target/linux/generic-2.6/patches-2.6.28/170-netfilter_chaostables_0.8.patch

   1 --- a/include/linux/netfilter/Kbuild
   2 +++ b/include/linux/netfilter/Kbuild
   3 @@ -3,6 +3,7 @@ header-y += nf_conntrack_tuple_common.h
   4  header-y += nfnetlink_conntrack.h
   5  header-y += nfnetlink_log.h
   6  header-y += nfnetlink_queue.h
   7 +header-y += xt_CHAOS.h
   8  header-y += xt_CLASSIFY.h
   9  header-y += xt_CONNMARK.h
  10  header-y += xt_CONNSECMARK.h
  11 --- /dev/null
  12 +++ b/include/linux/netfilter/oot_conntrack.h
  13 @@ -0,0 +1,5 @@
  14 +#if defined(CONFIG_IP_NF_CONNTRACK) || defined(CONFIG_IP_NF_CONNTRACK_MODULE)
  15 +#      include <linux/netfilter_ipv4/ip_conntrack.h>
  16 +#else /* linux-2.6.20+ */
  17 +#      include <net/netfilter/nf_nat_rule.h>
  18 +#endif
  19 --- /dev/null
  20 +++ b/include/linux/netfilter/oot_trans.h
  21 @@ -0,0 +1,14 @@
  22 +/* Out of tree workarounds */
  23 +#include <linux/version.h>
  24 +#if LINUX_VERSION_CODE <= KERNEL_VERSION(2, 6, 18)
  25 +#      define HAVE_MATCHINFOSIZE 1
  26 +#      define HAVE_TARGUSERINFO 1
  27 +#      define HAVE_TARGINFOSIZE 1
  28 +#endif
  29 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 20)
  30 +#      define nfmark mark
  31 +#endif
  32 +#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 21)
  33 +#      define tcp_v4_check(tcph, tcph_sz, s, d, csp) \
  34 +               tcp_v4_check((tcph_sz), (s), (d), (csp))
  35 +#endif
  36 --- /dev/null
  37 +++ b/include/linux/netfilter/xt_CHAOS.h
  38 @@ -0,0 +1,14 @@
  39 +#ifndef _LINUX_NETFILTER_XT_CHAOS_H
  40 +#define _LINUX_NETFILTER_XT_CHAOS_H 1
  41 +
  42 +enum xt_chaos_target_variant {
  43 +       XTCHAOS_NORMAL,
  44 +       XTCHAOS_TARPIT,
  45 +       XTCHAOS_DELUDE,
  46 +};
  47 +
  48 +struct xt_chaos_target_info {
  49 +       uint8_t variant;
  50 +};
  51 +
  52 +#endif /* _LINUX_NETFILTER_XT_CHAOS_H */
  53 --- /dev/null
  54 +++ b/include/linux/netfilter/xt_portscan.h
  55 @@ -0,0 +1,8 @@
  56 +#ifndef _LINUX_NETFILTER_XT_PORTSCAN_H
  57 +#define _LINUX_NETFILTER_XT_PORTSCAN_H 1
  58 +
  59 +struct xt_portscan_match_info {
  60 +       uint8_t match_stealth, match_syn, match_cn, match_gr;
  61 +};
  62 +
  63 +#endif /* _LINUX_NETFILTER_XT_PORTSCAN_H */
  64 --- /dev/null
  65 +++ b/net/netfilter/find_match.c
  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 --- a/net/netfilter/Kconfig
 107 +++ b/net/netfilter/Kconfig
 108 @@ -303,6 +303,14 @@ if NETFILTER_XTABLES
 109
 110  # alphabetically ordered list of targets
 111
 112 +config NETFILTER_XT_TARGET_CHAOS
 113 +       tristate '"CHAOS" target support'
 114 +       depends on NETFILTER_XTABLES
 115 +       help
 116 +         This option adds a `CHAOS' target.
 117 +
 118 +         To compile it as a module, choose M here.  If unsure, say N.
 119 +
 120  config NETFILTER_XT_TARGET_CLASSIFY
 121         tristate '"CLASSIFY" target support'
 122         depends on NETFILTER_ADVANCED
 123 @@ -341,6 +349,14 @@ config NETFILTER_XT_TARGET_CONNSECMARK
 124
 125           To compile it as a module, choose M here.  If unsure, say N.
 126
 127 +config NETFILTER_XT_TARGET_DELUDE
 128 +       tristate '"DELUDE" target support'
 129 +       depends on NETFILTER_XTABLES
 130 +       help
 131 +         This option adds a `DELUDE' target.
 132 +
 133 +         To compile it as a module, choose M here.  If unsure, say N.
 134 +
 135  config NETFILTER_XT_TARGET_DSCP
 136         tristate '"DSCP" and "TOS" target support'
 137         depends on IP_NF_MANGLE || IP6_NF_MANGLE
 138 @@ -654,6 +670,14 @@ config NETFILTER_XT_MATCH_MARK
 139
 140           To compile it as a module, choose M here.  If unsure, say N.
 141
 142 +config NETFILTER_XT_MATCH_PORTSCAN
 143 +       tristate '"portscan" match support'
 144 +       depends on NETFILTER_XTABLES
 145 +       help
 146 +         This option adds a 'portscan' match support.
 147 +
 148 +         To compile it as a module, choose M here.  If unsure, say N.
 149 +
 150  config NETFILTER_XT_MATCH_MULTIPORT
 151         tristate '"multiport" Multiple port match support'
 152         depends on NETFILTER_ADVANCED
 153 --- a/net/netfilter/Makefile
 154 +++ b/net/netfilter/Makefile
 155 @@ -55,6 +55,8 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_TPROXY)
 156  obj-$(CONFIG_NETFILTER_XT_TARGET_TCPMSS) += xt_TCPMSS.o
 157  obj-$(CONFIG_NETFILTER_XT_TARGET_TCPOPTSTRIP) += xt_TCPOPTSTRIP.o
 158  obj-$(CONFIG_NETFILTER_XT_TARGET_TRACE) += xt_TRACE.o
 159 +obj-$(CONFIG_NETFILTER_XT_TARGET_CHAOS) += xt_CHAOS.o
 160 +obj-$(CONFIG_NETFILTER_XT_TARGET_DELUDE) += xt_DELUDE.o
 161
 162  # matches
 163  obj-$(CONFIG_NETFILTER_XT_MATCH_COMMENT) += xt_comment.o
 164 @@ -90,6 +92,7 @@ obj-$(CONFIG_NETFILTER_XT_MATCH_STRING)
 165  obj-$(CONFIG_NETFILTER_XT_MATCH_TCPMSS) += xt_tcpmss.o
 166  obj-$(CONFIG_NETFILTER_XT_MATCH_TIME) += xt_time.o
 167  obj-$(CONFIG_NETFILTER_XT_MATCH_U32) += xt_u32.o
 168 +obj-$(CONFIG_NETFILTER_XT_MATCH_PORTSCAN) += xt_portscan.o
 169
 170  # IPVS
 171  obj-$(CONFIG_IP_VS) += ipvs/
 172 --- /dev/null
 173 +++ b/net/netfilter/xt_CHAOS.c
 174 @@ -0,0 +1,200 @@
 175 +/*
 176 + *     CHAOS target for netfilter
 177 + *     Copyright © CC Computer Consultants GmbH, 2006 - 2007
 178 + *     Contact: Jan Engelhardt <jengelh@computergmbh.de>
 179 + *
 180 + *     This program is free software; you can redistribute it and/or modify
 181 + *     it under the terms of the GNU General Public License; either version
 182 + *     2 or 3 as published by the Free Software Foundation.
 183 + */
 184 +#include <linux/icmp.h>
 185 +#include <linux/in.h>
 186 +#include <linux/ip.h>
 187 +#include <linux/module.h>
 188 +#include <linux/skbuff.h>
 189 +#include <linux/stat.h>
 190 +#include <linux/netfilter/x_tables.h>
 191 +#include <linux/netfilter/xt_tcpudp.h>
 192 +#include <linux/netfilter_ipv4/ipt_REJECT.h>
 193 +#include <net/ip.h>
 194 +#if defined(_LOCAL)
 195 +#      include "xt_CHAOS.h"
 196 +#      include "find_match.c"
 197 +#elif defined(CONFIG_NETFILTER_XT_TARGET_CHAOS) || \
 198 +    defined(CONFIG_NETFILTER_XT_TARGET_CHAOS_MODULE)
 199 +#      include <linux/netfilter/xt_CHAOS.h>
 200 +#      include "find_match.c"
 201 +#else
 202 +#      include "xt_CHAOS.h"
 203 +#      include "find_match.c"
 204 +#endif
 205 +#define PFX KBUILD_MODNAME ": "
 206 +
 207 +/* Module parameters */
 208 +static unsigned int reject_percentage = ~0U * .01;
 209 +static unsigned int delude_percentage = ~0U * .0101;
 210 +module_param(reject_percentage, uint, S_IRUGO | S_IWUSR);
 211 +module_param(delude_percentage, uint, S_IRUGO | S_IWUSR);
 212 +
 213 +/* References to other matches/targets */
 214 +static struct xt_match *xm_tcp;
 215 +static struct xt_target *xt_delude, *xt_reject, *xt_tarpit;
 216 +
 217 +static int have_delude, have_tarpit;
 218 +
 219 +/* Static data for other matches/targets */
 220 +static const struct ipt_reject_info reject_params = {
 221 +       .with = ICMP_HOST_UNREACH,
 222 +};
 223 +
 224 +static const struct xt_tcp tcp_params = {
 225 +       .spts = {0, ~0},
 226 +       .dpts = {0, ~0},
 227 +};
 228 +
 229 +/* CHAOS functions */
 230 +static void xt_chaos_total(const struct xt_chaos_target_info *info,
 231 +    struct sk_buff *skb, const struct net_device *in,
 232 +    const struct net_device *out, unsigned int hooknum)
 233 +{
 234 +       const struct iphdr *iph = ip_hdr(skb);
 235 +       const int protoff       = 4 * iph->ihl;
 236 +       const int offset        = ntohs(iph->frag_off) & IP_OFFSET;
 237 +       const struct xt_target *destiny;
 238 +       bool hotdrop = false, ret;
 239 +
 240 +       ret = xm_tcp->match(skb, in, out, xm_tcp, &tcp_params,
 241 +                           offset, protoff, &hotdrop);
 242 +       if (!ret || hotdrop || (unsigned int)net_random() > delude_percentage)
 243 +               return;
 244 +
 245 +       destiny = (info->variant == XTCHAOS_TARPIT) ? xt_tarpit : xt_delude;
 246 +       destiny->target(skb, in, out, hooknum, destiny, NULL);
 247 +       return;
 248 +}
 249 +
 250 +static unsigned int chaos_tg(struct sk_buff *skb,
 251 +    const struct net_device *in, const struct net_device *out,
 252 +    unsigned int hooknum, const struct xt_target *target, const void *targinfo)
 253 +{
 254 +       /*
 255 +        * Equivalent to:
 256 +        * -A chaos -m statistic --mode random --probability \
 257 +        *         $reject_percentage -j REJECT --reject-with host-unreach;
 258 +        * -A chaos -p tcp -m statistic --mode random --probability \
 259 +        *         $delude_percentage -j DELUDE;
 260 +        * -A chaos -j DROP;
 261 +        */
 262 +       const struct xt_chaos_target_info *info = targinfo;
 263 +       const struct iphdr *iph = ip_hdr(skb);
 264 +
 265 +       if ((unsigned int)net_random() <= reject_percentage)
 266 +               return xt_reject->target(skb, in, out, hooknum, target,
 267 +                      &reject_params);
 268 +
 269 +       /* TARPIT/DELUDE may not be called from the OUTPUT chain */
 270 +       if (iph->protocol == IPPROTO_TCP &&
 271 +           info->variant != XTCHAOS_NORMAL && hooknum != NF_INET_LOCAL_OUT)
 272 +               xt_chaos_total(info, skb, in, out, hooknum);
 273 +
 274 +       return NF_DROP;
 275 +}
 276 +
 277 +static bool chaos_tg_check(const char *tablename, const void *entry,
 278 +    const struct xt_target *target, void *targinfo, unsigned int hook_mask)
 279 +{
 280 +       const struct xt_chaos_target_info *info = targinfo;
 281 +
 282 +       if (info->variant == XTCHAOS_DELUDE && !have_delude) {
 283 +               printk(KERN_WARNING PFX "Error: Cannot use --delude when "
 284 +                      "DELUDE module not available\n");
 285 +               return false;
 286 +       }
 287 +       if (info->variant == XTCHAOS_TARPIT && !have_tarpit) {
 288 +               printk(KERN_WARNING PFX "Error: Cannot use --tarpit when "
 289 +                      "TARPIT module not available\n");
 290 +               return false;
 291 +       }
 292 +
 293 +       return true;
 294 +}
 295 +
 296 +static struct xt_target chaos_tg_reg = {
 297 +       .name       = "CHAOS",
 298 +       .family     = AF_INET,
 299 +       .table      = "filter",
 300 +       .hooks      = (1 << NF_INET_LOCAL_IN) | (1 << NF_INET_FORWARD) |
 301 +                     (1 << NF_INET_LOCAL_OUT),
 302 +       .checkentry = chaos_tg_check,
 303 +       .target     = chaos_tg,
 304 +       .targetsize = sizeof(struct xt_chaos_target_info),
 305 +       .me         = THIS_MODULE,
 306 +};
 307 +
 308 +static int __init chaos_tg_init(void)
 309 +{
 310 +       int ret = -EINVAL;
 311 +
 312 +       xm_tcp = xt_request_find_match(AF_INET, "tcp", 0);
 313 +       if (xm_tcp == NULL) {
 314 +               printk(KERN_WARNING PFX "Error: Could not find or load "
 315 +                      "\"tcp\" match\n");
 316 +               return -EINVAL;
 317 +       }
 318 +
 319 +       xt_reject = xt_request_find_target(AF_INET, "REJECT", 0);
 320 +       if (xt_reject == NULL) {
 321 +               printk(KERN_WARNING PFX "Error: Could not find or load "
 322 +                      "\"REJECT\" target\n");
 323 +               goto out2;
 324 +       }
 325 +
 326 +       xt_tarpit   = xt_request_find_target(AF_INET, "TARPIT", 0);
 327 +       have_tarpit = xt_tarpit != NULL;
 328 +       if (!have_tarpit)
 329 +               printk(KERN_WARNING PFX "Warning: Could not find or load "
 330 +                      "\"TARPIT\" target\n");
 331 +
 332 +       xt_delude   = xt_request_find_target(AF_INET, "DELUDE", 0);
 333 +       have_delude = xt_delude != NULL;
 334 +       if (!have_delude)
 335 +               printk(KERN_WARNING PFX "Warning: Could not find or load "
 336 +                      "\"DELUDE\" target\n");
 337 +
 338 +       if ((ret = xt_register_target(&chaos_tg_reg)) != 0) {
 339 +               printk(KERN_WARNING PFX "xt_register_target returned "
 340 +                      "error %d\n", ret);
 341 +               goto out3;
 342 +       }
 343 +
 344 +       return 0;
 345 +
 346 + out3:
 347 +       if (have_delude)
 348 +               module_put(xt_delude->me);
 349 +       if (have_tarpit)
 350 +               module_put(xt_tarpit->me);
 351 +       module_put(xt_reject->me);
 352 + out2:
 353 +       module_put(xm_tcp->me);
 354 +       return ret;
 355 +}
 356 +
 357 +static void __exit chaos_tg_exit(void)
 358 +{
 359 +       xt_unregister_target(&chaos_tg_reg);
 360 +       module_put(xm_tcp->me);
 361 +       module_put(xt_reject->me);
 362 +       if (have_delude)
 363 +               module_put(xt_delude->me);
 364 +       if (have_tarpit)
 365 +               module_put(xt_tarpit->me);
 366 +       return;
 367 +}
 368 +
 369 +module_init(chaos_tg_init);
 370 +module_exit(chaos_tg_exit);
 371 +MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
 372 +MODULE_DESCRIPTION("netfilter \"CHAOS\" target");
 373 +MODULE_LICENSE("GPL");
 374 +MODULE_ALIAS("ipt_CHAOS");
 375 --- /dev/null
 376 +++ b/net/netfilter/xt_DELUDE.c
 377 @@ -0,0 +1,197 @@
 378 +/*
 379 + *     DELUDE target
 380 + *     Copyright © CC Computer Consultants GmbH, 2007
 381 + *     Contact: Jan Engelhardt <jengelh@computergmbh.de>
 382 + *
 383 + *     Based upon linux-2.6.18.5/net/ipv4/netfilter/ipt_REJECT.c:
 384 + *     (C) 1999-2001 Paul `Rusty' Russell
 385 + *     (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
 386 + *
 387 + *     xt_DELUDE acts like REJECT, but does reply with SYN-ACK on SYN.
 388 + *
 389 + *     This program is free software; you can redistribute it and/or modify
 390 + *     it under the terms of the GNU General Public License version 2 as
 391 + *     published by the Free Software Foundation.
 392 + */
 393 +#include <linux/module.h>
 394 +#include <linux/skbuff.h>
 395 +#include <linux/ip.h>
 396 +#include <linux/tcp.h>
 397 +#include <linux/netfilter/x_tables.h>
 398 +#ifdef CONFIG_BRIDGE_NETFILTER
 399 +#      include <linux/netfilter_bridge.h>
 400 +#endif
 401 +#include <net/tcp.h>
 402 +#define PFX KBUILD_MODNAME ": "
 403 +
 404 +static void delude_send_reset(struct sk_buff *oldskb, unsigned int hook)
 405 +{
 406 +       struct tcphdr _otcph, *oth, *tcph;
 407 +       unsigned int addr_type;
 408 +       struct sk_buff *nskb;
 409 +       u_int16_t tmp_port;
 410 +       u_int32_t tmp_addr;
 411 +       struct iphdr *niph;
 412 +       bool needs_ack;
 413 +
 414 +       /* IP header checks: fragment. */
 415 +       if (ip_hdr(oldskb)->frag_off & htons(IP_OFFSET))
 416 +               return;
 417 +
 418 +       oth = skb_header_pointer(oldskb, ip_hdrlen(oldskb),
 419 +                                sizeof(_otcph), &_otcph);
 420 +       if (oth == NULL)
 421 +               return;
 422 +
 423 +       /* No RST for RST. */
 424 +       if (oth->rst)
 425 +               return;
 426 +
 427 +       /* Check checksum */
 428 +       if (nf_ip_checksum(oldskb, hook, ip_hdrlen(oldskb), IPPROTO_TCP))
 429 +               return;
 430 +
 431 +       /* We need a linear, writeable skb.  We also need to expand
 432 +          headroom in case hh_len of incoming interface < hh_len of
 433 +          outgoing interface */
 434 +       nskb = skb_copy_expand(oldskb, LL_MAX_HEADER, skb_tailroom(oldskb),
 435 +                              GFP_ATOMIC);
 436 +       if (!nskb)
 437 +               return;
 438 +
 439 +       /* This packet will not be the same as the other: clear nf fields */
 440 +       nf_reset(nskb);
 441 +       nskb->mark = 0;
 442 +       skb_init_secmark(nskb);
 443 +
 444 +       skb_shinfo(nskb)->gso_size = 0;
 445 +       skb_shinfo(nskb)->gso_segs = 0;
 446 +       skb_shinfo(nskb)->gso_type = 0;
 447 +
 448 +       tcph = (struct tcphdr *)(skb_network_header(nskb) + ip_hdrlen(nskb));
 449 +
 450 +       /* Swap source and dest */
 451 +       niph         = ip_hdr(nskb);
 452 +       tmp_addr     = niph->saddr;
 453 +       niph->saddr  = niph->daddr;
 454 +       niph->daddr  = tmp_addr;
 455 +       tmp_port     = tcph->source;
 456 +       tcph->source = tcph->dest;
 457 +       tcph->dest   = tmp_port;
 458 +
 459 +       /* Truncate to length (no data) */
 460 +       tcph->doff    = sizeof(struct tcphdr) / 4;
 461 +       skb_trim(nskb, ip_hdrlen(nskb) + sizeof(struct tcphdr));
 462 +       niph->tot_len = htons(nskb->len);
 463 +
 464 +       if (oth->syn && !oth->ack && !oth->rst && !oth->fin) {
 465 +               /* DELUDE essential part */
 466 +               tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn + oth->fin +
 467 +                               oldskb->len - ip_hdrlen(oldskb) -
 468 +                               (oth->doff << 2));
 469 +               tcph->seq     = false;
 470 +               tcph->ack     = true;
 471 +       } else {
 472 +               if (!tcph->ack) {
 473 +                       needs_ack     = true;
 474 +                       tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn +
 475 +                                       oth->fin + oldskb->len -
 476 +                                       ip_hdrlen(oldskb) - (oth->doff<<2));
 477 +                       tcph->seq     = false;
 478 +               } else {
 479 +                       needs_ack     = false;
 480 +                       tcph->seq     = oth->ack_seq;
 481 +                       tcph->ack_seq = false;
 482 +               }
 483 +
 484 +               /* Reset flags */
 485 +               ((u_int8_t *)tcph)[13] = 0;
 486 +               tcph->rst = true;
 487 +               tcph->ack = needs_ack;
 488 +       }
 489 +
 490 +       tcph->window  = 0;
 491 +       tcph->urg_ptr = 0;
 492 +
 493 +       /* Adjust TCP checksum */
 494 +       tcph->check = 0;
 495 +       tcph->check = tcp_v4_check(sizeof(struct tcphdr), niph->saddr,
 496 +                     niph->daddr, csum_partial((char *)tcph,
 497 +                     sizeof(struct tcphdr), 0));
 498 +
 499 +       /* Set DF, id = 0 */
 500 +       niph->frag_off = htons(IP_DF);
 501 +       niph->id       = 0;
 502 +
 503 +       addr_type = RTN_UNSPEC;
 504 +#ifdef CONFIG_BRIDGE_NETFILTER
 505 +       if (hook != NF_INET_FORWARD || (nskb->nf_bridge != NULL &&
 506 +           nskb->nf_bridge->mask & BRNF_BRIDGED))
 507 +#else
 508 +       if (hook != NF_INET_FORWARD)
 509 +#endif
 510 +               addr_type = RTN_LOCAL;
 511 +
 512 +       if (ip_route_me_harder(nskb, addr_type))
 513 +               goto free_nskb;
 514 +
 515 +       nskb->ip_summed = CHECKSUM_NONE;
 516 +
 517 +       /* Adjust IP TTL */
 518 +       niph->ttl = dst_metric(nskb->dst, RTAX_HOPLIMIT);
 519 +
 520 +       /* Adjust IP checksum */
 521 +       niph->check = 0;
 522 +       niph->check = ip_fast_csum(skb_network_header(nskb), niph->ihl);
 523 +
 524 +       /* "Never happens" */
 525 +       if (nskb->len > dst_mtu(nskb->dst))
 526 +               goto free_nskb;
 527 +
 528 +       nf_ct_attach(nskb, oldskb);
 529 +
 530 +       NF_HOOK(PF_INET, NF_INET_LOCAL_OUT, nskb, NULL, nskb->dst->dev,
 531 +               dst_output);
 532 +       return;
 533 +
 534 + free_nskb:
 535 +       kfree_skb(nskb);
 536 +}
 537 +
 538 +static unsigned int delude_tg(struct sk_buff *skb,
 539 +    const struct net_device *in, const struct net_device *out,
 540 +    unsigned int hooknum, const struct xt_target *target, const void *targinfo)
 541 +{
 542 +       /* WARNING: This code causes reentry within iptables.
 543 +          This means that the iptables jump stack is now crap.  We
 544 +          must return an absolute verdict. --RR */
 545 +       delude_send_reset(skb, hooknum);
 546 +       return NF_DROP;
 547 +}
 548 +
 549 +static struct xt_target delude_tg_reg = {
 550 +       .name       = "DELUDE",
 551 +       .family     = AF_INET,
 552 +       .table      = "filter",
 553 +       .hooks      = (1 << NF_INET_LOCAL_IN) | (1 << NF_INET_FORWARD),
 554 +       .target     = delude_tg,
 555 +       .proto      = IPPROTO_TCP,
 556 +       .me         = THIS_MODULE,
 557 +};
 558 +
 559 +static int __init delude_tg_init(void)
 560 +{
 561 +       return xt_register_target(&delude_tg_reg);
 562 +}
 563 +
 564 +static void __exit delude_tg_exit(void)
 565 +{
 566 +       xt_unregister_target(&delude_tg_reg);
 567 +}
 568 +
 569 +module_init(delude_tg_init);
 570 +module_exit(delude_tg_exit);
 571 +MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
 572 +MODULE_DESCRIPTION("netfilter \"DELUDE\" target");
 573 +MODULE_LICENSE("GPL");
 574 +MODULE_ALIAS("ipt_DELUDE");
 575 --- /dev/null
 576 +++ b/net/netfilter/xt_portscan.c
 577 @@ -0,0 +1,269 @@
 578 +/*
 579 + *     portscan match for netfilter
 580 + *     Copyright © CC Computer Consultants GmbH, 2006 - 2007
 581 + *     Contact: Jan Engelhardt <jengelh@computergmbh.de>
 582 + *
 583 + *     This program is free software; you can redistribute it and/or modify
 584 + *     it under the terms of the GNU General Public License; either version
 585 + *     2 or 3 as published by the Free Software Foundation.
 586 + */
 587 +#include <linux/in.h>
 588 +#include <linux/ip.h>
 589 +#include <linux/module.h>
 590 +#include <linux/moduleparam.h>
 591 +#include <linux/skbuff.h>
 592 +#include <linux/stat.h>
 593 +#include <linux/tcp.h>
 594 +#include <linux/types.h>
 595 +#include <linux/version.h>
 596 +#include <linux/netfilter/x_tables.h>
 597 +#include <linux/netfilter/xt_tcpudp.h>
 598 +#include <net/netfilter/nf_nat_rule.h>
 599 +#if defined(_LOCAL)
 600 +#      include "xt_portscan.h"
 601 +#elif defined(CONFIG_NETFILTER_XT_MATCH_PORTSCAN) || \
 602 +    defined(CONFIG_NETFILTER_XT_MATCH_PORTSCAN_MODULE)
 603 +#      include <linux/netfilter/xt_portscan.h>
 604 +#else
 605 +#      include "xt_portscan.h"
 606 +#endif
 607 +#define PFX KBUILD_MODNAME ": "
 608 +
 609 +enum {
 610 +       TCP_FLAGS_ALL3 = TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_SYN,
 611 +       TCP_FLAGS_ALL4 = TCP_FLAGS_ALL3 | TCP_FLAG_ACK,
 612 +       TCP_FLAGS_ALL6 = TCP_FLAGS_ALL4 | TCP_FLAG_PSH | TCP_FLAG_URG,
 613 +};
 614 +
 615 +/* Module parameters */
 616 +static unsigned int
 617 +       connmark_mask = ~0,
 618 +       packet_mask   = ~0,
 619 +       mark_seen     = 0x9,
 620 +       mark_synrcv   = 0x1,
 621 +       mark_closed   = 0x2,
 622 +       mark_synscan  = 0x3,
 623 +       mark_estab1   = 0x4,
 624 +       mark_estab2   = 0x5,
 625 +       mark_cnscan   = 0x6,
 626 +       mark_grscan   = 0x7,
 627 +       mark_valid    = 0x8;
 628 +
 629 +module_param(connmark_mask, uint, S_IRUGO | S_IWUSR);
 630 +module_param(packet_mask,   uint, S_IRUGO | S_IWUSR);
 631 +module_param(mark_seen,     uint, S_IRUGO | S_IWUSR);
 632 +module_param(mark_synrcv,   uint, S_IRUGO | S_IWUSR);
 633 +module_param(mark_closed,   uint, S_IRUGO | S_IWUSR);
 634 +module_param(mark_synscan,  uint, S_IRUGO | S_IWUSR);
 635 +module_param(mark_estab1,   uint, S_IRUGO | S_IWUSR);
 636 +module_param(mark_estab2,   uint, S_IRUGO | S_IWUSR);
 637 +module_param(mark_cnscan,   uint, S_IRUGO | S_IWUSR);
 638 +module_param(mark_grscan,   uint, S_IRUGO | S_IWUSR);
 639 +module_param(mark_valid,    uint, S_IRUGO | S_IWUSR);
 640 +MODULE_PARM_DESC(connmark_mask, "only set specified bits in connection mark");
 641 +MODULE_PARM_DESC(packet_mask,   "only set specified bits in packet mark");
 642 +MODULE_PARM_DESC(mark_seen,     "nfmark value for packet-seen state");
 643 +MODULE_PARM_DESC(mark_synrcv,   "connmark value for SYN Received state");
 644 +MODULE_PARM_DESC(mark_closed,   "connmark value for closed state");
 645 +MODULE_PARM_DESC(mark_synscan,  "connmark value for SYN Scan state");
 646 +MODULE_PARM_DESC(mark_estab1,   "connmark value for Established-1 state");
 647 +MODULE_PARM_DESC(mark_estab2,   "connmark value for Established-2 state");
 648 +MODULE_PARM_DESC(mark_cnscan,   "connmark value for Connect Scan state");
 649 +MODULE_PARM_DESC(mark_grscan,   "connmark value for Grab Scan state");
 650 +MODULE_PARM_DESC(mark_valid,    "connmark value for Valid state");
 651 +
 652 +/* TCP flag functions */
 653 +static inline bool tflg_ack4(const struct tcphdr *th)
 654 +{
 655 +       return (tcp_flag_word(th) & TCP_FLAGS_ALL4) == TCP_FLAG_ACK;
 656 +}
 657 +
 658 +static inline bool tflg_ack6(const struct tcphdr *th)
 659 +{
 660 +       return (tcp_flag_word(th) & TCP_FLAGS_ALL6) == TCP_FLAG_ACK;
 661 +}
 662 +
 663 +static inline bool tflg_fin(const struct tcphdr *th)
 664 +{
 665 +       return (tcp_flag_word(th) & TCP_FLAGS_ALL3) == TCP_FLAG_FIN;
 666 +}
 667 +
 668 +static inline bool tflg_rst(const struct tcphdr *th)
 669 +{
 670 +       return (tcp_flag_word(th) & TCP_FLAGS_ALL3) == TCP_FLAG_RST;
 671 +}
 672 +
 673 +static inline bool tflg_rstack(const struct tcphdr *th)
 674 +{
 675 +       return (tcp_flag_word(th) & TCP_FLAGS_ALL4) ==
 676 +              (TCP_FLAG_ACK | TCP_FLAG_RST);
 677 +}
 678 +
 679 +static inline bool tflg_syn(const struct tcphdr *th)
 680 +{
 681 +       return (tcp_flag_word(th) & TCP_FLAGS_ALL4) == TCP_FLAG_SYN;
 682 +}
 683 +
 684 +static inline bool tflg_synack(const struct tcphdr *th)
 685 +{
 686 +       return (tcp_flag_word(th) & TCP_FLAGS_ALL4) ==
 687 +              (TCP_FLAG_SYN | TCP_FLAG_ACK);
 688 +}
 689 +
 690 +/* portscan functions */
 691 +static inline bool portscan_mt_stealth(const struct tcphdr *th)
 692 +{
 693 +       /*
 694 +        * "Connection refused" replies to our own probes must not be matched.
 695 +        */
 696 +       if (tflg_rstack(th))
 697 +               return false;
 698 +
 699 +       if (tflg_rst(th) && printk_ratelimit()) {
 700 +               printk(KERN_WARNING PFX "Warning: Pure RST received\n");
 701 +               return false;
 702 +       }
 703 +
 704 +       /*
 705 +        * -p tcp ! --syn -m conntrack --ctstate INVALID: Looking for non-start
 706 +        * packets that are not associated with any connection -- this will
 707 +        * match most scan types (NULL, XMAS, FIN) and ridiculous flag
 708 +        * combinations (SYN-RST, SYN-FIN, SYN-FIN-RST, FIN-RST, etc.).
 709 +        */
 710 +       return !tflg_syn(th);
 711 +}
 712 +
 713 +static inline unsigned int portscan_mt_full(int mark,
 714 +    enum ip_conntrack_info ctstate, bool loopback, const struct tcphdr *tcph,
 715 +    unsigned int payload_len)
 716 +{
 717 +       if (mark == mark_estab2) {
 718 +               /*
 719 +                * -m connmark --mark $ESTAB2
 720 +                */
 721 +               if (tflg_ack4(tcph) && payload_len == 0)
 722 +                       return mark; /* keep mark */
 723 +               else if (tflg_rst(tcph) || tflg_fin(tcph))
 724 +                       return mark_grscan;
 725 +               else
 726 +                       return mark_valid;
 727 +       } else if (mark == mark_estab1) {
 728 +               /*
 729 +                * -m connmark --mark $ESTAB1
 730 +                */
 731 +               if (tflg_rst(tcph) || tflg_fin(tcph))
 732 +                       return mark_cnscan;
 733 +               else if (!loopback && tflg_ack4(tcph) && payload_len == 0)
 734 +                       return mark_estab2;
 735 +               else
 736 +                       return mark_valid;
 737 +       } else if (mark == mark_synrcv) {
 738 +               /*
 739 +                * -m connmark --mark $SYN
 740 +                */
 741 +               if (loopback && tflg_synack(tcph))
 742 +                       return mark; /* keep mark */
 743 +               else if (loopback && tflg_rstack(tcph))
 744 +                       return mark_closed;
 745 +               else if (tflg_ack6(tcph))
 746 +                       return mark_estab1;
 747 +               else
 748 +                       return mark_synscan;
 749 +       } else if (ctstate == IP_CT_NEW && tflg_syn(tcph)) {
 750 +               /*
 751 +                * -p tcp --syn --ctstate NEW
 752 +                */
 753 +               return mark_synrcv;
 754 +       }
 755 +       return mark;
 756 +}
 757 +
 758 +static bool portscan_mt(const struct sk_buff *skb,
 759 +    const struct net_device *in, const struct net_device *out,
 760 +    const struct xt_match *match, const void *matchinfo, int offset,
 761 +    unsigned int protoff, bool *hotdrop)
 762 +{
 763 +       const struct xt_portscan_match_info *info = matchinfo;
 764 +       enum ip_conntrack_info ctstate;
 765 +       const struct tcphdr *tcph;
 766 +       struct nf_conn *ctdata;
 767 +       struct tcphdr tcph_buf;
 768 +
 769 +       tcph = skb_header_pointer(skb, protoff, sizeof(tcph_buf), &tcph_buf);
 770 +       if (tcph == NULL)
 771 +               return false;
 772 +
 773 +       /* Check for invalid packets: -m conntrack --ctstate INVALID */
 774 +       if ((ctdata = nf_ct_get(skb, &ctstate)) == NULL) {
 775 +               if (info->match_stealth)
 776 +                       return portscan_mt_stealth(tcph);
 777 +               /*
 778 +                * If @ctdata is NULL, we cannot match the other scan
 779 +                * types, return.
 780 +                */
 781 +               return false;
 782 +       }
 783 +
 784 +       /*
 785 +        * If -m portscan was previously applied to this packet, the rules we
 786 +        * simulate must not be run through again. And for speedup, do not call
 787 +        * it either when the connection is already VALID.
 788 +        */
 789 +       if ((ctdata->mark & connmark_mask) == mark_valid ||
 790 +            (skb->mark & packet_mask) != mark_seen) {
 791 +               unsigned int n;
 792 +
 793 +               n = portscan_mt_full(ctdata->mark & connmark_mask, ctstate,
 794 +                   (in->flags & IFF_LOOPBACK) == IFF_LOOPBACK, tcph,
 795 +                   skb->len - protoff - 4 * tcph->doff);
 796 +
 797 +               ctdata->mark = (ctdata->mark & ~connmark_mask) | n;
 798 +               ((struct sk_buff *)skb)->mark =
 799 +                       (skb->mark & ~packet_mask) ^ mark_seen;
 800 +       }
 801 +
 802 +       return (info->match_syn && ctdata->mark == mark_synscan) ||
 803 +              (info->match_cn && ctdata->mark == mark_cnscan) ||
 804 +              (info->match_gr && ctdata->mark == mark_grscan);
 805 +}
 806 +
 807 +static bool portscan_mt_check(const char *tablename, const void *entry,
 808 +    const struct xt_match *match, void *matchinfo, unsigned int hook_mask)
 809 +{
 810 +       const struct xt_portscan_match_info *info = matchinfo;
 811 +
 812 +       if ((info->match_stealth & ~1) || (info->match_syn & ~1) ||
 813 +           (info->match_cn & ~1) || (info->match_gr & ~1)) {
 814 +               printk(KERN_WARNING PFX "Invalid flags\n");
 815 +               return false;
 816 +       }
 817 +       return true;
 818 +}
 819 +
 820 +static struct xt_match portscan_mt_reg __read_mostly = {
 821 +       .name       = "portscan",
 822 +       .family     = AF_INET,
 823 +       .match      = portscan_mt,
 824 +       .checkentry = portscan_mt_check,
 825 +       .matchsize  = sizeof(struct xt_portscan_match_info),
 826 +       .proto      = IPPROTO_TCP,
 827 +       .me         = THIS_MODULE,
 828 +};
 829 +
 830 +static int __init portscan_mt_init(void)
 831 +{
 832 +       return xt_register_match(&portscan_mt_reg);
 833 +}
 834 +
 835 +static void __exit portscan_mt_exit(void)
 836 +{
 837 +       xt_unregister_match(&portscan_mt_reg);
 838 +       return;
 839 +}
 840 +
 841 +module_init(portscan_mt_init);
 842 +module_exit(portscan_mt_exit);
 843 +MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
 844 +MODULE_DESCRIPTION("netfilter \"portscan\" match");
 845 +MODULE_LICENSE("GPL");
 846 +MODULE_ALIAS("ipt_portscan");
 847 --- a/drivers/char/random.c
 848 +++ b/drivers/char/random.c
 849 @@ -1574,6 +1574,8 @@ __u32 secure_tcp_sequence_number(__be32
 850         return seq;
 851  }
 852
 853 +EXPORT_SYMBOL(secure_tcp_sequence_number);
 854 +
 855  /* Generate secure starting point for ephemeral IPV4 transport port search */
 856  u32 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport)
 857  {