// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
// +build windows
package rpc
import (
"fmt"
"io"
"net"
"sync"
"syscall"
"time"
"unsafe"
)
var (
modkernel32 = syscall.NewLazyDLL("kernel32.dll")
procCreateNamedPipeW = modkernel32.NewProc("CreateNamedPipeW")
procConnectNamedPipe = modkernel32.NewProc("ConnectNamedPipe")
procDisconnectNamedPipe = modkernel32.NewProc("DisconnectNamedPipe")
procWaitNamedPipeW = modkernel32.NewProc("WaitNamedPipeW")
procCreateEventW = modkernel32.NewProc("CreateEventW")
procGetOverlappedResult = modkernel32.NewProc("GetOverlappedResult")
procCancelIoEx = modkernel32.NewProc("CancelIoEx")
)
func createNamedPipe(name *uint16, openMode uint32, pipeMode uint32, maxInstances uint32, outBufSize uint32, inBufSize uint32, defaultTimeout uint32, sa *syscall.SecurityAttributes) (handle syscall.Handle, err error) {
r0, _, e1 := syscall.Syscall9(procCreateNamedPipeW.Addr(), 8, uintptr(unsafe.Pointer(name)), uintptr(openMode), uintptr(pipeMode), uintptr(maxInstances), uintptr(outBufSize), uintptr(inBufSize), uintptr(defaultTimeout), uintptr(unsafe.Pointer(sa)), 0)
handle = syscall.Handle(r0)
if handle == syscall.InvalidHandle {
if e1 != 0 {
err = error(e1)
} else {
err = syscall.EINVAL
}
}
return
}
func cancelIoEx(handle syscall.Handle, overlapped *syscall.Overlapped) (err error) {
r1, _, e1 := syscall.Syscall(procCancelIoEx.Addr(), 2, uintptr(handle), uintptr(unsafe.Pointer(overlapped)), 0)
if r1 == 0 {
if e1 != 0 {
err = error(e1)
} else {
err = syscall.EINVAL
}
}
return
}
func connectNamedPipe(handle syscall.Handle, overlapped *syscall.Overlapped) (err error) {
r1, _, e1 := syscall.Syscall(procConnectNamedPipe.Addr(), 2, uintptr(handle), uintptr(unsafe.Pointer(overlapped)), 0)
if r1 == 0 {
if e1 != 0 {
err = error(e1)
} else {
err = syscall.EINVAL
}
}
return
}
func disconnectNamedPipe(handle syscall.Handle) (err error) {
r1, _, e1 := syscall.Syscall(procDisconnectNamedPipe.Addr(), 1, uintptr(handle), 0, 0)
if r1 == 0 {
if e1 != 0 {
err = error(e1)
} else {
err = syscall.EINVAL
}
}
return
}
func waitNamedPipe(name *uint16, timeout uint32) (err error) {
r1, _, e1 := syscall.Syscall(procWaitNamedPipeW.Addr(), 2, uintptr(unsafe.Pointer(name)), uintptr(timeout), 0)
if r1 == 0 {
if e1 != 0 {
err = error(e1)
} else {
err = syscall.EINVAL
}
}
return
}
func createEvent(sa *syscall.SecurityAttributes, manualReset bool, initialState bool, name *uint16) (handle syscall.Handle, err error) {
var _p0 uint32
if manualReset {
_p0 = 1
} else {
_p0 = 0
}
var _p1 uint32
if initialState {
_p1 = 1
} else {
_p1 = 0
}
r0, _, e1 := syscall.Syscall6(procCreateEventW.Addr(), 4, uintptr(unsafe.Pointer(sa)), uintptr(_p0), uintptr(_p1), uintptr(unsafe.Pointer(name)), 0, 0)
handle = syscall.Handle(r0)
if handle == syscall.InvalidHandle {
if e1 != 0 {
err = error(e1)
} else {
err = syscall.EINVAL
}
}
return
}
func getOverlappedResult(handle syscall.Handle, overlapped *syscall.Overlapped, transferred *uint32, wait bool) (err error) {
var _p0 uint32
if wait {
_p0 = 1
} else {
_p0 = 0
}
r1, _, e1 := syscall.Syscall6(procGetOverlappedResult.Addr(), 4, uintptr(handle), uintptr(unsafe.Pointer(overlapped)), uintptr(unsafe.Pointer(transferred)), uintptr(_p0), 0, 0)
if r1 == 0 {
if e1 != 0 {
err = error(e1)
} else {
err = syscall.EINVAL
}
}
return
}
const (
// openMode
pipe_access_duplex = 0x3
pipe_access_inbound = 0x1
pipe_access_outbound = 0x2
// openMode write flags
file_flag_first_pipe_instance = 0x00080000
file_flag_write_through = 0x80000000
file_flag_overlapped = 0x40000000
// openMode ACL flags
write_dac = 0x00040000
write_owner = 0x00080000
access_system_security = 0x01000000
// pipeMode
pipe_type_byte = 0x0
pipe_type_message = 0x4
// pipeMode read mode flags
pipe_readmode_byte = 0x0
pipe_readmode_message = 0x2
// pipeMode wait mode flags
pipe_wait = 0x0
pipe_nowait = 0x1
// pipeMode remote-client mode flags
pipe_accept_remote_clients = 0x0
pipe_reject_remote_clients = 0x8
pipe_unlimited_instances = 255
nmpwait_wait_forever = 0xFFFFFFFF
// the two not-an-errors below occur if a client connects to the pipe between
// the server's CreateNamedPipe and ConnectNamedPipe calls.
error_no_data syscall.Errno = 0xE8
error_pipe_connected syscall.Errno = 0x217
error_pipe_busy syscall.Errno = 0xE7
error_sem_timeout syscall.Errno = 0x79
error_bad_pathname syscall.Errno = 0xA1
error_invalid_name syscall.Errno = 0x7B
error_io_incomplete syscall.Errno = 0x3e4
)
var _ net.Conn = (*PipeConn)(nil)
var _ net.Listener = (*PipeListener)(nil)
// ErrClosed is the error returned by PipeListener.Accept when Close is called
// on the PipeListener.
var ErrClosed = PipeError{"Pipe has been closed.", false}
// PipeError is an error related to a call to a pipe
type PipeError struct {
msg string
timeout bool
}
// Error implements the error interface
func (e PipeError) Error() string {
return e.msg
}
// Timeout implements net.AddrError.Timeout()
func (e PipeError) Timeout() bool {
return e.timeout
}
// Temporary implements net.AddrError.Temporary()
func (e PipeError) Temporary() bool {
return false
}
// Dial connects to a named pipe with the given address. If the specified pipe is not available,
// it will wait indefinitely for the pipe to become available.
//
// The address must be of the form \\.\\pipe\<name> for local pipes and \\<computer>\pipe\<name>
// for remote pipes.
//
// Dial will return a PipeError if you pass in a badly formatted pipe name.
//
// Examples:
// // local pipe
// conn, err := Dial(`\\.\pipe\mypipename`)
//
// // remote pipe
// conn, err := Dial(`\\othercomp\pipe\mypipename`)
func Dial(address string) (*PipeConn, error) {
for {
conn, err := dial(address, nmpwait_wait_forever)
if err == nil {
// Ugly hack working around some async connectivity issues
time.Sleep(100 * time.Millisecond)
return conn, nil
}
if isPipeNotReady(err) {
<-time.After(100 * time.Millisecond)
continue
}
return nil, err
}
}
// DialTimeout acts like Dial, but will time out after the duration of timeout
func DialTimeout(address string, timeout time.Duration) (*PipeConn, error) {
deadline := time.Now().Add(timeout)
now := time.Now()
for now.Before(deadline) {
millis := uint32(deadline.Sub(now) / time.Millisecond)
conn, err := dial(address, millis)
if err == nil {
return conn, nil
}
if err == error_sem_timeout {
// This is WaitNamedPipe's timeout error, so we know we're done
return nil, PipeError{fmt.Sprintf(
"Timed out waiting for pipe '%s' to come available", address), true}
}
if isPipeNotReady(err) {
left := deadline.Sub(time.Now())
retry := 100 * time.Millisecond
if left > retry {
<-time.After(retry)
} else {
<-time.After(left - time.Millisecond)
}
now = time.Now()
continue
}
return nil, err
}
return nil, PipeError{fmt.Sprintf(
"Timed out waiting for pipe '%s' to come available", address), true}
}
// isPipeNotReady checks the error to see if it indicates the pipe is not ready
func isPipeNotReady(err error) bool {
// Pipe Busy means another client just grabbed the open pipe end,
// and the server hasn't made a new one yet.
// File Not Found means the server hasn't created the pipe yet.
// Neither is a fatal error.
return err == syscall.ERROR_FILE_NOT_FOUND || err == error_pipe_busy
}
// newOverlapped creates a structure used to track asynchronous
// I/O requests that have been issued.
func newOverlapped() (*syscall.Overlapped, error) {
event, err := createEvent(nil, true, true, nil)
if err != nil {
return nil, err
}
return &syscall.Overlapped{HEvent: event}, nil
}
// waitForCompletion waits for an asynchronous I/O request referred to by overlapped to complete.
// This function returns the number of bytes transferred by the operation and an error code if
// applicable (nil otherwise).
func waitForCompletion(handle syscall.Handle, overlapped *syscall.Overlapped) (uint32, error) {
_, err := syscall.WaitForSingleObject(overlapped.HEvent, syscall.INFINITE)
if err != nil {
return 0, err
}
var transferred uint32
err = getOverlappedResult(handle, overlapped, &transferred, true)
return transferred, err
}
// dial is a helper to initiate a connection to a named pipe that has been started by a server.
// The timeout is only enforced if the pipe server has already created the pipe, otherwise
// this function will return immediately.
func dial(address string, timeout uint32) (*PipeConn, error) {
name, err := syscall.UTF16PtrFromString(string(address))
if err != nil {
return nil, err
}
// If at least one instance of the pipe has been created, this function
// will wait timeout milliseconds for it to become available.
// It will return immediately regardless of timeout, if no instances
// of the named pipe have been created yet.
// If this returns with no error, there is a pipe available.
if err := waitNamedPipe(name, timeout); err != nil {
if err == error_bad_pathname {
// badly formatted pipe name
return nil, badAddr(address)
}
return nil, err
}
pathp, err := syscall.UTF16PtrFromString(address)
if err != nil {
return nil, err
}
handle, err := syscall.CreateFile(pathp, syscall.GENERIC_READ|syscall.GENERIC_WRITE,
uint32(syscall.FILE_SHARE_READ|syscall.FILE_SHARE_WRITE), nil, syscall.OPEN_EXISTING,
syscall.FILE_FLAG_OVERLAPPED, 0)
if err != nil {
return nil, err
}
return &PipeConn{handle: handle, addr: PipeAddr(address)}, nil
}
// Listen returns a new PipeListener that will listen on a pipe with the given
// address. The address must be of the form \\.\pipe\<name>
//
// Listen will return a PipeError for an incorrectly formatted pipe name.
func Listen(address string) (*PipeListener, error) {
handle, err := createPipe(address, true)
if err == error_invalid_name {
return nil, badAddr(address)
}
if err != nil {
return nil, err
}
// Ugly hack working around some async connectivity issues
time.Sleep(100 * time.Millisecond)
return &PipeListener{
addr: PipeAddr(address),
handle: handle,
}, nil
}
// PipeListener is a named pipe listener. Clients should typically
// use variables of type net.Listener instead of assuming named pipe.
type PipeListener struct {
addr PipeAddr
handle syscall.Handle
closed bool
// acceptHandle contains the current handle waiting for
// an incoming connection or nil.
acceptHandle syscall.Handle
// acceptOverlapped is set before waiting on a connection.
// If not waiting, it is nil.
acceptOverlapped *syscall.Overlapped
// acceptMutex protects the handle and overlapped structure.
acceptMutex sync.Mutex
}
// Accept implements the Accept method in the net.Listener interface; it
// waits for the next call and returns a generic net.Conn.
func (l *PipeListener) Accept() (net.Conn, error) {
c, err := l.AcceptPipe()
for err == error_no_data {
// Ignore clients that connect and immediately disconnect.
c, err = l.AcceptPipe()
}
if err != nil {
return nil, err
}
return c, nil
}
// AcceptPipe accepts the next incoming call and returns the new connection.
// It might return an error if a client connected and immediately cancelled
// the connection.
func (l *PipeListener) AcceptPipe() (*PipeConn, error) {
if l == nil || l.addr == "" || l.closed {
return nil, syscall.EINVAL
}
// the first time we call accept, the handle will have been created by the Listen
// call. This is to prevent race conditions where the client thinks the server
// isn't listening because it hasn't actually called create yet. After the first time, we'll
// have to create a new handle each time
handle := l.handle
if handle == 0 {
var err error
handle, err = createPipe(string(l.addr), false)
if err != nil {
return nil, err
}
} else {
l.handle = 0
}
overlapped, err := newOverlapped()
if err != nil {
return nil, err
}
defer syscall.CloseHandle(overlapped.HEvent)
if err := connectNamedPipe(handle, overlapped); err != nil && err != error_pipe_connected {
if err == error_io_incomplete || err == syscall.ERROR_IO_PENDING {
l.acceptMutex.Lock()
l.acceptOverlapped = overlapped
l.acceptHandle = handle
l.acceptMutex.Unlock()
defer func() {
l.acceptMutex.Lock()
l.acceptOverlapped = nil
l.acceptHandle = 0
l.acceptMutex.Unlock()
}()
_, err = waitForCompletion(handle, overlapped)
}
if err == syscall.ERROR_OPERATION_ABORTED {
// Return error compatible to net.Listener.Accept() in case the
// listener was closed.
return nil, ErrClosed
}
if err != nil {
return nil, err
}
}
return &PipeConn{handle: handle, addr: l.addr}, nil
}
// Close stops listening on the address.
// Already Accepted connections are not closed.
func (l *PipeListener) Close() error {
if l.closed {
return nil
}
l.closed = true
if l.handle != 0 {
err := disconnectNamedPipe(l.handle)
if err != nil {
return err
}
err = syscall.CloseHandle(l.handle)
if err != nil {
return err
}
l.handle = 0
}
l.acceptMutex.Lock()
defer l.acceptMutex.Unlock()
if l.acceptOverlapped != nil && l.acceptHandle != 0 {
// Cancel the pending IO. This call does not block, so it is safe
// to hold onto the mutex above.
if err := cancelIoEx(l.acceptHandle, l.acceptOverlapped); err != nil {
return err
}
err := syscall.CloseHandle(l.acceptOverlapped.HEvent)
if err != nil {
return err
}
l.acceptOverlapped.HEvent = 0
err = syscall.CloseHandle(l.acceptHandle)
if err != nil {
return err
}
l.acceptHandle = 0
}
return nil
}
// Addr returns the listener's network address, a PipeAddr.
func (l *PipeListener) Addr() net.Addr { return l.addr }
// PipeConn is the implementation of the net.Conn interface for named pipe connections.
type PipeConn struct {
handle syscall.Handle
addr PipeAddr
// these aren't actually used yet
readDeadline *time.Time
writeDeadline *time.Time
}
type iodata struct {
n uint32
err error
}
// completeRequest looks at iodata to see if a request is pending. If so, it waits for it to either complete or to
// abort due to hitting the specified deadline. Deadline may be set to nil to wait forever. If no request is pending,
// the content of iodata is returned.
func (c *PipeConn) completeRequest(data iodata, deadline *time.Time, overlapped *syscall.Overlapped) (int, error) {
if data.err == error_io_incomplete || data.err == syscall.ERROR_IO_PENDING {
var timer <-chan time.Time
if deadline != nil {
if timeDiff := deadline.Sub(time.Now()); timeDiff > 0 {
timer = time.After(timeDiff)
}
}
done := make(chan iodata)
go func() {
n, err := waitForCompletion(c.handle, overlapped)
done <- iodata{n, err}
}()
select {
case data = <-done:
case <-timer:
syscall.CancelIoEx(c.handle, overlapped)
data = iodata{0, timeout(c.addr.String())}
}
}
// Windows will produce ERROR_BROKEN_PIPE upon closing
// a handle on the other end of a connection. Go RPC
// expects an io.EOF error in this case.
if data.err == syscall.ERROR_BROKEN_PIPE {
data.err = io.EOF
}
return int(data.n), data.err
}
// Read implements the net.Conn Read method.
func (c *PipeConn) Read(b []byte) (int, error) {
// Use ReadFile() rather than Read() because the latter
// contains a workaround that eats ERROR_BROKEN_PIPE.
overlapped, err := newOverlapped()
if err != nil {
return 0, err
}
defer syscall.CloseHandle(overlapped.HEvent)
var n uint32
err = syscall.ReadFile(c.handle, b, &n, overlapped)
return c.completeRequest(iodata{n, err}, c.readDeadline, overlapped)
}
// Write implements the net.Conn Write method.
func (c *PipeConn) Write(b []byte) (int, error) {
overlapped, err := newOverlapped()
if err != nil {
return 0, err
}
defer syscall.CloseHandle(overlapped.HEvent)
var n uint32
err = syscall.WriteFile(c.handle, b, &n, overlapped)
return c.completeRequest(iodata{n, err}, c.writeDeadline, overlapped)
}
// Close closes the connection.
func (c *PipeConn) Close() error {
return syscall.CloseHandle(c.handle)
}
// LocalAddr returns the local network address.
func (c *PipeConn) LocalAddr() net.Addr {
return c.addr
}
// RemoteAddr returns the remote network address.
func (c *PipeConn) RemoteAddr() net.Addr {
// not sure what to do here, we don't have remote addr....
return c.addr
}
// SetDeadline implements the net.Conn SetDeadline method.
// Note that timeouts are only supported on Windows Vista/Server 2008 and above
func (c *PipeConn) SetDeadline(t time.Time) error {
c.SetReadDeadline(t)
c.SetWriteDeadline(t)
return nil
}
// SetReadDeadline implements the net.Conn SetReadDeadline method.
// Note that timeouts are only supported on Windows Vista/Server 2008 and above
func (c *PipeConn) SetReadDeadline(t time.Time) error {
c.readDeadline = &t
return nil
}
// SetWriteDeadline implements the net.Conn SetWriteDeadline method.
// Note that timeouts are only supported on Windows Vista/Server 2008 and above
func (c *PipeConn) SetWriteDeadline(t time.Time) error {
c.writeDeadline = &t
return nil
}
// PipeAddr represents the address of a named pipe.
type PipeAddr string
// Network returns the address's network name, "pipe".
func (a PipeAddr) Network() string { return "pipe" }
// String returns the address of the pipe
func (a PipeAddr) String() string {
return string(a)
}
// createPipe is a helper function to make sure we always create pipes
// with the same arguments, since subsequent calls to create pipe need
// to use the same arguments as the first one. If first is set, fail
// if the pipe already exists.
func createPipe(address string, first bool) (syscall.Handle, error) {
n, err := syscall.UTF16PtrFromString(address)
if err != nil {
return 0, err
}
mode := uint32(pipe_access_duplex | syscall.FILE_FLAG_OVERLAPPED)
if first {
mode |= file_flag_first_pipe_instance
}
return createNamedPipe(n,
mode,
pipe_type_byte,
pipe_unlimited_instances,
512, 512, 0, nil)
}
func badAddr(addr string) PipeError {
return PipeError{fmt.Sprintf("Invalid pipe address '%s'.", addr), false}
}
func timeout(addr string) PipeError {
return PipeError{fmt.Sprintf("Pipe IO timed out waiting for '%s'", addr), true}
}
// ipcListen will create a named pipe on the given endpoint.
func ipcListen(endpoint string) (net.Listener, error) {
return Listen(endpoint)
}
// newIPCConnection will connect to a named pipe with the given endpoint as name.
func newIPCConnection(endpoint string) (net.Conn, error) {
return Dial(endpoint)
}
