net: fix inconsistent error values on setters

This change fixes inconsistent error values on
Set{Deadline,ReadDeadline,WriteDeadline,ReadBuffer,WriteBuffer} for
Conn, Listener and PacketConn, and
Set{KeepAlive,KeepAlivePeriod,Linger,NoDelay} for TCPConn.

Updates #4856.

Change-Id: I34ca5e98f6de72863f85b2527478b20d8d5394dd
Reviewed-on: https://go-review.googlesource.com/9109
Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/net/dial.go

@@ -180,8 +180,8 @@ func (d *Dialer) Dial(network, address string) (Conn, error) {
 	c, err := dial(network, addrs.first(isIPv4), dialer, d.deadline())
 	if d.KeepAlive > 0 && err == nil {
 		if tc, ok := c.(*TCPConn); ok {
-			tc.SetKeepAlive(true)
+			setKeepAlive(tc.fd, true)
-			tc.SetKeepAlivePeriod(d.KeepAlive)
+			setKeepAlivePeriod(tc.fd, d.KeepAlive)
 			testHookSetKeepAlive()
 		}
 	}

src/net/net.go

@@ -192,7 +192,10 @@ func (c *conn) SetDeadline(t time.Time) error {
 	if !c.ok() {
 		return syscall.EINVAL
 	}
-	return c.fd.setDeadline(t)
+	if err := c.fd.setDeadline(t); err != nil {
+		return &OpError{Op: "set", Net: c.fd.net, Addr: c.fd.laddr, Err: err}
+	}
+	return nil
 }
 
 // SetReadDeadline implements the Conn SetReadDeadline method.
@@ -200,7 +203,10 @@ func (c *conn) SetReadDeadline(t time.Time) error {
 	if !c.ok() {
 		return syscall.EINVAL
 	}
-	return c.fd.setReadDeadline(t)
+	if err := c.fd.setReadDeadline(t); err != nil {
+		return &OpError{Op: "set", Net: c.fd.net, Addr: c.fd.laddr, Err: err}
+	}
+	return nil
 }
 
 // SetWriteDeadline implements the Conn SetWriteDeadline method.
@@ -208,7 +214,10 @@ func (c *conn) SetWriteDeadline(t time.Time) error {
 	if !c.ok() {
 		return syscall.EINVAL
 	}
-	return c.fd.setWriteDeadline(t)
+	if err := c.fd.setWriteDeadline(t); err != nil {
+		return &OpError{Op: "set", Net: c.fd.net, Addr: c.fd.laddr, Err: err}
+	}
+	return nil
 }
 
 // SetReadBuffer sets the size of the operating system's
@@ -217,7 +226,10 @@ func (c *conn) SetReadBuffer(bytes int) error {
 	if !c.ok() {
 		return syscall.EINVAL
 	}
-	return setReadBuffer(c.fd, bytes)
+	if err := setReadBuffer(c.fd, bytes); err != nil {
+		return &OpError{Op: "set", Net: c.fd.net, Addr: c.fd.laddr, Err: err}
+	}
+	return nil
 }
 
 // SetWriteBuffer sets the size of the operating system's
@@ -226,7 +238,10 @@ func (c *conn) SetWriteBuffer(bytes int) error {
 	if !c.ok() {
 		return syscall.EINVAL
 	}
-	return setWriteBuffer(c.fd, bytes)
+	if err := setWriteBuffer(c.fd, bytes); err != nil {
+		return &OpError{Op: "set", Net: c.fd.net, Addr: c.fd.laddr, Err: err}
+	}
+	return nil
 }
 
 // File sets the underlying os.File to blocking mode and returns a copy.

src/net/tcpsock_plan9.go

@@ -69,7 +69,7 @@ func (c *TCPConn) CloseWrite() error {
 // some operating systems after sec seconds have elapsed any remaining
 // unsent data may be discarded.
 func (c *TCPConn) SetLinger(sec int) error {
-	return syscall.EPLAN9
+	return &OpError{Op: "set", Net: c.fd.net, Addr: c.fd.laddr, Err: syscall.EPLAN9}
 }
 
 // SetKeepAlive sets whether the operating system should send
@@ -78,7 +78,10 @@ func (c *TCPConn) SetKeepAlive(keepalive bool) error {
 	if !c.ok() {
 		return syscall.EPLAN9
 	}
-	return setKeepAlive(c.fd, keepalive)
+	if err := setKeepAlive(c.fd, keepalive); err != nil {
+		return &OpError{Op: "set", Net: c.fd.net, Addr: c.fd.laddr, Err: err}
+	}
+	return nil
 }
 
 // SetKeepAlivePeriod sets period between keep alives.
@@ -86,7 +89,10 @@ func (c *TCPConn) SetKeepAlivePeriod(d time.Duration) error {
 	if !c.ok() {
 		return syscall.EPLAN9
 	}
-	return setKeepAlivePeriod(c.fd, d)
+	if err := setKeepAlivePeriod(c.fd, d); err != nil {
+		return &OpError{Op: "set", Net: c.fd.net, Addr: c.fd.laddr, Err: err}
+	}
+	return nil
 }
 
 // SetNoDelay controls whether the operating system should delay
@@ -94,7 +100,7 @@ func (c *TCPConn) SetKeepAlivePeriod(d time.Duration) error {
 // algorithm).  The default is true (no delay), meaning that data is
 // sent as soon as possible after a Write.
 func (c *TCPConn) SetNoDelay(noDelay bool) error {
-	return syscall.EPLAN9
+	return &OpError{Op: "set", Net: c.fd.net, Addr: c.fd.laddr, Err: syscall.EPLAN9}
 }
 
 // DialTCP connects to the remote address raddr on the network net,
@@ -183,7 +189,10 @@ func (l *TCPListener) SetDeadline(t time.Time) error {
 	if l == nil || l.fd == nil || l.fd.ctl == nil {
 		return syscall.EINVAL
 	}
-	return l.fd.setDeadline(t)
+	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

src/net/tcpsock_posix.go

@@ -53,7 +53,7 @@ type TCPConn struct {
 
 func newTCPConn(fd *netFD) *TCPConn {
 	c := &TCPConn{conn{fd}}
-	c.SetNoDelay(true)
+	setNoDelay(c.fd, true)
 	return c
 }
 
@@ -114,7 +114,10 @@ func (c *TCPConn) SetLinger(sec int) error {
 	if !c.ok() {
 		return syscall.EINVAL
 	}
-	return setLinger(c.fd, sec)
+	if err := setLinger(c.fd, sec); err != nil {
+		return &OpError{Op: "set", Net: c.fd.net, Addr: c.fd.laddr, Err: err}
+	}
+	return nil
 }
 
 // SetKeepAlive sets whether the operating system should send
@@ -123,7 +126,10 @@ func (c *TCPConn) SetKeepAlive(keepalive bool) error {
 	if !c.ok() {
 		return syscall.EINVAL
 	}
-	return setKeepAlive(c.fd, keepalive)
+	if err := setKeepAlive(c.fd, keepalive); err != nil {
+		return &OpError{Op: "set", Net: c.fd.net, Addr: c.fd.laddr, Err: err}
+	}
+	return nil
 }
 
 // SetKeepAlivePeriod sets period between keep alives.
@@ -131,7 +137,10 @@ func (c *TCPConn) SetKeepAlivePeriod(d time.Duration) error {
 	if !c.ok() {
 		return syscall.EINVAL
 	}
-	return setKeepAlivePeriod(c.fd, d)
+	if err := setKeepAlivePeriod(c.fd, d); err != nil {
+		return &OpError{Op: "set", Net: c.fd.net, Addr: c.fd.laddr, Err: err}
+	}
+	return nil
 }
 
 // SetNoDelay controls whether the operating system should delay
@@ -142,7 +151,10 @@ func (c *TCPConn) SetNoDelay(noDelay bool) error {
 	if !c.ok() {
 		return syscall.EINVAL
 	}
-	return setNoDelay(c.fd, noDelay)
+	if err := setNoDelay(c.fd, noDelay); err != nil {
+		return &OpError{Op: "set", Net: c.fd.net, Addr: c.fd.laddr, Err: err}
+	}
+	return nil
 }
 
 // DialTCP connects to the remote address raddr on the network net,
@@ -280,7 +292,10 @@ func (l *TCPListener) SetDeadline(t time.Time) error {
 	if l == nil || l.fd == nil {
 		return syscall.EINVAL
 	}
-	return l.fd.setDeadline(t)
+	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

src/net/unixsock_plan9.go

@@ -122,7 +122,7 @@ func (l *UnixListener) Addr() Addr { return nil }
 // SetDeadline sets the deadline associated with the listener.
 // A zero time value disables the deadline.
 func (l *UnixListener) SetDeadline(t time.Time) error {
-	return syscall.EPLAN9
+	return &OpError{Op: "set", Net: "<nil>", Addr: nil, Err: syscall.EPLAN9}
 }
 
 // File returns a copy of the underlying os.File, set to blocking

src/net/unixsock_posix.go

@@ -356,11 +356,14 @@ 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) (err error) {
+func (l *UnixListener) SetDeadline(t time.Time) error {
 	if l == nil || l.fd == nil {
 		return syscall.EINVAL
 	}
-	return l.fd.setDeadline(t)
+	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