Prevention of new types of Http Get Flood attacks at Layer 7 with nginx

default.conf

#
# Hello provide protection for these settings http get flood attacks. 
# Please add this rule to the appropriate sections in your default.conf file.
# Please note that the server {} function does not take place in part become invalid

#
set $add 1;
    set $ban '';

###### Rule 1 ########
if ($http_referer = '-' ) {
    set $ban $ban$add;
}
if ($request_uri = '/') {
    set $ban $ban$add;
}

if ($http_user_agent = 'Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US)') {
    set $ban $ban$add;
}

if ($ban = 111) {
    return 444;
}
#Have a nice day#