[NET_SCHED]: act_api: qdisc internal reclassify support
The behaviour of NET_CLS_POLICE for TC_POLICE_RECLASSIFY was to return
it to the qdisc, which could handle it internally or ignore it. With
NET_CLS_ACT however, tc_classify starts over at the first classifier
and never returns it to the qdisc. This makes it impossible to support
qdisc-internal reclassification, which in turn makes it impossible to
remove the old NET_CLS_POLICE code without breaking compatibility since
we have two qdiscs (CBQ and ATM) that support this.
This patch adds a tc_classify_compat function that handles
reclassification the old way and changes CBQ and ATM to use it.
This again is of course not fully backwards compatible with the previous
NET_CLS_ACT behaviour. Unfortunately there is no way to fully maintain
compatibility *and* support qdisc internal reclassification with
NET_CLS_ACT, but this seems like the better choice over keeping the two
incompatible options around forever.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 4fd0bec..13c09bc 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -1145,47 +1145,57 @@
to this qdisc, (optionally) tests for protocol and asks
specific classifiers.
*/
+int tc_classify_compat(struct sk_buff *skb, struct tcf_proto *tp,
+ struct tcf_result *res)
+{
+ __be16 protocol = skb->protocol;
+ int err = 0;
+
+ for (; tp; tp = tp->next) {
+ if ((tp->protocol == protocol ||
+ tp->protocol == htons(ETH_P_ALL)) &&
+ (err = tp->classify(skb, tp, res)) >= 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
+ return err;
+ }
+ }
+ return -1;
+}
+EXPORT_SYMBOL(tc_classify_compat);
+
int tc_classify(struct sk_buff *skb, struct tcf_proto *tp,
- struct tcf_result *res)
+ struct tcf_result *res)
{
int err = 0;
- __be16 protocol = skb->protocol;
+ __be16 protocol;
#ifdef CONFIG_NET_CLS_ACT
struct tcf_proto *otp = tp;
reclassify:
#endif
protocol = skb->protocol;
- for ( ; tp; tp = tp->next) {
- if ((tp->protocol == protocol ||
- tp->protocol == htons(ETH_P_ALL)) &&
- (err = tp->classify(skb, tp, res)) >= 0) {
+ err = tc_classify_compat(skb, tp, res);
#ifdef CONFIG_NET_CLS_ACT
- if ( TC_ACT_RECLASSIFY == err) {
- __u32 verd = (__u32) G_TC_VERD(skb->tc_verd);
- tp = otp;
+ if (err == TC_ACT_RECLASSIFY) {
+ u32 verd = G_TC_VERD(skb->tc_verd);
+ tp = otp;
- if (MAX_REC_LOOP < verd++) {
- printk("rule prio %d protocol %02x reclassify is buggy packet dropped\n",
- tp->prio&0xffff, ntohs(tp->protocol));
- return TC_ACT_SHOT;
- }
- skb->tc_verd = SET_TC_VERD(skb->tc_verd,verd);
- goto reclassify;
- } else {
- if (skb->tc_verd)
- skb->tc_verd = SET_TC_VERD(skb->tc_verd,0);
- return err;
- }
-#else
-
- return err;
-#endif
+ if (verd++ >= MAX_REC_LOOP) {
+ printk("rule prio %u protocol %02x reclassify loop, "
+ "packet dropped\n",
+ tp->prio&0xffff, ntohs(tp->protocol));
+ return TC_ACT_SHOT;
}
-
+ skb->tc_verd = SET_TC_VERD(skb->tc_verd, verd);
+ goto reclassify;
}
- return -1;
+#endif
+ return err;
}
+EXPORT_SYMBOL(tc_classify);
void tcf_destroy(struct tcf_proto *tp)
{
@@ -1252,4 +1262,3 @@
EXPORT_SYMBOL(qdisc_put_rtab);
EXPORT_SYMBOL(register_qdisc);
EXPORT_SYMBOL(unregister_qdisc);
-EXPORT_SYMBOL(tc_classify);