Re: [patch net-next v6 06/11] net: sched: use block index as a handle instead of qdisc when block is shared
From: Jiri Pirko <jiri@resnulli.us>
Date: 2018-01-06 20:43:15
Sat, Jan 06, 2018 at 12:09:24AM CET, jiri@resnulli.us wrote:
From: Jiri Pirko <redacted> As the tcm_ifindex 0 is invalid ifindex, reuse it to indicate that we work with block, instead of qdisc. So if tcm_ifindex is 0, tcm_parent is used to carry block_index. If the block is set to be shared between at least 2 qdiscs, it is forbidden to use the qdisc handle to add/delete filters. In that case, userspace has to pass block_index. Also, for dump of the filters, in case the block is shared in between at least 2 qdiscs, the each filter is dumped with tcm_ifindex 0 and tcm_parent set to block_index. That gives the user clear indication, that the filter belongs to a shared block and not only to one qdisc under which it is dumped. Suggested-by: David Ahern <redacted> Signed-off-by: Jiri Pirko <redacted> ---
[...]
quoted hunk ↗ jump to hunk
@@ -886,8 +887,13 @@ static int tcf_fill_node(struct net *net, struct sk_buff *skb,tcm->tcm_family = AF_UNSPEC; tcm->tcm__pad1 = 0; tcm->tcm__pad2 = 0; - tcm->tcm_ifindex = qdisc_dev(q)->ifindex; - tcm->tcm_parent = parent; + if (q) { + tcm->tcm_ifindex = qdisc_dev(q)->ifindex; + tcm->tcm_parent = parent; + } else { + tcm->tcm_ifindex = 0; /* block index is stored in parent */ + tcm->tcm_parent = block->index; + }
Please guys, please look at this reuse (also on clt side). I would like you to double-check this reuse of existing API for balock_index carrying purpose. I believe it's UAPI safe. But please, check it out carefully.