Server IP
You can get the server IP address from $_SERVER['SERVER_ADDR'].
Server MAC address
For the MAC address, you could parse the output of netstat -ie in Linux, or ipconfig /all in Windows.
Client IP address
You can get the client IP from $_SERVER['REMOTE_ADDR']
Client MAC address
The client MAC address will not be available to you except in one special circumstance: if the client is on the same ethernet segment as the server.
So, if you are building some kind of LAN based system and your clients are on the same ethernet segment, then you could get the MAC address by parsing the output of arp -n (linux) or arp -a (windows).
But what if the client isn't on a LAN?
Well, you're out of luck unless you can have the client volunteer that information and transmit via other means.