f7108a20de
The function signatures for Xtables extensions have grown over time. It involves a lot of typing/replication, and also a bit of stack space even if they are not used. Realize an NFWS2008 idea and pack them into structs. The skb remains outside of the struct so gcc can continue to apply its optimizations. This patch does this for match extensions' match functions. A few ambiguities have also been addressed. The "offset" parameter for example has been renamed to "fragoff" (there are so many different offsets already) and "protoff" to "thoff" (there is more than just one protocol here, so clarify). Signed-off-by: Jan Engelhardt <jengelh@medozas.de> Signed-off-by: Patrick McHardy <kaber@trash.net>
91 lines
2.3 KiB
C
91 lines
2.3 KiB
C
/* Kernel module to match connection tracking information. */
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/* (C) 1999-2001 Paul `Rusty' Russell
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* (C) 2002-2005 Netfilter Core Team <coreteam@netfilter.org>
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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/module.h>
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#include <linux/skbuff.h>
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#include <net/netfilter/nf_conntrack.h>
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#include <linux/netfilter/x_tables.h>
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#include <linux/netfilter/xt_state.h>
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Rusty Russell <rusty@rustcorp.com.au>");
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MODULE_DESCRIPTION("ip[6]_tables connection tracking state match module");
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MODULE_ALIAS("ipt_state");
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MODULE_ALIAS("ip6t_state");
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static bool
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state_mt(const struct sk_buff *skb, const struct xt_match_param *par)
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{
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const struct xt_state_info *sinfo = par->matchinfo;
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enum ip_conntrack_info ctinfo;
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unsigned int statebit;
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if (nf_ct_is_untracked(skb))
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statebit = XT_STATE_UNTRACKED;
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else if (!nf_ct_get(skb, &ctinfo))
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statebit = XT_STATE_INVALID;
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else
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statebit = XT_STATE_BIT(ctinfo);
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return (sinfo->statemask & statebit);
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}
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static bool
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state_mt_check(const char *tablename, const void *inf,
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const struct xt_match *match, void *matchinfo,
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unsigned int hook_mask)
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{
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if (nf_ct_l3proto_try_module_get(match->family) < 0) {
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printk(KERN_WARNING "can't load conntrack support for "
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"proto=%u\n", match->family);
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return false;
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}
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return true;
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}
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static void state_mt_destroy(const struct xt_match *match, void *matchinfo)
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{
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nf_ct_l3proto_module_put(match->family);
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}
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static struct xt_match state_mt_reg[] __read_mostly = {
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{
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.name = "state",
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.family = NFPROTO_IPV4,
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.checkentry = state_mt_check,
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.match = state_mt,
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.destroy = state_mt_destroy,
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.matchsize = sizeof(struct xt_state_info),
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.me = THIS_MODULE,
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},
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{
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.name = "state",
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.family = NFPROTO_IPV6,
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.checkentry = state_mt_check,
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.match = state_mt,
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.destroy = state_mt_destroy,
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.matchsize = sizeof(struct xt_state_info),
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.me = THIS_MODULE,
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},
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};
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static int __init state_mt_init(void)
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{
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return xt_register_matches(state_mt_reg, ARRAY_SIZE(state_mt_reg));
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}
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static void __exit state_mt_exit(void)
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{
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xt_unregister_matches(state_mt_reg, ARRAY_SIZE(state_mt_reg));
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}
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module_init(state_mt_init);
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module_exit(state_mt_exit);
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