path: root/target/linux/generic-2.4/patches/624-netfilter_ip6t_reject.patch

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