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/*-
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek.
*
* 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.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 <errno.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include "private/ErrnoRestorer.h"
class ScopedSignalBlocker {
public:
ScopedSignalBlocker() {
sigset_t set;
sigfillset(&set);
sigprocmask(SIG_BLOCK, &set, &old_set_);
}
~ScopedSignalBlocker() {
sigprocmask(SIG_SETMASK, &old_set_, NULL);
}
private:
sigset_t old_set_;
};
static FILE* __tmpfile_dir(const char* tmp_dir) {
char* path = NULL;
if (asprintf(&path, "%s/tmp.XXXXXXXXXX", tmp_dir) == -1) {
return NULL;
}
int fd;
{
ScopedSignalBlocker ssb;
fd = mkstemp(path);
if (fd == -1) {
free(path);
return NULL;
}
// Unlink the file now so that it's removed when closed.
unlink(path);
free(path);
// Can we still use the file now it's unlinked?
// File systems without hard link support won't have the usual Unix semantics.
struct stat sb;
int rc = fstat(fd, &sb);
if (rc == -1) {
ErrnoRestorer errno_restorer;
close(fd);
return NULL;
}
}
// Turn the file descriptor into a FILE*.
FILE* fp = fdopen(fd, "w+");
if (fp != NULL) {
return fp;
}
// Failure. Clean up. We already unlinked, so we just need to close.
ErrnoRestorer errno_restorer;
close(fd);
return NULL;
}
FILE* tmpfile() {
// TODO: get this app's temporary directory from the framework ("/data/data/app/cache").
// $EXTERNAL_STORAGE turns out not to be very useful because it doesn't support hard links.
// This means we can't do the usual trick of calling unlink before handing the file back.
FILE* fp = __tmpfile_dir("/data/local/tmp");
if (fp == NULL) {
// P_tmpdir is "/tmp/", but POSIX explicitly says that tmpdir(3) should try P_tmpdir before
// giving up. This is potentially useful for bionic on the host anyway.
fp = __tmpfile_dir(P_tmpdir);
}
return fp;
}
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