fix(youku): cna 获取失败时本地生成兜底，避免 500 (#475)

- mmstat(log.mmstat.com) 被广告过滤/私人 DNS 拦截时，改用本地生成的 24 位 cna
  继续取弹幕；实测优酷弹幕接口只把 cna 当客户端标识回传，不校验其来源
- 首次失败后进程内复用兜底 cna，后续请求不再访问 mmstat
- getEpisodeDanmuSegments 所有失败分支统一返回空 SegmentListResponse，
  getEpisodeDanmu 增加空值兜底，避免 segmentList is not iterable 导致 HTTP 500
- 视频信息解析/时长校验、mtop token 缺失、弹幕属性解析增加防护
- 新增 5 个回归测试覆盖上述场景

danmu_api/sources/youku.js

@@ -11,7 +11,51 @@ import { SegmentListResponse } from '../models/dandan-model.js';
 // =====================
 // 获取优酷弹幕
 // =====================
+
+/**
+ * 生成本地兜底 cna。
+ * 优酷弹幕接口只把 cna 当作请求体里的客户端标识（guid）回传，不校验其来源，
+ * mmstat 域名被广告过滤/私人 DNS 拦截时可用本地生成值代替（详见 getEpisodeDanmuSegments）。
+ */
+function generateLocalCna() {
+  const chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
+  const bytes = new Uint8Array(24);
+  if (typeof globalThis.crypto?.getRandomValues === 'function') {
+    globalThis.crypto.getRandomValues(bytes);
+  } else {
+    for (let i = 0; i < bytes.length; i++) {
+      bytes[i] = Math.floor(Math.random() * 256);
+    }
+  }
+  let cna = '';
+  for (const byte of bytes) {
+    cna += chars[byte % chars.length];
+  }
+  return cna;
+}
+
 export default class YoukuSource extends BaseSource {
+  constructor() {
+    super();
+    // mmstat 取 cna 失败后置为 true，后续请求直接复用本地 cna，避免每次都等待失败请求超时
+    this._useFallbackCna = false;
+    this._fallbackCna = null;
+  }
+
+  _getFallbackCna() {
+    if (!this._fallbackCna) {
+      this._fallbackCna = generateLocalCna();
+    }
+    return this._fallbackCna;
+  }
+
+  _emptySegmentList() {
+    return new SegmentListResponse({
+      "type": "youku",
+      "segmentList": []
+    });
+  }
+
   convertYoukuUrl(url) {
     // 使用正则表达式提取 vid 参数
     const vidMatch = url.match(/vid=([^&]+)/);
@@ -399,12 +443,17 @@ export default class YoukuSource extends BaseSource {
 
     // 获取分片URL列表
     const segmentListResponse = await this.getEpisodeDanmuSegments(id);
-    const segmentList = segmentListResponse.segmentList;
+    const segmentList = segmentListResponse?.segmentList ?? [];
+
+    if (segmentList.length === 0) {
+      log("info", "[youku] 未获取到弹幕分片，返回空结果");
+      return [];
+    }
 
     let contents = [];
 
     // 并发限制（可通过环境变量 YOUKU_CONCURRENCY 配置，默认 8）
-    const concurrency = globals.youkuConcurrency;
+    const concurrency = Math.max(1, Number(globals.youkuConcurrency) || 8);
     const segments = [...segmentList];
 
     for (let i = 0; i < segments.length; i += concurrency) {
@@ -451,10 +500,7 @@ export default class YoukuSource extends BaseSource {
     log("info", "[youku] 获取优酷弹幕分段列表...", id);
 
     if (!id) {
-      return new SegmentListResponse({
-        "type": "youku",
-        "segmentList": []
-      });
+      return this._emptySegmentList();
     }
 
     // 处理302场景
@@ -463,6 +509,11 @@ export default class YoukuSource extends BaseSource {
         id = this.convertYoukuUrl(id);
     }
 
+    if (!id) {
+      log("error", "[youku] Invalid URL");
+      return this._emptySegmentList();
+    }
+
     // 弹幕和视频信息 API 基础地址
     const api_video_info = "https://openapi.youku.com/v2/videos/show.json";
     const api_danmaku = "https://acs.youku.com/h5/mopen.youku.danmu.list/1.0/";
@@ -478,7 +529,7 @@ export default class YoukuSource extends BaseSource {
       log("info", "[youku]", path);
     } else {
       log("error", "[youku] Invalid URL");
-      return [];
+      return this._emptySegmentList();
     }
     const video_id = path[path.length - 1].split(".")[0].slice(3);
 
@@ -497,35 +548,61 @@ export default class YoukuSource extends BaseSource {
       });
     } catch (error) {
       log("error", "[youku] 请求视频信息失败:", error);
-      return [];
+      return this._emptySegmentList();
     }
 
-    const data = typeof res.data === "string" ? JSON.parse(res.data) : res.data;
+    let data;
+    try {
+      data = typeof res?.data === "string" ? JSON.parse(res.data) : res?.data;
+    } catch (error) {
+      log("error", "[youku] 视频信息解析失败:", error.message);
+      return this._emptySegmentList();
+    }
+    if (!data) {
+      log("error", "[youku] 视频信息为空");
+      return this._emptySegmentList();
+    }
     const title = data.title;
-    const duration = data.duration;
+    const duration = Number(data.duration);
+    if (!Number.isFinite(duration) || duration <= 0) {
+      log("error", `[youku] 视频时长无效: ${data.duration}`);
+      return this._emptySegmentList();
+    }
     log("info", `[youku] 标题: ${title}, 时长: ${duration}`);
 
-    // 获取 cna 和 tk_enc
-    let cna, _m_h5_tk_enc, _m_h5_tk;
-    try {
-      const cnaUrl = "https://log.mmstat.com/eg.js";
-      const tkEncUrl = "https://acs.youku.com/h5/mtop.com.youku.aplatform.weakget/1.0/?jsv=2.5.1&appKey=24679788";
-      const cnaRes = await httpGet(cnaUrl, {
-        headers: {
-          "Content-Type": "application/json",
-          "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.88 Safari/537.36",
-        },
-        allow_redirects: false
-      });
-      log("info", `[youku] cnaRes: ${JSON.stringify(cnaRes)}`);
-      log("info", `[youku] cnaRes.headers: ${JSON.stringify(cnaRes.headers)}`);
-      const etag = cnaRes.headers["etag"] || cnaRes.headers["Etag"];
-      log("info", `[youku] etag: ${etag}`);
-      // const match = cnaRes.headers["set-cookie"].match(/cna=([^;]+)/);
-      // cna = match ? match[1] : null;
-      cna = etag.replace(/^"|"$/g, '');
-      log("info", `[youku] cna: ${cna}`);
+    // 获取 cna：mmstat 域名常被广告过滤/私人 DNS 拦截，
+    // 首次失败后改用本地生成的等价格式 cna 兜底，之后不再请求该域名
+    let cna = null;
+    let _m_h5_tk_enc = null, _m_h5_tk = null;
+    if (this._useFallbackCna) {
+      cna = this._getFallbackCna();
+    } else {
+      try {
+        const cnaUrl = "https://log.mmstat.com/eg.js";
+        const cnaRes = await httpGet(cnaUrl, {
+          headers: {
+            "Content-Type": "application/json",
+            "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.88 Safari/537.36",
+          },
+          allow_redirects: false
+        });
+        const etag = cnaRes?.headers?.["etag"] || cnaRes?.headers?.["Etag"];
+        if (typeof etag === "string" && etag.trim()) {
+          cna = etag.replace(/^"|"$/g, '');
+        }
+      } catch (error) {
+        log("info", `[youku] 获取 cna 失败，切换本地生成值兜底: ${error.message}`);
+      }
+      if (!cna) {
+        this._useFallbackCna = true;
+        cna = this._getFallbackCna();
+        log("info", `[youku] 使用本地生成 cna 兜底: ${cna}`);
+      }
+    }
 
+    // 获取 tk_enc / _m_h5_tk（mtop 签名 token 由服务端下发，无法本地生成）
+    try {
+      const tkEncUrl = "https://acs.youku.com/h5/mtop.com.youku.aplatform.weakget/1.0/?jsv=2.5.1&appKey=24679788";
       let tkEncRes;
       while (!tkEncRes) {
         tkEncRes = await httpGet(tkEncUrl, {
@@ -536,10 +613,7 @@ export default class YoukuSource extends BaseSource {
           allow_redirects: false
         });
       }
-      log("info", `[youku] tkEncRes: ${JSON.stringify(tkEncRes)}`);
-      log("info", `[youku] tkEncRes.headers: ${JSON.stringify(tkEncRes.headers)}`);
-      const tkEncSetCookie = tkEncRes.headers["set-cookie"] || tkEncRes.headers["Set-Cookie"];
-      log("info", `[youku] tkEncSetCookie: ${tkEncSetCookie}`);
+      const tkEncSetCookie = tkEncRes?.headers?.["set-cookie"] || tkEncRes?.headers?.["Set-Cookie"] || "";
 
       // 获取 _m_h5_tk_enc
       const tkEncMatch = tkEncSetCookie.match(/_m_h5_tk_enc=([^;]+)/);
@@ -552,8 +626,13 @@ export default class YoukuSource extends BaseSource {
       log("info", `[youku] _m_h5_tk_enc: ${_m_h5_tk_enc}`);
       log("info", `[youku] _m_h5_tk: ${_m_h5_tk}`);
     } catch (error) {
-      log("error", "[youku] 获取 cna 或 tk_enc 失败:", error);
-      return [];
+      log("error", "[youku] 获取 tk_enc 失败:", error);
+      return this._emptySegmentList();
+    }
+
+    if (!_m_h5_tk || !_m_h5_tk_enc) {
+      log("error", "[youku] 未获取到有效的 mtop token，跳过弹幕请求");
+      return this._emptySegmentList();
     }
 
     // 计算弹幕分段请求
@@ -695,8 +774,13 @@ export default class YoukuSource extends BaseSource {
         uid: 0,
         content: "",
       };
-      content.timepoint = item.playat / 1000;
-      const prop = JSON.parse(item.propertis)
+      content.timepoint = Number(item.playat) / 1000 || 0;
+      let prop = null;
+      try {
+        prop = item.propertis ? JSON.parse(item.propertis) : null;
+      } catch (error) {
+        log("info", `[youku] 弹幕属性解析失败，已忽略颜色/位置: ${error.message}`);
+      }
       if (prop?.color) {
         content.color = typeof prop.color === 'string' 
           ? parseInt(prop.color, 10) 
@@ -708,7 +792,7 @@ export default class YoukuSource extends BaseSource {
         else if (pos === 2) content.ct = 4;
       }
       content.content = item.content;
-      content.like = item.extFields.voteUp;
+      content.like = item.extFields?.voteUp ?? 0;
       return content;
     });
   }

danmu_api/worker.test.js

@@ -25,6 +25,7 @@ import { getSourceByKey } from './sources/registry.js';
 import BilibiliSource from "./sources/bilibili.js";
 import { parseHongguoPlayerUrl } from "./sources/hongguo.js";
 import TencentSource from "./sources/tencent.js";
+import YoukuSource from "./sources/youku.js";
 import { NodeHandler } from "./configs/handlers/node-handler.js";
 import { VercelHandler } from "./configs/handlers/vercel-handler.js";
 import { NetlifyHandler } from "./configs/handlers/netlify-handler.js";
@@ -4402,3 +4403,113 @@ test('movies may omit season and episode while TV uploads default both to one',
   assert.equal(elements.get('local-danmu-episode').value, '1');
   assert.match(elements.get('local-danmu-upload-status').textContent, /第1季上传成功/);
 });
+
+test('youku source falls back to a locally generated cna', async (t) => {
+  const youkuUrl = 'https://v.youku.com/v_show/id_XNjQ3ODMyNjU3Mg==.html';
+
+  // 生产路径由 handleRequest/server 初始化 globals（danmuLimit 等），源单测需自行初始化
+  Globals.init({});
+
+  // httpGet/httpPost 依赖真实 Response 形状：ok/status/headers.entries()/text()
+  const mockResponse = (data, headers) => ({
+    ok: true,
+    status: 200,
+    url: '',
+    headers: new Headers(headers),
+    text: async () => (typeof data === 'string' ? data : JSON.stringify(data))
+  });
+
+  const mockDanmakuResponse = () => mockResponse({
+    data: {
+      result: JSON.stringify({
+        code: '0',
+        data: {
+          result: [
+            { playat: 1000, content: '测试弹幕', propertis: '{"color":"16711680","pos":1}', extFields: { voteUp: 3 } }
+          ]
+        }
+      })
+    }
+  }, { 'content-type': 'application/json' });
+
+  const buildYoukuFetch = ({ mmstatFails = false, mmstatMissingEtag = false, tokenFails = false } = {}) => {
+    const calls = { mmstat: 0, token: 0, danmaku: 0 };
+    const fetchImpl = async (url) => {
+      const target = String(url);
+      if (target.includes('log.mmstat.com')) {
+        calls.mmstat++;
+        if (mmstatFails) throw new Error('simulated mmstat block');
+        if (mmstatMissingEtag) return mockResponse('', {});
+        return mockResponse('', { etag: '"maQrIwQESUACASdE0z2p2AgV"' });
+      }
+      if (target.includes('mtop.com.youku.aplatform.weakget')) {
+        calls.token++;
+        if (tokenFails) throw new Error('simulated token block');
+        return mockResponse({}, { 'set-cookie': '_m_h5_tk=token123_456;Path=/;_m_h5_tk_enc=enc123;Path=/' });
+      }
+      if (target.includes('openapi.youku.com/v2/videos/show.json')) {
+        return mockResponse({ title: '测试剧集', duration: 120 }, { 'content-type': 'application/json' });
+      }
+      if (target.includes('mopen.youku.danmu.list')) {
+        calls.danmaku++;
+        return mockDanmakuResponse();
+      }
+      throw new Error(`unexpected fetch: ${target}`);
+    };
+    return { fetchImpl, calls };
+  };
+
+  await t.test('mmstat 被拦截时改用本地 cna 继续取弹幕，且后续不再请求该域名', async () => {
+    const source = new YoukuSource();
+    const { fetchImpl, calls } = buildYoukuFetch({ mmstatFails: true });
+
+    const first = await withMockFetch(fetchImpl, () => source.getComments(youkuUrl, 'youku', false));
+    assert.ok(first.length > 0, 'mmstat 失败后仍应取到弹幕');
+    assert.equal(calls.mmstat, 1);
+
+    const second = await withMockFetch(fetchImpl, () => source.getComments(youkuUrl, 'youku', false));
+    assert.ok(second.length > 0);
+    assert.equal(calls.mmstat, 1, '已切换兜底 cna 时不应重复请求 mmstat');
+  });
+
+  await t.test('mmstat 响应缺少 etag 时同样走本地 cna 兜底', async () => {
+    const source = new YoukuSource();
+    const { fetchImpl, calls } = buildYoukuFetch({ mmstatMissingEtag: true });
+
+    const comments = await withMockFetch(fetchImpl, () => source.getComments(youkuUrl, 'youku', false));
+    assert.ok(comments.length > 0);
+    assert.equal(calls.mmstat, 1);
+  });
+
+  await t.test('mtop token 获取失败时返回空结果而不是抛错', async () => {
+    const source = new YoukuSource();
+    const { fetchImpl } = buildYoukuFetch({ mmstatFails: true, tokenFails: true });
+
+    const segments = await withMockFetch(fetchImpl, () => source.getComments(youkuUrl, 'youku', true));
+    assert.ok(segments instanceof SegmentListResponse);
+    assert.deepEqual(segments.segmentList, []);
+
+    const comments = await withMockFetch(fetchImpl, () => source.getComments(youkuUrl, 'youku', false));
+    assert.deepEqual(comments, []);
+  });
+
+  await t.test('无法解析的链接返回空分片列表而不是抛错', async () => {
+    const segments = await new YoukuSource().getEpisodeDanmuSegments('not-a-youku-url');
+    assert.ok(segments instanceof SegmentListResponse);
+    assert.deepEqual(segments.segmentList, []);
+  });
+
+  await t.test('mmstat 被拦截时 /api/v2/comment 返回 200 而不是 500', async () => {
+    const { fetchImpl } = buildYoukuFetch({ mmstatFails: true });
+    const req = new MockRequest(
+      `${urlPrefix}/api/v2/comment?url=${encodeURIComponent(youkuUrl)}&format=json`,
+      { method: 'GET' }
+    );
+    const res = await withMockFetch(fetchImpl, () => handleRequest(req));
+    const body = await parseResponse(res);
+
+    assert.equal(res.status, 200);
+    assert.equal(body.success, true);
+    assert.ok(body.count > 0);
+  });
+});