/*
 * NXP Wireless LAN device driver: station RX data handling
 *
 * Copyright 2011-2020 NXP
 *
 * This software file (the "File") is distributed by NXP
 * 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 <uapi/linux/ipv6.h>
#include <net/ndisc.h>
#include "decl.h"
#include "ioctl.h"
#include "util.h"
#include "fw.h"
#include "main.h"
#include "11n_aggr.h"
#include "11n_rxreorder.h"

/* This function checks if a frame is IPv4 ARP or IPv6 Neighbour advertisement
 * frame. If frame has both source and destination mac address as same, this
 * function drops such gratuitous frames.
 */
static bool
mwifiex_discard_gratuitous_arp(struct mwifiex_private *priv,
                               struct sk_buff *skb)
{
        const struct mwifiex_arp_eth_header *arp;
        struct ethhdr *eth;
        struct ipv6hdr *ipv6;
        struct icmp6hdr *icmpv6;

        eth = (struct ethhdr *)skb->data;
        switch (ntohs(eth->h_proto)) {
        case ETH_P_ARP:
                arp = (void *)(skb->data + sizeof(struct ethhdr));
                if (arp->hdr.ar_op == htons(ARPOP_REPLY) ||
                    arp->hdr.ar_op == htons(ARPOP_REQUEST)) {
                        if (!memcmp(arp->ar_sip, arp->ar_tip, 4))
                                return true;
                }
                break;
        case ETH_P_IPV6:
                ipv6 = (void *)(skb->data + sizeof(struct ethhdr));
                icmpv6 = (void *)(skb->data + sizeof(struct ethhdr) +
                                  sizeof(struct ipv6hdr));
                if (NDISC_NEIGHBOUR_ADVERTISEMENT == icmpv6->icmp6_type) {
                        if (!memcmp(&ipv6->saddr, &ipv6->daddr,
                                    sizeof(struct in6_addr)))
                                return true;
                }
                break;
        default:
                break;
        }

        return false;
}

/*
 * This function processes the received packet and forwards it
 * to kernel/upper layer.
 *
 * This function parses through the received packet and determines
 * if it is a debug packet or normal packet.
 *
 * For non-debug packets, the function chops off unnecessary leading
 * header bytes, reconstructs the packet as an ethernet frame or
 * 802.2/llc/snap frame as required, and sends it to kernel/upper layer.
 *
 * The completion callback is called after processing in complete.
 */
int mwifiex_process_rx_packet(struct mwifiex_private *priv,
                              struct sk_buff *skb)
{
        int ret;
        struct rx_packet_hdr *rx_pkt_hdr;
        struct rxpd *local_rx_pd;
        int hdr_chop;
        struct ethhdr *eth;
        u16 rx_pkt_off, rx_pkt_len;
        u8 *offset;
        u8 adj_rx_rate = 0;

        local_rx_pd = (struct rxpd *) (skb->data);

        rx_pkt_off = le16_to_cpu(local_rx_pd->rx_pkt_offset);
        rx_pkt_len = le16_to_cpu(local_rx_pd->rx_pkt_length);
        rx_pkt_hdr = (void *)local_rx_pd + rx_pkt_off;

        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
                 *    EthernetII 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.
                 */
                eth = (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(eth->h_source, rx_pkt_hdr->eth803_hdr.h_source,
                       sizeof(eth->h_source));
                memcpy(eth->h_dest, rx_pkt_hdr->eth803_hdr.h_dest,
                       sizeof(eth->h_dest));

                /* Chop off the rxpd + the excess memory from the 802.2/llc/snap
                   header that was removed. */
                hdr_chop = (u8 *) eth - (u8 *) local_rx_pd;
        } else {
                /* Chop off the rxpd */
                hdr_chop = (u8 *) &rx_pkt_hdr->eth803_hdr -
                        (u8 *) local_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 (priv->hs2_enabled &&
            mwifiex_discard_gratuitous_arp(priv, skb)) {
                mwifiex_dbg(priv->adapter, INFO, "Bypassed Gratuitous ARP\n");
                dev_kfree_skb_any(skb);
                return 0;
        }

        if (ISSUPP_TDLS_ENABLED(priv->adapter->fw_cap_info) &&
            ntohs(rx_pkt_hdr->eth803_hdr.h_proto) == ETH_P_TDLS) {
                offset = (u8 *)local_rx_pd + rx_pkt_off;
                mwifiex_process_tdls_action_frame(priv, offset, rx_pkt_len);
        }

        /* Only stash RX bitrate for unicast packets. */
        if (likely(!is_multicast_ether_addr(rx_pkt_hdr->eth803_hdr.h_dest))) {
                priv->rxpd_rate = local_rx_pd->rx_rate;
                priv->rxpd_htinfo = local_rx_pd->ht_info;
        }

        if (GET_BSS_ROLE(priv) == MWIFIEX_BSS_ROLE_STA ||
            GET_BSS_ROLE(priv) == MWIFIEX_BSS_ROLE_UAP) {
                adj_rx_rate = mwifiex_adjust_data_rate(priv,
                                                       local_rx_pd->rx_rate,
                                                       local_rx_pd->ht_info);
                mwifiex_hist_data_add(priv, adj_rx_rate, local_rx_pd->snr,
                                      local_rx_pd->nf);
        }

        ret = mwifiex_recv_packet(priv, skb);
        if (ret == -1)
                mwifiex_dbg(priv->adapter, ERROR,
                            "recv packet failed\n");

        return ret;
}

/*
 * This function processes the received buffer.
 *
 * 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. Non-unicast packets are sent directly to
 * the kernel/upper layers. Unicast packets are handed over to the
 * Rx reordering routine if 11n is enabled.
 *
 * The completion callback is called after processing in complete.
 */
int mwifiex_process_sta_rx_packet(struct mwifiex_private *priv,
                                  struct sk_buff *skb)
{
        struct mwifiex_adapter *adapter = priv->adapter;
        int ret = 0;
        struct rxpd *local_rx_pd;
        struct rx_packet_hdr *rx_pkt_hdr;
        u8 ta[ETH_ALEN];
        u16 rx_pkt_type, rx_pkt_offset, rx_pkt_length, seq_num;
        struct mwifiex_sta_node *sta_ptr;

        local_rx_pd = (struct rxpd *) (skb->data);
        rx_pkt_type = le16_to_cpu(local_rx_pd->rx_pkt_type);
        rx_pkt_offset = le16_to_cpu(local_rx_pd->rx_pkt_offset);
        rx_pkt_length = le16_to_cpu(local_rx_pd->rx_pkt_length);
        seq_num = le16_to_cpu(local_rx_pd->seq_num);

        rx_pkt_hdr = (void *)local_rx_pd + rx_pkt_offset;

        if ((rx_pkt_offset + rx_pkt_length) > (u16) skb->len) {
                mwifiex_dbg(adapter, ERROR,
                            "wrong rx packet: len=%d, rx_pkt_offset=%d, rx_pkt_length=%d\n",
                            skb->len, rx_pkt_offset, rx_pkt_length);
                priv->stats.rx_dropped++;
                dev_kfree_skb_any(skb);
                return ret;
        }

        if (rx_pkt_type == PKT_TYPE_MGMT) {
                ret = mwifiex_process_mgmt_packet(priv, skb);
                if (ret)
                        mwifiex_dbg(adapter, DATA, "Rx of mgmt packet failed");
                dev_kfree_skb_any(skb);
                return ret;
        }

        /*
         * If the packet is not an unicast packet then send the packet
         * directly to os. Don't pass thru rx reordering
         */
        if ((!IS_11N_ENABLED(priv) &&
             !(ISSUPP_TDLS_ENABLED(priv->adapter->fw_cap_info) &&
               !(local_rx_pd->flags & MWIFIEX_RXPD_FLAGS_TDLS_PACKET))) ||
            !ether_addr_equal_unaligned(priv->curr_addr, rx_pkt_hdr->eth803_hdr.h_dest)) {
                mwifiex_process_rx_packet(priv, skb);
                return ret;
        }

        if (mwifiex_queuing_ra_based(priv) ||
            (ISSUPP_TDLS_ENABLED(priv->adapter->fw_cap_info) &&
             local_rx_pd->flags & MWIFIEX_RXPD_FLAGS_TDLS_PACKET)) {
                memcpy(ta, rx_pkt_hdr->eth803_hdr.h_source, ETH_ALEN);
                if (local_rx_pd->flags & MWIFIEX_RXPD_FLAGS_TDLS_PACKET &&
                    local_rx_pd->priority < MAX_NUM_TID) {
                        sta_ptr = mwifiex_get_sta_entry(priv, ta);
                        if (sta_ptr)
                                sta_ptr->rx_seq[local_rx_pd->priority] =
                                              le16_to_cpu(local_rx_pd->seq_num);
                        mwifiex_auto_tdls_update_peer_signal(priv, ta,
                                                             local_rx_pd->snr,
                                                             local_rx_pd->nf);
                }
        } else {
                if (rx_pkt_type != PKT_TYPE_BAR &&
                    local_rx_pd->priority < MAX_NUM_TID)
                        priv->rx_seq[local_rx_pd->priority] = seq_num;
                memcpy(ta, priv->curr_bss_params.bss_descriptor.mac_address,
                       ETH_ALEN);
        }

        /* Reorder and send to OS */
        ret = mwifiex_11n_rx_reorder_pkt(priv, seq_num, local_rx_pd->priority,
                                         ta, (u8) rx_pkt_type, skb);

        if (ret || (rx_pkt_type == PKT_TYPE_BAR))
                dev_kfree_skb_any(skb);

        if (ret)
                priv->stats.rx_dropped++;

        return ret;
}