[PATCH 5.4 037/110] net_sched: walk through all child classes in tc_bind_tclass()

Greg Kroah-Hartman
2020-01-30T18:43:28Z

From: Cong Wang <xiyou.wangcong@gmail.com>

[ Upstream commit 760d228e322e99cdf6d81b4b60a268b8f13cf67a ]

In a complex TC class hierarchy like this:

tc qdisc add dev eth0 root handle 1:0 cbq bandwidth 100Mbit \
avpkt 1000 cell 8
tc class add dev eth0 parent 1:0 classid 1:1 cbq bandwidth 100Mbit \
rate 6Mbit weight 0.6Mbit prio 8 allot 1514 cell 8 maxburst 20 \
avpkt 1000 bounded

tc filter add dev eth0 parent 1:0 protocol ip prio 1 u32 match ip \
sport 80 0xffff flowid 1:3
tc filter add dev eth0 parent 1:0 protocol ip prio 1 u32 match ip \
sport 25 0xffff flowid 1:4

tc class add dev eth0 parent 1:1 classid 1:3 cbq bandwidth 100Mbit \
rate 5Mbit weight 0.5Mbit prio 5 allot 1514 cell 8 maxburst 20 \
avpkt 1000
tc class add dev eth0 parent 1:1 classid 1:4 cbq bandwidth 100Mbit \
rate 3Mbit weight 0.3Mbit prio 5 allot 1514 cell 8 maxburst 20 \
avpkt 1000

where filters are installed on qdisc 1:0, so we can't merely
search from class 1:1 when creating class 1:3 and class 1:4. We have
to walk through all the child classes of the direct parent qdisc.
Otherwise we would miss filters those need reverse binding.

Fixes: 07d79fc7d94e ("net_sched: add reverse binding for tc class")
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/sched/sch_api.c | 41 ++++++++++++++++++++++++++++++-----------
1 file changed, 30 insertions(+), 11 deletions(-)

--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -1910,22 +1910,24 @@ static int tcf_node_bind(struct tcf_prot
return 0;
}

-static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid,
- unsigned long new_cl)
+struct tc_bind_class_args {
+ struct qdisc_walker w;
+ unsigned long new_cl;
+ u32 portid;
+ u32 clid;
+};
+
+static int tc_bind_class_walker(struct Qdisc *q, unsigned long cl,
+ struct qdisc_walker *w)
{
+ struct tc_bind_class_args *a = (struct tc_bind_class_args *)w;
const struct Qdisc_class_ops *cops = q->ops->cl_ops;
struct tcf_block *block;
struct tcf_chain *chain;
- unsigned long cl;

- cl = cops->find(q, portid);
- if (!cl)
- return;
- if (!cops->tcf_block)
- return;
block = cops->tcf_block(q, cl, NULL);
if (!block)
- return;
+ return 0;
for (chain = tcf_get_next_chain(block, NULL);
chain;
chain = tcf_get_next_chain(block, chain)) {
@@ -1936,12 +1938,29 @@ static void tc_bind_tclass(struct Qdisc
struct tcf_bind_args arg = {};

arg.w.fn = tcf_node_bind;
- arg.classid = clid;
+ arg.classid = a->clid;
arg.base = cl;
- arg.cl = new_cl;
+ arg.cl = a->new_cl;
tp->ops->walk(tp, &arg.w, true);
}
}
+
+ return 0;
+}
+
+static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid,
+ unsigned long new_cl)
+{
+ const struct Qdisc_class_ops *cops = q->ops->cl_ops;
+ struct tc_bind_class_args args = {};
+
+ if (!cops->tcf_block)
+ return;
+ args.portid = portid;
+ args.clid = clid;
+ args.new_cl = new_cl;
+ args.w.fn = tc_bind_class_walker;
+ q->ops->cl_ops->walk(q, &args.w);
}

#else