From 1e89fac192eafb3935d67333f0339704f6d4afde Mon Sep 17 00:00:00 2001
From: zzz <zzz@mail.i2p>
Date: Wed, 18 Nov 2015 18:12:23 +0000
Subject: [PATCH] SSU: Add support for requesting a relay tag via Session
Request extended options (ticket #1465)
---
.../transport/udp/EstablishmentManager.java | 13 +++++--
.../transport/udp/InboundEstablishState.java | 12 +++++++
.../transport/udp/OutboundEstablishState.java | 18 +++++++++-
.../router/transport/udp/PacketBuilder.java | 19 ++++++----
.../i2p/router/transport/udp/UDPPacket.java | 8 +++++
.../router/transport/udp/UDPPacketReader.java | 35 ++++++++++++++-----
6 files changed, 86 insertions(+), 19 deletions(-)
diff --git a/router/java/src/net/i2p/router/transport/udp/EstablishmentManager.java b/router/java/src/net/i2p/router/transport/udp/EstablishmentManager.java
index 53e7e9d8dd..5ec58a9e9c 100644
--- a/router/java/src/net/i2p/router/transport/udp/EstablishmentManager.java
+++ b/router/java/src/net/i2p/router/transport/udp/EstablishmentManager.java
@@ -131,8 +131,11 @@ class EstablishmentManager {
* Java I2P has always parsed the length of the extended options field,
* but i2pd hasn't recognized it until this release.
* No matter, the options weren't defined until this release anyway.
+ *
+ * FIXME 0.9.22 for testing, change to 0.9.24 for release
+ *
*/
- private static final String VERSION_ALLOW_EXTENDED_OPTIONS = "0.9.24";
+ private static final String VERSION_ALLOW_EXTENDED_OPTIONS = "0.9.22";
public EstablishmentManager(RouterContext ctx, UDPTransport transport) {
@@ -367,8 +370,11 @@ class EstablishmentManager {
}
boolean allowExtendedOptions = VersionComparator.comp(toRouterInfo.getVersion(),
VERSION_ALLOW_EXTENDED_OPTIONS) >= 0;
+ // w/o ext options, it's always 'requested', no need to set
+ boolean requestIntroduction = allowExtendedOptions && _transport.introducersRequired();
state = new OutboundEstablishState(_context, maybeTo, to,
toIdentity, allowExtendedOptions,
+ requestIntroduction,
sessionKey, addr, _transport.getDHFactory());
OutboundEstablishState oldState = _outboundStates.putIfAbsent(to, state);
boolean isNew = oldState == null;
@@ -488,8 +494,9 @@ class EstablishmentManager {
// Don't offer to relay to privileged ports.
// Only offer for an IPv4 session.
// TODO if already we have their RI, only offer if they need it (no 'C' cap)
- // TODO if extended options, only if they asked for it
- if (_transport.canIntroduce() && state.getSentPort() >= 1024 &&
+ // if extended options, only if they asked for it
+ if (state.isIntroductionRequested() &&
+ _transport.canIntroduce() && state.getSentPort() >= 1024 &&
state.getSentIP().length == 4) {
// ensure > 0
long tag = 1 + _context.random().nextLong(MAX_TAG_VALUE);
diff --git a/router/java/src/net/i2p/router/transport/udp/InboundEstablishState.java b/router/java/src/net/i2p/router/transport/udp/InboundEstablishState.java
index 590aa29ed2..96d45c216b 100644
--- a/router/java/src/net/i2p/router/transport/udp/InboundEstablishState.java
+++ b/router/java/src/net/i2p/router/transport/udp/InboundEstablishState.java
@@ -62,6 +62,8 @@ class InboundEstablishState {
private final Queue<OutNetMessage> _queuedMessages;
// count for backoff
private int _createdSentCount;
+ // default true
+ private boolean _introductionRequested = true;
public enum InboundState {
/** nothin known yet */
@@ -150,6 +152,10 @@ class InboundEstablishState {
if (_bobIP == null)
_bobIP = new byte[req.readIPSize()];
req.readIP(_bobIP, 0);
+ byte[] ext = req.readExtendedOptions();
+ if (ext != null && ext.length >= UDPPacket.SESS_REQ_MIN_EXT_OPTIONS_LENGTH) {
+ _introductionRequested = (ext[1] & (byte) UDPPacket.SESS_REQ_EXT_FLAG_REQUEST_RELAY_TAG) != 0;
+ }
if (_log.shouldLog(Log.DEBUG))
_log.debug("Receive sessionRequest, BobIP = " + Addresses.toString(_bobIP));
if (_currentState == InboundState.IB_STATE_UNKNOWN)
@@ -160,6 +166,12 @@ class InboundEstablishState {
public synchronized boolean sessionRequestReceived() { return _receivedX != null; }
public synchronized byte[] getReceivedX() { return _receivedX; }
public synchronized byte[] getReceivedOurIP() { return _bobIP; }
+ /**
+ * True (default) if no extended options in session request,
+ * or value of flag bit in the extended options.
+ * @since 0.9.24
+ */
+ public synchronized boolean isIntroductionRequested() { return _introductionRequested; }
/**
* Generates session key and mac key.
diff --git a/router/java/src/net/i2p/router/transport/udp/OutboundEstablishState.java b/router/java/src/net/i2p/router/transport/udp/OutboundEstablishState.java
index cfb0d2f577..d849bb836b 100644
--- a/router/java/src/net/i2p/router/transport/udp/OutboundEstablishState.java
+++ b/router/java/src/net/i2p/router/transport/udp/OutboundEstablishState.java
@@ -57,6 +57,7 @@ class OutboundEstablishState {
private final RemoteHostId _claimedAddress;
private final RouterIdentity _remotePeer;
private final boolean _allowExtendedOptions;
+ private final boolean _needIntroduction;
private final SessionKey _introKey;
private final Queue<OutNetMessage> _queuedMessages;
private OutboundState _currentState;
@@ -108,12 +109,16 @@ class OutboundEstablishState {
* @param claimedAddress an IP/port based RemoteHostId, or null if unknown
* @param remoteHostId non-null, == claimedAddress if direct, or a hash-based one if indirect
* @param remotePeer must have supported sig type
+ * @param allowExtenededOptions are we allowed to send extended options to Bob?
+ * @param needIntroduction should we ask Bob to be an introducer for us?
+ ignored unless allowExtendedOptions is true
* @param introKey Bob's introduction key, as published in the netdb
* @param addr non-null
*/
public OutboundEstablishState(RouterContext ctx, RemoteHostId claimedAddress,
RemoteHostId remoteHostId,
RouterIdentity remotePeer, boolean allowExtendedOptions,
+ boolean needIntroduction,
SessionKey introKey, UDPAddress addr,
DHSessionKeyBuilder.Factory dh) {
_context = ctx;
@@ -128,6 +133,7 @@ class OutboundEstablishState {
_claimedAddress = claimedAddress;
_remoteHostId = remoteHostId;
_allowExtendedOptions = allowExtendedOptions;
+ _needIntroduction = needIntroduction;
_remotePeer = remotePeer;
_introKey = introKey;
_queuedMessages = new LinkedBlockingQueue<OutNetMessage>();
@@ -161,8 +167,18 @@ class OutboundEstablishState {
/** @return -1 if unset */
public long getIntroNonce() { return _introductionNonce; }
- /** @since 0.9.24 */
+ /**
+ * Are we allowed to send extended options to this peer?
+ * @since 0.9.24
+ */
public boolean isExtendedOptionsAllowed() { return _allowExtendedOptions; }
+
+ /**
+ * Should we ask this peer to be an introducer for us?
+ * Ignored unless allowExtendedOptions is true
+ * @since 0.9.24
+ */
+ public boolean needIntroduction() { return _needIntroduction; }
/**
* Queue a message to be sent after the session is established.
diff --git a/router/java/src/net/i2p/router/transport/udp/PacketBuilder.java b/router/java/src/net/i2p/router/transport/udp/PacketBuilder.java
index 594388716b..a777d819b7 100644
--- a/router/java/src/net/i2p/router/transport/udp/PacketBuilder.java
+++ b/router/java/src/net/i2p/router/transport/udp/PacketBuilder.java
@@ -783,15 +783,20 @@ class PacketBuilder {
* @return ready to send packet, or null if there was a problem
*/
public UDPPacket buildSessionRequestPacket(OutboundEstablishState state) {
- // TODO
- // boolean ext = state.isExtendedOptionsAllowed();
- // if (ext)
- //byte[] options = new byte[3];
- //UDPPacket packet = buildPacketHeader(SESSION_REQUEST_FLAG_BYTE, options);
- UDPPacket packet = buildPacketHeader(SESSION_REQUEST_FLAG_BYTE);
+ int off = HEADER_SIZE;
+ byte[] options;
+ boolean ext = state.isExtendedOptionsAllowed();
+ if (ext) {
+ options = new byte[UDPPacket.SESS_REQ_MIN_EXT_OPTIONS_LENGTH];
+ if (state.needIntroduction())
+ options[1] = (byte) UDPPacket.SESS_REQ_EXT_FLAG_REQUEST_RELAY_TAG;
+ off += UDPPacket.SESS_REQ_MIN_EXT_OPTIONS_LENGTH + 1;
+ } else {
+ options = null;
+ }
+ UDPPacket packet = buildPacketHeader(SESSION_REQUEST_FLAG_BYTE, options);
DatagramPacket pkt = packet.getPacket();
byte data[] = pkt.getData();
- int off = HEADER_SIZE; // + 1 + options.length;
byte toIP[] = state.getSentIP();
if (!_transport.isValid(toIP)) {
diff --git a/router/java/src/net/i2p/router/transport/udp/UDPPacket.java b/router/java/src/net/i2p/router/transport/udp/UDPPacket.java
index fae13ab1ff..a68b848201 100644
--- a/router/java/src/net/i2p/router/transport/udp/UDPPacket.java
+++ b/router/java/src/net/i2p/router/transport/udp/UDPPacket.java
@@ -101,6 +101,14 @@ class UDPPacket implements CDQEntry {
*/
public static final byte HEADER_FLAG_EXTENDED_OPTIONS = (1 << 2);
+ // Extended options for session request
+ public static final int SESS_REQ_MIN_EXT_OPTIONS_LENGTH = 2;
+ // bytes 0-1 are flags
+ /**
+ * set to 1 to request a session tag, i.e. we want him to be an introducer for us
+ */
+ public static final int SESS_REQ_EXT_FLAG_REQUEST_RELAY_TAG = 0x01;
+
// various flag fields for use in the data packets
public static final byte DATA_FLAG_EXPLICIT_ACK = (byte)(1 << 7);
public static final byte DATA_FLAG_ACK_BITFIELDS = (1 << 6);
diff --git a/router/java/src/net/i2p/router/transport/udp/UDPPacketReader.java b/router/java/src/net/i2p/router/transport/udp/UDPPacketReader.java
index 34f8d7bf7b..616f48c4ae 100644
--- a/router/java/src/net/i2p/router/transport/udp/UDPPacketReader.java
+++ b/router/java/src/net/i2p/router/transport/udp/UDPPacketReader.java
@@ -104,6 +104,7 @@ class UDPPacketReader {
/**
* Returns extended option data, 0-255 bytes, or null if none.
+ * Returned array does NOT include the length byte.
*
* @return extended options or null if none is included
* @since 0.9.24
@@ -175,8 +176,26 @@ class UDPPacketReader {
/* ------- Begin Reader Classes ------- */
+ /**
+ * Base
+ *
+ * @since 0.9.24
+ */
+ public abstract class Reader {
+ /**
+ * Returns extended option data from the header, 0-255 bytes, or null if none.
+ * Returned array does NOT include the length byte.
+ *
+ * @return extended options or null if none is included
+ * @since 0.9.24
+ */
+ public byte[] readExtendedOptions() {
+ return UDPPacketReader.this.readExtendedOptions();
+ }
+ }
+
/** Help read the SessionRequest payload */
- public class SessionRequestReader {
+ public class SessionRequestReader extends Reader {
public static final int X_LENGTH = 256;
public void readX(byte target[], int targetOffset) {
int readOffset = readBodyOffset();
@@ -198,7 +217,7 @@ class UDPPacketReader {
}
/** Help read the SessionCreated payload */
- public class SessionCreatedReader {
+ public class SessionCreatedReader extends Reader {
public static final int Y_LENGTH = 256;
public void readY(byte target[], int targetOffset) {
int readOffset = readBodyOffset();
@@ -253,7 +272,7 @@ class UDPPacketReader {
}
/** parse out the confirmed message */
- public class SessionConfirmedReader {
+ public class SessionConfirmedReader extends Reader {
/** which fragment is this? */
public int readCurrentFragmentNum() {
int readOffset = readBodyOffset();
@@ -306,7 +325,7 @@ class UDPPacketReader {
}
/** parse out the data message */
- public class DataReader {
+ public class DataReader extends Reader {
/**
* @return the data size, NOT including IP header, UDP header, IV, or MAC
@@ -642,7 +661,7 @@ class UDPPacketReader {
}
/** Help read the PeerTest payload */
- public class PeerTestReader {
+ public class PeerTestReader extends Reader {
private static final int NONCE_LENGTH = 4;
public long readNonce() {
@@ -683,7 +702,7 @@ class UDPPacketReader {
}
/** Help read the RelayRequest payload */
- public class RelayRequestReader {
+ public class RelayRequestReader extends Reader {
public long readTag() {
long rv = DataHelper.fromLong(_message, readBodyOffset(), 4);
if (_log.shouldLog(Log.DEBUG))
@@ -767,7 +786,7 @@ class UDPPacketReader {
}
/** Help read the RelayIntro payload */
- public class RelayIntroReader {
+ public class RelayIntroReader extends Reader {
public int readIPSize() {
int offset = readBodyOffset();
return _message[offset] & 0xff;
@@ -808,7 +827,7 @@ class UDPPacketReader {
/** Help read the RelayResponse payload */
- public class RelayResponseReader {
+ public class RelayResponseReader extends Reader {
public int readCharlieIPSize() {
int offset = readBodyOffset();
return _message[offset] & 0xff;
--
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