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// Package root_test contains tests that need root
// permissions to run
package root_test
import (
"io/ioutil"
"os"
"os/exec"
"path/filepath"
"runtime"
"sync"
"syscall"
"testing"
"golang.org/x/sys/unix"
"github.com/rfjakob/gocryptfs/tests/test_helpers"
)
func asUser(uid int, gid int, supplementaryGroups []int, f func() error) error {
runtime.LockOSThread()
defer runtime.UnlockOSThread()
err := unix.Setgroups(supplementaryGroups)
if err != nil {
return err
}
defer func() {
err = unix.Setgroups(nil)
if err != nil {
panic(err)
}
}()
err = unix.Setregid(-1, gid)
if err != nil {
return err
}
defer func() {
err = unix.Setregid(-1, 0)
if err != nil {
panic(err)
}
}()
err = unix.Setreuid(-1, uid)
if err != nil {
return err
}
defer func() {
err = unix.Setreuid(-1, 0)
if err != nil {
panic(err)
}
}()
ret := f()
// Also reset the saved user id (suid) and saved group id (sgid) to prevent
// bizarre failures in later tests.
//
// Yes, the kernel checks that *all of them* match:
// https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/fs/fuse/dir.c?h=v5.12-rc2#n1193
//
// How to check:
// ps -o tid,pid,euid,ruid,suid,egid,rgid,sgid,cmd -eL
err = unix.Setresuid(0, 0, 0)
if err != nil {
panic(err)
}
err = unix.Setresgid(0, 0, 0)
if err != nil {
panic(err)
}
return ret
}
func TestSupplementaryGroups(t *testing.T) {
if os.Getuid() != 0 {
t.Skip("must run as root")
}
cDir := test_helpers.InitFS(t)
os.Chmod(cDir, 0755)
pDir := cDir + ".mnt"
test_helpers.MountOrFatal(t, cDir, pDir, "-allow_other", "-extpass=echo test")
defer test_helpers.UnmountPanic(pDir)
// We need an unrestricted umask
syscall.Umask(0000)
dir1 := pDir + "/dir1"
err := os.Mkdir(dir1, 0770)
if err != nil {
t.Fatal(err)
}
err = os.Chown(dir1, 0, 1234)
if err != nil {
t.Fatal(err)
}
err = asUser(1235, 1235, []int{1234}, func() error { return os.Mkdir(dir1+"/dir2", 0700) })
if err != nil {
t.Error(err)
}
err = asUser(1235, 1235, []int{1234}, func() error {
f, err := os.Create(dir1 + "/file1")
if err == nil {
f.Close()
}
return err
})
if err != nil {
t.Error(err)
}
}
func writeTillFull(t *testing.T, path string) (int, syscall.Errno) {
runtime.LockOSThread()
defer runtime.UnlockOSThread()
fd, err := syscall.Creat(path, 0600)
if err != nil {
return 0, err.(syscall.Errno)
}
defer syscall.Close(fd)
// Write in 100.000 byte-blocks, which is not aligend to the
// underlying block size
buf := make([]byte, 100000)
var sz int
for {
n, err := syscall.Write(fd, buf)
if err != nil {
return sz, err.(syscall.Errno)
}
sz += n
}
return sz, 0
}
func TestDiskFull(t *testing.T) {
if os.Getuid() != 0 {
t.Skip("must run as root")
}
// Create 10 MB file full of zeros
ext4img := filepath.Join(test_helpers.TmpDir, t.Name()+".ext4")
f, err := os.Create(ext4img)
if err != nil {
t.Fatal(err)
}
defer f.Close()
err = f.Truncate(10 * 1024 * 1024)
if err != nil {
t.Fatal(err)
}
// Format as ext4
cmd := exec.Command("mkfs.ext4", ext4img)
out, err := cmd.CombinedOutput()
if err != nil {
t.Log(string(out))
t.Fatal(err)
}
// Mount ext4
ext4mnt := ext4img + ".mnt"
err = os.Mkdir(ext4mnt, 0600)
if err != nil {
t.Fatal(err)
}
cmd = exec.Command("mount", ext4img, ext4mnt)
out, err = cmd.CombinedOutput()
if err != nil {
t.Log(string(out))
t.Fatal(err)
}
defer syscall.Unlink(ext4img)
defer syscall.Unmount(ext4mnt, 0)
// gocryptfs -init
cipherdir := ext4mnt + "/a"
if err = os.Mkdir(cipherdir, 0600); err != nil {
t.Fatal(err)
}
cmd = exec.Command(test_helpers.GocryptfsBinary, "-q", "-init", "-extpass", "echo test", "-scryptn=10", cipherdir)
out, err = cmd.CombinedOutput()
if err != nil {
t.Log(string(out))
t.Fatal(err)
}
// Mount gocryptfs
mnt := ext4mnt + "/b"
test_helpers.MountOrFatal(t, cipherdir, mnt, "-extpass", "echo test")
defer test_helpers.UnmountPanic(mnt)
// Write till we get ENOSPC
var err1, err2 error
var sz1, sz2 int
var wg sync.WaitGroup
wg.Add(2)
go func() {
sz1, err1 = writeTillFull(t, mnt+"/foo1")
wg.Done()
}()
go func() {
sz2, err2 = writeTillFull(t, mnt+"/foo2")
wg.Done()
}()
wg.Wait()
if err1 != syscall.ENOSPC || err2 != syscall.ENOSPC {
t.Fatalf("err1=%v, err2=%v", err1, err2)
}
t.Logf("sz1=%d, sz2=%d", sz1, sz2)
foo1, err := ioutil.ReadFile(mnt + "/foo1")
if err != nil {
t.Fatal(err)
}
if len(foo1) != sz1 {
t.Fail()
}
foo2, err := ioutil.ReadFile(mnt + "/foo2")
if err != nil {
t.Fatal(err)
}
if len(foo2) != sz2 {
t.Fail()
}
}
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