[PPAPI] It is now possible to pass filesystems from JavaScript to NaCl modules.

content/browser/renderer_host/pepper/pepper_renderer_connection.cc

Index: content/browser/renderer_host/pepper/pepper_renderer_connection.cc
diff --git a/content/browser/renderer_host/pepper/pepper_renderer_connection.cc b/content/browser/renderer_host/pepper/pepper_renderer_connection.cc
index e4c8aa71dc11f3b39f042c320407ac70383cc7f6..35726b0968a6135e7b92be8209e21057a1e9976a 100644
--- a/content/browser/renderer_host/pepper/pepper_renderer_connection.cc
+++ b/content/browser/renderer_host/pepper/pepper_renderer_connection.cc
@@ -10,6 +10,7 @@
 #include "content/common/pepper_renderer_instance_data.h"
 #include "content/common/view_messages.h"
 #include "content/browser/renderer_host/pepper/pepper_file_ref_host.h"
+#include "content/browser/renderer_host/pepper/pepper_file_system_browser_host.h"
 #include "content/public/browser/content_browser_client.h"
 #include "content/public/common/content_client.h"
 #include "ipc/ipc_message_macros.h"
@@ -97,24 +98,37 @@ void PepperRendererConnection::OnMsgCreateResourceHostsFromHost(
     DLOG(ERROR) << "Invalid plugin process ID.";
   } else {
     for (size_t i = 0; i < nested_msgs.size(); ++i) {
+      const IPC::Message& nested_msg = nested_msgs[i];
       // FileRef_CreateExternal is only permitted from the renderer. Because of
       // this, we handle this message here and not in
       // content_browser_pepper_host_factory.cc.
       scoped_ptr<ppapi::host::ResourceHost> resource_host;
       if (host->IsValidInstance(instance)) {
-        if (nested_msgs[i].type() == PpapiHostMsg_FileRef_CreateExternal::ID) {
+        if (nested_msg.type() == PpapiHostMsg_FileRef_CreateExternal::ID) {
           base::FilePath external_path;
           if (ppapi::UnpackMessage<PpapiHostMsg_FileRef_CreateExternal>(
-              nested_msgs[i], &external_path)) {
+              nested_msg, &external_path)) {
             resource_host.reset(new PepperFileRefHost(
                 host, instance, params.pp_resource(), external_path));
           }
+        } else if (nested_msg.type() == PpapiHostMsg_FileSystem_CreateFromRenderer::ID) {

[raymes, 2013/10/11 04:02:24]

nit: long line

[Matt Giuca, 2013/10/15 00:25:16]

Done.

+          std::string root_url;
+          PP_FileSystemType file_system_type;
+          if (ppapi::UnpackMessage<PpapiHostMsg_FileSystem_CreateFromRenderer>(
+              nested_msg, &root_url, &file_system_type)) {
+            resource_host.reset(
+                new PepperFileSystemBrowserHost(host,
+                                                instance,
+                                                params.pp_resource(),
+                                                GURL(root_url),
+                                                file_system_type));

[dmichael (off chromium), 2013/10/11 19:21:36]

Hmm. This could actually go in to content_browser_pepper_host_factory.cc.
FileRef_CreateExternal is special not only because it's created from the
renderer, but also because it could be a security vulnerability if it could be
faked from the plugin.

But I can see the logic in putting it here. If we leave it here, maybe you can
add a comment similar to the one at 102, or something.

[Matt Giuca, 2013/10/17 09:17:58]

Done (comment).

Actually, I think we really don't want to allow the plugin to send this message.
We don't want to trust the root URL supplied by the plugin.

[dmichael (off chromium), 2013/10/17 17:36:11]

Ah, good point!

+          }
         }
       }
 
       if (!resource_host.get()) {
         resource_host = host->GetPpapiHost()->CreateResourceHost(
-            params, instance, nested_msgs[i]);
+            params, instance, nested_msg);
       }
 
       if (resource_host.get()) {