1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * net/sched/em_meta.c Metadata ematch
4 *
5 * Authors: Thomas Graf <tgraf@suug.ch>
6 *
7 * ==========================================================================
8 *
9 * The metadata ematch compares two meta objects where each object
10 * represents either a meta value stored in the kernel or a static
11 * value provided by userspace. The objects are not provided by
12 * userspace itself but rather a definition providing the information
13 * to build them. Every object is of a certain type which must be
14 * equal to the object it is being compared to.
15 *
16 * The definition of a objects conists of the type (meta type), a
17 * identifier (meta id) and additional type specific information.
18 * The meta id is either TCF_META_TYPE_VALUE for values provided by
19 * userspace or a index to the meta operations table consisting of
20 * function pointers to type specific meta data collectors returning
21 * the value of the requested meta value.
22 *
23 * lvalue rvalue
24 * +-----------+ +-----------+
25 * | type: INT | | type: INT |
26 * def | id: DEV | | id: VALUE |
27 * | data: | | data: 3 |
28 * +-----------+ +-----------+
29 * | |
30 * ---> meta_ops[INT][DEV](...) |
31 * | |
32 * ----------- |
33 * V V
34 * +-----------+ +-----------+
35 * | type: INT | | type: INT |
36 * obj | id: DEV | | id: VALUE |
37 * | data: 2 |<--data got filled out | data: 3 |
38 * +-----------+ +-----------+
39 * | |
40 * --------------> 2 equals 3 <--------------
41 *
42 * This is a simplified schema, the complexity varies depending
43 * on the meta type. Obviously, the length of the data must also
44 * be provided for non-numeric types.
45 *
46 * Additionally, type dependent modifiers such as shift operators
47 * or mask may be applied to extend the functionaliy. As of now,
48 * the variable length type supports shifting the byte string to
49 * the right, eating up any number of octets and thus supporting
50 * wildcard interface name comparisons such as "ppp%" matching
51 * ppp0..9.
52 *
53 * NOTE: Certain meta values depend on other subsystems and are
54 * only available if that subsystem is enabled in the kernel.
55 */
56
57 #include <linux/slab.h>
58 #include <linux/module.h>
59 #include <linux/types.h>
60 #include <linux/kernel.h>
61 #include <linux/sched.h>
62 #include <linux/sched/loadavg.h>
63 #include <linux/string.h>
64 #include <linux/skbuff.h>
65 #include <linux/random.h>
66 #include <linux/if_vlan.h>
67 #include <linux/tc_ematch/tc_em_meta.h>
68 #include <net/dst.h>
69 #include <net/route.h>
70 #include <net/pkt_cls.h>
71 #include <net/sock.h>
72
73 struct meta_obj {
74 unsigned long value;
75 unsigned int len;
76 };
77
78 struct meta_value {
79 struct tcf_meta_val hdr;
80 unsigned long val;
81 unsigned int len;
82 };
83
84 struct meta_match {
85 struct meta_value lvalue;
86 struct meta_value rvalue;
87 };
88
meta_id(struct meta_value * v)89 static inline int meta_id(struct meta_value *v)
90 {
91 return TCF_META_ID(v->hdr.kind);
92 }
93
meta_type(struct meta_value * v)94 static inline int meta_type(struct meta_value *v)
95 {
96 return TCF_META_TYPE(v->hdr.kind);
97 }
98
99 #define META_COLLECTOR(FUNC) static void meta_##FUNC(struct sk_buff *skb, \
100 struct tcf_pkt_info *info, struct meta_value *v, \
101 struct meta_obj *dst, int *err)
102
103 /**************************************************************************
104 * System status & misc
105 **************************************************************************/
106
META_COLLECTOR(int_random)107 META_COLLECTOR(int_random)
108 {
109 get_random_bytes(&dst->value, sizeof(dst->value));
110 }
111
fixed_loadavg(int load)112 static inline unsigned long fixed_loadavg(int load)
113 {
114 int rnd_load = load + (FIXED_1/200);
115 int rnd_frac = ((rnd_load & (FIXED_1-1)) * 100) >> FSHIFT;
116
117 return ((rnd_load >> FSHIFT) * 100) + rnd_frac;
118 }
119
META_COLLECTOR(int_loadavg_0)120 META_COLLECTOR(int_loadavg_0)
121 {
122 dst->value = fixed_loadavg(avenrun[0]);
123 }
124
META_COLLECTOR(int_loadavg_1)125 META_COLLECTOR(int_loadavg_1)
126 {
127 dst->value = fixed_loadavg(avenrun[1]);
128 }
129
META_COLLECTOR(int_loadavg_2)130 META_COLLECTOR(int_loadavg_2)
131 {
132 dst->value = fixed_loadavg(avenrun[2]);
133 }
134
135 /**************************************************************************
136 * Device names & indices
137 **************************************************************************/
138
int_dev(struct net_device * dev,struct meta_obj * dst)139 static inline int int_dev(struct net_device *dev, struct meta_obj *dst)
140 {
141 if (unlikely(dev == NULL))
142 return -1;
143
144 dst->value = dev->ifindex;
145 return 0;
146 }
147
var_dev(struct net_device * dev,struct meta_obj * dst)148 static inline int var_dev(struct net_device *dev, struct meta_obj *dst)
149 {
150 if (unlikely(dev == NULL))
151 return -1;
152
153 dst->value = (unsigned long) dev->name;
154 dst->len = strlen(dev->name);
155 return 0;
156 }
157
META_COLLECTOR(int_dev)158 META_COLLECTOR(int_dev)
159 {
160 *err = int_dev(skb->dev, dst);
161 }
162
META_COLLECTOR(var_dev)163 META_COLLECTOR(var_dev)
164 {
165 *err = var_dev(skb->dev, dst);
166 }
167
168 /**************************************************************************
169 * vlan tag
170 **************************************************************************/
171
META_COLLECTOR(int_vlan_tag)172 META_COLLECTOR(int_vlan_tag)
173 {
174 unsigned short tag;
175
176 if (skb_vlan_tag_present(skb))
177 dst->value = skb_vlan_tag_get(skb);
178 else if (!__vlan_get_tag(skb, &tag))
179 dst->value = tag;
180 else
181 *err = -1;
182 }
183
184
185
186 /**************************************************************************
187 * skb attributes
188 **************************************************************************/
189
META_COLLECTOR(int_priority)190 META_COLLECTOR(int_priority)
191 {
192 dst->value = skb->priority;
193 }
194
META_COLLECTOR(int_protocol)195 META_COLLECTOR(int_protocol)
196 {
197 /* Let userspace take care of the byte ordering */
198 dst->value = skb_protocol(skb, false);
199 }
200
META_COLLECTOR(int_pkttype)201 META_COLLECTOR(int_pkttype)
202 {
203 dst->value = skb->pkt_type;
204 }
205
META_COLLECTOR(int_pktlen)206 META_COLLECTOR(int_pktlen)
207 {
208 dst->value = skb->len;
209 }
210
META_COLLECTOR(int_datalen)211 META_COLLECTOR(int_datalen)
212 {
213 dst->value = skb->data_len;
214 }
215
META_COLLECTOR(int_maclen)216 META_COLLECTOR(int_maclen)
217 {
218 dst->value = skb->mac_len;
219 }
220
META_COLLECTOR(int_rxhash)221 META_COLLECTOR(int_rxhash)
222 {
223 dst->value = skb_get_hash(skb);
224 }
225
226 /**************************************************************************
227 * Netfilter
228 **************************************************************************/
229
META_COLLECTOR(int_mark)230 META_COLLECTOR(int_mark)
231 {
232 dst->value = skb->mark;
233 }
234
235 /**************************************************************************
236 * Traffic Control
237 **************************************************************************/
238
META_COLLECTOR(int_tcindex)239 META_COLLECTOR(int_tcindex)
240 {
241 dst->value = skb->tc_index;
242 }
243
244 /**************************************************************************
245 * Routing
246 **************************************************************************/
247
META_COLLECTOR(int_rtclassid)248 META_COLLECTOR(int_rtclassid)
249 {
250 if (unlikely(skb_dst(skb) == NULL))
251 *err = -1;
252 else
253 #ifdef CONFIG_IP_ROUTE_CLASSID
254 dst->value = skb_dst(skb)->tclassid;
255 #else
256 dst->value = 0;
257 #endif
258 }
259
META_COLLECTOR(int_rtiif)260 META_COLLECTOR(int_rtiif)
261 {
262 if (unlikely(skb_rtable(skb) == NULL))
263 *err = -1;
264 else
265 dst->value = inet_iif(skb);
266 }
267
268 /**************************************************************************
269 * Socket Attributes
270 **************************************************************************/
271
272 #define skip_nonlocal(skb) \
273 (unlikely(skb->sk == NULL))
274
META_COLLECTOR(int_sk_family)275 META_COLLECTOR(int_sk_family)
276 {
277 if (skip_nonlocal(skb)) {
278 *err = -1;
279 return;
280 }
281 dst->value = skb->sk->sk_family;
282 }
283
META_COLLECTOR(int_sk_state)284 META_COLLECTOR(int_sk_state)
285 {
286 if (skip_nonlocal(skb)) {
287 *err = -1;
288 return;
289 }
290 dst->value = skb->sk->sk_state;
291 }
292
META_COLLECTOR(int_sk_reuse)293 META_COLLECTOR(int_sk_reuse)
294 {
295 if (skip_nonlocal(skb)) {
296 *err = -1;
297 return;
298 }
299 dst->value = skb->sk->sk_reuse;
300 }
301
META_COLLECTOR(int_sk_bound_if)302 META_COLLECTOR(int_sk_bound_if)
303 {
304 if (skip_nonlocal(skb)) {
305 *err = -1;
306 return;
307 }
308 /* No error if bound_dev_if is 0, legal userspace check */
309 dst->value = skb->sk->sk_bound_dev_if;
310 }
311
META_COLLECTOR(var_sk_bound_if)312 META_COLLECTOR(var_sk_bound_if)
313 {
314 if (skip_nonlocal(skb)) {
315 *err = -1;
316 return;
317 }
318
319 if (skb->sk->sk_bound_dev_if == 0) {
320 dst->value = (unsigned long) "any";
321 dst->len = 3;
322 } else {
323 struct net_device *dev;
324
325 rcu_read_lock();
326 dev = dev_get_by_index_rcu(sock_net(skb->sk),
327 skb->sk->sk_bound_dev_if);
328 *err = var_dev(dev, dst);
329 rcu_read_unlock();
330 }
331 }
332
META_COLLECTOR(int_sk_refcnt)333 META_COLLECTOR(int_sk_refcnt)
334 {
335 if (skip_nonlocal(skb)) {
336 *err = -1;
337 return;
338 }
339 dst->value = refcount_read(&skb->sk->sk_refcnt);
340 }
341
META_COLLECTOR(int_sk_rcvbuf)342 META_COLLECTOR(int_sk_rcvbuf)
343 {
344 const struct sock *sk = skb_to_full_sk(skb);
345
346 if (!sk) {
347 *err = -1;
348 return;
349 }
350 dst->value = sk->sk_rcvbuf;
351 }
352
META_COLLECTOR(int_sk_shutdown)353 META_COLLECTOR(int_sk_shutdown)
354 {
355 const struct sock *sk = skb_to_full_sk(skb);
356
357 if (!sk) {
358 *err = -1;
359 return;
360 }
361 dst->value = sk->sk_shutdown;
362 }
363
META_COLLECTOR(int_sk_proto)364 META_COLLECTOR(int_sk_proto)
365 {
366 const struct sock *sk = skb_to_full_sk(skb);
367
368 if (!sk) {
369 *err = -1;
370 return;
371 }
372 dst->value = sk->sk_protocol;
373 }
374
META_COLLECTOR(int_sk_type)375 META_COLLECTOR(int_sk_type)
376 {
377 const struct sock *sk = skb_to_full_sk(skb);
378
379 if (!sk) {
380 *err = -1;
381 return;
382 }
383 dst->value = sk->sk_type;
384 }
385
META_COLLECTOR(int_sk_rmem_alloc)386 META_COLLECTOR(int_sk_rmem_alloc)
387 {
388 const struct sock *sk = skb_to_full_sk(skb);
389
390 if (!sk) {
391 *err = -1;
392 return;
393 }
394 dst->value = sk_rmem_alloc_get(sk);
395 }
396
META_COLLECTOR(int_sk_wmem_alloc)397 META_COLLECTOR(int_sk_wmem_alloc)
398 {
399 const struct sock *sk = skb_to_full_sk(skb);
400
401 if (!sk) {
402 *err = -1;
403 return;
404 }
405 dst->value = sk_wmem_alloc_get(sk);
406 }
407
META_COLLECTOR(int_sk_omem_alloc)408 META_COLLECTOR(int_sk_omem_alloc)
409 {
410 const struct sock *sk = skb_to_full_sk(skb);
411
412 if (!sk) {
413 *err = -1;
414 return;
415 }
416 dst->value = atomic_read(&sk->sk_omem_alloc);
417 }
418
META_COLLECTOR(int_sk_rcv_qlen)419 META_COLLECTOR(int_sk_rcv_qlen)
420 {
421 const struct sock *sk = skb_to_full_sk(skb);
422
423 if (!sk) {
424 *err = -1;
425 return;
426 }
427 dst->value = sk->sk_receive_queue.qlen;
428 }
429
META_COLLECTOR(int_sk_snd_qlen)430 META_COLLECTOR(int_sk_snd_qlen)
431 {
432 const struct sock *sk = skb_to_full_sk(skb);
433
434 if (!sk) {
435 *err = -1;
436 return;
437 }
438 dst->value = sk->sk_write_queue.qlen;
439 }
440
META_COLLECTOR(int_sk_wmem_queued)441 META_COLLECTOR(int_sk_wmem_queued)
442 {
443 const struct sock *sk = skb_to_full_sk(skb);
444
445 if (!sk) {
446 *err = -1;
447 return;
448 }
449 dst->value = READ_ONCE(sk->sk_wmem_queued);
450 }
451
META_COLLECTOR(int_sk_fwd_alloc)452 META_COLLECTOR(int_sk_fwd_alloc)
453 {
454 const struct sock *sk = skb_to_full_sk(skb);
455
456 if (!sk) {
457 *err = -1;
458 return;
459 }
460 dst->value = sk->sk_forward_alloc;
461 }
462
META_COLLECTOR(int_sk_sndbuf)463 META_COLLECTOR(int_sk_sndbuf)
464 {
465 const struct sock *sk = skb_to_full_sk(skb);
466
467 if (!sk) {
468 *err = -1;
469 return;
470 }
471 dst->value = sk->sk_sndbuf;
472 }
473
META_COLLECTOR(int_sk_alloc)474 META_COLLECTOR(int_sk_alloc)
475 {
476 const struct sock *sk = skb_to_full_sk(skb);
477
478 if (!sk) {
479 *err = -1;
480 return;
481 }
482 dst->value = (__force int) sk->sk_allocation;
483 }
484
META_COLLECTOR(int_sk_hash)485 META_COLLECTOR(int_sk_hash)
486 {
487 if (skip_nonlocal(skb)) {
488 *err = -1;
489 return;
490 }
491 dst->value = skb->sk->sk_hash;
492 }
493
META_COLLECTOR(int_sk_lingertime)494 META_COLLECTOR(int_sk_lingertime)
495 {
496 const struct sock *sk = skb_to_full_sk(skb);
497
498 if (!sk) {
499 *err = -1;
500 return;
501 }
502 dst->value = sk->sk_lingertime / HZ;
503 }
504
META_COLLECTOR(int_sk_err_qlen)505 META_COLLECTOR(int_sk_err_qlen)
506 {
507 const struct sock *sk = skb_to_full_sk(skb);
508
509 if (!sk) {
510 *err = -1;
511 return;
512 }
513 dst->value = sk->sk_error_queue.qlen;
514 }
515
META_COLLECTOR(int_sk_ack_bl)516 META_COLLECTOR(int_sk_ack_bl)
517 {
518 const struct sock *sk = skb_to_full_sk(skb);
519
520 if (!sk) {
521 *err = -1;
522 return;
523 }
524 dst->value = READ_ONCE(sk->sk_ack_backlog);
525 }
526
META_COLLECTOR(int_sk_max_ack_bl)527 META_COLLECTOR(int_sk_max_ack_bl)
528 {
529 const struct sock *sk = skb_to_full_sk(skb);
530
531 if (!sk) {
532 *err = -1;
533 return;
534 }
535 dst->value = READ_ONCE(sk->sk_max_ack_backlog);
536 }
537
META_COLLECTOR(int_sk_prio)538 META_COLLECTOR(int_sk_prio)
539 {
540 const struct sock *sk = skb_to_full_sk(skb);
541
542 if (!sk) {
543 *err = -1;
544 return;
545 }
546 dst->value = sk->sk_priority;
547 }
548
META_COLLECTOR(int_sk_rcvlowat)549 META_COLLECTOR(int_sk_rcvlowat)
550 {
551 const struct sock *sk = skb_to_full_sk(skb);
552
553 if (!sk) {
554 *err = -1;
555 return;
556 }
557 dst->value = READ_ONCE(sk->sk_rcvlowat);
558 }
559
META_COLLECTOR(int_sk_rcvtimeo)560 META_COLLECTOR(int_sk_rcvtimeo)
561 {
562 const struct sock *sk = skb_to_full_sk(skb);
563
564 if (!sk) {
565 *err = -1;
566 return;
567 }
568 dst->value = sk->sk_rcvtimeo / HZ;
569 }
570
META_COLLECTOR(int_sk_sndtimeo)571 META_COLLECTOR(int_sk_sndtimeo)
572 {
573 const struct sock *sk = skb_to_full_sk(skb);
574
575 if (!sk) {
576 *err = -1;
577 return;
578 }
579 dst->value = sk->sk_sndtimeo / HZ;
580 }
581
META_COLLECTOR(int_sk_sendmsg_off)582 META_COLLECTOR(int_sk_sendmsg_off)
583 {
584 const struct sock *sk = skb_to_full_sk(skb);
585
586 if (!sk) {
587 *err = -1;
588 return;
589 }
590 dst->value = sk->sk_frag.offset;
591 }
592
META_COLLECTOR(int_sk_write_pend)593 META_COLLECTOR(int_sk_write_pend)
594 {
595 const struct sock *sk = skb_to_full_sk(skb);
596
597 if (!sk) {
598 *err = -1;
599 return;
600 }
601 dst->value = sk->sk_write_pending;
602 }
603
604 /**************************************************************************
605 * Meta value collectors assignment table
606 **************************************************************************/
607
608 struct meta_ops {
609 void (*get)(struct sk_buff *, struct tcf_pkt_info *,
610 struct meta_value *, struct meta_obj *, int *);
611 };
612
613 #define META_ID(name) TCF_META_ID_##name
614 #define META_FUNC(name) { .get = meta_##name }
615
616 /* Meta value operations table listing all meta value collectors and
617 * assigns them to a type and meta id. */
618 static struct meta_ops __meta_ops[TCF_META_TYPE_MAX + 1][TCF_META_ID_MAX + 1] = {
619 [TCF_META_TYPE_VAR] = {
620 [META_ID(DEV)] = META_FUNC(var_dev),
621 [META_ID(SK_BOUND_IF)] = META_FUNC(var_sk_bound_if),
622 },
623 [TCF_META_TYPE_INT] = {
624 [META_ID(RANDOM)] = META_FUNC(int_random),
625 [META_ID(LOADAVG_0)] = META_FUNC(int_loadavg_0),
626 [META_ID(LOADAVG_1)] = META_FUNC(int_loadavg_1),
627 [META_ID(LOADAVG_2)] = META_FUNC(int_loadavg_2),
628 [META_ID(DEV)] = META_FUNC(int_dev),
629 [META_ID(PRIORITY)] = META_FUNC(int_priority),
630 [META_ID(PROTOCOL)] = META_FUNC(int_protocol),
631 [META_ID(PKTTYPE)] = META_FUNC(int_pkttype),
632 [META_ID(PKTLEN)] = META_FUNC(int_pktlen),
633 [META_ID(DATALEN)] = META_FUNC(int_datalen),
634 [META_ID(MACLEN)] = META_FUNC(int_maclen),
635 [META_ID(NFMARK)] = META_FUNC(int_mark),
636 [META_ID(TCINDEX)] = META_FUNC(int_tcindex),
637 [META_ID(RTCLASSID)] = META_FUNC(int_rtclassid),
638 [META_ID(RTIIF)] = META_FUNC(int_rtiif),
639 [META_ID(SK_FAMILY)] = META_FUNC(int_sk_family),
640 [META_ID(SK_STATE)] = META_FUNC(int_sk_state),
641 [META_ID(SK_REUSE)] = META_FUNC(int_sk_reuse),
642 [META_ID(SK_BOUND_IF)] = META_FUNC(int_sk_bound_if),
643 [META_ID(SK_REFCNT)] = META_FUNC(int_sk_refcnt),
644 [META_ID(SK_RCVBUF)] = META_FUNC(int_sk_rcvbuf),
645 [META_ID(SK_SNDBUF)] = META_FUNC(int_sk_sndbuf),
646 [META_ID(SK_SHUTDOWN)] = META_FUNC(int_sk_shutdown),
647 [META_ID(SK_PROTO)] = META_FUNC(int_sk_proto),
648 [META_ID(SK_TYPE)] = META_FUNC(int_sk_type),
649 [META_ID(SK_RMEM_ALLOC)] = META_FUNC(int_sk_rmem_alloc),
650 [META_ID(SK_WMEM_ALLOC)] = META_FUNC(int_sk_wmem_alloc),
651 [META_ID(SK_OMEM_ALLOC)] = META_FUNC(int_sk_omem_alloc),
652 [META_ID(SK_WMEM_QUEUED)] = META_FUNC(int_sk_wmem_queued),
653 [META_ID(SK_RCV_QLEN)] = META_FUNC(int_sk_rcv_qlen),
654 [META_ID(SK_SND_QLEN)] = META_FUNC(int_sk_snd_qlen),
655 [META_ID(SK_ERR_QLEN)] = META_FUNC(int_sk_err_qlen),
656 [META_ID(SK_FORWARD_ALLOCS)] = META_FUNC(int_sk_fwd_alloc),
657 [META_ID(SK_ALLOCS)] = META_FUNC(int_sk_alloc),
658 [META_ID(SK_HASH)] = META_FUNC(int_sk_hash),
659 [META_ID(SK_LINGERTIME)] = META_FUNC(int_sk_lingertime),
660 [META_ID(SK_ACK_BACKLOG)] = META_FUNC(int_sk_ack_bl),
661 [META_ID(SK_MAX_ACK_BACKLOG)] = META_FUNC(int_sk_max_ack_bl),
662 [META_ID(SK_PRIO)] = META_FUNC(int_sk_prio),
663 [META_ID(SK_RCVLOWAT)] = META_FUNC(int_sk_rcvlowat),
664 [META_ID(SK_RCVTIMEO)] = META_FUNC(int_sk_rcvtimeo),
665 [META_ID(SK_SNDTIMEO)] = META_FUNC(int_sk_sndtimeo),
666 [META_ID(SK_SENDMSG_OFF)] = META_FUNC(int_sk_sendmsg_off),
667 [META_ID(SK_WRITE_PENDING)] = META_FUNC(int_sk_write_pend),
668 [META_ID(VLAN_TAG)] = META_FUNC(int_vlan_tag),
669 [META_ID(RXHASH)] = META_FUNC(int_rxhash),
670 }
671 };
672
meta_ops(struct meta_value * val)673 static inline struct meta_ops *meta_ops(struct meta_value *val)
674 {
675 return &__meta_ops[meta_type(val)][meta_id(val)];
676 }
677
678 /**************************************************************************
679 * Type specific operations for TCF_META_TYPE_VAR
680 **************************************************************************/
681
meta_var_compare(struct meta_obj * a,struct meta_obj * b)682 static int meta_var_compare(struct meta_obj *a, struct meta_obj *b)
683 {
684 int r = a->len - b->len;
685
686 if (r == 0)
687 r = memcmp((void *) a->value, (void *) b->value, a->len);
688
689 return r;
690 }
691
meta_var_change(struct meta_value * dst,struct nlattr * nla)692 static int meta_var_change(struct meta_value *dst, struct nlattr *nla)
693 {
694 int len = nla_len(nla);
695
696 dst->val = (unsigned long)kmemdup(nla_data(nla), len, GFP_KERNEL);
697 if (dst->val == 0UL)
698 return -ENOMEM;
699 dst->len = len;
700 return 0;
701 }
702
meta_var_destroy(struct meta_value * v)703 static void meta_var_destroy(struct meta_value *v)
704 {
705 kfree((void *) v->val);
706 }
707
meta_var_apply_extras(struct meta_value * v,struct meta_obj * dst)708 static void meta_var_apply_extras(struct meta_value *v,
709 struct meta_obj *dst)
710 {
711 int shift = v->hdr.shift;
712
713 if (shift && shift < dst->len)
714 dst->len -= shift;
715 }
716
meta_var_dump(struct sk_buff * skb,struct meta_value * v,int tlv)717 static int meta_var_dump(struct sk_buff *skb, struct meta_value *v, int tlv)
718 {
719 if (v->val && v->len &&
720 nla_put(skb, tlv, v->len, (void *) v->val))
721 goto nla_put_failure;
722 return 0;
723
724 nla_put_failure:
725 return -1;
726 }
727
728 /**************************************************************************
729 * Type specific operations for TCF_META_TYPE_INT
730 **************************************************************************/
731
meta_int_compare(struct meta_obj * a,struct meta_obj * b)732 static int meta_int_compare(struct meta_obj *a, struct meta_obj *b)
733 {
734 /* Let gcc optimize it, the unlikely is not really based on
735 * some numbers but jump free code for mismatches seems
736 * more logical. */
737 if (unlikely(a->value == b->value))
738 return 0;
739 else if (a->value < b->value)
740 return -1;
741 else
742 return 1;
743 }
744
meta_int_change(struct meta_value * dst,struct nlattr * nla)745 static int meta_int_change(struct meta_value *dst, struct nlattr *nla)
746 {
747 if (nla_len(nla) >= sizeof(unsigned long)) {
748 dst->val = *(unsigned long *) nla_data(nla);
749 dst->len = sizeof(unsigned long);
750 } else if (nla_len(nla) == sizeof(u32)) {
751 dst->val = nla_get_u32(nla);
752 dst->len = sizeof(u32);
753 } else
754 return -EINVAL;
755
756 return 0;
757 }
758
meta_int_apply_extras(struct meta_value * v,struct meta_obj * dst)759 static void meta_int_apply_extras(struct meta_value *v,
760 struct meta_obj *dst)
761 {
762 if (v->hdr.shift)
763 dst->value >>= v->hdr.shift;
764
765 if (v->val)
766 dst->value &= v->val;
767 }
768
meta_int_dump(struct sk_buff * skb,struct meta_value * v,int tlv)769 static int meta_int_dump(struct sk_buff *skb, struct meta_value *v, int tlv)
770 {
771 if (v->len == sizeof(unsigned long)) {
772 if (nla_put(skb, tlv, sizeof(unsigned long), &v->val))
773 goto nla_put_failure;
774 } else if (v->len == sizeof(u32)) {
775 if (nla_put_u32(skb, tlv, v->val))
776 goto nla_put_failure;
777 }
778
779 return 0;
780
781 nla_put_failure:
782 return -1;
783 }
784
785 /**************************************************************************
786 * Type specific operations table
787 **************************************************************************/
788
789 struct meta_type_ops {
790 void (*destroy)(struct meta_value *);
791 int (*compare)(struct meta_obj *, struct meta_obj *);
792 int (*change)(struct meta_value *, struct nlattr *);
793 void (*apply_extras)(struct meta_value *, struct meta_obj *);
794 int (*dump)(struct sk_buff *, struct meta_value *, int);
795 };
796
797 static const struct meta_type_ops __meta_type_ops[TCF_META_TYPE_MAX + 1] = {
798 [TCF_META_TYPE_VAR] = {
799 .destroy = meta_var_destroy,
800 .compare = meta_var_compare,
801 .change = meta_var_change,
802 .apply_extras = meta_var_apply_extras,
803 .dump = meta_var_dump
804 },
805 [TCF_META_TYPE_INT] = {
806 .compare = meta_int_compare,
807 .change = meta_int_change,
808 .apply_extras = meta_int_apply_extras,
809 .dump = meta_int_dump
810 }
811 };
812
meta_type_ops(struct meta_value * v)813 static inline const struct meta_type_ops *meta_type_ops(struct meta_value *v)
814 {
815 return &__meta_type_ops[meta_type(v)];
816 }
817
818 /**************************************************************************
819 * Core
820 **************************************************************************/
821
meta_get(struct sk_buff * skb,struct tcf_pkt_info * info,struct meta_value * v,struct meta_obj * dst)822 static int meta_get(struct sk_buff *skb, struct tcf_pkt_info *info,
823 struct meta_value *v, struct meta_obj *dst)
824 {
825 int err = 0;
826
827 if (meta_id(v) == TCF_META_ID_VALUE) {
828 dst->value = v->val;
829 dst->len = v->len;
830 return 0;
831 }
832
833 meta_ops(v)->get(skb, info, v, dst, &err);
834 if (err < 0)
835 return err;
836
837 if (meta_type_ops(v)->apply_extras)
838 meta_type_ops(v)->apply_extras(v, dst);
839
840 return 0;
841 }
842
em_meta_match(struct sk_buff * skb,struct tcf_ematch * m,struct tcf_pkt_info * info)843 static int em_meta_match(struct sk_buff *skb, struct tcf_ematch *m,
844 struct tcf_pkt_info *info)
845 {
846 int r;
847 struct meta_match *meta = (struct meta_match *) m->data;
848 struct meta_obj l_value, r_value;
849
850 if (meta_get(skb, info, &meta->lvalue, &l_value) < 0 ||
851 meta_get(skb, info, &meta->rvalue, &r_value) < 0)
852 return 0;
853
854 r = meta_type_ops(&meta->lvalue)->compare(&l_value, &r_value);
855
856 switch (meta->lvalue.hdr.op) {
857 case TCF_EM_OPND_EQ:
858 return !r;
859 case TCF_EM_OPND_LT:
860 return r < 0;
861 case TCF_EM_OPND_GT:
862 return r > 0;
863 }
864
865 return 0;
866 }
867
meta_delete(struct meta_match * meta)868 static void meta_delete(struct meta_match *meta)
869 {
870 if (meta) {
871 const struct meta_type_ops *ops = meta_type_ops(&meta->lvalue);
872
873 if (ops && ops->destroy) {
874 ops->destroy(&meta->lvalue);
875 ops->destroy(&meta->rvalue);
876 }
877 }
878
879 kfree(meta);
880 }
881
meta_change_data(struct meta_value * dst,struct nlattr * nla)882 static inline int meta_change_data(struct meta_value *dst, struct nlattr *nla)
883 {
884 if (nla) {
885 if (nla_len(nla) == 0)
886 return -EINVAL;
887
888 return meta_type_ops(dst)->change(dst, nla);
889 }
890
891 return 0;
892 }
893
meta_is_supported(struct meta_value * val)894 static inline int meta_is_supported(struct meta_value *val)
895 {
896 return !meta_id(val) || meta_ops(val)->get;
897 }
898
899 static const struct nla_policy meta_policy[TCA_EM_META_MAX + 1] = {
900 [TCA_EM_META_HDR] = { .len = sizeof(struct tcf_meta_hdr) },
901 };
902
em_meta_change(struct net * net,void * data,int len,struct tcf_ematch * m)903 static int em_meta_change(struct net *net, void *data, int len,
904 struct tcf_ematch *m)
905 {
906 int err;
907 struct nlattr *tb[TCA_EM_META_MAX + 1];
908 struct tcf_meta_hdr *hdr;
909 struct meta_match *meta = NULL;
910
911 err = nla_parse_deprecated(tb, TCA_EM_META_MAX, data, len,
912 meta_policy, NULL);
913 if (err < 0)
914 goto errout;
915
916 err = -EINVAL;
917 if (tb[TCA_EM_META_HDR] == NULL)
918 goto errout;
919 hdr = nla_data(tb[TCA_EM_META_HDR]);
920
921 if (TCF_META_TYPE(hdr->left.kind) != TCF_META_TYPE(hdr->right.kind) ||
922 TCF_META_TYPE(hdr->left.kind) > TCF_META_TYPE_MAX ||
923 TCF_META_ID(hdr->left.kind) > TCF_META_ID_MAX ||
924 TCF_META_ID(hdr->right.kind) > TCF_META_ID_MAX)
925 goto errout;
926
927 meta = kzalloc(sizeof(*meta), GFP_KERNEL);
928 if (meta == NULL) {
929 err = -ENOMEM;
930 goto errout;
931 }
932
933 memcpy(&meta->lvalue.hdr, &hdr->left, sizeof(hdr->left));
934 memcpy(&meta->rvalue.hdr, &hdr->right, sizeof(hdr->right));
935
936 if (!meta_is_supported(&meta->lvalue) ||
937 !meta_is_supported(&meta->rvalue)) {
938 err = -EOPNOTSUPP;
939 goto errout;
940 }
941
942 if (meta_change_data(&meta->lvalue, tb[TCA_EM_META_LVALUE]) < 0 ||
943 meta_change_data(&meta->rvalue, tb[TCA_EM_META_RVALUE]) < 0)
944 goto errout;
945
946 m->datalen = sizeof(*meta);
947 m->data = (unsigned long) meta;
948
949 err = 0;
950 errout:
951 if (err && meta)
952 meta_delete(meta);
953 return err;
954 }
955
em_meta_destroy(struct tcf_ematch * m)956 static void em_meta_destroy(struct tcf_ematch *m)
957 {
958 if (m)
959 meta_delete((struct meta_match *) m->data);
960 }
961
em_meta_dump(struct sk_buff * skb,struct tcf_ematch * em)962 static int em_meta_dump(struct sk_buff *skb, struct tcf_ematch *em)
963 {
964 struct meta_match *meta = (struct meta_match *) em->data;
965 struct tcf_meta_hdr hdr;
966 const struct meta_type_ops *ops;
967
968 memset(&hdr, 0, sizeof(hdr));
969 memcpy(&hdr.left, &meta->lvalue.hdr, sizeof(hdr.left));
970 memcpy(&hdr.right, &meta->rvalue.hdr, sizeof(hdr.right));
971
972 if (nla_put(skb, TCA_EM_META_HDR, sizeof(hdr), &hdr))
973 goto nla_put_failure;
974
975 ops = meta_type_ops(&meta->lvalue);
976 if (ops->dump(skb, &meta->lvalue, TCA_EM_META_LVALUE) < 0 ||
977 ops->dump(skb, &meta->rvalue, TCA_EM_META_RVALUE) < 0)
978 goto nla_put_failure;
979
980 return 0;
981
982 nla_put_failure:
983 return -1;
984 }
985
986 static struct tcf_ematch_ops em_meta_ops = {
987 .kind = TCF_EM_META,
988 .change = em_meta_change,
989 .match = em_meta_match,
990 .destroy = em_meta_destroy,
991 .dump = em_meta_dump,
992 .owner = THIS_MODULE,
993 .link = LIST_HEAD_INIT(em_meta_ops.link)
994 };
995
init_em_meta(void)996 static int __init init_em_meta(void)
997 {
998 return tcf_em_register(&em_meta_ops);
999 }
1000
exit_em_meta(void)1001 static void __exit exit_em_meta(void)
1002 {
1003 tcf_em_unregister(&em_meta_ops);
1004 }
1005
1006 MODULE_LICENSE("GPL");
1007
1008 module_init(init_em_meta);
1009 module_exit(exit_em_meta);
1010
1011 MODULE_ALIAS_TCF_EMATCH(TCF_EM_META);
1012