[nh-encap] Add parsing support to populate a struct rtnl_nh_encap

There is support for parsing and populating rtnl_nexthop's encap.
However, not for rtnl_nh's encapsulation.

Refactor this and make it such that the parsing code for both is reused.

Signed-off-by: Christoph Paasch <[email protected]>

Author: cpaasch-oai

lib/route/nexthop-encap.h

@@ -1,11 +1,13 @@
 #ifndef NETLINK_NEXTHOP_ENCAP_H_
 #define NETLINK_NEXTHOP_ENCAP_H_
 
+struct rtnl_nh_encap;
+
 struct nh_encap_ops {
 	uint16_t encap_type;
 
 	int (*build_msg)(struct nl_msg *msg, void *priv);
-	int (*parse_msg)(struct nlattr *nla, struct rtnl_nexthop *rtnh);
+	int (*parse_msg)(struct nlattr *nla, struct rtnl_nh_encap **encap_out);
 
 	int (*compare)(void *a, void *b);
 	void *(*clone)(void *priv);
@@ -14,13 +16,11 @@ struct nh_encap_ops {
 	void (*destructor)(void *priv);
 };
 
-struct rtnl_nh_encap;
-
 /*
  * generic nexthop encap
  */
 int nh_encap_parse_msg(struct nlattr *encap, struct nlattr *encap_type,
-		       struct rtnl_nexthop *rtnh);
+		       struct rtnl_nh_encap **encap_out);
 int nh_encap_build_msg(struct nl_msg *msg, struct rtnl_nh_encap *rtnh_encap);
 
 void nh_encap_dump(struct rtnl_nh_encap *rtnh_encap, struct nl_dump_params *dp);

lib/route/nexthop_encap.c

@@ -72,7 +72,7 @@ int nh_encap_build_msg(struct nl_msg *msg, struct rtnl_nh_encap *rtnh_encap)
 }
 
 int nh_encap_parse_msg(struct nlattr *encap, struct nlattr *encap_type,
-		       struct rtnl_nexthop *rtnh)
+		       struct rtnl_nh_encap **encap_out)
 {
 	uint16_t e_type = nla_get_u16(encap_type);
 
@@ -91,7 +91,10 @@ int nh_encap_parse_msg(struct nlattr *encap, struct nlattr *encap_type,
 		return -NLE_MSGTYPE_NOSUPPORT;
 	}
 
-	return lwtunnel_encap_types[e_type].ops->parse_msg(encap, rtnh);
+	if (!lwtunnel_encap_types[e_type].ops->parse_msg)
+		return -NLE_MSGTYPE_NOSUPPORT;
+
+	return lwtunnel_encap_types[e_type].ops->parse_msg(encap, encap_out);
 }
 
 int nh_encap_compare(struct rtnl_nh_encap *a, struct rtnl_nh_encap *b)

lib/route/nh_encap_mpls.c

@@ -72,7 +72,8 @@ static struct nla_policy mpls_encap_policy[MPLS_IPTUNNEL_MAX + 1] = {
 	[MPLS_IPTUNNEL_TTL] = { .type = NLA_U8 },
 };
 
-static int mpls_encap_parse_msg(struct nlattr *nla, struct rtnl_nexthop *nh)
+static int mpls_encap_parse_msg(struct nlattr *nla,
+				struct rtnl_nh_encap **encap_out)
 {
 	_nl_auto_rtnl_nh_encap struct rtnl_nh_encap *nh_encap = NULL;
 	_nl_auto_nl_addr struct nl_addr *labels = NULL;
@@ -102,9 +103,7 @@ static int mpls_encap_parse_msg(struct nlattr *nla, struct rtnl_nexthop *nh)
 	if (err < 0)
 		return err;
 
-	err = rtnl_route_nh_set_encap(nh, _nl_steal_pointer(&nh_encap));
-	if (err < 0)
-		return err;
+	*encap_out = _nl_steal_pointer(&nh_encap);
 
 	return 0;
 }

lib/route/route_obj.c

@@ -1149,9 +1149,17 @@ static int parse_multipath(struct rtnl_route *route, struct nlattr *attr)
 			}
 
 			if (ntb[RTA_ENCAP] && ntb[RTA_ENCAP_TYPE]) {
+				_nl_auto_rtnl_nh_encap struct rtnl_nh_encap
+					*encap = NULL;
+
 				err = nh_encap_parse_msg(ntb[RTA_ENCAP],
 							 ntb[RTA_ENCAP_TYPE],
-							 nh);
+							 &encap);
+				if (err < 0)
+					return err;
+
+				err = rtnl_route_nh_set_encap(
+					nh, _nl_steal_pointer(&encap));
 				if (err < 0)
 					return err;
 			}
@@ -1358,11 +1366,18 @@ int rtnl_route_parse(struct nlmsghdr *nlh, struct rtnl_route **result)
 	}
 
 	if (tb[RTA_ENCAP] && tb[RTA_ENCAP_TYPE]) {
+		_nl_auto_rtnl_nh_encap struct rtnl_nh_encap *encap = NULL;
+
 		if (!old_nh && !(old_nh = rtnl_route_nh_alloc()))
 			return -NLE_NOMEM;
 
-		err = nh_encap_parse_msg(tb[RTA_ENCAP],
-					 tb[RTA_ENCAP_TYPE], old_nh);
+		err = nh_encap_parse_msg(tb[RTA_ENCAP], tb[RTA_ENCAP_TYPE],
+					 &encap);
+		if (err < 0)
+			return err;
+
+		err = rtnl_route_nh_set_encap(old_nh,
+					      _nl_steal_pointer(&encap));
 		if (err < 0)
 			return err;
 	}