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
43 #include <linux/config.h>
44 #ifdef CONFIG_NETFILTER
46 extern void netfilter_init(void);
48 /* Largest hook number + 1 */
49 #define NF_MAX_HOOKS 8
54 typedef unsigned int nf_hookfn(unsigned int hooknum,
56 const struct net_device *in,
57 const struct net_device *out,
58 int (*okfn)(struct sk_buff *));
62 struct list_head list;
64 /* User fills in from here down. */
69 /* Hooks are ordered in ascending priority. */
75 struct list_head list;
79 /* Non-inclusive ranges: use 0/0/NULL to never get called. */
82 int (*set)(struct sock *sk, int optval, void __user *user, unsigned int len);
83 int (*compat_set)(struct sock *sk, int optval,
84 void __user *user, unsigned int len);
88 int (*get)(struct sock *sk, int optval, void __user *user, int *len);
89 int (*compat_get)(struct sock *sk, int optval,
90 void __user *user, int *len);
92 /* Number of users inside set() or get(). */
94 struct task_struct *cleanup_task;
97 /* Each queued (to userspace) skbuff has one of these. */
100 /* The ops struct which sent us to userspace. */
101 struct nf_hook_ops *elem;
103 /* If we're sent to userspace, this keeps housekeeping info */
106 struct net_device *indev, *outdev;
107 int (*okfn)(struct sk_buff *);
110 /* Function to register/unregister hook points. */
111 int nf_register_hook(struct nf_hook_ops *reg);
112 void nf_unregister_hook(struct nf_hook_ops *reg);
113 int nf_register_hooks(struct nf_hook_ops *reg, unsigned int n);
114 void nf_unregister_hooks(struct nf_hook_ops *reg, unsigned int n);
116 /* Functions to register get/setsockopt ranges (non-inclusive). You
117 need to check permissions yourself! */
118 int nf_register_sockopt(struct nf_sockopt_ops *reg);
119 void nf_unregister_sockopt(struct nf_sockopt_ops *reg);
121 extern struct list_head nf_hooks[NPROTO][NF_MAX_HOOKS];
123 /* those NF_LOG_* defines and struct nf_loginfo are legacy definitios that will
124 * disappear once iptables is replaced with pkttables. Please DO NOT use them
125 * for any new code! */
126 #define NF_LOG_TCPSEQ 0x01 /* Log TCP sequence numbers */
127 #define NF_LOG_TCPOPT 0x02 /* Log TCP options */
128 #define NF_LOG_IPOPT 0x04 /* Log IP options */
129 #define NF_LOG_UID 0x08 /* Log UID owning local socket */
130 #define NF_LOG_MASK 0x0f
132 #define NF_LOG_TYPE_LOG 0x01
133 #define NF_LOG_TYPE_ULOG 0x02
141 u_int16_t qthreshold;
150 typedef void nf_logfn(unsigned int pf,
151 unsigned int hooknum,
152 const struct sk_buff *skb,
153 const struct net_device *in,
154 const struct net_device *out,
155 const struct nf_loginfo *li,
164 /* Function to register/unregister log function. */
165 int nf_log_register(int pf, struct nf_logger *logger);
166 int nf_log_unregister_pf(int pf);
167 void nf_log_unregister_logger(struct nf_logger *logger);
169 /* Calls the registered backend logging function */
170 void nf_log_packet(int pf,
171 unsigned int hooknum,
172 const struct sk_buff *skb,
173 const struct net_device *in,
174 const struct net_device *out,
175 struct nf_loginfo *li,
176 const char *fmt, ...);
178 int nf_hook_slow(int pf, unsigned int hook, struct sk_buff **pskb,
179 struct net_device *indev, struct net_device *outdev,
180 int (*okfn)(struct sk_buff *), int thresh);
183 * nf_hook_thresh - call a netfilter hook
185 * Returns 1 if the hook has allowed the packet to pass. The function
186 * okfn must be invoked by the caller in this case. Any other return
187 * value indicates the packet has been consumed by the hook.
189 static inline int nf_hook_thresh(int pf, unsigned int hook,
190 struct sk_buff **pskb,
191 struct net_device *indev,
192 struct net_device *outdev,
193 int (*okfn)(struct sk_buff *), int thresh,
198 #ifndef CONFIG_NETFILTER_DEBUG
199 if (list_empty(&nf_hooks[pf][hook]))
202 return nf_hook_slow(pf, hook, pskb, indev, outdev, okfn, thresh);
205 static inline int nf_hook(int pf, unsigned int hook, struct sk_buff **pskb,
206 struct net_device *indev, struct net_device *outdev,
207 int (*okfn)(struct sk_buff *))
209 return nf_hook_thresh(pf, hook, pskb, indev, outdev, okfn, INT_MIN, 1);
212 /* Activate hook; either okfn or kfree_skb called, unless a hook
213 returns NF_STOLEN (in which case, it's up to the hook to deal with
216 Returns -ERRNO if packet dropped. Zero means queued, stolen or
221 > I don't want nf_hook to return anything because people might forget
222 > about async and trust the return value to mean "packet was ok".
225 Just document it clearly, then you can expect some sense from kernel
229 /* This is gross, but inline doesn't cut it for avoiding the function
230 call in fast path: gcc doesn't inline (needs value tracking?). --RR */
232 /* HX: It's slightly less gross now. */
234 #define NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, thresh) \
236 if ((__ret=nf_hook_thresh(pf, hook, &(skb), indev, outdev, okfn, thresh, 1)) == 1)\
237 __ret = (okfn)(skb); \
240 #define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond) \
242 if ((__ret=nf_hook_thresh(pf, hook, &(skb), indev, outdev, okfn, INT_MIN, cond)) == 1)\
243 __ret = (okfn)(skb); \
246 #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) \
247 NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, INT_MIN)
249 /* Call setsockopt() */
250 int nf_setsockopt(struct sock *sk, int pf, int optval, char __user *opt,
252 int nf_getsockopt(struct sock *sk, int pf, int optval, char __user *opt,
255 int compat_nf_setsockopt(struct sock *sk, int pf, int optval,
256 char __user *opt, int len);
257 int compat_nf_getsockopt(struct sock *sk, int pf, int optval,
258 char __user *opt, int *len);
261 struct nf_queue_handler {
262 int (*outfn)(struct sk_buff *skb, struct nf_info *info,
263 unsigned int queuenum, void *data);
267 extern int nf_register_queue_handler(int pf,
268 struct nf_queue_handler *qh);
269 extern int nf_unregister_queue_handler(int pf);
270 extern void nf_unregister_queue_handlers(struct nf_queue_handler *qh);
271 extern void nf_reinject(struct sk_buff *skb,
272 struct nf_info *info,
273 unsigned int verdict);
275 extern void (*ip_ct_attach)(struct sk_buff *, struct sk_buff *);
276 extern void nf_ct_attach(struct sk_buff *, struct sk_buff *);
278 /* FIXME: Before cache is ever used, this must be implemented for real. */
279 extern void nf_invalidate_cache(int pf);
281 /* Call this before modifying an existing packet: ensures it is
282 modifiable and linear to the point you care about (writable_len).
283 Returns true or false. */
284 extern int skb_make_writable(struct sk_buff **pskb, unsigned int writable_len);
287 unsigned short family;
288 unsigned int (*checksum)(struct sk_buff *skb, unsigned int hook,
289 unsigned int dataoff, u_int8_t protocol);
290 void (*saveroute)(const struct sk_buff *skb,
291 struct nf_info *info);
292 int (*reroute)(struct sk_buff **skb,
293 const struct nf_info *info);
297 extern struct nf_afinfo *nf_afinfo[];
298 static inline struct nf_afinfo *nf_get_afinfo(unsigned short family)
300 return rcu_dereference(nf_afinfo[family]);
303 static inline unsigned int
304 nf_checksum(struct sk_buff *skb, unsigned int hook, unsigned int dataoff,
305 u_int8_t protocol, unsigned short family)
307 struct nf_afinfo *afinfo;
308 unsigned int csum = 0;
311 afinfo = nf_get_afinfo(family);
313 csum = afinfo->checksum(skb, hook, dataoff, protocol);
318 extern int nf_register_afinfo(struct nf_afinfo *afinfo);
319 extern void nf_unregister_afinfo(struct nf_afinfo *afinfo);
321 #define nf_info_reroute(x) ((void *)x + sizeof(struct nf_info))
323 #include <net/flow.h>
324 extern void (*ip_nat_decode_session)(struct sk_buff *, struct flowi *);
327 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, int family)
329 #ifdef CONFIG_IP_NF_NAT_NEEDED
330 void (*decodefn)(struct sk_buff *, struct flowi *);
332 if (family == AF_INET && (decodefn = ip_nat_decode_session) != NULL)
337 #ifdef CONFIG_PROC_FS
338 #include <linux/proc_fs.h>
339 extern struct proc_dir_entry *proc_net_netfilter;
342 #else /* !CONFIG_NETFILTER */
343 #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) (okfn)(skb)
344 #define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond) (okfn)(skb)
345 static inline int nf_hook_thresh(int pf, unsigned int hook,
346 struct sk_buff **pskb,
347 struct net_device *indev,
348 struct net_device *outdev,
349 int (*okfn)(struct sk_buff *), int thresh,
354 static inline int nf_hook(int pf, unsigned int hook, struct sk_buff **pskb,
355 struct net_device *indev, struct net_device *outdev,
356 int (*okfn)(struct sk_buff *))
360 static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
363 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, int family) {}
364 #endif /*CONFIG_NETFILTER*/
366 #endif /*__KERNEL__*/
367 #endif /*__LINUX_NETFILTER_H*/