From 50d274f7f9e714a0fd8a51192a37fd90cb6fbb2d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Axel=20D=C3=B6rfler?= <axeld@pinc-software.de>
Date: Sat, 25 Oct 2014 19:31:15 +0200
Subject: [PATCH] fs_shell: Added missing new permission check function.

* Fixes the build.
---
 headers/private/fs_shell/fssh_api_wrapper.h  |  1 +
 headers/private/fs_shell/fssh_fs_interface.h |  4 ++-
 src/tools/fs_shell/vfs.cpp                   | 36 ++++++++++++++++++++
 3 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/headers/private/fs_shell/fssh_api_wrapper.h b/headers/private/fs_shell/fssh_api_wrapper.h
index f445fbaaf2..6a9e601ffa 100644
--- a/headers/private/fs_shell/fssh_api_wrapper.h
+++ b/headers/private/fs_shell/fssh_api_wrapper.h
@@ -938,6 +938,7 @@
 #define unremove_vnode				fssh_unremove_vnode
 #define get_vnode_removed			fssh_get_vnode_removed
 #define volume_for_vnode			fssh_volume_for_vnode
+#define check_access_permissions	fssh_check_access_permissions
 #define read_pages					fssh_read_pages
 #define write_pages					fssh_write_pages
 #define read_file_io_vec_pages		fssh_read_file_io_vec_pages
diff --git a/headers/private/fs_shell/fssh_fs_interface.h b/headers/private/fs_shell/fssh_fs_interface.h
index 6a0fdd0a2b..48dfce0545 100644
--- a/headers/private/fs_shell/fssh_fs_interface.h
+++ b/headers/private/fs_shell/fssh_fs_interface.h
@@ -361,7 +361,9 @@ extern fssh_status_t fssh_unremove_vnode(fssh_fs_volume *volume,
 extern fssh_status_t fssh_get_vnode_removed(fssh_fs_volume *volume,
 				fssh_vnode_id vnodeID, bool* removed);
 extern fssh_fs_volume* fssh_volume_for_vnode(fssh_fs_vnode *vnode);
-
+extern fssh_status_t fssh_check_access_permissions(int accessMode,
+				fssh_mode_t mode, fssh_gid_t nodeGroupID,
+				fssh_uid_t nodeUserID);
 
 extern fssh_status_t fssh_read_pages(int fd, fssh_off_t pos,
 				const struct fssh_iovec *vecs, fssh_size_t count,
diff --git a/src/tools/fs_shell/vfs.cpp b/src/tools/fs_shell/vfs.cpp
index 55a37b5dd4..9308a351da 100644
--- a/src/tools/fs_shell/vfs.cpp
+++ b/src/tools/fs_shell/vfs.cpp
@@ -2128,6 +2128,42 @@ fssh_volume_for_vnode(fssh_fs_vnode *_vnode)
 }
 
 
+extern "C" fssh_status_t
+fssh_check_access_permissions(int accessMode, fssh_mode_t mode,
+	fssh_gid_t nodeGroupID, fssh_uid_t nodeUserID)
+{
+	// get node permissions
+	int userPermissions = (mode & FSSH_S_IRWXU) >> 6;
+	int groupPermissions = (mode & FSSH_S_IRWXG) >> 3;
+	int otherPermissions = mode & FSSH_S_IRWXO;
+
+	// get the node permissions for this uid/gid
+	int permissions = 0;
+	fssh_uid_t uid = fssh_geteuid();
+
+	if (uid == 0) {
+		// user is root
+		// root has always read/write permission, but at least one of the
+		// X bits must be set for execute permission
+		permissions = userPermissions | groupPermissions | otherPermissions
+			| FSSH_S_IROTH | FSSH_S_IWOTH;
+		if (FSSH_S_ISDIR(mode))
+			permissions |= FSSH_S_IXOTH;
+	} else if (uid == nodeUserID) {
+		// user is node owner
+		permissions = userPermissions;
+	} else if (fssh_getegid() == nodeGroupID) {
+		// user is in owning group
+		permissions = groupPermissions;
+	} else {
+		// user is one of the others
+		permissions = otherPermissions;
+	}
+
+	return (accessMode & ~permissions) == 0 ? FSSH_B_OK : FSSH_B_NOT_ALLOWED;
+}
+
+
 //! Works directly on the host's file system
 extern "C" fssh_status_t
 fssh_read_pages(int fd, fssh_off_t pos, const fssh_iovec *vecs,