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

 1// SPDX-License-Identifier: GPL-2.0-or-later
 2/*
 3 * net/sched/em_nbyte.c	N-Byte ematch
 4 *
 
 
 
 
 
 5 * Authors:	Thomas Graf <tgraf@suug.ch>
 6 */
 7
 8#include <linux/gfp.h>
 9#include <linux/module.h>
10#include <linux/types.h>
11#include <linux/kernel.h>
12#include <linux/string.h>
13#include <linux/skbuff.h>
14#include <linux/tc_ematch/tc_em_nbyte.h>
15#include <net/pkt_cls.h>
16
17struct nbyte_data {
18	struct tcf_em_nbyte	hdr;
19	char			pattern[0];
20};
21
22static int em_nbyte_change(struct net *net, void *data, int data_len,
23			   struct tcf_ematch *em)
24{
25	struct tcf_em_nbyte *nbyte = data;
26
27	if (data_len < sizeof(*nbyte) ||
28	    data_len < (sizeof(*nbyte) + nbyte->len))
29		return -EINVAL;
30
31	em->datalen = sizeof(*nbyte) + nbyte->len;
32	em->data = (unsigned long)kmemdup(data, em->datalen, GFP_KERNEL);
33	if (em->data == 0UL)
34		return -ENOBUFS;
35
36	return 0;
37}
38
39static int em_nbyte_match(struct sk_buff *skb, struct tcf_ematch *em,
40			  struct tcf_pkt_info *info)
41{
42	struct nbyte_data *nbyte = (struct nbyte_data *) em->data;
43	unsigned char *ptr = tcf_get_base_ptr(skb, nbyte->hdr.layer);
44
45	ptr += nbyte->hdr.off;
46
47	if (!tcf_valid_offset(skb, ptr, nbyte->hdr.len))
48		return 0;
49
50	return !memcmp(ptr, nbyte->pattern, nbyte->hdr.len);
51}
52
53static struct tcf_ematch_ops em_nbyte_ops = {
54	.kind	  = TCF_EM_NBYTE,
55	.change	  = em_nbyte_change,
56	.match	  = em_nbyte_match,
57	.owner	  = THIS_MODULE,
58	.link	  = LIST_HEAD_INIT(em_nbyte_ops.link)
59};
60
61static int __init init_em_nbyte(void)
62{
63	return tcf_em_register(&em_nbyte_ops);
64}
65
66static void __exit exit_em_nbyte(void)
67{
68	tcf_em_unregister(&em_nbyte_ops);
69}
70
71MODULE_LICENSE("GPL");
72
73module_init(init_em_nbyte);
74module_exit(exit_em_nbyte);
75
76MODULE_ALIAS_TCF_EMATCH(TCF_EM_NBYTE);