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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(skb)->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 | if (dst->error) { | |
29 | IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); | |
30 | LIMIT_NETDEBUG(KERN_DEBUG "ip6_route_me_harder: No more route.\n"); | |
31 | dst_release(dst); | |
32 | return -EINVAL; | |
33 | } | |
34 | ||
35 | /* Drop old route. */ | |
36 | skb_dst_drop(skb); | |
37 | ||
38 | skb_dst_set(skb, dst); | |
39 | ||
40 | #ifdef CONFIG_XFRM | |
41 | if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) && | |
42 | xfrm_decode_session(skb, &fl, AF_INET6) == 0) { | |
43 | skb_dst_set(skb, NULL); | |
44 | if (xfrm_lookup(net, &dst, &fl, skb->sk, 0)) | |
45 | return -1; | |
46 | skb_dst_set(skb, dst); | |
47 | } | |
48 | #endif | |
49 | ||
50 | return 0; | |
51 | } | |
52 | EXPORT_SYMBOL(ip6_route_me_harder); | |
53 | ||
54 | /* | |
55 | * Extra routing may needed on local out, as the QUEUE target never | |
56 | * returns control to the table. | |
57 | */ | |
58 | ||
59 | struct ip6_rt_info { | |
60 | struct in6_addr daddr; | |
61 | struct in6_addr saddr; | |
62 | u_int32_t mark; | |
63 | }; | |
64 | ||
65 | static void nf_ip6_saveroute(const struct sk_buff *skb, | |
66 | struct nf_queue_entry *entry) | |
67 | { | |
68 | struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry); | |
69 | ||
70 | if (entry->hook == NF_INET_LOCAL_OUT) { | |
71 | struct ipv6hdr *iph = ipv6_hdr(skb); | |
72 | ||
73 | rt_info->daddr = iph->daddr; | |
74 | rt_info->saddr = iph->saddr; | |
75 | rt_info->mark = skb->mark; | |
76 | } | |
77 | } | |
78 | ||
79 | static int nf_ip6_reroute(struct sk_buff *skb, | |
80 | const struct nf_queue_entry *entry) | |
81 | { | |
82 | struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry); | |
83 | ||
84 | if (entry->hook == NF_INET_LOCAL_OUT) { | |
85 | struct ipv6hdr *iph = ipv6_hdr(skb); | |
86 | if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) || | |
87 | !ipv6_addr_equal(&iph->saddr, &rt_info->saddr) || | |
88 | skb->mark != rt_info->mark) | |
89 | return ip6_route_me_harder(skb); | |
90 | } | |
91 | return 0; | |
92 | } | |
93 | ||
94 | static int nf_ip6_route(struct dst_entry **dst, struct flowi *fl) | |
95 | { | |
96 | *dst = ip6_route_output(&init_net, NULL, fl); | |
97 | return (*dst)->error; | |
98 | } | |
99 | ||
100 | __sum16 nf_ip6_checksum(struct sk_buff *skb, unsigned int hook, | |
101 | unsigned int dataoff, u_int8_t protocol) | |
102 | { | |
103 | struct ipv6hdr *ip6h = ipv6_hdr(skb); | |
104 | __sum16 csum = 0; | |
105 | ||
106 | switch (skb->ip_summed) { | |
107 | case CHECKSUM_COMPLETE: | |
108 | if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN) | |
109 | break; | |
110 | if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, | |
111 | skb->len - dataoff, protocol, | |
112 | csum_sub(skb->csum, | |
113 | skb_checksum(skb, 0, | |
114 | dataoff, 0)))) { | |
115 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
116 | break; | |
117 | } | |
118 | /* fall through */ | |
119 | case CHECKSUM_NONE: | |
120 | skb->csum = ~csum_unfold( | |
121 | csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, | |
122 | skb->len - dataoff, | |
123 | protocol, | |
124 | csum_sub(0, | |
125 | skb_checksum(skb, 0, | |
126 | dataoff, 0)))); | |
127 | csum = __skb_checksum_complete(skb); | |
128 | } | |
129 | return csum; | |
130 | } | |
131 | EXPORT_SYMBOL(nf_ip6_checksum); | |
132 | ||
133 | static __sum16 nf_ip6_checksum_partial(struct sk_buff *skb, unsigned int hook, | |
134 | unsigned int dataoff, unsigned int len, | |
135 | u_int8_t protocol) | |
136 | { | |
137 | struct ipv6hdr *ip6h = ipv6_hdr(skb); | |
138 | __wsum hsum; | |
139 | __sum16 csum = 0; | |
140 | ||
141 | switch (skb->ip_summed) { | |
142 | case CHECKSUM_COMPLETE: | |
143 | if (len == skb->len - dataoff) | |
144 | return nf_ip6_checksum(skb, hook, dataoff, protocol); | |
145 | /* fall through */ | |
146 | case CHECKSUM_NONE: | |
147 | hsum = skb_checksum(skb, 0, dataoff, 0); | |
148 | skb->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr, | |
149 | &ip6h->daddr, | |
150 | skb->len - dataoff, | |
151 | protocol, | |
152 | csum_sub(0, hsum))); | |
153 | skb->ip_summed = CHECKSUM_NONE; | |
154 | return __skb_checksum_complete_head(skb, dataoff + len); | |
155 | } | |
156 | return csum; | |
157 | }; | |
158 | ||
159 | static const struct nf_afinfo nf_ip6_afinfo = { | |
160 | .family = AF_INET6, | |
161 | .checksum = nf_ip6_checksum, | |
162 | .checksum_partial = nf_ip6_checksum_partial, | |
163 | .route = nf_ip6_route, | |
164 | .saveroute = nf_ip6_saveroute, | |
165 | .reroute = nf_ip6_reroute, | |
166 | .route_key_size = sizeof(struct ip6_rt_info), | |
167 | }; | |
168 | ||
169 | int __init ipv6_netfilter_init(void) | |
170 | { | |
171 | return nf_register_afinfo(&nf_ip6_afinfo); | |
172 | } | |
173 | ||
174 | /* This can be called from inet6_init() on errors, so it cannot | |
175 | * be marked __exit. -DaveM | |
176 | */ | |
177 | void ipv6_netfilter_fini(void) | |
178 | { | |
179 | nf_unregister_afinfo(&nf_ip6_afinfo); | |
180 | } |