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-rw-r--r--internal/fusefrontend/xattr.go101
-rw-r--r--internal/fusefrontend/xattr_darwin.go78
-rw-r--r--internal/fusefrontend/xattr_linux.go105
3 files changed, 75 insertions, 209 deletions
diff --git a/internal/fusefrontend/xattr.go b/internal/fusefrontend/xattr.go
index 816754c..045f963 100644
--- a/internal/fusefrontend/xattr.go
+++ b/internal/fusefrontend/xattr.go
@@ -1,15 +1,15 @@
// Package fusefrontend interfaces directly with the go-fuse library.
package fusefrontend
-// FUSE operations on paths
-
import (
"strings"
"syscall"
+ "golang.org/x/sys/unix"
+
"github.com/hanwen/go-fuse/fuse"
- "github.com/pkg/xattr"
+ "github.com/rfjakob/gocryptfs/internal/syscallcompat"
"github.com/rfjakob/gocryptfs/internal/tlog"
)
@@ -25,9 +25,7 @@ var xattrStorePrefix = "user.gocryptfs."
// GetXAttr - FUSE call. Reads the value of extended attribute "attr".
//
-// This function is symlink-safe on Linux.
-// Darwin does not have fgetxattr(2) nor /proc/self/fd. How to implement this
-// on Darwin in a symlink-safe way?
+// This function is symlink-safe through Fgetxattr.
func (fs *FS) GetXAttr(relPath string, attr string, context *fuse.Context) ([]byte, fuse.Status) {
if fs.isFiltered(relPath) {
return nil, fuse.EPERM
@@ -35,11 +33,20 @@ func (fs *FS) GetXAttr(relPath string, attr string, context *fuse.Context) ([]by
if disallowedXAttrName(attr) {
return nil, _EOPNOTSUPP
}
- cAttr := fs.encryptXattrName(attr)
- cData, status := fs.getXattr(relPath, cAttr, context)
+
+ file, fd, status := fs.getFileFd(relPath, context)
if !status.Ok() {
return nil, status
}
+ defer file.Release()
+
+ cAttr := fs.encryptXattrName(attr)
+
+ cData, err := syscallcompat.Fgetxattr(fd, cAttr)
+ if err != nil {
+ return nil, fuse.ToStatus(err)
+ }
+
data, err := fs.decryptXattrValue(cData)
if err != nil {
tlog.Warn.Printf("GetXAttr: %v", err)
@@ -50,9 +57,7 @@ func (fs *FS) GetXAttr(relPath string, attr string, context *fuse.Context) ([]by
// SetXAttr - FUSE call. Set extended attribute.
//
-// This function is symlink-safe on Linux.
-// Darwin does not have fsetxattr(2) nor /proc/self/fd. How to implement this
-// on Darwin in a symlink-safe way?
+// This function is symlink-safe through Fsetxattr.
func (fs *FS) SetXAttr(relPath string, attr string, data []byte, flags int, context *fuse.Context) fuse.Status {
if fs.isFiltered(relPath) {
return fuse.EPERM
@@ -60,17 +65,27 @@ func (fs *FS) SetXAttr(relPath string, attr string, data []byte, flags int, cont
if disallowedXAttrName(attr) {
return _EOPNOTSUPP
}
+
+ file, fd, status := fs.getFileFd(relPath, context)
+ if !status.Ok() {
+ return status
+ }
+ defer file.Release()
+
flags = filterXattrSetFlags(flags)
cAttr := fs.encryptXattrName(attr)
cData := fs.encryptXattrValue(data)
- return fs.setXattr(relPath, cAttr, cData, flags, context)
+
+ err := unix.Fsetxattr(fd, cAttr, cData, flags)
+ if err != nil {
+ return fuse.ToStatus(err)
+ }
+ return fuse.OK
}
// RemoveXAttr - FUSE call.
//
-// This function is symlink-safe on Linux.
-// Darwin does not have fremovexattr(2) nor /proc/self/fd. How to implement this
-// on Darwin in a symlink-safe way?
+// This function is symlink-safe through Fremovexattr.
func (fs *FS) RemoveXAttr(relPath string, attr string, context *fuse.Context) fuse.Status {
if fs.isFiltered(relPath) {
return fuse.EPERM
@@ -78,23 +93,45 @@ func (fs *FS) RemoveXAttr(relPath string, attr string, context *fuse.Context) fu
if disallowedXAttrName(attr) {
return _EOPNOTSUPP
}
+
+ file, fd, status := fs.getFileFd(relPath, context)
+ if !status.Ok() {
+ return status
+ }
+ defer file.Release()
+
cAttr := fs.encryptXattrName(attr)
- return fs.removeXAttr(relPath, cAttr, context)
+ err := unix.Fremovexattr(fd, cAttr)
+ if err != nil {
+ return fuse.ToStatus(err)
+ }
+ return fuse.OK
}
// ListXAttr - FUSE call. Lists extended attributes on the file at "relPath".
//
-// This function is symlink-safe on Linux.
-// Darwin does not have flistxattr(2) nor /proc/self/fd. How to implement this
-// on Darwin in a symlink-safe way?
+// This function is symlink-safe through Flistxattr.
func (fs *FS) ListXAttr(relPath string, context *fuse.Context) ([]string, fuse.Status) {
if fs.isFiltered(relPath) {
return nil, fuse.EPERM
}
- cNames, status := fs.listXAttr(relPath, context)
+
+ file, fd, status := fs.getFileFd(relPath, context)
+ // On a symlink, getFileFd fails with ELOOP. Let's pretend there
+ // can be no xattrs on symlinks, and always return an empty result.
+ if status == fuse.Status(syscall.ELOOP) {
+ return nil, fuse.OK
+ }
if !status.Ok() {
return nil, status
}
+ defer file.Release()
+
+ cNames, err := syscallcompat.Flistxattr(fd)
+ if err != nil {
+ return nil, fuse.ToStatus(err)
+ }
+
names := make([]string, 0, len(cNames))
for _, curName := range cNames {
if !strings.HasPrefix(curName, xattrStorePrefix) {
@@ -163,16 +200,22 @@ func (fs *FS) decryptXattrValue(cData []byte) (data []byte, err error) {
return fs.contentEnc.DecryptBlock([]byte(cData), 0, nil)
}
-// unpackXattrErr unpacks an error value that we got from xattr.LGet/LSet/etc
-// and converts it to a fuse status. If err == nil, it returns fuse.OK.
-func unpackXattrErr(err error) fuse.Status {
- if err == nil {
- return fuse.OK
+// getFileFd calls fs.Open() on relative plaintext path "relPath" and returns
+// the resulting fusefrontend.*File along with the underlying fd. The caller
+// MUST call file.Release() when done with the file. The O_NONBLOCK flag is
+// used to not block on FIFOs.
+//
+// Used by xattrGet() and friends.
+func (fs *FS) getFileFd(relPath string, context *fuse.Context) (*File, int, fuse.Status) {
+ fuseFile, status := fs.Open(relPath, syscall.O_RDONLY|syscall.O_NONBLOCK, context)
+ if !status.Ok() {
+ return nil, -1, status
}
- err2, ok := err.(*xattr.Error)
+ file, ok := fuseFile.(*File)
if !ok {
- tlog.Warn.Printf("unpackXattrErr: cannot unpack err=%v", err)
- return fuse.EIO
+ tlog.Warn.Printf("BUG: xattrGet: cast to *File failed")
+ fuseFile.Release()
+ return nil, -1, fuse.EIO
}
- return fuse.ToStatus(err2.Err)
+ return file, file.intFd(), fuse.OK
}
diff --git a/internal/fusefrontend/xattr_darwin.go b/internal/fusefrontend/xattr_darwin.go
index c756486..8760480 100644
--- a/internal/fusefrontend/xattr_darwin.go
+++ b/internal/fusefrontend/xattr_darwin.go
@@ -3,86 +3,14 @@
// Package fusefrontend interfaces directly with the go-fuse library.
package fusefrontend
-import (
- "path/filepath"
-
- "github.com/pkg/xattr"
-
- "github.com/hanwen/go-fuse/fuse"
-
- "github.com/rfjakob/gocryptfs/internal/tlog"
-)
-
func disallowedXAttrName(attr string) bool {
return false
}
// On Darwin it is needed to unset XATTR_NOSECURITY 0x0008
func filterXattrSetFlags(flags int) int {
- return flags &^ xattr.XATTR_NOSECURITY
-}
-
-// This function is NOT symlink-safe because Darwin lacks
-// both fgetxattr() and /proc/self/fd.
-func (fs *FS) getXattr(relPath string, cAttr string, context *fuse.Context) ([]byte, fuse.Status) {
- cPath, err := fs.getBackingPath(relPath)
- if err != nil {
- return nil, fuse.ToStatus(err)
- }
- cData, err := xattr.LGet(cPath, cAttr)
- if err != nil {
- return nil, unpackXattrErr(err)
- }
- return cData, fuse.OK
-}
-
-// This function is NOT symlink-safe because Darwin lacks
-// both fsetxattr() and /proc/self/fd.
-func (fs *FS) setXattr(relPath string, cAttr string, cData []byte, flags int, context *fuse.Context) fuse.Status {
- cPath, err := fs.getBackingPath(relPath)
- if err != nil {
- return fuse.ToStatus(err)
- }
- err = xattr.LSetWithFlags(cPath, cAttr, cData, flags)
- return unpackXattrErr(err)
-}
-
-// This function is NOT symlink-safe because Darwin lacks
-// both fremovexattr() and /proc/self/fd.
-func (fs *FS) removeXAttr(relPath string, cAttr string, context *fuse.Context) fuse.Status {
- cPath, err := fs.getBackingPath(relPath)
- if err != nil {
- return fuse.ToStatus(err)
- }
- err = xattr.LRemove(cPath, cAttr)
- return unpackXattrErr(err)
-}
-
-// This function is NOT symlink-safe because Darwin lacks
-// both flistxattr() and /proc/self/fd.
-func (fs *FS) listXAttr(relPath string, context *fuse.Context) ([]string, fuse.Status) {
- cPath, err := fs.getBackingPath(relPath)
- if err != nil {
- return nil, fuse.ToStatus(err)
- }
- cNames, err := xattr.LList(cPath)
- if err != nil {
- return nil, unpackXattrErr(err)
- }
- return cNames, fuse.OK
-}
+ // See https://opensource.apple.com/source/xnu/xnu-1504.15.3/bsd/sys/xattr.h.auto.html
+ const XATTR_NOSECURITY = 0x0008
-// getBackingPath - get the absolute encrypted path of the backing file
-// from the relative plaintext path "relPath"
-//
-// This function is NOT symlink-safe. Darwin needs it because it lacks
-// fgetxattr(2) and friends.
-func (fs *FS) getBackingPath(relPath string) (string, error) {
- cPath, err := fs.encryptPath(relPath)
- if err != nil {
- return "", err
- }
- cAbsPath := filepath.Join(fs.args.Cipherdir, cPath)
- tlog.Debug.Printf("getBackingPath: %s + %s -> %s", fs.args.Cipherdir, relPath, cAbsPath)
- return cAbsPath, nil
+ return flags &^ XATTR_NOSECURITY
}
diff --git a/internal/fusefrontend/xattr_linux.go b/internal/fusefrontend/xattr_linux.go
index a96a147..fd3b7e5 100644
--- a/internal/fusefrontend/xattr_linux.go
+++ b/internal/fusefrontend/xattr_linux.go
@@ -4,15 +4,7 @@
package fusefrontend
import (
- "fmt"
"strings"
- "syscall"
-
- "github.com/hanwen/go-fuse/fuse"
-
- "github.com/pkg/xattr"
-
- "github.com/rfjakob/gocryptfs/internal/tlog"
)
// Only allow the "user" namespace, block "trusted" and "security", as
@@ -27,100 +19,3 @@ func disallowedXAttrName(attr string) bool {
func filterXattrSetFlags(flags int) int {
return flags
}
-
-// procFd returns the path to file descriptor "fd" in /proc/self/fd.
-func procFd(fd int) string {
- return fmt.Sprintf("/proc/self/fd/%d", fd)
-}
-
-// getFileFd calls fs.Open() on relative plaintext path "relPath" and returns
-// the resulting fusefrontend.*File along with the underlying fd. The caller
-// MUST call file.Release() when done with the file. The O_NONBLOCK flag is
-// used to not block on FIFOs.
-//
-// Used by xattrGet() and friends.
-func (fs *FS) getFileFd(relPath string, context *fuse.Context) (*File, int, fuse.Status) {
- fuseFile, status := fs.Open(relPath, syscall.O_RDONLY|syscall.O_NONBLOCK, context)
- if !status.Ok() {
- return nil, -1, status
- }
- file, ok := fuseFile.(*File)
- if !ok {
- tlog.Warn.Printf("BUG: xattrGet: cast to *File failed")
- fuseFile.Release()
- return nil, -1, fuse.EIO
- }
- return file, file.intFd(), fuse.OK
-}
-
-// getXattr - read encrypted xattr name "cAttr" from relative
-// plaintext path "relPath". Returns the encrypted xattr value.
-//
-// This function is symlink-safe by using /proc/self/fd.
-func (fs *FS) getXattr(relPath string, cAttr string, context *fuse.Context) ([]byte, fuse.Status) {
- file, fd, status := fs.getFileFd(relPath, context)
- if !status.Ok() {
- return nil, status
- }
- defer file.Release()
-
- cData, err := xattr.Get(procFd(fd), cAttr)
- if err != nil {
- return nil, unpackXattrErr(err)
- }
- return cData, fuse.OK
-}
-
-// setXattr - set encrypted xattr name "cAttr" to value "cData" on plaintext
-// path "relPath".
-//
-// This function is symlink-safe by using /proc/self/fd.
-func (fs *FS) setXattr(relPath string, cAttr string, cData []byte, flags int, context *fuse.Context) fuse.Status {
- file, fd, status := fs.getFileFd(relPath, context)
- if !status.Ok() {
- return status
- }
- defer file.Release()
-
- err := xattr.SetWithFlags(procFd(fd), cAttr, cData, flags)
- return unpackXattrErr(err)
-}
-
-// removeXAttr - remove encrypted xattr name "cAttr" from
-// plaintext path "relPath".
-//
-// This function is symlink-safe on Linux by using /proc/self/fd.
-func (fs *FS) removeXAttr(relPath string, cAttr string, context *fuse.Context) fuse.Status {
- file, fd, status := fs.getFileFd(relPath, context)
- if !status.Ok() {
- return status
- }
- defer file.Release()
-
- err := xattr.Remove(procFd(fd), cAttr)
- return unpackXattrErr(err)
-}
-
-// listXAttr - list encrypted xattr names on plaintext path "relPath".
-//
-// This function is symlink-safe on Linux by using /proc/self/fd.
-func (fs *FS) listXAttr(relPath string, context *fuse.Context) ([]string, fuse.Status) {
- file, fd, status := fs.getFileFd(relPath, context)
- if !status.Ok() {
- // If relPath is a symlink, getFileFd fails with ELOOP. As setXattr()
- // also fails with ELOOP, there is no way to set xattrs on symlinks,
- // and we can assume that the file does not have any.
- if status == fuse.Status(syscall.ELOOP) {
- return nil, fuse.OK
- }
- return nil, status
- }
- defer file.Release()
-
- cNames, err := xattr.List(procFd(fd))
- if err != nil {
- status := unpackXattrErr(err)
- return nil, status
- }
- return cNames, fuse.OK
-}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-08 10:13:40 +0000