1 #ifndef __LINUX_NETFILTER_H
2 #define __LINUX_NETFILTER_H
5 #include <linux/init.h>
6 #include <linux/types.h>
7 #include <linux/skbuff.h>
10 #include <linux/wait.h>
11 #include <linux/list.h>
13 #include <linux/compiler.h>
15 /* Responses from hook functions. */
22 #define NF_MAX_VERDICT NF_STOP
24 /* we overload the higher bits for encoding auxiliary data such as the queue
25 * number. Not nice, but better than additional function arguments. */
26 #define NF_VERDICT_MASK 0x0000ffff
27 #define NF_VERDICT_BITS 16
29 #define NF_VERDICT_QMASK 0xffff0000
30 #define NF_VERDICT_QBITS 16
32 #define NF_QUEUE_NR(x) (((x << NF_VERDICT_QBITS) & NF_VERDICT_QMASK) | NF_QUEUE)
34 /* only for userspace compatibility */
36 /* Generic cache responses from hook functions.
37 <= 0x2000 is used for protocol-flags. */
38 #define NFC_UNKNOWN 0x4000
39 #define NFC_ALTERED 0x8000
52 #ifdef CONFIG_NETFILTER
54 extern void netfilter_init(void);
56 /* Largest hook number + 1 */
57 #define NF_MAX_HOOKS 8
62 typedef unsigned int nf_hookfn(unsigned int hooknum
,
64 const struct net_device
*in
,
65 const struct net_device
*out
,
66 int (*okfn
)(struct sk_buff
*));
70 struct list_head list
;
72 /* User fills in from here down. */
77 /* Hooks are ordered in ascending priority. */
83 struct list_head list
;
87 /* Non-inclusive ranges: use 0/0/NULL to never get called. */
90 int (*set
)(struct sock
*sk
, int optval
, void __user
*user
, unsigned int len
);
91 int (*compat_set
)(struct sock
*sk
, int optval
,
92 void __user
*user
, unsigned int len
);
96 int (*get
)(struct sock
*sk
, int optval
, void __user
*user
, int *len
);
97 int (*compat_get
)(struct sock
*sk
, int optval
,
98 void __user
*user
, int *len
);
100 /* Use the module struct to lock set/get code in place */
101 struct module
*owner
;
104 /* Function to register/unregister hook points. */
105 int nf_register_hook(struct nf_hook_ops
*reg
);
106 void nf_unregister_hook(struct nf_hook_ops
*reg
);
107 int nf_register_hooks(struct nf_hook_ops
*reg
, unsigned int n
);
108 void nf_unregister_hooks(struct nf_hook_ops
*reg
, unsigned int n
);
110 /* Functions to register get/setsockopt ranges (non-inclusive). You
111 need to check permissions yourself! */
112 int nf_register_sockopt(struct nf_sockopt_ops
*reg
);
113 void nf_unregister_sockopt(struct nf_sockopt_ops
*reg
);
116 /* Sysctl registration */
117 struct ctl_table_header
*nf_register_sysctl_table(struct ctl_table
*path
,
118 struct ctl_table
*table
);
119 void nf_unregister_sysctl_table(struct ctl_table_header
*header
,
120 struct ctl_table
*table
);
121 extern struct ctl_table nf_net_netfilter_sysctl_path
[];
122 extern struct ctl_table nf_net_ipv4_netfilter_sysctl_path
[];
123 #endif /* CONFIG_SYSCTL */
125 extern struct list_head nf_hooks
[NPROTO
][NF_MAX_HOOKS
];
127 /* those NF_LOG_* defines and struct nf_loginfo are legacy definitios that will
128 * disappear once iptables is replaced with pkttables. Please DO NOT use them
129 * for any new code! */
130 #define NF_LOG_TCPSEQ 0x01 /* Log TCP sequence numbers */
131 #define NF_LOG_TCPOPT 0x02 /* Log TCP options */
132 #define NF_LOG_IPOPT 0x04 /* Log IP options */
133 #define NF_LOG_UID 0x08 /* Log UID owning local socket */
134 #define NF_LOG_MASK 0x0f
136 #define NF_LOG_TYPE_LOG 0x01
137 #define NF_LOG_TYPE_ULOG 0x02
145 u_int16_t qthreshold
;
154 typedef void nf_logfn(unsigned int pf
,
155 unsigned int hooknum
,
156 const struct sk_buff
*skb
,
157 const struct net_device
*in
,
158 const struct net_device
*out
,
159 const struct nf_loginfo
*li
,
168 /* Function to register/unregister log function. */
169 int nf_log_register(int pf
, struct nf_logger
*logger
);
170 void nf_log_unregister(struct nf_logger
*logger
);
171 void nf_log_unregister_pf(int pf
);
173 /* Calls the registered backend logging function */
174 void nf_log_packet(int pf
,
175 unsigned int hooknum
,
176 const struct sk_buff
*skb
,
177 const struct net_device
*in
,
178 const struct net_device
*out
,
179 struct nf_loginfo
*li
,
180 const char *fmt
, ...);
182 int nf_hook_slow(int pf
, unsigned int hook
, struct sk_buff
*skb
,
183 struct net_device
*indev
, struct net_device
*outdev
,
184 int (*okfn
)(struct sk_buff
*), int thresh
);
187 * nf_hook_thresh - call a netfilter hook
189 * Returns 1 if the hook has allowed the packet to pass. The function
190 * okfn must be invoked by the caller in this case. Any other return
191 * value indicates the packet has been consumed by the hook.
193 static inline int nf_hook_thresh(int pf
, unsigned int hook
,
195 struct net_device
*indev
,
196 struct net_device
*outdev
,
197 int (*okfn
)(struct sk_buff
*), int thresh
,
202 #ifndef CONFIG_NETFILTER_DEBUG
203 if (list_empty(&nf_hooks
[pf
][hook
]))
206 return nf_hook_slow(pf
, hook
, skb
, indev
, outdev
, okfn
, thresh
);
209 static inline int nf_hook(int pf
, unsigned int hook
, struct sk_buff
*skb
,
210 struct net_device
*indev
, struct net_device
*outdev
,
211 int (*okfn
)(struct sk_buff
*))
213 return nf_hook_thresh(pf
, hook
, skb
, indev
, outdev
, okfn
, INT_MIN
, 1);
216 /* Activate hook; either okfn or kfree_skb called, unless a hook
217 returns NF_STOLEN (in which case, it's up to the hook to deal with
220 Returns -ERRNO if packet dropped. Zero means queued, stolen or
225 > I don't want nf_hook to return anything because people might forget
226 > about async and trust the return value to mean "packet was ok".
229 Just document it clearly, then you can expect some sense from kernel
233 /* This is gross, but inline doesn't cut it for avoiding the function
234 call in fast path: gcc doesn't inline (needs value tracking?). --RR */
236 /* HX: It's slightly less gross now. */
238 #define NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, thresh) \
240 if ((__ret=nf_hook_thresh(pf, hook, (skb), indev, outdev, okfn, thresh, 1)) == 1)\
241 __ret = (okfn)(skb); \
244 #define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond) \
246 if ((__ret=nf_hook_thresh(pf, hook, (skb), indev, outdev, okfn, INT_MIN, cond)) == 1)\
247 __ret = (okfn)(skb); \
250 #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) \
251 NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, INT_MIN)
253 /* Call setsockopt() */
254 int nf_setsockopt(struct sock
*sk
, int pf
, int optval
, char __user
*opt
,
256 int nf_getsockopt(struct sock
*sk
, int pf
, int optval
, char __user
*opt
,
259 int compat_nf_setsockopt(struct sock
*sk
, int pf
, int optval
,
260 char __user
*opt
, int len
);
261 int compat_nf_getsockopt(struct sock
*sk
, int pf
, int optval
,
262 char __user
*opt
, int *len
);
264 /* FIXME: Before cache is ever used, this must be implemented for real. */
265 extern void nf_invalidate_cache(int pf
);
267 /* Call this before modifying an existing packet: ensures it is
268 modifiable and linear to the point you care about (writable_len).
269 Returns true or false. */
270 extern int skb_make_writable(struct sk_buff
*skb
, unsigned int writable_len
);
273 struct nf_queue_entry
;
276 unsigned short family
;
277 __sum16 (*checksum
)(struct sk_buff
*skb
, unsigned int hook
,
278 unsigned int dataoff
, u_int8_t protocol
);
279 int (*route
)(struct dst_entry
**dst
, struct flowi
*fl
);
280 void (*saveroute
)(const struct sk_buff
*skb
,
281 struct nf_queue_entry
*entry
);
282 int (*reroute
)(struct sk_buff
*skb
,
283 const struct nf_queue_entry
*entry
);
287 extern struct nf_afinfo
*nf_afinfo
[];
288 static inline struct nf_afinfo
*nf_get_afinfo(unsigned short family
)
290 return rcu_dereference(nf_afinfo
[family
]);
293 static inline __sum16
294 nf_checksum(struct sk_buff
*skb
, unsigned int hook
, unsigned int dataoff
,
295 u_int8_t protocol
, unsigned short family
)
297 struct nf_afinfo
*afinfo
;
301 afinfo
= nf_get_afinfo(family
);
303 csum
= afinfo
->checksum(skb
, hook
, dataoff
, protocol
);
308 extern int nf_register_afinfo(struct nf_afinfo
*afinfo
);
309 extern void nf_unregister_afinfo(struct nf_afinfo
*afinfo
);
311 #include <net/flow.h>
312 extern void (*ip_nat_decode_session
)(struct sk_buff
*, struct flowi
*);
315 nf_nat_decode_session(struct sk_buff
*skb
, struct flowi
*fl
, int family
)
317 #if defined(CONFIG_IP_NF_NAT_NEEDED) || defined(CONFIG_NF_NAT_NEEDED)
318 void (*decodefn
)(struct sk_buff
*, struct flowi
*);
320 if (family
== AF_INET
&& (decodefn
= ip_nat_decode_session
) != NULL
)
325 #ifdef CONFIG_PROC_FS
326 #include <linux/proc_fs.h>
327 extern struct proc_dir_entry
*proc_net_netfilter
;
330 #else /* !CONFIG_NETFILTER */
331 #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) (okfn)(skb)
332 #define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond) (okfn)(skb)
333 static inline int nf_hook_thresh(int pf
, unsigned int hook
,
335 struct net_device
*indev
,
336 struct net_device
*outdev
,
337 int (*okfn
)(struct sk_buff
*), int thresh
,
342 static inline int nf_hook(int pf
, unsigned int hook
, struct sk_buff
*skb
,
343 struct net_device
*indev
, struct net_device
*outdev
,
344 int (*okfn
)(struct sk_buff
*))
350 nf_nat_decode_session(struct sk_buff
*skb
, struct flowi
*fl
, int family
) {}
351 #endif /*CONFIG_NETFILTER*/
353 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
354 extern void (*ip_ct_attach
)(struct sk_buff
*, struct sk_buff
*);
355 extern void nf_ct_attach(struct sk_buff
*, struct sk_buff
*);
356 extern void (*nf_ct_destroy
)(struct nf_conntrack
*);
358 static inline void nf_ct_attach(struct sk_buff
*new, struct sk_buff
*skb
) {}
361 #endif /*__KERNEL__*/
362 #endif /*__LINUX_NETFILTER_H*/