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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 | ||
24 | /* Generic cache responses from hook functions. | |
25 | <= 0x2000 is used for protocol-flags. */ | |
26 | #define NFC_UNKNOWN 0x4000 | |
27 | #define NFC_ALTERED 0x8000 | |
28 | ||
29 | #ifdef __KERNEL__ | |
30 | #include <linux/config.h> | |
31 | #ifdef CONFIG_NETFILTER | |
32 | ||
33 | extern void netfilter_init(void); | |
34 | ||
35 | /* Largest hook number + 1 */ | |
36 | #define NF_MAX_HOOKS 8 | |
37 | ||
38 | struct sk_buff; | |
39 | struct net_device; | |
40 | ||
41 | typedef unsigned int nf_hookfn(unsigned int hooknum, | |
42 | struct sk_buff **skb, | |
43 | const struct net_device *in, | |
44 | const struct net_device *out, | |
45 | int (*okfn)(struct sk_buff *)); | |
46 | ||
47 | struct nf_hook_ops | |
48 | { | |
49 | struct list_head list; | |
50 | ||
51 | /* User fills in from here down. */ | |
52 | nf_hookfn *hook; | |
53 | struct module *owner; | |
54 | int pf; | |
55 | int hooknum; | |
56 | /* Hooks are ordered in ascending priority. */ | |
57 | int priority; | |
58 | }; | |
59 | ||
60 | struct nf_sockopt_ops | |
61 | { | |
62 | struct list_head list; | |
63 | ||
64 | int pf; | |
65 | ||
66 | /* Non-inclusive ranges: use 0/0/NULL to never get called. */ | |
67 | int set_optmin; | |
68 | int set_optmax; | |
69 | int (*set)(struct sock *sk, int optval, void __user *user, unsigned int len); | |
70 | ||
71 | int get_optmin; | |
72 | int get_optmax; | |
73 | int (*get)(struct sock *sk, int optval, void __user *user, int *len); | |
74 | ||
75 | /* Number of users inside set() or get(). */ | |
76 | unsigned int use; | |
77 | struct task_struct *cleanup_task; | |
78 | }; | |
79 | ||
80 | /* Each queued (to userspace) skbuff has one of these. */ | |
81 | struct nf_info | |
82 | { | |
83 | /* The ops struct which sent us to userspace. */ | |
84 | struct nf_hook_ops *elem; | |
85 | ||
86 | /* If we're sent to userspace, this keeps housekeeping info */ | |
87 | int pf; | |
88 | unsigned int hook; | |
89 | struct net_device *indev, *outdev; | |
90 | int (*okfn)(struct sk_buff *); | |
91 | }; | |
92 | ||
93 | /* Function to register/unregister hook points. */ | |
94 | int nf_register_hook(struct nf_hook_ops *reg); | |
95 | void nf_unregister_hook(struct nf_hook_ops *reg); | |
96 | ||
97 | /* Functions to register get/setsockopt ranges (non-inclusive). You | |
98 | need to check permissions yourself! */ | |
99 | int nf_register_sockopt(struct nf_sockopt_ops *reg); | |
100 | void nf_unregister_sockopt(struct nf_sockopt_ops *reg); | |
101 | ||
102 | extern struct list_head nf_hooks[NPROTO][NF_MAX_HOOKS]; | |
103 | ||
104 | typedef void nf_logfn(unsigned int hooknum, | |
105 | const struct sk_buff *skb, | |
106 | const struct net_device *in, | |
107 | const struct net_device *out, | |
108 | const char *prefix); | |
109 | ||
110 | /* Function to register/unregister log function. */ | |
111 | int nf_log_register(int pf, nf_logfn *logfn); | |
112 | void nf_log_unregister(int pf, nf_logfn *logfn); | |
113 | ||
114 | /* Calls the registered backend logging function */ | |
115 | void nf_log_packet(int pf, | |
116 | unsigned int hooknum, | |
117 | const struct sk_buff *skb, | |
118 | const struct net_device *in, | |
119 | const struct net_device *out, | |
120 | const char *fmt, ...); | |
121 | ||
122 | /* Activate hook; either okfn or kfree_skb called, unless a hook | |
123 | returns NF_STOLEN (in which case, it's up to the hook to deal with | |
124 | the consequences). | |
125 | ||
126 | Returns -ERRNO if packet dropped. Zero means queued, stolen or | |
127 | accepted. | |
128 | */ | |
129 | ||
130 | /* RR: | |
131 | > I don't want nf_hook to return anything because people might forget | |
132 | > about async and trust the return value to mean "packet was ok". | |
133 | ||
134 | AK: | |
135 | Just document it clearly, then you can expect some sense from kernel | |
136 | coders :) | |
137 | */ | |
138 | ||
139 | /* This is gross, but inline doesn't cut it for avoiding the function | |
140 | call in fast path: gcc doesn't inline (needs value tracking?). --RR */ | |
141 | #ifdef CONFIG_NETFILTER_DEBUG | |
142 | #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) \ | |
143 | ({int __ret; \ | |
144 | if ((__ret=nf_hook_slow(pf, hook, &(skb), indev, outdev, okfn, INT_MIN)) == 1) \ | |
145 | __ret = (okfn)(skb); \ | |
146 | __ret;}) | |
147 | #define NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, thresh) \ | |
148 | ({int __ret; \ | |
149 | if ((__ret=nf_hook_slow(pf, hook, &(skb), indev, outdev, okfn, thresh)) == 1) \ | |
150 | __ret = (okfn)(skb); \ | |
151 | __ret;}) | |
152 | #else | |
153 | #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) \ | |
154 | ({int __ret; \ | |
155 | if (list_empty(&nf_hooks[pf][hook]) || \ | |
156 | (__ret=nf_hook_slow(pf, hook, &(skb), indev, outdev, okfn, INT_MIN)) == 1) \ | |
157 | __ret = (okfn)(skb); \ | |
158 | __ret;}) | |
159 | #define NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, thresh) \ | |
160 | ({int __ret; \ | |
161 | if (list_empty(&nf_hooks[pf][hook]) || \ | |
162 | (__ret=nf_hook_slow(pf, hook, &(skb), indev, outdev, okfn, thresh)) == 1) \ | |
163 | __ret = (okfn)(skb); \ | |
164 | __ret;}) | |
165 | #endif | |
166 | ||
167 | int nf_hook_slow(int pf, unsigned int hook, struct sk_buff **pskb, | |
168 | struct net_device *indev, struct net_device *outdev, | |
169 | int (*okfn)(struct sk_buff *), int thresh); | |
170 | ||
171 | /* Call setsockopt() */ | |
172 | int nf_setsockopt(struct sock *sk, int pf, int optval, char __user *opt, | |
173 | int len); | |
174 | int nf_getsockopt(struct sock *sk, int pf, int optval, char __user *opt, | |
175 | int *len); | |
176 | ||
177 | /* Packet queuing */ | |
178 | typedef int (*nf_queue_outfn_t)(struct sk_buff *skb, | |
179 | struct nf_info *info, void *data); | |
180 | extern int nf_register_queue_handler(int pf, | |
181 | nf_queue_outfn_t outfn, void *data); | |
182 | extern int nf_unregister_queue_handler(int pf); | |
183 | extern void nf_reinject(struct sk_buff *skb, | |
184 | struct nf_info *info, | |
185 | unsigned int verdict); | |
186 | ||
187 | extern void (*ip_ct_attach)(struct sk_buff *, struct sk_buff *); | |
188 | extern void nf_ct_attach(struct sk_buff *, struct sk_buff *); | |
189 | ||
190 | /* FIXME: Before cache is ever used, this must be implemented for real. */ | |
191 | extern void nf_invalidate_cache(int pf); | |
192 | ||
193 | #else /* !CONFIG_NETFILTER */ | |
194 | #define NF_HOOK(pf, hook, skb, indev, outdev, okfn) (okfn)(skb) | |
195 | static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {} | |
196 | #endif /*CONFIG_NETFILTER*/ | |
197 | ||
198 | #endif /*__KERNEL__*/ | |
199 | #endif /*__LINUX_NETFILTER_H*/ |