include/linux/netfilter.h - arm/linux-arm64-legacy - Git at Google

 #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__
 #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 (*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);

 /* 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);

 struct nf_queue_rerouter {
 	void (*save)(const struct sk_buff *skb, struct nf_info *info);
 	int (*reroute)(struct sk_buff **skb, const struct nf_info *info);
 	int rer_size;
 };

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

 extern int nf_register_queue_rerouter(int pf, struct nf_queue_rerouter *rer);
 extern int nf_unregister_queue_rerouter(int pf);

 #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*/
	#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__
	#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 (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);

	/* 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);

	struct nf_queue_rerouter {
	void (save)(const struct sk_buff skb, struct nf_info *info);
	int (reroute)(struct sk_buff skb, const struct nf_info info);
	int rer_size;
	};

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

	extern int nf_register_queue_rerouter(int pf, struct nf_queue_rerouter *rer);
	extern int nf_unregister_queue_rerouter(int pf);

	#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/