Hello. On 31/08/15 00:03, Stefan Schmidt wrote:
Hello. On 20/08/15 18:47, Alexander Aring wrote:This patch adds frame control checks to check if the received frame is something which could contain a 6LoWPAN packet. Signed-off-by: Alexander Aring <alex.aring@xxxxxxxxx> --- include/linux/ieee802154.h | 25 +++++++++++++++++++++++++ include/net/mac802154.h | 15 +++++++++++++++ net/ieee802154/6lowpan/rx.c | 8 ++++++++ 3 files changed, 48 insertions(+) diff --git a/include/linux/ieee802154.h b/include/linux/ieee802154.h index 1dc1f4e..db01492 100644 --- a/include/linux/ieee802154.h +++ b/include/linux/ieee802154.h @@ -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: diff --git a/include/net/mac802154.h b/include/net/mac802154.h index b7f9961..32bd7c0 100644 --- a/include/net/mac802154.h +++ b/include/net/mac802154.h @@ -250,6 +250,21 @@ struct ieee802154_ops { }; /** + * 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 * @be64_src: be64 source pointer diff --git a/net/ieee802154/6lowpan/rx.c b/net/ieee802154/6lowpan/rx.c index f98ebf5..5be996a 100644 --- a/net/ieee802154/6lowpan/rx.c +++ b/net/ieee802154/6lowpan/rx.c @@ -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" @@ -278,6 +279,13 @@ 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;Signed-off-by: Stefan Schmidt <stefan@xxxxxxxxxxxxxxx>
This should also have been Reviewed-by: Stefan Schmidt <stefan@xxxxxxxxxxxxxxx> regards Stefan Schmidt -- To unsubscribe from this list: send the line "unsubscribe linux-wpan" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
