Home | History | Annotate | Download | only in ap
      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 == WNM_SLEEP_MODE_ENTER ?
     60 		WNM_SLEEP_TFS_RESP_IE_ADD : 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) ||
    108 	    action_type != WNM_SLEEP_MODE_EXIT) {
    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 	if (wnmtfs_ie)
    136 		os_memcpy(pos, wnmtfs_ie, wnmtfs_ie_len);
    137 
    138 	len = 1 + sizeof(mgmt->u.action.u.wnm_sleep_resp) + gtk_elem_len +
    139 		igtk_elem_len + wnmsleep_ie_len + wnmtfs_ie_len;
    140 
    141 	/* In driver, response frame should be forced to sent when STA is in
    142 	 * PS mode */
    143 	res = hostapd_drv_send_action(hapd, hapd->iface->freq, 0,
    144 				      mgmt->da, &mgmt->u.action.category, len);
    145 
    146 	if (!res) {
    147 		wpa_printf(MSG_DEBUG, "Successfully send WNM-Sleep Response "
    148 			   "frame");
    149 
    150 		/* when entering wnmsleep
    151 		 * 1. pause the node in driver
    152 		 * 2. mark the node so that AP won't update GTK/IGTK during
    153 		 * WNM Sleep
    154 		 */
    155 		if (wnmsleep_ie.status == WNM_STATUS_SLEEP_ACCEPT &&
    156 		    wnmsleep_ie.action_type == WNM_SLEEP_MODE_ENTER) {
    157 			hostapd_drv_wnm_oper(hapd, WNM_SLEEP_ENTER_CONFIRM,
    158 					     addr, NULL, NULL);
    159 			wpa_set_wnmsleep(sta->wpa_sm, 1);
    160 		}
    161 		/* when exiting wnmsleep
    162 		 * 1. unmark the node
    163 		 * 2. start GTK/IGTK update if MFP is not used
    164 		 * 3. unpause the node in driver
    165 		 */
    166 		if ((wnmsleep_ie.status == WNM_STATUS_SLEEP_ACCEPT ||
    167 		     wnmsleep_ie.status ==
    168 		     WNM_STATUS_SLEEP_EXIT_ACCEPT_GTK_UPDATE) &&
    169 		    wnmsleep_ie.action_type == WNM_SLEEP_MODE_EXIT) {
    170 			wpa_set_wnmsleep(sta->wpa_sm, 0);
    171 			hostapd_drv_wnm_oper(hapd, WNM_SLEEP_EXIT_CONFIRM,
    172 					     addr, NULL, NULL);
    173 			if (!wpa_auth_uses_mfp(sta->wpa_sm))
    174 				wpa_wnmsleep_rekey_gtk(sta->wpa_sm);
    175 		}
    176 	} else
    177 		wpa_printf(MSG_DEBUG, "Fail to send WNM-Sleep Response frame");
    178 
    179 #undef MAX_GTK_SUBELEM_LEN
    180 #undef MAX_IGTK_SUBELEM_LEN
    181 	os_free(wnmtfs_ie);
    182 	os_free(mgmt);
    183 	return res;
    184 }
    185 
    186 
    187 static void ieee802_11_rx_wnmsleep_req(struct hostapd_data *hapd,
    188 				       const u8 *addr, const u8 *frm, int len)
    189 {
    190 	/* Dialog Token [1] | WNM-Sleep Mode IE | TFS Response IE */
    191 	const u8 *pos = frm;
    192 	u8 dialog_token;
    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 	dialog_token = *pos++;
    200 	while (pos + 1 < frm + len) {
    201 		u8 ie_len = pos[1];
    202 		if (pos + 2 + ie_len > frm + len)
    203 			break;
    204 		if (*pos == WLAN_EID_WNMSLEEP)
    205 			wnmsleep_ie = (struct wnm_sleep_element *) pos;
    206 		else if (*pos == WLAN_EID_TFS_REQ) {
    207 			if (!tfsreq_ie_start)
    208 				tfsreq_ie_start = (u8 *) pos;
    209 			tfsreq_ie_end = (u8 *) pos;
    210 		} else
    211 			wpa_printf(MSG_DEBUG, "WNM: EID %d not recognized",
    212 				   *pos);
    213 		pos += ie_len + 2;
    214 	}
    215 
    216 	if (!wnmsleep_ie) {
    217 		wpa_printf(MSG_DEBUG, "No WNM-Sleep IE found");
    218 		return;
    219 	}
    220 
    221 	if (wnmsleep_ie->action_type == WNM_SLEEP_MODE_ENTER &&
    222 	    tfsreq_ie_start && tfsreq_ie_end &&
    223 	    tfsreq_ie_end - tfsreq_ie_start >= 0) {
    224 		tfsreq_ie_len = (tfsreq_ie_end + tfsreq_ie_end[1] + 2) -
    225 			tfsreq_ie_start;
    226 		wpa_printf(MSG_DEBUG, "TFS Req IE(s) found");
    227 		/* pass the TFS Req IE(s) to driver for processing */
    228 		if (ieee80211_11_set_tfs_ie(hapd, addr, tfsreq_ie_start,
    229 					    &tfsreq_ie_len,
    230 					    WNM_SLEEP_TFS_REQ_IE_SET))
    231 			wpa_printf(MSG_DEBUG, "Fail to set TFS Req IE");
    232 	}
    233 
    234 	ieee802_11_send_wnmsleep_resp(hapd, addr, dialog_token,
    235 				      wnmsleep_ie->action_type,
    236 				      wnmsleep_ie->intval);
    237 
    238 	if (wnmsleep_ie->action_type == WNM_SLEEP_MODE_EXIT) {
    239 		/* clear the tfs after sending the resp frame */
    240 		ieee80211_11_set_tfs_ie(hapd, addr, tfsreq_ie_start,
    241 					&tfsreq_ie_len, WNM_SLEEP_TFS_IE_DEL);
    242 	}
    243 }
    244 
    245 
    246 int ieee802_11_rx_wnm_action_ap(struct hostapd_data *hapd,
    247 				struct rx_action *action)
    248 {
    249 	if (action->len < 1 || action->data == NULL)
    250 		return -1;
    251 
    252 	switch (action->data[0]) {
    253 	case WNM_BSS_TRANS_MGMT_QUERY:
    254 		wpa_printf(MSG_DEBUG, "WNM: BSS Transition Management Query");
    255 		/* TODO */
    256 		return -1;
    257 	case WNM_BSS_TRANS_MGMT_RESP:
    258 		wpa_printf(MSG_DEBUG, "WNM: BSS Transition Management "
    259 			   "Response");
    260 		/* TODO */
    261 		return -1;
    262 	case WNM_SLEEP_MODE_REQ:
    263 		ieee802_11_rx_wnmsleep_req(hapd, action->sa, action->data + 1,
    264 					   action->len - 1);
    265 		return 0;
    266 	}
    267 
    268 	wpa_printf(MSG_DEBUG, "WNM: Unsupported WNM Action %u from " MACSTR,
    269 		   action->data[0], MAC2STR(action->sa));
    270 	return -1;
    271 }
    272