mwifiex: improve uAP RX handling

1. Separate file for uAP RX handling.
2. If received packet is broadcast/multicast, send it to kernel
   as well as requeue it back to uAP TX queue.
3. If received packet is for associated STA (intra-BSS), requeue
   it back to uAP TX queue.
4. In all other cases (packets for AP or inter-BSS packets),
   pass packet to kernel to handle it accordingly.

Signed-off-by: Avinash Patil <patila@marvell.com>
Signed-off-by: Kiran Divekar <dkiran@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/mwifiex/Makefile

@@ -36,6 +36,7 @@ mwifiex-y += sta_event.o
 mwifiex-y += uap_event.o
 mwifiex-y += sta_tx.o
 mwifiex-y += sta_rx.o
+mwifiex-y += uap_txrx.o
 mwifiex-y += cfg80211.o
 mwifiex-$(CONFIG_DEBUG_FS) += debugfs.o
 obj-$(CONFIG_MWIFIEX) += mwifiex.o

drivers/net/wireless/mwifiex/decl.h

@@ -60,6 +60,9 @@
 #define MWIFIEX_SDIO_BLOCK_SIZE            256
 
 #define MWIFIEX_BUF_FLAG_REQUEUED_PKT      BIT(0)
+#define MWIFIEX_BUF_FLAG_BRIDGED_PKT	   BIT(1)
+
+#define MWIFIEX_BRIDGED_PKTS_THRESHOLD     1024
 
 enum mwifiex_bss_type {
 	MWIFIEX_BSS_TYPE_STA = 0,

drivers/net/wireless/mwifiex/fw.h

@@ -439,6 +439,31 @@ struct rxpd {
 	u8 reserved;
 } __packed;
 
+struct uap_txpd {
+	u8 bss_type;
+	u8 bss_num;
+	__le16 tx_pkt_length;
+	__le16 tx_pkt_offset;
+	__le16 tx_pkt_type;
+	__le32 tx_control;
+	u8 priority;
+	u8 flags;
+	u8 pkt_delay_2ms;
+	u8 reserved1;
+	__le32 reserved2;
+};
+
+struct uap_rxpd {
+	u8 bss_type;
+	u8 bss_num;
+	__le16 rx_pkt_length;
+	__le16 rx_pkt_offset;
+	__le16 rx_pkt_type;
+	__le16 seq_num;
+	u8 priority;
+	u8 reserved1;
+};
+
 enum mwifiex_chan_scan_mode_bitmasks {
 	MWIFIEX_PASSIVE_SCAN = BIT(0),
 	MWIFIEX_DISABLE_CHAN_FILT = BIT(1),

drivers/net/wireless/mwifiex/main.h

@@ -710,6 +710,7 @@ struct mwifiex_adapter {
 	u8 scan_delay_cnt;
 	u8 empty_tx_q_cnt;
 	atomic_t is_tx_received;
+	atomic_t pending_bridged_pkts;
 };
 
 int mwifiex_init_lock_list(struct mwifiex_adapter *adapter);
@@ -800,6 +801,10 @@ int mwifiex_process_sta_cmdresp(struct mwifiex_private *, u16 cmdresp_no,
 				struct host_cmd_ds_command *resp);
 int mwifiex_process_sta_rx_packet(struct mwifiex_adapter *,
 				  struct sk_buff *skb);
+int mwifiex_process_uap_rx_packet(struct mwifiex_adapter *adapter,
+				  struct sk_buff *skb);
+int mwifiex_handle_uap_rx_forward(struct mwifiex_private *priv,
+				  struct sk_buff *skb);
 int mwifiex_process_sta_event(struct mwifiex_private *);
 int mwifiex_process_uap_event(struct mwifiex_private *);
 struct mwifiex_sta_node *

drivers/net/wireless/mwifiex/txrx.c

@@ -51,6 +51,9 @@ int mwifiex_handle_rx_packet(struct mwifiex_adapter *adapter,
 	rx_info->bss_num = priv->bss_num;
 	rx_info->bss_type = priv->bss_type;
 
+	if (priv->bss_role == MWIFIEX_BSS_ROLE_UAP)
+		return mwifiex_process_uap_rx_packet(adapter, skb);
+
 	return mwifiex_process_sta_rx_packet(adapter, skb);
 }
 EXPORT_SYMBOL_GPL(mwifiex_handle_rx_packet);
@@ -157,6 +160,8 @@ int mwifiex_write_data_complete(struct mwifiex_adapter *adapter,
 		priv->stats.tx_errors++;
 	}
 
+	if (tx_info->flags & MWIFIEX_BUF_FLAG_BRIDGED_PKT)
+		atomic_dec_return(&adapter->pending_bridged_pkts);
 	if (atomic_dec_return(&adapter->tx_pending) >= LOW_TX_PENDING)
 		goto done;
 

drivers/net/wireless/mwifiex/uap_txrx.c

@@ -0,0 +1,205 @@
+/*
+ * Marvell Wireless LAN device driver: AP TX and RX data handling
+ *
+ * Copyright (C) 2012, Marvell International Ltd.
+ *
+ * This software file (the "File") is distributed by Marvell International
+ * Ltd. under the terms of the GNU General Public License Version 2, June 1991
+ * (the "License").  You may use, redistribute and/or modify this File in
+ * accordance with the terms and conditions of the License, a copy of which
+ * is available by writing to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or on the
+ * worldwide web at http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.
+ *
+ * THE FILE IS DISTRIBUTED AS-IS, WITHOUT WARRANTY OF ANY KIND, AND THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE
+ * ARE EXPRESSLY DISCLAIMED.  The License provides additional details about
+ * this warranty disclaimer.
+ */
+
+#include "decl.h"
+#include "ioctl.h"
+#include "main.h"
+#include "wmm.h"
+
+static void mwifiex_uap_queue_bridged_pkt(struct mwifiex_private *priv,
+					 struct sk_buff *skb)
+{
+	struct mwifiex_adapter *adapter = priv->adapter;
+	struct uap_rxpd *uap_rx_pd;
+	struct rx_packet_hdr *rx_pkt_hdr;
+	struct sk_buff *new_skb;
+	struct mwifiex_txinfo *tx_info;
+	int hdr_chop;
+	struct timeval tv;
+	u8 rfc1042_eth_hdr[ETH_ALEN] = { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };
+
+	uap_rx_pd = (struct uap_rxpd *)(skb->data);
+	rx_pkt_hdr = (void *)uap_rx_pd + le16_to_cpu(uap_rx_pd->rx_pkt_offset);
+
+	if ((atomic_read(&adapter->pending_bridged_pkts) >=
+					     MWIFIEX_BRIDGED_PKTS_THRESHOLD)) {
+		dev_err(priv->adapter->dev,
+			"Tx: Bridge packet limit reached. Drop packet!\n");
+		kfree_skb(skb);
+		return;
+	}
+
+	if (!memcmp(&rx_pkt_hdr->rfc1042_hdr,
+		    rfc1042_eth_hdr, sizeof(rfc1042_eth_hdr)))
+		/* Chop off the rxpd + the excess memory from
+		 * 802.2/llc/snap header that was removed.
+		 */
+		hdr_chop = (u8 *)eth_hdr - (u8 *)uap_rx_pd;
+	else
+		/* Chop off the rxpd */
+		hdr_chop = (u8 *)&rx_pkt_hdr->eth803_hdr - (u8 *)uap_rx_pd;
+
+	/* Chop off the leading header bytes so the it points
+	 * to the start of either the reconstructed EthII frame
+	 * or the 802.2/llc/snap frame.
+	 */
+	skb_pull(skb, hdr_chop);
+
+	if (skb_headroom(skb) < MWIFIEX_MIN_DATA_HEADER_LEN) {
+		dev_dbg(priv->adapter->dev,
+			"data: Tx: insufficient skb headroom %d\n",
+			skb_headroom(skb));
+		/* Insufficient skb headroom - allocate a new skb */
+		new_skb =
+			skb_realloc_headroom(skb, MWIFIEX_MIN_DATA_HEADER_LEN);
+		if (unlikely(!new_skb)) {
+			dev_err(priv->adapter->dev,
+				"Tx: cannot allocate new_skb\n");
+			kfree_skb(skb);
+			priv->stats.tx_dropped++;
+			return;
+		}
+
+		kfree_skb(skb);
+		skb = new_skb;
+		dev_dbg(priv->adapter->dev, "info: new skb headroom %d\n",
+			skb_headroom(skb));
+	}
+
+	tx_info = MWIFIEX_SKB_TXCB(skb);
+	tx_info->bss_num = priv->bss_num;
+	tx_info->bss_type = priv->bss_type;
+	tx_info->flags |= MWIFIEX_BUF_FLAG_BRIDGED_PKT;
+
+	do_gettimeofday(&tv);
+	skb->tstamp = timeval_to_ktime(tv);
+	mwifiex_wmm_add_buf_txqueue(priv, skb);
+	atomic_inc(&adapter->tx_pending);
+	atomic_inc(&adapter->pending_bridged_pkts);
+
+	if ((atomic_read(&adapter->tx_pending) >= MAX_TX_PENDING)) {
+		mwifiex_set_trans_start(priv->netdev);
+		mwifiex_stop_net_dev_queue(priv->netdev, priv->adapter);
+	}
+	return;
+}
+
+/*
+ * This function contains logic for AP packet forwarding.
+ *
+ * If a packet is multicast/broadcast, it is sent to kernel/upper layer
+ * as well as queued back to AP TX queue so that it can be sent to other
+ * associated stations.
+ * If a packet is unicast and RA is present in associated station list,
+ * it is again requeued into AP TX queue.
+ * If a packet is unicast and RA is not in associated station list,
+ * packet is forwarded to kernel to handle routing logic.
+ */
+int mwifiex_handle_uap_rx_forward(struct mwifiex_private *priv,
+				  struct sk_buff *skb)
+{
+	struct mwifiex_adapter *adapter = priv->adapter;
+	struct uap_rxpd *uap_rx_pd;
+	struct rx_packet_hdr *rx_pkt_hdr;
+	u8 ra[ETH_ALEN];
+	struct sk_buff *skb_uap;
+
+	uap_rx_pd = (struct uap_rxpd *)(skb->data);
+	rx_pkt_hdr = (void *)uap_rx_pd + le16_to_cpu(uap_rx_pd->rx_pkt_offset);
+
+	/* don't do packet forwarding in disconnected state */
+	if (!priv->media_connected) {
+		dev_err(adapter->dev, "drop packet in disconnected state.\n");
+		dev_kfree_skb_any(skb);
+		return 0;
+	}
+
+	memcpy(ra, rx_pkt_hdr->eth803_hdr.h_dest, ETH_ALEN);
+
+	if (is_multicast_ether_addr(ra)) {
+		skb_uap = skb_copy(skb, GFP_ATOMIC);
+		mwifiex_uap_queue_bridged_pkt(priv, skb_uap);
+	} else {
+		if (mwifiex_get_sta_entry(priv, ra)) {
+			/* Requeue Intra-BSS packet */
+			mwifiex_uap_queue_bridged_pkt(priv, skb);
+			return 0;
+		}
+	}
+
+	/* Forward unicat/Inter-BSS packets to kernel. */
+	return mwifiex_process_rx_packet(adapter, skb);
+}
+
+/*
+ * This function processes the packet received on AP interface.
+ *
+ * The function looks into the RxPD and performs sanity tests on the
+ * received buffer to ensure its a valid packet before processing it
+ * further. If the packet is determined to be aggregated, it is
+ * de-aggregated accordingly. Then skb is passed to AP packet forwarding logic.
+ *
+ * The completion callback is called after processing is complete.
+ */
+int mwifiex_process_uap_rx_packet(struct mwifiex_adapter *adapter,
+				  struct sk_buff *skb)
+{
+	int ret;
+	struct uap_rxpd *uap_rx_pd;
+	struct mwifiex_rxinfo *rx_info = MWIFIEX_SKB_RXCB(skb);
+	struct rx_packet_hdr *rx_pkt_hdr;
+	u16 rx_pkt_type;
+	struct mwifiex_private *priv =
+			mwifiex_get_priv_by_id(adapter, rx_info->bss_num,
+					       rx_info->bss_type);
+
+	if (!priv)
+		return -1;
+
+	uap_rx_pd = (struct uap_rxpd *)(skb->data);
+	rx_pkt_type = le16_to_cpu(uap_rx_pd->rx_pkt_type);
+	rx_pkt_hdr = (void *)uap_rx_pd + le16_to_cpu(uap_rx_pd->rx_pkt_offset);
+
+	if ((le16_to_cpu(uap_rx_pd->rx_pkt_offset) +
+	     le16_to_cpu(uap_rx_pd->rx_pkt_length)) > (u16) skb->len) {
+		dev_err(adapter->dev,
+			"wrong rx packet: len=%d, offset=%d, length=%d\n",
+			skb->len, le16_to_cpu(uap_rx_pd->rx_pkt_offset),
+			le16_to_cpu(uap_rx_pd->rx_pkt_length));
+		priv->stats.rx_dropped++;
+
+		if (adapter->if_ops.data_complete)
+			adapter->if_ops.data_complete(adapter, skb);
+		else
+			dev_kfree_skb_any(skb);
+
+		return 0;
+	}
+	ret = mwifiex_handle_uap_rx_forward(priv, skb);
+
+	if (ret) {
+		priv->stats.rx_dropped++;
+		if (adapter->if_ops.data_complete)
+			adapter->if_ops.data_complete(adapter, skb);
+		else
+			dev_kfree_skb_any(skb);
+	}
+
+	return ret;
+}