libgocryptfs/internal/fusefrontend/node_dir_ops.go

98 lines
2.8 KiB
Go

package fusefrontend
import (
"context"
"path/filepath"
"syscall"
"github.com/hanwen/go-fuse/v2/fs"
"github.com/hanwen/go-fuse/v2/fuse"
"github.com/rfjakob/gocryptfs/internal/configfile"
"github.com/rfjakob/gocryptfs/internal/nametransform"
"github.com/rfjakob/gocryptfs/internal/syscallcompat"
"github.com/rfjakob/gocryptfs/internal/tlog"
)
func (n *Node) Readdir(ctx context.Context) (fs.DirStream, syscall.Errno) {
rn := n.rootNode()
p := n.path()
dirName := filepath.Base(p)
parentDirFd, cDirName, err := rn.openBackingDir(p)
if err != nil {
return nil, fs.ToErrno(err)
}
defer syscall.Close(parentDirFd)
// Read ciphertext directory
var cipherEntries []fuse.DirEntry
fd, err := syscallcompat.Openat(parentDirFd, cDirName, syscall.O_RDONLY|syscall.O_DIRECTORY|syscall.O_NOFOLLOW, 0)
if err != nil {
return nil, fs.ToErrno(err)
}
defer syscall.Close(fd)
cipherEntries, err = syscallcompat.Getdents(fd)
if err != nil {
return nil, fs.ToErrno(err)
}
// Get DirIV (stays nil if PlaintextNames is used)
var cachedIV []byte
if !rn.args.PlaintextNames {
// Read the DirIV from disk
cachedIV, err = nametransform.ReadDirIVAt(fd)
if err != nil {
tlog.Warn.Printf("OpenDir %q: could not read %s: %v", cDirName, nametransform.DirIVFilename, err)
return nil, syscall.EIO
}
}
// Decrypted directory entries
var plain []fuse.DirEntry
// Filter and decrypt filenames
for i := range cipherEntries {
cName := cipherEntries[i].Name
if dirName == "." && cName == configfile.ConfDefaultName {
// silently ignore "gocryptfs.conf" in the top level dir
continue
}
if rn.args.PlaintextNames {
plain = append(plain, cipherEntries[i])
continue
}
if cName == nametransform.DirIVFilename {
// silently ignore "gocryptfs.diriv" everywhere if dirIV is enabled
continue
}
// Handle long file name
isLong := nametransform.LongNameNone
if rn.args.LongNames {
isLong = nametransform.NameType(cName)
}
if isLong == nametransform.LongNameContent {
cNameLong, err := nametransform.ReadLongNameAt(fd, cName)
if err != nil {
tlog.Warn.Printf("OpenDir %q: invalid entry %q: Could not read .name: %v",
cDirName, cName, err)
rn.reportMitigatedCorruption(cName)
continue
}
cName = cNameLong
} else if isLong == nametransform.LongNameFilename {
// ignore "gocryptfs.longname.*.name"
continue
}
name, err := rn.nameTransform.DecryptName(cName, cachedIV)
if err != nil {
tlog.Warn.Printf("OpenDir %q: invalid entry %q: %v",
cDirName, cName, err)
rn.reportMitigatedCorruption(cName)
continue
}
// Override the ciphertext name with the plaintext name but reuse the rest
// of the structure
cipherEntries[i].Name = name
plain = append(plain, cipherEntries[i])
}
return fs.NewListDirStream(plain), 0
}