1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * net/sched/em_nbyte.c N-Byte ematch
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Authors: Thomas Graf <tgraf@suug.ch>
6*4882a593Smuzhiyun */
7*4882a593Smuzhiyun
8*4882a593Smuzhiyun #include <linux/gfp.h>
9*4882a593Smuzhiyun #include <linux/module.h>
10*4882a593Smuzhiyun #include <linux/types.h>
11*4882a593Smuzhiyun #include <linux/kernel.h>
12*4882a593Smuzhiyun #include <linux/string.h>
13*4882a593Smuzhiyun #include <linux/skbuff.h>
14*4882a593Smuzhiyun #include <linux/tc_ematch/tc_em_nbyte.h>
15*4882a593Smuzhiyun #include <net/pkt_cls.h>
16*4882a593Smuzhiyun
17*4882a593Smuzhiyun struct nbyte_data {
18*4882a593Smuzhiyun struct tcf_em_nbyte hdr;
19*4882a593Smuzhiyun char pattern[];
20*4882a593Smuzhiyun };
21*4882a593Smuzhiyun
em_nbyte_change(struct net * net,void * data,int data_len,struct tcf_ematch * em)22*4882a593Smuzhiyun static int em_nbyte_change(struct net *net, void *data, int data_len,
23*4882a593Smuzhiyun struct tcf_ematch *em)
24*4882a593Smuzhiyun {
25*4882a593Smuzhiyun struct tcf_em_nbyte *nbyte = data;
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun if (data_len < sizeof(*nbyte) ||
28*4882a593Smuzhiyun data_len < (sizeof(*nbyte) + nbyte->len))
29*4882a593Smuzhiyun return -EINVAL;
30*4882a593Smuzhiyun
31*4882a593Smuzhiyun em->datalen = sizeof(*nbyte) + nbyte->len;
32*4882a593Smuzhiyun em->data = (unsigned long)kmemdup(data, em->datalen, GFP_KERNEL);
33*4882a593Smuzhiyun if (em->data == 0UL)
34*4882a593Smuzhiyun return -ENOBUFS;
35*4882a593Smuzhiyun
36*4882a593Smuzhiyun return 0;
37*4882a593Smuzhiyun }
38*4882a593Smuzhiyun
em_nbyte_match(struct sk_buff * skb,struct tcf_ematch * em,struct tcf_pkt_info * info)39*4882a593Smuzhiyun static int em_nbyte_match(struct sk_buff *skb, struct tcf_ematch *em,
40*4882a593Smuzhiyun struct tcf_pkt_info *info)
41*4882a593Smuzhiyun {
42*4882a593Smuzhiyun struct nbyte_data *nbyte = (struct nbyte_data *) em->data;
43*4882a593Smuzhiyun unsigned char *ptr = tcf_get_base_ptr(skb, nbyte->hdr.layer);
44*4882a593Smuzhiyun
45*4882a593Smuzhiyun ptr += nbyte->hdr.off;
46*4882a593Smuzhiyun
47*4882a593Smuzhiyun if (!tcf_valid_offset(skb, ptr, nbyte->hdr.len))
48*4882a593Smuzhiyun return 0;
49*4882a593Smuzhiyun
50*4882a593Smuzhiyun return !memcmp(ptr, nbyte->pattern, nbyte->hdr.len);
51*4882a593Smuzhiyun }
52*4882a593Smuzhiyun
53*4882a593Smuzhiyun static struct tcf_ematch_ops em_nbyte_ops = {
54*4882a593Smuzhiyun .kind = TCF_EM_NBYTE,
55*4882a593Smuzhiyun .change = em_nbyte_change,
56*4882a593Smuzhiyun .match = em_nbyte_match,
57*4882a593Smuzhiyun .owner = THIS_MODULE,
58*4882a593Smuzhiyun .link = LIST_HEAD_INIT(em_nbyte_ops.link)
59*4882a593Smuzhiyun };
60*4882a593Smuzhiyun
init_em_nbyte(void)61*4882a593Smuzhiyun static int __init init_em_nbyte(void)
62*4882a593Smuzhiyun {
63*4882a593Smuzhiyun return tcf_em_register(&em_nbyte_ops);
64*4882a593Smuzhiyun }
65*4882a593Smuzhiyun
exit_em_nbyte(void)66*4882a593Smuzhiyun static void __exit exit_em_nbyte(void)
67*4882a593Smuzhiyun {
68*4882a593Smuzhiyun tcf_em_unregister(&em_nbyte_ops);
69*4882a593Smuzhiyun }
70*4882a593Smuzhiyun
71*4882a593Smuzhiyun MODULE_LICENSE("GPL");
72*4882a593Smuzhiyun
73*4882a593Smuzhiyun module_init(init_em_nbyte);
74*4882a593Smuzhiyun module_exit(exit_em_nbyte);
75*4882a593Smuzhiyun
76*4882a593Smuzhiyun MODULE_ALIAS_TCF_EMATCH(TCF_EM_NBYTE);
77