nginx禁止IP只允许域名访问

upstream jenkins{
        server 127.0.0.1:8080;
}
server {                                    
        listen 80 default;   #配置此段表示用IP或其他域名访问时跳转到www.baidu.com
        server_name _;
        rewrite ^ http://www.baidu.com$request_uri?;
}
server {
        listen       80;
        server_name  www.twjenkins.com;  #写多一个server配置自定义的域名
        location / {
                #root   html;
                index  index.php index.html index.htm;
                proxy_pass http://jenkins;
                proxy_redirect     off;
                proxy_set_header   Host             $host;
                proxy_set_header   X-Real-IP        $remote_addr;
                proxy_set_header   X-Forwarded-For  $proxy_add_x_forwarded_for;
                proxy_next_upstream error timeout invalid_header http_500 http_502 http_503 http_504;
                proxy_max_temp_file_size   0;
                proxy_connect_timeout      90;
                proxy_send_timeout        90;
                proxy_read_timeout        90;
                proxy_buffer_size          4k;
                proxy_buffers             4 32k;
                proxy_busy_buffers_size    64k;
                proxy_temp_file_write_size 64k;
        }
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
                root   html;
        }

}