block

README

block

Name

blocklist - uses pi-hole-like block lists to block nefarious domains.

Description

The blocklist plugin will fetch configured blocklists from the internet and block local clients from resolving the domains listed on them.

For a domain that is blocked we will return a NXDOMAIN response.

This plugin is a WIP.

Syntax

blocklist https://hosts-file.net/ad_servers.txt
blocklist override {
    always_allow employer.com
    block competitor.com
}

(see also the sample Corefile in this directory)

Metrics

If monitoring is enabled (via the prometheus directive) the following metric is exported:

• coredns_blocklist_count_total{server} - counter of total number of blocked domains.
• coredns_blocklist_fetch{list, result} - counter of list fetch attempts and the results of the fetch operation.
• coredns_blocklist_list_size{list} - number of blocked domains on each configured list.

The list label contains the URL of the blocklist in question; the result label is either OK or a brief error string.

The server label indicates which server handled the request, see the metrics plugin for details.

Documentation

Overview

Package blocklist contains a blocklist plugin for CoreDNS.

Index

• type Blocker
• type Blocklist
  • func New(db *MemoryDB) *Blocklist
  • func (b *Blocklist) Name() string
  • func (b *Blocklist) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error)
  • func (b *Blocklist) Start() error
  • func (b *Blocklist) Stop() error
• type HashDB
  • func (h HashDB) Block(domain string) bool
• type List
  • func NewList(source string) *List
  • func (l *List) Run(db ListDB, stop <-chan struct{}, poke chan<- struct{})
• type ListDB
• type MemoryDB
  • func NewMemoryDB() *MemoryDB
  • func (db *MemoryDB) Block(domain string) bool
  • func (db *MemoryDB) LastFetched(source string) time.Time
  • func (db *MemoryDB) Pokee(stop, poke <-chan struct{})
  • func (db *MemoryDB) Update(source string, fetched time.Time, blocked []string) error

Types

type Blocker

type Blocker interface {
	Block(string) bool
}

Blocker returns true for blocked DNS domains.

type Blocklist

type Blocklist struct {
	Next plugin.Handler
	// contains filtered or unexported fields
}

Blocklist is the blocklist plugin.

func New

func New(db *MemoryDB) *Blocklist

New returns a new Blocklist.

func (*Blocklist) Name

func (b *Blocklist) Name() string

Name implements the Handler interface.

func (*Blocklist) ServeDNS

func (b *Blocklist) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error)

ServeDNS implements the plugin.Handler interface.

func (*Blocklist) Start

func (b *Blocklist) Start() error

Start starts the internals of Blocklist.

func (*Blocklist) Stop

func (b *Blocklist) Stop() error

Stop stops the internals of Blocklist.

type HashDB

type HashDB map[string]bool

HashDB is a hash-backed static list of blocked domains.

func (HashDB) Block

func (h HashDB) Block(domain string) bool

type List

type List struct {
	// contains filtered or unexported fields
}

List represents a single blocklist.

func NewList

func NewList(source string) *List

NewList returns a new List representing the blocklist at source.

func (*List) Run

func (l *List) Run(db ListDB, stop <-chan struct{}, poke chan<- struct{})

Run periodically downloads the blocklist and updates the internal database.

type ListDB

type ListDB interface {
	LastFetched(string) time.Time
	Update(string, time.Time, []string) error
}

ListDB is the persistent store of blocklist data.

type MemoryDB

type MemoryDB struct {
	// contains filtered or unexported fields
}

MemoryDB is an in-memory store of blocklist data.

func NewMemoryDB

func NewMemoryDB() *MemoryDB

NewMemoryDB returns a new MemoryDB. A client must call Pokee on a separate goroutine.

func (*MemoryDB) Block

func (db *MemoryDB) Block(domain string) bool

Block returns true if domain is blocked.

func (*MemoryDB) LastFetched

func (db *MemoryDB) LastFetched(source string) time.Time

LastFetched returns the time that the given source was last fetched, or the zero time if it has never been fetched.

func (*MemoryDB) Pokee

func (db *MemoryDB) Pokee(stop, poke <-chan struct{})

func (*MemoryDB) Update

func (db *MemoryDB) Update(source string, fetched time.Time, blocked []string) error

Update sets the contents of the source to blocked as of time fetched.