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Commit 54552d03 authored by Alexander Aring's avatar Alexander Aring Committed by Marcel Holtmann
Browse files

ieee802154: 6lowpan: check on valid 802.15.4 frame 



This patch adds frame control checks to check if the received frame is
something which could contain a 6LoWPAN packet.

Reviewed-by: default avatarStefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: default avatarAlexander Aring <alex.aring@gmail.com>
Signed-off-by: default avatarMarcel Holtmann <marcel@holtmann.org>
parent c6fdbba3

include/linux/ieee802154.h

+25 −0
Original line number Diff line number Diff line
@@ -205,6 +205,31 @@ enum { 
	IEEE802154_SCAN_IN_PROGRESS = 0xfc,

};



/* frame control handling */

#define IEEE802154_FCTL_FTYPE		0x0003

#define IEEE802154_FCTL_INTRA_PAN	0x0040



#define IEEE802154_FTYPE_DATA		0x0001



/*

 * ieee802154_is_data - check if type is IEEE802154_FTYPE_DATA

 * @fc: frame control bytes in little-endian byteorder

 */

static inline int ieee802154_is_data(__le16 fc)

{

	return (fc & cpu_to_le16(IEEE802154_FCTL_FTYPE)) ==

		cpu_to_le16(IEEE802154_FTYPE_DATA);

}



/**

 * ieee802154_is_intra_pan - check if intra pan id communication

 * @fc: frame control bytes in little-endian byteorder

 */

static inline bool ieee802154_is_intra_pan(__le16 fc)

{

	return fc & cpu_to_le16(IEEE802154_FCTL_INTRA_PAN);

}



/**

 * ieee802154_is_valid_psdu_len - check if psdu len is valid

 * available lengths:

include/net/mac802154.h

+15 −0
Original line number Diff line number Diff line
@@ -249,6 +249,21 @@ struct ieee802154_ops { 
						const bool on);

};



/**

 * ieee802154_get_fc_from_skb - get the frame control field from an skb

 * @skb: skb where the frame control field will be get from

 */

static inline __le16 ieee802154_get_fc_from_skb(const struct sk_buff *skb)

{

	/* return some invalid fc on failure */

	if (unlikely(skb->mac_len < 2)) {

		WARN_ON(1);

		return cpu_to_le16(0);

	}



	return (__force __le16)__get_unaligned_memmove16(skb_mac_header(skb));

}



/**

 * ieee802154_be64_to_le64 - copies and convert be64 to le64

 * @le64_dst: le64 destination pointer

net/ieee802154/6lowpan/rx.c

+8 −0
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
#include <linux/if_arp.h>



#include <net/6lowpan.h>

#include <net/mac802154.h>

#include <net/ieee802154_netdev.h>



#include "6lowpan_i.h"
@@ -280,6 +281,13 @@ static inline bool lowpan_is_reserved(u8 dispatch) 
 */

static inline bool lowpan_rx_h_check(struct sk_buff *skb)

{

	__le16 fc = ieee802154_get_fc_from_skb(skb);



	/* check on ieee802154 conform 6LoWPAN header */

	if (!ieee802154_is_data(fc) ||

	    !ieee802154_is_intra_pan(fc))

		return false;



	/* check if we can dereference the dispatch */

	if (unlikely(!skb->len))

		return false;