/*
 * space - determine free space on a filesystem
 *
 * Copyright (C) 1992/93/94 Stephen Hebditch <steveh@tqmcomms.co.uk>.
 * All rights reserved. TQM Communications, BCM Box 225, London, WC1N 3XX.
 *
 * See README for more information and disclaimers
 *
 * This routine determines if there is enough space on the filesystem
 * holding the news spool for a new batch of incoming articles.
 * It is based on space.c in the NNTP reference implementation which
 * credits Stan Barber <sob@bcm.tmc.edu>, Tad Guy <tadguy@cs.odu.edu>,
 * Chris Jepeway <jepeway@utkcs2.cs.utk.edu> and Tom Lane <tgl@cs.cmu.edu>
 * but has been heavily cleaned up and support for SVR4, Linux and
 * BSDI added.
 *
 * $Id: space.c,v 1.9 1995/01/10 13:16:51 root Exp $
 *
 * $Log: space.c,v $
 * Revision 1.9  1995/01/10  13:16:51  root
 * Moved includes from slurp.h.
 * Added support for AIX, FreeBSD and NetBSD.
 * General tidying-up.
 *
 * Revision 1.7  1993/06/14  15:25:42  root
 * Added routine name to error messages.
 * Made close() consistent with usage elsewhere.
 *
 * Revision 1.6  1993/04/22  18:27:21  root
 * Changed NeXT define to __NeXT__.
 *
 * Revision 1.5  1993/03/01  18:08:20  root
 * Completely reworked from the original and heavily tidied up.
 * Support added for SVR4 and Linux.
 *
 * Revision 1.4  1993/02/14  16:12:20  root
 * Added support for BSDI.
 */

#include "conf.h"

/* POSIX headers */

#undef _POSIX_SOURCE
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <limits.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

/* Local headers */

#include "slurp.h"
#include "syslog.h"


#ifdef MINFREE

#define DFREE_OK		0
#define DFREE_INODES	1
#define DFREE_BLOCKS	2
#define DFREE_ERR		3

/*
 * Definitions for use with dfree() for various UNIX families.
 *
 * statfilesys		Routine to call when trying to stat a file system
 *					to get the number of free blocks available.
 * statfs_type		The data type into which statfs() wants to return
 *					useful information.
 * bombed			Boolean expression returning 1 if a call to statfs()
 *					fails.
 * blkavail			Given a statfs_type called fs, return number of free
 *					blocks available to a non-superuser.
 * filavail			Given a statfs_type called fs, return number of free
 *					inodes available to a non-superuser.
 */

	#if defined (SVR4)
		#include <sys/statvfs.h>
		#define statfilesys		statvfs
		typedef struct statvfs 	statfs_type;
		#define bombed(call)	((call) == -1)
		#define blkavail(fs)	((fs).f_bavail)
		#define filavail(fs)	((fs).f_favail)

	#elif defined (sun) || defined (hpux) || defined (pyr) || defined (hp300) || defined (__NeXT__) || defined (linux)
		#include <sys/vfs.h>
		#define statfilesys		statfs
		typedef struct statfs 	statfs_type;
		#define bombed(call)	((call) == -1)
		#define blkavail(fs)	((fs).f_bavail)
		#define filavail(fs)	((fs).f_ffree)

	#elif defined (apollo) || defined (_AIX)
		#include <sys/types.h>
		#include <sys/statfs.h>
		#define statfilesys(a,b) statfs (a, b, sizeof (struct statfs), 0)
		typedef struct statfs 	statfs_type;
		#define bombed(call)	((call) == -1)
		#define blkavail(fs)	((fs).f_bfree)
		#define filavail(fs)	((fs).f_ffree)

	#elif defined (ultrix)
		#include <sys/param.h>
		#include <sys/mount.h>
		typedef struct fs_data	statfs_type;
		#define statfilesys		statfs
		#define bombed(call)	((call) <= 0)
		#define blkavail(fs)	((int)((fs).fd_req.bfreen))
		#define filavail(fs)	((int)((fs).fd_req.gfree))

	#elif defined (__bsdi__) || defined (__FreeBSD__) || defined (__NetBSD__)
		#include <sys/param.h>
		#include <sys/mount.h>
		typedef struct statfs	statfs_type;
		#define statfilesys		statfs
		#define bombed(call)	((call) < 0)
		#define blkavail(fs)	((int)((fs).f_bfree))
		#define filavail(fs)	((int)((fs).f_ffree))

	#elif defined (SVR3)
		#include <ustat.h>
		typedef struct ustat statfs_type;
			int
		statfilesys (char *dir, statfs_type *fs)
			{
			struct stat file;
			if (stat (dir, &file))
				return (-1);
			if (ustat (file.st_dev, fs))
				return (-2);
			return (0);
			}
		#define bombed(call)	(call != 0)
		#define blkavail(fs)	((fs).f_tfree)
		#define filavail(fs)	((fs).f_tinode)	

	#else
		SPACE DEFINITIONS NOT AVAILABLE FOR THIS MACHINE OR NOT SET CORRECTLY
	#endif


/*
 * dfree - Return the free space available on the file system containing
 * the specified directory. Space is measured in kilobytes. A negative
 * value is returned if there is an error.
 */

	static int
dfree (char *location, int free_space)
	{
	statfs_type fsys;

	/* Return error if can't get file system info */
	if (bombed (statfilesys (location, &fsys)))
		return (DFREE_ERR);

	/* If able to test if free inodes then do so */
#if defined (filfree) && defined (MINFILES)
	if (filfree (fsys) < MINFILES )
 		return (DFREE_INODES);
#endif

	/* Test if blocks are available */
	if (blkavail (fsys) < free_space)
		return (DFREE_BLOCKS);

	return (DFREE_OK);
	}


/*
 * space - Returns 1 if there are a sufficient number of free blocks
 * and inodes on the filesystem containing the news spool, or 0 if
 * there are only a small number of blocks / inodes remaining.
 */

	int
space (int min_free)
	{
	switch (dfree (SPOOLDIR, min_free))
		{
		case DFREE_OK:
			return (1);
		case DFREE_ERR:
			log_ret ("space: dfree failed due to system call error");
			break;
		case DFREE_INODES:
			log_msg ("space: no inodes on %s", SPOOLDIR);
			break;
		case DFREE_BLOCKS:
			log_msg ("space: no space on %s", SPOOLDIR);
			break;
		}
	return (0);
	}

#endif /* MINFREE */

/* END-OF-FILE */