toolkit/components/resistfingerprinting/nsUserCharacteristics.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "nsUserCharacteristics.h"
   7
   8 #include "nsID.h"
   9 #include "nsIUUIDGenerator.h"
  10
  11 #include "mozilla/Logging.h"
  12 #include "mozilla/glean/GleanPings.h"
  13 #include "mozilla/glean/GleanMetrics.h"
  14
  15 static mozilla::LazyLogModule gUserCharacteristicsLog("UserCharacteristics");
  16
  17 // The current schema of the data. Anytime you add a metric, or change how a
  18 // metric is set, this variable should be incremented. It'll be a lot. It's
  19 // okay. We're going to need it to know (including during development) what is
  20 // the source of the data we are looking at.
  21 const int kSubmissionSchema = 0;
  22
  23 /* static */
  24 void nsUserCharacteristics::MaybeSubmitPing() {
  25   MOZ_LOG(gUserCharacteristicsLog, LogLevel::Debug, ("In MaybeSubmitPing()"));
  26
  27   /**
  28    * There are two preferences at play here:
  29    *  - Last Version Sent - preference containing the last version sent by the
  30    * user to Mozilla
  31    *  - Current Version - preference containing the version Mozilla would like
  32    * the user to send
  33    *
  34    * A point of complexity arises in that these two values _may_ be changed
  35    * by the user, even though neither is intended to be.
  36    *
  37    * When Current Version > Last Version Sent, we intend for the user to submit
  38    * a new ping, which will include the schema version. Then update Last Version
  39    * Sent = Current Version.
  40    *
  41    */
  42   const auto* const kLastVersionPref =
  43       "toolkit.telemetry.user_characteristics_ping.last_version_sent";
  44   const auto* const kCurrentVersionPref =
  45       "toolkit.telemetry.user_characteristics_ping.current_version";
  46
  47   auto lastSubmissionVersion = Preferences::GetInt(kLastVersionPref, 0);
  48   auto currentVersion = Preferences::GetInt(kCurrentVersionPref, 0);
  49
  50   MOZ_ASSERT(currentVersion == -1 || lastSubmissionVersion <= currentVersion,
  51              "lastSubmissionVersion is somehow greater than currentVersion "
  52              "- did you edit prefs improperly?");
  53
  54   if (lastSubmissionVersion < 0) {
  55     // This is a way for users to opt out of this ping specifically.
  56     MOZ_LOG(gUserCharacteristicsLog, LogLevel::Debug,
  57             ("Returning, User Opt-out"));
  58     return;
  59   }
  60   if (currentVersion == 0) {
  61     // Do nothing. We do not want any pings.
  62     MOZ_LOG(gUserCharacteristicsLog, LogLevel::Debug,
  63             ("Returning, currentVersion == 0"));
  64     return;
  65   }
  66   if (currentVersion == -1) {
  67     // currentVersion = -1 is a development value to force a ping submission
  68     MOZ_LOG(gUserCharacteristicsLog, LogLevel::Debug,
  69             ("Force-Submitting Ping"));
  70     if (NS_SUCCEEDED(PopulateData())) {
  71       SubmitPing();
  72     }
  73     return;
  74   }
  75   if (lastSubmissionVersion > currentVersion) {
  76     // This is an unexpected scneario that indicates something is wrong. We
  77     // asserted against it (in debug, above) We will try to sanity-correct
  78     // ourselves by setting it to the current version.
  79     Preferences::SetInt(kLastVersionPref, currentVersion);
  80     MOZ_LOG(gUserCharacteristicsLog, LogLevel::Warning,
  81             ("Returning, lastSubmissionVersion > currentVersion"));
  82     return;
  83   }
  84   if (lastSubmissionVersion == currentVersion) {
  85     // We are okay, we've already submitted the most recent ping
  86     MOZ_LOG(gUserCharacteristicsLog, LogLevel::Warning,
  87             ("Returning, lastSubmissionVersion == currentVersion"));
  88     return;
  89   }
  90   if (lastSubmissionVersion < currentVersion) {
  91     if (NS_SUCCEEDED(PopulateData())) {
  92       if (NS_SUCCEEDED(SubmitPing())) {
  93         Preferences::SetInt(kLastVersionPref, currentVersion);
  94       }
  95     }
  96   } else {
  97     MOZ_ASSERT_UNREACHABLE("Should never reach here");
  98   }
  99 }
 100
 101 const auto* const kUUIDPref =
 102     "toolkit.telemetry.user_characteristics_ping.uuid";
 103
 104 /* static */
 105 nsresult nsUserCharacteristics::PopulateData() {
 106   MOZ_LOG(gUserCharacteristicsLog, LogLevel::Warning, ("Populating Data"));
 107   mozilla::glean::characteristics::submission_schema.Set(kSubmissionSchema);
 108
 109   nsAutoCString uuidString;
 110   nsresult rv = Preferences::GetCString(kUUIDPref, uuidString);
 111   if (NS_FAILED(rv) || uuidString.Length() == 0) {
 112     nsCOMPtr<nsIUUIDGenerator> uuidgen =
 113         do_GetService("@mozilla.org/uuid-generator;1", &rv);
 114     NS_ENSURE_SUCCESS(rv, rv);
 115
 116     nsIDToCString id(nsID::GenerateUUID());
 117     uuidString = id.get();
 118     Preferences::SetCString(kUUIDPref, uuidString);
 119   }
 120   mozilla::glean::characteristics::client_identifier.Set(uuidString);
 121
 122   return NS_OK;
 123 }
 124
 125 /* static */
 126 nsresult nsUserCharacteristics::SubmitPing() {
 127   MOZ_LOG(gUserCharacteristicsLog, LogLevel::Warning, ("Submitting Ping"));
 128   mozilla::glean_pings::UserCharacteristics.Submit();
 129
 130   return NS_OK;
 131 }