mgmtd: Add MGMT Frontend Interface Framework

This commit introduces the Frontend Interface which can be used
by front-end management clients like Netconf server, Restconf
Server and CLI to interact with new FRR Management daemon (MGMTd)
to access and sometimes modify FRR management data.

This commit includes the following functionalities in the changeset:
1. Add new Frontend server for clients connect to.
2. Add a C-based Frontend client library which can be used by Frontend
   clients to communicate with MGMTd via the Frontend interface.
3. Maintain a frontend adapter for each connection from an appropriate
   Frontend client to facilitate client requests and track one or more
   client sessions across it.
4. Define the protobuf message format for messages to be exchanged
   between MGMTd Frontend module and the Frontend client.
5. This changeset also introduces an instance of MGMT Frontend client
   embedded within the lib/vty module that can be leveraged by any FRR
   daemon to connect to MGMTd's Frontend interface. The same has been
   integrated with and initialized within the MGMTd daemon's process
   context to implement a bunch of 'set-config', 'commit-apply',
   'get-config' and 'get-data' commands via VTYSH

Co-authored-by: Pushpasis Sarkar <pushpasis@gmail.com>
Co-authored-by: Abhinay Ramesh <rabhinay@vmware.com>
Co-authored-by: Ujwal P <ujwalp@vmware.com>
Signed-off-by: Yash Ranjan <ranjany@vmware.com>

1 files changed, 132 insertions, 50 deletions

diff --git a/mgmtd/mgmt_vty.c b/mgmtd/mgmt_vty.c
index 3070b754fa..4efd38e970 100644
--- a/mgmtd/mgmt_vty.c
+++ b/mgmtd/mgmt_vty.c
@@ -11,11 +11,24 @@
 #include "command.h"
 #include "json.h"
 #include "mgmtd/mgmt.h"
+#include "mgmtd/mgmt_fe_server.h"
+#include "mgmtd/mgmt_fe_adapter.h"
 #include "mgmtd/mgmt_ds.h"
 
-#ifndef VTYSH_EXTRACT_PL
 #include "mgmtd/mgmt_vty_clippy.c"
-#endif
+
+DEFPY(show_mgmt_fe_adapter, show_mgmt_fe_adapter_cmd,
+      "show mgmt frontend-adapter all [detail$detail]",
+      SHOW_STR
+      MGMTD_STR
+      MGMTD_FE_ADAPTER_STR
+      "Display all Frontend Adapters\n"
+      "Display more details\n")
+{
+	mgmt_fe_adapter_status_write(vty, !!detail);
+
+	return CMD_SUCCESS;
+}
 
 DEFPY(show_mgmt_ds,
       show_mgmt_ds_cmd,
@@ -44,32 +57,124 @@ DEFPY(show_mgmt_ds,
 	return CMD_SUCCESS;
 }
 
+DEFPY(mgmt_commit,
+      mgmt_commit_cmd,
+      "mgmt commit <check|apply|abort>$type",
+      MGMTD_STR
+      "Commit action\n"
+      "Validate the set of config commands\n"
+      "Validate and apply the set of config commands\n"
+      "Abort and drop the set of config commands recently added\n")
+{
+	bool validate_only = type[0] == 'c';
+	bool abort = type[1] == 'b';
+
+	if (vty_mgmt_send_commit_config(vty, validate_only, abort) != 0)
+		return CMD_WARNING_CONFIG_FAILED;
+	return CMD_SUCCESS;
+}
+
+DEFPY(mgmt_set_config_data, mgmt_set_config_data_cmd,
+      "mgmt set-config WORD$path VALUE",
+      MGMTD_STR
+      "Set configuration data\n"
+      "XPath expression specifying the YANG data path\n"
+      "Value of the data to set\n")
+{
+	strlcpy(vty->cfg_changes[0].xpath, path,
+		sizeof(vty->cfg_changes[0].xpath));
+	vty->cfg_changes[0].value = value;
+	vty->cfg_changes[0].operation = NB_OP_CREATE;
+	vty->num_cfg_changes = 1;
+
+	vty->no_implicit_commit = true;
+	vty_mgmt_send_config_data(vty);
+	vty->no_implicit_commit = false;
+	return CMD_SUCCESS;
+}
+
+DEFPY(mgmt_delete_config_data, mgmt_delete_config_data_cmd,
+      "mgmt delete-config WORD$path",
+      MGMTD_STR
+      "Delete configuration data\n"
+      "XPath expression specifying the YANG data path\n")
+{
+
+	strlcpy(vty->cfg_changes[0].xpath, path,
+		sizeof(vty->cfg_changes[0].xpath));
+	vty->cfg_changes[0].value = NULL;
+	vty->cfg_changes[0].operation = NB_OP_DESTROY;
+	vty->num_cfg_changes = 1;
+
+	vty->no_implicit_commit = true;
+	vty_mgmt_send_config_data(vty);
+	vty->no_implicit_commit = false;
+	return CMD_SUCCESS;
+}
+
+DEFPY(show_mgmt_get_config, show_mgmt_get_config_cmd,
+      "show mgmt get-config [candidate|operational|running]$dsname WORD$path",
+      SHOW_STR MGMTD_STR
+      "Get configuration data from a specific configuration datastore\n"
+      "Candidate datastore (default)\n"
+      "Operational datastore\n"
+      "Running datastore\n"
+      "XPath expression specifying the YANG data path\n")
+{
+	const char *xpath_list[VTY_MAXCFGCHANGES] = {0};
+	Mgmtd__DatastoreId datastore = MGMTD_DS_CANDIDATE;
+
+	if (dsname)
+		datastore = mgmt_ds_name2id(dsname);
+
+	xpath_list[0] = path;
+	vty_mgmt_send_get_config(vty, datastore, xpath_list, 1);
+	return CMD_SUCCESS;
+}
+
+DEFPY(show_mgmt_get_data, show_mgmt_get_data_cmd,
+      "show mgmt get-data [candidate|operational|running]$dsname WORD$path",
+      SHOW_STR MGMTD_STR
+      "Get data from a specific datastore\n"
+      "Candidate datastore\n"
+      "Operational datastore (default)\n"
+      "Running datastore\n"
+      "XPath expression specifying the YANG data path\n")
+{
+	const char *xpath_list[VTY_MAXCFGCHANGES] = {0};
+	Mgmtd__DatastoreId datastore = MGMTD_DS_OPERATIONAL;
+
+	if (dsname)
+		datastore = mgmt_ds_name2id(dsname);
+
+	xpath_list[0] = path;
+	vty_mgmt_send_get_data(vty, datastore, xpath_list, 1);
+	return CMD_SUCCESS;
+}
+
 DEFPY(show_mgmt_dump_data,
       show_mgmt_dump_data_cmd,
-      "show mgmt datastore-contents WORD$dsname [xpath WORD$path] [file WORD$filepath] <json|xml>$fmt",
+      "show mgmt datastore-contents [candidate|operational|running]$dsname [xpath WORD$path] [file WORD$filepath] <json|xml>$fmt",
       SHOW_STR
       MGMTD_STR
       "Get Datastore contents from a specific datastore\n"
-      "<candidate | running | operational>\n"
+      "Candidate datastore (default)\n"
+      "Operational datastore\n"
+      "Running datastore\n"
       "XPath expression specifying the YANG data path\n"
       "XPath string\n"
       "Dump the contents to a file\n"
       "Full path of the file\n"
-      "json|xml\n")
+      "json output\n"
+      "xml output\n")
 {
-	enum mgmt_datastore_id datastore = MGMTD_DS_CANDIDATE;
 	struct mgmt_ds_ctx *ds_ctx;
+	Mgmtd__DatastoreId datastore = MGMTD_DS_CANDIDATE;
 	LYD_FORMAT format = fmt[0] == 'j' ? LYD_JSON : LYD_XML;
 	FILE *f = NULL;
 
-	datastore = mgmt_ds_name2id(dsname);
-
-	if (datastore == MGMTD_DS_NONE) {
-		vty_out(vty,
-			"DS Name %s does not matches any existing datastore\n",
-			dsname);
-		return CMD_SUCCESS;
-	}
+	if (datastore)
+		datastore = mgmt_ds_name2id(dsname);
 
 	ds_ctx = mgmt_ds_get_ctx_by_id(mm, datastore);
 	if (!ds_ctx) {
@@ -96,18 +201,16 @@ DEFPY(show_mgmt_dump_data,
 
 DEFPY(mgmt_load_config,
       mgmt_load_config_cmd,
-      "mgmt load-config file WORD$filepath <merge|replace>",
+      "mgmt load-config WORD$filepath <merge|replace>$type",
       MGMTD_STR
       "Load configuration onto Candidate Datastore\n"
-      "Read the configuration from a file\n"
       "Full path of the file\n"
       "Merge configuration with contents of Candidate Datastore\n"
       "Replace the existing contents of Candidate datastore\n")
 {
-	bool merge = false;
-	int idx_merge = 4;
-	int ret;
+	bool merge = type[0] == 'm' ? true : false;
 	struct mgmt_ds_ctx *ds_ctx;
+	int ret;
 
 	if (access(filepath, F_OK) == -1) {
 		vty_out(vty, "ERROR: File %s : %s\n", filepath,
@@ -121,17 +224,6 @@ DEFPY(mgmt_load_config,
 		return CMD_ERR_NO_MATCH;
 	}
 
-	if (strncmp(argv[idx_merge]->arg, "merge", sizeof("merge")) == 0)
-		merge = true;
-	else if (strncmp(argv[idx_merge]->arg, "replace", sizeof("replace"))
-		 == 0)
-		merge = false;
-	else {
-		vty_out(vty, "Chosen option: %s not valid\n",
-			argv[idx_merge]->arg);
-		return CMD_SUCCESS;
-	}
-
 	ret = mgmt_ds_load_config_from_file(ds_ctx, filepath, merge);
 	if (ret != 0)
 		vty_out(vty, "Error with parsing the file with error code %d\n",
@@ -141,33 +233,17 @@ DEFPY(mgmt_load_config,
 
 DEFPY(mgmt_save_config,
       mgmt_save_config_cmd,
-      "mgmt save-config datastore WORD$dsname file WORD$filepath",
+      "mgmt save-config <candidate|running>$dsname WORD$filepath",
       MGMTD_STR
       "Save configuration from datastore\n"
-      "Datastore keyword\n"
-      "<candidate|running>\n"
-      "Write the configuration to a file\n"
+      "Candidate datastore\n"
+      "Running datastore\n"
       "Full path of the file\n")
 {
+	Mgmtd__DatastoreId datastore = mgmt_ds_name2id(dsname);
 	struct mgmt_ds_ctx *ds_ctx;
-	enum mgmt_datastore_id datastore;
 	FILE *f;
 
-	datastore = mgmt_ds_name2id(dsname);
-
-	if (datastore == MGMTD_DS_NONE) {
-		vty_out(vty,
-			"DS Name %s does not matches any existing datastore\n",
-			dsname);
-		return CMD_SUCCESS;
-	}
-
-	if (datastore != MGMTD_DS_CANDIDATE && datastore != MGMTD_DS_RUNNING) {
-		vty_out(vty, "DS Name %s is not a configuration datastore\n",
-			dsname);
-		return CMD_SUCCESS;
-	}
-
 	ds_ctx = mgmt_ds_get_ctx_by_id(mm, datastore);
 	if (!ds_ctx) {
 		vty_out(vty, "ERROR: Could not access the '%s' datastore!\n",
@@ -257,9 +333,15 @@ void mgmt_vty_init(void)
 {
 	install_node(&debug_node);
 
+	install_element(VIEW_NODE, &show_mgmt_fe_adapter_cmd);
 	install_element(VIEW_NODE, &show_mgmt_ds_cmd);
+	install_element(VIEW_NODE, &show_mgmt_get_config_cmd);
+	install_element(VIEW_NODE, &show_mgmt_get_data_cmd);
 	install_element(VIEW_NODE, &show_mgmt_dump_data_cmd);
 
+	install_element(CONFIG_NODE, &mgmt_commit_cmd);
+	install_element(CONFIG_NODE, &mgmt_set_config_data_cmd);
+	install_element(CONFIG_NODE, &mgmt_delete_config_data_cmd);
 	install_element(CONFIG_NODE, &mgmt_load_config_cmd);
 	install_element(CONFIG_NODE, &mgmt_save_config_cmd);