wl12xx: AP mode - support hidden SSID

If a hidden SSID is requested, generate a probe response template
containing the real SSID.

Depends on the patch "mac80211: add ssid config to bss information
in AP-mode".

Signed-off-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>
diff --git a/drivers/net/wireless/wl12xx/main.c b/drivers/net/wireless/wl12xx/main.c
index 62118b7..02b5c00 100644
--- a/drivers/net/wireless/wl12xx/main.c
+++ b/drivers/net/wireless/wl12xx/main.c
@@ -3102,6 +3102,62 @@
 	skb_trim(skb, skb->len - len);
 }
 
+static int wl1271_ap_set_probe_resp_tmpl(struct wl1271 *wl,
+					 u8 *probe_rsp_data,
+					 size_t probe_rsp_len,
+					 u32 rates)
+{
+	struct ieee80211_bss_conf *bss_conf = &wl->vif->bss_conf;
+	u8 probe_rsp_templ[WL1271_CMD_TEMPL_MAX_SIZE];
+	int ssid_ie_offset, ie_offset, templ_len;
+	const u8 *ptr;
+
+	/* no need to change probe response if the SSID is set correctly */
+	if (wl->ssid_len > 0)
+		return wl1271_cmd_template_set(wl,
+					       CMD_TEMPL_AP_PROBE_RESPONSE,
+					       probe_rsp_data,
+					       probe_rsp_len, 0,
+					       rates);
+
+	if (probe_rsp_len + bss_conf->ssid_len > WL1271_CMD_TEMPL_MAX_SIZE) {
+		wl1271_error("probe_rsp template too big");
+		return -EINVAL;
+	}
+
+	/* start searching from IE offset */
+	ie_offset = offsetof(struct ieee80211_mgmt, u.probe_resp.variable);
+
+	ptr = cfg80211_find_ie(WLAN_EID_SSID, probe_rsp_data + ie_offset,
+			       probe_rsp_len - ie_offset);
+	if (!ptr) {
+		wl1271_error("No SSID in beacon!");
+		return -EINVAL;
+	}
+
+	ssid_ie_offset = ptr - probe_rsp_data;
+	ptr += (ptr[1] + 2);
+
+	memcpy(probe_rsp_templ, probe_rsp_data, ssid_ie_offset);
+
+	/* insert SSID from bss_conf */
+	probe_rsp_templ[ssid_ie_offset] = WLAN_EID_SSID;
+	probe_rsp_templ[ssid_ie_offset + 1] = bss_conf->ssid_len;
+	memcpy(probe_rsp_templ + ssid_ie_offset + 2,
+	       bss_conf->ssid, bss_conf->ssid_len);
+	templ_len = ssid_ie_offset + 2 + bss_conf->ssid_len;
+
+	memcpy(probe_rsp_templ + ssid_ie_offset + 2 + bss_conf->ssid_len,
+	       ptr, probe_rsp_len - (ptr - probe_rsp_data));
+	templ_len += probe_rsp_len - (ptr - probe_rsp_data);
+
+	return wl1271_cmd_template_set(wl,
+				       CMD_TEMPL_AP_PROBE_RESPONSE,
+				       probe_rsp_templ,
+				       templ_len, 0,
+				       rates);
+}
+
 static int wl1271_bss_erp_info_changed(struct wl1271 *wl,
 				       struct ieee80211_bss_conf *bss_conf,
 				       u32 changed)
@@ -3201,14 +3257,17 @@
 		hdr = (struct ieee80211_hdr *) beacon->data;
 		hdr->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
 						 IEEE80211_STYPE_PROBE_RESP);
-
-		tmpl_id = is_ap ? CMD_TEMPL_AP_PROBE_RESPONSE :
-				  CMD_TEMPL_PROBE_RESPONSE;
-		ret = wl1271_cmd_template_set(wl,
-					      tmpl_id,
-					      beacon->data,
-					      beacon->len, 0,
-					      wl1271_tx_min_rate_get(wl));
+		if (is_ap)
+			ret = wl1271_ap_set_probe_resp_tmpl(wl,
+						beacon->data,
+						beacon->len,
+						wl1271_tx_min_rate_get(wl));
+		else
+			ret = wl1271_cmd_template_set(wl,
+						CMD_TEMPL_PROBE_RESPONSE,
+						beacon->data,
+						beacon->len, 0,
+						wl1271_tx_min_rate_get(wl));
 		dev_kfree_skb(beacon);
 		if (ret < 0)
 			goto out;