Merge pull request #1261 from dcantah/backport-exec-and-cpty

[release/0.9] Backport TTY support for Host Process Containers

.golangci.yml

@@ -1,3 +1,6 @@
+run:
+  timeout: 8m
+
 linters:
   enable:
     - stylecheck

go.mod

@@ -29,7 +29,7 @@ require (
 	go.opencensus.io v0.22.3
 	golang.org/x/net v0.0.0-20210825183410-e898025ed96a // indirect
 	golang.org/x/sync v0.0.0-20210220032951-036812b2e83c
-	golang.org/x/sys v0.0.0-20210510120138-977fb7262007
+	golang.org/x/sys v0.0.0-20211216021012-1d35b9e2eb4e
 	google.golang.org/grpc v1.40.0
 )
 

go.sum

@@ -812,8 +812,9 @@ golang.org/x/sys v0.0.0-20210324051608-47abb6519492/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20210330210617-4fbd30eecc44/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210426230700-d19ff857e887/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20210510120138-977fb7262007 h1:gG67DSER+11cZvqIMb8S8bt0vZtiN6xWYARwirrOSfE=
 golang.org/x/sys v0.0.0-20210510120138-977fb7262007/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20211216021012-1d35b9e2eb4e h1:fLOSk5Q00efkSvAm+4xcoXD+RRmLmmulPn5I3Y9F2EM=
+golang.org/x/sys v0.0.0-20211216021012-1d35b9e2eb4e/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=

internal/conpty/conpty.go

@@ -0,0 +1,149 @@
+package conpty
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"sync"
+	"unsafe"
+
+	"github.com/Microsoft/hcsshim/internal/winapi"
+	"golang.org/x/sys/windows"
+)
+
+var (
+	errClosedConPty   = errors.New("pseudo console is closed")
+	errNotInitialized = errors.New("pseudo console hasn't been initialized")
+)
+
+// Pty is a wrapper around a Windows PseudoConsole handle. Create a new instance by calling `Create()`.
+type Pty struct {
+	// handleLock guards hpc
+	handleLock sync.RWMutex
+	// hpc is the pseudo console handle
+	hpc windows.Handle
+	// inPipe and outPipe are our end of the pipes to read/write to the pseudo console.
+	inPipe  *os.File
+	outPipe *os.File
+}
+
+// Create returns a new `Pty` object. This object is not ready for IO until `UpdateProcThreadAttribute` is called and a process has been started.
+func Create(width, height int16, flags uint32) (*Pty, error) {
+	// First we need to make both ends of the conpty's pipes, two to get passed into a process to use as input/output, and two for us to keep to
+	// make use of this data.
+	ptyIn, inPipeOurs, err := os.Pipe()
+	if err != nil {
+		return nil, fmt.Errorf("failed to create pipes for pseudo console: %w", err)
+	}
+
+	outPipeOurs, ptyOut, err := os.Pipe()
+	if err != nil {
+		return nil, fmt.Errorf("failed to create pipes for pseudo console: %w", err)
+	}
+
+	var hpc windows.Handle
+	coord := windows.Coord{X: width, Y: height}
+	err = winapi.CreatePseudoConsole(coord, windows.Handle(ptyIn.Fd()), windows.Handle(ptyOut.Fd()), 0, &hpc)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create pseudo console: %w", err)
+	}
+
+	// The pty's end of its pipes can be closed here without worry. They're duped into the conhost
+	// that will be launched and will be released on a call to ClosePseudoConsole() (Close() on the Pty object).
+	if err := ptyOut.Close(); err != nil {
+		return nil, fmt.Errorf("failed to close pseudo console handle: %w", err)
+	}
+	if err := ptyIn.Close(); err != nil {
+		return nil, fmt.Errorf("failed to close pseudo console handle: %w", err)
+	}
+
+	return &Pty{
+		hpc:     hpc,
+		inPipe:  inPipeOurs,
+		outPipe: outPipeOurs,
+	}, nil
+}
+
+// UpdateProcThreadAttribute updates the passed in attribute list to contain the entry necessary for use with
+// CreateProcess.
+func (c *Pty) UpdateProcThreadAttribute(attrList *windows.ProcThreadAttributeListContainer) error {
+	c.handleLock.RLock()
+	defer c.handleLock.RUnlock()
+
+	if c.hpc == 0 {
+		return errClosedConPty
+	}
+
+	if err := attrList.Update(
+		winapi.PROC_THREAD_ATTRIBUTE_PSEUDOCONSOLE,
+		unsafe.Pointer(c.hpc),
+		unsafe.Sizeof(c.hpc),
+	); err != nil {
+		return fmt.Errorf("failed to update proc thread attributes for pseudo console: %w", err)
+	}
+
+	return nil
+}
+
+// Resize resizes the internal buffers of the pseudo console to the passed in size
+func (c *Pty) Resize(width, height int16) error {
+	c.handleLock.RLock()
+	defer c.handleLock.RUnlock()
+
+	if c.hpc == 0 {
+		return errClosedConPty
+	}
+
+	coord := windows.Coord{X: width, Y: height}
+	if err := winapi.ResizePseudoConsole(c.hpc, coord); err != nil {
+		return fmt.Errorf("failed to resize pseudo console: %w", err)
+	}
+	return nil
+}
+
+// Close closes the pseudo-terminal and cleans up all attached resources
+func (c *Pty) Close() error {
+	c.handleLock.Lock()
+	defer c.handleLock.Unlock()
+
+	if c.hpc == 0 {
+		return errClosedConPty
+	}
+
+	// Close the pseudo console, set the handle to 0 to invalidate this object and then close the side of the pipes that we own.
+	winapi.ClosePseudoConsole(c.hpc)
+	c.hpc = 0
+	if err := c.inPipe.Close(); err != nil {
+		return fmt.Errorf("failed to close pseudo console input pipe: %w", err)
+	}
+	if err := c.outPipe.Close(); err != nil {
+		return fmt.Errorf("failed to close pseudo console output pipe: %w", err)
+	}
+	return nil
+}
+
+// OutPipe returns the output pipe of the pseudo console.
+func (c *Pty) OutPipe() *os.File {
+	return c.outPipe
+}
+
+// InPipe returns the input pipe of the pseudo console.
+func (c *Pty) InPipe() *os.File {
+	return c.inPipe
+}
+
+// Write writes the contents of `buf` to the pseudo console. Returns the number of bytes written and an error if there is one.
+func (c *Pty) Write(buf []byte) (int, error) {
+	if c.inPipe == nil {
+		return 0, errNotInitialized
+	}
+	return c.inPipe.Write(buf)
+}
+
+// Read reads from the pseudo console into `buf`. Returns the number of bytes read and an error if there is one.
+func (c *Pty) Read(buf []byte) (int, error) {
+	if c.outPipe == nil {
+		return 0, errNotInitialized
+	}
+	return c.outPipe.Read(buf)
+}