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
48 struct nf_hook_state {
52 struct net_device *in;
53 struct net_device *out;
54 int (*okfn)(struct sk_buff *);
57 static inline void nf_hook_state_init(struct nf_hook_state *p,
59 int thresh, u_int8_t pf,
60 struct net_device *indev,
61 struct net_device *outdev,
62 int (*okfn)(struct sk_buff *))
72 typedef unsigned int nf_hookfn(const struct nf_hook_ops *ops,
74 const struct nf_hook_state *state);
77 struct list_head list;
79 /* User fills in from here down. */
85 /* Hooks are ordered in ascending priority. */
89 struct nf_sockopt_ops {
90 struct list_head list;
94 /* Non-inclusive ranges: use 0/0/NULL to never get called. */
97 int (*set)(struct sock *sk, int optval, void __user *user, unsigned int len);
99 int (*compat_set)(struct sock *sk, int optval,
100 void __user *user, unsigned int len);
104 int (*get)(struct sock *sk, int optval, void __user *user, int *len);
106 int (*compat_get)(struct sock *sk, int optval,
107 void __user *user, int *len);
109 /* Use the module struct to lock set/get code in place */
110 struct module *owner;
113 /* Function to register/unregister hook points. */
114 int nf_register_hook(struct nf_hook_ops *reg);
115 void nf_unregister_hook(struct nf_hook_ops *reg);
116 int nf_register_hooks(struct nf_hook_ops *reg, unsigned int n);
117 void nf_unregister_hooks(struct nf_hook_ops *reg, unsigned int n);
119 /* Functions to register get/setsockopt ranges (non-inclusive). You
120 need to check permissions yourself! */
121 int nf_register_sockopt(struct nf_sockopt_ops *reg);
122 void nf_unregister_sockopt(struct nf_sockopt_ops *reg);
124 extern struct list_head nf_hooks[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
126 #ifdef HAVE_JUMP_LABEL
127 extern struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
129 static inline bool nf_hooks_active(u_int8_t pf, unsigned int hook)
131 if (__builtin_constant_p(pf) &&
132 __builtin_constant_p(hook))
133 return static_key_false(&nf_hooks_needed[pf][hook]);
135 return !list_empty(&nf_hooks[pf][hook]);
138 static inline bool nf_hooks_active(u_int8_t pf, unsigned int hook)
140 return !list_empty(&nf_hooks[pf][hook]);
144 int nf_hook_slow(struct sk_buff *skb, struct nf_hook_state *state);
147 * nf_hook_thresh - call a netfilter hook
149 * Returns 1 if the hook has allowed the packet to pass. The function
150 * okfn must be invoked by the caller in this case. Any other return
151 * value indicates the packet has been consumed by the hook.
153 static inline int nf_hook_thresh(u_int8_t pf, unsigned int hook,
155 struct net_device *indev,
156 struct net_device *outdev,
157 int (*okfn)(struct sk_buff *), int thresh)
159 if (nf_hooks_active(pf, hook)) {
160 struct nf_hook_state state;
162 nf_hook_state_init(&state, hook, thresh, pf,
163 indev, outdev, okfn);
164 return nf_hook_slow(skb, &state);
169 static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sk_buff *skb,
170 struct net_device *indev, struct net_device *outdev,
171 int (*okfn)(struct sk_buff *))
173 return nf_hook_thresh(pf, hook, skb, indev, outdev, okfn, INT_MIN);
176 /* Activate hook; either okfn or kfree_skb called, unless a hook
177 returns NF_STOLEN (in which case, it's up to the hook to deal with
180 Returns -ERRNO if packet dropped. Zero means queued, stolen or
185 > I don't want nf_hook to return anything because people might forget
186 > about async and trust the return value to mean "packet was ok".
189 Just document it clearly, then you can expect some sense from kernel
194 NF_HOOK_THRESH(uint8_t pf, unsigned int hook, struct sk_buff *skb,
195 struct net_device *in, struct net_device *out,
196 int (*okfn)(struct sk_buff *), int thresh)
198 int ret = nf_hook_thresh(pf, hook, skb, in, out, okfn, thresh);
205 NF_HOOK_COND(uint8_t pf, unsigned int hook, struct sk_buff *skb,
206 struct net_device *in, struct net_device *out,
207 int (*okfn)(struct sk_buff *), bool cond)
212 ((ret = nf_hook_thresh(pf, hook, skb, in, out, okfn, INT_MIN)) == 1))
218 NF_HOOK(uint8_t pf, unsigned int hook, struct sk_buff *skb,
219 struct net_device *in, struct net_device *out,
220 int (*okfn)(struct sk_buff *))
222 return NF_HOOK_THRESH(pf, hook, skb, in, out, okfn, INT_MIN);
225 /* Call setsockopt() */
226 int nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
228 int nf_getsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
231 int compat_nf_setsockopt(struct sock *sk, u_int8_t pf, int optval,
232 char __user *opt, unsigned int len);
233 int compat_nf_getsockopt(struct sock *sk, u_int8_t pf, int optval,
234 char __user *opt, int *len);
237 /* Call this before modifying an existing packet: ensures it is
238 modifiable and linear to the point you care about (writable_len).
239 Returns true or false. */
240 int skb_make_writable(struct sk_buff *skb, unsigned int writable_len);
243 struct nf_queue_entry;
246 unsigned short family;
247 __sum16 (*checksum)(struct sk_buff *skb, unsigned int hook,
248 unsigned int dataoff, u_int8_t protocol);
249 __sum16 (*checksum_partial)(struct sk_buff *skb,
251 unsigned int dataoff,
254 int (*route)(struct net *net, struct dst_entry **dst,
255 struct flowi *fl, bool strict);
256 void (*saveroute)(const struct sk_buff *skb,
257 struct nf_queue_entry *entry);
258 int (*reroute)(struct sk_buff *skb,
259 const struct nf_queue_entry *entry);
263 extern const struct nf_afinfo __rcu *nf_afinfo[NFPROTO_NUMPROTO];
264 static inline const struct nf_afinfo *nf_get_afinfo(unsigned short family)
266 return rcu_dereference(nf_afinfo[family]);
269 static inline __sum16
270 nf_checksum(struct sk_buff *skb, unsigned int hook, unsigned int dataoff,
271 u_int8_t protocol, unsigned short family)
273 const struct nf_afinfo *afinfo;
277 afinfo = nf_get_afinfo(family);
279 csum = afinfo->checksum(skb, hook, dataoff, protocol);
284 static inline __sum16
285 nf_checksum_partial(struct sk_buff *skb, unsigned int hook,
286 unsigned int dataoff, unsigned int len,
287 u_int8_t protocol, unsigned short family)
289 const struct nf_afinfo *afinfo;
293 afinfo = nf_get_afinfo(family);
295 csum = afinfo->checksum_partial(skb, hook, dataoff, len,
301 int nf_register_afinfo(const struct nf_afinfo *afinfo);
302 void nf_unregister_afinfo(const struct nf_afinfo *afinfo);
304 #include <net/flow.h>
305 extern void (*nf_nat_decode_session_hook)(struct sk_buff *, struct flowi *);
308 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
310 #ifdef CONFIG_NF_NAT_NEEDED
311 void (*decodefn)(struct sk_buff *, struct flowi *);
314 decodefn = rcu_dereference(nf_nat_decode_session_hook);
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)
332 static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sk_buff *skb,
333 struct net_device *indev, struct net_device *outdev,
334 int (*okfn)(struct sk_buff *))
340 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
343 #endif /*CONFIG_NETFILTER*/
345 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
346 extern void (*ip_ct_attach)(struct sk_buff *, const struct sk_buff *) __rcu;
347 void nf_ct_attach(struct sk_buff *, const struct sk_buff *);
348 extern void (*nf_ct_destroy)(struct nf_conntrack *) __rcu;
351 enum ip_conntrack_info;
355 size_t (*build_size)(const struct nf_conn *ct);
356 int (*build)(struct sk_buff *skb, struct nf_conn *ct);
357 int (*parse)(const struct nlattr *attr, struct nf_conn *ct);
358 int (*attach_expect)(const struct nlattr *attr, struct nf_conn *ct,
359 u32 portid, u32 report);
360 void (*seq_adjust)(struct sk_buff *skb, struct nf_conn *ct,
361 enum ip_conntrack_info ctinfo, s32 off);
363 extern struct nfq_ct_hook __rcu *nfq_ct_hook;
365 static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
368 #endif /*__LINUX_NETFILTER_H*/