Fix various issues with wireless information under FreeBSD:

- Instead of hoping that the currently associated AP will show up as
  the first AP in the list of scan results, fetch the BSSID of the
  currently associated AP and use that to fetch station info for the
  AP.  This provides more frequently updated signal strength
  information than scan results and reliably provides information when
  multiple APs are in range.
- Do not treat the RSSI value as a raw signal value in dBm.  Instead, use
  the same formula as ifconfig(8) to compute a signal value.
- Do not report the beacon interval value as a signal quality level.

1 files changed, 30 insertions, 19 deletions

diff --git a/src/print_wireless_info.c b/src/print_wireless_info.c
index 83c717e..99b07f8 100644
--- a/src/print_wireless_info.c
+++ b/src/print_wireless_info.c
@@ -197,10 +197,14 @@ static int get_wireless_info(const char *interface, wireless_info_t *info) {
     return 1;
 #endif
 #if defined(__FreeBSD__) || defined(__DragonFly__)
-    int s, len, inwid;
-    uint8_t buf[24 * 1024], *cp;
+    int s, inwid;
+    union {
+        struct ieee80211req_sta_req req;
+        uint8_t buf[24 * 1024];
+    } u;
     struct ieee80211req na;
-    char network_id[IEEE80211_NWID_LEN + 1];
+    char bssid[IEEE80211_ADDR_LEN];
+    size_t len;
 
     if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
         return (0);
@@ -228,31 +232,38 @@ static int get_wireless_info(const char *interface, wireless_info_t *info) {
 
     memset(&na, 0, sizeof(na));
     strlcpy(na.i_name, interface, sizeof(na.i_name));
-    na.i_type = IEEE80211_IOC_SCAN_RESULTS;
-    na.i_data = buf;
-    na.i_len = sizeof(buf);
+    na.i_type = IEEE80211_IOC_BSSID;
+    na.i_data = bssid;
+    na.i_len = sizeof(bssid);
+
+    if (ioctl(s, SIOCG80211, (caddr_t)&na) == -1) {
+        close(s);
+        return (0);
+    }
+
+    memcpy(u.req.is_u.macaddr, bssid, sizeof(bssid));
+    memset(&na, 0, sizeof(na));
+    strlcpy(na.i_name, interface, sizeof(na.i_name));
+    na.i_type = IEEE80211_IOC_STA_INFO;
+    na.i_data = &u;
+    na.i_len = sizeof(u);
 
     if (ioctl(s, SIOCG80211, (caddr_t)&na) == -1) {
-        printf("fail\n");
         close(s);
         return (0);
     }
 
     close(s);
-    len = na.i_len;
-    cp = buf;
-    struct ieee80211req_scan_result *sr;
-    uint8_t *vp;
-    sr = (struct ieee80211req_scan_result *)cp;
-    vp = (u_int8_t *)(sr + 1);
-    strlcpy(network_id, (const char *)vp, sr->isr_ssid_len + 1);
-    if (!strcmp(network_id, &info->essid[0])) {
-        info->signal_level = sr->isr_rssi;
+    if (na.i_len >= sizeof(u.req)) {
+        /*
+	 * Just use the first BSSID returned even if there are
+	 * multiple APs sharing the same BSSID.
+	 */
+        info->signal_level = u.req.info[0].isi_rssi / 2 +
+                             u.req.info[0].isi_noise;
         info->flags |= WIRELESS_INFO_FLAG_HAS_SIGNAL;
-        info->noise_level = sr->isr_noise;
+        info->noise_level = u.req.info[0].isi_noise;
         info->flags |= WIRELESS_INFO_FLAG_HAS_NOISE;
-        info->quality = sr->isr_intval;
-        info->flags |= WIRELESS_INFO_FLAG_HAS_QUALITY;
     }
 
     return 1;