1#include <linux/kernel.h>
2#include <linux/init.h>
3#include <linux/ipv6.h>
4#include <linux/netfilter.h>
5#include <linux/netfilter_ipv6.h>
6#include <net/dst.h>
7#include <net/ipv6.h>
8#include <net/ip6_route.h>
9#include <net/xfrm.h>
10#include <net/ip6_checksum.h>
11
12int ip6_route_me_harder(struct sk_buff *skb)
13{
14	struct ipv6hdr *iph = ipv6_hdr(skb);
15	struct dst_entry *dst;
16	struct flowi fl = {
17		.oif = skb->sk ? skb->sk->sk_bound_dev_if : 0,
18		.mark = skb->mark,
19		.nl_u =
20		{ .ip6_u =
21		  { .daddr = iph->daddr,
22		    .saddr = iph->saddr, } },
23	};
24
25	dst = ip6_route_output(skb->sk, &fl);
26
27#ifdef CONFIG_XFRM
28	if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) &&
29	    xfrm_decode_session(skb, &fl, AF_INET6) == 0)
30		if (xfrm_lookup(&skb->dst, &fl, skb->sk, 0))
31			return -1;
32#endif
33
34	if (dst->error) {
35		IP6_INC_STATS(ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
36		LIMIT_NETDEBUG(KERN_DEBUG "ip6_route_me_harder: No more route.\n");
37		dst_release(dst);
38		return -EINVAL;
39	}
40
41	/* Drop old route. */
42	dst_release(skb->dst);
43
44	skb->dst = dst;
45	return 0;
46}
47EXPORT_SYMBOL(ip6_route_me_harder);
48
49/*
50 * Extra routing may needed on local out, as the QUEUE target never
51 * returns control to the table.
52 */
53
54struct ip6_rt_info {
55	struct in6_addr daddr;
56	struct in6_addr saddr;
57};
58
59static void nf_ip6_saveroute(const struct sk_buff *skb, struct nf_info *info)
60{
61	struct ip6_rt_info *rt_info = nf_info_reroute(info);
62
63	if (info->hook == NF_IP6_LOCAL_OUT) {
64		struct ipv6hdr *iph = ipv6_hdr(skb);
65
66		rt_info->daddr = iph->daddr;
67		rt_info->saddr = iph->saddr;
68	}
69}
70
71static int nf_ip6_reroute(struct sk_buff **pskb, const struct nf_info *info)
72{
73	struct ip6_rt_info *rt_info = nf_info_reroute(info);
74
75	if (info->hook == NF_IP6_LOCAL_OUT) {
76		struct ipv6hdr *iph = ipv6_hdr(*pskb);
77		if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) ||
78		    !ipv6_addr_equal(&iph->saddr, &rt_info->saddr))
79			return ip6_route_me_harder(*pskb);
80	}
81	return 0;
82}
83
84__sum16 nf_ip6_checksum(struct sk_buff *skb, unsigned int hook,
85			     unsigned int dataoff, u_int8_t protocol)
86{
87	struct ipv6hdr *ip6h = ipv6_hdr(skb);
88	__sum16 csum = 0;
89
90	switch (skb->ip_summed) {
91	case CHECKSUM_COMPLETE:
92		if (hook != NF_IP6_PRE_ROUTING && hook != NF_IP6_LOCAL_IN)
93			break;
94		if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
95				     skb->len - dataoff, protocol,
96				     csum_sub(skb->csum,
97					      skb_checksum(skb, 0,
98							   dataoff, 0)))) {
99			skb->ip_summed = CHECKSUM_UNNECESSARY;
100			break;
101		}
102		/* fall through */
103	case CHECKSUM_NONE:
104		skb->csum = ~csum_unfold(
105				csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
106					     skb->len - dataoff,
107					     protocol,
108					     csum_sub(0,
109						      skb_checksum(skb, 0,
110								   dataoff, 0))));
111		csum = __skb_checksum_complete(skb);
112	}
113	return csum;
114}
115
116EXPORT_SYMBOL(nf_ip6_checksum);
117
118static struct nf_afinfo nf_ip6_afinfo = {
119	.family		= AF_INET6,
120	.checksum	= nf_ip6_checksum,
121	.saveroute	= nf_ip6_saveroute,
122	.reroute	= nf_ip6_reroute,
123	.route_key_size	= sizeof(struct ip6_rt_info),
124};
125
126int __init ipv6_netfilter_init(void)
127{
128	return nf_register_afinfo(&nf_ip6_afinfo);
129}
130
131/* This can be called from inet6_init() on errors, so it cannot
132 * be marked __exit. -DaveM
133 */
134void ipv6_netfilter_fini(void)
135{
136	nf_unregister_afinfo(&nf_ip6_afinfo);
137}
138