interfaces-plugin: implement IPv6 neighbor IP change callback

src/interfaces/src/plugin/api/interfaces/interface/ipv6/neighbor/change.c

@@ -1,8 +1,16 @@
 #include "change.h"
 #include "plugin/common.h"
+#include "plugin/context.h"
 
+#include <assert.h>
 #include <sysrepo.h>
 
+#include <netlink/route/addr.h>
+#include <netlink/route/link.h>
+#include <netlink/route/neighbour.h>
+
+static int interfaces_interface_ipv6_neighbor_get_link_layer_address(void* priv, sr_session_ctx_t* session, const srpc_change_ctx_t* change_ctx);
+
 int interfaces_interface_ipv6_neighbor_change_link_layer_address_init(void* priv)
 {
     int error = 0;
@@ -44,25 +52,150 @@ int interfaces_interface_ipv6_neighbor_change_ip_init(void* priv)
 int interfaces_interface_ipv6_neighbor_change_ip(void* priv, sr_session_ctx_t* session, const srpc_change_ctx_t* change_ctx)
 {
     int error = 0;
+    void* error_ptr = NULL;
+
+    // strings and buffers
     const char* node_name = LYD_NAME(change_ctx->node);
     const char* node_value = lyd_get_value(change_ctx->node);
+    char path_buffer[PATH_MAX] = { 0 };
+    char interface_name_buffer[100] = { 0 };
+
+    // app context
+    interfaces_ctx_t* ctx = priv;
+
+    // mod changes context
+    interfaces_mod_changes_ctx_t* mod_ctx = &ctx->mod_ctx;
+
+    // libnl
+    struct rtnl_neigh* request_neigh = NULL;
+    struct rtnl_link* current_link = NULL;
+    struct nl_addr* dst_addr = NULL;
+    struct nl_addr* ll_addr = NULL;
 
     SRPLG_LOG_INF(PLUGIN_NAME, "Node Name: %s; Previous Value: %s, Value: %s; Operation: %d", node_name, change_ctx->previous_value, node_value, change_ctx->operation);
 
+    // get node path
+    SRPC_SAFE_CALL_PTR(error_ptr, lyd_path(change_ctx->node, LYD_PATH_STD, path_buffer, sizeof(path_buffer)), error_out);
+
+    // get interface name
+    SRPC_SAFE_CALL_ERR(error, srpc_extract_xpath_key_value(path_buffer, "interface", "name", interface_name_buffer, sizeof(interface_name_buffer)), error_out);
+
+    SRPLG_LOG_INF(PLUGIN_NAME, "Node Path: %s; Interface Name: %s", path_buffer, interface_name_buffer);
+
+    // get link
+    SRPC_SAFE_CALL_PTR(current_link, rtnl_link_get_by_name(mod_ctx->nl_ctx.link_cache, interface_name_buffer), error_out);
+
     switch (change_ctx->operation) {
     case SR_OP_CREATED:
+        // new neighbor
+        request_neigh = rtnl_neigh_alloc();
+
+        // parse destination address
+        SRPC_SAFE_CALL_ERR(error, nl_addr_parse(node_value, AF_INET6, &dst_addr), error_out);
+
+        // get prefix length by using prefix-length or netmask leafs
+        SRPC_SAFE_CALL_ERR_COND(error, error < 0, snprintf(path_buffer, sizeof(path_buffer), INTERFACES_INTERFACES_INTERFACE_YANG_PATH "[name=\"%s\"]/ietf-ip:ipv6/neighbor[ip=\"%s\"]/link-layer-address", interface_name_buffer, node_value), error_out);
+        SRPC_SAFE_CALL_ERR(error, srpc_iterate_changes(ctx, session, path_buffer, interfaces_interface_ipv6_neighbor_get_link_layer_address, NULL, NULL), error_out);
+
+        SRPLG_LOG_INF(PLUGIN_NAME, "Recieved link-layer-address %s for neighbor address %s", mod_ctx->mod_data.ipv6.neighbor.link_layer_address, node_value);
+
+        // parse link-layer address
+        SRPC_SAFE_CALL_ERR(error, nl_addr_parse(mod_ctx->mod_data.ipv6.neighbor.link_layer_address, AF_LLC, &ll_addr), error_out);
+
+        // set addresses to the new neighbor
+        SRPC_SAFE_CALL_ERR(error, rtnl_neigh_set_dst(request_neigh, dst_addr), error_out);
+        rtnl_neigh_set_lladdr(request_neigh, ll_addr);
+
+        // set interface
+        rtnl_neigh_set_ifindex(request_neigh, rtnl_link_get_ifindex(current_link));
+
+        // add neighbor
+        SRPC_SAFE_CALL_ERR(error, rtnl_neigh_add(mod_ctx->nl_ctx.socket, request_neigh, NLM_F_CREATE), error_out);
+
         break;
     case SR_OP_MODIFIED:
+        // should be impossible - address IP can only be created and deleted
+        SRPLG_LOG_ERR(PLUGIN_NAME, "Unsuported operation MODIFY for interface IPv6 neighbor IP leaf");
+        goto error_out;
         break;
     case SR_OP_DELETED:
+        request_neigh = rtnl_neigh_alloc();
+
+        // set interface
+        rtnl_neigh_set_ifindex(request_neigh, rtnl_link_get_ifindex(current_link));
+
+        // parse destination
+        SRPC_SAFE_CALL_ERR(error, nl_addr_parse(node_value, AF_INET6, &dst_addr), error_out);
+
+        // set destination
+        SRPC_SAFE_CALL_ERR(error, rtnl_neigh_set_dst(request_neigh, dst_addr), error_out);
+
+        // remove wanted neighbor
+        SRPC_SAFE_CALL_ERR(error, rtnl_neigh_delete(mod_ctx->nl_ctx.socket, request_neigh, 0), error_out);
+
         break;
     case SR_OP_MOVED:
         break;
     }
 
+    goto out;
+
+error_out:
+    if (error < 0) {
+        SRPLG_LOG_INF(PLUGIN_NAME, "nl_geterror(): %s", nl_geterror(error));
+    }
+    error = -1;
+
+out:
+
+    // re-initialize mod_ctx data
+    if (mod_ctx->mod_data.ipv6.neighbor.link_layer_address) {
+        free(mod_ctx->mod_data.ipv6.neighbor.link_layer_address);
+    }
+    mod_ctx->mod_data.ipv6.neighbor.link_layer_address = NULL;
+    mod_ctx->mod_data.ipv6.neighbor.link_layer_set = false;
+
+    if (request_neigh) {
+        rtnl_neigh_put(request_neigh);
+    }
+
     return error;
 }
 
 void interfaces_interface_ipv6_neighbor_change_ip_free(void* priv)
 {
 }
+
+static int interfaces_interface_ipv6_neighbor_get_link_layer_address(void* priv, sr_session_ctx_t* session, const srpc_change_ctx_t* change_ctx)
+{
+    int error = 0;
+
+    // ctx
+    interfaces_ctx_t* ctx = priv;
+    interfaces_mod_changes_ctx_t* mod_ctx = &ctx->mod_ctx;
+
+    const char* node_name = LYD_NAME(change_ctx->node);
+    const char* node_value = lyd_get_value(change_ctx->node);
+
+    SRPLG_LOG_INF(PLUGIN_NAME, "Node Name: %s; Previous Value: %s, Value: %s; Operation: %d", node_name, change_ctx->previous_value, node_value, change_ctx->operation);
+
+    // this callback should only be called on CREATED operation
+    assert(change_ctx->operation == SR_OP_CREATED);
+
+    // set mod changes prefix length
+    mod_ctx->mod_data.ipv6.neighbor.link_layer_address = strdup(node_value);
+    if (!mod_ctx->mod_data.ipv6.neighbor.link_layer_address) {
+        SRPLG_LOG_ERR(PLUGIN_NAME, "Unable to set link-layer-address value for module changes context");
+        goto error_out;
+    }
+    mod_ctx->mod_data.ipv6.neighbor.link_layer_set = true;
+
+    goto out;
+
+error_out:
+    error = -1;
+    mod_ctx->mod_data.ipv6.neighbor.link_layer_set = false;
+
+out:
+    return error;
+}

src/interfaces/src/plugin/api/interfaces/interface/ipv6/neighbor/change.h

@@ -7,6 +7,7 @@
 int interfaces_interface_ipv6_neighbor_change_link_layer_address_init(void* priv);
 int interfaces_interface_ipv6_neighbor_change_link_layer_address(void* priv, sr_session_ctx_t* session, const srpc_change_ctx_t* change_ctx);
 void interfaces_interface_ipv6_neighbor_change_link_layer_address_free(void* priv);
+
 int interfaces_interface_ipv6_neighbor_change_ip_init(void* priv);
 int interfaces_interface_ipv6_neighbor_change_ip(void* priv, sr_session_ctx_t* session, const srpc_change_ctx_t* change_ctx);
 void interfaces_interface_ipv6_neighbor_change_ip_free(void* priv);