import jcifs.internal.smb2.rdma.RdmaCapability;
import jcifs.internal.smb2.rdma.RdmaConnection;
import jcifs.internal.smb2.rdma.RdmaMemoryRegion;
import jcifs.internal.smb2.rdma.RdmaProvider;

/**
 * TCP fallback RDMA provider.
 *
 * This provider uses regular TCP connections but maintains the RDMA
 * interface for compatibility. It only supports send/receive operations
 * and does not provide true RDMA read/write capabilities.
 */

        // TCP fallback doesn't support real RDMA read
        throw new UnsupportedOperationException("RDMA read not supported by TCP fallback");
    }

    @Override
    public void rdmaWrite(RdmaMemoryRegion localRegion, long remoteAddress, int remoteKey, int length) throws IOException {
        // TCP fallback doesn't support real RDMA write

    /**
     * Query string parameter for error page fallback.
     * Contains the original search query if redirection fails.
     */
    public String q;

    /**
     * Number of results parameter for error page fallback.
     * Specifies how many results to display if redirection fails.
     */
    public String num;

    /**
     * Sort parameter for error page fallback.
     * Defines the sorting order if redirection fails.

        assertFalse(providers.isEmpty(), "Should have at least one available provider");
        assertTrue(providers.contains("TCP Fallback"), "Should include TCP fallback");
    }

import java.util.EnumSet;
import java.util.Set;

/**
 * Interface for RDMA provider implementations.
 *
 * This interface abstracts different RDMA implementations such as
 * InfiniBand, iWARP, RoCE, or TCP fallback providers.
 */
public interface RdmaProvider {

    /**
     * Check if RDMA is available on this system
     *
     * @return true if RDMA can be used, false otherwise
     */
    boolean isAvailable();

import java.util.concurrent.atomic.AtomicInteger;

import jcifs.internal.smb2.rdma.RdmaAccess;
import jcifs.internal.smb2.rdma.RdmaMemoryRegion;

/**
 * TCP memory region implementation.
 *
 * For TCP fallback, memory regions are just wrappers around
 * ByteBuffers since no real RDMA registration is needed.
 */
public class TcpMemoryRegion extends RdmaMemoryRegion {

        // Try providers in order of preference
        List<RdmaProvider> providers = Arrays.asList(new DisniRdmaProvider(), // InfiniBand/RoCE - highest performance
                new TcpRdmaProvider() // TCP fallback - always available
        );

        for (RdmaProvider provider : providers) {
            if (provider.isAvailable()) {
                log.info("Selected RDMA provider: {}", provider.getProviderName());

        assertNotNull(firstName, "First called name should not be null");
    }

    @Test
    @DisplayName("nextCalledName should return valid name for fallback attempts")
    void testNextCalledNameContract() {
        // Given
        String expectedNextName = "SERVER15";
        when(mockAddress.nextCalledName(mockContext)).thenReturn(expectedNextName);

        // When

        // Test cleanup
        region.close();
        assertFalse(region.isValid(), "Region should be invalid after close");
    }

    @Test
    public void testGetProviderName() {
        assertEquals("TCP Fallback", provider.getProviderName());
    }

    @Test
    public void testGetMaxMessageSize() {
        assertEquals(65536, provider.getMaxMessageSize(), "TCP provider should have 64KB limit");
    }

    @Test

            // Positive values not in DOS_ERROR_CODES map to NT_STATUS_UNSUCCESSFUL
            expected = NtStatus.NT_STATUS_UNSUCCESSFUL;
        }
        assertEquals(expected, ex.getNtStatus(), "Status should match mapping or fallback");
    }

    /**
     * Verify that root causes are stored and returned correctly.
     */
    @Test
    @DisplayName("Root cause propagation")
    void testRootCausePropagation() {