ripngd: retrofit the 'router ripng' command to the new northbound model

* Implement the northbound callbacks associated to the
  '/frr-ripngd:ripngd/instance' YANG path (the code is mostly a copy
  and paste from the original "router ripng" DEFUNs);
* Move ripng_make_socket() out of ripng_create() since creating a
  socket is an error-prone operation and thus needs to be performed
  separately during the NB_EV_PREPARE phase;
* On ripng_create(), fetch the defaults from the frr-ripngd YANG
  model;
* Convert the "[no] router ripng" CLI commands to be dumb wrappers
  around the northbound callbacks;
* On ripng_config_write(), write logic to call all 'cli_show'
  northbound callbacks defined under the '/frr-ripngd:ripngd/instance'
  YANG path.

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

1 files changed, 43 insertions, 0 deletions

diff --git a/ripngd/ripng_cli.c b/ripngd/ripng_cli.c
index b033a39ac..7bdc74220 100644
--- a/ripngd/ripng_cli.c
+++ b/ripngd/ripng_cli.c
@@ -34,6 +34,49 @@
 #include "ripngd/ripng_cli_clippy.c"
 #endif
 
+/*
+ * XPath: /frr-ripngd:ripngd/instance
+ */
+DEFPY_NOSH (router_ripng,
+       router_ripng_cmd,
+       "router ripng",
+       "Enable a routing process\n"
+       "Make RIPng instance command\n")
+{
+	int ret;
+
+	nb_cli_enqueue_change(vty, "/frr-ripngd:ripngd/instance", NB_OP_CREATE,
+			      NULL);
+
+	ret = nb_cli_apply_changes(vty, NULL);
+	if (ret == CMD_SUCCESS)
+		VTY_PUSH_XPATH(RIPNG_NODE, "/frr-ripngd:ripngd/instance");
+
+	return ret;
+}
+
+DEFPY (no_router_ripng,
+       no_router_ripng_cmd,
+       "no router ripng",
+       NO_STR
+       "Enable a routing process\n"
+       "Make RIPng instance command\n")
+{
+	nb_cli_enqueue_change(vty, "/frr-ripngd:ripngd/instance", NB_OP_DELETE,
+			      NULL);
+
+	return nb_cli_apply_changes(vty, NULL);
+}
+
+void cli_show_router_ripng(struct vty *vty, struct lyd_node *dnode,
+			 bool show_defaults)
+{
+	vty_out(vty, "!\n");
+	vty_out(vty, "router ripng\n");
+}
+
 void ripng_cli_init(void)
 {
+	install_element(CONFIG_NODE, &router_ripng_cmd);
+	install_element(CONFIG_NODE, &no_router_ripng_cmd);
 }