- 根目录:
- net
- sched
- sch_dsmark.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 mask_value {
u8 mask;
u8 value;
};
struct dsmark_qdisc_data {
struct Qdisc *q;
struct tcf_proto __rcu *filter_list;
struct mask_value *mv;
u16 indices;
u8 set_tc_index;
u32 default_index; /* index range is 0...0xffff */
#define DSMARK_EMBEDDED_SZ 16
struct mask_value embedded[DSMARK_EMBEDDED_SZ];
};
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("%s(sch %p,[qdisc %p],new %p,old %p)\n",
__func__, 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("%s(sch %p,[qdisc %p],classid %x)\n",
__func__, 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;
pr_debug("%s(sch %p,[qdisc %p],classid %x,parent %x), arg 0x%lx\n",
__func__, 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_VALUE])
p->mv[*arg - 1].value = nla_get_u8(tb[TCA_DSMARK_VALUE]);
if (tb[TCA_DSMARK_MASK])
p->mv[*arg - 1].mask = nla_get_u8(tb[TCA_DSMARK_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->mv[arg - 1].mask = 0xff;
p->mv[arg - 1].value = 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("%s(sch %p,[qdisc %p],walker %p)\n",
__func__, sch, p, walker);
if (walker->stop)
return;
for (i = 0; i < p->indices; i++) {
if (p->mv[i].mask == 0xff && !p->mv[i].value)
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 __rcu **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("%s(skb %p,sch %p,[qdisc %p])\n", __func__, skb, sch, p);
if (p->set_tc_index) {
switch (tc_skb_protocol(skb)) {
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;
struct tcf_proto *fl = rcu_dereference_bh(p->filter_list);
int result = tc_classify(skb, fl, &res, false);
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))
qdisc_qstats_drop(sch);
return err;
}
sch->q.qlen++;
return NET_XMIT_SUCCESS;
drop:
qdisc_drop(skb, sch);
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("%s(sch %p,[qdisc %p])\n", __func__, 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 (tc_skb_protocol(skb)) {
case htons(ETH_P_IP):
ipv4_change_dsfield(ip_hdr(skb), p->mv[index].mask,
p->mv[index].value);
break;
case htons(ETH_P_IPV6):
ipv6_change_dsfield(ipv6_hdr(skb), p->mv[index].mask,
p->mv[index].value);
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->mv[index].mask != 0xff || p->mv[index].value)
pr_warn("%s: unsupported protocol %d\n",
__func__, ntohs(tc_skb_protocol(skb)));
break;
}
return skb;
}
static struct sk_buff *dsmark_peek(struct Qdisc *sch)
{
struct dsmark_qdisc_data *p = qdisc_priv(sch);
pr_debug("%s(sch %p,[qdisc %p])\n", __func__, 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("%s(sch %p,[qdisc %p])\n", __func__, 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;
int i;
pr_debug("%s(sch %p,[qdisc %p],opt %p)\n", __func__, 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]);
if (indices <= DSMARK_EMBEDDED_SZ)
p->mv = p->embedded;
else
p->mv = kmalloc_array(indices, sizeof(*p->mv), GFP_KERNEL);
if (!p->mv) {
err = -ENOMEM;
goto errout;
}
for (i = 0; i < indices; i++) {
p->mv[i].mask = 0xff;
p->mv[i].value = 0;
}
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("%s: qdisc %p\n", __func__, p->q);
err = 0;
errout:
return err;
}
static void dsmark_reset(struct Qdisc *sch)
{
struct dsmark_qdisc_data *p = qdisc_priv(sch);
pr_debug("%s(sch %p,[qdisc %p])\n", __func__, 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("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
tcf_destroy_chain(&p->filter_list);
qdisc_destroy(p->q);
if (p->mv != p->embedded)
kfree(p->mv);
}
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("%s(sch %p,[qdisc %p],class %ld\n", __func__, 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;
if (nla_put_u8(skb, TCA_DSMARK_MASK, p->mv[cl - 1].mask) ||
nla_put_u8(skb, TCA_DSMARK_VALUE, p->mv[cl - 1].value))
goto nla_put_failure;
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;
if (nla_put_u16(skb, TCA_DSMARK_INDICES, p->indices))
goto nla_put_failure;
if (p->default_index != NO_DEFAULT_INDEX &&
nla_put_u16(skb, TCA_DSMARK_DEFAULT_INDEX, p->default_index))
goto nla_put_failure;
if (p->set_tc_index &&
nla_put_flag(skb, TCA_DSMARK_SET_TC_INDEX))
goto nla_put_failure;
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");