Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
os
linux
1/*
2 * IPv6 specific functions of netfilter core
3 *
4 * Rusty Russell (C) 2000 -- This code is GPL.
5 * Patrick McHardy (C) 2006-2012
6 */
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/netfilter/nf_queue.h>
19
20int ip6_route_me_harder(struct net *net, struct sk_buff *skb)
21{
22 const struct ipv6hdr *iph = ipv6_hdr(skb);
23 struct sock *sk = sk_to_full_sk(skb->sk);
24 unsigned int hh_len;
25 struct dst_entry *dst;
26 struct flowi6 fl6 = {
27 .flowi6_oif = sk && sk->sk_bound_dev_if ? sk->sk_bound_dev_if :
28 rt6_need_strict(&iph->daddr) ? skb_dst(skb)->dev->ifindex : 0,
29 .flowi6_mark = skb->mark,
30 .flowi6_uid = sock_net_uid(net, sk),
31 .daddr = iph->daddr,
32 .saddr = iph->saddr,
33 };
34 int err;
35
36 dst = ip6_route_output(net, sk, &fl6);
37 err = dst->error;
38 if (err) {
39 IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
40 net_dbg_ratelimited("ip6_route_me_harder: No more route\n");
41 dst_release(dst);
42 return err;
43 }
44
45 /* Drop old route. */
46 skb_dst_drop(skb);
47
48 skb_dst_set(skb, dst);
49
50#ifdef CONFIG_XFRM
51 if (!(IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) &&
52 xfrm_decode_session(skb, flowi6_to_flowi(&fl6), AF_INET6) == 0) {
53 skb_dst_set(skb, NULL);
54 dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0);
55 if (IS_ERR(dst))
56 return PTR_ERR(dst);
57 skb_dst_set(skb, dst);
58 }
59#endif
60
61 /* Change in oif may mean change in hh_len. */
62 hh_len = skb_dst(skb)->dev->hard_header_len;
63 if (skb_headroom(skb) < hh_len &&
64 pskb_expand_head(skb, HH_DATA_ALIGN(hh_len - skb_headroom(skb)),
65 0, GFP_ATOMIC))
66 return -ENOMEM;
67
68 return 0;
69}
70EXPORT_SYMBOL(ip6_route_me_harder);
71
72static int nf_ip6_reroute(struct sk_buff *skb,
73 const struct nf_queue_entry *entry)
74{
75 struct ip6_rt_info *rt_info = nf_queue_entry_reroute(entry);
76
77 if (entry->state.hook == NF_INET_LOCAL_OUT) {
78 const struct ipv6hdr *iph = ipv6_hdr(skb);
79 if (!ipv6_addr_equal(&iph->daddr, &rt_info->daddr) ||
80 !ipv6_addr_equal(&iph->saddr, &rt_info->saddr) ||
81 skb->mark != rt_info->mark)
82 return ip6_route_me_harder(entry->state.net, skb);
83 }
84 return 0;
85}
86
87static int nf_ip6_route(struct net *net, struct dst_entry **dst,
88 struct flowi *fl, bool strict)
89{
90 static const struct ipv6_pinfo fake_pinfo;
91 static const struct inet_sock fake_sk = {
92 /* makes ip6_route_output set RT6_LOOKUP_F_IFACE: */
93 .sk.sk_bound_dev_if = 1,
94 .pinet6 = (struct ipv6_pinfo *) &fake_pinfo,
95 };
96 const void *sk = strict ? &fake_sk : NULL;
97 struct dst_entry *result;
98 int err;
99
100 result = ip6_route_output(net, sk, &fl->u.ip6);
101 err = result->error;
102 if (err)
103 dst_release(result);
104 else
105 *dst = result;
106 return err;
107}
108
109static const struct nf_ipv6_ops ipv6ops = {
110 .chk_addr = ipv6_chk_addr,
111 .route_input = ip6_route_input,
112 .fragment = ip6_fragment,
113 .route = nf_ip6_route,
114 .reroute = nf_ip6_reroute,
115};
116
117int __init ipv6_netfilter_init(void)
118{
119 RCU_INIT_POINTER(nf_ipv6_ops, &ipv6ops);
120 return 0;
121}
122
123/* This can be called from inet6_init() on errors, so it cannot
124 * be marked __exit. -DaveM
125 */
126void ipv6_netfilter_fini(void)
127{
128 RCU_INIT_POINTER(nf_ipv6_ops, NULL);
129}