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iefsergeiefserge
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IP4 fragmented packets reassembly
1 parent 67ba182 commit 66838f5

14 files changed

Lines changed: 951 additions & 8 deletions

‎js/core/net/interface.js‎

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Original file line numberDiff line numberDiff line change
@@ -35,6 +35,7 @@ function Interface(macAddr) {
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this.bufferDataOffset = 0;
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this.arp = new ARPResolver(this);
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this.isNetworkEnabled = false;
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this.fragments = new Map();
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}
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Interface.prototype.disableArp = function() {

‎js/core/net/ip4-fragments.js‎

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@@ -0,0 +1,164 @@
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// Copyright 2015 runtime.js project authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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'use strict';
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var ip4header = require('./ip4-header');
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var ip4receive = require('./ip4-receive');
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function fragmentHash(srcIP, destIP, protocolId, packetId) {
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return srcIP.toInteger() + '-' + destIP.toInteger() + '-' + (packetId + (protocolId << 16));
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}
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function dropFragmentQueue(intf, hash) {
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intf.fragments.delete(hash);
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}
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exports.addFragment = function(intf, u8, headerOffset, fragmentOffset, isMoreFragments) {
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var headerLength = ip4header.getHeaderLength(u8, headerOffset);
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var protocolId = ip4header.getProtocolId(u8, headerOffset);
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var srcIP = ip4header.getSrcIP(u8, headerOffset);
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var destIP = ip4header.getDestIP(u8, headerOffset);
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var packetId = ip4header.getIdentification(u8, headerOffset);
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var nextOffset = headerOffset + headerLength;
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var hash = fragmentHash(srcIP, destIP, packetId, protocolId);
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var firstFragment = false;
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var fragmentQueue = intf.fragments.get(hash);
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if (!fragmentQueue) {
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firstFragment = true;
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fragmentQueue = {
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receivedLength: 0,
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totalLength: 0,
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fragments: []
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};
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}
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var fragmentLength = u8.length - nextOffset;
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if (fragmentLength <= 0) {
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return;
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}
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var fragmentEnd = fragmentOffset + fragmentLength;
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if (fragmentEnd > 0xffff) {
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return;
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}
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// Locate non overlapping portion of new fragment
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var newOffset = fragmentOffset;
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var newEnd = fragmentEnd;
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var newNextOffset = nextOffset;
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for (var i = 0, l = fragmentQueue.fragments.length; i < l; ++i) {
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var fragment = fragmentQueue.fragments[i];
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if (!fragment) {
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continue;
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}
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var fragBegin = fragment[0];
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var fragEnd = fragBegin + fragment[1];
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var overlapOffset = newOffset >= fragBegin && newOffset <= fragEnd;
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var overlapEnd = newEnd >= fragBegin && newEnd <= fragEnd;
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// New fragment is fully contained within another fragment,
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// just ignore it
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if (overlapOffset && overlapEnd) {
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return;
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}
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// First fragment byte is somewhere withing existing fragment
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if (overlapOffset && newOffset < fragEnd) {
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newNextOffset += fragEnd - newOffset;
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newOffset = fragEnd;
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}
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// Last fragment byte is somewhere withing existing fragment
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if (overlapEnd && newEnd > fragBegin) {
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newEnd = fragBegin;
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}
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}
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// Remove old fragments fully contained within the new one
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// By doing this we can avoid splitting big new fragments into
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// smaller chunks
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var removedIndex = -1;
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for (var i = 0, l = fragmentQueue.fragments.length; i < l; ++i) {
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var fragment = fragmentQueue.fragments[i];
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if (!fragment) {
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continue;
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}
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var fragBegin = fragment[0];
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var fragEnd = fragBegin + fragment[1];
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if (fragBegin >= newOffset && fragBegin <= newEnd &&
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fragEnd >= newOffset && fragEnd <= newEnd) {
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// remove this old fragment
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fragmentQueue.fragments[i] = null;
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fragmentQueue.receivedLength -= fragment[1];
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removedIndex = i;
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}
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}
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var newLength = newEnd - newOffset;
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// fragment offset - fragement length - buffer data offset - buffer
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var newFragment = [newOffset, newLength, newNextOffset, u8];
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if (removedIndex >= 0) {
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fragmentQueue.fragments[removedIndex] = newFragment;
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} else {
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fragmentQueue.fragments.push(newFragment);
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}
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fragmentQueue.receivedLength += newLength;
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// Last fragment?
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if (!isMoreFragments) {
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// Another last fragment?
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if (fragmentQueue.totalLength > fragmentEnd) {
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// Wrong len
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return;
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}
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fragmentQueue.totalLength = fragmentEnd;
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}
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if (firstFragment) {
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intf.fragments.set(hash, fragmentQueue);
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}
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if (fragmentQueue.totalLength === fragmentQueue.receivedLength) {
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var u8asm = new Uint8Array(fragmentQueue.totalLength);
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for (var i = 0, l = fragmentQueue.fragments.length; i < l; ++i) {
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var fragment = fragmentQueue.fragments[i];
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if (!fragment) {
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continue;
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}
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var itemOffset = fragment[0];
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var itemLength = fragment[1];
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var itemNextOffset = fragment[2];
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var itemBuffer = fragment[3];
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u8asm.set(itemBuffer.subarray(itemNextOffset, itemNextOffset + itemLength), itemOffset);
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}
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dropFragmentQueue(intf, hash);
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ip4receive(intf, srcIP, destIP, protocolId, u8asm, 0);
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return;
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}
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};

‎js/core/net/ip4-header.js‎

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Original file line numberDiff line numberDiff line change
@@ -46,6 +46,26 @@ exports.getHeaderLength = function(u8, headerOffset) {
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return (u8[headerOffset] & 0xf) << 2;
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};
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exports.getFragmentationData = function(u8, headerOffset) {
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return u8view.getUint16BE(u8, headerOffset + 6);
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};
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exports.getIdentification = function(u8, headerOffset) {
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return u8view.getUint16BE(u8, headerOffset + 4);
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};
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exports.fragmentationDataIsMoreFragments = function(value) {
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return !!((value >>> 13) & 0x1);
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};
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exports.fragmentationDataIsDontFragment = function(value) {
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return !!((value >>> 14) & 0x1);
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};
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exports.fragmentationDataOffset = function(value) {
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return (value & 0x1fff) * 8;
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};
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exports.minHeaderLength = minHeaderLength;
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exports.write = function(u8, headerOffset, protocolId, srcIP, destIP, packetLength) {

‎js/core/net/ip4-receive.js‎

Lines changed: 27 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,27 @@
1+
// Copyright 2015 runtime.js project authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
5+
// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
10+
// distributed under the License is distributed on an "AS IS" BASIS,
11+
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12+
// See the License for the specific language governing permissions and
13+
// limitations under the License.
14+
15+
'use strict';
16+
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var udp = require('./udp');
18+
var tcp = require('./tcp');
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var icmp = require('./icmp');
20+
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module.exports = function(intf, srcIP, destIP, protocolId, u8, nextOffset) {
22+
switch (protocolId) {
23+
case 0x01: return icmp.receive(intf, srcIP, destIP, u8, nextOffset);
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case 0x06: return tcp.receive(intf, srcIP, destIP, u8, nextOffset);
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case 0x11: return udp.receive(intf, srcIP, destIP, u8, nextOffset);
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}
27+
};

‎js/core/net/ip4.js‎

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Original file line numberDiff line numberDiff line change
@@ -15,20 +15,27 @@
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'use strict';
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var IP4Address = require('./ip4-address');
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var ip4header = require('./ip4-header');
18-
var udp = require('./udp');
19-
var tcp = require('./tcp');
20-
var icmp = require('./icmp');
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var ip4fragments = require('./ip4-fragments');
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var ip4receive = require('./ip4-receive');
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22-
exports.receive = function(intf, u8, headerOffset) {
21+
function handleReceive(intf, u8, headerOffset) {
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var headerLength = ip4header.getHeaderLength(u8, headerOffset);
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var protocolId = ip4header.getProtocolId(u8, headerOffset);
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var srcIP = ip4header.getSrcIP(u8, headerOffset);
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var destIP = ip4header.getDestIP(u8, headerOffset);
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var nextOffset = headerOffset + headerLength;
27+
ip4receive(intf, srcIP, destIP, protocolId, u8, nextOffset);
28+
}
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30+
exports.receive = function(intf, u8, headerOffset) {
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var fragmentData = ip4header.getFragmentationData(u8, headerOffset);
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var isMoreFragments = ip4header.fragmentationDataIsMoreFragments(fragmentData);
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var fragmentOffset = ip4header.fragmentationDataOffset(fragmentData);
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29-
switch (protocolId) {
30-
case 0x01: return icmp.receive(intf, srcIP, destIP, u8, nextOffset);
31-
case 0x06: return tcp.receive(intf, srcIP, destIP, u8, nextOffset);
32-
case 0x11: return udp.receive(intf, srcIP, destIP, u8, nextOffset);
35+
if (!isMoreFragments && fragmentOffset === 0) {
36+
handleReceive(intf, u8, headerOffset);
37+
return;
3338
}
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ip4fragments.addFragment(intf, u8, headerOffset, fragmentOffset, isMoreFragments);
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};

‎js/core/net/mac-address.js‎

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Original file line numberDiff line numberDiff line change
@@ -42,4 +42,31 @@ MACAddress.prototype.equals = function(that) {
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MACAddress.BROADCAST = new MACAddress(0xff, 0xff, 0xff, 0xff, 0xff, 0xff);
4343
MACAddress.ZERO = new MACAddress(0, 0, 0, 0, 0, 0);
4444

45+
MACAddress.parse = function(str) {
46+
if (str instanceof MACAddress) {
47+
return str;
48+
}
49+
50+
if ('string' !== typeof str) {
51+
return null;
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}
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var p = str.trim().split(':');
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if (6 !== p.length) {
56+
return null;
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}
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var a = new Array(6);
60+
for (var i = 0; i < 6; ++i) {
61+
var v = parseInt(p[i], 16) | 0;
62+
if (v !== parseInt(p[i], 16) || v < 0 || v > 255) {
63+
return null;
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}
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a[i] = v;
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}
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return new MACAddress(a[0], a[1], a[2], a[3], a[4], a[5]);
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};
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module.exports = MACAddress;

‎js/test/unit/index.js‎

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Original file line numberDiff line numberDiff line change
@@ -28,6 +28,7 @@ stream.on('data', function(v) {
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stream.on('end', shutdown);
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3030
require('./script');
31+
require('./lib/test');
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require('./buffers');
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require('./platform');
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require('./timers');

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