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 87f4e0fa8f2749020a7fe82f46d6ca2c22564dbc..e5de421ac7b422dc2526837512183311446b0884 100644 (file)
--- a/include/linux/pkt_sched.h
+++ b/include/linux/pkt_sched.h
@@ -85,6 +85,26 @@ struct tc_ratespec
 
 #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 b358c704d10247ac0c46730f78e5db0485132f79..f4d386c191f587507dac62b17de0ea26cfe3fbee 100644 (file)
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -482,6 +482,7 @@ enum
        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 e4e30052e4e29df5b9e8dcde40e056ba35c82b17..6affcfaa123edda5df7f65275d117063ed00018d 100644 (file)
--- a/include/net/pkt_sched.h
+++ b/include/net/pkt_sched.h
@@ -83,6 +83,7 @@ extern struct Qdisc *qdisc_lookup_class(struct net_device *dev, u32 handle);
 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 8229520e088a51d7f8b4a0571ebf2ca0a925a692..db9ad655eb8aa089c1c0936f5307c1453a7c90bd 100644 (file)
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -29,6 +29,13 @@ enum qdisc_state_t
        __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 @@ struct Qdisc
 #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
        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_alloc(struct netdev_queue *dev_queue,
 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 bool qdisc_tx_is_noop(const struct net_device *dev)
 
 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);
 }
 

diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index fb43731c98605a5e144a0cf0af1f89ba2620383e..5219d5f9d75444e4a35482d2e707efcf0af2fe1d 100644 (file)
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -286,6 +286,129 @@ void qdisc_put_rtab(struct qdisc_rate_table *tab)
 }
 EXPORT_SYMBOL(qdisc_put_rtab);
 
+static LIST_HEAD(qdisc_stab_list);
+static DEFINE_SPINLOCK(qdisc_stab_lock);
+
+static const struct nla_policy stab_policy[TCA_STAB_MAX + 1] = {
+       [TCA_STAB_BASE] = { .len = sizeof(struct tc_sizespec) },
+       [TCA_STAB_DATA] = { .type = NLA_BINARY },
+};
+
+static struct qdisc_size_table *qdisc_get_stab(struct nlattr *opt)
+{
+       struct nlattr *tb[TCA_STAB_MAX + 1];
+       struct qdisc_size_table *stab;
+       struct tc_sizespec *s;
+       unsigned int tsize = 0;
+       u16 *tab = NULL;
+       int err;
+
+       err = nla_parse_nested(tb, TCA_STAB_MAX, opt, stab_policy);
+       if (err < 0)
+               return ERR_PTR(err);
+       if (!tb[TCA_STAB_BASE])
+               return ERR_PTR(-EINVAL);
+
+       s = nla_data(tb[TCA_STAB_BASE]);
+
+       if (s->tsize > 0) {
+               if (!tb[TCA_STAB_DATA])
+                       return ERR_PTR(-EINVAL);
+               tab = nla_data(tb[TCA_STAB_DATA]);
+               tsize = nla_len(tb[TCA_STAB_DATA]) / sizeof(u16);
+       }
+
+       if (!s || tsize != s->tsize || (!tab && tsize > 0))
+               return ERR_PTR(-EINVAL);
+
+       spin_lock(&qdisc_stab_lock);
+
+       list_for_each_entry(stab, &qdisc_stab_list, list) {
+               if (memcmp(&stab->szopts, s, sizeof(*s)))
+                       continue;
+               if (tsize > 0 && memcmp(stab->data, tab, tsize * sizeof(u16)))
+                       continue;
+               stab->refcnt++;
+               spin_unlock(&qdisc_stab_lock);
+               return stab;
+       }
+
+       spin_unlock(&qdisc_stab_lock);
+
+       stab = kmalloc(sizeof(*stab) + tsize * sizeof(u16), GFP_KERNEL);
+       if (!stab)
+               return ERR_PTR(-ENOMEM);
+
+       stab->refcnt = 1;
+       stab->szopts = *s;
+       if (tsize > 0)
+               memcpy(stab->data, tab, tsize * sizeof(u16));
+
+       spin_lock(&qdisc_stab_lock);
+       list_add_tail(&stab->list, &qdisc_stab_list);
+       spin_unlock(&qdisc_stab_lock);
+
+       return stab;
+}
+
+void qdisc_put_stab(struct qdisc_size_table *tab)
+{
+       if (!tab)
+               return;
+
+       spin_lock(&qdisc_stab_lock);
+
+       if (--tab->refcnt == 0) {
+               list_del(&tab->list);
+               kfree(tab);
+       }
+
+       spin_unlock(&qdisc_stab_lock);
+}
+EXPORT_SYMBOL(qdisc_put_stab);
+
+static int qdisc_dump_stab(struct sk_buff *skb, struct qdisc_size_table *stab)
+{
+       struct nlattr *nest;
+
+       nest = nla_nest_start(skb, TCA_STAB);
+       NLA_PUT(skb, TCA_STAB_BASE, sizeof(stab->szopts), &stab->szopts);
+       nla_nest_end(skb, nest);
+
+       return skb->len;
+
+nla_put_failure:
+       return -1;
+}
+
+void qdisc_calculate_pkt_len(struct sk_buff *skb, struct qdisc_size_table *stab)
+{
+       int pkt_len, slot;
+
+       pkt_len = skb->len + stab->szopts.overhead;
+       if (unlikely(!stab->szopts.tsize))
+               goto out;
+
+       slot = pkt_len + stab->szopts.cell_align;
+       if (unlikely(slot < 0))
+               slot = 0;
+
+       slot >>= stab->szopts.cell_log;
+       if (likely(slot < stab->szopts.tsize))
+               pkt_len = stab->data[slot];
+       else
+               pkt_len = stab->data[stab->szopts.tsize - 1] *
+                               (slot / stab->szopts.tsize) +
+                               stab->data[slot % stab->szopts.tsize];
+
+       pkt_len <<= stab->szopts.size_log;
+out:
+       if (unlikely(pkt_len < 1))
+               pkt_len = 1;
+       qdisc_skb_cb(skb)->pkt_len = pkt_len;
+}
+EXPORT_SYMBOL(qdisc_calculate_pkt_len);
+
 static enum hrtimer_restart qdisc_watchdog(struct hrtimer *timer)
 {
        struct qdisc_watchdog *wd = container_of(timer, struct qdisc_watchdog,
@@ -613,6 +736,7 @@ qdisc_create(struct net_device *dev, struct netdev_queue *dev_queue,
        struct nlattr *kind = tca[TCA_KIND];
        struct Qdisc *sch;
        struct Qdisc_ops *ops;
+       struct qdisc_size_table *stab;
 
        ops = qdisc_lookup_ops(kind);
 #ifdef CONFIG_KMOD
@@ -670,6 +794,14 @@ qdisc_create(struct net_device *dev, struct netdev_queue *dev_queue,
        sch->handle = handle;
 
        if (!ops->init || (err = ops->init(sch, tca[TCA_OPTIONS])) == 0) {
+               if (tca[TCA_STAB]) {
+                       stab = qdisc_get_stab(tca[TCA_STAB]);
+                       if (IS_ERR(stab)) {
+                               err = PTR_ERR(stab);
+                               goto err_out3;
+                       }
+                       sch->stab = stab;
+               }
                if (tca[TCA_RATE]) {
                        err = gen_new_estimator(&sch->bstats, &sch->rate_est,
                                                qdisc_root_lock(sch),
@@ -691,6 +823,7 @@ qdisc_create(struct net_device *dev, struct netdev_queue *dev_queue,
                return sch;
        }
 err_out3:
+       qdisc_put_stab(sch->stab);
        dev_put(dev);
        kfree((char *) sch - sch->padded);
 err_out2:
@@ -702,15 +835,26 @@ err_out:
 
 static int qdisc_change(struct Qdisc *sch, struct nlattr **tca)
 {
-       if (tca[TCA_OPTIONS]) {
-               int err;
+       struct qdisc_size_table *stab = NULL;
+       int err = 0;
 
+       if (tca[TCA_OPTIONS]) {
                if (sch->ops->change == NULL)
                        return -EINVAL;
                err = sch->ops->change(sch, tca[TCA_OPTIONS]);
                if (err)
                        return err;
        }
+
+       if (tca[TCA_STAB]) {
+               stab = qdisc_get_stab(tca[TCA_STAB]);
+               if (IS_ERR(stab))
+                       return PTR_ERR(stab);
+       }
+
+       qdisc_put_stab(sch->stab);
+       sch->stab = stab;
+
        if (tca[TCA_RATE])
                gen_replace_estimator(&sch->bstats, &sch->rate_est,
                                      qdisc_root_lock(sch), tca[TCA_RATE]);
@@ -994,6 +1138,9 @@ static int tc_fill_qdisc(struct sk_buff *skb, struct Qdisc *q, u32 clid,
                goto nla_put_failure;
        q->qstats.qlen = q->q.qlen;
 
+       if (q->stab && qdisc_dump_stab(skb, q->stab) < 0)
+               goto nla_put_failure;
+
        if (gnet_stats_start_copy_compat(skb, TCA_STATS2, TCA_STATS,
                                         TCA_XSTATS, qdisc_root_lock(q), &d) < 0)
                goto nla_put_failure;

diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 522a41a9f9049df31aa1e5b943f5dbfecefcfe82..27a51f04db49d76cbfd7c6fb307167743387c57b 100644 (file)
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -469,6 +469,7 @@ static void __qdisc_destroy(struct rcu_head *head)
        struct Qdisc *qdisc = container_of(head, struct Qdisc, q_rcu);
        const struct Qdisc_ops  *ops = qdisc->ops;
 
+       qdisc_put_stab(qdisc->stab);
        gen_kill_estimator(&qdisc->bstats, &qdisc->rate_est);
        if (ops->reset)
                ops->reset(qdisc);

diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index ae49be00022f153d830fe6327ab6adaeb79fed65..a590857006786dc7d98bac27230f79dbd2cc552c 100644 (file)
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -84,8 +84,9 @@ 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 netem_skb_cb));
-       return (struct netem_skb_cb *)skb->cb;
+       BUILD_BUG_ON(sizeof(skb->cb) <
+               sizeof(struct qdisc_skb_cb) + sizeof(struct netem_skb_cb));
+       return (struct netem_skb_cb *)qdisc_skb_cb(skb)->data;
 }
 
 /* init_crandom - initialize correlated random number generator