From 1036a6c78cbf00305a9e7b0bde0009931369a1f0 Mon Sep 17 00:00:00 2001
From: Uwe Seimet <Uwe.Seimet@seimet.de>
Date: Thu, 24 Oct 2024 23:42:36 +0200
Subject: [PATCH] Update error handling

---
 cpp/devices/tape.cpp   | 14 +++++++++++++-
 cpp/test/tape_test.cpp | 11 ++++++-----
 2 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/cpp/devices/tape.cpp b/cpp/devices/tape.cpp
index 78b9bf92..b9307ab7 100644
--- a/cpp/devices/tape.cpp
+++ b/cpp/devices/tape.cpp
@@ -178,6 +178,10 @@ int Tape::ReadData(span<uint8_t> buf)
 
     const int length = tar_mode ? GetBlockSize() : GetVariableBlockSize();
 
+    if (static_cast<off_t>(position + length) > GetFileSize()) {
+        throw scsi_exception(sense_key::blank_check);
+    }
+
     file.seekg(position, ios::beg);
     file.read((char*)buf.data(), length);
     if (file.fail()) {
@@ -198,6 +202,10 @@ int Tape::WriteData(span<const uint8_t> buf, scsi_command)
 
     const int length = GetController()->GetChunkSize();
 
+    if (static_cast<off_t>(position + length) > GetFileSize()) {
+        throw scsi_exception(sense_key::blank_check);
+    }
+
     if (!tar_mode) {
         WriteMetaData(object_type::BLOCK, length);
     }
@@ -551,6 +559,10 @@ void Tape::WriteMetaData(Tape::object_type type, uint32_t size)
 {
     assert(size < 65536);
 
+    if (static_cast<off_t>(position + sizeof(meta_data_t)) > GetFileSize()) {
+        throw scsi_exception(sense_key::blank_check);
+    }
+
     meta_data_t meta_data;
     memcpy(meta_data.magic.data(), MAGIC, 4);
     meta_data.type = type;
@@ -644,7 +656,7 @@ uint32_t Tape::GetByteCount() const
             GetSignedInt24(GetController()->GetCdb(), 2);
 
     // The non-fixed block size must be a multiple of 4 (see SSC-5)
-    if ((!fixed && count % 4) || static_cast<off_t>(position + count) > filesize) {
+    if (!fixed && count % 4) {
         throw scsi_exception(sense_key::illegal_request, asc::invalid_field_in_cdb);
     }
 
diff --git a/cpp/test/tape_test.cpp b/cpp/test/tape_test.cpp
index 229df72b..daeb73f6 100644
--- a/cpp/test/tape_test.cpp
+++ b/cpp/test/tape_test.cpp
@@ -188,13 +188,12 @@ TEST(TapeTest, Erase6)
 {
     auto [controller, tape] = CreateTape();
 
+    CreateTapeFile(*tape, 4567);
+
     tape->SetProtected(true);
     TestShared::Dispatch(*tape, scsi_command::erase6, sense_key::data_protect, asc::write_protected);
 
     tape->SetProtected(false);
-    TestShared::Dispatch(*tape, scsi_command::erase6, sense_key::medium_error, asc::write_error);
-
-    CreateTapeFile(*tape, 4567);
     EXPECT_NO_THROW(tape->Dispatch(scsi_command::erase6));
     CheckPosition(*controller, *tape, 0);
     EXPECT_EQ(0b10000000, controller->GetBuffer()[0]) << "EOP must be set";
@@ -275,12 +274,14 @@ TEST(TapeTest, WriteFileMarks6)
     controller->SetCdbByte(1, 0b001);
     EXPECT_NO_THROW(tape->Dispatch(scsi_command::write_filemarks6));
 
+    CreateTapeFile(*tape);
+
     // Count > 0
     controller->SetCdbByte(2, 1);
-    TestShared::Dispatch(*tape, scsi_command::write_filemarks6, sense_key::medium_error, asc::write_error);
+    TestShared::Dispatch(*tape, scsi_command::write_filemarks6, sense_key::blank_check,
+        asc::no_additional_sense_information);
 
     tape->SetProtected(true);
-    controller->SetCdbByte(1, 0b001);
     TestShared::Dispatch(*tape, scsi_command::write_filemarks6, sense_key::data_protect, asc::write_protected);
 }