ieee80211_input.c

Linux下wifi实现

	case WPA_SEL(WPA_ASE_NONE):
		return WPA_ASE_NONE;
	}
	return 0;		/* NB: so is discarded */
#undef WPA_SEL
}

/*
 * Parse a WPA information element to collect parameters
 * and validate the parameters against what has been
 * configured for the system.
 */
static int
ieee80211_parse_wpa(struct ieee80211vap *vap, u_int8_t *frm,
	struct ieee80211_rsnparms *rsn_parm, const struct ieee80211_frame *wh)
{
	u_int8_t len = frm[1];
	u_int32_t w;
	int n;

	/*
	 * Check the length once for fixed parts: OUI, type,
	 * version, mcast cipher, and 2 selector counts.
	 * Other, variable-length data, must be checked separately.
	 */
	if (!(vap->iv_flags & IEEE80211_F_WPA1)) {
		IEEE80211_DISCARD_IE(vap,
			IEEE80211_MSG_ELEMID | IEEE80211_MSG_WPA,
			wh, "WPA", "vap not WPA, flags 0x%x", vap->iv_flags);
		return IEEE80211_REASON_IE_INVALID;
	}
	
	if (len < 14) {
		IEEE80211_DISCARD_IE(vap,
			IEEE80211_MSG_ELEMID | IEEE80211_MSG_WPA,
			wh, "WPA", "too short, len %u", len);
		return IEEE80211_REASON_IE_INVALID;
	}
	frm += 6, len -= 4;		/* NB: len is payload only */
	/* NB: iswapoui already validated the OUI and type */
	w = LE_READ_2(frm);
	if (w != WPA_VERSION) {
		IEEE80211_DISCARD_IE(vap,
			IEEE80211_MSG_ELEMID | IEEE80211_MSG_WPA,
			wh, "WPA", "bad version %u", w);
		return IEEE80211_REASON_IE_INVALID;
	}
	frm += 2;
	len -= 2;

	/* multicast/group cipher */
	w = wpa_cipher(frm, &rsn_parm->rsn_mcastkeylen);
	if (w != rsn_parm->rsn_mcastcipher) {
		IEEE80211_DISCARD_IE(vap,
			IEEE80211_MSG_ELEMID | IEEE80211_MSG_WPA,
			wh, "WPA", "mcast cipher mismatch; got %u, expected %u",
			w, rsn_parm->rsn_mcastcipher);
		return IEEE80211_REASON_IE_INVALID;
	}
	frm += 4;
	len -= 4;

	/* unicast ciphers */
	n = LE_READ_2(frm);
	frm += 2;
	len -= 2;
	if (len < n*4+2) {
		IEEE80211_DISCARD_IE(vap,
			IEEE80211_MSG_ELEMID | IEEE80211_MSG_WPA,
			wh, "WPA", "ucast cipher data too short; len %u, n %u",
			len, n);
		return IEEE80211_REASON_IE_INVALID;
	}
	w = 0;
	for (; n > 0; n--) {
		w |= 1 << wpa_cipher(frm, &rsn_parm->rsn_ucastkeylen);
		frm += 4;
		len -= 4;
	}
	w &= rsn_parm->rsn_ucastcipherset;
	if (w == 0) {
		IEEE80211_DISCARD_IE(vap,
			IEEE80211_MSG_ELEMID | IEEE80211_MSG_WPA,
			wh, "WPA", "%s", "ucast cipher set empty");
		return IEEE80211_REASON_IE_INVALID;
	}
	if (w & (1 << IEEE80211_CIPHER_TKIP))
		rsn_parm->rsn_ucastcipher = IEEE80211_CIPHER_TKIP;
	else
		rsn_parm->rsn_ucastcipher = IEEE80211_CIPHER_AES_CCM;

	/* key management algorithms */
	n = LE_READ_2(frm);
	frm += 2;
	len -= 2;
	if (len < n * 4) {
		IEEE80211_DISCARD_IE(vap,
			IEEE80211_MSG_ELEMID | IEEE80211_MSG_WPA,
			wh, "WPA", "key mgmt alg data too short; len %u, n %u",
			len, n);
		return IEEE80211_REASON_IE_INVALID;
	}
	w = 0;
	for (; n > 0; n--) {
		w |= wpa_keymgmt(frm);
		frm += 4;
		len -= 4;
	}
	w &= rsn_parm->rsn_keymgmtset;
	if (w == 0) {
		IEEE80211_DISCARD_IE(vap,
			IEEE80211_MSG_ELEMID | IEEE80211_MSG_WPA,
			wh, "WPA", "%s", "no acceptable key mgmt alg");
		return IEEE80211_REASON_IE_INVALID;
	}
	if (w & WPA_ASE_8021X_UNSPEC)
		rsn_parm->rsn_keymgmt = WPA_ASE_8021X_UNSPEC;
	else
		rsn_parm->rsn_keymgmt = WPA_ASE_8021X_PSK;

	if (len > 2)		/* optional capabilities */
		rsn_parm->rsn_caps = LE_READ_2(frm);

	return 0;
}

/*
 * Convert an RSN cipher selector OUI to an internal
 * cipher algorithm.  Where appropriate we also
 * record any key length.
 */
static int
rsn_cipher(u_int8_t *sel, u_int8_t *keylen)
{
#define	RSN_SEL(x)	(((x) << 24) | RSN_OUI)
	u_int32_t w = LE_READ_4(sel);

	switch (w) {
	case RSN_SEL(RSN_CSE_NULL):
		return IEEE80211_CIPHER_NONE;
	case RSN_SEL(RSN_CSE_WEP40):
		if (keylen)
			*keylen = 40 / NBBY;
		return IEEE80211_CIPHER_WEP;
	case RSN_SEL(RSN_CSE_WEP104):
		if (keylen)
			*keylen = 104 / NBBY;
		return IEEE80211_CIPHER_WEP;
	case RSN_SEL(RSN_CSE_TKIP):
		return IEEE80211_CIPHER_TKIP;
	case RSN_SEL(RSN_CSE_CCMP):
		return IEEE80211_CIPHER_AES_CCM;
	case RSN_SEL(RSN_CSE_WRAP):
		return IEEE80211_CIPHER_AES_OCB;
	}
	return 32;		/* NB: so 1<< is discarded */
#undef RSN_SEL
}

/*
 * Convert an RSN key management/authentication algorithm
 * to an internal code.
 */
static int
rsn_keymgmt(u_int8_t *sel)
{
#define	RSN_SEL(x)	(((x) << 24) | RSN_OUI)
	u_int32_t w = LE_READ_4(sel);

	switch (w) {
	case RSN_SEL(RSN_ASE_8021X_UNSPEC):
		return RSN_ASE_8021X_UNSPEC;
	case RSN_SEL(RSN_ASE_8021X_PSK):
		return RSN_ASE_8021X_PSK;
	case RSN_SEL(RSN_ASE_NONE):
		return RSN_ASE_NONE;
	}
	return 0;		/* NB: so is discarded */
#undef RSN_SEL
}

/*
 * Parse a WPA/RSN information element to collect parameters
 * and validate the parameters against what has been
 * configured for the system.
 */
static int
ieee80211_parse_rsn(struct ieee80211vap *vap, u_int8_t *frm,
	struct ieee80211_rsnparms *rsn_parm, const struct ieee80211_frame *wh)
{
	u_int8_t len = frm[1];
	u_int32_t w;
	int n;

	/*
	 * Check the length once for fixed parts: 
	 * version, mcast cipher, and 2 selector counts.
	 * Other, variable-length data, must be checked separately.
	 */
	if (!(vap->iv_flags & IEEE80211_F_WPA2)) {
		IEEE80211_DISCARD_IE(vap,
			IEEE80211_MSG_ELEMID | IEEE80211_MSG_WPA,
			wh, "RSN", "vap not RSN, flags 0x%x", vap->iv_flags);
		return IEEE80211_REASON_IE_INVALID;
	}
	
	if (len < 10) {
		IEEE80211_DISCARD_IE(vap,
			IEEE80211_MSG_ELEMID | IEEE80211_MSG_WPA,
			wh, "RSN", "too short, len %u", len);
		return IEEE80211_REASON_IE_INVALID;
	}
	frm += 2;
	w = LE_READ_2(frm);
	if (w != RSN_VERSION) {
		IEEE80211_DISCARD_IE(vap,
			IEEE80211_MSG_ELEMID | IEEE80211_MSG_WPA,
			wh, "RSN", "bad version %u", w);
		return IEEE80211_REASON_IE_INVALID;
	}
	frm += 2;
	len -= 2;

	/* multicast/group cipher */
	w = rsn_cipher(frm, &rsn_parm->rsn_mcastkeylen);
	if (w != rsn_parm->rsn_mcastcipher) {
		IEEE80211_DISCARD_IE(vap,
			IEEE80211_MSG_ELEMID | IEEE80211_MSG_WPA,
			wh, "RSN", "mcast cipher mismatch; got %u, expected %u",
			w, rsn_parm->rsn_mcastcipher);
		return IEEE80211_REASON_IE_INVALID;
	}
	frm += 4;
	len -= 4;

	/* unicast ciphers */
	n = LE_READ_2(frm);
	frm += 2;
	len -= 2;
	if (len < n * 4 + 2) {
		IEEE80211_DISCARD_IE(vap,
			IEEE80211_MSG_ELEMID | IEEE80211_MSG_WPA,
			wh, "RSN", "ucast cipher data too short; len %u, n %u",
			len, n);
		return IEEE80211_REASON_IE_INVALID;
	}
	w = 0;
	for (; n > 0; n--) {
		w |= 1 << rsn_cipher(frm, &rsn_parm->rsn_ucastkeylen);
		frm += 4;
		len -= 4;
	}
	w &= rsn_parm->rsn_ucastcipherset;
	if (w == 0) {
		IEEE80211_DISCARD_IE(vap,
			IEEE80211_MSG_ELEMID | IEEE80211_MSG_WPA,
			wh, "RSN", "%s", "ucast cipher set empty");
		return IEEE80211_REASON_IE_INVALID;
	}
	if (w & (1<<IEEE80211_CIPHER_TKIP))
		rsn_parm->rsn_ucastcipher = IEEE80211_CIPHER_TKIP;
	else
		rsn_parm->rsn_ucastcipher = IEEE80211_CIPHER_AES_CCM;

	/* key management algorithms */
	n = LE_READ_2(frm);
	frm += 2;
	len -= 2;
	if (len < n * 4) {
		IEEE80211_DISCARD_IE(vap, 
			IEEE80211_MSG_ELEMID | IEEE80211_MSG_WPA,
			wh, "RSN", "key mgmt alg data too short; len %u, n %u",
			len, n);
		return IEEE80211_REASON_IE_INVALID;
	}
	w = 0;
	for (; n > 0; n--) {
		w |= rsn_keymgmt(frm);
		frm += 4;
		len -= 4;
	}
	w &= rsn_parm->rsn_keymgmtset;
	if (w == 0) {
		IEEE80211_DISCARD_IE(vap,
			IEEE80211_MSG_ELEMID | IEEE80211_MSG_WPA,
			wh, "RSN", "%s", "no acceptable key mgmt alg");
		return IEEE80211_REASON_IE_INVALID;
	}
	if (w & RSN_ASE_8021X_UNSPEC)
		rsn_parm->rsn_keymgmt = RSN_ASE_8021X_UNSPEC;
	else
		rsn_parm->rsn_keymgmt = RSN_ASE_8021X_PSK;

	/* optional RSN capabilities */
	if (len > 2)
		rsn_parm->rsn_caps = LE_READ_2(frm);
	/* XXXPMKID */

	return 0;
}

void
ieee80211_saveie(u_int8_t **iep, const u_int8_t *ie)
{
	u_int ielen = ie[1] + 2;
	/*
	 * Record information element for later use.
	 */
	if (*iep == NULL || (*iep)[1] != ie[1]) {
		if (*iep != NULL)
			FREE(*iep, M_DEVBUF);
		MALLOC(*iep, void*, ielen, M_DEVBUF, M_NOWAIT);
	}
	if (*iep != NULL)
		memcpy(*iep, ie, ielen);
}
EXPORT_SYMBOL(ieee80211_saveie);

static int
ieee80211_parse_wmeie(u_int8_t *frm, const struct ieee80211_frame *wh, 
					  struct ieee80211_node *ni)
{
	u_int len = frm[1];

	if (len != 7) {
		IEEE80211_DISCARD_IE(ni->ni_vap,
			IEEE80211_MSG_ELEMID | IEEE80211_MSG_WME,
			wh, "WME IE", "too short, len %u", len);
		return -1;
	}
	ni->ni_uapsd = frm[WME_CAPINFO_IE_OFFSET];
	if (ni->ni_uapsd) {
		ni->ni_flags |= IEEE80211_NODE_UAPSD;
		switch (WME_UAPSD_MAXSP(ni->ni_uapsd)) {
		case 1: 
			ni->ni_uapsd_maxsp = 2; break;
		case 2: 
			ni->ni_uapsd_maxsp = 4; break;
		case 3: 
			ni->ni_uapsd_maxsp = 6; break;
		default:  
			ni->ni_uapsd_maxsp = WME_UAPSD_NODE_MAXQDEPTH;
		}
	}
	IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_POWER, ni,
		"UAPSD bit settings from STA: %02x", ni->ni_uapsd);

	return 1;
}

static int
ieee80211_parse_wmeparams(struct ieee80211vap *vap, u_int8_t *frm,
	const struct ieee80211_frame *wh, u_int8_t *qosinfo)
{
#define	MS(_v, _f)	(((_v) & _f) >> _f##_S)
	struct ieee80211_wme_state *wme = &vap->iv_ic->ic_wme;
	u_int len = frm[1], qosinfo_count;
	int i;

	*qosinfo = 0;

	if (len < sizeof(struct ieee80211_wme_param)-2) {
		IEEE80211_DISCARD_IE(vap,
			IEEE80211_MSG_ELEMID | IEEE80211_MSG_WME,
			wh, "WME", "too short, len %u", len);
		return -1;
	}
	*qosinfo = frm[__offsetof(struct ieee80211_wme_param, param_qosInfo)];
	qosinfo_count = *qosinfo & WME_QOSINFO_COUNT;
	/* XXX do proper check for wraparound */
	if (qosinfo_count == wme->wme_wmeChanParams.cap_info_count)
		return 0;
	frm += __offsetof(struct ieee80211_wme_param, params_acParams);
	for (i = 0; i < WME_NUM_AC; i++) {
		struct wmeParams *wmep =
			&wme->wme_wmeChanParams.cap_wmeParams[i];
		/* NB: ACI not used */
		wmep->wmep_acm = MS(frm[0], WME_PARAM_ACM);
		wmep->wmep_aifsn = MS(frm[0], WME_PARAM_AIFSN);
		wmep->wmep_logcwmin = MS(frm[1], WME_PARAM_LOGCWMIN);
		wmep->wmep_logcwmax = MS(frm[1], WME_PARAM_LOGCWMAX);
		wmep->wmep_txopLimit = LE_READ_2(frm + 2);
		frm += 4;
	}
	wme->wme_wmeChanParams.cap_info_count = qosinfo_count;
	return 1;
#undef MS
}

static void
ieee80211_parse_athParams(struct ieee80211_node *ni, u_int8_t *ie)
{
	struct ieee80211vap *vap = ni->ni_vap;
	struct ieee80211com *ic = ni->ni_ic;
	struct ieee80211_ie_athAdvCap *athIe =
		(struct ieee80211_ie_athAdvCap *) ie;

	ni->ni_ath_flags = athIe->athAdvCap_capability;
	if (ni->ni_ath_flags & IEEE80211_ATHC_COMP)
		ni->ni_ath_defkeyindex = LE_READ_2(&athIe->athAdvCap_defKeyIndex);
#if 0
	/* NB: too noisy */
	IEEE80211_NOTE(vap, IEEE80211_MSG_SUPG, ni,
		"recv ath params: caps 0x%x flags 0x%x defkeyix %u",
		athIe->athAdvCap_capability, ni->ni_ath_flags,
		ni->ni_ath_defkeyindex);
#endif
#ifdef ATH_SUPERG_DYNTURBO
	if (IEEE80211_ATH_CAP(vap, ni, IEEE80211_ATHC_TURBOP)) {
		u_int16_t curflags, newflags;

		/*
		 * Check for turbo mode switch.  Calculate flags
		 * for the new mode and effect the switch.
		 */
		newflags = curflags = ic->ic_bsschan->ic_flags;
		/* NB: ATHC_BOOST is not in ic_ath_cap, so get it from the ie */
		if (athIe->athAdvCap_capability & IEEE80211_ATHC_BOOST) 
			newflags |= IEEE80211_CHAN_TURBO;
		else
			newflags &= ~IEEE80211_CHAN_TURBO;
		if (newflags != curflags)
			ieee80211_dturbo_switch(ic, newflags);
	}
#endif /* ATH_SUPERG_DYNTURBO */
}

void
ieee80211_saveath(struct ieee80211_node *ni, u_int8_t *ie)
{
	const struct ieee80211_ie_athAdvCap *athIe =
		(const struct ieee80211_ie_athAdvCap *) ie;

	ni->ni_ath_flags = athIe->athAdvCap_capability;
	if (ni->ni_ath_flags & IEEE80211_ATHC_COMP)
		ni->ni_ath_defkeyindex = LE_READ_2(&athIe->athAdvCap_defKeyIndex);
	ieee80211_saveie(&ni->ni_ath_ie, ie);
}

struct ieee80211_channel *
ieee80211_doth_findchan(struct ieee80211vap *vap, u_int8_t chan)
{