#!/usr/bin/env ruby

# Copyright 2004 Leslie A. Hensley
# hensleyl@papermountain.org
#
#    This program is free software; you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation; either version 2 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program; if not, write to the Free Software
#    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

require 'etc'
require 'webrick'
require 'cgi'
include WEBrick

STORAGE_DIR = "files"
RANDOM_LENGTH = 4
MAX_ACCESS = 50

#override the default mimetype
module WEBrick
	module HTTPUtils
		def mime_type(filename, mime_tab)
			if suffix = (/\.(\w+)$/ =~ filename && $1)
				mtype = mime_tab[suffix.downcase]
			end
			mtype || "text/plain"
		end
		module_function :mime_type
	end
end

def randomString size
  pool = ('a'..'z').to_a + ((0..9).to_a)
  Array.new(size).collect{pool[rand(pool.size)]}.join
end

class URLEncodedFileHandler < HTTPServlet::FileHandler
  @@accessCount = Hash.new {0}

  def set_filename(req, res)
		if req.path == "/"
      res.set_redirect(HTTPStatus::MovedPermanently, "/site/")
			return true
		end
			
		req.path_info.gsub!(/[^\/%+]*$/){|match| CGI.escape(match)}
		begin
			found = super(req, res)
		rescue HTTPStatus::NotFound
      res.set_redirect(HTTPStatus::MovedPermanently, "/site" + req.path)
			return true
		end
		
		if found
			@@accessCount[res.filename] += 1
			if @@accessCount[res.filename] > MAX_ACCESS
      	raise HTTPStatus::Forbidden, "`#{req.path}' limit exceeded"
			end
		end
		found
	end
end

server = HTTPServer.new( 
  :Port => 80,
	:Logger       => WEBrick::Log::new("dropoff_error.log", WEBrick::Log::DEBUG),
	:AccessLog    => [[WEBrick::BasicLog::new("dropoff_access.log"), WEBrick::AccessLog::COMBINED_LOG_FORMAT]],
	:MimeTypes      =>
      HTTPUtils::load_mime_types("/etc/mime.types"))

if(Process.uid == 0)
  nobody = Etc.getpwnam("nobody")
  Dir.chdir("dropoff_home")
  Dir.chroot("dropoff_home")
  Process.egid = Process.gid = nobody.gid
  Process.euid = Process.uid = nobody.uid
end		

HTTPServlet::FileHandler.remove_handler("cgi")
HTTPServlet::FileHandler.remove_handler("rhtml")

server.mount("/", URLEncodedFileHandler, STORAGE_DIR)
server.mount("/site", HTTPServlet::FileHandler, "site")

server.mount_proc('/store') do |request, response|
	baseName = CGI.escape(request.query['name'] && request.query['name'].size > 0 ? request.query['name'][0..150] : 'dropoff.txt')
	
	directoryName = randomString RANDOM_LENGTH
	while(FileTest.exists? directoryName) do
	  directoryName = randomString RANDOM_LENGTH
	end
	
	Dir.mkdir "#{STORAGE_DIR}/#{directoryName}"
	File.open("#{STORAGE_DIR}/#{directoryName}/#{baseName}", 'w') do |file|
		file.print request.query['data'][0..20*1024]
	end
	response.body = "#{ARGV[0]}/#{directoryName}/#{baseName}"
	response['Content-Type'] = 'text/plain'
end

trap('INT'){ server.shutdown }
server.start