1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * net/sched/em_u32.c U32 Ematch
4 *
5 * Authors: Thomas Graf <tgraf@suug.ch>
6 * Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
7 *
8 * Based on net/sched/cls_u32.c
9 */
10
11 #include <linux/module.h>
12 #include <linux/types.h>
13 #include <linux/kernel.h>
14 #include <linux/skbuff.h>
15 #include <net/pkt_cls.h>
16
17 static int em_u32_match(struct sk_buff *skb, struct tcf_ematch *em,
18 struct tcf_pkt_info *info)
19 {
20 struct tc_u32_key *key = (struct tc_u32_key *) em->data;
21 const unsigned char *ptr = skb_network_header(skb);
22
23 if (info) {
24 if (info->ptr)
25 ptr = info->ptr;
26 ptr += (info->nexthdr & key->offmask);
27 }
28
29 ptr += key->off;
30
31 if (!tcf_valid_offset(skb, ptr, sizeof(u32)))
32 return 0;
33
34 return !(((*(__be32 *) ptr) ^ key->val) & key->mask);
35 }
36
37 static struct tcf_ematch_ops em_u32_ops = {
38 .kind = TCF_EM_U32,
39 .datalen = sizeof(struct tc_u32_key),
40 .match = em_u32_match,
41 .owner = THIS_MODULE,
42 .link = LIST_HEAD_INIT(em_u32_ops.link)
43 };
44
45 static int __init init_em_u32(void)
46 {
47 return tcf_em_register(&em_u32_ops);
48 }
49
50 static void __exit exit_em_u32(void)
51 {
52 tcf_em_unregister(&em_u32_ops);
53 }
54
55 MODULE_DESCRIPTION("ematch skb classifier using 32 bit chunks of data");
56 MODULE_LICENSE("GPL");
57
58 module_init(init_em_u32);
59 module_exit(exit_em_u32);
60
61 MODULE_ALIAS_TCF_EMATCH(TCF_EM_U32);
62
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