libgo/go/syscall/syscall_unix_test.go

   1 // Copyright 2013 The Go Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style
   3 // license that can be found in the LICENSE file.
   4
   5 // +build darwin dragonfly freebsd linux netbsd openbsd solaris
   6
   7 package syscall_test
   8
   9 import (
  10         "flag"
  11         "fmt"
  12         "internal/testenv"
  13         "io"
  14         "io/ioutil"
  15         "net"
  16         "os"
  17         "os/exec"
  18         "path/filepath"
  19         "runtime"
  20         "syscall"
  21         "testing"
  22         "time"
  23 )
  24
  25 // Tests that below functions, structures and constants are consistent
  26 // on all Unix-like systems.
  27 func _() {
  28         // program scheduling priority functions and constants
  29         var (
  30                 _ func(int, int, int) error   = syscall.Setpriority
  31                 _ func(int, int) (int, error) = syscall.Getpriority
  32         )
  33         const (
  34                 _ int = syscall.PRIO_USER
  35                 _ int = syscall.PRIO_PROCESS
  36                 _ int = syscall.PRIO_PGRP
  37         )
  38
  39         // termios constants
  40         const (
  41                 _ int = syscall.TCIFLUSH
  42                 _ int = syscall.TCIOFLUSH
  43                 _ int = syscall.TCOFLUSH
  44         )
  45
  46         // fcntl file locking structure and constants
  47         var (
  48                 _ = syscall.Flock_t{
  49                         Type:   int16(0),
  50                         Whence: int16(0),
  51                         Start:  int64(0),
  52                         Len:    int64(0),
  53                         Pid:    int32(0),
  54                 }
  55         )
  56         const (
  57                 _ = syscall.F_GETLK
  58                 _ = syscall.F_SETLK
  59                 _ = syscall.F_SETLKW
  60         )
  61 }
  62
  63 // TestFcntlFlock tests whether the file locking structure matches
  64 // the calling convention of each kernel.
  65 // On some Linux systems, glibc uses another set of values for the
  66 // commands and translates them to the correct value that the kernel
  67 // expects just before the actual fcntl syscall. As Go uses raw
  68 // syscalls directly, it must use the real value, not the glibc value.
  69 // Thus this test also verifies that the Flock_t structure can be
  70 // roundtripped with F_SETLK and F_GETLK.
  71 func TestFcntlFlock(t *testing.T) {
  72         if runtime.GOOS == "darwin" && (runtime.GOARCH == "arm" || runtime.GOARCH == "arm64") {
  73                 t.Skip("skipping; no child processes allowed on iOS")
  74         }
  75         flock := syscall.Flock_t{
  76                 Type:  syscall.F_WRLCK,
  77                 Start: 31415, Len: 271828, Whence: 1,
  78         }
  79         if os.Getenv("GO_WANT_HELPER_PROCESS") == "" {
  80                 // parent
  81                 name := filepath.Join(os.TempDir(), "TestFcntlFlock")
  82                 fd, err := syscall.Open(name, syscall.O_CREAT|syscall.O_RDWR|syscall.O_CLOEXEC, 0)
  83                 if err != nil {
  84                         t.Fatalf("Open failed: %v", err)
  85                 }
  86                 defer syscall.Unlink(name)
  87                 defer syscall.Close(fd)
  88                 if err := syscall.Ftruncate(fd, 1<<20); err != nil {
  89                         t.Fatalf("Ftruncate(1<<20) failed: %v", err)
  90                 }
  91                 if err := syscall.FcntlFlock(uintptr(fd), syscall.F_SETLK, &flock); err != nil {
  92                         t.Fatalf("FcntlFlock(F_SETLK) failed: %v", err)
  93                 }
  94                 cmd := exec.Command(os.Args[0], "-test.run=^TestFcntlFlock$")
  95                 cmd.Env = append(os.Environ(), "GO_WANT_HELPER_PROCESS=1")
  96                 cmd.ExtraFiles = []*os.File{os.NewFile(uintptr(fd), name)}
  97                 out, err := cmd.CombinedOutput()
  98                 if len(out) > 0 || err != nil {
  99                         t.Fatalf("child process: %q, %v", out, err)
 100                 }
 101         } else {
 102                 // child
 103                 got := flock
 104                 // make sure the child lock is conflicting with the parent lock
 105                 got.Start--
 106                 got.Len++
 107                 if err := syscall.FcntlFlock(3, syscall.F_GETLK, &got); err != nil {
 108                         t.Fatalf("FcntlFlock(F_GETLK) failed: %v", err)
 109                 }
 110                 flock.Pid = int32(syscall.Getppid())
 111                 // Linux kernel always set Whence to 0
 112                 flock.Whence = 0
 113                 if got.Type == flock.Type && got.Start == flock.Start && got.Len == flock.Len && got.Pid == flock.Pid && got.Whence == flock.Whence {
 114                         os.Exit(0)
 115                 }
 116                 t.Fatalf("FcntlFlock got %v, want %v", got, flock)
 117         }
 118 }
 119
 120 // TestPassFD tests passing a file descriptor over a Unix socket.
 121 //
 122 // This test involved both a parent and child process. The parent
 123 // process is invoked as a normal test, with "go test", which then
 124 // runs the child process by running the current test binary with args
 125 // "-test.run=^TestPassFD$" and an environment variable used to signal
 126 // that the test should become the child process instead.
 127 func TestPassFD(t *testing.T) {
 128         switch runtime.GOOS {
 129         case "dragonfly":
 130                 // TODO(jsing): Figure out why sendmsg is returning EINVAL.
 131                 t.Skip("skipping test on dragonfly")
 132         case "solaris":
 133                 // TODO(aram): Figure out why ReadMsgUnix is returning empty message.
 134                 t.Skip("skipping test on solaris, see issue 7402")
 135         }
 136
 137         testenv.MustHaveExec(t)
 138
 139         if os.Getenv("GO_WANT_HELPER_PROCESS") == "1" {
 140                 passFDChild()
 141                 return
 142         }
 143
 144         tempDir, err := ioutil.TempDir("", "TestPassFD")
 145         if err != nil {
 146                 t.Fatal(err)
 147         }
 148         defer os.RemoveAll(tempDir)
 149
 150         fds, err := syscall.Socketpair(syscall.AF_LOCAL, syscall.SOCK_STREAM, 0)
 151         if err != nil {
 152                 t.Fatalf("Socketpair: %v", err)
 153         }
 154         defer syscall.Close(fds[0])
 155         defer syscall.Close(fds[1])
 156         writeFile := os.NewFile(uintptr(fds[0]), "child-writes")
 157         readFile := os.NewFile(uintptr(fds[1]), "parent-reads")
 158         defer writeFile.Close()
 159         defer readFile.Close()
 160
 161         cmd := exec.Command(os.Args[0], "-test.run=^TestPassFD$", "--", tempDir)
 162         cmd.Env = append(os.Environ(), "GO_WANT_HELPER_PROCESS=1")
 163         cmd.ExtraFiles = []*os.File{writeFile}
 164
 165         out, err := cmd.CombinedOutput()
 166         if len(out) > 0 || err != nil {
 167                 t.Fatalf("child process: %q, %v", out, err)
 168         }
 169
 170         c, err := net.FileConn(readFile)
 171         if err != nil {
 172                 t.Fatalf("FileConn: %v", err)
 173         }
 174         defer c.Close()
 175
 176         uc, ok := c.(*net.UnixConn)
 177         if !ok {
 178                 t.Fatalf("unexpected FileConn type; expected UnixConn, got %T", c)
 179         }
 180
 181         buf := make([]byte, 32) // expect 1 byte
 182         oob := make([]byte, 32) // expect 24 bytes
 183         closeUnix := time.AfterFunc(5*time.Second, func() {
 184                 t.Logf("timeout reading from unix socket")
 185                 uc.Close()
 186         })
 187         _, oobn, _, _, err := uc.ReadMsgUnix(buf, oob)
 188         closeUnix.Stop()
 189
 190         scms, err := syscall.ParseSocketControlMessage(oob[:oobn])
 191         if err != nil {
 192                 t.Fatalf("ParseSocketControlMessage: %v", err)
 193         }
 194         if len(scms) != 1 {
 195                 t.Fatalf("expected 1 SocketControlMessage; got scms = %#v", scms)
 196         }
 197         scm := scms[0]
 198         gotFds, err := syscall.ParseUnixRights(&scm)
 199         if err != nil {
 200                 t.Fatalf("syscall.ParseUnixRights: %v", err)
 201         }
 202         if len(gotFds) != 1 {
 203                 t.Fatalf("wanted 1 fd; got %#v", gotFds)
 204         }
 205
 206         f := os.NewFile(uintptr(gotFds[0]), "fd-from-child")
 207         defer f.Close()
 208
 209         got, err := ioutil.ReadAll(f)
 210         want := "Hello from child process!\n"
 211         if string(got) != want {
 212                 t.Errorf("child process ReadAll: %q, %v; want %q", got, err, want)
 213         }
 214 }
 215
 216 // passFDChild is the child process used by TestPassFD.
 217 func passFDChild() {
 218         defer os.Exit(0)
 219
 220         // Look for our fd. It should be fd 3, but we work around an fd leak
 221         // bug here (https://golang.org/issue/2603) to let it be elsewhere.
 222         var uc *net.UnixConn
 223         for fd := uintptr(3); fd <= 10; fd++ {
 224                 f := os.NewFile(fd, "unix-conn")
 225                 var ok bool
 226                 netc, _ := net.FileConn(f)
 227                 uc, ok = netc.(*net.UnixConn)
 228                 if ok {
 229                         break
 230                 }
 231         }
 232         if uc == nil {
 233                 fmt.Println("failed to find unix fd")
 234                 return
 235         }
 236
 237         // Make a file f to send to our parent process on uc.
 238         // We make it in tempDir, which our parent will clean up.
 239         flag.Parse()
 240         tempDir := flag.Arg(0)
 241         f, err := ioutil.TempFile(tempDir, "")
 242         if err != nil {
 243                 fmt.Printf("TempFile: %v", err)
 244                 return
 245         }
 246
 247         f.Write([]byte("Hello from child process!\n"))
 248         f.Seek(0, io.SeekStart)
 249
 250         rights := syscall.UnixRights(int(f.Fd()))
 251         dummyByte := []byte("x")
 252         n, oobn, err := uc.WriteMsgUnix(dummyByte, rights, nil)
 253         if err != nil {
 254                 fmt.Printf("WriteMsgUnix: %v", err)
 255                 return
 256         }
 257         if n != 1 || oobn != len(rights) {
 258                 fmt.Printf("WriteMsgUnix = %d, %d; want 1, %d", n, oobn, len(rights))
 259                 return
 260         }
 261 }
 262
 263 // TestUnixRightsRoundtrip tests that UnixRights, ParseSocketControlMessage,
 264 // and ParseUnixRights are able to successfully round-trip lists of file descriptors.
 265 func TestUnixRightsRoundtrip(t *testing.T) {
 266         testCases := [...][][]int{
 267                 {{42}},
 268                 {{1, 2}},
 269                 {{3, 4, 5}},
 270                 {{}},
 271                 {{1, 2}, {3, 4, 5}, {}, {7}},
 272         }
 273         for _, testCase := range testCases {
 274                 b := []byte{}
 275                 var n int
 276                 for _, fds := range testCase {
 277                         // Last assignment to n wins
 278                         n = len(b) + syscall.CmsgLen(4*len(fds))
 279                         b = append(b, syscall.UnixRights(fds...)...)
 280                 }
 281                 // Truncate b
 282                 b = b[:n]
 283
 284                 scms, err := syscall.ParseSocketControlMessage(b)
 285                 if err != nil {
 286                         t.Fatalf("ParseSocketControlMessage: %v", err)
 287                 }
 288                 if len(scms) != len(testCase) {
 289                         t.Fatalf("expected %v SocketControlMessage; got scms = %#v", len(testCase), scms)
 290                 }
 291                 for i, scm := range scms {
 292                         gotFds, err := syscall.ParseUnixRights(&scm)
 293                         if err != nil {
 294                                 t.Fatalf("ParseUnixRights: %v", err)
 295                         }
 296                         wantFds := testCase[i]
 297                         if len(gotFds) != len(wantFds) {
 298                                 t.Fatalf("expected %v fds, got %#v", len(wantFds), gotFds)
 299                         }
 300                         for j, fd := range gotFds {
 301                                 if fd != wantFds[j] {
 302                                         t.Fatalf("expected fd %v, got %v", wantFds[j], fd)
 303                                 }
 304                         }
 305                 }
 306         }
 307 }
 308
 309 func TestRlimit(t *testing.T) {
 310         var rlimit, zero syscall.Rlimit
 311         err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rlimit)
 312         if err != nil {
 313                 t.Fatalf("Getrlimit: save failed: %v", err)
 314         }
 315         if zero == rlimit {
 316                 t.Fatalf("Getrlimit: save failed: got zero value %#v", rlimit)
 317         }
 318         set := rlimit
 319         set.Cur = set.Max - 1
 320         err = syscall.Setrlimit(syscall.RLIMIT_NOFILE, &set)
 321         if err != nil {
 322                 t.Fatalf("Setrlimit: set failed: %#v %v", set, err)
 323         }
 324         var get syscall.Rlimit
 325         err = syscall.Getrlimit(syscall.RLIMIT_NOFILE, &get)
 326         if err != nil {
 327                 t.Fatalf("Getrlimit: get failed: %v", err)
 328         }
 329         set = rlimit
 330         set.Cur = set.Max - 1
 331         if set != get {
 332                 // Seems like Darwin requires some privilege to
 333                 // increase the soft limit of rlimit sandbox, though
 334                 // Setrlimit never reports an error.
 335                 switch runtime.GOOS {
 336                 case "darwin":
 337                 default:
 338                         t.Fatalf("Rlimit: change failed: wanted %#v got %#v", set, get)
 339                 }
 340         }
 341         err = syscall.Setrlimit(syscall.RLIMIT_NOFILE, &rlimit)
 342         if err != nil {
 343                 t.Fatalf("Setrlimit: restore failed: %#v %v", rlimit, err)
 344         }
 345 }
 346
 347 func TestSeekFailure(t *testing.T) {
 348         _, err := syscall.Seek(-1, 0, io.SeekStart)
 349         if err == nil {
 350                 t.Fatalf("Seek(-1, 0, 0) did not fail")
 351         }
 352         str := err.Error() // used to crash on Linux
 353         t.Logf("Seek: %v", str)
 354         if str == "" {
 355                 t.Fatalf("Seek(-1, 0, 0) return error with empty message")
 356         }
 357 }