Return-path: Received: from mail-pb0-f46.google.com ([209.85.160.46]:65066 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753830Ab2CWCM4 (ORCPT ); Thu, 22 Mar 2012 22:12:56 -0400 Received: by pbcun15 with SMTP id un15so2087868pbc.19 for ; Thu, 22 Mar 2012 19:12:55 -0700 (PDT) From: Chun-Yeow Yeoh To: linux-wireless@vger.kernel.org Cc: johannes@sipsolutions.net, javier@cozybit.com, thomas@cozybit.com, linville@tuxdriver.com, devel@lists.open80211s.org, lindner_marek@yahoo.de, Chun-Yeow Yeoh Subject: [PATCH v3] mac80211: fix the RANN propagation issues Date: Fri, 23 Mar 2012 18:48:51 +0800 Message-Id: <1332499731-28311-1-git-send-email-yeohchunyeow@gmail.com> (sfid-20120323_031310_782473_A8F80D96) Sender: linux-wireless-owner@vger.kernel.org List-ID: This patch is intended to solve the follwing issues in RANN propagation: [1] The interval in propagated RANN should be based on the interval of received RANN. [2] The aggregated path metric for propagated RANN is as received plus own link metric towards the transmitting mesh STA (not root mesh STA). [3] The comparison of path metric for RANN with same sequence number should be done before deciding whether to propagate or not. Signed-off-by: Chun-Yeow Yeoh --- v2: revert back to plain conditionals (Javier and Thomas) v3: SN comparison in modulo 2^32 (Javier and Marek) net/mac80211/mesh.h | 2 ++ net/mac80211/mesh_hwmp.c | 24 ++++++++++++++++++------ 2 files changed, 20 insertions(+), 6 deletions(-) diff --git a/net/mac80211/mesh.h b/net/mac80211/mesh.h index 8d53b71..adf1be3 100644 --- a/net/mac80211/mesh.h +++ b/net/mac80211/mesh.h @@ -86,6 +86,7 @@ enum mesh_deferred_task_flags { * mpath itself. No need to take this lock when adding or removing * an mpath to a hash bucket on a path table. * @rann_snd_addr: the RANN sender address + * @rann_metric: the aggregated path metric towards the root node * @is_root: the destination station of this path is a root node * @is_gate: the destination station of this path is a mesh gate * @@ -112,6 +113,7 @@ struct mesh_path { enum mesh_path_flags flags; spinlock_t state_lock; u8 rann_snd_addr[ETH_ALEN]; + u32 rann_metric; bool is_root; bool is_gate; }; diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c index f80a9e3..a80da37 100644 --- a/net/mac80211/mesh_hwmp.c +++ b/net/mac80211/mesh_hwmp.c @@ -86,8 +86,8 @@ static inline u32 u16_field_get(u8 *preq_elem, int offset, bool ae) #define PERR_IE_TARGET_RCODE(x) u16_field_get(x, 13, 0) #define MSEC_TO_TU(x) (x*1000/1024) -#define SN_GT(x, y) ((long) (y) - (long) (x) < 0) -#define SN_LT(x, y) ((long) (x) - (long) (y) < 0) +#define SN_GT(x, y) ((s32)(y - x) < 0) +#define SN_LT(x, y) ((s32)(x - y) < 0) #define net_traversal_jiffies(s) \ msecs_to_jiffies(s->u.mesh.mshcfg.dot11MeshHWMPnetDiameterTraversalTime) @@ -732,11 +732,12 @@ static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata, struct ieee80211_rann_ie *rann) { struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; + struct ieee80211_local *local = sdata->local; + struct sta_info *sta; struct mesh_path *mpath; u8 ttl, flags, hopcount; u8 *orig_addr; - u32 orig_sn, metric; - u32 interval = ifmsh->mshcfg.dot11MeshHWMPRannInterval; + u32 orig_sn, metric, metric_txsta, interval; bool root_is_gate; ttl = rann->rann_ttl; @@ -749,6 +750,7 @@ static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata, root_is_gate = !!(flags & RANN_FLAG_IS_GATE); orig_addr = rann->rann_addr; orig_sn = le32_to_cpu(rann->rann_seq); + interval = le32_to_cpu(rann->rann_interval); hopcount = rann->rann_hopcount; hopcount++; metric = le32_to_cpu(rann->rann_metric); @@ -761,6 +763,14 @@ static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata, orig_addr, mgmt->sa, root_is_gate); rcu_read_lock(); + sta = sta_info_get(sdata, mgmt->sa); + if (!sta) { + rcu_read_unlock(); + return; + } + + metric_txsta = airtime_link_metric_get(local, sta); + mpath = mesh_path_lookup(orig_addr, sdata); if (!mpath) { mesh_path_add(orig_addr, sdata); @@ -780,14 +790,16 @@ static void hwmp_rann_frame_process(struct ieee80211_sub_if_data *sdata, mesh_queue_preq(mpath, PREQ_Q_F_START | PREQ_Q_F_REFRESH); } - if (mpath->sn < orig_sn && ifmsh->mshcfg.dot11MeshForwarding) { + if ((SN_LT(mpath->sn, orig_sn) || (mpath->sn == orig_sn && + metric < mpath->rann_metric)) && 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 + mpath->metric), + cpu_to_le32(metric + metric_txsta), 0, sdata); mpath->sn = orig_sn; + mpath->rann_metric = metric + metric_txsta; } /* Using individually addressed PREQ for root node */ -- 1.7.0.4