Replace conn.OpenStream (non-blocking) with conn.OpenStreamSync so that
the resolver waits for the server's MAX_STREAMS credit replenishment frame
instead of immediately failing when the stream limit is temporarily
exhausted. Also retry on StreamLimitReachedError as defense-in-depth for
servers that are slow or fail to send MAX_STREAMS updates.
Pass a quic.Config with KeepAlivePeriod (15s) to DoQ dial calls instead
of nil, so pooled connections send periodic QUIC PINGs to stay alive and
detect dead paths proactively.
Also add IdleTimeoutError to the DoQ retry conditions alongside io.EOF,
so stale pooled connections trigger a transparent retry instead of
propagating as a query failure.
Replace the map-based pool and refCount bookkeeping with a channel-based
pool. Drop the closed state, per-connection address tracking, and extra
mutexes so the pool relies on the channel for concurrency and lifecycle,
matching the approach used in the DoT pool.
Implement TCP/TLS connection pooling for DoT resolver to match DoQ
performance. Previously, DoT created a new TCP/TLS connection for every
DNS query, incurring significant TLS handshake overhead. Now connections are
reused across queries, eliminating this overhead for subsequent requests.
The implementation follows the same pattern as DoQ, using parallel dialing
and connection pooling to achieve comparable performance characteristics.
Consolidate DoH/DoH3/DoQ transport initialization into a single
SetupTransport method and introduce generic helper functions to eliminate
duplicated IP stack selection logic across transport getters.
This reduces code duplication by ~77 lines while maintaining the same
functionality.
Implement QUIC connection pooling for DoQ resolver to match DoH3
performance. Previously, DoQ created a new QUIC connection for every
DNS query, incurring significant handshake overhead. Now connections are
reused across queries, eliminating this overhead for subsequent requests.
The implementation follows the same pattern as DoH3, using parallel dialing
and connection pooling to achieve comparable performance characteristics.
Add detailed logging throughout DNS proxy operations to improve visibility
into query processing, cache operations, and upstream resolver performance.
Key improvements:
- DNS server setup and listener management logging
- Complete query processing pipeline visibility
- Cache hit/miss and stale response handling logs
- Upstream resolver iteration and failure tracking
- Resolver-specific logging (OS, DoH, DoT, DoQ, Legacy)
- All log messages capitalized for better readability
This provides comprehensive debugging capabilities for DNS proxy operations
and helps identify performance bottlenecks and failure points in the
resolution chain.
So setting up logging for ctrld binary and ctrld packages could be done
more easily, decouple the required setup for interactive vs daemon
running.
This is the first step toward replacing rs/zerolog libary with a
different logging library.
Added more descriptive error messages for TLS certificate verification
failures across DoH, DoT, DoQ, and DoH3 protocols. The error messages
now include:
- Certificate subject information
- Issuer organization details
- Common name of the certificate
This helps users and developers better understand certificate validation
failures by providing specific details about the untrusted certificate,
rather than just a generic "unknown authority" message.
Example error message change:
Before: "certificate signed by unknown authority"
After: "certificate signed by unknown authority: TestCA, TestOrg, TestIssuerOrg"
For better recovery and dealing with network stack changes, this commit
change the request flow to:
failure of any kind -> recreate transport/re-bootstrap -> retry once
That would make ctrld recover from all scenarios in theory.
At startup, ctrld gathers bootstrap IP information and use this
bootstrap IP for connecting to upstream. However, in case the network
stack changed, for example, dues to VPN connection, ctrld will still use
this old (maybe invalid) bootstrap IP for the current network stack.
This commit rework the discovering process, and re-initializing the
bootstrap IP if connecting to upstream failed.
Cuong Manh Le