edns

Documentation

Overview

Package edns provides function useful for adding/inspecting OPT records to/in messages.

Index

• func SetSupportedOption(option uint16)
• func Size(proto string, size int) int
• func SupportedOption(option uint16) bool
• func Version(req *dns.Msg) (*dns.Msg, error)

Functions

func SetSupportedOption

func SetSupportedOption(option uint16)

SetSupportedOption adds a new supported option the set of EDNS0 options that we support. Plugins typically call this in their setup code to signal support for a new option. By default we support: dns.EDNS0NSID, dns.EDNS0EXPIRE, dns.EDNS0COOKIE, dns.EDNS0TCPKEEPALIVE, dns.EDNS0PADDING. These values are not in this map and checked directly in the server.

func Size

func Size(proto string, size int) int

Size returns a normalized size based on proto.

func SupportedOption

func SupportedOption(option uint16) bool

SupportedOption returns true if the option code is supported as an extra EDNS0 option.

func Version

func Version(req *dns.Msg) (*dns.Msg, error)

Version checks the EDNS version in the request. If error is nil everything is OK and we can invoke the plugin. If non-nil, the returned Msg is valid to be returned to the client (and should). For some reason this response should not contain a question RR in the question section.