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>
14 #include <linux/rcupdate.h>
16 /* Responses from hook functions. */
23 #define NF_MAX_VERDICT NF_STOP
25 /* we overload the higher bits for encoding auxiliary data such as the queue
26 * number. Not nice, but better than additional function arguments. */
27 #define NF_VERDICT_MASK 0x0000ffff
28 #define NF_VERDICT_BITS 16
30 #define NF_VERDICT_QMASK 0xffff0000
31 #define NF_VERDICT_QBITS 16
33 #define NF_QUEUE_NR(x) (((x << NF_VERDICT_QBITS) & NF_VERDICT_QMASK) | NF_QUEUE)
35 /* only for userspace compatibility */
37 /* Generic cache responses from hook functions.
38 <= 0x2000 is used for protocol-flags. */
39 #define NFC_UNKNOWN 0x4000
40 #define NFC_ALTERED 0x8000
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);
122 /* Sysctl registration */
123 struct ctl_table_header *nf_register_sysctl_table(struct ctl_table *path,
124 struct ctl_table *table);
125 void nf_unregister_sysctl_table(struct ctl_table_header *header,
126 struct ctl_table *table);
127 extern struct ctl_table nf_net_netfilter_sysctl_path[];
128 extern struct ctl_table nf_net_ipv4_netfilter_sysctl_path[];
129 #endif /* CONFIG_SYSCTL */
131 extern struct list_head nf_hooks[NPROTO][NF_MAX_HOOKS];
133 /* those NF_LOG_* defines and struct nf_loginfo are legacy definitios that will
134 * disappear once iptables is replaced with pkttables. Please DO NOT use them
135 * for any new code! */
136 #define NF_LOG_TCPSEQ 0x01 /* Log TCP sequence numbers */
137 #define NF_LOG_TCPOPT 0x02 /* Log TCP options */
138 #define NF_LOG_IPOPT 0x04 /* Log IP options */
139 #define NF_LOG_UID 0x08 /* Log UID owning local socket */
140 #define NF_LOG_MASK 0x0f
142 #define NF_LOG_TYPE_LOG 0x01
143 #define NF_LOG_TYPE_ULOG 0x02
151 u_int16_t qthreshold;
160 typedef void nf_logfn(unsigned int pf,
161 unsigned int hooknum,
162 const struct sk_buff *skb,
163 const struct net_device *in,
164 const struct net_device *out,
165 const struct nf_loginfo *li,
174 /* Function to register/unregister log function. */
175 int nf_log_register(int pf, struct nf_logger *logger);
176 int nf_log_unregister_pf(int pf);
177 void nf_log_unregister_logger(struct nf_logger *logger);
179 /* Calls the registered backend logging function */
180 void nf_log_packet(int pf,
181 unsigned int hooknum,
182 const struct sk_buff *skb,
183 const struct net_device *in,
184 const struct net_device *out,
185 struct nf_loginfo *li,
186 const char *fmt, ...);
188 int nf_hook_slow(int pf, unsigned int hook, struct sk_buff **pskb,
189 struct net_device *indev, struct net_device *outdev,
190 int (*okfn)(struct sk_buff *), int thresh);
193 * nf_hook_thresh - call a netfilter hook
195 * Returns 1 if the hook has allowed the packet to pass. The function
196 * okfn must be invoked by the caller in this case. Any other return
197 * value indicates the packet has been consumed by the hook.
199 static inline int nf_hook_thresh(int pf, unsigned int hook,
200 struct sk_buff **pskb,
201 struct net_device *indev,
202 struct net_device *outdev,
203 int (*okfn)(struct sk_buff *), int thresh,
208 #ifndef CONFIG_NETFILTER_DEBUG
209 if (list_empty(&nf_hooks[pf][hook]))
212 return nf_hook_slow(pf, hook, pskb, indev, outdev, okfn, thresh);
215 static inline int nf_hook(int pf, unsigned int hook, struct sk_buff **pskb,
216 struct net_device *indev, struct net_device *outdev,
217 int (*okfn)(struct sk_buff *))
219 return nf_hook_thresh(pf, hook, pskb, indev, outdev, okfn, INT_MIN, 1);
222 /* Activate hook; either okfn or kfree_skb called, unless a hook
223 returns NF_STOLEN (in which case, it's up to the hook to deal with
226 Returns -ERRNO if packet dropped. Zero means queued, stolen or
231 > I don't want nf_hook to return anything because people might forget
232 > about async and trust the return value to mean "packet was ok".
235 Just document it clearly, then you can expect some sense from kernel
239 /* This is gross, but inline doesn't cut it for avoiding the function
240 call in fast path: gcc doesn't inline (needs value tracking?). --RR */
242 /* HX: It's slightly less gross now. */
244 #define NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, thresh) \
246 if ((__ret=nf_hook_thresh(pf, hook, &(skb), indev, outdev, okfn, thresh, 1)) == 1)\
247 __ret = (okfn)(skb); \
250 #define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond) \
252 if ((__ret=nf_hook_thresh(pf, hook, &(skb), indev, outdev, okfn, INT_MIN, cond)) == 1)\
253 __ret = (okfn)(skb); \
256 #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) \
257 NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, INT_MIN)
259 /* Call setsockopt() */
260 int nf_setsockopt(struct sock *sk, int pf, int optval, char __user *opt,
262 int nf_getsockopt(struct sock *sk, int pf, int optval, char __user *opt,
265 int compat_nf_setsockopt(struct sock *sk, int pf, int optval,
266 char __user *opt, int len);
267 int compat_nf_getsockopt(struct sock *sk, int pf, int optval,
268 char __user *opt, int *len);
271 struct nf_queue_handler {
272 int (*outfn)(struct sk_buff *skb, struct nf_info *info,
273 unsigned int queuenum, void *data);
277 extern int nf_register_queue_handler(int pf,
278 struct nf_queue_handler *qh);
279 extern int nf_unregister_queue_handler(int pf);
280 extern void nf_unregister_queue_handlers(struct nf_queue_handler *qh);
281 extern void nf_reinject(struct sk_buff *skb,
282 struct nf_info *info,
283 unsigned int verdict);
285 extern void (*ip_ct_attach)(struct sk_buff *, struct sk_buff *);
286 extern void nf_ct_attach(struct sk_buff *, struct sk_buff *);
288 /* FIXME: Before cache is ever used, this must be implemented for real. */
289 extern void nf_invalidate_cache(int pf);
291 /* Call this before modifying an existing packet: ensures it is
292 modifiable and linear to the point you care about (writable_len).
293 Returns true or false. */
294 extern int skb_make_writable(struct sk_buff **pskb, unsigned int writable_len);
296 static inline void nf_csum_replace4(__sum16 *sum, __be32 from, __be32 to)
298 __be32 diff[] = { ~from, to };
300 *sum = csum_fold(csum_partial((char *)diff, sizeof(diff), ~csum_unfold(*sum)));
303 static inline void nf_csum_replace2(__sum16 *sum, __be16 from, __be16 to)
305 nf_csum_replace4(sum, (__force __be32)from, (__force __be32)to);
308 extern void nf_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb,
309 __be32 from, __be32 to, int pseudohdr);
311 static inline void nf_proto_csum_replace2(__sum16 *sum, struct sk_buff *skb,
312 __be16 from, __be16 to, int pseudohdr)
314 nf_proto_csum_replace4(sum, skb, (__force __be32)from,
315 (__force __be32)to, pseudohdr);
319 unsigned short family;
320 __sum16 (*checksum)(struct sk_buff *skb, unsigned int hook,
321 unsigned int dataoff, u_int8_t protocol);
322 void (*saveroute)(const struct sk_buff *skb,
323 struct nf_info *info);
324 int (*reroute)(struct sk_buff **skb,
325 const struct nf_info *info);
329 extern struct nf_afinfo *nf_afinfo[];
330 static inline struct nf_afinfo *nf_get_afinfo(unsigned short family)
332 return rcu_dereference(nf_afinfo[family]);
335 static inline __sum16
336 nf_checksum(struct sk_buff *skb, unsigned int hook, unsigned int dataoff,
337 u_int8_t protocol, unsigned short family)
339 struct nf_afinfo *afinfo;
343 afinfo = nf_get_afinfo(family);
345 csum = afinfo->checksum(skb, hook, dataoff, protocol);
350 extern int nf_register_afinfo(struct nf_afinfo *afinfo);
351 extern void nf_unregister_afinfo(struct nf_afinfo *afinfo);
353 #define nf_info_reroute(x) ((void *)x + sizeof(struct nf_info))
355 #include <net/flow.h>
356 extern void (*ip_nat_decode_session)(struct sk_buff *, struct flowi *);
359 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, int family)
361 #if defined(CONFIG_IP_NF_NAT_NEEDED) || defined(CONFIG_NF_NAT_NEEDED)
362 void (*decodefn)(struct sk_buff *, struct flowi *);
364 if (family == AF_INET && (decodefn = ip_nat_decode_session) != NULL)
369 #ifdef CONFIG_PROC_FS
370 #include <linux/proc_fs.h>
371 extern struct proc_dir_entry *proc_net_netfilter;
374 #else /* !CONFIG_NETFILTER */
375 #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) (okfn)(skb)
376 #define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond) (okfn)(skb)
377 static inline int nf_hook_thresh(int pf, unsigned int hook,
378 struct sk_buff **pskb,
379 struct net_device *indev,
380 struct net_device *outdev,
381 int (*okfn)(struct sk_buff *), int thresh,
386 static inline int nf_hook(int pf, unsigned int hook, struct sk_buff **pskb,
387 struct net_device *indev, struct net_device *outdev,
388 int (*okfn)(struct sk_buff *))
392 static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
395 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, int family) {}
396 #endif /*CONFIG_NETFILTER*/
398 #endif /*__KERNEL__*/
399 #endif /*__LINUX_NETFILTER_H*/