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  * $KAME: in_gif.c,v 1.54 2001/05/14 14:02:16 itojun Exp $
   4  */
   5 /*
   6  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the name of the project nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include "opt_inet.h"
  35 #include "opt_inet6.h"
  36
  37 #include <sys/param.h>
  38 #include <sys/systm.h>
  39 #include <sys/socket.h>
  40 #include <sys/sockio.h>
  41 #include <sys/mbuf.h>
  42 #include <sys/errno.h>
  43 #include <sys/kernel.h>
  44 #include <sys/sysctl.h>
  45 #include <sys/protosw.h>
  46
  47 #include <sys/malloc.h>
  48
  49 #include <machine/stdarg.h>
  50
  51 #include <net/if.h>
  52 #include <net/route.h>
  53
  54 #include <netinet/in.h>
  55 #include <netinet/in_systm.h>
  56 #include <netinet/ip.h>
  57 #include <netinet/ip_var.h>
  58 #include <netinet/in_gif.h>
  59 #include <netinet/in_var.h>
  60 #include <netinet/ip_encap.h>
  61 #include <netinet/ip_ecn.h>
  62
  63 #ifdef INET6
  64 #include <netinet/ip6.h>
  65 #endif
  66
  67 #include <net/gif/if_gif.h>
  68 #include <net/net_osdep.h>
  69
  70 #include <sys/thread2.h>        /* ipstat */
  71
  72 #ifdef INET
  73 static int gif_validate4 (const struct ip *, struct gif_softc *,
  74                           struct ifnet *);
  75
  76 extern  struct domain inetdomain;
  77 const struct protosw in_gif_protosw =
  78     {
  79         .pr_type = SOCK_RAW,
  80         .pr_domain = &inetdomain,
  81         .pr_protocol = 0 /*IPPROTO_IPV[46]*/,
  82         .pr_flags = PR_ATOMIC|PR_ADDR,
  83
  84         .pr_input = in_gif_input,
  85         .pr_output = rip_output,
  86         .pr_ctlinput = NULL,
  87         .pr_ctloutput = rip_ctloutput,
  88
  89         .pr_ctlport = NULL,
  90         .pr_usrreqs = &rip_usrreqs
  91     };
  92
  93 int ip_gif_ttl = GIF_TTL;
  94 SYSCTL_INT(_net_inet_ip, IPCTL_GIF_TTL, gifttl, CTLFLAG_RW,
  95         &ip_gif_ttl, 0, "TTL of GIF packet");
  96
  97 int
  98 in_gif_output(struct ifnet *ifp, int family, struct mbuf *m)
  99 {
 100         struct gif_softc *sc = (struct gif_softc*)ifp;
 101         struct route *ro = &sc->gif_ro[mycpu->gd_cpuid];
 102         struct sockaddr_in *dst = (struct sockaddr_in *)&ro->ro_dst;
 103         struct sockaddr_in *sin_src = (struct sockaddr_in *)sc->gif_psrc;
 104         struct sockaddr_in *sin_dst = (struct sockaddr_in *)sc->gif_pdst;
 105         struct ip iphdr;        /* capsule IP header, host byte ordered */
 106         int proto, error;
 107         u_int8_t tos;
 108
 109         if (sin_src == NULL || sin_dst == NULL ||
 110             sin_src->sin_family != AF_INET ||
 111             sin_dst->sin_family != AF_INET) {
 112                 m_freem(m);
 113                 return EAFNOSUPPORT;
 114         }
 115
 116         switch (family) {
 117 #ifdef INET
 118         case AF_INET:
 119             {
 120                 struct ip *ip;
 121
 122                 proto = IPPROTO_IPV4;
 123                 if (m->m_len < sizeof *ip) {
 124                         m = m_pullup(m, sizeof *ip);
 125                         if (!m)
 126                                 return ENOBUFS;
 127                 }
 128                 ip = mtod(m, struct ip *);
 129                 tos = ip->ip_tos;
 130                 break;
 131             }
 132 #endif
 133 #ifdef INET6
 134         case AF_INET6:
 135             {
 136                 struct ip6_hdr *ip6;
 137                 proto = IPPROTO_IPV6;
 138                 if (m->m_len < sizeof *ip6) {
 139                         m = m_pullup(m, sizeof *ip6);
 140                         if (!m)
 141                                 return ENOBUFS;
 142                 }
 143                 ip6 = mtod(m, struct ip6_hdr *);
 144                 tos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
 145                 break;
 146             }
 147 #endif
 148         default:
 149 #ifdef DEBUG
 150                 kprintf("in_gif_output: warning: unknown family %d passed\n",
 151                         family);
 152 #endif
 153                 m_freem(m);
 154                 return EAFNOSUPPORT;
 155         }
 156
 157         bzero(&iphdr, sizeof iphdr);
 158         iphdr.ip_src = sin_src->sin_addr;
 159         /* bidirectional configured tunnel mode */
 160         if (sin_dst->sin_addr.s_addr != INADDR_ANY)
 161                 iphdr.ip_dst = sin_dst->sin_addr;
 162         else {
 163                 m_freem(m);
 164                 return ENETUNREACH;
 165         }
 166         iphdr.ip_p = proto;
 167         /* version will be set in ip_output() */
 168         iphdr.ip_ttl = ip_gif_ttl;
 169         iphdr.ip_len = m->m_pkthdr.len + sizeof(struct ip);
 170         if (ifp->if_flags & IFF_LINK1)
 171                 ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos);
 172         else
 173                 ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos);
 174
 175         /* prepend new IP header */
 176         M_PREPEND(m, sizeof(struct ip), M_NOWAIT);
 177         if (m && m->m_len < sizeof(struct ip))
 178                 m = m_pullup(m, sizeof(struct ip));
 179         if (m == NULL) {
 180                 kprintf("ENOBUFS in in_gif_output %d\n", __LINE__);
 181                 return ENOBUFS;
 182         }
 183         bcopy(&iphdr, mtod(m, struct ip *), sizeof(struct ip));
 184
 185         if (dst->sin_family != sin_dst->sin_family ||
 186             dst->sin_addr.s_addr != sin_dst->sin_addr.s_addr) {
 187                 /* cache route doesn't match */
 188                 dst->sin_family = sin_dst->sin_family;
 189                 dst->sin_len = sizeof(struct sockaddr_in);
 190                 dst->sin_addr = sin_dst->sin_addr;
 191                 if (ro->ro_rt != NULL) {
 192                         RTFREE(ro->ro_rt);
 193                         ro->ro_rt = NULL;
 194                 }
 195 #if 0
 196                 sc->gif_if.if_mtu = GIF_MTU;
 197 #endif
 198         }
 199
 200         if (ro->ro_rt == NULL) {
 201                 rtalloc(ro);
 202                 if (ro->ro_rt == NULL) {
 203                         m_freem(m);
 204                         return ENETUNREACH;
 205                 }
 206
 207                 /* if it constitutes infinite encapsulation, punt. */
 208                 if (ro->ro_rt->rt_ifp == ifp) {
 209                         m_freem(m);
 210                         return ENETUNREACH;     /* XXX */
 211                 }
 212 #if 0
 213                 ifp->if_mtu = ro->ro_rt->rt_ifp->if_mtu - sizeof(struct ip);
 214 #endif
 215         }
 216
 217         error = ip_output(m, NULL, ro, 0, NULL, NULL);
 218         return(error);
 219 }
 220
 221 int
 222 in_gif_input(struct mbuf **mp, int *offp, int proto)
 223 {
 224         struct mbuf *m = *mp;
 225         struct ifnet *gifp = NULL;
 226         struct ip *ip;
 227         int af;
 228         u_int8_t otos;
 229         int off;
 230
 231         off = *offp;
 232         *mp = NULL;
 233
 234         ip = mtod(m, struct ip *);
 235
 236         gifp = (struct ifnet *)encap_getarg(m);
 237
 238         if (gifp == NULL || (gifp->if_flags & IFF_UP) == 0) {
 239                 m_freem(m);
 240                 ipstat.ips_nogif++;
 241                 return(IPPROTO_DONE);
 242         }
 243
 244         otos = ip->ip_tos;
 245         m_adj(m, off);
 246
 247         switch (proto) {
 248 #ifdef INET
 249         case IPPROTO_IPV4:
 250             {
 251                 struct ip *ip;
 252                 af = AF_INET;
 253                 if (m->m_len < sizeof *ip) {
 254                         m = m_pullup(m, sizeof *ip);
 255                         if (!m)
 256                                 return(IPPROTO_DONE);
 257                 }
 258                 ip = mtod(m, struct ip *);
 259                 if (gifp->if_flags & IFF_LINK1)
 260                         ip_ecn_egress(ECN_ALLOWED, &otos, &ip->ip_tos);
 261                 else
 262                         ip_ecn_egress(ECN_NOCARE, &otos, &ip->ip_tos);
 263                 break;
 264             }
 265 #endif
 266 #ifdef INET6
 267         case IPPROTO_IPV6:
 268             {
 269                 struct ip6_hdr *ip6;
 270                 u_int8_t itos;
 271                 af = AF_INET6;
 272                 if (m->m_len < sizeof *ip6) {
 273                         m = m_pullup(m, sizeof *ip6);
 274                         if (!m)
 275                                 return(IPPROTO_DONE);
 276                 }
 277                 ip6 = mtod(m, struct ip6_hdr *);
 278                 itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
 279                 if (gifp->if_flags & IFF_LINK1)
 280                         ip_ecn_egress(ECN_ALLOWED, &otos, &itos);
 281                 else
 282                         ip_ecn_egress(ECN_NOCARE, &otos, &itos);
 283                 ip6->ip6_flow &= ~htonl(0xff << 20);
 284                 ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
 285                 break;
 286             }
 287 #endif /* INET6 */
 288         default:
 289                 ipstat.ips_nogif++;
 290                 m_freem(m);
 291                 return(IPPROTO_DONE);
 292         }
 293         gif_input(m, af, gifp);
 294         return(IPPROTO_DONE);
 295 }
 296
 297 /*
 298  * validate outer address.
 299  */
 300 static int
 301 gif_validate4(const struct ip *ip, struct gif_softc *sc, struct ifnet *ifp)
 302 {
 303         struct sockaddr_in *src, *dst;
 304         struct in_ifaddr_container *iac;
 305
 306         src = (struct sockaddr_in *)sc->gif_psrc;
 307         dst = (struct sockaddr_in *)sc->gif_pdst;
 308
 309         /* check for address match */
 310         if (src->sin_addr.s_addr != ip->ip_dst.s_addr ||
 311             dst->sin_addr.s_addr != ip->ip_src.s_addr)
 312                 return 0;
 313
 314         /* martian filters on outer source - NOT done in ip_input! */
 315         if (IN_MULTICAST(ntohl(ip->ip_src.s_addr)))
 316                 return 0;
 317         switch ((ntohl(ip->ip_src.s_addr) & 0xff000000) >> 24) {
 318         case 0: case 127: case 255:
 319                 return 0;
 320         }
 321         /* reject packets with broadcast on source */
 322         TAILQ_FOREACH(iac, &in_ifaddrheads[mycpuid], ia_link) {
 323                 struct in_ifaddr *ia4 = iac->ia;
 324
 325                 if (!(ia4->ia_ifa.ifa_ifp->if_flags & IFF_BROADCAST))
 326                         continue;
 327                 if (ip->ip_src.s_addr == ia4->ia_broadaddr.sin_addr.s_addr)
 328                         return 0;
 329         }
 330
 331         /* ingress filters on outer source */
 332         if (!(sc->gif_if.if_flags & IFF_LINK2) && ifp != NULL) {
 333                 struct sockaddr_in sin;
 334                 struct rtentry *rt;
 335
 336                 bzero(&sin, sizeof sin);
 337                 sin.sin_family = AF_INET;
 338                 sin.sin_len = sizeof(struct sockaddr_in);
 339                 sin.sin_addr = ip->ip_src;
 340                 rt = rtpurelookup((struct sockaddr *)&sin);
 341                 if (rt != NULL)
 342                         --rt->rt_refcnt;
 343                 if (rt == NULL || rt->rt_ifp != ifp) {
 344 #if 0
 345                         log(LOG_WARNING, "%s: packet from 0x%x dropped "
 346                             "due to ingress filter\n", if_name(&sc->gif_if),
 347                             (u_int32_t)ntohl(sin.sin_addr.s_addr));
 348 #endif
 349                         return 0;
 350                 }
 351         }
 352
 353         return 32 * 2;
 354 }
 355
 356 /*
 357  * we know that we are in IFF_UP, outer address available, and outer family
 358  * matched the physical addr family.  see gif_encapcheck().
 359  */
 360 int
 361 gif_encapcheck4(const struct mbuf *m, int off, int proto, void *arg)
 362 {
 363         struct ip ip;
 364         struct gif_softc *sc;
 365         struct ifnet *ifp;
 366
 367         /* sanity check done in caller */
 368         sc = (struct gif_softc *)arg;
 369
 370         /* LINTED const cast */
 371         m_copydata(__DECONST(struct mbuf *, m), 0, sizeof ip, (caddr_t)&ip);
 372         ifp = ((m->m_flags & M_PKTHDR) != 0) ? m->m_pkthdr.rcvif : NULL;
 373
 374         return gif_validate4(&ip, sc, ifp);
 375 }
 376
 377 int
 378 in_gif_attach(struct gif_softc *sc)
 379 {
 380         sc->encap_cookie4 = encap_attach_func(AF_INET, -1, gif_encapcheck,
 381             &in_gif_protosw, sc);
 382         if (sc->encap_cookie4 == NULL)
 383                 return EEXIST;
 384         return 0;
 385 }
 386
 387 int
 388 in_gif_detach(struct gif_softc *sc)
 389 {
 390         int error;
 391
 392         error = encap_detach(sc->encap_cookie4);
 393         if (error == 0)
 394                 sc->encap_cookie4 = NULL;
 395         return error;
 396 }
 397
 398 #endif /* INET */