Commit f837a653 authored by Benjamin Berg's avatar Benjamin Berg Committed by Johannes Berg
Browse files

wifi: cfg80211: add element defragmentation helper 



This is already needed within mac80211 and support is also needed by
cfg80211 to parse ML elements.

Signed-off-by: default avatarBenjamin Berg <benjamin.berg@intel.com>
Signed-off-by: default avatarGregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230616094949.29c3ebeed10d.I009c049289dd0162c2e858ed8b68d2875a672ed6@changeid


Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 39432f8a

include/net/cfg80211.h

+22 −0
Original line number Diff line number Diff line
@@ -6676,6 +6676,28 @@ cfg80211_find_vendor_ie(unsigned int oui, int oui_type, 
	return (const void *)cfg80211_find_vendor_elem(oui, oui_type, ies, len);

}



/**

 * cfg80211_defragment_element - Defrag the given element data into a buffer

 *

 * @elem: the element to defragment

 * @ies: elements where @elem is contained

 * @ieslen: length of @ies

 * @data: buffer to store element data

 * @data_len: length of @data

 * @frag_id: the element ID of fragments

 *

 * Return: length of @data, or -EINVAL on error

 *

 * Copy out all data from an element that may be fragmented into @data, while

 * skipping all headers.

 *

 * The function uses memmove() internally. It is acceptable to defragment an

 * element in-place.

 */

ssize_t cfg80211_defragment_element(const struct element *elem, const u8 *ies,

				    size_t ieslen, u8 *data, size_t data_len,

				    u8 frag_id);



/**

 * cfg80211_send_layer2_update - send layer 2 update frame

 *

net/wireless/scan.c

+60 −0
Original line number Diff line number Diff line
@@ -2288,6 +2288,66 @@ static void cfg80211_parse_mbssid_data(struct wiphy *wiphy, 
	kfree(profile);

}



ssize_t cfg80211_defragment_element(const struct element *elem, const u8 *ies,

				    size_t ieslen, u8 *data, size_t data_len,

				    u8 frag_id)

{

	const struct element *next;

	ssize_t copied;

	u8 elem_datalen;



	if (!elem)

		return -EINVAL;



	/* elem might be invalid after the memmove */

	next = (void *)(elem->data + elem->datalen);



	elem_datalen = elem->datalen;

	if (elem->id == WLAN_EID_EXTENSION) {

		copied = elem->datalen - 1;

		if (copied > data_len)

			return -ENOSPC;



		memmove(data, elem->data + 1, copied);

	} else {

		copied = elem->datalen;

		if (copied > data_len)

			return -ENOSPC;



		memmove(data, elem->data, copied);

	}



	/* Fragmented elements must have 255 bytes */

	if (elem_datalen < 255)

		return copied;



	for (elem = next;

	     elem->data < ies + ieslen &&

		elem->data + elem->datalen < ies + ieslen;

	     elem = next) {

		/* elem might be invalid after the memmove */

		next = (void *)(elem->data + elem->datalen);



		if (elem->id != frag_id)

			break;



		elem_datalen = elem->datalen;



		if (copied + elem_datalen > data_len)

			return -ENOSPC;



		memmove(data + copied, elem->data, elem_datalen);

		copied += elem_datalen;



		/* Only the last fragment may be short */

		if (elem_datalen != 255)

			break;

	}



	return copied;

}

EXPORT_SYMBOL(cfg80211_defragment_element);



struct cfg80211_bss *

cfg80211_inform_bss_data(struct wiphy *wiphy,

			 struct cfg80211_inform_bss *data,