The previous change marked a rule-matched AD query as a LAN query, but
two paths still reach the OS resolver without that mark, so osResolver
raced the domain controller against 76.76.2.0 in plaintext:
- the DNS-intercept recovery bypass, which forwards queries before
rule handling runs
- the OS-resolver retry catch-all after an explicit upstream fails
with leak_on_upstream_failure enabled
Mark a query under the detected AD domain on both paths. Other names
keep the public fallback, and an explicit upstream is still tried first.
Build resolvers in queryUpstream() through newResolverFn, so tests drive proxy()
and assert the LAN mark that reaches each resolver, instead of testing
the predicate alone.
The auto-added AD split rules route corp names to upstream.os, but a rule
match returned before the LAN-query marking, so osResolver raced the domain
controller against 76.76.2.0 and sent every AD lookup (DC hostnames,
DC-locator SRV names carrying the machine name, WPAD) there in plaintext.
Mark a matched query under the machine's AD domain whose upstreams are the
OS resolver alone as a LAN query, which drops 76.76.2.0 for it.
Port the final merged change from !1009 to master, retaining master's
context-aware logger/resolver APIs, proxy decomposition and firewall
refresh handling. Adapt source regression tests and cover master's
refresh handler and transport-level private-address diagnostics.