Introduce a new registration mechanism to sweetcomb.

Sweetcomb plugins register for various [initialization] events
by placing structures and __attribute__((constructor)) functions
into the library. When sysrepo plugin is initializing, the framework
walks constructor-generated singly-linked structure lists, calls the
indicated functions.

Change-Id: I0cb078391f2662e4f6dd08c1a383173f203adf2a
Signed-off-by: jackiechen1985 <xiaobo.chen@tieto.com>

11 files changed, 401 insertions, 364 deletions

diff --git a/src/plugins/CMakeLists.txt b/src/plugins/CMakeLists.txt
index a07ae60..ce09682 100644
--- a/src/plugins/CMakeLists.txt
+++ b/src/plugins/CMakeLists.txt
@@ -53,10 +53,13 @@ set(CMAKE_C_FLAGS_DEBUG "-Wall -Wextra -std=gnu99 -g -O0 ${RIGOROUS_C_FLAGS}")
 #NDEBUG to skip assert checks
 set(CMAKE_C_FLAGS_RELEASE "-Wall -Wextra -std=gnu99 -DNDEBUG -O2 ${RIGOROUS_C_FLAGS}")
 
+# add plugin include directories
+include_directories(${CMAKE_CURRENT_SOURCE_DIR})
+
 # plugins sources
 set(PLUGINS_SOURCES
+    sc_init.c
     sc_plugins.c
-    sc_model.c
     ietf/ietf_interface.c
     ietf/ietf_nat.c
     openconfig/openconfig_interfaces.c
diff --git a/src/plugins/ietf/ietf_interface.c b/src/plugins/ietf/ietf_interface.c
index 0f8c37e..4d13d13 100644
--- a/src/plugins/ietf/ietf_interface.c
+++ b/src/plugins/ietf/ietf_interface.c
@@ -16,8 +16,7 @@
 #include <stdio.h>
 #include <sys/socket.h>
 
-#include "../sc_model.h"
-#include "../sys_util.h"
+#include <sc_plugins.h>
 
 #include <scvpp/interface.h>
 #include <scvpp/ip.h>
@@ -339,51 +338,55 @@ nothing_todo:
     return rc;
 }
 
-const xpath_t ietf_interfaces_xpaths[IETF_INTERFACES_SIZE] = {
-    {
-        .xpath = "/ietf-interfaces:interfaces/interface",
-        .method = XPATH,
-        .datastore = SR_DS_RUNNING,
-        .cb.scb = ietf_interface_change_cb,
-        .private_ctx = NULL,
-        .priority = 0,
-        .opts = SR_SUBSCR_CTX_REUSE | SR_SUBSCR_EV_ENABLED
-    },
-    {
-        .xpath = "/ietf-interfaces:interfaces/interface/enabled",
-        .method = XPATH,
-        .datastore = SR_DS_RUNNING,
-        .cb.scb = ietf_interface_enable_disable_cb,
-        .private_ctx = NULL,
-        .priority = 100,
-        .opts = SR_SUBSCR_CTX_REUSE | SR_SUBSCR_EV_ENABLED
-    },
-    {
-        .xpath = "/ietf-interfaces:interfaces/interface/ietf-ip:ipv4/address",
-        .method = XPATH,
-        .datastore = SR_DS_RUNNING,
-        .cb.scb = ietf_interface_ipv46_address_change_cb,
-        .private_ctx = NULL,
-        .priority = 99,
-        .opts = SR_SUBSCR_CTX_REUSE | SR_SUBSCR_EV_ENABLED
-    },
-    {
-        .xpath = "/ietf-interfaces:interfaces/interface/ietf-ip:ipv6/address",
-        .method = XPATH,
-        .datastore = SR_DS_RUNNING,
-        .cb.scb = ietf_interface_ipv46_address_change_cb,
-        .private_ctx = NULL,
-        .priority = 98,
-        .opts = SR_SUBSCR_CTX_REUSE | SR_SUBSCR_EV_ENABLED
-    },
-    {
-        .xpath = "/ietf-interfaces:interfaces-state",
-        .method = GETITEM,
-        .datastore = SR_DS_RUNNING,
-        .cb.gcb = ietf_interface_state_cb,
-        .private_ctx = NULL,
-        .priority = 98,
-        //.opts = SR_SUBSCR_DEFAULT,
-        .opts = SR_SUBSCR_CTX_REUSE
+
+int
+ietf_interface_init(sc_plugin_main_t *pm)
+{
+    int rc = SR_ERR_OK;
+    SRP_LOG_DBG_MSG("Initializing ietf-interface plugin.");
+
+    rc = sr_subtree_change_subscribe(pm->session, "/ietf-interfaces:interfaces/interface",
+            ietf_interface_change_cb, NULL, 0, SR_SUBSCR_CTX_REUSE | SR_SUBSCR_EV_ENABLED, &pm->subscription);
+    if (SR_ERR_OK != rc) {
+        goto error;
+    }
+
+    rc = sr_subtree_change_subscribe(pm->session, "/ietf-interfaces:interfaces/interface/enabled",
+            ietf_interface_enable_disable_cb, NULL, 100, SR_SUBSCR_CTX_REUSE | SR_SUBSCR_EV_ENABLED, &pm->subscription);
+    if (SR_ERR_OK != rc) {
+        goto error;
+    }
+
+    rc = sr_subtree_change_subscribe(pm->session, "/ietf-interfaces:interfaces/interface/ietf-ip:ipv4/address",
+            ietf_interface_ipv46_address_change_cb, NULL, 99, SR_SUBSCR_CTX_REUSE | SR_SUBSCR_EV_ENABLED, &pm->subscription);
+    if (SR_ERR_OK != rc) {
+        goto error;
+    }
+
+    rc = sr_subtree_change_subscribe(pm->session, "/ietf-interfaces:interfaces/interface/ietf-ip:ipv6/address",
+            ietf_interface_ipv46_address_change_cb, NULL, 98, SR_SUBSCR_CTX_REUSE | SR_SUBSCR_EV_ENABLED, &pm->subscription);
+    if (SR_ERR_OK != rc) {
+        goto error;
+    }
+
+    rc = sr_dp_get_items_subscribe(pm->session, "/ietf-interfaces:interfaces-state",
+            ietf_interface_state_cb, NULL, SR_SUBSCR_CTX_REUSE, &pm->subscription);
+    if (SR_ERR_OK != rc) {
+        goto error;
     }
-};
+
+    SRP_LOG_DBG_MSG("ietf-interface plugin initialized successfully.");
+    return SR_ERR_OK;
+
+error:
+    SRP_LOG_ERR("Error by initialization of ietf-interface plugin. Error : %d", rc);
+    return rc;
+}
+
+void
+ietf_interface_exit(__attribute__((unused)) sc_plugin_main_t *pm)
+{
+}
+
+SC_INIT_FUNCTION(ietf_interface_init);
+SC_EXIT_FUNCTION(ietf_interface_exit);
diff --git a/src/plugins/ietf/ietf_nat.c b/src/plugins/ietf/ietf_nat.c
index 3b82f28..287fa02 100644
--- a/src/plugins/ietf/ietf_nat.c
+++ b/src/plugins/ietf/ietf_nat.c
@@ -18,7 +18,7 @@
 #include <scvpp/interface.h>
 #include <scvpp/nat.h>
 
-#include "../sc_model.h"
+#include <sc_plugins.h>
 
 #include <assert.h>
 #include <string.h>
@@ -29,8 +29,6 @@
 #include <netinet/in.h>
 #include <arpa/inet.h>
 
-#include "../sys_util.h"
-
 /**
  * @brief Wrapper struct for VAPI address range payload.
  */
@@ -490,23 +488,36 @@ error:
     return rc;
 }
 
-const xpath_t ietf_nat_xpaths[IETF_NAT_SIZE] = {
-    {
-        .xpath = "/ietf-nat:nat/instances/instance/policy/external-ip-address-pool",
-        .method = XPATH,
-        .datastore = SR_DS_RUNNING,
-        .cb.scb = instances_instance_policy_external_ip_address_pool_cb,
-        .private_ctx = NULL,
-        .priority = 0,
-        .opts = SR_SUBSCR_CTX_REUSE
-    },
-    {
-        .xpath = "/ietf-nat:nat/instances/instance/mapping-table/mapping-entry",
-        .method = XPATH,
-        .datastore = SR_DS_RUNNING,
-        .cb.scb = instances_instance_mapping_table_mapping_entry_cb,
-        .private_ctx = NULL,
-        .priority = 0,
-        .opts = SR_SUBSCR_CTX_REUSE
-    },
-};
+int
+ietf_nat_init(sc_plugin_main_t *pm)
+{
+    int rc = SR_ERR_OK;
+    SRP_LOG_DBG_MSG("Initializing ietf-nat plugin.");
+
+    rc = sr_subtree_change_subscribe(pm->session, "/ietf-nat:nat/instances/instance/policy/external-ip-address-pool",
+            instances_instance_policy_external_ip_address_pool_cb, NULL, 0, SR_SUBSCR_CTX_REUSE, &pm->subscription);
+    if (rc != SR_ERR_OK) {
+        goto error;
+    }
+
+    rc = sr_subtree_change_subscribe(pm->session, "/ietf-nat:nat/instances/instance/mapping-table/mapping-entry",
+            instances_instance_mapping_table_mapping_entry_cb, NULL, 0, SR_SUBSCR_CTX_REUSE, &pm->subscription);
+    if (rc != SR_ERR_OK) {
+        goto error;
+    }
+
+    SRP_LOG_DBG_MSG("ietf-nat plugin initialized successfully.");
+    return SR_ERR_OK;
+
+error:
+    SRP_LOG_ERR("Error by initialization of ietf-nat plugin. Error : %d", rc);
+    return rc;
+}
+
+void
+ietf_nat_exit(__attribute__((unused)) sc_plugin_main_t *pm)
+{
+}
+
+SC_INIT_FUNCTION(ietf_nat_init);
+SC_EXIT_FUNCTION(ietf_nat_exit);
diff --git a/src/plugins/openconfig/openconfig_interfaces.c b/src/plugins/openconfig/openconfig_interfaces.c
index 7242c2b..67b9a3c 100644
--- a/src/plugins/openconfig/openconfig_interfaces.c
+++ b/src/plugins/openconfig/openconfig_interfaces.c
@@ -21,8 +21,7 @@
 #include <scvpp/interface.h>
 #include <scvpp/ip.h>
 
-#include "../sc_model.h"
-#include "../sys_util.h"
+#include <sc_plugins.h>
 
 // XPATH: /openconfig-interfaces:interfaces/interface[name='%s']/config/
 static int openconfig_interfaces_interfaces_interface_config_cb(
@@ -590,52 +589,58 @@ static int openconfig_interfaces_interfaces_interface_subinterfaces_subinterface
     return SR_ERR_OK;
 }
 
-const xpath_t oc_interfaces_xpaths[OC_INTERFACES_SIZE] = {
-    {
-        .xpath = "/openconfig-interfaces:interfaces/interface/config",
-        .method = XPATH,
-        .datastore = SR_DS_RUNNING,
-        .cb.scb = openconfig_interfaces_interfaces_interface_config_cb,
-        .private_ctx = NULL,
-        .priority = 98,
-        //.opts = SR_SUBSCR_DEFAULT
-        .opts = SR_SUBSCR_CTX_REUSE
-    },
-    {
-        .xpath = "/openconfig-interfaces:interfaces/interface/state",
-        .method = GETITEM,
-        .datastore = SR_DS_RUNNING,
-        .cb.gcb = openconfig_interfaces_interfaces_interface_state_cb,
-        .private_ctx = NULL,
-        .priority = 98,
-        .opts = SR_SUBSCR_CTX_REUSE
-    },
-    {
-        .xpath = "/openconfig-interfaces:interfaces/interface/subinterfaces/subinterface/state",
-        .method = GETITEM,
-        .datastore = SR_DS_RUNNING,
-        .cb.gcb = openconfig_interfaces_interfaces_interface_subinterfaces_subinterface_state_cb,
-        .private_ctx = NULL,
-        .priority = 99,
-        .opts = SR_SUBSCR_CTX_REUSE
-    },
-    {
-        .xpath = "/openconfig-interfaces:interfaces/interface/subinterfaces/subinterface/openconfig-if-ip:ipv4/openconfig-if-ip:addresses/openconfig-if-ip:address/openconfig-if-ip:config",
-        .method = XPATH,
-        .datastore = SR_DS_RUNNING,
-        .cb.scb = openconfig_interfaces_interfaces_interface_subinterfaces_subinterface_oc_ip_ipv4_oc_ip_addresses_oc_ip_address_oc_ip_config_cb,
-        .private_ctx = NULL,
-        .priority = 100,
-        //.opts = SR_SUBSCR_DEFAULT
-        .opts = SR_SUBSCR_CTX_REUSE
-    },
-    {
-        .xpath = "/openconfig-interfaces:interfaces/interface/subinterfaces/subinterface/openconfig-if-ip:ipv4/openconfig-if-ip:addresses/openconfig-if-ip:address/openconfig-if-ip:state",
-        .method = GETITEM,
-        .datastore = SR_DS_RUNNING,
-        .cb.gcb = openconfig_interfaces_interfaces_interface_subinterfaces_subinterface_oc_ip_ipv4_oc_ip_addresses_oc_ip_address_oc_ip_state_cb,
-        .private_ctx = NULL,
-        .priority = 100,
-        .opts = SR_SUBSCR_CTX_REUSE
+int
+openconfig_interface_init(sc_plugin_main_t *pm)
+{
+    int rc = SR_ERR_OK;
+    SRP_LOG_DBG_MSG("Initializing openconfig-interfaces plugin.");
+
+    rc = sr_subtree_change_subscribe(pm->session, "/openconfig-interfaces:interfaces/interface/config",
+            openconfig_interfaces_interfaces_interface_config_cb, NULL, 98, SR_SUBSCR_CTX_REUSE, &pm->subscription);
+    if (SR_ERR_OK != rc) {
+        goto error;
+    }
+
+    rc = sr_dp_get_items_subscribe(pm->session, "/openconfig-interfaces:interfaces/interface/state",
+            openconfig_interfaces_interfaces_interface_state_cb, NULL, SR_SUBSCR_CTX_REUSE, &pm->subscription);
+    if (SR_ERR_OK != rc) {
+        goto error;
+    }
+
+    rc = sr_dp_get_items_subscribe(pm->session, "/openconfig-interfaces:interfaces/interface/subinterfaces/subinterface/state",
+            openconfig_interfaces_interfaces_interface_subinterfaces_subinterface_state_cb, NULL, SR_SUBSCR_CTX_REUSE, &pm->subscription);
+    if (SR_ERR_OK != rc) {
+        goto error;
+    }
+
+    rc = sr_subtree_change_subscribe(pm->session,
+            "/openconfig-interfaces:interfaces/interface/subinterfaces/subinterface/openconfig-if-ip:ipv4/openconfig-if-ip:addresses/openconfig-if-ip:address/openconfig-if-ip:config",
+            openconfig_interfaces_interfaces_interface_subinterfaces_subinterface_oc_ip_ipv4_oc_ip_addresses_oc_ip_address_oc_ip_config_cb,
+            NULL, 100, SR_SUBSCR_CTX_REUSE, &pm->subscription);
+    if (SR_ERR_OK != rc) {
+        goto error;
+    }
+
+    rc = sr_dp_get_items_subscribe(pm->session,
+            "/openconfig-interfaces:interfaces/interface/subinterfaces/subinterface/openconfig-if-ip:ipv4/openconfig-if-ip:addresses/openconfig-if-ip:address/openconfig-if-ip:state",
+            openconfig_interfaces_interfaces_interface_subinterfaces_subinterface_oc_ip_ipv4_oc_ip_addresses_oc_ip_address_oc_ip_state_cb,
+            NULL, SR_SUBSCR_CTX_REUSE, &pm->subscription);
+    if (SR_ERR_OK != rc) {
+        goto error;
     }
-};
+
+    SRP_LOG_DBG_MSG("openconfig-interfaces plugin initialized successfully.");
+    return SR_ERR_OK;
+
+error:
+    SRP_LOG_ERR("Error by initialization of openconfig-interfaces plugin. Error : %d", rc);
+    return rc;
+}
+
+void
+openconfig_interface_exit(__attribute__((unused)) sc_plugin_main_t *pm)
+{
+}
+
+SC_INIT_FUNCTION(openconfig_interface_init);
+SC_EXIT_FUNCTION(openconfig_interface_exit);
diff --git a/src/plugins/openconfig/openconfig_local_routing.c b/src/plugins/openconfig/openconfig_local_routing.c
index 6a3b5bd..2d16da0 100644
--- a/src/plugins/openconfig/openconfig_local_routing.c
+++ b/src/plugins/openconfig/openconfig_local_routing.c
@@ -21,8 +21,7 @@
 #include <scvpp/interface.h>
 #include <scvpp/ip.h>
 
-#include "../sc_model.h"
-#include "../sys_util.h"
+#include <sc_plugins.h>
 
 #define HOP_INDEX_SIZE 10 //number of digit in max 32 bit integer
 
@@ -400,7 +399,7 @@ oc_next_hop_state_cb(const char *xpath, sr_val_t **values, size_t *values_cnt,
     if (strtoul(index, NULL, 0) != reply->path[0].next_hop_id) {
         SRP_LOG_ERR("next hop index is %d for prefix %s",
                      reply->path[0].next_hop_id, prefix);
-        SRP_LOG_ERR("before %s, stroul is %d", index,  strtoul(index, NULL, 0));
+        SRP_LOG_ERR("before %s, stroul is %lu", index, strtoul(index, NULL, 0));
         return SR_ERR_INVAL_ARG;
     }
 
@@ -468,7 +467,7 @@ oc_next_hop_interface_state_cb(const char *xpath, sr_val_t **values,
     if (strtoul(index, NULL, 0) != reply->path[0].next_hop_id) {
         SRP_LOG_ERR("next hop index is %d for prefix %s",
                      reply->path[0].next_hop_id, prefix);
-        SRP_LOG_ERR("before %s, stroul is %d", index,  strtoul(index, NULL, 0));
+        SRP_LOG_ERR("before %s, stroul is %lu", index, strtoul(index, NULL, 0));
         return SR_ERR_INVAL_ARG;
     }
 
@@ -489,62 +488,61 @@ oc_next_hop_interface_state_cb(const char *xpath, sr_val_t **values,
     return SR_ERR_OK;
 }
 
-const xpath_t oc_local_routing_xpaths[OC_LROUTING_SIZE] = {
-    {
-        .xpath = "/openconfig-local-routing:local-routes/static-routes/static/config",
-        .method = XPATH,
-        .datastore = SR_DS_RUNNING,
-        .cb.scb = oc_prefix_config_cb,
-        .private_ctx = NULL,
-        .priority = 0,
-        //.opts = SR_SUBSCR_DEFAULT
-        .opts = SR_SUBSCR_CTX_REUSE
-    },
-    {
-        .xpath = "/openconfig-local-routing:local-routes/static-routes/static/next-hops/next-hop/config",
-        .method = XPATH,
-        .datastore = SR_DS_RUNNING,
-        .cb.scb = oc_next_hop_config_cb,
-        .private_ctx = NULL,
-        .priority = 0,
-        //.opts = SR_SUBSCR_DEFAULT
-        .opts = SR_SUBSCR_CTX_REUSE
-    },
-    {
-        .xpath = "/openconfig-local-routing:local-routes/static-routes/static/next-hops/next-hop/interface-ref/config",
-        .method = XPATH,
-        .datastore = SR_DS_RUNNING,
-        .cb.scb = oc_next_hop_interface_config_cb,
-        .private_ctx = NULL,
-        .priority = 0,
-        //.opts = SR_SUBSCR_DEFAULT
-        .opts = SR_SUBSCR_CTX_REUSE
-    },
-    {
-        .xpath = "/openconfig-local-routing:local-routes/static-routes/static/state",
-        .method = GETITEM,
-        .datastore = SR_DS_RUNNING,
-        .cb.gcb = oc_prefix_state_cb,
-        .private_ctx = NULL,
-        .priority = 0,
-        .opts = SR_SUBSCR_CTX_REUSE
-    },
-    {
-        .xpath = "/openconfig-local-routing:local-routes/static-routes/static/next-hops/next-hop/state",
-        .method = GETITEM,
-        .datastore = SR_DS_RUNNING,
-        .cb.gcb = oc_next_hop_state_cb,
-        .private_ctx = NULL,
-        .priority = 0,
-        .opts = SR_SUBSCR_CTX_REUSE
-    },
-    {
-        .xpath = "/openconfig-local-routing:local-routes/static-routes/static/next-hops/next-hop/interface-ref/state",
-        .method = GETITEM,
-        .datastore = SR_DS_RUNNING,
-        .cb.gcb = oc_next_hop_interface_state_cb,
-        .private_ctx = NULL,
-        .priority = 0,
-        .opts = SR_SUBSCR_CTX_REUSE
-    },
-};
+int
+openconfig_local_routing_init(sc_plugin_main_t *pm)
+{
+    int rc = SR_ERR_OK;
+    SRP_LOG_DBG_MSG("Initializing openconfig-local-routing plugin.");
+
+    rc = sr_subtree_change_subscribe(pm->session, "/openconfig-local-routing:local-routes/static-routes/static/config",
+            oc_prefix_config_cb, NULL, 0, SR_SUBSCR_CTX_REUSE, &pm->subscription);
+    if (SR_ERR_OK != rc) {
+        goto error;
+    }
+
+    rc = sr_subtree_change_subscribe(pm->session, "/openconfig-local-routing:local-routes/static-routes/static/next-hops/next-hop/config",
+            oc_next_hop_config_cb, NULL, 0, SR_SUBSCR_CTX_REUSE, &pm->subscription);
+    if (SR_ERR_OK != rc) {
+        goto error;
+    }
+
+    rc = sr_subtree_change_subscribe(pm->session, "/openconfig-local-routing:local-routes/static-routes/static/next-hops/next-hop/interface-ref/config",
+            oc_next_hop_interface_config_cb, NULL, 0, SR_SUBSCR_CTX_REUSE, &pm->subscription);
+    if (SR_ERR_OK != rc) {
+        goto error;
+    }
+
+    rc = sr_dp_get_items_subscribe(pm->session, "/openconfig-local-routing:local-routes/static-routes/static/state",
+            oc_prefix_state_cb, NULL, SR_SUBSCR_CTX_REUSE, &pm->subscription);
+    if (SR_ERR_OK != rc) {
+        goto error;
+    }
+
+    rc = sr_dp_get_items_subscribe(pm->session, "/openconfig-local-routing:local-routes/static-routes/static/next-hops/next-hop/state",
+            oc_next_hop_state_cb, NULL, SR_SUBSCR_CTX_REUSE, &pm->subscription);
+    if (SR_ERR_OK != rc) {
+        goto error;
+    }
+
+    rc = sr_dp_get_items_subscribe(pm->session, "/openconfig-local-routing:local-routes/static-routes/static/next-hops/next-hop/interface-ref/state",
+            oc_next_hop_interface_state_cb, NULL, SR_SUBSCR_CTX_REUSE, &pm->subscription);
+    if (SR_ERR_OK != rc) {
+        goto error;
+    }
+
+    SRP_LOG_DBG_MSG("openconfig-local-routing plugin initialized successfully.");
+    return SR_ERR_OK;
+
+error:
+    SRP_LOG_ERR("Error by initialization of openconfig-local-routing plugin. Error : %d", rc);
+    return rc;
+}
+
+void
+openconfig_local_routing_exit(__attribute__((unused)) sc_plugin_main_t *pm)
+{
+}
+
+SC_INIT_FUNCTION(openconfig_local_routing_init);
+SC_EXIT_FUNCTION(openconfig_local_routing_exit);
+
diff --git a/src/plugins/sc_init.c b/src/plugins/sc_init.c
new file mode 100644
index 0000000..baae3f6
--- /dev/null
+++ b/src/plugins/sc_init.c
@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2019 Tieto and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "sc_plugins.h"
+
+int
+sc_call_all_init_function(sc_plugin_main_t *pm)
+{
+    int ret = SR_ERR_OK;
+    _sc_init_function_list_elt_t *p = pm->init_function_registrations;
+    while (p != NULL) {
+        if (!p->is_called) {
+            p->is_called = true;
+            ret = p->func(pm);
+            if (ret != SR_ERR_OK) {
+                return ret;
+            }
+        }
+        p = p->next;
+    }
+    return ret;
+}
+
+void
+sc_call_all_exit_function(sc_plugin_main_t *pm)
+{
+    _sc_exit_function_list_elt_t *p = pm->exit_function_registrations;
+    while (p != NULL) {
+        if (!p->is_called) {
+            p->is_called = true;
+            p->func(pm);
+        }
+        p = p->next;
+    }
+}
+
diff --git a/src/plugins/sc_init.h b/src/plugins/sc_init.h
new file mode 100644
index 0000000..b7ba1ef
--- /dev/null
+++ b/src/plugins/sc_init.h
@@ -0,0 +1,113 @@
+/*
+ * Copyright (c) 2019 Tieto and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __SC_INIT_H__
+#define __SC_INIT_H__
+
+#include <sysrepo.h>
+
+struct sc_plugin_main_t;
+
+/* Init/exit functions: called at start/end of sr plugin init/cleaup. */
+typedef int (sc_init_function_t) (struct sc_plugin_main_t *pm);
+typedef void (sc_exit_function_t) (struct sc_plugin_main_t *pm);
+
+/* Declaration of init/exit Linked List structures */
+#define foreach_sc_declare_function_list    \
+_(init)                                     \
+_(exit)
+
+#define _(tag)                                  \
+typedef struct _sc_##tag##_function_list_elt {  \
+    struct _sc_##tag##_function_list_elt *next; \
+    sc_##tag##_function_t *func;                \
+    bool is_called;                             \
+} _sc_##tag##_function_list_elt_t;
+foreach_sc_declare_function_list
+#undef _
+
+/* Declaration of add/rm function that need to be add/remote link list */
+#define SC_DECLARE_FUNCTION(f, tag)                                                 \
+static void __sc_add_##tag##_function_##f() __attribute__((__constructor__));       \
+static void __sc_add_##tag##_function_##f()                                         \
+{                                                                                   \
+    sc_plugin_main_t *pm = sc_get_plugin_main();                                    \
+    static _sc_##tag##_function_list_elt_t _sc_##tag##_function;                    \
+    _sc_##tag##_function.next = pm->tag##_function_registrations;                   \
+    _sc_##tag##_function.func = &f;                                                 \
+    _sc_##tag##_function.is_called = false;                                         \
+    pm->tag##_function_registrations = &_sc_##tag##_function;                       \
+}                                                                                   \
+static void __sc_rm_##tag##_function_##f() __attribute__((__destructor__));         \
+static void __sc_rm_##tag##_function_##f()                                          \
+{                                                                                   \
+    sc_plugin_main_t *pm = sc_get_plugin_main();                                    \
+    _sc_##tag##_function_list_elt_t *p;                                             \
+    if (pm->tag##_function_registrations->func == &f) {                             \
+        pm->tag##_function_registrations = pm->tag##_function_registrations->next;  \
+        return;                                                                     \
+    }                                                                               \
+    p = pm->tag##_function_registrations;                                           \
+    while (p->next != NULL) {                                                       \
+        if (p->next->func == &f) {                                                  \
+            p->next = p->next->next;                                                \
+            return;                                                                 \
+        }                                                                           \
+        p = p->next;                                                                \
+    }                                                                               \
+}
+
+/* Macros to be called from yang model implementation.
+   Register init and exit functions for YANG model implementation in Linked List. */
+#define SC_INIT_FUNCTION(f) SC_DECLARE_FUNCTION(f, init)
+#define SC_EXIT_FUNCTION(f) SC_DECLARE_FUNCTION(f, exit)
+
+/* Call given init/exit function: used for init/exit function dependencies. */
+#define sc_call_init_function(f, pm)                                    \
+({                                                                      \
+    int _ret = SR_ERR_OK;                                               \
+    _sc_init_function_list_elt_t *p = pm->init_function_registrations;  \
+    while (p != NULL) {                                                 \
+        if (p->func == f && !p->is_called) {                            \
+            p->is_called = true;                                        \
+            _ret = p->func(pm);                                         \
+            break;                                                      \
+        }                                                               \
+        p = p->next;                                                    \
+    }                                                                   \
+    _ret;                                                               \
+})
+
+#define sc_call_exit_function(f, pm)                                    \
+({                                                                      \
+    _sc_exit_function_list_elt_t *p = pm->exit_function_registrations;  \
+    while (p != NULL) {                                                 \
+        if (p->func == f && !p->is_called) {                            \
+            p->is_called = true;                                        \
+            p->func(pm);                                                \
+            break;                                                      \
+        }                                                               \
+        p = p->next;                                                    \
+    }                                                                   \
+})
+
+/* Run through all registered init/exit functions of models. */
+int
+sc_call_all_init_function(struct sc_plugin_main_t *pm);
+
+void
+sc_call_all_exit_function(struct sc_plugin_main_t *pm);
+
+#endif //__SC_INIT_H__
diff --git a/src/plugins/sc_model.c b/src/plugins/sc_model.c
deleted file mode 100644
index d9bf92b..0000000
--- a/src/plugins/sc_model.c
+++ /dev/null
@@ -1,82 +0,0 @@
-/*
- * Copyright (c) 2018 PANTHEON.tech.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at:
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "sc_model.h"
-
-#include <sysrepo/plugins.h>
-
-static int
-subscribe(sr_session_ctx_t *ds, sr_subscription_ctx_t **sub,
-          const xpath_t *xpath)
-{
-    int rc;
-
-    switch (xpath->method) {
-        case MODULE:
-            rc = sr_module_change_subscribe(ds, xpath->xpath, xpath->cb.mcb,
-                                            xpath->private_ctx, xpath->priority,
-                                            xpath->opts, sub);
-            break;
-
-        case XPATH:
-            rc = sr_subtree_change_subscribe(ds, xpath->xpath, xpath->cb.scb,
-                                             xpath->private_ctx,
-                                             xpath->priority, xpath->opts, sub);
-            break;
-
-        case GETITEM:
-            rc = sr_dp_get_items_subscribe(ds, xpath->xpath, xpath->cb.gcb,
-                                           xpath->private_ctx, xpath->opts,
-                                           sub);
-            break;
-
-        case RPC:
-            rc = sr_rpc_subscribe(ds, xpath->xpath, xpath->cb.rcb,
-                    xpath->private_ctx, xpath->opts, sub);
-            break;
-
-        default:
-            SRP_LOG_ERR("Unknown method %d", xpath->method);
-            return SR_ERR_NOT_FOUND;
-    }
-
-    if (SR_ERR_OK != rc) {
-        SRP_LOG_ERR("Error subscribing to %s", xpath->xpath);
-        return rc;
-    }
-
-    SRP_LOG_INF("Subscribed to xpath: %s", xpath->xpath);
-
-    return SR_ERR_OK;
-}
-
-int
-model_register(plugin_main_t* plugin_main, const xpath_t *xpaths, size_t size)
-{
-    int rc = 0;
-    uint32_t i = 0;
-
-    ARG_CHECK(-1, plugin_main);
-
-    for (i = 0; i < size; i++) {
-        rc = subscribe(plugin_main->session, &plugin_main->subscription,
-                       &xpaths[i]);
-        if (SR_ERR_OK != rc)
-            SRP_LOG_ERR("Subscription failed for xpath: %s", xpaths[i].xpath);
-    }
-
-    return 0;
-}
diff --git a/src/plugins/sc_model.h b/src/plugins/sc_model.h
deleted file mode 100644
index a9392f9..0000000
--- a/src/plugins/sc_model.h
+++ /dev/null
@@ -1,85 +0,0 @@
-/*
- * Copyright (c) 2018 PANTHEON.tech.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at:
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef __SC_MODEL_H__
-#define __SC_MODEL_H__
-
-/*
- * IETF or Openconfig YANG models registering/unregistering
- *
- * Every model supports a certain number of operations which require a
- * subscription to sysrepo : xpath_t
- */
-
-#include <sysrepo.h>
-#include <sysrepo/xpath.h>
-#include <sysrepo/values.h>
-#include <sysrepo/plugins.h>
-
-#include <scvpp/comm.h> //for ARG_CHECK only
-
-typedef enum {
-    MODULE,
-    XPATH,
-    GETITEM,
-    RPC,
-} method_e;
-
-#define ARRAY_SIZE(X) (sizeof(X) / sizeof(X[0]))
-
-typedef struct _xpath_t {
-    char *xpath;
-    method_e method;
-    sr_datastore_t datastore;
-    union {
-        sr_module_change_cb mcb;
-        sr_subtree_change_cb scb;
-        sr_dp_get_items_cb gcb;
-        sr_rpc_cb rcb;
-    } cb;
-    void *private_ctx;
-    uint32_t priority;
-    sr_subscr_options_t opts;
-} xpath_t;
-
-/*
- * Stateful informations. Keep sesssions informations about a user
- */
-
-typedef struct {
-    sr_session_ctx_t *session;
-    sr_subscription_ctx_t *subscription;
-} plugin_main_t;
-
-
-int
-model_register(plugin_main_t *plugin_main, const xpath_t *xpaths, size_t size);
-
-/* Declare registration */
-
-#define OC_INTERFACES_SIZE 5
-extern const xpath_t oc_interfaces_xpaths[OC_INTERFACES_SIZE];
-
-#define OC_LROUTING_SIZE 6
-extern const xpath_t oc_local_routing_xpaths[OC_LROUTING_SIZE];
-
-#define IETF_NAT_SIZE 2
-extern const xpath_t ietf_nat_xpaths[IETF_NAT_SIZE];
-
-#define IETF_INTERFACES_SIZE 5
-extern const xpath_t ietf_interfaces_xpaths[IETF_INTERFACES_SIZE];
-
-#endif /* __SC_MODEL_H__ */
diff --git a/src/plugins/sc_plugins.c b/src/plugins/sc_plugins.c
index df191bf..e0de0f6 100644
--- a/src/plugins/sc_plugins.c
+++ b/src/plugins/sc_plugins.c
@@ -13,12 +13,18 @@
  * limitations under the License.
  */
 
-#include "sc_model.h"
 #include "sc_plugins.h"
+
 #include <dirent.h>
 
+sc_plugin_main_t sc_plugin_main;
 static int vpp_pid_start;
 
+sc_plugin_main_t *sc_get_plugin_main()
+{
+    return &sc_plugin_main;
+}
+
 /* get vpp pid in system */
 int get_vpp_pid()
 {
@@ -63,26 +69,24 @@ int get_vpp_pid()
 
 int sr_plugin_init_cb(sr_session_ctx_t *session, void **private_ctx)
 {
-    plugin_main_t plugin_main;
     int rc;
 
+    sc_plugin_main.session = session;
+
     rc = sc_connect_vpp();
     if (0 != rc) {
         SRP_LOG_ERR("vpp connect error , with return %d.", rc);
         return SR_ERR_INTERNAL;
     }
 
-    plugin_main.session = session;
-    plugin_main.subscription = NULL;
-
-    /* Use the same sr_subscription_ctx for all models */
-    model_register(&plugin_main, ietf_interfaces_xpaths, IETF_INTERFACES_SIZE);
-    model_register(&plugin_main, ietf_nat_xpaths, IETF_NAT_SIZE);
-    model_register(&plugin_main, oc_interfaces_xpaths, OC_INTERFACES_SIZE);
-    model_register(&plugin_main, oc_local_routing_xpaths, OC_LROUTING_SIZE);
+    rc = sc_call_all_init_function(&sc_plugin_main);
+    if (rc != SR_ERR_OK) {
+        SRP_LOG_ERR("Call all init function error: %d", rc);
+        return rc;
+    }
 
     /* set subscription as our private context */
-    *private_ctx = plugin_main.subscription;
+    *private_ctx = sc_plugin_main.subscription;
     /* get the vpp pid sweetcomb connected, we assumed that only one vpp is run in system */
     vpp_pid_start = get_vpp_pid();
     return SR_ERR_OK;
@@ -90,6 +94,8 @@ int sr_plugin_init_cb(sr_session_ctx_t *session, void **private_ctx)
 
 void sr_plugin_cleanup_cb(sr_session_ctx_t *session, void *private_ctx)
 {
+   sc_call_all_exit_function(&sc_plugin_main);
+
     /* subscription was set as our private context */
     if (private_ctx != NULL)
         sr_unsubscribe(session, private_ctx);
diff --git a/src/plugins/sc_plugins.h b/src/plugins/sc_plugins.h
index 4a784fb..681be6b 100644
--- a/src/plugins/sc_plugins.h
+++ b/src/plugins/sc_plugins.h
@@ -20,6 +20,23 @@
 #include <sysrepo/values.h>
 #include <sysrepo/plugins.h>
 
+#include "sc_init.h"
+#include "sys_util.h"
+
+typedef struct sc_plugin_main_t {
+    /* Session context acquired with ::sr_session_start call. */
+    sr_session_ctx_t *session;
+
+    /* Subscription context that is supposed to be released by ::sr_unsubscribe */
+    sr_subscription_ctx_t *subscription;
+
+    /* List of init/exit functions to call, setup by constructors */
+    _sc_init_function_list_elt_t *init_function_registrations;
+    _sc_exit_function_list_elt_t *exit_function_registrations;
+} sc_plugin_main_t;
+
+sc_plugin_main_t *sc_get_plugin_main();
+
 //functions that sysrepo-plugin need
 int sr_plugin_init_cb(sr_session_ctx_t *session, void **private_ctx);
 void sr_plugin_cleanup_cb(sr_session_ctx_t *session, void *private_ctx);