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
  23 /* get the TFS IE from driver */
  24 static int ieee80211_11_get_tfs_ie(struct hostapd_data *hapd, const u8 *addr,
  25                                    u8 *buf, u16 *buf_len, enum wnm_oper oper)
  26 {
  27         wpa_printf(MSG_DEBUG, "%s: TFS get operation %d", __func__, oper);
  28
  29         return hostapd_drv_wnm_oper(hapd, oper, addr, buf, buf_len);
  30 }
  31
  32
  33 /* set the TFS IE to driver */
  34 static int ieee80211_11_set_tfs_ie(struct hostapd_data *hapd, const u8 *addr,
  35                                    u8 *buf, u16 *buf_len, enum wnm_oper oper)
  36 {
  37         wpa_printf(MSG_DEBUG, "%s: TFS set operation %d", __func__, oper);
  38
  39         return hostapd_drv_wnm_oper(hapd, oper, addr, buf, buf_len);
  40 }
  41
  42
  43 /* MLME-SLEEPMODE.response */
  44 static int ieee802_11_send_wnmsleep_resp(struct hostapd_data *hapd,
  45                                          const u8 *addr, u8 dialog_token,
  46                                          u8 action_type, u16 intval)
  47 {
  48         struct ieee80211_mgmt *mgmt;
  49         int res;
  50         size_t len;
  51         size_t gtk_elem_len = 0;
  52         size_t igtk_elem_len = 0;
  53         struct wnm_sleep_element wnmsleep_ie;
  54         u8 *wnmtfs_ie;
  55         u8 wnmsleep_ie_len;
  56         u16 wnmtfs_ie_len;
  57         u8 *pos;
  58         struct sta_info *sta;
  59         enum wnm_oper tfs_oper = action_type == 0 ? WNM_SLEEP_TFS_RESP_IE_ADD :
  60                 WNM_SLEEP_TFS_RESP_IE_NONE;
  61
  62         sta = ap_get_sta(hapd, addr);
  63         if (sta == NULL) {
  64                 wpa_printf(MSG_DEBUG, "%s: station not found", __func__);
  65                 return -EINVAL;
  66         }
  67
  68         /* WNM-Sleep Mode IE */
  69         os_memset(&wnmsleep_ie, 0, sizeof(struct wnm_sleep_element));
  70         wnmsleep_ie_len = sizeof(struct wnm_sleep_element);
  71         wnmsleep_ie.eid = WLAN_EID_WNMSLEEP;
  72         wnmsleep_ie.len = wnmsleep_ie_len - 2;
  73         wnmsleep_ie.action_type = action_type;
  74         wnmsleep_ie.status = WNM_STATUS_SLEEP_ACCEPT;
  75         wnmsleep_ie.intval = intval;
  76
  77         /* TFS IE(s) */
  78         wnmtfs_ie = os_zalloc(MAX_TFS_IE_LEN);
  79         if (wnmtfs_ie == NULL)
  80                 return -1;
  81         if (ieee80211_11_get_tfs_ie(hapd, addr, wnmtfs_ie, &wnmtfs_ie_len,
  82                                     tfs_oper)) {
  83                 wnmtfs_ie_len = 0;
  84                 os_free(wnmtfs_ie);
  85                 wnmtfs_ie = NULL;
  86         }
  87
  88 #define MAX_GTK_SUBELEM_LEN 45
  89 #define MAX_IGTK_SUBELEM_LEN 26
  90         mgmt = os_zalloc(sizeof(*mgmt) + wnmsleep_ie_len +
  91                          MAX_GTK_SUBELEM_LEN + MAX_IGTK_SUBELEM_LEN);
  92         if (mgmt == NULL) {
  93                 wpa_printf(MSG_DEBUG, "MLME: Failed to allocate buffer for "
  94                            "WNM-Sleep Response action frame");
  95                 return -1;
  96         }
  97         os_memcpy(mgmt->da, addr, ETH_ALEN);
  98         os_memcpy(mgmt->sa, hapd->own_addr, ETH_ALEN);
  99         os_memcpy(mgmt->bssid, hapd->own_addr, ETH_ALEN);
 100         mgmt->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT,
 101                                            WLAN_FC_STYPE_ACTION);
 102         mgmt->u.action.category = WLAN_ACTION_WNM;
 103         mgmt->u.action.u.wnm_sleep_resp.action = WNM_SLEEP_MODE_RESP;
 104         mgmt->u.action.u.wnm_sleep_resp.dialogtoken = dialog_token;
 105         pos = (u8 *)mgmt->u.action.u.wnm_sleep_resp.variable;
 106         /* add key data if MFP is enabled */
 107         if (wpa_auth_uses_mfp(sta->wpa_sm) || action_type != 1){
 108                 mgmt->u.action.u.wnm_sleep_resp.keydata_len = 0;
 109         } else {
 110                 gtk_elem_len = wpa_wnmsleep_gtk_subelem(sta->wpa_sm, pos);
 111                 pos += gtk_elem_len;
 112                 wpa_printf(MSG_DEBUG, "Pass 4, gtk_len = %d",
 113                            (int) gtk_elem_len);
 114 #ifdef CONFIG_IEEE80211W
 115                 res = wpa_wnmsleep_igtk_subelem(sta->wpa_sm, pos);
 116                 if (res < 0) {
 117                         os_free(wnmtfs_ie);
 118                         os_free(mgmt);
 119                         return -1;
 120                 }
 121                 igtk_elem_len = res;
 122                 pos += igtk_elem_len;
 123                 wpa_printf(MSG_DEBUG, "Pass 4 igtk_len = %d",
 124                            (int) igtk_elem_len);
 125 #endif /* CONFIG_IEEE80211W */
 126
 127                 WPA_PUT_LE16((u8 *)
 128                              &mgmt->u.action.u.wnm_sleep_resp.keydata_len,
 129                              gtk_elem_len + igtk_elem_len);
 130         }
 131         os_memcpy(pos, &wnmsleep_ie, wnmsleep_ie_len);
 132         /* copy TFS IE here */
 133         pos += wnmsleep_ie_len;
 134         os_memcpy(pos, wnmtfs_ie, wnmtfs_ie_len);
 135
 136         len = 1 + sizeof(mgmt->u.action.u.wnm_sleep_resp) + gtk_elem_len +
 137                 igtk_elem_len + wnmsleep_ie_len + wnmtfs_ie_len;
 138
 139         /* In driver, response frame should be forced to sent when STA is in
 140          * PS mode */
 141         res = hostapd_drv_send_action(hapd, hapd->iface->freq, 0,
 142                                       mgmt->da, &mgmt->u.action.category, len);
 143
 144         if (!res) {
 145                 wpa_printf(MSG_DEBUG, "Successfully send WNM-Sleep Response "
 146                            "frame");
 147
 148                 /* when entering wnmsleep
 149                  * 1. pause the node in driver
 150                  * 2. mark the node so that AP won't update GTK/IGTK during
 151                  * WNM Sleep
 152                  */
 153                 if (wnmsleep_ie.status == WNM_STATUS_SLEEP_ACCEPT &&
 154                     wnmsleep_ie.action_type == 0) {
 155                         hostapd_drv_wnm_oper(hapd, WNM_SLEEP_ENTER_CONFIRM,
 156                                              addr, NULL, NULL);
 157                         wpa_set_wnmsleep(sta->wpa_sm, 1);
 158                 }
 159                 /* when exiting wnmsleep
 160                  * 1. unmark the node
 161                  * 2. start GTK/IGTK update if MFP is not used
 162                  * 3. unpause the node in driver
 163                  */
 164                 if (wnmsleep_ie.status == WNM_STATUS_SLEEP_ACCEPT &&
 165                     wnmsleep_ie.action_type == 1) {
 166                         wpa_set_wnmsleep(sta->wpa_sm, 0);
 167                         hostapd_drv_wnm_oper(hapd, WNM_SLEEP_EXIT_CONFIRM,
 168                                              addr, NULL, NULL);
 169                         if (wpa_auth_uses_mfp(sta->wpa_sm) && action_type == 1)
 170                                 wpa_wnmsleep_rekey_gtk(sta->wpa_sm);
 171                 }
 172         } else
 173                 wpa_printf(MSG_DEBUG, "Fail to send WNM-Sleep Response frame");
 174
 175 #undef MAX_GTK_SUBELEM_LEN
 176 #undef MAX_IGTK_SUBELEM_LEN
 177         os_free(wnmtfs_ie);
 178         os_free(mgmt);
 179         return res;
 180 }
 181
 182
 183 static void ieee802_11_rx_wnmsleep_req(struct hostapd_data *hapd,
 184                                        const u8 *addr, const u8 *frm, int len)
 185 {
 186         /* Dialog Token [1] | WNM-Sleep Mode IE | TFS Response IE */
 187         const u8 *pos = frm;
 188         u8 dialog_token;
 189         struct wnm_sleep_element *wnmsleep_ie = NULL;
 190         /* multiple TFS Req IE (assuming consecutive) */
 191         u8 *tfsreq_ie_start = NULL;
 192         u8 *tfsreq_ie_end = NULL;
 193         u16 tfsreq_ie_len = 0;
 194
 195         dialog_token = *pos++;
 196         while (pos + 1 < frm + len) {
 197                 u8 ie_len = pos[1];
 198                 if (pos + 2 + ie_len > frm + len)
 199                         break;
 200                 if (*pos == WLAN_EID_WNMSLEEP)
 201                         wnmsleep_ie = (struct wnm_sleep_element *) pos;
 202                 else if (*pos == WLAN_EID_TFS_REQ) {
 203                         if (!tfsreq_ie_start)
 204                                 tfsreq_ie_start = (u8 *) pos;
 205                         tfsreq_ie_end = (u8 *) pos;
 206                 } else
 207                         wpa_printf(MSG_DEBUG, "WNM: EID %d not recognized",
 208                                    *pos);
 209                 pos += ie_len + 2;
 210         }
 211
 212         if (!wnmsleep_ie) {
 213                 wpa_printf(MSG_DEBUG, "No WNM-Sleep IE found");
 214                 return;
 215         }
 216
 217         if (wnmsleep_ie->action_type == 0 && tfsreq_ie_start &&
 218             tfsreq_ie_end && tfsreq_ie_end - tfsreq_ie_start >= 0) {
 219                 tfsreq_ie_len = (tfsreq_ie_end + tfsreq_ie_end[1] + 2) -
 220                         tfsreq_ie_start;
 221                 wpa_printf(MSG_DEBUG, "TFS Req IE(s) found");
 222                 /* pass the TFS Req IE(s) to driver for processing */
 223                 if (ieee80211_11_set_tfs_ie(hapd, addr, tfsreq_ie_start,
 224                                             &tfsreq_ie_len,
 225                                             WNM_SLEEP_TFS_REQ_IE_SET))
 226                         wpa_printf(MSG_DEBUG, "Fail to set TFS Req IE");
 227         }
 228
 229         ieee802_11_send_wnmsleep_resp(hapd, addr, dialog_token,
 230                                       wnmsleep_ie->action_type,
 231                                       wnmsleep_ie->intval);
 232
 233         if (wnmsleep_ie->action_type == 1) {
 234                 /* clear the tfs after sending the resp frame */
 235                 ieee80211_11_set_tfs_ie(hapd, addr, tfsreq_ie_start,
 236                                         &tfsreq_ie_len, WNM_SLEEP_TFS_IE_DEL);
 237         }
 238 }
 239
 240
 241 int ieee802_11_rx_wnm_action_ap(struct hostapd_data *hapd,
 242                                 struct rx_action *action)
 243 {
 244         if (action->len < 1 || action->data == NULL)
 245                 return -1;
 246
 247         switch (action->data[0]) {
 248         case WNM_SLEEP_MODE_REQ:
 249                 ieee802_11_rx_wnmsleep_req(hapd, action->sa, action->data + 1,
 250                                            action->len - 1);
 251                 return 0;
 252         }
 253
 254         wpa_printf(MSG_DEBUG, "WNM: Unsupported WNM Action %u from " MACSTR,
 255                    action->data[0], MAC2STR(action->sa));
 256         return -1;
 257 }