Merge branch 'drm-patches' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied...
[linux-2.6] / 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/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 = kzalloc(sizeof(struct tcindex_data),GFP_KERNEL);
152         if (!p)
153                 return -ENOMEM;
154
155         p->mask = 0xffff;
156         p->hash = DEFAULT_HASH_SIZE;
157         p->fall_through = 1;
158
159         tp->root = p;
160         return 0;
161 }
162
163
164 static int
165 __tcindex_delete(struct tcf_proto *tp, unsigned long arg, int lock)
166 {
167         struct tcindex_data *p = PRIV(tp);
168         struct tcindex_filter_result *r = (struct tcindex_filter_result *) arg;
169         struct tcindex_filter *f = NULL;
170
171         DPRINTK("tcindex_delete(tp %p,arg 0x%lx),p %p,f %p\n",tp,arg,p,f);
172         if (p->perfect) {
173                 if (!r->res.class)
174                         return -ENOENT;
175         } else {
176                 int i;
177                 struct tcindex_filter **walk = NULL;
178
179                 for (i = 0; i < p->hash; i++)
180                         for (walk = p->h+i; *walk; walk = &(*walk)->next)
181                                 if (&(*walk)->result == r)
182                                         goto found;
183                 return -ENOENT;
184
185 found:
186                 f = *walk;
187                 if (lock)
188                         tcf_tree_lock(tp);
189                 *walk = f->next;
190                 if (lock)
191                         tcf_tree_unlock(tp);
192         }
193         tcf_unbind_filter(tp, &r->res);
194         tcf_exts_destroy(tp, &r->exts);
195         kfree(f);
196         return 0;
197 }
198
199 static int tcindex_delete(struct tcf_proto *tp, unsigned long arg)
200 {
201         return __tcindex_delete(tp, arg, 1);
202 }
203
204 static inline int
205 valid_perfect_hash(struct tcindex_data *p)
206 {
207         return  p->hash > (p->mask >> p->shift);
208 }
209
210 static int
211 tcindex_set_parms(struct tcf_proto *tp, unsigned long base, u32 handle,
212                   struct tcindex_data *p, struct tcindex_filter_result *r,
213                   struct rtattr **tb, struct rtattr *est)
214 {
215         int err, balloc = 0;
216         struct tcindex_filter_result new_filter_result, *old_r = r;
217         struct tcindex_filter_result cr;
218         struct tcindex_data cp;
219         struct tcindex_filter *f = NULL; /* make gcc behave */
220         struct tcf_exts e;
221
222         err = tcf_exts_validate(tp, tb, est, &e, &tcindex_ext_map);
223         if (err < 0)
224                 return err;
225         
226         memcpy(&cp, p, sizeof(cp));
227         memset(&new_filter_result, 0, sizeof(new_filter_result));
228
229         if (old_r)
230                 memcpy(&cr, r, sizeof(cr));
231         else
232                 memset(&cr, 0, sizeof(cr));
233
234         err = -EINVAL;
235         if (tb[TCA_TCINDEX_HASH-1]) {
236                 if (RTA_PAYLOAD(tb[TCA_TCINDEX_HASH-1]) < sizeof(u32))
237                         goto errout;
238                 cp.hash = *(u32 *) RTA_DATA(tb[TCA_TCINDEX_HASH-1]);
239         }
240
241         if (tb[TCA_TCINDEX_MASK-1]) {
242                 if (RTA_PAYLOAD(tb[TCA_TCINDEX_MASK-1]) < sizeof(u16))
243                         goto errout;
244                 cp.mask = *(u16 *) RTA_DATA(tb[TCA_TCINDEX_MASK-1]);
245         }
246
247         if (tb[TCA_TCINDEX_SHIFT-1]) {
248                 if (RTA_PAYLOAD(tb[TCA_TCINDEX_SHIFT-1]) < sizeof(u16))
249                         goto errout;
250                 cp.shift = *(u16 *) RTA_DATA(tb[TCA_TCINDEX_SHIFT-1]);
251         }
252
253         err = -EBUSY;
254         /* Hash already allocated, make sure that we still meet the
255          * requirements for the allocated hash.
256          */
257         if (cp.perfect) {
258                 if (!valid_perfect_hash(&cp) ||
259                     cp.hash > cp.alloc_hash)
260                         goto errout;
261         } else if (cp.h && cp.hash != cp.alloc_hash)
262                 goto errout;
263
264         err = -EINVAL;
265         if (tb[TCA_TCINDEX_FALL_THROUGH-1]) {
266                 if (RTA_PAYLOAD(tb[TCA_TCINDEX_FALL_THROUGH-1]) < sizeof(u32))
267                         goto errout;
268                 cp.fall_through =
269                         *(u32 *) RTA_DATA(tb[TCA_TCINDEX_FALL_THROUGH-1]);
270         }
271
272         if (!cp.hash) {
273                 /* Hash not specified, use perfect hash if the upper limit
274                  * of the hashing index is below the threshold.
275                  */
276                 if ((cp.mask >> cp.shift) < PERFECT_HASH_THRESHOLD)
277                         cp.hash = (cp.mask >> cp.shift)+1;
278                 else
279                         cp.hash = DEFAULT_HASH_SIZE;
280         }
281
282         if (!cp.perfect && !cp.h)
283                 cp.alloc_hash = cp.hash;
284
285         /* Note: this could be as restrictive as if (handle & ~(mask >> shift))
286          * but then, we'd fail handles that may become valid after some future
287          * mask change. While this is extremely unlikely to ever matter,
288          * the check below is safer (and also more backwards-compatible).
289          */
290         if (cp.perfect || valid_perfect_hash(&cp))
291                 if (handle >= cp.alloc_hash)
292                         goto errout;
293
294
295         err = -ENOMEM;
296         if (!cp.perfect && !cp.h) {
297                 if (valid_perfect_hash(&cp)) {
298                         cp.perfect = kcalloc(cp.hash, sizeof(*r), GFP_KERNEL);
299                         if (!cp.perfect)
300                                 goto errout;
301                         balloc = 1;
302                 } else {
303                         cp.h = kcalloc(cp.hash, sizeof(f), GFP_KERNEL);
304                         if (!cp.h)
305                                 goto errout;
306                         balloc = 2;
307                 }
308         }
309
310         if (cp.perfect)
311                 r = cp.perfect + handle;
312         else
313                 r = tcindex_lookup(&cp, handle) ? : &new_filter_result;
314
315         if (r == &new_filter_result) {
316                 f = kzalloc(sizeof(*f), GFP_KERNEL);
317                 if (!f)
318                         goto errout_alloc;
319         }
320
321         if (tb[TCA_TCINDEX_CLASSID-1]) {
322                 cr.res.classid = *(u32 *) RTA_DATA(tb[TCA_TCINDEX_CLASSID-1]);
323                 tcf_bind_filter(tp, &cr.res, base);
324         }
325
326         tcf_exts_change(tp, &cr.exts, &e);
327
328         tcf_tree_lock(tp);
329         if (old_r && old_r != r)
330                 memset(old_r, 0, sizeof(*old_r));
331
332         memcpy(p, &cp, sizeof(cp));
333         memcpy(r, &cr, sizeof(cr));
334
335         if (r == &new_filter_result) {
336                 struct tcindex_filter **fp;
337
338                 f->key = handle;
339                 f->result = new_filter_result;
340                 f->next = NULL;
341                 for (fp = p->h+(handle % p->hash); *fp; fp = &(*fp)->next)
342                         /* nothing */;
343                 *fp = f;
344         }
345         tcf_tree_unlock(tp);
346
347         return 0;
348
349 errout_alloc:
350         if (balloc == 1)
351                 kfree(cp.perfect);
352         else if (balloc == 2)
353                 kfree(cp.h);
354 errout:
355         tcf_exts_destroy(tp, &e);
356         return err;
357 }
358
359 static int
360 tcindex_change(struct tcf_proto *tp, unsigned long base, u32 handle,
361                struct rtattr **tca, unsigned long *arg)
362 {
363         struct rtattr *opt = tca[TCA_OPTIONS-1];
364         struct rtattr *tb[TCA_TCINDEX_MAX];
365         struct tcindex_data *p = PRIV(tp);
366         struct tcindex_filter_result *r = (struct tcindex_filter_result *) *arg;
367
368         DPRINTK("tcindex_change(tp %p,handle 0x%08x,tca %p,arg %p),opt %p,"
369             "p %p,r %p,*arg 0x%lx\n",
370             tp, handle, tca, arg, opt, p, r, arg ? *arg : 0L);
371
372         if (!opt)
373                 return 0;
374
375         if (rtattr_parse_nested(tb, TCA_TCINDEX_MAX, opt) < 0)
376                 return -EINVAL;
377
378         return tcindex_set_parms(tp, base, handle, p, r, tb, tca[TCA_RATE-1]);
379 }
380
381
382 static void tcindex_walk(struct tcf_proto *tp, struct tcf_walker *walker)
383 {
384         struct tcindex_data *p = PRIV(tp);
385         struct tcindex_filter *f,*next;
386         int i;
387
388         DPRINTK("tcindex_walk(tp %p,walker %p),p %p\n",tp,walker,p);
389         if (p->perfect) {
390                 for (i = 0; i < p->hash; i++) {
391                         if (!p->perfect[i].res.class)
392                                 continue;
393                         if (walker->count >= walker->skip) {
394                                 if (walker->fn(tp,
395                                     (unsigned long) (p->perfect+i), walker)
396                                      < 0) {
397                                         walker->stop = 1;
398                                         return;
399                                 }
400                         }
401                         walker->count++;
402                 }
403         }
404         if (!p->h)
405                 return;
406         for (i = 0; i < p->hash; i++) {
407                 for (f = p->h[i]; f; f = next) {
408                         next = f->next;
409                         if (walker->count >= walker->skip) {
410                                 if (walker->fn(tp,(unsigned long) &f->result,
411                                     walker) < 0) {
412                                         walker->stop = 1;
413                                         return;
414                                 }
415                         }
416                         walker->count++;
417                 }
418         }
419 }
420
421
422 static int tcindex_destroy_element(struct tcf_proto *tp,
423     unsigned long arg, struct tcf_walker *walker)
424 {
425         return __tcindex_delete(tp, arg, 0);
426 }
427
428
429 static void tcindex_destroy(struct tcf_proto *tp)
430 {
431         struct tcindex_data *p = PRIV(tp);
432         struct tcf_walker walker;
433
434         DPRINTK("tcindex_destroy(tp %p),p %p\n",tp,p);
435         walker.count = 0;
436         walker.skip = 0;
437         walker.fn = &tcindex_destroy_element;
438         tcindex_walk(tp,&walker);
439         kfree(p->perfect);
440         kfree(p->h);
441         kfree(p);
442         tp->root = NULL;
443 }
444
445
446 static int tcindex_dump(struct tcf_proto *tp, unsigned long fh,
447     struct sk_buff *skb, struct tcmsg *t)
448 {
449         struct tcindex_data *p = PRIV(tp);
450         struct tcindex_filter_result *r = (struct tcindex_filter_result *) fh;
451         unsigned char *b = skb->tail;
452         struct rtattr *rta;
453
454         DPRINTK("tcindex_dump(tp %p,fh 0x%lx,skb %p,t %p),p %p,r %p,b %p\n",
455             tp,fh,skb,t,p,r,b);
456         DPRINTK("p->perfect %p p->h %p\n",p->perfect,p->h);
457         rta = (struct rtattr *) b;
458         RTA_PUT(skb,TCA_OPTIONS,0,NULL);
459         if (!fh) {
460                 t->tcm_handle = ~0; /* whatever ... */
461                 RTA_PUT(skb,TCA_TCINDEX_HASH,sizeof(p->hash),&p->hash);
462                 RTA_PUT(skb,TCA_TCINDEX_MASK,sizeof(p->mask),&p->mask);
463                 RTA_PUT(skb,TCA_TCINDEX_SHIFT,sizeof(p->shift),&p->shift);
464                 RTA_PUT(skb,TCA_TCINDEX_FALL_THROUGH,sizeof(p->fall_through),
465                     &p->fall_through);
466                 rta->rta_len = skb->tail-b;
467         } else {
468                 if (p->perfect) {
469                         t->tcm_handle = r-p->perfect;
470                 } else {
471                         struct tcindex_filter *f;
472                         int i;
473
474                         t->tcm_handle = 0;
475                         for (i = 0; !t->tcm_handle && i < p->hash; i++) {
476                                 for (f = p->h[i]; !t->tcm_handle && f;
477                                      f = f->next) {
478                                         if (&f->result == r)
479                                                 t->tcm_handle = f->key;
480                                 }
481                         }
482                 }
483                 DPRINTK("handle = %d\n",t->tcm_handle);
484                 if (r->res.class)
485                         RTA_PUT(skb, TCA_TCINDEX_CLASSID, 4, &r->res.classid);
486
487                 if (tcf_exts_dump(skb, &r->exts, &tcindex_ext_map) < 0)
488                         goto rtattr_failure;
489                 rta->rta_len = skb->tail-b;
490
491                 if (tcf_exts_dump_stats(skb, &r->exts, &tcindex_ext_map) < 0)
492                         goto rtattr_failure;
493         }
494         
495         return skb->len;
496
497 rtattr_failure:
498         skb_trim(skb, b - skb->data);
499         return -1;
500 }
501
502 static struct tcf_proto_ops cls_tcindex_ops = {
503         .next           =       NULL,
504         .kind           =       "tcindex",
505         .classify       =       tcindex_classify,
506         .init           =       tcindex_init,
507         .destroy        =       tcindex_destroy,
508         .get            =       tcindex_get,
509         .put            =       tcindex_put,
510         .change         =       tcindex_change,
511         .delete         =       tcindex_delete,
512         .walk           =       tcindex_walk,
513         .dump           =       tcindex_dump,
514         .owner          =       THIS_MODULE,
515 };
516
517 static int __init init_tcindex(void)
518 {
519         return register_tcf_proto_ops(&cls_tcindex_ops);
520 }
521
522 static void __exit exit_tcindex(void) 
523 {
524         unregister_tcf_proto_ops(&cls_tcindex_ops);
525 }
526
527 module_init(init_tcindex)
528 module_exit(exit_tcindex)
529 MODULE_LICENSE("GPL");