generate_204 is not accepted by all Android devices.

[MaStr]

Official answer to /generate_204

curl -v http://connectivitycheck.gstatic.com/generate_204

• Trying 2a00:1450:4001:80b::2003...
• TCP_NODELAY set
• Connected to connectivitycheck.gstatic.com (2a00:1450:4001:80b::2003) port 80 (#0)
  GET /generate_204 HTTP/1.1
  Host: connectivitycheck.gstatic.com
  User-Agent: curl/7.60.0
  Accept: /

HTTP/1.1 204 No Content
Content-Length: 0
Date: Tue, 17 Jul 2018 18:59:28 GMT

What the conversation looks on PirateBox:

GET /generate_204 HTTP/1.1
User-Agent: Dalvik/2.1.0 (Linux; U; Android 7.0; Moto G (4) Build/NPJS25.93-14.7-8)
Host: connectivitycheck.gstatic.com
Connection: Keep-Alive
Accept-Encoding: gzip

HTTP/1.1 204 No Content
X-Powered-By: PHP/7.2.5
Content-type: text/html; charset=UTF-8
Cache-Control: max-age=60, must-revalidate, no-store, no-cache, public
Date: Tue, 24 Apr 2018 00:39:16 GMT
Server: lighttpd/1.4.49

I guess we need to avoid:

X-Powered-By: PHP/7.2.5
Content-type: text/html; charset=UTF-8
Cache-Control: max-age=60, must-revalidate, no-store, no-cache, public
Server: lighttpd/1.4.49

[MaStr]

Ok, I am getting pretty close, but only on the latest lighttpd version.

1. change /etc/php/php.ini expose option to Off

   sudo sed -i -e 's|expose_php = On|expose_php = Off|g' /etc/php/php.ini

2. Change /opt/piratebox/www/generate_204 to:

<?php
// Return an empty page to fake a working internet connection for
// android
ini_set("expose_php","off");
header('Content-Type:', true);
http_response_code(204);
?>

3. Change /opt/piratebox/conf/lighttpd/fastcgi-php-generate203.conf to

$HTTP["url"] =~ "^/generate_204$" {
        fastcgi.server = (
                "" => ((
                                "bin-path" => "/usr/bin/php-cgi",
                                "socket" => "/tmp/php.socket",
                                "max-procs" => 1
                        ))
        )
        setenv.set-response-header  = ( "Content-Length" =>  "0" )
        server.tag =""
        mimetype.use-xattr = "disable"
}

The result renders "only"

$ curl -i http://127.0.0.1:8001/generate_204
HTTP/1.1 204 No Content
Date: Tue, 17 Jul 2018 19:40:16 GMT