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/*
* Copyright (C) 2000-2006 Erik Andersen <andersen@uclibc.org>
*
* Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
*/
#include <features.h>
#include <alloca.h>
#include <assert.h>
#include <errno.h>
#include <dirent.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>
#include <unistd.h>
#include <sys/param.h>
#include <sys/types.h>
#include <sys/syscall.h>
#include <bits/kernel_types.h>
#if defined __UCLIBC_HAS_LFS__ && defined __NR_getdents64
# ifndef offsetof
# define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
# endif
struct kernel_dirent64
{
uint64_t d_ino;
int64_t d_off;
unsigned short d_reclen;
unsigned char d_type;
char d_name[256];
};
# define __NR___syscall_getdents64 __NR_getdents64
static __inline__ _syscall3(int, __syscall_getdents64, int, fd, unsigned char *, dirp, size_t, count)
ssize_t __getdents64 (int fd, char *buf, size_t nbytes) attribute_hidden;
ssize_t __getdents64 (int fd, char *buf, size_t nbytes)
{
struct dirent64 *dp;
off64_t last_offset = -1;
ssize_t retval;
size_t red_nbytes;
struct kernel_dirent64 *skdp, *kdp;
const size_t size_diff = (offsetof (struct dirent64, d_name)
- offsetof (struct kernel_dirent64, d_name));
red_nbytes = MIN (nbytes - ((nbytes /
(offsetof (struct dirent64, d_name) + 14)) * size_diff),
nbytes - size_diff);
dp = (struct dirent64 *) buf;
skdp = kdp = alloca (red_nbytes);
retval = __syscall_getdents64(fd, (unsigned char *)kdp, red_nbytes);
if (retval == -1)
return -1;
while ((char *) kdp < (char *) skdp + retval) {
const size_t alignment = __alignof__ (struct dirent64);
/* Since kdp->d_reclen is already aligned for the kernel structure
this may compute a value that is bigger than necessary. */
size_t new_reclen = ((kdp->d_reclen + size_diff + alignment - 1)
& ~(alignment - 1));
if ((char *) dp + new_reclen > buf + nbytes) {
/* Our heuristic failed. We read too many entries. Reset
the stream. */
assert (last_offset != -1);
lseek64(fd, last_offset, SEEK_SET);
if ((char *) dp == buf) {
/* The buffer the user passed in is too small to hold even
one entry. */
__set_errno (EINVAL);
return -1;
}
break;
}
last_offset = kdp->d_off;
dp->d_ino = kdp->d_ino;
dp->d_off = kdp->d_off;
dp->d_reclen = new_reclen;
dp->d_type = kdp->d_type;
memcpy (dp->d_name, kdp->d_name,
kdp->d_reclen - offsetof (struct kernel_dirent64, d_name));
dp = (struct dirent64 *) ((char *) dp + new_reclen);
kdp = (struct kernel_dirent64 *) (((char *) kdp) + kdp->d_reclen);
}
return (char *) dp - buf;
}
#if __WORDSIZE == 64
/* since getdents doesnt give us d_type but getdents64 does, try and
* use getdents64 as much as possible */
attribute_hidden strong_alias(__getdents64,__getdents)
#endif
#endif
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