local _M = {} function _M.reload() local httpc = require("resty.http").new() -- fetch blocklist records (all blocked skylink hashes) -- 10.10.10.10 points to sia service (alias not available when using resty-http) local res, err = httpc:request_uri("http://10.10.10.10:9980/skynet/blocklist", { headers = { ["User-Agent"] = "Sia-Agent", } }) -- fail whole request in case this request failed, we want to make sure -- the blocklist is pre cached before serving first skylink if err or (res and res.status ~= ngx.HTTP_OK) then ngx.log(ngx.ERR, "Failed skyd service request /skynet/blocklist: ", err or ("[HTTP " .. res.status .. "] " .. res.body)) ngx.status = (err and ngx.HTTP_INTERNAL_SERVER_ERROR) or res.status ngx.header["content-type"] = "text/plain" ngx.say(err or res.body) return ngx.exit(ngx.status) elseif res and res.status == ngx.HTTP_OK then local json = require('cjson') local data = json.decode(res.body) -- mark all existing entries as expired ngx.shared.blocklist:flush_all() -- check if blocklist is table (it is null when empty) if type(data.blocklist) == "table" then -- set all cache entries one by one (resets expiration) for i, hash in ipairs(data.blocklist) do ngx.shared.blocklist:set(hash, true) end end -- ensure that init flag is persisted ngx.shared.blocklist:set("__init", true) -- remove all leftover expired entries ngx.shared.blocklist:flush_expired() end end function _M.is_blocked(skylink) -- make sure that blocklist has been preloaded if not ngx.shared.blocklist:get("__init") then _M.reload() end -- hash skylink before comparing it with blocklist local hash = require("skynet.skylink").hash(skylink) -- we need to use get_stale because we are expiring previous -- entries when the blocklist is reloading and we still want -- to block them until the reloading is finished return ngx.shared.blocklist:get_stale(hash) == true end -- exit with 416 illegal content status code function _M.exit_illegal() ngx.status = ngx.HTTP_ILLEGAL ngx.header["content-type"] = "text/plain" ngx.say("Unavailable For Legal Reasons") return ngx.exit(ngx.status) end return _M