Add a fuzzer for GzipSourceStream

net/filter/fuzzed_source_stream.cc

Index: net/filter/fuzzed_source_stream.cc
diff --git a/net/filter/fuzzed_source_stream.cc b/net/filter/fuzzed_source_stream.cc
new file mode 100644
index 0000000000000000000000000000000000000000..626675d9d650e8d73ae98485da782795cc6d76b9
--- /dev/null
+++ b/net/filter/fuzzed_source_stream.cc
@@ -0,0 +1,88 @@
+// 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.
+
+#include "net/filter/fuzzed_source_stream.h"
+
+#include <algorithm>
+
+#include "base/test/fuzzed_data_provider.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "net/base/io_buffer.h"
+#include "net/base/net_errors.h"
+
+namespace net {
+
+namespace {
+
+// Common net error codes that can be returned by a SourceStream.
+const Error kReadErrors[] = {OK, ERR_FAILED, ERR_CONTENT_DECODING_FAILED};
+
+}  // namespace
+
+FuzzedSourceStream::FuzzedSourceStream(base::FuzzedDataProvider* data_provider)
+    : SourceStream(SourceStream::TYPE_NONE),
+      data_provider_(data_provider),
+      read_pending_(false),
+      end_returned_(false) {}
+
+FuzzedSourceStream::~FuzzedSourceStream() {
+  DCHECK(!read_pending_);
+}
+
+int FuzzedSourceStream::Read(IOBuffer* buf,
+                             int buf_len,
+                             const CompletionCallback& callback) {
+  DCHECK(!read_pending_);
+  DCHECK(!end_returned_);
+  DCHECK_LE(0, buf_len);
+
+  bool sync = data_provider_->ConsumeBool();
+  int result = data_provider_->ConsumeUint32InRange(0, buf_len);
+  std::string data = data_provider_->ConsumeBytes(result);
+  result = data.size();
+
+  if (result <= 0)
+    result = data_provider_->PickValueInArray(kReadErrors);
+
+  if (sync) {
+    if (result > 0) {
+      std::copy(data.data(), data.data() + result, buf->data());
+    } else {
+      end_returned_ = true;
+    }
+    return result;
+  }
+
+  scoped_refptr<IOBuffer> pending_read_buf = buf;
+
+  read_pending_ = true;
+  // |this| is owned by the caller so use base::Unretained is safe.
+  base::ThreadTaskRunnerHandle::Get()->PostTask(
+      FROM_HERE,
+      base::Bind(&FuzzedSourceStream::OnReadComplete, base::Unretained(this),
+                 callback, data, pending_read_buf, result));
+  return ERR_IO_PENDING;
+}
+
+std::string FuzzedSourceStream::Description() const {
+  return "";
+}
+
+void FuzzedSourceStream::OnReadComplete(const CompletionCallback& callback,
+                                        const std::string& fuzzed_data,
+                                        scoped_refptr<IOBuffer> read_buf,
+                                        int result) {
+  DCHECK(read_pending_);
+
+  if (result > 0) {
+    std::copy(fuzzed_data.data(), fuzzed_data.data() + result,
+              read_buf->data());
+  } else {
+    end_returned_ = true;
+  }
+  read_pending_ = false;
+  callback.Run(result);
+}
+
+}  // namespace net