*BSD News Article 36576


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From: tls@panix.com (Thor Lancelot Simon)
Newsgroups: comp.unix.bsd,comp.unix.wizards,comp.os.386bsd.questions
Subject: ifconfig alias: now how do I know who I am?
Date: 5 Oct 1994 18:21:41 -0400
Organization: PANIX Public Access Internet and Unix, NYC
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Consider the following problem:  I have a machine which is running a http
server.  I want it to run only one http daemon, but provide different
hierarchies of documents depending upon which IP address it's being talked to
as.

For example:  www.panix.com is an A record for 198.7.0.90.  www.customer.com
is an A record for 198.7.0.91.  I use ifconfig alias to tell www.panix.com
that its ethernet interface is *both* 198.7.0.90 *and* 198.7.0.91.  Now I want
to distinguish between connections to 198.7.0.90 and 198.7.0.91 so that
http://www.panix.com/ and http://www.customer.com really are URLs pointing to
different data.

What I need to know, here, is how I find out what the address I'm _recieving_
a message on is.  Having learned about sockets just by futzing with other
people's code, I have no idea how to do this.  In fact, I'm not sure I've ever
encountered code that does this at all.  

What's the magic word?

[ getsockname()? --mod ]
-- 
Thor Lancelot Simon	                                           tls@panix.COM
-   What is hardest to accept about the passage of time is that the people who -
- once mattered the most to us are wrapped up in parentheses.    --John Irving -