dns-suite.js/parser/type.soa.js

67 lines
3.0 KiB
JavaScript

(function (exports) {
'use strict';
// Value Meaning/Use
// Primary NS Variable length. The name of the Primary Master for the domain. May be a label, pointer, or any combination
// Admin MB Variable length. The administrator's mailbox. May be a label, pointer, or any combination
// Serial Number Unsigned 32-bit integer
// Refresh Interval Unsigned 32-bit integer
// Retry Interval Unsigned 32-bit integer
// Expiration Limit Unsigned 32-bit integer
// Minimum TTL Unsigned 32-bit integer
var unpackLabels = exports.DNS_UNPACK_LABELS || require('../dns.unpack-labels.js').DNS_UNPACK_LABELS;
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;
// Primary NS
record.name_server = unpackLabels(new Uint8Array(ab), record.rdstart, { byteLength: 0, cpcount: 0, labels: [], name: '' }).name;
// 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.
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
record.ref = dv.getUint32(dv.byteLength - 16, false);
// Retry Interval
record.ret = dv.getUint32(dv.byteLength - 12, false);
// Expiration Limit
record.ex = dv.getUint32(dv.byteLength - 8, false);
// Minimum TTL
record.nx = dv.getUint32(dv.byteLength - 4, false);
return record;
};
}('undefined' !== typeof window ? window : exports));