dns

Documentation

Overview

Package dns provides dns server implementation.

Index

• Variables
• func NewTCPListener(network, addr string, control ControlFn) (net.Listener, error)
• func NewUDPPacketConn(network, addr string, control ControlFn) (net.PacketConn, error)
• type AddressPair
  • func (a AddressPair) String() string
• type Cache
  • func NewCache(next plugin.Handler, l *zap.Logger) *Cache
  • func (c *Cache) ServeDNS(wr dns.ResponseWriter, msg *dns.Msg)
• type ControlFn
  • func MakeControl(network string, forwardEnabled bool) (ControlFn, error)
• type Handler
  • func NewHandler(logger *zap.Logger) *Handler
  • func (h *Handler) Name() string
  • func (h *Handler) ServeDNS(ctx context.Context, wrt dns.ResponseWriter, msg *dns.Msg) (int, error)
  • func (h *Handler) SetProxy(prxs iter.Seq[*proxy.Proxy]) bool
  • func (h *Handler) Stop()
• type HostMapper
• type Manager
  • func NewManager(mr MemberReader, hook suture.EventHook, logger *zap.Logger) *Manager
  • func (m *Manager) AllowNodeResolving(enabled bool)
  • func (m *Manager) ClearAll(dry bool) error
  • func (m *Manager) Done() <-chan error
  • func (m *Manager) RunAll(pairs iter.Seq[AddressPair], forwardEnabled bool) iter.Seq2[RunResult, error]
  • func (m *Manager) ServeBackground(ctx context.Context)
  • func (m *Manager) SetUpstreams(prxs iter.Seq[*proxy.Proxy]) bool
• type MemberReader
• type NodeHandler
  • func NewNodeHandler(next plugin.Handler, hostMapper HostMapper, logger *zap.Logger) *NodeHandler
  • func (h *NodeHandler) Name() string
  • func (h *NodeHandler) ServeDNS(ctx context.Context, wrt dns.ResponseWriter, msg *dns.Msg) (int, error)
  • func (h *NodeHandler) SetEnabled(enabled bool)
• type RunResult
• type Runner
  • func NewRunner(opts RunnerOptions, l *zap.Logger) *Runner
  • func (r *Runner) Serve(ctx context.Context) error
• type RunnerOptions
• type Status

Variables

var ErrCreatingRunner = errors.New("error creating runner")

ErrCreatingRunner is an error that occurs when creating a runner.

Functions

func NewTCPListener

func NewTCPListener(network, addr string, control ControlFn) (net.Listener, error)

NewTCPListener creates a new TCP listener.

func NewUDPPacketConn

func NewUDPPacketConn(network, addr string, control ControlFn) (net.PacketConn, error)

NewUDPPacketConn creates a new UDP packet connection.

Types

type AddressPair

type AddressPair struct {
	Network string
	Addr    netip.AddrPort
}

AddressPair represents a network and address with port.

func (AddressPair) String

func (a AddressPair) String() string

String returns a string representation of the address pair.

type Cache

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

Cache is a dns.Handler to plugin.Handler adapter.

func NewCache

func NewCache(next plugin.Handler, l *zap.Logger) *Cache

NewCache creates a new Cache.

func (*Cache) ServeDNS

func (c *Cache) ServeDNS(wr dns.ResponseWriter, msg *dns.Msg)

ServeDNS implements dns.Handler.

type ControlFn

type ControlFn = func(string, string, syscall.RawConn) error

ControlFn is an alias to net.ListenConfig.Control function.

func MakeControl

func MakeControl(network string, forwardEnabled bool) (ControlFn, error)

MakeControl creates a control function for setting socket options.

type Handler

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

Handler is a dns proxy selector.

func NewHandler

func NewHandler(logger *zap.Logger) *Handler

NewHandler creates a new Handler.

func (*Handler) Name

func (h *Handler) Name() string

Name implements plugin.Handler.

func (*Handler) ServeDNS

func (h *Handler) ServeDNS(ctx context.Context, wrt dns.ResponseWriter, msg *dns.Msg) (int, error)

ServeDNS implements plugin.Handler.

func (*Handler) SetProxy

func (h *Handler) SetProxy(prxs iter.Seq[*proxy.Proxy]) bool

SetProxy sets destination dns proxy servers.

func (*Handler) Stop

func (h *Handler) Stop()

Stop stops and clears dns proxy selector.

type HostMapper

type HostMapper interface {
	ResolveAddr(ctx context.Context, qType uint16, name string) (iter.Seq[netip.Addr], bool)
}

HostMapper is a name to node mapper.

type Manager

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

Manager manages DNS runners.

func NewManager

func NewManager(mr MemberReader, hook suture.EventHook, logger *zap.Logger) *Manager

NewManager creates a new manager.

func (*Manager) AllowNodeResolving

func (m *Manager) AllowNodeResolving(enabled bool)

AllowNodeResolving enables or disables the node resolving feature.

func (*Manager) ClearAll

func (m *Manager) ClearAll(dry bool) error

ClearAll stops and removes all runners. It returns an iterator which yields the address pairs that were removed and/or errors that occurred during the removal process. It's mandatory to range over the iterator to ensure all runners are stopped.

func (*Manager) Done

func (m *Manager) Done() <-chan error

Done reports if superwisor finished execution.

func (*Manager) RunAll

func (m *Manager) RunAll(pairs iter.Seq[AddressPair], forwardEnabled bool) iter.Seq2[RunResult, error]

RunAll updates and run the runners managed by the manager. It returns an iterator which yields the address pairs for all running and attempted ro run configurations. It's mandatory to range over the iterator to ensure all runners are updated.

func (*Manager) ServeBackground

func (m *Manager) ServeBackground(ctx context.Context)

ServeBackground starts the manager in the background. It panics if the manager is not initialized or if it's called more than once.

func (*Manager) SetUpstreams

func (m *Manager) SetUpstreams(prxs iter.Seq[*proxy.Proxy]) bool

SetUpstreams sets the upstreams for the DNS handler. It returns true if the upstreams were updated, false otherwise.

type MemberReader

type MemberReader interface {
	ReadMembers(ctx context.Context) (iter.Seq[*cluster.Member], error)
}

MemberReader is an interface to read members.

type NodeHandler

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

NodeHandler try to resolve dns request to a node. If required node is not found, it will move to the next handler.

func NewNodeHandler

func NewNodeHandler(next plugin.Handler, hostMapper HostMapper, logger *zap.Logger) *NodeHandler

NewNodeHandler creates a new NodeHandler.

func (*NodeHandler) Name

func (h *NodeHandler) Name() string

Name implements plugin.Handler.

func (*NodeHandler) ServeDNS

func (h *NodeHandler) ServeDNS(ctx context.Context, wrt dns.ResponseWriter, msg *dns.Msg) (int, error)

ServeDNS implements plugin.Handler.

func (*NodeHandler) SetEnabled

func (h *NodeHandler) SetEnabled(enabled bool)

SetEnabled sets the handler enabled state.

type RunResult

type RunResult struct {
	AddressPair
	Status Status
}

RunResult represents the result of a RunAll iteration.

type Runner

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

Runner is a DNS server runner.

func NewRunner

func NewRunner(opts RunnerOptions, l *zap.Logger) *Runner

NewRunner creates a new Runner.

func (*Runner) Serve

func (r *Runner) Serve(ctx context.Context) error

Serve starts the DNS server.

type RunnerOptions

type RunnerOptions struct {
	Listener      net.Listener
	PacketConn    net.PacketConn
	Handler       dns.Handler
	ReadTimeout   time.Duration
	WriteTimeout  time.Duration
	IdleTimeout   func() time.Duration
	MaxTCPQueries int
}

RunnerOptions is a Runner options.

type Status

type Status int

Status represents the status of a runner.

const (
	// StatusNew represents a new runner.
	StatusNew Status = iota
	// StatusRunning represents a already running runner.
	StatusRunning
	// StatusRemoved represents a removed runner.
	StatusRemoved
)