[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

/* we overload the higher bits for encoding auxiliary data such as the queue
 * number. Not nice, but better than additional function arguments. */
#define NF_VERDICT_MASK 0x0000ffff
#define NF_VERDICT_BITS 16

#define NF_VERDICT_QMASK 0xffff0000
#define NF_VERDICT_QBITS 16

#define NF_QUEUE_NR(x) (((x << NF_VERDICT_QBITS) & NF_VERDICT_QMASK) | NF_QUEUE)

/* 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__
#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 (*compat_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);
	int (*compat_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);
int nf_register_hooks(struct nf_hook_ops *reg, unsigned int n);
void nf_unregister_hooks(struct nf_hook_ops *reg, unsigned int n);

/* 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];

/* those NF_LOG_* defines and struct nf_loginfo are legacy definitios that will
 * disappear once iptables is replaced with pkttables.  Please DO NOT use them
 * for any new code! */
#define NF_LOG_TCPSEQ		0x01	/* Log TCP sequence numbers */
#define NF_LOG_TCPOPT		0x02	/* Log TCP options */
#define NF_LOG_IPOPT		0x04	/* Log IP options */
#define NF_LOG_UID		0x08	/* Log UID owning local socket */
#define NF_LOG_MASK		0x0f

#define NF_LOG_TYPE_LOG		0x01
#define NF_LOG_TYPE_ULOG	0x02

struct nf_loginfo {
	u_int8_t type;
	union {
		struct {
			u_int32_t copy_len;
			u_int16_t group;
			u_int16_t qthreshold;
		} ulog;
		struct {
			u_int8_t level;
			u_int8_t logflags;
		} log;
	} u;
};

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

struct nf_logger {
	struct module	*me;
	nf_logfn 	*logfn;
	char		*name;
};

/* Function to register/unregister log function. */
int nf_log_register(int pf, struct nf_logger *logger);
int nf_log_unregister_pf(int pf);
void nf_log_unregister_logger(struct nf_logger *logger);

/* 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,
		   struct nf_loginfo *li,
		   const char *fmt, ...);

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);

/**
 *	nf_hook_thresh - call a netfilter hook
 *	
 *	Returns 1 if the hook has allowed the packet to pass.  The function
 *	okfn must be invoked by the caller in this case.  Any other return
 *	value indicates the packet has been consumed by the hook.
 */
static inline int nf_hook_thresh(int pf, unsigned int hook,
				 struct sk_buff **pskb,
				 struct net_device *indev,
				 struct net_device *outdev,
				 int (*okfn)(struct sk_buff *), int thresh,
				 int cond)
{
	if (!cond)
		return 1;
#ifndef CONFIG_NETFILTER_DEBUG
	if (list_empty(&nf_hooks[pf][hook]))
		return 1;
#endif
	return nf_hook_slow(pf, hook, pskb, indev, outdev, okfn, thresh);
}

static inline int nf_hook(int pf, unsigned int hook, struct sk_buff **pskb,
			  struct net_device *indev, struct net_device *outdev,
			  int (*okfn)(struct sk_buff *))
{
	return nf_hook_thresh(pf, hook, pskb, indev, outdev, okfn, INT_MIN, 1);
}
                   
/* 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 */

/* HX: It's slightly less gross now. */

#define NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, thresh)	       \
({int __ret;								       \
if ((__ret=nf_hook_thresh(pf, hook, &(skb), indev, outdev, okfn, thresh, 1)) == 1)\
	__ret = (okfn)(skb);						       \
__ret;})

#define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond)		       \
({int __ret;								       \
if ((__ret=nf_hook_thresh(pf, hook, &(skb), indev, outdev, okfn, INT_MIN, cond)) == 1)\
	__ret = (okfn)(skb);						       \
__ret;})

#define NF_HOOK(pf, hook, skb, indev, outdev, okfn) \
	NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, INT_MIN)

/* 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);

int compat_nf_setsockopt(struct sock *sk, int pf, int optval,
		char __user *opt, int len);
int compat_nf_getsockopt(struct sock *sk, int pf, int optval,
		char __user *opt, int *len);

/* Packet queuing */
struct nf_queue_handler {
	int (*outfn)(struct sk_buff *skb, struct nf_info *info,
		     unsigned int queuenum, void *data);
	void *data;
	char *name;
};
extern int nf_register_queue_handler(int pf, 
                                     struct nf_queue_handler *qh);
extern int nf_unregister_queue_handler(int pf);
extern void nf_unregister_queue_handlers(struct nf_queue_handler *qh);
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);

extern u_int16_t nf_csum_update(u_int32_t oldval, u_int32_t newval,
				u_int32_t csum);
extern u_int16_t nf_proto_csum_update(struct sk_buff *skb,
				      u_int32_t oldval, u_int32_t newval,
				      u_int16_t csum, int pseudohdr);

struct nf_afinfo {
	unsigned short	family;
	unsigned int	(*checksum)(struct sk_buff *skb, unsigned int hook,
				    unsigned int dataoff, u_int8_t protocol);
	void		(*saveroute)(const struct sk_buff *skb,
				     struct nf_info *info);
	int		(*reroute)(struct sk_buff **skb,
				   const struct nf_info *info);
	int		route_key_size;
};

extern struct nf_afinfo *nf_afinfo[];
static inline struct nf_afinfo *nf_get_afinfo(unsigned short family)
{
	return rcu_dereference(nf_afinfo[family]);
}

static inline unsigned int
nf_checksum(struct sk_buff *skb, unsigned int hook, unsigned int dataoff,
	    u_int8_t protocol, unsigned short family)
{
	struct nf_afinfo *afinfo;
	unsigned int csum = 0;

	rcu_read_lock();
	afinfo = nf_get_afinfo(family);
	if (afinfo)
		csum = afinfo->checksum(skb, hook, dataoff, protocol);
	rcu_read_unlock();
	return csum;
}

extern int nf_register_afinfo(struct nf_afinfo *afinfo);
extern void nf_unregister_afinfo(struct nf_afinfo *afinfo);

#define nf_info_reroute(x) ((void *)x + sizeof(struct nf_info))

#include <net/flow.h>
extern void (*ip_nat_decode_session)(struct sk_buff *, struct flowi *);

static inline void
nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, int family)
{
#ifdef CONFIG_IP_NF_NAT_NEEDED
	void (*decodefn)(struct sk_buff *, struct flowi *);

	if (family == AF_INET && (decodefn = ip_nat_decode_session) != NULL)
		decodefn(skb, fl);
#endif
}

#ifdef CONFIG_PROC_FS
#include <linux/proc_fs.h>
extern struct proc_dir_entry *proc_net_netfilter;
#endif

#else /* !CONFIG_NETFILTER */
#define NF_HOOK(pf, hook, skb, indev, outdev, okfn) (okfn)(skb)
#define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond) (okfn)(skb)
static inline int nf_hook_thresh(int pf, unsigned int hook,
				 struct sk_buff **pskb,
				 struct net_device *indev,
				 struct net_device *outdev,
				 int (*okfn)(struct sk_buff *), int thresh,
				 int cond)
{
	return okfn(*pskb);
}
static inline int nf_hook(int pf, unsigned int hook, struct sk_buff **pskb,
			  struct net_device *indev, struct net_device *outdev,
			  int (*okfn)(struct sk_buff *))
{
	return 1;
}
static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
struct flowi;
static inline void
nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, int family) {}
#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
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 */
6869c4d8 HW	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
1da177e4 LT	42	#ifdef __KERNEL__
1da177e4 LT	43	#ifdef CONFIG_NETFILTER
	44
	45	extern void netfilter_init(void);
	46
	47	/* Largest hook number + 1 */
	48	#define NF_MAX_HOOKS 8
	49
	50	struct sk_buff;
	51	struct net_device;
	52
	53	typedef unsigned int nf_hookfn(unsigned int hooknum,
	54	struct sk_buff **skb,
	55	const struct net_device *in,
	56	const struct net_device *out,
	57	int (okfn)(struct sk_buff ));
	58
	59	struct nf_hook_ops
	60	{
	61	struct list_head list;
	62
	63	/* User fills in from here down. */
	64	nf_hookfn *hook;
	65	struct module *owner;
	66	int pf;
	67	int hooknum;
	68	/* Hooks are ordered in ascending priority. */
	69	int priority;
	70	};
	71
	72	struct nf_sockopt_ops
	73	{
	74	struct list_head list;
	75
	76	int pf;
	77
	78	/* Non-inclusive ranges: use 0/0/NULL to never get called. */
	79	int set_optmin;
	80	int set_optmax;
	81	int (set)(struct sock sk, int optval, void __user *user, unsigned int len);
3fdadf7d DM	82	int (compat_set)(struct sock sk, int optval,
3fdadf7d DM	83	void __user *user, unsigned int len);
1da177e4 LT	84
	85	int get_optmin;
	86	int get_optmax;
	87	int (get)(struct sock sk, int optval, void __user user, int len);
3fdadf7d DM	88	int (compat_get)(struct sock sk, int optval,
3fdadf7d DM	89	void __user user, int len);
1da177e4 LT	90
	91	/* Number of users inside set() or get(). */
	92	unsigned int use;
	93	struct task_struct *cleanup_task;
	94	};
	95
	96	/* Each queued (to userspace) skbuff has one of these. */
	97	struct nf_info
	98	{
	99	/* The ops struct which sent us to userspace. */
	100	struct nf_hook_ops *elem;
	101
	102	/* If we're sent to userspace, this keeps housekeeping info */
	103	int pf;
	104	unsigned int hook;
	105	struct net_device indev, outdev;
	106	int (okfn)(struct sk_buff );
	107	};
	108
	109	/* Function to register/unregister hook points. */
	110	int nf_register_hook(struct nf_hook_ops *reg);
	111	void nf_unregister_hook(struct nf_hook_ops *reg);
972d1cb1 PM	112	int nf_register_hooks(struct nf_hook_ops *reg, unsigned int n);
972d1cb1 PM	113	void nf_unregister_hooks(struct nf_hook_ops *reg, unsigned int n);
1da177e4 LT	114
	115	/* Functions to register get/setsockopt ranges (non-inclusive). You
	116	need to check permissions yourself! */
	117	int nf_register_sockopt(struct nf_sockopt_ops *reg);
	118	void nf_unregister_sockopt(struct nf_sockopt_ops *reg);
	119
	120	extern struct list_head nf_hooks[NPROTO][NF_MAX_HOOKS];
	121
608c8e4f HW	122	/* those NF_LOG_* defines and struct nf_loginfo are legacy definitios that will
	123	* disappear once iptables is replaced with pkttables. Please DO NOT use them
	124	* for any new code! */
	125	#define NF_LOG_TCPSEQ 0x01 /* Log TCP sequence numbers */
	126	#define NF_LOG_TCPOPT 0x02 /* Log TCP options */
	127	#define NF_LOG_IPOPT 0x04 /* Log IP options */
	128	#define NF_LOG_UID 0x08 /* Log UID owning local socket */
	129	#define NF_LOG_MASK 0x0f
	130
	131	#define NF_LOG_TYPE_LOG 0x01
	132	#define NF_LOG_TYPE_ULOG 0x02
	133
	134	struct nf_loginfo {
	135	u_int8_t type;
	136	union {
	137	struct {
	138	u_int32_t copy_len;
	139	u_int16_t group;
	140	u_int16_t qthreshold;
	141	} ulog;
	142	struct {
	143	u_int8_t level;
	144	u_int8_t logflags;
	145	} log;
	146	} u;
	147	};
	148
	149	typedef void nf_logfn(unsigned int pf,
	150	unsigned int hooknum,
1da177e4 LT	151	const struct sk_buff *skb,
	152	const struct net_device *in,
	153	const struct net_device *out,
608c8e4f	154	const struct nf_loginfo *li,
1da177e4 LT	155	const char *prefix);
1da177e4 LT	156
608c8e4f HW	157	struct nf_logger {
	158	struct module *me;
	159	nf_logfn *logfn;
	160	char *name;
	161	};
	162
1da177e4	163	/* Function to register/unregister log function. */
608c8e4f	164	int nf_log_register(int pf, struct nf_logger *logger);
8a61fadb	165	int nf_log_unregister_pf(int pf);
608c8e4f	166	void nf_log_unregister_logger(struct nf_logger *logger);
1da177e4 LT	167
	168	/* Calls the registered backend logging function */
	169	void nf_log_packet(int pf,
	170	unsigned int hooknum,
	171	const struct sk_buff *skb,
	172	const struct net_device *in,
	173	const struct net_device *out,
608c8e4f	174	struct nf_loginfo *li,
1da177e4	175	const char *fmt, ...);
16a6677f PM	176
	177	int nf_hook_slow(int pf, unsigned int hook, struct sk_buff **pskb,
	178	struct net_device indev, struct net_device outdev,
	179	int (okfn)(struct sk_buff ), int thresh);
	180
	181	/**
	182	* nf_hook_thresh - call a netfilter hook
	183	*
	184	* Returns 1 if the hook has allowed the packet to pass. The function
	185	* okfn must be invoked by the caller in this case. Any other return
	186	* value indicates the packet has been consumed by the hook.
	187	*/
	188	static inline int nf_hook_thresh(int pf, unsigned int hook,
	189	struct sk_buff **pskb,
	190	struct net_device *indev,
	191	struct net_device *outdev,
48d5cad8 PM	192	int (okfn)(struct sk_buff ), int thresh,
48d5cad8 PM	193	int cond)
16a6677f	194	{
48d5cad8 PM	195	if (!cond)
48d5cad8 PM	196	return 1;
16a6677f PM	197	#ifndef CONFIG_NETFILTER_DEBUG
	198	if (list_empty(&nf_hooks[pf][hook]))
	199	return 1;
	200	#endif
	201	return nf_hook_slow(pf, hook, pskb, indev, outdev, okfn, thresh);
	202	}
	203
	204	static inline int nf_hook(int pf, unsigned int hook, struct sk_buff **pskb,
	205	struct net_device indev, struct net_device outdev,
	206	int (okfn)(struct sk_buff ))
	207	{
48d5cad8	208	return nf_hook_thresh(pf, hook, pskb, indev, outdev, okfn, INT_MIN, 1);
16a6677f	209	}
1da177e4 LT	210
	211	/* Activate hook; either okfn or kfree_skb called, unless a hook
	212	returns NF_STOLEN (in which case, it's up to the hook to deal with
	213	the consequences).
	214
	215	Returns -ERRNO if packet dropped. Zero means queued, stolen or
	216	accepted.
	217	*/
	218
	219	/* RR:
	220	> I don't want nf_hook to return anything because people might forget
	221	> about async and trust the return value to mean "packet was ok".
	222
	223	AK:
	224	Just document it clearly, then you can expect some sense from kernel
	225	coders :)
	226	*/
	227
	228	/* This is gross, but inline doesn't cut it for avoiding the function
	229	call in fast path: gcc doesn't inline (needs value tracking?). --RR */
16a6677f PM	230
	231	/* HX: It's slightly less gross now. */
	232
1da177e4 LT	233	#define NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, thresh) \
1da177e4 LT	234	({int __ret; \
48d5cad8 PM	235	if ((__ret=nf_hook_thresh(pf, hook, &(skb), indev, outdev, okfn, thresh, 1)) == 1)\
	236	__ret = (okfn)(skb); \
	237	__ret;})
	238
	239	#define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond) \
	240	({int __ret; \
	241	if ((__ret=nf_hook_thresh(pf, hook, &(skb), indev, outdev, okfn, INT_MIN, cond)) == 1)\
1da177e4 LT	242	__ret = (okfn)(skb); \
1da177e4 LT	243	__ret;})
1da177e4	244
16a6677f PM	245	#define NF_HOOK(pf, hook, skb, indev, outdev, okfn) \
16a6677f PM	246	NF_HOOK_THRESH(pf, hook, skb, indev, outdev, okfn, INT_MIN)
1da177e4 LT	247
	248	/* Call setsockopt() */
	249	int nf_setsockopt(struct sock sk, int pf, int optval, char __user opt,
	250	int len);
	251	int nf_getsockopt(struct sock sk, int pf, int optval, char __user opt,
	252	int *len);
	253
3fdadf7d DM	254	int compat_nf_setsockopt(struct sock *sk, int pf, int optval,
	255	char __user *opt, int len);
	256	int compat_nf_getsockopt(struct sock *sk, int pf, int optval,
	257	char __user opt, int len);
	258
1da177e4	259	/* Packet queuing */
bbd86b9f HW	260	struct nf_queue_handler {
	261	int (outfn)(struct sk_buff skb, struct nf_info *info,
	262	unsigned int queuenum, void *data);
	263	void *data;
	264	char *name;
	265	};
1da177e4	266	extern int nf_register_queue_handler(int pf,
bbd86b9f	267	struct nf_queue_handler *qh);
1da177e4	268	extern int nf_unregister_queue_handler(int pf);
bbd86b9f	269	extern void nf_unregister_queue_handlers(struct nf_queue_handler *qh);
1da177e4 LT	270	extern void nf_reinject(struct sk_buff *skb,
	271	struct nf_info *info,
	272	unsigned int verdict);
	273
	274	extern void (ip_ct_attach)(struct sk_buff , struct sk_buff *);
	275	extern void nf_ct_attach(struct sk_buff , struct sk_buff );
	276
	277	/* FIXME: Before cache is ever used, this must be implemented for real. */
	278	extern void nf_invalidate_cache(int pf);
	279
089af26c HW	280	/* Call this before modifying an existing packet: ensures it is
	281	modifiable and linear to the point you care about (writable_len).
	282	Returns true or false. */
	283	extern int skb_make_writable(struct sk_buff **pskb, unsigned int writable_len);
	284
4cf411de PM	285	extern u_int16_t nf_csum_update(u_int32_t oldval, u_int32_t newval,
	286	u_int32_t csum);
	287	extern u_int16_t nf_proto_csum_update(struct sk_buff *skb,
	288	u_int32_t oldval, u_int32_t newval,
	289	u_int16_t csum, int pseudohdr);
	290
bce8032e PM	291	struct nf_afinfo {
bce8032e PM	292	unsigned short family;
422c346f PM	293	unsigned int (checksum)(struct sk_buff skb, unsigned int hook,
422c346f PM	294	unsigned int dataoff, u_int8_t protocol);
bce8032e PM	295	void (saveroute)(const struct sk_buff skb,
	296	struct nf_info *info);
	297	int (reroute)(struct sk_buff *skb,
	298	const struct nf_info *info);
	299	int route_key_size;
2cc7d573 HW	300	};
2cc7d573 HW	301
bce8032e PM	302	extern struct nf_afinfo *nf_afinfo[];
	303	static inline struct nf_afinfo *nf_get_afinfo(unsigned short family)
	304	{
	305	return rcu_dereference(nf_afinfo[family]);
	306	}
2cc7d573	307
422c346f PM	308	static inline unsigned int
	309	nf_checksum(struct sk_buff *skb, unsigned int hook, unsigned int dataoff,
	310	u_int8_t protocol, unsigned short family)
	311	{
	312	struct nf_afinfo *afinfo;
	313	unsigned int csum = 0;
	314
	315	rcu_read_lock();
	316	afinfo = nf_get_afinfo(family);
	317	if (afinfo)
	318	csum = afinfo->checksum(skb, hook, dataoff, protocol);
	319	rcu_read_unlock();
	320	return csum;
	321	}
	322
bce8032e PM	323	extern int nf_register_afinfo(struct nf_afinfo *afinfo);
	324	extern void nf_unregister_afinfo(struct nf_afinfo *afinfo);
	325
	326	#define nf_info_reroute(x) ((void *)x + sizeof(struct nf_info))
2cc7d573	327
eb9c7ebe PM	328	#include <net/flow.h>
	329	extern void (ip_nat_decode_session)(struct sk_buff , struct flowi *);
	330
	331	static inline void
	332	nf_nat_decode_session(struct sk_buff skb, struct flowi fl, int family)
	333	{
	334	#ifdef CONFIG_IP_NF_NAT_NEEDED
	335	void (decodefn)(struct sk_buff , struct flowi *);
	336
	337	if (family == AF_INET && (decodefn = ip_nat_decode_session) != NULL)
	338	decodefn(skb, fl);
	339	#endif
	340	}
	341
608c8e4f HW	342	#ifdef CONFIG_PROC_FS
	343	#include <linux/proc_fs.h>
	344	extern struct proc_dir_entry *proc_net_netfilter;
	345	#endif
	346
1da177e4 LT	347	#else /* !CONFIG_NETFILTER */
1da177e4 LT	348	#define NF_HOOK(pf, hook, skb, indev, outdev, okfn) (okfn)(skb)
48d5cad8	349	#define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond) (okfn)(skb)
f53b61d8 DM	350	static inline int nf_hook_thresh(int pf, unsigned int hook,
	351	struct sk_buff **pskb,
	352	struct net_device *indev,
	353	struct net_device *outdev,
48d5cad8 PM	354	int (okfn)(struct sk_buff ), int thresh,
48d5cad8 PM	355	int cond)
f53b61d8 DM	356	{
	357	return okfn(*pskb);
	358	}
	359	static inline int nf_hook(int pf, unsigned int hook, struct sk_buff **pskb,
	360	struct net_device indev, struct net_device outdev,
	361	int (okfn)(struct sk_buff ))
	362	{
9c92d348	363	return 1;
f53b61d8	364	}
1da177e4	365	static inline void nf_ct_attach(struct sk_buff new, struct sk_buff skb) {}
f53b61d8	366	struct flowi;
eb9c7ebe PM	367	static inline void
eb9c7ebe PM	368	nf_nat_decode_session(struct sk_buff skb, struct flowi fl, int family) {}
1da177e4 LT	369	#endif /CONFIG_NETFILTER/
	370
	371	#endif /__KERNEL__/
	372	#endif /__LINUX_NETFILTER_H/