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

6 files changed, 160 insertions, 5 deletions

diff --git a/include/netlink/route/link/ipgre.h b/include/netlink/route/link/ipgre.h
index 5a0a295..647c3cf 100644
--- a/include/netlink/route/link/ipgre.h
+++ b/include/netlink/route/link/ipgre.h
@@ -20,7 +20,9 @@ extern "C" {
 #endif
 
 	extern struct rtnl_link *rtnl_link_ipgre_alloc(void);
+	extern struct rtnl_link *rtnl_link_ipgretap_alloc(void);
 	extern int rtnl_link_ipgre_add(struct nl_sock *sk, const char *name);
+	extern int rtnl_link_ipgretap_add(struct nl_sock *sk, const char *name);
 
 	extern int rtnl_link_ipgre_set_link(struct rtnl_link *link,  uint32_t index);
 	extern uint32_t rtnl_link_ipgre_get_link(struct rtnl_link *link);
diff --git a/lib/route/link/ipgre.c b/lib/route/link/ipgre.c
index 7889d11..7be311a 100644
--- a/lib/route/link/ipgre.c
+++ b/lib/route/link/ipgre.c
@@ -315,6 +315,27 @@ static int ipgre_clone(struct rtnl_link *dst, struct rtnl_link *src)
 	return 0;
 }
 
+static int ipgretap_clone(struct rtnl_link *dst, struct rtnl_link *src)
+{
+	struct ipgre_info *ipgre_dst, *ipgre_src = src->l_info;
+	int err;
+
+	dst->l_info = NULL;
+
+	err = rtnl_link_set_type(dst, "gretap");
+	if (err < 0)
+		return err;
+
+	ipgre_dst = dst->l_info;
+
+	if (!ipgre_dst || !ipgre_src)
+		BUG();
+
+	memcpy(ipgre_dst, ipgre_src, sizeof(struct ipgre_info));
+
+	return 0;
+}
+
 static struct rtnl_link_info_ops ipgre_info_ops = {
 	.io_name                = "gre",
 	.io_alloc               = ipgre_alloc,
@@ -328,10 +349,24 @@ static struct rtnl_link_info_ops ipgre_info_ops = {
 	.io_free                = ipgre_free,
 };
 
-#define IS_IPGRE_LINK_ASSERT(link)                                          \
-        if ((link)->l_info_ops != &ipgre_info_ops) {                        \
-                APPBUG("Link is not a ipgre link. set type \"gre\" first.");\
-                return -NLE_OPNOTSUPP;                                      \
+static struct rtnl_link_info_ops ipgretap_info_ops = {
+	.io_name                = "gretap",
+	.io_alloc               = ipgre_alloc,
+	.io_parse               = ipgre_parse,
+	.io_dump = {
+		[NL_DUMP_LINE]  = ipgre_dump_line,
+		[NL_DUMP_DETAILS] = ipgre_dump_details,
+	},
+	.io_clone               = ipgretap_clone,
+	.io_put_attrs           = ipgre_put_attrs,
+	.io_free                = ipgre_free,
+};
+
+#define IS_IPGRE_LINK_ASSERT(link)                                                 \
+        if ((link)->l_info_ops != &ipgre_info_ops &&                               \
+            (link)->l_info_ops != &ipgretap_info_ops) {                            \
+                APPBUG("Link is not a ipgre link. set type \"gre/gretap\" first.");\
+                return -NLE_OPNOTSUPP;                                             \
         }
 
 struct rtnl_link *rtnl_link_ipgre_alloc(void)
@@ -362,8 +397,9 @@ int rtnl_link_is_ipgre(struct rtnl_link *link)
 {
 	return link->l_info_ops && !strcmp(link->l_info_ops->io_name, "gre");
 }
+
 /**
- * Create a new ipip tunnel device
+ * Create a new IPGRE tunnel device
  * @arg sock            netlink socket
  * @arg name            name of the tunnel deviceL
  *
@@ -387,6 +423,61 @@ int rtnl_link_ipgre_add(struct nl_sock *sk, const char *name)
 
 	return err;
 }
+
+struct rtnl_link *rtnl_link_ipgretap_alloc(void)
+{
+	struct rtnl_link *link;
+	int err;
+
+	link = rtnl_link_alloc();
+	if (!link)
+		return NULL;
+
+	err = rtnl_link_set_type(link, "gretap");
+	if (err < 0) {
+		rtnl_link_put(link);
+		return NULL;
+	}
+
+	return link;
+}
+
+/**
+ * Check if link is a IPGRETAP link
+ * @arg link            Link object
+ *
+ * @return True if link is a IPGRETAP link, otherwise 0 is returned.
+ */
+int rtnl_link_is_ipgretap(struct rtnl_link *link)
+{
+	return link->l_info_ops && !strcmp(link->l_info_ops->io_name, "gretap");
+}
+/**
+ * Create a new IPGRETAP tunnel device
+ * @arg sock            netlink socket
+ * @arg name            name of the tunnel deviceL
+ *
+ * Creates a new IPGRETAP tunnel device in the kernel
+ * @return 0 on success or a negative error code
+ */
+int rtnl_link_ipgretap_add(struct nl_sock *sk, const char *name)
+{
+	struct rtnl_link *link;
+	int err;
+
+	link = rtnl_link_ipgretap_alloc();
+	if (!link)
+		return -NLE_NOMEM;
+
+	if(name)
+		rtnl_link_set_name(link, name);
+
+	err = rtnl_link_add(sk, link, NLM_F_CREATE);
+	rtnl_link_put(link);
+
+	return err;
+}
+
 /**
  * Set IPGRE tunnel interface index
  * @arg link            Link object
@@ -730,9 +821,11 @@ uint8_t rtnl_link_get_pmtudisc(struct rtnl_link *link)
 static void __init ipgre_init(void)
 {
 	rtnl_link_register_info(&ipgre_info_ops);
+	rtnl_link_register_info(&ipgretap_info_ops);
 }
 
 static void __exit ipgre_exit(void)
 {
 	rtnl_link_unregister_info(&ipgre_info_ops);
+	rtnl_link_unregister_info(&ipgretap_info_ops);
 }
diff --git a/libnl-route-3.sym b/libnl-route-3.sym
index 1fd205b..cd2b824 100644
--- a/libnl-route-3.sym
+++ b/libnl-route-3.sym
@@ -893,6 +893,8 @@ global:
 	rtnl_link_bridge_pvid;
 	rtnl_link_is_macvtap;
 	rtnl_link_is_vrf;
+	rtnl_link_ipgretap_add;
+	rtnl_link_ipgretap_alloc;
 	rtnl_link_macvtap_alloc;
 	rtnl_link_macvtap_flags2str;
 	rtnl_link_macvtap_get_flags;
diff --git a/tests/.gitignore b/tests/.gitignore
index d11450b..9666f27 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -10,6 +10,7 @@
 /test-create-ifb
 /test-create-ip6tnl
 /test-create-ipgre
+/test-create-ipgretap
 /test-create-ipip
 /test-create-ipvlan
 /test-create-ipvti
diff --git a/tests/Makefile.am b/tests/Makefile.am
index e764635..5cf43e9 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -32,6 +32,7 @@ check_PROGRAMS = \
 	test-create-bridge \
 	test-create-ip6tnl \
 	test-create-ipgre \
+	test-create-ipgretap \
 	test-create-ipip \
 	test-create-ipvti \
 	test-create-macvlan \
diff --git a/tests/test-create-ipgretap.c b/tests/test-create-ipgretap.c
new file mode 100644
index 0000000..1fe8231
--- /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;
+}