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Merge branches 'armv7', 'at91', 'misc' and 'omap' into devel
[linux-2.6-omap-h63xx.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 <linux/netdevice.h>
13 #include <net/ip.h>
14 #include <net/act_api.h>
15 #include <net/netlink.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 = kzalloc(sizeof(struct tcindex_data),GFP_KERNEL);
153         if (!p)
154                 return -ENOMEM;
155
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);
196         kfree(f);
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(int))
250                         goto errout;
251                 cp.shift = *(int *) 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 = kcalloc(cp.hash, sizeof(*r), GFP_KERNEL);
300                         if (!cp.perfect)
301                                 goto errout;
302                         balloc = 1;
303                 } else {
304                         cp.h = kcalloc(cp.hash, sizeof(f), GFP_KERNEL);
305                         if (!cp.h)
306                                 goto errout;
307                         balloc = 2;
308                 }
309         }
310
311         if (cp.perfect)
312                 r = cp.perfect + handle;
313         else
314                 r = tcindex_lookup(&cp, handle) ? : &new_filter_result;
315
316         if (r == &new_filter_result) {
317                 f = kzalloc(sizeof(*f), GFP_KERNEL);
318                 if (!f)
319                         goto errout_alloc;
320         }
321
322         if (tb[TCA_TCINDEX_CLASSID-1]) {
323                 cr.res.classid = *(u32 *) RTA_DATA(tb[TCA_TCINDEX_CLASSID-1]);
324                 tcf_bind_filter(tp, &cr.res, base);
325         }
326
327         tcf_exts_change(tp, &cr.exts, &e);
328
329         tcf_tree_lock(tp);
330         if (old_r && old_r != r)
331                 memset(old_r, 0, sizeof(*old_r));
332
333         memcpy(p, &cp, sizeof(cp));
334         memcpy(r, &cr, sizeof(cr));
335
336         if (r == &new_filter_result) {
337                 struct tcindex_filter **fp;
338
339                 f->key = handle;
340                 f->result = new_filter_result;
341                 f->next = NULL;
342                 for (fp = p->h+(handle % p->hash); *fp; fp = &(*fp)->next)
343                         /* nothing */;
344                 *fp = f;
345         }
346         tcf_tree_unlock(tp);
347
348         return 0;
349
350 errout_alloc:
351         if (balloc == 1)
352                 kfree(cp.perfect);
353         else if (balloc == 2)
354                 kfree(cp.h);
355 errout:
356         tcf_exts_destroy(tp, &e);
357         return err;
358 }
359
360 static int
361 tcindex_change(struct tcf_proto *tp, unsigned long base, u32 handle,
362                struct rtattr **tca, unsigned long *arg)
363 {
364         struct rtattr *opt = tca[TCA_OPTIONS-1];
365         struct rtattr *tb[TCA_TCINDEX_MAX];
366         struct tcindex_data *p = PRIV(tp);
367         struct tcindex_filter_result *r = (struct tcindex_filter_result *) *arg;
368
369         DPRINTK("tcindex_change(tp %p,handle 0x%08x,tca %p,arg %p),opt %p,"
370             "p %p,r %p,*arg 0x%lx\n",
371             tp, handle, tca, arg, opt, p, r, arg ? *arg : 0L);
372
373         if (!opt)
374                 return 0;
375
376         if (rtattr_parse_nested(tb, TCA_TCINDEX_MAX, opt) < 0)
377                 return -EINVAL;
378
379         return tcindex_set_parms(tp, base, handle, p, r, tb, tca[TCA_RATE-1]);
380 }
381
382
383 static void tcindex_walk(struct tcf_proto *tp, struct tcf_walker *walker)
384 {
385         struct tcindex_data *p = PRIV(tp);
386         struct tcindex_filter *f,*next;
387         int i;
388
389         DPRINTK("tcindex_walk(tp %p,walker %p),p %p\n",tp,walker,p);
390         if (p->perfect) {
391                 for (i = 0; i < p->hash; i++) {
392                         if (!p->perfect[i].res.class)
393                                 continue;
394                         if (walker->count >= walker->skip) {
395                                 if (walker->fn(tp,
396                                     (unsigned long) (p->perfect+i), walker)
397                                      < 0) {
398                                         walker->stop = 1;
399                                         return;
400                                 }
401                         }
402                         walker->count++;
403                 }
404         }
405         if (!p->h)
406                 return;
407         for (i = 0; i < p->hash; i++) {
408                 for (f = p->h[i]; f; f = next) {
409                         next = f->next;
410                         if (walker->count >= walker->skip) {
411                                 if (walker->fn(tp,(unsigned long) &f->result,
412                                     walker) < 0) {
413                                         walker->stop = 1;
414                                         return;
415                                 }
416                         }
417                         walker->count++;
418                 }
419         }
420 }
421
422
423 static int tcindex_destroy_element(struct tcf_proto *tp,
424     unsigned long arg, struct tcf_walker *walker)
425 {
426         return __tcindex_delete(tp, arg, 0);
427 }
428
429
430 static void tcindex_destroy(struct tcf_proto *tp)
431 {
432         struct tcindex_data *p = PRIV(tp);
433         struct tcf_walker walker;
434
435         DPRINTK("tcindex_destroy(tp %p),p %p\n",tp,p);
436         walker.count = 0;
437         walker.skip = 0;
438         walker.fn = &tcindex_destroy_element;
439         tcindex_walk(tp,&walker);
440         kfree(p->perfect);
441         kfree(p->h);
442         kfree(p);
443         tp->root = NULL;
444 }
445
446
447 static int tcindex_dump(struct tcf_proto *tp, unsigned long fh,
448     struct sk_buff *skb, struct tcmsg *t)
449 {
450         struct tcindex_data *p = PRIV(tp);
451         struct tcindex_filter_result *r = (struct tcindex_filter_result *) fh;
452         unsigned char *b = skb_tail_pointer(skb);
453         struct rtattr *rta;
454
455         DPRINTK("tcindex_dump(tp %p,fh 0x%lx,skb %p,t %p),p %p,r %p,b %p\n",
456             tp,fh,skb,t,p,r,b);
457         DPRINTK("p->perfect %p p->h %p\n",p->perfect,p->h);
458         rta = (struct rtattr *) b;
459         RTA_PUT(skb,TCA_OPTIONS,0,NULL);
460         if (!fh) {
461                 t->tcm_handle = ~0; /* whatever ... */
462                 RTA_PUT(skb,TCA_TCINDEX_HASH,sizeof(p->hash),&p->hash);
463                 RTA_PUT(skb,TCA_TCINDEX_MASK,sizeof(p->mask),&p->mask);
464                 RTA_PUT(skb,TCA_TCINDEX_SHIFT,sizeof(p->shift),&p->shift);
465                 RTA_PUT(skb,TCA_TCINDEX_FALL_THROUGH,sizeof(p->fall_through),
466                     &p->fall_through);
467                 rta->rta_len = skb_tail_pointer(skb) - b;
468         } else {
469                 if (p->perfect) {
470                         t->tcm_handle = r-p->perfect;
471                 } else {
472                         struct tcindex_filter *f;
473                         int i;
474
475                         t->tcm_handle = 0;
476                         for (i = 0; !t->tcm_handle && i < p->hash; i++) {
477                                 for (f = p->h[i]; !t->tcm_handle && f;
478                                      f = f->next) {
479                                         if (&f->result == r)
480                                                 t->tcm_handle = f->key;
481                                 }
482                         }
483                 }
484                 DPRINTK("handle = %d\n",t->tcm_handle);
485                 if (r->res.class)
486                         RTA_PUT(skb, TCA_TCINDEX_CLASSID, 4, &r->res.classid);
487
488                 if (tcf_exts_dump(skb, &r->exts, &tcindex_ext_map) < 0)
489                         goto rtattr_failure;
490                 rta->rta_len = skb_tail_pointer(skb) - b;
491
492                 if (tcf_exts_dump_stats(skb, &r->exts, &tcindex_ext_map) < 0)
493                         goto rtattr_failure;
494         }
495
496         return skb->len;
497
498 rtattr_failure:
499         nlmsg_trim(skb, b);
500         return -1;
501 }
502
503 static struct tcf_proto_ops cls_tcindex_ops = {
504         .next           =       NULL,
505         .kind           =       "tcindex",
506         .classify       =       tcindex_classify,
507         .init           =       tcindex_init,
508         .destroy        =       tcindex_destroy,
509         .get            =       tcindex_get,
510         .put            =       tcindex_put,
511         .change         =       tcindex_change,
512         .delete         =       tcindex_delete,
513         .walk           =       tcindex_walk,
514         .dump           =       tcindex_dump,
515         .owner          =       THIS_MODULE,
516 };
517
518 static int __init init_tcindex(void)
519 {
520         return register_tcf_proto_ops(&cls_tcindex_ops);
521 }
522
523 static void __exit exit_tcindex(void)
524 {
525         unregister_tcf_proto_ops(&cls_tcindex_ops);
526 }
527
528 module_init(init_tcindex)
529 module_exit(exit_tcindex)
530 MODULE_LICENSE("GPL");