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- /* Kernel module to match connection tracking information. */
- /* (C) 1999-2001 Paul `Rusty' Russell
- * (C) 2002-2005 Netfilter Core Team <coreteam@netfilter.org>
- *
- * 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/module.h>
- #include <linux/skbuff.h>
- #include <net/netfilter/nf_conntrack_compat.h>
- #include <linux/netfilter/x_tables.h>
- #include <linux/netfilter/xt_state.h>
- MODULE_LICENSE("GPL");
- MODULE_AUTHOR("Rusty Russell <rusty@rustcorp.com.au>");
- MODULE_DESCRIPTION("ip[6]_tables connection tracking state match module");
- MODULE_ALIAS("ipt_state");
- MODULE_ALIAS("ip6t_state");
- static int
- match(const struct sk_buff *skb,
- const struct net_device *in,
- const struct net_device *out,
- const struct xt_match *match,
- const void *matchinfo,
- int offset,
- unsigned int protoff,
- int *hotdrop)
- {
- const struct xt_state_info *sinfo = matchinfo;
- enum ip_conntrack_info ctinfo;
- unsigned int statebit;
- if (nf_ct_is_untracked(skb))
- statebit = XT_STATE_UNTRACKED;
- else if (!nf_ct_get_ctinfo(skb, &ctinfo))
- statebit = XT_STATE_INVALID;
- else
- statebit = XT_STATE_BIT(ctinfo);
- return (sinfo->statemask & statebit);
- }
- static int check(const char *tablename,
- const void *inf,
- const struct xt_match *match,
- void *matchinfo,
- unsigned int hook_mask)
- {
- if (nf_ct_l3proto_try_module_get(match->family) < 0) {
- printk(KERN_WARNING "can't load conntrack support for "
- "proto=%d\n", match->family);
- return 0;
- }
- return 1;
- }
- static void
- destroy(const struct xt_match *match, void *matchinfo)
- {
- nf_ct_l3proto_module_put(match->family);
- }
- static struct xt_match xt_state_match[] = {
- {
- .name = "state",
- .family = AF_INET,
- .checkentry = check,
- .match = match,
- .destroy = destroy,
- .matchsize = sizeof(struct xt_state_info),
- .me = THIS_MODULE,
- },
- {
- .name = "state",
- .family = AF_INET6,
- .checkentry = check,
- .match = match,
- .destroy = destroy,
- .matchsize = sizeof(struct xt_state_info),
- .me = THIS_MODULE,
- },
- };
- static int __init xt_state_init(void)
- {
- return xt_register_matches(xt_state_match, ARRAY_SIZE(xt_state_match));
- }
- static void __exit xt_state_fini(void)
- {
- xt_unregister_matches(xt_state_match, ARRAY_SIZE(xt_state_match));
- }
- module_init(xt_state_init);
- module_exit(xt_state_fini);
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