target/linux/generic-2.6/patches/160-netfilter_route.patch

   1 Index: linux-2.6.21.7/include/linux/netfilter_ipv4/ipt_ROUTE.h
   2 ===================================================================
   3 --- /dev/null
   4 +++ linux-2.6.21.7/include/linux/netfilter_ipv4/ipt_ROUTE.h
   5 @@ -0,0 +1,23 @@
   6 +/* Header file for iptables ipt_ROUTE target
   7 + *
   8 + * (C) 2002 by Cédric de Launois <delaunois@info.ucl.ac.be>
   9 + *
  10 + * This software is distributed under GNU GPL v2, 1991
  11 + */
  12 +#ifndef _IPT_ROUTE_H_target
  13 +#define _IPT_ROUTE_H_target
  14 +
  15 +#define IPT_ROUTE_IFNAMSIZ 16
  16 +
  17 +struct ipt_route_target_info {
  18 +       char      oif[IPT_ROUTE_IFNAMSIZ];      /* Output Interface Name */
  19 +       char      iif[IPT_ROUTE_IFNAMSIZ];      /* Input Interface Name  */
  20 +       u_int32_t gw;                           /* IP address of gateway */
  21 +       u_int8_t  flags;
  22 +};
  23 +
  24 +/* Values for "flags" field */
  25 +#define IPT_ROUTE_CONTINUE        0x01
  26 +#define IPT_ROUTE_TEE             0x02
  27 +
  28 +#endif /*_IPT_ROUTE_H_target*/
  29 Index: linux-2.6.21.7/include/linux/netfilter_ipv6/ip6t_ROUTE.h
  30 ===================================================================
  31 --- /dev/null
  32 +++ linux-2.6.21.7/include/linux/netfilter_ipv6/ip6t_ROUTE.h
  33 @@ -0,0 +1,23 @@
  34 +/* Header file for iptables ip6t_ROUTE target
  35 + *
  36 + * (C) 2003 by Cédric de Launois <delaunois@info.ucl.ac.be>
  37 + *
  38 + * This software is distributed under GNU GPL v2, 1991
  39 + */
  40 +#ifndef _IPT_ROUTE_H_target
  41 +#define _IPT_ROUTE_H_target
  42 +
  43 +#define IP6T_ROUTE_IFNAMSIZ 16
  44 +
  45 +struct ip6t_route_target_info {
  46 +       char      oif[IP6T_ROUTE_IFNAMSIZ];     /* Output Interface Name */
  47 +       char      iif[IP6T_ROUTE_IFNAMSIZ];     /* Input Interface Name  */
  48 +       u_int32_t gw[4];                        /* IPv6 address of gateway */
  49 +       u_int8_t  flags;
  50 +};
  51 +
  52 +/* Values for "flags" field */
  53 +#define IP6T_ROUTE_CONTINUE        0x01
  54 +#define IP6T_ROUTE_TEE             0x02
  55 +
  56 +#endif /*_IP6T_ROUTE_H_target*/
  57 Index: linux-2.6.21.7/net/ipv4/netfilter/ipt_ROUTE.c
  58 ===================================================================
  59 --- /dev/null
  60 +++ linux-2.6.21.7/net/ipv4/netfilter/ipt_ROUTE.c
  61 @@ -0,0 +1,483 @@
  62 +/*
  63 + * This implements the ROUTE target, which enables you to setup unusual
  64 + * routes not supported by the standard kernel routing table.
  65 + *
  66 + * Copyright (C) 2002 Cedric de Launois <delaunois@info.ucl.ac.be>
  67 + *
  68 + * v 1.11 2004/11/23
  69 + *
  70 + * This software is distributed under GNU GPL v2, 1991
  71 + */
  72 +
  73 +#include <linux/module.h>
  74 +#include <linux/skbuff.h>
  75 +#include <linux/ip.h>
  76 +#include <linux/netfilter_ipv4/ip_tables.h>
  77 +#include <linux/netfilter_ipv4/ip_conntrack.h>
  78 +#include <linux/netfilter_ipv4/ipt_ROUTE.h>
  79 +#include <linux/netdevice.h>
  80 +#include <linux/route.h>
  81 +#include <linux/version.h>
  82 +#include <linux/if_arp.h>
  83 +#include <net/ip.h>
  84 +#include <net/route.h>
  85 +#include <net/icmp.h>
  86 +#include <net/checksum.h>
  87 +
  88 +#if 0
  89 +#define DEBUGP printk
  90 +#else
  91 +#define DEBUGP(format, args...)
  92 +#endif
  93 +
  94 +MODULE_LICENSE("GPL");
  95 +MODULE_AUTHOR("Cedric de Launois <delaunois@info.ucl.ac.be>");
  96 +MODULE_DESCRIPTION("iptables ROUTE target module");
  97 +
  98 +/* Try to route the packet according to the routing keys specified in
  99 + * route_info. Keys are :
 100 + *  - ifindex :
 101 + *      0 if no oif preferred,
 102 + *      otherwise set to the index of the desired oif
 103 + *  - route_info->gw :
 104 + *      0 if no gateway specified,
 105 + *      otherwise set to the next host to which the pkt must be routed
 106 + * If success, skb->dev is the output device to which the packet must
 107 + * be sent and skb->dst is not NULL
 108 + *
 109 + * RETURN: -1 if an error occured
 110 + *          1 if the packet was succesfully routed to the
 111 + *            destination desired
 112 + *          0 if the kernel routing table could not route the packet
 113 + *            according to the keys specified
 114 + */
 115 +static int route(struct sk_buff *skb,
 116 +                unsigned int ifindex,
 117 +                const struct ipt_route_target_info *route_info)
 118 +{
 119 +       int err;
 120 +       struct rtable *rt;
 121 +       struct iphdr *iph = skb->nh.iph;
 122 +       struct flowi fl = {
 123 +               .oif = ifindex,
 124 +               .nl_u = {
 125 +                       .ip4_u = {
 126 +                               .daddr = iph->daddr,
 127 +                               .saddr = 0,
 128 +                               .tos = RT_TOS(iph->tos),
 129 +                               .scope = RT_SCOPE_UNIVERSE,
 130 +                       }
 131 +               }
 132 +       };
 133 +
 134 +       /* The destination address may be overloaded by the target */
 135 +       if (route_info->gw)
 136 +               fl.fl4_dst = route_info->gw;
 137 +
 138 +       /* Trying to route the packet using the standard routing table. */
 139 +       if ((err = ip_route_output_key(&rt, &fl))) {
 140 +               if (net_ratelimit())
 141 +                       DEBUGP("ipt_ROUTE: couldn't route pkt (err: %i)",err);
 142 +               return -1;
 143 +       }
 144 +
 145 +       /* Drop old route. */
 146 +       dst_release(skb->dst);
 147 +       skb->dst = NULL;
 148 +
 149 +       /* Success if no oif specified or if the oif correspond to the
 150 +        * one desired */
 151 +       if (!ifindex || rt->u.dst.dev->ifindex == ifindex) {
 152 +               skb->dst = &rt->u.dst;
 153 +               skb->dev = skb->dst->dev;
 154 +               skb->protocol = htons(ETH_P_IP);
 155 +               return 1;
 156 +       }
 157 +
 158 +       /* The interface selected by the routing table is not the one
 159 +        * specified by the user. This may happen because the dst address
 160 +        * is one of our own addresses.
 161 +        */
 162 +       if (net_ratelimit())
 163 +               DEBUGP("ipt_ROUTE: failed to route as desired gw=%u.%u.%u.%u oif=%i (got oif=%i)\n",
 164 +                      NIPQUAD(route_info->gw), ifindex, rt->u.dst.dev->ifindex);
 165 +
 166 +       return 0;
 167 +}
 168 +
 169 +
 170 +/* Stolen from ip_finish_output2
 171 + * PRE : skb->dev is set to the device we are leaving by
 172 + *       skb->dst is not NULL
 173 + * POST: the packet is sent with the link layer header pushed
 174 + *       the packet is destroyed
 175 + */
 176 +static void ip_direct_send(struct sk_buff *skb)
 177 +{
 178 +       struct dst_entry *dst = skb->dst;
 179 +       struct hh_cache *hh = dst->hh;
 180 +       struct net_device *dev = dst->dev;
 181 +       int hh_len = LL_RESERVED_SPACE(dev);
 182 +
 183 +       /* Be paranoid, rather than too clever. */
 184 +       if (unlikely(skb_headroom(skb) < hh_len && dev->hard_header)) {
 185 +               struct sk_buff *skb2;
 186 +
 187 +               skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev));
 188 +               if (skb2 == NULL) {
 189 +                       kfree_skb(skb);
 190 +                       return;
 191 +               }
 192 +               if (skb->sk)
 193 +                       skb_set_owner_w(skb2, skb->sk);
 194 +               kfree_skb(skb);
 195 +               skb = skb2;
 196 +       }
 197 +
 198 +       if (hh) {
 199 +               int hh_alen;
 200 +
 201 +               read_lock_bh(&hh->hh_lock);
 202 +               hh_alen = HH_DATA_ALIGN(hh->hh_len);
 203 +               memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
 204 +               read_unlock_bh(&hh->hh_lock);
 205 +               skb_push(skb, hh->hh_len);
 206 +               hh->hh_output(skb);
 207 +       } else if (dst->neighbour)
 208 +               dst->neighbour->output(skb);
 209 +       else {
 210 +               if (net_ratelimit())
 211 +                       DEBUGP(KERN_DEBUG "ipt_ROUTE: no hdr & no neighbour cache!\n");
 212 +               kfree_skb(skb);
 213 +       }
 214 +}
 215 +
 216 +
 217 +/* PRE : skb->dev is set to the device we are leaving by
 218 + * POST: - the packet is directly sent to the skb->dev device, without
 219 + *         pushing the link layer header.
 220 + *       - the packet is destroyed
 221 + */
 222 +static inline int dev_direct_send(struct sk_buff *skb)
 223 +{
 224 +       return dev_queue_xmit(skb);
 225 +}
 226 +
 227 +
 228 +static unsigned int route_oif(const struct ipt_route_target_info *route_info,
 229 +                             struct sk_buff *skb)
 230 +{
 231 +       unsigned int ifindex = 0;
 232 +       struct net_device *dev_out = NULL;
 233 +
 234 +       /* The user set the interface name to use.
 235 +        * Getting the current interface index.
 236 +        */
 237 +       if ((dev_out = dev_get_by_name(route_info->oif))) {
 238 +               ifindex = dev_out->ifindex;
 239 +       } else {
 240 +               /* Unknown interface name : packet dropped */
 241 +               if (net_ratelimit())
 242 +                       DEBUGP("ipt_ROUTE: oif interface %s not found\n", route_info->oif);
 243 +               return NF_DROP;
 244 +       }
 245 +
 246 +       /* Trying the standard way of routing packets */
 247 +       switch (route(skb, ifindex, route_info)) {
 248 +       case 1:
 249 +               dev_put(dev_out);
 250 +               if (route_info->flags & IPT_ROUTE_CONTINUE)
 251 +                       return IPT_CONTINUE;
 252 +
 253 +               ip_direct_send(skb);
 254 +               return NF_STOLEN;
 255 +
 256 +       case 0:
 257 +               /* Failed to send to oif. Trying the hard way */
 258 +               if (route_info->flags & IPT_ROUTE_CONTINUE)
 259 +                       return NF_DROP;
 260 +
 261 +               if (net_ratelimit())
 262 +                       DEBUGP("ipt_ROUTE: forcing the use of %i\n",
 263 +                              ifindex);
 264 +
 265 +               /* We have to force the use of an interface.
 266 +                * This interface must be a tunnel interface since
 267 +                * otherwise we can't guess the hw address for
 268 +                * the packet. For a tunnel interface, no hw address
 269 +                * is needed.
 270 +                */
 271 +               if ((dev_out->type != ARPHRD_TUNNEL)
 272 +                   && (dev_out->type != ARPHRD_IPGRE)) {
 273 +                       if (net_ratelimit())
 274 +                               DEBUGP("ipt_ROUTE: can't guess the hw addr !\n");
 275 +                       dev_put(dev_out);
 276 +                       return NF_DROP;
 277 +               }
 278 +
 279 +               /* Send the packet. This will also free skb
 280 +                * Do not go through the POST_ROUTING hook because
 281 +                * skb->dst is not set and because it will probably
 282 +                * get confused by the destination IP address.
 283 +                */
 284 +               skb->dev = dev_out;
 285 +               dev_direct_send(skb);
 286 +               dev_put(dev_out);
 287 +               return NF_STOLEN;
 288 +
 289 +       default:
 290 +               /* Unexpected error */
 291 +               dev_put(dev_out);
 292 +               return NF_DROP;
 293 +       }
 294 +}
 295 +
 296 +
 297 +static unsigned int route_iif(const struct ipt_route_target_info *route_info,
 298 +                             struct sk_buff *skb)
 299 +{
 300 +       struct net_device *dev_in = NULL;
 301 +
 302 +       /* Getting the current interface index. */
 303 +       if (!(dev_in = dev_get_by_name(route_info->iif))) {
 304 +               if (net_ratelimit())
 305 +                       DEBUGP("ipt_ROUTE: iif interface %s not found\n", route_info->iif);
 306 +               return NF_DROP;
 307 +       }
 308 +
 309 +       skb->dev = dev_in;
 310 +       dst_release(skb->dst);
 311 +       skb->dst = NULL;
 312 +
 313 +       netif_rx(skb);
 314 +       dev_put(dev_in);
 315 +       return NF_STOLEN;
 316 +}
 317 +
 318 +
 319 +static unsigned int route_gw(const struct ipt_route_target_info *route_info,
 320 +                            struct sk_buff *skb)
 321 +{
 322 +       if (route(skb, 0, route_info)!=1)
 323 +               return NF_DROP;
 324 +
 325 +       if (route_info->flags & IPT_ROUTE_CONTINUE)
 326 +               return IPT_CONTINUE;
 327 +
 328 +       ip_direct_send(skb);
 329 +       return NF_STOLEN;
 330 +}
 331 +
 332 +
 333 +/* To detect and deter routed packet loopback when using the --tee option,
 334 + * we take a page out of the raw.patch book: on the copied skb, we set up
 335 + * a fake ->nfct entry, pointing to the local &route_tee_track. We skip
 336 + * routing packets when we see they already have that ->nfct.
 337 + */
 338 +
 339 +static struct ip_conntrack route_tee_track;
 340 +
 341 +static unsigned int ipt_route_target(struct sk_buff **pskb,
 342 +                                    const struct net_device *in,
 343 +                                    const struct net_device *out,
 344 +                                    unsigned int hooknum,
 345 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,17)
 346 +                                    const struct xt_target *target,
 347 +#endif
 348 +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19)
 349 +                                    const void *targinfo,
 350 +                                    void *userinfo)
 351 +#else
 352 +                                    const void *targinfo)
 353 +#endif
 354 +{
 355 +       const struct ipt_route_target_info *route_info = targinfo;
 356 +       struct sk_buff *skb = *pskb;
 357 +       unsigned int res;
 358 +
 359 +       if (skb->nfct == &route_tee_track.ct_general) {
 360 +               /* Loopback - a packet we already routed, is to be
 361 +                * routed another time. Avoid that, now.
 362 +                */
 363 +               if (net_ratelimit())
 364 +                       DEBUGP(KERN_DEBUG "ipt_ROUTE: loopback - DROP!\n");
 365 +               return NF_DROP;
 366 +       }
 367 +
 368 +       /* If we are at PREROUTING or INPUT hook
 369 +        * the TTL isn't decreased by the IP stack
 370 +        */
 371 +       if (hooknum == NF_IP_PRE_ROUTING ||
 372 +           hooknum == NF_IP_LOCAL_IN) {
 373 +
 374 +               struct iphdr *iph = skb->nh.iph;
 375 +
 376 +               if (iph->ttl <= 1) {
 377 +                       struct rtable *rt;
 378 +                       struct flowi fl = {
 379 +                               .oif = 0,
 380 +                               .nl_u = {
 381 +                                       .ip4_u = {
 382 +                                               .daddr = iph->daddr,
 383 +                                               .saddr = iph->saddr,
 384 +                                               .tos = RT_TOS(iph->tos),
 385 +                                               .scope = ((iph->tos & RTO_ONLINK) ?
 386 +                                                         RT_SCOPE_LINK :
 387 +                                                         RT_SCOPE_UNIVERSE)
 388 +                                       }
 389 +                               }
 390 +                       };
 391 +
 392 +                       if (ip_route_output_key(&rt, &fl)) {
 393 +                               return NF_DROP;
 394 +                       }
 395 +
 396 +                       if (skb->dev == rt->u.dst.dev) {
 397 +                               /* Drop old route. */
 398 +                               dst_release(skb->dst);
 399 +                               skb->dst = &rt->u.dst;
 400 +
 401 +                               /* this will traverse normal stack, and
 402 +                                * thus call conntrack on the icmp packet */
 403 +                               icmp_send(skb, ICMP_TIME_EXCEEDED,
 404 +                                         ICMP_EXC_TTL, 0);
 405 +                       }
 406 +
 407 +                       return NF_DROP;
 408 +               }
 409 +
 410 +               /*
 411 +                * If we are at INPUT the checksum must be recalculated since
 412 +                * the length could change as the result of a defragmentation.
 413 +                */
 414 +               if(hooknum == NF_IP_LOCAL_IN) {
 415 +                       iph->ttl = iph->ttl - 1;
 416 +                       iph->check = 0;
 417 +                       iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
 418 +               } else {
 419 +                       ip_decrease_ttl(iph);
 420 +               }
 421 +       }
 422 +
 423 +       if ((route_info->flags & IPT_ROUTE_TEE)) {
 424 +               /*
 425 +                * Copy the *pskb, and route the copy. Will later return
 426 +                * IPT_CONTINUE for the original skb, which should continue
 427 +                * on its way as if nothing happened. The copy should be
 428 +                * independantly delivered to the ROUTE --gw.
 429 +                */
 430 +               skb = skb_copy(*pskb, GFP_ATOMIC);
 431 +               if (!skb) {
 432 +                       if (net_ratelimit())
 433 +                               DEBUGP(KERN_DEBUG "ipt_ROUTE: copy failed!\n");
 434 +                       return IPT_CONTINUE;
 435 +               }
 436 +       }
 437 +
 438 +       /* Tell conntrack to forget this packet since it may get confused
 439 +        * when a packet is leaving with dst address == our address.
 440 +        * Good idea ? Dunno. Need advice.
 441 +        *
 442 +        * NEW: mark the skb with our &route_tee_track, so we avoid looping
 443 +        * on any already routed packet.
 444 +        */
 445 +       if (!(route_info->flags & IPT_ROUTE_CONTINUE)) {
 446 +               nf_conntrack_put(skb->nfct);
 447 +               skb->nfct = &route_tee_track.ct_general;
 448 +               skb->nfctinfo = IP_CT_NEW;
 449 +               nf_conntrack_get(skb->nfct);
 450 +       }
 451 +
 452 +       if (route_info->oif[0] != '\0') {
 453 +               res = route_oif(route_info, skb);
 454 +       } else if (route_info->iif[0] != '\0') {
 455 +               res = route_iif(route_info, skb);
 456 +       } else if (route_info->gw) {
 457 +               res = route_gw(route_info, skb);
 458 +       } else {
 459 +               if (net_ratelimit())
 460 +                       DEBUGP(KERN_DEBUG "ipt_ROUTE: no parameter !\n");
 461 +               res = IPT_CONTINUE;
 462 +       }
 463 +
 464 +       if ((route_info->flags & IPT_ROUTE_TEE))
 465 +               res = IPT_CONTINUE;
 466 +
 467 +       return res;
 468 +}
 469 +
 470 +
 471 +static int ipt_route_checkentry(const char *tablename,
 472 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
 473 +                               const void *e,
 474 +#else
 475 +                               const struct ipt_ip *ip,
 476 +#endif
 477 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,17)
 478 +                               const struct xt_target *target,
 479 +#endif
 480 +                               void *targinfo,
 481 +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19)
 482 +                               unsigned int targinfosize,
 483 +#endif
 484 +                               unsigned int hook_mask)
 485 +{
 486 +       if (strcmp(tablename, "mangle") != 0) {
 487 +               printk("ipt_ROUTE: bad table `%s', use the `mangle' table.\n",
 488 +                      tablename);
 489 +               return 0;
 490 +       }
 491 +
 492 +       if (hook_mask & ~(  (1 << NF_IP_PRE_ROUTING)
 493 +                           | (1 << NF_IP_LOCAL_IN)
 494 +                           | (1 << NF_IP_FORWARD)
 495 +                           | (1 << NF_IP_LOCAL_OUT)
 496 +                           | (1 << NF_IP_POST_ROUTING))) {
 497 +               printk("ipt_ROUTE: bad hook\n");
 498 +               return 0;
 499 +       }
 500 +
 501 +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19)
 502 +       if (targinfosize != IPT_ALIGN(sizeof(struct ipt_route_target_info))) {
 503 +               printk(KERN_WARNING "ipt_ROUTE: targinfosize %u != %Zu\n",
 504 +                      targinfosize,
 505 +                      IPT_ALIGN(sizeof(struct ipt_route_target_info)));
 506 +               return 0;
 507 +       }
 508 +#endif
 509 +
 510 +       return 1;
 511 +}
 512 +
 513 +
 514 +static struct ipt_target ipt_route_reg = {
 515 +       .name = "ROUTE",
 516 +       .target = ipt_route_target,
 517 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,17)
 518 +       .targetsize = sizeof(struct ipt_route_target_info),
 519 +#endif
 520 +       .checkentry = ipt_route_checkentry,
 521 +       .me = THIS_MODULE,
 522 +};
 523 +
 524 +static int __init init(void)
 525 +{
 526 +       /* Set up fake conntrack (stolen from raw.patch):
 527 +           - to never be deleted, not in any hashes */
 528 +       atomic_set(&route_tee_track.ct_general.use, 1);
 529 +       /*  - and look it like as a confirmed connection */
 530 +       set_bit(IPS_CONFIRMED_BIT, &route_tee_track.status);
 531 +       /* Initialize fake conntrack so that NAT will skip it */
 532 +       route_tee_track.status |= IPS_NAT_DONE_MASK;
 533 +
 534 +       return xt_register_target(&ipt_route_reg);
 535 +}
 536 +
 537 +
 538 +static void __exit fini(void)
 539 +{
 540 +       xt_unregister_target(&ipt_route_reg);
 541 +}
 542 +
 543 +module_init(init);
 544 +module_exit(fini);
 545 Index: linux-2.6.21.7/net/ipv4/netfilter/Kconfig
 546 ===================================================================
 547 --- linux-2.6.21.7.orig/net/ipv4/netfilter/Kconfig
 548 +++ linux-2.6.21.7/net/ipv4/netfilter/Kconfig
 549 @@ -807,5 +807,22 @@ config IP_NF_TARGET_SET
 550           To compile it as a module, choose M here.  If unsure, say N.
 551
 552
 553 +config IP_NF_TARGET_ROUTE
 554 +       tristate  'ROUTE target support'
 555 +       depends on IP_NF_MANGLE
 556 +       help
 557 +         This option adds a `ROUTE' target, which enables you to setup unusual
 558 +         routes. For example, the ROUTE lets you route a received packet through
 559 +         an interface or towards a host, even if the regular destination of the
 560 +         packet is the router itself. The ROUTE target is also able to change the
 561 +         incoming interface of a packet.
 562 +
 563 +         The target can be or not a final target. It has to be used inside the
 564 +         mangle table.
 565 +
 566 +         If you want to compile it as a module, say M here and read
 567 +         Documentation/modules.txt.  The module will be called ipt_ROUTE.o.
 568 +         If unsure, say `N'.
 569 +
 570  endmenu
 571
 572 Index: linux-2.6.21.7/net/ipv4/netfilter/Makefile
 573 ===================================================================
 574 --- linux-2.6.21.7.orig/net/ipv4/netfilter/Makefile
 575 +++ linux-2.6.21.7/net/ipv4/netfilter/Makefile
 576 @@ -102,6 +102,7 @@ obj-$(CONFIG_IP_NF_TARGET_ECN) += ipt_EC
 577  obj-$(CONFIG_IP_NF_TARGET_IMQ) += ipt_IMQ.o
 578  obj-$(CONFIG_IP_NF_TARGET_MASQUERADE) += ipt_MASQUERADE.o
 579  obj-$(CONFIG_IP_NF_TARGET_REDIRECT) += ipt_REDIRECT.o
 580 +obj-$(CONFIG_IP_NF_TARGET_ROUTE) += ipt_ROUTE.o
 581  obj-$(CONFIG_IP_NF_TARGET_NETMAP) += ipt_NETMAP.o
 582  obj-$(CONFIG_IP_NF_TARGET_SAME) += ipt_SAME.o
 583  obj-$(CONFIG_IP_NF_NAT_SNMP_BASIC) += ip_nat_snmp_basic.o
 584 Index: linux-2.6.21.7/net/ipv6/ipv6_syms.c
 585 ===================================================================
 586 --- linux-2.6.21.7.orig/net/ipv6/ipv6_syms.c
 587 +++ linux-2.6.21.7/net/ipv6/ipv6_syms.c
 588 @@ -10,6 +10,7 @@ EXPORT_SYMBOL(icmpv6_send);
 589  EXPORT_SYMBOL(icmpv6_statistics);
 590  EXPORT_SYMBOL(icmpv6_err_convert);
 591  EXPORT_SYMBOL(ndisc_mc_map);
 592 +EXPORT_SYMBOL(nd_tbl);
 593  EXPORT_SYMBOL(register_inet6addr_notifier);
 594  EXPORT_SYMBOL(unregister_inet6addr_notifier);
 595  EXPORT_SYMBOL(ip6_route_output);
 596 Index: linux-2.6.21.7/net/ipv6/netfilter/ip6t_ROUTE.c
 597 ===================================================================
 598 --- /dev/null
 599 +++ linux-2.6.21.7/net/ipv6/netfilter/ip6t_ROUTE.c
 600 @@ -0,0 +1,330 @@
 601 +/*
 602 + * This implements the ROUTE v6 target, which enables you to setup unusual
 603 + * routes not supported by the standard kernel routing table.
 604 + *
 605 + * Copyright (C) 2003 Cedric de Launois <delaunois@info.ucl.ac.be>
 606 + *
 607 + * v 1.1 2004/11/23
 608 + *
 609 + * This software is distributed under GNU GPL v2, 1991
 610 + */
 611 +
 612 +#include <linux/module.h>
 613 +#include <linux/skbuff.h>
 614 +#include <linux/ipv6.h>
 615 +#include <linux/netfilter_ipv6/ip6_tables.h>
 616 +#include <linux/netfilter_ipv6/ip6t_ROUTE.h>
 617 +#include <linux/netdevice.h>
 618 +#include <linux/version.h>
 619 +#include <net/ipv6.h>
 620 +#include <net/ndisc.h>
 621 +#include <net/ip6_route.h>
 622 +#include <linux/icmpv6.h>
 623 +
 624 +#if 1
 625 +#define DEBUGP printk
 626 +#else
 627 +#define DEBUGP(format, args...)
 628 +#endif
 629 +
 630 +#define NIP6(addr) \
 631 +       ntohs((addr).s6_addr16[0]), \
 632 +       ntohs((addr).s6_addr16[1]), \
 633 +       ntohs((addr).s6_addr16[2]), \
 634 +       ntohs((addr).s6_addr16[3]), \
 635 +       ntohs((addr).s6_addr16[4]), \
 636 +       ntohs((addr).s6_addr16[5]), \
 637 +       ntohs((addr).s6_addr16[6]), \
 638 +       ntohs((addr).s6_addr16[7])
 639 +
 640 +/* Route the packet according to the routing keys specified in
 641 + * route_info. Keys are :
 642 + *  - ifindex :
 643 + *      0 if no oif preferred,
 644 + *      otherwise set to the index of the desired oif
 645 + *  - route_info->gw :
 646 + *      0 if no gateway specified,
 647 + *      otherwise set to the next host to which the pkt must be routed
 648 + * If success, skb->dev is the output device to which the packet must
 649 + * be sent and skb->dst is not NULL
 650 + *
 651 + * RETURN:  1 if the packet was succesfully routed to the
 652 + *            destination desired
 653 + *          0 if the kernel routing table could not route the packet
 654 + *            according to the keys specified
 655 + */
 656 +static int
 657 +route6(struct sk_buff *skb,
 658 +       unsigned int ifindex,
 659 +       const struct ip6t_route_target_info *route_info)
 660 +{
 661 +       struct rt6_info *rt = NULL;
 662 +       struct ipv6hdr *ipv6h = skb->nh.ipv6h;
 663 +       struct in6_addr *gw = (struct in6_addr*)&route_info->gw;
 664 +
 665 +       DEBUGP("ip6t_ROUTE: called with: ");
 666 +       DEBUGP("DST=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(ipv6h->daddr));
 667 +       DEBUGP("GATEWAY=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(*gw));
 668 +       DEBUGP("OUT=%s\n", route_info->oif);
 669 +
 670 +       if (ipv6_addr_any(gw))
 671 +               rt = rt6_lookup(&ipv6h->daddr, &ipv6h->saddr, ifindex, 1);
 672 +       else
 673 +               rt = rt6_lookup(gw, &ipv6h->saddr, ifindex, 1);
 674 +
 675 +       if (!rt)
 676 +               goto no_route;
 677 +
 678 +       DEBUGP("ip6t_ROUTE: routing gives: ");
 679 +       DEBUGP("DST=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(rt->rt6i_dst.addr));
 680 +       DEBUGP("GATEWAY=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(rt->rt6i_gateway));
 681 +       DEBUGP("OUT=%s\n", rt->rt6i_dev->name);
 682 +
 683 +       if (ifindex && rt->rt6i_dev->ifindex!=ifindex)
 684 +               goto wrong_route;
 685 +
 686 +       if (!rt->rt6i_nexthop) {
 687 +               DEBUGP("ip6t_ROUTE: discovering neighbour\n");
 688 +               rt->rt6i_nexthop = ndisc_get_neigh(rt->rt6i_dev, &rt->rt6i_dst.addr);
 689 +       }
 690 +
 691 +       /* Drop old route. */
 692 +       dst_release(skb->dst);
 693 +       skb->dst = &rt->u.dst;
 694 +       skb->dev = rt->rt6i_dev;
 695 +       return 1;
 696 +
 697 + wrong_route:
 698 +       dst_release(&rt->u.dst);
 699 + no_route:
 700 +       if (!net_ratelimit())
 701 +               return 0;
 702 +
 703 +       printk("ip6t_ROUTE: no explicit route found ");
 704 +       if (ifindex)
 705 +               printk("via interface %s ", route_info->oif);
 706 +       if (!ipv6_addr_any(gw))
 707 +               printk("via gateway %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x", NIP6(*gw));
 708 +       printk("\n");
 709 +       return 0;
 710 +}
 711 +
 712 +
 713 +/* Stolen from ip6_output_finish
 714 + * PRE : skb->dev is set to the device we are leaving by
 715 + *       skb->dst is not NULL
 716 + * POST: the packet is sent with the link layer header pushed
 717 + *       the packet is destroyed
 718 + */
 719 +static void ip_direct_send(struct sk_buff *skb)
 720 +{
 721 +       struct dst_entry *dst = skb->dst;
 722 +       struct hh_cache *hh = dst->hh;
 723 +
 724 +       if (hh) {
 725 +               read_lock_bh(&hh->hh_lock);
 726 +               memcpy(skb->data - 16, hh->hh_data, 16);
 727 +               read_unlock_bh(&hh->hh_lock);
 728 +               skb_push(skb, hh->hh_len);
 729 +               hh->hh_output(skb);
 730 +       } else if (dst->neighbour)
 731 +               dst->neighbour->output(skb);
 732 +       else {
 733 +               if (net_ratelimit())
 734 +                       DEBUGP(KERN_DEBUG "ip6t_ROUTE: no hdr & no neighbour cache!\n");
 735 +               kfree_skb(skb);
 736 +       }
 737 +}
 738 +
 739 +
 740 +static unsigned int
 741 +route6_oif(const struct ip6t_route_target_info *route_info,
 742 +          struct sk_buff *skb)
 743 +{
 744 +       unsigned int ifindex = 0;
 745 +       struct net_device *dev_out = NULL;
 746 +
 747 +       /* The user set the interface name to use.
 748 +        * Getting the current interface index.
 749 +        */
 750 +       if ((dev_out = dev_get_by_name(route_info->oif))) {
 751 +               ifindex = dev_out->ifindex;
 752 +       } else {
 753 +               /* Unknown interface name : packet dropped */
 754 +               if (net_ratelimit())
 755 +                       DEBUGP("ip6t_ROUTE: oif interface %s not found\n", route_info->oif);
 756 +
 757 +               if (route_info->flags & IP6T_ROUTE_CONTINUE)
 758 +                       return IP6T_CONTINUE;
 759 +               else
 760 +                       return NF_DROP;
 761 +       }
 762 +
 763 +       /* Trying the standard way of routing packets */
 764 +       if (route6(skb, ifindex, route_info)) {
 765 +               dev_put(dev_out);
 766 +               if (route_info->flags & IP6T_ROUTE_CONTINUE)
 767 +                       return IP6T_CONTINUE;
 768 +
 769 +               ip_direct_send(skb);
 770 +               return NF_STOLEN;
 771 +       } else
 772 +               return NF_DROP;
 773 +}
 774 +
 775 +
 776 +static unsigned int
 777 +route6_gw(const struct ip6t_route_target_info *route_info,
 778 +         struct sk_buff *skb)
 779 +{
 780 +       if (route6(skb, 0, route_info)) {
 781 +               if (route_info->flags & IP6T_ROUTE_CONTINUE)
 782 +                       return IP6T_CONTINUE;
 783 +
 784 +               ip_direct_send(skb);
 785 +               return NF_STOLEN;
 786 +       } else
 787 +               return NF_DROP;
 788 +}
 789 +
 790 +
 791 +static unsigned int
 792 +ip6t_route_target(struct sk_buff **pskb,
 793 +                 const struct net_device *in,
 794 +                 const struct net_device *out,
 795 +                 unsigned int hooknum,
 796 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,17)
 797 +                 const struct xt_target *target,
 798 +#endif
 799 +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19)
 800 +                 const void *targinfo,
 801 +                 void *userinfo)
 802 +#else
 803 +                 const void *targinfo)
 804 +#endif
 805 +{
 806 +       const struct ip6t_route_target_info *route_info = targinfo;
 807 +       struct sk_buff *skb = *pskb;
 808 +       struct in6_addr *gw = (struct in6_addr*)&route_info->gw;
 809 +       unsigned int res;
 810 +
 811 +       if (route_info->flags & IP6T_ROUTE_CONTINUE)
 812 +               goto do_it;
 813 +
 814 +       /* If we are at PREROUTING or INPUT hook
 815 +        * the TTL isn't decreased by the IP stack
 816 +        */
 817 +       if (hooknum == NF_IP6_PRE_ROUTING ||
 818 +           hooknum == NF_IP6_LOCAL_IN) {
 819 +
 820 +               struct ipv6hdr *ipv6h = skb->nh.ipv6h;
 821 +
 822 +               if (ipv6h->hop_limit <= 1) {
 823 +                       /* Force OUTPUT device used as source address */
 824 +                       skb->dev = skb->dst->dev;
 825 +
 826 +                       icmpv6_send(skb, ICMPV6_TIME_EXCEED,
 827 +                                   ICMPV6_EXC_HOPLIMIT, 0, skb->dev);
 828 +
 829 +                       return NF_DROP;
 830 +               }
 831 +
 832 +               ipv6h->hop_limit--;
 833 +       }
 834 +
 835 +       if ((route_info->flags & IP6T_ROUTE_TEE)) {
 836 +               /*
 837 +                * Copy the *pskb, and route the copy. Will later return
 838 +                * IP6T_CONTINUE for the original skb, which should continue
 839 +                * on its way as if nothing happened. The copy should be
 840 +                * independantly delivered to the ROUTE --gw.
 841 +                */
 842 +               skb = skb_copy(*pskb, GFP_ATOMIC);
 843 +               if (!skb) {
 844 +                       if (net_ratelimit())
 845 +                               DEBUGP(KERN_DEBUG "ip6t_ROUTE: copy failed!\n");
 846 +                       return IP6T_CONTINUE;
 847 +               }
 848 +       }
 849 +
 850 +do_it:
 851 +       if (route_info->oif[0]) {
 852 +               res = route6_oif(route_info, skb);
 853 +       } else if (!ipv6_addr_any(gw)) {
 854 +               res = route6_gw(route_info, skb);
 855 +       } else {
 856 +               if (net_ratelimit())
 857 +                       DEBUGP(KERN_DEBUG "ip6t_ROUTE: no parameter !\n");
 858 +               res = IP6T_CONTINUE;
 859 +       }
 860 +
 861 +       if ((route_info->flags & IP6T_ROUTE_TEE))
 862 +               res = IP6T_CONTINUE;
 863 +
 864 +       return res;
 865 +}
 866 +
 867 +
 868 +static int
 869 +ip6t_route_checkentry(const char *tablename,
 870 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
 871 +                     const void *entry,
 872 +#else
 873 +                     const struct ip6t_entry *entry
 874 +#endif
 875 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,17)
 876 +                     const struct xt_target *target,
 877 +#endif
 878 +                     void *targinfo,
 879 +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19)
 880 +                     unsigned int targinfosize,
 881 +#endif
 882 +                     unsigned int hook_mask)
 883 +{
 884 +       if (strcmp(tablename, "mangle") != 0) {
 885 +               printk("ip6t_ROUTE: can only be called from \"mangle\" table.\n");
 886 +               return 0;
 887 +       }
 888 +
 889 +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19)
 890 +       if (targinfosize != IP6T_ALIGN(sizeof(struct ip6t_route_target_info))) {
 891 +               printk(KERN_WARNING "ip6t_ROUTE: targinfosize %u != %Zu\n",
 892 +                      targinfosize,
 893 +                      IP6T_ALIGN(sizeof(struct ip6t_route_target_info)));
 894 +               return 0;
 895 +       }
 896 +#endif
 897 +
 898 +       return 1;
 899 +}
 900 +
 901 +
 902 +static struct ip6t_target ip6t_route_reg = {
 903 +       .name       = "ROUTE",
 904 +       .target     = ip6t_route_target,
 905 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,17)
 906 +       .targetsize = sizeof(struct ip6t_route_target_info),
 907 +#endif
 908 +       .checkentry = ip6t_route_checkentry,
 909 +       .me         = THIS_MODULE
 910 +};
 911 +
 912 +
 913 +static int __init init(void)
 914 +{
 915 +       printk(KERN_DEBUG "registering ipv6 ROUTE target\n");
 916 +       if (xt_register_target(&ip6t_route_reg))
 917 +               return -EINVAL;
 918 +
 919 +       return 0;
 920 +}
 921 +
 922 +
 923 +static void __exit fini(void)
 924 +{
 925 +       xt_unregister_target(&ip6t_route_reg);
 926 +}
 927 +
 928 +module_init(init);
 929 +module_exit(fini);
 930 +MODULE_LICENSE("GPL");
 931 Index: linux-2.6.21.7/net/ipv6/netfilter/Kconfig
 932 ===================================================================
 933 --- linux-2.6.21.7.orig/net/ipv6/netfilter/Kconfig
 934 +++ linux-2.6.21.7/net/ipv6/netfilter/Kconfig
 935 @@ -209,5 +209,18 @@ config IP6_NF_RAW
 936           If you want to compile it as a module, say M here and read
 937           <file:Documentation/modules.txt>.  If unsure, say `N'.
 938
 939 +config IP6_NF_TARGET_ROUTE
 940 +       tristate 'ROUTE target support'
 941 +       depends on IP6_NF_MANGLE
 942 +       help
 943 +         This option adds a `ROUTE' target, which enables you to setup unusual
 944 +         routes. The ROUTE target is also able to change the incoming interface
 945 +         of a packet.
 946 +
 947 +         The target can be or not a final target. It has to be used inside the
 948 +         mangle table.
 949 +
 950 +         Not working as a module.
 951 +
 952  endmenu
 953
 954 Index: linux-2.6.21.7/net/ipv6/netfilter/Makefile
 955 ===================================================================
 956 --- linux-2.6.21.7.orig/net/ipv6/netfilter/Makefile
 957 +++ linux-2.6.21.7/net/ipv6/netfilter/Makefile
 958 @@ -20,6 +20,7 @@ obj-$(CONFIG_IP6_NF_TARGET_LOG) += ip6t_
 959  obj-$(CONFIG_IP6_NF_RAW) += ip6table_raw.o
 960  obj-$(CONFIG_IP6_NF_MATCH_HL) += ip6t_hl.o
 961  obj-$(CONFIG_IP6_NF_TARGET_REJECT) += ip6t_REJECT.o
 962 +obj-$(CONFIG_IP6_NF_TARGET_ROUTE) += ip6t_ROUTE.o
 963  obj-$(CONFIG_IP6_NF_MATCH_MH) += ip6t_mh.o
 964
 965  # objects for l3 independent conntrack