Update UserAgent to pipe-delimited format

src/Microsoft.Data.SqlClient/netcore/src/Microsoft.Data.SqlClient.csproj

@@ -825,6 +825,9 @@
     <Compile Include="$(CommonSourceRoot)Microsoft\Data\SqlClient\TransactionRequest.cs">
         <Link>Microsoft\Data\SqlClient\TransactionRequest.cs</Link>
     </Compile>
+    <Compile Include="$(CommonSourceRoot)Microsoft\Data\SqlClient\UserAgent.cs">
+      <Link>Microsoft\Data\SqlClient\UserAgent.cs</Link>
+    </Compile>
     <Compile Include="$(CommonSourceRoot)Microsoft\Data\SqlClient\VirtualSecureModeEnclaveProvider.cs">
       <Link>Microsoft\Data\SqlClient\VirtualSecureModeEnclaveProvider.cs</Link>
     </Compile>
@@ -846,12 +849,6 @@
     <Compile Include="$(CommonSourceRoot)Microsoft\Data\SqlTypes\SqlVector.cs">
       <Link>Microsoft\Data\SqlTypes\SqlVector.cs</Link>
     </Compile>
-    <Compile Include="$(CommonSourceRoot)Microsoft\Data\SqlClient\UserAgent\UserAgentInfo.cs">
-      <Link>Microsoft\Data\SqlClient\UserAgent\UserAgentInfo.cs</Link>
-    </Compile>
-    <Compile Include="$(CommonSourceRoot)Microsoft\Data\SqlClient\UserAgent\UserAgentInfoDto.cs">
-      <Link>Microsoft\Data\SqlClient\UserAgent\UserAgentInfoDto.cs</Link>
-    </Compile>
     <Compile Include="$(CommonSourceRoot)Resources\ResCategoryAttribute.cs">
       <Link>Resources\ResCategoryAttribute.cs</Link>
     </Compile>

src/Microsoft.Data.SqlClient/netfx/src/Microsoft.Data.SqlClient.csproj

@@ -968,6 +968,9 @@
     <Compile Include="$(CommonSourceRoot)Microsoft\Data\SqlClient\TransactionRequest.cs">
         <Link>Microsoft\Data\SqlClient\TransactionRequest.cs</Link>
     </Compile>
+    <Compile Include="$(CommonSourceRoot)Microsoft\Data\SqlClient\UserAgent.cs">
+      <Link>Microsoft\Data\SqlClient\UserAgent.cs</Link>
+    </Compile>
     <Compile Include="$(CommonSourceRoot)Microsoft\Data\SqlClient\Utilities\BufferWriterExtensions.netfx.cs">
       <Link>Microsoft\Data\SqlClient\Utilities\BufferWriterExtensions.netfx.cs</Link>
     </Compile>
@@ -1001,12 +1004,6 @@
     <Compile Include="$(CommonSourceRoot)Microsoft\Data\SqlTypes\SqlVector.cs">
       <Link>Microsoft\Data\SqlTypes\SqlVector.cs</Link>
     </Compile>
-    <Compile Include="$(CommonSourceRoot)Microsoft\Data\SqlClient\UserAgent\UserAgentInfo.cs">
-      <Link>Microsoft\Data\SqlClient\UserAgent\UserAgentInfo.cs</Link>
-    </Compile>
-    <Compile Include="$(CommonSourceRoot)Microsoft\Data\SqlClient\UserAgent\UserAgentInfoDto.cs">
-      <Link>Microsoft\Data\SqlClient\UserAgent\UserAgentInfoDto.cs</Link>
-    </Compile>
     <Compile Include="$(CommonSourceRoot)Resources\ResDescriptionAttribute.cs">
       <Link>Resources\ResDescriptionAttribute.cs</Link>
     </Compile>

src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/LocalAppContextSwitches.cs

@@ -330,8 +330,11 @@ public static bool IgnoreServerProvidedFailoverPartner
                 return s_ignoreServerProvidedFailoverPartner == Tristate.True;
             }
         }
+
         /// <summary>
-        /// When set to true, the user agent feature is enabled and the driver will send the user agent string to the server.
+        /// When set to true, the user agent feature is enabled and the driver
+        /// will send the user agent string to the server as a LOGIN7 feature
+        /// extension.
         /// </summary>
         public static bool EnableUserAgent
         {

src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/SqlError.cs

@@ -3,6 +3,7 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
+using Microsoft.Data.Common.ConnectionString;
 
 namespace Microsoft.Data.SqlClient
 {
@@ -11,7 +12,7 @@ namespace Microsoft.Data.SqlClient
     public sealed class SqlError
     {
         // bug fix - MDAC 48965 - missing source of exception
-        private readonly string _source = TdsEnums.SQL_PROVIDER_NAME;
+        private readonly string _source = DbConnectionStringDefaults.ApplicationName;
         private readonly int _number;
         private readonly byte _state;
         private readonly byte _errorClass;

src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/SqlException.cs

@@ -10,6 +10,7 @@
 using System.Globalization;
 using System.Runtime.Serialization;
 using System.Text;
+using Microsoft.Data.Common.ConnectionString;
 
 namespace Microsoft.Data.SqlClient
 {
@@ -112,7 +113,7 @@ public override void GetObjectData(SerializationInfo si, StreamingContext contex
         public byte State => Errors.Count > 0 ? Errors[0].State : default;
 
         /// <include file='../../../../../../doc/snippets/Microsoft.Data.SqlClient/SqlException.xml' path='docs/members[@name="SqlException"]/Source/*' />
-        override public string Source => TdsEnums.SQL_PROVIDER_NAME;
+        override public string Source => DbConnectionStringDefaults.ApplicationName;
 
 
 #if NET

src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/TdsEnums.cs

@@ -13,10 +13,6 @@ namespace Microsoft.Data.SqlClient
     internal static class TdsEnums
     {
         // internal tdsparser constants
-
-
-        public const string SQL_PROVIDER_NAME = DbConnectionStringDefaults.ApplicationName;
-
         public static readonly decimal SQL_SMALL_MONEY_MIN = new(-214748.3648);
         public static readonly decimal SQL_SMALL_MONEY_MAX = new(214748.3647);
 
@@ -987,9 +983,6 @@ internal enum FedAuthInfoId : byte
         internal const byte MAX_SUPPORTED_VECTOR_VERSION = 0x01;
         internal const int VECTOR_HEADER_SIZE = 8;
 
-        // User Agent constants
-        internal const byte SUPPORTED_USER_AGENT_VERSION = 0x01;
-
         // TCE Related constants
         internal const byte MAX_SUPPORTED_TCE_VERSION = 0x03; // max version
         internal const byte MIN_TCE_VERSION_WITH_ENCLAVE_SUPPORT = 0x02; // min version with enclave support

src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/TdsParser.cs

@@ -18,13 +18,13 @@
 using System.Xml;
 using Interop.Common.Sni;
 using Microsoft.Data.Common;
+using Microsoft.Data.Common.ConnectionString;
 using Microsoft.Data.ProviderBase;
 using Microsoft.Data.Sql;
 using Microsoft.Data.SqlClient.Connection;
 using Microsoft.Data.SqlClient.DataClassification;
 using Microsoft.Data.SqlClient.LocalDb;
 using Microsoft.Data.SqlClient.Server;
-using Microsoft.Data.SqlClient.UserAgent;
 using Microsoft.Data.SqlClient.Utilities;
 using Microsoft.SqlServer.Server;
 
@@ -1305,11 +1305,11 @@ internal void TdsLogin(
             // length in bytes
             int length = TdsEnums.SQL2005_LOG_REC_FIXED_LEN;
 
-            string clientInterfaceName = TdsEnums.SQL_PROVIDER_NAME;
-            Debug.Assert(TdsEnums.MAXLEN_CLIENTINTERFACE >= clientInterfaceName.Length, "cchCltIntName can specify at most 128 unicode characters. See Tds spec");
+            // Obtain the client interface name.
+            string clientInterfaceName = DbConnectionStringDefaults.ApplicationName;
+            Debug.Assert(clientInterfaceName.Length <= TdsEnums.MAXLEN_CLIENTINTERFACE);
 
             // add up variable-len portions (multiply by 2 for byte len of char strings)
-            //
             checked
             {
                 length += (rec.hostName.Length + rec.applicationName.Length +
@@ -1364,7 +1364,7 @@ internal void TdsLogin(
                     requestedFeatures, 
                     recoverySessionData, 
                     fedAuthFeatureExtensionData,
-                    UserAgentInfo.UserAgentCachedJsonPayload.ToArray(),
+                    UserAgent.Ucs2Bytes,
                     useFeatureExt, 
                     length
                     );
@@ -9172,43 +9172,41 @@ internal int WriteVectorSupportFeatureRequest(bool write)
         }
 
         /// <summary>
-        /// Writes the User Agent feature request to the physical state object.
-        /// The request includes the feature ID, feature data length, version number and encoded JSON payload.
+        ///   Writes the User Agent feature request to the physical state
+        ///   object.  The request includes the feature ID, feature data length,
+        ///   and UCS-2 little-endian encoded payload.
         /// </summary>
-        /// <param name="userAgentJsonPayload"> Byte array of UTF-8 encoded JSON payload for User Agent</param>
+        /// <remarks>
+        ///   The feature request consists of:
+        ///     - 1 byte for the feature ID.
+        ///     - 4 bytes for the feature data length.
+        ///     - N bytes for the UCS-2 payload
+        /// </remarks>
+        /// <param name="userAgent">
+        ///   UCS-2 little-endian encoded UserAgent payload.
+        /// </param>
         /// <param name="write">
-        /// If true, writes the feature request to the physical state object.
-        /// If false, just calculates the length.
+        ///   If true, writes the feature request to the physical state object.
+        ///   If false, just calculates the length.
         /// </param>
         /// <returns>The length of the feature request in bytes.</returns>
-        /// <remarks>
-        /// The feature request consists of:
-        /// - 1 byte for the feature ID.
-        /// - 4 bytes for the feature data length.
-        /// - 1 byte for the version number.
-        /// - N bytes for the JSON payload
-        /// </remarks>
-        internal int WriteUserAgentFeatureRequest(byte[] userAgentJsonPayload,
+        internal int WriteUserAgentFeatureRequest(ReadOnlyMemory<byte> userAgent,
                                                   bool write)
         {
-            // 1byte (Feature Version) + size of UTF-8 encoded JSON payload 
-            int dataLen = 1 + userAgentJsonPayload.Length;
-            // 1byte (Feature ID) + 4bytes (Feature Data Length) + 1byte (Version) + N(JSON payload size)
-            int totalLen = 1 + 4 + dataLen;
+            // 1 byte (Feature ID) + 4 bytes (Feature Data Length) + N bytes
+            // (UCS-2 payload size)
+            int totalLen = 1 + 4 + userAgent.Length;
 
             if (write)
             {
                 // Write Feature ID
                 _physicalStateObj.WriteByte(TdsEnums.FEATUREEXT_USERAGENT);
 
                 // Feature Data Length
-                WriteInt(dataLen, _physicalStateObj);
-
-                // Write Feature Version
-                _physicalStateObj.WriteByte(TdsEnums.SUPPORTED_USER_AGENT_VERSION);
+                WriteInt(userAgent.Length, _physicalStateObj);
 
-                // Write encoded JSON payload
-                _physicalStateObj.WriteByteArray(userAgentJsonPayload, userAgentJsonPayload.Length, 0);
+                // Write encoded UCS-2 payload
+                _physicalStateObj.WriteByteSpan(userAgent.Span);
             }
 
             return totalLen;
@@ -9488,7 +9486,7 @@ private void WriteLoginData(SqlLogin rec,
                     requestedFeatures,
                     recoverySessionData,
                     fedAuthFeatureExtensionData,
-                    UserAgentInfo.UserAgentCachedJsonPayload.ToArray(),
+                    UserAgent.Ucs2Bytes,
                     useFeatureExt,
                     length,
                     true
@@ -9511,7 +9509,7 @@ private void WriteLoginData(SqlLogin rec,
         private int ApplyFeatureExData(TdsEnums.FeatureExtension requestedFeatures,
                                        SessionData recoverySessionData,
                                        FederatedAuthenticationFeatureExtensionData fedAuthFeatureExtensionData,
-                                       byte[] userAgentJsonPayload,
+                                       ReadOnlyMemory<byte> userAgent,
                                        bool useFeatureExt,
                                        int length,
                                        bool write = false)
@@ -9523,7 +9521,7 @@ private int ApplyFeatureExData(TdsEnums.FeatureExtension requestedFeatures,
                     // NOTE: As part of TDS spec UserAgent feature extension should be the first feature extension in the list.
                     if (LocalAppContextSwitches.EnableUserAgent && ((requestedFeatures & TdsEnums.FeatureExtension.UserAgent) != 0))
                     {
-                        length += WriteUserAgentFeatureRequest(userAgentJsonPayload, write);
+                        length += WriteUserAgentFeatureRequest(userAgent, write);
                     }
                     if ((requestedFeatures & TdsEnums.FeatureExtension.SessionRecovery) != 0)
                     {