blob: 005db409be645a45abfd82f7694602874bc5b3ba [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * net/sched/em_nbyte.c N-Byte 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/module.h>
13#include <linux/types.h>
14#include <linux/kernel.h>
15#include <linux/sched.h>
16#include <linux/string.h>
17#include <linux/skbuff.h>
18#include <linux/tc_ematch/tc_em_nbyte.h>
19#include <net/pkt_cls.h>
20
21struct nbyte_data
22{
23 struct tcf_em_nbyte hdr;
24 char pattern[0];
25};
26
27static int em_nbyte_change(struct tcf_proto *tp, void *data, int data_len,
28 struct tcf_ematch *em)
29{
30 struct tcf_em_nbyte *nbyte = data;
31
32 if (data_len < sizeof(*nbyte) ||
33 data_len < (sizeof(*nbyte) + nbyte->len))
34 return -EINVAL;
35
36 em->datalen = sizeof(*nbyte) + nbyte->len;
Arnaldo Carvalho de Meloc7b1b242006-11-21 01:19:40 -020037 em->data = (unsigned long)kmemdup(data, em->datalen, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070038 if (em->data == 0UL)
39 return -ENOBUFS;
40
Linus Torvalds1da177e2005-04-16 15:20:36 -070041 return 0;
42}
43
44static int em_nbyte_match(struct sk_buff *skb, struct tcf_ematch *em,
45 struct tcf_pkt_info *info)
46{
47 struct nbyte_data *nbyte = (struct nbyte_data *) em->data;
48 unsigned char *ptr = tcf_get_base_ptr(skb, nbyte->hdr.layer);
49
50 ptr += nbyte->hdr.off;
51
52 if (!tcf_valid_offset(skb, ptr, nbyte->hdr.len))
53 return 0;
54
55 return !memcmp(ptr + nbyte->hdr.off, nbyte->pattern, nbyte->hdr.len);
56}
57
58static struct tcf_ematch_ops em_nbyte_ops = {
59 .kind = TCF_EM_NBYTE,
60 .change = em_nbyte_change,
61 .match = em_nbyte_match,
62 .owner = THIS_MODULE,
63 .link = LIST_HEAD_INIT(em_nbyte_ops.link)
64};
65
66static int __init init_em_nbyte(void)
67{
68 return tcf_em_register(&em_nbyte_ops);
69}
70
71static void __exit exit_em_nbyte(void)
72{
73 tcf_em_unregister(&em_nbyte_ops);
74}
75
76MODULE_LICENSE("GPL");
77
78module_init(init_em_nbyte);
79module_exit(exit_em_nbyte);