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-rwxr-xr-xpkg/tcpip/adapters/gonet/gonet.go722
1 files changed, 722 insertions, 0 deletions
diff --git a/pkg/tcpip/adapters/gonet/gonet.go b/pkg/tcpip/adapters/gonet/gonet.go
new file mode 100755
index 000000000..cd6ce930a
--- /dev/null
+++ b/pkg/tcpip/adapters/gonet/gonet.go
@@ -0,0 +1,722 @@
+// Copyright 2018 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package gonet provides a Go net package compatible wrapper for a tcpip stack.
+package gonet
+
+import (
+ "context"
+ "errors"
+ "io"
+ "net"
+ "sync"
+ "time"
+
+ "gvisor.dev/gvisor/pkg/tcpip"
+ "gvisor.dev/gvisor/pkg/tcpip/buffer"
+ "gvisor.dev/gvisor/pkg/tcpip/stack"
+ "gvisor.dev/gvisor/pkg/tcpip/transport/tcp"
+ "gvisor.dev/gvisor/pkg/tcpip/transport/udp"
+ "gvisor.dev/gvisor/pkg/waiter"
+)
+
+var (
+ errCanceled = errors.New("operation canceled")
+ errWouldBlock = errors.New("operation would block")
+)
+
+// timeoutError is how the net package reports timeouts.
+type timeoutError struct{}
+
+func (e *timeoutError) Error() string { return "i/o timeout" }
+func (e *timeoutError) Timeout() bool { return true }
+func (e *timeoutError) Temporary() bool { return true }
+
+// A Listener is a wrapper around a tcpip endpoint that implements
+// net.Listener.
+type Listener struct {
+ stack *stack.Stack
+ ep tcpip.Endpoint
+ wq *waiter.Queue
+ cancel chan struct{}
+}
+
+// NewListener creates a new Listener.
+func NewListener(s *stack.Stack, addr tcpip.FullAddress, network tcpip.NetworkProtocolNumber) (*Listener, error) {
+ // Create TCP endpoint, bind it, then start listening.
+ var wq waiter.Queue
+ ep, err := s.NewEndpoint(tcp.ProtocolNumber, network, &wq)
+ if err != nil {
+ return nil, errors.New(err.String())
+ }
+
+ if err := ep.Bind(addr); err != nil {
+ ep.Close()
+ return nil, &net.OpError{
+ Op: "bind",
+ Net: "tcp",
+ Addr: fullToTCPAddr(addr),
+ Err: errors.New(err.String()),
+ }
+ }
+
+ if err := ep.Listen(10); err != nil {
+ ep.Close()
+ return nil, &net.OpError{
+ Op: "listen",
+ Net: "tcp",
+ Addr: fullToTCPAddr(addr),
+ Err: errors.New(err.String()),
+ }
+ }
+
+ return &Listener{
+ stack: s,
+ ep: ep,
+ wq: &wq,
+ cancel: make(chan struct{}),
+ }, nil
+}
+
+// Close implements net.Listener.Close.
+func (l *Listener) Close() error {
+ l.ep.Close()
+ return nil
+}
+
+// Shutdown stops the HTTP server.
+func (l *Listener) Shutdown() {
+ l.ep.Shutdown(tcpip.ShutdownWrite | tcpip.ShutdownRead)
+ close(l.cancel) // broadcast cancellation
+}
+
+// Addr implements net.Listener.Addr.
+func (l *Listener) Addr() net.Addr {
+ a, err := l.ep.GetLocalAddress()
+ if err != nil {
+ return nil
+ }
+ return fullToTCPAddr(a)
+}
+
+type deadlineTimer struct {
+ // mu protects the fields below.
+ mu sync.Mutex
+
+ readTimer *time.Timer
+ readCancelCh chan struct{}
+ writeTimer *time.Timer
+ writeCancelCh chan struct{}
+}
+
+func (d *deadlineTimer) init() {
+ d.readCancelCh = make(chan struct{})
+ d.writeCancelCh = make(chan struct{})
+}
+
+func (d *deadlineTimer) readCancel() <-chan struct{} {
+ d.mu.Lock()
+ c := d.readCancelCh
+ d.mu.Unlock()
+ return c
+}
+func (d *deadlineTimer) writeCancel() <-chan struct{} {
+ d.mu.Lock()
+ c := d.writeCancelCh
+ d.mu.Unlock()
+ return c
+}
+
+// setDeadline contains the shared logic for setting a deadline.
+//
+// cancelCh and timer must be pointers to deadlineTimer.readCancelCh and
+// deadlineTimer.readTimer or deadlineTimer.writeCancelCh and
+// deadlineTimer.writeTimer.
+//
+// setDeadline must only be called while holding d.mu.
+func (d *deadlineTimer) setDeadline(cancelCh *chan struct{}, timer **time.Timer, t time.Time) {
+ if *timer != nil && !(*timer).Stop() {
+ *cancelCh = make(chan struct{})
+ }
+
+ // Create a new channel if we already closed it due to setting an already
+ // expired time. We won't race with the timer because we already handled
+ // that above.
+ select {
+ case <-*cancelCh:
+ *cancelCh = make(chan struct{})
+ default:
+ }
+
+ // "A zero value for t means I/O operations will not time out."
+ // - net.Conn.SetDeadline
+ if t.IsZero() {
+ return
+ }
+
+ timeout := t.Sub(time.Now())
+ if timeout <= 0 {
+ close(*cancelCh)
+ return
+ }
+
+ // Timer.Stop returns whether or not the AfterFunc has started, but
+ // does not indicate whether or not it has completed. Make a copy of
+ // the cancel channel to prevent this code from racing with the next
+ // call of setDeadline replacing *cancelCh.
+ ch := *cancelCh
+ *timer = time.AfterFunc(timeout, func() {
+ close(ch)
+ })
+}
+
+// SetReadDeadline implements net.Conn.SetReadDeadline and
+// net.PacketConn.SetReadDeadline.
+func (d *deadlineTimer) SetReadDeadline(t time.Time) error {
+ d.mu.Lock()
+ d.setDeadline(&d.readCancelCh, &d.readTimer, t)
+ d.mu.Unlock()
+ return nil
+}
+
+// SetWriteDeadline implements net.Conn.SetWriteDeadline and
+// net.PacketConn.SetWriteDeadline.
+func (d *deadlineTimer) SetWriteDeadline(t time.Time) error {
+ d.mu.Lock()
+ d.setDeadline(&d.writeCancelCh, &d.writeTimer, t)
+ d.mu.Unlock()
+ return nil
+}
+
+// SetDeadline implements net.Conn.SetDeadline and net.PacketConn.SetDeadline.
+func (d *deadlineTimer) SetDeadline(t time.Time) error {
+ d.mu.Lock()
+ d.setDeadline(&d.readCancelCh, &d.readTimer, t)
+ d.setDeadline(&d.writeCancelCh, &d.writeTimer, t)
+ d.mu.Unlock()
+ return nil
+}
+
+// A Conn is a wrapper around a tcpip.Endpoint that implements the net.Conn
+// interface.
+type Conn struct {
+ deadlineTimer
+
+ wq *waiter.Queue
+ ep tcpip.Endpoint
+
+ // readMu serializes reads and implicitly protects read.
+ //
+ // Lock ordering:
+ // If both readMu and deadlineTimer.mu are to be used in a single
+ // request, readMu must be acquired before deadlineTimer.mu.
+ readMu sync.Mutex
+
+ // read contains bytes that have been read from the endpoint,
+ // but haven't yet been returned.
+ read buffer.View
+}
+
+// NewConn creates a new Conn.
+func NewConn(wq *waiter.Queue, ep tcpip.Endpoint) *Conn {
+ c := &Conn{
+ wq: wq,
+ ep: ep,
+ }
+ c.deadlineTimer.init()
+ return c
+}
+
+// Accept implements net.Conn.Accept.
+func (l *Listener) Accept() (net.Conn, error) {
+ n, wq, err := l.ep.Accept()
+
+ if err == tcpip.ErrWouldBlock {
+ // Create wait queue entry that notifies a channel.
+ waitEntry, notifyCh := waiter.NewChannelEntry(nil)
+ l.wq.EventRegister(&waitEntry, waiter.EventIn)
+ defer l.wq.EventUnregister(&waitEntry)
+
+ for {
+ n, wq, err = l.ep.Accept()
+
+ if err != tcpip.ErrWouldBlock {
+ break
+ }
+
+ select {
+ case <-l.cancel:
+ return nil, errCanceled
+ case <-notifyCh:
+ }
+ }
+ }
+
+ if err != nil {
+ return nil, &net.OpError{
+ Op: "accept",
+ Net: "tcp",
+ Addr: l.Addr(),
+ Err: errors.New(err.String()),
+ }
+ }
+
+ return NewConn(wq, n), nil
+}
+
+type opErrorer interface {
+ newOpError(op string, err error) *net.OpError
+}
+
+// commonRead implements the common logic between net.Conn.Read and
+// net.PacketConn.ReadFrom.
+func commonRead(ep tcpip.Endpoint, wq *waiter.Queue, deadline <-chan struct{}, addr *tcpip.FullAddress, errorer opErrorer, dontWait bool) ([]byte, error) {
+ select {
+ case <-deadline:
+ return nil, errorer.newOpError("read", &timeoutError{})
+ default:
+ }
+
+ read, _, err := ep.Read(addr)
+
+ if err == tcpip.ErrWouldBlock {
+ if dontWait {
+ return nil, errWouldBlock
+ }
+ // Create wait queue entry that notifies a channel.
+ waitEntry, notifyCh := waiter.NewChannelEntry(nil)
+ wq.EventRegister(&waitEntry, waiter.EventIn)
+ defer wq.EventUnregister(&waitEntry)
+ for {
+ read, _, err = ep.Read(addr)
+ if err != tcpip.ErrWouldBlock {
+ break
+ }
+ select {
+ case <-deadline:
+ return nil, errorer.newOpError("read", &timeoutError{})
+ case <-notifyCh:
+ }
+ }
+ }
+
+ if err == tcpip.ErrClosedForReceive {
+ return nil, io.EOF
+ }
+
+ if err != nil {
+ return nil, errorer.newOpError("read", errors.New(err.String()))
+ }
+
+ return read, nil
+}
+
+// Read implements net.Conn.Read.
+func (c *Conn) Read(b []byte) (int, error) {
+ c.readMu.Lock()
+ defer c.readMu.Unlock()
+
+ deadline := c.readCancel()
+
+ numRead := 0
+ for numRead != len(b) {
+ if len(c.read) == 0 {
+ var err error
+ c.read, err = commonRead(c.ep, c.wq, deadline, nil, c, numRead != 0)
+ if err != nil {
+ if numRead != 0 {
+ return numRead, nil
+ }
+ return numRead, err
+ }
+ }
+ n := copy(b[numRead:], c.read)
+ c.read.TrimFront(n)
+ numRead += n
+ if len(c.read) == 0 {
+ c.read = nil
+ }
+ }
+ return numRead, nil
+}
+
+// Write implements net.Conn.Write.
+func (c *Conn) Write(b []byte) (int, error) {
+ deadline := c.writeCancel()
+
+ // Check if deadlineTimer has already expired.
+ select {
+ case <-deadline:
+ return 0, c.newOpError("write", &timeoutError{})
+ default:
+ }
+
+ v := buffer.NewViewFromBytes(b)
+
+ // We must handle two soft failure conditions simultaneously:
+ // 1. Write may write nothing and return tcpip.ErrWouldBlock.
+ // If this happens, we need to register for notifications if we have
+ // not already and wait to try again.
+ // 2. Write may write fewer than the full number of bytes and return
+ // without error. In this case we need to try writing the remaining
+ // bytes again. I do not need to register for notifications.
+ //
+ // What is more, these two soft failure conditions can be interspersed.
+ // There is no guarantee that all of the condition #1s will occur before
+ // all of the condition #2s or visa-versa.
+ var (
+ err *tcpip.Error
+ nbytes int
+ reg bool
+ notifyCh chan struct{}
+ )
+ for nbytes < len(b) && (err == tcpip.ErrWouldBlock || err == nil) {
+ if err == tcpip.ErrWouldBlock {
+ if !reg {
+ // Only register once.
+ reg = true
+
+ // Create wait queue entry that notifies a channel.
+ var waitEntry waiter.Entry
+ waitEntry, notifyCh = waiter.NewChannelEntry(nil)
+ c.wq.EventRegister(&waitEntry, waiter.EventOut)
+ defer c.wq.EventUnregister(&waitEntry)
+ } else {
+ // Don't wait immediately after registration in case more data
+ // became available between when we last checked and when we setup
+ // the notification.
+ select {
+ case <-deadline:
+ return nbytes, c.newOpError("write", &timeoutError{})
+ case <-notifyCh:
+ }
+ }
+ }
+
+ var n int64
+ var resCh <-chan struct{}
+ n, resCh, err = c.ep.Write(tcpip.SlicePayload(v), tcpip.WriteOptions{})
+ nbytes += int(n)
+ v.TrimFront(int(n))
+
+ if resCh != nil {
+ select {
+ case <-deadline:
+ return nbytes, c.newOpError("write", &timeoutError{})
+ case <-resCh:
+ }
+
+ n, _, err = c.ep.Write(tcpip.SlicePayload(v), tcpip.WriteOptions{})
+ nbytes += int(n)
+ v.TrimFront(int(n))
+ }
+ }
+
+ if err == nil {
+ return nbytes, nil
+ }
+
+ return nbytes, c.newOpError("write", errors.New(err.String()))
+}
+
+// Close implements net.Conn.Close.
+func (c *Conn) Close() error {
+ c.ep.Close()
+ return nil
+}
+
+// CloseRead shuts down the reading side of the TCP connection. Most callers
+// should just use Close.
+//
+// A TCP Half-Close is performed the same as CloseRead for *net.TCPConn.
+func (c *Conn) CloseRead() error {
+ if terr := c.ep.Shutdown(tcpip.ShutdownRead); terr != nil {
+ return c.newOpError("close", errors.New(terr.String()))
+ }
+ return nil
+}
+
+// CloseWrite shuts down the writing side of the TCP connection. Most callers
+// should just use Close.
+//
+// A TCP Half-Close is performed the same as CloseWrite for *net.TCPConn.
+func (c *Conn) CloseWrite() error {
+ if terr := c.ep.Shutdown(tcpip.ShutdownWrite); terr != nil {
+ return c.newOpError("close", errors.New(terr.String()))
+ }
+ return nil
+}
+
+// LocalAddr implements net.Conn.LocalAddr.
+func (c *Conn) LocalAddr() net.Addr {
+ a, err := c.ep.GetLocalAddress()
+ if err != nil {
+ return nil
+ }
+ return fullToTCPAddr(a)
+}
+
+// RemoteAddr implements net.Conn.RemoteAddr.
+func (c *Conn) RemoteAddr() net.Addr {
+ a, err := c.ep.GetRemoteAddress()
+ if err != nil {
+ return nil
+ }
+ return fullToTCPAddr(a)
+}
+
+func (c *Conn) newOpError(op string, err error) *net.OpError {
+ return &net.OpError{
+ Op: op,
+ Net: "tcp",
+ Source: c.LocalAddr(),
+ Addr: c.RemoteAddr(),
+ Err: err,
+ }
+}
+
+func fullToTCPAddr(addr tcpip.FullAddress) *net.TCPAddr {
+ return &net.TCPAddr{IP: net.IP(addr.Addr), Port: int(addr.Port)}
+}
+
+func fullToUDPAddr(addr tcpip.FullAddress) *net.UDPAddr {
+ return &net.UDPAddr{IP: net.IP(addr.Addr), Port: int(addr.Port)}
+}
+
+// DialTCP creates a new TCP Conn connected to the specified address.
+func DialTCP(s *stack.Stack, addr tcpip.FullAddress, network tcpip.NetworkProtocolNumber) (*Conn, error) {
+ return DialContextTCP(context.Background(), s, addr, network)
+}
+
+// DialContextTCP creates a new TCP Conn connected to the specified address
+// with the option of adding cancellation and timeouts.
+func DialContextTCP(ctx context.Context, s *stack.Stack, addr tcpip.FullAddress, network tcpip.NetworkProtocolNumber) (*Conn, error) {
+ // Create TCP endpoint, then connect.
+ var wq waiter.Queue
+ ep, err := s.NewEndpoint(tcp.ProtocolNumber, network, &wq)
+ if err != nil {
+ return nil, errors.New(err.String())
+ }
+
+ // Create wait queue entry that notifies a channel.
+ //
+ // We do this unconditionally as Connect will always return an error.
+ waitEntry, notifyCh := waiter.NewChannelEntry(nil)
+ wq.EventRegister(&waitEntry, waiter.EventOut)
+ defer wq.EventUnregister(&waitEntry)
+
+ select {
+ case <-ctx.Done():
+ return nil, ctx.Err()
+ default:
+ }
+
+ err = ep.Connect(addr)
+ if err == tcpip.ErrConnectStarted {
+ select {
+ case <-ctx.Done():
+ ep.Close()
+ return nil, ctx.Err()
+ case <-notifyCh:
+ }
+
+ err = ep.GetSockOpt(tcpip.ErrorOption{})
+ }
+ if err != nil {
+ ep.Close()
+ return nil, &net.OpError{
+ Op: "connect",
+ Net: "tcp",
+ Addr: fullToTCPAddr(addr),
+ Err: errors.New(err.String()),
+ }
+ }
+
+ return NewConn(&wq, ep), nil
+}
+
+// A PacketConn is a wrapper around a tcpip endpoint that implements
+// net.PacketConn.
+type PacketConn struct {
+ deadlineTimer
+
+ stack *stack.Stack
+ ep tcpip.Endpoint
+ wq *waiter.Queue
+}
+
+// DialUDP creates a new PacketConn.
+//
+// If laddr is nil, a local address is automatically chosen.
+//
+// If raddr is nil, the PacketConn is left unconnected.
+func DialUDP(s *stack.Stack, laddr, raddr *tcpip.FullAddress, network tcpip.NetworkProtocolNumber) (*PacketConn, error) {
+ var wq waiter.Queue
+ ep, err := s.NewEndpoint(udp.ProtocolNumber, network, &wq)
+ if err != nil {
+ return nil, errors.New(err.String())
+ }
+
+ if laddr != nil {
+ if err := ep.Bind(*laddr); err != nil {
+ ep.Close()
+ return nil, &net.OpError{
+ Op: "bind",
+ Net: "udp",
+ Addr: fullToUDPAddr(*laddr),
+ Err: errors.New(err.String()),
+ }
+ }
+ }
+
+ c := PacketConn{
+ stack: s,
+ ep: ep,
+ wq: &wq,
+ }
+ c.deadlineTimer.init()
+
+ if raddr != nil {
+ if err := c.ep.Connect(*raddr); err != nil {
+ c.ep.Close()
+ return nil, &net.OpError{
+ Op: "connect",
+ Net: "udp",
+ Addr: fullToUDPAddr(*raddr),
+ Err: errors.New(err.String()),
+ }
+ }
+ }
+
+ return &c, nil
+}
+
+func (c *PacketConn) newOpError(op string, err error) *net.OpError {
+ return c.newRemoteOpError(op, nil, err)
+}
+
+func (c *PacketConn) newRemoteOpError(op string, remote net.Addr, err error) *net.OpError {
+ return &net.OpError{
+ Op: op,
+ Net: "udp",
+ Source: c.LocalAddr(),
+ Addr: remote,
+ Err: err,
+ }
+}
+
+// RemoteAddr implements net.Conn.RemoteAddr.
+func (c *PacketConn) RemoteAddr() net.Addr {
+ a, err := c.ep.GetRemoteAddress()
+ if err != nil {
+ return nil
+ }
+ return fullToTCPAddr(a)
+}
+
+// Read implements net.Conn.Read
+func (c *PacketConn) Read(b []byte) (int, error) {
+ bytesRead, _, err := c.ReadFrom(b)
+ return bytesRead, err
+}
+
+// ReadFrom implements net.PacketConn.ReadFrom.
+func (c *PacketConn) ReadFrom(b []byte) (int, net.Addr, error) {
+ deadline := c.readCancel()
+
+ var addr tcpip.FullAddress
+ read, err := commonRead(c.ep, c.wq, deadline, &addr, c, false)
+ if err != nil {
+ return 0, nil, err
+ }
+
+ return copy(b, read), fullToUDPAddr(addr), nil
+}
+
+func (c *PacketConn) Write(b []byte) (int, error) {
+ return c.WriteTo(b, nil)
+}
+
+// WriteTo implements net.PacketConn.WriteTo.
+func (c *PacketConn) WriteTo(b []byte, addr net.Addr) (int, error) {
+ deadline := c.writeCancel()
+
+ // Check if deadline has already expired.
+ select {
+ case <-deadline:
+ return 0, c.newRemoteOpError("write", addr, &timeoutError{})
+ default:
+ }
+
+ // If we're being called by Write, there is no addr
+ wopts := tcpip.WriteOptions{}
+ if addr != nil {
+ ua := addr.(*net.UDPAddr)
+ wopts.To = &tcpip.FullAddress{Addr: tcpip.Address(ua.IP), Port: uint16(ua.Port)}
+ }
+
+ v := buffer.NewView(len(b))
+ copy(v, b)
+
+ n, resCh, err := c.ep.Write(tcpip.SlicePayload(v), wopts)
+ if resCh != nil {
+ select {
+ case <-deadline:
+ return int(n), c.newRemoteOpError("write", addr, &timeoutError{})
+ case <-resCh:
+ }
+
+ n, _, err = c.ep.Write(tcpip.SlicePayload(v), wopts)
+ }
+
+ if err == tcpip.ErrWouldBlock {
+ // Create wait queue entry that notifies a channel.
+ waitEntry, notifyCh := waiter.NewChannelEntry(nil)
+ c.wq.EventRegister(&waitEntry, waiter.EventOut)
+ defer c.wq.EventUnregister(&waitEntry)
+ for {
+ select {
+ case <-deadline:
+ return int(n), c.newRemoteOpError("write", addr, &timeoutError{})
+ case <-notifyCh:
+ }
+
+ n, _, err = c.ep.Write(tcpip.SlicePayload(v), wopts)
+ if err != tcpip.ErrWouldBlock {
+ break
+ }
+ }
+ }
+
+ if err == nil {
+ return int(n), nil
+ }
+
+ return int(n), c.newRemoteOpError("write", addr, errors.New(err.String()))
+}
+
+// Close implements net.PacketConn.Close.
+func (c *PacketConn) Close() error {
+ c.ep.Close()
+ return nil
+}
+
+// LocalAddr implements net.PacketConn.LocalAddr.
+func (c *PacketConn) LocalAddr() net.Addr {
+ a, err := c.ep.GetLocalAddress()
+ if err != nil {
+ return nil
+ }
+ return fullToUDPAddr(a)
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-01 18:13:51 +0000