[mirror_ubuntu-zesty-kernel.git] / include / linux / netfilter.h

#ifndef __LINUX_NETFILTER_H
#define __LINUX_NETFILTER_H

#ifdef __KERNEL__
#include <linux/init.h>
#include <linux/types.h>
#include <linux/skbuff.h>
#include <linux/net.h>
#include <linux/if.h>
#include <linux/wait.h>
#include <linux/list.h>
#endif
#include <linux/compiler.h>

/* Responses from hook functions. */
#define NF_DROP 0
#define NF_ACCEPT 1
#define NF_STOLEN 2
#define NF_QUEUE 3
#define NF_REPEAT 4
#define NF_STOP 5
#define NF_MAX_VERDICT NF_STOP

/* only for userspace compatibility */
#ifndef __KERNEL__
/* Generic cache responses from hook functions.
   <= 0x2000 is used for protocol-flags. */
#define NFC_UNKNOWN 0x4000
#define NFC_ALTERED 0x8000
#endif

#ifdef __KERNEL__
#include <linux/config.h>
#ifdef CONFIG_NETFILTER

extern void netfilter_init(void);

/* Largest hook number + 1 */
#define NF_MAX_HOOKS 8

struct sk_buff;
struct net_device;

typedef unsigned int nf_hookfn(unsigned int hooknum,
			       struct sk_buff **skb,
			       const struct net_device *in,
			       const struct net_device *out,
			       int (*okfn)(struct sk_buff *));

struct nf_hook_ops
{
	struct list_head list;

	/* User fills in from here down. */
	nf_hookfn *hook;
	struct module *owner;
	int pf;
	int hooknum;
	/* Hooks are ordered in ascending priority. */
	int priority;
};

struct nf_sockopt_ops
{
	struct list_head list;

	int pf;

	/* Non-inclusive ranges: use 0/0/NULL to never get called. */
	int set_optmin;
	int set_optmax;
	int (*set)(struct sock *sk, int optval, void __user *user, unsigned int len);

	int get_optmin;
	int get_optmax;
	int (*get)(struct sock *sk, int optval, void __user *user, int *len);

	/* Number of users inside set() or get(). */
	unsigned int use;
	struct task_struct *cleanup_task;
};

/* Each queued (to userspace) skbuff has one of these. */
struct nf_info
{
	/* The ops struct which sent us to userspace. */
	struct nf_hook_ops *elem;
	
	/* If we're sent to userspace, this keeps housekeeping info */
	int pf;
	unsigned int hook;
	struct net_device *indev, *outdev;
	int (*okfn)(struct sk_buff *);
};
                                                                                
/* Function to register/unregister hook points. */
int nf_register_hook(struct nf_hook_ops *reg);
void nf_unregister_hook(struct nf_hook_ops *reg);

/* Functions to register get/setsockopt ranges (non-inclusive).  You
   need to check permissions yourself! */
int nf_register_sockopt(struct nf_sockopt_ops *reg);
void nf_unregister_sockopt(struct nf_sockopt_ops *reg);

extern struct list_head nf_hooks[NPROTO][NF_MAX_HOOKS];

typedef void nf_logfn(unsigned int hooknum,
		      const struct sk_buff *skb,
		      const struct net_device *in,
		      const struct net_device *out,
		      const char *prefix);

/* Function to register/unregister log function. */
int nf_log_register(int pf, nf_logfn *logfn);
void nf_log_unregister(int pf, nf_logfn *logfn);

/* Calls the registered backend logging function */
void nf_log_packet(int pf,
		   unsigned int hooknum,
		   const struct sk_buff *skb,
		   const struct net_device *in,
		   const struct net_device *out,
		   const char *fmt, ...);
                   
/* Activate hook; either okfn or kfree_skb called, unless a hook
   returns NF_STOLEN (in which case, it's up to the hook to deal with
   the consequences).

   Returns -ERRNO if packet dropped.  Zero means queued, stolen or
   accepted.
*/

/* RR:
   > I don't want nf_hook to return anything because people might forget
   > about async and trust the return value to mean "packet was ok".

   AK:
   Just document it clearly, then you can expect some sense from kernel
   coders :)
*/

/* This is gross, but inline doesn't cut it for avoiding the function
   call in fast path: gcc doesn't inline (needs value tracking?). --RR */
#ifdef CONFIG_NETFILTER_DEBUG
#define NF_HOOK(pf, hook, skb, indev, outdev, okfn)			       \
({int __ret;								       \
if ((__ret=nf_hook_slow(pf, hook, &(skb), indev, outdev, okfn, INT_MIN)) == 1) \
	__ret = (okfn)(skb);						       \
__ret;})
#define NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, thresh)	       \
({int __ret;								       \
if ((__ret=nf_hook_slow(pf, hook, &(skb), indev, outdev, okfn, thresh)) == 1)  \
	__ret = (okfn)(skb);						       \
__ret;})
#else
#define NF_HOOK(pf, hook, skb, indev, outdev, okfn)			       \
({int __ret;								       \
if (list_empty(&nf_hooks[pf][hook]) ||					       \
    (__ret=nf_hook_slow(pf, hook, &(skb), indev, outdev, okfn, INT_MIN)) == 1) \
	__ret = (okfn)(skb);						       \
__ret;})
#define NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, thresh)	       \
({int __ret;								       \
if (list_empty(&nf_hooks[pf][hook]) ||					       \
    (__ret=nf_hook_slow(pf, hook, &(skb), indev, outdev, okfn, thresh)) == 1)  \
	__ret = (okfn)(skb);						       \
__ret;})
#endif

int nf_hook_slow(int pf, unsigned int hook, struct sk_buff **pskb,
		 struct net_device *indev, struct net_device *outdev,
		 int (*okfn)(struct sk_buff *), int thresh);

/* Call setsockopt() */
int nf_setsockopt(struct sock *sk, int pf, int optval, char __user *opt, 
		  int len);
int nf_getsockopt(struct sock *sk, int pf, int optval, char __user *opt,
		  int *len);

/* Packet queuing */
typedef int (*nf_queue_outfn_t)(struct sk_buff *skb, 
                                struct nf_info *info, void *data);
extern int nf_register_queue_handler(int pf, 
                                     nf_queue_outfn_t outfn, void *data);
extern int nf_unregister_queue_handler(int pf);
extern void nf_reinject(struct sk_buff *skb,
			struct nf_info *info,
			unsigned int verdict);

extern void (*ip_ct_attach)(struct sk_buff *, struct sk_buff *);
extern void nf_ct_attach(struct sk_buff *, struct sk_buff *);

/* FIXME: Before cache is ever used, this must be implemented for real. */
extern void nf_invalidate_cache(int pf);

/* Call this before modifying an existing packet: ensures it is
   modifiable and linear to the point you care about (writable_len).
   Returns true or false. */
extern int skb_make_writable(struct sk_buff **pskb, unsigned int writable_len);

#else /* !CONFIG_NETFILTER */
#define NF_HOOK(pf, hook, skb, indev, outdev, okfn) (okfn)(skb)
static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
#endif /*CONFIG_NETFILTER*/

#endif /*__KERNEL__*/
#endif /*__LINUX_NETFILTER_H*/
Commit	Line	Data
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
6869c4d8 HW	24	/* only for userspace compatibility */
6869c4d8 HW	25	#ifndef __KERNEL__
1da177e4 LT	26	/* Generic cache responses from hook functions.
	27	<= 0x2000 is used for protocol-flags. */
	28	#define NFC_UNKNOWN 0x4000
	29	#define NFC_ALTERED 0x8000
6869c4d8	30	#endif
1da177e4 LT	31
	32	#ifdef __KERNEL__
	33	#include <linux/config.h>
	34	#ifdef CONFIG_NETFILTER
	35
	36	extern void netfilter_init(void);
	37
	38	/* Largest hook number + 1 */
	39	#define NF_MAX_HOOKS 8
	40
	41	struct sk_buff;
	42	struct net_device;
	43
	44	typedef unsigned int nf_hookfn(unsigned int hooknum,
	45	struct sk_buff **skb,
	46	const struct net_device *in,
	47	const struct net_device *out,
	48	int (okfn)(struct sk_buff ));
	49
	50	struct nf_hook_ops
	51	{
	52	struct list_head list;
	53
	54	/* User fills in from here down. */
	55	nf_hookfn *hook;
	56	struct module *owner;
	57	int pf;
	58	int hooknum;
	59	/* Hooks are ordered in ascending priority. */
	60	int priority;
	61	};
	62
	63	struct nf_sockopt_ops
	64	{
	65	struct list_head list;
	66
	67	int pf;
	68
	69	/* Non-inclusive ranges: use 0/0/NULL to never get called. */
	70	int set_optmin;
	71	int set_optmax;
	72	int (set)(struct sock sk, int optval, void __user *user, unsigned int len);
	73
	74	int get_optmin;
	75	int get_optmax;
	76	int (get)(struct sock sk, int optval, void __user user, int len);
	77
	78	/* Number of users inside set() or get(). */
	79	unsigned int use;
	80	struct task_struct *cleanup_task;
	81	};
	82
	83	/* Each queued (to userspace) skbuff has one of these. */
	84	struct nf_info
	85	{
	86	/* The ops struct which sent us to userspace. */
	87	struct nf_hook_ops *elem;
	88
	89	/* If we're sent to userspace, this keeps housekeeping info */
	90	int pf;
	91	unsigned int hook;
	92	struct net_device indev, outdev;
	93	int (okfn)(struct sk_buff );
	94	};
95
96	/* Function to register/unregister hook points. */
97	int nf_register_hook(struct nf_hook_ops *reg);
98	void nf_unregister_hook(struct nf_hook_ops *reg);
99
100	/* Functions to register get/setsockopt ranges (non-inclusive). You
101	need to check permissions yourself! */
102	int nf_register_sockopt(struct nf_sockopt_ops *reg);
103	void nf_unregister_sockopt(struct nf_sockopt_ops *reg);
104
105	extern struct list_head nf_hooks[NPROTO][NF_MAX_HOOKS];
106
107	typedef void nf_logfn(unsigned int hooknum,
108	const struct sk_buff *skb,
109	const struct net_device *in,
110	const struct net_device *out,
111	const char *prefix);
112
113	/* Function to register/unregister log function. */
114	int nf_log_register(int pf, nf_logfn *logfn);
115	void nf_log_unregister(int pf, nf_logfn *logfn);
116
117	/* Calls the registered backend logging function */
118	void nf_log_packet(int pf,
119	unsigned int hooknum,
120	const struct sk_buff *skb,
121	const struct net_device *in,
122	const struct net_device *out,
123	const char *fmt, ...);
124
125	/* Activate hook; either okfn or kfree_skb called, unless a hook
126	returns NF_STOLEN (in which case, it's up to the hook to deal with
127	the consequences).
128
129	Returns -ERRNO if packet dropped. Zero means queued, stolen or
130	accepted.
131	*/
132
133	/* RR:
134	> I don't want nf_hook to return anything because people might forget
135	> about async and trust the return value to mean "packet was ok".
136
137	AK:
138	Just document it clearly, then you can expect some sense from kernel
139	coders :)
140	*/
141
142	/* This is gross, but inline doesn't cut it for avoiding the function
143	call in fast path: gcc doesn't inline (needs value tracking?). --RR */
144	#ifdef CONFIG_NETFILTER_DEBUG
145	#define NF_HOOK(pf, hook, skb, indev, outdev, okfn) \
146	({int __ret; \
147	if ((__ret=nf_hook_slow(pf, hook, &(skb), indev, outdev, okfn, INT_MIN)) == 1) \
148	__ret = (okfn)(skb); \
149	__ret;})
150	#define NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, thresh) \
151	({int __ret; \
152	if ((__ret=nf_hook_slow(pf, hook, &(skb), indev, outdev, okfn, thresh)) == 1) \
153	__ret = (okfn)(skb); \
154	__ret;})
155	#else
156	#define NF_HOOK(pf, hook, skb, indev, outdev, okfn) \
157	({int __ret; \
158	if (list_empty(&nf_hooks[pf][hook]) \|\| \
159	(__ret=nf_hook_slow(pf, hook, &(skb), indev, outdev, okfn, INT_MIN)) == 1) \
160	__ret = (okfn)(skb); \
161	__ret;})
162	#define NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, thresh) \
163	({int __ret; \
164	if (list_empty(&nf_hooks[pf][hook]) \|\| \
165	(__ret=nf_hook_slow(pf, hook, &(skb), indev, outdev, okfn, thresh)) == 1) \
166	__ret = (okfn)(skb); \
167	__ret;})
168	#endif
169
170	int nf_hook_slow(int pf, unsigned int hook, struct sk_buff **pskb,
171	struct net_device indev, struct net_device outdev,
172	int (okfn)(struct sk_buff ), int thresh);
173
174	/* Call setsockopt() */
175	int nf_setsockopt(struct sock sk, int pf, int optval, char __user opt,
176	int len);
177	int nf_getsockopt(struct sock sk, int pf, int optval, char __user opt,
178	int *len);
179
180	/* Packet queuing */
181	typedef int (nf_queue_outfn_t)(struct sk_buff skb,
182	struct nf_info info, void data);
183	extern int nf_register_queue_handler(int pf,
184	nf_queue_outfn_t outfn, void *data);
185	extern int nf_unregister_queue_handler(int pf);
186	extern void nf_reinject(struct sk_buff *skb,
187	struct nf_info *info,
188	unsigned int verdict);
189
190	extern void (ip_ct_attach)(struct sk_buff , struct sk_buff *);
191	extern void nf_ct_attach(struct sk_buff , struct sk_buff );
192
193	/* FIXME: Before cache is ever used, this must be implemented for real. */
194	extern void nf_invalidate_cache(int pf);
195
089af26c HW	196	/* Call this before modifying an existing packet: ensures it is
	197	modifiable and linear to the point you care about (writable_len).
	198	Returns true or false. */
	199	extern int skb_make_writable(struct sk_buff **pskb, unsigned int writable_len);
	200
1da177e4 LT	201	#else /* !CONFIG_NETFILTER */
	202	#define NF_HOOK(pf, hook, skb, indev, outdev, okfn) (okfn)(skb)
	203	static inline void nf_ct_attach(struct sk_buff new, struct sk_buff skb) {}
	204	#endif /CONFIG_NETFILTER/
	205
	206	#endif /__KERNEL__/
	207	#endif /__LINUX_NETFILTER_H/