drivers/net/wireless/orinoco/scan.c

   1 /* Helpers for managing scan queues
   2  *
   3  * See copyright notice in main.c
   4  */
   5
   6 #include <linux/kernel.h>
   7 #include <linux/string.h>
   8 #include <linux/ieee80211.h>
   9 #include <net/cfg80211.h>
  10
  11 #include "hermes.h"
  12 #include "orinoco.h"
  13 #include "main.h"
  14
  15 #include "scan.h"
  16
  17 #define ZERO_DBM_OFFSET 0x95
  18 #define MAX_SIGNAL_LEVEL 0x8A
  19 #define MIN_SIGNAL_LEVEL 0x2F
  20
  21 #define SIGNAL_TO_DBM(x)                                        \
  22         (clamp_t(s32, (x), MIN_SIGNAL_LEVEL, MAX_SIGNAL_LEVEL)  \
  23          - ZERO_DBM_OFFSET)
  24 #define SIGNAL_TO_MBM(x) (SIGNAL_TO_DBM(x) * 100)
  25
  26 static int symbol_build_supp_rates(u8 *buf, const __le16 *rates)
  27 {
  28         int i;
  29         u8 rate;
  30
  31         buf[0] = WLAN_EID_SUPP_RATES;
  32         for (i = 0; i < 5; i++) {
  33                 rate = le16_to_cpu(rates[i]);
  34                 /* NULL terminated */
  35                 if (rate == 0x0)
  36                         break;
  37                 buf[i + 2] = rate;
  38         }
  39         buf[1] = i;
  40
  41         return i + 2;
  42 }
  43
  44 static int prism_build_supp_rates(u8 *buf, const u8 *rates)
  45 {
  46         int i;
  47
  48         buf[0] = WLAN_EID_SUPP_RATES;
  49         for (i = 0; i < 8; i++) {
  50                 /* NULL terminated */
  51                 if (rates[i] == 0x0)
  52                         break;
  53                 buf[i + 2] = rates[i];
  54         }
  55         buf[1] = i;
  56
  57         /* We might still have another 2 rates, which need to go in
  58          * extended supported rates */
  59         if (i == 8 && rates[i] > 0) {
  60                 buf[10] = WLAN_EID_EXT_SUPP_RATES;
  61                 for (; i < 10; i++) {
  62                         /* NULL terminated */
  63                         if (rates[i] == 0x0)
  64                                 break;
  65                         buf[i + 2] = rates[i];
  66                 }
  67                 buf[11] = i - 8;
  68         }
  69
  70         return (i < 8) ? i + 2 : i + 4;
  71 }
  72
  73 static void orinoco_add_hostscan_result(struct orinoco_private *priv,
  74                                         const union hermes_scan_info *bss)
  75 {
  76         struct wiphy *wiphy = priv_to_wiphy(priv);
  77         struct ieee80211_channel *channel;
  78         u8 *ie;
  79         u8 ie_buf[46];
  80         u64 timestamp;
  81         s32 signal;
  82         u16 capability;
  83         u16 beacon_interval;
  84         int ie_len;
  85         int freq;
  86         int len;
  87
  88         len = le16_to_cpu(bss->a.essid_len);
  89
  90         /* Reconstruct SSID and bitrate IEs to pass up */
  91         ie_buf[0] = WLAN_EID_SSID;
  92         ie_buf[1] = len;
  93         memcpy(&ie_buf[2], bss->a.essid, len);
  94
  95         ie = ie_buf + len + 2;
  96         ie_len = ie_buf[1] + 2;
  97         switch (priv->firmware_type) {
  98         case FIRMWARE_TYPE_SYMBOL:
  99                 ie_len += symbol_build_supp_rates(ie, bss->s.rates);
 100                 break;
 101
 102         case FIRMWARE_TYPE_INTERSIL:
 103                 ie_len += prism_build_supp_rates(ie, bss->p.rates);
 104                 break;
 105
 106         case FIRMWARE_TYPE_AGERE:
 107         default:
 108                 break;
 109         }
 110
 111         freq = ieee80211_dsss_chan_to_freq(le16_to_cpu(bss->a.channel));
 112         channel = ieee80211_get_channel(wiphy, freq);
 113         timestamp = 0;
 114         capability = le16_to_cpu(bss->a.capabilities);
 115         beacon_interval = le16_to_cpu(bss->a.beacon_interv);
 116         signal = SIGNAL_TO_MBM(le16_to_cpu(bss->a.level));
 117
 118         cfg80211_inform_bss(wiphy, channel, bss->a.bssid, timestamp,
 119                             capability, beacon_interval, ie_buf, ie_len,
 120                             signal, GFP_KERNEL);
 121 }
 122
 123 void orinoco_add_extscan_result(struct orinoco_private *priv,
 124                                 struct agere_ext_scan_info *bss,
 125                                 size_t len)
 126 {
 127         struct wiphy *wiphy = priv_to_wiphy(priv);
 128         struct ieee80211_channel *channel;
 129         u8 *ie;
 130         u64 timestamp;
 131         s32 signal;
 132         u16 capability;
 133         u16 beacon_interval;
 134         size_t ie_len;
 135         int chan, freq;
 136
 137         ie_len = len - sizeof(*bss);
 138         ie = orinoco_get_ie(bss->data, ie_len, WLAN_EID_DS_PARAMS);
 139         chan = ie ? ie[2] : 0;
 140         freq = ieee80211_dsss_chan_to_freq(chan);
 141         channel = ieee80211_get_channel(wiphy, freq);
 142
 143         timestamp = le64_to_cpu(bss->timestamp);
 144         capability = le16_to_cpu(bss->capabilities);
 145         beacon_interval = le16_to_cpu(bss->beacon_interval);
 146         ie = bss->data;
 147         signal = SIGNAL_TO_MBM(bss->level);
 148
 149         cfg80211_inform_bss(wiphy, channel, bss->bssid, timestamp,
 150                             capability, beacon_interval, ie, ie_len,
 151                             signal, GFP_KERNEL);
 152 }
 153
 154 void orinoco_add_hostscan_results(struct orinoco_private *priv,
 155                                   unsigned char *buf,
 156                                   size_t len)
 157 {
 158         int offset;             /* In the scan data */
 159         size_t atom_len;
 160         bool abort = false;
 161
 162         switch (priv->firmware_type) {
 163         case FIRMWARE_TYPE_AGERE:
 164                 atom_len = sizeof(struct agere_scan_apinfo);
 165                 offset = 0;
 166                 break;
 167
 168         case FIRMWARE_TYPE_SYMBOL:
 169                 /* Lack of documentation necessitates this hack.
 170                  * Different firmwares have 68 or 76 byte long atoms.
 171                  * We try modulo first.  If the length divides by both,
 172                  * we check what would be the channel in the second
 173                  * frame for a 68-byte atom.  76-byte atoms have 0 there.
 174                  * Valid channel cannot be 0.  */
 175                 if (len % 76)
 176                         atom_len = 68;
 177                 else if (len % 68)
 178                         atom_len = 76;
 179                 else if (len >= 1292 && buf[68] == 0)
 180                         atom_len = 76;
 181                 else
 182                         atom_len = 68;
 183                 offset = 0;
 184                 break;
 185
 186         case FIRMWARE_TYPE_INTERSIL:
 187                 offset = 4;
 188                 if (priv->has_hostscan) {
 189                         atom_len = le16_to_cpup((__le16 *)buf);
 190                         /* Sanity check for atom_len */
 191                         if (atom_len < sizeof(struct prism2_scan_apinfo)) {
 192                                 printk(KERN_ERR "%s: Invalid atom_len in scan "
 193                                        "data: %zu\n", priv->ndev->name,
 194                                        atom_len);
 195                                 abort = true;
 196                                 goto scan_abort;
 197                         }
 198                 } else
 199                         atom_len = offsetof(struct prism2_scan_apinfo, atim);
 200                 break;
 201
 202         default:
 203                 abort = true;
 204                 goto scan_abort;
 205         }
 206
 207         /* Check that we got an whole number of atoms */
 208         if ((len - offset) % atom_len) {
 209                 printk(KERN_ERR "%s: Unexpected scan data length %zu, "
 210                        "atom_len %zu, offset %d\n", priv->ndev->name, len,
 211                        atom_len, offset);
 212                 abort = true;
 213                 goto scan_abort;
 214         }
 215
 216         /* Process the entries one by one */
 217         for (; offset + atom_len <= len; offset += atom_len) {
 218                 union hermes_scan_info *atom;
 219
 220                 atom = (union hermes_scan_info *) (buf + offset);
 221
 222                 orinoco_add_hostscan_result(priv, atom);
 223         }
 224
 225  scan_abort:
 226         if (priv->scan_request) {
 227                 cfg80211_scan_done(priv->scan_request, abort);
 228                 priv->scan_request = NULL;
 229         }
 230 }