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bpf: Prevent memory disambiguation attack
[linux/fpc-iii.git] / net / sched / cls_u32.c
blobbac47b5d18fdbd6bca9e3a39822db67be946b21b
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 <linux/netdevice.h>
44 #include <linux/hash.h>
45 #include <net/netlink.h>
46 #include <net/act_api.h>
47 #include <net/pkt_cls.h>
48 #include <linux/idr.h>
49
50 struct tc_u_knode {
51 struct tc_u_knode __rcu *next;
52 u32 handle;
53 struct tc_u_hnode __rcu *ht_up;
54 struct tcf_exts exts;
55 #ifdef CONFIG_NET_CLS_IND
56 int ifindex;
57 #endif
58 u8 fshift;
59 struct tcf_result res;
60 struct tc_u_hnode __rcu *ht_down;
61 #ifdef CONFIG_CLS_U32_PERF
62 struct tc_u32_pcnt __percpu *pf;
63 #endif
64 u32 flags;
65 #ifdef CONFIG_CLS_U32_MARK
66 u32 val;
67 u32 mask;
68 u32 __percpu *pcpu_success;
69 #endif
70 struct tcf_proto *tp;
71 union {
72 struct work_struct work;
73 struct rcu_head rcu;
74 };
75 /* The 'sel' field MUST be the last field in structure to allow for
76 * tc_u32_keys allocated at end of structure.
77 */
78 struct tc_u32_sel sel;
79 };
80
81 struct tc_u_hnode {
82 struct tc_u_hnode __rcu *next;
83 u32 handle;
84 u32 prio;
85 struct tc_u_common *tp_c;
86 int refcnt;
87 unsigned int divisor;
88 struct idr handle_idr;
89 struct rcu_head rcu;
90 u32 flags;
91 /* The 'ht' field MUST be the last field in structure to allow for
92 * more entries allocated at end of structure.
93 */
94 struct tc_u_knode __rcu *ht[1];
95 };
96
97 struct tc_u_common {
98 struct tc_u_hnode __rcu *hlist;
99 void *ptr;
100 int refcnt;
101 struct idr handle_idr;
102 struct hlist_node hnode;
103 struct rcu_head rcu;
104 };
105
106 static inline unsigned int u32_hash_fold(__be32 key,
107 const struct tc_u32_sel *sel,
108 u8 fshift)
109 {
110 unsigned int h = ntohl(key & sel->hmask) >> fshift;
111
112 return h;
113 }
114
115 static int u32_classify(struct sk_buff *skb, const struct tcf_proto *tp,
116 struct tcf_result *res)
117 {
118 struct {
119 struct tc_u_knode *knode;
120 unsigned int off;
121 } stack[TC_U32_MAXDEPTH];
122
123 struct tc_u_hnode *ht = rcu_dereference_bh(tp->root);
124 unsigned int off = skb_network_offset(skb);
125 struct tc_u_knode *n;
126 int sdepth = 0;
127 int off2 = 0;
128 int sel = 0;
129 #ifdef CONFIG_CLS_U32_PERF
130 int j;
131 #endif
132 int i, r;
133
134 next_ht:
135 n = rcu_dereference_bh(ht->ht[sel]);
136
137 next_knode:
138 if (n) {
139 struct tc_u32_key *key = n->sel.keys;
140
141 #ifdef CONFIG_CLS_U32_PERF
142 __this_cpu_inc(n->pf->rcnt);
143 j = 0;
144 #endif
145
146 if (tc_skip_sw(n->flags)) {
147 n = rcu_dereference_bh(n->next);
148 goto next_knode;
149 }
150
151 #ifdef CONFIG_CLS_U32_MARK
152 if ((skb->mark & n->mask) != n->val) {
153 n = rcu_dereference_bh(n->next);
154 goto next_knode;
155 } else {
156 __this_cpu_inc(*n->pcpu_success);
157 }
158 #endif
159
160 for (i = n->sel.nkeys; i > 0; i--, key++) {
161 int toff = off + key->off + (off2 & key->offmask);
162 __be32 *data, hdata;
163
164 if (skb_headroom(skb) + toff > INT_MAX)
165 goto out;
166
167 data = skb_header_pointer(skb, toff, 4, &hdata);
168 if (!data)
169 goto out;
170 if ((*data ^ key->val) & key->mask) {
171 n = rcu_dereference_bh(n->next);
172 goto next_knode;
173 }
174 #ifdef CONFIG_CLS_U32_PERF
175 __this_cpu_inc(n->pf->kcnts[j]);
176 j++;
177 #endif
178 }
179
180 ht = rcu_dereference_bh(n->ht_down);
181 if (!ht) {
182 check_terminal:
183 if (n->sel.flags & TC_U32_TERMINAL) {
184
185 *res = n->res;
186 #ifdef CONFIG_NET_CLS_IND
187 if (!tcf_match_indev(skb, n->ifindex)) {
188 n = rcu_dereference_bh(n->next);
189 goto next_knode;
190 }
191 #endif
192 #ifdef CONFIG_CLS_U32_PERF
193 __this_cpu_inc(n->pf->rhit);
194 #endif
195 r = tcf_exts_exec(skb, &n->exts, res);
196 if (r < 0) {
197 n = rcu_dereference_bh(n->next);
198 goto next_knode;
199 }
200
201 return r;
202 }
203 n = rcu_dereference_bh(n->next);
204 goto next_knode;
205 }
206
207 /* PUSH */
208 if (sdepth >= TC_U32_MAXDEPTH)
209 goto deadloop;
210 stack[sdepth].knode = n;
211 stack[sdepth].off = off;
212 sdepth++;
213
214 ht = rcu_dereference_bh(n->ht_down);
215 sel = 0;
216 if (ht->divisor) {
217 __be32 *data, hdata;
218
219 data = skb_header_pointer(skb, off + n->sel.hoff, 4,
220 &hdata);
221 if (!data)
222 goto out;
223 sel = ht->divisor & u32_hash_fold(*data, &n->sel,
224 n->fshift);
225 }
226 if (!(n->sel.flags & (TC_U32_VAROFFSET | TC_U32_OFFSET | TC_U32_EAT)))
227 goto next_ht;
228
229 if (n->sel.flags & (TC_U32_OFFSET | TC_U32_VAROFFSET)) {
230 off2 = n->sel.off + 3;
231 if (n->sel.flags & TC_U32_VAROFFSET) {
232 __be16 *data, hdata;
233
234 data = skb_header_pointer(skb,
235 off + n->sel.offoff,
236 2, &hdata);
237 if (!data)
238 goto out;
239 off2 += ntohs(n->sel.offmask & *data) >>
240 n->sel.offshift;
241 }
242 off2 &= ~3;
243 }
244 if (n->sel.flags & TC_U32_EAT) {
245 off += off2;
246 off2 = 0;
247 }
248
249 if (off < skb->len)
250 goto next_ht;
251 }
252
253 /* POP */
254 if (sdepth--) {
255 n = stack[sdepth].knode;
256 ht = rcu_dereference_bh(n->ht_up);
257 off = stack[sdepth].off;
258 goto check_terminal;
259 }
260 out:
261 return -1;
262
263 deadloop:
264 net_warn_ratelimited("cls_u32: dead loop\n");
265 return -1;
266 }
267
268 static struct tc_u_hnode *u32_lookup_ht(struct tc_u_common *tp_c, u32 handle)
269 {
270 struct tc_u_hnode *ht;
271
272 for (ht = rtnl_dereference(tp_c->hlist);
273 ht;
274 ht = rtnl_dereference(ht->next))
275 if (ht->handle == handle)
276 break;
277
278 return ht;
279 }
280
281 static struct tc_u_knode *u32_lookup_key(struct tc_u_hnode *ht, u32 handle)
282 {
283 unsigned int sel;
284 struct tc_u_knode *n = NULL;
285
286 sel = TC_U32_HASH(handle);
287 if (sel > ht->divisor)
288 goto out;
289
290 for (n = rtnl_dereference(ht->ht[sel]);
291 n;
292 n = rtnl_dereference(n->next))
293 if (n->handle == handle)
294 break;
295 out:
296 return n;
297 }
298
299
300 static void *u32_get(struct tcf_proto *tp, u32 handle)
301 {
302 struct tc_u_hnode *ht;
303 struct tc_u_common *tp_c = tp->data;
304
305 if (TC_U32_HTID(handle) == TC_U32_ROOT)
306 ht = rtnl_dereference(tp->root);
307 else
308 ht = u32_lookup_ht(tp_c, TC_U32_HTID(handle));
309
310 if (!ht)
311 return NULL;
312
313 if (TC_U32_KEY(handle) == 0)
314 return ht;
315
316 return u32_lookup_key(ht, handle);
317 }
318
319 /* Protected by rtnl lock */
320 static u32 gen_new_htid(struct tc_u_common *tp_c, struct tc_u_hnode *ptr)
321 {
322 int id = idr_alloc_cyclic(&tp_c->handle_idr, ptr, 1, 0x7FF, GFP_KERNEL);
323 if (id < 0)
324 return 0;
325 return (id | 0x800U) << 20;
326 }
327
328 static struct hlist_head *tc_u_common_hash;
329
330 #define U32_HASH_SHIFT 10
331 #define U32_HASH_SIZE (1 << U32_HASH_SHIFT)
332
333 static void *tc_u_common_ptr(const struct tcf_proto *tp)
334 {
335 struct tcf_block *block = tp->chain->block;
336
337 /* The block sharing is currently supported only
338 * for classless qdiscs. In that case we use block
339 * for tc_u_common identification. In case the
340 * block is not shared, block->q is a valid pointer
341 * and we can use that. That works for classful qdiscs.
342 */
343 if (tcf_block_shared(block))
344 return block;
345 else
346 return block->q;
347 }
348
349 static unsigned int tc_u_hash(const struct tcf_proto *tp)
350 {
351 return hash_ptr(tc_u_common_ptr(tp), U32_HASH_SHIFT);
352 }
353
354 static struct tc_u_common *tc_u_common_find(const struct tcf_proto *tp)
355 {
356 struct tc_u_common *tc;
357 unsigned int h;
358
359 h = tc_u_hash(tp);
360 hlist_for_each_entry(tc, &tc_u_common_hash[h], hnode) {
361 if (tc->ptr == tc_u_common_ptr(tp))
362 return tc;
363 }
364 return NULL;
365 }
366
367 static int u32_init(struct tcf_proto *tp)
368 {
369 struct tc_u_hnode *root_ht;
370 struct tc_u_common *tp_c;
371 unsigned int h;
372
373 tp_c = tc_u_common_find(tp);
374
375 root_ht = kzalloc(sizeof(*root_ht), GFP_KERNEL);
376 if (root_ht == NULL)
377 return -ENOBUFS;
378
379 root_ht->refcnt++;
380 root_ht->handle = tp_c ? gen_new_htid(tp_c, root_ht) : 0x80000000;
381 root_ht->prio = tp->prio;
382 idr_init(&root_ht->handle_idr);
383
384 if (tp_c == NULL) {
385 tp_c = kzalloc(sizeof(*tp_c), GFP_KERNEL);
386 if (tp_c == NULL) {
387 kfree(root_ht);
388 return -ENOBUFS;
389 }
390 tp_c->ptr = tc_u_common_ptr(tp);
391 INIT_HLIST_NODE(&tp_c->hnode);
392 idr_init(&tp_c->handle_idr);
393
394 h = tc_u_hash(tp);
395 hlist_add_head(&tp_c->hnode, &tc_u_common_hash[h]);
396 }
397
398 tp_c->refcnt++;
399 RCU_INIT_POINTER(root_ht->next, tp_c->hlist);
400 rcu_assign_pointer(tp_c->hlist, root_ht);
401 root_ht->tp_c = tp_c;
402
403 rcu_assign_pointer(tp->root, root_ht);
404 tp->data = tp_c;
405 return 0;
406 }
407
408 static int u32_destroy_key(struct tcf_proto *tp, struct tc_u_knode *n,
409 bool free_pf)
410 {
411 struct tc_u_hnode *ht = rtnl_dereference(n->ht_down);
412
413 tcf_exts_destroy(&n->exts);
414 tcf_exts_put_net(&n->exts);
415 if (ht && --ht->refcnt == 0)
416 kfree(ht);
417 #ifdef CONFIG_CLS_U32_PERF
418 if (free_pf)
419 free_percpu(n->pf);
420 #endif
421 #ifdef CONFIG_CLS_U32_MARK
422 if (free_pf)
423 free_percpu(n->pcpu_success);
424 #endif
425 kfree(n);
426 return 0;
427 }
428
429 /* u32_delete_key_rcu should be called when free'ing a copied
430 * version of a tc_u_knode obtained from u32_init_knode(). When
431 * copies are obtained from u32_init_knode() the statistics are
432 * shared between the old and new copies to allow readers to
433 * continue to update the statistics during the copy. To support
434 * this the u32_delete_key_rcu variant does not free the percpu
435 * statistics.
436 */
437 static void u32_delete_key_work(struct work_struct *work)
438 {
439 struct tc_u_knode *key = container_of(work, struct tc_u_knode, work);
440
441 rtnl_lock();
442 u32_destroy_key(key->tp, key, false);
443 rtnl_unlock();
444 }
445
446 static void u32_delete_key_rcu(struct rcu_head *rcu)
447 {
448 struct tc_u_knode *key = container_of(rcu, struct tc_u_knode, rcu);
449
450 INIT_WORK(&key->work, u32_delete_key_work);
451 tcf_queue_work(&key->work);
452 }
453
454 /* u32_delete_key_freepf_rcu is the rcu callback variant
455 * that free's the entire structure including the statistics
456 * percpu variables. Only use this if the key is not a copy
457 * returned by u32_init_knode(). See u32_delete_key_rcu()
458 * for the variant that should be used with keys return from
459 * u32_init_knode()
460 */
461 static void u32_delete_key_freepf_work(struct work_struct *work)
462 {
463 struct tc_u_knode *key = container_of(work, struct tc_u_knode, work);
464
465 rtnl_lock();
466 u32_destroy_key(key->tp, key, true);
467 rtnl_unlock();
468 }
469
470 static void u32_delete_key_freepf_rcu(struct rcu_head *rcu)
471 {
472 struct tc_u_knode *key = container_of(rcu, struct tc_u_knode, rcu);
473
474 INIT_WORK(&key->work, u32_delete_key_freepf_work);
475 tcf_queue_work(&key->work);
476 }
477
478 static int u32_delete_key(struct tcf_proto *tp, struct tc_u_knode *key)
479 {
480 struct tc_u_knode __rcu **kp;
481 struct tc_u_knode *pkp;
482 struct tc_u_hnode *ht = rtnl_dereference(key->ht_up);
483
484 if (ht) {
485 kp = &ht->ht[TC_U32_HASH(key->handle)];
486 for (pkp = rtnl_dereference(*kp); pkp;
487 kp = &pkp->next, pkp = rtnl_dereference(*kp)) {
488 if (pkp == key) {
489 RCU_INIT_POINTER(*kp, key->next);
490
491 tcf_unbind_filter(tp, &key->res);
492 idr_remove(&ht->handle_idr, key->handle);
493 tcf_exts_get_net(&key->exts);
494 call_rcu(&key->rcu, u32_delete_key_freepf_rcu);
495 return 0;
496 }
497 }
498 }
499 WARN_ON(1);
500 return 0;
501 }
502
503 static void u32_clear_hw_hnode(struct tcf_proto *tp, struct tc_u_hnode *h,
504 struct netlink_ext_ack *extack)
505 {
506 struct tcf_block *block = tp->chain->block;
507 struct tc_cls_u32_offload cls_u32 = {};
508
509 tc_cls_common_offload_init(&cls_u32.common, tp, h->flags, extack);
510 cls_u32.command = TC_CLSU32_DELETE_HNODE;
511 cls_u32.hnode.divisor = h->divisor;
512 cls_u32.hnode.handle = h->handle;
513 cls_u32.hnode.prio = h->prio;
514
515 tc_setup_cb_call(block, NULL, TC_SETUP_CLSU32, &cls_u32, false);
516 }
517
518 static int u32_replace_hw_hnode(struct tcf_proto *tp, struct tc_u_hnode *h,
519 u32 flags, struct netlink_ext_ack *extack)
520 {
521 struct tcf_block *block = tp->chain->block;
522 struct tc_cls_u32_offload cls_u32 = {};
523 bool skip_sw = tc_skip_sw(flags);
524 bool offloaded = false;
525 int err;
526
527 tc_cls_common_offload_init(&cls_u32.common, tp, flags, extack);
528 cls_u32.command = TC_CLSU32_NEW_HNODE;
529 cls_u32.hnode.divisor = h->divisor;
530 cls_u32.hnode.handle = h->handle;
531 cls_u32.hnode.prio = h->prio;
532
533 err = tc_setup_cb_call(block, NULL, TC_SETUP_CLSU32, &cls_u32, skip_sw);
534 if (err < 0) {
535 u32_clear_hw_hnode(tp, h, NULL);
536 return err;
537 } else if (err > 0) {
538 offloaded = true;
539 }
540
541 if (skip_sw && !offloaded)
542 return -EINVAL;
543
544 return 0;
545 }
546
547 static void u32_remove_hw_knode(struct tcf_proto *tp, struct tc_u_knode *n,
548 struct netlink_ext_ack *extack)
549 {
550 struct tcf_block *block = tp->chain->block;
551 struct tc_cls_u32_offload cls_u32 = {};
552
553 tc_cls_common_offload_init(&cls_u32.common, tp, n->flags, extack);
554 cls_u32.command = TC_CLSU32_DELETE_KNODE;
555 cls_u32.knode.handle = n->handle;
556
557 tc_setup_cb_call(block, NULL, TC_SETUP_CLSU32, &cls_u32, false);
558 tcf_block_offload_dec(block, &n->flags);
559 }
560
561 static int u32_replace_hw_knode(struct tcf_proto *tp, struct tc_u_knode *n,
562 u32 flags, struct netlink_ext_ack *extack)
563 {
564 struct tc_u_hnode *ht = rtnl_dereference(n->ht_down);
565 struct tcf_block *block = tp->chain->block;
566 struct tc_cls_u32_offload cls_u32 = {};
567 bool skip_sw = tc_skip_sw(flags);
568 int err;
569
570 tc_cls_common_offload_init(&cls_u32.common, tp, flags, extack);
571 cls_u32.command = TC_CLSU32_REPLACE_KNODE;
572 cls_u32.knode.handle = n->handle;
573 cls_u32.knode.fshift = n->fshift;
574 #ifdef CONFIG_CLS_U32_MARK
575 cls_u32.knode.val = n->val;
576 cls_u32.knode.mask = n->mask;
577 #else
578 cls_u32.knode.val = 0;
579 cls_u32.knode.mask = 0;
580 #endif
581 cls_u32.knode.sel = &n->sel;
582 cls_u32.knode.exts = &n->exts;
583 if (n->ht_down)
584 cls_u32.knode.link_handle = ht->handle;
585
586 err = tc_setup_cb_call(block, NULL, TC_SETUP_CLSU32, &cls_u32, skip_sw);
587 if (err < 0) {
588 u32_remove_hw_knode(tp, n, NULL);
589 return err;
590 } else if (err > 0) {
591 tcf_block_offload_inc(block, &n->flags);
592 }
593
594 if (skip_sw && !(n->flags & TCA_CLS_FLAGS_IN_HW))
595 return -EINVAL;
596
597 return 0;
598 }
599
600 static void u32_clear_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht,
601 struct netlink_ext_ack *extack)
602 {
603 struct tc_u_knode *n;
604 unsigned int h;
605
606 for (h = 0; h <= ht->divisor; h++) {
607 while ((n = rtnl_dereference(ht->ht[h])) != NULL) {
608 RCU_INIT_POINTER(ht->ht[h],
609 rtnl_dereference(n->next));
610 tcf_unbind_filter(tp, &n->res);
611 u32_remove_hw_knode(tp, n, extack);
612 idr_remove(&ht->handle_idr, n->handle);
613 if (tcf_exts_get_net(&n->exts))
614 call_rcu(&n->rcu, u32_delete_key_freepf_rcu);
615 else
616 u32_destroy_key(n->tp, n, true);
617 }
618 }
619 }
620
621 static int u32_destroy_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht,
622 struct netlink_ext_ack *extack)
623 {
624 struct tc_u_common *tp_c = tp->data;
625 struct tc_u_hnode __rcu **hn;
626 struct tc_u_hnode *phn;
627
628 WARN_ON(ht->refcnt);
629
630 u32_clear_hnode(tp, ht, extack);
631
632 hn = &tp_c->hlist;
633 for (phn = rtnl_dereference(*hn);
634 phn;
635 hn = &phn->next, phn = rtnl_dereference(*hn)) {
636 if (phn == ht) {
637 u32_clear_hw_hnode(tp, ht, extack);
638 idr_destroy(&ht->handle_idr);
639 idr_remove(&tp_c->handle_idr, ht->handle);
640 RCU_INIT_POINTER(*hn, ht->next);
641 kfree_rcu(ht, rcu);
642 return 0;
643 }
644 }
645
646 return -ENOENT;
647 }
648
649 static bool ht_empty(struct tc_u_hnode *ht)
650 {
651 unsigned int h;
652
653 for (h = 0; h <= ht->divisor; h++)
654 if (rcu_access_pointer(ht->ht[h]))
655 return false;
656
657 return true;
658 }
659
660 static void u32_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
661 {
662 struct tc_u_common *tp_c = tp->data;
663 struct tc_u_hnode *root_ht = rtnl_dereference(tp->root);
664
665 WARN_ON(root_ht == NULL);
666
667 if (root_ht && --root_ht->refcnt == 0)
668 u32_destroy_hnode(tp, root_ht, extack);
669
670 if (--tp_c->refcnt == 0) {
671 struct tc_u_hnode *ht;
672
673 hlist_del(&tp_c->hnode);
674
675 while ((ht = rtnl_dereference(tp_c->hlist)) != NULL) {
676 u32_clear_hnode(tp, ht, extack);
677 RCU_INIT_POINTER(tp_c->hlist, ht->next);
678
679 /* u32_destroy_key() will later free ht for us, if it's
680 * still referenced by some knode
681 */
682 if (--ht->refcnt == 0)
683 kfree_rcu(ht, rcu);
684 }
685
686 idr_destroy(&tp_c->handle_idr);
687 kfree(tp_c);
688 }
689
690 tp->data = NULL;
691 }
692
693 static int u32_delete(struct tcf_proto *tp, void *arg, bool *last,
694 struct netlink_ext_ack *extack)
695 {
696 struct tc_u_hnode *ht = arg;
697 struct tc_u_hnode *root_ht = rtnl_dereference(tp->root);
698 struct tc_u_common *tp_c = tp->data;
699 int ret = 0;
700
701 if (ht == NULL)
702 goto out;
703
704 if (TC_U32_KEY(ht->handle)) {
705 u32_remove_hw_knode(tp, (struct tc_u_knode *)ht, extack);
706 ret = u32_delete_key(tp, (struct tc_u_knode *)ht);
707 goto out;
708 }
709
710 if (root_ht == ht) {
711 NL_SET_ERR_MSG_MOD(extack, "Not allowed to delete root node");
712 return -EINVAL;
713 }
714
715 if (ht->refcnt == 1) {
716 ht->refcnt--;
717 u32_destroy_hnode(tp, ht, extack);
718 } else {
719 NL_SET_ERR_MSG_MOD(extack, "Can not delete in-use filter");
720 return -EBUSY;
721 }
722
723 out:
724 *last = true;
725 if (root_ht) {
726 if (root_ht->refcnt > 1) {
727 *last = false;
728 goto ret;
729 }
730 if (root_ht->refcnt == 1) {
731 if (!ht_empty(root_ht)) {
732 *last = false;
733 goto ret;
734 }
735 }
736 }
737
738 if (tp_c->refcnt > 1) {
739 *last = false;
740 goto ret;
741 }
742
743 if (tp_c->refcnt == 1) {
744 struct tc_u_hnode *ht;
745
746 for (ht = rtnl_dereference(tp_c->hlist);
747 ht;
748 ht = rtnl_dereference(ht->next))
749 if (!ht_empty(ht)) {
750 *last = false;
751 break;
752 }
753 }
754
755 ret:
756 return ret;
757 }
758
759 static u32 gen_new_kid(struct tc_u_hnode *ht, u32 htid)
760 {
761 u32 index = htid | 0x800;
762 u32 max = htid | 0xFFF;
763
764 if (idr_alloc_u32(&ht->handle_idr, NULL, &index, max, GFP_KERNEL)) {
765 index = htid + 1;
766 if (idr_alloc_u32(&ht->handle_idr, NULL, &index, max,
767 GFP_KERNEL))
768 index = max;
769 }
770
771 return index;
772 }
773
774 static const struct nla_policy u32_policy[TCA_U32_MAX + 1] = {
775 [TCA_U32_CLASSID] = { .type = NLA_U32 },
776 [TCA_U32_HASH] = { .type = NLA_U32 },
777 [TCA_U32_LINK] = { .type = NLA_U32 },
778 [TCA_U32_DIVISOR] = { .type = NLA_U32 },
779 [TCA_U32_SEL] = { .len = sizeof(struct tc_u32_sel) },
780 [TCA_U32_INDEV] = { .type = NLA_STRING, .len = IFNAMSIZ },
781 [TCA_U32_MARK] = { .len = sizeof(struct tc_u32_mark) },
782 [TCA_U32_FLAGS] = { .type = NLA_U32 },
783 };
784
785 static int u32_set_parms(struct net *net, struct tcf_proto *tp,
786 unsigned long base, struct tc_u_hnode *ht,
787 struct tc_u_knode *n, struct nlattr **tb,
788 struct nlattr *est, bool ovr,
789 struct netlink_ext_ack *extack)
790 {
791 int err;
792
793 err = tcf_exts_validate(net, tp, tb, est, &n->exts, ovr, extack);
794 if (err < 0)
795 return err;
796
797 if (tb[TCA_U32_LINK]) {
798 u32 handle = nla_get_u32(tb[TCA_U32_LINK]);
799 struct tc_u_hnode *ht_down = NULL, *ht_old;
800
801 if (TC_U32_KEY(handle)) {
802 NL_SET_ERR_MSG_MOD(extack, "u32 Link handle must be a hash table");
803 return -EINVAL;
804 }
805
806 if (handle) {
807 ht_down = u32_lookup_ht(ht->tp_c, handle);
808
809 if (!ht_down) {
810 NL_SET_ERR_MSG_MOD(extack, "Link hash table not found");
811 return -EINVAL;
812 }
813 ht_down->refcnt++;
814 }
815
816 ht_old = rtnl_dereference(n->ht_down);
817 rcu_assign_pointer(n->ht_down, ht_down);
818
819 if (ht_old)
820 ht_old->refcnt--;
821 }
822 if (tb[TCA_U32_CLASSID]) {
823 n->res.classid = nla_get_u32(tb[TCA_U32_CLASSID]);
824 tcf_bind_filter(tp, &n->res, base);
825 }
826
827 #ifdef CONFIG_NET_CLS_IND
828 if (tb[TCA_U32_INDEV]) {
829 int ret;
830 ret = tcf_change_indev(net, tb[TCA_U32_INDEV], extack);
831 if (ret < 0)
832 return -EINVAL;
833 n->ifindex = ret;
834 }
835 #endif
836 return 0;
837 }
838
839 static void u32_replace_knode(struct tcf_proto *tp, struct tc_u_common *tp_c,
840 struct tc_u_knode *n)
841 {
842 struct tc_u_knode __rcu **ins;
843 struct tc_u_knode *pins;
844 struct tc_u_hnode *ht;
845
846 if (TC_U32_HTID(n->handle) == TC_U32_ROOT)
847 ht = rtnl_dereference(tp->root);
848 else
849 ht = u32_lookup_ht(tp_c, TC_U32_HTID(n->handle));
850
851 ins = &ht->ht[TC_U32_HASH(n->handle)];
852
853 /* The node must always exist for it to be replaced if this is not the
854 * case then something went very wrong elsewhere.
855 */
856 for (pins = rtnl_dereference(*ins); ;
857 ins = &pins->next, pins = rtnl_dereference(*ins))
858 if (pins->handle == n->handle)
859 break;
860
861 idr_replace(&ht->handle_idr, n, n->handle);
862 RCU_INIT_POINTER(n->next, pins->next);
863 rcu_assign_pointer(*ins, n);
864 }
865
866 static struct tc_u_knode *u32_init_knode(struct tcf_proto *tp,
867 struct tc_u_knode *n)
868 {
869 struct tc_u_hnode *ht = rtnl_dereference(n->ht_down);
870 struct tc_u32_sel *s = &n->sel;
871 struct tc_u_knode *new;
872
873 new = kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key),
874 GFP_KERNEL);
875
876 if (!new)
877 return NULL;
878
879 RCU_INIT_POINTER(new->next, n->next);
880 new->handle = n->handle;
881 RCU_INIT_POINTER(new->ht_up, n->ht_up);
882
883 #ifdef CONFIG_NET_CLS_IND
884 new->ifindex = n->ifindex;
885 #endif
886 new->fshift = n->fshift;
887 new->res = n->res;
888 new->flags = n->flags;
889 RCU_INIT_POINTER(new->ht_down, ht);
890
891 /* bump reference count as long as we hold pointer to structure */
892 if (ht)
893 ht->refcnt++;
894
895 #ifdef CONFIG_CLS_U32_PERF
896 /* Statistics may be incremented by readers during update
897 * so we must keep them in tact. When the node is later destroyed
898 * a special destroy call must be made to not free the pf memory.
899 */
900 new->pf = n->pf;
901 #endif
902
903 #ifdef CONFIG_CLS_U32_MARK
904 new->val = n->val;
905 new->mask = n->mask;
906 /* Similarly success statistics must be moved as pointers */
907 new->pcpu_success = n->pcpu_success;
908 #endif
909 new->tp = tp;
910 memcpy(&new->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
911
912 if (tcf_exts_init(&new->exts, TCA_U32_ACT, TCA_U32_POLICE)) {
913 kfree(new);
914 return NULL;
915 }
916
917 return new;
918 }
919
920 static int u32_change(struct net *net, struct sk_buff *in_skb,
921 struct tcf_proto *tp, unsigned long base, u32 handle,
922 struct nlattr **tca, void **arg, bool ovr,
923 struct netlink_ext_ack *extack)
924 {
925 struct tc_u_common *tp_c = tp->data;
926 struct tc_u_hnode *ht;
927 struct tc_u_knode *n;
928 struct tc_u32_sel *s;
929 struct nlattr *opt = tca[TCA_OPTIONS];
930 struct nlattr *tb[TCA_U32_MAX + 1];
931 u32 htid, flags = 0;
932 int err;
933 #ifdef CONFIG_CLS_U32_PERF
934 size_t size;
935 #endif
936
937 if (!opt) {
938 if (handle) {
939 NL_SET_ERR_MSG_MOD(extack, "Filter handle requires options");
940 return -EINVAL;
941 } else {
942 return 0;
943 }
944 }
945
946 err = nla_parse_nested(tb, TCA_U32_MAX, opt, u32_policy, extack);
947 if (err < 0)
948 return err;
949
950 if (tb[TCA_U32_FLAGS]) {
951 flags = nla_get_u32(tb[TCA_U32_FLAGS]);
952 if (!tc_flags_valid(flags)) {
953 NL_SET_ERR_MSG_MOD(extack, "Invalid filter flags");
954 return -EINVAL;
955 }
956 }
957
958 n = *arg;
959 if (n) {
960 struct tc_u_knode *new;
961
962 if (TC_U32_KEY(n->handle) == 0) {
963 NL_SET_ERR_MSG_MOD(extack, "Key node id cannot be zero");
964 return -EINVAL;
965 }
966
967 if ((n->flags ^ flags) &
968 ~(TCA_CLS_FLAGS_IN_HW | TCA_CLS_FLAGS_NOT_IN_HW)) {
969 NL_SET_ERR_MSG_MOD(extack, "Key node flags do not match passed flags");
970 return -EINVAL;
971 }
972
973 new = u32_init_knode(tp, n);
974 if (!new)
975 return -ENOMEM;
976
977 err = u32_set_parms(net, tp, base,
978 rtnl_dereference(n->ht_up), new, tb,
979 tca[TCA_RATE], ovr, extack);
980
981 if (err) {
982 u32_destroy_key(tp, new, false);
983 return err;
984 }
985
986 err = u32_replace_hw_knode(tp, new, flags, extack);
987 if (err) {
988 u32_destroy_key(tp, new, false);
989 return err;
990 }
991
992 if (!tc_in_hw(new->flags))
993 new->flags |= TCA_CLS_FLAGS_NOT_IN_HW;
994
995 u32_replace_knode(tp, tp_c, new);
996 tcf_unbind_filter(tp, &n->res);
997 tcf_exts_get_net(&n->exts);
998 call_rcu(&n->rcu, u32_delete_key_rcu);
999 return 0;
1000 }
1001
1002 if (tb[TCA_U32_DIVISOR]) {
1003 unsigned int divisor = nla_get_u32(tb[TCA_U32_DIVISOR]);
1004
1005 if (--divisor > 0x100) {
1006 NL_SET_ERR_MSG_MOD(extack, "Exceeded maximum 256 hash buckets");
1007 return -EINVAL;
1008 }
1009 if (TC_U32_KEY(handle)) {
1010 NL_SET_ERR_MSG_MOD(extack, "Divisor can only be used on a hash table");
1011 return -EINVAL;
1012 }
1013 ht = kzalloc(sizeof(*ht) + divisor*sizeof(void *), GFP_KERNEL);
1014 if (ht == NULL)
1015 return -ENOBUFS;
1016 if (handle == 0) {
1017 handle = gen_new_htid(tp->data, ht);
1018 if (handle == 0) {
1019 kfree(ht);
1020 return -ENOMEM;
1021 }
1022 } else {
1023 err = idr_alloc_u32(&tp_c->handle_idr, ht, &handle,
1024 handle, GFP_KERNEL);
1025 if (err) {
1026 kfree(ht);
1027 return err;
1028 }
1029 }
1030 ht->tp_c = tp_c;
1031 ht->refcnt = 1;
1032 ht->divisor = divisor;
1033 ht->handle = handle;
1034 ht->prio = tp->prio;
1035 idr_init(&ht->handle_idr);
1036 ht->flags = flags;
1037
1038 err = u32_replace_hw_hnode(tp, ht, flags, extack);
1039 if (err) {
1040 idr_remove(&tp_c->handle_idr, handle);
1041 kfree(ht);
1042 return err;
1043 }
1044
1045 RCU_INIT_POINTER(ht->next, tp_c->hlist);
1046 rcu_assign_pointer(tp_c->hlist, ht);
1047 *arg = ht;
1048
1049 return 0;
1050 }
1051
1052 if (tb[TCA_U32_HASH]) {
1053 htid = nla_get_u32(tb[TCA_U32_HASH]);
1054 if (TC_U32_HTID(htid) == TC_U32_ROOT) {
1055 ht = rtnl_dereference(tp->root);
1056 htid = ht->handle;
1057 } else {
1058 ht = u32_lookup_ht(tp->data, TC_U32_HTID(htid));
1059 if (!ht) {
1060 NL_SET_ERR_MSG_MOD(extack, "Specified hash table not found");
1061 return -EINVAL;
1062 }
1063 }
1064 } else {
1065 ht = rtnl_dereference(tp->root);
1066 htid = ht->handle;
1067 }
1068
1069 if (ht->divisor < TC_U32_HASH(htid)) {
1070 NL_SET_ERR_MSG_MOD(extack, "Specified hash table buckets exceed configured value");
1071 return -EINVAL;
1072 }
1073
1074 if (handle) {
1075 if (TC_U32_HTID(handle) && TC_U32_HTID(handle ^ htid)) {
1076 NL_SET_ERR_MSG_MOD(extack, "Handle specified hash table address mismatch");
1077 return -EINVAL;
1078 }
1079 handle = htid | TC_U32_NODE(handle);
1080 err = idr_alloc_u32(&ht->handle_idr, NULL, &handle, handle,
1081 GFP_KERNEL);
1082 if (err)
1083 return err;
1084 } else
1085 handle = gen_new_kid(ht, htid);
1086
1087 if (tb[TCA_U32_SEL] == NULL) {
1088 NL_SET_ERR_MSG_MOD(extack, "Selector not specified");
1089 err = -EINVAL;
1090 goto erridr;
1091 }
1092
1093 s = nla_data(tb[TCA_U32_SEL]);
1094
1095 n = kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key), GFP_KERNEL);
1096 if (n == NULL) {
1097 err = -ENOBUFS;
1098 goto erridr;
1099 }
1100
1101 #ifdef CONFIG_CLS_U32_PERF
1102 size = sizeof(struct tc_u32_pcnt) + s->nkeys * sizeof(u64);
1103 n->pf = __alloc_percpu(size, __alignof__(struct tc_u32_pcnt));
1104 if (!n->pf) {
1105 err = -ENOBUFS;
1106 goto errfree;
1107 }
1108 #endif
1109
1110 memcpy(&n->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
1111 RCU_INIT_POINTER(n->ht_up, ht);
1112 n->handle = handle;
1113 n->fshift = s->hmask ? ffs(ntohl(s->hmask)) - 1 : 0;
1114 n->flags = flags;
1115 n->tp = tp;
1116
1117 err = tcf_exts_init(&n->exts, TCA_U32_ACT, TCA_U32_POLICE);
1118 if (err < 0)
1119 goto errout;
1120
1121 #ifdef CONFIG_CLS_U32_MARK
1122 n->pcpu_success = alloc_percpu(u32);
1123 if (!n->pcpu_success) {
1124 err = -ENOMEM;
1125 goto errout;
1126 }
1127
1128 if (tb[TCA_U32_MARK]) {
1129 struct tc_u32_mark *mark;
1130
1131 mark = nla_data(tb[TCA_U32_MARK]);
1132 n->val = mark->val;
1133 n->mask = mark->mask;
1134 }
1135 #endif
1136
1137 err = u32_set_parms(net, tp, base, ht, n, tb, tca[TCA_RATE], ovr,
1138 extack);
1139 if (err == 0) {
1140 struct tc_u_knode __rcu **ins;
1141 struct tc_u_knode *pins;
1142
1143 err = u32_replace_hw_knode(tp, n, flags, extack);
1144 if (err)
1145 goto errhw;
1146
1147 if (!tc_in_hw(n->flags))
1148 n->flags |= TCA_CLS_FLAGS_NOT_IN_HW;
1149
1150 ins = &ht->ht[TC_U32_HASH(handle)];
1151 for (pins = rtnl_dereference(*ins); pins;
1152 ins = &pins->next, pins = rtnl_dereference(*ins))
1153 if (TC_U32_NODE(handle) < TC_U32_NODE(pins->handle))
1154 break;
1155
1156 RCU_INIT_POINTER(n->next, pins);
1157 rcu_assign_pointer(*ins, n);
1158 *arg = n;
1159 return 0;
1160 }
1161
1162 errhw:
1163 #ifdef CONFIG_CLS_U32_MARK
1164 free_percpu(n->pcpu_success);
1165 #endif
1166
1167 errout:
1168 tcf_exts_destroy(&n->exts);
1169 #ifdef CONFIG_CLS_U32_PERF
1170 errfree:
1171 free_percpu(n->pf);
1172 #endif
1173 kfree(n);
1174 erridr:
1175 idr_remove(&ht->handle_idr, handle);
1176 return err;
1177 }
1178
1179 static void u32_walk(struct tcf_proto *tp, struct tcf_walker *arg)
1180 {
1181 struct tc_u_common *tp_c = tp->data;
1182 struct tc_u_hnode *ht;
1183 struct tc_u_knode *n;
1184 unsigned int h;
1185
1186 if (arg->stop)
1187 return;
1188
1189 for (ht = rtnl_dereference(tp_c->hlist);
1190 ht;
1191 ht = rtnl_dereference(ht->next)) {
1192 if (ht->prio != tp->prio)
1193 continue;
1194 if (arg->count >= arg->skip) {
1195 if (arg->fn(tp, ht, arg) < 0) {
1196 arg->stop = 1;
1197 return;
1198 }
1199 }
1200 arg->count++;
1201 for (h = 0; h <= ht->divisor; h++) {
1202 for (n = rtnl_dereference(ht->ht[h]);
1203 n;
1204 n = rtnl_dereference(n->next)) {
1205 if (arg->count < arg->skip) {
1206 arg->count++;
1207 continue;
1208 }
1209 if (arg->fn(tp, n, arg) < 0) {
1210 arg->stop = 1;
1211 return;
1212 }
1213 arg->count++;
1214 }
1215 }
1216 }
1217 }
1218
1219 static void u32_bind_class(void *fh, u32 classid, unsigned long cl)
1220 {
1221 struct tc_u_knode *n = fh;
1222
1223 if (n && n->res.classid == classid)
1224 n->res.class = cl;
1225 }
1226
1227 static int u32_dump(struct net *net, struct tcf_proto *tp, void *fh,
1228 struct sk_buff *skb, struct tcmsg *t)
1229 {
1230 struct tc_u_knode *n = fh;
1231 struct tc_u_hnode *ht_up, *ht_down;
1232 struct nlattr *nest;
1233
1234 if (n == NULL)
1235 return skb->len;
1236
1237 t->tcm_handle = n->handle;
1238
1239 nest = nla_nest_start(skb, TCA_OPTIONS);
1240 if (nest == NULL)
1241 goto nla_put_failure;
1242
1243 if (TC_U32_KEY(n->handle) == 0) {
1244 struct tc_u_hnode *ht = fh;
1245 u32 divisor = ht->divisor + 1;
1246
1247 if (nla_put_u32(skb, TCA_U32_DIVISOR, divisor))
1248 goto nla_put_failure;
1249 } else {
1250 #ifdef CONFIG_CLS_U32_PERF
1251 struct tc_u32_pcnt *gpf;
1252 int cpu;
1253 #endif
1254
1255 if (nla_put(skb, TCA_U32_SEL,
1256 sizeof(n->sel) + n->sel.nkeys*sizeof(struct tc_u32_key),
1257 &n->sel))
1258 goto nla_put_failure;
1259
1260 ht_up = rtnl_dereference(n->ht_up);
1261 if (ht_up) {
1262 u32 htid = n->handle & 0xFFFFF000;
1263 if (nla_put_u32(skb, TCA_U32_HASH, htid))
1264 goto nla_put_failure;
1265 }
1266 if (n->res.classid &&
1267 nla_put_u32(skb, TCA_U32_CLASSID, n->res.classid))
1268 goto nla_put_failure;
1269
1270 ht_down = rtnl_dereference(n->ht_down);
1271 if (ht_down &&
1272 nla_put_u32(skb, TCA_U32_LINK, ht_down->handle))
1273 goto nla_put_failure;
1274
1275 if (n->flags && nla_put_u32(skb, TCA_U32_FLAGS, n->flags))
1276 goto nla_put_failure;
1277
1278 #ifdef CONFIG_CLS_U32_MARK
1279 if ((n->val || n->mask)) {
1280 struct tc_u32_mark mark = {.val = n->val,
1281 .mask = n->mask,
1282 .success = 0};
1283 int cpum;
1284
1285 for_each_possible_cpu(cpum) {
1286 __u32 cnt = *per_cpu_ptr(n->pcpu_success, cpum);
1287
1288 mark.success += cnt;
1289 }
1290
1291 if (nla_put(skb, TCA_U32_MARK, sizeof(mark), &mark))
1292 goto nla_put_failure;
1293 }
1294 #endif
1295
1296 if (tcf_exts_dump(skb, &n->exts) < 0)
1297 goto nla_put_failure;
1298
1299 #ifdef CONFIG_NET_CLS_IND
1300 if (n->ifindex) {
1301 struct net_device *dev;
1302 dev = __dev_get_by_index(net, n->ifindex);
1303 if (dev && nla_put_string(skb, TCA_U32_INDEV, dev->name))
1304 goto nla_put_failure;
1305 }
1306 #endif
1307 #ifdef CONFIG_CLS_U32_PERF
1308 gpf = kzalloc(sizeof(struct tc_u32_pcnt) +
1309 n->sel.nkeys * sizeof(u64),
1310 GFP_KERNEL);
1311 if (!gpf)
1312 goto nla_put_failure;
1313
1314 for_each_possible_cpu(cpu) {
1315 int i;
1316 struct tc_u32_pcnt *pf = per_cpu_ptr(n->pf, cpu);
1317
1318 gpf->rcnt += pf->rcnt;
1319 gpf->rhit += pf->rhit;
1320 for (i = 0; i < n->sel.nkeys; i++)
1321 gpf->kcnts[i] += pf->kcnts[i];
1322 }
1323
1324 if (nla_put_64bit(skb, TCA_U32_PCNT,
1325 sizeof(struct tc_u32_pcnt) +
1326 n->sel.nkeys * sizeof(u64),
1327 gpf, TCA_U32_PAD)) {
1328 kfree(gpf);
1329 goto nla_put_failure;
1330 }
1331 kfree(gpf);
1332 #endif
1333 }
1334
1335 nla_nest_end(skb, nest);
1336
1337 if (TC_U32_KEY(n->handle))
1338 if (tcf_exts_dump_stats(skb, &n->exts) < 0)
1339 goto nla_put_failure;
1340 return skb->len;
1341
1342 nla_put_failure:
1343 nla_nest_cancel(skb, nest);
1344 return -1;
1345 }
1346
1347 static struct tcf_proto_ops cls_u32_ops __read_mostly = {
1348 .kind = "u32",
1349 .classify = u32_classify,
1350 .init = u32_init,
1351 .destroy = u32_destroy,
1352 .get = u32_get,
1353 .change = u32_change,
1354 .delete = u32_delete,
1355 .walk = u32_walk,
1356 .dump = u32_dump,
1357 .bind_class = u32_bind_class,
1358 .owner = THIS_MODULE,
1359 };
1360
1361 static int __init init_u32(void)
1362 {
1363 int i, ret;
1364
1365 pr_info("u32 classifier\n");
1366 #ifdef CONFIG_CLS_U32_PERF
1367 pr_info(" Performance counters on\n");
1368 #endif
1369 #ifdef CONFIG_NET_CLS_IND
1370 pr_info(" input device check on\n");
1371 #endif
1372 #ifdef CONFIG_NET_CLS_ACT
1373 pr_info(" Actions configured\n");
1374 #endif
1375 tc_u_common_hash = kvmalloc_array(U32_HASH_SIZE,
1376 sizeof(struct hlist_head),
1377 GFP_KERNEL);
1378 if (!tc_u_common_hash)
1379 return -ENOMEM;
1380
1381 for (i = 0; i < U32_HASH_SIZE; i++)
1382 INIT_HLIST_HEAD(&tc_u_common_hash[i]);
1383
1384 ret = register_tcf_proto_ops(&cls_u32_ops);
1385 if (ret)
1386 kvfree(tc_u_common_hash);
1387 return ret;
1388 }
1389
1390 static void __exit exit_u32(void)
1391 {
1392 unregister_tcf_proto_ops(&cls_u32_ops);
1393 kvfree(tc_u_common_hash);
1394 }
1395
1396 module_init(init_u32)
1397 module_exit(exit_u32)
1398 MODULE_LICENSE("GPL");
Linux with added FPC-III support