Blame view
net/netfilter/xt_string.c
2.57 KB
81f7e3824 Initial Release, ... |
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 |
/* String matching match for iptables * * (C) 2005 Pablo Neira Ayuso <pablo@eurodev.net> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/gfp.h> #include <linux/init.h> #include <linux/module.h> #include <linux/kernel.h> #include <linux/skbuff.h> #include <linux/netfilter/x_tables.h> #include <linux/netfilter/xt_string.h> #include <linux/textsearch.h> MODULE_AUTHOR("Pablo Neira Ayuso <pablo@eurodev.net>"); MODULE_DESCRIPTION("Xtables: string-based matching"); MODULE_LICENSE("GPL"); MODULE_ALIAS("ipt_string"); MODULE_ALIAS("ip6t_string"); static bool string_mt(const struct sk_buff *skb, struct xt_action_param *par) { const struct xt_string_info *conf = par->matchinfo; bool invert; invert = conf->u.v1.flags & XT_STRING_FLAG_INVERT; return (skb_find_text((struct sk_buff *)skb, conf->from_offset, conf->to_offset, conf->config) != UINT_MAX) ^ invert; } #define STRING_TEXT_PRIV(m) ((struct xt_string_info *)(m)) static int string_mt_check(const struct xt_mtchk_param *par) { struct xt_string_info *conf = par->matchinfo; struct ts_config *ts_conf; int flags = TS_AUTOLOAD; /* Damn, can't handle this case properly with iptables... */ if (conf->from_offset > conf->to_offset) return -EINVAL; if (conf->algo[XT_STRING_MAX_ALGO_NAME_SIZE - 1] != '\0') return -EINVAL; if (conf->patlen > XT_STRING_MAX_PATTERN_SIZE) return -EINVAL; if (conf->u.v1.flags & ~(XT_STRING_FLAG_IGNORECASE | XT_STRING_FLAG_INVERT)) return -EINVAL; if (conf->u.v1.flags & XT_STRING_FLAG_IGNORECASE) flags |= TS_IGNORECASE; ts_conf = textsearch_prepare(conf->algo, conf->pattern, conf->patlen, GFP_KERNEL, flags); if (IS_ERR(ts_conf)) return PTR_ERR(ts_conf); conf->config = ts_conf; return 0; } static void string_mt_destroy(const struct xt_mtdtor_param *par) { textsearch_destroy(STRING_TEXT_PRIV(par->matchinfo)->config); } static struct xt_match xt_string_mt_reg __read_mostly = { .name = "string", .revision = 1, .family = NFPROTO_UNSPEC, .checkentry = string_mt_check, .match = string_mt, .destroy = string_mt_destroy, .matchsize = sizeof(struct xt_string_info), .usersize = offsetof(struct xt_string_info, config), .me = THIS_MODULE, }; static int __init string_mt_init(void) { return xt_register_match(&xt_string_mt_reg); } static void __exit string_mt_exit(void) { xt_unregister_match(&xt_string_mt_reg); } module_init(string_mt_init); module_exit(string_mt_exit); |