netfilter: nf_log: fix sleeping function called from invalid context
[linux-2.6.git] / net / netfilter / xt_string.c
1 /* String matching match for iptables
2  *
3  * (C) 2005 Pablo Neira Ayuso <pablo@eurodev.net>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  */
9
10 #include <linux/init.h>
11 #include <linux/module.h>
12 #include <linux/kernel.h>
13 #include <linux/skbuff.h>
14 #include <linux/netfilter/x_tables.h>
15 #include <linux/netfilter/xt_string.h>
16 #include <linux/textsearch.h>
17
18 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@eurodev.net>");
19 MODULE_DESCRIPTION("Xtables: string-based matching");
20 MODULE_LICENSE("GPL");
21 MODULE_ALIAS("ipt_string");
22 MODULE_ALIAS("ip6t_string");
23
24 static bool
25 string_mt(const struct sk_buff *skb, const struct xt_match_param *par)
26 {
27         const struct xt_string_info *conf = par->matchinfo;
28         struct ts_state state;
29         int invert;
30
31         memset(&state, 0, sizeof(struct ts_state));
32
33         invert = (par->match->revision == 0 ? conf->u.v0.invert :
34                                     conf->u.v1.flags & XT_STRING_FLAG_INVERT);
35
36         return (skb_find_text((struct sk_buff *)skb, conf->from_offset,
37                              conf->to_offset, conf->config, &state)
38                              != UINT_MAX) ^ invert;
39 }
40
41 #define STRING_TEXT_PRIV(m) ((struct xt_string_info *)(m))
42
43 static bool string_mt_check(const struct xt_mtchk_param *par)
44 {
45         struct xt_string_info *conf = par->matchinfo;
46         struct ts_config *ts_conf;
47         int flags = TS_AUTOLOAD;
48
49         /* Damn, can't handle this case properly with iptables... */
50         if (conf->from_offset > conf->to_offset)
51                 return false;
52         if (conf->algo[XT_STRING_MAX_ALGO_NAME_SIZE - 1] != '\0')
53                 return false;
54         if (conf->patlen > XT_STRING_MAX_PATTERN_SIZE)
55                 return false;
56         if (par->match->revision == 1) {
57                 if (conf->u.v1.flags &
58                     ~(XT_STRING_FLAG_IGNORECASE | XT_STRING_FLAG_INVERT))
59                         return false;
60                 if (conf->u.v1.flags & XT_STRING_FLAG_IGNORECASE)
61                         flags |= TS_IGNORECASE;
62         }
63         ts_conf = textsearch_prepare(conf->algo, conf->pattern, conf->patlen,
64                                      GFP_KERNEL, flags);
65         if (IS_ERR(ts_conf))
66                 return false;
67
68         conf->config = ts_conf;
69
70         return true;
71 }
72
73 static void string_mt_destroy(const struct xt_mtdtor_param *par)
74 {
75         textsearch_destroy(STRING_TEXT_PRIV(par->matchinfo)->config);
76 }
77
78 static struct xt_match xt_string_mt_reg[] __read_mostly = {
79         {
80                 .name           = "string",
81                 .revision       = 0,
82                 .family         = NFPROTO_UNSPEC,
83                 .checkentry     = string_mt_check,
84                 .match          = string_mt,
85                 .destroy        = string_mt_destroy,
86                 .matchsize      = sizeof(struct xt_string_info),
87                 .me             = THIS_MODULE
88         },
89         {
90                 .name           = "string",
91                 .revision       = 1,
92                 .family         = NFPROTO_UNSPEC,
93                 .checkentry     = string_mt_check,
94                 .match          = string_mt,
95                 .destroy        = string_mt_destroy,
96                 .matchsize      = sizeof(struct xt_string_info),
97                 .me             = THIS_MODULE
98         },
99 };
100
101 static int __init string_mt_init(void)
102 {
103         return xt_register_matches(xt_string_mt_reg,
104                                    ARRAY_SIZE(xt_string_mt_reg));
105 }
106
107 static void __exit string_mt_exit(void)
108 {
109         xt_unregister_matches(xt_string_mt_reg, ARRAY_SIZE(xt_string_mt_reg));
110 }
111
112 module_init(string_mt_init);
113 module_exit(string_mt_exit);