接受后如何确定使用哪个IP地址？

Question

If I wrote a server bound to a wildcard address ( INADDR_ANY ), how to determine which IP address the client is connected to?

I tried the following code when the after a successful accept call, but it just returned 0.0.0.0.

inet_ntop(AF_INET, &server_address.sin_addr, s, sizeof(s));

Answer 1

As stated in How to determine IP used by client connecting to INADDR_ANY listener socket in C , use getsockname , which gives you the socket which the connection is bound to (on local level).

This is for C, but is applicable for C++ to.

Answer 2

the accept system call will have a address of type struct sockaddr_in or struct sockaddr_in6.

the client address will be stored there.

you can get it using inet_ntoa, or inet_ntop.