Messages in this thread | | | Date | Mon, 4 Aug 2008 14:48:07 +0200 | From | Thomas Petazzoni <> | Subject | Re: [patch 4/4] Configure out IGMP support |
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Le Fri, 01 Aug 2008 20:41:55 +0100, David Woodhouse <dwmw2@infradead.org> a écrit :
> The config option probably lives in net/Kconfig, not init/Kconfig.
Yes, it could. But AFAIK, until now, all CONFIG_EMBEDDED-related options have been put in init/Kconfig. But if it's preferred, I can of course change the patch to move the config option to net/Kconfig.
> And please could you make it clear how this interacts with > IP_MULTICAST? > > We already have a CONFIG_IP_MULTICAST option, for which the help text > says "For more people, it's safe to say N'. And I think it defaults to > that too. What more does CONFIG_IGMP remove? It's not made clear by > the help text.
The interaction of IGMP support with CONFIG_IP_MULTICAST is fairly unclear to me.
A large portion of igmp.c is already under #ifdef CONFIG_IP_MULTICAST: all the igmp_*() functions, amongst which is igmp_rcv(), referenced in igmp_protocol in net/ipv4/af_inet.c, which is compiled-out when !CONFIG_IP_MULTICAST.
All the proc-related code at the end of the file is only conditionnaly compiled on CONFIG_PROC_FS, but seems to in fact be only used if both CONFIG_IP_MULTICAST and CONFIG_PROC_FS are selected: igmp_mc_proc_init() in net/ipv4/ip_output.c is only called when CONFIG_IP_MULTICAST and CONFIG_PROC_FS are selected.
Besides that, it's unclear to me why the ip_mc_*() functions are useful when !CONFIG_IP_MULTICAST, but I'm probably missing something. They are used to implement setsockopt-operations related to multicast, hooks for the routing code to handle multicast-related traffic, etc.
Sincerly,
Thomas -- Thomas Petazzoni, Free Electrons Kernel, drivers and embedded Linux development, consulting, training and support. http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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