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
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
|
/*
* net/sched/em_text.c Textsearch ematch
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Authors: Thomas Graf <tgraf@suug.ch>
*/
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/skbuff.h>
#include <linux/textsearch.h>
#include <linux/tc_ematch/tc_em_text.h>
#include <net/pkt_cls.h>
struct text_match {
u16 from_offset;
u16 to_offset;
u8 from_layer;
u8 to_layer;
struct ts_config *config;
};
#define EM_TEXT_PRIV(m) ((struct text_match *) (m)->data)
static int em_text_match(struct sk_buff *skb, struct tcf_ematch *m,
struct tcf_pkt_info *info)
{
struct text_match *tm = EM_TEXT_PRIV(m);
int from, to;
struct ts_state state;
from = tcf_get_base_ptr(skb, tm->from_layer) - skb->data;
from += tm->from_offset;
to = tcf_get_base_ptr(skb, tm->to_layer) - skb->data;
to += tm->to_offset;
return skb_find_text(skb, from, to, tm->config, &state) != UINT_MAX;
}
static int em_text_change(struct tcf_proto *tp, void *data, int len,
struct tcf_ematch *m)
{
struct text_match *tm;
struct tcf_em_text *conf = data;
struct ts_config *ts_conf;
int flags = 0;
if (len < sizeof(*conf) || len < (sizeof(*conf) + conf->pattern_len))
return -EINVAL;
if (conf->from_layer > conf->to_layer)
return -EINVAL;
if (conf->from_layer == conf->to_layer &&
conf->from_offset > conf->to_offset)
return -EINVAL;
retry:
ts_conf = textsearch_prepare(conf->algo, (u8 *) conf + sizeof(*conf),
conf->pattern_len, GFP_KERNEL, flags);
if (flags & TS_AUTOLOAD)
rtnl_lock();
if (IS_ERR(ts_conf)) {
if (PTR_ERR(ts_conf) == -ENOENT && !(flags & TS_AUTOLOAD)) {
rtnl_unlock();
flags |= TS_AUTOLOAD;
goto retry;
} else
return PTR_ERR(ts_conf);
} else if (flags & TS_AUTOLOAD) {
textsearch_destroy(ts_conf);
return -EAGAIN;
}
tm = kmalloc(sizeof(*tm), GFP_KERNEL);
if (tm == NULL) {
textsearch_destroy(ts_conf);
return -ENOBUFS;
}
tm->from_offset = conf->from_offset;
tm->to_offset = conf->to_offset;
tm->from_layer = conf->from_layer;
tm->to_layer = conf->to_layer;
tm->config = ts_conf;
m->datalen = sizeof(*tm);
m->data = (unsigned long) tm;
return 0;
}
static void em_text_destroy(struct tcf_proto *tp, struct tcf_ematch *m)
{
if (EM_TEXT_PRIV(m) && EM_TEXT_PRIV(m)->config)
textsearch_destroy(EM_TEXT_PRIV(m)->config);
}
static int em_text_dump(struct sk_buff *skb, struct tcf_ematch *m)
{
struct text_match *tm = EM_TEXT_PRIV(m);
struct tcf_em_text conf;
strncpy(conf.algo, tm->config->ops->name, sizeof(conf.algo) - 1);
conf.from_offset = tm->from_offset;
conf.to_offset = tm->to_offset;
conf.from_layer = tm->from_layer;
conf.to_layer = tm->to_layer;
conf.pattern_len = textsearch_get_pattern_len(tm->config);
conf.pad = 0;
if (nla_put_nohdr(skb, sizeof(conf), &conf) < 0)
goto nla_put_failure;
if (nla_append(skb, conf.pattern_len,
textsearch_get_pattern(tm->config)) < 0)
goto nla_put_failure;
return 0;
nla_put_failure:
return -1;
}
static struct tcf_ematch_ops em_text_ops = {
.kind = TCF_EM_TEXT,
.change = em_text_change,
.match = em_text_match,
.destroy = em_text_destroy,
.dump = em_text_dump,
.owner = THIS_MODULE,
.link = LIST_HEAD_INIT(em_text_ops.link)
};
static int __init init_em_text(void)
{
return tcf_em_register(&em_text_ops);
}
static void __exit exit_em_text(void)
{
tcf_em_unregister(&em_text_ops);
}
MODULE_LICENSE("GPL");
module_init(init_em_text);
module_exit(exit_em_text);
MODULE_ALIAS_TCF_EMATCH(TCF_EM_TEXT);
|
