kernel-pom-ng-ROUTE.patch

   1 diff -NurpP --minimal linux-2.6.21.a/include/linux/netfilter_ipv4/ipt_ROUTE.h linux-2.6.21.b/include/linux/netfilter_ipv4/ipt_ROUTE.h
   2 --- linux-2.6.21.a/include/linux/netfilter_ipv4/ipt_ROUTE.h     1970-01-01 01:00:00.000000000 +0100
   3 +++ linux-2.6.21.b/include/linux/netfilter_ipv4/ipt_ROUTE.h     2007-05-30 11:40:37.000000000 +0200
   4 @@ -0,0 +1,23 @@
   5 +/* Header file for iptables ipt_ROUTE target
   6 + *
   7 + * (C) 2002 by Cédric de Launois <delaunois@info.ucl.ac.be>
   8 + *
   9 + * This software is distributed under GNU GPL v2, 1991
  10 + */
  11 +#ifndef _IPT_ROUTE_H_target
  12 +#define _IPT_ROUTE_H_target
  13 +
  14 +#define IPT_ROUTE_IFNAMSIZ 16
  15 +
  16 +struct ipt_route_target_info {
  17 +       char      oif[IPT_ROUTE_IFNAMSIZ];      /* Output Interface Name */
  18 +       char      iif[IPT_ROUTE_IFNAMSIZ];      /* Input Interface Name  */
  19 +       u_int32_t gw;                           /* IP address of gateway */
  20 +       u_int8_t  flags;
  21 +};
  22 +
  23 +/* Values for "flags" field */
  24 +#define IPT_ROUTE_CONTINUE        0x01
  25 +#define IPT_ROUTE_TEE             0x02
  26 +
  27 +#endif /*_IPT_ROUTE_H_target*/
  28 diff -NurpP --minimal linux-2.6.21.a/include/linux/netfilter_ipv6/ip6t_ROUTE.h linux-2.6.21.b/include/linux/netfilter_ipv6/ip6t_ROUTE.h
  29 --- linux-2.6.21.a/include/linux/netfilter_ipv6/ip6t_ROUTE.h    1970-01-01 01:00:00.000000000 +0100
  30 +++ linux-2.6.21.b/include/linux/netfilter_ipv6/ip6t_ROUTE.h    2007-05-30 11:40:37.000000000 +0200
  31 @@ -0,0 +1,23 @@
  32 +/* Header file for iptables ip6t_ROUTE target
  33 + *
  34 + * (C) 2003 by Cédric de Launois <delaunois@info.ucl.ac.be>
  35 + *
  36 + * This software is distributed under GNU GPL v2, 1991
  37 + */
  38 +#ifndef _IPT_ROUTE_H_target
  39 +#define _IPT_ROUTE_H_target
  40 +
  41 +#define IP6T_ROUTE_IFNAMSIZ 16
  42 +
  43 +struct ip6t_route_target_info {
  44 +       char      oif[IP6T_ROUTE_IFNAMSIZ];     /* Output Interface Name */
  45 +       char      iif[IP6T_ROUTE_IFNAMSIZ];     /* Input Interface Name  */
  46 +       u_int32_t gw[4];                        /* IPv6 address of gateway */
  47 +       u_int8_t  flags;
  48 +};
  49 +
  50 +/* Values for "flags" field */
  51 +#define IP6T_ROUTE_CONTINUE        0x01
  52 +#define IP6T_ROUTE_TEE             0x02
  53 +
  54 +#endif /*_IP6T_ROUTE_H_target*/
  55 diff -NurpP --minimal linux-2.6.21.a/net/ipv4/netfilter/Kconfig linux-2.6.21.b/net/ipv4/netfilter/Kconfig
  56 --- linux-2.6.21.a/net/ipv4/netfilter/Kconfig   2007-05-30 11:39:28.000000000 +0200
  57 +++ linux-2.6.21.b/net/ipv4/netfilter/Kconfig   2007-05-30 11:40:37.000000000 +0200
  58 @@ -813,5 +813,22 @@ config IP_NF_MATCH_U32
  59
  60           Details and examples are in the kernel module source.
  61
  62 +config IP_NF_TARGET_ROUTE
  63 +       tristate  'ROUTE target support'
  64 +       depends on IP_NF_MANGLE
  65 +       help
  66 +         This option adds a `ROUTE' target, which enables you to setup unusual
  67 +         routes. For example, the ROUTE lets you route a received packet through
  68 +         an interface or towards a host, even if the regular destination of the
  69 +         packet is the router itself. The ROUTE target is also able to change the
  70 +         incoming interface of a packet.
  71 +
  72 +         The target can be or not a final target. It has to be used inside the
  73 +         mangle table.
  74 +
  75 +         If you want to compile it as a module, say M here and read
  76 +         Documentation/modules.txt.  The module will be called ipt_ROUTE.o.
  77 +         If unsure, say `N'.
  78 +
  79  endmenu
  80
  81 diff -NurpP --minimal linux-2.6.21.a/net/ipv4/netfilter/Makefile linux-2.6.21.b/net/ipv4/netfilter/Makefile
  82 --- linux-2.6.21.a/net/ipv4/netfilter/Makefile  2007-05-30 11:39:28.000000000 +0200
  83 +++ linux-2.6.21.b/net/ipv4/netfilter/Makefile  2007-05-30 11:40:37.000000000 +0200
  84 @@ -104,6 +104,7 @@ obj-$(CONFIG_IP_NF_TARGET_ECN) += ipt_EC
  85  obj-$(CONFIG_IP_NF_TARGET_IMQ) += ipt_IMQ.o
  86  obj-$(CONFIG_IP_NF_TARGET_MASQUERADE) += ipt_MASQUERADE.o
  87  obj-$(CONFIG_IP_NF_TARGET_REDIRECT) += ipt_REDIRECT.o
  88 +obj-$(CONFIG_IP_NF_TARGET_ROUTE) += ipt_ROUTE.o
  89  obj-$(CONFIG_IP_NF_TARGET_NETMAP) += ipt_NETMAP.o
  90  obj-$(CONFIG_IP_NF_TARGET_SAME) += ipt_SAME.o
  91  obj-$(CONFIG_IP_NF_NAT_SNMP_BASIC) += ip_nat_snmp_basic.o
  92 diff -NurpP --minimal linux-2.6.21.a/net/ipv4/netfilter/ipt_ROUTE.c linux-2.6.21.b/net/ipv4/netfilter/ipt_ROUTE.c
  93 --- linux-2.6.21.a/net/ipv4/netfilter/ipt_ROUTE.c       1970-01-01 01:00:00.000000000 +0100
  94 +++ linux-2.6.21.b/net/ipv4/netfilter/ipt_ROUTE.c       2007-05-30 11:40:37.000000000 +0200
  95 @@ -0,0 +1,458 @@
  96 +/*
  97 + * This implements the ROUTE target, which enables you to setup unusual
  98 + * routes not supported by the standard kernel routing table.
  99 + *
 100 + * Copyright (C) 2002 Cedric de Launois <delaunois@info.ucl.ac.be>
 101 + *
 102 + * v 1.11 2004/11/23
 103 + *
 104 + * This software is distributed under GNU GPL v2, 1991
 105 + */
 106 +
 107 +#include <linux/module.h>
 108 +#include <linux/skbuff.h>
 109 +#include <linux/ip.h>
 110 +#include <linux/netfilter/x_tables.h>
 111 +#include <linux/netfilter_ipv4/ip_tables.h>
 112 +#include <net/netfilter/nf_conntrack.h>
 113 +#include <linux/netfilter_ipv4/ipt_ROUTE.h>
 114 +#include <linux/netdevice.h>
 115 +#include <linux/route.h>
 116 +#include <linux/if_arp.h>
 117 +#include <net/ip.h>
 118 +#include <net/route.h>
 119 +#include <net/icmp.h>
 120 +#include <net/checksum.h>
 121 +
 122 +#if 0
 123 +#define DEBUGP printk
 124 +#else
 125 +#define DEBUGP(format, args...)
 126 +#endif
 127 +
 128 +MODULE_LICENSE("GPL");
 129 +MODULE_AUTHOR("Cedric de Launois <delaunois@info.ucl.ac.be>");
 130 +MODULE_DESCRIPTION("iptables ROUTE target module");
 131 +
 132 +/* Try to route the packet according to the routing keys specified in
 133 + * route_info. Keys are :
 134 + *  - ifindex :
 135 + *      0 if no oif preferred,
 136 + *      otherwise set to the index of the desired oif
 137 + *  - route_info->gw :
 138 + *      0 if no gateway specified,
 139 + *      otherwise set to the next host to which the pkt must be routed
 140 + * If success, skb->dev is the output device to which the packet must
 141 + * be sent and skb->dst is not NULL
 142 + *
 143 + * RETURN: -1 if an error occured
 144 + *          1 if the packet was succesfully routed to the
 145 + *            destination desired
 146 + *          0 if the kernel routing table could not route the packet
 147 + *            according to the keys specified
 148 + */
 149 +static int route(struct sk_buff *skb,
 150 +                unsigned int ifindex,
 151 +                const struct ipt_route_target_info *route_info)
 152 +{
 153 +       int err;
 154 +       struct rtable *rt;
 155 +       struct iphdr *iph = ip_hdr(skb);
 156 +       struct flowi fl = {
 157 +               .oif = ifindex,
 158 +               .nl_u = {
 159 +                       .ip4_u = {
 160 +                               .daddr = iph->daddr,
 161 +                               .saddr = 0,
 162 +                               .tos = RT_TOS(iph->tos),
 163 +                               .scope = RT_SCOPE_UNIVERSE,
 164 +                       }
 165 +               }
 166 +       };
 167 +
 168 +       /* The destination address may be overloaded by the target */
 169 +       if (route_info->gw)
 170 +               fl.fl4_dst = route_info->gw;
 171 +
 172 +       /* Trying to route the packet using the standard routing table. */
 173 +       if ((err = ip_route_output_key(&rt, &fl))) {
 174 +               if (net_ratelimit())
 175 +                       DEBUGP("ipt_ROUTE: couldn't route pkt (err: %i)",err);
 176 +               return -1;
 177 +       }
 178 +
 179 +       /* Drop old route. */
 180 +       dst_release(skb->dst);
 181 +       skb->dst = NULL;
 182 +
 183 +       /* Success if no oif specified or if the oif correspond to the
 184 +        * one desired */
 185 +       if (!ifindex || rt->u.dst.dev->ifindex == ifindex) {
 186 +               skb->dst = &rt->u.dst;
 187 +               skb->dev = skb->dst->dev;
 188 +               skb->protocol = htons(ETH_P_IP);
 189 +               return 1;
 190 +       }
 191 +
 192 +       /* The interface selected by the routing table is not the one
 193 +        * specified by the user. This may happen because the dst address
 194 +        * is one of our own addresses.
 195 +        */
 196 +       if (net_ratelimit())
 197 +               DEBUGP("ipt_ROUTE: failed to route as desired gw=%u.%u.%u.%u oif=%i (got oif=%i)\n",
 198 +                      NIPQUAD(route_info->gw), ifindex, rt->u.dst.dev->ifindex);
 199 +
 200 +       return 0;
 201 +}
 202 +
 203 +
 204 +/* Stolen from ip_finish_output2
 205 + * PRE : skb->dev is set to the device we are leaving by
 206 + *       skb->dst is not NULL
 207 + * POST: the packet is sent with the link layer header pushed
 208 + *       the packet is destroyed
 209 + */
 210 +static void ip_direct_send(struct sk_buff *skb)
 211 +{
 212 +       struct dst_entry *dst = skb->dst;
 213 +       struct hh_cache *hh = dst->hh;
 214 +       struct net_device *dev = dst->dev;
 215 +       int hh_len = LL_RESERVED_SPACE(dev);
 216 +
 217 +       /* Be paranoid, rather than too clever. */
 218 +       if (unlikely(skb_headroom(skb) < hh_len && dev->hard_header)) {
 219 +               struct sk_buff *skb2;
 220 +
 221 +               skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev));
 222 +               if (skb2 == NULL) {
 223 +                       kfree_skb(skb);
 224 +                       return;
 225 +               }
 226 +               if (skb->sk)
 227 +                       skb_set_owner_w(skb2, skb->sk);
 228 +               kfree_skb(skb);
 229 +               skb = skb2;
 230 +       }
 231 +
 232 +       if (hh) {
 233 +               neigh_hh_output(dst->hh, skb);
 234 +       } else if (dst->neighbour)
 235 +               dst->neighbour->output(skb);
 236 +       else {
 237 +               if (net_ratelimit())
 238 +                       DEBUGP(KERN_DEBUG "ipt_ROUTE: no hdr & no neighbour cache!\n");
 239 +               kfree_skb(skb);
 240 +       }
 241 +}
 242 +
 243 +
 244 +/* PRE : skb->dev is set to the device we are leaving by
 245 + * POST: - the packet is directly sent to the skb->dev device, without
 246 + *         pushing the link layer header.
 247 + *       - the packet is destroyed
 248 + */
 249 +static inline int dev_direct_send(struct sk_buff *skb)
 250 +{
 251 +       return dev_queue_xmit(skb);
 252 +}
 253 +
 254 +
 255 +static unsigned int route_oif(const struct ipt_route_target_info *route_info,
 256 +                             struct sk_buff *skb)
 257 +{
 258 +       unsigned int ifindex = 0;
 259 +       struct net_device *dev_out = NULL;
 260 +
 261 +       /* The user set the interface name to use.
 262 +        * Getting the current interface index.
 263 +        */
 264 +       if ((dev_out = dev_get_by_name(route_info->oif))) {
 265 +               ifindex = dev_out->ifindex;
 266 +       } else {
 267 +               /* Unknown interface name : packet dropped */
 268 +               if (net_ratelimit())
 269 +                       DEBUGP("ipt_ROUTE: oif interface %s not found\n", route_info->oif);
 270 +               return NF_DROP;
 271 +       }
 272 +
 273 +       /* Trying the standard way of routing packets */
 274 +       switch (route(skb, ifindex, route_info)) {
 275 +       case 1:
 276 +               dev_put(dev_out);
 277 +               if (route_info->flags & IPT_ROUTE_CONTINUE)
 278 +                       return IPT_CONTINUE;
 279 +
 280 +               ip_direct_send(skb);
 281 +               return NF_STOLEN;
 282 +
 283 +       case 0:
 284 +               /* Failed to send to oif. Trying the hard way */
 285 +               if (route_info->flags & IPT_ROUTE_CONTINUE)
 286 +                       return NF_DROP;
 287 +
 288 +               if (net_ratelimit())
 289 +                       DEBUGP("ipt_ROUTE: forcing the use of %i\n",
 290 +                              ifindex);
 291 +
 292 +               /* We have to force the use of an interface.
 293 +                * This interface must be a tunnel interface since
 294 +                * otherwise we can't guess the hw address for
 295 +                * the packet. For a tunnel interface, no hw address
 296 +                * is needed.
 297 +                */
 298 +               if ((dev_out->type != ARPHRD_TUNNEL)
 299 +                   && (dev_out->type != ARPHRD_IPGRE)) {
 300 +                       if (net_ratelimit())
 301 +                               DEBUGP("ipt_ROUTE: can't guess the hw addr !\n");
 302 +                       dev_put(dev_out);
 303 +                       return NF_DROP;
 304 +               }
 305 +
 306 +               /* Send the packet. This will also free skb
 307 +                * Do not go through the POST_ROUTING hook because
 308 +                * skb->dst is not set and because it will probably
 309 +                * get confused by the destination IP address.
 310 +                */
 311 +               skb->dev = dev_out;
 312 +               dev_direct_send(skb);
 313 +               dev_put(dev_out);
 314 +               return NF_STOLEN;
 315 +
 316 +       default:
 317 +               /* Unexpected error */
 318 +               dev_put(dev_out);
 319 +               return NF_DROP;
 320 +       }
 321 +}
 322 +
 323 +
 324 +static unsigned int route_iif(const struct ipt_route_target_info *route_info,
 325 +                             struct sk_buff *skb)
 326 +{
 327 +       struct net_device *dev_in = NULL;
 328 +
 329 +       /* Getting the current interface index. */
 330 +       if (!(dev_in = dev_get_by_name(route_info->iif))) {
 331 +               if (net_ratelimit())
 332 +                       DEBUGP("ipt_ROUTE: iif interface %s not found\n", route_info->iif);
 333 +               return NF_DROP;
 334 +       }
 335 +
 336 +       skb->dev = dev_in;
 337 +       dst_release(skb->dst);
 338 +       skb->dst = NULL;
 339 +
 340 +       netif_rx(skb);
 341 +       dev_put(dev_in);
 342 +       return NF_STOLEN;
 343 +}
 344 +
 345 +
 346 +static unsigned int route_gw(const struct ipt_route_target_info *route_info,
 347 +                            struct sk_buff *skb)
 348 +{
 349 +       if (route(skb, 0, route_info)!=1)
 350 +               return NF_DROP;
 351 +
 352 +       if (route_info->flags & IPT_ROUTE_CONTINUE)
 353 +               return IPT_CONTINUE;
 354 +
 355 +       ip_direct_send(skb);
 356 +       return NF_STOLEN;
 357 +}
 358 +
 359 +
 360 +/* To detect and deter routed packet loopback when using the --tee option,
 361 + * we take a page out of the raw.patch book: on the copied skb, we set up
 362 + * a fake ->nfct entry, pointing to the local &route_tee_track. We skip
 363 + * routing packets when we see they already have that ->nfct.
 364 + */
 365 +
 366 +static struct nf_conn route_tee_track;
 367 +
 368 +static unsigned int ipt_route_target(struct sk_buff **pskb,
 369 +                                    const struct net_device *in,
 370 +                                    const struct net_device *out,
 371 +                                    unsigned int hooknum,
 372 +                                    const struct xt_target *target,
 373 +                                    const void *targinfo
 374 +                                    )
 375 +{
 376 +       const struct ipt_route_target_info *route_info = targinfo;
 377 +       struct sk_buff *skb = *pskb;
 378 +       unsigned int res;
 379 +
 380 +       if (skb->nfct == &route_tee_track.ct_general) {
 381 +               /* Loopback - a packet we already routed, is to be
 382 +                * routed another time. Avoid that, now.
 383 +                */
 384 +               if (net_ratelimit())
 385 +                       DEBUGP(KERN_DEBUG "ipt_ROUTE: loopback - DROP!\n");
 386 +               return NF_DROP;
 387 +       }
 388 +
 389 +       /* If we are at PREROUTING or INPUT hook
 390 +        * the TTL isn't decreased by the IP stack
 391 +        */
 392 +       if (hooknum == NF_IP_PRE_ROUTING ||
 393 +           hooknum == NF_IP_LOCAL_IN) {
 394 +
 395 +               struct iphdr *iph = ip_hdr(skb);
 396 +
 397 +               if (iph->ttl <= 1) {
 398 +                       struct rtable *rt;
 399 +                       struct flowi fl = {
 400 +                               .oif = 0,
 401 +                               .nl_u = {
 402 +                                       .ip4_u = {
 403 +                                               .daddr = iph->daddr,
 404 +                                               .saddr = iph->saddr,
 405 +                                               .tos = RT_TOS(iph->tos),
 406 +                                               .scope = ((iph->tos & RTO_ONLINK) ?
 407 +                                                         RT_SCOPE_LINK :
 408 +                                                         RT_SCOPE_UNIVERSE)
 409 +                                       }
 410 +                               }
 411 +                       };
 412 +
 413 +                       if (ip_route_output_key(&rt, &fl)) {
 414 +                               return NF_DROP;
 415 +                       }
 416 +
 417 +                       if (skb->dev == rt->u.dst.dev) {
 418 +                               /* Drop old route. */
 419 +                               dst_release(skb->dst);
 420 +                               skb->dst = &rt->u.dst;
 421 +
 422 +                               /* this will traverse normal stack, and
 423 +                                * thus call conntrack on the icmp packet */
 424 +                               icmp_send(skb, ICMP_TIME_EXCEEDED,
 425 +                                         ICMP_EXC_TTL, 0);
 426 +                       }
 427 +
 428 +                       return NF_DROP;
 429 +               }
 430 +
 431 +               /*
 432 +                * If we are at INPUT the checksum must be recalculated since
 433 +                * the length could change as the result of a defragmentation.
 434 +                */
 435 +               if(hooknum == NF_IP_LOCAL_IN) {
 436 +                       iph->ttl = iph->ttl - 1;
 437 +                       iph->check = 0;
 438 +                       iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
 439 +               } else {
 440 +                       ip_decrease_ttl(iph);
 441 +               }
 442 +       }
 443 +
 444 +       if ((route_info->flags & IPT_ROUTE_TEE)) {
 445 +               /*
 446 +                * Copy the *pskb, and route the copy. Will later return
 447 +                * IPT_CONTINUE for the original skb, which should continue
 448 +                * on its way as if nothing happened. The copy should be
 449 +                * independantly delivered to the ROUTE --gw.
 450 +                */
 451 +               skb = skb_copy(*pskb, GFP_ATOMIC);
 452 +               if (!skb) {
 453 +                       if (net_ratelimit())
 454 +                               DEBUGP(KERN_DEBUG "ipt_ROUTE: copy failed!\n");
 455 +                       return IPT_CONTINUE;
 456 +               }
 457 +       }
 458 +
 459 +       /* Tell conntrack to forget this packet since it may get confused
 460 +        * when a packet is leaving with dst address == our address.
 461 +        * Good idea ? Dunno. Need advice.
 462 +        *
 463 +        * NEW: mark the skb with our &route_tee_track, so we avoid looping
 464 +        * on any already routed packet.
 465 +        */
 466 +       if (!(route_info->flags & IPT_ROUTE_CONTINUE)) {
 467 +               nf_conntrack_put(skb->nfct);
 468 +               skb->nfct = &route_tee_track.ct_general;
 469 +               skb->nfctinfo = IP_CT_NEW;
 470 +               nf_conntrack_get(skb->nfct);
 471 +       }
 472 +
 473 +       if (route_info->oif[0] != '\0') {
 474 +               res = route_oif(route_info, skb);
 475 +       } else if (route_info->iif[0] != '\0') {
 476 +               res = route_iif(route_info, skb);
 477 +       } else if (route_info->gw) {
 478 +               res = route_gw(route_info, skb);
 479 +       } else {
 480 +               if (net_ratelimit())
 481 +                       DEBUGP(KERN_DEBUG "ipt_ROUTE: no parameter !\n");
 482 +               res = IPT_CONTINUE;
 483 +       }
 484 +
 485 +       if ((route_info->flags & IPT_ROUTE_TEE))
 486 +               res = IPT_CONTINUE;
 487 +
 488 +       return res;
 489 +}
 490 +
 491 +
 492 +static int ipt_route_checkentry(const char *tablename,
 493 +                               const void *e,
 494 +                               const struct xt_target *target,
 495 +                               void *targinfo,
 496 +
 497 +                               unsigned int hook_mask)
 498 +{
 499 +       if (strcmp(tablename, "mangle") != 0) {
 500 +               printk("ipt_ROUTE: bad table `%s', use the `mangle' table.\n",
 501 +                      tablename);
 502 +               return 0;
 503 +       }
 504 +
 505 +       if (hook_mask & ~(  (1 << NF_IP_PRE_ROUTING)
 506 +                           | (1 << NF_IP_LOCAL_IN)
 507 +                           | (1 << NF_IP_FORWARD)
 508 +                           | (1 << NF_IP_LOCAL_OUT)
 509 +                           | (1 << NF_IP_POST_ROUTING))) {
 510 +               printk("ipt_ROUTE: bad hook\n");
 511 +               return 0;
 512 +       }
 513 +
 514 +
 515 +
 516 +
 517 +
 518 +
 519 +
 520 +
 521 +       return 1;
 522 +}
 523 +
 524 +
 525 +static struct ipt_target ipt_route_reg = {
 526 +       .name = "ROUTE",
 527 +       .target = ipt_route_target,
 528 +       .targetsize = sizeof(struct ipt_route_target_info),
 529 +       .checkentry = ipt_route_checkentry,
 530 +       .me = THIS_MODULE,
 531 +};
 532 +
 533 +static int __init init(void)
 534 +{
 535 +       /* Set up fake conntrack (stolen from raw.patch):
 536 +           - to never be deleted, not in any hashes */
 537 +       atomic_set(&route_tee_track.ct_general.use, 1);
 538 +       /*  - and look it like as a confirmed connection */
 539 +       set_bit(IPS_CONFIRMED_BIT, &route_tee_track.status);
 540 +       /* Initialize fake conntrack so that NAT will skip it */
 541 +       route_tee_track.status |= IPS_NAT_DONE_MASK;
 542 +
 543 +       return xt_register_target(&ipt_route_reg);
 544 +}
 545 +
 546 +
 547 +static void __exit fini(void)
 548 +{
 549 +       xt_unregister_target(&ipt_route_reg);
 550 +}
 551 +
 552 +module_init(init);
 553 +module_exit(fini);
 554 diff -NurpP --minimal linux-2.6.21.a/net/ipv6/netfilter/Kconfig linux-2.6.21.b/net/ipv6/netfilter/Kconfig
 555 --- linux-2.6.21.a/net/ipv6/netfilter/Kconfig   2007-05-30 11:13:04.000000000 +0200
 556 +++ linux-2.6.21.b/net/ipv6/netfilter/Kconfig   2007-05-30 11:40:37.000000000 +0200
 557 @@ -209,5 +209,18 @@ config IP6_NF_RAW
 558           If you want to compile it as a module, say M here and read
 559           <file:Documentation/modules.txt>.  If unsure, say `N'.
 560
 561 +config IP6_NF_TARGET_ROUTE
 562 +       tristate 'ROUTE target support'
 563 +       depends on IP6_NF_MANGLE
 564 +       help
 565 +         This option adds a `ROUTE' target, which enables you to setup unusual
 566 +         routes. The ROUTE target is also able to change the incoming interface
 567 +         of a packet.
 568 +
 569 +         The target can be or not a final target. It has to be used inside the
 570 +         mangle table.
 571 +
 572 +         Not working as a module.
 573 +
 574  endmenu
 575
 576 diff -NurpP --minimal linux-2.6.21.a/net/ipv6/netfilter/Makefile linux-2.6.21.b/net/ipv6/netfilter/Makefile
 577 --- linux-2.6.21.a/net/ipv6/netfilter/Makefile  2007-05-30 11:13:04.000000000 +0200
 578 +++ linux-2.6.21.b/net/ipv6/netfilter/Makefile  2007-05-30 11:40:37.000000000 +0200
 579 @@ -21,6 +21,7 @@ obj-$(CONFIG_IP6_NF_RAW) += ip6table_raw
 580  obj-$(CONFIG_IP6_NF_MATCH_HL) += ip6t_hl.o
 581  obj-$(CONFIG_IP6_NF_TARGET_REJECT) += ip6t_REJECT.o
 582  obj-$(CONFIG_IP6_NF_MATCH_MH) += ip6t_mh.o
 583 +obj-$(CONFIG_IP6_NF_TARGET_ROUTE) += ip6t_ROUTE.o
 584
 585  # objects for l3 independent conntrack
 586  nf_conntrack_ipv6-objs  :=  nf_conntrack_l3proto_ipv6.o nf_conntrack_proto_icmpv6.o nf_conntrack_reasm.o
 587 diff -NurpP --minimal linux-2.6.21.a/net/ipv6/netfilter/ip6t_ROUTE.c linux-2.6.21.b/net/ipv6/netfilter/ip6t_ROUTE.c
 588 --- linux-2.6.21.a/net/ipv6/netfilter/ip6t_ROUTE.c      1970-01-01 01:00:00.000000000 +0100
 589 +++ linux-2.6.21.b/net/ipv6/netfilter/ip6t_ROUTE.c      2007-05-30 11:40:37.000000000 +0200
 590 @@ -0,0 +1,308 @@
 591 +/*
 592 + * This implements the ROUTE v6 target, which enables you to setup unusual
 593 + * routes not supported by the standard kernel routing table.
 594 + *
 595 + * Copyright (C) 2003 Cedric de Launois <delaunois@info.ucl.ac.be>
 596 + *
 597 + * v 1.1 2004/11/23
 598 + *
 599 + * This software is distributed under GNU GPL v2, 1991
 600 + */
 601 +
 602 +#include <linux/module.h>
 603 +#include <linux/skbuff.h>
 604 +#include <linux/ipv6.h>
 605 +#include <linux/netfilter/x_tables.h>
 606 +#include <linux/netfilter_ipv6/ip6_tables.h>
 607 +#include <linux/netfilter_ipv6/ip6t_ROUTE.h>
 608 +#include <linux/netdevice.h>
 609 +#include <net/ipv6.h>
 610 +#include <net/ndisc.h>
 611 +#include <net/ip6_route.h>
 612 +#include <linux/icmpv6.h>
 613 +
 614 +#if 1
 615 +#define DEBUGP printk
 616 +#else
 617 +#define DEBUGP(format, args...)
 618 +#endif
 619 +
 620 +#define NIP6(addr) \
 621 +       ntohs((addr).s6_addr16[0]), \
 622 +       ntohs((addr).s6_addr16[1]), \
 623 +       ntohs((addr).s6_addr16[2]), \
 624 +       ntohs((addr).s6_addr16[3]), \
 625 +       ntohs((addr).s6_addr16[4]), \
 626 +       ntohs((addr).s6_addr16[5]), \
 627 +       ntohs((addr).s6_addr16[6]), \
 628 +       ntohs((addr).s6_addr16[7])
 629 +
 630 +/* Route the packet according to the routing keys specified in
 631 + * route_info. Keys are :
 632 + *  - ifindex :
 633 + *      0 if no oif preferred,
 634 + *      otherwise set to the index of the desired oif
 635 + *  - route_info->gw :
 636 + *      0 if no gateway specified,
 637 + *      otherwise set to the next host to which the pkt must be routed
 638 + * If success, skb->dev is the output device to which the packet must
 639 + * be sent and skb->dst is not NULL
 640 + *
 641 + * RETURN:  1 if the packet was succesfully routed to the
 642 + *            destination desired
 643 + *          0 if the kernel routing table could not route the packet
 644 + *            according to the keys specified
 645 + */
 646 +static int
 647 +route6(struct sk_buff *skb,
 648 +       unsigned int ifindex,
 649 +       const struct ip6t_route_target_info *route_info)
 650 +{
 651 +       struct rt6_info *rt = NULL;
 652 +       struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 653 +       struct in6_addr *gw = (struct in6_addr*)&route_info->gw;
 654 +
 655 +       DEBUGP("ip6t_ROUTE: called with: ");
 656 +       DEBUGP("DST=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(ipv6h->daddr));
 657 +       DEBUGP("GATEWAY=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(*gw));
 658 +       DEBUGP("OUT=%s\n", route_info->oif);
 659 +
 660 +       if (ipv6_addr_any(gw))
 661 +               rt = rt6_lookup(&ipv6h->daddr, &ipv6h->saddr, ifindex, 1);
 662 +       else
 663 +               rt = rt6_lookup(gw, &ipv6h->saddr, ifindex, 1);
 664 +
 665 +       if (!rt)
 666 +               goto no_route;
 667 +
 668 +       DEBUGP("ip6t_ROUTE: routing gives: ");
 669 +       DEBUGP("DST=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(rt->rt6i_dst.addr));
 670 +       DEBUGP("GATEWAY=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(rt->rt6i_gateway));
 671 +       DEBUGP("OUT=%s\n", rt->rt6i_dev->name);
 672 +
 673 +       if (ifindex && rt->rt6i_dev->ifindex!=ifindex)
 674 +               goto wrong_route;
 675 +
 676 +       if (!rt->rt6i_nexthop) {
 677 +               DEBUGP("ip6t_ROUTE: discovering neighbour\n");
 678 +               rt->rt6i_nexthop = ndisc_get_neigh(rt->rt6i_dev, &rt->rt6i_dst.addr);
 679 +       }
 680 +
 681 +       /* Drop old route. */
 682 +       dst_release(skb->dst);
 683 +       skb->dst = &rt->u.dst;
 684 +       skb->dev = rt->rt6i_dev;
 685 +       return 1;
 686 +
 687 + wrong_route:
 688 +       dst_release(&rt->u.dst);
 689 + no_route:
 690 +       if (!net_ratelimit())
 691 +               return 0;
 692 +
 693 +       printk("ip6t_ROUTE: no explicit route found ");
 694 +       if (ifindex)
 695 +               printk("via interface %s ", route_info->oif);
 696 +       if (!ipv6_addr_any(gw))
 697 +               printk("via gateway %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x", NIP6(*gw));
 698 +       printk("\n");
 699 +       return 0;
 700 +}
 701 +
 702 +
 703 +/* Stolen from ip6_output_finish
 704 + * PRE : skb->dev is set to the device we are leaving by
 705 + *       skb->dst is not NULL
 706 + * POST: the packet is sent with the link layer header pushed
 707 + *       the packet is destroyed
 708 + */
 709 +static void ip_direct_send(struct sk_buff *skb)
 710 +{
 711 +       struct dst_entry *dst = skb->dst;
 712 +       struct hh_cache *hh = dst->hh;
 713 +
 714 +       if (hh) {
 715 +               neigh_hh_output(dst->hh, skb);
 716 +       } else if (dst->neighbour)
 717 +               dst->neighbour->output(skb);
 718 +       else {
 719 +               if (net_ratelimit())
 720 +                       DEBUGP(KERN_DEBUG "ip6t_ROUTE: no hdr & no neighbour cache!\n");
 721 +               kfree_skb(skb);
 722 +       }
 723 +}
 724 +
 725 +
 726 +static unsigned int
 727 +route6_oif(const struct ip6t_route_target_info *route_info,
 728 +          struct sk_buff *skb)
 729 +{
 730 +       unsigned int ifindex = 0;
 731 +       struct net_device *dev_out = NULL;
 732 +
 733 +       /* The user set the interface name to use.
 734 +        * Getting the current interface index.
 735 +        */
 736 +       if ((dev_out = dev_get_by_name(route_info->oif))) {
 737 +               ifindex = dev_out->ifindex;
 738 +       } else {
 739 +               /* Unknown interface name : packet dropped */
 740 +               if (net_ratelimit())
 741 +                       DEBUGP("ip6t_ROUTE: oif interface %s not found\n", route_info->oif);
 742 +
 743 +               if (route_info->flags & IP6T_ROUTE_CONTINUE)
 744 +                       return IP6T_CONTINUE;
 745 +               else
 746 +                       return NF_DROP;
 747 +       }
 748 +
 749 +       /* Trying the standard way of routing packets */
 750 +       if (route6(skb, ifindex, route_info)) {
 751 +               dev_put(dev_out);
 752 +               if (route_info->flags & IP6T_ROUTE_CONTINUE)
 753 +                       return IP6T_CONTINUE;
 754 +
 755 +               ip_direct_send(skb);
 756 +               return NF_STOLEN;
 757 +       } else
 758 +               return NF_DROP;
 759 +}
 760 +
 761 +
 762 +static unsigned int
 763 +route6_gw(const struct ip6t_route_target_info *route_info,
 764 +         struct sk_buff *skb)
 765 +{
 766 +       if (route6(skb, 0, route_info)) {
 767 +               if (route_info->flags & IP6T_ROUTE_CONTINUE)
 768 +                       return IP6T_CONTINUE;
 769 +
 770 +               ip_direct_send(skb);
 771 +               return NF_STOLEN;
 772 +       } else
 773 +               return NF_DROP;
 774 +}
 775 +
 776 +
 777 +static unsigned int
 778 +ip6t_route_target(struct sk_buff **pskb,
 779 +                 const struct net_device *in,
 780 +                 const struct net_device *out,
 781 +                 unsigned int hooknum,
 782 +                 const struct xt_target *target,
 783 +                 const void *targinfo
 784 +                 )
 785 +{
 786 +       const struct ip6t_route_target_info *route_info = targinfo;
 787 +       struct sk_buff *skb = *pskb;
 788 +       struct in6_addr *gw = (struct in6_addr*)&route_info->gw;
 789 +       unsigned int res;
 790 +
 791 +       if (route_info->flags & IP6T_ROUTE_CONTINUE)
 792 +               goto do_it;
 793 +
 794 +       /* If we are at PREROUTING or INPUT hook
 795 +        * the TTL isn't decreased by the IP stack
 796 +        */
 797 +       if (hooknum == NF_IP6_PRE_ROUTING ||
 798 +           hooknum == NF_IP6_LOCAL_IN) {
 799 +
 800 +               struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 801 +
 802 +               if (ipv6h->hop_limit <= 1) {
 803 +                       /* Force OUTPUT device used as source address */
 804 +                       skb->dev = skb->dst->dev;
 805 +
 806 +                       icmpv6_send(skb, ICMPV6_TIME_EXCEED,
 807 +                                   ICMPV6_EXC_HOPLIMIT, 0, skb->dev);
 808 +
 809 +                       return NF_DROP;
 810 +               }
 811 +
 812 +               ipv6h->hop_limit--;
 813 +       }
 814 +
 815 +       if ((route_info->flags & IP6T_ROUTE_TEE)) {
 816 +               /*
 817 +                * Copy the *pskb, and route the copy. Will later return
 818 +                * IP6T_CONTINUE for the original skb, which should continue
 819 +                * on its way as if nothing happened. The copy should be
 820 +                * independantly delivered to the ROUTE --gw.
 821 +                */
 822 +               skb = skb_copy(*pskb, GFP_ATOMIC);
 823 +               if (!skb) {
 824 +                       if (net_ratelimit())
 825 +                               DEBUGP(KERN_DEBUG "ip6t_ROUTE: copy failed!\n");
 826 +                       return IP6T_CONTINUE;
 827 +               }
 828 +       }
 829 +
 830 +do_it:
 831 +       if (route_info->oif[0]) {
 832 +               res = route6_oif(route_info, skb);
 833 +       } else if (!ipv6_addr_any(gw)) {
 834 +               res = route6_gw(route_info, skb);
 835 +       } else {
 836 +               if (net_ratelimit())
 837 +                       DEBUGP(KERN_DEBUG "ip6t_ROUTE: no parameter !\n");
 838 +               res = IP6T_CONTINUE;
 839 +       }
 840 +
 841 +       if ((route_info->flags & IP6T_ROUTE_TEE))
 842 +               res = IP6T_CONTINUE;
 843 +
 844 +       return res;
 845 +}
 846 +
 847 +
 848 +static int
 849 +ip6t_route_checkentry(const char *tablename,
 850 +                     const void *entry,
 851 +                     const struct xt_target *target,
 852 +                     void *targinfo,
 853 +
 854 +                     unsigned int hook_mask)
 855 +{
 856 +       if (strcmp(tablename, "mangle") != 0) {
 857 +               printk("ip6t_ROUTE: can only be called from \"mangle\" table.\n");
 858 +               return 0;
 859 +       }
 860 +
 861 +       /* if (targinfosize != IP6T_ALIGN(sizeof(struct ip6t_route_target_info))) {
 862 +               printk(KERN_WARNING "ip6t_ROUTE: targinfosize %u != %Zu\n",
 863 +                      targinfosize,
 864 +                      IP6T_ALIGN(sizeof(struct ip6t_route_target_info)));
 865 +               return 0;
 866 +       } */
 867 +
 868 +       return 1;
 869 +}
 870 +
 871 +
 872 +static struct ip6t_target ip6t_route_reg = {
 873 +       .name       = "ROUTE",
 874 +       .target     = ip6t_route_target,
 875 +       .targetsize = sizeof(struct ip6t_route_target_info),
 876 +       .checkentry = ip6t_route_checkentry,
 877 +       .me         = THIS_MODULE
 878 +};
 879 +
 880 +
 881 +static int __init init(void)
 882 +{
 883 +       printk(KERN_DEBUG "registering ipv6 ROUTE target\n");
 884 +       if (xt_register_target(&ip6t_route_reg))
 885 +               return -EINVAL;
 886 +
 887 +       return 0;
 888 +}
 889 +
 890 +
 891 +static void __exit fini(void)
 892 +{
 893 +       xt_unregister_target(&ip6t_route_reg);
 894 +}
 895 +
 896 +module_init(init);
 897 +module_exit(fini);
 898 +MODULE_LICENSE("GPL");
 899 --- a/net/ipv6/ndisc.c  2007-07-09 01:32:17.000000000 +0200
 900 +++ b/net/ipv6/ndisc.c  2007-08-02 13:23:26.000000000 +0200
 901 @@ -154,6 +154,8 @@ struct neigh_table nd_tbl = {
 902         .gc_thresh3 =   1024,
 903  };
 904
 905 +EXPORT_SYMBOL(nd_tbl);
 906 +
 907  /* ND options */
 908  struct ndisc_options {
 909         struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];