target/linux/generic-2.6/patches-2.6.21/160-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 +1,483 @@
  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 <linux/netfilter_ipv4/ip_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 = skb->nh.iph;
 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 ip_conntrack 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 = skb->nh.iph;
 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 int ipt_route_checkentry(const char *tablename,
 466 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
 467 +                               const void *e,
 468 +#else
 469 +                               const struct ipt_ip *ip,
 470 +#endif
 471 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,17)
 472 +                               const struct xt_target *target,
 473 +#endif
 474 +                               void *targinfo,
 475 +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19)
 476 +                               unsigned int targinfosize,
 477 +#endif
 478 +                               unsigned int hook_mask)
 479 +{
 480 +       if (strcmp(tablename, "mangle") != 0) {
 481 +               printk("ipt_ROUTE: bad table `%s', use the `mangle' table.\n",
 482 +                      tablename);
 483 +               return 0;
 484 +       }
 485 +
 486 +       if (hook_mask & ~(  (1 << NF_IP_PRE_ROUTING)
 487 +                           | (1 << NF_IP_LOCAL_IN)
 488 +                           | (1 << NF_IP_FORWARD)
 489 +                           | (1 << NF_IP_LOCAL_OUT)
 490 +                           | (1 << NF_IP_POST_ROUTING))) {
 491 +               printk("ipt_ROUTE: bad hook\n");
 492 +               return 0;
 493 +       }
 494 +
 495 +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19)
 496 +       if (targinfosize != IPT_ALIGN(sizeof(struct ipt_route_target_info))) {
 497 +               printk(KERN_WARNING "ipt_ROUTE: targinfosize %u != %Zu\n",
 498 +                      targinfosize,
 499 +                      IPT_ALIGN(sizeof(struct ipt_route_target_info)));
 500 +               return 0;
 501 +       }
 502 +#endif
 503 +
 504 +       return 1;
 505 +}
 506 +
 507 +
 508 +static struct ipt_target ipt_route_reg = {
 509 +       .name = "ROUTE",
 510 +       .target = ipt_route_target,
 511 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,17)
 512 +       .targetsize = sizeof(struct ipt_route_target_info),
 513 +#endif
 514 +       .checkentry = ipt_route_checkentry,
 515 +       .me = THIS_MODULE,
 516 +};
 517 +
 518 +static int __init init(void)
 519 +{
 520 +       /* Set up fake conntrack (stolen from raw.patch):
 521 +           - to never be deleted, not in any hashes */
 522 +       atomic_set(&route_tee_track.ct_general.use, 1);
 523 +       /*  - and look it like as a confirmed connection */
 524 +       set_bit(IPS_CONFIRMED_BIT, &route_tee_track.status);
 525 +       /* Initialize fake conntrack so that NAT will skip it */
 526 +       route_tee_track.status |= IPS_NAT_DONE_MASK;
 527 +
 528 +       return xt_register_target(&ipt_route_reg);
 529 +}
 530 +
 531 +
 532 +static void __exit fini(void)
 533 +{
 534 +       xt_unregister_target(&ipt_route_reg);
 535 +}
 536 +
 537 +module_init(init);
 538 +module_exit(fini);
 539 --- a/net/ipv4/netfilter/Kconfig
 540 +++ b/net/ipv4/netfilter/Kconfig
 541 @@ -807,5 +807,22 @@ config IP_NF_TARGET_SET
 542           To compile it as a module, choose M here.  If unsure, say N.
 543
 544
 545 +config IP_NF_TARGET_ROUTE
 546 +       tristate  'ROUTE target support'
 547 +       depends on IP_NF_MANGLE
 548 +       help
 549 +         This option adds a `ROUTE' target, which enables you to setup unusual
 550 +         routes. For example, the ROUTE lets you route a received packet through
 551 +         an interface or towards a host, even if the regular destination of the
 552 +         packet is the router itself. The ROUTE target is also able to change the
 553 +         incoming interface of a packet.
 554 +
 555 +         The target can be or not a final target. It has to be used inside the
 556 +         mangle table.
 557 +
 558 +         If you want to compile it as a module, say M here and read
 559 +         Documentation/modules.txt.  The module will be called ipt_ROUTE.o.
 560 +         If unsure, say `N'.
 561 +
 562  endmenu
 563
 564 --- a/net/ipv4/netfilter/Makefile
 565 +++ b/net/ipv4/netfilter/Makefile
 566 @@ -102,6 +102,7 @@ obj-$(CONFIG_IP_NF_TARGET_ECN) += ipt_EC
 567  obj-$(CONFIG_IP_NF_TARGET_IMQ) += ipt_IMQ.o
 568  obj-$(CONFIG_IP_NF_TARGET_MASQUERADE) += ipt_MASQUERADE.o
 569  obj-$(CONFIG_IP_NF_TARGET_REDIRECT) += ipt_REDIRECT.o
 570 +obj-$(CONFIG_IP_NF_TARGET_ROUTE) += ipt_ROUTE.o
 571  obj-$(CONFIG_IP_NF_TARGET_NETMAP) += ipt_NETMAP.o
 572  obj-$(CONFIG_IP_NF_TARGET_SAME) += ipt_SAME.o
 573  obj-$(CONFIG_IP_NF_NAT_SNMP_BASIC) += ip_nat_snmp_basic.o
 574 --- a/net/ipv6/ipv6_syms.c
 575 +++ b/net/ipv6/ipv6_syms.c
 576 @@ -10,6 +10,7 @@ EXPORT_SYMBOL(icmpv6_send);
 577  EXPORT_SYMBOL(icmpv6_statistics);
 578  EXPORT_SYMBOL(icmpv6_err_convert);
 579  EXPORT_SYMBOL(ndisc_mc_map);
 580 +EXPORT_SYMBOL(nd_tbl);
 581  EXPORT_SYMBOL(register_inet6addr_notifier);
 582  EXPORT_SYMBOL(unregister_inet6addr_notifier);
 583  EXPORT_SYMBOL(ip6_route_output);
 584 --- /dev/null
 585 +++ b/net/ipv6/netfilter/ip6t_ROUTE.c
 586 @@ -0,0 +1,330 @@
 587 +/*
 588 + * This implements the ROUTE v6 target, which enables you to setup unusual
 589 + * routes not supported by the standard kernel routing table.
 590 + *
 591 + * Copyright (C) 2003 Cedric de Launois <delaunois@info.ucl.ac.be>
 592 + *
 593 + * v 1.1 2004/11/23
 594 + *
 595 + * This software is distributed under GNU GPL v2, 1991
 596 + */
 597 +
 598 +#include <linux/module.h>
 599 +#include <linux/skbuff.h>
 600 +#include <linux/ipv6.h>
 601 +#include <linux/netfilter_ipv6/ip6_tables.h>
 602 +#include <linux/netfilter_ipv6/ip6t_ROUTE.h>
 603 +#include <linux/netdevice.h>
 604 +#include <linux/version.h>
 605 +#include <net/ipv6.h>
 606 +#include <net/ndisc.h>
 607 +#include <net/ip6_route.h>
 608 +#include <linux/icmpv6.h>
 609 +
 610 +#if 1
 611 +#define DEBUGP printk
 612 +#else
 613 +#define DEBUGP(format, args...)
 614 +#endif
 615 +
 616 +#define NIP6(addr) \
 617 +       ntohs((addr).s6_addr16[0]), \
 618 +       ntohs((addr).s6_addr16[1]), \
 619 +       ntohs((addr).s6_addr16[2]), \
 620 +       ntohs((addr).s6_addr16[3]), \
 621 +       ntohs((addr).s6_addr16[4]), \
 622 +       ntohs((addr).s6_addr16[5]), \
 623 +       ntohs((addr).s6_addr16[6]), \
 624 +       ntohs((addr).s6_addr16[7])
 625 +
 626 +/* Route the packet according to the routing keys specified in
 627 + * route_info. Keys are :
 628 + *  - ifindex :
 629 + *      0 if no oif preferred,
 630 + *      otherwise set to the index of the desired oif
 631 + *  - route_info->gw :
 632 + *      0 if no gateway specified,
 633 + *      otherwise set to the next host to which the pkt must be routed
 634 + * If success, skb->dev is the output device to which the packet must
 635 + * be sent and skb->dst is not NULL
 636 + *
 637 + * RETURN:  1 if the packet was succesfully routed to the
 638 + *            destination desired
 639 + *          0 if the kernel routing table could not route the packet
 640 + *            according to the keys specified
 641 + */
 642 +static int
 643 +route6(struct sk_buff *skb,
 644 +       unsigned int ifindex,
 645 +       const struct ip6t_route_target_info *route_info)
 646 +{
 647 +       struct rt6_info *rt = NULL;
 648 +       struct ipv6hdr *ipv6h = skb->nh.ipv6h;
 649 +       struct in6_addr *gw = (struct in6_addr*)&route_info->gw;
 650 +
 651 +       DEBUGP("ip6t_ROUTE: called with: ");
 652 +       DEBUGP("DST=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(ipv6h->daddr));
 653 +       DEBUGP("GATEWAY=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(*gw));
 654 +       DEBUGP("OUT=%s\n", route_info->oif);
 655 +
 656 +       if (ipv6_addr_any(gw))
 657 +               rt = rt6_lookup(&ipv6h->daddr, &ipv6h->saddr, ifindex, 1);
 658 +       else
 659 +               rt = rt6_lookup(gw, &ipv6h->saddr, ifindex, 1);
 660 +
 661 +       if (!rt)
 662 +               goto no_route;
 663 +
 664 +       DEBUGP("ip6t_ROUTE: routing gives: ");
 665 +       DEBUGP("DST=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(rt->rt6i_dst.addr));
 666 +       DEBUGP("GATEWAY=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(rt->rt6i_gateway));
 667 +       DEBUGP("OUT=%s\n", rt->rt6i_dev->name);
 668 +
 669 +       if (ifindex && rt->rt6i_dev->ifindex!=ifindex)
 670 +               goto wrong_route;
 671 +
 672 +       if (!rt->rt6i_nexthop) {
 673 +               DEBUGP("ip6t_ROUTE: discovering neighbour\n");
 674 +               rt->rt6i_nexthop = ndisc_get_neigh(rt->rt6i_dev, &rt->rt6i_dst.addr);
 675 +       }
 676 +
 677 +       /* Drop old route. */
 678 +       dst_release(skb->dst);
 679 +       skb->dst = &rt->u.dst;
 680 +       skb->dev = rt->rt6i_dev;
 681 +       return 1;
 682 +
 683 + wrong_route:
 684 +       dst_release(&rt->u.dst);
 685 + no_route:
 686 +       if (!net_ratelimit())
 687 +               return 0;
 688 +
 689 +       printk("ip6t_ROUTE: no explicit route found ");
 690 +       if (ifindex)
 691 +               printk("via interface %s ", route_info->oif);
 692 +       if (!ipv6_addr_any(gw))
 693 +               printk("via gateway %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x", NIP6(*gw));
 694 +       printk("\n");
 695 +       return 0;
 696 +}
 697 +
 698 +
 699 +/* Stolen from ip6_output_finish
 700 + * PRE : skb->dev is set to the device we are leaving by
 701 + *       skb->dst is not NULL
 702 + * POST: the packet is sent with the link layer header pushed
 703 + *       the packet is destroyed
 704 + */
 705 +static void ip_direct_send(struct sk_buff *skb)
 706 +{
 707 +       struct dst_entry *dst = skb->dst;
 708 +       struct hh_cache *hh = dst->hh;
 709 +
 710 +       if (hh) {
 711 +               read_lock_bh(&hh->hh_lock);
 712 +               memcpy(skb->data - 16, hh->hh_data, 16);
 713 +               read_unlock_bh(&hh->hh_lock);
 714 +               skb_push(skb, hh->hh_len);
 715 +               hh->hh_output(skb);
 716 +       } else if (dst->neighbour)
 717 +               dst->neighbour->output(skb);
 718 +       else {
 719 +               if (net_ratelimit())
 720 +                       DEBUGP(KERN_DEBUG "ip6t_ROUTE: no hdr & no neighbour cache!\n");
 721 +               kfree_skb(skb);
 722 +       }
 723 +}
 724 +
 725 +
 726 +static unsigned int
 727 +route6_oif(const struct ip6t_route_target_info *route_info,
 728 +          struct sk_buff *skb)
 729 +{
 730 +       unsigned int ifindex = 0;
 731 +       struct net_device *dev_out = NULL;
 732 +
 733 +       /* The user set the interface name to use.
 734 +        * Getting the current interface index.
 735 +        */
 736 +       if ((dev_out = dev_get_by_name(route_info->oif))) {
 737 +               ifindex = dev_out->ifindex;
 738 +       } else {
 739 +               /* Unknown interface name : packet dropped */
 740 +               if (net_ratelimit())
 741 +                       DEBUGP("ip6t_ROUTE: oif interface %s not found\n", route_info->oif);
 742 +
 743 +               if (route_info->flags & IP6T_ROUTE_CONTINUE)
 744 +                       return IP6T_CONTINUE;
 745 +               else
 746 +                       return NF_DROP;
 747 +       }
 748 +
 749 +       /* Trying the standard way of routing packets */
 750 +       if (route6(skb, ifindex, route_info)) {
 751 +               dev_put(dev_out);
 752 +               if (route_info->flags & IP6T_ROUTE_CONTINUE)
 753 +                       return IP6T_CONTINUE;
 754 +
 755 +               ip_direct_send(skb);
 756 +               return NF_STOLEN;
 757 +       } else
 758 +               return NF_DROP;
 759 +}
 760 +
 761 +
 762 +static unsigned int
 763 +route6_gw(const struct ip6t_route_target_info *route_info,
 764 +         struct sk_buff *skb)
 765 +{
 766 +       if (route6(skb, 0, route_info)) {
 767 +               if (route_info->flags & IP6T_ROUTE_CONTINUE)
 768 +                       return IP6T_CONTINUE;
 769 +
 770 +               ip_direct_send(skb);
 771 +               return NF_STOLEN;
 772 +       } else
 773 +               return NF_DROP;
 774 +}
 775 +
 776 +
 777 +static unsigned int
 778 +ip6t_route_target(struct sk_buff **pskb,
 779 +                 const struct net_device *in,
 780 +                 const struct net_device *out,
 781 +                 unsigned int hooknum,
 782 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,17)
 783 +                 const struct xt_target *target,
 784 +#endif
 785 +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19)
 786 +                 const void *targinfo,
 787 +                 void *userinfo)
 788 +#else
 789 +                 const void *targinfo)
 790 +#endif
 791 +{
 792 +       const struct ip6t_route_target_info *route_info = targinfo;
 793 +       struct sk_buff *skb = *pskb;
 794 +       struct in6_addr *gw = (struct in6_addr*)&route_info->gw;
 795 +       unsigned int res;
 796 +
 797 +       if (route_info->flags & IP6T_ROUTE_CONTINUE)
 798 +               goto do_it;
 799 +
 800 +       /* If we are at PREROUTING or INPUT hook
 801 +        * the TTL isn't decreased by the IP stack
 802 +        */
 803 +       if (hooknum == NF_IP6_PRE_ROUTING ||
 804 +           hooknum == NF_IP6_LOCAL_IN) {
 805 +
 806 +               struct ipv6hdr *ipv6h = skb->nh.ipv6h;
 807 +
 808 +               if (ipv6h->hop_limit <= 1) {
 809 +                       /* Force OUTPUT device used as source address */
 810 +                       skb->dev = skb->dst->dev;
 811 +
 812 +                       icmpv6_send(skb, ICMPV6_TIME_EXCEED,
 813 +                                   ICMPV6_EXC_HOPLIMIT, 0, skb->dev);
 814 +
 815 +                       return NF_DROP;
 816 +               }
 817 +
 818 +               ipv6h->hop_limit--;
 819 +       }
 820 +
 821 +       if ((route_info->flags & IP6T_ROUTE_TEE)) {
 822 +               /*
 823 +                * Copy the *pskb, and route the copy. Will later return
 824 +                * IP6T_CONTINUE for the original skb, which should continue
 825 +                * on its way as if nothing happened. The copy should be
 826 +                * independantly delivered to the ROUTE --gw.
 827 +                */
 828 +               skb = skb_copy(*pskb, GFP_ATOMIC);
 829 +               if (!skb) {
 830 +                       if (net_ratelimit())
 831 +                               DEBUGP(KERN_DEBUG "ip6t_ROUTE: copy failed!\n");
 832 +                       return IP6T_CONTINUE;
 833 +               }
 834 +       }
 835 +
 836 +do_it:
 837 +       if (route_info->oif[0]) {
 838 +               res = route6_oif(route_info, skb);
 839 +       } else if (!ipv6_addr_any(gw)) {
 840 +               res = route6_gw(route_info, skb);
 841 +       } else {
 842 +               if (net_ratelimit())
 843 +                       DEBUGP(KERN_DEBUG "ip6t_ROUTE: no parameter !\n");
 844 +               res = IP6T_CONTINUE;
 845 +       }
 846 +
 847 +       if ((route_info->flags & IP6T_ROUTE_TEE))
 848 +               res = IP6T_CONTINUE;
 849 +
 850 +       return res;
 851 +}
 852 +
 853 +
 854 +static int
 855 +ip6t_route_checkentry(const char *tablename,
 856 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,16)
 857 +                     const void *entry,
 858 +#else
 859 +                     const struct ip6t_entry *entry
 860 +#endif
 861 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,17)
 862 +                     const struct xt_target *target,
 863 +#endif
 864 +                     void *targinfo,
 865 +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19)
 866 +                     unsigned int targinfosize,
 867 +#endif
 868 +                     unsigned int hook_mask)
 869 +{
 870 +       if (strcmp(tablename, "mangle") != 0) {
 871 +               printk("ip6t_ROUTE: can only be called from \"mangle\" table.\n");
 872 +               return 0;
 873 +       }
 874 +
 875 +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19)
 876 +       if (targinfosize != IP6T_ALIGN(sizeof(struct ip6t_route_target_info))) {
 877 +               printk(KERN_WARNING "ip6t_ROUTE: targinfosize %u != %Zu\n",
 878 +                      targinfosize,
 879 +                      IP6T_ALIGN(sizeof(struct ip6t_route_target_info)));
 880 +               return 0;
 881 +       }
 882 +#endif
 883 +
 884 +       return 1;
 885 +}
 886 +
 887 +
 888 +static struct ip6t_target ip6t_route_reg = {
 889 +       .name       = "ROUTE",
 890 +       .target     = ip6t_route_target,
 891 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,17)
 892 +       .targetsize = sizeof(struct ip6t_route_target_info),
 893 +#endif
 894 +       .checkentry = ip6t_route_checkentry,
 895 +       .me         = THIS_MODULE
 896 +};
 897 +
 898 +
 899 +static int __init init(void)
 900 +{
 901 +       printk(KERN_DEBUG "registering ipv6 ROUTE target\n");
 902 +       if (xt_register_target(&ip6t_route_reg))
 903 +               return -EINVAL;
 904 +
 905 +       return 0;
 906 +}
 907 +
 908 +
 909 +static void __exit fini(void)
 910 +{
 911 +       xt_unregister_target(&ip6t_route_reg);
 912 +}
 913 +
 914 +module_init(init);
 915 +module_exit(fini);
 916 +MODULE_LICENSE("GPL");
 917 --- a/net/ipv6/netfilter/Kconfig
 918 +++ b/net/ipv6/netfilter/Kconfig
 919 @@ -209,5 +209,18 @@ config IP6_NF_RAW
 920           If you want to compile it as a module, say M here and read
 921           <file:Documentation/modules.txt>.  If unsure, say `N'.
 922
 923 +config IP6_NF_TARGET_ROUTE
 924 +       tristate 'ROUTE target support'
 925 +       depends on IP6_NF_MANGLE
 926 +       help
 927 +         This option adds a `ROUTE' target, which enables you to setup unusual
 928 +         routes. The ROUTE target is also able to change the incoming interface
 929 +         of a packet.
 930 +
 931 +         The target can be or not a final target. It has to be used inside the
 932 +         mangle table.
 933 +
 934 +         Not working as a module.
 935 +
 936  endmenu
 937
 938 --- a/net/ipv6/netfilter/Makefile
 939 +++ b/net/ipv6/netfilter/Makefile
 940 @@ -20,6 +20,7 @@ obj-$(CONFIG_IP6_NF_TARGET_LOG) += ip6t_
 941  obj-$(CONFIG_IP6_NF_RAW) += ip6table_raw.o
 942  obj-$(CONFIG_IP6_NF_MATCH_HL) += ip6t_hl.o
 943  obj-$(CONFIG_IP6_NF_TARGET_REJECT) += ip6t_REJECT.o
 944 +obj-$(CONFIG_IP6_NF_TARGET_ROUTE) += ip6t_ROUTE.o
 945  obj-$(CONFIG_IP6_NF_MATCH_MH) += ip6t_mh.o
 946
 947  # objects for l3 independent conntrack