commit c43f6bbd8ab12ee2bf0c82913c63e77b191e00e8
author Jae Hoon Kim <kimjae@chromium.org> Wed Jul 03 12:56:52 2019 -0700
committer Jae Hoon Kim <kimjae@chromium.org> Thu Jul 18 17:32:37 2019 -0700
tree 93cd56ed7ceb3ce6916296fd706657242178b0ac
parent a441743c13237847fc96d5721faa8721806d8363

update_engine: Query dlcservice to avoid stale DLC module IDs

Within |UpdateAttempter|, the possibility of using stale DLC module IDs
existed. This should never happen. The fix is to go through |DlcService|
to recieve the list of fresh and current DLC module IDs. This change now
will handle both interactive and non-interactive update cases.

This is only for updates.

BUG=chromium:978525
TEST=FEATURES="test" emerge-${BOARD} update_engine

Change-Id: Iffa75f60f367b2a110c559654fa3df9c48c714b1

dlcservice_chromeos.cc

diff --git a/dlcservice_chromeos.cc b/dlcservice_chromeos.cc
index b7dee36..ad5806a 100644
--- a/dlcservice_chromeos.cc
+++ b/dlcservice_chromeos.cc
@@ -35,6 +35,8 @@
 bool DlcServiceChromeOS::GetInstalled(vector<string>* dlc_module_ids) {
   if (!dlc_module_ids)
     return false;
+  dlc_module_ids->clear();
+
   org::chromium::DlcServiceInterfaceProxy dlcservice_proxy(
       DBusConnection::Get()->GetDBus());
 

dlcservice_chromeos.h

diff --git a/dlcservice_chromeos.h b/dlcservice_chromeos.h
index 8d103c1..73442e6 100644
--- a/dlcservice_chromeos.h
+++ b/dlcservice_chromeos.h
@@ -33,6 +33,10 @@
   ~DlcServiceChromeOS() = default;
 
   // BootControlInterface overrides.
+  // Will clear the |dlc_module_ids|, passed to be modified. Clearing by
+  // default has the added benefit of avoiding indeterminate behavior in the
+  // case that |dlc_module_ids| wasn't empty to begin which would lead to
+  // possible duplicates and cases when error was not checked it's still safe.
   bool GetInstalled(std::vector<std::string>* dlc_module_ids) override;
 
  private:

update_attempter.cc

diff --git a/update_attempter.cc b/update_attempter.cc
index 9573c43..b06807d 100644
--- a/update_attempter.cc
+++ b/update_attempter.cc
@@ -425,7 +425,14 @@
     // target channel.
     omaha_request_params_->UpdateDownloadChannel();
   }
-  // Set the DLC module ID list.
+
+  // Set the |dlc_module_ids_| only for an update. This is required to get the
+  // currently installed DLC(s).
+  if (!is_install_ &&
+      !system_state_->dlcservice()->GetInstalled(&dlc_module_ids_)) {
+    LOG(INFO) << "Failed to retrieve DLC module IDs from dlcservice. Check the "
+                 "state of dlcservice, will not update DLC modules.";
+  }
   omaha_request_params_->set_dlc_module_ids(dlc_module_ids_);
   omaha_request_params_->set_is_install(is_install_);
 
@@ -838,7 +845,6 @@
   }
 
   bool interactive = !(flags & UpdateAttemptFlags::kFlagNonInteractive);
-  dlc_module_ids_.clear();
   is_install_ = false;
 
   LOG(INFO) << "Forced update check requested.";
@@ -903,9 +909,9 @@
   if (IsAnyUpdateSourceAllowed()) {
     forced_omaha_url_ = omaha_url;
   }
-  if (omaha_url == kScheduledAUTestURLRequest) {
-    forced_omaha_url_ = constants::kOmahaDefaultAUTestURL;
-  } else if (omaha_url == kAUTestURLRequest) {
+
+  if (omaha_url == kScheduledAUTestURLRequest ||
+      omaha_url == kAUTestURLRequest) {
     forced_omaha_url_ = constants::kOmahaDefaultAUTestURL;
   }