unblocker/lib/get-real-url.js

Web proxy for evading internet censorship & general-purpose library for rewriting remote websites.

var URL = require('url');

module.exports = function(config) {


    // occasionally things try to "fix" http:// in the path portion of the URL by merging the slashes and thereby breaking everything
    var RE_UNMERGE_SLASHES = /^(https?:\/)([^\/])/i;
    // fix for #74 - fix cases where the /proxy/http:// part occurs twice - can happen with JS that tries to detect the protocol and build a URL from multiple strings
    // accepts 1-3 slashes in the middle (assuming the prefix starts with a slash)
    // note: the prefix only appears in the regex once because the other will have already been trimmed out.
    var RE_DUOBLE_PREFIX = new RegExp('^https?:/?/?' + config.prefix + '(https?://)', 'i');
    /**
     * Takes a /proxy/http://site.com url from a request or a referer and returns the http://site.com/ part
     *
     * @todo: come up with a better name for this
     */
    function getRealUrl(path) {
        var uri = URL.parse(path),
            real_url = uri.path.substr(config.prefix.length);
        real_url = real_url.replace(RE_DUOBLE_PREFIX, "$1");
        real_url = real_url.replace(RE_UNMERGE_SLASHES, "$1/$2");
        return real_url;
    }

    return getRealUrl;
};