Return-path: Received: from mail-he1eur01on0084.outbound.protection.outlook.com ([104.47.0.84]:49365 "EHLO EUR01-HE1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751109AbeAYBQ1 (ORCPT ); Wed, 24 Jan 2018 20:16:27 -0500 From: peter.oh@bowerswilkins.com To: linux-wireless@vger.kernel.org, johannes@sipsolutions.net Cc: Peter Oh , johannes.berg@intel.com Subject: [PATCH v3] mac80211: mesh: fix wrong mesh TTL offset calculation Date: Wed, 24 Jan 2018 17:16:10 -0800 Message-Id: <8582518b7f032acfa598faf7d26c765b09149e90.1516842930.git.peter.oh@bowerswilkins.com> (sfid-20180125_021632_489749_72A7408C) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-wireless-owner@vger.kernel.org List-ID: From: Peter Oh mesh TTL offset in Mesh Channel Switch Parameters element depends on not only Secondary Channel Offset element, but also affected by HT Control field and Wide Bandwidth Channel Switch element. Use element structure to correct the miscalculation. Signed-off-by: Peter Oh --- net/mac80211/mesh.c | 17 ++++++----------- 1 file changed, 6 insertions(+), 11 deletions(-) diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c index 73ac607..6a381cb 100644 --- a/net/mac80211/mesh.c +++ b/net/mac80211/mesh.c @@ -1255,13 +1255,12 @@ int ieee80211_mesh_csa_beacon(struct ieee80211_sub_if_data *sdata, } static int mesh_fwd_csa_frame(struct ieee80211_sub_if_data *sdata, - struct ieee80211_mgmt *mgmt, size_t len) + struct ieee80211_mgmt *mgmt, size_t len, + struct ieee802_11_elems *elems) { struct ieee80211_mgmt *mgmt_fwd; struct sk_buff *skb; struct ieee80211_local *local = sdata->local; - u8 *pos = mgmt->u.action.u.chan_switch.variable; - size_t offset_ttl; skb = dev_alloc_skb(local->tx_headroom + len); if (!skb) @@ -1269,13 +1268,9 @@ static int mesh_fwd_csa_frame(struct ieee80211_sub_if_data *sdata, skb_reserve(skb, local->tx_headroom); mgmt_fwd = skb_put(skb, len); - /* offset_ttl is based on whether the secondary channel - * offset is available or not. Subtract 1 from the mesh TTL - * and disable the initiator flag before forwarding. - */ - offset_ttl = (len < 42) ? 7 : 10; - *(pos + offset_ttl) -= 1; - *(pos + offset_ttl + 1) &= ~WLAN_EID_CHAN_SWITCH_PARAM_INITIATOR; + elems->mesh_chansw_params_ie->mesh_ttl--; + elems->mesh_chansw_params_ie->mesh_flags &= + ~WLAN_EID_CHAN_SWITCH_PARAM_INITIATOR; memcpy(mgmt_fwd, mgmt, len); eth_broadcast_addr(mgmt_fwd->da); @@ -1323,7 +1318,7 @@ static void mesh_rx_csa_frame(struct ieee80211_sub_if_data *sdata, /* forward or re-broadcast the CSA frame */ if (fwd_csa) { - if (mesh_fwd_csa_frame(sdata, mgmt, len) < 0) + if (mesh_fwd_csa_frame(sdata, mgmt, len, &elems) < 0) mcsa_dbg(sdata, "Failed to forward the CSA frame"); } } -- 2.7.4