Nginx通过Lua Redis防止CC攻击

access_by_lua_file "/usr/local/nginx/conf/lua/waf.lua";

local get_headers = ngx.req.get_headers
local ua = ngx.var.http_user_agent
local uri = ngx.var.request_uri
local url = ngx.var.host .. uri
local redis = require 'redis'
local red = redis.new()
local CCcount = 20
local CCseconds = 60
local RedisIP = '127.0.0.1'
local RedisPORT = 6379
local blackseconds = 7200
if ua == nil then
    ua = "unknown"
end
if (uri == "/wp-admin.php") then
    CCcount=20
    CCseconds=60
end
red:set_timeout(100)
local ok, err = red.connect(red, RedisIP, RedisPORT)
if ok then
    red.connect(red, RedisIP, RedisPORT)
    function getClientIp()
        IP = ngx.req.get_headers()["X-Real-IP"]
        if IP == nil then
            IP = ngx.req.get_headers()["x_forwarded_for"]
        end
        if IP == nil then
            IP  = ngx.var.remote_addr
        end
        if IP == nil then
            IP  = "unknown"
        end
        return IP
    end
    local token = getClientIp() .. "." .. ngx.md5(url .. ua)
    local req = red:exists(token)
    if req == 0 then
        red:incr(token)
        red:expire(token,CCseconds)
    else
        local times = tonumber(red:get(token))
        if times >= CCcount then
            local blackReq = red:exists("black." .. token)
            if (blackReq == 0) then
                red:set("black." .. token,1)
                red:expire("black." .. token,blackseconds)
                red:expire(token,blackseconds)
                ngx.exit(580)
            else
                ngx.exit(580)
            end
            return
        else
            red:incr(token)
        end
    end
    return
end