diff options
Diffstat (limited to 'net/netfilter/nf_nat_irc.c')
-rw-r--r-- | net/netfilter/nf_nat_irc.c | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/net/netfilter/nf_nat_irc.c b/net/netfilter/nf_nat_irc.c new file mode 100644 index 00000000000..1fedee6e7fb --- /dev/null +++ b/net/netfilter/nf_nat_irc.c | |||
@@ -0,0 +1,93 @@ | |||
1 | /* IRC extension for TCP NAT alteration. | ||
2 | * | ||
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 | ||
6 | * | ||
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. | ||
11 | */ | ||
12 | |||
13 | #include <linux/module.h> | ||
14 | #include <linux/moduleparam.h> | ||
15 | #include <linux/tcp.h> | ||
16 | #include <linux/kernel.h> | ||
17 | |||
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> | ||
23 | |||
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"); | ||
28 | |||
29 | static unsigned int help(struct sk_buff *skb, | ||
30 | enum ip_conntrack_info ctinfo, | ||
31 | unsigned int protoff, | ||
32 | unsigned int matchoff, | ||
33 | unsigned int matchlen, | ||
34 | struct nf_conntrack_expect *exp) | ||
35 | { | ||
36 | char buffer[sizeof("4294967296 65635")]; | ||
37 | u_int16_t port; | ||
38 | unsigned int ret; | ||
39 | |||
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; | ||
44 | |||
45 | /* Try to get same port: if not, try to change it. */ | ||
46 | for (port = ntohs(exp->saved_proto.tcp.port); port != 0; port++) { | ||
47 | int ret; | ||
48 | |||
49 | exp->tuple.dst.u.tcp.port = htons(port); | ||
50 | ret = nf_ct_expect_related(exp); | ||
51 | if (ret == 0) | ||
52 | break; | ||
53 | else if (ret != -EBUSY) { | ||
54 | port = 0; | ||
55 | break; | ||
56 | } | ||
57 | } | ||
58 | |||
59 | if (port == 0) | ||
60 | return NF_DROP; | ||
61 | |||
62 | ret = nf_nat_mangle_tcp_packet(skb, exp->master, ctinfo, | ||
63 | protoff, matchoff, matchlen, buffer, | ||
64 | strlen(buffer)); | ||
65 | if (ret != NF_ACCEPT) | ||
66 | nf_ct_unexpect_related(exp); | ||
67 | return ret; | ||
68 | } | ||
69 | |||
70 | static void __exit nf_nat_irc_fini(void) | ||
71 | { | ||
72 | RCU_INIT_POINTER(nf_nat_irc_hook, NULL); | ||
73 | synchronize_rcu(); | ||
74 | } | ||
75 | |||
76 | static int __init nf_nat_irc_init(void) | ||
77 | { | ||
78 | BUG_ON(nf_nat_irc_hook != NULL); | ||
79 | RCU_INIT_POINTER(nf_nat_irc_hook, help); | ||
80 | return 0; | ||
81 | } | ||
82 | |||
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) | ||
85 | { | ||
86 | printk(KERN_INFO KBUILD_MODNAME | ||
87 | ": kernel >= 2.6.10 only uses 'ports' for conntrack modules\n"); | ||
88 | return 0; | ||
89 | } | ||
90 | module_param_call(ports, warn_set, NULL, NULL, 0); | ||
91 | |||
92 | module_init(nf_nat_irc_init); | ||
93 | module_exit(nf_nat_irc_fini); | ||