shlist

commit 8e9008b7f992f0fea2c2a7366e7615f49a735e0a
parent 72e45b1281e0ec88f7e5564dd3ff83c8b51574a4
Author: David Engel <dengel@ucalgary.ca>
Date:   Fri, 28 Apr 2017 22:50:02 -0600

server: sockets timeout after 5 seconds to prevent thread exhaustion from attackers

Diffstat:
M
server/shlist/Server.java
 | 
8
+++++---
M
server/shlist/Worker.java
 | 
19
+++++++++++--------

2 files changed, 16 insertions(+), 11 deletions(-)
diff --git a/server/shlist/Server.java b/server/shlist/Server.java
@@ -3,6 +3,7 @@ package shlist;
 import java.io.IOException;
 import java.net.ServerSocket;
 import java.net.Socket;
+import java.net.SocketTimeoutException;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 
@@ -21,7 +22,7 @@ public class Server {
 		try {
 			sSock = new ServerSocket(PORT);
 		} catch (IOException e) {
-			e.printStackTrace();
+			System.out.println("IO Error1: " + e);
 		}
 		
 		// Add the runtime hook, for ctrl+c
@@ -31,11 +32,12 @@ public class Server {
 		while (true) {
 			try {
 				sock = sSock.accept();
+				sock.setSoTimeout(5000);
+				exec.execute(new Worker(sock));
 			} catch (IOException e) {
-					//System.out.println("IO Error: " + e);
+					System.out.println("IO Error: " + e);
 					break;
 			}
-			exec.execute(new Worker(sock));
 		}
 	}
 }
diff --git a/server/shlist/Worker.java b/server/shlist/Worker.java
@@ -20,7 +20,6 @@ public class Worker implements Runnable {
             inp = sock.getInputStream();
             brinp = new BufferedReader(new InputStreamReader(inp));
         } catch (IOException e) {
-        	e.printStackTrace();
             return;
         }
         System.out.println("Started new thread");
@@ -29,15 +28,19 @@ public class Worker implements Runnable {
             line = brinp.readLine();
             if (line != null) {
             	System.out.println(line);
-            } else {
-            	sock.close();
-            	brinp.close();
-            	System.out.println("Closing Socket");
             }
+        	sock.close();
+        	brinp.close();
+        	System.out.println("Closing Socket");
         } catch (IOException e) {
-            e.printStackTrace();
-            return;
-            }
+        	try {
+	        	sock.close();
+	        	brinp.close();
+	        	System.out.println("Closing Socket");
+        	} catch (IOException e1) {
+        		e1.printStackTrace();
+        	}
+        }
         System.out.println("Exiting Thread");
 	}
 }