<?php if (!defined('PmWiki')) exit();
/*  Copyright 2004 Patrick R. Michaud (pmichaud@pobox.com)
    This file is blocklist.php for PmWiki, 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 script adds blocklisting capabilities to PmWiki.  By default,
    it searches through Main.Blocklist (or whatever pages are specified
    by the $BlocklistPages variable) looking for strings of the form
    "block:something" to be excluded from any posting to the site.
    For example, if Main.Blocklist contains "block:spam.com", then
    any posting to "spam.com" will be disallowed.
    
    Crisses Modifications:
    Looks for patterns that begin with "block:" and
    match to the end of the line or the next "block:", which allows for phrases.  If you add
    block:no spam
    Then posts that contain the phrase "no spam" will be blocked.
    Works with punctuation, also.  Phrases are trimmed, so "block: no spam" works also.

    In addition, the script scans the Main.Blocklist page for 
    IP addresses of the form "a.b.c.d", "a.b.c.*", or "a.b.*.*" and blocks 
    any postings coming from a host matching the IP address or
    address range.

    To use the script, simply place it in the cookbook/ directory
    and add the following line to local/config.php:

        include_once('cookbook/blocklist.php');

    The script also sets the variables $Blocklisted and $WhyBlockedFmt
    so that the administrator can take actions other than simply blocking
    the post.  $Blocklisted counts the number of "offenses" in the attemped post.
    $WhyBlockedFmt is an array containing string messages for
    the reasons the post was blocked.  This makes for easy emails to an admin
    or data transfer to a security script.


USAGE -- this is how I tested it in config.php:
    
    
// ------- blocklist settings -------

// Only bother with this info if this is an edit action
if ($action=='edit') {

    // get the IP address of the poster
    $editip = $_SERVER["REMOTE_ADDR"];
    
    //Uncomment for poster to see a message on the edit page about why they have been blocked.
    # $EnableWhyBlocked = "1";

    // run the script
    include_once('cookbook/blocklist.php');

    // if the script found blocked content
    if ($Blocklisted) {
        
        // compose the contents portion of the email to be sent:

       	// give the page URL posted to
        $contents = "The poster was calling: $ScriptUrl/$pagename\n"; // page URL

        // give the IP address
        $contents .= "Blocked poster is at $editip.\n";
        
        // Let the admin know why the post is blocked
        $contents .= "$WhyBlockedFmt\n\n";
        
        // Give the original post contents, in case it's legit, has
        // additional content that ought to be blocked, or needs
        // to be reported to someone.
        $contents .= "The body of the attempted post was:\n\n" . @$_POST['text'];
        
        // If you want to have the end of the webserver logfile attached, use these lines
        // (If you don't have permissions for reading the mail log, comment out these lines and
        //	report website abuse to your system's administrator.)
        $weblog = '/var/log/httpd/access_log';
        $contents .= "\n\n------Access Log Tail------\n" . `tail -n 20 $weblog`;
        
        
        // compose the email with the following attributes:
        
        // comma-separated addresses to send the mail to:
        $emailto = "crisses"; 
        
        // the subject line to send it out with (includes a "score" for how bad it is):
        $subjectline = "Blocked $WikiTitle Post (Score $Blocklisted)";
        
        // email address the mail should be from:
        $mailfrom = "mantra@eclectictech.net";
            
        // This line sends the mail.  Do not alter (unless you know what you
        //  are doing).  Comment out if you do not want emails regarding blocked posts.
        mail("$emailto","$subjectline","$contents","$mailfrom");

    }
}

// ------- End blocklist settings -------


Other variables available:

$BlocklistPages is an array of the pages that are used for the blocklist.  Default = "Site.Blocklist", and if it exists it includes "Main.Blocklist".  User defining this overrides either file as default.

$BlocklistMessageFmt is the format for the "you've been blocked" statement on the edit screen.

$BlockIPMessageFmt is the message format preceeding the blocked IP address in mails and on the edit screen.

$BlockTextMessageFmt is the message format preceeding the blocked text content in mails and on the edit screen.

$EnableWhyBlocked is a switch for whether or not to display reasons a post is blocked to the user on the edit screen.  For security purposes, the default is off (0).  For reason messages, $EnableWhyBlocked must be enabled (1).

$EnableBlocklistRegex allows blocking via regular expression (PCRE).  The full regular expression including delimiters must be included.

$EnableUnBlocklist allows UNblocking items.  Multiple blocklists can be layered and the unblocklist will unblock items that may be on other blocklists.  

If both regex and unblocklist are enabled, there is the addition of "unregex:" which is a plain text expression that passes over the regex terms, and removes them from the blocklists (only if they exactly match the regex entries - delimiters and all).  It behaves exactly like the "unblock" except it removes items only from the regex lists.

*/

//define the blocklist version number
define(BLOCKLIST_VERSION, '3.0');

$page_name = ResolvePageName($pagename);


// Set default for $BlocklistPages to Site/Blocklist &/OR Main/Blocklist.  
// If customized, remove values that don't exist.
if (!isset($BlocklistPages)) {
	if (PageExists('Site.Blocklist')) $BlocklistPages[] = 'Site.Blocklist';
} else {
	foreach ($BlocklistPages as $key->$value) {
		if (! PageExists($value)) unset($BlocklistPages[$key]);
	}
}

# This script only applies to editing (or the commentbox cookbook script), so 
# if we're not editing or commenting, just return.  Partly borrowed from cmsb-blocklist.php.
# Not sure why he added "diff" to the actions that this runs on.  
if (! ($action == 'edit' || $action == 'comment')
	|| (count($BlocklistPages) < 1)
	|| in_array ($page_name, $BlocklistPages) ) { return; }

//Now that we know we're supposed to be here, set remaining variables
SDV($BlocklistMessageFmt, "<h3 class='wikimessage'>$[This post has been blocked by the administrator]</h3>");
SDV($BlockIPMessageFmt, "$[Remote server matches blocked server IP]: ");
SDV($BlockTextMessageFmt, "$[Content matches blocklist content]: ");
SDV($EnableWhyBlocked, 0); // default is to not let them know
SDV($EnableBlocklistRegex, 0); // enables Perl-compatible regular expression search
SDV($EnableUnBlocklist, 0); // new feature allowing de-listing of blocked items from cumulating blocklists

// get blocklist texts
foreach((array)$BlocklistPages as $key=>$oneblockpage) {
	$pn = FmtPageName($oneblockpage,$pagename);
	$page[$key] = ReadPage($pn);
	$pages[] = $page[$key]['text']; 
}

$check = new BlocklistClass($EnableWhyBlocked, $EnableBlocklistRegex, $EnableUnBlocklist, $BlocklistMessageFmt, $BlockIPMessageFmt, $BlockTextMessageFmt);
$check->blockCheck($pages);
$Blocklisted = $check->Blockcount;


class BlocklistClass {
	var $terms = array(
			'block' => array(),
			'regex' => array(),
			'unblock' => array(),
			'unregex' => array());
		
	var $regex = array();
	var $unblock = array();
	
	function BlocklistClass($EnableWhyBlocked, $EnableBlocklistRegex, $EnableUnBlocklist, $BlocklistMessageFmt, $BlockIPMessageFmt, $BlockTextMessageFmt) {
		$this->why = $EnableWhyBlocked;
		$this->regex = $EnableBlocklistRegex;
		$this->unblock = $EnableUnBlocklist;
		$this->blockmsg = $BlocklistMessageFmt;
		$this->ipmsg = $BlockIPMessageFmt;
		$this->textmsg = $BlockTextMessageFmt;
	}
	
	// feed me an array of blocklist page texts
	function blockCheck($blocktexts) {

		$this->rawtexts = $blocktexts;
		$this->checkBlockIP();

		if (($this->why == 0) && ($this->Blockcount > 0)) {$this->printMessages(); return;}
		$this->makeBlockTerms();

		if ($this->unblock) $this->removeTerms('block');

		if ($this->regex) {
			$this->makeRegexTerms();

			if ($this->unblock) $this->removeTerms('regex');
		}
		$this->checkBlockTerms();

		if (($this->why == 0) && ($this->Blockcount > 0)) {$this->printMessages(); return;}
		
		if ($this->regex) $this->checkRegexTerms();

		if ($this->Blockcount > 0) {$this->printMessages(); return;}
	}

	function checkBlockIP() {
		// Prep for IP checking
		list($ipa,$ipb,$ipc,$ipd) = explode('.', $_SERVER['REMOTE_ADDR']);

		// Check ip address against each blocklist page text
		foreach ($this->rawtexts as $text){
			if (preg_match("/(\\D$ipa\\.$ipb\\.(\\D|$ipc)\\.($ipd)?\\D)/", $text, $matchedip)) {
				$this->Blockcount++ ; // increment counter
				$this->whymsg .= $this->ipmsg . $matchedip[1] . "\n"; // add a reason why the page is blocked
				return;
			}
		}
	}

	
	function makeBlockTerms() {
		foreach ($this->rawtexts as $text){
			//catch and fix multiple block:'s on a single line and leading whitespace 
			//(allows legacy format)
			$legacyfix['/\\s*block:/'] = '\nblock:';
			if ($this->unblock) $legacyfix['/\\s*unblock:/'] = '\nunblock:';
			if ($this->regex) {$legacyfix['/\\s*regex:/'] = '\nregex:';
				if ($this->unregex) $legacyfix['/\\s*unregex:/'] = '\nunregex:';
			}
				
			// Make an array of text that follows "block:" incl spaces & punct
			preg_match_all('/block:\s*(.+)/', $text, $blockterms);
			
			$this->terms['block'] = array_merge($this->terms['block'], $blockterms[1]);
		}
	}

	
	function removeTerms($type) {
		foreach ($this->rawtexts as $text){
			//catch and fix multiple block:'s on a single line and leading whitespace 
			//(allows legacy format)
				
			// Make an array of text that follows "unblock:" incl spaces & punct
			preg_match_all("/un$type:\s*(.+)/", $text, $unblockterms);
			
			$this->terms["un$type"] = array_merge($this->terms["un$type"], $unblockterms[1]);
		}
		
		// now unblock the terms
		
		foreach ($this->terms["un$type"] as $value){
			$keys = array_keys($this->terms[$type], $value);
			if (count($keys)>0){
				foreach ($keys as $key) unset($this->terms[$type][$key]);
			}
		}
	}
	
	function makeRegexTerms() {
		foreach ($this->rawtexts as $text){
	
			// Make an array of text that follows "regex:" incl spaces & punct
			preg_match_all('/regex:(.+)/', $text, $regexterms);
		
			$this->terms['regex'] = array_merge($this->terms['regex'], $regexterms[1]);
		}
	}


	function checkBlockTerms() {
		//compares entries in the blocklist to the post content
		// Check posted page content against blocklist
		// Note:  matches only on first, not repeated, offenses-per-criteria
		// If score/reasons are not being tallied, break out.
		foreach ($this->terms['block'] as $blockitem){
			if (stristr(@$_POST['text'], $blockitem)) {
				$this->Blockcount++;
				if ($this->why == 0) return;
				$this->whymsg .= $this->textmsg . $blockitem . "\n";
			}
		}
	}

	
	function checkRegexTerms() {
		//compares entries in the regex list to the post content
		// Note:  matches only on first, not repeated, offenses-per-criteria
		// If score/reasons are not being tallied, break out.
		foreach ($this->terms['regex'] as $oneregex){
			if (preg_match($oneregex, @$_POST['text'], $regexmatch)) {
				$this->Blockcount++;
				if ($this->why == 0) return;
				$this->whymsg .= $this->textmsg . $regexmatch[0] . "\n";
			}
		}

	}
	
	function printMessages(){
		global $EnablePost;
		global $MessagesFmt;
		$EnablePost = 0; 
		unset($_POST['post']); 
		unset($_POST['postattr']);
		unset($_POST['postedit']);
		// let the poster know they've been blocked
		$MessagesFmt[] .= $this->blockmsg;
		// if required, provide reasons
		if ($this->why == 1) $MessagesFmt[] = '<pre class="blocklistmessage">' . $this->whymsg . "</pre>";
	}
}