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 * 	Additionally, type dependent 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
76struct meta_obj {
77	unsigned long		value;
78	unsigned int		len;
79};
80
81struct meta_value {
82	struct tcf_meta_val	hdr;
83	unsigned long		val;
84	unsigned int		len;
85};
86
87struct meta_match {
88	struct meta_value	lvalue;
89	struct meta_value	rvalue;
90};
91
92static inline int meta_id(struct meta_value *v)
93{
94	return TCF_META_ID(v->hdr.kind);
95}
96
97static inline int meta_type(struct meta_value *v)
98{
99	return TCF_META_TYPE(v->hdr.kind);
100}
101
102#define META_COLLECTOR(FUNC) static void meta_##FUNC(struct sk_buff *skb, \
103	struct tcf_pkt_info *info, struct meta_value *v, \
104	struct meta_obj *dst, int *err)
105
106/**************************************************************************
107 * System status & misc
108 **************************************************************************/
109
110META_COLLECTOR(int_random)
111{
112	get_random_bytes(&dst->value, sizeof(dst->value));
113}
114
115static inline unsigned long fixed_loadavg(int load)
116{
117	int rnd_load = load + (FIXED_1/200);
118	int rnd_frac = ((rnd_load & (FIXED_1-1)) * 100) >> FSHIFT;
119
120	return ((rnd_load >> FSHIFT) * 100) + rnd_frac;
121}
122
123META_COLLECTOR(int_loadavg_0)
124{
125	dst->value = fixed_loadavg(avenrun[0]);
126}
127
128META_COLLECTOR(int_loadavg_1)
129{
130	dst->value = fixed_loadavg(avenrun[1]);
131}
132
133META_COLLECTOR(int_loadavg_2)
134{
135	dst->value = fixed_loadavg(avenrun[2]);
136}
137
138/**************************************************************************
139 * Device names & indices
140 **************************************************************************/
141
142static inline int int_dev(struct net_device *dev, struct meta_obj *dst)
143{
144	if (unlikely(dev == NULL))
145		return -1;
146
147	dst->value = dev->ifindex;
148	return 0;
149}
150
151static inline int var_dev(struct net_device *dev, struct meta_obj *dst)
152{
153	if (unlikely(dev == NULL))
154		return -1;
155
156	dst->value = (unsigned long) dev->name;
157	dst->len = strlen(dev->name);
158	return 0;
159}
160
161META_COLLECTOR(int_dev)
162{
163	*err = int_dev(skb->dev, dst);
164}
165
166META_COLLECTOR(var_dev)
167{
168	*err = var_dev(skb->dev, dst);
169}
170
171/**************************************************************************
172 * vlan tag
173 **************************************************************************/
174
175META_COLLECTOR(int_vlan_tag)
176{
177	unsigned short tag;
178
179	tag = vlan_tx_tag_get(skb);
180	if (!tag && __vlan_get_tag(skb, &tag))
181		*err = -1;
182	else
183		dst->value = tag;
184}
185
186
187
188/**************************************************************************
189 * skb attributes
190 **************************************************************************/
191
192META_COLLECTOR(int_priority)
193{
194	dst->value = skb->priority;
195}
196
197META_COLLECTOR(int_protocol)
198{
199	/* Let userspace take care of the byte ordering */
200	dst->value = skb->protocol;
201}
202
203META_COLLECTOR(int_pkttype)
204{
205	dst->value = skb->pkt_type;
206}
207
208META_COLLECTOR(int_pktlen)
209{
210	dst->value = skb->len;
211}
212
213META_COLLECTOR(int_datalen)
214{
215	dst->value = skb->data_len;
216}
217
218META_COLLECTOR(int_maclen)
219{
220	dst->value = skb->mac_len;
221}
222
223META_COLLECTOR(int_rxhash)
224{
225	dst->value = skb_get_rxhash(skb);
226}
227
228/**************************************************************************
229 * Netfilter
230 **************************************************************************/
231
232META_COLLECTOR(int_mark)
233{
234	dst->value = skb->mark;
235}
236
237/**************************************************************************
238 * Traffic Control
239 **************************************************************************/
240
241META_COLLECTOR(int_tcindex)
242{
243	dst->value = skb->tc_index;
244}
245
246/**************************************************************************
247 * Routing
248 **************************************************************************/
249
250META_COLLECTOR(int_rtclassid)
251{
252	if (unlikely(skb_dst(skb) == NULL))
253		*err = -1;
254	else
255#ifdef CONFIG_IP_ROUTE_CLASSID
256		dst->value = skb_dst(skb)->tclassid;
257#else
258		dst->value = 0;
259#endif
260}
261
262META_COLLECTOR(int_rtiif)
263{
264	if (unlikely(skb_rtable(skb) == NULL))
265		*err = -1;
266	else
267		dst->value = inet_iif(skb);
268}
269
270/**************************************************************************
271 * Socket Attributes
272 **************************************************************************/
273
274#define SKIP_NONLOCAL(skb)			\
275	if (unlikely(skb->sk == NULL)) {	\
276		*err = -1;			\
277		return;				\
278	}
279
280META_COLLECTOR(int_sk_family)
281{
282	SKIP_NONLOCAL(skb);
283	dst->value = skb->sk->sk_family;
284}
285
286META_COLLECTOR(int_sk_state)
287{
288	SKIP_NONLOCAL(skb);
289	dst->value = skb->sk->sk_state;
290}
291
292META_COLLECTOR(int_sk_reuse)
293{
294	SKIP_NONLOCAL(skb);
295	dst->value = skb->sk->sk_reuse;
296}
297
298META_COLLECTOR(int_sk_bound_if)
299{
300	SKIP_NONLOCAL(skb);
301	/* No error if bound_dev_if is 0, legal userspace check */
302	dst->value = skb->sk->sk_bound_dev_if;
303}
304
305META_COLLECTOR(var_sk_bound_if)
306{
307	SKIP_NONLOCAL(skb);
308
309	if (skb->sk->sk_bound_dev_if == 0) {
310		dst->value = (unsigned long) "any";
311		dst->len = 3;
312	} else {
313		struct net_device *dev;
314
315		rcu_read_lock();
316		dev = dev_get_by_index_rcu(sock_net(skb->sk),
317					   skb->sk->sk_bound_dev_if);
318		*err = var_dev(dev, dst);
319		rcu_read_unlock();
320	}
321}
322
323META_COLLECTOR(int_sk_refcnt)
324{
325	SKIP_NONLOCAL(skb);
326	dst->value = atomic_read(&skb->sk->sk_refcnt);
327}
328
329META_COLLECTOR(int_sk_rcvbuf)
330{
331	SKIP_NONLOCAL(skb);
332	dst->value = skb->sk->sk_rcvbuf;
333}
334
335META_COLLECTOR(int_sk_shutdown)
336{
337	SKIP_NONLOCAL(skb);
338	dst->value = skb->sk->sk_shutdown;
339}
340
341META_COLLECTOR(int_sk_proto)
342{
343	SKIP_NONLOCAL(skb);
344	dst->value = skb->sk->sk_protocol;
345}
346
347META_COLLECTOR(int_sk_type)
348{
349	SKIP_NONLOCAL(skb);
350	dst->value = skb->sk->sk_type;
351}
352
353META_COLLECTOR(int_sk_rmem_alloc)
354{
355	SKIP_NONLOCAL(skb);
356	dst->value = sk_rmem_alloc_get(skb->sk);
357}
358
359META_COLLECTOR(int_sk_wmem_alloc)
360{
361	SKIP_NONLOCAL(skb);
362	dst->value = sk_wmem_alloc_get(skb->sk);
363}
364
365META_COLLECTOR(int_sk_omem_alloc)
366{
367	SKIP_NONLOCAL(skb);
368	dst->value = atomic_read(&skb->sk->sk_omem_alloc);
369}
370
371META_COLLECTOR(int_sk_rcv_qlen)
372{
373	SKIP_NONLOCAL(skb);
374	dst->value = skb->sk->sk_receive_queue.qlen;
375}
376
377META_COLLECTOR(int_sk_snd_qlen)
378{
379	SKIP_NONLOCAL(skb);
380	dst->value = skb->sk->sk_write_queue.qlen;
381}
382
383META_COLLECTOR(int_sk_wmem_queued)
384{
385	SKIP_NONLOCAL(skb);
386	dst->value = skb->sk->sk_wmem_queued;
387}
388
389META_COLLECTOR(int_sk_fwd_alloc)
390{
391	SKIP_NONLOCAL(skb);
392	dst->value = skb->sk->sk_forward_alloc;
393}
394
395META_COLLECTOR(int_sk_sndbuf)
396{
397	SKIP_NONLOCAL(skb);
398	dst->value = skb->sk->sk_sndbuf;
399}
400
401META_COLLECTOR(int_sk_alloc)
402{
403	SKIP_NONLOCAL(skb);
404	dst->value = (__force int) skb->sk->sk_allocation;
405}
406
407META_COLLECTOR(int_sk_hash)
408{
409	SKIP_NONLOCAL(skb);
410	dst->value = skb->sk->sk_hash;
411}
412
413META_COLLECTOR(int_sk_lingertime)
414{
415	SKIP_NONLOCAL(skb);
416	dst->value = skb->sk->sk_lingertime / HZ;
417}
418
419META_COLLECTOR(int_sk_err_qlen)
420{
421	SKIP_NONLOCAL(skb);
422	dst->value = skb->sk->sk_error_queue.qlen;
423}
424
425META_COLLECTOR(int_sk_ack_bl)
426{
427	SKIP_NONLOCAL(skb);
428	dst->value = skb->sk->sk_ack_backlog;
429}
430
431META_COLLECTOR(int_sk_max_ack_bl)
432{
433	SKIP_NONLOCAL(skb);
434	dst->value = skb->sk->sk_max_ack_backlog;
435}
436
437META_COLLECTOR(int_sk_prio)
438{
439	SKIP_NONLOCAL(skb);
440	dst->value = skb->sk->sk_priority;
441}
442
443META_COLLECTOR(int_sk_rcvlowat)
444{
445	SKIP_NONLOCAL(skb);
446	dst->value = skb->sk->sk_rcvlowat;
447}
448
449META_COLLECTOR(int_sk_rcvtimeo)
450{
451	SKIP_NONLOCAL(skb);
452	dst->value = skb->sk->sk_rcvtimeo / HZ;
453}
454
455META_COLLECTOR(int_sk_sndtimeo)
456{
457	SKIP_NONLOCAL(skb);
458	dst->value = skb->sk->sk_sndtimeo / HZ;
459}
460
461META_COLLECTOR(int_sk_sendmsg_off)
462{
463	SKIP_NONLOCAL(skb);
464	dst->value = skb->sk->sk_frag.offset;
465}
466
467META_COLLECTOR(int_sk_write_pend)
468{
469	SKIP_NONLOCAL(skb);
470	dst->value = skb->sk->sk_write_pending;
471}
472
473/**************************************************************************
474 * Meta value collectors assignment table
475 **************************************************************************/
476
477struct meta_ops {
478	void		(*get)(struct sk_buff *, struct tcf_pkt_info *,
479			       struct meta_value *, struct meta_obj *, int *);
480};
481
482#define META_ID(name) TCF_META_ID_##name
483#define META_FUNC(name) { .get = meta_##name }
484
485/* Meta value operations table listing all meta value collectors and
486 * assigns them to a type and meta id. */
487static struct meta_ops __meta_ops[TCF_META_TYPE_MAX + 1][TCF_META_ID_MAX + 1] = {
488	[TCF_META_TYPE_VAR] = {
489		[META_ID(DEV)]			= META_FUNC(var_dev),
490		[META_ID(SK_BOUND_IF)] 		= META_FUNC(var_sk_bound_if),
491	},
492	[TCF_META_TYPE_INT] = {
493		[META_ID(RANDOM)]		= META_FUNC(int_random),
494		[META_ID(LOADAVG_0)]		= META_FUNC(int_loadavg_0),
495		[META_ID(LOADAVG_1)]		= META_FUNC(int_loadavg_1),
496		[META_ID(LOADAVG_2)]		= META_FUNC(int_loadavg_2),
497		[META_ID(DEV)]			= META_FUNC(int_dev),
498		[META_ID(PRIORITY)]		= META_FUNC(int_priority),
499		[META_ID(PROTOCOL)]		= META_FUNC(int_protocol),
500		[META_ID(PKTTYPE)]		= META_FUNC(int_pkttype),
501		[META_ID(PKTLEN)]		= META_FUNC(int_pktlen),
502		[META_ID(DATALEN)]		= META_FUNC(int_datalen),
503		[META_ID(MACLEN)]		= META_FUNC(int_maclen),
504		[META_ID(NFMARK)]		= META_FUNC(int_mark),
505		[META_ID(TCINDEX)]		= META_FUNC(int_tcindex),
506		[META_ID(RTCLASSID)]		= META_FUNC(int_rtclassid),
507		[META_ID(RTIIF)]		= META_FUNC(int_rtiif),
508		[META_ID(SK_FAMILY)]		= META_FUNC(int_sk_family),
509		[META_ID(SK_STATE)]		= META_FUNC(int_sk_state),
510		[META_ID(SK_REUSE)]		= META_FUNC(int_sk_reuse),
511		[META_ID(SK_BOUND_IF)]		= META_FUNC(int_sk_bound_if),
512		[META_ID(SK_REFCNT)]		= META_FUNC(int_sk_refcnt),
513		[META_ID(SK_RCVBUF)]		= META_FUNC(int_sk_rcvbuf),
514		[META_ID(SK_SNDBUF)]		= META_FUNC(int_sk_sndbuf),
515		[META_ID(SK_SHUTDOWN)]		= META_FUNC(int_sk_shutdown),
516		[META_ID(SK_PROTO)]		= META_FUNC(int_sk_proto),
517		[META_ID(SK_TYPE)]		= META_FUNC(int_sk_type),
518		[META_ID(SK_RMEM_ALLOC)]	= META_FUNC(int_sk_rmem_alloc),
519		[META_ID(SK_WMEM_ALLOC)]	= META_FUNC(int_sk_wmem_alloc),
520		[META_ID(SK_OMEM_ALLOC)]	= META_FUNC(int_sk_omem_alloc),
521		[META_ID(SK_WMEM_QUEUED)]	= META_FUNC(int_sk_wmem_queued),
522		[META_ID(SK_RCV_QLEN)]		= META_FUNC(int_sk_rcv_qlen),
523		[META_ID(SK_SND_QLEN)]		= META_FUNC(int_sk_snd_qlen),
524		[META_ID(SK_ERR_QLEN)]		= META_FUNC(int_sk_err_qlen),
525		[META_ID(SK_FORWARD_ALLOCS)]	= META_FUNC(int_sk_fwd_alloc),
526		[META_ID(SK_ALLOCS)]		= META_FUNC(int_sk_alloc),
527		[META_ID(SK_HASH)]		= META_FUNC(int_sk_hash),
528		[META_ID(SK_LINGERTIME)]	= META_FUNC(int_sk_lingertime),
529		[META_ID(SK_ACK_BACKLOG)]	= META_FUNC(int_sk_ack_bl),
530		[META_ID(SK_MAX_ACK_BACKLOG)]	= META_FUNC(int_sk_max_ack_bl),
531		[META_ID(SK_PRIO)]		= META_FUNC(int_sk_prio),
532		[META_ID(SK_RCVLOWAT)]		= META_FUNC(int_sk_rcvlowat),
533		[META_ID(SK_RCVTIMEO)]		= META_FUNC(int_sk_rcvtimeo),
534		[META_ID(SK_SNDTIMEO)]		= META_FUNC(int_sk_sndtimeo),
535		[META_ID(SK_SENDMSG_OFF)]	= META_FUNC(int_sk_sendmsg_off),
536		[META_ID(SK_WRITE_PENDING)]	= META_FUNC(int_sk_write_pend),
537		[META_ID(VLAN_TAG)]		= META_FUNC(int_vlan_tag),
538		[META_ID(RXHASH)]		= META_FUNC(int_rxhash),
539	}
540};
541
542static inline struct meta_ops *meta_ops(struct meta_value *val)
543{
544	return &__meta_ops[meta_type(val)][meta_id(val)];
545}
546
547/**************************************************************************
548 * Type specific operations for TCF_META_TYPE_VAR
549 **************************************************************************/
550
551static int meta_var_compare(struct meta_obj *a, struct meta_obj *b)
552{
553	int r = a->len - b->len;
554
555	if (r == 0)
556		r = memcmp((void *) a->value, (void *) b->value, a->len);
557
558	return r;
559}
560
561static int meta_var_change(struct meta_value *dst, struct nlattr *nla)
562{
563	int len = nla_len(nla);
564
565	dst->val = (unsigned long)kmemdup(nla_data(nla), len, GFP_KERNEL);
566	if (dst->val == 0UL)
567		return -ENOMEM;
568	dst->len = len;
569	return 0;
570}
571
572static void meta_var_destroy(struct meta_value *v)
573{
574	kfree((void *) v->val);
575}
576
577static void meta_var_apply_extras(struct meta_value *v,
578				  struct meta_obj *dst)
579{
580	int shift = v->hdr.shift;
581
582	if (shift && shift < dst->len)
583		dst->len -= shift;
584}
585
586static int meta_var_dump(struct sk_buff *skb, struct meta_value *v, int tlv)
587{
588	if (v->val && v->len &&
589	    nla_put(skb, tlv, v->len, (void *) v->val))
590		goto nla_put_failure;
591	return 0;
592
593nla_put_failure:
594	return -1;
595}
596
597/**************************************************************************
598 * Type specific operations for TCF_META_TYPE_INT
599 **************************************************************************/
600
601static int meta_int_compare(struct meta_obj *a, struct meta_obj *b)
602{
603	/* Let gcc optimize it, the unlikely is not really based on
604	 * some numbers but jump free code for mismatches seems
605	 * more logical. */
606	if (unlikely(a->value == b->value))
607		return 0;
608	else if (a->value < b->value)
609		return -1;
610	else
611		return 1;
612}
613
614static int meta_int_change(struct meta_value *dst, struct nlattr *nla)
615{
616	if (nla_len(nla) >= sizeof(unsigned long)) {
617		dst->val = *(unsigned long *) nla_data(nla);
618		dst->len = sizeof(unsigned long);
619	} else if (nla_len(nla) == sizeof(u32)) {
620		dst->val = nla_get_u32(nla);
621		dst->len = sizeof(u32);
622	} else
623		return -EINVAL;
624
625	return 0;
626}
627
628static void meta_int_apply_extras(struct meta_value *v,
629				  struct meta_obj *dst)
630{
631	if (v->hdr.shift)
632		dst->value >>= v->hdr.shift;
633
634	if (v->val)
635		dst->value &= v->val;
636}
637
638static int meta_int_dump(struct sk_buff *skb, struct meta_value *v, int tlv)
639{
640	if (v->len == sizeof(unsigned long)) {
641		if (nla_put(skb, tlv, sizeof(unsigned long), &v->val))
642			goto nla_put_failure;
643	} else if (v->len == sizeof(u32)) {
644		if (nla_put_u32(skb, tlv, v->val))
645			goto nla_put_failure;
646	}
647
648	return 0;
649
650nla_put_failure:
651	return -1;
652}
653
654/**************************************************************************
655 * Type specific operations table
656 **************************************************************************/
657
658struct meta_type_ops {
659	void	(*destroy)(struct meta_value *);
660	int	(*compare)(struct meta_obj *, struct meta_obj *);
661	int	(*change)(struct meta_value *, struct nlattr *);
662	void	(*apply_extras)(struct meta_value *, struct meta_obj *);
663	int	(*dump)(struct sk_buff *, struct meta_value *, int);
664};
665
666static struct meta_type_ops __meta_type_ops[TCF_META_TYPE_MAX + 1] = {
667	[TCF_META_TYPE_VAR] = {
668		.destroy = meta_var_destroy,
669		.compare = meta_var_compare,
670		.change = meta_var_change,
671		.apply_extras = meta_var_apply_extras,
672		.dump = meta_var_dump
673	},
674	[TCF_META_TYPE_INT] = {
675		.compare = meta_int_compare,
676		.change = meta_int_change,
677		.apply_extras = meta_int_apply_extras,
678		.dump = meta_int_dump
679	}
680};
681
682static inline struct meta_type_ops *meta_type_ops(struct meta_value *v)
683{
684	return &__meta_type_ops[meta_type(v)];
685}
686
687/**************************************************************************
688 * Core
689 **************************************************************************/
690
691static int meta_get(struct sk_buff *skb, struct tcf_pkt_info *info,
692		    struct meta_value *v, struct meta_obj *dst)
693{
694	int err = 0;
695
696	if (meta_id(v) == TCF_META_ID_VALUE) {
697		dst->value = v->val;
698		dst->len = v->len;
699		return 0;
700	}
701
702	meta_ops(v)->get(skb, info, v, dst, &err);
703	if (err < 0)
704		return err;
705
706	if (meta_type_ops(v)->apply_extras)
707		meta_type_ops(v)->apply_extras(v, dst);
708
709	return 0;
710}
711
712static int em_meta_match(struct sk_buff *skb, struct tcf_ematch *m,
713			 struct tcf_pkt_info *info)
714{
715	int r;
716	struct meta_match *meta = (struct meta_match *) m->data;
717	struct meta_obj l_value, r_value;
718
719	if (meta_get(skb, info, &meta->lvalue, &l_value) < 0 ||
720	    meta_get(skb, info, &meta->rvalue, &r_value) < 0)
721		return 0;
722
723	r = meta_type_ops(&meta->lvalue)->compare(&l_value, &r_value);
724
725	switch (meta->lvalue.hdr.op) {
726	case TCF_EM_OPND_EQ:
727		return !r;
728	case TCF_EM_OPND_LT:
729		return r < 0;
730	case TCF_EM_OPND_GT:
731		return r > 0;
732	}
733
734	return 0;
735}
736
737static void meta_delete(struct meta_match *meta)
738{
739	if (meta) {
740		struct meta_type_ops *ops = meta_type_ops(&meta->lvalue);
741
742		if (ops && ops->destroy) {
743			ops->destroy(&meta->lvalue);
744			ops->destroy(&meta->rvalue);
745		}
746	}
747
748	kfree(meta);
749}
750
751static inline int meta_change_data(struct meta_value *dst, struct nlattr *nla)
752{
753	if (nla) {
754		if (nla_len(nla) == 0)
755			return -EINVAL;
756
757		return meta_type_ops(dst)->change(dst, nla);
758	}
759
760	return 0;
761}
762
763static inline int meta_is_supported(struct meta_value *val)
764{
765	return !meta_id(val) || meta_ops(val)->get;
766}
767
768static const struct nla_policy meta_policy[TCA_EM_META_MAX + 1] = {
769	[TCA_EM_META_HDR]	= { .len = sizeof(struct tcf_meta_hdr) },
770};
771
772static int em_meta_change(struct tcf_proto *tp, void *data, int len,
773			  struct tcf_ematch *m)
774{
775	int err;
776	struct nlattr *tb[TCA_EM_META_MAX + 1];
777	struct tcf_meta_hdr *hdr;
778	struct meta_match *meta = NULL;
779
780	err = nla_parse(tb, TCA_EM_META_MAX, data, len, meta_policy);
781	if (err < 0)
782		goto errout;
783
784	err = -EINVAL;
785	if (tb[TCA_EM_META_HDR] == NULL)
786		goto errout;
787	hdr = nla_data(tb[TCA_EM_META_HDR]);
788
789	if (TCF_META_TYPE(hdr->left.kind) != TCF_META_TYPE(hdr->right.kind) ||
790	    TCF_META_TYPE(hdr->left.kind) > TCF_META_TYPE_MAX ||
791	    TCF_META_ID(hdr->left.kind) > TCF_META_ID_MAX ||
792	    TCF_META_ID(hdr->right.kind) > TCF_META_ID_MAX)
793		goto errout;
794
795	meta = kzalloc(sizeof(*meta), GFP_KERNEL);
796	if (meta == NULL)
797		goto errout;
798
799	memcpy(&meta->lvalue.hdr, &hdr->left, sizeof(hdr->left));
800	memcpy(&meta->rvalue.hdr, &hdr->right, sizeof(hdr->right));
801
802	if (!meta_is_supported(&meta->lvalue) ||
803	    !meta_is_supported(&meta->rvalue)) {
804		err = -EOPNOTSUPP;
805		goto errout;
806	}
807
808	if (meta_change_data(&meta->lvalue, tb[TCA_EM_META_LVALUE]) < 0 ||
809	    meta_change_data(&meta->rvalue, tb[TCA_EM_META_RVALUE]) < 0)
810		goto errout;
811
812	m->datalen = sizeof(*meta);
813	m->data = (unsigned long) meta;
814
815	err = 0;
816errout:
817	if (err && meta)
818		meta_delete(meta);
819	return err;
820}
821
822static void em_meta_destroy(struct tcf_proto *tp, struct tcf_ematch *m)
823{
824	if (m)
825		meta_delete((struct meta_match *) m->data);
826}
827
828static int em_meta_dump(struct sk_buff *skb, struct tcf_ematch *em)
829{
830	struct meta_match *meta = (struct meta_match *) em->data;
831	struct tcf_meta_hdr hdr;
832	struct meta_type_ops *ops;
833
834	memset(&hdr, 0, sizeof(hdr));
835	memcpy(&hdr.left, &meta->lvalue.hdr, sizeof(hdr.left));
836	memcpy(&hdr.right, &meta->rvalue.hdr, sizeof(hdr.right));
837
838	if (nla_put(skb, TCA_EM_META_HDR, sizeof(hdr), &hdr))
839		goto nla_put_failure;
840
841	ops = meta_type_ops(&meta->lvalue);
842	if (ops->dump(skb, &meta->lvalue, TCA_EM_META_LVALUE) < 0 ||
843	    ops->dump(skb, &meta->rvalue, TCA_EM_META_RVALUE) < 0)
844		goto nla_put_failure;
845
846	return 0;
847
848nla_put_failure:
849	return -1;
850}
851
852static struct tcf_ematch_ops em_meta_ops = {
853	.kind	  = TCF_EM_META,
854	.change	  = em_meta_change,
855	.match	  = em_meta_match,
856	.destroy  = em_meta_destroy,
857	.dump	  = em_meta_dump,
858	.owner	  = THIS_MODULE,
859	.link	  = LIST_HEAD_INIT(em_meta_ops.link)
860};
861
862static int __init init_em_meta(void)
863{
864	return tcf_em_register(&em_meta_ops);
865}
866
867static void __exit exit_em_meta(void)
868{
869	tcf_em_unregister(&em_meta_ops);
870}
871
872MODULE_LICENSE("GPL");
873
874module_init(init_em_meta);
875module_exit(exit_em_meta);
876
877MODULE_ALIAS_TCF_EMATCH(TCF_EM_META);
878