Refactor OS X sandbox processing and audit sandbox files

content/common/common.sb

 ;;
 ;; Copyright (c) 2012 The Chromium Authors. All rights reserved.
 ;; Use of this source code is governed by a BSD-style license that can be
 ;; found in the LICENSE file.
 ;;
 ; This configuration file isn't used on it's own, but instead implicitly
 ; included at the start of all other sandbox configuration files in Chrome.
 (version 1)
 
-; DISABLE_SANDBOX_DENIAL_LOGGING expands to syntax that turns off log message
-; printing on sandbox exceptions; this functionality only exists on 10.6. The
-; --enable-sandbox-logging flag or system versions <10.6 cause this flag to
-; expand to an empty string. http://crbug.com/26621
-(deny default @DISABLE_SANDBOX_DENIAL_LOGGING@)
+; Helper function to check if a param is set to true.
+(define (param-true? str) (string=? (param str) "TRUE"))
+
+; Helper function to determine if a parameter is defined or not.
+(define (param-defined? str) (string? (param str)))
+
+; Define constants for all of the parameter strings passed in.
+(define disable-sandbox-denial-logging "DISABLE_SANDBOX_DENIAL_LOGGING")
+(define enable-logging "ENABLE_LOGGING")
+(define component-build-workaround "COMPONENT_BUILD_WORKAROUND")
+(define permitted-dir "PERMITTED_DIR")
+(define lion-or-later "LION_OR_LATER")
+(define homedir-as-literal "USER_HOMEDIR_AS_LITERAL")
+
+; Consumes a subpath and appends it to the user's homedir path.
+(define (user-homedir-path subpath) (string-append (param homedir-as-literal) subpath))
+
+; DISABLE_SANDBOX_DENIAL_LOGGING turns off log messages in the system log.
+(if (param-true? disable-sandbox-denial-logging)
+    (deny default (with no-log))
+    (deny default))
 
 ; Support for programmatically enabling verbose debugging.
-;ENABLE_LOGGING (debug deny)
+(if (param-true? enable-logging) (debug deny))
 
 ; Allow sending signals to self - http://crbug.com/20370
 (allow signal (target self))
 
 ; Needed for full-page-zoomed controls - http://crbug.com/11325
 (allow sysctl-read)
 
-; Each line is marked with the System version that needs it.
-; This profile is tested with the following system versions:
-;     10.5.6, 10.6
-
 ; Loading System Libraries.
 (allow file-read*
     (regex #"^/System/Library/Frameworks($|/)")
     (regex #"^/System/Library/PrivateFrameworks($|/)")
-    (regex #"^/System/Library/CoreServices($|/)"))  ; 10.5.6
+    (regex #"^/System/Library/CoreServices($|/)"))
 
-; Needed for IPC on 10.6
 (allow ipc-posix-shm)
 
 ; Allow direct access to /dev/urandom, similar to Linux/POSIX, to allow
 ; third party code (eg: bits of Adobe Flash and NSS) to function properly.
 (allow file-read-data file-read-metadata (literal "/dev/urandom"))
 
-; Component build workaround for a dyld bug, used on OS X <= 10.6.
 ; Enables reading file metadata for the Chrome bundle and its parent paths.
 ; http://crbug.com/127465
-@COMPONENT_BUILD_WORKAROUND@
+(if (and (param-defined? component-build-workaround)
+         (param-true? component-build-workaround))
+  (allow file-read-metadata ))