DFS: Implement ResponseGetDfsReferral

Co-authored-by: Jacob Hales <jahales@users.noreply.github.com>

Author: TalAloni

SMBLibrary.Tests/DFS/ResponseGetDfsReferralTests.cs

@@ -0,0 +1,97 @@
+/* Copyright (C) 2025 Tal Aloni <tal.aloni.il@gmail.com>. All rights reserved.
+ * 
+ * You can redistribute this program and/or modify it under the terms of
+ * the GNU Lesser Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ */
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using SMBLibrary.DFS;
+using System;
+using System.Collections.Generic;
+
+namespace SMBLibrary.Tests.DFS
+{
+    [TestClass]
+    public class ResponseGetDfsReferralTests
+    {
+        [TestMethod]
+        public void ParseResponseGetDfsReferralWithSingleDfsReferralEntryV4()
+        {
+            // Arrange
+            // Returned by Windows Server 2008 R2 SP1
+            byte[] buffer = new byte[]
+            {
+                0x3e ,0x00 ,0x01 ,0x00 ,0x03 ,0x00 ,0x00 ,0x00 ,0x04 ,0x00 ,0x22 ,0x00 ,0x01 ,0x00 ,0x04 ,0x00,
+                0x2c ,0x01 ,0x00 ,0x00 ,0x22 ,0x00 ,0x62 ,0x00 ,0xa2 ,0x00 ,0x00 ,0x00 ,0x00 ,0x00 ,0x00 ,0x00,
+                0x00 ,0x00 ,0x00 ,0x00 ,0x00 ,0x00 ,0x00 ,0x00 ,0x00 ,0x00 ,0x5c ,0x00 ,0x57 ,0x00 ,0x49 ,0x00,
+                0x4e ,0x00 ,0x2d ,0x00 ,0x4d ,0x00 ,0x51 ,0x00 ,0x38 ,0x00 ,0x33 ,0x00 ,0x44 ,0x00 ,0x45 ,0x00,
+                0x35 ,0x00 ,0x4e ,0x00 ,0x47 ,0x00 ,0x37 ,0x00 ,0x32 ,0x00 ,0x5c ,0x00 ,0x44 ,0x00 ,0x66 ,0x00,
+                0x73 ,0x00 ,0x20 ,0x00 ,0x4e ,0x00 ,0x61 ,0x00 ,0x6d ,0x00 ,0x65 ,0x00 ,0x73 ,0x00 ,0x70 ,0x00,
+                0x61 ,0x00 ,0x63 ,0x00 ,0x65 ,0x00 ,0x31 ,0x00 ,0x00 ,0x00 ,0x5c ,0x00 ,0x57 ,0x00 ,0x49 ,0x00,
+                0x4e ,0x00 ,0x2d ,0x00 ,0x4d ,0x00 ,0x51 ,0x00 ,0x38 ,0x00 ,0x33 ,0x00 ,0x44 ,0x00 ,0x45 ,0x00,
+                0x35 ,0x00 ,0x4e ,0x00 ,0x47 ,0x00 ,0x37 ,0x00 ,0x32 ,0x00 ,0x5c ,0x00 ,0x44 ,0x00 ,0x66 ,0x00,
+                0x73 ,0x00 ,0x20 ,0x00 ,0x4e ,0x00 ,0x61 ,0x00 ,0x6d ,0x00 ,0x65 ,0x00 ,0x73 ,0x00 ,0x70 ,0x00,
+                0x61 ,0x00 ,0x63 ,0x00 ,0x65 ,0x00 ,0x31 ,0x00 ,0x00 ,0x00 ,0x5c ,0x00 ,0x57 ,0x00 ,0x49 ,0x00,
+                0x4e ,0x00 ,0x2d ,0x00 ,0x4d ,0x00 ,0x51 ,0x00 ,0x38 ,0x00 ,0x33 ,0x00 ,0x44 ,0x00 ,0x45 ,0x00,
+                0x35 ,0x00 ,0x4e ,0x00 ,0x47 ,0x00 ,0x37 ,0x00 ,0x32 ,0x00 ,0x5c ,0x00 ,0x44 ,0x00 ,0x66 ,0x00,
+                0x73 ,0x00 ,0x20 ,0x00 ,0x4e ,0x00 ,0x61 ,0x00 ,0x6d ,0x00 ,0x65 ,0x00 ,0x73 ,0x00 ,0x70 ,0x00,
+                0x61 ,0x00 ,0x63 ,0x00 ,0x65 ,0x00 ,0x31 ,0x00 ,0x00 ,0x00
+            };
+
+            // Act
+            ResponseGetDfsReferral response = new ResponseGetDfsReferral(buffer);
+
+            // Assert
+            Assert.AreEqual(62, response.PathConsumed);
+            Assert.AreEqual(DfsReferralHeaderFlags.ReferalServers | DfsReferralHeaderFlags.StorageServers , response.ReferralHeaderFlags);
+            Assert.AreEqual(1, response.ReferralEntries.Count);
+            Assert.IsInstanceOfType(response.ReferralEntries[0], typeof(DfsReferralEntryV4));
+
+            DfsReferralEntryV4 entry = (DfsReferralEntryV4)response.ReferralEntries[0];
+            Assert.AreEqual((uint)300, entry.TimeToLive);
+            Assert.AreEqual(DfsReferralEntryFlags.TargetSetBoundary, entry.ReferralEntryFlags);
+            Assert.AreEqual("\\WIN-MQ83DE5NG72\\Dfs Namespace1", entry.DfsPath);
+            Assert.AreEqual("\\WIN-MQ83DE5NG72\\Dfs Namespace1", entry.DfsAlternatePath);
+            Assert.AreEqual("\\WIN-MQ83DE5NG72\\Dfs Namespace1", entry.NetworkAddress);
+            Assert.AreEqual(Guid.Empty, entry.ServiceSiteGuid);
+        }
+
+        [TestMethod]
+        public void Parse_ResponseGetDfsReferralWithSingleDfsReferralEntryV4_GetBytes()
+        {
+            // Arrange
+            ResponseGetDfsReferral response = new ResponseGetDfsReferral();
+            response.PathConsumed = 62;
+            response.ReferralHeaderFlags = DfsReferralHeaderFlags.ReferalServers | DfsReferralHeaderFlags.StorageServers;
+            response.ReferralEntries = new List<DfsReferralEntry>()
+            {
+                new DfsReferralEntryV4()
+                {
+                    TimeToLive = 300,
+                    ReferralEntryFlags = DfsReferralEntryFlags.TargetSetBoundary,
+                    DfsPath = "\\WIN-MQ83DE5NG72\\Dfs Namespace1",
+                    DfsAlternatePath = "\\WIN-MQ83DE5NG72\\Dfs Namespace1",
+                    NetworkAddress = "\\WIN-MQ83DE5NG72\\Dfs Namespace1",
+                    ServiceSiteGuid = Guid.Empty
+                }
+            };
+
+            // Act
+            response = new ResponseGetDfsReferral(response.GetBytes());
+
+            // Assert
+            Assert.AreEqual(62, response.PathConsumed);
+            Assert.AreEqual(DfsReferralHeaderFlags.ReferalServers | DfsReferralHeaderFlags.StorageServers, response.ReferralHeaderFlags);
+            Assert.AreEqual(1, response.ReferralEntries.Count);
+            Assert.IsInstanceOfType(response.ReferralEntries[0], typeof(DfsReferralEntryV4));
+
+            DfsReferralEntryV4 entry = (DfsReferralEntryV4)response.ReferralEntries[0];
+            Assert.AreEqual((uint)300, entry.TimeToLive);
+            Assert.AreEqual(DfsReferralEntryFlags.TargetSetBoundary, entry.ReferralEntryFlags);
+            Assert.AreEqual("\\WIN-MQ83DE5NG72\\Dfs Namespace1", entry.DfsPath);
+            Assert.AreEqual("\\WIN-MQ83DE5NG72\\Dfs Namespace1", entry.DfsAlternatePath);
+            Assert.AreEqual("\\WIN-MQ83DE5NG72\\Dfs Namespace1", entry.NetworkAddress);
+            Assert.AreEqual(Guid.Empty, entry.ServiceSiteGuid);
+        }
+    }
+}

SMBLibrary/DFS/DfsReferralEntry.cs

@@ -1,14 +1,39 @@
-/* Copyright (C) 2014 Tal Aloni <tal.aloni.il@gmail.com>. All rights reserved.
+/* Copyright (C) 2014-2025 Tal Aloni <tal.aloni.il@gmail.com>. All rights reserved.
  * 
  * You can redistribute this program and/or modify it under the terms of
  * the GNU Lesser Public License as published by the Free Software Foundation,
  * either version 3 of the License, or (at your option) any later version.
  */
+using System.IO;
 using Utilities;
 
 namespace SMBLibrary.DFS
 {
     public abstract class DfsReferralEntry
     {
+        public abstract byte[] GetBytes();
+
+        public abstract int Length
+        {
+            get;
+        }
+
+        public static DfsReferralEntry ReadEntry(byte[] buffer, ref int offset)
+        {
+            ushort versionNumber = LittleEndianConverter.ToUInt16(buffer, offset + 0);
+            switch (versionNumber)
+            {
+                case 1:
+                    return new DfsReferralEntryV1(buffer, ref offset);
+                case 2:
+                    return new DfsReferralEntryV2(buffer, ref offset);
+                case 3:
+                    return new DfsReferralEntryV3(buffer, ref offset);
+                case 4:
+                    return new DfsReferralEntryV4(buffer, ref offset);
+                default:
+                    throw new InvalidDataException($"DfsReferralEntry version {versionNumber} is invalid");
+            }
+        }
     }
 }

SMBLibrary/DFS/DfsReferralEntryV1.cs

@@ -0,0 +1,59 @@
+/* Copyright (C) 2025 Tal Aloni <tal.aloni.il@gmail.com>. All rights reserved.
+ * 
+ * You can redistribute this program and/or modify it under the terms of
+ * the GNU Lesser Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ */
+using Utilities;
+
+namespace SMBLibrary.DFS
+{
+    /// <summary>
+    /// [MS-DFSC] 2.2.5.1 DFS_REFERRAL_V1
+    /// </summary>
+    public class DfsReferralEntryV1 : DfsReferralEntry
+    {
+        public const int FixedLength = 8;
+
+        public ushort VersionNumber;
+        public ushort Size;
+        public DfsServerType ServerType;
+        public DfsReferralEntryFlags ReferralEntryFlags;
+        public string ShareName;
+
+        public DfsReferralEntryV1()
+        {
+            VersionNumber = 1;
+        }
+
+        public DfsReferralEntryV1(byte[] buffer, ref int offset)
+        {
+            VersionNumber = LittleEndianConverter.ToUInt16(buffer, offset + 0);
+            Size = LittleEndianConverter.ToUInt16(buffer, offset + 2);
+            ServerType = (DfsServerType)LittleEndianConverter.ToUInt16(buffer, offset + 4);
+            ReferralEntryFlags = (DfsReferralEntryFlags)LittleEndianConverter.ToUInt16(buffer, offset + 6);
+            ShareName = ByteReader.ReadNullTerminatedUTF16String(buffer, offset + 8);
+
+            offset += Size;
+        }
+
+        public override byte[] GetBytes()
+        {
+            byte[] buffer = new byte[this.Length];
+            LittleEndianWriter.WriteUInt16(buffer, 0, VersionNumber);
+            LittleEndianWriter.WriteUInt16(buffer, 2, (ushort)buffer.Length);
+            LittleEndianWriter.WriteUInt16(buffer, 4, (ushort)ServerType);
+            LittleEndianWriter.WriteUInt16(buffer, 6, (ushort)ReferralEntryFlags);
+            ByteWriter.WriteNullTerminatedUTF16String(buffer, 8, ShareName);
+            return buffer;
+        }
+
+        public override int Length
+        {
+            get
+            {
+                return FixedLength + (ShareName.Length + 1) * 2;
+            }
+        }
+    }
+}

SMBLibrary/DFS/DfsReferralEntryV2.cs

@@ -0,0 +1,86 @@
+/* Copyright (C) 2025 Tal Aloni <tal.aloni.il@gmail.com>. All rights reserved.
+ * 
+ * You can redistribute this program and/or modify it under the terms of
+ * the GNU Lesser Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ */
+using Utilities;
+
+namespace SMBLibrary.DFS
+{
+    /// <summary>
+    /// [MS-DFSC] 2.2.5.2 DFS_REFERRAL_V2
+    /// </summary>
+    public class DfsReferralEntryV2 : DfsReferralEntry
+    {
+        public const int FixedLength = 22;
+
+        public ushort VersionNumber;
+        public ushort Size;
+        public DfsServerType ServerType;
+        public DfsReferralEntryFlags ReferralEntryFlags;
+        public uint Proximity;
+        public uint TimeToLive;
+        public string DfsPath;
+        public string DfsAlternatePath;
+        public string NetworkAddress;
+
+        public DfsReferralEntryV2()
+        {
+            VersionNumber = 2;
+        }
+
+        public DfsReferralEntryV2(byte[] buffer, ref int offset)
+        {
+            VersionNumber = LittleEndianConverter.ToUInt16(buffer, offset + 0);
+            Size = LittleEndianConverter.ToUInt16(buffer, offset + 2);
+            ServerType = (DfsServerType)LittleEndianConverter.ToUInt16(buffer, offset + 4);
+            ReferralEntryFlags = (DfsReferralEntryFlags)LittleEndianConverter.ToUInt16(buffer, offset + 6);
+
+            Proximity = LittleEndianConverter.ToUInt32(buffer, offset + 8);
+            TimeToLive = LittleEndianConverter.ToUInt32(buffer, offset + 12);
+
+            ushort dfsPathOffset = LittleEndianConverter.ToUInt16(buffer, offset + 16);
+            ushort dfsAlternatePathOffset = LittleEndianConverter.ToUInt16(buffer, offset + 18);
+            ushort networkAddressOffset = LittleEndianConverter.ToUInt16(buffer, offset + 20);
+
+            DfsPath = ByteReader.ReadNullTerminatedUTF16String(buffer, offset + dfsPathOffset);
+            DfsAlternatePath = ByteReader.ReadNullTerminatedUTF16String(buffer, offset + dfsAlternatePathOffset);
+            NetworkAddress = ByteReader.ReadNullTerminatedUTF16String(buffer, offset + networkAddressOffset);
+
+            offset += Size;
+        }
+
+        public override byte[] GetBytes()
+        {
+            byte[] buffer = new byte[Length];
+            LittleEndianWriter.WriteUInt16(buffer, 0, VersionNumber);
+            LittleEndianWriter.WriteUInt16(buffer, 2, (ushort)buffer.Length);
+            LittleEndianWriter.WriteUInt16(buffer, 4, (ushort)ServerType);
+            LittleEndianWriter.WriteUInt16(buffer, 6, (ushort)ReferralEntryFlags);
+            LittleEndianWriter.WriteUInt32(buffer, 8, Proximity);
+            LittleEndianWriter.WriteUInt32(buffer, 12, TimeToLive);
+
+            ushort dfsPathOffset = FixedLength;
+            ushort dfsAlternatePathOffset = (ushort)(dfsPathOffset + (DfsPath.Length + 1) * 2);
+            ushort networkAddressOffset = (ushort)(dfsAlternatePathOffset + (DfsAlternatePath.Length + 1) * 2);
+            LittleEndianWriter.WriteUInt16(buffer, 16, dfsPathOffset);
+            LittleEndianWriter.WriteUInt16(buffer, 18, dfsAlternatePathOffset);
+            LittleEndianWriter.WriteUInt16(buffer, 20, networkAddressOffset);
+
+            ByteWriter.WriteNullTerminatedUTF16String(buffer, dfsPathOffset, DfsPath);
+            ByteWriter.WriteNullTerminatedUTF16String(buffer, dfsAlternatePathOffset, DfsAlternatePath);
+            ByteWriter.WriteNullTerminatedUTF16String(buffer, networkAddressOffset, NetworkAddress);
+
+            return buffer;
+        }
+
+        public override int Length
+        {
+            get
+            {
+                return FixedLength + (DfsPath.Length + 1 + DfsAlternatePath.Length + 1 + NetworkAddress.Length + 1) * 2;
+            }
+        }
+    }
+}