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Name	Size	Permission
ACCOUNT	[ DIR ]	drwxr-xr-x
pknock	[ DIR ]	drwxr-xr-x
Kbuild	1020 B	-rw-r--r--
Makefile	14.31 KB	-rw-r--r--
Makefile.am	910 B	-rw-r--r--
Makefile.in	13.55 KB	-rw-r--r--
Mbuild	989 B	-rw-r--r--
compat_skbuff.h	325 B	-rw-r--r--
compat_user.h	262 B	-rw-r--r--
compat_xtables.c	1.18 KB	-rw-r--r--
compat_xtables.h	2.52 KB	-rw-r--r--
compat_xtnu.h	1.97 KB	-rw-r--r--
libxt_CHAOS.c	2.56 KB	-rw-r--r--
libxt_CHAOS.man	1 KB	-rw-r--r--
libxt_DELUDE.c	1.11 KB	-rw-r--r--
libxt_DELUDE.man	286 B	-rw-r--r--
libxt_DHCPMAC.c	2.55 KB	-rw-r--r--
libxt_DHCPMAC.man	1.2 KB	-rw-r--r--
libxt_DNETMAP.c	6.62 KB	-rw-r--r--
libxt_DNETMAP.man	7.71 KB	-rw-r--r--
libxt_ECHO.c	1.03 KB	-rw-r--r--
libxt_ECHO.man	141 B	-rw-r--r--
libxt_IPMARK.c	4.71 KB	-rw-r--r--
libxt_IPMARK.man	1.99 KB	-rw-r--r--
libxt_LOGMARK.c	3.27 KB	-rw-r--r--
libxt_LOGMARK.man	312 B	-rw-r--r--
libxt_SYSRQ.c	844 B	-rw-r--r--
libxt_SYSRQ.man	3.67 KB	-rw-r--r--
libxt_TARPIT.c	2.75 KB	-rw-r--r--
libxt_TARPIT.man	2.55 KB	-rw-r--r--
libxt_condition.c	2.5 KB	-rw-r--r--
libxt_condition.man	175 B	-rw-r--r--
libxt_dhcpmac.c	2.52 KB	-rw-r--r--
libxt_dhcpmac.man	207 B	-rw-r--r--
libxt_fuzzy.c	3.37 KB	-rw-r--r--
libxt_fuzzy.man	263 B	-rw-r--r--
libxt_geoip.c	8.21 KB	-rw-r--r--
libxt_geoip.man	1 KB	-rw-r--r--
libxt_gradm.c	2.3 KB	-rw-r--r--
libxt_gradm.man	225 B	-rw-r--r--
libxt_iface.c	7.21 KB	-rw-r--r--
libxt_iface.man	1.39 KB	-rw-r--r--
libxt_ipp2p.c	7.36 KB	-rw-r--r--
libxt_ipp2p.man	1.52 KB	-rw-r--r--
libxt_ipv4options.c	4.32 KB	-rw-r--r--
libxt_ipv4options.man	1.44 KB	-rw-r--r--
libxt_length2.c	4.69 KB	-rw-r--r--
libxt_length2.man	695 B	-rw-r--r--
libxt_lscan.c	2.64 KB	-rw-r--r--
libxt_lscan.man	1.58 KB	-rw-r--r--
libxt_psd.c	5.34 KB	-rw-r--r--
libxt_psd.man	720 B	-rw-r--r--
libxt_quota2.c	4.06 KB	-rw-r--r--
libxt_quota2.man	1.6 KB	-rw-r--r--
mac.c	572 B	-rw-r--r--
xt_CHAOS.c	6.29 KB	-rw-r--r--
xt_CHAOS.h	249 B	-rw-r--r--
xt_DELUDE.c	4.96 KB	-rw-r--r--
xt_DHCPMAC.c	4.18 KB	-rw-r--r--
xt_DHCPMAC.h	311 B	-rw-r--r--
xt_DNETMAP.c	25.22 KB	-rw-r--r--
xt_DNETMAP.h	402 B	-rw-r--r--
xt_ECHO.c	6.98 KB	-rw-r--r--
xt_IPMARK.c	2.75 KB	-rw-r--r--
xt_IPMARK.h	252 B	-rw-r--r--
xt_LOGMARK.c	3.96 KB	-rw-r--r--
xt_LOGMARK.h	209 B	-rw-r--r--
xt_SYSRQ.c	9.75 KB	-rw-r--r--
xt_TARPIT.c	14.94 KB	-rw-r--r--
xt_TARPIT.h	258 B	-rw-r--r--
xt_condition.c	6.75 KB	-rw-r--r--
xt_condition.h	276 B	-rw-r--r--
xt_fuzzy.c	4.65 KB	-rw-r--r--
xt_fuzzy.h	397 B	-rw-r--r--
xt_geoip.c	8.73 KB	-rw-r--r--
xt_geoip.h	1.34 KB	-rw-r--r--
xt_gradm.h	108 B	-rw-r--r--
xt_iface.c	3.32 KB	-rw-r--r--
xt_iface.h	596 B	-rw-r--r--
xt_ipp2p.c	23.63 KB	-rw-r--r--
xt_ipp2p.h	995 B	-rw-r--r--
xt_ipv4options.c	1.96 KB	-rw-r--r--
xt_ipv4options.h	581 B	-rw-r--r--
xt_length2.c	6.99 KB	-rw-r--r--
xt_length2.h	457 B	-rw-r--r--
xt_lscan.c	7.85 KB	-rw-r--r--
xt_lscan.h	200 B	-rw-r--r--
xt_psd.c	14.2 KB	-rw-r--r--
xt_psd.h	792 B	-rw-r--r--
xt_quota2.c	9 KB	-rw-r--r--
xt_quota2.h	478 B	-rw-r--r--

Code Editor : xt_DELUDE.c

/*
 *	"DELUDE" target extension for Xtables
 *	Copyright © Jan Engelhardt, 2007 - 2008
 *
 *	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/version.h>
#include <linux/netfilter/x_tables.h>
#ifdef CONFIG_BRIDGE_NETFILTER
#	include <linux/netfilter_bridge.h>
#endif
#include <net/tcp.h>
#include "compat_xtables.h"
#define PFX KBUILD_MODNAME ": "

static void delude_send_reset(struct net *net, struct sk_buff *oldskb,
    unsigned int hook)
{
	struct tcphdr _otcph, *tcph;
	const struct tcphdr *oth;
	const struct iphdr *oiph;
	unsigned int addr_type;
	struct sk_buff *nskb;
	struct iphdr *niph;

oiph = ip_hdr(oldskb);

/* IP header checks: fragment. */
	if (oiph->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;

nskb = alloc_skb(sizeof(struct iphdr) + sizeof(struct tcphdr) +
	                 LL_MAX_HEADER, GFP_ATOMIC);
	if (nskb == NULL)
		return;

skb_reserve(nskb, LL_MAX_HEADER);
	skb_reset_network_header(nskb);
	niph = (struct iphdr *)skb_put(nskb, sizeof(struct iphdr));
	niph->version  = 4;
	niph->ihl      = sizeof(struct iphdr) / 4;
	niph->tos      = 0;
	niph->id       = 0;
	niph->frag_off = htons(IP_DF);
	niph->protocol = IPPROTO_TCP;
	niph->check    = 0;
	niph->saddr    = oiph->daddr;
	niph->daddr    = oiph->saddr;

tcph = (struct tcphdr *)skb_put(nskb, sizeof(struct tcphdr));
	memset(tcph, 0, sizeof(*tcph));
	tcph->source = oth->dest;
	tcph->dest   = oth->source;
	tcph->doff   = sizeof(struct tcphdr) / 4;

/* DELUDE essential part */
	if (oth->syn && !oth->ack && !oth->rst && !oth->fin) {
		tcph->syn     = true;
		tcph->seq     = 0;
		tcph->ack     = true;
		tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn + oth->fin +
		                oldskb->len - ip_hdrlen(oldskb) -
		                (oth->doff << 2));
	} else {
		tcph->rst = true;
		if (!oth->ack) {
			tcph->seq     = 0;
			tcph->ack     = true;
			tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn +
			                oth->fin + oldskb->len -
			                ip_hdrlen(oldskb) - (oth->doff << 2));
		} else {
			tcph->seq     = oth->ack_seq;
			tcph->ack     = false;
			tcph->ack_seq = 0;
		}
	}

tcph->check = tcp_v4_check(sizeof(struct tcphdr), niph->saddr,
	              niph->daddr, csum_partial((char *)tcph,
	              sizeof(struct tcphdr), 0));

addr_type = RTN_UNSPEC;
#ifdef CONFIG_BRIDGE_NETFILTER
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 1, 0)
	if (hook != NF_INET_FORWARD || (nskb->nf_bridge != NULL &&
	    nskb->nf_bridge->physoutdev))
#else
	if (hook != NF_INET_FORWARD || (nskb->nf_bridge != NULL &&
	    nskb->nf_bridge->mask & BRNF_BRIDGED))
#endif
#else
	if (hook != NF_INET_FORWARD)
#endif
		addr_type = RTN_LOCAL;

/* ip_route_me_harder expects skb->dst to be set */
	skb_dst_set(nskb, dst_clone(skb_dst(oldskb)));

if (ip_route_me_harder(net, nskb, addr_type))
		goto free_nskb;
	else
		niph = ip_hdr(nskb);

niph->ttl       = dst_metric(skb_dst(nskb), RTAX_HOPLIMIT);
	nskb->ip_summed = CHECKSUM_NONE;

/* "Never happens" */
	if (nskb->len > dst_mtu(skb_dst(nskb)))
		goto free_nskb;

nf_ct_attach(nskb, oldskb);

ip_local_out(net, nskb->sk, nskb);
	return;

free_nskb:
	kfree_skb(nskb);
}

static unsigned int
delude_tg(struct sk_buff *skb, const struct xt_action_param *par)
{
	/*
	 * Sending the reset causes reentrancy within iptables - and should not pose
	 * a problem, as that is supported since Linux 2.6.35. But since we do not
	 * actually want to have a connection open, we are still going to drop it.
	 */
	delude_send_reset(par_net(par), skb,
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)
	                  par->state->hook
#else
	                  par->hooknum
#endif
	                  );
	return NF_DROP;
}

static struct xt_target delude_tg_reg __read_mostly = {
	.name     = "DELUDE",
	.revision = 0,
	.family   = NFPROTO_IPV4,
	.table    = "filter",
	.hooks    = (1 << NF_INET_LOCAL_IN) | (1 << NF_INET_FORWARD),
	.proto    = IPPROTO_TCP,
	.target   = delude_tg,
	.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_DESCRIPTION("Xtables: Close TCP connections after handshake");
MODULE_AUTHOR("Jan Engelhardt ");
MODULE_LICENSE("GPL");
MODULE_ALIAS("ipt_DELUDE");

${this.title}

Code Editor : xt_DELUDE.c