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7#include <linux/kernel.h>
8#include <linux/init.h>
9#include <linux/ipv6.h>
10#include <linux/netfilter.h>
11#include <linux/netfilter_ipv6.h>
12#include <linux/export.h>
13#include <net/addrconf.h>
14#include <net/dst.h>
15#include <net/ipv6.h>
16#include <net/ip6_route.h>
17#include <net/xfrm.h>
18#include <net/ip6_checksum.h>
19#include <net/netfilter/nf_queue.h>
20
21int ip6_route_me_harder(struct sk_buff *skb)
22{
23 struct net *net = dev_net(skb_dst(skb)->dev);
24 const struct ipv6hdr *iph = ipv6_hdr(skb);
25 unsigned int hh_len;
26 struct dst_entry *dst;
27 struct flowi6 fl6 = {
28 .flowi6_oif = skb->sk ? skb->sk->sk_bound_dev_if : 0,
29 .flowi6_mark = skb->mark,
30 .daddr = iph->daddr,
31 .saddr = iph->saddr,
32 };
33
34 dst = ip6_route_output(net, skb->sk, &fl6);
35 if (dst->error) {
36 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
37 LIMIT_NETDEBUG(KERN_DEBUG "ip6_route_me_harder: No more route.\n");
38 dst_release(dst);
39 return dst->error;
40 }
41
42
43 skb_dst_drop(skb);
44
45 skb_dst_set(skb, dst);
46
47#ifdef CONFIG_XFRM
48 if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) &&
49 xfrm_decode_session(skb, flowi6_to_flowi(&fl6), AF_INET6) == 0) {
50 skb_dst_set(skb, NULL);
51 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), skb->sk, 0);
52 if (IS_ERR(dst))
53 return PTR_ERR(dst);
54 skb_dst_set(skb, dst);
55 }
56#endif
57
58
59 hh_len = skb_dst(skb)->dev->hard_header_len;
60 if (skb_headroom(skb) < hh_len &&
61 pskb_expand_head(skb, HH_DATA_ALIGN(hh_len - skb_headroom(skb)),
62 0, GFP_ATOMIC))
63 return -ENOMEM;
64
65 return 0;
66}
67EXPORT_SYMBOL(ip6_route_me_harder);
68
69
70
71
72
73
74struct ip6_rt_info {
75 struct in6_addr daddr;
76 struct in6_addr saddr;
77 u_int32_t mark;
78};
79
80static void nf_ip6_saveroute(const struct sk_buff *skb,
81 struct nf_queue_entry *entry)
82{
83 struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry);
84
85 if (entry->hook == NF_INET_LOCAL_OUT) {
86 const struct ipv6hdr *iph = ipv6_hdr(skb);
87
88 rt_info->daddr = iph->daddr;
89 rt_info->saddr = iph->saddr;
90 rt_info->mark = skb->mark;
91 }
92}
93
94static int nf_ip6_reroute(struct sk_buff *skb,
95 const struct nf_queue_entry *entry)
96{
97 struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry);
98
99 if (entry->hook == NF_INET_LOCAL_OUT) {
100 const struct ipv6hdr *iph = ipv6_hdr(skb);
101 if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) ||
102 !ipv6_addr_equal(&iph->saddr, &rt_info->saddr) ||
103 skb->mark != rt_info->mark)
104 return ip6_route_me_harder(skb);
105 }
106 return 0;
107}
108
109static int nf_ip6_route(struct net *net, struct dst_entry **dst,
110 struct flowi *fl, bool strict)
111{
112 static const struct ipv6_pinfo fake_pinfo;
113 static const struct inet_sock fake_sk = {
114
115 .sk.sk_bound_dev_if = 1,
116 .pinet6 = (struct ipv6_pinfo *) &fake_pinfo,
117 };
118 const void *sk = strict ? &fake_sk : NULL;
119 struct dst_entry *result;
120 int err;
121
122 result = ip6_route_output(net, sk, &fl->u.ip6);
123 err = result->error;
124 if (err)
125 dst_release(result);
126 else
127 *dst = result;
128 return err;
129}
130
131__sum16 nf_ip6_checksum(struct sk_buff *skb, unsigned int hook,
132 unsigned int dataoff, u_int8_t protocol)
133{
134 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
135 __sum16 csum = 0;
136
137 switch (skb->ip_summed) {
138 case CHECKSUM_COMPLETE:
139 if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN)
140 break;
141 if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
142 skb->len - dataoff, protocol,
143 csum_sub(skb->csum,
144 skb_checksum(skb, 0,
145 dataoff, 0)))) {
146 skb->ip_summed = CHECKSUM_UNNECESSARY;
147 break;
148 }
149
150 case CHECKSUM_NONE:
151 skb->csum = ~csum_unfold(
152 csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
153 skb->len - dataoff,
154 protocol,
155 csum_sub(0,
156 skb_checksum(skb, 0,
157 dataoff, 0))));
158 csum = __skb_checksum_complete(skb);
159 }
160 return csum;
161}
162EXPORT_SYMBOL(nf_ip6_checksum);
163
164static __sum16 nf_ip6_checksum_partial(struct sk_buff *skb, unsigned int hook,
165 unsigned int dataoff, unsigned int len,
166 u_int8_t protocol)
167{
168 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
169 __wsum hsum;
170 __sum16 csum = 0;
171
172 switch (skb->ip_summed) {
173 case CHECKSUM_COMPLETE:
174 if (len == skb->len - dataoff)
175 return nf_ip6_checksum(skb, hook, dataoff, protocol);
176
177 case CHECKSUM_NONE:
178 hsum = skb_checksum(skb, 0, dataoff, 0);
179 skb->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr,
180 &ip6h->daddr,
181 skb->len - dataoff,
182 protocol,
183 csum_sub(0, hsum)));
184 skb->ip_summed = CHECKSUM_NONE;
185 return __skb_checksum_complete_head(skb, dataoff + len);
186 }
187 return csum;
188};
189
190static const struct nf_ipv6_ops ipv6ops = {
191 .chk_addr = ipv6_chk_addr,
192};
193
194static const struct nf_afinfo nf_ip6_afinfo = {
195 .family = AF_INET6,
196 .checksum = nf_ip6_checksum,
197 .checksum_partial = nf_ip6_checksum_partial,
198 .route = nf_ip6_route,
199 .saveroute = nf_ip6_saveroute,
200 .reroute = nf_ip6_reroute,
201 .route_key_size = sizeof(struct ip6_rt_info),
202};
203
204int __init ipv6_netfilter_init(void)
205{
206 RCU_INIT_POINTER(nf_ipv6_ops, &ipv6ops);
207 return nf_register_afinfo(&nf_ip6_afinfo);
208}
209
210
211
212
213void ipv6_netfilter_fini(void)
214{
215 RCU_INIT_POINTER(nf_ipv6_ops, NULL);
216 nf_unregister_afinfo(&nf_ip6_afinfo);
217}
218