/* Copyright (C) 2005, 2006 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#ifndef	_SYS_INOTIFY_H
#define	_SYS_INOTIFY_H	1

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/fcntl.h>
#include <sys/ioctl.h>
#include <stdint.h>
#include <errno.h>


/* Structure describing an inotify event.  */
struct inotify_event
{
  int wd;		/* Watch descriptor.  */
  uint32_t mask;	/* Watch mask.  */
  uint32_t cookie;	/* Cookie to synchronize two events.  */
  uint32_t len;		/* Length (including NULs) of name.  */
  char name __flexarr;	/* Name.  */
};


/* Supported events suitable for MASK parameter of INOTIFY_ADD_WATCH.  */
#define IN_ACCESS	 0x00000001	/* File was accessed.  */
#define IN_MODIFY	 0x00000002	/* File was modified.  */
#define IN_ATTRIB	 0x00000004	/* Metadata changed.  */
#define IN_CLOSE_WRITE	 0x00000008	/* Writtable file was closed.  */
#define IN_CLOSE_NOWRITE 0x00000010	/* Unwrittable file closed.  */
#define IN_CLOSE	 (IN_CLOSE_WRITE | IN_CLOSE_NOWRITE) /* Close.  */
#define IN_OPEN		 0x00000020	/* File was opened.  */
#define IN_MOVED_FROM	 0x00000040	/* File was moved from X.  */
#define IN_MOVED_TO      0x00000080	/* File was moved to Y.  */
#define IN_MOVE		 (IN_MOVED_FROM | IN_MOVED_TO) /* Moves.  */
#define IN_CREATE	 0x00000100	/* Subfile was created.  */
#define IN_DELETE	 0x00000200	/* Subfile was deleted.  */
#define IN_DELETE_SELF	 0x00000400	/* Self was deleted.  */
#define IN_MOVE_SELF	 0x00000800	/* Self was moved.  */

/* Events sent by the kernel.  */
#define IN_UNMOUNT	 0x00002000	/* Backing fs was unmounted.  */
#define IN_Q_OVERFLOW	 0x00004000	/* Event queued overflowed.  */
#define IN_IGNORED	 0x00008000	/* File was ignored.  */

/* Helper events.  */
#define IN_CLOSE	 (IN_CLOSE_WRITE | IN_CLOSE_NOWRITE)	/* Close.  */
#define IN_MOVE		 (IN_MOVED_FROM | IN_MOVED_TO)		/* Moves.  */

/* Special flags.  */
#define IN_ONLYDIR	 0x01000000	/* Only watch the path if it is a
					   directory.  */
#define IN_DONT_FOLLOW	 0x02000000	/* Do not follow a sym link.  */
#define IN_MASK_ADD	 0x20000000	/* Add to the mask of an already
					   existing watch.  */
#define IN_ISDIR	 0x40000000	/* Event occurred against dir.  */
#define IN_ONESHOT	 0x80000000	/* Only send event once.  */

/* All events which a program can wait on.  */
#define IN_ALL_EVENTS	 (IN_ACCESS | IN_MODIFY | IN_ATTRIB | IN_CLOSE_WRITE  \
			  | IN_CLOSE_NOWRITE | IN_OPEN | IN_MOVED_FROM	      \
			  | IN_MOVED_TO | IN_CREATE | IN_DELETE		      \
			  | IN_DELETE_SELF | IN_MOVE_SELF)


struct inotify_watch_request {
       int             fd;             /* fd of filename to watch */
       uint32_t           mask;           /* event mask */
};

#define INOTIFY_IOCTL_MAGIC    'Q' 
#define INOTIFY_IOCTL_MAXNR    2

#define INOTIFY_WATCH                  _IOR(INOTIFY_IOCTL_MAGIC, 1, struct inotify_watch_request)
#define INOTIFY_IGNORE                 _IOR(INOTIFY_IOCTL_MAGIC, 2, int)

#define INOTIFY_DEV		"/dev/inotify"

static inline int inotify_init (void)
{
    int fd;
    fd = open(INOTIFY_DEV, O_RDONLY);
    if (fd >= 0 || errno != ENOENT)
	return fd;

    if (mknod(INOTIFY_DEV, S_IFCHR, makedev(10, 63)) < 0)
	return -1;

    if (chmod(INOTIFY_DEV, 0666) < 0)
	return -1;

    return open(INOTIFY_DEV, O_RDONLY);
}

static inline int inotify_add_watch (int fd, const char *name, uint32_t mask)
{
    int file_fd;
    int wd;
    struct inotify_watch_request req;
    file_fd = open ( name, O_RDONLY);
    if (file_fd < 0) {
        return file_fd;
    }
    req.fd = file_fd;
    req.mask = mask;
    wd = ioctl (fd, INOTIFY_WATCH, &req);
    close(file_fd); // TODO: do not close file_fd here - this would delete the watch ???
    return wd;
}

static inline int inotify_rm_watch (int fd, uint32_t wd)
{
    return ioctl ( wd, INOTIFY_IGNORE, fd);
}

#endif /* sys/inotify.h */