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