/* 
   Unix SMB/CIFS implementation.
   functions to calculate the free disk space
   Copyright (C) Andrew Tridgell 1998-2000
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
   
   This program 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 General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "includes.h"


/* Return the number of TOSIZE-byte blocks used by
   BLOCKS FROMSIZE-byte blocks, rounding away from zero.
*/
static SMB_BIG_UINT adjust_blocks(SMB_BIG_UINT blocks, SMB_BIG_UINT fromsize, SMB_BIG_UINT tosize)
{
	if (fromsize == tosize)	{ /* e.g., from 512 to 512 */
		return blocks;
	} else if (fromsize > tosize) { /* e.g., from 2048 to 512 */
		return blocks * (fromsize / tosize);
	} else { /* e.g., from 256 to 512 */
		/* Protect against broken filesystems... */
		if (fromsize == 0) {
			fromsize = tosize;
		}
		return (blocks + 1) / (tosize / fromsize);
	}
}

/* this does all of the system specific guff to get the free disk space.
   It is derived from code in the GNU fileutils package, but has been
   considerably mangled for use here 

   results are returned in *dfree and *dsize, in 512 byte units
*/
int sys_fsusage(const char *path, SMB_BIG_UINT *dfree, SMB_BIG_UINT *dsize)
{
#ifdef STAT_STATFS3_OSF1
#define CONVERT_BLOCKS(B) adjust_blocks ((SMB_BIG_UINT)(B), (SMB_BIG_UINT)fsd.f_fsize, (SMB_BIG_UINT)512)
	struct statfs fsd;


// #error STAT_STATFS3_OSF1
	if (statfs (path, &fsd, sizeof (struct statfs)) != 0)
		return -1;
#endif /* STAT_STATFS3_OSF1 */
	
#ifdef STAT_STATFS2_FS_DATA	/* Ultrix */
#define CONVERT_BLOCKS(B) adjust_blocks ((SMB_BIG_UINT)(B), (SMB_BIG_UINT)1024, (SMB_BIG_UINT)512)	
	struct fs_data fsd;
	
// #error STAT_STATFS2_FS_DATA
	if (statfs (path, &fsd) != 1)
		return -1;
	
	(*dsize) = CONVERT_BLOCKS (fsd.fd_req.btot);
	(*dfree) = CONVERT_BLOCKS (fsd.fd_req.bfreen);
#endif /* STAT_STATFS2_FS_DATA */
	
#ifdef STAT_STATFS2_BSIZE	/* 4.3BSD, SunOS 4, HP-UX, AIX */
#define CONVERT_BLOCKS(B) adjust_blocks ((SMB_BIG_UINT)(B), (SMB_BIG_UINT)fsd.f_bsize, (SMB_BIG_UINT)512)
	struct statfs fsd;
	
// #error STAT_STATFS2_FS_BSIZE
	if (statfs (path, &fsd) < 0)
		return -1;
	
#ifdef STATFS_TRUNCATES_BLOCK_COUNTS
	/* In SunOS 4.1.2, 4.1.3, and 4.1.3_U1, the block counts in the
	   struct statfs are truncated to 2GB.  These conditions detect that
	   truncation, presumably without botching the 4.1.1 case, in which
	   the values are not truncated.  The correct counts are stored in
	   undocumented spare fields.  */
	if (fsd.f_blocks == 0x1fffff && fsd.f_spare[0] > 0) {
		fsd.f_blocks = fsd.f_spare[0];
		fsd.f_bfree = fsd.f_spare[1];
		fsd.f_bavail = fsd.f_spare[2];
	}
#endif /* STATFS_TRUNCATES_BLOCK_COUNTS */
#endif /* STAT_STATFS2_BSIZE */
	

#ifdef STAT_STATFS2_FSIZE	/* 4.4BSD */
#define CONVERT_BLOCKS(B) adjust_blocks ((SMB_BIG_UINT)(B), (SMB_BIG_UINT)fsd.f_fsize, (SMB_BIG_UINT)512)
	
	struct statfs fsd;
	
// #error STAT_STATFS2_FSIZE
	if (statfs (path, &fsd) < 0)
		return -1;
#endif /* STAT_STATFS2_FSIZE */
	
#ifdef STAT_STATFS4		/* SVR3, Dynix, Irix, AIX */
# if _AIX || defined(_CRAY)
#  define CONVERT_BLOCKS(B) adjust_blocks ((SMB_BIG_UINT)(B), (SMB_BIG_UINT)fsd.f_bsize, (SMB_BIG_UINT)512)
#  ifdef _CRAY
#   define f_bavail f_bfree
#  endif
# else
#  define CONVERT_BLOCKS(B) ((SMB_BIG_UINT)B)
#  ifndef _SEQUENT_		/* _SEQUENT_ is DYNIX/ptx */
#   ifndef DOLPHIN		/* DOLPHIN 3.8.alfa/7.18 has f_bavail */
#    define f_bavail f_bfree
#   endif
#  endif
# endif
	
	struct statfs fsd;

// #error STAT_STATFS4
	if (statfs (path, &fsd, sizeof fsd, 0) < 0)
		return -1;
	/* Empirically, the block counts on most SVR3 and SVR3-derived
	   systems seem to always be in terms of 512-byte blocks,
	   no matter what value f_bsize has.  */

#endif /* STAT_STATFS4 */

#if defined(STAT_STATVFS) || defined(STAT_STATVFS64)		/* SVR4 */
# define CONVERT_BLOCKS(B) \
	adjust_blocks ((SMB_BIG_UINT)(B), fsd.f_frsize ? (SMB_BIG_UINT)fsd.f_frsize : (SMB_BIG_UINT)fsd.f_bsize, (SMB_BIG_UINT)512)

#ifdef STAT_STATVFS64
// #error STAT_STATVFS64
	struct statvfs64 fsd;
	if (statvfs64(path, &fsd) < 0) return -1;
#else
// #error STAT_STATVFS
	struct statvfs fsd;
	if (statvfs(path, &fsd) < 0) return -1;
#endif

	/* f_frsize isn't guaranteed to be supported.  */

#endif /* STAT_STATVFS */

#ifndef CONVERT_BLOCKS
#error no STAT_STATxxx defined - we have no dfree code!
	/* we don't have any dfree code! */
	return -1;
#else
#if !defined(STAT_STATFS2_FS_DATA)
	/* !Ultrix */
	(*dsize) = CONVERT_BLOCKS (fsd.f_blocks);
	(*dfree) = CONVERT_BLOCKS (fsd.f_bavail);
#endif /* not STAT_STATFS2_FS_DATA */
#endif

	return 0;
}

#ifdef AVM_FRITZBOX
/* Get the free and total space of the partition with path
 * plus all other partitions mounted below this partition
 *
 * results are returned in *dfree and *dsize, in 512 byte units
 */
int sys_avm_fsusage(const char *path, SMB_BIG_UINT *dfree, SMB_BIG_UINT *dsize)
{
	SMB_BIG_UINT free;
	SMB_BIG_UINT size;
	int ret;

	*dfree = *dsize = 0;

	FILE *fp = fopen("/proc/mounts", "r");
	if (fp) {
		char real[PATH_MAX];
		char buf[2048];
		if (0 != realpath(path , real)) {
			int real_len = strlen(real);
			while(fgets(buf, sizeof(buf), fp)) {
				char *part = buf;
				while(*part != ' ' && *part != '\0') part++;
				if (*part != ' ') continue;
				part++;
				char *p = part;
				while(*p != ' ' && *p != '\0') p++;
				if (*p != ' ') continue;
				*p = '\0';
				// check if part is sub of real
				int part_len = p - part;
				if (part_len <= real_len) continue;
				if (memcmp(real, part, real_len)) continue;
				if (part[real_len] != '/') continue;
				ret = sys_fsusage(part, &free, &size);
				if (0 == ret) {
					*dfree += free;
					*dsize += size;
				}
			}
		}
		fclose(fp);
	}

	ret = sys_fsusage(path, &free, &size);
	if (0 == ret) {
		*dfree += free;
		*dsize += size;
	}
	return ret;
}
#endif // AVM_FRITZBOX