| rjw | 1f88458 | 2022-01-06 17:20:42 +0800 | [diff] [blame^] | 1 | |
| 2 | The "environmental" rules for authors of any new tc actions are: |
| 3 | |
| 4 | 1) If you stealeth or borroweth any packet thou shalt be branching |
| 5 | from the righteous path and thou shalt cloneth. |
| 6 | |
| 7 | For example if your action queues a packet to be processed later, |
| 8 | or intentionally branches by redirecting a packet, then you need to |
| 9 | clone the packet. |
| 10 | |
| 11 | 2) If you munge any packet thou shalt call pskb_expand_head in the case |
| 12 | someone else is referencing the skb. After that you "own" the skb. |
| 13 | |
| 14 | 3) Dropping packets you don't own is a no-no. You simply return |
| 15 | TC_ACT_SHOT to the caller and they will drop it. |
| 16 | |
| 17 | The "environmental" rules for callers of actions (qdiscs etc) are: |
| 18 | |
| 19 | *) Thou art responsible for freeing anything returned as being |
| 20 | TC_ACT_SHOT/STOLEN/QUEUED. If none of TC_ACT_SHOT/STOLEN/QUEUED is |
| 21 | returned, then all is great and you don't need to do anything. |
| 22 | |
| 23 | Post on netdev if something is unclear. |
| 24 | |