net: Make qdisc_skb_cb upper size bound explicit.

Just like skb->cb[], so that qdisc_skb_cb can be encapsulated inside
of other data structures.

This is intended to be used by IPoIB so that it can remember
addressing information stored at hard_header_ops->create() time that
it can fetch when the packet gets to the transmit routine.

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index f6bb08b73ca4c81a923a2d575801c5a38940efa4..55ce96b53b092e3ca04db6eaa7d6888fb9f478bc 100644 (file)
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -220,9 +220,16 @@ struct tcf_proto {
 
 struct qdisc_skb_cb {
        unsigned int            pkt_len;
-       long                    data[];
+       unsigned char           data[24];
 };
 
+static inline void qdisc_cb_private_validate(const struct sk_buff *skb, int sz)
+{
+       struct qdisc_skb_cb *qcb;
+       BUILD_BUG_ON(sizeof(skb->cb) < sizeof(unsigned int) + sz);
+       BUILD_BUG_ON(sizeof(qcb->data) < sz);
+}
+
 static inline int qdisc_qlen(const struct Qdisc *q)
 {
        return q->q.qlen;

diff --git a/net/sched/sch_choke.c b/net/sched/sch_choke.c
index e465064d39a369aad077f8ed55a54fd1f1cac31d..7e267d7b9c75730ef8351798ec1540b92e31f101 100644 (file)
--- a/net/sched/sch_choke.c
+++ b/net/sched/sch_choke.c
@@ -148,8 +148,7 @@ struct choke_skb_cb {
 
 static inline struct choke_skb_cb *choke_skb_cb(const struct sk_buff *skb)
 {
-       BUILD_BUG_ON(sizeof(skb->cb) <
-               sizeof(struct qdisc_skb_cb) + sizeof(struct choke_skb_cb));
+       qdisc_cb_private_validate(skb, sizeof(struct choke_skb_cb));
        return (struct choke_skb_cb *)qdisc_skb_cb(skb)->data;
 }
 

diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index 2776012132ea2b6448e5b0dadf1d6dd729b13afa..e83d61ca78cab71c7a54c22b7d09cc94611726a8 100644 (file)
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -130,8 +130,7 @@ struct netem_skb_cb {
 
 static inline struct netem_skb_cb *netem_skb_cb(struct sk_buff *skb)
 {
-       BUILD_BUG_ON(sizeof(skb->cb) <
-               sizeof(struct qdisc_skb_cb) + sizeof(struct netem_skb_cb));
+       qdisc_cb_private_validate(skb, sizeof(struct netem_skb_cb));
        return (struct netem_skb_cb *)qdisc_skb_cb(skb)->data;
 }
 

diff --git a/net/sched/sch_sfb.c b/net/sched/sch_sfb.c
index 96e42cae4c7a4580e753c41b9c4f1e5c29cabbcd..d7eea99333e96a33a953106a3a0f2fdb32a12385 100644 (file)
--- a/net/sched/sch_sfb.c
+++ b/net/sched/sch_sfb.c
@@ -94,8 +94,7 @@ struct sfb_skb_cb {
 
 static inline struct sfb_skb_cb *sfb_skb_cb(const struct sk_buff *skb)
 {
-       BUILD_BUG_ON(sizeof(skb->cb) <
-               sizeof(struct qdisc_skb_cb) + sizeof(struct sfb_skb_cb));
+       qdisc_cb_private_validate(skb, sizeof(struct sfb_skb_cb));
        return (struct sfb_skb_cb *)qdisc_skb_cb(skb)->data;
 }
 

diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c
index 67494aef9acf3c230aa80dd4d70d1369a5318c04..60d47180f0432e0d65c92ef5a6f6cf865b29a3c0 100644 (file)
--- a/net/sched/sch_sfq.c
+++ b/net/sched/sch_sfq.c
@@ -166,9 +166,8 @@ struct sfq_skb_cb {
 
 static inline struct sfq_skb_cb *sfq_skb_cb(const struct sk_buff *skb)
 {
-       BUILD_BUG_ON(sizeof(skb->cb) <
-               sizeof(struct qdisc_skb_cb) + sizeof(struct sfq_skb_cb));
-       return (struct sfq_skb_cb *)qdisc_skb_cb(skb)->data;
+       qdisc_cb_private_validate(skb, sizeof(struct sfq_skb_cb));
+       return (struct sfq_skb_cb *)qdisc_skb_cb(skb)->data;
 }
 
 static unsigned int sfq_hash(const struct sfq_sched_data *q,