diff options
Diffstat (limited to 'pkg/tcpip/adapters/gonet/gonet.go')
-rw-r--r-- | pkg/tcpip/adapters/gonet/gonet.go | 704 |
1 files changed, 0 insertions, 704 deletions
diff --git a/pkg/tcpip/adapters/gonet/gonet.go b/pkg/tcpip/adapters/gonet/gonet.go deleted file mode 100644 index 308f620e5..000000000 --- a/pkg/tcpip/adapters/gonet/gonet.go +++ /dev/null @@ -1,704 +0,0 @@ -// 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 uintptr - 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 -} - -// NewPacketConn creates a new PacketConn. -func NewPacketConn(s *stack.Stack, addr tcpip.FullAddress, network tcpip.NetworkProtocolNumber) (*PacketConn, error) { - // Create UDP endpoint and bind it. - var wq waiter.Queue - ep, err := s.NewEndpoint(udp.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: "udp", - Addr: fullToUDPAddr(addr), - Err: errors.New(err.String()), - } - } - - c := &PacketConn{ - stack: s, - ep: ep, - wq: &wq, - } - c.deadlineTimer.init() - 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) -} |