diff --git a/router/java/src/net/i2p/router/transport/udp/PeerTestManager.java b/router/java/src/net/i2p/router/transport/udp/PeerTestManager.java
index 569fe786a38cf8e02cb0e668bb5a3b9ef5bc529c..9be1c26adff8d347968f12c468e65b8e594bbd6f 100644
--- a/router/java/src/net/i2p/router/transport/udp/PeerTestManager.java
+++ b/router/java/src/net/i2p/router/transport/udp/PeerTestManager.java
@@ -19,23 +19,99 @@ import net.i2p.util.SimpleScheduler;
import net.i2p.util.SimpleTimer;
/**
- *
+ * From udp.html on the website:
+
+<p>The automation of collaborative reachability testing for peers is
+enabled by a sequence of PeerTest messages. With its proper
+execution, a peer will be able to determine their own reachability
+and may update its behavior accordingly. The testing process is
+quite simple:</p>
+
+<pre>
+ Alice Bob Charlie
+ PeerTest ------------------->
+ PeerTest-------------------->
+ <-------------------PeerTest
+ <-------------------PeerTest
+ <------------------------------------------PeerTest
+ PeerTest------------------------------------------>
+ <------------------------------------------PeerTest
+</pre>
+
+<p>Each of the PeerTest messages carry a nonce identifying the
+test series itself, as initialized by Alice. If Alice doesn't
+get a particular message that she expects, she will retransmit
+accordingly, and based upon the data received or the messages
+missing, she will know her reachability. The various end states
+that may be reached are as follows:</p>
+
+<ul>
+<li>If she doesn't receive a response from Bob, she will retransmit
+up to a certain number of times, but if no response ever arrives,
+she will know that her firewall or NAT is somehow misconfigured,
+rejecting all inbound UDP packets even in direct response to an
+outbound packet. Alternately, Bob may be down or unable to get
+Charlie to reply.</li>
+
+<li>If Alice doesn't receive a PeerTest message with the
+expected nonce from a third party (Charlie), she will retransmit
+her initial request to Bob up to a certain number of times, even
+if she has received Bob's reply already. If Charlie's first message
+still doesn't get through but Bob's does, she knows that she is
+behind a NAT or firewall that is rejecting unsolicited connection
+attempts and that port forwarding is not operating properly (the
+IP and port that Bob offered up should be forwarded).</li>
+
+<li>If Alice receives Bob's PeerTest message and both of Charlie's
+PeerTest messages but the enclosed IP and port numbers in Bob's
+and Charlie's second messages don't match, she knows that she is
+behind a symmetric NAT, rewriting all of her outbound packets with
+different 'from' ports for each peer contacted. She will need to
+explicitly forward a port and always have that port exposed for
+remote connectivity, ignoring further port discovery.</li>
+
+<li>If Alice receives Charlie's first message but not his second,
+she will retransmit her PeerTest message to Charlie up to a
+certain number of times, but if no response is received she knows
+that Charlie is either confused or no longer online.</li>
+</ul>
+
+<p>Alice should choose Bob arbitrarily from known peers who seem
+to be capable of participating in peer tests. Bob in turn should
+choose Charlie arbitrarily from peers that he knows who seem to be
+capable of participating in peer tests and who are on a different
+IP from both Bob and Alice. If the first error condition occurs
+(Alice doesn't get PeerTest messages from Bob), Alice may decide
+to designate a new peer as Bob and try again with a different nonce.</p>
+
+<p>Alice's introduction key is included in all of the PeerTest
+messages so that she doesn't need to already have an established
+session with Bob and so that Charlie can contact her without knowing
+any additional information. Alice may go on to establish a session
+with either Bob or Charlie, but it is not required.</p>
+
*/
class PeerTestManager {
private RouterContext _context;
private Log _log;
private UDPTransport _transport;
private PacketBuilder _packetBuilder;
- /** map of Long(nonce) to PeerTestState for tests currently in progress */
- private final Map _activeTests;
- /** current test we are running, or null */
+ /** map of Long(nonce) to PeerTestState for tests currently in progress (as Bob/Charlie) */
+ private final Map<Long, PeerTestState> _activeTests;
+ /** current test we are running (as Alice), or null */
private PeerTestState _currentTest;
private boolean _currentTestComplete;
- private List _recentTests;
+ /** as Alice */
+ private List<Long> _recentTests;
/** longest we will keep track of a Charlie nonce for */
private static final int MAX_CHARLIE_LIFETIME = 10*1000;
+ /**
+ * Have seen peer tests (as Alice) get stuck (_currentTest != null)
+ * so I've thrown some synchronizization on the methods;
+ * don't know the root cause or whether this fixes it
+ */
public PeerTestManager(RouterContext context, UDPTransport transport) {
_context = context;
_transport = transport;
@@ -54,7 +130,11 @@ class PeerTestManager {
private static final int MAX_TEST_TIME = 30*1000;
private static final long MAX_NONCE = (1l << 32) - 1l;
//public void runTest(InetAddress bobIP, int bobPort, SessionKey bobIntroKey) {
- public void runTest(InetAddress bobIP, int bobPort, SessionKey bobCipherKey, SessionKey bobMACKey) {
+
+ /**
+ * The next few methods are for when we are Alice
+ */
+ public synchronized void runTest(InetAddress bobIP, int bobPort, SessionKey bobCipherKey, SessionKey bobMACKey) {
if (_currentTest != null) {
if (_log.shouldLog(Log.WARN))
_log.warn("We are already running a test with bob = " + _currentTest.getBobIP() + ", aborting test with bob = " + bobIP);
@@ -85,30 +165,33 @@ class PeerTestManager {
private class ContinueTest implements SimpleTimer.TimedEvent {
public void timeReached() {
- PeerTestState state = _currentTest;
- if (state == null) {
- // already completed
- return;
- } else if (expired()) {
- testComplete(true);
- } else if (_context.clock().now() - state.getLastSendTime() >= RESEND_TIMEOUT) {
- if (state.getReceiveBobTime() <= 0) {
- // no message from Bob yet, send it again
- sendTestToBob();
- } else if (state.getReceiveCharlieTime() <= 0) {
- // received from Bob, but no reply from Charlie. send it to
- // Bob again so he pokes Charlie
- sendTestToBob();
- } else {
- // received from both Bob and Charlie, but we haven't received a
- // second message from Charlie yet
- sendTestToCharlie();
+ synchronized (PeerTestManager.this) {
+ PeerTestState state = _currentTest;
+ if (state == null) {
+ // already completed
+ return;
+ } else if (expired()) {
+ testComplete(true);
+ } else if (_context.clock().now() - state.getLastSendTime() >= RESEND_TIMEOUT) {
+ if (state.getReceiveBobTime() <= 0) {
+ // no message from Bob yet, send it again
+ sendTestToBob();
+ } else if (state.getReceiveCharlieTime() <= 0) {
+ // received from Bob, but no reply from Charlie. send it to
+ // Bob again so he pokes Charlie
+ sendTestToBob();
+ } else {
+ // received from both Bob and Charlie, but we haven't received a
+ // second message from Charlie yet
+ sendTestToCharlie();
+ }
+ SimpleScheduler.getInstance().addEvent(ContinueTest.this, RESEND_TIMEOUT);
}
- SimpleScheduler.getInstance().addEvent(ContinueTest.this, RESEND_TIMEOUT);
}
}
}
+ /** call from a synchronized method */
private boolean expired() {
PeerTestState state = _currentTest;
if (state != null)
@@ -117,6 +200,7 @@ class PeerTestManager {
return true;
}
+ /** call from a synchronized method */
private void sendTestToBob() {
PeerTestState test = _currentTest;
if (!expired()) {
@@ -128,6 +212,7 @@ class PeerTestManager {
_currentTest = null;
}
}
+ /** call from a synchronized method */
private void sendTestToCharlie() {
PeerTestState test = _currentTest;
if (!expired()) {
@@ -153,9 +238,9 @@ class PeerTestManager {
/**
* Receive a PeerTest message which contains the correct nonce for our current
- * test
+ * test. We are Alice.
*/
- private void receiveTestReply(RemoteHostId from, UDPPacketReader.PeerTestReader testInfo) {
+ private synchronized void receiveTestReply(RemoteHostId from, UDPPacketReader.PeerTestReader testInfo) {
_context.statManager().addRateData("udp.receiveTestReply", 1, 0);
PeerTestState test = _currentTest;
if (expired())
@@ -208,6 +293,7 @@ class PeerTestManager {
if (_log.shouldLog(Log.WARN))
_log.warn("Bob chose a charlie we already have a session to, cancelling the test and rerunning (bob: "
+ _currentTest + ", charlie: " + from + ")");
+ // why are we doing this instead of calling testComplete() ?
_currentTestComplete = true;
_context.statManager().addRateData("udp.statusKnownCharlie", 1, 0);
honorStatus(CommSystemFacade.STATUS_UNKNOWN);
@@ -267,6 +353,9 @@ class PeerTestManager {
* Evaluate the info we have and act accordingly, since the test has either timed out or
* we have successfully received the second PeerTest from a Charlie.
*
+ * @param forgetTest must be true to clear out this test and allow another
+ *
+ * call from a synchronized method
*/
private void testComplete(boolean forgetTest) {
_currentTestComplete = true;
@@ -324,7 +413,7 @@ class PeerTestManager {
* Receive a test message of some sort from the given peer, queueing up any packet
* that should be sent in response, or if its a reply to our own current testing,
* adjusting our test state.
- *
+ * We could be Alice, Bob, or Charlie.
*/
public void receiveTest(RemoteHostId from, UDPPacketReader reader) {
_context.statManager().addRateData("udp.receiveTest", 1, 0);
@@ -334,10 +423,13 @@ class PeerTestManager {
long nonce = testInfo.readNonce();
PeerTestState test = _currentTest;
if ( (test != null) && (test.getNonce() == nonce) ) {
+ // we are Alice
receiveTestReply(from, testInfo);
return;
}
-
+
+ // we are Bob or Charlie
+
if ( (testInfo.readIPSize() > 0) && (testPort > 0) ) {
testIP = new byte[testInfo.readIPSize()];
testInfo.readIP(testIP, 0);
@@ -360,7 +452,7 @@ class PeerTestManager {
// initiated test
} else {
if (_log.shouldLog(Log.DEBUG))
- _log.debug("We are charlie, as te testIP/port is " + RemoteHostId.toString(testIP) + ":" + testPort + " and the state is unknown for " + nonce);
+ _log.debug("We are charlie, as the testIP/port is " + RemoteHostId.toString(testIP) + ":" + testPort + " and the state is unknown for " + nonce);
// we are charlie, since alice never sends us her IP and port, only bob does (and,
// erm, we're not alice, since it isn't our nonce)
receiveFromBobAsCharlie(from, testInfo, nonce, null);
@@ -388,6 +480,8 @@ class PeerTestManager {
}
}
+ // Below here are methods for when we are Bob or Charlie
+
private static final int MAX_RELAYED_PER_TEST = 5;
/**