zolfa
/
tendermint


								package p2p


								import (

									"context"

									"errors"

									"fmt"

									"net"


									"github.com/tendermint/tendermint/crypto"

									"github.com/tendermint/tendermint/p2p/conn"

								)


								const (

									// defaultProtocol is the default protocol used for NodeAddress when

									// a protocol isn't explicitly given as a URL scheme.

									defaultProtocol Protocol = MConnProtocol

								)


								// Protocol identifies a transport protocol.

								type Protocol string


								// Transport is a connection-oriented mechanism for exchanging data with a peer.

								type Transport interface {

									// Protocols returns the protocols supported by the transport. The Router

									// uses this to pick a transport for an Endpoint.

									Protocols() []Protocol


									// Endpoints returns the local endpoints the transport is listening on, if any.

									//

									// How to listen is transport-dependent, e.g. MConnTransport uses Listen() while

									// MemoryTransport starts listening via MemoryNetwork.CreateTransport().

									Endpoints() []Endpoint


									// Accept waits for the next inbound connection on a listening endpoint, blocking

									// until either a connection is available or the transport is closed. On closure,

									// io.EOF is returned and further Accept calls are futile.

									Accept() (Connection, error)


									// Dial creates an outbound connection to an endpoint.

									Dial(context.Context, Endpoint) (Connection, error)


									// Close stops accepting new connections, but does not close active connections.

									Close() error


									// Stringer is used to display the transport, e.g. in logs.

									//

									// Without this, the logger may use reflection to access and display

									// internal fields. These can be written to concurrently, which can trigger

									// the race detector or even cause a panic.

									fmt.Stringer

								}


								// Connection represents an established connection between two endpoints.

								//

								// FIXME: This is a temporary interface for backwards-compatibility with the

								// current MConnection-protocol, which is message-oriented. It should be

								// migrated to a byte-oriented multi-stream interface instead, which would allow

								// e.g. adopting QUIC and making message framing, traffic scheduling, and node

								// handshakes a Router concern shared across all transports. However, this

								// requires MConnection protocol changes or a shim. For details, see:

								// https://github.com/tendermint/spec/pull/227

								//

								// FIXME: The interface is currently very broad in order to accommodate

								// MConnection behavior that the legacy P2P stack relies on. It should be

								// cleaned up when the legacy stack is removed.

								type Connection interface {

									// Handshake executes a node handshake with the remote peer. It must be

									// called immediately after the connection is established, and returns the

									// remote peer's node info and public key. The caller is responsible for

									// validation.

									//

									// FIXME: The handshake should really be the Router's responsibility, but

									// that requires the connection interface to be byte-oriented rather than

									// message-oriented (see comment above).

									Handshake(context.Context, NodeInfo, crypto.PrivKey) (NodeInfo, crypto.PubKey, error)


									// ReceiveMessage returns the next message received on the connection,

									// blocking until one is available. Returns io.EOF if closed.

									ReceiveMessage() (ChannelID, []byte, error)


									// SendMessage sends a message on the connection. Returns io.EOF if closed.

									//

									// FIXME: For compatibility with the legacy P2P stack, it returns an

									// additional boolean false if the message timed out waiting to be accepted

									// into the send buffer. This should be removed.

									SendMessage(ChannelID, []byte) (bool, error)


									// TrySendMessage is a non-blocking version of SendMessage that returns

									// immediately if the message buffer is full. It returns true if the message

									// was accepted.

									//

									// FIXME: This method is here for backwards-compatibility with the legacy

									// P2P stack and should be removed.

									TrySendMessage(ChannelID, []byte) (bool, error)


									// LocalEndpoint returns the local endpoint for the connection.

									LocalEndpoint() Endpoint


									// RemoteEndpoint returns the remote endpoint for the connection.

									RemoteEndpoint() Endpoint


									// Close closes the connection.

									Close() error


									// FlushClose flushes all pending sends and then closes the connection.

									//

									// FIXME: This only exists for backwards-compatibility with the current

									// MConnection implementation. There should really be a separate Flush()

									// method, but there is no easy way to synchronously flush pending data with

									// the current MConnection code.

									FlushClose() error


									// Status returns the current connection status.

									// FIXME: Only here for compatibility with the current Peer code.

									Status() conn.ConnectionStatus


									// Stringer is used to display the connection, e.g. in logs.

									//

									// Without this, the logger may use reflection to access and display

									// internal fields. These can be written to concurrently, which can trigger

									// the race detector or even cause a panic.

									fmt.Stringer

								}


								// Endpoint represents a transport connection endpoint, either local or remote.

								//

								// Endpoints are not necessarily networked (see e.g. MemoryTransport) but all

								// networked endpoints must use IP as the underlying transport protocol to allow

								// e.g. IP address filtering. Either IP or Path (or both) must be set.

								type Endpoint struct {

									// Protocol specifies the transport protocol.

									Protocol Protocol


									// IP is an IP address (v4 or v6) to connect to. If set, this defines the

									// endpoint as a networked endpoint.

									IP net.IP


									// Port is a network port (either TCP or UDP). If 0, a default port may be

									// used depending on the protocol.

									Port uint16


									// Path is an optional transport-specific path or identifier.

									Path string

								}


								// NodeAddress converts the endpoint into a NodeAddress for the given node ID.

								func (e Endpoint) NodeAddress(nodeID NodeID) NodeAddress {

									address := NodeAddress{

										NodeID:   nodeID,

										Protocol: e.Protocol,

										Path:     e.Path,

									}

									if len(e.IP) > 0 {

										address.Hostname = e.IP.String()

										address.Port = e.Port

									}

									return address

								}


								// String formats the endpoint as a URL string.

								func (e Endpoint) String() string {

									// If this is a non-networked endpoint with a valid node ID as a path,

									// assume that path is a node ID (to handle opaque URLs of the form

									// scheme:id).

									if e.IP == nil {

										if nodeID, err := NewNodeID(e.Path); err == nil {

											return e.NodeAddress(nodeID).String()

										}

									}

									return e.NodeAddress("").String()

								}


								// Validate validates the endpoint.

								func (e Endpoint) Validate() error {

									switch {

									case e.Protocol == "":

										return errors.New("endpoint has no protocol")


									case len(e.IP) > 0 && e.IP.To16() == nil:

										return fmt.Errorf("invalid IP address %v", e.IP)


									case e.Port > 0 && len(e.IP) == 0:

										return fmt.Errorf("endpoint has port %v but no IP", e.Port)


									case len(e.IP) == 0 && e.Path == "":

										return errors.New("endpoint has neither path nor IP")


									default:

										return nil

									}

								}