diff options
author | Patrick McHardy <kaber@trash.net> | 2006-12-03 06:08:26 (GMT) |
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committer | David S. Miller <davem@davemloft.net> | 2006-12-03 06:08:26 (GMT) |
commit | 16958900578b94585c2ab9a2d20d837b4d5e3ba6 (patch) | |
tree | 91d198f1287535821ccc4d2f4dcdf9d8aa3b8483 /net/ipv4/netfilter/nf_nat_amanda.c | |
parent | d6a9b6500a8941599bcef98e7de49e1260d104ed (diff) | |
download | linux-fsl-qoriq-16958900578b94585c2ab9a2d20d837b4d5e3ba6.tar.xz |
[NETFILTER]: nf_conntrack/nf_nat: add amanda helper port
Add IPv4 and IPv6 capable nf_conntrack port of the Amanda conntrack/NAT helper.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/netfilter/nf_nat_amanda.c')
-rw-r--r-- | net/ipv4/netfilter/nf_nat_amanda.c | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/net/ipv4/netfilter/nf_nat_amanda.c b/net/ipv4/netfilter/nf_nat_amanda.c new file mode 100644 index 0000000..0f17098 --- /dev/null +++ b/net/ipv4/netfilter/nf_nat_amanda.c @@ -0,0 +1,78 @@ +/* Amanda extension for TCP NAT alteration. + * (C) 2002 by Brian J. Murrell <netfilter@interlinx.bc.ca> + * 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 <linux/kernel.h> +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/udp.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_amanda.h> + +MODULE_AUTHOR("Brian J. Murrell <netfilter@interlinx.bc.ca>"); +MODULE_DESCRIPTION("Amanda NAT helper"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("ip_nat_amanda"); + +static unsigned int help(struct sk_buff **pskb, + enum ip_conntrack_info ctinfo, + 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++) { + exp->tuple.dst.u.tcp.port = htons(port); + if (nf_conntrack_expect_related(exp) == 0) + break; + } + + if (port == 0) + return NF_DROP; + + sprintf(buffer, "%u", port); + ret = nf_nat_mangle_udp_packet(pskb, exp->master, ctinfo, + matchoff, matchlen, + buffer, strlen(buffer)); + if (ret != NF_ACCEPT) + nf_conntrack_unexpect_related(exp); + return ret; +} + +static void __exit nf_nat_amanda_fini(void) +{ + rcu_assign_pointer(nf_nat_amanda_hook, NULL); + synchronize_rcu(); +} + +static int __init nf_nat_amanda_init(void) +{ + BUG_ON(rcu_dereference(nf_nat_amanda_hook)); + rcu_assign_pointer(nf_nat_amanda_hook, help); + return 0; +} + +module_init(nf_nat_amanda_init); +module_exit(nf_nat_amanda_fini); |