rm-hull / dot-block / 27276150286

61%

Build Type

push

github

Committed by web-flow

Commit Message

feat: add EDNS0 Client Subnet (ECS) support (#151)

* feat: add EDNS0 Client Subnet (ECS) support

- Added `--enable-ecs` flag to enable location-aware DNS responses.
- Implemented subnet calculation based on client IP (masking /24 for
IPv4 and /48 for IPv6).
- Injected ECS option into upstream queries.
- Updated caching logic to include the subnet in the cache key.
- Added comprehensive unit tests for ECS injection and cache key
isolation.

Fixes #50

* test: prevent race condition in ECS injection test

Added a channel synchronization mechanism to ensure the DNS request
is captured before assertions are performed, preventing potential
flaky test failures due to race conditions.

* fix: correctly mask and format ECS subnet IP addresses

Convert `net.IP` objects to string representations instead of casting
raw bytes, and ensure IP addresses are properly masked before being
added to the ECS EDNS0 options.

* fix: update existing EDNS0 subnet option instead of appending

Ensures that the dispatcher updates the existing EDNS0 subnet option
within the DNS OPT record if present, preventing duplicate options
when applying ECS.

* fix: check EDNS0 subnet via option code

Use the explicit `dns.EDNS0SUBNET` constant to identify ECS options
instead of type assertion to ensure more robust matching.

* test: assert server shutdown success in dispatcher tests

Ensure that `server.Shutdown()` returns no error during test cleanup
to prevent silent failures and potential resource leaks.

Coverage Stats

70 of 84 new or added lines in 3 files covered. (83.33%)

11 existing lines in 1 file now uncovered.

1302 of 2148 relevant lines covered (60.61%)

830.71 hits per line