ppapi: PPB_VpnProvider: Implement Resource Host

ppapi/proxy/vpn_provider_resource.cc

Index: ppapi/proxy/vpn_provider_resource.cc
diff --git a/ppapi/proxy/vpn_provider_resource.cc b/ppapi/proxy/vpn_provider_resource.cc
index bf960bdf8075f8a56d1f9e866e6b1498df4afdfb..2d2f94de6fc8d0492cd67726273f09a89faddca4 100644
--- a/ppapi/proxy/vpn_provider_resource.cc
+++ b/ppapi/proxy/vpn_provider_resource.cc
@@ -23,7 +23,9 @@ VpnProviderResource::VpnProviderResource(Connection connection,
       send_packet_callback_(nullptr),
       receive_packet_callback_(nullptr),
       receive_packet_callback_var_(nullptr),
-      bound_(false) {}
+      bound_(false) {
+  SendCreate(BROWSER, PpapiHostMsg_VpnProvider_Create());
+}
 
 VpnProviderResource::~VpnProviderResource() {}
 
@@ -34,7 +36,15 @@ thunk::PPB_VpnProvider_API* VpnProviderResource::AsPPB_VpnProvider_API() {
 void VpnProviderResource::OnReplyReceived(
     const ResourceMessageReplyParams& params,
     const IPC::Message& msg) {
-  PluginResource::OnReplyReceived(params, msg);
+  PPAPI_BEGIN_MESSAGE_MAP(VpnProviderResource, msg)
+    PPAPI_DISPATCH_PLUGIN_RESOURCE_CALL(PpapiPluginMsg_VpnProvider_OnUnbind,
+                                        OnPluginMsgOnUnbindReceived)
+    PPAPI_DISPATCH_PLUGIN_RESOURCE_CALL(
+        PpapiPluginMsg_VpnProvider_OnPacketReceived,
+        OnPluginMsgOnPacketReceived)
+    PPAPI_DISPATCH_PLUGIN_RESOURCE_CALL_UNHANDLED(
+        PluginResource::OnReplyReceived(params, msg))
+  PPAPI_END_MESSAGE_MAP()
 }
 
 int32_t VpnProviderResource::Bind(
@@ -51,7 +61,14 @@ int32_t VpnProviderResource::Bind(
   if (!configuration_name_var)
     return PP_ERROR_BADARGUMENT;
 
-  return PP_ERROR_NOTSUPPORTED;
+  bind_callback_ = callback;
+
+  Call<PpapiPluginMsg_VpnProvider_BindReply>(
+      BROWSER, PpapiHostMsg_VpnProvider_Bind(configuration_id_var->value(),
+                                             configuration_name_var->value()),
+      base::Bind(&VpnProviderResource::OnPluginMsgBindReply, this));
+
+  return PP_OK_COMPLETIONPENDING;
 }
 
 int32_t VpnProviderResource::SendPacket(
@@ -86,11 +103,18 @@ int32_t VpnProviderResource::DoSendPacket(const PP_Var& packet, uint32_t id) {
   if (!packet_arraybuffer.get())
     return PP_ERROR_BADARGUMENT;
 
-  char* packet_pointer = static_cast<char*>(packet_arraybuffer->Map());
   uint32_t packet_size = packet_arraybuffer->ByteLength();
+  if (packet_size > send_packet_buffer_->GetMaxPacketSize())
+    return PP_ERROR_MESSAGE_TOO_BIG;

[bbudge, 2016/06/23 18:10:23]

It's fine to check this to help plugin writers, but it doesn't add to security
as malicious plugins can bypass it.

[adrian.belgun, 2016/06/24 13:19:37]

How can it be bypassed? When the plugin will call SendPacket() with bigger
messages, the message will be rejected before being written to the buffer.

+
+  char* packet_pointer = static_cast<char*>(packet_arraybuffer->Map());
   memcpy(send_packet_buffer_->GetBuffer(id), packet_pointer, packet_size);
   packet_arraybuffer->Unmap();
 
+  Call<PpapiPluginMsg_VpnProvider_SendPacketReply>(
+      BROWSER, PpapiHostMsg_VpnProvider_SendPacket(packet_size, id),
+      base::Bind(&VpnProviderResource::OnPluginMsgSendPacketReply, this));
+
   return PP_OK;
 }
 
@@ -132,7 +156,9 @@ void VpnProviderResource::OnPluginMsgOnPacketReceived(
     const ResourceMessageReplyParams& params,
     uint32_t packet_size,
     uint32_t id) {
-  if (!bound_) {
+  if (!bound_ || (packet_size > receive_packet_buffer_->GetMaxPacketSize())) {

[bbudge, 2016/06/23 18:10:23]

packet_size is coming from the browser so this should never happen. Perhaps a
DCHECK?

[adrian.belgun, 2016/06/24 13:19:37]

Done.

+    // Ignore packet and mark shared memory as available
+    Post(BROWSER, PpapiHostMsg_VpnProvider_OnPacketReceivedReply(id));
     return;
   }
 
@@ -143,6 +169,9 @@ void VpnProviderResource::OnPluginMsgOnPacketReceived(
                                                                packet_pointer));
   received_packets_.push(packet_var);
 
+  // Mark shared memory as available for next packet
+  Post(BROWSER, PpapiHostMsg_VpnProvider_OnPacketReceivedReply(id));
+
   if (!TrackedCallback::IsPending(receive_packet_callback_) ||
       TrackedCallback::IsScheduledToRun(receive_packet_callback_)) {
     return;