1 files changed, 349 insertions, 0 deletions
diff --git a/src/net/unixsock.go b/src/net/unixsock.go
new file mode 100644
index 0000000..821be7b
--- /dev/null
+++ b/src/net/unixsock.go
@@ -0,0 +1,349 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package net
+
+import (
+	"context"
+	"os"
+	"sync"
+	"syscall"
+	"time"
+)
+
+// BUG(mikio): On JS, WASIP1 and Plan 9, methods and functions related
+// to UnixConn and UnixListener are not implemented.
+
+// BUG(mikio): On Windows, methods and functions related to UnixConn
+// and UnixListener don't work for "unixgram" and "unixpacket".
+
+// UnixAddr represents the address of a Unix domain socket end point.
+type UnixAddr struct {
+	Name string
+	Net  string
+}
+
+// Network returns the address's network name, "unix", "unixgram" or
+// "unixpacket".
+func (a *UnixAddr) Network() string {
+	return a.Net
+}
+
+func (a *UnixAddr) String() string {
+	if a == nil {
+		return "<nil>"
+	}
+	return a.Name
+}
+
+func (a *UnixAddr) isWildcard() bool {
+	return a == nil || a.Name == ""
+}
+
+func (a *UnixAddr) opAddr() Addr {
+	if a == nil {
+		return nil
+	}
+	return a
+}
+
+// ResolveUnixAddr returns an address of Unix domain socket end point.
+//
+// The network must be a Unix network name.
+//
+// See func [Dial] for a description of the network and address
+// parameters.
+func ResolveUnixAddr(network, address string) (*UnixAddr, error) {
+	switch network {
+	case "unix", "unixgram", "unixpacket":
+		return &UnixAddr{Name: address, Net: network}, nil
+	default:
+		return nil, UnknownNetworkError(network)
+	}
+}
+
+// UnixConn is an implementation of the [Conn] interface for connections
+// to Unix domain sockets.
+type UnixConn struct {
+	conn
+}
+
+// SyscallConn returns a raw network connection.
+// This implements the [syscall.Conn] interface.
+func (c *UnixConn) SyscallConn() (syscall.RawConn, error) {
+	if !c.ok() {
+		return nil, syscall.EINVAL
+	}
+	return newRawConn(c.fd), nil
+}
+
+// CloseRead shuts down the reading side of the Unix domain connection.
+// Most callers should just use Close.
+func (c *UnixConn) CloseRead() error {
+	if !c.ok() {
+		return syscall.EINVAL
+	}
+	if err := c.fd.closeRead(); err != nil {
+		return &OpError{Op: "close", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err}
+	}
+	return nil
+}
+
+// CloseWrite shuts down the writing side of the Unix domain connection.
+// Most callers should just use Close.
+func (c *UnixConn) CloseWrite() error {
+	if !c.ok() {
+		return syscall.EINVAL
+	}
+	if err := c.fd.closeWrite(); err != nil {
+		return &OpError{Op: "close", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err}
+	}
+	return nil
+}
+
+// ReadFromUnix acts like [UnixConn.ReadFrom] but returns a [UnixAddr].
+func (c *UnixConn) ReadFromUnix(b []byte) (int, *UnixAddr, error) {
+	if !c.ok() {
+		return 0, nil, syscall.EINVAL
+	}
+	n, addr, err := c.readFrom(b)
+	if err != nil {
+		err = &OpError{Op: "read", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err}
+	}
+	return n, addr, err
+}
+
+// ReadFrom implements the [PacketConn] ReadFrom method.
+func (c *UnixConn) ReadFrom(b []byte) (int, Addr, error) {
+	if !c.ok() {
+		return 0, nil, syscall.EINVAL
+	}
+	n, addr, err := c.readFrom(b)
+	if err != nil {
+		err = &OpError{Op: "read", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err}
+	}
+	if addr == nil {
+		return n, nil, err
+	}
+	return n, addr, err
+}
+
+// ReadMsgUnix reads a message from c, copying the payload into b and
+// the associated out-of-band data into oob. It returns the number of
+// bytes copied into b, the number of bytes copied into oob, the flags
+// that were set on the message and the source address of the message.
+//
+// Note that if len(b) == 0 and len(oob) > 0, this function will still
+// read (and discard) 1 byte from the connection.
+func (c *UnixConn) ReadMsgUnix(b, oob []byte) (n, oobn, flags int, addr *UnixAddr, err error) {
+	if !c.ok() {
+		return 0, 0, 0, nil, syscall.EINVAL
+	}
+	n, oobn, flags, addr, err = c.readMsg(b, oob)
+	if err != nil {
+		err = &OpError{Op: "read", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err}
+	}
+	return
+}
+
+// WriteToUnix acts like [UnixConn.WriteTo] but takes a [UnixAddr].
+func (c *UnixConn) WriteToUnix(b []byte, addr *UnixAddr) (int, error) {
+	if !c.ok() {
+		return 0, syscall.EINVAL
+	}
+	n, err := c.writeTo(b, addr)
+	if err != nil {
+		err = &OpError{Op: "write", Net: c.fd.net, Source: c.fd.laddr, Addr: addr.opAddr(), Err: err}
+	}
+	return n, err
+}
+
+// WriteTo implements the [PacketConn] WriteTo method.
+func (c *UnixConn) WriteTo(b []byte, addr Addr) (int, error) {
+	if !c.ok() {
+		return 0, syscall.EINVAL
+	}
+	a, ok := addr.(*UnixAddr)
+	if !ok {
+		return 0, &OpError{Op: "write", Net: c.fd.net, Source: c.fd.laddr, Addr: addr, Err: syscall.EINVAL}
+	}
+	n, err := c.writeTo(b, a)
+	if err != nil {
+		err = &OpError{Op: "write", Net: c.fd.net, Source: c.fd.laddr, Addr: a.opAddr(), Err: err}
+	}
+	return n, err
+}
+
+// WriteMsgUnix writes a message to addr via c, copying the payload
+// from b and the associated out-of-band data from oob. It returns the
+// number of payload and out-of-band bytes written.
+//
+// Note that if len(b) == 0 and len(oob) > 0, this function will still
+// write 1 byte to the connection.
+func (c *UnixConn) WriteMsgUnix(b, oob []byte, addr *UnixAddr) (n, oobn int, err error) {
+	if !c.ok() {
+		return 0, 0, syscall.EINVAL
+	}
+	n, oobn, err = c.writeMsg(b, oob, addr)
+	if err != nil {
+		err = &OpError{Op: "write", Net: c.fd.net, Source: c.fd.laddr, Addr: addr.opAddr(), Err: err}
+	}
+	return
+}
+
+func newUnixConn(fd *netFD) *UnixConn { return &UnixConn{conn{fd}} }
+
+// DialUnix acts like [Dial] for Unix networks.
+//
+// The network must be a Unix network name; see func Dial for details.
+//
+// If laddr is non-nil, it is used as the local address for the
+// connection.
+func DialUnix(network string, laddr, raddr *UnixAddr) (*UnixConn, error) {
+	switch network {
+	case "unix", "unixgram", "unixpacket":
+	default:
+		return nil, &OpError{Op: "dial", Net: network, Source: laddr.opAddr(), Addr: raddr.opAddr(), Err: UnknownNetworkError(network)}
+	}
+	sd := &sysDialer{network: network, address: raddr.String()}
+	c, err := sd.dialUnix(context.Background(), laddr, raddr)
+	if err != nil {
+		return nil, &OpError{Op: "dial", Net: network, Source: laddr.opAddr(), Addr: raddr.opAddr(), Err: err}
+	}
+	return c, nil
+}
+
+// UnixListener is a Unix domain socket listener. Clients should
+// typically use variables of type [Listener] instead of assuming Unix
+// domain sockets.
+type UnixListener struct {
+	fd         *netFD
+	path       string
+	unlink     bool
+	unlinkOnce sync.Once
+}
+
+func (ln *UnixListener) ok() bool { return ln != nil && ln.fd != nil }
+
+// SyscallConn returns a raw network connection.
+// This implements the [syscall.Conn] interface.
+//
+// The returned RawConn only supports calling Control. Read and
+// Write return an error.
+func (l *UnixListener) SyscallConn() (syscall.RawConn, error) {
+	if !l.ok() {
+		return nil, syscall.EINVAL
+	}
+	return newRawListener(l.fd), nil
+}
+
+// AcceptUnix accepts the next incoming call and returns the new
+// connection.
+func (l *UnixListener) AcceptUnix() (*UnixConn, error) {
+	if !l.ok() {
+		return nil, syscall.EINVAL
+	}
+	c, err := l.accept()
+	if err != nil {
+		return nil, &OpError{Op: "accept", Net: l.fd.net, Source: nil, Addr: l.fd.laddr, Err: err}
+	}
+	return c, nil
+}
+
+// Accept implements the Accept method in the [Listener] interface.
+// Returned connections will be of type [*UnixConn].
+func (l *UnixListener) Accept() (Conn, error) {
+	if !l.ok() {
+		return nil, syscall.EINVAL
+	}
+	c, err := l.accept()
+	if err != nil {
+		return nil, &OpError{Op: "accept", Net: l.fd.net, Source: nil, Addr: l.fd.laddr, Err: err}
+	}
+	return c, nil
+}
+
+// Close stops listening on the Unix address. Already accepted
+// connections are not closed.
+func (l *UnixListener) Close() error {
+	if !l.ok() {
+		return syscall.EINVAL
+	}
+	if err := l.close(); err != nil {
+		return &OpError{Op: "close", Net: l.fd.net, Source: nil, Addr: l.fd.laddr, Err: err}
+	}
+	return nil
+}
+
+// Addr returns the listener's network address.
+// The Addr returned is shared by all invocations of Addr, so
+// do not modify it.
+func (l *UnixListener) Addr() Addr { return l.fd.laddr }
+
+// SetDeadline sets the deadline associated with the listener.
+// A zero time value disables the deadline.
+func (l *UnixListener) SetDeadline(t time.Time) error {
+	if !l.ok() {
+		return syscall.EINVAL
+	}
+	return l.fd.SetDeadline(t)
+}
+
+// File returns a copy of the underlying [os.File].
+// It is the caller's responsibility to close f when finished.
+// Closing l does not affect f, and closing f does not affect l.
+//
+// The returned os.File's file descriptor is different from the
+// connection's. Attempting to change properties of the original
+// using this duplicate may or may not have the desired effect.
+func (l *UnixListener) File() (f *os.File, err error) {
+	if !l.ok() {
+		return nil, syscall.EINVAL
+	}
+	f, err = l.file()
+	if err != nil {
+		err = &OpError{Op: "file", Net: l.fd.net, Source: nil, Addr: l.fd.laddr, Err: err}
+	}
+	return
+}
+
+// ListenUnix acts like [Listen] for Unix networks.
+//
+// The network must be "unix" or "unixpacket".
+func ListenUnix(network string, laddr *UnixAddr) (*UnixListener, error) {
+	switch network {
+	case "unix", "unixpacket":
+	default:
+		return nil, &OpError{Op: "listen", Net: network, Source: nil, Addr: laddr.opAddr(), Err: UnknownNetworkError(network)}
+	}
+	if laddr == nil {
+		return nil, &OpError{Op: "listen", Net: network, Source: nil, Addr: laddr.opAddr(), Err: errMissingAddress}
+	}
+	sl := &sysListener{network: network, address: laddr.String()}
+	ln, err := sl.listenUnix(context.Background(), laddr)
+	if err != nil {
+		return nil, &OpError{Op: "listen", Net: network, Source: nil, Addr: laddr.opAddr(), Err: err}
+	}
+	return ln, nil
+}
+
+// ListenUnixgram acts like [ListenPacket] for Unix networks.
+//
+// The network must be "unixgram".
+func ListenUnixgram(network string, laddr *UnixAddr) (*UnixConn, error) {
+	switch network {
+	case "unixgram":
+	default:
+		return nil, &OpError{Op: "listen", Net: network, Source: nil, Addr: laddr.opAddr(), Err: UnknownNetworkError(network)}
+	}
+	if laddr == nil {
+		return nil, &OpError{Op: "listen", Net: network, Source: nil, Addr: nil, Err: errMissingAddress}
+	}
+	sl := &sysListener{network: network, address: laddr.String()}
+	c, err := sl.listenUnixgram(context.Background(), laddr)
+	if err != nil {
+		return nil, &OpError{Op: "listen", Net: network, Source: nil, Addr: laddr.opAddr(), Err: err}
+	}
+	return c, nil
+}