From ee6eb96673704225164f0ba7462e1973ce10885c Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Sun, 26 Aug 2012 19:14:22 +0200 Subject: netfilter: nf_nat: support IPv6 in amanda NAT helper Signed-off-by: Patrick McHardy --- net/netfilter/nf_nat_amanda.c | 85 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 85 insertions(+) create mode 100644 net/netfilter/nf_nat_amanda.c (limited to 'net/netfilter/nf_nat_amanda.c') diff --git a/net/netfilter/nf_nat_amanda.c b/net/netfilter/nf_nat_amanda.c new file mode 100644 index 000000000000..42d337881171 --- /dev/null +++ b/net/netfilter/nf_nat_amanda.c @@ -0,0 +1,85 @@ +/* Amanda extension for TCP NAT alteration. + * (C) 2002 by Brian J. Murrell + * based on a copy of HW's ip_nat_irc.c as well as other modules + * + * 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 + +MODULE_AUTHOR("Brian J. Murrell "); +MODULE_DESCRIPTION("Amanda NAT helper"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("ip_nat_amanda"); + +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("65535")]; + u_int16_t port; + unsigned int ret; + + /* Connection comes from client. */ + exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port; + exp->dir = IP_CT_DIR_ORIGINAL; + + /* When you see the packet, we need to NAT it the same as the + * this one (ie. same IP: it will be TCP and master is UDP). */ + 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 res; + + exp->tuple.dst.u.tcp.port = htons(port); + res = nf_ct_expect_related(exp); + if (res == 0) + break; + else if (res != -EBUSY) { + port = 0; + break; + } + } + + if (port == 0) + return NF_DROP; + + sprintf(buffer, "%u", port); + ret = nf_nat_mangle_udp_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_amanda_fini(void) +{ + RCU_INIT_POINTER(nf_nat_amanda_hook, NULL); + synchronize_rcu(); +} + +static int __init nf_nat_amanda_init(void) +{ + BUG_ON(nf_nat_amanda_hook != NULL); + RCU_INIT_POINTER(nf_nat_amanda_hook, help); + return 0; +} + +module_init(nf_nat_amanda_init); +module_exit(nf_nat_amanda_fini); -- cgit v1.2.3