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Diffstat (limited to 'runsc/fsgofer/fsgofer.go')
-rw-r--r--runsc/fsgofer/fsgofer.go258
1 files changed, 138 insertions, 120 deletions
diff --git a/runsc/fsgofer/fsgofer.go b/runsc/fsgofer/fsgofer.go
index 639de9ca1..b0788bd23 100644
--- a/runsc/fsgofer/fsgofer.go
+++ b/runsc/fsgofer/fsgofer.go
@@ -29,7 +29,6 @@ import (
"path/filepath"
"runtime"
"strconv"
- "syscall"
"golang.org/x/sys/unix"
"gvisor.dev/gvisor/pkg/abi/linux"
@@ -45,7 +44,7 @@ const (
// modes to ensure an unopened/closed file fails all mode checks.
invalidMode = p9.OpenFlags(math.MaxUint32)
- openFlags = syscall.O_NOFOLLOW | syscall.O_CLOEXEC
+ openFlags = unix.O_NOFOLLOW | unix.O_CLOEXEC
allowedOpenFlags = unix.O_TRUNC
)
@@ -125,7 +124,7 @@ func (a *attachPoint) Attach() (p9.File, error) {
}
// makeQID returns a unique QID for the given stat buffer.
-func (a *attachPoint) makeQID(stat syscall.Stat_t) p9.QID {
+func (a *attachPoint) makeQID(stat unix.Stat_t) p9.QID {
a.deviceMu.Lock()
defer a.deviceMu.Unlock()
@@ -156,9 +155,7 @@ func (a *attachPoint) makeQID(stat syscall.Stat_t) p9.QID {
// localFile implements p9.File wrapping a local file. The underlying file
// is opened during Walk() and stored in 'file' to be used with other
// operations. The file is opened as readonly, unless it's a symlink or there is
-// no read access, which requires O_PATH. 'file' is dup'ed when Walk(nil) is
-// called to clone the file. This reduces the number of walks that need to be
-// done by the host file system when files are reused.
+// no read access, which requires O_PATH.
//
// The file may be reopened if the requested mode in Open() is not a subset of
// current mode. Consequently, 'file' could have a mode wider than requested and
@@ -170,11 +167,28 @@ func (a *attachPoint) makeQID(stat syscall.Stat_t) p9.QID {
// performance with 'overlay2' storage driver. overlay2 eagerly copies the
// entire file up when it's opened in write mode, and would perform badly when
// multiple files are only being opened for read (esp. startup).
+//
+// File operations must use "at" functions whenever possible:
+// * Local operations must use AT_EMPTY_PATH:
+// fchownat(fd, "", AT_EMPTY_PATH, ...), instead of chown(fullpath, ...)
+// * Creation operations must use (fd + name):
+// mkdirat(fd, name, ...), instead of mkdir(fullpath, ...)
+//
+// Apart from being faster, it also adds another layer of defense against
+// symlink attacks (note that O_NOFOLLOW applies only to the last element in
+// the path).
+//
+// The few exceptions where it cannot be done are: utimensat on symlinks, and
+// Connect() for the socket address.
type localFile struct {
// attachPoint is the attachPoint that serves this localFile.
attachPoint *attachPoint
- // hostPath will be safely updated by the Renamed hook.
+ // hostPath is the full path to the host file. It can be used for logging and
+ // the few cases where full path is required to operation the host file. In
+ // all other cases, use "file" directly.
+ //
+ // Note: it's safely updated by the Renamed hook.
hostPath string
// file is opened when localFile is created and it's never nil. It may be
@@ -191,7 +205,7 @@ type localFile struct {
mode p9.OpenFlags
// fileType for this file. It is equivalent to:
- // syscall.Stat_t.Mode & syscall.S_IFMT
+ // unix.Stat_t.Mode & unix.S_IFMT
fileType uint32
qid p9.QID
@@ -211,7 +225,7 @@ var procSelfFD *fd.FD
// OpenProcSelfFD opens the /proc/self/fd directory, which will be used to
// reopen file descriptors.
func OpenProcSelfFD() error {
- d, err := syscall.Open("/proc/self/fd", syscall.O_RDONLY|syscall.O_DIRECTORY, 0)
+ d, err := unix.Open("/proc/self/fd", unix.O_RDONLY|unix.O_DIRECTORY, 0)
if err != nil {
return fmt.Errorf("error opening /proc/self/fd: %v", err)
}
@@ -220,7 +234,7 @@ func OpenProcSelfFD() error {
}
func reopenProcFd(f *fd.FD, mode int) (*fd.FD, error) {
- d, err := syscall.Openat(int(procSelfFD.FD()), strconv.Itoa(f.FD()), mode&^syscall.O_NOFOLLOW, 0)
+ d, err := unix.Openat(int(procSelfFD.FD()), strconv.Itoa(f.FD()), mode&^unix.O_NOFOLLOW, 0)
if err != nil {
return nil, err
}
@@ -229,17 +243,17 @@ func reopenProcFd(f *fd.FD, mode int) (*fd.FD, error) {
}
func openAnyFileFromParent(parent *localFile, name string) (*fd.FD, string, bool, error) {
- path := path.Join(parent.hostPath, name)
- f, readable, err := openAnyFile(path, func(mode int) (*fd.FD, error) {
+ pathDebug := path.Join(parent.hostPath, name)
+ f, readable, err := openAnyFile(pathDebug, func(mode int) (*fd.FD, error) {
return fd.OpenAt(parent.file, name, openFlags|mode, 0)
})
- return f, path, readable, err
+ return f, pathDebug, readable, err
}
-// openAnyFile attempts to open the file in O_RDONLY and if it fails fallsback
+// openAnyFile attempts to open the file in O_RDONLY. If it fails, falls back
// to O_PATH. 'path' is used for logging messages only. 'fn' is what does the
// actual file open and is customizable by the caller.
-func openAnyFile(path string, fn func(mode int) (*fd.FD, error)) (*fd.FD, bool, error) {
+func openAnyFile(pathDebug string, fn func(mode int) (*fd.FD, error)) (*fd.FD, bool, error) {
// Attempt to open file in the following mode in order:
// 1. RDONLY | NONBLOCK: for all files, directories, ro mounts, FIFOs.
// Use non-blocking to prevent getting stuck inside open(2) for
@@ -250,7 +264,7 @@ func openAnyFile(path string, fn func(mode int) (*fd.FD, error)) (*fd.FD, bool,
readable bool
}{
{
- mode: syscall.O_RDONLY | syscall.O_NONBLOCK,
+ mode: unix.O_RDONLY | unix.O_NONBLOCK,
readable: true,
},
{
@@ -268,36 +282,36 @@ func openAnyFile(path string, fn func(mode int) (*fd.FD, error)) (*fd.FD, bool,
return file, option.readable, nil
}
switch e := extractErrno(err); e {
- case syscall.ENOENT:
+ case unix.ENOENT:
// File doesn't exist, no point in retrying.
return nil, false, e
}
// File failed to open. Try again with next mode, preserving 'err' in case
// this was the last attempt.
- log.Debugf("Attempt %d to open file failed, mode: %#x, path: %q, err: %v", i, openFlags|option.mode, path, err)
+ log.Debugf("Attempt %d to open file failed, mode: %#x, path: %q, err: %v", i, openFlags|option.mode, pathDebug, err)
}
// All attempts to open file have failed, return the last error.
- log.Debugf("Failed to open file, path: %q, err: %v", path, err)
+ log.Debugf("Failed to open file, path: %q, err: %v", pathDebug, err)
return nil, false, extractErrno(err)
}
-func checkSupportedFileType(stat syscall.Stat_t, permitSocket bool) error {
- switch stat.Mode & syscall.S_IFMT {
- case syscall.S_IFREG, syscall.S_IFDIR, syscall.S_IFLNK:
+func checkSupportedFileType(stat unix.Stat_t, permitSocket bool) error {
+ switch stat.Mode & unix.S_IFMT {
+ case unix.S_IFREG, unix.S_IFDIR, unix.S_IFLNK:
return nil
- case syscall.S_IFSOCK:
+ case unix.S_IFSOCK:
if !permitSocket {
- return syscall.EPERM
+ return unix.EPERM
}
return nil
default:
- return syscall.EPERM
+ return unix.EPERM
}
}
-func newLocalFile(a *attachPoint, file *fd.FD, path string, readable bool, stat syscall.Stat_t) (*localFile, error) {
+func newLocalFile(a *attachPoint, file *fd.FD, path string, readable bool, stat unix.Stat_t) (*localFile, error) {
if err := checkSupportedFileType(stat, a.conf.HostUDS); err != nil {
return nil, err
}
@@ -307,7 +321,7 @@ func newLocalFile(a *attachPoint, file *fd.FD, path string, readable bool, stat
hostPath: path,
file: file,
mode: invalidMode,
- fileType: stat.Mode & syscall.S_IFMT,
+ fileType: stat.Mode & unix.S_IFMT,
qid: a.makeQID(stat),
controlReadable: readable,
}, nil
@@ -317,7 +331,7 @@ func newLocalFile(a *attachPoint, file *fd.FD, path string, readable bool, stat
// non-blocking. If anything fails, returns nil. It's better to have a file
// without host FD, than to fail the operation.
func newFDMaybe(file *fd.FD) *fd.FD {
- dupFD, err := syscall.Dup(file.FD())
+ dupFD, err := unix.Dup(file.FD())
// Technically, the runtime may call the finalizer on file as soon as
// FD() returns.
runtime.KeepAlive(file)
@@ -327,31 +341,23 @@ func newFDMaybe(file *fd.FD) *fd.FD {
dup := fd.New(dupFD)
// fd is blocking; non-blocking is required.
- if err := syscall.SetNonblock(dup.FD(), true); err != nil {
+ if err := unix.SetNonblock(dup.FD(), true); err != nil {
_ = dup.Close()
return nil
}
return dup
}
-func fstat(fd int) (syscall.Stat_t, error) {
- var stat syscall.Stat_t
- if err := syscall.Fstat(fd, &stat); err != nil {
- return syscall.Stat_t{}, err
- }
- return stat, nil
-}
-
-func stat(path string) (syscall.Stat_t, error) {
- var stat syscall.Stat_t
- if err := syscall.Stat(path, &stat); err != nil {
- return syscall.Stat_t{}, err
+func fstat(fd int) (unix.Stat_t, error) {
+ var stat unix.Stat_t
+ if err := unix.Fstat(fd, &stat); err != nil {
+ return unix.Stat_t{}, err
}
return stat, nil
}
func fchown(fd int, uid p9.UID, gid p9.GID) error {
- return syscall.Fchownat(fd, "", int(uid), int(gid), linux.AT_EMPTY_PATH|unix.AT_SYMLINK_NOFOLLOW)
+ return unix.Fchownat(fd, "", int(uid), int(gid), linux.AT_EMPTY_PATH|unix.AT_SYMLINK_NOFOLLOW)
}
// Open implements p9.File.
@@ -377,7 +383,7 @@ func (l *localFile) Open(flags p9.OpenFlags) (*fd.FD, p9.QID, uint32, error) {
// name_to_handle_at and open_by_handle_at aren't supported by overlay2.
log.Debugf("Open reopening file, flags: %v, %q", flags, l.hostPath)
var err error
- osFlags := flags.OSFlags() & (syscall.O_ACCMODE | allowedOpenFlags)
+ osFlags := flags.OSFlags() & (unix.O_ACCMODE | allowedOpenFlags)
newFile, err = reopenProcFd(l.file, openFlags|osFlags)
if err != nil {
return nil, p9.QID{}, 0, extractErrno(err)
@@ -385,7 +391,7 @@ func (l *localFile) Open(flags p9.OpenFlags) (*fd.FD, p9.QID, uint32, error) {
}
var fd *fd.FD
- if l.fileType == syscall.S_IFREG {
+ if l.fileType == unix.S_IFREG {
// Donate FD for regular files only.
fd = newFDMaybe(newFile)
}
@@ -408,7 +414,7 @@ func (l *localFile) Create(name string, p9Flags p9.OpenFlags, perm p9.FileMode,
}
// Set file creation flags, plus allowed open flags from caller.
- osFlags := openFlags | syscall.O_CREAT | syscall.O_EXCL
+ osFlags := openFlags | unix.O_CREAT | unix.O_EXCL
osFlags |= p9Flags.OSFlags() & allowedOpenFlags
// 'file' may be used for other operations (e.g. Walk), so read access is
@@ -416,9 +422,9 @@ func (l *localFile) Create(name string, p9Flags p9.OpenFlags, perm p9.FileMode,
// than needed for each particular case.
mode := p9Flags & p9.OpenFlagsModeMask
if mode == p9.WriteOnly {
- osFlags |= syscall.O_RDWR
+ osFlags |= unix.O_RDWR
} else {
- osFlags |= mode.OSFlags() & unix.O_ACCMODE
+ osFlags |= mode.OSFlags()
}
child, err := fd.OpenAt(l.file, name, osFlags, uint32(perm.Permissions()))
@@ -428,7 +434,7 @@ func (l *localFile) Create(name string, p9Flags p9.OpenFlags, perm p9.FileMode,
cu := cleanup.Make(func() {
_ = child.Close()
// Best effort attempt to remove the file in case of failure.
- if err := syscall.Unlinkat(l.file.FD(), name); err != nil {
+ if err := unix.Unlinkat(l.file.FD(), name, 0); err != nil {
log.Warningf("error unlinking file %q after failure: %v", path.Join(l.hostPath, name), err)
}
})
@@ -447,7 +453,7 @@ func (l *localFile) Create(name string, p9Flags p9.OpenFlags, perm p9.FileMode,
hostPath: path.Join(l.hostPath, name),
file: child,
mode: mode,
- fileType: syscall.S_IFREG,
+ fileType: unix.S_IFREG,
qid: l.attachPoint.makeQID(stat),
}
@@ -461,7 +467,7 @@ func (l *localFile) Mkdir(name string, perm p9.FileMode, uid p9.UID, gid p9.GID)
return p9.QID{}, err
}
- if err := syscall.Mkdirat(l.file.FD(), name, uint32(perm.Permissions())); err != nil {
+ if err := unix.Mkdirat(l.file.FD(), name, uint32(perm.Permissions())); err != nil {
return p9.QID{}, extractErrno(err)
}
cu := cleanup.Make(func() {
@@ -473,7 +479,7 @@ func (l *localFile) Mkdir(name string, perm p9.FileMode, uid p9.UID, gid p9.GID)
defer cu.Clean()
// Open directory to change ownership and stat it.
- flags := syscall.O_DIRECTORY | syscall.O_RDONLY | openFlags
+ flags := unix.O_DIRECTORY | unix.O_RDONLY | openFlags
f, err := fd.OpenAt(l.file, name, flags, 0)
if err != nil {
return p9.QID{}, extractErrno(err)
@@ -508,20 +514,20 @@ func (l *localFile) WalkGetAttr(names []string) ([]p9.QID, p9.File, p9.AttrMask,
return qids, file, mask, attr, nil
}
-func (l *localFile) walk(names []string) ([]p9.QID, p9.File, syscall.Stat_t, error) {
+func (l *localFile) walk(names []string) ([]p9.QID, p9.File, unix.Stat_t, error) {
// Duplicate current file if 'names' is empty.
if len(names) == 0 {
newFile, readable, err := openAnyFile(l.hostPath, func(mode int) (*fd.FD, error) {
return reopenProcFd(l.file, openFlags|mode)
})
if err != nil {
- return nil, nil, syscall.Stat_t{}, extractErrno(err)
+ return nil, nil, unix.Stat_t{}, extractErrno(err)
}
stat, err := fstat(newFile.FD())
if err != nil {
_ = newFile.Close()
- return nil, nil, syscall.Stat_t{}, extractErrno(err)
+ return nil, nil, unix.Stat_t{}, extractErrno(err)
}
c := &localFile{
@@ -537,7 +543,7 @@ func (l *localFile) walk(names []string) ([]p9.QID, p9.File, syscall.Stat_t, err
}
var qids []p9.QID
- var lastStat syscall.Stat_t
+ var lastStat unix.Stat_t
last := l
for _, name := range names {
f, path, readable, err := openAnyFileFromParent(last, name)
@@ -545,17 +551,17 @@ func (l *localFile) walk(names []string) ([]p9.QID, p9.File, syscall.Stat_t, err
_ = last.Close()
}
if err != nil {
- return nil, nil, syscall.Stat_t{}, extractErrno(err)
+ return nil, nil, unix.Stat_t{}, extractErrno(err)
}
lastStat, err = fstat(f.FD())
if err != nil {
_ = f.Close()
- return nil, nil, syscall.Stat_t{}, extractErrno(err)
+ return nil, nil, unix.Stat_t{}, extractErrno(err)
}
c, err := newLocalFile(last.attachPoint, f, path, readable, lastStat)
if err != nil {
_ = f.Close()
- return nil, nil, syscall.Stat_t{}, extractErrno(err)
+ return nil, nil, unix.Stat_t{}, extractErrno(err)
}
qids = append(qids, c.qid)
@@ -566,8 +572,8 @@ func (l *localFile) walk(names []string) ([]p9.QID, p9.File, syscall.Stat_t, err
// StatFS implements p9.File.
func (l *localFile) StatFS() (p9.FSStat, error) {
- var s syscall.Statfs_t
- if err := syscall.Fstatfs(l.file.FD(), &s); err != nil {
+ var s unix.Statfs_t
+ if err := unix.Fstatfs(l.file.FD(), &s); err != nil {
return p9.FSStat{}, extractErrno(err)
}
@@ -587,9 +593,9 @@ func (l *localFile) StatFS() (p9.FSStat, error) {
// FSync implements p9.File.
func (l *localFile) FSync() error {
if !l.isOpen() {
- return syscall.EBADF
+ return unix.EBADF
}
- if err := syscall.Fsync(l.file.FD()); err != nil {
+ if err := unix.Fsync(l.file.FD()); err != nil {
return extractErrno(err)
}
return nil
@@ -605,7 +611,7 @@ func (l *localFile) GetAttr(_ p9.AttrMask) (p9.QID, p9.AttrMask, p9.Attr, error)
return l.qid, mask, attr, nil
}
-func (l *localFile) fillAttr(stat syscall.Stat_t) (p9.AttrMask, p9.Attr) {
+func (l *localFile) fillAttr(stat unix.Stat_t) (p9.AttrMask, p9.Attr) {
attr := p9.Attr{
Mode: p9.FileMode(stat.Mode),
UID: p9.UID(stat.Uid),
@@ -665,13 +671,13 @@ func (l *localFile) SetAttr(valid p9.SetAttrMask, attr p9.SetAttr) error {
// consistent result that is not attribute dependent.
if !valid.IsSubsetOf(allowed) {
log.Warningf("SetAttr() failed for %q, mask: %v", l.hostPath, valid)
- return syscall.EPERM
+ return unix.EPERM
}
// Check if it's possible to use cached file, or if another one needs to be
// opened for write.
f := l.file
- if l.fileType == syscall.S_IFREG && l.mode != p9.WriteOnly && l.mode != p9.ReadWrite {
+ if l.fileType == unix.S_IFREG && l.mode != p9.WriteOnly && l.mode != p9.ReadWrite {
var err error
f, err = reopenProcFd(l.file, openFlags|os.O_WRONLY)
if err != nil {
@@ -692,21 +698,21 @@ func (l *localFile) SetAttr(valid p9.SetAttrMask, attr p9.SetAttr) error {
// over another.
var err error
if valid.Permissions {
- if cerr := syscall.Fchmod(f.FD(), uint32(attr.Permissions)); cerr != nil {
+ if cerr := unix.Fchmod(f.FD(), uint32(attr.Permissions)); cerr != nil {
log.Debugf("SetAttr fchmod failed %q, err: %v", l.hostPath, cerr)
err = extractErrno(cerr)
}
}
if valid.Size {
- if terr := syscall.Ftruncate(f.FD(), int64(attr.Size)); terr != nil {
+ if terr := unix.Ftruncate(f.FD(), int64(attr.Size)); terr != nil {
log.Debugf("SetAttr ftruncate failed %q, err: %v", l.hostPath, terr)
err = extractErrno(terr)
}
}
if valid.ATime || valid.MTime {
- utimes := [2]syscall.Timespec{
+ utimes := [2]unix.Timespec{
{Sec: 0, Nsec: linux.UTIME_OMIT},
{Sec: 0, Nsec: linux.UTIME_OMIT},
}
@@ -727,15 +733,15 @@ func (l *localFile) SetAttr(valid p9.SetAttrMask, attr p9.SetAttr) error {
}
}
- if l.fileType == syscall.S_IFLNK {
+ if l.fileType == unix.S_IFLNK {
// utimensat operates different that other syscalls. To operate on a
// symlink it *requires* AT_SYMLINK_NOFOLLOW with dirFD and a non-empty
// name.
- parent, err := syscall.Open(path.Dir(l.hostPath), openFlags|unix.O_PATH, 0)
+ parent, err := unix.Open(path.Dir(l.hostPath), openFlags|unix.O_PATH, 0)
if err != nil {
return extractErrno(err)
}
- defer syscall.Close(parent)
+ defer unix.Close(parent)
if terr := utimensat(parent, path.Base(l.hostPath), utimes, linux.AT_SYMLINK_NOFOLLOW); terr != nil {
log.Debugf("SetAttr utimens failed %q, err: %v", l.hostPath, terr)
@@ -760,7 +766,7 @@ func (l *localFile) SetAttr(valid p9.SetAttrMask, attr p9.SetAttr) error {
if valid.GID {
gid = int(attr.GID)
}
- if oerr := syscall.Fchownat(f.FD(), "", uid, gid, linux.AT_EMPTY_PATH|linux.AT_SYMLINK_NOFOLLOW); oerr != nil {
+ if oerr := unix.Fchownat(f.FD(), "", uid, gid, linux.AT_EMPTY_PATH|linux.AT_SYMLINK_NOFOLLOW); oerr != nil {
log.Debugf("SetAttr fchownat failed %q, err: %v", l.hostPath, oerr)
err = extractErrno(oerr)
}
@@ -770,28 +776,28 @@ func (l *localFile) SetAttr(valid p9.SetAttrMask, attr p9.SetAttr) error {
}
func (*localFile) GetXattr(string, uint64) (string, error) {
- return "", syscall.EOPNOTSUPP
+ return "", unix.EOPNOTSUPP
}
func (*localFile) SetXattr(string, string, uint32) error {
- return syscall.EOPNOTSUPP
+ return unix.EOPNOTSUPP
}
func (*localFile) ListXattr(uint64) (map[string]struct{}, error) {
- return nil, syscall.EOPNOTSUPP
+ return nil, unix.EOPNOTSUPP
}
func (*localFile) RemoveXattr(string) error {
- return syscall.EOPNOTSUPP
+ return unix.EOPNOTSUPP
}
// Allocate implements p9.File.
func (l *localFile) Allocate(mode p9.AllocateMode, offset, length uint64) error {
if !l.isOpen() {
- return syscall.EBADF
+ return unix.EBADF
}
- if err := syscall.Fallocate(l.file.FD(), mode.ToLinux(), int64(offset), int64(length)); err != nil {
+ if err := unix.Fallocate(l.file.FD(), mode.ToLinux(), int64(offset), int64(length)); err != nil {
return extractErrno(err)
}
return nil
@@ -818,10 +824,10 @@ func (l *localFile) RenameAt(oldName string, directory p9.File, newName string)
// ReadAt implements p9.File.
func (l *localFile) ReadAt(p []byte, offset uint64) (int, error) {
if l.mode != p9.ReadOnly && l.mode != p9.ReadWrite {
- return 0, syscall.EBADF
+ return 0, unix.EBADF
}
if !l.isOpen() {
- return 0, syscall.EBADF
+ return 0, unix.EBADF
}
r, err := l.file.ReadAt(p, int64(offset))
@@ -836,10 +842,10 @@ func (l *localFile) ReadAt(p []byte, offset uint64) (int, error) {
// WriteAt implements p9.File.
func (l *localFile) WriteAt(p []byte, offset uint64) (int, error) {
if l.mode != p9.WriteOnly && l.mode != p9.ReadWrite {
- return 0, syscall.EBADF
+ return 0, unix.EBADF
}
if !l.isOpen() {
- return 0, syscall.EBADF
+ return 0, unix.EBADF
}
w, err := l.file.WriteAt(p, int64(offset))
@@ -860,7 +866,7 @@ func (l *localFile) Symlink(target, newName string, uid p9.UID, gid p9.GID) (p9.
}
cu := cleanup.Make(func() {
// Best effort attempt to remove the symlink in case of failure.
- if err := syscall.Unlinkat(l.file.FD(), newName); err != nil {
+ if err := unix.Unlinkat(l.file.FD(), newName, 0); err != nil {
log.Warningf("error unlinking file %q after failure: %v", path.Join(l.hostPath, newName), err)
}
})
@@ -899,34 +905,46 @@ func (l *localFile) Link(target p9.File, newName string) error {
}
// Mknod implements p9.File.
-func (l *localFile) Mknod(name string, mode p9.FileMode, _ uint32, _ uint32, _ p9.UID, _ p9.GID) (p9.QID, error) {
+func (l *localFile) Mknod(name string, mode p9.FileMode, _ uint32, _ uint32, uid p9.UID, gid p9.GID) (p9.QID, error) {
if err := l.checkROMount(); err != nil {
return p9.QID{}, err
}
- hostPath := path.Join(l.hostPath, name)
-
- // Return EEXIST if the file already exists.
- if _, err := stat(hostPath); err == nil {
- return p9.QID{}, syscall.EEXIST
- }
-
// From mknod(2) man page:
// "EPERM: [...] if the filesystem containing pathname does not support
// the type of node requested."
if mode.FileType() != p9.ModeRegular {
- return p9.QID{}, syscall.EPERM
+ return p9.QID{}, unix.EPERM
}
// Allow Mknod to create regular files.
- if err := syscall.Mknod(hostPath, uint32(mode), 0); err != nil {
+ if err := unix.Mknodat(l.file.FD(), name, uint32(mode), 0); err != nil {
return p9.QID{}, err
}
+ cu := cleanup.Make(func() {
+ // Best effort attempt to remove the file in case of failure.
+ if err := unix.Unlinkat(l.file.FD(), name, 0); err != nil {
+ log.Warningf("error unlinking file %q after failure: %v", path.Join(l.hostPath, name), err)
+ }
+ })
+ defer cu.Clean()
- stat, err := stat(hostPath)
+ // Open file to change ownership and stat it.
+ child, err := fd.OpenAt(l.file, name, unix.O_PATH|openFlags, 0)
if err != nil {
return p9.QID{}, extractErrno(err)
}
+ defer child.Close()
+
+ if err := fchown(child.FD(), uid, gid); err != nil {
+ return p9.QID{}, extractErrno(err)
+ }
+ stat, err := fstat(child.FD())
+ if err != nil {
+ return p9.QID{}, extractErrno(err)
+ }
+
+ cu.Release()
return l.attachPoint.makeQID(stat), nil
}
@@ -945,10 +963,10 @@ func (l *localFile) UnlinkAt(name string, flags uint32) error {
// Readdir implements p9.File.
func (l *localFile) Readdir(offset uint64, count uint32) ([]p9.Dirent, error) {
if l.mode != p9.ReadOnly && l.mode != p9.ReadWrite {
- return nil, syscall.EBADF
+ return nil, unix.EBADF
}
if !l.isOpen() {
- return nil, syscall.EBADF
+ return nil, unix.EBADF
}
// Readdirnames is a cursor over directories, so seek back to 0 to ensure it's
@@ -965,7 +983,7 @@ func (l *localFile) Readdir(offset uint64, count uint32) ([]p9.Dirent, error) {
// which causes the directory stream to resynchronize with the directory's
// current contents).
if l.lastDirentOffset != offset || offset == 0 {
- if _, err := syscall.Seek(l.file.FD(), 0, 0); err != nil {
+ if _, err := unix.Seek(l.file.FD(), 0, 0); err != nil {
return nil, extractErrno(err)
}
skip = offset
@@ -998,7 +1016,7 @@ func (l *localFile) readDirent(f int, offset uint64, count uint32, skip uint64)
end := offset + uint64(count)
for offset < end {
- dirSize, err := syscall.ReadDirent(f, direntsBuf)
+ dirSize, err := unix.ReadDirent(f, direntsBuf)
if err != nil {
return dirents, err
}
@@ -1007,7 +1025,7 @@ func (l *localFile) readDirent(f int, offset uint64, count uint32, skip uint64)
}
names := names[:0]
- _, _, names = syscall.ParseDirent(direntsBuf[:dirSize], -1, names)
+ _, _, names = unix.ParseDirent(direntsBuf[:dirSize], -1, names)
// Skip over entries that the caller is not interested in.
if skip > 0 {
@@ -1052,7 +1070,7 @@ func (l *localFile) Readlink() (string, error) {
return string(b[:n]), nil
}
}
- return "", syscall.ENOMEM
+ return "", unix.ENOMEM
}
// Flush implements p9.File.
@@ -1063,7 +1081,7 @@ func (l *localFile) Flush() error {
// Connect implements p9.File.
func (l *localFile) Connect(flags p9.ConnectFlags) (*fd.FD, error) {
if !l.attachPoint.conf.HostUDS {
- return nil, syscall.ECONNREFUSED
+ return nil, unix.ECONNREFUSED
}
// TODO(gvisor.dev/issue/1003): Due to different app vs replacement
@@ -1071,34 +1089,34 @@ func (l *localFile) Connect(flags p9.ConnectFlags) (*fd.FD, error) {
// fit f.path in our sockaddr. We'd need to redirect through a shorter
// path in order to actually connect to this socket.
if len(l.hostPath) > linux.UnixPathMax {
- return nil, syscall.ECONNREFUSED
+ return nil, unix.ECONNREFUSED
}
var stype int
switch flags {
case p9.StreamSocket:
- stype = syscall.SOCK_STREAM
+ stype = unix.SOCK_STREAM
case p9.DgramSocket:
- stype = syscall.SOCK_DGRAM
+ stype = unix.SOCK_DGRAM
case p9.SeqpacketSocket:
- stype = syscall.SOCK_SEQPACKET
+ stype = unix.SOCK_SEQPACKET
default:
- return nil, syscall.ENXIO
+ return nil, unix.ENXIO
}
- f, err := syscall.Socket(syscall.AF_UNIX, stype, 0)
+ f, err := unix.Socket(unix.AF_UNIX, stype, 0)
if err != nil {
return nil, err
}
- if err := syscall.SetNonblock(f, true); err != nil {
- _ = syscall.Close(f)
+ if err := unix.SetNonblock(f, true); err != nil {
+ _ = unix.Close(f)
return nil, err
}
- sa := syscall.SockaddrUnix{Name: l.hostPath}
- if err := syscall.Connect(f, &sa); err != nil {
- _ = syscall.Close(f)
+ sa := unix.SockaddrUnix{Name: l.hostPath}
+ if err := unix.Connect(f, &sa); err != nil {
+ _ = unix.Close(f)
return nil, err
}
@@ -1123,7 +1141,7 @@ func (l *localFile) Renamed(newDir p9.File, newName string) {
}
// extractErrno tries to determine the errno.
-func extractErrno(err error) syscall.Errno {
+func extractErrno(err error) unix.Errno {
if err == nil {
// This should never happen. The likely result will be that
// some user gets the frustrating "error: SUCCESS" message.
@@ -1133,18 +1151,18 @@ func extractErrno(err error) syscall.Errno {
switch err {
case os.ErrNotExist:
- return syscall.ENOENT
+ return unix.ENOENT
case os.ErrExist:
- return syscall.EEXIST
+ return unix.EEXIST
case os.ErrPermission:
- return syscall.EACCES
+ return unix.EACCES
case os.ErrInvalid:
- return syscall.EINVAL
+ return unix.EINVAL
}
// See if it's an errno or a common wrapped error.
switch e := err.(type) {
- case syscall.Errno:
+ case unix.Errno:
return e
case *os.PathError:
return extractErrno(e.Err)
@@ -1156,7 +1174,7 @@ func extractErrno(err error) syscall.Errno {
// Fall back to EIO.
log.Debugf("Unknown error: %v, defaulting to EIO", err)
- return syscall.EIO
+ return unix.EIO
}
func (l *localFile) checkROMount() error {
@@ -1164,7 +1182,7 @@ func (l *localFile) checkROMount() error {
if conf.PanicOnWrite {
panic("attempt to write to RO mount")
}
- return syscall.EROFS
+ return unix.EROFS
}
return nil
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-19 06:40:21 +0000