/*
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:
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("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])
pr_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
