NfsAccessRequest.java

/**
 * Copyright 2016-2018 Dell Inc. or its subsidiaries. All rights reserved.
 *
 * <p>Licensed under the Apache License, Version 2.0 (the "License"). You may not use this file
 * except in compliance with the License. A copy of the License is located at
 *
 * <p>http://www.apache.org/licenses/LICENSE-2.0.txt
 *
 * <p>or in the "license" file accompanying this file. This file is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations under the License.
 */
package com.emc.ecs.nfsclient.nfs;

import com.emc.ecs.nfsclient.rpc.Credential;
import com.emc.ecs.nfsclient.rpc.Xdr;
import java.io.FileNotFoundException;

/**
 * The request, as specified by RFC 1813 (https://tools.ietf.org/html/rfc1813).
 *
 * <p>Procedure ACCESS determines the access rights that a user, as identified by the credentials in
 * the request, has with respect to a file system object. The client encodes the set of permissions
 * that are to be checked in a bit mask. The server checks the permissions encoded in the bit mask.
 * A status of NFS3_OK is returned along with a bit mask encoded with the permissions that the
 * client is allowed.
 *
 * <p>The results of this procedure are necessarily advisory in nature. That is, a return status of
 * NFS3_OK and the appropriate bit set in the bit mask does not imply that such access will be
 * allowed to the file system object in the future, as access rights can be revoked by the server at
 * any time.
 *
 * @author seibed
 */
public class NfsAccessRequest extends NfsRequestBase {

  /**
   * A bit mask of access permissions to check, as specified below.
   *
   * <pre>
   * ACCESS3_READ    = 0x0001 - Read data from file or read a directory.
   * ACCESS3_LOOKUP  = 0x0002 - Look up a name in a directory (no meaning for non-directory objects).
   * ACCESS3_MODIFY  = 0x0004 - Rewrite existing file data or modify existing directory entries.
   * ACCESS3_EXTEND  = 0x0008 - Write new data or add directory entries.
   * ACCESS3_DELETE  = 0x0010 - Delete an existing directory entry.
   * ACCESS3_EXECUTE = 0x0020 - Execute file (no meaning for a directory).
   * </pre>
   */
  private final long _accessToCheck;

  /**
   * Creates the request, as specified by RFC 1813 (https://tools.ietf.org/html/rfc1813).
   *
   * <p>Procedure ACCESS determines the access rights that a user, as identified by the credentials
   * in the request, has with respect to a file system object. The client encodes the set of
   * permissions that are to be checked in a bit mask. The server checks the permissions encoded in
   * the bit mask. A status of NFS3_OK is returned along with a bit mask encoded with the
   * permissions that the client is allowed.
   *
   * <p>The results of this procedure are necessarily advisory in nature. That is, a return status
   * of NFS3_OK and the appropriate bit set in the bit mask does not imply that such access will be
   * allowed to the file system object in the future, as access rights can be revoked by the server
   * at any time.
   *
   * @param fileHandle The file handle for the file system object to which access is to be checked.
   * @param accessToCheck A bit mask of access permissions to check, as specified below.
   *     <pre>
   * ACCESS3_READ    = 0x0001 - Read data from file or read a directory.
   * ACCESS3_LOOKUP  = 0x0002 - Look up a name in a directory (no meaning for non-directory objects).
   * ACCESS3_MODIFY  = 0x0004 - Rewrite existing file data or modify existing directory entries.
   * ACCESS3_EXTEND  = 0x0008 - Write new data or add directory entries.
   * ACCESS3_DELETE  = 0x0010 - Delete an existing directory entry.
   * ACCESS3_EXECUTE = 0x0020 - Execute file (no meaning for a directory).
   *            </pre>
   *
   * @param credential The credential used for RPC authentication.
   * @param nfsVersion The NFS version number
   */
  public NfsAccessRequest(
      byte[] fileHandle, long accessToCheck, Credential credential, int nfsVersion)
      throws FileNotFoundException {
    super(Nfs.RPC_PROGRAM, nfsVersion, Nfs.NFSPROC3_ACCESS, credential, fileHandle);
    _accessToCheck = accessToCheck;
  }

  /** {@inheritDoc} */
  @Override
  public void marshalling(Xdr xdr) {
    super.marshalling(xdr);
    xdr.putUnsignedInt(_accessToCheck);
  }

  /** {@inheritDoc} */
  @Override
  public String toString() {
    return startToString("NfsAccessRequest")
        .append(" accessToCheck:")
        .append(String.valueOf(_accessToCheck))
        .toString();
  }
}