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| author | Alexander Aring <alex.aring@gmail.com> | 2015-09-02 14:21:26 +0200 |
|---|---|---|
| committer | Marcel Holtmann <marcel@holtmann.org> | 2015-09-17 13:20:03 +0200 |
| commit | faf7d36e5ecd16ab090c82d14bff31f7ab2f70e6 (patch) | |
| tree | 8599aabdec9d74a3815b247cf2a2d0eb58c45826 /net | |
| parent | ieee820154: 6lowpan: dispatch evaluation rework (diff) | |
| download | linux-faf7d36e5ecd16ab090c82d14bff31f7ab2f70e6.tar.xz linux-faf7d36e5ecd16ab090c82d14bff31f7ab2f70e6.zip | |
ieee802154: 6lowpan: add generic lowpan header check
This patch introduce an earlier check if a 6LoWPAN frame can be valid.
This contains at first for checking if the header contains a dispatch
byte and isn't the nalp dispatch value, which means it isn't a 6LoWPAN
packet. Also we add a check if we can derference the dispatch value by
checking if skb->len is unequal zero.
Reviewed-by: Stefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ieee802154/6lowpan/rx.c | 28 |
1 files changed, 27 insertions, 1 deletions
diff --git a/net/ieee802154/6lowpan/rx.c b/net/ieee802154/6lowpan/rx.c index fded1099fae0..c46cab3b0ff4 100644 --- a/net/ieee802154/6lowpan/rx.c +++ b/net/ieee802154/6lowpan/rx.c @@ -15,8 +15,11 @@ #include "6lowpan_i.h" +#define LOWPAN_DISPATCH_FIRST 0xc0 #define LOWPAN_DISPATCH_FRAG_MASK 0xf8 +#define LOWPAN_DISPATCH_NALP 0x00 + static int lowpan_give_skb_to_device(struct sk_buff *skb) { skb->protocol = htons(ETH_P_IPV6); @@ -162,13 +165,36 @@ rxh_next: #undef CALL_RXH } +static inline bool lowpan_is_nalp(u8 dispatch) +{ + return (dispatch & LOWPAN_DISPATCH_FIRST) == LOWPAN_DISPATCH_NALP; +} + +/* lowpan_rx_h_check checks on generic 6LoWPAN requirements + * in MAC and 6LoWPAN header. + * + * Don't manipulate the skb here, it could be shared buffer. + */ +static inline bool lowpan_rx_h_check(struct sk_buff *skb) +{ + /* check if we can dereference the dispatch */ + if (unlikely(!skb->len)) + return false; + + if (lowpan_is_nalp(*skb_network_header(skb))) + return false; + + return true; +} + static int lowpan_rcv(struct sk_buff *skb, struct net_device *wdev, struct packet_type *pt, struct net_device *orig_wdev) { struct net_device *ldev; if (wdev->type != ARPHRD_IEEE802154 || - skb->pkt_type == PACKET_OTHERHOST) + skb->pkt_type == PACKET_OTHERHOST || + !lowpan_rx_h_check(skb)) return NET_RX_DROP; ldev = wdev->ieee802154_ptr->lowpan_dev; |