hostap/wlantest/rx_data.c - nest-cam/4320010/hostap - Git at Google

 /*
  * Received Data frame processing
  * Copyright (c) 2010-2015, Jouni Malinen <j@w1.fi>
  *
  * This software may be distributed under the terms of the BSD license.
  * See README for more details.
  */

 #include "utils/includes.h"
 #include <linux/if_ether.h>

 #include "utils/common.h"
 #include "common/defs.h"
 #include "common/ieee802_11_defs.h"
 #include "wlantest.h"


 static const char * data_stype(u16 stype)
 {
 	switch (stype) {
 	case WLAN_FC_STYPE_DATA:
 		return "DATA";
 	case WLAN_FC_STYPE_DATA_CFACK:
 		return "DATA-CFACK";
 	case WLAN_FC_STYPE_DATA_CFPOLL:
 		return "DATA-CFPOLL";
 	case WLAN_FC_STYPE_DATA_CFACKPOLL:
 		return "DATA-CFACKPOLL";
 	case WLAN_FC_STYPE_NULLFUNC:
 		return "NULLFUNC";
 	case WLAN_FC_STYPE_CFACK:
 		return "CFACK";
 	case WLAN_FC_STYPE_CFPOLL:
 		return "CFPOLL";
 	case WLAN_FC_STYPE_CFACKPOLL:
 		return "CFACKPOLL";
 	case WLAN_FC_STYPE_QOS_DATA:
 		return "QOSDATA";
 	case WLAN_FC_STYPE_QOS_DATA_CFACK:
 		return "QOSDATA-CFACK";
 	case WLAN_FC_STYPE_QOS_DATA_CFPOLL:
 		return "QOSDATA-CFPOLL";
 	case WLAN_FC_STYPE_QOS_DATA_CFACKPOLL:
 		return "QOSDATA-CFACKPOLL";
 	case WLAN_FC_STYPE_QOS_NULL:
 		return "QOS-NULL";
 	case WLAN_FC_STYPE_QOS_CFPOLL:
 		return "QOS-CFPOLL";
 	case WLAN_FC_STYPE_QOS_CFACKPOLL:
 		return "QOS-CFACKPOLL";
 	}
 	return "??";
 }


 static void rx_data_eth(struct wlantest *wt, const u8 *bssid,
 			const u8 *sta_addr, const u8 *dst, const u8 *src,
 			u16 ethertype, const u8 *data, size_t len, int prot,
 			const u8 *peer_addr)
 {
 	switch (ethertype) {
 	case ETH_P_PAE:
 		rx_data_eapol(wt, dst, src, data, len, prot);
 		break;
 	case ETH_P_IP:
 		rx_data_ip(wt, bssid, sta_addr, dst, src, data, len,
 			   peer_addr);
 		break;
 	case 0x890d:
 		rx_data_80211_encap(wt, bssid, sta_addr, dst, src, data, len);
 		break;
 	}
 }


 static void rx_data_process(struct wlantest *wt, const u8 *bssid,
 			    const u8 *sta_addr,
 			    const u8 *dst, const u8 *src,
 			    const u8 *data, size_t len, int prot,
 			    const u8 *peer_addr)
 {
 	if (len == 0)
 		return;

 	if (len >= 8 && os_memcmp(data, "\xaa\xaa\x03\x00\x00\x00", 6) == 0) {
 		rx_data_eth(wt, bssid, sta_addr, dst, src,
 			    WPA_GET_BE16(data + 6), data + 8, len - 8, prot,
 			    peer_addr);
 		return;
 	}

 	wpa_hexdump(MSG_DEBUG, "Unrecognized LLC", data, len > 8 ? 8 : len);
 }


 static u8 * try_all_ptk(struct wlantest *wt, int pairwise_cipher,
 			const struct ieee80211_hdr *hdr,
 			const u8 *data, size_t data_len, size_t *decrypted_len)
 {
 	struct wlantest_ptk *ptk;
 	u8 *decrypted;
 	int prev_level = wpa_debug_level;

 	wpa_debug_level = MSG_WARNING;
 	dl_list_for_each(ptk, &wt->ptk, struct wlantest_ptk, list) {
 		unsigned int tk_len = ptk->ptk_len - 32;
 		decrypted = NULL;
 		if ((pairwise_cipher == WPA_CIPHER_CCMP ||
 		     pairwise_cipher == 0) && tk_len == 16) {
 			decrypted = ccmp_decrypt(ptk->ptk.tk, hdr, data,
 						 data_len, decrypted_len);
 		} else if ((pairwise_cipher == WPA_CIPHER_CCMP_256 ||
 			    pairwise_cipher == 0) && tk_len == 32) {
 			decrypted = ccmp_256_decrypt(ptk->ptk.tk, hdr, data,
 						     data_len, decrypted_len);
 		} else if ((pairwise_cipher == WPA_CIPHER_GCMP ||
 			    pairwise_cipher == WPA_CIPHER_GCMP_256 ||
 			    pairwise_cipher == 0) &&
 			   (tk_len == 16 || tk_len == 32)) {
 			decrypted = gcmp_decrypt(ptk->ptk.tk, tk_len, hdr,
 						 data, data_len, decrypted_len);
 		} else if ((pairwise_cipher == WPA_CIPHER_TKIP ||
 			    pairwise_cipher == 0) && tk_len == 32) {
 			decrypted = tkip_decrypt(ptk->ptk.tk, hdr, data,
 						 data_len, decrypted_len);
 		}
 		if (decrypted) {
 			wpa_debug_level = prev_level;
 			add_note(wt, MSG_DEBUG, "Found PTK match from list of all known PTKs");
 			return decrypted;
 		}
 	}
 	wpa_debug_level = prev_level;

 	return NULL;
 }


 static void rx_data_bss_prot_group(struct wlantest *wt,
 				   const struct ieee80211_hdr *hdr,
 				   const u8 *qos, const u8 *dst, const u8 *src,
 				   const u8 *data, size_t len)
 {
 	struct wlantest_bss *bss;
 	int keyid;
 	u8 *decrypted = NULL;
 	size_t dlen;
 	u8 pn[6];

 	bss = bss_get(wt, hdr->addr2);
 	if (bss == NULL)
 		return;
 	if (len < 4) {
 		add_note(wt, MSG_INFO, "Too short group addressed data frame");
 		return;
 	}

 	if (bss->group_cipher & (WPA_CIPHER_TKIP | WPA_CIPHER_CCMP) &&
 	    !(data[3] & 0x20)) {
 		add_note(wt, MSG_INFO, "Expected TKIP/CCMP frame from "
 			 MACSTR " did not have ExtIV bit set to 1",
 			 MAC2STR(bss->bssid));
 		return;
 	}

 	if (bss->group_cipher == WPA_CIPHER_TKIP) {
 		if (data[3] & 0x1f) {
 			add_note(wt, MSG_INFO, "TKIP frame from " MACSTR
 				 " used non-zero reserved bit",
 				 MAC2STR(bss->bssid));
 		}
 		if (data[1] != ((data[0] | 0x20) & 0x7f)) {
 			add_note(wt, MSG_INFO, "TKIP frame from " MACSTR
 				 " used incorrect WEPSeed[1] (was 0x%x, "
 				 "expected 0x%x)",
 				 MAC2STR(bss->bssid), data[1],
 				 (data[0] | 0x20) & 0x7f);
 		}
 	} else if (bss->group_cipher == WPA_CIPHER_CCMP) {
 		if (data[2] != 0 || (data[3] & 0x1f) != 0) {
 			add_note(wt, MSG_INFO, "CCMP frame from " MACSTR
 				 " used non-zero reserved bit",
 				 MAC2STR(bss->bssid));
 		}
 	}

 	keyid = data[3] >> 6;
 	if (bss->gtk_len[keyid] == 0 && bss->group_cipher != WPA_CIPHER_WEP40)
 	{
 		add_note(wt, MSG_MSGDUMP, "No GTK known to decrypt the frame "
 			 "(A2=" MACSTR " KeyID=%d)",
 			 MAC2STR(hdr->addr2), keyid);
 		return;
 	}

 	if (bss->group_cipher == WPA_CIPHER_TKIP)
 		tkip_get_pn(pn, data);
 	else if (bss->group_cipher == WPA_CIPHER_WEP40)
 		goto skip_replay_det;
 	else
 		ccmp_get_pn(pn, data);
 	if (os_memcmp(pn, bss->rsc[keyid], 6) <= 0) {
 		u16 seq_ctrl = le_to_host16(hdr->seq_ctrl);
 		add_note(wt, MSG_INFO, "CCMP/TKIP replay detected: A1=" MACSTR
 			 " A2=" MACSTR " A3=" MACSTR " seq=%u frag=%u%s",
 			 MAC2STR(hdr->addr1), MAC2STR(hdr->addr2),
 			 MAC2STR(hdr->addr3),
 			 WLAN_GET_SEQ_SEQ(seq_ctrl),
 			 WLAN_GET_SEQ_FRAG(seq_ctrl),
 			 (le_to_host16(hdr->frame_control) & WLAN_FC_RETRY) ?
 			 " Retry" : "");
 		wpa_hexdump(MSG_INFO, "RX PN", pn, 6);
 		wpa_hexdump(MSG_INFO, "RSC", bss->rsc[keyid], 6);
 	}

 skip_replay_det:
 	if (bss->group_cipher == WPA_CIPHER_TKIP)
 		decrypted = tkip_decrypt(bss->gtk[keyid], hdr, data, len,
 					 &dlen);
 	else if (bss->group_cipher == WPA_CIPHER_WEP40)
 		decrypted = wep_decrypt(wt, hdr, data, len, &dlen);
 	else if (bss->group_cipher == WPA_CIPHER_CCMP)
 		decrypted = ccmp_decrypt(bss->gtk[keyid], hdr, data, len,
 					 &dlen);
 	else if (bss->group_cipher == WPA_CIPHER_CCMP_256)
 		decrypted = ccmp_256_decrypt(bss->gtk[keyid], hdr, data, len,
 					     &dlen);
 	else if (bss->group_cipher == WPA_CIPHER_GCMP ||
 		 bss->group_cipher == WPA_CIPHER_GCMP_256)
 		decrypted = gcmp_decrypt(bss->gtk[keyid], bss->gtk_len[keyid],
 					 hdr, data, len, &dlen);

 	if (decrypted) {
 		rx_data_process(wt, bss->bssid, NULL, dst, src, decrypted,
 				dlen, 1, NULL);
 		os_memcpy(bss->rsc[keyid], pn, 6);
 		write_pcap_decrypted(wt, (const u8 *) hdr, 24 + (qos ? 2 : 0),
 				     decrypted, dlen);
 	} else
 		add_note(wt, MSG_DEBUG, "Failed to decrypt frame");
 	os_free(decrypted);
 }


 static void rx_data_bss_prot(struct wlantest *wt,
 			     const struct ieee80211_hdr *hdr, const u8 *qos,
 			     const u8 *dst, const u8 *src, const u8 *data,
 			     size_t len)
 {
 	struct wlantest_bss *bss;
 	struct wlantest_sta *sta, *sta2;
 	int keyid;
 	u16 fc = le_to_host16(hdr->frame_control);
 	u8 *decrypted;
 	size_t dlen;
 	int tid;
 	u8 pn[6], *rsc;
 	struct wlantest_tdls *tdls = NULL, *found;
 	const u8 *tk = NULL;
 	int ptk_iter_done = 0;
 	int try_ptk_iter = 0;

 	if (hdr->addr1[0] & 0x01) {
 		rx_data_bss_prot_group(wt, hdr, qos, dst, src, data, len);
 		return;
 	}

 	if (fc & WLAN_FC_TODS) {
 		bss = bss_get(wt, hdr->addr1);
 		if (bss == NULL)
 			return;
 		sta = sta_get(bss, hdr->addr2);
 		if (sta)
 			sta->counters[WLANTEST_STA_COUNTER_PROT_DATA_TX]++;
 	} else if (fc & WLAN_FC_FROMDS) {
 		bss = bss_get(wt, hdr->addr2);
 		if (bss == NULL)
 			return;
 		sta = sta_get(bss, hdr->addr1);
 	} else {
 		bss = bss_get(wt, hdr->addr3);
 		if (bss == NULL)
 			return;
 		sta = sta_find(bss, hdr->addr2);
 		sta2 = sta_find(bss, hdr->addr1);
 		if (sta == NULL || sta2 == NULL)
 			return;
 		found = NULL;
 		dl_list_for_each(tdls, &bss->tdls, struct wlantest_tdls, list)
 		{
 			if ((tdls->init == sta && tdls->resp == sta2) ||
 			    (tdls->init == sta2 && tdls->resp == sta)) {
 				found = tdls;
 				if (tdls->link_up)
 					break;
 			}
 		}
 		if (found) {
 			if (!found->link_up)
 				add_note(wt, MSG_DEBUG,
 					 "TDLS: Link not up, but Data "
 					 "frame seen");
 			tk = found->tpk.tk;
 			tdls = found;
 		}
 	}
 	if ((sta == NULL ||
 	     (!sta->ptk_set && sta->pairwise_cipher != WPA_CIPHER_WEP40)) &&
 	    tk == NULL) {
 		add_note(wt, MSG_MSGDUMP, "No PTK known to decrypt the frame");
 		if (dl_list_empty(&wt->ptk))
 			return;
 		try_ptk_iter = 1;
 	}

 	if (len < 4) {
 		add_note(wt, MSG_INFO, "Too short encrypted data frame");
 		return;
 	}

 	if (sta == NULL)
 		return;
 	if (sta->pairwise_cipher & (WPA_CIPHER_TKIP | WPA_CIPHER_CCMP) &&
 	    !(data[3] & 0x20)) {
 		add_note(wt, MSG_INFO, "Expected TKIP/CCMP frame from "
 			 MACSTR " did not have ExtIV bit set to 1",
 			 MAC2STR(src));
 		return;
 	}

 	if (tk == NULL && sta->pairwise_cipher == WPA_CIPHER_TKIP) {
 		if (data[3] & 0x1f) {
 			add_note(wt, MSG_INFO, "TKIP frame from " MACSTR
 				 " used non-zero reserved bit",
 				 MAC2STR(hdr->addr2));
 		}
 		if (data[1] != ((data[0] | 0x20) & 0x7f)) {
 			add_note(wt, MSG_INFO, "TKIP frame from " MACSTR
 				 " used incorrect WEPSeed[1] (was 0x%x, "
 				 "expected 0x%x)",
 				 MAC2STR(hdr->addr2), data[1],
 				 (data[0] | 0x20) & 0x7f);
 		}
 	} else if (tk || sta->pairwise_cipher == WPA_CIPHER_CCMP) {
 		if (data[2] != 0 || (data[3] & 0x1f) != 0) {
 			add_note(wt, MSG_INFO, "CCMP frame from " MACSTR
 				 " used non-zero reserved bit",
 				 MAC2STR(hdr->addr2));
 		}
 	}

 	keyid = data[3] >> 6;
 	if (keyid != 0) {
 		add_note(wt, MSG_INFO, "Unexpected non-zero KeyID %d in "
 			 "individually addressed Data frame from " MACSTR,
 			 keyid, MAC2STR(hdr->addr2));
 	}

 	if (qos) {
 		tid = qos[0] & 0x0f;
 		if (fc & WLAN_FC_TODS)
 			sta->tx_tid[tid]++;
 		else
 			sta->rx_tid[tid]++;
 	} else {
 		tid = 0;
 		if (fc & WLAN_FC_TODS)
 			sta->tx_tid[16]++;
 		else
 			sta->rx_tid[16]++;
 	}
 	if (tk) {
 		if (os_memcmp(hdr->addr2, tdls->init->addr, ETH_ALEN) == 0)
 			rsc = tdls->rsc_init[tid];
 		else
 			rsc = tdls->rsc_resp[tid];
 	} else if (fc & WLAN_FC_TODS)
 		rsc = sta->rsc_tods[tid];
 	else
 		rsc = sta->rsc_fromds[tid];


 	if (tk == NULL && sta->pairwise_cipher == WPA_CIPHER_TKIP)
 		tkip_get_pn(pn, data);
 	else if (sta->pairwise_cipher == WPA_CIPHER_WEP40)
 		goto skip_replay_det;
 	else
 		ccmp_get_pn(pn, data);
 	if (os_memcmp(pn, rsc, 6) <= 0) {
 		u16 seq_ctrl = le_to_host16(hdr->seq_ctrl);
 		add_note(wt, MSG_INFO, "CCMP/TKIP replay detected: A1=" MACSTR
 			 " A2=" MACSTR " A3=" MACSTR " seq=%u frag=%u%s",
 			 MAC2STR(hdr->addr1), MAC2STR(hdr->addr2),
 			 MAC2STR(hdr->addr3),
 			 WLAN_GET_SEQ_SEQ(seq_ctrl),
 			 WLAN_GET_SEQ_FRAG(seq_ctrl),
 			 (le_to_host16(hdr->frame_control) &  WLAN_FC_RETRY) ?
 			 " Retry" : "");
 		wpa_hexdump(MSG_INFO, "RX PN", pn, 6);
 		wpa_hexdump(MSG_INFO, "RSC", rsc, 6);
 	}

 skip_replay_det:
 	if (tk) {
 		if (sta->pairwise_cipher == WPA_CIPHER_CCMP_256)
 			decrypted = ccmp_256_decrypt(tk, hdr, data, len, &dlen);
 		else if (sta->pairwise_cipher == WPA_CIPHER_GCMP ||
 			 sta->pairwise_cipher == WPA_CIPHER_GCMP_256)
 			decrypted = gcmp_decrypt(tk, sta->tk_len, hdr, data,
 						 len, &dlen);
 		else
 			decrypted = ccmp_decrypt(tk, hdr, data, len, &dlen);
 	} else if (sta->pairwise_cipher == WPA_CIPHER_TKIP) {
 		decrypted = tkip_decrypt(sta->ptk.tk, hdr, data, len, &dlen);
 	} else if (sta->pairwise_cipher == WPA_CIPHER_WEP40) {
 		decrypted = wep_decrypt(wt, hdr, data, len, &dlen);
 	} else if (sta->ptk_set) {
 		if (sta->pairwise_cipher == WPA_CIPHER_CCMP_256)
 			decrypted = ccmp_256_decrypt(sta->ptk.tk, hdr, data,
 						     len, &dlen);
 		else if (sta->pairwise_cipher == WPA_CIPHER_GCMP ||
 			 sta->pairwise_cipher == WPA_CIPHER_GCMP_256)
 			decrypted = gcmp_decrypt(sta->ptk.tk, sta->tk_len,
 						 hdr, data, len, &dlen);
 		else
 			decrypted = ccmp_decrypt(sta->ptk.tk, hdr, data, len,
 						 &dlen);
 	} else {
 		decrypted = try_all_ptk(wt, sta->pairwise_cipher, hdr, data,
 					len, &dlen);
 		ptk_iter_done = 1;
 	}
 	if (!decrypted && !ptk_iter_done) {
 		decrypted = try_all_ptk(wt, sta->pairwise_cipher, hdr, data,
 					len, &dlen);
 		if (decrypted) {
 			add_note(wt, MSG_DEBUG, "Current PTK did not work, but found a match from all known PTKs");
 		}
 	}
 	if (decrypted) {
 		u16 fc = le_to_host16(hdr->frame_control);
 		const u8 *peer_addr = NULL;
 		if (!(fc & (WLAN_FC_FROMDS | WLAN_FC_TODS)))
 			peer_addr = hdr->addr1;
 		os_memcpy(rsc, pn, 6);
 		rx_data_process(wt, bss->bssid, sta->addr, dst, src, decrypted,
 				dlen, 1, peer_addr);
 		write_pcap_decrypted(wt, (const u8 *) hdr, 24 + (qos ? 2 : 0),
 				     decrypted, dlen);
 	} else if (!try_ptk_iter)
 		add_note(wt, MSG_DEBUG, "Failed to decrypt frame");
 	os_free(decrypted);
 }


 static void rx_data_bss(struct wlantest *wt, const struct ieee80211_hdr *hdr,
 			const u8 *qos, const u8 *dst, const u8 *src,
 			const u8 *data, size_t len)
 {
 	u16 fc = le_to_host16(hdr->frame_control);
 	int prot = !!(fc & WLAN_FC_ISWEP);

 	if (qos) {
 		u8 ack = (qos[0] & 0x60) >> 5;
 		wpa_printf(MSG_MSGDUMP, "BSS DATA: " MACSTR " -> " MACSTR
 			   " len=%u%s tid=%u%s%s",
 			   MAC2STR(src), MAC2STR(dst), (unsigned int) len,
 			   prot ? " Prot" : "", qos[0] & 0x0f,
 			   (qos[0] & 0x10) ? " EOSP" : "",
 			   ack == 0 ? "" :
 			   (ack == 1 ? " NoAck" :
 			    (ack == 2 ? " NoExpAck" : " BA")));
 	} else {
 		wpa_printf(MSG_MSGDUMP, "BSS DATA: " MACSTR " -> " MACSTR
 			   " len=%u%s",
 			   MAC2STR(src), MAC2STR(dst), (unsigned int) len,
 			   prot ? " Prot" : "");
 	}

 	if (prot)
 		rx_data_bss_prot(wt, hdr, qos, dst, src, data, len);
 	else {
 		const u8 *bssid, *sta_addr, *peer_addr;
 		struct wlantest_bss *bss;

 		if (fc & WLAN_FC_TODS) {
 			bssid = hdr->addr1;
 			sta_addr = hdr->addr2;
 			peer_addr = NULL;
 		} else if (fc & WLAN_FC_FROMDS) {
 			bssid = hdr->addr2;
 			sta_addr = hdr->addr1;
 			peer_addr = NULL;
 		} else {
 			bssid = hdr->addr3;
 			sta_addr = hdr->addr2;
 			peer_addr = hdr->addr1;
 		}

 		bss = bss_get(wt, bssid);
 		if (bss) {
 			struct wlantest_sta *sta = sta_get(bss, sta_addr);

 			if (sta) {
 				if (qos) {
 					int tid = qos[0] & 0x0f;
 					if (fc & WLAN_FC_TODS)
 						sta->tx_tid[tid]++;
 					else
 						sta->rx_tid[tid]++;
 				} else {
 					if (fc & WLAN_FC_TODS)
 						sta->tx_tid[16]++;
 					else
 						sta->rx_tid[16]++;
 				}
 			}
 		}

 		rx_data_process(wt, bssid, sta_addr, dst, src, data, len, 0,
 				peer_addr);
 	}
 }


 static struct wlantest_tdls * get_tdls(struct wlantest *wt, const u8 *bssid,
 				       const u8 *sta1_addr,
 				       const u8 *sta2_addr)
 {
 	struct wlantest_bss *bss;
 	struct wlantest_sta *sta1, *sta2;
 	struct wlantest_tdls *tdls, *found = NULL;

 	bss = bss_find(wt, bssid);
 	if (bss == NULL)
 		return NULL;
 	sta1 = sta_find(bss, sta1_addr);
 	if (sta1 == NULL)
 		return NULL;
 	sta2 = sta_find(bss, sta2_addr);
 	if (sta2 == NULL)
 		return NULL;

 	dl_list_for_each(tdls, &bss->tdls, struct wlantest_tdls, list) {
 		if ((tdls->init == sta1 && tdls->resp == sta2) ||
 		    (tdls->init == sta2 && tdls->resp == sta1)) {
 			found = tdls;
 			if (tdls->link_up)
 				break;
 		}
 	}

 	return found;
 }


 static void add_direct_link(struct wlantest *wt, const u8 *bssid,
 			    const u8 *sta1_addr, const u8 *sta2_addr)
 {
 	struct wlantest_tdls *tdls;

 	tdls = get_tdls(wt, bssid, sta1_addr, sta2_addr);
 	if (tdls == NULL)
 		return;

 	if (tdls->link_up)
 		tdls->counters[WLANTEST_TDLS_COUNTER_VALID_DIRECT_LINK]++;
 	else
 		tdls->counters[WLANTEST_TDLS_COUNTER_INVALID_DIRECT_LINK]++;
 }


 static void add_ap_path(struct wlantest *wt, const u8 *bssid,
 			const u8 *sta1_addr, const u8 *sta2_addr)
 {
 	struct wlantest_tdls *tdls;

 	tdls = get_tdls(wt, bssid, sta1_addr, sta2_addr);
 	if (tdls == NULL)
 		return;

 	if (tdls->link_up)
 		tdls->counters[WLANTEST_TDLS_COUNTER_INVALID_AP_PATH]++;
 	else
 		tdls->counters[WLANTEST_TDLS_COUNTER_VALID_AP_PATH]++;
 }


 void rx_data(struct wlantest *wt, const u8 *data, size_t len)
 {
 	const struct ieee80211_hdr *hdr;
 	u16 fc, stype;
 	size_t hdrlen;
 	const u8 *qos = NULL;

 	if (len < 24)
 		return;

 	hdr = (const struct ieee80211_hdr *) data;
 	fc = le_to_host16(hdr->frame_control);
 	stype = WLAN_FC_GET_STYPE(fc);
 	hdrlen = 24;
 	if ((fc & (WLAN_FC_TODS | WLAN_FC_FROMDS)) ==
 	    (WLAN_FC_TODS | WLAN_FC_FROMDS))
 		hdrlen += ETH_ALEN;
 	if (stype & 0x08) {
 		qos = data + hdrlen;
 		hdrlen += 2;
 	}
 	if (len < hdrlen)
 		return;
 	wt->rx_data++;

 	switch (fc & (WLAN_FC_TODS | WLAN_FC_FROMDS)) {
 	case 0:
 		wpa_printf(MSG_EXCESSIVE, "DATA %s%s%s IBSS DA=" MACSTR " SA="
 			   MACSTR " BSSID=" MACSTR,
 			   data_stype(WLAN_FC_GET_STYPE(fc)),
 			   fc & WLAN_FC_PWRMGT ? " PwrMgt" : "",
 			   fc & WLAN_FC_ISWEP ? " Prot" : "",
 			   MAC2STR(hdr->addr1), MAC2STR(hdr->addr2),
 			   MAC2STR(hdr->addr3));
 		add_direct_link(wt, hdr->addr3, hdr->addr1, hdr->addr2);
 		rx_data_bss(wt, hdr, qos, hdr->addr1, hdr->addr2,
 			    data + hdrlen, len - hdrlen);
 		break;
 	case WLAN_FC_FROMDS:
 		wpa_printf(MSG_EXCESSIVE, "DATA %s%s%s FromDS DA=" MACSTR
 			   " BSSID=" MACSTR " SA=" MACSTR,
 			   data_stype(WLAN_FC_GET_STYPE(fc)),
 			   fc & WLAN_FC_PWRMGT ? " PwrMgt" : "",
 			   fc & WLAN_FC_ISWEP ? " Prot" : "",
 			   MAC2STR(hdr->addr1), MAC2STR(hdr->addr2),
 			   MAC2STR(hdr->addr3));
 		add_ap_path(wt, hdr->addr2, hdr->addr1, hdr->addr3);
 		rx_data_bss(wt, hdr, qos, hdr->addr1, hdr->addr3,
 			    data + hdrlen, len - hdrlen);
 		break;
 	case WLAN_FC_TODS:
 		wpa_printf(MSG_EXCESSIVE, "DATA %s%s%s ToDS BSSID=" MACSTR
 			   " SA=" MACSTR " DA=" MACSTR,
 			   data_stype(WLAN_FC_GET_STYPE(fc)),
 			   fc & WLAN_FC_PWRMGT ? " PwrMgt" : "",
 			   fc & WLAN_FC_ISWEP ? " Prot" : "",
 			   MAC2STR(hdr->addr1), MAC2STR(hdr->addr2),
 			   MAC2STR(hdr->addr3));
 		add_ap_path(wt, hdr->addr1, hdr->addr3, hdr->addr2);
 		rx_data_bss(wt, hdr, qos, hdr->addr3, hdr->addr2,
 			    data + hdrlen, len - hdrlen);
 		break;
 	case WLAN_FC_TODS | WLAN_FC_FROMDS:
 		wpa_printf(MSG_EXCESSIVE, "DATA %s%s%s WDS RA=" MACSTR " TA="
 			   MACSTR " DA=" MACSTR " SA=" MACSTR,
 			   data_stype(WLAN_FC_GET_STYPE(fc)),
 			   fc & WLAN_FC_PWRMGT ? " PwrMgt" : "",
 			   fc & WLAN_FC_ISWEP ? " Prot" : "",
 			   MAC2STR(hdr->addr1), MAC2STR(hdr->addr2),
 			   MAC2STR(hdr->addr3),
 			   MAC2STR((const u8 *) (hdr + 1)));
 		break;
 	}
 }
	/*
	* Received Data frame processing
	* Copyright (c) 2010-2015, Jouni Malinen <j@w1.fi>
	*
	* This software may be distributed under the terms of the BSD license.
	* See README for more details.
	*/

	#include "utils/includes.h"
	#include <linux/if_ether.h>

	#include "utils/common.h"
	#include "common/defs.h"
	#include "common/ieee802_11_defs.h"
	#include "wlantest.h"


	static const char * data_stype(u16 stype)
	{
	switch (stype) {
	case WLAN_FC_STYPE_DATA:
	return "DATA";
	case WLAN_FC_STYPE_DATA_CFACK:
	return "DATA-CFACK";
	case WLAN_FC_STYPE_DATA_CFPOLL:
	return "DATA-CFPOLL";
	case WLAN_FC_STYPE_DATA_CFACKPOLL:
	return "DATA-CFACKPOLL";
	case WLAN_FC_STYPE_NULLFUNC:
	return "NULLFUNC";
	case WLAN_FC_STYPE_CFACK:
	return "CFACK";
	case WLAN_FC_STYPE_CFPOLL:
	return "CFPOLL";
	case WLAN_FC_STYPE_CFACKPOLL:
	return "CFACKPOLL";
	case WLAN_FC_STYPE_QOS_DATA:
	return "QOSDATA";
	case WLAN_FC_STYPE_QOS_DATA_CFACK:
	return "QOSDATA-CFACK";
	case WLAN_FC_STYPE_QOS_DATA_CFPOLL:
	return "QOSDATA-CFPOLL";
	case WLAN_FC_STYPE_QOS_DATA_CFACKPOLL:
	return "QOSDATA-CFACKPOLL";
	case WLAN_FC_STYPE_QOS_NULL:
	return "QOS-NULL";
	case WLAN_FC_STYPE_QOS_CFPOLL:
	return "QOS-CFPOLL";
	case WLAN_FC_STYPE_QOS_CFACKPOLL:
	return "QOS-CFACKPOLL";
	}
	return "??";
	}


	static void rx_data_eth(struct wlantest wt, const u8 bssid,
	const u8 sta_addr, const u8 dst, const u8 *src,
	u16 ethertype, const u8 *data, size_t len, int prot,
	const u8 *peer_addr)
	{
	switch (ethertype) {
	case ETH_P_PAE:
	rx_data_eapol(wt, dst, src, data, len, prot);
	break;
	case ETH_P_IP:
	rx_data_ip(wt, bssid, sta_addr, dst, src, data, len,
	peer_addr);
	break;
	case 0x890d:
	rx_data_80211_encap(wt, bssid, sta_addr, dst, src, data, len);
	break;
	}
	}


	static void rx_data_process(struct wlantest wt, const u8 bssid,
	const u8 *sta_addr,
	const u8 dst, const u8 src,
	const u8 *data, size_t len, int prot,
	const u8 *peer_addr)
	{
	if (len == 0)
	return;

	if (len >= 8 && os_memcmp(data, "\xaa\xaa\x03\x00\x00\x00", 6) == 0) {
	rx_data_eth(wt, bssid, sta_addr, dst, src,
	WPA_GET_BE16(data + 6), data + 8, len - 8, prot,
	peer_addr);
	return;
	}

	wpa_hexdump(MSG_DEBUG, "Unrecognized LLC", data, len > 8 ? 8 : len);
	}


	static u8 * try_all_ptk(struct wlantest *wt, int pairwise_cipher,
	const struct ieee80211_hdr *hdr,
	const u8 data, size_t data_len, size_t decrypted_len)
	{
	struct wlantest_ptk *ptk;
	u8 *decrypted;
	int prev_level = wpa_debug_level;

	wpa_debug_level = MSG_WARNING;
	dl_list_for_each(ptk, &wt->ptk, struct wlantest_ptk, list) {
	unsigned int tk_len = ptk->ptk_len - 32;
	decrypted = NULL;
	if ((pairwise_cipher == WPA_CIPHER_CCMP \|\|
	pairwise_cipher == 0) && tk_len == 16) {
	decrypted = ccmp_decrypt(ptk->ptk.tk, hdr, data,
	data_len, decrypted_len);
	} else if ((pairwise_cipher == WPA_CIPHER_CCMP_256 \|\|
	pairwise_cipher == 0) && tk_len == 32) {
	decrypted = ccmp_256_decrypt(ptk->ptk.tk, hdr, data,
	data_len, decrypted_len);
	} else if ((pairwise_cipher == WPA_CIPHER_GCMP \|\|
	pairwise_cipher == WPA_CIPHER_GCMP_256 \|\|
	pairwise_cipher == 0) &&
	(tk_len == 16 \|\| tk_len == 32)) {
	decrypted = gcmp_decrypt(ptk->ptk.tk, tk_len, hdr,
	data, data_len, decrypted_len);
	} else if ((pairwise_cipher == WPA_CIPHER_TKIP \|\|
	pairwise_cipher == 0) && tk_len == 32) {
	decrypted = tkip_decrypt(ptk->ptk.tk, hdr, data,
	data_len, decrypted_len);
	}
	if (decrypted) {
	wpa_debug_level = prev_level;
	add_note(wt, MSG_DEBUG, "Found PTK match from list of all known PTKs");
	return decrypted;
	}
	}
	wpa_debug_level = prev_level;

	return NULL;
	}


	static void rx_data_bss_prot_group(struct wlantest *wt,
	const struct ieee80211_hdr *hdr,
	const u8 qos, const u8 dst, const u8 *src,
	const u8 *data, size_t len)
	{
	struct wlantest_bss *bss;
	int keyid;
	u8 *decrypted = NULL;
	size_t dlen;
	u8 pn[6];

	bss = bss_get(wt, hdr->addr2);
	if (bss == NULL)
	return;
	if (len < 4) {
	add_note(wt, MSG_INFO, "Too short group addressed data frame");
	return;
	}

	if (bss->group_cipher & (WPA_CIPHER_TKIP \| WPA_CIPHER_CCMP) &&
	!(data[3] & 0x20)) {
	add_note(wt, MSG_INFO, "Expected TKIP/CCMP frame from "
	MACSTR " did not have ExtIV bit set to 1",
	MAC2STR(bss->bssid));
	return;
	}

	if (bss->group_cipher == WPA_CIPHER_TKIP) {
	if (data[3] & 0x1f) {
	add_note(wt, MSG_INFO, "TKIP frame from " MACSTR
	" used non-zero reserved bit",
	MAC2STR(bss->bssid));
	}
	if (data[1] != ((data[0] \| 0x20) & 0x7f)) {
	add_note(wt, MSG_INFO, "TKIP frame from " MACSTR
	" used incorrect WEPSeed[1] (was 0x%x, "
	"expected 0x%x)",
	MAC2STR(bss->bssid), data[1],
	(data[0] \| 0x20) & 0x7f);
	}
	} else if (bss->group_cipher == WPA_CIPHER_CCMP) {
	if (data[2] != 0 \|\| (data[3] & 0x1f) != 0) {
	add_note(wt, MSG_INFO, "CCMP frame from " MACSTR
	" used non-zero reserved bit",
	MAC2STR(bss->bssid));
	}
	}

	keyid = data[3] >> 6;
	if (bss->gtk_len[keyid] == 0 && bss->group_cipher != WPA_CIPHER_WEP40)
	{
	add_note(wt, MSG_MSGDUMP, "No GTK known to decrypt the frame "
	"(A2=" MACSTR " KeyID=%d)",
	MAC2STR(hdr->addr2), keyid);
	return;
	}

	if (bss->group_cipher == WPA_CIPHER_TKIP)
	tkip_get_pn(pn, data);
	else if (bss->group_cipher == WPA_CIPHER_WEP40)
	goto skip_replay_det;
	else
	ccmp_get_pn(pn, data);
	if (os_memcmp(pn, bss->rsc[keyid], 6) <= 0) {
	u16 seq_ctrl = le_to_host16(hdr->seq_ctrl);
	add_note(wt, MSG_INFO, "CCMP/TKIP replay detected: A1=" MACSTR
	" A2=" MACSTR " A3=" MACSTR " seq=%u frag=%u%s",
	MAC2STR(hdr->addr1), MAC2STR(hdr->addr2),
	MAC2STR(hdr->addr3),
	WLAN_GET_SEQ_SEQ(seq_ctrl),
	WLAN_GET_SEQ_FRAG(seq_ctrl),
	(le_to_host16(hdr->frame_control) & WLAN_FC_RETRY) ?
	" Retry" : "");
	wpa_hexdump(MSG_INFO, "RX PN", pn, 6);
	wpa_hexdump(MSG_INFO, "RSC", bss->rsc[keyid], 6);
	}

	skip_replay_det:
	if (bss->group_cipher == WPA_CIPHER_TKIP)
	decrypted = tkip_decrypt(bss->gtk[keyid], hdr, data, len,
	&dlen);
	else if (bss->group_cipher == WPA_CIPHER_WEP40)
	decrypted = wep_decrypt(wt, hdr, data, len, &dlen);
	else if (bss->group_cipher == WPA_CIPHER_CCMP)
	decrypted = ccmp_decrypt(bss->gtk[keyid], hdr, data, len,
	&dlen);
	else if (bss->group_cipher == WPA_CIPHER_CCMP_256)
	decrypted = ccmp_256_decrypt(bss->gtk[keyid], hdr, data, len,
	&dlen);
	else if (bss->group_cipher == WPA_CIPHER_GCMP \|\|
	bss->group_cipher == WPA_CIPHER_GCMP_256)
	decrypted = gcmp_decrypt(bss->gtk[keyid], bss->gtk_len[keyid],
	hdr, data, len, &dlen);

	if (decrypted) {
	rx_data_process(wt, bss->bssid, NULL, dst, src, decrypted,
	dlen, 1, NULL);
	os_memcpy(bss->rsc[keyid], pn, 6);
	write_pcap_decrypted(wt, (const u8 *) hdr, 24 + (qos ? 2 : 0),
	decrypted, dlen);
	} else
	add_note(wt, MSG_DEBUG, "Failed to decrypt frame");
	os_free(decrypted);
	}


	static void rx_data_bss_prot(struct wlantest *wt,
	const struct ieee80211_hdr hdr, const u8 qos,
	const u8 dst, const u8 src, const u8 *data,
	size_t len)
	{
	struct wlantest_bss *bss;
	struct wlantest_sta sta, sta2;
	int keyid;
	u16 fc = le_to_host16(hdr->frame_control);
	u8 *decrypted;
	size_t dlen;
	int tid;
	u8 pn[6], *rsc;
	struct wlantest_tdls tdls = NULL, found;
	const u8 *tk = NULL;
	int ptk_iter_done = 0;
	int try_ptk_iter = 0;

	if (hdr->addr1[0] & 0x01) {
	rx_data_bss_prot_group(wt, hdr, qos, dst, src, data, len);
	return;
	}

	if (fc & WLAN_FC_TODS) {
	bss = bss_get(wt, hdr->addr1);
	if (bss == NULL)
	return;
	sta = sta_get(bss, hdr->addr2);
	if (sta)
	sta->counters[WLANTEST_STA_COUNTER_PROT_DATA_TX]++;
	} else if (fc & WLAN_FC_FROMDS) {
	bss = bss_get(wt, hdr->addr2);
	if (bss == NULL)
	return;
	sta = sta_get(bss, hdr->addr1);
	} else {
	bss = bss_get(wt, hdr->addr3);
	if (bss == NULL)
	return;
	sta = sta_find(bss, hdr->addr2);
	sta2 = sta_find(bss, hdr->addr1);
	if (sta == NULL \|\| sta2 == NULL)
	return;
	found = NULL;
	dl_list_for_each(tdls, &bss->tdls, struct wlantest_tdls, list)
	{
	if ((tdls->init == sta && tdls->resp == sta2) \|\|
	(tdls->init == sta2 && tdls->resp == sta)) {
	found = tdls;
	if (tdls->link_up)
	break;
	}
	}
	if (found) {
	if (!found->link_up)
	add_note(wt, MSG_DEBUG,
	"TDLS: Link not up, but Data "
	"frame seen");
	tk = found->tpk.tk;
	tdls = found;
	}
	}
	if ((sta == NULL \|\|
	(!sta->ptk_set && sta->pairwise_cipher != WPA_CIPHER_WEP40)) &&
	tk == NULL) {
	add_note(wt, MSG_MSGDUMP, "No PTK known to decrypt the frame");
	if (dl_list_empty(&wt->ptk))
	return;
	try_ptk_iter = 1;
	}

	if (len < 4) {
	add_note(wt, MSG_INFO, "Too short encrypted data frame");
	return;
	}

	if (sta == NULL)
	return;
	if (sta->pairwise_cipher & (WPA_CIPHER_TKIP \| WPA_CIPHER_CCMP) &&
	!(data[3] & 0x20)) {
	add_note(wt, MSG_INFO, "Expected TKIP/CCMP frame from "
	MACSTR " did not have ExtIV bit set to 1",
	MAC2STR(src));
	return;
	}

	if (tk == NULL && sta->pairwise_cipher == WPA_CIPHER_TKIP) {
	if (data[3] & 0x1f) {
	add_note(wt, MSG_INFO, "TKIP frame from " MACSTR
	" used non-zero reserved bit",
	MAC2STR(hdr->addr2));
	}
	if (data[1] != ((data[0] \| 0x20) & 0x7f)) {
	add_note(wt, MSG_INFO, "TKIP frame from " MACSTR
	" used incorrect WEPSeed[1] (was 0x%x, "
	"expected 0x%x)",
	MAC2STR(hdr->addr2), data[1],
	(data[0] \| 0x20) & 0x7f);
	}
	} else if (tk \|\| sta->pairwise_cipher == WPA_CIPHER_CCMP) {
	if (data[2] != 0 \|\| (data[3] & 0x1f) != 0) {
	add_note(wt, MSG_INFO, "CCMP frame from " MACSTR
	" used non-zero reserved bit",
	MAC2STR(hdr->addr2));
	}
	}

	keyid = data[3] >> 6;
	if (keyid != 0) {
	add_note(wt, MSG_INFO, "Unexpected non-zero KeyID %d in "
	"individually addressed Data frame from " MACSTR,
	keyid, MAC2STR(hdr->addr2));
	}

	if (qos) {
	tid = qos[0] & 0x0f;
	if (fc & WLAN_FC_TODS)
	sta->tx_tid[tid]++;
	else
	sta->rx_tid[tid]++;
	} else {
	tid = 0;
	if (fc & WLAN_FC_TODS)
	sta->tx_tid[16]++;
	else
	sta->rx_tid[16]++;
	}
	if (tk) {
	if (os_memcmp(hdr->addr2, tdls->init->addr, ETH_ALEN) == 0)
	rsc = tdls->rsc_init[tid];
	else
	rsc = tdls->rsc_resp[tid];
	} else if (fc & WLAN_FC_TODS)
	rsc = sta->rsc_tods[tid];
	else
	rsc = sta->rsc_fromds[tid];


	if (tk == NULL && sta->pairwise_cipher == WPA_CIPHER_TKIP)
	tkip_get_pn(pn, data);
	else if (sta->pairwise_cipher == WPA_CIPHER_WEP40)
	goto skip_replay_det;
	else
	ccmp_get_pn(pn, data);
	if (os_memcmp(pn, rsc, 6) <= 0) {
	u16 seq_ctrl = le_to_host16(hdr->seq_ctrl);
	add_note(wt, MSG_INFO, "CCMP/TKIP replay detected: A1=" MACSTR
	" A2=" MACSTR " A3=" MACSTR " seq=%u frag=%u%s",
	MAC2STR(hdr->addr1), MAC2STR(hdr->addr2),
	MAC2STR(hdr->addr3),
	WLAN_GET_SEQ_SEQ(seq_ctrl),
	WLAN_GET_SEQ_FRAG(seq_ctrl),
	(le_to_host16(hdr->frame_control) & WLAN_FC_RETRY) ?
	" Retry" : "");
	wpa_hexdump(MSG_INFO, "RX PN", pn, 6);
	wpa_hexdump(MSG_INFO, "RSC", rsc, 6);
	}

	skip_replay_det:
	if (tk) {
	if (sta->pairwise_cipher == WPA_CIPHER_CCMP_256)
	decrypted = ccmp_256_decrypt(tk, hdr, data, len, &dlen);
	else if (sta->pairwise_cipher == WPA_CIPHER_GCMP \|\|
	sta->pairwise_cipher == WPA_CIPHER_GCMP_256)
	decrypted = gcmp_decrypt(tk, sta->tk_len, hdr, data,
	len, &dlen);
	else
	decrypted = ccmp_decrypt(tk, hdr, data, len, &dlen);
	} else if (sta->pairwise_cipher == WPA_CIPHER_TKIP) {
	decrypted = tkip_decrypt(sta->ptk.tk, hdr, data, len, &dlen);
	} else if (sta->pairwise_cipher == WPA_CIPHER_WEP40) {
	decrypted = wep_decrypt(wt, hdr, data, len, &dlen);
	} else if (sta->ptk_set) {
	if (sta->pairwise_cipher == WPA_CIPHER_CCMP_256)
	decrypted = ccmp_256_decrypt(sta->ptk.tk, hdr, data,
	len, &dlen);
	else if (sta->pairwise_cipher == WPA_CIPHER_GCMP \|\|
	sta->pairwise_cipher == WPA_CIPHER_GCMP_256)
	decrypted = gcmp_decrypt(sta->ptk.tk, sta->tk_len,
	hdr, data, len, &dlen);
	else
	decrypted = ccmp_decrypt(sta->ptk.tk, hdr, data, len,
	&dlen);
	} else {
	decrypted = try_all_ptk(wt, sta->pairwise_cipher, hdr, data,
	len, &dlen);
	ptk_iter_done = 1;
	}
	if (!decrypted && !ptk_iter_done) {
	decrypted = try_all_ptk(wt, sta->pairwise_cipher, hdr, data,
	len, &dlen);
	if (decrypted) {
	add_note(wt, MSG_DEBUG, "Current PTK did not work, but found a match from all known PTKs");
	}
	}
	if (decrypted) {
	u16 fc = le_to_host16(hdr->frame_control);
	const u8 *peer_addr = NULL;
	if (!(fc & (WLAN_FC_FROMDS \| WLAN_FC_TODS)))
	peer_addr = hdr->addr1;
	os_memcpy(rsc, pn, 6);
	rx_data_process(wt, bss->bssid, sta->addr, dst, src, decrypted,
	dlen, 1, peer_addr);
	write_pcap_decrypted(wt, (const u8 *) hdr, 24 + (qos ? 2 : 0),
	decrypted, dlen);
	} else if (!try_ptk_iter)
	add_note(wt, MSG_DEBUG, "Failed to decrypt frame");
	os_free(decrypted);
	}


	static void rx_data_bss(struct wlantest wt, const struct ieee80211_hdr hdr,
	const u8 qos, const u8 dst, const u8 *src,
	const u8 *data, size_t len)
	{
	u16 fc = le_to_host16(hdr->frame_control);
	int prot = !!(fc & WLAN_FC_ISWEP);

	if (qos) {
	u8 ack = (qos[0] & 0x60) >> 5;
	wpa_printf(MSG_MSGDUMP, "BSS DATA: " MACSTR " -> " MACSTR
	" len=%u%s tid=%u%s%s",
	MAC2STR(src), MAC2STR(dst), (unsigned int) len,
	prot ? " Prot" : "", qos[0] & 0x0f,
	(qos[0] & 0x10) ? " EOSP" : "",
	ack == 0 ? "" :
	(ack == 1 ? " NoAck" :
	(ack == 2 ? " NoExpAck" : " BA")));
	} else {
	wpa_printf(MSG_MSGDUMP, "BSS DATA: " MACSTR " -> " MACSTR
	" len=%u%s",
	MAC2STR(src), MAC2STR(dst), (unsigned int) len,
	prot ? " Prot" : "");
	}

	if (prot)
	rx_data_bss_prot(wt, hdr, qos, dst, src, data, len);
	else {
	const u8 bssid, sta_addr, *peer_addr;
	struct wlantest_bss *bss;

	if (fc & WLAN_FC_TODS) {
	bssid = hdr->addr1;
	sta_addr = hdr->addr2;
	peer_addr = NULL;
	} else if (fc & WLAN_FC_FROMDS) {
	bssid = hdr->addr2;
	sta_addr = hdr->addr1;
	peer_addr = NULL;
	} else {
	bssid = hdr->addr3;
	sta_addr = hdr->addr2;
	peer_addr = hdr->addr1;
	}

	bss = bss_get(wt, bssid);
	if (bss) {
	struct wlantest_sta *sta = sta_get(bss, sta_addr);

	if (sta) {
	if (qos) {
	int tid = qos[0] & 0x0f;
	if (fc & WLAN_FC_TODS)
	sta->tx_tid[tid]++;
	else
	sta->rx_tid[tid]++;
	} else {
	if (fc & WLAN_FC_TODS)
	sta->tx_tid[16]++;
	else
	sta->rx_tid[16]++;
	}
	}
	}

	rx_data_process(wt, bssid, sta_addr, dst, src, data, len, 0,
	peer_addr);
	}
	}


	static struct wlantest_tdls * get_tdls(struct wlantest wt, const u8 bssid,
	const u8 *sta1_addr,
	const u8 *sta2_addr)
	{
	struct wlantest_bss *bss;
	struct wlantest_sta sta1, sta2;
	struct wlantest_tdls tdls, found = NULL;

	bss = bss_find(wt, bssid);
	if (bss == NULL)
	return NULL;
	sta1 = sta_find(bss, sta1_addr);
	if (sta1 == NULL)
	return NULL;
	sta2 = sta_find(bss, sta2_addr);
	if (sta2 == NULL)
	return NULL;

	dl_list_for_each(tdls, &bss->tdls, struct wlantest_tdls, list) {
	if ((tdls->init == sta1 && tdls->resp == sta2) \|\|
	(tdls->init == sta2 && tdls->resp == sta1)) {
	found = tdls;
	if (tdls->link_up)
	break;
	}
	}

	return found;
	}


	static void add_direct_link(struct wlantest wt, const u8 bssid,
	const u8 sta1_addr, const u8 sta2_addr)
	{
	struct wlantest_tdls *tdls;

	tdls = get_tdls(wt, bssid, sta1_addr, sta2_addr);
	if (tdls == NULL)
	return;

	if (tdls->link_up)
	tdls->counters[WLANTEST_TDLS_COUNTER_VALID_DIRECT_LINK]++;
	else
	tdls->counters[WLANTEST_TDLS_COUNTER_INVALID_DIRECT_LINK]++;
	}


	static void add_ap_path(struct wlantest wt, const u8 bssid,
	const u8 sta1_addr, const u8 sta2_addr)
	{
	struct wlantest_tdls *tdls;

	tdls = get_tdls(wt, bssid, sta1_addr, sta2_addr);
	if (tdls == NULL)
	return;

	if (tdls->link_up)
	tdls->counters[WLANTEST_TDLS_COUNTER_INVALID_AP_PATH]++;
	else
	tdls->counters[WLANTEST_TDLS_COUNTER_VALID_AP_PATH]++;
	}


	void rx_data(struct wlantest wt, const u8 data, size_t len)
	{
	const struct ieee80211_hdr *hdr;
	u16 fc, stype;
	size_t hdrlen;
	const u8 *qos = NULL;

	if (len < 24)
	return;

	hdr = (const struct ieee80211_hdr *) data;
	fc = le_to_host16(hdr->frame_control);
	stype = WLAN_FC_GET_STYPE(fc);
	hdrlen = 24;
	if ((fc & (WLAN_FC_TODS \| WLAN_FC_FROMDS)) ==
	(WLAN_FC_TODS \| WLAN_FC_FROMDS))
	hdrlen += ETH_ALEN;
	if (stype & 0x08) {
	qos = data + hdrlen;
	hdrlen += 2;
	}
	if (len < hdrlen)
	return;
	wt->rx_data++;

	switch (fc & (WLAN_FC_TODS \| WLAN_FC_FROMDS)) {
	case 0:
	wpa_printf(MSG_EXCESSIVE, "DATA %s%s%s IBSS DA=" MACSTR " SA="
	MACSTR " BSSID=" MACSTR,
	data_stype(WLAN_FC_GET_STYPE(fc)),
	fc & WLAN_FC_PWRMGT ? " PwrMgt" : "",
	fc & WLAN_FC_ISWEP ? " Prot" : "",
	MAC2STR(hdr->addr1), MAC2STR(hdr->addr2),
	MAC2STR(hdr->addr3));
	add_direct_link(wt, hdr->addr3, hdr->addr1, hdr->addr2);
	rx_data_bss(wt, hdr, qos, hdr->addr1, hdr->addr2,
	data + hdrlen, len - hdrlen);
	break;
	case WLAN_FC_FROMDS:
	wpa_printf(MSG_EXCESSIVE, "DATA %s%s%s FromDS DA=" MACSTR
	" BSSID=" MACSTR " SA=" MACSTR,
	data_stype(WLAN_FC_GET_STYPE(fc)),
	fc & WLAN_FC_PWRMGT ? " PwrMgt" : "",
	fc & WLAN_FC_ISWEP ? " Prot" : "",
	MAC2STR(hdr->addr1), MAC2STR(hdr->addr2),
	MAC2STR(hdr->addr3));
	add_ap_path(wt, hdr->addr2, hdr->addr1, hdr->addr3);
	rx_data_bss(wt, hdr, qos, hdr->addr1, hdr->addr3,
	data + hdrlen, len - hdrlen);
	break;
	case WLAN_FC_TODS:
	wpa_printf(MSG_EXCESSIVE, "DATA %s%s%s ToDS BSSID=" MACSTR
	" SA=" MACSTR " DA=" MACSTR,
	data_stype(WLAN_FC_GET_STYPE(fc)),
	fc & WLAN_FC_PWRMGT ? " PwrMgt" : "",
	fc & WLAN_FC_ISWEP ? " Prot" : "",
	MAC2STR(hdr->addr1), MAC2STR(hdr->addr2),
	MAC2STR(hdr->addr3));
	add_ap_path(wt, hdr->addr1, hdr->addr3, hdr->addr2);
	rx_data_bss(wt, hdr, qos, hdr->addr3, hdr->addr2,
	data + hdrlen, len - hdrlen);
	break;
	case WLAN_FC_TODS \| WLAN_FC_FROMDS:
	wpa_printf(MSG_EXCESSIVE, "DATA %s%s%s WDS RA=" MACSTR " TA="
	MACSTR " DA=" MACSTR " SA=" MACSTR,
	data_stype(WLAN_FC_GET_STYPE(fc)),
	fc & WLAN_FC_PWRMGT ? " PwrMgt" : "",
	fc & WLAN_FC_ISWEP ? " Prot" : "",
	MAC2STR(hdr->addr1), MAC2STR(hdr->addr2),
	MAC2STR(hdr->addr3),
	MAC2STR((const u8 *) (hdr + 1)));
	break;
	}
	}