oss-fuzz/projects/libxml2/fuzzer_temp_file.h

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// Copyright 2018 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Adapter utility from fuzzer input to a temporary file, for fuzzing APIs that
// require a file instead of an input buffer.
#ifndef FUZZER_TEMP_FILE_H_
#define FUZZER_TEMP_FILE_H_
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
// Pure-C interface for creating and cleaning up temporary files.
static char* fuzzer_get_tmpfile(const uint8_t* data, size_t size) {
char* filename_buffer = strdup("/tmp/generate_temporary_file.XXXXXX");
if (!filename_buffer) {
perror("Failed to allocate file name buffer.");
abort();
}
const int file_descriptor = mkstemp(filename_buffer);
if (file_descriptor < 0) {
perror("Failed to make temporary file.");
abort();
}
FILE* file = fdopen(file_descriptor, "wb");
if (!file) {
perror("Failed to open file descriptor.");
close(file_descriptor);
abort();
}
const size_t bytes_written = fwrite(data, sizeof(uint8_t), size, file);
if (bytes_written < size) {
close(file_descriptor);
fprintf(stderr, "Failed to write all bytes to file (%zu out of %zu)",
bytes_written, size);
abort();
}
fclose(file);
return filename_buffer;
}
static void fuzzer_release_tmpfile(char* filename) {
if (unlink(filename) != 0) {
perror("WARNING: Failed to delete temporary file.");
}
free(filename);
}
// C++ RAII object for creating temporary files.
#ifdef __cplusplus
class FuzzerTemporaryFile {
public:
FuzzerTemporaryFile(const uint8_t* data, size_t size)
: filename_(fuzzer_get_tmpfile(data, size)) {}
~FuzzerTemporaryFile() { fuzzer_release_tmpfile(filename_); }
const char* filename() const { return filename_; }
private:
char* filename_;
};
#endif
#endif // FUZZER_TEMP_FILE_H_