smbioc_lookup
error = smb_usr_lookup((struct smbioc_lookup*)data, scred, &vcp, &ssp);
#define SMBIOC_LOOKUP _IOW('n', 106, struct smbioc_lookup)
int smb_usr_lookup(struct smbioc_lookup *dp, struct smb_cred *scred,
smb_usr_lookup(struct smbioc_lookup *dp, struct smb_cred *scred,