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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 | ||
32 | #define NF_QUEUE_NR(x) ((x << NF_VERDICT_QBITS) & NF_VERDICT_QMASK || NF_QUEUE) | |
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__ | |
43 | #include <linux/config.h> | |
44 | #ifdef CONFIG_NETFILTER | |
45 | ||
46 | extern void netfilter_init(void); | |
47 | ||
48 | /* Largest hook number + 1 */ | |
49 | #define NF_MAX_HOOKS 8 | |
50 | ||
51 | struct sk_buff; | |
52 | struct net_device; | |
53 | ||
54 | typedef unsigned int nf_hookfn(unsigned int hooknum, | |
55 | struct sk_buff **skb, | |
56 | const struct net_device *in, | |
57 | const struct net_device *out, | |
58 | int (*okfn)(struct sk_buff *)); | |
59 | ||
60 | struct nf_hook_ops | |
61 | { | |
62 | struct list_head list; | |
63 | ||
64 | /* User fills in from here down. */ | |
65 | nf_hookfn *hook; | |
66 | struct module *owner; | |
67 | int pf; | |
68 | int hooknum; | |
69 | /* Hooks are ordered in ascending priority. */ | |
70 | int priority; | |
71 | }; | |
72 | ||
73 | struct nf_sockopt_ops | |
74 | { | |
75 | struct list_head list; | |
76 | ||
77 | int pf; | |
78 | ||
79 | /* Non-inclusive ranges: use 0/0/NULL to never get called. */ | |
80 | int set_optmin; | |
81 | int set_optmax; | |
82 | int (*set)(struct sock *sk, int optval, void __user *user, unsigned int len); | |
83 | ||
84 | int get_optmin; | |
85 | int get_optmax; | |
86 | int (*get)(struct sock *sk, int optval, void __user *user, int *len); | |
87 | ||
88 | /* Number of users inside set() or get(). */ | |
89 | unsigned int use; | |
90 | struct task_struct *cleanup_task; | |
91 | }; | |
92 | ||
93 | /* Each queued (to userspace) skbuff has one of these. */ | |
94 | struct nf_info | |
95 | { | |
96 | /* The ops struct which sent us to userspace. */ | |
97 | struct nf_hook_ops *elem; | |
98 | ||
99 | /* If we're sent to userspace, this keeps housekeeping info */ | |
100 | int pf; | |
101 | unsigned int hook; | |
102 | struct net_device *indev, *outdev; | |
103 | int (*okfn)(struct sk_buff *); | |
104 | }; | |
105 | ||
106 | /* Function to register/unregister hook points. */ | |
107 | int nf_register_hook(struct nf_hook_ops *reg); | |
108 | void nf_unregister_hook(struct nf_hook_ops *reg); | |
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 | ||
115 | extern struct list_head nf_hooks[NPROTO][NF_MAX_HOOKS]; | |
116 | ||
117 | typedef void nf_logfn(unsigned int hooknum, | |
118 | const struct sk_buff *skb, | |
119 | const struct net_device *in, | |
120 | const struct net_device *out, | |
121 | const char *prefix); | |
122 | ||
123 | /* Function to register/unregister log function. */ | |
124 | int nf_log_register(int pf, nf_logfn *logfn); | |
125 | void nf_log_unregister(int pf, nf_logfn *logfn); | |
126 | ||
127 | /* Calls the registered backend logging function */ | |
128 | void nf_log_packet(int pf, | |
129 | unsigned int hooknum, | |
130 | const struct sk_buff *skb, | |
131 | const struct net_device *in, | |
132 | const struct net_device *out, | |
133 | const char *fmt, ...); | |
134 | ||
135 | /* Activate hook; either okfn or kfree_skb called, unless a hook | |
136 | returns NF_STOLEN (in which case, it's up to the hook to deal with | |
137 | the consequences). | |
138 | ||
139 | Returns -ERRNO if packet dropped. Zero means queued, stolen or | |
140 | accepted. | |
141 | */ | |
142 | ||
143 | /* RR: | |
144 | > I don't want nf_hook to return anything because people might forget | |
145 | > about async and trust the return value to mean "packet was ok". | |
146 | ||
147 | AK: | |
148 | Just document it clearly, then you can expect some sense from kernel | |
149 | coders :) | |
150 | */ | |
151 | ||
152 | /* This is gross, but inline doesn't cut it for avoiding the function | |
153 | call in fast path: gcc doesn't inline (needs value tracking?). --RR */ | |
154 | #ifdef CONFIG_NETFILTER_DEBUG | |
155 | #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) \ | |
156 | ({int __ret; \ | |
157 | if ((__ret=nf_hook_slow(pf, hook, &(skb), indev, outdev, okfn, INT_MIN)) == 1) \ | |
158 | __ret = (okfn)(skb); \ | |
159 | __ret;}) | |
160 | #define NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, thresh) \ | |
161 | ({int __ret; \ | |
162 | if ((__ret=nf_hook_slow(pf, hook, &(skb), indev, outdev, okfn, thresh)) == 1) \ | |
163 | __ret = (okfn)(skb); \ | |
164 | __ret;}) | |
165 | #else | |
166 | #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) \ | |
167 | ({int __ret; \ | |
168 | if (list_empty(&nf_hooks[pf][hook]) || \ | |
169 | (__ret=nf_hook_slow(pf, hook, &(skb), indev, outdev, okfn, INT_MIN)) == 1) \ | |
170 | __ret = (okfn)(skb); \ | |
171 | __ret;}) | |
172 | #define NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, thresh) \ | |
173 | ({int __ret; \ | |
174 | if (list_empty(&nf_hooks[pf][hook]) || \ | |
175 | (__ret=nf_hook_slow(pf, hook, &(skb), indev, outdev, okfn, thresh)) == 1) \ | |
176 | __ret = (okfn)(skb); \ | |
177 | __ret;}) | |
178 | #endif | |
179 | ||
180 | int nf_hook_slow(int pf, unsigned int hook, struct sk_buff **pskb, | |
181 | struct net_device *indev, struct net_device *outdev, | |
182 | int (*okfn)(struct sk_buff *), int thresh); | |
183 | ||
184 | /* Call setsockopt() */ | |
185 | int nf_setsockopt(struct sock *sk, int pf, int optval, char __user *opt, | |
186 | int len); | |
187 | int nf_getsockopt(struct sock *sk, int pf, int optval, char __user *opt, | |
188 | int *len); | |
189 | ||
190 | /* Packet queuing */ | |
191 | typedef int (*nf_queue_outfn_t)(struct sk_buff *skb, | |
0ab43f84 HW |
192 | struct nf_info *info, |
193 | unsigned int queuenum, void *data); | |
1da177e4 LT |
194 | extern int nf_register_queue_handler(int pf, |
195 | nf_queue_outfn_t outfn, void *data); | |
196 | extern int nf_unregister_queue_handler(int pf); | |
0ab43f84 | 197 | extern void nf_unregister_queue_handlers(nf_queue_outfn_t outfn); |
1da177e4 LT |
198 | extern void nf_reinject(struct sk_buff *skb, |
199 | struct nf_info *info, | |
200 | unsigned int verdict); | |
201 | ||
202 | extern void (*ip_ct_attach)(struct sk_buff *, struct sk_buff *); | |
203 | extern void nf_ct_attach(struct sk_buff *, struct sk_buff *); | |
204 | ||
205 | /* FIXME: Before cache is ever used, this must be implemented for real. */ | |
206 | extern void nf_invalidate_cache(int pf); | |
207 | ||
089af26c HW |
208 | /* Call this before modifying an existing packet: ensures it is |
209 | modifiable and linear to the point you care about (writable_len). | |
210 | Returns true or false. */ | |
211 | extern int skb_make_writable(struct sk_buff **pskb, unsigned int writable_len); | |
212 | ||
2cc7d573 HW |
213 | struct nf_queue_rerouter { |
214 | void (*save)(const struct sk_buff *skb, struct nf_info *info); | |
215 | int (*reroute)(struct sk_buff **skb, const struct nf_info *info); | |
216 | int rer_size; | |
217 | }; | |
218 | ||
219 | #define nf_info_reroute(x) ((void *)x + sizeof(struct nf_info)) | |
220 | ||
221 | extern int nf_register_queue_rerouter(int pf, struct nf_queue_rerouter *rer); | |
222 | extern int nf_unregister_queue_rerouter(int pf); | |
223 | ||
1da177e4 LT |
224 | #else /* !CONFIG_NETFILTER */ |
225 | #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) (okfn)(skb) | |
226 | static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {} | |
227 | #endif /*CONFIG_NETFILTER*/ | |
228 | ||
229 | #endif /*__KERNEL__*/ | |
230 | #endif /*__LINUX_NETFILTER_H*/ |