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 functionality. 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 int bound_dev_if;
315
316 if (skip_nonlocal(skb)) {
317 *err = -1;
318 return;
319 }
320
321 bound_dev_if = READ_ONCE(skb->sk->sk_bound_dev_if);
322 if (bound_dev_if == 0) {
323 dst->value = (unsigned long) "any";
324 dst->len = 3;
325 } else {
326 struct net_device *dev;
327
328 rcu_read_lock();
329 dev = dev_get_by_index_rcu(sock_net(skb->sk),
330 bound_dev_if);
331 *err = var_dev(dev, dst);
332 rcu_read_unlock();
333 }
334 }
335
META_COLLECTOR(int_sk_refcnt)336 META_COLLECTOR(int_sk_refcnt)
337 {
338 if (skip_nonlocal(skb)) {
339 *err = -1;
340 return;
341 }
342 dst->value = refcount_read(&skb->sk->sk_refcnt);
343 }
344
META_COLLECTOR(int_sk_rcvbuf)345 META_COLLECTOR(int_sk_rcvbuf)
346 {
347 const struct sock *sk = skb_to_full_sk(skb);
348
349 if (!sk) {
350 *err = -1;
351 return;
352 }
353 dst->value = sk->sk_rcvbuf;
354 }
355
META_COLLECTOR(int_sk_shutdown)356 META_COLLECTOR(int_sk_shutdown)
357 {
358 const struct sock *sk = skb_to_full_sk(skb);
359
360 if (!sk) {
361 *err = -1;
362 return;
363 }
364 dst->value = sk->sk_shutdown;
365 }
366
META_COLLECTOR(int_sk_proto)367 META_COLLECTOR(int_sk_proto)
368 {
369 const struct sock *sk = skb_to_full_sk(skb);
370
371 if (!sk) {
372 *err = -1;
373 return;
374 }
375 dst->value = sk->sk_protocol;
376 }
377
META_COLLECTOR(int_sk_type)378 META_COLLECTOR(int_sk_type)
379 {
380 const struct sock *sk = skb_to_full_sk(skb);
381
382 if (!sk) {
383 *err = -1;
384 return;
385 }
386 dst->value = sk->sk_type;
387 }
388
META_COLLECTOR(int_sk_rmem_alloc)389 META_COLLECTOR(int_sk_rmem_alloc)
390 {
391 const struct sock *sk = skb_to_full_sk(skb);
392
393 if (!sk) {
394 *err = -1;
395 return;
396 }
397 dst->value = sk_rmem_alloc_get(sk);
398 }
399
META_COLLECTOR(int_sk_wmem_alloc)400 META_COLLECTOR(int_sk_wmem_alloc)
401 {
402 const struct sock *sk = skb_to_full_sk(skb);
403
404 if (!sk) {
405 *err = -1;
406 return;
407 }
408 dst->value = sk_wmem_alloc_get(sk);
409 }
410
META_COLLECTOR(int_sk_omem_alloc)411 META_COLLECTOR(int_sk_omem_alloc)
412 {
413 const struct sock *sk = skb_to_full_sk(skb);
414
415 if (!sk) {
416 *err = -1;
417 return;
418 }
419 dst->value = atomic_read(&sk->sk_omem_alloc);
420 }
421
META_COLLECTOR(int_sk_rcv_qlen)422 META_COLLECTOR(int_sk_rcv_qlen)
423 {
424 const struct sock *sk = skb_to_full_sk(skb);
425
426 if (!sk) {
427 *err = -1;
428 return;
429 }
430 dst->value = sk->sk_receive_queue.qlen;
431 }
432
META_COLLECTOR(int_sk_snd_qlen)433 META_COLLECTOR(int_sk_snd_qlen)
434 {
435 const struct sock *sk = skb_to_full_sk(skb);
436
437 if (!sk) {
438 *err = -1;
439 return;
440 }
441 dst->value = sk->sk_write_queue.qlen;
442 }
443
META_COLLECTOR(int_sk_wmem_queued)444 META_COLLECTOR(int_sk_wmem_queued)
445 {
446 const struct sock *sk = skb_to_full_sk(skb);
447
448 if (!sk) {
449 *err = -1;
450 return;
451 }
452 dst->value = READ_ONCE(sk->sk_wmem_queued);
453 }
454
META_COLLECTOR(int_sk_fwd_alloc)455 META_COLLECTOR(int_sk_fwd_alloc)
456 {
457 const struct sock *sk = skb_to_full_sk(skb);
458
459 if (!sk) {
460 *err = -1;
461 return;
462 }
463 dst->value = sk_forward_alloc_get(sk);
464 }
465
META_COLLECTOR(int_sk_sndbuf)466 META_COLLECTOR(int_sk_sndbuf)
467 {
468 const struct sock *sk = skb_to_full_sk(skb);
469
470 if (!sk) {
471 *err = -1;
472 return;
473 }
474 dst->value = sk->sk_sndbuf;
475 }
476
META_COLLECTOR(int_sk_alloc)477 META_COLLECTOR(int_sk_alloc)
478 {
479 const struct sock *sk = skb_to_full_sk(skb);
480
481 if (!sk) {
482 *err = -1;
483 return;
484 }
485 dst->value = (__force int) sk->sk_allocation;
486 }
487
META_COLLECTOR(int_sk_hash)488 META_COLLECTOR(int_sk_hash)
489 {
490 if (skip_nonlocal(skb)) {
491 *err = -1;
492 return;
493 }
494 dst->value = skb->sk->sk_hash;
495 }
496
META_COLLECTOR(int_sk_lingertime)497 META_COLLECTOR(int_sk_lingertime)
498 {
499 const struct sock *sk = skb_to_full_sk(skb);
500
501 if (!sk) {
502 *err = -1;
503 return;
504 }
505 dst->value = READ_ONCE(sk->sk_lingertime) / HZ;
506 }
507
META_COLLECTOR(int_sk_err_qlen)508 META_COLLECTOR(int_sk_err_qlen)
509 {
510 const struct sock *sk = skb_to_full_sk(skb);
511
512 if (!sk) {
513 *err = -1;
514 return;
515 }
516 dst->value = sk->sk_error_queue.qlen;
517 }
518
META_COLLECTOR(int_sk_ack_bl)519 META_COLLECTOR(int_sk_ack_bl)
520 {
521 const struct sock *sk = skb_to_full_sk(skb);
522
523 if (!sk) {
524 *err = -1;
525 return;
526 }
527 dst->value = READ_ONCE(sk->sk_ack_backlog);
528 }
529
META_COLLECTOR(int_sk_max_ack_bl)530 META_COLLECTOR(int_sk_max_ack_bl)
531 {
532 const struct sock *sk = skb_to_full_sk(skb);
533
534 if (!sk) {
535 *err = -1;
536 return;
537 }
538 dst->value = READ_ONCE(sk->sk_max_ack_backlog);
539 }
540
META_COLLECTOR(int_sk_prio)541 META_COLLECTOR(int_sk_prio)
542 {
543 const struct sock *sk = skb_to_full_sk(skb);
544
545 if (!sk) {
546 *err = -1;
547 return;
548 }
549 dst->value = READ_ONCE(sk->sk_priority);
550 }
551
META_COLLECTOR(int_sk_rcvlowat)552 META_COLLECTOR(int_sk_rcvlowat)
553 {
554 const struct sock *sk = skb_to_full_sk(skb);
555
556 if (!sk) {
557 *err = -1;
558 return;
559 }
560 dst->value = READ_ONCE(sk->sk_rcvlowat);
561 }
562
META_COLLECTOR(int_sk_rcvtimeo)563 META_COLLECTOR(int_sk_rcvtimeo)
564 {
565 const struct sock *sk = skb_to_full_sk(skb);
566
567 if (!sk) {
568 *err = -1;
569 return;
570 }
571 dst->value = READ_ONCE(sk->sk_rcvtimeo) / HZ;
572 }
573
META_COLLECTOR(int_sk_sndtimeo)574 META_COLLECTOR(int_sk_sndtimeo)
575 {
576 const struct sock *sk = skb_to_full_sk(skb);
577
578 if (!sk) {
579 *err = -1;
580 return;
581 }
582 dst->value = READ_ONCE(sk->sk_sndtimeo) / HZ;
583 }
584
META_COLLECTOR(int_sk_sendmsg_off)585 META_COLLECTOR(int_sk_sendmsg_off)
586 {
587 const struct sock *sk = skb_to_full_sk(skb);
588
589 if (!sk) {
590 *err = -1;
591 return;
592 }
593 dst->value = sk->sk_frag.offset;
594 }
595
META_COLLECTOR(int_sk_write_pend)596 META_COLLECTOR(int_sk_write_pend)
597 {
598 const struct sock *sk = skb_to_full_sk(skb);
599
600 if (!sk) {
601 *err = -1;
602 return;
603 }
604 dst->value = sk->sk_write_pending;
605 }
606
607 /**************************************************************************
608 * Meta value collectors assignment table
609 **************************************************************************/
610
611 struct meta_ops {
612 void (*get)(struct sk_buff *, struct tcf_pkt_info *,
613 struct meta_value *, struct meta_obj *, int *);
614 };
615
616 #define META_ID(name) TCF_META_ID_##name
617 #define META_FUNC(name) { .get = meta_##name }
618
619 /* Meta value operations table listing all meta value collectors and
620 * assigns them to a type and meta id. */
621 static struct meta_ops __meta_ops[TCF_META_TYPE_MAX + 1][TCF_META_ID_MAX + 1] = {
622 [TCF_META_TYPE_VAR] = {
623 [META_ID(DEV)] = META_FUNC(var_dev),
624 [META_ID(SK_BOUND_IF)] = META_FUNC(var_sk_bound_if),
625 },
626 [TCF_META_TYPE_INT] = {
627 [META_ID(RANDOM)] = META_FUNC(int_random),
628 [META_ID(LOADAVG_0)] = META_FUNC(int_loadavg_0),
629 [META_ID(LOADAVG_1)] = META_FUNC(int_loadavg_1),
630 [META_ID(LOADAVG_2)] = META_FUNC(int_loadavg_2),
631 [META_ID(DEV)] = META_FUNC(int_dev),
632 [META_ID(PRIORITY)] = META_FUNC(int_priority),
633 [META_ID(PROTOCOL)] = META_FUNC(int_protocol),
634 [META_ID(PKTTYPE)] = META_FUNC(int_pkttype),
635 [META_ID(PKTLEN)] = META_FUNC(int_pktlen),
636 [META_ID(DATALEN)] = META_FUNC(int_datalen),
637 [META_ID(MACLEN)] = META_FUNC(int_maclen),
638 [META_ID(NFMARK)] = META_FUNC(int_mark),
639 [META_ID(TCINDEX)] = META_FUNC(int_tcindex),
640 [META_ID(RTCLASSID)] = META_FUNC(int_rtclassid),
641 [META_ID(RTIIF)] = META_FUNC(int_rtiif),
642 [META_ID(SK_FAMILY)] = META_FUNC(int_sk_family),
643 [META_ID(SK_STATE)] = META_FUNC(int_sk_state),
644 [META_ID(SK_REUSE)] = META_FUNC(int_sk_reuse),
645 [META_ID(SK_BOUND_IF)] = META_FUNC(int_sk_bound_if),
646 [META_ID(SK_REFCNT)] = META_FUNC(int_sk_refcnt),
647 [META_ID(SK_RCVBUF)] = META_FUNC(int_sk_rcvbuf),
648 [META_ID(SK_SNDBUF)] = META_FUNC(int_sk_sndbuf),
649 [META_ID(SK_SHUTDOWN)] = META_FUNC(int_sk_shutdown),
650 [META_ID(SK_PROTO)] = META_FUNC(int_sk_proto),
651 [META_ID(SK_TYPE)] = META_FUNC(int_sk_type),
652 [META_ID(SK_RMEM_ALLOC)] = META_FUNC(int_sk_rmem_alloc),
653 [META_ID(SK_WMEM_ALLOC)] = META_FUNC(int_sk_wmem_alloc),
654 [META_ID(SK_OMEM_ALLOC)] = META_FUNC(int_sk_omem_alloc),
655 [META_ID(SK_WMEM_QUEUED)] = META_FUNC(int_sk_wmem_queued),
656 [META_ID(SK_RCV_QLEN)] = META_FUNC(int_sk_rcv_qlen),
657 [META_ID(SK_SND_QLEN)] = META_FUNC(int_sk_snd_qlen),
658 [META_ID(SK_ERR_QLEN)] = META_FUNC(int_sk_err_qlen),
659 [META_ID(SK_FORWARD_ALLOCS)] = META_FUNC(int_sk_fwd_alloc),
660 [META_ID(SK_ALLOCS)] = META_FUNC(int_sk_alloc),
661 [META_ID(SK_HASH)] = META_FUNC(int_sk_hash),
662 [META_ID(SK_LINGERTIME)] = META_FUNC(int_sk_lingertime),
663 [META_ID(SK_ACK_BACKLOG)] = META_FUNC(int_sk_ack_bl),
664 [META_ID(SK_MAX_ACK_BACKLOG)] = META_FUNC(int_sk_max_ack_bl),
665 [META_ID(SK_PRIO)] = META_FUNC(int_sk_prio),
666 [META_ID(SK_RCVLOWAT)] = META_FUNC(int_sk_rcvlowat),
667 [META_ID(SK_RCVTIMEO)] = META_FUNC(int_sk_rcvtimeo),
668 [META_ID(SK_SNDTIMEO)] = META_FUNC(int_sk_sndtimeo),
669 [META_ID(SK_SENDMSG_OFF)] = META_FUNC(int_sk_sendmsg_off),
670 [META_ID(SK_WRITE_PENDING)] = META_FUNC(int_sk_write_pend),
671 [META_ID(VLAN_TAG)] = META_FUNC(int_vlan_tag),
672 [META_ID(RXHASH)] = META_FUNC(int_rxhash),
673 }
674 };
675
meta_ops(struct meta_value * val)676 static inline struct meta_ops *meta_ops(struct meta_value *val)
677 {
678 return &__meta_ops[meta_type(val)][meta_id(val)];
679 }
680
681 /**************************************************************************
682 * Type specific operations for TCF_META_TYPE_VAR
683 **************************************************************************/
684
meta_var_compare(struct meta_obj * a,struct meta_obj * b)685 static int meta_var_compare(struct meta_obj *a, struct meta_obj *b)
686 {
687 int r = a->len - b->len;
688
689 if (r == 0)
690 r = memcmp((void *) a->value, (void *) b->value, a->len);
691
692 return r;
693 }
694
meta_var_change(struct meta_value * dst,struct nlattr * nla)695 static int meta_var_change(struct meta_value *dst, struct nlattr *nla)
696 {
697 int len = nla_len(nla);
698
699 dst->val = (unsigned long)kmemdup(nla_data(nla), len, GFP_KERNEL);
700 if (dst->val == 0UL)
701 return -ENOMEM;
702 dst->len = len;
703 return 0;
704 }
705
meta_var_destroy(struct meta_value * v)706 static void meta_var_destroy(struct meta_value *v)
707 {
708 kfree((void *) v->val);
709 }
710
meta_var_apply_extras(struct meta_value * v,struct meta_obj * dst)711 static void meta_var_apply_extras(struct meta_value *v,
712 struct meta_obj *dst)
713 {
714 int shift = v->hdr.shift;
715
716 if (shift && shift < dst->len)
717 dst->len -= shift;
718 }
719
meta_var_dump(struct sk_buff * skb,struct meta_value * v,int tlv)720 static int meta_var_dump(struct sk_buff *skb, struct meta_value *v, int tlv)
721 {
722 if (v->val && v->len &&
723 nla_put(skb, tlv, v->len, (void *) v->val))
724 goto nla_put_failure;
725 return 0;
726
727 nla_put_failure:
728 return -1;
729 }
730
731 /**************************************************************************
732 * Type specific operations for TCF_META_TYPE_INT
733 **************************************************************************/
734
meta_int_compare(struct meta_obj * a,struct meta_obj * b)735 static int meta_int_compare(struct meta_obj *a, struct meta_obj *b)
736 {
737 /* Let gcc optimize it, the unlikely is not really based on
738 * some numbers but jump free code for mismatches seems
739 * more logical. */
740 if (unlikely(a->value == b->value))
741 return 0;
742 else if (a->value < b->value)
743 return -1;
744 else
745 return 1;
746 }
747
meta_int_change(struct meta_value * dst,struct nlattr * nla)748 static int meta_int_change(struct meta_value *dst, struct nlattr *nla)
749 {
750 if (nla_len(nla) >= sizeof(unsigned long)) {
751 dst->val = *(unsigned long *) nla_data(nla);
752 dst->len = sizeof(unsigned long);
753 } else if (nla_len(nla) == sizeof(u32)) {
754 dst->val = nla_get_u32(nla);
755 dst->len = sizeof(u32);
756 } else
757 return -EINVAL;
758
759 return 0;
760 }
761
meta_int_apply_extras(struct meta_value * v,struct meta_obj * dst)762 static void meta_int_apply_extras(struct meta_value *v,
763 struct meta_obj *dst)
764 {
765 if (v->hdr.shift)
766 dst->value >>= v->hdr.shift;
767
768 if (v->val)
769 dst->value &= v->val;
770 }
771
meta_int_dump(struct sk_buff * skb,struct meta_value * v,int tlv)772 static int meta_int_dump(struct sk_buff *skb, struct meta_value *v, int tlv)
773 {
774 if (v->len == sizeof(unsigned long)) {
775 if (nla_put(skb, tlv, sizeof(unsigned long), &v->val))
776 goto nla_put_failure;
777 } else if (v->len == sizeof(u32)) {
778 if (nla_put_u32(skb, tlv, v->val))
779 goto nla_put_failure;
780 }
781
782 return 0;
783
784 nla_put_failure:
785 return -1;
786 }
787
788 /**************************************************************************
789 * Type specific operations table
790 **************************************************************************/
791
792 struct meta_type_ops {
793 void (*destroy)(struct meta_value *);
794 int (*compare)(struct meta_obj *, struct meta_obj *);
795 int (*change)(struct meta_value *, struct nlattr *);
796 void (*apply_extras)(struct meta_value *, struct meta_obj *);
797 int (*dump)(struct sk_buff *, struct meta_value *, int);
798 };
799
800 static const struct meta_type_ops __meta_type_ops[TCF_META_TYPE_MAX + 1] = {
801 [TCF_META_TYPE_VAR] = {
802 .destroy = meta_var_destroy,
803 .compare = meta_var_compare,
804 .change = meta_var_change,
805 .apply_extras = meta_var_apply_extras,
806 .dump = meta_var_dump
807 },
808 [TCF_META_TYPE_INT] = {
809 .compare = meta_int_compare,
810 .change = meta_int_change,
811 .apply_extras = meta_int_apply_extras,
812 .dump = meta_int_dump
813 }
814 };
815
meta_type_ops(struct meta_value * v)816 static inline const struct meta_type_ops *meta_type_ops(struct meta_value *v)
817 {
818 return &__meta_type_ops[meta_type(v)];
819 }
820
821 /**************************************************************************
822 * Core
823 **************************************************************************/
824
meta_get(struct sk_buff * skb,struct tcf_pkt_info * info,struct meta_value * v,struct meta_obj * dst)825 static int meta_get(struct sk_buff *skb, struct tcf_pkt_info *info,
826 struct meta_value *v, struct meta_obj *dst)
827 {
828 int err = 0;
829
830 if (meta_id(v) == TCF_META_ID_VALUE) {
831 dst->value = v->val;
832 dst->len = v->len;
833 return 0;
834 }
835
836 meta_ops(v)->get(skb, info, v, dst, &err);
837 if (err < 0)
838 return err;
839
840 if (meta_type_ops(v)->apply_extras)
841 meta_type_ops(v)->apply_extras(v, dst);
842
843 return 0;
844 }
845
em_meta_match(struct sk_buff * skb,struct tcf_ematch * m,struct tcf_pkt_info * info)846 static int em_meta_match(struct sk_buff *skb, struct tcf_ematch *m,
847 struct tcf_pkt_info *info)
848 {
849 int r;
850 struct meta_match *meta = (struct meta_match *) m->data;
851 struct meta_obj l_value, r_value;
852
853 if (meta_get(skb, info, &meta->lvalue, &l_value) < 0 ||
854 meta_get(skb, info, &meta->rvalue, &r_value) < 0)
855 return 0;
856
857 r = meta_type_ops(&meta->lvalue)->compare(&l_value, &r_value);
858
859 switch (meta->lvalue.hdr.op) {
860 case TCF_EM_OPND_EQ:
861 return !r;
862 case TCF_EM_OPND_LT:
863 return r < 0;
864 case TCF_EM_OPND_GT:
865 return r > 0;
866 }
867
868 return 0;
869 }
870
meta_delete(struct meta_match * meta)871 static void meta_delete(struct meta_match *meta)
872 {
873 if (meta) {
874 const struct meta_type_ops *ops = meta_type_ops(&meta->lvalue);
875
876 if (ops && ops->destroy) {
877 ops->destroy(&meta->lvalue);
878 ops->destroy(&meta->rvalue);
879 }
880 }
881
882 kfree(meta);
883 }
884
meta_change_data(struct meta_value * dst,struct nlattr * nla)885 static inline int meta_change_data(struct meta_value *dst, struct nlattr *nla)
886 {
887 if (nla) {
888 if (nla_len(nla) == 0)
889 return -EINVAL;
890
891 return meta_type_ops(dst)->change(dst, nla);
892 }
893
894 return 0;
895 }
896
meta_is_supported(struct meta_value * val)897 static inline int meta_is_supported(struct meta_value *val)
898 {
899 return !meta_id(val) || meta_ops(val)->get;
900 }
901
902 static const struct nla_policy meta_policy[TCA_EM_META_MAX + 1] = {
903 [TCA_EM_META_HDR] = { .len = sizeof(struct tcf_meta_hdr) },
904 };
905
em_meta_change(struct net * net,void * data,int len,struct tcf_ematch * m)906 static int em_meta_change(struct net *net, void *data, int len,
907 struct tcf_ematch *m)
908 {
909 int err;
910 struct nlattr *tb[TCA_EM_META_MAX + 1];
911 struct tcf_meta_hdr *hdr;
912 struct meta_match *meta = NULL;
913
914 err = nla_parse_deprecated(tb, TCA_EM_META_MAX, data, len,
915 meta_policy, NULL);
916 if (err < 0)
917 goto errout;
918
919 err = -EINVAL;
920 if (tb[TCA_EM_META_HDR] == NULL)
921 goto errout;
922 hdr = nla_data(tb[TCA_EM_META_HDR]);
923
924 if (TCF_META_TYPE(hdr->left.kind) != TCF_META_TYPE(hdr->right.kind) ||
925 TCF_META_TYPE(hdr->left.kind) > TCF_META_TYPE_MAX ||
926 TCF_META_ID(hdr->left.kind) > TCF_META_ID_MAX ||
927 TCF_META_ID(hdr->right.kind) > TCF_META_ID_MAX)
928 goto errout;
929
930 meta = kzalloc(sizeof(*meta), GFP_KERNEL);
931 if (meta == NULL) {
932 err = -ENOMEM;
933 goto errout;
934 }
935
936 memcpy(&meta->lvalue.hdr, &hdr->left, sizeof(hdr->left));
937 memcpy(&meta->rvalue.hdr, &hdr->right, sizeof(hdr->right));
938
939 if (!meta_is_supported(&meta->lvalue) ||
940 !meta_is_supported(&meta->rvalue)) {
941 err = -EOPNOTSUPP;
942 goto errout;
943 }
944
945 if (meta_change_data(&meta->lvalue, tb[TCA_EM_META_LVALUE]) < 0 ||
946 meta_change_data(&meta->rvalue, tb[TCA_EM_META_RVALUE]) < 0)
947 goto errout;
948
949 m->datalen = sizeof(*meta);
950 m->data = (unsigned long) meta;
951
952 err = 0;
953 errout:
954 if (err && meta)
955 meta_delete(meta);
956 return err;
957 }
958
em_meta_destroy(struct tcf_ematch * m)959 static void em_meta_destroy(struct tcf_ematch *m)
960 {
961 if (m)
962 meta_delete((struct meta_match *) m->data);
963 }
964
em_meta_dump(struct sk_buff * skb,struct tcf_ematch * em)965 static int em_meta_dump(struct sk_buff *skb, struct tcf_ematch *em)
966 {
967 struct meta_match *meta = (struct meta_match *) em->data;
968 struct tcf_meta_hdr hdr;
969 const struct meta_type_ops *ops;
970
971 memset(&hdr, 0, sizeof(hdr));
972 memcpy(&hdr.left, &meta->lvalue.hdr, sizeof(hdr.left));
973 memcpy(&hdr.right, &meta->rvalue.hdr, sizeof(hdr.right));
974
975 if (nla_put(skb, TCA_EM_META_HDR, sizeof(hdr), &hdr))
976 goto nla_put_failure;
977
978 ops = meta_type_ops(&meta->lvalue);
979 if (ops->dump(skb, &meta->lvalue, TCA_EM_META_LVALUE) < 0 ||
980 ops->dump(skb, &meta->rvalue, TCA_EM_META_RVALUE) < 0)
981 goto nla_put_failure;
982
983 return 0;
984
985 nla_put_failure:
986 return -1;
987 }
988
989 static struct tcf_ematch_ops em_meta_ops = {
990 .kind = TCF_EM_META,
991 .change = em_meta_change,
992 .match = em_meta_match,
993 .destroy = em_meta_destroy,
994 .dump = em_meta_dump,
995 .owner = THIS_MODULE,
996 .link = LIST_HEAD_INIT(em_meta_ops.link)
997 };
998
init_em_meta(void)999 static int __init init_em_meta(void)
1000 {
1001 return tcf_em_register(&em_meta_ops);
1002 }
1003
exit_em_meta(void)1004 static void __exit exit_em_meta(void)
1005 {
1006 tcf_em_unregister(&em_meta_ops);
1007 }
1008
1009 MODULE_DESCRIPTION("ematch classifier for various internal kernel metadata, skb metadata and sk metadata");
1010 MODULE_LICENSE("GPL");
1011
1012 module_init(init_em_meta);
1013 module_exit(exit_em_meta);
1014
1015 MODULE_ALIAS_TCF_EMATCH(TCF_EM_META);
1016