diff options
Diffstat (limited to 'vendor/gopkg.in/natefinch/npipe.v2/npipe_windows.go')
-rwxr-xr-x | vendor/gopkg.in/natefinch/npipe.v2/npipe_windows.go | 531 |
1 files changed, 531 insertions, 0 deletions
diff --git a/vendor/gopkg.in/natefinch/npipe.v2/npipe_windows.go b/vendor/gopkg.in/natefinch/npipe.v2/npipe_windows.go new file mode 100755 index 000000000..5e7cf13ee --- /dev/null +++ b/vendor/gopkg.in/natefinch/npipe.v2/npipe_windows.go @@ -0,0 +1,531 @@ +package npipe + +//sys createNamedPipe(name *uint16, openMode uint32, pipeMode uint32, maxInstances uint32, outBufSize uint32, inBufSize uint32, defaultTimeout uint32, sa *syscall.SecurityAttributes) (handle syscall.Handle, err error) [failretval==syscall.InvalidHandle] = CreateNamedPipeW +//sys connectNamedPipe(handle syscall.Handle, overlapped *syscall.Overlapped) (err error) = ConnectNamedPipe +//sys disconnectNamedPipe(handle syscall.Handle) (err error) = DisconnectNamedPipe +//sys waitNamedPipe(name *uint16, timeout uint32) (err error) = WaitNamedPipeW +//sys createEvent(sa *syscall.SecurityAttributes, manualReset bool, initialState bool, name *uint16) (handle syscall.Handle, err error) [failretval==syscall.InvalidHandle] = CreateEventW +//sys getOverlappedResult(handle syscall.Handle, overlapped *syscall.Overlapped, transferred *uint32, wait bool) (err error) = GetOverlappedResult +//sys cancelIoEx(handle syscall.Handle, overlapped *syscall.Overlapped) (err error) = CancelIoEx + +import ( + "fmt" + "io" + "net" + "sync" + "syscall" + "time" +) + +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 { + 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 + } + + 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 { + mu sync.Mutex + + 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 +} + +// 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 { + return nil, syscall.EINVAL + } + + l.mu.Lock() + defer l.mu.Unlock() + + if 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) + err = connectNamedPipe(handle, overlapped) + if err == nil || err == error_pipe_connected { + return &PipeConn{handle: handle, addr: l.addr}, nil + } + + if err == error_io_incomplete || err == syscall.ERROR_IO_PENDING { + l.acceptOverlapped = overlapped + l.acceptHandle = handle + // unlock here so close can function correctly while we wait (we'll + // get relocked via the defer below, before the original defer + // unlock happens.) + l.mu.Unlock() + defer func() { + l.mu.Lock() + l.acceptOverlapped = nil + l.acceptHandle = 0 + // unlock is via defer above. + }() + _, 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 { + l.mu.Lock() + defer l.mu.Unlock() + + 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 + } + 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} +} |