iptables: remove CHAOS and TARPIT patches

SVN-Revision: 14447
master
Gabor Juhos 16 years ago
parent 8188638b49
commit 2b2541ebad
  1. 4
      package/iptables/Makefile
  2. 393
      package/iptables/patches/1.4.1.1/006-chaostables_0.8.patch
  3. 106
      package/iptables/patches/1.4.1.1/007-tarpit_support.patch

@ -20,7 +20,7 @@ endif
ifeq ($(CONFIG_LINUX_2_6),y)
PKG_VERSION:=1.4.1.1
PKG_RELEASE:=1
PKG_RELEASE:=2
PKG_MD5SUM:=723fa88d8a0915e184f99e03e9bf06cb
endif
@ -259,7 +259,7 @@ TARGET_CFLAGS += $(FPIC)
CONFIGURE_ARGS += \
--enable-devel \
--with-kernel="$(LINUX_DIR)" \
--with-xtlibdir=/usr/lib/iptables
--with-xtlibdir=/usr/lib/iptables
define Build/Compile
mkdir -p $(PKG_INSTALL_DIR)

@ -1,393 +0,0 @@
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",
+ XTABLES_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 = XTABLES_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 = XTABLES_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",
+ XTABLES_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 = XTABLES_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.

@ -1,106 +0,0 @@
Index: iptables-1.4.0/extensions/libxt_TARPIT.c
===================================================================
--- /dev/null
+++ iptables-1.4.0/extensions/libxt_TARPIT.c
@@ -0,0 +1,55 @@
+/* Shared library add-on to iptables to add TARPIT target support */
+#include <stdio.h>
+#include <getopt.h>
+
+#include <xtables.h>
+#include <linux/netfilter/x_tables.h>
+
+static void TARPIT_help(void)
+{
+ fputs(
+"TARPIT takes no options\n"
+"\n", stdout);
+}
+
+static struct option TARPIT_opts[] = {
+ { 0 }
+};
+
+static int TARPIT_parse(int c, char **argv, int invert, unsigned int *flags,
+ const void *entry, struct xt_entry_target **target)
+{
+ return 0;
+}
+
+static void TARPIT_final_check(unsigned int flags)
+{
+}
+
+static void TARPIT_print(const void *ip, const struct xt_entry_target *target,
+ int numeric)
+{
+}
+
+static void TARPIT_save(const void *ip, const struct xt_entry_target *target)
+{
+}
+
+static struct xtables_target tarpit_target = {
+ .family = AF_INET,
+ .name = "TARPIT",
+ .version = XTABLES_VERSION,
+ .size = XT_ALIGN(0),
+ .userspacesize = XT_ALIGN(0),
+ .help = TARPIT_help,
+ .parse = TARPIT_parse,
+ .final_check = TARPIT_final_check,
+ .print = TARPIT_print,
+ .save = TARPIT_save,
+ .extra_opts = TARPIT_opts
+};
+
+void _init(void)
+{
+ xtables_register_target(&tarpit_target);
+}
Index: iptables-1.4.0/extensions/libxt_TARPIT.man
===================================================================
--- /dev/null
+++ iptables-1.4.0/extensions/libxt_TARPIT.man
@@ -0,0 +1,34 @@
+Captures and holds incoming TCP connections using no local
+per-connection resources. Connections are accepted, but immediately
+switched to the persist state (0 byte window), in which the remote
+side stops sending data and asks to continue every 60-240 seconds.
+Attempts to close the connection are ignored, forcing the remote side
+to time out the connection in 12-24 minutes.
+
+This offers similar functionality to LaBrea
+<http://www.hackbusters.net/LaBrea/> but doesn't require dedicated
+hardware or IPs. Any TCP port that you would normally DROP or REJECT
+can instead become a tarpit.
+
+To tarpit connections to TCP port 80 destined for the current machine:
+.IP
+iptables -A INPUT -p tcp -m tcp --dport 80 -j TARPIT
+.P
+To significantly slow down Code Red/Nimda-style scans of unused address
+space, forward unused ip addresses to a Linux box not acting as a router
+(e.g. "ip route 10.0.0.0 255.0.0.0 ip.of.linux.box" on a Cisco), enable IP
+forwarding on the Linux box, and add:
+.IP
+iptables -A FORWARD -p tcp -j TARPIT
+.IP
+iptables -A FORWARD -j DROP
+.TP
+NOTE:
+If you use the conntrack module while you are using TARPIT, you should
+also use the NOTRACK target, or the kernel will unnecessarily allocate
+resources for each TARPITted connection. To TARPIT incoming
+connections to the standard IRC port while using conntrack, you could:
+.IP
+iptables -t raw -A PREROUTING -p tcp --dport 6667 -j NOTRACK
+.IP
+iptables -A INPUT -p tcp --dport 6667 -j TARPIT
Index: iptables-1.4.0/extensions/.TARPIT-testx
===================================================================
--- /dev/null
+++ iptables-1.4.0/extensions/.TARPIT-testx
@@ -0,0 +1,2 @@
+#! /bin/sh
+[ -f "$KERNEL_DIR/net/netfilter/xt_TARPIT.c" ] && echo "TARPIT"
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