src/ap/wnm_ap.c

   1 /*
   2  * hostapd - WNM
   3  * Copyright (c) 2011-2012, Qualcomm Atheros, Inc.
   4  *
   5  * This software may be distributed under the terms of the BSD license.
   6  * See README for more details.
   7  */
   8
   9 #include "utils/includes.h"
  10
  11 #include "utils/common.h"
  12 #include "common/ieee802_11_defs.h"
  13 #include "ap/hostapd.h"
  14 #include "ap/sta_info.h"
  15 #include "ap/ap_config.h"
  16 #include "ap/ap_drv_ops.h"
  17 #include "ap/wpa_auth.h"
  18 #include "wnm_ap.h"
  19
  20 #define MAX_TFS_IE_LEN  1024
  21
  22 #ifdef CONFIG_IEEE80211V
  23
  24 /* get the TFS IE from driver */
  25 static int ieee80211_11_get_tfs_ie(struct hostapd_data *hapd, const u8 *addr,
  26                                    u8 *buf, u16 *buf_len, enum wnm_oper oper)
  27 {
  28         wpa_printf(MSG_DEBUG, "%s: TFS get operation %d", __func__, oper);
  29
  30         return hostapd_drv_wnm_oper(hapd, oper, addr, buf, buf_len);
  31 }
  32
  33
  34 /* set the TFS IE to driver */
  35 static int ieee80211_11_set_tfs_ie(struct hostapd_data *hapd, const u8 *addr,
  36                                    u8 *buf, u16 *buf_len, enum wnm_oper oper)
  37 {
  38         wpa_printf(MSG_DEBUG, "%s: TFS set operation %d", __func__, oper);
  39
  40         return hostapd_drv_wnm_oper(hapd, oper, addr, buf, buf_len);
  41 }
  42
  43
  44 /* MLME-SLEEPMODE.response */
  45 static int ieee802_11_send_wnmsleep_resp(struct hostapd_data *hapd,
  46                                          const u8 *addr, u8 dialog_token,
  47                                          u8 action_type, u16 intval)
  48 {
  49         struct ieee80211_mgmt *mgmt;
  50         int res;
  51         size_t len;
  52         size_t gtk_elem_len = 0;
  53         size_t igtk_elem_len = 0;
  54         struct wnm_sleep_element wnmsleep_ie;
  55         u8 *wnmtfs_ie;
  56         u8 wnmsleep_ie_len;
  57         u16 wnmtfs_ie_len;
  58         u8 *pos;
  59         struct sta_info *sta;
  60         enum wnm_oper tfs_oper = action_type == 0 ? WNM_SLEEP_TFS_RESP_IE_ADD :
  61                 WNM_SLEEP_TFS_RESP_IE_NONE;
  62
  63         sta = ap_get_sta(hapd, addr);
  64         if (sta == NULL) {
  65                 wpa_printf(MSG_DEBUG, "%s: station not found", __func__);
  66                 return -EINVAL;
  67         }
  68
  69         /* WNM-Sleep Mode IE */
  70         os_memset(&wnmsleep_ie, 0, sizeof(struct wnm_sleep_element));
  71         wnmsleep_ie_len = sizeof(struct wnm_sleep_element);
  72         wnmsleep_ie.eid = WLAN_EID_WNMSLEEP;
  73         wnmsleep_ie.len = wnmsleep_ie_len - 2;
  74         wnmsleep_ie.action_type = action_type;
  75         wnmsleep_ie.status = WNM_STATUS_SLEEP_ACCEPT;
  76         wnmsleep_ie.intval = intval;
  77
  78         /* TFS IE(s) */
  79         wnmtfs_ie = os_zalloc(MAX_TFS_IE_LEN);
  80         if (wnmtfs_ie == NULL)
  81                 return -1;
  82         if (ieee80211_11_get_tfs_ie(hapd, addr, wnmtfs_ie, &wnmtfs_ie_len,
  83                                     tfs_oper)) {
  84                 wnmtfs_ie_len = 0;
  85                 os_free(wnmtfs_ie);
  86                 wnmtfs_ie = NULL;
  87         }
  88
  89 #define MAX_GTK_SUBELEM_LEN 45
  90 #define MAX_IGTK_SUBELEM_LEN 26
  91         mgmt = os_zalloc(sizeof(*mgmt) + wnmsleep_ie_len +
  92                          MAX_GTK_SUBELEM_LEN + MAX_IGTK_SUBELEM_LEN);
  93         if (mgmt == NULL) {
  94                 wpa_printf(MSG_DEBUG, "MLME: Failed to allocate buffer for "
  95                            "WNM-Sleep Response action frame");
  96                 return -1;
  97         }
  98         os_memcpy(mgmt->da, addr, ETH_ALEN);
  99         os_memcpy(mgmt->sa, hapd->own_addr, ETH_ALEN);
 100         os_memcpy(mgmt->bssid, hapd->own_addr, ETH_ALEN);
 101         mgmt->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT,
 102                                            WLAN_FC_STYPE_ACTION);
 103         mgmt->u.action.category = WLAN_ACTION_WNM;
 104         mgmt->u.action.u.wnm_sleep_resp.action = WNM_SLEEP_MODE_RESP;
 105         mgmt->u.action.u.wnm_sleep_resp.dialogtoken = dialog_token;
 106         pos = (u8 *)mgmt->u.action.u.wnm_sleep_resp.variable;
 107         /* add key data if MFP is enabled */
 108         if (wpa_auth_uses_mfp(sta->wpa_sm) || action_type != 1){
 109                 mgmt->u.action.u.wnm_sleep_resp.keydata_len = 0;
 110         } else {
 111                 gtk_elem_len = wpa_wnmsleep_gtk_subelem(sta->wpa_sm, pos);
 112                 pos += gtk_elem_len;
 113                 wpa_printf(MSG_DEBUG, "Pass 4, gtk_len = %d",
 114                            (int) gtk_elem_len);
 115 #ifdef CONFIG_IEEE80211W
 116                 res = wpa_wnmsleep_igtk_subelem(sta->wpa_sm, pos);
 117                 if (res < 0) {
 118                         os_free(wnmtfs_ie);
 119                         os_free(mgmt);
 120                         return -1;
 121                 }
 122                 igtk_elem_len = res;
 123                 pos += igtk_elem_len;
 124                 wpa_printf(MSG_DEBUG, "Pass 4 igtk_len = %d",
 125                            (int) igtk_elem_len);
 126 #endif /* CONFIG_IEEE80211W */
 127
 128                 WPA_PUT_LE16((u8 *)
 129                              &mgmt->u.action.u.wnm_sleep_resp.keydata_len,
 130                              gtk_elem_len + igtk_elem_len);
 131         }
 132         os_memcpy(pos, &wnmsleep_ie, wnmsleep_ie_len);
 133         /* copy TFS IE here */
 134         pos += wnmsleep_ie_len;
 135         os_memcpy(pos, wnmtfs_ie, wnmtfs_ie_len);
 136
 137         len = 1 + sizeof(mgmt->u.action.u.wnm_sleep_resp) + gtk_elem_len +
 138                 igtk_elem_len + wnmsleep_ie_len + wnmtfs_ie_len;
 139
 140         /* In driver, response frame should be forced to sent when STA is in
 141          * PS mode */
 142         res = hostapd_drv_send_action(hapd, hapd->iface->freq, 0,
 143                                       mgmt->da, &mgmt->u.action.category, len);
 144
 145         if (!res) {
 146                 wpa_printf(MSG_DEBUG, "Successfully send WNM-Sleep Response "
 147                            "frame");
 148
 149                 /* when entering wnmsleep
 150                  * 1. pause the node in driver
 151                  * 2. mark the node so that AP won't update GTK/IGTK during
 152                  * WNM Sleep
 153                  */
 154                 if (wnmsleep_ie.status == WNM_STATUS_SLEEP_ACCEPT &&
 155                     wnmsleep_ie.action_type == 0) {
 156                         hostapd_drv_wnm_oper(hapd, WNM_SLEEP_ENTER_CONFIRM,
 157                                              addr, NULL, NULL);
 158                         wpa_set_wnmsleep(sta->wpa_sm, 1);
 159                 }
 160                 /* when exiting wnmsleep
 161                  * 1. unmark the node
 162                  * 2. start GTK/IGTK update if MFP is not used
 163                  * 3. unpause the node in driver
 164                  */
 165                 if (wnmsleep_ie.status == WNM_STATUS_SLEEP_ACCEPT &&
 166                     wnmsleep_ie.action_type == 1) {
 167                         wpa_set_wnmsleep(sta->wpa_sm, 0);
 168                         hostapd_drv_wnm_oper(hapd, WNM_SLEEP_EXIT_CONFIRM,
 169                                              addr, NULL, NULL);
 170                         if (wpa_auth_uses_mfp(sta->wpa_sm) && action_type == 1)
 171                                 wpa_wnmsleep_rekey_gtk(sta->wpa_sm);
 172                 }
 173         } else
 174                 wpa_printf(MSG_DEBUG, "Fail to send WNM-Sleep Response frame");
 175
 176 #undef MAX_GTK_SUBELEM_LEN
 177 #undef MAX_IGTK_SUBELEM_LEN
 178         os_free(wnmtfs_ie);
 179         os_free(mgmt);
 180         return res;
 181 }
 182
 183
 184 static void ieee802_11_rx_wnmsleep_req(struct hostapd_data *hapd,
 185                                        const u8 *addr, const u8 *frm, int len)
 186 {
 187         /*
 188          * Action [1] | Dialog Token [1] | WNM-Sleep Mode IE |
 189          * TFS Response IE
 190          */
 191         u8 *pos = (u8 *) frm; /* point to action field */
 192         u8 dialog_token = pos[1];
 193         struct wnm_sleep_element *wnmsleep_ie = NULL;
 194         /* multiple TFS Req IE (assuming consecutive) */
 195         u8 *tfsreq_ie_start = NULL;
 196         u8 *tfsreq_ie_end = NULL;
 197         u16 tfsreq_ie_len = 0;
 198
 199         pos += 1 + 1;
 200         while (pos - frm < len - 1) {
 201                 u8 ie_len = *(pos+1);
 202                 if (*pos == WLAN_EID_WNMSLEEP)
 203                         wnmsleep_ie = (struct wnm_sleep_element *)pos;
 204                 else if (*pos == WLAN_EID_TFS_REQ) {
 205                         if (!tfsreq_ie_start)
 206                                 tfsreq_ie_start = pos;
 207                         tfsreq_ie_end = pos;
 208                 } else
 209                         wpa_printf(MSG_DEBUG, "EID %d not recognized", *pos);
 210                 pos += ie_len + 2;
 211         }
 212
 213         if (!wnmsleep_ie) {
 214                 wpa_printf(MSG_DEBUG, "No WNM-Sleep IE found");
 215                 return;
 216         }
 217
 218         if (wnmsleep_ie->action_type == 0 && tfsreq_ie_start &&
 219             tfsreq_ie_end && tfsreq_ie_end - tfsreq_ie_start >= 0) {
 220                 tfsreq_ie_len = (tfsreq_ie_end + tfsreq_ie_end[1] + 2) -
 221                         tfsreq_ie_start;
 222                 wpa_printf(MSG_DEBUG, "TFS Req IE(s) found");
 223                 /* pass the TFS Req IE(s) to driver for processing */
 224                 if (ieee80211_11_set_tfs_ie(hapd, addr, tfsreq_ie_start,
 225                                             &tfsreq_ie_len,
 226                                             WNM_SLEEP_TFS_REQ_IE_SET))
 227                         wpa_printf(MSG_DEBUG, "Fail to set TFS Req IE");
 228         }
 229
 230         ieee802_11_send_wnmsleep_resp(hapd, addr, dialog_token,
 231                                       wnmsleep_ie->action_type,
 232                                       wnmsleep_ie->intval);
 233
 234         if (wnmsleep_ie->action_type == 1) {
 235                 /* clear the tfs after sending the resp frame */
 236                 ieee80211_11_set_tfs_ie(hapd, addr, tfsreq_ie_start,
 237                                         &tfsreq_ie_len, WNM_SLEEP_TFS_IE_DEL);
 238         }
 239 }
 240
 241
 242 void ieee802_11_rx_wnm_action_ap(struct hostapd_data *hapd,
 243                                  struct rx_action *action)
 244 {
 245         u8 *pos = (u8 *) action->data + 1; /* point to the action field */
 246         u8 act = *pos;
 247
 248         switch (act) {
 249         case WNM_SLEEP_MODE_REQ:
 250                 ieee802_11_rx_wnmsleep_req(hapd, action->sa, action->data + 1,
 251                                            action->len);
 252                 break;
 253         default:
 254                 break;
 255         }
 256 }
 257
 258 #endif /* CONFIG_IEEE80211V */