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-rw-r--r--internal/fusefrontend/xattr.go83
-rw-r--r--internal/fusefrontend/xattr_darwin.go78
-rw-r--r--internal/fusefrontend/xattr_linux.go62
-rw-r--r--internal/syscallcompat/sys_common.go23
-rw-r--r--tests/xattr/xattr_integration_test.go30
5 files changed, 201 insertions, 75 deletions
diff --git a/internal/fusefrontend/xattr.go b/internal/fusefrontend/xattr.go
index 2248bad..1de9cac 100644
--- a/internal/fusefrontend/xattr.go
+++ b/internal/fusefrontend/xattr.go
@@ -2,16 +2,11 @@
package fusefrontend
import (
- "fmt"
- "runtime"
"strings"
"syscall"
- "golang.org/x/sys/unix"
-
"github.com/hanwen/go-fuse/fuse"
- "github.com/rfjakob/gocryptfs/internal/syscallcompat"
"github.com/rfjakob/gocryptfs/internal/tlog"
)
@@ -36,18 +31,11 @@ func (fs *FS) GetXAttr(relPath string, attr string, context *fuse.Context) ([]by
return nil, _EOPNOTSUPP
}
- // O_NONBLOCK to not block on FIFOs.
- fd, err := fs.openBackingFile(relPath, syscall.O_RDONLY|syscall.O_NONBLOCK)
- if err != nil {
- return nil, fuse.ToStatus(err)
- }
- defer syscall.Close(fd)
-
cAttr := fs.encryptXattrName(attr)
- cData, err := syscallcompat.Fgetxattr(fd, cAttr)
- if err != nil {
- return nil, fuse.ToStatus(err)
+ cData, status := fs.getXAttr(relPath, cAttr, context)
+ if !status.Ok() {
+ return nil, status
}
data, err := fs.decryptXattrValue(cData)
@@ -69,26 +57,10 @@ func (fs *FS) SetXAttr(relPath string, attr string, data []byte, flags int, cont
return _EOPNOTSUPP
}
- // O_NONBLOCK to not block on FIFOs.
- fd, err := fs.openBackingFile(relPath, syscall.O_WRONLY|syscall.O_NONBLOCK)
- // Directories cannot be opened read-write. Retry.
- if err == syscall.EISDIR {
- fd, err = fs.openBackingFile(relPath, syscall.O_RDONLY|syscall.O_DIRECTORY|syscall.O_NONBLOCK)
- }
- if err != nil {
- return fuse.ToStatus(err)
- }
- defer syscall.Close(fd)
-
flags = filterXattrSetFlags(flags)
cAttr := fs.encryptXattrName(attr)
cData := fs.encryptXattrValue(data)
-
- err = unix.Fsetxattr(fd, cAttr, cData, flags)
- if err != nil {
- return fuse.ToStatus(err)
- }
- return fuse.OK
+ return fs.setXAttr(relPath, cAttr, cData, flags, context)
}
// RemoveXAttr - FUSE call.
@@ -102,23 +74,8 @@ func (fs *FS) RemoveXAttr(relPath string, attr string, context *fuse.Context) fu
return _EOPNOTSUPP
}
- // O_NONBLOCK to not block on FIFOs.
- fd, err := fs.openBackingFile(relPath, syscall.O_WRONLY|syscall.O_NONBLOCK)
- // Directories cannot be opened read-write. Retry.
- if err == syscall.EISDIR {
- fd, err = fs.openBackingFile(relPath, syscall.O_RDONLY|syscall.O_DIRECTORY|syscall.O_NONBLOCK)
- }
- if err != nil {
- return fuse.ToStatus(err)
- }
- defer syscall.Close(fd)
-
cAttr := fs.encryptXattrName(attr)
- err = unix.Fremovexattr(fd, cAttr)
- if err != nil {
- return fuse.ToStatus(err)
- }
- return fuse.OK
+ return fs.removeXAttr(relPath, cAttr, context)
}
// ListXAttr - FUSE call. Lists extended attributes on the file at "relPath".
@@ -128,32 +85,10 @@ func (fs *FS) ListXAttr(relPath string, context *fuse.Context) ([]string, fuse.S
if fs.isFiltered(relPath) {
return nil, fuse.EPERM
}
- var cNames []string
- var err error
- if runtime.GOOS == "linux" {
- dirfd, cName, err2 := fs.openBackingDir(relPath)
- if err2 != nil {
- return nil, fuse.ToStatus(err2)
- }
- defer syscall.Close(dirfd)
- procPath := fmt.Sprintf("/proc/self/fd/%d/%s", dirfd, cName)
- cNames, err = syscallcompat.Llistxattr(procPath)
- } else {
- // O_NONBLOCK to not block on FIFOs.
- fd, err2 := fs.openBackingFile(relPath, syscall.O_RDONLY|syscall.O_NONBLOCK)
- // On a symlink, openBackingFile fails with ELOOP. Let's pretend there
- // can be no xattrs on symlinks, and always return an empty result.
- if err2 == syscall.ELOOP {
- return nil, fuse.OK
- }
- if err2 != nil {
- return nil, fuse.ToStatus(err2)
- }
- defer syscall.Close(fd)
- cNames, err = syscallcompat.Flistxattr(fd)
- }
- if err != nil {
- return nil, fuse.ToStatus(err)
+
+ cNames, status := fs.listXAttr(relPath, context)
+ if !status.Ok() {
+ return nil, status
}
names := make([]string, 0, len(cNames))
diff --git a/internal/fusefrontend/xattr_darwin.go b/internal/fusefrontend/xattr_darwin.go
index 8760480..741eb6c 100644
--- a/internal/fusefrontend/xattr_darwin.go
+++ b/internal/fusefrontend/xattr_darwin.go
@@ -3,6 +3,16 @@
// Package fusefrontend interfaces directly with the go-fuse library.
package fusefrontend
+import (
+ "syscall"
+
+ "golang.org/x/sys/unix"
+
+ "github.com/hanwen/go-fuse/fuse"
+
+ "github.com/rfjakob/gocryptfs/internal/syscallcompat"
+)
+
func disallowedXAttrName(attr string) bool {
return false
}
@@ -14,3 +24,71 @@ func filterXattrSetFlags(flags int) int {
return flags &^ XATTR_NOSECURITY
}
+
+func (fs *FS) getXAttr(relPath string, cAttr string, context *fuse.Context) ([]byte, fuse.Status) {
+ // O_NONBLOCK to not block on FIFOs.
+ fd, err := fs.openBackingFile(relPath, syscall.O_RDONLY|syscall.O_NONBLOCK)
+ if err != nil {
+ return nil, fuse.ToStatus(err)
+ }
+ defer syscall.Close(fd)
+
+ cData, err := syscallcompat.Fgetxattr(fd, cAttr)
+ if err != nil {
+ return nil, fuse.ToStatus(err)
+ }
+
+ return cData, fuse.OK
+}
+
+func (fs *FS) setXAttr(relPath string, cAttr string, cData []byte, flags int, context *fuse.Context) fuse.Status {
+ // O_NONBLOCK to not block on FIFOs.
+ fd, err := fs.openBackingFile(relPath, syscall.O_WRONLY|syscall.O_NONBLOCK)
+ // Directories cannot be opened read-write. Retry.
+ if err == syscall.EISDIR {
+ fd, err = fs.openBackingFile(relPath, syscall.O_RDONLY|syscall.O_DIRECTORY|syscall.O_NONBLOCK)
+ }
+ if err != nil {
+ return fuse.ToStatus(err)
+ }
+ defer syscall.Close(fd)
+
+ err = unix.Fsetxattr(fd, cAttr, cData, flags)
+ return fuse.ToStatus(err)
+}
+
+func (fs *FS) removeXAttr(relPath string, cAttr string, context *fuse.Context) fuse.Status {
+ // O_NONBLOCK to not block on FIFOs.
+ fd, err := fs.openBackingFile(relPath, syscall.O_WRONLY|syscall.O_NONBLOCK)
+ // Directories cannot be opened read-write. Retry.
+ if err == syscall.EISDIR {
+ fd, err = fs.openBackingFile(relPath, syscall.O_RDONLY|syscall.O_DIRECTORY|syscall.O_NONBLOCK)
+ }
+ if err != nil {
+ return fuse.ToStatus(err)
+ }
+ defer syscall.Close(fd)
+
+ err = unix.Fremovexattr(fd, cAttr)
+ return fuse.ToStatus(err)
+}
+
+func (fs *FS) listXAttr(relPath string, context *fuse.Context) ([]string, fuse.Status) {
+ // O_NONBLOCK to not block on FIFOs.
+ fd, err := fs.openBackingFile(relPath, syscall.O_RDONLY|syscall.O_NONBLOCK)
+ // On a symlink, openBackingFile fails with ELOOP. Let's pretend there
+ // can be no xattrs on symlinks, and always return an empty result.
+ if err == syscall.ELOOP {
+ return nil, fuse.OK
+ }
+ if err != nil {
+ return nil, fuse.ToStatus(err)
+ }
+ defer syscall.Close(fd)
+
+ cNames, err := syscallcompat.Flistxattr(fd)
+ if err != nil {
+ return nil, fuse.ToStatus(err)
+ }
+ return cNames, fuse.OK
+}
diff --git a/internal/fusefrontend/xattr_linux.go b/internal/fusefrontend/xattr_linux.go
index fd3b7e5..3a64412 100644
--- a/internal/fusefrontend/xattr_linux.go
+++ b/internal/fusefrontend/xattr_linux.go
@@ -4,7 +4,15 @@
package fusefrontend
import (
+ "fmt"
"strings"
+ "syscall"
+
+ "golang.org/x/sys/unix"
+
+ "github.com/hanwen/go-fuse/fuse"
+
+ "github.com/rfjakob/gocryptfs/internal/syscallcompat"
)
// Only allow the "user" namespace, block "trusted" and "security", as
@@ -19,3 +27,57 @@ func disallowedXAttrName(attr string) bool {
func filterXattrSetFlags(flags int) int {
return flags
}
+
+func (fs *FS) getXAttr(relPath string, cAttr string, context *fuse.Context) ([]byte, fuse.Status) {
+ dirfd, cName, err := fs.openBackingDir(relPath)
+ if err != nil {
+ return nil, fuse.ToStatus(err)
+ }
+ defer syscall.Close(dirfd)
+
+ procPath := fmt.Sprintf("/proc/self/fd/%d/%s", dirfd, cName)
+ cData, err := syscallcompat.Lgetxattr(procPath, cAttr)
+ if err != nil {
+ return nil, fuse.ToStatus(err)
+ }
+ return cData, fuse.OK
+}
+
+func (fs *FS) setXAttr(relPath string, cAttr string, cData []byte, flags int, context *fuse.Context) fuse.Status {
+ dirfd, cName, err := fs.openBackingDir(relPath)
+ if err != nil {
+ return fuse.ToStatus(err)
+ }
+ defer syscall.Close(dirfd)
+
+ procPath := fmt.Sprintf("/proc/self/fd/%d/%s", dirfd, cName)
+ err = unix.Lsetxattr(procPath, cAttr, cData, flags)
+ return fuse.ToStatus(err)
+}
+
+func (fs *FS) removeXAttr(relPath string, cAttr string, context *fuse.Context) fuse.Status {
+ dirfd, cName, err := fs.openBackingDir(relPath)
+ if err != nil {
+ return fuse.ToStatus(err)
+ }
+ defer syscall.Close(dirfd)
+
+ procPath := fmt.Sprintf("/proc/self/fd/%d/%s", dirfd, cName)
+ err = unix.Lremovexattr(procPath, cAttr)
+ return fuse.ToStatus(err)
+}
+
+func (fs *FS) listXAttr(relPath string, context *fuse.Context) ([]string, fuse.Status) {
+ dirfd, cName, err := fs.openBackingDir(relPath)
+ if err != nil {
+ return nil, fuse.ToStatus(err)
+ }
+ defer syscall.Close(dirfd)
+
+ procPath := fmt.Sprintf("/proc/self/fd/%d/%s", dirfd, cName)
+ cNames, err := syscallcompat.Llistxattr(procPath)
+ if err != nil {
+ return nil, fuse.ToStatus(err)
+ }
+ return cNames, fuse.OK
+}
diff --git a/internal/syscallcompat/sys_common.go b/internal/syscallcompat/sys_common.go
index 4ce0208..a1aa66d 100644
--- a/internal/syscallcompat/sys_common.go
+++ b/internal/syscallcompat/sys_common.go
@@ -84,6 +84,29 @@ func Fgetxattr(fd int, attr string) (val []byte, err error) {
return val, nil
}
+// Lgetxattr is a wrapper around unix.Lgetxattr that handles the buffer sizing.
+func Lgetxattr(path string, attr string) (val []byte, err error) {
+ // See the buffer sizing comments in Fgetxattr.
+ // TODO: smarter buffer sizing?
+ buf := make([]byte, XATTR_BUFSZ)
+ sz, err := unix.Lgetxattr(path, attr, buf)
+ if err == syscall.ERANGE {
+ // Do NOT return ERANGE - the user might retry ad inifinitum!
+ return nil, syscall.EOVERFLOW
+ }
+ if err != nil {
+ return nil, err
+ }
+ if sz >= XATTR_SIZE_MAX {
+ return nil, syscall.EOVERFLOW
+ }
+ // Copy only the actually used bytes to a new (smaller) buffer
+ // so "buf" never leaves the function and can be allocated on the stack.
+ val = make([]byte, sz)
+ copy(val, buf)
+ return val, nil
+}
+
// Flistxattr is a wrapper for unix.Flistxattr that handles buffer sizing and
// parsing the returned blob to a string slice.
func Flistxattr(fd int) (attrs []string, err error) {
diff --git a/tests/xattr/xattr_integration_test.go b/tests/xattr/xattr_integration_test.go
index f182fd9..29c3e84 100644
--- a/tests/xattr/xattr_integration_test.go
+++ b/tests/xattr/xattr_integration_test.go
@@ -129,7 +129,7 @@ func TestSetGetRmDir(t *testing.T) {
fn := test_helpers.DefaultPlainDir + "/TestSetGetRmDir"
err := syscall.Mkdir(fn, 0700)
if err != nil {
- t.Fatalf("creating fifo failed: %v", err)
+ t.Fatalf("creating directory failed: %v", err)
}
setGetRmList(fn)
}
@@ -316,3 +316,31 @@ func TestSet0200File(t *testing.T) {
t.Error(err)
}
}
+
+// Listing xattrs should work even when we don't have read access
+func TestList0000Dir(t *testing.T) {
+ fn := test_helpers.DefaultPlainDir + "/TestList0000Dir"
+ err := syscall.Mkdir(fn, 0000)
+ if err != nil {
+ t.Fatalf("creating directory failed: %v", err)
+ }
+ _, err = xattr.LList(fn)
+ os.Chmod(fn, 0700)
+ if err != nil {
+ t.Error(err)
+ }
+}
+
+// Setting xattrs should work even when we don't have read access
+func TestSet0200Dir(t *testing.T) {
+ fn := test_helpers.DefaultPlainDir + "/TestSet0200Dir"
+ err := syscall.Mkdir(fn, 0200)
+ if err != nil {
+ t.Fatalf("creating directory failed: %v", err)
+ }
+ err = xattr.LSet(fn, "user.foo", []byte("bar"))
+ os.Chmod(fn, 0700)
+ if err != nil {
+ t.Error(err)
+ }
+}