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[EMATCH]: Kill TCF_META_ID_TCCLASSID reference from meta ematch as well.
[linux-2.6/kvm.git] / net / sched / em_meta.c
blobfeefcbfd03d01a81db0f49f3a4cedf928780cfa0
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: INDEV | | id: VALUE |
31 * | data: | | data: 3 |
32 * +-----------+ +-----------+
33 * | |
34 * ---> meta_ops[INT][INDEV](...) |
35 * | |
36 * ----------- |
37 * V V
38 * +-----------+ +-----------+
39 * | type: INT | | type: INT |
40 * obj | id: INDEV | | 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 subsytem is enabled in the kernel.
59 */
60
61 #include <linux/config.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/tc_ematch/tc_em_meta.h>
70 #include <net/dst.h>
71 #include <net/route.h>
72 #include <net/pkt_cls.h>
73 #include <net/sock.h>
74
75 struct meta_obj
76 {
77 unsigned long value;
78 unsigned int len;
79 };
80
81 struct meta_value
82 {
83 struct tcf_meta_val hdr;
84 unsigned long val;
85 unsigned int len;
86 };
87
88 struct meta_match
89 {
90 struct meta_value lvalue;
91 struct meta_value rvalue;
92 };
93
94 static inline int meta_id(struct meta_value *v)
95 {
96 return TCF_META_ID(v->hdr.kind);
97 }
98
99 static inline int meta_type(struct meta_value *v)
100 {
101 return TCF_META_TYPE(v->hdr.kind);
102 }
103
104 #define META_COLLECTOR(FUNC) static void meta_##FUNC(struct sk_buff *skb, \
105 struct tcf_pkt_info *info, struct meta_value *v, \
106 struct meta_obj *dst, int *err)
107
108 /**************************************************************************
109 * System status & misc
110 **************************************************************************/
111
112 META_COLLECTOR(int_random)
113 {
114 get_random_bytes(&dst->value, sizeof(dst->value));
115 }
116
117 static inline unsigned long fixed_loadavg(int load)
118 {
119 int rnd_load = load + (FIXED_1/200);
120 int rnd_frac = ((rnd_load & (FIXED_1-1)) * 100) >> FSHIFT;
121
122 return ((rnd_load >> FSHIFT) * 100) + rnd_frac;
123 }
124
125 META_COLLECTOR(int_loadavg_0)
126 {
127 dst->value = fixed_loadavg(avenrun[0]);
128 }
129
130 META_COLLECTOR(int_loadavg_1)
131 {
132 dst->value = fixed_loadavg(avenrun[1]);
133 }
134
135 META_COLLECTOR(int_loadavg_2)
136 {
137 dst->value = fixed_loadavg(avenrun[2]);
138 }
139
140 /**************************************************************************
141 * Device names & indices
142 **************************************************************************/
143
144 static inline int int_dev(struct net_device *dev, struct meta_obj *dst)
145 {
146 if (unlikely(dev == NULL))
147 return -1;
148
149 dst->value = dev->ifindex;
150 return 0;
151 }
152
153 static inline int var_dev(struct net_device *dev, struct meta_obj *dst)
154 {
155 if (unlikely(dev == NULL))
156 return -1;
157
158 dst->value = (unsigned long) dev->name;
159 dst->len = strlen(dev->name);
160 return 0;
161 }
162
163 META_COLLECTOR(int_dev)
164 {
165 *err = int_dev(skb->dev, dst);
166 }
167
168 META_COLLECTOR(var_dev)
169 {
170 *err = var_dev(skb->dev, dst);
171 }
172
173 META_COLLECTOR(int_indev)
174 {
175 *err = int_dev(skb->input_dev, dst);
176 }
177
178 META_COLLECTOR(var_indev)
179 {
180 *err = var_dev(skb->input_dev, dst);
181 }
182
183 META_COLLECTOR(int_realdev)
184 {
185 *err = int_dev(skb->real_dev, dst);
186 }
187
188 META_COLLECTOR(var_realdev)
189 {
190 *err = var_dev(skb->real_dev, dst);
191 }
192
193 /**************************************************************************
194 * skb attributes
195 **************************************************************************/
196
197 META_COLLECTOR(int_priority)
198 {
199 dst->value = skb->priority;
200 }
201
202 META_COLLECTOR(int_protocol)
203 {
204 /* Let userspace take care of the byte ordering */
205 dst->value = skb->protocol;
206 }
207
208 META_COLLECTOR(int_pkttype)
209 {
210 dst->value = skb->pkt_type;
211 }
212
213 META_COLLECTOR(int_pktlen)
214 {
215 dst->value = skb->len;
216 }
217
218 META_COLLECTOR(int_datalen)
219 {
220 dst->value = skb->data_len;
221 }
222
223 META_COLLECTOR(int_maclen)
224 {
225 dst->value = skb->mac_len;
226 }
227
228 /**************************************************************************
229 * Netfilter
230 **************************************************************************/
231
232 #ifdef CONFIG_NETFILTER
233 META_COLLECTOR(int_nfmark)
234 {
235 dst->value = skb->nfmark;
236 }
237 #endif
238
239 /**************************************************************************
240 * Traffic Control
241 **************************************************************************/
242
243 META_COLLECTOR(int_tcindex)
244 {
245 dst->value = skb->tc_index;
246 }
247
248 #ifdef CONFIG_NET_CLS_ACT
249 META_COLLECTOR(int_tcverd)
250 {
251 dst->value = skb->tc_verd;
252 }
253 #endif
254
255 /**************************************************************************
256 * Routing
257 **************************************************************************/
258
259 #ifdef CONFIG_NET_CLS_ROUTE
260 META_COLLECTOR(int_rtclassid)
261 {
262 if (unlikely(skb->dst == NULL))
263 *err = -1;
264 else
265 dst->value = skb->dst->tclassid;
266 }
267 #endif
268
269 META_COLLECTOR(int_rtiif)
270 {
271 if (unlikely(skb->dst == NULL))
272 *err = -1;
273 else
274 dst->value = ((struct rtable*) skb->dst)->fl.iif;
275 }
276
277 /**************************************************************************
278 * Socket Attributes
279 **************************************************************************/
280
281 #define SKIP_NONLOCAL(skb) \
282 if (unlikely(skb->sk == NULL)) { \
283 *err = -1; \
284 return; \
285 }
286
287 META_COLLECTOR(int_sk_family)
288 {
289 SKIP_NONLOCAL(skb);
290 dst->value = skb->sk->sk_family;
291 }
292
293 META_COLLECTOR(int_sk_state)
294 {
295 SKIP_NONLOCAL(skb);
296 dst->value = skb->sk->sk_state;
297 }
298
299 META_COLLECTOR(int_sk_reuse)
300 {
301 SKIP_NONLOCAL(skb);
302 dst->value = skb->sk->sk_reuse;
303 }
304
305 META_COLLECTOR(int_sk_bound_if)
306 {
307 SKIP_NONLOCAL(skb);
308 /* No error if bound_dev_if is 0, legal userspace check */
309 dst->value = skb->sk->sk_bound_dev_if;
310 }
311
312 META_COLLECTOR(var_sk_bound_if)
313 {
314 SKIP_NONLOCAL(skb);
315
316 if (skb->sk->sk_bound_dev_if == 0) {
317 dst->value = (unsigned long) "any";
318 dst->len = 3;
319 } else {
320 struct net_device *dev;
321
322 dev = dev_get_by_index(skb->sk->sk_bound_dev_if);
323 *err = var_dev(dev, dst);
324 if (dev)
325 dev_put(dev);
326 }
327 }
328
329 META_COLLECTOR(int_sk_refcnt)
330 {
331 SKIP_NONLOCAL(skb);
332 dst->value = atomic_read(&skb->sk->sk_refcnt);
333 }
334
335 META_COLLECTOR(int_sk_rcvbuf)
336 {
337 SKIP_NONLOCAL(skb);
338 dst->value = skb->sk->sk_rcvbuf;
339 }
340
341 META_COLLECTOR(int_sk_shutdown)
342 {
343 SKIP_NONLOCAL(skb);
344 dst->value = skb->sk->sk_shutdown;
345 }
346
347 META_COLLECTOR(int_sk_proto)
348 {
349 SKIP_NONLOCAL(skb);
350 dst->value = skb->sk->sk_protocol;
351 }
352
353 META_COLLECTOR(int_sk_type)
354 {
355 SKIP_NONLOCAL(skb);
356 dst->value = skb->sk->sk_type;
357 }
358
359 META_COLLECTOR(int_sk_rmem_alloc)
360 {
361 SKIP_NONLOCAL(skb);
362 dst->value = atomic_read(&skb->sk->sk_rmem_alloc);
363 }
364
365 META_COLLECTOR(int_sk_wmem_alloc)
366 {
367 SKIP_NONLOCAL(skb);
368 dst->value = atomic_read(&skb->sk->sk_wmem_alloc);
369 }
370
371 META_COLLECTOR(int_sk_omem_alloc)
372 {
373 SKIP_NONLOCAL(skb);
374 dst->value = atomic_read(&skb->sk->sk_omem_alloc);
375 }
376
377 META_COLLECTOR(int_sk_rcv_qlen)
378 {
379 SKIP_NONLOCAL(skb);
380 dst->value = skb->sk->sk_receive_queue.qlen;
381 }
382
383 META_COLLECTOR(int_sk_snd_qlen)
384 {
385 SKIP_NONLOCAL(skb);
386 dst->value = skb->sk->sk_write_queue.qlen;
387 }
388
389 META_COLLECTOR(int_sk_wmem_queued)
390 {
391 SKIP_NONLOCAL(skb);
392 dst->value = skb->sk->sk_wmem_queued;
393 }
394
395 META_COLLECTOR(int_sk_fwd_alloc)
396 {
397 SKIP_NONLOCAL(skb);
398 dst->value = skb->sk->sk_forward_alloc;
399 }
400
401 META_COLLECTOR(int_sk_sndbuf)
402 {
403 SKIP_NONLOCAL(skb);
404 dst->value = skb->sk->sk_sndbuf;
405 }
406
407 META_COLLECTOR(int_sk_alloc)
408 {
409 SKIP_NONLOCAL(skb);
410 dst->value = skb->sk->sk_allocation;
411 }
412
413 META_COLLECTOR(int_sk_route_caps)
414 {
415 SKIP_NONLOCAL(skb);
416 dst->value = skb->sk->sk_route_caps;
417 }
418
419 META_COLLECTOR(int_sk_hashent)
420 {
421 SKIP_NONLOCAL(skb);
422 dst->value = skb->sk->sk_hashent;
423 }
424
425 META_COLLECTOR(int_sk_lingertime)
426 {
427 SKIP_NONLOCAL(skb);
428 dst->value = skb->sk->sk_lingertime / HZ;
429 }
430
431 META_COLLECTOR(int_sk_err_qlen)
432 {
433 SKIP_NONLOCAL(skb);
434 dst->value = skb->sk->sk_error_queue.qlen;
435 }
436
437 META_COLLECTOR(int_sk_ack_bl)
438 {
439 SKIP_NONLOCAL(skb);
440 dst->value = skb->sk->sk_ack_backlog;
441 }
442
443 META_COLLECTOR(int_sk_max_ack_bl)
444 {
445 SKIP_NONLOCAL(skb);
446 dst->value = skb->sk->sk_max_ack_backlog;
447 }
448
449 META_COLLECTOR(int_sk_prio)
450 {
451 SKIP_NONLOCAL(skb);
452 dst->value = skb->sk->sk_priority;
453 }
454
455 META_COLLECTOR(int_sk_rcvlowat)
456 {
457 SKIP_NONLOCAL(skb);
458 dst->value = skb->sk->sk_rcvlowat;
459 }
460
461 META_COLLECTOR(int_sk_rcvtimeo)
462 {
463 SKIP_NONLOCAL(skb);
464 dst->value = skb->sk->sk_rcvtimeo / HZ;
465 }
466
467 META_COLLECTOR(int_sk_sndtimeo)
468 {
469 SKIP_NONLOCAL(skb);
470 dst->value = skb->sk->sk_sndtimeo / HZ;
471 }
472
473 META_COLLECTOR(int_sk_sendmsg_off)
474 {
475 SKIP_NONLOCAL(skb);
476 dst->value = skb->sk->sk_sndmsg_off;
477 }
478
479 META_COLLECTOR(int_sk_write_pend)
480 {
481 SKIP_NONLOCAL(skb);
482 dst->value = skb->sk->sk_write_pending;
483 }
484
485 /**************************************************************************
486 * Meta value collectors assignment table
487 **************************************************************************/
488
489 struct meta_ops
490 {
491 void (*get)(struct sk_buff *, struct tcf_pkt_info *,
492 struct meta_value *, struct meta_obj *, int *);
493 };
494
495 #define META_ID(name) TCF_META_ID_##name
496 #define META_FUNC(name) { .get = meta_##name }
497
498 /* Meta value operations table listing all meta value collectors and
499 * assigns them to a type and meta id. */
500 static struct meta_ops __meta_ops[TCF_META_TYPE_MAX+1][TCF_META_ID_MAX+1] = {
501 [TCF_META_TYPE_VAR] = {
502 [META_ID(DEV)] = META_FUNC(var_dev),
503 [META_ID(INDEV)] = META_FUNC(var_indev),
504 [META_ID(REALDEV)] = META_FUNC(var_realdev),
505 [META_ID(SK_BOUND_IF)] = META_FUNC(var_sk_bound_if),
506 },
507 [TCF_META_TYPE_INT] = {
508 [META_ID(RANDOM)] = META_FUNC(int_random),
509 [META_ID(LOADAVG_0)] = META_FUNC(int_loadavg_0),
510 [META_ID(LOADAVG_1)] = META_FUNC(int_loadavg_1),
511 [META_ID(LOADAVG_2)] = META_FUNC(int_loadavg_2),
512 [META_ID(DEV)] = META_FUNC(int_dev),
513 [META_ID(INDEV)] = META_FUNC(int_indev),
514 [META_ID(REALDEV)] = META_FUNC(int_realdev),
515 [META_ID(PRIORITY)] = META_FUNC(int_priority),
516 [META_ID(PROTOCOL)] = META_FUNC(int_protocol),
517 [META_ID(PKTTYPE)] = META_FUNC(int_pkttype),
518 [META_ID(PKTLEN)] = META_FUNC(int_pktlen),
519 [META_ID(DATALEN)] = META_FUNC(int_datalen),
520 [META_ID(MACLEN)] = META_FUNC(int_maclen),
521 #ifdef CONFIG_NETFILTER
522 [META_ID(NFMARK)] = META_FUNC(int_nfmark),
523 #endif
524 [META_ID(TCINDEX)] = META_FUNC(int_tcindex),
525 #ifdef CONFIG_NET_CLS_ACT
526 [META_ID(TCVERDICT)] = META_FUNC(int_tcverd),
527 #endif
528 #ifdef CONFIG_NET_CLS_ROUTE
529 [META_ID(RTCLASSID)] = META_FUNC(int_rtclassid),
530 #endif
531 [META_ID(RTIIF)] = META_FUNC(int_rtiif),
532 [META_ID(SK_FAMILY)] = META_FUNC(int_sk_family),
533 [META_ID(SK_STATE)] = META_FUNC(int_sk_state),
534 [META_ID(SK_REUSE)] = META_FUNC(int_sk_reuse),
535 [META_ID(SK_BOUND_IF)] = META_FUNC(int_sk_bound_if),
536 [META_ID(SK_REFCNT)] = META_FUNC(int_sk_refcnt),
537 [META_ID(SK_RCVBUF)] = META_FUNC(int_sk_rcvbuf),
538 [META_ID(SK_SNDBUF)] = META_FUNC(int_sk_sndbuf),
539 [META_ID(SK_SHUTDOWN)] = META_FUNC(int_sk_shutdown),
540 [META_ID(SK_PROTO)] = META_FUNC(int_sk_proto),
541 [META_ID(SK_TYPE)] = META_FUNC(int_sk_type),
542 [META_ID(SK_RMEM_ALLOC)] = META_FUNC(int_sk_rmem_alloc),
543 [META_ID(SK_WMEM_ALLOC)] = META_FUNC(int_sk_wmem_alloc),
544 [META_ID(SK_OMEM_ALLOC)] = META_FUNC(int_sk_omem_alloc),
545 [META_ID(SK_WMEM_QUEUED)] = META_FUNC(int_sk_wmem_queued),
546 [META_ID(SK_RCV_QLEN)] = META_FUNC(int_sk_rcv_qlen),
547 [META_ID(SK_SND_QLEN)] = META_FUNC(int_sk_snd_qlen),
548 [META_ID(SK_ERR_QLEN)] = META_FUNC(int_sk_err_qlen),
549 [META_ID(SK_FORWARD_ALLOCS)] = META_FUNC(int_sk_fwd_alloc),
550 [META_ID(SK_ALLOCS)] = META_FUNC(int_sk_alloc),
551 [META_ID(SK_ROUTE_CAPS)] = META_FUNC(int_sk_route_caps),
552 [META_ID(SK_HASHENT)] = META_FUNC(int_sk_hashent),
553 [META_ID(SK_LINGERTIME)] = META_FUNC(int_sk_lingertime),
554 [META_ID(SK_ACK_BACKLOG)] = META_FUNC(int_sk_ack_bl),
555 [META_ID(SK_MAX_ACK_BACKLOG)] = META_FUNC(int_sk_max_ack_bl),
556 [META_ID(SK_PRIO)] = META_FUNC(int_sk_prio),
557 [META_ID(SK_RCVLOWAT)] = META_FUNC(int_sk_rcvlowat),
558 [META_ID(SK_RCVTIMEO)] = META_FUNC(int_sk_rcvtimeo),
559 [META_ID(SK_SNDTIMEO)] = META_FUNC(int_sk_sndtimeo),
560 [META_ID(SK_SENDMSG_OFF)] = META_FUNC(int_sk_sendmsg_off),
561 [META_ID(SK_WRITE_PENDING)] = META_FUNC(int_sk_write_pend),
562 }
563 };
564
565 static inline struct meta_ops * meta_ops(struct meta_value *val)
566 {
567 return &__meta_ops[meta_type(val)][meta_id(val)];
568 }
569
570 /**************************************************************************
571 * Type specific operations for TCF_META_TYPE_VAR
572 **************************************************************************/
573
574 static int meta_var_compare(struct meta_obj *a, struct meta_obj *b)
575 {
576 int r = a->len - b->len;
577
578 if (r == 0)
579 r = memcmp((void *) a->value, (void *) b->value, a->len);
580
581 return r;
582 }
583
584 static int meta_var_change(struct meta_value *dst, struct rtattr *rta)
585 {
586 int len = RTA_PAYLOAD(rta);
587
588 dst->val = (unsigned long) kmalloc(len, GFP_KERNEL);
589 if (dst->val == 0UL)
590 return -ENOMEM;
591 memcpy((void *) dst->val, RTA_DATA(rta), len);
592 dst->len = len;
593 return 0;
594 }
595
596 static void meta_var_destroy(struct meta_value *v)
597 {
598 if (v->val)
599 kfree((void *) v->val);
600 }
601
602 static void meta_var_apply_extras(struct meta_value *v,
603 struct meta_obj *dst)
604 {
605 int shift = v->hdr.shift;
606
607 if (shift && shift < dst->len)
608 dst->len -= shift;
609 }
610
611 static int meta_var_dump(struct sk_buff *skb, struct meta_value *v, int tlv)
612 {
613 if (v->val && v->len)
614 RTA_PUT(skb, tlv, v->len, (void *) v->val);
615 return 0;
616
617 rtattr_failure:
618 return -1;
619 }
620
621 /**************************************************************************
622 * Type specific operations for TCF_META_TYPE_INT
623 **************************************************************************/
624
625 static int meta_int_compare(struct meta_obj *a, struct meta_obj *b)
626 {
627 /* Let gcc optimize it, the unlikely is not really based on
628 * some numbers but jump free code for mismatches seems
629 * more logical. */
630 if (unlikely(a->value == b->value))
631 return 0;
632 else if (a->value < b->value)
633 return -1;
634 else
635 return 1;
636 }
637
638 static int meta_int_change(struct meta_value *dst, struct rtattr *rta)
639 {
640 if (RTA_PAYLOAD(rta) >= sizeof(unsigned long)) {
641 dst->val = *(unsigned long *) RTA_DATA(rta);
642 dst->len = sizeof(unsigned long);
643 } else if (RTA_PAYLOAD(rta) == sizeof(u32)) {
644 dst->val = *(u32 *) RTA_DATA(rta);
645 dst->len = sizeof(u32);
646 } else
647 return -EINVAL;
648
649 return 0;
650 }
651
652 static void meta_int_apply_extras(struct meta_value *v,
653 struct meta_obj *dst)
654 {
655 if (v->hdr.shift)
656 dst->value >>= v->hdr.shift;
657
658 if (v->val)
659 dst->value &= v->val;
660 }
661
662 static int meta_int_dump(struct sk_buff *skb, struct meta_value *v, int tlv)
663 {
664 if (v->len == sizeof(unsigned long))
665 RTA_PUT(skb, tlv, sizeof(unsigned long), &v->val);
666 else if (v->len == sizeof(u32)) {
667 u32 d = v->val;
668 RTA_PUT(skb, tlv, sizeof(d), &d);
669 }
670
671 return 0;
672
673 rtattr_failure:
674 return -1;
675 }
676
677 /**************************************************************************
678 * Type specific operations table
679 **************************************************************************/
680
681 struct meta_type_ops
682 {
683 void (*destroy)(struct meta_value *);
684 int (*compare)(struct meta_obj *, struct meta_obj *);
685 int (*change)(struct meta_value *, struct rtattr *);
686 void (*apply_extras)(struct meta_value *, struct meta_obj *);
687 int (*dump)(struct sk_buff *, struct meta_value *, int);
688 };
689
690 static struct meta_type_ops __meta_type_ops[TCF_META_TYPE_MAX+1] = {
691 [TCF_META_TYPE_VAR] = {
692 .destroy = meta_var_destroy,
693 .compare = meta_var_compare,
694 .change = meta_var_change,
695 .apply_extras = meta_var_apply_extras,
696 .dump = meta_var_dump
697 },
698 [TCF_META_TYPE_INT] = {
699 .compare = meta_int_compare,
700 .change = meta_int_change,
701 .apply_extras = meta_int_apply_extras,
702 .dump = meta_int_dump
703 }
704 };
705
706 static inline struct meta_type_ops * meta_type_ops(struct meta_value *v)
707 {
708 return &__meta_type_ops[meta_type(v)];
709 }
710
711 /**************************************************************************
712 * Core
713 **************************************************************************/
714
715 static inline int meta_get(struct sk_buff *skb, struct tcf_pkt_info *info,
716 struct meta_value *v, struct meta_obj *dst)
717 {
718 int err = 0;
719
720 if (meta_id(v) == TCF_META_ID_VALUE) {
721 dst->value = v->val;
722 dst->len = v->len;
723 return 0;
724 }
725
726 meta_ops(v)->get(skb, info, v, dst, &err);
727 if (err < 0)
728 return err;
729
730 if (meta_type_ops(v)->apply_extras)
731 meta_type_ops(v)->apply_extras(v, dst);
732
733 return 0;
734 }
735
736 static int em_meta_match(struct sk_buff *skb, struct tcf_ematch *m,
737 struct tcf_pkt_info *info)
738 {
739 int r;
740 struct meta_match *meta = (struct meta_match *) m->data;
741 struct meta_obj l_value, r_value;
742
743 if (meta_get(skb, info, &meta->lvalue, &l_value) < 0 ||
744 meta_get(skb, info, &meta->rvalue, &r_value) < 0)
745 return 0;
746
747 r = meta_type_ops(&meta->lvalue)->compare(&l_value, &r_value);
748
749 switch (meta->lvalue.hdr.op) {
750 case TCF_EM_OPND_EQ:
751 return !r;
752 case TCF_EM_OPND_LT:
753 return r < 0;
754 case TCF_EM_OPND_GT:
755 return r > 0;
756 }
757
758 return 0;
759 }
760
761 static inline void meta_delete(struct meta_match *meta)
762 {
763 struct meta_type_ops *ops = meta_type_ops(&meta->lvalue);
764
765 if (ops && ops->destroy) {
766 ops->destroy(&meta->lvalue);
767 ops->destroy(&meta->rvalue);
768 }
769
770 kfree(meta);
771 }
772
773 static inline int meta_change_data(struct meta_value *dst, struct rtattr *rta)
774 {
775 if (rta) {
776 if (RTA_PAYLOAD(rta) == 0)
777 return -EINVAL;
778
779 return meta_type_ops(dst)->change(dst, rta);
780 }
781
782 return 0;
783 }
784
785 static inline int meta_is_supported(struct meta_value *val)
786 {
787 return (!meta_id(val) || meta_ops(val)->get);
788 }
789
790 static int em_meta_change(struct tcf_proto *tp, void *data, int len,
791 struct tcf_ematch *m)
792 {
793 int err = -EINVAL;
794 struct rtattr *tb[TCA_EM_META_MAX];
795 struct tcf_meta_hdr *hdr;
796 struct meta_match *meta = NULL;
797
798 if (rtattr_parse(tb, TCA_EM_META_MAX, data, len) < 0)
799 goto errout;
800
801 if (tb[TCA_EM_META_HDR-1] == NULL ||
802 RTA_PAYLOAD(tb[TCA_EM_META_HDR-1]) < sizeof(*hdr))
803 goto errout;
804 hdr = RTA_DATA(tb[TCA_EM_META_HDR-1]);
805
806 if (TCF_META_TYPE(hdr->left.kind) != TCF_META_TYPE(hdr->right.kind) ||
807 TCF_META_TYPE(hdr->left.kind) > TCF_META_TYPE_MAX ||
808 TCF_META_ID(hdr->left.kind) > TCF_META_ID_MAX ||
809 TCF_META_ID(hdr->right.kind) > TCF_META_ID_MAX)
810 goto errout;
811
812 meta = kmalloc(sizeof(*meta), GFP_KERNEL);
813 if (meta == NULL)
814 goto errout;
815 memset(meta, 0, sizeof(*meta));
816
817 memcpy(&meta->lvalue.hdr, &hdr->left, sizeof(hdr->left));
818 memcpy(&meta->rvalue.hdr, &hdr->right, sizeof(hdr->right));
819
820 if (!meta_is_supported(&meta->lvalue) ||
821 !meta_is_supported(&meta->rvalue)) {
822 err = -EOPNOTSUPP;
823 goto errout;
824 }
825
826 if (meta_change_data(&meta->lvalue, tb[TCA_EM_META_LVALUE-1]) < 0 ||
827 meta_change_data(&meta->rvalue, tb[TCA_EM_META_RVALUE-1]) < 0)
828 goto errout;
829
830 m->datalen = sizeof(*meta);
831 m->data = (unsigned long) meta;
832
833 err = 0;
834 errout:
835 if (err && meta)
836 meta_delete(meta);
837 return err;
838 }
839
840 static void em_meta_destroy(struct tcf_proto *tp, struct tcf_ematch *m)
841 {
842 if (m)
843 meta_delete((struct meta_match *) m->data);
844 }
845
846 static int em_meta_dump(struct sk_buff *skb, struct tcf_ematch *em)
847 {
848 struct meta_match *meta = (struct meta_match *) em->data;
849 struct tcf_meta_hdr hdr;
850 struct meta_type_ops *ops;
851
852 memset(&hdr, 0, sizeof(hdr));
853 memcpy(&hdr.left, &meta->lvalue.hdr, sizeof(hdr.left));
854 memcpy(&hdr.right, &meta->rvalue.hdr, sizeof(hdr.right));
855
856 RTA_PUT(skb, TCA_EM_META_HDR, sizeof(hdr), &hdr);
857
858 ops = meta_type_ops(&meta->lvalue);
859 if (ops->dump(skb, &meta->lvalue, TCA_EM_META_LVALUE) < 0 ||
860 ops->dump(skb, &meta->rvalue, TCA_EM_META_RVALUE) < 0)
861 goto rtattr_failure;
862
863 return 0;
864
865 rtattr_failure:
866 return -1;
867 }
868
869 static struct tcf_ematch_ops em_meta_ops = {
870 .kind = TCF_EM_META,
871 .change = em_meta_change,
872 .match = em_meta_match,
873 .destroy = em_meta_destroy,
874 .dump = em_meta_dump,
875 .owner = THIS_MODULE,
876 .link = LIST_HEAD_INIT(em_meta_ops.link)
877 };
878
879 static int __init init_em_meta(void)
880 {
881 return tcf_em_register(&em_meta_ops);
882 }
883
884 static void __exit exit_em_meta(void)
885 {
886 tcf_em_unregister(&em_meta_ops);
887 }
888
889 MODULE_LICENSE("GPL");
890
891 module_init(init_em_meta);
892 module_exit(exit_em_meta);
kernel-based virtual machine