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
7package syscall_test
8
9import (
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.
27func _() {
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.
71func 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		tempDir, err := ioutil.TempDir("", "TestFcntlFlock")
82		if err != nil {
83			t.Fatalf("Failed to create temp dir: %v", err)
84		}
85		name := filepath.Join(tempDir, "TestFcntlFlock")
86		fd, err := syscall.Open(name, syscall.O_CREAT|syscall.O_RDWR|syscall.O_CLOEXEC, 0)
87		if err != nil {
88			t.Fatalf("Open failed: %v", err)
89		}
90		defer os.RemoveAll(tempDir)
91		defer syscall.Close(fd)
92		if err := syscall.Ftruncate(fd, 1<<20); err != nil {
93			t.Fatalf("Ftruncate(1<<20) failed: %v", err)
94		}
95		if err := syscall.FcntlFlock(uintptr(fd), syscall.F_SETLK, &flock); err != nil {
96			t.Fatalf("FcntlFlock(F_SETLK) failed: %v", err)
97		}
98		cmd := exec.Command(os.Args[0], "-test.run=^TestFcntlFlock$")
99		cmd.Env = append(os.Environ(), "GO_WANT_HELPER_PROCESS=1")
100		cmd.ExtraFiles = []*os.File{os.NewFile(uintptr(fd), name)}
101		out, err := cmd.CombinedOutput()
102		if len(out) > 0 || err != nil {
103			t.Fatalf("child process: %q, %v", out, err)
104		}
105	} else {
106		// child
107		got := flock
108		// make sure the child lock is conflicting with the parent lock
109		got.Start--
110		got.Len++
111		if err := syscall.FcntlFlock(3, syscall.F_GETLK, &got); err != nil {
112			t.Fatalf("FcntlFlock(F_GETLK) failed: %v", err)
113		}
114		flock.Pid = int32(syscall.Getppid())
115		// Linux kernel always set Whence to 0
116		flock.Whence = 0
117		if got.Type == flock.Type && got.Start == flock.Start && got.Len == flock.Len && got.Pid == flock.Pid && got.Whence == flock.Whence {
118			os.Exit(0)
119		}
120		t.Fatalf("FcntlFlock got %v, want %v", got, flock)
121	}
122}
123
124// TestPassFD tests passing a file descriptor over a Unix socket.
125//
126// This test involved both a parent and child process. The parent
127// process is invoked as a normal test, with "go test", which then
128// runs the child process by running the current test binary with args
129// "-test.run=^TestPassFD$" and an environment variable used to signal
130// that the test should become the child process instead.
131func TestPassFD(t *testing.T) {
132	testenv.MustHaveExec(t)
133
134	if os.Getenv("GO_WANT_HELPER_PROCESS") == "1" {
135		passFDChild()
136		return
137	}
138
139	tempDir, err := ioutil.TempDir("", "TestPassFD")
140	if err != nil {
141		t.Fatal(err)
142	}
143	defer os.RemoveAll(tempDir)
144
145	fds, err := syscall.Socketpair(syscall.AF_LOCAL, syscall.SOCK_STREAM, 0)
146	if err != nil {
147		t.Fatalf("Socketpair: %v", err)
148	}
149	defer syscall.Close(fds[0])
150	defer syscall.Close(fds[1])
151	writeFile := os.NewFile(uintptr(fds[0]), "child-writes")
152	readFile := os.NewFile(uintptr(fds[1]), "parent-reads")
153	defer writeFile.Close()
154	defer readFile.Close()
155
156	cmd := exec.Command(os.Args[0], "-test.run=^TestPassFD$", "--", tempDir)
157	cmd.Env = append(os.Environ(), "GO_WANT_HELPER_PROCESS=1")
158	cmd.ExtraFiles = []*os.File{writeFile}
159
160	out, err := cmd.CombinedOutput()
161	if len(out) > 0 || err != nil {
162		t.Fatalf("child process: %q, %v", out, err)
163	}
164
165	c, err := net.FileConn(readFile)
166	if err != nil {
167		t.Fatalf("FileConn: %v", err)
168	}
169	defer c.Close()
170
171	uc, ok := c.(*net.UnixConn)
172	if !ok {
173		t.Fatalf("unexpected FileConn type; expected UnixConn, got %T", c)
174	}
175
176	buf := make([]byte, 32) // expect 1 byte
177	oob := make([]byte, 32) // expect 24 bytes
178	closeUnix := time.AfterFunc(5*time.Second, func() {
179		t.Logf("timeout reading from unix socket")
180		uc.Close()
181	})
182	_, oobn, _, _, err := uc.ReadMsgUnix(buf, oob)
183	if err != nil {
184		t.Fatalf("ReadMsgUnix: %v", err)
185	}
186	closeUnix.Stop()
187
188	scms, err := syscall.ParseSocketControlMessage(oob[:oobn])
189	if err != nil {
190		t.Fatalf("ParseSocketControlMessage: %v", err)
191	}
192	if len(scms) != 1 {
193		t.Fatalf("expected 1 SocketControlMessage; got scms = %#v", scms)
194	}
195	scm := scms[0]
196	gotFds, err := syscall.ParseUnixRights(&scm)
197	if err != nil {
198		t.Fatalf("syscall.ParseUnixRights: %v", err)
199	}
200	if len(gotFds) != 1 {
201		t.Fatalf("wanted 1 fd; got %#v", gotFds)
202	}
203
204	f := os.NewFile(uintptr(gotFds[0]), "fd-from-child")
205	defer f.Close()
206
207	got, err := ioutil.ReadAll(f)
208	want := "Hello from child process!\n"
209	if string(got) != want {
210		t.Errorf("child process ReadAll: %q, %v; want %q", got, err, want)
211	}
212}
213
214// passFDChild is the child process used by TestPassFD.
215func passFDChild() {
216	defer os.Exit(0)
217
218	// Look for our fd. It should be fd 3, but we work around an fd leak
219	// bug here (https://golang.org/issue/2603) to let it be elsewhere.
220	var uc *net.UnixConn
221	for fd := uintptr(3); fd <= 10; fd++ {
222		f := os.NewFile(fd, "unix-conn")
223		var ok bool
224		netc, _ := net.FileConn(f)
225		uc, ok = netc.(*net.UnixConn)
226		if ok {
227			break
228		}
229	}
230	if uc == nil {
231		fmt.Println("failed to find unix fd")
232		return
233	}
234
235	// Make a file f to send to our parent process on uc.
236	// We make it in tempDir, which our parent will clean up.
237	flag.Parse()
238	tempDir := flag.Arg(0)
239	f, err := ioutil.TempFile(tempDir, "")
240	if err != nil {
241		fmt.Printf("TempFile: %v", err)
242		return
243	}
244
245	f.Write([]byte("Hello from child process!\n"))
246	f.Seek(0, io.SeekStart)
247
248	rights := syscall.UnixRights(int(f.Fd()))
249	dummyByte := []byte("x")
250	n, oobn, err := uc.WriteMsgUnix(dummyByte, rights, nil)
251	if err != nil {
252		fmt.Printf("WriteMsgUnix: %v", err)
253		return
254	}
255	if n != 1 || oobn != len(rights) {
256		fmt.Printf("WriteMsgUnix = %d, %d; want 1, %d", n, oobn, len(rights))
257		return
258	}
259}
260
261// TestUnixRightsRoundtrip tests that UnixRights, ParseSocketControlMessage,
262// and ParseUnixRights are able to successfully round-trip lists of file descriptors.
263func TestUnixRightsRoundtrip(t *testing.T) {
264	testCases := [...][][]int{
265		{{42}},
266		{{1, 2}},
267		{{3, 4, 5}},
268		{{}},
269		{{1, 2}, {3, 4, 5}, {}, {7}},
270	}
271	for _, testCase := range testCases {
272		b := []byte{}
273		var n int
274		for _, fds := range testCase {
275			// Last assignment to n wins
276			n = len(b) + syscall.CmsgLen(4*len(fds))
277			b = append(b, syscall.UnixRights(fds...)...)
278		}
279		// Truncate b
280		b = b[:n]
281
282		scms, err := syscall.ParseSocketControlMessage(b)
283		if err != nil {
284			t.Fatalf("ParseSocketControlMessage: %v", err)
285		}
286		if len(scms) != len(testCase) {
287			t.Fatalf("expected %v SocketControlMessage; got scms = %#v", len(testCase), scms)
288		}
289		for i, scm := range scms {
290			gotFds, err := syscall.ParseUnixRights(&scm)
291			if err != nil {
292				t.Fatalf("ParseUnixRights: %v", err)
293			}
294			wantFds := testCase[i]
295			if len(gotFds) != len(wantFds) {
296				t.Fatalf("expected %v fds, got %#v", len(wantFds), gotFds)
297			}
298			for j, fd := range gotFds {
299				if fd != wantFds[j] {
300					t.Fatalf("expected fd %v, got %v", wantFds[j], fd)
301				}
302			}
303		}
304	}
305}
306
307func TestRlimit(t *testing.T) {
308	var rlimit, zero syscall.Rlimit
309	err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rlimit)
310	if err != nil {
311		t.Fatalf("Getrlimit: save failed: %v", err)
312	}
313	if zero == rlimit {
314		t.Fatalf("Getrlimit: save failed: got zero value %#v", rlimit)
315	}
316	set := rlimit
317	set.Cur = set.Max - 1
318	err = syscall.Setrlimit(syscall.RLIMIT_NOFILE, &set)
319	if err != nil {
320		t.Fatalf("Setrlimit: set failed: %#v %v", set, err)
321	}
322	var get syscall.Rlimit
323	err = syscall.Getrlimit(syscall.RLIMIT_NOFILE, &get)
324	if err != nil {
325		t.Fatalf("Getrlimit: get failed: %v", err)
326	}
327	set = rlimit
328	set.Cur = set.Max - 1
329	if set != get {
330		// Seems like Darwin requires some privilege to
331		// increase the soft limit of rlimit sandbox, though
332		// Setrlimit never reports an error.
333		switch runtime.GOOS {
334		case "darwin":
335		default:
336			t.Fatalf("Rlimit: change failed: wanted %#v got %#v", set, get)
337		}
338	}
339	err = syscall.Setrlimit(syscall.RLIMIT_NOFILE, &rlimit)
340	if err != nil {
341		t.Fatalf("Setrlimit: restore failed: %#v %v", rlimit, err)
342	}
343}
344
345func TestSeekFailure(t *testing.T) {
346	_, err := syscall.Seek(-1, 0, io.SeekStart)
347	if err == nil {
348		t.Fatalf("Seek(-1, 0, 0) did not fail")
349	}
350	str := err.Error() // used to crash on Linux
351	t.Logf("Seek: %v", str)
352	if str == "" {
353		t.Fatalf("Seek(-1, 0, 0) return error with empty message")
354	}
355}
356