Commit | Line | Data |
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1da177e4 LT |
1 | /* |
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 | ||
12 | #include <linux/config.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/types.h> | |
15 | #include <linux/kernel.h> | |
16 | #include <linux/sched.h> | |
17 | #include <linux/string.h> | |
18 | #include <linux/skbuff.h> | |
19 | #include <linux/tc_ematch/tc_em_nbyte.h> | |
20 | #include <net/pkt_cls.h> | |
21 | ||
22 | struct nbyte_data | |
23 | { | |
24 | struct tcf_em_nbyte hdr; | |
25 | char pattern[0]; | |
26 | }; | |
27 | ||
28 | static int em_nbyte_change(struct tcf_proto *tp, void *data, int data_len, | |
29 | struct tcf_ematch *em) | |
30 | { | |
31 | struct tcf_em_nbyte *nbyte = data; | |
32 | ||
33 | if (data_len < sizeof(*nbyte) || | |
34 | data_len < (sizeof(*nbyte) + nbyte->len)) | |
35 | return -EINVAL; | |
36 | ||
37 | em->datalen = sizeof(*nbyte) + nbyte->len; | |
38 | em->data = (unsigned long) kmalloc(em->datalen, GFP_KERNEL); | |
39 | if (em->data == 0UL) | |
40 | return -ENOBUFS; | |
41 | ||
42 | memcpy((void *) em->data, data, em->datalen); | |
43 | ||
44 | return 0; | |
45 | } | |
46 | ||
47 | static int em_nbyte_match(struct sk_buff *skb, struct tcf_ematch *em, | |
48 | struct tcf_pkt_info *info) | |
49 | { | |
50 | struct nbyte_data *nbyte = (struct nbyte_data *) em->data; | |
51 | unsigned char *ptr = tcf_get_base_ptr(skb, nbyte->hdr.layer); | |
52 | ||
53 | ptr += nbyte->hdr.off; | |
54 | ||
55 | if (!tcf_valid_offset(skb, ptr, nbyte->hdr.len)) | |
56 | return 0; | |
57 | ||
58 | return !memcmp(ptr + nbyte->hdr.off, nbyte->pattern, nbyte->hdr.len); | |
59 | } | |
60 | ||
61 | static struct tcf_ematch_ops em_nbyte_ops = { | |
62 | .kind = TCF_EM_NBYTE, | |
63 | .change = em_nbyte_change, | |
64 | .match = em_nbyte_match, | |
65 | .owner = THIS_MODULE, | |
66 | .link = LIST_HEAD_INIT(em_nbyte_ops.link) | |
67 | }; | |
68 | ||
69 | static int __init init_em_nbyte(void) | |
70 | { | |
71 | return tcf_em_register(&em_nbyte_ops); | |
72 | } | |
73 | ||
74 | static void __exit exit_em_nbyte(void) | |
75 | { | |
76 | tcf_em_unregister(&em_nbyte_ops); | |
77 | } | |
78 | ||
79 | MODULE_LICENSE("GPL"); | |
80 | ||
81 | module_init(init_em_nbyte); | |
82 | module_exit(exit_em_nbyte); |