| .. SPDX-License-Identifier: GPL-2.0 |
| |
| ================================ |
| TC Actions - Environmental Rules |
| ================================ |
| |
| |
| 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. |
| |
| 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. |
| |
| 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. |
