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Diffstat (limited to 'internal')
-rw-r--r--internal/fusefrontend/fs.go11
-rw-r--r--internal/fusefrontend/xattr.go88
-rw-r--r--internal/syscallcompat/sys_common.go34
3 files changed, 82 insertions, 51 deletions
diff --git a/internal/fusefrontend/fs.go b/internal/fusefrontend/fs.go
index e7c3903..5c52a19 100644
--- a/internal/fusefrontend/fs.go
+++ b/internal/fusefrontend/fs.go
@@ -160,6 +160,17 @@ func (fs *FS) Open(path string, flags uint32, context *fuse.Context) (fuseFile n
return NewFile(f, fs)
}
+// openBackingFile opens the ciphertext file that backs relative plaintext
+// path "relPath". Always adds O_NOFOLLOW to the flags.
+func (fs *FS) openBackingFile(relPath string, flags int) (fd int, err error) {
+ dirfd, cName, err := fs.openBackingDir(relPath)
+ if err != nil {
+ return -1, err
+ }
+ defer syscall.Close(dirfd)
+ return syscallcompat.Openat(dirfd, cName, flags|syscall.O_NOFOLLOW, 0)
+}
+
// Due to RMW, we always need read permissions on the backing file. This is a
// problem if the file permissions do not allow reading (i.e. 0200 permissions).
// This function works around that problem by chmod'ing the file, obtaining a fd,
diff --git a/internal/fusefrontend/xattr.go b/internal/fusefrontend/xattr.go
index 045f963..7ffec25 100644
--- a/internal/fusefrontend/xattr.go
+++ b/internal/fusefrontend/xattr.go
@@ -2,6 +2,8 @@
package fusefrontend
import (
+ "fmt"
+ "runtime"
"strings"
"syscall"
@@ -34,11 +36,12 @@ func (fs *FS) GetXAttr(relPath string, attr string, context *fuse.Context) ([]by
return nil, _EOPNOTSUPP
}
- file, fd, status := fs.getFileFd(relPath, context)
- if !status.Ok() {
- return nil, 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 file.Release()
+ defer syscall.Close(fd)
cAttr := fs.encryptXattrName(attr)
@@ -66,17 +69,18 @@ func (fs *FS) SetXAttr(relPath string, attr string, data []byte, flags int, cont
return _EOPNOTSUPP
}
- file, fd, status := fs.getFileFd(relPath, context)
- if !status.Ok() {
- return status
+ // O_NONBLOCK to not block on FIFOs.
+ fd, err := fs.openBackingFile(relPath, syscall.O_WRONLY|syscall.O_NONBLOCK)
+ if err != nil {
+ return fuse.ToStatus(err)
}
- defer file.Release()
+ defer syscall.Close(fd)
flags = filterXattrSetFlags(flags)
cAttr := fs.encryptXattrName(attr)
cData := fs.encryptXattrValue(data)
- err := unix.Fsetxattr(fd, cAttr, cData, flags)
+ err = unix.Fsetxattr(fd, cAttr, cData, flags)
if err != nil {
return fuse.ToStatus(err)
}
@@ -94,14 +98,15 @@ func (fs *FS) RemoveXAttr(relPath string, attr string, context *fuse.Context) fu
return _EOPNOTSUPP
}
- file, fd, status := fs.getFileFd(relPath, context)
- if !status.Ok() {
- return status
+ // O_NONBLOCK to not block on FIFOs.
+ fd, err := fs.openBackingFile(relPath, syscall.O_WRONLY|syscall.O_NONBLOCK)
+ if err != nil {
+ return fuse.ToStatus(err)
}
- defer file.Release()
+ defer syscall.Close(fd)
cAttr := fs.encryptXattrName(attr)
- err := unix.Fremovexattr(fd, cAttr)
+ err = unix.Fremovexattr(fd, cAttr)
if err != nil {
return fuse.ToStatus(err)
}
@@ -115,19 +120,30 @@ func (fs *FS) ListXAttr(relPath string, context *fuse.Context) ([]string, fuse.S
if fs.isFiltered(relPath) {
return nil, fuse.EPERM
}
-
- 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
+ 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_WRONLY|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)
}
- defer file.Release()
-
- cNames, err := syscallcompat.Flistxattr(fd)
if err != nil {
return nil, fuse.ToStatus(err)
}
@@ -199,23 +215,3 @@ func (fs *FS) decryptXattrValue(cData []byte) (data []byte, err error) {
}
return fs.contentEnc.DecryptBlock([]byte(cData), 0, nil)
}
-
-// 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
-}
diff --git a/internal/syscallcompat/sys_common.go b/internal/syscallcompat/sys_common.go
index 3a0d5a1..4ce0208 100644
--- a/internal/syscallcompat/sys_common.go
+++ b/internal/syscallcompat/sys_common.go
@@ -64,7 +64,7 @@ func Fgetxattr(fd int, attr string) (val []byte, err error) {
// only happen on MacOS).
//
// See https://github.com/pkg/xattr for a smarter solution.
- // TODO: be smarter?
+ // TODO: smarter buffer sizing?
buf := make([]byte, XATTR_BUFSZ)
sz, err := unix.Fgetxattr(fd, attr, buf)
if err == syscall.ERANGE {
@@ -84,11 +84,11 @@ func Fgetxattr(fd int, attr string) (val []byte, err error) {
return val, nil
}
-// Flistxattr is a wrapper unix.Flistxattr that handles buffer sizing and
+// 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) {
// See the buffer sizing comments in Fgetxattr.
- // TODO: be smarter?
+ // TODO: smarter buffer sizing?
buf := make([]byte, XATTR_BUFSZ)
sz, err := unix.Flistxattr(fd, buf)
if err == syscall.ERANGE {
@@ -101,7 +101,31 @@ func Flistxattr(fd int) (attrs []string, err error) {
if sz >= XATTR_SIZE_MAX {
return nil, syscall.EOVERFLOW
}
- buf = buf[:sz]
+ attrs = parseListxattrBlob(buf[:sz])
+ return attrs, nil
+}
+
+// Llistxattr is a wrapper for unix.Llistxattr that handles buffer sizing and
+// parsing the returned blob to a string slice.
+func Llistxattr(path string) (attrs []string, err error) {
+ // TODO: smarter buffer sizing?
+ buf := make([]byte, XATTR_BUFSZ)
+ sz, err := unix.Llistxattr(path, 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
+ }
+ attrs = parseListxattrBlob(buf[:sz])
+ return attrs, nil
+}
+
+func parseListxattrBlob(buf []byte) (attrs []string) {
parts := bytes.Split(buf, []byte{0})
for _, part := range parts {
if len(part) == 0 {
@@ -110,5 +134,5 @@ func Flistxattr(fd int) (attrs []string, err error) {
}
attrs = append(attrs, string(part))
}
- return attrs, nil
+ return attrs
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-10 23:06:41 +0000