+static bool is_band_valid(struct wiphy *wiphy, enum nl80211_band b)
+{
+ return b < NUM_NL80211_BANDS && wiphy->bands[b];
+}
+
+static int parse_bss_select(struct nlattr *nla, struct wiphy *wiphy,
+ struct cfg80211_bss_selection *bss_select)
+{
+ struct nlattr *attr[NL80211_BSS_SELECT_ATTR_MAX + 1];
+ struct nlattr *nest;
+ int err;
+ bool found = false;
+ int i;
+
+ /* only process one nested attribute */
+ nest = nla_data(nla);
+ if (!nla_ok(nest, nla_len(nest)))
+ return -EINVAL;
+
+ err = nla_parse(attr, NL80211_BSS_SELECT_ATTR_MAX, nla_data(nest),
+ nla_len(nest), nl80211_bss_select_policy);
+ if (err)
+ return err;
+
+ /* only one attribute may be given */
+ for (i = 0; i <= NL80211_BSS_SELECT_ATTR_MAX; i++) {
+ if (attr[i]) {
+ if (found)
+ return -EINVAL;
+ found = true;
+ }
+ }
+
+ bss_select->behaviour = __NL80211_BSS_SELECT_ATTR_INVALID;
+
+ if (attr[NL80211_BSS_SELECT_ATTR_RSSI])
+ bss_select->behaviour = NL80211_BSS_SELECT_ATTR_RSSI;
+
+ if (attr[NL80211_BSS_SELECT_ATTR_BAND_PREF]) {
+ bss_select->behaviour = NL80211_BSS_SELECT_ATTR_BAND_PREF;
+ bss_select->param.band_pref =
+ nla_get_u32(attr[NL80211_BSS_SELECT_ATTR_BAND_PREF]);
+ if (!is_band_valid(wiphy, bss_select->param.band_pref))
+ return -EINVAL;
+ }
+
+ if (attr[NL80211_BSS_SELECT_ATTR_RSSI_ADJUST]) {
+ struct nl80211_bss_select_rssi_adjust *adj_param;
+
+ adj_param = nla_data(attr[NL80211_BSS_SELECT_ATTR_RSSI_ADJUST]);
+ bss_select->behaviour = NL80211_BSS_SELECT_ATTR_RSSI_ADJUST;
+ bss_select->param.adjust.band = adj_param->band;
+ bss_select->param.adjust.delta = adj_param->delta;
+ if (!is_band_valid(wiphy, bss_select->param.adjust.band))
+ return -EINVAL;
+ }
+
+ /* user-space did not provide behaviour attribute */
+ if (bss_select->behaviour == __NL80211_BSS_SELECT_ATTR_INVALID)
+ return -EINVAL;
+
+ if (!(wiphy->bss_select_support & BIT(bss_select->behaviour)))
+ return -EINVAL;
+
+ return 0;
+}
+