GitLab

We currently have two code paths for broadcast packets:

A) self-generated, via batadv_interface_tx()->
   batadv_send_bcast_packet().
B) received/forwarded, via batadv_recv_bcast_packet()->
   batadv_forw_bcast_packet().

For A), self-generated broadcast packets:

The only modifications to the skb data is the ethernet header which is
added/pushed to the skb in
batadv_send_broadcast_skb()->batadv_send_skb_packet(). However before
doing so, batadv_skb_head_push() is called which calls skb_cow_head() to
unshare the space for the to be pushed ethernet header. So for this
case, it is safe to use skb clones.

For B), received/forwarded packets:

The same applies as in A) for the to be forwarded packets. Only the
ethernet header is added. However after (queueing for) forwarding the
packet in batadv_recv_bcast_packet()->batadv_forw_bcast_packet(), a
packet is additionally decapsulated and is sent up the stack through
batadv_recv_bcast_packet()->batadv_interface_...