[kernel] generic-2.4: add ip6t_REJECT support

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@10482 3c298f89-4303-0410-b956-a3cf2f4a3e73
master
Gabor Juhos 2008-02-18 08:03:28 +00:00
parent 29767435d3
commit 2aa7e0c97e
2 changed files with 361 additions and 0 deletions

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@ -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

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@ -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