Allow about: modules to just set a flag to force script execution to be allowed

for particular about: URIs, instead of hardcoding checks in the security
manager.  Bug 341313, r=darin, sr=jst

caps/src/nsScriptSecurityManager.cpp

@@ -1619,19 +1619,28 @@ nsScriptSecurityManager::CanExecuteScripts(JSContext* cx,
     }
 
     // OK, the docshell doesn't have script execution explicitly disabled.
-    // Check whether our URI is "about:".  If it is, we need to allow JS to
-    // run...  In this case, don't apply the JS enabled pref or policies.
+    // Check whether our URI is an "about:" URI that allows scripts.  If it is,
+    // we need to allow JS to run.  In this case, don't apply the JS enabled
+    // pref or policies.  On failures, just press on and don't do this special
+    // case.
     nsCOMPtr<nsIURI> principalURI;
     aPrincipal->GetURI(getter_AddRefs(principalURI));
     if (principalURI)
     {
-        nsCAutoString spec;
-        principalURI->GetSpec(spec);
-        if (spec.EqualsLiteral("about:") ||
-            StringBeginsWith(spec, NS_LITERAL_CSTRING("about:neterror?")))
-        {
-            *result = PR_TRUE;
-            return NS_OK;              
+        PRBool isAbout;
+        rv = principalURI->SchemeIs("about", &isAbout);
+        if (NS_SUCCEEDED(rv) && isAbout) {
+            nsCOMPtr<nsIAboutModule> module;
+            rv = NS_GetAboutModule(principalURI, getter_AddRefs(module));
+            if (NS_SUCCEEDED(rv)) {
+                PRUint32 flags;
+                rv = module->GetURIFlags(principalURI, &flags);
+                if (NS_SUCCEEDED(rv) &&
+                    (flags & nsIAboutModule::ALLOW_SCRIPT)) {
+                    *result = PR_TRUE;
+                    return NS_OK;              
+                }
+            }
         }
     }
 

netwerk/protocol/about/public/nsAboutProtocolUtils.h

@@ -37,6 +37,7 @@
 #include "nsIURI.h"
 #include "nsString.h"
 #include "nsReadableUtils.h"
+#include "nsIAboutModule.h"
 
 inline nsresult
 NS_GetAboutModuleName(nsIURI *aAboutURI, nsCString& aModule)
@@ -62,3 +63,18 @@ NS_GetAboutModuleName(nsIURI *aAboutURI, nsCString& aModule)
     ToLowerCase(aModule);
     return NS_OK;
 }
+
+inline nsresult
+NS_GetAboutModule(nsIURI *aAboutURI, nsIAboutModule** aModule)
+{
+  NS_PRECONDITION(aAboutURI, "Must have URI");
+
+  nsCAutoString contractID;
+  nsresult rv = NS_GetAboutModuleName(aAboutURI, contractID);
+  if (NS_FAILED(rv)) return rv;
+
+  // look up a handler to deal with "what"
+  contractID.Insert(NS_LITERAL_CSTRING(NS_ABOUT_MODULE_CONTRACTID_PREFIX), 0);
+
+  return CallGetService(contractID.get(), aModule);
+}

netwerk/protocol/about/public/nsIAboutModule.idl

@@ -58,6 +58,12 @@ interface nsIAboutModule : nsISupports
      */
     const unsigned long URI_SAFE_FOR_UNTRUSTED_CONTENT = (1 << 0);
 
+    /**
+     * A flag that indicates whether script should be enabled for the
+     * given about: URI even if it's disabled in general.
+     */
+    const unsigned long ALLOW_SCRIPT = (1 << 1);
+
     /**
      * A method to get the flags that apply to a given about: URI.  The URI
      * passed in is guaranteed to be one of the URIs that this module

netwerk/protocol/about/src/nsAboutProtocolHandler.cpp

@@ -105,7 +105,7 @@ nsAboutProtocolHandler::NewURI(const nsACString &aSpec,
     PRBool isSafe = PR_FALSE;
     
     nsCOMPtr<nsIAboutModule> aboutMod;
-    rv = GetModuleForURI(url, getter_AddRefs(aboutMod));
+    rv = NS_GetAboutModule(url, getter_AddRefs(aboutMod));
     if (NS_SUCCEEDED(rv)) {
         // The standard return case
         PRUint32 flags;
@@ -147,7 +147,7 @@ nsAboutProtocolHandler::NewChannel(nsIURI* uri, nsIChannel* *result)
 
     // about:what you ask?
     nsCOMPtr<nsIAboutModule> aboutMod;
-    nsresult rv = GetModuleForURI(uri, getter_AddRefs(aboutMod));
+    nsresult rv = NS_GetAboutModule(uri, getter_AddRefs(aboutMod));
     if (NS_SUCCEEDED(rv)) {
         // The standard return case:
         return aboutMod->NewChannel(uri, result);
@@ -172,24 +172,6 @@ nsAboutProtocolHandler::AllowPort(PRInt32 port, const char *scheme, PRBool *_ret
     return NS_OK;
 }
 
-////////////////////////////////////////////////////////////////////////////////
-/* static */
-nsresult
-nsAboutProtocolHandler::GetModuleForURI(nsIURI* uri, nsIAboutModule** module)
-{
-    NS_PRECONDITION(uri, "Must have URI");
-
-    nsresult rv;
-    nsCAutoString contractID;
-    rv = NS_GetAboutModuleName(uri, contractID);
-    if (NS_FAILED(rv)) return rv;
-
-    // look up a handler to deal with "what"
-    contractID.Insert(NS_LITERAL_CSTRING(NS_ABOUT_MODULE_CONTRACTID_PREFIX), 0);
-
-    return CallGetService(contractID.get(), module);
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 // Safe about protocol handler impl
 

netwerk/protocol/about/src/nsAboutProtocolHandler.h

@@ -54,9 +54,6 @@ public:
     // nsAboutProtocolHandler methods:
     nsAboutProtocolHandler() {}
     virtual ~nsAboutProtocolHandler() {}
-
-protected:
-    static nsresult GetModuleForURI(nsIURI* uri, nsIAboutModule** module);
 };
 
 class nsSafeAboutProtocolHandler : public nsIProtocolHandler

netwerk/protocol/about/src/nsAboutRedirector.cpp

@@ -51,6 +51,9 @@ struct RedirEntry {
     const char* id;
     const char* url;
     PRBool dropChromePrivs; // if PR_TRUE, the page will not have chrome privileges
+    PRBool allowScripts;  // if PR_TRUE, the page will be able to run scripts
+                          // even if script is generally disabled and it
+                          // doesn't have chrome privileges.  Use sparingly!
 };
 
 /*
@@ -61,16 +64,17 @@ struct RedirEntry {
   before adding new map entries with dropChromePrivs == PR_FALSE.
  */
 static RedirEntry kRedirMap[] = {
-    { "credits", "http://www.mozilla.org/credits/", PR_TRUE },
-    { "mozilla", "chrome://global/content/mozilla.xhtml", PR_TRUE },
-    { "plugins", "chrome://global/content/plugins.html", PR_FALSE },
-    { "config", "chrome://global/content/config.xul", PR_FALSE },
-    { "logo", "chrome://global/content/logo.gif", PR_TRUE },
-    { "buildconfig", "chrome://global/content/buildconfig.html", PR_TRUE },
-    { "license", "chrome://global/content/license.html", PR_TRUE },
-    { "licence", "chrome://global/content/license.html", PR_TRUE },
-    { "about", "chrome://global/content/aboutAbout.html", PR_FALSE },
-    { "neterror", "chrome://global/content/netError.xhtml", PR_TRUE }
+    { "credits", "http://www.mozilla.org/credits/", PR_TRUE, PR_FALSE },
+    { "mozilla", "chrome://global/content/mozilla.xhtml", PR_TRUE, PR_FALSE },
+    { "plugins", "chrome://global/content/plugins.html", PR_FALSE, PR_FALSE },
+    { "config", "chrome://global/content/config.xul", PR_FALSE, PR_FALSE },
+    { "logo", "chrome://global/content/logo.gif", PR_TRUE, PR_FALSE },
+    { "buildconfig", "chrome://global/content/buildconfig.html",
+      PR_TRUE, PR_FALSE },
+    { "license", "chrome://global/content/license.html", PR_TRUE, PR_FALSE },
+    { "licence", "chrome://global/content/license.html", PR_TRUE, PR_FALSE },
+    { "about", "chrome://global/content/aboutAbout.html", PR_FALSE, PR_FALSE },
+    { "neterror", "chrome://global/content/netError.xhtml", PR_TRUE, PR_TRUE }
 };
 static const int kRedirTotal = NS_ARRAY_LENGTH(kRedirMap);
 
@@ -145,6 +149,9 @@ nsAboutRedirector::GetURIFlags(nsIURI *aURI, PRUint32 *result)
         {
             *result = kRedirMap[i].dropChromePrivs ?
                 nsIAboutModule::URI_SAFE_FOR_UNTRUSTED_CONTENT : 0;
+            if (kRedirMap[i].allowScripts) {
+                *result |= nsIAboutModule::ALLOW_SCRIPT;
+            }
             return NS_OK;
         }
     }

xpfe/appshell/src/nsAbout.cpp

@@ -80,7 +80,7 @@ nsAbout::NewChannel(nsIURI *aURI, nsIChannel **result)
 NS_IMETHODIMP
 nsAbout::GetURIFlags(nsIURI *aURI, PRUint32 *result)
 {
-    *result = 0;
+    *result = nsIAboutModule::ALLOW_SCRIPT;
     return NS_OK;
 }