[NET_SCHED]: Use nla_policy for attribute validation in actions
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / sched / em_meta.c
1 /*
2 * net/sched/em_meta.c Metadata ematch
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: Thomas Graf <tgraf@suug.ch>
10 *
11 * ==========================================================================
12 *
13 * The metadata ematch compares two meta objects where each object
14 * represents either a meta value stored in the kernel or a static
15 * value provided by userspace. The objects are not provided by
16 * userspace itself but rather a definition providing the information
17 * to build them. Every object is of a certain type which must be
18 * equal to the object it is being compared to.
19 *
20 * The definition of a objects conists of the type (meta type), a
21 * identifier (meta id) and additional type specific information.
22 * The meta id is either TCF_META_TYPE_VALUE for values provided by
23 * userspace or a index to the meta operations table consisting of
24 * function pointers to type specific meta data collectors returning
25 * the value of the requested meta value.
26 *
27 * lvalue rvalue
28 * +-----------+ +-----------+
29 * | type: INT | | type: INT |
30 * def | id: DEV | | id: VALUE |
31 * | data: | | data: 3 |
32 * +-----------+ +-----------+
33 * | |
34 * ---> meta_ops[INT][DEV](...) |
35 * | |
36 * ----------- |
37 * V V
38 * +-----------+ +-----------+
39 * | type: INT | | type: INT |
40 * obj | id: DEV | | id: VALUE |
41 * | data: 2 |<--data got filled out | data: 3 |
42 * +-----------+ +-----------+
43 * | |
44 * --------------> 2 equals 3 <--------------
45 *
46 * This is a simplified schema, the complexity varies depending
47 * on the meta type. Obviously, the length of the data must also
48 * be provided for non-numeric types.
49 *
50 * Additionaly, type dependant modifiers such as shift operators
51 * or mask may be applied to extend the functionaliy. As of now,
52 * the variable length type supports shifting the byte string to
53 * the right, eating up any number of octets and thus supporting
54 * wildcard interface name comparisons such as "ppp%" matching
55 * ppp0..9.
56 *
57 * NOTE: Certain meta values depend on other subsystems and are
58 * only available if that subsystem is enabled in the kernel.
59 */
60
61 #include <linux/module.h>
62 #include <linux/types.h>
63 #include <linux/kernel.h>
64 #include <linux/sched.h>
65 #include <linux/string.h>
66 #include <linux/skbuff.h>
67 #include <linux/random.h>
68 #include <linux/tc_ematch/tc_em_meta.h>
69 #include <net/dst.h>
70 #include <net/route.h>
71 #include <net/pkt_cls.h>
72 #include <net/sock.h>
73
74 struct meta_obj
75 {
76 unsigned long value;
77 unsigned int len;
78 };
79
80 struct meta_value
81 {
82 struct tcf_meta_val hdr;
83 unsigned long val;
84 unsigned int len;
85 };
86
87 struct meta_match
88 {
89 struct meta_value lvalue;
90 struct meta_value rvalue;
91 };
92
93 static inline int meta_id(struct meta_value *v)
94 {
95 return TCF_META_ID(v->hdr.kind);
96 }
97
98 static inline int meta_type(struct meta_value *v)
99 {
100 return TCF_META_TYPE(v->hdr.kind);
101 }
102
103 #define META_COLLECTOR(FUNC) static void meta_##FUNC(struct sk_buff *skb, \
104 struct tcf_pkt_info *info, struct meta_value *v, \
105 struct meta_obj *dst, int *err)
106
107 /**************************************************************************
108 * System status & misc
109 **************************************************************************/
110
111 META_COLLECTOR(int_random)
112 {
113 get_random_bytes(&dst->value, sizeof(dst->value));
114 }
115
116 static inline unsigned long fixed_loadavg(int load)
117 {
118 int rnd_load = load + (FIXED_1/200);
119 int rnd_frac = ((rnd_load & (FIXED_1-1)) * 100) >> FSHIFT;
120
121 return ((rnd_load >> FSHIFT) * 100) + rnd_frac;
122 }
123
124 META_COLLECTOR(int_loadavg_0)
125 {
126 dst->value = fixed_loadavg(avenrun[0]);
127 }
128
129 META_COLLECTOR(int_loadavg_1)
130 {
131 dst->value = fixed_loadavg(avenrun[1]);
132 }
133
134 META_COLLECTOR(int_loadavg_2)
135 {
136 dst->value = fixed_loadavg(avenrun[2]);
137 }
138
139 /**************************************************************************
140 * Device names & indices
141 **************************************************************************/
142
143 static inline int int_dev(struct net_device *dev, struct meta_obj *dst)
144 {
145 if (unlikely(dev == NULL))
146 return -1;
147
148 dst->value = dev->ifindex;
149 return 0;
150 }
151
152 static inline int var_dev(struct net_device *dev, struct meta_obj *dst)
153 {
154 if (unlikely(dev == NULL))
155 return -1;
156
157 dst->value = (unsigned long) dev->name;
158 dst->len = strlen(dev->name);
159 return 0;
160 }
161
162 META_COLLECTOR(int_dev)
163 {
164 *err = int_dev(skb->dev, dst);
165 }
166
167 META_COLLECTOR(var_dev)
168 {
169 *err = var_dev(skb->dev, dst);
170 }
171
172 /**************************************************************************
173 * skb attributes
174 **************************************************************************/
175
176 META_COLLECTOR(int_priority)
177 {
178 dst->value = skb->priority;
179 }
180
181 META_COLLECTOR(int_protocol)
182 {
183 /* Let userspace take care of the byte ordering */
184 dst->value = skb->protocol;
185 }
186
187 META_COLLECTOR(int_pkttype)
188 {
189 dst->value = skb->pkt_type;
190 }
191
192 META_COLLECTOR(int_pktlen)
193 {
194 dst->value = skb->len;
195 }
196
197 META_COLLECTOR(int_datalen)
198 {
199 dst->value = skb->data_len;
200 }
201
202 META_COLLECTOR(int_maclen)
203 {
204 dst->value = skb->mac_len;
205 }
206
207 /**************************************************************************
208 * Netfilter
209 **************************************************************************/
210
211 META_COLLECTOR(int_mark)
212 {
213 dst->value = skb->mark;
214 }
215
216 /**************************************************************************
217 * Traffic Control
218 **************************************************************************/
219
220 META_COLLECTOR(int_tcindex)
221 {
222 dst->value = skb->tc_index;
223 }
224
225 /**************************************************************************
226 * Routing
227 **************************************************************************/
228
229 META_COLLECTOR(int_rtclassid)
230 {
231 if (unlikely(skb->dst == NULL))
232 *err = -1;
233 else
234 #ifdef CONFIG_NET_CLS_ROUTE
235 dst->value = skb->dst->tclassid;
236 #else
237 dst->value = 0;
238 #endif
239 }
240
241 META_COLLECTOR(int_rtiif)
242 {
243 if (unlikely(skb->dst == NULL))
244 *err = -1;
245 else
246 dst->value = ((struct rtable*) skb->dst)->fl.iif;
247 }
248
249 /**************************************************************************
250 * Socket Attributes
251 **************************************************************************/
252
253 #define SKIP_NONLOCAL(skb) \
254 if (unlikely(skb->sk == NULL)) { \
255 *err = -1; \
256 return; \
257 }
258
259 META_COLLECTOR(int_sk_family)
260 {
261 SKIP_NONLOCAL(skb);
262 dst->value = skb->sk->sk_family;
263 }
264
265 META_COLLECTOR(int_sk_state)
266 {
267 SKIP_NONLOCAL(skb);
268 dst->value = skb->sk->sk_state;
269 }
270
271 META_COLLECTOR(int_sk_reuse)
272 {
273 SKIP_NONLOCAL(skb);
274 dst->value = skb->sk->sk_reuse;
275 }
276
277 META_COLLECTOR(int_sk_bound_if)
278 {
279 SKIP_NONLOCAL(skb);
280 /* No error if bound_dev_if is 0, legal userspace check */
281 dst->value = skb->sk->sk_bound_dev_if;
282 }
283
284 META_COLLECTOR(var_sk_bound_if)
285 {
286 SKIP_NONLOCAL(skb);
287
288 if (skb->sk->sk_bound_dev_if == 0) {
289 dst->value = (unsigned long) "any";
290 dst->len = 3;
291 } else {
292 struct net_device *dev;
293
294 dev = dev_get_by_index(&init_net, skb->sk->sk_bound_dev_if);
295 *err = var_dev(dev, dst);
296 if (dev)
297 dev_put(dev);
298 }
299 }
300
301 META_COLLECTOR(int_sk_refcnt)
302 {
303 SKIP_NONLOCAL(skb);
304 dst->value = atomic_read(&skb->sk->sk_refcnt);
305 }
306
307 META_COLLECTOR(int_sk_rcvbuf)
308 {
309 SKIP_NONLOCAL(skb);
310 dst->value = skb->sk->sk_rcvbuf;
311 }
312
313 META_COLLECTOR(int_sk_shutdown)
314 {
315 SKIP_NONLOCAL(skb);
316 dst->value = skb->sk->sk_shutdown;
317 }
318
319 META_COLLECTOR(int_sk_proto)
320 {
321 SKIP_NONLOCAL(skb);
322 dst->value = skb->sk->sk_protocol;
323 }
324
325 META_COLLECTOR(int_sk_type)
326 {
327 SKIP_NONLOCAL(skb);
328 dst->value = skb->sk->sk_type;
329 }
330
331 META_COLLECTOR(int_sk_rmem_alloc)
332 {
333 SKIP_NONLOCAL(skb);
334 dst->value = atomic_read(&skb->sk->sk_rmem_alloc);
335 }
336
337 META_COLLECTOR(int_sk_wmem_alloc)
338 {
339 SKIP_NONLOCAL(skb);
340 dst->value = atomic_read(&skb->sk->sk_wmem_alloc);
341 }
342
343 META_COLLECTOR(int_sk_omem_alloc)
344 {
345 SKIP_NONLOCAL(skb);
346 dst->value = atomic_read(&skb->sk->sk_omem_alloc);
347 }
348
349 META_COLLECTOR(int_sk_rcv_qlen)
350 {
351 SKIP_NONLOCAL(skb);
352 dst->value = skb->sk->sk_receive_queue.qlen;
353 }
354
355 META_COLLECTOR(int_sk_snd_qlen)
356 {
357 SKIP_NONLOCAL(skb);
358 dst->value = skb->sk->sk_write_queue.qlen;
359 }
360
361 META_COLLECTOR(int_sk_wmem_queued)
362 {
363 SKIP_NONLOCAL(skb);
364 dst->value = skb->sk->sk_wmem_queued;
365 }
366
367 META_COLLECTOR(int_sk_fwd_alloc)
368 {
369 SKIP_NONLOCAL(skb);
370 dst->value = skb->sk->sk_forward_alloc;
371 }
372
373 META_COLLECTOR(int_sk_sndbuf)
374 {
375 SKIP_NONLOCAL(skb);
376 dst->value = skb->sk->sk_sndbuf;
377 }
378
379 META_COLLECTOR(int_sk_alloc)
380 {
381 SKIP_NONLOCAL(skb);
382 dst->value = skb->sk->sk_allocation;
383 }
384
385 META_COLLECTOR(int_sk_route_caps)
386 {
387 SKIP_NONLOCAL(skb);
388 dst->value = skb->sk->sk_route_caps;
389 }
390
391 META_COLLECTOR(int_sk_hash)
392 {
393 SKIP_NONLOCAL(skb);
394 dst->value = skb->sk->sk_hash;
395 }
396
397 META_COLLECTOR(int_sk_lingertime)
398 {
399 SKIP_NONLOCAL(skb);
400 dst->value = skb->sk->sk_lingertime / HZ;
401 }
402
403 META_COLLECTOR(int_sk_err_qlen)
404 {
405 SKIP_NONLOCAL(skb);
406 dst->value = skb->sk->sk_error_queue.qlen;
407 }
408
409 META_COLLECTOR(int_sk_ack_bl)
410 {
411 SKIP_NONLOCAL(skb);
412 dst->value = skb->sk->sk_ack_backlog;
413 }
414
415 META_COLLECTOR(int_sk_max_ack_bl)
416 {
417 SKIP_NONLOCAL(skb);
418 dst->value = skb->sk->sk_max_ack_backlog;
419 }
420
421 META_COLLECTOR(int_sk_prio)
422 {
423 SKIP_NONLOCAL(skb);
424 dst->value = skb->sk->sk_priority;
425 }
426
427 META_COLLECTOR(int_sk_rcvlowat)
428 {
429 SKIP_NONLOCAL(skb);
430 dst->value = skb->sk->sk_rcvlowat;
431 }
432
433 META_COLLECTOR(int_sk_rcvtimeo)
434 {
435 SKIP_NONLOCAL(skb);
436 dst->value = skb->sk->sk_rcvtimeo / HZ;
437 }
438
439 META_COLLECTOR(int_sk_sndtimeo)
440 {
441 SKIP_NONLOCAL(skb);
442 dst->value = skb->sk->sk_sndtimeo / HZ;
443 }
444
445 META_COLLECTOR(int_sk_sendmsg_off)
446 {
447 SKIP_NONLOCAL(skb);
448 dst->value = skb->sk->sk_sndmsg_off;
449 }
450
451 META_COLLECTOR(int_sk_write_pend)
452 {
453 SKIP_NONLOCAL(skb);
454 dst->value = skb->sk->sk_write_pending;
455 }
456
457 /**************************************************************************
458 * Meta value collectors assignment table
459 **************************************************************************/
460
461 struct meta_ops
462 {
463 void (*get)(struct sk_buff *, struct tcf_pkt_info *,
464 struct meta_value *, struct meta_obj *, int *);
465 };
466
467 #define META_ID(name) TCF_META_ID_##name
468 #define META_FUNC(name) { .get = meta_##name }
469
470 /* Meta value operations table listing all meta value collectors and
471 * assigns them to a type and meta id. */
472 static struct meta_ops __meta_ops[TCF_META_TYPE_MAX+1][TCF_META_ID_MAX+1] = {
473 [TCF_META_TYPE_VAR] = {
474 [META_ID(DEV)] = META_FUNC(var_dev),
475 [META_ID(SK_BOUND_IF)] = META_FUNC(var_sk_bound_if),
476 },
477 [TCF_META_TYPE_INT] = {
478 [META_ID(RANDOM)] = META_FUNC(int_random),
479 [META_ID(LOADAVG_0)] = META_FUNC(int_loadavg_0),
480 [META_ID(LOADAVG_1)] = META_FUNC(int_loadavg_1),
481 [META_ID(LOADAVG_2)] = META_FUNC(int_loadavg_2),
482 [META_ID(DEV)] = META_FUNC(int_dev),
483 [META_ID(PRIORITY)] = META_FUNC(int_priority),
484 [META_ID(PROTOCOL)] = META_FUNC(int_protocol),
485 [META_ID(PKTTYPE)] = META_FUNC(int_pkttype),
486 [META_ID(PKTLEN)] = META_FUNC(int_pktlen),
487 [META_ID(DATALEN)] = META_FUNC(int_datalen),
488 [META_ID(MACLEN)] = META_FUNC(int_maclen),
489 [META_ID(NFMARK)] = META_FUNC(int_mark),
490 [META_ID(TCINDEX)] = META_FUNC(int_tcindex),
491 [META_ID(RTCLASSID)] = META_FUNC(int_rtclassid),
492 [META_ID(RTIIF)] = META_FUNC(int_rtiif),
493 [META_ID(SK_FAMILY)] = META_FUNC(int_sk_family),
494 [META_ID(SK_STATE)] = META_FUNC(int_sk_state),
495 [META_ID(SK_REUSE)] = META_FUNC(int_sk_reuse),
496 [META_ID(SK_BOUND_IF)] = META_FUNC(int_sk_bound_if),
497 [META_ID(SK_REFCNT)] = META_FUNC(int_sk_refcnt),
498 [META_ID(SK_RCVBUF)] = META_FUNC(int_sk_rcvbuf),
499 [META_ID(SK_SNDBUF)] = META_FUNC(int_sk_sndbuf),
500 [META_ID(SK_SHUTDOWN)] = META_FUNC(int_sk_shutdown),
501 [META_ID(SK_PROTO)] = META_FUNC(int_sk_proto),
502 [META_ID(SK_TYPE)] = META_FUNC(int_sk_type),
503 [META_ID(SK_RMEM_ALLOC)] = META_FUNC(int_sk_rmem_alloc),
504 [META_ID(SK_WMEM_ALLOC)] = META_FUNC(int_sk_wmem_alloc),
505 [META_ID(SK_OMEM_ALLOC)] = META_FUNC(int_sk_omem_alloc),
506 [META_ID(SK_WMEM_QUEUED)] = META_FUNC(int_sk_wmem_queued),
507 [META_ID(SK_RCV_QLEN)] = META_FUNC(int_sk_rcv_qlen),
508 [META_ID(SK_SND_QLEN)] = META_FUNC(int_sk_snd_qlen),
509 [META_ID(SK_ERR_QLEN)] = META_FUNC(int_sk_err_qlen),
510 [META_ID(SK_FORWARD_ALLOCS)] = META_FUNC(int_sk_fwd_alloc),
511 [META_ID(SK_ALLOCS)] = META_FUNC(int_sk_alloc),
512 [META_ID(SK_ROUTE_CAPS)] = META_FUNC(int_sk_route_caps),
513 [META_ID(SK_HASH)] = META_FUNC(int_sk_hash),
514 [META_ID(SK_LINGERTIME)] = META_FUNC(int_sk_lingertime),
515 [META_ID(SK_ACK_BACKLOG)] = META_FUNC(int_sk_ack_bl),
516 [META_ID(SK_MAX_ACK_BACKLOG)] = META_FUNC(int_sk_max_ack_bl),
517 [META_ID(SK_PRIO)] = META_FUNC(int_sk_prio),
518 [META_ID(SK_RCVLOWAT)] = META_FUNC(int_sk_rcvlowat),
519 [META_ID(SK_RCVTIMEO)] = META_FUNC(int_sk_rcvtimeo),
520 [META_ID(SK_SNDTIMEO)] = META_FUNC(int_sk_sndtimeo),
521 [META_ID(SK_SENDMSG_OFF)] = META_FUNC(int_sk_sendmsg_off),
522 [META_ID(SK_WRITE_PENDING)] = META_FUNC(int_sk_write_pend),
523 }
524 };
525
526 static inline struct meta_ops * meta_ops(struct meta_value *val)
527 {
528 return &__meta_ops[meta_type(val)][meta_id(val)];
529 }
530
531 /**************************************************************************
532 * Type specific operations for TCF_META_TYPE_VAR
533 **************************************************************************/
534
535 static int meta_var_compare(struct meta_obj *a, struct meta_obj *b)
536 {
537 int r = a->len - b->len;
538
539 if (r == 0)
540 r = memcmp((void *) a->value, (void *) b->value, a->len);
541
542 return r;
543 }
544
545 static int meta_var_change(struct meta_value *dst, struct nlattr *nla)
546 {
547 int len = nla_len(nla);
548
549 dst->val = (unsigned long)kmemdup(nla_data(nla), len, GFP_KERNEL);
550 if (dst->val == 0UL)
551 return -ENOMEM;
552 dst->len = len;
553 return 0;
554 }
555
556 static void meta_var_destroy(struct meta_value *v)
557 {
558 kfree((void *) v->val);
559 }
560
561 static void meta_var_apply_extras(struct meta_value *v,
562 struct meta_obj *dst)
563 {
564 int shift = v->hdr.shift;
565
566 if (shift && shift < dst->len)
567 dst->len -= shift;
568 }
569
570 static int meta_var_dump(struct sk_buff *skb, struct meta_value *v, int tlv)
571 {
572 if (v->val && v->len)
573 NLA_PUT(skb, tlv, v->len, (void *) v->val);
574 return 0;
575
576 nla_put_failure:
577 return -1;
578 }
579
580 /**************************************************************************
581 * Type specific operations for TCF_META_TYPE_INT
582 **************************************************************************/
583
584 static int meta_int_compare(struct meta_obj *a, struct meta_obj *b)
585 {
586 /* Let gcc optimize it, the unlikely is not really based on
587 * some numbers but jump free code for mismatches seems
588 * more logical. */
589 if (unlikely(a->value == b->value))
590 return 0;
591 else if (a->value < b->value)
592 return -1;
593 else
594 return 1;
595 }
596
597 static int meta_int_change(struct meta_value *dst, struct nlattr *nla)
598 {
599 if (nla_len(nla) >= sizeof(unsigned long)) {
600 dst->val = *(unsigned long *) nla_data(nla);
601 dst->len = sizeof(unsigned long);
602 } else if (nla_len(nla) == sizeof(u32)) {
603 dst->val = nla_get_u32(nla);
604 dst->len = sizeof(u32);
605 } else
606 return -EINVAL;
607
608 return 0;
609 }
610
611 static void meta_int_apply_extras(struct meta_value *v,
612 struct meta_obj *dst)
613 {
614 if (v->hdr.shift)
615 dst->value >>= v->hdr.shift;
616
617 if (v->val)
618 dst->value &= v->val;
619 }
620
621 static int meta_int_dump(struct sk_buff *skb, struct meta_value *v, int tlv)
622 {
623 if (v->len == sizeof(unsigned long))
624 NLA_PUT(skb, tlv, sizeof(unsigned long), &v->val);
625 else if (v->len == sizeof(u32)) {
626 NLA_PUT_U32(skb, tlv, v->val);
627 }
628
629 return 0;
630
631 nla_put_failure:
632 return -1;
633 }
634
635 /**************************************************************************
636 * Type specific operations table
637 **************************************************************************/
638
639 struct meta_type_ops
640 {
641 void (*destroy)(struct meta_value *);
642 int (*compare)(struct meta_obj *, struct meta_obj *);
643 int (*change)(struct meta_value *, struct nlattr *);
644 void (*apply_extras)(struct meta_value *, struct meta_obj *);
645 int (*dump)(struct sk_buff *, struct meta_value *, int);
646 };
647
648 static struct meta_type_ops __meta_type_ops[TCF_META_TYPE_MAX+1] = {
649 [TCF_META_TYPE_VAR] = {
650 .destroy = meta_var_destroy,
651 .compare = meta_var_compare,
652 .change = meta_var_change,
653 .apply_extras = meta_var_apply_extras,
654 .dump = meta_var_dump
655 },
656 [TCF_META_TYPE_INT] = {
657 .compare = meta_int_compare,
658 .change = meta_int_change,
659 .apply_extras = meta_int_apply_extras,
660 .dump = meta_int_dump
661 }
662 };
663
664 static inline struct meta_type_ops * meta_type_ops(struct meta_value *v)
665 {
666 return &__meta_type_ops[meta_type(v)];
667 }
668
669 /**************************************************************************
670 * Core
671 **************************************************************************/
672
673 static inline int meta_get(struct sk_buff *skb, struct tcf_pkt_info *info,
674 struct meta_value *v, struct meta_obj *dst)
675 {
676 int err = 0;
677
678 if (meta_id(v) == TCF_META_ID_VALUE) {
679 dst->value = v->val;
680 dst->len = v->len;
681 return 0;
682 }
683
684 meta_ops(v)->get(skb, info, v, dst, &err);
685 if (err < 0)
686 return err;
687
688 if (meta_type_ops(v)->apply_extras)
689 meta_type_ops(v)->apply_extras(v, dst);
690
691 return 0;
692 }
693
694 static int em_meta_match(struct sk_buff *skb, struct tcf_ematch *m,
695 struct tcf_pkt_info *info)
696 {
697 int r;
698 struct meta_match *meta = (struct meta_match *) m->data;
699 struct meta_obj l_value, r_value;
700
701 if (meta_get(skb, info, &meta->lvalue, &l_value) < 0 ||
702 meta_get(skb, info, &meta->rvalue, &r_value) < 0)
703 return 0;
704
705 r = meta_type_ops(&meta->lvalue)->compare(&l_value, &r_value);
706
707 switch (meta->lvalue.hdr.op) {
708 case TCF_EM_OPND_EQ:
709 return !r;
710 case TCF_EM_OPND_LT:
711 return r < 0;
712 case TCF_EM_OPND_GT:
713 return r > 0;
714 }
715
716 return 0;
717 }
718
719 static inline void meta_delete(struct meta_match *meta)
720 {
721 struct meta_type_ops *ops = meta_type_ops(&meta->lvalue);
722
723 if (ops && ops->destroy) {
724 ops->destroy(&meta->lvalue);
725 ops->destroy(&meta->rvalue);
726 }
727
728 kfree(meta);
729 }
730
731 static inline int meta_change_data(struct meta_value *dst, struct nlattr *nla)
732 {
733 if (nla) {
734 if (nla_len(nla) == 0)
735 return -EINVAL;
736
737 return meta_type_ops(dst)->change(dst, nla);
738 }
739
740 return 0;
741 }
742
743 static inline int meta_is_supported(struct meta_value *val)
744 {
745 return (!meta_id(val) || meta_ops(val)->get);
746 }
747
748 static int em_meta_change(struct tcf_proto *tp, void *data, int len,
749 struct tcf_ematch *m)
750 {
751 int err;
752 struct nlattr *tb[TCA_EM_META_MAX + 1];
753 struct tcf_meta_hdr *hdr;
754 struct meta_match *meta = NULL;
755
756 err = nla_parse(tb, TCA_EM_META_MAX, data, len, NULL);
757 if (err < 0)
758 goto errout;
759
760 err = -EINVAL;
761 if (tb[TCA_EM_META_HDR] == NULL ||
762 nla_len(tb[TCA_EM_META_HDR]) < sizeof(*hdr))
763 goto errout;
764 hdr = nla_data(tb[TCA_EM_META_HDR]);
765
766 if (TCF_META_TYPE(hdr->left.kind) != TCF_META_TYPE(hdr->right.kind) ||
767 TCF_META_TYPE(hdr->left.kind) > TCF_META_TYPE_MAX ||
768 TCF_META_ID(hdr->left.kind) > TCF_META_ID_MAX ||
769 TCF_META_ID(hdr->right.kind) > TCF_META_ID_MAX)
770 goto errout;
771
772 meta = kzalloc(sizeof(*meta), GFP_KERNEL);
773 if (meta == NULL)
774 goto errout;
775
776 memcpy(&meta->lvalue.hdr, &hdr->left, sizeof(hdr->left));
777 memcpy(&meta->rvalue.hdr, &hdr->right, sizeof(hdr->right));
778
779 if (!meta_is_supported(&meta->lvalue) ||
780 !meta_is_supported(&meta->rvalue)) {
781 err = -EOPNOTSUPP;
782 goto errout;
783 }
784
785 if (meta_change_data(&meta->lvalue, tb[TCA_EM_META_LVALUE]) < 0 ||
786 meta_change_data(&meta->rvalue, tb[TCA_EM_META_RVALUE]) < 0)
787 goto errout;
788
789 m->datalen = sizeof(*meta);
790 m->data = (unsigned long) meta;
791
792 err = 0;
793 errout:
794 if (err && meta)
795 meta_delete(meta);
796 return err;
797 }
798
799 static void em_meta_destroy(struct tcf_proto *tp, struct tcf_ematch *m)
800 {
801 if (m)
802 meta_delete((struct meta_match *) m->data);
803 }
804
805 static int em_meta_dump(struct sk_buff *skb, struct tcf_ematch *em)
806 {
807 struct meta_match *meta = (struct meta_match *) em->data;
808 struct tcf_meta_hdr hdr;
809 struct meta_type_ops *ops;
810
811 memset(&hdr, 0, sizeof(hdr));
812 memcpy(&hdr.left, &meta->lvalue.hdr, sizeof(hdr.left));
813 memcpy(&hdr.right, &meta->rvalue.hdr, sizeof(hdr.right));
814
815 NLA_PUT(skb, TCA_EM_META_HDR, sizeof(hdr), &hdr);
816
817 ops = meta_type_ops(&meta->lvalue);
818 if (ops->dump(skb, &meta->lvalue, TCA_EM_META_LVALUE) < 0 ||
819 ops->dump(skb, &meta->rvalue, TCA_EM_META_RVALUE) < 0)
820 goto nla_put_failure;
821
822 return 0;
823
824 nla_put_failure:
825 return -1;
826 }
827
828 static struct tcf_ematch_ops em_meta_ops = {
829 .kind = TCF_EM_META,
830 .change = em_meta_change,
831 .match = em_meta_match,
832 .destroy = em_meta_destroy,
833 .dump = em_meta_dump,
834 .owner = THIS_MODULE,
835 .link = LIST_HEAD_INIT(em_meta_ops.link)
836 };
837
838 static int __init init_em_meta(void)
839 {
840 return tcf_em_register(&em_meta_ops);
841 }
842
843 static void __exit exit_em_meta(void)
844 {
845 tcf_em_unregister(&em_meta_ops);
846 }
847
848 MODULE_LICENSE("GPL");
849
850 module_init(init_em_meta);
851 module_exit(exit_em_meta);
852
853 MODULE_ALIAS_TCF_EMATCH(TCF_EM_META);