patch-2.3.99-pre2 linux/net/ipv4/netfilter/ip_nat_proto_icmp.c
Next file: linux/net/ipv4/netfilter/ip_nat_proto_tcp.c
Previous file: linux/net/ipv4/netfilter/ip_nat_ftp.c
Back to the patch index
Back to the overall index
- 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
+};
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)