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Diffstat (limited to 'net/ipv4/netfilter/ip_nat_proto_icmp.c')
-rw-r--r--net/ipv4/netfilter/ip_nat_proto_icmp.c115
1 files changed, 115 insertions, 0 deletions
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
+};