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