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DEFINITIONS
This source file includes following definitions.
- tcindex_filter_is_set
- tcindex_lookup
- tcindex_classify
- tcindex_get
- tcindex_put
- tcindex_init
- __tcindex_delete
- tcindex_delete
- valid_perfect_hash
- tcindex_set_parms
- tcindex_change
- tcindex_walk
- tcindex_destroy_element
- tcindex_destroy
- tcindex_dump
- init_tcindex
- exit_tcindex
/*
* 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 <net/act_api.h>
#include <net/netlink.h>
#include <net/pkt_cls.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 */
#define PRIV(tp) ((struct tcindex_data *) (tp)->root)
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 const struct tcf_ext_map tcindex_ext_map = {
.police = TCA_TCINDEX_POLICE,
.action = TCA_TCINDEX_ACT
};
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, struct tcf_proto *tp,
struct tcf_result *res)
{
struct tcindex_data *p = PRIV(tp);
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 = PRIV(tp);
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 = PRIV(tp);
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 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;
err = tcf_exts_validate(tp, tb, est, &e, &tcindex_ext_map);
if (err < 0)
return err;
memcpy(&cp, p, sizeof(cp));
memset(&new_filter_result, 0, sizeof(new_filter_result));
if (old_r)
memcpy(&cr, r, sizeof(cr));
else
memset(&cr, 0, sizeof(cr));
if (tb[TCA_TCINDEX_HASH])
cp.hash = nla_get_u32(tb[TCA_TCINDEX_HASH]);
if (tb[TCA_TCINDEX_MASK])
cp.mask = nla_get_u16(tb[TCA_TCINDEX_MASK]);
if (tb[TCA_TCINDEX_SHIFT])
cp.shift = nla_get_u32(tb[TCA_TCINDEX_SHIFT]);
err = -EBUSY;
/* Hash already allocated, make sure that we still meet the
* requirements for the allocated hash.
*/
if (cp.perfect) {
if (!valid_perfect_hash(&cp) ||
cp.hash > cp.alloc_hash)
goto errout;
} else if (cp.h && cp.hash != cp.alloc_hash)
goto errout;
err = -EINVAL;
if (tb[TCA_TCINDEX_FALL_THROUGH])
cp.fall_through = nla_get_u32(tb[TCA_TCINDEX_FALL_THROUGH]);
if (!cp.hash) {
/* Hash not specified, use perfect hash if the upper limit
* of the hashing index is below the threshold.
*/
if ((cp.mask >> cp.shift) < PERFECT_HASH_THRESHOLD)
cp.hash = (cp.mask >> cp.shift)+1;
else
cp.hash = DEFAULT_HASH_SIZE;
}
if (!cp.perfect && !cp.h)
cp.alloc_hash = cp.hash;
/* 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 (cp.perfect || valid_perfect_hash(&cp))
if (handle >= cp.alloc_hash)
goto errout;
err = -ENOMEM;
if (!cp.perfect && !cp.h) {
if (valid_perfect_hash(&cp)) {
cp.perfect = kcalloc(cp.hash, sizeof(*r), GFP_KERNEL);
if (!cp.perfect)
goto errout;
balloc = 1;
} else {
cp.h = kcalloc(cp.hash, sizeof(f), GFP_KERNEL);
if (!cp.h)
goto errout;
balloc = 2;
}
}
if (cp.perfect)
r = cp.perfect + handle;
else
r = tcindex_lookup(&cp, handle) ? : &new_filter_result;
if (r == &new_filter_result) {
f = kzalloc(sizeof(*f), GFP_KERNEL);
if (!f)
goto errout_alloc;
}
if (tb[TCA_TCINDEX_CLASSID]) {
cr.res.classid = nla_get_u32(tb[TCA_TCINDEX_CLASSID]);
tcf_bind_filter(tp, &cr.res, base);
}
tcf_exts_change(tp, &cr.exts, &e);
tcf_tree_lock(tp);
if (old_r && old_r != r)
memset(old_r, 0, sizeof(*old_r));
memcpy(p, &cp, sizeof(cp));
memcpy(r, &cr, sizeof(cr));
if (r == &new_filter_result) {
struct tcindex_filter **fp;
f->key = handle;
f->result = new_filter_result;
f->next = NULL;
for (fp = p->h+(handle % p->hash); *fp; fp = &(*fp)->next)
/* nothing */;
*fp = f;
}
tcf_tree_unlock(tp);
return 0;
errout_alloc:
if (balloc == 1)
kfree(cp.perfect);
else if (balloc == 2)
kfree(cp.h);
errout:
tcf_exts_destroy(tp, &e);
return err;
}
static int
tcindex_change(struct tcf_proto *tp, unsigned long base, u32 handle,
struct nlattr **tca, unsigned long *arg)
{
struct nlattr *opt = tca[TCA_OPTIONS];
struct nlattr *tb[TCA_TCINDEX_MAX + 1];
struct tcindex_data *p = PRIV(tp);
struct tcindex_filter_result *r = (struct tcindex_filter_result *) *arg;
int err;
pr_debug("tcindex_change(tp %p,handle 0x%08x,tca %p,arg %p),opt %p,"
"p %p,r %p,*arg 0x%lx\n",
tp, handle, tca, arg, opt, p, r, arg ? *arg : 0L);
if (!opt)
return 0;
err = nla_parse_nested(tb, TCA_TCINDEX_MAX, opt, tcindex_policy);
if (err < 0)
return err;
return tcindex_set_parms(tp, base, handle, p, r, tb, tca[TCA_RATE]);
}
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;
pr_debug("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, 0);
}
static void tcindex_destroy(struct tcf_proto *tp)
{
struct tcindex_data *p = PRIV(tp);
struct tcf_walker walker;
pr_debug("tcindex_destroy(tp %p),p %p\n", tp, p);
walker.count = 0;
walker.skip = 0;
walker.fn = &tcindex_destroy_element;
tcindex_walk(tp, &walker);
kfree(p->perfect);
kfree(p->h);
kfree(p);
tp->root = NULL;
}
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_pointer(skb);
struct nlattr *nest;
pr_debug("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);
pr_debug("p->perfect %p p->h %p\n", p->perfect, p->h);
nest = nla_nest_start(skb, TCA_OPTIONS);
if (nest == NULL)
goto nla_put_failure;
if (!fh) {
t->tcm_handle = ~0; /* whatever ... */
NLA_PUT_U32(skb, TCA_TCINDEX_HASH, p->hash);
NLA_PUT_U16(skb, TCA_TCINDEX_MASK, p->mask);
NLA_PUT_U32(skb, TCA_TCINDEX_SHIFT, p->shift);
NLA_PUT_U32(skb, TCA_TCINDEX_FALL_THROUGH, p->fall_through);
nla_nest_end(skb, nest);
} 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;
}
}
}
pr_debug("handle = %d\n", t->tcm_handle);
if (r->res.class)
NLA_PUT_U32(skb, TCA_TCINDEX_CLASSID, r->res.classid);
if (tcf_exts_dump(skb, &r->exts, &tcindex_ext_map) < 0)
goto nla_put_failure;
nla_nest_end(skb, nest);
if (tcf_exts_dump_stats(skb, &r->exts, &tcindex_ext_map) < 0)
goto nla_put_failure;
}
return skb->len;
nla_put_failure:
nlmsg_trim(skb, b);
return -1;
}
static struct tcf_proto_ops cls_tcindex_ops __read_mostly = {
.kind = "tcindex",
.classify = tcindex_classify,
.init = tcindex_init,
.destroy = tcindex_destroy,
.get = tcindex_get,
.put = tcindex_put,
.change = tcindex_change,
.delete = tcindex_delete,
.walk = tcindex_walk,
.dump = tcindex_dump,
.owner = THIS_MODULE,
};
static int __init init_tcindex(void)
{
return register_tcf_proto_ops(&cls_tcindex_ops);
}
static void __exit exit_tcindex(void)
{
unregister_tcf_proto_ops(&cls_tcindex_ops);
}
module_init(init_tcindex)
module_exit(exit_tcindex)
MODULE_LICENSE("GPL");