The "dev_has_header" function, recently added in commit d549699048b4 ("net/packet: fix packet receive on L3 devices without visible hard header"), is more accurate as criteria for determining whether a device exposes the LL header to upper layers, because in addition to dev->header_ops, it also checks for dev->header_ops->create.
When transmitting an skb on a device, dev_hard_header can be called to generate an LL header. dev_hard_header will only generate a header if dev->header_ops->create is present. Signed-off-by: Xie He <xie.he.0...@gmail.com> --- net/packet/af_packet.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 6bbc7a448593..e24b2841c643 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -132,17 +132,17 @@ Resume because it is invisible to us. On transmit: ------------ -dev->header_ops != NULL +dev_has_header(dev) == true mac_header -> ll header data -> ll header -dev->header_ops == NULL (ll header is invisible to us) +dev_has_header(dev) == false (ll header is invisible to us) mac_header -> data data -> data We should set network_header on output to the correct position, packet classifier depends on it. */ -- 2.27.0