2015-06-10 18:02:44

by Alexis Green

Subject: [PATCH] mac80211: Add missing case to PERR processing

When the nexthop is unable to resolve its own nexthop it will send back a
PERR with a zero target_sn. According to section 13.10.11.4.3 step b in the
2012 standard that perr should be forwarded and the associated mpath->sn
should be incremented. Neither one of those was happening whichis rather
bad because the originator was not told that packets are black holing.

Signed-off-by: Alexis Green <[email protected]>
CC: Jesse Jones <[email protected]>

---

diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c
index 3c7cf3c..28c18cb 100755
--- a/net/mac80211/mesh_hwmp.c
+++ b/net/mac80211/mesh_hwmp.c
@@ -736,9 +736,12 @@ static void hwmp_perr_frame_process(struct ieee80211_sub_if_data *sdata,
if (mpath->flags & MESH_PATH_ACTIVE &&
ether_addr_equal(ta, sta->sta.addr) &&
(!(mpath->flags & MESH_PATH_SN_VALID) ||
- SN_GT(target_sn, mpath->sn))) {
+ SN_GT(target_sn, mpath->sn) || target_sn == 0)) {
mpath->flags &= ~MESH_PATH_ACTIVE;
- mpath->sn = target_sn;
+ if (target_sn != 0)
+ mpath->sn = target_sn;
+ else
+ mpath->sn += 1;
spin_unlock_bh(&mpath->state_lock);
if (!ifmsh->mshcfg.dot11MeshForwarding)
goto endperr;

2015-06-17 08:55:44

by Johannes Berg

Subject: Re: [PATCH] mac80211: Add missing case to PERR processing

On Wed, 2015-06-10 at 11:02 -0700, Alexis Green wrote:
> When the nexthop is unable to resolve its own nexthop it will send back a
> PERR with a zero target_sn. According to section 13.10.11.4.3 step b in the
> 2012 standard that perr should be forwarded and the associated mpath->sn
> should be incremented. Neither one of those was happening whichis rather
> bad because the originator was not told that packets are black holing.

Applied.

johannes