Send user agent info as a new feature extension to server (#2793)

* POC change to send user agent via feature ext.

* Change FE identifier and encoding to UCS16

* Removed ApplicationAttributes logic

* Changed sanitizing logic to not replace non-ascii chars

* Send user agent FE as the first FE

* Removed trailing $1 from the string template

* Removed commented code

* Removed unused constant

Author: machavan

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

@@ -178,6 +178,9 @@ 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 byte MAX_USERAGENT_VERSION = 0x01;
 
     static final int TDS_TVP = 0xF3;
     static final int TVP_ROW = 0x01;
@@ -251,7 +254,9 @@ 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 +313,72 @@ public String toString() {
      **/
     private static final Lock sLock = new ReentrantLock();
 
+    static final String USER_AGENT_TEMPLATE = "{\"driver\":\"%s\",\"version\":\"%s\",\"os\":{\"type\":\"%s\",\"details\":\"%s\"},\"arch\":\"%s\",\"runtime\":\"%s\"}";
+    static final String userAgentStr;
+
+    static {
+        userAgentStr = getUserAgent();
+    }
+
+    static String getUserAgent() {
+        try {
+            return String.format(
+                    USER_AGENT_TEMPLATE,
+                    "MS-JDBC",
+                    getJDBCVersion(),
+                    getOSType(),
+                    getOSDetails(),
+                    getArchitecture(),
+                    getRuntimeDetails()
+                    );
+        } catch(Exception e) {
+            return "{\"driver\":\"MS-JDBC\"}";
+        }
+    }
+
+    static String getJDBCVersion() {
+        return sanitizeField(SQLJdbcVersion.MAJOR + "." + SQLJdbcVersion.MINOR + "." + SQLJdbcVersion.PATCH + "." + SQLJdbcVersion.BUILD + SQLJdbcVersion.RELEASE_EXT, 16);
+    }
+
+    static String getOSType() {
+        String osName = System.getProperty("os.name", "Unknown").trim();
+        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, 16);
+    }
+
+    static String getArchitecture() {
+        return sanitizeField(System.getProperty("os.arch", "Unknown").trim(), 16);
+    }
+
+    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, 128);
+    }
+
+    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, 128);
+    }
+
+    static String sanitizeField(String field, int maxLength) {
+        return (field == null || field.isEmpty()) ? "Unknown" : field.substring(0, Math.min(field.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.
@@ -5685,6 +5751,28 @@ 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 + 6; // 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 + 1);
+            tdsWriter.writeByte(TDS.MAX_USERAGENT_VERSION);
+            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,
@@ -6903,6 +6991,14 @@ 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);
@@ -7190,6 +7286,9 @@ 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) {
@@ -7394,6 +7493,8 @@ final boolean complete(LogonCommand logonCommand, TDSReader tdsReader) throws SQ
             tdsWriter.writeBytes(secBlob, 0, secBlob.length);
         }
 
+        writeUserAgentFeatureRequest(true, tdsWriter);
+
         // AE is always ON
         writeAEFeatureRequest(true, tdsWriter);