# fix to VFS init called from self test

fixes #157
bitten again by the complex tree_shutdown code. now correctly pull rug
(memory) out from under the tree *after* it has emptied itself.

also add an 'am i initialized' indicator to VFS to allow multiple init
and also provide means of squelching the root-dir-set-multiple times
thing

This was SVN commit r4588.

source/lib/res/file/path.cpp

@@ -138,6 +138,16 @@ LibError file_make_full_portable_path(const char* n_full_path, char* path)
 }
 
 
+// security check: only allow attempting to chdir once, so that malicious
+// code cannot circumvent the VFS checks that disallow access to anything
+// above the current directory (set here).
+// this routine is called early at startup, so any subsequent attempts
+// are likely bogus.
+// we provide for resetting this from the self-test to allow clean
+// re-init of the individual tests.
+static bool root_dir_established;
+
+
 // establish the root directory from <rel_path>, which is treated as
 // relative to the executable's directory (determined via argv[0]).
 // all relative file paths passed to this module will be based from
@@ -153,15 +163,9 @@ LibError file_make_full_portable_path(const char* n_full_path, char* path)
 // can only be called once, by design (see below). rel_path is trusted.
 LibError file_set_root_dir(const char* argv0, const char* rel_path)
 {
-	// security check: only allow attempting to chdir once, so that malicious
-	// code cannot circumvent the VFS checks that disallow access to anything
-	// above the current directory (set here).
-	// this routine is called early at startup, so any subsequent attempts
-	// are likely bogus.
-	static bool already_attempted;
-	if(already_attempted)
+	if(root_dir_established)
 		WARN_RETURN(ERR::ROOT_DIR_ALREADY_SET);
-	already_attempted = true;
+	root_dir_established = true;
 
 	// get full path to executable
 	char n_path[PATH_MAX];
@@ -193,6 +197,16 @@ LibError file_set_root_dir(const char* argv0, const char* rel_path)
 }
 
 
+void path_reset_root_dir()
+{
+	// see comment at root_dir_established.
+	debug_assert(root_dir_established);
+	n_root_dir[0] = '\0';
+	n_root_dir_len = 0;
+	root_dir_established = false;
+}
+
+
 //-----------------------------------------------------------------------------
 // storage for path strings
 //-----------------------------------------------------------------------------

source/lib/res/file/path.h

@@ -58,6 +58,16 @@ extern bool path_is_atom_fn(const char* fn);
 
 extern const char* file_get_random_name();
 
+
+/**
+ * reset root directory that was previously established via file_set_root_dir.
+ *
+ * this function avoids the security complaint that would be raised if
+ * file_set_root_dir is called twice; it is provided for the
+ * legitimate application of a self-test setUp()/tearDown().
+ **/
+extern void path_reset_root_dir();
+
 // note: other functions are declared directly in the public file.h header.
 
 

source/lib/res/file/tests/test_archive_builder.h

@@ -97,6 +97,7 @@ public:
 		vfs_shutdown();
 		dir_delete("archivetest");
 		file_delete(archive_fn);
+		path_reset_root_dir();
 	}
 
 	void test_create_archive_with_random_files()
@@ -126,4 +127,12 @@ public:
 		}
 		TS_ASSERT_OK(archive_close(ha));
 	}
+
+	void test_multiple_init_shutdown()
+	{
+		vfs_init();
+		vfs_shutdown();
+		vfs_init();
+		vfs_shutdown();
+	}
 };

source/lib/res/file/vfs.cpp

@@ -738,12 +738,13 @@ void vfs_display()
 }
 
 
-// allow init more complicated than merely calling mount_init by
-// splitting this into a separate function.
-static void vfs_init_once(void)
+static enum VfsInitState
 {
-	mount_init();
+	VFS_BEFORE_INIT,
+	VFS_INITIALIZED,
+	VFS_SHUTDOWN
 }
+vfs_init_state;
 
 // make the VFS tree ready for use. must be called before all other
 // functions below, barring explicit mentions to the contrary.
@@ -754,14 +755,21 @@ static void vfs_init_once(void)
 // is necessary anyway and this way is simpler/easier to maintain.
 void vfs_init()
 {
+	debug_assert(vfs_init_state == VFS_BEFORE_INIT || vfs_init_state == VFS_SHUTDOWN);
+
 	stats_vfs_init_start();
-	static pthread_once_t once = PTHREAD_ONCE_INIT;
-	WARN_ERR(pthread_once(&once, vfs_init_once));
+	mount_init();
 	stats_vfs_init_finish();
+
+	vfs_init_state = VFS_INITIALIZED;
 }
 
 void vfs_shutdown()
 {
+	debug_assert(vfs_init_state == VFS_INITIALIZED);
+
 	trace_shutdown();
 	mount_shutdown();
+
+	vfs_init_state = VFS_SHUTDOWN;
 }

source/lib/res/file/vfs_tree.cpp

@@ -540,6 +540,8 @@ void tree_shutdown()
 	// freeing memory they hold.
 	tree_root->clearR();
 
+	tree_root_shutdown();
+
 	// free memory underlying the nodes themselves.
 	node_shutdown();
 }