Viewing file:  cls_tcindex.c (11.85 KB) -rw-r--r--
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/*
* net/sched/cls_tcindex.c Packet classifier for skb->tc_index
*
* Written 1998,1999 by Werner Almesberger, EPFL ICA
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <net/ip.h>
#include <net/pkt_sched.h>
#include <net/route.h>
/*
* Not quite sure if we need all the xchgs Alexey uses when accessing things.
* Can always add them later ... :)
*/
/*
* Passing parameters to the root seems to be done more awkwardly than really
* necessary. At least, u32 doesn't seem to use such dirty hacks. To be
* verified. FIXME.
*/
#define PERFECT_HASH_THRESHOLD 64 /* use perfect hash if not bigger */
#define DEFAULT_HASH_SIZE 64 /* optimized for diffserv */
#if 1 /* control */
#define DPRINTK(format,args...) printk(KERN_DEBUG format,##args)
#else
#define DPRINTK(format,args...)
#endif
#if 0 /* data */
#define D2PRINTK(format,args...) printk(KERN_DEBUG format,##args)
#else
#define D2PRINTK(format,args...)
#endif
#define PRIV(tp) ((struct tcindex_data *) (tp)->root)
struct tcindex_filter_result {
struct tcf_police *police;
struct tcf_result res;
};
struct tcindex_filter {
__u16 key;
struct tcindex_filter_result result;
struct tcindex_filter *next;
};
struct tcindex_data {
struct tcindex_filter_result *perfect; /* perfect hash; NULL if none */
struct tcindex_filter **h; /* imperfect hash; only used if !perfect;
NULL if unused */
__u16 mask; /* AND key with mask */
int shift; /* shift ANDed key to the right */
int hash; /* hash table size; 0 if undefined */
int alloc_hash; /* allocated size */
int fall_through; /* 0: only classify if explicit match */
};
static struct tcindex_filter_result *lookup(struct tcindex_data *p,__u16 key)
{
struct tcindex_filter *f;
if (p->perfect)
return p->perfect[key].res.class ? p->perfect+key : NULL;
if (!p->h)
return NULL;
for (f = p->h[key % p->hash]; f; f = f->next) {
if (f->key == key)
return &f->result;
}
return NULL;
}
static int tcindex_classify(struct sk_buff *skb, struct tcf_proto *tp,
struct tcf_result *res)
{
struct tcindex_data *p = PRIV(tp);
struct tcindex_filter_result *f;
D2PRINTK("tcindex_classify(skb %p,tp %p,res %p),p %p\n",skb,tp,res,p);
f = lookup(p,(skb->tc_index & p->mask) >> p->shift);
if (!f) {
if (!p->fall_through)
return -1;
res->classid = TC_H_MAKE(TC_H_MAJ(tp->q->handle),
(skb->tc_index& p->mask) >> p->shift);
res->class = 0;
D2PRINTK("alg 0x%x\n",res->classid);
return 0;
}
*res = f->res;
D2PRINTK("map 0x%x\n",res->classid);
#ifdef CONFIG_NET_CLS_POLICE
if (f->police) {
int result;
result = tcf_police(skb,f->police);
D2PRINTK("police %d\n",res);
return result;
}
#endif
return 0;
}
static unsigned long tcindex_get(struct tcf_proto *tp, u32 handle)
{
struct tcindex_data *p = PRIV(tp);
struct tcindex_filter_result *r;
DPRINTK("tcindex_get(tp %p,handle 0x%08x)\n",tp,handle);
if (p->perfect && handle >= p->alloc_hash)
return 0;
r = lookup(PRIV(tp),handle);
return r && r->res.class ? (unsigned long) r : 0;
}
static void tcindex_put(struct tcf_proto *tp, unsigned long f)
{
DPRINTK("tcindex_put(tp %p,f 0x%lx)\n",tp,f);
}
static int tcindex_init(struct tcf_proto *tp)
{
struct tcindex_data *p;
DPRINTK("tcindex_init(tp %p)\n",tp);
MOD_INC_USE_COUNT;
p = kmalloc(sizeof(struct tcindex_data),GFP_KERNEL);
if (!p) {
MOD_DEC_USE_COUNT;
return -ENOMEM;
}
tp->root = p;
p->perfect = NULL;
p->h = NULL;
p->hash = 0;
p->mask = 0xffff;
p->shift = 0;
p->fall_through = 1;
return 0;
}
static int tcindex_delete(struct tcf_proto *tp, unsigned long arg)
{
struct tcindex_data *p = PRIV(tp);
struct tcindex_filter_result *r = (struct tcindex_filter_result *) arg;
struct tcindex_filter *f = NULL;
unsigned long cl;
DPRINTK("tcindex_delete(tp %p,arg 0x%lx),p %p,f %p\n",tp,arg,p,f);
if (p->perfect) {
if (!r->res.class)
return -ENOENT;
} else {
int i;
struct tcindex_filter **walk = NULL;
for (i = 0; i < p->hash; i++)
for (walk = p->h+i; *walk; walk = &(*walk)->next)
if (&(*walk)->result == r)
goto found;
return -ENOENT;
found:
f = *walk;
tcf_tree_lock(tp);
*walk = f->next;
tcf_tree_unlock(tp);
}
cl = __cls_set_class(&r->res.class,0);
if (cl)
tp->q->ops->cl_ops->unbind_tcf(tp->q,cl);
#ifdef CONFIG_NET_CLS_POLICE
tcf_police_release(r->police);
#endif
if (f)
kfree(f);
return 0;
}
/*
* There are no parameters for tcindex_init, so we overload tcindex_change
*/
static int tcindex_change(struct tcf_proto *tp,unsigned long base,u32 handle,
struct rtattr **tca,unsigned long *arg)
{
struct tcindex_filter_result new_filter_result = {
NULL, /* no policing */
{ 0,0 }, /* no classification */
};
struct rtattr *opt = tca[TCA_OPTIONS-1];
struct rtattr *tb[TCA_TCINDEX_MAX];
struct tcindex_data *p = PRIV(tp);
struct tcindex_filter *f;
struct tcindex_filter_result *r = (struct tcindex_filter_result *) *arg;
struct tcindex_filter **walk;
int hash,shift;
__u16 mask;
DPRINTK("tcindex_change(tp %p,handle 0x%08x,tca %p,arg %p),opt %p,"
"p %p,r %p\n",tp,handle,tca,arg,opt,p,r);
if (arg)
DPRINTK("*arg = 0x%lx\n",*arg);
if (!opt)
return 0;
if (rtattr_parse(tb,TCA_TCINDEX_MAX,RTA_DATA(opt),RTA_PAYLOAD(opt)) < 0)
return -EINVAL;
if (!tb[TCA_TCINDEX_HASH-1]) {
hash = p->hash;
} else {
if (RTA_PAYLOAD(tb[TCA_TCINDEX_HASH-1]) < sizeof(int))
return -EINVAL;
hash = *(int *) RTA_DATA(tb[TCA_TCINDEX_HASH-1]);
}
if (!tb[TCA_TCINDEX_MASK-1]) {
mask = p->mask;
} else {
if (RTA_PAYLOAD(tb[TCA_TCINDEX_MASK-1]) < sizeof(__u16))
return -EINVAL;
mask = *(__u16 *) RTA_DATA(tb[TCA_TCINDEX_MASK-1]);
}
if (!tb[TCA_TCINDEX_SHIFT-1])
shift = p->shift;
else {
if (RTA_PAYLOAD(tb[TCA_TCINDEX_SHIFT-1]) < sizeof(__u16))
return -EINVAL;
shift = *(int *) RTA_DATA(tb[TCA_TCINDEX_SHIFT-1]);
}
if (p->perfect && hash <= (mask >> shift))
return -EBUSY;
if (p->perfect && hash > p->alloc_hash)
return -EBUSY;
if (p->h && hash != p->alloc_hash)
return -EBUSY;
p->hash = hash;
p->mask = mask;
p->shift = shift;
if (tb[TCA_TCINDEX_FALL_THROUGH-1]) {
if (RTA_PAYLOAD(tb[TCA_TCINDEX_FALL_THROUGH-1]) < sizeof(int))
return -EINVAL;
p->fall_through =
*(int *) RTA_DATA(tb[TCA_TCINDEX_FALL_THROUGH-1]);
}
DPRINTK("classid/police %p/%p\n",tb[TCA_TCINDEX_CLASSID-1],
tb[TCA_TCINDEX_POLICE-1]);
if (!tb[TCA_TCINDEX_CLASSID-1] && !tb[TCA_TCINDEX_POLICE-1])
return 0;
if (!hash) {
if ((mask >> shift) < PERFECT_HASH_THRESHOLD) {
p->hash = (mask >> shift)+1;
} else {
p->hash = DEFAULT_HASH_SIZE;
}
}
if (!p->perfect && !p->h) {
p->alloc_hash = p->hash;
DPRINTK("hash %d mask %d\n",p->hash,p->mask);
if (p->hash > (mask >> shift)) {
p->perfect = kmalloc(p->hash*
sizeof(struct tcindex_filter_result),GFP_KERNEL);
if (!p->perfect)
return -ENOMEM;
memset(p->perfect, 0,
p->hash * sizeof(struct tcindex_filter_result));
} else {
p->h = kmalloc(p->hash*sizeof(struct tcindex_filter *),
GFP_KERNEL);
if (!p->h)
return -ENOMEM;
memset(p->h, 0, p->hash*sizeof(struct tcindex_filter *));
}
}
/*
* Note: this could be as restrictive as
* if (handle & ~(mask >> shift))
* but then, we'd fail handles that may become valid after some
* future mask change. While this is extremely unlikely to ever
* matter, the check below is safer (and also more
* backwards-compatible).
*/
if (p->perfect && handle >= p->alloc_hash)
return -EINVAL;
if (p->perfect) {
r = p->perfect+handle;
} else {
r = lookup(p,handle);
DPRINTK("r=%p\n",r);
if (!r)
r = &new_filter_result;
}
DPRINTK("r=%p\n",r);
if (tb[TCA_TCINDEX_CLASSID-1]) {
unsigned long cl = cls_set_class(tp,&r->res.class,0);
if (cl)
tp->q->ops->cl_ops->unbind_tcf(tp->q,cl);
r->res.classid = *(__u32 *) RTA_DATA(tb[TCA_TCINDEX_CLASSID-1]);
r->res.class = tp->q->ops->cl_ops->bind_tcf(tp->q,base,
r->res.classid);
if (!r->res.class) {
r->res.classid = 0;
return -ENOENT;
}
}
#ifdef CONFIG_NET_CLS_POLICE
{
struct tcf_police *police;
police = tb[TCA_TCINDEX_POLICE-1] ?
tcf_police_locate(tb[TCA_TCINDEX_POLICE-1],NULL) : NULL;
tcf_tree_lock(tp);
police = xchg(&r->police,police);
tcf_tree_unlock(tp);
tcf_police_release(police);
}
#endif
if (r != &new_filter_result)
return 0;
f = kmalloc(sizeof(struct tcindex_filter),GFP_KERNEL);
if (!f)
return -ENOMEM;
f->key = handle;
f->result = new_filter_result;
f->next = NULL;
for (walk = p->h+(handle % p->hash); *walk; walk = &(*walk)->next)
/* nothing */;
wmb();
*walk = f;
return 0;
}
static void tcindex_walk(struct tcf_proto *tp, struct tcf_walker *walker)
{
struct tcindex_data *p = PRIV(tp);
struct tcindex_filter *f,*next;
int i;
DPRINTK("tcindex_walk(tp %p,walker %p),p %p\n",tp,walker,p);
if (p->perfect) {
for (i = 0; i < p->hash; i++) {
if (!p->perfect[i].res.class)
continue;
if (walker->count >= walker->skip) {
if (walker->fn(tp,
(unsigned long) (p->perfect+i), walker)
< 0) {
walker->stop = 1;
return;
}
}
walker->count++;
}
}
if (!p->h)
return;
for (i = 0; i < p->hash; i++) {
for (f = p->h[i]; f; f = next) {
next = f->next;
if (walker->count >= walker->skip) {
if (walker->fn(tp,(unsigned long) &f->result,
walker) < 0) {
walker->stop = 1;
return;
}
}
walker->count++;
}
}
}
static int tcindex_destroy_element(struct tcf_proto *tp,
unsigned long arg, struct tcf_walker *walker)
{
return tcindex_delete(tp,arg);
}
static void tcindex_destroy(struct tcf_proto *tp)
{
struct tcindex_data *p = PRIV(tp);
struct tcf_walker walker;
DPRINTK("tcindex_destroy(tp %p),p %p\n",tp,p);
walker.count = 0;
walker.skip = 0;
walker.fn = &tcindex_destroy_element;
tcindex_walk(tp,&walker);
if (p->perfect)
kfree(p->perfect);
if (p->h)
kfree(p->h);
kfree(p);
tp->root = NULL;
MOD_DEC_USE_COUNT;
}
static int tcindex_dump(struct tcf_proto *tp, unsigned long fh,
struct sk_buff *skb, struct tcmsg *t)
{
struct tcindex_data *p = PRIV(tp);
struct tcindex_filter_result *r = (struct tcindex_filter_result *) fh;
unsigned char *b = skb->tail;
struct rtattr *rta;
DPRINTK("tcindex_dump(tp %p,fh 0x%lx,skb %p,t %p),p %p,r %p,b %p\n",
tp,fh,skb,t,p,r,b);
DPRINTK("p->perfect %p p->h %p\n",p->perfect,p->h);
rta = (struct rtattr *) b;
RTA_PUT(skb,TCA_OPTIONS,0,NULL);
if (!fh) {
t->tcm_handle = ~0; /* whatever ... */
RTA_PUT(skb,TCA_TCINDEX_HASH,sizeof(p->hash),&p->hash);
RTA_PUT(skb,TCA_TCINDEX_MASK,sizeof(p->mask),&p->mask);
RTA_PUT(skb,TCA_TCINDEX_SHIFT,sizeof(p->shift),&p->shift);
RTA_PUT(skb,TCA_TCINDEX_FALL_THROUGH,sizeof(p->fall_through),
&p->fall_through);
} else {
if (p->perfect) {
t->tcm_handle = r-p->perfect;
} else {
struct tcindex_filter *f;
int i;
t->tcm_handle = 0;
for (i = 0; !t->tcm_handle && i < p->hash; i++) {
for (f = p->h[i]; !t->tcm_handle && f;
f = f->next) {
if (&f->result == r)
t->tcm_handle = f->key;
}
}
}
DPRINTK("handle = %d\n",t->tcm_handle);
if (r->res.class)
RTA_PUT(skb, TCA_TCINDEX_CLASSID, 4, &r->res.classid);
#ifdef CONFIG_NET_CLS_POLICE
if (r->police) {
struct rtattr *p_rta = (struct rtattr *) skb->tail;
RTA_PUT(skb,TCA_TCINDEX_POLICE,0,NULL);
if (tcf_police_dump(skb,r->police) < 0)
goto rtattr_failure;
p_rta->rta_len = skb->tail-(u8 *) p_rta;
}
#endif
}
rta->rta_len = skb->tail-b;
return skb->len;
rtattr_failure:
skb_trim(skb, b - skb->data);
return -1;
}
struct tcf_proto_ops cls_tcindex_ops = {
NULL,
"tcindex",
tcindex_classify,
tcindex_init,
tcindex_destroy,
tcindex_get,
tcindex_put,
tcindex_change,
tcindex_delete,
tcindex_walk,
tcindex_dump
};
#ifdef MODULE
int init_module(void)
{
return register_tcf_proto_ops(&cls_tcindex_ops);
}
void cleanup_module(void)
{
unregister_tcf_proto_ops(&cls_tcindex_ops);
}
#endif
MODULE_LICENSE("GPL");
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