patch-2.3.99-pre2 linux/net/ipv4/netfilter/ip_nat_proto_icmp.c

• Lines: 98
• Date: Fri Mar 17 10:56:20 2000
• Orig file: v2.3.99-pre1/linux/net/ipv4/netfilter/ip_nat_proto_icmp.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.99-pre1/linux/net/ipv4/netfilter/ip_nat_proto_icmp.c linux/net/ipv4/netfilter/ip_nat_proto_icmp.c
@@ -0,0 +1,97 @@
+#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_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 = 0;
+	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 void
+icmp_manip_pkt(struct iphdr *iph, size_t len,
+	       const struct ip_conntrack_manip *manip,
+	       enum ip_nat_manip_type maniptype)
+{
+	struct icmphdr *hdr = (struct icmphdr *)((u_int32_t *)iph + iph->ihl);
+
+	hdr->checksum = ip_nat_cheat_check(hdr->un.echo.id ^ 0xFFFF,
+					   manip->u.icmp.id,
+					   hdr->checksum);
+	hdr->un.echo.id = manip->u.icmp.id;
+}
+
+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
+= { { NULL, NULL }, "ICMP", IPPROTO_ICMP,
+    icmp_manip_pkt,
+    icmp_in_range,
+    icmp_unique_tuple,
+    icmp_print,
+    icmp_print_range
+};