/*
* %CopyrightBegin%
*
* Copyright Ericsson AB 2000-2014. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License 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.
*
* %CopyrightEnd%
*/
package com.ericsson.otp.erlang;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.net.InetAddress;
import java.net.UnknownHostException;
/**
* <p>
* Represents an OTP node.
* </p>
*
* <p>
* About nodenames: Erlang nodenames consist of two components, an alivename and a
* hostname separated by '@'. Additionally, there are two nodename formats: short and
* long. Short names are of the form "alive@hostname", while long names are of the form
* "alive@host.fully.qualified.domainname". Erlang has special requirements regarding the
* use of the short and long formats, in particular they cannot be mixed freely in a
* network of communicating nodes, however Jinterface makes no distinction. See the Erlang
* documentation for more information about nodenames.
* </p>
*
* <p>
* The constructors for the AbstractNode classes will create names exactly as you provide
* them as long as the name contains '@'. If the string you provide contains no '@', it
* will be treated as an alivename and the name of the local host will be appended,
* resulting in a shortname. Nodenames longer than 255 characters will be truncated
* without warning.
* </p>
*
* <p>
* Upon initialization, this class attempts to read the file .erlang.cookie in the user's
* home directory, and uses the trimmed first line of the file as the default cookie by
* those constructors lacking a cookie argument. If for any reason the file cannot be
* found or read, the default cookie will be set to the empty string (""). The location of
* a user's home directory is determined using the system property "user.home", which may
* not be automatically set on all platforms.
* </p>
*
* <p>
* Instances of this class cannot be created directly, use one of the subclasses instead.
* </p>
*/
public class AbstractNode implements OtpTransportFactory {
static String localHost = null;
String node;
String host;
String alive;
String cookie;
static String defaultCookie = null;
final OtpTransportFactory transportFactory;
// Node types
static final int NTYPE_R6 = 110; // 'n' post-r5, all nodes
static final int NTYPE_R4_ERLANG = 109; // 'm' Only for source compatibility
static final int NTYPE_R4_HIDDEN = 104; // 'h' Only for source compatibility
// Node capability flags
static final int dFlagPublished = 1;
static final int dFlagAtomCache = 2;
static final int dFlagExtendedReferences = 4;
static final int dFlagDistMonitor = 8;
static final int dFlagFunTags = 0x10;
static final int dFlagDistMonitorName = 0x20; // NOT USED
static final int dFlagHiddenAtomCache = 0x40; // NOT SUPPORTED
static final int dflagNewFunTags = 0x80;
static final int dFlagExtendedPidsPorts = 0x100;
static final int dFlagExportPtrTag = 0x200; // NOT SUPPORTED
static final int dFlagBitBinaries = 0x400;
static final int dFlagNewFloats = 0x800;
static final int dFlagUnicodeIo = 0x1000;
static final int dFlagUtf8Atoms = 0x10000;
static final int dFlagMapTag = 0x20000;
int ntype = NTYPE_R6;
int proto = 0; // tcp/ip
int distHigh = 5; // Cannot talk to nodes before R6
int distLow = 5; // Cannot talk to nodes before R6
int creation = 0;
int flags = dFlagExtendedReferences | dFlagExtendedPidsPorts | dFlagBitBinaries
| dFlagNewFloats | dFlagFunTags | dflagNewFunTags | dFlagUtf8Atoms
| dFlagMapTag;
/* initialize hostname and default cookie */
static {
try {
localHost = InetAddress.getLocalHost().getHostName();
/*
* Make sure it's a short name, i.e. strip of everything after first '.'
*/
final int dot = localHost.indexOf(".");
if (dot != -1) {
localHost = localHost.substring(0, dot);
}
} catch (final UnknownHostException e) {
localHost = "localhost";
}
final String homeDir = getHomeDir();
final String dotCookieFilename = homeDir + File.separator + ".erlang.cookie";
@SuppressWarnings("resource")
BufferedReader br = null;
try {
final File dotCookieFile = new File(dotCookieFilename);
br = new BufferedReader(new FileReader(dotCookieFile));
final String line = br.readLine();
if (line == null) {
defaultCookie = "";
} else {
defaultCookie = line.trim();
}
} catch (final IOException e) {
defaultCookie = "";
} finally {
try {
if (br != null) {
br.close();
}
} catch (final IOException e) {
}
}
}
protected AbstractNode(final OtpTransportFactory transportFactory) {
this.transportFactory = transportFactory;
}
/**
* Create a node with the given name and default cookie and transport factory.
*/
protected AbstractNode(final String node) {
this(node, defaultCookie, new OtpSocketTransportFactory());
}
/**
* Create a node with the given name, transport factory and the default cookie.
*/
protected AbstractNode(final String node,
final OtpTransportFactory transportFactory) {
this(node, defaultCookie, transportFactory);
}
/**
* Create a node with the given name, cookie and default transport factory.
*/
protected AbstractNode(final String name, final String cookie) {
this(name, cookie, new OtpSocketTransportFactory());
}
/**
* Create a node with the given name, cookie and transport factory.
*/
protected AbstractNode(final String name, final String cookie,
final OtpTransportFactory transportFactory) {
this.cookie = cookie;
this.transportFactory = transportFactory;
final int i = name.indexOf('@', 0);
if (i < 0) {
alive = name;
host = localHost;
} else {
alive = name.substring(0, i);
host = name.substring(i + 1, name.length());
}
if (alive.length() > 0xff) {
alive = alive.substring(0, 0xff);
}
node = alive + "@" + host;
}
/**
* Get the name of this node.
*
* @return the name of the node represented by this object.
*/
public String node() {
return node;
}
/**
* Get the hostname part of the nodename. Nodenames are composed of two parts, an
* alivename and a hostname, separated by '@'. This method returns the part of the
* nodename following the '@'.
*
* @return the hostname component of the nodename.
*/
public String host() {
return host;
}
/**
* Get the alivename part of the hostname. Nodenames are composed of two parts, an
* alivename and a hostname, separated by '@'. This method returns the part of the
* nodename preceding the '@'.
*
* @return the alivename component of the nodename.
*/
public String alive() {
return alive;
}
/**
* Get the authorization cookie used by this node.
*
* @return the authorization cookie used by this node.
*/
public String cookie() {
return cookie;
}
// package scope
int type() {
return ntype;
}
// package scope
int distHigh() {
return distHigh;
}
// package scope
int distLow() {
return distLow;
}
// package scope: useless information?
int proto() {
return proto;
}
// package scope
int creation() {
return creation;
}
/**
* Set the authorization cookie used by this node.
*
* @return the previous authorization cookie used by this node.
*/
public String setCookie(final String cookie) {
final String prev = this.cookie;
this.cookie = cookie;
return prev;
}
@Override
public String toString() {
return node();
}
private static String getHomeDir() {
final String home = System.getProperty("user.home");
if (System.getProperty("os.name").toLowerCase().contains("windows")) {
final String drive = System.getenv("HOMEDRIVE");
final String path = System.getenv("HOMEPATH");
return drive != null && path != null ? drive + path : home;
}
return home;
}
@Override
public OtpTransport createTransport(final String addr, final int port)
throws IOException {
return transportFactory.createTransport(addr, port);
}
@Override
public OtpTransport createTransport(final InetAddress addr, final int port)
throws IOException {
return transportFactory.createTransport(addr, port);
}
@Override
public OtpServerTransport createServerTransport(final int port) throws IOException {
return transportFactory.createServerTransport(port);
}
}