Commit e4d005b8 authored by Johannes Berg's avatar Johannes Berg
Browse files

mac80211: refactor extended element parsing 



This code was really ugly, refactor it a bit to make it more
readable.

While at it, use sizeof() and fix the UORA element length
check bug.

Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
Signed-off-by: default avatarLuca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/20200131111300.891737-4-luca@coelho.fi


Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 75e296e9

net/mac80211/util.c

+48 −27
Original line number Diff line number Diff line
@@ -890,6 +890,51 @@ void ieee80211_queue_delayed_work(struct ieee80211_hw *hw, 
}

EXPORT_SYMBOL(ieee80211_queue_delayed_work);



static void ieee80211_parse_extension_element(u32 *crc,

					      const struct element *elem,

					      struct ieee802_11_elems *elems)

{

	const void *data = elem->data + 1;

	u8 len = elem->datalen - 1;



	switch (elem->data[0]) {

	case WLAN_EID_EXT_HE_MU_EDCA:

		if (len == sizeof(*elems->mu_edca_param_set)) {

			elems->mu_edca_param_set = data;

			if (crc)

				*crc = crc32_be(*crc, (void *)elem,

						elem->datalen + 2);

		}

		break;

	case WLAN_EID_EXT_HE_CAPABILITY:

		elems->he_cap = data;

		elems->he_cap_len = len;

		break;

	case WLAN_EID_EXT_HE_OPERATION:

		if (len >= sizeof(*elems->he_operation) &&

		    len == ieee80211_he_oper_size(data) - 1)

			elems->he_operation = data;

		break;

	case WLAN_EID_EXT_UORA:

		if (len == 1)

			elems->uora_element = data;

		break;

	case WLAN_EID_EXT_MAX_CHANNEL_SWITCH_TIME:

		if (len == 3)

			elems->max_channel_switch_time = data;

		break;

	case WLAN_EID_EXT_MULTIPLE_BSSID_CONFIGURATION:

		if (len == sizeof(*elems->mbssid_config_ie))

			elems->mbssid_config_ie = data;

		break;

	case WLAN_EID_EXT_HE_SPR:

		if (len >= sizeof(*elems->he_spr) &&

		    len >= ieee80211_he_spr_size(data))

			elems->he_spr = data;

		break;

	}

}



static u32

_ieee802_11_parse_elems_crc(const u8 *start, size_t len, bool action,

			    struct ieee802_11_elems *elems,
@@ -1220,33 +1265,9 @@ _ieee802_11_parse_elems_crc(const u8 *start, size_t len, bool action, 
				elems->max_idle_period_ie = (void *)pos;

			break;

		case WLAN_EID_EXTENSION:

			if (pos[0] == WLAN_EID_EXT_HE_MU_EDCA &&

			    elen >= (sizeof(*elems->mu_edca_param_set) + 1)) {

				elems->mu_edca_param_set = (void *)&pos[1];

				if (calc_crc)

					crc = crc32_be(crc, pos - 2, elen + 2);

			} else if (pos[0] == WLAN_EID_EXT_HE_CAPABILITY) {

				elems->he_cap = (void *)&pos[1];

				elems->he_cap_len = elen - 1;

			} else if (pos[0] == WLAN_EID_EXT_HE_OPERATION &&

				   elen >= sizeof(*elems->he_operation) &&

				   elen >= ieee80211_he_oper_size(&pos[1])) {

				elems->he_operation = (void *)&pos[1];

			} else if (pos[0] == WLAN_EID_EXT_UORA && elen >= 1) {

				elems->uora_element = (void *)&pos[1];

			} else if (pos[0] ==

				   WLAN_EID_EXT_MAX_CHANNEL_SWITCH_TIME &&

				   elen == 4) {

				elems->max_channel_switch_time = pos + 1;

			} else if (pos[0] ==

				   WLAN_EID_EXT_MULTIPLE_BSSID_CONFIGURATION &&

				   elen == 3) {

				elems->mbssid_config_ie = (void *)&pos[1];

			} else if (pos[0] == WLAN_EID_EXT_HE_SPR &&

				   elen >= sizeof(*elems->he_spr) &&

				   elen >= ieee80211_he_spr_size(&pos[1])) {

				elems->he_spr = (void *)&pos[1];

			}

			ieee80211_parse_extension_element(calc_crc ?

								&crc : NULL,

							  elem, elems);

			break;

		default:

			break;