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/gfp.h>
   7 #include <linux/kernel.h>
   8 #include <linux/string.h>
   9 #include <linux/ieee80211.h>
  10 #include <net/cfg80211.h>
  11
  12 #include "hermes.h"
  13 #include "orinoco.h"
  14 #include "main.h"
  15
  16 #include "scan.h"
  17
  18 #define ZERO_DBM_OFFSET 0x95
  19 #define MAX_SIGNAL_LEVEL 0x8A
  20 #define MIN_SIGNAL_LEVEL 0x2F
  21
  22 #define SIGNAL_TO_DBM(x)                                        \
  23         (clamp_t(s32, (x), MIN_SIGNAL_LEVEL, MAX_SIGNAL_LEVEL)  \
  24          - ZERO_DBM_OFFSET)
  25 #define SIGNAL_TO_MBM(x) (SIGNAL_TO_DBM(x) * 100)
  26
  27 static int symbol_build_supp_rates(u8 *buf, const __le16 *rates)
  28 {
  29         int i;
  30         u8 rate;
  31
  32         buf[0] = WLAN_EID_SUPP_RATES;
  33         for (i = 0; i < 5; i++) {
  34                 rate = le16_to_cpu(rates[i]);
  35                 /* NULL terminated */
  36                 if (rate == 0x0)
  37                         break;
  38                 buf[i + 2] = rate;
  39         }
  40         buf[1] = i;
  41
  42         return i + 2;
  43 }
  44
  45 static int prism_build_supp_rates(u8 *buf, const u8 *rates)
  46 {
  47         int i;
  48
  49         buf[0] = WLAN_EID_SUPP_RATES;
  50         for (i = 0; i < 8; i++) {
  51                 /* NULL terminated */
  52                 if (rates[i] == 0x0)
  53                         break;
  54                 buf[i + 2] = rates[i];
  55         }
  56         buf[1] = i;
  57
  58         /* We might still have another 2 rates, which need to go in
  59          * extended supported rates */
  60         if (i == 8 && rates[i] > 0) {
  61                 buf[10] = WLAN_EID_EXT_SUPP_RATES;
  62                 for (; i < 10; i++) {
  63                         /* NULL terminated */
  64                         if (rates[i] == 0x0)
  65                                 break;
  66                         buf[i + 2] = rates[i];
  67                 }
  68                 buf[11] = i - 8;
  69         }
  70
  71         return (i < 8) ? i + 2 : i + 4;
  72 }
  73
  74 static void orinoco_add_hostscan_result(struct orinoco_private *priv,
  75                                         const union hermes_scan_info *bss)
  76 {
  77         struct wiphy *wiphy = priv_to_wiphy(priv);
  78         struct ieee80211_channel *channel;
  79         u8 *ie;
  80         u8 ie_buf[46];
  81         u64 timestamp;
  82         s32 signal;
  83         u16 capability;
  84         u16 beacon_interval;
  85         int ie_len;
  86         int freq;
  87         int len;
  88
  89         len = le16_to_cpu(bss->a.essid_len);
  90
  91         /* Reconstruct SSID and bitrate IEs to pass up */
  92         ie_buf[0] = WLAN_EID_SSID;
  93         ie_buf[1] = len;
  94         memcpy(&ie_buf[2], bss->a.essid, len);
  95
  96         ie = ie_buf + len + 2;
  97         ie_len = ie_buf[1] + 2;
  98         switch (priv->firmware_type) {
  99         case FIRMWARE_TYPE_SYMBOL:
 100                 ie_len += symbol_build_supp_rates(ie, bss->s.rates);
 101                 break;
 102
 103         case FIRMWARE_TYPE_INTERSIL:
 104                 ie_len += prism_build_supp_rates(ie, bss->p.rates);
 105                 break;
 106
 107         case FIRMWARE_TYPE_AGERE:
 108         default:
 109                 break;
 110         }
 111
 112         freq = ieee80211_dsss_chan_to_freq(le16_to_cpu(bss->a.channel));
 113         channel = ieee80211_get_channel(wiphy, freq);
 114         timestamp = 0;
 115         capability = le16_to_cpu(bss->a.capabilities);
 116         beacon_interval = le16_to_cpu(bss->a.beacon_interv);
 117         signal = SIGNAL_TO_MBM(le16_to_cpu(bss->a.level));
 118
 119         cfg80211_inform_bss(wiphy, channel, bss->a.bssid, timestamp,
 120                             capability, beacon_interval, ie_buf, ie_len,
 121                             signal, GFP_KERNEL);
 122 }
 123
 124 void orinoco_add_extscan_result(struct orinoco_private *priv,
 125                                 struct agere_ext_scan_info *bss,
 126                                 size_t len)
 127 {
 128         struct wiphy *wiphy = priv_to_wiphy(priv);
 129         struct ieee80211_channel *channel;
 130         u8 *ie;
 131         u64 timestamp;
 132         s32 signal;
 133         u16 capability;
 134         u16 beacon_interval;
 135         size_t ie_len;
 136         int chan, freq;
 137
 138         ie_len = len - sizeof(*bss);
 139         ie = orinoco_get_ie(bss->data, ie_len, WLAN_EID_DS_PARAMS);
 140         chan = ie ? ie[2] : 0;
 141         freq = ieee80211_dsss_chan_to_freq(chan);
 142         channel = ieee80211_get_channel(wiphy, freq);
 143
 144         timestamp = le64_to_cpu(bss->timestamp);
 145         capability = le16_to_cpu(bss->capabilities);
 146         beacon_interval = le16_to_cpu(bss->beacon_interval);
 147         ie = bss->data;
 148         signal = SIGNAL_TO_MBM(bss->level);
 149
 150         cfg80211_inform_bss(wiphy, channel, bss->bssid, timestamp,
 151                             capability, beacon_interval, ie, ie_len,
 152                             signal, GFP_KERNEL);
 153 }
 154
 155 void orinoco_add_hostscan_results(struct orinoco_private *priv,
 156                                   unsigned char *buf,
 157                                   size_t len)
 158 {
 159         int offset;             /* In the scan data */
 160         size_t atom_len;
 161         bool abort = false;
 162
 163         switch (priv->firmware_type) {
 164         case FIRMWARE_TYPE_AGERE:
 165                 atom_len = sizeof(struct agere_scan_apinfo);
 166                 offset = 0;
 167                 break;
 168
 169         case FIRMWARE_TYPE_SYMBOL:
 170                 /* Lack of documentation necessitates this hack.
 171                  * Different firmwares have 68 or 76 byte long atoms.
 172                  * We try modulo first.  If the length divides by both,
 173                  * we check what would be the channel in the second
 174                  * frame for a 68-byte atom.  76-byte atoms have 0 there.
 175                  * Valid channel cannot be 0.  */
 176                 if (len % 76)
 177                         atom_len = 68;
 178                 else if (len % 68)
 179                         atom_len = 76;
 180                 else if (len >= 1292 && buf[68] == 0)
 181                         atom_len = 76;
 182                 else
 183                         atom_len = 68;
 184                 offset = 0;
 185                 break;
 186
 187         case FIRMWARE_TYPE_INTERSIL:
 188                 offset = 4;
 189                 if (priv->has_hostscan) {
 190                         atom_len = le16_to_cpup((__le16 *)buf);
 191                         /* Sanity check for atom_len */
 192                         if (atom_len < sizeof(struct prism2_scan_apinfo)) {
 193                                 printk(KERN_ERR "%s: Invalid atom_len in scan "
 194                                        "data: %zu\n", priv->ndev->name,
 195                                        atom_len);
 196                                 abort = true;
 197                                 goto scan_abort;
 198                         }
 199                 } else
 200                         atom_len = offsetof(struct prism2_scan_apinfo, atim);
 201                 break;
 202
 203         default:
 204                 abort = true;
 205                 goto scan_abort;
 206         }
 207
 208         /* Check that we got an whole number of atoms */
 209         if ((len - offset) % atom_len) {
 210                 printk(KERN_ERR "%s: Unexpected scan data length %zu, "
 211                        "atom_len %zu, offset %d\n", priv->ndev->name, len,
 212                        atom_len, offset);
 213                 abort = true;
 214                 goto scan_abort;
 215         }
 216
 217         /* Process the entries one by one */
 218         for (; offset + atom_len <= len; offset += atom_len) {
 219                 union hermes_scan_info *atom;
 220
 221                 atom = (union hermes_scan_info *) (buf + offset);
 222
 223                 orinoco_add_hostscan_result(priv, atom);
 224         }
 225
 226  scan_abort:
 227         if (priv->scan_request) {
 228                 cfg80211_scan_done(priv->scan_request, abort);
 229                 priv->scan_request = NULL;
 230         }
 231 }