linux/net/sched/sch_dsmark.c
Eric Dumazet 9190b3b320 net_sched: accurate bytes/packets stats/rates
In commit 44b8288308 (net_sched: pfifo_head_drop problem), we fixed
a problem with pfifo_head drops that incorrectly decreased
sch->bstats.bytes and sch->bstats.packets

Several qdiscs (CHOKe, SFQ, pfifo_head, ...) are able to drop a
previously enqueued packet, and bstats cannot be changed, so
bstats/rates are not accurate (over estimated)

This patch changes the qdisc_bstats updates to be done at dequeue() time
instead of enqueue() time. bstats counters no longer account for dropped
frames, and rates are more correct, since enqueue() bursts dont have
effect on dequeue() rate.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-20 23:31:33 -08:00

511 lines
11 KiB
C

/* net/sched/sch_dsmark.c - Differentiated Services field marker */
/* Written 1998-2000 by Werner Almesberger, EPFL ICA */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <linux/bitops.h>
#include <net/pkt_sched.h>
#include <net/dsfield.h>
#include <net/inet_ecn.h>
#include <asm/byteorder.h>
/*
* classid class marking
* ------- ----- -------
* n/a 0 n/a
* x:0 1 use entry [0]
* ... ... ...
* x:y y>0 y+1 use entry [y]
* ... ... ...
* x:indices-1 indices use entry [indices-1]
* ... ... ...
* x:y y+1 use entry [y & (indices-1)]
* ... ... ...
* 0xffff 0x10000 use entry [indices-1]
*/
#define NO_DEFAULT_INDEX (1 << 16)
struct dsmark_qdisc_data {
struct Qdisc *q;
struct tcf_proto *filter_list;
u8 *mask; /* "owns" the array */
u8 *value;
u16 indices;
u32 default_index; /* index range is 0...0xffff */
int set_tc_index;
};
static inline int dsmark_valid_index(struct dsmark_qdisc_data *p, u16 index)
{
return (index <= p->indices && index > 0);
}
/* ------------------------- Class/flow operations ------------------------- */
static int dsmark_graft(struct Qdisc *sch, unsigned long arg,
struct Qdisc *new, struct Qdisc **old)
{
struct dsmark_qdisc_data *p = qdisc_priv(sch);
pr_debug("dsmark_graft(sch %p,[qdisc %p],new %p,old %p)\n",
sch, p, new, old);
if (new == NULL) {
new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
sch->handle);
if (new == NULL)
new = &noop_qdisc;
}
sch_tree_lock(sch);
*old = p->q;
p->q = new;
qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
qdisc_reset(*old);
sch_tree_unlock(sch);
return 0;
}
static struct Qdisc *dsmark_leaf(struct Qdisc *sch, unsigned long arg)
{
struct dsmark_qdisc_data *p = qdisc_priv(sch);
return p->q;
}
static unsigned long dsmark_get(struct Qdisc *sch, u32 classid)
{
pr_debug("dsmark_get(sch %p,[qdisc %p],classid %x)\n",
sch, qdisc_priv(sch), classid);
return TC_H_MIN(classid) + 1;
}
static unsigned long dsmark_bind_filter(struct Qdisc *sch,
unsigned long parent, u32 classid)
{
return dsmark_get(sch, classid);
}
static void dsmark_put(struct Qdisc *sch, unsigned long cl)
{
}
static const struct nla_policy dsmark_policy[TCA_DSMARK_MAX + 1] = {
[TCA_DSMARK_INDICES] = { .type = NLA_U16 },
[TCA_DSMARK_DEFAULT_INDEX] = { .type = NLA_U16 },
[TCA_DSMARK_SET_TC_INDEX] = { .type = NLA_FLAG },
[TCA_DSMARK_MASK] = { .type = NLA_U8 },
[TCA_DSMARK_VALUE] = { .type = NLA_U8 },
};
static int dsmark_change(struct Qdisc *sch, u32 classid, u32 parent,
struct nlattr **tca, unsigned long *arg)
{
struct dsmark_qdisc_data *p = qdisc_priv(sch);
struct nlattr *opt = tca[TCA_OPTIONS];
struct nlattr *tb[TCA_DSMARK_MAX + 1];
int err = -EINVAL;
u8 mask = 0;
pr_debug("dsmark_change(sch %p,[qdisc %p],classid %x,parent %x),"
"arg 0x%lx\n", sch, p, classid, parent, *arg);
if (!dsmark_valid_index(p, *arg)) {
err = -ENOENT;
goto errout;
}
if (!opt)
goto errout;
err = nla_parse_nested(tb, TCA_DSMARK_MAX, opt, dsmark_policy);
if (err < 0)
goto errout;
if (tb[TCA_DSMARK_MASK])
mask = nla_get_u8(tb[TCA_DSMARK_MASK]);
if (tb[TCA_DSMARK_VALUE])
p->value[*arg-1] = nla_get_u8(tb[TCA_DSMARK_VALUE]);
if (tb[TCA_DSMARK_MASK])
p->mask[*arg-1] = mask;
err = 0;
errout:
return err;
}
static int dsmark_delete(struct Qdisc *sch, unsigned long arg)
{
struct dsmark_qdisc_data *p = qdisc_priv(sch);
if (!dsmark_valid_index(p, arg))
return -EINVAL;
p->mask[arg-1] = 0xff;
p->value[arg-1] = 0;
return 0;
}
static void dsmark_walk(struct Qdisc *sch, struct qdisc_walker *walker)
{
struct dsmark_qdisc_data *p = qdisc_priv(sch);
int i;
pr_debug("dsmark_walk(sch %p,[qdisc %p],walker %p)\n", sch, p, walker);
if (walker->stop)
return;
for (i = 0; i < p->indices; i++) {
if (p->mask[i] == 0xff && !p->value[i])
goto ignore;
if (walker->count >= walker->skip) {
if (walker->fn(sch, i+1, walker) < 0) {
walker->stop = 1;
break;
}
}
ignore:
walker->count++;
}
}
static inline struct tcf_proto **dsmark_find_tcf(struct Qdisc *sch,
unsigned long cl)
{
struct dsmark_qdisc_data *p = qdisc_priv(sch);
return &p->filter_list;
}
/* --------------------------- Qdisc operations ---------------------------- */
static int dsmark_enqueue(struct sk_buff *skb, struct Qdisc *sch)
{
struct dsmark_qdisc_data *p = qdisc_priv(sch);
int err;
pr_debug("dsmark_enqueue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);
if (p->set_tc_index) {
switch (skb->protocol) {
case htons(ETH_P_IP):
if (skb_cow_head(skb, sizeof(struct iphdr)))
goto drop;
skb->tc_index = ipv4_get_dsfield(ip_hdr(skb))
& ~INET_ECN_MASK;
break;
case htons(ETH_P_IPV6):
if (skb_cow_head(skb, sizeof(struct ipv6hdr)))
goto drop;
skb->tc_index = ipv6_get_dsfield(ipv6_hdr(skb))
& ~INET_ECN_MASK;
break;
default:
skb->tc_index = 0;
break;
}
}
if (TC_H_MAJ(skb->priority) == sch->handle)
skb->tc_index = TC_H_MIN(skb->priority);
else {
struct tcf_result res;
int result = tc_classify(skb, p->filter_list, &res);
pr_debug("result %d class 0x%04x\n", result, res.classid);
switch (result) {
#ifdef CONFIG_NET_CLS_ACT
case TC_ACT_QUEUED:
case TC_ACT_STOLEN:
kfree_skb(skb);
return NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
case TC_ACT_SHOT:
goto drop;
#endif
case TC_ACT_OK:
skb->tc_index = TC_H_MIN(res.classid);
break;
default:
if (p->default_index != NO_DEFAULT_INDEX)
skb->tc_index = p->default_index;
break;
}
}
err = qdisc_enqueue(skb, p->q);
if (err != NET_XMIT_SUCCESS) {
if (net_xmit_drop_count(err))
sch->qstats.drops++;
return err;
}
sch->q.qlen++;
return NET_XMIT_SUCCESS;
drop:
kfree_skb(skb);
sch->qstats.drops++;
return NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
}
static struct sk_buff *dsmark_dequeue(struct Qdisc *sch)
{
struct dsmark_qdisc_data *p = qdisc_priv(sch);
struct sk_buff *skb;
u32 index;
pr_debug("dsmark_dequeue(sch %p,[qdisc %p])\n", sch, p);
skb = p->q->ops->dequeue(p->q);
if (skb == NULL)
return NULL;
qdisc_bstats_update(sch, skb);
sch->q.qlen--;
index = skb->tc_index & (p->indices - 1);
pr_debug("index %d->%d\n", skb->tc_index, index);
switch (skb->protocol) {
case htons(ETH_P_IP):
ipv4_change_dsfield(ip_hdr(skb), p->mask[index],
p->value[index]);
break;
case htons(ETH_P_IPV6):
ipv6_change_dsfield(ipv6_hdr(skb), p->mask[index],
p->value[index]);
break;
default:
/*
* Only complain if a change was actually attempted.
* This way, we can send non-IP traffic through dsmark
* and don't need yet another qdisc as a bypass.
*/
if (p->mask[index] != 0xff || p->value[index])
printk(KERN_WARNING
"dsmark_dequeue: unsupported protocol %d\n",
ntohs(skb->protocol));
break;
}
return skb;
}
static struct sk_buff *dsmark_peek(struct Qdisc *sch)
{
struct dsmark_qdisc_data *p = qdisc_priv(sch);
pr_debug("dsmark_peek(sch %p,[qdisc %p])\n", sch, p);
return p->q->ops->peek(p->q);
}
static unsigned int dsmark_drop(struct Qdisc *sch)
{
struct dsmark_qdisc_data *p = qdisc_priv(sch);
unsigned int len;
pr_debug("dsmark_reset(sch %p,[qdisc %p])\n", sch, p);
if (p->q->ops->drop == NULL)
return 0;
len = p->q->ops->drop(p->q);
if (len)
sch->q.qlen--;
return len;
}
static int dsmark_init(struct Qdisc *sch, struct nlattr *opt)
{
struct dsmark_qdisc_data *p = qdisc_priv(sch);
struct nlattr *tb[TCA_DSMARK_MAX + 1];
int err = -EINVAL;
u32 default_index = NO_DEFAULT_INDEX;
u16 indices;
u8 *mask;
pr_debug("dsmark_init(sch %p,[qdisc %p],opt %p)\n", sch, p, opt);
if (!opt)
goto errout;
err = nla_parse_nested(tb, TCA_DSMARK_MAX, opt, dsmark_policy);
if (err < 0)
goto errout;
err = -EINVAL;
indices = nla_get_u16(tb[TCA_DSMARK_INDICES]);
if (hweight32(indices) != 1)
goto errout;
if (tb[TCA_DSMARK_DEFAULT_INDEX])
default_index = nla_get_u16(tb[TCA_DSMARK_DEFAULT_INDEX]);
mask = kmalloc(indices * 2, GFP_KERNEL);
if (mask == NULL) {
err = -ENOMEM;
goto errout;
}
p->mask = mask;
memset(p->mask, 0xff, indices);
p->value = p->mask + indices;
memset(p->value, 0, indices);
p->indices = indices;
p->default_index = default_index;
p->set_tc_index = nla_get_flag(tb[TCA_DSMARK_SET_TC_INDEX]);
p->q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, sch->handle);
if (p->q == NULL)
p->q = &noop_qdisc;
pr_debug("dsmark_init: qdisc %p\n", p->q);
err = 0;
errout:
return err;
}
static void dsmark_reset(struct Qdisc *sch)
{
struct dsmark_qdisc_data *p = qdisc_priv(sch);
pr_debug("dsmark_reset(sch %p,[qdisc %p])\n", sch, p);
qdisc_reset(p->q);
sch->q.qlen = 0;
}
static void dsmark_destroy(struct Qdisc *sch)
{
struct dsmark_qdisc_data *p = qdisc_priv(sch);
pr_debug("dsmark_destroy(sch %p,[qdisc %p])\n", sch, p);
tcf_destroy_chain(&p->filter_list);
qdisc_destroy(p->q);
kfree(p->mask);
}
static int dsmark_dump_class(struct Qdisc *sch, unsigned long cl,
struct sk_buff *skb, struct tcmsg *tcm)
{
struct dsmark_qdisc_data *p = qdisc_priv(sch);
struct nlattr *opts = NULL;
pr_debug("dsmark_dump_class(sch %p,[qdisc %p],class %ld\n", sch, p, cl);
if (!dsmark_valid_index(p, cl))
return -EINVAL;
tcm->tcm_handle = TC_H_MAKE(TC_H_MAJ(sch->handle), cl-1);
tcm->tcm_info = p->q->handle;
opts = nla_nest_start(skb, TCA_OPTIONS);
if (opts == NULL)
goto nla_put_failure;
NLA_PUT_U8(skb, TCA_DSMARK_MASK, p->mask[cl-1]);
NLA_PUT_U8(skb, TCA_DSMARK_VALUE, p->value[cl-1]);
return nla_nest_end(skb, opts);
nla_put_failure:
nla_nest_cancel(skb, opts);
return -EMSGSIZE;
}
static int dsmark_dump(struct Qdisc *sch, struct sk_buff *skb)
{
struct dsmark_qdisc_data *p = qdisc_priv(sch);
struct nlattr *opts = NULL;
opts = nla_nest_start(skb, TCA_OPTIONS);
if (opts == NULL)
goto nla_put_failure;
NLA_PUT_U16(skb, TCA_DSMARK_INDICES, p->indices);
if (p->default_index != NO_DEFAULT_INDEX)
NLA_PUT_U16(skb, TCA_DSMARK_DEFAULT_INDEX, p->default_index);
if (p->set_tc_index)
NLA_PUT_FLAG(skb, TCA_DSMARK_SET_TC_INDEX);
return nla_nest_end(skb, opts);
nla_put_failure:
nla_nest_cancel(skb, opts);
return -EMSGSIZE;
}
static const struct Qdisc_class_ops dsmark_class_ops = {
.graft = dsmark_graft,
.leaf = dsmark_leaf,
.get = dsmark_get,
.put = dsmark_put,
.change = dsmark_change,
.delete = dsmark_delete,
.walk = dsmark_walk,
.tcf_chain = dsmark_find_tcf,
.bind_tcf = dsmark_bind_filter,
.unbind_tcf = dsmark_put,
.dump = dsmark_dump_class,
};
static struct Qdisc_ops dsmark_qdisc_ops __read_mostly = {
.next = NULL,
.cl_ops = &dsmark_class_ops,
.id = "dsmark",
.priv_size = sizeof(struct dsmark_qdisc_data),
.enqueue = dsmark_enqueue,
.dequeue = dsmark_dequeue,
.peek = dsmark_peek,
.drop = dsmark_drop,
.init = dsmark_init,
.reset = dsmark_reset,
.destroy = dsmark_destroy,
.change = NULL,
.dump = dsmark_dump,
.owner = THIS_MODULE,
};
static int __init dsmark_module_init(void)
{
return register_qdisc(&dsmark_qdisc_ops);
}
static void __exit dsmark_module_exit(void)
{
unregister_qdisc(&dsmark_qdisc_ops);
}
module_init(dsmark_module_init)
module_exit(dsmark_module_exit)
MODULE_LICENSE("GPL");