swh:1:snp:49cd9498d6cccc5e78252c27dcb645bcf7bf0c91
Tip revision: 74fca6a42863ffacaf7ba6f1936a9f228950f657 authored by Linus Torvalds on 09 September 2009, 22:13:59 UTC
Linux 2.6.31
Linux 2.6.31
Tip revision: 74fca6a
nf_nat_irc.c
/* IRC extension for TCP NAT alteration.
*
* (C) 2000-2001 by Harald Welte <laforge@gnumonks.org>
* (C) 2004 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
* based on a copy of RR's ip_nat_ftp.c
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/tcp.h>
#include <linux/kernel.h>
#include <net/netfilter/nf_nat.h>
#include <net/netfilter/nf_nat_helper.h>
#include <net/netfilter/nf_nat_rule.h>
#include <net/netfilter/nf_conntrack_helper.h>
#include <net/netfilter/nf_conntrack_expect.h>
#include <linux/netfilter/nf_conntrack_irc.h>
MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>");
MODULE_DESCRIPTION("IRC (DCC) NAT helper");
MODULE_LICENSE("GPL");
MODULE_ALIAS("ip_nat_irc");
static unsigned int help(struct sk_buff *skb,
enum ip_conntrack_info ctinfo,
unsigned int matchoff,
unsigned int matchlen,
struct nf_conntrack_expect *exp)
{
char buffer[sizeof("4294967296 65635")];
u_int32_t ip;
u_int16_t port;
unsigned int ret;
/* Reply comes from server. */
exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port;
exp->dir = IP_CT_DIR_REPLY;
exp->expectfn = nf_nat_follow_master;
/* Try to get same port: if not, try to change it. */
for (port = ntohs(exp->saved_proto.tcp.port); port != 0; port++) {
exp->tuple.dst.u.tcp.port = htons(port);
if (nf_ct_expect_related(exp) == 0)
break;
}
if (port == 0)
return NF_DROP;
ip = ntohl(exp->master->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip);
sprintf(buffer, "%u %u", ip, port);
pr_debug("nf_nat_irc: inserting '%s' == %pI4, port %u\n",
buffer, &ip, port);
ret = nf_nat_mangle_tcp_packet(skb, exp->master, ctinfo,
matchoff, matchlen, buffer,
strlen(buffer));
if (ret != NF_ACCEPT)
nf_ct_unexpect_related(exp);
return ret;
}
static void __exit nf_nat_irc_fini(void)
{
rcu_assign_pointer(nf_nat_irc_hook, NULL);
synchronize_rcu();
}
static int __init nf_nat_irc_init(void)
{
BUG_ON(nf_nat_irc_hook != NULL);
rcu_assign_pointer(nf_nat_irc_hook, help);
return 0;
}
/* Prior to 2.6.11, we had a ports param. No longer, but don't break users. */
static int warn_set(const char *val, struct kernel_param *kp)
{
printk(KERN_INFO KBUILD_MODNAME
": kernel >= 2.6.10 only uses 'ports' for conntrack modules\n");
return 0;
}
module_param_call(ports, warn_set, NULL, NULL, 0);
module_init(nf_nat_irc_init);
module_exit(nf_nat_irc_fini);