Return-path: Received: from mail-pd0-f202.google.com ([209.85.192.202]:46909 "EHLO mail-pd0-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750728AbaBZAiu (ORCPT ); Tue, 25 Feb 2014 19:38:50 -0500 Received: by mail-pd0-f202.google.com with SMTP id v10so33191pde.5 for ; Tue, 25 Feb 2014 16:38:50 -0800 (PST) Received: from corp2gmr1-1.hot.corp.google.com (corp2gmr1-1.hot.corp.google.com [172.24.189.92]) by gmr-mx.google.com with ESMTPS id x29si746557yha.0.2014.02.25.16.32.55 for (version=TLSv1.1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 25 Feb 2014 16:32:55 -0800 (PST) Received: from clearcreek.mtv.corp.google.com (clearcreek.mtv.corp.google.com [172.22.73.104]) by corp2gmr1-1.hot.corp.google.com (Postfix) with ESMTP id D294F31C3BF for ; Tue, 25 Feb 2014 16:32:54 -0800 (PST) From: Paul Stewart Date: Tue, 25 Feb 2014 16:31:37 -0800 Subject: [PATCH] mwifiex: Track BA sequence number reset To: linux-wireless@vger.kernel.org Message-Id: <20140226003254.6ADE9200505@clearcreek.mtv.corp.google.com> (sfid-20140226_013854_463441_32A467AD) Sender: linux-wireless-owner@vger.kernel.org List-ID: Some stations reset the sequence number for traffic-ids (TIDs) as they initiate a block-ACK session. In order to detect such behavior, mwifiex must note the starting sequence number given during the ADDBA request. If the first received sequence number after the ADDBA falls outside the receive window for this TID but after the the ADDBA starting sequence number, we can assume that this AP has reset its sequence number during the ADDBA. In this case we must adjust the input window backward to incorporate this received sequence number instead of ignoring it. Otherwise, we could fail to successfully retrieve an arbitrarily large number of downstream frames at the beginning of the block-ACK session. Signed-off-by: Paul Stewart --- drivers/net/wireless/mwifiex/11n_rxreorder.c | 27 +++++++++++++++++++++------ drivers/net/wireless/mwifiex/11n_rxreorder.h | 3 ++- drivers/net/wireless/mwifiex/main.h | 1 + 3 files changed, 24 insertions(+), 7 deletions(-) diff --git a/drivers/net/wireless/mwifiex/11n_rxreorder.c b/drivers/net/wireless/mwifiex/11n_rxreorder.c index eb17282..35329cf 100644 --- a/drivers/net/wireless/mwifiex/11n_rxreorder.c +++ b/drivers/net/wireless/mwifiex/11n_rxreorder.c @@ -279,6 +279,8 @@ mwifiex_11n_create_rx_reorder_tbl(struct mwifiex_private *priv, u8 *ta, new_node->tid = tid; memcpy(new_node->ta, ta, ETH_ALEN); new_node->start_win = seq_num; + new_node->init_win = seq_num; + new_node->flags = 0; if (mwifiex_queuing_ra_based(priv)) { dev_dbg(priv->adapter->dev, @@ -298,11 +300,12 @@ mwifiex_11n_create_rx_reorder_tbl(struct mwifiex_private *priv, u8 *ta, } if (last_seq != MWIFIEX_DEF_11N_RX_SEQ_NUM && - last_seq >= new_node->start_win) + last_seq >= new_node->start_win) { new_node->start_win = last_seq + 1; + new_node->flags |= RXREOR_INIT_WINDOW_SHIFT; + } new_node->win_size = win_size; - new_node->flags = 0; new_node->rx_reorder_ptr = kzalloc(sizeof(void *) * win_size, GFP_KERNEL); @@ -452,6 +455,7 @@ int mwifiex_11n_rx_reorder_pkt(struct mwifiex_private *priv, struct mwifiex_rx_reorder_tbl *tbl; int start_win, end_win, win_size; u16 pkt_index; + bool init_window_shift = false; tbl = mwifiex_11n_get_rx_reorder_tbl(priv, tid, ta); if (!tbl) { @@ -466,18 +470,29 @@ int mwifiex_11n_rx_reorder_pkt(struct mwifiex_private *priv, start_win = tbl->start_win; win_size = tbl->win_size; end_win = ((start_win + win_size) - 1) & (MAX_TID_VALUE - 1); + if (tbl->flags & RXREOR_INIT_WINDOW_SHIFT) { + init_window_shift = true; + tbl->flags &= ~RXREOR_INIT_WINDOW_SHIFT; + } mod_timer(&tbl->timer_context.timer, jiffies + msecs_to_jiffies(MIN_FLUSH_TIMER_MS * win_size)); - /* - * If seq_num is less then starting win then ignore and drop the - * packet - */ if (tbl->flags & RXREOR_FORCE_NO_DROP) { dev_dbg(priv->adapter->dev, "RXREOR_FORCE_NO_DROP when HS is activated\n"); tbl->flags &= ~RXREOR_FORCE_NO_DROP; + } else if (init_window_shift && seq_num < start_win && + seq_num >= tbl->init_win) { + dev_dbg(priv->adapter->dev, + "Sender TID sequence number reset %d->%d for SSN %d\n", + start_win, seq_num, tbl->init_win); + tbl->start_win = start_win = seq_num; + end_win = ((start_win + win_size) - 1) & (MAX_TID_VALUE - 1); } else { + /* + * If seq_num is less then starting win then ignore and drop + * the packet + */ if ((start_win + TWOPOW11) > (MAX_TID_VALUE - 1)) { if (seq_num >= ((start_win + TWOPOW11) & (MAX_TID_VALUE - 1)) && diff --git a/drivers/net/wireless/mwifiex/11n_rxreorder.h b/drivers/net/wireless/mwifiex/11n_rxreorder.h index 4064041..0fc76e4 100644 --- a/drivers/net/wireless/mwifiex/11n_rxreorder.h +++ b/drivers/net/wireless/mwifiex/11n_rxreorder.h @@ -42,7 +42,8 @@ #define BA_SETUP_PACKET_OFFSET 16 enum mwifiex_rxreor_flags { - RXREOR_FORCE_NO_DROP = 1<<0, + RXREOR_FORCE_NO_DROP = 1<<0, + RXREOR_INIT_WINDOW_SHIFT = 1<<1, }; static inline void mwifiex_reset_11n_rx_seq_num(struct mwifiex_private *priv) diff --git a/drivers/net/wireless/mwifiex/main.h b/drivers/net/wireless/mwifiex/main.h index 407f8ea..cb1148f 100644 --- a/drivers/net/wireless/mwifiex/main.h +++ b/drivers/net/wireless/mwifiex/main.h @@ -575,6 +575,7 @@ struct mwifiex_rx_reorder_tbl { struct list_head list; int tid; u8 ta[ETH_ALEN]; + int init_win; int start_win; int win_size; void **rx_reorder_ptr; -- 1.9.0.rc1.175.g0b1dcb5