Get IP from ttyname(3)

[Sharad Chandra]

Hi all,
I was reading man page of ttyname(3). I thought if i have ttyname then using 
that can i have IP address of connected host?. like in sshd logs on log file 
like. 

 ... <host name> sshd[<I guess PID>]: Accepted keyboard-interactive/pam for 
<user name> from <IP> port <port no> ssh2

This IP here is connected hosts ip.. 

is there any api..?

Thanks
Sharad