From 7756fc2c739c66c8e2db06a30a6c813a19e5d00d Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Tue, 24 May 2016 11:36:35 -0700
Subject: [PATCH] ensure packets are served in order.

---
 lib/bcoin/peer.js | 122 +++++++++++++++++++++++++++++++---------------
 1 file changed, 83 insertions(+), 39 deletions(-)

diff --git a/lib/bcoin/peer.js b/lib/bcoin/peer.js
index 165088ff..c3dd033f 100644
--- a/lib/bcoin/peer.js
+++ b/lib/bcoin/peer.js
@@ -85,6 +85,7 @@ function Peer(pool, options) {
   this.network = this.chain.network;
   this.parser = new bcoin.protocol.parser({ network: this.network });
   this.framer = new bcoin.protocol.framer({ network: this.network });
+  this.locker = new bcoin.locker(this);
   this.version = null;
   this.destroyed = false;
   this.ack = false;
@@ -814,7 +815,7 @@ Peer.prototype.getUTXOs = function getUTXOs(utxos, callback) {
   });
 };
 
-Peer.prototype._getUTXOs = function getUTXOs(utxos, callback) {
+Peer.prototype._getUTXOs = function _getUTXOs(utxos, callback) {
   var index = 0;
   var i, prevout, coin;
 
@@ -851,11 +852,23 @@ Peer.prototype._handleGetUTXOs = function _handleGetUTXOs(payload) {
   var coins = [];
   var hits = [];
 
-  if (this.pool.options.selfish)
+  var unlock = this.locker.lock(_handleGetUTXOs, [payload]);
+  if (!unlock)
     return;
 
+  function done(err) {
+    if (err) {
+      self.emit('error', err);
+      return unlock();
+    }
+    unlock();
+  }
+
+  if (this.pool.options.selfish)
+    return done();
+
   if (this.chain.db.options.spv)
-    return;
+    return done();
 
   function checkMempool(hash, index, callback) {
     if (!self.mempool)
@@ -878,7 +891,7 @@ Peer.prototype._handleGetUTXOs = function _handleGetUTXOs(payload) {
   }
 
   if (payload.prevout.length > 15)
-    return;
+    return done();
 
   utils.forEachSerial(payload.prevout, function(prevout, next, i) {
     var hash = prevout.hash;
@@ -921,7 +934,7 @@ Peer.prototype._handleGetUTXOs = function _handleGetUTXOs(payload) {
     });
   }, function(err) {
     if (err)
-      self.emit('error', err);
+      return done(err);
 
     self.write(self.framer.UTXOs({
       height: self.chain.height,
@@ -929,6 +942,8 @@ Peer.prototype._handleGetUTXOs = function _handleGetUTXOs(payload) {
       hits: hits,
       coins: coins
     }));
+
+    done();
   });
 };
 
@@ -936,14 +951,27 @@ Peer.prototype._handleGetHeaders = function _handleGetHeaders(payload) {
   var self = this;
   var headers = [];
 
-  if (this.pool.options.selfish)
+  var unlock = this.locker.lock(_handleGetHeaders, [payload]);
+  if (!unlock)
     return;
 
+  function done(err) {
+    if (err) {
+      self.emit('error', err);
+      return unlock();
+    }
+    self.sendHeaders(headers);
+    unlock();
+  }
+
+  if (this.pool.options.selfish)
+    return done();
+
   if (this.chain.db.options.spv)
-    return;
+    return done();
 
   if (this.chain.db.options.prune)
-    return;
+    return done();
 
   function collect(err, hash) {
     if (err)
@@ -979,13 +1007,6 @@ Peer.prototype._handleGetHeaders = function _handleGetHeaders(payload) {
     });
   }
 
-  function done(err) {
-    if (err)
-      return self.emit('error', err);
-
-    self.sendHeaders(headers);
-  }
-
   if (!payload.locator)
     return collect(null, payload.stop);
 
@@ -1004,21 +1025,28 @@ Peer.prototype._handleGetBlocks = function _handleGetBlocks(payload) {
   var self = this;
   var blocks = [];
 
-  if (this.pool.options.selfish)
-    return;
-
-  if (this.chain.db.options.spv)
-    return;
-
-  if (this.chain.db.options.prune)
+  var unlock = this.locker.lock(_handleGetBlocks, [payload]);
+  if (!unlock)
     return;
 
   function done(err) {
-    if (err)
-      return self.emit('error', err);
+    if (err) {
+      self.emit('error', err);
+      return unlock();
+    }
     self.sendInv(blocks);
+    unlock();
   }
 
+  if (this.pool.options.selfish)
+    return done();
+
+  if (this.chain.db.options.spv)
+    return done();
+
+  if (this.chain.db.options.prune)
+    return done();
+
   this.chain.findLocator(payload.locator, function(err, tip) {
     if (err)
       return done(err);
@@ -1050,7 +1078,7 @@ Peer.prototype._handleGetBlocks = function _handleGetBlocks(payload) {
   });
 };
 
-Peer.prototype._handleVersion = function handleVersion(payload) {
+Peer.prototype._handleVersion = function _handleVersion(payload) {
   var version = payload.version;
   var services = payload.services;
 
@@ -1139,14 +1167,28 @@ Peer.prototype._handleMempool = function _handleMempool() {
   });
 };
 
-Peer.prototype._handleGetData = function handleGetData(items) {
+Peer.prototype._handleGetData = function _handleGetData(items) {
   var self = this;
   var check = [];
   var notfound = [];
   var i, item, entry, witness;
 
-  if (items.length > 50000)
-    return this._error('message getdata size() = %d', items.length);
+  var unlock = this.locker.lock(_handleGetdata, [items]);
+  if (!unlock)
+    return;
+
+  function done(err) {
+    if (err) {
+      self.emit('error', err);
+      return unlock();
+    }
+    unlock();
+  }
+
+  if (items.length > 50000) {
+    this._error('getdata size too large (%s).', items.length);
+    return done();
+  }
 
   for (i = 0; i < items.length; i++) {
     item = items[i];
@@ -1177,7 +1219,7 @@ Peer.prototype._handleGetData = function handleGetData(items) {
   }
 
   if (this.pool.options.selfish)
-    return;
+    return done();
 
   utils.forEachSerial(check, function(item, next) {
     var type = item.type & ~constants.WITNESS_MASK;
@@ -1231,7 +1273,7 @@ Peer.prototype._handleGetData = function handleGetData(items) {
       }
       if (self.chain.db.options.prune) {
         notfound.push({ type: constants.inv.BLOCK, hash: hash });
-        return;
+        return next();
       }
       return self.chain.db.getBlock(hash, function(err, block) {
         if (err)
@@ -1267,7 +1309,7 @@ Peer.prototype._handleGetData = function handleGetData(items) {
       }
       if (self.chain.db.options.prune) {
         notfound.push({ type: constants.inv.BLOCK, hash: hash });
-        return;
+        return next();
       }
       return self.chain.db.getBlock(hash, function(err, block) {
         if (err)
@@ -1319,10 +1361,12 @@ Peer.prototype._handleGetData = function handleGetData(items) {
 
     if (notfound.length > 0)
       self.write(self.framer.notFound(notfound));
+
+    done();
   });
 };
 
-Peer.prototype._handleAddr = function handleAddr(addrs) {
+Peer.prototype._handleAddr = function _handleAddr(addrs) {
   var now = utils.now();
   var i, addr, ts;
 
@@ -1353,12 +1397,12 @@ Peer.prototype._handleAddr = function handleAddr(addrs) {
     this.hostname);
 };
 
-Peer.prototype._handlePing = function handlePing(data) {
+Peer.prototype._handlePing = function _handlePing(data) {
   this.write(this.framer.pong(data));
   this.fire('ping', this.minPing);
 };
 
-Peer.prototype._handlePong = function handlePong(data) {
+Peer.prototype._handlePong = function _handlePong(data) {
   var now = utils.ms();
 
   if (!this.challenge) {
@@ -1390,7 +1434,7 @@ Peer.prototype._handlePong = function handlePong(data) {
   this.fire('pong', this.minPing);
 };
 
-Peer.prototype._handleGetAddr = function handleGetAddr() {
+Peer.prototype._handleGetAddr = function _handleGetAddr() {
   var hosts = {};
   var items = [];
   var ts = utils.now() - (process.uptime() | 0);
@@ -1436,7 +1480,7 @@ Peer.prototype._handleGetAddr = function handleGetAddr() {
   return this.write(this.framer.addr(items));
 };
 
-Peer.prototype._handleInv = function handleInv(items) {
+Peer.prototype._handleInv = function _handleInv(items) {
   var blocks = [];
   var txs = [];
   var i, item, unknown;
@@ -1466,7 +1510,7 @@ Peer.prototype._handleInv = function handleInv(items) {
     bcoin.debug('Peer sent an unknown inv type: %d (%s).', unknown);
 };
 
-Peer.prototype._handleHeaders = function handleHeaders(headers) {
+Peer.prototype._handleHeaders = function _handleHeaders(headers) {
   headers = headers.map(function(header) {
     return new bcoin.headers(header);
   });
@@ -1474,7 +1518,7 @@ Peer.prototype._handleHeaders = function handleHeaders(headers) {
   this.fire('headers', headers);
 };
 
-Peer.prototype._handleReject = function handleReject(payload) {
+Peer.prototype._handleReject = function _handleReject(payload) {
   var hash, entry;
 
   this.fire('reject', payload);
@@ -1491,7 +1535,7 @@ Peer.prototype._handleReject = function handleReject(payload) {
   entry.reject(this);
 };
 
-Peer.prototype._handleAlert = function handleAlert(details) {
+Peer.prototype._handleAlert = function _handleAlert(details) {
   var hash = utils.dsha256(details.payload);
   var signature = details.signature;