AllowBroadcast() is exposed to NaCl.

ppapi/api/private/ppb_udp_socket_private.idl

 /* 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 file defines the <code>PPB_UDPSocket_Private</code> interface.
  */
 
 label Chrome {
   M17 = 0.2,
-  M19 = 0.3
+  M19 = 0.3,
+  M23 = 0.4
+};
+
+[assert_size(4)]
+enum PP_UDPSocketFeature_Private {
+  // Allow the socket to share the local address to which socket will
+  // be bound with other processes. Value's type should be
+  // PP_VARTYPE_BOOL.
+  PP_UDPSOCKETFEATURE_ADDRESS_REUSE = 0,
+
+  // Allow sending and receiving packets sent to and from broadcast
+  // addresses. Value's type should be PP_VARTYPE_BOOL.
+  PP_UDPSOCKETFEATURE_BROADCAST = 1,
+
+  // Special value for counting the number of available
+  // features. Should not be passed to SetSocketFeature().
+  PP_UDPSOCKETFEATURE_COUNT = 2
 };
 
 interface PPB_UDPSocket_Private {
   /**
    * Creates a UDP socket resource.
    */
   PP_Resource Create([in] PP_Instance instance_id);
 
   /**
    * Determines if a given resource is a UDP socket.
    */
   PP_Bool IsUDPSocket([in] PP_Resource resource_id);
 
+  [version=0.4]

[brettw, 2012/08/20 04:34:45]

Can you provide documentation for this? In particular, what the callback means.
Does it mean the setting has taken effect? Do we really need the callback?
Normally these "set the setting" things don't need one. And it's also weird that
you can only set one setting at once (you could easily imagine wanting to set
several options on the socket).

[ygorshenin1, 2012/08/20 12:08:01]

Done.

Yes, callback means that the setting has effect. SetSocketFeature takes PP_Var
as value and callback so it's very general and can be easily extended. If some
complex check will be performed on the browser side, callback will be the only
way to pass back results.

I agree, that set once setting at once is weird, but in this case we can easily
verify compatibility of feature name and value type (and value). Also POSIX and
WS2 setsockopt takes option name, not or-ed combination of names.

On 2012/08/20 04:34:45, brettw wrote:

[brettw, 2012/08/20 17:55:15]

My weird that you can't set more than one at a time, I wasn't referring to
bitwise or-ing things, but rather that if you want to set two options, you have
to write a complex state machine since you can't set the second one until the
callback for the first one completes.

I don't think we should design this based on potential future extensibility. We
can always add a separate function or a new option setting function if we start
adding fancy checks that require callbacks.

[ygorshenin1, 2012/08/21 12:00:27]

OK, I'll delete callbacks.

On 2012/08/20 17:55:15, brettw wrote:

+  int32_t SetSocketFeature([in] PP_Resource udp_socket,
+                           [in] PP_UDPSocketFeature_Private name,
+                           [in] PP_Var value,
+                           [in] PP_CompletionCallback callback);
+
   /* Creates a socket and binds to the address given by |addr|. */
   int32_t Bind([in] PP_Resource udp_socket,
                [in] PP_NetAddress_Private addr,
                [in] PP_CompletionCallback callback);
 
   /* Returns the address that the socket has bound to.  A successful
    * call to Bind must be called first. Returns PP_FALSE if Bind
    * fails, or if Close has been called.
    */
   [version=0.3]
@@ skipping 22 matching lines @@
    */
   int32_t SendTo([in] PP_Resource udp_socket,
                  [in] str_t buffer,
                  [in] int32_t num_bytes,
                  [in] PP_NetAddress_Private addr,
                  [in] PP_CompletionCallback callback);
 
   /* Cancels all pending reads and writes, and closes the socket. */
   void Close([in] PP_Resource udp_socket);
 };