Add basic tests for IGMP packets

decode/igmp.js

@@ -1,38 +1,44 @@
+var IPV4Addr = require("./ipv4_addr");
+
 function IGMP() {
- this.type = null;
- this.version = null;
- this.max_response_time = null;
- this.checksum = null;
- this.group_address = null;
+ this.type = undefined;
+ this.version = undefined;
+ this.maxResponseTime = undefined;
+ this.checksum = undefined;
+ this.groupAddress = undefined;
 }
 
-var IPV4Addr = require("./ipv4_addr");
-
 // http://en.wikipedia.org/wiki/Internet_Group_Management_Protocol
+// This is an implementation of V3
+// https://tools.ietf.org/html/rfc3376
 IGMP.prototype.decode = function (raw_packet, offset) {
  this.type = raw_packet[offset];
- this.max_response_time = raw_packet[offset + 1];
+
+ // units are 1/10s
+ // if value < 128 this is an int, else it is a float
+ // right now we don't handle the float version
+ this.maxResponseTime = raw_packet[offset + 1];
+
  this.checksum = raw_packet.readUInt16BE(offset + 2); // 2, 3
- this.group_address = new IPV4Addr(raw_packet, offset + 4); // 4, 5, 6, 7
+ this.groupAddress = new IPV4Addr(raw_packet, offset + 4); // 4, 5, 6, 7
 
+ //Membership Query (0x11)
+ //Membership Report (IGMPv1: 0x12, IGMPv2: 0x16, IGMPv3: 0x22)
+ //Leave Group (0x17)
  switch (this.type) {
  case 0x11:
- this.version = this.max_response_time > 0 ? 2 : 1;
+ this.version = 3;
  break;
  case 0x12:
  this.version = 1;
  break;
  case 0x16:
- this.version = 2;
- break;
  case 0x17:
  this.version = 2;
  break;
  case 0x22:
  this.version = 3;
  break;
- default:
- break;
  }
 
  return this;

decode/ipv4_addr.js

@@ -1,15 +1,16 @@
 var dec = require("../util").int8_to_dec;
 
 function IPv4Addr(raw_packet, offset) {
- this.o1 = raw_packet[offset];
- this.o2 = raw_packet[offset + 1];
- this.o3 = raw_packet[offset + 2];
- this.o4 = raw_packet[offset + 3];
+ this.addr = new Array(4);
+ this.addr[0] = raw_packet[offset];
+ this.addr[1] = raw_packet[offset + 1];
+ this.addr[2] = raw_packet[offset + 2];
+ this.addr[3] = raw_packet[offset + 3];
 }
 
 // Don't use Array.prototype.join here, because string concat is much faster
 IPv4Addr.prototype.toString = function () {
- return dec[this.o1] + "." + dec[this.o2] + "." + dec[this.o3] + "." + dec[this.o4];
+ return dec[this.addr[0]] + "." + dec[this.addr[1]] + "." + dec[this.addr[2]] + "." + dec[this.addr[3]];
 };
 
 module.exports = IPv4Addr;

spec/decode/igmp.spec.js

@@ -0,0 +1,57 @@
+var Igmp = require("../../decode/igmp");
+var util = require("../../util");
+require("should");
+
+describe("IGMP", function(){
+ var exampleIgmp, instance;
+ beforeEach(function () {
+ exampleIgmp = new Buffer("0102030405060708", "hex");
+ instance = new Igmp();
+ });
+
+ describe("#decode()", function(){
+ it("is a function", function(){
+ instance.decode.should.be.type("function");
+ });
+
+ it("sets the #type to the IGMP type", function() {
+ instance.decode(exampleIgmp, 0);
+ instance.should.have.property("type", 1);
+ });
+
+ it("sets the #maxResponseTime", function() {
+ instance.decode(exampleIgmp, 0);
+ instance.should.have.property("maxResponseTime", 2);
+ });
+
+ it("sets the #checksum", function() {
+ instance.decode(exampleIgmp, 0);
+ instance.should.have.property("checksum", 772);
+ });
+
+ it("sets the #groupAddress", function() {
+ instance.decode(exampleIgmp, 0);
+ instance.groupAddress.should.have.property("addr", [5, 6, 7, 8]);
+ });
+ });
+
+ describe("#toString()", function() {
+ var verifyToString = function verifyToString(type, result){
+ it("return \""+result+"\" for igmp of type="+type, function(){
+ instance = new Igmp();
+ instance.decode(new Buffer(util.int8_to_hex[type] + "000000000000", "hex"), 0);
+ instance.toString().should.be.exactly(result);
+ });
+ };
+
+ //verifyToString(type, string)
+ verifyToString(0x11, "Membership Query");
+ verifyToString(0x12, "Membership Report");
+ verifyToString(0x16, "Membership Report");
+ verifyToString(0x17, "Leave Group");
+ verifyToString(0x22, "Membership Report");
+
+ //Default handler
+ verifyToString(0x01, "type 1");
+ });
+});

spec/decode/ipv4_addr.spec.js

@@ -15,10 +15,7 @@ describe("IPv4Addr", function(){
  it("decodes ip address", function() {
  var instance = new IPv4Addr(exampleIp, 0);
 
- instance.should.have.property("o1", 1);
- instance.should.have.property("o2", 2);
- instance.should.have.property("o3", 3);
- instance.should.have.property("o4", 4);
+ instance.should.have.property("addr", [1, 2, 3, 4]);
  });
  });