# Witness Protocol Feature - Detailed Design Document

## 1. Overview

The SMB Witness Protocol enables rapid notification of resource changes in a clustered file server environment. It provides fast failover capabilities by allowing clients to register for notifications about server node availability, share movement, and other critical cluster events.

## 2. Protocol Specification Reference

- **MS-SWN**: Service Witness Protocol Specification

     *
     * @param protocol the protocol name to add (without colon suffix)
     */
    public void addWebProtocol(final String protocol) {
        final String prefix = protocol + ":";
        if (stream(webProtocols).get(stream -> stream.anyMatch(s -> s.equals(prefix)))) {
            logger.debug("Web protocols already contains: protocol={}", protocol);
            return;
        }

<dependency>
    <groupId>org.codelibs</groupId>
    <artifactId>jcifs</artifactId>
    <version>2.1.39</version>
</dependency>
```



## Features

### Protocol Support
The library supports a full range of SMB protocols with automatic negotiation:

**Supported Protocols:**
- **SMB1/CIFS**: Legacy support via `jcifs.smb1/` package
- **SMB 2.0.2**: Windows Vista+ (0x0202)
- **SMB 2.1**: Windows 7/Server 2008R2 (0x0210)

        synchronized (PROTOCOL_HANDLERS) {
            URLStreamHandler handler = (URLStreamHandler) PROTOCOL_HANDLERS.get(protocol);
            if (handler != null) {
                return handler;
            }
            if (factory != null) {
                handler = factory.createURLStreamHandler(protocol);
            }

        // Test registerSmbURLHandler when java.protocol.handler.pkgs is null
        System.clearProperty("java.protocol.handler.pkgs");
        SingletonContext.registerSmbURLHandler();
        assertEquals("jcifs", System.getProperty("java.protocol.handler.pkgs"));
    }

    @Test
    void testRegisterSmbURLHandlerWhenPkgsDoesNotContainJcifs() {
        // Test registerSmbURLHandler when java.protocol.handler.pkgs does not contain "jcifs"

        if (StringUtil.isNotBlank(value)) {
            return check(protocols, value);
        }
        return true;
    }

    /**
     * Checks if the given value matches any of the specified protocols.
     *
     * @param protocols the allowed protocols
     * @param value the URI string to validate
     * @return true if the value matches allowed protocols, false otherwise
     */

        // Protocol errors
        INVALID_PARAMETER("Invalid parameter", ErrorCategory.PROTOCOL, false), NOT_SUPPORTED("Operation not supported",
                ErrorCategory.PROTOCOL, false), INVALID_PROTOCOL("Invalid protocol", ErrorCategory.PROTOCOL,
                        false), MESSAGE_TOO_LARGE("Message too large", ErrorCategory.PROTOCOL, false),

        // Resource errors

    // Getters and setters

    /**
     * Get the minimum SMB Direct protocol version
     *
     * @return minimum protocol version
     */
    public int getMinVersion() {
        return minVersion;
    }

    /**
     * Set the minimum SMB Direct protocol version
     *
     * @param minVersion minimum protocol version
     */
    public void setMinVersion(int minVersion) {

        final Smb2TransformHeader header = new Smb2TransformHeader();

        // Check protocol ID
        final int protocolId = SMBUtil.readInt4(buffer, bufferIndex);
        if (protocolId != TRANSFORM_PROTOCOL_ID) {
            throw new IllegalArgumentException("Invalid transform header protocol ID: 0x" + Integer.toHexString(protocolId));
        }
        bufferIndex += 4;

        // Read signature

        handlers.clear();
    }

    /**
     * Pre-populates the protocol handlers cache with mock handlers for testing.
     * This avoids the need for actual protocol handlers to be available.
     */
    private void setupMockProtocolHandlers() throws Exception {
        Field handlersField = Handler.class.getDeclaredField("PROTOCOL_HANDLERS");
        handlersField.setAccessible(true);