target/linux/generic-2.6/patches-2.6.27/170-netfilter_chaostables_0.8.patch

   1 --- /dev/null
   2 +++ b/include/linux/netfilter/oot_conntrack.h
   3 @@ -0,0 +1,5 @@
   4 +#if defined(CONFIG_IP_NF_CONNTRACK) || defined(CONFIG_IP_NF_CONNTRACK_MODULE)
   5 +#      include <linux/netfilter_ipv4/ip_conntrack.h>
   6 +#else /* linux-2.6.20+ */
   7 +#      include <net/netfilter/nf_nat_rule.h>
   8 +#endif
   9 --- /dev/null
  10 +++ b/include/linux/netfilter/oot_trans.h
  11 @@ -0,0 +1,14 @@
  12 +/* Out of tree workarounds */
  13 +#include <linux/version.h>
  14 +#if LINUX_VERSION_CODE <= KERNEL_VERSION(2, 6, 18)
  15 +#      define HAVE_MATCHINFOSIZE 1
  16 +#      define HAVE_TARGUSERINFO 1
  17 +#      define HAVE_TARGINFOSIZE 1
  18 +#endif
  19 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 20)
  20 +#      define nfmark mark
  21 +#endif
  22 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 21)
  23 +#      define tcp_v4_check(tcph, tcph_sz, s, d, csp) \
  24 +               tcp_v4_check((tcph_sz), (s), (d), (csp))
  25 +#endif
  26 --- /dev/null
  27 +++ b/include/linux/netfilter/xt_CHAOS.h
  28 @@ -0,0 +1,14 @@
  29 +#ifndef _LINUX_NETFILTER_XT_CHAOS_H
  30 +#define _LINUX_NETFILTER_XT_CHAOS_H 1
  31 +
  32 +enum xt_chaos_target_variant {
  33 +       XTCHAOS_NORMAL,
  34 +       XTCHAOS_TARPIT,
  35 +       XTCHAOS_DELUDE,
  36 +};
  37 +
  38 +struct xt_chaos_target_info {
  39 +       uint8_t variant;
  40 +};
  41 +
  42 +#endif /* _LINUX_NETFILTER_XT_CHAOS_H */
  43 --- /dev/null
  44 +++ b/include/linux/netfilter/xt_portscan.h
  45 @@ -0,0 +1,8 @@
  46 +#ifndef _LINUX_NETFILTER_XT_PORTSCAN_H
  47 +#define _LINUX_NETFILTER_XT_PORTSCAN_H 1
  48 +
  49 +struct xt_portscan_match_info {
  50 +       uint8_t match_stealth, match_syn, match_cn, match_gr;
  51 +};
  52 +
  53 +#endif /* _LINUX_NETFILTER_XT_PORTSCAN_H */
  54 --- /dev/null
  55 +++ b/net/netfilter/find_match.c
  56 @@ -0,0 +1,39 @@
  57 +/*
  58 +    xt_request_find_match
  59 +    by Jan Engelhardt <jengelh [at] gmx de>, 2006 - 2007
  60 +
  61 +    Based upon linux-2.6.18.5/net/netfilter/x_tables.c:
  62 +    Copyright (C) 2006-2006 Harald Welte <laforge@netfilter.org>
  63 +    This program is free software; you can redistribute it and/or modify
  64 +    it under the terms of the GNU General Public License version 2 as
  65 +    published by the Free Software Foundation.
  66 +*/
  67 +#include <linux/err.h>
  68 +#include <linux/netfilter_arp.h>
  69 +#include <linux/socket.h>
  70 +#include <linux/netfilter/x_tables.h>
  71 +
  72 +/*
  73 + * Yeah this code is sub-optimal, but the function is missing in
  74 + * mainline so far. -jengelh
  75 + */
  76 +static struct xt_match *xt_request_find_match_lo(int af, const char *name,
  77 +    u8 revision)
  78 +{
  79 +       static const char *const xt_prefix[] = {
  80 +               [AF_INET]  = "ip",
  81 +               [AF_INET6] = "ip6",
  82 +               [NF_ARP]   = "arp",
  83 +       };
  84 +       struct xt_match *match;
  85 +
  86 +       match = try_then_request_module(xt_find_match(af, name, revision),
  87 +               "%st_%s", xt_prefix[af], name);
  88 +       if (IS_ERR(match) || match == NULL)
  89 +               return NULL;
  90 +
  91 +       return match;
  92 +}
  93 +
  94 +/* In case it goes into mainline, let this out-of-tree package compile */
  95 +#define xt_request_find_match xt_request_find_match_lo
  96 --- a/net/netfilter/Kconfig
  97 +++ b/net/netfilter/Kconfig
  98 @@ -296,6 +296,14 @@ config NETFILTER_XTABLES
  99
 100  # alphabetically ordered list of targets
 101
 102 +config NETFILTER_XT_TARGET_CHAOS
 103 +       tristate '"CHAOS" target support'
 104 +       depends on NETFILTER_XTABLES
 105 +       help
 106 +         This option adds a `CHAOS' target.
 107 +
 108 +         To compile it as a module, choose M here.  If unsure, say N.
 109 +
 110  config NETFILTER_XT_TARGET_CLASSIFY
 111         tristate '"CLASSIFY" target support'
 112         depends on NETFILTER_XTABLES
 113 @@ -325,6 +333,14 @@ config NETFILTER_XT_TARGET_CONNMARK
 114           <file:Documentation/kbuild/modules.txt>.  The module will be called
 115           ipt_CONNMARK.ko.  If unsure, say `N'.
 116
 117 +config NETFILTER_XT_TARGET_DELUDE
 118 +       tristate '"DELUDE" target support'
 119 +       depends on NETFILTER_XTABLES
 120 +       help
 121 +         This option adds a `DELUDE' target.
 122 +
 123 +         To compile it as a module, choose M here.  If unsure, say N.
 124 +
 125  config NETFILTER_XT_TARGET_DSCP
 126         tristate '"DSCP" and "TOS" target support'
 127         depends on NETFILTER_XTABLES
 128 @@ -661,6 +677,14 @@ config NETFILTER_XT_MATCH_POLICY
 129
 130           To compile it as a module, choose M here.  If unsure, say N.
 131
 132 +config NETFILTER_XT_MATCH_PORTSCAN
 133 +       tristate '"portscan" match support'
 134 +       depends on NETFILTER_XTABLES
 135 +       help
 136 +         This option adds a 'portscan' match support.
 137 +
 138 +         To compile it as a module, choose M here.  If unsure, say N.
 139 +
 140  config NETFILTER_XT_MATCH_MULTIPORT
 141         tristate '"multiport" Multiple port match support'
 142         depends on NETFILTER_XTABLES
 143 --- a/net/netfilter/Makefile
 144 +++ b/net/netfilter/Makefile
 145 @@ -51,6 +51,8 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_SECMARK
 146  obj-$(CONFIG_NETFILTER_XT_TARGET_TCPMSS) += xt_TCPMSS.o
 147  obj-$(CONFIG_NETFILTER_XT_TARGET_TCPOPTSTRIP) += xt_TCPOPTSTRIP.o
 148  obj-$(CONFIG_NETFILTER_XT_TARGET_TRACE) += xt_TRACE.o
 149 +obj-$(CONFIG_NETFILTER_XT_TARGET_CHAOS) += xt_CHAOS.o
 150 +obj-$(CONFIG_NETFILTER_XT_TARGET_DELUDE) += xt_DELUDE.o
 151
 152  # matches
 153  obj-$(CONFIG_NETFILTER_XT_MATCH_COMMENT) += xt_comment.o
 154 @@ -84,3 +86,4 @@ obj-$(CONFIG_NETFILTER_XT_MATCH_STRING)
 155  obj-$(CONFIG_NETFILTER_XT_MATCH_TCPMSS) += xt_tcpmss.o
 156  obj-$(CONFIG_NETFILTER_XT_MATCH_TIME) += xt_time.o
 157  obj-$(CONFIG_NETFILTER_XT_MATCH_U32) += xt_u32.o
 158 +obj-$(CONFIG_NETFILTER_XT_MATCH_PORTSCAN) += xt_portscan.o
 159 --- /dev/null
 160 +++ b/net/netfilter/xt_CHAOS.c
 161 @@ -0,0 +1,200 @@
 162 +/*
 163 + *     CHAOS target for netfilter
 164 + *     Copyright © CC Computer Consultants GmbH, 2006 - 2007
 165 + *     Contact: Jan Engelhardt <jengelh@computergmbh.de>
 166 + *
 167 + *     This program is free software; you can redistribute it and/or modify
 168 + *     it under the terms of the GNU General Public License; either version
 169 + *     2 or 3 as published by the Free Software Foundation.
 170 + */
 171 +#include <linux/icmp.h>
 172 +#include <linux/in.h>
 173 +#include <linux/ip.h>
 174 +#include <linux/module.h>
 175 +#include <linux/skbuff.h>
 176 +#include <linux/stat.h>
 177 +#include <linux/netfilter/x_tables.h>
 178 +#include <linux/netfilter/xt_tcpudp.h>
 179 +#include <linux/netfilter_ipv4/ipt_REJECT.h>
 180 +#include <net/ip.h>
 181 +#if defined(_LOCAL)
 182 +#      include "xt_CHAOS.h"
 183 +#      include "find_match.c"
 184 +#elif defined(CONFIG_NETFILTER_XT_TARGET_CHAOS) || \
 185 +    defined(CONFIG_NETFILTER_XT_TARGET_CHAOS_MODULE)
 186 +#      include <linux/netfilter/xt_CHAOS.h>
 187 +#      include "find_match.c"
 188 +#else
 189 +#      include "xt_CHAOS.h"
 190 +#      include "find_match.c"
 191 +#endif
 192 +#define PFX KBUILD_MODNAME ": "
 193 +
 194 +/* Module parameters */
 195 +static unsigned int reject_percentage = ~0U * .01;
 196 +static unsigned int delude_percentage = ~0U * .0101;
 197 +module_param(reject_percentage, uint, S_IRUGO | S_IWUSR);
 198 +module_param(delude_percentage, uint, S_IRUGO | S_IWUSR);
 199 +
 200 +/* References to other matches/targets */
 201 +static struct xt_match *xm_tcp;
 202 +static struct xt_target *xt_delude, *xt_reject, *xt_tarpit;
 203 +
 204 +static int have_delude, have_tarpit;
 205 +
 206 +/* Static data for other matches/targets */
 207 +static const struct ipt_reject_info reject_params = {
 208 +       .with = ICMP_HOST_UNREACH,
 209 +};
 210 +
 211 +static const struct xt_tcp tcp_params = {
 212 +       .spts = {0, ~0},
 213 +       .dpts = {0, ~0},
 214 +};
 215 +
 216 +/* CHAOS functions */
 217 +static void xt_chaos_total(const struct xt_chaos_target_info *info,
 218 +    struct sk_buff *skb, const struct net_device *in,
 219 +    const struct net_device *out, unsigned int hooknum)
 220 +{
 221 +       const struct iphdr *iph = ip_hdr(skb);
 222 +       const int protoff       = 4 * iph->ihl;
 223 +       const int offset        = ntohs(iph->frag_off) & IP_OFFSET;
 224 +       const struct xt_target *destiny;
 225 +       bool hotdrop = false, ret;
 226 +
 227 +       ret = xm_tcp->match(skb, in, out, xm_tcp, &tcp_params,
 228 +                           offset, protoff, &hotdrop);
 229 +       if (!ret || hotdrop || (unsigned int)net_random() > delude_percentage)
 230 +               return;
 231 +
 232 +       destiny = (info->variant == XTCHAOS_TARPIT) ? xt_tarpit : xt_delude;
 233 +       destiny->target(skb, in, out, hooknum, destiny, NULL);
 234 +       return;
 235 +}
 236 +
 237 +static unsigned int chaos_tg(struct sk_buff *skb,
 238 +    const struct net_device *in, const struct net_device *out,
 239 +    unsigned int hooknum, const struct xt_target *target, const void *targinfo)
 240 +{
 241 +       /*
 242 +        * Equivalent to:
 243 +        * -A chaos -m statistic --mode random --probability \
 244 +        *         $reject_percentage -j REJECT --reject-with host-unreach;
 245 +        * -A chaos -p tcp -m statistic --mode random --probability \
 246 +        *         $delude_percentage -j DELUDE;
 247 +        * -A chaos -j DROP;
 248 +        */
 249 +       const struct xt_chaos_target_info *info = targinfo;
 250 +       const struct iphdr *iph = ip_hdr(skb);
 251 +
 252 +       if ((unsigned int)net_random() <= reject_percentage)
 253 +               return xt_reject->target(skb, in, out, hooknum, target,
 254 +                      &reject_params);
 255 +
 256 +       /* TARPIT/DELUDE may not be called from the OUTPUT chain */
 257 +       if (iph->protocol == IPPROTO_TCP &&
 258 +           info->variant != XTCHAOS_NORMAL && hooknum != NF_INET_LOCAL_OUT)
 259 +               xt_chaos_total(info, skb, in, out, hooknum);
 260 +
 261 +       return NF_DROP;
 262 +}
 263 +
 264 +static bool chaos_tg_check(const char *tablename, const void *entry,
 265 +    const struct xt_target *target, void *targinfo, unsigned int hook_mask)
 266 +{
 267 +       const struct xt_chaos_target_info *info = targinfo;
 268 +
 269 +       if (info->variant == XTCHAOS_DELUDE && !have_delude) {
 270 +               printk(KERN_WARNING PFX "Error: Cannot use --delude when "
 271 +                      "DELUDE module not available\n");
 272 +               return false;
 273 +       }
 274 +       if (info->variant == XTCHAOS_TARPIT && !have_tarpit) {
 275 +               printk(KERN_WARNING PFX "Error: Cannot use --tarpit when "
 276 +                      "TARPIT module not available\n");
 277 +               return false;
 278 +       }
 279 +
 280 +       return true;
 281 +}
 282 +
 283 +static struct xt_target chaos_tg_reg = {
 284 +       .name       = "CHAOS",
 285 +       .family     = AF_INET,
 286 +       .table      = "filter",
 287 +       .hooks      = (1 << NF_INET_LOCAL_IN) | (1 << NF_INET_FORWARD) |
 288 +                     (1 << NF_INET_LOCAL_OUT),
 289 +       .checkentry = chaos_tg_check,
 290 +       .target     = chaos_tg,
 291 +       .targetsize = sizeof(struct xt_chaos_target_info),
 292 +       .me         = THIS_MODULE,
 293 +};
 294 +
 295 +static int __init chaos_tg_init(void)
 296 +{
 297 +       int ret = -EINVAL;
 298 +
 299 +       xm_tcp = xt_request_find_match(AF_INET, "tcp", 0);
 300 +       if (xm_tcp == NULL) {
 301 +               printk(KERN_WARNING PFX "Error: Could not find or load "
 302 +                      "\"tcp\" match\n");
 303 +               return -EINVAL;
 304 +       }
 305 +
 306 +       xt_reject = xt_request_find_target(AF_INET, "REJECT", 0);
 307 +       if (xt_reject == NULL) {
 308 +               printk(KERN_WARNING PFX "Error: Could not find or load "
 309 +                      "\"REJECT\" target\n");
 310 +               goto out2;
 311 +       }
 312 +
 313 +       xt_tarpit   = xt_request_find_target(AF_INET, "TARPIT", 0);
 314 +       have_tarpit = xt_tarpit != NULL;
 315 +       if (!have_tarpit)
 316 +               printk(KERN_WARNING PFX "Warning: Could not find or load "
 317 +                      "\"TARPIT\" target\n");
 318 +
 319 +       xt_delude   = xt_request_find_target(AF_INET, "DELUDE", 0);
 320 +       have_delude = xt_delude != NULL;
 321 +       if (!have_delude)
 322 +               printk(KERN_WARNING PFX "Warning: Could not find or load "
 323 +                      "\"DELUDE\" target\n");
 324 +
 325 +       if ((ret = xt_register_target(&chaos_tg_reg)) != 0) {
 326 +               printk(KERN_WARNING PFX "xt_register_target returned "
 327 +                      "error %d\n", ret);
 328 +               goto out3;
 329 +       }
 330 +
 331 +       return 0;
 332 +
 333 + out3:
 334 +       if (have_delude)
 335 +               module_put(xt_delude->me);
 336 +       if (have_tarpit)
 337 +               module_put(xt_tarpit->me);
 338 +       module_put(xt_reject->me);
 339 + out2:
 340 +       module_put(xm_tcp->me);
 341 +       return ret;
 342 +}
 343 +
 344 +static void __exit chaos_tg_exit(void)
 345 +{
 346 +       xt_unregister_target(&chaos_tg_reg);
 347 +       module_put(xm_tcp->me);
 348 +       module_put(xt_reject->me);
 349 +       if (have_delude)
 350 +               module_put(xt_delude->me);
 351 +       if (have_tarpit)
 352 +               module_put(xt_tarpit->me);
 353 +       return;
 354 +}
 355 +
 356 +module_init(chaos_tg_init);
 357 +module_exit(chaos_tg_exit);
 358 +MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
 359 +MODULE_DESCRIPTION("netfilter \"CHAOS\" target");
 360 +MODULE_LICENSE("GPL");
 361 +MODULE_ALIAS("ipt_CHAOS");
 362 --- /dev/null
 363 +++ b/net/netfilter/xt_DELUDE.c
 364 @@ -0,0 +1,197 @@
 365 +/*
 366 + *     DELUDE target
 367 + *     Copyright © CC Computer Consultants GmbH, 2007
 368 + *     Contact: Jan Engelhardt <jengelh@computergmbh.de>
 369 + *
 370 + *     Based upon linux-2.6.18.5/net/ipv4/netfilter/ipt_REJECT.c:
 371 + *     (C) 1999-2001 Paul `Rusty' Russell
 372 + *     (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
 373 + *
 374 + *     xt_DELUDE acts like REJECT, but does reply with SYN-ACK on SYN.
 375 + *
 376 + *     This program is free software; you can redistribute it and/or modify
 377 + *     it under the terms of the GNU General Public License version 2 as
 378 + *     published by the Free Software Foundation.
 379 + */
 380 +#include <linux/module.h>
 381 +#include <linux/skbuff.h>
 382 +#include <linux/ip.h>
 383 +#include <linux/tcp.h>
 384 +#include <linux/netfilter/x_tables.h>
 385 +#ifdef CONFIG_BRIDGE_NETFILTER
 386 +#      include <linux/netfilter_bridge.h>
 387 +#endif
 388 +#include <net/tcp.h>
 389 +#define PFX KBUILD_MODNAME ": "
 390 +
 391 +static void delude_send_reset(struct sk_buff *oldskb, unsigned int hook)
 392 +{
 393 +       struct tcphdr _otcph, *oth, *tcph;
 394 +       unsigned int addr_type;
 395 +       struct sk_buff *nskb;
 396 +       u_int16_t tmp_port;
 397 +       u_int32_t tmp_addr;
 398 +       struct iphdr *niph;
 399 +       bool needs_ack;
 400 +
 401 +       /* IP header checks: fragment. */
 402 +       if (ip_hdr(oldskb)->frag_off & htons(IP_OFFSET))
 403 +               return;
 404 +
 405 +       oth = skb_header_pointer(oldskb, ip_hdrlen(oldskb),
 406 +                                sizeof(_otcph), &_otcph);
 407 +       if (oth == NULL)
 408 +               return;
 409 +
 410 +       /* No RST for RST. */
 411 +       if (oth->rst)
 412 +               return;
 413 +
 414 +       /* Check checksum */
 415 +       if (nf_ip_checksum(oldskb, hook, ip_hdrlen(oldskb), IPPROTO_TCP))
 416 +               return;
 417 +
 418 +       /* We need a linear, writeable skb.  We also need to expand
 419 +          headroom in case hh_len of incoming interface < hh_len of
 420 +          outgoing interface */
 421 +       nskb = skb_copy_expand(oldskb, LL_MAX_HEADER, skb_tailroom(oldskb),
 422 +                              GFP_ATOMIC);
 423 +       if (!nskb)
 424 +               return;
 425 +
 426 +       /* This packet will not be the same as the other: clear nf fields */
 427 +       nf_reset(nskb);
 428 +       nskb->mark = 0;
 429 +       skb_init_secmark(nskb);
 430 +
 431 +       skb_shinfo(nskb)->gso_size = 0;
 432 +       skb_shinfo(nskb)->gso_segs = 0;
 433 +       skb_shinfo(nskb)->gso_type = 0;
 434 +
 435 +       tcph = (struct tcphdr *)(skb_network_header(nskb) + ip_hdrlen(nskb));
 436 +
 437 +       /* Swap source and dest */
 438 +       niph         = ip_hdr(nskb);
 439 +       tmp_addr     = niph->saddr;
 440 +       niph->saddr  = niph->daddr;
 441 +       niph->daddr  = tmp_addr;
 442 +       tmp_port     = tcph->source;
 443 +       tcph->source = tcph->dest;
 444 +       tcph->dest   = tmp_port;
 445 +
 446 +       /* Truncate to length (no data) */
 447 +       tcph->doff    = sizeof(struct tcphdr) / 4;
 448 +       skb_trim(nskb, ip_hdrlen(nskb) + sizeof(struct tcphdr));
 449 +       niph->tot_len = htons(nskb->len);
 450 +
 451 +       if (oth->syn && !oth->ack && !oth->rst && !oth->fin) {
 452 +               /* DELUDE essential part */
 453 +               tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn + oth->fin +
 454 +                               oldskb->len - ip_hdrlen(oldskb) -
 455 +                               (oth->doff << 2));
 456 +               tcph->seq     = false;
 457 +               tcph->ack     = true;
 458 +       } else {
 459 +               if (!tcph->ack) {
 460 +                       needs_ack     = true;
 461 +                       tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn +
 462 +                                       oth->fin + oldskb->len -
 463 +                                       ip_hdrlen(oldskb) - (oth->doff<<2));
 464 +                       tcph->seq     = false;
 465 +               } else {
 466 +                       needs_ack     = false;
 467 +                       tcph->seq     = oth->ack_seq;
 468 +                       tcph->ack_seq = false;
 469 +               }
 470 +
 471 +               /* Reset flags */
 472 +               ((u_int8_t *)tcph)[13] = 0;
 473 +               tcph->rst = true;
 474 +               tcph->ack = needs_ack;
 475 +       }
 476 +
 477 +       tcph->window  = 0;
 478 +       tcph->urg_ptr = 0;
 479 +
 480 +       /* Adjust TCP checksum */
 481 +       tcph->check = 0;
 482 +       tcph->check = tcp_v4_check(sizeof(struct tcphdr), niph->saddr,
 483 +                     niph->daddr, csum_partial((char *)tcph,
 484 +                     sizeof(struct tcphdr), 0));
 485 +
 486 +       /* Set DF, id = 0 */
 487 +       niph->frag_off = htons(IP_DF);
 488 +       niph->id       = 0;
 489 +
 490 +       addr_type = RTN_UNSPEC;
 491 +#ifdef CONFIG_BRIDGE_NETFILTER
 492 +       if (hook != NF_INET_FORWARD || (nskb->nf_bridge != NULL &&
 493 +           nskb->nf_bridge->mask & BRNF_BRIDGED))
 494 +#else
 495 +       if (hook != NF_INET_FORWARD)
 496 +#endif
 497 +               addr_type = RTN_LOCAL;
 498 +
 499 +       if (ip_route_me_harder(nskb, addr_type))
 500 +               goto free_nskb;
 501 +
 502 +       nskb->ip_summed = CHECKSUM_NONE;
 503 +
 504 +       /* Adjust IP TTL */
 505 +       niph->ttl = dst_metric(nskb->dst, RTAX_HOPLIMIT);
 506 +
 507 +       /* Adjust IP checksum */
 508 +       niph->check = 0;
 509 +       niph->check = ip_fast_csum(skb_network_header(nskb), niph->ihl);
 510 +
 511 +       /* "Never happens" */
 512 +       if (nskb->len > dst_mtu(nskb->dst))
 513 +               goto free_nskb;
 514 +
 515 +       nf_ct_attach(nskb, oldskb);
 516 +
 517 +       NF_HOOK(PF_INET, NF_INET_LOCAL_OUT, nskb, NULL, nskb->dst->dev,
 518 +               dst_output);
 519 +       return;
 520 +
 521 + free_nskb:
 522 +       kfree_skb(nskb);
 523 +}
 524 +
 525 +static unsigned int delude_tg(struct sk_buff *skb,
 526 +    const struct net_device *in, const struct net_device *out,
 527 +    unsigned int hooknum, const struct xt_target *target, const void *targinfo)
 528 +{
 529 +       /* WARNING: This code causes reentry within iptables.
 530 +          This means that the iptables jump stack is now crap.  We
 531 +          must return an absolute verdict. --RR */
 532 +       delude_send_reset(skb, hooknum);
 533 +       return NF_DROP;
 534 +}
 535 +
 536 +static struct xt_target delude_tg_reg = {
 537 +       .name       = "DELUDE",
 538 +       .family     = AF_INET,
 539 +       .table      = "filter",
 540 +       .hooks      = (1 << NF_INET_LOCAL_IN) | (1 << NF_INET_FORWARD),
 541 +       .target     = delude_tg,
 542 +       .proto      = IPPROTO_TCP,
 543 +       .me         = THIS_MODULE,
 544 +};
 545 +
 546 +static int __init delude_tg_init(void)
 547 +{
 548 +       return xt_register_target(&delude_tg_reg);
 549 +}
 550 +
 551 +static void __exit delude_tg_exit(void)
 552 +{
 553 +       xt_unregister_target(&delude_tg_reg);
 554 +}
 555 +
 556 +module_init(delude_tg_init);
 557 +module_exit(delude_tg_exit);
 558 +MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
 559 +MODULE_DESCRIPTION("netfilter \"DELUDE\" target");
 560 +MODULE_LICENSE("GPL");
 561 +MODULE_ALIAS("ipt_DELUDE");
 562 --- /dev/null
 563 +++ b/net/netfilter/xt_portscan.c
 564 @@ -0,0 +1,269 @@
 565 +/*
 566 + *     portscan match for netfilter
 567 + *     Copyright © CC Computer Consultants GmbH, 2006 - 2007
 568 + *     Contact: Jan Engelhardt <jengelh@computergmbh.de>
 569 + *
 570 + *     This program is free software; you can redistribute it and/or modify
 571 + *     it under the terms of the GNU General Public License; either version
 572 + *     2 or 3 as published by the Free Software Foundation.
 573 + */
 574 +#include <linux/in.h>
 575 +#include <linux/ip.h>
 576 +#include <linux/module.h>
 577 +#include <linux/moduleparam.h>
 578 +#include <linux/skbuff.h>
 579 +#include <linux/stat.h>
 580 +#include <linux/tcp.h>
 581 +#include <linux/types.h>
 582 +#include <linux/version.h>
 583 +#include <linux/netfilter/x_tables.h>
 584 +#include <linux/netfilter/xt_tcpudp.h>
 585 +#include <net/netfilter/nf_nat_rule.h>
 586 +#if defined(_LOCAL)
 587 +#      include "xt_portscan.h"
 588 +#elif defined(CONFIG_NETFILTER_XT_MATCH_PORTSCAN) || \
 589 +    defined(CONFIG_NETFILTER_XT_MATCH_PORTSCAN_MODULE)
 590 +#      include <linux/netfilter/xt_portscan.h>
 591 +#else
 592 +#      include "xt_portscan.h"
 593 +#endif
 594 +#define PFX KBUILD_MODNAME ": "
 595 +
 596 +enum {
 597 +       TCP_FLAGS_ALL3 = TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_SYN,
 598 +       TCP_FLAGS_ALL4 = TCP_FLAGS_ALL3 | TCP_FLAG_ACK,
 599 +       TCP_FLAGS_ALL6 = TCP_FLAGS_ALL4 | TCP_FLAG_PSH | TCP_FLAG_URG,
 600 +};
 601 +
 602 +/* Module parameters */
 603 +static unsigned int
 604 +       connmark_mask = ~0,
 605 +       packet_mask   = ~0,
 606 +       mark_seen     = 0x9,
 607 +       mark_synrcv   = 0x1,
 608 +       mark_closed   = 0x2,
 609 +       mark_synscan  = 0x3,
 610 +       mark_estab1   = 0x4,
 611 +       mark_estab2   = 0x5,
 612 +       mark_cnscan   = 0x6,
 613 +       mark_grscan   = 0x7,
 614 +       mark_valid    = 0x8;
 615 +
 616 +module_param(connmark_mask, uint, S_IRUGO | S_IWUSR);
 617 +module_param(packet_mask,   uint, S_IRUGO | S_IWUSR);
 618 +module_param(mark_seen,     uint, S_IRUGO | S_IWUSR);
 619 +module_param(mark_synrcv,   uint, S_IRUGO | S_IWUSR);
 620 +module_param(mark_closed,   uint, S_IRUGO | S_IWUSR);
 621 +module_param(mark_synscan,  uint, S_IRUGO | S_IWUSR);
 622 +module_param(mark_estab1,   uint, S_IRUGO | S_IWUSR);
 623 +module_param(mark_estab2,   uint, S_IRUGO | S_IWUSR);
 624 +module_param(mark_cnscan,   uint, S_IRUGO | S_IWUSR);
 625 +module_param(mark_grscan,   uint, S_IRUGO | S_IWUSR);
 626 +module_param(mark_valid,    uint, S_IRUGO | S_IWUSR);
 627 +MODULE_PARM_DESC(connmark_mask, "only set specified bits in connection mark");
 628 +MODULE_PARM_DESC(packet_mask,   "only set specified bits in packet mark");
 629 +MODULE_PARM_DESC(mark_seen,     "nfmark value for packet-seen state");
 630 +MODULE_PARM_DESC(mark_synrcv,   "connmark value for SYN Received state");
 631 +MODULE_PARM_DESC(mark_closed,   "connmark value for closed state");
 632 +MODULE_PARM_DESC(mark_synscan,  "connmark value for SYN Scan state");
 633 +MODULE_PARM_DESC(mark_estab1,   "connmark value for Established-1 state");
 634 +MODULE_PARM_DESC(mark_estab2,   "connmark value for Established-2 state");
 635 +MODULE_PARM_DESC(mark_cnscan,   "connmark value for Connect Scan state");
 636 +MODULE_PARM_DESC(mark_grscan,   "connmark value for Grab Scan state");
 637 +MODULE_PARM_DESC(mark_valid,    "connmark value for Valid state");
 638 +
 639 +/* TCP flag functions */
 640 +static inline bool tflg_ack4(const struct tcphdr *th)
 641 +{
 642 +       return (tcp_flag_word(th) & TCP_FLAGS_ALL4) == TCP_FLAG_ACK;
 643 +}
 644 +
 645 +static inline bool tflg_ack6(const struct tcphdr *th)
 646 +{
 647 +       return (tcp_flag_word(th) & TCP_FLAGS_ALL6) == TCP_FLAG_ACK;
 648 +}
 649 +
 650 +static inline bool tflg_fin(const struct tcphdr *th)
 651 +{
 652 +       return (tcp_flag_word(th) & TCP_FLAGS_ALL3) == TCP_FLAG_FIN;
 653 +}
 654 +
 655 +static inline bool tflg_rst(const struct tcphdr *th)
 656 +{
 657 +       return (tcp_flag_word(th) & TCP_FLAGS_ALL3) == TCP_FLAG_RST;
 658 +}
 659 +
 660 +static inline bool tflg_rstack(const struct tcphdr *th)
 661 +{
 662 +       return (tcp_flag_word(th) & TCP_FLAGS_ALL4) ==
 663 +              (TCP_FLAG_ACK | TCP_FLAG_RST);
 664 +}
 665 +
 666 +static inline bool tflg_syn(const struct tcphdr *th)
 667 +{
 668 +       return (tcp_flag_word(th) & TCP_FLAGS_ALL4) == TCP_FLAG_SYN;
 669 +}
 670 +
 671 +static inline bool tflg_synack(const struct tcphdr *th)
 672 +{
 673 +       return (tcp_flag_word(th) & TCP_FLAGS_ALL4) ==
 674 +              (TCP_FLAG_SYN | TCP_FLAG_ACK);
 675 +}
 676 +
 677 +/* portscan functions */
 678 +static inline bool portscan_mt_stealth(const struct tcphdr *th)
 679 +{
 680 +       /*
 681 +        * "Connection refused" replies to our own probes must not be matched.
 682 +        */
 683 +       if (tflg_rstack(th))
 684 +               return false;
 685 +
 686 +       if (tflg_rst(th) && printk_ratelimit()) {
 687 +               printk(KERN_WARNING PFX "Warning: Pure RST received\n");
 688 +               return false;
 689 +       }
 690 +
 691 +       /*
 692 +        * -p tcp ! --syn -m conntrack --ctstate INVALID: Looking for non-start
 693 +        * packets that are not associated with any connection -- this will
 694 +        * match most scan types (NULL, XMAS, FIN) and ridiculous flag
 695 +        * combinations (SYN-RST, SYN-FIN, SYN-FIN-RST, FIN-RST, etc.).
 696 +        */
 697 +       return !tflg_syn(th);
 698 +}
 699 +
 700 +static inline unsigned int portscan_mt_full(int mark,
 701 +    enum ip_conntrack_info ctstate, bool loopback, const struct tcphdr *tcph,
 702 +    unsigned int payload_len)
 703 +{
 704 +       if (mark == mark_estab2) {
 705 +               /*
 706 +                * -m connmark --mark $ESTAB2
 707 +                */
 708 +               if (tflg_ack4(tcph) && payload_len == 0)
 709 +                       return mark; /* keep mark */
 710 +               else if (tflg_rst(tcph) || tflg_fin(tcph))
 711 +                       return mark_grscan;
 712 +               else
 713 +                       return mark_valid;
 714 +       } else if (mark == mark_estab1) {
 715 +               /*
 716 +                * -m connmark --mark $ESTAB1
 717 +                */
 718 +               if (tflg_rst(tcph) || tflg_fin(tcph))
 719 +                       return mark_cnscan;
 720 +               else if (!loopback && tflg_ack4(tcph) && payload_len == 0)
 721 +                       return mark_estab2;
 722 +               else
 723 +                       return mark_valid;
 724 +       } else if (mark == mark_synrcv) {
 725 +               /*
 726 +                * -m connmark --mark $SYN
 727 +                */
 728 +               if (loopback && tflg_synack(tcph))
 729 +                       return mark; /* keep mark */
 730 +               else if (loopback && tflg_rstack(tcph))
 731 +                       return mark_closed;
 732 +               else if (tflg_ack6(tcph))
 733 +                       return mark_estab1;
 734 +               else
 735 +                       return mark_synscan;
 736 +       } else if (ctstate == IP_CT_NEW && tflg_syn(tcph)) {
 737 +               /*
 738 +                * -p tcp --syn --ctstate NEW
 739 +                */
 740 +               return mark_synrcv;
 741 +       }
 742 +       return mark;
 743 +}
 744 +
 745 +static bool portscan_mt(const struct sk_buff *skb,
 746 +    const struct net_device *in, const struct net_device *out,
 747 +    const struct xt_match *match, const void *matchinfo, int offset,
 748 +    unsigned int protoff, bool *hotdrop)
 749 +{
 750 +       const struct xt_portscan_match_info *info = matchinfo;
 751 +       enum ip_conntrack_info ctstate;
 752 +       const struct tcphdr *tcph;
 753 +       struct nf_conn *ctdata;
 754 +       struct tcphdr tcph_buf;
 755 +
 756 +       tcph = skb_header_pointer(skb, protoff, sizeof(tcph_buf), &tcph_buf);
 757 +       if (tcph == NULL)
 758 +               return false;
 759 +
 760 +       /* Check for invalid packets: -m conntrack --ctstate INVALID */
 761 +       if ((ctdata = nf_ct_get(skb, &ctstate)) == NULL) {
 762 +               if (info->match_stealth)
 763 +                       return portscan_mt_stealth(tcph);
 764 +               /*
 765 +                * If @ctdata is NULL, we cannot match the other scan
 766 +                * types, return.
 767 +                */
 768 +               return false;
 769 +       }
 770 +
 771 +       /*
 772 +        * If -m portscan was previously applied to this packet, the rules we
 773 +        * simulate must not be run through again. And for speedup, do not call
 774 +        * it either when the connection is already VALID.
 775 +        */
 776 +       if ((ctdata->mark & connmark_mask) == mark_valid ||
 777 +            (skb->mark & packet_mask) != mark_seen) {
 778 +               unsigned int n;
 779 +
 780 +               n = portscan_mt_full(ctdata->mark & connmark_mask, ctstate,
 781 +                   (in->flags & IFF_LOOPBACK) == IFF_LOOPBACK, tcph,
 782 +                   skb->len - protoff - 4 * tcph->doff);
 783 +
 784 +               ctdata->mark = (ctdata->mark & ~connmark_mask) | n;
 785 +               ((struct sk_buff *)skb)->mark =
 786 +                       (skb->mark & ~packet_mask) ^ mark_seen;
 787 +       }
 788 +
 789 +       return (info->match_syn && ctdata->mark == mark_synscan) ||
 790 +              (info->match_cn && ctdata->mark == mark_cnscan) ||
 791 +              (info->match_gr && ctdata->mark == mark_grscan);
 792 +}
 793 +
 794 +static bool portscan_mt_check(const char *tablename, const void *entry,
 795 +    const struct xt_match *match, void *matchinfo, unsigned int hook_mask)
 796 +{
 797 +       const struct xt_portscan_match_info *info = matchinfo;
 798 +
 799 +       if ((info->match_stealth & ~1) || (info->match_syn & ~1) ||
 800 +           (info->match_cn & ~1) || (info->match_gr & ~1)) {
 801 +               printk(KERN_WARNING PFX "Invalid flags\n");
 802 +               return false;
 803 +       }
 804 +       return true;
 805 +}
 806 +
 807 +static struct xt_match portscan_mt_reg __read_mostly = {
 808 +       .name       = "portscan",
 809 +       .family     = AF_INET,
 810 +       .match      = portscan_mt,
 811 +       .checkentry = portscan_mt_check,
 812 +       .matchsize  = sizeof(struct xt_portscan_match_info),
 813 +       .proto      = IPPROTO_TCP,
 814 +       .me         = THIS_MODULE,
 815 +};
 816 +
 817 +static int __init portscan_mt_init(void)
 818 +{
 819 +       return xt_register_match(&portscan_mt_reg);
 820 +}
 821 +
 822 +static void __exit portscan_mt_exit(void)
 823 +{
 824 +       xt_unregister_match(&portscan_mt_reg);
 825 +       return;
 826 +}
 827 +
 828 +module_init(portscan_mt_init);
 829 +module_exit(portscan_mt_exit);
 830 +MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
 831 +MODULE_DESCRIPTION("netfilter \"portscan\" match");
 832 +MODULE_LICENSE("GPL");
 833 +MODULE_ALIAS("ipt_portscan");
 834 --- a/drivers/char/random.c
 835 +++ b/drivers/char/random.c
 836 @@ -1555,6 +1555,8 @@ __u32 secure_tcp_sequence_number(__be32
 837         return seq;
 838  }
 839
 840 +EXPORT_SYMBOL(secure_tcp_sequence_number);
 841 +
 842  /* Generate secure starting point for ephemeral IPV4 transport port search */
 843  u32 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport)
 844  {