Display DNS probe results.

chrome/browser/net/dns_probe_service.cc

 // Copyright (c) 2012 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_service.h"
 
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/string_number_conversions.h"
 #include "chrome/browser/net/dns_probe_job.h"
 #include "chrome/common/net/net_error_info.h"
 #include "net/base/ip_endpoint.h"
 #include "net/base/net_util.h"
 #include "net/dns/dns_client.h"
 #include "net/dns/dns_config_service.h"
 #include "net/dns/dns_protocol.h"
 
 using base::FieldTrialList;
 using base::StringToInt;
-using chrome_common_net::DnsProbeResult;
+using chrome_common_net::DnsProbeStatus;
 using net::DnsClient;
 using net::DnsConfig;
 using net::IPAddressNumber;
 using net::IPEndPoint;
 using net::ParseIPLiteralToNumber;
 using net::NetworkChangeNotifier;
 
 namespace chrome_browser_net {
 
 namespace {
@@ skipping 38 matching lines @@
 
 // The maximum number of nameservers counted in histograms.
 const int kNameserverCountMax = 10;
 
 }  // namespace
 
 DnsProbeService::DnsProbeService()
     : system_result_(DnsProbeJob::SERVERS_UNKNOWN),
       public_result_(DnsProbeJob::SERVERS_UNKNOWN),
       state_(STATE_NO_RESULTS),
-      result_(chrome_common_net::DNS_PROBE_UNKNOWN),
+      result_(chrome_common_net::DNS_PROBE_FINISHED_UNKNOWN),
       dns_attempts_(GetAttemptsFromFieldTrial()) {
   NetworkChangeNotifier::AddIPAddressObserver(this);
 }
 
 DnsProbeService::~DnsProbeService() {
   NetworkChangeNotifier::RemoveIPAddressObserver(this);
 }
 
 void DnsProbeService::ProbeDns(const DnsProbeService::CallbackType& callback) {
   callbacks_.push_back(callback);
@@ skipping 30 matching lines @@
 
 void DnsProbeService::OnIPAddressChanged() {
   if (state_ == STATE_RESULTS_CACHED)
     ExpireResults();
 }
 
 void DnsProbeService::ExpireResults() {
   DCHECK_EQ(STATE_RESULTS_CACHED, state_);
 
   state_ = STATE_NO_RESULTS;
-  result_ = chrome_common_net::DNS_PROBE_UNKNOWN;
+  result_ = chrome_common_net::DNS_PROBE_FINISHED_UNKNOWN;

[mmenke, 2013/04/10 16:56:58]

Should this actually be DNS_PROBE_MAX?  Seems like it would provide some
additional DCHECKS protecting against treating the value set here as a real
result.

[Deprecated (see juliatuttle), 2013/04/10 23:42:32]

Done.

 }
 
 void DnsProbeService::StartProbes() {
   DCHECK_NE(STATE_PROBE_RUNNING, state_);
   DCHECK(!system_job_.get());
   DCHECK(!public_job_.get());
 
   DnsProbeJob::CallbackType job_callback =
       base::Bind(&DnsProbeService::OnProbeJobComplete,
                  base::Unretained(this));
 
   // TODO(ttuttle): Do we want to keep explicit flags for "job done"?
   //                Or maybe DnsProbeJob should have a "finished" flag?
   system_result_ = DnsProbeJob::SERVERS_UNKNOWN;
   public_result_ = DnsProbeJob::SERVERS_UNKNOWN;
 
   system_job_ = CreateSystemProbeJob(job_callback);
   public_job_ = CreatePublicProbeJob(job_callback);
 
   // If we can't create one or both jobs, fail the probe immediately.
   if (!system_job_.get() || !public_job_.get()) {
     system_job_.reset();
     public_job_.reset();
     state_ = STATE_RESULTS_CACHED;
     // TODO(ttuttle): Should this be BAD_CONFIG?  Currently I think it only
     // happens when the system DnsConfig has no servers.
-    result_ = chrome_common_net::DNS_PROBE_UNKNOWN;
+    result_ = chrome_common_net::DNS_PROBE_FINISHED_UNKNOWN;
     CallCallbacks();
     return;
   }
 
   state_ = STATE_PROBE_RUNNING;
   probe_start_time_ = base::Time::Now();
 }
 
 void DnsProbeService::OnProbesComplete() {
   DCHECK_EQ(STATE_PROBE_RUNNING, state_);
 
   state_ = STATE_RESULTS_CACHED;
   result_ = EvaluateResults();
 
   HistogramProbes();
 
   CallCallbacks();
 }
 
 void DnsProbeService::HistogramProbes() const {
-  const DnsProbeResult kMaxResult = chrome_common_net::DNS_PROBE_MAX;
+  const DnsProbeStatus kMinFinishedStatus =
+      chrome_common_net::DNS_PROBE_FINISHED_UNKNOWN;
+  const DnsProbeStatus kMaxStatus = chrome_common_net::DNS_PROBE_MAX;
 
   DCHECK_EQ(STATE_RESULTS_CACHED, state_);
-  DCHECK_NE(kMaxResult, result_);
+  DCHECK_GE(result_, kMinFinishedStatus);
+  DCHECK_NE(result_, kMaxStatus);

[mmenke, 2013/04/10 16:56:58]

DCHECK_LT?

[Deprecated (see juliatuttle), 2013/04/10 23:42:32]

Done.

 
   base::TimeDelta elapsed = base::Time::Now() - probe_start_time_;
 
-  UMA_HISTOGRAM_ENUMERATION("DnsProbe.Probe.Result", result_, kMaxResult);
-  UMA_HISTOGRAM_MEDIUM_TIMES("DnsProbe.Probe.Elapsed", elapsed);
+  UMA_HISTOGRAM_ENUMERATION("DnsProbe.Status", result_, kMaxStatus);
+  UMA_HISTOGRAM_MEDIUM_TIMES("DnsProbe.Elapsed", elapsed);
 
   if (NetworkChangeNotifier::IsOffline()) {
-    UMA_HISTOGRAM_ENUMERATION("DnsProbe.Probe.NcnOffline.Result",
-                              result_, kMaxResult);
-    UMA_HISTOGRAM_MEDIUM_TIMES("DnsProbe.Probe.NcnOffline.Elapsed", elapsed);
+    UMA_HISTOGRAM_ENUMERATION("DnsProbe.Status_NcnOffline",
+                              result_, kMaxStatus);
+    UMA_HISTOGRAM_MEDIUM_TIMES("DnsProbe.Elapsed_NcnOffline", elapsed);
   } else {
-    UMA_HISTOGRAM_ENUMERATION("DnsProbe.Probe.NcnOnline.Result",
-                              result_, kMaxResult);
-    UMA_HISTOGRAM_MEDIUM_TIMES("DnsProbe.Probe.NcnOnline.Elapsed", elapsed);
+    UMA_HISTOGRAM_ENUMERATION("DnsProbe.Status_NcnOnline",
+                              result_, kMaxStatus);
+    UMA_HISTOGRAM_MEDIUM_TIMES("DnsProbe.Elapsed_NcnOnline", elapsed);
   }
 
   switch (result_) {
-  case chrome_common_net::DNS_PROBE_UNKNOWN:
-    UMA_HISTOGRAM_MEDIUM_TIMES("DnsProbe.Probe.ResultUnknown.Elapsed",
+  case chrome_common_net::DNS_PROBE_FINISHED_UNKNOWN:
+    UMA_HISTOGRAM_MEDIUM_TIMES("DnsProbe.Elapsed_Unknown",
                                elapsed);
     break;
-  case chrome_common_net::DNS_PROBE_NO_INTERNET:
-    UMA_HISTOGRAM_MEDIUM_TIMES("DnsProbe.Probe.ResultNoInternet.Elapsed",
+  case chrome_common_net::DNS_PROBE_FINISHED_NO_INTERNET:
+    UMA_HISTOGRAM_MEDIUM_TIMES("DnsProbe.Elapsed_NoInternet",
                                elapsed);
     break;
-  case chrome_common_net::DNS_PROBE_BAD_CONFIG:
-    UMA_HISTOGRAM_MEDIUM_TIMES("DnsProbe.Probe.ResultBadConfig.Elapsed",
-                               elapsed);
-
-    // Histogram some extra data to see why BAD_CONFIG is happening.
-    UMA_HISTOGRAM_ENUMERATION(
-        "DnsProbe.Probe.ResultBadConfig.SystemJobResult",
-        system_result_,
-        DnsProbeJob::MAX_RESULT);
-    UMA_HISTOGRAM_CUSTOM_COUNTS(
-        "DnsProbe.Probe.ResultBadConfig.SystemNameserverCount",
-        system_nameserver_count_,
-        0, kNameserverCountMax, kNameserverCountMax + 1);
-    UMA_HISTOGRAM_BOOLEAN(
-        "DnsProbe.Probe.ResultBadConfig.SystemIsLocalhost",
-        system_is_localhost_);
-    break;
-  case chrome_common_net::DNS_PROBE_NXDOMAIN:
-    UMA_HISTOGRAM_MEDIUM_TIMES("DnsProbe.Probe.ResultNxdomain.Elapsed",
+  case chrome_common_net::DNS_PROBE_FINISHED_BAD_CONFIG:
+    UMA_HISTOGRAM_MEDIUM_TIMES("DnsProbe.Elapsed_BadConfig",
                                elapsed);
     break;
+  case chrome_common_net::DNS_PROBE_FINISHED_NXDOMAIN:
+    UMA_HISTOGRAM_MEDIUM_TIMES("DnsProbe.Elapsed_Nxdomain",
+                               elapsed);
+    break;
+
+  // These aren't actually results.
+  case chrome_common_net::DNS_PROBE_POSSIBLE:
+  case chrome_common_net::DNS_PROBE_NOT_RUN:
+  case chrome_common_net::DNS_PROBE_STARTED:
   case chrome_common_net::DNS_PROBE_MAX:

[mmenke, 2013/04/10 16:56:58]

Maybe just a "default:"?

[Deprecated (see juliatuttle), 2013/04/10 23:42:32]

I didn't use default: to preserve the warning if we add another DNS probe
result.

     NOTREACHED();
     break;
   }
 }
 
-DnsProbeResult DnsProbeService::EvaluateResults() const {
+DnsProbeStatus DnsProbeService::EvaluateResults() const {
   DCHECK_NE(DnsProbeJob::SERVERS_UNKNOWN, system_result_);
   DCHECK_NE(DnsProbeJob::SERVERS_UNKNOWN, public_result_);
 
   // If the system DNS is working, assume the domain doesn't exist.
   if (system_result_ == DnsProbeJob::SERVERS_CORRECT)
-    return chrome_common_net::DNS_PROBE_NXDOMAIN;
+    return chrome_common_net::DNS_PROBE_FINISHED_NXDOMAIN;
 
   // If the system DNS is not working but another public server is, assume the
   // DNS config is bad (or perhaps the DNS servers are down or broken).
   if (public_result_ == DnsProbeJob::SERVERS_CORRECT)
-    return chrome_common_net::DNS_PROBE_BAD_CONFIG;
+    return chrome_common_net::DNS_PROBE_FINISHED_BAD_CONFIG;
 
   // If the system DNS is not working and another public server is unreachable,
   // assume the internet connection is down (note that system DNS may be a
   // router on the LAN, so it may be reachable but returning errors.)
   if (public_result_ == DnsProbeJob::SERVERS_UNREACHABLE)
-    return chrome_common_net::DNS_PROBE_NO_INTERNET;
+    return chrome_common_net::DNS_PROBE_FINISHED_NO_INTERNET;
 
   // Otherwise: the system DNS is not working and another public server is
   // responding but with errors or incorrect results.  This is an awkward case;
   // an invasive captive portal or a restrictive firewall may be intercepting
   // or rewriting DNS traffic, or the public server may itself be failing or
   // down.
-  return chrome_common_net::DNS_PROBE_UNKNOWN;
+  return chrome_common_net::DNS_PROBE_FINISHED_UNKNOWN;
 }
 
 void DnsProbeService::CallCallbacks() {
   DCHECK_EQ(STATE_RESULTS_CACHED, state_);
   DCHECK(!callbacks_.empty());
 
   std::vector<CallbackType> callbacks = callbacks_;
   callbacks_.clear();
 
   for (std::vector<CallbackType>::const_iterator i = callbacks.begin();
@@ skipping 36 matching lines @@
 
 void DnsProbeService::GetSystemDnsConfig(DnsConfig* config) {
   NetworkChangeNotifier::GetDnsConfig(config);
 
   // DNS probes don't need or want the suffix search list populated
   config->search.clear();
 
   if (dns_attempts_ != kAttemptsUseDefault)
     config->attempts = dns_attempts_;
 
-  // Take notes in case the config turns out to be bad, so we can histogram
-  // some useful data.
-  system_nameserver_count_ = config->nameservers.size();
-  system_is_localhost_ = (system_nameserver_count_ == 1)
-                         && IsLocalhost(config->nameservers[0].address());
-
   // Disable port randomization.
   config->randomize_ports = false;
 }
 
 void DnsProbeService::GetPublicDnsConfig(DnsConfig* config) {
   *config = DnsConfig();
 
   config->nameservers.push_back(MakeDnsEndPoint(kPublicDnsPrimary));
   config->nameservers.push_back(MakeDnsEndPoint(kPublicDnsSecondary));
 
   if (dns_attempts_ != kAttemptsUseDefault)
     config->attempts = dns_attempts_;
 
   // Disable port randomization.
   config->randomize_ports = false;
 }
 
 bool DnsProbeService::ResultsExpired() {
   const base::TimeDelta kMaxResultAge =
       base::TimeDelta::FromMilliseconds(kMaxResultAgeMs);
   return base::Time::Now() - probe_start_time_ > kMaxResultAge;
 }
 
 } // namespace chrome_browser_net