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>

2 files changed, 82 insertions, 17 deletions

diff --git a/drivers/net/wireless/wl12xx/cmd.c b/drivers/net/wireless/wl12xx/cmd.c
index 084262f169b2..51be8f7fbb88 100644
--- a/drivers/net/wireless/wl12xx/cmd.c
+++ b/drivers/net/wireless/wl12xx/cmd.c
@@ -661,12 +661,9 @@ int wl12xx_cmd_role_start_ap(struct wl1271 *wl)
 
         wl1271_debug(DEBUG_CMD, "cmd role start ap %d", wl->role_id);
 
-        /*
-         * We currently do not support hidden SSID. The real SSID
-         * should be fetched from mac80211 first.
-         */
-        if (wl->ssid_len == 0) {
-                wl1271_warning("Hidden SSID currently not supported for AP");
+        /* trying to use hidden SSID with an old hostapd version */
+        if (wl->ssid_len == 0 && !bss_conf->hidden_ssid) {
+                wl1271_error("got a null SSID from beacon/bss");
                 ret = -EINVAL;
                 goto out;
         }
@@ -695,9 +692,18 @@ int wl12xx_cmd_role_start_ap(struct wl1271 *wl)
         cmd->ap.dtim_interval = bss_conf->dtim_period;
         cmd->ap.beacon_expiry = WL1271_AP_DEF_BEACON_EXP;
         cmd->channel = wl->channel;
-        cmd->ap.ssid_len = wl->ssid_len;
-        cmd->ap.ssid_type = WL12XX_SSID_TYPE_PUBLIC;
-        memcpy(cmd->ap.ssid, wl->ssid, wl->ssid_len);
+
+        if (!bss_conf->hidden_ssid) {
+                /* take the SSID from the beacon for backward compatibility */
+                cmd->ap.ssid_type = WL12XX_SSID_TYPE_PUBLIC;
+                cmd->ap.ssid_len = wl->ssid_len;
+                memcpy(cmd->ap.ssid, wl->ssid, wl->ssid_len);
+        } else {
+                cmd->ap.ssid_type = WL12XX_SSID_TYPE_HIDDEN;
+                cmd->ap.ssid_len = bss_conf->ssid_len;
+                memcpy(cmd->ap.ssid, bss_conf->ssid, bss_conf->ssid_len);
+        }
+
         cmd->ap.local_rates = cpu_to_le32(0xffffffff);
 
         switch (wl->band) {
diff --git a/drivers/net/wireless/wl12xx/main.c b/drivers/net/wireless/wl12xx/main.c
index 62118b7988bd..02b5c007d1bf 100644
--- a/drivers/net/wireless/wl12xx/main.c
+++ b/drivers/net/wireless/wl12xx/main.c
@@ -3102,6 +3102,62 @@ static void wl12xx_remove_vendor_ie(struct sk_buff *skb,
         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 @@ static int wl1271_bss_beacon_info_changed(struct wl1271 *wl,
                 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;