these are standard smbclient-related and/or rpcclient-related functions. NetUserGetInfo grabs the information from a NET_USER_INFO_3 structure which is "cached" from the MSV1_0.DLL access token for example (it's a really long story).
NetShareEnum() is a LANMAN function, whoopeee what fun.
in nt, there are _stacks_ of functions that tie pretty much directly into samba source code.
l.