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// 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.
// +build darwin dragonfly freebsd linux nacl netbsd openbsd solaris windows
package net
import (
"errors"
"os"
"syscall"
"time"
)
func unixSocket(net string, laddr, raddr sockaddr, mode string, deadline time.Time) (*netFD, error) {
var sotype int
switch net {
case "unix":
sotype = syscall.SOCK_STREAM
case "unixgram":
sotype = syscall.SOCK_DGRAM
case "unixpacket":
sotype = syscall.SOCK_SEQPACKET
default:
return nil, UnknownNetworkError(net)
}
switch mode {
case "dial":
if laddr != nil && laddr.isWildcard() {
laddr = nil
}
if raddr != nil && raddr.isWildcard() {
raddr = nil
}
if raddr == nil && (sotype != syscall.SOCK_DGRAM || laddr == nil) {
return nil, errMissingAddress
}
case "listen":
default:
return nil, errors.New("unknown mode: " + mode)
}
fd, err := socket(net, syscall.AF_UNIX, sotype, 0, false, laddr, raddr, deadline)
if err != nil {
return nil, err
}
return fd, nil
}
func sockaddrToUnix(sa syscall.Sockaddr) Addr {
if s, ok := sa.(*syscall.SockaddrUnix); ok {
return &UnixAddr{Name: s.Name, Net: "unix"}
}
return nil
}
func sockaddrToUnixgram(sa syscall.Sockaddr) Addr {
if s, ok := sa.(*syscall.SockaddrUnix); ok {
return &UnixAddr{Name: s.Name, Net: "unixgram"}
}
return nil
}
func sockaddrToUnixpacket(sa syscall.Sockaddr) Addr {
if s, ok := sa.(*syscall.SockaddrUnix); ok {
return &UnixAddr{Name: s.Name, Net: "unixpacket"}
}
return nil
}
func sotypeToNet(sotype int) string {
switch sotype {
case syscall.SOCK_STREAM:
return "unix"
case syscall.SOCK_DGRAM:
return "unixgram"
case syscall.SOCK_SEQPACKET:
return "unixpacket"
default:
panic("sotypeToNet unknown socket type")
}
}
func (a *UnixAddr) family() int {
return syscall.AF_UNIX
}
func (a *UnixAddr) isWildcard() bool {
return a == nil || a.Name == ""
}
func (a *UnixAddr) sockaddr(family int) (syscall.Sockaddr, error) {
if a == nil {
return nil, nil
}
return &syscall.SockaddrUnix{Name: a.Name}, nil
}
// UnixConn is an implementation of the Conn interface for connections
// to Unix domain sockets.
type UnixConn struct {
conn
}
func newUnixConn(fd *netFD) *UnixConn { return &UnixConn{conn{fd}} }
// ReadFromUnix reads a packet from c, copying the payload into b. It
// returns the number of bytes copied into b and the source address of
// the packet.
//
// ReadFromUnix can be made to time out and return an error with
// Timeout() == true after a fixed time limit; see SetDeadline and
// SetReadDeadline.
func (c *UnixConn) ReadFromUnix(b []byte) (int, *UnixAddr, error) {
if !c.ok() {
return 0, nil, syscall.EINVAL
}
var addr *UnixAddr
n, sa, err := c.fd.readFrom(b)
switch sa := sa.(type) {
case *syscall.SockaddrUnix:
if sa.Name != "" {
addr = &UnixAddr{Name: sa.Name, Net: sotypeToNet(c.fd.sotype)}
}
}
if err != nil {
err = &OpError{Op: "read", Net: c.fd.net, Addr: c.fd.laddr, 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.ReadFromUnix(b)
if addr == nil {
return n, nil, err
}
return n, addr, err
}
// ReadMsgUnix reads a packet 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 packet, and the source address of the packet.
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, sa, err := c.fd.readMsg(b, oob)
switch sa := sa.(type) {
case *syscall.SockaddrUnix:
if sa.Name != "" {
addr = &UnixAddr{Name: sa.Name, Net: sotypeToNet(c.fd.sotype)}
}
}
if err != nil {
err = &OpError{Op: "read", Net: c.fd.net, Addr: c.fd.laddr, Err: err}
}
return
}
// WriteToUnix writes a packet to addr via c, copying the payload from b.
//
// WriteToUnix can be made to time out and return an error with
// Timeout() == true after a fixed time limit; see SetDeadline and
// SetWriteDeadline. On packet-oriented connections, write timeouts
// are rare.
func (c *UnixConn) WriteToUnix(b []byte, addr *UnixAddr) (int, error) {
if !c.ok() {
return 0, syscall.EINVAL
}
if c.fd.isConnected {
return 0, &OpError{Op: "write", Net: c.fd.net, Addr: addr, Err: ErrWriteToConnected}
}
if addr == nil {
return 0, &OpError{Op: "write", Net: c.fd.net, Addr: nil, Err: errMissingAddress}
}
if addr.Net != sotypeToNet(c.fd.sotype) {
return 0, &OpError{Op: "write", Net: c.fd.net, Addr: addr, Err: syscall.EAFNOSUPPORT}
}
sa := &syscall.SockaddrUnix{Name: addr.Name}
n, err := c.fd.writeTo(b, sa)
if err != nil {
err = &OpError{Op: "write", Net: c.fd.net, Addr: addr, Err: err}
}
return n, err
}
// WriteTo implements the PacketConn WriteTo method.
func (c *UnixConn) WriteTo(b []byte, addr Addr) (n int, err error) {
if !c.ok() {
return 0, syscall.EINVAL
}
a, ok := addr.(*UnixAddr)
if !ok {
return 0, &OpError{Op: "write", Net: c.fd.net, Addr: addr, Err: syscall.EINVAL}
}
return c.WriteToUnix(b, a)
}
// WriteMsgUnix writes a packet 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.
func (c *UnixConn) WriteMsgUnix(b, oob []byte, addr *UnixAddr) (n, oobn int, err error) {
if !c.ok() {
return 0, 0, syscall.EINVAL
}
if c.fd.sotype == syscall.SOCK_DGRAM && c.fd.isConnected {
return 0, 0, &OpError{Op: "write", Net: c.fd.net, Addr: addr, Err: ErrWriteToConnected}
}
var sa syscall.Sockaddr
if addr != nil {
if addr.Net != sotypeToNet(c.fd.sotype) {
return 0, 0, &OpError{Op: "write", Net: c.fd.net, Addr: addr, Err: syscall.EAFNOSUPPORT}
}
sa = &syscall.SockaddrUnix{Name: addr.Name}
}
n, oobn, err = c.fd.writeMsg(b, oob, sa)
if err != nil {
err = &OpError{Op: "write", Net: c.fd.net, Addr: addr, Err: err}
}
return
}
// 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
}
err := c.fd.closeRead()
if err != nil {
err = &OpError{Op: "close", Net: c.fd.net, Addr: c.fd.raddr, Err: err}
}
return err
}
// 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
}
err := c.fd.closeWrite()
if err != nil {
err = &OpError{Op: "close", Net: c.fd.net, Addr: c.fd.raddr, Err: err}
}
return err
}
// DialUnix connects to the remote address raddr on the network net,
// which must be "unix", "unixgram" or "unixpacket". If laddr is not
// nil, it is used as the local address for the connection.
func DialUnix(net string, laddr, raddr *UnixAddr) (*UnixConn, error) {
switch net {
case "unix", "unixgram", "unixpacket":
default:
return nil, &OpError{Op: "dial", Net: net, Addr: raddr, Err: UnknownNetworkError(net)}
}
return dialUnix(net, laddr, raddr, noDeadline)
}
func dialUnix(net string, laddr, raddr *UnixAddr, deadline time.Time) (*UnixConn, error) {
fd, err := unixSocket(net, laddr, raddr, "dial", deadline)
if err != nil {
return nil, &OpError{Op: "dial", Net: net, Addr: raddr, Err: err}
}
return newUnixConn(fd), 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
}
// ListenUnix announces on the Unix domain socket laddr and returns a
// Unix listener. The network net must be "unix" or "unixpacket".
func ListenUnix(net string, laddr *UnixAddr) (*UnixListener, error) {
switch net {
case "unix", "unixpacket":
default:
return nil, &OpError{Op: "listen", Net: net, Addr: laddr, Err: UnknownNetworkError(net)}
}
if laddr == nil {
return nil, &OpError{Op: "listen", Net: net, Addr: nil, Err: errMissingAddress}
}
fd, err := unixSocket(net, laddr, nil, "listen", noDeadline)
if err != nil {
return nil, &OpError{Op: "listen", Net: net, Addr: laddr, Err: err}
}
return &UnixListener{fd, fd.laddr.String()}, nil
}
// AcceptUnix accepts the next incoming call and returns the new
// connection.
func (l *UnixListener) AcceptUnix() (*UnixConn, error) {
if l == nil || l.fd == nil {
return nil, syscall.EINVAL
}
fd, err := l.fd.accept()
if err != nil {
return nil, &OpError{Op: "accept", Net: l.fd.net, Addr: l.fd.laddr, Err: err}
}
return newUnixConn(fd), nil
}
// Accept implements the Accept method in the Listener interface; it
// waits for the next call and returns a generic Conn.
func (l *UnixListener) Accept() (c Conn, err error) {
c1, err := l.AcceptUnix()
if err != nil {
return nil, err
}
return c1, nil
}
// Close stops listening on the Unix address. Already accepted
// connections are not closed.
func (l *UnixListener) Close() error {
if l == nil || l.fd == nil {
return syscall.EINVAL
}
// The operating system doesn't clean up
// the file that announcing created, so
// we have to clean it up ourselves.
// There's a race here--we can't know for
// sure whether someone else has come along
// and replaced our socket name already--
// but this sequence (remove then close)
// is at least compatible with the auto-remove
// sequence in ListenUnix. It's only non-Go
// programs that can mess us up.
if l.path[0] != '@' {
syscall.Unlink(l.path)
}
err := l.fd.Close()
if err != nil {
err = &OpError{Op: "close", Net: l.fd.net, Addr: l.fd.laddr, Err: err}
}
return err
}
// 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 == nil || l.fd == nil {
return syscall.EINVAL
}
if err := l.fd.setDeadline(t); err != nil {
return &OpError{Op: "set", Net: l.fd.net, Addr: l.fd.laddr, Err: err}
}
return nil
}
// File returns a copy of the underlying os.File, set to blocking
// mode. 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) {
f, err = l.fd.dup()
if err != nil {
err = &OpError{Op: "file", Net: l.fd.net, Addr: l.fd.laddr, Err: err}
}
return
}
// ListenUnixgram listens for incoming Unix datagram packets addressed
// to the local address laddr. The network net must be "unixgram".
// The returned connection's ReadFrom and WriteTo methods can be used
// to receive and send packets with per-packet addressing.
func ListenUnixgram(net string, laddr *UnixAddr) (*UnixConn, error) {
switch net {
case "unixgram":
default:
return nil, &OpError{Op: "listen", Net: net, Addr: laddr, Err: UnknownNetworkError(net)}
}
if laddr == nil {
return nil, &OpError{Op: "listen", Net: net, Addr: nil, Err: errMissingAddress}
}
fd, err := unixSocket(net, laddr, nil, "listen", noDeadline)
if err != nil {
return nil, &OpError{Op: "listen", Net: net, Addr: laddr, Err: err}
}
return newUnixConn(fd), nil
}