33 lines
953 B
TypeScript
33 lines
953 B
TypeScript
import { ConnectionData } from "../connection-data.ts";
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export async function discoverIP(
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conn: ConnectionData,
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ssrc: string,
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hostname: string,
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port: number
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) {
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const discover = createDiscoverPacket(ssrc);
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await conn.udpSocket.send(discover, {
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hostname,
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port,
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transport: "udp",
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});
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const { value } = await conn.udpStream().next();
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const decoder = new TextDecoder();
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const localIp = decoder.decode(value.slice(8, value.indexOf(0, 8)));
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const localPort = new DataView(value.buffer).getUint16(72, false);
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return { ip: localIp, port: localPort };
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}
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function createDiscoverPacket(ssrc: string): Uint8Array {
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const buffer = new ArrayBuffer(74);
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const header_data = new DataView(buffer);
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let offset = 0;
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header_data.setInt16(offset, 1, false);
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offset += 2;
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header_data.setInt16(offset, 70, false);
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offset += 2;
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header_data.setInt32(offset, Number.parseInt(ssrc), false);
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return new Uint8Array(buffer);
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}
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