|The "environmental" rules for authors of any new tc actions are:
|1) If you stealeth or borroweth any packet thou shalt be branching
|from the righteous path and thou shalt cloneth.
|For example if your action queues a packet to be processed later,
|or intentionally branches by redirecting a packet, then you need to
|clone the packet.
|There are certain fields in the skb tc_verd that need to be reset so we
|avoid loops, etc. A few are generic enough that skb_act_clone()
|resets them for you, so invoke skb_act_clone() rather than skb_clone().
|2) If you munge any packet thou shalt call pskb_expand_head in the case
|someone else is referencing the skb. After that you "own" the skb.
|You must also tell us if it is ok to munge the packet (TC_OK2MUNGE),
|this way any action downstream can stomp on the packet.
|3) Dropping packets you don't own is a no-no. You simply return
|TC_ACT_SHOT to the caller and they will drop it.
|The "environmental" rules for callers of actions (qdiscs etc) are:
|*) Thou art responsible for freeing anything returned as being
|TC_ACT_SHOT/STOLEN/QUEUED. If none of TC_ACT_SHOT/STOLEN/QUEUED is
|returned, then all is great and you don't need to do anything.
|Post on netdev if something is unclear.