On Tuesday 25 August 2015 11:59:01 Antonio Quartulli wrote: > On 21/08/15 17:15, Simon Wunderlich wrote: > > If the local representation of the global TT table of one originator has > > more VLAN entries than the respective TT update, there is some > > inconsistency present. By detecting and reporting this inconsistency, > > the global table gets updated and the excess VLAN will get removed in > > the process. > > > > Reported-by: Alessandro Bolletta <[email protected]> > > Signed-off-by: Simon Wunderlich <[email protected]> > > --- > > > > net/batman-adv/translation-table.c | 21 +++++++++++++++++++++ > > 1 file changed, 21 insertions(+) > > > > diff --git a/net/batman-adv/translation-table.c > > b/net/batman-adv/translation-table.c index dced2da..1adb72e 100644 > > --- a/net/batman-adv/translation-table.c > > +++ b/net/batman-adv/translation-table.c > > @@ -2392,6 +2392,7 @@ static bool batadv_tt_global_check_crc(struct > > batadv_orig_node *orig_node,> > > struct batadv_tvlv_tt_vlan_data *tt_vlan_tmp; > > struct batadv_orig_node_vlan *vlan; > > uint32_t crc; > > > > + bool found; > > > > int i; > > > > /* check if each received CRC matches the locally stored one */ > > > > @@ -2418,6 +2419,26 @@ static bool batadv_tt_global_check_crc(struct > > batadv_orig_node *orig_node,> > > return false; > > > > } > > > > + /* check if any excess VLANs exist locally for the originator > > + * which are not mentioned in the TVLV from the originator. > > + */ > > + rcu_read_lock(); > > + list_for_each_entry_rcu(vlan, &orig_node->vlan_list, list) { > > + found = false; > > + > > + for (i = 0; i < num_vlan; i++) { > > + tt_vlan_tmp = tt_vlan + i; > > + if (ntohs(tt_vlan_tmp->vid) == vlan->vid) { > > + found = true; > > + break; > > + } > > + } > > + > > + if (!found) > > + return false; > > + } > > + rcu_read_unlock(); > > + > > NAK. > > we already do this check slightly above in this function with the > following code: > > 2426 vlan = batadv_orig_node_vlan_get(orig_node, > 2427 > ntohs(tt_vlan_tmp->vid)); > 2428 if (!vlan) > 2429 return false; > > batadv_orig_node_vlan_get() returns NULL if we don't know this VLAN for > that Originator, therefore the CRC check fails here.
That's right, however it only sweeps through the VLANs announced within the
TT-TVLV. However, my addition tries to check if there are any excess VLAN
locally which are NOT in that TT-TVLV. I think this patch doesn't take care of
that, or am I missing something?
For example, think of having VLAN 6 locally with a couple of global entries at
the originator, but the TT-TVLV only announces VLANs 3,4,5. Then the fact that
we also have VLAN 6 is not detected, and these (probably wrong) entries are
never cleaned up.
Thanks!
Simon
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