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 struct list_head *hook_list;
58 int (*okfn)(struct sock *, struct sk_buff *);
61 static inline void nf_hook_state_init(struct nf_hook_state *p,
62 struct list_head *hook_list,
64 int thresh, u_int8_t pf,
65 struct net_device *indev,
66 struct net_device *outdev,
68 int (*okfn)(struct sock *, struct sk_buff *))
76 p->hook_list = hook_list;
80 typedef unsigned int nf_hookfn(const struct nf_hook_ops *ops,
82 const struct nf_hook_state *state);
85 struct list_head list;
87 /* User fills in from here down. */
89 struct net_device *dev;
94 /* Hooks are ordered in ascending priority. */
98 struct nf_sockopt_ops {
99 struct list_head list;
103 /* Non-inclusive ranges: use 0/0/NULL to never get called. */
106 int (*set)(struct sock *sk, int optval, void __user *user, unsigned int len);
108 int (*compat_set)(struct sock *sk, int optval,
109 void __user *user, unsigned int len);
113 int (*get)(struct sock *sk, int optval, void __user *user, int *len);
115 int (*compat_get)(struct sock *sk, int optval,
116 void __user *user, int *len);
118 /* Use the module struct to lock set/get code in place */
119 struct module *owner;
122 /* Function to register/unregister hook points. */
123 int nf_register_hook(struct nf_hook_ops *reg);
124 void nf_unregister_hook(struct nf_hook_ops *reg);
125 int nf_register_hooks(struct nf_hook_ops *reg, unsigned int n);
126 void nf_unregister_hooks(struct nf_hook_ops *reg, unsigned int n);
128 /* Functions to register get/setsockopt ranges (non-inclusive). You
129 need to check permissions yourself! */
130 int nf_register_sockopt(struct nf_sockopt_ops *reg);
131 void nf_unregister_sockopt(struct nf_sockopt_ops *reg);
133 extern struct list_head nf_hooks[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
135 #ifdef HAVE_JUMP_LABEL
136 extern struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
138 static inline bool nf_hook_list_active(struct list_head *nf_hook_list,
139 u_int8_t pf, unsigned int hook)
141 if (__builtin_constant_p(pf) &&
142 __builtin_constant_p(hook))
143 return static_key_false(&nf_hooks_needed[pf][hook]);
145 return !list_empty(nf_hook_list);
148 static inline bool nf_hook_list_active(struct list_head *nf_hook_list,
149 u_int8_t pf, unsigned int hook)
151 return !list_empty(nf_hook_list);
155 static inline bool nf_hooks_active(u_int8_t pf, unsigned int hook)
157 return nf_hook_list_active(&nf_hooks[pf][hook], pf, hook);
160 int nf_hook_slow(struct sk_buff *skb, struct nf_hook_state *state);
163 * nf_hook_thresh - call a netfilter hook
165 * Returns 1 if the hook has allowed the packet to pass. The function
166 * okfn must be invoked by the caller in this case. Any other return
167 * value indicates the packet has been consumed by the hook.
169 static inline int nf_hook_thresh(u_int8_t pf, unsigned int hook,
172 struct net_device *indev,
173 struct net_device *outdev,
174 int (*okfn)(struct sock *, struct sk_buff *),
177 if (nf_hooks_active(pf, hook)) {
178 struct nf_hook_state state;
180 nf_hook_state_init(&state, &nf_hooks[pf][hook], hook, thresh,
181 pf, indev, outdev, sk, okfn);
182 return nf_hook_slow(skb, &state);
187 static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sock *sk,
188 struct sk_buff *skb, struct net_device *indev,
189 struct net_device *outdev,
190 int (*okfn)(struct sock *, struct sk_buff *))
192 return nf_hook_thresh(pf, hook, sk, skb, indev, outdev, okfn, INT_MIN);
195 /* Activate hook; either okfn or kfree_skb called, unless a hook
196 returns NF_STOLEN (in which case, it's up to the hook to deal with
199 Returns -ERRNO if packet dropped. Zero means queued, stolen or
204 > I don't want nf_hook to return anything because people might forget
205 > about async and trust the return value to mean "packet was ok".
208 Just document it clearly, then you can expect some sense from kernel
213 NF_HOOK_THRESH(uint8_t pf, unsigned int hook, struct sock *sk,
214 struct sk_buff *skb, struct net_device *in,
215 struct net_device *out,
216 int (*okfn)(struct sock *, struct sk_buff *), int thresh)
218 int ret = nf_hook_thresh(pf, hook, sk, skb, in, out, okfn, thresh);
225 NF_HOOK_COND(uint8_t pf, unsigned int hook, struct sock *sk,
226 struct sk_buff *skb, struct net_device *in, struct net_device *out,
227 int (*okfn)(struct sock *, struct sk_buff *), bool cond)
232 ((ret = nf_hook_thresh(pf, hook, sk, skb, in, out, okfn, INT_MIN)) == 1))
238 NF_HOOK(uint8_t pf, unsigned int hook, struct sock *sk, struct sk_buff *skb,
239 struct net_device *in, struct net_device *out,
240 int (*okfn)(struct sock *, struct sk_buff *))
242 return NF_HOOK_THRESH(pf, hook, sk, skb, in, out, okfn, INT_MIN);
245 /* Call setsockopt() */
246 int nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
248 int nf_getsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
251 int compat_nf_setsockopt(struct sock *sk, u_int8_t pf, int optval,
252 char __user *opt, unsigned int len);
253 int compat_nf_getsockopt(struct sock *sk, u_int8_t pf, int optval,
254 char __user *opt, int *len);
257 /* Call this before modifying an existing packet: ensures it is
258 modifiable and linear to the point you care about (writable_len).
259 Returns true or false. */
260 int skb_make_writable(struct sk_buff *skb, unsigned int writable_len);
263 struct nf_queue_entry;
266 unsigned short family;
267 __sum16 (*checksum)(struct sk_buff *skb, unsigned int hook,
268 unsigned int dataoff, u_int8_t protocol);
269 __sum16 (*checksum_partial)(struct sk_buff *skb,
271 unsigned int dataoff,
274 int (*route)(struct net *net, struct dst_entry **dst,
275 struct flowi *fl, bool strict);
276 void (*saveroute)(const struct sk_buff *skb,
277 struct nf_queue_entry *entry);
278 int (*reroute)(struct sk_buff *skb,
279 const struct nf_queue_entry *entry);
283 extern const struct nf_afinfo __rcu *nf_afinfo[NFPROTO_NUMPROTO];
284 static inline const struct nf_afinfo *nf_get_afinfo(unsigned short family)
286 return rcu_dereference(nf_afinfo[family]);
289 static inline __sum16
290 nf_checksum(struct sk_buff *skb, unsigned int hook, unsigned int dataoff,
291 u_int8_t protocol, unsigned short family)
293 const struct nf_afinfo *afinfo;
297 afinfo = nf_get_afinfo(family);
299 csum = afinfo->checksum(skb, hook, dataoff, protocol);
304 static inline __sum16
305 nf_checksum_partial(struct sk_buff *skb, unsigned int hook,
306 unsigned int dataoff, unsigned int len,
307 u_int8_t protocol, unsigned short family)
309 const struct nf_afinfo *afinfo;
313 afinfo = nf_get_afinfo(family);
315 csum = afinfo->checksum_partial(skb, hook, dataoff, len,
321 int nf_register_afinfo(const struct nf_afinfo *afinfo);
322 void nf_unregister_afinfo(const struct nf_afinfo *afinfo);
324 #include <net/flow.h>
325 extern void (*nf_nat_decode_session_hook)(struct sk_buff *, struct flowi *);
328 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
330 #ifdef CONFIG_NF_NAT_NEEDED
331 void (*decodefn)(struct sk_buff *, struct flowi *);
334 decodefn = rcu_dereference(nf_nat_decode_session_hook);
341 #else /* !CONFIG_NETFILTER */
342 #define NF_HOOK(pf, hook, sk, skb, indev, outdev, okfn) (okfn)(sk, skb)
343 #define NF_HOOK_COND(pf, hook, sk, skb, indev, outdev, okfn, cond) (okfn)(sk, skb)
344 static inline int nf_hook_thresh(u_int8_t pf, unsigned int hook,
347 struct net_device *indev,
348 struct net_device *outdev,
349 int (*okfn)(struct sock *sk, struct sk_buff *), int thresh)
351 return okfn(sk, skb);
353 static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sock *sk,
354 struct sk_buff *skb, struct net_device *indev,
355 struct net_device *outdev,
356 int (*okfn)(struct sock *, struct sk_buff *))
362 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
365 #endif /*CONFIG_NETFILTER*/
367 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
368 extern void (*ip_ct_attach)(struct sk_buff *, const struct sk_buff *) __rcu;
369 void nf_ct_attach(struct sk_buff *, const struct sk_buff *);
370 extern void (*nf_ct_destroy)(struct nf_conntrack *) __rcu;
373 enum ip_conntrack_info;
377 size_t (*build_size)(const struct nf_conn *ct);
378 int (*build)(struct sk_buff *skb, struct nf_conn *ct);
379 int (*parse)(const struct nlattr *attr, struct nf_conn *ct);
380 int (*attach_expect)(const struct nlattr *attr, struct nf_conn *ct,
381 u32 portid, u32 report);
382 void (*seq_adjust)(struct sk_buff *skb, struct nf_conn *ct,
383 enum ip_conntrack_info ctinfo, s32 off);
385 extern struct nfq_ct_hook __rcu *nfq_ct_hook;
387 static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
390 #endif /*__LINUX_NETFILTER_H*/