blob: 77beabc91fa37107d662bd837a448a3d23cb944f [file] [log] [blame]
Thomas Grafd675c982005-06-23 21:00:58 -07001/*
2 * net/sched/em_text.c Textsearch 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/textsearch.h>
20#include <linux/tc_ematch/tc_em_text.h>
21#include <net/pkt_cls.h>
22
23struct text_match
24{
25 u16 from_offset;
26 u16 to_offset;
27 u8 from_layer;
28 u8 to_layer;
29 struct ts_config *config;
30};
31
32#define EM_TEXT_PRIV(m) ((struct text_match *) (m)->data)
33
34static int em_text_match(struct sk_buff *skb, struct tcf_ematch *m,
35 struct tcf_pkt_info *info)
36{
37 struct text_match *tm = EM_TEXT_PRIV(m);
38 int from, to;
39 struct ts_state state;
40
41 from = tcf_get_base_ptr(skb, tm->from_layer) - skb->data;
42 from += tm->from_offset;
43
44 to = tcf_get_base_ptr(skb, tm->to_layer) - skb->data;
45 to += tm->to_offset;
46
47 return skb_find_text(skb, from, to, tm->config, &state) != UINT_MAX;
48}
49
50static int em_text_change(struct tcf_proto *tp, void *data, int len,
51 struct tcf_ematch *m)
52{
53 struct text_match *tm;
54 struct tcf_em_text *conf = data;
55 struct ts_config *ts_conf;
56 int flags = 0;
57
Thomas Grafd675c982005-06-23 21:00:58 -070058 if (len < sizeof(*conf) || len < (sizeof(*conf) + conf->pattern_len))
59 return -EINVAL;
60
61 if (conf->from_layer > conf->to_layer)
62 return -EINVAL;
63
64 if (conf->from_layer == conf->to_layer &&
65 conf->from_offset > conf->to_offset)
66 return -EINVAL;
67
68retry:
69 ts_conf = textsearch_prepare(conf->algo, (u8 *) conf + sizeof(*conf),
70 conf->pattern_len, GFP_KERNEL, flags);
71
72 if (flags & TS_AUTOLOAD)
73 rtnl_lock();
74
75 if (IS_ERR(ts_conf)) {
76 if (PTR_ERR(ts_conf) == -ENOENT && !(flags & TS_AUTOLOAD)) {
77 rtnl_unlock();
78 flags |= TS_AUTOLOAD;
79 goto retry;
80 } else
81 return PTR_ERR(ts_conf);
82 } else if (flags & TS_AUTOLOAD) {
83 textsearch_destroy(ts_conf);
84 return -EAGAIN;
85 }
86
87 tm = kmalloc(sizeof(*tm), GFP_KERNEL);
88 if (tm == NULL) {
89 textsearch_destroy(ts_conf);
90 return -ENOBUFS;
91 }
92
93 tm->from_offset = conf->from_offset;
94 tm->to_offset = conf->to_offset;
95 tm->from_layer = conf->from_layer;
96 tm->to_layer = conf->to_layer;
97 tm->config = ts_conf;
98
99 m->datalen = sizeof(*tm);
100 m->data = (unsigned long) tm;
101
102 return 0;
103}
104
105static void em_text_destroy(struct tcf_proto *tp, struct tcf_ematch *m)
106{
107 textsearch_destroy(EM_TEXT_PRIV(m)->config);
108}
109
110static int em_text_dump(struct sk_buff *skb, struct tcf_ematch *m)
111{
112 struct text_match *tm = EM_TEXT_PRIV(m);
113 struct tcf_em_text conf;
114
115 strncpy(conf.algo, tm->config->ops->name, sizeof(conf.algo) - 1);
116 conf.from_offset = tm->from_offset;
117 conf.to_offset = tm->to_offset;
118 conf.from_layer = tm->from_layer;
119 conf.to_layer = tm->to_layer;
120 conf.pattern_len = textsearch_get_pattern_len(tm->config);
121 conf.pad = 0;
122
123 RTA_PUT_NOHDR(skb, sizeof(conf), &conf);
124 RTA_APPEND(skb, conf.pattern_len, textsearch_get_pattern(tm->config));
125 return 0;
126
127rtattr_failure:
128 return -1;
129}
130
131static struct tcf_ematch_ops em_text_ops = {
132 .kind = TCF_EM_TEXT,
133 .change = em_text_change,
134 .match = em_text_match,
135 .destroy = em_text_destroy,
136 .dump = em_text_dump,
137 .owner = THIS_MODULE,
138 .link = LIST_HEAD_INIT(em_text_ops.link)
139};
140
141static int __init init_em_text(void)
142{
143 return tcf_em_register(&em_text_ops);
144}
145
146static void __exit exit_em_text(void)
147{
148 tcf_em_unregister(&em_text_ops);
149}
150
151MODULE_LICENSE("GPL");
152
153module_init(init_em_text);
154module_exit(exit_em_text);