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

   1 --- /dev/null
   2 +++ b/include/linux/netfilter_ipv4/ipt_ROUTE.h
   3 @@ -0,0 +1,23 @@
   4 +/* Header file for iptables ipt_ROUTE target
   5 + *
   6 + * (C) 2002 by Cédric de Launois <delaunois@info.ucl.ac.be>
   7 + *
   8 + * This software is distributed under GNU GPL v2, 1991
   9 + */
  10 +#ifndef _IPT_ROUTE_H_target
  11 +#define _IPT_ROUTE_H_target
  12 +
  13 +#define IPT_ROUTE_IFNAMSIZ 16
  14 +
  15 +struct ipt_route_target_info {
  16 +       char      oif[IPT_ROUTE_IFNAMSIZ];      /* Output Interface Name */
  17 +       char      iif[IPT_ROUTE_IFNAMSIZ];      /* Input Interface Name  */
  18 +       u_int32_t gw;                           /* IP address of gateway */
  19 +       u_int8_t  flags;
  20 +};
  21 +
  22 +/* Values for "flags" field */
  23 +#define IPT_ROUTE_CONTINUE        0x01
  24 +#define IPT_ROUTE_TEE             0x02
  25 +
  26 +#endif /*_IPT_ROUTE_H_target*/
  27 --- /dev/null
  28 +++ b/include/linux/netfilter_ipv6/ip6t_ROUTE.h
  29 @@ -0,0 +1,23 @@
  30 +/* Header file for iptables ip6t_ROUTE target
  31 + *
  32 + * (C) 2003 by Cédric de Launois <delaunois@info.ucl.ac.be>
  33 + *
  34 + * This software is distributed under GNU GPL v2, 1991
  35 + */
  36 +#ifndef _IPT_ROUTE_H_target
  37 +#define _IPT_ROUTE_H_target
  38 +
  39 +#define IP6T_ROUTE_IFNAMSIZ 16
  40 +
  41 +struct ip6t_route_target_info {
  42 +       char      oif[IP6T_ROUTE_IFNAMSIZ];     /* Output Interface Name */
  43 +       char      iif[IP6T_ROUTE_IFNAMSIZ];     /* Input Interface Name  */
  44 +       u_int32_t gw[4];                        /* IPv6 address of gateway */
  45 +       u_int8_t  flags;
  46 +};
  47 +
  48 +/* Values for "flags" field */
  49 +#define IP6T_ROUTE_CONTINUE        0x01
  50 +#define IP6T_ROUTE_TEE             0x02
  51 +
  52 +#endif /*_IP6T_ROUTE_H_target*/
  53 --- /dev/null
  54 +++ b/net/ipv4/netfilter/ipt_ROUTE.c
  55 @@ -0,0 +1,463 @@
  56 +/*
  57 + * This implements the ROUTE target, which enables you to setup unusual
  58 + * routes not supported by the standard kernel routing table.
  59 + *
  60 + * Copyright (C) 2002 Cedric de Launois <delaunois@info.ucl.ac.be>
  61 + *
  62 + * v 1.11 2004/11/23
  63 + *
  64 + * This software is distributed under GNU GPL v2, 1991
  65 + */
  66 +
  67 +#include <linux/module.h>
  68 +#include <linux/skbuff.h>
  69 +#include <linux/ip.h>
  70 +#include <linux/netfilter_ipv4/ip_tables.h>
  71 +#include <net/netfilter/nf_conntrack.h>
  72 +#include <linux/netfilter_ipv4/ipt_ROUTE.h>
  73 +#include <linux/netdevice.h>
  74 +#include <linux/route.h>
  75 +#include <linux/version.h>
  76 +#include <linux/if_arp.h>
  77 +#include <net/ip.h>
  78 +#include <net/route.h>
  79 +#include <net/icmp.h>
  80 +#include <net/checksum.h>
  81 +
  82 +#if 0
  83 +#define DEBUGP printk
  84 +#else
  85 +#define DEBUGP(format, args...)
  86 +#endif
  87 +
  88 +MODULE_LICENSE("GPL");
  89 +MODULE_AUTHOR("Cedric de Launois <delaunois@info.ucl.ac.be>");
  90 +MODULE_DESCRIPTION("iptables ROUTE target module");
  91 +
  92 +/* Try to route the packet according to the routing keys specified in
  93 + * route_info. Keys are :
  94 + *  - ifindex :
  95 + *      0 if no oif preferred,
  96 + *      otherwise set to the index of the desired oif
  97 + *  - route_info->gw :
  98 + *      0 if no gateway specified,
  99 + *      otherwise set to the next host to which the pkt must be routed
 100 + * If success, skb->dev is the output device to which the packet must
 101 + * be sent and skb->dst is not NULL
 102 + *
 103 + * RETURN: -1 if an error occured
 104 + *          1 if the packet was succesfully routed to the
 105 + *            destination desired
 106 + *          0 if the kernel routing table could not route the packet
 107 + *            according to the keys specified
 108 + */
 109 +static int route(struct sk_buff *skb,
 110 +                unsigned int ifindex,
 111 +                const struct ipt_route_target_info *route_info)
 112 +{
 113 +       int err;
 114 +       struct rtable *rt;
 115 +       struct iphdr *iph = ip_hdr(skb);
 116 +       struct flowi fl = {
 117 +               .oif = ifindex,
 118 +               .nl_u = {
 119 +                       .ip4_u = {
 120 +                               .daddr = iph->daddr,
 121 +                               .saddr = 0,
 122 +                               .tos = RT_TOS(iph->tos),
 123 +                               .scope = RT_SCOPE_UNIVERSE,
 124 +                       }
 125 +               }
 126 +       };
 127 +
 128 +       /* The destination address may be overloaded by the target */
 129 +       if (route_info->gw)
 130 +               fl.fl4_dst = route_info->gw;
 131 +
 132 +       /* Trying to route the packet using the standard routing table. */
 133 +       if ((err = ip_route_output_key(&rt, &fl))) {
 134 +               if (net_ratelimit())
 135 +                       DEBUGP("ipt_ROUTE: couldn't route pkt (err: %i)",err);
 136 +               return -1;
 137 +       }
 138 +
 139 +       /* Drop old route. */
 140 +       dst_release(skb->dst);
 141 +       skb->dst = NULL;
 142 +
 143 +       /* Success if no oif specified or if the oif correspond to the
 144 +        * one desired */
 145 +       if (!ifindex || rt->u.dst.dev->ifindex == ifindex) {
 146 +               skb->dst = &rt->u.dst;
 147 +               skb->dev = skb->dst->dev;
 148 +               skb->protocol = htons(ETH_P_IP);
 149 +               return 1;
 150 +       }
 151 +
 152 +       /* The interface selected by the routing table is not the one
 153 +        * specified by the user. This may happen because the dst address
 154 +        * is one of our own addresses.
 155 +        */
 156 +       if (net_ratelimit())
 157 +               DEBUGP("ipt_ROUTE: failed to route as desired gw=%u.%u.%u.%u oif=%i (got oif=%i)\n",
 158 +                      NIPQUAD(route_info->gw), ifindex, rt->u.dst.dev->ifindex);
 159 +
 160 +       return 0;
 161 +}
 162 +
 163 +
 164 +/* Stolen from ip_finish_output2
 165 + * PRE : skb->dev is set to the device we are leaving by
 166 + *       skb->dst is not NULL
 167 + * POST: the packet is sent with the link layer header pushed
 168 + *       the packet is destroyed
 169 + */
 170 +static void ip_direct_send(struct sk_buff *skb)
 171 +{
 172 +       struct dst_entry *dst = skb->dst;
 173 +       struct hh_cache *hh = dst->hh;
 174 +       struct net_device *dev = dst->dev;
 175 +       int hh_len = LL_RESERVED_SPACE(dev);
 176 +
 177 +       /* Be paranoid, rather than too clever. */
 178 +       if (unlikely(skb_headroom(skb) < hh_len && dev->hard_header)) {
 179 +               struct sk_buff *skb2;
 180 +
 181 +               skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev));
 182 +               if (skb2 == NULL) {
 183 +                       kfree_skb(skb);
 184 +                       return;
 185 +               }
 186 +               if (skb->sk)
 187 +                       skb_set_owner_w(skb2, skb->sk);
 188 +               kfree_skb(skb);
 189 +               skb = skb2;
 190 +       }
 191 +
 192 +       if (hh) {
 193 +               int hh_alen;
 194 +
 195 +               read_lock_bh(&hh->hh_lock);
 196 +               hh_alen = HH_DATA_ALIGN(hh->hh_len);
 197 +               memcpy(skb->data - hh_alen, hh->hh_data, hh_alen);
 198 +               read_unlock_bh(&hh->hh_lock);
 199 +               skb_push(skb, hh->hh_len);
 200 +               hh->hh_output(skb);
 201 +       } else if (dst->neighbour)
 202 +               dst->neighbour->output(skb);
 203 +       else {
 204 +               if (net_ratelimit())
 205 +                       DEBUGP(KERN_DEBUG "ipt_ROUTE: no hdr & no neighbour cache!\n");
 206 +               kfree_skb(skb);
 207 +       }
 208 +}
 209 +
 210 +
 211 +/* PRE : skb->dev is set to the device we are leaving by
 212 + * POST: - the packet is directly sent to the skb->dev device, without
 213 + *         pushing the link layer header.
 214 + *       - the packet is destroyed
 215 + */
 216 +static inline int dev_direct_send(struct sk_buff *skb)
 217 +{
 218 +       return dev_queue_xmit(skb);
 219 +}
 220 +
 221 +
 222 +static unsigned int route_oif(const struct ipt_route_target_info *route_info,
 223 +                             struct sk_buff *skb)
 224 +{
 225 +       unsigned int ifindex = 0;
 226 +       struct net_device *dev_out = NULL;
 227 +
 228 +       /* The user set the interface name to use.
 229 +        * Getting the current interface index.
 230 +        */
 231 +       if ((dev_out = dev_get_by_name(route_info->oif))) {
 232 +               ifindex = dev_out->ifindex;
 233 +       } else {
 234 +               /* Unknown interface name : packet dropped */
 235 +               if (net_ratelimit())
 236 +                       DEBUGP("ipt_ROUTE: oif interface %s not found\n", route_info->oif);
 237 +               return NF_DROP;
 238 +       }
 239 +
 240 +       /* Trying the standard way of routing packets */
 241 +       switch (route(skb, ifindex, route_info)) {
 242 +       case 1:
 243 +               dev_put(dev_out);
 244 +               if (route_info->flags & IPT_ROUTE_CONTINUE)
 245 +                       return IPT_CONTINUE;
 246 +
 247 +               ip_direct_send(skb);
 248 +               return NF_STOLEN;
 249 +
 250 +       case 0:
 251 +               /* Failed to send to oif. Trying the hard way */
 252 +               if (route_info->flags & IPT_ROUTE_CONTINUE)
 253 +                       return NF_DROP;
 254 +
 255 +               if (net_ratelimit())
 256 +                       DEBUGP("ipt_ROUTE: forcing the use of %i\n",
 257 +                              ifindex);
 258 +
 259 +               /* We have to force the use of an interface.
 260 +                * This interface must be a tunnel interface since
 261 +                * otherwise we can't guess the hw address for
 262 +                * the packet. For a tunnel interface, no hw address
 263 +                * is needed.
 264 +                */
 265 +               if ((dev_out->type != ARPHRD_TUNNEL)
 266 +                   && (dev_out->type != ARPHRD_IPGRE)) {
 267 +                       if (net_ratelimit())
 268 +                               DEBUGP("ipt_ROUTE: can't guess the hw addr !\n");
 269 +                       dev_put(dev_out);
 270 +                       return NF_DROP;
 271 +               }
 272 +
 273 +               /* Send the packet. This will also free skb
 274 +                * Do not go through the POST_ROUTING hook because
 275 +                * skb->dst is not set and because it will probably
 276 +                * get confused by the destination IP address.
 277 +                */
 278 +               skb->dev = dev_out;
 279 +               dev_direct_send(skb);
 280 +               dev_put(dev_out);
 281 +               return NF_STOLEN;
 282 +
 283 +       default:
 284 +               /* Unexpected error */
 285 +               dev_put(dev_out);
 286 +               return NF_DROP;
 287 +       }
 288 +}
 289 +
 290 +
 291 +static unsigned int route_iif(const struct ipt_route_target_info *route_info,
 292 +                             struct sk_buff *skb)
 293 +{
 294 +       struct net_device *dev_in = NULL;
 295 +
 296 +       /* Getting the current interface index. */
 297 +       if (!(dev_in = dev_get_by_name(route_info->iif))) {
 298 +               if (net_ratelimit())
 299 +                       DEBUGP("ipt_ROUTE: iif interface %s not found\n", route_info->iif);
 300 +               return NF_DROP;
 301 +       }
 302 +
 303 +       skb->dev = dev_in;
 304 +       dst_release(skb->dst);
 305 +       skb->dst = NULL;
 306 +
 307 +       netif_rx(skb);
 308 +       dev_put(dev_in);
 309 +       return NF_STOLEN;
 310 +}
 311 +
 312 +
 313 +static unsigned int route_gw(const struct ipt_route_target_info *route_info,
 314 +                            struct sk_buff *skb)
 315 +{
 316 +       if (route(skb, 0, route_info)!=1)
 317 +               return NF_DROP;
 318 +
 319 +       if (route_info->flags & IPT_ROUTE_CONTINUE)
 320 +               return IPT_CONTINUE;
 321 +
 322 +       ip_direct_send(skb);
 323 +       return NF_STOLEN;
 324 +}
 325 +
 326 +
 327 +/* To detect and deter routed packet loopback when using the --tee option,
 328 + * we take a page out of the raw.patch book: on the copied skb, we set up
 329 + * a fake ->nfct entry, pointing to the local &route_tee_track. We skip
 330 + * routing packets when we see they already have that ->nfct.
 331 + */
 332 +
 333 +static struct nf_conn route_tee_track;
 334 +
 335 +static unsigned int ipt_route_target(struct sk_buff **pskb,
 336 +                                    const struct net_device *in,
 337 +                                    const struct net_device *out,
 338 +                                    unsigned int hooknum,
 339 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,17)
 340 +                                    const struct xt_target *target,
 341 +#endif
 342 +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19)
 343 +                                    const void *targinfo,
 344 +                                    void *userinfo)
 345 +#else
 346 +                                    const void *targinfo)
 347 +#endif
 348 +{
 349 +       const struct ipt_route_target_info *route_info = targinfo;
 350 +       struct sk_buff *skb = *pskb;
 351 +       unsigned int res;
 352 +
 353 +       if (skb->nfct == &route_tee_track.ct_general) {
 354 +               /* Loopback - a packet we already routed, is to be
 355 +                * routed another time. Avoid that, now.
 356 +                */
 357 +               if (net_ratelimit())
 358 +                       DEBUGP(KERN_DEBUG "ipt_ROUTE: loopback - DROP!\n");
 359 +               return NF_DROP;
 360 +       }
 361 +
 362 +       /* If we are at PREROUTING or INPUT hook
 363 +        * the TTL isn't decreased by the IP stack
 364 +        */
 365 +       if (hooknum == NF_IP_PRE_ROUTING ||
 366 +           hooknum == NF_IP_LOCAL_IN) {
 367 +
 368 +               struct iphdr *iph = ip_hdr(skb);
 369 +
 370 +               if (iph->ttl <= 1) {
 371 +                       struct rtable *rt;
 372 +                       struct flowi fl = {
 373 +                               .oif = 0,
 374 +                               .nl_u = {
 375 +                                       .ip4_u = {
 376 +                                               .daddr = iph->daddr,
 377 +                                               .saddr = iph->saddr,
 378 +                                               .tos = RT_TOS(iph->tos),
 379 +                                               .scope = ((iph->tos & RTO_ONLINK) ?
 380 +                                                         RT_SCOPE_LINK :
 381 +                                                         RT_SCOPE_UNIVERSE)
 382 +                                       }
 383 +                               }
 384 +                       };
 385 +
 386 +                       if (ip_route_output_key(&rt, &fl)) {
 387 +                               return NF_DROP;
 388 +                       }
 389 +
 390 +                       if (skb->dev == rt->u.dst.dev) {
 391 +                               /* Drop old route. */
 392 +                               dst_release(skb->dst);
 393 +                               skb->dst = &rt->u.dst;
 394 +
 395 +                               /* this will traverse normal stack, and
 396 +                                * thus call conntrack on the icmp packet */
 397 +                               icmp_send(skb, ICMP_TIME_EXCEEDED,
 398 +                                         ICMP_EXC_TTL, 0);
 399 +                       }
 400 +
 401 +                       return NF_DROP;
 402 +               }
 403 +
 404 +               /*
 405 +                * If we are at INPUT the checksum must be recalculated since
 406 +                * the length could change as the result of a defragmentation.
 407 +                */
 408 +               if(hooknum == NF_IP_LOCAL_IN) {
 409 +                       iph->ttl = iph->ttl - 1;
 410 +                       iph->check = 0;
 411 +                       iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
 412 +               } else {
 413 +                       ip_decrease_ttl(iph);
 414 +               }
 415 +       }
 416 +
 417 +       if ((route_info->flags & IPT_ROUTE_TEE)) {
 418 +               /*
 419 +                * Copy the *pskb, and route the copy. Will later return
 420 +                * IPT_CONTINUE for the original skb, which should continue
 421 +                * on its way as if nothing happened. The copy should be
 422 +                * independantly delivered to the ROUTE --gw.
 423 +                */
 424 +               skb = skb_copy(*pskb, GFP_ATOMIC);
 425 +               if (!skb) {
 426 +                       if (net_ratelimit())
 427 +                               DEBUGP(KERN_DEBUG "ipt_ROUTE: copy failed!\n");
 428 +                       return IPT_CONTINUE;
 429 +               }
 430 +       }
 431 +
 432 +       /* Tell conntrack to forget this packet since it may get confused
 433 +        * when a packet is leaving with dst address == our address.
 434 +        * Good idea ? Dunno. Need advice.
 435 +        *
 436 +        * NEW: mark the skb with our &route_tee_track, so we avoid looping
 437 +        * on any already routed packet.
 438 +        */
 439 +       if (!(route_info->flags & IPT_ROUTE_CONTINUE)) {
 440 +               nf_conntrack_put(skb->nfct);
 441 +               skb->nfct = &route_tee_track.ct_general;
 442 +               skb->nfctinfo = IP_CT_NEW;
 443 +               nf_conntrack_get(skb->nfct);
 444 +       }
 445 +
 446 +       if (route_info->oif[0] != '\0') {
 447 +               res = route_oif(route_info, skb);
 448 +       } else if (route_info->iif[0] != '\0') {
 449 +               res = route_iif(route_info, skb);
 450 +       } else if (route_info->gw) {
 451 +               res = route_gw(route_info, skb);
 452 +       } else {
 453 +               if (net_ratelimit())
 454 +                       DEBUGP(KERN_DEBUG "ipt_ROUTE: no parameter !\n");
 455 +               res = IPT_CONTINUE;
 456 +       }
 457 +
 458 +       if ((route_info->flags & IPT_ROUTE_TEE))
 459 +               res = IPT_CONTINUE;
 460 +
 461 +       return res;
 462 +}
 463 +
 464 +
 465 +static bool ipt_route_checkentry(const char *tablename,
 466 +                               const void *e,
 467 +                               const struct xt_target *target,
 468 +                               void *targinfo,
 469 +                               unsigned int hook_mask)
 470 +{
 471 +       if (strcmp(tablename, "mangle") != 0) {
 472 +               printk("ipt_ROUTE: bad table `%s', use the `mangle' table.\n",
 473 +                      tablename);
 474 +               return 0;
 475 +       }
 476 +
 477 +       if (hook_mask & ~(  (1 << NF_IP_PRE_ROUTING)
 478 +                           | (1 << NF_IP_LOCAL_IN)
 479 +                           | (1 << NF_IP_FORWARD)
 480 +                           | (1 << NF_IP_LOCAL_OUT)
 481 +                           | (1 << NF_IP_POST_ROUTING))) {
 482 +               printk("ipt_ROUTE: bad hook\n");
 483 +               return 0;
 484 +       }
 485 +
 486 +       return 1;
 487 +}
 488 +
 489 +
 490 +static struct ipt_target ipt_route_reg = {
 491 +       .name = "ROUTE",
 492 +       .target = ipt_route_target,
 493 +       .targetsize = sizeof(struct ipt_route_target_info),
 494 +       .checkentry = ipt_route_checkentry,
 495 +       .me = THIS_MODULE,
 496 +};
 497 +
 498 +static int __init init(void)
 499 +{
 500 +       /* Set up fake conntrack (stolen from raw.patch):
 501 +           - to never be deleted, not in any hashes */
 502 +       atomic_set(&route_tee_track.ct_general.use, 1);
 503 +       /*  - and look it like as a confirmed connection */
 504 +       set_bit(IPS_CONFIRMED_BIT, &route_tee_track.status);
 505 +       /* Initialize fake conntrack so that NAT will skip it */
 506 +       route_tee_track.status |= IPS_NAT_DONE_MASK;
 507 +
 508 +       return xt_register_target(&ipt_route_reg);
 509 +}
 510 +
 511 +
 512 +static void __exit fini(void)
 513 +{
 514 +       xt_unregister_target(&ipt_route_reg);
 515 +}
 516 +
 517 +module_init(init);
 518 +module_exit(fini);
 519 --- a/net/ipv4/netfilter/Kconfig
 520 +++ b/net/ipv4/netfilter/Kconfig
 521 @@ -546,5 +546,22 @@ config IP_NF_TARGET_SET
 522           To compile it as a module, choose M here.  If unsure, say N.
 523
 524
 525 +config IP_NF_TARGET_ROUTE
 526 +       tristate  'ROUTE target support'
 527 +       depends on IP_NF_MANGLE
 528 +       help
 529 +         This option adds a `ROUTE' target, which enables you to setup unusual
 530 +         routes. For example, the ROUTE lets you route a received packet through
 531 +         an interface or towards a host, even if the regular destination of the
 532 +         packet is the router itself. The ROUTE target is also able to change the
 533 +         incoming interface of a packet.
 534 +
 535 +         The target can be or not a final target. It has to be used inside the
 536 +         mangle table.
 537 +
 538 +         If you want to compile it as a module, say M here and read
 539 +         Documentation/modules.txt.  The module will be called ipt_ROUTE.o.
 540 +         If unsure, say `N'.
 541 +
 542  endmenu
 543
 544 --- a/net/ipv4/netfilter/Makefile
 545 +++ b/net/ipv4/netfilter/Makefile
 546 @@ -59,6 +59,7 @@ obj-$(CONFIG_IP_NF_TARGET_ECN) += ipt_EC
 547  obj-$(CONFIG_IP_NF_TARGET_IMQ) += ipt_IMQ.o
 548  obj-$(CONFIG_IP_NF_TARGET_MASQUERADE) += ipt_MASQUERADE.o
 549  obj-$(CONFIG_IP_NF_TARGET_REDIRECT) += ipt_REDIRECT.o
 550 +obj-$(CONFIG_IP_NF_TARGET_ROUTE) += ipt_ROUTE.o
 551  obj-$(CONFIG_IP_NF_TARGET_NETMAP) += ipt_NETMAP.o
 552  obj-$(CONFIG_IP_NF_TARGET_SAME) += ipt_SAME.o
 553  obj-$(CONFIG_IP_NF_TARGET_LOG) += ipt_LOG.o
 554 --- a/net/ipv6/ndisc.c
 555 +++ b/net/ipv6/ndisc.c
 556 @@ -154,6 +154,8 @@ struct neigh_table nd_tbl = {
 557         .gc_thresh3 =   1024,
 558  };
 559
 560 +EXPORT_SYMBOL(nd_tbl);
 561 +
 562  /* ND options */
 563  struct ndisc_options {
 564         struct nd_opt_hdr *nd_opt_array[__ND_OPT_ARRAY_MAX];
 565 --- /dev/null
 566 +++ b/net/ipv6/netfilter/ip6t_ROUTE.c
 567 @@ -0,0 +1,330 @@
 568 +/*
 569 + * This implements the ROUTE v6 target, which enables you to setup unusual
 570 + * routes not supported by the standard kernel routing table.
 571 + *
 572 + * Copyright (C) 2003 Cedric de Launois <delaunois@info.ucl.ac.be>
 573 + *
 574 + * v 1.1 2004/11/23
 575 + *
 576 + * This software is distributed under GNU GPL v2, 1991
 577 + */
 578 +
 579 +#include <linux/module.h>
 580 +#include <linux/skbuff.h>
 581 +#include <linux/ipv6.h>
 582 +#include <linux/netfilter_ipv6/ip6_tables.h>
 583 +#include <linux/netfilter_ipv6/ip6t_ROUTE.h>
 584 +#include <linux/netdevice.h>
 585 +#include <linux/version.h>
 586 +#include <net/ipv6.h>
 587 +#include <net/ndisc.h>
 588 +#include <net/ip6_route.h>
 589 +#include <linux/icmpv6.h>
 590 +
 591 +#if 1
 592 +#define DEBUGP printk
 593 +#else
 594 +#define DEBUGP(format, args...)
 595 +#endif
 596 +
 597 +#define NIP6(addr) \
 598 +       ntohs((addr).s6_addr16[0]), \
 599 +       ntohs((addr).s6_addr16[1]), \
 600 +       ntohs((addr).s6_addr16[2]), \
 601 +       ntohs((addr).s6_addr16[3]), \
 602 +       ntohs((addr).s6_addr16[4]), \
 603 +       ntohs((addr).s6_addr16[5]), \
 604 +       ntohs((addr).s6_addr16[6]), \
 605 +       ntohs((addr).s6_addr16[7])
 606 +
 607 +/* Route the packet according to the routing keys specified in
 608 + * route_info. Keys are :
 609 + *  - ifindex :
 610 + *      0 if no oif preferred,
 611 + *      otherwise set to the index of the desired oif
 612 + *  - route_info->gw :
 613 + *      0 if no gateway specified,
 614 + *      otherwise set to the next host to which the pkt must be routed
 615 + * If success, skb->dev is the output device to which the packet must
 616 + * be sent and skb->dst is not NULL
 617 + *
 618 + * RETURN:  1 if the packet was succesfully routed to the
 619 + *            destination desired
 620 + *          0 if the kernel routing table could not route the packet
 621 + *            according to the keys specified
 622 + */
 623 +static int
 624 +route6(struct sk_buff *skb,
 625 +       unsigned int ifindex,
 626 +       const struct ip6t_route_target_info *route_info)
 627 +{
 628 +       struct rt6_info *rt = NULL;
 629 +       struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 630 +       struct in6_addr *gw = (struct in6_addr*)&route_info->gw;
 631 +
 632 +       DEBUGP("ip6t_ROUTE: called with: ");
 633 +       DEBUGP("DST=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(ipv6h->daddr));
 634 +       DEBUGP("GATEWAY=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(*gw));
 635 +       DEBUGP("OUT=%s\n", route_info->oif);
 636 +
 637 +       if (ipv6_addr_any(gw))
 638 +               rt = rt6_lookup(&ipv6h->daddr, &ipv6h->saddr, ifindex, 1);
 639 +       else
 640 +               rt = rt6_lookup(gw, &ipv6h->saddr, ifindex, 1);
 641 +
 642 +       if (!rt)
 643 +               goto no_route;
 644 +
 645 +       DEBUGP("ip6t_ROUTE: routing gives: ");
 646 +       DEBUGP("DST=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(rt->rt6i_dst.addr));
 647 +       DEBUGP("GATEWAY=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(rt->rt6i_gateway));
 648 +       DEBUGP("OUT=%s\n", rt->rt6i_dev->name);
 649 +
 650 +       if (ifindex && rt->rt6i_dev->ifindex!=ifindex)
 651 +               goto wrong_route;
 652 +
 653 +       if (!rt->rt6i_nexthop) {
 654 +               DEBUGP("ip6t_ROUTE: discovering neighbour\n");
 655 +               rt->rt6i_nexthop = ndisc_get_neigh(rt->rt6i_dev, &rt->rt6i_dst.addr);
 656 +       }
 657 +
 658 +       /* Drop old route. */
 659 +       dst_release(skb->dst);
 660 +       skb->dst = &rt->u.dst;
 661 +       skb->dev = rt->rt6i_dev;
 662 +       return 1;
 663 +
 664 + wrong_route:
 665 +       dst_release(&rt->u.dst);
 666 + no_route:
 667 +       if (!net_ratelimit())
 668 +               return 0;
 669 +
 670 +       printk("ip6t_ROUTE: no explicit route found ");
 671 +       if (ifindex)
 672 +               printk("via interface %s ", route_info->oif);
 673 +       if (!ipv6_addr_any(gw))
 674 +               printk("via gateway %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x", NIP6(*gw));
 675 +       printk("\n");
 676 +       return 0;
 677 +}
 678 +
 679 +
 680 +/* Stolen from ip6_output_finish
 681 + * PRE : skb->dev is set to the device we are leaving by
 682 + *       skb->dst is not NULL
 683 + * POST: the packet is sent with the link layer header pushed
 684 + *       the packet is destroyed
 685 + */
 686 +static void ip_direct_send(struct sk_buff *skb)
 687 +{
 688 +       struct dst_entry *dst = skb->dst;
 689 +       struct hh_cache *hh = dst->hh;
 690 +
 691 +       if (hh) {
 692 +               read_lock_bh(&hh->hh_lock);
 693 +               memcpy(skb->data - 16, hh->hh_data, 16);
 694 +               read_unlock_bh(&hh->hh_lock);
 695 +               skb_push(skb, hh->hh_len);
 696 +               hh->hh_output(skb);
 697 +       } else if (dst->neighbour)
 698 +               dst->neighbour->output(skb);
 699 +       else {
 700 +               if (net_ratelimit())
 701 +                       DEBUGP(KERN_DEBUG "ip6t_ROUTE: no hdr & no neighbour cache!\n");
 702 +               kfree_skb(skb);
 703 +       }
 704 +}
 705 +
 706 +
 707 +static unsigned int
 708 +route6_oif(const struct ip6t_route_target_info *route_info,
 709 +          struct sk_buff *skb)
 710 +{
 711 +       unsigned int ifindex = 0;
 712 +       struct net_device *dev_out = NULL;
 713 +
 714 +       /* The user set the interface name to use.
 715 +        * Getting the current interface index.
 716 +        */
 717 +       if ((dev_out = dev_get_by_name(route_info->oif))) {
 718 +               ifindex = dev_out->ifindex;
 719 +       } else {
 720 +               /* Unknown interface name : packet dropped */
 721 +               if (net_ratelimit())
 722 +                       DEBUGP("ip6t_ROUTE: oif interface %s not found\n", route_info->oif);
 723 +
 724 +               if (route_info->flags & IP6T_ROUTE_CONTINUE)
 725 +                       return IP6T_CONTINUE;
 726 +               else
 727 +                       return NF_DROP;
 728 +       }
 729 +
 730 +       /* Trying the standard way of routing packets */
 731 +       if (route6(skb, ifindex, route_info)) {
 732 +               dev_put(dev_out);
 733 +               if (route_info->flags & IP6T_ROUTE_CONTINUE)
 734 +                       return IP6T_CONTINUE;
 735 +
 736 +               ip_direct_send(skb);
 737 +               return NF_STOLEN;
 738 +       } else
 739 +               return NF_DROP;
 740 +}
 741 +
 742 +
 743 +static unsigned int
 744 +route6_gw(const struct ip6t_route_target_info *route_info,
 745 +         struct sk_buff *skb)
 746 +{
 747 +       if (route6(skb, 0, route_info)) {
 748 +               if (route_info->flags & IP6T_ROUTE_CONTINUE)
 749 +                       return IP6T_CONTINUE;
 750 +
 751 +               ip_direct_send(skb);
 752 +               return NF_STOLEN;
 753 +       } else
 754 +               return NF_DROP;
 755 +}
 756 +
 757 +
 758 +static unsigned int
 759 +ip6t_route_target(struct sk_buff **pskb,
 760 +                 const struct net_device *in,
 761 +                 const struct net_device *out,
 762 +                 unsigned int hooknum,
 763 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,17)
 764 +                 const struct xt_target *target,
 765 +#endif
 766 +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19)
 767 +                 const void *targinfo,
 768 +                 void *userinfo)
 769 +#else
 770 +                 const void *targinfo)
 771 +#endif
 772 +{
 773 +       const struct ip6t_route_target_info *route_info = targinfo;
 774 +       struct sk_buff *skb = *pskb;
 775 +       struct in6_addr *gw = (struct in6_addr*)&route_info->gw;
 776 +       unsigned int res;
 777 +
 778 +       if (route_info->flags & IP6T_ROUTE_CONTINUE)
 779 +               goto do_it;
 780 +
 781 +       /* If we are at PREROUTING or INPUT hook
 782 +        * the TTL isn't decreased by the IP stack
 783 +        */
 784 +       if (hooknum == NF_IP6_PRE_ROUTING ||
 785 +           hooknum == NF_IP6_LOCAL_IN) {
 786 +
 787 +               struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 788 +
 789 +               if (ipv6h->hop_limit <= 1) {
 790 +                       /* Force OUTPUT device used as source address */
 791 +                       skb->dev = skb->dst->dev;
 792 +
 793 +                       icmpv6_send(skb, ICMPV6_TIME_EXCEED,
 794 +                                   ICMPV6_EXC_HOPLIMIT, 0, skb->dev);
 795 +
 796 +                       return NF_DROP;
 797 +               }
 798 +
 799 +               ipv6h->hop_limit--;
 800 +       }
 801 +
 802 +       if ((route_info->flags & IP6T_ROUTE_TEE)) {
 803 +               /*
 804 +                * Copy the *pskb, and route the copy. Will later return
 805 +                * IP6T_CONTINUE for the original skb, which should continue
 806 +                * on its way as if nothing happened. The copy should be
 807 +                * independantly delivered to the ROUTE --gw.
 808 +                */
 809 +               skb = skb_copy(*pskb, GFP_ATOMIC);
 810 +               if (!skb) {
 811 +                       if (net_ratelimit())
 812 +                               DEBUGP(KERN_DEBUG "ip6t_ROUTE: copy failed!\n");
 813 +                       return IP6T_CONTINUE;
 814 +               }
 815 +       }
 816 +
 817 +do_it:
 818 +       if (route_info->oif[0]) {
 819 +               res = route6_oif(route_info, skb);
 820 +       } else if (!ipv6_addr_any(gw)) {
 821 +               res = route6_gw(route_info, skb);
 822 +       } else {
 823 +               if (net_ratelimit())
 824 +                       DEBUGP(KERN_DEBUG "ip6t_ROUTE: no parameter !\n");
 825 +               res = IP6T_CONTINUE;
 826 +       }
 827 +
 828 +       if ((route_info->flags & IP6T_ROUTE_TEE))
 829 +               res = IP6T_CONTINUE;
 830 +
 831 +       return res;
 832 +}
 833 +
 834 +
 835 +static int
 836 +ip6t_route_checkentry(const char *tablename,
 837 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
 838 +                     const void *entry,
 839 +#else
 840 +                     const struct ip6t_entry *entry
 841 +#endif
 842 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,17)
 843 +                     const struct xt_target *target,
 844 +#endif
 845 +                     void *targinfo,
 846 +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19)
 847 +                     unsigned int targinfosize,
 848 +#endif
 849 +                     unsigned int hook_mask)
 850 +{
 851 +       if (strcmp(tablename, "mangle") != 0) {
 852 +               printk("ip6t_ROUTE: can only be called from \"mangle\" table.\n");
 853 +               return 0;
 854 +       }
 855 +
 856 +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19)
 857 +       if (targinfosize != IP6T_ALIGN(sizeof(struct ip6t_route_target_info))) {
 858 +               printk(KERN_WARNING "ip6t_ROUTE: targinfosize %u != %Zu\n",
 859 +                      targinfosize,
 860 +                      IP6T_ALIGN(sizeof(struct ip6t_route_target_info)));
 861 +               return 0;
 862 +       }
 863 +#endif
 864 +
 865 +       return 1;
 866 +}
 867 +
 868 +
 869 +static struct ip6t_target ip6t_route_reg = {
 870 +       .name       = "ROUTE",
 871 +       .target     = ip6t_route_target,
 872 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,17)
 873 +       .targetsize = sizeof(struct ip6t_route_target_info),
 874 +#endif
 875 +       .checkentry = ip6t_route_checkentry,
 876 +       .me         = THIS_MODULE
 877 +};
 878 +
 879 +
 880 +static int __init init(void)
 881 +{
 882 +       printk(KERN_DEBUG "registering ipv6 ROUTE target\n");
 883 +       if (xt_register_target(&ip6t_route_reg))
 884 +               return -EINVAL;
 885 +
 886 +       return 0;
 887 +}
 888 +
 889 +
 890 +static void __exit fini(void)
 891 +{
 892 +       xt_unregister_target(&ip6t_route_reg);
 893 +}
 894 +
 895 +module_init(init);
 896 +module_exit(fini);
 897 +MODULE_LICENSE("GPL");
 898 --- a/net/ipv6/netfilter/Kconfig
 899 +++ b/net/ipv6/netfilter/Kconfig
 900 @@ -209,5 +209,18 @@ config IP6_NF_RAW
 901           If you want to compile it as a module, say M here and read
 902           <file:Documentation/kbuild/modules.txt>.  If unsure, say `N'.
 903
 904 +config IP6_NF_TARGET_ROUTE
 905 +       tristate 'ROUTE target support'
 906 +       depends on IP6_NF_MANGLE
 907 +       help
 908 +         This option adds a `ROUTE' target, which enables you to setup unusual
 909 +         routes. The ROUTE target is also able to change the incoming interface
 910 +         of a packet.
 911 +
 912 +         The target can be or not a final target. It has to be used inside the
 913 +         mangle table.
 914 +
 915 +         Not working as a module.
 916 +
 917  endmenu
 918
 919 --- a/net/ipv6/netfilter/Makefile
 920 +++ b/net/ipv6/netfilter/Makefile
 921 @@ -20,6 +20,7 @@ obj-$(CONFIG_IP6_NF_TARGET_LOG) += ip6t_
 922  obj-$(CONFIG_IP6_NF_RAW) += ip6table_raw.o
 923  obj-$(CONFIG_IP6_NF_MATCH_HL) += ip6t_hl.o
 924  obj-$(CONFIG_IP6_NF_TARGET_REJECT) += ip6t_REJECT.o
 925 +obj-$(CONFIG_IP6_NF_TARGET_ROUTE) += ip6t_ROUTE.o
 926  obj-$(CONFIG_IP6_NF_MATCH_MH) += ip6t_mh.o
 927
 928  # objects for l3 independent conntrack