sys/netinet/in_gif.c

   1 /*
   2  * $FreeBSD: src/sys/netinet/in_gif.c,v 1.5.2.11 2003/01/23 21:06:45 sam Exp $
   3  * $DragonFly: src/sys/netinet/in_gif.c,v 1.16 2006/12/22 23:57:52 swildner Exp $
   4  * $KAME: in_gif.c,v 1.54 2001/05/14 14:02:16 itojun Exp $
   5  */
   6 /*
   7  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   8  * All rights reserved.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  * 3. Neither the name of the project nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #include "opt_inet.h"
  36 #include "opt_inet6.h"
  37
  38 #include <sys/param.h>
  39 #include <sys/systm.h>
  40 #include <sys/socket.h>
  41 #include <sys/sockio.h>
  42 #include <sys/mbuf.h>
  43 #include <sys/errno.h>
  44 #include <sys/kernel.h>
  45 #include <sys/sysctl.h>
  46 #include <sys/protosw.h>
  47
  48 #include <sys/malloc.h>
  49
  50 #include <machine/stdarg.h>
  51
  52 #include <net/if.h>
  53 #include <net/route.h>
  54
  55 #include <netinet/in.h>
  56 #include <netinet/in_systm.h>
  57 #include <netinet/ip.h>
  58 #include <netinet/ip_var.h>
  59 #include <netinet/in_gif.h>
  60 #include <netinet/in_var.h>
  61 #include <netinet/ip_encap.h>
  62 #include <netinet/ip_ecn.h>
  63
  64 #ifdef INET6
  65 #include <netinet/ip6.h>
  66 #endif
  67
  68 #include <net/gif/if_gif.h>
  69 #include <net/net_osdep.h>
  70
  71 #include <sys/thread2.h>        /* ipstat */
  72
  73 #ifdef INET
  74 static int gif_validate4 (const struct ip *, struct gif_softc *,
  75                           struct ifnet *);
  76
  77 extern  struct domain inetdomain;
  78 const struct protosw in_gif_protosw =
  79 { SOCK_RAW,     &inetdomain,    0/*IPPROTO_IPV[46]*/,   PR_ATOMIC|PR_ADDR,
  80   in_gif_input, rip_output,     0,      rip_ctloutput,
  81   cpu0_soport,
  82   0,            0,              0,              0,
  83   &rip_usrreqs
  84 };
  85
  86 int ip_gif_ttl = GIF_TTL;
  87 SYSCTL_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW,
  88         &ip_gif_ttl,    0, "");
  89
  90 int
  91 in_gif_output(struct ifnet *ifp, int family, struct mbuf *m)
  92 {
  93         struct gif_softc *sc = (struct gif_softc*)ifp;
  94         struct sockaddr_in *dst = (struct sockaddr_in *)&sc->gif_ro.ro_dst;
  95         struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc;
  96         struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst;
  97         struct ip iphdr;        /* capsule IP header, host byte ordered */
  98         int proto, error;
  99         u_int8_t tos;
 100
 101         if (sin_src == NULL || sin_dst == NULL ||
 102             sin_src->sin_family != AF_INET ||
 103             sin_dst->sin_family != AF_INET) {
 104                 m_freem(m);
 105                 return EAFNOSUPPORT;
 106         }
 107
 108         switch (family) {
 109 #ifdef INET
 110         case AF_INET:
 111             {
 112                 struct ip *ip;
 113
 114                 proto = IPPROTO_IPV4;
 115                 if (m->m_len < sizeof *ip) {
 116                         m = m_pullup(m, sizeof *ip);
 117                         if (!m)
 118                                 return ENOBUFS;
 119                 }
 120                 ip = mtod(m, struct ip *);
 121                 tos = ip->ip_tos;
 122                 break;
 123             }
 124 #endif
 125 #ifdef INET6
 126         case AF_INET6:
 127             {
 128                 struct ip6_hdr *ip6;
 129                 proto = IPPROTO_IPV6;
 130                 if (m->m_len < sizeof *ip6) {
 131                         m = m_pullup(m, sizeof *ip6);
 132                         if (!m)
 133                                 return ENOBUFS;
 134                 }
 135                 ip6 = mtod(m, struct ip6_hdr *);
 136                 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
 137                 break;
 138             }
 139 #endif
 140         default:
 141 #ifdef DEBUG
 142                 kprintf("in_gif_output: warning: unknown family %d passed\n",
 143                         family);
 144 #endif
 145                 m_freem(m);
 146                 return EAFNOSUPPORT;
 147         }
 148
 149         bzero(&iphdr, sizeof iphdr);
 150         iphdr.ip_src = sin_src->sin_addr;
 151         /* bidirectional configured tunnel mode */
 152         if (sin_dst->sin_addr.s_addr != INADDR_ANY)
 153                 iphdr.ip_dst = sin_dst->sin_addr;
 154         else {
 155                 m_freem(m);
 156                 return ENETUNREACH;
 157         }
 158         iphdr.ip_p = proto;
 159         /* version will be set in ip_output() */
 160         iphdr.ip_ttl = ip_gif_ttl;
 161         iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip);
 162         if (ifp->if_flags & IFF_LINK1)
 163                 ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos);
 164         else
 165                 ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos);
 166
 167         /* prepend new IP header */
 168         M_PREPEND(m, sizeof(struct ip), MB_DONTWAIT);
 169         if (m && m->m_len < sizeof(struct ip))
 170                 m = m_pullup(m, sizeof(struct ip));
 171         if (m == NULL) {
 172                 kprintf("ENOBUFS in in_gif_output %d\n", __LINE__);
 173                 return ENOBUFS;
 174         }
 175         bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip));
 176
 177         if (dst->sin_family != sin_dst->sin_family ||
 178             dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) {
 179                 /* cache route doesn't match */
 180                 dst->sin_family = sin_dst->sin_family;
 181                 dst->sin_len = sizeof(struct sockaddr_in);
 182                 dst->sin_addr = sin_dst->sin_addr;
 183                 if (sc->gif_ro.ro_rt != NULL) {
 184                         RTFREE(sc->gif_ro.ro_rt);
 185                         sc->gif_ro.ro_rt = NULL;
 186                 }
 187 #if 0
 188                 sc->gif_if.if_mtu = GIF_MTU;
 189 #endif
 190         }
 191
 192         if (sc->gif_ro.ro_rt == NULL) {
 193                 rtalloc(&sc->gif_ro);
 194                 if (sc->gif_ro.ro_rt == NULL) {
 195                         m_freem(m);
 196                         return ENETUNREACH;
 197                 }
 198
 199                 /* if it constitutes infinite encapsulation, punt. */
 200                 if (sc->gif_ro.ro_rt->rt_ifp == ifp) {
 201                         m_freem(m);
 202                         return ENETUNREACH;     /* XXX */
 203                 }
 204 #if 0
 205                 ifp->if_mtu = sc->gif_ro.ro_rt->rt_ifp->if_mtu -
 206                     sizeof(struct ip);
 207 #endif
 208         }
 209
 210         error = ip_output(m, NULL, &sc->gif_ro, 0, NULL, NULL);
 211         return(error);
 212 }
 213
 214 void
 215 in_gif_input(struct mbuf *m, ...)
 216 {
 217         struct ifnet *gifp = NULL;
 218         struct ip *ip;
 219         int af;
 220         u_int8_t otos;
 221         int off, proto;
 222         __va_list ap;
 223
 224         __va_start(ap, m);
 225         off = __va_arg(ap, int);
 226         proto = __va_arg(ap, int);
 227         __va_end(ap);
 228
 229         ip = mtod(m, struct ip *);
 230
 231         gifp = (struct ifnet *)encap_getarg(m);
 232
 233         if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
 234                 m_freem(m);
 235                 ipstat.ips_nogif++;
 236                 return;
 237         }
 238
 239         otos = ip->ip_tos;
 240         m_adj(m, off);
 241
 242         switch (proto) {
 243 #ifdef INET
 244         case IPPROTO_IPV4:
 245             {
 246                 struct ip *ip;
 247                 af = AF_INET;
 248                 if (m->m_len < sizeof *ip) {
 249                         m = m_pullup(m, sizeof *ip);
 250                         if (!m)
 251                                 return;
 252                 }
 253                 ip = mtod(m, struct ip *);
 254                 if (gifp->if_flags & IFF_LINK1)
 255                         ip_ecn_egress(ECN_ALLOWED, &otos, &ip->ip_tos);
 256                 else
 257                         ip_ecn_egress(ECN_NOCARE, &otos, &ip->ip_tos);
 258                 break;
 259             }
 260 #endif
 261 #ifdef INET6
 262         case IPPROTO_IPV6:
 263             {
 264                 struct ip6_hdr *ip6;
 265                 u_int8_t itos;
 266                 af = AF_INET6;
 267                 if (m->m_len < sizeof *ip6) {
 268                         m = m_pullup(m, sizeof *ip6);
 269                         if (!m)
 270                                 return;
 271                 }
 272                 ip6 = mtod(m, struct ip6_hdr *);
 273                 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
 274                 if (gifp->if_flags & IFF_LINK1)
 275                         ip_ecn_egress(ECN_ALLOWED, &otos, &itos);
 276                 else
 277                         ip_ecn_egress(ECN_NOCARE, &otos, &itos);
 278                 ip6->ip6_flow &= ~htonl(0xff << 20);
 279                 ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
 280                 break;
 281             }
 282 #endif /* INET6 */
 283         default:
 284                 ipstat.ips_nogif++;
 285                 m_freem(m);
 286                 return;
 287         }
 288         gif_input(m, af, gifp);
 289         return;
 290 }
 291
 292 /*
 293  * validate outer address.
 294  */
 295 static int
 296 gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp)
 297 {
 298         struct sockaddr_in *src, *dst;
 299         struct in_ifaddr *ia4;
 300
 301         src = (struct sockaddr_in *)sc->gif_psrc;
 302         dst = (struct sockaddr_in *)sc->gif_pdst;
 303
 304         /* check for address match */
 305         if (src->sin_addr.s_addr != ip->ip_dst.s_addr ||
 306             dst->sin_addr.s_addr != ip->ip_src.s_addr)
 307                 return 0;
 308
 309         /* martian filters on outer source - NOT done in ip_input! */
 310         if (IN_MULTICAST(ntohl(ip->ip_src.s_addr)))
 311                 return 0;
 312         switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) {
 313         case 0: case 127: case 255:
 314                 return 0;
 315         }
 316         /* reject packets with broadcast on source */
 317         TAILQ_FOREACH(ia4, &in_ifaddrhead, ia_link) {
 318                 if (!(ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST))
 319                         continue;
 320                 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr)
 321                         return 0;
 322         }
 323
 324         /* ingress filters on outer source */
 325         if (!(sc->gif_if.if_flags & IFF_LINK2) && ifp != NULL) {
 326                 struct sockaddr_in sin;
 327                 struct rtentry *rt;
 328
 329                 bzero(&sin, sizeof sin);
 330                 sin.sin_family = AF_INET;
 331                 sin.sin_len = sizeof(struct sockaddr_in);
 332                 sin.sin_addr = ip->ip_src;
 333                 rt = rtpurelookup((struct sockaddr *)&sin);
 334                 if (rt != NULL)
 335                         --rt->rt_refcnt;
 336                 if (rt == NULL || rt->rt_ifp != ifp) {
 337 #if 0
 338                         log(LOG_WARNING, "%s: packet from 0x%x dropped "
 339                             "due to ingress filter\n", if_name(&sc->gif_if),
 340                             (u_int32_t)ntohl(sin.sin_addr.s_addr));
 341 #endif
 342                         return 0;
 343                 }
 344         }
 345
 346         return 32 * 2;
 347 }
 348
 349 /*
 350  * we know that we are in IFF_UP, outer address available, and outer family
 351  * matched the physical addr family.  see gif_encapcheck().
 352  */
 353 int
 354 gif_encapcheck4(const struct mbuf *m, int off, int proto, void *arg)
 355 {
 356         struct ip ip;
 357         struct gif_softc *sc;
 358         struct ifnet *ifp;
 359
 360         /* sanity check done in caller */
 361         sc = (struct gif_softc *)arg;
 362
 363         /* LINTED const cast */
 364         m_copydata(__DECONST(struct mbuf *, m), 0, sizeof ip, (caddr_t)&ip);
 365         ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
 366
 367         return gif_validate4(&ip, sc, ifp);
 368 }
 369
 370 int
 371 in_gif_attach(struct gif_softc *sc)
 372 {
 373         sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck,
 374             &in_gif_protosw, sc);
 375         if (sc->encap_cookie4 == NULL)
 376                 return EEXIST;
 377         return 0;
 378 }
 379
 380 int
 381 in_gif_detach(struct gif_softc *sc)
 382 {
 383         int error;
 384
 385         error = encap_detach(sc->encap_cookie4);
 386         if (error == 0)
 387                 sc->encap_cookie4 = NULL;
 388         return error;
 389 }
 390
 391 #endif /* INET */