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