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Commit | Line | Data |
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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 | ||
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 | ||
51 | struct tcindex_filter_result { | |
52 | struct tcf_exts exts; | |
53 | struct tcf_result res; | |
54 | }; | |
55 | ||
56 | struct tcindex_filter { | |
57 | u16 key; | |
58 | struct tcindex_filter_result result; | |
59 | struct tcindex_filter *next; | |
60 | }; | |
61 | ||
62 | ||
63 | struct 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 | ||
74 | static struct tcf_ext_map tcindex_ext_map = { | |
75 | .police = TCA_TCINDEX_POLICE, | |
76 | .action = TCA_TCINDEX_ACT | |
77 | }; | |
78 | ||
79 | static inline int | |
80 | tcindex_filter_is_set(struct tcindex_filter_result *r) | |
81 | { | |
82 | return tcf_exts_is_predicative(&r->exts) || r->res.classid; | |
83 | } | |
84 | ||
85 | static struct tcindex_filter_result * | |
86 | tcindex_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 | ||
103 | static 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 | ||
128 | static 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 | ||
141 | static 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 | ||
147 | static 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 | ||
166 | static 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 | ||
187 | found: | |
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); | |
a51482bd | 197 | kfree(f); |
1da177e4 LT |
198 | return 0; |
199 | } | |
200 | ||
201 | static int tcindex_delete(struct tcf_proto *tp, unsigned long arg) | |
202 | { | |
203 | return __tcindex_delete(tp, arg, 1); | |
204 | } | |
205 | ||
206 | static inline int | |
207 | valid_perfect_hash(struct tcindex_data *p) | |
208 | { | |
209 | return p->hash > (p->mask >> p->shift); | |
210 | } | |
211 | ||
212 | static int | |
213 | tcindex_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 | ||
354 | errout_alloc: | |
355 | if (balloc == 1) | |
356 | kfree(cp.perfect); | |
357 | else if (balloc == 2) | |
358 | kfree(cp.h); | |
359 | errout: | |
360 | tcf_exts_destroy(tp, &e); | |
361 | return err; | |
362 | } | |
363 | ||
364 | static int | |
365 | tcindex_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 | ||
387 | static 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 | ||
427 | static 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 | ||
434 | static 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); | |
a51482bd JJ |
444 | kfree(p->perfect); |
445 | kfree(p->h); | |
1da177e4 LT |
446 | kfree(p); |
447 | tp->root = NULL; | |
448 | } | |
449 | ||
450 | ||
451 | static 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 | ||
502 | rtattr_failure: | |
503 | skb_trim(skb, b - skb->data); | |
504 | return -1; | |
505 | } | |
506 | ||
507 | static 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 | ||
522 | static int __init init_tcindex(void) | |
523 | { | |
524 | return register_tcf_proto_ops(&cls_tcindex_ops); | |
525 | } | |
526 | ||
527 | static void __exit exit_tcindex(void) | |
528 | { | |
529 | unregister_tcf_proto_ops(&cls_tcindex_ops); | |
530 | } | |
531 | ||
532 | module_init(init_tcindex) | |
533 | module_exit(exit_tcindex) | |
534 | MODULE_LICENSE("GPL"); |