URLRequest fuzzer.

net/base/fuzzed_data_provider.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef NET_BASE_FUZZED_DATA_PROVIDER_H
+#define NET_BASE_FUZZED_DATA_PROVIDER_H
+
+#include <stdint.h>
+
+#include "base/macros.h"
+#include "base/strings/string_piece.h"
+
+namespace net {
+
+// Utility class to break up fuzzer input for multiple consumers.  Whenever run
+// on the same input, provides the same output, as long as its methods are
+// called in the same order, with the same arguments.
+class FuzzedDataProvider {
+ public:
+  // |data| is an array of length |size| that the FuzzedDataProvider slices to
+  // provide more granular access to. |data| must outlive the
+  // FuzzedDataProvider.
+  FuzzedDataProvider(const uint8_t* data, size_t size);
+  ~FuzzedDataProvider();
+
+  // Tries to copy the first |bytes| remaining bytes from the input data to
+  // |dest|. If fewer than that many bytes of data remain, writes all the
+  // data that's left. Returns number of bytes written, which may be 0.
+  size_t ConsumeBytes(char* dest, size_t bytes);
+
+  // Returns a value with the specified number of bits of data. Returns 0 if
+  // there's no input data left. Pulls data from the end of the array.  Despit
+  // its name, always consumes bits in multiples of 8, just throws away anything
+  // left over, to try and be more friendly to the mutations the fuzzer applies.
+  // |num_bits| must be less than 32.
+  uint32_t ConsumeBits(size_t num_bits);
+
+  // Same as ConsumeBits(1), but returns a bool.
+  bool ConsumeBool();
+
+  // Creates a value in the specified range, consuming only as much data is
+  // needed.  Value may not uniformly distributed in that range.
+  uint32_t ConsumeValueInRange(uint32_t min, uint32_t max);
+
+ private:
+  base::StringPiece remaining_data_;
+
+  DISALLOW_COPY_AND_ASSIGN(FuzzedDataProvider);
+};
+
+}  // namespace net
+
+#endif  // NET_BASE_FUZZED_DATA_PROVIDER_H