/*
   * Marvell Wireless LAN device driver: AP TX and RX data handling
   *
   * Copyright (C) 2012-2014, 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"
  #include "11n_aggr.h"
  #include "11n_rxreorder.h"
  
  /* This function checks if particular RA list has packets more than low bridge
   * packet threshold and then deletes packet from this RA list.
   * Function deletes packets from such RA list and returns true. If no such list
   * is found, false is returned.
   */
  static bool
  mwifiex_uap_del_tx_pkts_in_ralist(struct mwifiex_private *priv,
  				  struct list_head *ra_list_head,
  				  int tid)
  {
  	struct mwifiex_ra_list_tbl *ra_list;
  	struct sk_buff *skb, *tmp;
  	bool pkt_deleted = false;
  	struct mwifiex_txinfo *tx_info;
  	struct mwifiex_adapter *adapter = priv->adapter;
  
  	list_for_each_entry(ra_list, ra_list_head, list) {
  		if (skb_queue_empty(&ra_list->skb_head))
  			continue;
  
  		skb_queue_walk_safe(&ra_list->skb_head, skb, tmp) {
  			tx_info = MWIFIEX_SKB_TXCB(skb);
  			if (tx_info->flags & MWIFIEX_BUF_FLAG_BRIDGED_PKT) {
  				__skb_unlink(skb, &ra_list->skb_head);
  				mwifiex_write_data_complete(adapter, skb, 0,
  							    -1);
  				if (ra_list->tx_paused)
  					priv->wmm.pkts_paused[tid]--;
  				else
  					atomic_dec(&priv->wmm.tx_pkts_queued);
  				pkt_deleted = true;
  			}
  			if ((atomic_read(&adapter->pending_bridged_pkts) <=
  					     MWIFIEX_BRIDGED_PKTS_THR_LOW))
  				break;
  		}
  	}
  
  	return pkt_deleted;
  }
  
  /* This function deletes packets from particular RA List. RA list index
   * from which packets are deleted is preserved so that packets from next RA
   * list are deleted upon subsequent call thus maintaining fairness.
   */
  static void mwifiex_uap_cleanup_tx_queues(struct mwifiex_private *priv)
  {
  	unsigned long flags;
  	struct list_head *ra_list;
  	int i;
  
  	spin_lock_irqsave(&priv->wmm.ra_list_spinlock, flags);
  
  	for (i = 0; i < MAX_NUM_TID; i++, priv->del_list_idx++) {
  		if (priv->del_list_idx == MAX_NUM_TID)
  			priv->del_list_idx = 0;
  		ra_list = &priv->wmm.tid_tbl_ptr[priv->del_list_idx].ra_list;
  		if (mwifiex_uap_del_tx_pkts_in_ralist(priv, ra_list, i)) {
  			priv->del_list_idx++;
  			break;
  		}
  	}
  
  	spin_unlock_irqrestore(&priv->wmm.ra_list_spinlock, flags);
  }
  
  
  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 ethhdr *p_ethhdr;
  	struct mwifiex_sta_node *src_node;
  
  	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_THR_HIGH)) {
  		mwifiex_dbg(priv->adapter, ERROR,
  			    "Tx: Bridge packet limit reached. Drop packet!
  ");
  		kfree_skb(skb);
  		mwifiex_uap_cleanup_tx_queues(priv);
  		return;
  	}
  
  	if ((!memcmp(&rx_pkt_hdr->rfc1042_hdr, bridge_tunnel_header,
  		     sizeof(bridge_tunnel_header))) ||
  	    (!memcmp(&rx_pkt_hdr->rfc1042_hdr, rfc1042_header,
  		     sizeof(rfc1042_header)) &&
  	     ntohs(rx_pkt_hdr->rfc1042_hdr.snap_type) != ETH_P_AARP &&
  	     ntohs(rx_pkt_hdr->rfc1042_hdr.snap_type) != ETH_P_IPX)) {
  		/* Replace the 803 header and rfc1042 header (llc/snap) with
  		 * an Ethernet II header, keep the src/dst and snap_type
  		 * (ethertype).
  		 *
  		 * The firmware only passes up SNAP frames converting all RX
  		 * data from 802.11 to 802.2/LLC/SNAP frames.
  		 *
  		 * To create the Ethernet II, just move the src, dst address
  		 * right before the snap_type.
  		 */
  		p_ethhdr = (struct ethhdr *)
  			((u8 *)(&rx_pkt_hdr->eth803_hdr)
  			 + sizeof(rx_pkt_hdr->eth803_hdr)
  			 + sizeof(rx_pkt_hdr->rfc1042_hdr)
  			 - sizeof(rx_pkt_hdr->eth803_hdr.h_dest)
  			 - sizeof(rx_pkt_hdr->eth803_hdr.h_source)
  			 - sizeof(rx_pkt_hdr->rfc1042_hdr.snap_type));
  		memcpy(p_ethhdr->h_source, rx_pkt_hdr->eth803_hdr.h_source,
  		       sizeof(p_ethhdr->h_source));
  		memcpy(p_ethhdr->h_dest, rx_pkt_hdr->eth803_hdr.h_dest,
  		       sizeof(p_ethhdr->h_dest));
  		/* Chop off the rxpd + the excess memory from
  		 * 802.2/llc/snap header that was removed.
  		 */
  		hdr_chop = (u8 *)p_ethhdr - (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 that 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) {
  		mwifiex_dbg(priv->adapter, ERROR,
  			    "data: Tx: insufficient skb headroom %d
  ",
  			    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)) {
  			mwifiex_dbg(priv->adapter, ERROR,
  				    "Tx: cannot allocate new_skb
  ");
  			kfree_skb(skb);
  			priv->stats.tx_dropped++;
  			return;
  		}
  
  		kfree_skb(skb);
  		skb = new_skb;
  		mwifiex_dbg(priv->adapter, INFO,
  			    "info: new skb headroom %d
  ",
  			    skb_headroom(skb));
  	}
  
  	tx_info = MWIFIEX_SKB_TXCB(skb);
  	memset(tx_info, 0, sizeof(*tx_info));
  	tx_info->bss_num = priv->bss_num;
  	tx_info->bss_type = priv->bss_type;
  	tx_info->flags |= MWIFIEX_BUF_FLAG_BRIDGED_PKT;
  
  	src_node = mwifiex_get_sta_entry(priv, rx_pkt_hdr->eth803_hdr.h_source);
  	if (src_node) {
  		src_node->stats.last_rx = jiffies;
  		src_node->stats.rx_bytes += skb->len;
  		src_node->stats.rx_packets++;
  		src_node->stats.last_tx_rate = uap_rx_pd->rx_rate;
  		src_node->stats.last_tx_htinfo = uap_rx_pd->ht_info;
  	}
  
  	if (is_unicast_ether_addr(rx_pkt_hdr->eth803_hdr.h_dest)) {
  		/* Update bridge packet statistics as the
  		 * packet is not going to kernel/upper layer.
  		 */
  		priv->stats.rx_bytes += skb->len;
  		priv->stats.rx_packets++;
  
  		/* Sending bridge packet to TX queue, so save the packet
  		 * length in TXCB to update statistics in TX complete.
  		 */
  		tx_info->pkt_len = skb->len;
  	}
  
  	__net_timestamp(skb);
  	mwifiex_wmm_add_buf_txqueue(priv, skb);
  	atomic_inc(&adapter->tx_pending);
  	atomic_inc(&adapter->pending_bridged_pkts);
  
  	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) {
  		mwifiex_dbg(adapter, ERROR,
  			    "drop packet in disconnected state.
  ");
  		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(priv, 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_private *priv,
  				  struct sk_buff *skb)
  {
  	struct mwifiex_adapter *adapter = priv->adapter;
  	int ret;
  	struct uap_rxpd *uap_rx_pd;
  	struct rx_packet_hdr *rx_pkt_hdr;
  	u16 rx_pkt_type;
  	u8 ta[ETH_ALEN], pkt_type;
  	unsigned long flags;
  	struct mwifiex_sta_node *node;
  
  	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);
  
  	ether_addr_copy(ta, rx_pkt_hdr->eth803_hdr.h_source);
  
  	if ((le16_to_cpu(uap_rx_pd->rx_pkt_offset) +
  	     le16_to_cpu(uap_rx_pd->rx_pkt_length)) > (u16) skb->len) {
  		mwifiex_dbg(adapter, ERROR,
  			    "wrong rx packet: len=%d, offset=%d, length=%d
  ",
  			    skb->len, le16_to_cpu(uap_rx_pd->rx_pkt_offset),
  			    le16_to_cpu(uap_rx_pd->rx_pkt_length));
  		priv->stats.rx_dropped++;
  
  		node = mwifiex_get_sta_entry(priv, ta);
  		if (node)
  			node->stats.tx_failed++;
  
  		dev_kfree_skb_any(skb);
  		return 0;
  	}
  
  	if (rx_pkt_type == PKT_TYPE_MGMT) {
  		ret = mwifiex_process_mgmt_packet(priv, skb);
  		if (ret)
  			mwifiex_dbg(adapter, ERROR,
  				    "Rx of mgmt packet failed");
  		dev_kfree_skb_any(skb);
  		return ret;
  	}
  
  
  	if (rx_pkt_type != PKT_TYPE_BAR && uap_rx_pd->priority < MAX_NUM_TID) {
  		spin_lock_irqsave(&priv->sta_list_spinlock, flags);
  		node = mwifiex_get_sta_entry(priv, ta);
  		if (node)
  			node->rx_seq[uap_rx_pd->priority] =
  						le16_to_cpu(uap_rx_pd->seq_num);
  		spin_unlock_irqrestore(&priv->sta_list_spinlock, flags);
  	}
  
  	if (!priv->ap_11n_enabled ||
  	    (!mwifiex_11n_get_rx_reorder_tbl(priv, uap_rx_pd->priority, ta) &&
  	    (le16_to_cpu(uap_rx_pd->rx_pkt_type) != PKT_TYPE_AMSDU))) {
  		ret = mwifiex_handle_uap_rx_forward(priv, skb);
  		return ret;
  	}
  
  	/* Reorder and send to kernel */
  	pkt_type = (u8)le16_to_cpu(uap_rx_pd->rx_pkt_type);
  	ret = mwifiex_11n_rx_reorder_pkt(priv, le16_to_cpu(uap_rx_pd->seq_num),
  					 uap_rx_pd->priority, ta, pkt_type,
  					 skb);
  
  	if (ret || (rx_pkt_type == PKT_TYPE_BAR))
  		dev_kfree_skb_any(skb);
  
  	if (ret)
  		priv->stats.rx_dropped++;
  
  	return ret;
  }
  
  /*
   * This function fills the TxPD for AP tx packets.
   *
   * The Tx buffer received by this function should already have the
   * header space allocated for TxPD.
   *
   * This function inserts the TxPD in between interface header and actual
   * data and adjusts the buffer pointers accordingly.
   *
   * The following TxPD fields are set by this function, as required -
   *      - BSS number
   *      - Tx packet length and offset
   *      - Priority
   *      - Packet delay
   *      - Priority specific Tx control
   *      - Flags
   */
  void *mwifiex_process_uap_txpd(struct mwifiex_private *priv,
  			       struct sk_buff *skb)
  {
  	struct mwifiex_adapter *adapter = priv->adapter;
  	struct uap_txpd *txpd;
  	struct mwifiex_txinfo *tx_info = MWIFIEX_SKB_TXCB(skb);
  	int pad;
  	u16 pkt_type, pkt_offset;
  	int hroom = (priv->adapter->iface_type == MWIFIEX_USB) ? 0 :
  		       INTF_HEADER_LEN;
  
  	if (!skb->len) {
  		mwifiex_dbg(adapter, ERROR,
  			    "Tx: bad packet length: %d
  ", skb->len);
  		tx_info->status_code = -1;
  		return skb->data;
  	}
  
  	BUG_ON(skb_headroom(skb) < MWIFIEX_MIN_DATA_HEADER_LEN);
  
  	pkt_type = mwifiex_is_skb_mgmt_frame(skb) ? PKT_TYPE_MGMT : 0;
  
  	pad = ((void *)skb->data - (sizeof(*txpd) + hroom) - NULL) &
  			(MWIFIEX_DMA_ALIGN_SZ - 1);
  
  	skb_push(skb, sizeof(*txpd) + pad);
  
  	txpd = (struct uap_txpd *)skb->data;
  	memset(txpd, 0, sizeof(*txpd));
  	txpd->bss_num = priv->bss_num;
  	txpd->bss_type = priv->bss_type;
  	txpd->tx_pkt_length = cpu_to_le16((u16)(skb->len - (sizeof(*txpd) +
  						pad)));
  	txpd->priority = (u8)skb->priority;
  
  	txpd->pkt_delay_2ms = mwifiex_wmm_compute_drv_pkt_delay(priv, skb);
  
  	if (tx_info->flags & MWIFIEX_BUF_FLAG_EAPOL_TX_STATUS ||
  	    tx_info->flags & MWIFIEX_BUF_FLAG_ACTION_TX_STATUS) {
  		txpd->tx_token_id = tx_info->ack_frame_id;
  		txpd->flags |= MWIFIEX_TXPD_FLAGS_REQ_TX_STATUS;
  	}
  
  	if (txpd->priority < ARRAY_SIZE(priv->wmm.user_pri_pkt_tx_ctrl))
  		/*
  		 * Set the priority specific tx_control field, setting of 0 will
  		 * cause the default value to be used later in this function.
  		 */
  		txpd->tx_control =
  		    cpu_to_le32(priv->wmm.user_pri_pkt_tx_ctrl[txpd->priority]);
  
  	/* Offset of actual data */
  	pkt_offset = sizeof(*txpd) + pad;
  	if (pkt_type == PKT_TYPE_MGMT) {
  		/* Set the packet type and add header for management frame */
  		txpd->tx_pkt_type = cpu_to_le16(pkt_type);
  		pkt_offset += MWIFIEX_MGMT_FRAME_HEADER_SIZE;
  	}
  
  	txpd->tx_pkt_offset = cpu_to_le16(pkt_offset);
  
  	/* make space for INTF_HEADER_LEN */
  	skb_push(skb, hroom);
  
  	if (!txpd->tx_control)
  		/* TxCtrl set by user or default */
  		txpd->tx_control = cpu_to_le32(priv->pkt_tx_ctrl);
  
  	return skb->data;
  }