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/hardirq.h>
   9 #include <linux/slab.h>
  10 #include <linux/types.h>
  11 #include <linux/export.h>
  12 #include <net/cfg80211.h>
  13
  14 #include "defs.h"
  15 #include "host.h"
  16 #include "radiotap.h"
  17 #include "decl.h"
  18 #include "dev.h"
  19 #include "mesh.h"
  20
  21 struct eth803hdr {
  22         u8 dest_addr[6];
  23         u8 src_addr[6];
  24         u16 h803_len;
  25 } __packed;
  26
  27 struct rfc1042hdr {
  28         u8 llc_dsap;
  29         u8 llc_ssap;
  30         u8 llc_ctrl;
  31         u8 snap_oui[3];
  32         u16 snap_type;
  33 } __packed;
  34
  35 struct rxpackethdr {
  36         struct eth803hdr eth803_hdr;
  37         struct rfc1042hdr rfc1042_hdr;
  38 } __packed;
  39
  40 struct rx80211packethdr {
  41         struct rxpd rx_pd;
  42         void *eth80211_hdr;
  43 } __packed;
  44
  45 static int process_rxed_802_11_packet(struct lbs_private *priv,
  46         struct sk_buff *skb);
  47
  48 /**
  49  * lbs_process_rxed_packet - processes received packet and forwards it
  50  * to kernel/upper layer
  51  *
  52  * @priv:       A pointer to &struct lbs_private
  53  * @skb:        A pointer to skb which includes the received packet
  54  * returns:     0 or -1
  55  */
  56 int lbs_process_rxed_packet(struct lbs_private *priv, struct sk_buff *skb)
  57 {
  58         int ret = 0;
  59         struct net_device *dev = priv->dev;
  60         struct rxpackethdr *p_rx_pkt;
  61         struct rxpd *p_rx_pd;
  62         int hdrchop;
  63         struct ethhdr *p_ethhdr;
  64         static const u8 rfc1042_eth_hdr[] = {
  65                 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00
  66         };
  67
  68         lbs_deb_enter(LBS_DEB_RX);
  69
  70         BUG_ON(!skb);
  71
  72         skb->ip_summed = CHECKSUM_NONE;
  73
  74         if (priv->wdev->iftype == NL80211_IFTYPE_MONITOR)
  75                 return process_rxed_802_11_packet(priv, skb);
  76
  77         p_rx_pd = (struct rxpd *) skb->data;
  78         p_rx_pkt = (struct rxpackethdr *) ((u8 *)p_rx_pd +
  79                 le32_to_cpu(p_rx_pd->pkt_ptr));
  80
  81         dev = lbs_mesh_set_dev(priv, dev, p_rx_pd);
  82
  83         lbs_deb_hex(LBS_DEB_RX, "RX Data: Before chop rxpd", skb->data,
  84                  min_t(unsigned int, skb->len, 100));
  85
  86         if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) {
  87                 lbs_deb_rx("rx err: frame received with bad length\n");
  88                 dev->stats.rx_length_errors++;
  89                 ret = 0;
  90                 dev_kfree_skb(skb);
  91                 goto done;
  92         }
  93
  94         lbs_deb_rx("rx data: skb->len - pkt_ptr = %d-%zd = %zd\n",
  95                 skb->len, (size_t)le32_to_cpu(p_rx_pd->pkt_ptr),
  96                 skb->len - (size_t)le32_to_cpu(p_rx_pd->pkt_ptr));
  97
  98         lbs_deb_hex(LBS_DEB_RX, "RX Data: Dest", p_rx_pkt->eth803_hdr.dest_addr,
  99                 sizeof(p_rx_pkt->eth803_hdr.dest_addr));
 100         lbs_deb_hex(LBS_DEB_RX, "RX Data: Src", p_rx_pkt->eth803_hdr.src_addr,
 101                 sizeof(p_rx_pkt->eth803_hdr.src_addr));
 102
 103         if (memcmp(&p_rx_pkt->rfc1042_hdr,
 104                    rfc1042_eth_hdr, sizeof(rfc1042_eth_hdr)) == 0) {
 105                 /*
 106                  *  Replace the 803 header and rfc1042 header (llc/snap) with an
 107                  *    EthernetII header, keep the src/dst and snap_type (ethertype)
 108                  *
 109                  *  The firmware only passes up SNAP frames converting
 110                  *    all RX Data from 802.11 to 802.2/LLC/SNAP frames.
 111                  *
 112                  *  To create the Ethernet II, just move the src, dst address right
 113                  *    before the snap_type.
 114                  */
 115                 p_ethhdr = (struct ethhdr *)
 116                     ((u8 *) &p_rx_pkt->eth803_hdr
 117                      + sizeof(p_rx_pkt->eth803_hdr) + sizeof(p_rx_pkt->rfc1042_hdr)
 118                      - sizeof(p_rx_pkt->eth803_hdr.dest_addr)
 119                      - sizeof(p_rx_pkt->eth803_hdr.src_addr)
 120                      - sizeof(p_rx_pkt->rfc1042_hdr.snap_type));
 121
 122                 memcpy(p_ethhdr->h_source, p_rx_pkt->eth803_hdr.src_addr,
 123                        sizeof(p_ethhdr->h_source));
 124                 memcpy(p_ethhdr->h_dest, p_rx_pkt->eth803_hdr.dest_addr,
 125                        sizeof(p_ethhdr->h_dest));
 126
 127                 /* Chop off the rxpd + the excess memory from the 802.2/llc/snap header
 128                  *   that was removed
 129                  */
 130                 hdrchop = (u8 *)p_ethhdr - (u8 *)p_rx_pd;
 131         } else {
 132                 lbs_deb_hex(LBS_DEB_RX, "RX Data: LLC/SNAP",
 133                         (u8 *) &p_rx_pkt->rfc1042_hdr,
 134                         sizeof(p_rx_pkt->rfc1042_hdr));
 135
 136                 /* Chop off the rxpd */
 137                 hdrchop = (u8 *)&p_rx_pkt->eth803_hdr - (u8 *)p_rx_pd;
 138         }
 139
 140         /* Chop off the leading header bytes so the skb points to the start of
 141          *   either the reconstructed EthII frame or the 802.2/llc/snap frame
 142          */
 143         skb_pull(skb, hdrchop);
 144
 145         priv->cur_rate = lbs_fw_index_to_data_rate(p_rx_pd->rx_rate);
 146
 147         lbs_deb_rx("rx data: size of actual packet %d\n", skb->len);
 148         dev->stats.rx_bytes += skb->len;
 149         dev->stats.rx_packets++;
 150
 151         skb->protocol = eth_type_trans(skb, dev);
 152         if (in_interrupt())
 153                 netif_rx(skb);
 154         else
 155                 netif_rx_ni(skb);
 156
 157         ret = 0;
 158 done:
 159         lbs_deb_leave_args(LBS_DEB_RX, "ret %d", ret);
 160         return ret;
 161 }
 162 EXPORT_SYMBOL_GPL(lbs_process_rxed_packet);
 163
 164 /**
 165  * convert_mv_rate_to_radiotap - converts Tx/Rx rates from Marvell WLAN format
 166  * (see Table 2 in Section 3.1) to IEEE80211_RADIOTAP_RATE units (500 Kb/s)
 167  *
 168  * @rate:       Input rate
 169  * returns:     Output Rate (0 if invalid)
 170  */
 171 static u8 convert_mv_rate_to_radiotap(u8 rate)
 172 {
 173         switch (rate) {
 174         case 0:         /*   1 Mbps */
 175                 return 2;
 176         case 1:         /*   2 Mbps */
 177                 return 4;
 178         case 2:         /* 5.5 Mbps */
 179                 return 11;
 180         case 3:         /*  11 Mbps */
 181                 return 22;
 182         /* case 4: reserved */
 183         case 5:         /*   6 Mbps */
 184                 return 12;
 185         case 6:         /*   9 Mbps */
 186                 return 18;
 187         case 7:         /*  12 Mbps */
 188                 return 24;
 189         case 8:         /*  18 Mbps */
 190                 return 36;
 191         case 9:         /*  24 Mbps */
 192                 return 48;
 193         case 10:                /*  36 Mbps */
 194                 return 72;
 195         case 11:                /*  48 Mbps */
 196                 return 96;
 197         case 12:                /*  54 Mbps */
 198                 return 108;
 199         }
 200         pr_alert("Invalid Marvell WLAN rate %i\n", rate);
 201         return 0;
 202 }
 203
 204 /**
 205  * process_rxed_802_11_packet - processes a received 802.11 packet and forwards
 206  * it to kernel/upper layer
 207  *
 208  * @priv:       A pointer to &struct lbs_private
 209  * @skb:        A pointer to skb which includes the received packet
 210  * returns:     0 or -1
 211  */
 212 static int process_rxed_802_11_packet(struct lbs_private *priv,
 213         struct sk_buff *skb)
 214 {
 215         int ret = 0;
 216         struct net_device *dev = priv->dev;
 217         struct rx80211packethdr *p_rx_pkt;
 218         struct rxpd *prxpd;
 219         struct rx_radiotap_hdr radiotap_hdr;
 220         struct rx_radiotap_hdr *pradiotap_hdr;
 221
 222         lbs_deb_enter(LBS_DEB_RX);
 223
 224         p_rx_pkt = (struct rx80211packethdr *) skb->data;
 225         prxpd = &p_rx_pkt->rx_pd;
 226
 227         /* lbs_deb_hex(LBS_DEB_RX, "RX Data: Before chop rxpd", skb->data, min(skb->len, 100)); */
 228
 229         if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) {
 230                 lbs_deb_rx("rx err: frame received with bad length\n");
 231                 dev->stats.rx_length_errors++;
 232                 ret = -EINVAL;
 233                 kfree_skb(skb);
 234                 goto done;
 235         }
 236
 237         lbs_deb_rx("rx data: skb->len-sizeof(RxPd) = %d-%zd = %zd\n",
 238                skb->len, sizeof(struct rxpd), skb->len - sizeof(struct rxpd));
 239
 240         /* create the exported radio header */
 241
 242         /* radiotap header */
 243         memset(&radiotap_hdr, 0, sizeof(radiotap_hdr));
 244         /* XXX must check radiotap_hdr.hdr.it_pad for pad */
 245         radiotap_hdr.hdr.it_len = cpu_to_le16 (sizeof(struct rx_radiotap_hdr));
 246         radiotap_hdr.hdr.it_present = cpu_to_le32 (RX_RADIOTAP_PRESENT);
 247         radiotap_hdr.rate = convert_mv_rate_to_radiotap(prxpd->rx_rate);
 248         /* XXX must check no carryout */
 249         radiotap_hdr.antsignal = prxpd->snr + prxpd->nf;
 250
 251         /* chop the rxpd */
 252         skb_pull(skb, sizeof(struct rxpd));
 253
 254         /* add space for the new radio header */
 255         if ((skb_headroom(skb) < sizeof(struct rx_radiotap_hdr)) &&
 256             pskb_expand_head(skb, sizeof(struct rx_radiotap_hdr), 0, GFP_ATOMIC)) {
 257                 netdev_alert(dev, "%s: couldn't pskb_expand_head\n", __func__);
 258                 ret = -ENOMEM;
 259                 kfree_skb(skb);
 260                 goto done;
 261         }
 262
 263         pradiotap_hdr = (void *)skb_push(skb, sizeof(struct rx_radiotap_hdr));
 264         memcpy(pradiotap_hdr, &radiotap_hdr, sizeof(struct rx_radiotap_hdr));
 265
 266         priv->cur_rate = lbs_fw_index_to_data_rate(prxpd->rx_rate);
 267
 268         lbs_deb_rx("rx data: size of actual packet %d\n", skb->len);
 269         dev->stats.rx_bytes += skb->len;
 270         dev->stats.rx_packets++;
 271
 272         skb->protocol = eth_type_trans(skb, priv->dev);
 273
 274         if (in_interrupt())
 275                 netif_rx(skb);
 276         else
 277                 netif_rx_ni(skb);
 278
 279         ret = 0;
 280
 281 done:
 282         lbs_deb_leave_args(LBS_DEB_RX, "ret %d", ret);
 283         return ret;
 284 }