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