package/iptables/patches/1.4.0/006-chaostables_0.8.patch

   1 Index: iptables-1.4.0/extensions/.CHAOS-testx
   2 ===================================================================
   3 --- /dev/null
   4 +++ iptables-1.4.0/extensions/.CHAOS-testx
   5 @@ -0,0 +1,3 @@
   6 +#! /bin/sh
   7 +
   8 +[ -f "$KERNEL_DIR/include/linux/netfilter/xt_CHAOS.h" ] && echo "CHAOS"
   9 Index: iptables-1.4.0/extensions/libxt_CHAOS.c
  10 ===================================================================
  11 --- /dev/null
  12 +++ iptables-1.4.0/extensions/libxt_CHAOS.c
  13 @@ -0,0 +1,114 @@
  14 +/*
  15 + *     CHAOS target for iptables
  16 + *     Copyright © CC Computer Consultants GmbH, 2006 - 2007
  17 + *     Contact: Jan Engelhardt <jengelh@computergmbh.de>
  18 + *
  19 + *     This program is free software; you can redistribute it and/or modify
  20 + *     it under the terms of the GNU General Public License; either version
  21 + *     2 or 3 as published by the Free Software Foundation.
  22 + */
  23 +#include <getopt.h>
  24 +#include <stdbool.h>
  25 +#include <stdio.h>
  26 +#include <string.h>
  27 +
  28 +#include <xtables.h>
  29 +#include <linux/netfilter/x_tables.h>
  30 +#include <linux/netfilter/xt_CHAOS.h>
  31 +
  32 +enum {
  33 +       F_DELUDE = 1 << 0,
  34 +       F_TARPIT = 1 << 1,
  35 +};
  36 +
  37 +static const struct option chaos_tg_opts[] = {
  38 +       {.name = "delude", .has_arg = false, .val = 'd'},
  39 +       {.name = "tarpit", .has_arg = false, .val = 't'},
  40 +       {},
  41 +};
  42 +
  43 +static void chaos_tg_help(void)
  44 +{
  45 +       printf(
  46 +               "CHAOS target v%s options:\n"
  47 +               "  --delude     Enable DELUDE processing for TCP\n"
  48 +               "  --tarpit     Enable TARPIT processing for TCP\n",
  49 +               IPTABLES_VERSION);
  50 +       return;
  51 +}
  52 +
  53 +static int chaos_tg_parse(int c, char **argv, int invert, unsigned int *flags,
  54 +    const void *entry, struct xt_entry_target **target)
  55 +{
  56 +       struct xt_chaos_target_info *info = (void *)((*target)->data);
  57 +       switch (c) {
  58 +               case 'd':
  59 +                       info->variant = XTCHAOS_DELUDE;
  60 +                       *flags |= F_DELUDE;
  61 +                       return true;
  62 +               case 't':
  63 +                       info->variant = XTCHAOS_TARPIT;
  64 +                       *flags |= F_TARPIT;
  65 +                       return true;
  66 +       }
  67 +       return false;
  68 +}
  69 +
  70 +static void chaos_tg_check(unsigned int flags)
  71 +{
  72 +       if ((flags & (F_DELUDE | F_TARPIT)) == (F_DELUDE | F_TARPIT))
  73 +               /* If flags == 0x03, both were specified, which should not be. */
  74 +               exit_error(PARAMETER_PROBLEM,
  75 +                          "CHAOS: only one of --tarpit or --delude "
  76 +                          "may be specified");
  77 +       return;
  78 +}
  79 +
  80 +static void chaos_tg_print(const void *ip,
  81 +    const struct xt_entry_target *target, int numeric)
  82 +{
  83 +       const struct xt_chaos_target_info *info = (const void *)target->data;
  84 +       switch (info->variant) {
  85 +               case XTCHAOS_DELUDE:
  86 +                       printf("DELUDE ");
  87 +                       break;
  88 +               case XTCHAOS_TARPIT:
  89 +                       printf("TARPIT ");
  90 +                       break;
  91 +       }
  92 +       return;
  93 +}
  94 +
  95 +static void chaos_tg_save(const void *ip, const struct xt_entry_target *target)
  96 +{
  97 +       const struct xt_chaos_target_info *info = (const void *)target->data;
  98 +       switch (info->variant) {
  99 +               case XTCHAOS_DELUDE:
 100 +                       printf("--delude ");
 101 +                       break;
 102 +               case XTCHAOS_TARPIT:
 103 +                       printf("--tarpit ");
 104 +                       break;
 105 +       }
 106 +       return;
 107 +}
 108 +
 109 +static struct xtables_target chaos_tg_reg = {
 110 +       .version       = IPTABLES_VERSION,
 111 +       .name          = "CHAOS",
 112 +       .family        = AF_INET,
 113 +       .size          = XT_ALIGN(sizeof(struct xt_chaos_target_info)),
 114 +       .userspacesize = XT_ALIGN(sizeof(struct xt_chaos_target_info)),
 115 +       .help          = chaos_tg_help,
 116 +       .parse         = chaos_tg_parse,
 117 +       .final_check   = chaos_tg_check,
 118 +       .print         = chaos_tg_print,
 119 +       .save          = chaos_tg_save,
 120 +       .extra_opts    = chaos_tg_opts,
 121 +};
 122 +
 123 +void _init(void)
 124 +{
 125 +       xtables_register_target(&chaos_tg_reg);
 126 +       return;
 127 +}
 128 Index: iptables-1.4.0/extensions/libxt_CHAOS.man
 129 ===================================================================
 130 --- /dev/null
 131 +++ iptables-1.4.0/extensions/libxt_CHAOS.man
 132 @@ -0,0 +1,18 @@
 133 +Causes confusion on the other end by doing odd things with incoming packets.
 134 +CHAOS will randomly reply (or not) with one of its configurable subtargets:
 135 +.TP
 136 +\fB--delude\fR
 137 +Use the REJECT and DELUDE targets as a base to do a sudden or deferred
 138 +connection reset, fooling some network scanners to return non-deterministic
 139 +(randomly open/closed) results, and in case it is deemed open, it is actually
 140 +closed/filtered.
 141 +.TP
 142 +\fB--tarpit\fR
 143 +Use the REJECT and TARPIT target as a base to hold the connection until it
 144 +times out. This consumes conntrack entries when connection tracking is loaded
 145 +(which usually is on most machines), and routers inbetween you and the Internet
 146 +may fail to do their connection tracking if they have to handle more
 147 +connections than they can.
 148 +.PP
 149 +The randomness factor of not replying vs. replying can be set during load-time
 150 +of the xt_CHAOS module or during runtime in /sys/modules/xt_CHAOS/parameters.
 151 Index: iptables-1.4.0/extensions/.DELUDE-testx
 152 ===================================================================
 153 --- /dev/null
 154 +++ iptables-1.4.0/extensions/.DELUDE-testx
 155 @@ -0,0 +1,3 @@
 156 +#! /bin/sh
 157 +
 158 +[ -f "$KERNEL_DIR/net/netfilter/xt_DELUDE.c" ] && echo "DELUDE"
 159 Index: iptables-1.4.0/extensions/libxt_DELUDE.c
 160 ===================================================================
 161 --- /dev/null
 162 +++ iptables-1.4.0/extensions/libxt_DELUDE.c
 163 @@ -0,0 +1,49 @@
 164 +/*
 165 + *     DELUDE target for iptables
 166 + *     Copyright © CC Computer Consultants GmbH, 2006 - 2007
 167 + *     Contact: Jan Engelhardt <jengelh@computergmbh.de>
 168 + *
 169 + *     This program is free software; you can redistribute it and/or modify
 170 + *     it under the terms of the GNU General Public License; either version
 171 + *     2 or 3 as published by the Free Software Foundation.
 172 + */
 173 +#include <getopt.h>
 174 +#include <stdio.h>
 175 +#include <string.h>
 176 +
 177 +#include <xtables.h>
 178 +#include <linux/netfilter/x_tables.h>
 179 +
 180 +static void delude_tg_help(void)
 181 +{
 182 +       printf("DELUDE takes no options\n");
 183 +       return;
 184 +}
 185 +
 186 +static int delude_tg_parse(int c, char **argv, int invert, unsigned int *flags,
 187 +    const void *entry, struct xt_entry_target **target)
 188 +{
 189 +       return 0;
 190 +}
 191 +
 192 +static void delude_tg_check(unsigned int flags)
 193 +{
 194 +       return;
 195 +}
 196 +
 197 +static struct xtables_target delude_tg_reg = {
 198 +       .version       = IPTABLES_VERSION,
 199 +       .name          = "DELUDE",
 200 +       .family        = AF_INET,
 201 +       .size          = XT_ALIGN(0),
 202 +       .userspacesize = XT_ALIGN(0),
 203 +       .help          = delude_tg_help,
 204 +       .parse         = delude_tg_parse,
 205 +       .final_check   = delude_tg_check,
 206 +};
 207 +
 208 +void _init(void)
 209 +{
 210 +       xtables_register_target(&delude_tg_reg);
 211 +       return;
 212 +}
 213 Index: iptables-1.4.0/extensions/libxt_DELUDE.man
 214 ===================================================================
 215 --- /dev/null
 216 +++ iptables-1.4.0/extensions/libxt_DELUDE.man
 217 @@ -0,0 +1,4 @@
 218 +The DELUDE target will reply to a SYN packet with SYN-ACK, and to all other
 219 +packets with an RST. This will terminate the connection much like REJECT, but
 220 +network scanners doing TCP half-open discovery can be spoofed to make them
 221 +belive the port is open rather than closed/filtered.
 222 Index: iptables-1.4.0/extensions/.portscan-testx
 223 ===================================================================
 224 --- /dev/null
 225 +++ iptables-1.4.0/extensions/.portscan-testx
 226 @@ -0,0 +1,3 @@
 227 +#! /bin/sh
 228 +
 229 +[ -f "$KERNEL_DIR/include/linux/netfilter/xt_portscan.h" ] && echo "portscan"
 230 Index: iptables-1.4.0/extensions/libxt_portscan.c
 231 ===================================================================
 232 --- /dev/null
 233 +++ iptables-1.4.0/extensions/libxt_portscan.c
 234 @@ -0,0 +1,127 @@
 235 +/*
 236 + *     portscan match for iptables
 237 + *     Copyright © CC Computer Consultants GmbH, 2006 - 2007
 238 + *     Contact: Jan Engelhardt <jengelh@computergmbh.de>
 239 + *
 240 + *     This program is free software; you can redistribute it and/or modify
 241 + *     it under the terms of the GNU General Public License; either version
 242 + *     2 or 3 as published by the Free Software Foundation.
 243 + */
 244 +#include <stdbool.h>
 245 +#include <stdio.h>
 246 +#include <string.h>
 247 +#include <stdlib.h>
 248 +#include <getopt.h>
 249 +
 250 +#include <xtables.h>
 251 +#include <iptables.h>
 252 +#include <linux/netfilter/x_tables.h>
 253 +#include <linux/netfilter/xt_portscan.h>
 254 +
 255 +static const struct option portscan_mt_opts[] = {
 256 +       {.name = "stealth", .has_arg = false, .val = 'x'},
 257 +       {.name = "synscan", .has_arg = false, .val = 's'},
 258 +       {.name = "cnscan",  .has_arg = false, .val = 'c'},
 259 +       {.name = "grscan",  .has_arg = false, .val = 'g'},
 260 +       {},
 261 +};
 262 +
 263 +static void portscan_mt_help(void)
 264 +{
 265 +       printf(
 266 +               "portscan match v%s options:\n"
 267 +               "(Combining them will make them match by OR-logic)\n"
 268 +               "  --stealth    Match TCP Stealth packets\n"
 269 +               "  --synscan    Match TCP SYN scans\n"
 270 +               "  --cnscan     Match TCP Connect scans\n"
 271 +               "  --grscan     Match Banner Grabbing scans\n",
 272 +               IPTABLES_VERSION);
 273 +       return;
 274 +}
 275 +
 276 +static int portscan_mt_parse(int c, char **argv, int invert,
 277 +    unsigned int *flags, const void *entry, struct xt_entry_match **match)
 278 +{
 279 +       struct xt_portscan_match_info *info = (void *)((*match)->data);
 280 +
 281 +       switch (c) {
 282 +               case 'c':
 283 +                       info->match_cn = true;
 284 +                       return true;
 285 +               case 'g':
 286 +                       info->match_gr = true;
 287 +                       return true;
 288 +               case 's':
 289 +                       info->match_syn = true;
 290 +                       return true;
 291 +               case 'x':
 292 +                       info->match_stealth = true;
 293 +                       return true;
 294 +       }
 295 +       return false;
 296 +}
 297 +
 298 +static void portscan_mt_check(unsigned int flags)
 299 +{
 300 +       return;
 301 +}
 302 +
 303 +static void portscan_mt_print(const void *ip,
 304 +    const struct xt_entry_match *match, int numeric)
 305 +{
 306 +       const struct xt_portscan_match_info *info = (const void *)(match->data);
 307 +       const char *s = "";
 308 +
 309 +       printf("portscan ");
 310 +       if (info->match_stealth) {
 311 +               printf("STEALTH");
 312 +               s = ",";
 313 +       }
 314 +       if (info->match_syn) {
 315 +               printf("%sSYNSCAN", s);
 316 +               s = ",";
 317 +       }
 318 +       if (info->match_cn) {
 319 +               printf("%sCNSCAN", s);
 320 +               s = ",";
 321 +       }
 322 +       if (info->match_gr)
 323 +               printf("%sGRSCAN", s);
 324 +       printf(" ");
 325 +       return;
 326 +}
 327 +
 328 +static void portscan_mt_save(const void *ip, const struct xt_entry_match *match)
 329 +{
 330 +       const struct xt_portscan_match_info *info = (const void *)(match->data);
 331 +
 332 +       if (info->match_stealth)
 333 +               printf("--stealth ");
 334 +       if (info->match_syn)
 335 +               printf("--synscan ");
 336 +       if (info->match_cn)
 337 +               printf("--cnscan ");
 338 +       if (info->match_gr)
 339 +               printf("--grscan ");
 340 +       return;
 341 +}
 342 +
 343 +static struct xtables_match portscan_mt_reg = {
 344 +       .version       = IPTABLES_VERSION,
 345 +       .name          = "portscan",
 346 +       .family        = AF_INET,
 347 +       .size          = XT_ALIGN(sizeof(struct xt_portscan_match_info)),
 348 +       .userspacesize = XT_ALIGN(sizeof(struct xt_portscan_match_info)),
 349 +       .help          = portscan_mt_help,
 350 +       .parse         = portscan_mt_parse,
 351 +       .final_check   = portscan_mt_check,
 352 +       .print         = portscan_mt_print,
 353 +       .save          = portscan_mt_save,
 354 +       .extra_opts    = portscan_mt_opts,
 355 +};
 356 +
 357 +void _init(void)
 358 +{
 359 +       xtables_register_match(&portscan_mt_reg);
 360 +       return;
 361 +}
 362 Index: iptables-1.4.0/extensions/libxt_portscan.man
 363 ===================================================================
 364 --- /dev/null
 365 +++ iptables-1.4.0/extensions/libxt_portscan.man
 366 @@ -0,0 +1,27 @@
 367 +Detects simple port scan attemps based upon the packet's contents. (This is
 368 +different from other implementations, which also try to match the rate of new
 369 +connections.) Note that an attempt is only discovered after it has been carried
 370 +out, but this information can be used in conjunction with other rules to block
 371 +the remote host's future connections. So this match module will match on the
 372 +(probably) last packet the remote side will send to your machine.
 373 +.TP
 374 +\fB--stealth\fR
 375 +Match if the packet did not belong to any known TCP connection
 376 +(Stealth/FIN/XMAS/NULL scan).
 377 +.TP
 378 +\fB--synscan\fR
 379 +Match if the connection was a TCP half-open discovery (SYN scan), i.e. the
 380 +connection was torn down after the 2nd packet in the 3-way handshake.
 381 +.TP
 382 +\fB--cnscan\fR
 383 +Match if the connection was a TCP full open discovery (connect scan), i.e. the
 384 +connection was torn down after completion of the 3-way handshake.
 385 +.TP
 386 +\fB--grscan\fR
 387 +Match if data in the connection only flew in the direction of the remote side,
 388 +e.g. if the connection was terminated after a locally running daemon sent its
 389 +identification. (e.g. openssh)
 390 +.PP
 391 +NOTE: Some clients (Windows XP for example) may do what looks like a SYN scan,
 392 +so be advised to carefully use xt_portscan in conjunction with blocking rules,
 393 +as it may lock out your very own internal network.