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[NET_SCHED]: act_api: qdisc internal reclassify support
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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>
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Patrick McHardy authored and David S. Miller committed Jul 15, 2007
1 parent f6853e2 commit 73ca491
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Showing 6 changed files with 73 additions and 52 deletions.
4 changes: 3 additions & 1 deletion include/net/pkt_sched.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -89,8 +89,10 @@ static inline void qdisc_run(struct net_device *dev)
__qdisc_run(dev);
}

extern int tc_classify_compat(struct sk_buff *skb, struct tcf_proto *tp,
struct tcf_result *res);
extern int tc_classify(struct sk_buff *skb, struct tcf_proto *tp,
struct tcf_result *res);
struct tcf_result *res);

/* Calculate maximal size of packet seen by hard_start_xmit
routine of this device.
Expand Down
2 changes: 1 addition & 1 deletion include/net/sch_generic.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -290,7 +290,7 @@ static inline int qdisc_reshape_fail(struct sk_buff *skb, struct Qdisc *sch)
{
sch->qstats.drops++;

#ifdef CONFIG_NET_CLS_POLICE
#if defined(CONFIG_NET_CLS_ACT) || defined(CONFIG_NET_CLS_POLICE)
if (sch->reshape_fail == NULL || sch->reshape_fail(skb, sch))
goto drop;

Expand Down
67 changes: 38 additions & 29 deletions net/sched/sch_api.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1145,47 +1145,57 @@ static int tc_dump_tclass(struct sk_buff *skb, struct netlink_callback *cb)
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 (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 (err == TC_ACT_RECLASSIFY) {
u32 verd = G_TC_VERD(skb->tc_verd);
tp = otp;

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)
{
Expand Down Expand Up @@ -1252,4 +1262,3 @@ EXPORT_SYMBOL(qdisc_get_rtab);
EXPORT_SYMBOL(qdisc_put_rtab);
EXPORT_SYMBOL(register_qdisc);
EXPORT_SYMBOL(unregister_qdisc);
EXPORT_SYMBOL(tc_classify);
11 changes: 9 additions & 2 deletions net/sched/sch_atm.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -396,8 +396,9 @@ static int atm_tc_enqueue(struct sk_buff *skb, struct Qdisc *sch)
!(flow = (struct atm_flow_data *)atm_tc_get(sch, skb->priority)))
for (flow = p->flows; flow; flow = flow->next)
if (flow->filter_list) {
result = tc_classify(skb, flow->filter_list,
&res);
result = tc_classify_compat(skb,
flow->filter_list,
&res);
if (result < 0)
continue;
flow = (struct atm_flow_data *)res.class;
Expand All @@ -420,6 +421,12 @@ static int atm_tc_enqueue(struct sk_buff *skb, struct Qdisc *sch)
case TC_ACT_SHOT:
kfree_skb(skb);
goto drop;
case TC_POLICE_RECLASSIFY:
if (flow->excess)
flow = flow->excess;
else
ATM_SKB(skb)->atm_options |= ATM_ATMOPT_CLP;
break;
}
#elif defined(CONFIG_NET_CLS_POLICE)
switch (result) {
Expand Down
39 changes: 21 additions & 18 deletions net/sched/sch_cbq.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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

Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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)
Expand Down Expand Up @@ -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) {
Expand All @@ -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) {
Expand Down Expand Up @@ -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) {
Expand All @@ -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) {
Expand Down Expand Up @@ -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
Expand Down Expand Up @@ -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)
{
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -1532,7 +1535,7 @@ static __inline__ int cbq_dump_fopt(struct sk_buff *skb, struct cbq_class *cl)
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);
Expand All @@ -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)
Expand Down Expand Up @@ -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
Expand Down Expand Up @@ -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
/*
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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
Expand Down Expand Up @@ -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
Expand Down Expand Up @@ -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
Expand Down
2 changes: 1 addition & 1 deletion net/sched/sch_tbf.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -125,7 +125,7 @@ static int tbf_enqueue(struct sk_buff *skb, struct Qdisc* sch)

if (skb->len > q->max_size) {
sch->qstats.drops++;
#ifdef CONFIG_NET_CLS_POLICE
#if defined(CONFIG_NET_CLS_ACT) || defined(CONFIG_NET_CLS_POLICE)
if (sch->reshape_fail == NULL || sch->reshape_fail(skb, sch))
#endif
kfree_skb(skb);
Expand Down

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