iw: add country IE parsing

Spits out the channels as seen on the IE, useful when debugging
issues with APs. When found the equivalent distance of the
coverage class is printed out.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>

diff --git a/scan.c b/scan.c
index ec63e61691b09a3a0cee448c74e639fb5252ba8e..3253d9b85f4b6c217ebb4e71bfc5b91592b65d4f 100644 (file)
--- a/scan.c
+++ b/scan.c
@@ -36,6 +36,23 @@ struct scan_params {
        bool show_both_ie_sets;
 };
 
+#define IEEE80211_COUNTRY_EXTENSION_ID 201
+
+struct ieee80211_country_ie_triplet {
+       union {
+               struct {
+                       __u8 first_channel;
+                       __u8 num_channels;
+                       __s8 max_power;
+               } __attribute__ ((packed)) chans;
+               struct {
+                       __u8 reg_extension_id;
+                       __u8 reg_class;
+                       __u8 coverage_class;
+               } __attribute__ ((packed)) ext;
+       };
+} __attribute__ ((packed));
+
 static int handle_scan(struct nl80211_state *state,
                       struct nl_cb *cb,
                       struct nl_msg *msg,
@@ -143,29 +160,64 @@ static void print_ds(const uint8_t type, uint8_t len, const uint8_t *data)
        printf(" channel %d\n", data[0]);
 }
 
-static void print_country(const uint8_t type, uint8_t len, const uint8_t *data)
+static const char *country_env_str(char environment)
 {
-       int i;
-
-       printf(" %.*s", 2, data);
-       switch (data[2]) {
+       switch (environment) {
        case 'I':
-               printf(" (indoor)");
-               break;
+               return "Indoor only";
        case 'O':
-               printf(" (outdoor)");
-               break;
+               return "Outdoor only";
        case ' ':
-               printf(" (in/outdoor)");
-               break;
+               return "Indoor/Outdoor";
        default:
-               printf(" (invalid environment)");
-               break;
+               return "bogus";
        }
-       printf(", data:");
-       for(i=0; i<len-3; i++)
-               printf(" %.02x", data[i + 3]);
-       printf("\n");
+}
+
+static void print_country(const uint8_t type, uint8_t len, const uint8_t *data)
+{
+       printf(" %.*s", 2, data);
+
+       printf("\tEnvironment: %s\n", country_env_str(data[2]));
+
+       data += 3;
+       len -= 3;
+
+       if (len < 3) {
+               printf("\t\tNo country IE triplets present\n");
+               return;
+       }
+
+       while (len >= 3) {
+               int end_channel;
+               struct ieee80211_country_ie_triplet *triplet =
+                       (struct ieee80211_country_ie_triplet *) data;
+
+               if (triplet->ext.reg_extension_id >= IEEE80211_COUNTRY_EXTENSION_ID) {
+                       printf("\t\tExtension ID: %d Regulatory Class: %d Coverage class: %d (up to %dm)\n",
+                              triplet->ext.reg_extension_id,
+                              triplet->ext.reg_class,
+                              triplet->ext.coverage_class,
+                              triplet->ext.coverage_class * 450);
+
+                       data += 3;
+                       len -= 3;
+                       continue;
+               }
+
+               /* 2 GHz */
+               if (triplet->chans.first_channel <= 14)
+                       end_channel = triplet->chans.first_channel + (triplet->chans.num_channels - 1);
+               else
+                       end_channel =  triplet->chans.first_channel + (4 * (triplet->chans.num_channels - 1));
+
+               printf("\t\tChannels [%d - %d]\n", triplet->chans.first_channel, end_channel);
+
+               data += 3;
+               len -= 3;
+       }
+
+       return;
 }
 
 static void print_powerconstraint(const uint8_t type, uint8_t len, const uint8_t *data)