Linux kernel mirror (for testing)
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linux
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/* 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
34/* only for userspace compatibility */
35#ifndef __KERNEL__
36/* Generic cache responses from hook functions.
37 <= 0x2000 is used for protocol-flags. */
38#define NFC_UNKNOWN 0x4000
39#define NFC_ALTERED 0x8000
40#endif
41
42#ifdef __KERNEL__
43#include <linux/config.h>
44#ifdef CONFIG_NETFILTER
45
46extern void netfilter_init(void);
47
48/* Largest hook number + 1 */
49#define NF_MAX_HOOKS 8
50
51struct sk_buff;
52struct net_device;
53
54typedef 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
60struct 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
73struct 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. */
94struct 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. */
107int nf_register_hook(struct nf_hook_ops *reg);
108void 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! */
112int nf_register_sockopt(struct nf_sockopt_ops *reg);
113void nf_unregister_sockopt(struct nf_sockopt_ops *reg);
114
115extern struct list_head nf_hooks[NPROTO][NF_MAX_HOOKS];
116
117/* those NF_LOG_* defines and struct nf_loginfo are legacy definitios that will
118 * disappear once iptables is replaced with pkttables. Please DO NOT use them
119 * for any new code! */
120#define NF_LOG_TCPSEQ 0x01 /* Log TCP sequence numbers */
121#define NF_LOG_TCPOPT 0x02 /* Log TCP options */
122#define NF_LOG_IPOPT 0x04 /* Log IP options */
123#define NF_LOG_UID 0x08 /* Log UID owning local socket */
124#define NF_LOG_MASK 0x0f
125
126#define NF_LOG_TYPE_LOG 0x01
127#define NF_LOG_TYPE_ULOG 0x02
128
129struct nf_loginfo {
130 u_int8_t type;
131 union {
132 struct {
133 u_int32_t copy_len;
134 u_int16_t group;
135 u_int16_t qthreshold;
136 } ulog;
137 struct {
138 u_int8_t level;
139 u_int8_t logflags;
140 } log;
141 } u;
142};
143
144typedef void nf_logfn(unsigned int pf,
145 unsigned int hooknum,
146 const struct sk_buff *skb,
147 const struct net_device *in,
148 const struct net_device *out,
149 const struct nf_loginfo *li,
150 const char *prefix);
151
152struct nf_logger {
153 struct module *me;
154 nf_logfn *logfn;
155 char *name;
156};
157
158/* Function to register/unregister log function. */
159int nf_log_register(int pf, struct nf_logger *logger);
160int nf_log_unregister_pf(int pf);
161void nf_log_unregister_logger(struct nf_logger *logger);
162
163/* Calls the registered backend logging function */
164void nf_log_packet(int pf,
165 unsigned int hooknum,
166 const struct sk_buff *skb,
167 const struct net_device *in,
168 const struct net_device *out,
169 struct nf_loginfo *li,
170 const char *fmt, ...);
171
172/* Activate hook; either okfn or kfree_skb called, unless a hook
173 returns NF_STOLEN (in which case, it's up to the hook to deal with
174 the consequences).
175
176 Returns -ERRNO if packet dropped. Zero means queued, stolen or
177 accepted.
178*/
179
180/* RR:
181 > I don't want nf_hook to return anything because people might forget
182 > about async and trust the return value to mean "packet was ok".
183
184 AK:
185 Just document it clearly, then you can expect some sense from kernel
186 coders :)
187*/
188
189/* This is gross, but inline doesn't cut it for avoiding the function
190 call in fast path: gcc doesn't inline (needs value tracking?). --RR */
191#ifdef CONFIG_NETFILTER_DEBUG
192#define NF_HOOK(pf, hook, skb, indev, outdev, okfn) \
193({int __ret; \
194if ((__ret=nf_hook_slow(pf, hook, &(skb), indev, outdev, okfn, INT_MIN)) == 1) \
195 __ret = (okfn)(skb); \
196__ret;})
197#define NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, thresh) \
198({int __ret; \
199if ((__ret=nf_hook_slow(pf, hook, &(skb), indev, outdev, okfn, thresh)) == 1) \
200 __ret = (okfn)(skb); \
201__ret;})
202#else
203#define NF_HOOK(pf, hook, skb, indev, outdev, okfn) \
204({int __ret; \
205if (list_empty(&nf_hooks[pf][hook]) || \
206 (__ret=nf_hook_slow(pf, hook, &(skb), indev, outdev, okfn, INT_MIN)) == 1) \
207 __ret = (okfn)(skb); \
208__ret;})
209#define NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, thresh) \
210({int __ret; \
211if (list_empty(&nf_hooks[pf][hook]) || \
212 (__ret=nf_hook_slow(pf, hook, &(skb), indev, outdev, okfn, thresh)) == 1) \
213 __ret = (okfn)(skb); \
214__ret;})
215#endif
216
217int nf_hook_slow(int pf, unsigned int hook, struct sk_buff **pskb,
218 struct net_device *indev, struct net_device *outdev,
219 int (*okfn)(struct sk_buff *), int thresh);
220
221/* Call setsockopt() */
222int nf_setsockopt(struct sock *sk, int pf, int optval, char __user *opt,
223 int len);
224int nf_getsockopt(struct sock *sk, int pf, int optval, char __user *opt,
225 int *len);
226
227/* Packet queuing */
228struct nf_queue_handler {
229 int (*outfn)(struct sk_buff *skb, struct nf_info *info,
230 unsigned int queuenum, void *data);
231 void *data;
232 char *name;
233};
234extern int nf_register_queue_handler(int pf,
235 struct nf_queue_handler *qh);
236extern int nf_unregister_queue_handler(int pf);
237extern void nf_unregister_queue_handlers(struct nf_queue_handler *qh);
238extern void nf_reinject(struct sk_buff *skb,
239 struct nf_info *info,
240 unsigned int verdict);
241
242extern void (*ip_ct_attach)(struct sk_buff *, struct sk_buff *);
243extern void nf_ct_attach(struct sk_buff *, struct sk_buff *);
244
245/* FIXME: Before cache is ever used, this must be implemented for real. */
246extern void nf_invalidate_cache(int pf);
247
248/* Call this before modifying an existing packet: ensures it is
249 modifiable and linear to the point you care about (writable_len).
250 Returns true or false. */
251extern int skb_make_writable(struct sk_buff **pskb, unsigned int writable_len);
252
253struct nf_queue_rerouter {
254 void (*save)(const struct sk_buff *skb, struct nf_info *info);
255 int (*reroute)(struct sk_buff **skb, const struct nf_info *info);
256 int rer_size;
257};
258
259#define nf_info_reroute(x) ((void *)x + sizeof(struct nf_info))
260
261extern int nf_register_queue_rerouter(int pf, struct nf_queue_rerouter *rer);
262extern int nf_unregister_queue_rerouter(int pf);
263
264#ifdef CONFIG_PROC_FS
265#include <linux/proc_fs.h>
266extern struct proc_dir_entry *proc_net_netfilter;
267#endif
268
269#else /* !CONFIG_NETFILTER */
270#define NF_HOOK(pf, hook, skb, indev, outdev, okfn) (okfn)(skb)
271static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
272#endif /*CONFIG_NETFILTER*/
273
274#endif /*__KERNEL__*/
275#endif /*__LINUX_NETFILTER_H*/