Commit 16958900 authored by Patrick McHardy's avatar Patrick McHardy Committed by David S. Miller
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[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: default avatarPatrick McHardy <kaber@trash.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d6a9b650
#ifndef _NF_CONNTRACK_AMANDA_H
#define _NF_CONNTRACK_AMANDA_H
/* AMANDA tracking. */
extern unsigned int (*nf_nat_amanda_hook)(struct sk_buff **pskb,
enum ip_conntrack_info ctinfo,
unsigned int matchoff,
unsigned int matchlen,
struct nf_conntrack_expect *exp);
#endif /* _NF_CONNTRACK_AMANDA_H */
......@@ -512,6 +512,11 @@ config IP_NF_NAT_AMANDA
default IP_NF_NAT if IP_NF_AMANDA=y
default m if IP_NF_AMANDA=m
config NF_NAT_AMANDA
tristate
depends on IP_NF_IPTABLES && NF_CONNTRACK && NF_NAT
default NF_NAT && NF_CONNTRACK_AMANDA
config IP_NF_NAT_PPTP
tristate
depends on IP_NF_NAT!=n && IP_NF_PPTP!=n
......
......@@ -50,6 +50,7 @@ obj-$(CONFIG_IP_NF_NAT_IRC) += ip_nat_irc.o
obj-$(CONFIG_IP_NF_NAT_SIP) += ip_nat_sip.o
# NAT helpers (nf_conntrack)
obj-$(CONFIG_NF_NAT_AMANDA) += nf_nat_amanda.o
obj-$(CONFIG_NF_NAT_FTP) += nf_nat_ftp.o
# generic IP tables
......
/* 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);
......@@ -131,6 +131,21 @@ config NF_CT_PROTO_SCTP
If you want to compile it as a module, say M here and read
Documentation/modules.txt. If unsure, say `N'.
config NF_CONNTRACK_AMANDA
tristate "Amanda backup protocol support (EXPERIMENTAL)"
depends on EXPERIMENTAL && NF_CONNTRACK
select TEXTSEARCH
select TEXTSEARCH_KMP
help
If you are running the Amanda backup package <http://www.amanda.org/>
on this machine or machines that will be MASQUERADED through this
machine, then you may want to enable this feature. This allows the
connection tracking and natting code to allow the sub-channels that
Amanda requires for communication of the backup data, messages and
index.
To compile it as a module, choose M here. If unsure, say N.
config NF_CONNTRACK_FTP
tristate "FTP support on new connection tracking (EXPERIMENTAL)"
depends on EXPERIMENTAL && NF_CONNTRACK
......
......@@ -20,6 +20,7 @@ obj-$(CONFIG_NF_CT_PROTO_SCTP) += nf_conntrack_proto_sctp.o
obj-$(CONFIG_NF_CT_NETLINK) += nf_conntrack_netlink.o
# connection tracking helpers
obj-$(CONFIG_NF_CONNTRACK_AMANDA) += nf_conntrack_amanda.o
obj-$(CONFIG_NF_CONNTRACK_FTP) += nf_conntrack_ftp.o
# generic X tables
......
/* Amanda extension for IP connection tracking
*
* (C) 2002 by Brian J. Murrell <netfilter@interlinx.bc.ca>
* based on HW's ip_conntrack_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/moduleparam.h>
#include <linux/textsearch.h>
#include <linux/skbuff.h>
#include <linux/in.h>
#include <linux/udp.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_expect.h>
#include <net/netfilter/nf_conntrack_ecache.h>
#include <net/netfilter/nf_conntrack_helper.h>
#include <linux/netfilter/nf_conntrack_amanda.h>
static unsigned int master_timeout __read_mostly = 300;
static char *ts_algo = "kmp";
MODULE_AUTHOR("Brian J. Murrell <netfilter@interlinx.bc.ca>");
MODULE_DESCRIPTION("Amanda connection tracking module");
MODULE_LICENSE("GPL");
MODULE_ALIAS("ip_conntrack_amanda");
module_param(master_timeout, uint, 0600);
MODULE_PARM_DESC(master_timeout, "timeout for the master connection");
module_param(ts_algo, charp, 0400);
MODULE_PARM_DESC(ts_algo, "textsearch algorithm to use (default kmp)");
unsigned int (*nf_nat_amanda_hook)(struct sk_buff **pskb,
enum ip_conntrack_info ctinfo,
unsigned int matchoff,
unsigned int matchlen,
struct nf_conntrack_expect *exp)
__read_mostly;
EXPORT_SYMBOL_GPL(nf_nat_amanda_hook);
enum amanda_strings {
SEARCH_CONNECT,
SEARCH_NEWLINE,
SEARCH_DATA,
SEARCH_MESG,
SEARCH_INDEX,
};
static struct {
char *string;
size_t len;
struct ts_config *ts;
} search[] __read_mostly = {
[SEARCH_CONNECT] = {
.string = "CONNECT ",
.len = 8,
},
[SEARCH_NEWLINE] = {
.string = "\n",
.len = 1,
},
[SEARCH_DATA] = {
.string = "DATA ",
.len = 5,
},
[SEARCH_MESG] = {
.string = "MESG ",
.len = 5,
},
[SEARCH_INDEX] = {
.string = "INDEX ",
.len = 6,
},
};
static int amanda_help(struct sk_buff **pskb,
unsigned int protoff,
struct nf_conn *ct,
enum ip_conntrack_info ctinfo)
{
struct ts_state ts;
struct nf_conntrack_expect *exp;
struct nf_conntrack_tuple *tuple;
unsigned int dataoff, start, stop, off, i;
char pbuf[sizeof("65535")], *tmp;
u_int16_t len;
__be16 port;
int family = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
int ret = NF_ACCEPT;
typeof(nf_nat_amanda_hook) nf_nat_amanda;
/* Only look at packets from the Amanda server */
if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
return NF_ACCEPT;
/* increase the UDP timeout of the master connection as replies from
* Amanda clients to the server can be quite delayed */
nf_ct_refresh(ct, *pskb, master_timeout * HZ);
/* No data? */
dataoff = protoff + sizeof(struct udphdr);
if (dataoff >= (*pskb)->len) {
if (net_ratelimit())
printk("amanda_help: skblen = %u\n", (*pskb)->len);
return NF_ACCEPT;
}
memset(&ts, 0, sizeof(ts));
start = skb_find_text(*pskb, dataoff, (*pskb)->len,
search[SEARCH_CONNECT].ts, &ts);
if (start == UINT_MAX)
goto out;
start += dataoff + search[SEARCH_CONNECT].len;
memset(&ts, 0, sizeof(ts));
stop = skb_find_text(*pskb, start, (*pskb)->len,
search[SEARCH_NEWLINE].ts, &ts);
if (stop == UINT_MAX)
goto out;
stop += start;
for (i = SEARCH_DATA; i <= SEARCH_INDEX; i++) {
memset(&ts, 0, sizeof(ts));
off = skb_find_text(*pskb, start, stop, search[i].ts, &ts);
if (off == UINT_MAX)
continue;
off += start + search[i].len;
len = min_t(unsigned int, sizeof(pbuf) - 1, stop - off);
if (skb_copy_bits(*pskb, off, pbuf, len))
break;
pbuf[len] = '\0';
port = htons(simple_strtoul(pbuf, &tmp, 10));
len = tmp - pbuf;
if (port == 0 || len > 5)
break;
exp = nf_conntrack_expect_alloc(ct);
if (exp == NULL) {
ret = NF_DROP;
goto out;
}
tuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
nf_conntrack_expect_init(exp, family,
&tuple->src.u3, &tuple->dst.u3,
IPPROTO_TCP, NULL, &port);
nf_nat_amanda = rcu_dereference(nf_nat_amanda_hook);
if (nf_nat_amanda && ct->status & IPS_NAT_MASK)
ret = nf_nat_amanda(pskb, ctinfo, off - dataoff,
len, exp);
else if (nf_conntrack_expect_related(exp) != 0)
ret = NF_DROP;
nf_conntrack_expect_put(exp);
}
out:
return ret;
}
static struct nf_conntrack_helper amanda_helper[2] __read_mostly = {
{
.name = "amanda",
.max_expected = 3,
.timeout = 180,
.me = THIS_MODULE,
.help = amanda_help,
.tuple.src.l3num = AF_INET,
.tuple.src.u.udp.port = __constant_htons(10080),
.tuple.dst.protonum = IPPROTO_UDP,
.mask.src.l3num = 0xFFFF,
.mask.src.u.udp.port = __constant_htons(0xFFFF),
.mask.dst.protonum = 0xFF,
},
{
.name = "amanda",
.max_expected = 3,
.timeout = 180,
.me = THIS_MODULE,
.help = amanda_help,
.tuple.src.l3num = AF_INET6,
.tuple.src.u.udp.port = __constant_htons(10080),
.tuple.dst.protonum = IPPROTO_UDP,
.mask.src.l3num = 0xFFFF,
.mask.src.u.udp.port = __constant_htons(0xFFFF),
.mask.dst.protonum = 0xFF,
},
};
static void __exit nf_conntrack_amanda_fini(void)
{
int i;
nf_conntrack_helper_unregister(&amanda_helper[0]);
nf_conntrack_helper_unregister(&amanda_helper[1]);
for (i = 0; i < ARRAY_SIZE(search); i++)
textsearch_destroy(search[i].ts);
}
static int __init nf_conntrack_amanda_init(void)
{
int ret, i;
ret = -ENOMEM;
for (i = 0; i < ARRAY_SIZE(search); i++) {
search[i].ts = textsearch_prepare(ts_algo, search[i].string,
search[i].len,
GFP_KERNEL, TS_AUTOLOAD);
if (search[i].ts == NULL)
goto err1;
}
ret = nf_conntrack_helper_register(&amanda_helper[0]);
if (ret < 0)
goto err1;
ret = nf_conntrack_helper_register(&amanda_helper[1]);
if (ret < 0)
goto err2;
return 0;
err2:
nf_conntrack_helper_unregister(&amanda_helper[0]);
err1:
for (; i >= 0; i--) {
if (search[i].ts)
textsearch_destroy(search[i].ts);
}
return ret;
}
module_init(nf_conntrack_amanda_init);
module_exit(nf_conntrack_amanda_fini);
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