dnsbl

Documentation

Overview

Package dnsbl implements DNS block lists (RFC 5782), for checking incoming messages from sources without reputation.

Index

• Variables
• func CheckHealth(ctx context.Context, resolver dns.Resolver, zone dns.Domain) (rerr error)
• type Status
  • func Lookup(ctx context.Context, resolver dns.Resolver, zone dns.Domain, ip net.IP) (rstatus Status, rexplanation string, rerr error)

Variables

var ErrDNS = errors.New("dnsbl: dns error")

Functions

func CheckHealth

func CheckHealth(ctx context.Context, resolver dns.Resolver, zone dns.Domain) (rerr error)

CheckHealth checks whether the DNSBL "zone" is operating correctly by querying for 127.0.0.2 (must be present) and 127.0.0.1 (must not be present). Users of a DNSBL should periodically check if the DNSBL is still operating properly. For temporary errors, ErrDNS is returned.

Types

type Status

type Status string

Status is the result of a DNSBL lookup.

var (
	StatusTemperr Status = "temperror" // Temporary failure.
	StatusPass    Status = "pass"      // Not present in block list.
	StatusFail    Status = "fail"      // Present in block list.
)

func Lookup

func Lookup(ctx context.Context, resolver dns.Resolver, zone dns.Domain, ip net.IP) (rstatus Status, rexplanation string, rerr error)

Lookup checks if "ip" occurs in the DNS block list "zone" (e.g. dnsbl.example.org).