From 0a14913fe54e269e535c1f66f715823fa731c843 Mon Sep 17 00:00:00 2001
From: Pascal Kriete <pascal@pascalkriete.com>
Date: Thu, 7 Jun 2012 16:15:51 -0400
Subject: Adding IPv6 support to the Input and Form_validation libraries.

---
 system/core/Input.php                     | 134 +++++++++++++++++++++++++++++-
 system/libraries/Form_validation.php      |   5 +-
 user_guide/libraries/form_validation.html |   2 +-
 user_guide/libraries/input.html           |   2 +-
 4 files changed, 136 insertions(+), 7 deletions(-)

diff --git a/system/core/Input.php b/system/core/Input.php
index 9bfb5f1fb..4b7622cbe 100755
--- a/system/core/Input.php
+++ b/system/core/Input.php
@@ -365,13 +365,66 @@ class CI_Input {
 	/**
 	* Validate IP Address
 	*
+	* @access	public
+	* @param	string
+	* @param	string	ipv4 or ipv6
+	* @return	bool
+	*/
+	public function valid_ip($ip, $which = '')
+	{
+		$which = strtolower($which);
+
+		// First check if filter_var is available
+		if (is_callable('filter_var'))
+		{
+			switch ($which) {
+				case 'ipv4':
+					$flag = FILTER_FLAG_IPV4;
+					break;
+				case 'ipv6':
+					$flag = FILTER_FLAG_IPV6;
+					break;
+				default:
+					$flag = '';
+					break;
+			}
+
+			return filter_var($ip, FILTER_VALIDATE_IP, $flag) !== FALSE;
+		}
+		
+		// If it's not we'll do it manually
+		if ($which != 'ipv6' OR $which != 'ipv4')
+		{
+			if (strpos($ip, ':') !== FALSE)
+			{
+				$which = 'ipv6';
+			}
+			elseif (strpos($ip, '.') !== FALSE)
+			{
+				$which = 'ipv4';
+			}
+			else
+			{
+				return FALSE;
+			}
+		}
+		
+		$func = '_valid_'.$which;
+		return $this->$func($ip);
+	}
+	
+	// --------------------------------------------------------------------
+	
+	/**
+	* Validate IPv4 Address
+	*
 	* Updated version suggested by Geert De Deckere
 	*
-	* @access	public
+	* @access	protected
 	* @param	string
-	* @return	string
+	* @return	bool
 	*/
-	function valid_ip($ip)
+	protected function _valid_ipv4($ip)
 	{
 		$ip_segments = explode('.', $ip);
 
@@ -385,6 +438,7 @@ class CI_Input {
 		{
 			return FALSE;
 		}
+		
 		// Check each segment
 		foreach ($ip_segments as $segment)
 		{
@@ -398,6 +452,80 @@ class CI_Input {
 
 		return TRUE;
 	}
+		
+	// --------------------------------------------------------------------
+	
+	/**
+	* Validate IPv6 Address
+	*
+	* @access	protected
+	* @param	string
+	* @return	bool
+	*/
+	protected function _valid_ipv6($str)
+	{
+		// 8 groups, separated by :
+		// 0-ffff per group
+		// one set of consecutive 0 groups can be collapsed to ::
+		
+		$groups = 8;
+		$collapsed = FALSE;
+		
+		$chunks = array_filter(
+			preg_split('/(:{1,2})/', $str, NULL, PREG_SPLIT_DELIM_CAPTURE)
+		);
+		
+		// Rule out easy nonsense
+		if (current($chunks) == ':' OR end($chunks) == ':')
+		{
+			return FALSE;
+		}
+		
+		// PHP supports IPv4-mapped IPv6 addresses, so we'll expect those as well
+		if (strpos(end($chunks), '.') !== FALSE)
+		{
+			$ipv4 = array_pop($chunks);
+			
+			if ( ! $this->_valid_ipv4($ipv4))
+			{
+				return FALSE;
+			}
+			
+			$groups--;
+		}
+		
+		while ($seg = array_pop($chunks))
+		{
+			if ($seg[0] == ':')
+			{
+				if (--$groups == 0)
+				{
+					return FALSE;	// too many groups
+				}
+				
+				if (strlen($seg) > 2)
+				{
+					return FALSE;	// long separator
+				}
+				
+				if ($seg == '::')
+				{
+					if ($collapsed)
+					{
+						return FALSE;	// multiple collapsed
+					}
+					
+					$collapsed = TRUE;
+				}
+			}
+			elseif (preg_match("/[^0-9a-f]/i", $seg) OR strlen($seg) > 4)
+			{
+				return FALSE; // invalid segment
+			}
+		}
+
+		return $collapsed OR $groups == 1;
+	}
 
 	// --------------------------------------------------------------------
 
diff --git a/system/libraries/Form_validation.php b/system/libraries/Form_validation.php
index a34809e05..9aab5da4b 100644
--- a/system/libraries/Form_validation.php
+++ b/system/libraries/Form_validation.php
@@ -1079,11 +1079,12 @@ class CI_Form_validation {
 	 *
 	 * @access	public
 	 * @param	string
+	 * @param	string "ipv4" or "ipv6" to validate a specific ip format
 	 * @return	string
 	 */
-	public function valid_ip($ip)
+	public function valid_ip($ip, $which = '')
 	{
-		return $this->CI->input->valid_ip($ip);
+		return $this->CI->input->valid_ip($ip, $which);
 	}
 
 	// --------------------------------------------------------------------
diff --git a/user_guide/libraries/form_validation.html b/user_guide/libraries/form_validation.html
index 2028bcd2c..f13ece0d7 100644
--- a/user_guide/libraries/form_validation.html
+++ b/user_guide/libraries/form_validation.html
@@ -1058,7 +1058,7 @@ POST array:</p>
 	<tr>
 		<td class="td"><strong>valid_ip</strong></td>
 		<td class="td">No</td>
-		<td class="td">Returns FALSE if the supplied IP is not valid.</td>
+		<td class="td">Returns FALSE if the supplied IP is not valid. Accepts an optional parameter of "IPv4" or "IPv6" to specify an IP format.</td>
 		<td class="td">&nbsp;</td>
 	</tr>
 
diff --git a/user_guide/libraries/input.html b/user_guide/libraries/input.html
index 10c84a9ea..c69be891e 100644
--- a/user_guide/libraries/input.html
+++ b/user_guide/libraries/input.html
@@ -248,7 +248,7 @@ else<br />
 {<br />
 &nbsp;&nbsp;&nbsp;&nbsp; echo 'Valid';<br />
 }</code>
-
+<p>Accepts an optional second string parameter of "IPv4" or "IPv6" to specify an IP format. The default checks for both formats.</p> 
 
 <h2>$this->input->user_agent()</h2>
 <p>Returns the user agent (web browser) being used by the current user. Returns FALSE if it's not available.</p>
-- 
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