From: Alexandre Montplaisir <alexmonthy@efficios.com>
Date: Wed, 13 Jul 2016 19:36:19 +0000 (-0400)
Subject: Fix: Correctly handle invalid agent port file
X-Git-Tag: v2.9.0-rc1~31
X-Git-Url: http://git.liburcu.org/?p=lttng-ust.git;a=commitdiff_plain;h=8d8c99c9eed441026e2dad93b685f2004034a321

Fix: Correctly handle invalid agent port file

Handle the cases where the Java agent could find a port file
that is either empty, or contains text that cannot be parsed
to a number.

Signed-off-by: Alexandre Montplaisir <alexmonthy@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/liblttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/LttngTcpSessiondClient.java b/liblttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/LttngTcpSessiondClient.java
index f78fdbd0..a0adceae 100644
--- a/liblttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/LttngTcpSessiondClient.java
+++ b/liblttng-ust-java-agent/java/lttng-ust-agent-common/org/lttng/ust/agent/client/LttngTcpSessiondClient.java
@@ -204,27 +204,34 @@ public class LttngTcpSessiondClient implements Runnable {
 	 * @return port value if found else 0.
 	 */
 	private static int getPortFromFile(String path) throws IOException {
-		int port;
 		BufferedReader br = null;
 
 		try {
 			br = new BufferedReader(new InputStreamReader(new FileInputStream(path), PORT_FILE_ENCODING));
 			String line = br.readLine();
-			port = Integer.parseInt(line, 10);
+			if (line == null) {
+				/* File exists but is empty. */
+				return 0;
+			}
+
+			int port = Integer.parseInt(line, 10);
 			if (port < 0 || port > 65535) {
 				/* Invalid value. Ignore. */
 				port = 0;
 			}
+			return port;
+
+		} catch (NumberFormatException e) {
+			/* File contained something that was not a number. */
+			return 0;
 		} catch (FileNotFoundException e) {
 			/* No port available. */
-			port = 0;
+			return 0;
 		} finally {
 			if (br != null) {
 				br.close();
 			}
 		}
-
-		return port;
 	}
 
 	private void registerToSessiond() throws IOException {