yang, lib: add 'frr-interface.yang' and associated stub callbacks

Introduce frr-interface.yang, which defines a model for managing FRR
interfaces.

Update the 'frr_yang_module_info' array of all daemons that will
implement this module.

Add automatically generated stub callbacks in if.c. These callbacks will
be implemented in the following commit.

Signed-off-by: Renato Westphal <renato@opensourcerouting.org>

babeld/babel_main.c

@@ -138,6 +138,7 @@ struct option longopts[] =
 
 static const struct frr_yang_module_info *babeld_yang_modules[] =
   {
+    &frr_interface_info,
   };
 
 FRR_DAEMON_INFO(babeld, BABELD,

eigrpd/eigrp_main.c

@@ -131,6 +131,7 @@ struct quagga_signal_t eigrp_signals[] = {
 };
 
 static const struct frr_yang_module_info *eigrpd_yang_modules[] = {
+	&frr_interface_info,
 };
 
 FRR_DAEMON_INFO(eigrpd, EIGRP, .vty_port = EIGRP_VTY_PORT,

isisd/isis_main.c

@@ -151,6 +151,7 @@ struct quagga_signal_t isisd_signals[] = {
 };
 
 static const struct frr_yang_module_info *isisd_yang_modules[] = {
+	&frr_interface_info,
 };
 
 #ifdef FABRICD

lib/if.c

@@ -1211,3 +1211,61 @@ void if_link_params_free(struct interface *ifp)
 	XFREE(MTYPE_IF_LINK_PARAMS, ifp->link_params);
 	ifp->link_params = NULL;
 }
+
+/* ------- Northbound callbacks ------- */
+
+/*
+ * XPath: /frr-interface:lib/interface
+ */
+static int lib_interface_create(enum nb_event event,
+				const struct lyd_node *dnode,
+				union nb_resource *resource)
+{
+	/* TODO: implement me. */
+	return NB_OK;
+}
+
+static int lib_interface_delete(enum nb_event event,
+				const struct lyd_node *dnode)
+{
+	/* TODO: implement me. */
+	return NB_OK;
+}
+
+/*
+ * XPath: /frr-interface:lib/interface/description
+ */
+static int lib_interface_description_modify(enum nb_event event,
+					    const struct lyd_node *dnode,
+					    union nb_resource *resource)
+{
+	/* TODO: implement me. */
+	return NB_OK;
+}
+
+static int lib_interface_description_delete(enum nb_event event,
+					    const struct lyd_node *dnode)
+{
+	/* TODO: implement me. */
+	return NB_OK;
+}
+
+/* clang-format off */
+const struct frr_yang_module_info frr_interface_info = {
+	.name = "frr-interface",
+	.nodes = {
+		{
+			.xpath = "/frr-interface:lib/interface",
+			.cbs.create = lib_interface_create,
+			.cbs.delete = lib_interface_delete,
+		},
+		{
+			.xpath = "/frr-interface:lib/interface/description",
+			.cbs.modify = lib_interface_description_modify,
+			.cbs.delete = lib_interface_description_delete,
+		},
+		{
+			.xpath = NULL,
+		},
+	}
+};

lib/if.h

@@ -497,7 +497,6 @@ extern bool if_is_loopback_or_vrf(struct interface *ifp);
 extern int if_is_broadcast(struct interface *);
 extern int if_is_pointopoint(struct interface *);
 extern int if_is_multicast(struct interface *);
-extern void if_cmd_init(void);
 struct vrf;
 extern void if_terminate(struct vrf *vrf);
 extern void if_dump_all(void);
@@ -534,4 +533,8 @@ struct nbr_connected *nbr_connected_check(struct interface *, struct prefix *);
 struct if_link_params *if_link_params_get(struct interface *);
 void if_link_params_free(struct interface *);
 
+/* Northbound. */
+extern void if_cmd_init(void);
+extern const struct frr_yang_module_info frr_interface_info;
+
 #endif /* _ZEBRA_IF_H */

nhrpd/nhrp_main.c

@@ -117,6 +117,7 @@ static struct quagga_signal_t sighandlers[] = {
 };
 
 static const struct frr_yang_module_info *nhrpd_yang_modules[] = {
+	&frr_interface_info,
 };
 
 FRR_DAEMON_INFO(nhrpd, NHRP, .vty_port = NHRP_VTY_PORT,

ospf6d/ospf6_main.c

@@ -163,6 +163,7 @@ struct quagga_signal_t ospf6_signals[] = {
 };
 
 static const struct frr_yang_module_info *ospf6d_yang_modules[] = {
+	&frr_interface_info,
 };
 
 FRR_DAEMON_INFO(ospf6d, OSPF6, .vty_port = OSPF6_VTY_PORT,

ospfd/ospf_main.c

@@ -124,6 +124,7 @@ struct quagga_signal_t ospf_signals[] = {
 };
 
 static const struct frr_yang_module_info *ospfd_yang_modules[] = {
+	&frr_interface_info,
 };
 
 FRR_DAEMON_INFO(ospfd, OSPF, .vty_port = OSPF_VTY_PORT,

pbrd/pbr_main.c

@@ -112,6 +112,7 @@ struct quagga_signal_t pbr_signals[] = {
 #define PBR_VTY_PORT 2615
 
 static const struct frr_yang_module_info *pbrd_yang_modules[] = {
+	&frr_interface_info,
 };
 
 FRR_DAEMON_INFO(pbrd, PBR, .vty_port = PBR_VTY_PORT,

pimd/pim_main.c

@@ -72,6 +72,7 @@ struct zebra_privs_t pimd_privs = {
 	.cap_num_i = 0};
 
 static const struct frr_yang_module_info *pimd_yang_modules[] = {
+	&frr_interface_info,
 };
 
 FRR_DAEMON_INFO(pimd, PIM, .vty_port = PIMD_VTY_PORT,

ripd/rip_main.c

@@ -120,6 +120,7 @@ static struct quagga_signal_t ripd_signals[] = {
 };
 
 static const struct frr_yang_module_info *ripd_yang_modules[] = {
+	&frr_interface_info,
 };
 
 FRR_DAEMON_INFO(ripd, RIP, .vty_port = RIP_VTY_PORT,

ripngd/ripng_main.c

@@ -119,6 +119,7 @@ struct quagga_signal_t ripng_signals[] = {
 };
 
 static const struct frr_yang_module_info *ripngd_yang_modules[] = {
+	&frr_interface_info,
 };
 
 FRR_DAEMON_INFO(ripngd, RIPNG, .vty_port = RIPNG_VTY_PORT,

yang/frr-interface.yang

@@ -0,0 +1,46 @@
+module frr-interface {
+  yang-version 1.1;
+  namespace "http://frrouting.org/yang/interface";
+  prefix frr-interface;
+
+  organization
+    "Free Range Routing";
+  contact
+    "FRR Users List:       <mailto:frog@lists.frrouting.org>
+     FRR Development List: <mailto:dev@lists.frrouting.org>";
+  description
+    "This module defines a model for managing FRR interfaces.";
+
+  revision 2018-03-28 {
+    description
+      "Initial revision.";
+  }
+
+  container lib {
+    list interface {
+      key "name vrf";
+      description
+        "Interface.";
+
+      leaf name {
+        type string {
+          length "1..16";
+        }
+        description
+          "Interface name.";
+      }
+      leaf vrf {
+        type string {
+          length "1..36";
+        }
+        description
+          "VRF this interface is associated with.";
+      }
+      leaf description {
+        type string;
+        description
+          "Interface description.";
+      }
+    }
+  }
+}

yang/subdir.am

@@ -1 +1,2 @@
 dist_yangmodels_DATA += yang/frr-module-translator.yang
+dist_yangmodels_DATA += yang/frr-interface.yang

zebra/main.c

@@ -207,6 +207,7 @@ struct quagga_signal_t zebra_signals[] = {
 };
 
 static const struct frr_yang_module_info *zebra_yang_modules[] = {
+	&frr_interface_info,
 };
 
 FRR_DAEMON_INFO(