drivers/net/wireless/libertas/rx.c

   1 /*
   2  * This file contains the handling of RX in wlan driver.
   3  */
   4
   5 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   6
   7 #include <linux/etherdevice.h>
   8 #include <linux/hardirq.h>
   9 #include <linux/slab.h>
  10 #include <linux/types.h>
  11 #include <net/cfg80211.h>
  12
  13 #include "defs.h"
  14 #include "host.h"
  15 #include "radiotap.h"
  16 #include "decl.h"
  17 #include "dev.h"
  18 #include "mesh.h"
  19
  20 struct eth803hdr {
  21         u8 dest_addr[6];
  22         u8 src_addr[6];
  23         u16 h803_len;
  24 } __packed;
  25
  26 struct rfc1042hdr {
  27         u8 llc_dsap;
  28         u8 llc_ssap;
  29         u8 llc_ctrl;
  30         u8 snap_oui[3];
  31         u16 snap_type;
  32 } __packed;
  33
  34 struct rxpackethdr {
  35         struct eth803hdr eth803_hdr;
  36         struct rfc1042hdr rfc1042_hdr;
  37 } __packed;
  38
  39 struct rx80211packethdr {
  40         struct rxpd rx_pd;
  41         void *eth80211_hdr;
  42 } __packed;
  43
  44 static int process_rxed_802_11_packet(struct lbs_private *priv,
  45         struct sk_buff *skb);
  46
  47 /**
  48  * lbs_process_rxed_packet - processes received packet and forwards it
  49  * to kernel/upper layer
  50  *
  51  * @priv:       A pointer to &struct lbs_private
  52  * @skb:        A pointer to skb which includes the received packet
  53  * returns:     0 or -1
  54  */
  55 int lbs_process_rxed_packet(struct lbs_private *priv, struct sk_buff *skb)
  56 {
  57         int ret = 0;
  58         struct net_device *dev = priv->dev;
  59         struct rxpackethdr *p_rx_pkt;
  60         struct rxpd *p_rx_pd;
  61         int hdrchop;
  62         struct ethhdr *p_ethhdr;
  63         static const u8 rfc1042_eth_hdr[] = {
  64                 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00
  65         };
  66
  67         lbs_deb_enter(LBS_DEB_RX);
  68
  69         BUG_ON(!skb);
  70
  71         skb->ip_summed = CHECKSUM_NONE;
  72
  73         if (priv->wdev->iftype == NL80211_IFTYPE_MONITOR)
  74                 return process_rxed_802_11_packet(priv, skb);
  75
  76         p_rx_pd = (struct rxpd *) skb->data;
  77         p_rx_pkt = (struct rxpackethdr *) ((u8 *)p_rx_pd +
  78                 le32_to_cpu(p_rx_pd->pkt_ptr));
  79
  80         dev = lbs_mesh_set_dev(priv, dev, p_rx_pd);
  81
  82         lbs_deb_hex(LBS_DEB_RX, "RX Data: Before chop rxpd", skb->data,
  83                  min_t(unsigned int, skb->len, 100));
  84
  85         if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) {
  86                 lbs_deb_rx("rx err: frame received with bad length\n");
  87                 dev->stats.rx_length_errors++;
  88                 ret = 0;
  89                 dev_kfree_skb(skb);
  90                 goto done;
  91         }
  92
  93         lbs_deb_rx("rx data: skb->len - pkt_ptr = %d-%zd = %zd\n",
  94                 skb->len, (size_t)le32_to_cpu(p_rx_pd->pkt_ptr),
  95                 skb->len - (size_t)le32_to_cpu(p_rx_pd->pkt_ptr));
  96
  97         lbs_deb_hex(LBS_DEB_RX, "RX Data: Dest", p_rx_pkt->eth803_hdr.dest_addr,
  98                 sizeof(p_rx_pkt->eth803_hdr.dest_addr));
  99         lbs_deb_hex(LBS_DEB_RX, "RX Data: Src", p_rx_pkt->eth803_hdr.src_addr,
 100                 sizeof(p_rx_pkt->eth803_hdr.src_addr));
 101
 102         if (memcmp(&p_rx_pkt->rfc1042_hdr,
 103                    rfc1042_eth_hdr, sizeof(rfc1042_eth_hdr)) == 0) {
 104                 /*
 105                  *  Replace the 803 header and rfc1042 header (llc/snap) with an
 106                  *    EthernetII header, keep the src/dst and snap_type (ethertype)
 107                  *
 108                  *  The firmware only passes up SNAP frames converting
 109                  *    all RX Data from 802.11 to 802.2/LLC/SNAP frames.
 110                  *
 111                  *  To create the Ethernet II, just move the src, dst address right
 112                  *    before the snap_type.
 113                  */
 114                 p_ethhdr = (struct ethhdr *)
 115                     ((u8 *) &p_rx_pkt->eth803_hdr
 116                      + sizeof(p_rx_pkt->eth803_hdr) + sizeof(p_rx_pkt->rfc1042_hdr)
 117                      - sizeof(p_rx_pkt->eth803_hdr.dest_addr)
 118                      - sizeof(p_rx_pkt->eth803_hdr.src_addr)
 119                      - sizeof(p_rx_pkt->rfc1042_hdr.snap_type));
 120
 121                 memcpy(p_ethhdr->h_source, p_rx_pkt->eth803_hdr.src_addr,
 122                        sizeof(p_ethhdr->h_source));
 123                 memcpy(p_ethhdr->h_dest, p_rx_pkt->eth803_hdr.dest_addr,
 124                        sizeof(p_ethhdr->h_dest));
 125
 126                 /* Chop off the rxpd + the excess memory from the 802.2/llc/snap header
 127                  *   that was removed
 128                  */
 129                 hdrchop = (u8 *)p_ethhdr - (u8 *)p_rx_pd;
 130         } else {
 131                 lbs_deb_hex(LBS_DEB_RX, "RX Data: LLC/SNAP",
 132                         (u8 *) &p_rx_pkt->rfc1042_hdr,
 133                         sizeof(p_rx_pkt->rfc1042_hdr));
 134
 135                 /* Chop off the rxpd */
 136                 hdrchop = (u8 *)&p_rx_pkt->eth803_hdr - (u8 *)p_rx_pd;
 137         }
 138
 139         /* Chop off the leading header bytes so the skb points to the start of
 140          *   either the reconstructed EthII frame or the 802.2/llc/snap frame
 141          */
 142         skb_pull(skb, hdrchop);
 143
 144         priv->cur_rate = lbs_fw_index_to_data_rate(p_rx_pd->rx_rate);
 145
 146         lbs_deb_rx("rx data: size of actual packet %d\n", skb->len);
 147         dev->stats.rx_bytes += skb->len;
 148         dev->stats.rx_packets++;
 149
 150         skb->protocol = eth_type_trans(skb, dev);
 151         if (in_interrupt())
 152                 netif_rx(skb);
 153         else
 154                 netif_rx_ni(skb);
 155
 156         ret = 0;
 157 done:
 158         lbs_deb_leave_args(LBS_DEB_RX, "ret %d", ret);
 159         return ret;
 160 }
 161 EXPORT_SYMBOL_GPL(lbs_process_rxed_packet);
 162
 163 /**
 164  * convert_mv_rate_to_radiotap - converts Tx/Rx rates from Marvell WLAN format
 165  * (see Table 2 in Section 3.1) to IEEE80211_RADIOTAP_RATE units (500 Kb/s)
 166  *
 167  * @rate:       Input rate
 168  * returns:     Output Rate (0 if invalid)
 169  */
 170 static u8 convert_mv_rate_to_radiotap(u8 rate)
 171 {
 172         switch (rate) {
 173         case 0:         /*   1 Mbps */
 174                 return 2;
 175         case 1:         /*   2 Mbps */
 176                 return 4;
 177         case 2:         /* 5.5 Mbps */
 178                 return 11;
 179         case 3:         /*  11 Mbps */
 180                 return 22;
 181         /* case 4: reserved */
 182         case 5:         /*   6 Mbps */
 183                 return 12;
 184         case 6:         /*   9 Mbps */
 185                 return 18;
 186         case 7:         /*  12 Mbps */
 187                 return 24;
 188         case 8:         /*  18 Mbps */
 189                 return 36;
 190         case 9:         /*  24 Mbps */
 191                 return 48;
 192         case 10:                /*  36 Mbps */
 193                 return 72;
 194         case 11:                /*  48 Mbps */
 195                 return 96;
 196         case 12:                /*  54 Mbps */
 197                 return 108;
 198         }
 199         pr_alert("Invalid Marvell WLAN rate %i\n", rate);
 200         return 0;
 201 }
 202
 203 /**
 204  * process_rxed_802_11_packet - processes a received 802.11 packet and forwards
 205  * it to kernel/upper layer
 206  *
 207  * @priv:       A pointer to &struct lbs_private
 208  * @skb:        A pointer to skb which includes the received packet
 209  * returns:     0 or -1
 210  */
 211 static int process_rxed_802_11_packet(struct lbs_private *priv,
 212         struct sk_buff *skb)
 213 {
 214         int ret = 0;
 215         struct net_device *dev = priv->dev;
 216         struct rx80211packethdr *p_rx_pkt;
 217         struct rxpd *prxpd;
 218         struct rx_radiotap_hdr radiotap_hdr;
 219         struct rx_radiotap_hdr *pradiotap_hdr;
 220
 221         lbs_deb_enter(LBS_DEB_RX);
 222
 223         p_rx_pkt = (struct rx80211packethdr *) skb->data;
 224         prxpd = &p_rx_pkt->rx_pd;
 225
 226         /* lbs_deb_hex(LBS_DEB_RX, "RX Data: Before chop rxpd", skb->data, min(skb->len, 100)); */
 227
 228         if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) {
 229                 lbs_deb_rx("rx err: frame received with bad length\n");
 230                 dev->stats.rx_length_errors++;
 231                 ret = -EINVAL;
 232                 kfree_skb(skb);
 233                 goto done;
 234         }
 235
 236         lbs_deb_rx("rx data: skb->len-sizeof(RxPd) = %d-%zd = %zd\n",
 237                skb->len, sizeof(struct rxpd), skb->len - sizeof(struct rxpd));
 238
 239         /* create the exported radio header */
 240
 241         /* radiotap header */
 242         memset(&radiotap_hdr, 0, sizeof(radiotap_hdr));
 243         /* XXX must check radiotap_hdr.hdr.it_pad for pad */
 244         radiotap_hdr.hdr.it_len = cpu_to_le16 (sizeof(struct rx_radiotap_hdr));
 245         radiotap_hdr.hdr.it_present = cpu_to_le32 (RX_RADIOTAP_PRESENT);
 246         radiotap_hdr.rate = convert_mv_rate_to_radiotap(prxpd->rx_rate);
 247         /* XXX must check no carryout */
 248         radiotap_hdr.antsignal = prxpd->snr + prxpd->nf;
 249
 250         /* chop the rxpd */
 251         skb_pull(skb, sizeof(struct rxpd));
 252
 253         /* add space for the new radio header */
 254         if ((skb_headroom(skb) < sizeof(struct rx_radiotap_hdr)) &&
 255             pskb_expand_head(skb, sizeof(struct rx_radiotap_hdr), 0, GFP_ATOMIC)) {
 256                 netdev_alert(dev, "%s: couldn't pskb_expand_head\n", __func__);
 257                 ret = -ENOMEM;
 258                 kfree_skb(skb);
 259                 goto done;
 260         }
 261
 262         pradiotap_hdr = (void *)skb_push(skb, sizeof(struct rx_radiotap_hdr));
 263         memcpy(pradiotap_hdr, &radiotap_hdr, sizeof(struct rx_radiotap_hdr));
 264
 265         priv->cur_rate = lbs_fw_index_to_data_rate(prxpd->rx_rate);
 266
 267         lbs_deb_rx("rx data: size of actual packet %d\n", skb->len);
 268         dev->stats.rx_bytes += skb->len;
 269         dev->stats.rx_packets++;
 270
 271         skb->protocol = eth_type_trans(skb, priv->dev);
 272
 273         if (in_interrupt())
 274                 netif_rx(skb);
 275         else
 276                 netif_rx_ni(skb);
 277
 278         ret = 0;
 279
 280 done:
 281         lbs_deb_leave_args(LBS_DEB_RX, "ret %d", ret);
 282         return ret;
 283 }