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efivars: Add Documentation
[linux-2.6/next.git] / net / sched / em_meta.c
blob34da5e29ea1a8026388805cfba52e782ba01c9ec
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/slab.h>
62 #include <linux/module.h>
63 #include <linux/types.h>
64 #include <linux/kernel.h>
65 #include <linux/sched.h>
66 #include <linux/string.h>
67 #include <linux/skbuff.h>
68 #include <linux/random.h>
69 #include <linux/if_vlan.h>
70 #include <linux/tc_ematch/tc_em_meta.h>
71 #include <net/dst.h>
72 #include <net/route.h>
73 #include <net/pkt_cls.h>
74 #include <net/sock.h>
75
76 struct meta_obj
77 {
78 unsigned long value;
79 unsigned int len;
80 };
81
82 struct meta_value
83 {
84 struct tcf_meta_val hdr;
85 unsigned long val;
86 unsigned int len;
87 };
88
89 struct meta_match
90 {
91 struct meta_value lvalue;
92 struct meta_value rvalue;
93 };
94
95 static inline int meta_id(struct meta_value *v)
96 {
97 return TCF_META_ID(v->hdr.kind);
98 }
99
100 static inline int meta_type(struct meta_value *v)
101 {
102 return TCF_META_TYPE(v->hdr.kind);
103 }
104
105 #define META_COLLECTOR(FUNC) static void meta_##FUNC(struct sk_buff *skb, \
106 struct tcf_pkt_info *info, struct meta_value *v, \
107 struct meta_obj *dst, int *err)
108
109 /**************************************************************************
110 * System status & misc
111 **************************************************************************/
112
113 META_COLLECTOR(int_random)
114 {
115 get_random_bytes(&dst->value, sizeof(dst->value));
116 }
117
118 static inline unsigned long fixed_loadavg(int load)
119 {
120 int rnd_load = load + (FIXED_1/200);
121 int rnd_frac = ((rnd_load & (FIXED_1-1)) * 100) >> FSHIFT;
122
123 return ((rnd_load >> FSHIFT) * 100) + rnd_frac;
124 }
125
126 META_COLLECTOR(int_loadavg_0)
127 {
128 dst->value = fixed_loadavg(avenrun[0]);
129 }
130
131 META_COLLECTOR(int_loadavg_1)
132 {
133 dst->value = fixed_loadavg(avenrun[1]);
134 }
135
136 META_COLLECTOR(int_loadavg_2)
137 {
138 dst->value = fixed_loadavg(avenrun[2]);
139 }
140
141 /**************************************************************************
142 * Device names & indices
143 **************************************************************************/
144
145 static inline int int_dev(struct net_device *dev, struct meta_obj *dst)
146 {
147 if (unlikely(dev == NULL))
148 return -1;
149
150 dst->value = dev->ifindex;
151 return 0;
152 }
153
154 static inline int var_dev(struct net_device *dev, struct meta_obj *dst)
155 {
156 if (unlikely(dev == NULL))
157 return -1;
158
159 dst->value = (unsigned long) dev->name;
160 dst->len = strlen(dev->name);
161 return 0;
162 }
163
164 META_COLLECTOR(int_dev)
165 {
166 *err = int_dev(skb->dev, dst);
167 }
168
169 META_COLLECTOR(var_dev)
170 {
171 *err = var_dev(skb->dev, dst);
172 }
173
174 /**************************************************************************
175 * vlan tag
176 **************************************************************************/
177
178 META_COLLECTOR(int_vlan_tag)
179 {
180 unsigned short tag;
181
182 tag = vlan_tx_tag_get(skb);
183 if (!tag && __vlan_get_tag(skb, &tag))
184 *err = -1;
185 else
186 dst->value = tag;
187 }
188
189
190
191 /**************************************************************************
192 * skb attributes
193 **************************************************************************/
194
195 META_COLLECTOR(int_priority)
196 {
197 dst->value = skb->priority;
198 }
199
200 META_COLLECTOR(int_protocol)
201 {
202 /* Let userspace take care of the byte ordering */
203 dst->value = skb->protocol;
204 }
205
206 META_COLLECTOR(int_pkttype)
207 {
208 dst->value = skb->pkt_type;
209 }
210
211 META_COLLECTOR(int_pktlen)
212 {
213 dst->value = skb->len;
214 }
215
216 META_COLLECTOR(int_datalen)
217 {
218 dst->value = skb->data_len;
219 }
220
221 META_COLLECTOR(int_maclen)
222 {
223 dst->value = skb->mac_len;
224 }
225
226 META_COLLECTOR(int_rxhash)
227 {
228 dst->value = skb_get_rxhash(skb);
229 }
230
231 /**************************************************************************
232 * Netfilter
233 **************************************************************************/
234
235 META_COLLECTOR(int_mark)
236 {
237 dst->value = skb->mark;
238 }
239
240 /**************************************************************************
241 * Traffic Control
242 **************************************************************************/
243
244 META_COLLECTOR(int_tcindex)
245 {
246 dst->value = skb->tc_index;
247 }
248
249 /**************************************************************************
250 * Routing
251 **************************************************************************/
252
253 META_COLLECTOR(int_rtclassid)
254 {
255 if (unlikely(skb_dst(skb) == NULL))
256 *err = -1;
257 else
258 #ifdef CONFIG_NET_CLS_ROUTE
259 dst->value = skb_dst(skb)->tclassid;
260 #else
261 dst->value = 0;
262 #endif
263 }
264
265 META_COLLECTOR(int_rtiif)
266 {
267 if (unlikely(skb_rtable(skb) == NULL))
268 *err = -1;
269 else
270 dst->value = skb_rtable(skb)->fl.iif;
271 }
272
273 /**************************************************************************
274 * Socket Attributes
275 **************************************************************************/
276
277 #define SKIP_NONLOCAL(skb) \
278 if (unlikely(skb->sk == NULL)) { \
279 *err = -1; \
280 return; \
281 }
282
283 META_COLLECTOR(int_sk_family)
284 {
285 SKIP_NONLOCAL(skb);
286 dst->value = skb->sk->sk_family;
287 }
288
289 META_COLLECTOR(int_sk_state)
290 {
291 SKIP_NONLOCAL(skb);
292 dst->value = skb->sk->sk_state;
293 }
294
295 META_COLLECTOR(int_sk_reuse)
296 {
297 SKIP_NONLOCAL(skb);
298 dst->value = skb->sk->sk_reuse;
299 }
300
301 META_COLLECTOR(int_sk_bound_if)
302 {
303 SKIP_NONLOCAL(skb);
304 /* No error if bound_dev_if is 0, legal userspace check */
305 dst->value = skb->sk->sk_bound_dev_if;
306 }
307
308 META_COLLECTOR(var_sk_bound_if)
309 {
310 SKIP_NONLOCAL(skb);
311
312 if (skb->sk->sk_bound_dev_if == 0) {
313 dst->value = (unsigned long) "any";
314 dst->len = 3;
315 } else {
316 struct net_device *dev;
317
318 rcu_read_lock();
319 dev = dev_get_by_index_rcu(sock_net(skb->sk),
320 skb->sk->sk_bound_dev_if);
321 *err = var_dev(dev, dst);
322 rcu_read_unlock();
323 }
324 }
325
326 META_COLLECTOR(int_sk_refcnt)
327 {
328 SKIP_NONLOCAL(skb);
329 dst->value = atomic_read(&skb->sk->sk_refcnt);
330 }
331
332 META_COLLECTOR(int_sk_rcvbuf)
333 {
334 SKIP_NONLOCAL(skb);
335 dst->value = skb->sk->sk_rcvbuf;
336 }
337
338 META_COLLECTOR(int_sk_shutdown)
339 {
340 SKIP_NONLOCAL(skb);
341 dst->value = skb->sk->sk_shutdown;
342 }
343
344 META_COLLECTOR(int_sk_proto)
345 {
346 SKIP_NONLOCAL(skb);
347 dst->value = skb->sk->sk_protocol;
348 }
349
350 META_COLLECTOR(int_sk_type)
351 {
352 SKIP_NONLOCAL(skb);
353 dst->value = skb->sk->sk_type;
354 }
355
356 META_COLLECTOR(int_sk_rmem_alloc)
357 {
358 SKIP_NONLOCAL(skb);
359 dst->value = sk_rmem_alloc_get(skb->sk);
360 }
361
362 META_COLLECTOR(int_sk_wmem_alloc)
363 {
364 SKIP_NONLOCAL(skb);
365 dst->value = sk_wmem_alloc_get(skb->sk);
366 }
367
368 META_COLLECTOR(int_sk_omem_alloc)
369 {
370 SKIP_NONLOCAL(skb);
371 dst->value = atomic_read(&skb->sk->sk_omem_alloc);
372 }
373
374 META_COLLECTOR(int_sk_rcv_qlen)
375 {
376 SKIP_NONLOCAL(skb);
377 dst->value = skb->sk->sk_receive_queue.qlen;
378 }
379
380 META_COLLECTOR(int_sk_snd_qlen)
381 {
382 SKIP_NONLOCAL(skb);
383 dst->value = skb->sk->sk_write_queue.qlen;
384 }
385
386 META_COLLECTOR(int_sk_wmem_queued)
387 {
388 SKIP_NONLOCAL(skb);
389 dst->value = skb->sk->sk_wmem_queued;
390 }
391
392 META_COLLECTOR(int_sk_fwd_alloc)
393 {
394 SKIP_NONLOCAL(skb);
395 dst->value = skb->sk->sk_forward_alloc;
396 }
397
398 META_COLLECTOR(int_sk_sndbuf)
399 {
400 SKIP_NONLOCAL(skb);
401 dst->value = skb->sk->sk_sndbuf;
402 }
403
404 META_COLLECTOR(int_sk_alloc)
405 {
406 SKIP_NONLOCAL(skb);
407 dst->value = skb->sk->sk_allocation;
408 }
409
410 META_COLLECTOR(int_sk_route_caps)
411 {
412 SKIP_NONLOCAL(skb);
413 dst->value = skb->sk->sk_route_caps;
414 }
415
416 META_COLLECTOR(int_sk_hash)
417 {
418 SKIP_NONLOCAL(skb);
419 dst->value = skb->sk->sk_hash;
420 }
421
422 META_COLLECTOR(int_sk_lingertime)
423 {
424 SKIP_NONLOCAL(skb);
425 dst->value = skb->sk->sk_lingertime / HZ;
426 }
427
428 META_COLLECTOR(int_sk_err_qlen)
429 {
430 SKIP_NONLOCAL(skb);
431 dst->value = skb->sk->sk_error_queue.qlen;
432 }
433
434 META_COLLECTOR(int_sk_ack_bl)
435 {
436 SKIP_NONLOCAL(skb);
437 dst->value = skb->sk->sk_ack_backlog;
438 }
439
440 META_COLLECTOR(int_sk_max_ack_bl)
441 {
442 SKIP_NONLOCAL(skb);
443 dst->value = skb->sk->sk_max_ack_backlog;
444 }
445
446 META_COLLECTOR(int_sk_prio)
447 {
448 SKIP_NONLOCAL(skb);
449 dst->value = skb->sk->sk_priority;
450 }
451
452 META_COLLECTOR(int_sk_rcvlowat)
453 {
454 SKIP_NONLOCAL(skb);
455 dst->value = skb->sk->sk_rcvlowat;
456 }
457
458 META_COLLECTOR(int_sk_rcvtimeo)
459 {
460 SKIP_NONLOCAL(skb);
461 dst->value = skb->sk->sk_rcvtimeo / HZ;
462 }
463
464 META_COLLECTOR(int_sk_sndtimeo)
465 {
466 SKIP_NONLOCAL(skb);
467 dst->value = skb->sk->sk_sndtimeo / HZ;
468 }
469
470 META_COLLECTOR(int_sk_sendmsg_off)
471 {
472 SKIP_NONLOCAL(skb);
473 dst->value = skb->sk->sk_sndmsg_off;
474 }
475
476 META_COLLECTOR(int_sk_write_pend)
477 {
478 SKIP_NONLOCAL(skb);
479 dst->value = skb->sk->sk_write_pending;
480 }
481
482 /**************************************************************************
483 * Meta value collectors assignment table
484 **************************************************************************/
485
486 struct meta_ops
487 {
488 void (*get)(struct sk_buff *, struct tcf_pkt_info *,
489 struct meta_value *, struct meta_obj *, int *);
490 };
491
492 #define META_ID(name) TCF_META_ID_##name
493 #define META_FUNC(name) { .get = meta_##name }
494
495 /* Meta value operations table listing all meta value collectors and
496 * assigns them to a type and meta id. */
497 static struct meta_ops __meta_ops[TCF_META_TYPE_MAX+1][TCF_META_ID_MAX+1] = {
498 [TCF_META_TYPE_VAR] = {
499 [META_ID(DEV)] = META_FUNC(var_dev),
500 [META_ID(SK_BOUND_IF)] = META_FUNC(var_sk_bound_if),
501 },
502 [TCF_META_TYPE_INT] = {
503 [META_ID(RANDOM)] = META_FUNC(int_random),
504 [META_ID(LOADAVG_0)] = META_FUNC(int_loadavg_0),
505 [META_ID(LOADAVG_1)] = META_FUNC(int_loadavg_1),
506 [META_ID(LOADAVG_2)] = META_FUNC(int_loadavg_2),
507 [META_ID(DEV)] = META_FUNC(int_dev),
508 [META_ID(PRIORITY)] = META_FUNC(int_priority),
509 [META_ID(PROTOCOL)] = META_FUNC(int_protocol),
510 [META_ID(PKTTYPE)] = META_FUNC(int_pkttype),
511 [META_ID(PKTLEN)] = META_FUNC(int_pktlen),
512 [META_ID(DATALEN)] = META_FUNC(int_datalen),
513 [META_ID(MACLEN)] = META_FUNC(int_maclen),
514 [META_ID(NFMARK)] = META_FUNC(int_mark),
515 [META_ID(TCINDEX)] = META_FUNC(int_tcindex),
516 [META_ID(RTCLASSID)] = META_FUNC(int_rtclassid),
517 [META_ID(RTIIF)] = META_FUNC(int_rtiif),
518 [META_ID(SK_FAMILY)] = META_FUNC(int_sk_family),
519 [META_ID(SK_STATE)] = META_FUNC(int_sk_state),
520 [META_ID(SK_REUSE)] = META_FUNC(int_sk_reuse),
521 [META_ID(SK_BOUND_IF)] = META_FUNC(int_sk_bound_if),
522 [META_ID(SK_REFCNT)] = META_FUNC(int_sk_refcnt),
523 [META_ID(SK_RCVBUF)] = META_FUNC(int_sk_rcvbuf),
524 [META_ID(SK_SNDBUF)] = META_FUNC(int_sk_sndbuf),
525 [META_ID(SK_SHUTDOWN)] = META_FUNC(int_sk_shutdown),
526 [META_ID(SK_PROTO)] = META_FUNC(int_sk_proto),
527 [META_ID(SK_TYPE)] = META_FUNC(int_sk_type),
528 [META_ID(SK_RMEM_ALLOC)] = META_FUNC(int_sk_rmem_alloc),
529 [META_ID(SK_WMEM_ALLOC)] = META_FUNC(int_sk_wmem_alloc),
530 [META_ID(SK_OMEM_ALLOC)] = META_FUNC(int_sk_omem_alloc),
531 [META_ID(SK_WMEM_QUEUED)] = META_FUNC(int_sk_wmem_queued),
532 [META_ID(SK_RCV_QLEN)] = META_FUNC(int_sk_rcv_qlen),
533 [META_ID(SK_SND_QLEN)] = META_FUNC(int_sk_snd_qlen),
534 [META_ID(SK_ERR_QLEN)] = META_FUNC(int_sk_err_qlen),
535 [META_ID(SK_FORWARD_ALLOCS)] = META_FUNC(int_sk_fwd_alloc),
536 [META_ID(SK_ALLOCS)] = META_FUNC(int_sk_alloc),
537 [META_ID(SK_ROUTE_CAPS)] = META_FUNC(int_sk_route_caps),
538 [META_ID(SK_HASH)] = META_FUNC(int_sk_hash),
539 [META_ID(SK_LINGERTIME)] = META_FUNC(int_sk_lingertime),
540 [META_ID(SK_ACK_BACKLOG)] = META_FUNC(int_sk_ack_bl),
541 [META_ID(SK_MAX_ACK_BACKLOG)] = META_FUNC(int_sk_max_ack_bl),
542 [META_ID(SK_PRIO)] = META_FUNC(int_sk_prio),
543 [META_ID(SK_RCVLOWAT)] = META_FUNC(int_sk_rcvlowat),
544 [META_ID(SK_RCVTIMEO)] = META_FUNC(int_sk_rcvtimeo),
545 [META_ID(SK_SNDTIMEO)] = META_FUNC(int_sk_sndtimeo),
546 [META_ID(SK_SENDMSG_OFF)] = META_FUNC(int_sk_sendmsg_off),
547 [META_ID(SK_WRITE_PENDING)] = META_FUNC(int_sk_write_pend),
548 [META_ID(VLAN_TAG)] = META_FUNC(int_vlan_tag),
549 [META_ID(RXHASH)] = META_FUNC(int_rxhash),
550 }
551 };
552
553 static inline struct meta_ops * meta_ops(struct meta_value *val)
554 {
555 return &__meta_ops[meta_type(val)][meta_id(val)];
556 }
557
558 /**************************************************************************
559 * Type specific operations for TCF_META_TYPE_VAR
560 **************************************************************************/
561
562 static int meta_var_compare(struct meta_obj *a, struct meta_obj *b)
563 {
564 int r = a->len - b->len;
565
566 if (r == 0)
567 r = memcmp((void *) a->value, (void *) b->value, a->len);
568
569 return r;
570 }
571
572 static int meta_var_change(struct meta_value *dst, struct nlattr *nla)
573 {
574 int len = nla_len(nla);
575
576 dst->val = (unsigned long)kmemdup(nla_data(nla), len, GFP_KERNEL);
577 if (dst->val == 0UL)
578 return -ENOMEM;
579 dst->len = len;
580 return 0;
581 }
582
583 static void meta_var_destroy(struct meta_value *v)
584 {
585 kfree((void *) v->val);
586 }
587
588 static void meta_var_apply_extras(struct meta_value *v,
589 struct meta_obj *dst)
590 {
591 int shift = v->hdr.shift;
592
593 if (shift && shift < dst->len)
594 dst->len -= shift;
595 }
596
597 static int meta_var_dump(struct sk_buff *skb, struct meta_value *v, int tlv)
598 {
599 if (v->val && v->len)
600 NLA_PUT(skb, tlv, v->len, (void *) v->val);
601 return 0;
602
603 nla_put_failure:
604 return -1;
605 }
606
607 /**************************************************************************
608 * Type specific operations for TCF_META_TYPE_INT
609 **************************************************************************/
610
611 static int meta_int_compare(struct meta_obj *a, struct meta_obj *b)
612 {
613 /* Let gcc optimize it, the unlikely is not really based on
614 * some numbers but jump free code for mismatches seems
615 * more logical. */
616 if (unlikely(a->value == b->value))
617 return 0;
618 else if (a->value < b->value)
619 return -1;
620 else
621 return 1;
622 }
623
624 static int meta_int_change(struct meta_value *dst, struct nlattr *nla)
625 {
626 if (nla_len(nla) >= sizeof(unsigned long)) {
627 dst->val = *(unsigned long *) nla_data(nla);
628 dst->len = sizeof(unsigned long);
629 } else if (nla_len(nla) == sizeof(u32)) {
630 dst->val = nla_get_u32(nla);
631 dst->len = sizeof(u32);
632 } else
633 return -EINVAL;
634
635 return 0;
636 }
637
638 static void meta_int_apply_extras(struct meta_value *v,
639 struct meta_obj *dst)
640 {
641 if (v->hdr.shift)
642 dst->value >>= v->hdr.shift;
643
644 if (v->val)
645 dst->value &= v->val;
646 }
647
648 static int meta_int_dump(struct sk_buff *skb, struct meta_value *v, int tlv)
649 {
650 if (v->len == sizeof(unsigned long))
651 NLA_PUT(skb, tlv, sizeof(unsigned long), &v->val);
652 else if (v->len == sizeof(u32)) {
653 NLA_PUT_U32(skb, tlv, v->val);
654 }
655
656 return 0;
657
658 nla_put_failure:
659 return -1;
660 }
661
662 /**************************************************************************
663 * Type specific operations table
664 **************************************************************************/
665
666 struct meta_type_ops
667 {
668 void (*destroy)(struct meta_value *);
669 int (*compare)(struct meta_obj *, struct meta_obj *);
670 int (*change)(struct meta_value *, struct nlattr *);
671 void (*apply_extras)(struct meta_value *, struct meta_obj *);
672 int (*dump)(struct sk_buff *, struct meta_value *, int);
673 };
674
675 static struct meta_type_ops __meta_type_ops[TCF_META_TYPE_MAX+1] = {
676 [TCF_META_TYPE_VAR] = {
677 .destroy = meta_var_destroy,
678 .compare = meta_var_compare,
679 .change = meta_var_change,
680 .apply_extras = meta_var_apply_extras,
681 .dump = meta_var_dump
682 },
683 [TCF_META_TYPE_INT] = {
684 .compare = meta_int_compare,
685 .change = meta_int_change,
686 .apply_extras = meta_int_apply_extras,
687 .dump = meta_int_dump
688 }
689 };
690
691 static inline struct meta_type_ops * meta_type_ops(struct meta_value *v)
692 {
693 return &__meta_type_ops[meta_type(v)];
694 }
695
696 /**************************************************************************
697 * Core
698 **************************************************************************/
699
700 static int meta_get(struct sk_buff *skb, struct tcf_pkt_info *info,
701 struct meta_value *v, struct meta_obj *dst)
702 {
703 int err = 0;
704
705 if (meta_id(v) == TCF_META_ID_VALUE) {
706 dst->value = v->val;
707 dst->len = v->len;
708 return 0;
709 }
710
711 meta_ops(v)->get(skb, info, v, dst, &err);
712 if (err < 0)
713 return err;
714
715 if (meta_type_ops(v)->apply_extras)
716 meta_type_ops(v)->apply_extras(v, dst);
717
718 return 0;
719 }
720
721 static int em_meta_match(struct sk_buff *skb, struct tcf_ematch *m,
722 struct tcf_pkt_info *info)
723 {
724 int r;
725 struct meta_match *meta = (struct meta_match *) m->data;
726 struct meta_obj l_value, r_value;
727
728 if (meta_get(skb, info, &meta->lvalue, &l_value) < 0 ||
729 meta_get(skb, info, &meta->rvalue, &r_value) < 0)
730 return 0;
731
732 r = meta_type_ops(&meta->lvalue)->compare(&l_value, &r_value);
733
734 switch (meta->lvalue.hdr.op) {
735 case TCF_EM_OPND_EQ:
736 return !r;
737 case TCF_EM_OPND_LT:
738 return r < 0;
739 case TCF_EM_OPND_GT:
740 return r > 0;
741 }
742
743 return 0;
744 }
745
746 static void meta_delete(struct meta_match *meta)
747 {
748 if (meta) {
749 struct meta_type_ops *ops = meta_type_ops(&meta->lvalue);
750
751 if (ops && ops->destroy) {
752 ops->destroy(&meta->lvalue);
753 ops->destroy(&meta->rvalue);
754 }
755 }
756
757 kfree(meta);
758 }
759
760 static inline int meta_change_data(struct meta_value *dst, struct nlattr *nla)
761 {
762 if (nla) {
763 if (nla_len(nla) == 0)
764 return -EINVAL;
765
766 return meta_type_ops(dst)->change(dst, nla);
767 }
768
769 return 0;
770 }
771
772 static inline int meta_is_supported(struct meta_value *val)
773 {
774 return (!meta_id(val) || meta_ops(val)->get);
775 }
776
777 static const struct nla_policy meta_policy[TCA_EM_META_MAX + 1] = {
778 [TCA_EM_META_HDR] = { .len = sizeof(struct tcf_meta_hdr) },
779 };
780
781 static int em_meta_change(struct tcf_proto *tp, void *data, int len,
782 struct tcf_ematch *m)
783 {
784 int err;
785 struct nlattr *tb[TCA_EM_META_MAX + 1];
786 struct tcf_meta_hdr *hdr;
787 struct meta_match *meta = NULL;
788
789 err = nla_parse(tb, TCA_EM_META_MAX, data, len, meta_policy);
790 if (err < 0)
791 goto errout;
792
793 err = -EINVAL;
794 if (tb[TCA_EM_META_HDR] == NULL)
795 goto errout;
796 hdr = nla_data(tb[TCA_EM_META_HDR]);
797
798 if (TCF_META_TYPE(hdr->left.kind) != TCF_META_TYPE(hdr->right.kind) ||
799 TCF_META_TYPE(hdr->left.kind) > TCF_META_TYPE_MAX ||
800 TCF_META_ID(hdr->left.kind) > TCF_META_ID_MAX ||
801 TCF_META_ID(hdr->right.kind) > TCF_META_ID_MAX)
802 goto errout;
803
804 meta = kzalloc(sizeof(*meta), GFP_KERNEL);
805 if (meta == NULL)
806 goto errout;
807
808 memcpy(&meta->lvalue.hdr, &hdr->left, sizeof(hdr->left));
809 memcpy(&meta->rvalue.hdr, &hdr->right, sizeof(hdr->right));
810
811 if (!meta_is_supported(&meta->lvalue) ||
812 !meta_is_supported(&meta->rvalue)) {
813 err = -EOPNOTSUPP;
814 goto errout;
815 }
816
817 if (meta_change_data(&meta->lvalue, tb[TCA_EM_META_LVALUE]) < 0 ||
818 meta_change_data(&meta->rvalue, tb[TCA_EM_META_RVALUE]) < 0)
819 goto errout;
820
821 m->datalen = sizeof(*meta);
822 m->data = (unsigned long) meta;
823
824 err = 0;
825 errout:
826 if (err && meta)
827 meta_delete(meta);
828 return err;
829 }
830
831 static void em_meta_destroy(struct tcf_proto *tp, struct tcf_ematch *m)
832 {
833 if (m)
834 meta_delete((struct meta_match *) m->data);
835 }
836
837 static int em_meta_dump(struct sk_buff *skb, struct tcf_ematch *em)
838 {
839 struct meta_match *meta = (struct meta_match *) em->data;
840 struct tcf_meta_hdr hdr;
841 struct meta_type_ops *ops;
842
843 memset(&hdr, 0, sizeof(hdr));
844 memcpy(&hdr.left, &meta->lvalue.hdr, sizeof(hdr.left));
845 memcpy(&hdr.right, &meta->rvalue.hdr, sizeof(hdr.right));
846
847 NLA_PUT(skb, TCA_EM_META_HDR, sizeof(hdr), &hdr);
848
849 ops = meta_type_ops(&meta->lvalue);
850 if (ops->dump(skb, &meta->lvalue, TCA_EM_META_LVALUE) < 0 ||
851 ops->dump(skb, &meta->rvalue, TCA_EM_META_RVALUE) < 0)
852 goto nla_put_failure;
853
854 return 0;
855
856 nla_put_failure:
857 return -1;
858 }
859
860 static struct tcf_ematch_ops em_meta_ops = {
861 .kind = TCF_EM_META,
862 .change = em_meta_change,
863 .match = em_meta_match,
864 .destroy = em_meta_destroy,
865 .dump = em_meta_dump,
866 .owner = THIS_MODULE,
867 .link = LIST_HEAD_INIT(em_meta_ops.link)
868 };
869
870 static int __init init_em_meta(void)
871 {
872 return tcf_em_register(&em_meta_ops);
873 }
874
875 static void __exit exit_em_meta(void)
876 {
877 tcf_em_unregister(&em_meta_ops);
878 }
879
880 MODULE_LICENSE("GPL");
881
882 module_init(init_em_meta);
883 module_exit(exit_em_meta);
884
885 MODULE_ALIAS_TCF_EMATCH(TCF_EM_META);
linux-next