_worker.js

/*
 * https://github.com/netnr/workers
 *
 * 2019-10-12 - 2022-05-05
 * netnr
 *
 * https://github.com/Rongronggg9/rsstt-img-relay
 *
 * 2021-09-13 - 2022-05-29
 * modified by Rongronggg9
 */

export default {
    async fetch(request, _env) {
        return await handleRequest(request);
    }
}

/**
 * Configurations
 */
const config = {
    // 是否丢弃请求中的 Referer，在目标网站应用防盗链时有用
    dropReferer: true,
    // 黑名单，URL 中含有任何一个关键字都会被阻断
    // blockList: [".m3u8", ".ts", ".acc", ".m4s", "photocall.tv", "googlevideo.com", "liveradio.ie"],
    blockList: [],
    typeList: ["image", "video", "audio", "application", "font", "model"]
};

/**
 * Respond to the request
 * @param {Request} request
 */
async function handleRequest(request) {
    //请求头部、返回对象
    let reqHeaders = new Headers(request.headers),
        outBody, outStatus = 200, outStatusText = 'OK', outCt = null, outHeaders = new Headers({
            "Access-Control-Allow-Origin": "*",
            "Access-Control-Allow-Methods": "GET, POST, PUT, PATCH, DELETE, OPTIONS",
            "Access-Control-Allow-Headers": reqHeaders.get('Access-Control-Allow-Headers') || "Accept, Authorization, Cache-Control, Content-Type, DNT, If-Modified-Since, Keep-Alive, Origin, User-Agent, X-Requested-With, Token, x-access-token"
        });

    try {
        //取域名第一个斜杠后的所有信息为代理链接
        let url = request.url.substr(8);
        url = decodeURIComponent(url.substr(url.indexOf('/') + 1));

        //需要忽略的代理
        if (request.method == "OPTIONS" || url.length < 3 || url.indexOf('.') == -1 || url == "favicon.ico" || url == "robots.txt") {
            //输出提示
            const invalid = !(request.method == "OPTIONS" || url.length === 0)
            outBody = JSON.stringify({
                code: invalid ? 400 : 0,
                usage: 'Host/{URL}',
                source: 'https://github.com/Rongronggg9/rsstt-img-relay'
            });
            outCt = "application/json";
            outStatus = invalid ? 400 : 200;
        }
        //阻断
        else if (blockUrl(url)) {
            outBody = JSON.stringify({
                code: 403,
                msg: 'The keyword "' + config.blockList.join(' , ') + '" was block-listed by the operator of this proxy.'
            });
            outCt = "application/json";
            outStatus = 403;
        }
        else {
            url = fixUrl(url);

            //构建 fetch 参数
            let fp = {
                method: request.method,
                headers: {}
            }

            //保留头部其它信息
            const dropHeaders = ['content-length', 'content-type', 'host'];
            if (config.dropReferer) dropHeaders.push('referer');
            let he = reqHeaders.entries();
            for (let h of he) {
                const key = h[0], value = h[1];
                if (!dropHeaders.includes(key)) {
                    fp.headers[key] = value;
                }
            }

            // 是否带 body
            if (["POST", "PUT", "PATCH", "DELETE"].indexOf(request.method) >= 0) {
                const ct = (reqHeaders.get('content-type') || "").toLowerCase();
                if (ct.includes('application/json')) {
                    fp.body = JSON.stringify(await request.json());
                } else if (ct.includes('application/text') || ct.includes('text/html')) {
                    fp.body = await request.text();
                } else if (ct.includes('form')) {
                    fp.body = await request.formData();
                } else {
                    fp.body = await request.blob();
                }
            }

            // 发起 fetch
            let fr = (await fetch(url, fp));
            outCt = fr.headers.get('content-type');
            // 阻断
            if (blockType(outCt)) {
                outBody = JSON.stringify({
                    code: 415,
                    msg: 'The keyword "' + config.typeList.join(' , ') + '" was whitelisted by the operator of this proxy, but got "' + outCt + '".'
                });
                outCt = "application/json";
                outStatus = 415;
            } else {
                outStatus = fr.status;
                outStatusText = fr.statusText;
                outBody = fr.body;
            }
        }
    } catch (err) {
        outCt = "application/json";
        outBody = JSON.stringify({
            code: -1,
            msg: JSON.stringify(err.stack) || err
        });
        outStatus = 500;
    }

    //设置类型
    if (outCt && outCt != "") {
        outHeaders.set("content-type", outCt);
    }

    let response = new Response(outBody, {
        status: outStatus,
        statusText: outStatusText,
        headers: outHeaders
    })

    return response;

    // return new Response('OK', { status: 200 })
}

// 补齐 url
function fixUrl(url) {
    if (url.includes("://")) {
        return url;
    } else if (url.includes(':/')) {
        return url.replace(':/', '://');
    } else {
        return "http://" + url;
    }
}

// 阻断 url
function blockUrl(url) {
    url = url.toLowerCase();
    let len = config.blockList.filter(x => url.includes(x)).length;
    return len != 0;
}
// 阻断 type
function blockType(type) {
    type = type.toLowerCase();
    let len = config.typeList.filter(x => type.includes(x)).length;
    return len == 0;
}