CODEWITHSUNDEEP
javac++socketsdomain-name
The Architect
The Architect

Reputation: 645

Get domain name of incoming connection

I don't find any information on this topic on the internet and asked here. For example I have server with IP 1.1.1.1 and 2.2.2.2 and two domain names pointing to it one.example.com and example2.net, and socke listening on port 1234 for incoming connections.

For example:

C/C++:

listenfd=socket(AF_INET, SOCK_STREAM, 0);
bind(...);
listen(...);
while(...) accept(...);

or Java:

ServerSocket socket = new ServerSocket(1234);
while(...) {
    Socket connectionSocket = welcomeSocket.accept();
    ...
}

When client accepted on my socket I need to know what domain name/IP is used by the client to connect. It may be one.example.com or example2.net and/or IP 1.1.1.1 or 2.2.2.2 (if connected using IP only).

Apache somehow determined ip/domain of incoming reques, and I need to do such thing in pure socket code. C++ (main) or Java (or any other) accepted, I need to know mechaniics of this.

Upvotes: 3

Views: 546

Answers (1)

Paweł Stawarz
Paweł Stawarz

Reputation: 4012

The IP is stored inside the IP packet header and you can read it from there. In order to get the host, you'll probably have to ask a DNS server by sending a request (or use a function which does it for you). You can find examples for both of the problems, even on this site

Upvotes: 3

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