nginx中if判断实现多重判断

if ($remote_addr ~ "^(12.34|56.78)" && $http_user_agent ~* "spider") {
    return 403;
}

set $flag 0;
if ($remote_addr ~ "^(12.34|56.78)") {
    set $flag "${flag}1";
}
if ($http_user_agent ~* "spider") {
    set $flag "${flag}2";
}
if ($flag = "012") {
    return 403;
}

if ($request_uri ~ "xxx.php?xxx") {
set $iftmp Y;
}
if ($http_user_agent ~ "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; SV1)") {
set $iftmp "${iftmp}Y";
}
if ($iftmp = YY) { return 400;}
location / {
proxy_pass https://172.0.0.11;
}