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dns-suite.js
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sort of round about way to get the email property of SOA RDATA. Let me know if theirs a better way

This commit is contained in:
Daplie 2017-03-15 20:24:03 -06:00
parent 50b134f33b
commit 2388b46c74
1 changed files with 18 additions and 21 deletions
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35
parser/type.soa.js
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@ -18,41 +18,38 @@ exports.DNS_PARSER_TYPE_SOA = function (ab, packet, record) {
var rdataAb = ab.slice(record.rdstart, record.rdstart + record.rdlength);
var dv = new DataView(rdataAb);
// we need this information for this parser
var cpcount = unpackLabels(new Uint8Array(ab), record.rdstart, { byteLength: 0, cpcount: 0, labels: [], name: '' }).cpcount;
var offset = unpackLabels(new Uint8Array(ab), record.rdstart, { byteLength: 0, cpcount: 0, labels: [], name: '' }).byteLength;
var labels = unpackLabels(new Uint8Array(ab), record.rdstart, { byteLength: 0, cpcount: 0, labels: [], name: '' }).labels;
console.log("offset is: " + offset);
console.log("cpcount is: " + cpcount);
console.log("the labels are : " + labels);
console.log("rdstart is: " + record.rdstart);
for(var i = 0; i < dv.byteLength;i++){
console.log(parseInt(dv.getUint8(i), 10).toString(16));
}
// Primary NS
record.name_server = unpackLabels(new Uint8Array(ab), record.rdstart, { byteLength: 0, cpcount: 0, labels: [], name: '' }).name;
// var offset = unpackLabels(new Uint8Array(ab), record.rdstart, { byteLength: 0, cpcount: 0, labels: [], name: '' }).byteLength;
// Admin MB. This email address is always preceeded by 6 Bytes of the name_server data and email_addr length.
// ie: ns1.example.com, where ns1 is 3 bytes, example.com represented by 2 bytes (c0 0c - compression pointer) and then
// 1 more byte representing the email_addr length.
// TODO: email_addr probably shouldn't be parsed this way. The email_addr length byte is probably there to parse this in a more robust way
// we just have to figure that out
// if there exists compression pointers in the rdata
if (cpcount > 0){
// do something awesome with compression pointers to get the email address
// I need the length of all the data before the email address starts.
// if there are compression pointers then there will be a byte to indicate the length of each label, the label,
// then there will be a compression pointer to grab the longest label.
console.log("name server length is: " + record.name_server.length);
var email_len = parseInt(dv.getUint8(0), 10) + ;dv.getUint16(0)
console.log("email_start is: " + email_len);
record.email_addr = unpackLabels(new Uint8Array(ab), record.rdstart , { byteLength: 0, cpcount: 0, labels: [], name: '' }).name;
var start = 2; // start or email_addr. take into account compression pointer and address length
for(var i = 0; i < labels.length; i++){
// increase start by the label length. the +1 is to take into account the next label size byte
start = start + labels[i].length + 1;
// check for cpcount. 2 counts behind
if(parseInt(dv.getUint8(start - 2), 10) === 192){
record.email_addr = unpackLabels(new Uint8Array(ab), record.rdstart + start ,{ byteLength: 0, cpcount: 0, labels: [], name: '' }).name;
}
}
} // if there are no compression pointers, we can get the email address directly from the offset
else {
record.email_addr = unpackLabels(new Uint8Array(ab), record.rdstart + offset, { byteLength: 0, cpcount: 0, labels: [], name: '' }).name;
}
// Serial Number
record.sn = dv.getUint32(dv.byteLength - 20, false);
// Refresh Interval