driver_wext.c

一个Linux下无线网卡的设置工具

 * This function uses SIOCSIWENCODEEXT by default, but tries to use
 * SIOCSIWENCODE if the extended ioctl fails when configuring a WEP key.
 */
int wpa_driver_wext_set_key(void *priv, wpa_alg alg,
			    const u8 *addr, int key_idx,
			    int set_tx, const u8 *seq, size_t seq_len,
			    const u8 *key, size_t key_len)
{
	struct wpa_driver_wext_data *drv = priv;
	struct iwreq iwr;
	int ret = 0;

	wpa_printf(MSG_DEBUG, "%s: alg=%d key_idx=%d set_tx=%d seq_len=%lu "
		   "key_len=%lu",
		   __FUNCTION__, alg, key_idx, set_tx,
		   (unsigned long) seq_len, (unsigned long) key_len);

	ret = wpa_driver_wext_set_key_ext(drv, alg, addr, key_idx, set_tx,
					  seq, seq_len, key, key_len);
	if (ret == 0)
		return 0;

	if (ret == -2 &&
	    (alg == WPA_ALG_NONE || alg == WPA_ALG_WEP)) {
		wpa_printf(MSG_DEBUG, "Driver did not support "
			   "SIOCSIWENCODEEXT, trying SIOCSIWENCODE");
		ret = 0;
	} else {
		wpa_printf(MSG_DEBUG, "Driver did not support "
			   "SIOCSIWENCODEEXT");
		return ret;
	}

	memset(&iwr, 0, sizeof(iwr));
	strncpy(iwr.ifr_name, drv->ifname, IFNAMSIZ);
	iwr.u.encoding.flags = key_idx + 1;
	if (alg == WPA_ALG_NONE)
		iwr.u.encoding.flags |= IW_ENCODE_DISABLED;
	iwr.u.encoding.pointer = (caddr_t) key;
	iwr.u.encoding.length = key_len;

	if (ioctl(drv->ioctl_sock, SIOCSIWENCODE, &iwr) < 0) {
		perror("ioctl[SIOCSIWENCODE]");
		ret = -1;
	}

	if (set_tx && alg != WPA_ALG_NONE) {
		memset(&iwr, 0, sizeof(iwr));
		strncpy(iwr.ifr_name, drv->ifname, IFNAMSIZ);
		iwr.u.encoding.flags = key_idx + 1;
		iwr.u.encoding.pointer = (caddr_t) key;
		iwr.u.encoding.length = 0;
		if (ioctl(drv->ioctl_sock, SIOCSIWENCODE, &iwr) < 0) {
			perror("ioctl[SIOCSIWENCODE] (set_tx)");
			ret = -1;
		}
	}

	return ret;
}


static int wpa_driver_wext_set_countermeasures(void *priv,
					       int enabled)
{
	struct wpa_driver_wext_data *drv = priv;
	wpa_printf(MSG_DEBUG, "%s", __FUNCTION__);
	return wpa_driver_wext_set_auth_param(drv,
					      IW_AUTH_TKIP_COUNTERMEASURES,
					      enabled);
}


static int wpa_driver_wext_set_drop_unencrypted(void *priv,
						int enabled)
{
	struct wpa_driver_wext_data *drv = priv;
	wpa_printf(MSG_DEBUG, "%s", __FUNCTION__);
	drv->use_crypt = enabled;
	return wpa_driver_wext_set_auth_param(drv, IW_AUTH_DROP_UNENCRYPTED,
					      enabled);
}


static int wpa_driver_wext_mlme(struct wpa_driver_wext_data *drv,
				const u8 *addr, int cmd, int reason_code)
{
	struct iwreq iwr;
	struct iw_mlme mlme;
	int ret = 0;

	memset(&iwr, 0, sizeof(iwr));
	strncpy(iwr.ifr_name, drv->ifname, IFNAMSIZ);
	memset(&mlme, 0, sizeof(mlme));
	mlme.cmd = cmd;
	mlme.reason_code = reason_code;
	mlme.addr.sa_family = ARPHRD_ETHER;
	memcpy(mlme.addr.sa_data, addr, ETH_ALEN);
	iwr.u.data.pointer = (caddr_t) &mlme;
	iwr.u.data.length = sizeof(mlme);

	if (ioctl(drv->ioctl_sock, SIOCSIWMLME, &iwr) < 0) {
		perror("ioctl[SIOCSIWMLME]");
		ret = -1;
	}

	return ret;
}


static int wpa_driver_wext_deauthenticate(void *priv, const u8 *addr,
					  int reason_code)
{
	struct wpa_driver_wext_data *drv = priv;
	wpa_printf(MSG_DEBUG, "%s", __FUNCTION__);
	return wpa_driver_wext_mlme(drv, addr, IW_MLME_DEAUTH, reason_code);
}


static int wpa_driver_wext_disassociate(void *priv, const u8 *addr,
					int reason_code)
{
	struct wpa_driver_wext_data *drv = priv;
	wpa_printf(MSG_DEBUG, "%s", __FUNCTION__);
	return wpa_driver_wext_mlme(drv, addr, IW_MLME_DISASSOC,
				    reason_code);
}


static int wpa_driver_wext_set_gen_ie(void *priv, const u8 *ie,
				      size_t ie_len)
{
	struct wpa_driver_wext_data *drv = priv;
	struct iwreq iwr;
	int ret = 0;

	memset(&iwr, 0, sizeof(iwr));
	strncpy(iwr.ifr_name, drv->ifname, IFNAMSIZ);
	iwr.u.data.pointer = (caddr_t) ie;
	iwr.u.data.length = ie_len;

	if (ioctl(drv->ioctl_sock, SIOCSIWGENIE, &iwr) < 0) {
		perror("ioctl[SIOCSIWGENIE]");
		ret = -1;
	}

	return ret;
}


static int wpa_driver_wext_cipher2wext(int cipher)
{
	switch (cipher) {
	case CIPHER_NONE:
		return IW_AUTH_CIPHER_NONE;
	case CIPHER_WEP40:
		return IW_AUTH_CIPHER_WEP40;
	case CIPHER_TKIP:
		return IW_AUTH_CIPHER_TKIP;
	case CIPHER_CCMP:
		return IW_AUTH_CIPHER_CCMP;
	case CIPHER_WEP104:
		return IW_AUTH_CIPHER_WEP104;
	default:
		return 0;
	}
}


static int wpa_driver_wext_keymgmt2wext(int keymgmt)
{
	switch (keymgmt) {
	case KEY_MGMT_802_1X:
		return IW_AUTH_KEY_MGMT_802_1X;
	case KEY_MGMT_PSK:
		return IW_AUTH_KEY_MGMT_PSK;
	default:
		return 0;
	}
}


static int
wpa_driver_wext_auth_alg_fallback(struct wpa_driver_wext_data *drv,
				  struct wpa_driver_associate_params *params)
{
	struct iwreq iwr;
	int ret = 0;

	wpa_printf(MSG_DEBUG, "WEXT: Driver did not support "
		   "SIOCSIWAUTH for AUTH_ALG, trying SIOCSIWENCODE");

	memset(&iwr, 0, sizeof(iwr));
	strncpy(iwr.ifr_name, drv->ifname, IFNAMSIZ);
	/* Just changing mode, not actual keys */
	iwr.u.encoding.flags = 0;
	iwr.u.encoding.pointer = (caddr_t) NULL;
	iwr.u.encoding.length = 0;

	/*
	 * Note: IW_ENCODE_{OPEN,RESTRICTED} can be interpreted to mean two
	 * different things. Here they are used to indicate Open System vs.
	 * Shared Key authentication algorithm. However, some drivers may use
	 * them to select between open/restricted WEP encrypted (open = allow
	 * both unencrypted and encrypted frames; restricted = only allow
	 * encrypted frames).
	 */

	if (!drv->use_crypt) {
		iwr.u.encoding.flags |= IW_ENCODE_DISABLED;
	} else {
		if (params->auth_alg & AUTH_ALG_OPEN_SYSTEM)
			iwr.u.encoding.flags |= IW_ENCODE_OPEN;
		if (params->auth_alg & AUTH_ALG_SHARED_KEY)
			iwr.u.encoding.flags |= IW_ENCODE_RESTRICTED;
	}

	if (ioctl(drv->ioctl_sock, SIOCSIWENCODE, &iwr) < 0) {
		perror("ioctl[SIOCSIWENCODE]");
		ret = -1;
	}

	return ret;
}


static int
wpa_driver_wext_associate(void *priv,
			  struct wpa_driver_associate_params *params)
{
	struct wpa_driver_wext_data *drv = priv;
	int ret = 0;
	int allow_unencrypted_eapol;
	int value;

	wpa_printf(MSG_DEBUG, "%s", __FUNCTION__);

	/*
	 * If the driver did not support SIOCSIWAUTH, fallback to
	 * SIOCSIWENCODE here.
	 */
	if (drv->auth_alg_fallback &&
	    wpa_driver_wext_auth_alg_fallback(drv, params) < 0)
		ret = -1;

	if (!params->bssid &&
	    wpa_driver_wext_set_bssid(drv, NULL) < 0)
		ret = -1;

	if (wpa_driver_wext_set_mode(drv, params->mode) < 0)
		ret = -1;
	/* TODO: should consider getting wpa version and cipher/key_mgmt suites
	 * from configuration, not from here, where only the selected suite is
	 * available */
	if (wpa_driver_wext_set_gen_ie(drv, params->wpa_ie, params->wpa_ie_len)
	    < 0)
		ret = -1;
	if (params->wpa_ie == NULL || params->wpa_ie_len == 0)
		value = IW_AUTH_WPA_VERSION_DISABLED;
	else if (params->wpa_ie[0] == RSN_INFO_ELEM)
		value = IW_AUTH_WPA_VERSION_WPA2;
	else
		value = IW_AUTH_WPA_VERSION_WPA;
	if (wpa_driver_wext_set_auth_param(drv,
					   IW_AUTH_WPA_VERSION, value) < 0)
		ret = -1;
	value = wpa_driver_wext_cipher2wext(params->pairwise_suite);
	if (wpa_driver_wext_set_auth_param(drv,
					   IW_AUTH_CIPHER_PAIRWISE, value) < 0)
		ret = -1;
	value = wpa_driver_wext_cipher2wext(params->group_suite);
	if (wpa_driver_wext_set_auth_param(drv,
					   IW_AUTH_CIPHER_GROUP, value) < 0)
		ret = -1;
	value = wpa_driver_wext_keymgmt2wext(params->key_mgmt_suite);
	if (wpa_driver_wext_set_auth_param(drv,
					   IW_AUTH_KEY_MGMT, value) < 0)
		ret = -1;
	value = params->key_mgmt_suite != KEY_MGMT_NONE ||
		params->pairwise_suite != CIPHER_NONE ||
		params->group_suite != CIPHER_NONE ||
		params->wpa_ie_len;
	if (wpa_driver_wext_set_auth_param(drv,
					   IW_AUTH_PRIVACY_INVOKED, value) < 0)
		ret = -1;

	/* Allow unencrypted EAPOL messages even if pairwise keys are set when
	 * not using WPA. IEEE 802.1X specifies that these frames are not
	 * encrypted, but WPA encrypts them when pairwise keys are in use. */
	if (params->key_mgmt_suite == KEY_MGMT_802_1X ||
	    params->key_mgmt_suite == KEY_MGMT_PSK)
		allow_unencrypted_eapol = 0;
	else
		allow_unencrypted_eapol = 1;
	
	if (wpa_driver_wext_set_auth_param(drv,
					   IW_AUTH_RX_UNENCRYPTED_EAPOL,
					   allow_unencrypted_eapol) < 0)
		ret = -1;
	if (params->freq && wpa_driver_wext_set_freq(drv, params->freq) < 0)
		ret = -1;
	if (wpa_driver_wext_set_ssid(drv, params->ssid, params->ssid_len) < 0)
		ret = -1;
	if (params->bssid &&
	    wpa_driver_wext_set_bssid(drv, params->bssid) < 0)
		ret = -1;

	return ret;
}


static int wpa_driver_wext_set_auth_alg(void *priv, int auth_alg)
{
	struct wpa_driver_wext_data *drv = priv;
	int algs = 0, res;

	if (auth_alg & AUTH_ALG_OPEN_SYSTEM)
		algs |= IW_AUTH_ALG_OPEN_SYSTEM;
	if (auth_alg & AUTH_ALG_SHARED_KEY)
		algs |= IW_AUTH_ALG_SHARED_KEY;
	if (auth_alg & AUTH_ALG_LEAP)
		algs |= IW_AUTH_ALG_LEAP;
	if (algs == 0) {
		/* at least one algorithm should be set */
		algs = IW_AUTH_ALG_OPEN_SYSTEM;
	}

	res = wpa_driver_wext_set_auth_param(drv, IW_AUTH_80211_AUTH_ALG,
					     algs);
	drv->auth_alg_fallback = res == -2;
	return res;
}


/**
 * wpa_driver_wext_set_mode - Set wireless mode (infra/adhoc), SIOCSIWMODE
 * @priv: Pointer to private wext data from wpa_driver_wext_init()
 * @mode: 0 = infra/BSS (associate with an AP), 1 = adhoc/IBSS
 * Returns: 0 on success, -1 on failure
 */
int wpa_driver_wext_set_mode(void *priv, int mode)
{
	struct wpa_driver_wext_data *drv = priv;
	struct iwreq iwr;
	int ret = 0;

	memset(&iwr, 0, sizeof(iwr));
	strncpy(iwr.ifr_name, drv->ifname, IFNAMSIZ);
	iwr.u.mode = mode ? IW_MODE_ADHOC : IW_MODE_INFRA;

	if (ioctl(drv->ioctl_sock, SIOCSIWMODE, &iwr) < 0) {
		perror("ioctl[SIOCSIWMODE]");
		ret = -1;
	}

	return ret;
}


static int wpa_driver_wext_pmksa(struct wpa_driver_wext_data *drv,
				 u32 cmd, const u8 *bssid, const u8 *pmkid)
{
	struct iwreq iwr;
	struct iw_pmksa pmksa;
	int ret = 0;

	memset(&iwr, 0, sizeof(iwr));
	strncpy(iwr.ifr_name, drv->ifname, IFNAMSIZ);
	memset(&pmksa, 0, sizeof(pmksa));
	pmksa.cmd = cmd;
	pmksa.bssid.sa_family = ARPHRD_ETHER;
	if (bssid)
		memcpy(pmksa.bssid.sa_data, bssid, ETH_ALEN);
	if (pmkid)
		memcpy(pmksa.pmkid, pmkid, IW_PMKID_LEN);
	iwr.u.data.pointer = (caddr_t) &pmksa;
	iwr.u.data.length = sizeof(pmksa);

	if (ioctl(drv->ioctl_sock, SIOCSIWPMKSA, &iwr) < 0) {
		if (errno != EOPNOTSUPP)
			perror("ioctl[SIOCSIWPMKSA]");
		ret = -1;
	}

	return ret;
}


static int wpa_driver_wext_add_pmkid(void *priv, const u8 *bssid,
				     const u8 *pmkid)
{
	struct wpa_driver_wext_data *drv = priv;
	return wpa_driver_wext_pmksa(drv, IW_PMKSA_ADD, bssid, pmkid);
}


static int wpa_driver_wext_remove_pmkid(void *priv, const u8 *bssid,
		 			const u8 *pmkid)
{
	struct wpa_driver_wext_data *drv = priv;
	return wpa_driver_wext_pmksa(drv, IW_PMKSA_REMOVE, bssid, pmkid);
}


static int wpa_driver_wext_flush_pmkid(void *priv)
{
	struct wpa_driver_wext_data *drv = priv;
	return wpa_driver_wext_pmksa(drv, IW_PMKSA_FLUSH, NULL, NULL);
}


static int wpa_driver_wext_get_capa(void *priv, struct wpa_driver_capa *capa)
{
	struct wpa_driver_wext_data *drv = priv;
	if (!drv->has_capability)
		return -1;
	memcpy(capa, &drv->capa, sizeof(*capa));
	return 0;
}


int wpa_driver_wext_alternative_ifindex(struct wpa_driver_wext_data *drv,
					const char *ifname)
{
	if (ifname == NULL) {
		drv->ifindex2 = -1;
		return 0;
	}

	drv->ifindex2 = if_nametoindex(ifname);
	if (drv->ifindex2 <= 0)
		return -1;

	wpa_printf(MSG_DEBUG, "Added alternative ifindex %d (%s) for "
		   "wireless events", drv->ifindex2, ifname);

	return 0;
}


const struct wpa_driver_ops wpa_driver_wext_ops = {
	.name = "wext",
	.desc = "Linux wireless extensions (generic)",
	.get_bssid = wpa_driver_wext_get_bssid,
	.get_ssid = wpa_driver_wext_get_ssid,
	.set_wpa = wpa_driver_wext_set_wpa,
	.set_key = wpa_driver_wext_set_key,
	.set_countermeasures = wpa_driver_wext_set_countermeasures,
	.set_drop_unencrypted = wpa_driver_wext_set_drop_unencrypted,
	.scan = wpa_driver_wext_scan,
	.get_scan_results = wpa_driver_wext_get_scan_results,
	.deauthenticate = wpa_driver_wext_deauthenticate,
	.disassociate = wpa_driver_wext_disassociate,
	.associate = wpa_driver_wext_associate,
	.set_auth_alg = wpa_driver_wext_set_auth_alg,
	.init = wpa_driver_wext_init,
	.deinit = wpa_driver_wext_deinit,
	.add_pmkid = wpa_driver_wext_add_pmkid,
	.remove_pmkid = wpa_driver_wext_remove_pmkid,
	.flush_pmkid = wpa_driver_wext_flush_pmkid,
	.get_capa = wpa_driver_wext_get_capa,
};