]> bbs.cooldavid.org Git - net-next-2.6.git/blame - net/sched/cls_tcindex.c
xps: Transmit Packet Steering
[net-next-2.6.git] / net / sched / cls_tcindex.c
CommitLineData
1da177e4
LT
1/*
2 * net/sched/cls_tcindex.c Packet classifier for skb->tc_index
3 *
4 * Written 1998,1999 by Werner Almesberger, EPFL ICA
5 */
6
1da177e4
LT
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>
5a0e3ad6 12#include <linux/slab.h>
1da177e4 13#include <net/act_api.h>
dc5fc579 14#include <net/netlink.h>
1da177e4 15#include <net/pkt_cls.h>
1da177e4 16
1da177e4
LT
17/*
18 * Passing parameters to the root seems to be done more awkwardly than really
19 * necessary. At least, u32 doesn't seem to use such dirty hacks. To be
20 * verified. FIXME.
21 */
22
23#define PERFECT_HASH_THRESHOLD 64 /* use perfect hash if not bigger */
24#define DEFAULT_HASH_SIZE 64 /* optimized for diffserv */
25
26
1da177e4
LT
27#define PRIV(tp) ((struct tcindex_data *) (tp)->root)
28
29
30struct tcindex_filter_result {
31 struct tcf_exts exts;
32 struct tcf_result res;
33};
34
35struct tcindex_filter {
36 u16 key;
37 struct tcindex_filter_result result;
38 struct tcindex_filter *next;
39};
40
41
42struct tcindex_data {
43 struct tcindex_filter_result *perfect; /* perfect hash; NULL if none */
44 struct tcindex_filter **h; /* imperfect hash; only used if !perfect;
45 NULL if unused */
46 u16 mask; /* AND key with mask */
47 int shift; /* shift ANDed key to the right */
48 int hash; /* hash table size; 0 if undefined */
49 int alloc_hash; /* allocated size */
50 int fall_through; /* 0: only classify if explicit match */
51};
52
5239008b 53static const struct tcf_ext_map tcindex_ext_map = {
1da177e4
LT
54 .police = TCA_TCINDEX_POLICE,
55 .action = TCA_TCINDEX_ACT
56};
57
58static inline int
59tcindex_filter_is_set(struct tcindex_filter_result *r)
60{
61 return tcf_exts_is_predicative(&r->exts) || r->res.classid;
62}
63
64static struct tcindex_filter_result *
65tcindex_lookup(struct tcindex_data *p, u16 key)
66{
67 struct tcindex_filter *f;
68
69 if (p->perfect)
70 return tcindex_filter_is_set(p->perfect + key) ?
71 p->perfect + key : NULL;
72 else if (p->h) {
73 for (f = p->h[key % p->hash]; f; f = f->next)
74 if (f->key == key)
75 return &f->result;
76 }
77
78 return NULL;
79}
80
81
82static int tcindex_classify(struct sk_buff *skb, struct tcf_proto *tp,
83 struct tcf_result *res)
84{
85 struct tcindex_data *p = PRIV(tp);
86 struct tcindex_filter_result *f;
87 int key = (skb->tc_index & p->mask) >> p->shift;
88
aa767bfe
SH
89 pr_debug("tcindex_classify(skb %p,tp %p,res %p),p %p\n",
90 skb, tp, res, p);
1da177e4
LT
91
92 f = tcindex_lookup(p, key);
93 if (!f) {
94 if (!p->fall_through)
95 return -1;
96 res->classid = TC_H_MAKE(TC_H_MAJ(tp->q->handle), key);
97 res->class = 0;
aa767bfe 98 pr_debug("alg 0x%x\n", res->classid);
1da177e4
LT
99 return 0;
100 }
101 *res = f->res;
aa767bfe 102 pr_debug("map 0x%x\n", res->classid);
1da177e4
LT
103
104 return tcf_exts_exec(skb, &f->exts, res);
105}
106
107
108static unsigned long tcindex_get(struct tcf_proto *tp, u32 handle)
109{
110 struct tcindex_data *p = PRIV(tp);
111 struct tcindex_filter_result *r;
112
aa767bfe 113 pr_debug("tcindex_get(tp %p,handle 0x%08x)\n", tp, handle);
1da177e4
LT
114 if (p->perfect && handle >= p->alloc_hash)
115 return 0;
116 r = tcindex_lookup(p, handle);
117 return r && tcindex_filter_is_set(r) ? (unsigned long) r : 0UL;
118}
119
120
121static void tcindex_put(struct tcf_proto *tp, unsigned long f)
122{
aa767bfe 123 pr_debug("tcindex_put(tp %p,f 0x%lx)\n", tp, f);
1da177e4
LT
124}
125
126
127static int tcindex_init(struct tcf_proto *tp)
128{
129 struct tcindex_data *p;
130
aa767bfe
SH
131 pr_debug("tcindex_init(tp %p)\n", tp);
132 p = kzalloc(sizeof(struct tcindex_data), GFP_KERNEL);
1da177e4
LT
133 if (!p)
134 return -ENOMEM;
135
1da177e4
LT
136 p->mask = 0xffff;
137 p->hash = DEFAULT_HASH_SIZE;
138 p->fall_through = 1;
139
140 tp->root = p;
141 return 0;
142}
143
144
145static int
146__tcindex_delete(struct tcf_proto *tp, unsigned long arg, int lock)
147{
148 struct tcindex_data *p = PRIV(tp);
149 struct tcindex_filter_result *r = (struct tcindex_filter_result *) arg;
150 struct tcindex_filter *f = NULL;
151
aa767bfe 152 pr_debug("tcindex_delete(tp %p,arg 0x%lx),p %p,f %p\n", tp, arg, p, f);
1da177e4
LT
153 if (p->perfect) {
154 if (!r->res.class)
155 return -ENOENT;
156 } else {
157 int i;
158 struct tcindex_filter **walk = NULL;
159
160 for (i = 0; i < p->hash; i++)
161 for (walk = p->h+i; *walk; walk = &(*walk)->next)
162 if (&(*walk)->result == r)
163 goto found;
164 return -ENOENT;
165
166found:
167 f = *walk;
168 if (lock)
169 tcf_tree_lock(tp);
170 *walk = f->next;
171 if (lock)
172 tcf_tree_unlock(tp);
173 }
174 tcf_unbind_filter(tp, &r->res);
175 tcf_exts_destroy(tp, &r->exts);
a51482bd 176 kfree(f);
1da177e4
LT
177 return 0;
178}
179
180static int tcindex_delete(struct tcf_proto *tp, unsigned long arg)
181{
182 return __tcindex_delete(tp, arg, 1);
183}
184
185static inline int
186valid_perfect_hash(struct tcindex_data *p)
187{
188 return p->hash > (p->mask >> p->shift);
189}
190
6fa8c014
PM
191static const struct nla_policy tcindex_policy[TCA_TCINDEX_MAX + 1] = {
192 [TCA_TCINDEX_HASH] = { .type = NLA_U32 },
193 [TCA_TCINDEX_MASK] = { .type = NLA_U16 },
194 [TCA_TCINDEX_SHIFT] = { .type = NLA_U32 },
195 [TCA_TCINDEX_FALL_THROUGH] = { .type = NLA_U32 },
196 [TCA_TCINDEX_CLASSID] = { .type = NLA_U32 },
197};
198
1da177e4
LT
199static int
200tcindex_set_parms(struct tcf_proto *tp, unsigned long base, u32 handle,
201 struct tcindex_data *p, struct tcindex_filter_result *r,
add93b61 202 struct nlattr **tb, struct nlattr *est)
1da177e4
LT
203{
204 int err, balloc = 0;
205 struct tcindex_filter_result new_filter_result, *old_r = r;
206 struct tcindex_filter_result cr;
207 struct tcindex_data cp;
208 struct tcindex_filter *f = NULL; /* make gcc behave */
209 struct tcf_exts e;
210
211 err = tcf_exts_validate(tp, tb, est, &e, &tcindex_ext_map);
212 if (err < 0)
213 return err;
10297b99 214
1da177e4
LT
215 memcpy(&cp, p, sizeof(cp));
216 memset(&new_filter_result, 0, sizeof(new_filter_result));
217
218 if (old_r)
219 memcpy(&cr, r, sizeof(cr));
220 else
221 memset(&cr, 0, sizeof(cr));
222
6fa8c014 223 if (tb[TCA_TCINDEX_HASH])
1587bac4 224 cp.hash = nla_get_u32(tb[TCA_TCINDEX_HASH]);
1da177e4 225
6fa8c014 226 if (tb[TCA_TCINDEX_MASK])
1587bac4 227 cp.mask = nla_get_u16(tb[TCA_TCINDEX_MASK]);
1da177e4 228
6fa8c014 229 if (tb[TCA_TCINDEX_SHIFT])
1587bac4 230 cp.shift = nla_get_u32(tb[TCA_TCINDEX_SHIFT]);
1da177e4
LT
231
232 err = -EBUSY;
233 /* Hash already allocated, make sure that we still meet the
234 * requirements for the allocated hash.
235 */
236 if (cp.perfect) {
237 if (!valid_perfect_hash(&cp) ||
238 cp.hash > cp.alloc_hash)
239 goto errout;
240 } else if (cp.h && cp.hash != cp.alloc_hash)
241 goto errout;
242
243 err = -EINVAL;
6fa8c014 244 if (tb[TCA_TCINDEX_FALL_THROUGH])
1587bac4 245 cp.fall_through = nla_get_u32(tb[TCA_TCINDEX_FALL_THROUGH]);
1da177e4
LT
246
247 if (!cp.hash) {
248 /* Hash not specified, use perfect hash if the upper limit
249 * of the hashing index is below the threshold.
250 */
251 if ((cp.mask >> cp.shift) < PERFECT_HASH_THRESHOLD)
252 cp.hash = (cp.mask >> cp.shift)+1;
253 else
254 cp.hash = DEFAULT_HASH_SIZE;
255 }
256
257 if (!cp.perfect && !cp.h)
258 cp.alloc_hash = cp.hash;
259
260 /* Note: this could be as restrictive as if (handle & ~(mask >> shift))
261 * but then, we'd fail handles that may become valid after some future
262 * mask change. While this is extremely unlikely to ever matter,
263 * the check below is safer (and also more backwards-compatible).
264 */
265 if (cp.perfect || valid_perfect_hash(&cp))
266 if (handle >= cp.alloc_hash)
267 goto errout;
268
269
270 err = -ENOMEM;
271 if (!cp.perfect && !cp.h) {
272 if (valid_perfect_hash(&cp)) {
0da974f4 273 cp.perfect = kcalloc(cp.hash, sizeof(*r), GFP_KERNEL);
1da177e4
LT
274 if (!cp.perfect)
275 goto errout;
1da177e4
LT
276 balloc = 1;
277 } else {
0da974f4 278 cp.h = kcalloc(cp.hash, sizeof(f), GFP_KERNEL);
1da177e4
LT
279 if (!cp.h)
280 goto errout;
1da177e4
LT
281 balloc = 2;
282 }
283 }
284
285 if (cp.perfect)
286 r = cp.perfect + handle;
287 else
288 r = tcindex_lookup(&cp, handle) ? : &new_filter_result;
289
290 if (r == &new_filter_result) {
0da974f4 291 f = kzalloc(sizeof(*f), GFP_KERNEL);
1da177e4
LT
292 if (!f)
293 goto errout_alloc;
10297b99 294 }
1da177e4 295
add93b61 296 if (tb[TCA_TCINDEX_CLASSID]) {
1587bac4 297 cr.res.classid = nla_get_u32(tb[TCA_TCINDEX_CLASSID]);
1da177e4 298 tcf_bind_filter(tp, &cr.res, base);
10297b99 299 }
1da177e4
LT
300
301 tcf_exts_change(tp, &cr.exts, &e);
302
303 tcf_tree_lock(tp);
304 if (old_r && old_r != r)
305 memset(old_r, 0, sizeof(*old_r));
306
307 memcpy(p, &cp, sizeof(cp));
308 memcpy(r, &cr, sizeof(cr));
309
310 if (r == &new_filter_result) {
311 struct tcindex_filter **fp;
312
313 f->key = handle;
314 f->result = new_filter_result;
315 f->next = NULL;
316 for (fp = p->h+(handle % p->hash); *fp; fp = &(*fp)->next)
317 /* nothing */;
318 *fp = f;
10297b99 319 }
1da177e4
LT
320 tcf_tree_unlock(tp);
321
322 return 0;
323
324errout_alloc:
325 if (balloc == 1)
326 kfree(cp.perfect);
327 else if (balloc == 2)
328 kfree(cp.h);
329errout:
330 tcf_exts_destroy(tp, &e);
331 return err;
332}
333
334static int
335tcindex_change(struct tcf_proto *tp, unsigned long base, u32 handle,
add93b61 336 struct nlattr **tca, unsigned long *arg)
1da177e4 337{
add93b61
PM
338 struct nlattr *opt = tca[TCA_OPTIONS];
339 struct nlattr *tb[TCA_TCINDEX_MAX + 1];
1da177e4
LT
340 struct tcindex_data *p = PRIV(tp);
341 struct tcindex_filter_result *r = (struct tcindex_filter_result *) *arg;
cee63723 342 int err;
1da177e4 343
aa767bfe 344 pr_debug("tcindex_change(tp %p,handle 0x%08x,tca %p,arg %p),opt %p,"
1da177e4
LT
345 "p %p,r %p,*arg 0x%lx\n",
346 tp, handle, tca, arg, opt, p, r, arg ? *arg : 0L);
347
348 if (!opt)
349 return 0;
350
6fa8c014 351 err = nla_parse_nested(tb, TCA_TCINDEX_MAX, opt, tcindex_policy);
cee63723
PM
352 if (err < 0)
353 return err;
1da177e4 354
add93b61 355 return tcindex_set_parms(tp, base, handle, p, r, tb, tca[TCA_RATE]);
1da177e4
LT
356}
357
358
359static void tcindex_walk(struct tcf_proto *tp, struct tcf_walker *walker)
360{
361 struct tcindex_data *p = PRIV(tp);
aa767bfe 362 struct tcindex_filter *f, *next;
1da177e4
LT
363 int i;
364
aa767bfe 365 pr_debug("tcindex_walk(tp %p,walker %p),p %p\n", tp, walker, p);
1da177e4
LT
366 if (p->perfect) {
367 for (i = 0; i < p->hash; i++) {
368 if (!p->perfect[i].res.class)
369 continue;
370 if (walker->count >= walker->skip) {
371 if (walker->fn(tp,
372 (unsigned long) (p->perfect+i), walker)
373 < 0) {
374 walker->stop = 1;
375 return;
376 }
377 }
378 walker->count++;
379 }
380 }
381 if (!p->h)
382 return;
383 for (i = 0; i < p->hash; i++) {
384 for (f = p->h[i]; f; f = next) {
385 next = f->next;
386 if (walker->count >= walker->skip) {
aa767bfe 387 if (walker->fn(tp, (unsigned long) &f->result,
1da177e4
LT
388 walker) < 0) {
389 walker->stop = 1;
390 return;
391 }
392 }
393 walker->count++;
394 }
395 }
396}
397
398
399static int tcindex_destroy_element(struct tcf_proto *tp,
400 unsigned long arg, struct tcf_walker *walker)
401{
402 return __tcindex_delete(tp, arg, 0);
403}
404
405
406static void tcindex_destroy(struct tcf_proto *tp)
407{
408 struct tcindex_data *p = PRIV(tp);
409 struct tcf_walker walker;
410
aa767bfe 411 pr_debug("tcindex_destroy(tp %p),p %p\n", tp, p);
1da177e4
LT
412 walker.count = 0;
413 walker.skip = 0;
414 walker.fn = &tcindex_destroy_element;
aa767bfe 415 tcindex_walk(tp, &walker);
a51482bd
JJ
416 kfree(p->perfect);
417 kfree(p->h);
1da177e4
LT
418 kfree(p);
419 tp->root = NULL;
420}
421
422
423static int tcindex_dump(struct tcf_proto *tp, unsigned long fh,
424 struct sk_buff *skb, struct tcmsg *t)
425{
426 struct tcindex_data *p = PRIV(tp);
427 struct tcindex_filter_result *r = (struct tcindex_filter_result *) fh;
27a884dc 428 unsigned char *b = skb_tail_pointer(skb);
4b3550ef 429 struct nlattr *nest;
1da177e4 430
aa767bfe
SH
431 pr_debug("tcindex_dump(tp %p,fh 0x%lx,skb %p,t %p),p %p,r %p,b %p\n",
432 tp, fh, skb, t, p, r, b);
433 pr_debug("p->perfect %p p->h %p\n", p->perfect, p->h);
4b3550ef
PM
434
435 nest = nla_nest_start(skb, TCA_OPTIONS);
436 if (nest == NULL)
437 goto nla_put_failure;
438
1da177e4
LT
439 if (!fh) {
440 t->tcm_handle = ~0; /* whatever ... */
24beeab5
PM
441 NLA_PUT_U32(skb, TCA_TCINDEX_HASH, p->hash);
442 NLA_PUT_U16(skb, TCA_TCINDEX_MASK, p->mask);
443 NLA_PUT_U32(skb, TCA_TCINDEX_SHIFT, p->shift);
444 NLA_PUT_U32(skb, TCA_TCINDEX_FALL_THROUGH, p->fall_through);
4b3550ef 445 nla_nest_end(skb, nest);
1da177e4
LT
446 } else {
447 if (p->perfect) {
448 t->tcm_handle = r-p->perfect;
449 } else {
450 struct tcindex_filter *f;
451 int i;
452
453 t->tcm_handle = 0;
454 for (i = 0; !t->tcm_handle && i < p->hash; i++) {
455 for (f = p->h[i]; !t->tcm_handle && f;
456 f = f->next) {
457 if (&f->result == r)
458 t->tcm_handle = f->key;
459 }
460 }
461 }
aa767bfe 462 pr_debug("handle = %d\n", t->tcm_handle);
1da177e4 463 if (r->res.class)
24beeab5 464 NLA_PUT_U32(skb, TCA_TCINDEX_CLASSID, r->res.classid);
1da177e4
LT
465
466 if (tcf_exts_dump(skb, &r->exts, &tcindex_ext_map) < 0)
add93b61 467 goto nla_put_failure;
4b3550ef 468 nla_nest_end(skb, nest);
1da177e4
LT
469
470 if (tcf_exts_dump_stats(skb, &r->exts, &tcindex_ext_map) < 0)
add93b61 471 goto nla_put_failure;
1da177e4 472 }
10297b99 473
1da177e4
LT
474 return skb->len;
475
add93b61 476nla_put_failure:
dc5fc579 477 nlmsg_trim(skb, b);
1da177e4
LT
478 return -1;
479}
480
2eb9d75c 481static struct tcf_proto_ops cls_tcindex_ops __read_mostly = {
1da177e4
LT
482 .kind = "tcindex",
483 .classify = tcindex_classify,
484 .init = tcindex_init,
485 .destroy = tcindex_destroy,
486 .get = tcindex_get,
487 .put = tcindex_put,
488 .change = tcindex_change,
489 .delete = tcindex_delete,
490 .walk = tcindex_walk,
491 .dump = tcindex_dump,
492 .owner = THIS_MODULE,
493};
494
495static int __init init_tcindex(void)
496{
497 return register_tcf_proto_ops(&cls_tcindex_ops);
498}
499
10297b99 500static void __exit exit_tcindex(void)
1da177e4
LT
501{
502 unregister_tcf_proto_ops(&cls_tcindex_ops);
503}
504
505module_init(init_tcindex)
506module_exit(exit_tcindex)
507MODULE_LICENSE("GPL");