//go:build windows
// +build windows
package winio
import (
"context"
"errors"
"fmt"
"io"
"net"
"os"
"time"
"unsafe"
"golang.org/x/sys/windows"
"github.com/Microsoft/go-winio/internal/socket"
"github.com/Microsoft/go-winio/pkg/guid"
)
const afHVSock = 34 // AF_HYPERV
// Well known Service and VM IDs
// https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/user-guide/make-integration-service#vmid-wildcards
// HvsockGUIDWildcard is the wildcard VmId for accepting connections from all partitions.
func HvsockGUIDWildcard() guid.GUID { // 00000000-0000-0000-0000-000000000000
return guid.GUID{}
}
// HvsockGUIDBroadcast is the wildcard VmId for broadcasting sends to all partitions.
func HvsockGUIDBroadcast() guid.GUID { // ffffffff-ffff-ffff-ffff-ffffffffffff
return guid.GUID{
Data1: 0xffffffff,
Data2: 0xffff,
Data3: 0xffff,
Data4: [8]uint8{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff},
}
}
// HvsockGUIDLoopback is the Loopback VmId for accepting connections to the same partition as the connector.
func HvsockGUIDLoopback() guid.GUID { // e0e16197-dd56-4a10-9195-5ee7a155a838
return guid.GUID{
Data1: 0xe0e16197,
Data2: 0xdd56,
Data3: 0x4a10,
Data4: [8]uint8{0x91, 0x95, 0x5e, 0xe7, 0xa1, 0x55, 0xa8, 0x38},
}
}
// HvsockGUIDSiloHost is the address of a silo's host partition:
// - The silo host of a hosted silo is the utility VM.
// - The silo host of a silo on a physical host is the physical host.
func HvsockGUIDSiloHost() guid.GUID { // 36bd0c5c-7276-4223-88ba-7d03b654c568
return guid.GUID{
Data1: 0x36bd0c5c,
Data2: 0x7276,
Data3: 0x4223,
Data4: [8]byte{0x88, 0xba, 0x7d, 0x03, 0xb6, 0x54, 0xc5, 0x68},
}
}
// HvsockGUIDChildren is the wildcard VmId for accepting connections from the connector's child partitions.
func HvsockGUIDChildren() guid.GUID { // 90db8b89-0d35-4f79-8ce9-49ea0ac8b7cd
return guid.GUID{
Data1: 0x90db8b89,
Data2: 0xd35,
Data3: 0x4f79,
Data4: [8]uint8{0x8c, 0xe9, 0x49, 0xea, 0xa, 0xc8, 0xb7, 0xcd},
}
}
// HvsockGUIDParent is the wildcard VmId for accepting connections from the connector's parent partition.
// Listening on this VmId accepts connection from:
// - Inside silos: silo host partition.
// - Inside hosted silo: host of the VM.
// - Inside VM: VM host.
// - Physical host: Not supported.
func HvsockGUIDParent() guid.GUID { // a42e7cda-d03f-480c-9cc2-a4de20abb878
return guid.GUID{
Data1: 0xa42e7cda,
Data2: 0xd03f,
Data3: 0x480c,
Data4: [8]uint8{0x9c, 0xc2, 0xa4, 0xde, 0x20, 0xab, 0xb8, 0x78},
}
}
// hvsockVsockServiceTemplate is the Service GUID used for the VSOCK protocol.
func hvsockVsockServiceTemplate() guid.GUID { // 00000000-facb-11e6-bd58-64006a7986d3
return guid.GUID{
Data2: 0xfacb,
Data3: 0x11e6,
Data4: [8]uint8{0xbd, 0x58, 0x64, 0x00, 0x6a, 0x79, 0x86, 0xd3},
}
}
// An HvsockAddr is an address for a AF_HYPERV socket.
type HvsockAddr struct {
VMID guid.GUID
ServiceID guid.GUID
}
type rawHvsockAddr struct {
Family uint16
_ uint16
VMID guid.GUID
ServiceID guid.GUID
}
var _ socket.RawSockaddr = &rawHvsockAddr{}
// Network returns the address's network name, "hvsock".
func (*HvsockAddr) Network() string {
return "hvsock"
}
func (addr *HvsockAddr) String() string {
return fmt.Sprintf("%s:%s", &addr.VMID, &addr.ServiceID)
}
// VsockServiceID returns an hvsock service ID corresponding to the specified AF_VSOCK port.
func VsockServiceID(port uint32) guid.GUID {
g := hvsockVsockServiceTemplate() // make a copy
g.Data1 = port
return g
}
func (addr *HvsockAddr) raw() rawHvsockAddr {
return rawHvsockAddr{
Family: afHVSock,
VMID: addr.VMID,
ServiceID: addr.ServiceID,
}
}
func (addr *HvsockAddr) fromRaw(raw *rawHvsockAddr) {
addr.VMID = raw.VMID
addr.ServiceID = raw.ServiceID
}
// Sockaddr returns a pointer to and the size of this struct.
//
// Implements the [socket.RawSockaddr] interface, and allows use in
// [socket.Bind] and [socket.ConnectEx].
func (r *rawHvsockAddr) Sockaddr() (unsafe.Pointer, int32, error) {
return unsafe.Pointer(r), int32(unsafe.Sizeof(rawHvsockAddr{})), nil
}
// Sockaddr interface allows use with `sockets.Bind()` and `.ConnectEx()`.
func (r *rawHvsockAddr) FromBytes(b []byte) error {
n := int(unsafe.Sizeof(rawHvsockAddr{}))
if len(b) < n {
return fmt.Errorf("got %d, want %d: %w", len(b), n, socket.ErrBufferSize)
}
copy(unsafe.Slice((*byte)(unsafe.Pointer(r)), n), b[:n])
if r.Family != afHVSock {
return fmt.Errorf("got %d, want %d: %w", r.Family, afHVSock, socket.ErrAddrFamily)
}
return nil
}
// HvsockListener is a socket listener for the AF_HYPERV address family.
type HvsockListener struct {
sock *win32File
addr HvsockAddr
}
var _ net.Listener = &HvsockListener{}
// HvsockConn is a connected socket of the AF_HYPERV address family.
type HvsockConn struct {
sock *win32File
local, remote HvsockAddr
}
var _ net.Conn = &HvsockConn{}
func newHVSocket() (*win32File, error) {
fd, err := windows.Socket(afHVSock, windows.SOCK_STREAM, 1)
if err != nil {
return nil, os.NewSyscallError("socket", err)
}
f, err := makeWin32File(fd)
if err != nil {
windows.Close(fd)
return nil, err
}
f.socket = true
return f, nil
}
// ListenHvsock listens for connections on the specified hvsock address.
func ListenHvsock(addr *HvsockAddr) (_ *HvsockListener, err error) {
l := &HvsockListener{addr: *addr}
var sock *win32File
sock, err = newHVSocket()
if err != nil {
return nil, l.opErr("listen", err)
}
defer func() {
if err != nil {
_ = sock.Close()
}
}()
sa := addr.raw()
err = socket.Bind(sock.handle, &sa)
if err != nil {
return nil, l.opErr("listen", os.NewSyscallError("socket", err))
}
err = windows.Listen(sock.handle, 16)
if err != nil {
return nil, l.opErr("listen", os.NewSyscallError("listen", err))
}
return &HvsockListener{sock: sock, addr: *addr}, nil
}
func (l *HvsockListener) opErr(op string, err error) error {
return &net.OpError{Op: op, Net: "hvsock", Addr: &l.addr, Err: err}
}
// Addr returns the listener's network address.
func (l *HvsockListener) Addr() net.Addr {
return &l.addr
}
// Accept waits for the next connection and returns it.
func (l *HvsockListener) Accept() (_ net.Conn, err error) {
sock, err := newHVSocket()
if err != nil {
return nil, l.opErr("accept", err)
}
defer func() {
if sock != nil {
sock.Close()
}
}()
c, err := l.sock.prepareIO()
if err != nil {
return nil, l.opErr("accept", err)
}
defer l.sock.wg.Done()
// AcceptEx, per documentation, requires an extra 16 bytes per address.
//
// https://docs.microsoft.com/en-us/windows/win32/api/mswsock/nf-mswsock-acceptex
const addrlen = uint32(16 + unsafe.Sizeof(rawHvsockAddr{}))
var addrbuf [addrlen * 2]byte
var bytes uint32
err = windows.AcceptEx(l.sock.handle, sock.handle, &addrbuf[0], 0 /* rxdatalen */, addrlen, addrlen, &bytes, &c.o)
if _, err = l.sock.asyncIO(c, nil, bytes, err); err != nil {
return nil, l.opErr("accept", os.NewSyscallError("acceptex", err))
}
conn := &HvsockConn{
sock: sock,
}
// The local address returned in the AcceptEx buffer is the same as the Listener socket's
// address. However, the service GUID reported by GetSockName is different from the Listeners
// socket, and is sometimes the same as the local address of the socket that dialed the
// address, with the service GUID.Data1 incremented, but othertimes is different.
// todo: does the local address matter? is the listener's address or the actual address appropriate?
conn.local.fromRaw((*rawHvsockAddr)(unsafe.Pointer(&addrbuf[0])))
conn.remote.fromRaw((*rawHvsockAddr)(unsafe.Pointer(&addrbuf[addrlen])))
// initialize the accepted socket and update its properties with those of the listening socket
if err = windows.Setsockopt(sock.handle,
windows.SOL_SOCKET, windows.SO_UPDATE_ACCEPT_CONTEXT,
(*byte)(unsafe.Pointer(&l.sock.handle)), int32(unsafe.Sizeof(l.sock.handle))); err != nil {
return nil, conn.opErr("accept", os.NewSyscallError("setsockopt", err))
}
sock = nil
return conn, nil
}
// Close closes the listener, causing any pending Accept calls to fail.
func (l *HvsockListener) Close() error {
return l.sock.Close()
}
// HvsockDialer configures and dials a Hyper-V Socket (ie, [HvsockConn]).
type HvsockDialer struct {
// Deadline is the time the Dial operation must connect before erroring.
Deadline time.Time
// Retries is the number of additional connects to try if the connection times out, is refused,
// or the host is unreachable
Retries uint
// RetryWait is the time to wait after a connection error to retry
RetryWait time.Duration
rt *time.Timer // redial wait timer
}
// Dial the Hyper-V socket at addr.
//
// See [HvsockDialer.Dial] for more information.
func Dial(ctx context.Context, addr *HvsockAddr) (conn *HvsockConn, err error) {
return (&HvsockDialer{}).Dial(ctx, addr)
}
// Dial attempts to connect to the Hyper-V socket at addr, and returns a connection if successful.
// Will attempt (HvsockDialer).Retries if dialing fails, waiting (HvsockDialer).RetryWait between
// retries.
//
// Dialing can be cancelled either by providing (HvsockDialer).Deadline, or cancelling ctx.
func (d *HvsockDialer) Dial(ctx context.Context, addr *HvsockAddr) (conn *HvsockConn, err error) {
op := "dial"
// create the conn early to use opErr()
conn = &HvsockConn{
remote: *addr,
}
if !d.Deadline.IsZero() {
var cancel context.CancelFunc
ctx, cancel = context.WithDeadline(ctx, d.Deadline)
defer cancel()
}
// preemptive timeout/cancellation check
if err = ctx.Err(); err != nil {
return nil, conn.opErr(op, err)
}
sock, err := newHVSocket()
if err != nil {
return nil, conn.opErr(op, err)
}
defer func() {
if sock != nil {
sock.Close()
}
}()
sa := addr.raw()
err = socket.Bind(sock.handle, &sa)
if err != nil {
return nil, conn.opErr(op, os.NewSyscallError("bind", err))
}
c, err := sock.prepareIO()
if err != nil {
return nil, conn.opErr(op, err)
}
defer sock.wg.Done()
var bytes uint32
for i := uint(0); i <= d.Retries; i++ {
err = socket.ConnectEx(
sock.handle,
&sa,
nil, // sendBuf
0, // sendDataLen
&bytes,
(*windows.Overlapped)(unsafe.Pointer(&c.o)))
_, err = sock.asyncIO(c, nil, bytes, err)
if i < d.Retries && canRedial(err) {
if err = d.redialWait(ctx); err == nil {
continue
}
}
break
}
if err != nil {
return nil, conn.opErr(op, os.NewSyscallError("connectex", err))
}
// update the connection properties, so shutdown can be used
if err = windows.Setsockopt(
sock.handle,
windows.SOL_SOCKET,
windows.SO_UPDATE_CONNECT_CONTEXT,
nil, // optvalue
0, // optlen
); err != nil {
return nil, conn.opErr(op, os.NewSyscallError("setsockopt", err))
}
// get the local name
var sal rawHvsockAddr
err = socket.GetSockName(sock.handle, &sal)
if err != nil {
return nil, conn.opErr(op, os.NewSyscallError("getsockname", err))
}
conn.local.fromRaw(&sal)
// one last check for timeout, since asyncIO doesn't check the context
if err = ctx.Err(); err != nil {
return nil, conn.opErr(op, err)
}
conn.sock = sock
sock = nil
return conn, nil
}
// redialWait waits before attempting to redial, resetting the timer as appropriate.
func (d *HvsockDialer) redialWait(ctx context.Context) (err error) {
if d.RetryWait == 0 {
return nil
}
if d.rt == nil {
d.rt = time.NewTimer(d.RetryWait)
} else {
// should already be stopped and drained
d.rt.Reset(d.RetryWait)
}
select {
case <-ctx.Done():
case <-d.rt.C:
return nil
}
// stop and drain the timer
if !d.rt.Stop() {
<-d.rt.C
}
return ctx.Err()
}
// assumes error is a plain, unwrapped windows.Errno provided by direct syscall.
func canRedial(err error) bool {
//nolint:errorlint // guaranteed to be an Errno
switch err {
case windows.WSAECONNREFUSED, windows.WSAENETUNREACH, windows.WSAETIMEDOUT,
windows.ERROR_CONNECTION_REFUSED, windows.ERROR_CONNECTION_UNAVAIL:
return true
default:
return false
}
}
func (conn *HvsockConn) opErr(op string, err error) error {
// translate from "file closed" to "socket closed"
if errors.Is(err, ErrFileClosed) {
err = socket.ErrSocketClosed
}
return &net.OpError{Op: op, Net: "hvsock", Source: &conn.local, Addr: &conn.remote, Err: err}
}
func (conn *HvsockConn) Read(b []byte) (int, error) {
c, err := conn.sock.prepareIO()
if err != nil {
return 0, conn.opErr("read", err)
}
defer conn.sock.wg.Done()
buf := windows.WSABuf{Buf: &b[0], Len: uint32(len(b))}
var flags, bytes uint32
err = windows.WSARecv(conn.sock.handle, &buf, 1, &bytes, &flags, &c.o, nil)
n, err := conn.sock.asyncIO(c, &conn.sock.readDeadline, bytes, err)
if err != nil {
var eno windows.Errno
if errors.As(err, &eno) {
err = os.NewSyscallError("wsarecv", eno)
}
return 0, conn.opErr("read", err)
} else if n == 0 {
err = io.EOF
}
return n, err
}
func (conn *HvsockConn) Write(b []byte) (int, error) {
t := 0
for len(b) != 0 {
n, err := conn.write(b)
if err != nil {
return t + n, err
}
t += n
b = b[n:]
}
return t, nil
}
func (conn *HvsockConn) write(b []byte) (int, error) {
c, err := conn.sock.prepareIO()
if err != nil {
return 0, conn.opErr("write", err)
}
defer conn.sock.wg.Done()
buf := windows.WSABuf{Buf: &b[0], Len: uint32(len(b))}
var bytes uint32
err = windows.WSASend(conn.sock.handle, &buf, 1, &bytes, 0, &c.o, nil)
n, err := conn.sock.asyncIO(c, &conn.sock.writeDeadline, bytes, err)
if err != nil {
var eno windows.Errno
if errors.As(err, &eno) {
err = os.NewSyscallError("wsasend", eno)
}
return 0, conn.opErr("write", err)
}
return n, err
}
// Close closes the socket connection, failing any pending read or write calls.
func (conn *HvsockConn) Close() error {
return conn.sock.Close()
}
func (conn *HvsockConn) IsClosed() bool {
return conn.sock.IsClosed()
}
// shutdown disables sending or receiving on a socket.
func (conn *HvsockConn) shutdown(how int) error {
if conn.IsClosed() {
return socket.ErrSocketClosed
}
err := windows.Shutdown(conn.sock.handle, how)
if err != nil {
// If the connection was closed, shutdowns fail with "not connected"
if errors.Is(err, windows.WSAENOTCONN) ||
errors.Is(err, windows.WSAESHUTDOWN) {
err = socket.ErrSocketClosed
}
return os.NewSyscallError("shutdown", err)
}
return nil
}
// CloseRead shuts down the read end of the socket, preventing future read operations.
func (conn *HvsockConn) CloseRead() error {
err := conn.shutdown(windows.SHUT_RD)
if err != nil {
return conn.opErr("closeread", err)
}
return nil
}
// CloseWrite shuts down the write end of the socket, preventing future write operations and
// notifying the other endpoint that no more data will be written.
func (conn *HvsockConn) CloseWrite() error {
err := conn.shutdown(windows.SHUT_WR)
if err != nil {
return conn.opErr("closewrite", err)
}
return nil
}
// LocalAddr returns the local address of the connection.
func (conn *HvsockConn) LocalAddr() net.Addr {
return &conn.local
}
// RemoteAddr returns the remote address of the connection.
func (conn *HvsockConn) RemoteAddr() net.Addr {
return &conn.remote
}
// SetDeadline implements the net.Conn SetDeadline method.
func (conn *HvsockConn) SetDeadline(t time.Time) error {
// todo: implement `SetDeadline` for `win32File`
if err := conn.SetReadDeadline(t); err != nil {
return fmt.Errorf("set read deadline: %w", err)
}
if err := conn.SetWriteDeadline(t); err != nil {
return fmt.Errorf("set write deadline: %w", err)
}
return nil
}
// SetReadDeadline implements the net.Conn SetReadDeadline method.
func (conn *HvsockConn) SetReadDeadline(t time.Time) error {
return conn.sock.SetReadDeadline(t)
}
// SetWriteDeadline implements the net.Conn SetWriteDeadline method.
func (conn *HvsockConn) SetWriteDeadline(t time.Time) error {
return conn.sock.SetWriteDeadline(t)
}
Codebase Browser
kubernetes