Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux...
[linux-2.6] / net / ipv6 / netfilter.c
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
12 int 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 }
47 EXPORT_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
54 struct ip6_rt_info {
55         struct in6_addr daddr;
56         struct in6_addr saddr;
57 };
58
59 static 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
71 static int nf_ip6_reroute(struct sk_buff *skb, 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(skb);
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(skb);
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
116 EXPORT_SYMBOL(nf_ip6_checksum);
117
118 static 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
126 int __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  */
134 void ipv6_netfilter_fini(void)
135 {
136         nf_unregister_afinfo(&nf_ip6_afinfo);
137 }