drivers/net/wireless/libertas/rx.c

   1 /**
   2   * This file contains the handling of RX in wlan driver.
   3   */
   4 #include <linux/etherdevice.h>
   5 #include <linux/slab.h>
   6 #include <linux/types.h>
   7 #include <net/cfg80211.h>
   8
   9 #include "defs.h"
  10 #include "host.h"
  11 #include "radiotap.h"
  12 #include "decl.h"
  13 #include "dev.h"
  14
  15 struct eth803hdr {
  16         u8 dest_addr[6];
  17         u8 src_addr[6];
  18         u16 h803_len;
  19 } __packed;
  20
  21 struct rfc1042hdr {
  22         u8 llc_dsap;
  23         u8 llc_ssap;
  24         u8 llc_ctrl;
  25         u8 snap_oui[3];
  26         u16 snap_type;
  27 } __packed;
  28
  29 struct rxpackethdr {
  30         struct eth803hdr eth803_hdr;
  31         struct rfc1042hdr rfc1042_hdr;
  32 } __packed;
  33
  34 struct rx80211packethdr {
  35         struct rxpd rx_pd;
  36         void *eth80211_hdr;
  37 } __packed;
  38
  39 static int process_rxed_802_11_packet(struct lbs_private *priv,
  40         struct sk_buff *skb);
  41
  42 /**
  43  *  @brief This function processes received packet and forwards it
  44  *  to kernel/upper layer
  45  *
  46  *  @param      priv    A pointer to struct lbs_private
  47  *  @param      skb             A pointer to skb which includes the received packet
  48  *  @return     0 or -1
  49  */
  50 int lbs_process_rxed_packet(struct lbs_private *priv, struct sk_buff *skb)
  51 {
  52         int ret = 0;
  53         struct net_device *dev = priv->dev;
  54         struct rxpackethdr *p_rx_pkt;
  55         struct rxpd *p_rx_pd;
  56         int hdrchop;
  57         struct ethhdr *p_ethhdr;
  58         static const u8 rfc1042_eth_hdr[] = {
  59                 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00
  60         };
  61
  62         lbs_deb_enter(LBS_DEB_RX);
  63
  64         BUG_ON(!skb);
  65
  66         skb->ip_summed = CHECKSUM_NONE;
  67
  68         if (priv->wdev->iftype == NL80211_IFTYPE_MONITOR)
  69                 return process_rxed_802_11_packet(priv, skb);
  70
  71         p_rx_pd = (struct rxpd *) skb->data;
  72         p_rx_pkt = (struct rxpackethdr *) ((u8 *)p_rx_pd +
  73                 le32_to_cpu(p_rx_pd->pkt_ptr));
  74
  75         dev = lbs_mesh_set_dev(priv, dev, p_rx_pd);
  76
  77         lbs_deb_hex(LBS_DEB_RX, "RX Data: Before chop rxpd", skb->data,
  78                  min_t(unsigned int, skb->len, 100));
  79
  80         if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) {
  81                 lbs_deb_rx("rx err: frame received with bad length\n");
  82                 dev->stats.rx_length_errors++;
  83                 ret = 0;
  84                 dev_kfree_skb(skb);
  85                 goto done;
  86         }
  87
  88         lbs_deb_rx("rx data: skb->len - pkt_ptr = %d-%zd = %zd\n",
  89                 skb->len, (size_t)le32_to_cpu(p_rx_pd->pkt_ptr),
  90                 skb->len - (size_t)le32_to_cpu(p_rx_pd->pkt_ptr));
  91
  92         lbs_deb_hex(LBS_DEB_RX, "RX Data: Dest", p_rx_pkt->eth803_hdr.dest_addr,
  93                 sizeof(p_rx_pkt->eth803_hdr.dest_addr));
  94         lbs_deb_hex(LBS_DEB_RX, "RX Data: Src", p_rx_pkt->eth803_hdr.src_addr,
  95                 sizeof(p_rx_pkt->eth803_hdr.src_addr));
  96
  97         if (memcmp(&p_rx_pkt->rfc1042_hdr,
  98                    rfc1042_eth_hdr, sizeof(rfc1042_eth_hdr)) == 0) {
  99                 /*
 100                  *  Replace the 803 header and rfc1042 header (llc/snap) with an
 101                  *    EthernetII header, keep the src/dst and snap_type (ethertype)
 102                  *
 103                  *  The firmware only passes up SNAP frames converting
 104                  *    all RX Data from 802.11 to 802.2/LLC/SNAP frames.
 105                  *
 106                  *  To create the Ethernet II, just move the src, dst address right
 107                  *    before the snap_type.
 108                  */
 109                 p_ethhdr = (struct ethhdr *)
 110                     ((u8 *) &p_rx_pkt->eth803_hdr
 111                      + sizeof(p_rx_pkt->eth803_hdr) + sizeof(p_rx_pkt->rfc1042_hdr)
 112                      - sizeof(p_rx_pkt->eth803_hdr.dest_addr)
 113                      - sizeof(p_rx_pkt->eth803_hdr.src_addr)
 114                      - sizeof(p_rx_pkt->rfc1042_hdr.snap_type));
 115
 116                 memcpy(p_ethhdr->h_source, p_rx_pkt->eth803_hdr.src_addr,
 117                        sizeof(p_ethhdr->h_source));
 118                 memcpy(p_ethhdr->h_dest, p_rx_pkt->eth803_hdr.dest_addr,
 119                        sizeof(p_ethhdr->h_dest));
 120
 121                 /* Chop off the rxpd + the excess memory from the 802.2/llc/snap header
 122                  *   that was removed
 123                  */
 124                 hdrchop = (u8 *)p_ethhdr - (u8 *)p_rx_pd;
 125         } else {
 126                 lbs_deb_hex(LBS_DEB_RX, "RX Data: LLC/SNAP",
 127                         (u8 *) &p_rx_pkt->rfc1042_hdr,
 128                         sizeof(p_rx_pkt->rfc1042_hdr));
 129
 130                 /* Chop off the rxpd */
 131                 hdrchop = (u8 *)&p_rx_pkt->eth803_hdr - (u8 *)p_rx_pd;
 132         }
 133
 134         /* Chop off the leading header bytes so the skb points to the start of
 135          *   either the reconstructed EthII frame or the 802.2/llc/snap frame
 136          */
 137         skb_pull(skb, hdrchop);
 138
 139         priv->cur_rate = lbs_fw_index_to_data_rate(p_rx_pd->rx_rate);
 140
 141         lbs_deb_rx("rx data: size of actual packet %d\n", skb->len);
 142         dev->stats.rx_bytes += skb->len;
 143         dev->stats.rx_packets++;
 144
 145         skb->protocol = eth_type_trans(skb, dev);
 146         if (in_interrupt())
 147                 netif_rx(skb);
 148         else
 149                 netif_rx_ni(skb);
 150
 151         ret = 0;
 152 done:
 153         lbs_deb_leave_args(LBS_DEB_RX, "ret %d", ret);
 154         return ret;
 155 }
 156 EXPORT_SYMBOL_GPL(lbs_process_rxed_packet);
 157
 158 /**
 159  *  @brief This function converts Tx/Rx rates from the Marvell WLAN format
 160  *  (see Table 2 in Section 3.1) to IEEE80211_RADIOTAP_RATE units (500 Kb/s)
 161  *
 162  *  @param      rate    Input rate
 163  *  @return     Output Rate (0 if invalid)
 164  */
 165 static u8 convert_mv_rate_to_radiotap(u8 rate)
 166 {
 167         switch (rate) {
 168         case 0:         /*   1 Mbps */
 169                 return 2;
 170         case 1:         /*   2 Mbps */
 171                 return 4;
 172         case 2:         /* 5.5 Mbps */
 173                 return 11;
 174         case 3:         /*  11 Mbps */
 175                 return 22;
 176         /* case 4: reserved */
 177         case 5:         /*   6 Mbps */
 178                 return 12;
 179         case 6:         /*   9 Mbps */
 180                 return 18;
 181         case 7:         /*  12 Mbps */
 182                 return 24;
 183         case 8:         /*  18 Mbps */
 184                 return 36;
 185         case 9:         /*  24 Mbps */
 186                 return 48;
 187         case 10:                /*  36 Mbps */
 188                 return 72;
 189         case 11:                /*  48 Mbps */
 190                 return 96;
 191         case 12:                /*  54 Mbps */
 192                 return 108;
 193         }
 194         lbs_pr_alert("Invalid Marvell WLAN rate %i\n", rate);
 195         return 0;
 196 }
 197
 198 /**
 199  *  @brief This function processes a received 802.11 packet and forwards it
 200  *  to kernel/upper layer
 201  *
 202  *  @param      priv    A pointer to struct lbs_private
 203  *  @param      skb             A pointer to skb which includes the received packet
 204  *  @return     0 or -1
 205  */
 206 static int process_rxed_802_11_packet(struct lbs_private *priv,
 207         struct sk_buff *skb)
 208 {
 209         int ret = 0;
 210         struct net_device *dev = priv->dev;
 211         struct rx80211packethdr *p_rx_pkt;
 212         struct rxpd *prxpd;
 213         struct rx_radiotap_hdr radiotap_hdr;
 214         struct rx_radiotap_hdr *pradiotap_hdr;
 215
 216         lbs_deb_enter(LBS_DEB_RX);
 217
 218         p_rx_pkt = (struct rx80211packethdr *) skb->data;
 219         prxpd = &p_rx_pkt->rx_pd;
 220
 221         /* lbs_deb_hex(LBS_DEB_RX, "RX Data: Before chop rxpd", skb->data, min(skb->len, 100)); */
 222
 223         if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) {
 224                 lbs_deb_rx("rx err: frame received with bad length\n");
 225                 dev->stats.rx_length_errors++;
 226                 ret = -EINVAL;
 227                 kfree_skb(skb);
 228                 goto done;
 229         }
 230
 231         lbs_deb_rx("rx data: skb->len-sizeof(RxPd) = %d-%zd = %zd\n",
 232                skb->len, sizeof(struct rxpd), skb->len - sizeof(struct rxpd));
 233
 234         /* create the exported radio header */
 235
 236         /* radiotap header */
 237         memset(&radiotap_hdr, 0, sizeof(radiotap_hdr));
 238         /* XXX must check radiotap_hdr.hdr.it_pad for pad */
 239         radiotap_hdr.hdr.it_len = cpu_to_le16 (sizeof(struct rx_radiotap_hdr));
 240         radiotap_hdr.hdr.it_present = cpu_to_le32 (RX_RADIOTAP_PRESENT);
 241         radiotap_hdr.rate = convert_mv_rate_to_radiotap(prxpd->rx_rate);
 242         /* XXX must check no carryout */
 243         radiotap_hdr.antsignal = prxpd->snr + prxpd->nf;
 244
 245         /* chop the rxpd */
 246         skb_pull(skb, sizeof(struct rxpd));
 247
 248         /* add space for the new radio header */
 249         if ((skb_headroom(skb) < sizeof(struct rx_radiotap_hdr)) &&
 250             pskb_expand_head(skb, sizeof(struct rx_radiotap_hdr), 0, GFP_ATOMIC)) {
 251                 lbs_pr_alert("%s: couldn't pskb_expand_head\n", __func__);
 252                 ret = -ENOMEM;
 253                 kfree_skb(skb);
 254                 goto done;
 255         }
 256
 257         pradiotap_hdr = (void *)skb_push(skb, sizeof(struct rx_radiotap_hdr));
 258         memcpy(pradiotap_hdr, &radiotap_hdr, sizeof(struct rx_radiotap_hdr));
 259
 260         priv->cur_rate = lbs_fw_index_to_data_rate(prxpd->rx_rate);
 261
 262         lbs_deb_rx("rx data: size of actual packet %d\n", skb->len);
 263         dev->stats.rx_bytes += skb->len;
 264         dev->stats.rx_packets++;
 265
 266         skb->protocol = eth_type_trans(skb, priv->dev);
 267
 268         if (in_interrupt())
 269                 netif_rx(skb);
 270         else
 271                 netif_rx_ni(skb);
 272
 273         ret = 0;
 274
 275 done:
 276         lbs_deb_leave_args(LBS_DEB_RX, "ret %d", ret);
 277         return ret;
 278 }