status-go/vendor/github.com/multiformats/go-multiaddr/net/net.go

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// Package manet provides Multiaddr
// (https://github.com/multiformats/go-multiaddr) specific versions of common
// functions in Go's standard `net` package. This means wrappers of standard
// net symbols like `net.Dial` and `net.Listen`, as well as conversion to
// and from `net.Addr`.
package manet
import (
"context"
"fmt"
"net"
ma "github.com/multiformats/go-multiaddr"
)
// Conn is the equivalent of a net.Conn object. It is the
// result of calling the Dial or Listen functions in this
// package, with associated local and remote Multiaddrs.
type Conn interface {
net.Conn
// LocalMultiaddr returns the local Multiaddr associated
// with this connection
LocalMultiaddr() ma.Multiaddr
// RemoteMultiaddr returns the remote Multiaddr associated
// with this connection
RemoteMultiaddr() ma.Multiaddr
}
type halfOpen interface {
net.Conn
CloseRead() error
CloseWrite() error
}
func wrap(nconn net.Conn, laddr, raddr ma.Multiaddr) Conn {
endpts := maEndpoints{
laddr: laddr,
raddr: raddr,
}
// This sucks. However, it's the only way to reliably expose the
// underlying methods. This way, users that need access to, e.g.,
// CloseRead and CloseWrite, can do so via type assertions.
switch nconn := nconn.(type) {
case *net.TCPConn:
return &struct {
*net.TCPConn
maEndpoints
}{nconn, endpts}
case *net.UDPConn:
return &struct {
*net.UDPConn
maEndpoints
}{nconn, endpts}
case *net.IPConn:
return &struct {
*net.IPConn
maEndpoints
}{nconn, endpts}
case *net.UnixConn:
return &struct {
*net.UnixConn
maEndpoints
}{nconn, endpts}
case halfOpen:
return &struct {
halfOpen
maEndpoints
}{nconn, endpts}
default:
return &struct {
net.Conn
maEndpoints
}{nconn, endpts}
}
}
// WrapNetConn wraps a net.Conn object with a Multiaddr friendly Conn.
//
// This function does it's best to avoid "hiding" methods exposed by the wrapped
// type. Guarantees:
//
// * If the wrapped connection exposes the "half-open" closer methods
// (CloseWrite, CloseRead), these will be available on the wrapped connection
// via type assertions.
// * If the wrapped connection is a UnixConn, IPConn, TCPConn, or UDPConn, all
// methods on these wrapped connections will be available via type assertions.
func WrapNetConn(nconn net.Conn) (Conn, error) {
if nconn == nil {
return nil, fmt.Errorf("failed to convert nconn.LocalAddr: nil")
}
laddr, err := FromNetAddr(nconn.LocalAddr())
if err != nil {
return nil, fmt.Errorf("failed to convert nconn.LocalAddr: %s", err)
}
raddr, err := FromNetAddr(nconn.RemoteAddr())
if err != nil {
return nil, fmt.Errorf("failed to convert nconn.RemoteAddr: %s", err)
}
return wrap(nconn, laddr, raddr), nil
}
type maEndpoints struct {
laddr ma.Multiaddr
raddr ma.Multiaddr
}
// LocalMultiaddr returns the local address associated with
// this connection
func (c *maEndpoints) LocalMultiaddr() ma.Multiaddr {
return c.laddr
}
// RemoteMultiaddr returns the remote address associated with
// this connection
func (c *maEndpoints) RemoteMultiaddr() ma.Multiaddr {
return c.raddr
}
// Dialer contains options for connecting to an address. It
// is effectively the same as net.Dialer, but its LocalAddr
// and RemoteAddr options are Multiaddrs, instead of net.Addrs.
type Dialer struct {
// Dialer is just an embedded net.Dialer, with all its options.
net.Dialer
// LocalAddr is the local address to use when dialing an
// address. The address must be of a compatible type for the
// network being dialed.
// If nil, a local address is automatically chosen.
LocalAddr ma.Multiaddr
}
// Dial connects to a remote address, using the options of the
// Dialer. Dialer uses an underlying net.Dialer to Dial a
// net.Conn, then wraps that in a Conn object (with local and
// remote Multiaddrs).
func (d *Dialer) Dial(remote ma.Multiaddr) (Conn, error) {
return d.DialContext(context.Background(), remote)
}
// DialContext allows to provide a custom context to Dial().
func (d *Dialer) DialContext(ctx context.Context, remote ma.Multiaddr) (Conn, error) {
// if a LocalAddr is specified, use it on the embedded dialer.
if d.LocalAddr != nil {
// convert our multiaddr to net.Addr friendly
naddr, err := ToNetAddr(d.LocalAddr)
if err != nil {
return nil, err
}
// set the dialer's LocalAddr as naddr
d.Dialer.LocalAddr = naddr
}
// get the net.Dial friendly arguments from the remote addr
rnet, rnaddr, err := DialArgs(remote)
if err != nil {
return nil, err
}
// ok, Dial!
var nconn net.Conn
switch rnet {
case "tcp", "tcp4", "tcp6", "udp", "udp4", "udp6", "unix":
nconn, err = d.Dialer.DialContext(ctx, rnet, rnaddr)
if err != nil {
return nil, err
}
default:
return nil, fmt.Errorf("unrecognized network: %s", rnet)
}
// get local address (pre-specified or assigned within net.Conn)
local := d.LocalAddr
// This block helps us avoid parsing addresses in transports (such as unix
// sockets) that don't have local addresses when dialing out.
if local == nil && nconn.LocalAddr().String() != "" {
local, err = FromNetAddr(nconn.LocalAddr())
if err != nil {
return nil, err
}
}
return wrap(nconn, local, remote), nil
}
// Dial connects to a remote address. It uses an underlying net.Conn,
// then wraps it in a Conn object (with local and remote Multiaddrs).
func Dial(remote ma.Multiaddr) (Conn, error) {
return (&Dialer{}).Dial(remote)
}
// A Listener is a generic network listener for stream-oriented protocols.
// it uses an embedded net.Listener, overriding net.Listener.Accept to
// return a Conn and providing Multiaddr.
type Listener interface {
// Accept waits for and returns the next connection to the listener.
// Returns a Multiaddr friendly Conn
Accept() (Conn, error)
// Close closes the listener.
// Any blocked Accept operations will be unblocked and return errors.
Close() error
// Multiaddr returns the listener's (local) Multiaddr.
Multiaddr() ma.Multiaddr
// Addr returns the net.Listener's network address.
Addr() net.Addr
}
type netListenerAdapter struct {
Listener
}
func (nla *netListenerAdapter) Accept() (net.Conn, error) {
return nla.Listener.Accept()
}
// NetListener turns this Listener into a net.Listener.
//
// * Connections returned from Accept implement multiaddr/net Conn.
// * Calling WrapNetListener on the net.Listener returned by this function will
// return the original (underlying) multiaddr/net Listener.
func NetListener(l Listener) net.Listener {
return &netListenerAdapter{l}
}
// maListener implements Listener
type maListener struct {
net.Listener
laddr ma.Multiaddr
}
// Accept waits for and returns the next connection to the listener.
// Returns a Multiaddr friendly Conn
func (l *maListener) Accept() (Conn, error) {
nconn, err := l.Listener.Accept()
if err != nil {
return nil, err
}
var raddr ma.Multiaddr
// This block protects us in transports (i.e. unix sockets) that don't have
// remote addresses for inbound connections.
if nconn.RemoteAddr().String() != "" {
raddr, err = FromNetAddr(nconn.RemoteAddr())
if err != nil {
return nil, fmt.Errorf("failed to convert conn.RemoteAddr: %s", err)
}
}
var laddr ma.Multiaddr
if nconn.LocalAddr().String() != "" {
laddr, err = FromNetAddr(nconn.LocalAddr())
if err != nil {
return nil, fmt.Errorf("failed to convert conn.LocalAddr: %s", err)
}
}
return wrap(nconn, laddr, raddr), nil
}
// Multiaddr returns the listener's (local) Multiaddr.
func (l *maListener) Multiaddr() ma.Multiaddr {
return l.laddr
}
// Addr returns the listener's network address.
func (l *maListener) Addr() net.Addr {
return l.Listener.Addr()
}
// Listen announces on the local network address laddr.
// The Multiaddr must be a "ThinWaist" stream-oriented network:
// ip4/tcp, ip6/tcp, (TODO: unix, unixpacket)
// See Dial for the syntax of laddr.
func Listen(laddr ma.Multiaddr) (Listener, error) {
// get the net.Listen friendly arguments from the remote addr
lnet, lnaddr, err := DialArgs(laddr)
if err != nil {
return nil, err
}
nl, err := net.Listen(lnet, lnaddr)
if err != nil {
return nil, err
}
// we want to fetch the new multiaddr from the listener, as it may
// have resolved to some other value. WrapNetListener does it for us.
return WrapNetListener(nl)
}
// WrapNetListener wraps a net.Listener with a manet.Listener.
func WrapNetListener(nl net.Listener) (Listener, error) {
if nla, ok := nl.(*netListenerAdapter); ok {
return nla.Listener, nil
}
laddr, err := FromNetAddr(nl.Addr())
if err != nil {
return nil, err
}
return &maListener{
Listener: nl,
laddr: laddr,
}, nil
}
// A PacketConn is a generic packet oriented network connection which uses an
// underlying net.PacketConn, wrapped with the locally bound Multiaddr.
type PacketConn interface {
net.PacketConn
LocalMultiaddr() ma.Multiaddr
ReadFromMultiaddr(b []byte) (int, ma.Multiaddr, error)
WriteToMultiaddr(b []byte, maddr ma.Multiaddr) (int, error)
}
// maPacketConn implements PacketConn
type maPacketConn struct {
net.PacketConn
laddr ma.Multiaddr
}
var _ PacketConn = (*maPacketConn)(nil)
// LocalMultiaddr returns the bound local Multiaddr.
func (l *maPacketConn) LocalMultiaddr() ma.Multiaddr {
return l.laddr
}
func (l *maPacketConn) ReadFromMultiaddr(b []byte) (int, ma.Multiaddr, error) {
n, addr, err := l.ReadFrom(b)
maddr, _ := FromNetAddr(addr)
return n, maddr, err
}
func (l *maPacketConn) WriteToMultiaddr(b []byte, maddr ma.Multiaddr) (int, error) {
addr, err := ToNetAddr(maddr)
if err != nil {
return 0, err
}
return l.WriteTo(b, addr)
}
// ListenPacket announces on the local network address laddr.
// The Multiaddr must be a packet driven network, like udp4 or udp6.
// See Dial for the syntax of laddr.
func ListenPacket(laddr ma.Multiaddr) (PacketConn, error) {
lnet, lnaddr, err := DialArgs(laddr)
if err != nil {
return nil, err
}
pc, err := net.ListenPacket(lnet, lnaddr)
if err != nil {
return nil, err
}
// We want to fetch the new multiaddr from the listener, as it may
// have resolved to some other value. WrapPacketConn does this.
return WrapPacketConn(pc)
}
// WrapPacketConn wraps a net.PacketConn with a manet.PacketConn.
func WrapPacketConn(pc net.PacketConn) (PacketConn, error) {
laddr, err := FromNetAddr(pc.LocalAddr())
if err != nil {
return nil, err
}
return &maPacketConn{
PacketConn: pc,
laddr: laddr,
}, nil
}
// InterfaceMultiaddrs will return the addresses matching net.InterfaceAddrs
func InterfaceMultiaddrs() ([]ma.Multiaddr, error) {
addrs, err := net.InterfaceAddrs()
if err != nil {
return nil, err
}
maddrs := make([]ma.Multiaddr, len(addrs))
for i, a := range addrs {
maddrs[i], err = FromNetAddr(a)
if err != nil {
return nil, err
}
}
return maddrs, nil
}
// AddrMatch returns the Multiaddrs that match the protocol stack on addr
func AddrMatch(match ma.Multiaddr, addrs []ma.Multiaddr) []ma.Multiaddr {
// we should match transports entirely.
p1s := match.Protocols()
out := make([]ma.Multiaddr, 0, len(addrs))
for _, a := range addrs {
p2s := a.Protocols()
if len(p1s) != len(p2s) {
continue
}
match := true
for i, p2 := range p2s {
if p1s[i].Code != p2.Code {
match = false
break
}
}
if match {
out = append(out, a)
}
}
return out
}