mirror of
https://github.com/status-im/consul.git
synced 2025-02-13 22:26:35 +00:00
d3ee66eed4
This implements parts of RFC 7871 where Consul is acting as an authoritative name server (or forwarding resolver when recursors are configured) If ECS opt is present in the request we will mirror it back and return a response with a scope of 0 (global) or with the same prefix length as the request (indicating its valid specifically for that subnet). We only mirror the prefix-length (non-global) for prepared queries as those could potentially use nearness checks that could be affected by the subnet. In the future we could get more sophisticated with determining the scope bits and allow for better caching of prepared queries that don’t rely on nearness checks. The other thing this does not do is implement the part of the ECS RFC related to originating ECS headers when acting as a intermediate DNS server (forwarding resolver). That would take a quite a bit more effort and in general provide very little value. Consul will currently forward the ECS headers between recursors and the clients transparently, we just don't originate them for non-ECS clients to get potentially more accurate "location aware" results.