diff options
author | Harald Welte <laforge@netfilter.org> | 2006-01-12 13:30:04 -0800 |
---|---|---|
committer | David S. Miller <davem@sunset.davemloft.net> | 2006-01-12 14:06:43 -0800 |
commit | 2e4e6a17af35be359cc8f1c924f8f198fbd478cc (patch) | |
tree | cb4b5438dcf9ff9d57518a26124308bcbfffd214 /net/netfilter/xt_state.c | |
parent | 880b005f294454d989783d0984dc554dfe3c8214 (diff) |
[NETFILTER] x_tables: Abstraction layer for {ip,ip6,arp}_tables
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>
Diffstat (limited to 'net/netfilter/xt_state.c')
-rw-r--r-- | net/netfilter/xt_state.c | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/net/netfilter/xt_state.c b/net/netfilter/xt_state.c new file mode 100644 index 000000000000..39ce808d40ef --- /dev/null +++ b/net/netfilter/xt_state.c @@ -0,0 +1,96 @@ +/* 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 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 *ip, + void *matchinfo, + unsigned int matchsize, + unsigned int hook_mask) +{ + if (matchsize != XT_ALIGN(sizeof(struct xt_state_info))) + return 0; + + return 1; +} + +static struct xt_match state_match = { + .name = "state", + .match = &match, + .checkentry = &check, + .me = THIS_MODULE, +}; + +static struct xt_match state6_match = { + .name = "state", + .match = &match, + .checkentry = &check, + .me = THIS_MODULE, +}; + +static int __init init(void) +{ + int ret; + + need_conntrack(); + + ret = xt_register_match(AF_INET, &state_match); + if (ret < 0) + return ret; + + ret = xt_register_match(AF_INET6, &state6_match); + if (ret < 0) + xt_unregister_match(AF_INET,&state_match); + + return ret; +} + +static void __exit fini(void) +{ + xt_unregister_match(AF_INET, &state_match); + xt_unregister_match(AF_INET6, &state6_match); +} + +module_init(init); +module_exit(fini); |