42 lines
1.3 KiB
JavaScript
42 lines
1.3 KiB
JavaScript
(function (exports) {
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'use strict';
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var dnspack = exports.DNS_PACKER = {
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pack: function (packet) {
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var total = 0;
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var id = packet.header.id; // 2 bytes
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var header = dnspack.packHeader(packet.header); // 2 bytes
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total = 12; // 2+2+2+2 bytes ({qd,an,ns,ar}count)
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var ab = new ArrayBuffer(total);
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var dv = new DataView(ab);
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dv.setUint16(0, id, false);
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dv.setUint16(2, header, false);
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dv.setUint16(4, packet.question.length, false);
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dv.setUint16(6, packet.answer.length, false);
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dv.setUint16(8, packet.authority.length, false);
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// EDNS is added as an additional with TYPE 41 (OPT, 0x29)
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dv.setUint16(10, packet.additional.length + (packet.payload ? 1 : 0), false);
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return ab;
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}
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, packHeader: function(h) {
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var val = 0;
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val += (h.qr << 15) & 0x8000;
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val += (h.opcode << 11) & 0x7800;
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val += (h.aa << 10) & 0x400;
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val += (h.tc << 9) & 0x200;
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val += (h.rd << 8) & 0x100;
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val += (h.ra << 7) & 0x80;
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val += (h.res1 << 6) & 0x40;
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val += (h.res2 << 5) & 0x20;
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val += (h.res3 << 4) & 0x10;
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val += h.rcode & 0xF;
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return val;
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}
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};
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}('undefined' !== typeof window ? window : exports));
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