Initial commit - WPinternals 2.6

DiscUtils/Partitions/GptHeader.cs

@@ -0,0 +1,144 @@
+//
+// Copyright (c) 2008-2011, Kenneth Bell
+//
+// Permission is hereby granted, free of charge, to any person obtaining a
+// copy of this software and associated documentation files (the "Software"),
+// to deal in the Software without restriction, including without limitation
+// the rights to use, copy, modify, merge, publish, distribute, sublicense,
+// and/or sell copies of the Software, and to permit persons to whom the
+// Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+//
+
+namespace DiscUtils.Partitions
+{
+    using System;
+
+    internal class GptHeader
+    {
+        public const string GptSignature = "EFI PART";
+
+        public string Signature;
+        public uint Version;
+        public int HeaderSize;
+        public uint Crc;
+        public long HeaderLba;
+        public long AlternateHeaderLba;
+        public long FirstUsable;
+        public long LastUsable;
+        public Guid DiskGuid;
+        public long PartitionEntriesLba;
+        public uint PartitionEntryCount;
+        public int PartitionEntrySize;
+        public uint EntriesCrc;
+
+        public byte[] Buffer;
+
+        public GptHeader(int sectorSize)
+        {
+            Signature = GptSignature;
+            Version = 0x00010000;
+            HeaderSize = 92;
+            Buffer = new byte[sectorSize];
+        }
+
+        public GptHeader(GptHeader toCopy)
+        {
+            Signature = toCopy.Signature;
+            Version = toCopy.Version;
+            HeaderSize = toCopy.HeaderSize;
+            Crc = toCopy.Crc;
+            HeaderLba = toCopy.HeaderLba;
+            AlternateHeaderLba = toCopy.AlternateHeaderLba;
+            FirstUsable = toCopy.FirstUsable;
+            LastUsable = toCopy.LastUsable;
+            DiskGuid = toCopy.DiskGuid;
+            PartitionEntriesLba = toCopy.PartitionEntriesLba;
+            PartitionEntryCount = toCopy.PartitionEntryCount;
+            PartitionEntrySize = toCopy.PartitionEntrySize;
+            EntriesCrc = toCopy.EntriesCrc;
+
+            Buffer = new byte[toCopy.Buffer.Length];
+            Array.Copy(toCopy.Buffer, Buffer, Buffer.Length);
+        }
+
+        public bool ReadFrom(byte[] buffer, int offset)
+        {
+            Signature = Utilities.BytesToString(buffer, offset + 0, 8);
+            Version = Utilities.ToUInt32LittleEndian(buffer, offset + 8);
+            HeaderSize = Utilities.ToInt32LittleEndian(buffer, offset + 12);
+            Crc = Utilities.ToUInt32LittleEndian(buffer, offset + 16);
+            HeaderLba = Utilities.ToInt64LittleEndian(buffer, offset + 24);
+            AlternateHeaderLba = Utilities.ToInt64LittleEndian(buffer, offset + 32);
+            FirstUsable = Utilities.ToInt64LittleEndian(buffer, offset + 40);
+            LastUsable = Utilities.ToInt64LittleEndian(buffer, offset + 48);
+            DiskGuid = Utilities.ToGuidLittleEndian(buffer, offset + 56);
+            PartitionEntriesLba = Utilities.ToInt64LittleEndian(buffer, offset + 72);
+            PartitionEntryCount = Utilities.ToUInt32LittleEndian(buffer, offset + 80);
+            PartitionEntrySize = Utilities.ToInt32LittleEndian(buffer, offset + 84);
+            EntriesCrc = Utilities.ToUInt32LittleEndian(buffer, offset + 88);
+
+            // In case the header has new fields unknown to us, store the entire header
+            // as a byte array
+            Buffer = new byte[HeaderSize];
+            Array.Copy(buffer, offset, Buffer, 0, HeaderSize);
+
+            // Reject obviously invalid data
+            if (Signature != GptSignature || HeaderSize == 0)
+            {
+                return false;
+            }
+
+            return Crc == CalcCrc(buffer, offset, HeaderSize);
+        }
+
+        public void WriteTo(byte[] buffer, int offset)
+        {
+            // First, copy the cached header to allow for unknown fields
+            Array.Copy(Buffer, 0, buffer, offset, Buffer.Length);
+
+            // Next, write the fields
+            Utilities.StringToBytes(Signature, buffer, offset + 0, 8);
+            Utilities.WriteBytesLittleEndian(Version, buffer, offset + 8);
+            Utilities.WriteBytesLittleEndian(HeaderSize, buffer, offset + 12);
+            Utilities.WriteBytesLittleEndian((uint)0, buffer, offset + 16);
+            Utilities.WriteBytesLittleEndian(HeaderLba, buffer, offset + 24);
+            Utilities.WriteBytesLittleEndian(AlternateHeaderLba, buffer, offset + 32);
+            Utilities.WriteBytesLittleEndian(FirstUsable, buffer, offset + 40);
+            Utilities.WriteBytesLittleEndian(LastUsable, buffer, offset + 48);
+            Utilities.WriteBytesLittleEndian(DiskGuid, buffer, offset + 56);
+            Utilities.WriteBytesLittleEndian(PartitionEntriesLba, buffer, offset + 72);
+            Utilities.WriteBytesLittleEndian(PartitionEntryCount, buffer, offset + 80);
+            Utilities.WriteBytesLittleEndian(PartitionEntrySize, buffer, offset + 84);
+            Utilities.WriteBytesLittleEndian(EntriesCrc, buffer, offset + 88);
+
+            // Calculate & write the CRC
+            Utilities.WriteBytesLittleEndian(CalcCrc(buffer, offset, HeaderSize), buffer, offset + 16);
+
+            // Update the cached copy - re-allocate the buffer to allow for HeaderSize potentially having changed
+            Buffer = new byte[HeaderSize];
+            Array.Copy(buffer, offset, Buffer, 0, HeaderSize);
+        }
+
+        internal static uint CalcCrc(byte[] buffer, int offset, int count)
+        {
+            byte[] temp = new byte[count];
+            Array.Copy(buffer, offset, temp, 0, count);
+
+            // Reset CRC field
+            Utilities.WriteBytesLittleEndian((uint)0, temp, 16);
+
+            return Crc32LittleEndian.Compute(Crc32Algorithm.Common, temp, 0, count);
+        }
+    }
+}