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// Copyright 2013 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 darwin dragonfly freebsd linux netbsd openbsd solaris
package syscall_test
import (
"flag"
"fmt"
"internal/testenv"
"io"
"io/ioutil"
"net"
"os"
"os/exec"
"path/filepath"
"runtime"
"syscall"
"testing"
"time"
)
// Tests that below functions, structures and constants are consistent
// on all Unix-like systems.
func _() {
// program scheduling priority functions and constants
var (
_ func(int, int, int) error = syscall.Setpriority
_ func(int, int) (int, error) = syscall.Getpriority
)
const (
_ int = syscall.PRIO_USER
_ int = syscall.PRIO_PROCESS
_ int = syscall.PRIO_PGRP
)
// termios constants
const (
_ int = syscall.TCIFLUSH
_ int = syscall.TCIOFLUSH
_ int = syscall.TCOFLUSH
)
// fcntl file locking structure and constants
var (
_ = syscall.Flock_t{
Type: int16(0),
Whence: int16(0),
Start: int64(0),
Len: int64(0),
Pid: int32(0),
}
)
const (
_ = syscall.F_GETLK
_ = syscall.F_SETLK
_ = syscall.F_SETLKW
)
}
// TestFcntlFlock tests whether the file locking structure matches
// the calling convention of each kernel.
// On some Linux systems, glibc uses another set of values for the
// commands and translates them to the correct value that the kernel
// expects just before the actual fcntl syscall. As Go uses raw
// syscalls directly, it must use the real value, not the glibc value.
// Thus this test also verifies that the Flock_t structure can be
// roundtripped with F_SETLK and F_GETLK.
func TestFcntlFlock(t *testing.T) {
if runtime.GOOS == "darwin" && (runtime.GOARCH == "arm" || runtime.GOARCH == "arm64") {
t.Skip("skipping; no child processes allowed on iOS")
}
flock := syscall.Flock_t{
Type: syscall.F_WRLCK,
Start: 31415, Len: 271828, Whence: 1,
}
if os.Getenv("GO_WANT_HELPER_PROCESS") == "" {
// parent
tempDir, err := ioutil.TempDir("", "TestFcntlFlock")
if err != nil {
t.Fatalf("Failed to create temp dir: %v", err)
}
name := filepath.Join(tempDir, "TestFcntlFlock")
fd, err := syscall.Open(name, syscall.O_CREAT|syscall.O_RDWR|syscall.O_CLOEXEC, 0)
if err != nil {
t.Fatalf("Open failed: %v", err)
}
defer os.RemoveAll(tempDir)
defer syscall.Close(fd)
if err := syscall.Ftruncate(fd, 1<<20); err != nil {
t.Fatalf("Ftruncate(1<<20) failed: %v", err)
}
if err := syscall.FcntlFlock(uintptr(fd), syscall.F_SETLK, &flock); err != nil {
t.Fatalf("FcntlFlock(F_SETLK) failed: %v", err)
}
cmd := exec.Command(os.Args[0], "-test.run=^TestFcntlFlock$")
cmd.Env = append(os.Environ(), "GO_WANT_HELPER_PROCESS=1")
cmd.ExtraFiles = []*os.File{os.NewFile(uintptr(fd), name)}
out, err := cmd.CombinedOutput()
if len(out) > 0 || err != nil {
t.Fatalf("child process: %q, %v", out, err)
}
} else {
// child
got := flock
// make sure the child lock is conflicting with the parent lock
got.Start--
got.Len++
if err := syscall.FcntlFlock(3, syscall.F_GETLK, &got); err != nil {
t.Fatalf("FcntlFlock(F_GETLK) failed: %v", err)
}
flock.Pid = int32(syscall.Getppid())
// Linux kernel always set Whence to 0
flock.Whence = 0
if got.Type == flock.Type && got.Start == flock.Start && got.Len == flock.Len && got.Pid == flock.Pid && got.Whence == flock.Whence {
os.Exit(0)
}
t.Fatalf("FcntlFlock got %v, want %v", got, flock)
}
}
// TestPassFD tests passing a file descriptor over a Unix socket.
//
// This test involved both a parent and child process. The parent
// process is invoked as a normal test, with "go test", which then
// runs the child process by running the current test binary with args
// "-test.run=^TestPassFD$" and an environment variable used to signal
// that the test should become the child process instead.
func TestPassFD(t *testing.T) {
testenv.MustHaveExec(t)
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 = append(os.Environ(), "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)
if err != nil {
t.Fatalf("ReadMsgUnix: %v", err)
}
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 (https://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, io.SeekStart)
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)
}
}
}
}
}
func TestRlimit(t *testing.T) {
var rlimit, zero syscall.Rlimit
err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rlimit)
if err != nil {
t.Fatalf("Getrlimit: save failed: %v", err)
}
if zero == rlimit {
t.Fatalf("Getrlimit: save failed: got zero value %#v", rlimit)
}
set := rlimit
set.Cur = set.Max - 1
err = syscall.Setrlimit(syscall.RLIMIT_NOFILE, &set)
if err != nil {
t.Fatalf("Setrlimit: set failed: %#v %v", set, err)
}
var get syscall.Rlimit
err = syscall.Getrlimit(syscall.RLIMIT_NOFILE, &get)
if err != nil {
t.Fatalf("Getrlimit: get failed: %v", err)
}
set = rlimit
set.Cur = set.Max - 1
if set != get {
// Seems like Darwin requires some privilege to
// increase the soft limit of rlimit sandbox, though
// Setrlimit never reports an error.
switch runtime.GOOS {
case "darwin":
default:
t.Fatalf("Rlimit: change failed: wanted %#v got %#v", set, get)
}
}
err = syscall.Setrlimit(syscall.RLIMIT_NOFILE, &rlimit)
if err != nil {
t.Fatalf("Setrlimit: restore failed: %#v %v", rlimit, err)
}
}
func TestSeekFailure(t *testing.T) {
_, err := syscall.Seek(-1, 0, io.SeekStart)
if err == nil {
t.Fatalf("Seek(-1, 0, 0) did not fail")
}
str := err.Error() // used to crash on Linux
t.Logf("Seek: %v", str)
if str == "" {
t.Fatalf("Seek(-1, 0, 0) return error with empty message")
}
}