target/linux/generic-2.6/patches-2.6.23/160-netfilter_route.patch

   1 Index: linux-2.6.23-rc6/include/linux/netfilter_ipv4/ipt_ROUTE.h
   2 ===================================================================
   3 --- /dev/null   1970-01-01 00:00:00.000000000 +0000
   4 +++ linux-2.6.23-rc6/include/linux/netfilter_ipv4/ipt_ROUTE.h   2007-09-21 16:24:03.000000000 +0800
   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-2.6.23-rc6/include/linux/netfilter_ipv6/ip6t_ROUTE.h
  30 ===================================================================
  31 --- /dev/null   1970-01-01 00:00:00.000000000 +0000
  32 +++ linux-2.6.23-rc6/include/linux/netfilter_ipv6/ip6t_ROUTE.h  2007-09-21 16:24:03.000000000 +0800
  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-2.6.23-rc6/net/ipv4/netfilter/ipt_ROUTE.c
  58 ===================================================================
  59 --- /dev/null   1970-01-01 00:00:00.000000000 +0000
  60 +++ linux-2.6.23-rc6/net/ipv4/netfilter/ipt_ROUTE.c     2007-09-21 16:24:03.000000000 +0800
  61 @@ -0,0 +1,463 @@
  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 <net/netfilter/nf_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 = ip_hdr(skb);
 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 nf_conn 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 = ip_hdr(skb);
 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 bool ipt_route_checkentry(const char *tablename,
 472 +                               const void *e,
 473 +                               const struct xt_target *target,
 474 +                               void *targinfo,
 475 +                               unsigned int hook_mask)
 476 +{
 477 +       if (strcmp(tablename, "mangle") != 0) {
 478 +               printk("ipt_ROUTE: bad table `%s', use the `mangle' table.\n",
 479 +                      tablename);
 480 +               return 0;
 481 +       }
 482 +
 483 +       if (hook_mask & ~(  (1 << NF_IP_PRE_ROUTING)
 484 +                           | (1 << NF_IP_LOCAL_IN)
 485 +                           | (1 << NF_IP_FORWARD)
 486 +                           | (1 << NF_IP_LOCAL_OUT)
 487 +                           | (1 << NF_IP_POST_ROUTING))) {
 488 +               printk("ipt_ROUTE: bad hook\n");
 489 +               return 0;
 490 +       }
 491 +
 492 +       return 1;
 493 +}
 494 +
 495 +
 496 +static struct ipt_target ipt_route_reg = {
 497 +       .name = "ROUTE",
 498 +       .target = ipt_route_target,
 499 +       .targetsize = sizeof(struct ipt_route_target_info),
 500 +       .checkentry = ipt_route_checkentry,
 501 +       .me = THIS_MODULE,
 502 +};
 503 +
 504 +static int __init init(void)
 505 +{
 506 +       /* Set up fake conntrack (stolen from raw.patch):
 507 +           - to never be deleted, not in any hashes */
 508 +       atomic_set(&route_tee_track.ct_general.use, 1);
 509 +       /*  - and look it like as a confirmed connection */
 510 +       set_bit(IPS_CONFIRMED_BIT, &route_tee_track.status);
 511 +       /* Initialize fake conntrack so that NAT will skip it */
 512 +       route_tee_track.status |= IPS_NAT_DONE_MASK;
 513 +
 514 +       return xt_register_target(&ipt_route_reg);
 515 +}
 516 +
 517 +
 518 +static void __exit fini(void)
 519 +{
 520 +       xt_unregister_target(&ipt_route_reg);
 521 +}
 522 +
 523 +module_init(init);
 524 +module_exit(fini);
 525 Index: linux-2.6.23-rc6/net/ipv4/netfilter/Kconfig
 526 ===================================================================
 527 --- linux-2.6.23-rc6.orig/net/ipv4/netfilter/Kconfig    2007-09-21 16:24:02.000000000 +0800
 528 +++ linux-2.6.23-rc6/net/ipv4/netfilter/Kconfig 2007-09-21 16:24:03.000000000 +0800
 529 @@ -562,5 +562,22 @@
 530           To compile it as a module, choose M here.  If unsure, say N.
 531
 532
 533 +config IP_NF_TARGET_ROUTE
 534 +       tristate  'ROUTE target support'
 535 +       depends on IP_NF_MANGLE
 536 +       help
 537 +         This option adds a `ROUTE' target, which enables you to setup unusual
 538 +         routes. For example, the ROUTE lets you route a received packet through
 539 +         an interface or towards a host, even if the regular destination of the
 540 +         packet is the router itself. The ROUTE target is also able to change the
 541 +         incoming interface of a packet.
 542 +
 543 +         The target can be or not a final target. It has to be used inside the
 544 +         mangle table.
 545 +
 546 +         If you want to compile it as a module, say M here and read
 547 +         Documentation/modules.txt.  The module will be called ipt_ROUTE.o.
 548 +         If unsure, say `N'.
 549 +
 550  endmenu
 551
 552 Index: linux-2.6.23-rc6/net/ipv4/netfilter/Makefile
 553 ===================================================================
 554 --- linux-2.6.23-rc6.orig/net/ipv4/netfilter/Makefile   2007-09-21 16:24:02.000000000 +0800
 555 +++ linux-2.6.23-rc6/net/ipv4/netfilter/Makefile        2007-09-21 16:24:03.000000000 +0800
 556 @@ -61,6 +61,7 @@
 557  obj-$(CONFIG_IP_NF_TARGET_IMQ) += ipt_IMQ.o
 558  obj-$(CONFIG_IP_NF_TARGET_MASQUERADE) += ipt_MASQUERADE.o
 559  obj-$(CONFIG_IP_NF_TARGET_REDIRECT) += ipt_REDIRECT.o
 560 +obj-$(CONFIG_IP_NF_TARGET_ROUTE) += ipt_ROUTE.o
 561  obj-$(CONFIG_IP_NF_TARGET_NETMAP) += ipt_NETMAP.o
 562  obj-$(CONFIG_IP_NF_TARGET_SAME) += ipt_SAME.o
 563  obj-$(CONFIG_IP_NF_TARGET_LOG) += ipt_LOG.o
 564 Index: linux-2.6.23-rc6/net/ipv6/ndisc.c
 565 ===================================================================
 566 --- linux-2.6.23-rc6.orig/net/ipv6/ndisc.c      2007-09-21 16:23:53.000000000 +0800
 567 +++ linux-2.6.23-rc6/net/ipv6/ndisc.c   2007-09-21 16:24:03.000000000 +0800
 568 @@ -154,6 +154,8 @@
 569         .gc_thresh3 =   1024,
 570  };
 571
 572 +EXPORT_SYMBOL(nd_tbl);
 573 +
 574  /* ND options */
 575  struct ndisc_options {
 576         struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];
 577 Index: linux-2.6.23-rc6/net/ipv6/netfilter/ip6t_ROUTE.c
 578 ===================================================================
 579 --- /dev/null   1970-01-01 00:00:00.000000000 +0000
 580 +++ linux-2.6.23-rc6/net/ipv6/netfilter/ip6t_ROUTE.c    2007-09-21 16:24:03.000000000 +0800
 581 @@ -0,0 +1,330 @@
 582 +/*
 583 + * This implements the ROUTE v6 target, which enables you to setup unusual
 584 + * routes not supported by the standard kernel routing table.
 585 + *
 586 + * Copyright (C) 2003 Cedric de Launois <delaunois@info.ucl.ac.be>
 587 + *
 588 + * v 1.1 2004/11/23
 589 + *
 590 + * This software is distributed under GNU GPL v2, 1991
 591 + */
 592 +
 593 +#include <linux/module.h>
 594 +#include <linux/skbuff.h>
 595 +#include <linux/ipv6.h>
 596 +#include <linux/netfilter_ipv6/ip6_tables.h>
 597 +#include <linux/netfilter_ipv6/ip6t_ROUTE.h>
 598 +#include <linux/netdevice.h>
 599 +#include <linux/version.h>
 600 +#include <net/ipv6.h>
 601 +#include <net/ndisc.h>
 602 +#include <net/ip6_route.h>
 603 +#include <linux/icmpv6.h>
 604 +
 605 +#if 1
 606 +#define DEBUGP printk
 607 +#else
 608 +#define DEBUGP(format, args...)
 609 +#endif
 610 +
 611 +#define NIP6(addr) \
 612 +       ntohs((addr).s6_addr16[0]), \
 613 +       ntohs((addr).s6_addr16[1]), \
 614 +       ntohs((addr).s6_addr16[2]), \
 615 +       ntohs((addr).s6_addr16[3]), \
 616 +       ntohs((addr).s6_addr16[4]), \
 617 +       ntohs((addr).s6_addr16[5]), \
 618 +       ntohs((addr).s6_addr16[6]), \
 619 +       ntohs((addr).s6_addr16[7])
 620 +
 621 +/* Route the packet according to the routing keys specified in
 622 + * route_info. Keys are :
 623 + *  - ifindex :
 624 + *      0 if no oif preferred,
 625 + *      otherwise set to the index of the desired oif
 626 + *  - route_info->gw :
 627 + *      0 if no gateway specified,
 628 + *      otherwise set to the next host to which the pkt must be routed
 629 + * If success, skb->dev is the output device to which the packet must
 630 + * be sent and skb->dst is not NULL
 631 + *
 632 + * RETURN:  1 if the packet was succesfully routed to the
 633 + *            destination desired
 634 + *          0 if the kernel routing table could not route the packet
 635 + *            according to the keys specified
 636 + */
 637 +static int
 638 +route6(struct sk_buff *skb,
 639 +       unsigned int ifindex,
 640 +       const struct ip6t_route_target_info *route_info)
 641 +{
 642 +       struct rt6_info *rt = NULL;
 643 +       struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 644 +       struct in6_addr *gw = (struct in6_addr*)&route_info->gw;
 645 +
 646 +       DEBUGP("ip6t_ROUTE: called with: ");
 647 +       DEBUGP("DST=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(ipv6h->daddr));
 648 +       DEBUGP("GATEWAY=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(*gw));
 649 +       DEBUGP("OUT=%s\n", route_info->oif);
 650 +
 651 +       if (ipv6_addr_any(gw))
 652 +               rt = rt6_lookup(&ipv6h->daddr, &ipv6h->saddr, ifindex, 1);
 653 +       else
 654 +               rt = rt6_lookup(gw, &ipv6h->saddr, ifindex, 1);
 655 +
 656 +       if (!rt)
 657 +               goto no_route;
 658 +
 659 +       DEBUGP("ip6t_ROUTE: routing gives: ");
 660 +       DEBUGP("DST=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(rt->rt6i_dst.addr));
 661 +       DEBUGP("GATEWAY=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(rt->rt6i_gateway));
 662 +       DEBUGP("OUT=%s\n", rt->rt6i_dev->name);
 663 +
 664 +       if (ifindex && rt->rt6i_dev->ifindex!=ifindex)
 665 +               goto wrong_route;
 666 +
 667 +       if (!rt->rt6i_nexthop) {
 668 +               DEBUGP("ip6t_ROUTE: discovering neighbour\n");
 669 +               rt->rt6i_nexthop = ndisc_get_neigh(rt->rt6i_dev, &rt->rt6i_dst.addr);
 670 +       }
 671 +
 672 +       /* Drop old route. */
 673 +       dst_release(skb->dst);
 674 +       skb->dst = &rt->u.dst;
 675 +       skb->dev = rt->rt6i_dev;
 676 +       return 1;
 677 +
 678 + wrong_route:
 679 +       dst_release(&rt->u.dst);
 680 + no_route:
 681 +       if (!net_ratelimit())
 682 +               return 0;
 683 +
 684 +       printk("ip6t_ROUTE: no explicit route found ");
 685 +       if (ifindex)
 686 +               printk("via interface %s ", route_info->oif);
 687 +       if (!ipv6_addr_any(gw))
 688 +               printk("via gateway %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x", NIP6(*gw));
 689 +       printk("\n");
 690 +       return 0;
 691 +}
 692 +
 693 +
 694 +/* Stolen from ip6_output_finish
 695 + * PRE : skb->dev is set to the device we are leaving by
 696 + *       skb->dst is not NULL
 697 + * POST: the packet is sent with the link layer header pushed
 698 + *       the packet is destroyed
 699 + */
 700 +static void ip_direct_send(struct sk_buff *skb)
 701 +{
 702 +       struct dst_entry *dst = skb->dst;
 703 +       struct hh_cache *hh = dst->hh;
 704 +
 705 +       if (hh) {
 706 +               read_lock_bh(&hh->hh_lock);
 707 +               memcpy(skb->data - 16, hh->hh_data, 16);
 708 +               read_unlock_bh(&hh->hh_lock);
 709 +               skb_push(skb, hh->hh_len);
 710 +               hh->hh_output(skb);
 711 +       } else if (dst->neighbour)
 712 +               dst->neighbour->output(skb);
 713 +       else {
 714 +               if (net_ratelimit())
 715 +                       DEBUGP(KERN_DEBUG "ip6t_ROUTE: no hdr & no neighbour cache!\n");
 716 +               kfree_skb(skb);
 717 +       }
 718 +}
 719 +
 720 +
 721 +static unsigned int
 722 +route6_oif(const struct ip6t_route_target_info *route_info,
 723 +          struct sk_buff *skb)
 724 +{
 725 +       unsigned int ifindex = 0;
 726 +       struct net_device *dev_out = NULL;
 727 +
 728 +       /* The user set the interface name to use.
 729 +        * Getting the current interface index.
 730 +        */
 731 +       if ((dev_out = dev_get_by_name(route_info->oif))) {
 732 +               ifindex = dev_out->ifindex;
 733 +       } else {
 734 +               /* Unknown interface name : packet dropped */
 735 +               if (net_ratelimit())
 736 +                       DEBUGP("ip6t_ROUTE: oif interface %s not found\n", route_info->oif);
 737 +
 738 +               if (route_info->flags & IP6T_ROUTE_CONTINUE)
 739 +                       return IP6T_CONTINUE;
 740 +               else
 741 +                       return NF_DROP;
 742 +       }
 743 +
 744 +       /* Trying the standard way of routing packets */
 745 +       if (route6(skb, ifindex, route_info)) {
 746 +               dev_put(dev_out);
 747 +               if (route_info->flags & IP6T_ROUTE_CONTINUE)
 748 +                       return IP6T_CONTINUE;
 749 +
 750 +               ip_direct_send(skb);
 751 +               return NF_STOLEN;
 752 +       } else
 753 +               return NF_DROP;
 754 +}
 755 +
 756 +
 757 +static unsigned int
 758 +route6_gw(const struct ip6t_route_target_info *route_info,
 759 +         struct sk_buff *skb)
 760 +{
 761 +       if (route6(skb, 0, route_info)) {
 762 +               if (route_info->flags & IP6T_ROUTE_CONTINUE)
 763 +                       return IP6T_CONTINUE;
 764 +
 765 +               ip_direct_send(skb);
 766 +               return NF_STOLEN;
 767 +       } else
 768 +               return NF_DROP;
 769 +}
 770 +
 771 +
 772 +static unsigned int
 773 +ip6t_route_target(struct sk_buff **pskb,
 774 +                 const struct net_device *in,
 775 +                 const struct net_device *out,
 776 +                 unsigned int hooknum,
 777 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,17)
 778 +                 const struct xt_target *target,
 779 +#endif
 780 +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19)
 781 +                 const void *targinfo,
 782 +                 void *userinfo)
 783 +#else
 784 +                 const void *targinfo)
 785 +#endif
 786 +{
 787 +       const struct ip6t_route_target_info *route_info = targinfo;
 788 +       struct sk_buff *skb = *pskb;
 789 +       struct in6_addr *gw = (struct in6_addr*)&route_info->gw;
 790 +       unsigned int res;
 791 +
 792 +       if (route_info->flags & IP6T_ROUTE_CONTINUE)
 793 +               goto do_it;
 794 +
 795 +       /* If we are at PREROUTING or INPUT hook
 796 +        * the TTL isn't decreased by the IP stack
 797 +        */
 798 +       if (hooknum == NF_IP6_PRE_ROUTING ||
 799 +           hooknum == NF_IP6_LOCAL_IN) {
 800 +
 801 +               struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 802 +
 803 +               if (ipv6h->hop_limit <= 1) {
 804 +                       /* Force OUTPUT device used as source address */
 805 +                       skb->dev = skb->dst->dev;
 806 +
 807 +                       icmpv6_send(skb, ICMPV6_TIME_EXCEED,
 808 +                                   ICMPV6_EXC_HOPLIMIT, 0, skb->dev);
 809 +
 810 +                       return NF_DROP;
 811 +               }
 812 +
 813 +               ipv6h->hop_limit--;
 814 +       }
 815 +
 816 +       if ((route_info->flags & IP6T_ROUTE_TEE)) {
 817 +               /*
 818 +                * Copy the *pskb, and route the copy. Will later return
 819 +                * IP6T_CONTINUE for the original skb, which should continue
 820 +                * on its way as if nothing happened. The copy should be
 821 +                * independantly delivered to the ROUTE --gw.
 822 +                */
 823 +               skb = skb_copy(*pskb, GFP_ATOMIC);
 824 +               if (!skb) {
 825 +                       if (net_ratelimit())
 826 +                               DEBUGP(KERN_DEBUG "ip6t_ROUTE: copy failed!\n");
 827 +                       return IP6T_CONTINUE;
 828 +               }
 829 +       }
 830 +
 831 +do_it:
 832 +       if (route_info->oif[0]) {
 833 +               res = route6_oif(route_info, skb);
 834 +       } else if (!ipv6_addr_any(gw)) {
 835 +               res = route6_gw(route_info, skb);
 836 +       } else {
 837 +               if (net_ratelimit())
 838 +                       DEBUGP(KERN_DEBUG "ip6t_ROUTE: no parameter !\n");
 839 +               res = IP6T_CONTINUE;
 840 +       }
 841 +
 842 +       if ((route_info->flags & IP6T_ROUTE_TEE))
 843 +               res = IP6T_CONTINUE;
 844 +
 845 +       return res;
 846 +}
 847 +
 848 +
 849 +static int
 850 +ip6t_route_checkentry(const char *tablename,
 851 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
 852 +                     const void *entry,
 853 +#else
 854 +                     const struct ip6t_entry *entry
 855 +#endif
 856 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,17)
 857 +                     const struct xt_target *target,
 858 +#endif
 859 +                     void *targinfo,
 860 +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19)
 861 +                     unsigned int targinfosize,
 862 +#endif
 863 +                     unsigned int hook_mask)
 864 +{
 865 +       if (strcmp(tablename, "mangle") != 0) {
 866 +               printk("ip6t_ROUTE: can only be called from \"mangle\" table.\n");
 867 +               return 0;
 868 +       }
 869 +
 870 +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19)
 871 +       if (targinfosize != IP6T_ALIGN(sizeof(struct ip6t_route_target_info))) {
 872 +               printk(KERN_WARNING "ip6t_ROUTE: targinfosize %u != %Zu\n",
 873 +                      targinfosize,
 874 +                      IP6T_ALIGN(sizeof(struct ip6t_route_target_info)));
 875 +               return 0;
 876 +       }
 877 +#endif
 878 +
 879 +       return 1;
 880 +}
 881 +
 882 +
 883 +static struct ip6t_target ip6t_route_reg = {
 884 +       .name       = "ROUTE",
 885 +       .target     = ip6t_route_target,
 886 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,17)
 887 +       .targetsize = sizeof(struct ip6t_route_target_info),
 888 +#endif
 889 +       .checkentry = ip6t_route_checkentry,
 890 +       .me         = THIS_MODULE
 891 +};
 892 +
 893 +
 894 +static int __init init(void)
 895 +{
 896 +       printk(KERN_DEBUG "registering ipv6 ROUTE target\n");
 897 +       if (xt_register_target(&ip6t_route_reg))
 898 +               return -EINVAL;
 899 +
 900 +       return 0;
 901 +}
 902 +
 903 +
 904 +static void __exit fini(void)
 905 +{
 906 +       xt_unregister_target(&ip6t_route_reg);
 907 +}
 908 +
 909 +module_init(init);
 910 +module_exit(fini);
 911 +MODULE_LICENSE("GPL");
 912 Index: linux-2.6.23-rc6/net/ipv6/netfilter/Kconfig
 913 ===================================================================
 914 --- linux-2.6.23-rc6.orig/net/ipv6/netfilter/Kconfig    2007-09-21 16:24:02.000000000 +0800
 915 +++ linux-2.6.23-rc6/net/ipv6/netfilter/Kconfig 2007-09-21 16:24:03.000000000 +0800
 916 @@ -209,5 +209,18 @@
 917           If you want to compile it as a module, say M here and read
 918           <file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.
 919
 920 +config IP6_NF_TARGET_ROUTE
 921 +       tristate 'ROUTE target support'
 922 +       depends on IP6_NF_MANGLE
 923 +       help
 924 +         This option adds a `ROUTE' target, which enables you to setup unusual
 925 +         routes. The ROUTE target is also able to change the incoming interface
 926 +         of a packet.
 927 +
 928 +         The target can be or not a final target. It has to be used inside the
 929 +         mangle table.
 930 +
 931 +         Not working as a module.
 932 +
 933  endmenu
 934
 935 Index: linux-2.6.23-rc6/net/ipv6/netfilter/Makefile
 936 ===================================================================
 937 --- linux-2.6.23-rc6.orig/net/ipv6/netfilter/Makefile   2007-09-21 16:24:02.000000000 +0800
 938 +++ linux-2.6.23-rc6/net/ipv6/netfilter/Makefile        2007-09-21 16:24:03.000000000 +0800
 939 @@ -20,6 +20,7 @@
 940  obj-$(CONFIG_IP6_NF_RAW) += ip6table_raw.o
 941  obj-$(CONFIG_IP6_NF_MATCH_HL) += ip6t_hl.o
 942  obj-$(CONFIG_IP6_NF_TARGET_REJECT) += ip6t_REJECT.o
 943 +obj-$(CONFIG_IP6_NF_TARGET_ROUTE) += ip6t_ROUTE.o
 944  obj-$(CONFIG_IP6_NF_MATCH_MH) += ip6t_mh.o
 945
 946  # objects for l3 independent conntrack