2e4e6a17af
This monster-patch tries to do the best job for unifying the data
structures and backend interfaces for the three evil clones ip_tables,
ip6_tables and arp_tables. In an ideal world we would never have
allowed this kind of copy+paste programming... but well, our world
isn't (yet?) ideal.
o introduce a new x_tables module
o {ip,arp,ip6}_tables depend on this x_tables module
o registration functions for tables, matches and targets are only
wrappers around x_tables provided functions
o all matches/targets that are used from ip_tables and ip6_tables
are now implemented as xt_FOOBAR.c files and provide module aliases
to ipt_FOOBAR and ip6t_FOOBAR
o header files for xt_matches are in include/linux/netfilter/,
include/linux/netfilter_{ipv4,ipv6} contains compatibility wrappers
around the xt_FOOBAR.h headers
Based on this patchset we're going to further unify the code,
gradually getting rid of all the layer 3 specific assumptions.
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
112 lines
2.6 KiB
C
112 lines
2.6 KiB
C
/* String matching match for iptables
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*
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* (C) 2005 Pablo Neira Ayuso <pablo@eurodev.net>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/skbuff.h>
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#include <linux/netfilter/x_tables.h>
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#include <linux/netfilter/xt_string.h>
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#include <linux/textsearch.h>
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MODULE_AUTHOR("Pablo Neira Ayuso <pablo@eurodev.net>");
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MODULE_DESCRIPTION("IP tables string match module");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("ipt_string");
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MODULE_ALIAS("ip6t_string");
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static int match(const struct sk_buff *skb,
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const struct net_device *in,
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const struct net_device *out,
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const void *matchinfo,
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int offset,
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unsigned int protoff,
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int *hotdrop)
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{
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struct ts_state state;
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struct xt_string_info *conf = (struct xt_string_info *) matchinfo;
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memset(&state, 0, sizeof(struct ts_state));
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return (skb_find_text((struct sk_buff *)skb, conf->from_offset,
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conf->to_offset, conf->config, &state)
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!= UINT_MAX) && !conf->invert;
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}
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#define STRING_TEXT_PRIV(m) ((struct xt_string_info *) m)
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static int checkentry(const char *tablename,
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const void *ip,
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void *matchinfo,
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unsigned int matchsize,
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unsigned int hook_mask)
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{
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struct xt_string_info *conf = matchinfo;
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struct ts_config *ts_conf;
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if (matchsize != XT_ALIGN(sizeof(struct xt_string_info)))
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return 0;
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/* Damn, can't handle this case properly with iptables... */
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if (conf->from_offset > conf->to_offset)
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return 0;
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ts_conf = textsearch_prepare(conf->algo, conf->pattern, conf->patlen,
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GFP_KERNEL, TS_AUTOLOAD);
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if (IS_ERR(ts_conf))
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return 0;
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conf->config = ts_conf;
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return 1;
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}
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static void destroy(void *matchinfo, unsigned int matchsize)
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{
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textsearch_destroy(STRING_TEXT_PRIV(matchinfo)->config);
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}
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static struct xt_match string_match = {
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.name = "string",
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.match = match,
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.checkentry = checkentry,
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.destroy = destroy,
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.me = THIS_MODULE
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};
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static struct xt_match string6_match = {
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.name = "string",
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.match = match,
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.checkentry = checkentry,
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.destroy = destroy,
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.me = THIS_MODULE
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};
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static int __init init(void)
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{
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int ret;
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ret = xt_register_match(AF_INET, &string_match);
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if (ret)
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return ret;
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ret = xt_register_match(AF_INET6, &string6_match);
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if (ret)
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xt_unregister_match(AF_INET, &string_match);
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return ret;
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}
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static void __exit fini(void)
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{
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xt_unregister_match(AF_INET, &string_match);
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xt_unregister_match(AF_INET6, &string6_match);
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}
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module_init(init);
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module_exit(fini);
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