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 <linux/static_key.h>
13 #include <uapi/linux/netfilter.h>
14 #ifdef CONFIG_NETFILTER
15 static inline int NF_DROP_GETERR(int verdict)
17 return -(verdict >> NF_VERDICT_QBITS);
20 static inline int nf_inet_addr_cmp(const union nf_inet_addr *a1,
21 const union nf_inet_addr *a2)
23 return a1->all[0] == a2->all[0] &&
24 a1->all[1] == a2->all[1] &&
25 a1->all[2] == a2->all[2] &&
26 a1->all[3] == a2->all[3];
29 static inline void nf_inet_addr_mask(const union nf_inet_addr *a1,
30 union nf_inet_addr *result,
31 const union nf_inet_addr *mask)
33 result->all[0] = a1->all[0] & mask->all[0];
34 result->all[1] = a1->all[1] & mask->all[1];
35 result->all[2] = a1->all[2] & mask->all[2];
36 result->all[3] = a1->all[3] & mask->all[3];
39 int netfilter_init(void);
41 /* Largest hook number + 1 */
42 #define NF_MAX_HOOKS 8
50 struct nf_hook_state {
54 struct net_device *in;
55 struct net_device *out;
57 int (*okfn)(struct sock *, struct sk_buff *);
60 static inline void nf_hook_state_init(struct nf_hook_state *p,
62 int thresh, u_int8_t pf,
63 struct net_device *indev,
64 struct net_device *outdev,
66 int (*okfn)(struct sock *, struct sk_buff *))
77 typedef unsigned int nf_hookfn(const struct nf_hook_ops *ops,
79 const struct nf_hook_state *state);
82 struct list_head list;
84 /* User fills in from here down. */
90 /* Hooks are ordered in ascending priority. */
94 struct nf_sockopt_ops {
95 struct list_head list;
99 /* Non-inclusive ranges: use 0/0/NULL to never get called. */
102 int (*set)(struct sock *sk, int optval, void __user *user, unsigned int len);
104 int (*compat_set)(struct sock *sk, int optval,
105 void __user *user, unsigned int len);
109 int (*get)(struct sock *sk, int optval, void __user *user, int *len);
111 int (*compat_get)(struct sock *sk, int optval,
112 void __user *user, int *len);
114 /* Use the module struct to lock set/get code in place */
115 struct module *owner;
118 /* Function to register/unregister hook points. */
119 int nf_register_hook(struct nf_hook_ops *reg);
120 void nf_unregister_hook(struct nf_hook_ops *reg);
121 int nf_register_hooks(struct nf_hook_ops *reg, unsigned int n);
122 void nf_unregister_hooks(struct nf_hook_ops *reg, unsigned int n);
124 /* Functions to register get/setsockopt ranges (non-inclusive). You
125 need to check permissions yourself! */
126 int nf_register_sockopt(struct nf_sockopt_ops *reg);
127 void nf_unregister_sockopt(struct nf_sockopt_ops *reg);
129 extern struct list_head nf_hooks[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
131 #ifdef HAVE_JUMP_LABEL
132 extern struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
134 static inline bool nf_hooks_active(u_int8_t pf, unsigned int hook)
136 if (__builtin_constant_p(pf) &&
137 __builtin_constant_p(hook))
138 return static_key_false(&nf_hooks_needed[pf][hook]);
140 return !list_empty(&nf_hooks[pf][hook]);
143 static inline bool nf_hooks_active(u_int8_t pf, unsigned int hook)
145 return !list_empty(&nf_hooks[pf][hook]);
149 int nf_hook_slow(struct sk_buff *skb, struct nf_hook_state *state);
152 * nf_hook_thresh - call a netfilter hook
154 * Returns 1 if the hook has allowed the packet to pass. The function
155 * okfn must be invoked by the caller in this case. Any other return
156 * value indicates the packet has been consumed by the hook.
158 static inline int nf_hook_thresh(u_int8_t pf, unsigned int hook,
161 struct net_device *indev,
162 struct net_device *outdev,
163 int (*okfn)(struct sock *, struct sk_buff *),
166 if (nf_hooks_active(pf, hook)) {
167 struct nf_hook_state state;
169 nf_hook_state_init(&state, hook, thresh, pf,
170 indev, outdev, sk, okfn);
171 return nf_hook_slow(skb, &state);
176 static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sock *sk,
177 struct sk_buff *skb, struct net_device *indev,
178 struct net_device *outdev,
179 int (*okfn)(struct sock *, struct sk_buff *))
181 return nf_hook_thresh(pf, hook, sk, skb, indev, outdev, okfn, INT_MIN);
184 /* Activate hook; either okfn or kfree_skb called, unless a hook
185 returns NF_STOLEN (in which case, it's up to the hook to deal with
188 Returns -ERRNO if packet dropped. Zero means queued, stolen or
193 > I don't want nf_hook to return anything because people might forget
194 > about async and trust the return value to mean "packet was ok".
197 Just document it clearly, then you can expect some sense from kernel
202 NF_HOOK_THRESH(uint8_t pf, unsigned int hook, struct sock *sk,
203 struct sk_buff *skb, struct net_device *in,
204 struct net_device *out,
205 int (*okfn)(struct sock *, struct sk_buff *), int thresh)
207 int ret = nf_hook_thresh(pf, hook, sk, skb, in, out, okfn, thresh);
214 NF_HOOK_COND(uint8_t pf, unsigned int hook, struct sock *sk,
215 struct sk_buff *skb, struct net_device *in, struct net_device *out,
216 int (*okfn)(struct sock *, struct sk_buff *), bool cond)
221 ((ret = nf_hook_thresh(pf, hook, sk, skb, in, out, okfn, INT_MIN)) == 1))
227 NF_HOOK(uint8_t pf, unsigned int hook, struct sock *sk, struct sk_buff *skb,
228 struct net_device *in, struct net_device *out,
229 int (*okfn)(struct sock *, struct sk_buff *))
231 return NF_HOOK_THRESH(pf, hook, sk, skb, in, out, okfn, INT_MIN);
234 /* Call setsockopt() */
235 int nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
237 int nf_getsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
240 int compat_nf_setsockopt(struct sock *sk, u_int8_t pf, int optval,
241 char __user *opt, unsigned int len);
242 int compat_nf_getsockopt(struct sock *sk, u_int8_t pf, int optval,
243 char __user *opt, int *len);
246 /* Call this before modifying an existing packet: ensures it is
247 modifiable and linear to the point you care about (writable_len).
248 Returns true or false. */
249 int skb_make_writable(struct sk_buff *skb, unsigned int writable_len);
252 struct nf_queue_entry;
255 unsigned short family;
256 __sum16 (*checksum)(struct sk_buff *skb, unsigned int hook,
257 unsigned int dataoff, u_int8_t protocol);
258 __sum16 (*checksum_partial)(struct sk_buff *skb,
260 unsigned int dataoff,
263 int (*route)(struct net *net, struct dst_entry **dst,
264 struct flowi *fl, bool strict);
265 void (*saveroute)(const struct sk_buff *skb,
266 struct nf_queue_entry *entry);
267 int (*reroute)(struct sk_buff *skb,
268 const struct nf_queue_entry *entry);
272 extern const struct nf_afinfo __rcu *nf_afinfo[NFPROTO_NUMPROTO];
273 static inline const struct nf_afinfo *nf_get_afinfo(unsigned short family)
275 return rcu_dereference(nf_afinfo[family]);
278 static inline __sum16
279 nf_checksum(struct sk_buff *skb, unsigned int hook, unsigned int dataoff,
280 u_int8_t protocol, unsigned short family)
282 const struct nf_afinfo *afinfo;
286 afinfo = nf_get_afinfo(family);
288 csum = afinfo->checksum(skb, hook, dataoff, protocol);
293 static inline __sum16
294 nf_checksum_partial(struct sk_buff *skb, unsigned int hook,
295 unsigned int dataoff, unsigned int len,
296 u_int8_t protocol, unsigned short family)
298 const struct nf_afinfo *afinfo;
302 afinfo = nf_get_afinfo(family);
304 csum = afinfo->checksum_partial(skb, hook, dataoff, len,
310 int nf_register_afinfo(const struct nf_afinfo *afinfo);
311 void nf_unregister_afinfo(const struct nf_afinfo *afinfo);
313 #include <net/flow.h>
314 extern void (*nf_nat_decode_session_hook)(struct sk_buff *, struct flowi *);
317 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
319 #ifdef CONFIG_NF_NAT_NEEDED
320 void (*decodefn)(struct sk_buff *, struct flowi *);
323 decodefn = rcu_dereference(nf_nat_decode_session_hook);
330 #else /* !CONFIG_NETFILTER */
331 #define NF_HOOK(pf, hook, sk, skb, indev, outdev, okfn) (okfn)(sk, skb)
332 #define NF_HOOK_COND(pf, hook, sk, skb, indev, outdev, okfn, cond) (okfn)(sk, skb)
333 static inline int nf_hook_thresh(u_int8_t pf, unsigned int hook,
336 struct net_device *indev,
337 struct net_device *outdev,
338 int (*okfn)(struct sock *sk, struct sk_buff *), int thresh)
340 return okfn(sk, skb);
342 static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sock *sk,
343 struct sk_buff *skb, struct net_device *indev,
344 struct net_device *outdev,
345 int (*okfn)(struct sock *, struct sk_buff *))
351 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
354 #endif /*CONFIG_NETFILTER*/
356 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
357 extern void (*ip_ct_attach)(struct sk_buff *, const struct sk_buff *) __rcu;
358 void nf_ct_attach(struct sk_buff *, const struct sk_buff *);
359 extern void (*nf_ct_destroy)(struct nf_conntrack *) __rcu;
362 enum ip_conntrack_info;
366 size_t (*build_size)(const struct nf_conn *ct);
367 int (*build)(struct sk_buff *skb, struct nf_conn *ct);
368 int (*parse)(const struct nlattr *attr, struct nf_conn *ct);
369 int (*attach_expect)(const struct nlattr *attr, struct nf_conn *ct,
370 u32 portid, u32 report);
371 void (*seq_adjust)(struct sk_buff *skb, struct nf_conn *ct,
372 enum ip_conntrack_info ctinfo, s32 off);
374 extern struct nfq_ct_hook __rcu *nfq_ct_hook;
376 static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
379 #endif /*__LINUX_NETFILTER_H*/