1 #ifndef __LINUX_NETFILTER_H
2 #define __LINUX_NETFILTER_H
5 #include <linux/init.h>
6 #include <linux/skbuff.h>
10 #include <linux/in6.h>
11 #include <linux/wait.h>
12 #include <linux/list.h>
14 #include <linux/types.h>
15 #include <linux/compiler.h>
17 /* Responses from hook functions. */
24 #define NF_MAX_VERDICT NF_STOP
26 /* we overload the higher bits for encoding auxiliary data such as the queue
27 * number. Not nice, but better than additional function arguments. */
28 #define NF_VERDICT_MASK 0x0000ffff
29 #define NF_VERDICT_BITS 16
31 #define NF_VERDICT_QMASK 0xffff0000
32 #define NF_VERDICT_QBITS 16
34 #define NF_QUEUE_NR(x) ((((x) << NF_VERDICT_BITS) & NF_VERDICT_QMASK) | NF_QUEUE)
36 /* only for userspace compatibility */
38 /* Generic cache responses from hook functions.
39 <= 0x2000 is used for protocol-flags. */
40 #define NFC_UNKNOWN 0x4000
41 #define NFC_ALTERED 0x8000
72 #ifdef CONFIG_NETFILTER
74 static inline int nf_inet_addr_cmp(const union nf_inet_addr *a1,
75 const union nf_inet_addr *a2)
77 return a1->all[0] == a2->all[0] &&
78 a1->all[1] == a2->all[1] &&
79 a1->all[2] == a2->all[2] &&
80 a1->all[3] == a2->all[3];
83 extern void netfilter_init(void);
85 /* Largest hook number + 1 */
86 #define NF_MAX_HOOKS 8
90 typedef unsigned int nf_hookfn(unsigned int hooknum,
92 const struct net_device *in,
93 const struct net_device *out,
94 int (*okfn)(struct sk_buff *));
97 struct list_head list;
99 /* User fills in from here down. */
101 struct module *owner;
103 unsigned int hooknum;
104 /* Hooks are ordered in ascending priority. */
108 struct nf_sockopt_ops {
109 struct list_head list;
113 /* Non-inclusive ranges: use 0/0/NULL to never get called. */
116 int (*set)(struct sock *sk, int optval, void __user *user, unsigned int len);
117 int (*compat_set)(struct sock *sk, int optval,
118 void __user *user, unsigned int len);
122 int (*get)(struct sock *sk, int optval, void __user *user, int *len);
123 int (*compat_get)(struct sock *sk, int optval,
124 void __user *user, int *len);
126 /* Use the module struct to lock set/get code in place */
127 struct module *owner;
130 /* Function to register/unregister hook points. */
131 int nf_register_hook(struct nf_hook_ops *reg);
132 void nf_unregister_hook(struct nf_hook_ops *reg);
133 int nf_register_hooks(struct nf_hook_ops *reg, unsigned int n);
134 void nf_unregister_hooks(struct nf_hook_ops *reg, unsigned int n);
136 /* Functions to register get/setsockopt ranges (non-inclusive). You
137 need to check permissions yourself! */
138 int nf_register_sockopt(struct nf_sockopt_ops *reg);
139 void nf_unregister_sockopt(struct nf_sockopt_ops *reg);
142 /* Sysctl registration */
143 extern struct ctl_path nf_net_netfilter_sysctl_path[];
144 extern struct ctl_path nf_net_ipv4_netfilter_sysctl_path[];
145 #endif /* CONFIG_SYSCTL */
147 extern struct list_head nf_hooks[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
149 int nf_hook_slow(u_int8_t pf, unsigned int hook, struct sk_buff *skb,
150 struct net_device *indev, struct net_device *outdev,
151 int (*okfn)(struct sk_buff *), int thresh);
154 * nf_hook_thresh - call a netfilter hook
156 * Returns 1 if the hook has allowed the packet to pass. The function
157 * okfn must be invoked by the caller in this case. Any other return
158 * value indicates the packet has been consumed by the hook.
160 static inline int nf_hook_thresh(u_int8_t pf, unsigned int hook,
162 struct net_device *indev,
163 struct net_device *outdev,
164 int (*okfn)(struct sk_buff *), int thresh,
169 #ifndef CONFIG_NETFILTER_DEBUG
170 if (list_empty(&nf_hooks[pf][hook]))
173 return nf_hook_slow(pf, hook, skb, indev, outdev, okfn, thresh);
176 static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sk_buff *skb,
177 struct net_device *indev, struct net_device *outdev,
178 int (*okfn)(struct sk_buff *))
180 return nf_hook_thresh(pf, hook, skb, indev, outdev, okfn, INT_MIN, 1);
183 /* Activate hook; either okfn or kfree_skb called, unless a hook
184 returns NF_STOLEN (in which case, it's up to the hook to deal with
187 Returns -ERRNO if packet dropped. Zero means queued, stolen or
192 > I don't want nf_hook to return anything because people might forget
193 > about async and trust the return value to mean "packet was ok".
196 Just document it clearly, then you can expect some sense from kernel
200 /* This is gross, but inline doesn't cut it for avoiding the function
201 call in fast path: gcc doesn't inline (needs value tracking?). --RR */
203 /* HX: It's slightly less gross now. */
205 #define NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, thresh) \
207 if ((__ret=nf_hook_thresh(pf, hook, (skb), indev, outdev, okfn, thresh, 1)) == 1)\
208 __ret = (okfn)(skb); \
211 #define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond) \
213 if ((__ret=nf_hook_thresh(pf, hook, (skb), indev, outdev, okfn, INT_MIN, cond)) == 1)\
214 __ret = (okfn)(skb); \
217 #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) \
218 NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, INT_MIN)
220 /* Call setsockopt() */
221 int nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
223 int nf_getsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
226 int compat_nf_setsockopt(struct sock *sk, u_int8_t pf, int optval,
227 char __user *opt, unsigned int len);
228 int compat_nf_getsockopt(struct sock *sk, u_int8_t pf, int optval,
229 char __user *opt, int *len);
231 /* Call this before modifying an existing packet: ensures it is
232 modifiable and linear to the point you care about (writable_len).
233 Returns true or false. */
234 extern int skb_make_writable(struct sk_buff *skb, unsigned int writable_len);
237 struct nf_queue_entry;
240 unsigned short family;
241 __sum16 (*checksum)(struct sk_buff *skb, unsigned int hook,
242 unsigned int dataoff, u_int8_t protocol);
243 __sum16 (*checksum_partial)(struct sk_buff *skb,
245 unsigned int dataoff,
248 int (*route)(struct dst_entry **dst, struct flowi *fl);
249 void (*saveroute)(const struct sk_buff *skb,
250 struct nf_queue_entry *entry);
251 int (*reroute)(struct sk_buff *skb,
252 const struct nf_queue_entry *entry);
256 extern const struct nf_afinfo *nf_afinfo[NFPROTO_NUMPROTO];
257 static inline const struct nf_afinfo *nf_get_afinfo(unsigned short family)
259 return rcu_dereference(nf_afinfo[family]);
262 static inline __sum16
263 nf_checksum(struct sk_buff *skb, unsigned int hook, unsigned int dataoff,
264 u_int8_t protocol, unsigned short family)
266 const struct nf_afinfo *afinfo;
270 afinfo = nf_get_afinfo(family);
272 csum = afinfo->checksum(skb, hook, dataoff, protocol);
277 static inline __sum16
278 nf_checksum_partial(struct sk_buff *skb, unsigned int hook,
279 unsigned int dataoff, unsigned int len,
280 u_int8_t protocol, unsigned short family)
282 const struct nf_afinfo *afinfo;
286 afinfo = nf_get_afinfo(family);
288 csum = afinfo->checksum_partial(skb, hook, dataoff, len,
294 extern int nf_register_afinfo(const struct nf_afinfo *afinfo);
295 extern void nf_unregister_afinfo(const struct nf_afinfo *afinfo);
297 #include <net/flow.h>
298 extern void (*ip_nat_decode_session)(struct sk_buff *, struct flowi *);
301 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
303 #ifdef CONFIG_NF_NAT_NEEDED
304 void (*decodefn)(struct sk_buff *, struct flowi *);
306 if (family == AF_INET) {
308 decodefn = rcu_dereference(ip_nat_decode_session);
316 #ifdef CONFIG_PROC_FS
317 #include <linux/proc_fs.h>
318 extern struct proc_dir_entry *proc_net_netfilter;
321 #else /* !CONFIG_NETFILTER */
322 #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) (okfn)(skb)
323 #define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond) (okfn)(skb)
324 static inline int nf_hook_thresh(u_int8_t pf, unsigned int hook,
326 struct net_device *indev,
327 struct net_device *outdev,
328 int (*okfn)(struct sk_buff *), int thresh,
333 static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sk_buff *skb,
334 struct net_device *indev, struct net_device *outdev,
335 int (*okfn)(struct sk_buff *))
341 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
344 #endif /*CONFIG_NETFILTER*/
346 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
347 extern void (*ip_ct_attach)(struct sk_buff *, struct sk_buff *);
348 extern void nf_ct_attach(struct sk_buff *, struct sk_buff *);
349 extern void (*nf_ct_destroy)(struct nf_conntrack *);
351 static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
354 #endif /*__KERNEL__*/
355 #endif /*__LINUX_NETFILTER_H*/