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