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(wlan_private * priv, struct sk_buff *skb);
  39
  40 /**
  41  *  @brief This function computes the avgSNR .
  42  *
  43  *  @param priv    A pointer to wlan_private structure
  44  *  @return        avgSNR
  45  */
  46 static u8 wlan_getavgsnr(wlan_private * priv)
  47 {
  48         u8 i;
  49         u16 temp = 0;
  50         wlan_adapter *adapter = priv->adapter;
  51         if (adapter->numSNRNF == 0)
  52                 return 0;
  53         for (i = 0; i < adapter->numSNRNF; i++)
  54                 temp += adapter->rawSNR[i];
  55         return (u8) (temp / adapter->numSNRNF);
  56
  57 }
  58
  59 /**
  60  *  @brief This function computes the AvgNF
  61  *
  62  *  @param priv    A pointer to wlan_private structure
  63  *  @return        AvgNF
  64  */
  65 static u8 wlan_getavgnf(wlan_private * priv)
  66 {
  67         u8 i;
  68         u16 temp = 0;
  69         wlan_adapter *adapter = priv->adapter;
  70         if (adapter->numSNRNF == 0)
  71                 return 0;
  72         for (i = 0; i < adapter->numSNRNF; i++)
  73                 temp += adapter->rawNF[i];
  74         return (u8) (temp / adapter->numSNRNF);
  75
  76 }
  77
  78 /**
  79  *  @brief This function save the raw SNR/NF to our internel buffer
  80  *
  81  *  @param priv    A pointer to wlan_private structure
  82  *  @param prxpd   A pointer to rxpd structure of received packet
  83  *  @return        n/a
  84  */
  85 static void wlan_save_rawSNRNF(wlan_private * priv, struct rxpd *p_rx_pd)
  86 {
  87         wlan_adapter *adapter = priv->adapter;
  88         if (adapter->numSNRNF < adapter->data_avg_factor)
  89                 adapter->numSNRNF++;
  90         adapter->rawSNR[adapter->nextSNRNF] = p_rx_pd->snr;
  91         adapter->rawNF[adapter->nextSNRNF] = p_rx_pd->nf;
  92         adapter->nextSNRNF++;
  93         if (adapter->nextSNRNF >= adapter->data_avg_factor)
  94                 adapter->nextSNRNF = 0;
  95         return;
  96 }
  97
  98 /**
  99  *  @brief This function computes the RSSI in received packet.
 100  *
 101  *  @param priv    A pointer to wlan_private structure
 102  *  @param prxpd   A pointer to rxpd structure of received packet
 103  *  @return        n/a
 104  */
 105 static void wlan_compute_rssi(wlan_private * priv, struct rxpd *p_rx_pd)
 106 {
 107         wlan_adapter *adapter = priv->adapter;
 108
 109         lbs_deb_enter(LBS_DEB_RX);
 110
 111         lbs_deb_rx("rxpd: SNR %d, NF %d\n", p_rx_pd->snr, p_rx_pd->nf);
 112         lbs_deb_rx("before computing SNR: SNR-avg = %d, NF-avg = %d\n",
 113                adapter->SNR[TYPE_RXPD][TYPE_AVG] / AVG_SCALE,
 114                adapter->NF[TYPE_RXPD][TYPE_AVG] / AVG_SCALE);
 115
 116         adapter->SNR[TYPE_RXPD][TYPE_NOAVG] = p_rx_pd->snr;
 117         adapter->NF[TYPE_RXPD][TYPE_NOAVG] = p_rx_pd->nf;
 118         wlan_save_rawSNRNF(priv, p_rx_pd);
 119
 120         adapter->rxpd_rate = p_rx_pd->rx_rate;
 121
 122         adapter->SNR[TYPE_RXPD][TYPE_AVG] = wlan_getavgsnr(priv) * AVG_SCALE;
 123         adapter->NF[TYPE_RXPD][TYPE_AVG] = wlan_getavgnf(priv) * AVG_SCALE;
 124         lbs_deb_rx("after computing SNR: SNR-avg = %d, NF-avg = %d\n",
 125                adapter->SNR[TYPE_RXPD][TYPE_AVG] / AVG_SCALE,
 126                adapter->NF[TYPE_RXPD][TYPE_AVG] / AVG_SCALE);
 127
 128         adapter->RSSI[TYPE_RXPD][TYPE_NOAVG] =
 129             CAL_RSSI(adapter->SNR[TYPE_RXPD][TYPE_NOAVG],
 130                      adapter->NF[TYPE_RXPD][TYPE_NOAVG]);
 131
 132         adapter->RSSI[TYPE_RXPD][TYPE_AVG] =
 133             CAL_RSSI(adapter->SNR[TYPE_RXPD][TYPE_AVG] / AVG_SCALE,
 134                      adapter->NF[TYPE_RXPD][TYPE_AVG] / AVG_SCALE);
 135
 136         lbs_deb_leave(LBS_DEB_RX);
 137 }
 138
 139 void libertas_upload_rx_packet(wlan_private * priv, struct sk_buff *skb)
 140 {
 141         lbs_deb_rx("skb->data %p\n", skb->data);
 142
 143         if (priv->mesh_dev && IS_MESH_FRAME(skb))
 144                 skb->protocol = eth_type_trans(skb, priv->mesh_dev);
 145         else
 146                 skb->protocol = eth_type_trans(skb, priv->dev);
 147         skb->ip_summed = CHECKSUM_UNNECESSARY;
 148
 149         netif_rx(skb);
 150 }
 151
 152 /**
 153  *  @brief This function processes received packet and forwards it
 154  *  to kernel/upper layer
 155  *
 156  *  @param priv    A pointer to wlan_private
 157  *  @param skb     A pointer to skb which includes the received packet
 158  *  @return        0 or -1
 159  */
 160 int libertas_process_rxed_packet(wlan_private * priv, struct sk_buff *skb)
 161 {
 162         wlan_adapter *adapter = priv->adapter;
 163         int ret = 0;
 164
 165         struct rxpackethdr *p_rx_pkt;
 166         struct rxpd *p_rx_pd;
 167
 168         int hdrchop;
 169         struct ethhdr *p_ethhdr;
 170
 171         const u8 rfc1042_eth_hdr[] = { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };
 172
 173         lbs_deb_enter(LBS_DEB_RX);
 174
 175         if (priv->adapter->debugmode & MRVDRV_DEBUG_RX_PATH)
 176                 lbs_dbg_hex("RX packet: ", skb->data,
 177                          min_t(unsigned int, skb->len, 100));
 178
 179         if (priv->adapter->linkmode == WLAN_LINKMODE_802_11)
 180                 return process_rxed_802_11_packet(priv, skb);
 181
 182         p_rx_pkt = (struct rxpackethdr *) skb->data;
 183         p_rx_pd = &p_rx_pkt->rx_pd;
 184         if (p_rx_pd->rx_control & RxPD_MESH_FRAME)
 185                 SET_MESH_FRAME(skb);
 186         else
 187                 UNSET_MESH_FRAME(skb);
 188
 189         lbs_dbg_hex("RX Data: Before chop rxpd", skb->data,
 190                  min_t(unsigned int, skb->len, 100));
 191
 192         if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) {
 193                 lbs_deb_rx("rx err: frame received with bad length\n");
 194                 priv->stats.rx_length_errors++;
 195                 ret = 0;
 196                 goto done;
 197         }
 198
 199         /*
 200          * Check rxpd status and update 802.3 stat,
 201          */
 202         if (!(p_rx_pd->status & cpu_to_le16(MRVDRV_RXPD_STATUS_OK))) {
 203                 lbs_deb_rx("rx err: frame received with bad status\n");
 204                 lbs_pr_alert("rxpd not ok\n");
 205                 priv->stats.rx_errors++;
 206                 ret = 0;
 207                 goto done;
 208         }
 209
 210         lbs_deb_rx("rx data: skb->len-sizeof(RxPd) = %d-%zd = %zd\n",
 211                skb->len, sizeof(struct rxpd), skb->len - sizeof(struct rxpd));
 212
 213         lbs_dbg_hex("RX Data: Dest", p_rx_pkt->eth803_hdr.dest_addr,
 214                 sizeof(p_rx_pkt->eth803_hdr.dest_addr));
 215         lbs_dbg_hex("RX Data: Src", p_rx_pkt->eth803_hdr.src_addr,
 216                 sizeof(p_rx_pkt->eth803_hdr.src_addr));
 217
 218         if (memcmp(&p_rx_pkt->rfc1042_hdr,
 219                    rfc1042_eth_hdr, sizeof(rfc1042_eth_hdr)) == 0) {
 220                 /*
 221                  *  Replace the 803 header and rfc1042 header (llc/snap) with an
 222                  *    EthernetII header, keep the src/dst and snap_type (ethertype)
 223                  *
 224                  *  The firmware only passes up SNAP frames converting
 225                  *    all RX Data from 802.11 to 802.2/LLC/SNAP frames.
 226                  *
 227                  *  To create the Ethernet II, just move the src, dst address right
 228                  *    before the snap_type.
 229                  */
 230                 p_ethhdr = (struct ethhdr *)
 231                     ((u8 *) & p_rx_pkt->eth803_hdr
 232                      + sizeof(p_rx_pkt->eth803_hdr) + sizeof(p_rx_pkt->rfc1042_hdr)
 233                      - sizeof(p_rx_pkt->eth803_hdr.dest_addr)
 234                      - sizeof(p_rx_pkt->eth803_hdr.src_addr)
 235                      - sizeof(p_rx_pkt->rfc1042_hdr.snap_type));
 236
 237                 memcpy(p_ethhdr->h_source, p_rx_pkt->eth803_hdr.src_addr,
 238                        sizeof(p_ethhdr->h_source));
 239                 memcpy(p_ethhdr->h_dest, p_rx_pkt->eth803_hdr.dest_addr,
 240                        sizeof(p_ethhdr->h_dest));
 241
 242                 /* Chop off the rxpd + the excess memory from the 802.2/llc/snap header
 243                  *   that was removed
 244                  */
 245                 hdrchop = (u8 *) p_ethhdr - (u8 *) p_rx_pkt;
 246         } else {
 247                 lbs_dbg_hex("RX Data: LLC/SNAP",
 248                         (u8 *) & p_rx_pkt->rfc1042_hdr,
 249                         sizeof(p_rx_pkt->rfc1042_hdr));
 250
 251                 /* Chop off the rxpd */
 252                 hdrchop = (u8 *) & p_rx_pkt->eth803_hdr - (u8 *) p_rx_pkt;
 253         }
 254
 255         /* Chop off the leading header bytes so the skb points to the start of
 256          *   either the reconstructed EthII frame or the 802.2/llc/snap frame
 257          */
 258         skb_pull(skb, hdrchop);
 259
 260         /* Take the data rate from the rxpd structure
 261          * only if the rate is auto
 262          */
 263         if (adapter->is_datarate_auto)
 264                 adapter->datarate = libertas_index_to_data_rate(p_rx_pd->rx_rate);
 265
 266         wlan_compute_rssi(priv, p_rx_pd);
 267
 268         lbs_deb_rx("rx data: size of actual packet %d\n", skb->len);
 269         priv->stats.rx_bytes += skb->len;
 270         priv->stats.rx_packets++;
 271
 272         libertas_upload_rx_packet(priv, skb);
 273
 274         ret = 0;
 275 done:
 276         lbs_deb_leave_args(LBS_DEB_RX, "ret %d", ret);
 277         return ret;
 278 }
 279 EXPORT_SYMBOL_GPL(libertas_process_rxed_packet);
 280
 281 /**
 282  *  @brief This function converts Tx/Rx rates from the Marvell WLAN format
 283  *  (see Table 2 in Section 3.1) to IEEE80211_RADIOTAP_RATE units (500 Kb/s)
 284  *
 285  *  @param rate    Input rate
 286  *  @return        Output Rate (0 if invalid)
 287  */
 288 static u8 convert_mv_rate_to_radiotap(u8 rate)
 289 {
 290         switch (rate) {
 291         case 0:         /*   1 Mbps */
 292                 return 2;
 293         case 1:         /*   2 Mbps */
 294                 return 4;
 295         case 2:         /* 5.5 Mbps */
 296                 return 11;
 297         case 3:         /*  11 Mbps */
 298                 return 22;
 299         case 4:         /*   6 Mbps */
 300                 return 12;
 301         case 5:         /*   9 Mbps */
 302                 return 18;
 303         case 6:         /*  12 Mbps */
 304                 return 24;
 305         case 7:         /*  18 Mbps */
 306                 return 36;
 307         case 8:         /*  24 Mbps */
 308                 return 48;
 309         case 9:         /*  36 Mbps */
 310                 return 72;
 311         case 10:                /*  48 Mbps */
 312                 return 96;
 313         case 11:                /*  54 Mbps */
 314                 return 108;
 315         }
 316         lbs_pr_alert("Invalid Marvell WLAN rate %i\n", rate);
 317         return 0;
 318 }
 319
 320 /**
 321  *  @brief This function processes a received 802.11 packet and forwards it
 322  *  to kernel/upper layer
 323  *
 324  *  @param priv    A pointer to wlan_private
 325  *  @param skb     A pointer to skb which includes the received packet
 326  *  @return        0 or -1
 327  */
 328 static int process_rxed_802_11_packet(wlan_private * priv, struct sk_buff *skb)
 329 {
 330         wlan_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_dbg_hex("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         switch (priv->adapter->radiomode) {
 365         case WLAN_RADIOMODE_NONE:
 366                 /* no radio header */
 367                 /* chop the rxpd */
 368                 skb_pull(skb, sizeof(struct rxpd));
 369                 break;
 370
 371         case WLAN_RADIOMODE_RADIOTAP:
 372                 /* radiotap header */
 373                 radiotap_hdr.hdr.it_version = 0;
 374                 /* XXX must check this value for pad */
 375                 radiotap_hdr.hdr.it_pad = 0;
 376                 radiotap_hdr.hdr.it_len = sizeof(struct rx_radiotap_hdr);
 377                 radiotap_hdr.hdr.it_present = RX_RADIOTAP_PRESENT;
 378                 /* unknown values */
 379                 radiotap_hdr.flags = 0;
 380                 radiotap_hdr.chan_freq = 0;
 381                 radiotap_hdr.chan_flags = 0;
 382                 radiotap_hdr.antenna = 0;
 383                 /* known values */
 384                 radiotap_hdr.rate = convert_mv_rate_to_radiotap(prxpd->rx_rate);
 385                 /* XXX must check no carryout */
 386                 radiotap_hdr.antsignal = prxpd->snr + prxpd->nf;
 387                 radiotap_hdr.rx_flags = 0;
 388                 if (!(prxpd->status & cpu_to_le16(MRVDRV_RXPD_STATUS_OK)))
 389                         radiotap_hdr.rx_flags |= IEEE80211_RADIOTAP_F_RX_BADFCS;
 390                 //memset(radiotap_hdr.pad, 0x11, IEEE80211_RADIOTAP_HDRLEN - 18);
 391
 392                 // lbs_dbg_hex1("RX radiomode packet BEF: ", skb->data, min(skb->len, 100));
 393
 394                 /* chop the rxpd */
 395                 skb_pull(skb, sizeof(struct rxpd));
 396
 397                 /* add space for the new radio header */
 398                 if ((skb_headroom(skb) < sizeof(struct rx_radiotap_hdr)) &&
 399                     pskb_expand_head(skb, sizeof(struct rx_radiotap_hdr), 0,
 400                                      GFP_ATOMIC)) {
 401                         lbs_pr_alert("%s: couldn't pskb_expand_head\n",
 402                                __func__);
 403                 }
 404
 405                 pradiotap_hdr =
 406                     (struct rx_radiotap_hdr *)skb_push(skb,
 407                                                      sizeof(struct
 408                                                             rx_radiotap_hdr));
 409                 memcpy(pradiotap_hdr, &radiotap_hdr,
 410                        sizeof(struct rx_radiotap_hdr));
 411                 //lbs_dbg_hex1("RX radiomode packet AFT: ", skb->data, min(skb->len, 100));
 412                 break;
 413
 414         default:
 415                 /* unknown header */
 416                 lbs_pr_alert("Unknown radiomode %i\n",
 417                        priv->adapter->radiomode);
 418                 /* don't export any header */
 419                 /* chop the rxpd */
 420                 skb_pull(skb, sizeof(struct rxpd));
 421                 break;
 422         }
 423
 424         /* Take the data rate from the rxpd structure
 425          * only if the rate is auto
 426          */
 427         if (adapter->is_datarate_auto) {
 428                 adapter->datarate = libertas_index_to_data_rate(prxpd->rx_rate);
 429         }
 430
 431         wlan_compute_rssi(priv, prxpd);
 432
 433         lbs_deb_rx("rx data: size of actual packet %d\n", skb->len);
 434         priv->stats.rx_bytes += skb->len;
 435         priv->stats.rx_packets++;
 436
 437         libertas_upload_rx_packet(priv, skb);
 438
 439         ret = 0;
 440
 441 done:
 442         lbs_deb_leave_args(LBS_DEB_RX, "ret %d", ret);
 443         return ret;
 444 }