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
47 typedef unsigned int nf_hookfn(const struct nf_hook_ops *ops,
49 const struct net_device *in,
50 const struct net_device *out,
51 int (*okfn)(struct sk_buff *));
54 struct list_head list;
56 /* User fills in from here down. */
62 /* Hooks are ordered in ascending priority. */
66 struct nf_sockopt_ops {
67 struct list_head list;
71 /* Non-inclusive ranges: use 0/0/NULL to never get called. */
74 int (*set)(struct sock *sk, int optval, void __user *user, unsigned int len);
76 int (*compat_set)(struct sock *sk, int optval,
77 void __user *user, unsigned int len);
81 int (*get)(struct sock *sk, int optval, void __user *user, int *len);
83 int (*compat_get)(struct sock *sk, int optval,
84 void __user *user, int *len);
86 /* Use the module struct to lock set/get code in place */
90 /* Function to register/unregister hook points. */
91 int nf_register_hook(struct nf_hook_ops *reg);
92 void nf_unregister_hook(struct nf_hook_ops *reg);
93 int nf_register_hooks(struct nf_hook_ops *reg, unsigned int n);
94 void nf_unregister_hooks(struct nf_hook_ops *reg, unsigned int n);
96 /* Functions to register get/setsockopt ranges (non-inclusive). You
97 need to check permissions yourself! */
98 int nf_register_sockopt(struct nf_sockopt_ops *reg);
99 void nf_unregister_sockopt(struct nf_sockopt_ops *reg);
101 extern struct list_head nf_hooks[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
103 #ifdef HAVE_JUMP_LABEL
104 extern struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
106 static inline bool nf_hooks_active(u_int8_t pf, unsigned int hook)
108 if (__builtin_constant_p(pf) &&
109 __builtin_constant_p(hook))
110 return static_key_false(&nf_hooks_needed[pf][hook]);
112 return !list_empty(&nf_hooks[pf][hook]);
115 static inline bool nf_hooks_active(u_int8_t pf, unsigned int hook)
117 return !list_empty(&nf_hooks[pf][hook]);
121 int nf_hook_slow(u_int8_t pf, unsigned int hook, struct sk_buff *skb,
122 struct net_device *indev, struct net_device *outdev,
123 int (*okfn)(struct sk_buff *), int thresh);
126 * nf_hook_thresh - call a netfilter hook
128 * Returns 1 if the hook has allowed the packet to pass. The function
129 * okfn must be invoked by the caller in this case. Any other return
130 * value indicates the packet has been consumed by the hook.
132 static inline int nf_hook_thresh(u_int8_t pf, unsigned int hook,
134 struct net_device *indev,
135 struct net_device *outdev,
136 int (*okfn)(struct sk_buff *), int thresh)
138 if (nf_hooks_active(pf, hook))
139 return nf_hook_slow(pf, hook, skb, indev, outdev, okfn, thresh);
143 static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sk_buff *skb,
144 struct net_device *indev, struct net_device *outdev,
145 int (*okfn)(struct sk_buff *))
147 return nf_hook_thresh(pf, hook, skb, indev, outdev, okfn, INT_MIN);
150 /* Activate hook; either okfn or kfree_skb called, unless a hook
151 returns NF_STOLEN (in which case, it's up to the hook to deal with
154 Returns -ERRNO if packet dropped. Zero means queued, stolen or
159 > I don't want nf_hook to return anything because people might forget
160 > about async and trust the return value to mean "packet was ok".
163 Just document it clearly, then you can expect some sense from kernel
168 NF_HOOK_THRESH(uint8_t pf, unsigned int hook, struct sk_buff *skb,
169 struct net_device *in, struct net_device *out,
170 int (*okfn)(struct sk_buff *), int thresh)
172 int ret = nf_hook_thresh(pf, hook, skb, in, out, okfn, thresh);
179 NF_HOOK_COND(uint8_t pf, unsigned int hook, struct sk_buff *skb,
180 struct net_device *in, struct net_device *out,
181 int (*okfn)(struct sk_buff *), bool cond)
186 ((ret = nf_hook_thresh(pf, hook, skb, in, out, okfn, INT_MIN)) == 1))
192 NF_HOOK(uint8_t pf, unsigned int hook, struct sk_buff *skb,
193 struct net_device *in, struct net_device *out,
194 int (*okfn)(struct sk_buff *))
196 return NF_HOOK_THRESH(pf, hook, skb, in, out, okfn, INT_MIN);
199 /* Call setsockopt() */
200 int nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
202 int nf_getsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
205 int compat_nf_setsockopt(struct sock *sk, u_int8_t pf, int optval,
206 char __user *opt, unsigned int len);
207 int compat_nf_getsockopt(struct sock *sk, u_int8_t pf, int optval,
208 char __user *opt, int *len);
211 /* Call this before modifying an existing packet: ensures it is
212 modifiable and linear to the point you care about (writable_len).
213 Returns true or false. */
214 int skb_make_writable(struct sk_buff *skb, unsigned int writable_len);
217 struct nf_queue_entry;
220 unsigned short family;
221 __sum16 (*checksum)(struct sk_buff *skb, unsigned int hook,
222 unsigned int dataoff, u_int8_t protocol);
223 __sum16 (*checksum_partial)(struct sk_buff *skb,
225 unsigned int dataoff,
228 int (*route)(struct net *net, struct dst_entry **dst,
229 struct flowi *fl, bool strict);
230 void (*saveroute)(const struct sk_buff *skb,
231 struct nf_queue_entry *entry);
232 int (*reroute)(struct sk_buff *skb,
233 const struct nf_queue_entry *entry);
237 extern const struct nf_afinfo __rcu *nf_afinfo[NFPROTO_NUMPROTO];
238 static inline const struct nf_afinfo *nf_get_afinfo(unsigned short family)
240 return rcu_dereference(nf_afinfo[family]);
243 static inline __sum16
244 nf_checksum(struct sk_buff *skb, unsigned int hook, unsigned int dataoff,
245 u_int8_t protocol, unsigned short family)
247 const struct nf_afinfo *afinfo;
251 afinfo = nf_get_afinfo(family);
253 csum = afinfo->checksum(skb, hook, dataoff, protocol);
258 static inline __sum16
259 nf_checksum_partial(struct sk_buff *skb, unsigned int hook,
260 unsigned int dataoff, unsigned int len,
261 u_int8_t protocol, unsigned short family)
263 const struct nf_afinfo *afinfo;
267 afinfo = nf_get_afinfo(family);
269 csum = afinfo->checksum_partial(skb, hook, dataoff, len,
275 int nf_register_afinfo(const struct nf_afinfo *afinfo);
276 void nf_unregister_afinfo(const struct nf_afinfo *afinfo);
278 #include <net/flow.h>
279 extern void (*nf_nat_decode_session_hook)(struct sk_buff *, struct flowi *);
282 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
284 #ifdef CONFIG_NF_NAT_NEEDED
285 void (*decodefn)(struct sk_buff *, struct flowi *);
288 decodefn = rcu_dereference(nf_nat_decode_session_hook);
295 #else /* !CONFIG_NETFILTER */
296 #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) (okfn)(skb)
297 #define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond) (okfn)(skb)
298 static inline int nf_hook_thresh(u_int8_t pf, unsigned int hook,
300 struct net_device *indev,
301 struct net_device *outdev,
302 int (*okfn)(struct sk_buff *), int thresh)
306 static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sk_buff *skb,
307 struct net_device *indev, struct net_device *outdev,
308 int (*okfn)(struct sk_buff *))
314 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
317 #endif /*CONFIG_NETFILTER*/
319 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
320 extern void (*ip_ct_attach)(struct sk_buff *, const struct sk_buff *) __rcu;
321 void nf_ct_attach(struct sk_buff *, const struct sk_buff *);
322 extern void (*nf_ct_destroy)(struct nf_conntrack *) __rcu;
325 enum ip_conntrack_info;
329 size_t (*build_size)(const struct nf_conn *ct);
330 int (*build)(struct sk_buff *skb, struct nf_conn *ct);
331 int (*parse)(const struct nlattr *attr, struct nf_conn *ct);
332 int (*attach_expect)(const struct nlattr *attr, struct nf_conn *ct,
333 u32 portid, u32 report);
334 void (*seq_adjust)(struct sk_buff *skb, struct nf_conn *ct,
335 enum ip_conntrack_info ctinfo, s32 off);
337 extern struct nfq_ct_hook __rcu *nfq_ct_hook;
339 static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
342 #endif /*__LINUX_NETFILTER_H*/