/*
* RHQ Management Platform
* Copyright (C) 2005-2008 Red Hat, Inc.
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
package org.rhq.plugins.www.snmp;
import java.io.InputStream;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.Collection;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.snmp4j.smi.OID;
public class SNMPClient {
static final int AUTH_MD5 = 0;
static final int AUTH_SHA = 1;
public static final String DEFAULT_HOST = "127.0.0.1";
public static final int DEFAULT_PORT = 161;
public static final String DEFAULT_COMMUNITY = "public";
public static final String DEFAULT_USERNAME = "username";
public static final String DEFAULT_PASSWORD = "password";
public static final SNMPVersion DEFAULT_VERSION = SNMPVersion.V2C;
public enum SNMPVersion {
V1,
V2C,
V3
}
public static final String[] VALID_AUTHTYPES = { "md5", "sha" };
private static Log log = LogFactory.getLog(SNMPClient.class);
//XXX cache should be configurable by subclasses
private static int CACHE_EXPIRE_DEFAULT = 60 * 1000; //60 seconds
private static final Map<String, OID> MIB_OID_CACHE = new HashMap<String, OID>();
private static final Map<Integer, SNMPSession> SESSION_CACHE = new HashMap<Integer, SNMPSession>();
private static final Properties OIDS = new Properties();
private int sessionCacheExpire = CACHE_EXPIRE_DEFAULT;
// NOTE: We do *not* use a leading slash, since ClassLoader.getResourceAsStream() does not work if there is a one.
private static final String OIDS_PROPERTIES_RESOURCE_PATH = "org/rhq/plugins/apache/oids.properties";
public SNMPClient() {
if (OIDS.isEmpty()) {
initOids();
}
}
private static int parseAuthMethod(String authMethod) {
if (authMethod == null) {
throw new IllegalArgumentException("authMethod is null");
}
if (authMethod.equalsIgnoreCase("md5")) {
return AUTH_MD5;
} else if (authMethod.equalsIgnoreCase("sha")) {
return AUTH_SHA;
}
throw new IllegalArgumentException("unknown authMethod: " + authMethod);
}
private void initOids() {
ClassLoader contextClassLoader = Thread.currentThread().getContextClassLoader();
ClassLoader classLoader = (contextClassLoader != null) ? contextClassLoader : this.getClass().getClassLoader();
InputStream stream = classLoader.getResourceAsStream(OIDS_PROPERTIES_RESOURCE_PATH);
if (stream == null) {
throw new IllegalStateException("Resource '" + OIDS_PROPERTIES_RESOURCE_PATH + "' not found by "
+ classLoader);
}
Properties props = new Properties();
try {
try {
props.load(stream);
} finally {
stream.close();
}
} catch (Exception e) {
throw new IllegalStateException("Failed to parse oids.properties file from plugin classloader.", e);
}
Enumeration<?> propNames = props.propertyNames();
while (propNames.hasMoreElements()) {
String propName = (String) propNames.nextElement();
OIDS.setProperty(propName, props.getProperty(propName).trim());
}
}
static synchronized OID getMibOID(String mibName) throws MIBLookupException {
if (mibName.charAt(0) == '.') {
// snmp4j doesn't like OIDs with leading dots...
mibName = mibName.substring(1);
}
if (Character.isDigit(mibName.charAt(0))) {
// passed-in string is already in numeric form.
return new OID(mibName);
}
OID oid = MIB_OID_CACHE.get(mibName);
if (oid == null) {
String oidString = OIDS.getProperty(mibName);
if (oidString == null) {
String msg = "Failed to lookup OID for name=" + mibName;
throw new MIBLookupException(msg);
}
oid = new OID(oidString);
if (oid.size() == 0) {
throw new IllegalStateException("Failed to parse OID string [" + oidString
+ "] while mapping MIB name [" + mibName + "].");
}
log.debug("MIB name [" + mibName + "] mapped to OID [" + oid + "].");
MIB_OID_CACHE.put(mibName, oid);
}
return oid;
}
public static String getOID(String mibName) {
try {
return getMibOID(mibName).toString();
} catch (MIBLookupException e) {
return null;
}
}
/**
* Begins a "session" with an SNMP agent.
*
* @param version The version of SNMP to use. Can be one of the following values: VERSION_1, VERSION_2C, VERSION_3
*
* @return A SNMPSession object to be used in all future communications with the SNMP agent.
*
* @throws SNMPException on error
*/
static SNMPSession startSession(SNMPVersion version) throws SNMPException {
switch (version) {
case V1: {
return new SNMPSession_v1();
}
case V2C: {
return new SNMPSession_v2c();
}
case V3: {
return new SNMPSession_v3();
}
default: {
throw new SNMPException("Invalid SNMP Version: " + version);
}
}
}
public boolean init(Properties props) throws SNMPException {
//this is mainly for debugging.
final String prop = "snmp.sessionCacheExpire";
String expire = props.getProperty(prop);
if (expire != null) {
this.sessionCacheExpire = Integer.parseInt(expire) * 1000;
}
return true;
}
public void close() {
synchronized (SESSION_CACHE) {
Collection<SNMPSession> sessions = SESSION_CACHE.values();
for (SNMPSession session : sessions) {
session.close();
}
SESSION_CACHE.clear(); // clean out old sessions after they have been closed.
}
}
public SNMPSession getSession(String host, Integer port, String community, SNMPVersion version, long timeout,
int retries)
throws SNMPException {
SNMPSession session;
if (host == null) {
host = DEFAULT_HOST;
}
if (port == null) {
port = DEFAULT_PORT;
}
if (community == null) {
community = DEFAULT_COMMUNITY;
}
if (version == null) {
version = DEFAULT_VERSION;
}
int id = host.hashCode() ^ port.hashCode() ^ community.hashCode() ^ version.hashCode();
synchronized (SESSION_CACHE) {
session = SESSION_CACHE.get(id);
}
if (session != null) {
return session;
}
InetAddress ip;
try {
ip = InetAddress.getByName(host);
} catch (UnknownHostException e) {
throw new SNMPException("Invalid Host: '" + host + "': " + e);
}
if ((port < 1) || (port > 65535)) {
throw new SNMPException("Invalid Port: " + port);
}
if (!community.trim().equals(community)) {
throw new SNMPException("Invalid Community: '" + community + "': whitespace is not permitted");
}
if (timeout <= 0) {
throw new SNMPException("Invalid Timeout: '" + timeout + "': must be a positive number");
}
if (retries < 0) {
throw new SNMPException("Invalid Retries: '" + timeout + "': must be greater than or equal to 0");
}
try {
session = startSession(version);
switch (version) {
case V1:
case V2C: {
((SNMPSession_v1) session).init(host, port, community, timeout, retries);
break;
}
case V3: {
// TODO
String user = "TODO";
String pass = "TODO";
int authType = parseAuthMethod("TODO");
((SNMPSession_v3) session).init(host, port, user, pass, authType);
break;
}
default: {
throw new SNMPException("unsupported SNMP version");
}
}
log.info("Initialized SNMP session for agent at " + ip + ":" + port + ".");
} catch (SNMPException e) {
throw new SNMPException("Failed to initialize SNMP session for agent at " + ip + ":" + port + ".", e);
}
session = SNMPSessionCache.newInstance(session, this.sessionCacheExpire);
synchronized (SESSION_CACHE) {
SESSION_CACHE.put(id, session);
}
return session;
}
}