148 lines
3.4 KiB
C
148 lines
3.4 KiB
C
#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/ipv6.h>
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#include <linux/netfilter.h>
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#include <linux/netfilter_ipv6.h>
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#include <net/dst.h>
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#include <net/ipv6.h>
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#include <net/ip6_route.h>
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#include <net/xfrm.h>
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#include <net/ip6_checksum.h>
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#include <net/netfilter/nf_queue.h>
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int ip6_route_me_harder(struct sk_buff *skb)
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{
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struct ipv6hdr *iph = ipv6_hdr(skb);
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struct dst_entry *dst;
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struct flowi fl = {
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.oif = skb->sk ? skb->sk->sk_bound_dev_if : 0,
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.mark = skb->mark,
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.nl_u =
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{ .ip6_u =
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{ .daddr = iph->daddr,
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.saddr = iph->saddr, } },
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};
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dst = ip6_route_output(skb->sk, &fl);
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#ifdef CONFIG_XFRM
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if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) &&
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xfrm_decode_session(skb, &fl, AF_INET6) == 0)
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if (xfrm_lookup(&skb->dst, &fl, skb->sk, 0))
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return -1;
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#endif
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if (dst->error) {
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IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
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LIMIT_NETDEBUG(KERN_DEBUG "ip6_route_me_harder: No more route.\n");
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dst_release(dst);
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return -EINVAL;
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}
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/* Drop old route. */
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dst_release(skb->dst);
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skb->dst = dst;
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return 0;
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}
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EXPORT_SYMBOL(ip6_route_me_harder);
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/*
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* Extra routing may needed on local out, as the QUEUE target never
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* returns control to the table.
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*/
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struct ip6_rt_info {
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struct in6_addr daddr;
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struct in6_addr saddr;
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};
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static void nf_ip6_saveroute(const struct sk_buff *skb,
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struct nf_queue_entry *entry)
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{
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struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry);
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if (entry->hook == NF_INET_LOCAL_OUT) {
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struct ipv6hdr *iph = ipv6_hdr(skb);
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rt_info->daddr = iph->daddr;
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rt_info->saddr = iph->saddr;
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}
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}
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static int nf_ip6_reroute(struct sk_buff *skb,
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const struct nf_queue_entry *entry)
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{
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struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry);
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if (entry->hook == NF_INET_LOCAL_OUT) {
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struct ipv6hdr *iph = ipv6_hdr(skb);
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if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) ||
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!ipv6_addr_equal(&iph->saddr, &rt_info->saddr))
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return ip6_route_me_harder(skb);
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}
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return 0;
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}
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static int nf_ip6_route(struct dst_entry **dst, struct flowi *fl)
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{
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*dst = ip6_route_output(NULL, fl);
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return (*dst)->error;
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}
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__sum16 nf_ip6_checksum(struct sk_buff *skb, unsigned int hook,
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unsigned int dataoff, u_int8_t protocol)
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{
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struct ipv6hdr *ip6h = ipv6_hdr(skb);
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__sum16 csum = 0;
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switch (skb->ip_summed) {
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case CHECKSUM_COMPLETE:
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if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN)
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break;
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if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
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skb->len - dataoff, protocol,
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csum_sub(skb->csum,
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skb_checksum(skb, 0,
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dataoff, 0)))) {
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skb->ip_summed = CHECKSUM_UNNECESSARY;
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break;
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}
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/* fall through */
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case CHECKSUM_NONE:
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skb->csum = ~csum_unfold(
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csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
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skb->len - dataoff,
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protocol,
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csum_sub(0,
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skb_checksum(skb, 0,
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dataoff, 0))));
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csum = __skb_checksum_complete(skb);
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}
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return csum;
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}
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EXPORT_SYMBOL(nf_ip6_checksum);
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static const struct nf_afinfo nf_ip6_afinfo = {
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.family = AF_INET6,
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.checksum = nf_ip6_checksum,
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.route = nf_ip6_route,
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.saveroute = nf_ip6_saveroute,
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.reroute = nf_ip6_reroute,
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.route_key_size = sizeof(struct ip6_rt_info),
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};
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int __init ipv6_netfilter_init(void)
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{
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return nf_register_afinfo(&nf_ip6_afinfo);
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}
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/* This can be called from inet6_init() on errors, so it cannot
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* be marked __exit. -DaveM
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*/
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void ipv6_netfilter_fini(void)
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{
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nf_unregister_afinfo(&nf_ip6_afinfo);
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}
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