1 /*- 2 * Copyright (c) 2014 Andrey V. Elsukov <ae@FreeBSD.org> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/param.h> 31 #include <sys/jail.h> 32 #include <sys/kernel.h> 33 #include <sys/lock.h> 34 #include <sys/libkern.h> 35 #include <sys/malloc.h> 36 #include <sys/module.h> 37 #include <sys/mbuf.h> 38 #include <sys/priv.h> 39 #include <sys/proc.h> 40 #include <sys/protosw.h> 41 #include <sys/rmlock.h> 42 #include <sys/socket.h> 43 #include <sys/sockio.h> 44 #include <sys/sx.h> 45 #include <sys/sysctl.h> 46 #include <sys/syslog.h> 47 #include <sys/systm.h> 48 49 #include <net/bpf.h> 50 #include <net/ethernet.h> 51 #include <net/if.h> 52 #include <net/if_var.h> 53 #include <net/if_clone.h> 54 #include <net/if_types.h> 55 #include <net/netisr.h> 56 #include <net/vnet.h> 57 #include <net/route.h> 58 59 #include <netinet/in.h> 60 #include <netinet/in_systm.h> 61 #include <netinet/in_var.h> 62 #include <netinet/ip.h> 63 #include <netinet/ip_var.h> 64 #include <netinet/ip_encap.h> 65 66 #include <machine/in_cksum.h> 67 #include <security/mac/mac_framework.h> 68 69 #define MEMTU 1500 70 static const char mename[] = "me"; 71 static MALLOC_DEFINE(M_IFME, mename, "Minimal Encapsulation for IP"); 72 static VNET_DEFINE(struct mtx, me_mtx); 73 #define V_me_mtx VNET(me_mtx) 74 /* Minimal forwarding header RFC 2004 */ 75 struct mobhdr { 76 uint8_t mob_proto; /* protocol */ 77 uint8_t mob_flags; /* flags */ 78 #define MOB_FLAGS_SP 0x80 /* source present */ 79 uint16_t mob_csum; /* header checksum */ 80 struct in_addr mob_dst; /* original destination address */ 81 struct in_addr mob_src; /* original source addr (optional) */ 82 } __packed; 83 84 struct me_softc { 85 struct ifnet *me_ifp; 86 LIST_ENTRY(me_softc) me_list; 87 struct rmlock me_lock; 88 u_int me_fibnum; 89 const struct encaptab *me_ecookie; 90 struct in_addr me_src; 91 struct in_addr me_dst; 92 }; 93 #define ME2IFP(sc) ((sc)->me_ifp) 94 #define ME_READY(sc) ((sc)->me_src.s_addr != 0) 95 #define ME_LOCK_INIT(sc) rm_init(&(sc)->me_lock, "me softc") 96 #define ME_LOCK_DESTROY(sc) rm_destroy(&(sc)->me_lock) 97 #define ME_RLOCK_TRACKER struct rm_priotracker me_tracker 98 #define ME_RLOCK(sc) rm_rlock(&(sc)->me_lock, &me_tracker) 99 #define ME_RUNLOCK(sc) rm_runlock(&(sc)->me_lock, &me_tracker) 100 #define ME_RLOCK_ASSERT(sc) rm_assert(&(sc)->me_lock, RA_RLOCKED) 101 #define ME_WLOCK(sc) rm_wlock(&(sc)->me_lock) 102 #define ME_WUNLOCK(sc) rm_wunlock(&(sc)->me_lock) 103 #define ME_WLOCK_ASSERT(sc) rm_assert(&(sc)->me_lock, RA_WLOCKED) 104 105 #define ME_LIST_LOCK_INIT(x) mtx_init(&V_me_mtx, "me_mtx", NULL, MTX_DEF) 106 #define ME_LIST_LOCK_DESTROY(x) mtx_destroy(&V_me_mtx) 107 #define ME_LIST_LOCK(x) mtx_lock(&V_me_mtx) 108 #define ME_LIST_UNLOCK(x) mtx_unlock(&V_me_mtx) 109 110 static VNET_DEFINE(LIST_HEAD(, me_softc), me_softc_list); 111 #define V_me_softc_list VNET(me_softc_list) 112 static struct sx me_ioctl_sx; 113 SX_SYSINIT(me_ioctl_sx, &me_ioctl_sx, "me_ioctl"); 114 115 static int me_clone_create(struct if_clone *, int, caddr_t); 116 static void me_clone_destroy(struct ifnet *); 117 static VNET_DEFINE(struct if_clone *, me_cloner); 118 #define V_me_cloner VNET(me_cloner) 119 120 static void me_qflush(struct ifnet *); 121 static int me_transmit(struct ifnet *, struct mbuf *); 122 static int me_ioctl(struct ifnet *, u_long, caddr_t); 123 static int me_output(struct ifnet *, struct mbuf *, 124 const struct sockaddr *, struct route *); 125 static int me_input(struct mbuf **, int *, int); 126 127 static int me_set_tunnel(struct ifnet *, struct sockaddr_in *, 128 struct sockaddr_in *); 129 static void me_delete_tunnel(struct ifnet *); 130 131 SYSCTL_DECL(_net_link); 132 static SYSCTL_NODE(_net_link, IFT_TUNNEL, me, CTLFLAG_RW, 0, 133 "Minimal Encapsulation for IP (RFC 2004)"); 134 #ifndef MAX_ME_NEST 135 #define MAX_ME_NEST 1 136 #endif 137 138 static VNET_DEFINE(int, max_me_nesting) = MAX_ME_NEST; 139 #define V_max_me_nesting VNET(max_me_nesting) 140 SYSCTL_INT(_net_link_me, OID_AUTO, max_nesting, CTLFLAG_RW | CTLFLAG_VNET, 141 &VNET_NAME(max_me_nesting), 0, "Max nested tunnels"); 142 143 extern struct domain inetdomain; 144 static const struct protosw in_mobile_protosw = { 145 .pr_type = SOCK_RAW, 146 .pr_domain = &inetdomain, 147 .pr_protocol = IPPROTO_MOBILE, 148 .pr_flags = PR_ATOMIC|PR_ADDR, 149 .pr_input = me_input, 150 .pr_output = rip_output, 151 .pr_ctlinput = rip_ctlinput, 152 .pr_ctloutput = rip_ctloutput, 153 .pr_usrreqs = &rip_usrreqs 154 }; 155 156 static void 157 vnet_me_init(const void *unused __unused) 158 { 159 LIST_INIT(&V_me_softc_list); 160 ME_LIST_LOCK_INIT(); 161 V_me_cloner = if_clone_simple(mename, me_clone_create, 162 me_clone_destroy, 0); 163 } 164 VNET_SYSINIT(vnet_me_init, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY, 165 vnet_me_init, NULL); 166 167 static void 168 vnet_me_uninit(const void *unused __unused) 169 { 170 171 if_clone_detach(V_me_cloner); 172 ME_LIST_LOCK_DESTROY(); 173 } 174 VNET_SYSUNINIT(vnet_me_uninit, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY, 175 vnet_me_uninit, NULL); 176 177 static int 178 me_clone_create(struct if_clone *ifc, int unit, caddr_t params) 179 { 180 struct me_softc *sc; 181 182 sc = malloc(sizeof(struct me_softc), M_IFME, M_WAITOK | M_ZERO); 183 sc->me_fibnum = curthread->td_proc->p_fibnum; 184 ME2IFP(sc) = if_alloc(IFT_TUNNEL); 185 ME_LOCK_INIT(sc); 186 ME2IFP(sc)->if_softc = sc; 187 if_initname(ME2IFP(sc), mename, unit); 188 189 ME2IFP(sc)->if_mtu = MEMTU - sizeof(struct mobhdr); 190 ME2IFP(sc)->if_flags = IFF_POINTOPOINT|IFF_MULTICAST; 191 ME2IFP(sc)->if_output = me_output; 192 ME2IFP(sc)->if_ioctl = me_ioctl; 193 ME2IFP(sc)->if_transmit = me_transmit; 194 ME2IFP(sc)->if_qflush = me_qflush; 195 ME2IFP(sc)->if_capabilities |= IFCAP_LINKSTATE; 196 ME2IFP(sc)->if_capenable |= IFCAP_LINKSTATE; 197 if_attach(ME2IFP(sc)); 198 bpfattach(ME2IFP(sc), DLT_NULL, sizeof(u_int32_t)); 199 ME_LIST_LOCK(); 200 LIST_INSERT_HEAD(&V_me_softc_list, sc, me_list); 201 ME_LIST_UNLOCK(); 202 return (0); 203 } 204 205 static void 206 me_clone_destroy(struct ifnet *ifp) 207 { 208 struct me_softc *sc; 209 210 sx_xlock(&me_ioctl_sx); 211 sc = ifp->if_softc; 212 me_delete_tunnel(ifp); 213 ME_LIST_LOCK(); 214 LIST_REMOVE(sc, me_list); 215 ME_LIST_UNLOCK(); 216 bpfdetach(ifp); 217 if_detach(ifp); 218 ifp->if_softc = NULL; 219 sx_xunlock(&me_ioctl_sx); 220 221 if_free(ifp); 222 ME_LOCK_DESTROY(sc); 223 free(sc, M_IFME); 224 } 225 226 static int 227 me_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 228 { 229 ME_RLOCK_TRACKER; 230 struct ifreq *ifr = (struct ifreq *)data; 231 struct sockaddr_in *src, *dst; 232 struct me_softc *sc; 233 int error; 234 235 switch (cmd) { 236 case SIOCSIFMTU: 237 if (ifr->ifr_mtu < 576) 238 return (EINVAL); 239 ifp->if_mtu = ifr->ifr_mtu - sizeof(struct mobhdr); 240 return (0); 241 case SIOCSIFADDR: 242 ifp->if_flags |= IFF_UP; 243 case SIOCSIFFLAGS: 244 case SIOCADDMULTI: 245 case SIOCDELMULTI: 246 return (0); 247 } 248 sx_xlock(&me_ioctl_sx); 249 sc = ifp->if_softc; 250 if (sc == NULL) { 251 error = ENXIO; 252 goto end; 253 } 254 error = 0; 255 switch (cmd) { 256 case SIOCSIFPHYADDR: 257 src = (struct sockaddr_in *) 258 &(((struct in_aliasreq *)data)->ifra_addr); 259 dst = (struct sockaddr_in *) 260 &(((struct in_aliasreq *)data)->ifra_dstaddr); 261 if (src->sin_family != dst->sin_family || 262 src->sin_family != AF_INET || 263 src->sin_len != dst->sin_len || 264 src->sin_len != sizeof(struct sockaddr_in)) { 265 error = EINVAL; 266 break; 267 } 268 if (src->sin_addr.s_addr == INADDR_ANY || 269 dst->sin_addr.s_addr == INADDR_ANY) { 270 error = EADDRNOTAVAIL; 271 break; 272 } 273 error = me_set_tunnel(ifp, src, dst); 274 break; 275 case SIOCDIFPHYADDR: 276 me_delete_tunnel(ifp); 277 break; 278 case SIOCGIFPSRCADDR: 279 case SIOCGIFPDSTADDR: 280 ME_RLOCK(sc); 281 if (!ME_READY(sc)) { 282 error = EADDRNOTAVAIL; 283 ME_RUNLOCK(sc); 284 break; 285 } 286 src = (struct sockaddr_in *)&ifr->ifr_addr; 287 memset(src, 0, sizeof(*src)); 288 src->sin_family = AF_INET; 289 src->sin_len = sizeof(*src); 290 switch (cmd) { 291 case SIOCGIFPSRCADDR: 292 src->sin_addr = sc->me_src; 293 break; 294 case SIOCGIFPDSTADDR: 295 src->sin_addr = sc->me_dst; 296 break; 297 } 298 ME_RUNLOCK(sc); 299 error = prison_if(curthread->td_ucred, sintosa(src)); 300 if (error != 0) 301 memset(src, 0, sizeof(*src)); 302 break; 303 case SIOCGTUNFIB: 304 ifr->ifr_fib = sc->me_fibnum; 305 break; 306 case SIOCSTUNFIB: 307 if ((error = priv_check(curthread, PRIV_NET_GRE)) != 0) 308 break; 309 if (ifr->ifr_fib >= rt_numfibs) 310 error = EINVAL; 311 else 312 sc->me_fibnum = ifr->ifr_fib; 313 break; 314 default: 315 error = EINVAL; 316 break; 317 } 318 end: 319 sx_xunlock(&me_ioctl_sx); 320 return (error); 321 } 322 323 static int 324 me_encapcheck(const struct mbuf *m, int off, int proto, void *arg) 325 { 326 ME_RLOCK_TRACKER; 327 struct me_softc *sc; 328 struct ip *ip; 329 int ret; 330 331 sc = (struct me_softc *)arg; 332 if ((ME2IFP(sc)->if_flags & IFF_UP) == 0) 333 return (0); 334 335 M_ASSERTPKTHDR(m); 336 337 if (m->m_pkthdr.len < sizeof(struct ip) + sizeof(struct mobhdr) - 338 sizeof(struct in_addr)) 339 return (0); 340 341 ret = 0; 342 ME_RLOCK(sc); 343 if (ME_READY(sc)) { 344 ip = mtod(m, struct ip *); 345 if (sc->me_src.s_addr == ip->ip_dst.s_addr && 346 sc->me_dst.s_addr == ip->ip_src.s_addr) 347 ret = 32 * 2; 348 } 349 ME_RUNLOCK(sc); 350 return (ret); 351 } 352 353 static int 354 me_set_tunnel(struct ifnet *ifp, struct sockaddr_in *src, 355 struct sockaddr_in *dst) 356 { 357 struct me_softc *sc, *tsc; 358 359 sx_assert(&me_ioctl_sx, SA_XLOCKED); 360 ME_LIST_LOCK(); 361 sc = ifp->if_softc; 362 LIST_FOREACH(tsc, &V_me_softc_list, me_list) { 363 if (tsc == sc || !ME_READY(tsc)) 364 continue; 365 if (tsc->me_src.s_addr == src->sin_addr.s_addr && 366 tsc->me_dst.s_addr == dst->sin_addr.s_addr) { 367 ME_LIST_UNLOCK(); 368 return (EADDRNOTAVAIL); 369 } 370 } 371 ME_LIST_UNLOCK(); 372 373 ME_WLOCK(sc); 374 sc->me_dst = dst->sin_addr; 375 sc->me_src = src->sin_addr; 376 ME_WUNLOCK(sc); 377 378 if (sc->me_ecookie == NULL) 379 sc->me_ecookie = encap_attach_func(AF_INET, IPPROTO_MOBILE, 380 me_encapcheck, &in_mobile_protosw, sc); 381 if (sc->me_ecookie != NULL) { 382 ifp->if_drv_flags |= IFF_DRV_RUNNING; 383 if_link_state_change(ifp, LINK_STATE_UP); 384 } 385 return (0); 386 } 387 388 static void 389 me_delete_tunnel(struct ifnet *ifp) 390 { 391 struct me_softc *sc = ifp->if_softc; 392 393 sx_assert(&me_ioctl_sx, SA_XLOCKED); 394 if (sc->me_ecookie != NULL) 395 encap_detach(sc->me_ecookie); 396 sc->me_ecookie = NULL; 397 ME_WLOCK(sc); 398 sc->me_src.s_addr = 0; 399 sc->me_dst.s_addr = 0; 400 ME_WUNLOCK(sc); 401 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 402 if_link_state_change(ifp, LINK_STATE_DOWN); 403 } 404 405 static uint16_t 406 me_in_cksum(uint16_t *p, int nwords) 407 { 408 uint32_t sum = 0; 409 410 while (nwords-- > 0) 411 sum += *p++; 412 sum = (sum >> 16) + (sum & 0xffff); 413 sum += (sum >> 16); 414 return (~sum); 415 } 416 417 int 418 me_input(struct mbuf **mp, int *offp, int proto) 419 { 420 struct me_softc *sc; 421 struct mobhdr *mh; 422 struct ifnet *ifp; 423 struct mbuf *m; 424 struct ip *ip; 425 int hlen; 426 427 m = *mp; 428 sc = encap_getarg(m); 429 KASSERT(sc != NULL, ("encap_getarg returned NULL")); 430 431 ifp = ME2IFP(sc); 432 /* checks for short packets */ 433 hlen = sizeof(struct mobhdr); 434 if (m->m_pkthdr.len < sizeof(struct ip) + hlen) 435 hlen -= sizeof(struct in_addr); 436 if (m->m_len < sizeof(struct ip) + hlen) 437 m = m_pullup(m, sizeof(struct ip) + hlen); 438 if (m == NULL) 439 goto drop; 440 mh = (struct mobhdr *)mtodo(m, sizeof(struct ip)); 441 /* check for wrong flags */ 442 if (mh->mob_flags & (~MOB_FLAGS_SP)) { 443 m_freem(m); 444 goto drop; 445 } 446 if (mh->mob_flags) { 447 if (hlen != sizeof(struct mobhdr)) { 448 m_freem(m); 449 goto drop; 450 } 451 } else 452 hlen = sizeof(struct mobhdr) - sizeof(struct in_addr); 453 /* check mobile header checksum */ 454 if (me_in_cksum((uint16_t *)mh, hlen / sizeof(uint16_t)) != 0) { 455 m_freem(m); 456 goto drop; 457 } 458 #ifdef MAC 459 mac_ifnet_create_mbuf(ifp, m); 460 #endif 461 ip = mtod(m, struct ip *); 462 ip->ip_dst = mh->mob_dst; 463 ip->ip_p = mh->mob_proto; 464 ip->ip_sum = 0; 465 ip->ip_len = htons(m->m_pkthdr.len - hlen); 466 if (mh->mob_flags) 467 ip->ip_src = mh->mob_src; 468 memmove(mtodo(m, hlen), ip, sizeof(struct ip)); 469 m_adj(m, hlen); 470 m_clrprotoflags(m); 471 m->m_pkthdr.rcvif = ifp; 472 m->m_pkthdr.csum_flags |= (CSUM_IP_CHECKED | CSUM_IP_VALID); 473 M_SETFIB(m, ifp->if_fib); 474 hlen = AF_INET; 475 BPF_MTAP2(ifp, &hlen, sizeof(hlen), m); 476 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1); 477 if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len); 478 if ((ifp->if_flags & IFF_MONITOR) != 0) 479 m_freem(m); 480 else 481 netisr_dispatch(NETISR_IP, m); 482 return (IPPROTO_DONE); 483 drop: 484 if_inc_counter(ifp, IFCOUNTER_IERRORS, 1); 485 return (IPPROTO_DONE); 486 } 487 488 #define MTAG_ME 1414491977 489 static int 490 me_check_nesting(struct ifnet *ifp, struct mbuf *m) 491 { 492 struct m_tag *mtag; 493 int count; 494 495 count = 1; 496 mtag = NULL; 497 while ((mtag = m_tag_locate(m, MTAG_ME, 0, mtag)) != NULL) { 498 if (*(struct ifnet **)(mtag + 1) == ifp) { 499 log(LOG_NOTICE, "%s: loop detected\n", ifp->if_xname); 500 return (EIO); 501 } 502 count++; 503 } 504 if (count > V_max_me_nesting) { 505 log(LOG_NOTICE, 506 "%s: if_output recursively called too many times(%d)\n", 507 ifp->if_xname, count); 508 return (EIO); 509 } 510 mtag = m_tag_alloc(MTAG_ME, 0, sizeof(struct ifnet *), M_NOWAIT); 511 if (mtag == NULL) 512 return (ENOMEM); 513 *(struct ifnet **)(mtag + 1) = ifp; 514 m_tag_prepend(m, mtag); 515 return (0); 516 } 517 518 static int 519 me_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 520 struct route *ro) 521 { 522 uint32_t af; 523 int error; 524 525 #ifdef MAC 526 error = mac_ifnet_check_transmit(ifp, m); 527 if (error != 0) 528 goto drop; 529 #endif 530 if ((ifp->if_flags & IFF_MONITOR) != 0 || 531 (ifp->if_flags & IFF_UP) == 0) { 532 error = ENETDOWN; 533 goto drop; 534 } 535 536 error = me_check_nesting(ifp, m); 537 if (error != 0) 538 goto drop; 539 540 m->m_flags &= ~(M_BCAST|M_MCAST); 541 if (dst->sa_family == AF_UNSPEC) 542 bcopy(dst->sa_data, &af, sizeof(af)); 543 else 544 af = dst->sa_family; 545 if (af != AF_INET) { 546 error = EAFNOSUPPORT; 547 goto drop; 548 } 549 BPF_MTAP2(ifp, &af, sizeof(af), m); 550 return (ifp->if_transmit(ifp, m)); 551 drop: 552 m_freem(m); 553 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1); 554 return (error); 555 } 556 557 static int 558 me_transmit(struct ifnet *ifp, struct mbuf *m) 559 { 560 ME_RLOCK_TRACKER; 561 struct mobhdr mh; 562 struct me_softc *sc; 563 struct ip *ip; 564 int error, hlen, plen; 565 566 sc = ifp->if_softc; 567 if (sc == NULL) { 568 error = ENETDOWN; 569 m_freem(m); 570 goto drop; 571 } 572 if (m->m_len < sizeof(struct ip)) 573 m = m_pullup(m, sizeof(struct ip)); 574 if (m == NULL) { 575 error = ENOBUFS; 576 goto drop; 577 } 578 ip = mtod(m, struct ip *); 579 /* Fragmented datagramms shouldn't be encapsulated */ 580 if (ip->ip_off & htons(IP_MF | IP_OFFMASK)) { 581 error = EINVAL; 582 m_freem(m); 583 goto drop; 584 } 585 mh.mob_proto = ip->ip_p; 586 mh.mob_src = ip->ip_src; 587 mh.mob_dst = ip->ip_dst; 588 ME_RLOCK(sc); 589 if (!ME_READY(sc)) { 590 ME_RUNLOCK(sc); 591 error = ENETDOWN; 592 m_freem(m); 593 goto drop; 594 } 595 if (in_hosteq(sc->me_src, ip->ip_src)) { 596 hlen = sizeof(struct mobhdr) - sizeof(struct in_addr); 597 mh.mob_flags = 0; 598 } else { 599 hlen = sizeof(struct mobhdr); 600 mh.mob_flags = MOB_FLAGS_SP; 601 } 602 plen = m->m_pkthdr.len; 603 ip->ip_src = sc->me_src; 604 ip->ip_dst = sc->me_dst; 605 M_SETFIB(m, sc->me_fibnum); 606 ME_RUNLOCK(sc); 607 M_PREPEND(m, hlen, M_NOWAIT); 608 if (m == NULL) { 609 error = ENOBUFS; 610 goto drop; 611 } 612 if (m->m_len < sizeof(struct ip) + hlen) 613 m = m_pullup(m, sizeof(struct ip) + hlen); 614 if (m == NULL) { 615 error = ENOBUFS; 616 goto drop; 617 } 618 memmove(mtod(m, void *), mtodo(m, hlen), sizeof(struct ip)); 619 ip = mtod(m, struct ip *); 620 ip->ip_len = htons(m->m_pkthdr.len); 621 ip->ip_p = IPPROTO_MOBILE; 622 ip->ip_sum = 0; 623 mh.mob_csum = 0; 624 mh.mob_csum = me_in_cksum((uint16_t *)&mh, hlen / sizeof(uint16_t)); 625 bcopy(&mh, mtodo(m, sizeof(struct ip)), hlen); 626 error = ip_output(m, NULL, NULL, IP_FORWARDING, NULL, NULL); 627 drop: 628 if (error) 629 if_inc_counter(ifp, IFCOUNTER_OERRORS, 1); 630 else { 631 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); 632 if_inc_counter(ifp, IFCOUNTER_OBYTES, plen); 633 } 634 return (error); 635 } 636 637 static void 638 me_qflush(struct ifnet *ifp __unused) 639 { 640 641 } 642 643 static int 644 memodevent(module_t mod, int type, void *data) 645 { 646 647 switch (type) { 648 case MOD_LOAD: 649 case MOD_UNLOAD: 650 break; 651 default: 652 return (EOPNOTSUPP); 653 } 654 return (0); 655 } 656 657 static moduledata_t me_mod = { 658 "if_me", 659 memodevent, 660 0 661 }; 662 663 DECLARE_MODULE(if_me, me_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 664 MODULE_VERSION(if_me, 1); 665