hostapd/wlantest/rx_data.c

/*
 * Received Data frame processing
 * Copyright (c) 2010, Jouni Malinen <j@w1.fi>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Alternatively, this software may be distributed under the terms of BSD
 * license.
 *
 * See README and COPYING for more details.
 */

#include "utils/includes.h"

#include "utils/common.h"
#include "common/ieee802_11_defs.h"
#include "common/eapol_common.h"
#include "common/wpa_common.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 int check_mic(const u8 *kck, int ver, const u8 *data, size_t len)
{
	u8 *buf;
	int ret = -1;
	struct ieee802_1x_hdr *hdr;
	struct wpa_eapol_key *key;
	u8 rx_mic[16];

	buf = os_malloc(len);
	if (buf == NULL)
		return -1;
	os_memcpy(buf, data, len);
	hdr = (struct ieee802_1x_hdr *) buf;
	key = (struct wpa_eapol_key *) (hdr + 1);

	os_memcpy(rx_mic, key->key_mic, 16);
	os_memset(key->key_mic, 0, 16);

	if (wpa_eapol_key_mic(kck, ver, buf, len, key->key_mic) == 0 &&
	    os_memcmp(rx_mic, key->key_mic, 16) == 0)
		ret = 0;

	os_free(buf);

	return ret;
}


static void rx_data_eapol_key_1_of_4(struct wlantest *wt, const u8 *dst,
				     const u8 *src, const u8 *data, size_t len)
{
	struct wlantest_bss *bss;
	struct wlantest_sta *sta;
	const struct ieee802_1x_hdr *eapol;
	const struct wpa_eapol_key *hdr;

	wpa_printf(MSG_DEBUG, "EAPOL-Key 1/4 " MACSTR " -> " MACSTR,
		   MAC2STR(src), MAC2STR(dst));
	bss = bss_get(wt, src);
	if (bss == NULL)
		return;
	sta = sta_get(bss, dst);
	if (sta == NULL)
		return;

	eapol = (const struct ieee802_1x_hdr *) data;
	hdr = (const struct wpa_eapol_key *) (eapol + 1);
	os_memcpy(sta->anonce, hdr->key_nonce, WPA_NONCE_LEN);
}


static void derive_ptk(struct wlantest_bss *bss, struct wlantest_sta *sta,
		       u16 ver, const u8 *data, size_t len)
{
	struct wlantest_pmk *pmk;

	dl_list_for_each(pmk, &bss->pmk, struct wlantest_pmk, list) {
		struct wpa_ptk ptk;
		size_t ptk_len = 48; /* FIX: 64 for TKIP */
		wpa_pmk_to_ptk(pmk->pmk, sizeof(pmk->pmk),
			       "Pairwise key expansion",
			       bss->bssid, sta->addr, sta->anonce, sta->snonce,
			       (u8 *) &ptk, ptk_len,
			       0 /* FIX: SHA256 based on AKM */);
		if (check_mic(ptk.kck, ver,
			      data, len) < 0)
			continue;

		wpa_printf(MSG_INFO, "Derived PTK for STA " MACSTR " BSSID "
			   MACSTR ")",
			   MAC2STR(sta->addr), MAC2STR(bss->bssid));
		os_memcpy(&sta->ptk, &ptk, sizeof(ptk));
		sta->ptk_set = 1;
		break;
	}
}


static void rx_data_eapol_key_2_of_4(struct wlantest *wt, const u8 *dst,
				     const u8 *src, const u8 *data, size_t len)
{
	struct wlantest_bss *bss;
	struct wlantest_sta *sta;
	const struct ieee802_1x_hdr *eapol;
	const struct wpa_eapol_key *hdr;
	u16 key_info;

	wpa_printf(MSG_DEBUG, "EAPOL-Key 2/4 " MACSTR " -> " MACSTR,
		   MAC2STR(src), MAC2STR(dst));
	bss = bss_get(wt, dst);
	if (bss == NULL)
		return;
	sta = sta_get(bss, src);
	if (sta == NULL)
		return;

	eapol = (const struct ieee802_1x_hdr *) data;
	hdr = (const struct wpa_eapol_key *) (eapol + 1);
	os_memcpy(sta->snonce, hdr->key_nonce, WPA_NONCE_LEN);
	key_info = WPA_GET_BE16(hdr->key_info);
	derive_ptk(bss, sta, key_info & WPA_KEY_INFO_TYPE_MASK, data, len);
}


static void rx_data_eapol_key_3_of_4(struct wlantest *wt, const u8 *dst,
				     const u8 *src, const u8 *data, size_t len)
{
	struct wlantest_bss *bss;
	struct wlantest_sta *sta;
	const struct ieee802_1x_hdr *eapol;
	const struct wpa_eapol_key *hdr;
	int recalc = 0;
	u16 key_info;

	wpa_printf(MSG_DEBUG, "EAPOL-Key 3/4 " MACSTR " -> " MACSTR,
		   MAC2STR(src), MAC2STR(dst));
	bss = bss_get(wt, src);
	if (bss == NULL)
		return;
	sta = sta_get(bss, dst);
	if (sta == NULL)
		return;

	eapol = (const struct ieee802_1x_hdr *) data;
	hdr = (const struct wpa_eapol_key *) (eapol + 1);
	key_info = WPA_GET_BE16(hdr->key_info);
	if (os_memcmp(sta->anonce, hdr->key_nonce, WPA_NONCE_LEN) != 0) {
		wpa_printf(MSG_INFO, "EAPOL-Key ANonce mismatch between 1/4 "
			   "and 3/4");
		recalc = 1;
	}
	os_memcpy(sta->anonce, hdr->key_nonce, WPA_NONCE_LEN);
	if (recalc) {
		derive_ptk(bss, sta, key_info & WPA_KEY_INFO_TYPE_MASK,
			   data, len);
	}

	if (!sta->ptk_set) {
		wpa_printf(MSG_DEBUG, "No PTK known to process EAPOL-Key 3/4");
		return;
	}

	if (check_mic(sta->ptk.kck, key_info & WPA_KEY_INFO_TYPE_MASK,
		      data, len) < 0) {
		wpa_printf(MSG_INFO, "Mismatch in EAPOL-Key 3/4 MIC");
		return;
	}
	wpa_printf(MSG_DEBUG, "Valid MIC found in EAPOL-Key 3/4");

	/* TODO: decrypt Key Data and store GTK, IGTK */
}


static void rx_data_eapol_key_4_of_4(struct wlantest *wt, const u8 *dst,
				     const u8 *src, const u8 *data, size_t len)
{
	struct wlantest_bss *bss;
	struct wlantest_sta *sta;
	const struct ieee802_1x_hdr *eapol;
	const struct wpa_eapol_key *hdr;
	u16 key_info;

	wpa_printf(MSG_DEBUG, "EAPOL-Key 4/4 " MACSTR " -> " MACSTR,
		   MAC2STR(src), MAC2STR(dst));
	bss = bss_get(wt, dst);
	if (bss == NULL)
		return;
	sta = sta_get(bss, src);
	if (sta == NULL)
		return;

	eapol = (const struct ieee802_1x_hdr *) data;
	hdr = (const struct wpa_eapol_key *) (eapol + 1);
	key_info = WPA_GET_BE16(hdr->key_info);

	if (!sta->ptk_set) {
		wpa_printf(MSG_DEBUG, "No PTK known to process EAPOL-Key 4/4");
		return;
	}

	if (sta->ptk_set &&
	    check_mic(sta->ptk.kck, key_info & WPA_KEY_INFO_TYPE_MASK,
		      data, len) < 0) {
		wpa_printf(MSG_INFO, "Mismatch in EAPOL-Key 4/4 MIC");
		return;
	}
	wpa_printf(MSG_DEBUG, "Valid MIC found in EAPOL-Key 4/4");
}


static void rx_data_eapol_key_1_of_2(struct wlantest *wt, const u8 *dst,
				     const u8 *src, const u8 *data, size_t len)
{
	wpa_printf(MSG_DEBUG, "EAPOL-Key 1/2 " MACSTR " -> " MACSTR,
		   MAC2STR(src), MAC2STR(dst));
}


static void rx_data_eapol_key_2_of_2(struct wlantest *wt, const u8 *dst,
				     const u8 *src, const u8 *data, size_t len)
{
	wpa_printf(MSG_DEBUG, "EAPOL-Key 2/2 " MACSTR " -> " MACSTR,
		   MAC2STR(src), MAC2STR(dst));
}


static void rx_data_eapol_key(struct wlantest *wt, const u8 *dst,
			      const u8 *src, const u8 *data, size_t len,
			      int prot)
{
	const struct ieee802_1x_hdr *eapol;
	const struct wpa_eapol_key *hdr;
	u16 key_info, key_length, ver, key_data_length;

	eapol = (const struct ieee802_1x_hdr *) data;
	hdr = (const struct wpa_eapol_key *) (eapol + 1);

	wpa_hexdump(MSG_MSGDUMP, "EAPOL-Key",
		    (const u8 *) hdr, len - sizeof(*eapol));
	if (len < sizeof(*hdr)) {
		wpa_printf(MSG_INFO, "Too short EAPOL-Key frame from " MACSTR,
			   MAC2STR(src));
		return;
	}

	if (hdr->type == EAPOL_KEY_TYPE_RC4) {
		/* TODO: EAPOL-Key RC4 for WEP */
		return;
	}

	if (hdr->type != EAPOL_KEY_TYPE_RSN &&
	    hdr->type != EAPOL_KEY_TYPE_WPA) {
		wpa_printf(MSG_DEBUG, "Unsupported EAPOL-Key type %u",
			   hdr->type);
		return;
	}

	key_info = WPA_GET_BE16(hdr->key_info);
	key_length = WPA_GET_BE16(hdr->key_length);
	key_data_length = WPA_GET_BE16(hdr->key_data_length);
	ver = key_info & WPA_KEY_INFO_TYPE_MASK;
	wpa_printf(MSG_DEBUG, "EAPOL-Key ver=%u %c idx=%u%s%s%s%s%s%s%s%s "
		   "datalen=%u",
		   ver, key_info & WPA_KEY_INFO_KEY_TYPE ? 'P' : 'G',
		   (key_info & WPA_KEY_INFO_KEY_INDEX_MASK) >>
		   WPA_KEY_INFO_KEY_INDEX_SHIFT,
		   (key_info & WPA_KEY_INFO_INSTALL) ? " Install" : "",
		   (key_info & WPA_KEY_INFO_ACK) ? " ACK" : "",
		   (key_info & WPA_KEY_INFO_MIC) ? " MIC" : "",
		   (key_info & WPA_KEY_INFO_SECURE) ? " Secure" : "",
		   (key_info & WPA_KEY_INFO_ERROR) ? " Error" : "",
		   (key_info & WPA_KEY_INFO_REQUEST) ? " Request" : "",
		   (key_info & WPA_KEY_INFO_ENCR_KEY_DATA) ? " Encr" : "",
		   (key_info & WPA_KEY_INFO_SMK_MESSAGE) ? " SMK" : "",
		   key_data_length);

	if (ver != WPA_KEY_INFO_TYPE_HMAC_MD5_RC4 &&
	    ver != WPA_KEY_INFO_TYPE_HMAC_SHA1_AES &&
	    ver != WPA_KEY_INFO_TYPE_AES_128_CMAC) {
		wpa_printf(MSG_DEBUG, "Unsupported EAPOL-Key Key Descriptor "
			   "Version %u", ver);
		return;
	}

	wpa_hexdump(MSG_MSGDUMP, "EAPOL-Key Replay Counter",
		    hdr->replay_counter, WPA_REPLAY_COUNTER_LEN);
	wpa_hexdump(MSG_MSGDUMP, "EAPOL-Key Key Nonce",
		    hdr->key_nonce, WPA_NONCE_LEN);
	wpa_hexdump(MSG_MSGDUMP, "EAPOL-Key Key IV",
		    hdr->key_iv, 16);
	wpa_hexdump(MSG_MSGDUMP, "EAPOL-Key RSC",
		    hdr->key_nonce, WPA_KEY_RSC_LEN);
	wpa_hexdump(MSG_MSGDUMP, "EAPOL-Key Key MIC",
		    hdr->key_mic, 16);

	if (key_info & (WPA_KEY_INFO_ERROR | WPA_KEY_INFO_REQUEST))
		return;

	if (key_info & WPA_KEY_INFO_SMK_MESSAGE)
		return;

	if (key_info & WPA_KEY_INFO_KEY_TYPE) {
		/* 4-Way Handshake */
		switch (key_info & (WPA_KEY_INFO_SECURE |
				    WPA_KEY_INFO_MIC |
				    WPA_KEY_INFO_ACK |
				    WPA_KEY_INFO_INSTALL)) {
		case WPA_KEY_INFO_ACK:
			rx_data_eapol_key_1_of_4(wt, dst, src, data, len);
			break;
		case WPA_KEY_INFO_MIC:
			rx_data_eapol_key_2_of_4(wt, dst, src, data, len);
			break;
		case WPA_KEY_INFO_SECURE | WPA_KEY_INFO_MIC |
			WPA_KEY_INFO_ACK | WPA_KEY_INFO_INSTALL:
			rx_data_eapol_key_3_of_4(wt, dst, src, data, len);
			break;
		case WPA_KEY_INFO_SECURE | WPA_KEY_INFO_MIC:
			rx_data_eapol_key_4_of_4(wt, dst, src, data, len);
			break;
		default:
			wpa_printf(MSG_DEBUG, "Unsupported EAPOL-Key frame");
			break;
		}
	} else {
		/* Group Key Handshake */
		switch (key_info & (WPA_KEY_INFO_SECURE |
				    WPA_KEY_INFO_MIC |
				    WPA_KEY_INFO_ACK)) {
		case WPA_KEY_INFO_SECURE | WPA_KEY_INFO_MIC |
			WPA_KEY_INFO_ACK:
			rx_data_eapol_key_1_of_2(wt, dst, src, data, len);
			break;
		case WPA_KEY_INFO_SECURE | WPA_KEY_INFO_MIC:
			rx_data_eapol_key_2_of_2(wt, dst, src, data, len);
			break;
		default:
			wpa_printf(MSG_DEBUG, "Unsupported EAPOL-Key frame");
			break;
		}
	}
}


static void rx_data_eapol(struct wlantest *wt, const u8 *dst, const u8 *src,
			  const u8 *data, size_t len, int prot)
{
	const struct ieee802_1x_hdr *hdr;
	u16 length;
	const u8 *p;

	wpa_hexdump(MSG_EXCESSIVE, "EAPOL", data, len);
	if (len < sizeof(*hdr)) {
		wpa_printf(MSG_INFO, "Too short EAPOL frame from " MACSTR,
			   MAC2STR(src));
		return;
	}

	hdr = (const struct ieee802_1x_hdr *) data;
	length = be_to_host16(hdr->length);
	wpa_printf(MSG_DEBUG, "RX EAPOL: " MACSTR " -> " MACSTR "%s ver=%u "
		   "type=%u len=%u",
		   MAC2STR(src), MAC2STR(dst), prot ? " Prot" : "",
		   hdr->version, hdr->type, length);
	if (sizeof(*hdr) + length > len) {
		wpa_printf(MSG_INFO, "Truncated EAPOL frame from " MACSTR,
			   MAC2STR(src));
		return;
	}

	if (sizeof(*hdr) + length < len) {
		wpa_printf(MSG_INFO, "EAPOL frame with %d extra bytes",
			   (int) (len - sizeof(*hdr) - length));
	}
	p = (const u8 *) (hdr + 1);

	switch (hdr->type) {
	case IEEE802_1X_TYPE_EAP_PACKET:
		wpa_hexdump(MSG_MSGDUMP, "EAPOL - EAP packet", p, length);
		break;
	case IEEE802_1X_TYPE_EAPOL_START:
		wpa_hexdump(MSG_MSGDUMP, "EAPOL-Start", p, length);
		break;
	case IEEE802_1X_TYPE_EAPOL_LOGOFF:
		wpa_hexdump(MSG_MSGDUMP, "EAPOL-Logoff", p, length);
		break;
	case IEEE802_1X_TYPE_EAPOL_KEY:
		rx_data_eapol_key(wt, dst, src, data, sizeof(*hdr) + length,
				  prot);
		break;
	case IEEE802_1X_TYPE_EAPOL_ENCAPSULATED_ASF_ALERT:
		wpa_hexdump(MSG_MSGDUMP, "EAPOL - Encapsulated ASF alert",
			    p, length);
		break;
	default:
		wpa_hexdump(MSG_MSGDUMP, "Unknown EAPOL payload", p, length);
		break;
	}
}


static void rx_data_eth(struct wlantest *wt, const u8 *dst, const u8 *src,
			u16 ethertype, const u8 *data, size_t len, int prot)
{
	if (ethertype == ETH_P_PAE)
		rx_data_eapol(wt, dst, src, data, len, prot);
}


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

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

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


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)
{
	/* TODO: Try to decrypt and if success, call rx_data_process() with
	 * prot = 1 */
}


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


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));
		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));
		rx_data_bss(wt, hdr, qos, hdr->addr1, hdr->addr2,
			    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));
		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;
	}
}