On Sunday, June 28, 2015 05:59:14 Linus Lüssing wrote:
I am not quite clear on what the patch does. It helps to support a feature that is yet to come (upcoming bridge integration) or improves the situation today ?
The former. It's not fixing or improving anything for the current implementation.
If this patch isn't doing anything (for now) maybe it should be merged when it becomes useful ?
+#if IS_ENABLED(CONFIG_IPV6)
case ETH_P_IPV6: return batadv_mcast_forw_mode_check_ipv6(bat_priv, skb, is_unsnoopable);
+#endif
default: return -EINVAL;
}
This hunk seems not really related to the patch itself ?
I think it's necessary for the new ipv6_mc_check_mld() which isn't there if building a kernel without any IPv6 support.
You may want to send a separate patch then ? This change seems unrelated to the rest.
By removing mcast v1 you effectively are breaking compatibility with all nodes running v1 and require everyone to upgrade to v2.
No, no v1 nodes are required to upgrade. v1 and v2 nodes are still able to communicate. v1 nodes (like any pre v1 node) might downgrade the mesh to a mcast-optimizations-disabled state for now though, yes.
I do understand that 'normal' packet exchange is not affected. However, the TVLVs were introduced with the intend of maintaining best possible compatibility with future versions. With the first tvlv version bump we already require upgrading everyone or compatibility is already broken ? Is there really nothing we can do ? v2 could at least be compatible to v1 ?
We cannot safely use the multicast optimizations with bridges if there are nodes which do not handle reports properly. The bump isn't needed for any packet changes but the internal, local behaviour of a node.
I haven't heard of anyone using the multicast optimization feature in practice yet (that is, a setup without bridges), so I think it is safe to do a version bump?
A version bump for a feature which does not do anything useful yet (see my initial question) ? How likely is it that we will need another version bump by the time this feature does become useful ?
Hm, good question :). Need to recheck, I vaguely remember having had issues with the IP header parsing due to unset skb network headers.
If it is related to this patch please add a comment. The change is non- obvious.
Cheers, Marek