[FFmpeg-devel] [PATCH 2/2] add socks5 support for tcp clients

[Moritz Barsnick]

Now that I have tested this:

On Sat, Jun 13, 2020 at 23:17:41 +0800, levizhao at live.cn wrote:
>  #endif /* !HAVE_WINSOCK2_H */
> +    char *socks_proxy;
>  } TCPContext;
[...]
>      { "listen",          "Listen for incoming connections",  OFFSET(listen),         AV_OPT_TYPE_INT, { .i64 = 0 },     0,       2,       .flags = D|E },
> +    { "socks_proxy",     "set socks proxy for connection", OFFSET(socks_proxy),   AV_OPT_TYPE_STRING, { .str = NULL }, 0,     0,       .flags = D },
>      { "timeout",     "set timeout (in microseconds) of socket I/O operations", OFFSET(rw_timeout),     AV_OPT_TYPE_INT, { .i64 = -1 },         -1, INT_MAX, .flags = D|E },

You're not using this variable anywhere. So the introduced command line
option is dead.

> +    proxy_path = getenv("socks_proxy");
> +    use_proxy = proxy_path && av_strstart(proxy_path, "socks5://", NULL);
> +    if(use_proxy) {

And here's the reason:
You use the environment variable only.

Furthermore, I'm not sure this is the proper convention for specifying
a SOCKS proxy in the environment. I found various other suggestions
around the net, but not this one. Please don't invent one, instead make
the command line option functional.

>      .url_open            = tcp_open,
> +    .url_open2            = tcp_open2,

If the url_open2 function pointer exists, url_open will never be used.
So you should be writing a *replacement* function for tcp_open(), not
an amendment.

Actually, since your tcp_open2() doesn't even use the "options"
argument, it would be a url_open callback. url_open2: "This callback is
to be used by protocols which open further nested protocols." I think
this does not apply to the "tcp" protocol.

Therefore, you should merge the socks functionality into the existing
tcp_open().

I would also appreciate a log message (at level verbose or debug),
indicating that a SOCKS "redirection" is taking place. Otherwise,
there's a seemingly random mismatch between the URI's hostname and the
logged IP/port.


All this said, when using the environment variable, I managed to get
ffmpeg to connect to an http:// and an https:// input URL (HLS) through
a SOCKS5 proxy. So at least it works. Thanks for your effort so far.

Regards,
Moritz