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openwrt/package/iptables/patches/1.4.0/006-chaostables_0.8.patch
2008-04-15 06:11:23 +00:00

394 lines
12 KiB
Diff

Index: iptables-1.4.0/extensions/.CHAOS-testx
===================================================================
--- /dev/null
+++ iptables-1.4.0/extensions/.CHAOS-testx
@@ -0,0 +1,3 @@
+#! /bin/sh
+
+[ -f "$KERNEL_DIR/include/linux/netfilter/xt_CHAOS.h" ] && echo "CHAOS"
Index: iptables-1.4.0/extensions/libxt_CHAOS.c
===================================================================
--- /dev/null
+++ iptables-1.4.0/extensions/libxt_CHAOS.c
@@ -0,0 +1,114 @@
+/*
+ * CHAOS target for iptables
+ * Copyright © CC Computer Consultants GmbH, 2006 - 2007
+ * Contact: Jan Engelhardt <jengelh@computergmbh.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License; either version
+ * 2 or 3 as published by the Free Software Foundation.
+ */
+#include <getopt.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <xtables.h>
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter/xt_CHAOS.h>
+
+enum {
+ F_DELUDE = 1 << 0,
+ F_TARPIT = 1 << 1,
+};
+
+static const struct option chaos_tg_opts[] = {
+ {.name = "delude", .has_arg = false, .val = 'd'},
+ {.name = "tarpit", .has_arg = false, .val = 't'},
+ {},
+};
+
+static void chaos_tg_help(void)
+{
+ printf(
+ "CHAOS target v%s options:\n"
+ " --delude Enable DELUDE processing for TCP\n"
+ " --tarpit Enable TARPIT processing for TCP\n",
+ IPTABLES_VERSION);
+ return;
+}
+
+static int chaos_tg_parse(int c, char **argv, int invert, unsigned int *flags,
+ const void *entry, struct xt_entry_target **target)
+{
+ struct xt_chaos_target_info *info = (void *)((*target)->data);
+ switch (c) {
+ case 'd':
+ info->variant = XTCHAOS_DELUDE;
+ *flags |= F_DELUDE;
+ return true;
+ case 't':
+ info->variant = XTCHAOS_TARPIT;
+ *flags |= F_TARPIT;
+ return true;
+ }
+ return false;
+}
+
+static void chaos_tg_check(unsigned int flags)
+{
+ if ((flags & (F_DELUDE | F_TARPIT)) == (F_DELUDE | F_TARPIT))
+ /* If flags == 0x03, both were specified, which should not be. */
+ exit_error(PARAMETER_PROBLEM,
+ "CHAOS: only one of --tarpit or --delude "
+ "may be specified");
+ return;
+}
+
+static void chaos_tg_print(const void *ip,
+ const struct xt_entry_target *target, int numeric)
+{
+ const struct xt_chaos_target_info *info = (const void *)target->data;
+ switch (info->variant) {
+ case XTCHAOS_DELUDE:
+ printf("DELUDE ");
+ break;
+ case XTCHAOS_TARPIT:
+ printf("TARPIT ");
+ break;
+ }
+ return;
+}
+
+static void chaos_tg_save(const void *ip, const struct xt_entry_target *target)
+{
+ const struct xt_chaos_target_info *info = (const void *)target->data;
+ switch (info->variant) {
+ case XTCHAOS_DELUDE:
+ printf("--delude ");
+ break;
+ case XTCHAOS_TARPIT:
+ printf("--tarpit ");
+ break;
+ }
+ return;
+}
+
+static struct xtables_target chaos_tg_reg = {
+ .version = IPTABLES_VERSION,
+ .name = "CHAOS",
+ .family = AF_INET,
+ .size = XT_ALIGN(sizeof(struct xt_chaos_target_info)),
+ .userspacesize = XT_ALIGN(sizeof(struct xt_chaos_target_info)),
+ .help = chaos_tg_help,
+ .parse = chaos_tg_parse,
+ .final_check = chaos_tg_check,
+ .print = chaos_tg_print,
+ .save = chaos_tg_save,
+ .extra_opts = chaos_tg_opts,
+};
+
+void _init(void)
+{
+ xtables_register_target(&chaos_tg_reg);
+ return;
+}
Index: iptables-1.4.0/extensions/libxt_CHAOS.man
===================================================================
--- /dev/null
+++ iptables-1.4.0/extensions/libxt_CHAOS.man
@@ -0,0 +1,18 @@
+Causes confusion on the other end by doing odd things with incoming packets.
+CHAOS will randomly reply (or not) with one of its configurable subtargets:
+.TP
+\fB--delude\fR
+Use the REJECT and DELUDE targets as a base to do a sudden or deferred
+connection reset, fooling some network scanners to return non-deterministic
+(randomly open/closed) results, and in case it is deemed open, it is actually
+closed/filtered.
+.TP
+\fB--tarpit\fR
+Use the REJECT and TARPIT target as a base to hold the connection until it
+times out. This consumes conntrack entries when connection tracking is loaded
+(which usually is on most machines), and routers inbetween you and the Internet
+may fail to do their connection tracking if they have to handle more
+connections than they can.
+.PP
+The randomness factor of not replying vs. replying can be set during load-time
+of the xt_CHAOS module or during runtime in /sys/modules/xt_CHAOS/parameters.
Index: iptables-1.4.0/extensions/.DELUDE-testx
===================================================================
--- /dev/null
+++ iptables-1.4.0/extensions/.DELUDE-testx
@@ -0,0 +1,3 @@
+#! /bin/sh
+
+[ -f "$KERNEL_DIR/net/netfilter/xt_DELUDE.c" ] && echo "DELUDE"
Index: iptables-1.4.0/extensions/libxt_DELUDE.c
===================================================================
--- /dev/null
+++ iptables-1.4.0/extensions/libxt_DELUDE.c
@@ -0,0 +1,49 @@
+/*
+ * DELUDE target for iptables
+ * Copyright © CC Computer Consultants GmbH, 2006 - 2007
+ * Contact: Jan Engelhardt <jengelh@computergmbh.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License; either version
+ * 2 or 3 as published by the Free Software Foundation.
+ */
+#include <getopt.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <xtables.h>
+#include <linux/netfilter/x_tables.h>
+
+static void delude_tg_help(void)
+{
+ printf("DELUDE takes no options\n");
+ return;
+}
+
+static int delude_tg_parse(int c, char **argv, int invert, unsigned int *flags,
+ const void *entry, struct xt_entry_target **target)
+{
+ return 0;
+}
+
+static void delude_tg_check(unsigned int flags)
+{
+ return;
+}
+
+static struct xtables_target delude_tg_reg = {
+ .version = IPTABLES_VERSION,
+ .name = "DELUDE",
+ .family = AF_INET,
+ .size = XT_ALIGN(0),
+ .userspacesize = XT_ALIGN(0),
+ .help = delude_tg_help,
+ .parse = delude_tg_parse,
+ .final_check = delude_tg_check,
+};
+
+void _init(void)
+{
+ xtables_register_target(&delude_tg_reg);
+ return;
+}
Index: iptables-1.4.0/extensions/libxt_DELUDE.man
===================================================================
--- /dev/null
+++ iptables-1.4.0/extensions/libxt_DELUDE.man
@@ -0,0 +1,4 @@
+The DELUDE target will reply to a SYN packet with SYN-ACK, and to all other
+packets with an RST. This will terminate the connection much like REJECT, but
+network scanners doing TCP half-open discovery can be spoofed to make them
+belive the port is open rather than closed/filtered.
Index: iptables-1.4.0/extensions/.portscan-testx
===================================================================
--- /dev/null
+++ iptables-1.4.0/extensions/.portscan-testx
@@ -0,0 +1,3 @@
+#! /bin/sh
+
+[ -f "$KERNEL_DIR/include/linux/netfilter/xt_portscan.h" ] && echo "portscan"
Index: iptables-1.4.0/extensions/libxt_portscan.c
===================================================================
--- /dev/null
+++ iptables-1.4.0/extensions/libxt_portscan.c
@@ -0,0 +1,127 @@
+/*
+ * portscan match for iptables
+ * Copyright © CC Computer Consultants GmbH, 2006 - 2007
+ * Contact: Jan Engelhardt <jengelh@computergmbh.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License; either version
+ * 2 or 3 as published by the Free Software Foundation.
+ */
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <getopt.h>
+
+#include <xtables.h>
+#include <iptables.h>
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter/xt_portscan.h>
+
+static const struct option portscan_mt_opts[] = {
+ {.name = "stealth", .has_arg = false, .val = 'x'},
+ {.name = "synscan", .has_arg = false, .val = 's'},
+ {.name = "cnscan", .has_arg = false, .val = 'c'},
+ {.name = "grscan", .has_arg = false, .val = 'g'},
+ {},
+};
+
+static void portscan_mt_help(void)
+{
+ printf(
+ "portscan match v%s options:\n"
+ "(Combining them will make them match by OR-logic)\n"
+ " --stealth Match TCP Stealth packets\n"
+ " --synscan Match TCP SYN scans\n"
+ " --cnscan Match TCP Connect scans\n"
+ " --grscan Match Banner Grabbing scans\n",
+ IPTABLES_VERSION);
+ return;
+}
+
+static int portscan_mt_parse(int c, char **argv, int invert,
+ unsigned int *flags, const void *entry, struct xt_entry_match **match)
+{
+ struct xt_portscan_match_info *info = (void *)((*match)->data);
+
+ switch (c) {
+ case 'c':
+ info->match_cn = true;
+ return true;
+ case 'g':
+ info->match_gr = true;
+ return true;
+ case 's':
+ info->match_syn = true;
+ return true;
+ case 'x':
+ info->match_stealth = true;
+ return true;
+ }
+ return false;
+}
+
+static void portscan_mt_check(unsigned int flags)
+{
+ return;
+}
+
+static void portscan_mt_print(const void *ip,
+ const struct xt_entry_match *match, int numeric)
+{
+ const struct xt_portscan_match_info *info = (const void *)(match->data);
+ const char *s = "";
+
+ printf("portscan ");
+ if (info->match_stealth) {
+ printf("STEALTH");
+ s = ",";
+ }
+ if (info->match_syn) {
+ printf("%sSYNSCAN", s);
+ s = ",";
+ }
+ if (info->match_cn) {
+ printf("%sCNSCAN", s);
+ s = ",";
+ }
+ if (info->match_gr)
+ printf("%sGRSCAN", s);
+ printf(" ");
+ return;
+}
+
+static void portscan_mt_save(const void *ip, const struct xt_entry_match *match)
+{
+ const struct xt_portscan_match_info *info = (const void *)(match->data);
+
+ if (info->match_stealth)
+ printf("--stealth ");
+ if (info->match_syn)
+ printf("--synscan ");
+ if (info->match_cn)
+ printf("--cnscan ");
+ if (info->match_gr)
+ printf("--grscan ");
+ return;
+}
+
+static struct xtables_match portscan_mt_reg = {
+ .version = IPTABLES_VERSION,
+ .name = "portscan",
+ .family = AF_INET,
+ .size = XT_ALIGN(sizeof(struct xt_portscan_match_info)),
+ .userspacesize = XT_ALIGN(sizeof(struct xt_portscan_match_info)),
+ .help = portscan_mt_help,
+ .parse = portscan_mt_parse,
+ .final_check = portscan_mt_check,
+ .print = portscan_mt_print,
+ .save = portscan_mt_save,
+ .extra_opts = portscan_mt_opts,
+};
+
+void _init(void)
+{
+ xtables_register_match(&portscan_mt_reg);
+ return;
+}
Index: iptables-1.4.0/extensions/libxt_portscan.man
===================================================================
--- /dev/null
+++ iptables-1.4.0/extensions/libxt_portscan.man
@@ -0,0 +1,27 @@
+Detects simple port scan attemps based upon the packet's contents. (This is
+different from other implementations, which also try to match the rate of new
+connections.) Note that an attempt is only discovered after it has been carried
+out, but this information can be used in conjunction with other rules to block
+the remote host's future connections. So this match module will match on the
+(probably) last packet the remote side will send to your machine.
+.TP
+\fB--stealth\fR
+Match if the packet did not belong to any known TCP connection
+(Stealth/FIN/XMAS/NULL scan).
+.TP
+\fB--synscan\fR
+Match if the connection was a TCP half-open discovery (SYN scan), i.e. the
+connection was torn down after the 2nd packet in the 3-way handshake.
+.TP
+\fB--cnscan\fR
+Match if the connection was a TCP full open discovery (connect scan), i.e. the
+connection was torn down after completion of the 3-way handshake.
+.TP
+\fB--grscan\fR
+Match if data in the connection only flew in the direction of the remote side,
+e.g. if the connection was terminated after a locally running daemon sent its
+identification. (e.g. openssh)
+.PP
+NOTE: Some clients (Windows XP for example) may do what looks like a SYN scan,
+so be advised to carefully use xt_portscan in conjunction with blocking rules,
+as it may lock out your very own internal network.