/*
* Copyright (C) 2008 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <pathconf.h>
#include <sys/vfs.h>
#include <sys/limits.h>
#include <linux/ext2_fs.h>
#include <linux/ext3_fs.h>
#include <errno.h>
/* these may not be defined yet by our headers */
#ifndef _POSIX_VDISABLE
#define _POSIX_VDISABLE -1
#endif
#ifndef _POSIX_SYNC_IO
#define _POSIX_SYNC_IO -1
#endif
#ifndef _POSIX_PRIO_IO
#define _POSIX_PRIO_IO -1
#endif
#ifndef _POSIX_ASYNC_IO
#define _POSIX_ASYNC_IO -1
#endif
static long
__filesizebits( struct statfs* s )
{
#define EOL_MAGIC 0x0000U
/* list of known 64-bit aware filesystems */
static const uint32_t known64[] = {
EXT2_SUPER_MAGIC,
UFS_MAGIC,
REISERFS_SUPER_MAGIC,
XFS_SUPER_MAGIC,
SMB_SUPER_MAGIC,
UDF_SUPER_MAGIC,
JFS_SUPER_MAGIC,
NTFS_SB_MAGIC,
VXFS_SUPER_MAGIC,
EOL_MAGIC
};
int nn = 0;
for (;;) {
if ( known64[nn] == EOL_MAGIC )
return 32;
if ( known64[nn] == s->f_type )
return 64;
}
}
static long
__link_max( struct statfs* s )
{
/* constant values were taken from official kernel headers.
* I don't think this justified bringing in <linux/minix_fs.h> et al
* into our cleaned-up kernel three
*/
static const struct { uint32_t type; int max; } knownMax[] =
{
{ EXT2_SUPER_MAGIC, EXT2_LINK_MAX },
{ EXT3_SUPER_MAGIC, EXT3_LINK_MAX },
{ MINIX_SUPER_MAGIC, 250 },
{ MINIX2_SUPER_MAGIC, 65530 },
{ REISERFS_SUPER_MAGIC, 0xffff - 1000 },
{ UFS_MAGIC, 32000 },
{ EOL_MAGIC, 0 }
};
int nn = 0;
for (;;) {
if ( knownMax[nn].type == EOL_MAGIC )
return LINK_MAX;
if ( knownMax[nn].type == s->f_type )
return knownMax[nn].max;
}
return LINK_MAX;
}
static long
__2_symlinks( struct statfs* s )
{
/* list of know filesystems that don't support symlinks */
static const uint32_t knownNoSymlinks[] = {
ADFS_SUPER_MAGIC, BFS_MAGIC, CRAMFS_MAGIC,
EFS_SUPER_MAGIC, MSDOS_SUPER_MAGIC, NTFS_SB_MAGIC,
QNX4_SUPER_MAGIC,
EOL_MAGIC
};
int nn = 0;
for (;;) {
if (knownNoSymlinks[nn] == 0)
return 1;
if (knownNoSymlinks[nn] == s->f_type)
return 0;
}
}
static long
__name_max( struct statfs* s )
{
return s->f_namelen;
}
long
pathconf(const char *path, int name)
{
struct statfs buf;
int ret = statfs( path, &buf );
if (ret < 0)
return -1;
switch (name) {
case _PC_FILESIZEBITS:
return __filesizebits(&buf);
case _PC_LINK_MAX:
return __link_max(&buf);
case _PC_MAX_CANON:
return MAX_CANON;
case _PC_MAX_INPUT:
return MAX_INPUT;
case _PC_NAME_MAX:
return __name_max(&buf);
case _PC_PATH_MAX:
return PATH_MAX;
case _PC_PIPE_BUF:
return PIPE_BUF;
case _PC_2_SYMLINKS:
return __2_symlinks(&buf);
#if 0 /* don't know what to do there, the specs are really weird */
case _PC_ALLOC_SIZE_MIN:
case _PC_REC_INCR_XFER_SIZE:
case _PC_REC_MAX_XFER_SIZE:
case _PC_REC_MIN_XFER_SIZE:
case _PC_REC_XFER_ALIGN:
#endif
case _PC_SYMLINK_MAX:
return -1; /* no limit */
case _PC_CHOWN_RESTRICTED:
return _POSIX_CHOWN_RESTRICTED;
case _PC_NO_TRUNC:
return _POSIX_NO_TRUNC;
case _PC_VDISABLE:
return _POSIX_VDISABLE;
case _PC_ASYNC_IO:
return _POSIX_ASYNC_IO;
case _PC_PRIO_IO:
return _POSIX_PRIO_IO;
case _PC_SYNC_IO:
return _POSIX_SYNC_IO;
default:
errno = EINVAL;
return -1;
}
}
long fpathconf(int fildes, int name)
{
struct statfs buf;
int ret = fstatfs(fildes, &buf);
if (ret < 0)
return -1;
switch (name) {
case _PC_FILESIZEBITS:
return __filesizebits(&buf);
case _PC_LINK_MAX:
return __link_max(&buf);
case _PC_MAX_CANON:
return MAX_CANON;
case _PC_MAX_INPUT:
return MAX_INPUT;
case _PC_NAME_MAX:
return __name_max(&buf);
case _PC_PATH_MAX:
return PATH_MAX;
case _PC_PIPE_BUF:
return PIPE_BUF;
case _PC_2_SYMLINKS:
return __2_symlinks(&buf);
#if 0 /* don't know what to do there, the specs are really weird */
case _PC_ALLOC_SIZE_MIN:
case _PC_REC_INCR_XFER_SIZE:
case _PC_REC_MAX_XFER_SIZE:
case _PC_REC_MIN_XFER_SIZE:
case _PC_REC_XFER_ALIGN:
#endif
case _PC_SYMLINK_MAX:
return -1; /* no limit */
case _PC_CHOWN_RESTRICTED:
return _POSIX_CHOWN_RESTRICTED;
case _PC_NO_TRUNC:
return _POSIX_NO_TRUNC;
case _PC_VDISABLE:
return _POSIX_VDISABLE;
case _PC_ASYNC_IO:
return _POSIX_ASYNC_IO;
case _PC_PRIO_IO:
return _POSIX_PRIO_IO;
case _PC_SYNC_IO:
return _POSIX_SYNC_IO;
default:
errno = EINVAL;
return -1;
}
}