665d91b0e4
[ Upstream commit0600cf40e9] Add static inline dst_dev_overhead() function to include/net/dst.h. This helper function is used by ioam6_iptunnel, rpl_iptunnel and seg6_iptunnel to get the dev's overhead based on a cache entry (dst_entry). If the cache is empty, the default and generic value skb->mac_len is returned. Otherwise, LL_RESERVED_SPACE() over dst's dev is returned. Signed-off-by: Justin Iurman <justin.iurman@uliege.be> Cc: Alexander Lobakin <aleksander.lobakin@intel.com> Cc: Vadim Fedorenko <vadim.fedorenko@linux.dev> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Stable-dep-of:c64a0727f9("net: ipv6: fix dst ref loop on input in seg6 lwt") Signed-off-by: Sasha Levin <sashal@kernel.org>