From 7ebfa46973aa239f79fbd4651ddeed5c92df45b2 Mon Sep 17 00:00:00 2001 From: Chun-Yeow Yeoh Date: Fri, 15 Jun 2012 10:20:02 +0800 Subject: [PATCH] mac80211: fix and improve mesh RANN processing This patch fixes the problem of dropping RANN element if the TTL is 1. If the received RANN element TTL is 1 or greater than 1, the RANN is processed. However, forwarding of received RANN element with TTL 1 or less is prohibited according to the standard. This is previously reported by Monthadar Al Jaberi. Besides, this patch also avoid the processing of unicast PREQ generation if the RANN element does not meet the acceptance criteria mentioned in Sec. 13.10.12.4.2 of IEEE Std. 802.11-2012. Reported-by: Monthadar Al Jaberi Signed-off-by: Chun-Yeow Yeoh Signed-off-by: Johannes Berg --- net/mac80211/mesh_hwmp.c | 43 +++++++++++++++++++++++++------------------ 1 file changed, 25 insertions(+), 18 deletions(-) diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c index bea5247..aed1821 100644 --- a/net/mac80211/mesh_hwmp.c +++ b/net/mac80211/mesh_hwmp.c @@ -771,11 +771,6 @@ static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata, bool root_is_gate; ttl = rann->rann_ttl; - if (ttl <= 1) { - ifmsh->mshstats.dropped_frames_ttl++; - return; - } - ttl--; flags = rann->rann_flags; root_is_gate = !!(flags & RANN_FLAG_IS_GATE); orig_addr = rann->rann_addr; @@ -812,37 +807,49 @@ static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata, } } + if (!(SN_LT(mpath->sn, orig_sn)) && + !(mpath->sn == orig_sn && metric < mpath->rann_metric)) { + rcu_read_unlock(); + return; + } + if ((!(mpath->flags & (MESH_PATH_ACTIVE | MESH_PATH_RESOLVING)) || (time_after(jiffies, mpath->last_preq_to_root + root_path_confirmation_jiffies(sdata)) || time_before(jiffies, mpath->last_preq_to_root))) && - !(mpath->flags & MESH_PATH_FIXED)) { + !(mpath->flags & MESH_PATH_FIXED) && (ttl != 0)) { mhwmp_dbg("%s time to refresh root mpath %pM", sdata->name, orig_addr); mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH); mpath->last_preq_to_root = jiffies; } - if ((SN_LT(mpath->sn, orig_sn) || (mpath->sn == orig_sn && - metric < mpath->rann_metric)) && ifmsh->mshcfg.dot11MeshForwarding) { + mpath->sn = orig_sn; + mpath->rann_metric = metric + metric_txsta; + mpath->is_root = true; + /* Recording RANNs sender address to send individually + * addressed PREQs destined for root mesh STA */ + memcpy(mpath->rann_snd_addr, mgmt->sa, ETH_ALEN); + + if (root_is_gate) + mesh_path_add_gate(mpath); + + if (ttl <= 1) { + ifmsh->mshstats.dropped_frames_ttl++; + rcu_read_unlock(); + return; + } + ttl--; + + if (ifmsh->mshcfg.dot11MeshForwarding) { mesh_path_sel_frame_tx(MPATH_RANN, flags, orig_addr, cpu_to_le32(orig_sn), 0, NULL, 0, broadcast_addr, hopcount, ttl, cpu_to_le32(interval), cpu_to_le32(metric + metric_txsta), 0, sdata); - mpath->sn = orig_sn; - mpath->rann_metric = metric + metric_txsta; - /* Recording RANNs sender address to send individually - * addressed PREQs destined for root mesh STA */ - memcpy(mpath->rann_snd_addr, mgmt->sa, ETH_ALEN); } - mpath->is_root = true; - - if (root_is_gate) - mesh_path_add_gate(mpath); - rcu_read_unlock(); } -- 2.7.4