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> | |
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 | 41 | |
6e23ae2a PM |
42 | enum nf_inet_hooks { |
43 | NF_INET_PRE_ROUTING, | |
44 | NF_INET_LOCAL_IN, | |
45 | NF_INET_FORWARD, | |
46 | NF_INET_LOCAL_OUT, | |
47 | NF_INET_POST_ROUTING, | |
48 | NF_INET_NUMHOOKS | |
49 | }; | |
50 | ||
1da177e4 | 51 | #ifdef __KERNEL__ |
1da177e4 LT |
52 | #ifdef CONFIG_NETFILTER |
53 | ||
54 | extern void netfilter_init(void); | |
55 | ||
56 | /* Largest hook number + 1 */ | |
57 | #define NF_MAX_HOOKS 8 | |
58 | ||
59 | struct sk_buff; | |
60 | struct net_device; | |
61 | ||
62 | typedef unsigned int nf_hookfn(unsigned int hooknum, | |
3db05fea | 63 | struct sk_buff *skb, |
1da177e4 LT |
64 | const struct net_device *in, |
65 | const struct net_device *out, | |
66 | int (*okfn)(struct sk_buff *)); | |
67 | ||
68 | struct nf_hook_ops | |
69 | { | |
70 | struct list_head list; | |
71 | ||
72 | /* User fills in from here down. */ | |
73 | nf_hookfn *hook; | |
74 | struct module *owner; | |
75 | int pf; | |
76 | int hooknum; | |
77 | /* Hooks are ordered in ascending priority. */ | |
78 | int priority; | |
79 | }; | |
80 | ||
81 | struct nf_sockopt_ops | |
82 | { | |
83 | struct list_head list; | |
84 | ||
85 | int pf; | |
86 | ||
87 | /* Non-inclusive ranges: use 0/0/NULL to never get called. */ | |
88 | int set_optmin; | |
89 | int set_optmax; | |
90 | int (*set)(struct sock *sk, int optval, void __user *user, unsigned int len); | |
3fdadf7d DM |
91 | int (*compat_set)(struct sock *sk, int optval, |
92 | void __user *user, unsigned int len); | |
1da177e4 LT |
93 | |
94 | int get_optmin; | |
95 | int get_optmax; | |
96 | int (*get)(struct sock *sk, int optval, void __user *user, int *len); | |
3fdadf7d DM |
97 | int (*compat_get)(struct sock *sk, int optval, |
98 | void __user *user, int *len); | |
1da177e4 | 99 | |
16fcec35 NH |
100 | /* Use the module struct to lock set/get code in place */ |
101 | struct module *owner; | |
1da177e4 LT |
102 | }; |
103 | ||
1da177e4 LT |
104 | /* Function to register/unregister hook points. */ |
105 | int nf_register_hook(struct nf_hook_ops *reg); | |
106 | void nf_unregister_hook(struct nf_hook_ops *reg); | |
972d1cb1 PM |
107 | int nf_register_hooks(struct nf_hook_ops *reg, unsigned int n); |
108 | void nf_unregister_hooks(struct nf_hook_ops *reg, unsigned int n); | |
1da177e4 LT |
109 | |
110 | /* Functions to register get/setsockopt ranges (non-inclusive). You | |
111 | need to check permissions yourself! */ | |
112 | int nf_register_sockopt(struct nf_sockopt_ops *reg); | |
113 | void nf_unregister_sockopt(struct nf_sockopt_ops *reg); | |
114 | ||
d62f9ed4 PM |
115 | #ifdef CONFIG_SYSCTL |
116 | /* Sysctl registration */ | |
117 | struct ctl_table_header *nf_register_sysctl_table(struct ctl_table *path, | |
118 | struct ctl_table *table); | |
119 | void nf_unregister_sysctl_table(struct ctl_table_header *header, | |
120 | struct ctl_table *table); | |
121 | extern struct ctl_table nf_net_netfilter_sysctl_path[]; | |
122 | extern struct ctl_table nf_net_ipv4_netfilter_sysctl_path[]; | |
123 | #endif /* CONFIG_SYSCTL */ | |
124 | ||
1da177e4 LT |
125 | extern struct list_head nf_hooks[NPROTO][NF_MAX_HOOKS]; |
126 | ||
3db05fea | 127 | int nf_hook_slow(int pf, unsigned int hook, struct sk_buff *skb, |
16a6677f PM |
128 | struct net_device *indev, struct net_device *outdev, |
129 | int (*okfn)(struct sk_buff *), int thresh); | |
130 | ||
131 | /** | |
132 | * nf_hook_thresh - call a netfilter hook | |
133 | * | |
134 | * Returns 1 if the hook has allowed the packet to pass. The function | |
135 | * okfn must be invoked by the caller in this case. Any other return | |
136 | * value indicates the packet has been consumed by the hook. | |
137 | */ | |
138 | static inline int nf_hook_thresh(int pf, unsigned int hook, | |
3db05fea | 139 | struct sk_buff *skb, |
16a6677f PM |
140 | struct net_device *indev, |
141 | struct net_device *outdev, | |
48d5cad8 PM |
142 | int (*okfn)(struct sk_buff *), int thresh, |
143 | int cond) | |
16a6677f | 144 | { |
48d5cad8 PM |
145 | if (!cond) |
146 | return 1; | |
16a6677f PM |
147 | #ifndef CONFIG_NETFILTER_DEBUG |
148 | if (list_empty(&nf_hooks[pf][hook])) | |
149 | return 1; | |
150 | #endif | |
3db05fea | 151 | return nf_hook_slow(pf, hook, skb, indev, outdev, okfn, thresh); |
16a6677f PM |
152 | } |
153 | ||
3db05fea | 154 | static inline int nf_hook(int pf, unsigned int hook, struct sk_buff *skb, |
16a6677f PM |
155 | struct net_device *indev, struct net_device *outdev, |
156 | int (*okfn)(struct sk_buff *)) | |
157 | { | |
3db05fea | 158 | return nf_hook_thresh(pf, hook, skb, indev, outdev, okfn, INT_MIN, 1); |
16a6677f | 159 | } |
1da177e4 LT |
160 | |
161 | /* Activate hook; either okfn or kfree_skb called, unless a hook | |
162 | returns NF_STOLEN (in which case, it's up to the hook to deal with | |
163 | the consequences). | |
164 | ||
165 | Returns -ERRNO if packet dropped. Zero means queued, stolen or | |
166 | accepted. | |
167 | */ | |
168 | ||
169 | /* RR: | |
170 | > I don't want nf_hook to return anything because people might forget | |
171 | > about async and trust the return value to mean "packet was ok". | |
172 | ||
173 | AK: | |
174 | Just document it clearly, then you can expect some sense from kernel | |
175 | coders :) | |
176 | */ | |
177 | ||
178 | /* This is gross, but inline doesn't cut it for avoiding the function | |
179 | call in fast path: gcc doesn't inline (needs value tracking?). --RR */ | |
16a6677f PM |
180 | |
181 | /* HX: It's slightly less gross now. */ | |
182 | ||
1da177e4 LT |
183 | #define NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, thresh) \ |
184 | ({int __ret; \ | |
3db05fea | 185 | if ((__ret=nf_hook_thresh(pf, hook, (skb), indev, outdev, okfn, thresh, 1)) == 1)\ |
48d5cad8 PM |
186 | __ret = (okfn)(skb); \ |
187 | __ret;}) | |
188 | ||
189 | #define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond) \ | |
190 | ({int __ret; \ | |
3db05fea | 191 | if ((__ret=nf_hook_thresh(pf, hook, (skb), indev, outdev, okfn, INT_MIN, cond)) == 1)\ |
1da177e4 LT |
192 | __ret = (okfn)(skb); \ |
193 | __ret;}) | |
1da177e4 | 194 | |
16a6677f PM |
195 | #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) \ |
196 | NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, INT_MIN) | |
1da177e4 LT |
197 | |
198 | /* Call setsockopt() */ | |
199 | int nf_setsockopt(struct sock *sk, int pf, int optval, char __user *opt, | |
200 | int len); | |
201 | int nf_getsockopt(struct sock *sk, int pf, int optval, char __user *opt, | |
202 | int *len); | |
203 | ||
3fdadf7d DM |
204 | int compat_nf_setsockopt(struct sock *sk, int pf, int optval, |
205 | char __user *opt, int len); | |
206 | int compat_nf_getsockopt(struct sock *sk, int pf, int optval, | |
207 | char __user *opt, int *len); | |
208 | ||
089af26c HW |
209 | /* Call this before modifying an existing packet: ensures it is |
210 | modifiable and linear to the point you care about (writable_len). | |
211 | Returns true or false. */ | |
37d41879 | 212 | extern int skb_make_writable(struct sk_buff *skb, unsigned int writable_len); |
089af26c | 213 | |
1841a4c7 | 214 | struct flowi; |
02f014d8 | 215 | struct nf_queue_entry; |
c01cd429 | 216 | |
bce8032e PM |
217 | struct nf_afinfo { |
218 | unsigned short family; | |
b51655b9 | 219 | __sum16 (*checksum)(struct sk_buff *skb, unsigned int hook, |
422c346f | 220 | unsigned int dataoff, u_int8_t protocol); |
1841a4c7 | 221 | int (*route)(struct dst_entry **dst, struct flowi *fl); |
bce8032e | 222 | void (*saveroute)(const struct sk_buff *skb, |
02f014d8 | 223 | struct nf_queue_entry *entry); |
3db05fea | 224 | int (*reroute)(struct sk_buff *skb, |
02f014d8 | 225 | const struct nf_queue_entry *entry); |
bce8032e | 226 | int route_key_size; |
2cc7d573 HW |
227 | }; |
228 | ||
bce8032e PM |
229 | extern struct nf_afinfo *nf_afinfo[]; |
230 | static inline struct nf_afinfo *nf_get_afinfo(unsigned short family) | |
231 | { | |
232 | return rcu_dereference(nf_afinfo[family]); | |
233 | } | |
2cc7d573 | 234 | |
b51655b9 | 235 | static inline __sum16 |
422c346f PM |
236 | nf_checksum(struct sk_buff *skb, unsigned int hook, unsigned int dataoff, |
237 | u_int8_t protocol, unsigned short family) | |
238 | { | |
239 | struct nf_afinfo *afinfo; | |
b51655b9 | 240 | __sum16 csum = 0; |
422c346f PM |
241 | |
242 | rcu_read_lock(); | |
243 | afinfo = nf_get_afinfo(family); | |
244 | if (afinfo) | |
245 | csum = afinfo->checksum(skb, hook, dataoff, protocol); | |
246 | rcu_read_unlock(); | |
247 | return csum; | |
248 | } | |
249 | ||
bce8032e PM |
250 | extern int nf_register_afinfo(struct nf_afinfo *afinfo); |
251 | extern void nf_unregister_afinfo(struct nf_afinfo *afinfo); | |
252 | ||
eb9c7ebe PM |
253 | #include <net/flow.h> |
254 | extern void (*ip_nat_decode_session)(struct sk_buff *, struct flowi *); | |
255 | ||
256 | static inline void | |
257 | nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, int family) | |
258 | { | |
5b1158e9 | 259 | #if defined(CONFIG_IP_NF_NAT_NEEDED) || defined(CONFIG_NF_NAT_NEEDED) |
eb9c7ebe PM |
260 | void (*decodefn)(struct sk_buff *, struct flowi *); |
261 | ||
262 | if (family == AF_INET && (decodefn = ip_nat_decode_session) != NULL) | |
263 | decodefn(skb, fl); | |
264 | #endif | |
265 | } | |
266 | ||
608c8e4f HW |
267 | #ifdef CONFIG_PROC_FS |
268 | #include <linux/proc_fs.h> | |
269 | extern struct proc_dir_entry *proc_net_netfilter; | |
270 | #endif | |
271 | ||
1da177e4 LT |
272 | #else /* !CONFIG_NETFILTER */ |
273 | #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) (okfn)(skb) | |
48d5cad8 | 274 | #define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond) (okfn)(skb) |
f53b61d8 | 275 | static inline int nf_hook_thresh(int pf, unsigned int hook, |
3db05fea | 276 | struct sk_buff *skb, |
f53b61d8 DM |
277 | struct net_device *indev, |
278 | struct net_device *outdev, | |
48d5cad8 PM |
279 | int (*okfn)(struct sk_buff *), int thresh, |
280 | int cond) | |
f53b61d8 | 281 | { |
3db05fea | 282 | return okfn(skb); |
f53b61d8 | 283 | } |
3db05fea | 284 | static inline int nf_hook(int pf, unsigned int hook, struct sk_buff *skb, |
f53b61d8 DM |
285 | struct net_device *indev, struct net_device *outdev, |
286 | int (*okfn)(struct sk_buff *)) | |
287 | { | |
9c92d348 | 288 | return 1; |
f53b61d8 | 289 | } |
f53b61d8 | 290 | struct flowi; |
eb9c7ebe PM |
291 | static inline void |
292 | nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, int family) {} | |
1da177e4 LT |
293 | #endif /*CONFIG_NETFILTER*/ |
294 | ||
5f79e0f9 YK |
295 | #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) |
296 | extern void (*ip_ct_attach)(struct sk_buff *, struct sk_buff *); | |
297 | extern void nf_ct_attach(struct sk_buff *, struct sk_buff *); | |
de6e05c4 | 298 | extern void (*nf_ct_destroy)(struct nf_conntrack *); |
5f79e0f9 YK |
299 | #else |
300 | static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {} | |
301 | #endif | |
302 | ||
1da177e4 LT |
303 | #endif /*__KERNEL__*/ |
304 | #endif /*__LINUX_NETFILTER_H*/ |