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 alessandro@mediaspot.net Signed-off-by: Simon Wunderlich sw@simonwunderlich.de
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