Send user agent info as a new feature extension to server

src/main/java/com/microsoft/sqlserver/jdbc/IOBuffer.java

@@ -178,6 +178,8 @@ final class TDS {
     static final byte TDS_FEATURE_EXT_JSONSUPPORT = 0x0D;
     static final byte JSONSUPPORT_NOT_SUPPORTED = 0x00;
     static final byte MAX_JSONSUPPORT_VERSION = 0x01;
+    // User agent telemetry support
+    static final byte TDS_FEATURE_EXT_USERAGENT = 0x10;
 
     static final int TDS_TVP = 0xF3;
     static final int TVP_ROW = 0x01;
@@ -251,7 +253,9 @@ static final String getTokenName(int tdsTokenType) {
                 return "TDS_FEATURE_EXT_VECTORSUPPORT (0x0E)";
             case TDS_FEATURE_EXT_JSONSUPPORT:
                 return "TDS_FEATURE_EXT_JSONSUPPORT (0x0D)";
-
+            case TDS_FEATURE_EXT_USERAGENT:
+                return "TDS_FEATURE_EXT_USERAGENT (0x10)";
+
             default:
                 return "unknown token (0x" + Integer.toHexString(tdsTokenType).toUpperCase() + ")";
         }

src/main/java/com/microsoft/sqlserver/jdbc/SQLServerConnection.java

@@ -313,6 +313,79 @@ public String toString() {
      **/
     private static final Lock sLock = new ReentrantLock();
 
+    static final String USER_AGENT_TEMPLATE = "%s|%s|%s|%s|%s|%s|%s";
+    static final String USER_AGENT_EXT_VERSION_AND_DRIVER_NAME = "1|MS-JDBC";
+    static final String userAgentStr;
+
+    static {
+        userAgentStr = getUserAgent();
+    }
+
+    static String getUserAgent() {
+        try {
+            return String.format(
+                    USER_AGENT_TEMPLATE,
+                    "1",
+                    "MS-JDBC",
+                    getJDBCVersion(),
+                    getOSType(),
+                    getOSDetails(),
+                    getArchitecture(),
+                    getRuntimeDetails()
+                    );
+        } catch(Exception e) {
+            return USER_AGENT_EXT_VERSION_AND_DRIVER_NAME;
+        }
+    }
+
+    static String getJDBCVersion() {
+        return sanitizeField(SQLJdbcVersion.MAJOR + "." + SQLJdbcVersion.MINOR + "." + SQLJdbcVersion.PATCH + "." + SQLJdbcVersion.BUILD + SQLJdbcVersion.RELEASE_EXT, 24);
+    }
+
+    static String getOSType() {
+        String osName = System.getProperty("os.name", "Unknown").trim().toLowerCase();
+        String osNameToReturn = "Unknown";
+        if (osName.startsWith("windows")) {
+            osNameToReturn = "Windows";
+        } else if (osName.startsWith("linux")) {
+            osNameToReturn = "Linux";
+        } else if (osName.startsWith("mac")) {
+            osNameToReturn = "macOS";
+        } else if (osName.startsWith("freebsd")) {
+            osNameToReturn = "FreeBSD";
+        } else if (osName.startsWith("android")) {
+            osNameToReturn = "Android";
+        }
+        return sanitizeField(osNameToReturn, 10);
+    }
+
+    static String getArchitecture() {
+        return sanitizeField(System.getProperty("os.arch", "Unknown").trim(), 10);
+    }
+
+    static String getOSDetails() {
+        String osName = System.getProperty("os.name", "").trim();
+        String osVersion = System.getProperty("os.version", "").trim();
+        if (osName.isEmpty() && osVersion.isEmpty()) {
+            return "Unknown";
+        }
+        return sanitizeField(osName + " " + osVersion, 44);
+    }
+
+    static String getRuntimeDetails() {
+        String javaVmName = System.getProperty("java.vm.name", "").trim();
+        String javaVmVersion = System.getProperty("java.vm.version", "").trim();
+        if (javaVmName.isEmpty() && javaVmVersion.isEmpty()) {
+            return "Unknown";
+        }
+        return sanitizeField(javaVmName + " " + javaVmVersion, 44);
+    }
+
+    static String sanitizeField(String field, int maxLength) {
+        String sanitized = field.replaceAll("[^A-Za-z0-9 .+_-]", "").trim();
+        return (sanitized == null || sanitized.isEmpty()) ? "Unknown" : sanitized.substring(0, Math.min(sanitized.length(), maxLength));
+    }
+
     /**
      * Generate a 6 byte random array for netAddress
      * As per TDS spec this is a unique clientID (MAC address) used to identify the client.
@@ -5789,6 +5862,27 @@ int writeDNSCacheFeatureRequest(boolean write, /* if false just calculates the l
         return len;
     }
 
+    /**
+     * Writes the user agent telemetry feature request 
+     * @param write
+     * If true, writes the feature request to the physical state object.
+     * @param tdsWriter
+     * @return
+     * The length of the feature request in bytes, or 0 if vectorTypeSupport is "off".
+     * @throws SQLServerException
+     */
+    int writeUserAgentFeatureRequest(boolean write, /* if false just calculates the length */
+            TDSWriter tdsWriter) throws SQLServerException {
+        byte[] userAgentToSendBytes = toUCS16(userAgentStr);
+        int len = userAgentToSendBytes.length + 5; // 1byte = featureID, 1byte = version, 4byte = feature data length in bytes, remaining bytes: feature data
+        if (write) {
+            tdsWriter.writeByte(TDS.TDS_FEATURE_EXT_USERAGENT);
+            tdsWriter.writeInt(userAgentToSendBytes.length);
+            tdsWriter.writeBytes(userAgentToSendBytes);
+         }
+	     return len;
+    }
+
     /**
      * Writes the Vector Support feature request to the physical state object,
      * unless vectorTypeSupport is "off". The request includes the feature ID,
@@ -7043,6 +7137,14 @@ private void onFeatureExtAck(byte featureId, byte[] data) throws SQLServerExcept
                 break;
             }
 
+            case TDS.TDS_FEATURE_EXT_USERAGENT: {
+                if (connectionlogger.isLoggable(Level.FINER)) {
+                    connectionlogger.fine(
+                            toString() + " Received feature extension acknowledgement for User agent feature extension. Received byte: " + data[0]);
+                }
+                break;
+            }
+
             default: {
                 // Unknown feature ack
                 throw new SQLServerException(SQLServerException.getErrString("R_UnknownFeatureAck"), null);
@@ -7330,6 +7432,9 @@ final boolean complete(LogonCommand logonCommand, TDSReader tdsReader) throws SQ
         }
 
         int aeOffset = len;
+
+        len += writeUserAgentFeatureRequest(false, tdsWriter);
+
         // AE is always ON
         len += writeAEFeatureRequest(false, tdsWriter);
         if (federatedAuthenticationInfoRequested || federatedAuthenticationRequested) {
@@ -7534,6 +7639,9 @@ final boolean complete(LogonCommand logonCommand, TDSReader tdsReader) throws SQ
             tdsWriter.writeBytes(secBlob, 0, secBlob.length);
         }
 
+        //Write user agent string
+        writeUserAgentFeatureRequest(true, tdsWriter);
+
         // AE is always ON
         writeAEFeatureRequest(true, tdsWriter);
 

src/test/java/com/microsoft/sqlserver/jdbc/SQLServerDriverTest.java

@@ -5,6 +5,7 @@
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.Mockito.mockStatic;
 
 import java.sql.Connection;
 import java.sql.Driver;
@@ -22,6 +23,7 @@
 import org.junit.jupiter.api.Test;
 import org.junit.platform.runner.JUnitPlatform;
 import org.junit.runner.RunWith;
+import org.mockito.MockedStatic;
 
 import com.microsoft.sqlserver.testframework.AbstractTest;
 import com.microsoft.sqlserver.testframework.Constants;
@@ -266,4 +268,44 @@ public void testApplicationName() throws SQLException {
     //     String defaultAppName = SQLServerDriver.getAppName();
     //     assertEquals(SQLServerDriver.DEFAULT_APP_NAME, defaultAppName, "Application name should be the default one");
     // }
+
+    /**
+     * test user agent string length
+     * 
+     * @throws SQLException
+     */    
+    @Test
+    public void testDriverUserAgentLength() throws SQLException {
+        String userAgent = SQLServerConnection.getUserAgent();
+        assertTrue(userAgent.length() <= 256, "User agent string length should not be more than 256 characters"); 
+    }
+
+    /**
+     * test user agent string OS
+     * 
+     * @throws SQLException
+     */    
+    @Test
+    public void testDriverUserAgentOS() throws SQLException {
+        System.setProperty("os.name", "Linux");
+        String userAgent = SQLServerConnection.getUserAgent();
+        assertTrue(userAgent.contains("Linux"), "User agent string must contain Linux");
+
+        System.setProperty("os.name", "Mac");
+        userAgent = SQLServerConnection.getUserAgent();
+        assertTrue(userAgent.contains("macOS"), "User agent string must contain macOS");
+
+        System.setProperty("os.name", "FreeBSD");
+        userAgent = SQLServerConnection.getUserAgent();
+        assertTrue(userAgent.contains("FreeBSD"), "User agent string must contain FreeBSD");
+
+        System.setProperty("os.name", "Android");
+        userAgent = SQLServerConnection.getUserAgent();
+        assertTrue(userAgent.contains("Android"), "User agent string must contain Android");
+
+        System.setProperty("os.name", "Windows");
+        userAgent = SQLServerConnection.getUserAgent();
+        assertTrue(userAgent.contains("Windows"), "User agent string must contain Windows");
+
+    }
 }