proxy.pac.tail

// TODO: binary search is sufficient
// TODO: test chrome, IE
// TODO: merge trees
// TODO: adblock
// BUG: dnsResolve will fail on ipv6 hosts

// a tree representing a bounch of network (ip address with prefix)
// an ip is in tree if a braunch in ip_tree matches an ip
//var cn_tree = [...];	// auto-generated from chnroutes.txt by iplist2js.py
////var paper_tree = [...];	// auto-generated from paper-sites.txt by iplist2js.py
//var reserved_tree = [...];	// auto-generated from reserved.txt by iplist2js.py
//var paper_list = [...];	// auto-generated from paper-domains.txt by iplist2js.py

// var proxy = 'PROXY 127.0.0.1:8087';
var proxy = 'SOCKS5 127.0.0.1:1080';
var blackhole = 'PROXY 127.0.0.1:8086';
var noproxy = 'DIRECT';


var domain_in_list = function(domain, domain_list)
{
	'use strict';
	domain = domain.toLowerCase();
	
	function endsWith(str, suffix)
	{
		return str.indexOf(suffix, str.length - suffix.length) !== -1;
	}
	
	for(var i = 0; i < domain_list.length; i++)
	{
		var item = domain_list[i];
		if(domain === item)
		{
			return true;
		}
		if(endsWith(domain, '.'+item))
		{
			return true;
		}
	}
	return false;
};

var ip_in_tree = function(ip, ip_tree)
{
	'use strict';
	// convert a ip string to a array of binary bits
	var ip_to_bin_array  = function(ip)
	{
		// convert a byte to a array of binary bits
		var byte_to_array = function(byte)
		{
			var masks = [
				0b10000000, 0b01000000, 0b00100000, 0b00010000,
				0b00001000, 0b00000100, 0b00000010, 0b00000001
			];
			var ret = [];
			for(var i = 0; i < 8; i++)
			{
				ret.push(Number(Boolean(byte & masks[i])));
			}
			return ret;
		};
		
		var ip_array = ip.split('.').map(function(element, b, c){ return parseInt(element); });
		
		var bin_array = [];
		for(var i = 0; i < 4; i++)
		{
			var b = ip_array[i];
			bin_array = bin_array.concat(byte_to_array(b));
		}
		
		return bin_array;
	};

	var bin_in_tree = function(tree, bin)
	{
		var tree_is_end = function(node)
		{
			return node[0] === null && node[1] === null;
		};
		
		if(tree_is_end(tree))
		{
			return true;
		}
		else if(tree[bin[0]] === null)
		{
			return false;
		}
		else
		{
			return bin_in_tree(tree[bin[0]], bin.slice(1));
		}
	};

	var bin_array = ip_to_bin_array(ip);
	return bin_in_tree(ip_tree, bin_array);
};

function FindProxyForURL(url, host)
{
	'use strict';
	if(localHostOrDomainIs(host, "host.in.white.list"))
	{
		return noproxy; 
	}
	
	var ip = dnsResolve(host);
	if(!ip || ip_in_tree(ip, cn_tree) || ip_in_tree(ip, reserved_tree) || domain_in_list(host, paper_list))
	{
		return noproxy;
	}
	else
	{
		return proxy;
	}
}