1 /* IRC extension for TCP NAT alteration.
3 * (C) 2000-2001 by Harald Welte <laforge@gnumonks.org>
4 * (C) 2004 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
5 * based on a copy of RR's ip_nat_ftp.c
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
13 #include <linux/module.h>
14 #include <linux/moduleparam.h>
15 #include <linux/tcp.h>
16 #include <linux/kernel.h>
18 #include <net/netfilter/nf_nat.h>
19 #include <net/netfilter/nf_nat_helper.h>
20 #include <net/netfilter/nf_conntrack_helper.h>
21 #include <net/netfilter/nf_conntrack_expect.h>
22 #include <linux/netfilter/nf_conntrack_irc.h>
24 MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>");
25 MODULE_DESCRIPTION("IRC (DCC) NAT helper");
26 MODULE_LICENSE("GPL");
27 MODULE_ALIAS("ip_nat_irc");
29 static unsigned int help(struct sk_buff
*skb
,
30 enum ip_conntrack_info ctinfo
,
32 unsigned int matchoff
,
33 unsigned int matchlen
,
34 struct nf_conntrack_expect
*exp
)
36 char buffer
[sizeof("4294967296 65635")];
40 /* Reply comes from server. */
41 exp
->saved_proto
.tcp
.port
= exp
->tuple
.dst
.u
.tcp
.port
;
42 exp
->dir
= IP_CT_DIR_REPLY
;
43 exp
->expectfn
= nf_nat_follow_master
;
45 /* Try to get same port: if not, try to change it. */
46 for (port
= ntohs(exp
->saved_proto
.tcp
.port
); port
!= 0; port
++) {
49 exp
->tuple
.dst
.u
.tcp
.port
= htons(port
);
50 ret
= nf_ct_expect_related(exp
);
53 else if (ret
!= -EBUSY
) {
62 ret
= nf_nat_mangle_tcp_packet(skb
, exp
->master
, ctinfo
,
63 protoff
, matchoff
, matchlen
, buffer
,
66 nf_ct_unexpect_related(exp
);
70 static void __exit
nf_nat_irc_fini(void)
72 RCU_INIT_POINTER(nf_nat_irc_hook
, NULL
);
76 static int __init
nf_nat_irc_init(void)
78 BUG_ON(nf_nat_irc_hook
!= NULL
);
79 RCU_INIT_POINTER(nf_nat_irc_hook
, help
);
83 /* Prior to 2.6.11, we had a ports param. No longer, but don't break users. */
84 static int warn_set(const char *val
, struct kernel_param
*kp
)
86 printk(KERN_INFO KBUILD_MODNAME
87 ": kernel >= 2.6.10 only uses 'ports' for conntrack modules\n");
90 module_param_call(ports
, warn_set
, NULL
, NULL
, 0);
92 module_init(nf_nat_irc_init
);
93 module_exit(nf_nat_irc_fini
);