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      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 */
    259