Since this code is essentially a fairly plain translation from C, it
is a bit confusing to deal with the original untyped code. This is an
attempt to try and clean some of it up.
Change-Id: Icd21f531932e1a811c0d6dbf2e9acba61ca9c45d
Reviewed-on: https://cl.tvl.fyi/c/depot/+/3734
Tested-by: BuildkiteCI
Reviewed-by: tazjin <mail@tazj.in>