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Created by magnum on September 27, 2011 11:57:49
Last update: October 05, 2011 12:20:00
This procedure sets up an IPSec vpn server on Linux with Preshared Key (PSK) using Openswan .
Install Openswan:
# yum install openswan
Edit /etc/ipsec.conf . This is about the minimum needed to run IPSec server. Instead of running L2TP on port 1701, I'm running TCP on port 8080 so that I can test the setup with nc later.
# /etc/ipsec.conf - Openswan IPsec configurati...
Edit /etc/ipsec.secrets .
#
# Preshared key for clients connecting from a...
Start IPSec:
# /etc/init.d/ipsec start
Check status:
# ipsec auto --status
Monitor IPSec log:
# less /var/log/secure
If IPSec is running KLIPS, you should see a new nic ( ipsec0 ). There's no ipsec0 if IPSec is running NETKEY.
# ifconfig
eth0 Link encap:Ethernet HWadd...
Created by freyo on August 25, 2011 09:07:40
Last update: August 25, 2011 20:45:43
This is a list of built-in Android permission values: Permission Description Since API Level android.permission.ACCESS_CHECKIN_PROPERTIES Allows read/write access to the "properties" table in the checkin database, to change values that get uploaded. 1 android.permission.ACCESS_COARSE_LOCATION Allows an application to access coarse (e.g., Cell-ID, WiFi) location 1 android.permission.ACCESS_FINE_LOCATION Allows an application to access fine (e.g., GPS) location 1 android.permission.ACCESS_LOCATION_EXTRA_COMMANDS Allows an application to access extra location provider commands 1 android.permission.ACCESS_MOCK_LOCATION Allows an application to create mock location providers for testing 1 android.permission.ACCESS_NETWORK_STATE Allows applications to access information about networks 1 android.permission.ACCESS_SURFACE_FLINGER Allows an application to use SurfaceFlinger's low level features 1 android.permission.ACCESS_WIFI_STATE Allows applications to access information about Wi-Fi networks 1 android.permission.ACCOUNT_MANAGER Allows applications to call into AccountAuthenticators. Only the system can get this permission. 5 android.permission.AUTHENTICATE_ACCOUNTS...
Created by alfa on June 07, 2011 11:34:26
Last update: June 07, 2011 11:36:37
This is an example that uses dynamic proxies to trace method calls (in logging) and print out elapsed times for them. Because dynamic proxies can only be generated for interfaces, the service classes must be implemented with interface-implementation pairs. Create services A and B. A.java :
public interface A { public void service1()... AImpl.java : import java.util.Random; public class AImpl... B.java : public interface B { public void service1()... BImpl.java : public class BImpl implements B { public vo... The call trace proxy: import java.lang.reflect.*; class TraceProx... The performance proxy: import java.lang.reflect.*; class Performan... The service factory: import java.lang.reflect.*; public class Se... The test class: public class Test { public static void main... The output: Entering AImpl.service1 Entering BImpl.service1... The above example has no information...
Created by Dr. Xi on April 28, 2011 11:06:03
Last update: April 28, 2011 11:06:03
The Java Executor interface replaces the call new Thread(new RunnableTask()).start() with executor.execute(new RunnableTask()) . The concurrent package provides built-in utility classes to manage threads so that you don't need to worry about them.
import java.util.concurrent.TimeUnit;
import ja...
Created by Dr. Xi on April 28, 2011 08:58:03
Last update: April 28, 2011 08:58:03
The java.util.concurrent.atomic package is a small toolkit of classes that support lock-free thread-safe programming on single variables .
This is an example of a shared counter without synchronization or lock:
import java.util.concurrent.atomic.AtomicInteger;
...
Created by Dr. Xi on April 27, 2011 15:58:31
Last update: April 27, 2011 20:05:22
From JavaDoc : java.util.concurrent.locks.ReentrantLock is a reentrant mutual exclusion Lock with the same basic behavior and semantics as the implicit monitor lock accessed using synchronized methods and statements, but with extended capabilities. The extended capabilities are: tryLock() : acquire the lock if possible, otherwise immediately return false. tryLock(long timeout, TimeUnit unit) : acquire the lock within the timeout, return false after timeout. lockInterruptibly() : try to acquire the lock and enter wait state, but can be interrupted by other threads and exit waiting. The following shows how java.util.concurrent.locks.ReentrantLock can be used. Start two threads to manipulate the same counter, one incrementing, the other decrementing. Since the counter is incremented and decremented the same number of times, in the end, it should be 0. Without locking,...
