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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 | ||
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> | |
1da177e4 | 12 | #include <net/act_api.h> |
dc5fc579 | 13 | #include <net/netlink.h> |
1da177e4 | 14 | #include <net/pkt_cls.h> |
1da177e4 LT |
15 | |
16 | ||
17 | /* | |
18 | * Not quite sure if we need all the xchgs Alexey uses when accessing things. | |
19 | * Can always add them later ... :) | |
20 | */ | |
21 | ||
22 | /* | |
23 | * Passing parameters to the root seems to be done more awkwardly than really | |
24 | * necessary. At least, u32 doesn't seem to use such dirty hacks. To be | |
25 | * verified. FIXME. | |
26 | */ | |
27 | ||
28 | #define PERFECT_HASH_THRESHOLD 64 /* use perfect hash if not bigger */ | |
29 | #define DEFAULT_HASH_SIZE 64 /* optimized for diffserv */ | |
30 | ||
31 | ||
1da177e4 LT |
32 | #define PRIV(tp) ((struct tcindex_data *) (tp)->root) |
33 | ||
34 | ||
35 | struct tcindex_filter_result { | |
36 | struct tcf_exts exts; | |
37 | struct tcf_result res; | |
38 | }; | |
39 | ||
40 | struct tcindex_filter { | |
41 | u16 key; | |
42 | struct tcindex_filter_result result; | |
43 | struct tcindex_filter *next; | |
44 | }; | |
45 | ||
46 | ||
47 | struct tcindex_data { | |
48 | struct tcindex_filter_result *perfect; /* perfect hash; NULL if none */ | |
49 | struct tcindex_filter **h; /* imperfect hash; only used if !perfect; | |
50 | NULL if unused */ | |
51 | u16 mask; /* AND key with mask */ | |
52 | int shift; /* shift ANDed key to the right */ | |
53 | int hash; /* hash table size; 0 if undefined */ | |
54 | int alloc_hash; /* allocated size */ | |
55 | int fall_through; /* 0: only classify if explicit match */ | |
56 | }; | |
57 | ||
58 | static struct tcf_ext_map tcindex_ext_map = { | |
59 | .police = TCA_TCINDEX_POLICE, | |
60 | .action = TCA_TCINDEX_ACT | |
61 | }; | |
62 | ||
63 | static inline int | |
64 | tcindex_filter_is_set(struct tcindex_filter_result *r) | |
65 | { | |
66 | return tcf_exts_is_predicative(&r->exts) || r->res.classid; | |
67 | } | |
68 | ||
69 | static struct tcindex_filter_result * | |
70 | tcindex_lookup(struct tcindex_data *p, u16 key) | |
71 | { | |
72 | struct tcindex_filter *f; | |
73 | ||
74 | if (p->perfect) | |
75 | return tcindex_filter_is_set(p->perfect + key) ? | |
76 | p->perfect + key : NULL; | |
77 | else if (p->h) { | |
78 | for (f = p->h[key % p->hash]; f; f = f->next) | |
79 | if (f->key == key) | |
80 | return &f->result; | |
81 | } | |
82 | ||
83 | return NULL; | |
84 | } | |
85 | ||
86 | ||
87 | static int tcindex_classify(struct sk_buff *skb, struct tcf_proto *tp, | |
88 | struct tcf_result *res) | |
89 | { | |
90 | struct tcindex_data *p = PRIV(tp); | |
91 | struct tcindex_filter_result *f; | |
92 | int key = (skb->tc_index & p->mask) >> p->shift; | |
93 | ||
aa767bfe SH |
94 | pr_debug("tcindex_classify(skb %p,tp %p,res %p),p %p\n", |
95 | skb, tp, res, p); | |
1da177e4 LT |
96 | |
97 | f = tcindex_lookup(p, key); | |
98 | if (!f) { | |
99 | if (!p->fall_through) | |
100 | return -1; | |
101 | res->classid = TC_H_MAKE(TC_H_MAJ(tp->q->handle), key); | |
102 | res->class = 0; | |
aa767bfe | 103 | pr_debug("alg 0x%x\n", res->classid); |
1da177e4 LT |
104 | return 0; |
105 | } | |
106 | *res = f->res; | |
aa767bfe | 107 | pr_debug("map 0x%x\n", res->classid); |
1da177e4 LT |
108 | |
109 | return tcf_exts_exec(skb, &f->exts, res); | |
110 | } | |
111 | ||
112 | ||
113 | static unsigned long tcindex_get(struct tcf_proto *tp, u32 handle) | |
114 | { | |
115 | struct tcindex_data *p = PRIV(tp); | |
116 | struct tcindex_filter_result *r; | |
117 | ||
aa767bfe | 118 | pr_debug("tcindex_get(tp %p,handle 0x%08x)\n", tp, handle); |
1da177e4 LT |
119 | if (p->perfect && handle >= p->alloc_hash) |
120 | return 0; | |
121 | r = tcindex_lookup(p, handle); | |
122 | return r && tcindex_filter_is_set(r) ? (unsigned long) r : 0UL; | |
123 | } | |
124 | ||
125 | ||
126 | static void tcindex_put(struct tcf_proto *tp, unsigned long f) | |
127 | { | |
aa767bfe | 128 | pr_debug("tcindex_put(tp %p,f 0x%lx)\n", tp, f); |
1da177e4 LT |
129 | } |
130 | ||
131 | ||
132 | static int tcindex_init(struct tcf_proto *tp) | |
133 | { | |
134 | struct tcindex_data *p; | |
135 | ||
aa767bfe SH |
136 | pr_debug("tcindex_init(tp %p)\n", tp); |
137 | p = kzalloc(sizeof(struct tcindex_data), GFP_KERNEL); | |
1da177e4 LT |
138 | if (!p) |
139 | return -ENOMEM; | |
140 | ||
1da177e4 LT |
141 | p->mask = 0xffff; |
142 | p->hash = DEFAULT_HASH_SIZE; | |
143 | p->fall_through = 1; | |
144 | ||
145 | tp->root = p; | |
146 | return 0; | |
147 | } | |
148 | ||
149 | ||
150 | static int | |
151 | __tcindex_delete(struct tcf_proto *tp, unsigned long arg, int lock) | |
152 | { | |
153 | struct tcindex_data *p = PRIV(tp); | |
154 | struct tcindex_filter_result *r = (struct tcindex_filter_result *) arg; | |
155 | struct tcindex_filter *f = NULL; | |
156 | ||
aa767bfe | 157 | pr_debug("tcindex_delete(tp %p,arg 0x%lx),p %p,f %p\n", tp, arg, p, f); |
1da177e4 LT |
158 | if (p->perfect) { |
159 | if (!r->res.class) | |
160 | return -ENOENT; | |
161 | } else { | |
162 | int i; | |
163 | struct tcindex_filter **walk = NULL; | |
164 | ||
165 | for (i = 0; i < p->hash; i++) | |
166 | for (walk = p->h+i; *walk; walk = &(*walk)->next) | |
167 | if (&(*walk)->result == r) | |
168 | goto found; | |
169 | return -ENOENT; | |
170 | ||
171 | found: | |
172 | f = *walk; | |
173 | if (lock) | |
174 | tcf_tree_lock(tp); | |
175 | *walk = f->next; | |
176 | if (lock) | |
177 | tcf_tree_unlock(tp); | |
178 | } | |
179 | tcf_unbind_filter(tp, &r->res); | |
180 | tcf_exts_destroy(tp, &r->exts); | |
a51482bd | 181 | kfree(f); |
1da177e4 LT |
182 | return 0; |
183 | } | |
184 | ||
185 | static int tcindex_delete(struct tcf_proto *tp, unsigned long arg) | |
186 | { | |
187 | return __tcindex_delete(tp, arg, 1); | |
188 | } | |
189 | ||
190 | static inline int | |
191 | valid_perfect_hash(struct tcindex_data *p) | |
192 | { | |
193 | return p->hash > (p->mask >> p->shift); | |
194 | } | |
195 | ||
6fa8c014 PM |
196 | static const struct nla_policy tcindex_policy[TCA_TCINDEX_MAX + 1] = { |
197 | [TCA_TCINDEX_HASH] = { .type = NLA_U32 }, | |
198 | [TCA_TCINDEX_MASK] = { .type = NLA_U16 }, | |
199 | [TCA_TCINDEX_SHIFT] = { .type = NLA_U32 }, | |
200 | [TCA_TCINDEX_FALL_THROUGH] = { .type = NLA_U32 }, | |
201 | [TCA_TCINDEX_CLASSID] = { .type = NLA_U32 }, | |
202 | }; | |
203 | ||
1da177e4 LT |
204 | static int |
205 | tcindex_set_parms(struct tcf_proto *tp, unsigned long base, u32 handle, | |
206 | struct tcindex_data *p, struct tcindex_filter_result *r, | |
add93b61 | 207 | struct nlattr **tb, struct nlattr *est) |
1da177e4 LT |
208 | { |
209 | int err, balloc = 0; | |
210 | struct tcindex_filter_result new_filter_result, *old_r = r; | |
211 | struct tcindex_filter_result cr; | |
212 | struct tcindex_data cp; | |
213 | struct tcindex_filter *f = NULL; /* make gcc behave */ | |
214 | struct tcf_exts e; | |
215 | ||
216 | err = tcf_exts_validate(tp, tb, est, &e, &tcindex_ext_map); | |
217 | if (err < 0) | |
218 | return err; | |
10297b99 | 219 | |
1da177e4 LT |
220 | memcpy(&cp, p, sizeof(cp)); |
221 | memset(&new_filter_result, 0, sizeof(new_filter_result)); | |
222 | ||
223 | if (old_r) | |
224 | memcpy(&cr, r, sizeof(cr)); | |
225 | else | |
226 | memset(&cr, 0, sizeof(cr)); | |
227 | ||
6fa8c014 | 228 | if (tb[TCA_TCINDEX_HASH]) |
1587bac4 | 229 | cp.hash = nla_get_u32(tb[TCA_TCINDEX_HASH]); |
1da177e4 | 230 | |
6fa8c014 | 231 | if (tb[TCA_TCINDEX_MASK]) |
1587bac4 | 232 | cp.mask = nla_get_u16(tb[TCA_TCINDEX_MASK]); |
1da177e4 | 233 | |
6fa8c014 | 234 | if (tb[TCA_TCINDEX_SHIFT]) |
1587bac4 | 235 | cp.shift = nla_get_u32(tb[TCA_TCINDEX_SHIFT]); |
1da177e4 LT |
236 | |
237 | err = -EBUSY; | |
238 | /* Hash already allocated, make sure that we still meet the | |
239 | * requirements for the allocated hash. | |
240 | */ | |
241 | if (cp.perfect) { | |
242 | if (!valid_perfect_hash(&cp) || | |
243 | cp.hash > cp.alloc_hash) | |
244 | goto errout; | |
245 | } else if (cp.h && cp.hash != cp.alloc_hash) | |
246 | goto errout; | |
247 | ||
248 | err = -EINVAL; | |
6fa8c014 | 249 | if (tb[TCA_TCINDEX_FALL_THROUGH]) |
1587bac4 | 250 | cp.fall_through = nla_get_u32(tb[TCA_TCINDEX_FALL_THROUGH]); |
1da177e4 LT |
251 | |
252 | if (!cp.hash) { | |
253 | /* Hash not specified, use perfect hash if the upper limit | |
254 | * of the hashing index is below the threshold. | |
255 | */ | |
256 | if ((cp.mask >> cp.shift) < PERFECT_HASH_THRESHOLD) | |
257 | cp.hash = (cp.mask >> cp.shift)+1; | |
258 | else | |
259 | cp.hash = DEFAULT_HASH_SIZE; | |
260 | } | |
261 | ||
262 | if (!cp.perfect && !cp.h) | |
263 | cp.alloc_hash = cp.hash; | |
264 | ||
265 | /* Note: this could be as restrictive as if (handle & ~(mask >> shift)) | |
266 | * but then, we'd fail handles that may become valid after some future | |
267 | * mask change. While this is extremely unlikely to ever matter, | |
268 | * the check below is safer (and also more backwards-compatible). | |
269 | */ | |
270 | if (cp.perfect || valid_perfect_hash(&cp)) | |
271 | if (handle >= cp.alloc_hash) | |
272 | goto errout; | |
273 | ||
274 | ||
275 | err = -ENOMEM; | |
276 | if (!cp.perfect && !cp.h) { | |
277 | if (valid_perfect_hash(&cp)) { | |
0da974f4 | 278 | cp.perfect = kcalloc(cp.hash, sizeof(*r), GFP_KERNEL); |
1da177e4 LT |
279 | if (!cp.perfect) |
280 | goto errout; | |
1da177e4 LT |
281 | balloc = 1; |
282 | } else { | |
0da974f4 | 283 | cp.h = kcalloc(cp.hash, sizeof(f), GFP_KERNEL); |
1da177e4 LT |
284 | if (!cp.h) |
285 | goto errout; | |
1da177e4 LT |
286 | balloc = 2; |
287 | } | |
288 | } | |
289 | ||
290 | if (cp.perfect) | |
291 | r = cp.perfect + handle; | |
292 | else | |
293 | r = tcindex_lookup(&cp, handle) ? : &new_filter_result; | |
294 | ||
295 | if (r == &new_filter_result) { | |
0da974f4 | 296 | f = kzalloc(sizeof(*f), GFP_KERNEL); |
1da177e4 LT |
297 | if (!f) |
298 | goto errout_alloc; | |
10297b99 | 299 | } |
1da177e4 | 300 | |
add93b61 | 301 | if (tb[TCA_TCINDEX_CLASSID]) { |
1587bac4 | 302 | cr.res.classid = nla_get_u32(tb[TCA_TCINDEX_CLASSID]); |
1da177e4 | 303 | tcf_bind_filter(tp, &cr.res, base); |
10297b99 | 304 | } |
1da177e4 LT |
305 | |
306 | tcf_exts_change(tp, &cr.exts, &e); | |
307 | ||
308 | tcf_tree_lock(tp); | |
309 | if (old_r && old_r != r) | |
310 | memset(old_r, 0, sizeof(*old_r)); | |
311 | ||
312 | memcpy(p, &cp, sizeof(cp)); | |
313 | memcpy(r, &cr, sizeof(cr)); | |
314 | ||
315 | if (r == &new_filter_result) { | |
316 | struct tcindex_filter **fp; | |
317 | ||
318 | f->key = handle; | |
319 | f->result = new_filter_result; | |
320 | f->next = NULL; | |
321 | for (fp = p->h+(handle % p->hash); *fp; fp = &(*fp)->next) | |
322 | /* nothing */; | |
323 | *fp = f; | |
10297b99 | 324 | } |
1da177e4 LT |
325 | tcf_tree_unlock(tp); |
326 | ||
327 | return 0; | |
328 | ||
329 | errout_alloc: | |
330 | if (balloc == 1) | |
331 | kfree(cp.perfect); | |
332 | else if (balloc == 2) | |
333 | kfree(cp.h); | |
334 | errout: | |
335 | tcf_exts_destroy(tp, &e); | |
336 | return err; | |
337 | } | |
338 | ||
339 | static int | |
340 | tcindex_change(struct tcf_proto *tp, unsigned long base, u32 handle, | |
add93b61 | 341 | struct nlattr **tca, unsigned long *arg) |
1da177e4 | 342 | { |
add93b61 PM |
343 | struct nlattr *opt = tca[TCA_OPTIONS]; |
344 | struct nlattr *tb[TCA_TCINDEX_MAX + 1]; | |
1da177e4 LT |
345 | struct tcindex_data *p = PRIV(tp); |
346 | struct tcindex_filter_result *r = (struct tcindex_filter_result *) *arg; | |
cee63723 | 347 | int err; |
1da177e4 | 348 | |
aa767bfe | 349 | pr_debug("tcindex_change(tp %p,handle 0x%08x,tca %p,arg %p),opt %p," |
1da177e4 LT |
350 | "p %p,r %p,*arg 0x%lx\n", |
351 | tp, handle, tca, arg, opt, p, r, arg ? *arg : 0L); | |
352 | ||
353 | if (!opt) | |
354 | return 0; | |
355 | ||
6fa8c014 | 356 | err = nla_parse_nested(tb, TCA_TCINDEX_MAX, opt, tcindex_policy); |
cee63723 PM |
357 | if (err < 0) |
358 | return err; | |
1da177e4 | 359 | |
add93b61 | 360 | return tcindex_set_parms(tp, base, handle, p, r, tb, tca[TCA_RATE]); |
1da177e4 LT |
361 | } |
362 | ||
363 | ||
364 | static void tcindex_walk(struct tcf_proto *tp, struct tcf_walker *walker) | |
365 | { | |
366 | struct tcindex_data *p = PRIV(tp); | |
aa767bfe | 367 | struct tcindex_filter *f, *next; |
1da177e4 LT |
368 | int i; |
369 | ||
aa767bfe | 370 | pr_debug("tcindex_walk(tp %p,walker %p),p %p\n", tp, walker, p); |
1da177e4 LT |
371 | if (p->perfect) { |
372 | for (i = 0; i < p->hash; i++) { | |
373 | if (!p->perfect[i].res.class) | |
374 | continue; | |
375 | if (walker->count >= walker->skip) { | |
376 | if (walker->fn(tp, | |
377 | (unsigned long) (p->perfect+i), walker) | |
378 | < 0) { | |
379 | walker->stop = 1; | |
380 | return; | |
381 | } | |
382 | } | |
383 | walker->count++; | |
384 | } | |
385 | } | |
386 | if (!p->h) | |
387 | return; | |
388 | for (i = 0; i < p->hash; i++) { | |
389 | for (f = p->h[i]; f; f = next) { | |
390 | next = f->next; | |
391 | if (walker->count >= walker->skip) { | |
aa767bfe | 392 | if (walker->fn(tp, (unsigned long) &f->result, |
1da177e4 LT |
393 | walker) < 0) { |
394 | walker->stop = 1; | |
395 | return; | |
396 | } | |
397 | } | |
398 | walker->count++; | |
399 | } | |
400 | } | |
401 | } | |
402 | ||
403 | ||
404 | static int tcindex_destroy_element(struct tcf_proto *tp, | |
405 | unsigned long arg, struct tcf_walker *walker) | |
406 | { | |
407 | return __tcindex_delete(tp, arg, 0); | |
408 | } | |
409 | ||
410 | ||
411 | static void tcindex_destroy(struct tcf_proto *tp) | |
412 | { | |
413 | struct tcindex_data *p = PRIV(tp); | |
414 | struct tcf_walker walker; | |
415 | ||
aa767bfe | 416 | pr_debug("tcindex_destroy(tp %p),p %p\n", tp, p); |
1da177e4 LT |
417 | walker.count = 0; |
418 | walker.skip = 0; | |
419 | walker.fn = &tcindex_destroy_element; | |
aa767bfe | 420 | tcindex_walk(tp, &walker); |
a51482bd JJ |
421 | kfree(p->perfect); |
422 | kfree(p->h); | |
1da177e4 LT |
423 | kfree(p); |
424 | tp->root = NULL; | |
425 | } | |
426 | ||
427 | ||
428 | static int tcindex_dump(struct tcf_proto *tp, unsigned long fh, | |
429 | struct sk_buff *skb, struct tcmsg *t) | |
430 | { | |
431 | struct tcindex_data *p = PRIV(tp); | |
432 | struct tcindex_filter_result *r = (struct tcindex_filter_result *) fh; | |
27a884dc | 433 | unsigned char *b = skb_tail_pointer(skb); |
4b3550ef | 434 | struct nlattr *nest; |
1da177e4 | 435 | |
aa767bfe SH |
436 | pr_debug("tcindex_dump(tp %p,fh 0x%lx,skb %p,t %p),p %p,r %p,b %p\n", |
437 | tp, fh, skb, t, p, r, b); | |
438 | pr_debug("p->perfect %p p->h %p\n", p->perfect, p->h); | |
4b3550ef PM |
439 | |
440 | nest = nla_nest_start(skb, TCA_OPTIONS); | |
441 | if (nest == NULL) | |
442 | goto nla_put_failure; | |
443 | ||
1da177e4 LT |
444 | if (!fh) { |
445 | t->tcm_handle = ~0; /* whatever ... */ | |
24beeab5 PM |
446 | NLA_PUT_U32(skb, TCA_TCINDEX_HASH, p->hash); |
447 | NLA_PUT_U16(skb, TCA_TCINDEX_MASK, p->mask); | |
448 | NLA_PUT_U32(skb, TCA_TCINDEX_SHIFT, p->shift); | |
449 | NLA_PUT_U32(skb, TCA_TCINDEX_FALL_THROUGH, p->fall_through); | |
4b3550ef | 450 | nla_nest_end(skb, nest); |
1da177e4 LT |
451 | } else { |
452 | if (p->perfect) { | |
453 | t->tcm_handle = r-p->perfect; | |
454 | } else { | |
455 | struct tcindex_filter *f; | |
456 | int i; | |
457 | ||
458 | t->tcm_handle = 0; | |
459 | for (i = 0; !t->tcm_handle && i < p->hash; i++) { | |
460 | for (f = p->h[i]; !t->tcm_handle && f; | |
461 | f = f->next) { | |
462 | if (&f->result == r) | |
463 | t->tcm_handle = f->key; | |
464 | } | |
465 | } | |
466 | } | |
aa767bfe | 467 | pr_debug("handle = %d\n", t->tcm_handle); |
1da177e4 | 468 | if (r->res.class) |
24beeab5 | 469 | NLA_PUT_U32(skb, TCA_TCINDEX_CLASSID, r->res.classid); |
1da177e4 LT |
470 | |
471 | if (tcf_exts_dump(skb, &r->exts, &tcindex_ext_map) < 0) | |
add93b61 | 472 | goto nla_put_failure; |
4b3550ef | 473 | nla_nest_end(skb, nest); |
1da177e4 LT |
474 | |
475 | if (tcf_exts_dump_stats(skb, &r->exts, &tcindex_ext_map) < 0) | |
add93b61 | 476 | goto nla_put_failure; |
1da177e4 | 477 | } |
10297b99 | 478 | |
1da177e4 LT |
479 | return skb->len; |
480 | ||
add93b61 | 481 | nla_put_failure: |
dc5fc579 | 482 | nlmsg_trim(skb, b); |
1da177e4 LT |
483 | return -1; |
484 | } | |
485 | ||
2eb9d75c | 486 | static struct tcf_proto_ops cls_tcindex_ops __read_mostly = { |
1da177e4 LT |
487 | .kind = "tcindex", |
488 | .classify = tcindex_classify, | |
489 | .init = tcindex_init, | |
490 | .destroy = tcindex_destroy, | |
491 | .get = tcindex_get, | |
492 | .put = tcindex_put, | |
493 | .change = tcindex_change, | |
494 | .delete = tcindex_delete, | |
495 | .walk = tcindex_walk, | |
496 | .dump = tcindex_dump, | |
497 | .owner = THIS_MODULE, | |
498 | }; | |
499 | ||
500 | static int __init init_tcindex(void) | |
501 | { | |
502 | return register_tcf_proto_ops(&cls_tcindex_ops); | |
503 | } | |
504 | ||
10297b99 | 505 | static void __exit exit_tcindex(void) |
1da177e4 LT |
506 | { |
507 | unregister_tcf_proto_ops(&cls_tcindex_ops); | |
508 | } | |
509 | ||
510 | module_init(init_tcindex) | |
511 | module_exit(exit_tcindex) | |
512 | MODULE_LICENSE("GPL"); |