ip: add support of 'ip link type ip6tnl'

This patch allows to manage ip6 tunnels via the interface ip link.
The syntax for parameters is the same that 'ip -6 tunnel'.

It also allows to display tunnels parameters with 'ip -details link' or
'ip -details monitor link'.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
diff --git a/ip/ipmonitor.c b/ip/ipmonitor.c
index 4b1d469..d87e58f 100644
--- a/ip/ipmonitor.c
+++ b/ip/ipmonitor.c
@@ -85,6 +85,12 @@
 		print_rule(who, n, arg);
 		return 0;
 	}
+	if (n->nlmsg_type == RTM_NEWNETCONF) {
+		if (prefix_banner)
+			fprintf(fp, "[NETCONF]");
+		print_netconf(who, n, arg);
+		return 0;
+	}
 	if (n->nlmsg_type == 15) {
 		char *tstr;
 		time_t secs = ((__u32*)NLMSG_DATA(n))[0];
@@ -118,6 +124,7 @@
 	int lroute=0;
 	int lprefix=0;
 	int lneigh=0;
+	int lnetconf=0;
 
 	rtnl_close(&rth);
 	ipaddr_reset_filter(1);
@@ -143,6 +150,9 @@
 		} else if (matches(*argv, "neigh") == 0) {
 			lneigh = 1;
 			groups = 0;
+		} else if (matches(*argv, "netconf") == 0) {
+			lnetconf = 1;
+			groups = 0;
 		} else if (strcmp(*argv, "all") == 0) {
 			groups = ~RTMGRP_TC;
 			prefix_banner=1;
@@ -176,6 +186,12 @@
 	if (lneigh) {
 		groups |= nl_mgrp(RTNLGRP_NEIGH);
 	}
+	if (lnetconf) {
+		if (!preferred_family || preferred_family == AF_INET)
+			groups |= nl_mgrp(RTNLGRP_IPV4_NETCONF);
+		if (!preferred_family || preferred_family == AF_INET6)
+			groups |= nl_mgrp(RTNLGRP_IPV6_NETCONF);
+	}
 	if (file) {
 		FILE *fp;
 		fp = fopen(file, "r");