1 /* IPv6-specific defines for netfilter.
2  * (C)1998 Rusty Russell -- This code is GPL.
3  * (C)1999 David Jeffery
4  *   this header was blatantly ripped from netfilter_ipv4.h
5  *   it's amazing what adding a bunch of 6s can do =8^)
6  */
7 #ifndef __LINUX_IP6_NETFILTER_H
8 #define __LINUX_IP6_NETFILTER_H
9 
10 #include <uapi/linux/netfilter_ipv6.h>
11 #include <net/tcp.h>
12 
13 /* Check for an extension */
14 static inline int
nf_ip6_ext_hdr(u8 nexthdr)15 nf_ip6_ext_hdr(u8 nexthdr)
16 {	return (nexthdr == IPPROTO_HOPOPTS) ||
17 	       (nexthdr == IPPROTO_ROUTING) ||
18 	       (nexthdr == IPPROTO_FRAGMENT) ||
19 	       (nexthdr == IPPROTO_ESP) ||
20 	       (nexthdr == IPPROTO_AH) ||
21 	       (nexthdr == IPPROTO_NONE) ||
22 	       (nexthdr == IPPROTO_DSTOPTS);
23 }
24 
25 /* Extra routing may needed on local out, as the QUEUE target never returns
26  * control to the table.
27  */
28 struct ip6_rt_info {
29 	struct in6_addr daddr;
30 	struct in6_addr saddr;
31 	u_int32_t mark;
32 };
33 
34 struct nf_queue_entry;
35 struct nf_bridge_frag_data;
36 
37 /*
38  * Hook functions for ipv6 to allow xt_* modules to be built-in even
39  * if IPv6 is a module.
40  */
41 struct nf_ipv6_ops {
42 #if IS_MODULE(CONFIG_IPV6)
43 	int (*chk_addr)(struct net *net, const struct in6_addr *addr,
44 			const struct net_device *dev, int strict);
45 	int (*route_me_harder)(struct net *net, struct sock *sk, struct sk_buff *skb);
46 	int (*dev_get_saddr)(struct net *net, const struct net_device *dev,
47 		       const struct in6_addr *daddr, unsigned int srcprefs,
48 		       struct in6_addr *saddr);
49 	int (*route)(struct net *net, struct dst_entry **dst, struct flowi *fl,
50 		     bool strict);
51 	u32 (*cookie_init_sequence)(const struct ipv6hdr *iph,
52 				    const struct tcphdr *th, u16 *mssp);
53 	int (*cookie_v6_check)(const struct ipv6hdr *iph,
54 			       const struct tcphdr *th, __u32 cookie);
55 #endif
56 	void (*route_input)(struct sk_buff *skb);
57 	int (*fragment)(struct net *net, struct sock *sk, struct sk_buff *skb,
58 			int (*output)(struct net *, struct sock *, struct sk_buff *));
59 	int (*reroute)(struct sk_buff *skb, const struct nf_queue_entry *entry);
60 #if IS_MODULE(CONFIG_IPV6)
61 	int (*br_fragment)(struct net *net, struct sock *sk,
62 			   struct sk_buff *skb,
63 			   struct nf_bridge_frag_data *data,
64 			   int (*output)(struct net *, struct sock *sk,
65 					 const struct nf_bridge_frag_data *data,
66 					 struct sk_buff *));
67 #endif
68 };
69 
70 #ifdef CONFIG_NETFILTER
71 #include <net/addrconf.h>
72 
73 extern const struct nf_ipv6_ops __rcu *nf_ipv6_ops;
nf_get_ipv6_ops(void)74 static inline const struct nf_ipv6_ops *nf_get_ipv6_ops(void)
75 {
76 	return rcu_dereference(nf_ipv6_ops);
77 }
78 
nf_ipv6_chk_addr(struct net * net,const struct in6_addr * addr,const struct net_device * dev,int strict)79 static inline int nf_ipv6_chk_addr(struct net *net, const struct in6_addr *addr,
80 				   const struct net_device *dev, int strict)
81 {
82 #if IS_MODULE(CONFIG_IPV6)
83 	const struct nf_ipv6_ops *v6_ops = nf_get_ipv6_ops();
84 
85 	if (!v6_ops)
86 		return 1;
87 
88 	return v6_ops->chk_addr(net, addr, dev, strict);
89 #elif IS_BUILTIN(CONFIG_IPV6)
90 	return ipv6_chk_addr(net, addr, dev, strict);
91 #else
92 	return 1;
93 #endif
94 }
95 
96 int __nf_ip6_route(struct net *net, struct dst_entry **dst,
97 			       struct flowi *fl, bool strict);
98 
nf_ip6_route(struct net * net,struct dst_entry ** dst,struct flowi * fl,bool strict)99 static inline int nf_ip6_route(struct net *net, struct dst_entry **dst,
100 			       struct flowi *fl, bool strict)
101 {
102 #if IS_MODULE(CONFIG_IPV6)
103 	const struct nf_ipv6_ops *v6ops = nf_get_ipv6_ops();
104 
105 	if (v6ops)
106 		return v6ops->route(net, dst, fl, strict);
107 
108 	return -EHOSTUNREACH;
109 #endif
110 #if IS_BUILTIN(CONFIG_IPV6)
111 	return __nf_ip6_route(net, dst, fl, strict);
112 #else
113 	return -EHOSTUNREACH;
114 #endif
115 }
116 
117 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
118 
119 int br_ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
120 		    struct nf_bridge_frag_data *data,
121 		    int (*output)(struct net *, struct sock *sk,
122 				  const struct nf_bridge_frag_data *data,
123 				  struct sk_buff *));
124 
nf_br_ip6_fragment(struct net * net,struct sock * sk,struct sk_buff * skb,struct nf_bridge_frag_data * data,int (* output)(struct net *,struct sock * sk,const struct nf_bridge_frag_data * data,struct sk_buff *))125 static inline int nf_br_ip6_fragment(struct net *net, struct sock *sk,
126 				     struct sk_buff *skb,
127 				     struct nf_bridge_frag_data *data,
128 				     int (*output)(struct net *, struct sock *sk,
129 						   const struct nf_bridge_frag_data *data,
130 						   struct sk_buff *))
131 {
132 #if IS_MODULE(CONFIG_IPV6)
133 	const struct nf_ipv6_ops *v6_ops = nf_get_ipv6_ops();
134 
135 	if (!v6_ops)
136 		return 1;
137 
138 	return v6_ops->br_fragment(net, sk, skb, data, output);
139 #elif IS_BUILTIN(CONFIG_IPV6)
140 	return br_ip6_fragment(net, sk, skb, data, output);
141 #else
142 	return 1;
143 #endif
144 }
145 
146 int ip6_route_me_harder(struct net *net, struct sock *sk, struct sk_buff *skb);
147 
nf_ip6_route_me_harder(struct net * net,struct sock * sk,struct sk_buff * skb)148 static inline int nf_ip6_route_me_harder(struct net *net, struct sock *sk, struct sk_buff *skb)
149 {
150 #if IS_MODULE(CONFIG_IPV6)
151 	const struct nf_ipv6_ops *v6_ops = nf_get_ipv6_ops();
152 
153 	if (!v6_ops)
154 		return -EHOSTUNREACH;
155 
156 	return v6_ops->route_me_harder(net, sk, skb);
157 #elif IS_BUILTIN(CONFIG_IPV6)
158 	return ip6_route_me_harder(net, sk, skb);
159 #else
160 	return -EHOSTUNREACH;
161 #endif
162 }
163 
nf_ipv6_cookie_init_sequence(const struct ipv6hdr * iph,const struct tcphdr * th,u16 * mssp)164 static inline u32 nf_ipv6_cookie_init_sequence(const struct ipv6hdr *iph,
165 					       const struct tcphdr *th,
166 					       u16 *mssp)
167 {
168 #if IS_ENABLED(CONFIG_SYN_COOKIES)
169 #if IS_MODULE(CONFIG_IPV6)
170 	const struct nf_ipv6_ops *v6_ops = nf_get_ipv6_ops();
171 
172 	if (v6_ops)
173 		return v6_ops->cookie_init_sequence(iph, th, mssp);
174 #elif IS_BUILTIN(CONFIG_IPV6)
175 	return __cookie_v6_init_sequence(iph, th, mssp);
176 #endif
177 #endif
178 	return 0;
179 }
180 
nf_cookie_v6_check(const struct ipv6hdr * iph,const struct tcphdr * th,__u32 cookie)181 static inline int nf_cookie_v6_check(const struct ipv6hdr *iph,
182 				     const struct tcphdr *th, __u32 cookie)
183 {
184 #if IS_ENABLED(CONFIG_SYN_COOKIES)
185 #if IS_MODULE(CONFIG_IPV6)
186 	const struct nf_ipv6_ops *v6_ops = nf_get_ipv6_ops();
187 
188 	if (v6_ops)
189 		return v6_ops->cookie_v6_check(iph, th, cookie);
190 #elif IS_BUILTIN(CONFIG_IPV6)
191 	return __cookie_v6_check(iph, th, cookie);
192 #endif
193 #endif
194 	return 0;
195 }
196 
197 __sum16 nf_ip6_checksum(struct sk_buff *skb, unsigned int hook,
198 			unsigned int dataoff, u_int8_t protocol);
199 
200 int nf_ip6_check_hbh_len(struct sk_buff *skb, u32 *plen);
201 
202 int ipv6_netfilter_init(void);
203 void ipv6_netfilter_fini(void);
204 
205 #else /* CONFIG_NETFILTER */
ipv6_netfilter_init(void)206 static inline int ipv6_netfilter_init(void) { return 0; }
ipv6_netfilter_fini(void)207 static inline void ipv6_netfilter_fini(void) { return; }
nf_get_ipv6_ops(void)208 static inline const struct nf_ipv6_ops *nf_get_ipv6_ops(void) { return NULL; }
209 #endif /* CONFIG_NETFILTER */
210 
211 #endif /*__LINUX_IP6_NETFILTER_H*/
212