blob: 64b637f18bc7d40509bf5c9f7679cfbc2922af1c (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
|
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* net/sched/em_cmp.c Simple packet data comparison ematch
*
* Authors: Thomas Graf <tgraf@suug.ch>
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/tc_ematch/tc_em_cmp.h>
#include <linux/unaligned.h>
#include <net/pkt_cls.h>
static inline int cmp_needs_transformation(struct tcf_em_cmp *cmp)
{
return unlikely(cmp->flags & TCF_EM_CMP_TRANS);
}
static int em_cmp_match(struct sk_buff *skb, struct tcf_ematch *em,
struct tcf_pkt_info *info)
{
struct tcf_em_cmp *cmp = (struct tcf_em_cmp *) em->data;
unsigned char *ptr = tcf_get_base_ptr(skb, cmp->layer) + cmp->off;
u32 val = 0;
if (!tcf_valid_offset(skb, ptr, cmp->align))
return 0;
switch (cmp->align) {
case TCF_EM_ALIGN_U8:
val = *ptr;
break;
case TCF_EM_ALIGN_U16:
val = get_unaligned_be16(ptr);
if (cmp_needs_transformation(cmp))
val = be16_to_cpu(val);
break;
case TCF_EM_ALIGN_U32:
/* Worth checking boundaries? The branching seems
* to get worse. Visit again.
*/
val = get_unaligned_be32(ptr);
if (cmp_needs_transformation(cmp))
val = be32_to_cpu(val);
break;
default:
return 0;
}
if (cmp->mask)
val &= cmp->mask;
switch (cmp->opnd) {
case TCF_EM_OPND_EQ:
return val == cmp->val;
case TCF_EM_OPND_LT:
return val < cmp->val;
case TCF_EM_OPND_GT:
return val > cmp->val;
}
return 0;
}
static struct tcf_ematch_ops em_cmp_ops = {
.kind = TCF_EM_CMP,
.datalen = sizeof(struct tcf_em_cmp),
.match = em_cmp_match,
.owner = THIS_MODULE,
.link = LIST_HEAD_INIT(em_cmp_ops.link)
};
static int __init init_em_cmp(void)
{
return tcf_em_register(&em_cmp_ops);
}
static void __exit exit_em_cmp(void)
{
tcf_em_unregister(&em_cmp_ops);
}
MODULE_DESCRIPTION("ematch classifier for basic data types(8/16/32 bit) against skb data");
MODULE_LICENSE("GPL");
module_init(init_em_cmp);
module_exit(exit_em_cmp);
MODULE_ALIAS_TCF_EMATCH(TCF_EM_CMP);
|
