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 <uapi/linux/netfilter.h>
13 #ifdef CONFIG_NETFILTER
14 static inline int NF_DROP_GETERR(int verdict
)
16 return -(verdict
>> NF_VERDICT_QBITS
);
19 static inline int nf_inet_addr_cmp(const union nf_inet_addr
*a1
,
20 const union nf_inet_addr
*a2
)
22 return a1
->all
[0] == a2
->all
[0] &&
23 a1
->all
[1] == a2
->all
[1] &&
24 a1
->all
[2] == a2
->all
[2] &&
25 a1
->all
[3] == a2
->all
[3];
28 static inline void nf_inet_addr_mask(const union nf_inet_addr
*a1
,
29 union nf_inet_addr
*result
,
30 const union nf_inet_addr
*mask
)
32 result
->all
[0] = a1
->all
[0] & mask
->all
[0];
33 result
->all
[1] = a1
->all
[1] & mask
->all
[1];
34 result
->all
[2] = a1
->all
[2] & mask
->all
[2];
35 result
->all
[3] = a1
->all
[3] & mask
->all
[3];
38 int netfilter_init(void);
40 /* Largest hook number + 1 */
41 #define NF_MAX_HOOKS 8
46 typedef unsigned int nf_hookfn(const struct nf_hook_ops
*ops
,
48 const struct net_device
*in
,
49 const struct net_device
*out
,
50 int (*okfn
)(struct sk_buff
*));
53 struct list_head list
;
55 /* User fills in from here down. */
61 /* Hooks are ordered in ascending priority. */
65 struct nf_sockopt_ops
{
66 struct list_head list
;
70 /* Non-inclusive ranges: use 0/0/NULL to never get called. */
73 int (*set
)(struct sock
*sk
, int optval
, void __user
*user
, unsigned int len
);
75 int (*compat_set
)(struct sock
*sk
, int optval
,
76 void __user
*user
, unsigned int len
);
80 int (*get
)(struct sock
*sk
, int optval
, void __user
*user
, int *len
);
82 int (*compat_get
)(struct sock
*sk
, int optval
,
83 void __user
*user
, int *len
);
85 /* Use the module struct to lock set/get code in place */
89 /* Function to register/unregister hook points. */
90 int nf_register_hook(struct nf_hook_ops
*reg
);
91 void nf_unregister_hook(struct nf_hook_ops
*reg
);
92 int nf_register_hooks(struct nf_hook_ops
*reg
, unsigned int n
);
93 void nf_unregister_hooks(struct nf_hook_ops
*reg
, unsigned int n
);
95 /* Functions to register get/setsockopt ranges (non-inclusive). You
96 need to check permissions yourself! */
97 int nf_register_sockopt(struct nf_sockopt_ops
*reg
);
98 void nf_unregister_sockopt(struct nf_sockopt_ops
*reg
);
100 extern struct list_head nf_hooks
[NFPROTO_NUMPROTO
][NF_MAX_HOOKS
];
102 #if defined(CONFIG_JUMP_LABEL)
103 #include <linux/static_key.h>
104 extern struct static_key nf_hooks_needed
[NFPROTO_NUMPROTO
][NF_MAX_HOOKS
];
105 static inline bool nf_hooks_active(u_int8_t pf
, unsigned int hook
)
107 if (__builtin_constant_p(pf
) &&
108 __builtin_constant_p(hook
))
109 return static_key_false(&nf_hooks_needed
[pf
][hook
]);
111 return !list_empty(&nf_hooks
[pf
][hook
]);
114 static inline bool nf_hooks_active(u_int8_t pf
, unsigned int hook
)
116 return !list_empty(&nf_hooks
[pf
][hook
]);
120 int nf_hook_slow(u_int8_t pf
, unsigned int hook
, struct sk_buff
*skb
,
121 struct net_device
*indev
, struct net_device
*outdev
,
122 int (*okfn
)(struct sk_buff
*), int thresh
);
125 * nf_hook_thresh - call a netfilter hook
127 * Returns 1 if the hook has allowed the packet to pass. The function
128 * okfn must be invoked by the caller in this case. Any other return
129 * value indicates the packet has been consumed by the hook.
131 static inline int nf_hook_thresh(u_int8_t pf
, unsigned int hook
,
133 struct net_device
*indev
,
134 struct net_device
*outdev
,
135 int (*okfn
)(struct sk_buff
*), int thresh
)
137 if (nf_hooks_active(pf
, hook
))
138 return nf_hook_slow(pf
, hook
, skb
, indev
, outdev
, okfn
, thresh
);
142 static inline int nf_hook(u_int8_t pf
, unsigned int hook
, struct sk_buff
*skb
,
143 struct net_device
*indev
, struct net_device
*outdev
,
144 int (*okfn
)(struct sk_buff
*))
146 return nf_hook_thresh(pf
, hook
, skb
, indev
, outdev
, okfn
, INT_MIN
);
149 /* Activate hook; either okfn or kfree_skb called, unless a hook
150 returns NF_STOLEN (in which case, it's up to the hook to deal with
153 Returns -ERRNO if packet dropped. Zero means queued, stolen or
158 > I don't want nf_hook to return anything because people might forget
159 > about async and trust the return value to mean "packet was ok".
162 Just document it clearly, then you can expect some sense from kernel
167 NF_HOOK_THRESH(uint8_t pf
, unsigned int hook
, struct sk_buff
*skb
,
168 struct net_device
*in
, struct net_device
*out
,
169 int (*okfn
)(struct sk_buff
*), int thresh
)
171 int ret
= nf_hook_thresh(pf
, hook
, skb
, in
, out
, okfn
, thresh
);
178 NF_HOOK_COND(uint8_t pf
, unsigned int hook
, struct sk_buff
*skb
,
179 struct net_device
*in
, struct net_device
*out
,
180 int (*okfn
)(struct sk_buff
*), bool cond
)
185 ((ret
= nf_hook_thresh(pf
, hook
, skb
, in
, out
, okfn
, INT_MIN
)) == 1))
191 NF_HOOK(uint8_t pf
, unsigned int hook
, struct sk_buff
*skb
,
192 struct net_device
*in
, struct net_device
*out
,
193 int (*okfn
)(struct sk_buff
*))
195 return NF_HOOK_THRESH(pf
, hook
, skb
, in
, out
, okfn
, INT_MIN
);
198 /* Call setsockopt() */
199 int nf_setsockopt(struct sock
*sk
, u_int8_t pf
, int optval
, char __user
*opt
,
201 int nf_getsockopt(struct sock
*sk
, u_int8_t pf
, int optval
, char __user
*opt
,
204 int compat_nf_setsockopt(struct sock
*sk
, u_int8_t pf
, int optval
,
205 char __user
*opt
, unsigned int len
);
206 int compat_nf_getsockopt(struct sock
*sk
, u_int8_t pf
, int optval
,
207 char __user
*opt
, int *len
);
210 /* Call this before modifying an existing packet: ensures it is
211 modifiable and linear to the point you care about (writable_len).
212 Returns true or false. */
213 int skb_make_writable(struct sk_buff
*skb
, unsigned int writable_len
);
216 struct nf_queue_entry
;
219 unsigned short family
;
220 __sum16 (*checksum
)(struct sk_buff
*skb
, unsigned int hook
,
221 unsigned int dataoff
, u_int8_t protocol
);
222 __sum16 (*checksum_partial
)(struct sk_buff
*skb
,
224 unsigned int dataoff
,
227 int (*route
)(struct net
*net
, struct dst_entry
**dst
,
228 struct flowi
*fl
, bool strict
);
229 void (*saveroute
)(const struct sk_buff
*skb
,
230 struct nf_queue_entry
*entry
);
231 int (*reroute
)(struct sk_buff
*skb
,
232 const struct nf_queue_entry
*entry
);
236 extern const struct nf_afinfo __rcu
*nf_afinfo
[NFPROTO_NUMPROTO
];
237 static inline const struct nf_afinfo
*nf_get_afinfo(unsigned short family
)
239 return rcu_dereference(nf_afinfo
[family
]);
242 static inline __sum16
243 nf_checksum(struct sk_buff
*skb
, unsigned int hook
, unsigned int dataoff
,
244 u_int8_t protocol
, unsigned short family
)
246 const struct nf_afinfo
*afinfo
;
250 afinfo
= nf_get_afinfo(family
);
252 csum
= afinfo
->checksum(skb
, hook
, dataoff
, protocol
);
257 static inline __sum16
258 nf_checksum_partial(struct sk_buff
*skb
, unsigned int hook
,
259 unsigned int dataoff
, unsigned int len
,
260 u_int8_t protocol
, unsigned short family
)
262 const struct nf_afinfo
*afinfo
;
266 afinfo
= nf_get_afinfo(family
);
268 csum
= afinfo
->checksum_partial(skb
, hook
, dataoff
, len
,
274 int nf_register_afinfo(const struct nf_afinfo
*afinfo
);
275 void nf_unregister_afinfo(const struct nf_afinfo
*afinfo
);
277 #include <net/flow.h>
278 extern void (*nf_nat_decode_session_hook
)(struct sk_buff
*, struct flowi
*);
281 nf_nat_decode_session(struct sk_buff
*skb
, struct flowi
*fl
, u_int8_t family
)
283 #ifdef CONFIG_NF_NAT_NEEDED
284 void (*decodefn
)(struct sk_buff
*, struct flowi
*);
287 decodefn
= rcu_dereference(nf_nat_decode_session_hook
);
294 #else /* !CONFIG_NETFILTER */
295 #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) (okfn)(skb)
296 #define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond) (okfn)(skb)
297 static inline int nf_hook_thresh(u_int8_t pf
, unsigned int hook
,
299 struct net_device
*indev
,
300 struct net_device
*outdev
,
301 int (*okfn
)(struct sk_buff
*), int thresh
)
305 static inline int nf_hook(u_int8_t pf
, unsigned int hook
, struct sk_buff
*skb
,
306 struct net_device
*indev
, struct net_device
*outdev
,
307 int (*okfn
)(struct sk_buff
*))
313 nf_nat_decode_session(struct sk_buff
*skb
, struct flowi
*fl
, u_int8_t family
)
316 #endif /*CONFIG_NETFILTER*/
318 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
319 extern void (*ip_ct_attach
)(struct sk_buff
*, const struct sk_buff
*) __rcu
;
320 void nf_ct_attach(struct sk_buff
*, const struct sk_buff
*);
321 extern void (*nf_ct_destroy
)(struct nf_conntrack
*) __rcu
;
324 enum ip_conntrack_info
;
328 size_t (*build_size
)(const struct nf_conn
*ct
);
329 int (*build
)(struct sk_buff
*skb
, struct nf_conn
*ct
);
330 int (*parse
)(const struct nlattr
*attr
, struct nf_conn
*ct
);
331 int (*attach_expect
)(const struct nlattr
*attr
, struct nf_conn
*ct
,
332 u32 portid
, u32 report
);
333 void (*seq_adjust
)(struct sk_buff
*skb
, struct nf_conn
*ct
,
334 enum ip_conntrack_info ctinfo
, s32 off
);
336 extern struct nfq_ct_hook __rcu
*nfq_ct_hook
;
338 static inline void nf_ct_attach(struct sk_buff
*new, struct sk_buff
*skb
) {}
341 #endif /*__LINUX_NETFILTER_H*/