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/* (C) 1999-2001 Paul `Rusty' Russell
* (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
* (C) 2008 Patrick McHardy <kaber@trash.net>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/types.h>
#include <linux/random.h>
#include <linux/ip.h>
#include <linux/netfilter.h>
#include <net/secure_seq.h>
#include <net/netfilter/nf_nat.h>
#include <net/netfilter/nf_nat_core.h>
#include <net/netfilter/nf_nat_rule.h>
#include <net/netfilter/nf_nat_protocol.h>
bool nf_nat_proto_in_range(const struct nf_conntrack_tuple *tuple,
enum nf_nat_manip_type maniptype,
const union nf_conntrack_man_proto *min,
const union nf_conntrack_man_proto *max)
{
__be16 port;
if (maniptype == IP_NAT_MANIP_SRC)
port = tuple->src.u.all;
else
port = tuple->dst.u.all;
return ntohs(port) >= ntohs(min->all) &&
ntohs(port) <= ntohs(max->all);
}
EXPORT_SYMBOL_GPL(nf_nat_proto_in_range);
void nf_nat_proto_unique_tuple(struct nf_conntrack_tuple *tuple,
const struct nf_nat_range *range,
enum nf_nat_manip_type maniptype,
const struct nf_conn *ct,
u_int16_t *rover)
{
unsigned int range_size, min, i;
__be16 *portptr;
u_int16_t off;
if (maniptype == IP_NAT_MANIP_SRC)
portptr = &tuple->src.u.all;
else
portptr = &tuple->dst.u.all;
/* If no range specified... */
if (!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED)) {
/* If it's dst rewrite, can't change port */
if (maniptype == IP_NAT_MANIP_DST)
return;
if (ntohs(*portptr) < 1024) {
/* Loose convention: >> 512 is credential passing */
if (ntohs(*portptr) < 512) {
min = 1;
range_size = 511 - min + 1;
} else {
min = 600;
range_size = 1023 - min + 1;
}
} else {
min = 1024;
range_size = 65535 - 1024 + 1;
}
} else {
min = ntohs(range->min.all);
range_size = ntohs(range->max.all) - min + 1;
}
if (range->flags & IP_NAT_RANGE_PROTO_RANDOM)
off = secure_ipv4_port_ephemeral(tuple->src.u3.ip, tuple->dst.u3.ip,
maniptype == IP_NAT_MANIP_SRC
? tuple->dst.u.all
: tuple->src.u.all);
else
off = *rover;
for (i = 0; ; ++off) {
*portptr = htons(min + off % range_size);
if (++i != range_size && nf_nat_used_tuple(tuple, ct))
continue;
if (!(range->flags & IP_NAT_RANGE_PROTO_RANDOM))
*rover = off;
return;
}
return;
}
EXPORT_SYMBOL_GPL(nf_nat_proto_unique_tuple);
#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
int nf_nat_proto_range_to_nlattr(struct sk_buff *skb,
const struct nf_nat_range *range)
{
NLA_PUT_BE16(skb, CTA_PROTONAT_PORT_MIN, range->min.all);
NLA_PUT_BE16(skb, CTA_PROTONAT_PORT_MAX, range->max.all);
return 0;
nla_put_failure:
return -1;
}
EXPORT_SYMBOL_GPL(nf_nat_proto_nlattr_to_range);
int nf_nat_proto_nlattr_to_range(struct nlattr *tb[],
struct nf_nat_range *range)
{
if (tb[CTA_PROTONAT_PORT_MIN]) {
range->min.all = nla_get_be16(tb[CTA_PROTONAT_PORT_MIN]);
range->max.all = range->min.tcp.port;
range->flags |= IP_NAT_RANGE_PROTO_SPECIFIED;
}
if (tb[CTA_PROTONAT_PORT_MAX]) {
range->max.all = nla_get_be16(tb[CTA_PROTONAT_PORT_MAX]);
range->flags |= IP_NAT_RANGE_PROTO_SPECIFIED;
}
return 0;
}
EXPORT_SYMBOL_GPL(nf_nat_proto_range_to_nlattr);
#endif
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