add ietf-yang-library support

lib/northbound.h

@@ -1716,6 +1716,7 @@ extern void nb_terminate(void);
 
 extern void nb_oper_init(struct event_loop *loop);
 extern void nb_oper_terminate(void);
+extern bool nb_oper_is_yang_lib_query(const char *xpath);
 
 #ifdef __cplusplus
 }

lib/northbound_oper.c

@@ -1741,6 +1741,16 @@ static enum nb_error nb_op_walk_start(struct nb_op_yield_state *ys)
 	return __walk(ys, false);
 }
 
+bool nb_oper_is_yang_lib_query(const char *xpath)
+{
+	const char *libstr = "/ietf-yang-library:";
+	const unsigned long liblen = strlen(libstr);
+
+	if (strncmp(libstr, xpath, liblen))
+		return false;
+
+	return strlen(xpath) > liblen;
+}
 
 void *nb_oper_walk(const char *xpath, struct yang_translator *translator,
 		   uint32_t flags, bool should_batch, nb_oper_data_cb cb,

mgmtd/mgmt.c

@@ -57,6 +57,9 @@ void mgmt_init(void)
 	/* Initialize MGMTD Transaction module */
 	mgmt_txn_init(mm, mm->master);
 
+	/* Add yang-library module */
+	yang_module_load("ietf-yang-library", NULL);
+
 	/* Initialize the MGMTD Frontend Adapter Module */
 	mgmt_fe_adapter_init(mm->master);
 

mgmtd/mgmt_fe_adapter.c

@@ -1337,6 +1337,31 @@ static void fe_adapter_handle_get_data(struct mgmt_fe_session_ctx *session,
 		goto done;
 	}
 
+	/* Check for yang-library shortcut */
+	if (nb_oper_is_yang_lib_query(msg->xpath)) {
+		struct lyd_node *ylib = NULL;
+		LY_ERR err;
+
+		err = ly_ctx_get_yanglib_data(ly_native_ctx, &ylib, "%u",
+					      ly_ctx_get_change_count(
+						      ly_native_ctx));
+		if (err) {
+			fe_adapter_send_error(session, req_id, false, err,
+					      "Error getting yang-library data, session-id: %" PRIu64
+					      " error: %s",
+					      session->session_id,
+					      ly_last_errmsg());
+		} else {
+			yang_lyd_trim_xpath(&ylib, msg->xpath);
+			(void)fe_adapter_send_tree_data(session, req_id, false,
+							msg->result_type,
+							wd_options, ylib, 0);
+		}
+		if (ylib)
+			lyd_free_all(ylib);
+		goto done;
+	}
+
 	switch (msg->datastore) {
 	case MGMT_MSG_DATASTORE_CANDIDATE:
 		ds_id = MGMTD_DS_CANDIDATE;

tests/topotests/mgmt_oper/r1/frr-yanglib.conf

@@ -0,0 +1,10 @@
+log timestamp precision 6
+log file frr.log
+
+no debug memstats-at-exit
+
+debug mgmt backend datastore frontend transaction
+
+interface r1-eth0
+  ip address 1.1.1.1/24
+exit

tests/topotests/mgmt_oper/test_yanglib.py

@@ -0,0 +1,45 @@
+#!/usr/bin/env python
+# SPDX-License-Identifier: ISC
+# -*- coding: utf-8 eval: (blacken-mode 1) -*-
+#
+# September 17 2024, Christian Hopps <[email protected]>
+#
+# Copyright (c) 2024, LabN Consulting, L.L.C.
+#
+
+import json
+import pytest
+from lib.topogen import Topogen
+
+pytestmark = [pytest.mark.staticd, pytest.mark.mgmtd]
+
+
+@pytest.fixture(scope="module")
+def tgen(request):
+    "Setup/Teardown the environment and provide tgen argument to tests"
+
+    topodef = {"s1": ("r1",)}
+
+    tgen = Topogen(topodef, request.module.__name__)
+    tgen.start_topology()
+
+    router_list = tgen.routers()
+    for rname, router in router_list.items():
+        router.load_frr_config("frr-yanglib.conf")
+
+    tgen.start_router()
+    yield tgen
+    tgen.stop_topology()
+
+
+def test_yang_lib(tgen):
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    r1 = tgen.gears["r1"].net
+    output = r1.cmd_nostatus(
+        "vtysh -c 'show mgmt get-data /ietf-yang-library:yang-library'"
+    )
+    ret = json.loads(output)
+    loaded_modules = ret['ietf-yang-library:yang-library']['module-set'][0]['module']
+    assert len(loaded_modules) > 10, "Modules missing from yang-library"