TUNNEL: IPv6-over-IPv6 tunnel support.

Fix ip6tunnel.c to be fit with current ip command style.
Unlike other modules currently iptunnel (and ip6tunnel) is not
designed as protocol-independent because of unarranged structure
between IPv4 and IPv6.

Usage: ip -f inet6 tunnel { add | change | del | show } [ NAME ]
          [ remote ADDR local ADDR ] [ dev PHYS_DEV ]
          [ encaplimit ELIM ]
          [ hoplimit HLIM ] [ tc TC ] [ fl FL ]
          [ dscp inherit ]

Where: NAME := STRING
       ADDR := IPV6_ADDRESS
       ELIM := { none | 0..255 }(default=4)
       HLIM := 0..255 (default=64)
       TC   := { 0x0..0xff | inherit }
       FL   := { 0x0..0xfffff | inherit }

Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
diff --git a/ip/iptunnel.c b/ip/iptunnel.c
index 26ae30c..57a6ab0 100644
--- a/ip/iptunnel.c
+++ b/ip/iptunnel.c
@@ -31,6 +31,7 @@
 
 #include "rt_names.h"
 #include "utils.h"
+#include "ip_common.h"
 #include "tunnel.h"
 
 static void usage(void) __attribute__((noreturn));
@@ -455,6 +456,13 @@
 		break;
 	case AF_INET:
 		break;
+	/*
+	 * This is silly enough but we have no easy way to make it
+	 * protocol-independent because of unarranged structure between
+	 * IPv4 and IPv6.
+	 */
+	case AF_INET6:
+		return do_ip6tunnel(argc, argv);
 	default:
 		fprintf(stderr, "Unsupported family:%d\n", preferred_family);
 		exit(-1);