dispatcher.js

import { generateRandomIP } from './ip.js';
import { createRandomSocket, createSocketFromHostname } from './socket.js'
import { Agent, buildConnector } from 'undici'

// taken from `fetch-socks`, many thanks
function resolvePort(protocol, port) {
    return port ? Number.parseInt(port) : protocol === "http:" ? 80 : 443
}

export function createConnectorFromIP(ip, tlsOpts = {}, sockOpts = {}) {
    const undiciConnect = buildConnector(tlsOpts)

    return (options, callback) => {
        let { protocol, hostname, port } = options;

        createSocketFromHostname(
            hostname,
            resolvePort(protocol, port),
            ip,
            sockOpts
        )
        .then(httpSocket => undiciConnect({ ...options, httpSocket }, callback))
        .catch(err => callback(err))
    };
}

export function createRandomConnector(cidr, tlsOpts = {}, sockOpts = {}) {
    const undiciConnect = buildConnector(tlsOpts)

    return (options, callback) => {
        let { protocol, hostname, port } = options;

        createRandomSocket(
            hostname,
            resolvePort(protocol, port),
            cidr,
            sockOpts
        )
        .then(httpSocket => undiciConnect({ ...options, httpSocket }, callback))
        .catch(err => callback(err))
    };
}

export function createRandomStickyConnector(cidr, tlsOpts, options) {
    const { bits, ...sockOpts } = options;
    const ip = generateRandomIP(cidr, bits);
    return createConnectorFromIP(ip, tlsOpts, sockOpts);
}

export function dispatcherFromIP(ip, options = {}) {
    const { connect, ...rest } = options
    return new Agent({ ...rest, connect: createConnectorFromIP(ip, connect, rest) })    
}

export function randomStickyDispatcher(cidr, options = {}) {
    const { connect, ...rest } = options
    return new Agent({ ...rest, connect: createRandomStickyConnector(cidr, connect, rest) })
}

export function randomDispatcher(cidr, options = {}) {
    const { connect, ...rest } = options
    return new Agent({ ...rest, connect: createRandomConnector(cidr, connect, rest) })
}