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author | Linus Lüssing <ll@simonwunderlich.de> | 2020-06-17 09:30:33 +0200 |
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committer | Johannes Berg <johannes.berg@intel.com> | 2020-07-31 09:24:23 +0200 |
commit | e3718a611470d311a92c60d4eb535270b49a7108 (patch) | |
tree | 3e5daf705d3dfd6cc2a128623e0e4dbc897d8aac /net/mac80211 | |
parent | 2f1805ea209a146669e0b660633ed22f49e1dd49 (diff) | |
download | linux-e3718a611470d311a92c60d4eb535270b49a7108.tar.gz linux-e3718a611470d311a92c60d4eb535270b49a7108.tar.bz2 linux-e3718a611470d311a92c60d4eb535270b49a7108.zip |
cfg80211/mac80211: add mesh_param "mesh_nolearn" to skip path discovery
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 <sven@narfation.org>
Cc: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Linus Lüssing <ll@simonwunderlich.de>
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 <johannes.berg@intel.com>
Diffstat (limited to 'net/mac80211')
-rw-r--r-- | net/mac80211/cfg.c | 2 | ||||
-rw-r--r-- | net/mac80211/debugfs_netdev.c | 2 | ||||
-rw-r--r-- | net/mac80211/mesh_hwmp.c | 39 |
3 files changed, 43 insertions, 0 deletions
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c index b4a74064675e..9af56b848544 100644 --- a/net/mac80211/cfg.c +++ b/net/mac80211/cfg.c @@ -2126,6 +2126,8 @@ static int ieee80211_update_mesh_config(struct wiphy *wiphy, if (_chg_mesh_attr(NL80211_MESHCONF_CONNECTED_TO_GATE, mask)) conf->dot11MeshConnectedToMeshGate = nconf->dot11MeshConnectedToMeshGate; + if (_chg_mesh_attr(NL80211_MESHCONF_NOLEARN, mask)) + conf->dot11MeshNolearn = nconf->dot11MeshNolearn; ieee80211_mbss_info_change_notify(sdata, BSS_CHANGED_BEACON); return 0; } diff --git a/net/mac80211/debugfs_netdev.c b/net/mac80211/debugfs_netdev.c index d7e955127d5c..09eab2c3f380 100644 --- a/net/mac80211/debugfs_netdev.c +++ b/net/mac80211/debugfs_netdev.c @@ -638,6 +638,7 @@ IEEE80211_IF_FILE(dot11MeshAwakeWindowDuration, u.mesh.mshcfg.dot11MeshAwakeWindowDuration, DEC); IEEE80211_IF_FILE(dot11MeshConnectedToMeshGate, u.mesh.mshcfg.dot11MeshConnectedToMeshGate, DEC); +IEEE80211_IF_FILE(dot11MeshNolearn, u.mesh.mshcfg.dot11MeshNolearn, DEC); #endif #define DEBUGFS_ADD_MODE(name, mode) \ @@ -762,6 +763,7 @@ static void add_mesh_config(struct ieee80211_sub_if_data *sdata) MESHPARAMS_ADD(power_mode); MESHPARAMS_ADD(dot11MeshAwakeWindowDuration); MESHPARAMS_ADD(dot11MeshConnectedToMeshGate); + MESHPARAMS_ADD(dot11MeshNolearn); #undef MESHPARAMS_ADD } #endif diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c index bae3a3e15b88..bec23d2eee7a 100644 --- a/net/mac80211/mesh_hwmp.c +++ b/net/mac80211/mesh_hwmp.c @@ -1173,6 +1173,40 @@ int mesh_nexthop_resolve(struct ieee80211_sub_if_data *sdata, } /** + * mesh_nexthop_lookup_nolearn - try to set next hop without path discovery + * @skb: 802.11 frame to be sent + * @sdata: network subif the frame will be sent through + * + * Check if the meshDA (addr3) of a unicast frame is a direct neighbor. + * And if so, set the RA (addr1) to it to transmit to this node directly, + * avoiding PREQ/PREP path discovery. + * + * Returns: 0 if the next hop was found and -ENOENT otherwise. + */ +static int mesh_nexthop_lookup_nolearn(struct ieee80211_sub_if_data *sdata, + struct sk_buff *skb) +{ + struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; + struct sta_info *sta; + + if (is_multicast_ether_addr(hdr->addr1)) + return -ENOENT; + + rcu_read_lock(); + sta = sta_info_get(sdata, hdr->addr3); + + if (!sta || sta->mesh->plink_state != NL80211_PLINK_ESTAB) { + rcu_read_unlock(); + return -ENOENT; + } + rcu_read_unlock(); + + memcpy(hdr->addr1, hdr->addr3, ETH_ALEN); + memcpy(hdr->addr2, sdata->vif.addr, ETH_ALEN); + return 0; +} + +/** * mesh_nexthop_lookup - put the appropriate next hop on a mesh frame. Calling * this function is considered "using" the associated mpath, so preempt a path * refresh if this mpath expires soon. @@ -1185,11 +1219,16 @@ int mesh_nexthop_resolve(struct ieee80211_sub_if_data *sdata, int mesh_nexthop_lookup(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb) { + struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; struct mesh_path *mpath; struct sta_info *next_hop; struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data; u8 *target_addr = hdr->addr3; + if (ifmsh->mshcfg.dot11MeshNolearn && + !mesh_nexthop_lookup_nolearn(sdata, skb)) + return 0; + mpath = mesh_path_lookup(sdata, target_addr); if (!mpath || !(mpath->flags & MESH_PATH_ACTIVE)) return -ENOENT; |