NQE: Exclude network observations from private networks

net/nqe/network_quality_estimator_util.h

+// Copyright 2017 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_NQE_NETWORK_QUALITY_ESTIMATOR_UTIL_H_
+#define NET_NQE_NETWORK_QUALITY_ESTIMATOR_UTIL_H_
+
+#include "net/base/net_export.h"
+
+namespace net {
+
+class HostPortPair;
+class HostResolver;
+class NetLogWithSource;
+
+namespace nqe {
+
+namespace internal {
+
+// Returns true if the host contained in |host_port_pair| is a host in a
+// private Internet as defined by RFC 1918. IsPrivateHost() makes the best

[bengr, 2017/06/13 20:35:36]

Add to the comment that these are hosts with IP addresses that match:

     10.0.0.0        -   10.255.255.255  (10/8 prefix)
     172.16.0.0      -   172.31.255.255  (172.16/12 prefix)
     192.168.0.0     -   192.168.255.255 (192.168/16 prefix)

[mmenke, 2017/06/14 18:23:31]

This is actually not what the method is doing.  IPAddress::IsReserved checks a
lot more reserved ranges than those reserved for local networks.  I don't think
we have a check for just these 3 prefixes in net/, though
dns/address_sorter_posix.cc may have similar logic somewhere.

[tbansal1, 2017/06/16 00:57:42]

Right. I have added few more comments to the method.

+// effort estimate including trying to resolve the host in the
+// |host_port_pair|. The method is synchronous.
+NET_EXPORT_PRIVATE bool IsPrivateHost(HostResolver* host_resolver,

[bengr, 2017/06/13 20:35:36]

This seems like something more generic than nqe. Perhaps put it in some more
general purpose net util file?

[tbansal1, 2017/06/16 00:57:42]

We can think about moving it to a more common place if there is some other
consumer. Right now, it looks very NQE specific. It also might have few false
positives (IPs that are not private may be marked as such).

+                                      const HostPortPair& host_port_pair,
+                                      const NetLogWithSource& net_log);
+
+}  // namespace internal
+
+}  // namespace nqe
+
+}  // namespace net
+
+#endif  // NET_NQE_NETWORK_QUALITY_ESTIMATOR_UTIL_H_