Commit 6b756efc authored by Johannes Berg's avatar Johannes Berg
Browse files

wifi: cfg80211: refactor RNR parsing 



We'll need more parsing of the reduced neighbor report element,
and we already have two places doing pretty much the same.
Combine by refactoring the parsing into a separate function
with a callback for each item found.

Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
Reviewed-by: default avatarBenjamin Berg <benjamin.berg@intel.com>
Signed-off-by: default avatarMiri Korenblit <miriam.rachel.korenblit@intel.com>
Link: https://msgid.link/20240216135047.cfff14b692fc.Ibe25be88a769eab29ebb17b9d19af666df6a2227@changeid


Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 7e899c1d

net/wireless/scan.c

+169 −137
Original line number Diff line number Diff line
@@ -611,104 +611,144 @@ static int cfg80211_parse_ap_info(struct cfg80211_colocated_ap *entry, 
	return 0;

}



VISIBLE_IF_CFG80211_KUNIT int

cfg80211_parse_colocated_ap(const struct cfg80211_bss_ies *ies,

			    struct list_head *list)

enum cfg80211_rnr_iter_ret {

	RNR_ITER_CONTINUE,

	RNR_ITER_BREAK,

	RNR_ITER_ERROR,

};



static bool

cfg80211_iter_rnr(const u8 *elems, size_t elems_len,

		  enum cfg80211_rnr_iter_ret

		  (*iter)(void *data, u8 type,

			  const struct ieee80211_neighbor_ap_info *info,

			  const u8 *tbtt_info, u8 tbtt_info_len),

		  void *iter_data)

{

	struct ieee80211_neighbor_ap_info *ap_info;

	const struct element *elem, *ssid_elem;

	const struct element *rnr;

	const u8 *pos, *end;

	u32 s_ssid_tmp;

	int n_coloc = 0, ret;

	LIST_HEAD(ap_list);



	ret = cfg80211_calc_short_ssid(ies, &ssid_elem, &s_ssid_tmp);

	if (ret)

		return 0;

	for_each_element_id(rnr, WLAN_EID_REDUCED_NEIGHBOR_REPORT,

			    elems, elems_len) {

		const struct ieee80211_neighbor_ap_info *info;



	for_each_element_id(elem, WLAN_EID_REDUCED_NEIGHBOR_REPORT,

			    ies->data, ies->len) {

		pos = elem->data;

		end = elem->data + elem->datalen;

		pos = rnr->data;

		end = rnr->data + rnr->datalen;



		/* RNR IE may contain more than one NEIGHBOR_AP_INFO */

		while (pos + sizeof(*ap_info) <= end) {

			enum nl80211_band band;

			int freq;

		while (sizeof(*info) <= end - pos) {

			u8 length, i, count;

			u8 type;



			ap_info = (void *)pos;

			count = u8_get_bits(ap_info->tbtt_info_hdr,

					    IEEE80211_AP_INFO_TBTT_HDR_COUNT) + 1;

			length = ap_info->tbtt_info_len;

			info = (void *)pos;

			count = u8_get_bits(info->tbtt_info_hdr,

					    IEEE80211_AP_INFO_TBTT_HDR_COUNT) +

				1;

			length = info->tbtt_info_len;



			pos += sizeof(*ap_info);

			pos += sizeof(*info);



			if (!ieee80211_operating_class_to_band(ap_info->op_class,

							       &band))

				break;

			if (count * length > end - pos)

				return false;



			freq = ieee80211_channel_to_frequency(ap_info->channel,

							      band);

			type = u8_get_bits(info->tbtt_info_hdr,

					   IEEE80211_AP_INFO_TBTT_HDR_TYPE);



			if (end - pos < count * length)

			for (i = 0; i < count; i++) {

				switch (iter(iter_data, type, info,

					     pos, length)) {

				case RNR_ITER_CONTINUE:

					break;

				case RNR_ITER_BREAK:

					return true;

				case RNR_ITER_ERROR:

					return false;

				}



			if (u8_get_bits(ap_info->tbtt_info_hdr,

					IEEE80211_AP_INFO_TBTT_HDR_TYPE) !=

			    IEEE80211_TBTT_INFO_TYPE_TBTT) {

				pos += count * length;

				continue;

				pos += length;

			}

		}



			/* TBTT info must include bss param + BSSID +

			 * (short SSID or same_ssid bit to be set).

			 * ignore other options, and move to the

			 * next AP info

			 */

			if (band != NL80211_BAND_6GHZ ||

			    !(length == offsetofend(struct ieee80211_tbtt_info_7_8_9,

						    bss_params) ||

			      length == sizeof(struct ieee80211_tbtt_info_7_8_9) ||

			      length >= offsetofend(struct ieee80211_tbtt_info_ge_11,

						    bss_params))) {

				pos += count * length;

				continue;

		if (pos != end)

			return false;

	}



			for (i = 0; i < count; i++) {

	return true;

}



struct colocated_ap_data {

	const struct element *ssid_elem;

	struct list_head ap_list;

	u32 s_ssid_tmp;

	int n_coloc;

};



static enum cfg80211_rnr_iter_ret

cfg80211_parse_colocated_ap_iter(void *_data, u8 type,

				 const struct ieee80211_neighbor_ap_info *info,

				 const u8 *tbtt_info, u8 tbtt_info_len)

{

	struct colocated_ap_data *data = _data;

	struct cfg80211_colocated_ap *entry;

	enum nl80211_band band;



				entry = kzalloc(sizeof(*entry) + IEEE80211_MAX_SSID_LEN,

						GFP_ATOMIC);

	if (type != IEEE80211_TBTT_INFO_TYPE_TBTT)

		return RNR_ITER_CONTINUE;



	if (!ieee80211_operating_class_to_band(info->op_class, &band))

		return RNR_ITER_CONTINUE;



	/* TBTT info must include bss param + BSSID + (short SSID or

	 * same_ssid bit to be set). Ignore other options, and move to

	 * the next AP info

	 */

	if (band != NL80211_BAND_6GHZ ||

	    !(tbtt_info_len == offsetofend(struct ieee80211_tbtt_info_7_8_9,

					   bss_params) ||

	      tbtt_info_len == sizeof(struct ieee80211_tbtt_info_7_8_9) ||

	      tbtt_info_len >= offsetofend(struct ieee80211_tbtt_info_ge_11,

					   bss_params)))

		return RNR_ITER_CONTINUE;



	entry = kzalloc(sizeof(*entry) + IEEE80211_MAX_SSID_LEN, GFP_ATOMIC);

	if (!entry)

					goto error;

		return RNR_ITER_ERROR;



				entry->center_freq = freq;

	entry->center_freq =

		ieee80211_channel_to_frequency(info->channel, band);



				if (!cfg80211_parse_ap_info(entry, pos, length,

							    ssid_elem,

							    s_ssid_tmp)) {

					n_coloc++;

					list_add_tail(&entry->list, &ap_list);

	if (!cfg80211_parse_ap_info(entry, tbtt_info, tbtt_info_len,

				    data->ssid_elem, data->s_ssid_tmp)) {

		data->n_coloc++;

		list_add_tail(&entry->list, &data->ap_list);

	} else {

		kfree(entry);

	}



				pos += length;

			}

	return RNR_ITER_CONTINUE;

}



error:

		if (pos != end) {

			cfg80211_free_coloc_ap_list(&ap_list);

VISIBLE_IF_CFG80211_KUNIT int

cfg80211_parse_colocated_ap(const struct cfg80211_bss_ies *ies,

			    struct list_head *list)

{

	struct colocated_ap_data data = {};

	int ret;



	INIT_LIST_HEAD(&data.ap_list);



	ret = cfg80211_calc_short_ssid(ies, &data.ssid_elem, &data.s_ssid_tmp);

	if (ret)

		return 0;



	if (!cfg80211_iter_rnr(ies->data, ies->len,

			       cfg80211_parse_colocated_ap_iter, &data)) {

		cfg80211_free_coloc_ap_list(&data.ap_list);

		return 0;

		}

	}



	list_splice_tail(&ap_list, list);

	return n_coloc;

	list_splice_tail(&data.ap_list, list);

	return data.n_coloc;

}

EXPORT_SYMBOL_IF_CFG80211_KUNIT(cfg80211_parse_colocated_ap);
@@ -2607,79 +2647,71 @@ cfg80211_defrag_mle(const struct element *mle, const u8 *ie, size_t ielen, 
	return NULL;

}



static u8

cfg80211_rnr_info_for_mld_ap(const u8 *ie, size_t ielen, u8 mld_id, u8 link_id,

			     const struct ieee80211_neighbor_ap_info **ap_info,

			     u8 *param_ch_count)

{

	const struct ieee80211_neighbor_ap_info *info;

	const struct element *rnr;

	const u8 *pos, *end;



	for_each_element_id(rnr, WLAN_EID_REDUCED_NEIGHBOR_REPORT, ie, ielen) {

		pos = rnr->data;

		end = rnr->data + rnr->datalen;



		/* RNR IE may contain more than one NEIGHBOR_AP_INFO */

		while (sizeof(*info) <= end - pos) {

			const struct ieee80211_rnr_mld_params *mld_params;

			u16 params;

			u8 length, i, count, mld_params_offset;

			u8 type, lid;

struct tbtt_info_iter_data {

	const struct ieee80211_neighbor_ap_info *ap_info;

	u8 param_ch_count;

	u32 use_for;

	u8 mld_id, link_id;

};



			info = (void *)pos;

			count = u8_get_bits(info->tbtt_info_hdr,

					    IEEE80211_AP_INFO_TBTT_HDR_COUNT) + 1;

			length = info->tbtt_info_len;



			pos += sizeof(*info);



			if (count * length > end - pos)

				return 0;



			type = u8_get_bits(info->tbtt_info_hdr,

					   IEEE80211_AP_INFO_TBTT_HDR_TYPE);

static enum cfg80211_rnr_iter_ret

cfg802121_mld_ap_rnr_iter(void *_data, u8 type,

			  const struct ieee80211_neighbor_ap_info *info,

			  const u8 *tbtt_info, u8 tbtt_info_len)

{

	const struct ieee80211_rnr_mld_params *mld_params;

	struct tbtt_info_iter_data *data = _data;

	u8 link_id;



	if (type == IEEE80211_TBTT_INFO_TYPE_TBTT &&

			    length >=

			    offsetofend(struct ieee80211_tbtt_info_ge_11,

					mld_params)) {

				mld_params_offset =

					offsetof(struct ieee80211_tbtt_info_ge_11, mld_params);

				use_for = NL80211_BSS_USE_FOR_ALL;

			} else if (type == IEEE80211_TBTT_INFO_TYPE_MLD &&

				   length >= sizeof(struct ieee80211_rnr_mld_params)) {

				mld_params_offset = 0;

				use_for = NL80211_BSS_USE_FOR_MLD_LINK;

			} else {

				pos += count * length;

				continue;

			}



			for (i = 0; i < count; i++) {

				mld_params = (void *)pos + mld_params_offset;

				params = le16_to_cpu(mld_params->params);

	    tbtt_info_len >= offsetofend(struct ieee80211_tbtt_info_ge_11,

					 mld_params))

		mld_params = (void *)(tbtt_info +

				      offsetof(struct ieee80211_tbtt_info_ge_11,

					       mld_params));

	else if (type == IEEE80211_TBTT_INFO_TYPE_MLD &&

		 tbtt_info_len >= sizeof(struct ieee80211_rnr_mld_params))

		mld_params = (void *)tbtt_info;

	else

		return RNR_ITER_CONTINUE;



				lid = u16_get_bits(params,

	link_id = le16_get_bits(mld_params->params,

				IEEE80211_RNR_MLD_PARAMS_LINK_ID);



				if (mld_id == mld_params->mld_id &&

				    link_id == lid) {

					*ap_info = info;

					*param_ch_count =

	if (data->mld_id != mld_params->mld_id)

		return RNR_ITER_CONTINUE;



	if (data->link_id != link_id)

		return RNR_ITER_CONTINUE;



	data->ap_info = info;

	data->param_ch_count =

		le16_get_bits(mld_params->params,

			      IEEE80211_RNR_MLD_PARAMS_BSS_CHANGE_COUNT);



					return use_for;

	if (type == IEEE80211_TBTT_INFO_TYPE_TBTT)

		data->use_for = NL80211_BSS_USE_FOR_ALL;

	else

		data->use_for = NL80211_BSS_USE_FOR_MLD_LINK;

	return RNR_ITER_BREAK;

}



				pos += length;

			}

		}

	}

static u8

cfg80211_rnr_info_for_mld_ap(const u8 *ie, size_t ielen, u8 mld_id, u8 link_id,

			     const struct ieee80211_neighbor_ap_info **ap_info,

			     u8 *param_ch_count)

{

	struct tbtt_info_iter_data data = {

		.mld_id = mld_id,

		.link_id = link_id,

	};



	return 0;

	cfg80211_iter_rnr(ie, ielen, cfg802121_mld_ap_rnr_iter, &data);



	*ap_info = data.ap_info;

	*param_ch_count = data.param_ch_count;



	return data.use_for;

}



static struct element *