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>

6 files changed, 244 insertions, 0 deletions

diff --git a/drivers/net/wireless/mwifiex/Makefile b/drivers/net/wireless/mwifiex/Makefile
index 20932f24dc23..dd0410d2d465 100644
--- a/drivers/net/wireless/mwifiex/Makefile
+++ b/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
diff --git a/drivers/net/wireless/mwifiex/decl.h b/drivers/net/wireless/mwifiex/decl.h
index 070ef25f5186..400d360ac91f 100644
--- a/drivers/net/wireless/mwifiex/decl.h
+++ b/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,
diff --git a/drivers/net/wireless/mwifiex/fw.h b/drivers/net/wireless/mwifiex/fw.h
index a0222ec1cc38..1c1274d8d789 100644
--- a/drivers/net/wireless/mwifiex/fw.h
+++ b/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),
diff --git a/drivers/net/wireless/mwifiex/main.h b/drivers/net/wireless/mwifiex/main.h
index 9a0174d06460..014fe9ab221f 100644
--- a/drivers/net/wireless/mwifiex/main.h
+++ b/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 *
diff --git a/drivers/net/wireless/mwifiex/txrx.c b/drivers/net/wireless/mwifiex/txrx.c
index cecb27283196..985073d0df1a 100644
--- a/drivers/net/wireless/mwifiex/txrx.c
+++ b/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;
 
diff --git a/drivers/net/wireless/mwifiex/uap_txrx.c b/drivers/net/wireless/mwifiex/uap_txrx.c
new file mode 100644
index 000000000000..f55c5ac3e5e0
--- /dev/null
+++ b/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;
+}