1 #ifndef __LINUX_NETFILTER_H
2 #define __LINUX_NETFILTER_H
4 #include <linux/init.h>
5 #include <linux/skbuff.h>
10 #include <linux/wait.h>
11 #include <linux/list.h>
12 #include <linux/static_key.h>
13 #include <uapi/linux/netfilter.h>
14 #ifdef CONFIG_NETFILTER
15 static inline int NF_DROP_GETERR(int verdict
)
17 return -(verdict
>> NF_VERDICT_QBITS
);
20 static inline int nf_inet_addr_cmp(const union nf_inet_addr
*a1
,
21 const union nf_inet_addr
*a2
)
23 return a1
->all
[0] == a2
->all
[0] &&
24 a1
->all
[1] == a2
->all
[1] &&
25 a1
->all
[2] == a2
->all
[2] &&
26 a1
->all
[3] == a2
->all
[3];
29 static inline void nf_inet_addr_mask(const union nf_inet_addr
*a1
,
30 union nf_inet_addr
*result
,
31 const union nf_inet_addr
*mask
)
33 result
->all
[0] = a1
->all
[0] & mask
->all
[0];
34 result
->all
[1] = a1
->all
[1] & mask
->all
[1];
35 result
->all
[2] = a1
->all
[2] & mask
->all
[2];
36 result
->all
[3] = a1
->all
[3] & mask
->all
[3];
39 int netfilter_init(void);
41 /* Largest hook number + 1 */
42 #define NF_MAX_HOOKS 8
47 typedef unsigned int nf_hookfn(const struct nf_hook_ops
*ops
,
49 const struct net_device
*in
,
50 const struct net_device
*out
,
51 int (*okfn
)(struct sk_buff
*));
54 struct list_head list
;
56 /* User fills in from here down. */
62 /* Hooks are ordered in ascending priority. */
66 struct nf_sockopt_ops
{
67 struct list_head list
;
71 /* Non-inclusive ranges: use 0/0/NULL to never get called. */
74 int (*set
)(struct sock
*sk
, int optval
, void __user
*user
, unsigned int len
);
76 int (*compat_set
)(struct sock
*sk
, int optval
,
77 void __user
*user
, unsigned int len
);
81 int (*get
)(struct sock
*sk
, int optval
, void __user
*user
, int *len
);
83 int (*compat_get
)(struct sock
*sk
, int optval
,
84 void __user
*user
, int *len
);
86 /* Use the module struct to lock set/get code in place */
90 /* Function to register/unregister hook points. */
91 int nf_register_hook(struct nf_hook_ops
*reg
);
92 void nf_unregister_hook(struct nf_hook_ops
*reg
);
93 int nf_register_hooks(struct nf_hook_ops
*reg
, unsigned int n
);
94 void nf_unregister_hooks(struct nf_hook_ops
*reg
, unsigned int n
);
96 /* Functions to register get/setsockopt ranges (non-inclusive). You
97 need to check permissions yourself! */
98 int nf_register_sockopt(struct nf_sockopt_ops
*reg
);
99 void nf_unregister_sockopt(struct nf_sockopt_ops
*reg
);
101 extern struct list_head nf_hooks
[NFPROTO_NUMPROTO
][NF_MAX_HOOKS
];
103 #ifdef HAVE_JUMP_LABEL
104 extern struct static_key nf_hooks_needed
[NFPROTO_NUMPROTO
][NF_MAX_HOOKS
];
106 static inline bool nf_hooks_active(u_int8_t pf
, unsigned int hook
)
108 if (__builtin_constant_p(pf
) &&
109 __builtin_constant_p(hook
))
110 return static_key_false(&nf_hooks_needed
[pf
][hook
]);
112 return !list_empty(&nf_hooks
[pf
][hook
]);
115 static inline bool nf_hooks_active(u_int8_t pf
, unsigned int hook
)
117 return !list_empty(&nf_hooks
[pf
][hook
]);
121 int nf_hook_slow(u_int8_t pf
, unsigned int hook
, struct sk_buff
*skb
,
122 struct net_device
*indev
, struct net_device
*outdev
,
123 int (*okfn
)(struct sk_buff
*), int thresh
);
126 * nf_hook_thresh - call a netfilter hook
128 * Returns 1 if the hook has allowed the packet to pass. The function
129 * okfn must be invoked by the caller in this case. Any other return
130 * value indicates the packet has been consumed by the hook.
132 static inline int nf_hook_thresh(u_int8_t pf
, unsigned int hook
,
134 struct net_device
*indev
,
135 struct net_device
*outdev
,
136 int (*okfn
)(struct sk_buff
*), int thresh
)
138 if (nf_hooks_active(pf
, hook
))
139 return nf_hook_slow(pf
, hook
, skb
, indev
, outdev
, okfn
, thresh
);
143 static inline int nf_hook(u_int8_t pf
, unsigned int hook
, struct sk_buff
*skb
,
144 struct net_device
*indev
, struct net_device
*outdev
,
145 int (*okfn
)(struct sk_buff
*))
147 return nf_hook_thresh(pf
, hook
, skb
, indev
, outdev
, okfn
, INT_MIN
);
150 /* Activate hook; either okfn or kfree_skb called, unless a hook
151 returns NF_STOLEN (in which case, it's up to the hook to deal with
154 Returns -ERRNO if packet dropped. Zero means queued, stolen or
159 > I don't want nf_hook to return anything because people might forget
160 > about async and trust the return value to mean "packet was ok".
163 Just document it clearly, then you can expect some sense from kernel
168 NF_HOOK_THRESH(uint8_t pf
, unsigned int hook
, struct sk_buff
*skb
,
169 struct net_device
*in
, struct net_device
*out
,
170 int (*okfn
)(struct sk_buff
*), int thresh
)
172 int ret
= nf_hook_thresh(pf
, hook
, skb
, in
, out
, okfn
, thresh
);
179 NF_HOOK_COND(uint8_t pf
, unsigned int hook
, struct sk_buff
*skb
,
180 struct net_device
*in
, struct net_device
*out
,
181 int (*okfn
)(struct sk_buff
*), bool cond
)
186 ((ret
= nf_hook_thresh(pf
, hook
, skb
, in
, out
, okfn
, INT_MIN
)) == 1))
192 NF_HOOK(uint8_t pf
, unsigned int hook
, struct sk_buff
*skb
,
193 struct net_device
*in
, struct net_device
*out
,
194 int (*okfn
)(struct sk_buff
*))
196 return NF_HOOK_THRESH(pf
, hook
, skb
, in
, out
, okfn
, INT_MIN
);
199 /* Call setsockopt() */
200 int nf_setsockopt(struct sock
*sk
, u_int8_t pf
, int optval
, char __user
*opt
,
202 int nf_getsockopt(struct sock
*sk
, u_int8_t pf
, int optval
, char __user
*opt
,
205 int compat_nf_setsockopt(struct sock
*sk
, u_int8_t pf
, int optval
,
206 char __user
*opt
, unsigned int len
);
207 int compat_nf_getsockopt(struct sock
*sk
, u_int8_t pf
, int optval
,
208 char __user
*opt
, int *len
);
211 /* Call this before modifying an existing packet: ensures it is
212 modifiable and linear to the point you care about (writable_len).
213 Returns true or false. */
214 int skb_make_writable(struct sk_buff
*skb
, unsigned int writable_len
);
217 struct nf_queue_entry
;
220 unsigned short family
;
221 __sum16 (*checksum
)(struct sk_buff
*skb
, unsigned int hook
,
222 unsigned int dataoff
, u_int8_t protocol
);
223 __sum16 (*checksum_partial
)(struct sk_buff
*skb
,
225 unsigned int dataoff
,
228 int (*route
)(struct net
*net
, struct dst_entry
**dst
,
229 struct flowi
*fl
, bool strict
);
230 void (*saveroute
)(const struct sk_buff
*skb
,
231 struct nf_queue_entry
*entry
);
232 int (*reroute
)(struct sk_buff
*skb
,
233 const struct nf_queue_entry
*entry
);
237 extern const struct nf_afinfo __rcu
*nf_afinfo
[NFPROTO_NUMPROTO
];
238 static inline const struct nf_afinfo
*nf_get_afinfo(unsigned short family
)
240 return rcu_dereference(nf_afinfo
[family
]);
243 static inline __sum16
244 nf_checksum(struct sk_buff
*skb
, unsigned int hook
, unsigned int dataoff
,
245 u_int8_t protocol
, unsigned short family
)
247 const struct nf_afinfo
*afinfo
;
251 afinfo
= nf_get_afinfo(family
);
253 csum
= afinfo
->checksum(skb
, hook
, dataoff
, protocol
);
258 static inline __sum16
259 nf_checksum_partial(struct sk_buff
*skb
, unsigned int hook
,
260 unsigned int dataoff
, unsigned int len
,
261 u_int8_t protocol
, unsigned short family
)
263 const struct nf_afinfo
*afinfo
;
267 afinfo
= nf_get_afinfo(family
);
269 csum
= afinfo
->checksum_partial(skb
, hook
, dataoff
, len
,
275 int nf_register_afinfo(const struct nf_afinfo
*afinfo
);
276 void nf_unregister_afinfo(const struct nf_afinfo
*afinfo
);
278 #include <net/flow.h>
279 extern void (*nf_nat_decode_session_hook
)(struct sk_buff
*, struct flowi
*);
282 nf_nat_decode_session(struct sk_buff
*skb
, struct flowi
*fl
, u_int8_t family
)
284 #ifdef CONFIG_NF_NAT_NEEDED
285 void (*decodefn
)(struct sk_buff
*, struct flowi
*);
288 decodefn
= rcu_dereference(nf_nat_decode_session_hook
);
295 #else /* !CONFIG_NETFILTER */
296 #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) (okfn)(skb)
297 #define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond) (okfn)(skb)
298 static inline int nf_hook_thresh(u_int8_t pf
, unsigned int hook
,
300 struct net_device
*indev
,
301 struct net_device
*outdev
,
302 int (*okfn
)(struct sk_buff
*), int thresh
)
306 static inline int nf_hook(u_int8_t pf
, unsigned int hook
, struct sk_buff
*skb
,
307 struct net_device
*indev
, struct net_device
*outdev
,
308 int (*okfn
)(struct sk_buff
*))
314 nf_nat_decode_session(struct sk_buff
*skb
, struct flowi
*fl
, u_int8_t family
)
317 #endif /*CONFIG_NETFILTER*/
319 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
320 extern void (*ip_ct_attach
)(struct sk_buff
*, const struct sk_buff
*) __rcu
;
321 void nf_ct_attach(struct sk_buff
*, const struct sk_buff
*);
322 extern void (*nf_ct_destroy
)(struct nf_conntrack
*) __rcu
;
325 enum ip_conntrack_info
;
329 size_t (*build_size
)(const struct nf_conn
*ct
);
330 int (*build
)(struct sk_buff
*skb
, struct nf_conn
*ct
);
331 int (*parse
)(const struct nlattr
*attr
, struct nf_conn
*ct
);
332 int (*attach_expect
)(const struct nlattr
*attr
, struct nf_conn
*ct
,
333 u32 portid
, u32 report
);
334 void (*seq_adjust
)(struct sk_buff
*skb
, struct nf_conn
*ct
,
335 enum ip_conntrack_info ctinfo
, s32 off
);
337 extern struct nfq_ct_hook __rcu
*nfq_ct_hook
;
339 static inline void nf_ct_attach(struct sk_buff
*new, struct sk_buff
*skb
) {}
342 #endif /*__LINUX_NETFILTER_H*/