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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/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <net/act_api.h>
#include <net/netlink.h>
#include <net/pkt_cls.h>
/*
* 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 */
struct tcindex_filter_result {
struct tcf_exts exts;
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 inline int
tcindex_filter_is_set(struct tcindex_filter_result *r)
{
return tcf_exts_is_predicative(&r->exts) || r->res.classid;
}
static struct tcindex_filter_result *
tcindex_lookup(struct tcindex_data *p, u16 key)
{
struct tcindex_filter *f;
if (p->perfect)
return tcindex_filter_is_set(p->perfect + key) ?
p->perfect + key : NULL;
else if (p->h) {
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, const struct tcf_proto *tp,
struct tcf_result *res)
{
struct tcindex_data *p = tp->root;
struct tcindex_filter_result *f;
int key = (skb->tc_index & p->mask) >> p->shift;
pr_debug("tcindex_classify(skb %p,tp %p,res %p),p %p\n",
skb, tp, res, p);
f = tcindex_lookup(p, key);
if (!f) {
if (!p->fall_through)
return -1;
res->classid = TC_H_MAKE(TC_H_MAJ(tp->q->handle), key);
res->class = 0;
pr_debug("alg 0x%x\n", res->classid);
return 0;
}
*res = f->res;
pr_debug("map 0x%x\n", res->classid);
return tcf_exts_exec(skb, &f->exts, res);
}
static unsigned long tcindex_get(struct tcf_proto *tp, u32 handle)
{
struct tcindex_data *p = tp->root;
struct tcindex_filter_result *r;
pr_debug("tcindex_get(tp %p,handle 0x%08x)\n", tp, handle);
if (p->perfect && handle >= p->alloc_hash)
return 0;
r = tcindex_lookup(p, handle);
return r && tcindex_filter_is_set(r) ? (unsigned long) r : 0UL;
}
static void tcindex_put(struct tcf_proto *tp, unsigned long f)
{
pr_debug("tcindex_put(tp %p,f 0x%lx)\n", tp, f);
}
static int tcindex_init(struct tcf_proto *tp)
{
struct tcindex_data *p;
pr_debug("tcindex_init(tp %p)\n", tp);
p = kzalloc(sizeof(struct tcindex_data), GFP_KERNEL);
if (!p)
return -ENOMEM;
p->mask = 0xffff;
p->hash = DEFAULT_HASH_SIZE;
p->fall_through = 1;
tp->root = p;
return 0;
}
static int
__tcindex_delete(struct tcf_proto *tp, unsigned long arg, int lock)
{
struct tcindex_data *p = tp->root;
struct tcindex_filter_result *r = (struct tcindex_filter_result *) arg;
struct tcindex_filter *f = NULL;
pr_debug("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;
if (lock)
tcf_tree_lock(tp);
*walk = f->next;
if (lock)
tcf_tree_unlock(tp);
}
tcf_unbind_filter(tp, &r->res);
tcf_exts_destroy(tp, &r->exts);
kfree(f);
return 0;
}
static int tcindex_delete(struct tcf_proto *tp, unsigned long arg)
{
return __tcindex_delete(tp, arg, 1);
}
static inline int
valid_perfect_hash(struct tcindex_data *p)
{
return p->hash > (p->mask >> p->shift);
}
static const struct nla_policy tcindex_policy[TCA_TCINDEX_MAX + 1] = {
[TCA_TCINDEX_HASH] = { .type = NLA_U32 },
[TCA_TCINDEX_MASK] = { .type = NLA_U16 },
[TCA_TCINDEX_SHIFT] = { .type = NLA_U32 },
[TCA_TCINDEX_FALL_THROUGH] = { .type = NLA_U32 },
[TCA_TCINDEX_CLASSID] = { .type = NLA_U32 },
};
static int
tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base,
u32 handle, struct tcindex_data *p,
struct tcindex_filter_result *r, struct nlattr **tb,
struct nlattr *est)
{
int err, balloc = 0;
struct tcindex_filter_result new_filter_result, *old_r = r;
struct tcindex_filter_result cr;
struct tcindex_data cp;
struct tcindex_filter *f = NULL; /* make gcc behave */
struct tcf_exts e;
tcf_exts_init(&e, TCA_TCINDEX_ACT, TCA_TCINDEX_POLICE);
err = tcf_exts_validate(net, tp, tb, est, &e);
if (err < 0)
return err;
memcpy(&cp, p, sizeof(cp));
memset(&new_filter_result, 0, sizeof(new_filter_result));
tcf_exts_init(&new_filter_result.exts
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