From f487d4f48a241f92a4280b0070aeee10576173b9 Mon Sep 17 00:00:00 2001
From: akwizgran <michael@briarproject.org>
Date: Mon, 26 Nov 2012 22:26:07 +0000
Subject: [PATCH] Don't allow input or output streams to be used after hanging
up.
---
src/net/sf/briar/plugins/modem/Modem.java | 6 +-
src/net/sf/briar/plugins/modem/ModemImpl.java | 60 +++++++++++--------
2 files changed, 36 insertions(+), 30 deletions(-)
diff --git a/src/net/sf/briar/plugins/modem/Modem.java b/src/net/sf/briar/plugins/modem/Modem.java
index 3d55e3c24c..87ac4532c0 100644
--- a/src/net/sf/briar/plugins/modem/Modem.java
+++ b/src/net/sf/briar/plugins/modem/Modem.java
@@ -6,20 +6,18 @@ import java.io.OutputStream;
/**
* A modem that can be used for multiple sequential incoming and outgoing
- * calls.
+ * calls. If an exception is thrown, a new modem instance must be created.
*/
interface Modem {
/**
* Call this method after creating the modem and before making any calls.
- * If an exception is thrown while using the modem, this method must be
- * called again.
*/
void init() throws IOException;
/**
* Initiates an outgoing call and returns true if the call connects. If the
- * call does not connect the modem is hung up and can continue to be used.
+ * call does not connect the modem is hung up.
*/
boolean dial(String number) throws IOException;
diff --git a/src/net/sf/briar/plugins/modem/ModemImpl.java b/src/net/sf/briar/plugins/modem/ModemImpl.java
index c008fad2f5..0a2a5a1041 100644
--- a/src/net/sf/briar/plugins/modem/ModemImpl.java
+++ b/src/net/sf/briar/plugins/modem/ModemImpl.java
@@ -40,7 +40,8 @@ class ModemImpl implements Modem, SerialPortEventListener {
private int lineLen = 0;
- private volatile BlockingQueue<byte[]> received = null;
+ private volatile ModemInputStream inputStream = null;
+ private volatile ModemOutputStream outputStream = null;
ModemImpl(Executor executor, Callback callback, String portName) {
this.executor = executor;
@@ -55,10 +56,8 @@ class ModemImpl implements Modem, SerialPortEventListener {
public void init() throws IOException {
if(LOG.isLoggable(INFO)) LOG.info("Initialising");
try {
- // Open the serial port
if(!port.openPort())
throw new IOException("Failed to open serial port");
- // Find a suitable baud rate
boolean foundBaudRate = false;
for(int baudRate : BAUD_RATES) {
if(port.setParams(baudRate, 8, 1, 0)) {
@@ -68,9 +67,7 @@ class ModemImpl implements Modem, SerialPortEventListener {
}
if(!foundBaudRate)
throw new IOException("Could not find a suitable baud rate");
- // Listen for incoming data and hangup events
port.addEventListener(this);
- // Initialise the modem
port.purgePort(PURGE_RXCLEAR | PURGE_TXCLEAR);
port.writeBytes("ATZ\r\n".getBytes("US-ASCII")); // Reset
port.writeBytes("ATE0\r\n".getBytes("US-ASCII")); // Echo off
@@ -79,11 +76,8 @@ class ModemImpl implements Modem, SerialPortEventListener {
throw new IOException(e.toString());
}
try {
- // Wait for the modem to respond "OK"
synchronized(initialised) {
if(!initialised.get()) initialised.wait(OK_TIMEOUT);
- if(!initialised.get())
- throw new IOException("Modem did not respond");
}
} catch(InterruptedException e) {
if(LOG.isLoggable(WARNING))
@@ -92,7 +86,8 @@ class ModemImpl implements Modem, SerialPortEventListener {
Thread.currentThread().interrupt();
throw new IOException("Interrupted while initialising modem");
}
- received = new LinkedBlockingQueue<byte[]>();
+ if(!initialised.get())
+ throw new IOException("Modem did not respond");
}
public boolean dial(String number) throws IOException {
@@ -125,11 +120,11 @@ class ModemImpl implements Modem, SerialPortEventListener {
}
public InputStream getInputStream() {
- return new ModemInputStream(received);
+ return inputStream;
}
public OutputStream getOutputStream() {
- return new ModemOutputStream();
+ return outputStream;
}
public void hangUp() throws IOException {
@@ -140,8 +135,9 @@ class ModemImpl implements Modem, SerialPortEventListener {
tryToClose(port);
throw new IOException(e.toString());
}
- received.add(new byte[0]); // Empty buffer indicates EOF
- received = new LinkedBlockingQueue<byte[]>();
+ inputStream.closed = true;
+ inputStream.received.add(new byte[0]); // Poison pill
+ outputStream.closed = true;
connected.set(false);
offHook.release();
}
@@ -150,7 +146,7 @@ class ModemImpl implements Modem, SerialPortEventListener {
try {
if(ev.isRXCHAR()) {
byte[] b = port.readBytes();
- if(connected.get()) received.add(b);
+ if(connected.get()) inputStream.received.add(b);
else handleText(b);
} else if(ev.isDSR() && ev.getEventValue() == 0) {
if(LOG.isLoggable(INFO)) LOG.info("Remote end hung up");
@@ -175,22 +171,26 @@ class ModemImpl implements Modem, SerialPortEventListener {
lineLen = 0;
if(LOG.isLoggable(INFO)) LOG.info("Modem status: " + s);
if(s.startsWith("CONNECT")) {
+ inputStream = new ModemInputStream();
+ outputStream = new ModemOutputStream();
+ synchronized(connected) {
+ if(connected.getAndSet(true))
+ throw new IOException("Connected twice");
+ connected.notifyAll();
+ }
// There might be data in the buffer as well as text
int off = i + 1;
if(off < b.length) {
byte[] data = new byte[b.length - off];
System.arraycopy(b, off, data, 0, data.length);
- received.add(data);
- }
- synchronized(connected) {
- if(!connected.getAndSet(true))
- connected.notifyAll();
+ inputStream.received.add(data);
}
return;
} else if(s.equals("OK")) {
synchronized(initialised) {
- if(!initialised.getAndSet(true))
- initialised.notifyAll();
+ if(initialised.getAndSet(true))
+ throw new IOException("Initialised twice");
+ initialised.notifyAll();
}
} else if(s.equals("RING")) {
executor.execute(new Runnable() {
@@ -253,21 +253,23 @@ class ModemImpl implements Modem, SerialPortEventListener {
private byte[] buf = null;
private int offset = 0;
- private ModemInputStream(BlockingQueue<byte[]> received) {
- this.received = received;
+ private volatile boolean closed = false;
+
+ private ModemInputStream() {
+ this.received = new LinkedBlockingQueue<byte[]>();
}
@Override
public int read() throws IOException {
+ if(closed) throw new IOException("Connection closed");
getBufferIfNecessary();
- if(buf.length == 0) return -1;
return buf[offset++];
}
@Override
public int read(byte[] b) throws IOException {
+ if(closed) throw new IOException("Connection closed");
getBufferIfNecessary();
- if(buf.length == 0) return -1;
int len = Math.min(b.length, buf.length - offset);
System.arraycopy(buf, offset, b, 0, len);
offset += len;
@@ -276,8 +278,8 @@ class ModemImpl implements Modem, SerialPortEventListener {
@Override
public int read(byte[] b, int off, int len) throws IOException {
+ if(closed) throw new IOException("Connection closed");
getBufferIfNecessary();
- if(buf.length == 0) return -1;
len = Math.min(len, buf.length - offset);
System.arraycopy(buf, offset, b, off, len);
offset += len;
@@ -295,6 +297,7 @@ class ModemImpl implements Modem, SerialPortEventListener {
Thread.currentThread().interrupt();
throw new IOException(e.toString());
}
+ if(buf.length == 0) throw new IOException("Connection closed");
offset = 0;
}
}
@@ -302,8 +305,11 @@ class ModemImpl implements Modem, SerialPortEventListener {
private class ModemOutputStream extends OutputStream {
+ private volatile boolean closed = false;
+
@Override
public void write(int b) throws IOException {
+ if(closed) throw new IOException("Connection closed");
try {
port.writeByte((byte) b);
} catch(SerialPortException e) {
@@ -314,6 +320,7 @@ class ModemImpl implements Modem, SerialPortEventListener {
@Override
public void write(byte[] b) throws IOException {
+ if(closed) throw new IOException("Connection closed");
try {
port.writeBytes(b);
} catch(SerialPortException e) {
@@ -324,6 +331,7 @@ class ModemImpl implements Modem, SerialPortEventListener {
@Override
public void write(byte[] b, int off, int len) throws IOException {
+ if(closed) throw new IOException("Connection closed");
if(len < b.length) {
byte[] copy = new byte[len];
System.arraycopy(b, off, copy, 0, len);
--
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