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 <uapi/linux/netfilter.h>
13 #ifdef CONFIG_NETFILTER
14 static inline int NF_DROP_GETERR(int verdict)
16 return -(verdict >> NF_VERDICT_QBITS);
19 static inline int nf_inet_addr_cmp(const union nf_inet_addr *a1,
20 const union nf_inet_addr *a2)
22 return a1->all[0] == a2->all[0] &&
23 a1->all[1] == a2->all[1] &&
24 a1->all[2] == a2->all[2] &&
25 a1->all[3] == a2->all[3];
28 static inline void nf_inet_addr_mask(const union nf_inet_addr *a1,
29 union nf_inet_addr *result,
30 const union nf_inet_addr *mask)
32 result->all[0] = a1->all[0] & mask->all[0];
33 result->all[1] = a1->all[1] & mask->all[1];
34 result->all[2] = a1->all[2] & mask->all[2];
35 result->all[3] = a1->all[3] & mask->all[3];
38 int netfilter_init(void);
40 /* Largest hook number + 1 */
41 #define NF_MAX_HOOKS 8
46 typedef unsigned int nf_hookfn(const struct nf_hook_ops *ops,
48 const struct net_device *in,
49 const struct net_device *out,
50 int (*okfn)(struct sk_buff *));
53 struct list_head list;
55 /* User fills in from here down. */
61 /* Hooks are ordered in ascending priority. */
65 struct nf_sockopt_ops {
66 struct list_head list;
70 /* Non-inclusive ranges: use 0/0/NULL to never get called. */
73 int (*set)(struct sock *sk, int optval, void __user *user, unsigned int len);
75 int (*compat_set)(struct sock *sk, int optval,
76 void __user *user, unsigned int len);
80 int (*get)(struct sock *sk, int optval, void __user *user, int *len);
82 int (*compat_get)(struct sock *sk, int optval,
83 void __user *user, int *len);
85 /* Use the module struct to lock set/get code in place */
89 /* Function to register/unregister hook points. */
90 int nf_register_hook(struct nf_hook_ops *reg);
91 void nf_unregister_hook(struct nf_hook_ops *reg);
92 int nf_register_hooks(struct nf_hook_ops *reg, unsigned int n);
93 void nf_unregister_hooks(struct nf_hook_ops *reg, unsigned int n);
95 /* Functions to register get/setsockopt ranges (non-inclusive). You
96 need to check permissions yourself! */
97 int nf_register_sockopt(struct nf_sockopt_ops *reg);
98 void nf_unregister_sockopt(struct nf_sockopt_ops *reg);
100 extern struct list_head nf_hooks[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
102 #if defined(CONFIG_JUMP_LABEL)
103 #include <linux/static_key.h>
104 extern struct static_key nf_hooks_needed[NFPROTO_NUMPROTO][NF_MAX_HOOKS];
105 static inline bool nf_hooks_active(u_int8_t pf, unsigned int hook)
107 if (__builtin_constant_p(pf) &&
108 __builtin_constant_p(hook))
109 return static_key_false(&nf_hooks_needed[pf][hook]);
111 return !list_empty(&nf_hooks[pf][hook]);
114 static inline bool nf_hooks_active(u_int8_t pf, unsigned int hook)
116 return !list_empty(&nf_hooks[pf][hook]);
120 int nf_hook_slow(u_int8_t pf, unsigned int hook, struct sk_buff *skb,
121 struct net_device *indev, struct net_device *outdev,
122 int (*okfn)(struct sk_buff *), int thresh);
125 * nf_hook_thresh - call a netfilter hook
127 * Returns 1 if the hook has allowed the packet to pass. The function
128 * okfn must be invoked by the caller in this case. Any other return
129 * value indicates the packet has been consumed by the hook.
131 static inline int nf_hook_thresh(u_int8_t pf, unsigned int hook,
133 struct net_device *indev,
134 struct net_device *outdev,
135 int (*okfn)(struct sk_buff *), int thresh)
137 if (nf_hooks_active(pf, hook))
138 return nf_hook_slow(pf, hook, skb, indev, outdev, okfn, thresh);
142 static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sk_buff *skb,
143 struct net_device *indev, struct net_device *outdev,
144 int (*okfn)(struct sk_buff *))
146 return nf_hook_thresh(pf, hook, skb, indev, outdev, okfn, INT_MIN);
149 /* Activate hook; either okfn or kfree_skb called, unless a hook
150 returns NF_STOLEN (in which case, it's up to the hook to deal with
153 Returns -ERRNO if packet dropped. Zero means queued, stolen or
158 > I don't want nf_hook to return anything because people might forget
159 > about async and trust the return value to mean "packet was ok".
162 Just document it clearly, then you can expect some sense from kernel
167 NF_HOOK_THRESH(uint8_t pf, unsigned int hook, struct sk_buff *skb,
168 struct net_device *in, struct net_device *out,
169 int (*okfn)(struct sk_buff *), int thresh)
171 int ret = nf_hook_thresh(pf, hook, skb, in, out, okfn, thresh);
178 NF_HOOK_COND(uint8_t pf, unsigned int hook, struct sk_buff *skb,
179 struct net_device *in, struct net_device *out,
180 int (*okfn)(struct sk_buff *), bool cond)
185 ((ret = nf_hook_thresh(pf, hook, skb, in, out, okfn, INT_MIN)) == 1))
191 NF_HOOK(uint8_t pf, unsigned int hook, struct sk_buff *skb,
192 struct net_device *in, struct net_device *out,
193 int (*okfn)(struct sk_buff *))
195 return NF_HOOK_THRESH(pf, hook, skb, in, out, okfn, INT_MIN);
198 /* Call setsockopt() */
199 int nf_setsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
201 int nf_getsockopt(struct sock *sk, u_int8_t pf, int optval, char __user *opt,
204 int compat_nf_setsockopt(struct sock *sk, u_int8_t pf, int optval,
205 char __user *opt, unsigned int len);
206 int compat_nf_getsockopt(struct sock *sk, u_int8_t pf, int optval,
207 char __user *opt, int *len);
210 /* Call this before modifying an existing packet: ensures it is
211 modifiable and linear to the point you care about (writable_len).
212 Returns true or false. */
213 int skb_make_writable(struct sk_buff *skb, unsigned int writable_len);
216 struct nf_queue_entry;
219 unsigned short family;
220 __sum16 (*checksum)(struct sk_buff *skb, unsigned int hook,
221 unsigned int dataoff, u_int8_t protocol);
222 __sum16 (*checksum_partial)(struct sk_buff *skb,
224 unsigned int dataoff,
227 int (*route)(struct net *net, struct dst_entry **dst,
228 struct flowi *fl, bool strict);
229 void (*saveroute)(const struct sk_buff *skb,
230 struct nf_queue_entry *entry);
231 int (*reroute)(struct sk_buff *skb,
232 const struct nf_queue_entry *entry);
236 extern const struct nf_afinfo __rcu *nf_afinfo[NFPROTO_NUMPROTO];
237 static inline const struct nf_afinfo *nf_get_afinfo(unsigned short family)
239 return rcu_dereference(nf_afinfo[family]);
242 static inline __sum16
243 nf_checksum(struct sk_buff *skb, unsigned int hook, unsigned int dataoff,
244 u_int8_t protocol, unsigned short family)
246 const struct nf_afinfo *afinfo;
250 afinfo = nf_get_afinfo(family);
252 csum = afinfo->checksum(skb, hook, dataoff, protocol);
257 static inline __sum16
258 nf_checksum_partial(struct sk_buff *skb, unsigned int hook,
259 unsigned int dataoff, unsigned int len,
260 u_int8_t protocol, unsigned short family)
262 const struct nf_afinfo *afinfo;
266 afinfo = nf_get_afinfo(family);
268 csum = afinfo->checksum_partial(skb, hook, dataoff, len,
274 int nf_register_afinfo(const struct nf_afinfo *afinfo);
275 void nf_unregister_afinfo(const struct nf_afinfo *afinfo);
277 #include <net/flow.h>
278 extern void (*nf_nat_decode_session_hook)(struct sk_buff *, struct flowi *);
281 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
283 #ifdef CONFIG_NF_NAT_NEEDED
284 void (*decodefn)(struct sk_buff *, struct flowi *);
287 decodefn = rcu_dereference(nf_nat_decode_session_hook);
294 #else /* !CONFIG_NETFILTER */
295 #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) (okfn)(skb)
296 #define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond) (okfn)(skb)
297 static inline int nf_hook_thresh(u_int8_t pf, unsigned int hook,
299 struct net_device *indev,
300 struct net_device *outdev,
301 int (*okfn)(struct sk_buff *), int thresh)
305 static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sk_buff *skb,
306 struct net_device *indev, struct net_device *outdev,
307 int (*okfn)(struct sk_buff *))
313 nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
316 #endif /*CONFIG_NETFILTER*/
318 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
319 extern void (*ip_ct_attach)(struct sk_buff *, const struct sk_buff *) __rcu;
320 void nf_ct_attach(struct sk_buff *, const struct sk_buff *);
321 extern void (*nf_ct_destroy)(struct nf_conntrack *) __rcu;
324 enum ip_conntrack_info;
328 size_t (*build_size)(const struct nf_conn *ct);
329 int (*build)(struct sk_buff *skb, struct nf_conn *ct);
330 int (*parse)(const struct nlattr *attr, struct nf_conn *ct);
331 int (*attach_expect)(const struct nlattr *attr, struct nf_conn *ct,
332 u32 portid, u32 report);
333 void (*seq_adjust)(struct sk_buff *skb, struct nf_conn *ct,
334 enum ip_conntrack_info ctinfo, s32 off);
336 extern struct nfq_ct_hook __rcu *nfq_ct_hook;
338 static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
341 #endif /*__LINUX_NETFILTER_H*/