On Thursday 10 July 2008, Johannes Berg wrote:
> This patch makes mac80211 assign proper sequence numbers to
> QoS-data frames. It also removes the old sequence number code
> because we noticed that only the driver or hardware can assign
> sequence numbers to non-QoS-data and especially management
> frames in a race-free manner because beacons aren't passed
> through mac80211's TX path.
>
> This patch also adds temporary code to the rt2x00 drivers to
> not break them completely, that code will have to be reworked
> for proper sequence numbers on beacons.
>
> It also moves sequence number assignment down in the TX path
> so no sequence numbers are assigned to frames that are dropped.
>
> Signed-off-by: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
For the rt2x00 part:
I hope the software sequencing can be fixed soon, otherwise it will
come at the expense of master and adhoc mode support. But in any
case:
Acked-by: Ivo van Doorn <IvDoorn@xxxxxxxxx>
> ---
> drivers/net/wireless/b43/xmit.c | 3 -
> drivers/net/wireless/b43legacy/xmit.c | 3 -
> drivers/net/wireless/rt2x00/rt2x00.h | 2
> drivers/net/wireless/rt2x00/rt2x00mac.c | 13 +++++
> include/net/mac80211.h | 12 ++++
> net/mac80211/ieee80211_i.h | 2
> net/mac80211/iface.c | 1
> net/mac80211/sta_info.h | 1
> net/mac80211/tx.c | 79 ++++++++++++++++++++------------
> 9 files changed, 82 insertions(+), 34 deletions(-)
>
> --- everything.orig/net/mac80211/ieee80211_i.h 2008-07-10 11:14:27.000000000 +0200
> +++ everything/net/mac80211/ieee80211_i.h 2008-07-10 11:17:18.000000000 +0200
> @@ -419,8 +419,6 @@ struct ieee80211_sub_if_data {
> */
> u64 basic_rates;
>
> - u16 sequence;
> -
> /* Fragment table for host-based reassembly */
> struct ieee80211_fragment_entry fragments[IEEE80211_FRAGMENT_MAX];
> unsigned int fragment_next;
> --- everything.orig/net/mac80211/tx.c 2008-07-10 11:14:27.000000000 +0200
> +++ everything/net/mac80211/tx.c 2008-07-10 11:17:18.000000000 +0200
> @@ -38,16 +38,6 @@
>
> /* misc utils */
>
> -static inline void ieee80211_include_sequence(struct ieee80211_sub_if_data *sdata,
> - struct ieee80211_hdr *hdr)
> -{
> - /* Set the sequence number for this frame. */
> - hdr->seq_ctrl = cpu_to_le16(sdata->sequence);
> -
> - /* Increase the sequence number. */
> - sdata->sequence = (sdata->sequence + 0x10) & IEEE80211_SCTL_SEQ;
> -}
> -
> #ifdef CONFIG_MAC80211_LOWTX_FRAME_DUMP
> static void ieee80211_dump_frame(const char *ifname, const char *title,
> const struct sk_buff *skb)
> @@ -274,17 +264,6 @@ ieee80211_tx_h_check_assoc(struct ieee80
> return TX_CONTINUE;
> }
>
> -static ieee80211_tx_result debug_noinline
> -ieee80211_tx_h_sequence(struct ieee80211_tx_data *tx)
> -{
> - struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
> -
> - if (ieee80211_hdrlen(hdr->frame_control) >= 24)
> - ieee80211_include_sequence(tx->sdata, hdr);
> -
> - return TX_CONTINUE;
> -}
> -
> /* This function is called whenever the AP is about to exceed the maximum limit
> * of buffered frames for power saving STAs. This situation should not really
> * happen often during normal operation, so dropping the oldest buffered packet
> @@ -642,6 +621,49 @@ ieee80211_tx_h_misc(struct ieee80211_tx_
> }
>
> static ieee80211_tx_result debug_noinline
> +ieee80211_tx_h_sequence(struct ieee80211_tx_data *tx)
> +{
> + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
> + struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
> + u16 *seq;
> + u8 *qc;
> + int tid;
> +
> + /* only for injected frames */
> + if (unlikely(ieee80211_is_ctl(hdr->frame_control)))
> + return TX_CONTINUE;
> +
> + if (ieee80211_hdrlen(hdr->frame_control) < 24)
> + return TX_CONTINUE;
> +
> + if (!ieee80211_is_data_qos(hdr->frame_control)) {
> + info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
> + return TX_CONTINUE;
> + }
> +
> + /*
> + * This should be true for injected/management frames only, for
> + * management frames we have set the IEEE80211_TX_CTL_ASSIGN_SEQ
> + * above since they are not QoS-data frames.
> + */
> + if (!tx->sta)
> + return TX_CONTINUE;
> +
> + /* include per-STA, per-TID sequence counter */
> +
> + qc = ieee80211_get_qos_ctl(hdr);
> + tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
> + seq = &tx->sta->tid_seq[tid];
> +
> + hdr->seq_ctrl = cpu_to_le16(*seq);
> +
> + /* Increase the sequence number. */
> + *seq = (*seq + 0x10) & IEEE80211_SCTL_SEQ;
> +
> + return TX_CONTINUE;
> +}
> +
> +static ieee80211_tx_result debug_noinline
> ieee80211_tx_h_fragment(struct ieee80211_tx_data *tx)
> {
> struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
> @@ -1110,12 +1132,12 @@ static int invoke_tx_handlers(struct iee
> goto txh_done;
>
> CALL_TXH(ieee80211_tx_h_check_assoc)
> - CALL_TXH(ieee80211_tx_h_sequence)
> CALL_TXH(ieee80211_tx_h_ps_buf)
> CALL_TXH(ieee80211_tx_h_select_key)
> CALL_TXH(ieee80211_tx_h_michael_mic_add)
> CALL_TXH(ieee80211_tx_h_rate_ctrl)
> CALL_TXH(ieee80211_tx_h_misc)
> + CALL_TXH(ieee80211_tx_h_sequence)
> CALL_TXH(ieee80211_tx_h_fragment)
> /* handlers after fragment must be aware of tx info fragmentation! */
> CALL_TXH(ieee80211_tx_h_encrypt)
> @@ -1834,9 +1856,6 @@ struct sk_buff *ieee80211_beacon_get(str
> memcpy(skb_put(skb, beacon->head_len), beacon->head,
> beacon->head_len);
>
> - ieee80211_include_sequence(sdata,
> - (struct ieee80211_hdr *)skb->data);
> -
> /*
> * Not very nice, but we want to allow the driver to call
> * ieee80211_beacon_get() as a response to the set_tim()
> @@ -1926,14 +1945,18 @@ struct sk_buff *ieee80211_beacon_get(str
>
> info->control.vif = vif;
> info->tx_rate_idx = rsel.rate_idx;
> +
> + info->flags |= IEEE80211_TX_CTL_NO_ACK;
> + info->flags |= IEEE80211_TX_CTL_DO_NOT_ENCRYPT;
> + info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
> + info->flags |= IEEE80211_TX_CTL_ASSIGN_SEQ;
> if (sdata->bss_conf.use_short_preamble &&
> sband->bitrates[rsel.rate_idx].flags & IEEE80211_RATE_SHORT_PREAMBLE)
> info->flags |= IEEE80211_TX_CTL_SHORT_PREAMBLE;
> +
> info->antenna_sel_tx = local->hw.conf.antenna_sel_tx;
> - info->flags |= IEEE80211_TX_CTL_NO_ACK;
> - info->flags |= IEEE80211_TX_CTL_DO_NOT_ENCRYPT;
> info->control.retry_limit = 1;
> - info->flags |= IEEE80211_TX_CTL_CLEAR_PS_FILT;
> +
> (*num_beacons)++;
> out:
> rcu_read_unlock();
> --- everything.orig/net/mac80211/iface.c 2008-07-10 11:14:27.000000000 +0200
> +++ everything/net/mac80211/iface.c 2008-07-10 11:17:18.000000000 +0200
> @@ -162,7 +162,6 @@ int ieee80211_if_change_type(struct ieee
> /* reset some values that shouldn't be kept across type changes */
> sdata->basic_rates = 0;
> sdata->drop_unencrypted = 0;
> - sdata->sequence = 0;
>
> return 0;
> }
> --- everything.orig/include/net/mac80211.h 2008-07-10 11:14:27.000000000 +0200
> +++ everything/include/net/mac80211.h 2008-07-10 11:17:18.000000000 +0200
> @@ -239,6 +239,17 @@ struct ieee80211_bss_conf {
> * is for the whole aggregation.
> * @IEEE80211_TX_STAT_AMPDU_NO_BACK: no block ack was returned,
> * so consider using block ack request (BAR).
> + * @IEEE80211_TX_CTL_ASSIGN_SEQ: The driver has to assign a sequence
> + * number to this frame, taking care of not overwriting the fragment
> + * number and increasing the sequence number only when the
> + * IEEE80211_TX_CTL_FIRST_FRAGMENT flags is set. mac80211 will properly
> + * assign sequence numbers to QoS-data frames but cannot do so correctly
> + * for non-QoS-data and management frames because beacons need them from
> + * that counter as well and mac80211 cannot guarantee proper sequencing.
> + * If this flag is set, the driver should instruct the hardware to
> + * assign a sequence number to the frame or assign one itself. Cf. IEEE
> + * 802.11-2007 7.1.3.4.1 paragraph 3. This flag will always be set for
> + * beacons always be clear for frames without a sequence number field.
> */
> enum mac80211_tx_control_flags {
> IEEE80211_TX_CTL_REQ_TX_STATUS = BIT(0),
> @@ -265,6 +276,7 @@ enum mac80211_tx_control_flags {
> IEEE80211_TX_STAT_ACK = BIT(21),
> IEEE80211_TX_STAT_AMPDU = BIT(22),
> IEEE80211_TX_STAT_AMPDU_NO_BACK = BIT(23),
> + IEEE80211_TX_CTL_ASSIGN_SEQ = BIT(24),
> };
>
>
> --- everything.orig/drivers/net/wireless/b43/xmit.c 2008-07-10 11:14:27.000000000 +0200
> +++ everything/drivers/net/wireless/b43/xmit.c 2008-07-10 11:17:18.000000000 +0200
> @@ -317,7 +317,8 @@ int b43_generate_txhdr(struct b43_wldev
> /* MAC control */
> if (!(info->flags & IEEE80211_TX_CTL_NO_ACK))
> mac_ctl |= B43_TXH_MAC_ACK;
> - if (!ieee80211_is_pspoll(fctl))
> + /* use hardware sequence counter as the non-TID counter */
> + if (info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ)
> mac_ctl |= B43_TXH_MAC_HWSEQ;
> if (info->flags & IEEE80211_TX_CTL_FIRST_FRAGMENT)
> mac_ctl |= B43_TXH_MAC_STMSDU;
> --- everything.orig/net/mac80211/sta_info.h 2008-07-10 11:14:27.000000000 +0200
> +++ everything/net/mac80211/sta_info.h 2008-07-10 11:17:18.000000000 +0200
> @@ -285,6 +285,7 @@ struct sta_info {
> unsigned long tx_fragments;
> int txrate_idx;
> int last_txrate_idx;
> + u16 tid_seq[IEEE80211_QOS_CTL_TID_MASK + 1];
> #ifdef CONFIG_MAC80211_DEBUG_COUNTERS
> unsigned int wme_tx_queue[NUM_RX_DATA_QUEUES];
> #endif
> --- everything.orig/drivers/net/wireless/rt2x00/rt2x00.h 2008-07-10 11:14:27.000000000 +0200
> +++ everything/drivers/net/wireless/rt2x00/rt2x00.h 2008-07-10 11:17:18.000000000 +0200
> @@ -364,6 +364,8 @@ struct rt2x00_intf {
> #define DELAYED_UPDATE_BEACON 0x00000001
> #define DELAYED_CONFIG_ERP 0x00000002
> #define DELAYED_LED_ASSOC 0x00000004
> +
> + u16 seqno;
> };
>
> static inline struct rt2x00_intf* vif_to_intf(struct ieee80211_vif *vif)
> --- everything.orig/drivers/net/wireless/rt2x00/rt2x00mac.c 2008-07-10 11:14:27.000000000 +0200
> +++ everything/drivers/net/wireless/rt2x00/rt2x00mac.c 2008-07-10 11:17:18.000000000 +0200
> @@ -96,6 +96,7 @@ int rt2x00mac_tx(struct ieee80211_hw *hw
> struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
> struct ieee80211_hdr *ieee80211hdr = (struct ieee80211_hdr *)skb->data;
> enum data_queue_qid qid = skb_get_queue_mapping(skb);
> + struct rt2x00_intf *intf = vif_to_intf(tx_info->control.vif);
> struct data_queue *queue;
> u16 frame_control;
>
> @@ -151,6 +152,18 @@ int rt2x00mac_tx(struct ieee80211_hw *hw
> }
> }
>
> + /*
> + * XXX: This is as wrong as the old mac80211 code was,
> + * due to beacons not getting sequence numbers assigned
> + * properly.
> + */
> + if (tx_info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ) {
> + if (tx_info->flags & IEEE80211_TX_CTL_FIRST_FRAGMENT)
> + intf->seqno += 0x10;
> + ieee80211hdr->seq_ctrl &= cpu_to_le16(IEEE80211_SCTL_FRAG);
> + ieee80211hdr->seq_ctrl |= cpu_to_le16(intf->seqno);
> + }
> +
> if (rt2x00queue_write_tx_frame(queue, skb)) {
> ieee80211_stop_queue(rt2x00dev->hw, qid);
> return NETDEV_TX_BUSY;
> --- everything.orig/drivers/net/wireless/b43legacy/xmit.c 2008-07-10 11:14:27.000000000 +0200
> +++ everything/drivers/net/wireless/b43legacy/xmit.c 2008-07-10 11:17:18.000000000 +0200
> @@ -295,8 +295,7 @@ static int generate_txhdr_fw3(struct b43
> /* MAC control */
> if (!(info->flags & IEEE80211_TX_CTL_NO_ACK))
> mac_ctl |= B43legacy_TX4_MAC_ACK;
> - if (!(((fctl & IEEE80211_FCTL_FTYPE) == IEEE80211_FTYPE_CTL) &&
> - ((fctl & IEEE80211_FCTL_STYPE) == IEEE80211_STYPE_PSPOLL)))
> + if (info->flags & IEEE80211_TX_CTL_ASSIGN_SEQ)
> mac_ctl |= B43legacy_TX4_MAC_HWSEQ;
> if (info->flags & IEEE80211_TX_CTL_FIRST_FRAGMENT)
> mac_ctl |= B43legacy_TX4_MAC_STMSDU;
>
>
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