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/types.h>
   6
   7 #include "hostcmd.h"
   8 #include "radiotap.h"
   9 #include "decl.h"
  10 #include "dev.h"
  11 #include "wext.h"
  12
  13 struct eth803hdr {
  14         u8 dest_addr[6];
  15         u8 src_addr[6];
  16         u16 h803_len;
  17 } __attribute__ ((packed));
  18
  19 struct rfc1042hdr {
  20         u8 llc_dsap;
  21         u8 llc_ssap;
  22         u8 llc_ctrl;
  23         u8 snap_oui[3];
  24         u16 snap_type;
  25 } __attribute__ ((packed));
  26
  27 struct rxpackethdr {
  28         struct rxpd rx_pd;
  29         struct eth803hdr eth803_hdr;
  30         struct rfc1042hdr rfc1042_hdr;
  31 } __attribute__ ((packed));
  32
  33 struct rx80211packethdr {
  34         struct rxpd rx_pd;
  35         void *eth80211_hdr;
  36 } __attribute__ ((packed));
  37
  38 static int process_rxed_802_11_packet(struct lbs_private *priv,
  39         struct sk_buff *skb);
  40
  41 /**
  42  *  @brief This function computes the avgSNR .
  43  *
  44  *  @param priv    A pointer to struct lbs_private structure
  45  *  @return        avgSNR
  46  */
  47 static u8 lbs_getavgsnr(struct lbs_private *priv)
  48 {
  49         u8 i;
  50         u16 temp = 0;
  51         if (priv->numSNRNF == 0)
  52                 return 0;
  53         for (i = 0; i < priv->numSNRNF; i++)
  54                 temp += priv->rawSNR[i];
  55         return (u8) (temp / priv->numSNRNF);
  56
  57 }
  58
  59 /**
  60  *  @brief This function computes the AvgNF
  61  *
  62  *  @param priv    A pointer to struct lbs_private structure
  63  *  @return        AvgNF
  64  */
  65 static u8 lbs_getavgnf(struct lbs_private *priv)
  66 {
  67         u8 i;
  68         u16 temp = 0;
  69         if (priv->numSNRNF == 0)
  70                 return 0;
  71         for (i = 0; i < priv->numSNRNF; i++)
  72                 temp += priv->rawNF[i];
  73         return (u8) (temp / priv->numSNRNF);
  74
  75 }
  76
  77 /**
  78  *  @brief This function save the raw SNR/NF to our internel buffer
  79  *
  80  *  @param priv    A pointer to struct lbs_private structure
  81  *  @param prxpd   A pointer to rxpd structure of received packet
  82  *  @return        n/a
  83  */
  84 static void lbs_save_rawSNRNF(struct lbs_private *priv, struct rxpd *p_rx_pd)
  85 {
  86         if (priv->numSNRNF < DEFAULT_DATA_AVG_FACTOR)
  87                 priv->numSNRNF++;
  88         priv->rawSNR[priv->nextSNRNF] = p_rx_pd->snr;
  89         priv->rawNF[priv->nextSNRNF] = p_rx_pd->nf;
  90         priv->nextSNRNF++;
  91         if (priv->nextSNRNF >= DEFAULT_DATA_AVG_FACTOR)
  92                 priv->nextSNRNF = 0;
  93         return;
  94 }
  95
  96 /**
  97  *  @brief This function computes the RSSI in received packet.
  98  *
  99  *  @param priv    A pointer to struct lbs_private structure
 100  *  @param prxpd   A pointer to rxpd structure of received packet
 101  *  @return        n/a
 102  */
 103 static void lbs_compute_rssi(struct lbs_private *priv, struct rxpd *p_rx_pd)
 104 {
 105
 106         lbs_deb_enter(LBS_DEB_RX);
 107
 108         lbs_deb_rx("rxpd: SNR %d, NF %d\n", p_rx_pd->snr, p_rx_pd->nf);
 109         lbs_deb_rx("before computing SNR: SNR-avg = %d, NF-avg = %d\n",
 110                priv->SNR[TYPE_RXPD][TYPE_AVG] / AVG_SCALE,
 111                priv->NF[TYPE_RXPD][TYPE_AVG] / AVG_SCALE);
 112
 113         priv->SNR[TYPE_RXPD][TYPE_NOAVG] = p_rx_pd->snr;
 114         priv->NF[TYPE_RXPD][TYPE_NOAVG] = p_rx_pd->nf;
 115         lbs_save_rawSNRNF(priv, p_rx_pd);
 116
 117         priv->SNR[TYPE_RXPD][TYPE_AVG] = lbs_getavgsnr(priv) * AVG_SCALE;
 118         priv->NF[TYPE_RXPD][TYPE_AVG] = lbs_getavgnf(priv) * AVG_SCALE;
 119         lbs_deb_rx("after computing SNR: SNR-avg = %d, NF-avg = %d\n",
 120                priv->SNR[TYPE_RXPD][TYPE_AVG] / AVG_SCALE,
 121                priv->NF[TYPE_RXPD][TYPE_AVG] / AVG_SCALE);
 122
 123         priv->RSSI[TYPE_RXPD][TYPE_NOAVG] =
 124             CAL_RSSI(priv->SNR[TYPE_RXPD][TYPE_NOAVG],
 125                      priv->NF[TYPE_RXPD][TYPE_NOAVG]);
 126
 127         priv->RSSI[TYPE_RXPD][TYPE_AVG] =
 128             CAL_RSSI(priv->SNR[TYPE_RXPD][TYPE_AVG] / AVG_SCALE,
 129                      priv->NF[TYPE_RXPD][TYPE_AVG] / AVG_SCALE);
 130
 131         lbs_deb_leave(LBS_DEB_RX);
 132 }
 133
 134 /**
 135  *  @brief This function processes received packet and forwards it
 136  *  to kernel/upper layer
 137  *
 138  *  @param priv    A pointer to struct lbs_private
 139  *  @param skb     A pointer to skb which includes the received packet
 140  *  @return        0 or -1
 141  */
 142 int lbs_process_rxed_packet(struct lbs_private *priv, struct sk_buff *skb)
 143 {
 144         int ret = 0;
 145         struct net_device *dev = priv->dev;
 146         struct rxpackethdr *p_rx_pkt;
 147         struct rxpd *p_rx_pd;
 148         int hdrchop;
 149         struct ethhdr *p_ethhdr;
 150         const u8 rfc1042_eth_hdr[] = { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };
 151
 152         lbs_deb_enter(LBS_DEB_RX);
 153
 154         BUG_ON(!skb);
 155
 156         skb->ip_summed = CHECKSUM_NONE;
 157
 158         if (priv->monitormode)
 159                 return process_rxed_802_11_packet(priv, skb);
 160
 161         p_rx_pkt = (struct rxpackethdr *) skb->data;
 162         p_rx_pd = &p_rx_pkt->rx_pd;
 163         if (priv->mesh_dev) {
 164                 if (priv->mesh_fw_ver == MESH_FW_OLD) {
 165                         if (p_rx_pd->rx_control & RxPD_MESH_FRAME)
 166                                 dev = priv->mesh_dev;
 167                 } else if (priv->mesh_fw_ver == MESH_FW_NEW) {
 168                         if (p_rx_pd->u.bss.bss_num == MESH_IFACE_ID)
 169                                 dev = priv->mesh_dev;
 170                 }
 171         }
 172
 173         lbs_deb_hex(LBS_DEB_RX, "RX Data: Before chop rxpd", skb->data,
 174                  min_t(unsigned int, skb->len, 100));
 175
 176         if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) {
 177                 lbs_deb_rx("rx err: frame received with bad length\n");
 178                 dev->stats.rx_length_errors++;
 179                 ret = 0;
 180                 dev_kfree_skb(skb);
 181                 goto done;
 182         }
 183
 184         lbs_deb_rx("rx data: skb->len-sizeof(RxPd) = %d-%zd = %zd\n",
 185                skb->len, sizeof(struct rxpd), skb->len - sizeof(struct rxpd));
 186
 187         lbs_deb_hex(LBS_DEB_RX, "RX Data: Dest", p_rx_pkt->eth803_hdr.dest_addr,
 188                 sizeof(p_rx_pkt->eth803_hdr.dest_addr));
 189         lbs_deb_hex(LBS_DEB_RX, "RX Data: Src", p_rx_pkt->eth803_hdr.src_addr,
 190                 sizeof(p_rx_pkt->eth803_hdr.src_addr));
 191
 192         if (memcmp(&p_rx_pkt->rfc1042_hdr,
 193                    rfc1042_eth_hdr, sizeof(rfc1042_eth_hdr)) == 0) {
 194                 /*
 195                  *  Replace the 803 header and rfc1042 header (llc/snap) with an
 196                  *    EthernetII header, keep the src/dst and snap_type (ethertype)
 197                  *
 198                  *  The firmware only passes up SNAP frames converting
 199                  *    all RX Data from 802.11 to 802.2/LLC/SNAP frames.
 200                  *
 201                  *  To create the Ethernet II, just move the src, dst address right
 202                  *    before the snap_type.
 203                  */
 204                 p_ethhdr = (struct ethhdr *)
 205                     ((u8 *) & p_rx_pkt->eth803_hdr
 206                      + sizeof(p_rx_pkt->eth803_hdr) + sizeof(p_rx_pkt->rfc1042_hdr)
 207                      - sizeof(p_rx_pkt->eth803_hdr.dest_addr)
 208                      - sizeof(p_rx_pkt->eth803_hdr.src_addr)
 209                      - sizeof(p_rx_pkt->rfc1042_hdr.snap_type));
 210
 211                 memcpy(p_ethhdr->h_source, p_rx_pkt->eth803_hdr.src_addr,
 212                        sizeof(p_ethhdr->h_source));
 213                 memcpy(p_ethhdr->h_dest, p_rx_pkt->eth803_hdr.dest_addr,
 214                        sizeof(p_ethhdr->h_dest));
 215
 216                 /* Chop off the rxpd + the excess memory from the 802.2/llc/snap header
 217                  *   that was removed
 218                  */
 219                 hdrchop = (u8 *) p_ethhdr - (u8 *) p_rx_pkt;
 220         } else {
 221                 lbs_deb_hex(LBS_DEB_RX, "RX Data: LLC/SNAP",
 222                         (u8 *) & p_rx_pkt->rfc1042_hdr,
 223                         sizeof(p_rx_pkt->rfc1042_hdr));
 224
 225                 /* Chop off the rxpd */
 226                 hdrchop = (u8 *) & p_rx_pkt->eth803_hdr - (u8 *) p_rx_pkt;
 227         }
 228
 229         /* Chop off the leading header bytes so the skb points to the start of
 230          *   either the reconstructed EthII frame or the 802.2/llc/snap frame
 231          */
 232         skb_pull(skb, hdrchop);
 233
 234         /* Take the data rate from the rxpd structure
 235          * only if the rate is auto
 236          */
 237         if (priv->enablehwauto)
 238                 priv->cur_rate = lbs_fw_index_to_data_rate(p_rx_pd->rx_rate);
 239
 240         lbs_compute_rssi(priv, p_rx_pd);
 241
 242         lbs_deb_rx("rx data: size of actual packet %d\n", skb->len);
 243         dev->stats.rx_bytes += skb->len;
 244         dev->stats.rx_packets++;
 245
 246         skb->protocol = eth_type_trans(skb, dev);
 247         if (in_interrupt())
 248                 netif_rx(skb);
 249         else
 250                 netif_rx_ni(skb);
 251
 252         ret = 0;
 253 done:
 254         lbs_deb_leave_args(LBS_DEB_RX, "ret %d", ret);
 255         return ret;
 256 }
 257 EXPORT_SYMBOL_GPL(lbs_process_rxed_packet);
 258
 259 /**
 260  *  @brief This function converts Tx/Rx rates from the Marvell WLAN format
 261  *  (see Table 2 in Section 3.1) to IEEE80211_RADIOTAP_RATE units (500 Kb/s)
 262  *
 263  *  @param rate    Input rate
 264  *  @return        Output Rate (0 if invalid)
 265  */
 266 static u8 convert_mv_rate_to_radiotap(u8 rate)
 267 {
 268         switch (rate) {
 269         case 0:         /*   1 Mbps */
 270                 return 2;
 271         case 1:         /*   2 Mbps */
 272                 return 4;
 273         case 2:         /* 5.5 Mbps */
 274                 return 11;
 275         case 3:         /*  11 Mbps */
 276                 return 22;
 277         /* case 4: reserved */
 278         case 5:         /*   6 Mbps */
 279                 return 12;
 280         case 6:         /*   9 Mbps */
 281                 return 18;
 282         case 7:         /*  12 Mbps */
 283                 return 24;
 284         case 8:         /*  18 Mbps */
 285                 return 36;
 286         case 9:         /*  24 Mbps */
 287                 return 48;
 288         case 10:                /*  36 Mbps */
 289                 return 72;
 290         case 11:                /*  48 Mbps */
 291                 return 96;
 292         case 12:                /*  54 Mbps */
 293                 return 108;
 294         }
 295         lbs_pr_alert("Invalid Marvell WLAN rate %i\n", rate);
 296         return 0;
 297 }
 298
 299 /**
 300  *  @brief This function processes a received 802.11 packet and forwards it
 301  *  to kernel/upper layer
 302  *
 303  *  @param priv    A pointer to struct lbs_private
 304  *  @param skb     A pointer to skb which includes the received packet
 305  *  @return        0 or -1
 306  */
 307 static int process_rxed_802_11_packet(struct lbs_private *priv,
 308         struct sk_buff *skb)
 309 {
 310         int ret = 0;
 311         struct net_device *dev = priv->dev;
 312         struct rx80211packethdr *p_rx_pkt;
 313         struct rxpd *prxpd;
 314         struct rx_radiotap_hdr radiotap_hdr;
 315         struct rx_radiotap_hdr *pradiotap_hdr;
 316
 317         lbs_deb_enter(LBS_DEB_RX);
 318
 319         p_rx_pkt = (struct rx80211packethdr *) skb->data;
 320         prxpd = &p_rx_pkt->rx_pd;
 321
 322         // lbs_deb_hex(LBS_DEB_RX, "RX Data: Before chop rxpd", skb->data, min(skb->len, 100));
 323
 324         if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) {
 325                 lbs_deb_rx("rx err: frame received with bad length\n");
 326                 dev->stats.rx_length_errors++;
 327                 ret = -EINVAL;
 328                 kfree_skb(skb);
 329                 goto done;
 330         }
 331
 332         lbs_deb_rx("rx data: skb->len-sizeof(RxPd) = %d-%zd = %zd\n",
 333                skb->len, sizeof(struct rxpd), skb->len - sizeof(struct rxpd));
 334
 335         /* create the exported radio header */
 336
 337         /* radiotap header */
 338         radiotap_hdr.hdr.it_version = 0;
 339         /* XXX must check this value for pad */
 340         radiotap_hdr.hdr.it_pad = 0;
 341         radiotap_hdr.hdr.it_len = cpu_to_le16 (sizeof(struct rx_radiotap_hdr));
 342         radiotap_hdr.hdr.it_present = cpu_to_le32 (RX_RADIOTAP_PRESENT);
 343         radiotap_hdr.rate = convert_mv_rate_to_radiotap(prxpd->rx_rate);
 344         /* XXX must check no carryout */
 345         radiotap_hdr.antsignal = prxpd->snr + prxpd->nf;
 346
 347         /* chop the rxpd */
 348         skb_pull(skb, sizeof(struct rxpd));
 349
 350         /* add space for the new radio header */
 351         if ((skb_headroom(skb) < sizeof(struct rx_radiotap_hdr)) &&
 352             pskb_expand_head(skb, sizeof(struct rx_radiotap_hdr), 0, GFP_ATOMIC)) {
 353                 lbs_pr_alert("%s: couldn't pskb_expand_head\n", __func__);
 354                 ret = -ENOMEM;
 355                 kfree_skb(skb);
 356                 goto done;
 357         }
 358
 359         pradiotap_hdr = (void *)skb_push(skb, sizeof(struct rx_radiotap_hdr));
 360         memcpy(pradiotap_hdr, &radiotap_hdr, sizeof(struct rx_radiotap_hdr));
 361
 362         /* Take the data rate from the rxpd structure
 363          * only if the rate is auto
 364          */
 365         if (priv->enablehwauto)
 366                 priv->cur_rate = lbs_fw_index_to_data_rate(prxpd->rx_rate);
 367
 368         lbs_compute_rssi(priv, prxpd);
 369
 370         lbs_deb_rx("rx data: size of actual packet %d\n", skb->len);
 371         dev->stats.rx_bytes += skb->len;
 372         dev->stats.rx_packets++;
 373
 374         skb->protocol = eth_type_trans(skb, priv->rtap_net_dev);
 375         netif_rx(skb);
 376
 377         ret = 0;
 378
 379 done:
 380         lbs_deb_leave_args(LBS_DEB_RX, "ret %d", ret);
 381         return ret;
 382 }