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5abd363f73
The port rover should not get overwritten when using random mode, otherwise other rules will also use more or less random ports. Signed-off-by: Patrick McHardy <kaber@trash.net>
90 lines
2.3 KiB
C
90 lines
2.3 KiB
C
/* (C) 1999-2001 Paul `Rusty' Russell
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* (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
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* (C) 2008 Patrick McHardy <kaber@trash.net>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/types.h>
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#include <linux/random.h>
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#include <linux/ip.h>
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#include <linux/netfilter.h>
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#include <net/netfilter/nf_nat.h>
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#include <net/netfilter/nf_nat_core.h>
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#include <net/netfilter/nf_nat_rule.h>
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#include <net/netfilter/nf_nat_protocol.h>
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int nf_nat_proto_in_range(const struct nf_conntrack_tuple *tuple,
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enum nf_nat_manip_type maniptype,
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const union nf_conntrack_man_proto *min,
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const union nf_conntrack_man_proto *max)
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{
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__be16 port;
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if (maniptype == IP_NAT_MANIP_SRC)
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port = tuple->src.u.all;
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else
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port = tuple->dst.u.all;
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return ntohs(port) >= ntohs(min->all) &&
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ntohs(port) <= ntohs(max->all);
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}
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EXPORT_SYMBOL_GPL(nf_nat_proto_in_range);
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int nf_nat_proto_unique_tuple(struct nf_conntrack_tuple *tuple,
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const struct nf_nat_range *range,
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enum nf_nat_manip_type maniptype,
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const struct nf_conn *ct,
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u_int16_t *rover)
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{
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unsigned int range_size, min, i;
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__be16 *portptr;
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u_int16_t off;
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if (maniptype == IP_NAT_MANIP_SRC)
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portptr = &tuple->src.u.all;
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else
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portptr = &tuple->dst.u.all;
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/* If no range specified... */
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if (!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED)) {
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/* If it's dst rewrite, can't change port */
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if (maniptype == IP_NAT_MANIP_DST)
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return 0;
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if (ntohs(*portptr) < 1024) {
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/* Loose convention: >> 512 is credential passing */
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if (ntohs(*portptr) < 512) {
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min = 1;
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range_size = 511 - min + 1;
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} else {
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min = 600;
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range_size = 1023 - min + 1;
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}
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} else {
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min = 1024;
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range_size = 65535 - 1024 + 1;
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}
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} else {
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min = ntohs(range->min.all);
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range_size = ntohs(range->max.all) - min + 1;
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}
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off = *rover;
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if (range->flags & IP_NAT_RANGE_PROTO_RANDOM)
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off = net_random();
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for (i = 0; i < range_size; i++, off++) {
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*portptr = htons(min + off % range_size);
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if (nf_nat_used_tuple(tuple, ct))
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continue;
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if (!(range->flags & IP_NAT_RANGE_PROTO_RANDOM))
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*rover = off;
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return 1;
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}
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return 0;
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}
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EXPORT_SYMBOL_GPL(nf_nat_proto_unique_tuple);
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