Return-path: Received: from mail-wg0-f49.google.com ([74.125.82.49]:40958 "EHLO mail-wg0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751449AbaKIQu2 (ORCPT ); Sun, 9 Nov 2014 11:50:28 -0500 Received: by mail-wg0-f49.google.com with SMTP id x13so7060940wgg.22 for ; Sun, 09 Nov 2014 08:50:26 -0800 (PST) From: Arik Nemtsov To: Cc: Johannes Berg , Liad Kaufman , Arik Nemtsov Subject: [PATCH 02/16] mac80211: retransmit TDLS teardown packet through AP if not ACKed Date: Sun, 9 Nov 2014 18:50:08 +0200 Message-Id: <1415551822-20121-2-git-send-email-arik@wizery.com> (sfid-20141109_175038_852518_4DF1B9DC) In-Reply-To: <1415551822-20121-1-git-send-email-arik@wizery.com> References: <1415551822-20121-1-git-send-email-arik@wizery.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: From: Liad Kaufman Since the TDLS peer station might not receive the teardown packet (e.g., when in PS), this makes sure the packet is retransmitted - this time through the AP - if the TDLS peer didn't ACK the packet. Signed-off-by: Liad Kaufman Reviewed-by: Johannes Berg Signed-off-by: Arik Nemtsov --- include/linux/ieee80211.h | 25 ++++++++++++++++++++ net/mac80211/ieee80211_i.h | 4 ++++ net/mac80211/mlme.c | 12 ++++++++++ net/mac80211/status.c | 55 ++++++++++++++++++++++++++++++++++++++++-- net/mac80211/tdls.c | 59 +++++++++++++++++++++++++++++++++++++--------- 5 files changed, 142 insertions(+), 13 deletions(-) diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h index f65b544..4e2bb91 100644 --- a/include/linux/ieee80211.h +++ b/include/linux/ieee80211.h @@ -19,6 +19,7 @@ #include #include #include +#include /* * DS bit usage @@ -2418,6 +2419,30 @@ static inline bool ieee80211_check_tim(const struct ieee80211_tim_ie *tim, return !!(tim->virtual_map[index] & mask); } +/** + * ieee80211_get_tdls_action - get tdls packet action (or -1, if not tdls packet) + * @skb: the skb containing the frame, length will not be checked + * @hdr_size: the size of the ieee80211_hdr that starts at skb->data + * + * This function assumes the frame is a data frame, and that the network header + * is in the correct place. + */ +static inline int ieee80211_get_tdls_action(struct sk_buff *skb, u32 hdr_size) +{ + if (!skb_is_nonlinear(skb) && + skb->len > (skb_network_offset(skb) + 2)) { + /* Point to where the indication of TDLS should start */ + const u8 *tdls_data = skb_network_header(skb) - 2; + + if (get_unaligned_be16(tdls_data) == ETH_P_TDLS && + tdls_data[2] == WLAN_TDLS_SNAP_RFTYPE && + tdls_data[3] == WLAN_CATEGORY_TDLS) + return tdls_data[4]; + } + + return -1; +} + /* convert time units */ #define TU_TO_JIFFIES(x) (usecs_to_jiffies((x) * 1024)) #define TU_TO_EXP_TIME(x) (jiffies + TU_TO_JIFFIES(x)) diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 208953d..bc6f12f 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -525,8 +525,12 @@ struct ieee80211_if_managed { struct ieee80211_vht_cap vht_capa; /* configured VHT overrides */ struct ieee80211_vht_cap vht_capa_mask; /* Valid parts of vht_capa */ + /* TDLS support */ u8 tdls_peer[ETH_ALEN] __aligned(2); struct delayed_work tdls_peer_del_work; + struct sk_buff *orig_teardown_skb; /* The original teardown skb */ + struct sk_buff *teardown_skb; /* A copy to send through the AP */ + spinlock_t teardown_lock; /* To lock changing teardown_skb */ /* WMM-AC TSPEC support */ struct ieee80211_sta_tx_tspec tx_tspec[IEEE80211_NUM_ACS]; diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index 213a420..dc7f088 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -3998,6 +3998,11 @@ void ieee80211_sta_setup_sdata(struct ieee80211_sub_if_data *sdata) ifmgd->req_smps = IEEE80211_SMPS_AUTOMATIC; else ifmgd->req_smps = IEEE80211_SMPS_OFF; + + /* Setup TDLS data */ + spin_lock_init(&ifmgd->teardown_lock); + ifmgd->teardown_skb = NULL; + ifmgd->orig_teardown_skb = NULL; } /* scan finished notification */ @@ -4860,6 +4865,13 @@ void ieee80211_mgd_stop(struct ieee80211_sub_if_data *sdata) } if (ifmgd->auth_data) ieee80211_destroy_auth_data(sdata, false); + spin_lock_bh(&ifmgd->teardown_lock); + if (ifmgd->teardown_skb) { + kfree_skb(ifmgd->teardown_skb); + ifmgd->teardown_skb = NULL; + ifmgd->orig_teardown_skb = NULL; + } + spin_unlock_bh(&ifmgd->teardown_lock); del_timer_sync(&ifmgd->timer); sdata_unlock(sdata); } diff --git a/net/mac80211/status.c b/net/mac80211/status.c index 9612d89..71de2d3 100644 --- a/net/mac80211/status.c +++ b/net/mac80211/status.c @@ -390,6 +390,46 @@ ieee80211_add_tx_radiotap_header(struct ieee80211_local *local, } } +/* + * Handles the tx for TDLS teardown frames. + * If the frame wasn't ACKed by the peer - it will be re-sent through the AP + */ +static void ieee80211_tdls_td_tx_handle(struct ieee80211_local *local, + struct ieee80211_sub_if_data *sdata, + struct sk_buff *skb, u32 flags) +{ + struct sk_buff *teardown_skb; + struct sk_buff *orig_teardown_skb; + bool is_teardown = false; + + /* Get the teardown data we need and free the lock */ + spin_lock(&sdata->u.mgd.teardown_lock); + teardown_skb = sdata->u.mgd.teardown_skb; + orig_teardown_skb = sdata->u.mgd.orig_teardown_skb; + if ((skb == orig_teardown_skb) && teardown_skb) { + sdata->u.mgd.teardown_skb = NULL; + sdata->u.mgd.orig_teardown_skb = NULL; + is_teardown = true; + } + spin_unlock(&sdata->u.mgd.teardown_lock); + + if (is_teardown) { + /* This mechanism relies on being able to get ACKs */ + WARN_ON(!(local->hw.flags & + IEEE80211_HW_REPORTS_TX_ACK_STATUS)); + + /* Check if peer has ACKed */ + if (flags & IEEE80211_TX_STAT_ACK) { + dev_kfree_skb_any(teardown_skb); + } else { + tdls_dbg(sdata, + "TDLS Resending teardown through AP\n"); + + ieee80211_subif_start_xmit(teardown_skb, skb->dev); + } + } +} + static void ieee80211_report_used_skb(struct ieee80211_local *local, struct sk_buff *skb, bool dropped) { @@ -426,8 +466,19 @@ static void ieee80211_report_used_skb(struct ieee80211_local *local, if (!sdata) { skb->dev = NULL; } else if (info->flags & IEEE80211_TX_INTFL_MLME_CONN_TX) { - ieee80211_mgd_conn_tx_status(sdata, hdr->frame_control, - acked); + unsigned int hdr_size = + ieee80211_hdrlen(hdr->frame_control); + + /* Check to see if packet is a TDLS teardown packet */ + if (ieee80211_is_data(hdr->frame_control) && + (ieee80211_get_tdls_action(skb, hdr_size) == + WLAN_TDLS_TEARDOWN)) + ieee80211_tdls_td_tx_handle(local, sdata, skb, + info->flags); + else + ieee80211_mgd_conn_tx_status(sdata, + hdr->frame_control, + acked); } else if (ieee80211_is_nullfunc(hdr->frame_control) || ieee80211_is_qos_nullfunc(hdr->frame_control)) { cfg80211_probe_status(sdata->dev, hdr->addr1, diff --git a/net/mac80211/tdls.c b/net/mac80211/tdls.c index b4f368e..d4fe091 100644 --- a/net/mac80211/tdls.c +++ b/net/mac80211/tdls.c @@ -512,20 +512,22 @@ ieee80211_tdls_prep_mgmt_packet(struct wiphy *wiphy, struct net_device *dev, struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev); struct ieee80211_local *local = sdata->local; struct sk_buff *skb = NULL; + u32 flags = 0; bool send_direct; struct sta_info *sta; int ret; - skb = dev_alloc_skb(local->hw.extra_tx_headroom + - max(sizeof(struct ieee80211_mgmt), - sizeof(struct ieee80211_tdls_data)) + - 50 + /* supported rates */ - 7 + /* ext capab */ - 26 + /* max(WMM-info, WMM-param) */ - 2 + max(sizeof(struct ieee80211_ht_cap), - sizeof(struct ieee80211_ht_operation)) + - extra_ies_len + - sizeof(struct ieee80211_tdls_lnkie)); + skb = netdev_alloc_skb(dev, + local->hw.extra_tx_headroom + + max(sizeof(struct ieee80211_mgmt), + sizeof(struct ieee80211_tdls_data)) + + 50 + /* supported rates */ + 7 + /* ext capab */ + 26 + /* max(WMM-info, WMM-param) */ + 2 + max(sizeof(struct ieee80211_ht_cap), + sizeof(struct ieee80211_ht_operation)) + + extra_ies_len + + sizeof(struct ieee80211_tdls_lnkie)); if (!skb) return -ENOMEM; @@ -623,9 +625,44 @@ ieee80211_tdls_prep_mgmt_packet(struct wiphy *wiphy, struct net_device *dev, break; } + /* + * Set the WLAN_TDLS_TEARDOWN flag to indicate a teardown in progress. + * Later, if no ACK is returned from peer, we will re-send the teardown + * packet through the AP. + */ + if ((action_code == WLAN_TDLS_TEARDOWN) && + (local->hw.flags & IEEE80211_HW_REPORTS_TX_ACK_STATUS)) { + struct sta_info *sta = NULL; + bool try_resend; /* Should we keep skb for possible resend */ + + /* If not sending directly to peer - no point in keeping skb */ + rcu_read_lock(); + sta = sta_info_get(sdata, peer); + try_resend = sta && test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH); + rcu_read_unlock(); + + spin_lock_bh(&sdata->u.mgd.teardown_lock); + if (try_resend && !sdata->u.mgd.teardown_skb) { + /* Mark it as requiring TX status callback */ + flags |= IEEE80211_TX_CTL_REQ_TX_STATUS | + IEEE80211_TX_INTFL_MLME_CONN_TX; + + /* + * skb is copied since mac80211 will later set + * properties that might not be the same as the AP, + * such as encryption, QoS, addresses, etc. + * + * No problem if skb_copy() fails, so no need to check. + */ + sdata->u.mgd.teardown_skb = skb_copy(skb, GFP_ATOMIC); + sdata->u.mgd.orig_teardown_skb = skb; + } + spin_unlock_bh(&sdata->u.mgd.teardown_lock); + } + /* disable bottom halves when entering the Tx path */ local_bh_disable(); - ret = ieee80211_subif_start_xmit(skb, dev); + __ieee80211_subif_start_xmit(skb, dev, flags); local_bh_enable(); return ret; -- 1.9.1