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Linux/net/sched/cls_u32.c

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  1 /*
  2  * net/sched/cls_u32.c  Ugly (or Universal) 32bit key Packet 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  *      The filters are packed to hash tables of key nodes
 12  *      with a set of 32bit key/mask pairs at every node.
 13  *      Nodes reference next level hash tables etc.
 14  *
 15  *      This scheme is the best universal classifier I managed to
 16  *      invent; it is not super-fast, but it is not slow (provided you
 17  *      program it correctly), and general enough.  And its relative
 18  *      speed grows as the number of rules becomes larger.
 19  *
 20  *      It seems that it represents the best middle point between
 21  *      speed and manageability both by human and by machine.
 22  *
 23  *      It is especially useful for link sharing combined with QoS;
 24  *      pure RSVP doesn't need such a general approach and can use
 25  *      much simpler (and faster) schemes, sort of cls_rsvp.c.
 26  *
 27  *      JHS: We should remove the CONFIG_NET_CLS_IND from here
 28  *      eventually when the meta match extension is made available
 29  *
 30  *      nfmark match added by Catalin(ux aka Dino) BOIE <catab at umbrella.ro>
 31  */
 32 
 33 #include <linux/module.h>
 34 #include <linux/slab.h>
 35 #include <linux/types.h>
 36 #include <linux/kernel.h>
 37 #include <linux/string.h>
 38 #include <linux/errno.h>
 39 #include <linux/percpu.h>
 40 #include <linux/rtnetlink.h>
 41 #include <linux/skbuff.h>
 42 #include <linux/bitmap.h>
 43 #include <net/netlink.h>
 44 #include <net/act_api.h>
 45 #include <net/pkt_cls.h>
 46 #include <linux/netdevice.h>
 47 
 48 struct tc_u_knode {
 49         struct tc_u_knode __rcu *next;
 50         u32                     handle;
 51         struct tc_u_hnode __rcu *ht_up;
 52         struct tcf_exts         exts;
 53 #ifdef CONFIG_NET_CLS_IND
 54         int                     ifindex;
 55 #endif
 56         u8                      fshift;
 57         struct tcf_result       res;
 58         struct tc_u_hnode __rcu *ht_down;
 59 #ifdef CONFIG_CLS_U32_PERF
 60         struct tc_u32_pcnt __percpu *pf;
 61 #endif
 62         u32                     flags;
 63 #ifdef CONFIG_CLS_U32_MARK
 64         u32                     val;
 65         u32                     mask;
 66         u32 __percpu            *pcpu_success;
 67 #endif
 68         struct tcf_proto        *tp;
 69         struct rcu_head         rcu;
 70         /* The 'sel' field MUST be the last field in structure to allow for
 71          * tc_u32_keys allocated at end of structure.
 72          */
 73         struct tc_u32_sel       sel;
 74 };
 75 
 76 struct tc_u_hnode {
 77         struct tc_u_hnode __rcu *next;
 78         u32                     handle;
 79         u32                     prio;
 80         struct tc_u_common      *tp_c;
 81         int                     refcnt;
 82         unsigned int            divisor;
 83         struct rcu_head         rcu;
 84         /* The 'ht' field MUST be the last field in structure to allow for
 85          * more entries allocated at end of structure.
 86          */
 87         struct tc_u_knode __rcu *ht[1];
 88 };
 89 
 90 struct tc_u_common {
 91         struct tc_u_hnode __rcu *hlist;
 92         struct Qdisc            *q;
 93         int                     refcnt;
 94         u32                     hgenerator;
 95         struct rcu_head         rcu;
 96 };
 97 
 98 static inline unsigned int u32_hash_fold(__be32 key,
 99                                          const struct tc_u32_sel *sel,
100                                          u8 fshift)
101 {
102         unsigned int h = ntohl(key & sel->hmask) >> fshift;
103 
104         return h;
105 }
106 
107 static int u32_classify(struct sk_buff *skb, const struct tcf_proto *tp,
108                         struct tcf_result *res)
109 {
110         struct {
111                 struct tc_u_knode *knode;
112                 unsigned int      off;
113         } stack[TC_U32_MAXDEPTH];
114 
115         struct tc_u_hnode *ht = rcu_dereference_bh(tp->root);
116         unsigned int off = skb_network_offset(skb);
117         struct tc_u_knode *n;
118         int sdepth = 0;
119         int off2 = 0;
120         int sel = 0;
121 #ifdef CONFIG_CLS_U32_PERF
122         int j;
123 #endif
124         int i, r;
125 
126 next_ht:
127         n = rcu_dereference_bh(ht->ht[sel]);
128 
129 next_knode:
130         if (n) {
131                 struct tc_u32_key *key = n->sel.keys;
132 
133 #ifdef CONFIG_CLS_U32_PERF
134                 __this_cpu_inc(n->pf->rcnt);
135                 j = 0;
136 #endif
137 
138                 if (tc_skip_sw(n->flags)) {
139                         n = rcu_dereference_bh(n->next);
140                         goto next_knode;
141                 }
142 
143 #ifdef CONFIG_CLS_U32_MARK
144                 if ((skb->mark & n->mask) != n->val) {
145                         n = rcu_dereference_bh(n->next);
146                         goto next_knode;
147                 } else {
148                         __this_cpu_inc(*n->pcpu_success);
149                 }
150 #endif
151 
152                 for (i = n->sel.nkeys; i > 0; i--, key++) {
153                         int toff = off + key->off + (off2 & key->offmask);
154                         __be32 *data, hdata;
155 
156                         if (skb_headroom(skb) + toff > INT_MAX)
157                                 goto out;
158 
159                         data = skb_header_pointer(skb, toff, 4, &hdata);
160                         if (!data)
161                                 goto out;
162                         if ((*data ^ key->val) & key->mask) {
163                                 n = rcu_dereference_bh(n->next);
164                                 goto next_knode;
165                         }
166 #ifdef CONFIG_CLS_U32_PERF
167                         __this_cpu_inc(n->pf->kcnts[j]);
168                         j++;
169 #endif
170                 }
171 
172                 ht = rcu_dereference_bh(n->ht_down);
173                 if (!ht) {
174 check_terminal:
175                         if (n->sel.flags & TC_U32_TERMINAL) {
176 
177                                 *res = n->res;
178 #ifdef CONFIG_NET_CLS_IND
179                                 if (!tcf_match_indev(skb, n->ifindex)) {
180                                         n = rcu_dereference_bh(n->next);
181                                         goto next_knode;
182                                 }
183 #endif
184 #ifdef CONFIG_CLS_U32_PERF
185                                 __this_cpu_inc(n->pf->rhit);
186 #endif
187                                 r = tcf_exts_exec(skb, &n->exts, res);
188                                 if (r < 0) {
189                                         n = rcu_dereference_bh(n->next);
190                                         goto next_knode;
191                                 }
192 
193                                 return r;
194                         }
195                         n = rcu_dereference_bh(n->next);
196                         goto next_knode;
197                 }
198 
199                 /* PUSH */
200                 if (sdepth >= TC_U32_MAXDEPTH)
201                         goto deadloop;
202                 stack[sdepth].knode = n;
203                 stack[sdepth].off = off;
204                 sdepth++;
205 
206                 ht = rcu_dereference_bh(n->ht_down);
207                 sel = 0;
208                 if (ht->divisor) {
209                         __be32 *data, hdata;
210 
211                         data = skb_header_pointer(skb, off + n->sel.hoff, 4,
212                                                   &hdata);
213                         if (!data)
214                                 goto out;
215                         sel = ht->divisor & u32_hash_fold(*data, &n->sel,
216                                                           n->fshift);
217                 }
218                 if (!(n->sel.flags & (TC_U32_VAROFFSET | TC_U32_OFFSET | TC_U32_EAT)))
219                         goto next_ht;
220 
221                 if (n->sel.flags & (TC_U32_OFFSET | TC_U32_VAROFFSET)) {
222                         off2 = n->sel.off + 3;
223                         if (n->sel.flags & TC_U32_VAROFFSET) {
224                                 __be16 *data, hdata;
225 
226                                 data = skb_header_pointer(skb,
227                                                           off + n->sel.offoff,
228                                                           2, &hdata);
229                                 if (!data)
230                                         goto out;
231                                 off2 += ntohs(n->sel.offmask & *data) >>
232                                         n->sel.offshift;
233                         }
234                         off2 &= ~3;
235                 }
236                 if (n->sel.flags & TC_U32_EAT) {
237                         off += off2;
238                         off2 = 0;
239                 }
240 
241                 if (off < skb->len)
242                         goto next_ht;
243         }
244 
245         /* POP */
246         if (sdepth--) {
247                 n = stack[sdepth].knode;
248                 ht = rcu_dereference_bh(n->ht_up);
249                 off = stack[sdepth].off;
250                 goto check_terminal;
251         }
252 out:
253         return -1;
254 
255 deadloop:
256         net_warn_ratelimited("cls_u32: dead loop\n");
257         return -1;
258 }
259 
260 static struct tc_u_hnode *u32_lookup_ht(struct tc_u_common *tp_c, u32 handle)
261 {
262         struct tc_u_hnode *ht;
263 
264         for (ht = rtnl_dereference(tp_c->hlist);
265              ht;
266              ht = rtnl_dereference(ht->next))
267                 if (ht->handle == handle)
268                         break;
269 
270         return ht;
271 }
272 
273 static struct tc_u_knode *u32_lookup_key(struct tc_u_hnode *ht, u32 handle)
274 {
275         unsigned int sel;
276         struct tc_u_knode *n = NULL;
277 
278         sel = TC_U32_HASH(handle);
279         if (sel > ht->divisor)
280                 goto out;
281 
282         for (n = rtnl_dereference(ht->ht[sel]);
283              n;
284              n = rtnl_dereference(n->next))
285                 if (n->handle == handle)
286                         break;
287 out:
288         return n;
289 }
290 
291 
292 static unsigned long u32_get(struct tcf_proto *tp, u32 handle)
293 {
294         struct tc_u_hnode *ht;
295         struct tc_u_common *tp_c = tp->data;
296 
297         if (TC_U32_HTID(handle) == TC_U32_ROOT)
298                 ht = rtnl_dereference(tp->root);
299         else
300                 ht = u32_lookup_ht(tp_c, TC_U32_HTID(handle));
301 
302         if (!ht)
303                 return 0;
304 
305         if (TC_U32_KEY(handle) == 0)
306                 return (unsigned long)ht;
307 
308         return (unsigned long)u32_lookup_key(ht, handle);
309 }
310 
311 static u32 gen_new_htid(struct tc_u_common *tp_c)
312 {
313         int i = 0x800;
314 
315         /* hgenerator only used inside rtnl lock it is safe to increment
316          * without read _copy_ update semantics
317          */
318         do {
319                 if (++tp_c->hgenerator == 0x7FF)
320                         tp_c->hgenerator = 1;
321         } while (--i > 0 && u32_lookup_ht(tp_c, (tp_c->hgenerator|0x800)<<20));
322 
323         return i > 0 ? (tp_c->hgenerator|0x800)<<20 : 0;
324 }
325 
326 static int u32_init(struct tcf_proto *tp)
327 {
328         struct tc_u_hnode *root_ht;
329         struct tc_u_common *tp_c;
330 
331         tp_c = tp->q->u32_node;
332 
333         root_ht = kzalloc(sizeof(*root_ht), GFP_KERNEL);
334         if (root_ht == NULL)
335                 return -ENOBUFS;
336 
337         root_ht->divisor = 0;
338         root_ht->refcnt++;
339         root_ht->handle = tp_c ? gen_new_htid(tp_c) : 0x80000000;
340         root_ht->prio = tp->prio;
341 
342         if (tp_c == NULL) {
343                 tp_c = kzalloc(sizeof(*tp_c), GFP_KERNEL);
344                 if (tp_c == NULL) {
345                         kfree(root_ht);
346                         return -ENOBUFS;
347                 }
348                 tp_c->q = tp->q;
349                 tp->q->u32_node = tp_c;
350         }
351 
352         tp_c->refcnt++;
353         RCU_INIT_POINTER(root_ht->next, tp_c->hlist);
354         rcu_assign_pointer(tp_c->hlist, root_ht);
355         root_ht->tp_c = tp_c;
356 
357         rcu_assign_pointer(tp->root, root_ht);
358         tp->data = tp_c;
359         return 0;
360 }
361 
362 static int u32_destroy_key(struct tcf_proto *tp, struct tc_u_knode *n,
363                            bool free_pf)
364 {
365         tcf_exts_destroy(&n->exts);
366         if (n->ht_down)
367                 n->ht_down->refcnt--;
368 #ifdef CONFIG_CLS_U32_PERF
369         if (free_pf)
370                 free_percpu(n->pf);
371 #endif
372 #ifdef CONFIG_CLS_U32_MARK
373         if (free_pf)
374                 free_percpu(n->pcpu_success);
375 #endif
376         kfree(n);
377         return 0;
378 }
379 
380 /* u32_delete_key_rcu should be called when free'ing a copied
381  * version of a tc_u_knode obtained from u32_init_knode(). When
382  * copies are obtained from u32_init_knode() the statistics are
383  * shared between the old and new copies to allow readers to
384  * continue to update the statistics during the copy. To support
385  * this the u32_delete_key_rcu variant does not free the percpu
386  * statistics.
387  */
388 static void u32_delete_key_rcu(struct rcu_head *rcu)
389 {
390         struct tc_u_knode *key = container_of(rcu, struct tc_u_knode, rcu);
391 
392         u32_destroy_key(key->tp, key, false);
393 }
394 
395 /* u32_delete_key_freepf_rcu is the rcu callback variant
396  * that free's the entire structure including the statistics
397  * percpu variables. Only use this if the key is not a copy
398  * returned by u32_init_knode(). See u32_delete_key_rcu()
399  * for the variant that should be used with keys return from
400  * u32_init_knode()
401  */
402 static void u32_delete_key_freepf_rcu(struct rcu_head *rcu)
403 {
404         struct tc_u_knode *key = container_of(rcu, struct tc_u_knode, rcu);
405 
406         u32_destroy_key(key->tp, key, true);
407 }
408 
409 static int u32_delete_key(struct tcf_proto *tp, struct tc_u_knode *key)
410 {
411         struct tc_u_knode __rcu **kp;
412         struct tc_u_knode *pkp;
413         struct tc_u_hnode *ht = rtnl_dereference(key->ht_up);
414 
415         if (ht) {
416                 kp = &ht->ht[TC_U32_HASH(key->handle)];
417                 for (pkp = rtnl_dereference(*kp); pkp;
418                      kp = &pkp->next, pkp = rtnl_dereference(*kp)) {
419                         if (pkp == key) {
420                                 RCU_INIT_POINTER(*kp, key->next);
421 
422                                 tcf_unbind_filter(tp, &key->res);
423                                 call_rcu(&key->rcu, u32_delete_key_freepf_rcu);
424                                 return 0;
425                         }
426                 }
427         }
428         WARN_ON(1);
429         return 0;
430 }
431 
432 static void u32_remove_hw_knode(struct tcf_proto *tp, u32 handle)
433 {
434         struct net_device *dev = tp->q->dev_queue->dev;
435         struct tc_cls_u32_offload u32_offload = {0};
436         struct tc_to_netdev offload;
437 
438         offload.type = TC_SETUP_CLSU32;
439         offload.cls_u32 = &u32_offload;
440 
441         if (tc_should_offload(dev, tp, 0)) {
442                 offload.cls_u32->command = TC_CLSU32_DELETE_KNODE;
443                 offload.cls_u32->knode.handle = handle;
444                 dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
445                                               tp->protocol, &offload);
446         }
447 }
448 
449 static int u32_replace_hw_hnode(struct tcf_proto *tp, struct tc_u_hnode *h,
450                                 u32 flags)
451 {
452         struct net_device *dev = tp->q->dev_queue->dev;
453         struct tc_cls_u32_offload u32_offload = {0};
454         struct tc_to_netdev offload;
455         int err;
456 
457         if (!tc_should_offload(dev, tp, flags))
458                 return tc_skip_sw(flags) ? -EINVAL : 0;
459 
460         offload.type = TC_SETUP_CLSU32;
461         offload.cls_u32 = &u32_offload;
462 
463         offload.cls_u32->command = TC_CLSU32_NEW_HNODE;
464         offload.cls_u32->hnode.divisor = h->divisor;
465         offload.cls_u32->hnode.handle = h->handle;
466         offload.cls_u32->hnode.prio = h->prio;
467 
468         err = dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
469                                             tp->protocol, &offload);
470         if (tc_skip_sw(flags))
471                 return err;
472 
473         return 0;
474 }
475 
476 static void u32_clear_hw_hnode(struct tcf_proto *tp, struct tc_u_hnode *h)
477 {
478         struct net_device *dev = tp->q->dev_queue->dev;
479         struct tc_cls_u32_offload u32_offload = {0};
480         struct tc_to_netdev offload;
481 
482         offload.type = TC_SETUP_CLSU32;
483         offload.cls_u32 = &u32_offload;
484 
485         if (tc_should_offload(dev, tp, 0)) {
486                 offload.cls_u32->command = TC_CLSU32_DELETE_HNODE;
487                 offload.cls_u32->hnode.divisor = h->divisor;
488                 offload.cls_u32->hnode.handle = h->handle;
489                 offload.cls_u32->hnode.prio = h->prio;
490 
491                 dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
492                                               tp->protocol, &offload);
493         }
494 }
495 
496 static int u32_replace_hw_knode(struct tcf_proto *tp, struct tc_u_knode *n,
497                                 u32 flags)
498 {
499         struct net_device *dev = tp->q->dev_queue->dev;
500         struct tc_cls_u32_offload u32_offload = {0};
501         struct tc_to_netdev offload;
502         int err;
503 
504         offload.type = TC_SETUP_CLSU32;
505         offload.cls_u32 = &u32_offload;
506 
507         if (!tc_should_offload(dev, tp, flags))
508                 return tc_skip_sw(flags) ? -EINVAL : 0;
509 
510         offload.cls_u32->command = TC_CLSU32_REPLACE_KNODE;
511         offload.cls_u32->knode.handle = n->handle;
512         offload.cls_u32->knode.fshift = n->fshift;
513 #ifdef CONFIG_CLS_U32_MARK
514         offload.cls_u32->knode.val = n->val;
515         offload.cls_u32->knode.mask = n->mask;
516 #else
517         offload.cls_u32->knode.val = 0;
518         offload.cls_u32->knode.mask = 0;
519 #endif
520         offload.cls_u32->knode.sel = &n->sel;
521         offload.cls_u32->knode.exts = &n->exts;
522         if (n->ht_down)
523                 offload.cls_u32->knode.link_handle = n->ht_down->handle;
524 
525         err = dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
526                                             tp->protocol, &offload);
527         if (tc_skip_sw(flags))
528                 return err;
529 
530         return 0;
531 }
532 
533 static void u32_clear_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
534 {
535         struct tc_u_knode *n;
536         unsigned int h;
537 
538         for (h = 0; h <= ht->divisor; h++) {
539                 while ((n = rtnl_dereference(ht->ht[h])) != NULL) {
540                         RCU_INIT_POINTER(ht->ht[h],
541                                          rtnl_dereference(n->next));
542                         tcf_unbind_filter(tp, &n->res);
543                         u32_remove_hw_knode(tp, n->handle);
544                         call_rcu(&n->rcu, u32_delete_key_freepf_rcu);
545                 }
546         }
547 }
548 
549 static int u32_destroy_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
550 {
551         struct tc_u_common *tp_c = tp->data;
552         struct tc_u_hnode __rcu **hn;
553         struct tc_u_hnode *phn;
554 
555         WARN_ON(ht->refcnt);
556 
557         u32_clear_hnode(tp, ht);
558 
559         hn = &tp_c->hlist;
560         for (phn = rtnl_dereference(*hn);
561              phn;
562              hn = &phn->next, phn = rtnl_dereference(*hn)) {
563                 if (phn == ht) {
564                         u32_clear_hw_hnode(tp, ht);
565                         RCU_INIT_POINTER(*hn, ht->next);
566                         kfree_rcu(ht, rcu);
567                         return 0;
568                 }
569         }
570 
571         return -ENOENT;
572 }
573 
574 static bool ht_empty(struct tc_u_hnode *ht)
575 {
576         unsigned int h;
577 
578         for (h = 0; h <= ht->divisor; h++)
579                 if (rcu_access_pointer(ht->ht[h]))
580                         return false;
581 
582         return true;
583 }
584 
585 static bool u32_destroy(struct tcf_proto *tp, bool force)
586 {
587         struct tc_u_common *tp_c = tp->data;
588         struct tc_u_hnode *root_ht = rtnl_dereference(tp->root);
589 
590         WARN_ON(root_ht == NULL);
591 
592         if (!force) {
593                 if (root_ht) {
594                         if (root_ht->refcnt > 1)
595                                 return false;
596                         if (root_ht->refcnt == 1) {
597                                 if (!ht_empty(root_ht))
598                                         return false;
599                         }
600                 }
601 
602                 if (tp_c->refcnt > 1)
603                         return false;
604 
605                 if (tp_c->refcnt == 1) {
606                         struct tc_u_hnode *ht;
607 
608                         for (ht = rtnl_dereference(tp_c->hlist);
609                              ht;
610                              ht = rtnl_dereference(ht->next))
611                                 if (!ht_empty(ht))
612                                         return false;
613                 }
614         }
615 
616         if (root_ht && --root_ht->refcnt == 0)
617                 u32_destroy_hnode(tp, root_ht);
618 
619         if (--tp_c->refcnt == 0) {
620                 struct tc_u_hnode *ht;
621 
622                 tp->q->u32_node = NULL;
623 
624                 for (ht = rtnl_dereference(tp_c->hlist);
625                      ht;
626                      ht = rtnl_dereference(ht->next)) {
627                         ht->refcnt--;
628                         u32_clear_hnode(tp, ht);
629                 }
630 
631                 while ((ht = rtnl_dereference(tp_c->hlist)) != NULL) {
632                         RCU_INIT_POINTER(tp_c->hlist, ht->next);
633                         kfree_rcu(ht, rcu);
634                 }
635 
636                 kfree(tp_c);
637         }
638 
639         tp->data = NULL;
640         return true;
641 }
642 
643 static int u32_delete(struct tcf_proto *tp, unsigned long arg)
644 {
645         struct tc_u_hnode *ht = (struct tc_u_hnode *)arg;
646         struct tc_u_hnode *root_ht = rtnl_dereference(tp->root);
647 
648         if (ht == NULL)
649                 return 0;
650 
651         if (TC_U32_KEY(ht->handle)) {
652                 u32_remove_hw_knode(tp, ht->handle);
653                 return u32_delete_key(tp, (struct tc_u_knode *)ht);
654         }
655 
656         if (root_ht == ht)
657                 return -EINVAL;
658 
659         if (ht->refcnt == 1) {
660                 ht->refcnt--;
661                 u32_destroy_hnode(tp, ht);
662         } else {
663                 return -EBUSY;
664         }
665 
666         return 0;
667 }
668 
669 #define NR_U32_NODE (1<<12)
670 static u32 gen_new_kid(struct tc_u_hnode *ht, u32 handle)
671 {
672         struct tc_u_knode *n;
673         unsigned long i;
674         unsigned long *bitmap = kzalloc(BITS_TO_LONGS(NR_U32_NODE) * sizeof(unsigned long),
675                                         GFP_KERNEL);
676         if (!bitmap)
677                 return handle | 0xFFF;
678 
679         for (n = rtnl_dereference(ht->ht[TC_U32_HASH(handle)]);
680              n;
681              n = rtnl_dereference(n->next))
682                 set_bit(TC_U32_NODE(n->handle), bitmap);
683 
684         i = find_next_zero_bit(bitmap, NR_U32_NODE, 0x800);
685         if (i >= NR_U32_NODE)
686                 i = find_next_zero_bit(bitmap, NR_U32_NODE, 1);
687 
688         kfree(bitmap);
689         return handle | (i >= NR_U32_NODE ? 0xFFF : i);
690 }
691 
692 static const struct nla_policy u32_policy[TCA_U32_MAX + 1] = {
693         [TCA_U32_CLASSID]       = { .type = NLA_U32 },
694         [TCA_U32_HASH]          = { .type = NLA_U32 },
695         [TCA_U32_LINK]          = { .type = NLA_U32 },
696         [TCA_U32_DIVISOR]       = { .type = NLA_U32 },
697         [TCA_U32_SEL]           = { .len = sizeof(struct tc_u32_sel) },
698         [TCA_U32_INDEV]         = { .type = NLA_STRING, .len = IFNAMSIZ },
699         [TCA_U32_MARK]          = { .len = sizeof(struct tc_u32_mark) },
700         [TCA_U32_FLAGS]         = { .type = NLA_U32 },
701 };
702 
703 static int u32_set_parms(struct net *net, struct tcf_proto *tp,
704                          unsigned long base, struct tc_u_hnode *ht,
705                          struct tc_u_knode *n, struct nlattr **tb,
706                          struct nlattr *est, bool ovr)
707 {
708         struct tcf_exts e;
709         int err;
710 
711         err = tcf_exts_init(&e, TCA_U32_ACT, TCA_U32_POLICE);
712         if (err < 0)
713                 return err;
714         err = tcf_exts_validate(net, tp, tb, est, &e, ovr);
715         if (err < 0)
716                 goto errout;
717 
718         err = -EINVAL;
719         if (tb[TCA_U32_LINK]) {
720                 u32 handle = nla_get_u32(tb[TCA_U32_LINK]);
721                 struct tc_u_hnode *ht_down = NULL, *ht_old;
722 
723                 if (TC_U32_KEY(handle))
724                         goto errout;
725 
726                 if (handle) {
727                         ht_down = u32_lookup_ht(ht->tp_c, handle);
728 
729                         if (ht_down == NULL)
730                                 goto errout;
731                         ht_down->refcnt++;
732                 }
733 
734                 ht_old = rtnl_dereference(n->ht_down);
735                 rcu_assign_pointer(n->ht_down, ht_down);
736 
737                 if (ht_old)
738                         ht_old->refcnt--;
739         }
740         if (tb[TCA_U32_CLASSID]) {
741                 n->res.classid = nla_get_u32(tb[TCA_U32_CLASSID]);
742                 tcf_bind_filter(tp, &n->res, base);
743         }
744 
745 #ifdef CONFIG_NET_CLS_IND
746         if (tb[TCA_U32_INDEV]) {
747                 int ret;
748                 ret = tcf_change_indev(net, tb[TCA_U32_INDEV]);
749                 if (ret < 0)
750                         goto errout;
751                 n->ifindex = ret;
752         }
753 #endif
754         tcf_exts_change(tp, &n->exts, &e);
755 
756         return 0;
757 errout:
758         tcf_exts_destroy(&e);
759         return err;
760 }
761 
762 static void u32_replace_knode(struct tcf_proto *tp, struct tc_u_common *tp_c,
763                               struct tc_u_knode *n)
764 {
765         struct tc_u_knode __rcu **ins;
766         struct tc_u_knode *pins;
767         struct tc_u_hnode *ht;
768 
769         if (TC_U32_HTID(n->handle) == TC_U32_ROOT)
770                 ht = rtnl_dereference(tp->root);
771         else
772                 ht = u32_lookup_ht(tp_c, TC_U32_HTID(n->handle));
773 
774         ins = &ht->ht[TC_U32_HASH(n->handle)];
775 
776         /* The node must always exist for it to be replaced if this is not the
777          * case then something went very wrong elsewhere.
778          */
779         for (pins = rtnl_dereference(*ins); ;
780              ins = &pins->next, pins = rtnl_dereference(*ins))
781                 if (pins->handle == n->handle)
782                         break;
783 
784         RCU_INIT_POINTER(n->next, pins->next);
785         rcu_assign_pointer(*ins, n);
786 }
787 
788 static struct tc_u_knode *u32_init_knode(struct tcf_proto *tp,
789                                          struct tc_u_knode *n)
790 {
791         struct tc_u_knode *new;
792         struct tc_u32_sel *s = &n->sel;
793 
794         new = kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key),
795                       GFP_KERNEL);
796 
797         if (!new)
798                 return NULL;
799 
800         RCU_INIT_POINTER(new->next, n->next);
801         new->handle = n->handle;
802         RCU_INIT_POINTER(new->ht_up, n->ht_up);
803 
804 #ifdef CONFIG_NET_CLS_IND
805         new->ifindex = n->ifindex;
806 #endif
807         new->fshift = n->fshift;
808         new->res = n->res;
809         new->flags = n->flags;
810         RCU_INIT_POINTER(new->ht_down, n->ht_down);
811 
812         /* bump reference count as long as we hold pointer to structure */
813         if (new->ht_down)
814                 new->ht_down->refcnt++;
815 
816 #ifdef CONFIG_CLS_U32_PERF
817         /* Statistics may be incremented by readers during update
818          * so we must keep them in tact. When the node is later destroyed
819          * a special destroy call must be made to not free the pf memory.
820          */
821         new->pf = n->pf;
822 #endif
823 
824 #ifdef CONFIG_CLS_U32_MARK
825         new->val = n->val;
826         new->mask = n->mask;
827         /* Similarly success statistics must be moved as pointers */
828         new->pcpu_success = n->pcpu_success;
829 #endif
830         new->tp = tp;
831         memcpy(&new->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
832 
833         if (tcf_exts_init(&new->exts, TCA_U32_ACT, TCA_U32_POLICE)) {
834                 kfree(new);
835                 return NULL;
836         }
837 
838         return new;
839 }
840 
841 static int u32_change(struct net *net, struct sk_buff *in_skb,
842                       struct tcf_proto *tp, unsigned long base, u32 handle,
843                       struct nlattr **tca, unsigned long *arg, bool ovr)
844 {
845         struct tc_u_common *tp_c = tp->data;
846         struct tc_u_hnode *ht;
847         struct tc_u_knode *n;
848         struct tc_u32_sel *s;
849         struct nlattr *opt = tca[TCA_OPTIONS];
850         struct nlattr *tb[TCA_U32_MAX + 1];
851         u32 htid, flags = 0;
852         int err;
853 #ifdef CONFIG_CLS_U32_PERF
854         size_t size;
855 #endif
856 
857         if (opt == NULL)
858                 return handle ? -EINVAL : 0;
859 
860         err = nla_parse_nested(tb, TCA_U32_MAX, opt, u32_policy);
861         if (err < 0)
862                 return err;
863 
864         if (tb[TCA_U32_FLAGS]) {
865                 flags = nla_get_u32(tb[TCA_U32_FLAGS]);
866                 if (!tc_flags_valid(flags))
867                         return -EINVAL;
868         }
869 
870         n = (struct tc_u_knode *)*arg;
871         if (n) {
872                 struct tc_u_knode *new;
873 
874                 if (TC_U32_KEY(n->handle) == 0)
875                         return -EINVAL;
876 
877                 if (n->flags != flags)
878                         return -EINVAL;
879 
880                 new = u32_init_knode(tp, n);
881                 if (!new)
882                         return -ENOMEM;
883 
884                 err = u32_set_parms(net, tp, base,
885                                     rtnl_dereference(n->ht_up), new, tb,
886                                     tca[TCA_RATE], ovr);
887 
888                 if (err) {
889                         u32_destroy_key(tp, new, false);
890                         return err;
891                 }
892 
893                 err = u32_replace_hw_knode(tp, new, flags);
894                 if (err) {
895                         u32_destroy_key(tp, new, false);
896                         return err;
897                 }
898 
899                 u32_replace_knode(tp, tp_c, new);
900                 tcf_unbind_filter(tp, &n->res);
901                 call_rcu(&n->rcu, u32_delete_key_rcu);
902                 return 0;
903         }
904 
905         if (tb[TCA_U32_DIVISOR]) {
906                 unsigned int divisor = nla_get_u32(tb[TCA_U32_DIVISOR]);
907 
908                 if (--divisor > 0x100)
909                         return -EINVAL;
910                 if (TC_U32_KEY(handle))
911                         return -EINVAL;
912                 if (handle == 0) {
913                         handle = gen_new_htid(tp->data);
914                         if (handle == 0)
915                                 return -ENOMEM;
916                 }
917                 ht = kzalloc(sizeof(*ht) + divisor*sizeof(void *), GFP_KERNEL);
918                 if (ht == NULL)
919                         return -ENOBUFS;
920                 ht->tp_c = tp_c;
921                 ht->refcnt = 1;
922                 ht->divisor = divisor;
923                 ht->handle = handle;
924                 ht->prio = tp->prio;
925 
926                 err = u32_replace_hw_hnode(tp, ht, flags);
927                 if (err) {
928                         kfree(ht);
929                         return err;
930                 }
931 
932                 RCU_INIT_POINTER(ht->next, tp_c->hlist);
933                 rcu_assign_pointer(tp_c->hlist, ht);
934                 *arg = (unsigned long)ht;
935 
936                 return 0;
937         }
938 
939         if (tb[TCA_U32_HASH]) {
940                 htid = nla_get_u32(tb[TCA_U32_HASH]);
941                 if (TC_U32_HTID(htid) == TC_U32_ROOT) {
942                         ht = rtnl_dereference(tp->root);
943                         htid = ht->handle;
944                 } else {
945                         ht = u32_lookup_ht(tp->data, TC_U32_HTID(htid));
946                         if (ht == NULL)
947                                 return -EINVAL;
948                 }
949         } else {
950                 ht = rtnl_dereference(tp->root);
951                 htid = ht->handle;
952         }
953 
954         if (ht->divisor < TC_U32_HASH(htid))
955                 return -EINVAL;
956 
957         if (handle) {
958                 if (TC_U32_HTID(handle) && TC_U32_HTID(handle^htid))
959                         return -EINVAL;
960                 handle = htid | TC_U32_NODE(handle);
961         } else
962                 handle = gen_new_kid(ht, htid);
963 
964         if (tb[TCA_U32_SEL] == NULL)
965                 return -EINVAL;
966 
967         s = nla_data(tb[TCA_U32_SEL]);
968 
969         n = kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key), GFP_KERNEL);
970         if (n == NULL)
971                 return -ENOBUFS;
972 
973 #ifdef CONFIG_CLS_U32_PERF
974         size = sizeof(struct tc_u32_pcnt) + s->nkeys * sizeof(u64);
975         n->pf = __alloc_percpu(size, __alignof__(struct tc_u32_pcnt));
976         if (!n->pf) {
977                 kfree(n);
978                 return -ENOBUFS;
979         }
980 #endif
981 
982         memcpy(&n->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
983         RCU_INIT_POINTER(n->ht_up, ht);
984         n->handle = handle;
985         n->fshift = s->hmask ? ffs(ntohl(s->hmask)) - 1 : 0;
986         n->flags = flags;
987         n->tp = tp;
988 
989         err = tcf_exts_init(&n->exts, TCA_U32_ACT, TCA_U32_POLICE);
990         if (err < 0)
991                 goto errout;
992 
993 #ifdef CONFIG_CLS_U32_MARK
994         n->pcpu_success = alloc_percpu(u32);
995         if (!n->pcpu_success) {
996                 err = -ENOMEM;
997                 goto errout;
998         }
999 
1000         if (tb[TCA_U32_MARK]) {
1001                 struct tc_u32_mark *mark;
1002 
1003                 mark = nla_data(tb[TCA_U32_MARK]);
1004                 n->val = mark->val;
1005                 n->mask = mark->mask;
1006         }
1007 #endif
1008 
1009         err = u32_set_parms(net, tp, base, ht, n, tb, tca[TCA_RATE], ovr);
1010         if (err == 0) {
1011                 struct tc_u_knode __rcu **ins;
1012                 struct tc_u_knode *pins;
1013 
1014                 err = u32_replace_hw_knode(tp, n, flags);
1015                 if (err)
1016                         goto errhw;
1017 
1018                 ins = &ht->ht[TC_U32_HASH(handle)];
1019                 for (pins = rtnl_dereference(*ins); pins;
1020                      ins = &pins->next, pins = rtnl_dereference(*ins))
1021                         if (TC_U32_NODE(handle) < TC_U32_NODE(pins->handle))
1022                                 break;
1023 
1024                 RCU_INIT_POINTER(n->next, pins);
1025                 rcu_assign_pointer(*ins, n);
1026                 *arg = (unsigned long)n;
1027                 return 0;
1028         }
1029 
1030 errhw:
1031 #ifdef CONFIG_CLS_U32_MARK
1032         free_percpu(n->pcpu_success);
1033 #endif
1034 
1035 errout:
1036         tcf_exts_destroy(&n->exts);
1037 #ifdef CONFIG_CLS_U32_PERF
1038         free_percpu(n->pf);
1039 #endif
1040         kfree(n);
1041         return err;
1042 }
1043 
1044 static void u32_walk(struct tcf_proto *tp, struct tcf_walker *arg)
1045 {
1046         struct tc_u_common *tp_c = tp->data;
1047         struct tc_u_hnode *ht;
1048         struct tc_u_knode *n;
1049         unsigned int h;
1050 
1051         if (arg->stop)
1052                 return;
1053 
1054         for (ht = rtnl_dereference(tp_c->hlist);
1055              ht;
1056              ht = rtnl_dereference(ht->next)) {
1057                 if (ht->prio != tp->prio)
1058                         continue;
1059                 if (arg->count >= arg->skip) {
1060                         if (arg->fn(tp, (unsigned long)ht, arg) < 0) {
1061                                 arg->stop = 1;
1062                                 return;
1063                         }
1064                 }
1065                 arg->count++;
1066                 for (h = 0; h <= ht->divisor; h++) {
1067                         for (n = rtnl_dereference(ht->ht[h]);
1068                              n;
1069                              n = rtnl_dereference(n->next)) {
1070                                 if (arg->count < arg->skip) {
1071                                         arg->count++;
1072                                         continue;
1073                                 }
1074                                 if (arg->fn(tp, (unsigned long)n, arg) < 0) {
1075                                         arg->stop = 1;
1076                                         return;
1077                                 }
1078                                 arg->count++;
1079                         }
1080                 }
1081         }
1082 }
1083 
1084 static int u32_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
1085                     struct sk_buff *skb, struct tcmsg *t)
1086 {
1087         struct tc_u_knode *n = (struct tc_u_knode *)fh;
1088         struct tc_u_hnode *ht_up, *ht_down;
1089         struct nlattr *nest;
1090 
1091         if (n == NULL)
1092                 return skb->len;
1093 
1094         t->tcm_handle = n->handle;
1095 
1096         nest = nla_nest_start(skb, TCA_OPTIONS);
1097         if (nest == NULL)
1098                 goto nla_put_failure;
1099 
1100         if (TC_U32_KEY(n->handle) == 0) {
1101                 struct tc_u_hnode *ht = (struct tc_u_hnode *)fh;
1102                 u32 divisor = ht->divisor + 1;
1103 
1104                 if (nla_put_u32(skb, TCA_U32_DIVISOR, divisor))
1105                         goto nla_put_failure;
1106         } else {
1107 #ifdef CONFIG_CLS_U32_PERF
1108                 struct tc_u32_pcnt *gpf;
1109                 int cpu;
1110 #endif
1111 
1112                 if (nla_put(skb, TCA_U32_SEL,
1113                             sizeof(n->sel) + n->sel.nkeys*sizeof(struct tc_u32_key),
1114                             &n->sel))
1115                         goto nla_put_failure;
1116 
1117                 ht_up = rtnl_dereference(n->ht_up);
1118                 if (ht_up) {
1119                         u32 htid = n->handle & 0xFFFFF000;
1120                         if (nla_put_u32(skb, TCA_U32_HASH, htid))
1121                                 goto nla_put_failure;
1122                 }
1123                 if (n->res.classid &&
1124                     nla_put_u32(skb, TCA_U32_CLASSID, n->res.classid))
1125                         goto nla_put_failure;
1126 
1127                 ht_down = rtnl_dereference(n->ht_down);
1128                 if (ht_down &&
1129                     nla_put_u32(skb, TCA_U32_LINK, ht_down->handle))
1130                         goto nla_put_failure;
1131 
1132                 if (n->flags && nla_put_u32(skb, TCA_U32_FLAGS, n->flags))
1133                         goto nla_put_failure;
1134 
1135 #ifdef CONFIG_CLS_U32_MARK
1136                 if ((n->val || n->mask)) {
1137                         struct tc_u32_mark mark = {.val = n->val,
1138                                                    .mask = n->mask,
1139                                                    .success = 0};
1140                         int cpum;
1141 
1142                         for_each_possible_cpu(cpum) {
1143                                 __u32 cnt = *per_cpu_ptr(n->pcpu_success, cpum);
1144 
1145                                 mark.success += cnt;
1146                         }
1147 
1148                         if (nla_put(skb, TCA_U32_MARK, sizeof(mark), &mark))
1149                                 goto nla_put_failure;
1150                 }
1151 #endif
1152 
1153                 if (tcf_exts_dump(skb, &n->exts) < 0)
1154                         goto nla_put_failure;
1155 
1156 #ifdef CONFIG_NET_CLS_IND
1157                 if (n->ifindex) {
1158                         struct net_device *dev;
1159                         dev = __dev_get_by_index(net, n->ifindex);
1160                         if (dev && nla_put_string(skb, TCA_U32_INDEV, dev->name))
1161                                 goto nla_put_failure;
1162                 }
1163 #endif
1164 #ifdef CONFIG_CLS_U32_PERF
1165                 gpf = kzalloc(sizeof(struct tc_u32_pcnt) +
1166                               n->sel.nkeys * sizeof(u64),
1167                               GFP_KERNEL);
1168                 if (!gpf)
1169                         goto nla_put_failure;
1170 
1171                 for_each_possible_cpu(cpu) {
1172                         int i;
1173                         struct tc_u32_pcnt *pf = per_cpu_ptr(n->pf, cpu);
1174 
1175                         gpf->rcnt += pf->rcnt;
1176                         gpf->rhit += pf->rhit;
1177                         for (i = 0; i < n->sel.nkeys; i++)
1178                                 gpf->kcnts[i] += pf->kcnts[i];
1179                 }
1180 
1181                 if (nla_put_64bit(skb, TCA_U32_PCNT,
1182                                   sizeof(struct tc_u32_pcnt) +
1183                                   n->sel.nkeys * sizeof(u64),
1184                                   gpf, TCA_U32_PAD)) {
1185                         kfree(gpf);
1186                         goto nla_put_failure;
1187                 }
1188                 kfree(gpf);
1189 #endif
1190         }
1191 
1192         nla_nest_end(skb, nest);
1193 
1194         if (TC_U32_KEY(n->handle))
1195                 if (tcf_exts_dump_stats(skb, &n->exts) < 0)
1196                         goto nla_put_failure;
1197         return skb->len;
1198 
1199 nla_put_failure:
1200         nla_nest_cancel(skb, nest);
1201         return -1;
1202 }
1203 
1204 static struct tcf_proto_ops cls_u32_ops __read_mostly = {
1205         .kind           =       "u32",
1206         .classify       =       u32_classify,
1207         .init           =       u32_init,
1208         .destroy        =       u32_destroy,
1209         .get            =       u32_get,
1210         .change         =       u32_change,
1211         .delete         =       u32_delete,
1212         .walk           =       u32_walk,
1213         .dump           =       u32_dump,
1214         .owner          =       THIS_MODULE,
1215 };
1216 
1217 static int __init init_u32(void)
1218 {
1219         pr_info("u32 classifier\n");
1220 #ifdef CONFIG_CLS_U32_PERF
1221         pr_info("    Performance counters on\n");
1222 #endif
1223 #ifdef CONFIG_NET_CLS_IND
1224         pr_info("    input device check on\n");
1225 #endif
1226 #ifdef CONFIG_NET_CLS_ACT
1227         pr_info("    Actions configured\n");
1228 #endif
1229         return register_tcf_proto_ops(&cls_u32_ops);
1230 }
1231 
1232 static void __exit exit_u32(void)
1233 {
1234         unregister_tcf_proto_ops(&cls_u32_ops);
1235 }
1236 
1237 module_init(init_u32)
1238 module_exit(exit_u32)
1239 MODULE_LICENSE("GPL");
1240 

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