bsd/net/if_stf.c

   1 /*      $FreeBSD: src/sys/net/if_stf.c,v 1.1.2.6 2001/07/24 19:10:18 brooks Exp $       */
   2 /*      $KAME: if_stf.c,v 1.62 2001/06/07 22:32:16 itojun Exp $ */
   3
   4 /*
   5  * Copyright (C) 2000 WIDE Project.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the project nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32 /*
  33  * NOTICE: This file was modified by SPARTA, Inc. in 2006 to introduce
  34  * support for mandatory and extensible security protections.  This notice
  35  * is included in support of clause 2.2 (b) of the Apple Public License,
  36  * Version 2.0.
  37  */
  38
  39 /*
  40  * 6to4 interface, based on RFC3056.
  41  *
  42  * 6to4 interface is NOT capable of link-layer (I mean, IPv4) multicasting.
  43  * There is no address mapping defined from IPv6 multicast address to IPv4
  44  * address.  Therefore, we do not have IFF_MULTICAST on the interface.
  45  *
  46  * Due to the lack of address mapping for link-local addresses, we cannot
  47  * throw packets toward link-local addresses (fe80::x).  Also, we cannot throw
  48  * packets to link-local multicast addresses (ff02::x).
  49  *
  50  * Here are interesting symptoms due to the lack of link-local address:
  51  *
  52  * Unicast routing exchange:
  53  * - RIPng: Impossible.  Uses link-local multicast packet toward ff02::9,
  54  *   and link-local addresses as nexthop.
  55  * - OSPFv6: Impossible.  OSPFv6 assumes that there's link-local address
  56  *   assigned to the link, and makes use of them.  Also, HELLO packets use
  57  *   link-local multicast addresses (ff02::5 and ff02::6).
  58  * - BGP4+: Maybe.  You can only use global address as nexthop, and global
  59  *   address as TCP endpoint address.
  60  *
  61  * Multicast routing protocols:
  62  * - PIM: Hello packet cannot be used to discover adjacent PIM routers.
  63  *   Adjacent PIM routers must be configured manually (is it really spec-wise
  64  *   correct thing to do?).
  65  *
  66  * ICMPv6:
  67  * - Redirects cannot be used due to the lack of link-local address.
  68  *
  69  * stf interface does not have, and will not need, a link-local address.
  70  * It seems to have no real benefit and does not help the above symptoms much.
  71  * Even if we assign link-locals to interface, we cannot really
  72  * use link-local unicast/multicast on top of 6to4 cloud (since there's no
  73  * encapsulation defined for link-local address), and the above analysis does
  74  * not change.  RFC3056 does not mandate the assignment of link-local address
  75  * either.
  76  *
  77  * 6to4 interface has security issues.  Refer to
  78  * http://playground.iijlab.net/i-d/draft-itojun-ipv6-transition-abuse-00.txt
  79  * for details.  The code tries to filter out some of malicious packets.
  80  * Note that there is no way to be 100% secure.
  81  */
  82
  83 #include <sys/param.h>
  84 #include <sys/systm.h>
  85 #include <sys/socket.h>
  86 #include <sys/sockio.h>
  87 #include <sys/mbuf.h>
  88 #include <sys/errno.h>
  89 #include <sys/protosw.h>
  90 #include <sys/kernel.h>
  91 #include <sys/syslog.h>
  92
  93 #include <sys/malloc.h>
  94
  95 #include <net/if.h>
  96 #include <net/route.h>
  97 #include <net/if_types.h>
  98
  99 #include <netinet/in.h>
 100 #include <netinet/in_systm.h>
 101 #include <netinet/ip.h>
 102 #include <netinet/ip_var.h>
 103 #include <netinet/in_var.h>
 104
 105 #include <netinet/ip6.h>
 106 #include <netinet6/ip6_var.h>
 107 #include <netinet6/in6_var.h>
 108 #include <netinet/ip_ecn.h>
 109
 110 #include <netinet/ip_encap.h>
 111 #include <net/kpi_interface.h>
 112 #include <net/kpi_protocol.h>
 113
 114
 115 #include <net/net_osdep.h>
 116
 117 #include <net/bpf.h>
 118
 119 #if CONFIG_MACF_NET
 120 #include <security/mac_framework.h>
 121 #endif
 122
 123 #define IN6_IS_ADDR_6TO4(x)     (ntohs((x)->s6_addr16[0]) == 0x2002)
 124 #define GET_V4(x)       ((const struct in_addr *)(&(x)->s6_addr16[1]))
 125
 126 struct stf_softc {
 127         ifnet_t                         sc_if;     /* common area */
 128         u_long                          sc_protocol_family; /* dlil protocol attached */
 129         union {
 130                 struct route  __sc_ro4;
 131                 struct route_in6 __sc_ro6; /* just for safety */
 132         } __sc_ro46;
 133 #define sc_ro   __sc_ro46.__sc_ro4
 134         const struct encaptab *encap_cookie;
 135         bpf_tap_mode            tap_mode;
 136         bpf_packet_func         tap_callback;
 137 };
 138
 139 void stfattach (void);
 140
 141 static int ip_stf_ttl = 40;
 142
 143 static void in_stf_input(struct mbuf *, int);
 144 extern  struct domain inetdomain;
 145 struct protosw in_stf_protosw =
 146 { SOCK_RAW,     &inetdomain,    IPPROTO_IPV6,   PR_ATOMIC|PR_ADDR,
 147   in_stf_input, NULL,   NULL,           rip_ctloutput,
 148   NULL,
 149   NULL,         NULL,   NULL,   NULL,
 150   NULL,
 151   &rip_usrreqs,
 152   NULL,         rip_unlock,     NULL, {NULL, NULL}, NULL, {0}
 153 };
 154
 155 static int stf_encapcheck(const struct mbuf *, int, int, void *);
 156 static struct in6_ifaddr *stf_getsrcifa6(struct ifnet *);
 157 int stf_pre_output(struct ifnet *, protocol_family_t, struct mbuf **,
 158         const struct sockaddr *, void *, char *, char *);
 159 static int stf_checkaddr4(struct stf_softc *, const struct in_addr *,
 160         struct ifnet *);
 161 static int stf_checkaddr6(struct stf_softc *, struct in6_addr *,
 162         struct ifnet *);
 163 static void stf_rtrequest(int, struct rtentry *, struct sockaddr *);
 164 static errno_t stf_ioctl(ifnet_t ifp, u_int32_t cmd, void *data);
 165 static errno_t stf_output(ifnet_t ifp, mbuf_t m);
 166
 167 /*
 168  * gif_input is the input handler for IP and IPv6 attached to gif
 169  */
 170 static errno_t
 171 stf_media_input(
 172         __unused ifnet_t        ifp,
 173         protocol_family_t       protocol_family,
 174         mbuf_t                          m,
 175         __unused char           *frame_header)
 176 {
 177         proto_input(protocol_family, m);
 178
 179         return (0);
 180 }
 181
 182
 183
 184 static errno_t
 185 stf_add_proto(
 186         ifnet_t                                                                 ifp,
 187         protocol_family_t                                               protocol_family,
 188         __unused const struct ifnet_demux_desc  *demux_array,
 189         __unused u_int32_t                                              demux_count)
 190 {
 191         /* Only one protocol may be attached at a time */
 192         struct stf_softc* stf = ifnet_softc(ifp);
 193         if (stf->sc_protocol_family == 0)
 194                 stf->sc_protocol_family = protocol_family;
 195         else {
 196                 printf("stf_add_proto: stf already has a proto\n");
 197                 return EBUSY;
 198         }
 199
 200         return 0;
 201 }
 202
 203 static errno_t
 204 stf_del_proto(
 205         ifnet_t                         ifp,
 206         protocol_family_t       protocol_family)
 207 {
 208         if (((struct stf_softc*)ifnet_softc(ifp))->sc_protocol_family == protocol_family)
 209                 ((struct stf_softc*)ifnet_softc(ifp))->sc_protocol_family = 0;
 210
 211         return 0;
 212 }
 213
 214 static errno_t
 215 stf_attach_inet6(
 216         ifnet_t                         ifp,
 217         protocol_family_t       protocol_family)
 218 {
 219     struct ifnet_attach_proto_param     reg;
 220     errno_t                                                     stat;
 221
 222     if (protocol_family != PF_INET6)
 223         return EPROTONOSUPPORT;
 224
 225         bzero(&reg, sizeof(reg));
 226     reg.input = stf_media_input;
 227     reg.pre_output = stf_pre_output;
 228
 229     stat = ifnet_attach_protocol(ifp, protocol_family, &reg);
 230     if (stat && stat != EEXIST) {
 231         printf("stf_attach_proto_family can't attach interface fam=%d\n",
 232                    protocol_family);
 233     }
 234
 235     return stat;
 236 }
 237
 238 static errno_t
 239 stf_demux(
 240         ifnet_t                                 ifp,
 241         __unused mbuf_t                 m,
 242         __unused char                   *frame_ptr,
 243         protocol_family_t               *protocol_family)
 244 {
 245         struct stf_softc* stf = ifnet_softc(ifp);
 246         *protocol_family = stf->sc_protocol_family;
 247         return 0;
 248 }
 249
 250 static errno_t
 251 stf_set_bpf_tap(
 252         ifnet_t                 ifp,
 253         bpf_tap_mode    mode,
 254         bpf_packet_func callback)
 255 {
 256         struct stf_softc        *sc = ifnet_softc(ifp);
 257
 258         sc->tap_mode = mode;
 259         sc->tap_callback = callback;
 260
 261         return 0;
 262 }
 263
 264 void
 265 stfattach(void)
 266 {
 267         struct stf_softc *sc;
 268         int error;
 269         const struct encaptab *p;
 270         struct ifnet_init_params        stf_init;
 271
 272         error = proto_register_plumber(PF_INET6, APPLE_IF_FAM_STF,
 273                                                                    stf_attach_inet6, NULL);
 274         if (error != 0)
 275                 printf("proto_register_plumber failed for AF_INET6 error=%d\n", error);
 276
 277         sc = _MALLOC(sizeof(struct stf_softc), M_DEVBUF, M_WAITOK);
 278         if (sc == 0) {
 279                 printf("stf softc attach failed\n" );
 280                 return;
 281         }
 282
 283         bzero(sc, sizeof(*sc));
 284
 285         p = encap_attach_func(AF_INET, IPPROTO_IPV6, stf_encapcheck,
 286             &in_stf_protosw, sc);
 287         if (p == NULL) {
 288                 printf("sftattach encap_attach_func failed\n");
 289                 FREE(sc, M_DEVBUF);
 290                 return;
 291         }
 292         sc->encap_cookie = p;
 293
 294         bzero(&stf_init, sizeof(stf_init));
 295         stf_init.name = "stf";
 296         stf_init.unit = 0;
 297         stf_init.type = IFT_STF;
 298         stf_init.family = IFNET_FAMILY_STF;
 299         stf_init.output = stf_output;
 300         stf_init.demux = stf_demux;
 301         stf_init.add_proto = stf_add_proto;
 302         stf_init.del_proto = stf_del_proto;
 303         stf_init.softc = sc;
 304         stf_init.ioctl = stf_ioctl;
 305         stf_init.set_bpf_tap = stf_set_bpf_tap;
 306
 307         error = ifnet_allocate(&stf_init, &sc->sc_if);
 308         if (error != 0) {
 309                 printf("stfattach, ifnet_allocate failed - %d\n", error);
 310                 encap_detach(sc->encap_cookie);
 311                 FREE(sc, M_DEVBUF);
 312                 return;
 313         }
 314         ifnet_set_mtu(sc->sc_if, IPV6_MMTU);
 315         ifnet_set_flags(sc->sc_if, 0, 0xffff); /* clear all flags */
 316 #if 0
 317         /* turn off ingress filter */
 318         ifnet_set_flags(sc->sc_if, IFF_LINK2, IFF_LINK2);
 319 #endif
 320
 321 #if CONFIG_MACF_NET
 322         mac_ifnet_label_init(&sc->sc_if);
 323 #endif
 324
 325         error = ifnet_attach(sc->sc_if, NULL);
 326         if (error != 0) {
 327                 printf("stfattach: ifnet_attach returned error=%d\n", error);
 328                 encap_detach(sc->encap_cookie);
 329                 ifnet_release(sc->sc_if);
 330                 FREE(sc, M_DEVBUF);
 331                 return;
 332         }
 333
 334         bpfattach(sc->sc_if, DLT_NULL, sizeof(u_int));
 335
 336         return;
 337 }
 338
 339 static int
 340 stf_encapcheck(
 341         const struct mbuf *m,
 342         __unused int off,
 343         int proto,
 344         void *arg)
 345 {
 346         struct ip ip;
 347         struct in6_ifaddr *ia6;
 348         struct stf_softc *sc;
 349         struct in_addr a, b;
 350
 351         sc = (struct stf_softc *)arg;
 352         if (sc == NULL)
 353                 return 0;
 354
 355         if ((ifnet_flags(sc->sc_if) & IFF_UP) == 0)
 356                 return 0;
 357
 358         /* IFF_LINK0 means "no decapsulation" */
 359         if ((ifnet_flags(sc->sc_if) & IFF_LINK0) != 0)
 360                 return 0;
 361
 362         if (proto != IPPROTO_IPV6)
 363                 return 0;
 364
 365         /* LINTED const cast */
 366         mbuf_copydata(m, 0, sizeof(ip), &ip);
 367
 368         if (ip.ip_v != 4)
 369                 return 0;
 370
 371         ia6 = stf_getsrcifa6(sc->sc_if);
 372         if (ia6 == NULL)
 373                 return 0;
 374
 375         /*
 376          * check if IPv4 dst matches the IPv4 address derived from the
 377          * local 6to4 address.
 378          * success on: dst = 10.1.1.1, ia6->ia_addr = 2002:0a01:0101:...
 379          */
 380         if (bcmp(GET_V4(&ia6->ia_addr.sin6_addr), &ip.ip_dst,
 381             sizeof(ip.ip_dst)) != 0)
 382                 return 0;
 383
 384         /*
 385          * check if IPv4 src matches the IPv4 address derived from the
 386          * local 6to4 address masked by prefixmask.
 387          * success on: src = 10.1.1.1, ia6->ia_addr = 2002:0a00:.../24
 388          * fail on: src = 10.1.1.1, ia6->ia_addr = 2002:0b00:.../24
 389          */
 390         bzero(&a, sizeof(a));
 391         a.s_addr = GET_V4(&ia6->ia_addr.sin6_addr)->s_addr;
 392         a.s_addr &= GET_V4(&ia6->ia_prefixmask.sin6_addr)->s_addr;
 393         b = ip.ip_src;
 394         b.s_addr &= GET_V4(&ia6->ia_prefixmask.sin6_addr)->s_addr;
 395         if (a.s_addr != b.s_addr)
 396                 return 0;
 397
 398         /* stf interface makes single side match only */
 399         return 32;
 400 }
 401
 402 static struct in6_ifaddr *
 403 stf_getsrcifa6(struct ifnet *ifp)
 404 {
 405         struct ifaddr *ia;
 406         struct in_ifaddr *ia4;
 407         struct sockaddr_in6 *sin6;
 408         struct in_addr in;
 409
 410         ifnet_lock_shared(ifp);
 411         for (ia = ifp->if_addrlist.tqh_first;
 412              ia;
 413              ia = ia->ifa_list.tqe_next)
 414         {
 415                 if (ia->ifa_addr == NULL)
 416                         continue;
 417                 if (ia->ifa_addr->sa_family != AF_INET6)
 418                         continue;
 419                 sin6 = (struct sockaddr_in6 *)ia->ifa_addr;
 420                 if (!IN6_IS_ADDR_6TO4(&sin6->sin6_addr))
 421                         continue;
 422
 423                 bcopy(GET_V4(&sin6->sin6_addr), &in, sizeof(in));
 424                 lck_mtx_lock(rt_mtx);
 425                 for (ia4 = TAILQ_FIRST(&in_ifaddrhead);
 426                      ia4;
 427                      ia4 = TAILQ_NEXT(ia4, ia_link))
 428                 {
 429                         if (ia4->ia_addr.sin_addr.s_addr == in.s_addr)
 430                                 break;
 431                 }
 432                 lck_mtx_unlock(rt_mtx);
 433                 if (ia4 == NULL)
 434                         continue;
 435
 436                 ifnet_lock_done(ifp);
 437                 return (struct in6_ifaddr *)ia;
 438         }
 439         ifnet_lock_done(ifp);
 440
 441         return NULL;
 442 }
 443
 444 int
 445 stf_pre_output(
 446         struct ifnet    *ifp,
 447         __unused protocol_family_t  protocol_family,
 448         struct mbuf     **m0,
 449         const struct sockaddr   *dst,
 450         __unused void *route,
 451         __unused char *desk_linkaddr,
 452         __unused char *frame_type)
 453 {
 454         struct mbuf *m = *m0;
 455         struct stf_softc *sc;
 456         const struct sockaddr_in6 *dst6;
 457         const struct in_addr *in4;
 458         u_int8_t tos;
 459         struct ip *ip;
 460         struct ip6_hdr *ip6;
 461         struct in6_ifaddr *ia6;
 462         struct sockaddr_in      *dst4;
 463         errno_t                         result = 0;
 464
 465         sc = ifnet_softc(ifp);
 466         dst6 = (const struct sockaddr_in6 *)dst;
 467
 468         /* just in case */
 469         if ((ifnet_flags(ifp) & IFF_UP) == 0) {
 470                 printf("stf: IFF_DOWN\n");
 471                 return ENETDOWN;
 472         }
 473
 474         /*
 475          * If we don't have an ip4 address that match my inner ip6 address,
 476          * we shouldn't generate output.  Without this check, we'll end up
 477          * using wrong IPv4 source.
 478          */
 479         ia6 = stf_getsrcifa6(ifp);
 480         if (ia6 == NULL) {
 481                 return ENETDOWN;
 482         }
 483
 484         if (mbuf_len(m) < sizeof(*ip6)) {
 485                 m = m_pullup(m, sizeof(*ip6));
 486                 if (!m) {
 487                         *m0 = NULL; /* makes sure this won't be double freed */
 488                         return ENOBUFS;
 489                 }
 490         }
 491         ip6 = mtod(m, struct ip6_hdr *);
 492         tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
 493
 494         /*
 495          * Pickup the right outer dst addr from the list of candidates.
 496          * ip6_dst has priority as it may be able to give us shorter IPv4 hops.
 497          */
 498         if (IN6_IS_ADDR_6TO4(&ip6->ip6_dst))
 499                 in4 = GET_V4(&ip6->ip6_dst);
 500         else if (IN6_IS_ADDR_6TO4(&dst6->sin6_addr))
 501                 in4 = GET_V4(&dst6->sin6_addr);
 502         else {
 503                 return ENETUNREACH;
 504         }
 505
 506         if (ifp->if_bpf) {
 507                 /* We need to prepend the address family as a four byte field. */
 508                 u_int32_t af = AF_INET6;
 509
 510                 bpf_tap_out(ifp, 0, m, &af, sizeof(af));
 511         }
 512
 513         M_PREPEND(m, sizeof(struct ip), M_DONTWAIT);
 514         if (m && mbuf_len(m) < sizeof(struct ip))
 515                 m = m_pullup(m, sizeof(struct ip));
 516         if (m == NULL) {
 517                 *m0 = NULL;
 518                 return ENOBUFS;
 519         }
 520         ip = mtod(m, struct ip *);
 521
 522         bzero(ip, sizeof(*ip));
 523
 524         bcopy(GET_V4(&((struct sockaddr_in6 *)&ia6->ia_addr)->sin6_addr),
 525             &ip->ip_src, sizeof(ip->ip_src));
 526         bcopy(in4, &ip->ip_dst, sizeof(ip->ip_dst));
 527         ip->ip_p = IPPROTO_IPV6;
 528         ip->ip_ttl = ip_stf_ttl;
 529         ip->ip_len = m->m_pkthdr.len;   /*host order*/
 530         if (ifp->if_flags & IFF_LINK1)
 531                 ip_ecn_ingress(ECN_ALLOWED, &ip->ip_tos, &tos);
 532         else
 533                 ip_ecn_ingress(ECN_NOCARE, &ip->ip_tos, &tos);
 534
 535         dst4 = (struct sockaddr_in *)&sc->sc_ro.ro_dst;
 536         if (dst4->sin_family != AF_INET ||
 537             bcmp(&dst4->sin_addr, &ip->ip_dst, sizeof(ip->ip_dst)) != 0) {
 538                 /* cache route doesn't match */
 539                 printf("stf_output: cached route doesn't match \n");
 540                 dst4->sin_family = AF_INET;
 541                 dst4->sin_len = sizeof(struct sockaddr_in);
 542                 bcopy(&ip->ip_dst, &dst4->sin_addr, sizeof(dst4->sin_addr));
 543                 if (sc->sc_ro.ro_rt) {
 544                         rtfree(sc->sc_ro.ro_rt);
 545                         sc->sc_ro.ro_rt = NULL;
 546                 }
 547         }
 548
 549         if (sc->sc_ro.ro_rt == NULL) {
 550                 rtalloc(&sc->sc_ro);
 551                 if (sc->sc_ro.ro_rt == NULL) {
 552                         return ENETUNREACH;
 553                 }
 554         }
 555
 556         result = ip_output_list(m, 0, NULL, &sc->sc_ro, 0, NULL, NULL);
 557         /* Assumption: ip_output will free mbuf on errors */
 558         /* All the output processing is done here, don't let stf_output be called */
 559         if (result == 0)
 560                 result = EJUSTRETURN;
 561         *m0 = NULL;
 562         return result;
 563 }
 564 static errno_t
 565 stf_output(
 566         __unused ifnet_t        ifp,
 567         __unused mbuf_t m)
 568 {
 569         /* All processing is done in stf_pre_output
 570          * this shouldn't be called as the pre_output returns "EJUSTRETURN"
 571          */
 572         return 0;
 573 }
 574
 575 static int
 576 stf_checkaddr4(
 577         struct stf_softc *sc,
 578         const struct in_addr *in,
 579         struct ifnet *inifp)    /* incoming interface */
 580 {
 581         struct in_ifaddr *ia4;
 582
 583         /*
 584          * reject packets with the following address:
 585          * 224.0.0.0/4 0.0.0.0/8 127.0.0.0/8 255.0.0.0/8
 586          */
 587         if (IN_MULTICAST(ntohl(in->s_addr)))
 588                 return -1;
 589         switch ((ntohl(in->s_addr) & 0xff000000) >> 24) {
 590         case 0: case 127: case 255:
 591                 return -1;
 592         }
 593
 594         /*
 595          * reject packets with broadcast
 596          */
 597         lck_mtx_lock(rt_mtx);
 598         for (ia4 = TAILQ_FIRST(&in_ifaddrhead);
 599              ia4;
 600              ia4 = TAILQ_NEXT(ia4, ia_link))
 601         {
 602                 if ((ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST) == 0)
 603                         continue;
 604                 if (in->s_addr == ia4->ia_broadaddr.sin_addr.s_addr) {
 605                         lck_mtx_unlock(rt_mtx);
 606                         return -1;
 607                 }
 608         }
 609         lck_mtx_unlock(rt_mtx);
 610
 611         /*
 612          * perform ingress filter
 613          */
 614         if (sc && (ifnet_flags(sc->sc_if) & IFF_LINK2) == 0 && inifp) {
 615                 struct sockaddr_in sin;
 616                 struct rtentry *rt;
 617
 618                 bzero(&sin, sizeof(sin));
 619                 sin.sin_family = AF_INET;
 620                 sin.sin_len = sizeof(struct sockaddr_in);
 621                 sin.sin_addr = *in;
 622                 rt = rtalloc1((struct sockaddr *)&sin, 0, 0UL);
 623                 if (!rt || rt->rt_ifp != inifp) {
 624 #if 1
 625                         log(LOG_WARNING, "%s: packet from 0x%x dropped "
 626                             "due to ingress filter\n", if_name(sc->sc_if),
 627                             (u_int32_t)ntohl(sin.sin_addr.s_addr));
 628 #endif
 629                         if (rt)
 630                                 rtfree(rt);
 631                         return -1;
 632                 }
 633                 rtfree(rt);
 634         }
 635
 636         return 0;
 637 }
 638
 639 static int
 640 stf_checkaddr6(
 641         struct stf_softc *sc,
 642         struct in6_addr *in6,
 643         struct ifnet *inifp)    /* incoming interface */
 644 {
 645         /*
 646          * check 6to4 addresses
 647          */
 648         if (IN6_IS_ADDR_6TO4(in6))
 649                 return stf_checkaddr4(sc, GET_V4(in6), inifp);
 650
 651         /*
 652          * reject anything that look suspicious.  the test is implemented
 653          * in ip6_input too, but we check here as well to
 654          * (1) reject bad packets earlier, and
 655          * (2) to be safe against future ip6_input change.
 656          */
 657         if (IN6_IS_ADDR_V4COMPAT(in6) || IN6_IS_ADDR_V4MAPPED(in6))
 658                 return -1;
 659
 660         return 0;
 661 }
 662
 663 static void
 664 in_stf_input(
 665         struct mbuf *m,
 666         int off)
 667 {
 668         struct stf_softc *sc;
 669         struct ip *ip;
 670         struct ip6_hdr ip6;
 671         u_int8_t otos, itos;
 672         int proto;
 673         struct ifnet *ifp;
 674         struct ifnet_stat_increment_param       stats;
 675
 676         ip = mtod(m, struct ip *);
 677         proto = ip->ip_p;
 678
 679         if (proto != IPPROTO_IPV6) {
 680                 m_freem(m);
 681                 return;
 682         }
 683
 684         ip = mtod(m, struct ip *);
 685
 686         sc = (struct stf_softc *)encap_getarg(m);
 687
 688         if (sc == NULL || (ifnet_flags(sc->sc_if) & IFF_UP) == 0) {
 689                 m_freem(m);
 690                 return;
 691         }
 692
 693         ifp = sc->sc_if;
 694
 695 #if MAC_LABEL
 696         mac_mbuf_label_associate_ifnet(ifp, m);
 697 #endif
 698
 699         /*
 700          * perform sanity check against outer src/dst.
 701          * for source, perform ingress filter as well.
 702          */
 703         if (stf_checkaddr4(sc, &ip->ip_dst, NULL) < 0 ||
 704             stf_checkaddr4(sc, &ip->ip_src, m->m_pkthdr.rcvif) < 0) {
 705                 m_freem(m);
 706                 return;
 707         }
 708
 709         otos = ip->ip_tos;
 710         mbuf_copydata(m, off, sizeof(ip6), &ip6);
 711
 712         /*
 713          * perform sanity check against inner src/dst.
 714          * for source, perform ingress filter as well.
 715          */
 716         if (stf_checkaddr6(sc, &ip6.ip6_dst, NULL) < 0 ||
 717             stf_checkaddr6(sc, &ip6.ip6_src, m->m_pkthdr.rcvif) < 0) {
 718                 m_freem(m);
 719                 return;
 720         }
 721
 722         itos = (ntohl(ip6.ip6_flow) >> 20) & 0xff;
 723         if ((ifnet_flags(ifp) & IFF_LINK1) != 0)
 724                 ip_ecn_egress(ECN_ALLOWED, &otos, &itos);
 725         else
 726                 ip_ecn_egress(ECN_NOCARE, &otos, &itos);
 727         ip6.ip6_flow &= ~htonl(0xff << 20);
 728         ip6.ip6_flow |= htonl((u_int32_t)itos << 20);
 729
 730         m->m_pkthdr.rcvif = ifp;
 731         mbuf_pkthdr_setheader(m, mbuf_data(m));
 732         mbuf_adj(m, off);
 733
 734         if (ifp->if_bpf) {
 735                 /* We need to prepend the address family as a four byte field. */
 736                 u_int32_t af = AF_INET6;
 737                 bpf_tap_in(ifp, 0, m, &af, sizeof(af));
 738         }
 739
 740         /*
 741          * Put the packet to the network layer input queue according to the
 742          * specified address family.
 743          * See net/if_gif.c for possible issues with packet processing
 744          * reorder due to extra queueing.
 745          */
 746         bzero(&stats, sizeof(stats));
 747         stats.packets_in = 1;
 748         stats.bytes_in = mbuf_pkthdr_len(m);
 749         mbuf_pkthdr_setrcvif(m, ifp);
 750         ifnet_input(ifp, m, &stats);
 751
 752         return;
 753 }
 754
 755 static void
 756 stf_rtrequest(
 757         __unused int cmd,
 758         struct rtentry *rt,
 759         __unused struct sockaddr *sa)
 760 {
 761
 762         if (rt)
 763                 rt->rt_rmx.rmx_mtu = IPV6_MMTU;
 764 }
 765
 766 static errno_t
 767 stf_ioctl(
 768         ifnet_t         ifp,
 769         u_int32_t       cmd,
 770         void            *data)
 771 {
 772         struct ifaddr *ifa;
 773         struct ifreq *ifr;
 774         struct sockaddr_in6 *sin6;
 775         int error;
 776
 777         error = 0;
 778         switch (cmd) {
 779         case SIOCSIFADDR:
 780                 ifa = (struct ifaddr *)data;
 781                 if (ifa == NULL || ifa->ifa_addr->sa_family != AF_INET6) {
 782                         error = EAFNOSUPPORT;
 783                         break;
 784                 }
 785                 sin6 = (struct sockaddr_in6 *)ifa->ifa_addr;
 786                 if (IN6_IS_ADDR_6TO4(&sin6->sin6_addr)) {
 787                         if ( !(ifnet_flags( ifp ) & IFF_UP) ) {
 788                                 /* do this only if the interface is not already up */
 789                                 ifa->ifa_rtrequest = stf_rtrequest;
 790                                 ifnet_set_flags(ifp, IFF_UP, IFF_UP);
 791                         }
 792                 } else
 793                         error = EINVAL;
 794                 break;
 795
 796         case SIOCADDMULTI:
 797         case SIOCDELMULTI:
 798                 ifr = (struct ifreq *)data;
 799                 if (ifr && ifr->ifr_addr.sa_family == AF_INET6)
 800                         ;
 801                 else
 802                         error = EAFNOSUPPORT;
 803                 break;
 804
 805         default:
 806                 error = EINVAL;
 807                 break;
 808         }
 809
 810         return error;
 811 }