I'm gonna say he's got some silky in him:
I'm not an expert but the snout and eye set to me look like there is some silky:
Silky Terrier Information and Pictures, Sydney Terrier, Silky Terriers Australian Silky Terrier - Wikipedia, the free encyclopedia
But again, with all the crosses and breeders out there, you never know.
Do you have his pedigree?
He's a cutie!