platform_bionic/libc/bionic/opendir.c
Elliott Hughes a89864a20b Move non-upstream code into the libc/bionic directory.
I'll need at least one more pass, because there's some upstream code
lurking in libc/bionic, but this is still a step in the right direction.

Change-Id: I55927315972da8327ae01c5240ed587db17e8462
2012-10-01 17:35:49 -07:00

273 lines
6.4 KiB
C

/*
* 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 <unistd.h>
#include <dirent.h>
#include <memory.h>
#include <string.h>
#include <fcntl.h>
#include <stdlib.h>
#include <pthread.h>
#include <errno.h>
struct DIR
{
int _DIR_fd;
size_t _DIR_avail;
struct dirent* _DIR_next;
pthread_mutex_t _DIR_lock;
struct dirent _DIR_buff[15];
};
int dirfd(DIR* dirp)
{
return dirp->_DIR_fd;
}
DIR* opendir( const char* dirpath )
{
DIR* dir = malloc(sizeof(DIR));
if (!dir)
goto Exit;
dir->_DIR_fd = open(dirpath, O_RDONLY|O_DIRECTORY);
if (dir->_DIR_fd < 0)
{
free(dir);
dir = NULL;
}
else
{
dir->_DIR_avail = 0;
dir->_DIR_next = NULL;
pthread_mutex_init( &dir->_DIR_lock, NULL );
}
Exit:
return dir;
}
DIR* fdopendir(int fd)
{
DIR* dir = malloc(sizeof(DIR));
if (!dir)
return 0;
dir->_DIR_fd = fd;
dir->_DIR_avail = 0;
dir->_DIR_next = NULL;
pthread_mutex_init( &dir->_DIR_lock, NULL );
return dir;
}
static struct dirent*
_readdir_unlocked(DIR* dir)
{
struct dirent* entry;
#ifndef NDEBUG
unsigned reclen;
#endif
if ( !dir->_DIR_avail )
{
int rc;
for (;;) {
rc = getdents( dir->_DIR_fd, dir->_DIR_buff, sizeof(dir->_DIR_buff));
if (rc >= 0 || errno != EINTR)
break;
}
if (rc <= 0)
return NULL;
dir->_DIR_avail = rc;
dir->_DIR_next = dir->_DIR_buff;
}
entry = dir->_DIR_next;
/* perform some sanity checks here */
if (((long)(void*)entry & 3) != 0)
return NULL;
#ifndef NDEBUG
// paranoid testing of the interface with the kernel getdents64 system call
reclen = offsetof(struct dirent, d_name) + strlen(entry->d_name) + 1;
if ( reclen > sizeof(*entry) || reclen <= offsetof(struct dirent, d_name) )
goto Bad;
if ( (char*)entry + reclen > (char*)dir->_DIR_buff + sizeof(dir->_DIR_buff) )
goto Bad;
if ( !memchr( entry->d_name, 0, reclen - offsetof(struct dirent, d_name)) )
goto Bad;
#endif
dir->_DIR_next = (struct dirent*)((char*)entry + entry->d_reclen);
dir->_DIR_avail -= entry->d_reclen;
return entry;
Bad:
errno = EINVAL;
return NULL;
}
struct dirent*
readdir(DIR * dir)
{
struct dirent *entry = NULL;
pthread_mutex_lock( &dir->_DIR_lock );
entry = _readdir_unlocked(dir);
pthread_mutex_unlock( &dir->_DIR_lock );
return entry;
}
int readdir_r(DIR* dir, struct dirent *entry, struct dirent **result)
{
struct dirent* ent;
int save_errno = errno;
int retval;
*result = NULL;
errno = 0;
pthread_mutex_lock( &dir->_DIR_lock );
ent = _readdir_unlocked(dir);
retval = errno;
if (ent == NULL) {
if (!retval) {
errno = save_errno;
}
} else {
if (!retval) {
errno = save_errno;
*result = entry;
memcpy( entry, ent, ent->d_reclen );
}
}
pthread_mutex_unlock( &dir->_DIR_lock );
return retval;
}
int closedir(DIR *dir)
{
int rc;
rc = close(dir->_DIR_fd);
dir->_DIR_fd = -1;
pthread_mutex_destroy( &dir->_DIR_lock );
free(dir);
return rc;
}
void rewinddir(DIR *dir)
{
pthread_mutex_lock( &dir->_DIR_lock );
lseek( dir->_DIR_fd, 0, SEEK_SET );
dir->_DIR_avail = 0;
pthread_mutex_unlock( &dir->_DIR_lock );
}
int alphasort(const void *a, const void *b)
{
struct dirent **d1, **d2;
d1 = (struct dirent **) a;
d2 = (struct dirent **) b;
return strcmp((*d1)->d_name, (*d2)->d_name);
}
int scandir(const char *dir, struct dirent ***namelist,
int(*filter)(const struct dirent *),
int(*compar)(const struct dirent **, const struct dirent **))
{
DIR *d;
int n_elem = 0;
struct dirent *this_de, *de;
struct dirent **de_list = NULL;
int de_list_size = 0;
d = opendir(dir);
if (d == NULL) {
return -1;
}
while ((this_de = readdir(d)) != NULL) {
if (filter && (*filter)(this_de) == 0) {
continue;
}
if (n_elem == 0) {
de_list_size = 4;
de_list = (struct dirent **)
malloc(sizeof(struct dirent *)*de_list_size);
if (de_list == NULL) {
return -1;
}
}
else if (n_elem == de_list_size) {
struct dirent **de_list_new;
de_list_size += 10;
de_list_new = (struct dirent **)
realloc(de_list, sizeof(struct dirent *)*de_list_size);
if (de_list_new == NULL) {
free(de_list);
return -1;
}
de_list = de_list_new;
}
de = (struct dirent *) malloc(sizeof(struct dirent));
*de = *this_de;
de_list[n_elem++] = de;
}
closedir(d);
if (n_elem && compar) {
qsort(de_list, n_elem, sizeof(struct dirent *),
(int (*)(const void *, const void *)) compar);
}
*namelist = de_list;
return n_elem;
}