2006-12-03 06:07:13 +00:00
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/* (C) 1999-2001 Paul `Rusty' Russell
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* (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
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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/init.h>
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2011-07-15 15:47:34 +00:00
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#include <linux/export.h>
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2006-12-03 06:07:13 +00:00
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#include <linux/ip.h>
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#include <linux/icmp.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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2012-08-26 17:14:06 +00:00
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#include <net/netfilter/nf_nat_l4proto.h>
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2006-12-03 06:07:13 +00:00
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2008-04-14 09:15:53 +00:00
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static bool
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2006-12-03 06:07:13 +00:00
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icmp_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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return ntohs(tuple->src.u.icmp.id) >= ntohs(min->icmp.id) &&
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ntohs(tuple->src.u.icmp.id) <= ntohs(max->icmp.id);
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}
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2010-08-02 15:20:54 +00:00
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static void
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2012-08-26 17:14:06 +00:00
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icmp_unique_tuple(const struct nf_nat_l3proto *l3proto,
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struct nf_conntrack_tuple *tuple,
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const struct nf_nat_range *range,
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2006-12-03 06:07:13 +00:00
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enum nf_nat_manip_type maniptype,
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const struct nf_conn *ct)
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{
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static u_int16_t id;
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unsigned int range_size;
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unsigned int i;
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2012-08-26 17:14:06 +00:00
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range_size = ntohs(range->max_proto.icmp.id) -
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ntohs(range->min_proto.icmp.id) + 1;
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2006-12-03 06:07:13 +00:00
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/* If no range specified... */
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2011-12-23 12:59:49 +00:00
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if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED))
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2006-12-03 06:07:13 +00:00
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range_size = 0xFFFF;
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2010-08-02 15:35:49 +00:00
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for (i = 0; ; ++id) {
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2012-08-26 17:14:06 +00:00
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tuple->src.u.icmp.id = htons(ntohs(range->min_proto.icmp.id) +
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2007-02-09 14:24:47 +00:00
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(id % range_size));
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2010-08-02 15:35:49 +00:00
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if (++i == range_size || !nf_nat_used_tuple(tuple, ct))
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2010-08-02 15:20:54 +00:00
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return;
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2006-12-03 06:07:13 +00:00
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}
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2010-08-02 15:20:54 +00:00
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return;
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2006-12-03 06:07:13 +00:00
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}
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2008-04-14 09:15:53 +00:00
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static bool
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2007-10-15 07:53:15 +00:00
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icmp_manip_pkt(struct sk_buff *skb,
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2012-08-26 17:14:06 +00:00
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const struct nf_nat_l3proto *l3proto,
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unsigned int iphdroff, unsigned int hdroff,
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2006-12-03 06:07:13 +00:00
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const struct nf_conntrack_tuple *tuple,
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enum nf_nat_manip_type maniptype)
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{
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struct icmphdr *hdr;
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2007-10-15 07:53:15 +00:00
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if (!skb_make_writable(skb, hdroff + sizeof(*hdr)))
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2008-04-14 09:15:53 +00:00
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return false;
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2006-12-03 06:07:13 +00:00
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2007-10-15 07:53:15 +00:00
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hdr = (struct icmphdr *)(skb->data + hdroff);
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2007-11-29 14:17:11 +00:00
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inet_proto_csum_replace2(&hdr->checksum, skb,
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2015-08-17 20:42:25 +00:00
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hdr->un.echo.id, tuple->src.u.icmp.id, false);
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2006-12-03 06:07:13 +00:00
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hdr->un.echo.id = tuple->src.u.icmp.id;
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2008-04-14 09:15:53 +00:00
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return true;
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2006-12-03 06:07:13 +00:00
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}
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2012-08-26 17:14:06 +00:00
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const struct nf_nat_l4proto nf_nat_l4proto_icmp = {
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.l4proto = IPPROTO_ICMP,
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2006-12-03 06:07:13 +00:00
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.manip_pkt = icmp_manip_pkt,
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.in_range = icmp_in_range,
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.unique_tuple = icmp_unique_tuple,
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2014-06-30 01:19:32 +00:00
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#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
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2012-08-26 17:14:06 +00:00
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.nlattr_to_range = nf_nat_l4proto_nlattr_to_range,
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2006-12-03 06:07:13 +00:00
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#endif
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};
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