aha/net/sched/sch_ingress.c
Patrick McHardy de6d5cdf88 net_sched: make cls_ops->change and cls_ops->delete optional
Some schedulers don't support creating, changing or deleting classes.
Make the respective callbacks optionally and consistently return
-EOPNOTSUPP for unsupported operations, instead of currently either
-EOPNOTSUPP, -ENOSYS or no error.

In case of sch_prio and sch_multiq, the removed operations additionally
checked for an invalid class. This is not necessary since the class
argument can only orginate from ->get() or in case of ->change is 0
for creation of new classes, in which case ->change() incorrectly
returned -ENOENT.

As a side-effect, this patch fixes a possible (root-only) NULL pointer
function call in sch_ingress, which didn't implement a so far mandatory
->delete() operation.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-06 02:07:02 -07:00

145 lines
3.2 KiB
C

/* net/sched/sch_ingress.c - Ingress qdisc
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Authors: Jamal Hadi Salim 1999
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
struct ingress_qdisc_data {
struct tcf_proto *filter_list;
};
/* ------------------------- Class/flow operations ------------------------- */
static struct Qdisc *ingress_leaf(struct Qdisc *sch, unsigned long arg)
{
return NULL;
}
static unsigned long ingress_get(struct Qdisc *sch, u32 classid)
{
return TC_H_MIN(classid) + 1;
}
static unsigned long ingress_bind_filter(struct Qdisc *sch,
unsigned long parent, u32 classid)
{
return ingress_get(sch, classid);
}
static void ingress_put(struct Qdisc *sch, unsigned long cl)
{
}
static void ingress_walk(struct Qdisc *sch, struct qdisc_walker *walker)
{
return;
}
static struct tcf_proto **ingress_find_tcf(struct Qdisc *sch, unsigned long cl)
{
struct ingress_qdisc_data *p = qdisc_priv(sch);
return &p->filter_list;
}
/* --------------------------- Qdisc operations ---------------------------- */
static int ingress_enqueue(struct sk_buff *skb, struct Qdisc *sch)
{
struct ingress_qdisc_data *p = qdisc_priv(sch);
struct tcf_result res;
int result;
result = tc_classify(skb, p->filter_list, &res);
sch->bstats.packets++;
sch->bstats.bytes += qdisc_pkt_len(skb);
switch (result) {
case TC_ACT_SHOT:
result = TC_ACT_SHOT;
sch->qstats.drops++;
break;
case TC_ACT_STOLEN:
case TC_ACT_QUEUED:
result = TC_ACT_STOLEN;
break;
case TC_ACT_RECLASSIFY:
case TC_ACT_OK:
skb->tc_index = TC_H_MIN(res.classid);
default:
result = TC_ACT_OK;
break;
}
return result;
}
/* ------------------------------------------------------------- */
static void ingress_destroy(struct Qdisc *sch)
{
struct ingress_qdisc_data *p = qdisc_priv(sch);
tcf_destroy_chain(&p->filter_list);
}
static int ingress_dump(struct Qdisc *sch, struct sk_buff *skb)
{
struct nlattr *nest;
nest = nla_nest_start(skb, TCA_OPTIONS);
if (nest == NULL)
goto nla_put_failure;
nla_nest_end(skb, nest);
return skb->len;
nla_put_failure:
nla_nest_cancel(skb, nest);
return -1;
}
static const struct Qdisc_class_ops ingress_class_ops = {
.leaf = ingress_leaf,
.get = ingress_get,
.put = ingress_put,
.walk = ingress_walk,
.tcf_chain = ingress_find_tcf,
.bind_tcf = ingress_bind_filter,
.unbind_tcf = ingress_put,
};
static struct Qdisc_ops ingress_qdisc_ops __read_mostly = {
.cl_ops = &ingress_class_ops,
.id = "ingress",
.priv_size = sizeof(struct ingress_qdisc_data),
.enqueue = ingress_enqueue,
.destroy = ingress_destroy,
.dump = ingress_dump,
.owner = THIS_MODULE,
};
static int __init ingress_module_init(void)
{
return register_qdisc(&ingress_qdisc_ops);
}
static void __exit ingress_module_exit(void)
{
unregister_qdisc(&ingress_qdisc_ops);
}
module_init(ingress_module_init)
module_exit(ingress_module_exit)
MODULE_LICENSE("GPL");