summaryrefslogtreecommitdiffhomepage
path: root/pkg/unet
diff options
context:
space:
mode:
Diffstat (limited to 'pkg/unet')
-rw-r--r--pkg/unet/BUILD26
-rw-r--r--pkg/unet/unet.go569
-rw-r--r--pkg/unet/unet_test.go693
-rw-r--r--pkg/unet/unet_unsafe.go287
4 files changed, 1575 insertions, 0 deletions
diff --git a/pkg/unet/BUILD b/pkg/unet/BUILD
new file mode 100644
index 000000000..e8e40315a
--- /dev/null
+++ b/pkg/unet/BUILD
@@ -0,0 +1,26 @@
+package(licenses = ["notice"]) # Apache 2.0
+
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+go_library(
+ name = "unet",
+ srcs = [
+ "unet.go",
+ "unet_unsafe.go",
+ ],
+ importpath = "gvisor.googlesource.com/gvisor/pkg/unet",
+ visibility = ["//visibility:public"],
+ deps = [
+ "//pkg/abi/linux",
+ "//pkg/gate",
+ ],
+)
+
+go_test(
+ name = "unet_test",
+ size = "small",
+ srcs = [
+ "unet_test.go",
+ ],
+ embed = [":unet"],
+)
diff --git a/pkg/unet/unet.go b/pkg/unet/unet.go
new file mode 100644
index 000000000..59b6c5568
--- /dev/null
+++ b/pkg/unet/unet.go
@@ -0,0 +1,569 @@
+// Copyright 2018 Google Inc.
+//
+// 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 unet provides a minimal net package based on Unix Domain Sockets.
+//
+// This does no pooling, and should only be used for a limited number of
+// connections in a Go process. Don't use this package for arbitrary servers.
+package unet
+
+import (
+ "errors"
+ "sync/atomic"
+ "syscall"
+
+ "gvisor.googlesource.com/gvisor/pkg/gate"
+)
+
+// backlog is used for the listen request.
+const backlog = 16
+
+// errClosing is returned by wait if the Socket is in the process of closing.
+var errClosing = errors.New("Socket is closing")
+
+// errMessageTruncated indicates that data was lost because the provided buffer
+// was too small.
+var errMessageTruncated = errors.New("message truncated")
+
+// socketType returns the appropriate type.
+func socketType(packet bool) int {
+ if packet {
+ return syscall.SOCK_SEQPACKET
+ }
+ return syscall.SOCK_STREAM
+}
+
+// socket creates a new host socket.
+func socket(packet bool) (int, error) {
+ // Make a new socket.
+ fd, err := syscall.Socket(syscall.AF_UNIX, socketType(packet), 0)
+ if err != nil {
+ return 0, err
+ }
+
+ return fd, nil
+}
+
+// eventFD returns a new event FD with initial value 0.
+func eventFD() (int, error) {
+ f, _, e := syscall.Syscall(syscall.SYS_EVENTFD2, 0, 0, 0)
+ if e != 0 {
+ return -1, e
+ }
+ return int(f), nil
+}
+
+// Socket is a connected unix domain socket.
+type Socket struct {
+ // gate protects use of fd.
+ gate gate.Gate
+
+ // fd is the bound socket.
+ //
+ // fd must be read atomically, and only remains valid if read while
+ // within gate.
+ fd int32
+
+ // efd is an event FD that is signaled when the socket is closing.
+ //
+ // efd is immutable and remains valid until Close/Release.
+ efd int
+
+ // race is an atomic variable used to avoid triggering the race
+ // detector. See comment in SocketPair below.
+ race *int32
+}
+
+// NewSocket returns a socket from an existing FD.
+//
+// NewSocket takes ownership of fd.
+func NewSocket(fd int) (*Socket, error) {
+ // fd must be non-blocking for non-blocking syscall.Accept in
+ // ServerSocket.Accept.
+ if err := syscall.SetNonblock(fd, true); err != nil {
+ return nil, err
+ }
+
+ efd, err := eventFD()
+ if err != nil {
+ return nil, err
+ }
+
+ return &Socket{
+ fd: int32(fd),
+ efd: efd,
+ }, nil
+}
+
+// finish completes use of s.fd by evicting any waiters, closing the gate, and
+// closing the event FD.
+func (s *Socket) finish() error {
+ // Signal any blocked or future polls.
+ //
+ // N.B. eventfd writes must be 8 bytes.
+ if _, err := syscall.Write(s.efd, []byte{1, 0, 0, 0, 0, 0, 0, 0}); err != nil {
+ return err
+ }
+
+ // Close the gate, blocking until all FD users leave.
+ s.gate.Close()
+
+ return syscall.Close(s.efd)
+}
+
+// Close closes the socket.
+func (s *Socket) Close() error {
+ // Set the FD in the socket to -1, to ensure that all future calls to
+ // FD/Release get nothing and Close calls return immediately.
+ fd := int(atomic.SwapInt32(&s.fd, -1))
+ if fd < 0 {
+ // Already closed or closing.
+ return syscall.EBADF
+ }
+
+ // Shutdown the socket to cancel any pending accepts.
+ s.shutdown(fd)
+
+ if err := s.finish(); err != nil {
+ return err
+ }
+
+ return syscall.Close(fd)
+}
+
+// Release releases ownership of the socket FD.
+//
+// The returned FD is non-blocking.
+//
+// Any concurrent or future callers of Socket methods will receive EBADF.
+func (s *Socket) Release() (int, error) {
+ // Set the FD in the socket to -1, to ensure that all future calls to
+ // FD/Release get nothing and Close calls return immediately.
+ fd := int(atomic.SwapInt32(&s.fd, -1))
+ if fd < 0 {
+ // Already closed or closing.
+ return -1, syscall.EBADF
+ }
+
+ if err := s.finish(); err != nil {
+ return -1, err
+ }
+
+ return fd, nil
+}
+
+// FD returns the FD for this Socket.
+//
+// The FD is non-blocking and must not be made blocking.
+//
+// N.B. os.File.Fd makes the FD blocking. Use of Release instead of FD is
+// strongly preferred.
+//
+// The returned FD cannot be used safely if there may be concurrent callers to
+// Close or Release.
+//
+// Use Release to take ownership of the FD.
+func (s *Socket) FD() int {
+ return int(atomic.LoadInt32(&s.fd))
+}
+
+// enterFD enters the FD gate and returns the FD value.
+//
+// If enterFD returns ok, s.gate.Leave must be called when done with the FD.
+// Callers may only block while within the gate using s.wait.
+//
+// The returned FD is guaranteed to remain valid until s.gate.Leave.
+func (s *Socket) enterFD() (int, bool) {
+ if !s.gate.Enter() {
+ return -1, false
+ }
+
+ fd := int(atomic.LoadInt32(&s.fd))
+ if fd < 0 {
+ s.gate.Leave()
+ return -1, false
+ }
+
+ return fd, true
+}
+
+// SocketPair creates a pair of connected sockets.
+func SocketPair(packet bool) (*Socket, *Socket, error) {
+ // Make a new pair.
+ fds, err := syscall.Socketpair(syscall.AF_UNIX, socketType(packet), 0)
+ if err != nil {
+ return nil, nil, err
+ }
+
+ // race is an atomic variable used to avoid triggering the race
+ // detector. We have to fool TSAN into thinking there is a race
+ // variable between our two sockets. We only use SocketPair in tests
+ // anyway.
+ //
+ // NOTE: This is purely due to the fact that the raw
+ // syscall does not serve as a boundary for the sanitizer.
+ var race int32
+ a, err := NewSocket(fds[0])
+ if err != nil {
+ syscall.Close(fds[0])
+ syscall.Close(fds[1])
+ return nil, nil, err
+ }
+ a.race = &race
+ b, err := NewSocket(fds[1])
+ if err != nil {
+ a.Close()
+ syscall.Close(fds[1])
+ return nil, nil, err
+ }
+ b.race = &race
+ return a, b, nil
+}
+
+// Connect connects to a server.
+func Connect(addr string, packet bool) (*Socket, error) {
+ fd, err := socket(packet)
+ if err != nil {
+ return nil, err
+ }
+
+ // Connect the socket.
+ usa := &syscall.SockaddrUnix{Name: addr}
+ if err := syscall.Connect(fd, usa); err != nil {
+ syscall.Close(fd)
+ return nil, err
+ }
+
+ return NewSocket(fd)
+}
+
+// ControlMessage wraps around a byte array and provides functions for parsing
+// as a Unix Domain Socket control message.
+type ControlMessage []byte
+
+// EnableFDs enables receiving FDs via control message.
+//
+// This guarantees only a MINIMUM number of FDs received. You may receive MORE
+// than this due to the way FDs are packed. To be specific, the number of
+// receivable buffers will be rounded up to the nearest even number.
+//
+// This must be called prior to ReadVec if you want to receive FDs.
+func (c *ControlMessage) EnableFDs(count int) {
+ *c = make([]byte, syscall.CmsgSpace(count*4))
+}
+
+// ExtractFDs returns the list of FDs in the control message.
+//
+// Either this or CloseFDs should be used after EnableFDs.
+func (c *ControlMessage) ExtractFDs() ([]int, error) {
+ msgs, err := syscall.ParseSocketControlMessage(*c)
+ if err != nil {
+ return nil, err
+ }
+ var fds []int
+ for _, msg := range msgs {
+ thisFds, err := syscall.ParseUnixRights(&msg)
+ if err != nil {
+ // Different control message.
+ return nil, err
+ }
+ for _, fd := range thisFds {
+ if fd >= 0 {
+ fds = append(fds, fd)
+ }
+ }
+ }
+ return fds, nil
+}
+
+// CloseFDs closes the list of FDs in the control message.
+//
+// Either this or ExtractFDs should be used after EnableFDs.
+func (c *ControlMessage) CloseFDs() {
+ fds, _ := c.ExtractFDs()
+ for _, fd := range fds {
+ if fd >= 0 {
+ syscall.Close(fd)
+ }
+ }
+}
+
+// PackFDs packs the given list of FDs in the control message.
+//
+// This must be used prior to WriteVec.
+func (c *ControlMessage) PackFDs(fds ...int) {
+ *c = ControlMessage(syscall.UnixRights(fds...))
+}
+
+// UnpackFDs clears the control message.
+func (c *ControlMessage) UnpackFDs() {
+ *c = nil
+}
+
+// SocketWriter wraps an individual send operation.
+//
+// The normal entrypoint is WriteVec.
+type SocketWriter struct {
+ socket *Socket
+ to []byte
+ blocking bool
+ race *int32
+
+ ControlMessage
+}
+
+// Writer returns a writer for this socket.
+func (s *Socket) Writer(blocking bool) SocketWriter {
+ return SocketWriter{socket: s, blocking: blocking, race: s.race}
+}
+
+// Write implements io.Writer.Write.
+func (s *Socket) Write(p []byte) (int, error) {
+ r := s.Writer(true)
+ return r.WriteVec([][]byte{p})
+}
+
+// GetSockOpt gets the given socket option.
+func (s *Socket) GetSockOpt(level int, name int, b []byte) (uint32, error) {
+ fd, ok := s.enterFD()
+ if !ok {
+ return 0, syscall.EBADF
+ }
+ defer s.gate.Leave()
+
+ return getsockopt(fd, level, name, b)
+}
+
+// SetSockOpt sets the given socket option.
+func (s *Socket) SetSockOpt(level, name int, b []byte) error {
+ fd, ok := s.enterFD()
+ if !ok {
+ return syscall.EBADF
+ }
+ defer s.gate.Leave()
+
+ return setsockopt(fd, level, name, b)
+}
+
+// GetSockName returns the socket name.
+func (s *Socket) GetSockName() ([]byte, error) {
+ fd, ok := s.enterFD()
+ if !ok {
+ return nil, syscall.EBADF
+ }
+ defer s.gate.Leave()
+
+ var buf []byte
+ l := syscall.SizeofSockaddrAny
+
+ for {
+ // If the buffer is not large enough, allocate a new one with the hint.
+ buf = make([]byte, l)
+ l, err := getsockname(fd, buf)
+ if err != nil {
+ return nil, err
+ }
+
+ if l <= uint32(len(buf)) {
+ return buf[:l], nil
+ }
+ }
+}
+
+// GetPeerName returns the peer name.
+func (s *Socket) GetPeerName() ([]byte, error) {
+ fd, ok := s.enterFD()
+ if !ok {
+ return nil, syscall.EBADF
+ }
+ defer s.gate.Leave()
+
+ var buf []byte
+ l := syscall.SizeofSockaddrAny
+
+ for {
+ // See above.
+ buf = make([]byte, l)
+ l, err := getpeername(fd, buf)
+ if err != nil {
+ return nil, err
+ }
+
+ if l <= uint32(len(buf)) {
+ return buf[:l], nil
+ }
+ }
+}
+
+// GetPeerCred returns the peer's unix credentials.
+func (s *Socket) GetPeerCred() (*syscall.Ucred, error) {
+ fd, ok := s.enterFD()
+ if !ok {
+ return nil, syscall.EBADF
+ }
+ defer s.gate.Leave()
+
+ return syscall.GetsockoptUcred(fd, syscall.SOL_SOCKET, syscall.SO_PEERCRED)
+}
+
+// SocketReader wraps an individual receive operation.
+//
+// This may be used for doing vectorized reads and/or sending additional
+// control messages (e.g. FDs). The normal entrypoint is ReadVec.
+//
+// One of ExtractFDs or DisposeFDs must be called if EnableFDs is used.
+type SocketReader struct {
+ socket *Socket
+ source []byte
+ blocking bool
+ race *int32
+
+ ControlMessage
+}
+
+// Reader returns a reader for this socket.
+func (s *Socket) Reader(blocking bool) SocketReader {
+ return SocketReader{socket: s, blocking: blocking, race: s.race}
+}
+
+// Read implements io.Reader.Read.
+func (s *Socket) Read(p []byte) (int, error) {
+ r := s.Reader(true)
+ return r.ReadVec([][]byte{p})
+}
+
+func (s *Socket) shutdown(fd int) error {
+ // Shutdown the socket to cancel any pending accepts.
+ return syscall.Shutdown(fd, syscall.SHUT_RDWR)
+}
+
+// Shutdown closes the socket for read and write.
+func (s *Socket) Shutdown() error {
+ fd, ok := s.enterFD()
+ if !ok {
+ return syscall.EBADF
+ }
+ defer s.gate.Leave()
+
+ return s.shutdown(fd)
+}
+
+// ServerSocket is a bound unix domain socket.
+type ServerSocket struct {
+ socket *Socket
+}
+
+// NewServerSocket returns a socket from an existing FD.
+func NewServerSocket(fd int) (*ServerSocket, error) {
+ s, err := NewSocket(fd)
+ if err != nil {
+ return nil, err
+ }
+ return &ServerSocket{socket: s}, nil
+}
+
+// Bind creates and binds a new socket.
+func Bind(addr string, packet bool) (*ServerSocket, error) {
+ fd, err := socket(packet)
+ if err != nil {
+ return nil, err
+ }
+
+ // Do the bind.
+ usa := &syscall.SockaddrUnix{Name: addr}
+ if err := syscall.Bind(fd, usa); err != nil {
+ syscall.Close(fd)
+ return nil, err
+ }
+
+ return NewServerSocket(fd)
+}
+
+// BindAndListen creates, binds and listens on a new socket.
+func BindAndListen(addr string, packet bool) (*ServerSocket, error) {
+ s, err := Bind(addr, packet)
+ if err != nil {
+ return nil, err
+ }
+
+ // Start listening.
+ if err := s.Listen(); err != nil {
+ s.Close()
+ return nil, err
+ }
+
+ return s, nil
+}
+
+// Listen starts listening on the socket.
+func (s *ServerSocket) Listen() error {
+ fd, ok := s.socket.enterFD()
+ if !ok {
+ return syscall.EBADF
+ }
+ defer s.socket.gate.Leave()
+
+ return syscall.Listen(fd, backlog)
+}
+
+// Accept accepts a new connection.
+//
+// This is always blocking.
+//
+// Preconditions:
+// * ServerSocket is listening (Listen called).
+func (s *ServerSocket) Accept() (*Socket, error) {
+ fd, ok := s.socket.enterFD()
+ if !ok {
+ return nil, syscall.EBADF
+ }
+ defer s.socket.gate.Leave()
+
+ for {
+ nfd, _, err := syscall.Accept(fd)
+ switch err {
+ case nil:
+ return NewSocket(nfd)
+ case syscall.EAGAIN:
+ err = s.socket.wait(false)
+ if err == errClosing {
+ err = syscall.EBADF
+ }
+ }
+ if err != nil {
+ return nil, err
+ }
+ }
+}
+
+// Close closes the server socket.
+//
+// This must only be called once.
+func (s *ServerSocket) Close() error {
+ return s.socket.Close()
+}
+
+// FD returns the socket's file descriptor.
+//
+// See Socket.FD.
+func (s *ServerSocket) FD() int {
+ return s.socket.FD()
+}
+
+// Release releases ownership of the socket's file descriptor.
+//
+// See Socket.Release.
+func (s *ServerSocket) Release() (int, error) {
+ return s.socket.Release()
+}
diff --git a/pkg/unet/unet_test.go b/pkg/unet/unet_test.go
new file mode 100644
index 000000000..6c546825f
--- /dev/null
+++ b/pkg/unet/unet_test.go
@@ -0,0 +1,693 @@
+// Copyright 2018 Google Inc.
+//
+// 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 unet
+
+import (
+ "io/ioutil"
+ "os"
+ "path/filepath"
+ "reflect"
+ "sync"
+ "syscall"
+ "testing"
+ "time"
+)
+
+func randomFilename() (string, error) {
+ // Return a randomly generated file in the test dir.
+ f, err := ioutil.TempFile("", "unet-test")
+ if err != nil {
+ return "", err
+ }
+ file := f.Name()
+ os.Remove(file)
+ f.Close()
+
+ cwd, err := os.Getwd()
+ if err != nil {
+ return "", err
+ }
+
+ // NOTE: We try to use relative path if possible. This is
+ // to help conforming to the unix path length limit.
+ if rel, err := filepath.Rel(cwd, file); err == nil {
+ return rel, nil
+ }
+
+ return file, nil
+}
+
+func TestConnectFailure(t *testing.T) {
+ name, err := randomFilename()
+ if err != nil {
+ t.Fatalf("unable to generate file, got err %v expected nil", err)
+ }
+
+ if _, err := Connect(name, false); err == nil {
+ t.Fatalf("connect was successful, expected err")
+ }
+}
+
+func TestBindFailure(t *testing.T) {
+ name, err := randomFilename()
+ if err != nil {
+ t.Fatalf("unable to generate file, got err %v expected nil", err)
+ }
+
+ ss, err := BindAndListen(name, false)
+ if err != nil {
+ t.Fatalf("first bind failed, got err %v expected nil", err)
+ }
+ defer ss.Close()
+
+ if _, err = BindAndListen(name, false); err == nil {
+ t.Fatalf("second bind succeeded, expected non-nil err")
+ }
+}
+
+func TestMultipleAccept(t *testing.T) {
+ name, err := randomFilename()
+ if err != nil {
+ t.Fatalf("unable to generate file, got err %v expected nil", err)
+ }
+
+ ss, err := BindAndListen(name, false)
+ if err != nil {
+ t.Fatalf("first bind failed, got err %v expected nil", err)
+ }
+ defer ss.Close()
+
+ // Connect backlog times asynchronously.
+ var wg sync.WaitGroup
+ defer wg.Wait()
+ for i := 0; i < backlog; i++ {
+ wg.Add(1)
+ go func() {
+ defer wg.Done()
+ s, err := Connect(name, false)
+ if err != nil {
+ t.Fatalf("connect failed, got err %v expected nil", err)
+ }
+ s.Close()
+ }()
+ }
+
+ // Accept backlog times.
+ for i := 0; i < backlog; i++ {
+ s, err := ss.Accept()
+ if err != nil {
+ t.Errorf("accept failed, got err %v expected nil", err)
+ continue
+ }
+ s.Close()
+ }
+}
+
+func TestServerClose(t *testing.T) {
+ name, err := randomFilename()
+ if err != nil {
+ t.Fatalf("unable to generate file, got err %v expected nil", err)
+ }
+
+ ss, err := BindAndListen(name, false)
+ if err != nil {
+ t.Fatalf("first bind failed, got err %v expected nil", err)
+ }
+
+ // Make sure the first close succeeds.
+ if err := ss.Close(); err != nil {
+ t.Fatalf("first close failed, got err %v expected nil", err)
+ }
+
+ // The second one should fail.
+ if err := ss.Close(); err == nil {
+ t.Fatalf("second close succeeded, expected non-nil err")
+ }
+}
+
+func socketPair(t *testing.T, packet bool) (*Socket, *Socket) {
+ name, err := randomFilename()
+ if err != nil {
+ t.Fatalf("unable to generate file, got err %v expected nil", err)
+ }
+
+ // Bind a server.
+ ss, err := BindAndListen(name, packet)
+ if err != nil {
+ t.Fatalf("error binding, got %v expected nil", err)
+ }
+ defer ss.Close()
+
+ // Accept a client.
+ acceptSocket := make(chan *Socket)
+ acceptErr := make(chan error)
+ go func() {
+ server, err := ss.Accept()
+ if err != nil {
+ acceptErr <- err
+ }
+ acceptSocket <- server
+ }()
+
+ // Connect the client.
+ client, err := Connect(name, packet)
+ if err != nil {
+ t.Fatalf("error connecting, got %v expected nil", err)
+ }
+
+ // Grab the server handle.
+ select {
+ case server := <-acceptSocket:
+ return server, client
+ case err := <-acceptErr:
+ t.Fatalf("accept error: %v", err)
+ }
+ panic("unreachable")
+}
+
+func TestSendRecv(t *testing.T) {
+ server, client := socketPair(t, false)
+ defer server.Close()
+ defer client.Close()
+
+ // Write on the client.
+ w := client.Writer(true)
+ if n, err := w.WriteVec([][]byte{{'a'}}); n != 1 || err != nil {
+ t.Fatalf("for client write, got n=%d err=%v, expected n=1 err=nil", n, err)
+ }
+
+ // Read on the server.
+ b := [][]byte{{'b'}}
+ r := server.Reader(true)
+ if n, err := r.ReadVec(b); n != 1 || err != nil {
+ t.Fatalf("for server read, got n=%d err=%v, expected n=1 err=nil", n, err)
+ }
+ if b[0][0] != 'a' {
+ t.Fatalf("got bad read data, got %c, expected a", b[0][0])
+ }
+}
+
+// TestSymmetric exists to assert that the two sockets received from socketPair
+// are interchangeable. They should be, this just provides a basic sanity check
+// by running TestSendRecv "backwards".
+func TestSymmetric(t *testing.T) {
+ server, client := socketPair(t, false)
+ defer server.Close()
+ defer client.Close()
+
+ // Write on the server.
+ w := server.Writer(true)
+ if n, err := w.WriteVec([][]byte{{'a'}}); n != 1 || err != nil {
+ t.Fatalf("for server write, got n=%d err=%v, expected n=1 err=nil", n, err)
+ }
+
+ // Read on the client.
+ b := [][]byte{{'b'}}
+ r := client.Reader(true)
+ if n, err := r.ReadVec(b); n != 1 || err != nil {
+ t.Fatalf("for client read, got n=%d err=%v, expected n=1 err=nil", n, err)
+ }
+ if b[0][0] != 'a' {
+ t.Fatalf("got bad read data, got %c, expected a", b[0][0])
+ }
+}
+
+func TestPacket(t *testing.T) {
+ server, client := socketPair(t, true)
+ defer server.Close()
+ defer client.Close()
+
+ // Write on the client.
+ w := client.Writer(true)
+ if n, err := w.WriteVec([][]byte{{'a'}}); n != 1 || err != nil {
+ t.Fatalf("for client write, got n=%d err=%v, expected n=1 err=nil", n, err)
+ }
+
+ // Write on the client again.
+ w = client.Writer(true)
+ if n, err := w.WriteVec([][]byte{{'a'}}); n != 1 || err != nil {
+ t.Fatalf("for client write, got n=%d err=%v, expected n=1 err=nil", n, err)
+ }
+
+ // Read on the server.
+ //
+ // This should only get back a single byte, despite the buffer
+ // being size two. This is because it's a _packet_ buffer.
+ b := [][]byte{{'b', 'b'}}
+ r := server.Reader(true)
+ if n, err := r.ReadVec(b); n != 1 || err != nil {
+ t.Fatalf("for server read, got n=%d err=%v, expected n=1 err=nil", n, err)
+ }
+ if b[0][0] != 'a' {
+ t.Fatalf("got bad read data, got %c, expected a", b[0][0])
+ }
+
+ // Do it again.
+ r = server.Reader(true)
+ if n, err := r.ReadVec(b); n != 1 || err != nil {
+ t.Fatalf("for server read, got n=%d err=%v, expected n=1 err=nil", n, err)
+ }
+ if b[0][0] != 'a' {
+ t.Fatalf("got bad read data, got %c, expected a", b[0][0])
+ }
+}
+
+func TestClose(t *testing.T) {
+ server, client := socketPair(t, false)
+ defer server.Close()
+
+ // Make sure the first close succeeds.
+ if err := client.Close(); err != nil {
+ t.Fatalf("first close failed, got err %v expected nil", err)
+ }
+
+ // The second one should fail.
+ if err := client.Close(); err == nil {
+ t.Fatalf("second close succeeded, expected non-nil err")
+ }
+}
+
+func TestNonBlockingSend(t *testing.T) {
+ server, client := socketPair(t, false)
+ defer server.Close()
+ defer client.Close()
+
+ // Try up to 1000 writes, of 1000 bytes.
+ blockCount := 0
+ for i := 0; i < 1000; i++ {
+ w := client.Writer(false)
+ if n, err := w.WriteVec([][]byte{make([]byte, 1000)}); n != 1000 || err != nil {
+ if err == syscall.EWOULDBLOCK || err == syscall.EAGAIN {
+ // We're good. That's what we wanted.
+ blockCount++
+ } else {
+ t.Fatalf("for client write, got n=%d err=%v, expected n=1000 err=nil", n, err)
+ }
+ }
+ }
+
+ if blockCount == 1000 {
+ // Shouldn't have _always_ blocked.
+ t.Fatalf("socket always blocked!")
+ } else if blockCount == 0 {
+ // Should have started blocking eventually.
+ t.Fatalf("socket never blocked!")
+ }
+}
+
+func TestNonBlockingRecv(t *testing.T) {
+ server, client := socketPair(t, false)
+ defer server.Close()
+ defer client.Close()
+
+ b := [][]byte{{'b'}}
+ r := client.Reader(false)
+
+ // Expected to block immediately.
+ _, err := r.ReadVec(b)
+ if err != syscall.EWOULDBLOCK && err != syscall.EAGAIN {
+ t.Fatalf("read didn't block, got err %v expected blocking err", err)
+ }
+
+ // Put some data in the pipe.
+ w := server.Writer(false)
+ if n, err := w.WriteVec(b); n != 1 || err != nil {
+ t.Fatalf("write failed with n=%d err=%v, expected n=1 err=nil", n, err)
+ }
+
+ // Expect it not to block.
+ if n, err := r.ReadVec(b); n != 1 || err != nil {
+ t.Fatalf("read failed with n=%d err=%v, expected n=1 err=nil", n, err)
+ }
+
+ // Expect it to return a block error again.
+ r = client.Reader(false)
+ _, err = r.ReadVec(b)
+ if err != syscall.EWOULDBLOCK && err != syscall.EAGAIN {
+ t.Fatalf("read didn't block, got err %v expected blocking err", err)
+ }
+}
+
+func TestRecvVectors(t *testing.T) {
+ server, client := socketPair(t, false)
+ defer server.Close()
+ defer client.Close()
+
+ // Write on the client.
+ w := client.Writer(true)
+ if n, err := w.WriteVec([][]byte{{'a', 'b'}}); n != 2 || err != nil {
+ t.Fatalf("for client write, got n=%d err=%v, expected n=2 err=nil", n, err)
+ }
+
+ // Read on the server.
+ b := [][]byte{{'c'}, {'c'}}
+ r := server.Reader(true)
+ if n, err := r.ReadVec(b); n != 2 || err != nil {
+ t.Fatalf("for server read, got n=%d err=%v, expected n=2 err=nil", n, err)
+ }
+ if b[0][0] != 'a' || b[1][0] != 'b' {
+ t.Fatalf("got bad read data, got %c,%c, expected a,b", b[0][0], b[1][0])
+ }
+}
+
+func TestSendVectors(t *testing.T) {
+ server, client := socketPair(t, false)
+ defer server.Close()
+ defer client.Close()
+
+ // Write on the client.
+ w := client.Writer(true)
+ if n, err := w.WriteVec([][]byte{{'a'}, {'b'}}); n != 2 || err != nil {
+ t.Fatalf("for client write, got n=%d err=%v, expected n=2 err=nil", n, err)
+ }
+
+ // Read on the server.
+ b := [][]byte{{'c', 'c'}}
+ r := server.Reader(true)
+ if n, err := r.ReadVec(b); n != 2 || err != nil {
+ t.Fatalf("for server read, got n=%d err=%v, expected n=2 err=nil", n, err)
+ }
+ if b[0][0] != 'a' || b[0][1] != 'b' {
+ t.Fatalf("got bad read data, got %c,%c, expected a,b", b[0][0], b[0][1])
+ }
+}
+
+func TestSendFDsNotEnabled(t *testing.T) {
+ server, client := socketPair(t, false)
+ defer server.Close()
+ defer client.Close()
+
+ // Write on the server.
+ w := server.Writer(true)
+ w.PackFDs(0, 1, 2)
+ if n, err := w.WriteVec([][]byte{{'a'}}); n != 1 || err != nil {
+ t.Fatalf("for server write, got n=%d err=%v, expected n=1 err=nil", n, err)
+ }
+
+ // Read on the client, without enabling FDs.
+ b := [][]byte{{'b'}}
+ r := client.Reader(true)
+ if n, err := r.ReadVec(b); n != 1 || err != nil {
+ t.Fatalf("for client read, got n=%d err=%v, expected n=1 err=nil", n, err)
+ }
+ if b[0][0] != 'a' {
+ t.Fatalf("got bad read data, got %c, expected a", b[0][0])
+ }
+
+ // Make sure the FDs are not received.
+ fds, err := r.ExtractFDs()
+ if len(fds) != 0 || err != nil {
+ t.Fatalf("got fds=%v err=%v, expected len(fds)=0 err=nil", fds, err)
+ }
+}
+
+func sendFDs(t *testing.T, s *Socket, fds []int) {
+ w := s.Writer(true)
+ w.PackFDs(fds...)
+ if n, err := w.WriteVec([][]byte{{'a'}}); n != 1 || err != nil {
+ t.Fatalf("for write, got n=%d err=%v, expected n=1 err=nil", n, err)
+ }
+}
+
+func recvFDs(t *testing.T, s *Socket, enableSize int, origFDs []int) {
+ expected := len(origFDs)
+
+ // Count the number of FDs.
+ preEntries, err := ioutil.ReadDir("/proc/self/fd")
+ if err != nil {
+ t.Fatalf("can't readdir, got err %v expected nil", err)
+ }
+
+ // Read on the client.
+ b := [][]byte{{'b'}}
+ r := s.Reader(true)
+ if enableSize >= 0 {
+ r.EnableFDs(enableSize)
+ }
+ if n, err := r.ReadVec(b); n != 1 || err != nil {
+ t.Fatalf("for client read, got n=%d err=%v, expected n=1 err=nil", n, err)
+ }
+ if b[0][0] != 'a' {
+ t.Fatalf("got bad read data, got %c, expected a", b[0][0])
+ }
+
+ // Count the new number of FDs.
+ postEntries, err := ioutil.ReadDir("/proc/self/fd")
+ if err != nil {
+ t.Fatalf("can't readdir, got err %v expected nil", err)
+ }
+ if len(preEntries)+expected != len(postEntries) {
+ t.Errorf("process fd count isn't right, expected %d got %d", len(preEntries)+expected, len(postEntries))
+ }
+
+ // Make sure the FDs are there.
+ fds, err := r.ExtractFDs()
+ if len(fds) != expected || err != nil {
+ t.Fatalf("got fds=%v err=%v, expected len(fds)=%d err=nil", fds, err, expected)
+ }
+
+ // Make sure they are different from the originals.
+ for i := 0; i < len(fds); i++ {
+ if fds[i] == origFDs[i] {
+ t.Errorf("got original fd for index %d, expected different", i)
+ }
+ }
+
+ // Make sure they can be accessed as expected.
+ for i := 0; i < len(fds); i++ {
+ var st syscall.Stat_t
+ if err := syscall.Fstat(fds[i], &st); err != nil {
+ t.Errorf("fds[%d] can't be stated, got err %v expected nil", i, err)
+ }
+ }
+
+ // Close them off.
+ r.CloseFDs()
+
+ // Make sure the count is back to normal.
+ finalEntries, err := ioutil.ReadDir("/proc/self/fd")
+ if err != nil {
+ t.Fatalf("can't readdir, got err %v expected nil", err)
+ }
+ if len(finalEntries) != len(preEntries) {
+ t.Errorf("process fd count isn't right, expected %d got %d", len(preEntries), len(finalEntries))
+ }
+}
+
+func TestFDsSingle(t *testing.T) {
+ server, client := socketPair(t, false)
+ defer server.Close()
+ defer client.Close()
+
+ sendFDs(t, server, []int{0})
+ recvFDs(t, client, 1, []int{0})
+}
+
+func TestFDsMultiple(t *testing.T) {
+ server, client := socketPair(t, false)
+ defer server.Close()
+ defer client.Close()
+
+ // Basic case, multiple FDs.
+ sendFDs(t, server, []int{0, 1, 2})
+ recvFDs(t, client, 3, []int{0, 1, 2})
+}
+
+// See TestSymmetric above.
+func TestFDsSymmetric(t *testing.T) {
+ server, client := socketPair(t, false)
+ defer server.Close()
+ defer client.Close()
+
+ sendFDs(t, server, []int{0, 1, 2})
+ recvFDs(t, client, 3, []int{0, 1, 2})
+}
+
+func TestFDsReceiveLargeBuffer(t *testing.T) {
+ server, client := socketPair(t, false)
+ defer server.Close()
+ defer client.Close()
+
+ sendFDs(t, server, []int{0})
+ recvFDs(t, client, 3, []int{0})
+}
+
+func TestFDsReceiveSmallBuffer(t *testing.T) {
+ server, client := socketPair(t, false)
+ defer server.Close()
+ defer client.Close()
+
+ sendFDs(t, server, []int{0, 1, 2})
+
+ // Per the spec, we may still receive more than the buffer. In fact,
+ // it'll be rounded up and we can receive two with a size one buffer.
+ recvFDs(t, client, 1, []int{0, 1})
+}
+
+func TestFDsReceiveNotEnabled(t *testing.T) {
+ server, client := socketPair(t, false)
+ defer server.Close()
+ defer client.Close()
+
+ sendFDs(t, server, []int{0})
+ recvFDs(t, client, -1, []int{})
+}
+
+func TestFDsReceiveSizeZero(t *testing.T) {
+ server, client := socketPair(t, false)
+ defer server.Close()
+ defer client.Close()
+
+ sendFDs(t, server, []int{0})
+ recvFDs(t, client, 0, []int{})
+}
+
+func TestGetPeerCred(t *testing.T) {
+ server, client := socketPair(t, false)
+ defer server.Close()
+ defer client.Close()
+
+ want := &syscall.Ucred{
+ Pid: int32(os.Getpid()),
+ Uid: uint32(os.Getuid()),
+ Gid: uint32(os.Getgid()),
+ }
+
+ if got, err := client.GetPeerCred(); err != nil || !reflect.DeepEqual(got, want) {
+ t.Errorf("got GetPeerCred() = %v, %v, want = %+v, %+v", got, err, want, nil)
+ }
+}
+
+func newClosedSocket() (*Socket, error) {
+ fd, err := syscall.Socket(syscall.AF_UNIX, syscall.SOCK_STREAM, 0)
+ if err != nil {
+ return nil, err
+ }
+
+ s, err := NewSocket(fd)
+ if err != nil {
+ syscall.Close(fd)
+ return nil, err
+ }
+
+ return s, s.Close()
+}
+
+func TestGetPeerCredFailure(t *testing.T) {
+ s, err := newClosedSocket()
+ if err != nil {
+ t.Fatalf("newClosedSocket got error %v want nil", err)
+ }
+
+ want := "bad file descriptor"
+ if _, err := s.GetPeerCred(); err == nil || err.Error() != want {
+ t.Errorf("got s.GetPeerCred() = %v, want = %s", err, want)
+ }
+}
+
+func TestAcceptClosed(t *testing.T) {
+ name, err := randomFilename()
+ if err != nil {
+ t.Fatalf("unable to generate file, got err %v expected nil", err)
+ }
+
+ ss, err := BindAndListen(name, false)
+ if err != nil {
+ t.Fatalf("bind failed, got err %v expected nil", err)
+ }
+
+ if err := ss.Close(); err != nil {
+ t.Fatalf("close failed, got err %v expected nil", err)
+ }
+
+ if _, err := ss.Accept(); err == nil {
+ t.Errorf("accept on closed SocketServer, got err %v, want != nil", err)
+ }
+}
+
+func TestCloseAfterAcceptStart(t *testing.T) {
+ name, err := randomFilename()
+ if err != nil {
+ t.Fatalf("unable to generate file, got err %v expected nil", err)
+ }
+
+ ss, err := BindAndListen(name, false)
+ if err != nil {
+ t.Fatalf("bind failed, got err %v expected nil", err)
+ }
+
+ wg := sync.WaitGroup{}
+ wg.Add(1)
+ go func() {
+ time.Sleep(50 * time.Millisecond)
+ if err := ss.Close(); err != nil {
+ t.Fatalf("close failed, got err %v expected nil", err)
+ }
+ wg.Done()
+ }()
+
+ if _, err := ss.Accept(); err == nil {
+ t.Errorf("accept on closed SocketServer, got err %v, want != nil", err)
+ }
+
+ wg.Wait()
+}
+
+func TestReleaseAfterAcceptStart(t *testing.T) {
+ name, err := randomFilename()
+ if err != nil {
+ t.Fatalf("unable to generate file, got err %v expected nil", err)
+ }
+
+ ss, err := BindAndListen(name, false)
+ if err != nil {
+ t.Fatalf("bind failed, got err %v expected nil", err)
+ }
+
+ wg := sync.WaitGroup{}
+ wg.Add(1)
+ go func() {
+ time.Sleep(50 * time.Millisecond)
+ fd, err := ss.Release()
+ if err != nil {
+ t.Fatalf("Release failed, got err %v expected nil", err)
+ }
+ syscall.Close(fd)
+ wg.Done()
+ }()
+
+ if _, err := ss.Accept(); err == nil {
+ t.Errorf("accept on closed SocketServer, got err %v, want != nil", err)
+ }
+
+ wg.Wait()
+}
+
+func TestControlMessage(t *testing.T) {
+ for i := 0; i <= 10; i++ {
+ var want []int
+ for j := 0; j < i; j++ {
+ want = append(want, i+j+1)
+ }
+
+ var cm ControlMessage
+ cm.EnableFDs(i)
+ cm.PackFDs(want...)
+ got, err := cm.ExtractFDs()
+ if err != nil || !reflect.DeepEqual(got, want) {
+ t.Errorf("got cm.ExtractFDs() = %v, %v, want = %v, %v", got, err, want, nil)
+ }
+ }
+}
diff --git a/pkg/unet/unet_unsafe.go b/pkg/unet/unet_unsafe.go
new file mode 100644
index 000000000..fa15cf744
--- /dev/null
+++ b/pkg/unet/unet_unsafe.go
@@ -0,0 +1,287 @@
+// Copyright 2018 Google Inc.
+//
+// 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 unet
+
+import (
+ "io"
+ "math"
+ "sync/atomic"
+ "syscall"
+ "unsafe"
+
+ "gvisor.googlesource.com/gvisor/pkg/abi/linux"
+)
+
+// wait blocks until the socket FD is ready for reading or writing, depending
+// on the value of write.
+//
+// Returns errClosing if the Socket is in the process of closing.
+func (s *Socket) wait(write bool) error {
+ for {
+ // Checking the FD on each loop is not strictly necessary, it
+ // just avoids an extra poll call.
+ fd := atomic.LoadInt32(&s.fd)
+ if fd < 0 {
+ return errClosing
+ }
+
+ events := []linux.PollFD{
+ {
+ // The actual socket FD.
+ FD: fd,
+ Events: linux.POLLIN,
+ },
+ {
+ // The eventfd, signaled when we are closing.
+ FD: int32(s.efd),
+ Events: linux.POLLIN,
+ },
+ }
+ if write {
+ events[0].Events = linux.POLLOUT
+ }
+
+ _, _, e := syscall.Syscall(syscall.SYS_POLL, uintptr(unsafe.Pointer(&events[0])), 2, uintptr(math.MaxUint64))
+ if e == syscall.EINTR {
+ continue
+ }
+ if e != 0 {
+ return e
+ }
+
+ if events[1].REvents&linux.POLLIN == linux.POLLIN {
+ // eventfd signaled, we're closing.
+ return errClosing
+ }
+
+ return nil
+ }
+}
+
+// buildIovec builds an iovec slice from the given []byte slice.
+//
+// iovecs is used as an initial slice, to avoid excessive allocations.
+func buildIovec(bufs [][]byte, iovecs []syscall.Iovec) ([]syscall.Iovec, int) {
+ var length int
+ for i := range bufs {
+ if l := len(bufs[i]); l > 0 {
+ iovecs = append(iovecs, syscall.Iovec{
+ Base: &bufs[i][0],
+ Len: uint64(l),
+ })
+ length += l
+ }
+ }
+ return iovecs, length
+}
+
+// ReadVec implements vecio.Reader.ReadVec.
+//
+// This function is not guaranteed to read all available data, it
+// returns as soon as a single recvmsg call succeeds.
+func (r *SocketReader) ReadVec(bufs [][]byte) (int, error) {
+ iovecs, length := buildIovec(bufs, make([]syscall.Iovec, 0, 2))
+
+ var msg syscall.Msghdr
+ if len(r.source) != 0 {
+ msg.Name = &r.source[0]
+ msg.Namelen = uint32(len(r.source))
+ }
+
+ if len(r.ControlMessage) != 0 {
+ msg.Control = &r.ControlMessage[0]
+ msg.Controllen = uint64(len(r.ControlMessage))
+ }
+
+ if len(iovecs) != 0 {
+ msg.Iov = &iovecs[0]
+ msg.Iovlen = uint64(len(iovecs))
+ }
+
+ // n is the bytes received.
+ var n uintptr
+
+ fd, ok := r.socket.enterFD()
+ if !ok {
+ return 0, syscall.EBADF
+ }
+ // Leave on returns below.
+ for {
+ var e syscall.Errno
+
+ // Try a non-blocking recv first, so we don't give up the go runtime M.
+ n, _, e = syscall.RawSyscall(syscall.SYS_RECVMSG, uintptr(fd), uintptr(unsafe.Pointer(&msg)), syscall.MSG_DONTWAIT|syscall.MSG_TRUNC)
+ if e == 0 {
+ break
+ }
+ if e == syscall.EINTR {
+ continue
+ }
+ if !r.blocking {
+ r.socket.gate.Leave()
+ return 0, e
+ }
+ if e != syscall.EAGAIN && e != syscall.EWOULDBLOCK {
+ r.socket.gate.Leave()
+ return 0, e
+ }
+
+ // Wait for the socket to become readable.
+ err := r.socket.wait(false)
+ if err == errClosing {
+ err = syscall.EBADF
+ }
+ if err != nil {
+ r.socket.gate.Leave()
+ return 0, err
+ }
+ }
+
+ r.socket.gate.Leave()
+
+ if msg.Controllen < uint64(len(r.ControlMessage)) {
+ r.ControlMessage = r.ControlMessage[:msg.Controllen]
+ }
+
+ if msg.Namelen < uint32(len(r.source)) {
+ r.source = r.source[:msg.Namelen]
+ }
+
+ // All unet sockets are SOCK_STREAM or SOCK_SEQPACKET, both of which
+ // indicate that the other end is closed by returning a 0-length read
+ // with no error.
+ if n == 0 {
+ return 0, io.EOF
+ }
+
+ if r.race != nil {
+ // See comments on Socket.race.
+ atomic.AddInt32(r.race, 1)
+ }
+
+ if int(n) > length {
+ return length, errMessageTruncated
+ }
+
+ return int(n), nil
+}
+
+// WriteVec implements vecio.Writer.WriteVec.
+//
+// This function is not guaranteed to send all data, it returns
+// as soon as a single sendmsg call succeeds.
+func (w *SocketWriter) WriteVec(bufs [][]byte) (int, error) {
+ iovecs, _ := buildIovec(bufs, make([]syscall.Iovec, 0, 2))
+
+ if w.race != nil {
+ // See comments on Socket.race.
+ atomic.AddInt32(w.race, 1)
+ }
+
+ var msg syscall.Msghdr
+ if len(w.to) != 0 {
+ msg.Name = &w.to[0]
+ msg.Namelen = uint32(len(w.to))
+ }
+
+ if len(w.ControlMessage) != 0 {
+ msg.Control = &w.ControlMessage[0]
+ msg.Controllen = uint64(len(w.ControlMessage))
+ }
+
+ if len(iovecs) > 0 {
+ msg.Iov = &iovecs[0]
+ msg.Iovlen = uint64(len(iovecs))
+ }
+
+ fd, ok := w.socket.enterFD()
+ if !ok {
+ return 0, syscall.EBADF
+ }
+ // Leave on returns below.
+ for {
+ // Try a non-blocking send first, so we don't give up the go runtime M.
+ n, _, e := syscall.RawSyscall(syscall.SYS_SENDMSG, uintptr(fd), uintptr(unsafe.Pointer(&msg)), syscall.MSG_DONTWAIT|syscall.MSG_NOSIGNAL)
+ if e == 0 {
+ w.socket.gate.Leave()
+ return int(n), nil
+ }
+ if e == syscall.EINTR {
+ continue
+ }
+ if !w.blocking {
+ w.socket.gate.Leave()
+ return 0, e
+ }
+ if e != syscall.EAGAIN && e != syscall.EWOULDBLOCK {
+ w.socket.gate.Leave()
+ return 0, e
+ }
+
+ // Wait for the socket to become writeable.
+ err := w.socket.wait(true)
+ if err == errClosing {
+ err = syscall.EBADF
+ }
+ if err != nil {
+ w.socket.gate.Leave()
+ return 0, err
+ }
+ }
+ // Unreachable, no s.gate.Leave needed.
+}
+
+// getsockopt issues a getsockopt syscall.
+func getsockopt(fd int, level int, optname int, buf []byte) (uint32, error) {
+ l := uint32(len(buf))
+ _, _, e := syscall.RawSyscall6(syscall.SYS_GETSOCKOPT, uintptr(fd), uintptr(level), uintptr(optname), uintptr(unsafe.Pointer(&buf[0])), uintptr(unsafe.Pointer(&l)), 0)
+ if e != 0 {
+ return 0, e
+ }
+
+ return l, nil
+}
+
+// setsockopt issues a setsockopt syscall.
+func setsockopt(fd int, level int, optname int, buf []byte) error {
+ _, _, e := syscall.RawSyscall6(syscall.SYS_SETSOCKOPT, uintptr(fd), uintptr(level), uintptr(optname), uintptr(unsafe.Pointer(&buf[0])), uintptr(len(buf)), 0)
+ if e != 0 {
+ return e
+ }
+
+ return nil
+}
+
+// getsockname issues a getsockname syscall.
+func getsockname(fd int, buf []byte) (uint32, error) {
+ l := uint32(len(buf))
+ _, _, e := syscall.RawSyscall(syscall.SYS_GETSOCKNAME, uintptr(fd), uintptr(unsafe.Pointer(&buf[0])), uintptr(unsafe.Pointer(&l)))
+ if e != 0 {
+ return 0, e
+ }
+
+ return l, nil
+}
+
+// getpeername issues a getpeername syscall.
+func getpeername(fd int, buf []byte) (uint32, error) {
+ l := uint32(len(buf))
+ _, _, e := syscall.RawSyscall(syscall.SYS_GETPEERNAME, uintptr(fd), uintptr(unsafe.Pointer(&buf[0])), uintptr(unsafe.Pointer(&l)))
+ if e != 0 {
+ return 0, e
+ }
+
+ return l, nil
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-24 16:41:40 +0000