| // Copyright 2012 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| // +build linux dragonfly darwin freebsd netbsd openbsd |
| |
| package syscall_test |
| |
| import ( |
| "flag" |
| "fmt" |
| "io/ioutil" |
| "net" |
| "os" |
| "os/exec" |
| "runtime" |
| "syscall" |
| "testing" |
| "time" |
| ) |
| |
| // TestPassFD tests passing a file descriptor over a Unix socket. |
| // |
| // This test involved both a parent and child process. The parent |
| // process is invoked as a normal test, with "go test", which then |
| // runs the child process by running the current test binary with args |
| // "-test.run=^TestPassFD$" and an environment variable used to signal |
| // that the test should become the child process instead. |
| func TestPassFD(t *testing.T) { |
| if runtime.GOOS == "dragonfly" { |
| // TODO(jsing): Figure out why sendmsg is returning EINVAL. |
| t.Skip("Skipping test on dragonfly") |
| } |
| if os.Getenv("GO_WANT_HELPER_PROCESS") == "1" { |
| passFDChild() |
| return |
| } |
| |
| tempDir, err := ioutil.TempDir("", "TestPassFD") |
| if err != nil { |
| t.Fatal(err) |
| } |
| defer os.RemoveAll(tempDir) |
| |
| fds, err := syscall.Socketpair(syscall.AF_LOCAL, syscall.SOCK_STREAM, 0) |
| if err != nil { |
| t.Fatalf("Socketpair: %v", err) |
| } |
| defer syscall.Close(fds[0]) |
| defer syscall.Close(fds[1]) |
| writeFile := os.NewFile(uintptr(fds[0]), "child-writes") |
| readFile := os.NewFile(uintptr(fds[1]), "parent-reads") |
| defer writeFile.Close() |
| defer readFile.Close() |
| |
| cmd := exec.Command(os.Args[0], "-test.run=^TestPassFD$", "--", tempDir) |
| cmd.Env = []string{"GO_WANT_HELPER_PROCESS=1"} |
| cmd.ExtraFiles = []*os.File{writeFile} |
| |
| out, err := cmd.CombinedOutput() |
| if len(out) > 0 || err != nil { |
| t.Fatalf("child process: %q, %v", out, err) |
| } |
| |
| c, err := net.FileConn(readFile) |
| if err != nil { |
| t.Fatalf("FileConn: %v", err) |
| } |
| defer c.Close() |
| |
| uc, ok := c.(*net.UnixConn) |
| if !ok { |
| t.Fatalf("unexpected FileConn type; expected UnixConn, got %T", c) |
| } |
| |
| buf := make([]byte, 32) // expect 1 byte |
| oob := make([]byte, 32) // expect 24 bytes |
| closeUnix := time.AfterFunc(5*time.Second, func() { |
| t.Logf("timeout reading from unix socket") |
| uc.Close() |
| }) |
| _, oobn, _, _, err := uc.ReadMsgUnix(buf, oob) |
| closeUnix.Stop() |
| |
| scms, err := syscall.ParseSocketControlMessage(oob[:oobn]) |
| if err != nil { |
| t.Fatalf("ParseSocketControlMessage: %v", err) |
| } |
| if len(scms) != 1 { |
| t.Fatalf("expected 1 SocketControlMessage; got scms = %#v", scms) |
| } |
| scm := scms[0] |
| gotFds, err := syscall.ParseUnixRights(&scm) |
| if err != nil { |
| t.Fatalf("syscall.ParseUnixRights: %v", err) |
| } |
| if len(gotFds) != 1 { |
| t.Fatalf("wanted 1 fd; got %#v", gotFds) |
| } |
| |
| f := os.NewFile(uintptr(gotFds[0]), "fd-from-child") |
| defer f.Close() |
| |
| got, err := ioutil.ReadAll(f) |
| want := "Hello from child process!\n" |
| if string(got) != want { |
| t.Errorf("child process ReadAll: %q, %v; want %q", got, err, want) |
| } |
| } |
| |
| // passFDChild is the child process used by TestPassFD. |
| func passFDChild() { |
| defer os.Exit(0) |
| |
| // Look for our fd. It should be fd 3, but we work around an fd leak |
| // bug here (http://golang.org/issue/2603) to let it be elsewhere. |
| var uc *net.UnixConn |
| for fd := uintptr(3); fd <= 10; fd++ { |
| f := os.NewFile(fd, "unix-conn") |
| var ok bool |
| netc, _ := net.FileConn(f) |
| uc, ok = netc.(*net.UnixConn) |
| if ok { |
| break |
| } |
| } |
| if uc == nil { |
| fmt.Println("failed to find unix fd") |
| return |
| } |
| |
| // Make a file f to send to our parent process on uc. |
| // We make it in tempDir, which our parent will clean up. |
| flag.Parse() |
| tempDir := flag.Arg(0) |
| f, err := ioutil.TempFile(tempDir, "") |
| if err != nil { |
| fmt.Printf("TempFile: %v", err) |
| return |
| } |
| |
| f.Write([]byte("Hello from child process!\n")) |
| f.Seek(0, 0) |
| |
| rights := syscall.UnixRights(int(f.Fd())) |
| dummyByte := []byte("x") |
| n, oobn, err := uc.WriteMsgUnix(dummyByte, rights, nil) |
| if err != nil { |
| fmt.Printf("WriteMsgUnix: %v", err) |
| return |
| } |
| if n != 1 || oobn != len(rights) { |
| fmt.Printf("WriteMsgUnix = %d, %d; want 1, %d", n, oobn, len(rights)) |
| return |
| } |
| } |
| |
| // TestUnixRightsRoundtrip tests that UnixRights, ParseSocketControlMessage, |
| // and ParseUnixRights are able to successfully round-trip lists of file descriptors. |
| func TestUnixRightsRoundtrip(t *testing.T) { |
| testCases := [...][][]int{ |
| {{42}}, |
| {{1, 2}}, |
| {{3, 4, 5}}, |
| {{}}, |
| {{1, 2}, {3, 4, 5}, {}, {7}}, |
| } |
| for _, testCase := range testCases { |
| b := []byte{} |
| var n int |
| for _, fds := range testCase { |
| // Last assignment to n wins |
| n = len(b) + syscall.CmsgLen(4*len(fds)) |
| b = append(b, syscall.UnixRights(fds...)...) |
| } |
| // Truncate b |
| b = b[:n] |
| |
| scms, err := syscall.ParseSocketControlMessage(b) |
| if err != nil { |
| t.Fatalf("ParseSocketControlMessage: %v", err) |
| } |
| if len(scms) != len(testCase) { |
| t.Fatalf("expected %v SocketControlMessage; got scms = %#v", len(testCase), scms) |
| } |
| for i, scm := range scms { |
| gotFds, err := syscall.ParseUnixRights(&scm) |
| if err != nil { |
| t.Fatalf("ParseUnixRights: %v", err) |
| } |
| wantFds := testCase[i] |
| if len(gotFds) != len(wantFds) { |
| t.Fatalf("expected %v fds, got %#v", len(wantFds), gotFds) |
| } |
| for j, fd := range gotFds { |
| if fd != wantFds[j] { |
| t.Fatalf("expected fd %v, got %v", wantFds[j], fd) |
| } |
| } |
| } |
| } |
| } |