net: flow_dissector: add __skb_get_poff to get a start offset to payload
__skb_get_poff() returns the offset to the payload as far as it could
be dissected. The main user is currently BPF, so that we can dynamically
truncate packets without needing to push actual payload to the user
space and instead can analyze headers only.
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index b66ecc6..4974121 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -2840,6 +2840,8 @@
bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off);
+u32 __skb_get_poff(const struct sk_buff *skb);
+
/**
* skb_head_is_locked - Determine if the skb->head is locked down
* @skb: skb to check