1 files changed, 148 insertions, 0 deletions
diff --git a/tests/fuzzer/fuzzer_temp_file.h b/tests/fuzzer/fuzzer_temp_file.h
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+++ b/tests/fuzzer/fuzzer_temp_file.h
@@ -0,0 +1,148 @@
+/*
+ * Copyright 2020 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.
+ */
+
+#ifndef LIBGAV1_TESTS_FUZZER_FUZZER_TEMP_FILE_H_
+#define LIBGAV1_TESTS_FUZZER_FUZZER_TEMP_FILE_H_
+
+// Adapter utility from fuzzer input to a temporary file, for fuzzing APIs that
+// require a file instead of an input buffer.
+
+#include <limits.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_with_suffix(const uint8_t* data, size_t size,
+                                            const char* suffix) {
+  if (suffix == NULL) {  // NOLINT (this could be a C compilation unit)
+    suffix = "";
+  }
+  const size_t suffix_len = strlen(suffix);
+  if (suffix_len > INT_MAX) {  // mkstemps takes int for suffixlen param
+    perror("Suffix too long");
+    abort();
+  }
+
+#ifdef __ANDROID__
+  const char* leading_temp_path =
+      "/data/local/tmp/generate_temporary_file.XXXXXX";
+#else
+  const char* leading_temp_path = "/tmp/generate_temporary_file.XXXXXX";
+#endif
+  const size_t buffer_sz = strlen(leading_temp_path) + suffix_len + 1;
+  char* filename_buffer =
+      (char*)malloc(buffer_sz);  // NOLINT (this could be a C compilation unit)
+  if (!filename_buffer) {
+    perror("Failed to allocate file name buffer.");
+    abort();
+  }
+
+  if (snprintf(filename_buffer, buffer_sz, "%s%s", leading_temp_path, suffix) >=
+      buffer_sz) {
+    perror("File name buffer too short.");
+    abort();
+  }
+
+  const int file_descriptor = mkstemps(filename_buffer, suffix_len);
+  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 char* fuzzer_get_tmpfile(
+    const uint8_t* data,
+    size_t size) {  // NOLINT (people include this .inc file directly)
+  return fuzzer_get_tmpfile_with_suffix(data, size, NULL);  // NOLINT
+}
+
+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)
+      : original_filename_(fuzzer_get_tmpfile(data, size)) {
+    filename_ = strdup(original_filename_);
+    if (!filename_) {
+      perror("Failed to allocate file name copy.");
+      abort();
+    }
+  }
+
+  FuzzerTemporaryFile(const uint8_t* data, size_t size, const char* suffix)
+      : original_filename_(fuzzer_get_tmpfile_with_suffix(data, size, suffix)) {
+    filename_ = strdup(original_filename_);
+    if (!filename_) {
+      perror("Failed to allocate file name copy.");
+      abort();
+    }
+  }
+
+  ~FuzzerTemporaryFile() {
+    free(filename_);
+    fuzzer_release_tmpfile(original_filename_);
+  }
+
+  FuzzerTemporaryFile(const FuzzerTemporaryFile& other) = delete;
+  FuzzerTemporaryFile operator=(const FuzzerTemporaryFile& other) = delete;
+
+  FuzzerTemporaryFile(const FuzzerTemporaryFile&& other) = delete;
+  FuzzerTemporaryFile operator=(const FuzzerTemporaryFile&& other) = delete;
+
+  const char* filename() const { return filename_; }
+
+  // Returns a mutable pointer to the file name. Should be used sparingly, only
+  // in case the fuzzed API demands it or when making a mutable copy is
+  // inconvenient (e.g., in auto-generated code).
+  char* mutable_filename() const { return filename_; }
+
+ private:
+  char* original_filename_;
+
+  // A mutable copy of the original filename, returned by the accessor. This
+  // guarantees that the original filename can always be used to release the
+  // temporary path.
+  char* filename_;
+};
+#endif  // __cplusplus
+#endif  // LIBGAV1_TESTS_FUZZER_FUZZER_TEMP_FILE_H_