micro/tunnel/tunnel.go
2020-08-10 17:31:21 +01:00

104 lines
3.2 KiB
Go

// Package tunnel provides gre network tunnelling
package tunnel
import (
"errors"
"time"
"github.com/micro/go-micro/v3/transport"
)
const (
// send over one link
Unicast Mode = iota
// send to all channel listeners
Multicast
// send to all links
Broadcast
)
var (
// DefaultDialTimeout is the dial timeout if none is specified
DefaultDialTimeout = time.Second * 5
// ErrDialTimeout is returned by a call to Dial where the timeout occurs
ErrDialTimeout = errors.New("dial timeout")
// ErrDiscoverChan is returned when we failed to receive the "announce" back from a discovery
ErrDiscoverChan = errors.New("failed to discover channel")
// ErrLinkNotFound is returned when a link is specified at dial time and does not exist
ErrLinkNotFound = errors.New("link not found")
// ErrLinkDisconnected is returned when a link we attempt to send to is disconnected
ErrLinkDisconnected = errors.New("link not connected")
// ErrLinkLoppback is returned when attempting to send an outbound message over loopback link
ErrLinkLoopback = errors.New("link is loopback")
// ErrLinkRemote is returned when attempting to send a loopback message over remote link
ErrLinkRemote = errors.New("link is remote")
// ErrReadTimeout is a timeout on session.Recv
ErrReadTimeout = errors.New("read timeout")
// ErrDecryptingData is for when theres a nonce error
ErrDecryptingData = errors.New("error decrypting data")
)
// Mode of the session
type Mode uint8
// Tunnel creates a gre tunnel on top of the go-micro/transport.
// It establishes multiple streams using the Micro-Tunnel-Channel header
// and Micro-Tunnel-Session header. The tunnel id is a hash of
// the address being requested.
type Tunnel interface {
// Init initializes tunnel with options
Init(opts ...Option) error
// Address returns the address the tunnel is listening on
Address() string
// Connect connects the tunnel
Connect() error
// Close closes the tunnel
Close() error
// Links returns all the links the tunnel is connected to
Links() []Link
// Dial allows a client to connect to a channel
Dial(channel string, opts ...DialOption) (Session, error)
// Listen allows to accept connections on a channel
Listen(channel string, opts ...ListenOption) (Listener, error)
// String returns the name of the tunnel implementation
String() string
}
// Link represents internal links to the tunnel
type Link interface {
// Id returns the link unique Id
Id() string
// Delay is the current load on the link (lower is better)
Delay() int64
// Length returns the roundtrip time as nanoseconds (lower is better)
Length() int64
// Current transfer rate as bits per second (lower is better)
Rate() float64
// Is this a loopback link
Loopback() bool
// State of the link: connected/closed/error
State() string
// honours transport socket
transport.Socket
}
// The listener provides similar constructs to the transport.Listener
type Listener interface {
Accept() (Session, error)
Channel() string
Close() error
}
// Session is a unique session created when dialling or accepting connections on the tunnel
type Session interface {
// The unique session id
Id() string
// The channel name
Channel() string
// The link the session is on
Link() string
// a transport socket
transport.Socket
}