C获取侦听服务器的IP

Question

I am writing a client/server program using C sockets. I am specifying that the server can listen on any network interface by using INADDR_ANY in sockaddr_in.sin_addr.s_addr. This is equivalent to an IP of 0.0.0.0. Is it possible for me to get the actual IP that the server is listening on? (eg 192.168.1.100)

Answer 1

I have finally been able to find a solution that works .

Edit : link is dead so see: Internet Archive link .

Hopefully it can be helpful to others as it has been to me.

Answer 2

When you bind a listening socket to INADDR_ANY , the socket listens on all available local IPs. There is no way to determine from the socket which IP(s) it is listening on. If you need that information, then you have to enumerate the local IPs separately (in which case you could just bind() each IP to its own socket individually if you need to retreive pre-accept binding details). However, once accept() has returned an established client connection, you can use getsockname() on the accepted socket to know which specific IP accepted the connection.