ipgre: add support for gretap tunnel

Since kernel support both gre/gretap tunnel, so add support
for gretap appropriately.

Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: Thomas Haller <thaller@redhat.com>

[thaller@redhat.com: modified original patch to move symbols
 in libnl-route-3.sym to proper section]

http://lists.infradead.org/pipermail/libnl/2016-April/002102.html

1 files changed, 56 insertions, 0 deletions

diff --git a/tests/test-create-ipgretap.c b/tests/test-create-ipgretap.c
new file mode 100644
index 00000000..1fe82313
--- /dev/null
+++ b/tests/test-create-ipgretap.c
@@ -0,0 +1,56 @@
+#include <netlink/route/link/ipgre.h>
+#include <netlink-private/netlink.h>
+
+int main(int argc, char *argv[])
+{
+	struct nl_cache *link_cache;
+	struct rtnl_link *link;
+	struct in_addr addr;
+	struct nl_sock *sk;
+	int err, if_index;
+
+	sk = nl_socket_alloc();
+	if ((err = nl_connect(sk, NETLINK_ROUTE)) < 0) {
+		nl_perror(err, "Unable to connect socket");
+		return err;
+	}
+
+	err = rtnl_link_alloc_cache(sk, AF_UNSPEC, &link_cache);
+	if ( err < 0) {
+		nl_perror(err, "Unable to allocate cache");
+		return err;
+	}
+
+	if_index = rtnl_link_name2i(link_cache, "enp0s5");
+	if (!if_index) {
+		fprintf(stderr, "Unable to lookup enp0s5");
+		return -1;
+	}
+
+	link = rtnl_link_ipgretap_alloc();
+	if(!link) {
+		nl_perror(err, "Unable to allocate link");
+		return -1;
+
+	}
+	rtnl_link_set_name(link, "ipgre-tap");
+	rtnl_link_ipgre_set_link(link, if_index);
+
+	inet_pton(AF_INET, "10.211.55.10", &addr.s_addr);
+	rtnl_link_ipgre_set_local(link, addr.s_addr);
+
+	inet_pton(AF_INET, "10.133.6.33", &addr.s_addr);
+	rtnl_link_ipgre_set_remote(link, addr.s_addr);
+
+	rtnl_link_ipgre_set_ttl(link, 64);
+	err = rtnl_link_add(sk, link, NLM_F_CREATE);
+	if (err < 0) {
+		nl_perror(err, "Unable to add link");
+		return err;
+	}
+
+	rtnl_link_put(link);
+	nl_close(sk);
+
+	return 0;
+}