net_sched: Add size table for qdiscs

Add size table functions for qdiscs and calculate packet size in
qdisc_enqueue().

Based on patch by Patrick McHardy
 http://marc.info/?l=linux-netdev&m=115201979221729&w=2

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/pkt_sched.h b/include/linux/pkt_sched.h
index 87f4e0f..e5de421 100644
--- a/include/linux/pkt_sched.h
+++ b/include/linux/pkt_sched.h
@@ -85,6 +85,26 @@
 
 #define TC_RTAB_SIZE	1024
 
+struct tc_sizespec {
+	unsigned char	cell_log;
+	unsigned char	size_log;
+	short		cell_align;
+	int		overhead;
+	unsigned int	linklayer;
+	unsigned int	mpu;
+	unsigned int	mtu;
+	unsigned int	tsize;
+};
+
+enum {
+	TCA_STAB_UNSPEC,
+	TCA_STAB_BASE,
+	TCA_STAB_DATA,
+	__TCA_STAB_MAX
+};
+
+#define TCA_STAB_MAX (__TCA_STAB_MAX - 1)
+
 /* FIFO section */
 
 struct tc_fifo_qopt
diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index b358c70..f4d386c 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -482,6 +482,7 @@
 	TCA_RATE,
 	TCA_FCNT,
 	TCA_STATS2,
+	TCA_STAB,
 	__TCA_MAX
 };
 
diff --git a/include/net/pkt_sched.h b/include/net/pkt_sched.h
index e4e3005..6affcfa 100644
--- a/include/net/pkt_sched.h
+++ b/include/net/pkt_sched.h
@@ -83,6 +83,7 @@
 extern struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
 		struct nlattr *tab);
 extern void qdisc_put_rtab(struct qdisc_rate_table *tab);
+extern void qdisc_put_stab(struct qdisc_size_table *tab);
 
 extern void __qdisc_run(struct Qdisc *q);
 
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index 8229520..db9ad65 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -29,6 +29,13 @@
 	__QDISC_STATE_SCHED,
 };
 
+struct qdisc_size_table {
+	struct list_head	list;
+	struct tc_sizespec	szopts;
+	int			refcnt;
+	u16			data[];
+};
+
 struct Qdisc
 {
 	int 			(*enqueue)(struct sk_buff *skb, struct Qdisc *dev);
@@ -39,6 +46,7 @@
 #define TCQ_F_INGRESS	4
 	int			padded;
 	struct Qdisc_ops	*ops;
+	struct qdisc_size_table	*stab;
 	u32			handle;
 	u32			parent;
 	atomic_t		refcnt;
@@ -165,6 +173,16 @@
 	struct tcf_proto_ops	*ops;
 };
 
+struct qdisc_skb_cb {
+	unsigned int		pkt_len;
+	char			data[];
+};
+
+static inline struct qdisc_skb_cb *qdisc_skb_cb(struct sk_buff *skb)
+{
+	return (struct qdisc_skb_cb *)skb->cb;
+}
+
 static inline spinlock_t *qdisc_lock(struct Qdisc *qdisc)
 {
 	return &qdisc->q.lock;
@@ -257,6 +275,8 @@
 extern struct Qdisc *qdisc_create_dflt(struct net_device *dev,
 				       struct netdev_queue *dev_queue,
 				       struct Qdisc_ops *ops, u32 parentid);
+extern void qdisc_calculate_pkt_len(struct sk_buff *skb,
+				   struct qdisc_size_table *stab);
 extern void tcf_destroy(struct tcf_proto *tp);
 extern void tcf_destroy_chain(struct tcf_proto **fl);
 
@@ -308,16 +328,19 @@
 
 static inline unsigned int qdisc_pkt_len(struct sk_buff *skb)
 {
-	return skb->len;
+	return qdisc_skb_cb(skb)->pkt_len;
 }
 
 static inline int qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch)
 {
+	if (sch->stab)
+		qdisc_calculate_pkt_len(skb, sch->stab);
 	return sch->enqueue(skb, sch);
 }
 
 static inline int qdisc_enqueue_root(struct sk_buff *skb, struct Qdisc *sch)
 {
+	qdisc_skb_cb(skb)->pkt_len = skb->len;
 	return qdisc_enqueue(skb, sch);
 }