[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>

1 files changed, 21 insertions, 18 deletions

diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c
index b184c3545145..77381f1c6541 100644
--- a/net/sched/sch_cbq.c
+++ b/net/sched/sch_cbq.c
@@ -82,7 +82,7 @@ struct cbq_class
         unsigned char           priority2;      /* priority to be used after overlimit */
         unsigned char           ewma_log;       /* time constant for idle time calculation */
         unsigned char           ovl_strategy;
-#ifdef CONFIG_NET_CLS_POLICE
+#if defined(CONFIG_NET_CLS_ACT) || defined(CONFIG_NET_CLS_POLICE)
         unsigned char           police;
 #endif
 
@@ -154,7 +154,7 @@ struct cbq_sched_data
         struct cbq_class        *active[TC_CBQ_MAXPRIO+1];      /* List of all classes
                                                                    with backlog */
 
-#ifdef CONFIG_NET_CLS_POLICE
+#if defined(CONFIG_NET_CLS_ACT) || defined(CONFIG_NET_CLS_POLICE)
         struct cbq_class        *rx_class;
 #endif
         struct cbq_class        *tx_class;
@@ -196,7 +196,7 @@ cbq_class_lookup(struct cbq_sched_data *q, u32 classid)
         return NULL;
 }
 
-#ifdef CONFIG_NET_CLS_POLICE
+#if defined(CONFIG_NET_CLS_ACT) || defined(CONFIG_NET_CLS_POLICE)
 
 static struct cbq_class *
 cbq_reclassify(struct sk_buff *skb, struct cbq_class *this)
@@ -247,7 +247,8 @@ cbq_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
                 /*
                  * Step 2+n. Apply classifier.
                  */
-                if (!head->filter_list || (result = tc_classify(skb, head->filter_list, &res)) < 0)
+                if (!head->filter_list ||
+                    (result = tc_classify_compat(skb, head->filter_list, &res)) < 0)
                         goto fallback;
 
                 if ((cl = (void*)res.class) == NULL) {
@@ -267,6 +268,8 @@ cbq_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr)
                         *qerr = NET_XMIT_SUCCESS;
                 case TC_ACT_SHOT:
                         return NULL;
+                case TC_ACT_RECLASSIFY:
+                        return cbq_reclassify(skb, cl);
                 }
 #elif defined(CONFIG_NET_CLS_POLICE)
                 switch (result) {
@@ -389,7 +392,7 @@ cbq_enqueue(struct sk_buff *skb, struct Qdisc *sch)
         int ret;
         struct cbq_class *cl = cbq_classify(skb, sch, &ret);
 
-#ifdef CONFIG_NET_CLS_POLICE
+#if defined(CONFIG_NET_CLS_ACT) || defined(CONFIG_NET_CLS_POLICE)
         q->rx_class = cl;
 #endif
         if (cl == NULL) {
@@ -399,7 +402,7 @@ cbq_enqueue(struct sk_buff *skb, struct Qdisc *sch)
                 return ret;
         }
 
-#ifdef CONFIG_NET_CLS_POLICE
+#if defined(CONFIG_NET_CLS_ACT) || defined(CONFIG_NET_CLS_POLICE)
         cl->q->__parent = sch;
 #endif
         if ((ret = cl->q->enqueue(skb, cl->q)) == NET_XMIT_SUCCESS) {
@@ -434,7 +437,7 @@ cbq_requeue(struct sk_buff *skb, struct Qdisc *sch)
 
         cbq_mark_toplevel(q, cl);
 
-#ifdef CONFIG_NET_CLS_POLICE
+#if defined(CONFIG_NET_CLS_ACT) || defined(CONFIG_NET_CLS_POLICE)
         q->rx_class = cl;
         cl->q->__parent = sch;
 #endif
@@ -670,7 +673,7 @@ static enum hrtimer_restart cbq_undelay(struct hrtimer *timer)
 }
 
 
-#ifdef CONFIG_NET_CLS_POLICE
+#if defined(CONFIG_NET_CLS_ACT) || defined(CONFIG_NET_CLS_POLICE)
 
 static int cbq_reshape_fail(struct sk_buff *skb, struct Qdisc *child)
 {
@@ -1364,7 +1367,7 @@ static int cbq_set_overlimit(struct cbq_class *cl, struct tc_cbq_ovl *ovl)
         return 0;
 }
 
-#ifdef CONFIG_NET_CLS_POLICE
+#if defined(CONFIG_NET_CLS_ACT) || defined(CONFIG_NET_CLS_POLICE)
 static int cbq_set_police(struct cbq_class *cl, struct tc_cbq_police *p)
 {
         cl->police = p->police;
@@ -1532,7 +1535,7 @@ rtattr_failure:
         return -1;
 }
 
-#ifdef CONFIG_NET_CLS_POLICE
+#if defined(CONFIG_NET_CLS_ACT) || defined(CONFIG_NET_CLS_POLICE)
 static __inline__ int cbq_dump_police(struct sk_buff *skb, struct cbq_class *cl)
 {
         unsigned char *b = skb_tail_pointer(skb);
@@ -1558,7 +1561,7 @@ static int cbq_dump_attr(struct sk_buff *skb, struct cbq_class *cl)
             cbq_dump_rate(skb, cl) < 0 ||
             cbq_dump_wrr(skb, cl) < 0 ||
             cbq_dump_ovl(skb, cl) < 0 ||
-#ifdef CONFIG_NET_CLS_POLICE
+#if defined(CONFIG_NET_CLS_ACT) || defined(CONFIG_NET_CLS_POLICE)
             cbq_dump_police(skb, cl) < 0 ||
 #endif
             cbq_dump_fopt(skb, cl) < 0)
@@ -1653,7 +1656,7 @@ static int cbq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
                                                      cl->classid)) == NULL)
                                 return -ENOBUFS;
                 } else {
-#ifdef CONFIG_NET_CLS_POLICE
+#if defined(CONFIG_NET_CLS_ACT) || defined(CONFIG_NET_CLS_POLICE)
                         if (cl->police == TC_POLICE_RECLASSIFY)
                                 new->reshape_fail = cbq_reshape_fail;
 #endif
@@ -1718,7 +1721,7 @@ cbq_destroy(struct Qdisc* sch)
         struct cbq_class *cl;
         unsigned h;
 
-#ifdef CONFIG_NET_CLS_POLICE
+#if defined(CONFIG_NET_CLS_ACT) || defined(CONFIG_NET_CLS_POLICE)
         q->rx_class = NULL;
 #endif
         /*
@@ -1747,7 +1750,7 @@ static void cbq_put(struct Qdisc *sch, unsigned long arg)
         struct cbq_class *cl = (struct cbq_class*)arg;
 
         if (--cl->refcnt == 0) {
-#ifdef CONFIG_NET_CLS_POLICE
+#if defined(CONFIG_NET_CLS_ACT) || defined(CONFIG_NET_CLS_POLICE)
                 struct cbq_sched_data *q = qdisc_priv(sch);
 
                 spin_lock_bh(&sch->dev->queue_lock);
@@ -1795,7 +1798,7 @@ cbq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct rtattr **t
             RTA_PAYLOAD(tb[TCA_CBQ_WRROPT-1]) < sizeof(struct tc_cbq_wrropt))
                         return -EINVAL;
 
-#ifdef CONFIG_NET_CLS_POLICE
+#if defined(CONFIG_NET_CLS_ACT) || defined(CONFIG_NET_CLS_POLICE)
         if (tb[TCA_CBQ_POLICE-1] &&
             RTA_PAYLOAD(tb[TCA_CBQ_POLICE-1]) < sizeof(struct tc_cbq_police))
                         return -EINVAL;
@@ -1838,7 +1841,7 @@ cbq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct rtattr **t
                 if (tb[TCA_CBQ_OVL_STRATEGY-1])
                         cbq_set_overlimit(cl, RTA_DATA(tb[TCA_CBQ_OVL_STRATEGY-1]));
 
-#ifdef CONFIG_NET_CLS_POLICE
+#if defined(CONFIG_NET_CLS_ACT) || defined(CONFIG_NET_CLS_POLICE)
                 if (tb[TCA_CBQ_POLICE-1])
                         cbq_set_police(cl, RTA_DATA(tb[TCA_CBQ_POLICE-1]));
 #endif
@@ -1931,7 +1934,7 @@ cbq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct rtattr **t
         cl->overlimit = cbq_ovl_classic;
         if (tb[TCA_CBQ_OVL_STRATEGY-1])
                 cbq_set_overlimit(cl, RTA_DATA(tb[TCA_CBQ_OVL_STRATEGY-1]));
-#ifdef CONFIG_NET_CLS_POLICE
+#if defined(CONFIG_NET_CLS_ACT) || defined(CONFIG_NET_CLS_POLICE)
         if (tb[TCA_CBQ_POLICE-1])
                 cbq_set_police(cl, RTA_DATA(tb[TCA_CBQ_POLICE-1]));
 #endif
@@ -1975,7 +1978,7 @@ static int cbq_delete(struct Qdisc *sch, unsigned long arg)
                 q->tx_class = NULL;
                 q->tx_borrowed = NULL;
         }
-#ifdef CONFIG_NET_CLS_POLICE
+#if defined(CONFIG_NET_CLS_ACT) || defined(CONFIG_NET_CLS_POLICE)
         if (q->rx_class == cl)
                 q->rx_class = NULL;
 #endif