Return-path: Received: from mail-pa0-f52.google.com ([209.85.220.52]:53657 "EHLO mail-pa0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755295Ab3IMXg0 (ORCPT ); Fri, 13 Sep 2013 19:36:26 -0400 Received: by mail-pa0-f52.google.com with SMTP id kq13so3102460pab.25 for ; Fri, 13 Sep 2013 16:36:26 -0700 (PDT) From: Chun-Yeow Yeoh To: linux-wireless@vger.kernel.org Cc: johannes@sipsolutions.net, linville@tuxdriver.com, devel@lists.open80211s.org, distro11s@cozybit.com, Chun-Yeow Yeoh Subject: [PATCH 1/5] mac80211: process the CSA frame for mesh accordingly Date: Fri, 13 Sep 2013 16:36:08 -0700 Message-Id: <1379115372-28426-2-git-send-email-yeohchunyeow@cozybit.com> (sfid-20130914_013630_343369_2388EFD1) In-Reply-To: <1379115372-28426-1-git-send-email-yeohchunyeow@cozybit.com> References: <1379115372-28426-1-git-send-email-yeohchunyeow@cozybit.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: Process the CSA frame according to the procedures define in IEEE Std 802.11-2012 section 10.9.8.4.3 as follow: * The mesh channel switch parameters element (MCSP) must be availabe. * If the MCSP's TTL is 1, drop the frame but still process the CSA. * If the MCSP's precedence value is less than or equal to the current precedence value, drop the frame and do not process the CSA. * The CSA frame is forwarded after TTL is decremented by 1 and the initiator field is set to 0. Transmit restrict field and others are maintained as is. * No beacon or probe response frame are handled here. Also, introduce the debug message used for mesh CSA purpose. Signed-off-by: Chun-Yeow Yeoh --- include/linux/ieee80211.h | 20 +++++++++++ net/mac80211/Kconfig | 11 ++++++ net/mac80211/debug.h | 10 ++++++ net/mac80211/ieee80211_i.h | 4 +++ net/mac80211/mesh.c | 83 ++++++++++++++++++++++++++++++++++++++++++-- net/mac80211/util.c | 9 +++++ 6 files changed, 134 insertions(+), 3 deletions(-) diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h index 23a8877..f117427 100644 --- a/include/linux/ieee80211.h +++ b/include/linux/ieee80211.h @@ -696,6 +696,18 @@ struct ieee80211_sec_chan_offs_ie { } __packed; /** + * struct ieee80211_mesh_chansw_params_ie - mesh channel switch parameters IE + * + * This structure represents the "Mesh Channel Switch Paramters element" + */ +struct ieee80211_mesh_chansw_params_ie { + u8 mesh_ttl; + u8 mesh_flags; + __le16 mesh_reason; + __le16 mesh_pre_value; +} __packed; + +/** * struct ieee80211_wide_bw_chansw_ie - wide bandwidth channel switch IE */ struct ieee80211_wide_bw_chansw_ie { @@ -750,6 +762,14 @@ enum mesh_config_capab_flags { }; /** + * mesh channel switch parameters element's flag indicator + * + */ +#define WLAN_EID_CHAN_SWITCH_PARAM_TX_RESTRICT BIT(0) +#define WLAN_EID_CHAN_SWITCH_PARAM_INITIATOR BIT(1) +#define WLAN_EID_CHAN_SWITCH_PARAM_REASON BIT(2) + +/** * struct ieee80211_rann_ie * * This structure refers to "Root Announcement information element" diff --git a/net/mac80211/Kconfig b/net/mac80211/Kconfig index 62535fe..bf1871e 100644 --- a/net/mac80211/Kconfig +++ b/net/mac80211/Kconfig @@ -258,6 +258,17 @@ config MAC80211_MESH_SYNC_DEBUG Do not select this option. +config MAC80211_MESH_CSA_DEBUG + bool "Verbose mesh channel switch debugging" + depends on MAC80211_DEBUG_MENU + depends on MAC80211_MESH + ---help--- + Selecting this option causes mac80211 to print out very verbose mesh + channel switch debugging messages (when mac80211 is taking part in a + mesh network). + + Do not select this option. + config MAC80211_MESH_PS_DEBUG bool "Verbose mesh powersave debugging" depends on MAC80211_DEBUG_MENU diff --git a/net/mac80211/debug.h b/net/mac80211/debug.h index 4ccc5ed..493d680 100644 --- a/net/mac80211/debug.h +++ b/net/mac80211/debug.h @@ -44,6 +44,12 @@ #define MAC80211_MESH_SYNC_DEBUG 0 #endif +#ifdef CONFIG_MAC80211_MESH_CSA_DEBUG +#define MAC80211_MESH_CSA_DEBUG 1 +#else +#define MAC80211_MESH_CSA_DEBUG 0 +#endif + #ifdef CONFIG_MAC80211_MESH_PS_DEBUG #define MAC80211_MESH_PS_DEBUG 1 #else @@ -157,6 +163,10 @@ do { \ _sdata_dbg(MAC80211_MESH_SYNC_DEBUG, \ sdata, fmt, ##__VA_ARGS__) +#define mcsa_dbg(sdata, fmt, ...) \ + _sdata_dbg(MAC80211_MESH_CSA_DEBUG, \ + sdata, fmt, ##__VA_ARGS__) + #define mps_dbg(sdata, fmt, ...) \ _sdata_dbg(MAC80211_MESH_PS_DEBUG, \ sdata, fmt, ##__VA_ARGS__) diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 3a87c89..7f13b65 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -598,6 +598,9 @@ struct ieee80211_if_mesh { int ps_peers_light_sleep; int ps_peers_deep_sleep; struct ps_data ps; + /* Channel Switching Support */ + bool chsw_init; + u16 pre_value; }; #ifdef CONFIG_MAC80211_MESH @@ -1239,6 +1242,7 @@ struct ieee802_11_elems { const struct ieee80211_timeout_interval_ie *timeout_int; const u8 *opmode_notif; const struct ieee80211_sec_chan_offs_ie *sec_chan_offs; + const struct ieee80211_mesh_chansw_params_ie *mesh_chansw_params_ie; /* length of them, respectively */ u8 ssid_len; diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c index 707ac61..308ef98 100644 --- a/net/mac80211/mesh.c +++ b/net/mac80211/mesh.c @@ -920,6 +920,82 @@ static void ieee80211_mesh_rx_bcn_presp(struct ieee80211_sub_if_data *sdata, stype, mgmt, &elems, rx_status); } +static int mesh_fwd_csa_frame(struct ieee80211_sub_if_data *sdata, + struct ieee80211_mgmt *mgmt, size_t len) +{ + 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) + return -1; + skb_reserve(skb, local->tx_headroom); + mgmt_fwd = (struct ieee80211_mgmt *) skb_put(skb, len); + + /* offset_ttl is based on whether the secondary channel + * offset is available or not. Substract 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; + + memcpy(mgmt_fwd, mgmt, len); + eth_broadcast_addr(mgmt_fwd->da); + memcpy(mgmt_fwd->sa, sdata->vif.addr, ETH_ALEN); + memcpy(mgmt_fwd->bssid, sdata->vif.addr, ETH_ALEN); + + ieee80211_tx_skb(sdata, skb); + return 0; +} + +static void mesh_rx_csa_frame(struct ieee80211_sub_if_data *sdata, + struct ieee80211_mgmt *mgmt, size_t len) +{ + struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; + struct ieee802_11_elems elems; + u16 pre_value; + bool block_tx, fwd_csa = true; + size_t baselen; + u8 *pos, ttl; + + if (mgmt->u.action.u.measurement.action_code != + WLAN_ACTION_SPCT_CHL_SWITCH) + return; + + pos = mgmt->u.action.u.chan_switch.variable; + baselen = offsetof(struct ieee80211_mgmt, + u.action.u.chan_switch.variable); + ieee802_11_parse_elems(pos, len - baselen, false, &elems); + + ttl = elems.mesh_chansw_params_ie->mesh_ttl; + if (!--ttl) + fwd_csa = false; + + pre_value = le16_to_cpu(elems.mesh_chansw_params_ie->mesh_pre_value); + if (ifmsh->pre_value >= pre_value) + return; + + ifmsh->pre_value = pre_value; + + /* forward or re-broadcast the CSA frame */ + if (fwd_csa) { + if (mesh_fwd_csa_frame(sdata, mgmt, len) < 0) + mcsa_dbg(sdata, "Failed to forward the CSA frame"); + } + + /* block the Tx only after fowarding the CSA frame if required */ + block_tx = !!(elems.mesh_chansw_params_ie->mesh_flags + & WLAN_EID_CHAN_SWITCH_PARAM_TX_RESTRICT); + if (block_tx) + ieee80211_stop_queues_by_reason(&sdata->local->hw, + IEEE80211_MAX_QUEUE_MAP, + IEEE80211_QUEUE_STOP_REASON_CSA); +} + static void ieee80211_mesh_rx_mgmt_action(struct ieee80211_sub_if_data *sdata, struct ieee80211_mgmt *mgmt, size_t len, @@ -939,6 +1015,9 @@ static void ieee80211_mesh_rx_mgmt_action(struct ieee80211_sub_if_data *sdata, if (mesh_action_is_path_sel(mgmt)) mesh_rx_path_sel_frame(sdata, mgmt, len); break; + case WLAN_CATEGORY_SPECTRUM_MGMT: + mesh_rx_csa_frame(sdata, mgmt, len); + break; } } @@ -1056,13 +1135,11 @@ void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata) (unsigned long) sdata); ifmsh->accepting_plinks = true; - ifmsh->preq_id = 0; - ifmsh->sn = 0; - ifmsh->num_gates = 0; atomic_set(&ifmsh->mpaths, 0); mesh_rmc_init(sdata); ifmsh->last_preq = jiffies; ifmsh->next_perr = jiffies; + ifmsh->chsw_init = false; /* Allocate all mesh structures when creating the first mesh interface. */ if (!mesh_allocated) ieee80211s_init(); diff --git a/net/mac80211/util.c b/net/mac80211/util.c index 3c8283b..133667c 100644 --- a/net/mac80211/util.c +++ b/net/mac80211/util.c @@ -743,6 +743,7 @@ u32 ieee802_11_parse_elems_crc(const u8 *start, size_t len, bool action, case WLAN_EID_TIMEOUT_INTERVAL: case WLAN_EID_SECONDARY_CHANNEL_OFFSET: case WLAN_EID_WIDE_BW_CHANNEL_SWITCH: + case WLAN_EID_CHAN_SWITCH_PARAM: /* * not listing WLAN_EID_CHANNEL_SWITCH_WRAPPER -- it seems possible * that if the content gets bigger it might be needed more than once @@ -908,6 +909,14 @@ u32 ieee802_11_parse_elems_crc(const u8 *start, size_t len, bool action, } elems->sec_chan_offs = (void *)pos; break; + case WLAN_EID_CHAN_SWITCH_PARAM: + if (elen != + sizeof(*elems->mesh_chansw_params_ie)) { + elem_parse_failed = true; + break; + } + elems->mesh_chansw_params_ie = (void *)pos; + break; case WLAN_EID_WIDE_BW_CHANNEL_SWITCH: if (!action || elen != sizeof(*elems->wide_bw_chansw_ie)) { -- 1.7.9.5