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