From 03d7258d3326c2c96ef3757009e1b3a8fc951384 Mon Sep 17 00:00:00 2001
From: Martin Stein <martin.stein@genode-labs.com>
Date: Thu, 1 Jun 2023 10:48:05 +0200
Subject: [PATCH] tresor: better handling of hash mismatches

Instead of throwing an uncaught exception, the corresponding request is marked
failed.

Ref #4819
---
 repos/gems/src/lib/tresor/free_tree.cc        | 31 ++++++++++++++-----
 .../src/lib/tresor/include/tresor/free_tree.h |  9 ++++++
 .../src/lib/tresor/include/tresor/meta_tree.h |  2 ++
 repos/gems/src/lib/tresor/meta_tree.cc        | 12 +++----
 4 files changed, 41 insertions(+), 13 deletions(-)

diff --git a/repos/gems/src/lib/tresor/free_tree.cc b/repos/gems/src/lib/tresor/free_tree.cc
index de99f2a0d4..a012ce6b3b 100644
--- a/repos/gems/src/lib/tresor/free_tree.cc
+++ b/repos/gems/src/lib/tresor/free_tree.cc
@@ -684,6 +684,26 @@ void Free_tree::_execute_update(Channel         &chan,
 }
 
 
+void Free_tree::_mark_req_failed(Channel    &chan,
+                                 bool       &progress,
+                                 char const *str)
+{
+	error(chan._request.type_name(), " request failed, reason: \"", str, "\"");
+	chan._request._success = false;
+	chan._state = Channel::COMPLETE;
+	progress = true;
+}
+
+
+void Free_tree::_mark_req_successful(Channel &channel,
+                                     bool    &progress)
+{
+	channel._request._success = true;
+	channel._state = Channel::COMPLETE;
+	progress = true;
+}
+
+
 void Free_tree::_execute(Channel         &chan,
                          Snapshots const &active_snaps,
                          Generation       last_secured_gen,
@@ -711,19 +731,16 @@ void Free_tree::_execute(Channel         &chan,
 		_execute_update(chan, active_snaps, last_secured_gen, progress);
 		break;
 	case Channel::UPDATE_COMPLETE:
-		chan._request._success = true;
-		chan._state = Channel::COMPLETE;
+		_mark_req_successful(chan, progress);
 		break;
 	case Channel::COMPLETE:
 		break;
 	case Channel::NOT_ENOUGH_FREE_BLOCKS:
-		chan._request._success = false;
-		chan._state = Channel::COMPLETE;
-		progress = true;
+		_mark_req_failed(chan, progress, "not enough free blocks");
 		break;
 	case Channel::TREE_HASH_MISMATCH:
-		class Exception_1 { };
-		throw Exception_1 { };
+		_mark_req_failed(chan, progress, "node hash mismatch");
+		break;
 	}
 }
 
diff --git a/repos/gems/src/lib/tresor/include/tresor/free_tree.h b/repos/gems/src/lib/tresor/include/tresor/free_tree.h
index d2132f3681..bbea27314a 100644
--- a/repos/gems/src/lib/tresor/include/tresor/free_tree.h
+++ b/repos/gems/src/lib/tresor/include/tresor/free_tree.h
@@ -110,6 +110,8 @@ class Tresor::Free_tree_request : public Module_request
 
 		static char const *type_to_string(Type type);
 
+		char const *type_name() const { return type_to_string(_type); }
+
 
 		/********************
 		 ** Module_request **
@@ -395,6 +397,13 @@ class Tresor::Free_tree : public Module
 		                           Block       const &block_data,
 		                           Type_1_node_block &entries);
 
+		void _mark_req_failed(Channel    &chan,
+		                      bool       &progress,
+		                      char const *str);
+
+		void _mark_req_successful(Channel &chan,
+		                          bool    &progress);
+
 		void
 		_exchange_type_2_leaves(Generation              free_gen,
 		                        Tree_level_index        max_level,
diff --git a/repos/gems/src/lib/tresor/include/tresor/meta_tree.h b/repos/gems/src/lib/tresor/include/tresor/meta_tree.h
index d667263681..94c2fd6254 100644
--- a/repos/gems/src/lib/tresor/include/tresor/meta_tree.h
+++ b/repos/gems/src/lib/tresor/include/tresor/meta_tree.h
@@ -78,6 +78,8 @@ class Tresor::Meta_tree_request : public Module_request
 
 		static char const *type_to_string(Type type);
 
+		char const *type_name() const { return type_to_string(_type); }
+
 
 		/********************
 		 ** Module_request **
diff --git a/repos/gems/src/lib/tresor/meta_tree.cc b/repos/gems/src/lib/tresor/meta_tree.cc
index deb18d2df7..3159c3d7ae 100644
--- a/repos/gems/src/lib/tresor/meta_tree.cc
+++ b/repos/gems/src/lib/tresor/meta_tree.cc
@@ -225,13 +225,13 @@ void Meta_tree::generated_request_complete(Module_request &mod_req)
 }
 
 
-void Meta_tree::_mark_req_failed(Channel    &channel,
+void Meta_tree::_mark_req_failed(Channel    &chan,
                                  bool       &progress,
                                  char const *str)
 {
-	error("request failed: failed to ", str);
-	channel._request._success = false;
-	channel._state = Channel::COMPLETE;
+	error(chan._request.type_name(), " request failed, reason: \"", str, "\"");
+	chan._request._success = false;
+	chan._state = Channel::COMPLETE;
 	progress = true;
 }
 
@@ -464,8 +464,8 @@ void Meta_tree::execute(bool &progress)
 		case Channel::COMPLETE:
 			break;
 		case Channel::TREE_HASH_MISMATCH:
-			class Exception_1 { };
-			throw Exception_1 { };
+			_mark_req_failed(channel, progress, "node hash mismatch");
+			break;
 		}
 	}
 }