Cleaned up new code

Author: LTRData

Library/DiscUtils.Iscsi/ScsiSenseData.cs

@@ -115,7 +115,10 @@ internal ScsiSenseData(
     public override string ToString()
     {
         if (KnownSenseCode is ScsiKnownSenseCode known)
+        {
             return $"{KnownSenseCode} ({Description}) [SK={SenseKey}, ASC=0x{AdditionalSenseCode:X2}, ASCQ=0x{AdditionalSenseCodeQualifier:X2}]";
+        }
+
         return $"{Description} [SK={SenseKey}, ASC=0x{AdditionalSenseCode:X2}, ASCQ=0x{AdditionalSenseCodeQualifier:X2}]";
     }
 }
@@ -173,31 +176,130 @@ private static readonly Dictionary<ScsiKnownSenseCode, string> KnownDescriptions
             { ScsiKnownSenseCode.AbortedCommand_ScsiParityError, "SCSI parity error (command aborted)" },
         };
 
+    /// <summary>
+    /// Parse SCSI sense data from a byte array (fixed or descriptor format).
+    /// </summary>
+    /// <param name="buffer">Sense data buffer.</param>
+    /// <param name="sense"></param>
+    /// <param name="offset">Offset into the buffer where sense data starts.</param>
     public static bool TryParse(byte[] buffer, out ScsiSenseData sense, int offset = 0)
     {
         sense = null;
 
-        try
+        // --- Top-level basic validation ---------------------------------------
+        if (buffer == null)
         {
-            // Basic validation — but never throw.
-            if (buffer == null)
-                return false;
-            if (offset < 0 || offset >= buffer.Length)
-                return false;
+            return false;
+        }
+
+        if (offset < 0 || offset >= buffer.Length)
+        {
+            return false;
+        }
+
+        // Need at least 4 bytes to even know format
+        if (buffer.Length - offset < 4)
+        {
+            return false;
+        }
+
+        // --- Read response code safely ----------------------------------------
+        var b0 = buffer[offset];
+        var responseCode = (byte)(b0 & 0x7F);
+
+        var isDescriptorFormat = responseCode is 0x72 or 0x73;
+        var isFixedFormat = responseCode is 0x70 or 0x71;
 
-            // Very small sense buffers cannot be parsed.
+        if (!isDescriptorFormat && !isFixedFormat)
+        {
+            // Unknown/unsupported format
+            return false;
+        }
+
+        ScsiSenseKey senseKey;
+        byte asc = 0;
+        byte ascq = 0;
+        uint? information = null;
+
+        // --- Descriptor format (0x72 or 0x73) ---------------------------------
+        if (isDescriptorFormat)
+        {
+            // Descriptor format header is at least 4 bytes
             if (buffer.Length - offset < 4)
+            {
                 return false;
+            }
 
-            sense = Parse(buffer, offset);
-            return true;
+            // Byte 1: Sense key (low nibble)
+            senseKey = (ScsiSenseKey)(buffer[offset + 1] & 0x0F);
+
+            // Byte 2: ASC
+            asc = buffer[offset + 2];
+
+            // Byte 3: ASCQ
+            ascq = buffer[offset + 3];
+
+            // INFORMATION descriptor parsing optional and skipped here
         }
-        catch
+        // --- Fixed format (0x70 or 0x71) --------------------------------------
+        else
         {
-            // Ensure no exception leaks out.
-            sense = null;
-            return false;
+            // Need at least 14 bytes for fixed‐format ASC/ASCQ + info
+            if (buffer.Length - offset < 14)
+            {
+                return false;
+            }
+
+            // Byte 2: sense key (low nibble)
+            senseKey = (ScsiSenseKey)(buffer[offset + 2] & 0x0F);
+
+            // Bytes 3–6: INFORMATION (often LBA)
+            unchecked
+            {
+                information =
+                    (uint)((buffer[offset + 3] << 24) |
+                           (buffer[offset + 4] << 16) |
+                           (buffer[offset + 5] << 8) |
+                            buffer[offset + 6]);
+            }
+
+            // Byte 12: ASC
+            asc = buffer[offset + 12];
+
+            // Byte 13: ASCQ
+            ascq = buffer[offset + 13];
+        }
+
+        // --- Resolve KCQ into known enum --------------------------------------
+        ScsiKnownSenseCode? knownCode = null;
+        string description;
+
+        if (KnownMap.TryGetValue((senseKey, asc, ascq), out var found))
+        {
+            knownCode = found;
+            if (!KnownDescriptions.TryGetValue(found, out description))
+            {
+                description = found.ToString();
+            }
         }
+        else
+        {
+            // Fallback description
+            description = GetDefaultDescription(senseKey, asc, ascq);
+        }
+
+        sense = new ScsiSenseData(
+            responseCode: responseCode,
+            isCurrent: responseCode is 0x70 or 0x72,
+            isDescriptor: isDescriptorFormat,
+            senseKey: senseKey,
+            asc: asc,
+            ascq: ascq,
+            information: information,
+            known: knownCode,
+            description: description);
+
+        return true;
     }
 
     /// <summary>
@@ -207,19 +309,27 @@ public static bool TryParse(byte[] buffer, out ScsiSenseData sense, int offset =
     /// <param name="offset">Offset into the buffer where sense data starts.</param>
     public static ScsiSenseData Parse(byte[] buffer, int offset = 0)
     {
-        if (buffer == null) throw new ArgumentNullException(nameof(buffer));
+        if (buffer == null)
+        {
+            throw new ArgumentNullException(nameof(buffer));
+        }
+
         if (offset < 0 || offset >= buffer.Length)
+        {
             throw new ArgumentOutOfRangeException(nameof(offset));
+        }
 
         if (buffer.Length - offset < 4)
+        {
             throw new ArgumentException("Sense buffer is too short.", nameof(buffer));
+        }
 
         // Byte 0: Response code (low 7 bits) and VALID bit (bit 7 in fixed format).
-        byte raw0 = buffer[offset + 0];
-        byte responseCode = (byte)(raw0 & 0x7F);
+        var raw0 = buffer[offset + 0];
+        var responseCode = (byte)(raw0 & 0x7F);
 
-        bool isCurrent = responseCode == 0x70 || responseCode == 0x72;
-        bool isDescriptorFormat = responseCode == 0x72 || responseCode == 0x73;
+        var isCurrent = responseCode is 0x70 or 0x72;
+        var isDescriptorFormat = responseCode is 0x72 or 0x73;
 
         ScsiSenseKey senseKey;
         byte asc;
@@ -233,7 +343,9 @@ public static ScsiSenseData Parse(byte[] buffer, int offset = 0)
             // Byte 2: ASC
             // Byte 3: ASCQ
             if (buffer.Length - offset < 4)
+            {
                 throw new ArgumentException("Descriptor sense buffer is too short.", nameof(buffer));
+            }
 
             senseKey = (ScsiSenseKey)(buffer[offset + 1] & 0x0F);
             asc = buffer[offset + 2];
@@ -250,7 +362,9 @@ public static ScsiSenseData Parse(byte[] buffer, int offset = 0)
             // Byte 12: ASC
             // Byte 13: ASCQ
             if (buffer.Length - offset < 14)
+            {
                 throw new ArgumentException("Fixed-format sense buffer is too short.", nameof(buffer));
+            }
 
             senseKey = (ScsiSenseKey)(buffer[offset + 2] & 0x0F);
 
@@ -273,7 +387,9 @@ public static ScsiSenseData Parse(byte[] buffer, int offset = 0)
         {
             knownCode = found;
             if (!KnownDescriptions.TryGetValue(found, out description))
+            {
                 description = found.ToString();
+            }
         }
         else
         {
@@ -295,9 +411,9 @@ public static ScsiSenseData Parse(byte[] buffer, int offset = 0)
 
     private static (ScsiSenseKey key, byte asc, byte ascq) ScsiTriple(ScsiKnownSenseCode code)
     {
-        int value = (int)code;
-        byte asc = (byte)((value >> 8) & 0xFF);
-        byte ascq = (byte)(value & 0xFF);
+        var value = (int)code;
+        var asc = (byte)((value >> 8) & 0xFF);
+        var ascq = (byte)(value & 0xFF);
         ScsiSenseKey key = (ScsiSenseKey)((value >> 16) & 0x0F);
         return (key, asc, ascq);
     }