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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> | |
10 | #include <linux/wait.h> | |
11 | #include <linux/list.h> | |
12 | #endif | |
13 | #include <linux/compiler.h> | |
14 | ||
15 | /* Responses from hook functions. */ | |
16 | #define NF_DROP 0 | |
17 | #define NF_ACCEPT 1 | |
18 | #define NF_STOLEN 2 | |
19 | #define NF_QUEUE 3 | |
20 | #define NF_REPEAT 4 | |
21 | #define NF_STOP 5 | |
22 | #define NF_MAX_VERDICT NF_STOP | |
23 | ||
0ab43f84 HW |
24 | /* we overload the higher bits for encoding auxiliary data such as the queue |
25 | * number. Not nice, but better than additional function arguments. */ | |
26 | #define NF_VERDICT_MASK 0x0000ffff | |
27 | #define NF_VERDICT_BITS 16 | |
28 | ||
29 | #define NF_VERDICT_QMASK 0xffff0000 | |
30 | #define NF_VERDICT_QBITS 16 | |
31 | ||
b766b305 | 32 | #define NF_QUEUE_NR(x) (((x << NF_VERDICT_QBITS) & NF_VERDICT_QMASK) | NF_QUEUE) |
0ab43f84 | 33 | |
6869c4d8 HW |
34 | /* only for userspace compatibility */ |
35 | #ifndef __KERNEL__ | |
1da177e4 LT |
36 | /* Generic cache responses from hook functions. |
37 | <= 0x2000 is used for protocol-flags. */ | |
38 | #define NFC_UNKNOWN 0x4000 | |
39 | #define NFC_ALTERED 0x8000 | |
6869c4d8 | 40 | #endif |
1da177e4 LT |
41 | |
42 | #ifdef __KERNEL__ | |
1da177e4 LT |
43 | #ifdef CONFIG_NETFILTER |
44 | ||
45 | extern void netfilter_init(void); | |
46 | ||
47 | /* Largest hook number + 1 */ | |
48 | #define NF_MAX_HOOKS 8 | |
49 | ||
50 | struct sk_buff; | |
51 | struct net_device; | |
52 | ||
53 | typedef unsigned int nf_hookfn(unsigned int hooknum, | |
54 | struct sk_buff **skb, | |
55 | const struct net_device *in, | |
56 | const struct net_device *out, | |
57 | int (*okfn)(struct sk_buff *)); | |
58 | ||
59 | struct nf_hook_ops | |
60 | { | |
61 | struct list_head list; | |
62 | ||
63 | /* User fills in from here down. */ | |
64 | nf_hookfn *hook; | |
65 | struct module *owner; | |
66 | int pf; | |
67 | int hooknum; | |
68 | /* Hooks are ordered in ascending priority. */ | |
69 | int priority; | |
70 | }; | |
71 | ||
72 | struct nf_sockopt_ops | |
73 | { | |
74 | struct list_head list; | |
75 | ||
76 | int pf; | |
77 | ||
78 | /* Non-inclusive ranges: use 0/0/NULL to never get called. */ | |
79 | int set_optmin; | |
80 | int set_optmax; | |
81 | int (*set)(struct sock *sk, int optval, void __user *user, unsigned int len); | |
3fdadf7d DM |
82 | int (*compat_set)(struct sock *sk, int optval, |
83 | void __user *user, unsigned int len); | |
1da177e4 LT |
84 | |
85 | int get_optmin; | |
86 | int get_optmax; | |
87 | int (*get)(struct sock *sk, int optval, void __user *user, int *len); | |
3fdadf7d DM |
88 | int (*compat_get)(struct sock *sk, int optval, |
89 | void __user *user, int *len); | |
1da177e4 LT |
90 | |
91 | /* Number of users inside set() or get(). */ | |
92 | unsigned int use; | |
93 | struct task_struct *cleanup_task; | |
94 | }; | |
95 | ||
96 | /* Each queued (to userspace) skbuff has one of these. */ | |
97 | struct nf_info | |
98 | { | |
99 | /* The ops struct which sent us to userspace. */ | |
100 | struct nf_hook_ops *elem; | |
101 | ||
102 | /* If we're sent to userspace, this keeps housekeeping info */ | |
103 | int pf; | |
104 | unsigned int hook; | |
105 | struct net_device *indev, *outdev; | |
106 | int (*okfn)(struct sk_buff *); | |
107 | }; | |
108 | ||
109 | /* Function to register/unregister hook points. */ | |
110 | int nf_register_hook(struct nf_hook_ops *reg); | |
111 | void nf_unregister_hook(struct nf_hook_ops *reg); | |
972d1cb1 PM |
112 | int nf_register_hooks(struct nf_hook_ops *reg, unsigned int n); |
113 | void nf_unregister_hooks(struct nf_hook_ops *reg, unsigned int n); | |
1da177e4 LT |
114 | |
115 | /* Functions to register get/setsockopt ranges (non-inclusive). You | |
116 | need to check permissions yourself! */ | |
117 | int nf_register_sockopt(struct nf_sockopt_ops *reg); | |
118 | void nf_unregister_sockopt(struct nf_sockopt_ops *reg); | |
119 | ||
d62f9ed4 PM |
120 | #ifdef CONFIG_SYSCTL |
121 | /* Sysctl registration */ | |
122 | struct ctl_table_header *nf_register_sysctl_table(struct ctl_table *path, | |
123 | struct ctl_table *table); | |
124 | void nf_unregister_sysctl_table(struct ctl_table_header *header, | |
125 | struct ctl_table *table); | |
126 | extern struct ctl_table nf_net_netfilter_sysctl_path[]; | |
127 | extern struct ctl_table nf_net_ipv4_netfilter_sysctl_path[]; | |
128 | #endif /* CONFIG_SYSCTL */ | |
129 | ||
1da177e4 LT |
130 | extern struct list_head nf_hooks[NPROTO][NF_MAX_HOOKS]; |
131 | ||
608c8e4f HW |
132 | /* those NF_LOG_* defines and struct nf_loginfo are legacy definitios that will |
133 | * disappear once iptables is replaced with pkttables. Please DO NOT use them | |
134 | * for any new code! */ | |
135 | #define NF_LOG_TCPSEQ 0x01 /* Log TCP sequence numbers */ | |
136 | #define NF_LOG_TCPOPT 0x02 /* Log TCP options */ | |
137 | #define NF_LOG_IPOPT 0x04 /* Log IP options */ | |
138 | #define NF_LOG_UID 0x08 /* Log UID owning local socket */ | |
139 | #define NF_LOG_MASK 0x0f | |
140 | ||
141 | #define NF_LOG_TYPE_LOG 0x01 | |
142 | #define NF_LOG_TYPE_ULOG 0x02 | |
143 | ||
144 | struct nf_loginfo { | |
145 | u_int8_t type; | |
146 | union { | |
147 | struct { | |
148 | u_int32_t copy_len; | |
149 | u_int16_t group; | |
150 | u_int16_t qthreshold; | |
151 | } ulog; | |
152 | struct { | |
153 | u_int8_t level; | |
154 | u_int8_t logflags; | |
155 | } log; | |
156 | } u; | |
157 | }; | |
158 | ||
159 | typedef void nf_logfn(unsigned int pf, | |
160 | unsigned int hooknum, | |
1da177e4 LT |
161 | const struct sk_buff *skb, |
162 | const struct net_device *in, | |
163 | const struct net_device *out, | |
608c8e4f | 164 | const struct nf_loginfo *li, |
1da177e4 LT |
165 | const char *prefix); |
166 | ||
608c8e4f HW |
167 | struct nf_logger { |
168 | struct module *me; | |
169 | nf_logfn *logfn; | |
170 | char *name; | |
171 | }; | |
172 | ||
1da177e4 | 173 | /* Function to register/unregister log function. */ |
608c8e4f | 174 | int nf_log_register(int pf, struct nf_logger *logger); |
e92ad99c | 175 | void nf_log_unregister(struct nf_logger *logger); |
9dc6aa5f | 176 | void nf_log_unregister_pf(int pf); |
1da177e4 LT |
177 | |
178 | /* Calls the registered backend logging function */ | |
179 | void nf_log_packet(int pf, | |
180 | unsigned int hooknum, | |
181 | const struct sk_buff *skb, | |
182 | const struct net_device *in, | |
183 | const struct net_device *out, | |
608c8e4f | 184 | struct nf_loginfo *li, |
1da177e4 | 185 | const char *fmt, ...); |
16a6677f PM |
186 | |
187 | int nf_hook_slow(int pf, unsigned int hook, struct sk_buff **pskb, | |
188 | struct net_device *indev, struct net_device *outdev, | |
189 | int (*okfn)(struct sk_buff *), int thresh); | |
190 | ||
191 | /** | |
192 | * nf_hook_thresh - call a netfilter hook | |
193 | * | |
194 | * Returns 1 if the hook has allowed the packet to pass. The function | |
195 | * okfn must be invoked by the caller in this case. Any other return | |
196 | * value indicates the packet has been consumed by the hook. | |
197 | */ | |
198 | static inline int nf_hook_thresh(int pf, unsigned int hook, | |
199 | struct sk_buff **pskb, | |
200 | struct net_device *indev, | |
201 | struct net_device *outdev, | |
48d5cad8 PM |
202 | int (*okfn)(struct sk_buff *), int thresh, |
203 | int cond) | |
16a6677f | 204 | { |
48d5cad8 PM |
205 | if (!cond) |
206 | return 1; | |
16a6677f PM |
207 | #ifndef CONFIG_NETFILTER_DEBUG |
208 | if (list_empty(&nf_hooks[pf][hook])) | |
209 | return 1; | |
210 | #endif | |
211 | return nf_hook_slow(pf, hook, pskb, indev, outdev, okfn, thresh); | |
212 | } | |
213 | ||
214 | static inline int nf_hook(int pf, unsigned int hook, struct sk_buff **pskb, | |
215 | struct net_device *indev, struct net_device *outdev, | |
216 | int (*okfn)(struct sk_buff *)) | |
217 | { | |
48d5cad8 | 218 | return nf_hook_thresh(pf, hook, pskb, indev, outdev, okfn, INT_MIN, 1); |
16a6677f | 219 | } |
1da177e4 LT |
220 | |
221 | /* Activate hook; either okfn or kfree_skb called, unless a hook | |
222 | returns NF_STOLEN (in which case, it's up to the hook to deal with | |
223 | the consequences). | |
224 | ||
225 | Returns -ERRNO if packet dropped. Zero means queued, stolen or | |
226 | accepted. | |
227 | */ | |
228 | ||
229 | /* RR: | |
230 | > I don't want nf_hook to return anything because people might forget | |
231 | > about async and trust the return value to mean "packet was ok". | |
232 | ||
233 | AK: | |
234 | Just document it clearly, then you can expect some sense from kernel | |
235 | coders :) | |
236 | */ | |
237 | ||
238 | /* This is gross, but inline doesn't cut it for avoiding the function | |
239 | call in fast path: gcc doesn't inline (needs value tracking?). --RR */ | |
16a6677f PM |
240 | |
241 | /* HX: It's slightly less gross now. */ | |
242 | ||
1da177e4 LT |
243 | #define NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, thresh) \ |
244 | ({int __ret; \ | |
48d5cad8 PM |
245 | if ((__ret=nf_hook_thresh(pf, hook, &(skb), indev, outdev, okfn, thresh, 1)) == 1)\ |
246 | __ret = (okfn)(skb); \ | |
247 | __ret;}) | |
248 | ||
249 | #define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond) \ | |
250 | ({int __ret; \ | |
251 | if ((__ret=nf_hook_thresh(pf, hook, &(skb), indev, outdev, okfn, INT_MIN, cond)) == 1)\ | |
1da177e4 LT |
252 | __ret = (okfn)(skb); \ |
253 | __ret;}) | |
1da177e4 | 254 | |
16a6677f PM |
255 | #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) \ |
256 | NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, INT_MIN) | |
1da177e4 LT |
257 | |
258 | /* Call setsockopt() */ | |
259 | int nf_setsockopt(struct sock *sk, int pf, int optval, char __user *opt, | |
260 | int len); | |
261 | int nf_getsockopt(struct sock *sk, int pf, int optval, char __user *opt, | |
262 | int *len); | |
263 | ||
3fdadf7d DM |
264 | int compat_nf_setsockopt(struct sock *sk, int pf, int optval, |
265 | char __user *opt, int len); | |
266 | int compat_nf_getsockopt(struct sock *sk, int pf, int optval, | |
267 | char __user *opt, int *len); | |
268 | ||
1da177e4 | 269 | /* Packet queuing */ |
bbd86b9f HW |
270 | struct nf_queue_handler { |
271 | int (*outfn)(struct sk_buff *skb, struct nf_info *info, | |
272 | unsigned int queuenum, void *data); | |
273 | void *data; | |
274 | char *name; | |
275 | }; | |
1da177e4 | 276 | extern int nf_register_queue_handler(int pf, |
bbd86b9f | 277 | struct nf_queue_handler *qh); |
1da177e4 | 278 | extern int nf_unregister_queue_handler(int pf); |
bbd86b9f | 279 | extern void nf_unregister_queue_handlers(struct nf_queue_handler *qh); |
1da177e4 LT |
280 | extern void nf_reinject(struct sk_buff *skb, |
281 | struct nf_info *info, | |
282 | unsigned int verdict); | |
283 | ||
1da177e4 LT |
284 | /* FIXME: Before cache is ever used, this must be implemented for real. */ |
285 | extern void nf_invalidate_cache(int pf); | |
286 | ||
089af26c HW |
287 | /* Call this before modifying an existing packet: ensures it is |
288 | modifiable and linear to the point you care about (writable_len). | |
289 | Returns true or false. */ | |
290 | extern int skb_make_writable(struct sk_buff **pskb, unsigned int writable_len); | |
291 | ||
43bc0ca7 AV |
292 | static inline void nf_csum_replace4(__sum16 *sum, __be32 from, __be32 to) |
293 | { | |
294 | __be32 diff[] = { ~from, to }; | |
295 | ||
296 | *sum = csum_fold(csum_partial((char *)diff, sizeof(diff), ~csum_unfold(*sum))); | |
297 | } | |
298 | ||
299 | static inline void nf_csum_replace2(__sum16 *sum, __be16 from, __be16 to) | |
300 | { | |
301 | nf_csum_replace4(sum, (__force __be32)from, (__force __be32)to); | |
302 | } | |
303 | ||
304 | extern void nf_proto_csum_replace4(__sum16 *sum, struct sk_buff *skb, | |
305 | __be32 from, __be32 to, int pseudohdr); | |
306 | ||
307 | static inline void nf_proto_csum_replace2(__sum16 *sum, struct sk_buff *skb, | |
308 | __be16 from, __be16 to, int pseudohdr) | |
309 | { | |
310 | nf_proto_csum_replace4(sum, skb, (__force __be32)from, | |
311 | (__force __be32)to, pseudohdr); | |
312 | } | |
4cf411de | 313 | |
bce8032e PM |
314 | struct nf_afinfo { |
315 | unsigned short family; | |
b51655b9 | 316 | __sum16 (*checksum)(struct sk_buff *skb, unsigned int hook, |
422c346f | 317 | unsigned int dataoff, u_int8_t protocol); |
bce8032e PM |
318 | void (*saveroute)(const struct sk_buff *skb, |
319 | struct nf_info *info); | |
320 | int (*reroute)(struct sk_buff **skb, | |
321 | const struct nf_info *info); | |
322 | int route_key_size; | |
2cc7d573 HW |
323 | }; |
324 | ||
bce8032e PM |
325 | extern struct nf_afinfo *nf_afinfo[]; |
326 | static inline struct nf_afinfo *nf_get_afinfo(unsigned short family) | |
327 | { | |
328 | return rcu_dereference(nf_afinfo[family]); | |
329 | } | |
2cc7d573 | 330 | |
b51655b9 | 331 | static inline __sum16 |
422c346f PM |
332 | nf_checksum(struct sk_buff *skb, unsigned int hook, unsigned int dataoff, |
333 | u_int8_t protocol, unsigned short family) | |
334 | { | |
335 | struct nf_afinfo *afinfo; | |
b51655b9 | 336 | __sum16 csum = 0; |
422c346f PM |
337 | |
338 | rcu_read_lock(); | |
339 | afinfo = nf_get_afinfo(family); | |
340 | if (afinfo) | |
341 | csum = afinfo->checksum(skb, hook, dataoff, protocol); | |
342 | rcu_read_unlock(); | |
343 | return csum; | |
344 | } | |
345 | ||
bce8032e PM |
346 | extern int nf_register_afinfo(struct nf_afinfo *afinfo); |
347 | extern void nf_unregister_afinfo(struct nf_afinfo *afinfo); | |
348 | ||
349 | #define nf_info_reroute(x) ((void *)x + sizeof(struct nf_info)) | |
2cc7d573 | 350 | |
eb9c7ebe PM |
351 | #include <net/flow.h> |
352 | extern void (*ip_nat_decode_session)(struct sk_buff *, struct flowi *); | |
353 | ||
354 | static inline void | |
355 | nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, int family) | |
356 | { | |
5b1158e9 | 357 | #if defined(CONFIG_IP_NF_NAT_NEEDED) || defined(CONFIG_NF_NAT_NEEDED) |
eb9c7ebe PM |
358 | void (*decodefn)(struct sk_buff *, struct flowi *); |
359 | ||
360 | if (family == AF_INET && (decodefn = ip_nat_decode_session) != NULL) | |
361 | decodefn(skb, fl); | |
362 | #endif | |
363 | } | |
364 | ||
608c8e4f HW |
365 | #ifdef CONFIG_PROC_FS |
366 | #include <linux/proc_fs.h> | |
367 | extern struct proc_dir_entry *proc_net_netfilter; | |
368 | #endif | |
369 | ||
1da177e4 LT |
370 | #else /* !CONFIG_NETFILTER */ |
371 | #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) (okfn)(skb) | |
48d5cad8 | 372 | #define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond) (okfn)(skb) |
f53b61d8 DM |
373 | static inline int nf_hook_thresh(int pf, unsigned int hook, |
374 | struct sk_buff **pskb, | |
375 | struct net_device *indev, | |
376 | struct net_device *outdev, | |
48d5cad8 PM |
377 | int (*okfn)(struct sk_buff *), int thresh, |
378 | int cond) | |
f53b61d8 DM |
379 | { |
380 | return okfn(*pskb); | |
381 | } | |
382 | static inline int nf_hook(int pf, unsigned int hook, struct sk_buff **pskb, | |
383 | struct net_device *indev, struct net_device *outdev, | |
384 | int (*okfn)(struct sk_buff *)) | |
385 | { | |
9c92d348 | 386 | return 1; |
f53b61d8 | 387 | } |
f53b61d8 | 388 | struct flowi; |
eb9c7ebe PM |
389 | static inline void |
390 | nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, int family) {} | |
1da177e4 LT |
391 | #endif /*CONFIG_NETFILTER*/ |
392 | ||
5f79e0f9 YK |
393 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) |
394 | extern void (*ip_ct_attach)(struct sk_buff *, struct sk_buff *); | |
395 | extern void nf_ct_attach(struct sk_buff *, struct sk_buff *); | |
396 | #else | |
397 | static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {} | |
398 | #endif | |
399 | ||
1da177e4 LT |
400 | #endif /*__KERNEL__*/ |
401 | #endif /*__LINUX_NETFILTER_H*/ |