1/*
2 * net/sched/em_u32.c	U32 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 *		Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
11 *
12 * Based on net/sched/cls_u32.c
13 */
14
15#include <linux/module.h>
16#include <linux/types.h>
17#include <linux/kernel.h>
18#include <linux/skbuff.h>
19#include <net/pkt_cls.h>
20
21static int em_u32_match(struct sk_buff *skb, struct tcf_ematch *em,
22			struct tcf_pkt_info *info)
23{
24	struct tc_u32_key *key = (struct tc_u32_key *) em->data;
25	const unsigned char *ptr = skb_network_header(skb);
26
27	if (info) {
28		if (info->ptr)
29			ptr = info->ptr;
30		ptr += (info->nexthdr & key->offmask);
31	}
32
33	ptr += key->off;
34
35	if (!tcf_valid_offset(skb, ptr, sizeof(u32)))
36		return 0;
37
38	return !(((*(u32*) ptr)  ^ key->val) & key->mask);
39}
40
41static struct tcf_ematch_ops em_u32_ops = {
42	.kind	  = TCF_EM_U32,
43	.datalen  = sizeof(struct tc_u32_key),
44	.match	  = em_u32_match,
45	.owner	  = THIS_MODULE,
46	.link	  = LIST_HEAD_INIT(em_u32_ops.link)
47};
48
49static int __init init_em_u32(void)
50{
51	return tcf_em_register(&em_u32_ops);
52}
53
54static void __exit exit_em_u32(void)
55{
56	tcf_em_unregister(&em_u32_ops);
57}
58
59MODULE_LICENSE("GPL");
60
61module_init(init_em_u32);
62module_exit(exit_em_u32);
63