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