Files
coredns/plugin/https
Ville Vesilehto 0d8cbb1a6b Merge commit from fork
Add configurable resource limits to prevent potential DoS vectors
via connection/stream exhaustion on gRPC, HTTPS, and HTTPS/3 servers.

New configuration plugins:
- grpc_server: configure max_streams, max_connections
- https: configure max_connections
- https3: configure max_streams

Changes:
- Use netutil.LimitListener for connection limiting
- Use gRPC MaxConcurrentStreams and message size limits
- Add QUIC MaxIncomingStreams for HTTPS/3 stream limiting
- Set secure defaults: 256 max streams, 200 max connections
- Setting any limit to 0 means unbounded/fallback to previous impl

Defaults are applied automatically when plugins are omitted from
config.

Includes tests and integration tests.

Signed-off-by: Ville Vesilehto <ville@vesilehto.fi>
2025-12-17 19:08:59 -08:00
..
2025-12-17 19:08:59 -08:00
2025-12-17 19:08:59 -08:00
2025-12-17 19:08:59 -08:00

https

Name

https - configures DNS-over-HTTPS (DoH) server options.

Description

The https plugin allows you to configure parameters for the DNS-over-HTTPS (DoH) server to fine-tune the security posture and performance of the server.

This plugin can only be used once per HTTPS listener block.

Syntax

https {
    max_connections POSITIVE_INTEGER
}
  • max_connections limits the number of concurrent TCP connections to the HTTPS server. The default value is 200 if not specified. Set to 0 for unbounded.

Examples

Set custom limits for maximum connections:

https://.:443 {
    tls cert.pem key.pem
    https {
        max_connections 100
    }
    whoami
}

Set values to 0 for unbounded, matching CoreDNS behaviour before v1.14.0:

https://.:443 {
    tls cert.pem key.pem
    https {
        max_connections 0
    }
    whoami
}