701bec2af3
The old scandir implementation didn't take into account the varying size of directory entries, and didn't correctly clean up on its error exits. Bug: 7339844 Change-Id: Ib40e3564709752241a3119a496cbb2192e3f9abe
150 lines
3.7 KiB
C++
150 lines
3.7 KiB
C++
/*
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* Copyright (C) 2008 The Android Open Source Project
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <dirent.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <sys/stat.h>
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#include <sys/types.h>
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#include <unistd.h>
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#include "private/ErrnoRestorer.h"
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#include "private/ScopedPthreadMutexLocker.h"
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struct DIR {
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int fd_;
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size_t available_bytes_;
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dirent* next_;
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pthread_mutex_t mutex_;
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dirent buff_[15];
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};
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static DIR* __allocate_DIR(int fd) {
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DIR* d = reinterpret_cast<DIR*>(malloc(sizeof(DIR)));
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if (d == NULL) {
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return NULL;
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}
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d->fd_ = fd;
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d->available_bytes_ = 0;
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d->next_ = NULL;
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pthread_mutex_init(&d->mutex_, NULL);
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return d;
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}
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int dirfd(DIR* dirp) {
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return dirp->fd_;
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}
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DIR* fdopendir(int fd) {
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// Is 'fd' actually a directory?
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struct stat sb;
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if (fstat(fd, &sb) == -1) {
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return NULL;
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}
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if (!S_ISDIR(sb.st_mode)) {
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errno = ENOTDIR;
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return NULL;
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}
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return __allocate_DIR(fd);
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}
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DIR* opendir(const char* path) {
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int fd = open(path, O_RDONLY | O_DIRECTORY);
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return (fd != -1) ? __allocate_DIR(fd) : NULL;
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}
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static bool __fill_DIR(DIR* d) {
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int rc = TEMP_FAILURE_RETRY(getdents(d->fd_, d->buff_, sizeof(d->buff_)));
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if (rc <= 0) {
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return false;
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}
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d->available_bytes_ = rc;
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d->next_ = d->buff_;
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return true;
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}
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static dirent* __readdir_locked(DIR* d) {
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if (d->available_bytes_ == 0 && !__fill_DIR(d)) {
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return NULL;
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}
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dirent* entry = d->next_;
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d->next_ = reinterpret_cast<dirent*>(reinterpret_cast<char*>(entry) + entry->d_reclen);
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d->available_bytes_ -= entry->d_reclen;
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return entry;
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}
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dirent* readdir(DIR* d) {
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ScopedPthreadMutexLocker locker(&d->mutex_);
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return __readdir_locked(d);
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}
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int readdir_r(DIR* d, dirent* entry, dirent** result) {
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ErrnoRestorer errno_restorer;
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*result = NULL;
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errno = 0;
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ScopedPthreadMutexLocker locker(&d->mutex_);
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dirent* next = __readdir_locked(d);
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if (errno != 0 && next == NULL) {
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return errno;
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}
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if (next != NULL) {
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memcpy(entry, next, next->d_reclen);
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*result = entry;
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}
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return 0;
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}
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int closedir(DIR* d) {
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if (d == NULL) {
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errno = EINVAL;
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return -1;
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}
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int fd = d->fd_;
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pthread_mutex_destroy(&d->mutex_);
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free(d);
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return close(fd);
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}
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void rewinddir(DIR* d) {
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ScopedPthreadMutexLocker locker(&d->mutex_);
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lseek(d->fd_, 0, SEEK_SET);
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d->available_bytes_ = 0;
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}
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int alphasort(const dirent** a, const dirent** b) {
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return strcoll((*a)->d_name, (*b)->d_name);
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}
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