dns_handler

Documentation

Index

• type DefaultHandler
  • func (h *DefaultHandler) ServeDNS(ctx context.Context, req *dns.Msg, w ResponseWriter, meta *handler.RequestMeta) error
• type DummyServerHandler
  • func (d *DummyServerHandler) ServeDNS(_ context.Context, req *dns.Msg, w ResponseWriter, meta *handler.RequestMeta) error
• type Handler
• type ResponseWriter

Types

type DefaultHandler

type DefaultHandler struct {
	// Logger is used for logging. A nil value will disable logging.
	Logger *zap.Logger

	// Entry is the entry ExecutablePlugin's tag. This cannot be nil.
	Entry handler.ExecutableChainNode

	// QueryTimeout limits the timeout value of each query.
	// Default is defaultQueryTimeout.
	QueryTimeout time.Duration

	// ConcurrentLimit controls the max concurrent queries for the DefaultHandler.
	// If ConcurrentLimit <= 0, means no limit.
	// When calling DefaultHandler.ServeDNS(), if a query exceeds the limit, it will wait on a FIFO queue until
	// - its ctx is done or currently there are more than 8 x ConcurrentLimit queries waiting -> The query will be dropped silently.
	// - it can be proceeded -> Normal procedure.
	ConcurrentLimit int

	// RecursionAvailable sets the dns.Msg.RecursionAvailable flag globally.
	RecursionAvailable bool
	// contains filtered or unexported fields
}

func (*DefaultHandler) ServeDNS

func (h *DefaultHandler) ServeDNS(ctx context.Context, req *dns.Msg, w ResponseWriter, meta *handler.RequestMeta) error

ServeDNS implements Handler. If entry returns an error, a SERVFAIL response will be sent back to client. If concurrentLimit is reached, the query will block and wait available token until ctx is done.

type DummyServerHandler

type DummyServerHandler struct {
	T       *testing.T
	WantMsg *dns.Msg
	WantErr error
}

func (*DummyServerHandler) ServeDNS

func (d *DummyServerHandler) ServeDNS(_ context.Context, req *dns.Msg, w ResponseWriter, meta *handler.RequestMeta) error

type Handler

type Handler interface {
	// ServeDNS handles r and writes response to w.
	// Implements must not keep and use req after the ServeDNS returned.
	// ServeDNS should handle errors by itself and sends properly error responses
	// to clients.
	// If ServeDNS returns an error, caller considers that the error is associated
	// with the downstream connection and will close the downstream connection
	// immediately.
	ServeDNS(ctx context.Context, req *dns.Msg, w ResponseWriter, meta *handler.RequestMeta) error
}

Handler handles dns query.

type ResponseWriter

type ResponseWriter interface {
	Write(m *dns.Msg) error
}

ResponseWriter can write msg to the client.