WNM: Minimal processing of BSS Transition Management Query/Response

This adds first steps at processing a BSS Transition Management Query on
the AP side. Mainly, the message is parsed and printed out in the debug
log and a minimal BSS Transition Management Request frame is sent as a
response. BSS Transition Management Response frame is also parsed and
details printed out in the debug log.

Signed-hostap: Jouni Malinen <j@w1.fi>

diff --git a/src/ap/wnm_ap.c b/src/ap/wnm_ap.c
index 54a6b857d7845a94bd31c38b086d1a1affded890..225fe0201b69d271769ae3904315a162a9b1a712 100644 (file)
--- a/src/ap/wnm_ap.c
+++ b/src/ap/wnm_ap.c
@@ -243,6 +243,126 @@ static void ieee802_11_rx_wnmsleep_req(struct hostapd_data *hapd,
 }
 
 
+static int ieee802_11_send_bss_trans_mgmt_request(struct hostapd_data *hapd,
+                                                 const u8 *addr,
+                                                 u8 dialog_token,
+                                                 const char *url)
+{
+       struct ieee80211_mgmt *mgmt;
+       size_t url_len, len;
+       u8 *pos;
+       int res;
+
+       if (url)
+               url_len = os_strlen(url);
+       else
+               url_len = 0;
+
+       mgmt = os_zalloc(sizeof(*mgmt) + (url_len ? 1 + url_len : 0));
+       if (mgmt == NULL)
+               return -1;
+       os_memcpy(mgmt->da, addr, ETH_ALEN);
+       os_memcpy(mgmt->sa, hapd->own_addr, ETH_ALEN);
+       os_memcpy(mgmt->bssid, hapd->own_addr, ETH_ALEN);
+       mgmt->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT,
+                                          WLAN_FC_STYPE_ACTION);
+       mgmt->u.action.category = WLAN_ACTION_WNM;
+       mgmt->u.action.u.bss_tm_req.action = WNM_BSS_TRANS_MGMT_REQ;
+       mgmt->u.action.u.bss_tm_req.dialog_token = dialog_token;
+       mgmt->u.action.u.bss_tm_req.req_mode = 0;
+       mgmt->u.action.u.bss_tm_req.disassoc_timer = host_to_le16(0);
+       mgmt->u.action.u.bss_tm_req.validity_interval = 1;
+       pos = mgmt->u.action.u.bss_tm_req.variable;
+       if (url) {
+               *pos++ += url_len;
+               os_memcpy(pos, url, url_len);
+               pos += url_len;
+       }
+
+       wpa_printf(MSG_DEBUG, "WNM: Send BSS Transition Management Request to "
+                  MACSTR " dialog_token=%u req_mode=0x%x disassoc_timer=%u "
+                  "validity_interval=%u",
+                  MAC2STR(addr), dialog_token,
+                  mgmt->u.action.u.bss_tm_req.req_mode,
+                  le_to_host16(mgmt->u.action.u.bss_tm_req.disassoc_timer),
+                  mgmt->u.action.u.bss_tm_req.validity_interval);
+
+       len = pos - &mgmt->u.action.category;
+       res = hostapd_drv_send_action(hapd, hapd->iface->freq, 0,
+                                     mgmt->da, &mgmt->u.action.category, len);
+       os_free(mgmt);
+       return res;
+}
+
+
+static void ieee802_11_rx_bss_trans_mgmt_query(struct hostapd_data *hapd,
+                                              const u8 *addr, const u8 *frm,
+                                              size_t len)
+{
+       u8 dialog_token, reason;
+       const u8 *pos, *end;
+
+       if (len < 2) {
+               wpa_printf(MSG_DEBUG, "WNM: Ignore too short BSS Transition Management Query from "
+                          MACSTR, MAC2STR(addr));
+               return;
+       }
+
+       pos = frm;
+       end = pos + len;
+       dialog_token = *pos++;
+       reason = *pos++;
+
+       wpa_printf(MSG_DEBUG, "WNM: BSS Transition Management Query from "
+                  MACSTR " dialog_token=%u reason=%u",
+                  MAC2STR(addr), dialog_token, reason);
+
+       wpa_hexdump(MSG_DEBUG, "WNM: BSS Transition Candidate List Entries",
+                   pos, end - pos);
+
+       ieee802_11_send_bss_trans_mgmt_request(hapd, addr, dialog_token, NULL);
+}
+
+
+static void ieee802_11_rx_bss_trans_mgmt_resp(struct hostapd_data *hapd,
+                                             const u8 *addr, const u8 *frm,
+                                             size_t len)
+{
+       u8 dialog_token, status_code, bss_termination_delay;
+       const u8 *pos, *end;
+
+       if (len < 3) {
+               wpa_printf(MSG_DEBUG, "WNM: Ignore too short BSS Transition Management Response from "
+                          MACSTR, MAC2STR(addr));
+               return;
+       }
+
+       pos = frm;
+       end = pos + len;
+       dialog_token = *pos++;
+       status_code = *pos++;
+       bss_termination_delay = *pos++;
+
+       wpa_printf(MSG_DEBUG, "WNM: BSS Transition Management Response from "
+                  MACSTR " dialog_token=%u status_code=%u "
+                  "bss_termination_delay=%u", MAC2STR(addr), dialog_token,
+                  status_code, bss_termination_delay);
+
+       if (status_code == WNM_BSS_TM_ACCEPT) {
+               if (end - pos < ETH_ALEN) {
+                       wpa_printf(MSG_DEBUG, "WNM: not enough room for Target BSSID field");
+                       return;
+               }
+               wpa_printf(MSG_DEBUG, "WNM: Target BSSID: " MACSTR,
+                          MAC2STR(pos));
+               pos += ETH_ALEN;
+       }
+
+       wpa_hexdump(MSG_DEBUG, "WNM: BSS Transition Candidate List Entries",
+                   pos, end - pos);
+}
+
+
 int ieee802_11_rx_wnm_action_ap(struct hostapd_data *hapd,
                                struct rx_action *action)
 {
@@ -251,14 +371,15 @@ int ieee802_11_rx_wnm_action_ap(struct hostapd_data *hapd,
 
        switch (action->data[0]) {
        case WNM_BSS_TRANS_MGMT_QUERY:
-               wpa_printf(MSG_DEBUG, "WNM: BSS Transition Management Query");
-               /* TODO */
-               return -1;
+               ieee802_11_rx_bss_trans_mgmt_query(hapd, action->sa,
+                                                  action->data + 1,
+                                                  action->len - 1);
+               return 0;
        case WNM_BSS_TRANS_MGMT_RESP:
-               wpa_printf(MSG_DEBUG, "WNM: BSS Transition Management "
-                          "Response");
-               /* TODO */
-               return -1;
+               ieee802_11_rx_bss_trans_mgmt_resp(hapd, action->sa,
+                                                 action->data + 1,
+                                                 action->len - 1);
+               return 0;
        case WNM_SLEEP_MODE_REQ:
                ieee802_11_rx_wnmsleep_req(hapd, action->sa, action->data + 1,
                                           action->len - 1);