net: sched: use counter to break reclassify loops
Seems all we want here is to avoid endless 'goto reclassify' loop.
tc_classify_compat even resets this counter when something other
than TC_ACT_RECLASSIFY is returned, so this skb-counter doesn't
break hypothetical loops induced by something other than perpetual
TC_ACT_RECLASSIFY return values.
skb_act_clone is now identical to skb_clone, so just use that.
Tested with following (bogus) filter:
tc filter add dev eth0 parent ffff: \
protocol ip u32 match u32 0 0 police rate 10Kbit burst \
64000 mtu 1500 action reclassify
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c
index 3f63cea..a42a3b2 100644
--- a/net/sched/act_mirred.c
+++ b/net/sched/act_mirred.c
@@ -151,7 +151,7 @@
}
at = G_TC_AT(skb->tc_verd);
- skb2 = skb_act_clone(skb, GFP_ATOMIC, m->tcf_action);
+ skb2 = skb_clone(skb, GFP_ATOMIC);
if (skb2 == NULL)
goto out;
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index ad9eed7..0b74dc0 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -1816,13 +1816,8 @@
continue;
err = tp->classify(skb, tp, res);
- if (err >= 0) {
-#ifdef CONFIG_NET_CLS_ACT
- if (err != TC_ACT_RECLASSIFY && skb->tc_verd)
- skb->tc_verd = SET_TC_VERD(skb->tc_verd, 0);
-#endif
+ if (err >= 0)
return err;
- }
}
return -1;
}
@@ -1834,23 +1829,22 @@
int err = 0;
#ifdef CONFIG_NET_CLS_ACT
const struct tcf_proto *otp = tp;
+ int limit = 0;
reclassify:
#endif
err = tc_classify_compat(skb, tp, res);
#ifdef CONFIG_NET_CLS_ACT
if (err == TC_ACT_RECLASSIFY) {
- u32 verd = G_TC_VERD(skb->tc_verd);
tp = otp;
- if (verd++ >= MAX_REC_LOOP) {
+ if (unlikely(limit++ >= MAX_REC_LOOP)) {
net_notice_ratelimited("%s: packet reclassify loop rule prio %u protocol %02x\n",
tp->q->ops->id,
tp->prio & 0xffff,
ntohs(tp->protocol));
return TC_ACT_SHOT;
}
- skb->tc_verd = SET_TC_VERD(skb->tc_verd, verd);
goto reclassify;
}
#endif