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>
93 lines
2 KiB
C
93 lines
2 KiB
C
/* This is a module which is used for setting up fake conntracks
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* on packets so that they are not seen by the conntrack/NAT code.
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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 <linux/netfilter/x_tables.h>
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#include <net/netfilter/nf_conntrack_compat.h>
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("ipt_NOTRACK");
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static unsigned int
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target(struct sk_buff **pskb,
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const struct net_device *in,
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const struct net_device *out,
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unsigned int hooknum,
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const void *targinfo,
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void *userinfo)
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{
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/* Previously seen (loopback)? Ignore. */
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if ((*pskb)->nfct != NULL)
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return XT_CONTINUE;
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/* Attach fake conntrack entry.
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If there is a real ct entry correspondig to this packet,
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it'll hang aroun till timing out. We don't deal with it
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for performance reasons. JK */
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nf_ct_untrack(*pskb);
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(*pskb)->nfctinfo = IP_CT_NEW;
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nf_conntrack_get((*pskb)->nfct);
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return XT_CONTINUE;
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}
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static int
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checkentry(const char *tablename,
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const void *entry,
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void *targinfo,
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unsigned int targinfosize,
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unsigned int hook_mask)
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{
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if (targinfosize != 0) {
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printk(KERN_WARNING "NOTRACK: targinfosize %u != 0\n",
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targinfosize);
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return 0;
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}
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if (strcmp(tablename, "raw") != 0) {
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printk(KERN_WARNING "NOTRACK: can only be called from \"raw\" table, not \"%s\"\n", tablename);
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return 0;
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}
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return 1;
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}
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static struct xt_target notrack_reg = {
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.name = "NOTRACK",
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.target = target,
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.checkentry = checkentry,
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.me = THIS_MODULE,
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};
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static struct xt_target notrack6_reg = {
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.name = "NOTRACK",
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.target = target,
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.checkentry = checkentry,
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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_target(AF_INET, ¬rack_reg);
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if (ret)
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return ret;
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ret = xt_register_target(AF_INET6, ¬rack6_reg);
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if (ret)
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xt_unregister_target(AF_INET, ¬rack_reg);
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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_target(AF_INET6, ¬rack6_reg);
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xt_unregister_target(AF_INET, ¬rack_reg);
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}
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module_init(init);
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module_exit(fini);
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