/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at
 * trunk/opends/resource/legal-notices/OpenDS.LICENSE
 * or https://OpenDS.dev.java.net/OpenDS.LICENSE.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at
 * trunk/opends/resource/legal-notices/OpenDS.LICENSE.  If applicable,
 * add the following below this CDDL HEADER, with the fields enclosed
 * by brackets "[]" replaced with your own identifying information:
 *      Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 *
 *
 *      Copyright 2008 Sun Microsystems, Inc.
 */

// OpenDS imports
import org.opends.server.snmp.DIRECTORY_SERVER_MIBOidTable;

// OpenDMK imports
//
import com.sun.management.snmp.SnmpDefinitions;
import com.sun.management.snmp.SnmpVarBindList;
import com.sun.management.snmp.SnmpEngine;
import com.sun.management.snmp.SnmpEngineParameters;
import com.sun.management.snmp.SnmpOid;
import com.sun.management.snmp.SnmpOidTableSupport;
import com.sun.management.snmp.SnmpStatusException;
import com.sun.management.snmp.manager.SnmpRequest;
import com.sun.management.snmp.manager.SnmpSession;
import com.sun.management.snmp.manager.SnmpPeer;
import com.sun.management.snmp.manager.SnmpParameters;
import com.sun.management.snmp.manager.usm.SnmpUsmPeer;
import com.sun.management.snmp.manager.usm.SnmpUsmParameters;

/**
 * This class perform a SNMP get operation.
 */
public class SNMPGet {

  /**
   * Gets the calling arguments.
   *
   * @param args SNMP version + SNMP agent host + SNMP agent port + community
   * @return 0 if the init succeeded or 1 if the init failed
   */
  public int init(String[] args) {
    int rc = 0;

    System.out.println("\n");

    if (args.length < 5) {
      // Missing arguments
      System.out.println(
              "usage: " +
              " -v <SNMP version>" +
              " -h <remoteHost>" +
              " -p <port>" +
              " -o <oids>" +
              " -c <community/context>" +
              " -u <user>" +
              " -l <securityLevel>" +
              " -f <securityFile>" +
              " -s <connectionStatus>" +
              " -n <checkOIDs>" +
              " -w <snmpwalk>");
      rc = 1;
    } else {
      for (int i = 0; i < args.length; i++) {
        String opt = args[i];
        String val = args[i + 1];

        switch (opt.charAt(1)) {
          case 'v':
            version = new Integer(val).intValue();
            break;
          case 'h':
            remoteHost = val;
            break;
          case 'p':
            port = new Integer(val).intValue();
            break;
          case 'o':
            oids = val;
            break;
          case 'c':
            community = val;
            break;
          case 'u':
            user = val;
            break;
          case 'l':
            if (val.compareTo("noauthnopriv") == 0) {
              securityLevel = SnmpDefinitions.noAuthNoPriv;
            } else if (val.compareTo("authnopriv") == 0) {
              securityLevel = SnmpDefinitions.authNoPriv;
            } else if (val.compareTo("authpriv") == 0) {
              securityLevel = SnmpDefinitions.authPriv;
            } else {
              System.out.println(
                      "Unknown security level " + opt.charAt(1) + ".");
              rc = 1;
            }
            break;
          case 'f':
            securityFile = val;
            break;
          case 's':
            connectStatus = val;
            break;
          case 'n':
            validOIDs = new Boolean(val).booleanValue();
            break;
          case 'w':
            walk = new Boolean(val).booleanValue();
            break;
          default:
            System.out.println("Unknown option -" + opt.charAt(1) + ".");
            rc = 1;
        }

        if (rc == 1) {
          break;
        }

        i = i + 1;
      }
    }

    if (rc == 0) {
      System.out.println("init() of SNMPGet succeeded");
    } else {
      System.out.println("init() of SNMPGet failed");
    }

    return rc;
  }

  /**
   * Open SNMP connection with SNMP agent.
   *
   * @return 0 if the connect succeeded or 1 if the connect failed
   */
  public int connect() {
    int rc = 0;

    try {
      // The OidTable generated by mibgen when compiling DIRECTORY_SERVER_MIB
      //
      final SnmpOidTableSupport oidTable = new DIRECTORY_SERVER_MIBOidTable();

      // Specify the OidTable containing all the DIRECTORY_SERVER_MIB knowledge
      //
      SnmpOid.setSnmpOidTable(oidTable);

      switch (version) {
        case 1:
        case 2:
          // Create the session
          //
          session = new SnmpSession("Get V" + version + " session");

          // Disable PduFixedOnError option
          //
          session.snmpOptions.setPduFixedOnError(false);

          // Create an SnmpPeer object for representing the entity
          // to communicate with.
          //
          final SnmpPeer agent = new SnmpPeer(remoteHost, port);

          // Specify the read and write community to be used
          //
          final SnmpParameters params = new SnmpParameters(
                  community,
                  community);

          // Specify the protocol version
          //
          switch (version) {
            case 1:
              params.setProtocolVersion(SnmpDefinitions.snmpVersionOne);
              break;
            case 2:
              params.setProtocolVersion(SnmpDefinitions.snmpVersionTwo);
              break;
          }

          // Associate the parameters with the agent
          //
          agent.setTimeout(timeOut);
          agent.setMaxTries(maxRetries);
          agent.setParams(params);

          // Set the default peer (agent) to a SnmpSession
          //
          session.setDefaultPeer(agent);
          break;
        case 3:
          // Custom engine parameters
          final SnmpEngineParameters engineParameters =
                  new SnmpEngineParameters();

          // Activate encryption
          engineParameters.activateEncryption();

          // Set the security file
          engineParameters.setSecurityFile(securityFile);

          // Create the session
          //
          session = new SnmpSession(
                  engineParameters,
                  null,
                  "Get V3 session",
                  null);

          // SNMP V3 introduces the notion of SnmpEngine. An engine is
          // associated to the session. Other objects  might need
          // the engine. You can access it using getEngine method.
          //
          final SnmpEngine engine = session.getEngine();

          // Create an SnmpUsmPeer object for representing the entity
          // to communicate with
          //
          final SnmpUsmPeer agentV3 = new SnmpUsmPeer(engine, remoteHost, port);

          // Create USM parameters for the principal defaultuser (user used when
          // requests are sent: the defaultUser is a template and for this
          // reason we cannot find it under the user mib (not created as a user)
          //
          final SnmpUsmParameters paramsV3 = new SnmpUsmParameters(
                  engine,
                  user);

          // Set the security level authentication but without privacy
          //
          paramsV3.setSecurityLevel(securityLevel);

          // Set the context name
          //
          if (community.compareTo("null") != 0) {
            paramsV3.setContextName(community.getBytes());
          }

          // Set the contextEngineId discovered by the peer upon
          // its creation
          //
          paramsV3.setContextEngineId(agentV3.getEngineId().getBytes());

          // Associate the parameters with the agent
          //
          agentV3.setTimeout(timeOut);
          agentV3.setMaxTries(maxRetries);
          agentV3.setParams(paramsV3);

          if (securityLevel != SnmpDefinitions.noAuthNoPriv) {
            // Discover timeliness of creation and boot
            //
            try {
              agentV3.processUsmTimelinessDiscovery();
            } catch (SnmpStatusException e) {
              if (connectStatus.compareTo("SnmpStatusException") == 0) {
                System.out.println(
                        "connect() of SNMPGet catched as expected a " +
                        "SNMP status exception: " + e.getMessage() + "\"");
              } else {
                System.out.println(
                        "connect() of SNMPGet should not catch a " +
                        "SNMP status exception: " + e.getMessage() + "\"");
                
                rc = 1;
              }
            } catch (Exception e) {
              System.out.println(
                      "connect() of SNMPGet catched an unexpected exception: " +
                      e.getMessage() + "\"");

              rc = 1;
            }
          }
          
          if (rc == 0) {
            // Set the default peer (agent) to a SnmpSession
            //
            session.setDefaultPeer(agentV3);
          }
          break;
        default:
          System.out.println(
                  "connect() of SNMPGet: Unknown SNMP version: " +
                  version + " .");

          rc = 1;
      }
    } catch (Exception e) {
      System.out.println(
              "connect() of SNMPGet catched an unexpected exception: " +
              e.getMessage() + "\"");

      rc = 1;
    }

    if (rc == 0) {
      System.out.println("connect() of SNMPGet succeeded");
    } else {
      System.out.println("connect() of SNMPGet failed");
    }

    return rc;
  }

  /**
   * Perform an SNMP get request on SNMP agent.
   *
   * @return 0 if the getRequest succeeded or 1 if the getRequest failed
   */
  public int getRequest() {
    int rc = 0;
    String previousOID = "";

    try {
      // Build the list of variables you want to query
      //
      final SnmpVarBindList list = new SnmpVarBindList("Get varbind list");

      // Read specific OIDs
      //
      if (walk) {
        // Walk request
        //
         list.addVarBind("0.0");
         previousOID = "0.0";
      } else {
        // Get request
        //
        list.addVarBind(oids);
      }

      // Make the SNMP get request
      //
      System.out.println(
              "getRequest() of SNMPGet: Start SNMP V" + version +
              " GET request for SNMP agent on \"" + remoteHost +
              "\" at port \"" + port + "\".");

      while (previousOID.compareTo("end") != 0) {
        SnmpRequest request = null;
        if (walk) {
          // Walk request
          //
          request = session.snmpGetNextRequest(null, list);
        } else {
          // Get request
          //
          request = session.snmpGetRequest(null, list);
        }

        // Check for a timeout of the request
        //
        boolean completed =
                request.waitForCompletion((maxRetries + 1) * timeOut);
        if (completed == false) {
          if (connectStatus.compareTo("reqTimeout") != 0) {
            System.out.println(
                    "getRequest() of SNMPGet: Request timed out, " +
                    "check reachability of agent.");

            // Print request
            //
            System.out.println(
                    "getRequest() of SNMPGet: Request= " +
                    request.toString() + ".");

            rc = 1;
          } else {
            System.out.println(
                    "getRequest() of SNMPGet: Request timed out as expected.");
          }
        }

        if (rc == 0 && completed) {
          System.out.println(
                  "getRequest() of SNMPGet: Finish SNMP V" +
                  version + " GET request.");

          // Now we have a response. Check if the response contains an error
          //
          String errorStatus = SnmpRequest.snmpErrorToString(
                  request.getErrorStatus());
          if (errorStatus.compareTo("noError") != 0) {
            System.out.println(
                    "getRequest() of SNMPGet: Error status= " +
                    errorStatus + ".");

            System.out.println(
                    "getRequest() of SNMPGet: Error index= " +
                    request.getErrorIndex() + ".");

            if (errorStatus.compareTo(connectStatus) == 0) {
              System.out.println(
                      "getRequest() of SNMPGet: Get request failed as " +
                      "expected with " + connectStatus + " status.");
            } else {
              if (walk && errorStatus.compareTo("noSuchName") == 0) {
                System.out.println(
                        "getRequest() of SNMPGet: Get request failed as " +
                        "expected with " + connectStatus + " status.");
              } else {
                System.out.println(
                        "getRequest() of SNMPGet: Get request should " +
                        "fail with " + connectStatus + " status.");

                rc = 1;
              }
            }

            previousOID = "end";
          } else {
            // Now we shall display the content of the result
            //
            SnmpVarBindList resp = request.getResponseVarBindList();

            System.out.println("getRequest() of SNMPGet: Result=");

            String tmpOID = "";
            String realOID = "";
            for (int i = 0; i < resp.getVarBindCount(); i++) {
              tmpOID = resp.getVarBindAt(i).getOid().toString();
              int endIndex = tmpOID.lastIndexOf(".");
              String indexOID = tmpOID.substring(endIndex, tmpOID.length());

              realOID = tmpOID.substring(0, endIndex);
              if (realOID.startsWith("1.3.6.1.2.1.66.2")) {
                endIndex = realOID.lastIndexOf(".");
                realOID = realOID.substring(0, endIndex);
              }

              String name = resp.getVarBindAt(i).resolveVarName(realOID).getName();
              String value = resp.getVarBindAt(i).getStringValue();
              System.out.println(name + indexOID + "=" + value);

              if (walk) {
                list.removeVarBind(previousOID);
                list.addVarBind(tmpOID);
                previousOID = tmpOID;
              } else {
                previousOID = "end";
              }
            }

            if (connectStatus.compareTo("noError") != 0) {
              // Request should failed
              //
              System.out.println(
                      "getRequest() of SNMPGet: Get request should " +
                      "fail with " + connectStatus + " status.");

              rc = 1;
            } else {
              if (validOIDs) {
                // Check that we obtain correct values for the OIDs
                //
                if (resp.checkForValidValues()) {
                  System.out.println(
                          "getRequest() of SNMPGet: Returned values for" +
                          " OIDs are correct.");
                } else {
                  System.out.println(
                          "getRequest() of SNMPGet: Returned values for" +
                          " OIDs are not correct.");

                  rc = 1;
                }
              } else {
                // Check that we obtain incorrect values for the OIDs
                //
                if (resp.checkForValidValues()) {
                  System.out.println(
                          "getRequest() of SNMPGet: Returned values for" +
                          " OIDs should not be correct.");

                  rc = 1;
                } else {
                  System.out.println(
                          "getRequest() of SNMPGet: Returned values for" +
                          " OIDs are not correct as expected.");
                }
              }
            }
          }
        }
      }
    } catch (Exception e) {
      System.out.println(
              "connect() of SNMPGet catched an unexpected exception: " +
              e.getMessage() + "\"");

      rc = 1;
    }

    if (rc == 0) {
      System.out.println("getRequest() of SNMPGet succeeded");
    } else {
      System.out.println("getRequest() of SNMPGet failed");
    }

    return rc;
  }

  /**
   * Close SNMP connection with SNMP agent.
   */
  public void disconnect() {

    // Stop and destroy the SnmpSession if still there
    try {
      session.destroySession();
      session = null;
    } catch (Exception e) {
    // possible session already ended
    }

    System.out.println("disconnect() of SNMPGet succeeded");
  }

  /**
   * Main.
   *
   * @param args arguments
   */
  public static void main(String[] args) {

    SNMPGet client = new SNMPGet();

    int rc = 0;

    // Retrieve parameters
    rc = client.init(args);

    // If init() succeeded then open connection
    if (rc == 0) {
      rc = client.connect();
    }

    // If connect() succeeded then perform get request
    if (rc == 0 && connectStatus.compareTo("SnmpStatusException") != 0) {
      rc = client.getRequest();
    }

    // Close connection
    client.disconnect();

    System.exit(rc);
  }

  // Arguments
  int version = 0;
  String remoteHost = null;
  int port = 0;
  String oids = null;
  String community = null;
  String user = null;
  int securityLevel = SnmpDefinitions.authNoPriv;
  String securityFile = null;
  static String connectStatus = null;
  boolean validOIDs = true;
  boolean walk = false;

  // SnmpSession
  SnmpSession session = null;
  int timeOut = 30000;  // default value
  int maxRetries = 1;
}