From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@ppc970.osdl.org>
Date: Sat, 16 Apr 2005 15:20:36 -0700
Subject: Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
---
 net/ipv4/netfilter/ip_nat_proto_icmp.c | 115 +++++++++++++++++++++++++++++++++
 1 file changed, 115 insertions(+)
 create mode 100644 net/ipv4/netfilter/ip_nat_proto_icmp.c

(limited to 'net/ipv4/netfilter/ip_nat_proto_icmp.c')

diff --git a/net/ipv4/netfilter/ip_nat_proto_icmp.c b/net/ipv4/netfilter/ip_nat_proto_icmp.c
new file mode 100644
index 00000000000..a558cf0eee8
--- /dev/null
+++ b/net/ipv4/netfilter/ip_nat_proto_icmp.c
@@ -0,0 +1,115 @@
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * 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/init.h>
+#include <linux/netfilter.h>
+#include <linux/ip.h>
+#include <linux/icmp.h>
+#include <linux/if.h>
+
+#include <linux/netfilter_ipv4/ip_nat.h>
+#include <linux/netfilter_ipv4/ip_nat_core.h>
+#include <linux/netfilter_ipv4/ip_nat_rule.h>
+#include <linux/netfilter_ipv4/ip_nat_protocol.h>
+
+static int
+icmp_in_range(const struct ip_conntrack_tuple *tuple,
+	      enum ip_nat_manip_type maniptype,
+	      const union ip_conntrack_manip_proto *min,
+	      const union ip_conntrack_manip_proto *max)
+{
+	return (tuple->src.u.icmp.id >= min->icmp.id
+		&& tuple->src.u.icmp.id <= max->icmp.id);
+}
+
+static int
+icmp_unique_tuple(struct ip_conntrack_tuple *tuple,
+		  const struct ip_nat_range *range,
+		  enum ip_nat_manip_type maniptype,
+		  const struct ip_conntrack *conntrack)
+{
+	static u_int16_t id;
+	unsigned int range_size
+		= (unsigned int)range->max.icmp.id - range->min.icmp.id + 1;
+	unsigned int i;
+
+	/* If no range specified... */
+	if (!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED))
+		range_size = 0xFFFF;
+
+	for (i = 0; i < range_size; i++, id++) {
+		tuple->src.u.icmp.id = range->min.icmp.id + (id % range_size);
+		if (!ip_nat_used_tuple(tuple, conntrack))
+			return 1;
+	}
+	return 0;
+}
+
+static int
+icmp_manip_pkt(struct sk_buff **pskb,
+	       unsigned int iphdroff,
+	       const struct ip_conntrack_tuple *tuple,
+	       enum ip_nat_manip_type maniptype)
+{
+	struct iphdr *iph = (struct iphdr *)((*pskb)->data + iphdroff);
+	struct icmphdr *hdr;
+	unsigned int hdroff = iphdroff + iph->ihl*4;
+
+	if (!skb_ip_make_writable(pskb, hdroff + sizeof(*hdr)))
+		return 0;
+
+	hdr = (struct icmphdr *)((*pskb)->data + hdroff);
+
+	hdr->checksum = ip_nat_cheat_check(hdr->un.echo.id ^ 0xFFFF,
+					    tuple->src.u.icmp.id,
+					    hdr->checksum);
+	hdr->un.echo.id = tuple->src.u.icmp.id;
+	return 1;
+}
+
+static unsigned int
+icmp_print(char *buffer,
+	   const struct ip_conntrack_tuple *match,
+	   const struct ip_conntrack_tuple *mask)
+{
+	unsigned int len = 0;
+
+	if (mask->src.u.icmp.id)
+		len += sprintf(buffer + len, "id=%u ",
+			       ntohs(match->src.u.icmp.id));
+
+	if (mask->dst.u.icmp.type)
+		len += sprintf(buffer + len, "type=%u ",
+			       ntohs(match->dst.u.icmp.type));
+
+	if (mask->dst.u.icmp.code)
+		len += sprintf(buffer + len, "code=%u ",
+			       ntohs(match->dst.u.icmp.code));
+
+	return len;
+}
+
+static unsigned int
+icmp_print_range(char *buffer, const struct ip_nat_range *range)
+{
+	if (range->min.icmp.id != 0 || range->max.icmp.id != 0xFFFF)
+		return sprintf(buffer, "id %u-%u ",
+			       ntohs(range->min.icmp.id),
+			       ntohs(range->max.icmp.id));
+	else return 0;
+}
+
+struct ip_nat_protocol ip_nat_protocol_icmp
+= { "ICMP", IPPROTO_ICMP,
+    icmp_manip_pkt,
+    icmp_in_range,
+    icmp_unique_tuple,
+    icmp_print,
+    icmp_print_range
+};
-- 
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