Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid
[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(&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 };
60
61 static void nf_ip6_saveroute(const struct sk_buff *skb,
62                              struct nf_queue_entry *entry)
63 {
64         struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry);
65
66         if (entry->hook == NF_INET_LOCAL_OUT) {
67                 struct ipv6hdr *iph = ipv6_hdr(skb);
68
69                 rt_info->daddr = iph->daddr;
70                 rt_info->saddr = iph->saddr;
71         }
72 }
73
74 static int nf_ip6_reroute(struct sk_buff *skb,
75                           const struct nf_queue_entry *entry)
76 {
77         struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry);
78
79         if (entry->hook == NF_INET_LOCAL_OUT) {
80                 struct ipv6hdr *iph = ipv6_hdr(skb);
81                 if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) ||
82                     !ipv6_addr_equal(&iph->saddr, &rt_info->saddr))
83                         return ip6_route_me_harder(skb);
84         }
85         return 0;
86 }
87
88 static int nf_ip6_route(struct dst_entry **dst, struct flowi *fl)
89 {
90         *dst = ip6_route_output(&init_net, NULL, fl);
91         return (*dst)->error;
92 }
93
94 __sum16 nf_ip6_checksum(struct sk_buff *skb, unsigned int hook,
95                              unsigned int dataoff, u_int8_t protocol)
96 {
97         struct ipv6hdr *ip6h = ipv6_hdr(skb);
98         __sum16 csum = 0;
99
100         switch (skb->ip_summed) {
101         case CHECKSUM_COMPLETE:
102                 if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN)
103                         break;
104                 if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
105                                      skb->len - dataoff, protocol,
106                                      csum_sub(skb->csum,
107                                               skb_checksum(skb, 0,
108                                                            dataoff, 0)))) {
109                         skb->ip_summed = CHECKSUM_UNNECESSARY;
110                         break;
111                 }
112                 /* fall through */
113         case CHECKSUM_NONE:
114                 skb->csum = ~csum_unfold(
115                                 csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
116                                              skb->len - dataoff,
117                                              protocol,
118                                              csum_sub(0,
119                                                       skb_checksum(skb, 0,
120                                                                    dataoff, 0))));
121                 csum = __skb_checksum_complete(skb);
122         }
123         return csum;
124 }
125 EXPORT_SYMBOL(nf_ip6_checksum);
126
127 static __sum16 nf_ip6_checksum_partial(struct sk_buff *skb, unsigned int hook,
128                                        unsigned int dataoff, unsigned int len,
129                                        u_int8_t protocol)
130 {
131         struct ipv6hdr *ip6h = ipv6_hdr(skb);
132         __wsum hsum;
133         __sum16 csum = 0;
134
135         switch (skb->ip_summed) {
136         case CHECKSUM_COMPLETE:
137                 if (len == skb->len - dataoff)
138                         return nf_ip6_checksum(skb, hook, dataoff, protocol);
139                 /* fall through */
140         case CHECKSUM_NONE:
141                 hsum = skb_checksum(skb, 0, dataoff, 0);
142                 skb->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr,
143                                                          &ip6h->daddr,
144                                                          skb->len - dataoff,
145                                                          protocol,
146                                                          csum_sub(0, hsum)));
147                 skb->ip_summed = CHECKSUM_NONE;
148                 csum = __skb_checksum_complete_head(skb, dataoff + len);
149                 if (!csum)
150                         skb->ip_summed = CHECKSUM_UNNECESSARY;
151         }
152         return csum;
153 };
154
155 static const struct nf_afinfo nf_ip6_afinfo = {
156         .family                 = AF_INET6,
157         .checksum               = nf_ip6_checksum,
158         .checksum_partial       = nf_ip6_checksum_partial,
159         .route                  = nf_ip6_route,
160         .saveroute              = nf_ip6_saveroute,
161         .reroute                = nf_ip6_reroute,
162         .route_key_size         = sizeof(struct ip6_rt_info),
163 };
164
165 int __init ipv6_netfilter_init(void)
166 {
167         return nf_register_afinfo(&nf_ip6_afinfo);
168 }
169
170 /* This can be called from inet6_init() on errors, so it cannot
171  * be marked __exit. -DaveM
172  */
173 void ipv6_netfilter_fini(void)
174 {
175         nf_unregister_afinfo(&nf_ip6_afinfo);
176 }