Commit | Line | Data |
---|---|---|
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> | |
12 | #include <linux/netdevice.h> | |
13 | #include <net/ip.h> | |
14 | #include <net/act_api.h> | |
15 | #include <net/pkt_cls.h> | |
16 | #include <net/route.h> | |
17 | ||
18 | ||
19 | /* | |
20 | * Not quite sure if we need all the xchgs Alexey uses when accessing things. | |
21 | * Can always add them later ... :) | |
22 | */ | |
23 | ||
24 | /* | |
25 | * Passing parameters to the root seems to be done more awkwardly than really | |
26 | * necessary. At least, u32 doesn't seem to use such dirty hacks. To be | |
27 | * verified. FIXME. | |
28 | */ | |
29 | ||
30 | #define PERFECT_HASH_THRESHOLD 64 /* use perfect hash if not bigger */ | |
31 | #define DEFAULT_HASH_SIZE 64 /* optimized for diffserv */ | |
32 | ||
33 | ||
34 | #if 1 /* control */ | |
35 | #define DPRINTK(format,args...) printk(KERN_DEBUG format,##args) | |
36 | #else | |
37 | #define DPRINTK(format,args...) | |
38 | #endif | |
39 | ||
40 | #if 0 /* data */ | |
41 | #define D2PRINTK(format,args...) printk(KERN_DEBUG format,##args) | |
42 | #else | |
43 | #define D2PRINTK(format,args...) | |
44 | #endif | |
45 | ||
46 | ||
47 | #define PRIV(tp) ((struct tcindex_data *) (tp)->root) | |
48 | ||
49 | ||
50 | struct tcindex_filter_result { | |
51 | struct tcf_exts exts; | |
52 | struct tcf_result res; | |
53 | }; | |
54 | ||
55 | struct tcindex_filter { | |
56 | u16 key; | |
57 | struct tcindex_filter_result result; | |
58 | struct tcindex_filter *next; | |
59 | }; | |
60 | ||
61 | ||
62 | struct tcindex_data { | |
63 | struct tcindex_filter_result *perfect; /* perfect hash; NULL if none */ | |
64 | struct tcindex_filter **h; /* imperfect hash; only used if !perfect; | |
65 | NULL if unused */ | |
66 | u16 mask; /* AND key with mask */ | |
67 | int shift; /* shift ANDed key to the right */ | |
68 | int hash; /* hash table size; 0 if undefined */ | |
69 | int alloc_hash; /* allocated size */ | |
70 | int fall_through; /* 0: only classify if explicit match */ | |
71 | }; | |
72 | ||
73 | static struct tcf_ext_map tcindex_ext_map = { | |
74 | .police = TCA_TCINDEX_POLICE, | |
75 | .action = TCA_TCINDEX_ACT | |
76 | }; | |
77 | ||
78 | static inline int | |
79 | tcindex_filter_is_set(struct tcindex_filter_result *r) | |
80 | { | |
81 | return tcf_exts_is_predicative(&r->exts) || r->res.classid; | |
82 | } | |
83 | ||
84 | static struct tcindex_filter_result * | |
85 | tcindex_lookup(struct tcindex_data *p, u16 key) | |
86 | { | |
87 | struct tcindex_filter *f; | |
88 | ||
89 | if (p->perfect) | |
90 | return tcindex_filter_is_set(p->perfect + key) ? | |
91 | p->perfect + key : NULL; | |
92 | else if (p->h) { | |
93 | for (f = p->h[key % p->hash]; f; f = f->next) | |
94 | if (f->key == key) | |
95 | return &f->result; | |
96 | } | |
97 | ||
98 | return NULL; | |
99 | } | |
100 | ||
101 | ||
102 | static int tcindex_classify(struct sk_buff *skb, struct tcf_proto *tp, | |
103 | struct tcf_result *res) | |
104 | { | |
105 | struct tcindex_data *p = PRIV(tp); | |
106 | struct tcindex_filter_result *f; | |
107 | int key = (skb->tc_index & p->mask) >> p->shift; | |
108 | ||
109 | D2PRINTK("tcindex_classify(skb %p,tp %p,res %p),p %p\n",skb,tp,res,p); | |
110 | ||
111 | f = tcindex_lookup(p, key); | |
112 | if (!f) { | |
113 | if (!p->fall_through) | |
114 | return -1; | |
115 | res->classid = TC_H_MAKE(TC_H_MAJ(tp->q->handle), key); | |
116 | res->class = 0; | |
117 | D2PRINTK("alg 0x%x\n",res->classid); | |
118 | return 0; | |
119 | } | |
120 | *res = f->res; | |
121 | D2PRINTK("map 0x%x\n",res->classid); | |
122 | ||
123 | return tcf_exts_exec(skb, &f->exts, res); | |
124 | } | |
125 | ||
126 | ||
127 | static unsigned long tcindex_get(struct tcf_proto *tp, u32 handle) | |
128 | { | |
129 | struct tcindex_data *p = PRIV(tp); | |
130 | struct tcindex_filter_result *r; | |
131 | ||
132 | DPRINTK("tcindex_get(tp %p,handle 0x%08x)\n",tp,handle); | |
133 | if (p->perfect && handle >= p->alloc_hash) | |
134 | return 0; | |
135 | r = tcindex_lookup(p, handle); | |
136 | return r && tcindex_filter_is_set(r) ? (unsigned long) r : 0UL; | |
137 | } | |
138 | ||
139 | ||
140 | static void tcindex_put(struct tcf_proto *tp, unsigned long f) | |
141 | { | |
142 | DPRINTK("tcindex_put(tp %p,f 0x%lx)\n",tp,f); | |
143 | } | |
144 | ||
145 | ||
146 | static int tcindex_init(struct tcf_proto *tp) | |
147 | { | |
148 | struct tcindex_data *p; | |
149 | ||
150 | DPRINTK("tcindex_init(tp %p)\n",tp); | |
151 | p = kmalloc(sizeof(struct tcindex_data),GFP_KERNEL); | |
152 | if (!p) | |
153 | return -ENOMEM; | |
154 | ||
155 | memset(p, 0, sizeof(*p)); | |
156 | p->mask = 0xffff; | |
157 | p->hash = DEFAULT_HASH_SIZE; | |
158 | p->fall_through = 1; | |
159 | ||
160 | tp->root = p; | |
161 | return 0; | |
162 | } | |
163 | ||
164 | ||
165 | static int | |
166 | __tcindex_delete(struct tcf_proto *tp, unsigned long arg, int lock) | |
167 | { | |
168 | struct tcindex_data *p = PRIV(tp); | |
169 | struct tcindex_filter_result *r = (struct tcindex_filter_result *) arg; | |
170 | struct tcindex_filter *f = NULL; | |
171 | ||
172 | DPRINTK("tcindex_delete(tp %p,arg 0x%lx),p %p,f %p\n",tp,arg,p,f); | |
173 | if (p->perfect) { | |
174 | if (!r->res.class) | |
175 | return -ENOENT; | |
176 | } else { | |
177 | int i; | |
178 | struct tcindex_filter **walk = NULL; | |
179 | ||
180 | for (i = 0; i < p->hash; i++) | |
181 | for (walk = p->h+i; *walk; walk = &(*walk)->next) | |
182 | if (&(*walk)->result == r) | |
183 | goto found; | |
184 | return -ENOENT; | |
185 | ||
186 | found: | |
187 | f = *walk; | |
188 | if (lock) | |
189 | tcf_tree_lock(tp); | |
190 | *walk = f->next; | |
191 | if (lock) | |
192 | tcf_tree_unlock(tp); | |
193 | } | |
194 | tcf_unbind_filter(tp, &r->res); | |
195 | tcf_exts_destroy(tp, &r->exts); | |
a51482bd | 196 | kfree(f); |
1da177e4 LT |
197 | return 0; |
198 | } | |
199 | ||
200 | static int tcindex_delete(struct tcf_proto *tp, unsigned long arg) | |
201 | { | |
202 | return __tcindex_delete(tp, arg, 1); | |
203 | } | |
204 | ||
205 | static inline int | |
206 | valid_perfect_hash(struct tcindex_data *p) | |
207 | { | |
208 | return p->hash > (p->mask >> p->shift); | |
209 | } | |
210 | ||
211 | static int | |
212 | tcindex_set_parms(struct tcf_proto *tp, unsigned long base, u32 handle, | |
213 | struct tcindex_data *p, struct tcindex_filter_result *r, | |
214 | struct rtattr **tb, struct rtattr *est) | |
215 | { | |
216 | int err, balloc = 0; | |
217 | struct tcindex_filter_result new_filter_result, *old_r = r; | |
218 | struct tcindex_filter_result cr; | |
219 | struct tcindex_data cp; | |
220 | struct tcindex_filter *f = NULL; /* make gcc behave */ | |
221 | struct tcf_exts e; | |
222 | ||
223 | err = tcf_exts_validate(tp, tb, est, &e, &tcindex_ext_map); | |
224 | if (err < 0) | |
225 | return err; | |
226 | ||
227 | memcpy(&cp, p, sizeof(cp)); | |
228 | memset(&new_filter_result, 0, sizeof(new_filter_result)); | |
229 | ||
230 | if (old_r) | |
231 | memcpy(&cr, r, sizeof(cr)); | |
232 | else | |
233 | memset(&cr, 0, sizeof(cr)); | |
234 | ||
235 | err = -EINVAL; | |
236 | if (tb[TCA_TCINDEX_HASH-1]) { | |
237 | if (RTA_PAYLOAD(tb[TCA_TCINDEX_HASH-1]) < sizeof(u32)) | |
238 | goto errout; | |
239 | cp.hash = *(u32 *) RTA_DATA(tb[TCA_TCINDEX_HASH-1]); | |
240 | } | |
241 | ||
242 | if (tb[TCA_TCINDEX_MASK-1]) { | |
243 | if (RTA_PAYLOAD(tb[TCA_TCINDEX_MASK-1]) < sizeof(u16)) | |
244 | goto errout; | |
245 | cp.mask = *(u16 *) RTA_DATA(tb[TCA_TCINDEX_MASK-1]); | |
246 | } | |
247 | ||
248 | if (tb[TCA_TCINDEX_SHIFT-1]) { | |
249 | if (RTA_PAYLOAD(tb[TCA_TCINDEX_SHIFT-1]) < sizeof(u16)) | |
250 | goto errout; | |
251 | cp.shift = *(u16 *) RTA_DATA(tb[TCA_TCINDEX_SHIFT-1]); | |
252 | } | |
253 | ||
254 | err = -EBUSY; | |
255 | /* Hash already allocated, make sure that we still meet the | |
256 | * requirements for the allocated hash. | |
257 | */ | |
258 | if (cp.perfect) { | |
259 | if (!valid_perfect_hash(&cp) || | |
260 | cp.hash > cp.alloc_hash) | |
261 | goto errout; | |
262 | } else if (cp.h && cp.hash != cp.alloc_hash) | |
263 | goto errout; | |
264 | ||
265 | err = -EINVAL; | |
266 | if (tb[TCA_TCINDEX_FALL_THROUGH-1]) { | |
267 | if (RTA_PAYLOAD(tb[TCA_TCINDEX_FALL_THROUGH-1]) < sizeof(u32)) | |
268 | goto errout; | |
269 | cp.fall_through = | |
270 | *(u32 *) RTA_DATA(tb[TCA_TCINDEX_FALL_THROUGH-1]); | |
271 | } | |
272 | ||
273 | if (!cp.hash) { | |
274 | /* Hash not specified, use perfect hash if the upper limit | |
275 | * of the hashing index is below the threshold. | |
276 | */ | |
277 | if ((cp.mask >> cp.shift) < PERFECT_HASH_THRESHOLD) | |
278 | cp.hash = (cp.mask >> cp.shift)+1; | |
279 | else | |
280 | cp.hash = DEFAULT_HASH_SIZE; | |
281 | } | |
282 | ||
283 | if (!cp.perfect && !cp.h) | |
284 | cp.alloc_hash = cp.hash; | |
285 | ||
286 | /* Note: this could be as restrictive as if (handle & ~(mask >> shift)) | |
287 | * but then, we'd fail handles that may become valid after some future | |
288 | * mask change. While this is extremely unlikely to ever matter, | |
289 | * the check below is safer (and also more backwards-compatible). | |
290 | */ | |
291 | if (cp.perfect || valid_perfect_hash(&cp)) | |
292 | if (handle >= cp.alloc_hash) | |
293 | goto errout; | |
294 | ||
295 | ||
296 | err = -ENOMEM; | |
297 | if (!cp.perfect && !cp.h) { | |
298 | if (valid_perfect_hash(&cp)) { | |
299 | cp.perfect = kmalloc(cp.hash * sizeof(*r), GFP_KERNEL); | |
300 | if (!cp.perfect) | |
301 | goto errout; | |
302 | memset(cp.perfect, 0, cp.hash * sizeof(*r)); | |
303 | balloc = 1; | |
304 | } else { | |
305 | cp.h = kmalloc(cp.hash * sizeof(f), GFP_KERNEL); | |
306 | if (!cp.h) | |
307 | goto errout; | |
308 | memset(cp.h, 0, cp.hash * sizeof(f)); | |
309 | balloc = 2; | |
310 | } | |
311 | } | |
312 | ||
313 | if (cp.perfect) | |
314 | r = cp.perfect + handle; | |
315 | else | |
316 | r = tcindex_lookup(&cp, handle) ? : &new_filter_result; | |
317 | ||
318 | if (r == &new_filter_result) { | |
319 | f = kmalloc(sizeof(*f), GFP_KERNEL); | |
320 | if (!f) | |
321 | goto errout_alloc; | |
322 | memset(f, 0, sizeof(*f)); | |
323 | } | |
324 | ||
325 | if (tb[TCA_TCINDEX_CLASSID-1]) { | |
326 | cr.res.classid = *(u32 *) RTA_DATA(tb[TCA_TCINDEX_CLASSID-1]); | |
327 | tcf_bind_filter(tp, &cr.res, base); | |
328 | } | |
329 | ||
330 | tcf_exts_change(tp, &cr.exts, &e); | |
331 | ||
332 | tcf_tree_lock(tp); | |
333 | if (old_r && old_r != r) | |
334 | memset(old_r, 0, sizeof(*old_r)); | |
335 | ||
336 | memcpy(p, &cp, sizeof(cp)); | |
337 | memcpy(r, &cr, sizeof(cr)); | |
338 | ||
339 | if (r == &new_filter_result) { | |
340 | struct tcindex_filter **fp; | |
341 | ||
342 | f->key = handle; | |
343 | f->result = new_filter_result; | |
344 | f->next = NULL; | |
345 | for (fp = p->h+(handle % p->hash); *fp; fp = &(*fp)->next) | |
346 | /* nothing */; | |
347 | *fp = f; | |
348 | } | |
349 | tcf_tree_unlock(tp); | |
350 | ||
351 | return 0; | |
352 | ||
353 | errout_alloc: | |
354 | if (balloc == 1) | |
355 | kfree(cp.perfect); | |
356 | else if (balloc == 2) | |
357 | kfree(cp.h); | |
358 | errout: | |
359 | tcf_exts_destroy(tp, &e); | |
360 | return err; | |
361 | } | |
362 | ||
363 | static int | |
364 | tcindex_change(struct tcf_proto *tp, unsigned long base, u32 handle, | |
365 | struct rtattr **tca, unsigned long *arg) | |
366 | { | |
367 | struct rtattr *opt = tca[TCA_OPTIONS-1]; | |
368 | struct rtattr *tb[TCA_TCINDEX_MAX]; | |
369 | struct tcindex_data *p = PRIV(tp); | |
370 | struct tcindex_filter_result *r = (struct tcindex_filter_result *) *arg; | |
371 | ||
372 | DPRINTK("tcindex_change(tp %p,handle 0x%08x,tca %p,arg %p),opt %p," | |
373 | "p %p,r %p,*arg 0x%lx\n", | |
374 | tp, handle, tca, arg, opt, p, r, arg ? *arg : 0L); | |
375 | ||
376 | if (!opt) | |
377 | return 0; | |
378 | ||
379 | if (rtattr_parse_nested(tb, TCA_TCINDEX_MAX, opt) < 0) | |
380 | return -EINVAL; | |
381 | ||
382 | return tcindex_set_parms(tp, base, handle, p, r, tb, tca[TCA_RATE-1]); | |
383 | } | |
384 | ||
385 | ||
386 | static void tcindex_walk(struct tcf_proto *tp, struct tcf_walker *walker) | |
387 | { | |
388 | struct tcindex_data *p = PRIV(tp); | |
389 | struct tcindex_filter *f,*next; | |
390 | int i; | |
391 | ||
392 | DPRINTK("tcindex_walk(tp %p,walker %p),p %p\n",tp,walker,p); | |
393 | if (p->perfect) { | |
394 | for (i = 0; i < p->hash; i++) { | |
395 | if (!p->perfect[i].res.class) | |
396 | continue; | |
397 | if (walker->count >= walker->skip) { | |
398 | if (walker->fn(tp, | |
399 | (unsigned long) (p->perfect+i), walker) | |
400 | < 0) { | |
401 | walker->stop = 1; | |
402 | return; | |
403 | } | |
404 | } | |
405 | walker->count++; | |
406 | } | |
407 | } | |
408 | if (!p->h) | |
409 | return; | |
410 | for (i = 0; i < p->hash; i++) { | |
411 | for (f = p->h[i]; f; f = next) { | |
412 | next = f->next; | |
413 | if (walker->count >= walker->skip) { | |
414 | if (walker->fn(tp,(unsigned long) &f->result, | |
415 | walker) < 0) { | |
416 | walker->stop = 1; | |
417 | return; | |
418 | } | |
419 | } | |
420 | walker->count++; | |
421 | } | |
422 | } | |
423 | } | |
424 | ||
425 | ||
426 | static int tcindex_destroy_element(struct tcf_proto *tp, | |
427 | unsigned long arg, struct tcf_walker *walker) | |
428 | { | |
429 | return __tcindex_delete(tp, arg, 0); | |
430 | } | |
431 | ||
432 | ||
433 | static void tcindex_destroy(struct tcf_proto *tp) | |
434 | { | |
435 | struct tcindex_data *p = PRIV(tp); | |
436 | struct tcf_walker walker; | |
437 | ||
438 | DPRINTK("tcindex_destroy(tp %p),p %p\n",tp,p); | |
439 | walker.count = 0; | |
440 | walker.skip = 0; | |
441 | walker.fn = &tcindex_destroy_element; | |
442 | tcindex_walk(tp,&walker); | |
a51482bd JJ |
443 | kfree(p->perfect); |
444 | kfree(p->h); | |
1da177e4 LT |
445 | kfree(p); |
446 | tp->root = NULL; | |
447 | } | |
448 | ||
449 | ||
450 | static int tcindex_dump(struct tcf_proto *tp, unsigned long fh, | |
451 | struct sk_buff *skb, struct tcmsg *t) | |
452 | { | |
453 | struct tcindex_data *p = PRIV(tp); | |
454 | struct tcindex_filter_result *r = (struct tcindex_filter_result *) fh; | |
455 | unsigned char *b = skb->tail; | |
456 | struct rtattr *rta; | |
457 | ||
458 | DPRINTK("tcindex_dump(tp %p,fh 0x%lx,skb %p,t %p),p %p,r %p,b %p\n", | |
459 | tp,fh,skb,t,p,r,b); | |
460 | DPRINTK("p->perfect %p p->h %p\n",p->perfect,p->h); | |
461 | rta = (struct rtattr *) b; | |
462 | RTA_PUT(skb,TCA_OPTIONS,0,NULL); | |
463 | if (!fh) { | |
464 | t->tcm_handle = ~0; /* whatever ... */ | |
465 | RTA_PUT(skb,TCA_TCINDEX_HASH,sizeof(p->hash),&p->hash); | |
466 | RTA_PUT(skb,TCA_TCINDEX_MASK,sizeof(p->mask),&p->mask); | |
467 | RTA_PUT(skb,TCA_TCINDEX_SHIFT,sizeof(p->shift),&p->shift); | |
468 | RTA_PUT(skb,TCA_TCINDEX_FALL_THROUGH,sizeof(p->fall_through), | |
469 | &p->fall_through); | |
470 | rta->rta_len = skb->tail-b; | |
471 | } else { | |
472 | if (p->perfect) { | |
473 | t->tcm_handle = r-p->perfect; | |
474 | } else { | |
475 | struct tcindex_filter *f; | |
476 | int i; | |
477 | ||
478 | t->tcm_handle = 0; | |
479 | for (i = 0; !t->tcm_handle && i < p->hash; i++) { | |
480 | for (f = p->h[i]; !t->tcm_handle && f; | |
481 | f = f->next) { | |
482 | if (&f->result == r) | |
483 | t->tcm_handle = f->key; | |
484 | } | |
485 | } | |
486 | } | |
487 | DPRINTK("handle = %d\n",t->tcm_handle); | |
488 | if (r->res.class) | |
489 | RTA_PUT(skb, TCA_TCINDEX_CLASSID, 4, &r->res.classid); | |
490 | ||
491 | if (tcf_exts_dump(skb, &r->exts, &tcindex_ext_map) < 0) | |
492 | goto rtattr_failure; | |
493 | rta->rta_len = skb->tail-b; | |
494 | ||
495 | if (tcf_exts_dump_stats(skb, &r->exts, &tcindex_ext_map) < 0) | |
496 | goto rtattr_failure; | |
497 | } | |
498 | ||
499 | return skb->len; | |
500 | ||
501 | rtattr_failure: | |
502 | skb_trim(skb, b - skb->data); | |
503 | return -1; | |
504 | } | |
505 | ||
506 | static struct tcf_proto_ops cls_tcindex_ops = { | |
507 | .next = NULL, | |
508 | .kind = "tcindex", | |
509 | .classify = tcindex_classify, | |
510 | .init = tcindex_init, | |
511 | .destroy = tcindex_destroy, | |
512 | .get = tcindex_get, | |
513 | .put = tcindex_put, | |
514 | .change = tcindex_change, | |
515 | .delete = tcindex_delete, | |
516 | .walk = tcindex_walk, | |
517 | .dump = tcindex_dump, | |
518 | .owner = THIS_MODULE, | |
519 | }; | |
520 | ||
521 | static int __init init_tcindex(void) | |
522 | { | |
523 | return register_tcf_proto_ops(&cls_tcindex_ops); | |
524 | } | |
525 | ||
526 | static void __exit exit_tcindex(void) | |
527 | { | |
528 | unregister_tcf_proto_ops(&cls_tcindex_ops); | |
529 | } | |
530 | ||
531 | module_init(init_tcindex) | |
532 | module_exit(exit_tcindex) | |
533 | MODULE_LICENSE("GPL"); |