xref: /kernel/linux/linux-5.10/net/sched/em_meta.c (revision 8c2ecf20) 
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * net/sched/em_meta.c	Metadata ematch
4 *
5 * Authors:	Thomas Graf <tgraf@suug.ch>
6 *
7 * ==========================================================================
8 *
9 * 	The metadata ematch compares two meta objects where each object
10 * 	represents either a meta value stored in the kernel or a static
11 * 	value provided by userspace. The objects are not provided by
12 * 	userspace itself but rather a definition providing the information
13 * 	to build them. Every object is of a certain type which must be
14 * 	equal to the object it is being compared to.
15 *
16 * 	The definition of a objects conists of the type (meta type), a
17 * 	identifier (meta id) and additional type specific information.
18 * 	The meta id is either TCF_META_TYPE_VALUE for values provided by
19 * 	userspace or a index to the meta operations table consisting of
20 * 	function pointers to type specific meta data collectors returning
21 * 	the value of the requested meta value.
22 *
23 * 	         lvalue                                   rvalue
24 * 	      +-----------+                           +-----------+
25 * 	      | type: INT |                           | type: INT |
26 * 	 def  | id: DEV   |                           | id: VALUE |
27 * 	      | data:     |                           | data: 3   |
28 * 	      +-----------+                           +-----------+
29 * 	            |                                       |
30 * 	            ---> meta_ops[INT][DEV](...)            |
31 *	                      |                             |
32 * 	            -----------                             |
33 * 	            V                                       V
34 * 	      +-----------+                           +-----------+
35 * 	      | type: INT |                           | type: INT |
36 * 	 obj  | id: DEV |                             | id: VALUE |
37 * 	      | data: 2   |<--data got filled out     | data: 3   |
38 * 	      +-----------+                           +-----------+
39 * 	            |                                         |
40 * 	            --------------> 2  equals 3 <--------------
41 *
42 * 	This is a simplified schema, the complexity varies depending
43 * 	on the meta type. Obviously, the length of the data must also
44 * 	be provided for non-numeric types.
45 *
46 * 	Additionally, type dependent modifiers such as shift operators
47 * 	or mask may be applied to extend the functionaliy. As of now,
48 * 	the variable length type supports shifting the byte string to
49 * 	the right, eating up any number of octets and thus supporting
50 * 	wildcard interface name comparisons such as "ppp%" matching
51 * 	ppp0..9.
52 *
53 * 	NOTE: Certain meta values depend on other subsystems and are
54 * 	      only available if that subsystem is enabled in the kernel.
55 */
56
57#include <linux/slab.h>
58#include <linux/module.h>
59#include <linux/types.h>
60#include <linux/kernel.h>
61#include <linux/sched.h>
62#include <linux/sched/loadavg.h>
63#include <linux/string.h>
64#include <linux/skbuff.h>
65#include <linux/random.h>
66#include <linux/if_vlan.h>
67#include <linux/tc_ematch/tc_em_meta.h>
68#include <net/dst.h>
69#include <net/route.h>
70#include <net/pkt_cls.h>
71#include <net/sock.h>
72
73struct meta_obj {
74	unsigned long		value;
75	unsigned int		len;
76};
77
78struct meta_value {
79	struct tcf_meta_val	hdr;
80	unsigned long		val;
81	unsigned int		len;
82};
83
84struct meta_match {
85	struct meta_value	lvalue;
86	struct meta_value	rvalue;
87};
88
89static inline int meta_id(struct meta_value *v)
90{
91	return TCF_META_ID(v->hdr.kind);
92}
93
94static 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
107META_COLLECTOR(int_random)
108{
109	get_random_bytes(&dst->value, sizeof(dst->value));
110}
111
112static 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
120META_COLLECTOR(int_loadavg_0)
121{
122	dst->value = fixed_loadavg(avenrun[0]);
123}
124
125META_COLLECTOR(int_loadavg_1)
126{
127	dst->value = fixed_loadavg(avenrun[1]);
128}
129
130META_COLLECTOR(int_loadavg_2)
131{
132	dst->value = fixed_loadavg(avenrun[2]);
133}
134
135/**************************************************************************
136 * Device names & indices
137 **************************************************************************/
138
139static 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
148static 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
158META_COLLECTOR(int_dev)
159{
160	*err = int_dev(skb->dev, dst);
161}
162
163META_COLLECTOR(var_dev)
164{
165	*err = var_dev(skb->dev, dst);
166}
167
168/**************************************************************************
169 * vlan tag
170 **************************************************************************/
171
172META_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
190META_COLLECTOR(int_priority)
191{
192	dst->value = skb->priority;
193}
194
195META_COLLECTOR(int_protocol)
196{
197	/* Let userspace take care of the byte ordering */
198	dst->value = skb_protocol(skb, false);
199}
200
201META_COLLECTOR(int_pkttype)
202{
203	dst->value = skb->pkt_type;
204}
205
206META_COLLECTOR(int_pktlen)
207{
208	dst->value = skb->len;
209}
210
211META_COLLECTOR(int_datalen)
212{
213	dst->value = skb->data_len;
214}
215
216META_COLLECTOR(int_maclen)
217{
218	dst->value = skb->mac_len;
219}
220
221META_COLLECTOR(int_rxhash)
222{
223	dst->value = skb_get_hash(skb);
224}
225
226/**************************************************************************
227 * Netfilter
228 **************************************************************************/
229
230META_COLLECTOR(int_mark)
231{
232	dst->value = skb->mark;
233}
234
235/**************************************************************************
236 * Traffic Control
237 **************************************************************************/
238
239META_COLLECTOR(int_tcindex)
240{
241	dst->value = skb->tc_index;
242}
243
244/**************************************************************************
245 * Routing
246 **************************************************************************/
247
248META_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
260META_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
275META_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
284META_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
293META_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
302META_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
312META_COLLECTOR(var_sk_bound_if)
313{
314	if (skip_nonlocal(skb)) {
315		*err = -1;
316		return;
317	}
318
319	if (skb->sk->sk_bound_dev_if == 0) {
320		dst->value = (unsigned long) "any";
321		dst->len = 3;
322	} else {
323		struct net_device *dev;
324
325		rcu_read_lock();
326		dev = dev_get_by_index_rcu(sock_net(skb->sk),
327					   skb->sk->sk_bound_dev_if);
328		*err = var_dev(dev, dst);
329		rcu_read_unlock();
330	}
331}
332
333META_COLLECTOR(int_sk_refcnt)
334{
335	if (skip_nonlocal(skb)) {
336		*err = -1;
337		return;
338	}
339	dst->value = refcount_read(&skb->sk->sk_refcnt);
340}
341
342META_COLLECTOR(int_sk_rcvbuf)
343{
344	const struct sock *sk = skb_to_full_sk(skb);
345
346	if (!sk) {
347		*err = -1;
348		return;
349	}
350	dst->value = sk->sk_rcvbuf;
351}
352
353META_COLLECTOR(int_sk_shutdown)
354{
355	const struct sock *sk = skb_to_full_sk(skb);
356
357	if (!sk) {
358		*err = -1;
359		return;
360	}
361	dst->value = sk->sk_shutdown;
362}
363
364META_COLLECTOR(int_sk_proto)
365{
366	const struct sock *sk = skb_to_full_sk(skb);
367
368	if (!sk) {
369		*err = -1;
370		return;
371	}
372	dst->value = sk->sk_protocol;
373}
374
375META_COLLECTOR(int_sk_type)
376{
377	const struct sock *sk = skb_to_full_sk(skb);
378
379	if (!sk) {
380		*err = -1;
381		return;
382	}
383	dst->value = sk->sk_type;
384}
385
386META_COLLECTOR(int_sk_rmem_alloc)
387{
388	const struct sock *sk = skb_to_full_sk(skb);
389
390	if (!sk) {
391		*err = -1;
392		return;
393	}
394	dst->value = sk_rmem_alloc_get(sk);
395}
396
397META_COLLECTOR(int_sk_wmem_alloc)
398{
399	const struct sock *sk = skb_to_full_sk(skb);
400
401	if (!sk) {
402		*err = -1;
403		return;
404	}
405	dst->value = sk_wmem_alloc_get(sk);
406}
407
408META_COLLECTOR(int_sk_omem_alloc)
409{
410	const struct sock *sk = skb_to_full_sk(skb);
411
412	if (!sk) {
413		*err = -1;
414		return;
415	}
416	dst->value = atomic_read(&sk->sk_omem_alloc);
417}
418
419META_COLLECTOR(int_sk_rcv_qlen)
420{
421	const struct sock *sk = skb_to_full_sk(skb);
422
423	if (!sk) {
424		*err = -1;
425		return;
426	}
427	dst->value = sk->sk_receive_queue.qlen;
428}
429
430META_COLLECTOR(int_sk_snd_qlen)
431{
432	const struct sock *sk = skb_to_full_sk(skb);
433
434	if (!sk) {
435		*err = -1;
436		return;
437	}
438	dst->value = sk->sk_write_queue.qlen;
439}
440
441META_COLLECTOR(int_sk_wmem_queued)
442{
443	const struct sock *sk = skb_to_full_sk(skb);
444
445	if (!sk) {
446		*err = -1;
447		return;
448	}
449	dst->value = READ_ONCE(sk->sk_wmem_queued);
450}
451
452META_COLLECTOR(int_sk_fwd_alloc)
453{
454	const struct sock *sk = skb_to_full_sk(skb);
455
456	if (!sk) {
457		*err = -1;
458		return;
459	}
460	dst->value = sk->sk_forward_alloc;
461}
462
463META_COLLECTOR(int_sk_sndbuf)
464{
465	const struct sock *sk = skb_to_full_sk(skb);
466
467	if (!sk) {
468		*err = -1;
469		return;
470	}
471	dst->value = sk->sk_sndbuf;
472}
473
474META_COLLECTOR(int_sk_alloc)
475{
476	const struct sock *sk = skb_to_full_sk(skb);
477
478	if (!sk) {
479		*err = -1;
480		return;
481	}
482	dst->value = (__force int) sk->sk_allocation;
483}
484
485META_COLLECTOR(int_sk_hash)
486{
487	if (skip_nonlocal(skb)) {
488		*err = -1;
489		return;
490	}
491	dst->value = skb->sk->sk_hash;
492}
493
494META_COLLECTOR(int_sk_lingertime)
495{
496	const struct sock *sk = skb_to_full_sk(skb);
497
498	if (!sk) {
499		*err = -1;
500		return;
501	}
502	dst->value = sk->sk_lingertime / HZ;
503}
504
505META_COLLECTOR(int_sk_err_qlen)
506{
507	const struct sock *sk = skb_to_full_sk(skb);
508
509	if (!sk) {
510		*err = -1;
511		return;
512	}
513	dst->value = sk->sk_error_queue.qlen;
514}
515
516META_COLLECTOR(int_sk_ack_bl)
517{
518	const struct sock *sk = skb_to_full_sk(skb);
519
520	if (!sk) {
521		*err = -1;
522		return;
523	}
524	dst->value = READ_ONCE(sk->sk_ack_backlog);
525}
526
527META_COLLECTOR(int_sk_max_ack_bl)
528{
529	const struct sock *sk = skb_to_full_sk(skb);
530
531	if (!sk) {
532		*err = -1;
533		return;
534	}
535	dst->value = READ_ONCE(sk->sk_max_ack_backlog);
536}
537
538META_COLLECTOR(int_sk_prio)
539{
540	const struct sock *sk = skb_to_full_sk(skb);
541
542	if (!sk) {
543		*err = -1;
544		return;
545	}
546	dst->value = sk->sk_priority;
547}
548
549META_COLLECTOR(int_sk_rcvlowat)
550{
551	const struct sock *sk = skb_to_full_sk(skb);
552
553	if (!sk) {
554		*err = -1;
555		return;
556	}
557	dst->value = READ_ONCE(sk->sk_rcvlowat);
558}
559
560META_COLLECTOR(int_sk_rcvtimeo)
561{
562	const struct sock *sk = skb_to_full_sk(skb);
563
564	if (!sk) {
565		*err = -1;
566		return;
567	}
568	dst->value = sk->sk_rcvtimeo / HZ;
569}
570
571META_COLLECTOR(int_sk_sndtimeo)
572{
573	const struct sock *sk = skb_to_full_sk(skb);
574
575	if (!sk) {
576		*err = -1;
577		return;
578	}
579	dst->value = sk->sk_sndtimeo / HZ;
580}
581
582META_COLLECTOR(int_sk_sendmsg_off)
583{
584	const struct sock *sk = skb_to_full_sk(skb);
585
586	if (!sk) {
587		*err = -1;
588		return;
589	}
590	dst->value = sk->sk_frag.offset;
591}
592
593META_COLLECTOR(int_sk_write_pend)
594{
595	const struct sock *sk = skb_to_full_sk(skb);
596
597	if (!sk) {
598		*err = -1;
599		return;
600	}
601	dst->value = sk->sk_write_pending;
602}
603
604/**************************************************************************
605 * Meta value collectors assignment table
606 **************************************************************************/
607
608struct meta_ops {
609	void		(*get)(struct sk_buff *, struct tcf_pkt_info *,
610			       struct meta_value *, struct meta_obj *, int *);
611};
612
613#define META_ID(name) TCF_META_ID_##name
614#define META_FUNC(name) { .get = meta_##name }
615
616/* Meta value operations table listing all meta value collectors and
617 * assigns them to a type and meta id. */
618static struct meta_ops __meta_ops[TCF_META_TYPE_MAX + 1][TCF_META_ID_MAX + 1] = {
619	[TCF_META_TYPE_VAR] = {
620		[META_ID(DEV)]			= META_FUNC(var_dev),
621		[META_ID(SK_BOUND_IF)] 		= META_FUNC(var_sk_bound_if),
622	},
623	[TCF_META_TYPE_INT] = {
624		[META_ID(RANDOM)]		= META_FUNC(int_random),
625		[META_ID(LOADAVG_0)]		= META_FUNC(int_loadavg_0),
626		[META_ID(LOADAVG_1)]		= META_FUNC(int_loadavg_1),
627		[META_ID(LOADAVG_2)]		= META_FUNC(int_loadavg_2),
628		[META_ID(DEV)]			= META_FUNC(int_dev),
629		[META_ID(PRIORITY)]		= META_FUNC(int_priority),
630		[META_ID(PROTOCOL)]		= META_FUNC(int_protocol),
631		[META_ID(PKTTYPE)]		= META_FUNC(int_pkttype),
632		[META_ID(PKTLEN)]		= META_FUNC(int_pktlen),
633		[META_ID(DATALEN)]		= META_FUNC(int_datalen),
634		[META_ID(MACLEN)]		= META_FUNC(int_maclen),
635		[META_ID(NFMARK)]		= META_FUNC(int_mark),
636		[META_ID(TCINDEX)]		= META_FUNC(int_tcindex),
637		[META_ID(RTCLASSID)]		= META_FUNC(int_rtclassid),
638		[META_ID(RTIIF)]		= META_FUNC(int_rtiif),
639		[META_ID(SK_FAMILY)]		= META_FUNC(int_sk_family),
640		[META_ID(SK_STATE)]		= META_FUNC(int_sk_state),
641		[META_ID(SK_REUSE)]		= META_FUNC(int_sk_reuse),
642		[META_ID(SK_BOUND_IF)]		= META_FUNC(int_sk_bound_if),
643		[META_ID(SK_REFCNT)]		= META_FUNC(int_sk_refcnt),
644		[META_ID(SK_RCVBUF)]		= META_FUNC(int_sk_rcvbuf),
645		[META_ID(SK_SNDBUF)]		= META_FUNC(int_sk_sndbuf),
646		[META_ID(SK_SHUTDOWN)]		= META_FUNC(int_sk_shutdown),
647		[META_ID(SK_PROTO)]		= META_FUNC(int_sk_proto),
648		[META_ID(SK_TYPE)]		= META_FUNC(int_sk_type),
649		[META_ID(SK_RMEM_ALLOC)]	= META_FUNC(int_sk_rmem_alloc),
650		[META_ID(SK_WMEM_ALLOC)]	= META_FUNC(int_sk_wmem_alloc),
651		[META_ID(SK_OMEM_ALLOC)]	= META_FUNC(int_sk_omem_alloc),
652		[META_ID(SK_WMEM_QUEUED)]	= META_FUNC(int_sk_wmem_queued),
653		[META_ID(SK_RCV_QLEN)]		= META_FUNC(int_sk_rcv_qlen),
654		[META_ID(SK_SND_QLEN)]		= META_FUNC(int_sk_snd_qlen),
655		[META_ID(SK_ERR_QLEN)]		= META_FUNC(int_sk_err_qlen),
656		[META_ID(SK_FORWARD_ALLOCS)]	= META_FUNC(int_sk_fwd_alloc),
657		[META_ID(SK_ALLOCS)]		= META_FUNC(int_sk_alloc),
658		[META_ID(SK_HASH)]		= META_FUNC(int_sk_hash),
659		[META_ID(SK_LINGERTIME)]	= META_FUNC(int_sk_lingertime),
660		[META_ID(SK_ACK_BACKLOG)]	= META_FUNC(int_sk_ack_bl),
661		[META_ID(SK_MAX_ACK_BACKLOG)]	= META_FUNC(int_sk_max_ack_bl),
662		[META_ID(SK_PRIO)]		= META_FUNC(int_sk_prio),
663		[META_ID(SK_RCVLOWAT)]		= META_FUNC(int_sk_rcvlowat),
664		[META_ID(SK_RCVTIMEO)]		= META_FUNC(int_sk_rcvtimeo),
665		[META_ID(SK_SNDTIMEO)]		= META_FUNC(int_sk_sndtimeo),
666		[META_ID(SK_SENDMSG_OFF)]	= META_FUNC(int_sk_sendmsg_off),
667		[META_ID(SK_WRITE_PENDING)]	= META_FUNC(int_sk_write_pend),
668		[META_ID(VLAN_TAG)]		= META_FUNC(int_vlan_tag),
669		[META_ID(RXHASH)]		= META_FUNC(int_rxhash),
670	}
671};
672
673static inline struct meta_ops *meta_ops(struct meta_value *val)
674{
675	return &__meta_ops[meta_type(val)][meta_id(val)];
676}
677
678/**************************************************************************
679 * Type specific operations for TCF_META_TYPE_VAR
680 **************************************************************************/
681
682static int meta_var_compare(struct meta_obj *a, struct meta_obj *b)
683{
684	int r = a->len - b->len;
685
686	if (r == 0)
687		r = memcmp((void *) a->value, (void *) b->value, a->len);
688
689	return r;
690}
691
692static int meta_var_change(struct meta_value *dst, struct nlattr *nla)
693{
694	int len = nla_len(nla);
695
696	dst->val = (unsigned long)kmemdup(nla_data(nla), len, GFP_KERNEL);
697	if (dst->val == 0UL)
698		return -ENOMEM;
699	dst->len = len;
700	return 0;
701}
702
703static void meta_var_destroy(struct meta_value *v)
704{
705	kfree((void *) v->val);
706}
707
708static void meta_var_apply_extras(struct meta_value *v,
709				  struct meta_obj *dst)
710{
711	int shift = v->hdr.shift;
712
713	if (shift && shift < dst->len)
714		dst->len -= shift;
715}
716
717static int meta_var_dump(struct sk_buff *skb, struct meta_value *v, int tlv)
718{
719	if (v->val && v->len &&
720	    nla_put(skb, tlv, v->len, (void *) v->val))
721		goto nla_put_failure;
722	return 0;
723
724nla_put_failure:
725	return -1;
726}
727
728/**************************************************************************
729 * Type specific operations for TCF_META_TYPE_INT
730 **************************************************************************/
731
732static int meta_int_compare(struct meta_obj *a, struct meta_obj *b)
733{
734	/* Let gcc optimize it, the unlikely is not really based on
735	 * some numbers but jump free code for mismatches seems
736	 * more logical. */
737	if (unlikely(a->value == b->value))
738		return 0;
739	else if (a->value < b->value)
740		return -1;
741	else
742		return 1;
743}
744
745static int meta_int_change(struct meta_value *dst, struct nlattr *nla)
746{
747	if (nla_len(nla) >= sizeof(unsigned long)) {
748		dst->val = *(unsigned long *) nla_data(nla);
749		dst->len = sizeof(unsigned long);
750	} else if (nla_len(nla) == sizeof(u32)) {
751		dst->val = nla_get_u32(nla);
752		dst->len = sizeof(u32);
753	} else
754		return -EINVAL;
755
756	return 0;
757}
758
759static void meta_int_apply_extras(struct meta_value *v,
760				  struct meta_obj *dst)
761{
762	if (v->hdr.shift)
763		dst->value >>= v->hdr.shift;
764
765	if (v->val)
766		dst->value &= v->val;
767}
768
769static int meta_int_dump(struct sk_buff *skb, struct meta_value *v, int tlv)
770{
771	if (v->len == sizeof(unsigned long)) {
772		if (nla_put(skb, tlv, sizeof(unsigned long), &v->val))
773			goto nla_put_failure;
774	} else if (v->len == sizeof(u32)) {
775		if (nla_put_u32(skb, tlv, v->val))
776			goto nla_put_failure;
777	}
778
779	return 0;
780
781nla_put_failure:
782	return -1;
783}
784
785/**************************************************************************
786 * Type specific operations table
787 **************************************************************************/
788
789struct meta_type_ops {
790	void	(*destroy)(struct meta_value *);
791	int	(*compare)(struct meta_obj *, struct meta_obj *);
792	int	(*change)(struct meta_value *, struct nlattr *);
793	void	(*apply_extras)(struct meta_value *, struct meta_obj *);
794	int	(*dump)(struct sk_buff *, struct meta_value *, int);
795};
796
797static const struct meta_type_ops __meta_type_ops[TCF_META_TYPE_MAX + 1] = {
798	[TCF_META_TYPE_VAR] = {
799		.destroy = meta_var_destroy,
800		.compare = meta_var_compare,
801		.change = meta_var_change,
802		.apply_extras = meta_var_apply_extras,
803		.dump = meta_var_dump
804	},
805	[TCF_META_TYPE_INT] = {
806		.compare = meta_int_compare,
807		.change = meta_int_change,
808		.apply_extras = meta_int_apply_extras,
809		.dump = meta_int_dump
810	}
811};
812
813static inline const struct meta_type_ops *meta_type_ops(struct meta_value *v)
814{
815	return &__meta_type_ops[meta_type(v)];
816}
817
818/**************************************************************************
819 * Core
820 **************************************************************************/
821
822static int meta_get(struct sk_buff *skb, struct tcf_pkt_info *info,
823		    struct meta_value *v, struct meta_obj *dst)
824{
825	int err = 0;
826
827	if (meta_id(v) == TCF_META_ID_VALUE) {
828		dst->value = v->val;
829		dst->len = v->len;
830		return 0;
831	}
832
833	meta_ops(v)->get(skb, info, v, dst, &err);
834	if (err < 0)
835		return err;
836
837	if (meta_type_ops(v)->apply_extras)
838		meta_type_ops(v)->apply_extras(v, dst);
839
840	return 0;
841}
842
843static int em_meta_match(struct sk_buff *skb, struct tcf_ematch *m,
844			 struct tcf_pkt_info *info)
845{
846	int r;
847	struct meta_match *meta = (struct meta_match *) m->data;
848	struct meta_obj l_value, r_value;
849
850	if (meta_get(skb, info, &meta->lvalue, &l_value) < 0 ||
851	    meta_get(skb, info, &meta->rvalue, &r_value) < 0)
852		return 0;
853
854	r = meta_type_ops(&meta->lvalue)->compare(&l_value, &r_value);
855
856	switch (meta->lvalue.hdr.op) {
857	case TCF_EM_OPND_EQ:
858		return !r;
859	case TCF_EM_OPND_LT:
860		return r < 0;
861	case TCF_EM_OPND_GT:
862		return r > 0;
863	}
864
865	return 0;
866}
867
868static void meta_delete(struct meta_match *meta)
869{
870	if (meta) {
871		const struct meta_type_ops *ops = meta_type_ops(&meta->lvalue);
872
873		if (ops && ops->destroy) {
874			ops->destroy(&meta->lvalue);
875			ops->destroy(&meta->rvalue);
876		}
877	}
878
879	kfree(meta);
880}
881
882static inline int meta_change_data(struct meta_value *dst, struct nlattr *nla)
883{
884	if (nla) {
885		if (nla_len(nla) == 0)
886			return -EINVAL;
887
888		return meta_type_ops(dst)->change(dst, nla);
889	}
890
891	return 0;
892}
893
894static inline int meta_is_supported(struct meta_value *val)
895{
896	return !meta_id(val) || meta_ops(val)->get;
897}
898
899static const struct nla_policy meta_policy[TCA_EM_META_MAX + 1] = {
900	[TCA_EM_META_HDR]	= { .len = sizeof(struct tcf_meta_hdr) },
901};
902
903static int em_meta_change(struct net *net, void *data, int len,
904			  struct tcf_ematch *m)
905{
906	int err;
907	struct nlattr *tb[TCA_EM_META_MAX + 1];
908	struct tcf_meta_hdr *hdr;
909	struct meta_match *meta = NULL;
910
911	err = nla_parse_deprecated(tb, TCA_EM_META_MAX, data, len,
912				   meta_policy, NULL);
913	if (err < 0)
914		goto errout;
915
916	err = -EINVAL;
917	if (tb[TCA_EM_META_HDR] == NULL)
918		goto errout;
919	hdr = nla_data(tb[TCA_EM_META_HDR]);
920
921	if (TCF_META_TYPE(hdr->left.kind) != TCF_META_TYPE(hdr->right.kind) ||
922	    TCF_META_TYPE(hdr->left.kind) > TCF_META_TYPE_MAX ||
923	    TCF_META_ID(hdr->left.kind) > TCF_META_ID_MAX ||
924	    TCF_META_ID(hdr->right.kind) > TCF_META_ID_MAX)
925		goto errout;
926
927	meta = kzalloc(sizeof(*meta), GFP_KERNEL);
928	if (meta == NULL) {
929		err = -ENOMEM;
930		goto errout;
931	}
932
933	memcpy(&meta->lvalue.hdr, &hdr->left, sizeof(hdr->left));
934	memcpy(&meta->rvalue.hdr, &hdr->right, sizeof(hdr->right));
935
936	if (!meta_is_supported(&meta->lvalue) ||
937	    !meta_is_supported(&meta->rvalue)) {
938		err = -EOPNOTSUPP;
939		goto errout;
940	}
941
942	if (meta_change_data(&meta->lvalue, tb[TCA_EM_META_LVALUE]) < 0 ||
943	    meta_change_data(&meta->rvalue, tb[TCA_EM_META_RVALUE]) < 0)
944		goto errout;
945
946	m->datalen = sizeof(*meta);
947	m->data = (unsigned long) meta;
948
949	err = 0;
950errout:
951	if (err && meta)
952		meta_delete(meta);
953	return err;
954}
955
956static void em_meta_destroy(struct tcf_ematch *m)
957{
958	if (m)
959		meta_delete((struct meta_match *) m->data);
960}
961
962static int em_meta_dump(struct sk_buff *skb, struct tcf_ematch *em)
963{
964	struct meta_match *meta = (struct meta_match *) em->data;
965	struct tcf_meta_hdr hdr;
966	const struct meta_type_ops *ops;
967
968	memset(&hdr, 0, sizeof(hdr));
969	memcpy(&hdr.left, &meta->lvalue.hdr, sizeof(hdr.left));
970	memcpy(&hdr.right, &meta->rvalue.hdr, sizeof(hdr.right));
971
972	if (nla_put(skb, TCA_EM_META_HDR, sizeof(hdr), &hdr))
973		goto nla_put_failure;
974
975	ops = meta_type_ops(&meta->lvalue);
976	if (ops->dump(skb, &meta->lvalue, TCA_EM_META_LVALUE) < 0 ||
977	    ops->dump(skb, &meta->rvalue, TCA_EM_META_RVALUE) < 0)
978		goto nla_put_failure;
979
980	return 0;
981
982nla_put_failure:
983	return -1;
984}
985
986static struct tcf_ematch_ops em_meta_ops = {
987	.kind	  = TCF_EM_META,
988	.change	  = em_meta_change,
989	.match	  = em_meta_match,
990	.destroy  = em_meta_destroy,
991	.dump	  = em_meta_dump,
992	.owner	  = THIS_MODULE,
993	.link	  = LIST_HEAD_INIT(em_meta_ops.link)
994};
995
996static int __init init_em_meta(void)
997{
998	return tcf_em_register(&em_meta_ops);
999}
1000
1001static void __exit exit_em_meta(void)
1002{
1003	tcf_em_unregister(&em_meta_ops);
1004}
1005
1006MODULE_LICENSE("GPL");
1007
1008module_init(init_em_meta);
1009module_exit(exit_em_meta);
1010
1011MODULE_ALIAS_TCF_EMATCH(TCF_EM_META);
1012