| 1234567891011121314151617181920212223242526272829 |
- The "enviromental" 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 intentionaly 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 so much so 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 dont own is a nono. You simply return
- TC_ACT_SHOT to the caller and they will drop it.
- The "enviromental" 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 dont need to do anything.
- Post on netdev if something is unclear.
|
