Linux 커 널 의 데이터 제어 (20)
16608 단어 링크 ux 전재
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7.11 tcindex
tcindex skb tcindex , tcindex , net/sched/cls_tcindex.c 。
7.11.1
// tcindex
struct tcindex_filter_result {
//
struct tcf_exts exts;
//
struct tcf_result res;
};
// tcindex
struct tcindex_filter {
//
u16 key;
//
struct tcindex_filter_result result;
//
struct tcindex_filter *next;
};
// tcindex
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 tcf_ext_map tcindex_ext_map = {
.police = TCA_TCINDEX_POLICE,
.action = TCA_TCINDEX_ACT
};
//
static struct tcf_proto_ops cls_tcindex_ops = {
.next = NULL,
.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,
};
7.11.2
static int tcindex_init(struct tcf_proto *tp)
{
struct tcindex_data *p;
DPRINTK("tcindex_init(tp %p)
",tp);
// tcindex
p = kzalloc(sizeof(struct tcindex_data),GFP_KERNEL);
if (!p)
return -ENOMEM;
//
p->mask = 0xffff;
p->hash = DEFAULT_HASH_SIZE; // 64
p->fall_through = 1;
// TCF_PROTO
tp->root = p;
return 0;
}
7.11.3
#define PRIV(tp) ((struct tcindex_data *) (tp)->root)
static int tcindex_classify(struct sk_buff *skb, struct tcf_proto *tp,
struct tcf_result *res)
{
// TCF_PROTO tcindex
struct tcindex_data *p = PRIV(tp);
struct tcindex_filter_result *f;
// tcindex key: ,
int key = (skb->tc_index & p->mask) >> p->shift;
D2PRINTK("tcindex_classify(skb %p,tp %p,res %p),p %p
",skb,tp,res,p);
// key
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;
D2PRINTK("alg 0x%x
",res->classid);
return 0;
}
// ,
*res = f->res;
D2PRINTK("map 0x%x
",res->classid);
// TCF
return tcf_exts_exec(skb, &f->exts, res);
}
// key
static struct tcindex_filter_result *
tcindex_lookup(struct tcindex_data *p, u16 key)
{
struct tcindex_filter *f;
if (p->perfect)
// perfect key
return tcindex_filter_is_set(p->perfect + key) ?
p->perfect + key : NULL;
else if (p->h) {
// perfect
for (f = p->h[key % p->hash]; f; f = f->next)
if (f->key == key)
return &f->result;
}
return NULL;
}
7.11.4
static void tcindex_destroy(struct tcf_proto *tp)
{
// TCF_PROTO tcindex
struct tcindex_data *p = PRIV(tp);
struct tcf_walker walker;
DPRINTK("tcindex_destroy(tp %p),p %p
",tp,p);
//
walker.count = 0;
walker.skip = 0;
//
walker.fn = &tcindex_destroy_element;
// tcindex
tcindex_walk(tp,&walker);
// perfect
kfree(p->perfect);
// perfect
kfree(p->h);
// tcindex
kfree(p);
tp->root = NULL;
}
static int tcindex_destroy_element(struct tcf_proto *tp,
unsigned long arg, struct tcf_walker *walker)
{
// tcindex ,
return __tcindex_delete(tp, arg, 0);
}
static int
__tcindex_delete(struct tcf_proto *tp, unsigned long arg, int lock)
{
// TCF_PROTO tcindex
struct tcindex_data *p = PRIV(tp);
//
struct tcindex_filter_result *r = (struct tcindex_filter_result *) arg;
struct tcindex_filter *f = NULL;
DPRINTK("tcindex_delete(tp %p,arg 0x%lx),p %p,f %p
",tp,arg,p,f);
if (p->perfect) {
// perfect , r perfect
// ,
if (!r->res.class)
return -ENOENT;
} else {
// r perfect ,
int i;
struct tcindex_filter **walk = NULL;
// HASH
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
tcf_exts_destroy(tp, &r->exts);
// , perfect , perfect
kfree(f);
return 0;
}
7.11.5
// handle tcindex
static unsigned long tcindex_get(struct tcf_proto *tp, u32 handle)
{
// TCF_PROTO tcindex
struct tcindex_data *p = PRIV(tp);
struct tcindex_filter_result *r;
DPRINTK("tcindex_get(tp %p,handle 0x%08x)
",tp,handle);
// perfect , handle ,
if (p->perfect && handle >= p->alloc_hash)
return 0;
// handle
r = tcindex_lookup(p, handle);
return r && tcindex_filter_is_set(r) ? (unsigned long) r : 0UL;
}
7.11.6
//
static void tcindex_put(struct tcf_proto *tp, unsigned long f)
{
DPRINTK("tcindex_put(tp %p,f 0x%lx)
",tp,f);
}
7.11.7
// tc filter
static int
tcindex_change(struct tcf_proto *tp, unsigned long base, u32 handle,
struct rtattr **tca, unsigned long *arg)
{
//
struct rtattr *opt = tca[TCA_OPTIONS-1];
struct rtattr *tb[TCA_TCINDEX_MAX];
// TCF_PROTO tcindex
struct tcindex_data *p = PRIV(tp);
//
struct tcindex_filter_result *r = (struct tcindex_filter_result *) *arg;
DPRINTK("tcindex_change(tp %p,handle 0x%08x,tca %p,arg %p),opt %p,"
"p %p,r %p,*arg 0x%lx
",
tp, handle, tca, arg, opt, p, r, arg ? *arg : 0L);
// ,
if (!opt)
return 0;
//
if (rtattr_parse_nested(tb, TCA_TCINDEX_MAX, opt) < 0)
return -EINVAL;
// tcindex
return tcindex_set_parms(tp, base, handle, p, r, tb, tca[TCA_RATE-1]);
}
static int
tcindex_set_parms(struct tcf_proto *tp, unsigned long base, u32 handle,
struct tcindex_data *p, struct tcindex_filter_result *r,
struct rtattr **tb, struct rtattr *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
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));
err = -EINVAL;
// tcindex HASH
if (tb[TCA_TCINDEX_HASH-1]) {
if (RTA_PAYLOAD(tb[TCA_TCINDEX_HASH-1]) < sizeof(u32))
goto errout;
cp.hash = *(u32 *) RTA_DATA(tb[TCA_TCINDEX_HASH-1]);
}
// tcindex
if (tb[TCA_TCINDEX_MASK-1]) {
if (RTA_PAYLOAD(tb[TCA_TCINDEX_MASK-1]) < sizeof(u16))
goto errout;
cp.mask = *(u16 *) RTA_DATA(tb[TCA_TCINDEX_MASK-1]);
}
//
if (tb[TCA_TCINDEX_SHIFT-1]) {
if (RTA_PAYLOAD(tb[TCA_TCINDEX_SHIFT-1]) < sizeof(u16))
goto errout;
cp.shift = *(u16 *) RTA_DATA(tb[TCA_TCINDEX_SHIFT-1]);
}
err = -EBUSY;
/* Hash already allocated, make sure that we still meet the
* requirements for the allocated hash.
*/
if (cp.perfect) {
// perfect ,
if (!valid_perfect_hash(&cp) ||
cp.hash > cp.alloc_hash)
goto errout;
} else
// perfect ,
if (cp.h && cp.hash != cp.alloc_hash)
goto errout;
err = -EINVAL;
// fall_through
if (tb[TCA_TCINDEX_FALL_THROUGH-1]) {
if (RTA_PAYLOAD(tb[TCA_TCINDEX_FALL_THROUGH-1]) < sizeof(u32))
goto errout;
cp.fall_through =
*(u32 *) RTA_DATA(tb[TCA_TCINDEX_FALL_THROUGH-1]);
}
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;
}
// perfect perfect , , alloc_hash
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).
*/
// handle
if (cp.perfect || valid_perfect_hash(&cp))
if (handle >= cp.alloc_hash)
goto errout;
err = -ENOMEM;
if (!cp.perfect && !cp.h) {
// perfect perfect
if (valid_perfect_hash(&cp)) {
// hash perfect
cp.perfect = kcalloc(cp.hash, sizeof(*r), GFP_KERNEL);
if (!cp.perfect)
goto errout;
// perfect
balloc = 1;
} else {
// perfect , hash
// sizeof(f) , 32 4
cp.h = kcalloc(cp.hash, sizeof(f), GFP_KERNEL);
if (!cp.h)
goto errout;
// perfect
balloc = 2;
}
}
// handle
if (cp.perfect)
r = cp.perfect + handle;
else
r = tcindex_lookup(&cp, handle) ? : &new_filter_result;
if (r == &new_filter_result) {
// r perfect
// tcindex
f = kzalloc(sizeof(*f), GFP_KERNEL);
if (!f)
goto errout_alloc;
}
// ID
if (tb[TCA_TCINDEX_CLASSID-1]) {
// ID
cr.res.classid = *(u32 *) RTA_DATA(tb[TCA_TCINDEX_CLASSID-1]);
//
tcf_bind_filter(tp, &cr.res, base);
}
// TCF
tcf_exts_change(tp, &cr.exts, &e);
tcf_tree_lock(tp);
// ,
if (old_r && old_r != r)
memset(old_r, 0, sizeof(*old_r));
// tcindex ,
// p perfect
memcpy(p, &cp, sizeof(cp));
memcpy(r, &cr, sizeof(cr));
if (r == &new_filter_result) {
// pefect
struct tcindex_filter **fp;
// tcindex
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;
}
7.11.8
// __tcindex_delete ,
static int tcindex_delete(struct tcf_proto *tp, unsigned long arg)
{
// 1,
return __tcindex_delete(tp, arg, 1);
}
7.11.9
static void tcindex_walk(struct tcf_proto *tp, struct tcf_walker *walker)
{
// TCF_PROTO tcindex
struct tcindex_data *p = PRIV(tp);
struct tcindex_filter *f,*next;
int i;
DPRINTK("tcindex_walk(tp %p,walker %p),p %p
",tp,walker,p);
if (p->perfect) {
// 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++;
}
}
// perfect ,
if (!p->h)
return;
// perfect
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++;
}
}
}
7.11.10
static int tcindex_dump(struct tcf_proto *tp, unsigned long fh,
struct sk_buff *skb, struct tcmsg *t)
{
// TCF_PROTO tcindex
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
",
tp,fh,skb,t,p,r,b);
DPRINTK("p->perfect %p p->h %p
",p->perfect,p->h);
// netlink
rta = (struct rtattr *) b;
RTA_PUT(skb,TCA_OPTIONS,0,NULL);
if (!fh) {
// handle 0
// handle 1
t->tcm_handle = ~0; /* whatever ... */
// tcindex
//
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);
// fall_through
RTA_PUT(skb,TCA_TCINDEX_FALL_THROUGH,sizeof(p->fall_through),
&p->fall_through);
rta->rta_len = skb->tail-b;
} else {
if (p->perfect) {
// perfect
// handle r perfect
t->tcm_handle = r-p->perfect;
} else {
// perfect
struct tcindex_filter *f;
int i;
t->tcm_handle = 0;
// perfect , result r , key handle
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
",t->tcm_handle);
//
if (r->res.class)
RTA_PUT(skb, TCA_TCINDEX_CLASSID, 4, &r->res.classid);
// TCF
if (tcf_exts_dump(skb, &r->exts, &tcindex_ext_map) < 0)
goto rtattr_failure;
//
rta->rta_len = skb->tail-b;
// TCF
if (tcf_exts_dump_stats(skb, &r->exts, &tcindex_ext_map) < 0)
goto rtattr_failure;
}
return skb->len;
rtattr_failure:
skb_trim(skb, b - skb->data);
return -1;
}
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