+
+int rtnl_message_new_synthetic_error(int error, uint32_t serial, sd_rtnl_message **ret) {
+ struct nlmsgerr *err;
+ int r;
+
+ assert(error <= 0);
+
+ r = message_new(ret, NLMSG_SPACE(sizeof(struct nlmsgerr)));
+ if (r < 0)
+ return r;
+
+ (*ret)->hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct nlmsgerr));
+ (*ret)->hdr->nlmsg_type = NLMSG_ERROR;
+ (*ret)->hdr->nlmsg_seq = serial;
+
+ err = NLMSG_DATA((*ret)->hdr);
+
+ err->error = error;
+
+ return 0;
+}
+
+bool rtnl_message_type_is_route(uint16_t type) {
+ switch (type) {
+ case RTM_NEWROUTE:
+ case RTM_GETROUTE:
+ case RTM_DELROUTE:
+ return true;
+ default:
+ return false;
+ }
+}
+
+bool rtnl_message_type_is_link(uint16_t type) {
+ switch (type) {
+ case RTM_NEWLINK:
+ case RTM_SETLINK:
+ case RTM_GETLINK:
+ case RTM_DELLINK:
+ return true;
+ default:
+ return false;
+ }
+}
+
+bool rtnl_message_type_is_addr(uint16_t type) {
+ switch (type) {
+ case RTM_NEWADDR:
+ case RTM_GETADDR:
+ case RTM_DELADDR:
+ return true;
+ default:
+ return false;
+ }
+}
+
+int rtnl_message_link_get_ifname(sd_rtnl_message *message, const char **ret) {
+ unsigned short type;
+ void *name;
+
+ assert(rtnl_message_type_is_link(message->hdr->nlmsg_type));
+
+ while (sd_rtnl_message_read(message, &type, &name)) {
+ if (type == IFLA_IFNAME) {
+ *ret = name;
+ return 0;
+ }
+ }
+
+ return -ENOENT;
+}