From 5901b6be885e2c9a30fd94803b846b3d33e351dd Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Sun, 26 Aug 2012 19:14:27 +0200 Subject: netfilter: nf_nat: support IPv6 in IRC NAT helper Signed-off-by: Pablo Neira Ayuso Signed-off-by: Patrick McHardy --- net/netfilter/nf_nat_irc.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 93 insertions(+) create mode 100644 net/netfilter/nf_nat_irc.c (limited to 'net/netfilter/nf_nat_irc.c') diff --git a/net/netfilter/nf_nat_irc.c b/net/netfilter/nf_nat_irc.c new file mode 100644 index 000000000000..1fedee6e7fb6 --- /dev/null +++ b/net/netfilter/nf_nat_irc.c @@ -0,0 +1,93 @@ +/* IRC extension for TCP NAT alteration. + * + * (C) 2000-2001 by Harald Welte + * (C) 2004 Rusty Russell 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 +#include +#include +#include + +#include +#include +#include +#include +#include + +MODULE_AUTHOR("Harald Welte "); +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 protoff, + unsigned int matchoff, + unsigned int matchlen, + struct nf_conntrack_expect *exp) +{ + char buffer[sizeof("4294967296 65635")]; + 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++) { + int ret; + + exp->tuple.dst.u.tcp.port = htons(port); + ret = nf_ct_expect_related(exp); + if (ret == 0) + break; + else if (ret != -EBUSY) { + port = 0; + break; + } + } + + if (port == 0) + return NF_DROP; + + ret = nf_nat_mangle_tcp_packet(skb, exp->master, ctinfo, + protoff, 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_INIT_POINTER(nf_nat_irc_hook, NULL); + synchronize_rcu(); +} + +static int __init nf_nat_irc_init(void) +{ + BUG_ON(nf_nat_irc_hook != NULL); + RCU_INIT_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); -- cgit v1.2.3