/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
#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_ATTRIB 0x00000004	     /* Metadata changed */
#define FAN_CLOSE_WRITE 0x00000008   /* Writtable file closed */
#define FAN_CLOSE_NOWRITE 0x00000010 /* Unwrittable file closed */
#define FAN_OPEN 0x00000020	     /* File was opened */
#define FAN_MOVED_FROM 0x00000040    /* File was moved from X */
#define FAN_MOVED_TO 0x00000080	     /* File was moved to Y */
#define FAN_CREATE 0x00000100	     /* Subfile was created */
#define FAN_DELETE 0x00000200	     /* Subfile was deleted */
#define FAN_DELETE_SELF 0x00000400   /* Self was deleted */
#define FAN_MOVE_SELF 0x00000800     /* Self was moved */
#define FAN_OPEN_EXEC 0x00001000     /* File was opened for exec */

#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 */
#define FAN_OPEN_EXEC_PERM 0x00040000 /* File open/exec in perm check */

#define FAN_ONDIR 0x40000000 /* event occurred against dir */

#define FAN_EVENT_ON_CHILD 0x08000000 /* interested in child events */

/* helper events */
#define FAN_CLOSE (FAN_CLOSE_WRITE | FAN_CLOSE_NOWRITE) /* close */
#define FAN_MOVE (FAN_MOVED_FROM | FAN_MOVED_TO)	/* moves */

/* flags used for fanotify_init() */
#define FAN_CLOEXEC 0x00000001
#define FAN_NONBLOCK 0x00000002

/* These are NOT bitwise flags.  Both bits are used together.  */
#define FAN_CLASS_NOTIF 0x00000000
#define FAN_CLASS_CONTENT 0x00000004
#define FAN_CLASS_PRE_CONTENT 0x00000008

/* Deprecated - do not use this in programs and do not add new flags here! */
#define FAN_ALL_CLASS_BITS \
	(FAN_CLASS_NOTIF | FAN_CLASS_CONTENT | FAN_CLASS_PRE_CONTENT)

#define FAN_UNLIMITED_QUEUE 0x00000010
#define FAN_UNLIMITED_MARKS 0x00000020
#define FAN_ENABLE_AUDIT 0x00000040

/* Flags to determine fanotify event format */
#define FAN_REPORT_TID 0x00000100     /* event->pid is thread id */
#define FAN_REPORT_FID 0x00000200     /* Report unique file id */
#define FAN_REPORT_DIR_FID 0x00000400 /* Report unique directory id */
#define FAN_REPORT_NAME 0x00000800    /* Report events with name */

/* Convenience macro - FAN_REPORT_NAME requires FAN_REPORT_DIR_FID */
#define FAN_REPORT_DFID_NAME (FAN_REPORT_DIR_FID | FAN_REPORT_NAME)

/* Deprecated - do not use this in programs and do not add new flags here! */
#define FAN_ALL_INIT_FLAGS                                 \
	(FAN_CLOEXEC | FAN_NONBLOCK | FAN_ALL_CLASS_BITS | \
	 FAN_UNLIMITED_QUEUE | FAN_UNLIMITED_MARKS)

/* 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
/* FAN_MARK_MOUNT is		0x00000010 */
#define FAN_MARK_IGNORED_MASK 0x00000020
#define FAN_MARK_IGNORED_SURV_MODIFY 0x00000040
#define FAN_MARK_FLUSH 0x00000080
/* FAN_MARK_FILESYSTEM is	0x00000100 */

/* These are NOT bitwise flags.  Both bits can be used togther.  */
#define FAN_MARK_INODE 0x00000000
#define FAN_MARK_MOUNT 0x00000010
#define FAN_MARK_FILESYSTEM 0x00000100

/* Deprecated - do not use this in programs and do not add new flags here! */
#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 | FAN_MARK_FLUSH)

/* Deprecated - do not use this in programs and do not add new flags here! */
#define FAN_ALL_EVENTS (FAN_ACCESS | FAN_MODIFY | FAN_CLOSE | FAN_OPEN)

/*
 * All events which require a permission response from userspace
 */
/* Deprecated - do not use this in programs and do not add new flags here! */
#define FAN_ALL_PERM_EVENTS (FAN_OPEN_PERM | FAN_ACCESS_PERM)

/* Deprecated - do not use this in programs and do not add new flags here! */
#define FAN_ALL_OUTGOING_EVENTS \
	(FAN_ALL_EVENTS | FAN_ALL_PERM_EVENTS | FAN_Q_OVERFLOW)

#define FANOTIFY_METADATA_VERSION 3

struct fanotify_event_metadata {
	__u32 event_len;
	__u8 vers;
	__u8 reserved;
	__u16 metadata_len;
	__aligned_u64 mask;
	__s32 fd;
	__s32 pid;
};

#define FAN_EVENT_INFO_TYPE_FID 1
#define FAN_EVENT_INFO_TYPE_DFID_NAME 2
#define FAN_EVENT_INFO_TYPE_DFID 3

/* Variable length info record following event metadata */
struct fanotify_event_info_header {
	__u8 info_type;
	__u8 pad;
	__u16 len;
};

/* Unique file identifier info record */
struct fanotify_event_info_fid {
	struct fanotify_event_info_header hdr;
	__kernel_fsid_t fsid;
	/*
	 * Following is an opaque struct file_handle that can be passed as
	 * an argument to open_by_handle_at(2).
	 */
	unsigned char handle[];
};

struct fanotify_response {
	__s32 fd;
	__u32 response;
};

/* Legit userspace responses to a _PERM event */
#define FAN_ALLOW 0x01
#define FAN_DENY 0x02
#define FAN_AUDIT 0x10 /* Bit mask to create audit record for result */

/* No fd set in event */
#define FAN_NOFD -1

/* 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))

