fix: Add a UpdateDownloadCancel state to the mender-update's state ma…

…chine To make sure we always cancel the update download in case of an error. We need to be able to handle HTTPS/network/... errors as well as artifact parsing errors (incl. checksum mismatches,...). Instead of adding `download_client->Cancel()` calls to many places and risking missing some more, we introduce a new state the UpdateDownload state transitions into on failure and then things continue to the `download_error` state that handles the related state scripts, etc. Ticket: MEN-7810 Changelog: Fix download failure to always do a proper cancellation and cleanup of internal HTTP stuctures to avoid breaking future HTTP requests. Fixes `bad_version` error. Signed-off-by: Vratislav Podzimek <[email protected]>
mendersoftware · Dec 11, 2024 · 9ef1299 · 9ef1299
1 parent 7a8c7a0
commit 9ef1299
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Showing 4 changed files with 16 additions and 3 deletions.
diff --git a/src/mender-update/daemon/state_machine.hpp b/src/mender-update/daemon/state_machine.hpp
@@ -72,6 +72,7 @@ class StateMachine {
 	PollForDeploymentState poll_for_deployment_state_;
 	SendStatusUpdateState send_download_status_state_;
 	UpdateDownloadState update_download_state_;
+	UpdateDownloadCancelState update_download_cancel_state_;
 	SendStatusUpdateState send_install_status_state_;
 	UpdateInstallState update_install_state_;
 

diff --git a/src/mender-update/daemon/state_machine/state_machine.cpp b/src/mender-update/daemon/state_machine/state_machine.cpp
@@ -124,9 +124,12 @@ StateMachine::StateMachine(Context &ctx, events::EventLoop &event_loop) :
 
 	main_states_.AddTransition(update_download_state_,                  se::Success,                     ss.download_leave_,                      tf::Immediate);
 	main_states_.AddTransition(update_download_state_,                  se::StateLoopDetected,           state_loop_state_,                       tf::Immediate);
-	main_states_.AddTransition(update_download_state_,                  se::Failure,                     ss.download_error_,                      tf::Immediate);
+	main_states_.AddTransition(update_download_state_,                  se::Failure,                     update_download_cancel_state_,           tf::Immediate);
 	main_states_.AddTransition(update_download_state_,                  se::NothingToDo,                 ss.download_leave_save_provides,         tf::Immediate);
 
+	// Cannot fail because download cancellation is a void function as there's nothing to do if it fails, anyway.
+	main_states_.AddTransition(update_download_cancel_state_,           se::Success,                     ss.download_error_,                      tf::Immediate);
+
 	main_states_.AddTransition(ss.download_leave_,                      se::Success,                     send_install_status_state_,              tf::Immediate);
 	main_states_.AddTransition(ss.download_leave_,                      se::Failure,                     ss.download_error_,                      tf::Immediate);
 

diff --git a/src/mender-update/daemon/states.cpp b/src/mender-update/daemon/states.cpp
@@ -280,15 +280,13 @@ void UpdateDownloadState::OnEnter(Context &ctx, sm::EventPoster<StateEvent> &pos
 			if (resp->GetStatusCode() != http::StatusOK) {
 				log::Error(
 					"Unexpected status code while fetching artifact: " + resp->GetStatusMessage());
-				ctx.download_client->Cancel();
 				poster.PostEvent(StateEvent::Failure);
 				return;
 			}
 
 			auto http_reader = resp->MakeBodyAsyncReader();
 			if (!http_reader) {
 				log::Error(http_reader.error().String());
-				ctx.download_client->Cancel();
 				poster.PostEvent(StateEvent::Failure);
 				return;
 			}
@@ -455,6 +453,12 @@ void UpdateDownloadState::DoDownload(Context &ctx, sm::EventPoster<StateEvent> &
 	}
 }
 
+void UpdateDownloadCancelState::OnEnter(Context &ctx, sm::EventPoster<StateEvent> &poster) {
+	log::Debug("Entering DownloadCancel state");
+	ctx.download_client->Cancel();
+	poster.PostEvent(StateEvent::Success);
+}
+
 SendStatusUpdateState::SendStatusUpdateState(optional<deployments::DeploymentStatus> status) :
 	status_(status),
 	mode_(FailureMode::Ignore) {

diff --git a/src/mender-update/daemon/states.hpp b/src/mender-update/daemon/states.hpp
@@ -103,6 +103,11 @@ class UpdateDownloadState : virtual public StateType {
 	static void DoDownload(Context &ctx, sm::EventPoster<StateEvent> &poster);
 };
 
+class UpdateDownloadCancelState : virtual public StateType {
+public:
+	void OnEnter(Context &ctx, sm::EventPoster<StateEvent> &poster) override;
+};
+
 class SendStatusUpdateState : virtual public StateType {
 public:
 	// Ignore-failure version.