Commit | Line | Data |
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1da177e4 LT |
1 | #ifndef __LINUX_NETFILTER_H |
2 | #define __LINUX_NETFILTER_H | |
3 | ||
4 | #ifdef __KERNEL__ | |
5 | #include <linux/init.h> | |
6 | #include <linux/types.h> | |
7 | #include <linux/skbuff.h> | |
8 | #include <linux/net.h> | |
9 | #include <linux/if.h> | |
2e3075a2 JE |
10 | #include <linux/in.h> |
11 | #include <linux/in6.h> | |
1da177e4 LT |
12 | #include <linux/wait.h> |
13 | #include <linux/list.h> | |
14 | #endif | |
15 | #include <linux/compiler.h> | |
16 | ||
17 | /* Responses from hook functions. */ | |
18 | #define NF_DROP 0 | |
19 | #define NF_ACCEPT 1 | |
20 | #define NF_STOLEN 2 | |
21 | #define NF_QUEUE 3 | |
22 | #define NF_REPEAT 4 | |
23 | #define NF_STOP 5 | |
24 | #define NF_MAX_VERDICT NF_STOP | |
25 | ||
0ab43f84 HW |
26 | /* we overload the higher bits for encoding auxiliary data such as the queue |
27 | * number. Not nice, but better than additional function arguments. */ | |
28 | #define NF_VERDICT_MASK 0x0000ffff | |
29 | #define NF_VERDICT_BITS 16 | |
30 | ||
31 | #define NF_VERDICT_QMASK 0xffff0000 | |
32 | #define NF_VERDICT_QBITS 16 | |
33 | ||
fbabbed8 | 34 | #define NF_QUEUE_NR(x) ((((x) << NF_VERDICT_BITS) & NF_VERDICT_QMASK) | NF_QUEUE) |
0ab43f84 | 35 | |
6869c4d8 HW |
36 | /* only for userspace compatibility */ |
37 | #ifndef __KERNEL__ | |
1da177e4 LT |
38 | /* Generic cache responses from hook functions. |
39 | <= 0x2000 is used for protocol-flags. */ | |
40 | #define NFC_UNKNOWN 0x4000 | |
41 | #define NFC_ALTERED 0x8000 | |
6869c4d8 | 42 | #endif |
1da177e4 | 43 | |
6e23ae2a PM |
44 | enum nf_inet_hooks { |
45 | NF_INET_PRE_ROUTING, | |
46 | NF_INET_LOCAL_IN, | |
47 | NF_INET_FORWARD, | |
48 | NF_INET_LOCAL_OUT, | |
49 | NF_INET_POST_ROUTING, | |
50 | NF_INET_NUMHOOKS | |
51 | }; | |
52 | ||
643a2c15 | 53 | union nf_inet_addr { |
7b33ed22 | 54 | __u32 all[4]; |
643a2c15 JE |
55 | __be32 ip; |
56 | __be32 ip6[4]; | |
2e3075a2 JE |
57 | struct in_addr in; |
58 | struct in6_addr in6; | |
643a2c15 JE |
59 | }; |
60 | ||
1da177e4 | 61 | #ifdef __KERNEL__ |
1da177e4 LT |
62 | #ifdef CONFIG_NETFILTER |
63 | ||
64 | extern void netfilter_init(void); | |
65 | ||
66 | /* Largest hook number + 1 */ | |
67 | #define NF_MAX_HOOKS 8 | |
68 | ||
69 | struct sk_buff; | |
70 | struct net_device; | |
71 | ||
72 | typedef unsigned int nf_hookfn(unsigned int hooknum, | |
3db05fea | 73 | struct sk_buff *skb, |
1da177e4 LT |
74 | const struct net_device *in, |
75 | const struct net_device *out, | |
76 | int (*okfn)(struct sk_buff *)); | |
77 | ||
78 | struct nf_hook_ops | |
79 | { | |
80 | struct list_head list; | |
81 | ||
82 | /* User fills in from here down. */ | |
83 | nf_hookfn *hook; | |
84 | struct module *owner; | |
85 | int pf; | |
86 | int hooknum; | |
87 | /* Hooks are ordered in ascending priority. */ | |
88 | int priority; | |
89 | }; | |
90 | ||
91 | struct nf_sockopt_ops | |
92 | { | |
93 | struct list_head list; | |
94 | ||
95 | int pf; | |
96 | ||
97 | /* Non-inclusive ranges: use 0/0/NULL to never get called. */ | |
98 | int set_optmin; | |
99 | int set_optmax; | |
100 | int (*set)(struct sock *sk, int optval, void __user *user, unsigned int len); | |
3fdadf7d DM |
101 | int (*compat_set)(struct sock *sk, int optval, |
102 | void __user *user, unsigned int len); | |
1da177e4 LT |
103 | |
104 | int get_optmin; | |
105 | int get_optmax; | |
106 | int (*get)(struct sock *sk, int optval, void __user *user, int *len); | |
3fdadf7d DM |
107 | int (*compat_get)(struct sock *sk, int optval, |
108 | void __user *user, int *len); | |
1da177e4 | 109 | |
16fcec35 NH |
110 | /* Use the module struct to lock set/get code in place */ |
111 | struct module *owner; | |
1da177e4 LT |
112 | }; |
113 | ||
1da177e4 LT |
114 | /* Function to register/unregister hook points. */ |
115 | int nf_register_hook(struct nf_hook_ops *reg); | |
116 | void nf_unregister_hook(struct nf_hook_ops *reg); | |
972d1cb1 PM |
117 | int nf_register_hooks(struct nf_hook_ops *reg, unsigned int n); |
118 | void nf_unregister_hooks(struct nf_hook_ops *reg, unsigned int n); | |
1da177e4 LT |
119 | |
120 | /* Functions to register get/setsockopt ranges (non-inclusive). You | |
121 | need to check permissions yourself! */ | |
122 | int nf_register_sockopt(struct nf_sockopt_ops *reg); | |
123 | void nf_unregister_sockopt(struct nf_sockopt_ops *reg); | |
124 | ||
d62f9ed4 PM |
125 | #ifdef CONFIG_SYSCTL |
126 | /* Sysctl registration */ | |
b3fd3ffe PE |
127 | extern struct ctl_path nf_net_netfilter_sysctl_path[]; |
128 | extern struct ctl_path nf_net_ipv4_netfilter_sysctl_path[]; | |
d62f9ed4 PM |
129 | #endif /* CONFIG_SYSCTL */ |
130 | ||
1da177e4 LT |
131 | extern struct list_head nf_hooks[NPROTO][NF_MAX_HOOKS]; |
132 | ||
3db05fea | 133 | int nf_hook_slow(int pf, unsigned int hook, struct sk_buff *skb, |
16a6677f PM |
134 | struct net_device *indev, struct net_device *outdev, |
135 | int (*okfn)(struct sk_buff *), int thresh); | |
136 | ||
137 | /** | |
138 | * nf_hook_thresh - call a netfilter hook | |
139 | * | |
140 | * Returns 1 if the hook has allowed the packet to pass. The function | |
141 | * okfn must be invoked by the caller in this case. Any other return | |
142 | * value indicates the packet has been consumed by the hook. | |
143 | */ | |
144 | static inline int nf_hook_thresh(int pf, unsigned int hook, | |
3db05fea | 145 | struct sk_buff *skb, |
16a6677f PM |
146 | struct net_device *indev, |
147 | struct net_device *outdev, | |
48d5cad8 PM |
148 | int (*okfn)(struct sk_buff *), int thresh, |
149 | int cond) | |
16a6677f | 150 | { |
48d5cad8 PM |
151 | if (!cond) |
152 | return 1; | |
16a6677f PM |
153 | #ifndef CONFIG_NETFILTER_DEBUG |
154 | if (list_empty(&nf_hooks[pf][hook])) | |
155 | return 1; | |
156 | #endif | |
3db05fea | 157 | return nf_hook_slow(pf, hook, skb, indev, outdev, okfn, thresh); |
16a6677f PM |
158 | } |
159 | ||
3db05fea | 160 | static inline int nf_hook(int pf, unsigned int hook, struct sk_buff *skb, |
16a6677f PM |
161 | struct net_device *indev, struct net_device *outdev, |
162 | int (*okfn)(struct sk_buff *)) | |
163 | { | |
3db05fea | 164 | return nf_hook_thresh(pf, hook, skb, indev, outdev, okfn, INT_MIN, 1); |
16a6677f | 165 | } |
1da177e4 LT |
166 | |
167 | /* Activate hook; either okfn or kfree_skb called, unless a hook | |
168 | returns NF_STOLEN (in which case, it's up to the hook to deal with | |
169 | the consequences). | |
170 | ||
171 | Returns -ERRNO if packet dropped. Zero means queued, stolen or | |
172 | accepted. | |
173 | */ | |
174 | ||
175 | /* RR: | |
176 | > I don't want nf_hook to return anything because people might forget | |
177 | > about async and trust the return value to mean "packet was ok". | |
178 | ||
179 | AK: | |
180 | Just document it clearly, then you can expect some sense from kernel | |
181 | coders :) | |
182 | */ | |
183 | ||
184 | /* This is gross, but inline doesn't cut it for avoiding the function | |
185 | call in fast path: gcc doesn't inline (needs value tracking?). --RR */ | |
16a6677f PM |
186 | |
187 | /* HX: It's slightly less gross now. */ | |
188 | ||
1da177e4 LT |
189 | #define NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, thresh) \ |
190 | ({int __ret; \ | |
3db05fea | 191 | if ((__ret=nf_hook_thresh(pf, hook, (skb), indev, outdev, okfn, thresh, 1)) == 1)\ |
48d5cad8 PM |
192 | __ret = (okfn)(skb); \ |
193 | __ret;}) | |
194 | ||
195 | #define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond) \ | |
196 | ({int __ret; \ | |
3db05fea | 197 | if ((__ret=nf_hook_thresh(pf, hook, (skb), indev, outdev, okfn, INT_MIN, cond)) == 1)\ |
1da177e4 LT |
198 | __ret = (okfn)(skb); \ |
199 | __ret;}) | |
1da177e4 | 200 | |
16a6677f PM |
201 | #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) \ |
202 | NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, INT_MIN) | |
1da177e4 LT |
203 | |
204 | /* Call setsockopt() */ | |
205 | int nf_setsockopt(struct sock *sk, int pf, int optval, char __user *opt, | |
206 | int len); | |
207 | int nf_getsockopt(struct sock *sk, int pf, int optval, char __user *opt, | |
208 | int *len); | |
209 | ||
3fdadf7d DM |
210 | int compat_nf_setsockopt(struct sock *sk, int pf, int optval, |
211 | char __user *opt, int len); | |
212 | int compat_nf_getsockopt(struct sock *sk, int pf, int optval, | |
213 | char __user *opt, int *len); | |
214 | ||
089af26c HW |
215 | /* Call this before modifying an existing packet: ensures it is |
216 | modifiable and linear to the point you care about (writable_len). | |
217 | Returns true or false. */ | |
37d41879 | 218 | extern int skb_make_writable(struct sk_buff *skb, unsigned int writable_len); |
089af26c | 219 | |
1841a4c7 | 220 | struct flowi; |
02f014d8 | 221 | struct nf_queue_entry; |
c01cd429 | 222 | |
bce8032e PM |
223 | struct nf_afinfo { |
224 | unsigned short family; | |
b51655b9 | 225 | __sum16 (*checksum)(struct sk_buff *skb, unsigned int hook, |
422c346f | 226 | unsigned int dataoff, u_int8_t protocol); |
1841a4c7 | 227 | int (*route)(struct dst_entry **dst, struct flowi *fl); |
bce8032e | 228 | void (*saveroute)(const struct sk_buff *skb, |
02f014d8 | 229 | struct nf_queue_entry *entry); |
3db05fea | 230 | int (*reroute)(struct sk_buff *skb, |
02f014d8 | 231 | const struct nf_queue_entry *entry); |
bce8032e | 232 | int route_key_size; |
2cc7d573 HW |
233 | }; |
234 | ||
1e796fda PM |
235 | extern const struct nf_afinfo *nf_afinfo[NPROTO]; |
236 | static inline const struct nf_afinfo *nf_get_afinfo(unsigned short family) | |
bce8032e PM |
237 | { |
238 | return rcu_dereference(nf_afinfo[family]); | |
239 | } | |
2cc7d573 | 240 | |
b51655b9 | 241 | static inline __sum16 |
422c346f PM |
242 | nf_checksum(struct sk_buff *skb, unsigned int hook, unsigned int dataoff, |
243 | u_int8_t protocol, unsigned short family) | |
244 | { | |
1e796fda | 245 | const struct nf_afinfo *afinfo; |
b51655b9 | 246 | __sum16 csum = 0; |
422c346f PM |
247 | |
248 | rcu_read_lock(); | |
249 | afinfo = nf_get_afinfo(family); | |
250 | if (afinfo) | |
251 | csum = afinfo->checksum(skb, hook, dataoff, protocol); | |
252 | rcu_read_unlock(); | |
253 | return csum; | |
254 | } | |
255 | ||
1e796fda PM |
256 | extern int nf_register_afinfo(const struct nf_afinfo *afinfo); |
257 | extern void nf_unregister_afinfo(const struct nf_afinfo *afinfo); | |
bce8032e | 258 | |
eb9c7ebe PM |
259 | #include <net/flow.h> |
260 | extern void (*ip_nat_decode_session)(struct sk_buff *, struct flowi *); | |
261 | ||
262 | static inline void | |
263 | nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, int family) | |
264 | { | |
051578cc | 265 | #ifdef CONFIG_NF_NAT_NEEDED |
eb9c7ebe PM |
266 | void (*decodefn)(struct sk_buff *, struct flowi *); |
267 | ||
051578cc PM |
268 | if (family == AF_INET) { |
269 | rcu_read_lock(); | |
270 | decodefn = rcu_dereference(ip_nat_decode_session); | |
271 | if (decodefn) | |
272 | decodefn(skb, fl); | |
273 | rcu_read_unlock(); | |
274 | } | |
eb9c7ebe PM |
275 | #endif |
276 | } | |
277 | ||
608c8e4f HW |
278 | #ifdef CONFIG_PROC_FS |
279 | #include <linux/proc_fs.h> | |
280 | extern struct proc_dir_entry *proc_net_netfilter; | |
281 | #endif | |
282 | ||
1da177e4 LT |
283 | #else /* !CONFIG_NETFILTER */ |
284 | #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) (okfn)(skb) | |
48d5cad8 | 285 | #define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond) (okfn)(skb) |
f53b61d8 | 286 | static inline int nf_hook_thresh(int pf, unsigned int hook, |
3db05fea | 287 | struct sk_buff *skb, |
f53b61d8 DM |
288 | struct net_device *indev, |
289 | struct net_device *outdev, | |
48d5cad8 PM |
290 | int (*okfn)(struct sk_buff *), int thresh, |
291 | int cond) | |
f53b61d8 | 292 | { |
3db05fea | 293 | return okfn(skb); |
f53b61d8 | 294 | } |
3db05fea | 295 | static inline int nf_hook(int pf, unsigned int hook, struct sk_buff *skb, |
f53b61d8 DM |
296 | struct net_device *indev, struct net_device *outdev, |
297 | int (*okfn)(struct sk_buff *)) | |
298 | { | |
9c92d348 | 299 | return 1; |
f53b61d8 | 300 | } |
f53b61d8 | 301 | struct flowi; |
eb9c7ebe PM |
302 | static inline void |
303 | nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, int family) {} | |
1da177e4 LT |
304 | #endif /*CONFIG_NETFILTER*/ |
305 | ||
5f79e0f9 YK |
306 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) |
307 | extern void (*ip_ct_attach)(struct sk_buff *, struct sk_buff *); | |
308 | extern void nf_ct_attach(struct sk_buff *, struct sk_buff *); | |
de6e05c4 | 309 | extern void (*nf_ct_destroy)(struct nf_conntrack *); |
5f79e0f9 YK |
310 | #else |
311 | static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {} | |
312 | #endif | |
313 | ||
1da177e4 LT |
314 | #endif /*__KERNEL__*/ |
315 | #endif /*__LINUX_NETFILTER_H*/ |