On Thu, 2009-10-22 at 15:52 +0200, Jiri Pirko wrote:

This helpers should be used by network drivers to access to netdev
multicast lists.

[...]

+static inline void netdev_mc_walk(struct net_device *dev,
+				  void (*func)(void *, unsigned char *),
+				  void *data)
+{
+	struct dev_addr_list *mclist;
+	int i;
+
+	for (i = 0, mclist = dev->mc_list; mclist && i < dev->mc_count;
+	     i++, mclist = mclist->next)
+		func(data, mclist->dmi_addr);
+}

[...]

We usually implement iteration as macros so that any context doesn't
have to be squeezed through a single untyped (void *) variable.  A macro
for this would look something like:

#define netdev_for_each_mc_addr(dev, addr)						\
	for (addr = (dev)->mc_list ? (dev)->mc_list->dmi_addr : NULL;			\
	     addr;									\
	     addr = (container_of(addr, struct dev_addr_list, dmi_addr)->next ?		\
		     container_of(addr, struct dev_addr_list, dmi_addr)->next->dmi_addr : \
		     NULL))

Once you change the list type this can presumably be made less ugly.

Ben.

-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.