2 * IPv6 specific functions of netfilter core
4 * Rusty Russell (C) 2000 -- This code is GPL.
5 * Patrick McHardy (C) 2006-2012
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>
16 #include <net/ip6_route.h>
18 #include <net/ip6_checksum.h>
19 #include <net/netfilter/nf_queue.h>
21 int ip6_route_me_harder(struct sk_buff *skb)
23 struct net *net = dev_net(skb_dst(skb)->dev);
24 const struct ipv6hdr *iph = ipv6_hdr(skb);
26 struct dst_entry *dst;
28 .flowi6_oif = skb->sk ? skb->sk->sk_bound_dev_if : 0,
29 .flowi6_mark = skb->mark,
35 dst = ip6_route_output(net, skb->sk, &fl6);
38 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
39 net_dbg_ratelimited("ip6_route_me_harder: No more route\n");
47 skb_dst_set(skb, dst);
50 if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) &&
51 xfrm_decode_session(skb, flowi6_to_flowi(&fl6), AF_INET6) == 0) {
52 skb_dst_set(skb, NULL);
53 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), skb->sk, 0);
56 skb_dst_set(skb, dst);
60 /* Change in oif may mean change in hh_len. */
61 hh_len = skb_dst(skb)->dev->hard_header_len;
62 if (skb_headroom(skb) < hh_len &&
63 pskb_expand_head(skb, HH_DATA_ALIGN(hh_len - skb_headroom(skb)),
69 EXPORT_SYMBOL(ip6_route_me_harder);
72 * Extra routing may needed on local out, as the QUEUE target never
73 * returns control to the table.
77 struct in6_addr daddr;
78 struct in6_addr saddr;
82 static void nf_ip6_saveroute(const struct sk_buff *skb,
83 struct nf_queue_entry *entry)
85 struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry);
87 if (entry->state.hook == NF_INET_LOCAL_OUT) {
88 const struct ipv6hdr *iph = ipv6_hdr(skb);
90 rt_info->daddr = iph->daddr;
91 rt_info->saddr = iph->saddr;
92 rt_info->mark = skb->mark;
96 static int nf_ip6_reroute(struct sk_buff *skb,
97 const struct nf_queue_entry *entry)
99 struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry);
101 if (entry->state.hook == NF_INET_LOCAL_OUT) {
102 const struct ipv6hdr *iph = ipv6_hdr(skb);
103 if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) ||
104 !ipv6_addr_equal(&iph->saddr, &rt_info->saddr) ||
105 skb->mark != rt_info->mark)
106 return ip6_route_me_harder(skb);
111 static int nf_ip6_route(struct net *net, struct dst_entry **dst,
112 struct flowi *fl, bool strict)
114 static const struct ipv6_pinfo fake_pinfo;
115 static const struct inet_sock fake_sk = {
116 /* makes ip6_route_output set RT6_LOOKUP_F_IFACE: */
117 .sk.sk_bound_dev_if = 1,
118 .pinet6 = (struct ipv6_pinfo *) &fake_pinfo,
120 const void *sk = strict ? &fake_sk : NULL;
121 struct dst_entry *result;
124 result = ip6_route_output(net, sk, &fl->u.ip6);
133 __sum16 nf_ip6_checksum(struct sk_buff *skb, unsigned int hook,
134 unsigned int dataoff, u_int8_t protocol)
136 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
139 switch (skb->ip_summed) {
140 case CHECKSUM_COMPLETE:
141 if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN)
143 if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
144 skb->len - dataoff, protocol,
148 skb->ip_summed = CHECKSUM_UNNECESSARY;
153 skb->csum = ~csum_unfold(
154 csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
160 csum = __skb_checksum_complete(skb);
164 EXPORT_SYMBOL(nf_ip6_checksum);
166 static __sum16 nf_ip6_checksum_partial(struct sk_buff *skb, unsigned int hook,
167 unsigned int dataoff, unsigned int len,
170 const struct ipv6hdr *ip6h = ipv6_hdr(skb);
174 switch (skb->ip_summed) {
175 case CHECKSUM_COMPLETE:
176 if (len == skb->len - dataoff)
177 return nf_ip6_checksum(skb, hook, dataoff, protocol);
180 hsum = skb_checksum(skb, 0, dataoff, 0);
181 skb->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr,
186 skb->ip_summed = CHECKSUM_NONE;
187 return __skb_checksum_complete_head(skb, dataoff + len);
192 static const struct nf_ipv6_ops ipv6ops = {
193 .chk_addr = ipv6_chk_addr,
194 .route_input = ip6_route_input,
195 .fragment = ip6_fragment
198 static const struct nf_afinfo nf_ip6_afinfo = {
200 .checksum = nf_ip6_checksum,
201 .checksum_partial = nf_ip6_checksum_partial,
202 .route = nf_ip6_route,
203 .saveroute = nf_ip6_saveroute,
204 .reroute = nf_ip6_reroute,
205 .route_key_size = sizeof(struct ip6_rt_info),
208 int __init ipv6_netfilter_init(void)
210 RCU_INIT_POINTER(nf_ipv6_ops, &ipv6ops);
211 return nf_register_afinfo(&nf_ip6_afinfo);
214 /* This can be called from inet6_init() on errors, so it cannot
215 * be marked __exit. -DaveM
217 void ipv6_netfilter_fini(void)
219 RCU_INIT_POINTER(nf_ipv6_ops, NULL);
220 nf_unregister_afinfo(&nf_ip6_afinfo);