tc-actions-env-rules.rst (1053B)
1.. SPDX-License-Identifier: GPL-2.0 2 3================================ 4TC Actions - Environmental Rules 5================================ 6 7 8The "environmental" rules for authors of any new tc actions are: 9 101) If you stealeth or borroweth any packet thou shalt be branching 11 from the righteous path and thou shalt cloneth. 12 13 For example if your action queues a packet to be processed later, 14 or intentionally branches by redirecting a packet, then you need to 15 clone the packet. 16 172) If you munge any packet thou shalt call pskb_expand_head in the case 18 someone else is referencing the skb. After that you "own" the skb. 19 203) Dropping packets you don't own is a no-no. You simply return 21 TC_ACT_SHOT to the caller and they will drop it. 22 23The "environmental" rules for callers of actions (qdiscs etc) are: 24 25#) Thou art responsible for freeing anything returned as being 26 TC_ACT_SHOT/STOLEN/QUEUED. If none of TC_ACT_SHOT/STOLEN/QUEUED is 27 returned, then all is great and you don't need to do anything. 28 29Post on netdev if something is unclear.