# CONFIG_NETFILTER_XT_MATCH_STATISTIC is not set
CONFIG_NETFILTER_XT_MATCH_STRING=m
CONFIG_NETFILTER_XT_MATCH_TCPMSS=y
-CONFIG_NETFILTER_XT_TARGET_CHAOS=m
CONFIG_NETFILTER_XT_TARGET_CLASSIFY=m
CONFIG_NETFILTER_XT_TARGET_CONNMARK=m
-CONFIG_NETFILTER_XT_TARGET_DELUDE=m
CONFIG_NETFILTER_XT_TARGET_DSCP=m
CONFIG_NETFILTER_XT_TARGET_MARK=m
CONFIG_NETFILTER_XT_TARGET_NFLOG=m
CONFIG_NETFILTER_XT_MATCH_STRING=m
CONFIG_NETFILTER_XT_MATCH_TCPMSS=m
CONFIG_NETFILTER_XT_MATCH_U32=m
-CONFIG_NETFILTER_XT_TARGET_CHAOS=m
CONFIG_NETFILTER_XT_TARGET_CLASSIFY=m
CONFIG_NETFILTER_XT_TARGET_CONNMARK=m
-CONFIG_NETFILTER_XT_TARGET_DELUDE=m
CONFIG_NETFILTER_XT_TARGET_DSCP=m
CONFIG_NETFILTER_XT_TARGET_MARK=m
CONFIG_NETFILTER_XT_TARGET_NFLOG=m
CONFIG_NETFILTER_XT_TARGET_NFQUEUE=m
CONFIG_NETFILTER_XT_TARGET_NOTRACK=m
-CONFIG_NETFILTER_XT_TARGET_TARPIT=m
CONFIG_NETFILTER_XT_TARGET_TCPMSS=m
CONFIG_NETFILTER_XT_TARGET_TRACE=m
# CONFIG_NETPOLL is not set
CONFIG_NETFILTER_XT_MATCH_STRING=m
CONFIG_NETFILTER_XT_MATCH_TCPMSS=m
CONFIG_NETFILTER_XT_MATCH_U32=m
-CONFIG_NETFILTER_XT_TARGET_CHAOS=m
CONFIG_NETFILTER_XT_TARGET_CLASSIFY=m
CONFIG_NETFILTER_XT_TARGET_CONNMARK=m
-CONFIG_NETFILTER_XT_TARGET_DELUDE=m
CONFIG_NETFILTER_XT_TARGET_DSCP=m
CONFIG_NETFILTER_XT_TARGET_MARK=m
CONFIG_NETFILTER_XT_TARGET_NFLOG=m
CONFIG_NETFILTER_XT_TARGET_NFQUEUE=m
CONFIG_NETFILTER_XT_TARGET_NOTRACK=m
-CONFIG_NETFILTER_XT_TARGET_TARPIT=m
CONFIG_NETFILTER_XT_TARGET_TCPMSS=m
CONFIG_NETFILTER_XT_TARGET_TRACE=m
# CONFIG_NETPOLL is not set
CONFIG_NETFILTER_XT_MATCH_STRING=m
CONFIG_NETFILTER_XT_MATCH_TCPMSS=m
CONFIG_NETFILTER_XT_MATCH_U32=m
-CONFIG_NETFILTER_XT_TARGET_CHAOS=m
CONFIG_NETFILTER_XT_TARGET_CLASSIFY=m
CONFIG_NETFILTER_XT_TARGET_CONNMARK=m
-CONFIG_NETFILTER_XT_TARGET_DELUDE=m
CONFIG_NETFILTER_XT_TARGET_DSCP=m
CONFIG_NETFILTER_XT_TARGET_MARK=m
CONFIG_NETFILTER_XT_TARGET_NFLOG=m
CONFIG_NETFILTER_XT_TARGET_NFQUEUE=m
CONFIG_NETFILTER_XT_TARGET_NOTRACK=m
CONFIG_NETFILTER_XT_TARGET_RATEEST=m
-CONFIG_NETFILTER_XT_TARGET_TARPIT=m
CONFIG_NETFILTER_XT_TARGET_TCPMSS=m
CONFIG_NETFILTER_XT_TARGET_TCPOPTSTRIP=m
CONFIG_NETFILTER_XT_TARGET_TRACE=m
CONFIG_NETFILTER_XT_MATCH_STRING=m
CONFIG_NETFILTER_XT_MATCH_TCPMSS=m
CONFIG_NETFILTER_XT_MATCH_U32=m
-CONFIG_NETFILTER_XT_TARGET_CHAOS=m
CONFIG_NETFILTER_XT_TARGET_CLASSIFY=m
CONFIG_NETFILTER_XT_TARGET_CONNMARK=m
-CONFIG_NETFILTER_XT_TARGET_DELUDE=m
CONFIG_NETFILTER_XT_TARGET_DSCP=m
CONFIG_NETFILTER_XT_TARGET_MARK=m
CONFIG_NETFILTER_XT_TARGET_NFLOG=m
CONFIG_NETFILTER_XT_TARGET_NFQUEUE=m
CONFIG_NETFILTER_XT_TARGET_NOTRACK=m
CONFIG_NETFILTER_XT_TARGET_RATEEST=m
-CONFIG_NETFILTER_XT_TARGET_TARPIT=m
CONFIG_NETFILTER_XT_TARGET_TCPMSS=m
CONFIG_NETFILTER_XT_TARGET_TCPOPTSTRIP=m
CONFIG_NETFILTER_XT_TARGET_TRACE=m
CONFIG_NETFILTER_XT_MATCH_TCPMSS=m
CONFIG_NETFILTER_XT_MATCH_TIME=m
CONFIG_NETFILTER_XT_MATCH_U32=m
-CONFIG_NETFILTER_XT_TARGET_CHAOS=m
CONFIG_NETFILTER_XT_TARGET_CLASSIFY=m
CONFIG_NETFILTER_XT_TARGET_CONNMARK=m
-CONFIG_NETFILTER_XT_TARGET_DELUDE=m
CONFIG_NETFILTER_XT_TARGET_DSCP=m
CONFIG_NETFILTER_XT_TARGET_MARK=m
CONFIG_NETFILTER_XT_TARGET_NFLOG=m
CONFIG_NETFILTER_XT_TARGET_NFQUEUE=m
CONFIG_NETFILTER_XT_TARGET_NOTRACK=m
CONFIG_NETFILTER_XT_TARGET_RATEEST=m
-CONFIG_NETFILTER_XT_TARGET_TARPIT=m
CONFIG_NETFILTER_XT_TARGET_TCPMSS=m
CONFIG_NETFILTER_XT_TARGET_TCPOPTSTRIP=m
CONFIG_NETFILTER_XT_TARGET_TRACE=m
CONFIG_NETFILTER_XT_MATCH_TCPMSS=m
CONFIG_NETFILTER_XT_MATCH_TIME=m
CONFIG_NETFILTER_XT_MATCH_U32=m
-CONFIG_NETFILTER_XT_TARGET_CHAOS=m
CONFIG_NETFILTER_XT_TARGET_CLASSIFY=m
CONFIG_NETFILTER_XT_TARGET_CONNMARK=m
-CONFIG_NETFILTER_XT_TARGET_DELUDE=m
CONFIG_NETFILTER_XT_TARGET_DSCP=m
CONFIG_NETFILTER_XT_TARGET_MARK=m
CONFIG_NETFILTER_XT_TARGET_NFLOG=m
CONFIG_NETFILTER_XT_TARGET_NFQUEUE=m
CONFIG_NETFILTER_XT_TARGET_NOTRACK=m
CONFIG_NETFILTER_XT_TARGET_RATEEST=m
-CONFIG_NETFILTER_XT_TARGET_TARPIT=m
CONFIG_NETFILTER_XT_TARGET_TCPMSS=m
CONFIG_NETFILTER_XT_TARGET_TCPOPTSTRIP=m
CONFIG_NETFILTER_XT_TARGET_TRACE=m
+++ /dev/null
---- a/include/linux/netfilter/Kbuild
-+++ b/include/linux/netfilter/Kbuild
-@@ -3,6 +3,7 @@ header-y += nf_conntrack_tuple_common.h
- header-y += nfnetlink_conntrack.h
- header-y += nfnetlink_log.h
- header-y += nfnetlink_queue.h
-+header-y += xt_CHAOS.h
- header-y += xt_CLASSIFY.h
- header-y += xt_comment.h
- header-y += xt_connbytes.h
---- /dev/null
-+++ b/include/linux/netfilter/oot_conntrack.h
-@@ -0,0 +1,5 @@
-+#if defined(CONFIG_IP_NF_CONNTRACK) || defined(CONFIG_IP_NF_CONNTRACK_MODULE)
-+# include <linux/netfilter_ipv4/ip_conntrack.h>
-+#else /* linux-2.6.20+ */
-+# include <net/netfilter/nf_nat_rule.h>
-+#endif
---- /dev/null
-+++ b/include/linux/netfilter/oot_trans.h
-@@ -0,0 +1,14 @@
-+/* Out of tree workarounds */
-+#include <linux/version.h>
-+#if LINUX_VERSION_CODE <= KERNEL_VERSION(2, 6, 18)
-+# define HAVE_MATCHINFOSIZE 1
-+# define HAVE_TARGUSERINFO 1
-+# define HAVE_TARGINFOSIZE 1
-+#endif
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 20)
-+# define nfmark mark
-+#endif
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 21)
-+# define tcp_v4_check(tcph, tcph_sz, s, d, csp) \
-+ tcp_v4_check((tcph_sz), (s), (d), (csp))
-+#endif
---- /dev/null
-+++ b/include/linux/netfilter/xt_CHAOS.h
-@@ -0,0 +1,14 @@
-+#ifndef _LINUX_NETFILTER_XT_CHAOS_H
-+#define _LINUX_NETFILTER_XT_CHAOS_H 1
-+
-+enum xt_chaos_target_variant {
-+ XTCHAOS_NORMAL,
-+ XTCHAOS_TARPIT,
-+ XTCHAOS_DELUDE,
-+};
-+
-+struct xt_chaos_target_info {
-+ uint8_t variant;
-+};
-+
-+#endif /* _LINUX_NETFILTER_XT_CHAOS_H */
---- /dev/null
-+++ b/include/linux/netfilter/xt_portscan.h
-@@ -0,0 +1,8 @@
-+#ifndef _LINUX_NETFILTER_XT_PORTSCAN_H
-+#define _LINUX_NETFILTER_XT_PORTSCAN_H 1
-+
-+struct xt_portscan_match_info {
-+ uint8_t match_stealth, match_syn, match_cn, match_gr;
-+};
-+
-+#endif /* _LINUX_NETFILTER_XT_PORTSCAN_H */
---- /dev/null
-+++ b/net/netfilter/find_match.c
-@@ -0,0 +1,39 @@
-+/*
-+ xt_request_find_match
-+ by Jan Engelhardt <jengelh [at] gmx de>, 2006 - 2007
-+
-+ Based upon linux-2.6.18.5/net/netfilter/x_tables.c:
-+ Copyright (C) 2006-2006 Harald Welte <laforge@netfilter.org>
-+ This program is free software; you can redistribute it and/or modify
-+ it under the terms of the GNU General Public License version 2 as
-+ published by the Free Software Foundation.
-+*/
-+#include <linux/err.h>
-+#include <linux/netfilter_arp.h>
-+#include <linux/socket.h>
-+#include <linux/netfilter/x_tables.h>
-+
-+/*
-+ * Yeah this code is sub-optimal, but the function is missing in
-+ * mainline so far. -jengelh
-+ */
-+static struct xt_match *xt_request_find_match_lo(int af, const char *name,
-+ u8 revision)
-+{
-+ static const char *const xt_prefix[] = {
-+ [AF_INET] = "ip",
-+ [AF_INET6] = "ip6",
-+ [NF_ARP] = "arp",
-+ };
-+ struct xt_match *match;
-+
-+ match = try_then_request_module(xt_find_match(af, name, revision),
-+ "%st_%s", xt_prefix[af], name);
-+ if (IS_ERR(match) || match == NULL)
-+ return NULL;
-+
-+ return match;
-+}
-+
-+/* In case it goes into mainline, let this out-of-tree package compile */
-+#define xt_request_find_match xt_request_find_match_lo
---- a/net/netfilter/Kconfig
-+++ b/net/netfilter/Kconfig
-@@ -287,6 +287,14 @@ config NETFILTER_XTABLES
-
- # alphabetically ordered list of targets
-
-+config NETFILTER_XT_TARGET_CHAOS
-+ tristate '"CHAOS" target support'
-+ depends on NETFILTER_XTABLES
-+ help
-+ This option adds a `CHAOS' target.
-+
-+ To compile it as a module, choose M here. If unsure, say N.
-+
- config NETFILTER_XT_TARGET_CLASSIFY
- tristate '"CLASSIFY" target support'
- depends on NETFILTER_XTABLES
-@@ -315,6 +323,14 @@ config NETFILTER_XT_TARGET_CONNMARK
- <file:Documentation/modules.txt>. The module will be called
- ipt_CONNMARK.o. If unsure, say `N'.
-
-+config NETFILTER_XT_TARGET_DELUDE
-+ tristate '"DELUDE" target support'
-+ depends on NETFILTER_XTABLES
-+ help
-+ This option adds a `DELUDE' target.
-+
-+ To compile it as a module, choose M here. If unsure, say N.
-+
- config NETFILTER_XT_TARGET_DSCP
- tristate '"DSCP" target support'
- depends on NETFILTER_XTABLES
-@@ -563,6 +579,14 @@ config NETFILTER_XT_MATCH_POLICY
-
- To compile it as a module, choose M here. If unsure, say N.
-
-+config NETFILTER_XT_MATCH_PORTSCAN
-+ tristate '"portscan" match support'
-+ depends on NETFILTER_XTABLES
-+ help
-+ This option adds a 'portscan' match support.
-+
-+ To compile it as a module, choose M here. If unsure, say N.
-+
- config NETFILTER_XT_MATCH_MULTIPORT
- tristate "Multiple port match support"
- depends on NETFILTER_XTABLES
---- a/net/netfilter/Makefile
-+++ b/net/netfilter/Makefile
-@@ -47,6 +47,8 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_NOTRACK
- obj-$(CONFIG_NETFILTER_XT_TARGET_SECMARK) += xt_SECMARK.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_TCPMSS) += xt_TCPMSS.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_CONNSECMARK) += xt_CONNSECMARK.o
-+obj-$(CONFIG_NETFILTER_XT_TARGET_CHAOS) += xt_CHAOS.o
-+obj-$(CONFIG_NETFILTER_XT_TARGET_DELUDE) += xt_DELUDE.o
-
- # matches
- obj-$(CONFIG_NETFILTER_XT_MATCH_COMMENT) += xt_comment.o
-@@ -74,3 +76,4 @@ obj-$(CONFIG_NETFILTER_XT_MATCH_STRING)
- obj-$(CONFIG_NETFILTER_XT_MATCH_TCPMSS) += xt_tcpmss.o
- obj-$(CONFIG_NETFILTER_XT_MATCH_PHYSDEV) += xt_physdev.o
- obj-$(CONFIG_NETFILTER_XT_MATCH_HASHLIMIT) += xt_hashlimit.o
-+obj-$(CONFIG_NETFILTER_XT_MATCH_PORTSCAN) += xt_portscan.o
---- /dev/null
-+++ b/net/netfilter/xt_CHAOS.c
-@@ -0,0 +1,200 @@
-+/*
-+ * CHAOS target for netfilter
-+ * 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 <linux/icmp.h>
-+#include <linux/in.h>
-+#include <linux/ip.h>
-+#include <linux/module.h>
-+#include <linux/skbuff.h>
-+#include <linux/stat.h>
-+#include <linux/netfilter/x_tables.h>
-+#include <linux/netfilter/xt_tcpudp.h>
-+#include <linux/netfilter_ipv4/ipt_REJECT.h>
-+#include <net/ip.h>
-+#if defined(_LOCAL)
-+# include "xt_CHAOS.h"
-+# include "find_match.c"
-+#elif defined(CONFIG_NETFILTER_XT_TARGET_CHAOS) || \
-+ defined(CONFIG_NETFILTER_XT_TARGET_CHAOS_MODULE)
-+# include <linux/netfilter/xt_CHAOS.h>
-+# include "find_match.c"
-+#else
-+# include "xt_CHAOS.h"
-+# include "find_match.c"
-+#endif
-+#define PFX KBUILD_MODNAME ": "
-+
-+/* Module parameters */
-+static unsigned int reject_percentage = ~0U * .01;
-+static unsigned int delude_percentage = ~0U * .0101;
-+module_param(reject_percentage, uint, S_IRUGO | S_IWUSR);
-+module_param(delude_percentage, uint, S_IRUGO | S_IWUSR);
-+
-+/* References to other matches/targets */
-+static struct xt_match *xm_tcp;
-+static struct xt_target *xt_delude, *xt_reject, *xt_tarpit;
-+
-+static int have_delude, have_tarpit;
-+
-+/* Static data for other matches/targets */
-+static const struct ipt_reject_info reject_params = {
-+ .with = ICMP_HOST_UNREACH,
-+};
-+
-+static const struct xt_tcp tcp_params = {
-+ .spts = {0, ~0},
-+ .dpts = {0, ~0},
-+};
-+
-+/* CHAOS functions */
-+static void xt_chaos_total(const struct xt_chaos_target_info *info,
-+ struct sk_buff **pskb, const struct net_device *in,
-+ const struct net_device *out, unsigned int hooknum)
-+{
-+ const struct iphdr *iph = ip_hdr(*pskb);
-+ const int protoff = 4 * iph->ihl;
-+ const int offset = ntohs(iph->frag_off) & IP_OFFSET;
-+ const struct xt_target *destiny;
-+ int hotdrop = 0, ret;
-+
-+ ret = xm_tcp->match(*pskb, in, out, xm_tcp, &tcp_params,
-+ offset, protoff, &hotdrop);
-+ if (!ret || hotdrop || (unsigned int)net_random() > delude_percentage)
-+ return;
-+
-+ destiny = (info->variant == XTCHAOS_TARPIT) ? xt_tarpit : xt_delude;
-+ destiny->target(pskb, in, out, hooknum, destiny, NULL);
-+ return;
-+}
-+
-+static unsigned int chaos_tg(struct sk_buff **pskb,
-+ const struct net_device *in, const struct net_device *out,
-+ unsigned int hooknum, const struct xt_target *target, const void *targinfo)
-+{
-+ /*
-+ * Equivalent to:
-+ * -A chaos -m statistic --mode random --probability \
-+ * $reject_percentage -j REJECT --reject-with host-unreach;
-+ * -A chaos -p tcp -m statistic --mode random --probability \
-+ * $delude_percentage -j DELUDE;
-+ * -A chaos -j DROP;
-+ */
-+ const struct xt_chaos_target_info *info = targinfo;
-+ const struct iphdr *iph = ip_hdr(*pskb);
-+
-+ if ((unsigned int)net_random() <= reject_percentage)
-+ return xt_reject->target(pskb, in, out, hooknum, target,
-+ &reject_params);
-+
-+ /* TARPIT/DELUDE may not be called from the OUTPUT chain */
-+ if (iph->protocol == IPPROTO_TCP &&
-+ info->variant != XTCHAOS_NORMAL && hooknum != NF_IP_LOCAL_OUT)
-+ xt_chaos_total(info, pskb, in, out, hooknum);
-+
-+ return NF_DROP;
-+}
-+
-+static int chaos_tg_check(const char *tablename, const void *entry,
-+ const struct xt_target *target, void *targinfo, unsigned int hook_mask)
-+{
-+ const struct xt_chaos_target_info *info = targinfo;
-+
-+ if (info->variant == XTCHAOS_DELUDE && !have_delude) {
-+ printk(KERN_WARNING PFX "Error: Cannot use --delude when "
-+ "DELUDE module not available\n");
-+ return false;
-+ }
-+ if (info->variant == XTCHAOS_TARPIT && !have_tarpit) {
-+ printk(KERN_WARNING PFX "Error: Cannot use --tarpit when "
-+ "TARPIT module not available\n");
-+ return false;
-+ }
-+
-+ return true;
-+}
-+
-+static struct xt_target chaos_tg_reg = {
-+ .name = "CHAOS",
-+ .family = AF_INET,
-+ .table = "filter",
-+ .hooks = (1 << NF_IP_LOCAL_IN) | (1 << NF_IP_FORWARD) |
-+ (1 << NF_IP_LOCAL_OUT),
-+ .checkentry = chaos_tg_check,
-+ .target = chaos_tg,
-+ .targetsize = sizeof(struct xt_chaos_target_info),
-+ .me = THIS_MODULE,
-+};
-+
-+static int __init chaos_tg_init(void)
-+{
-+ int ret = -EINVAL;
-+
-+ xm_tcp = xt_request_find_match(AF_INET, "tcp", 0);
-+ if (xm_tcp == NULL) {
-+ printk(KERN_WARNING PFX "Error: Could not find or load "
-+ "\"tcp\" match\n");
-+ return -EINVAL;
-+ }
-+
-+ xt_reject = xt_request_find_target(AF_INET, "REJECT", 0);
-+ if (xt_reject == NULL) {
-+ printk(KERN_WARNING PFX "Error: Could not find or load "
-+ "\"REJECT\" target\n");
-+ goto out2;
-+ }
-+
-+ xt_tarpit = xt_request_find_target(AF_INET, "TARPIT", 0);
-+ have_tarpit = xt_tarpit != NULL;
-+ if (!have_tarpit)
-+ printk(KERN_WARNING PFX "Warning: Could not find or load "
-+ "\"TARPIT\" target\n");
-+
-+ xt_delude = xt_request_find_target(AF_INET, "DELUDE", 0);
-+ have_delude = xt_delude != NULL;
-+ if (!have_delude)
-+ printk(KERN_WARNING PFX "Warning: Could not find or load "
-+ "\"DELUDE\" target\n");
-+
-+ if ((ret = xt_register_target(&chaos_tg_reg)) != 0) {
-+ printk(KERN_WARNING PFX "xt_register_target returned "
-+ "error %d\n", ret);
-+ goto out3;
-+ }
-+
-+ return 0;
-+
-+ out3:
-+ if (have_delude)
-+ module_put(xt_delude->me);
-+ if (have_tarpit)
-+ module_put(xt_tarpit->me);
-+ module_put(xt_reject->me);
-+ out2:
-+ module_put(xm_tcp->me);
-+ return ret;
-+}
-+
-+static void __exit chaos_tg_exit(void)
-+{
-+ xt_unregister_target(&chaos_tg_reg);
-+ module_put(xm_tcp->me);
-+ module_put(xt_reject->me);
-+ if (have_delude)
-+ module_put(xt_delude->me);
-+ if (have_tarpit)
-+ module_put(xt_tarpit->me);
-+ return;
-+}
-+
-+module_init(chaos_tg_init);
-+module_exit(chaos_tg_exit);
-+MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
-+MODULE_DESCRIPTION("netfilter \"CHAOS\" target");
-+MODULE_LICENSE("GPL");
-+MODULE_ALIAS("ipt_CHAOS");
---- /dev/null
-+++ b/net/netfilter/xt_DELUDE.c
-@@ -0,0 +1,197 @@
-+/*
-+ * DELUDE target
-+ * Copyright © CC Computer Consultants GmbH, 2007
-+ * Contact: Jan Engelhardt <jengelh@computergmbh.de>
-+ *
-+ * Based upon linux-2.6.18.5/net/ipv4/netfilter/ipt_REJECT.c:
-+ * (C) 1999-2001 Paul `Rusty' Russell
-+ * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
-+ *
-+ * xt_DELUDE acts like REJECT, but does reply with SYN-ACK on SYN.
-+ *
-+ * This program is free software; you can redistribute it and/or modify
-+ * it under the terms of the GNU General Public License version 2 as
-+ * published by the Free Software Foundation.
-+ */
-+#include <linux/module.h>
-+#include <linux/skbuff.h>
-+#include <linux/ip.h>
-+#include <linux/tcp.h>
-+#include <linux/netfilter/x_tables.h>
-+#ifdef CONFIG_BRIDGE_NETFILTER
-+# include <linux/netfilter_bridge.h>
-+#endif
-+#include <net/tcp.h>
-+#define PFX KBUILD_MODNAME ": "
-+
-+static void delude_send_reset(struct sk_buff *oldskb, unsigned int hook)
-+{
-+ struct tcphdr _otcph, *oth, *tcph;
-+ unsigned int addr_type;
-+ struct sk_buff *nskb;
-+ u_int16_t tmp_port;
-+ u_int32_t tmp_addr;
-+ struct iphdr *niph;
-+ bool needs_ack;
-+
-+ /* IP header checks: fragment. */
-+ if (ip_hdr(oldskb)->frag_off & htons(IP_OFFSET))
-+ return;
-+
-+ oth = skb_header_pointer(oldskb, ip_hdrlen(oldskb),
-+ sizeof(_otcph), &_otcph);
-+ if (oth == NULL)
-+ return;
-+
-+ /* No RST for RST. */
-+ if (oth->rst)
-+ return;
-+
-+ /* Check checksum */
-+ if (nf_ip_checksum(oldskb, hook, ip_hdrlen(oldskb), IPPROTO_TCP))
-+ return;
-+
-+ /* We need a linear, writeable skb. We also need to expand
-+ headroom in case hh_len of incoming interface < hh_len of
-+ outgoing interface */
-+ nskb = skb_copy_expand(oldskb, LL_MAX_HEADER, skb_tailroom(oldskb),
-+ GFP_ATOMIC);
-+ if (!nskb)
-+ return;
-+
-+ /* This packet will not be the same as the other: clear nf fields */
-+ nf_reset(nskb);
-+ nskb->mark = 0;
-+ skb_init_secmark(nskb);
-+
-+ skb_shinfo(nskb)->gso_size = 0;
-+ skb_shinfo(nskb)->gso_segs = 0;
-+ skb_shinfo(nskb)->gso_type = 0;
-+
-+ tcph = (struct tcphdr *)(skb_network_header(nskb) + ip_hdrlen(nskb));
-+
-+ /* Swap source and dest */
-+ niph = ip_hdr(nskb);
-+ tmp_addr = niph->saddr;
-+ niph->saddr = niph->daddr;
-+ niph->daddr = tmp_addr;
-+ tmp_port = tcph->source;
-+ tcph->source = tcph->dest;
-+ tcph->dest = tmp_port;
-+
-+ /* Truncate to length (no data) */
-+ tcph->doff = sizeof(struct tcphdr) / 4;
-+ skb_trim(nskb, ip_hdrlen(nskb) + sizeof(struct tcphdr));
-+ niph->tot_len = htons(nskb->len);
-+
-+ if (oth->syn && !oth->ack && !oth->rst && !oth->fin) {
-+ /* DELUDE essential part */
-+ tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn + oth->fin +
-+ oldskb->len - ip_hdrlen(oldskb) -
-+ (oth->doff << 2));
-+ tcph->seq = false;
-+ tcph->ack = true;
-+ } else {
-+ if (!tcph->ack) {
-+ needs_ack = true;
-+ tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn +
-+ oth->fin + oldskb->len -
-+ ip_hdrlen(oldskb) - (oth->doff<<2));
-+ tcph->seq = false;
-+ } else {
-+ needs_ack = false;
-+ tcph->seq = oth->ack_seq;
-+ tcph->ack_seq = false;
-+ }
-+
-+ /* Reset flags */
-+ ((u_int8_t *)tcph)[13] = 0;
-+ tcph->rst = true;
-+ tcph->ack = needs_ack;
-+ }
-+
-+ tcph->window = 0;
-+ tcph->urg_ptr = 0;
-+
-+ /* Adjust TCP checksum */
-+ tcph->check = 0;
-+ tcph->check = tcp_v4_check(sizeof(struct tcphdr), niph->saddr,
-+ niph->daddr, csum_partial((char *)tcph,
-+ sizeof(struct tcphdr), 0));
-+
-+ /* Set DF, id = 0 */
-+ niph->frag_off = htons(IP_DF);
-+ niph->id = 0;
-+
-+ addr_type = RTN_UNSPEC;
-+#ifdef CONFIG_BRIDGE_NETFILTER
-+ if (hook != NF_IP_FORWARD || (nskb->nf_bridge != NULL &&
-+ nskb->nf_bridge->mask & BRNF_BRIDGED))
-+#else
-+ if (hook != NF_IP_FORWARD)
-+#endif
-+ addr_type = RTN_LOCAL;
-+
-+ if (ip_route_me_harder(&nskb, addr_type))
-+ goto free_nskb;
-+
-+ nskb->ip_summed = CHECKSUM_NONE;
-+
-+ /* Adjust IP TTL */
-+ niph->ttl = dst_metric(nskb->dst, RTAX_HOPLIMIT);
-+
-+ /* Adjust IP checksum */
-+ niph->check = 0;
-+ niph->check = ip_fast_csum(skb_network_header(nskb), niph->ihl);
-+
-+ /* "Never happens" */
-+ if (nskb->len > dst_mtu(nskb->dst))
-+ goto free_nskb;
-+
-+ nf_ct_attach(nskb, oldskb);
-+
-+ NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, nskb, NULL, nskb->dst->dev,
-+ dst_output);
-+ return;
-+
-+ free_nskb:
-+ kfree_skb(nskb);
-+}
-+
-+static unsigned int delude_tg(struct sk_buff **pskb,
-+ const struct net_device *in, const struct net_device *out,
-+ unsigned int hooknum, const struct xt_target *target, const void *targinfo)
-+{
-+ /* WARNING: This code causes reentry within iptables.
-+ This means that the iptables jump stack is now crap. We
-+ must return an absolute verdict. --RR */
-+ delude_send_reset(*pskb, hooknum);
-+ return NF_DROP;
-+}
-+
-+static struct xt_target delude_tg_reg = {
-+ .name = "DELUDE",
-+ .family = AF_INET,
-+ .table = "filter",
-+ .hooks = (1 << NF_IP_LOCAL_IN) | (1 << NF_IP_FORWARD),
-+ .target = delude_tg,
-+ .proto = IPPROTO_TCP,
-+ .me = THIS_MODULE,
-+};
-+
-+static int __init delude_tg_init(void)
-+{
-+ return xt_register_target(&delude_tg_reg);
-+}
-+
-+static void __exit delude_tg_exit(void)
-+{
-+ xt_unregister_target(&delude_tg_reg);
-+}
-+
-+module_init(delude_tg_init);
-+module_exit(delude_tg_exit);
-+MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
-+MODULE_DESCRIPTION("netfilter \"DELUDE\" target");
-+MODULE_LICENSE("GPL");
-+MODULE_ALIAS("ipt_DELUDE");
---- /dev/null
-+++ b/net/netfilter/xt_portscan.c
-@@ -0,0 +1,269 @@
-+/*
-+ * portscan match for netfilter
-+ * 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 <linux/in.h>
-+#include <linux/ip.h>
-+#include <linux/module.h>
-+#include <linux/moduleparam.h>
-+#include <linux/skbuff.h>
-+#include <linux/stat.h>
-+#include <linux/tcp.h>
-+#include <linux/types.h>
-+#include <linux/version.h>
-+#include <linux/netfilter/x_tables.h>
-+#include <linux/netfilter/xt_tcpudp.h>
-+#include <net/netfilter/nf_nat_rule.h>
-+#if defined(_LOCAL)
-+# include "xt_portscan.h"
-+#elif defined(CONFIG_NETFILTER_XT_MATCH_PORTSCAN) || \
-+ defined(CONFIG_NETFILTER_XT_MATCH_PORTSCAN_MODULE)
-+# include <linux/netfilter/xt_portscan.h>
-+#else
-+# include "xt_portscan.h"
-+#endif
-+#define PFX KBUILD_MODNAME ": "
-+
-+enum {
-+ TCP_FLAGS_ALL3 = TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_SYN,
-+ TCP_FLAGS_ALL4 = TCP_FLAGS_ALL3 | TCP_FLAG_ACK,
-+ TCP_FLAGS_ALL6 = TCP_FLAGS_ALL4 | TCP_FLAG_PSH | TCP_FLAG_URG,
-+};
-+
-+/* Module parameters */
-+static unsigned int
-+ connmark_mask = ~0,
-+ packet_mask = ~0,
-+ mark_seen = 0x9,
-+ mark_synrcv = 0x1,
-+ mark_closed = 0x2,
-+ mark_synscan = 0x3,
-+ mark_estab1 = 0x4,
-+ mark_estab2 = 0x5,
-+ mark_cnscan = 0x6,
-+ mark_grscan = 0x7,
-+ mark_valid = 0x8;
-+
-+module_param(connmark_mask, uint, S_IRUGO | S_IWUSR);
-+module_param(packet_mask, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_seen, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_synrcv, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_closed, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_synscan, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_estab1, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_estab2, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_cnscan, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_grscan, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_valid, uint, S_IRUGO | S_IWUSR);
-+MODULE_PARM_DESC(connmark_mask, "only set specified bits in connection mark");
-+MODULE_PARM_DESC(packet_mask, "only set specified bits in packet mark");
-+MODULE_PARM_DESC(mark_seen, "nfmark value for packet-seen state");
-+MODULE_PARM_DESC(mark_synrcv, "connmark value for SYN Received state");
-+MODULE_PARM_DESC(mark_closed, "connmark value for closed state");
-+MODULE_PARM_DESC(mark_synscan, "connmark value for SYN Scan state");
-+MODULE_PARM_DESC(mark_estab1, "connmark value for Established-1 state");
-+MODULE_PARM_DESC(mark_estab2, "connmark value for Established-2 state");
-+MODULE_PARM_DESC(mark_cnscan, "connmark value for Connect Scan state");
-+MODULE_PARM_DESC(mark_grscan, "connmark value for Grab Scan state");
-+MODULE_PARM_DESC(mark_valid, "connmark value for Valid state");
-+
-+/* TCP flag functions */
-+static inline bool tflg_ack4(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL4) == TCP_FLAG_ACK;
-+}
-+
-+static inline bool tflg_ack6(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL6) == TCP_FLAG_ACK;
-+}
-+
-+static inline bool tflg_fin(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL3) == TCP_FLAG_FIN;
-+}
-+
-+static inline bool tflg_rst(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL3) == TCP_FLAG_RST;
-+}
-+
-+static inline bool tflg_rstack(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL4) ==
-+ (TCP_FLAG_ACK | TCP_FLAG_RST);
-+}
-+
-+static inline bool tflg_syn(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL4) == TCP_FLAG_SYN;
-+}
-+
-+static inline bool tflg_synack(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL4) ==
-+ (TCP_FLAG_SYN | TCP_FLAG_ACK);
-+}
-+
-+/* portscan functions */
-+static inline bool portscan_mt_stealth(const struct tcphdr *th)
-+{
-+ /*
-+ * "Connection refused" replies to our own probes must not be matched.
-+ */
-+ if (tflg_rstack(th))
-+ return false;
-+
-+ if (tflg_rst(th) && printk_ratelimit()) {
-+ printk(KERN_WARNING PFX "Warning: Pure RST received\n");
-+ return false;
-+ }
-+
-+ /*
-+ * -p tcp ! --syn -m conntrack --ctstate INVALID: Looking for non-start
-+ * packets that are not associated with any connection -- this will
-+ * match most scan types (NULL, XMAS, FIN) and ridiculous flag
-+ * combinations (SYN-RST, SYN-FIN, SYN-FIN-RST, FIN-RST, etc.).
-+ */
-+ return !tflg_syn(th);
-+}
-+
-+static inline unsigned int portscan_mt_full(int mark,
-+ enum ip_conntrack_info ctstate, bool loopback, const struct tcphdr *tcph,
-+ unsigned int payload_len)
-+{
-+ if (mark == mark_estab2) {
-+ /*
-+ * -m connmark --mark $ESTAB2
-+ */
-+ if (tflg_ack4(tcph) && payload_len == 0)
-+ return mark; /* keep mark */
-+ else if (tflg_rst(tcph) || tflg_fin(tcph))
-+ return mark_grscan;
-+ else
-+ return mark_valid;
-+ } else if (mark == mark_estab1) {
-+ /*
-+ * -m connmark --mark $ESTAB1
-+ */
-+ if (tflg_rst(tcph) || tflg_fin(tcph))
-+ return mark_cnscan;
-+ else if (!loopback && tflg_ack4(tcph) && payload_len == 0)
-+ return mark_estab2;
-+ else
-+ return mark_valid;
-+ } else if (mark == mark_synrcv) {
-+ /*
-+ * -m connmark --mark $SYN
-+ */
-+ if (loopback && tflg_synack(tcph))
-+ return mark; /* keep mark */
-+ else if (loopback && tflg_rstack(tcph))
-+ return mark_closed;
-+ else if (tflg_ack6(tcph))
-+ return mark_estab1;
-+ else
-+ return mark_synscan;
-+ } else if (ctstate == IP_CT_NEW && tflg_syn(tcph)) {
-+ /*
-+ * -p tcp --syn --ctstate NEW
-+ */
-+ return mark_synrcv;
-+ }
-+ return mark;
-+}
-+
-+static int portscan_mt(const struct sk_buff *skb,
-+ const struct net_device *in, const struct net_device *out,
-+ const struct xt_match *match, const void *matchinfo, int offset,
-+ unsigned int protoff, int *hotdrop)
-+{
-+ const struct xt_portscan_match_info *info = matchinfo;
-+ enum ip_conntrack_info ctstate;
-+ const struct tcphdr *tcph;
-+ struct nf_conn *ctdata;
-+ struct tcphdr tcph_buf;
-+
-+ tcph = skb_header_pointer(skb, protoff, sizeof(tcph_buf), &tcph_buf);
-+ if (tcph == NULL)
-+ return false;
-+
-+ /* Check for invalid packets: -m conntrack --ctstate INVALID */
-+ if ((ctdata = nf_ct_get(skb, &ctstate)) == NULL) {
-+ if (info->match_stealth)
-+ return portscan_mt_stealth(tcph);
-+ /*
-+ * If @ctdata is NULL, we cannot match the other scan
-+ * types, return.
-+ */
-+ return false;
-+ }
-+
-+ /*
-+ * If -m portscan was previously applied to this packet, the rules we
-+ * simulate must not be run through again. And for speedup, do not call
-+ * it either when the connection is already VALID.
-+ */
-+ if ((ctdata->mark & connmark_mask) == mark_valid ||
-+ (skb->mark & packet_mask) != mark_seen) {
-+ unsigned int n;
-+
-+ n = portscan_mt_full(ctdata->mark & connmark_mask, ctstate,
-+ in == &loopback_dev, tcph,
-+ skb->len - protoff - 4 * tcph->doff);
-+
-+ ctdata->mark = (ctdata->mark & ~connmark_mask) | n;
-+ ((struct sk_buff *)skb)->mark =
-+ (skb->mark & ~packet_mask) ^ mark_seen;
-+ }
-+
-+ return (info->match_syn && ctdata->mark == mark_synscan) ||
-+ (info->match_cn && ctdata->mark == mark_cnscan) ||
-+ (info->match_gr && ctdata->mark == mark_grscan);
-+}
-+
-+static int portscan_mt_check(const char *tablename, const void *entry,
-+ const struct xt_match *match, void *matchinfo, unsigned int hook_mask)
-+{
-+ const struct xt_portscan_match_info *info = matchinfo;
-+
-+ if ((info->match_stealth & ~1) || (info->match_syn & ~1) ||
-+ (info->match_cn & ~1) || (info->match_gr & ~1)) {
-+ printk(KERN_WARNING PFX "Invalid flags\n");
-+ return false;
-+ }
-+ return true;
-+}
-+
-+static struct xt_match portscan_mt_reg __read_mostly = {
-+ .name = "portscan",
-+ .family = AF_INET,
-+ .match = portscan_mt,
-+ .checkentry = portscan_mt_check,
-+ .matchsize = sizeof(struct xt_portscan_match_info),
-+ .proto = IPPROTO_TCP,
-+ .me = THIS_MODULE,
-+};
-+
-+static int __init portscan_mt_init(void)
-+{
-+ return xt_register_match(&portscan_mt_reg);
-+}
-+
-+static void __exit portscan_mt_exit(void)
-+{
-+ xt_unregister_match(&portscan_mt_reg);
-+ return;
-+}
-+
-+module_init(portscan_mt_init);
-+module_exit(portscan_mt_exit);
-+MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
-+MODULE_DESCRIPTION("netfilter \"portscan\" match");
-+MODULE_LICENSE("GPL");
-+MODULE_ALIAS("ipt_portscan");
+++ /dev/null
---- a/net/netfilter/Kconfig
-+++ b/net/netfilter/Kconfig
-@@ -414,6 +414,23 @@ config NETFILTER_XT_TARGET_CONNSECMARK
-
- To compile it as a module, choose M here. If unsure, say N.
-
-+config NETFILTER_XT_TARGET_TARPIT
-+ tristate '"TARPIT" target support'
-+ depends on NETFILTER_XTABLES
-+ ---help---
-+ Adds a TARPIT target to iptables, which 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 does not require dedicated
-+ hardware or IPs. Any TCP port that you would normally DROP or REJECT
-+ can instead become a tarpit.
-+
- config NETFILTER_XT_TARGET_TCPMSS
- tristate '"TCPMSS" target support'
- depends on NETFILTER_XTABLES && (IPV6 || IPV6=n)
---- a/net/netfilter/Makefile
-+++ b/net/netfilter/Makefile
-@@ -45,6 +45,7 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_NFQUEUE
- obj-$(CONFIG_NETFILTER_XT_TARGET_NFLOG) += xt_NFLOG.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_NOTRACK) += xt_NOTRACK.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_SECMARK) += xt_SECMARK.o
-+obj-$(CONFIG_NETFILTER_XT_TARGET_TARPIT) += xt_TARPIT.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_TCPMSS) += xt_TCPMSS.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_CONNSECMARK) += xt_CONNSECMARK.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_CHAOS) += xt_CHAOS.o
---- /dev/null
-+++ b/net/netfilter/xt_TARPIT.c
-@@ -0,0 +1,280 @@
-+/*
-+ * Kernel module to capture and hold incoming TCP connections using
-+ * no local per-connection resources.
-+ *
-+ * Based on ipt_REJECT.c and offering functionality similar to
-+ * LaBrea <http://www.hackbusters.net/LaBrea/>.
-+ *
-+ * Copyright (c) 2002 Aaron Hopkins <tools@die.net>
-+ *
-+ * This program is free software; you can redistribute it and/or modify
-+ * it under the terms of the GNU General Public License as published by
-+ * the Free Software Foundation; either version 2 of the License, or
-+ * (at your option) any later version.
-+ *
-+ * This program is distributed in the hope that it will be useful,
-+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
-+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-+ * GNU General Public License for more details.
-+ *
-+ * You should have received a copy of the GNU General Public License
-+ * along with this program; if not, write to the Free Software
-+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-+ *
-+ * Goal:
-+ * - Allow incoming TCP connections to be established.
-+ * - Passing data should result in the connection being switched to the
-+ * persist state (0 byte window), in which the remote side stops sending
-+ * data and asks to continue every 60 seconds.
-+ * - Attempts to shut down the connection should be ignored completely, so
-+ * the remote side ends up having to time it out.
-+ *
-+ * This means:
-+ * - Reply to TCP SYN,!ACK,!RST,!FIN with SYN-ACK, window 5 bytes
-+ * - Reply to TCP SYN,ACK,!RST,!FIN with RST to prevent spoofing
-+ * - Reply to TCP !SYN,!RST,!FIN with ACK, window 0 bytes, rate-limited
-+ */
-+
-+#include <linux/version.h>
-+#include <linux/module.h>
-+#include <linux/skbuff.h>
-+#include <linux/ip.h>
-+#include <net/ip.h>
-+#include <net/tcp.h>
-+#include <net/icmp.h>
-+struct in_device;
-+#include <net/route.h>
-+#include <linux/random.h>
-+#include <linux/netfilter_ipv4/ip_tables.h>
-+
-+#if 0
-+#define DEBUGP printk
-+#else
-+#define DEBUGP(format, args...)
-+#endif
-+
-+/* Stolen from ip_finish_output2 */
-+static int ip_direct_send(struct sk_buff *skb)
-+{
-+ struct dst_entry *dst = skb->dst;
-+
-+ if (dst->hh != NULL)
-+ return neigh_hh_output(dst->hh, skb);
-+ else if (dst->neighbour != NULL)
-+ return dst->neighbour->output(skb);
-+
-+ if (net_ratelimit())
-+ printk(KERN_DEBUG "TARPIT ip_direct_send: no header cache and no neighbor!\n");
-+
-+ kfree_skb(skb);
-+ return -EINVAL;
-+}
-+
-+
-+/* Send reply */
-+static void tarpit_tcp(const struct sk_buff *oskb, struct rtable *ort,
-+ unsigned int local)
-+{
-+ struct sk_buff *nskb;
-+ struct rtable *nrt;
-+ struct tcphdr *otcph, *ntcph;
-+ struct flowi fl = {};
-+ unsigned int otcplen;
-+ u_int16_t tmp;
-+
-+ const struct iphdr *oiph = ip_hdr(oskb);
-+ struct iphdr *niph;
-+
-+ /* A truncated TCP header is not going to be useful */
-+ if (oskb->len < ip_hdrlen(oskb) + sizeof(struct tcphdr))
-+ return;
-+
-+ otcph = (void *)oiph + ip_hdrlen(oskb);
-+ otcplen = oskb->len - ip_hdrlen(oskb);
-+
-+ /* No replies for RST or FIN */
-+ if (otcph->rst || otcph->fin)
-+ return;
-+
-+ /* No reply to !SYN,!ACK. Rate-limit replies to !SYN,ACKs */
-+ if (!otcph->syn && (!otcph->ack || !xrlim_allow(&ort->u.dst, 1*HZ)))
-+ return;
-+
-+ /* Check checksum. */
-+ if (tcp_v4_check(otcplen, oiph->saddr, oiph->daddr,
-+ csum_partial((char *)otcph, otcplen, 0)) != 0)
-+ return;
-+
-+ /*
-+ * Copy skb (even if skb is about to be dropped, we cannot just
-+ * clone it because there may be other things, such as tcpdump,
-+ * interested in it)
-+ */
-+ nskb = skb_copy(oskb, GFP_ATOMIC);
-+ if (nskb == NULL)
-+ return;
-+
-+ niph = ip_hdr(nskb);
-+
-+ /* This packet will not be the same as the other: clear nf fields */
-+ nf_conntrack_put(nskb->nfct);
-+ nskb->nfct = NULL;
-+#ifdef CONFIG_NETFILTER_DEBUG
-+ nskb->nf_debug = 0;
-+#endif
-+
-+ ntcph = (void *)niph + ip_hdrlen(nskb);
-+
-+ /* Truncate to length (no data) */
-+ ntcph->doff = sizeof(struct tcphdr)/4;
-+ skb_trim(nskb, ip_hdrlen(nskb) + sizeof(struct tcphdr));
-+ niph->tot_len = htons(nskb->len);
-+
-+ /* Swap source and dest */
-+ niph->daddr = xchg(&niph->saddr, niph->daddr);
-+ tmp = ntcph->source;
-+ ntcph->source = ntcph->dest;
-+ ntcph->dest = tmp;
-+
-+ /* Use supplied sequence number or make a new one */
-+ ntcph->seq = otcph->ack ? otcph->ack_seq
-+ : htonl(secure_tcp_sequence_number(niph->saddr,
-+ niph->daddr,
-+ ntcph->source,
-+ ntcph->dest));
-+
-+ /* Our SYN-ACKs must have a >0 window */
-+ ntcph->window = (otcph->syn && !otcph->ack) ? htons(5) : 0;
-+
-+ ntcph->urg_ptr = 0;
-+
-+ /* Reset flags */
-+ ((u_int8_t *)ntcph)[13] = 0;
-+
-+ if (otcph->syn && otcph->ack) {
-+ ntcph->rst = 1;
-+ ntcph->ack_seq = 0;
-+ } else {
-+ ntcph->syn = otcph->syn;
-+ ntcph->ack = 1;
-+ ntcph->ack_seq = htonl(ntohl(otcph->seq) + otcph->syn);
-+ }
-+
-+ /* Adjust TCP checksum */
-+ ntcph->check = 0;
-+ ntcph->check = tcp_v4_check(sizeof(struct tcphdr),
-+ niph->saddr,
-+ niph->daddr,
-+ csum_partial((char *)ntcph,
-+ sizeof(struct tcphdr), 0));
-+
-+ fl.nl_u.ip4_u.daddr = niph->daddr;
-+ fl.nl_u.ip4_u.saddr = local ? niph->saddr : 0;
-+ fl.nl_u.ip4_u.tos = RT_TOS(niph->tos) | RTO_CONN;
-+ fl.oif = 0;
-+
-+ if (ip_route_output_key(&nrt, &fl))
-+ goto free_nskb;
-+
-+ dst_release(nskb->dst);
-+ nskb->dst = &nrt->u.dst;
-+
-+ /* Adjust IP TTL */
-+ niph->ttl = dst_metric(nskb->dst, RTAX_HOPLIMIT);
-+
-+ /* Set DF, id = 0 */
-+ niph->frag_off = htons(IP_DF);
-+ niph->id = 0;
-+
-+ /* Adjust IP checksum */
-+ niph->check = 0;
-+ niph->check = ip_fast_csum((unsigned char *)niph, niph->ihl);
-+
-+ /* "Never happens" */
-+ if (nskb->len > dst_mtu(nskb->dst))
-+ goto free_nskb;
-+
-+ ip_direct_send(nskb);
-+ return;
-+
-+ free_nskb:
-+ kfree_skb(nskb);
-+}
-+
-+static unsigned int xt_tarpit_target(struct sk_buff **pskb,
-+ const struct net_device *in,
-+ const struct net_device *out,
-+ unsigned int hooknum,
-+ const struct xt_target *target,
-+ const void *targinfo)
-+{
-+ const struct sk_buff *skb = *pskb;
-+ const struct iphdr *iph = ip_hdr(skb);
-+ struct rtable *rt = (void *)skb->dst;
-+
-+ /* Do we have an input route cache entry? */
-+ if (rt == NULL)
-+ return NF_DROP;
-+
-+ /* No replies to physical multicast/broadcast */
-+ if (skb->pkt_type != PACKET_HOST && skb->pkt_type != PACKET_OTHERHOST)
-+ return NF_DROP;
-+
-+ /* Now check at the protocol level */
-+ if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
-+ return NF_DROP;
-+
-+ /*
-+ * Our naive response construction does not deal with IP
-+ * options, and probably should not try.
-+ */
-+ if (iph->ihl * 4 != sizeof(struct iphdr))
-+ return NF_DROP;
-+
-+ /* We are not interested in fragments */
-+ if (iph->frag_off & htons(IP_OFFSET))
-+ return NF_DROP;
-+
-+ tarpit_tcp(skb, rt, hooknum == NF_IP_LOCAL_IN);
-+ return NF_DROP;
-+}
-+
-+static int xt_tarpit_check(const char *tablename, const void *entry,
-+ const struct xt_target *target, void *targinfo,
-+ unsigned int hook_mask)
-+{
-+ bool invalid;
-+
-+ if (strcmp(tablename, "raw") == 0 && hook_mask == NF_IP_PRE_ROUTING)
-+ return true;
-+ if (strcmp(tablename, "filter") != 0)
-+ return false;
-+ invalid = hook_mask & ~((1 << NF_IP_LOCAL_IN) | (1 << NF_IP_FORWARD));
-+ return !invalid;
-+}
-+
-+static struct xt_target xt_tarpit_reg = {
-+ .name = "TARPIT",
-+ .family = AF_INET,
-+ .proto = IPPROTO_TCP,
-+ .target = xt_tarpit_target,
-+ .checkentry = xt_tarpit_check,
-+ .me = THIS_MODULE,
-+};
-+
-+static int __init xt_tarpit_init(void)
-+{
-+ return xt_register_target(&xt_tarpit_reg);
-+}
-+
-+static void __exit xt_tarpit_exit(void)
-+{
-+ xt_unregister_target(&xt_tarpit_reg);
-+}
-+
-+module_init(xt_tarpit_init);
-+module_exit(xt_tarpit_exit);
-+MODULE_DESCRIPTION("netfilter xt_TARPIT target module");
-+MODULE_AUTHOR("Jan Engelhardt <jengelh@gmx.de>");
-+MODULE_LICENSE("GPL");
-+MODULE_ALIAS("ipt_TARPIT");
help
H.323 is a VoIP signalling protocol from ITU-T. As one of the most
important VoIP protocols, it is widely used by voice hardware and
-@@ -433,7 +433,7 @@ config NETFILTER_XT_TARGET_TARPIT
+@@ -400,7 +400,7 @@ config NETFILTER_XT_TARGET_CONNSECMARK
config NETFILTER_XT_TARGET_TCPMSS
tristate '"TCPMSS" target support'
+++ /dev/null
---- a/include/linux/netfilter/Kbuild
-+++ b/include/linux/netfilter/Kbuild
-@@ -3,6 +3,7 @@ header-y += nf_conntrack_tuple_common.h
- header-y += nfnetlink_conntrack.h
- header-y += nfnetlink_log.h
- header-y += nfnetlink_queue.h
-+header-y += xt_CHAOS.h
- header-y += xt_CLASSIFY.h
- header-y += xt_comment.h
- header-y += xt_connbytes.h
---- /dev/null
-+++ b/include/linux/netfilter/oot_conntrack.h
-@@ -0,0 +1,5 @@
-+#if defined(CONFIG_IP_NF_CONNTRACK) || defined(CONFIG_IP_NF_CONNTRACK_MODULE)
-+# include <linux/netfilter_ipv4/ip_conntrack.h>
-+#else /* linux-2.6.20+ */
-+# include <net/netfilter/nf_nat_rule.h>
-+#endif
---- /dev/null
-+++ b/include/linux/netfilter/oot_trans.h
-@@ -0,0 +1,14 @@
-+/* Out of tree workarounds */
-+#include <linux/version.h>
-+#if LINUX_VERSION_CODE <= KERNEL_VERSION(2, 6, 18)
-+# define HAVE_MATCHINFOSIZE 1
-+# define HAVE_TARGUSERINFO 1
-+# define HAVE_TARGINFOSIZE 1
-+#endif
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 20)
-+# define nfmark mark
-+#endif
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 21)
-+# define tcp_v4_check(tcph, tcph_sz, s, d, csp) \
-+ tcp_v4_check((tcph_sz), (s), (d), (csp))
-+#endif
---- /dev/null
-+++ b/include/linux/netfilter/xt_CHAOS.h
-@@ -0,0 +1,14 @@
-+#ifndef _LINUX_NETFILTER_XT_CHAOS_H
-+#define _LINUX_NETFILTER_XT_CHAOS_H 1
-+
-+enum xt_chaos_target_variant {
-+ XTCHAOS_NORMAL,
-+ XTCHAOS_TARPIT,
-+ XTCHAOS_DELUDE,
-+};
-+
-+struct xt_chaos_target_info {
-+ uint8_t variant;
-+};
-+
-+#endif /* _LINUX_NETFILTER_XT_CHAOS_H */
---- /dev/null
-+++ b/include/linux/netfilter/xt_portscan.h
-@@ -0,0 +1,8 @@
-+#ifndef _LINUX_NETFILTER_XT_PORTSCAN_H
-+#define _LINUX_NETFILTER_XT_PORTSCAN_H 1
-+
-+struct xt_portscan_match_info {
-+ uint8_t match_stealth, match_syn, match_cn, match_gr;
-+};
-+
-+#endif /* _LINUX_NETFILTER_XT_PORTSCAN_H */
---- /dev/null
-+++ b/net/netfilter/find_match.c
-@@ -0,0 +1,39 @@
-+/*
-+ xt_request_find_match
-+ by Jan Engelhardt <jengelh [at] gmx de>, 2006 - 2007
-+
-+ Based upon linux-2.6.18.5/net/netfilter/x_tables.c:
-+ Copyright (C) 2006-2006 Harald Welte <laforge@netfilter.org>
-+ This program is free software; you can redistribute it and/or modify
-+ it under the terms of the GNU General Public License version 2 as
-+ published by the Free Software Foundation.
-+*/
-+#include <linux/err.h>
-+#include <linux/netfilter_arp.h>
-+#include <linux/socket.h>
-+#include <linux/netfilter/x_tables.h>
-+
-+/*
-+ * Yeah this code is sub-optimal, but the function is missing in
-+ * mainline so far. -jengelh
-+ */
-+static struct xt_match *xt_request_find_match_lo(int af, const char *name,
-+ u8 revision)
-+{
-+ static const char *const xt_prefix[] = {
-+ [AF_INET] = "ip",
-+ [AF_INET6] = "ip6",
-+ [NF_ARP] = "arp",
-+ };
-+ struct xt_match *match;
-+
-+ match = try_then_request_module(xt_find_match(af, name, revision),
-+ "%st_%s", xt_prefix[af], name);
-+ if (IS_ERR(match) || match == NULL)
-+ return NULL;
-+
-+ return match;
-+}
-+
-+/* In case it goes into mainline, let this out-of-tree package compile */
-+#define xt_request_find_match xt_request_find_match_lo
---- a/net/netfilter/Kconfig
-+++ b/net/netfilter/Kconfig
-@@ -265,6 +265,14 @@ config NETFILTER_XTABLES
-
- # alphabetically ordered list of targets
-
-+config NETFILTER_XT_TARGET_CHAOS
-+ tristate '"CHAOS" target support'
-+ depends on NETFILTER_XTABLES
-+ help
-+ This option adds a `CHAOS' target.
-+
-+ To compile it as a module, choose M here. If unsure, say N.
-+
- config NETFILTER_XT_TARGET_CLASSIFY
- tristate '"CLASSIFY" target support'
- depends on NETFILTER_XTABLES
-@@ -292,6 +300,14 @@ config NETFILTER_XT_TARGET_CONNMARK
- <file:Documentation/kbuild/modules.txt>. The module will be called
- ipt_CONNMARK.ko. If unsure, say `N'.
-
-+config NETFILTER_XT_TARGET_DELUDE
-+ tristate '"DELUDE" target support'
-+ depends on NETFILTER_XTABLES
-+ help
-+ This option adds a `DELUDE' target.
-+
-+ To compile it as a module, choose M here. If unsure, say N.
-+
- config NETFILTER_XT_TARGET_DSCP
- tristate '"DSCP" target support'
- depends on NETFILTER_XTABLES
-@@ -556,6 +572,14 @@ config NETFILTER_XT_MATCH_POLICY
-
- To compile it as a module, choose M here. If unsure, say N.
-
-+config NETFILTER_XT_MATCH_PORTSCAN
-+ tristate '"portscan" match support'
-+ depends on NETFILTER_XTABLES
-+ help
-+ This option adds a 'portscan' match support.
-+
-+ To compile it as a module, choose M here. If unsure, say N.
-+
- config NETFILTER_XT_MATCH_MULTIPORT
- tristate "Multiple port match support"
- depends on NETFILTER_XTABLES
---- a/net/netfilter/Makefile
-+++ b/net/netfilter/Makefile
-@@ -49,6 +49,8 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_TRACE)
- obj-$(CONFIG_NETFILTER_XT_TARGET_SECMARK) += xt_SECMARK.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_TCPMSS) += xt_TCPMSS.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_CONNSECMARK) += xt_CONNSECMARK.o
-+obj-$(CONFIG_NETFILTER_XT_TARGET_CHAOS) += xt_CHAOS.o
-+obj-$(CONFIG_NETFILTER_XT_TARGET_DELUDE) += xt_DELUDE.o
-
- # matches
- obj-$(CONFIG_NETFILTER_XT_MATCH_COMMENT) += xt_comment.o
-@@ -78,3 +80,4 @@ obj-$(CONFIG_NETFILTER_XT_MATCH_TCPMSS)
- obj-$(CONFIG_NETFILTER_XT_MATCH_PHYSDEV) += xt_physdev.o
- obj-$(CONFIG_NETFILTER_XT_MATCH_U32) += xt_u32.o
- obj-$(CONFIG_NETFILTER_XT_MATCH_HASHLIMIT) += xt_hashlimit.o
-+obj-$(CONFIG_NETFILTER_XT_MATCH_PORTSCAN) += xt_portscan.o
---- /dev/null
-+++ b/net/netfilter/xt_CHAOS.c
-@@ -0,0 +1,200 @@
-+/*
-+ * CHAOS target for netfilter
-+ * 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 <linux/icmp.h>
-+#include <linux/in.h>
-+#include <linux/ip.h>
-+#include <linux/module.h>
-+#include <linux/skbuff.h>
-+#include <linux/stat.h>
-+#include <linux/netfilter/x_tables.h>
-+#include <linux/netfilter/xt_tcpudp.h>
-+#include <linux/netfilter_ipv4/ipt_REJECT.h>
-+#include <net/ip.h>
-+#if defined(_LOCAL)
-+# include "xt_CHAOS.h"
-+# include "find_match.c"
-+#elif defined(CONFIG_NETFILTER_XT_TARGET_CHAOS) || \
-+ defined(CONFIG_NETFILTER_XT_TARGET_CHAOS_MODULE)
-+# include <linux/netfilter/xt_CHAOS.h>
-+# include "find_match.c"
-+#else
-+# include "xt_CHAOS.h"
-+# include "find_match.c"
-+#endif
-+#define PFX KBUILD_MODNAME ": "
-+
-+/* Module parameters */
-+static unsigned int reject_percentage = ~0U * .01;
-+static unsigned int delude_percentage = ~0U * .0101;
-+module_param(reject_percentage, uint, S_IRUGO | S_IWUSR);
-+module_param(delude_percentage, uint, S_IRUGO | S_IWUSR);
-+
-+/* References to other matches/targets */
-+static struct xt_match *xm_tcp;
-+static struct xt_target *xt_delude, *xt_reject, *xt_tarpit;
-+
-+static int have_delude, have_tarpit;
-+
-+/* Static data for other matches/targets */
-+static const struct ipt_reject_info reject_params = {
-+ .with = ICMP_HOST_UNREACH,
-+};
-+
-+static const struct xt_tcp tcp_params = {
-+ .spts = {0, ~0},
-+ .dpts = {0, ~0},
-+};
-+
-+/* CHAOS functions */
-+static void xt_chaos_total(const struct xt_chaos_target_info *info,
-+ struct sk_buff **pskb, const struct net_device *in,
-+ const struct net_device *out, unsigned int hooknum)
-+{
-+ const struct iphdr *iph = ip_hdr(*pskb);
-+ const int protoff = 4 * iph->ihl;
-+ const int offset = ntohs(iph->frag_off) & IP_OFFSET;
-+ const struct xt_target *destiny;
-+ bool hotdrop = false, ret;
-+
-+ ret = xm_tcp->match(*pskb, in, out, xm_tcp, &tcp_params,
-+ offset, protoff, &hotdrop);
-+ if (!ret || hotdrop || (unsigned int)net_random() > delude_percentage)
-+ return;
-+
-+ destiny = (info->variant == XTCHAOS_TARPIT) ? xt_tarpit : xt_delude;
-+ destiny->target(pskb, in, out, hooknum, destiny, NULL);
-+ return;
-+}
-+
-+static unsigned int chaos_tg(struct sk_buff **pskb,
-+ const struct net_device *in, const struct net_device *out,
-+ unsigned int hooknum, const struct xt_target *target, const void *targinfo)
-+{
-+ /*
-+ * Equivalent to:
-+ * -A chaos -m statistic --mode random --probability \
-+ * $reject_percentage -j REJECT --reject-with host-unreach;
-+ * -A chaos -p tcp -m statistic --mode random --probability \
-+ * $delude_percentage -j DELUDE;
-+ * -A chaos -j DROP;
-+ */
-+ const struct xt_chaos_target_info *info = targinfo;
-+ const struct iphdr *iph = ip_hdr(*pskb);
-+
-+ if ((unsigned int)net_random() <= reject_percentage)
-+ return xt_reject->target(pskb, in, out, hooknum, target,
-+ &reject_params);
-+
-+ /* TARPIT/DELUDE may not be called from the OUTPUT chain */
-+ if (iph->protocol == IPPROTO_TCP &&
-+ info->variant != XTCHAOS_NORMAL && hooknum != NF_IP_LOCAL_OUT)
-+ xt_chaos_total(info, pskb, in, out, hooknum);
-+
-+ return NF_DROP;
-+}
-+
-+static bool chaos_tg_check(const char *tablename, const void *entry,
-+ const struct xt_target *target, void *targinfo, unsigned int hook_mask)
-+{
-+ const struct xt_chaos_target_info *info = targinfo;
-+
-+ if (info->variant == XTCHAOS_DELUDE && !have_delude) {
-+ printk(KERN_WARNING PFX "Error: Cannot use --delude when "
-+ "DELUDE module not available\n");
-+ return false;
-+ }
-+ if (info->variant == XTCHAOS_TARPIT && !have_tarpit) {
-+ printk(KERN_WARNING PFX "Error: Cannot use --tarpit when "
-+ "TARPIT module not available\n");
-+ return false;
-+ }
-+
-+ return true;
-+}
-+
-+static struct xt_target chaos_tg_reg = {
-+ .name = "CHAOS",
-+ .family = AF_INET,
-+ .table = "filter",
-+ .hooks = (1 << NF_IP_LOCAL_IN) | (1 << NF_IP_FORWARD) |
-+ (1 << NF_IP_LOCAL_OUT),
-+ .checkentry = chaos_tg_check,
-+ .target = chaos_tg,
-+ .targetsize = sizeof(struct xt_chaos_target_info),
-+ .me = THIS_MODULE,
-+};
-+
-+static int __init chaos_tg_init(void)
-+{
-+ int ret = -EINVAL;
-+
-+ xm_tcp = xt_request_find_match(AF_INET, "tcp", 0);
-+ if (xm_tcp == NULL) {
-+ printk(KERN_WARNING PFX "Error: Could not find or load "
-+ "\"tcp\" match\n");
-+ return -EINVAL;
-+ }
-+
-+ xt_reject = xt_request_find_target(AF_INET, "REJECT", 0);
-+ if (xt_reject == NULL) {
-+ printk(KERN_WARNING PFX "Error: Could not find or load "
-+ "\"REJECT\" target\n");
-+ goto out2;
-+ }
-+
-+ xt_tarpit = xt_request_find_target(AF_INET, "TARPIT", 0);
-+ have_tarpit = xt_tarpit != NULL;
-+ if (!have_tarpit)
-+ printk(KERN_WARNING PFX "Warning: Could not find or load "
-+ "\"TARPIT\" target\n");
-+
-+ xt_delude = xt_request_find_target(AF_INET, "DELUDE", 0);
-+ have_delude = xt_delude != NULL;
-+ if (!have_delude)
-+ printk(KERN_WARNING PFX "Warning: Could not find or load "
-+ "\"DELUDE\" target\n");
-+
-+ if ((ret = xt_register_target(&chaos_tg_reg)) != 0) {
-+ printk(KERN_WARNING PFX "xt_register_target returned "
-+ "error %d\n", ret);
-+ goto out3;
-+ }
-+
-+ return 0;
-+
-+ out3:
-+ if (have_delude)
-+ module_put(xt_delude->me);
-+ if (have_tarpit)
-+ module_put(xt_tarpit->me);
-+ module_put(xt_reject->me);
-+ out2:
-+ module_put(xm_tcp->me);
-+ return ret;
-+}
-+
-+static void __exit chaos_tg_exit(void)
-+{
-+ xt_unregister_target(&chaos_tg_reg);
-+ module_put(xm_tcp->me);
-+ module_put(xt_reject->me);
-+ if (have_delude)
-+ module_put(xt_delude->me);
-+ if (have_tarpit)
-+ module_put(xt_tarpit->me);
-+ return;
-+}
-+
-+module_init(chaos_tg_init);
-+module_exit(chaos_tg_exit);
-+MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
-+MODULE_DESCRIPTION("netfilter \"CHAOS\" target");
-+MODULE_LICENSE("GPL");
-+MODULE_ALIAS("ipt_CHAOS");
---- /dev/null
-+++ b/net/netfilter/xt_DELUDE.c
-@@ -0,0 +1,197 @@
-+/*
-+ * DELUDE target
-+ * Copyright © CC Computer Consultants GmbH, 2007
-+ * Contact: Jan Engelhardt <jengelh@computergmbh.de>
-+ *
-+ * Based upon linux-2.6.18.5/net/ipv4/netfilter/ipt_REJECT.c:
-+ * (C) 1999-2001 Paul `Rusty' Russell
-+ * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
-+ *
-+ * xt_DELUDE acts like REJECT, but does reply with SYN-ACK on SYN.
-+ *
-+ * This program is free software; you can redistribute it and/or modify
-+ * it under the terms of the GNU General Public License version 2 as
-+ * published by the Free Software Foundation.
-+ */
-+#include <linux/module.h>
-+#include <linux/skbuff.h>
-+#include <linux/ip.h>
-+#include <linux/tcp.h>
-+#include <linux/netfilter/x_tables.h>
-+#ifdef CONFIG_BRIDGE_NETFILTER
-+# include <linux/netfilter_bridge.h>
-+#endif
-+#include <net/tcp.h>
-+#define PFX KBUILD_MODNAME ": "
-+
-+static void delude_send_reset(struct sk_buff *oldskb, unsigned int hook)
-+{
-+ struct tcphdr _otcph, *oth, *tcph;
-+ unsigned int addr_type;
-+ struct sk_buff *nskb;
-+ u_int16_t tmp_port;
-+ u_int32_t tmp_addr;
-+ struct iphdr *niph;
-+ bool needs_ack;
-+
-+ /* IP header checks: fragment. */
-+ if (ip_hdr(oldskb)->frag_off & htons(IP_OFFSET))
-+ return;
-+
-+ oth = skb_header_pointer(oldskb, ip_hdrlen(oldskb),
-+ sizeof(_otcph), &_otcph);
-+ if (oth == NULL)
-+ return;
-+
-+ /* No RST for RST. */
-+ if (oth->rst)
-+ return;
-+
-+ /* Check checksum */
-+ if (nf_ip_checksum(oldskb, hook, ip_hdrlen(oldskb), IPPROTO_TCP))
-+ return;
-+
-+ /* We need a linear, writeable skb. We also need to expand
-+ headroom in case hh_len of incoming interface < hh_len of
-+ outgoing interface */
-+ nskb = skb_copy_expand(oldskb, LL_MAX_HEADER, skb_tailroom(oldskb),
-+ GFP_ATOMIC);
-+ if (!nskb)
-+ return;
-+
-+ /* This packet will not be the same as the other: clear nf fields */
-+ nf_reset(nskb);
-+ nskb->mark = 0;
-+ skb_init_secmark(nskb);
-+
-+ skb_shinfo(nskb)->gso_size = 0;
-+ skb_shinfo(nskb)->gso_segs = 0;
-+ skb_shinfo(nskb)->gso_type = 0;
-+
-+ tcph = (struct tcphdr *)(skb_network_header(nskb) + ip_hdrlen(nskb));
-+
-+ /* Swap source and dest */
-+ niph = ip_hdr(nskb);
-+ tmp_addr = niph->saddr;
-+ niph->saddr = niph->daddr;
-+ niph->daddr = tmp_addr;
-+ tmp_port = tcph->source;
-+ tcph->source = tcph->dest;
-+ tcph->dest = tmp_port;
-+
-+ /* Truncate to length (no data) */
-+ tcph->doff = sizeof(struct tcphdr) / 4;
-+ skb_trim(nskb, ip_hdrlen(nskb) + sizeof(struct tcphdr));
-+ niph->tot_len = htons(nskb->len);
-+
-+ if (oth->syn && !oth->ack && !oth->rst && !oth->fin) {
-+ /* DELUDE essential part */
-+ tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn + oth->fin +
-+ oldskb->len - ip_hdrlen(oldskb) -
-+ (oth->doff << 2));
-+ tcph->seq = false;
-+ tcph->ack = true;
-+ } else {
-+ if (!tcph->ack) {
-+ needs_ack = true;
-+ tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn +
-+ oth->fin + oldskb->len -
-+ ip_hdrlen(oldskb) - (oth->doff<<2));
-+ tcph->seq = false;
-+ } else {
-+ needs_ack = false;
-+ tcph->seq = oth->ack_seq;
-+ tcph->ack_seq = false;
-+ }
-+
-+ /* Reset flags */
-+ ((u_int8_t *)tcph)[13] = 0;
-+ tcph->rst = true;
-+ tcph->ack = needs_ack;
-+ }
-+
-+ tcph->window = 0;
-+ tcph->urg_ptr = 0;
-+
-+ /* Adjust TCP checksum */
-+ tcph->check = 0;
-+ tcph->check = tcp_v4_check(sizeof(struct tcphdr), niph->saddr,
-+ niph->daddr, csum_partial((char *)tcph,
-+ sizeof(struct tcphdr), 0));
-+
-+ /* Set DF, id = 0 */
-+ niph->frag_off = htons(IP_DF);
-+ niph->id = 0;
-+
-+ addr_type = RTN_UNSPEC;
-+#ifdef CONFIG_BRIDGE_NETFILTER
-+ if (hook != NF_IP_FORWARD || (nskb->nf_bridge != NULL &&
-+ nskb->nf_bridge->mask & BRNF_BRIDGED))
-+#else
-+ if (hook != NF_IP_FORWARD)
-+#endif
-+ addr_type = RTN_LOCAL;
-+
-+ if (ip_route_me_harder(&nskb, addr_type))
-+ goto free_nskb;
-+
-+ nskb->ip_summed = CHECKSUM_NONE;
-+
-+ /* Adjust IP TTL */
-+ niph->ttl = dst_metric(nskb->dst, RTAX_HOPLIMIT);
-+
-+ /* Adjust IP checksum */
-+ niph->check = 0;
-+ niph->check = ip_fast_csum(skb_network_header(nskb), niph->ihl);
-+
-+ /* "Never happens" */
-+ if (nskb->len > dst_mtu(nskb->dst))
-+ goto free_nskb;
-+
-+ nf_ct_attach(nskb, oldskb);
-+
-+ NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, nskb, NULL, nskb->dst->dev,
-+ dst_output);
-+ return;
-+
-+ free_nskb:
-+ kfree_skb(nskb);
-+}
-+
-+static unsigned int delude_tg(struct sk_buff **pskb,
-+ const struct net_device *in, const struct net_device *out,
-+ unsigned int hooknum, const struct xt_target *target, const void *targinfo)
-+{
-+ /* WARNING: This code causes reentry within iptables.
-+ This means that the iptables jump stack is now crap. We
-+ must return an absolute verdict. --RR */
-+ delude_send_reset(*pskb, hooknum);
-+ return NF_DROP;
-+}
-+
-+static struct xt_target delude_tg_reg = {
-+ .name = "DELUDE",
-+ .family = AF_INET,
-+ .table = "filter",
-+ .hooks = (1 << NF_IP_LOCAL_IN) | (1 << NF_IP_FORWARD),
-+ .target = delude_tg,
-+ .proto = IPPROTO_TCP,
-+ .me = THIS_MODULE,
-+};
-+
-+static int __init delude_tg_init(void)
-+{
-+ return xt_register_target(&delude_tg_reg);
-+}
-+
-+static void __exit delude_tg_exit(void)
-+{
-+ xt_unregister_target(&delude_tg_reg);
-+}
-+
-+module_init(delude_tg_init);
-+module_exit(delude_tg_exit);
-+MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
-+MODULE_DESCRIPTION("netfilter \"DELUDE\" target");
-+MODULE_LICENSE("GPL");
-+MODULE_ALIAS("ipt_DELUDE");
---- /dev/null
-+++ b/net/netfilter/xt_portscan.c
-@@ -0,0 +1,269 @@
-+/*
-+ * portscan match for netfilter
-+ * 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 <linux/in.h>
-+#include <linux/ip.h>
-+#include <linux/module.h>
-+#include <linux/moduleparam.h>
-+#include <linux/skbuff.h>
-+#include <linux/stat.h>
-+#include <linux/tcp.h>
-+#include <linux/types.h>
-+#include <linux/version.h>
-+#include <linux/netfilter/x_tables.h>
-+#include <linux/netfilter/xt_tcpudp.h>
-+#include <net/netfilter/nf_nat_rule.h>
-+#if defined(_LOCAL)
-+# include "xt_portscan.h"
-+#elif defined(CONFIG_NETFILTER_XT_MATCH_PORTSCAN) || \
-+ defined(CONFIG_NETFILTER_XT_MATCH_PORTSCAN_MODULE)
-+# include <linux/netfilter/xt_portscan.h>
-+#else
-+# include "xt_portscan.h"
-+#endif
-+#define PFX KBUILD_MODNAME ": "
-+
-+enum {
-+ TCP_FLAGS_ALL3 = TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_SYN,
-+ TCP_FLAGS_ALL4 = TCP_FLAGS_ALL3 | TCP_FLAG_ACK,
-+ TCP_FLAGS_ALL6 = TCP_FLAGS_ALL4 | TCP_FLAG_PSH | TCP_FLAG_URG,
-+};
-+
-+/* Module parameters */
-+static unsigned int
-+ connmark_mask = ~0,
-+ packet_mask = ~0,
-+ mark_seen = 0x9,
-+ mark_synrcv = 0x1,
-+ mark_closed = 0x2,
-+ mark_synscan = 0x3,
-+ mark_estab1 = 0x4,
-+ mark_estab2 = 0x5,
-+ mark_cnscan = 0x6,
-+ mark_grscan = 0x7,
-+ mark_valid = 0x8;
-+
-+module_param(connmark_mask, uint, S_IRUGO | S_IWUSR);
-+module_param(packet_mask, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_seen, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_synrcv, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_closed, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_synscan, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_estab1, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_estab2, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_cnscan, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_grscan, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_valid, uint, S_IRUGO | S_IWUSR);
-+MODULE_PARM_DESC(connmark_mask, "only set specified bits in connection mark");
-+MODULE_PARM_DESC(packet_mask, "only set specified bits in packet mark");
-+MODULE_PARM_DESC(mark_seen, "nfmark value for packet-seen state");
-+MODULE_PARM_DESC(mark_synrcv, "connmark value for SYN Received state");
-+MODULE_PARM_DESC(mark_closed, "connmark value for closed state");
-+MODULE_PARM_DESC(mark_synscan, "connmark value for SYN Scan state");
-+MODULE_PARM_DESC(mark_estab1, "connmark value for Established-1 state");
-+MODULE_PARM_DESC(mark_estab2, "connmark value for Established-2 state");
-+MODULE_PARM_DESC(mark_cnscan, "connmark value for Connect Scan state");
-+MODULE_PARM_DESC(mark_grscan, "connmark value for Grab Scan state");
-+MODULE_PARM_DESC(mark_valid, "connmark value for Valid state");
-+
-+/* TCP flag functions */
-+static inline bool tflg_ack4(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL4) == TCP_FLAG_ACK;
-+}
-+
-+static inline bool tflg_ack6(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL6) == TCP_FLAG_ACK;
-+}
-+
-+static inline bool tflg_fin(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL3) == TCP_FLAG_FIN;
-+}
-+
-+static inline bool tflg_rst(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL3) == TCP_FLAG_RST;
-+}
-+
-+static inline bool tflg_rstack(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL4) ==
-+ (TCP_FLAG_ACK | TCP_FLAG_RST);
-+}
-+
-+static inline bool tflg_syn(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL4) == TCP_FLAG_SYN;
-+}
-+
-+static inline bool tflg_synack(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL4) ==
-+ (TCP_FLAG_SYN | TCP_FLAG_ACK);
-+}
-+
-+/* portscan functions */
-+static inline bool portscan_mt_stealth(const struct tcphdr *th)
-+{
-+ /*
-+ * "Connection refused" replies to our own probes must not be matched.
-+ */
-+ if (tflg_rstack(th))
-+ return false;
-+
-+ if (tflg_rst(th) && printk_ratelimit()) {
-+ printk(KERN_WARNING PFX "Warning: Pure RST received\n");
-+ return false;
-+ }
-+
-+ /*
-+ * -p tcp ! --syn -m conntrack --ctstate INVALID: Looking for non-start
-+ * packets that are not associated with any connection -- this will
-+ * match most scan types (NULL, XMAS, FIN) and ridiculous flag
-+ * combinations (SYN-RST, SYN-FIN, SYN-FIN-RST, FIN-RST, etc.).
-+ */
-+ return !tflg_syn(th);
-+}
-+
-+static inline unsigned int portscan_mt_full(int mark,
-+ enum ip_conntrack_info ctstate, bool loopback, const struct tcphdr *tcph,
-+ unsigned int payload_len)
-+{
-+ if (mark == mark_estab2) {
-+ /*
-+ * -m connmark --mark $ESTAB2
-+ */
-+ if (tflg_ack4(tcph) && payload_len == 0)
-+ return mark; /* keep mark */
-+ else if (tflg_rst(tcph) || tflg_fin(tcph))
-+ return mark_grscan;
-+ else
-+ return mark_valid;
-+ } else if (mark == mark_estab1) {
-+ /*
-+ * -m connmark --mark $ESTAB1
-+ */
-+ if (tflg_rst(tcph) || tflg_fin(tcph))
-+ return mark_cnscan;
-+ else if (!loopback && tflg_ack4(tcph) && payload_len == 0)
-+ return mark_estab2;
-+ else
-+ return mark_valid;
-+ } else if (mark == mark_synrcv) {
-+ /*
-+ * -m connmark --mark $SYN
-+ */
-+ if (loopback && tflg_synack(tcph))
-+ return mark; /* keep mark */
-+ else if (loopback && tflg_rstack(tcph))
-+ return mark_closed;
-+ else if (tflg_ack6(tcph))
-+ return mark_estab1;
-+ else
-+ return mark_synscan;
-+ } else if (ctstate == IP_CT_NEW && tflg_syn(tcph)) {
-+ /*
-+ * -p tcp --syn --ctstate NEW
-+ */
-+ return mark_synrcv;
-+ }
-+ return mark;
-+}
-+
-+static bool portscan_mt(const struct sk_buff *skb,
-+ const struct net_device *in, const struct net_device *out,
-+ const struct xt_match *match, const void *matchinfo, int offset,
-+ unsigned int protoff, bool *hotdrop)
-+{
-+ const struct xt_portscan_match_info *info = matchinfo;
-+ enum ip_conntrack_info ctstate;
-+ const struct tcphdr *tcph;
-+ struct nf_conn *ctdata;
-+ struct tcphdr tcph_buf;
-+
-+ tcph = skb_header_pointer(skb, protoff, sizeof(tcph_buf), &tcph_buf);
-+ if (tcph == NULL)
-+ return false;
-+
-+ /* Check for invalid packets: -m conntrack --ctstate INVALID */
-+ if ((ctdata = nf_ct_get(skb, &ctstate)) == NULL) {
-+ if (info->match_stealth)
-+ return portscan_mt_stealth(tcph);
-+ /*
-+ * If @ctdata is NULL, we cannot match the other scan
-+ * types, return.
-+ */
-+ return false;
-+ }
-+
-+ /*
-+ * If -m portscan was previously applied to this packet, the rules we
-+ * simulate must not be run through again. And for speedup, do not call
-+ * it either when the connection is already VALID.
-+ */
-+ if ((ctdata->mark & connmark_mask) == mark_valid ||
-+ (skb->mark & packet_mask) != mark_seen) {
-+ unsigned int n;
-+
-+ n = portscan_mt_full(ctdata->mark & connmark_mask, ctstate,
-+ in == &loopback_dev, tcph,
-+ skb->len - protoff - 4 * tcph->doff);
-+
-+ ctdata->mark = (ctdata->mark & ~connmark_mask) | n;
-+ ((struct sk_buff *)skb)->mark =
-+ (skb->mark & ~packet_mask) ^ mark_seen;
-+ }
-+
-+ return (info->match_syn && ctdata->mark == mark_synscan) ||
-+ (info->match_cn && ctdata->mark == mark_cnscan) ||
-+ (info->match_gr && ctdata->mark == mark_grscan);
-+}
-+
-+static bool portscan_mt_check(const char *tablename, const void *entry,
-+ const struct xt_match *match, void *matchinfo, unsigned int hook_mask)
-+{
-+ const struct xt_portscan_match_info *info = matchinfo;
-+
-+ if ((info->match_stealth & ~1) || (info->match_syn & ~1) ||
-+ (info->match_cn & ~1) || (info->match_gr & ~1)) {
-+ printk(KERN_WARNING PFX "Invalid flags\n");
-+ return false;
-+ }
-+ return true;
-+}
-+
-+static struct xt_match portscan_mt_reg __read_mostly = {
-+ .name = "portscan",
-+ .family = AF_INET,
-+ .match = portscan_mt,
-+ .checkentry = portscan_mt_check,
-+ .matchsize = sizeof(struct xt_portscan_match_info),
-+ .proto = IPPROTO_TCP,
-+ .me = THIS_MODULE,
-+};
-+
-+static int __init portscan_mt_init(void)
-+{
-+ return xt_register_match(&portscan_mt_reg);
-+}
-+
-+static void __exit portscan_mt_exit(void)
-+{
-+ xt_unregister_match(&portscan_mt_reg);
-+ return;
-+}
-+
-+module_init(portscan_mt_init);
-+module_exit(portscan_mt_exit);
-+MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
-+MODULE_DESCRIPTION("netfilter \"portscan\" match");
-+MODULE_LICENSE("GPL");
-+MODULE_ALIAS("ipt_portscan");
---- a/drivers/char/random.c
-+++ b/drivers/char/random.c
-@@ -1564,6 +1564,8 @@ __u32 secure_tcp_sequence_number(__be32
- return seq;
- }
-
-+EXPORT_SYMBOL(secure_tcp_sequence_number);
-+
- /* Generate secure starting point for ephemeral IPV4 transport port search */
- u32 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport)
- {
+++ /dev/null
---- a/net/netfilter/Kconfig
-+++ b/net/netfilter/Kconfig
-@@ -401,6 +401,23 @@ config NETFILTER_XT_TARGET_CONNSECMARK
-
- To compile it as a module, choose M here. If unsure, say N.
-
-+config NETFILTER_XT_TARGET_TARPIT
-+ tristate '"TARPIT" target support'
-+ depends on NETFILTER_XTABLES
-+ ---help---
-+ Adds a TARPIT target to iptables, which 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 does not require dedicated
-+ hardware or IPs. Any TCP port that you would normally DROP or REJECT
-+ can instead become a tarpit.
-+
- config NETFILTER_XT_TARGET_TCPMSS
- tristate '"TCPMSS" target support'
- depends on NETFILTER_XTABLES && (IPV6 || IPV6=n)
---- a/net/netfilter/Makefile
-+++ b/net/netfilter/Makefile
-@@ -47,6 +47,7 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_NFLOG)
- obj-$(CONFIG_NETFILTER_XT_TARGET_NOTRACK) += xt_NOTRACK.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_TRACE) += xt_TRACE.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_SECMARK) += xt_SECMARK.o
-+obj-$(CONFIG_NETFILTER_XT_TARGET_TARPIT) += xt_TARPIT.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_TCPMSS) += xt_TCPMSS.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_CONNSECMARK) += xt_CONNSECMARK.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_CHAOS) += xt_CHAOS.o
---- /dev/null
-+++ b/net/netfilter/xt_TARPIT.c
-@@ -0,0 +1,280 @@
-+/*
-+ * Kernel module to capture and hold incoming TCP connections using
-+ * no local per-connection resources.
-+ *
-+ * Based on ipt_REJECT.c and offering functionality similar to
-+ * LaBrea <http://www.hackbusters.net/LaBrea/>.
-+ *
-+ * Copyright (c) 2002 Aaron Hopkins <tools@die.net>
-+ *
-+ * This program is free software; you can redistribute it and/or modify
-+ * it under the terms of the GNU General Public License as published by
-+ * the Free Software Foundation; either version 2 of the License, or
-+ * (at your option) any later version.
-+ *
-+ * This program is distributed in the hope that it will be useful,
-+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
-+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-+ * GNU General Public License for more details.
-+ *
-+ * You should have received a copy of the GNU General Public License
-+ * along with this program; if not, write to the Free Software
-+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-+ *
-+ * Goal:
-+ * - Allow incoming TCP connections to be established.
-+ * - Passing data should result in the connection being switched to the
-+ * persist state (0 byte window), in which the remote side stops sending
-+ * data and asks to continue every 60 seconds.
-+ * - Attempts to shut down the connection should be ignored completely, so
-+ * the remote side ends up having to time it out.
-+ *
-+ * This means:
-+ * - Reply to TCP SYN,!ACK,!RST,!FIN with SYN-ACK, window 5 bytes
-+ * - Reply to TCP SYN,ACK,!RST,!FIN with RST to prevent spoofing
-+ * - Reply to TCP !SYN,!RST,!FIN with ACK, window 0 bytes, rate-limited
-+ */
-+
-+#include <linux/version.h>
-+#include <linux/module.h>
-+#include <linux/skbuff.h>
-+#include <linux/ip.h>
-+#include <net/ip.h>
-+#include <net/tcp.h>
-+#include <net/icmp.h>
-+struct in_device;
-+#include <net/route.h>
-+#include <linux/random.h>
-+#include <linux/netfilter_ipv4/ip_tables.h>
-+
-+#if 0
-+#define DEBUGP printk
-+#else
-+#define DEBUGP(format, args...)
-+#endif
-+
-+/* Stolen from ip_finish_output2 */
-+static int ip_direct_send(struct sk_buff *skb)
-+{
-+ struct dst_entry *dst = skb->dst;
-+
-+ if (dst->hh != NULL)
-+ return neigh_hh_output(dst->hh, skb);
-+ else if (dst->neighbour != NULL)
-+ return dst->neighbour->output(skb);
-+
-+ if (net_ratelimit())
-+ printk(KERN_DEBUG "TARPIT ip_direct_send: no header cache and no neighbor!\n");
-+
-+ kfree_skb(skb);
-+ return -EINVAL;
-+}
-+
-+
-+/* Send reply */
-+static void tarpit_tcp(const struct sk_buff *oskb, struct rtable *ort,
-+ unsigned int local)
-+{
-+ struct sk_buff *nskb;
-+ struct rtable *nrt;
-+ struct tcphdr *otcph, *ntcph;
-+ struct flowi fl = {};
-+ unsigned int otcplen;
-+ u_int16_t tmp;
-+
-+ const struct iphdr *oiph = ip_hdr(oskb);
-+ struct iphdr *niph;
-+
-+ /* A truncated TCP header is not going to be useful */
-+ if (oskb->len < ip_hdrlen(oskb) + sizeof(struct tcphdr))
-+ return;
-+
-+ otcph = (void *)oiph + ip_hdrlen(oskb);
-+ otcplen = oskb->len - ip_hdrlen(oskb);
-+
-+ /* No replies for RST or FIN */
-+ if (otcph->rst || otcph->fin)
-+ return;
-+
-+ /* No reply to !SYN,!ACK. Rate-limit replies to !SYN,ACKs */
-+ if (!otcph->syn && (!otcph->ack || !xrlim_allow(&ort->u.dst, 1*HZ)))
-+ return;
-+
-+ /* Check checksum. */
-+ if (tcp_v4_check(otcplen, oiph->saddr, oiph->daddr,
-+ csum_partial((char *)otcph, otcplen, 0)) != 0)
-+ return;
-+
-+ /*
-+ * Copy skb (even if skb is about to be dropped, we cannot just
-+ * clone it because there may be other things, such as tcpdump,
-+ * interested in it)
-+ */
-+ nskb = skb_copy(oskb, GFP_ATOMIC);
-+ if (nskb == NULL)
-+ return;
-+
-+ niph = ip_hdr(nskb);
-+
-+ /* This packet will not be the same as the other: clear nf fields */
-+ nf_conntrack_put(nskb->nfct);
-+ nskb->nfct = NULL;
-+#ifdef CONFIG_NETFILTER_DEBUG
-+ nskb->nf_debug = 0;
-+#endif
-+
-+ ntcph = (void *)niph + ip_hdrlen(nskb);
-+
-+ /* Truncate to length (no data) */
-+ ntcph->doff = sizeof(struct tcphdr)/4;
-+ skb_trim(nskb, ip_hdrlen(nskb) + sizeof(struct tcphdr));
-+ niph->tot_len = htons(nskb->len);
-+
-+ /* Swap source and dest */
-+ niph->daddr = xchg(&niph->saddr, niph->daddr);
-+ tmp = ntcph->source;
-+ ntcph->source = ntcph->dest;
-+ ntcph->dest = tmp;
-+
-+ /* Use supplied sequence number or make a new one */
-+ ntcph->seq = otcph->ack ? otcph->ack_seq
-+ : htonl(secure_tcp_sequence_number(niph->saddr,
-+ niph->daddr,
-+ ntcph->source,
-+ ntcph->dest));
-+
-+ /* Our SYN-ACKs must have a >0 window */
-+ ntcph->window = (otcph->syn && !otcph->ack) ? htons(5) : 0;
-+
-+ ntcph->urg_ptr = 0;
-+
-+ /* Reset flags */
-+ ((u_int8_t *)ntcph)[13] = 0;
-+
-+ if (otcph->syn && otcph->ack) {
-+ ntcph->rst = 1;
-+ ntcph->ack_seq = 0;
-+ } else {
-+ ntcph->syn = otcph->syn;
-+ ntcph->ack = 1;
-+ ntcph->ack_seq = htonl(ntohl(otcph->seq) + otcph->syn);
-+ }
-+
-+ /* Adjust TCP checksum */
-+ ntcph->check = 0;
-+ ntcph->check = tcp_v4_check(sizeof(struct tcphdr),
-+ niph->saddr,
-+ niph->daddr,
-+ csum_partial((char *)ntcph,
-+ sizeof(struct tcphdr), 0));
-+
-+ fl.nl_u.ip4_u.daddr = niph->daddr;
-+ fl.nl_u.ip4_u.saddr = local ? niph->saddr : 0;
-+ fl.nl_u.ip4_u.tos = RT_TOS(niph->tos) | RTO_CONN;
-+ fl.oif = 0;
-+
-+ if (ip_route_output_key(&nrt, &fl))
-+ goto free_nskb;
-+
-+ dst_release(nskb->dst);
-+ nskb->dst = &nrt->u.dst;
-+
-+ /* Adjust IP TTL */
-+ niph->ttl = dst_metric(nskb->dst, RTAX_HOPLIMIT);
-+
-+ /* Set DF, id = 0 */
-+ niph->frag_off = htons(IP_DF);
-+ niph->id = 0;
-+
-+ /* Adjust IP checksum */
-+ niph->check = 0;
-+ niph->check = ip_fast_csum((unsigned char *)niph, niph->ihl);
-+
-+ /* "Never happens" */
-+ if (nskb->len > dst_mtu(nskb->dst))
-+ goto free_nskb;
-+
-+ ip_direct_send(nskb);
-+ return;
-+
-+ free_nskb:
-+ kfree_skb(nskb);
-+}
-+
-+static unsigned int xt_tarpit_target(struct sk_buff **pskb,
-+ const struct net_device *in,
-+ const struct net_device *out,
-+ unsigned int hooknum,
-+ const struct xt_target *target,
-+ const void *targinfo)
-+{
-+ const struct sk_buff *skb = *pskb;
-+ const struct iphdr *iph = ip_hdr(skb);
-+ struct rtable *rt = (void *)skb->dst;
-+
-+ /* Do we have an input route cache entry? */
-+ if (rt == NULL)
-+ return NF_DROP;
-+
-+ /* No replies to physical multicast/broadcast */
-+ if (skb->pkt_type != PACKET_HOST && skb->pkt_type != PACKET_OTHERHOST)
-+ return NF_DROP;
-+
-+ /* Now check at the protocol level */
-+ if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
-+ return NF_DROP;
-+
-+ /*
-+ * Our naive response construction does not deal with IP
-+ * options, and probably should not try.
-+ */
-+ if (iph->ihl * 4 != sizeof(struct iphdr))
-+ return NF_DROP;
-+
-+ /* We are not interested in fragments */
-+ if (iph->frag_off & htons(IP_OFFSET))
-+ return NF_DROP;
-+
-+ tarpit_tcp(skb, rt, hooknum == NF_IP_LOCAL_IN);
-+ return NF_DROP;
-+}
-+
-+static bool xt_tarpit_check(const char *tablename, const void *entry,
-+ const struct xt_target *target, void *targinfo,
-+ unsigned int hook_mask)
-+{
-+ bool invalid;
-+
-+ if (strcmp(tablename, "raw") == 0 && hook_mask == NF_IP_PRE_ROUTING)
-+ return true;
-+ if (strcmp(tablename, "filter") != 0)
-+ return false;
-+ invalid = hook_mask & ~((1 << NF_IP_LOCAL_IN) | (1 << NF_IP_FORWARD));
-+ return !invalid;
-+}
-+
-+static struct xt_target xt_tarpit_reg = {
-+ .name = "TARPIT",
-+ .family = AF_INET,
-+ .proto = IPPROTO_TCP,
-+ .target = xt_tarpit_target,
-+ .checkentry = xt_tarpit_check,
-+ .me = THIS_MODULE,
-+};
-+
-+static int __init xt_tarpit_init(void)
-+{
-+ return xt_register_target(&xt_tarpit_reg);
-+}
-+
-+static void __exit xt_tarpit_exit(void)
-+{
-+ xt_unregister_target(&xt_tarpit_reg);
-+}
-+
-+module_init(xt_tarpit_init);
-+module_exit(xt_tarpit_exit);
-+MODULE_DESCRIPTION("netfilter xt_TARPIT target module");
-+MODULE_AUTHOR("Jan Engelhardt <jengelh@gmx.de>");
-+MODULE_LICENSE("GPL");
-+MODULE_ALIAS("ipt_TARPIT");
help
H.323 is a VoIP signalling protocol from ITU-T. As one of the most
important VoIP protocols, it is widely used by voice hardware and
-@@ -420,7 +420,7 @@ config NETFILTER_XT_TARGET_TARPIT
+@@ -387,7 +387,7 @@ config NETFILTER_XT_TARGET_CONNSECMARK
config NETFILTER_XT_TARGET_TCPMSS
tristate '"TCPMSS" target support'
+++ /dev/null
---- a/include/linux/netfilter/Kbuild
-+++ b/include/linux/netfilter/Kbuild
-@@ -3,6 +3,7 @@ header-y += nf_conntrack_tuple_common.h
- header-y += nfnetlink_conntrack.h
- header-y += nfnetlink_log.h
- header-y += nfnetlink_queue.h
-+header-y += xt_CHAOS.h
- header-y += xt_CLASSIFY.h
- header-y += xt_CONNMARK.h
- header-y += xt_CONNSECMARK.h
---- /dev/null
-+++ b/include/linux/netfilter/oot_conntrack.h
-@@ -0,0 +1,5 @@
-+#if defined(CONFIG_IP_NF_CONNTRACK) || defined(CONFIG_IP_NF_CONNTRACK_MODULE)
-+# include <linux/netfilter_ipv4/ip_conntrack.h>
-+#else /* linux-2.6.20+ */
-+# include <net/netfilter/nf_nat_rule.h>
-+#endif
---- /dev/null
-+++ b/include/linux/netfilter/oot_trans.h
-@@ -0,0 +1,14 @@
-+/* Out of tree workarounds */
-+#include <linux/version.h>
-+#if LINUX_VERSION_CODE <= KERNEL_VERSION(2, 6, 18)
-+# define HAVE_MATCHINFOSIZE 1
-+# define HAVE_TARGUSERINFO 1
-+# define HAVE_TARGINFOSIZE 1
-+#endif
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 20)
-+# define nfmark mark
-+#endif
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 21)
-+# define tcp_v4_check(tcph, tcph_sz, s, d, csp) \
-+ tcp_v4_check((tcph_sz), (s), (d), (csp))
-+#endif
---- /dev/null
-+++ b/include/linux/netfilter/xt_CHAOS.h
-@@ -0,0 +1,14 @@
-+#ifndef _LINUX_NETFILTER_XT_CHAOS_H
-+#define _LINUX_NETFILTER_XT_CHAOS_H 1
-+
-+enum xt_chaos_target_variant {
-+ XTCHAOS_NORMAL,
-+ XTCHAOS_TARPIT,
-+ XTCHAOS_DELUDE,
-+};
-+
-+struct xt_chaos_target_info {
-+ uint8_t variant;
-+};
-+
-+#endif /* _LINUX_NETFILTER_XT_CHAOS_H */
---- /dev/null
-+++ b/include/linux/netfilter/xt_portscan.h
-@@ -0,0 +1,8 @@
-+#ifndef _LINUX_NETFILTER_XT_PORTSCAN_H
-+#define _LINUX_NETFILTER_XT_PORTSCAN_H 1
-+
-+struct xt_portscan_match_info {
-+ uint8_t match_stealth, match_syn, match_cn, match_gr;
-+};
-+
-+#endif /* _LINUX_NETFILTER_XT_PORTSCAN_H */
---- /dev/null
-+++ b/net/netfilter/find_match.c
-@@ -0,0 +1,39 @@
-+/*
-+ xt_request_find_match
-+ by Jan Engelhardt <jengelh [at] gmx de>, 2006 - 2007
-+
-+ Based upon linux-2.6.18.5/net/netfilter/x_tables.c:
-+ Copyright (C) 2006-2006 Harald Welte <laforge@netfilter.org>
-+ This program is free software; you can redistribute it and/or modify
-+ it under the terms of the GNU General Public License version 2 as
-+ published by the Free Software Foundation.
-+*/
-+#include <linux/err.h>
-+#include <linux/netfilter_arp.h>
-+#include <linux/socket.h>
-+#include <linux/netfilter/x_tables.h>
-+
-+/*
-+ * Yeah this code is sub-optimal, but the function is missing in
-+ * mainline so far. -jengelh
-+ */
-+static struct xt_match *xt_request_find_match_lo(int af, const char *name,
-+ u8 revision)
-+{
-+ static const char *const xt_prefix[] = {
-+ [AF_INET] = "ip",
-+ [AF_INET6] = "ip6",
-+ [NF_ARP] = "arp",
-+ };
-+ struct xt_match *match;
-+
-+ match = try_then_request_module(xt_find_match(af, name, revision),
-+ "%st_%s", xt_prefix[af], name);
-+ if (IS_ERR(match) || match == NULL)
-+ return NULL;
-+
-+ return match;
-+}
-+
-+/* In case it goes into mainline, let this out-of-tree package compile */
-+#define xt_request_find_match xt_request_find_match_lo
---- a/net/netfilter/Kconfig
-+++ b/net/netfilter/Kconfig
-@@ -265,6 +265,14 @@ config NETFILTER_XTABLES
-
- # alphabetically ordered list of targets
-
-+config NETFILTER_XT_TARGET_CHAOS
-+ tristate '"CHAOS" target support'
-+ depends on NETFILTER_XTABLES
-+ help
-+ This option adds a `CHAOS' target.
-+
-+ To compile it as a module, choose M here. If unsure, say N.
-+
- config NETFILTER_XT_TARGET_CLASSIFY
- tristate '"CLASSIFY" target support'
- depends on NETFILTER_XTABLES
-@@ -292,6 +300,14 @@ config NETFILTER_XT_TARGET_CONNMARK
- <file:Documentation/kbuild/modules.txt>. The module will be called
- ipt_CONNMARK.ko. If unsure, say `N'.
-
-+config NETFILTER_XT_TARGET_DELUDE
-+ tristate '"DELUDE" target support'
-+ depends on NETFILTER_XTABLES
-+ help
-+ This option adds a `DELUDE' target.
-+
-+ To compile it as a module, choose M here. If unsure, say N.
-+
- config NETFILTER_XT_TARGET_DSCP
- tristate '"DSCP" target support'
- depends on NETFILTER_XTABLES
-@@ -556,6 +572,14 @@ config NETFILTER_XT_MATCH_POLICY
-
- To compile it as a module, choose M here. If unsure, say N.
-
-+config NETFILTER_XT_MATCH_PORTSCAN
-+ tristate '"portscan" match support'
-+ depends on NETFILTER_XTABLES
-+ help
-+ This option adds a 'portscan' match support.
-+
-+ To compile it as a module, choose M here. If unsure, say N.
-+
- config NETFILTER_XT_MATCH_MULTIPORT
- tristate "Multiple port match support"
- depends on NETFILTER_XTABLES
---- a/net/netfilter/Makefile
-+++ b/net/netfilter/Makefile
-@@ -49,6 +49,8 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_NOTRACK
- obj-$(CONFIG_NETFILTER_XT_TARGET_SECMARK) += xt_SECMARK.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_TCPMSS) += xt_TCPMSS.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_TRACE) += xt_TRACE.o
-+obj-$(CONFIG_NETFILTER_XT_TARGET_CHAOS) += xt_CHAOS.o
-+obj-$(CONFIG_NETFILTER_XT_TARGET_DELUDE) += xt_DELUDE.o
-
- # matches
- obj-$(CONFIG_NETFILTER_XT_MATCH_COMMENT) += xt_comment.o
-@@ -79,3 +81,4 @@ obj-$(CONFIG_NETFILTER_XT_MATCH_STRING)
- obj-$(CONFIG_NETFILTER_XT_MATCH_TCPMSS) += xt_tcpmss.o
- obj-$(CONFIG_NETFILTER_XT_MATCH_TIME) += xt_time.o
- obj-$(CONFIG_NETFILTER_XT_MATCH_U32) += xt_u32.o
-+obj-$(CONFIG_NETFILTER_XT_MATCH_PORTSCAN) += xt_portscan.o
---- /dev/null
-+++ b/net/netfilter/xt_CHAOS.c
-@@ -0,0 +1,200 @@
-+/*
-+ * CHAOS target for netfilter
-+ * 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 <linux/icmp.h>
-+#include <linux/in.h>
-+#include <linux/ip.h>
-+#include <linux/module.h>
-+#include <linux/skbuff.h>
-+#include <linux/stat.h>
-+#include <linux/netfilter/x_tables.h>
-+#include <linux/netfilter/xt_tcpudp.h>
-+#include <linux/netfilter_ipv4/ipt_REJECT.h>
-+#include <net/ip.h>
-+#if defined(_LOCAL)
-+# include "xt_CHAOS.h"
-+# include "find_match.c"
-+#elif defined(CONFIG_NETFILTER_XT_TARGET_CHAOS) || \
-+ defined(CONFIG_NETFILTER_XT_TARGET_CHAOS_MODULE)
-+# include <linux/netfilter/xt_CHAOS.h>
-+# include "find_match.c"
-+#else
-+# include "xt_CHAOS.h"
-+# include "find_match.c"
-+#endif
-+#define PFX KBUILD_MODNAME ": "
-+
-+/* Module parameters */
-+static unsigned int reject_percentage = ~0U * .01;
-+static unsigned int delude_percentage = ~0U * .0101;
-+module_param(reject_percentage, uint, S_IRUGO | S_IWUSR);
-+module_param(delude_percentage, uint, S_IRUGO | S_IWUSR);
-+
-+/* References to other matches/targets */
-+static struct xt_match *xm_tcp;
-+static struct xt_target *xt_delude, *xt_reject, *xt_tarpit;
-+
-+static int have_delude, have_tarpit;
-+
-+/* Static data for other matches/targets */
-+static const struct ipt_reject_info reject_params = {
-+ .with = ICMP_HOST_UNREACH,
-+};
-+
-+static const struct xt_tcp tcp_params = {
-+ .spts = {0, ~0},
-+ .dpts = {0, ~0},
-+};
-+
-+/* CHAOS functions */
-+static void xt_chaos_total(const struct xt_chaos_target_info *info,
-+ struct sk_buff *skb, const struct net_device *in,
-+ const struct net_device *out, unsigned int hooknum)
-+{
-+ const struct iphdr *iph = ip_hdr(skb);
-+ const int protoff = 4 * iph->ihl;
-+ const int offset = ntohs(iph->frag_off) & IP_OFFSET;
-+ const struct xt_target *destiny;
-+ bool hotdrop = false, ret;
-+
-+ ret = xm_tcp->match(skb, in, out, xm_tcp, &tcp_params,
-+ offset, protoff, &hotdrop);
-+ if (!ret || hotdrop || (unsigned int)net_random() > delude_percentage)
-+ return;
-+
-+ destiny = (info->variant == XTCHAOS_TARPIT) ? xt_tarpit : xt_delude;
-+ destiny->target(skb, in, out, hooknum, destiny, NULL);
-+ return;
-+}
-+
-+static unsigned int chaos_tg(struct sk_buff *skb,
-+ const struct net_device *in, const struct net_device *out,
-+ unsigned int hooknum, const struct xt_target *target, const void *targinfo)
-+{
-+ /*
-+ * Equivalent to:
-+ * -A chaos -m statistic --mode random --probability \
-+ * $reject_percentage -j REJECT --reject-with host-unreach;
-+ * -A chaos -p tcp -m statistic --mode random --probability \
-+ * $delude_percentage -j DELUDE;
-+ * -A chaos -j DROP;
-+ */
-+ const struct xt_chaos_target_info *info = targinfo;
-+ const struct iphdr *iph = ip_hdr(skb);
-+
-+ if ((unsigned int)net_random() <= reject_percentage)
-+ return xt_reject->target(skb, in, out, hooknum, target,
-+ &reject_params);
-+
-+ /* TARPIT/DELUDE may not be called from the OUTPUT chain */
-+ if (iph->protocol == IPPROTO_TCP &&
-+ info->variant != XTCHAOS_NORMAL && hooknum != NF_IP_LOCAL_OUT)
-+ xt_chaos_total(info, skb, in, out, hooknum);
-+
-+ return NF_DROP;
-+}
-+
-+static bool chaos_tg_check(const char *tablename, const void *entry,
-+ const struct xt_target *target, void *targinfo, unsigned int hook_mask)
-+{
-+ const struct xt_chaos_target_info *info = targinfo;
-+
-+ if (info->variant == XTCHAOS_DELUDE && !have_delude) {
-+ printk(KERN_WARNING PFX "Error: Cannot use --delude when "
-+ "DELUDE module not available\n");
-+ return false;
-+ }
-+ if (info->variant == XTCHAOS_TARPIT && !have_tarpit) {
-+ printk(KERN_WARNING PFX "Error: Cannot use --tarpit when "
-+ "TARPIT module not available\n");
-+ return false;
-+ }
-+
-+ return true;
-+}
-+
-+static struct xt_target chaos_tg_reg = {
-+ .name = "CHAOS",
-+ .family = AF_INET,
-+ .table = "filter",
-+ .hooks = (1 << NF_IP_LOCAL_IN) | (1 << NF_IP_FORWARD) |
-+ (1 << NF_IP_LOCAL_OUT),
-+ .checkentry = chaos_tg_check,
-+ .target = chaos_tg,
-+ .targetsize = sizeof(struct xt_chaos_target_info),
-+ .me = THIS_MODULE,
-+};
-+
-+static int __init chaos_tg_init(void)
-+{
-+ int ret = -EINVAL;
-+
-+ xm_tcp = xt_request_find_match(AF_INET, "tcp", 0);
-+ if (xm_tcp == NULL) {
-+ printk(KERN_WARNING PFX "Error: Could not find or load "
-+ "\"tcp\" match\n");
-+ return -EINVAL;
-+ }
-+
-+ xt_reject = xt_request_find_target(AF_INET, "REJECT", 0);
-+ if (xt_reject == NULL) {
-+ printk(KERN_WARNING PFX "Error: Could not find or load "
-+ "\"REJECT\" target\n");
-+ goto out2;
-+ }
-+
-+ xt_tarpit = xt_request_find_target(AF_INET, "TARPIT", 0);
-+ have_tarpit = xt_tarpit != NULL;
-+ if (!have_tarpit)
-+ printk(KERN_WARNING PFX "Warning: Could not find or load "
-+ "\"TARPIT\" target\n");
-+
-+ xt_delude = xt_request_find_target(AF_INET, "DELUDE", 0);
-+ have_delude = xt_delude != NULL;
-+ if (!have_delude)
-+ printk(KERN_WARNING PFX "Warning: Could not find or load "
-+ "\"DELUDE\" target\n");
-+
-+ if ((ret = xt_register_target(&chaos_tg_reg)) != 0) {
-+ printk(KERN_WARNING PFX "xt_register_target returned "
-+ "error %d\n", ret);
-+ goto out3;
-+ }
-+
-+ return 0;
-+
-+ out3:
-+ if (have_delude)
-+ module_put(xt_delude->me);
-+ if (have_tarpit)
-+ module_put(xt_tarpit->me);
-+ module_put(xt_reject->me);
-+ out2:
-+ module_put(xm_tcp->me);
-+ return ret;
-+}
-+
-+static void __exit chaos_tg_exit(void)
-+{
-+ xt_unregister_target(&chaos_tg_reg);
-+ module_put(xm_tcp->me);
-+ module_put(xt_reject->me);
-+ if (have_delude)
-+ module_put(xt_delude->me);
-+ if (have_tarpit)
-+ module_put(xt_tarpit->me);
-+ return;
-+}
-+
-+module_init(chaos_tg_init);
-+module_exit(chaos_tg_exit);
-+MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
-+MODULE_DESCRIPTION("netfilter \"CHAOS\" target");
-+MODULE_LICENSE("GPL");
-+MODULE_ALIAS("ipt_CHAOS");
---- /dev/null
-+++ b/net/netfilter/xt_DELUDE.c
-@@ -0,0 +1,197 @@
-+/*
-+ * DELUDE target
-+ * Copyright © CC Computer Consultants GmbH, 2007
-+ * Contact: Jan Engelhardt <jengelh@computergmbh.de>
-+ *
-+ * Based upon linux-2.6.18.5/net/ipv4/netfilter/ipt_REJECT.c:
-+ * (C) 1999-2001 Paul `Rusty' Russell
-+ * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
-+ *
-+ * xt_DELUDE acts like REJECT, but does reply with SYN-ACK on SYN.
-+ *
-+ * This program is free software; you can redistribute it and/or modify
-+ * it under the terms of the GNU General Public License version 2 as
-+ * published by the Free Software Foundation.
-+ */
-+#include <linux/module.h>
-+#include <linux/skbuff.h>
-+#include <linux/ip.h>
-+#include <linux/tcp.h>
-+#include <linux/netfilter/x_tables.h>
-+#ifdef CONFIG_BRIDGE_NETFILTER
-+# include <linux/netfilter_bridge.h>
-+#endif
-+#include <net/tcp.h>
-+#define PFX KBUILD_MODNAME ": "
-+
-+static void delude_send_reset(struct sk_buff *oldskb, unsigned int hook)
-+{
-+ struct tcphdr _otcph, *oth, *tcph;
-+ unsigned int addr_type;
-+ struct sk_buff *nskb;
-+ u_int16_t tmp_port;
-+ u_int32_t tmp_addr;
-+ struct iphdr *niph;
-+ bool needs_ack;
-+
-+ /* IP header checks: fragment. */
-+ if (ip_hdr(oldskb)->frag_off & htons(IP_OFFSET))
-+ return;
-+
-+ oth = skb_header_pointer(oldskb, ip_hdrlen(oldskb),
-+ sizeof(_otcph), &_otcph);
-+ if (oth == NULL)
-+ return;
-+
-+ /* No RST for RST. */
-+ if (oth->rst)
-+ return;
-+
-+ /* Check checksum */
-+ if (nf_ip_checksum(oldskb, hook, ip_hdrlen(oldskb), IPPROTO_TCP))
-+ return;
-+
-+ /* We need a linear, writeable skb. We also need to expand
-+ headroom in case hh_len of incoming interface < hh_len of
-+ outgoing interface */
-+ nskb = skb_copy_expand(oldskb, LL_MAX_HEADER, skb_tailroom(oldskb),
-+ GFP_ATOMIC);
-+ if (!nskb)
-+ return;
-+
-+ /* This packet will not be the same as the other: clear nf fields */
-+ nf_reset(nskb);
-+ nskb->mark = 0;
-+ skb_init_secmark(nskb);
-+
-+ skb_shinfo(nskb)->gso_size = 0;
-+ skb_shinfo(nskb)->gso_segs = 0;
-+ skb_shinfo(nskb)->gso_type = 0;
-+
-+ tcph = (struct tcphdr *)(skb_network_header(nskb) + ip_hdrlen(nskb));
-+
-+ /* Swap source and dest */
-+ niph = ip_hdr(nskb);
-+ tmp_addr = niph->saddr;
-+ niph->saddr = niph->daddr;
-+ niph->daddr = tmp_addr;
-+ tmp_port = tcph->source;
-+ tcph->source = tcph->dest;
-+ tcph->dest = tmp_port;
-+
-+ /* Truncate to length (no data) */
-+ tcph->doff = sizeof(struct tcphdr) / 4;
-+ skb_trim(nskb, ip_hdrlen(nskb) + sizeof(struct tcphdr));
-+ niph->tot_len = htons(nskb->len);
-+
-+ if (oth->syn && !oth->ack && !oth->rst && !oth->fin) {
-+ /* DELUDE essential part */
-+ tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn + oth->fin +
-+ oldskb->len - ip_hdrlen(oldskb) -
-+ (oth->doff << 2));
-+ tcph->seq = false;
-+ tcph->ack = true;
-+ } else {
-+ if (!tcph->ack) {
-+ needs_ack = true;
-+ tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn +
-+ oth->fin + oldskb->len -
-+ ip_hdrlen(oldskb) - (oth->doff<<2));
-+ tcph->seq = false;
-+ } else {
-+ needs_ack = false;
-+ tcph->seq = oth->ack_seq;
-+ tcph->ack_seq = false;
-+ }
-+
-+ /* Reset flags */
-+ ((u_int8_t *)tcph)[13] = 0;
-+ tcph->rst = true;
-+ tcph->ack = needs_ack;
-+ }
-+
-+ tcph->window = 0;
-+ tcph->urg_ptr = 0;
-+
-+ /* Adjust TCP checksum */
-+ tcph->check = 0;
-+ tcph->check = tcp_v4_check(sizeof(struct tcphdr), niph->saddr,
-+ niph->daddr, csum_partial((char *)tcph,
-+ sizeof(struct tcphdr), 0));
-+
-+ /* Set DF, id = 0 */
-+ niph->frag_off = htons(IP_DF);
-+ niph->id = 0;
-+
-+ addr_type = RTN_UNSPEC;
-+#ifdef CONFIG_BRIDGE_NETFILTER
-+ if (hook != NF_IP_FORWARD || (nskb->nf_bridge != NULL &&
-+ nskb->nf_bridge->mask & BRNF_BRIDGED))
-+#else
-+ if (hook != NF_IP_FORWARD)
-+#endif
-+ addr_type = RTN_LOCAL;
-+
-+ if (ip_route_me_harder(nskb, addr_type))
-+ goto free_nskb;
-+
-+ nskb->ip_summed = CHECKSUM_NONE;
-+
-+ /* Adjust IP TTL */
-+ niph->ttl = dst_metric(nskb->dst, RTAX_HOPLIMIT);
-+
-+ /* Adjust IP checksum */
-+ niph->check = 0;
-+ niph->check = ip_fast_csum(skb_network_header(nskb), niph->ihl);
-+
-+ /* "Never happens" */
-+ if (nskb->len > dst_mtu(nskb->dst))
-+ goto free_nskb;
-+
-+ nf_ct_attach(nskb, oldskb);
-+
-+ NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, nskb, NULL, nskb->dst->dev,
-+ dst_output);
-+ return;
-+
-+ free_nskb:
-+ kfree_skb(nskb);
-+}
-+
-+static unsigned int delude_tg(struct sk_buff *skb,
-+ const struct net_device *in, const struct net_device *out,
-+ unsigned int hooknum, const struct xt_target *target, const void *targinfo)
-+{
-+ /* WARNING: This code causes reentry within iptables.
-+ This means that the iptables jump stack is now crap. We
-+ must return an absolute verdict. --RR */
-+ delude_send_reset(skb, hooknum);
-+ return NF_DROP;
-+}
-+
-+static struct xt_target delude_tg_reg = {
-+ .name = "DELUDE",
-+ .family = AF_INET,
-+ .table = "filter",
-+ .hooks = (1 << NF_IP_LOCAL_IN) | (1 << NF_IP_FORWARD),
-+ .target = delude_tg,
-+ .proto = IPPROTO_TCP,
-+ .me = THIS_MODULE,
-+};
-+
-+static int __init delude_tg_init(void)
-+{
-+ return xt_register_target(&delude_tg_reg);
-+}
-+
-+static void __exit delude_tg_exit(void)
-+{
-+ xt_unregister_target(&delude_tg_reg);
-+}
-+
-+module_init(delude_tg_init);
-+module_exit(delude_tg_exit);
-+MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
-+MODULE_DESCRIPTION("netfilter \"DELUDE\" target");
-+MODULE_LICENSE("GPL");
-+MODULE_ALIAS("ipt_DELUDE");
---- /dev/null
-+++ b/net/netfilter/xt_portscan.c
-@@ -0,0 +1,269 @@
-+/*
-+ * portscan match for netfilter
-+ * 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 <linux/in.h>
-+#include <linux/ip.h>
-+#include <linux/module.h>
-+#include <linux/moduleparam.h>
-+#include <linux/skbuff.h>
-+#include <linux/stat.h>
-+#include <linux/tcp.h>
-+#include <linux/types.h>
-+#include <linux/version.h>
-+#include <linux/netfilter/x_tables.h>
-+#include <linux/netfilter/xt_tcpudp.h>
-+#include <net/netfilter/nf_nat_rule.h>
-+#if defined(_LOCAL)
-+# include "xt_portscan.h"
-+#elif defined(CONFIG_NETFILTER_XT_MATCH_PORTSCAN) || \
-+ defined(CONFIG_NETFILTER_XT_MATCH_PORTSCAN_MODULE)
-+# include <linux/netfilter/xt_portscan.h>
-+#else
-+# include "xt_portscan.h"
-+#endif
-+#define PFX KBUILD_MODNAME ": "
-+
-+enum {
-+ TCP_FLAGS_ALL3 = TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_SYN,
-+ TCP_FLAGS_ALL4 = TCP_FLAGS_ALL3 | TCP_FLAG_ACK,
-+ TCP_FLAGS_ALL6 = TCP_FLAGS_ALL4 | TCP_FLAG_PSH | TCP_FLAG_URG,
-+};
-+
-+/* Module parameters */
-+static unsigned int
-+ connmark_mask = ~0,
-+ packet_mask = ~0,
-+ mark_seen = 0x9,
-+ mark_synrcv = 0x1,
-+ mark_closed = 0x2,
-+ mark_synscan = 0x3,
-+ mark_estab1 = 0x4,
-+ mark_estab2 = 0x5,
-+ mark_cnscan = 0x6,
-+ mark_grscan = 0x7,
-+ mark_valid = 0x8;
-+
-+module_param(connmark_mask, uint, S_IRUGO | S_IWUSR);
-+module_param(packet_mask, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_seen, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_synrcv, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_closed, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_synscan, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_estab1, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_estab2, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_cnscan, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_grscan, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_valid, uint, S_IRUGO | S_IWUSR);
-+MODULE_PARM_DESC(connmark_mask, "only set specified bits in connection mark");
-+MODULE_PARM_DESC(packet_mask, "only set specified bits in packet mark");
-+MODULE_PARM_DESC(mark_seen, "nfmark value for packet-seen state");
-+MODULE_PARM_DESC(mark_synrcv, "connmark value for SYN Received state");
-+MODULE_PARM_DESC(mark_closed, "connmark value for closed state");
-+MODULE_PARM_DESC(mark_synscan, "connmark value for SYN Scan state");
-+MODULE_PARM_DESC(mark_estab1, "connmark value for Established-1 state");
-+MODULE_PARM_DESC(mark_estab2, "connmark value for Established-2 state");
-+MODULE_PARM_DESC(mark_cnscan, "connmark value for Connect Scan state");
-+MODULE_PARM_DESC(mark_grscan, "connmark value for Grab Scan state");
-+MODULE_PARM_DESC(mark_valid, "connmark value for Valid state");
-+
-+/* TCP flag functions */
-+static inline bool tflg_ack4(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL4) == TCP_FLAG_ACK;
-+}
-+
-+static inline bool tflg_ack6(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL6) == TCP_FLAG_ACK;
-+}
-+
-+static inline bool tflg_fin(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL3) == TCP_FLAG_FIN;
-+}
-+
-+static inline bool tflg_rst(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL3) == TCP_FLAG_RST;
-+}
-+
-+static inline bool tflg_rstack(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL4) ==
-+ (TCP_FLAG_ACK | TCP_FLAG_RST);
-+}
-+
-+static inline bool tflg_syn(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL4) == TCP_FLAG_SYN;
-+}
-+
-+static inline bool tflg_synack(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL4) ==
-+ (TCP_FLAG_SYN | TCP_FLAG_ACK);
-+}
-+
-+/* portscan functions */
-+static inline bool portscan_mt_stealth(const struct tcphdr *th)
-+{
-+ /*
-+ * "Connection refused" replies to our own probes must not be matched.
-+ */
-+ if (tflg_rstack(th))
-+ return false;
-+
-+ if (tflg_rst(th) && printk_ratelimit()) {
-+ printk(KERN_WARNING PFX "Warning: Pure RST received\n");
-+ return false;
-+ }
-+
-+ /*
-+ * -p tcp ! --syn -m conntrack --ctstate INVALID: Looking for non-start
-+ * packets that are not associated with any connection -- this will
-+ * match most scan types (NULL, XMAS, FIN) and ridiculous flag
-+ * combinations (SYN-RST, SYN-FIN, SYN-FIN-RST, FIN-RST, etc.).
-+ */
-+ return !tflg_syn(th);
-+}
-+
-+static inline unsigned int portscan_mt_full(int mark,
-+ enum ip_conntrack_info ctstate, bool loopback, const struct tcphdr *tcph,
-+ unsigned int payload_len)
-+{
-+ if (mark == mark_estab2) {
-+ /*
-+ * -m connmark --mark $ESTAB2
-+ */
-+ if (tflg_ack4(tcph) && payload_len == 0)
-+ return mark; /* keep mark */
-+ else if (tflg_rst(tcph) || tflg_fin(tcph))
-+ return mark_grscan;
-+ else
-+ return mark_valid;
-+ } else if (mark == mark_estab1) {
-+ /*
-+ * -m connmark --mark $ESTAB1
-+ */
-+ if (tflg_rst(tcph) || tflg_fin(tcph))
-+ return mark_cnscan;
-+ else if (!loopback && tflg_ack4(tcph) && payload_len == 0)
-+ return mark_estab2;
-+ else
-+ return mark_valid;
-+ } else if (mark == mark_synrcv) {
-+ /*
-+ * -m connmark --mark $SYN
-+ */
-+ if (loopback && tflg_synack(tcph))
-+ return mark; /* keep mark */
-+ else if (loopback && tflg_rstack(tcph))
-+ return mark_closed;
-+ else if (tflg_ack6(tcph))
-+ return mark_estab1;
-+ else
-+ return mark_synscan;
-+ } else if (ctstate == IP_CT_NEW && tflg_syn(tcph)) {
-+ /*
-+ * -p tcp --syn --ctstate NEW
-+ */
-+ return mark_synrcv;
-+ }
-+ return mark;
-+}
-+
-+static bool portscan_mt(const struct sk_buff *skb,
-+ const struct net_device *in, const struct net_device *out,
-+ const struct xt_match *match, const void *matchinfo, int offset,
-+ unsigned int protoff, bool *hotdrop)
-+{
-+ const struct xt_portscan_match_info *info = matchinfo;
-+ enum ip_conntrack_info ctstate;
-+ const struct tcphdr *tcph;
-+ struct nf_conn *ctdata;
-+ struct tcphdr tcph_buf;
-+
-+ tcph = skb_header_pointer(skb, protoff, sizeof(tcph_buf), &tcph_buf);
-+ if (tcph == NULL)
-+ return false;
-+
-+ /* Check for invalid packets: -m conntrack --ctstate INVALID */
-+ if ((ctdata = nf_ct_get(skb, &ctstate)) == NULL) {
-+ if (info->match_stealth)
-+ return portscan_mt_stealth(tcph);
-+ /*
-+ * If @ctdata is NULL, we cannot match the other scan
-+ * types, return.
-+ */
-+ return false;
-+ }
-+
-+ /*
-+ * If -m portscan was previously applied to this packet, the rules we
-+ * simulate must not be run through again. And for speedup, do not call
-+ * it either when the connection is already VALID.
-+ */
-+ if ((ctdata->mark & connmark_mask) == mark_valid ||
-+ (skb->mark & packet_mask) != mark_seen) {
-+ unsigned int n;
-+
-+ n = portscan_mt_full(ctdata->mark & connmark_mask, ctstate,
-+ (in->flags & IFF_LOOPBACK) == IFF_LOOPBACK, tcph,
-+ skb->len - protoff - 4 * tcph->doff);
-+
-+ ctdata->mark = (ctdata->mark & ~connmark_mask) | n;
-+ ((struct sk_buff *)skb)->mark =
-+ (skb->mark & ~packet_mask) ^ mark_seen;
-+ }
-+
-+ return (info->match_syn && ctdata->mark == mark_synscan) ||
-+ (info->match_cn && ctdata->mark == mark_cnscan) ||
-+ (info->match_gr && ctdata->mark == mark_grscan);
-+}
-+
-+static bool portscan_mt_check(const char *tablename, const void *entry,
-+ const struct xt_match *match, void *matchinfo, unsigned int hook_mask)
-+{
-+ const struct xt_portscan_match_info *info = matchinfo;
-+
-+ if ((info->match_stealth & ~1) || (info->match_syn & ~1) ||
-+ (info->match_cn & ~1) || (info->match_gr & ~1)) {
-+ printk(KERN_WARNING PFX "Invalid flags\n");
-+ return false;
-+ }
-+ return true;
-+}
-+
-+static struct xt_match portscan_mt_reg __read_mostly = {
-+ .name = "portscan",
-+ .family = AF_INET,
-+ .match = portscan_mt,
-+ .checkentry = portscan_mt_check,
-+ .matchsize = sizeof(struct xt_portscan_match_info),
-+ .proto = IPPROTO_TCP,
-+ .me = THIS_MODULE,
-+};
-+
-+static int __init portscan_mt_init(void)
-+{
-+ return xt_register_match(&portscan_mt_reg);
-+}
-+
-+static void __exit portscan_mt_exit(void)
-+{
-+ xt_unregister_match(&portscan_mt_reg);
-+ return;
-+}
-+
-+module_init(portscan_mt_init);
-+module_exit(portscan_mt_exit);
-+MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
-+MODULE_DESCRIPTION("netfilter \"portscan\" match");
-+MODULE_LICENSE("GPL");
-+MODULE_ALIAS("ipt_portscan");
---- a/drivers/char/random.c
-+++ b/drivers/char/random.c
-@@ -1564,6 +1564,8 @@ __u32 secure_tcp_sequence_number(__be32
- return seq;
- }
-
-+EXPORT_SYMBOL(secure_tcp_sequence_number);
-+
- /* Generate secure starting point for ephemeral IPV4 transport port search */
- u32 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport)
- {
+++ /dev/null
---- a/net/netfilter/Kconfig
-+++ b/net/netfilter/Kconfig
-@@ -401,6 +401,23 @@ config NETFILTER_XT_TARGET_CONNSECMARK
-
- To compile it as a module, choose M here. If unsure, say N.
-
-+config NETFILTER_XT_TARGET_TARPIT
-+ tristate '"TARPIT" target support'
-+ depends on NETFILTER_XTABLES
-+ ---help---
-+ Adds a TARPIT target to iptables, which 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 does not require dedicated
-+ hardware or IPs. Any TCP port that you would normally DROP or REJECT
-+ can instead become a tarpit.
-+
- config NETFILTER_XT_TARGET_TCPMSS
- tristate '"TCPMSS" target support'
- depends on NETFILTER_XTABLES && (IPV6 || IPV6=n)
---- a/net/netfilter/Makefile
-+++ b/net/netfilter/Makefile
-@@ -47,6 +47,7 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_NFLOG)
- obj-$(CONFIG_NETFILTER_XT_TARGET_NFQUEUE) += xt_NFQUEUE.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_NOTRACK) += xt_NOTRACK.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_SECMARK) += xt_SECMARK.o
-+obj-$(CONFIG_NETFILTER_XT_TARGET_TARPIT) += xt_TARPIT.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_TCPMSS) += xt_TCPMSS.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_TRACE) += xt_TRACE.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_CHAOS) += xt_CHAOS.o
---- /dev/null
-+++ b/net/netfilter/xt_TARPIT.c
-@@ -0,0 +1,279 @@
-+/*
-+ * Kernel module to capture and hold incoming TCP connections using
-+ * no local per-connection resources.
-+ *
-+ * Based on ipt_REJECT.c and offering functionality similar to
-+ * LaBrea <http://www.hackbusters.net/LaBrea/>.
-+ *
-+ * Copyright (c) 2002 Aaron Hopkins <tools@die.net>
-+ *
-+ * This program is free software; you can redistribute it and/or modify
-+ * it under the terms of the GNU General Public License as published by
-+ * the Free Software Foundation; either version 2 of the License, or
-+ * (at your option) any later version.
-+ *
-+ * This program is distributed in the hope that it will be useful,
-+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
-+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-+ * GNU General Public License for more details.
-+ *
-+ * You should have received a copy of the GNU General Public License
-+ * along with this program; if not, write to the Free Software
-+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-+ *
-+ * Goal:
-+ * - Allow incoming TCP connections to be established.
-+ * - Passing data should result in the connection being switched to the
-+ * persist state (0 byte window), in which the remote side stops sending
-+ * data and asks to continue every 60 seconds.
-+ * - Attempts to shut down the connection should be ignored completely, so
-+ * the remote side ends up having to time it out.
-+ *
-+ * This means:
-+ * - Reply to TCP SYN,!ACK,!RST,!FIN with SYN-ACK, window 5 bytes
-+ * - Reply to TCP SYN,ACK,!RST,!FIN with RST to prevent spoofing
-+ * - Reply to TCP !SYN,!RST,!FIN with ACK, window 0 bytes, rate-limited
-+ */
-+
-+#include <linux/version.h>
-+#include <linux/module.h>
-+#include <linux/skbuff.h>
-+#include <linux/ip.h>
-+#include <net/ip.h>
-+#include <net/tcp.h>
-+#include <net/icmp.h>
-+struct in_device;
-+#include <net/route.h>
-+#include <linux/random.h>
-+#include <linux/netfilter_ipv4/ip_tables.h>
-+
-+#if 0
-+#define DEBUGP printk
-+#else
-+#define DEBUGP(format, args...)
-+#endif
-+
-+/* Stolen from ip_finish_output2 */
-+static int ip_direct_send(struct sk_buff *skb)
-+{
-+ struct dst_entry *dst = skb->dst;
-+
-+ if (dst->hh != NULL)
-+ return neigh_hh_output(dst->hh, skb);
-+ else if (dst->neighbour != NULL)
-+ return dst->neighbour->output(skb);
-+
-+ if (net_ratelimit())
-+ printk(KERN_DEBUG "TARPIT ip_direct_send: no header cache and no neighbor!\n");
-+
-+ kfree_skb(skb);
-+ return -EINVAL;
-+}
-+
-+
-+/* Send reply */
-+static void tarpit_tcp(const struct sk_buff *oskb, struct rtable *ort,
-+ unsigned int local)
-+{
-+ struct sk_buff *nskb;
-+ struct rtable *nrt;
-+ struct tcphdr *otcph, *ntcph;
-+ struct flowi fl = {};
-+ unsigned int otcplen;
-+ u_int16_t tmp;
-+
-+ const struct iphdr *oiph = ip_hdr(oskb);
-+ struct iphdr *niph;
-+
-+ /* A truncated TCP header is not going to be useful */
-+ if (oskb->len < ip_hdrlen(oskb) + sizeof(struct tcphdr))
-+ return;
-+
-+ otcph = (void *)oiph + ip_hdrlen(oskb);
-+ otcplen = oskb->len - ip_hdrlen(oskb);
-+
-+ /* No replies for RST or FIN */
-+ if (otcph->rst || otcph->fin)
-+ return;
-+
-+ /* No reply to !SYN,!ACK. Rate-limit replies to !SYN,ACKs */
-+ if (!otcph->syn && (!otcph->ack || !xrlim_allow(&ort->u.dst, 1*HZ)))
-+ return;
-+
-+ /* Check checksum. */
-+ if (tcp_v4_check(otcplen, oiph->saddr, oiph->daddr,
-+ csum_partial((char *)otcph, otcplen, 0)) != 0)
-+ return;
-+
-+ /*
-+ * Copy skb (even if skb is about to be dropped, we cannot just
-+ * clone it because there may be other things, such as tcpdump,
-+ * interested in it)
-+ */
-+ nskb = skb_copy(oskb, GFP_ATOMIC);
-+ if (nskb == NULL)
-+ return;
-+
-+ niph = ip_hdr(nskb);
-+
-+ /* This packet will not be the same as the other: clear nf fields */
-+ nf_conntrack_put(nskb->nfct);
-+ nskb->nfct = NULL;
-+#ifdef CONFIG_NETFILTER_DEBUG
-+ nskb->nf_debug = 0;
-+#endif
-+
-+ ntcph = (void *)niph + ip_hdrlen(nskb);
-+
-+ /* Truncate to length (no data) */
-+ ntcph->doff = sizeof(struct tcphdr)/4;
-+ skb_trim(nskb, ip_hdrlen(nskb) + sizeof(struct tcphdr));
-+ niph->tot_len = htons(nskb->len);
-+
-+ /* Swap source and dest */
-+ niph->daddr = xchg(&niph->saddr, niph->daddr);
-+ tmp = ntcph->source;
-+ ntcph->source = ntcph->dest;
-+ ntcph->dest = tmp;
-+
-+ /* Use supplied sequence number or make a new one */
-+ ntcph->seq = otcph->ack ? otcph->ack_seq
-+ : htonl(secure_tcp_sequence_number(niph->saddr,
-+ niph->daddr,
-+ ntcph->source,
-+ ntcph->dest));
-+
-+ /* Our SYN-ACKs must have a >0 window */
-+ ntcph->window = (otcph->syn && !otcph->ack) ? htons(5) : 0;
-+
-+ ntcph->urg_ptr = 0;
-+
-+ /* Reset flags */
-+ ((u_int8_t *)ntcph)[13] = 0;
-+
-+ if (otcph->syn && otcph->ack) {
-+ ntcph->rst = 1;
-+ ntcph->ack_seq = 0;
-+ } else {
-+ ntcph->syn = otcph->syn;
-+ ntcph->ack = 1;
-+ ntcph->ack_seq = htonl(ntohl(otcph->seq) + otcph->syn);
-+ }
-+
-+ /* Adjust TCP checksum */
-+ ntcph->check = 0;
-+ ntcph->check = tcp_v4_check(sizeof(struct tcphdr),
-+ niph->saddr,
-+ niph->daddr,
-+ csum_partial((char *)ntcph,
-+ sizeof(struct tcphdr), 0));
-+
-+ fl.nl_u.ip4_u.daddr = niph->daddr;
-+ fl.nl_u.ip4_u.saddr = local ? niph->saddr : 0;
-+ fl.nl_u.ip4_u.tos = RT_TOS(niph->tos) | RTO_CONN;
-+ fl.oif = 0;
-+
-+ if (ip_route_output_key(&nrt, &fl))
-+ goto free_nskb;
-+
-+ dst_release(nskb->dst);
-+ nskb->dst = &nrt->u.dst;
-+
-+ /* Adjust IP TTL */
-+ niph->ttl = dst_metric(nskb->dst, RTAX_HOPLIMIT);
-+
-+ /* Set DF, id = 0 */
-+ niph->frag_off = htons(IP_DF);
-+ niph->id = 0;
-+
-+ /* Adjust IP checksum */
-+ niph->check = 0;
-+ niph->check = ip_fast_csum((unsigned char *)niph, niph->ihl);
-+
-+ /* "Never happens" */
-+ if (nskb->len > dst_mtu(nskb->dst))
-+ goto free_nskb;
-+
-+ ip_direct_send(nskb);
-+ return;
-+
-+ free_nskb:
-+ kfree_skb(nskb);
-+}
-+
-+static unsigned int xt_tarpit_target(struct sk_buff *skb,
-+ const struct net_device *in,
-+ const struct net_device *out,
-+ unsigned int hooknum,
-+ const struct xt_target *target,
-+ const void *targinfo)
-+{
-+ const struct iphdr *iph = ip_hdr(skb);
-+ struct rtable *rt = (void *)skb->dst;
-+
-+ /* Do we have an input route cache entry? */
-+ if (rt == NULL)
-+ return NF_DROP;
-+
-+ /* No replies to physical multicast/broadcast */
-+ if (skb->pkt_type != PACKET_HOST && skb->pkt_type != PACKET_OTHERHOST)
-+ return NF_DROP;
-+
-+ /* Now check at the protocol level */
-+ if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
-+ return NF_DROP;
-+
-+ /*
-+ * Our naive response construction does not deal with IP
-+ * options, and probably should not try.
-+ */
-+ if (iph->ihl * 4 != sizeof(struct iphdr))
-+ return NF_DROP;
-+
-+ /* We are not interested in fragments */
-+ if (iph->frag_off & htons(IP_OFFSET))
-+ return NF_DROP;
-+
-+ tarpit_tcp(skb, rt, hooknum == NF_IP_LOCAL_IN);
-+ return NF_DROP;
-+}
-+
-+static bool xt_tarpit_check(const char *tablename, const void *entry,
-+ const struct xt_target *target, void *targinfo,
-+ unsigned int hook_mask)
-+{
-+ bool invalid;
-+
-+ if (strcmp(tablename, "raw") == 0 && hook_mask == NF_IP_PRE_ROUTING)
-+ return true;
-+ if (strcmp(tablename, "filter") != 0)
-+ return false;
-+ invalid = hook_mask & ~((1 << NF_IP_LOCAL_IN) | (1 << NF_IP_FORWARD));
-+ return !invalid;
-+}
-+
-+static struct xt_target xt_tarpit_reg = {
-+ .name = "TARPIT",
-+ .family = AF_INET,
-+ .proto = IPPROTO_TCP,
-+ .target = xt_tarpit_target,
-+ .checkentry = xt_tarpit_check,
-+ .me = THIS_MODULE,
-+};
-+
-+static int __init xt_tarpit_init(void)
-+{
-+ return xt_register_target(&xt_tarpit_reg);
-+}
-+
-+static void __exit xt_tarpit_exit(void)
-+{
-+ xt_unregister_target(&xt_tarpit_reg);
-+}
-+
-+module_init(xt_tarpit_init);
-+module_exit(xt_tarpit_exit);
-+MODULE_DESCRIPTION("netfilter xt_TARPIT target module");
-+MODULE_AUTHOR("Jan Engelhardt <jengelh@gmx.de>");
-+MODULE_LICENSE("GPL");
-+MODULE_ALIAS("ipt_TARPIT");
help
H.323 is a VoIP signalling protocol from ITU-T. As one of the most
important VoIP protocols, it is widely used by voice hardware and
-@@ -420,7 +420,7 @@ config NETFILTER_XT_TARGET_TARPIT
+@@ -387,7 +387,7 @@ config NETFILTER_XT_TARGET_CONNSECMARK
config NETFILTER_XT_TARGET_TCPMSS
tristate '"TCPMSS" target support'
+++ /dev/null
---- a/include/linux/netfilter/Kbuild
-+++ b/include/linux/netfilter/Kbuild
-@@ -3,6 +3,7 @@ header-y += nf_conntrack_tuple_common.h
- header-y += nfnetlink_conntrack.h
- header-y += nfnetlink_log.h
- header-y += nfnetlink_queue.h
-+header-y += xt_CHAOS.h
- header-y += xt_CLASSIFY.h
- header-y += xt_CONNMARK.h
- header-y += xt_CONNSECMARK.h
---- /dev/null
-+++ b/include/linux/netfilter/oot_conntrack.h
-@@ -0,0 +1,5 @@
-+#if defined(CONFIG_IP_NF_CONNTRACK) || defined(CONFIG_IP_NF_CONNTRACK_MODULE)
-+# include <linux/netfilter_ipv4/ip_conntrack.h>
-+#else /* linux-2.6.20+ */
-+# include <net/netfilter/nf_nat_rule.h>
-+#endif
---- /dev/null
-+++ b/include/linux/netfilter/oot_trans.h
-@@ -0,0 +1,14 @@
-+/* Out of tree workarounds */
-+#include <linux/version.h>
-+#if LINUX_VERSION_CODE <= KERNEL_VERSION(2, 6, 18)
-+# define HAVE_MATCHINFOSIZE 1
-+# define HAVE_TARGUSERINFO 1
-+# define HAVE_TARGINFOSIZE 1
-+#endif
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 20)
-+# define nfmark mark
-+#endif
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 21)
-+# define tcp_v4_check(tcph, tcph_sz, s, d, csp) \
-+ tcp_v4_check((tcph_sz), (s), (d), (csp))
-+#endif
---- /dev/null
-+++ b/include/linux/netfilter/xt_CHAOS.h
-@@ -0,0 +1,14 @@
-+#ifndef _LINUX_NETFILTER_XT_CHAOS_H
-+#define _LINUX_NETFILTER_XT_CHAOS_H 1
-+
-+enum xt_chaos_target_variant {
-+ XTCHAOS_NORMAL,
-+ XTCHAOS_TARPIT,
-+ XTCHAOS_DELUDE,
-+};
-+
-+struct xt_chaos_target_info {
-+ uint8_t variant;
-+};
-+
-+#endif /* _LINUX_NETFILTER_XT_CHAOS_H */
---- /dev/null
-+++ b/include/linux/netfilter/xt_portscan.h
-@@ -0,0 +1,8 @@
-+#ifndef _LINUX_NETFILTER_XT_PORTSCAN_H
-+#define _LINUX_NETFILTER_XT_PORTSCAN_H 1
-+
-+struct xt_portscan_match_info {
-+ uint8_t match_stealth, match_syn, match_cn, match_gr;
-+};
-+
-+#endif /* _LINUX_NETFILTER_XT_PORTSCAN_H */
---- /dev/null
-+++ b/net/netfilter/find_match.c
-@@ -0,0 +1,39 @@
-+/*
-+ xt_request_find_match
-+ by Jan Engelhardt <jengelh [at] gmx de>, 2006 - 2007
-+
-+ Based upon linux-2.6.18.5/net/netfilter/x_tables.c:
-+ Copyright (C) 2006-2006 Harald Welte <laforge@netfilter.org>
-+ This program is free software; you can redistribute it and/or modify
-+ it under the terms of the GNU General Public License version 2 as
-+ published by the Free Software Foundation.
-+*/
-+#include <linux/err.h>
-+#include <linux/netfilter_arp.h>
-+#include <linux/socket.h>
-+#include <linux/netfilter/x_tables.h>
-+
-+/*
-+ * Yeah this code is sub-optimal, but the function is missing in
-+ * mainline so far. -jengelh
-+ */
-+static struct xt_match *xt_request_find_match_lo(int af, const char *name,
-+ u8 revision)
-+{
-+ static const char *const xt_prefix[] = {
-+ [AF_INET] = "ip",
-+ [AF_INET6] = "ip6",
-+ [NF_ARP] = "arp",
-+ };
-+ struct xt_match *match;
-+
-+ match = try_then_request_module(xt_find_match(af, name, revision),
-+ "%st_%s", xt_prefix[af], name);
-+ if (IS_ERR(match) || match == NULL)
-+ return NULL;
-+
-+ return match;
-+}
-+
-+/* In case it goes into mainline, let this out-of-tree package compile */
-+#define xt_request_find_match xt_request_find_match_lo
---- a/net/netfilter/Kconfig
-+++ b/net/netfilter/Kconfig
-@@ -276,6 +276,14 @@ config NETFILTER_XTABLES
-
- # alphabetically ordered list of targets
-
-+config NETFILTER_XT_TARGET_CHAOS
-+ tristate '"CHAOS" target support'
-+ depends on NETFILTER_XTABLES
-+ help
-+ This option adds a `CHAOS' target.
-+
-+ To compile it as a module, choose M here. If unsure, say N.
-+
- config NETFILTER_XT_TARGET_CLASSIFY
- tristate '"CLASSIFY" target support'
- depends on NETFILTER_XTABLES
-@@ -305,6 +313,14 @@ config NETFILTER_XT_TARGET_CONNMARK
- <file:Documentation/kbuild/modules.txt>. The module will be called
- ipt_CONNMARK.ko. If unsure, say `N'.
-
-+config NETFILTER_XT_TARGET_DELUDE
-+ tristate '"DELUDE" target support'
-+ depends on NETFILTER_XTABLES
-+ help
-+ This option adds a `DELUDE' target.
-+
-+ To compile it as a module, choose M here. If unsure, say N.
-+
- config NETFILTER_XT_TARGET_DSCP
- tristate '"DSCP" and "TOS" target support'
- depends on NETFILTER_XTABLES
-@@ -640,6 +656,14 @@ config NETFILTER_XT_MATCH_POLICY
-
- To compile it as a module, choose M here. If unsure, say N.
-
-+config NETFILTER_XT_MATCH_PORTSCAN
-+ tristate '"portscan" match support'
-+ depends on NETFILTER_XTABLES
-+ help
-+ This option adds a 'portscan' match support.
-+
-+ To compile it as a module, choose M here. If unsure, say N.
-+
- config NETFILTER_XT_MATCH_MULTIPORT
- tristate '"multiport" Multiple port match support'
- depends on NETFILTER_XTABLES
---- a/net/netfilter/Makefile
-+++ b/net/netfilter/Makefile
-@@ -50,6 +50,8 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_SECMARK
- obj-$(CONFIG_NETFILTER_XT_TARGET_TCPMSS) += xt_TCPMSS.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_TCPOPTSTRIP) += xt_TCPOPTSTRIP.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_TRACE) += xt_TRACE.o
-+obj-$(CONFIG_NETFILTER_XT_TARGET_CHAOS) += xt_CHAOS.o
-+obj-$(CONFIG_NETFILTER_XT_TARGET_DELUDE) += xt_DELUDE.o
-
- # matches
- obj-$(CONFIG_NETFILTER_XT_MATCH_COMMENT) += xt_comment.o
-@@ -83,3 +85,4 @@ obj-$(CONFIG_NETFILTER_XT_MATCH_STRING)
- obj-$(CONFIG_NETFILTER_XT_MATCH_TCPMSS) += xt_tcpmss.o
- obj-$(CONFIG_NETFILTER_XT_MATCH_TIME) += xt_time.o
- obj-$(CONFIG_NETFILTER_XT_MATCH_U32) += xt_u32.o
-+obj-$(CONFIG_NETFILTER_XT_MATCH_PORTSCAN) += xt_portscan.o
---- /dev/null
-+++ b/net/netfilter/xt_CHAOS.c
-@@ -0,0 +1,200 @@
-+/*
-+ * CHAOS target for netfilter
-+ * 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 <linux/icmp.h>
-+#include <linux/in.h>
-+#include <linux/ip.h>
-+#include <linux/module.h>
-+#include <linux/skbuff.h>
-+#include <linux/stat.h>
-+#include <linux/netfilter/x_tables.h>
-+#include <linux/netfilter/xt_tcpudp.h>
-+#include <linux/netfilter_ipv4/ipt_REJECT.h>
-+#include <net/ip.h>
-+#if defined(_LOCAL)
-+# include "xt_CHAOS.h"
-+# include "find_match.c"
-+#elif defined(CONFIG_NETFILTER_XT_TARGET_CHAOS) || \
-+ defined(CONFIG_NETFILTER_XT_TARGET_CHAOS_MODULE)
-+# include <linux/netfilter/xt_CHAOS.h>
-+# include "find_match.c"
-+#else
-+# include "xt_CHAOS.h"
-+# include "find_match.c"
-+#endif
-+#define PFX KBUILD_MODNAME ": "
-+
-+/* Module parameters */
-+static unsigned int reject_percentage = ~0U * .01;
-+static unsigned int delude_percentage = ~0U * .0101;
-+module_param(reject_percentage, uint, S_IRUGO | S_IWUSR);
-+module_param(delude_percentage, uint, S_IRUGO | S_IWUSR);
-+
-+/* References to other matches/targets */
-+static struct xt_match *xm_tcp;
-+static struct xt_target *xt_delude, *xt_reject, *xt_tarpit;
-+
-+static int have_delude, have_tarpit;
-+
-+/* Static data for other matches/targets */
-+static const struct ipt_reject_info reject_params = {
-+ .with = ICMP_HOST_UNREACH,
-+};
-+
-+static const struct xt_tcp tcp_params = {
-+ .spts = {0, ~0},
-+ .dpts = {0, ~0},
-+};
-+
-+/* CHAOS functions */
-+static void xt_chaos_total(const struct xt_chaos_target_info *info,
-+ struct sk_buff *skb, const struct net_device *in,
-+ const struct net_device *out, unsigned int hooknum)
-+{
-+ const struct iphdr *iph = ip_hdr(skb);
-+ const int protoff = 4 * iph->ihl;
-+ const int offset = ntohs(iph->frag_off) & IP_OFFSET;
-+ const struct xt_target *destiny;
-+ bool hotdrop = false, ret;
-+
-+ ret = xm_tcp->match(skb, in, out, xm_tcp, &tcp_params,
-+ offset, protoff, &hotdrop);
-+ if (!ret || hotdrop || (unsigned int)net_random() > delude_percentage)
-+ return;
-+
-+ destiny = (info->variant == XTCHAOS_TARPIT) ? xt_tarpit : xt_delude;
-+ destiny->target(skb, in, out, hooknum, destiny, NULL);
-+ return;
-+}
-+
-+static unsigned int chaos_tg(struct sk_buff *skb,
-+ const struct net_device *in, const struct net_device *out,
-+ unsigned int hooknum, const struct xt_target *target, const void *targinfo)
-+{
-+ /*
-+ * Equivalent to:
-+ * -A chaos -m statistic --mode random --probability \
-+ * $reject_percentage -j REJECT --reject-with host-unreach;
-+ * -A chaos -p tcp -m statistic --mode random --probability \
-+ * $delude_percentage -j DELUDE;
-+ * -A chaos -j DROP;
-+ */
-+ const struct xt_chaos_target_info *info = targinfo;
-+ const struct iphdr *iph = ip_hdr(skb);
-+
-+ if ((unsigned int)net_random() <= reject_percentage)
-+ return xt_reject->target(skb, in, out, hooknum, target,
-+ &reject_params);
-+
-+ /* TARPIT/DELUDE may not be called from the OUTPUT chain */
-+ if (iph->protocol == IPPROTO_TCP &&
-+ info->variant != XTCHAOS_NORMAL && hooknum != NF_INET_LOCAL_OUT)
-+ xt_chaos_total(info, skb, in, out, hooknum);
-+
-+ return NF_DROP;
-+}
-+
-+static bool chaos_tg_check(const char *tablename, const void *entry,
-+ const struct xt_target *target, void *targinfo, unsigned int hook_mask)
-+{
-+ const struct xt_chaos_target_info *info = targinfo;
-+
-+ if (info->variant == XTCHAOS_DELUDE && !have_delude) {
-+ printk(KERN_WARNING PFX "Error: Cannot use --delude when "
-+ "DELUDE module not available\n");
-+ return false;
-+ }
-+ if (info->variant == XTCHAOS_TARPIT && !have_tarpit) {
-+ printk(KERN_WARNING PFX "Error: Cannot use --tarpit when "
-+ "TARPIT module not available\n");
-+ return false;
-+ }
-+
-+ return true;
-+}
-+
-+static struct xt_target chaos_tg_reg = {
-+ .name = "CHAOS",
-+ .family = AF_INET,
-+ .table = "filter",
-+ .hooks = (1 << NF_INET_LOCAL_IN) | (1 << NF_INET_FORWARD) |
-+ (1 << NF_INET_LOCAL_OUT),
-+ .checkentry = chaos_tg_check,
-+ .target = chaos_tg,
-+ .targetsize = sizeof(struct xt_chaos_target_info),
-+ .me = THIS_MODULE,
-+};
-+
-+static int __init chaos_tg_init(void)
-+{
-+ int ret = -EINVAL;
-+
-+ xm_tcp = xt_request_find_match(AF_INET, "tcp", 0);
-+ if (xm_tcp == NULL) {
-+ printk(KERN_WARNING PFX "Error: Could not find or load "
-+ "\"tcp\" match\n");
-+ return -EINVAL;
-+ }
-+
-+ xt_reject = xt_request_find_target(AF_INET, "REJECT", 0);
-+ if (xt_reject == NULL) {
-+ printk(KERN_WARNING PFX "Error: Could not find or load "
-+ "\"REJECT\" target\n");
-+ goto out2;
-+ }
-+
-+ xt_tarpit = xt_request_find_target(AF_INET, "TARPIT", 0);
-+ have_tarpit = xt_tarpit != NULL;
-+ if (!have_tarpit)
-+ printk(KERN_WARNING PFX "Warning: Could not find or load "
-+ "\"TARPIT\" target\n");
-+
-+ xt_delude = xt_request_find_target(AF_INET, "DELUDE", 0);
-+ have_delude = xt_delude != NULL;
-+ if (!have_delude)
-+ printk(KERN_WARNING PFX "Warning: Could not find or load "
-+ "\"DELUDE\" target\n");
-+
-+ if ((ret = xt_register_target(&chaos_tg_reg)) != 0) {
-+ printk(KERN_WARNING PFX "xt_register_target returned "
-+ "error %d\n", ret);
-+ goto out3;
-+ }
-+
-+ return 0;
-+
-+ out3:
-+ if (have_delude)
-+ module_put(xt_delude->me);
-+ if (have_tarpit)
-+ module_put(xt_tarpit->me);
-+ module_put(xt_reject->me);
-+ out2:
-+ module_put(xm_tcp->me);
-+ return ret;
-+}
-+
-+static void __exit chaos_tg_exit(void)
-+{
-+ xt_unregister_target(&chaos_tg_reg);
-+ module_put(xm_tcp->me);
-+ module_put(xt_reject->me);
-+ if (have_delude)
-+ module_put(xt_delude->me);
-+ if (have_tarpit)
-+ module_put(xt_tarpit->me);
-+ return;
-+}
-+
-+module_init(chaos_tg_init);
-+module_exit(chaos_tg_exit);
-+MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
-+MODULE_DESCRIPTION("netfilter \"CHAOS\" target");
-+MODULE_LICENSE("GPL");
-+MODULE_ALIAS("ipt_CHAOS");
---- /dev/null
-+++ b/net/netfilter/xt_DELUDE.c
-@@ -0,0 +1,197 @@
-+/*
-+ * DELUDE target
-+ * Copyright © CC Computer Consultants GmbH, 2007
-+ * Contact: Jan Engelhardt <jengelh@computergmbh.de>
-+ *
-+ * Based upon linux-2.6.18.5/net/ipv4/netfilter/ipt_REJECT.c:
-+ * (C) 1999-2001 Paul `Rusty' Russell
-+ * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
-+ *
-+ * xt_DELUDE acts like REJECT, but does reply with SYN-ACK on SYN.
-+ *
-+ * This program is free software; you can redistribute it and/or modify
-+ * it under the terms of the GNU General Public License version 2 as
-+ * published by the Free Software Foundation.
-+ */
-+#include <linux/module.h>
-+#include <linux/skbuff.h>
-+#include <linux/ip.h>
-+#include <linux/tcp.h>
-+#include <linux/netfilter/x_tables.h>
-+#ifdef CONFIG_BRIDGE_NETFILTER
-+# include <linux/netfilter_bridge.h>
-+#endif
-+#include <net/tcp.h>
-+#define PFX KBUILD_MODNAME ": "
-+
-+static void delude_send_reset(struct sk_buff *oldskb, unsigned int hook)
-+{
-+ struct tcphdr _otcph, *oth, *tcph;
-+ unsigned int addr_type;
-+ struct sk_buff *nskb;
-+ u_int16_t tmp_port;
-+ u_int32_t tmp_addr;
-+ struct iphdr *niph;
-+ bool needs_ack;
-+
-+ /* IP header checks: fragment. */
-+ if (ip_hdr(oldskb)->frag_off & htons(IP_OFFSET))
-+ return;
-+
-+ oth = skb_header_pointer(oldskb, ip_hdrlen(oldskb),
-+ sizeof(_otcph), &_otcph);
-+ if (oth == NULL)
-+ return;
-+
-+ /* No RST for RST. */
-+ if (oth->rst)
-+ return;
-+
-+ /* Check checksum */
-+ if (nf_ip_checksum(oldskb, hook, ip_hdrlen(oldskb), IPPROTO_TCP))
-+ return;
-+
-+ /* We need a linear, writeable skb. We also need to expand
-+ headroom in case hh_len of incoming interface < hh_len of
-+ outgoing interface */
-+ nskb = skb_copy_expand(oldskb, LL_MAX_HEADER, skb_tailroom(oldskb),
-+ GFP_ATOMIC);
-+ if (!nskb)
-+ return;
-+
-+ /* This packet will not be the same as the other: clear nf fields */
-+ nf_reset(nskb);
-+ nskb->mark = 0;
-+ skb_init_secmark(nskb);
-+
-+ skb_shinfo(nskb)->gso_size = 0;
-+ skb_shinfo(nskb)->gso_segs = 0;
-+ skb_shinfo(nskb)->gso_type = 0;
-+
-+ tcph = (struct tcphdr *)(skb_network_header(nskb) + ip_hdrlen(nskb));
-+
-+ /* Swap source and dest */
-+ niph = ip_hdr(nskb);
-+ tmp_addr = niph->saddr;
-+ niph->saddr = niph->daddr;
-+ niph->daddr = tmp_addr;
-+ tmp_port = tcph->source;
-+ tcph->source = tcph->dest;
-+ tcph->dest = tmp_port;
-+
-+ /* Truncate to length (no data) */
-+ tcph->doff = sizeof(struct tcphdr) / 4;
-+ skb_trim(nskb, ip_hdrlen(nskb) + sizeof(struct tcphdr));
-+ niph->tot_len = htons(nskb->len);
-+
-+ if (oth->syn && !oth->ack && !oth->rst && !oth->fin) {
-+ /* DELUDE essential part */
-+ tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn + oth->fin +
-+ oldskb->len - ip_hdrlen(oldskb) -
-+ (oth->doff << 2));
-+ tcph->seq = false;
-+ tcph->ack = true;
-+ } else {
-+ if (!tcph->ack) {
-+ needs_ack = true;
-+ tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn +
-+ oth->fin + oldskb->len -
-+ ip_hdrlen(oldskb) - (oth->doff<<2));
-+ tcph->seq = false;
-+ } else {
-+ needs_ack = false;
-+ tcph->seq = oth->ack_seq;
-+ tcph->ack_seq = false;
-+ }
-+
-+ /* Reset flags */
-+ ((u_int8_t *)tcph)[13] = 0;
-+ tcph->rst = true;
-+ tcph->ack = needs_ack;
-+ }
-+
-+ tcph->window = 0;
-+ tcph->urg_ptr = 0;
-+
-+ /* Adjust TCP checksum */
-+ tcph->check = 0;
-+ tcph->check = tcp_v4_check(sizeof(struct tcphdr), niph->saddr,
-+ niph->daddr, csum_partial((char *)tcph,
-+ sizeof(struct tcphdr), 0));
-+
-+ /* Set DF, id = 0 */
-+ niph->frag_off = htons(IP_DF);
-+ niph->id = 0;
-+
-+ addr_type = RTN_UNSPEC;
-+#ifdef CONFIG_BRIDGE_NETFILTER
-+ if (hook != NF_INET_FORWARD || (nskb->nf_bridge != NULL &&
-+ nskb->nf_bridge->mask & BRNF_BRIDGED))
-+#else
-+ if (hook != NF_INET_FORWARD)
-+#endif
-+ addr_type = RTN_LOCAL;
-+
-+ if (ip_route_me_harder(nskb, addr_type))
-+ goto free_nskb;
-+
-+ nskb->ip_summed = CHECKSUM_NONE;
-+
-+ /* Adjust IP TTL */
-+ niph->ttl = dst_metric(nskb->dst, RTAX_HOPLIMIT);
-+
-+ /* Adjust IP checksum */
-+ niph->check = 0;
-+ niph->check = ip_fast_csum(skb_network_header(nskb), niph->ihl);
-+
-+ /* "Never happens" */
-+ if (nskb->len > dst_mtu(nskb->dst))
-+ goto free_nskb;
-+
-+ nf_ct_attach(nskb, oldskb);
-+
-+ NF_HOOK(PF_INET, NF_INET_LOCAL_OUT, nskb, NULL, nskb->dst->dev,
-+ dst_output);
-+ return;
-+
-+ free_nskb:
-+ kfree_skb(nskb);
-+}
-+
-+static unsigned int delude_tg(struct sk_buff *skb,
-+ const struct net_device *in, const struct net_device *out,
-+ unsigned int hooknum, const struct xt_target *target, const void *targinfo)
-+{
-+ /* WARNING: This code causes reentry within iptables.
-+ This means that the iptables jump stack is now crap. We
-+ must return an absolute verdict. --RR */
-+ delude_send_reset(skb, hooknum);
-+ return NF_DROP;
-+}
-+
-+static struct xt_target delude_tg_reg = {
-+ .name = "DELUDE",
-+ .family = AF_INET,
-+ .table = "filter",
-+ .hooks = (1 << NF_INET_LOCAL_IN) | (1 << NF_INET_FORWARD),
-+ .target = delude_tg,
-+ .proto = IPPROTO_TCP,
-+ .me = THIS_MODULE,
-+};
-+
-+static int __init delude_tg_init(void)
-+{
-+ return xt_register_target(&delude_tg_reg);
-+}
-+
-+static void __exit delude_tg_exit(void)
-+{
-+ xt_unregister_target(&delude_tg_reg);
-+}
-+
-+module_init(delude_tg_init);
-+module_exit(delude_tg_exit);
-+MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
-+MODULE_DESCRIPTION("netfilter \"DELUDE\" target");
-+MODULE_LICENSE("GPL");
-+MODULE_ALIAS("ipt_DELUDE");
---- /dev/null
-+++ b/net/netfilter/xt_portscan.c
-@@ -0,0 +1,269 @@
-+/*
-+ * portscan match for netfilter
-+ * 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 <linux/in.h>
-+#include <linux/ip.h>
-+#include <linux/module.h>
-+#include <linux/moduleparam.h>
-+#include <linux/skbuff.h>
-+#include <linux/stat.h>
-+#include <linux/tcp.h>
-+#include <linux/types.h>
-+#include <linux/version.h>
-+#include <linux/netfilter/x_tables.h>
-+#include <linux/netfilter/xt_tcpudp.h>
-+#include <net/netfilter/nf_nat_rule.h>
-+#if defined(_LOCAL)
-+# include "xt_portscan.h"
-+#elif defined(CONFIG_NETFILTER_XT_MATCH_PORTSCAN) || \
-+ defined(CONFIG_NETFILTER_XT_MATCH_PORTSCAN_MODULE)
-+# include <linux/netfilter/xt_portscan.h>
-+#else
-+# include "xt_portscan.h"
-+#endif
-+#define PFX KBUILD_MODNAME ": "
-+
-+enum {
-+ TCP_FLAGS_ALL3 = TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_SYN,
-+ TCP_FLAGS_ALL4 = TCP_FLAGS_ALL3 | TCP_FLAG_ACK,
-+ TCP_FLAGS_ALL6 = TCP_FLAGS_ALL4 | TCP_FLAG_PSH | TCP_FLAG_URG,
-+};
-+
-+/* Module parameters */
-+static unsigned int
-+ connmark_mask = ~0,
-+ packet_mask = ~0,
-+ mark_seen = 0x9,
-+ mark_synrcv = 0x1,
-+ mark_closed = 0x2,
-+ mark_synscan = 0x3,
-+ mark_estab1 = 0x4,
-+ mark_estab2 = 0x5,
-+ mark_cnscan = 0x6,
-+ mark_grscan = 0x7,
-+ mark_valid = 0x8;
-+
-+module_param(connmark_mask, uint, S_IRUGO | S_IWUSR);
-+module_param(packet_mask, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_seen, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_synrcv, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_closed, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_synscan, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_estab1, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_estab2, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_cnscan, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_grscan, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_valid, uint, S_IRUGO | S_IWUSR);
-+MODULE_PARM_DESC(connmark_mask, "only set specified bits in connection mark");
-+MODULE_PARM_DESC(packet_mask, "only set specified bits in packet mark");
-+MODULE_PARM_DESC(mark_seen, "nfmark value for packet-seen state");
-+MODULE_PARM_DESC(mark_synrcv, "connmark value for SYN Received state");
-+MODULE_PARM_DESC(mark_closed, "connmark value for closed state");
-+MODULE_PARM_DESC(mark_synscan, "connmark value for SYN Scan state");
-+MODULE_PARM_DESC(mark_estab1, "connmark value for Established-1 state");
-+MODULE_PARM_DESC(mark_estab2, "connmark value for Established-2 state");
-+MODULE_PARM_DESC(mark_cnscan, "connmark value for Connect Scan state");
-+MODULE_PARM_DESC(mark_grscan, "connmark value for Grab Scan state");
-+MODULE_PARM_DESC(mark_valid, "connmark value for Valid state");
-+
-+/* TCP flag functions */
-+static inline bool tflg_ack4(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL4) == TCP_FLAG_ACK;
-+}
-+
-+static inline bool tflg_ack6(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL6) == TCP_FLAG_ACK;
-+}
-+
-+static inline bool tflg_fin(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL3) == TCP_FLAG_FIN;
-+}
-+
-+static inline bool tflg_rst(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL3) == TCP_FLAG_RST;
-+}
-+
-+static inline bool tflg_rstack(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL4) ==
-+ (TCP_FLAG_ACK | TCP_FLAG_RST);
-+}
-+
-+static inline bool tflg_syn(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL4) == TCP_FLAG_SYN;
-+}
-+
-+static inline bool tflg_synack(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL4) ==
-+ (TCP_FLAG_SYN | TCP_FLAG_ACK);
-+}
-+
-+/* portscan functions */
-+static inline bool portscan_mt_stealth(const struct tcphdr *th)
-+{
-+ /*
-+ * "Connection refused" replies to our own probes must not be matched.
-+ */
-+ if (tflg_rstack(th))
-+ return false;
-+
-+ if (tflg_rst(th) && printk_ratelimit()) {
-+ printk(KERN_WARNING PFX "Warning: Pure RST received\n");
-+ return false;
-+ }
-+
-+ /*
-+ * -p tcp ! --syn -m conntrack --ctstate INVALID: Looking for non-start
-+ * packets that are not associated with any connection -- this will
-+ * match most scan types (NULL, XMAS, FIN) and ridiculous flag
-+ * combinations (SYN-RST, SYN-FIN, SYN-FIN-RST, FIN-RST, etc.).
-+ */
-+ return !tflg_syn(th);
-+}
-+
-+static inline unsigned int portscan_mt_full(int mark,
-+ enum ip_conntrack_info ctstate, bool loopback, const struct tcphdr *tcph,
-+ unsigned int payload_len)
-+{
-+ if (mark == mark_estab2) {
-+ /*
-+ * -m connmark --mark $ESTAB2
-+ */
-+ if (tflg_ack4(tcph) && payload_len == 0)
-+ return mark; /* keep mark */
-+ else if (tflg_rst(tcph) || tflg_fin(tcph))
-+ return mark_grscan;
-+ else
-+ return mark_valid;
-+ } else if (mark == mark_estab1) {
-+ /*
-+ * -m connmark --mark $ESTAB1
-+ */
-+ if (tflg_rst(tcph) || tflg_fin(tcph))
-+ return mark_cnscan;
-+ else if (!loopback && tflg_ack4(tcph) && payload_len == 0)
-+ return mark_estab2;
-+ else
-+ return mark_valid;
-+ } else if (mark == mark_synrcv) {
-+ /*
-+ * -m connmark --mark $SYN
-+ */
-+ if (loopback && tflg_synack(tcph))
-+ return mark; /* keep mark */
-+ else if (loopback && tflg_rstack(tcph))
-+ return mark_closed;
-+ else if (tflg_ack6(tcph))
-+ return mark_estab1;
-+ else
-+ return mark_synscan;
-+ } else if (ctstate == IP_CT_NEW && tflg_syn(tcph)) {
-+ /*
-+ * -p tcp --syn --ctstate NEW
-+ */
-+ return mark_synrcv;
-+ }
-+ return mark;
-+}
-+
-+static bool portscan_mt(const struct sk_buff *skb,
-+ const struct net_device *in, const struct net_device *out,
-+ const struct xt_match *match, const void *matchinfo, int offset,
-+ unsigned int protoff, bool *hotdrop)
-+{
-+ const struct xt_portscan_match_info *info = matchinfo;
-+ enum ip_conntrack_info ctstate;
-+ const struct tcphdr *tcph;
-+ struct nf_conn *ctdata;
-+ struct tcphdr tcph_buf;
-+
-+ tcph = skb_header_pointer(skb, protoff, sizeof(tcph_buf), &tcph_buf);
-+ if (tcph == NULL)
-+ return false;
-+
-+ /* Check for invalid packets: -m conntrack --ctstate INVALID */
-+ if ((ctdata = nf_ct_get(skb, &ctstate)) == NULL) {
-+ if (info->match_stealth)
-+ return portscan_mt_stealth(tcph);
-+ /*
-+ * If @ctdata is NULL, we cannot match the other scan
-+ * types, return.
-+ */
-+ return false;
-+ }
-+
-+ /*
-+ * If -m portscan was previously applied to this packet, the rules we
-+ * simulate must not be run through again. And for speedup, do not call
-+ * it either when the connection is already VALID.
-+ */
-+ if ((ctdata->mark & connmark_mask) == mark_valid ||
-+ (skb->mark & packet_mask) != mark_seen) {
-+ unsigned int n;
-+
-+ n = portscan_mt_full(ctdata->mark & connmark_mask, ctstate,
-+ (in->flags & IFF_LOOPBACK) == IFF_LOOPBACK, tcph,
-+ skb->len - protoff - 4 * tcph->doff);
-+
-+ ctdata->mark = (ctdata->mark & ~connmark_mask) | n;
-+ ((struct sk_buff *)skb)->mark =
-+ (skb->mark & ~packet_mask) ^ mark_seen;
-+ }
-+
-+ return (info->match_syn && ctdata->mark == mark_synscan) ||
-+ (info->match_cn && ctdata->mark == mark_cnscan) ||
-+ (info->match_gr && ctdata->mark == mark_grscan);
-+}
-+
-+static bool portscan_mt_check(const char *tablename, const void *entry,
-+ const struct xt_match *match, void *matchinfo, unsigned int hook_mask)
-+{
-+ const struct xt_portscan_match_info *info = matchinfo;
-+
-+ if ((info->match_stealth & ~1) || (info->match_syn & ~1) ||
-+ (info->match_cn & ~1) || (info->match_gr & ~1)) {
-+ printk(KERN_WARNING PFX "Invalid flags\n");
-+ return false;
-+ }
-+ return true;
-+}
-+
-+static struct xt_match portscan_mt_reg __read_mostly = {
-+ .name = "portscan",
-+ .family = AF_INET,
-+ .match = portscan_mt,
-+ .checkentry = portscan_mt_check,
-+ .matchsize = sizeof(struct xt_portscan_match_info),
-+ .proto = IPPROTO_TCP,
-+ .me = THIS_MODULE,
-+};
-+
-+static int __init portscan_mt_init(void)
-+{
-+ return xt_register_match(&portscan_mt_reg);
-+}
-+
-+static void __exit portscan_mt_exit(void)
-+{
-+ xt_unregister_match(&portscan_mt_reg);
-+ return;
-+}
-+
-+module_init(portscan_mt_init);
-+module_exit(portscan_mt_exit);
-+MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
-+MODULE_DESCRIPTION("netfilter \"portscan\" match");
-+MODULE_LICENSE("GPL");
-+MODULE_ALIAS("ipt_portscan");
---- a/drivers/char/random.c
-+++ b/drivers/char/random.c
-@@ -1563,6 +1563,8 @@ __u32 secure_tcp_sequence_number(__be32
- return seq;
- }
-
-+EXPORT_SYMBOL(secure_tcp_sequence_number);
-+
- /* Generate secure starting point for ephemeral IPV4 transport port search */
- u32 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport)
- {
+++ /dev/null
---- a/net/netfilter/Kconfig
-+++ b/net/netfilter/Kconfig
-@@ -437,6 +437,23 @@ config NETFILTER_XT_TARGET_CONNSECMARK
-
- To compile it as a module, choose M here. If unsure, say N.
-
-+config NETFILTER_XT_TARGET_TARPIT
-+ tristate '"TARPIT" target support'
-+ depends on NETFILTER_XTABLES
-+ ---help---
-+ Adds a TARPIT target to iptables, which 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 does not require dedicated
-+ hardware or IPs. Any TCP port that you would normally DROP or REJECT
-+ can instead become a tarpit.
-+
- config NETFILTER_XT_TARGET_TCPMSS
- tristate '"TCPMSS" target support'
- depends on NETFILTER_XTABLES && (IPV6 || IPV6=n)
---- a/net/netfilter/Makefile
-+++ b/net/netfilter/Makefile
-@@ -47,6 +47,7 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_NFQUEUE
- obj-$(CONFIG_NETFILTER_XT_TARGET_NOTRACK) += xt_NOTRACK.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_RATEEST) += xt_RATEEST.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_SECMARK) += xt_SECMARK.o
-+obj-$(CONFIG_NETFILTER_XT_TARGET_TARPIT) += xt_TARPIT.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_TCPMSS) += xt_TCPMSS.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_TCPOPTSTRIP) += xt_TCPOPTSTRIP.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_TRACE) += xt_TRACE.o
---- /dev/null
-+++ b/net/netfilter/xt_TARPIT.c
-@@ -0,0 +1,279 @@
-+/*
-+ * Kernel module to capture and hold incoming TCP connections using
-+ * no local per-connection resources.
-+ *
-+ * Based on ipt_REJECT.c and offering functionality similar to
-+ * LaBrea <http://www.hackbusters.net/LaBrea/>.
-+ *
-+ * Copyright (c) 2002 Aaron Hopkins <tools@die.net>
-+ *
-+ * This program is free software; you can redistribute it and/or modify
-+ * it under the terms of the GNU General Public License as published by
-+ * the Free Software Foundation; either version 2 of the License, or
-+ * (at your option) any later version.
-+ *
-+ * This program is distributed in the hope that it will be useful,
-+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
-+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-+ * GNU General Public License for more details.
-+ *
-+ * You should have received a copy of the GNU General Public License
-+ * along with this program; if not, write to the Free Software
-+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-+ *
-+ * Goal:
-+ * - Allow incoming TCP connections to be established.
-+ * - Passing data should result in the connection being switched to the
-+ * persist state (0 byte window), in which the remote side stops sending
-+ * data and asks to continue every 60 seconds.
-+ * - Attempts to shut down the connection should be ignored completely, so
-+ * the remote side ends up having to time it out.
-+ *
-+ * This means:
-+ * - Reply to TCP SYN,!ACK,!RST,!FIN with SYN-ACK, window 5 bytes
-+ * - Reply to TCP SYN,ACK,!RST,!FIN with RST to prevent spoofing
-+ * - Reply to TCP !SYN,!RST,!FIN with ACK, window 0 bytes, rate-limited
-+ */
-+
-+#include <linux/version.h>
-+#include <linux/module.h>
-+#include <linux/skbuff.h>
-+#include <linux/ip.h>
-+#include <net/ip.h>
-+#include <net/tcp.h>
-+#include <net/icmp.h>
-+struct in_device;
-+#include <net/route.h>
-+#include <linux/random.h>
-+#include <linux/netfilter_ipv4/ip_tables.h>
-+
-+#if 0
-+#define DEBUGP printk
-+#else
-+#define DEBUGP(format, args...)
-+#endif
-+
-+/* Stolen from ip_finish_output2 */
-+static int ip_direct_send(struct sk_buff *skb)
-+{
-+ struct dst_entry *dst = skb->dst;
-+
-+ if (dst->hh != NULL)
-+ return neigh_hh_output(dst->hh, skb);
-+ else if (dst->neighbour != NULL)
-+ return dst->neighbour->output(skb);
-+
-+ if (net_ratelimit())
-+ printk(KERN_DEBUG "TARPIT ip_direct_send: no header cache and no neighbor!\n");
-+
-+ kfree_skb(skb);
-+ return -EINVAL;
-+}
-+
-+
-+/* Send reply */
-+static void tarpit_tcp(const struct sk_buff *oskb, struct rtable *ort,
-+ unsigned int local)
-+{
-+ struct sk_buff *nskb;
-+ struct rtable *nrt;
-+ struct tcphdr *otcph, *ntcph;
-+ struct flowi fl = {};
-+ unsigned int otcplen;
-+ u_int16_t tmp;
-+
-+ const struct iphdr *oiph = ip_hdr(oskb);
-+ struct iphdr *niph;
-+
-+ /* A truncated TCP header is not going to be useful */
-+ if (oskb->len < ip_hdrlen(oskb) + sizeof(struct tcphdr))
-+ return;
-+
-+ otcph = (void *)oiph + ip_hdrlen(oskb);
-+ otcplen = oskb->len - ip_hdrlen(oskb);
-+
-+ /* No replies for RST or FIN */
-+ if (otcph->rst || otcph->fin)
-+ return;
-+
-+ /* No reply to !SYN,!ACK. Rate-limit replies to !SYN,ACKs */
-+ if (!otcph->syn && (!otcph->ack || !xrlim_allow(&ort->u.dst, 1*HZ)))
-+ return;
-+
-+ /* Check checksum. */
-+ if (tcp_v4_check(otcplen, oiph->saddr, oiph->daddr,
-+ csum_partial((char *)otcph, otcplen, 0)) != 0)
-+ return;
-+
-+ /*
-+ * Copy skb (even if skb is about to be dropped, we cannot just
-+ * clone it because there may be other things, such as tcpdump,
-+ * interested in it)
-+ */
-+ nskb = skb_copy(oskb, GFP_ATOMIC);
-+ if (nskb == NULL)
-+ return;
-+
-+ niph = ip_hdr(nskb);
-+
-+ /* This packet will not be the same as the other: clear nf fields */
-+ nf_conntrack_put(nskb->nfct);
-+ nskb->nfct = NULL;
-+#ifdef CONFIG_NETFILTER_DEBUG
-+ nskb->nf_debug = 0;
-+#endif
-+
-+ ntcph = (void *)niph + ip_hdrlen(nskb);
-+
-+ /* Truncate to length (no data) */
-+ ntcph->doff = sizeof(struct tcphdr)/4;
-+ skb_trim(nskb, ip_hdrlen(nskb) + sizeof(struct tcphdr));
-+ niph->tot_len = htons(nskb->len);
-+
-+ /* Swap source and dest */
-+ niph->daddr = xchg(&niph->saddr, niph->daddr);
-+ tmp = ntcph->source;
-+ ntcph->source = ntcph->dest;
-+ ntcph->dest = tmp;
-+
-+ /* Use supplied sequence number or make a new one */
-+ ntcph->seq = otcph->ack ? otcph->ack_seq
-+ : htonl(secure_tcp_sequence_number(niph->saddr,
-+ niph->daddr,
-+ ntcph->source,
-+ ntcph->dest));
-+
-+ /* Our SYN-ACKs must have a >0 window */
-+ ntcph->window = (otcph->syn && !otcph->ack) ? htons(5) : 0;
-+
-+ ntcph->urg_ptr = 0;
-+
-+ /* Reset flags */
-+ ((u_int8_t *)ntcph)[13] = 0;
-+
-+ if (otcph->syn && otcph->ack) {
-+ ntcph->rst = 1;
-+ ntcph->ack_seq = 0;
-+ } else {
-+ ntcph->syn = otcph->syn;
-+ ntcph->ack = 1;
-+ ntcph->ack_seq = htonl(ntohl(otcph->seq) + otcph->syn);
-+ }
-+
-+ /* Adjust TCP checksum */
-+ ntcph->check = 0;
-+ ntcph->check = tcp_v4_check(sizeof(struct tcphdr),
-+ niph->saddr,
-+ niph->daddr,
-+ csum_partial((char *)ntcph,
-+ sizeof(struct tcphdr), 0));
-+
-+ fl.nl_u.ip4_u.daddr = niph->daddr;
-+ fl.nl_u.ip4_u.saddr = local ? niph->saddr : 0;
-+ fl.nl_u.ip4_u.tos = RT_TOS(niph->tos) | RTO_CONN;
-+ fl.oif = 0;
-+
-+ if (ip_route_output_key(&init_net, &nrt, &fl))
-+ goto free_nskb;
-+
-+ dst_release(nskb->dst);
-+ nskb->dst = &nrt->u.dst;
-+
-+ /* Adjust IP TTL */
-+ niph->ttl = dst_metric(nskb->dst, RTAX_HOPLIMIT);
-+
-+ /* Set DF, id = 0 */
-+ niph->frag_off = htons(IP_DF);
-+ niph->id = 0;
-+
-+ /* Adjust IP checksum */
-+ niph->check = 0;
-+ niph->check = ip_fast_csum((unsigned char *)niph, niph->ihl);
-+
-+ /* "Never happens" */
-+ if (nskb->len > dst_mtu(nskb->dst))
-+ goto free_nskb;
-+
-+ ip_direct_send(nskb);
-+ return;
-+
-+ free_nskb:
-+ kfree_skb(nskb);
-+}
-+
-+static unsigned int xt_tarpit_target(struct sk_buff *skb,
-+ const struct net_device *in,
-+ const struct net_device *out,
-+ unsigned int hooknum,
-+ const struct xt_target *target,
-+ const void *targinfo)
-+{
-+ const struct iphdr *iph = ip_hdr(skb);
-+ struct rtable *rt = (void *)skb->dst;
-+
-+ /* Do we have an input route cache entry? */
-+ if (rt == NULL)
-+ return NF_DROP;
-+
-+ /* No replies to physical multicast/broadcast */
-+ if (skb->pkt_type != PACKET_HOST && skb->pkt_type != PACKET_OTHERHOST)
-+ return NF_DROP;
-+
-+ /* Now check at the protocol level */
-+ if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
-+ return NF_DROP;
-+
-+ /*
-+ * Our naive response construction does not deal with IP
-+ * options, and probably should not try.
-+ */
-+ if (iph->ihl * 4 != sizeof(struct iphdr))
-+ return NF_DROP;
-+
-+ /* We are not interested in fragments */
-+ if (iph->frag_off & htons(IP_OFFSET))
-+ return NF_DROP;
-+
-+ tarpit_tcp(skb, rt, hooknum == NF_INET_LOCAL_IN);
-+ return NF_DROP;
-+}
-+
-+static bool xt_tarpit_check(const char *tablename, const void *entry,
-+ const struct xt_target *target, void *targinfo,
-+ unsigned int hook_mask)
-+{
-+ bool invalid;
-+
-+ if (strcmp(tablename, "raw") == 0 && hook_mask == NF_INET_PRE_ROUTING)
-+ return true;
-+ if (strcmp(tablename, "filter") != 0)
-+ return false;
-+ invalid = hook_mask & ~((1 << NF_INET_LOCAL_IN) | (1 << NF_INET_FORWARD));
-+ return !invalid;
-+}
-+
-+static struct xt_target xt_tarpit_reg = {
-+ .name = "TARPIT",
-+ .family = AF_INET,
-+ .proto = IPPROTO_TCP,
-+ .target = xt_tarpit_target,
-+ .checkentry = xt_tarpit_check,
-+ .me = THIS_MODULE,
-+};
-+
-+static int __init xt_tarpit_init(void)
-+{
-+ return xt_register_target(&xt_tarpit_reg);
-+}
-+
-+static void __exit xt_tarpit_exit(void)
-+{
-+ xt_unregister_target(&xt_tarpit_reg);
-+}
-+
-+module_init(xt_tarpit_init);
-+module_exit(xt_tarpit_exit);
-+MODULE_DESCRIPTION("netfilter xt_TARPIT target module");
-+MODULE_AUTHOR("Jan Engelhardt <jengelh@gmx.de>");
-+MODULE_LICENSE("GPL");
-+MODULE_ALIAS("ipt_TARPIT");
depends on NETFILTER_ADVANCED
help
H.323 is a VoIP signalling protocol from ITU-T. As one of the most
-@@ -456,7 +456,7 @@ config NETFILTER_XT_TARGET_TARPIT
+@@ -423,7 +423,7 @@ config NETFILTER_XT_TARGET_CONNSECMARK
config NETFILTER_XT_TARGET_TCPMSS
tristate '"TCPMSS" target support'
+++ /dev/null
---- a/include/linux/netfilter/Kbuild
-+++ b/include/linux/netfilter/Kbuild
-@@ -3,6 +3,7 @@ header-y += nf_conntrack_tuple_common.h
- header-y += nfnetlink_conntrack.h
- header-y += nfnetlink_log.h
- header-y += nfnetlink_queue.h
-+header-y += xt_CHAOS.h
- header-y += xt_CLASSIFY.h
- header-y += xt_CONNMARK.h
- header-y += xt_CONNSECMARK.h
---- /dev/null
-+++ b/include/linux/netfilter/oot_conntrack.h
-@@ -0,0 +1,5 @@
-+#if defined(CONFIG_IP_NF_CONNTRACK) || defined(CONFIG_IP_NF_CONNTRACK_MODULE)
-+# include <linux/netfilter_ipv4/ip_conntrack.h>
-+#else /* linux-2.6.20+ */
-+# include <net/netfilter/nf_nat_rule.h>
-+#endif
---- /dev/null
-+++ b/include/linux/netfilter/oot_trans.h
-@@ -0,0 +1,14 @@
-+/* Out of tree workarounds */
-+#include <linux/version.h>
-+#if LINUX_VERSION_CODE <= KERNEL_VERSION(2, 6, 18)
-+# define HAVE_MATCHINFOSIZE 1
-+# define HAVE_TARGUSERINFO 1
-+# define HAVE_TARGINFOSIZE 1
-+#endif
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 20)
-+# define nfmark mark
-+#endif
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 21)
-+# define tcp_v4_check(tcph, tcph_sz, s, d, csp) \
-+ tcp_v4_check((tcph_sz), (s), (d), (csp))
-+#endif
---- /dev/null
-+++ b/include/linux/netfilter/xt_CHAOS.h
-@@ -0,0 +1,14 @@
-+#ifndef _LINUX_NETFILTER_XT_CHAOS_H
-+#define _LINUX_NETFILTER_XT_CHAOS_H 1
-+
-+enum xt_chaos_target_variant {
-+ XTCHAOS_NORMAL,
-+ XTCHAOS_TARPIT,
-+ XTCHAOS_DELUDE,
-+};
-+
-+struct xt_chaos_target_info {
-+ uint8_t variant;
-+};
-+
-+#endif /* _LINUX_NETFILTER_XT_CHAOS_H */
---- /dev/null
-+++ b/include/linux/netfilter/xt_portscan.h
-@@ -0,0 +1,8 @@
-+#ifndef _LINUX_NETFILTER_XT_PORTSCAN_H
-+#define _LINUX_NETFILTER_XT_PORTSCAN_H 1
-+
-+struct xt_portscan_match_info {
-+ uint8_t match_stealth, match_syn, match_cn, match_gr;
-+};
-+
-+#endif /* _LINUX_NETFILTER_XT_PORTSCAN_H */
---- /dev/null
-+++ b/net/netfilter/find_match.c
-@@ -0,0 +1,39 @@
-+/*
-+ xt_request_find_match
-+ by Jan Engelhardt <jengelh [at] gmx de>, 2006 - 2007
-+
-+ Based upon linux-2.6.18.5/net/netfilter/x_tables.c:
-+ Copyright (C) 2006-2006 Harald Welte <laforge@netfilter.org>
-+ This program is free software; you can redistribute it and/or modify
-+ it under the terms of the GNU General Public License version 2 as
-+ published by the Free Software Foundation.
-+*/
-+#include <linux/err.h>
-+#include <linux/netfilter_arp.h>
-+#include <linux/socket.h>
-+#include <linux/netfilter/x_tables.h>
-+
-+/*
-+ * Yeah this code is sub-optimal, but the function is missing in
-+ * mainline so far. -jengelh
-+ */
-+static struct xt_match *xt_request_find_match_lo(int af, const char *name,
-+ u8 revision)
-+{
-+ static const char *const xt_prefix[] = {
-+ [AF_INET] = "ip",
-+ [AF_INET6] = "ip6",
-+ [NF_ARP] = "arp",
-+ };
-+ struct xt_match *match;
-+
-+ match = try_then_request_module(xt_find_match(af, name, revision),
-+ "%st_%s", xt_prefix[af], name);
-+ if (IS_ERR(match) || match == NULL)
-+ return NULL;
-+
-+ return match;
-+}
-+
-+/* In case it goes into mainline, let this out-of-tree package compile */
-+#define xt_request_find_match xt_request_find_match_lo
---- a/net/netfilter/Kconfig
-+++ b/net/netfilter/Kconfig
-@@ -288,6 +288,14 @@ config NETFILTER_XTABLES
-
- # alphabetically ordered list of targets
-
-+config NETFILTER_XT_TARGET_CHAOS
-+ tristate '"CHAOS" target support'
-+ depends on NETFILTER_XTABLES
-+ help
-+ This option adds a `CHAOS' target.
-+
-+ To compile it as a module, choose M here. If unsure, say N.
-+
- config NETFILTER_XT_TARGET_CLASSIFY
- tristate '"CLASSIFY" target support'
- depends on NETFILTER_XTABLES
-@@ -317,6 +325,14 @@ config NETFILTER_XT_TARGET_CONNMARK
- <file:Documentation/kbuild/modules.txt>. The module will be called
- ipt_CONNMARK.ko. If unsure, say `N'.
-
-+config NETFILTER_XT_TARGET_DELUDE
-+ tristate '"DELUDE" target support'
-+ depends on NETFILTER_XTABLES
-+ help
-+ This option adds a `DELUDE' target.
-+
-+ To compile it as a module, choose M here. If unsure, say N.
-+
- config NETFILTER_XT_TARGET_DSCP
- tristate '"DSCP" and "TOS" target support'
- depends on NETFILTER_XTABLES
-@@ -653,6 +669,14 @@ config NETFILTER_XT_MATCH_POLICY
-
- To compile it as a module, choose M here. If unsure, say N.
-
-+config NETFILTER_XT_MATCH_PORTSCAN
-+ tristate '"portscan" match support'
-+ depends on NETFILTER_XTABLES
-+ help
-+ This option adds a 'portscan' match support.
-+
-+ To compile it as a module, choose M here. If unsure, say N.
-+
- config NETFILTER_XT_MATCH_MULTIPORT
- tristate '"multiport" Multiple port match support'
- depends on NETFILTER_XTABLES
---- a/net/netfilter/Makefile
-+++ b/net/netfilter/Makefile
-@@ -51,6 +51,8 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_SECMARK
- obj-$(CONFIG_NETFILTER_XT_TARGET_TCPMSS) += xt_TCPMSS.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_TCPOPTSTRIP) += xt_TCPOPTSTRIP.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_TRACE) += xt_TRACE.o
-+obj-$(CONFIG_NETFILTER_XT_TARGET_CHAOS) += xt_CHAOS.o
-+obj-$(CONFIG_NETFILTER_XT_TARGET_DELUDE) += xt_DELUDE.o
-
- # matches
- obj-$(CONFIG_NETFILTER_XT_MATCH_COMMENT) += xt_comment.o
-@@ -84,3 +86,4 @@ obj-$(CONFIG_NETFILTER_XT_MATCH_STRING)
- obj-$(CONFIG_NETFILTER_XT_MATCH_TCPMSS) += xt_tcpmss.o
- obj-$(CONFIG_NETFILTER_XT_MATCH_TIME) += xt_time.o
- obj-$(CONFIG_NETFILTER_XT_MATCH_U32) += xt_u32.o
-+obj-$(CONFIG_NETFILTER_XT_MATCH_PORTSCAN) += xt_portscan.o
---- /dev/null
-+++ b/net/netfilter/xt_CHAOS.c
-@@ -0,0 +1,200 @@
-+/*
-+ * CHAOS target for netfilter
-+ * 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 <linux/icmp.h>
-+#include <linux/in.h>
-+#include <linux/ip.h>
-+#include <linux/module.h>
-+#include <linux/skbuff.h>
-+#include <linux/stat.h>
-+#include <linux/netfilter/x_tables.h>
-+#include <linux/netfilter/xt_tcpudp.h>
-+#include <linux/netfilter_ipv4/ipt_REJECT.h>
-+#include <net/ip.h>
-+#if defined(_LOCAL)
-+# include "xt_CHAOS.h"
-+# include "find_match.c"
-+#elif defined(CONFIG_NETFILTER_XT_TARGET_CHAOS) || \
-+ defined(CONFIG_NETFILTER_XT_TARGET_CHAOS_MODULE)
-+# include <linux/netfilter/xt_CHAOS.h>
-+# include "find_match.c"
-+#else
-+# include "xt_CHAOS.h"
-+# include "find_match.c"
-+#endif
-+#define PFX KBUILD_MODNAME ": "
-+
-+/* Module parameters */
-+static unsigned int reject_percentage = ~0U * .01;
-+static unsigned int delude_percentage = ~0U * .0101;
-+module_param(reject_percentage, uint, S_IRUGO | S_IWUSR);
-+module_param(delude_percentage, uint, S_IRUGO | S_IWUSR);
-+
-+/* References to other matches/targets */
-+static struct xt_match *xm_tcp;
-+static struct xt_target *xt_delude, *xt_reject, *xt_tarpit;
-+
-+static int have_delude, have_tarpit;
-+
-+/* Static data for other matches/targets */
-+static const struct ipt_reject_info reject_params = {
-+ .with = ICMP_HOST_UNREACH,
-+};
-+
-+static const struct xt_tcp tcp_params = {
-+ .spts = {0, ~0},
-+ .dpts = {0, ~0},
-+};
-+
-+/* CHAOS functions */
-+static void xt_chaos_total(const struct xt_chaos_target_info *info,
-+ struct sk_buff *skb, const struct net_device *in,
-+ const struct net_device *out, unsigned int hooknum)
-+{
-+ const struct iphdr *iph = ip_hdr(skb);
-+ const int protoff = 4 * iph->ihl;
-+ const int offset = ntohs(iph->frag_off) & IP_OFFSET;
-+ const struct xt_target *destiny;
-+ bool hotdrop = false, ret;
-+
-+ ret = xm_tcp->match(skb, in, out, xm_tcp, &tcp_params,
-+ offset, protoff, &hotdrop);
-+ if (!ret || hotdrop || (unsigned int)net_random() > delude_percentage)
-+ return;
-+
-+ destiny = (info->variant == XTCHAOS_TARPIT) ? xt_tarpit : xt_delude;
-+ destiny->target(skb, in, out, hooknum, destiny, NULL);
-+ return;
-+}
-+
-+static unsigned int chaos_tg(struct sk_buff *skb,
-+ const struct net_device *in, const struct net_device *out,
-+ unsigned int hooknum, const struct xt_target *target, const void *targinfo)
-+{
-+ /*
-+ * Equivalent to:
-+ * -A chaos -m statistic --mode random --probability \
-+ * $reject_percentage -j REJECT --reject-with host-unreach;
-+ * -A chaos -p tcp -m statistic --mode random --probability \
-+ * $delude_percentage -j DELUDE;
-+ * -A chaos -j DROP;
-+ */
-+ const struct xt_chaos_target_info *info = targinfo;
-+ const struct iphdr *iph = ip_hdr(skb);
-+
-+ if ((unsigned int)net_random() <= reject_percentage)
-+ return xt_reject->target(skb, in, out, hooknum, target,
-+ &reject_params);
-+
-+ /* TARPIT/DELUDE may not be called from the OUTPUT chain */
-+ if (iph->protocol == IPPROTO_TCP &&
-+ info->variant != XTCHAOS_NORMAL && hooknum != NF_INET_LOCAL_OUT)
-+ xt_chaos_total(info, skb, in, out, hooknum);
-+
-+ return NF_DROP;
-+}
-+
-+static bool chaos_tg_check(const char *tablename, const void *entry,
-+ const struct xt_target *target, void *targinfo, unsigned int hook_mask)
-+{
-+ const struct xt_chaos_target_info *info = targinfo;
-+
-+ if (info->variant == XTCHAOS_DELUDE && !have_delude) {
-+ printk(KERN_WARNING PFX "Error: Cannot use --delude when "
-+ "DELUDE module not available\n");
-+ return false;
-+ }
-+ if (info->variant == XTCHAOS_TARPIT && !have_tarpit) {
-+ printk(KERN_WARNING PFX "Error: Cannot use --tarpit when "
-+ "TARPIT module not available\n");
-+ return false;
-+ }
-+
-+ return true;
-+}
-+
-+static struct xt_target chaos_tg_reg = {
-+ .name = "CHAOS",
-+ .family = AF_INET,
-+ .table = "filter",
-+ .hooks = (1 << NF_INET_LOCAL_IN) | (1 << NF_INET_FORWARD) |
-+ (1 << NF_INET_LOCAL_OUT),
-+ .checkentry = chaos_tg_check,
-+ .target = chaos_tg,
-+ .targetsize = sizeof(struct xt_chaos_target_info),
-+ .me = THIS_MODULE,
-+};
-+
-+static int __init chaos_tg_init(void)
-+{
-+ int ret = -EINVAL;
-+
-+ xm_tcp = xt_request_find_match(AF_INET, "tcp", 0);
-+ if (xm_tcp == NULL) {
-+ printk(KERN_WARNING PFX "Error: Could not find or load "
-+ "\"tcp\" match\n");
-+ return -EINVAL;
-+ }
-+
-+ xt_reject = xt_request_find_target(AF_INET, "REJECT", 0);
-+ if (xt_reject == NULL) {
-+ printk(KERN_WARNING PFX "Error: Could not find or load "
-+ "\"REJECT\" target\n");
-+ goto out2;
-+ }
-+
-+ xt_tarpit = xt_request_find_target(AF_INET, "TARPIT", 0);
-+ have_tarpit = xt_tarpit != NULL;
-+ if (!have_tarpit)
-+ printk(KERN_WARNING PFX "Warning: Could not find or load "
-+ "\"TARPIT\" target\n");
-+
-+ xt_delude = xt_request_find_target(AF_INET, "DELUDE", 0);
-+ have_delude = xt_delude != NULL;
-+ if (!have_delude)
-+ printk(KERN_WARNING PFX "Warning: Could not find or load "
-+ "\"DELUDE\" target\n");
-+
-+ if ((ret = xt_register_target(&chaos_tg_reg)) != 0) {
-+ printk(KERN_WARNING PFX "xt_register_target returned "
-+ "error %d\n", ret);
-+ goto out3;
-+ }
-+
-+ return 0;
-+
-+ out3:
-+ if (have_delude)
-+ module_put(xt_delude->me);
-+ if (have_tarpit)
-+ module_put(xt_tarpit->me);
-+ module_put(xt_reject->me);
-+ out2:
-+ module_put(xm_tcp->me);
-+ return ret;
-+}
-+
-+static void __exit chaos_tg_exit(void)
-+{
-+ xt_unregister_target(&chaos_tg_reg);
-+ module_put(xm_tcp->me);
-+ module_put(xt_reject->me);
-+ if (have_delude)
-+ module_put(xt_delude->me);
-+ if (have_tarpit)
-+ module_put(xt_tarpit->me);
-+ return;
-+}
-+
-+module_init(chaos_tg_init);
-+module_exit(chaos_tg_exit);
-+MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
-+MODULE_DESCRIPTION("netfilter \"CHAOS\" target");
-+MODULE_LICENSE("GPL");
-+MODULE_ALIAS("ipt_CHAOS");
---- /dev/null
-+++ b/net/netfilter/xt_DELUDE.c
-@@ -0,0 +1,197 @@
-+/*
-+ * DELUDE target
-+ * Copyright © CC Computer Consultants GmbH, 2007
-+ * Contact: Jan Engelhardt <jengelh@computergmbh.de>
-+ *
-+ * Based upon linux-2.6.18.5/net/ipv4/netfilter/ipt_REJECT.c:
-+ * (C) 1999-2001 Paul `Rusty' Russell
-+ * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
-+ *
-+ * xt_DELUDE acts like REJECT, but does reply with SYN-ACK on SYN.
-+ *
-+ * This program is free software; you can redistribute it and/or modify
-+ * it under the terms of the GNU General Public License version 2 as
-+ * published by the Free Software Foundation.
-+ */
-+#include <linux/module.h>
-+#include <linux/skbuff.h>
-+#include <linux/ip.h>
-+#include <linux/tcp.h>
-+#include <linux/netfilter/x_tables.h>
-+#ifdef CONFIG_BRIDGE_NETFILTER
-+# include <linux/netfilter_bridge.h>
-+#endif
-+#include <net/tcp.h>
-+#define PFX KBUILD_MODNAME ": "
-+
-+static void delude_send_reset(struct sk_buff *oldskb, unsigned int hook)
-+{
-+ struct tcphdr _otcph, *oth, *tcph;
-+ unsigned int addr_type;
-+ struct sk_buff *nskb;
-+ u_int16_t tmp_port;
-+ u_int32_t tmp_addr;
-+ struct iphdr *niph;
-+ bool needs_ack;
-+
-+ /* IP header checks: fragment. */
-+ if (ip_hdr(oldskb)->frag_off & htons(IP_OFFSET))
-+ return;
-+
-+ oth = skb_header_pointer(oldskb, ip_hdrlen(oldskb),
-+ sizeof(_otcph), &_otcph);
-+ if (oth == NULL)
-+ return;
-+
-+ /* No RST for RST. */
-+ if (oth->rst)
-+ return;
-+
-+ /* Check checksum */
-+ if (nf_ip_checksum(oldskb, hook, ip_hdrlen(oldskb), IPPROTO_TCP))
-+ return;
-+
-+ /* We need a linear, writeable skb. We also need to expand
-+ headroom in case hh_len of incoming interface < hh_len of
-+ outgoing interface */
-+ nskb = skb_copy_expand(oldskb, LL_MAX_HEADER, skb_tailroom(oldskb),
-+ GFP_ATOMIC);
-+ if (!nskb)
-+ return;
-+
-+ /* This packet will not be the same as the other: clear nf fields */
-+ nf_reset(nskb);
-+ nskb->mark = 0;
-+ skb_init_secmark(nskb);
-+
-+ skb_shinfo(nskb)->gso_size = 0;
-+ skb_shinfo(nskb)->gso_segs = 0;
-+ skb_shinfo(nskb)->gso_type = 0;
-+
-+ tcph = (struct tcphdr *)(skb_network_header(nskb) + ip_hdrlen(nskb));
-+
-+ /* Swap source and dest */
-+ niph = ip_hdr(nskb);
-+ tmp_addr = niph->saddr;
-+ niph->saddr = niph->daddr;
-+ niph->daddr = tmp_addr;
-+ tmp_port = tcph->source;
-+ tcph->source = tcph->dest;
-+ tcph->dest = tmp_port;
-+
-+ /* Truncate to length (no data) */
-+ tcph->doff = sizeof(struct tcphdr) / 4;
-+ skb_trim(nskb, ip_hdrlen(nskb) + sizeof(struct tcphdr));
-+ niph->tot_len = htons(nskb->len);
-+
-+ if (oth->syn && !oth->ack && !oth->rst && !oth->fin) {
-+ /* DELUDE essential part */
-+ tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn + oth->fin +
-+ oldskb->len - ip_hdrlen(oldskb) -
-+ (oth->doff << 2));
-+ tcph->seq = false;
-+ tcph->ack = true;
-+ } else {
-+ if (!tcph->ack) {
-+ needs_ack = true;
-+ tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn +
-+ oth->fin + oldskb->len -
-+ ip_hdrlen(oldskb) - (oth->doff<<2));
-+ tcph->seq = false;
-+ } else {
-+ needs_ack = false;
-+ tcph->seq = oth->ack_seq;
-+ tcph->ack_seq = false;
-+ }
-+
-+ /* Reset flags */
-+ ((u_int8_t *)tcph)[13] = 0;
-+ tcph->rst = true;
-+ tcph->ack = needs_ack;
-+ }
-+
-+ tcph->window = 0;
-+ tcph->urg_ptr = 0;
-+
-+ /* Adjust TCP checksum */
-+ tcph->check = 0;
-+ tcph->check = tcp_v4_check(sizeof(struct tcphdr), niph->saddr,
-+ niph->daddr, csum_partial((char *)tcph,
-+ sizeof(struct tcphdr), 0));
-+
-+ /* Set DF, id = 0 */
-+ niph->frag_off = htons(IP_DF);
-+ niph->id = 0;
-+
-+ addr_type = RTN_UNSPEC;
-+#ifdef CONFIG_BRIDGE_NETFILTER
-+ if (hook != NF_INET_FORWARD || (nskb->nf_bridge != NULL &&
-+ nskb->nf_bridge->mask & BRNF_BRIDGED))
-+#else
-+ if (hook != NF_INET_FORWARD)
-+#endif
-+ addr_type = RTN_LOCAL;
-+
-+ if (ip_route_me_harder(nskb, addr_type))
-+ goto free_nskb;
-+
-+ nskb->ip_summed = CHECKSUM_NONE;
-+
-+ /* Adjust IP TTL */
-+ niph->ttl = dst_metric(nskb->dst, RTAX_HOPLIMIT);
-+
-+ /* Adjust IP checksum */
-+ niph->check = 0;
-+ niph->check = ip_fast_csum(skb_network_header(nskb), niph->ihl);
-+
-+ /* "Never happens" */
-+ if (nskb->len > dst_mtu(nskb->dst))
-+ goto free_nskb;
-+
-+ nf_ct_attach(nskb, oldskb);
-+
-+ NF_HOOK(PF_INET, NF_INET_LOCAL_OUT, nskb, NULL, nskb->dst->dev,
-+ dst_output);
-+ return;
-+
-+ free_nskb:
-+ kfree_skb(nskb);
-+}
-+
-+static unsigned int delude_tg(struct sk_buff *skb,
-+ const struct net_device *in, const struct net_device *out,
-+ unsigned int hooknum, const struct xt_target *target, const void *targinfo)
-+{
-+ /* WARNING: This code causes reentry within iptables.
-+ This means that the iptables jump stack is now crap. We
-+ must return an absolute verdict. --RR */
-+ delude_send_reset(skb, hooknum);
-+ return NF_DROP;
-+}
-+
-+static struct xt_target delude_tg_reg = {
-+ .name = "DELUDE",
-+ .family = AF_INET,
-+ .table = "filter",
-+ .hooks = (1 << NF_INET_LOCAL_IN) | (1 << NF_INET_FORWARD),
-+ .target = delude_tg,
-+ .proto = IPPROTO_TCP,
-+ .me = THIS_MODULE,
-+};
-+
-+static int __init delude_tg_init(void)
-+{
-+ return xt_register_target(&delude_tg_reg);
-+}
-+
-+static void __exit delude_tg_exit(void)
-+{
-+ xt_unregister_target(&delude_tg_reg);
-+}
-+
-+module_init(delude_tg_init);
-+module_exit(delude_tg_exit);
-+MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
-+MODULE_DESCRIPTION("netfilter \"DELUDE\" target");
-+MODULE_LICENSE("GPL");
-+MODULE_ALIAS("ipt_DELUDE");
---- /dev/null
-+++ b/net/netfilter/xt_portscan.c
-@@ -0,0 +1,269 @@
-+/*
-+ * portscan match for netfilter
-+ * 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 <linux/in.h>
-+#include <linux/ip.h>
-+#include <linux/module.h>
-+#include <linux/moduleparam.h>
-+#include <linux/skbuff.h>
-+#include <linux/stat.h>
-+#include <linux/tcp.h>
-+#include <linux/types.h>
-+#include <linux/version.h>
-+#include <linux/netfilter/x_tables.h>
-+#include <linux/netfilter/xt_tcpudp.h>
-+#include <net/netfilter/nf_nat_rule.h>
-+#if defined(_LOCAL)
-+# include "xt_portscan.h"
-+#elif defined(CONFIG_NETFILTER_XT_MATCH_PORTSCAN) || \
-+ defined(CONFIG_NETFILTER_XT_MATCH_PORTSCAN_MODULE)
-+# include <linux/netfilter/xt_portscan.h>
-+#else
-+# include "xt_portscan.h"
-+#endif
-+#define PFX KBUILD_MODNAME ": "
-+
-+enum {
-+ TCP_FLAGS_ALL3 = TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_SYN,
-+ TCP_FLAGS_ALL4 = TCP_FLAGS_ALL3 | TCP_FLAG_ACK,
-+ TCP_FLAGS_ALL6 = TCP_FLAGS_ALL4 | TCP_FLAG_PSH | TCP_FLAG_URG,
-+};
-+
-+/* Module parameters */
-+static unsigned int
-+ connmark_mask = ~0,
-+ packet_mask = ~0,
-+ mark_seen = 0x9,
-+ mark_synrcv = 0x1,
-+ mark_closed = 0x2,
-+ mark_synscan = 0x3,
-+ mark_estab1 = 0x4,
-+ mark_estab2 = 0x5,
-+ mark_cnscan = 0x6,
-+ mark_grscan = 0x7,
-+ mark_valid = 0x8;
-+
-+module_param(connmark_mask, uint, S_IRUGO | S_IWUSR);
-+module_param(packet_mask, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_seen, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_synrcv, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_closed, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_synscan, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_estab1, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_estab2, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_cnscan, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_grscan, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_valid, uint, S_IRUGO | S_IWUSR);
-+MODULE_PARM_DESC(connmark_mask, "only set specified bits in connection mark");
-+MODULE_PARM_DESC(packet_mask, "only set specified bits in packet mark");
-+MODULE_PARM_DESC(mark_seen, "nfmark value for packet-seen state");
-+MODULE_PARM_DESC(mark_synrcv, "connmark value for SYN Received state");
-+MODULE_PARM_DESC(mark_closed, "connmark value for closed state");
-+MODULE_PARM_DESC(mark_synscan, "connmark value for SYN Scan state");
-+MODULE_PARM_DESC(mark_estab1, "connmark value for Established-1 state");
-+MODULE_PARM_DESC(mark_estab2, "connmark value for Established-2 state");
-+MODULE_PARM_DESC(mark_cnscan, "connmark value for Connect Scan state");
-+MODULE_PARM_DESC(mark_grscan, "connmark value for Grab Scan state");
-+MODULE_PARM_DESC(mark_valid, "connmark value for Valid state");
-+
-+/* TCP flag functions */
-+static inline bool tflg_ack4(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL4) == TCP_FLAG_ACK;
-+}
-+
-+static inline bool tflg_ack6(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL6) == TCP_FLAG_ACK;
-+}
-+
-+static inline bool tflg_fin(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL3) == TCP_FLAG_FIN;
-+}
-+
-+static inline bool tflg_rst(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL3) == TCP_FLAG_RST;
-+}
-+
-+static inline bool tflg_rstack(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL4) ==
-+ (TCP_FLAG_ACK | TCP_FLAG_RST);
-+}
-+
-+static inline bool tflg_syn(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL4) == TCP_FLAG_SYN;
-+}
-+
-+static inline bool tflg_synack(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL4) ==
-+ (TCP_FLAG_SYN | TCP_FLAG_ACK);
-+}
-+
-+/* portscan functions */
-+static inline bool portscan_mt_stealth(const struct tcphdr *th)
-+{
-+ /*
-+ * "Connection refused" replies to our own probes must not be matched.
-+ */
-+ if (tflg_rstack(th))
-+ return false;
-+
-+ if (tflg_rst(th) && printk_ratelimit()) {
-+ printk(KERN_WARNING PFX "Warning: Pure RST received\n");
-+ return false;
-+ }
-+
-+ /*
-+ * -p tcp ! --syn -m conntrack --ctstate INVALID: Looking for non-start
-+ * packets that are not associated with any connection -- this will
-+ * match most scan types (NULL, XMAS, FIN) and ridiculous flag
-+ * combinations (SYN-RST, SYN-FIN, SYN-FIN-RST, FIN-RST, etc.).
-+ */
-+ return !tflg_syn(th);
-+}
-+
-+static inline unsigned int portscan_mt_full(int mark,
-+ enum ip_conntrack_info ctstate, bool loopback, const struct tcphdr *tcph,
-+ unsigned int payload_len)
-+{
-+ if (mark == mark_estab2) {
-+ /*
-+ * -m connmark --mark $ESTAB2
-+ */
-+ if (tflg_ack4(tcph) && payload_len == 0)
-+ return mark; /* keep mark */
-+ else if (tflg_rst(tcph) || tflg_fin(tcph))
-+ return mark_grscan;
-+ else
-+ return mark_valid;
-+ } else if (mark == mark_estab1) {
-+ /*
-+ * -m connmark --mark $ESTAB1
-+ */
-+ if (tflg_rst(tcph) || tflg_fin(tcph))
-+ return mark_cnscan;
-+ else if (!loopback && tflg_ack4(tcph) && payload_len == 0)
-+ return mark_estab2;
-+ else
-+ return mark_valid;
-+ } else if (mark == mark_synrcv) {
-+ /*
-+ * -m connmark --mark $SYN
-+ */
-+ if (loopback && tflg_synack(tcph))
-+ return mark; /* keep mark */
-+ else if (loopback && tflg_rstack(tcph))
-+ return mark_closed;
-+ else if (tflg_ack6(tcph))
-+ return mark_estab1;
-+ else
-+ return mark_synscan;
-+ } else if (ctstate == IP_CT_NEW && tflg_syn(tcph)) {
-+ /*
-+ * -p tcp --syn --ctstate NEW
-+ */
-+ return mark_synrcv;
-+ }
-+ return mark;
-+}
-+
-+static bool portscan_mt(const struct sk_buff *skb,
-+ const struct net_device *in, const struct net_device *out,
-+ const struct xt_match *match, const void *matchinfo, int offset,
-+ unsigned int protoff, bool *hotdrop)
-+{
-+ const struct xt_portscan_match_info *info = matchinfo;
-+ enum ip_conntrack_info ctstate;
-+ const struct tcphdr *tcph;
-+ struct nf_conn *ctdata;
-+ struct tcphdr tcph_buf;
-+
-+ tcph = skb_header_pointer(skb, protoff, sizeof(tcph_buf), &tcph_buf);
-+ if (tcph == NULL)
-+ return false;
-+
-+ /* Check for invalid packets: -m conntrack --ctstate INVALID */
-+ if ((ctdata = nf_ct_get(skb, &ctstate)) == NULL) {
-+ if (info->match_stealth)
-+ return portscan_mt_stealth(tcph);
-+ /*
-+ * If @ctdata is NULL, we cannot match the other scan
-+ * types, return.
-+ */
-+ return false;
-+ }
-+
-+ /*
-+ * If -m portscan was previously applied to this packet, the rules we
-+ * simulate must not be run through again. And for speedup, do not call
-+ * it either when the connection is already VALID.
-+ */
-+ if ((ctdata->mark & connmark_mask) == mark_valid ||
-+ (skb->mark & packet_mask) != mark_seen) {
-+ unsigned int n;
-+
-+ n = portscan_mt_full(ctdata->mark & connmark_mask, ctstate,
-+ (in->flags & IFF_LOOPBACK) == IFF_LOOPBACK, tcph,
-+ skb->len - protoff - 4 * tcph->doff);
-+
-+ ctdata->mark = (ctdata->mark & ~connmark_mask) | n;
-+ ((struct sk_buff *)skb)->mark =
-+ (skb->mark & ~packet_mask) ^ mark_seen;
-+ }
-+
-+ return (info->match_syn && ctdata->mark == mark_synscan) ||
-+ (info->match_cn && ctdata->mark == mark_cnscan) ||
-+ (info->match_gr && ctdata->mark == mark_grscan);
-+}
-+
-+static bool portscan_mt_check(const char *tablename, const void *entry,
-+ const struct xt_match *match, void *matchinfo, unsigned int hook_mask)
-+{
-+ const struct xt_portscan_match_info *info = matchinfo;
-+
-+ if ((info->match_stealth & ~1) || (info->match_syn & ~1) ||
-+ (info->match_cn & ~1) || (info->match_gr & ~1)) {
-+ printk(KERN_WARNING PFX "Invalid flags\n");
-+ return false;
-+ }
-+ return true;
-+}
-+
-+static struct xt_match portscan_mt_reg __read_mostly = {
-+ .name = "portscan",
-+ .family = AF_INET,
-+ .match = portscan_mt,
-+ .checkentry = portscan_mt_check,
-+ .matchsize = sizeof(struct xt_portscan_match_info),
-+ .proto = IPPROTO_TCP,
-+ .me = THIS_MODULE,
-+};
-+
-+static int __init portscan_mt_init(void)
-+{
-+ return xt_register_match(&portscan_mt_reg);
-+}
-+
-+static void __exit portscan_mt_exit(void)
-+{
-+ xt_unregister_match(&portscan_mt_reg);
-+ return;
-+}
-+
-+module_init(portscan_mt_init);
-+module_exit(portscan_mt_exit);
-+MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
-+MODULE_DESCRIPTION("netfilter \"portscan\" match");
-+MODULE_LICENSE("GPL");
-+MODULE_ALIAS("ipt_portscan");
---- a/drivers/char/random.c
-+++ b/drivers/char/random.c
-@@ -1554,6 +1554,8 @@ __u32 secure_tcp_sequence_number(__be32
- return seq;
- }
-
-+EXPORT_SYMBOL(secure_tcp_sequence_number);
-+
- /* Generate secure starting point for ephemeral IPV4 transport port search */
- u32 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport)
- {
+++ /dev/null
---- a/net/netfilter/Kconfig
-+++ b/net/netfilter/Kconfig
-@@ -449,6 +449,23 @@ config NETFILTER_XT_TARGET_CONNSECMARK
-
- To compile it as a module, choose M here. If unsure, say N.
-
-+config NETFILTER_XT_TARGET_TARPIT
-+ tristate '"TARPIT" target support'
-+ depends on NETFILTER_XTABLES
-+ ---help---
-+ Adds a TARPIT target to iptables, which 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 does not require dedicated
-+ hardware or IPs. Any TCP port that you would normally DROP or REJECT
-+ can instead become a tarpit.
-+
- config NETFILTER_XT_TARGET_TCPMSS
- tristate '"TCPMSS" target support'
- depends on NETFILTER_XTABLES && (IPV6 || IPV6=n)
---- a/net/netfilter/Makefile
-+++ b/net/netfilter/Makefile
-@@ -48,6 +48,7 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_NFQUEUE
- obj-$(CONFIG_NETFILTER_XT_TARGET_NOTRACK) += xt_NOTRACK.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_RATEEST) += xt_RATEEST.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_SECMARK) += xt_SECMARK.o
-+obj-$(CONFIG_NETFILTER_XT_TARGET_TARPIT) += xt_TARPIT.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_TCPMSS) += xt_TCPMSS.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_TCPOPTSTRIP) += xt_TCPOPTSTRIP.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_TRACE) += xt_TRACE.o
---- /dev/null
-+++ b/net/netfilter/xt_TARPIT.c
-@@ -0,0 +1,279 @@
-+/*
-+ * Kernel module to capture and hold incoming TCP connections using
-+ * no local per-connection resources.
-+ *
-+ * Based on ipt_REJECT.c and offering functionality similar to
-+ * LaBrea <http://www.hackbusters.net/LaBrea/>.
-+ *
-+ * Copyright (c) 2002 Aaron Hopkins <tools@die.net>
-+ *
-+ * This program is free software; you can redistribute it and/or modify
-+ * it under the terms of the GNU General Public License as published by
-+ * the Free Software Foundation; either version 2 of the License, or
-+ * (at your option) any later version.
-+ *
-+ * This program is distributed in the hope that it will be useful,
-+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
-+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-+ * GNU General Public License for more details.
-+ *
-+ * You should have received a copy of the GNU General Public License
-+ * along with this program; if not, write to the Free Software
-+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-+ *
-+ * Goal:
-+ * - Allow incoming TCP connections to be established.
-+ * - Passing data should result in the connection being switched to the
-+ * persist state (0 byte window), in which the remote side stops sending
-+ * data and asks to continue every 60 seconds.
-+ * - Attempts to shut down the connection should be ignored completely, so
-+ * the remote side ends up having to time it out.
-+ *
-+ * This means:
-+ * - Reply to TCP SYN,!ACK,!RST,!FIN with SYN-ACK, window 5 bytes
-+ * - Reply to TCP SYN,ACK,!RST,!FIN with RST to prevent spoofing
-+ * - Reply to TCP !SYN,!RST,!FIN with ACK, window 0 bytes, rate-limited
-+ */
-+
-+#include <linux/version.h>
-+#include <linux/module.h>
-+#include <linux/skbuff.h>
-+#include <linux/ip.h>
-+#include <net/ip.h>
-+#include <net/tcp.h>
-+#include <net/icmp.h>
-+struct in_device;
-+#include <net/route.h>
-+#include <linux/random.h>
-+#include <linux/netfilter_ipv4/ip_tables.h>
-+
-+#if 0
-+#define DEBUGP printk
-+#else
-+#define DEBUGP(format, args...)
-+#endif
-+
-+/* Stolen from ip_finish_output2 */
-+static int ip_direct_send(struct sk_buff *skb)
-+{
-+ struct dst_entry *dst = skb->dst;
-+
-+ if (dst->hh != NULL)
-+ return neigh_hh_output(dst->hh, skb);
-+ else if (dst->neighbour != NULL)
-+ return dst->neighbour->output(skb);
-+
-+ if (net_ratelimit())
-+ printk(KERN_DEBUG "TARPIT ip_direct_send: no header cache and no neighbor!\n");
-+
-+ kfree_skb(skb);
-+ return -EINVAL;
-+}
-+
-+
-+/* Send reply */
-+static void tarpit_tcp(const struct sk_buff *oskb, struct rtable *ort,
-+ unsigned int local)
-+{
-+ struct sk_buff *nskb;
-+ struct rtable *nrt;
-+ struct tcphdr *otcph, *ntcph;
-+ struct flowi fl = {};
-+ unsigned int otcplen;
-+ u_int16_t tmp;
-+
-+ const struct iphdr *oiph = ip_hdr(oskb);
-+ struct iphdr *niph;
-+
-+ /* A truncated TCP header is not going to be useful */
-+ if (oskb->len < ip_hdrlen(oskb) + sizeof(struct tcphdr))
-+ return;
-+
-+ otcph = (void *)oiph + ip_hdrlen(oskb);
-+ otcplen = oskb->len - ip_hdrlen(oskb);
-+
-+ /* No replies for RST or FIN */
-+ if (otcph->rst || otcph->fin)
-+ return;
-+
-+ /* No reply to !SYN,!ACK. Rate-limit replies to !SYN,ACKs */
-+ if (!otcph->syn && (!otcph->ack || !xrlim_allow(&ort->u.dst, 1*HZ)))
-+ return;
-+
-+ /* Check checksum. */
-+ if (tcp_v4_check(otcplen, oiph->saddr, oiph->daddr,
-+ csum_partial((char *)otcph, otcplen, 0)) != 0)
-+ return;
-+
-+ /*
-+ * Copy skb (even if skb is about to be dropped, we cannot just
-+ * clone it because there may be other things, such as tcpdump,
-+ * interested in it)
-+ */
-+ nskb = skb_copy(oskb, GFP_ATOMIC);
-+ if (nskb == NULL)
-+ return;
-+
-+ niph = ip_hdr(nskb);
-+
-+ /* This packet will not be the same as the other: clear nf fields */
-+ nf_conntrack_put(nskb->nfct);
-+ nskb->nfct = NULL;
-+#ifdef CONFIG_NETFILTER_DEBUG
-+ nskb->nf_debug = 0;
-+#endif
-+
-+ ntcph = (void *)niph + ip_hdrlen(nskb);
-+
-+ /* Truncate to length (no data) */
-+ ntcph->doff = sizeof(struct tcphdr)/4;
-+ skb_trim(nskb, ip_hdrlen(nskb) + sizeof(struct tcphdr));
-+ niph->tot_len = htons(nskb->len);
-+
-+ /* Swap source and dest */
-+ niph->daddr = xchg(&niph->saddr, niph->daddr);
-+ tmp = ntcph->source;
-+ ntcph->source = ntcph->dest;
-+ ntcph->dest = tmp;
-+
-+ /* Use supplied sequence number or make a new one */
-+ ntcph->seq = otcph->ack ? otcph->ack_seq
-+ : htonl(secure_tcp_sequence_number(niph->saddr,
-+ niph->daddr,
-+ ntcph->source,
-+ ntcph->dest));
-+
-+ /* Our SYN-ACKs must have a >0 window */
-+ ntcph->window = (otcph->syn && !otcph->ack) ? htons(5) : 0;
-+
-+ ntcph->urg_ptr = 0;
-+
-+ /* Reset flags */
-+ ((u_int8_t *)ntcph)[13] = 0;
-+
-+ if (otcph->syn && otcph->ack) {
-+ ntcph->rst = 1;
-+ ntcph->ack_seq = 0;
-+ } else {
-+ ntcph->syn = otcph->syn;
-+ ntcph->ack = 1;
-+ ntcph->ack_seq = htonl(ntohl(otcph->seq) + otcph->syn);
-+ }
-+
-+ /* Adjust TCP checksum */
-+ ntcph->check = 0;
-+ ntcph->check = tcp_v4_check(sizeof(struct tcphdr),
-+ niph->saddr,
-+ niph->daddr,
-+ csum_partial((char *)ntcph,
-+ sizeof(struct tcphdr), 0));
-+
-+ fl.nl_u.ip4_u.daddr = niph->daddr;
-+ fl.nl_u.ip4_u.saddr = local ? niph->saddr : 0;
-+ fl.nl_u.ip4_u.tos = RT_TOS(niph->tos) | RTO_CONN;
-+ fl.oif = 0;
-+
-+ if (ip_route_output_key(&init_net, &nrt, &fl))
-+ goto free_nskb;
-+
-+ dst_release(nskb->dst);
-+ nskb->dst = &nrt->u.dst;
-+
-+ /* Adjust IP TTL */
-+ niph->ttl = dst_metric(nskb->dst, RTAX_HOPLIMIT);
-+
-+ /* Set DF, id = 0 */
-+ niph->frag_off = htons(IP_DF);
-+ niph->id = 0;
-+
-+ /* Adjust IP checksum */
-+ niph->check = 0;
-+ niph->check = ip_fast_csum((unsigned char *)niph, niph->ihl);
-+
-+ /* "Never happens" */
-+ if (nskb->len > dst_mtu(nskb->dst))
-+ goto free_nskb;
-+
-+ ip_direct_send(nskb);
-+ return;
-+
-+ free_nskb:
-+ kfree_skb(nskb);
-+}
-+
-+static unsigned int xt_tarpit_target(struct sk_buff *skb,
-+ const struct net_device *in,
-+ const struct net_device *out,
-+ unsigned int hooknum,
-+ const struct xt_target *target,
-+ const void *targinfo)
-+{
-+ const struct iphdr *iph = ip_hdr(skb);
-+ struct rtable *rt = (void *)skb->dst;
-+
-+ /* Do we have an input route cache entry? */
-+ if (rt == NULL)
-+ return NF_DROP;
-+
-+ /* No replies to physical multicast/broadcast */
-+ if (skb->pkt_type != PACKET_HOST && skb->pkt_type != PACKET_OTHERHOST)
-+ return NF_DROP;
-+
-+ /* Now check at the protocol level */
-+ if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
-+ return NF_DROP;
-+
-+ /*
-+ * Our naive response construction does not deal with IP
-+ * options, and probably should not try.
-+ */
-+ if (iph->ihl * 4 != sizeof(struct iphdr))
-+ return NF_DROP;
-+
-+ /* We are not interested in fragments */
-+ if (iph->frag_off & htons(IP_OFFSET))
-+ return NF_DROP;
-+
-+ tarpit_tcp(skb, rt, hooknum == NF_INET_LOCAL_IN);
-+ return NF_DROP;
-+}
-+
-+static bool xt_tarpit_check(const char *tablename, const void *entry,
-+ const struct xt_target *target, void *targinfo,
-+ unsigned int hook_mask)
-+{
-+ bool invalid;
-+
-+ if (strcmp(tablename, "raw") == 0 && hook_mask == NF_INET_PRE_ROUTING)
-+ return true;
-+ if (strcmp(tablename, "filter") != 0)
-+ return false;
-+ invalid = hook_mask & ~((1 << NF_INET_LOCAL_IN) | (1 << NF_INET_FORWARD));
-+ return !invalid;
-+}
-+
-+static struct xt_target xt_tarpit_reg = {
-+ .name = "TARPIT",
-+ .family = AF_INET,
-+ .proto = IPPROTO_TCP,
-+ .target = xt_tarpit_target,
-+ .checkentry = xt_tarpit_check,
-+ .me = THIS_MODULE,
-+};
-+
-+static int __init xt_tarpit_init(void)
-+{
-+ return xt_register_target(&xt_tarpit_reg);
-+}
-+
-+static void __exit xt_tarpit_exit(void)
-+{
-+ xt_unregister_target(&xt_tarpit_reg);
-+}
-+
-+module_init(xt_tarpit_init);
-+module_exit(xt_tarpit_exit);
-+MODULE_DESCRIPTION("netfilter xt_TARPIT target module");
-+MODULE_AUTHOR("Jan Engelhardt <jengelh@gmx.de>");
-+MODULE_LICENSE("GPL");
-+MODULE_ALIAS("ipt_TARPIT");
depends on NETFILTER_ADVANCED
help
H.323 is a VoIP signalling protocol from ITU-T. As one of the most
-@@ -468,7 +468,7 @@ config NETFILTER_XT_TARGET_TARPIT
+@@ -435,7 +435,7 @@ config NETFILTER_XT_TARGET_CONNSECMARK
config NETFILTER_XT_TARGET_TCPMSS
tristate '"TCPMSS" target support'
+++ /dev/null
---- a/include/linux/netfilter/Kbuild
-+++ b/include/linux/netfilter/Kbuild
-@@ -3,6 +3,7 @@ header-y += nf_conntrack_tuple_common.h
- header-y += nfnetlink_conntrack.h
- header-y += nfnetlink_log.h
- header-y += nfnetlink_queue.h
-+header-y += xt_CHAOS.h
- header-y += xt_CLASSIFY.h
- header-y += xt_CONNMARK.h
- header-y += xt_CONNSECMARK.h
---- /dev/null
-+++ b/include/linux/netfilter/oot_conntrack.h
-@@ -0,0 +1,5 @@
-+#if defined(CONFIG_IP_NF_CONNTRACK) || defined(CONFIG_IP_NF_CONNTRACK_MODULE)
-+# include <linux/netfilter_ipv4/ip_conntrack.h>
-+#else /* linux-2.6.20+ */
-+# include <net/netfilter/nf_nat_rule.h>
-+#endif
---- /dev/null
-+++ b/include/linux/netfilter/oot_trans.h
-@@ -0,0 +1,14 @@
-+/* Out of tree workarounds */
-+#include <linux/version.h>
-+#if LINUX_VERSION_CODE <= KERNEL_VERSION(2, 6, 18)
-+# define HAVE_MATCHINFOSIZE 1
-+# define HAVE_TARGUSERINFO 1
-+# define HAVE_TARGINFOSIZE 1
-+#endif
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 20)
-+# define nfmark mark
-+#endif
-+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 21)
-+# define tcp_v4_check(tcph, tcph_sz, s, d, csp) \
-+ tcp_v4_check((tcph_sz), (s), (d), (csp))
-+#endif
---- /dev/null
-+++ b/include/linux/netfilter/xt_CHAOS.h
-@@ -0,0 +1,14 @@
-+#ifndef _LINUX_NETFILTER_XT_CHAOS_H
-+#define _LINUX_NETFILTER_XT_CHAOS_H 1
-+
-+enum xt_chaos_target_variant {
-+ XTCHAOS_NORMAL,
-+ XTCHAOS_TARPIT,
-+ XTCHAOS_DELUDE,
-+};
-+
-+struct xt_chaos_target_info {
-+ uint8_t variant;
-+};
-+
-+#endif /* _LINUX_NETFILTER_XT_CHAOS_H */
---- /dev/null
-+++ b/include/linux/netfilter/xt_portscan.h
-@@ -0,0 +1,8 @@
-+#ifndef _LINUX_NETFILTER_XT_PORTSCAN_H
-+#define _LINUX_NETFILTER_XT_PORTSCAN_H 1
-+
-+struct xt_portscan_match_info {
-+ uint8_t match_stealth, match_syn, match_cn, match_gr;
-+};
-+
-+#endif /* _LINUX_NETFILTER_XT_PORTSCAN_H */
---- /dev/null
-+++ b/net/netfilter/find_match.c
-@@ -0,0 +1,39 @@
-+/*
-+ xt_request_find_match
-+ by Jan Engelhardt <jengelh [at] gmx de>, 2006 - 2007
-+
-+ Based upon linux-2.6.18.5/net/netfilter/x_tables.c:
-+ Copyright (C) 2006-2006 Harald Welte <laforge@netfilter.org>
-+ This program is free software; you can redistribute it and/or modify
-+ it under the terms of the GNU General Public License version 2 as
-+ published by the Free Software Foundation.
-+*/
-+#include <linux/err.h>
-+#include <linux/netfilter_arp.h>
-+#include <linux/socket.h>
-+#include <linux/netfilter/x_tables.h>
-+
-+/*
-+ * Yeah this code is sub-optimal, but the function is missing in
-+ * mainline so far. -jengelh
-+ */
-+static struct xt_match *xt_request_find_match_lo(int af, const char *name,
-+ u8 revision)
-+{
-+ static const char *const xt_prefix[] = {
-+ [AF_INET] = "ip",
-+ [AF_INET6] = "ip6",
-+ [NF_ARP] = "arp",
-+ };
-+ struct xt_match *match;
-+
-+ match = try_then_request_module(xt_find_match(af, name, revision),
-+ "%st_%s", xt_prefix[af], name);
-+ if (IS_ERR(match) || match == NULL)
-+ return NULL;
-+
-+ return match;
-+}
-+
-+/* In case it goes into mainline, let this out-of-tree package compile */
-+#define xt_request_find_match xt_request_find_match_lo
---- a/net/netfilter/Kconfig
-+++ b/net/netfilter/Kconfig
-@@ -296,6 +296,14 @@ config NETFILTER_XTABLES
-
- # alphabetically ordered list of targets
-
-+config NETFILTER_XT_TARGET_CHAOS
-+ tristate '"CHAOS" target support'
-+ depends on NETFILTER_XTABLES
-+ help
-+ This option adds a `CHAOS' target.
-+
-+ To compile it as a module, choose M here. If unsure, say N.
-+
- config NETFILTER_XT_TARGET_CLASSIFY
- tristate '"CLASSIFY" target support'
- depends on NETFILTER_XTABLES
-@@ -325,6 +333,14 @@ config NETFILTER_XT_TARGET_CONNMARK
- <file:Documentation/kbuild/modules.txt>. The module will be called
- ipt_CONNMARK.ko. If unsure, say `N'.
-
-+config NETFILTER_XT_TARGET_DELUDE
-+ tristate '"DELUDE" target support'
-+ depends on NETFILTER_XTABLES
-+ help
-+ This option adds a `DELUDE' target.
-+
-+ To compile it as a module, choose M here. If unsure, say N.
-+
- config NETFILTER_XT_TARGET_DSCP
- tristate '"DSCP" and "TOS" target support'
- depends on NETFILTER_XTABLES
-@@ -661,6 +677,14 @@ config NETFILTER_XT_MATCH_POLICY
-
- To compile it as a module, choose M here. If unsure, say N.
-
-+config NETFILTER_XT_MATCH_PORTSCAN
-+ tristate '"portscan" match support'
-+ depends on NETFILTER_XTABLES
-+ help
-+ This option adds a 'portscan' match support.
-+
-+ To compile it as a module, choose M here. If unsure, say N.
-+
- config NETFILTER_XT_MATCH_MULTIPORT
- tristate '"multiport" Multiple port match support'
- depends on NETFILTER_XTABLES
---- a/net/netfilter/Makefile
-+++ b/net/netfilter/Makefile
-@@ -51,6 +51,8 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_SECMARK
- obj-$(CONFIG_NETFILTER_XT_TARGET_TCPMSS) += xt_TCPMSS.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_TCPOPTSTRIP) += xt_TCPOPTSTRIP.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_TRACE) += xt_TRACE.o
-+obj-$(CONFIG_NETFILTER_XT_TARGET_CHAOS) += xt_CHAOS.o
-+obj-$(CONFIG_NETFILTER_XT_TARGET_DELUDE) += xt_DELUDE.o
-
- # matches
- obj-$(CONFIG_NETFILTER_XT_MATCH_COMMENT) += xt_comment.o
-@@ -84,3 +86,4 @@ obj-$(CONFIG_NETFILTER_XT_MATCH_STRING)
- obj-$(CONFIG_NETFILTER_XT_MATCH_TCPMSS) += xt_tcpmss.o
- obj-$(CONFIG_NETFILTER_XT_MATCH_TIME) += xt_time.o
- obj-$(CONFIG_NETFILTER_XT_MATCH_U32) += xt_u32.o
-+obj-$(CONFIG_NETFILTER_XT_MATCH_PORTSCAN) += xt_portscan.o
---- /dev/null
-+++ b/net/netfilter/xt_CHAOS.c
-@@ -0,0 +1,200 @@
-+/*
-+ * CHAOS target for netfilter
-+ * 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 <linux/icmp.h>
-+#include <linux/in.h>
-+#include <linux/ip.h>
-+#include <linux/module.h>
-+#include <linux/skbuff.h>
-+#include <linux/stat.h>
-+#include <linux/netfilter/x_tables.h>
-+#include <linux/netfilter/xt_tcpudp.h>
-+#include <linux/netfilter_ipv4/ipt_REJECT.h>
-+#include <net/ip.h>
-+#if defined(_LOCAL)
-+# include "xt_CHAOS.h"
-+# include "find_match.c"
-+#elif defined(CONFIG_NETFILTER_XT_TARGET_CHAOS) || \
-+ defined(CONFIG_NETFILTER_XT_TARGET_CHAOS_MODULE)
-+# include <linux/netfilter/xt_CHAOS.h>
-+# include "find_match.c"
-+#else
-+# include "xt_CHAOS.h"
-+# include "find_match.c"
-+#endif
-+#define PFX KBUILD_MODNAME ": "
-+
-+/* Module parameters */
-+static unsigned int reject_percentage = ~0U * .01;
-+static unsigned int delude_percentage = ~0U * .0101;
-+module_param(reject_percentage, uint, S_IRUGO | S_IWUSR);
-+module_param(delude_percentage, uint, S_IRUGO | S_IWUSR);
-+
-+/* References to other matches/targets */
-+static struct xt_match *xm_tcp;
-+static struct xt_target *xt_delude, *xt_reject, *xt_tarpit;
-+
-+static int have_delude, have_tarpit;
-+
-+/* Static data for other matches/targets */
-+static const struct ipt_reject_info reject_params = {
-+ .with = ICMP_HOST_UNREACH,
-+};
-+
-+static const struct xt_tcp tcp_params = {
-+ .spts = {0, ~0},
-+ .dpts = {0, ~0},
-+};
-+
-+/* CHAOS functions */
-+static void xt_chaos_total(const struct xt_chaos_target_info *info,
-+ struct sk_buff *skb, const struct net_device *in,
-+ const struct net_device *out, unsigned int hooknum)
-+{
-+ const struct iphdr *iph = ip_hdr(skb);
-+ const int protoff = 4 * iph->ihl;
-+ const int offset = ntohs(iph->frag_off) & IP_OFFSET;
-+ const struct xt_target *destiny;
-+ bool hotdrop = false, ret;
-+
-+ ret = xm_tcp->match(skb, in, out, xm_tcp, &tcp_params,
-+ offset, protoff, &hotdrop);
-+ if (!ret || hotdrop || (unsigned int)net_random() > delude_percentage)
-+ return;
-+
-+ destiny = (info->variant == XTCHAOS_TARPIT) ? xt_tarpit : xt_delude;
-+ destiny->target(skb, in, out, hooknum, destiny, NULL);
-+ return;
-+}
-+
-+static unsigned int chaos_tg(struct sk_buff *skb,
-+ const struct net_device *in, const struct net_device *out,
-+ unsigned int hooknum, const struct xt_target *target, const void *targinfo)
-+{
-+ /*
-+ * Equivalent to:
-+ * -A chaos -m statistic --mode random --probability \
-+ * $reject_percentage -j REJECT --reject-with host-unreach;
-+ * -A chaos -p tcp -m statistic --mode random --probability \
-+ * $delude_percentage -j DELUDE;
-+ * -A chaos -j DROP;
-+ */
-+ const struct xt_chaos_target_info *info = targinfo;
-+ const struct iphdr *iph = ip_hdr(skb);
-+
-+ if ((unsigned int)net_random() <= reject_percentage)
-+ return xt_reject->target(skb, in, out, hooknum, target,
-+ &reject_params);
-+
-+ /* TARPIT/DELUDE may not be called from the OUTPUT chain */
-+ if (iph->protocol == IPPROTO_TCP &&
-+ info->variant != XTCHAOS_NORMAL && hooknum != NF_INET_LOCAL_OUT)
-+ xt_chaos_total(info, skb, in, out, hooknum);
-+
-+ return NF_DROP;
-+}
-+
-+static bool chaos_tg_check(const char *tablename, const void *entry,
-+ const struct xt_target *target, void *targinfo, unsigned int hook_mask)
-+{
-+ const struct xt_chaos_target_info *info = targinfo;
-+
-+ if (info->variant == XTCHAOS_DELUDE && !have_delude) {
-+ printk(KERN_WARNING PFX "Error: Cannot use --delude when "
-+ "DELUDE module not available\n");
-+ return false;
-+ }
-+ if (info->variant == XTCHAOS_TARPIT && !have_tarpit) {
-+ printk(KERN_WARNING PFX "Error: Cannot use --tarpit when "
-+ "TARPIT module not available\n");
-+ return false;
-+ }
-+
-+ return true;
-+}
-+
-+static struct xt_target chaos_tg_reg = {
-+ .name = "CHAOS",
-+ .family = AF_INET,
-+ .table = "filter",
-+ .hooks = (1 << NF_INET_LOCAL_IN) | (1 << NF_INET_FORWARD) |
-+ (1 << NF_INET_LOCAL_OUT),
-+ .checkentry = chaos_tg_check,
-+ .target = chaos_tg,
-+ .targetsize = sizeof(struct xt_chaos_target_info),
-+ .me = THIS_MODULE,
-+};
-+
-+static int __init chaos_tg_init(void)
-+{
-+ int ret = -EINVAL;
-+
-+ xm_tcp = xt_request_find_match(AF_INET, "tcp", 0);
-+ if (xm_tcp == NULL) {
-+ printk(KERN_WARNING PFX "Error: Could not find or load "
-+ "\"tcp\" match\n");
-+ return -EINVAL;
-+ }
-+
-+ xt_reject = xt_request_find_target(AF_INET, "REJECT", 0);
-+ if (xt_reject == NULL) {
-+ printk(KERN_WARNING PFX "Error: Could not find or load "
-+ "\"REJECT\" target\n");
-+ goto out2;
-+ }
-+
-+ xt_tarpit = xt_request_find_target(AF_INET, "TARPIT", 0);
-+ have_tarpit = xt_tarpit != NULL;
-+ if (!have_tarpit)
-+ printk(KERN_WARNING PFX "Warning: Could not find or load "
-+ "\"TARPIT\" target\n");
-+
-+ xt_delude = xt_request_find_target(AF_INET, "DELUDE", 0);
-+ have_delude = xt_delude != NULL;
-+ if (!have_delude)
-+ printk(KERN_WARNING PFX "Warning: Could not find or load "
-+ "\"DELUDE\" target\n");
-+
-+ if ((ret = xt_register_target(&chaos_tg_reg)) != 0) {
-+ printk(KERN_WARNING PFX "xt_register_target returned "
-+ "error %d\n", ret);
-+ goto out3;
-+ }
-+
-+ return 0;
-+
-+ out3:
-+ if (have_delude)
-+ module_put(xt_delude->me);
-+ if (have_tarpit)
-+ module_put(xt_tarpit->me);
-+ module_put(xt_reject->me);
-+ out2:
-+ module_put(xm_tcp->me);
-+ return ret;
-+}
-+
-+static void __exit chaos_tg_exit(void)
-+{
-+ xt_unregister_target(&chaos_tg_reg);
-+ module_put(xm_tcp->me);
-+ module_put(xt_reject->me);
-+ if (have_delude)
-+ module_put(xt_delude->me);
-+ if (have_tarpit)
-+ module_put(xt_tarpit->me);
-+ return;
-+}
-+
-+module_init(chaos_tg_init);
-+module_exit(chaos_tg_exit);
-+MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
-+MODULE_DESCRIPTION("netfilter \"CHAOS\" target");
-+MODULE_LICENSE("GPL");
-+MODULE_ALIAS("ipt_CHAOS");
---- /dev/null
-+++ b/net/netfilter/xt_DELUDE.c
-@@ -0,0 +1,197 @@
-+/*
-+ * DELUDE target
-+ * Copyright © CC Computer Consultants GmbH, 2007
-+ * Contact: Jan Engelhardt <jengelh@computergmbh.de>
-+ *
-+ * Based upon linux-2.6.18.5/net/ipv4/netfilter/ipt_REJECT.c:
-+ * (C) 1999-2001 Paul `Rusty' Russell
-+ * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
-+ *
-+ * xt_DELUDE acts like REJECT, but does reply with SYN-ACK on SYN.
-+ *
-+ * This program is free software; you can redistribute it and/or modify
-+ * it under the terms of the GNU General Public License version 2 as
-+ * published by the Free Software Foundation.
-+ */
-+#include <linux/module.h>
-+#include <linux/skbuff.h>
-+#include <linux/ip.h>
-+#include <linux/tcp.h>
-+#include <linux/netfilter/x_tables.h>
-+#ifdef CONFIG_BRIDGE_NETFILTER
-+# include <linux/netfilter_bridge.h>
-+#endif
-+#include <net/tcp.h>
-+#define PFX KBUILD_MODNAME ": "
-+
-+static void delude_send_reset(struct sk_buff *oldskb, unsigned int hook)
-+{
-+ struct tcphdr _otcph, *oth, *tcph;
-+ unsigned int addr_type;
-+ struct sk_buff *nskb;
-+ u_int16_t tmp_port;
-+ u_int32_t tmp_addr;
-+ struct iphdr *niph;
-+ bool needs_ack;
-+
-+ /* IP header checks: fragment. */
-+ if (ip_hdr(oldskb)->frag_off & htons(IP_OFFSET))
-+ return;
-+
-+ oth = skb_header_pointer(oldskb, ip_hdrlen(oldskb),
-+ sizeof(_otcph), &_otcph);
-+ if (oth == NULL)
-+ return;
-+
-+ /* No RST for RST. */
-+ if (oth->rst)
-+ return;
-+
-+ /* Check checksum */
-+ if (nf_ip_checksum(oldskb, hook, ip_hdrlen(oldskb), IPPROTO_TCP))
-+ return;
-+
-+ /* We need a linear, writeable skb. We also need to expand
-+ headroom in case hh_len of incoming interface < hh_len of
-+ outgoing interface */
-+ nskb = skb_copy_expand(oldskb, LL_MAX_HEADER, skb_tailroom(oldskb),
-+ GFP_ATOMIC);
-+ if (!nskb)
-+ return;
-+
-+ /* This packet will not be the same as the other: clear nf fields */
-+ nf_reset(nskb);
-+ nskb->mark = 0;
-+ skb_init_secmark(nskb);
-+
-+ skb_shinfo(nskb)->gso_size = 0;
-+ skb_shinfo(nskb)->gso_segs = 0;
-+ skb_shinfo(nskb)->gso_type = 0;
-+
-+ tcph = (struct tcphdr *)(skb_network_header(nskb) + ip_hdrlen(nskb));
-+
-+ /* Swap source and dest */
-+ niph = ip_hdr(nskb);
-+ tmp_addr = niph->saddr;
-+ niph->saddr = niph->daddr;
-+ niph->daddr = tmp_addr;
-+ tmp_port = tcph->source;
-+ tcph->source = tcph->dest;
-+ tcph->dest = tmp_port;
-+
-+ /* Truncate to length (no data) */
-+ tcph->doff = sizeof(struct tcphdr) / 4;
-+ skb_trim(nskb, ip_hdrlen(nskb) + sizeof(struct tcphdr));
-+ niph->tot_len = htons(nskb->len);
-+
-+ if (oth->syn && !oth->ack && !oth->rst && !oth->fin) {
-+ /* DELUDE essential part */
-+ tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn + oth->fin +
-+ oldskb->len - ip_hdrlen(oldskb) -
-+ (oth->doff << 2));
-+ tcph->seq = false;
-+ tcph->ack = true;
-+ } else {
-+ if (!tcph->ack) {
-+ needs_ack = true;
-+ tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn +
-+ oth->fin + oldskb->len -
-+ ip_hdrlen(oldskb) - (oth->doff<<2));
-+ tcph->seq = false;
-+ } else {
-+ needs_ack = false;
-+ tcph->seq = oth->ack_seq;
-+ tcph->ack_seq = false;
-+ }
-+
-+ /* Reset flags */
-+ ((u_int8_t *)tcph)[13] = 0;
-+ tcph->rst = true;
-+ tcph->ack = needs_ack;
-+ }
-+
-+ tcph->window = 0;
-+ tcph->urg_ptr = 0;
-+
-+ /* Adjust TCP checksum */
-+ tcph->check = 0;
-+ tcph->check = tcp_v4_check(sizeof(struct tcphdr), niph->saddr,
-+ niph->daddr, csum_partial((char *)tcph,
-+ sizeof(struct tcphdr), 0));
-+
-+ /* Set DF, id = 0 */
-+ niph->frag_off = htons(IP_DF);
-+ niph->id = 0;
-+
-+ addr_type = RTN_UNSPEC;
-+#ifdef CONFIG_BRIDGE_NETFILTER
-+ if (hook != NF_INET_FORWARD || (nskb->nf_bridge != NULL &&
-+ nskb->nf_bridge->mask & BRNF_BRIDGED))
-+#else
-+ if (hook != NF_INET_FORWARD)
-+#endif
-+ addr_type = RTN_LOCAL;
-+
-+ if (ip_route_me_harder(nskb, addr_type))
-+ goto free_nskb;
-+
-+ nskb->ip_summed = CHECKSUM_NONE;
-+
-+ /* Adjust IP TTL */
-+ niph->ttl = dst_metric(nskb->dst, RTAX_HOPLIMIT);
-+
-+ /* Adjust IP checksum */
-+ niph->check = 0;
-+ niph->check = ip_fast_csum(skb_network_header(nskb), niph->ihl);
-+
-+ /* "Never happens" */
-+ if (nskb->len > dst_mtu(nskb->dst))
-+ goto free_nskb;
-+
-+ nf_ct_attach(nskb, oldskb);
-+
-+ NF_HOOK(PF_INET, NF_INET_LOCAL_OUT, nskb, NULL, nskb->dst->dev,
-+ dst_output);
-+ return;
-+
-+ free_nskb:
-+ kfree_skb(nskb);
-+}
-+
-+static unsigned int delude_tg(struct sk_buff *skb,
-+ const struct net_device *in, const struct net_device *out,
-+ unsigned int hooknum, const struct xt_target *target, const void *targinfo)
-+{
-+ /* WARNING: This code causes reentry within iptables.
-+ This means that the iptables jump stack is now crap. We
-+ must return an absolute verdict. --RR */
-+ delude_send_reset(skb, hooknum);
-+ return NF_DROP;
-+}
-+
-+static struct xt_target delude_tg_reg = {
-+ .name = "DELUDE",
-+ .family = AF_INET,
-+ .table = "filter",
-+ .hooks = (1 << NF_INET_LOCAL_IN) | (1 << NF_INET_FORWARD),
-+ .target = delude_tg,
-+ .proto = IPPROTO_TCP,
-+ .me = THIS_MODULE,
-+};
-+
-+static int __init delude_tg_init(void)
-+{
-+ return xt_register_target(&delude_tg_reg);
-+}
-+
-+static void __exit delude_tg_exit(void)
-+{
-+ xt_unregister_target(&delude_tg_reg);
-+}
-+
-+module_init(delude_tg_init);
-+module_exit(delude_tg_exit);
-+MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
-+MODULE_DESCRIPTION("netfilter \"DELUDE\" target");
-+MODULE_LICENSE("GPL");
-+MODULE_ALIAS("ipt_DELUDE");
---- /dev/null
-+++ b/net/netfilter/xt_portscan.c
-@@ -0,0 +1,269 @@
-+/*
-+ * portscan match for netfilter
-+ * 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 <linux/in.h>
-+#include <linux/ip.h>
-+#include <linux/module.h>
-+#include <linux/moduleparam.h>
-+#include <linux/skbuff.h>
-+#include <linux/stat.h>
-+#include <linux/tcp.h>
-+#include <linux/types.h>
-+#include <linux/version.h>
-+#include <linux/netfilter/x_tables.h>
-+#include <linux/netfilter/xt_tcpudp.h>
-+#include <net/netfilter/nf_nat_rule.h>
-+#if defined(_LOCAL)
-+# include "xt_portscan.h"
-+#elif defined(CONFIG_NETFILTER_XT_MATCH_PORTSCAN) || \
-+ defined(CONFIG_NETFILTER_XT_MATCH_PORTSCAN_MODULE)
-+# include <linux/netfilter/xt_portscan.h>
-+#else
-+# include "xt_portscan.h"
-+#endif
-+#define PFX KBUILD_MODNAME ": "
-+
-+enum {
-+ TCP_FLAGS_ALL3 = TCP_FLAG_FIN | TCP_FLAG_RST | TCP_FLAG_SYN,
-+ TCP_FLAGS_ALL4 = TCP_FLAGS_ALL3 | TCP_FLAG_ACK,
-+ TCP_FLAGS_ALL6 = TCP_FLAGS_ALL4 | TCP_FLAG_PSH | TCP_FLAG_URG,
-+};
-+
-+/* Module parameters */
-+static unsigned int
-+ connmark_mask = ~0,
-+ packet_mask = ~0,
-+ mark_seen = 0x9,
-+ mark_synrcv = 0x1,
-+ mark_closed = 0x2,
-+ mark_synscan = 0x3,
-+ mark_estab1 = 0x4,
-+ mark_estab2 = 0x5,
-+ mark_cnscan = 0x6,
-+ mark_grscan = 0x7,
-+ mark_valid = 0x8;
-+
-+module_param(connmark_mask, uint, S_IRUGO | S_IWUSR);
-+module_param(packet_mask, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_seen, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_synrcv, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_closed, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_synscan, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_estab1, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_estab2, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_cnscan, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_grscan, uint, S_IRUGO | S_IWUSR);
-+module_param(mark_valid, uint, S_IRUGO | S_IWUSR);
-+MODULE_PARM_DESC(connmark_mask, "only set specified bits in connection mark");
-+MODULE_PARM_DESC(packet_mask, "only set specified bits in packet mark");
-+MODULE_PARM_DESC(mark_seen, "nfmark value for packet-seen state");
-+MODULE_PARM_DESC(mark_synrcv, "connmark value for SYN Received state");
-+MODULE_PARM_DESC(mark_closed, "connmark value for closed state");
-+MODULE_PARM_DESC(mark_synscan, "connmark value for SYN Scan state");
-+MODULE_PARM_DESC(mark_estab1, "connmark value for Established-1 state");
-+MODULE_PARM_DESC(mark_estab2, "connmark value for Established-2 state");
-+MODULE_PARM_DESC(mark_cnscan, "connmark value for Connect Scan state");
-+MODULE_PARM_DESC(mark_grscan, "connmark value for Grab Scan state");
-+MODULE_PARM_DESC(mark_valid, "connmark value for Valid state");
-+
-+/* TCP flag functions */
-+static inline bool tflg_ack4(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL4) == TCP_FLAG_ACK;
-+}
-+
-+static inline bool tflg_ack6(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL6) == TCP_FLAG_ACK;
-+}
-+
-+static inline bool tflg_fin(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL3) == TCP_FLAG_FIN;
-+}
-+
-+static inline bool tflg_rst(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL3) == TCP_FLAG_RST;
-+}
-+
-+static inline bool tflg_rstack(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL4) ==
-+ (TCP_FLAG_ACK | TCP_FLAG_RST);
-+}
-+
-+static inline bool tflg_syn(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL4) == TCP_FLAG_SYN;
-+}
-+
-+static inline bool tflg_synack(const struct tcphdr *th)
-+{
-+ return (tcp_flag_word(th) & TCP_FLAGS_ALL4) ==
-+ (TCP_FLAG_SYN | TCP_FLAG_ACK);
-+}
-+
-+/* portscan functions */
-+static inline bool portscan_mt_stealth(const struct tcphdr *th)
-+{
-+ /*
-+ * "Connection refused" replies to our own probes must not be matched.
-+ */
-+ if (tflg_rstack(th))
-+ return false;
-+
-+ if (tflg_rst(th) && printk_ratelimit()) {
-+ printk(KERN_WARNING PFX "Warning: Pure RST received\n");
-+ return false;
-+ }
-+
-+ /*
-+ * -p tcp ! --syn -m conntrack --ctstate INVALID: Looking for non-start
-+ * packets that are not associated with any connection -- this will
-+ * match most scan types (NULL, XMAS, FIN) and ridiculous flag
-+ * combinations (SYN-RST, SYN-FIN, SYN-FIN-RST, FIN-RST, etc.).
-+ */
-+ return !tflg_syn(th);
-+}
-+
-+static inline unsigned int portscan_mt_full(int mark,
-+ enum ip_conntrack_info ctstate, bool loopback, const struct tcphdr *tcph,
-+ unsigned int payload_len)
-+{
-+ if (mark == mark_estab2) {
-+ /*
-+ * -m connmark --mark $ESTAB2
-+ */
-+ if (tflg_ack4(tcph) && payload_len == 0)
-+ return mark; /* keep mark */
-+ else if (tflg_rst(tcph) || tflg_fin(tcph))
-+ return mark_grscan;
-+ else
-+ return mark_valid;
-+ } else if (mark == mark_estab1) {
-+ /*
-+ * -m connmark --mark $ESTAB1
-+ */
-+ if (tflg_rst(tcph) || tflg_fin(tcph))
-+ return mark_cnscan;
-+ else if (!loopback && tflg_ack4(tcph) && payload_len == 0)
-+ return mark_estab2;
-+ else
-+ return mark_valid;
-+ } else if (mark == mark_synrcv) {
-+ /*
-+ * -m connmark --mark $SYN
-+ */
-+ if (loopback && tflg_synack(tcph))
-+ return mark; /* keep mark */
-+ else if (loopback && tflg_rstack(tcph))
-+ return mark_closed;
-+ else if (tflg_ack6(tcph))
-+ return mark_estab1;
-+ else
-+ return mark_synscan;
-+ } else if (ctstate == IP_CT_NEW && tflg_syn(tcph)) {
-+ /*
-+ * -p tcp --syn --ctstate NEW
-+ */
-+ return mark_synrcv;
-+ }
-+ return mark;
-+}
-+
-+static bool portscan_mt(const struct sk_buff *skb,
-+ const struct net_device *in, const struct net_device *out,
-+ const struct xt_match *match, const void *matchinfo, int offset,
-+ unsigned int protoff, bool *hotdrop)
-+{
-+ const struct xt_portscan_match_info *info = matchinfo;
-+ enum ip_conntrack_info ctstate;
-+ const struct tcphdr *tcph;
-+ struct nf_conn *ctdata;
-+ struct tcphdr tcph_buf;
-+
-+ tcph = skb_header_pointer(skb, protoff, sizeof(tcph_buf), &tcph_buf);
-+ if (tcph == NULL)
-+ return false;
-+
-+ /* Check for invalid packets: -m conntrack --ctstate INVALID */
-+ if ((ctdata = nf_ct_get(skb, &ctstate)) == NULL) {
-+ if (info->match_stealth)
-+ return portscan_mt_stealth(tcph);
-+ /*
-+ * If @ctdata is NULL, we cannot match the other scan
-+ * types, return.
-+ */
-+ return false;
-+ }
-+
-+ /*
-+ * If -m portscan was previously applied to this packet, the rules we
-+ * simulate must not be run through again. And for speedup, do not call
-+ * it either when the connection is already VALID.
-+ */
-+ if ((ctdata->mark & connmark_mask) == mark_valid ||
-+ (skb->mark & packet_mask) != mark_seen) {
-+ unsigned int n;
-+
-+ n = portscan_mt_full(ctdata->mark & connmark_mask, ctstate,
-+ (in->flags & IFF_LOOPBACK) == IFF_LOOPBACK, tcph,
-+ skb->len - protoff - 4 * tcph->doff);
-+
-+ ctdata->mark = (ctdata->mark & ~connmark_mask) | n;
-+ ((struct sk_buff *)skb)->mark =
-+ (skb->mark & ~packet_mask) ^ mark_seen;
-+ }
-+
-+ return (info->match_syn && ctdata->mark == mark_synscan) ||
-+ (info->match_cn && ctdata->mark == mark_cnscan) ||
-+ (info->match_gr && ctdata->mark == mark_grscan);
-+}
-+
-+static bool portscan_mt_check(const char *tablename, const void *entry,
-+ const struct xt_match *match, void *matchinfo, unsigned int hook_mask)
-+{
-+ const struct xt_portscan_match_info *info = matchinfo;
-+
-+ if ((info->match_stealth & ~1) || (info->match_syn & ~1) ||
-+ (info->match_cn & ~1) || (info->match_gr & ~1)) {
-+ printk(KERN_WARNING PFX "Invalid flags\n");
-+ return false;
-+ }
-+ return true;
-+}
-+
-+static struct xt_match portscan_mt_reg __read_mostly = {
-+ .name = "portscan",
-+ .family = AF_INET,
-+ .match = portscan_mt,
-+ .checkentry = portscan_mt_check,
-+ .matchsize = sizeof(struct xt_portscan_match_info),
-+ .proto = IPPROTO_TCP,
-+ .me = THIS_MODULE,
-+};
-+
-+static int __init portscan_mt_init(void)
-+{
-+ return xt_register_match(&portscan_mt_reg);
-+}
-+
-+static void __exit portscan_mt_exit(void)
-+{
-+ xt_unregister_match(&portscan_mt_reg);
-+ return;
-+}
-+
-+module_init(portscan_mt_init);
-+module_exit(portscan_mt_exit);
-+MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>");
-+MODULE_DESCRIPTION("netfilter \"portscan\" match");
-+MODULE_LICENSE("GPL");
-+MODULE_ALIAS("ipt_portscan");
---- a/drivers/char/random.c
-+++ b/drivers/char/random.c
-@@ -1555,6 +1555,8 @@ __u32 secure_tcp_sequence_number(__be32
- return seq;
- }
-
-+EXPORT_SYMBOL(secure_tcp_sequence_number);
-+
- /* Generate secure starting point for ephemeral IPV4 transport port search */
- u32 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport)
- {
+++ /dev/null
---- a/net/netfilter/Kconfig
-+++ b/net/netfilter/Kconfig
-@@ -457,6 +457,23 @@ config NETFILTER_XT_TARGET_CONNSECMARK
-
- To compile it as a module, choose M here. If unsure, say N.
-
-+config NETFILTER_XT_TARGET_TARPIT
-+ tristate '"TARPIT" target support'
-+ depends on NETFILTER_XTABLES
-+ ---help---
-+ Adds a TARPIT target to iptables, which 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 does not require dedicated
-+ hardware or IPs. Any TCP port that you would normally DROP or REJECT
-+ can instead become a tarpit.
-+
- config NETFILTER_XT_TARGET_TCPMSS
- tristate '"TCPMSS" target support'
- depends on NETFILTER_XTABLES && (IPV6 || IPV6=n)
---- a/net/netfilter/Makefile
-+++ b/net/netfilter/Makefile
-@@ -48,6 +48,7 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_NFQUEUE
- obj-$(CONFIG_NETFILTER_XT_TARGET_NOTRACK) += xt_NOTRACK.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_RATEEST) += xt_RATEEST.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_SECMARK) += xt_SECMARK.o
-+obj-$(CONFIG_NETFILTER_XT_TARGET_TARPIT) += xt_TARPIT.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_TCPMSS) += xt_TCPMSS.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_TCPOPTSTRIP) += xt_TCPOPTSTRIP.o
- obj-$(CONFIG_NETFILTER_XT_TARGET_TRACE) += xt_TRACE.o
---- /dev/null
-+++ b/net/netfilter/xt_TARPIT.c
-@@ -0,0 +1,279 @@
-+/*
-+ * Kernel module to capture and hold incoming TCP connections using
-+ * no local per-connection resources.
-+ *
-+ * Based on ipt_REJECT.c and offering functionality similar to
-+ * LaBrea <http://www.hackbusters.net/LaBrea/>.
-+ *
-+ * Copyright (c) 2002 Aaron Hopkins <tools@die.net>
-+ *
-+ * This program is free software; you can redistribute it and/or modify
-+ * it under the terms of the GNU General Public License as published by
-+ * the Free Software Foundation; either version 2 of the License, or
-+ * (at your option) any later version.
-+ *
-+ * This program is distributed in the hope that it will be useful,
-+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
-+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-+ * GNU General Public License for more details.
-+ *
-+ * You should have received a copy of the GNU General Public License
-+ * along with this program; if not, write to the Free Software
-+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-+ *
-+ * Goal:
-+ * - Allow incoming TCP connections to be established.
-+ * - Passing data should result in the connection being switched to the
-+ * persist state (0 byte window), in which the remote side stops sending
-+ * data and asks to continue every 60 seconds.
-+ * - Attempts to shut down the connection should be ignored completely, so
-+ * the remote side ends up having to time it out.
-+ *
-+ * This means:
-+ * - Reply to TCP SYN,!ACK,!RST,!FIN with SYN-ACK, window 5 bytes
-+ * - Reply to TCP SYN,ACK,!RST,!FIN with RST to prevent spoofing
-+ * - Reply to TCP !SYN,!RST,!FIN with ACK, window 0 bytes, rate-limited
-+ */
-+
-+#include <linux/version.h>
-+#include <linux/module.h>
-+#include <linux/skbuff.h>
-+#include <linux/ip.h>
-+#include <net/ip.h>
-+#include <net/tcp.h>
-+#include <net/icmp.h>
-+struct in_device;
-+#include <net/route.h>
-+#include <linux/random.h>
-+#include <linux/netfilter_ipv4/ip_tables.h>
-+
-+#if 0
-+#define DEBUGP printk
-+#else
-+#define DEBUGP(format, args...)
-+#endif
-+
-+/* Stolen from ip_finish_output2 */
-+static int ip_direct_send(struct sk_buff *skb)
-+{
-+ struct dst_entry *dst = skb->dst;
-+
-+ if (dst->hh != NULL)
-+ return neigh_hh_output(dst->hh, skb);
-+ else if (dst->neighbour != NULL)
-+ return dst->neighbour->output(skb);
-+
-+ if (net_ratelimit())
-+ printk(KERN_DEBUG "TARPIT ip_direct_send: no header cache and no neighbor!\n");
-+
-+ kfree_skb(skb);
-+ return -EINVAL;
-+}
-+
-+
-+/* Send reply */
-+static void tarpit_tcp(const struct sk_buff *oskb, struct rtable *ort,
-+ unsigned int local)
-+{
-+ struct sk_buff *nskb;
-+ struct rtable *nrt;
-+ struct tcphdr *otcph, *ntcph;
-+ struct flowi fl = {};
-+ unsigned int otcplen;
-+ u_int16_t tmp;
-+
-+ const struct iphdr *oiph = ip_hdr(oskb);
-+ struct iphdr *niph;
-+
-+ /* A truncated TCP header is not going to be useful */
-+ if (oskb->len < ip_hdrlen(oskb) + sizeof(struct tcphdr))
-+ return;
-+
-+ otcph = (void *)oiph + ip_hdrlen(oskb);
-+ otcplen = oskb->len - ip_hdrlen(oskb);
-+
-+ /* No replies for RST or FIN */
-+ if (otcph->rst || otcph->fin)
-+ return;
-+
-+ /* No reply to !SYN,!ACK. Rate-limit replies to !SYN,ACKs */
-+ if (!otcph->syn && (!otcph->ack || !xrlim_allow(&ort->u.dst, 1*HZ)))
-+ return;
-+
-+ /* Check checksum. */
-+ if (tcp_v4_check(otcplen, oiph->saddr, oiph->daddr,
-+ csum_partial((char *)otcph, otcplen, 0)) != 0)
-+ return;
-+
-+ /*
-+ * Copy skb (even if skb is about to be dropped, we cannot just
-+ * clone it because there may be other things, such as tcpdump,
-+ * interested in it)
-+ */
-+ nskb = skb_copy(oskb, GFP_ATOMIC);
-+ if (nskb == NULL)
-+ return;
-+
-+ niph = ip_hdr(nskb);
-+
-+ /* This packet will not be the same as the other: clear nf fields */
-+ nf_conntrack_put(nskb->nfct);
-+ nskb->nfct = NULL;
-+#ifdef CONFIG_NETFILTER_DEBUG
-+ nskb->nf_debug = 0;
-+#endif
-+
-+ ntcph = (void *)niph + ip_hdrlen(nskb);
-+
-+ /* Truncate to length (no data) */
-+ ntcph->doff = sizeof(struct tcphdr)/4;
-+ skb_trim(nskb, ip_hdrlen(nskb) + sizeof(struct tcphdr));
-+ niph->tot_len = htons(nskb->len);
-+
-+ /* Swap source and dest */
-+ niph->daddr = xchg(&niph->saddr, niph->daddr);
-+ tmp = ntcph->source;
-+ ntcph->source = ntcph->dest;
-+ ntcph->dest = tmp;
-+
-+ /* Use supplied sequence number or make a new one */
-+ ntcph->seq = otcph->ack ? otcph->ack_seq
-+ : htonl(secure_tcp_sequence_number(niph->saddr,
-+ niph->daddr,
-+ ntcph->source,
-+ ntcph->dest));
-+
-+ /* Our SYN-ACKs must have a >0 window */
-+ ntcph->window = (otcph->syn && !otcph->ack) ? htons(5) : 0;
-+
-+ ntcph->urg_ptr = 0;
-+
-+ /* Reset flags */
-+ ((u_int8_t *)ntcph)[13] = 0;
-+
-+ if (otcph->syn && otcph->ack) {
-+ ntcph->rst = 1;
-+ ntcph->ack_seq = 0;
-+ } else {
-+ ntcph->syn = otcph->syn;
-+ ntcph->ack = 1;
-+ ntcph->ack_seq = htonl(ntohl(otcph->seq) + otcph->syn);
-+ }
-+
-+ /* Adjust TCP checksum */
-+ ntcph->check = 0;
-+ ntcph->check = tcp_v4_check(sizeof(struct tcphdr),
-+ niph->saddr,
-+ niph->daddr,
-+ csum_partial((char *)ntcph,
-+ sizeof(struct tcphdr), 0));
-+
-+ fl.nl_u.ip4_u.daddr = niph->daddr;
-+ fl.nl_u.ip4_u.saddr = local ? niph->saddr : 0;
-+ fl.nl_u.ip4_u.tos = RT_TOS(niph->tos) | RTO_CONN;
-+ fl.oif = 0;
-+
-+ if (ip_route_output_key(&init_net, &nrt, &fl))
-+ goto free_nskb;
-+
-+ dst_release(nskb->dst);
-+ nskb->dst = &nrt->u.dst;
-+
-+ /* Adjust IP TTL */
-+ niph->ttl = dst_metric(nskb->dst, RTAX_HOPLIMIT);
-+
-+ /* Set DF, id = 0 */
-+ niph->frag_off = htons(IP_DF);
-+ niph->id = 0;
-+
-+ /* Adjust IP checksum */
-+ niph->check = 0;
-+ niph->check = ip_fast_csum((unsigned char *)niph, niph->ihl);
-+
-+ /* "Never happens" */
-+ if (nskb->len > dst_mtu(nskb->dst))
-+ goto free_nskb;
-+
-+ ip_direct_send(nskb);
-+ return;
-+
-+ free_nskb:
-+ kfree_skb(nskb);
-+}
-+
-+static unsigned int xt_tarpit_target(struct sk_buff *skb,
-+ const struct net_device *in,
-+ const struct net_device *out,
-+ unsigned int hooknum,
-+ const struct xt_target *target,
-+ const void *targinfo)
-+{
-+ const struct iphdr *iph = ip_hdr(skb);
-+ struct rtable *rt = (void *)skb->dst;
-+
-+ /* Do we have an input route cache entry? */
-+ if (rt == NULL)
-+ return NF_DROP;
-+
-+ /* No replies to physical multicast/broadcast */
-+ if (skb->pkt_type != PACKET_HOST && skb->pkt_type != PACKET_OTHERHOST)
-+ return NF_DROP;
-+
-+ /* Now check at the protocol level */
-+ if (rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST))
-+ return NF_DROP;
-+
-+ /*
-+ * Our naive response construction does not deal with IP
-+ * options, and probably should not try.
-+ */
-+ if (iph->ihl * 4 != sizeof(struct iphdr))
-+ return NF_DROP;
-+
-+ /* We are not interested in fragments */
-+ if (iph->frag_off & htons(IP_OFFSET))
-+ return NF_DROP;
-+
-+ tarpit_tcp(skb, rt, hooknum == NF_INET_LOCAL_IN);
-+ return NF_DROP;
-+}
-+
-+static bool xt_tarpit_check(const char *tablename, const void *entry,
-+ const struct xt_target *target, void *targinfo,
-+ unsigned int hook_mask)
-+{
-+ bool invalid;
-+
-+ if (strcmp(tablename, "raw") == 0 && hook_mask == NF_INET_PRE_ROUTING)
-+ return true;
-+ if (strcmp(tablename, "filter") != 0)
-+ return false;
-+ invalid = hook_mask & ~((1 << NF_INET_LOCAL_IN) | (1 << NF_INET_FORWARD));
-+ return !invalid;
-+}
-+
-+static struct xt_target xt_tarpit_reg = {
-+ .name = "TARPIT",
-+ .family = AF_INET,
-+ .proto = IPPROTO_TCP,
-+ .target = xt_tarpit_target,
-+ .checkentry = xt_tarpit_check,
-+ .me = THIS_MODULE,
-+};
-+
-+static int __init xt_tarpit_init(void)
-+{
-+ return xt_register_target(&xt_tarpit_reg);
-+}
-+
-+static void __exit xt_tarpit_exit(void)
-+{
-+ xt_unregister_target(&xt_tarpit_reg);
-+}
-+
-+module_init(xt_tarpit_init);
-+module_exit(xt_tarpit_exit);
-+MODULE_DESCRIPTION("netfilter xt_TARPIT target module");
-+MODULE_AUTHOR("Jan Engelhardt <jengelh@gmx.de>");
-+MODULE_LICENSE("GPL");
-+MODULE_ALIAS("ipt_TARPIT");
depends on NETFILTER_ADVANCED
help
H.323 is a VoIP signalling protocol from ITU-T. As one of the most
-@@ -476,7 +476,7 @@ config NETFILTER_XT_TARGET_TARPIT
+@@ -443,7 +443,7 @@ config NETFILTER_XT_TARGET_CONNSECMARK
config NETFILTER_XT_TARGET_TCPMSS
tristate '"TCPMSS" target support'
projects / openwrt / svn-archive / archive.git / commitdiff