ACPICA: Fix for some comments/headers
[platform/adaptation/renesas_rcar/renesas_kernel.git] / net / sched / cls_route.c
1 /*
2  * net/sched/cls_route.c        ROUTE4 classifier.
3  *
4  *              This program is free software; you can redistribute it and/or
5  *              modify it under the terms of the GNU General Public License
6  *              as published by the Free Software Foundation; either version
7  *              2 of the License, or (at your option) any later version.
8  *
9  * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10  */
11
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/types.h>
15 #include <linux/kernel.h>
16 #include <linux/string.h>
17 #include <linux/errno.h>
18 #include <linux/skbuff.h>
19 #include <net/dst.h>
20 #include <net/route.h>
21 #include <net/netlink.h>
22 #include <net/act_api.h>
23 #include <net/pkt_cls.h>
24
25 /*
26  * 1. For now we assume that route tags < 256.
27  *    It allows to use direct table lookups, instead of hash tables.
28  * 2. For now we assume that "from TAG" and "fromdev DEV" statements
29  *    are mutually  exclusive.
30  * 3. "to TAG from ANY" has higher priority, than "to ANY from XXX"
31  */
32
33 struct route4_fastmap {
34         struct route4_filter    *filter;
35         u32                     id;
36         int                     iif;
37 };
38
39 struct route4_head {
40         struct route4_fastmap   fastmap[16];
41         struct route4_bucket    *table[256 + 1];
42 };
43
44 struct route4_bucket {
45         /* 16 FROM buckets + 16 IIF buckets + 1 wildcard bucket */
46         struct route4_filter    *ht[16 + 16 + 1];
47 };
48
49 struct route4_filter {
50         struct route4_filter    *next;
51         u32                     id;
52         int                     iif;
53
54         struct tcf_result       res;
55         struct tcf_exts         exts;
56         u32                     handle;
57         struct route4_bucket    *bkt;
58 };
59
60 #define ROUTE4_FAILURE ((struct route4_filter *)(-1L))
61
62 static const struct tcf_ext_map route_ext_map = {
63         .police = TCA_ROUTE4_POLICE,
64         .action = TCA_ROUTE4_ACT
65 };
66
67 static inline int route4_fastmap_hash(u32 id, int iif)
68 {
69         return id & 0xF;
70 }
71
72 static void
73 route4_reset_fastmap(struct Qdisc *q, struct route4_head *head, u32 id)
74 {
75         spinlock_t *root_lock = qdisc_root_sleeping_lock(q);
76
77         spin_lock_bh(root_lock);
78         memset(head->fastmap, 0, sizeof(head->fastmap));
79         spin_unlock_bh(root_lock);
80 }
81
82 static void
83 route4_set_fastmap(struct route4_head *head, u32 id, int iif,
84                    struct route4_filter *f)
85 {
86         int h = route4_fastmap_hash(id, iif);
87
88         head->fastmap[h].id = id;
89         head->fastmap[h].iif = iif;
90         head->fastmap[h].filter = f;
91 }
92
93 static inline int route4_hash_to(u32 id)
94 {
95         return id & 0xFF;
96 }
97
98 static inline int route4_hash_from(u32 id)
99 {
100         return (id >> 16) & 0xF;
101 }
102
103 static inline int route4_hash_iif(int iif)
104 {
105         return 16 + ((iif >> 16) & 0xF);
106 }
107
108 static inline int route4_hash_wild(void)
109 {
110         return 32;
111 }
112
113 #define ROUTE4_APPLY_RESULT()                                   \
114 {                                                               \
115         *res = f->res;                                          \
116         if (tcf_exts_is_available(&f->exts)) {                  \
117                 int r = tcf_exts_exec(skb, &f->exts, res);      \
118                 if (r < 0) {                                    \
119                         dont_cache = 1;                         \
120                         continue;                               \
121                 }                                               \
122                 return r;                                       \
123         } else if (!dont_cache)                                 \
124                 route4_set_fastmap(head, id, iif, f);           \
125         return 0;                                               \
126 }
127
128 static int route4_classify(struct sk_buff *skb, const struct tcf_proto *tp,
129                            struct tcf_result *res)
130 {
131         struct route4_head *head = (struct route4_head *)tp->root;
132         struct dst_entry *dst;
133         struct route4_bucket *b;
134         struct route4_filter *f;
135         u32 id, h;
136         int iif, dont_cache = 0;
137
138         dst = skb_dst(skb);
139         if (!dst)
140                 goto failure;
141
142         id = dst->tclassid;
143         if (head == NULL)
144                 goto old_method;
145
146         iif = inet_iif(skb);
147
148         h = route4_fastmap_hash(id, iif);
149         if (id == head->fastmap[h].id &&
150             iif == head->fastmap[h].iif &&
151             (f = head->fastmap[h].filter) != NULL) {
152                 if (f == ROUTE4_FAILURE)
153                         goto failure;
154
155                 *res = f->res;
156                 return 0;
157         }
158
159         h = route4_hash_to(id);
160
161 restart:
162         b = head->table[h];
163         if (b) {
164                 for (f = b->ht[route4_hash_from(id)]; f; f = f->next)
165                         if (f->id == id)
166                                 ROUTE4_APPLY_RESULT();
167
168                 for (f = b->ht[route4_hash_iif(iif)]; f; f = f->next)
169                         if (f->iif == iif)
170                                 ROUTE4_APPLY_RESULT();
171
172                 for (f = b->ht[route4_hash_wild()]; f; f = f->next)
173                         ROUTE4_APPLY_RESULT();
174
175         }
176         if (h < 256) {
177                 h = 256;
178                 id &= ~0xFFFF;
179                 goto restart;
180         }
181
182         if (!dont_cache)
183                 route4_set_fastmap(head, id, iif, ROUTE4_FAILURE);
184 failure:
185         return -1;
186
187 old_method:
188         if (id && (TC_H_MAJ(id) == 0 ||
189                    !(TC_H_MAJ(id^tp->q->handle)))) {
190                 res->classid = id;
191                 res->class = 0;
192                 return 0;
193         }
194         return -1;
195 }
196
197 static inline u32 to_hash(u32 id)
198 {
199         u32 h = id & 0xFF;
200
201         if (id & 0x8000)
202                 h += 256;
203         return h;
204 }
205
206 static inline u32 from_hash(u32 id)
207 {
208         id &= 0xFFFF;
209         if (id == 0xFFFF)
210                 return 32;
211         if (!(id & 0x8000)) {
212                 if (id > 255)
213                         return 256;
214                 return id & 0xF;
215         }
216         return 16 + (id & 0xF);
217 }
218
219 static unsigned long route4_get(struct tcf_proto *tp, u32 handle)
220 {
221         struct route4_head *head = (struct route4_head *)tp->root;
222         struct route4_bucket *b;
223         struct route4_filter *f;
224         unsigned int h1, h2;
225
226         if (!head)
227                 return 0;
228
229         h1 = to_hash(handle);
230         if (h1 > 256)
231                 return 0;
232
233         h2 = from_hash(handle >> 16);
234         if (h2 > 32)
235                 return 0;
236
237         b = head->table[h1];
238         if (b) {
239                 for (f = b->ht[h2]; f; f = f->next)
240                         if (f->handle == handle)
241                                 return (unsigned long)f;
242         }
243         return 0;
244 }
245
246 static void route4_put(struct tcf_proto *tp, unsigned long f)
247 {
248 }
249
250 static int route4_init(struct tcf_proto *tp)
251 {
252         return 0;
253 }
254
255 static void
256 route4_delete_filter(struct tcf_proto *tp, struct route4_filter *f)
257 {
258         tcf_unbind_filter(tp, &f->res);
259         tcf_exts_destroy(tp, &f->exts);
260         kfree(f);
261 }
262
263 static void route4_destroy(struct tcf_proto *tp)
264 {
265         struct route4_head *head = tp->root;
266         int h1, h2;
267
268         if (head == NULL)
269                 return;
270
271         for (h1 = 0; h1 <= 256; h1++) {
272                 struct route4_bucket *b;
273
274                 b = head->table[h1];
275                 if (b) {
276                         for (h2 = 0; h2 <= 32; h2++) {
277                                 struct route4_filter *f;
278
279                                 while ((f = b->ht[h2]) != NULL) {
280                                         b->ht[h2] = f->next;
281                                         route4_delete_filter(tp, f);
282                                 }
283                         }
284                         kfree(b);
285                 }
286         }
287         kfree(head);
288 }
289
290 static int route4_delete(struct tcf_proto *tp, unsigned long arg)
291 {
292         struct route4_head *head = (struct route4_head *)tp->root;
293         struct route4_filter **fp, *f = (struct route4_filter *)arg;
294         unsigned int h = 0;
295         struct route4_bucket *b;
296         int i;
297
298         if (!head || !f)
299                 return -EINVAL;
300
301         h = f->handle;
302         b = f->bkt;
303
304         for (fp = &b->ht[from_hash(h >> 16)]; *fp; fp = &(*fp)->next) {
305                 if (*fp == f) {
306                         tcf_tree_lock(tp);
307                         *fp = f->next;
308                         tcf_tree_unlock(tp);
309
310                         route4_reset_fastmap(tp->q, head, f->id);
311                         route4_delete_filter(tp, f);
312
313                         /* Strip tree */
314
315                         for (i = 0; i <= 32; i++)
316                                 if (b->ht[i])
317                                         return 0;
318
319                         /* OK, session has no flows */
320                         tcf_tree_lock(tp);
321                         head->table[to_hash(h)] = NULL;
322                         tcf_tree_unlock(tp);
323
324                         kfree(b);
325                         return 0;
326                 }
327         }
328         return 0;
329 }
330
331 static const struct nla_policy route4_policy[TCA_ROUTE4_MAX + 1] = {
332         [TCA_ROUTE4_CLASSID]    = { .type = NLA_U32 },
333         [TCA_ROUTE4_TO]         = { .type = NLA_U32 },
334         [TCA_ROUTE4_FROM]       = { .type = NLA_U32 },
335         [TCA_ROUTE4_IIF]        = { .type = NLA_U32 },
336 };
337
338 static int route4_set_parms(struct net *net, struct tcf_proto *tp,
339                             unsigned long base, struct route4_filter *f,
340                             u32 handle, struct route4_head *head,
341                             struct nlattr **tb, struct nlattr *est, int new)
342 {
343         int err;
344         u32 id = 0, to = 0, nhandle = 0x8000;
345         struct route4_filter *fp;
346         unsigned int h1;
347         struct route4_bucket *b;
348         struct tcf_exts e;
349
350         err = tcf_exts_validate(net, tp, tb, est, &e, &route_ext_map);
351         if (err < 0)
352                 return err;
353
354         err = -EINVAL;
355         if (tb[TCA_ROUTE4_TO]) {
356                 if (new && handle & 0x8000)
357                         goto errout;
358                 to = nla_get_u32(tb[TCA_ROUTE4_TO]);
359                 if (to > 0xFF)
360                         goto errout;
361                 nhandle = to;
362         }
363
364         if (tb[TCA_ROUTE4_FROM]) {
365                 if (tb[TCA_ROUTE4_IIF])
366                         goto errout;
367                 id = nla_get_u32(tb[TCA_ROUTE4_FROM]);
368                 if (id > 0xFF)
369                         goto errout;
370                 nhandle |= id << 16;
371         } else if (tb[TCA_ROUTE4_IIF]) {
372                 id = nla_get_u32(tb[TCA_ROUTE4_IIF]);
373                 if (id > 0x7FFF)
374                         goto errout;
375                 nhandle |= (id | 0x8000) << 16;
376         } else
377                 nhandle |= 0xFFFF << 16;
378
379         if (handle && new) {
380                 nhandle |= handle & 0x7F00;
381                 if (nhandle != handle)
382                         goto errout;
383         }
384
385         h1 = to_hash(nhandle);
386         b = head->table[h1];
387         if (!b) {
388                 err = -ENOBUFS;
389                 b = kzalloc(sizeof(struct route4_bucket), GFP_KERNEL);
390                 if (b == NULL)
391                         goto errout;
392
393                 tcf_tree_lock(tp);
394                 head->table[h1] = b;
395                 tcf_tree_unlock(tp);
396         } else {
397                 unsigned int h2 = from_hash(nhandle >> 16);
398
399                 err = -EEXIST;
400                 for (fp = b->ht[h2]; fp; fp = fp->next)
401                         if (fp->handle == f->handle)
402                                 goto errout;
403         }
404
405         tcf_tree_lock(tp);
406         if (tb[TCA_ROUTE4_TO])
407                 f->id = to;
408
409         if (tb[TCA_ROUTE4_FROM])
410                 f->id = to | id<<16;
411         else if (tb[TCA_ROUTE4_IIF])
412                 f->iif = id;
413
414         f->handle = nhandle;
415         f->bkt = b;
416         tcf_tree_unlock(tp);
417
418         if (tb[TCA_ROUTE4_CLASSID]) {
419                 f->res.classid = nla_get_u32(tb[TCA_ROUTE4_CLASSID]);
420                 tcf_bind_filter(tp, &f->res, base);
421         }
422
423         tcf_exts_change(tp, &f->exts, &e);
424
425         return 0;
426 errout:
427         tcf_exts_destroy(tp, &e);
428         return err;
429 }
430
431 static int route4_change(struct net *net, struct sk_buff *in_skb,
432                        struct tcf_proto *tp, unsigned long base,
433                        u32 handle,
434                        struct nlattr **tca,
435                        unsigned long *arg)
436 {
437         struct route4_head *head = tp->root;
438         struct route4_filter *f, *f1, **fp;
439         struct route4_bucket *b;
440         struct nlattr *opt = tca[TCA_OPTIONS];
441         struct nlattr *tb[TCA_ROUTE4_MAX + 1];
442         unsigned int h, th;
443         u32 old_handle = 0;
444         int err;
445
446         if (opt == NULL)
447                 return handle ? -EINVAL : 0;
448
449         err = nla_parse_nested(tb, TCA_ROUTE4_MAX, opt, route4_policy);
450         if (err < 0)
451                 return err;
452
453         f = (struct route4_filter *)*arg;
454         if (f) {
455                 if (f->handle != handle && handle)
456                         return -EINVAL;
457
458                 if (f->bkt)
459                         old_handle = f->handle;
460
461                 err = route4_set_parms(net, tp, base, f, handle, head, tb,
462                         tca[TCA_RATE], 0);
463                 if (err < 0)
464                         return err;
465
466                 goto reinsert;
467         }
468
469         err = -ENOBUFS;
470         if (head == NULL) {
471                 head = kzalloc(sizeof(struct route4_head), GFP_KERNEL);
472                 if (head == NULL)
473                         goto errout;
474
475                 tcf_tree_lock(tp);
476                 tp->root = head;
477                 tcf_tree_unlock(tp);
478         }
479
480         f = kzalloc(sizeof(struct route4_filter), GFP_KERNEL);
481         if (f == NULL)
482                 goto errout;
483
484         err = route4_set_parms(net, tp, base, f, handle, head, tb,
485                 tca[TCA_RATE], 1);
486         if (err < 0)
487                 goto errout;
488
489 reinsert:
490         h = from_hash(f->handle >> 16);
491         for (fp = &f->bkt->ht[h]; (f1 = *fp) != NULL; fp = &f1->next)
492                 if (f->handle < f1->handle)
493                         break;
494
495         f->next = f1;
496         tcf_tree_lock(tp);
497         *fp = f;
498
499         if (old_handle && f->handle != old_handle) {
500                 th = to_hash(old_handle);
501                 h = from_hash(old_handle >> 16);
502                 b = head->table[th];
503                 if (b) {
504                         for (fp = &b->ht[h]; *fp; fp = &(*fp)->next) {
505                                 if (*fp == f) {
506                                         *fp = f->next;
507                                         break;
508                                 }
509                         }
510                 }
511         }
512         tcf_tree_unlock(tp);
513
514         route4_reset_fastmap(tp->q, head, f->id);
515         *arg = (unsigned long)f;
516         return 0;
517
518 errout:
519         kfree(f);
520         return err;
521 }
522
523 static void route4_walk(struct tcf_proto *tp, struct tcf_walker *arg)
524 {
525         struct route4_head *head = tp->root;
526         unsigned int h, h1;
527
528         if (head == NULL)
529                 arg->stop = 1;
530
531         if (arg->stop)
532                 return;
533
534         for (h = 0; h <= 256; h++) {
535                 struct route4_bucket *b = head->table[h];
536
537                 if (b) {
538                         for (h1 = 0; h1 <= 32; h1++) {
539                                 struct route4_filter *f;
540
541                                 for (f = b->ht[h1]; f; f = f->next) {
542                                         if (arg->count < arg->skip) {
543                                                 arg->count++;
544                                                 continue;
545                                         }
546                                         if (arg->fn(tp, (unsigned long)f, arg) < 0) {
547                                                 arg->stop = 1;
548                                                 return;
549                                         }
550                                         arg->count++;
551                                 }
552                         }
553                 }
554         }
555 }
556
557 static int route4_dump(struct tcf_proto *tp, unsigned long fh,
558                        struct sk_buff *skb, struct tcmsg *t)
559 {
560         struct route4_filter *f = (struct route4_filter *)fh;
561         unsigned char *b = skb_tail_pointer(skb);
562         struct nlattr *nest;
563         u32 id;
564
565         if (f == NULL)
566                 return skb->len;
567
568         t->tcm_handle = f->handle;
569
570         nest = nla_nest_start(skb, TCA_OPTIONS);
571         if (nest == NULL)
572                 goto nla_put_failure;
573
574         if (!(f->handle & 0x8000)) {
575                 id = f->id & 0xFF;
576                 if (nla_put_u32(skb, TCA_ROUTE4_TO, id))
577                         goto nla_put_failure;
578         }
579         if (f->handle & 0x80000000) {
580                 if ((f->handle >> 16) != 0xFFFF &&
581                     nla_put_u32(skb, TCA_ROUTE4_IIF, f->iif))
582                         goto nla_put_failure;
583         } else {
584                 id = f->id >> 16;
585                 if (nla_put_u32(skb, TCA_ROUTE4_FROM, id))
586                         goto nla_put_failure;
587         }
588         if (f->res.classid &&
589             nla_put_u32(skb, TCA_ROUTE4_CLASSID, f->res.classid))
590                 goto nla_put_failure;
591
592         if (tcf_exts_dump(skb, &f->exts, &route_ext_map) < 0)
593                 goto nla_put_failure;
594
595         nla_nest_end(skb, nest);
596
597         if (tcf_exts_dump_stats(skb, &f->exts, &route_ext_map) < 0)
598                 goto nla_put_failure;
599
600         return skb->len;
601
602 nla_put_failure:
603         nlmsg_trim(skb, b);
604         return -1;
605 }
606
607 static struct tcf_proto_ops cls_route4_ops __read_mostly = {
608         .kind           =       "route",
609         .classify       =       route4_classify,
610         .init           =       route4_init,
611         .destroy        =       route4_destroy,
612         .get            =       route4_get,
613         .put            =       route4_put,
614         .change         =       route4_change,
615         .delete         =       route4_delete,
616         .walk           =       route4_walk,
617         .dump           =       route4_dump,
618         .owner          =       THIS_MODULE,
619 };
620
621 static int __init init_route4(void)
622 {
623         return register_tcf_proto_ops(&cls_route4_ops);
624 }
625
626 static void __exit exit_route4(void)
627 {
628         unregister_tcf_proto_ops(&cls_route4_ops);
629 }
630
631 module_init(init_route4)
632 module_exit(exit_route4)
633 MODULE_LICENSE("GPL");