From c6119c771d8fdc4f4794e03afd9a4f84b5cdbebe Mon Sep 17 00:00:00 2001
From: Guillaume Mazoyer <gmazoyer@gravitons.in>
Date: Thu, 23 Jul 2015 17:59:59 +0200
Subject: Rework hostname parameter check.

Rename FQDN to hostname which seems more appropriate.
Refactor match_fqdn / match_hostname function to use a more accurate way of
checking a potential hostname.
---
 includes/config.defaults.php | 10 ++++-----
 includes/utils.php           | 50 +++++++++++++++++++++++---------------------
 index.php                    |  4 ++--
 routers/bird.php             | 24 ++++++++++-----------
 routers/cisco.php            | 20 +++++++++---------
 routers/juniper.php          |  8 +++----
 routers/quagga.php           | 24 ++++++++++-----------
 7 files changed, 71 insertions(+), 69 deletions(-)

diff --git a/includes/config.defaults.php b/includes/config.defaults.php
index bd1687f..0fbca1a 100644
--- a/includes/config.defaults.php
+++ b/includes/config.defaults.php
@@ -132,15 +132,15 @@ $config = array(
     ),
     // Documentation for the 'ping' query
     'ping' => array(
-      'command' => 'ping IP_ADDRESS|FQDN',
-      'description' => 'Send 10 pings to the given destination.',
-      'parameter' => 'The parameter must be an IPv4/IPv6 address (without mask) or a fully qualified domain name.<br />RFC1918 addresses, IPv6 starting with FD or FC, and IPv4 reserved ranges (0.0.0.0/8, 169.254.0.0/16, 192.0.2.0/24 and 224.0.0.0/4) may be refused.<br /><br />Example of valid arguments:<br /><ul><li>8.8.8.8</li><li>2001:db8:1337::42</li><li>example.com</li></ul>'
+      'command' => 'ping IP_ADDRESS|HOSTNAME',
+      'description' => 'Send pings to the given destination.',
+      'parameter' => 'The parameter must be an IPv4/IPv6 address (without mask) or a hostname.<br />RFC1918 addresses, IPv6 starting with FD or FC, and IPv4 reserved ranges (0.0.0.0/8, 169.254.0.0/16, 192.0.2.0/24 and 224.0.0.0/4) may be refused.<br /><br />Example of valid arguments:<br /><ul><li>8.8.8.8</li><li>2001:db8:1337::42</li><li>example.com</li></ul>'
     ),
     // Documentation for the 'traceroute' query
     'traceroute' => array(
-      'command' =>'traceroute IP_ADDRESS|FQDN',
+      'command' =>'traceroute IP_ADDRESS|HOSTNAME',
       'description' => 'Display the path to a given destination.',
-      'parameter' => 'The parameter must be an IPv4/IPv6 address (without mask) or a fully qualified domain name.<br />RFC1918 addresses, IPv6 starting with FD or FC, and IPv4 reserved ranges (0.0.0.0/8, 169.254.0.0/16, 192.0.2.0/24 and 224.0.0.0/4) may be refused.<br /><br />Example of valid arguments:<br /><ul><li>8.8.8.8</li><li>2001:db8:1337::42</li><li>example.com</li></ul>'
+      'parameter' => 'The parameter must be an IPv4/IPv6 address (without mask) or a hostname.<br />RFC1918 addresses, IPv6 starting with FD or FC, and IPv4 reserved ranges (0.0.0.0/8, 169.254.0.0/16, 192.0.2.0/24 and 224.0.0.0/4) may be refused.<br /><br />Example of valid arguments:<br /><ul><li>8.8.8.8</li><li>2001:db8:1337::42</li><li>example.com</li></ul>'
     )
   ),
 
diff --git a/includes/utils.php b/includes/utils.php
index 828832f..79888dd 100644
--- a/includes/utils.php
+++ b/includes/utils.php
@@ -142,24 +142,25 @@ function match_ipv6($ip, $ip_only = true) {
 }
 
 /**
- * Test if a given parameter is a valid FQDN or not.
+ * Test if a given parameter is a valid hostname or not.
  *
- * @param  string  $fqdn the parameter to test.
- * @return boolean true if the parameter matches a valid FQDN, false otherwise.
+ * See: http://stackoverflow.com/a/4694816
+ *      http://stackoverflow.com/a/2183140
+ * for references.
+ *
+ * @param  string  $hostname the parameter to test.
+ * @return boolean true if the parameter matches a valid hostname, false
+ *                      otherwise.
  */
-function match_fqdn($fqdn) {
-  $regex = '/(?=^.{4,255}$)(^((?!-)[a-zA-Z0-9-]{1,63}(?<!-)\.)+[a-zA-Z]{2,63}$)/';
-
-  if (empty($fqdn)) {
-    return false;
-  }
-
-  if ((preg_match($regex, $fqdn) === false) ||
-      (preg_match($regex, $fqdn) === 0)) {
-    return false;
-  } else {
-    return true;
-  }
+function match_hostname($hostname) {
+  return (
+    // Valid characters check
+    preg_match('/^(_?[a-z\d](-*[_a-z\d])*)(\.(_?[a-z\d](-*[_a-z\d])*))*$/i', $hostname)
+    // Length check
+    && preg_match('/^.{1,253}$/', $hostname)
+    // Length of each label check
+    && preg_match('/^[^\.]{1,63}(\.[^\.]{1,63})*$/', $hostname)
+  );
 }
 
 /**
@@ -212,19 +213,20 @@ function match_aspath_regex($aspath_regex) {
 }
 
 /**
- * For a given FQDN try to find the corresponding IPv4 or IPv6 address.
+ * For a given hostname try to find the corresponding IPv4 or IPv6 address.
  *
- * If there is multiple addresses attached to the same FQDN it will give the
- * first IPv4 or IPv6 found.
+ * If there is multiple addresses attached to the same hostname it will give
+ * the first IPv4 or IPv6 found.
  *
- * If the FQDN have both IPv4 and IPv6 addresses it will give the first IPv6
- * address found.
+ * If the hostname have both IPv4 and IPv6 addresses it will give the first
+ * IPv6 address found.
  *
- * @param  string $fqdn the FQDN to use to search in the DNS databases.
+ * @param  string $hostname the hostname to use to search in the DNS
+ *                          databases.
  * @return string an IPv4 or IPv6 address based on the DNS records.
  */
-function fqdn_to_ip_address($fqdn) {
-  $dns_record = dns_get_record($fqdn, DNS_A + DNS_AAAA);
+function hostname_to_ip_address($hostname) {
+  $dns_record = dns_get_record($hostname, DNS_A + DNS_AAAA);
 
   // No DNS record found
   if (!$dns_record) {
diff --git a/index.php b/index.php
index 30cae37..3c13478 100644
--- a/index.php
+++ b/index.php
@@ -65,8 +65,8 @@ final class LookingGlass {
     print('<option value="bgp" selected="selected">show route IP_ADDRESS</option>');
     print('<option value="as-path-regex">show route as-path-regex AS_PATH_REGEX</option>');
     print('<option value="as">show route AS</option>');
-    print('<option value="ping">ping IP_ADDRESS|FQDN</option>');
-    print('<option value="traceroute">traceroute IP_ADDRESS|FQDN</option>');
+    print('<option value="ping">ping IP_ADDRESS|HOSTNAME</option>');
+    print('<option value="traceroute">traceroute IP_ADDRESS|HOSTNAME</option>');
     print('</select>');
     print('</div>');
   }
diff --git a/routers/bird.php b/routers/bird.php
index fe9b197..b1a75b8 100644
--- a/routers/bird.php
+++ b/routers/bird.php
@@ -26,21 +26,21 @@ final class Bird extends Router {
   protected function build_ping($destination) {
     $ping = null;
 
-    if (match_fqdn($destination)) {
-      $fqdn = $destination;
-      $destination = fqdn_to_ip_address($fqdn);
+    if (match_hostname($destination)) {
+      $hostname = $destination;
+      $destination = hostname_to_ip_address($hostname);
 
       if (!$destination) {
-        throw new Exception('No A or AAAA record found for '.$fqdn);
+        throw new Exception('No A or AAAA record found for '.$hostname);
       }
     }
 
     if (match_ipv4($destination)) {
       $ping = 'ping '.$this->global_config['tools']['ping_options'].' '.
-        (isset($fqdn) ? $fqdn : $destination);
+        (isset($hostname) ? $hostname : $destination);
     } else if (match_ipv6($destination)) {
       $ping = 'ping6 '.$this->global_config['tools']['ping_options'].' '.
-        (isset($fqdn) ? $fqdn : $destination);
+        (isset($hostname) ? $hostname : $destination);
     } else {
       throw new Exception('The parameter does not resolve to an IPv4/IPv6 address.');
     }
@@ -63,23 +63,23 @@ final class Bird extends Router {
   protected function build_traceroute($destination) {
     $traceroute = null;
 
-    if (match_fqdn($destination)) {
-      $fqdn = $destination;
-      $destination = fqdn_to_ip_address($fqdn);
+    if (match_hostname($destination)) {
+      $hostname = $destination;
+      $destination = hostname_to_ip_address($hostname);
 
       if (!$destination) {
-        throw new Exception('No A or AAAA record found for '.$fqdn);
+        throw new Exception('No A or AAAA record found for '.$hostname);
       }
     }
 
     if (match_ipv4($destination)) {
       $traceroute = $this->global_config['tools']['traceroute4'].' '.
         $this->global_config['tools']['traceroute_options'].' '.
-        (isset($fqdn) ? $fqdn : $destination);
+        (isset($hostname) ? $hostname : $destination);
     } else if (match_ipv6($destination)) {
       $traceroute = $this->global_config['tools']['traceroute6'].' '.
         $this->global_config['tools']['traceroute_options'].' '.
-        (isset($fqdn) ? $fqdn : $destination);
+        (isset($hostname) ? $hostname : $destination);
     } else {
       throw new Exception('The parameter does not resolve to an IPv4/IPv6 address.');
     }
diff --git a/routers/cisco.php b/routers/cisco.php
index 0763bd7..e36a6bf 100644
--- a/routers/cisco.php
+++ b/routers/cisco.php
@@ -27,10 +27,10 @@ final class Cisco extends Router {
     $ping = null;
 
     if (match_ipv4($destination) || match_ipv6($destination) ||
-        match_fqdn($destination)) {
+        match_hostname($destination)) {
       $ping = 'ping '.$destination.' repeat 10';
     } else {
-      throw new Exception('The parameter is not an IPv4/IPv6 address or a FQDN.');
+      throw new Exception('The parameter is not an IPv4/IPv6 address or a hostname.');
     }
 
     if (($ping != null) && $this->has_source_interface_id()) {
@@ -44,25 +44,25 @@ final class Cisco extends Router {
     $traceroute = null;
 
     if (match_ipv4($destination) || match_ipv6($destination) ||
-        (match_fqdn($destination) && !$this->has_source_interface_id())) {
+        (match_hostname($destination) && !$this->has_source_interface_id())) {
       $traceroute = 'traceroute '.$destination;
-    } else if (match_fqdn($destination)) {
-      $fqdn = $destination;
-      $destination = fqdn_to_ip_address($fqdn);
+    } else if (match_hostname($destination)) {
+      $hostname = $destination;
+      $destination = hostname_to_ip_address($hostname);
 
       if (!$destination) {
-        throw new Exception('No A or AAAA record found for '.$fqdn);
+        throw new Exception('No A or AAAA record found for '.$hostname);
       }
 
       if (match_ipv4($destination)) {
-        $traceroute = 'traceroute ip '.(isset($fqdn) ? $fqdn : $destination);
+        $traceroute = 'traceroute ip '.(isset($hostname) ? $hostname : $destination);
       } else if (match_ipv6($destination)) {
-        $traceroute = 'traceroute ipv6 '.(isset($fqdn) ? $fqdn : $destination);
+        $traceroute = 'traceroute ipv6 '.(isset($hostname) ? $hostname : $destination);
       } else {
         throw new Exception('The parameter does not resolve to an IPv4/IPv6 address.');
       }
     } else {
-      throw new Exception('The parameter is not an IPv4/IPv6 address or a FQDN.');
+      throw new Exception('The parameter is not an IPv4/IPv6 address or a hostname.');
     }
 
     if (($traceroute != null) && $this->has_source_interface_id() &&
diff --git a/routers/juniper.php b/routers/juniper.php
index b5c3449..3eb34e5 100644
--- a/routers/juniper.php
+++ b/routers/juniper.php
@@ -27,10 +27,10 @@ final class Juniper extends Router {
     $ping = null;
 
     if (match_ipv4($destination) || match_ipv6($destination) ||
-        match_fqdn($destination)) {
+        match_hostname($destination)) {
       $ping = 'ping count 10 rapid '.$destination;
     } else {
-      throw new Exception('The parameter is not an IPv4/IPv6 address or a FQDN.');
+      throw new Exception('The parameter is not an IPv4/IPv6 address or a hostname.');
     }
 
     if (($ping != null) && $this->has_source_interface_id()) {
@@ -45,10 +45,10 @@ final class Juniper extends Router {
 
     if (match_ipv4($destination)) {
       $traceroute = 'traceroute as-number-lookup '.$destination;
-    } else if (match_ipv6($destination) || match_fqdn($destination)) {
+    } else if (match_ipv6($destination) || match_hostname($destination)) {
       $traceroute = 'traceroute '.$destination;
     } else {
-      throw new Exception('The parameter is not an IPv4/IPv6 address or a FQDN.');
+      throw new Exception('The parameter is not an IPv4/IPv6 address or a hostname.');
     }
 
     if (($traceroute != null) && $this->has_source_interface_id()) {
diff --git a/routers/quagga.php b/routers/quagga.php
index 1944273..9ce6606 100644
--- a/routers/quagga.php
+++ b/routers/quagga.php
@@ -26,21 +26,21 @@ final class Quagga extends Router {
   protected function build_ping($destination) {
     $ping = null;
 
-    if (match_fqdn($destination)) {
-      $fqdn = $destination;
-      $destination = fqdn_to_ip_address($fqdn);
+    if (match_hostname($destination)) {
+      $hostname = $destination;
+      $destination = hostname_to_ip_address($hostname);
 
       if (!$destination) {
-        throw new Exception('No A or AAAA record found for '.$fqdn);
+        throw new Exception('No A or AAAA record found for '.$hostname);
       }
     }
 
     if (match_ipv4($destination)) {
       $ping = 'ping '.$this->global_config['tools']['ping_options'].' '.
-        (isset($fqdn) ? $fqdn : $destination);
+        (isset($hostname) ? $hostname : $destination);
     } else if (match_ipv6($destination)) {
       $ping = 'ping6 '.$this->global_config['tools']['ping_options'].' '.
-        (isset($fqdn) ? $fqdn : $destination);
+        (isset($hostname) ? $hostname : $destination);
     } else {
       throw new Exception('The parameter does not resolve to an IPv4/IPv6 address.');
     }
@@ -63,23 +63,23 @@ final class Quagga extends Router {
   protected function build_traceroute($destination) {
     $traceroute = null;
 
-    if (match_fqdn($destination)) {
-      $fqdn = $destination;
-      $destination = fqdn_to_ip_address($fqdn);
+    if (match_hostname($destination)) {
+      $hostname = $destination;
+      $destination = hostname_to_ip_address($hostname);
 
       if (!$destination) {
-        throw new Exception('No A or AAAA record found for '.$fqdn);
+        throw new Exception('No A or AAAA record found for '.$hostname);
       }
     }
 
     if (match_ipv4($destination)) {
       $traceroute = $this->global_config['tools']['traceroute4'].' '.
         $this->global_config['tools']['traceroute_options'].' '.
-        (isset($fqdn) ? $fqdn : $destination);
+        (isset($hostname) ? $hostname : $destination);
     } else if (match_ipv6($destination)) {
       $traceroute = $this->global_config['tools']['traceroute6'].' '.
         $this->global_config['tools']['traceroute_options'].' '.
-        (isset($fqdn) ? $fqdn : $destination);
+        (isset($hostname) ? $hostname : $destination);
     } else {
       throw new Exception('The parameter does not resolve to an IPv4/IPv6 address.');
     }
-- 
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