/*
   Unix SMB/CIFS implementation.
   VFS API's statvfs abstraction
   Copyright (C) Alexander Bokovoy			2005
   Copyright (C) Steve French				2005
   Copyright (C) James Peach				2006

   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 3 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, see <http://www.gnu.org/licenses/>.
*/

#include "replace.h"
#include "system/filesys.h"
#include "libcli/smb/smb_constants.h"
#include "statvfs.h"

#if defined(DARWINOS)
#include <sys/attr.h>

static int darwin_fs_capabilities(const char * path)
{
	int caps = 0;
	vol_capabilities_attr_t *vcaps;
	struct attrlist	attrlist;
	char attrbuf[sizeof(u_int32_t) + sizeof(vol_capabilities_attr_t)];

#define FORMAT_CAP(vinfo, cap) \
	( ((vinfo)->valid[VOL_CAPABILITIES_FORMAT] & (cap)) && \
	   ((vinfo)->capabilities[VOL_CAPABILITIES_FORMAT] & (cap)) )

#define INTERFACE_CAP(vinfo, cap) \
	( ((vinfo)->valid[VOL_CAPABILITIES_INTERFACES] & (cap)) && \
	   ((vinfo)->capabilities[VOL_CAPABILITIES_INTERFACES] & (cap)) )

	attrlist = (struct attrlist) {
		.bitmapcount = ATTR_BIT_MAP_COUNT,
		.volattr = ATTR_VOL_CAPABILITIES,
	};

	if (getattrlist(path, &attrlist, attrbuf, sizeof(attrbuf), 0) != 0) {
		DEBUG(0, ("getattrlist for %s capabilities failed: %s\n",
			    path, strerror(errno)));
		/* Return no capabilities on failure. */
		return 0;
	}

	vcaps =
	    (vol_capabilities_attr_t *)(attrbuf + sizeof(u_int32_t));

	if (FORMAT_CAP(vcaps, VOL_CAP_FMT_SPARSE_FILES)) {
		caps |= FILE_SUPPORTS_SPARSE_FILES;
	}

	if (FORMAT_CAP(vcaps, VOL_CAP_FMT_CASE_SENSITIVE)) {
		caps |= FILE_CASE_SENSITIVE_SEARCH;
	}

	if (FORMAT_CAP(vcaps, VOL_CAP_FMT_CASE_PRESERVING)) {
		caps |= FILE_CASE_PRESERVED_NAMES;
	}

	if (INTERFACE_CAP(vcaps, VOL_CAP_INT_EXTENDED_SECURITY)) {
		caps |= FILE_PERSISTENT_ACLS;
	}

	return caps;
}
#endif /* DARWINOS */

#if defined(BSD_STYLE_STATVFS)

static void bsd_init_statvfs(const struct statvfs *src,
			     struct vfs_statvfs_struct *dst)
{
	dst->OptimalTransferSize = src->f_iosize;
	dst->BlockSize = src->f_bsize;
	dst->TotalBlocks = src->f_blocks;
	dst->BlocksAvail = src->f_bfree;
	dst->UserBlocksAvail = src->f_bavail;
	dst->TotalFileNodes = src->f_files;
	dst->FreeFileNodes = src->f_ffree;
	dst->FsIdentifier = (((uint64_t)src->f_fsid.val[0] << 32) &
			     0xffffffff00000000LL) |
			    (uint64_t)src->f_fsid.val[1];
#ifdef DARWINOS
	dst->FsCapabilities = darwin_fs_capabilities(src->f_mntonname);
#else
	/* Try to extrapolate some of the fs flags into the
	 * capabilities
	 */
	dst->FsCapabilities = FILE_CASE_SENSITIVE_SEARCH |
			      FILE_CASE_PRESERVED_NAMES;
#ifdef MNT_ACLS
	if (src->f_flags & MNT_ACLS) {
		dst->FsCapabilities |= FILE_PERSISTENT_ACLS;
	}
#endif
#endif
	if (src->f_flags & MNT_QUOTA) {
		dst->FsCapabilities |= FILE_VOLUME_QUOTAS;
	}
	if (src->f_flags & MNT_RDONLY) {
		dst->FsCapabilities |= FILE_READ_ONLY_VOLUME;
	}
}

static int bsd_statvfs(const char *path, struct vfs_statvfs_struct *statbuf)
{
	struct statfs sbuf;
	int ret;

	ret = statfs(path, &sbuf);
	if (ret != 0) {
		return ret;
	}

	bsd_init_statvfs(&sbuf, statbuf);

	return 0;
}

static int bsd_fstatvfs(int fd, struct vfs_statvfs_struct *statbuf)
{
	struct statfs sbuf;
	int ret;

	ret = fstatfs(fd, &sbuf);
	if (ret != 0) {
		return ret;
	}

	bsd_init_statvfs(&sbuf, statbuf);

	return 0;
}

#elif defined(STAT_STATVFS) && defined(HAVE_FSID_INT)

static void posix_init_statvfs(const struct statvfs *src,
			       struct vfs_statvfs_struct *dst)
{
	/* statvfs bsize is not the statfs bsize, the naming is terrible,
	 * see bug 11810 */
	dst->OptimalTransferSize = src->f_bsize;
	dst->BlockSize = src->f_frsize;
	dst->TotalBlocks = src->f_blocks;
	dst->BlocksAvail = src->f_bfree;
	dst->UserBlocksAvail = src->f_bavail;
	dst->TotalFileNodes = src->f_files;
	dst->FreeFileNodes = src->f_ffree;
	dst->FsIdentifier = src->f_fsid;
	/* Try to extrapolate some of the fs flags into the
	 * capabilities
	 */
	dst->FsCapabilities = FILE_CASE_SENSITIVE_SEARCH |
			      FILE_CASE_PRESERVED_NAMES;
#ifdef ST_QUOTA
	if (src->f_flag & ST_QUOTA) {
		dst->FsCapabilities |= FILE_VOLUME_QUOTAS;
	}
#endif
	if (src->f_flag & ST_RDONLY) {
		dst->FsCapabilities |= FILE_READ_ONLY_VOLUME;
	}

#if defined(HAVE_FALLOC_FL_PUNCH_HOLE) && defined(HAVE_LSEEK_HOLE_DATA)
	/*
	 * Only flag sparse file support if ZERO_DATA can be used to
	 * deallocate blocks, and SEEK_HOLE / SEEK_DATA can be used
	 * to provide QUERY_ALLOCATED_RANGES information.
	 */
	dst->FsCapabilities |= FILE_SUPPORTS_SPARSE_FILES;
#endif
}

static int posix_statvfs(const char *path, struct vfs_statvfs_struct *statbuf)
{
	struct statvfs statvfs_buf;
	int ret;

	ret = statvfs(path, &statvfs_buf);

	if (ret != 0) {
		return ret;
	}

	posix_init_statvfs(&statvfs_buf, statbuf);

	return 0;
}

static int posix_fstatvfs(int fd, struct vfs_statvfs_struct *statbuf)
{
	struct statvfs statvfs_buf;
	int ret;

	ret = fstatvfs(fd, &statvfs_buf);

	if (ret != 0) {
		return ret;
	}

	posix_init_statvfs(&statvfs_buf, statbuf);

	return 0;
}

#endif

/*
 sys_statvfs() is an abstraction layer over system-dependent statvfs()/statfs()
 for particular POSIX systems. Due to controversy of what is considered more important
 between LSB and FreeBSD/POSIX.1 (IEEE Std 1003.1-2001) we need to abstract the interface
 so that particular OS would use its preferred interface.
*/
int sys_statvfs(const char *path, struct vfs_statvfs_struct *statbuf)
{
#if defined(BSD_STYLE_STATVFS)
	return bsd_statvfs(path, statbuf);
#elif defined(STAT_STATVFS) && defined(HAVE_FSID_INT)
	return posix_statvfs(path, statbuf);
#else
	/* BB change this to return invalid level */
#ifdef EOPNOTSUPP
	return EOPNOTSUPP;
#else
	return -1;
#endif /* EOPNOTSUPP */
#endif /* LINUX */

}

int sys_fstatvfs(int fd, struct vfs_statvfs_struct *statbuf)
{
#if defined(BSD_STYLE_STATVFS)
	return bsd_fstatvfs(fd, statbuf);
#elif defined(STAT_STATVFS) && defined(HAVE_FSID_INT)
	return posix_fstatvfs(fd, statbuf);
#else
	/* BB change this to return invalid level */
#ifdef EOPNOTSUPP
	return EOPNOTSUPP;
#else
	return -1;
#endif /* EOPNOTSUPP */
#endif /* LINUX */
}

/*
 * Return the number of TOSIZE-byte blocks used by BLOCKS
 * FROMSIZE-byte blocks, rounding away from zero.
 */
static uint64_t adjust_blocks(uint64_t blocks, uint64_t fromsize)
{
	if (fromsize == 512) {
		return blocks;
	}

	if (fromsize > 512) {
		return blocks * (fromsize / 512);
	}

	if (fromsize == 0) {
		fromsize = 512;
	}

	return (blocks + 1) / (512 / fromsize);
}

void statvfs2fsusage(const struct vfs_statvfs_struct *statbuf,
		     uint64_t *dfree,
		     uint64_t *dsize)
{
	*dfree = adjust_blocks(statbuf->UserBlocksAvail, statbuf->BlockSize);
	*dsize = adjust_blocks(statbuf->TotalBlocks, statbuf->BlockSize);
}