[ English follows Chinese ]

此工具帮助Mac/Linux网易云音乐的海外用户解除歌曲锁区限制（所谓锁区：很多歌曲仅限大陆地区播放）。
对用户比较友好。

为什么不使用Unblock-Youku等通用的反向代理解决方案？因为：

1. Mac/Linux版网易云音乐没有内置代理接口，全局代理会使得网络通信变慢；即便使用PAC等，歌曲下载等较大流量也会变慢，并且不稳定
2. 安全原因，请不要轻易相信商业代理服务器...
3. 此工具最傻瓜，绿色😅

不同OS下的类似工具的评论区经常出现“买个会员不就好了”等言论，注意：

1. 即便会员，该锁区也一样锁区，会员只是可以听网易版权歌曲
2. 想了想还是算了，不说了

感谢一个Windows下类似工具提供的思路以及作者的博文。

此工具的使用、传播、修改均无需征得作者同意，同时作者对此不负一切责任。

需要条件：
下载该repo文件夹，不要修改任何文件名
安装python包Twisted, requests和PyQuery（均可用pip安装）。
最新版本的Twisted需要更新pyOpenSSL才能使用。也可以选择装个旧版本。

在每次打开网易云音乐之前：
进入文件夹，双击NeteaseMusicHelper即可。等待提示信息成功之后可以关掉它，然后一片清净，开心听歌，不用善后。

* 如果歌单不再显示灰色，但点击播放时提示「找不到可以播放的歌曲」或者「因版权方要求…您所在地区已下架」，则请尝试pip install service_identity。

vim /usr/share/applications/netease-cloud-music.desktop
修改Exec变量为：
Exec=/bin/bash -c "unset SESSION_MANAGER && netease-cloud-music %U & cd YOUR_PATH_TO_NeteaseMusicHelper && ./NeteaseMusicHelper"
以后只需正常从桌面图标启动网易云音乐即可。

* 为什么要unset SESSION_MANAGER？详见这里

年费会员;

• macOS 10.12 & NeteaseMusic Version 1.5.6~1.5.9 & python 2.7.10/3.6.5
  
• Linux Ubuntu 18.04 & NeteaseMusic Version 1.1.0 & python 2.7.15/3.6.6
  

未测试任何其他情况，欢迎测试报bug谢谢。

见下方Inplementation details。这里只说两点：

1. 歌单中所有歌曲都不再显示灰色，但点击部分下架歌曲（大陆也不能播放）后仍然可能提示“播放失败”。
   
2. 目前对音频文件URL请求（也只有这一请求）采用的是cn-proxy提供的代理列表，缺省代理为作者的阿里云地址。

This tool helps abroad users of macOS/Linux NeteaseMusic unblock songs that are allowed to play in mainland China only.

Why general solutions like Unblock-Youku are not recommended? Because:

1. NeteaseMusic on macOS/Linux does not provide a proxy interface, so global proxy will slow down the network traffic; Even if PAC is used, the latency and unstableness become annoying when it comes to audio stream downloading.
2. For safety reasons, better not to trust commercial proxy servers.
3. This tool is most lightweight and easy to use.

Thanks to a similar tool NeteaseReverseLadder on Windows and the author's blog.

Copyright: The author waives all rights, please feel free to use, share and modify this tool.

Prerequisites:

1. Download this folder and do not change file names.
2. Install Python package Twisted, requests and PyQuery by pip. You may also need to update pyOpenSSL or use a older version of Twisted.

Everytime before you launch NeteaseMusic:
Just enter the folder and double-click "NeteaseMusicHelper". See the success info and then be free to close it, enjoy your music.

* If the playlist looks good but says "No music to be found" or "...copyright...your region is blocked" when you try to play a song, please try pip install service_identity (might work)

Do this at first time: vim /usr/share/applications/netease-cloud-music.desktop
Change "Exec" variable to Exec=/bin/bash -c "unset SESSION_MANAGER && netease-cloud-music %U & cd YOUR_PATH_TO_NeteaseMusicHelper && ./NeteaseMusicHelper"
Then enjoy NeteaseMusic by simply clicking its desktop icon from now on.

Yearly-paid membership;

• macOS 10.12 & NeteaseMusic Version 1.5.6~1.5.9 & python 2.7.10/3.6.5
  
• Linux Ubuntu 18.04 & NeteaseMusic Version 1.1.0 & python 2.7.15/3.6.6
  

Other cases are not tested and your report is welcomed.

Part 1. Force NeteaseMusic to communicate with Netease servers through local proxy.

Methods that I tried:

1. Use pfctl (package forwarding), like iptables on Linux. Not working normally & too less helpful documentations, given up.
2. Use proxychains, a preloader which hooks calls to sockets in dynamically linked programs and redirects it through proxies. It is basically a hack and hacks do not always work. Acting weired on NeteaseMusic for macOS, issue reported at #181. Remaining unsolved.
3. Use networksetup, macOS network PAC. It works easily.

Finally I chose gsettings tool provided by GNOME for redirecting traffics because root privilege won't be needed. iptables can also do the job:

sudo sysctl -w net.ipv4.ip_forward=1
sudo iptables -t nat -A OUTPUT -p tcp -d music.163.com -j REDIRECT --to-ports 32794

but requires to fix redirection-modified request headers. Target parameter TPROXY instead of REDIRECT is actually built for this, however we have another problem unsolved in our case: How to let locally generated packets pass through PREROUTING chain?

Part 2. Intercept, modify and redirect requests.

See NeteaseMusicProxy.py (deployed as local proxy) and AudioRequestProxy.py (deployed as default mainland proxy).

Mainland proxy server is dynamically selected from http://cn-proxy.com/. Because those proxies can be unstable (may be refused by NeteaseMusic server), so an auto proxy selector will replace current proxy with new one or default one after a certain amount of request failures.