Openconfig interfaces xpath.

Change-Id: If8af26c846ae82b7ef311e7d0b431c026ad0da25
Signed-off-by: Andrej Kozemcak <andrej.kozemcak@pantheon.tech>

5 files changed, 1047 insertions, 0 deletions

diff --git a/src/plugins/CMakeLists.txt b/src/plugins/CMakeLists.txt
index 0c39258..7482ad7 100644
--- a/src/plugins/CMakeLists.txt
+++ b/src/plugins/CMakeLists.txt
@@ -35,6 +35,8 @@ endif()
 set(PLUGINS_SOURCES
     sc_interface.c
     sc_plugins.c
+    openconfig/openconfig_interfaces.c
+    openconfig/sys_util.c
 )
 
 
diff --git a/src/plugins/openconfig/openconfig_interfaces.c b/src/plugins/openconfig/openconfig_interfaces.c
new file mode 100644
index 0000000..a985488
--- /dev/null
+++ b/src/plugins/openconfig/openconfig_interfaces.c
@@ -0,0 +1,876 @@
+/*
+ * 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 "openconfig_interfaces.h"
+#include "sys_util.h"
+#include "sc_vpp_operation.h"
+
+#include "../bapi/bapi.h"
+#include "../bapi/bapi_interface.h"
+#include "../bapi/bapi_ip.h"
+
+#include <assert.h>
+#include <string.h>
+#include <sysrepo/xpath.h>
+#include <sysrepo/values.h>
+
+#define XPATH_SIZE 2000
+
+static int oi_enable_interface(const char *interface_name,
+                               const bool enable)
+{
+    ARG_CHECK(-1, interface_name);
+
+    int rc = 0;
+    sw_interface_details_query_t query = {0};
+    sw_interface_details_query_set_name(&query, interface_name);
+
+    if (false == get_interface_id(&query)) {
+        return -1;
+    }
+
+    rc = bin_api_sw_interface_set_flags(query.sw_interface_details.sw_if_index,
+                                        enable);
+    if (VAPI_OK != rc) {
+        SRP_LOG_ERR_MSG("Call bin_api_sw_interface_set_flags.");
+        rc = -1;
+    }
+
+    return rc;
+}
+
+// XPATH: /openconfig-interfaces:interfaces/interface[name='%s']/config/
+int openconfig_interfaces_interfaces_interface_config_cb(
+    sr_session_ctx_t *ds, const char *xpath, sr_notif_event_t event,
+    __attribute__((unused)) void *private_ctx)
+{
+    sr_change_iter_t *it = NULL;
+    sr_change_oper_t oper;
+    sr_val_t *old_val = NULL;
+    sr_val_t *new_val = NULL;
+    char *tmp = NULL;
+    char interface_name[XPATH_SIZE] = {0};
+    int rc = 0;
+
+    ARG_CHECK2(SR_ERR_INVAL_ARG, ds, xpath);
+
+    // if we receive event SR_EV_APPLY - config has changed
+
+    log_recv_event(event, "subtree_change_cb received");
+    SRP_LOG_DBG("[SRP_LOG_DBG] xpath: %s", xpath);
+
+    // apply configuration
+    //
+    //
+    // in this type i guess we can call sr_get_item()
+    // because we are subscribed to leaf we shouldn't
+    // get more than one change in one callback
+    // each chage represent change in a hierarchy of
+    // xml document
+    //
+    if (event != SR_EV_APPLY) {
+        return SR_ERR_OK;
+    }
+
+    // first we get event VERIFY
+    // then  we get event APPLY
+    //  - we can   return error from VERIFY event
+    //  - we can't return error from APPLY event
+
+    if (sr_get_changes_iter(ds, (char *)xpath, &it) != SR_ERR_OK) {
+        // in example he calls even on fale
+        sr_free_change_iter(it);
+        return SR_ERR_OK;
+    }
+
+    while (sr_get_change_next(ds, it, &oper,
+        &old_val, &new_val) == SR_ERR_OK) {
+
+        log_recv_oper(oper, "subtree_change_cb received");
+
+        SRP_LOG_DBG("xpath: %s", new_val->xpath);
+
+        sr_xpath_ctx_t state = {0};
+
+        tmp = xpath_find_first_key(new_val->xpath, "name", &state);
+        if (NULL == tmp) {
+            SRP_LOG_DBG_MSG("interface_name NOT found.");
+            continue;
+        }
+
+        strncpy(interface_name, tmp, XPATH_SIZE);
+        sr_xpath_recover(&state);
+
+        switch (oper) {
+            case SR_OP_CREATED:
+                if (sr_xpath_node_name_eq(new_val->xpath, "name")) {
+                    //TODO: LEAF: name, type: string
+                } else if(sr_xpath_node_name_eq(new_val->xpath, "type")) {
+                    //TODO: LEAF: type, type: identityref
+                } else if(sr_xpath_node_name_eq(new_val->xpath, "mtu")) {
+                    //TODO: LEAF: mtu, type: uint16
+                } else if(sr_xpath_node_name_eq(new_val->xpath,
+                    "loopback-mode")) {
+                    //TODO: LEAF: loopback-mode, type: boolean
+                } else if(sr_xpath_node_name_eq(new_val->xpath,
+                                                            "description")) {
+                    //TODO: LEAF: description, type: string
+                } else if(sr_xpath_node_name_eq(new_val->xpath, "enabled")) {
+                    rc = oi_enable_interface(interface_name,
+                                             new_val->data.bool_val);
+                } else if(sr_xpath_node_name_eq(new_val->xpath,
+                                                 "oc-vlan:tpid")) {
+                    //TODO: LEAF: oc-vlan:tpid, type: identityref
+                }
+                break;
+
+            case SR_OP_MODIFIED:
+                if (sr_xpath_node_name_eq(new_val->xpath, "name")) {
+                    //TODO: LEAF: name, type: string
+                } else if(sr_xpath_node_name_eq(new_val->xpath, "type")) {
+                    //TODO: LEAF: type, type: identityref
+                } else if(sr_xpath_node_name_eq(new_val->xpath, "mtu")) {
+                    //TODO: LEAF: mtu, type: uint16
+                } else if(sr_xpath_node_name_eq(new_val->xpath,
+                    "loopback-mode")) {
+                    //TODO: LEAF: loopback-mode, type: boolean
+                } else if(sr_xpath_node_name_eq(new_val->xpath,
+                                                    "description")) {
+                    //TODO: LEAF: description, type: string
+                } else if(sr_xpath_node_name_eq(new_val->xpath, "enabled")) {
+                    rc = oi_enable_interface(interface_name,
+                                             new_val->data.bool_val);
+                } else if(sr_xpath_node_name_eq(new_val->xpath,
+                                                 "oc-vlan:tpid")) {
+                    //TODO: LEAF: oc-vlan:tpid, type: identityref
+                }
+                break;
+
+            case SR_OP_MOVED:
+                break;
+
+            case SR_OP_DELETED:
+                if (sr_xpath_node_name_eq(old_val->xpath, "name")) {
+                    //TODO: LEAF: name, type: string
+                } else if(sr_xpath_node_name_eq(old_val->xpath, "type")) {
+                    //TODO: LEAF: type, type: identityref
+                } else if(sr_xpath_node_name_eq(old_val->xpath, "mtu")) {
+                    //TODO: LEAF: mtu, type: uint16
+                } else if(sr_xpath_node_name_eq(old_val->xpath,
+                    "loopback-mode")) {
+                    //TODO: LEAF: loopback-mode, type: boolean
+                } else if(sr_xpath_node_name_eq(old_val->xpath,
+                                                    "description")) {
+                    //TODO: LEAF: description, type: string
+                } else if(sr_xpath_node_name_eq(old_val->xpath, "enabled")) {
+                    rc = oi_enable_interface(interface_name, false);
+                } else if(sr_xpath_node_name_eq(old_val->xpath,
+                                                 "oc-vlan:tpid")) {
+                    //TODO: LEAF: oc-vlan:tpid, type: identityref
+                }
+                break;
+        }
+
+        if (0 != rc) {
+            sr_xpath_recover(&state);
+
+            sr_free_val(old_val);
+            sr_free_val(new_val);
+
+            sr_free_change_iter(it);
+
+            return SR_ERR_OPERATION_FAILED;
+        }
+
+        sr_xpath_recover(&state);
+
+        sr_free_val(old_val);
+        sr_free_val(new_val);
+    }
+
+    sr_free_change_iter(it);
+    return SR_ERR_OK;
+}
+
+int openconfig_interface_mod_cb(
+    __attribute__((unused)) sr_session_ctx_t *session,
+    __attribute__((unused)) const char *module_name,
+    __attribute__((unused)) sr_notif_event_t event,
+    __attribute__((unused)) void *private_ctx)
+{
+    SRP_LOG_DBG("Inerafce module subscribe: %s", module_name);
+
+    return SR_ERR_OK;
+}
+
+typedef struct
+{
+    bool is_subif;
+    u32 subinterface_index;
+    sw_interface_details_query_t sw_interface_details_query;
+    sysr_values_ctx_t sysr_values_ctx;
+} sys_sw_interface_dump_ctx;
+
+#define NOT_AVAL "NA"
+
+// XPATH: /openconfig-interfaces:interfaces/interface/state
+
+static int sw_interface_dump_cb_inner(
+    vapi_payload_sw_interface_details * reply,
+    sys_sw_interface_dump_ctx * dctx)
+{
+    sr_val_t *vals = NULL;
+    int rc = 0;
+    int vc = 0;
+
+    ARG_CHECK2(SR_ERR_INVAL_ARG, reply, dctx);
+
+    vc = 10;
+
+    /* convenient functions such as this can be found in sysrepo/values.h */
+    rc = sr_new_values(vc, &vals);
+    if (SR_ERR_OK != rc) {
+        return rc;
+    }
+
+    const char* interface_name = (const char*)dctx->sw_interface_details_query.sw_interface_details.interface_name;
+
+    sr_val_build_xpath(&vals[0], "%s/name", dctx->sysr_values_ctx.xpath_root);
+    sr_val_set_str_data(&vals[0], SR_STRING_T, interface_name);
+
+    sr_val_build_xpath(&vals[1], "%s/type", dctx->sysr_values_ctx.xpath_root);
+    sr_val_set_str_data(&vals[1], SR_IDENTITYREF_T, "ianaift:ethernetCsmacd");
+
+    sr_val_build_xpath(&vals[2], "%s/mtu", dctx->sysr_values_ctx.xpath_root);
+    vals[2].type = SR_UINT16_T;
+    vals[2].data.uint16_val = reply->link_mtu;
+
+    sr_val_build_xpath(&vals[3], "%s/loopback-mode",
+                       dctx->sysr_values_ctx.xpath_root);
+    vals[3].type = SR_BOOL_T;
+    vals[3].data.bool_val = (0 == strncmp(interface_name, "loop", 4)) ? 1 : 0;
+
+    sr_val_build_xpath(&vals[4], "%s/description",
+                       dctx->sysr_values_ctx.xpath_root);
+    sr_val_set_str_data(&vals[4], SR_STRING_T, NOT_AVAL);
+
+    sr_val_build_xpath(&vals[5], "%s/enabled",
+                       dctx->sysr_values_ctx.xpath_root);
+    vals[5].type = SR_BOOL_T;
+    vals[5].data.bool_val = reply->admin_up_down;
+
+    sr_val_build_xpath(&vals[6], "%s/ifindex",
+                       dctx->sysr_values_ctx.xpath_root);
+    vals[6].type = SR_UINT32_T;
+    vals[6].data.uint32_val = reply->sw_if_index;
+
+    sr_val_build_xpath(&vals[7], "%s/admin-status",
+                       dctx->sysr_values_ctx.xpath_root);
+    sr_val_set_str_data(&vals[7], SR_ENUM_T,
+                        reply->admin_up_down ? "UP" : "DOWN");
+
+    sr_val_build_xpath(&vals[8], "%s/oper-status",
+                       dctx->sysr_values_ctx.xpath_root);
+    sr_val_set_str_data(&vals[8], SR_ENUM_T,
+                        reply->link_up_down ? "UP" : "DOWN");
+
+    //TODO: Openconfig required this value
+    // sr_val_build_xpath(&vals[9], "%s/last-change", dctx->sysr_values_ctx.xpath_root);
+    // sr_val_set_str_data(&vals[9], YANG INPUT TYPE: oc-types:timeticks64);
+
+    sr_val_build_xpath(&vals[9], "%s/logical",
+                       dctx->sysr_values_ctx.xpath_root);
+    vals[9].type = SR_BOOL_T;
+    vals[9].data.bool_val = true;         //for now, we assume all are logical
+
+    dctx->sysr_values_ctx.values = vals;
+    dctx->sysr_values_ctx.values_cnt = vc;
+
+    return SR_ERR_OK;
+}
+
+
+// XPATH: /openconfig-interfaces:interfaces/interface/subinterfaces/subinterface/state
+static int sw_subinterface_dump_cb_inner(
+    vapi_payload_sw_interface_details *reply,
+    sys_sw_interface_dump_ctx *dctx)
+{
+    sr_val_t *vals = NULL;
+    int rc = 0;
+    int vc = 0, val_idx = 0;
+
+    ARG_CHECK2(SR_ERR_INVAL_ARG, reply, dctx);
+
+    vc = 6;
+    /* convenient functions such as this can be found in sysrepo/values.h */
+    rc = sr_new_values(vc, &vals);
+    if (SR_ERR_OK != rc) {
+        return rc;
+    }
+
+    sr_val_build_xpath(&vals[val_idx], "%s/index",
+                       dctx->sysr_values_ctx.xpath_root);
+    vals[val_idx].type = SR_UINT32_T;
+    vals[val_idx++].data.uint32_val = dctx->subinterface_index;
+
+    sr_val_build_xpath(&vals[val_idx], "%s/description",
+                       dctx->sysr_values_ctx.xpath_root);
+    sr_val_set_str_data(&vals[val_idx++], SR_STRING_T, NOT_AVAL);
+
+    sr_val_build_xpath(&vals[val_idx], "%s/enabled",
+                       dctx->sysr_values_ctx.xpath_root);
+    vals[val_idx].type = SR_BOOL_T;
+    vals[val_idx++].data.bool_val = reply->admin_up_down;
+
+    //TODO: Openconfig required this value
+    // sr_val_build_xpath(&vals[val_idx], "%s/name", dctx->sysr_values_ctx.xpath_root);
+    // sr_val_set_str_data(&vals[val_idx++], SR_STRING_T, YANG INPUT TYPE: string);
+
+    // sr_val_build_xpath(&vals[val_idx], "%s/ifindex", interface_name, subinterface_index);
+    // vals[val_idx].type = SR_UINT32_T;
+    // vals[val_idx++].data.uint32_val = YANG INPUT TYPE: uint32;
+
+    sr_val_build_xpath(&vals[val_idx], "%s/admin-status",
+                       dctx->sysr_values_ctx.xpath_root);
+    sr_val_set_str_data(&vals[val_idx++], SR_ENUM_T,
+                        reply->admin_up_down ? "UP" : "DOWN");
+
+    sr_val_build_xpath(&vals[val_idx], "%s/oper-status",
+                       dctx->sysr_values_ctx.xpath_root);
+    sr_val_set_str_data(&vals[val_idx++], SR_ENUM_T,
+                        reply->admin_up_down ? "UP" : "DOWN");
+
+    //TODO: Openconfig required this value
+    // sr_val_build_xpath(&vals[val_idx], "/openconfig-interfaces:interfaces/interface[name='%s']/subinterfaces/subinterface[index='%s']/state/last-change", interface_name, subinterface_index);
+    // sr_val_set_str_data(&vals[val_idx++], YANG INPUT TYPE: oc-types:timeticks64);
+
+    sr_val_build_xpath(&vals[val_idx], "%s/logical",
+                       dctx->sysr_values_ctx.xpath_root);
+    vals[val_idx].type = SR_BOOL_T;
+    vals[val_idx++].data.bool_val = true;         //for now, we assume all are logical
+
+    dctx->sysr_values_ctx.values = vals;
+    dctx->sysr_values_ctx.values_cnt = vc;
+
+    return SR_ERR_OK;
+}
+
+static
+bool is_subinterface(const char* subif_name, const char* base_name,
+                     const u32 subif_index)
+{
+    assert(subif_name && base_name);
+
+    const char* dot = strchr(subif_name, '.');
+
+    if (NULL == dot && 0 == subif_index)
+        return true;                    //subif_index == 0 can pass as a "real" interface
+
+    if (dot > subif_name && 0 == strncmp(subif_name, base_name,
+        dot - subif_name))
+    {
+        char * eptr = NULL;
+        u32 si = strtoul(dot + 1, &eptr, 10);
+
+        if ('\0' == *eptr && subif_index == si)
+            return true;
+    }
+
+    return false;
+}
+
+static vapi_error_e
+sw_interface_dump_vapi_cb(struct vapi_ctx_s *ctx, void *callback_ctx,
+                     vapi_error_e rv, bool is_last,
+                     vapi_payload_sw_interface_details * reply)
+{
+    ARG_CHECK(VAPI_EINVAL, callback_ctx);
+
+    if (is_last)
+    {
+        assert (NULL == reply);
+    }
+    else
+    {
+        assert (NULL != reply);
+        sys_sw_interface_dump_ctx *dctx = callback_ctx;
+
+        const char* const dctx_interface_name = (const char *)dctx->sw_interface_details_query.sw_interface_details.interface_name;
+
+        SRP_LOG_DBG("interface_name: '%s', if_name: '%s'", reply->interface_name, dctx_interface_name);
+
+        if (dctx->is_subif)
+        {
+            if (is_subinterface((const char*)reply->interface_name,
+                dctx_interface_name, dctx->subinterface_index))
+                sw_subinterface_dump_cb_inner(reply, dctx);
+        }
+        else
+        {
+            if (0 == strcmp(dctx_interface_name, (char *)reply->interface_name))
+            {
+                dctx->sw_interface_details_query.sw_interface_details = *reply;
+                dctx->sw_interface_details_query.interface_found = true;
+
+                sw_interface_dump_cb_inner(reply, dctx);
+            }
+        }
+    }
+
+    return VAPI_OK;
+}
+
+static vapi_error_e sysr_sw_interface_dump(sys_sw_interface_dump_ctx * dctx)
+{
+    ARG_CHECK(VAPI_EINVAL, dctx);
+
+    vapi_msg_sw_interface_dump *dump = vapi_alloc_sw_interface_dump(g_vapi_ctx);
+    vapi_error_e rv;
+
+    dump->payload.name_filter_valid = true;
+    strcpy((char*)dump->payload.name_filter, (const char *)dctx->sw_interface_details_query.sw_interface_details.interface_name);
+
+    VAPI_CALL(vapi_sw_interface_dump(g_vapi_ctx, dump, sw_interface_dump_vapi_cb,
+                                     dctx));
+
+    if (VAPI_OK != rv) {
+        SRP_LOG_DBG("vapi_sw_interface_dump error=%d", rv);
+    }
+
+    return rv;
+}
+
+int openconfig_interfaces_interfaces_interface_state_cb(
+    const char *xpath, sr_val_t **values,
+    size_t *values_cnt, uint64_t request_id,
+    __attribute__((unused)) void *private_ctx)
+{
+    sr_xpath_ctx_t state = {0};
+    char *tmp = NULL;
+    char interface_name[XPATH_SIZE] = {0};
+
+    ARG_CHECK3(SR_ERR_INVAL_ARG, xpath, values, values_cnt);
+
+    tmp = xpath_find_first_key(xpath, "name", &state);
+    if (NULL == tmp) {
+        SRP_LOG_DBG_MSG("interface_name not found.");
+        return SR_ERR_INVAL_ARG;
+    }
+
+    strncpy(interface_name, tmp, XPATH_SIZE);
+    sr_xpath_recover(&state);
+
+    sys_sw_interface_dump_ctx dctx = {
+        .is_subif = false
+    };
+    sw_interface_details_query_set_name(&dctx.sw_interface_details_query,
+                                        interface_name);
+
+    snprintf(dctx.sysr_values_ctx.xpath_root, XPATH_SIZE,
+             "/openconfig-interfaces:interfaces/interface[name='%s']/state",
+             interface_name);
+
+    sysr_sw_interface_dump(&dctx);
+
+    if (!dctx.sw_interface_details_query.interface_found) {
+        SRP_LOG_DBG_MSG("interface not found");
+        return SR_ERR_NOT_FOUND;
+    }
+
+    sr_xpath_recover(&state);
+    *values = dctx.sysr_values_ctx.values;
+    *values_cnt = dctx.sysr_values_ctx.values_cnt;
+
+    return SR_ERR_OK;
+}
+
+// XPATH: /openconfig-interfaces:interfaces/interface/subinterfaces/subinterface/openconfig-if-ip:ipv4/openconfig-if-ip:addresses/openconfig-if-ip:address/openconfig-if-ip:state
+int openconfig_interfaces_interfaces_interface_subinterfaces_subinterface_oc_ip_ipv4_oc_ip_addresses_oc_ip_address_oc_ip_state_vapi_cb(
+    vapi_payload_ip_address_details *reply,
+    sysr_values_ctx_t *sysr_values_ctx)
+{
+    sr_val_t *vals = NULL;
+    int rc = 0;
+    int vc = 0;
+
+    ARG_CHECK2(SR_ERR_INVAL_ARG, reply, sysr_values_ctx);
+
+    vc = 3;
+    /* convenient functions such as this can be found in sysrepo/values.h */
+    rc = sr_new_values(vc, &vals);
+    if (SR_ERR_OK != rc) {
+        return rc;
+    }
+
+    char * address_ip = bapi_ntoa(reply->ip);
+
+    sr_val_build_xpath(&vals[0], "%s/openconfig-if-ip:ip",
+                       sysr_values_ctx->xpath_root);
+    sr_val_set_str_data(&vals[0], SR_STRING_T, address_ip);
+
+    sr_val_build_xpath(&vals[1], "%s/openconfig-if-ip:prefix-length",
+                       sysr_values_ctx->xpath_root);
+    vals[1].type = SR_UINT8_T;
+    vals[1].data.uint8_val = reply->prefix_length;
+
+    sr_val_build_xpath(&vals[2], "%s/openconfig-if-ip:origin",
+                       sysr_values_ctx->xpath_root);
+    sr_val_set_str_data(&vals[2], SR_ENUM_T, "STATIC");
+
+    sysr_values_ctx->values = vals;
+    sysr_values_ctx->values_cnt = vc;
+
+    return SR_ERR_OK;
+}
+
+vapi_error_e
+ip_address_dump_cb (struct vapi_ctx_s *ctx, void *callback_ctx,
+                    vapi_error_e rv, bool is_last,
+                    vapi_payload_ip_address_details * reply)
+{
+    ARG_CHECK2(VAPI_EINVAL, ctx, callback_ctx);
+
+    sysr_values_ctx_t *dctx = callback_ctx;
+
+    if (is_last)
+    {
+        assert (NULL == reply);
+    }
+    else
+    {
+        assert (NULL != reply);
+
+        printf ("ip address dump entry:"
+                    "\tsw_if_index[%u]"
+                    "\tip[%s/%u]\n"
+                    , reply->sw_if_index, bapi_ntoa(reply->ip),
+                reply->prefix_length);
+
+        openconfig_interfaces_interfaces_interface_subinterfaces_subinterface_oc_ip_ipv4_oc_ip_addresses_oc_ip_address_oc_ip_state_vapi_cb(reply, dctx);
+    }
+
+    return VAPI_OK;
+}
+
+//TODO: for some arcane reason, this doesn't work
+int openconfig_interfaces_interfaces_interface_subinterfaces_subinterface_oc_ip_ipv4_oc_ip_addresses_oc_ip_address_oc_ip_state_cb(
+    const char *xpath, sr_val_t **values, size_t *values_cnt,
+    __attribute__((unused)) uint64_t request_id,
+    __attribute__((unused)) void *private_ctx)
+{
+    sr_xpath_ctx_t state = {0};
+    vapi_error_e rv;
+    char *tmp = NULL;
+    char interface_name[XPATH_SIZE] = {0};
+    char subinterface_index[XPATH_SIZE] = {0};
+    char address_ip[XPATH_SIZE] = {0};
+
+    ARG_CHECK3(SR_ERR_INVAL_ARG, xpath, values, values_cnt);
+
+    tmp = xpath_find_first_key(xpath, "name", &state);
+    if (NULL == tmp) {
+        SRP_LOG_ERR_MSG("interface_name not found.");
+        return SR_ERR_INVAL_ARG;
+    }
+
+    strncpy(interface_name, tmp, XPATH_SIZE);
+    sr_xpath_recover(&state);
+
+    tmp = xpath_find_first_key(xpath, "index", &state);
+    if (NULL == tmp) {
+        SRP_LOG_ERR_MSG("subinterface_index not found.");
+        return SR_ERR_INVAL_ARG;
+    }
+
+    strncpy(subinterface_index, tmp, XPATH_SIZE);
+    sr_xpath_recover(&state);
+
+    tmp = xpath_find_first_key(xpath, "ip", &state);
+    if (NULL == tmp) {
+        SRP_LOG_ERR_MSG("address_ip not found.");
+        return SR_ERR_INVAL_ARG;
+    }
+
+    strncpy(address_ip, tmp, XPATH_SIZE);
+    sr_xpath_recover(&state);
+
+    sysr_values_ctx_t dctx = {0};
+    snprintf(dctx.xpath_root, XPATH_SIZE, "/openconfig-interfaces:interfaces/interface[name='%s']/subinterfaces/subinterface[index='%s']/openconfig-if-ip:ipv4/openconfig-if-ip:addresses/openconfig-if-ip:address[ip='%s']/openconfig-if-ip:state",
+             interface_name, subinterface_index, address_ip);
+
+    sw_interface_details_query_t query = {0};
+    sw_interface_details_query_set_name(&query, interface_name);
+
+    if (!get_interface_id(&query))
+    {
+        return SR_ERR_INVAL_ARG;
+    }
+
+    vapi_msg_ip_address_dump *mp = vapi_alloc_ip_address_dump (g_vapi_ctx);
+    mp->payload.sw_if_index = query.sw_interface_details.sw_if_index;
+    mp->payload.is_ipv6 = 0;
+
+    rv = vapi_ip_address_dump(g_vapi_ctx, mp, ip_address_dump_cb, &dctx);
+    if (VAPI_OK != rv)
+    {
+        SRP_LOG_ERR_MSG("VAPI call failed");
+        return SR_ERR_INVAL_ARG;
+    }
+
+    sr_xpath_recover(&state);
+    *values = dctx.values;
+    *values_cnt = dctx.values_cnt;
+
+    return SR_ERR_OK;
+}
+
+int openconfig_interfaces_interfaces_interface_subinterfaces_subinterface_state_cb(
+    const char *xpath, sr_val_t **values, size_t *values_cnt,
+    __attribute__((unused)) uint64_t request_id,
+    __attribute__((unused)) void *private_ctx)
+{
+    sr_xpath_ctx_t state = {0};
+    char *tmp = NULL;
+    char interface_name[XPATH_SIZE] = {0};
+    char subinterface_index[XPATH_SIZE] = {0};
+
+    ARG_CHECK3(SR_ERR_INVAL_ARG, xpath, values, values_cnt);
+
+    tmp = xpath_find_first_key(xpath, "name", &state);
+    if (NULL == tmp) {
+        SRP_LOG_ERR_MSG("interface_name not found.");
+        return SR_ERR_INVAL_ARG;
+    }
+
+    strncpy(interface_name, tmp, XPATH_SIZE);
+    sr_xpath_recover(&state);
+
+    tmp = xpath_find_first_key(xpath, "index", &state);
+    if (NULL == tmp) {
+        SRP_LOG_ERR_MSG("subinterface_index not found.");
+        return SR_ERR_INVAL_ARG;
+    }
+
+    strncpy(subinterface_index, tmp, XPATH_SIZE);
+    sr_xpath_recover(&state);
+
+    sys_sw_interface_dump_ctx dctx =
+    {
+        .is_subif = true,
+        .subinterface_index = atoi(subinterface_index)
+    };
+    sw_interface_details_query_set_name(&dctx.sw_interface_details_query,
+                                        interface_name);
+
+    snprintf(dctx.sysr_values_ctx.xpath_root, XPATH_SIZE, "/openconfig-interfaces:interfaces/interface[name='%s']/subinterfaces/subinterface[index='%s']/state",
+             interface_name, subinterface_index);
+
+    sysr_sw_interface_dump(&dctx);
+
+    if (!dctx.sw_interface_details_query.interface_found) {
+        SRP_LOG_DBG_MSG("interface not found");
+        return SR_ERR_NOT_FOUND;
+    }
+
+    sr_xpath_recover(&state);
+    *values = dctx.sysr_values_ctx.values;
+    *values_cnt = dctx.sysr_values_ctx.values_cnt;
+
+    return SR_ERR_OK;
+}
+
+VAPI_RETVAL_CB(sw_interface_add_del_address);
+
+static int oi_int_ipv4_conf(const char *interface_name,
+                            const char *address_ip, u8 prefix_length,
+                            bool is_add)
+{
+    ARG_CHECK2(-1, interface_name, address_ip);
+
+    sw_interface_details_query_t query = {0};
+    sw_interface_details_query_set_name(&query, interface_name);
+    if (!get_interface_id(&query)) {
+        return 0;
+    }
+
+    if (VAPI_OK != bin_api_sw_interface_add_del_address(query.sw_interface_details.sw_if_index,
+        is_add, address_ip, prefix_length))
+    {
+        SRP_LOG_ERR_MSG("Call vapi_sw_interface_add_del_address.");
+        return -1;
+    }
+
+    return 0;
+}
+
+// XPATH: /openconfig-interfaces:interfaces/interface[name='%s']/subinterfaces/subinterface[index='%s']/oc-ip:ipv4/oc-ip:addresses/oc-ip:address[ip='%s']/oc-ip:config/
+int openconfig_interfaces_interfaces_interface_subinterfaces_subinterface_oc_ip_ipv4_oc_ip_addresses_oc_ip_address_oc_ip_config_cb(
+    sr_session_ctx_t *ds, const char *xpath, sr_notif_event_t event,
+    __attribute__((unused)) void *private_ctx)
+{
+    sr_change_iter_t *it = NULL;
+    sr_change_oper_t oper;
+    sr_val_t *old_val = NULL;
+    sr_val_t *new_val = NULL;
+    char *tmp = NULL;
+    char interface_name[XPATH_SIZE] = {0};
+    char subinterface_index[XPATH_SIZE] = {0};
+    char address_ip[XPATH_SIZE] = {0};
+    char old_address_ip[XPATH_SIZE] = {0};
+    u8 prefix_len = 0;
+    u8 old_prefix_len = 0;
+    int rc = 0;
+    bool ip_set = false, prefix_len_set = false;
+    bool old_ip_set = false, old_prefix_len_set = false;
+
+    ARG_CHECK2(SR_ERR_INVAL_ARG, ds, xpath);
+
+    // if we receive event SR_EV_APPLY - config has changed
+
+    log_recv_event(event, "subtree_change_cb received");
+    SRP_LOG_DBG("[SRP_LOG_DBG] xpath: %s", xpath);
+
+    if (event != SR_EV_APPLY) {
+        return SR_ERR_OK;
+    }
+
+    if (sr_get_changes_iter(ds, (char *)xpath, &it) != SR_ERR_OK) {
+        // in example he calls even on fale
+        sr_free_change_iter(it);
+        return SR_ERR_OK;
+    }
+
+    while (sr_get_change_next(ds, it, &oper,
+        &old_val, &new_val) == SR_ERR_OK) {
+
+        log_recv_oper(oper, "subtree_change_cb received");
+
+        SRP_LOG_DBG("xpath: %s", new_val->xpath);
+
+        sr_xpath_ctx_t state = {0};
+
+        tmp = xpath_find_first_key(new_val->xpath, "name", &state);
+        if (NULL == tmp) {
+            SRP_LOG_DBG_MSG("interface_name NOT found.");
+            continue;
+        }
+
+        strncpy(interface_name, tmp, XPATH_SIZE);
+        sr_xpath_recover(&state);
+
+        tmp = xpath_find_first_key(new_val->xpath, "index", &state);
+        if (NULL == tmp) {
+            SRP_LOG_DBG_MSG("subinterface_index NOT found.");
+            continue;
+        }
+
+        strncpy(subinterface_index, tmp, XPATH_SIZE);
+        sr_xpath_recover(&state);
+
+        switch (oper) {
+            case SR_OP_CREATED:
+                if (sr_xpath_node_name_eq(new_val->xpath, "ip")) {
+                    ip_set = true;
+                    strncpy(address_ip, new_val->data.string_val, XPATH_SIZE);
+                } else if (sr_xpath_node_name_eq(new_val->xpath,
+                    "prefix-length")) {
+                    prefix_len_set = true;
+                    prefix_len = new_val->data.uint8_val;
+                }
+
+                if (ip_set && prefix_len_set) {
+                    rc = oi_int_ipv4_conf(interface_name, address_ip,
+                                          prefix_len, true);
+                }
+
+                break;
+
+            case SR_OP_MODIFIED:
+                if (sr_xpath_node_name_eq(old_val->xpath, "ip")) {
+                    old_ip_set = true;
+                    strncpy(old_address_ip, old_val->data.string_val,
+                            XPATH_SIZE);
+                } else if (sr_xpath_node_name_eq(old_val->xpath,
+                    " prefix-length")) {
+                    old_prefix_len_set = true;
+                    old_prefix_len = old_val->data.uint8_val;
+                }
+
+                if (sr_xpath_node_name_eq(new_val->xpath, "ip")) {
+                    ip_set = true;
+                    strncpy(address_ip, new_val->data.string_val, XPATH_SIZE);
+                } else if (sr_xpath_node_name_eq(new_val->xpath,
+                    "prefix-length")) {
+                    prefix_len_set = true;
+                    prefix_len = new_val->data.uint8_val;
+                }
+
+                if (old_ip_set && old_prefix_len_set) {
+                    rc = oi_int_ipv4_conf(interface_name, old_address_ip,
+                                          old_prefix_len, false);
+                    if (0 != rc) {
+                        break;
+                    }
+                }
+
+                if (ip_set && prefix_len_set) {
+                    rc = oi_int_ipv4_conf(interface_name, address_ip,
+                                          prefix_len, true);
+                }
+                break;
+
+            case SR_OP_MOVED:
+                break;
+
+            case SR_OP_DELETED:
+                if (sr_xpath_node_name_eq(old_val->xpath, "ip")) {
+                    old_ip_set = true;
+                    strncpy(old_address_ip, old_val->data.string_val,
+                            XPATH_SIZE);
+                } else if (sr_xpath_node_name_eq(old_val->xpath,
+                    "prefix-length")) {
+                    old_prefix_len_set = true;
+                    old_prefix_len = old_val->data.uint8_val;
+                }
+
+                if (old_ip_set && old_prefix_len_set) {
+                    rc = oi_int_ipv4_conf(interface_name, old_address_ip,
+                                         old_prefix_len, false);
+                }
+                break;
+        }
+
+        if (0 != rc) {
+            sr_xpath_recover(&state);
+
+            sr_free_val(old_val);
+            sr_free_val(new_val);
+
+            sr_free_change_iter(it);
+
+            return SR_ERR_OPERATION_FAILED;
+        }
+
+        sr_xpath_recover(&state);
+
+        sr_free_val(old_val);
+        sr_free_val(new_val);
+    }
+
+    sr_free_change_iter(it);
+    return SR_ERR_OK;
+}
+
diff --git a/src/plugins/openconfig/openconfig_interfaces.h b/src/plugins/openconfig/openconfig_interfaces.h
new file mode 100644
index 0000000..e64b3e2
--- /dev/null
+++ b/src/plugins/openconfig/openconfig_interfaces.h
@@ -0,0 +1,49 @@
+/*
+ * 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 __OPENCONFIG_INTERFACES_H__
+#define __OPENCONFIG_INTERFACES_H__
+
+#include <sysrepo.h>
+
+int openconfig_interface_mod_cb(sr_session_ctx_t *session,
+                                const char *module_name,
+                                sr_notif_event_t event,
+                                void *private_ctx);
+
+int openconfig_interfaces_interfaces_interface_config_cb(
+    sr_session_ctx_t *ds, const char *xpath, sr_notif_event_t event,
+    void *private_ctx);
+
+int openconfig_interfaces_interfaces_interface_subinterfaces_subinterface_oc_ip_ipv4_oc_ip_addresses_oc_ip_address_oc_ip_state_cb(
+    const char *xpath, sr_val_t **values, size_t *values_cnt,
+    uint64_t request_id, void *private_ctx);
+
+int openconfig_interfaces_interfaces_interface_subinterfaces_subinterface_state_cb(
+    const char *xpath, sr_val_t **values, size_t *values_cnt,
+    uint64_t request_id, void *private_ctx);
+
+int openconfig_interfaces_interfaces_interface_state_cb(
+    const char *xpath, sr_val_t **values, size_t *values_cnt,
+    uint64_t request_id, void *private_ctx);
+
+int openconfig_interfaces_interfaces_interface_subinterfaces_subinterface_oc_ip_ipv4_oc_ip_addresses_oc_ip_address_oc_ip_config_cb(
+    sr_session_ctx_t *ds, const char *xpath, sr_notif_event_t event,
+    void *private_ctx);
+
+
+#endif /* __OPENCONFIG_INTERFACES_H__ */
diff --git a/src/plugins/openconfig/sys_util.c b/src/plugins/openconfig/sys_util.c
new file mode 100644
index 0000000..6d3cb67
--- /dev/null
+++ b/src/plugins/openconfig/sys_util.c
@@ -0,0 +1,83 @@
+/*
+ * 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 "sys_util.h"
+#include "sc_vpp_operation.h"
+
+#include <string.h>
+#include <vppinfra/types.h>
+
+char* xpath_find_first_key(const char *xpath, char *key, sr_xpath_ctx_t *state)
+{
+    char *value = NULL;
+
+    if (sr_xpath_next_node((char *)xpath, state) == NULL) {
+        return NULL;
+    }
+
+    while (((value = sr_xpath_node_key_value(NULL,
+            key, state)) == NULL) &&
+            (sr_xpath_next_node(NULL, state) != NULL));
+
+    return value;
+}
+
+// we can call sr_get_item after change is called to see if the value has or has not
+// changed (simpleton solution :D)
+// sr_get_item(sess, "/ietf-interfaces:interfaces/interface[name='eth0']/enabled", &value);
+
+void log_recv_event(sr_notif_event_t event, const char *msg) {
+    const char *event_s;
+    switch (event) {
+        case SR_EV_VERIFY: event_s = "SR_EV_VERIFY"; break;
+        case SR_EV_APPLY: event_s = "SR_EV_APPLY"; break;
+        case SR_EV_ABORT: event_s = "SR_EV_ABORT"; break;
+        default: event_s = "SR_EV_UNKNOWN";
+    }
+    SRP_LOG_DBG("%s: %s\n", msg, event_s);
+}
+
+void log_recv_oper(sr_change_oper_t oper, const char *msg) {
+    const char *oper_s;
+    switch (oper) {
+        case SR_OP_CREATED: oper_s = "SR_OP_CREATED"; break;
+        case SR_OP_DELETED: oper_s = "SR_OP_DELETED"; break;
+        case SR_OP_MODIFIED: oper_s = "SR_OP_MODIFIED"; break;
+        case SR_OP_MOVED: oper_s = "SR_OP_MOVED"; break;
+        default: oper_s = "SR_OP_UNKNOWN"; break;
+    }
+    SRP_LOG_DBG("%s: %s\n", msg, oper_s);
+}
+
+int ip_prefix_split(const char* ip_prefix)
+{
+    //find the slash
+    char* slash = strchr(ip_prefix, '/');
+    if (NULL == slash)
+        return -1;
+
+    //extract subnet mask length
+    char * eptr = NULL;
+    u8 mask = strtoul(slash + 1, &eptr, 10);
+    if (*eptr || mask <= 0)
+        return -1;
+
+    //keep just the address part
+    *slash = '\0';         //replace '/' with 0
+
+    //return mask length
+    return mask;
+}
diff --git a/src/plugins/openconfig/sys_util.h b/src/plugins/openconfig/sys_util.h
new file mode 100644
index 0000000..6c227c3
--- /dev/null
+++ b/src/plugins/openconfig/sys_util.h
@@ -0,0 +1,37 @@
+/*
+ * 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 __SYS_UTIL_H__
+#define __SYS_UTIL_H__
+
+#include <sysrepo.h>
+#include <sysrepo/xpath.h>
+
+#define XPATH_SIZE 2000
+
+typedef struct
+{
+    char xpath_root[XPATH_SIZE];
+    sr_val_t * values;
+    size_t values_cnt;
+} sysr_values_ctx_t;
+
+char* xpath_find_first_key(const char *xpath, char *key, sr_xpath_ctx_t *state);
+void log_recv_event(sr_notif_event_t event, const char *msg);
+void log_recv_oper(sr_change_oper_t oper, const char *msg);
+int ip_prefix_split(const char* ip_prefix);
+
+#endif /* __SYS_UTIL_H__ */