blob: 9f921174c8ab39d33e9544c9b78051b3b8a12cdf [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * net/sched/cls_tcindex.c Packet classifier for skb->tc_index
3 *
4 * Written 1998,1999 by Werner Almesberger, EPFL ICA
5 */
6
7#include <linux/config.h>
8#include <linux/module.h>
9#include <linux/types.h>
10#include <linux/kernel.h>
11#include <linux/skbuff.h>
12#include <linux/errno.h>
13#include <linux/netdevice.h>
14#include <net/ip.h>
15#include <net/act_api.h>
16#include <net/pkt_cls.h>
17#include <net/route.h>
18
19
20/*
21 * Not quite sure if we need all the xchgs Alexey uses when accessing things.
22 * Can always add them later ... :)
23 */
24
25/*
26 * Passing parameters to the root seems to be done more awkwardly than really
27 * necessary. At least, u32 doesn't seem to use such dirty hacks. To be
28 * verified. FIXME.
29 */
30
31#define PERFECT_HASH_THRESHOLD 64 /* use perfect hash if not bigger */
32#define DEFAULT_HASH_SIZE 64 /* optimized for diffserv */
33
34
35#if 1 /* control */
36#define DPRINTK(format,args...) printk(KERN_DEBUG format,##args)
37#else
38#define DPRINTK(format,args...)
39#endif
40
41#if 0 /* data */
42#define D2PRINTK(format,args...) printk(KERN_DEBUG format,##args)
43#else
44#define D2PRINTK(format,args...)
45#endif
46
47
48#define PRIV(tp) ((struct tcindex_data *) (tp)->root)
49
50
51struct tcindex_filter_result {
52 struct tcf_exts exts;
53 struct tcf_result res;
54};
55
56struct tcindex_filter {
57 u16 key;
58 struct tcindex_filter_result result;
59 struct tcindex_filter *next;
60};
61
62
63struct tcindex_data {
64 struct tcindex_filter_result *perfect; /* perfect hash; NULL if none */
65 struct tcindex_filter **h; /* imperfect hash; only used if !perfect;
66 NULL if unused */
67 u16 mask; /* AND key with mask */
68 int shift; /* shift ANDed key to the right */
69 int hash; /* hash table size; 0 if undefined */
70 int alloc_hash; /* allocated size */
71 int fall_through; /* 0: only classify if explicit match */
72};
73
74static struct tcf_ext_map tcindex_ext_map = {
75 .police = TCA_TCINDEX_POLICE,
76 .action = TCA_TCINDEX_ACT
77};
78
79static inline int
80tcindex_filter_is_set(struct tcindex_filter_result *r)
81{
82 return tcf_exts_is_predicative(&r->exts) || r->res.classid;
83}
84
85static struct tcindex_filter_result *
86tcindex_lookup(struct tcindex_data *p, u16 key)
87{
88 struct tcindex_filter *f;
89
90 if (p->perfect)
91 return tcindex_filter_is_set(p->perfect + key) ?
92 p->perfect + key : NULL;
93 else if (p->h) {
94 for (f = p->h[key % p->hash]; f; f = f->next)
95 if (f->key == key)
96 return &f->result;
97 }
98
99 return NULL;
100}
101
102
103static int tcindex_classify(struct sk_buff *skb, struct tcf_proto *tp,
104 struct tcf_result *res)
105{
106 struct tcindex_data *p = PRIV(tp);
107 struct tcindex_filter_result *f;
108 int key = (skb->tc_index & p->mask) >> p->shift;
109
110 D2PRINTK("tcindex_classify(skb %p,tp %p,res %p),p %p\n",skb,tp,res,p);
111
112 f = tcindex_lookup(p, key);
113 if (!f) {
114 if (!p->fall_through)
115 return -1;
116 res->classid = TC_H_MAKE(TC_H_MAJ(tp->q->handle), key);
117 res->class = 0;
118 D2PRINTK("alg 0x%x\n",res->classid);
119 return 0;
120 }
121 *res = f->res;
122 D2PRINTK("map 0x%x\n",res->classid);
123
124 return tcf_exts_exec(skb, &f->exts, res);
125}
126
127
128static unsigned long tcindex_get(struct tcf_proto *tp, u32 handle)
129{
130 struct tcindex_data *p = PRIV(tp);
131 struct tcindex_filter_result *r;
132
133 DPRINTK("tcindex_get(tp %p,handle 0x%08x)\n",tp,handle);
134 if (p->perfect && handle >= p->alloc_hash)
135 return 0;
136 r = tcindex_lookup(p, handle);
137 return r && tcindex_filter_is_set(r) ? (unsigned long) r : 0UL;
138}
139
140
141static void tcindex_put(struct tcf_proto *tp, unsigned long f)
142{
143 DPRINTK("tcindex_put(tp %p,f 0x%lx)\n",tp,f);
144}
145
146
147static int tcindex_init(struct tcf_proto *tp)
148{
149 struct tcindex_data *p;
150
151 DPRINTK("tcindex_init(tp %p)\n",tp);
152 p = kmalloc(sizeof(struct tcindex_data),GFP_KERNEL);
153 if (!p)
154 return -ENOMEM;
155
156 memset(p, 0, sizeof(*p));
157 p->mask = 0xffff;
158 p->hash = DEFAULT_HASH_SIZE;
159 p->fall_through = 1;
160
161 tp->root = p;
162 return 0;
163}
164
165
166static int
167__tcindex_delete(struct tcf_proto *tp, unsigned long arg, int lock)
168{
169 struct tcindex_data *p = PRIV(tp);
170 struct tcindex_filter_result *r = (struct tcindex_filter_result *) arg;
171 struct tcindex_filter *f = NULL;
172
173 DPRINTK("tcindex_delete(tp %p,arg 0x%lx),p %p,f %p\n",tp,arg,p,f);
174 if (p->perfect) {
175 if (!r->res.class)
176 return -ENOENT;
177 } else {
178 int i;
179 struct tcindex_filter **walk = NULL;
180
181 for (i = 0; i < p->hash; i++)
182 for (walk = p->h+i; *walk; walk = &(*walk)->next)
183 if (&(*walk)->result == r)
184 goto found;
185 return -ENOENT;
186
187found:
188 f = *walk;
189 if (lock)
190 tcf_tree_lock(tp);
191 *walk = f->next;
192 if (lock)
193 tcf_tree_unlock(tp);
194 }
195 tcf_unbind_filter(tp, &r->res);
196 tcf_exts_destroy(tp, &r->exts);
Jesper Juhla51482b2005-11-08 09:41:34 -0800197 kfree(f);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 return 0;
199}
200
201static int tcindex_delete(struct tcf_proto *tp, unsigned long arg)
202{
203 return __tcindex_delete(tp, arg, 1);
204}
205
206static inline int
207valid_perfect_hash(struct tcindex_data *p)
208{
209 return p->hash > (p->mask >> p->shift);
210}
211
212static int
213tcindex_set_parms(struct tcf_proto *tp, unsigned long base, u32 handle,
214 struct tcindex_data *p, struct tcindex_filter_result *r,
215 struct rtattr **tb, struct rtattr *est)
216{
217 int err, balloc = 0;
218 struct tcindex_filter_result new_filter_result, *old_r = r;
219 struct tcindex_filter_result cr;
220 struct tcindex_data cp;
221 struct tcindex_filter *f = NULL; /* make gcc behave */
222 struct tcf_exts e;
223
224 err = tcf_exts_validate(tp, tb, est, &e, &tcindex_ext_map);
225 if (err < 0)
226 return err;
227
228 memcpy(&cp, p, sizeof(cp));
229 memset(&new_filter_result, 0, sizeof(new_filter_result));
230
231 if (old_r)
232 memcpy(&cr, r, sizeof(cr));
233 else
234 memset(&cr, 0, sizeof(cr));
235
236 err = -EINVAL;
237 if (tb[TCA_TCINDEX_HASH-1]) {
238 if (RTA_PAYLOAD(tb[TCA_TCINDEX_HASH-1]) < sizeof(u32))
239 goto errout;
240 cp.hash = *(u32 *) RTA_DATA(tb[TCA_TCINDEX_HASH-1]);
241 }
242
243 if (tb[TCA_TCINDEX_MASK-1]) {
244 if (RTA_PAYLOAD(tb[TCA_TCINDEX_MASK-1]) < sizeof(u16))
245 goto errout;
246 cp.mask = *(u16 *) RTA_DATA(tb[TCA_TCINDEX_MASK-1]);
247 }
248
249 if (tb[TCA_TCINDEX_SHIFT-1]) {
250 if (RTA_PAYLOAD(tb[TCA_TCINDEX_SHIFT-1]) < sizeof(u16))
251 goto errout;
252 cp.shift = *(u16 *) RTA_DATA(tb[TCA_TCINDEX_SHIFT-1]);
253 }
254
255 err = -EBUSY;
256 /* Hash already allocated, make sure that we still meet the
257 * requirements for the allocated hash.
258 */
259 if (cp.perfect) {
260 if (!valid_perfect_hash(&cp) ||
261 cp.hash > cp.alloc_hash)
262 goto errout;
263 } else if (cp.h && cp.hash != cp.alloc_hash)
264 goto errout;
265
266 err = -EINVAL;
267 if (tb[TCA_TCINDEX_FALL_THROUGH-1]) {
268 if (RTA_PAYLOAD(tb[TCA_TCINDEX_FALL_THROUGH-1]) < sizeof(u32))
269 goto errout;
270 cp.fall_through =
271 *(u32 *) RTA_DATA(tb[TCA_TCINDEX_FALL_THROUGH-1]);
272 }
273
274 if (!cp.hash) {
275 /* Hash not specified, use perfect hash if the upper limit
276 * of the hashing index is below the threshold.
277 */
278 if ((cp.mask >> cp.shift) < PERFECT_HASH_THRESHOLD)
279 cp.hash = (cp.mask >> cp.shift)+1;
280 else
281 cp.hash = DEFAULT_HASH_SIZE;
282 }
283
284 if (!cp.perfect && !cp.h)
285 cp.alloc_hash = cp.hash;
286
287 /* Note: this could be as restrictive as if (handle & ~(mask >> shift))
288 * but then, we'd fail handles that may become valid after some future
289 * mask change. While this is extremely unlikely to ever matter,
290 * the check below is safer (and also more backwards-compatible).
291 */
292 if (cp.perfect || valid_perfect_hash(&cp))
293 if (handle >= cp.alloc_hash)
294 goto errout;
295
296
297 err = -ENOMEM;
298 if (!cp.perfect && !cp.h) {
299 if (valid_perfect_hash(&cp)) {
300 cp.perfect = kmalloc(cp.hash * sizeof(*r), GFP_KERNEL);
301 if (!cp.perfect)
302 goto errout;
303 memset(cp.perfect, 0, cp.hash * sizeof(*r));
304 balloc = 1;
305 } else {
306 cp.h = kmalloc(cp.hash * sizeof(f), GFP_KERNEL);
307 if (!cp.h)
308 goto errout;
309 memset(cp.h, 0, cp.hash * sizeof(f));
310 balloc = 2;
311 }
312 }
313
314 if (cp.perfect)
315 r = cp.perfect + handle;
316 else
317 r = tcindex_lookup(&cp, handle) ? : &new_filter_result;
318
319 if (r == &new_filter_result) {
320 f = kmalloc(sizeof(*f), GFP_KERNEL);
321 if (!f)
322 goto errout_alloc;
323 memset(f, 0, sizeof(*f));
324 }
325
326 if (tb[TCA_TCINDEX_CLASSID-1]) {
327 cr.res.classid = *(u32 *) RTA_DATA(tb[TCA_TCINDEX_CLASSID-1]);
328 tcf_bind_filter(tp, &cr.res, base);
329 }
330
331 tcf_exts_change(tp, &cr.exts, &e);
332
333 tcf_tree_lock(tp);
334 if (old_r && old_r != r)
335 memset(old_r, 0, sizeof(*old_r));
336
337 memcpy(p, &cp, sizeof(cp));
338 memcpy(r, &cr, sizeof(cr));
339
340 if (r == &new_filter_result) {
341 struct tcindex_filter **fp;
342
343 f->key = handle;
344 f->result = new_filter_result;
345 f->next = NULL;
346 for (fp = p->h+(handle % p->hash); *fp; fp = &(*fp)->next)
347 /* nothing */;
348 *fp = f;
349 }
350 tcf_tree_unlock(tp);
351
352 return 0;
353
354errout_alloc:
355 if (balloc == 1)
356 kfree(cp.perfect);
357 else if (balloc == 2)
358 kfree(cp.h);
359errout:
360 tcf_exts_destroy(tp, &e);
361 return err;
362}
363
364static int
365tcindex_change(struct tcf_proto *tp, unsigned long base, u32 handle,
366 struct rtattr **tca, unsigned long *arg)
367{
368 struct rtattr *opt = tca[TCA_OPTIONS-1];
369 struct rtattr *tb[TCA_TCINDEX_MAX];
370 struct tcindex_data *p = PRIV(tp);
371 struct tcindex_filter_result *r = (struct tcindex_filter_result *) *arg;
372
373 DPRINTK("tcindex_change(tp %p,handle 0x%08x,tca %p,arg %p),opt %p,"
374 "p %p,r %p,*arg 0x%lx\n",
375 tp, handle, tca, arg, opt, p, r, arg ? *arg : 0L);
376
377 if (!opt)
378 return 0;
379
380 if (rtattr_parse_nested(tb, TCA_TCINDEX_MAX, opt) < 0)
381 return -EINVAL;
382
383 return tcindex_set_parms(tp, base, handle, p, r, tb, tca[TCA_RATE-1]);
384}
385
386
387static void tcindex_walk(struct tcf_proto *tp, struct tcf_walker *walker)
388{
389 struct tcindex_data *p = PRIV(tp);
390 struct tcindex_filter *f,*next;
391 int i;
392
393 DPRINTK("tcindex_walk(tp %p,walker %p),p %p\n",tp,walker,p);
394 if (p->perfect) {
395 for (i = 0; i < p->hash; i++) {
396 if (!p->perfect[i].res.class)
397 continue;
398 if (walker->count >= walker->skip) {
399 if (walker->fn(tp,
400 (unsigned long) (p->perfect+i), walker)
401 < 0) {
402 walker->stop = 1;
403 return;
404 }
405 }
406 walker->count++;
407 }
408 }
409 if (!p->h)
410 return;
411 for (i = 0; i < p->hash; i++) {
412 for (f = p->h[i]; f; f = next) {
413 next = f->next;
414 if (walker->count >= walker->skip) {
415 if (walker->fn(tp,(unsigned long) &f->result,
416 walker) < 0) {
417 walker->stop = 1;
418 return;
419 }
420 }
421 walker->count++;
422 }
423 }
424}
425
426
427static int tcindex_destroy_element(struct tcf_proto *tp,
428 unsigned long arg, struct tcf_walker *walker)
429{
430 return __tcindex_delete(tp, arg, 0);
431}
432
433
434static void tcindex_destroy(struct tcf_proto *tp)
435{
436 struct tcindex_data *p = PRIV(tp);
437 struct tcf_walker walker;
438
439 DPRINTK("tcindex_destroy(tp %p),p %p\n",tp,p);
440 walker.count = 0;
441 walker.skip = 0;
442 walker.fn = &tcindex_destroy_element;
443 tcindex_walk(tp,&walker);
Jesper Juhla51482b2005-11-08 09:41:34 -0800444 kfree(p->perfect);
445 kfree(p->h);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 kfree(p);
447 tp->root = NULL;
448}
449
450
451static int tcindex_dump(struct tcf_proto *tp, unsigned long fh,
452 struct sk_buff *skb, struct tcmsg *t)
453{
454 struct tcindex_data *p = PRIV(tp);
455 struct tcindex_filter_result *r = (struct tcindex_filter_result *) fh;
456 unsigned char *b = skb->tail;
457 struct rtattr *rta;
458
459 DPRINTK("tcindex_dump(tp %p,fh 0x%lx,skb %p,t %p),p %p,r %p,b %p\n",
460 tp,fh,skb,t,p,r,b);
461 DPRINTK("p->perfect %p p->h %p\n",p->perfect,p->h);
462 rta = (struct rtattr *) b;
463 RTA_PUT(skb,TCA_OPTIONS,0,NULL);
464 if (!fh) {
465 t->tcm_handle = ~0; /* whatever ... */
466 RTA_PUT(skb,TCA_TCINDEX_HASH,sizeof(p->hash),&p->hash);
467 RTA_PUT(skb,TCA_TCINDEX_MASK,sizeof(p->mask),&p->mask);
468 RTA_PUT(skb,TCA_TCINDEX_SHIFT,sizeof(p->shift),&p->shift);
469 RTA_PUT(skb,TCA_TCINDEX_FALL_THROUGH,sizeof(p->fall_through),
470 &p->fall_through);
471 rta->rta_len = skb->tail-b;
472 } else {
473 if (p->perfect) {
474 t->tcm_handle = r-p->perfect;
475 } else {
476 struct tcindex_filter *f;
477 int i;
478
479 t->tcm_handle = 0;
480 for (i = 0; !t->tcm_handle && i < p->hash; i++) {
481 for (f = p->h[i]; !t->tcm_handle && f;
482 f = f->next) {
483 if (&f->result == r)
484 t->tcm_handle = f->key;
485 }
486 }
487 }
488 DPRINTK("handle = %d\n",t->tcm_handle);
489 if (r->res.class)
490 RTA_PUT(skb, TCA_TCINDEX_CLASSID, 4, &r->res.classid);
491
492 if (tcf_exts_dump(skb, &r->exts, &tcindex_ext_map) < 0)
493 goto rtattr_failure;
494 rta->rta_len = skb->tail-b;
495
496 if (tcf_exts_dump_stats(skb, &r->exts, &tcindex_ext_map) < 0)
497 goto rtattr_failure;
498 }
499
500 return skb->len;
501
502rtattr_failure:
503 skb_trim(skb, b - skb->data);
504 return -1;
505}
506
507static struct tcf_proto_ops cls_tcindex_ops = {
508 .next = NULL,
509 .kind = "tcindex",
510 .classify = tcindex_classify,
511 .init = tcindex_init,
512 .destroy = tcindex_destroy,
513 .get = tcindex_get,
514 .put = tcindex_put,
515 .change = tcindex_change,
516 .delete = tcindex_delete,
517 .walk = tcindex_walk,
518 .dump = tcindex_dump,
519 .owner = THIS_MODULE,
520};
521
522static int __init init_tcindex(void)
523{
524 return register_tcf_proto_ops(&cls_tcindex_ops);
525}
526
527static void __exit exit_tcindex(void)
528{
529 unregister_tcf_proto_ops(&cls_tcindex_ops);
530}
531
532module_init(init_tcindex)
533module_exit(exit_tcindex)
534MODULE_LICENSE("GPL");