net/packet: Improve the comment about LL header visibility criteria

The "dev_has_header" function, recently added in commit d549699 ("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 <[email protected]> Acked-by: Willem de Bruijn <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jakub Kicinski <[email protected]>
ashr · Feb 6, 2021 · 21c8597 · 21c8597
1 parent 163a180
commit 21c8597
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
@@ -135,11 +135,11 @@ Resume
 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