對於SNMPv3,不同點有
1) 需要創建USM對象並添加User,
關於USM->http://blog.csdn.net/fw0124/article/details/8557029
2) 需要創建UserTarget對象,而不是創建CommunityTarget對象。
3) 需要創建ScopedPDU對象,而不是PDU對象。
使用SNMP4J進行SNMPv3編程的步驟如下:
1) 創建Snmp對象snmp
2) 創建USM對象,並創建User,添加到USM對象中。
創建User是需要指定securityName,認證協議MD5/SHA1,認證密鑰,加密算法DES/AES,加密密鑰。
添加User到USM對象中時候,可以指定engineID也可以不指定。
3) 創建UserTarget對象target,並指定version, address, timeout, retry等參數,這些和SNMPv1/v2相同。
另外還必須指定SNMPv3特有的兩個參數SecurityLevel和SecurityName。
SNMP4J會根據這個SecurityName到USM的UserTable中查找匹配的User,用這個User的信息進行認證加密處理。
查找的時候必須同時匹配SecurityName和engineID,但是如果添加User到USM對象中時候,沒有指定engineID,那麼SecurityName相同即匹配成功。
4) 創建ScopedPDU對象pdu,並指定操作類型(GET/GETNEXT/GETBULK/SET), 添加VariableBinding(也就是待操作的OID),
如果是GETBULK操作,還可以指定MaxRepetitions和NonRepeaters。
注意一定要指定MaxRepetitions,默認值是0,那樣不會返回任何結果。
如果agent上設定的contextEngineId和snmpEngineId不一致,那麼需要調用ScopedPDU.setContextEngineID()方法設定contextEngineId。
如果agent上設定了contextName,那麼需要調用ScopedPDU.setContextName()方法設定contextName。
5) 調用snmp.send(pdu, target)方法,發送請求請返回結果。
對於SNMPv3,仍然可以調用TableUtils類實現一個SNMP Walk的功能。
但是如果需要指定contextEngineId和contextName, 那麼不能使用DefaultPDUFactory,可以從它繼承並覆蓋它的createPDU方法。
異步的send方法支持和SNMPv1/v2類似。
下面的代碼實例實現了GET, Walk操作, 其他GETNEXT, GETBULK, SET操作類似。
import java.io.IOException;
import java.util.List;
import java.util.Vector;
import org.snmp4j.PDU;
import org.snmp4j.ScopedPDU;
import org.snmp4j.Snmp;
import org.snmp4j.Target;
import org.snmp4j.UserTarget;
import org.snmp4j.event.ResponseEvent;
import org.snmp4j.mp.MPv3;
import org.snmp4j.mp.SnmpConstants;
import org.snmp4j.security.AuthMD5;
import org.snmp4j.security.PrivDES;
import org.snmp4j.security.SecurityLevel;
import org.snmp4j.security.SecurityModels;
import org.snmp4j.security.SecurityProtocols;
import org.snmp4j.security.USM;
import org.snmp4j.security.UsmUser;
import org.snmp4j.smi.OID;
import org.snmp4j.smi.OctetString;
import org.snmp4j.smi.UdpAddress;
import org.snmp4j.smi.VariableBinding;
import org.snmp4j.transport.DefaultUdpTransportMapping;
import org.snmp4j.util.DefaultPDUFactory;
import org.snmp4j.util.TableEvent;
import org.snmp4j.util.TableUtils;
public class SNMPv3Test {
public static void main(String[] args) throws IOException, InterruptedException {
Snmp snmp = new Snmp(new DefaultUdpTransportMapping());
USM usm = new USM(SecurityProtocols.getInstance(), new OctetString(MPv3.createLocalEngineID()), 0);
SecurityModels.getInstance().addSecurityModel(usm);
snmp.listen();
// Add User
UsmUser user = new UsmUser(
new OctetString("nmsAdmin"),
AuthMD5.ID, new OctetString("nmsAuthKey"),
PrivDES.ID, new OctetString("nmsPrivKey"));
//If the specified SNMP engine id is specified, this user can only be used with the specified engine ID
//So if it's not correct, will get an error that can't find a user from the user table.
//snmp.getUSM().addUser(new OctetString("nmsAdmin"), new OctetString("0002651100"), user);
snmp.getUSM().addUser(new OctetString("nmsAdmin"), user);
UserTarget target = new UserTarget();
target.setVersion(SnmpConstants.version3);
target.setAddress(new UdpAddress("192.168.0.100/161"));
target.setSecurityLevel(SecurityLevel.AUTH_PRIV);
target.setSecurityName(new OctetString("nmsAdmin"));
target.setTimeout(3000); //3s
target.setRetries(0);
OctetString contextEngineId = new OctetString("0002651100[02]");
sendRequest(snmp, createGetPdu(contextEngineId), target);
snmpWalk(snmp, target, contextEngineId);
}
private static PDU createGetPdu(OctetString contextEngineId) {
ScopedPDU pdu = new ScopedPDU();
pdu.setType(PDU.GET);
pdu.setContextEngineID(contextEngineId); //if not set, will be SNMP engine id
//pdu.setContextName(contextName); //must be same as SNMP agent
pdu.add(new VariableBinding(new OID("1.3.6.1.2.1.1.3.0"))); //sysUpTime
pdu.add(new VariableBinding(new OID("1.3.6.1.2.1.1.5.0"))); //sysName
pdu.add(new VariableBinding(new OID("1.3.6.1.2.1.1.5"))); //expect an no_such_instance error
return pdu;
}
private static void sendRequest(Snmp snmp, PDU pdu, UserTarget target)
throws IOException {
ResponseEvent responseEvent = snmp.send(pdu, target);
PDU response = responseEvent.getResponse();
if (response == null) {
System.out.println("TimeOut...");
} else {
if (response.getErrorStatus() == PDU.noError) {
Vector<? extends VariableBinding> vbs = response.getVariableBindings();
for (VariableBinding vb : vbs) {
System.out.println(vb + " ," + vb.getVariable().getSyntaxString());
}
} else {
System.out.println("Error:" + response.getErrorStatusText());
}
}
}
private static void snmpWalk(Snmp snmp, UserTarget target, OctetString contextEngineId) {
TableUtils utils = new TableUtils(snmp,
new MyDefaultPDUFactory(PDU.GETNEXT, //GETNEXT or GETBULK)
contextEngineId));
utils.setMaxNumRowsPerPDU(5); //only for GETBULK, set max-repetitions, default is 10
OID[] columnOids = new OID[] {
new OID("1.3.6.1.2.1.1.9.1.2"), //sysORID
new OID("1.3.6.1.2.1.1.9.1.3") //sysORDescr
};
// If not null, all returned rows have an index in a range (lowerBoundIndex, upperBoundIndex]
List<TableEvent> l = utils.getTable(target, columnOids, new OID("3"), new OID("10"));
for (TableEvent e : l) {
System.out.println(e);
}
}
private static class MyDefaultPDUFactory extends DefaultPDUFactory {
private OctetString contextEngineId = null;
public MyDefaultPDUFactory(int pduType, OctetString contextEngineId) {
super(pduType);
this.contextEngineId = contextEngineId;
}
@Override
public PDU createPDU(Target target) {
PDU pdu = super.createPDU(target);
if (target.getVersion() == SnmpConstants.version3) {
((ScopedPDU)pdu).setContextEngineID(contextEngineId);
}
return pdu;
}
}
}