libc
/* $Id$ */
/* Copyright (c) 2005-2020 Pierre Pronchery <khorben@defora.org> */
/* This file is part of DeforaOS System libc */
/* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. 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
* HOLDER 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 "sys/stat.h"
#include "fcntl.h"
#include "unistd.h"
#include "stddef.h"
#include "stdlib.h"
#include "string.h"
#include "limits.h"
#include "errno.h"
#include "syscalls.h"
#include "dirent.h"
/* types */
struct _DIR
{
int fd;
char buf[PAGESIZE];
size_t len;
};
/* functions */
/* closedir */
int closedir(DIR * dir)
{
if(dir == NULL)
{
errno = EINVAL;
return -1;
}
if(close(dir->fd) != 0)
return -1;
free(dir);
return 0;
}
/* dirfd */
int dirfd(DIR * dir)
{
if(dir == NULL)
{
errno = EINVAL;
return -1;
}
return dir->fd;
}
/* opendir */
DIR * opendir(char const * name)
{
#ifdef O_DIRECTORY
const int flags = O_DIRECTORY | O_RDONLY;
#else
const int flags = O_RDONLY;
struct stat st;
#endif
DIR * dir;
int fd;
if((fd = open(name, flags)) < 0)
return NULL;
if(fcntl(fd, F_SETFD, FD_CLOEXEC) != 0)
{
close(fd);
return NULL;
}
#ifndef O_DIRECTORY
if(fstat(fd, &st) != 0)
{
close(fd);
return NULL;
}
if(!S_ISDIR(st.st_mode))
{
close(fd);
errno = ENOTDIR;
return NULL;
}
#endif
if((dir = malloc(sizeof(*dir))) == NULL)
{
close(fd);
return NULL;
}
dir->fd = fd;
dir->len = 0;
return dir;
}
/* readdir */
#if defined(SYS_getdents) || defined(SYS_getdirentries)
int getdents(int fd, char * buf, size_t nbuf);
# ifdef SYS_getdirentries
int getdirentries(int fd, char * buf, size_t nbuf, char * basep);
# define getdents(fd, buf, size) getdirentries(fd, buf, size, NULL)
# endif
struct dirent * readdir(DIR * dir)
{
static struct dirent de;
ssize_t slen;
size_t len;
const size_t off = offsetof(struct dirent, d_name);
for(;;)
{
if(dir->len == 0)
{
if((slen = getdents(dir->fd, dir->buf, sizeof(
dir->buf))) < 0)
return NULL;
len = slen;
dir->len = len;
}
memcpy(&de, dir->buf, off);
len = de.d_reclen;
if(len > sizeof(de) || len > dir->len || len <= off)
{
dir->len = 0;
return NULL;
}
memcpy(de.d_name, &dir->buf[off], len - off);
dir->len -= len;
memmove(dir->buf, &dir->buf[len], dir->len);
if(de.d_ino != 0)
break;
}
return &de;
}
#elif !defined(SYS_readdir)
# warning Unsupported platform: readdir() is missing
struct dirent * readdir(DIR * dir)
{
errno = ENOSYS;
return NULL;
}
#endif
/* rewinddir */
void rewinddir(DIR * dir)
{
if(lseek(dir->fd, 0, SEEK_SET) != 0)
{
close(dir->fd);
dir->fd = -1;
dir->len = 0;
}
dir->len = 0;
}