From e3718a611470d311a92c60d4eb535270b49a7108 Mon Sep 17 00:00:00 2001 From: Linus Lüssing Date: Wed, 17 Jun 2020 09:30:33 +0200 Subject: cfg80211/mac80211: add mesh_param "mesh_nolearn" to skip path discovery MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently, before being able to forward a packet between two 802.11s nodes, both a PLINK handshake is performed upon receiving a beacon and then later a PREQ/PREP exchange for path discovery is performed on demand upon receiving a data frame to forward. When running a mesh protocol on top of an 802.11s interface, like batman-adv, we do not need the multi-hop mesh routing capabilities of 802.11s and usually set mesh_fwding=0. However, even with mesh_fwding=0 the PREQ/PREP path discovery is still performed on demand. Even though in this scenario the next hop PREQ/PREP will determine is always the direct 11s neighbor node. The new mesh_nolearn parameter allows to skip the PREQ/PREP exchange in this scenario, leading to a reduced delay, reduced packet buffering and simplifies HWMP in general. mesh_nolearn is still rather conservative in that if the packet destination is not a direct 11s neighbor, it will fall back to PREQ/PREP path discovery. For normal, multi-hop 802.11s mesh routing it is usually not advisable to enable mesh_nolearn as a transmission to a direct but distant neighbor might be worse than reaching that same node via a more robust / higher throughput etc. multi-hop path. Cc: Sven Eckelmann Cc: Simon Wunderlich Signed-off-by: Linus Lüssing Link: https://lore.kernel.org/r/20200617073034.26149-1-linus.luessing@c0d3.blue [fix nl80211 policy to range 0/1 only] Signed-off-by: Johannes Berg --- net/wireless/trace.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'net/wireless/trace.h') diff --git a/net/wireless/trace.h b/net/wireless/trace.h index b23cab016521..6e218a0acd4e 100644 --- a/net/wireless/trace.h +++ b/net/wireless/trace.h @@ -68,7 +68,8 @@ __field(u16, ht_opmode) \ __field(u32, dot11MeshHWMPactivePathToRootTimeout) \ __field(u16, dot11MeshHWMProotInterval) \ - __field(u16, dot11MeshHWMPconfirmationInterval) + __field(u16, dot11MeshHWMPconfirmationInterval) \ + __field(bool, dot11MeshNolearn) #define MESH_CFG_ASSIGN \ do { \ __entry->dot11MeshRetryTimeout = conf->dot11MeshRetryTimeout; \ @@ -109,6 +110,7 @@ conf->dot11MeshHWMProotInterval; \ __entry->dot11MeshHWMPconfirmationInterval = \ conf->dot11MeshHWMPconfirmationInterval; \ + __entry->dot11MeshNolearn = conf->dot11MeshNolearn; \ } while (0) #define CHAN_ENTRY __field(enum nl80211_band, band) \ -- cgit v1.2.3