From 4666669fc3b83f0d01b08c6b17432563f2eedcba Mon Sep 17 00:00:00 2001 From: Alexander Aring Date: Fri, 16 Aug 2013 21:59:56 +0200 Subject: [PATCH] 6lowpan: introduce lowpan_fetch_skb function This patch adds a helper function to parse the ipv6 header to a 6lowpan header in stream. This function checks first if we can pull data with a specific length from a skb. If this seems to be okay, we copy skb data to a destination pointer and run skb_pull. Signed-off-by: Alexander Aring Reviewed-by: Werner Almesberger Signed-off-by: David S. Miller --- net/ieee802154/6lowpan.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/net/ieee802154/6lowpan.h b/net/ieee802154/6lowpan.h index 4b8f917658b5..a636545d8dcf 100644 --- a/net/ieee802154/6lowpan.h +++ b/net/ieee802154/6lowpan.h @@ -230,4 +230,16 @@ dest = 16 bit inline */ #define LOWPAN_NHC_UDP_CS_P_11 0xF3 /* source & dest = 0xF0B + 4bit inline */ +static inline bool lowpan_fetch_skb(struct sk_buff *skb, + void *data, const unsigned int len) +{ + if (unlikely(!pskb_may_pull(skb, len))) + return true; + + skb_copy_from_linear_data(skb, data, len); + skb_pull(skb, len); + + return false; +} + #endif /* __6LOWPAN_H__ */