target/linux/generic-2.6/patches-2.6.24/170-netfilter_chaostables.patch

   1 Index: linux-2.6.23/include/linux/netfilter/oot_conntrack.h
   2 ===================================================================
   3 --- /dev/null   1970-01-01 00:00:00.000000000 +0000
   4 +++ linux-2.6.23/include/linux/netfilter/oot_conntrack.h        2007-10-10 13:52:59.000000000 +0800
   5 @@ -0,0 +1,5 @@
   6 +#if defined(CONFIG_IP_NF_CONNTRACK) || defined(CONFIG_IP_NF_CONNTRACK_MODULE)
   7 +#      include <linux/netfilter_ipv4/ip_conntrack.h>
   8 +#else /* linux-2.6.20+ */
   9 +#      include <net/netfilter/nf_nat_rule.h>
  10 +#endif
  11 Index: linux-2.6.23/include/linux/netfilter/oot_trans.h
  12 ===================================================================
  13 --- /dev/null   1970-01-01 00:00:00.000000000 +0000
  14 +++ linux-2.6.23/include/linux/netfilter/oot_trans.h    2007-10-10 13:52:59.000000000 +0800
  15 @@ -0,0 +1,14 @@
  16 +/* Out of tree workarounds */
  17 +#include <linux/version.h>
  18 +#if LINUX_VERSION_CODE <= KERNEL_VERSION(2, 6, 18)
  19 +#      define HAVE_MATCHINFOSIZE 1
  20 +#      define HAVE_TARGUSERINFO 1
  21 +#      define HAVE_TARGINFOSIZE 1
  22 +#endif
  23 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 20)
  24 +#      define nfmark mark
  25 +#endif
  26 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 21)
  27 +#      define tcp_v4_check(tcph, tcph_sz, s, d, csp) \
  28 +               tcp_v4_check((tcph_sz), (s), (d), (csp))
  29 +#endif
  30 Index: linux-2.6.23/include/linux/netfilter/xt_CHAOS.h
  31 ===================================================================
  32 --- /dev/null   1970-01-01 00:00:00.000000000 +0000
  33 +++ linux-2.6.23/include/linux/netfilter/xt_CHAOS.h     2007-10-10 13:52:59.000000000 +0800
  34 @@ -0,0 +1,14 @@
  35 +#ifndef _LINUX_XT_CHAOS_H
  36 +#define _LINUX_XT_CHAOS_H 1
  37 +
  38 +enum xt_chaos_variant {
  39 +       XTCHAOS_NORMAL,
  40 +       XTCHAOS_TARPIT,
  41 +       XTCHAOS_DELUDE,
  42 +};
  43 +
  44 +struct xt_chaos_info {
  45 +       enum xt_chaos_variant variant;
  46 +};
  47 +
  48 +#endif /* _LINUX_XT_CHAOS_H */
  49 Index: linux-2.6.23/include/linux/netfilter/xt_portscan.h
  50 ===================================================================
  51 --- /dev/null   1970-01-01 00:00:00.000000000 +0000
  52 +++ linux-2.6.23/include/linux/netfilter/xt_portscan.h  2007-10-10 13:52:59.000000000 +0800
  53 @@ -0,0 +1,8 @@
  54 +#ifndef _LINUX_XT_PORTSCAN_H
  55 +#define _LINUX_XT_PORTSCAN_H 1
  56 +
  57 +struct xt_portscan_info {
  58 +       unsigned int match_stealth, match_syn, match_cn, match_gr;
  59 +};
  60 +
  61 +#endif /* _LINUX_XT_PORTSCAN_H */
  62 Index: linux-2.6.23/net/netfilter/find_match.c
  63 ===================================================================
  64 --- /dev/null   1970-01-01 00:00:00.000000000 +0000
  65 +++ linux-2.6.23/net/netfilter/find_match.c     2007-10-10 13:52:59.000000000 +0800
  66 @@ -0,0 +1,39 @@
  67 +/*
  68 +    xt_request_find_match
  69 +    by Jan Engelhardt <jengelh [at] gmx de>, 2006 - 2007
  70 +
  71 +    Based upon linux-2.6.18.5/net/netfilter/x_tables.c:
  72 +    Copyright (C) 2006-2006 Harald Welte <laforge@netfilter.org>
  73 +    This program is free software; you can redistribute it and/or modify
  74 +    it under the terms of the GNU General Public License version 2 as
  75 +    published by the Free Software Foundation.
  76 +*/
  77 +#include <linux/err.h>
  78 +#include <linux/netfilter_arp.h>
  79 +#include <linux/socket.h>
  80 +#include <linux/netfilter/x_tables.h>
  81 +
  82 +/*
  83 + * Yeah this code is sub-optimal, but the function is missing in
  84 + * mainline so far. -jengelh
  85 + */
  86 +static struct xt_match *xt_request_find_match_lo(int af, const char *name,
  87 +    u8 revision)
  88 +{
  89 +       static const char *const xt_prefix[] = {
  90 +               [AF_INET]  = "ip",
  91 +               [AF_INET6] = "ip6",
  92 +               [NF_ARP]   = "arp",
  93 +       };
  94 +       struct xt_match *match;
  95 +
  96 +       match = try_then_request_module(xt_find_match(af, name, revision),
  97 +               "%st_%s", xt_prefix[af], name);
  98 +       if(IS_ERR(match) || match == NULL)
  99 +               return NULL;
 100 +
 101 +       return match;
 102 +}
 103 +
 104 +/* In case it goes into mainline, let this out-of-tree package compile */
 105 +#define xt_request_find_match xt_request_find_match_lo
 106 Index: linux-2.6.23/net/netfilter/Kconfig
 107 ===================================================================
 108 --- linux-2.6.23.orig/net/netfilter/Kconfig     2007-10-10 04:31:38.000000000 +0800
 109 +++ linux-2.6.23/net/netfilter/Kconfig  2007-10-10 13:53:04.000000000 +0800
 110 @@ -265,6 +265,14 @@
 111
 112  # alphabetically ordered list of targets
 113
 114 +config NETFILTER_XT_TARGET_CHAOS
 115 +       tristate '"CHAOS" target support'
 116 +       depends on NETFILTER_XTABLES
 117 +       help
 118 +         This option adds a `CHAOS' target.
 119 +
 120 +         To compile it as a module, choose M here.  If unsure, say N.
 121 +
 122  config NETFILTER_XT_TARGET_CLASSIFY
 123         tristate '"CLASSIFY" target support'
 124         depends on NETFILTER_XTABLES
 125 @@ -292,6 +300,14 @@
 126           <file:Documentation/kbuild/modules.txt>.  The module will be called
 127           ipt_CONNMARK.ko.  If unsure, say `N'.
 128
 129 +config NETFILTER_XT_TARGET_DELUDE
 130 +       tristate '"DELUDE" target support'
 131 +       depends on NETFILTER_XTABLES
 132 +       help
 133 +         This option adds a `DELUDE' target.
 134 +
 135 +         To compile it as a module, choose M here.  If unsure, say N.
 136 +
 137  config NETFILTER_XT_TARGET_DSCP
 138         tristate '"DSCP" target support'
 139         depends on NETFILTER_XTABLES
 140 @@ -556,6 +572,14 @@
 141
 142           To compile it as a module, choose M here.  If unsure, say N.
 143
 144 +config NETFILTER_XT_MATCH_PORTSCAN
 145 +       tristate '"portscan" match support'
 146 +       depends on NETFILTER_XTABLES
 147 +       help
 148 +         This option adds a 'portscan' match support.
 149 +
 150 +         To compile it as a module, choose M here.  If unsure, say N.
 151 +
 152  config NETFILTER_XT_MATCH_MULTIPORT
 153         tristate "Multiple port match support"
 154         depends on NETFILTER_XTABLES
 155 Index: linux-2.6.23/net/netfilter/Makefile
 156 ===================================================================
 157 --- linux-2.6.23.orig/net/netfilter/Makefile    2007-10-10 04:31:38.000000000 +0800
 158 +++ linux-2.6.23/net/netfilter/Makefile 2007-10-10 13:52:59.000000000 +0800
 159 @@ -49,6 +49,8 @@
 160  obj-$(CONFIG_NETFILTER_XT_TARGET_SECMARK) += xt_SECMARK.o
 161  obj-$(CONFIG_NETFILTER_XT_TARGET_TCPMSS) += xt_TCPMSS.o
 162  obj-$(CONFIG_NETFILTER_XT_TARGET_TRACE) += xt_TRACE.o
 163 +obj-$(CONFIG_NETFILTER_XT_TARGET_CHAOS) += xt_CHAOS.o
 164 +obj-$(CONFIG_NETFILTER_XT_TARGET_DELUDE) += xt_DELUDE.o
 165
 166  # matches
 167  obj-$(CONFIG_NETFILTER_XT_MATCH_COMMENT) += xt_comment.o
 168 @@ -79,3 +81,4 @@
 169  obj-$(CONFIG_NETFILTER_XT_MATCH_TCPMSS) += xt_tcpmss.o
 170  obj-$(CONFIG_NETFILTER_XT_MATCH_TIME) += xt_time.o
 171  obj-$(CONFIG_NETFILTER_XT_MATCH_U32) += xt_u32.o
 172 +obj-$(CONFIG_NETFILTER_XT_MATCH_PORTSCAN) += xt_portscan.o
 173 Index: linux-2.6.23/net/netfilter/xt_CHAOS.c
 174 ===================================================================
 175 --- /dev/null   1970-01-01 00:00:00.000000000 +0000
 176 +++ linux-2.6.23/net/netfilter/xt_CHAOS.c       2007-10-10 13:52:59.000000000 +0800
 177 @@ -0,0 +1,205 @@
 178 +/*
 179 +       CHAOS target for netfilter
 180 +
 181 +       Copyright © Jan Engelhardt <jengelh [at] gmx de>, 2006 - 2007
 182 +       This program is free software; you can redistribute it and/or modify
 183 +       it under the terms of the GNU General Public License version 2 as
 184 +       published by the Free Software Foundation.
 185 +*/
 186 +#include <linux/icmp.h>
 187 +#include <linux/in.h>
 188 +#include <linux/ip.h>
 189 +#include <linux/module.h>
 190 +#include <linux/skbuff.h>
 191 +#include <linux/stat.h>
 192 +#include <linux/netfilter/x_tables.h>
 193 +#include <linux/netfilter/xt_tcpudp.h>
 194 +#include <linux/netfilter_ipv4/ipt_REJECT.h>
 195 +#include <net/ip.h>
 196 +#include <linux/netfilter/xt_CHAOS.h>
 197 +#include "find_match.c"
 198 +#include <linux/netfilter/oot_trans.h>
 199 +#define PFX KBUILD_MODNAME ": "
 200 +
 201 +/* Module parameters */
 202 +static unsigned int reject_percentage = ~0U * .01;
 203 +static unsigned int delude_percentage = ~0U * .0101;
 204 +module_param(reject_percentage, uint, S_IRUGO | S_IWUSR);
 205 +module_param(delude_percentage, uint, S_IRUGO | S_IWUSR);
 206 +
 207 +/* References to other matches/targets */
 208 +static struct xt_match *xm_tcp;
 209 +static struct xt_target *xt_delude, *xt_reject, *xt_tarpit;
 210 +
 211 +static int have_delude, have_tarpit;
 212 +
 213 +/* Static data for other matches/targets */
 214 +static const struct ipt_reject_info reject_params = {
 215 +       .with = ICMP_HOST_UNREACH,
 216 +};
 217 +
 218 +static const struct xt_tcp tcp_params = {
 219 +       .spts = {0, ~0},
 220 +       .dpts = {0, ~0},
 221 +};
 222 +
 223 +/* CHAOS functions */
 224 +static void xt_chaos_total(const struct xt_chaos_info *info,
 225 +    struct sk_buff **pskb, const struct net_device *in,
 226 +    const struct net_device *out, unsigned int hooknum)
 227 +{
 228 +       const int protoff = ip_hdrlen(*pskb);
 229 +       const int offset  = ntohs(ip_hdr(*pskb)->frag_off) & IP_OFFSET;
 230 +       const struct xt_target *destiny;
 231 +       bool hotdrop = false;
 232 +       int ret;
 233 +
 234 +       ret = xm_tcp->match(*pskb, in, out, xm_tcp, &tcp_params,
 235 +                           offset, protoff, &hotdrop);
 236 +       if(!ret || hotdrop || (unsigned int)net_random() > delude_percentage)
 237 +               return;
 238 +
 239 +       destiny = (info->variant == XTCHAOS_TARPIT) ? xt_tarpit : xt_delude;
 240 +#ifdef HAVE_TARGUSERINFO
 241 +       destiny->target(pskb, in, out, hooknum, destiny, NULL, NULL);
 242 +#else
 243 +       destiny->target(pskb, in, out, hooknum, destiny, NULL);
 244 +#endif
 245 +       return;
 246 +}
 247 +
 248 +static unsigned int xt_chaos_target(struct sk_buff **pskb,
 249 +    const struct net_device *in, const struct net_device *out,
 250 +    unsigned int hooknum, const struct xt_target *target, const void *targinfo
 251 +#ifdef HAVE_TARGUSERINFO
 252 +    ,
 253 +    void *userinfo
 254 +#endif
 255 +    )
 256 +{
 257 +       /* Equivalent to:
 258 +        * -A chaos -m statistic --mode random --probability \
 259 +        *         $reject_percentage -j REJECT --reject-with host-unreach;
 260 +        * -A chaos -p tcp -m statistic --mode random --probability \
 261 +        *         $delude_percentage -j DELUDE;
 262 +        * -A chaos -j DROP;
 263 +        */
 264 +       const struct xt_chaos_info *info = targinfo;
 265 +
 266 +       if((unsigned int)net_random() <= reject_percentage)
 267 +#ifdef HAVE_TARGUSERINFO
 268 +               return xt_reject->target(pskb, in, out, hooknum, target,
 269 +                      &reject_params, userinfo);
 270 +#else
 271 +               return xt_reject->target(pskb, in, out, hooknum, target,
 272 +                      &reject_params);
 273 +#endif
 274 +
 275 +       /* TARPIT/DELUDE may not be called from the OUTPUT chain */
 276 +       if(ip_hdr(*pskb)->protocol == IPPROTO_TCP &&
 277 +         info->variant != XTCHAOS_NORMAL && hooknum != NF_IP_LOCAL_OUT)
 278 +               xt_chaos_total(info, pskb, in, out, hooknum);
 279 +
 280 +       return NF_DROP;
 281 +}
 282 +
 283 +static bool xt_chaos_checkentry(const char *tablename, const void *entry,
 284 +    const struct xt_target *target, void *targinfo,
 285 +#ifdef HAVE_TARGINFOSIZE
 286 +    unsigned int targinfosize,
 287 +#endif
 288 +    unsigned int hook_mask)
 289 +{
 290 +       const struct xt_chaos_info *info = targinfo;
 291 +       if(info->variant == XTCHAOS_DELUDE && !have_delude) {
 292 +               printk(KERN_WARNING PFX "Error: Cannot use --delude when "
 293 +                      "DELUDE module not available\n");
 294 +               return false;
 295 +       }
 296 +       if(info->variant == XTCHAOS_TARPIT && !have_tarpit) {
 297 +               printk(KERN_WARNING PFX "Error: Cannot use --tarpit when "
 298 +                      "TARPIT module not available\n");
 299 +               return false;
 300 +       }
 301 +       return true;
 302 +}
 303 +
 304 +static struct xt_target xt_chaos_info = {
 305 +       .name       = "CHAOS",
 306 +       .target     = xt_chaos_target,
 307 +       .checkentry = xt_chaos_checkentry,
 308 +       .table      = "filter",
 309 +       .targetsize = sizeof(struct xt_chaos_info),
 310 +       .hooks      = (1 << NF_IP_LOCAL_IN) | (1 << NF_IP_FORWARD) |
 311 +                     (1 << NF_IP_LOCAL_OUT),
 312 +       .family     = AF_INET,
 313 +       .me         = THIS_MODULE,
 314 +};
 315 +
 316 +static int __init xt_chaos_init(void)
 317 +{
 318 +       int ret = -EINVAL;
 319 +
 320 +       xm_tcp = xt_request_find_match(AF_INET, "tcp", 0);
 321 +       if(xm_tcp == NULL) {
 322 +               printk(KERN_WARNING PFX "Error: Could not find or load "
 323 +                      "\"tcp\" match\n");
 324 +               return -EINVAL;
 325 +       }
 326 +
 327 +       xt_reject = xt_request_find_target(AF_INET, "REJECT", 0);
 328 +       if(xt_reject == NULL) {
 329 +               printk(KERN_WARNING PFX "Error: Could not find or load "
 330 +                      "\"REJECT\" target\n");
 331 +               goto out2;
 332 +       }
 333 +
 334 +       xt_tarpit   = xt_request_find_target(AF_INET, "TARPIT", 0);
 335 +       have_tarpit = xt_tarpit != NULL;
 336 +       if(!have_tarpit)
 337 +               printk(KERN_WARNING PFX "Warning: Could not find or load "
 338 +                      "\"TARPIT\" target\n");
 339 +
 340 +       xt_delude   = xt_request_find_target(AF_INET, "DELUDE", 0);
 341 +       have_delude = xt_delude != NULL;
 342 +       if(!have_delude)
 343 +               printk(KERN_WARNING PFX "Warning: Could not find or load "
 344 +                      "\"DELUDE\" target\n");
 345 +
 346 +       if((ret = xt_register_target(&xt_chaos_info)) != 0) {
 347 +               printk(KERN_WARNING PFX "xt_register_target returned "
 348 +                      "error %d\n", ret);
 349 +               goto out3;
 350 +       }
 351 +
 352 +       return 0;
 353 +
 354 + out3:
 355 +       if(have_delude)
 356 +               module_put(xt_delude->me);
 357 +       if(have_tarpit)
 358 +               module_put(xt_tarpit->me);
 359 +       module_put(xt_reject->me);
 360 + out2:
 361 +       module_put(xm_tcp->me);
 362 +       return ret;
 363 +}
 364 +
 365 +static void __exit xt_chaos_exit(void)
 366 +{
 367 +       xt_unregister_target(&xt_chaos_info);
 368 +       module_put(xm_tcp->me);
 369 +       module_put(xt_reject->me);
 370 +       if(have_delude)
 371 +               module_put(xt_delude->me);
 372 +       if(have_tarpit)
 373 +               module_put(xt_tarpit->me);
 374 +       return;
 375 +}
 376 +
 377 +module_init(xt_chaos_init);
 378 +module_exit(xt_chaos_exit);
 379 +MODULE_AUTHOR("Jan Engelhardt <jengelh@gmx.de>");
 380 +MODULE_DESCRIPTION("netfilter CHAOS target");
 381 +MODULE_LICENSE("GPL");
 382 +MODULE_ALIAS("ipt_CHAOS");
 383 Index: linux-2.6.23/net/netfilter/xt_DELUDE.c
 384 ===================================================================
 385 --- /dev/null   1970-01-01 00:00:00.000000000 +0000
 386 +++ linux-2.6.23/net/netfilter/xt_DELUDE.c      2007-10-10 13:52:59.000000000 +0800
 387 @@ -0,0 +1,288 @@
 388 +/*
 389 +       DELUDE target
 390 +       Copyright © Jan Engelhardt <jengelh [at] gmx de>, 2007
 391 +
 392 +       Based upon linux-2.6.18.5/net/ipv4/netfilter/ipt_REJECT.c:
 393 +       (C) 1999-2001 Paul `Rusty' Russell
 394 +       (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
 395 +
 396 +       xt_DELUDE acts like REJECT, but does reply with SYN-ACK on SYN.
 397 +
 398 +       This program is free software; you can redistribute it and/or modify
 399 +       it under the terms of the GNU General Public License version 2 as
 400 +       published by the Free Software Foundation.
 401 +*/
 402 +#include <linux/module.h>
 403 +#include <linux/skbuff.h>
 404 +#include <linux/ip.h>
 405 +#include <linux/random.h>
 406 +#include <linux/tcp.h>
 407 +#include <linux/udp.h>
 408 +#include <linux/icmp.h>
 409 +#include <net/icmp.h>
 410 +#include <net/ip.h>
 411 +#include <net/tcp.h>
 412 +#include <net/route.h>
 413 +#include <net/dst.h>
 414 +#include <linux/netfilter_ipv4/ip_tables.h>
 415 +#ifdef CONFIG_BRIDGE_NETFILTER
 416 +#      include <linux/netfilter_bridge.h>
 417 +#endif
 418 +#include <linux/netfilter/oot_trans.h>
 419 +#define PFX KBUILD_MODNAME ": "
 420 +
 421 +static inline struct rtable *route_reverse(struct sk_buff *skb,
 422 +                                          struct tcphdr *tcph, int hook)
 423 +{
 424 +       struct iphdr *iph = ip_hdr(skb);
 425 +       struct dst_entry *odst;
 426 +       struct flowi fl = {};
 427 +       struct rtable *rt;
 428 +
 429 +       /* We don't require ip forwarding to be enabled to be able to
 430 +        * send a RST reply for bridged traffic. */
 431 +       if (hook != NF_IP_FORWARD
 432 +#ifdef CONFIG_BRIDGE_NETFILTER
 433 +           || (skb->nf_bridge && skb->nf_bridge->mask & BRNF_BRIDGED)
 434 +#endif
 435 +          ) {
 436 +               fl.nl_u.ip4_u.daddr = iph->saddr;
 437 +               if (hook == NF_IP_LOCAL_IN)
 438 +                       fl.nl_u.ip4_u.saddr = iph->daddr;
 439 +               fl.nl_u.ip4_u.tos = RT_TOS(iph->tos);
 440 +
 441 +               if (ip_route_output_key(&rt, &fl) != 0)
 442 +                       return NULL;
 443 +       } else {
 444 +               /* non-local src, find valid iif to satisfy
 445 +                * rp-filter when calling ip_route_input. */
 446 +               fl.nl_u.ip4_u.daddr = iph->daddr;
 447 +               if (ip_route_output_key(&rt, &fl) != 0)
 448 +                       return NULL;
 449 +
 450 +               odst = skb->dst;
 451 +               if (ip_route_input(skb, iph->saddr, iph->daddr,
 452 +                                  RT_TOS(iph->tos), rt->u.dst.dev) != 0) {
 453 +                       dst_release(&rt->u.dst);
 454 +                       return NULL;
 455 +               }
 456 +               dst_release(&rt->u.dst);
 457 +               rt = (struct rtable *)skb->dst;
 458 +               skb->dst = odst;
 459 +
 460 +               fl.nl_u.ip4_u.daddr = iph->saddr;
 461 +               fl.nl_u.ip4_u.saddr = iph->daddr;
 462 +               fl.nl_u.ip4_u.tos = RT_TOS(iph->tos);
 463 +       }
 464 +
 465 +       if (rt->u.dst.error) {
 466 +               dst_release(&rt->u.dst);
 467 +               return NULL;
 468 +       }
 469 +
 470 +       fl.proto = IPPROTO_TCP;
 471 +       fl.fl_ip_sport = tcph->dest;
 472 +       fl.fl_ip_dport = tcph->source;
 473 +
 474 +       xfrm_lookup((struct dst_entry **)&rt, &fl, NULL, 0);
 475 +
 476 +       return rt;
 477 +}
 478 +
 479 +static void send_reset(struct sk_buff *oldskb, int hook)
 480 +{
 481 +       struct sk_buff *nskb;
 482 +       struct iphdr *iph = ip_hdr(oldskb);
 483 +       struct tcphdr _otcph, *oth, *tcph;
 484 +       __be16 tmp_port;
 485 +       __be32 tmp_addr;
 486 +       int needs_ack;
 487 +       unsigned int addr_type;
 488 +
 489 +       /* IP header checks: fragment. */
 490 +       if (iph->frag_off & htons(IP_OFFSET))
 491 +               return;
 492 +
 493 +       oth = skb_header_pointer(oldskb, ip_hdrlen(oldskb),
 494 +                                sizeof(_otcph), &_otcph);
 495 +       if (oth == NULL)
 496 +               return;
 497 +
 498 +       /* No RST for RST. */
 499 +       if (oth->rst)
 500 +               return;
 501 +
 502 +       /* Check checksum */
 503 +       if (nf_ip_checksum(oldskb, hook, ip_hdrlen(oldskb), IPPROTO_TCP))
 504 +               return;
 505 +
 506 +       /* We need a linear, writeable skb.  We also need to expand
 507 +          headroom in case hh_len of incoming interface < hh_len of
 508 +          outgoing interface */
 509 +       nskb = skb_copy_expand(oldskb, LL_MAX_HEADER, skb_tailroom(oldskb),
 510 +                              GFP_ATOMIC);
 511 +       if (!nskb)
 512 +               return;
 513 +
 514 +       /* This packet will not be the same as the other: clear nf fields */
 515 +       nf_reset(nskb);
 516 +       nskb->nfmark = 0;
 517 +       skb_init_secmark(nskb);
 518 +
 519 +       skb_shinfo(nskb)->gso_size = 0;
 520 +       skb_shinfo(nskb)->gso_segs = 0;
 521 +       skb_shinfo(nskb)->gso_type = 0;
 522 +
 523 +       tcph = tcp_hdr(nskb);
 524 +
 525 +       /* Swap source and dest */
 526 +       tmp_addr = ip_hdr(nskb)->saddr;
 527 +       ip_hdr(nskb)->saddr = ip_hdr(nskb)->daddr;
 528 +       ip_hdr(nskb)->daddr = tmp_addr;
 529 +       tmp_port = tcph->source;
 530 +       tcph->source = tcph->dest;
 531 +       tcph->dest = tmp_port;
 532 +
 533 +       /* Truncate to length (no data) */
 534 +       tcph->doff = sizeof(struct tcphdr)/4;
 535 +       skb_trim(nskb, ip_hdrlen(nskb) + sizeof(struct tcphdr));
 536 +       ip_hdr(nskb)->tot_len = htons(nskb->len);
 537 +
 538 +       if(oth->syn && !oth->ack && !oth->rst && !oth->fin) {
 539 +               /* DELUDE essential part */
 540 +               tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn + oth->fin +
 541 +                               oldskb->len - ip_hdrlen(oldskb) -
 542 +                               (oth->doff << 2));
 543 +               tcph->seq     = htonl(secure_tcp_sequence_number(
 544 +                               ip_hdr(nskb)->saddr, ip_hdr(nskb)->daddr,
 545 +                               tcph->source, tcph->dest));
 546 +               tcph->ack     = 1;
 547 +       } else {
 548 +               if(!tcph->ack) {
 549 +                       needs_ack = 1;
 550 +                       tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn + oth->fin
 551 +                                             + oldskb->len - ip_hdrlen(oldskb)
 552 +                                             - (oth->doff<<2));
 553 +                       tcph->seq = 0;
 554 +               } else {
 555 +                       needs_ack = 0;
 556 +                       tcph->seq = oth->ack_seq;
 557 +                       tcph->ack_seq = 0;
 558 +               }
 559 +
 560 +               /* Reset flags */
 561 +               ((u_int8_t *)tcph)[13] = 0;
 562 +               tcph->rst = 1;
 563 +               tcph->ack = needs_ack;
 564 +       }
 565 +
 566 +
 567 +       tcph->window = 0;
 568 +       tcph->urg_ptr = 0;
 569 +
 570 +       /* Adjust TCP checksum */
 571 +       tcph->check = 0;
 572 +       tcph->check = tcp_v4_check(tcph, sizeof(struct tcphdr),
 573 +                                  ip_hdr(nskb)->saddr,
 574 +                                  ip_hdr(nskb)->daddr,
 575 +                                  csum_partial((char *)tcph,
 576 +                                               sizeof(struct tcphdr), 0));
 577 +
 578 +       /* Set DF, id = 0 */
 579 +       ip_hdr(nskb)->frag_off = htons(IP_DF);
 580 +       ip_hdr(nskb)->id = 0;
 581 +
 582 +       addr_type = RTN_UNSPEC;
 583 +       if (hook != NF_IP_FORWARD
 584 +#ifdef CONFIG_BRIDGE_NETFILTER
 585 +           || (nskb->nf_bridge && nskb->nf_bridge->mask & BRNF_BRIDGED)
 586 +#endif
 587 +          )
 588 +               addr_type = RTN_LOCAL;
 589 +
 590 +       if (ip_route_me_harder(&nskb, addr_type))
 591 +               goto free_nskb;
 592 +
 593 +       nskb->ip_summed = CHECKSUM_NONE;
 594 +
 595 +       /* Adjust IP TTL */
 596 +       ip_hdr(nskb)->ttl = dst_metric(nskb->dst, RTAX_HOPLIMIT);
 597 +
 598 +       /* Adjust IP checksum */
 599 +       ip_hdr(nskb)->check = 0;
 600 +       ip_hdr(nskb)->check = ip_fast_csum((unsigned char *)ip_hdr(nskb),
 601 +                                          ip_hdr(nskb)->ihl);
 602 +
 603 +       /* "Never happens" */
 604 +       if (nskb->len > dst_mtu(nskb->dst))
 605 +               goto free_nskb;
 606 +
 607 +       nf_ct_attach(nskb, oldskb);
 608 +
 609 +       NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, nskb, NULL, nskb->dst->dev,
 610 +               dst_output);
 611 +       return;
 612 +
 613 + free_nskb:
 614 +       kfree_skb(nskb);
 615 +}
 616 +
 617 +static unsigned int xt_delude_target(struct sk_buff **pskb,
 618 +    const struct net_device *in, const struct net_device *out,
 619 +    unsigned int hooknum, const struct xt_target *target, const void *targinfo
 620 +#ifdef HAVE_TARGUSERINFO
 621 +    ,
 622 +    void *userinfo
 623 +#endif
 624 +    )
 625 +{
 626 +       /* WARNING: This code causes reentry within iptables.
 627 +          This means that the iptables jump stack is now crap.  We
 628 +          must return an absolute verdict. --RR */
 629 +       send_reset(*pskb, hooknum);
 630 +       return NF_DROP;
 631 +}
 632 +
 633 +static bool xt_delude_check(const char *tablename, const void *e_void,
 634 +    const struct xt_target *target, void *targinfo,
 635 +#ifdef HAVE_TARGINFOSIZE
 636 +    unsigned int targinfosize,
 637 +#endif
 638 +    unsigned int hook_mask)
 639 +{
 640 +       if(hook_mask & ~((1 << NF_IP_LOCAL_IN) | (1 << NF_IP_FORWARD))) {
 641 +               printk(KERN_WARNING PFX "DELUDE may not be used in chains "
 642 +                      "other than INPUT and FORWARD\n");
 643 +               return false;
 644 +       }
 645 +       return true;
 646 +}
 647 +
 648 +static struct xt_target xt_delude_info = {
 649 +       .name       = "DELUDE",
 650 +       .target     = xt_delude_target,
 651 +       .checkentry = xt_delude_check,
 652 +       .table      = "filter",
 653 +       .hooks      = (1 << NF_IP_LOCAL_IN) | (1 << NF_IP_FORWARD) |
 654 +                     (1 << NF_IP_LOCAL_OUT),
 655 +       .proto      = IPPROTO_TCP,
 656 +       .family     = AF_INET,
 657 +       .me         = THIS_MODULE,
 658 +};
 659 +
 660 +static int __init xt_delude_init(void)
 661 +{
 662 +       return xt_register_target(&xt_delude_info);
 663 +}
 664 +
 665 +static void __exit xt_delude_exit(void)
 666 +{
 667 +       xt_unregister_target(&xt_delude_info);
 668 +}
 669 +
 670 +module_init(xt_delude_init);
 671 +module_exit(xt_delude_exit);
 672 +MODULE_AUTHOR("Jan Engelhardt <jengelh@gmx.de>");
 673 +MODULE_DESCRIPTION("netfilter DELUDE target");
 674 +MODULE_LICENSE("GPL");
 675 +MODULE_ALIAS("ipt_DELUDE");
 676 Index: linux-2.6.23/net/netfilter/xt_portscan.c
 677 ===================================================================
 678 --- /dev/null   1970-01-01 00:00:00.000000000 +0000
 679 +++ linux-2.6.23/net/netfilter/xt_portscan.c    2007-10-10 13:52:59.000000000 +0800
 680 @@ -0,0 +1,272 @@
 681 +/*
 682 +       portscan match for netfilter
 683 +
 684 +       Written by Jan Engelhardt, 2006 - 2007
 685 +       This program is free software; you can redistribute it and/or modify
 686 +       it under the terms of the GNU General Public License version 2 as
 687 +       published by the Free Software Foundation.
 688 +*/
 689 +#include <linux/in.h>
 690 +#include <linux/ip.h>
 691 +#include <linux/module.h>
 692 +#include <linux/moduleparam.h>
 693 +#include <linux/skbuff.h>
 694 +#include <linux/stat.h>
 695 +#include <linux/tcp.h>
 696 +#include <linux/types.h>
 697 +#include <linux/version.h>
 698 +#include <linux/netfilter/x_tables.h>
 699 +#include <linux/netfilter/xt_tcpudp.h>
 700 +#include <linux/netfilter/oot_conntrack.h>
 701 +#include <linux/netfilter/xt_portscan.h>
 702 +#include <linux/netfilter/oot_trans.h>
 703 +#define PFX KBUILD_MODNAME ": "
 704 +
 705 +enum {
 706 +       TCP_FLAGS_ALL3 = TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_SYN,
 707 +       TCP_FLAGS_ALL4 = TCP_FLAGS_ALL3 | TCP_FLAG_ACK,
 708 +       TCP_FLAGS_ALL6 = TCP_FLAGS_ALL4 | TCP_FLAG_PSH | TCP_FLAG_URG,
 709 +};
 710 +
 711 +/* Module parameters */
 712 +static unsigned int
 713 +       connmark_mask = ~0,
 714 +       packet_mask   = ~0,
 715 +       mark_seen     = 0x9,
 716 +       mark_synrcv   = 0x1,
 717 +       mark_closed   = 0x2,
 718 +       mark_synscan  = 0x3,
 719 +       mark_estab1   = 0x4,
 720 +       mark_estab2   = 0x5,
 721 +       mark_cnscan   = 0x6,
 722 +       mark_grscan   = 0x7,
 723 +       mark_valid    = 0x8;
 724 +
 725 +module_param(connmark_mask, uint, S_IRUGO | S_IWUSR);
 726 +module_param(packet_mask,   uint, S_IRUGO | S_IWUSR);
 727 +module_param(mark_seen,     uint, S_IRUGO | S_IWUSR);
 728 +module_param(mark_synrcv,   uint, S_IRUGO | S_IWUSR);
 729 +module_param(mark_closed,   uint, S_IRUGO | S_IWUSR);
 730 +module_param(mark_synscan,  uint, S_IRUGO | S_IWUSR);
 731 +module_param(mark_estab1,   uint, S_IRUGO | S_IWUSR);
 732 +module_param(mark_estab2,   uint, S_IRUGO | S_IWUSR);
 733 +module_param(mark_cnscan,   uint, S_IRUGO | S_IWUSR);
 734 +module_param(mark_grscan,   uint, S_IRUGO | S_IWUSR);
 735 +module_param(mark_valid,    uint, S_IRUGO | S_IWUSR);
 736 +MODULE_PARM_DESC(connmark_mask, "only set specified bits in connection mark");
 737 +MODULE_PARM_DESC(packet_mask,   "only set specified bits in packet mark");
 738 +MODULE_PARM_DESC(mark_seen,     "nfmark value for packet-seen state");
 739 +MODULE_PARM_DESC(mark_synrcv,   "connmark value for SYN Received state");
 740 +MODULE_PARM_DESC(mark_closed,   "connmark value for closed state");
 741 +MODULE_PARM_DESC(mark_synscan,  "connmark value for SYN Scan state");
 742 +MODULE_PARM_DESC(mark_estab1,   "connmark value for Established-1 state");
 743 +MODULE_PARM_DESC(mark_estab2,   "connmark value for Established-2 state");
 744 +MODULE_PARM_DESC(mark_cnscan,   "connmark value for Connect Scan state");
 745 +MODULE_PARM_DESC(mark_grscan,   "connmark value for Grab Scan state");
 746 +MODULE_PARM_DESC(mark_valid,    "connmark value for Valid state");
 747 +
 748 +/* TCP flag functions */
 749 +static inline int tflg_ack4(const struct tcphdr *th)
 750 +{
 751 +       return (tcp_flag_word(th) & TCP_FLAGS_ALL4) == TCP_FLAG_ACK;
 752 +}
 753 +
 754 +static inline int tflg_ack6(const struct tcphdr *th)
 755 +{
 756 +       return (tcp_flag_word(th) & TCP_FLAGS_ALL6) == TCP_FLAG_ACK;
 757 +}
 758 +
 759 +static inline int tflg_fin(const struct tcphdr *th)
 760 +{
 761 +       return (tcp_flag_word(th) & TCP_FLAGS_ALL3) == TCP_FLAG_FIN;
 762 +}
 763 +
 764 +static inline int tflg_rst(const struct tcphdr *th)
 765 +{
 766 +       return (tcp_flag_word(th) & TCP_FLAGS_ALL3) == TCP_FLAG_RST;
 767 +}
 768 +
 769 +static inline int tflg_rstack(const struct tcphdr *th)
 770 +{
 771 +       return (tcp_flag_word(th) & TCP_FLAGS_ALL4) ==
 772 +              (TCP_FLAG_ACK | TCP_FLAG_RST);
 773 +}
 774 +
 775 +static inline int tflg_syn(const struct tcphdr *th)
 776 +{
 777 +       return (tcp_flag_word(th) & TCP_FLAGS_ALL4) == TCP_FLAG_SYN;
 778 +}
 779 +
 780 +static inline int tflg_synack(const struct tcphdr *th)
 781 +{
 782 +       return (tcp_flag_word(th) & TCP_FLAGS_ALL4) ==
 783 +              (TCP_FLAG_SYN | TCP_FLAG_ACK);
 784 +}
 785 +
 786 +/* portscan functions */
 787 +static inline int xt_portscan_stealth(const struct tcphdr *th)
 788 +{
 789 +       /*
 790 +        * "Connection refused" replies to our own probes must not be matched.
 791 +        */
 792 +       if(tflg_rstack(th))
 793 +               return 0;
 794 +
 795 +       if(tflg_rst(th) && printk_ratelimit()) {
 796 +               printk(KERN_WARNING PFX "Warning: Pure RST received\n");
 797 +               return 0;
 798 +       }
 799 +
 800 +       /*
 801 +        * -p tcp ! --syn -m conntrack --ctstate INVALID: Looking for non-start
 802 +        * packets that are not associated with any connection -- this will
 803 +        * match most scan types (NULL, XMAS, FIN) and ridiculous flag
 804 +        * combinations (SYN-RST, SYN-FIN, SYN-FIN-RST, FIN-RST, etc.).
 805 +        */
 806 +       return !tflg_syn(th);
 807 +}
 808 +
 809 +static inline int xt_portscan_full(int mark, enum ip_conntrack_info ctstate,
 810 +    int loopback, const struct tcphdr *tcph, int payload_len)
 811 +{
 812 +       if(mark == mark_estab2) {
 813 +               /*
 814 +                * -m connmark --mark $ESTAB2
 815 +                */
 816 +               if(tflg_ack4(tcph) && payload_len == 0)
 817 +                       return mark; /* keep mark */
 818 +               else if(tflg_rst(tcph) || tflg_fin(tcph))
 819 +                       return mark_grscan;
 820 +               else
 821 +                       return mark_valid;
 822 +       } else if(mark == mark_estab1) {
 823 +               /*
 824 +                * -m connmark --mark $ESTAB1
 825 +                */
 826 +               if(tflg_rst(tcph) || tflg_fin(tcph))
 827 +                       return mark_cnscan;
 828 +               else if(!loopback && tflg_ack4(tcph) && payload_len == 0)
 829 +                       return mark_estab2;
 830 +               else
 831 +                       return mark_valid;
 832 +       } else if(mark == mark_synrcv) {
 833 +               /*
 834 +                * -m connmark --mark $SYN
 835 +                */
 836 +               if(loopback && tflg_synack(tcph))
 837 +                       return mark; /* keep mark */
 838 +               else if(loopback && tflg_rstack(tcph))
 839 +                       return mark_closed;
 840 +               else if(tflg_ack6(tcph))
 841 +                       return mark_estab1;
 842 +               else
 843 +                       return mark_synscan;
 844 +       } else if(ctstate == IP_CT_NEW && tflg_syn(tcph)) {
 845 +               /*
 846 +                * -p tcp --syn --ctstate NEW
 847 +                */
 848 +               return mark_synrcv;
 849 +       }
 850 +       return mark;
 851 +}
 852 +
 853 +static bool xt_portscan_match(const struct sk_buff *skb,
 854 +    const struct net_device *in, const struct net_device *out,
 855 +    const struct xt_match *match, const void *matchinfo, int offset,
 856 +    unsigned int protoff, bool *hotdrop)
 857 +{
 858 +       const struct xt_portscan_info *info = matchinfo;
 859 +       enum ip_conntrack_info ctstate;
 860 +       struct nf_conn *ctdata;
 861 +       const struct tcphdr *tcph;
 862 +       struct tcphdr tcph_buf;
 863 +
 864 +       tcph = skb_header_pointer(skb, protoff, sizeof(tcph_buf), &tcph_buf);
 865 +       if(tcph == NULL)
 866 +               return false;
 867 +
 868 +       /* Check for invalid packets: -m conntrack --ctstate INVALID */
 869 +       if((ctdata = nf_ct_get(skb, &ctstate)) == NULL) {
 870 +               if(info->match_stealth)
 871 +                       return xt_portscan_stealth(tcph);
 872 +               /*
 873 +                * If @ctdata is NULL, we cannot match the other scan
 874 +                * types, return.
 875 +                */
 876 +               return false;
 877 +       }
 878 +
 879 +       /*
 880 +        * If -m portscan was previously applied to this packet, the rules we
 881 +        * simulate must not be run through again. And for speedup, do not call
 882 +        * it either when the connection is already VALID.
 883 +        */
 884 +       if((ctdata->mark & connmark_mask) == mark_valid ||
 885 +         (skb->nfmark & packet_mask) != mark_seen)
 886 +       {
 887 +               unsigned int n;
 888 +               n = xt_portscan_full(ctdata->mark & connmark_mask, ctstate,
 889 +                   in == &loopback_dev, tcph,
 890 +                   skb->len - protoff - 4 * tcph->doff);
 891 +
 892 +               ctdata->mark = (ctdata->mark & ~connmark_mask) | n;
 893 +               ((struct sk_buff *)skb)->nfmark =
 894 +                       (skb->nfmark & ~packet_mask) | mark_seen;
 895 +       }
 896 +
 897 +       return (info->match_syn && ctdata->mark == mark_synscan) ||
 898 +              (info->match_cn && ctdata->mark == mark_cnscan) ||
 899 +              (info->match_gr && ctdata->mark == mark_grscan);
 900 +}
 901 +
 902 +static bool xt_portscan_checkentry(const char *tablename, const void *entry,
 903 +    const struct xt_match *match, void *matchinfo,
 904 +#ifdef HAVE_MATCHINFOSIZE
 905 +    unsigned int matchinfosize,
 906 +#endif
 907 +    unsigned int hook_mask)
 908 +{
 909 +       const struct xt_portscan_info *info = matchinfo;
 910 +#ifdef HAVE_MATCHINFOSIZE
 911 +       if(matchinfosize != XT_ALIGN(sizeof(struct xt_portscan_info))) {
 912 +               printk(KERN_WARNING PFX "matchinfosize %u != %Zu\n",
 913 +                      matchinfosize,
 914 +                      XT_ALIGN(sizeof(struct xt_portscan_info)));
 915 +               return false;
 916 +       }
 917 +#endif
 918 +       if((info->match_stealth & ~1) || (info->match_syn & ~1) ||
 919 +         (info->match_cn & ~1) || (info->match_gr & ~1)) {
 920 +               printk(KERN_WARNING PFX "Invalid flags\n");
 921 +               return false;
 922 +       }
 923 +       return true;
 924 +}
 925 +
 926 +static struct xt_match xt_portscan = {
 927 +       .name       = "portscan",
 928 +       .match      = xt_portscan_match,
 929 +       .checkentry = xt_portscan_checkentry,
 930 +       .matchsize  = sizeof(struct xt_portscan_info),
 931 +       .proto      = IPPROTO_TCP,
 932 +       .family     = AF_INET,
 933 +       .me         = THIS_MODULE,
 934 +};
 935 +
 936 +static int __init xt_portscan_init(void)
 937 +{
 938 +       return xt_register_match(&xt_portscan);
 939 +}
 940 +
 941 +static void __exit xt_portscan_exit(void)
 942 +{
 943 +       xt_unregister_match(&xt_portscan);
 944 +       return;
 945 +}
 946 +
 947 +module_init(xt_portscan_init);
 948 +module_exit(xt_portscan_exit);
 949 +MODULE_AUTHOR("Jan Engelhardt <jengelh@gmx.de>");
 950 +MODULE_DESCRIPTION("netfilter portscan match module");
 951 +MODULE_LICENSE("GPL");
 952 +MODULE_ALIAS("ipt_portscan");
 953 Index: linux-2.6.23/drivers/char/random.c
 954 ===================================================================
 955 --- linux-2.6.23.orig/drivers/char/random.c     2007-10-10 04:31:38.000000000 +0800
 956 +++ linux-2.6.23/drivers/char/random.c  2007-10-10 13:52:59.000000000 +0800
 957 @@ -1564,6 +1564,8 @@
 958         return seq;
 959  }
 960
 961 +EXPORT_SYMBOL(secure_tcp_sequence_number);
 962 +
 963  /* Generate secure starting point for ephemeral IPV4 transport port search */
 964  u32 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport)
 965  {