err.no Git - linux-2.6/blob - 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         struct lbs_adapter *adapter = priv->adapter;
  52         if (adapter->numSNRNF == 0)
  53                 return 0;
  54         for (i = 0; i < adapter->numSNRNF; i++)
  55                 temp += adapter->rawSNR[i];
  56         return (u8) (temp / adapter->numSNRNF);
  57
  58 }
  59
  60 /**
  61  *  @brief This function computes the AvgNF
  62  *
  63  *  @param priv    A pointer to struct lbs_private structure
  64  *  @return        AvgNF
  65  */
  66 static u8 lbs_getavgnf(struct lbs_private *priv)
  67 {
  68         u8 i;
  69         u16 temp = 0;
  70         struct lbs_adapter *adapter = priv->adapter;
  71         if (adapter->numSNRNF == 0)
  72                 return 0;
  73         for (i = 0; i < adapter->numSNRNF; i++)
  74                 temp += adapter->rawNF[i];
  75         return (u8) (temp / adapter->numSNRNF);
  76
  77 }
  78
  79 /**
  80  *  @brief This function save the raw SNR/NF to our internel buffer
  81  *
  82  *  @param priv    A pointer to struct lbs_private structure
  83  *  @param prxpd   A pointer to rxpd structure of received packet
  84  *  @return        n/a
  85  */
  86 static void lbs_save_rawSNRNF(struct lbs_private *priv, struct rxpd *p_rx_pd)
  87 {
  88         struct lbs_adapter *adapter = priv->adapter;
  89         if (adapter->numSNRNF < DEFAULT_DATA_AVG_FACTOR)
  90                 adapter->numSNRNF++;
  91         adapter->rawSNR[adapter->nextSNRNF] = p_rx_pd->snr;
  92         adapter->rawNF[adapter->nextSNRNF] = p_rx_pd->nf;
  93         adapter->nextSNRNF++;
  94         if (adapter->nextSNRNF >= DEFAULT_DATA_AVG_FACTOR)
  95                 adapter->nextSNRNF = 0;
  96         return;
  97 }
  98
  99 /**
 100  *  @brief This function computes the RSSI in received packet.
 101  *
 102  *  @param priv    A pointer to struct lbs_private structure
 103  *  @param prxpd   A pointer to rxpd structure of received packet
 104  *  @return        n/a
 105  */
 106 static void lbs_compute_rssi(struct lbs_private *priv, struct rxpd *p_rx_pd)
 107 {
 108         struct lbs_adapter *adapter = priv->adapter;
 109
 110         lbs_deb_enter(LBS_DEB_RX);
 111
 112         lbs_deb_rx("rxpd: SNR %d, NF %d\n", p_rx_pd->snr, p_rx_pd->nf);
 113         lbs_deb_rx("before computing SNR: SNR-avg = %d, NF-avg = %d\n",
 114                adapter->SNR[TYPE_RXPD][TYPE_AVG] / AVG_SCALE,
 115                adapter->NF[TYPE_RXPD][TYPE_AVG] / AVG_SCALE);
 116
 117         adapter->SNR[TYPE_RXPD][TYPE_NOAVG] = p_rx_pd->snr;
 118         adapter->NF[TYPE_RXPD][TYPE_NOAVG] = p_rx_pd->nf;
 119         lbs_save_rawSNRNF(priv, p_rx_pd);
 120
 121         adapter->SNR[TYPE_RXPD][TYPE_AVG] = lbs_getavgsnr(priv) * AVG_SCALE;
 122         adapter->NF[TYPE_RXPD][TYPE_AVG] = lbs_getavgnf(priv) * AVG_SCALE;
 123         lbs_deb_rx("after computing SNR: SNR-avg = %d, NF-avg = %d\n",
 124                adapter->SNR[TYPE_RXPD][TYPE_AVG] / AVG_SCALE,
 125                adapter->NF[TYPE_RXPD][TYPE_AVG] / AVG_SCALE);
 126
 127         adapter->RSSI[TYPE_RXPD][TYPE_NOAVG] =
 128             CAL_RSSI(adapter->SNR[TYPE_RXPD][TYPE_NOAVG],
 129                      adapter->NF[TYPE_RXPD][TYPE_NOAVG]);
 130
 131         adapter->RSSI[TYPE_RXPD][TYPE_AVG] =
 132             CAL_RSSI(adapter->SNR[TYPE_RXPD][TYPE_AVG] / AVG_SCALE,
 133                      adapter->NF[TYPE_RXPD][TYPE_AVG] / AVG_SCALE);
 134
 135         lbs_deb_leave(LBS_DEB_RX);
 136 }
 137
 138 void lbs_upload_rx_packet(struct lbs_private *priv, struct sk_buff *skb)
 139 {
 140         lbs_deb_rx("skb->data %p\n", skb->data);
 141
 142         if (priv->adapter->monitormode != LBS_MONITOR_OFF) {
 143                 skb->protocol = eth_type_trans(skb, priv->rtap_net_dev);
 144         } else {
 145                 if (priv->mesh_dev && IS_MESH_FRAME(skb))
 146                         skb->protocol = eth_type_trans(skb, priv->mesh_dev);
 147                 else
 148                         skb->protocol = eth_type_trans(skb, priv->dev);
 149         }
 150         skb->ip_summed = CHECKSUM_UNNECESSARY;
 151         netif_rx(skb);
 152 }
 153
 154 /**
 155  *  @brief This function processes received packet and forwards it
 156  *  to kernel/upper layer
 157  *
 158  *  @param priv    A pointer to struct lbs_private
 159  *  @param skb     A pointer to skb which includes the received packet
 160  *  @return        0 or -1
 161  */
 162 int lbs_process_rxed_packet(struct lbs_private *priv, struct sk_buff *skb)
 163 {
 164         struct lbs_adapter *adapter = priv->adapter;
 165         int ret = 0;
 166
 167         struct rxpackethdr *p_rx_pkt;
 168         struct rxpd *p_rx_pd;
 169
 170         int hdrchop;
 171         struct ethhdr *p_ethhdr;
 172
 173         const u8 rfc1042_eth_hdr[] = { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };
 174
 175         lbs_deb_enter(LBS_DEB_RX);
 176
 177         if (priv->adapter->monitormode != LBS_MONITOR_OFF)
 178                 return process_rxed_802_11_packet(priv, skb);
 179
 180         p_rx_pkt = (struct rxpackethdr *) skb->data;
 181         p_rx_pd = &p_rx_pkt->rx_pd;
 182         if (p_rx_pd->rx_control & RxPD_MESH_FRAME)
 183                 SET_MESH_FRAME(skb);
 184         else
 185                 UNSET_MESH_FRAME(skb);
 186
 187         lbs_deb_hex(LBS_DEB_RX, "RX Data: Before chop rxpd", skb->data,
 188                  min_t(unsigned int, skb->len, 100));
 189
 190         if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) {
 191                 lbs_deb_rx("rx err: frame received with bad length\n");
 192                 priv->stats.rx_length_errors++;
 193                 ret = 0;
 194                 goto done;
 195         }
 196
 197         /*
 198          * Check rxpd status and update 802.3 stat,
 199          */
 200         if (!(p_rx_pd->status & cpu_to_le16(MRVDRV_RXPD_STATUS_OK))) {
 201                 lbs_deb_rx("rx err: frame received with bad status\n");
 202                 lbs_pr_alert("rxpd not ok\n");
 203                 priv->stats.rx_errors++;
 204                 ret = 0;
 205                 goto done;
 206         }
 207
 208         lbs_deb_rx("rx data: skb->len-sizeof(RxPd) = %d-%zd = %zd\n",
 209                skb->len, sizeof(struct rxpd), skb->len - sizeof(struct rxpd));
 210
 211         lbs_deb_hex(LBS_DEB_RX, "RX Data: Dest", p_rx_pkt->eth803_hdr.dest_addr,
 212                 sizeof(p_rx_pkt->eth803_hdr.dest_addr));
 213         lbs_deb_hex(LBS_DEB_RX, "RX Data: Src", p_rx_pkt->eth803_hdr.src_addr,
 214                 sizeof(p_rx_pkt->eth803_hdr.src_addr));
 215
 216         if (memcmp(&p_rx_pkt->rfc1042_hdr,
 217                    rfc1042_eth_hdr, sizeof(rfc1042_eth_hdr)) == 0) {
 218                 /*
 219                  *  Replace the 803 header and rfc1042 header (llc/snap) with an
 220                  *    EthernetII header, keep the src/dst and snap_type (ethertype)
 221                  *
 222                  *  The firmware only passes up SNAP frames converting
 223                  *    all RX Data from 802.11 to 802.2/LLC/SNAP frames.
 224                  *
 225                  *  To create the Ethernet II, just move the src, dst address right
 226                  *    before the snap_type.
 227                  */
 228                 p_ethhdr = (struct ethhdr *)
 229                     ((u8 *) & p_rx_pkt->eth803_hdr
 230                      + sizeof(p_rx_pkt->eth803_hdr) + sizeof(p_rx_pkt->rfc1042_hdr)
 231                      - sizeof(p_rx_pkt->eth803_hdr.dest_addr)
 232                      - sizeof(p_rx_pkt->eth803_hdr.src_addr)
 233                      - sizeof(p_rx_pkt->rfc1042_hdr.snap_type));
 234
 235                 memcpy(p_ethhdr->h_source, p_rx_pkt->eth803_hdr.src_addr,
 236                        sizeof(p_ethhdr->h_source));
 237                 memcpy(p_ethhdr->h_dest, p_rx_pkt->eth803_hdr.dest_addr,
 238                        sizeof(p_ethhdr->h_dest));
 239
 240                 /* Chop off the rxpd + the excess memory from the 802.2/llc/snap header
 241                  *   that was removed
 242                  */
 243                 hdrchop = (u8 *) p_ethhdr - (u8 *) p_rx_pkt;
 244         } else {
 245                 lbs_deb_hex(LBS_DEB_RX, "RX Data: LLC/SNAP",
 246                         (u8 *) & p_rx_pkt->rfc1042_hdr,
 247                         sizeof(p_rx_pkt->rfc1042_hdr));
 248
 249                 /* Chop off the rxpd */
 250                 hdrchop = (u8 *) & p_rx_pkt->eth803_hdr - (u8 *) p_rx_pkt;
 251         }
 252
 253         /* Chop off the leading header bytes so the skb points to the start of
 254          *   either the reconstructed EthII frame or the 802.2/llc/snap frame
 255          */
 256         skb_pull(skb, hdrchop);
 257
 258         /* Take the data rate from the rxpd structure
 259          * only if the rate is auto
 260          */
 261         if (adapter->auto_rate)
 262                 adapter->cur_rate = lbs_fw_index_to_data_rate(p_rx_pd->rx_rate);
 263
 264         lbs_compute_rssi(priv, p_rx_pd);
 265
 266         lbs_deb_rx("rx data: size of actual packet %d\n", skb->len);
 267         priv->stats.rx_bytes += skb->len;
 268         priv->stats.rx_packets++;
 269
 270         lbs_upload_rx_packet(priv, skb);
 271
 272         ret = 0;
 273 done:
 274         lbs_deb_leave_args(LBS_DEB_RX, "ret %d", ret);
 275         return ret;
 276 }
 277 EXPORT_SYMBOL_GPL(lbs_process_rxed_packet);
 278
 279 /**
 280  *  @brief This function converts Tx/Rx rates from the Marvell WLAN format
 281  *  (see Table 2 in Section 3.1) to IEEE80211_RADIOTAP_RATE units (500 Kb/s)
 282  *
 283  *  @param rate    Input rate
 284  *  @return        Output Rate (0 if invalid)
 285  */
 286 static u8 convert_mv_rate_to_radiotap(u8 rate)
 287 {
 288         switch (rate) {
 289         case 0:         /*   1 Mbps */
 290                 return 2;
 291         case 1:         /*   2 Mbps */
 292                 return 4;
 293         case 2:         /* 5.5 Mbps */
 294                 return 11;
 295         case 3:         /*  11 Mbps */
 296                 return 22;
 297         /* case 4: reserved */
 298         case 5:         /*   6 Mbps */
 299                 return 12;
 300         case 6:         /*   9 Mbps */
 301                 return 18;
 302         case 7:         /*  12 Mbps */
 303                 return 24;
 304         case 8:         /*  18 Mbps */
 305                 return 36;
 306         case 9:         /*  24 Mbps */
 307                 return 48;
 308         case 10:                /*  36 Mbps */
 309                 return 72;
 310         case 11:                /*  48 Mbps */
 311                 return 96;
 312         case 12:                /*  54 Mbps */
 313                 return 108;
 314         }
 315         lbs_pr_alert("Invalid Marvell WLAN rate %i\n", rate);
 316         return 0;
 317 }
 318
 319 /**
 320  *  @brief This function processes a received 802.11 packet and forwards it
 321  *  to kernel/upper layer
 322  *
 323  *  @param priv    A pointer to struct lbs_private
 324  *  @param skb     A pointer to skb which includes the received packet
 325  *  @return        0 or -1
 326  */
 327 static int process_rxed_802_11_packet(struct lbs_private *priv,
 328         struct sk_buff *skb)
 329 {
 330         struct lbs_adapter *adapter = priv->adapter;
 331         int ret = 0;
 332
 333         struct rx80211packethdr *p_rx_pkt;
 334         struct rxpd *prxpd;
 335         struct rx_radiotap_hdr radiotap_hdr;
 336         struct rx_radiotap_hdr *pradiotap_hdr;
 337
 338         lbs_deb_enter(LBS_DEB_RX);
 339
 340         p_rx_pkt = (struct rx80211packethdr *) skb->data;
 341         prxpd = &p_rx_pkt->rx_pd;
 342
 343         // lbs_deb_hex(LBS_DEB_RX, "RX Data: Before chop rxpd", skb->data, min(skb->len, 100));
 344
 345         if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) {
 346                 lbs_deb_rx("rx err: frame received wit bad length\n");
 347                 priv->stats.rx_length_errors++;
 348                 ret = 0;
 349                 goto done;
 350         }
 351
 352         /*
 353          * Check rxpd status and update 802.3 stat,
 354          */
 355         if (!(prxpd->status & cpu_to_le16(MRVDRV_RXPD_STATUS_OK))) {
 356                 //lbs_deb_rx("rx err: frame received with bad status\n");
 357                 priv->stats.rx_errors++;
 358         }
 359
 360         lbs_deb_rx("rx data: skb->len-sizeof(RxPd) = %d-%zd = %zd\n",
 361                skb->len, sizeof(struct rxpd), skb->len - sizeof(struct rxpd));
 362
 363         /* create the exported radio header */
 364         if (priv->adapter->monitormode == LBS_MONITOR_OFF) {
 365                 /* no radio header */
 366                 /* chop the rxpd */
 367                 skb_pull(skb, sizeof(struct rxpd));
 368         }
 369
 370         else {
 371                 /* radiotap header */
 372                 radiotap_hdr.hdr.it_version = 0;
 373                 /* XXX must check this value for pad */
 374                 radiotap_hdr.hdr.it_pad = 0;
 375                 radiotap_hdr.hdr.it_len = cpu_to_le16 (sizeof(struct rx_radiotap_hdr));
 376                 radiotap_hdr.hdr.it_present = cpu_to_le32 (RX_RADIOTAP_PRESENT);
 377                 /* unknown values */
 378                 radiotap_hdr.flags = 0;
 379                 radiotap_hdr.chan_freq = 0;
 380                 radiotap_hdr.chan_flags = 0;
 381                 radiotap_hdr.antenna = 0;
 382                 /* known values */
 383                 radiotap_hdr.rate = convert_mv_rate_to_radiotap(prxpd->rx_rate);
 384                 /* XXX must check no carryout */
 385                 radiotap_hdr.antsignal = prxpd->snr + prxpd->nf;
 386                 radiotap_hdr.rx_flags = 0;
 387                 if (!(prxpd->status & cpu_to_le16(MRVDRV_RXPD_STATUS_OK)))
 388                         radiotap_hdr.rx_flags |= IEEE80211_RADIOTAP_F_RX_BADFCS;
 389                 //memset(radiotap_hdr.pad, 0x11, IEEE80211_RADIOTAP_HDRLEN - 18);
 390
 391                 /* chop the rxpd */
 392                 skb_pull(skb, sizeof(struct rxpd));
 393
 394                 /* add space for the new radio header */
 395                 if ((skb_headroom(skb) < sizeof(struct rx_radiotap_hdr)) &&
 396                     pskb_expand_head(skb, sizeof(struct rx_radiotap_hdr), 0,
 397                                      GFP_ATOMIC)) {
 398                         lbs_pr_alert("%s: couldn't pskb_expand_head\n",
 399                                __func__);
 400                 }
 401
 402                 pradiotap_hdr =
 403                     (struct rx_radiotap_hdr *)skb_push(skb,
 404                                                      sizeof(struct
 405                                                             rx_radiotap_hdr));
 406                 memcpy(pradiotap_hdr, &radiotap_hdr,
 407                        sizeof(struct rx_radiotap_hdr));
 408         }
 409
 410         /* Take the data rate from the rxpd structure
 411          * only if the rate is auto
 412          */
 413         if (adapter->auto_rate)
 414                 adapter->cur_rate = lbs_fw_index_to_data_rate(prxpd->rx_rate);
 415
 416         lbs_compute_rssi(priv, prxpd);
 417
 418         lbs_deb_rx("rx data: size of actual packet %d\n", skb->len);
 419         priv->stats.rx_bytes += skb->len;
 420         priv->stats.rx_packets++;
 421
 422         lbs_upload_rx_packet(priv, skb);
 423
 424         ret = 0;
 425
 426 done:
 427         lbs_deb_leave_args(LBS_DEB_RX, "ret %d", ret);
 428         return ret;
 429 }