// 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.

#include "net/nqe/network_quality_estimator_util.h"

#include <memory>

#include "base/bind.h"
#include "base/check_op.h"
#include "base/notreached.h"
#include "net/base/host_port_pair.h"
#include "net/base/ip_address.h"
#include "net/base/ip_endpoint.h"
#include "net/base/net_errors.h"
#include "net/dns/host_resolver.h"
#include "net/dns/host_resolver_source.h"
#include "net/log/net_log_with_source.h"
#include "net/url_request/url_request.h"
#include "net/url_request/url_request_context.h"

namespace net {

namespace nqe {

namespace {

bool IsPrivateHost(HostResolver* host_resolver,
                   const HostPortPair& host_port_pair,
                   const NetworkIsolationKey& network_isolation_key) {
  // Try resolving |host_port_pair.host()| synchronously.
  HostResolver::ResolveHostParameters parameters;
  parameters.source = HostResolverSource::LOCAL_ONLY;
  std::unique_ptr<HostResolver::ResolveHostRequest> request =
      host_resolver->CreateRequest(host_port_pair, network_isolation_key,
                                   NetLogWithSource(), parameters);

  int rv = request->Start(base::BindOnce([](int error) { NOTREACHED(); }));
  DCHECK_NE(rv, ERR_IO_PENDING);

  if (rv == OK && request->GetAddressResults() &&
      !request->GetAddressResults().value().empty()) {
    // Checking only the first address should be sufficient.
    IPEndPoint ip_endpoint = request->GetAddressResults().value().front();
    IPAddress ip_address = ip_endpoint.address();
    if (!ip_address.IsPubliclyRoutable())
      return true;
  }

  return false;
}

}  // namespace

namespace internal {

bool IsRequestForPrivateHost(const URLRequest& request) {
  // Using the request's NetworkIsolationKey isn't necessary for privacy
  // reasons, but is needed to maximize the chances of a cache hit.
  return IsPrivateHost(request.context()->host_resolver(),
                       HostPortPair::FromURL(request.url()),
                       request.isolation_info().network_isolation_key());
}

bool IsPrivateHostForTesting(HostResolver* host_resolver,
                             const HostPortPair& host_port_pair,
                             const NetworkIsolationKey& network_isolation_key) {
  return IsPrivateHost(host_resolver, host_port_pair, network_isolation_key);
}

}  // namespace internal

}  // namespace nqe

}  // namespace net