Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
[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 #include <net/netfilter/nf_queue.h>
12
13 int ip6_route_me_harder(struct sk_buff *skb)
14 {
15         struct net *net = dev_net(skb->dst->dev);
16         struct ipv6hdr *iph = ipv6_hdr(skb);
17         struct dst_entry *dst;
18         struct flowi fl = {
19                 .oif = skb->sk ? skb->sk->sk_bound_dev_if : 0,
20                 .mark = skb->mark,
21                 .nl_u =
22                 { .ip6_u =
23                   { .daddr = iph->daddr,
24                     .saddr = iph->saddr, } },
25         };
26
27         dst = ip6_route_output(net, skb->sk, &fl);
28
29 #ifdef CONFIG_XFRM
30         if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) &&
31             xfrm_decode_session(skb, &fl, AF_INET6) == 0)
32                 if (xfrm_lookup(net, &skb->dst, &fl, skb->sk, 0))
33                         return -1;
34 #endif
35
36         if (dst->error) {
37                 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
38                 LIMIT_NETDEBUG(KERN_DEBUG "ip6_route_me_harder: No more route.\n");
39                 dst_release(dst);
40                 return -EINVAL;
41         }
42
43         /* Drop old route. */
44         dst_release(skb->dst);
45
46         skb->dst = dst;
47         return 0;
48 }
49 EXPORT_SYMBOL(ip6_route_me_harder);
50
51 /*
52  * Extra routing may needed on local out, as the QUEUE target never
53  * returns control to the table.
54  */
55
56 struct ip6_rt_info {
57         struct in6_addr daddr;
58         struct in6_addr saddr;
59         u_int32_t mark;
60 };
61
62 static void nf_ip6_saveroute(const struct sk_buff *skb,
63                              struct nf_queue_entry *entry)
64 {
65         struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry);
66
67         if (entry->hook == NF_INET_LOCAL_OUT) {
68                 struct ipv6hdr *iph = ipv6_hdr(skb);
69
70                 rt_info->daddr = iph->daddr;
71                 rt_info->saddr = iph->saddr;
72                 rt_info->mark = skb->mark;
73         }
74 }
75
76 static int nf_ip6_reroute(struct sk_buff *skb,
77                           const struct nf_queue_entry *entry)
78 {
79         struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry);
80
81         if (entry->hook == NF_INET_LOCAL_OUT) {
82                 struct ipv6hdr *iph = ipv6_hdr(skb);
83                 if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) ||
84                     !ipv6_addr_equal(&iph->saddr, &rt_info->saddr) ||
85                     skb->mark != rt_info->mark)
86                         return ip6_route_me_harder(skb);
87         }
88         return 0;
89 }
90
91 static int nf_ip6_route(struct dst_entry **dst, struct flowi *fl)
92 {
93         *dst = ip6_route_output(&init_net, NULL, fl);
94         return (*dst)->error;
95 }
96
97 __sum16 nf_ip6_checksum(struct sk_buff *skb, unsigned int hook,
98                              unsigned int dataoff, u_int8_t protocol)
99 {
100         struct ipv6hdr *ip6h = ipv6_hdr(skb);
101         __sum16 csum = 0;
102
103         switch (skb->ip_summed) {
104         case CHECKSUM_COMPLETE:
105                 if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN)
106                         break;
107                 if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
108                                      skb->len - dataoff, protocol,
109                                      csum_sub(skb->csum,
110                                               skb_checksum(skb, 0,
111                                                            dataoff, 0)))) {
112                         skb->ip_summed = CHECKSUM_UNNECESSARY;
113                         break;
114                 }
115                 /* fall through */
116         case CHECKSUM_NONE:
117                 skb->csum = ~csum_unfold(
118                                 csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
119                                              skb->len - dataoff,
120                                              protocol,
121                                              csum_sub(0,
122                                                       skb_checksum(skb, 0,
123                                                                    dataoff, 0))));
124                 csum = __skb_checksum_complete(skb);
125         }
126         return csum;
127 }
128 EXPORT_SYMBOL(nf_ip6_checksum);
129
130 static __sum16 nf_ip6_checksum_partial(struct sk_buff *skb, unsigned int hook,
131                                        unsigned int dataoff, unsigned int len,
132                                        u_int8_t protocol)
133 {
134         struct ipv6hdr *ip6h = ipv6_hdr(skb);
135         __wsum hsum;
136         __sum16 csum = 0;
137
138         switch (skb->ip_summed) {
139         case CHECKSUM_COMPLETE:
140                 if (len == skb->len - dataoff)
141                         return nf_ip6_checksum(skb, hook, dataoff, protocol);
142                 /* fall through */
143         case CHECKSUM_NONE:
144                 hsum = skb_checksum(skb, 0, dataoff, 0);
145                 skb->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr,
146                                                          &ip6h->daddr,
147                                                          skb->len - dataoff,
148                                                          protocol,
149                                                          csum_sub(0, hsum)));
150                 skb->ip_summed = CHECKSUM_NONE;
151                 csum = __skb_checksum_complete_head(skb, dataoff + len);
152                 if (!csum)
153                         skb->ip_summed = CHECKSUM_UNNECESSARY;
154         }
155         return csum;
156 };
157
158 static const struct nf_afinfo nf_ip6_afinfo = {
159         .family                 = AF_INET6,
160         .checksum               = nf_ip6_checksum,
161         .checksum_partial       = nf_ip6_checksum_partial,
162         .route                  = nf_ip6_route,
163         .saveroute              = nf_ip6_saveroute,
164         .reroute                = nf_ip6_reroute,
165         .route_key_size         = sizeof(struct ip6_rt_info),
166 };
167
168 int __init ipv6_netfilter_init(void)
169 {
170         return nf_register_afinfo(&nf_ip6_afinfo);
171 }
172
173 /* This can be called from inet6_init() on errors, so it cannot
174  * be marked __exit. -DaveM
175  */
176 void ipv6_netfilter_fini(void)
177 {
178         nf_unregister_afinfo(&nf_ip6_afinfo);
179 }