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 @@ -74,6 +74,7 @@
  85  obj-$(CONFIG_IP_NF_TARGET_MASQUERADE) += ipt_MASQUERADE.o
  86  obj-$(CONFIG_IP_NF_TARGET_NETMAP) += ipt_NETMAP.o
  87  obj-$(CONFIG_IP_NF_TARGET_REDIRECT) += ipt_REDIRECT.o
  88 +obj-$(CONFIG_IP_NF_TARGET_ROUTE) += ipt_ROUTE.o
  89  obj-$(CONFIG_IP_NF_TARGET_REJECT) += ipt_REJECT.o
  90  obj-$(CONFIG_IP_NF_TARGET_SAME) += ipt_SAME.o
  91  obj-$(CONFIG_IP_NF_TARGET_TOS) += ipt_TOS.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 +1,450 @@
  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(&init_net, &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->header_ops)) {
 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(&init_net, 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(&init_net, 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 *skb, const struct xt_target_param *par)
 369 +{
 370 +       const struct ipt_route_target_info *route_info = par->targinfo;
 371 +       //struct sk_buff *skb = *pskb;
 372 +       unsigned int res;
 373 +
 374 +       if (skb->nfct == &route_tee_track.ct_general) {
 375 +               /* Loopback - a packet we already routed, is to be
 376 +                * routed another time. Avoid that, now.
 377 +                */
 378 +               if (net_ratelimit())
 379 +                       DEBUGP(KERN_DEBUG "ipt_ROUTE: loopback - DROP!\n");
 380 +               return NF_DROP;
 381 +       }
 382 +
 383 +       /* If we are at PREROUTING or INPUT hook
 384 +        * the TTL isn't decreased by the IP stack
 385 +        */
 386 +       if (par->hooknum == NF_INET_PRE_ROUTING ||
 387 +           par->hooknum == NF_INET_LOCAL_IN) {
 388 +
 389 +               struct iphdr *iph = ip_hdr(skb);
 390 +
 391 +               if (iph->ttl <= 1) {
 392 +                       struct rtable *rt;
 393 +                       struct flowi fl = {
 394 +                               .oif = 0,
 395 +                               .nl_u = {
 396 +                                       .ip4_u = {
 397 +                                               .daddr = iph->daddr,
 398 +                                               .saddr = iph->saddr,
 399 +                                               .tos = RT_TOS(iph->tos),
 400 +                                               .scope = ((iph->tos & RTO_ONLINK) ?
 401 +                                                         RT_SCOPE_LINK :
 402 +                                                         RT_SCOPE_UNIVERSE)
 403 +                                       }
 404 +                               }
 405 +                       };
 406 +
 407 +                       if (ip_route_output_key(&init_net, &rt, &fl)) {
 408 +                               return NF_DROP;
 409 +                       }
 410 +
 411 +                       if (skb->dev == rt->u.dst.dev) {
 412 +                               /* Drop old route. */
 413 +                               dst_release(skb->dst);
 414 +                               skb->dst = &rt->u.dst;
 415 +
 416 +                               /* this will traverse normal stack, and
 417 +                                * thus call conntrack on the icmp packet */
 418 +                               icmp_send(skb, ICMP_TIME_EXCEEDED,
 419 +                                         ICMP_EXC_TTL, 0);
 420 +                       }
 421 +
 422 +                       return NF_DROP;
 423 +               }
 424 +
 425 +               /*
 426 +                * If we are at INPUT the checksum must be recalculated since
 427 +                * the length could change as the result of a defragmentation.
 428 +                */
 429 +               if(par->hooknum == NF_INET_LOCAL_IN) {
 430 +                       iph->ttl = iph->ttl - 1;
 431 +                       iph->check = 0;
 432 +                       iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
 433 +               } else {
 434 +                       ip_decrease_ttl(iph);
 435 +               }
 436 +       }
 437 +
 438 +       if ((route_info->flags & IPT_ROUTE_TEE)) {
 439 +               /*
 440 +                * Copy the *pskb, and route the copy. Will later return
 441 +                * IPT_CONTINUE for the original skb, which should continue
 442 +                * on its way as if nothing happened. The copy should be
 443 +                * independantly delivered to the ROUTE --gw.
 444 +                */
 445 +               skb = skb_copy(skb, GFP_ATOMIC);
 446 +               if (!skb) {
 447 +                       if (net_ratelimit())
 448 +                               DEBUGP(KERN_DEBUG "ipt_ROUTE: copy failed!\n");
 449 +                       nf_conntrack_put(skb->nfct);
 450 +                       skb->nfct = &route_tee_track.ct_general;
 451 +                       skb->nfctinfo = IP_CT_NEW;
 452 +                       nf_conntrack_get(skb->nfct);
 453 +                       return IPT_CONTINUE;
 454 +               }
 455 +       }
 456 +
 457 +       /* Tell conntrack to forget this packet since it may get confused
 458 +        * when a packet is leaving with dst address == our address.
 459 +        * Good idea ? Dunno. Need advice.
 460 +        *
 461 +        * NEW: mark the skb with our &route_tee_track, so we avoid looping
 462 +        * on any already routed packet.
 463 +        */
 464 +       if (!(route_info->flags & IPT_ROUTE_CONTINUE)) {
 465 +               nf_conntrack_put(skb->nfct);
 466 +               skb->nfct = &route_tee_track.ct_general;
 467 +               skb->nfctinfo = IP_CT_NEW;
 468 +               nf_conntrack_get(skb->nfct);
 469 +       }
 470 +
 471 +       if (route_info->oif[0] != '\0') {
 472 +               res = route_oif(route_info, skb);
 473 +       } else if (route_info->iif[0] != '\0') {
 474 +               res = route_iif(route_info, skb);
 475 +       } else if (route_info->gw) {
 476 +               res = route_gw(route_info, skb);
 477 +       } else {
 478 +               if (net_ratelimit())
 479 +                       DEBUGP(KERN_DEBUG "ipt_ROUTE: no parameter !\n");
 480 +               res = IPT_CONTINUE;
 481 +       }
 482 +
 483 +       if ((route_info->flags & IPT_ROUTE_TEE))
 484 +               res = IPT_CONTINUE;
 485 +
 486 +       return res;
 487 +}
 488 +
 489 +static bool ipt_route_checkentry(const struct xt_tgchk_param *par)
 490 +/*static bool ipt_route_checkentry(const char *tablename,
 491 +                               const void *e,
 492 +                               const struct xt_target *target,
 493 +                               void *targinfo,
 494 +
 495 +                               unsigned int hook_mask) */
 496 +{
 497 +/*     if (strcmp(par->tablename, "mangle") != 0) {
 498 +               printk("ipt_ROUTE: bad table `%s', use the `mangle' table.\n",
 499 +                      par->tablename);
 500 +               return 0;
 501 +       }
 502 +*/
 503 +       if (par->hook_mask & ~(  (1 << NF_INET_PRE_ROUTING)
 504 +                           | (1 << NF_INET_LOCAL_IN)
 505 +                           | (1 << NF_INET_FORWARD)
 506 +                           | (1 << NF_INET_LOCAL_OUT)
 507 +                           | (1 << NF_INET_POST_ROUTING))) {
 508 +               printk("ipt_ROUTE: bad hook\n");
 509 +               return 0;
 510 +       }
 511 +
 512 +       return 1;
 513 +}
 514 +
 515 +static struct xt_target ipt_route_reg __read_mostly = {
 516 +       .name = "ROUTE",
 517 +       .family         = AF_INET,
 518 +       .target = ipt_route_target,
 519 +       .targetsize = sizeof(struct ipt_route_target_info),
 520 +       .table          = "mangle",
 521 +       .checkentry = ipt_route_checkentry,
 522 +       .me = THIS_MODULE,
 523 +};
 524 +
 525 +static int __init init(void)
 526 +{
 527 +       /* Set up fake conntrack (stolen from raw.patch):
 528 +           - to never be deleted, not in any hashes */
 529 +       atomic_set(&route_tee_track.ct_general.use, 1);
 530 +       /*  - and look it like as a confirmed connection */
 531 +       set_bit(IPS_CONFIRMED_BIT, &route_tee_track.status);
 532 +       /* Initialize fake conntrack so that NAT will skip it */
 533 +       route_tee_track.status |= IPS_NAT_DONE_MASK;
 534 +
 535 +       return xt_register_target(&ipt_route_reg);
 536 +}
 537 +
 538 +
 539 +static void __exit fini(void)
 540 +{
 541 +       xt_unregister_target(&ipt_route_reg);
 542 +}
 543 +
 544 +module_init(init);
 545 +module_exit(fini);
 546 diff -NurpP --minimal linux-2.6.21.a/net/ipv6/netfilter/Kconfig linux-2.6.21.b/net/ipv6/netfilter/Kconfig
 547 --- linux-2.6.21.a/net/ipv6/netfilter/Kconfig   2007-05-30 11:13:04.000000000 +0200
 548 +++ linux-2.6.21.b/net/ipv6/netfilter/Kconfig   2007-05-30 11:40:37.000000000 +0200
 549 @@ -209,5 +209,18 @@ config IP6_NF_RAW
 550           If you want to compile it as a module, say M here and read
 551           <file:Documentation/modules.txt>.  If unsure, say `N'.
 552
 553 +config IP6_NF_TARGET_ROUTE
 554 +       tristate 'ROUTE target support'
 555 +       depends on IP6_NF_MANGLE
 556 +       help
 557 +         This option adds a `ROUTE' target, which enables you to setup unusual
 558 +         routes. The ROUTE target is also able to change the incoming interface
 559 +         of a packet.
 560 +
 561 +         The target can be or not a final target. It has to be used inside the
 562 +         mangle table.
 563 +
 564 +         Not working as a module.
 565 +
 566  endmenu
 567
 568 diff -NurpP --minimal linux-2.6.21.a/net/ipv6/netfilter/Makefile linux-2.6.21.b/net/ipv6/netfilter/Makefile
 569 --- linux-2.6.21.a/net/ipv6/netfilter/Makefile  2007-05-30 11:13:04.000000000 +0200
 570 +++ linux-2.6.21.b/net/ipv6/netfilter/Makefile  2007-05-30 11:40:37.000000000 +0200
 571 @@ -30,3 +30,4 @@
 572  obj-$(CONFIG_IP6_NF_TARGET_HL) += ip6t_HL.o
 573  obj-$(CONFIG_IP6_NF_TARGET_LOG) += ip6t_LOG.o
 574  obj-$(CONFIG_IP6_NF_TARGET_REJECT) += ip6t_REJECT.o
 575 +obj-$(CONFIG_IP6_NF_TARGET_ROUTE) += ip6t_ROUTE.o
 576 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
 577 --- linux-2.6.21.a/net/ipv6/netfilter/ip6t_ROUTE.c      1970-01-01 01:00:00.000000000 +0100
 578 +++ linux-2.6.21.b/net/ipv6/netfilter/ip6t_ROUTE.c      2007-05-30 11:40:37.000000000 +0200
 579 @@ -0,0 +1,293 @@
 580 +/*
 581 + * This implements the ROUTE v6 target, which enables you to setup unusual
 582 + * routes not supported by the standard kernel routing table.
 583 + *
 584 + * Copyright (C) 2003 Cedric de Launois <delaunois@info.ucl.ac.be>
 585 + *
 586 + * v 1.1 2004/11/23
 587 + *
 588 + * This software is distributed under GNU GPL v2, 1991
 589 + */
 590 +
 591 +#include <linux/module.h>
 592 +#include <linux/skbuff.h>
 593 +#include <linux/ipv6.h>
 594 +#include <linux/netfilter/x_tables.h>
 595 +#include <linux/netfilter_ipv6/ip6_tables.h>
 596 +#include <linux/netfilter_ipv6/ip6t_ROUTE.h>
 597 +#include <linux/netdevice.h>
 598 +#include <net/ipv6.h>
 599 +#include <net/ndisc.h>
 600 +#include <net/ip6_route.h>
 601 +#include <linux/icmpv6.h>
 602 +
 603 +#if 1
 604 +#define DEBUGP printk
 605 +#else
 606 +#define DEBUGP(format, args...)
 607 +#endif
 608 +
 609 +#define NIP6(addr) \
 610 +       ntohs((addr).s6_addr16[0]), \
 611 +       ntohs((addr).s6_addr16[1]), \
 612 +       ntohs((addr).s6_addr16[2]), \
 613 +       ntohs((addr).s6_addr16[3]), \
 614 +       ntohs((addr).s6_addr16[4]), \
 615 +       ntohs((addr).s6_addr16[5]), \
 616 +       ntohs((addr).s6_addr16[6]), \
 617 +       ntohs((addr).s6_addr16[7])
 618 +
 619 +/* Route the packet according to the routing keys specified in
 620 + * route_info. Keys are :
 621 + *  - ifindex :
 622 + *      0 if no oif preferred,
 623 + *      otherwise set to the index of the desired oif
 624 + *  - route_info->gw :
 625 + *      0 if no gateway specified,
 626 + *      otherwise set to the next host to which the pkt must be routed
 627 + * If success, skb->dev is the output device to which the packet must
 628 + * be sent and skb->dst is not NULL
 629 + *
 630 + * RETURN:  1 if the packet was succesfully routed to the
 631 + *            destination desired
 632 + *          0 if the kernel routing table could not route the packet
 633 + *            according to the keys specified
 634 + */
 635 +static int
 636 +route6(struct sk_buff *skb,
 637 +       unsigned int ifindex,
 638 +       const struct ip6t_route_target_info *route_info)
 639 +{
 640 +       struct rt6_info *rt = NULL;
 641 +       struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 642 +       struct in6_addr *gw = (struct in6_addr*)&route_info->gw;
 643 +
 644 +       DEBUGP("ip6t_ROUTE: called with: ");
 645 +       DEBUGP("DST=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(ipv6h->daddr));
 646 +       DEBUGP("GATEWAY=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(*gw));
 647 +       DEBUGP("OUT=%s\n", route_info->oif);
 648 +
 649 +       if (ipv6_addr_any(gw))
 650 +               rt = rt6_lookup(dev_net(skb->dev), &ipv6h->daddr, &ipv6h->saddr, ifindex, 1);
 651 +       else
 652 +               rt = rt6_lookup(dev_net(skb->dev), gw, &ipv6h->saddr, ifindex, 1);
 653 +
 654 +       if (!rt)
 655 +               goto no_route;
 656 +
 657 +       DEBUGP("ip6t_ROUTE: routing gives: ");
 658 +       DEBUGP("DST=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(rt->rt6i_dst.addr));
 659 +       DEBUGP("GATEWAY=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(rt->rt6i_gateway));
 660 +       DEBUGP("OUT=%s\n", rt->rt6i_dev->name);
 661 +
 662 +       if (ifindex && rt->rt6i_dev->ifindex!=ifindex)
 663 +               goto wrong_route;
 664 +
 665 +       if (!rt->rt6i_nexthop) {
 666 +               DEBUGP("ip6t_ROUTE: discovering neighbour\n");
 667 +               rt->rt6i_nexthop = ndisc_get_neigh(rt->rt6i_dev, &rt->rt6i_dst.addr);
 668 +       }
 669 +
 670 +       /* Drop old route. */
 671 +       dst_release(skb->dst);
 672 +       skb->dst = &rt->u.dst;
 673 +       skb->dev = rt->rt6i_dev;
 674 +       return 1;
 675 +
 676 + wrong_route:
 677 +       dst_release(&rt->u.dst);
 678 + no_route:
 679 +       if (!net_ratelimit())
 680 +               return 0;
 681 +
 682 +       printk("ip6t_ROUTE: no explicit route found ");
 683 +       if (ifindex)
 684 +               printk("via interface %s ", route_info->oif);
 685 +       if (!ipv6_addr_any(gw))
 686 +               printk("via gateway %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x", NIP6(*gw));
 687 +       printk("\n");
 688 +       return 0;
 689 +}
 690 +
 691 +
 692 +/* Stolen from ip6_output_finish
 693 + * PRE : skb->dev is set to the device we are leaving by
 694 + *       skb->dst is not NULL
 695 + * POST: the packet is sent with the link layer header pushed
 696 + *       the packet is destroyed
 697 + */
 698 +static void ip_direct_send(struct sk_buff *skb)
 699 +{
 700 +       struct dst_entry *dst = skb->dst;
 701 +       struct hh_cache *hh = dst->hh;
 702 +
 703 +       if (hh) {
 704 +               neigh_hh_output(dst->hh, skb);
 705 +       } else if (dst->neighbour)
 706 +               dst->neighbour->output(skb);
 707 +       else {
 708 +               if (net_ratelimit())
 709 +                       DEBUGP(KERN_DEBUG "ip6t_ROUTE: no hdr & no neighbour cache!\n");
 710 +               kfree_skb(skb);
 711 +       }
 712 +}
 713 +
 714 +
 715 +static unsigned int
 716 +route6_oif(const struct ip6t_route_target_info *route_info,
 717 +          struct sk_buff *skb)
 718 +{
 719 +       unsigned int ifindex = 0;
 720 +       struct net_device *dev_out = NULL;
 721 +
 722 +       /* The user set the interface name to use.
 723 +        * Getting the current interface index.
 724 +        */
 725 +       if ((dev_out = dev_get_by_name(&init_net, route_info->oif))) {
 726 +               ifindex = dev_out->ifindex;
 727 +       } else {
 728 +               /* Unknown interface name : packet dropped */
 729 +               if (net_ratelimit())
 730 +                       DEBUGP("ip6t_ROUTE: oif interface %s not found\n", route_info->oif);
 731 +
 732 +               if (route_info->flags & IP6T_ROUTE_CONTINUE)
 733 +                       return IP6T_CONTINUE;
 734 +               else
 735 +                       return NF_DROP;
 736 +       }
 737 +
 738 +       /* Trying the standard way of routing packets */
 739 +       if (route6(skb, ifindex, route_info)) {
 740 +               dev_put(dev_out);
 741 +               if (route_info->flags & IP6T_ROUTE_CONTINUE)
 742 +                       return IP6T_CONTINUE;
 743 +
 744 +               ip_direct_send(skb);
 745 +               return NF_STOLEN;
 746 +       } else
 747 +               return NF_DROP;
 748 +}
 749 +
 750 +
 751 +static unsigned int
 752 +route6_gw(const struct ip6t_route_target_info *route_info,
 753 +         struct sk_buff *skb)
 754 +{
 755 +       if (route6(skb, 0, route_info)) {
 756 +               if (route_info->flags & IP6T_ROUTE_CONTINUE)
 757 +                       return IP6T_CONTINUE;
 758 +
 759 +               ip_direct_send(skb);
 760 +               return NF_STOLEN;
 761 +       } else
 762 +               return NF_DROP;
 763 +}
 764 +
 765 +
 766 +static unsigned int
 767 +ip6t_route_target(struct sk_buff *skb, const struct xt_target_param *par)
 768 +{
 769 +       const struct ip6t_route_target_info *route_info = par->targinfo;
 770 +       struct in6_addr *gw = (struct in6_addr*)&route_info->gw;
 771 +       unsigned int res;
 772 +
 773 +       if (route_info->flags & IP6T_ROUTE_CONTINUE)
 774 +               goto do_it;
 775 +
 776 +       /* If we are at PREROUTING or INPUT hook
 777 +        * the TTL isn't decreased by the IP stack
 778 +        */
 779 +       if (par->hooknum == NF_INET_PRE_ROUTING ||
 780 +           par->hooknum == NF_INET_LOCAL_IN) {
 781 +
 782 +               struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 783 +
 784 +               if (ipv6h->hop_limit <= 1) {
 785 +                       /* Force OUTPUT device used as source address */
 786 +                       skb->dev = skb->dst->dev;
 787 +
 788 +                       icmpv6_send(skb, ICMPV6_TIME_EXCEED,
 789 +                                   ICMPV6_EXC_HOPLIMIT, 0, skb->dev);
 790 +
 791 +                       return NF_DROP;
 792 +               }
 793 +
 794 +               ipv6h->hop_limit--;
 795 +       }
 796 +
 797 +       if ((route_info->flags & IP6T_ROUTE_TEE)) {
 798 +               /*
 799 +                * Copy the *pskb, and route the copy. Will later return
 800 +                * IP6T_CONTINUE for the original skb, which should continue
 801 +                * on its way as if nothing happened. The copy should be
 802 +                * independantly delivered to the ROUTE --gw.
 803 +                */
 804 +               skb = skb_copy(skb, GFP_ATOMIC);
 805 +               if (!skb) {
 806 +                       if (net_ratelimit())
 807 +                               DEBUGP(KERN_DEBUG "ip6t_ROUTE: copy failed!\n");
 808 +                       return IP6T_CONTINUE;
 809 +               }
 810 +       }
 811 +
 812 +do_it:
 813 +       if (route_info->oif[0]) {
 814 +               res = route6_oif(route_info, skb);
 815 +       } else if (!ipv6_addr_any(gw)) {
 816 +               res = route6_gw(route_info, skb);
 817 +       } else {
 818 +               if (net_ratelimit())
 819 +                       DEBUGP(KERN_DEBUG "ip6t_ROUTE: no parameter !\n");
 820 +               res = IP6T_CONTINUE;
 821 +       }
 822 +
 823 +       if ((route_info->flags & IP6T_ROUTE_TEE))
 824 +               res = IP6T_CONTINUE;
 825 +
 826 +       return res;
 827 +}
 828 +
 829 +
 830 +static bool
 831 +ip6t_route_checkentry(const struct xt_tgchk_param *par)
 832 +{
 833 +       /* if (targinfosize != IP6T_ALIGN(sizeof(struct ip6t_route_target_info))) {
 834 +               printk(KERN_WARNING "ip6t_ROUTE: targinfosize %u != %Zu\n",
 835 +                      targinfosize,
 836 +                      IP6T_ALIGN(sizeof(struct ip6t_route_target_info)));
 837 +               return 0;
 838 +       } */
 839 +
 840 +       return 1;
 841 +}
 842 +
 843 +
 844 +static struct xt_target ip6t_route_reg __read_mostly = {
 845 +       .name       = "ROUTE",
 846 +       .family     = NFPROTO_IPV6,
 847 +       .target     = ip6t_route_target,
 848 +       .targetsize = sizeof(struct ip6t_route_target_info),
 849 +       .table      = "mangle",
 850 +       .checkentry = ip6t_route_checkentry,
 851 +       .me         = THIS_MODULE
 852 +};
 853 +
 854 +
 855 +static int __init init(void)
 856 +{
 857 +       printk(KERN_DEBUG "registering ipv6 ROUTE target\n");
 858 +       if (xt_register_target(&ip6t_route_reg))
 859 +               return -EINVAL;
 860 +
 861 +       return 0;
 862 +}
 863 +
 864 +
 865 +static void __exit fini(void)
 866 +{
 867 +       xt_unregister_target(&ip6t_route_reg);
 868 +}
 869 +
 870 +module_init(init);
 871 +module_exit(fini);
 872 +MODULE_LICENSE("GPL");
 873 --- a/net/ipv6/ndisc.c  2007-07-09 01:32:17.000000000 +0200
 874 +++ b/net/ipv6/ndisc.c  2007-08-02 13:23:26.000000000 +0200
 875 @@ -154,6 +154,8 @@ struct neigh_table nd_tbl = {
 876         .gc_thresh3 =   1024,
 877  };
 878
 879 +EXPORT_SYMBOL(nd_tbl);
 880 +
 881  /* ND options */
 882  struct ndisc_options {
 883         struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];