if_nameindex(3) references getifaddrs(3). A getifaddrs(3) xref back to if_nameindex might be helpful. I found it the hard way.
Rob Index: getifaddrs.3 =================================================================== RCS file: /cvs/src/lib/libc/net/getifaddrs.3,v retrieving revision 1.21 diff -u -p -r1.21 getifaddrs.3 --- getifaddrs.3 21 Nov 2015 07:48:10 -0000 1.21 +++ getifaddrs.3 23 Jul 2017 16:54:33 -0000 @@ -133,6 +133,7 @@ or .Sh SEE ALSO .Xr ioctl 2 , .Xr socket 2 , +.Xr if_nameindex 3 , .Xr sysctl 3 , .Xr netintro 4 , .Xr ifconfig 8
