max packet size defined

JimmyBjorklund · Jun 15, 2014 · d727d43 · d727d43
1 parent 4a7afb6
commit d727d43
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Showing 2 changed files with 8 additions and 2 deletions.
diff --git a/lib/parameters.js b/lib/parameters.js
@@ -47,4 +47,7 @@ p.exchangeLifetime = p.maxTransmitSpan + p.maxRTT
 // default port for CoAP
 p.coapPort = 5683
 
+// default max packet size
+p.maxPacketSize = 1280
+
 module.exports = p
diff --git a/lib/server.js b/lib/server.js
@@ -202,15 +202,18 @@ function OutMessage() {
 }
 util.inherits(OutMessage, OutgoingMessage)
 
-var maxBlock2 = 1024 //16, 32, 64, must <= 2**(6+4)
+// maxBlock2 is in formular 2**(i+4), and must <= 2**(6+4)
+var maxBlock2 = Math.pow(2, Math.floor(Math.log(parameters.maxPacketSize)/Math.log(2)))
+if (maxBlock2 > Math.pow(2, (6+4)))
+ maxBlock2 = Math.pow(2, (6+4))
 
 OutMessage.prototype.end= function(payload) {
  var that = this
  var requestedBlockOption = _parseBlock2(that._request.options) 
 
  // if payload is suitable for ONE message, shoot it out
  if (!payload || 
- ((!requestedBlockOption) && (payload.length < maxBlock2)))
+ ((!requestedBlockOption) && (payload.length < parameters.maxPacketSize)))
  return OutgoingMessage.prototype.end.call(this, payload)
 
  // for the first request, block2 option may be missed