From 5bd47dc8bd8b44933c0888c304cd66851551a56f Mon Sep 17 00:00:00 2001
From: Gabor Juhos <juhosg@openwrt.org>
Date: Mon, 18 Feb 2008 08:03:28 +0000
Subject: [PATCH] generic-2.4: add ip6t_REJECT support
SVN-Revision: 10482
---
target/linux/generic-2.4/config-default | 1 +
.../patches/623-netfilter_ip6t_reject.patch | 360 ++++++++++++++++++
2 files changed, 361 insertions(+)
create mode 100644 target/linux/generic-2.4/patches/623-netfilter_ip6t_reject.patch
diff --git a/target/linux/generic-2.4/config-default b/target/linux/generic-2.4/config-default
index 411e2c3aca..acf57937a1 100644
--- a/target/linux/generic-2.4/config-default
+++ b/target/linux/generic-2.4/config-default
@@ -198,6 +198,7 @@ CONFIG_IP6_NF_MATCH_RANDOM=m
CONFIG_IP6_NF_TARGET_IMQ=m
CONFIG_IP6_NF_TARGET_LOG=m
CONFIG_IP6_NF_TARGET_MARK=m
+CONFIG_IP6_NF_TARGET_REJECT=m
# CONFIG_IPMI_DEVICE_INTERFACE is not set
# CONFIG_IPMI_HANDLER is not set
# CONFIG_IPMI_KCS is not set
diff --git a/target/linux/generic-2.4/patches/623-netfilter_ip6t_reject.patch b/target/linux/generic-2.4/patches/623-netfilter_ip6t_reject.patch
new file mode 100644
index 0000000000..2caae3ab01
--- /dev/null
+++ b/target/linux/generic-2.4/patches/623-netfilter_ip6t_reject.patch
@@ -0,0 +1,360 @@
+Index: linux-2.4.35.4/net/ipv6/netfilter/ip6t_REJECT.c
+===================================================================
+--- /dev/null
++++ linux-2.4.35.4/net/ipv6/netfilter/ip6t_REJECT.c
+@@ -0,0 +1,301 @@
++/*
++ * This is a module which is used for rejecting packets.
++ * Added support for customized reject packets (Jozsef Kadlecsik).
++ * Sun 12 Nov 2000
++ * Port to IPv6 / ip6tables (Harald Welte <laforge@gnumonks.org>)
++ */
++#include <linux/config.h>
++#include <linux/module.h>
++#include <linux/skbuff.h>
++#include <linux/icmpv6.h>
++#include <net/tcp.h>
++#include <net/ipv6.h>
++#include <net/ip6_fib.h>
++#include <net/ip6_route.h>
++#include <linux/netfilter_ipv6/ip6_tables.h>
++#include <linux/netfilter_ipv6/ip6t_REJECT.h>
++
++#if 1
++#define DEBUGP printk
++#else
++#define DEBUGP(format, args...)
++#endif
++
++#if 0
++/* Send RST reply */
++static void send_reset(struct sk_buff *oldskb)
++{
++ struct sk_buff *nskb;
++ struct tcphdr *otcph, *tcph;
++ struct rtable *rt;
++ unsigned int otcplen;
++ int needs_ack;
++
++ /* IP header checks: fragment, too short. */
++ if (oldskb->nh.iph->frag_off & htons(IP_OFFSET)
++ || oldskb->len < (oldskb->nh.iph->ihl<<2) + sizeof(struct tcphdr))
++ return;
++
++ otcph = (struct tcphdr *)((u_int32_t*)oldskb->nh.iph + oldskb->nh.iph->ihl);
++ otcplen = oldskb->len - oldskb->nh.iph->ihl*4;
++
++ /* No RST for RST. */
++ if (otcph->rst)
++ return;
++
++ /* Check checksum. */
++ if (tcp_v4_check(otcph, otcplen, oldskb->nh.iph->saddr,
++ oldskb->nh.iph->daddr,
++ csum_partial((char *)otcph, otcplen, 0)) != 0)
++ return;
++
++ /* Copy skb (even if skb is about to be dropped, we can't just
++ clone it because there may be other things, such as tcpdump,
++ interested in it) */
++ nskb = skb_copy(oldskb, GFP_ATOMIC);
++ if (!nskb)
++ return;
++
++ /* This packet will not be the same as the other: clear nf fields */
++ nf_conntrack_put(nskb->nfct);
++ nskb->nfct = NULL;
++ nskb->nfcache = 0;
++#ifdef CONFIG_NETFILTER_DEBUG
++ nskb->nf_debug = 0;
++#endif
++
++ tcph = (struct tcphdr *)((u_int32_t*)nskb->nh.iph + nskb->nh.iph->ihl);
++
++ nskb->nh.iph->daddr = xchg(&nskb->nh.iph->saddr, nskb->nh.iph->daddr);
++ tcph->source = xchg(&tcph->dest, tcph->source);
++
++ /* 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);
++
++ if (tcph->ack) {
++ needs_ack = 0;
++ tcph->seq = otcph->ack_seq;
++ tcph->ack_seq = 0;
++ } else {
++ needs_ack = 1;
++ tcph->ack_seq = htonl(ntohl(otcph->seq) + otcph->syn + otcph->fin
++ + otcplen - (otcph->doff<<2));
++ tcph->seq = 0;
++ }
++
++ /* Reset flags */
++ ((u_int8_t *)tcph)[13] = 0;
++ tcph->rst = 1;
++ tcph->ack = needs_ack;
++
++ 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 = MAXTTL;
++ /* 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);
++
++ /* Routing */
++ if (ip_route_output(&rt, nskb->nh.iph->daddr, nskb->nh.iph->saddr,
++ RT_TOS(nskb->nh.iph->tos) | RTO_CONN,
++ 0) != 0)
++ goto free_nskb;
++
++ dst_release(nskb->dst);
++ nskb->dst = &rt->u.dst;
++
++ /* "Never happens" */
++ if (nskb->len > nskb->dst->pmtu)
++ goto free_nskb;
++
++ NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, nskb, NULL, nskb->dst->dev,
++ ip_finish_output);
++ return;
++
++ free_nskb:
++ kfree_skb(nskb);
++}
++#endif
++
++static unsigned int reject6_target(struct sk_buff **pskb,
++ unsigned int hooknum,
++ const struct net_device *in,
++ const struct net_device *out,
++ const void *targinfo,
++ void *userinfo)
++{
++ const struct ip6t_reject_info *reject = targinfo;
++ struct sk_buff *skb2 = NULL;
++ struct rt6_info *rt6i;
++ struct net_device odev;
++
++ if (!out) {
++ skb2 = skb_clone(*pskb, GFP_ATOMIC);
++ if (skb2 == NULL) {
++ return NF_DROP;
++ }
++ dst_release(skb2->dst);
++ skb2->dst = NULL;
++
++ rt6i = rt6_lookup(&skb2->nh.ipv6h->saddr, NULL, 0, 0);
++ if (rt6i && rt6i->rt6i_dev) {
++ skb2->dev = rt6i->rt6i_dev;
++ rt6i = rt6_lookup(&skb2->nh.ipv6h->daddr, &skb2->nh.ipv6h->saddr, 0, 0);
++ }
++ memcpy(&odev, skb2->dev, sizeof(odev)); /* XXX 'out' has 'const' qualifier... */
++ } else {
++ memcpy(&odev, out, sizeof(odev));
++ }
++
++ printk(KERN_DEBUG "%s: medium point\n", __FUNCTION__);
++ /* WARNING: This code causes reentry within ip6tables.
++ This means that the ip6tables jump stack is now crap. We
++ must return an absolute verdict. --RR */
++ DEBUGP("REJECTv6: calling icmpv6_send\n");
++ switch (reject->with) {
++ case IP6T_ICMP6_NO_ROUTE:
++ icmpv6_send(*pskb, ICMPV6_DEST_UNREACH, ICMPV6_NOROUTE, 0, &odev);
++ break;
++ case IP6T_ICMP6_ADM_PROHIBITED:
++ icmpv6_send(*pskb, ICMPV6_DEST_UNREACH, ICMPV6_ADM_PROHIBITED, 0, &odev);
++ break;
++ case IP6T_ICMP6_NOT_NEIGHBOUR:
++ icmpv6_send(*pskb, ICMPV6_DEST_UNREACH, ICMPV6_NOT_NEIGHBOUR, 0, &odev);
++ break;
++ case IP6T_ICMP6_ADDR_UNREACH:
++ icmpv6_send(*pskb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0, &odev);
++ break;
++ case IP6T_ICMP6_PORT_UNREACH:
++ icmpv6_send(*pskb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0, &odev);
++ break;
++#if 0
++ case IPT_ICMP_ECHOREPLY: {
++ struct icmp6hdr *icmph = (struct icmphdr *)
++ ((u_int32_t *)(*pskb)->nh.iph + (*pskb)->nh.iph->ihl);
++ unsigned int datalen = (*pskb)->len - (*pskb)->nh.iph->ihl * 4;
++
++ /* Not non-head frags, or truncated */
++ if (((ntohs((*pskb)->nh.iph->frag_off) & IP_OFFSET) == 0)
++ && datalen >= 4) {
++ /* Usually I don't like cut & pasting code,
++ but dammit, my party is starting in 45
++ mins! --RR */
++ struct icmp_bxm icmp_param;
++
++ icmp_param.icmph=*icmph;
++ icmp_param.icmph.type=ICMP_ECHOREPLY;
++ icmp_param.data_ptr=(icmph+1);
++ icmp_param.data_len=datalen;
++ icmp_reply(&icmp_param, *pskb);
++ }
++ }
++ break;
++ case IPT_TCP_RESET:
++ send_reset(*pskb);
++ break;
++#endif
++ default:
++ printk(KERN_WARNING "REJECTv6: case %u not handled yet\n", reject->with);
++ break;
++ }
++
++ if (skb2) kfree_skb(skb2);
++
++ return NF_DROP;
++}
++
++static inline int find_ping_match(const struct ip6t_entry_match *m)
++{
++ const struct ip6t_icmp *icmpinfo = (const struct ip6t_icmp *)m->data;
++
++ if (strcmp(m->u.kernel.match->name, "icmp6") == 0
++ && icmpinfo->type == ICMPV6_ECHO_REQUEST
++ && !(icmpinfo->invflags & IP6T_ICMP_INV))
++ return 1;
++
++ return 0;
++}
++
++static int check(const char *tablename,
++ const struct ip6t_entry *e,
++ void *targinfo,
++ unsigned int targinfosize,
++ unsigned int hook_mask)
++{
++ const struct ip6t_reject_info *rejinfo = targinfo;
++
++ if (targinfosize != IP6T_ALIGN(sizeof(struct ip6t_reject_info))) {
++ DEBUGP("REJECTv6: targinfosize %u != 0\n", targinfosize);
++ return 0;
++ }
++
++ /* Only allow these for packet filtering. */
++ if (strcmp(tablename, "filter") != 0) {
++ DEBUGP("REJECTv6: bad table `%s'.\n", tablename);
++ return 0;
++ }
++ if ((hook_mask & ~((1 << NF_IP6_LOCAL_IN)
++ | (1 << NF_IP6_FORWARD)
++ | (1 << NF_IP6_LOCAL_OUT))) != 0) {
++ DEBUGP("REJECTv6: bad hook mask %X\n", hook_mask);
++ return 0;
++ }
++
++ if (rejinfo->with == IP6T_ICMP6_ECHOREPLY) {
++ /* Must specify that it's an ICMP ping packet. */
++ if (e->ipv6.proto != IPPROTO_ICMPV6
++ || (e->ipv6.invflags & IP6T_INV_PROTO)) {
++ DEBUGP("REJECTv6: ECHOREPLY illegal for non-icmp\n");
++ return 0;
++ }
++ /* Must contain ICMP match. */
++ if (IP6T_MATCH_ITERATE(e, find_ping_match) == 0) {
++ DEBUGP("REJECTv6: ECHOREPLY illegal for non-ping\n");
++ return 0;
++ }
++ } else if (rejinfo->with == IP6T_TCP_RESET) {
++ /* Must specify that it's a TCP packet */
++ if (e->ipv6.proto != IPPROTO_TCP
++ || (e->ipv6.invflags & IP6T_INV_PROTO)) {
++ DEBUGP("REJECTv6: TCP_RESET illegal for non-tcp\n");
++ return 0;
++ }
++ }
++
++ return 1;
++}
++
++static struct ip6t_target ip6t_reject_reg
++= { { NULL, NULL }, "REJECT", reject6_target, check, NULL, THIS_MODULE };
++
++static int __init init(void)
++{
++ if (ip6t_register_target(&ip6t_reject_reg))
++ return -EINVAL;
++ return 0;
++}
++
++static void __exit fini(void)
++{
++ ip6t_unregister_target(&ip6t_reject_reg);
++}
++
++module_init(init);
++module_exit(fini);
+Index: linux-2.4.35.4/include/linux/netfilter_ipv6/ip6t_REJECT.h
+===================================================================
+--- linux-2.4.35.4.orig/include/linux/netfilter_ipv6/ip6t_REJECT.h
++++ linux-2.4.35.4/include/linux/netfilter_ipv6/ip6t_REJECT.h
+@@ -2,15 +2,17 @@
+ #define _IP6T_REJECT_H
+
+ enum ip6t_reject_with {
+- IP6T_ICMP_NET_UNREACHABLE,
+- IP6T_ICMP_HOST_UNREACHABLE,
+- IP6T_ICMP_PROT_UNREACHABLE,
+- IP6T_ICMP_PORT_UNREACHABLE,
+- IP6T_ICMP_ECHOREPLY
++ IP6T_ICMP6_NO_ROUTE,
++ IP6T_ICMP6_ADM_PROHIBITED,
++ IP6T_ICMP6_NOT_NEIGHBOUR,
++ IP6T_ICMP6_ADDR_UNREACH,
++ IP6T_ICMP6_PORT_UNREACH,
++ IP6T_ICMP6_ECHOREPLY,
++ IP6T_TCP_RESET
+ };
+
+ struct ip6t_reject_info {
+ enum ip6t_reject_with with; /* reject type */
+ };
+
+-#endif /*_IPT_REJECT_H*/
++#endif /*_IP6T_REJECT_H*/
+Index: linux-2.4.35.4/net/ipv6/netfilter/Makefile
+===================================================================
+--- linux-2.4.35.4.orig/net/ipv6/netfilter/Makefile
++++ linux-2.4.35.4/net/ipv6/netfilter/Makefile
+@@ -34,5 +34,7 @@ obj-$(CONFIG_IP6_NF_QUEUE) += ip6_queue.
+ obj-$(CONFIG_IP6_NF_TARGET_LOG) += ip6t_LOG.o
+ obj-$(CONFIG_IP6_NF_MATCH_RANDOM) += ip6t_random.o
+ obj-$(CONFIG_IP6_NF_MATCH_HL) += ip6t_hl.o
++obj-$(CONFIG_IP6_NF_TARGET_REJECT) += ip6t_REJECT.o
++
+
+ include $(TOPDIR)/Rules.make
+Index: linux-2.4.35.4/net/ipv6/netfilter/Config.in
+===================================================================
+--- linux-2.4.35.4.orig/net/ipv6/netfilter/Config.in
++++ linux-2.4.35.4/net/ipv6/netfilter/Config.in
+@@ -61,6 +61,9 @@ if [ "$CONFIG_IP6_NF_IPTABLES" != "n" ];
+ if [ "$CONFIG_IP6_NF_FILTER" != "n" ]; then
+ dep_tristate ' LOG target support' CONFIG_IP6_NF_TARGET_LOG $CONFIG_IP6_NF_FILTER
+ fi
++ if [ "$CONFIG_IP6_NF_FILTER" != "n" ]; then
++ dep_tristate ' REJECT target support' CONFIG_IP6_NF_TARGET_REJECT $CONFIG_IP6_NF_FILTER
++ fi
+
+ # if [ "$CONFIG_IP6_NF_FILTER" != "n" ]; then
+ # dep_tristate ' REJECT target support' CONFIG_IP6_NF_TARGET_REJECT $CONFIG_IP6_NF_FILTER
--
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