| // Copyright 2013 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 "chrome/browser/net/dns_probe_runner.h" |
| |
| #include <utility> |
| |
| #include "base/bind.h" |
| #include "base/optional.h" |
| #include "mojo/public/cpp/bindings/message.h" |
| #include "net/base/address_list.h" |
| #include "net/base/host_port_pair.h" |
| #include "net/base/net_errors.h" |
| #include "services/network/public/mojom/network_context.mojom.h" |
| |
| namespace chrome_browser_net { |
| |
| const char DnsProbeRunner::kKnownGoodHostname[] = "google.com"; |
| |
| namespace { |
| |
| DnsProbeRunner::Result EvaluateResponse( |
| int net_error, |
| const base::Optional<net::AddressList>& resolved_addresses) { |
| switch (net_error) { |
| case net::OK: |
| break; |
| |
| case net::ERR_FAILED: |
| return DnsProbeRunner::UNKNOWN; |
| |
| // ERR_NAME_NOT_RESOLVED maps to NXDOMAIN, which means the server is working |
| // but returned a wrong answer. |
| case net::ERR_NAME_NOT_RESOLVED: |
| return DnsProbeRunner::INCORRECT; |
| |
| // These results mean we heard *something* from the DNS server, but it was |
| // unsuccessful (SERVFAIL) or malformed. |
| case net::ERR_DNS_MALFORMED_RESPONSE: |
| case net::ERR_DNS_SERVER_REQUIRES_TCP: // Shouldn't happen; DnsTransaction |
| // will retry with TCP. |
| case net::ERR_DNS_SERVER_FAILED: |
| case net::ERR_DNS_SORT_ERROR: // Can only happen if the server responds. |
| return DnsProbeRunner::FAILING; |
| |
| // Any other error means we never reached the DNS server in the first place. |
| case net::ERR_DNS_TIMED_OUT: |
| default: |
| // Something else happened, probably at a network level. |
| return DnsProbeRunner::UNREACHABLE; |
| } |
| |
| if (!resolved_addresses) { |
| // If net_error is OK, resolved_addresses should be set. The binding is not |
| // closed here since it will be closed by the caller anyway. |
| mojo::ReportBadMessage("resolved_addresses not set when net_error=OK"); |
| return DnsProbeRunner::UNKNOWN; |
| } else if (resolved_addresses.value().empty()) { |
| return DnsProbeRunner::INCORRECT; |
| } else { |
| return DnsProbeRunner::CORRECT; |
| } |
| } |
| |
| } // namespace |
| |
| DnsProbeRunner::DnsProbeRunner( |
| net::DnsConfigOverrides dns_config_overrides, |
| const NetworkContextGetter& network_context_getter) |
| : binding_(this), |
| dns_config_overrides_(dns_config_overrides), |
| network_context_getter_(network_context_getter), |
| result_(UNKNOWN) { |
| CreateHostResolver(); |
| } |
| |
| DnsProbeRunner::~DnsProbeRunner() { |
| DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_); |
| } |
| |
| void DnsProbeRunner::RunProbe(base::OnceClosure callback) { |
| DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_); |
| DCHECK(!callback.is_null()); |
| DCHECK(host_resolver_); |
| DCHECK(callback_.is_null()); |
| DCHECK(!binding_); |
| |
| network::mojom::ResolveHostClientPtr client_ptr; |
| binding_.Bind(mojo::MakeRequest(&client_ptr)); |
| binding_.set_connection_error_handler(base::BindOnce( |
| &DnsProbeRunner::OnMojoConnectionError, base::Unretained(this))); |
| |
| network::mojom::ResolveHostParametersPtr parameters = |
| network::mojom::ResolveHostParameters::New(); |
| parameters->dns_query_type = net::DnsQueryType::A; |
| parameters->source = net::HostResolverSource::DNS; |
| parameters->allow_cached_response = false; |
| |
| host_resolver_->ResolveHost(net::HostPortPair(kKnownGoodHostname, 80), |
| std::move(parameters), std::move(client_ptr)); |
| |
| callback_ = std::move(callback); |
| } |
| |
| bool DnsProbeRunner::IsRunning() const { |
| DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_); |
| return !callback_.is_null(); |
| } |
| |
| void DnsProbeRunner::OnComplete( |
| int32_t result, |
| const base::Optional<net::AddressList>& resolved_addresses) { |
| DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_); |
| DCHECK(!callback_.is_null()); |
| |
| result_ = EvaluateResponse(result, resolved_addresses); |
| binding_.Close(); |
| |
| // ResolveHost will call OnComplete asynchronously, so callback_ can be |
| // invoked directly here. Clear callback in case it starts a new probe |
| // immediately. |
| std::move(callback_).Run(); |
| } |
| |
| void DnsProbeRunner::CreateHostResolver() { |
| host_resolver_.reset(); |
| network_context_getter_.Run()->CreateHostResolver( |
| dns_config_overrides_, mojo::MakeRequest(&host_resolver_)); |
| } |
| |
| void DnsProbeRunner::OnMojoConnectionError() { |
| DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_); |
| CreateHostResolver(); |
| OnComplete(net::ERR_FAILED, base::nullopt); |
| } |
| |
| } // namespace chrome_browser_net |