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

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.