From b2ddf58e892c04f39a7fa78e7a74bb2e49634d8f Mon Sep 17 00:00:00 2001
From: Hardcore Sushi <hardcore.sushi@disroot.org>
Date: Tue, 19 Apr 2022 20:22:20 +0200
Subject: [PATCH] Return an error if the volume is already closed

---
 common_ops.go | 10 ++++++++--
 directory.go  | 15 ++++++++++++---
 file.go       | 35 ++++++++++++++++++++++++++++-------
 volume.go     |  5 ++++-
 4 files changed, 52 insertions(+), 13 deletions(-)

diff --git a/common_ops.go b/common_ops.go
index a2d9f27..0d96aa5 100644
--- a/common_ops.go
+++ b/common_ops.go
@@ -11,7 +11,10 @@ import (
 
 //export gcf_get_attrs
 func gcf_get_attrs(sessionID int, relPath string) (uint64, int64, bool) {
-	volume := OpenedVolumes[sessionID]
+	volume, ok := OpenedVolumes[sessionID]
+	if !ok {
+		return 0, 0, false
+	}
 	dirfd, cName, err := volume.prepareAtSyscall(relPath)
 	if err != nil {
 		return 0, 0, false
@@ -32,7 +35,10 @@ func gcf_get_attrs(sessionID int, relPath string) (uint64, int64, bool) {
 // libgocryptfs: using Renameat instead of Renameat2 to support older kernels
 //export gcf_rename
 func gcf_rename(sessionID int, oldPath string, newPath string) bool {
-	volume := OpenedVolumes[sessionID]
+	volume, ok := OpenedVolumes[sessionID]
+	if !ok {
+		return false
+	}
 	dirfd, cName, err := volume.prepareAtSyscall(oldPath)
 	if err != nil {
 		return false
diff --git a/directory.go b/directory.go
index 6a7145f..30259f8 100644
--- a/directory.go
+++ b/directory.go
@@ -40,7 +40,10 @@ func mkdirWithIv(dirfd int, cName string, mode uint32) error {
 
 //export gcf_list_dir
 func gcf_list_dir(sessionID int, dirName string) (*C.char, *C.int, C.int) {
-	volume := OpenedVolumes[sessionID]
+	volume, ok := OpenedVolumes[sessionID]
+	if !ok {
+		return nil, nil, 0
+	}
 	parentDirFd, cDirName, err := volume.prepareAtSyscallMyself(dirName)
 	if err != nil {
 		return nil, nil, 0
@@ -116,7 +119,10 @@ func gcf_list_dir(sessionID int, dirName string) (*C.char, *C.int, C.int) {
 
 //export gcf_mkdir
 func gcf_mkdir(sessionID int, path string, mode uint32) bool {
-	volume := OpenedVolumes[sessionID]
+	volume, ok := OpenedVolumes[sessionID]
+	if !ok {
+		return false
+	}
 	dirfd, cName, err := volume.prepareAtSyscall(path)
 	if err != nil {
 		return false
@@ -187,7 +193,10 @@ func gcf_mkdir(sessionID int, path string, mode uint32) bool {
 
 //export gcf_rmdir
 func gcf_rmdir(sessionID int, relPath string) bool {
-	volume := OpenedVolumes[sessionID]
+	volume, ok := OpenedVolumes[sessionID]
+	if !ok {
+		return false
+	}
 	parentDirFd, cName, err := volume.prepareAtSyscall(relPath)
 	if err != nil {
 		return false
diff --git a/file.go b/file.go
index a91e354..d5be43e 100644
--- a/file.go
+++ b/file.go
@@ -369,7 +369,10 @@ func (volume *Volume) truncate(handleID int, newSize uint64) bool {
 
 //export gcf_open_read_mode
 func gcf_open_read_mode(sessionID int, path string) int {
-	volume := OpenedVolumes[sessionID]
+	volume, ok := OpenedVolumes[sessionID]
+	if !ok {
+		return -1
+	}
 	dirfd, cName, err := volume.prepareAtSyscallMyself(path)
 	if err != nil {
 		return -1
@@ -386,7 +389,10 @@ func gcf_open_read_mode(sessionID int, path string) int {
 
 //export gcf_open_write_mode
 func gcf_open_write_mode(sessionID int, path string, mode uint32) int {
-	volume := OpenedVolumes[sessionID]
+	volume, ok := OpenedVolumes[sessionID]
+	if !ok {
+		return -1
+	}
 	dirfd, cName, err := volume.prepareAtSyscall(path)
 	if err != nil {
 		return -1
@@ -419,7 +425,10 @@ func gcf_open_write_mode(sessionID int, path string, mode uint32) int {
 
 //export gcf_truncate
 func gcf_truncate(sessionID int, handleID int, offset uint64) bool {
-	volume := OpenedVolumes[sessionID]
+	volume, ok := OpenedVolumes[sessionID]
+	if !ok {
+		return false
+	}
 	return volume.truncate(handleID, offset)
 }
 
@@ -431,7 +440,10 @@ func gcf_read_file(sessionID, handleID int, offset uint64, dst_buff []byte) uint
 		return 0
 	}
 
-	volume := OpenedVolumes[sessionID]
+	volume, ok := OpenedVolumes[sessionID]
+	if !ok {
+		return 0
+	}
 	out, success := volume.doRead(handleID, dst_buff[:0], offset, uint64(length))
 	if !success {
 		return 0
@@ -448,14 +460,20 @@ func gcf_write_file(sessionID, handleID int, offset uint64, data []byte) uint32
 		return 0
 	}
 
-	volume := OpenedVolumes[sessionID]
+	volume, ok := OpenedVolumes[sessionID]
+	if !ok {
+		return 0
+	}
 	n, _ := volume.doWrite(handleID, data, offset)
 	return n
 }
 
 //export gcf_close_file
 func gcf_close_file(sessionID, handleID int) {
-	volume := OpenedVolumes[sessionID]
+	volume, ok := OpenedVolumes[sessionID]
+	if !ok {
+		return
+	}
 	f, ok := volume.file_handles[handleID]
 	if ok {
 		f.fd.Close()
@@ -469,7 +487,10 @@ func gcf_close_file(sessionID, handleID int) {
 
 //export gcf_remove_file
 func gcf_remove_file(sessionID int, path string) bool {
-	volume := OpenedVolumes[sessionID]
+	volume, ok := OpenedVolumes[sessionID]
+	if !ok {
+		return false
+	}
 	dirfd, cName, err := volume.prepareAtSyscall(path)
 	if err != nil {
 		return false
diff --git a/volume.go b/volume.go
index 4e79c81..108de9e 100644
--- a/volume.go
+++ b/volume.go
@@ -117,7 +117,10 @@ func gcf_init(rootCipherDir string, password, givenScryptHash, returnedScryptHas
 
 //export gcf_close
 func gcf_close(volumeID int) {
-	volume := OpenedVolumes[volumeID]
+	volume, ok := OpenedVolumes[volumeID]
+	if !ok {
+		return
+	}
 	volume.cryptoCore.Wipe()
 	for handleID := range volume.file_handles {
 		gcf_close_file(volumeID, handleID)