#ifndef _LINUX_FANOTIFY_H
  #define _LINUX_FANOTIFY_H
  
  #include <linux/types.h>
  
  /* the following events that user-space can register for */
  #define FAN_ACCESS		0x00000001	/* File was accessed */
  #define FAN_MODIFY		0x00000002	/* File was modified */
  #define FAN_CLOSE_WRITE		0x00000008	/* Unwrittable file closed */
  #define FAN_CLOSE_NOWRITE	0x00000010	/* Writtable file closed */
  #define FAN_OPEN		0x00000020	/* File was opened */
  
  #define FAN_EVENT_ON_CHILD	0x08000000	/* interested in child events */
  
  /* FIXME currently Q's have no limit.... */
  #define FAN_Q_OVERFLOW		0x00004000	/* Event queued overflowed */

  #define FAN_OPEN_PERM		0x00010000	/* File open in perm check */
  #define FAN_ACCESS_PERM		0x00020000	/* File accessed in perm check */

  /* helper events */
  #define FAN_CLOSE		(FAN_CLOSE_WRITE | FAN_CLOSE_NOWRITE) /* close */

  /* flags used for fanotify_init() */

  #define FAN_CLOEXEC		0x00000001
  #define FAN_NONBLOCK		0x00000002
  
  #define FAN_ALL_INIT_FLAGS	(FAN_CLOEXEC | FAN_NONBLOCK)

  
  /* flags used for fanotify_modify_mark() */
  #define FAN_MARK_ADD		0x00000001
  #define FAN_MARK_REMOVE		0x00000002
  #define FAN_MARK_DONT_FOLLOW	0x00000004
  #define FAN_MARK_ONLYDIR	0x00000008

  #define FAN_MARK_MOUNT		0x00000010

  #define FAN_MARK_IGNORED_MASK	0x00000020

  #define FAN_MARK_IGNORED_SURV_MODIFY	0x00000040

  #define FAN_MARK_FLUSH		0x00000080

  
  #define FAN_ALL_MARK_FLAGS	(FAN_MARK_ADD |\
  				 FAN_MARK_REMOVE |\
  				 FAN_MARK_DONT_FOLLOW |\

  				 FAN_MARK_ONLYDIR |\

  				 FAN_MARK_MOUNT |\

  				 FAN_MARK_IGNORED_MASK |\
  				 FAN_MARK_IGNORED_SURV_MODIFY)

  /*
   * All of the events - we build the list by hand so that we can add flags in
   * the future and not break backward compatibility.  Apps will get only the
   * events that they originally wanted.  Be sure to add new events here!
   */
  #define FAN_ALL_EVENTS (FAN_ACCESS |\
  			FAN_MODIFY |\
  			FAN_CLOSE |\
  			FAN_OPEN)

  /*
   * All events which require a permission response from userspace
   */
  #define FAN_ALL_PERM_EVENTS (FAN_OPEN_PERM |\
  			     FAN_ACCESS_PERM)

  #define FAN_ALL_OUTGOING_EVENTS	(FAN_ALL_EVENTS |\

  				 FAN_ALL_PERM_EVENTS |\

  				 FAN_Q_OVERFLOW)

  #define FANOTIFY_METADATA_VERSION	2

  
  struct fanotify_event_metadata {
  	__u32 event_len;
  	__u32 vers;

  	__u64 mask;

  	__s32 fd;
  	__s32 pid;

  } __attribute__ ((packed));

  struct fanotify_response {
  	__s32 fd;
  	__u32 response;
  } __attribute__ ((packed));

  /* Legit userspace responses to a _PERM event */
  #define FAN_ALLOW	0x01
  #define FAN_DENY	0x02

  /* Helper functions to deal with fanotify_event_metadata buffers */
  #define FAN_EVENT_METADATA_LEN (sizeof(struct fanotify_event_metadata))
  
  #define FAN_EVENT_NEXT(meta, len) ((len) -= (meta)->event_len, \
  				   (struct fanotify_event_metadata*)(((char *)(meta)) + \
  				   (meta)->event_len))
  
  #define FAN_EVENT_OK(meta, len)	((long)(len) >= (long)FAN_EVENT_METADATA_LEN && \
  				(long)(meta)->event_len >= (long)FAN_EVENT_METADATA_LEN && \
  				(long)(meta)->event_len <= (long)(len))

  #endif /* _LINUX_FANOTIFY_H */