diff options
Diffstat (limited to 'target/linux/generic-2.6')
| -rw-r--r-- | target/linux/generic-2.6/patches/170-netfilter_chaostables.patch | 880 |
1 files changed, 880 insertions, 0 deletions
diff --git a/target/linux/generic-2.6/patches/170-netfilter_chaostables.patch b/target/linux/generic-2.6/patches/170-netfilter_chaostables.patch new file mode 100644 index 0000000..46d48a5 --- /dev/null +++ b/target/linux/generic-2.6/patches/170-netfilter_chaostables.patch @@ -0,0 +1,880 @@ +diff -ruN linux-2.6.19.1.orig/include/linux/netfilter/xt_CHAOS.h linux-2.6.19.1/include/linux/netfilter/xt_CHAOS.h +--- linux-2.6.19.1.orig/include/linux/netfilter/xt_CHAOS.h 1970-01-01 01:00:00.000000000 +0100 ++++ linux-2.6.19.1/include/linux/netfilter/xt_CHAOS.h 2007-01-11 13:28:07.656144799 +0100 +@@ -0,0 +1,14 @@ ++#ifndef _LINUX_XT_CHAOS_H ++#define _LINUX_XT_CHAOS_H 1 ++ ++enum xt_chaos_variant { ++ XTCHAOS_NORMAL, ++ XTCHAOS_TARPIT, ++ XTCHAOS_DELUDE, ++}; ++ ++struct xt_chaos_info { ++ enum xt_chaos_variant variant; ++}; ++ ++#endif /* _LINUX_XT_CHAOS_H */ +diff -ruN linux-2.6.19.1.orig/include/linux/netfilter/xt_portscan.h linux-2.6.19.1/include/linux/netfilter/xt_portscan.h +--- linux-2.6.19.1.orig/include/linux/netfilter/xt_portscan.h 1970-01-01 01:00:00.000000000 +0100 ++++ linux-2.6.19.1/include/linux/netfilter/xt_portscan.h 2007-01-11 13:28:07.656144799 +0100 +@@ -0,0 +1,8 @@ ++#ifndef _LINUX_XT_PORTSCAN_H ++#define _LINUX_XT_PORTSCAN_H 1 ++ ++struct xt_portscan_info { ++ unsigned int match_stealth, match_syn, match_cn, match_gr; ++}; ++ ++#endif /* _LINUX_XT_PORTSCAN_H */ +diff -ruN linux-2.6.19.1.orig/net/netfilter/find_match.c linux-2.6.19.1/net/netfilter/find_match.c +--- linux-2.6.19.1.orig/net/netfilter/find_match.c 1970-01-01 01:00:00.000000000 +0100 ++++ linux-2.6.19.1/net/netfilter/find_match.c 2007-01-11 13:28:12.191994379 +0100 +@@ -0,0 +1,37 @@ ++/* ++ 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(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; ++} +diff -ruN linux-2.6.19.1.orig/net/netfilter/Kconfig linux-2.6.19.1/net/netfilter/Kconfig +--- linux-2.6.19.1.orig/net/netfilter/Kconfig 2007-01-11 13:27:24.445577700 +0100 ++++ linux-2.6.19.1/net/netfilter/Kconfig 2007-01-11 13:28:09.092097179 +0100 +@@ -122,6 +122,14 @@ + + # 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 +@@ -148,6 +156,14 @@ + <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 +@@ -355,6 +371,14 @@ + + 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 +diff -ruN linux-2.6.19.1.orig/net/netfilter/Makefile linux-2.6.19.1/net/netfilter/Makefile +--- linux-2.6.19.1.orig/net/netfilter/Makefile 2007-01-11 13:27:24.445577700 +0100 ++++ linux-2.6.19.1/net/netfilter/Makefile 2007-01-11 13:28:07.656144799 +0100 +@@ -23,8 +23,10 @@ + obj-$(CONFIG_NETFILTER_XTABLES) += x_tables.o xt_tcpudp.o + + # targets ++obj-$(CONFIG_NETFILTER_XT_TARGET_CHAOS) += xt_CHAOS.o + obj-$(CONFIG_NETFILTER_XT_TARGET_CLASSIFY) += xt_CLASSIFY.o + obj-$(CONFIG_NETFILTER_XT_TARGET_CONNMARK) += xt_CONNMARK.o ++obj-$(CONFIG_NETFILTER_XT_TARGET_DELUDE) += xt_DELUDE.o + obj-$(CONFIG_NETFILTER_XT_TARGET_DSCP) += xt_DSCP.o + obj-$(CONFIG_NETFILTER_XT_TARGET_MARK) += xt_MARK.o + obj-$(CONFIG_NETFILTER_XT_TARGET_NFQUEUE) += xt_NFQUEUE.o +@@ -47,6 +49,7 @@ + obj-$(CONFIG_NETFILTER_XT_MATCH_MARK) += xt_mark.o + obj-$(CONFIG_NETFILTER_XT_MATCH_MULTIPORT) += xt_multiport.o + obj-$(CONFIG_NETFILTER_XT_MATCH_POLICY) += xt_policy.o ++obj-$(CONFIG_NETFILTER_XT_MATCH_PORTSCAN) += xt_portscan.o + obj-$(CONFIG_NETFILTER_XT_MATCH_PKTTYPE) += xt_pkttype.o + obj-$(CONFIG_NETFILTER_XT_MATCH_QUOTA) += xt_quota.o + obj-$(CONFIG_NETFILTER_XT_MATCH_REALM) += xt_realm.o +diff -ruN linux-2.6.19.1.orig/net/netfilter/xt_CHAOS.c linux-2.6.19.1/net/netfilter/xt_CHAOS.c +--- linux-2.6.19.1.orig/net/netfilter/xt_CHAOS.c 1970-01-01 01:00:00.000000000 +0100 ++++ linux-2.6.19.1/net/netfilter/xt_CHAOS.c 2007-01-11 13:28:14.407920893 +0100 +@@ -0,0 +1,180 @@ ++/* ++ CHAOS target for netfilter ++ ++ Copyright © Jan Engelhardt <jengelh [at] gmx de>, 2006 - 2007 ++ released under the terms of the GNU General Public ++ License version 2.x and only versions 2.x. ++*/ ++#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> ++#include <linux/netfilter/xt_CHAOS.h> ++#include "find_match.c" ++#define PFX KBUILD_MODNAME ": " ++ ++/* Out of tree workarounds */ ++#include <linux/version.h> ++#if LINUX_VERSION_CODE <= KERNEL_VERSION(2, 6, 18) ++# define HAVE_TARGUSERINFO 1 ++#endif ++ ++/* 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 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_info *info, ++ struct sk_buff **pskb, const struct net_device *in, ++ const struct net_device *out, unsigned int hooknum) ++{ ++ const int protoff = 4 * (*pskb)->nh.iph->ihl; ++ const int offset = ntohs((*pskb)->nh.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; ++#ifdef HAVE_TARGUSERINFO ++ destiny->target(pskb, in, out, hooknum, destiny, NULL, NULL); ++#else ++ destiny->target(pskb, in, out, hooknum, destiny, NULL); ++#endif ++ return; ++} ++ ++static unsigned int xt_chaos_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 ++#ifdef HAVE_TARGUSERINFO ++ , ++ void *userinfo ++#endif ++ ) ++{ ++ /* Equivalent to: ++ * -A chaos -m statistic --mode random --probability \ ++ * $reject_percentage -j REJECT --reject-with host-unreach; ++ * -A chaos -m statistic --mode random --probability \ ++ * $delude_percentage -j DELUDE; ++ * -A chaos -j DROP; ++ */ ++ const struct xt_chaos_info *info = targinfo; ++ ++ if((unsigned int)net_random() <= reject_percentage) ++#ifdef HAVE_TARGUSERINFO ++ return xt_reject->target(pskb, in, out, hooknum, target, ++ &reject_params, userinfo); ++#else ++ return xt_reject->target(pskb, in, out, hooknum, target, ++ &reject_params); ++#endif ++ ++ /* TARPIT/DELUDE may not be called from the OUTPUT chain */ ++ if((*pskb)->nh.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 struct xt_target xt_chaos_info = { ++ .name = "CHAOS", ++ .target = xt_chaos_target, ++ .table = "filter", ++ .targetsize = sizeof(struct xt_chaos_info), ++ .hooks = (1 << NF_IP_LOCAL_IN) | (1 << NF_IP_FORWARD) | ++ (1 << NF_IP_LOCAL_OUT), ++ .family = AF_INET, ++ .me = THIS_MODULE, ++}; ++ ++static int __init xt_chaos_init(void) ++{ ++ int ret = -EINVAL; ++ ++ xm_tcp = xt_request_find_match(AF_INET, "tcp", 0); ++ if(xm_tcp == NULL) { ++ printk(KERN_WARNING PFX "Could not find \"tcp\" match\n"); ++ return -EINVAL; ++ } ++ ++ xt_reject = xt_request_find_target(AF_INET, "REJECT", 0); ++ if(xt_reject == NULL) { ++ printk(KERN_WARNING PFX "Could not find \"REJECT\" target\n"); ++ goto out2; ++ } ++ ++ xt_tarpit = xt_request_find_target(AF_INET, "TARPIT", 0); ++ if(xt_tarpit == NULL) { ++ printk(KERN_WARNING PFX "Could not find \"TARPIT\" target\n"); ++ goto out3; ++ } ++ ++ xt_delude = xt_request_find_target(AF_INET, "DELUDE", 0); ++ if(xt_delude == NULL) { ++ printk(KERN_WARNING PFX "Could not find \"DELUDE\" target\n"); ++ goto out4; ++ } ++ ++ if((ret = xt_register_target(&xt_chaos_info)) != 0) { ++ printk(KERN_WARNING PFX "xt_register_target returned " ++ "error %d\n", ret); ++ goto out5; ++ } ++ ++ return 0; ++ ++ out5: ++ module_put(xt_delude->me); ++ out4: ++ module_put(xt_tarpit->me); ++ out3: ++ module_put(xt_reject->me); ++ out2: ++ module_put(xm_tcp->me); ++ return ret; ++} ++ ++static void __exit xt_chaos_exit(void) ++{ ++ xt_unregister_target(&xt_chaos_info); ++ module_put(xm_tcp->me); ++ module_put(xt_reject->me); ++ module_put(xt_delude->me); ++ module_put(xt_tarpit->me); ++ return; ++} ++ ++module_init(xt_chaos_init); ++module_exit(xt_chaos_exit); ++MODULE_AUTHOR("Jan Engelhardt <jengelh@gmx.de>"); ++MODULE_DESCRIPTION("netfilter CHAOS target"); ++MODULE_LICENSE("GPL"); ++MODULE_ALIAS("ipt_CHAOS"); +diff -ruN linux-2.6.19.1.orig/net/netfilter/xt_DELUDE.c linux-2.6.19.1/net/netfilter/xt_DELUDE.c +--- linux-2.6.19.1.orig/net/netfilter/xt_DELUDE.c 1970-01-01 01:00:00.000000000 +0100 ++++ linux-2.6.19.1/net/netfilter/xt_DELUDE.c 2007-01-11 13:28:07.656144799 +0100 +@@ -0,0 +1,265 @@ ++/* ++ DELUDE target ++ Copyright © Jan Engelhardt <jengelh [at] gmx de>, 2007 ++ ++ 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> ++ ++ 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/udp.h> ++#include <linux/icmp.h> ++#include <net/icmp.h> ++#include <net/ip.h> ++#include <net/tcp.h> ++#include <net/route.h> ++#include <net/dst.h> ++#include <linux/netfilter_ipv4/ip_tables.h> ++#ifdef CONFIG_BRIDGE_NETFILTER ++#include <linux/netfilter_bridge.h> ++#endif ++#define PFX KBUILD_MODNAME ": " ++ ++/* Out of tree workarounds */ ++#include <linux/version.h> ++#if LINUX_VERSION_CODE <= KERNEL_VERSION(2, 6, 18) ++# define HAVE_TARGINFOSIZE 1 ++# define HAVE_TARGUSERINFO 1 ++#endif ++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 20) ++# define nfmark mark ++#endif ++ ++static inline struct rtable *route_reverse(struct sk_buff *skb, ++ struct tcphdr *tcph, int hook) ++{ ++ struct iphdr *iph = skb->nh.iph; ++ struct dst_entry *odst; ++ struct flowi fl = {}; ++ struct rtable *rt; ++ ++ /* We don't require ip forwarding to be enabled to be able to ++ * send a RST reply for bridged traffic. */ ++ if (hook != NF_IP_FORWARD ++#ifdef CONFIG_BRIDGE_NETFILTER ++ || (skb->nf_bridge && skb->nf_bridge->mask & BRNF_BRIDGED) ++#endif ++ ) { ++ fl.nl_u.ip4_u.daddr = iph->saddr; ++ if (hook == NF_IP_LOCAL_IN) ++ fl.nl_u.ip4_u.saddr = iph->daddr; ++ fl.nl_u.ip4_u.tos = RT_TOS(iph->tos); ++ ++ if (ip_route_output_key(&rt, &fl) != 0) ++ return NULL; ++ } else { ++ /* non-local src, find valid iif to satisfy ++ * rp-filter when calling ip_route_input. */ ++ fl.nl_u.ip4_u.daddr = iph->daddr; ++ if (ip_route_output_key(&rt, &fl) != 0) ++ return NULL; ++ ++ odst = skb->dst; ++ if (ip_route_input(skb, iph->saddr, iph->daddr, ++ RT_TOS(iph->tos), rt->u.dst.dev) != 0) { ++ dst_release(&rt->u.dst); ++ return NULL; ++ } ++ dst_release(&rt->u.dst); ++ rt = (struct rtable *)skb->dst; ++ skb->dst = odst; ++ ++ fl.nl_u.ip4_u.daddr = iph->saddr; ++ fl.nl_u.ip4_u.saddr = iph->daddr; ++ fl.nl_u.ip4_u.tos = RT_TOS(iph->tos); ++ } ++ ++ if (rt->u.dst.error) { ++ dst_release(&rt->u.dst); ++ return NULL; ++ } ++ ++ fl.proto = IPPROTO_TCP; ++ fl.fl_ip_sport = tcph->dest; ++ fl.fl_ip_dport = tcph->source; ++ ++ xfrm_lookup((struct dst_entry **)&rt, &fl, NULL, 0); ++ ++ return rt; ++} ++ ++static void send_reset(struct sk_buff *oldskb, int hook) ++{ ++ struct sk_buff *nskb; ++ struct iphdr *iph = oldskb->nh.iph; ++ struct tcphdr _otcph, *oth, *tcph; ++ struct rtable *rt; ++ u_int16_t tmp_port; ++ u_int32_t tmp_addr; ++ int hh_len; ++ ++ /* IP header checks: fragment. */ ++ if (oldskb->nh.iph->frag_off & htons(IP_OFFSET)) ++ return; ++ ++ oth = skb_header_pointer(oldskb, oldskb->nh.iph->ihl * 4, ++ sizeof(_otcph), &_otcph); ++ if (oth == NULL) ++ return; ++ ++ /* DELUDE only answers SYN. */ ++ if(!oth->syn || oth->ack || oth->fin || oth->rst) ++ return; ++ ++ /* Check checksum */ ++ if (nf_ip_checksum(oldskb, hook, iph->ihl * 4, IPPROTO_TCP)) ++ return; ++ ++ if ((rt = route_reverse(oldskb, oth, hook)) == NULL) ++ return; ++ ++ hh_len = LL_RESERVED_SPACE(rt->u.dst.dev); ++ ++ /* 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, hh_len, skb_tailroom(oldskb), ++ GFP_ATOMIC); ++ if (!nskb) { ++ dst_release(&rt->u.dst); ++ return; ++ } ++ ++ dst_release(nskb->dst); ++ nskb->dst = &rt->u.dst; ++ ++ /* This packet will not be the same as the other: clear nf fields */ ++ nf_reset(nskb); ++ nskb->nfmark = 0; ++ skb_init_secmark(nskb); ++ ++ tcph = (struct tcphdr *)((u_int32_t*)nskb->nh.iph + nskb->nh.iph->ihl); ++ ++ /* Swap source and dest */ ++ tmp_addr = nskb->nh.iph->saddr; ++ nskb->nh.iph->saddr = nskb->nh.iph->daddr; ++ nskb->nh.iph->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, nskb->nh.iph->ihl*4 + sizeof(struct tcphdr)); ++ nskb->nh.iph->tot_len = htons(nskb->len); ++ ++ tcph->seq = oth->ack_seq; ++ tcph->ack_seq = 0; ++ ++ /* Reset flags */ ++ ((u_int8_t *)tcph)[13] = 0; ++ tcph->syn = tcph->ack = 1; ++ ++ tcph->window = 0; ++ tcph->urg_ptr = 0; ++ ++ /* Adjust TCP checksum */ ++ tcph->check = 0; ++ tcph->check = tcp_v4_check(tcph, sizeof(struct tcphdr), ++ nskb->nh.iph->saddr, ++ nskb->nh.iph->daddr, ++ csum_partial((char *)tcph, ++ sizeof(struct tcphdr), 0)); ++ ++ /* Adjust IP TTL, DF */ ++ nskb->nh.iph->ttl = dst_metric(nskb->dst, RTAX_HOPLIMIT); ++ /* Set DF, id = 0 */ ++ nskb->nh.iph->frag_off = htons(IP_DF); ++ nskb->nh.iph->id = 0; ++ ++ /* Adjust IP checksum */ ++ nskb->nh.iph->check = 0; ++ nskb->nh.iph->check = ip_fast_csum((unsigned char *)nskb->nh.iph, ++ nskb->nh.iph->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); ++ return; ++} ++ ++static unsigned int xt_delude_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 ++#ifdef HAVE_TARGUSERINFO ++ , ++ void *userinfo ++#endif ++ ) ++{ ++ /* WARNING: This code causes reentry within iptables. ++ This means that the iptables jump stack is now crap. We ++ must return an absolute verdict. --RR */ ++ send_reset(*pskb, hooknum); ++ return NF_DROP; ++} ++ ++static int xt_delude_check(const char *tablename, const void *e_void, ++ const struct xt_target *target, void *targinfo, ++#ifdef HAVE_TARGINFOSIZE ++ unsigned int targinfosize, ++#endif ++ unsigned int hook_mask) ++{ ++ if(hook_mask & ~((1 << NF_IP_LOCAL_IN) | (1 << NF_IP_FORWARD))) { ++ printk(KERN_WARNING PFX "DELUDE may not be used in chains " ++ "other than INPUT and FORWARD\n"); ++ return 0; ++ } ++ return 1; ++} ++ ++static struct xt_target xt_delude_info = { ++ .name = "DELUDE", ++ .target = xt_delude_target, ++ .checkentry = xt_delude_check, ++ .table = "filter", ++ .hooks = (1 << NF_IP_LOCAL_IN) | (1 << NF_IP_FORWARD) | ++ (1 << NF_IP_LOCAL_OUT), ++ .proto = IPPROTO_TCP, ++ .family = AF_INET, ++ .me = THIS_MODULE, ++}; ++ ++static int __init xt_delude_init(void) ++{ ++ return xt_register_target(&xt_delude_info); ++} ++ ++static void __exit xt_delude_exit(void) ++{ ++ xt_unregister_target(&xt_delude_info); ++} ++ ++module_init(xt_delude_init); ++module_exit(xt_delude_exit); ++MODULE_LICENSE("GPL"); ++MODULE_AUTHOR("Jan Engelhardt <jengelh@gmx.de>"); ++MODULE_DESCRIPTION("netfilter DELUDE target"); +diff -ruN linux-2.6.19.1.orig/net/netfilter/xt_portscan.c linux-2.6.19.1/net/netfilter/xt_portscan.c +--- linux-2.6.19.1.orig/net/netfilter/xt_portscan.c 1970-01-01 01:00:00.000000000 +0100 ++++ linux-2.6.19.1/net/netfilter/xt_portscan.c 2007-01-11 13:28:14.407920893 +0100 +@@ -0,0 +1,282 @@ ++/* ++ portscan match for netfilter ++ ++ Written by Jan Engelhardt, 2006 - 2007 ++ released under the terms of the GNU General Public ++ License version 2.x and only versions 2.x. ++*/ ++#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> ++#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 ++#include <linux/netfilter/xt_portscan.h> ++#define PFX KBUILD_MODNAME ": " ++ ++/* Out of tree workarounds */ ++#if LINUX_VERSION_CODE <= KERNEL_VERSION(2, 6, 18) ++# define HAVE_MATCHINFOSIZE 1 ++#endif ++#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 20) ++# define nfmark mark ++#endif ++ ++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 int tflg_ack4(const struct tcphdr *th) ++{ ++ return (tcp_flag_word(th) & TCP_FLAGS_ALL4) == TCP_FLAG_ACK; ++} ++ ++static inline int tflg_ack6(const struct tcphdr *th) ++{ ++ return (tcp_flag_word(th) & TCP_FLAGS_ALL6) == TCP_FLAG_ACK; ++} ++ ++static inline int tflg_fin(const struct tcphdr *th) ++{ ++ return (tcp_flag_word(th) & TCP_FLAGS_ALL3) == TCP_FLAG_FIN; ++} ++ ++static inline int tflg_rst(const struct tcphdr *th) ++{ ++ return (tcp_flag_word(th) & TCP_FLAGS_ALL3) == TCP_FLAG_RST; ++} ++ ++static inline int tflg_rstack(const struct tcphdr *th) ++{ ++ return (tcp_flag_word(th) & TCP_FLAGS_ALL4) == ++ (TCP_FLAG_ACK | TCP_FLAG_RST); ++} ++ ++static inline int tflg_syn(const struct tcphdr *th) ++{ ++ return (tcp_flag_word(th) & TCP_FLAGS_ALL4) == TCP_FLAG_SYN; ++} ++ ++static inline int tflg_synack(const struct tcphdr *th) ++{ ++ return (tcp_flag_word(th) & TCP_FLAGS_ALL4) == ++ (TCP_FLAG_SYN | TCP_FLAG_ACK); ++} ++ ++/* portscan functions */ ++static inline int xt_portscan_stealth(const struct tcphdr *th) ++{ ++ /* ++ * "Connection refused" replies to our own probes must not be matched. ++ */ ++ if(tflg_rstack(th)) ++ return 0; ++ ++ if(tflg_rst(th) && printk_ratelimit()) { ++ printk(KERN_WARNING PFX "Warning: Pure RST received\n"); ++ return 0; ++ } ++ ++ /* ++ * -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 int xt_portscan_full(int mark, enum ip_conntrack_info ctstate, ++ int loopback, const struct tcphdr *tcph, 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 xt_portscan_match(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_info *info = matchinfo; ++ enum ip_conntrack_info ctstate; ++ struct ip_conntrack *ctdata; ++ const struct tcphdr *tcph; ++ struct tcphdr tcph_buf; ++ ++ tcph = skb_header_pointer(skb, protoff, sizeof(tcph_buf), &tcph_buf); ++ if(tcph == NULL) ++ return 0; ++ ++ /* Check for invalid packets: -m conntrack --ctstate INVALID */ ++ if((ctdata = ip_conntrack_get(skb, &ctstate)) == NULL) { ++ if(info->match_stealth) ++ return xt_portscan_stealth(tcph); ++ /* ++ * If @ctdata is NULL, we cannot match the other scan ++ * types, return. ++ */ ++ return 0; ++ } ++ ++ /* ++ * 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->nfmark & packet_mask) != mark_seen) ++ { ++ unsigned int n; ++ n = xt_portscan_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)->nfmark = ++ (skb->nfmark & ~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 xt_portscan_checkentry(const char *tablename, const void *entry, ++ const struct xt_match *match, void *matchinfo, ++#ifdef HAVE_MATCHINFOSIZE ++ unsigned int matchinfosize, ++#endif ++ unsigned int hook_mask) ++{ ++ const struct xt_portscan_info *info = matchinfo; ++#ifdef HAVE_MATCHINFOSIZE ++ if(matchinfosize != XT_ALIGN(sizeof(struct xt_portscan_info))) { ++ printk(KERN_WARNING PFX "matchinfosize %u != %Zu\n", ++ matchinfosize, ++ XT_ALIGN(sizeof(struct xt_portscan_info))); ++ return 0; ++ } ++#endif ++ 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 0; ++ } ++ return 1; ++} ++ ++static struct xt_match xt_portscan = { ++ .name = "portscan", ++ .match = xt_portscan_match, ++ .checkentry = xt_portscan_checkentry, ++ .matchsize = sizeof(struct xt_portscan_info), ++ .proto = IPPROTO_TCP, ++ .family = AF_INET, ++ .me = THIS_MODULE, ++}; ++ ++static int __init xt_portscan_init(void) ++{ ++ return xt_register_match(&xt_portscan); ++} ++ ++static void __exit xt_portscan_exit(void) ++{ ++ xt_unregister_match(&xt_portscan); ++ return; ++} ++ ++module_init(xt_portscan_init); ++module_exit(xt_portscan_exit); ++MODULE_AUTHOR("Jan Engelhardt <jengelh@gmx.de>"); ++MODULE_DESCRIPTION("netfilter portscan match module"); ++MODULE_LICENSE("GPL"); ++MODULE_ALIAS("ipt_portscan"); |