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authorJakob Unterwurzacher2020-08-09 22:11:46 +0200
committerJakob Unterwurzacher2020-08-09 22:11:46 +0200
commit6d4f1a6888cafd218cb97bd11de6a7553d9bc8f1 (patch)
tree7b48b6e97c4c73a4e0e9dce3456768526c46da65 /internal/fusefrontend_reverse/node.go
parent527609266386890fe1657c225c643ca448bcd71d (diff)
v2api/reverse: implement Read
Diffstat (limited to 'internal/fusefrontend_reverse/node.go')
-rw-r--r--internal/fusefrontend_reverse/node.go86
1 files changed, 76 insertions, 10 deletions
diff --git a/internal/fusefrontend_reverse/node.go b/internal/fusefrontend_reverse/node.go
index 884a97e..deaf953 100644
--- a/internal/fusefrontend_reverse/node.go
+++ b/internal/fusefrontend_reverse/node.go
@@ -2,6 +2,8 @@ package fusefrontend_reverse
import (
"context"
+ "fmt"
+ "os"
"path/filepath"
"syscall"
@@ -10,8 +12,10 @@ import (
"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/contentenc"
+ "github.com/rfjakob/gocryptfs/internal/pathiv"
"github.com/rfjakob/gocryptfs/internal/syscallcompat"
+ "github.com/rfjakob/gocryptfs/internal/tlog"
)
// Node is a file or directory in the filesystem tree
@@ -33,15 +37,7 @@ func (n *Node) Lookup(ctx context.Context, cName string, out *fuse.EntryOut) (ch
return n.lookupLongnameName(ctx, cName, out)
} else if t == typeConfig {
// gocryptfs.conf
- var err error
- pName = configfile.ConfReverseName
- rn := n.rootNode()
- dirfd, err = syscallcompat.OpenDirNofollow(rn.args.Cipherdir, "")
- if err != nil {
- errno = fs.ToErrno(err)
- return
- }
- defer syscall.Close(dirfd)
+ return n.lookupConf(ctx, out)
} else if t == typeReal {
// real file
dirfd, pName, errno = n.prepareAtSyscall(cName)
@@ -112,3 +108,73 @@ func (n *Node) Readlink(ctx context.Context) (out []byte, errno syscall.Errno) {
cName := filepath.Base(n.Path())
return n.readlink(dirfd, cName, pName)
}
+
+// Open - FUSE call. Open already-existing file.
+//
+// Symlink-safe through Openat().
+func (n *Node) Open(ctx context.Context, flags uint32) (fh fs.FileHandle, fuseFlags uint32, errno syscall.Errno) {
+ dirfd, pName, errno := n.prepareAtSyscall("")
+ if errno != 0 {
+ return
+ }
+ defer syscall.Close(dirfd)
+
+ fd, err := syscallcompat.Openat(dirfd, pName, syscall.O_RDONLY|syscall.O_NOFOLLOW, 0)
+ if err != nil {
+ errno = fs.ToErrno(err)
+ return
+ }
+
+ // Reject access if the file descriptor does not refer to a regular file.
+ var st syscall.Stat_t
+ err = syscall.Fstat(fd, &st)
+ if err != nil {
+ tlog.Warn.Printf("Open: Fstat error: %v", err)
+ syscall.Close(fd)
+ errno = fs.ToErrno(err)
+ return
+ }
+ var a fuse.Attr
+ a.FromStat(&st)
+ if !a.IsRegular() {
+ tlog.Warn.Printf("ino%d: newFile: not a regular file", st.Ino)
+ syscall.Close(fd)
+ errno = syscall.EACCES
+ return
+ }
+ // See if we have that inode number already in the table
+ // (even if Nlink has dropped to 1)
+ var derivedIVs pathiv.FileIVs
+ v, found := inodeTable.Load(st.Ino)
+ if found {
+ tlog.Debug.Printf("ino%d: newFile: found in the inode table", st.Ino)
+ derivedIVs = v.(pathiv.FileIVs)
+ } else {
+ p := n.Path()
+ derivedIVs = pathiv.DeriveFile(p)
+ // Nlink > 1 means there is more than one path to this file.
+ // Store the derived values so we always return the same data,
+ // regardless of the path that is used to access the file.
+ // This means that the first path wins.
+ if st.Nlink > 1 {
+ v, found = inodeTable.LoadOrStore(st.Ino, derivedIVs)
+ if found {
+ // Another thread has stored a different value before we could.
+ derivedIVs = v.(pathiv.FileIVs)
+ } else {
+ tlog.Debug.Printf("ino%d: newFile: Nlink=%d, stored in the inode table", st.Ino, st.Nlink)
+ }
+ }
+ }
+ header := contentenc.FileHeader{
+ Version: contentenc.CurrentVersion,
+ ID: derivedIVs.ID,
+ }
+ fh = &File{
+ fd: os.NewFile(uintptr(fd), fmt.Sprintf("fd%d", fd)),
+ header: header,
+ block0IV: derivedIVs.Block0IV,
+ contentEnc: n.rootNode().contentEnc,
+ }
+ return
+}