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-rw-r--r--internal/fusefrontend/dircache.go8
-rw-r--r--internal/fusefrontend/node.go8
-rw-r--r--internal/fusefrontend/node_dir_ops.go4
-rw-r--r--internal/fusefrontend/node_helpers.go89
-rw-r--r--internal/fusefrontend/node_open_create.go2
-rw-r--r--internal/fusefrontend/node_prepare_syscall.go116
-rw-r--r--internal/fusefrontend/node_xattr_darwin.go8
-rw-r--r--internal/fusefrontend/node_xattr_linux.go8
-rw-r--r--internal/fusefrontend/root_node.go11
9 files changed, 144 insertions, 110 deletions
diff --git a/internal/fusefrontend/dircache.go b/internal/fusefrontend/dircache.go
index 6732de1..8c285fa 100644
--- a/internal/fusefrontend/dircache.go
+++ b/internal/fusefrontend/dircache.go
@@ -7,7 +7,6 @@ import (
"syscall"
"time"
- "github.com/rfjakob/gocryptfs/internal/nametransform"
"github.com/rfjakob/gocryptfs/internal/tlog"
)
@@ -50,6 +49,9 @@ func (e *dirCacheEntry) Clear() {
type dirCache struct {
sync.Mutex
+ // Expected length of the stored IVs. Only used for sanity checks.
+ // Usually set to 16, but 0 in plaintextnames mode.
+ ivLen int
// Cache entries
entries [dirCacheSize]dirCacheEntry
// Where to store the next entry (index into entries)
@@ -77,7 +79,7 @@ func (d *dirCache) Clear() {
func (d *dirCache) Store(node *Node, fd int, iv []byte) {
// Note: package ensurefds012, imported from main, guarantees that dirCache
// can never get fds 0,1,2.
- if fd <= 0 || len(iv) != nametransform.DirIVLen {
+ if fd <= 0 || len(iv) != d.ivLen {
log.Panicf("Store sanity check failed: fd=%d len=%d", fd, len(iv))
}
d.Lock()
@@ -139,7 +141,7 @@ func (d *dirCache) Lookup(node *Node) (fd int, iv []byte) {
if enableStats {
d.hits++
}
- if fd <= 0 || len(iv) != nametransform.DirIVLen {
+ if fd <= 0 || len(iv) != d.ivLen {
log.Panicf("Lookup sanity check failed: fd=%d len=%d", fd, len(iv))
}
d.dbg("dirCache.Lookup %p hit fd=%d dup=%d iv=%x\n", node, e.fd, fd, iv)
diff --git a/internal/fusefrontend/node.go b/internal/fusefrontend/node.go
index 8370a22..dd446a3 100644
--- a/internal/fusefrontend/node.go
+++ b/internal/fusefrontend/node.go
@@ -52,7 +52,7 @@ func (n *Node) Getattr(ctx context.Context, f fs.FileHandle, out *fuse.AttrOut)
return f.(fs.FileGetattrer).Getattr(ctx, out)
}
- dirfd, cName, errno := n.prepareAtSyscall("")
+ dirfd, cName, errno := n.prepareAtSyscallMyself()
if errno != 0 {
return
}
@@ -106,7 +106,7 @@ func (n *Node) Unlink(ctx context.Context, name string) (errno syscall.Errno) {
//
// Symlink-safe through openBackingDir() + Readlinkat().
func (n *Node) Readlink(ctx context.Context) (out []byte, errno syscall.Errno) {
- dirfd, cName, errno := n.prepareAtSyscall("")
+ dirfd, cName, errno := n.prepareAtSyscallMyself()
if errno != 0 {
return
}
@@ -123,7 +123,7 @@ func (n *Node) Setattr(ctx context.Context, f fs.FileHandle, in *fuse.SetAttrIn,
return f2.Setattr(ctx, in, out)
}
- dirfd, cName, errno := n.prepareAtSyscall("")
+ dirfd, cName, errno := n.prepareAtSyscallMyself()
if errno != 0 {
return
}
@@ -271,7 +271,7 @@ func (n *Node) Link(ctx context.Context, target fs.InodeEmbedder, name string, o
defer syscall.Close(dirfd)
n2 := toNode(target)
- dirfd2, cName2, errno := n2.prepareAtSyscall("")
+ dirfd2, cName2, errno := n2.prepareAtSyscallMyself()
if errno != 0 {
return
}
diff --git a/internal/fusefrontend/node_dir_ops.go b/internal/fusefrontend/node_dir_ops.go
index 001c23a..0f48876 100644
--- a/internal/fusefrontend/node_dir_ops.go
+++ b/internal/fusefrontend/node_dir_ops.go
@@ -154,7 +154,7 @@ func (n *Node) Mkdir(ctx context.Context, name string, mode uint32, out *fuse.En
// This function is symlink-safe through use of openBackingDir() and
// ReadDirIVAt().
func (n *Node) Readdir(ctx context.Context) (fs.DirStream, syscall.Errno) {
- parentDirFd, cDirName, errno := n.prepareAtSyscall("")
+ parentDirFd, cDirName, errno := n.prepareAtSyscallMyself()
if errno != 0 {
return nil, errno
}
@@ -360,7 +360,7 @@ retry:
// Opendir is a FUSE call to check if the directory can be opened.
func (n *Node) Opendir(ctx context.Context) (errno syscall.Errno) {
- dirfd, cName, errno := n.prepareAtSyscall("")
+ dirfd, cName, errno := n.prepareAtSyscallMyself()
if errno != 0 {
return
}
diff --git a/internal/fusefrontend/node_helpers.go b/internal/fusefrontend/node_helpers.go
index f2d1e5e..ce2e8a9 100644
--- a/internal/fusefrontend/node_helpers.go
+++ b/internal/fusefrontend/node_helpers.go
@@ -2,16 +2,12 @@ package fusefrontend
import (
"context"
- "log"
- "path/filepath"
- "sync/atomic"
"syscall"
"github.com/hanwen/go-fuse/v2/fs"
"github.com/hanwen/go-fuse/v2/fuse"
- "github.com/rfjakob/gocryptfs/internal/nametransform"
"github.com/rfjakob/gocryptfs/internal/syscallcompat"
"github.com/rfjakob/gocryptfs/internal/tlog"
)
@@ -80,91 +76,6 @@ func (n *Node) rootNode() *RootNode {
return n.Root().Operations().(*RootNode)
}
-// prepareAtSyscall returns a (dirfd, cName) pair that can be used
-// with the "___at" family of system calls (openat, fstatat, unlinkat...) to
-// access the backing encrypted directory.
-//
-// If you pass a `child` file name, the (dirfd, cName) pair will refer to
-// a child of this node.
-// If `child` is empty, the (dirfd, cName) pair refers to this node itself. For
-// the root node, that means (dirfd, ".").
-func (n *Node) prepareAtSyscall(child string) (dirfd int, cName string, errno syscall.Errno) {
- rn := n.rootNode()
- // all filesystem operations go through prepareAtSyscall(), so this is a
- // good place to reset the idle marker.
- atomic.StoreUint32(&rn.IsIdle, 0)
-
- // root node itself is special
- if child == "" && n.IsRoot() {
- var err error
- dirfd, cName, err = rn.openBackingDir("")
- if err != nil {
- errno = fs.ToErrno(err)
- }
- return
- }
-
- // normal node itself can be converted to child of parent node
- if child == "" {
- name, p1 := n.Parent()
- if p1 == nil || name == "" {
- return -1, "", syscall.ENOENT
- }
- p2 := toNode(p1.Operations())
- return p2.prepareAtSyscall(name)
- }
-
- // Cache lookup
- // TODO make it work for plaintextnames as well?
- cacheable := (!rn.args.PlaintextNames)
- if cacheable {
- var iv []byte
- dirfd, iv = rn.dirCache.Lookup(n)
- if dirfd > 0 {
- var cName string
- var err error
- if rn.nameTransform.HaveBadnamePatterns() {
- //BadName allowed, try to determine filenames
- cName, err = rn.nameTransform.EncryptAndHashBadName(child, iv, dirfd)
- } else {
- cName, err = rn.nameTransform.EncryptAndHashName(child, iv)
- }
-
- if err != nil {
- return -1, "", fs.ToErrno(err)
- }
- return dirfd, cName, 0
- }
- }
-
- // Slowpath
- if child == "" {
- log.Panicf("BUG: child name is empty - this cannot happen")
- }
- p := filepath.Join(n.Path(), child)
- if rn.isFiltered(p) {
- errno = syscall.EPERM
- return
- }
- dirfd, cName, err := rn.openBackingDir(p)
- if err != nil {
- errno = fs.ToErrno(err)
- return
- }
-
- // Cache store
- if cacheable {
- // TODO: openBackingDir already calls ReadDirIVAt(). Avoid duplicate work?
- iv, err := nametransform.ReadDirIVAt(dirfd)
- if err != nil {
- syscall.Close(dirfd)
- return -1, "", fs.ToErrno(err)
- }
- rn.dirCache.Store(n, dirfd, iv)
- }
- return
-}
-
// newChild attaches a new child inode to n.
// The passed-in `st` will be modified to get a unique inode number
// (or, in `-sharedstorage` mode, the inode number will be set to zero).
diff --git a/internal/fusefrontend/node_open_create.go b/internal/fusefrontend/node_open_create.go
index 8b31932..6385bc1 100644
--- a/internal/fusefrontend/node_open_create.go
+++ b/internal/fusefrontend/node_open_create.go
@@ -16,7 +16,7 @@ import (
//
// Symlink-safe through Openat().
func (n *Node) Open(ctx context.Context, flags uint32) (fh fs.FileHandle, fuseFlags uint32, errno syscall.Errno) {
- dirfd, cName, errno := n.prepareAtSyscall("")
+ dirfd, cName, errno := n.prepareAtSyscallMyself()
if errno != 0 {
return
}
diff --git a/internal/fusefrontend/node_prepare_syscall.go b/internal/fusefrontend/node_prepare_syscall.go
new file mode 100644
index 0000000..fa558e8
--- /dev/null
+++ b/internal/fusefrontend/node_prepare_syscall.go
@@ -0,0 +1,116 @@
+package fusefrontend
+
+import (
+ "sync/atomic"
+ "syscall"
+
+ "github.com/rfjakob/gocryptfs/internal/tlog"
+
+ "github.com/hanwen/go-fuse/v2/fs"
+
+ "github.com/rfjakob/gocryptfs/internal/nametransform"
+ "github.com/rfjakob/gocryptfs/internal/syscallcompat"
+)
+
+// prepareAtSyscall returns a (dirfd, cName) pair that can be used
+// with the "___at" family of system calls (openat, fstatat, unlinkat...) to
+// access the backing encrypted child file.
+func (n *Node) prepareAtSyscall(child string) (dirfd int, cName string, errno syscall.Errno) {
+ if child == "" {
+ tlog.Warn.Printf("BUG: prepareAtSyscall: child=%q, should have called prepareAtSyscallMyself", child)
+ return n.prepareAtSyscallMyself()
+ }
+
+ rn := n.rootNode()
+
+ // All filesystem operations go through here, so this is a good place
+ // to reset the idle marker.
+ atomic.StoreUint32(&rn.IsIdle, 0)
+
+ if n.IsRoot() && rn.isFiltered(child) {
+ return -1, "", syscall.EPERM
+ }
+
+ var encryptName func(int, string, []byte) (string, error)
+ if !rn.args.PlaintextNames {
+ encryptName = func(dirfd int, child string, iv []byte) (cName string, err error) {
+ // Badname allowed, try to determine filenames
+ if rn.nameTransform.HaveBadnamePatterns() {
+ return rn.nameTransform.EncryptAndHashBadName(child, iv, dirfd)
+ }
+ return rn.nameTransform.EncryptAndHashName(child, iv)
+ }
+ }
+
+ // Cache lookup
+ var iv []byte
+ dirfd, iv = rn.dirCache.Lookup(n)
+ if dirfd > 0 {
+ if rn.args.PlaintextNames {
+ return dirfd, child, 0
+ }
+ var err error
+ cName, err = encryptName(dirfd, child, iv)
+ if err != nil {
+ syscall.Close(dirfd)
+ return -1, "", fs.ToErrno(err)
+ }
+ return
+ }
+
+ // Slowpath: Open ourselves & read diriv
+ parentDirfd, myCName, errno := n.prepareAtSyscallMyself()
+ if errno != 0 {
+ return
+ }
+ defer syscall.Close(parentDirfd)
+
+ dirfd, err := syscallcompat.Openat(parentDirfd, myCName, syscall.O_NOFOLLOW|syscall.O_DIRECTORY|syscallcompat.O_PATH, 0)
+
+ // Cache store
+ if !rn.args.PlaintextNames {
+ var err error
+ iv, err = nametransform.ReadDirIVAt(dirfd)
+ if err != nil {
+ syscall.Close(dirfd)
+ return -1, "", fs.ToErrno(err)
+ }
+ }
+ rn.dirCache.Store(n, dirfd, iv)
+
+ if rn.args.PlaintextNames {
+ return dirfd, child, 0
+ }
+
+ cName, err = encryptName(dirfd, child, iv)
+ if err != nil {
+ syscall.Close(dirfd)
+ return -1, "", fs.ToErrno(err)
+ }
+
+ return
+}
+
+func (n *Node) prepareAtSyscallMyself() (dirfd int, cName string, errno syscall.Errno) {
+ dirfd = -1
+
+ // Handle root node
+ if n.IsRoot() {
+ var err error
+ rn := n.rootNode()
+ dirfd, cName, err = rn.openBackingDir("")
+ if err != nil {
+ errno = fs.ToErrno(err)
+ }
+ return
+ }
+
+ // Otherwise convert to prepareAtSyscall of parent node
+ myName, p1 := n.Parent()
+ if p1 == nil || myName == "" {
+ errno = syscall.ENOENT
+ return
+ }
+ parent := toNode(p1.Operations())
+ return parent.prepareAtSyscall(myName)
+}
diff --git a/internal/fusefrontend/node_xattr_darwin.go b/internal/fusefrontend/node_xattr_darwin.go
index 0f61a5d..31ba653 100644
--- a/internal/fusefrontend/node_xattr_darwin.go
+++ b/internal/fusefrontend/node_xattr_darwin.go
@@ -20,7 +20,7 @@ func filterXattrSetFlags(flags int) int {
}
func (n *Node) getXAttr(cAttr string) (out []byte, errno syscall.Errno) {
- dirfd, cName, errno := n.prepareAtSyscall("")
+ dirfd, cName, errno := n.prepareAtSyscallMyself()
if errno != 0 {
return
}
@@ -42,7 +42,7 @@ func (n *Node) getXAttr(cAttr string) (out []byte, errno syscall.Errno) {
}
func (n *Node) setXAttr(context *fuse.Context, cAttr string, cData []byte, flags uint32) (errno syscall.Errno) {
- dirfd, cName, errno := n.prepareAtSyscall("")
+ dirfd, cName, errno := n.prepareAtSyscallMyself()
if errno != 0 {
return
}
@@ -64,7 +64,7 @@ func (n *Node) setXAttr(context *fuse.Context, cAttr string, cData []byte, flags
}
func (n *Node) removeXAttr(cAttr string) (errno syscall.Errno) {
- dirfd, cName, errno := n.prepareAtSyscall("")
+ dirfd, cName, errno := n.prepareAtSyscallMyself()
if errno != 0 {
return
}
@@ -86,7 +86,7 @@ func (n *Node) removeXAttr(cAttr string) (errno syscall.Errno) {
}
func (n *Node) listXAttr() (out []string, errno syscall.Errno) {
- dirfd, cName, errno := n.prepareAtSyscall("")
+ dirfd, cName, errno := n.prepareAtSyscallMyself()
if errno != 0 {
return
}
diff --git a/internal/fusefrontend/node_xattr_linux.go b/internal/fusefrontend/node_xattr_linux.go
index 9698282..212d4e1 100644
--- a/internal/fusefrontend/node_xattr_linux.go
+++ b/internal/fusefrontend/node_xattr_linux.go
@@ -17,7 +17,7 @@ func filterXattrSetFlags(flags int) int {
}
func (n *Node) getXAttr(cAttr string) (out []byte, errno syscall.Errno) {
- dirfd, cName, errno := n.prepareAtSyscall("")
+ dirfd, cName, errno := n.prepareAtSyscallMyself()
if errno != 0 {
return
}
@@ -32,7 +32,7 @@ func (n *Node) getXAttr(cAttr string) (out []byte, errno syscall.Errno) {
}
func (n *Node) setXAttr(context *fuse.Context, cAttr string, cData []byte, flags uint32) (errno syscall.Errno) {
- dirfd, cName, errno := n.prepareAtSyscall("")
+ dirfd, cName, errno := n.prepareAtSyscallMyself()
if errno != 0 {
return
}
@@ -44,7 +44,7 @@ func (n *Node) setXAttr(context *fuse.Context, cAttr string, cData []byte, flags
}
func (n *Node) removeXAttr(cAttr string) (errno syscall.Errno) {
- dirfd, cName, errno := n.prepareAtSyscall("")
+ dirfd, cName, errno := n.prepareAtSyscallMyself()
if errno != 0 {
return
}
@@ -55,7 +55,7 @@ func (n *Node) removeXAttr(cAttr string) (errno syscall.Errno) {
}
func (n *Node) listXAttr() (out []string, errno syscall.Errno) {
- dirfd, cName, errno := n.prepareAtSyscall("")
+ dirfd, cName, errno := n.prepareAtSyscallMyself()
if errno != 0 {
return
}
diff --git a/internal/fusefrontend/root_node.go b/internal/fusefrontend/root_node.go
index af4407e..ab0cdcd 100644
--- a/internal/fusefrontend/root_node.go
+++ b/internal/fusefrontend/root_node.go
@@ -61,11 +61,16 @@ func NewRootNode(args Args, c *contentenc.ContentEnc, n *nametransform.NameTrans
if len(args.Exclude) > 0 {
tlog.Warn.Printf("Forward mode does not support -exclude")
}
+ ivLen := nametransform.DirIVLen
+ if args.PlaintextNames {
+ ivLen = 0
+ }
rn := &RootNode{
args: args,
nameTransform: n,
contentEnc: c,
inoMap: inomap.New(),
+ dirCache: dirCache{ivLen: ivLen},
}
// In `-sharedstorage` mode we always set the inode number to zero.
// This makes go-fuse generate a new inode number for each lookup.
@@ -122,15 +127,15 @@ func (rn *RootNode) reportMitigatedCorruption(item string) {
}
}
-// isFiltered - check if plaintext "path" should be forbidden
+// isFiltered - check if plaintext file "child" should be forbidden
//
// Prevents name clashes with internal files when file names are not encrypted
-func (rn *RootNode) isFiltered(path string) bool {
+func (rn *RootNode) isFiltered(child string) bool {
if !rn.args.PlaintextNames {
return false
}
// gocryptfs.conf in the root directory is forbidden
- if path == configfile.ConfDefaultName {
+ if child == configfile.ConfDefaultName {
tlog.Info.Printf("The name /%s is reserved when -plaintextnames is used\n",
configfile.ConfDefaultName)
return true
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-10 19:29:22 +0000