Websocket remoteAddress() interface return value

[reischen80]

Websocket remoteAddress() interface return value

[chobie]

The following is a document for CAPI, but it internally uses remoteAddress.
https://github.com/paullouisageneau/libdatachannel/blob/master/DOC.md#rtcgetremoteaddress

Retrieves the current remote address, i.e. the network address of the currently selected remote candidate. The address will have the format "IP_ADDRESS:PORT", where IP_ADDRESS may be either IPv4 or IPv6. The call may fail if the state is not RTC_CONNECTED, and the address might change after connection.

I think it would be good to search for ':' from the end and then split (like std::string::rfind).

It doesn't seem like there was a single API that returns the hostname or port number.
If necessary, wouldn't it be better to consider adding one?

[reischen80]

Following C++ WebSocket Class use the same implementation as CAPI
optional<string> remoteAddress() const;

I'd just like to know, why the result string have a strange form of "::ffff:105.11.31.26:9204", expected to be "105.11.31.26:9204". The last one will be easily to split and interpret.
It is a bug inside?

[chobie]

The format ::ffff:x.x.x.x is used to maintain compatibility between IPv6 and IPv4, as far as I remember. For more details, I suggest referring to RFC 4291.

[reischen80]

Got it! Thanks!

[paullouisageneau]

FYI this format is called IPv4-mapped IPv6 address. It can currently be returned by WebSocket::remoteAddress() if you listen on IPv6+IPv4 and the remote client connects over IPv4.