Re-design of the original gocryptfs code to work as a library.
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 

94 lines
2.6 KiB

package main
import (
"C"
"syscall"
"golang.org/x/sys/unix"
"libgocryptfs/v2/internal/nametransform"
"libgocryptfs/v2/internal/syscallcompat"
)
//export gcf_get_attrs
func gcf_get_attrs(sessionID int, relPath string) (uint64, int64, bool) {
volume, ok := OpenedVolumes[sessionID]
if !ok {
return 0, 0, false
}
dirfd, cName, err := volume.prepareAtSyscall(relPath)
if err != nil {
return 0, 0, false
}
defer syscall.Close(dirfd)
st, err := syscallcompat.Fstatat2(dirfd, cName, unix.AT_SYMLINK_NOFOLLOW)
if err != nil {
return 0, 0, false
}
// Translate ciphertext size to plaintext size
size := volume.translateSize(dirfd, cName, st)
return size, int64(st.Mtim.Sec), true
}
// libgocryptfs: using Renameat instead of Renameat2 to support older kernels
//export gcf_rename
func gcf_rename(sessionID int, oldPath string, newPath string) bool {
volume, ok := OpenedVolumes[sessionID]
if !ok {
return false
}
dirfd, cName, err := volume.prepareAtSyscall(oldPath)
if err != nil {
return false
}
defer syscall.Close(dirfd)
dirfd2, cName2, err := volume.prepareAtSyscall(newPath)
if err != nil {
return false
}
defer syscall.Close(dirfd2)
// Easy case.
if volume.plainTextNames {
return errToBool(syscallcompat.Renameat(dirfd, cName, dirfd2, cName2))
}
// Long destination file name: create .name file
nameFileAlreadyThere := false
if nametransform.IsLongContent(cName2) {
err = volume.nameTransform.WriteLongNameAt(dirfd2, cName2, newPath)
// Failure to write the .name file is expected when the target path already
// exists. Since hashes are pretty unique, there is no need to modify the
// .name file in this case, and we ignore the error.
if err == syscall.EEXIST {
nameFileAlreadyThere = true
} else if err != nil {
return false
}
}
// Actual rename
err = syscallcompat.Renameat(dirfd, cName, dirfd2, cName2)
if err == syscall.ENOTEMPTY || err == syscall.EEXIST {
// If an empty directory is overwritten we will always get an error as
// the "empty" directory will still contain gocryptfs.diriv.
// Interestingly, ext4 returns ENOTEMPTY while xfs returns EEXIST.
// We handle that by trying to fs.Rmdir() the target directory and trying
// again.
if gcf_rmdir(sessionID, newPath) {
err = syscallcompat.Renameat(dirfd, cName, dirfd2, cName2)
}
}
if err != nil {
if nametransform.IsLongContent(cName2) && !nameFileAlreadyThere {
// Roll back .name creation unless the .name file was already there
nametransform.DeleteLongNameAt(dirfd2, cName2)
}
return false
}
if nametransform.IsLongContent(cName) {
nametransform.DeleteLongNameAt(dirfd, cName)
}
return true
}