2 * net/sched/cls_tcindex.c Packet classifier for skb->tc_index
4 * Written 1998,1999 by Werner Almesberger, EPFL ICA
7 #include <linux/module.h>
8 #include <linux/types.h>
9 #include <linux/kernel.h>
10 #include <linux/skbuff.h>
11 #include <linux/errno.h>
12 #include <linux/slab.h>
13 #include <net/act_api.h>
14 #include <net/netlink.h>
15 #include <net/pkt_cls.h>
16 #include <net/sch_generic.h>
19 * Passing parameters to the root seems to be done more awkwardly than really
20 * necessary. At least, u32 doesn't seem to use such dirty hacks. To be
24 #define PERFECT_HASH_THRESHOLD 64 /* use perfect hash if not bigger */
25 #define DEFAULT_HASH_SIZE 64 /* optimized for diffserv */
28 struct tcindex_filter_result
{
30 struct tcf_result res
;
31 struct rcu_work rwork
;
34 struct tcindex_filter
{
36 struct tcindex_filter_result result
;
37 struct tcindex_filter __rcu
*next
;
38 struct rcu_work rwork
;
43 struct tcindex_filter_result
*perfect
; /* perfect hash; NULL if none */
44 struct tcindex_filter __rcu
**h
; /* imperfect hash; */
46 u16 mask
; /* AND key with mask */
47 u32 shift
; /* shift ANDed key to the right */
48 u32 hash
; /* hash table size; 0 if undefined */
49 u32 alloc_hash
; /* allocated size */
50 u32 fall_through
; /* 0: only classify if explicit match */
51 struct rcu_work rwork
;
54 static inline int tcindex_filter_is_set(struct tcindex_filter_result
*r
)
56 return tcf_exts_has_actions(&r
->exts
) || r
->res
.classid
;
59 static struct tcindex_filter_result
*tcindex_lookup(struct tcindex_data
*p
,
63 struct tcindex_filter_result
*f
= p
->perfect
+ key
;
65 return tcindex_filter_is_set(f
) ? f
: NULL
;
67 struct tcindex_filter __rcu
**fp
;
68 struct tcindex_filter
*f
;
70 fp
= &p
->h
[key
% p
->hash
];
71 for (f
= rcu_dereference_bh_rtnl(*fp
);
73 fp
= &f
->next
, f
= rcu_dereference_bh_rtnl(*fp
))
82 static int tcindex_classify(struct sk_buff
*skb
, const struct tcf_proto
*tp
,
83 struct tcf_result
*res
)
85 struct tcindex_data
*p
= rcu_dereference_bh(tp
->root
);
86 struct tcindex_filter_result
*f
;
87 int key
= (skb
->tc_index
& p
->mask
) >> p
->shift
;
89 pr_debug("tcindex_classify(skb %p,tp %p,res %p),p %p\n",
92 f
= tcindex_lookup(p
, key
);
94 struct Qdisc
*q
= tcf_block_q(tp
->chain
->block
);
98 res
->classid
= TC_H_MAKE(TC_H_MAJ(q
->handle
), key
);
100 pr_debug("alg 0x%x\n", res
->classid
);
104 pr_debug("map 0x%x\n", res
->classid
);
106 return tcf_exts_exec(skb
, &f
->exts
, res
);
110 static void *tcindex_get(struct tcf_proto
*tp
, u32 handle
)
112 struct tcindex_data
*p
= rtnl_dereference(tp
->root
);
113 struct tcindex_filter_result
*r
;
115 pr_debug("tcindex_get(tp %p,handle 0x%08x)\n", tp
, handle
);
116 if (p
->perfect
&& handle
>= p
->alloc_hash
)
118 r
= tcindex_lookup(p
, handle
);
119 return r
&& tcindex_filter_is_set(r
) ? r
: NULL
;
122 static int tcindex_init(struct tcf_proto
*tp
)
124 struct tcindex_data
*p
;
126 pr_debug("tcindex_init(tp %p)\n", tp
);
127 p
= kzalloc(sizeof(struct tcindex_data
), GFP_KERNEL
);
132 p
->hash
= DEFAULT_HASH_SIZE
;
135 rcu_assign_pointer(tp
->root
, p
);
139 static void __tcindex_destroy_rexts(struct tcindex_filter_result
*r
)
141 tcf_exts_destroy(&r
->exts
);
142 tcf_exts_put_net(&r
->exts
);
145 static void tcindex_destroy_rexts_work(struct work_struct
*work
)
147 struct tcindex_filter_result
*r
;
149 r
= container_of(to_rcu_work(work
),
150 struct tcindex_filter_result
,
153 __tcindex_destroy_rexts(r
);
157 static void __tcindex_destroy_fexts(struct tcindex_filter
*f
)
159 tcf_exts_destroy(&f
->result
.exts
);
160 tcf_exts_put_net(&f
->result
.exts
);
164 static void tcindex_destroy_fexts_work(struct work_struct
*work
)
166 struct tcindex_filter
*f
= container_of(to_rcu_work(work
),
167 struct tcindex_filter
,
171 __tcindex_destroy_fexts(f
);
175 static int tcindex_delete(struct tcf_proto
*tp
, void *arg
, bool *last
)
177 struct tcindex_data
*p
= rtnl_dereference(tp
->root
);
178 struct tcindex_filter_result
*r
= arg
;
179 struct tcindex_filter __rcu
**walk
;
180 struct tcindex_filter
*f
= NULL
;
182 pr_debug("tcindex_delete(tp %p,arg %p),p %p\n", tp
, arg
, p
);
189 for (i
= 0; i
< p
->hash
; i
++) {
191 for (f
= rtnl_dereference(*walk
); f
;
192 walk
= &f
->next
, f
= rtnl_dereference(*walk
)) {
200 rcu_assign_pointer(*walk
, rtnl_dereference(f
->next
));
202 tcf_unbind_filter(tp
, &r
->res
);
203 /* all classifiers are required to call tcf_exts_destroy() after rcu
204 * grace period, since converted-to-rcu actions are relying on that
205 * in cleanup() callback
208 if (tcf_exts_get_net(&f
->result
.exts
))
209 tcf_queue_work(&f
->rwork
, tcindex_destroy_fexts_work
);
211 __tcindex_destroy_fexts(f
);
213 if (tcf_exts_get_net(&r
->exts
))
214 tcf_queue_work(&r
->rwork
, tcindex_destroy_rexts_work
);
216 __tcindex_destroy_rexts(r
);
223 static void tcindex_destroy_work(struct work_struct
*work
)
225 struct tcindex_data
*p
= container_of(to_rcu_work(work
),
235 valid_perfect_hash(struct tcindex_data
*p
)
237 return p
->hash
> (p
->mask
>> p
->shift
);
240 static const struct nla_policy tcindex_policy
[TCA_TCINDEX_MAX
+ 1] = {
241 [TCA_TCINDEX_HASH
] = { .type
= NLA_U32
},
242 [TCA_TCINDEX_MASK
] = { .type
= NLA_U16
},
243 [TCA_TCINDEX_SHIFT
] = { .type
= NLA_U32
},
244 [TCA_TCINDEX_FALL_THROUGH
] = { .type
= NLA_U32
},
245 [TCA_TCINDEX_CLASSID
] = { .type
= NLA_U32
},
248 static int tcindex_filter_result_init(struct tcindex_filter_result
*r
,
251 memset(r
, 0, sizeof(*r
));
252 return tcf_exts_init(&r
->exts
, net
, TCA_TCINDEX_ACT
,
256 static void tcindex_partial_destroy_work(struct work_struct
*work
)
258 struct tcindex_data
*p
= container_of(to_rcu_work(work
),
266 static void tcindex_free_perfect_hash(struct tcindex_data
*cp
)
270 for (i
= 0; i
< cp
->hash
; i
++)
271 tcf_exts_destroy(&cp
->perfect
[i
].exts
);
275 static int tcindex_alloc_perfect_hash(struct net
*net
, struct tcindex_data
*cp
)
279 cp
->perfect
= kcalloc(cp
->hash
, sizeof(struct tcindex_filter_result
),
284 for (i
= 0; i
< cp
->hash
; i
++) {
285 err
= tcf_exts_init(&cp
->perfect
[i
].exts
, net
,
286 TCA_TCINDEX_ACT
, TCA_TCINDEX_POLICE
);
294 tcindex_free_perfect_hash(cp
);
299 tcindex_set_parms(struct net
*net
, struct tcf_proto
*tp
, unsigned long base
,
300 u32 handle
, struct tcindex_data
*p
,
301 struct tcindex_filter_result
*r
, struct nlattr
**tb
,
302 struct nlattr
*est
, bool ovr
)
304 struct tcindex_filter_result new_filter_result
, *old_r
= r
;
305 struct tcindex_filter_result cr
;
306 struct tcindex_data
*cp
= NULL
, *oldp
;
307 struct tcindex_filter
*f
= NULL
; /* make gcc behave */
311 err
= tcf_exts_init(&e
, net
, TCA_TCINDEX_ACT
, TCA_TCINDEX_POLICE
);
314 err
= tcf_exts_validate(net
, tp
, tb
, est
, &e
, ovr
);
319 /* tcindex_data attributes must look atomic to classifier/lookup so
320 * allocate new tcindex data and RCU assign it onto root. Keeping
321 * perfect hash and hash pointers from old data.
323 cp
= kzalloc(sizeof(*cp
), GFP_KERNEL
);
328 cp
->shift
= p
->shift
;
330 cp
->alloc_hash
= p
->alloc_hash
;
331 cp
->fall_through
= p
->fall_through
;
337 if (tcindex_alloc_perfect_hash(net
, cp
) < 0)
339 for (i
= 0; i
< cp
->hash
; i
++)
340 cp
->perfect
[i
].res
= p
->perfect
[i
].res
;
345 err
= tcindex_filter_result_init(&new_filter_result
, net
);
348 err
= tcindex_filter_result_init(&cr
);
354 if (tb
[TCA_TCINDEX_HASH
])
355 cp
->hash
= nla_get_u32(tb
[TCA_TCINDEX_HASH
]);
357 if (tb
[TCA_TCINDEX_MASK
])
358 cp
->mask
= nla_get_u16(tb
[TCA_TCINDEX_MASK
]);
360 if (tb
[TCA_TCINDEX_SHIFT
])
361 cp
->shift
= nla_get_u32(tb
[TCA_TCINDEX_SHIFT
]);
365 /* Hash already allocated, make sure that we still meet the
366 * requirements for the allocated hash.
369 if (!valid_perfect_hash(cp
) ||
370 cp
->hash
> cp
->alloc_hash
)
372 } else if (cp
->h
&& cp
->hash
!= cp
->alloc_hash
) {
377 if (tb
[TCA_TCINDEX_FALL_THROUGH
])
378 cp
->fall_through
= nla_get_u32(tb
[TCA_TCINDEX_FALL_THROUGH
]);
381 /* Hash not specified, use perfect hash if the upper limit
382 * of the hashing index is below the threshold.
384 if ((cp
->mask
>> cp
->shift
) < PERFECT_HASH_THRESHOLD
)
385 cp
->hash
= (cp
->mask
>> cp
->shift
) + 1;
387 cp
->hash
= DEFAULT_HASH_SIZE
;
390 if (!cp
->perfect
&& !cp
->h
)
391 cp
->alloc_hash
= cp
->hash
;
393 /* Note: this could be as restrictive as if (handle & ~(mask >> shift))
394 * but then, we'd fail handles that may become valid after some future
395 * mask change. While this is extremely unlikely to ever matter,
396 * the check below is safer (and also more backwards-compatible).
398 if (cp
->perfect
|| valid_perfect_hash(cp
))
399 if (handle
>= cp
->alloc_hash
)
404 if (!cp
->perfect
&& !cp
->h
) {
405 if (valid_perfect_hash(cp
)) {
406 if (tcindex_alloc_perfect_hash(net
, cp
) < 0)
410 struct tcindex_filter __rcu
**hash
;
412 hash
= kcalloc(cp
->hash
,
413 sizeof(struct tcindex_filter
*),
425 r
= cp
->perfect
+ handle
;
427 r
= tcindex_lookup(cp
, handle
) ? : &new_filter_result
;
429 if (r
== &new_filter_result
) {
430 f
= kzalloc(sizeof(*f
), GFP_KERNEL
);
435 err
= tcindex_filter_result_init(&f
->result
, net
);
442 if (tb
[TCA_TCINDEX_CLASSID
]) {
443 cr
.res
.classid
= nla_get_u32(tb
[TCA_TCINDEX_CLASSID
]);
444 tcf_bind_filter(tp
, &cr
.res
, base
);
447 if (old_r
&& old_r
!= r
) {
448 err
= tcindex_filter_result_init(old_r
, net
);
457 tcf_exts_change(&r
->exts
, &e
);
459 rcu_assign_pointer(tp
->root
, cp
);
461 if (r
== &new_filter_result
) {
462 struct tcindex_filter
*nfp
;
463 struct tcindex_filter __rcu
**fp
;
465 tcf_exts_change(&f
->result
.exts
, &r
->exts
);
467 fp
= cp
->h
+ (handle
% cp
->hash
);
468 for (nfp
= rtnl_dereference(*fp
);
470 fp
= &nfp
->next
, nfp
= rtnl_dereference(*fp
))
473 rcu_assign_pointer(*fp
, f
);
477 tcf_queue_work(&oldp
->rwork
, tcindex_partial_destroy_work
);
482 tcindex_free_perfect_hash(cp
);
483 else if (balloc
== 2)
486 tcf_exts_destroy(&cr
.exts
);
487 tcf_exts_destroy(&new_filter_result
.exts
);
490 tcf_exts_destroy(&e
);
495 tcindex_change(struct net
*net
, struct sk_buff
*in_skb
,
496 struct tcf_proto
*tp
, unsigned long base
, u32 handle
,
497 struct nlattr
**tca
, void **arg
, bool ovr
)
499 struct nlattr
*opt
= tca
[TCA_OPTIONS
];
500 struct nlattr
*tb
[TCA_TCINDEX_MAX
+ 1];
501 struct tcindex_data
*p
= rtnl_dereference(tp
->root
);
502 struct tcindex_filter_result
*r
= *arg
;
505 pr_debug("tcindex_change(tp %p,handle 0x%08x,tca %p,arg %p),opt %p,"
506 "p %p,r %p,*arg %p\n",
507 tp
, handle
, tca
, arg
, opt
, p
, r
, arg
? *arg
: NULL
);
512 err
= nla_parse_nested(tb
, TCA_TCINDEX_MAX
, opt
, tcindex_policy
, NULL
);
516 return tcindex_set_parms(net
, tp
, base
, handle
, p
, r
, tb
,
520 static void tcindex_walk(struct tcf_proto
*tp
, struct tcf_walker
*walker
)
522 struct tcindex_data
*p
= rtnl_dereference(tp
->root
);
523 struct tcindex_filter
*f
, *next
;
526 pr_debug("tcindex_walk(tp %p,walker %p),p %p\n", tp
, walker
, p
);
528 for (i
= 0; i
< p
->hash
; i
++) {
529 if (!p
->perfect
[i
].res
.class)
531 if (walker
->count
>= walker
->skip
) {
532 if (walker
->fn(tp
, p
->perfect
+ i
, walker
) < 0) {
542 for (i
= 0; i
< p
->hash
; i
++) {
543 for (f
= rtnl_dereference(p
->h
[i
]); f
; f
= next
) {
544 next
= rtnl_dereference(f
->next
);
545 if (walker
->count
>= walker
->skip
) {
546 if (walker
->fn(tp
, &f
->result
, walker
) < 0) {
556 static void tcindex_destroy(struct tcf_proto
*tp
)
558 struct tcindex_data
*p
= rtnl_dereference(tp
->root
);
561 pr_debug("tcindex_destroy(tp %p),p %p\n", tp
, p
);
564 for (i
= 0; i
< p
->hash
; i
++) {
565 struct tcindex_filter_result
*r
= p
->perfect
+ i
;
567 tcf_unbind_filter(tp
, &r
->res
);
568 if (tcf_exts_get_net(&r
->exts
))
569 tcf_queue_work(&r
->rwork
,
570 tcindex_destroy_rexts_work
);
572 __tcindex_destroy_rexts(r
);
576 for (i
= 0; p
->h
&& i
< p
->hash
; i
++) {
577 struct tcindex_filter
*f
, *next
;
580 for (f
= rtnl_dereference(p
->h
[i
]); f
; f
= next
) {
581 next
= rtnl_dereference(f
->next
);
582 tcindex_delete(tp
, &f
->result
, &last
);
586 tcf_queue_work(&p
->rwork
, tcindex_destroy_work
);
590 static int tcindex_dump(struct net
*net
, struct tcf_proto
*tp
, void *fh
,
591 struct sk_buff
*skb
, struct tcmsg
*t
)
593 struct tcindex_data
*p
= rtnl_dereference(tp
->root
);
594 struct tcindex_filter_result
*r
= fh
;
597 pr_debug("tcindex_dump(tp %p,fh %p,skb %p,t %p),p %p,r %p\n",
598 tp
, fh
, skb
, t
, p
, r
);
599 pr_debug("p->perfect %p p->h %p\n", p
->perfect
, p
->h
);
601 nest
= nla_nest_start(skb
, TCA_OPTIONS
);
603 goto nla_put_failure
;
606 t
->tcm_handle
= ~0; /* whatever ... */
607 if (nla_put_u32(skb
, TCA_TCINDEX_HASH
, p
->hash
) ||
608 nla_put_u16(skb
, TCA_TCINDEX_MASK
, p
->mask
) ||
609 nla_put_u32(skb
, TCA_TCINDEX_SHIFT
, p
->shift
) ||
610 nla_put_u32(skb
, TCA_TCINDEX_FALL_THROUGH
, p
->fall_through
))
611 goto nla_put_failure
;
612 nla_nest_end(skb
, nest
);
615 t
->tcm_handle
= r
- p
->perfect
;
617 struct tcindex_filter
*f
;
618 struct tcindex_filter __rcu
**fp
;
622 for (i
= 0; !t
->tcm_handle
&& i
< p
->hash
; i
++) {
624 for (f
= rtnl_dereference(*fp
);
626 fp
= &f
->next
, f
= rtnl_dereference(*fp
)) {
628 t
->tcm_handle
= f
->key
;
632 pr_debug("handle = %d\n", t
->tcm_handle
);
634 nla_put_u32(skb
, TCA_TCINDEX_CLASSID
, r
->res
.classid
))
635 goto nla_put_failure
;
637 if (tcf_exts_dump(skb
, &r
->exts
) < 0)
638 goto nla_put_failure
;
639 nla_nest_end(skb
, nest
);
641 if (tcf_exts_dump_stats(skb
, &r
->exts
) < 0)
642 goto nla_put_failure
;
648 nla_nest_cancel(skb
, nest
);
652 static void tcindex_bind_class(void *fh
, u32 classid
, unsigned long cl
)
654 struct tcindex_filter_result
*r
= fh
;
656 if (r
&& r
->res
.classid
== classid
)
660 static struct tcf_proto_ops cls_tcindex_ops __read_mostly
= {
662 .classify
= tcindex_classify
,
663 .init
= tcindex_init
,
664 .destroy
= tcindex_destroy
,
666 .change
= tcindex_change
,
667 .delete = tcindex_delete
,
668 .walk
= tcindex_walk
,
669 .dump
= tcindex_dump
,
670 .bind_class
= tcindex_bind_class
,
671 .owner
= THIS_MODULE
,
674 static int __init
init_tcindex(void)
676 return register_tcf_proto_ops(&cls_tcindex_ops
);
679 static void __exit
exit_tcindex(void)
681 unregister_tcf_proto_ops(&cls_tcindex_ops
);
684 module_init(init_tcindex
)
685 module_exit(exit_tcindex
)
686 MODULE_LICENSE("GPL");