 0)) != 0) 562 break; 563 if (ikar->ikar_timeo < 0 || ikar->ikar_timeo > 86400 || 564 ikar->ikar_cnt < 0 || ikar->ikar_cnt > 256) { 565 error = EINVAL; 566 break; 567 } 568 sc->sc_ka_timout = ikar->ikar_timeo; 569 sc->sc_ka_cnt = ikar->ikar_cnt; 570 if (sc->sc_ka_timout == 0 || sc->sc_ka_cnt == 0) { 571 sc->sc_ka_timout = 0; 572 sc->sc_ka_cnt = 0; 573 sc->sc_ka_state = GRE_STATE_UKNWN; 574 gre_link_state(sc); 575 break; 576 } 577 if (!timeout_pending(&sc->sc_ka_snd)) { 578 sc->sc_ka_holdmax = sc->sc_ka_cnt; 579 timeout_add(&sc->sc_ka_snd, 1); 580 timeout_add_sec(&sc->sc_ka_hold, sc->sc_ka_timout * 581 sc->sc_ka_cnt); 582 } 583 break; 584 case SIOCGETKALIVE: 585 ikar->ikar_timeo = sc->sc_ka_timout; 586 ikar->ikar_cnt = sc->sc_ka_cnt; 587 break; 588 case SIOCSLIFPHYADDR: 589 if ((error = suser(prc, 0)) != 0) 590 break; 591 if (lifr->addr.ss_family != AF_INET || 592 lifr->dstaddr.ss_family != AF_INET) { 593 error = EAFNOSUPPORT; 594 break; 595 } 596 if (lifr->addr.ss_len != sizeof(si) || 597 lifr->dstaddr.ss_len != sizeof(si)) { 598 error = EINVAL; 599 break; 600 } 601 sc->g_src = (satosin((struct sockadrr *)&lifr->addr))->sin_addr; 602 sc->g_dst = 603 (satosin((struct sockadrr *)&lifr->dstaddr))->sin_addr; 604 goto recompute; 605 case SIOCDIFPHYADDR: 606 if ((error = suser(prc, 0)) != 0) 607 break; 608 sc->g_src.s_addr = INADDR_ANY; 609 sc->g_dst.s_addr = INADDR_ANY; 610 break; 611 case SIOCGLIFPHYADDR: 612 if (sc->g_src.s_addr == INADDR_ANY || 613 sc->g_dst.s_addr == INADDR_ANY) { 614 error = EADDRNOTAVAIL; 615 break; 616 } 617 bzero(&si, sizeof(si)); 618 si.sin_family = AF_INET; 619 si.sin_len = sizeof(struct sockaddr_in); 620 si.sin_addr.s_addr = sc->g_src.s_addr; 621 memcpy(&lifr->addr, &si, sizeof(si)); 622 si.sin_addr.s_addr = sc->g_dst.s_addr; 623 memcpy(&lifr->dstaddr, &si, sizeof(si)); 624 break; 625 case SIOCSLIFPHYRTABLE: 626 if ((error = suser(prc, 0)) != 0) 627 break; 628 if (ifr->ifr_rdomainid < 0 || 629 ifr->ifr_rdomainid > RT_TABLEID_MAX || 630 !rtable_exists(ifr->ifr_rdomainid)) { 631 error = EINVAL; 632 break; 633 } 634 sc->g_rtableid = ifr->ifr_rdomainid; 635 goto recompute; 636 case SIOCGLIFPHYRTABLE: 637 ifr->ifr_rdomainid = sc->g_rtableid; 638 break; 639 default: 640 error = ENOTTY; 641 } 642 643 splx(s); 644 return (error); 645 } 646 647 /* 648 * do a checksum of a buffer - much like in_cksum, which operates on 649 * mbufs. 650 */ 651 u_int16_t 652 gre_in_cksum(u_int16_t *p, u_int len) 653 { 654 u_int32_t sum = 0; 655 int nwords = len >> 1; 656 657 while (nwords-- != 0) 658 sum += *p++; 659 660 if (len & 1) { 661 union { 662 u_short w; 663 u_char c[2]; 664 } u; 665 u.c[0] = *(u_char *) p; 666 u.c[1] = 0; 667 sum += u.w; 668 } 669 670 /* end-around-carry */ 671 sum = (sum >> 16) + (sum & 0xffff); 672 sum += (sum >> 16); 673 return (~sum); 674 } 675 676 void 677 gre_keepalive(void *arg) 678 { 679 struct gre_softc *sc = arg; 680 681 if (!sc->sc_ka_timout) 682 return; 683 684 sc->sc_ka_state = GRE_STATE_DOWN; 685 gre_link_state(sc); 686 } 687 688 void 689 gre_send_keepalive(void *arg) 690 { 691 struct gre_softc *sc = arg; 692 struct mbuf *m; 693 struct ip *ip; 694 struct gre_h *gh; 695 struct sockaddr dst; 696 int s; 697 698 if (sc->sc_ka_timout) 699 timeout_add_sec(&sc->sc_ka_snd, sc->sc_ka_timout); 700 701 if (sc->g_proto != IPPROTO_GRE) 702 return; 703 if ((sc->sc_if.if_flags & IFF_UP) == 0 || 704 sc->g_src.s_addr == INADDR_ANY || sc->g_dst.s_addr == INADDR_ANY) 705 return; 706 707 MGETHDR(m, M_DONTWAIT, MT_DATA); 708 if (m == NULL) { 709 sc->sc_if.if_oerrors++; 710 return; 711 } 712 713 m->m_len = m->m_pkthdr.len = sizeof(*ip) + sizeof(*gh); 714 MH_ALIGN(m, m->m_len); 715 716 /* build the ip header */ 717 ip = mtod(m, struct ip *); 718 719 ip->ip_v = IPVERSION; 720 ip->ip_hl = sizeof(*ip) >> 2; 721 ip->ip_tos = IPTOS_LOWDELAY; 722 ip->ip_len = htons(m->m_pkthdr.len); 723 ip->ip_id = htons(ip_randomid()); 724 ip->ip_off = htons(IP_DF); 725 ip->ip_ttl = ip_defttl; 726 ip->ip_p = IPPROTO_GRE; 727 ip->ip_src.s_addr = sc->g_dst.s_addr; 728 ip->ip_dst.s_addr = sc->g_src.s_addr; 729 ip->ip_sum = 0; 730 ip->ip_sum = in_cksum(m, sizeof(*ip)); 731 732 gh = (struct gre_h *)(ip + 1); 733 /* We don't support any GRE flags for now */ 734 bzero(gh, sizeof(*gh)); 735 736 bzero(&dst, sizeof(dst)); 737 dst.sa_family = AF_INET; 738 739 s = splsoftnet(); 740 /* should we care about the error? */ 741 gre_output(&sc->sc_if, m, &dst, NULL); 742 splx(s); 743 } 744 745 void 746 gre_recv_keepalive(struct gre_softc *sc) 747 { 748 if (!sc->sc_ka_timout) 749 return; 750 751 /* link state flap dampening */ 752 switch (sc->sc_ka_state) { 753 case GRE_STATE_UKNWN: 754 case GRE_STATE_DOWN: 755 sc->sc_ka_state = GRE_STATE_HOLD; 756 sc->sc_ka_holdcnt = sc->sc_ka_holdmax; 757 sc->sc_ka_holdmax = MIN(sc->sc_ka_holdmax * 2, 758 16 * sc->sc_ka_cnt); 759 break; 760 case GRE_STATE_HOLD: 761 if (--sc->sc_ka_holdcnt < 1) { 762 sc->sc_ka_state = GRE_STATE_UP; 763 gre_link_state(sc); 764 } 765 break; 766 case GRE_STATE_UP: 767 sc->sc_ka_holdmax--; 768 sc->sc_ka_holdmax = MAX(sc->sc_ka_holdmax, sc->sc_ka_cnt); 769 break; 770 } 771 772 /* rescedule hold timer */ 773 timeout_add_sec(&sc->sc_ka_hold, sc->sc_ka_timout * sc->sc_ka_cnt); 774 } 775 776 void 777 gre_link_state(struct gre_softc *sc) 778 { 779 struct ifnet *ifp = &sc->sc_if; 780 int link_state = LINK_STATE_UNKNOWN; 781 782 if (sc->sc_ka_state == GRE_STATE_UP) 783 link_state = LINK_STATE_UP; 784 else if (sc->sc_ka_state != GRE_STATE_UKNWN) 785 link_state = LINK_STATE_KALIVE_DOWN; 786 787 if (ifp->if_link_state != link_state) { 788 ifp->if_link_state = link_state; 789 if_link_state_change(ifp); 790 } 791 } 792 #endif 793