derphttp

Documentation

Overview

Package derphttp implements DERP-over-HTTP.

This makes DERP look exactly like WebSockets. A server can implement DERP over HTTPS and even if the TLS connection intercepted using a fake root CA, unless the interceptor knows how to detect DERP packets, it will look like a web socket.

Index

• Variables
• func Handler(s *derp.Server) http.Handler
• type Client
  • func NewClient(privateKey key.Private, serverURL string, logf logger.Logf) (*Client, error)
  • func NewNetcheckClient(logf logger.Logf) *Client
  • func NewRegionClient(privateKey key.Private, logf logger.Logf, getRegion func() *tailcfg.DERPRegion) *Client
  • func (c *Client) Close() error
  • func (c *Client) Connect(ctx context.Context) error
  • func (c *Client) DialRegionTLS(ctx context.Context, reg *tailcfg.DERPRegion) (tlsConn *tls.Conn, connClose io.Closer, err error)
  • func (c *Client) NotePreferred(v bool)
  • func (c *Client) Recv(b []byte) (derp.ReceivedMessage, error)
  • func (c *Client) Send(dstKey key.Public, b []byte) error

Variables

var ErrClientClosed = errors.New("derphttp.Client closed")

Functions

func Handler

func Handler(s *derp.Server) http.Handler

Types

type Client

type Client struct {
	TLSConfig *tls.Config        // optional; nil means default
	DNSCache  *dnscache.Resolver // optional; nil means no caching
	// contains filtered or unexported fields
}

Client is a DERP-over-HTTP client.

It automatically reconnects on error retry. That is, a failed Send or Recv will report the error and not retry, but subsequent calls to Send/Recv will completely re-establish the connection (unless Close has been called).

func NewClient

func NewClient(privateKey key.Private, serverURL string, logf logger.Logf) (*Client, error)

NewClient returns a new DERP-over-HTTP client. It connects lazily. To trigger a connection, use Connect.

func NewNetcheckClient

func NewNetcheckClient(logf logger.Logf) *Client

NewNetcheckClient returns a Client that's only able to have its DialRegion method called. It's used by the netcheck package.

func NewRegionClient

func NewRegionClient(privateKey key.Private, logf logger.Logf, getRegion func() *tailcfg.DERPRegion) *Client

NewRegionClient returns a new DERP-over-HTTP client. It connects lazily. To trigger a connection, use Connect.

func (*Client) Close

func (c *Client) Close() error

Close closes the client. It will not automatically reconnect after being closed.

func (*Client) Connect

func (c *Client) Connect(ctx context.Context) error

Connect connects or reconnects to the server, unless already connected. It returns nil if there was already a good connection, or if one was made.

func (*Client) DialRegionTLS

func (c *Client) DialRegionTLS(ctx context.Context, reg *tailcfg.DERPRegion) (tlsConn *tls.Conn, connClose io.Closer, err error)

func (*Client) NotePreferred

func (c *Client) NotePreferred(v bool)

NotePreferred notes whether this Client is the caller's preferred (home) DERP node. It's only used for stats.

func (*Client) Recv

func (c *Client) Recv(b []byte) (derp.ReceivedMessage, error)

func (*Client) Send

func (c *Client) Send(dstKey key.Public, b []byte) error