From: Cong Wang xiyou.wangcong@gmail.com
[ Upstream commit a7df4870d79b00742da6cc93ca2f336a71db77f7 ]
When we tell kernel to dump filters from root (ffff:ffff), those filters on ingress (ffff:0000) are matched, but their true parents must be dumped as they are. However, kernel dumps just whatever we tell it, that is either ffff:ffff or ffff:0000:
$ nl-cls-list --dev=dummy0 --parent=root cls basic dev dummy0 id none parent root prio 49152 protocol ip match-all cls basic dev dummy0 id :1 parent root prio 49152 protocol ip match-all $ nl-cls-list --dev=dummy0 --parent=ffff: cls basic dev dummy0 id none parent ffff: prio 49152 protocol ip match-all cls basic dev dummy0 id :1 parent ffff: prio 49152 protocol ip match-all
This is confusing and misleading, more importantly this is a regression since 4.15, so the old behavior must be restored.
And, when tc filters are installed on a tc class, the parent should be the classid, rather than the qdisc handle. Commit edf6711c9840 ("net: sched: remove classid and q fields from tcf_proto") removed the classid we save for filters, we can just restore this classid in tcf_block.
Steps to reproduce this: ip li set dev dummy0 up tc qd add dev dummy0 ingress tc filter add dev dummy0 parent ffff: protocol arp basic action pass tc filter show dev dummy0 root
Before this patch: filter protocol arp pref 49152 basic filter protocol arp pref 49152 basic handle 0x1 action order 1: gact action pass random type none pass val 0 index 1 ref 1 bind 1
After this patch: filter parent ffff: protocol arp pref 49152 basic filter parent ffff: protocol arp pref 49152 basic handle 0x1 action order 1: gact action pass random type none pass val 0 index 1 ref 1 bind 1
Fixes: a10fa20101ae ("net: sched: propagate q and parent from caller down to tcf_fill_node") Fixes: edf6711c9840 ("net: sched: remove classid and q fields from tcf_proto") Cc: Jamal Hadi Salim jhs@mojatatu.com Cc: Jiri Pirko jiri@resnulli.us Signed-off-by: Cong Wang xiyou.wangcong@gmail.com Acked-by: Jamal Hadi Salim jhs@mojatatu.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- include/net/sch_generic.h | 1 + net/sched/cls_api.c | 8 ++++---- 2 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index 9fb7cf1cdf36c..3d03756e10699 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -407,6 +407,7 @@ struct tcf_block { struct mutex lock; struct list_head chain_list; u32 index; /* block index for shared blocks */ + u32 classid; /* which class this block belongs to */ refcount_t refcnt; struct net *net; struct Qdisc *q; diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c index c2cdd0fc2e709..68c8fc6f535c7 100644 --- a/net/sched/cls_api.c +++ b/net/sched/cls_api.c @@ -2005,6 +2005,7 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n, err = PTR_ERR(block); goto errout; } + block->classid = parent;
chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0; if (chain_index > TC_ACT_EXT_VAL_MASK) { @@ -2547,12 +2548,10 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb) return skb->len;
parent = tcm->tcm_parent; - if (!parent) { + if (!parent) q = dev->qdisc; - parent = q->handle; - } else { + else q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent)); - } if (!q) goto out; cops = q->ops->cl_ops; @@ -2568,6 +2567,7 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb) block = cops->tcf_block(q, cl, NULL); if (!block) goto out; + parent = block->classid; if (tcf_block_shared(block)) q = NULL; }