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<!-- Module User's Guide -->
     
<chapter>

  <title>&adminguide;</title>
       
  <section>
         
    <title>Overview</title>
         
    <para>
      The IPops module offers operations for handling IP addresses, both IPv4 and IPv6.
    </para>
    <para>
      IPv6 is defined in <ulink url="http://tools.ietf.org/html/rfc2460">RFC 2460</ulink>.
	The same IPv6 address can be represented by different ASCII strings, so binary comparison is required.
	For example, the following IPv6 addresses are equivalent:
    </para>

    <itemizedlist>
      <listitem>
        <para>2001:DB8:0000:0000:0008:0800:200C:417A</para>
      </listitem>
      <listitem>
        <para>2001:DB8:0:0:8:800:200C:417A</para>
      </listitem>
      <listitem>
        <para>2001:DB8::200C:417A</para>
      </listitem>
    </itemizedlist>

    <para>
      	When using IPv6 in an URI (i.e. a SIP URI) the IP address must be written in "IPv6 reference" format 
	(which is the textual representation of the IPv6 enclosed between [ ] symbols).
	An example is <quote>sip:alice@[2001:DB8:0:0:8:800:200C:417A]</quote>. This allows separation of
	address and port number with a :, like <quote>[2001:DB8:0:0:8:800:200C:417A]:5060</quote>.
	This module also allows comparing an IPv6 address with its IPv6 reference representation.
    </para>
           
  </section>
           
  <section>
             
    <title>Dependencies</title>
             
    <section>
      <title>&siprouter; Modules</title>
      <para>
        The following modules must be loaded before this module:
        <itemizedlist>
          <listitem>
            <para>
              <emphasis>No dependencies on other &siprouter; modules</emphasis>
            </para>
          </listitem>
        </itemizedlist>
      </para>
    </section>
               
    <section>
      <title>External Libraries or Applications</title>
      <para>
        The following libraries or applications must be installed before running &siprouter; with this module loaded:
        <itemizedlist>
          <listitem>
            <para>
              <emphasis>No dependencies on external libraries</emphasis>
            </para>
          </listitem>
        </itemizedlist>
      </para>
    </section>
             
  </section>
           
  <section>

    <title>Parameters</title>
             
  </section>
           
  <section>

    <title>Functions</title>
             
    <section id="ipops.f.is_ip">
      <title>
        <function moreinfo="none">is_ip (ip)</function>
      </title>

      <para>
        Returns TRUE if the argument is a valid IPv4, IPv6 or IPv6 reference. FALSE otherwise.
      </para>

      <para>Parameters:</para>

      <itemizedlist>
        <listitem>
          <para>
            <emphasis>ip</emphasis> - String or pseudo-variable containing the IP address to evaluate.
          </para>
        </listitem>
      </itemizedlist>

      <para>
        This function can be used from REQUEST_ROUTE, FAILURE_ROUTE, ONREPLY_ROUTE, BRANCH_ROUTE and LOCAL_ROUTE.
      </para>

      <example>
        <title>
          <function>is_ip</function> usage
        </title>
        <programlisting format="linespecific">
...
if (is_ip($rd)) {
  xlog("L_INFO", "RURI domain is an IP address (not a host name/domain)\n");
}
...
        </programlisting>
      </example>

    </section>

    <section id="ipops.f.is_pur_ip">
      <title>
        <function moreinfo="none">is_pure_ip (ip)</function>
      </title>

      <para>
        Returns TRUE if the argument is a valid IPv4 or IPv6. FALSE otherwise.
      </para>

      <para>Parameters:</para>

      <itemizedlist>
        <listitem>
          <para>
            <emphasis>ip</emphasis> - String or pseudo-variable containing the IP to evaluate.
          </para>
        </listitem>
      </itemizedlist>

      <para>
        This function can be used from REQUEST_ROUTE, FAILURE_ROUTE, ONREPLY_ROUTE, BRANCH_ROUTE and LOCAL_ROUTE.
      </para>

      <example>
        <title>
          <function>is_pure_ip</function> usage
        </title>
        <programlisting format="linespecific">
...
$var(ip) = "::1";
if (is_pure_ip($var(ip))) {
  xlog("L_INFO", "it's IPv4 or IPv6\n");
}
...
        </programlisting>
      </example>

    </section>

    <section id="ipops.f.is_ipv4">
      <title>
        <function moreinfo="none">is_ipv4 (ip)</function>
      </title>

      <para>
        Returns TRUE if the argument is a valid IPv4. FALSE otherwise.
      </para>

      <para>Parameters:</para>

      <itemizedlist>
        <listitem>
          <para>
            <emphasis>ip</emphasis> - String or pseudo-variable containing the IP to evaluate.
          </para>
        </listitem>
      </itemizedlist>

      <para>
        This function can be used from REQUEST_ROUTE, FAILURE_ROUTE, ONREPLY_ROUTE, BRANCH_ROUTE and LOCAL_ROUTE.
      </para>

      <example>
        <title>
          <function>is_ipv4</function> usage
        </title>
        <programlisting format="linespecific">
...
if (is_ipv4("1.2.3.4")) {
  xlog("L_INFO", "it's IPv4\n");
}
...
        </programlisting>
      </example>

    </section>

    <section id="ipops.f.is_ipv6">
      <title>
        <function moreinfo="none">is_ipv6 (ip)</function>
      </title>

      <para>
        Returns TRUE if the argument is a valid IPv6. FALSE otherwise.
      </para>

      <para>Parameters:</para>

      <itemizedlist>
        <listitem>
          <para>
            <emphasis>ip</emphasis> - String or pseudo-variable containing the IP to evaluate.
          </para>
        </listitem>
      </itemizedlist>

      <para>
        This function can be used from REQUEST_ROUTE, FAILURE_ROUTE, ONREPLY_ROUTE, BRANCH_ROUTE and LOCAL_ROUTE.
      </para>

      <example>
        <title>
          <function>is_ipv6</function> usage
        </title>
        <programlisting format="linespecific">
...
if (is_ipv6("1080:0:0:0:8:800:200C:417A")) {
  xlog("L_INFO", "it's IPv6\n");
}
...
        </programlisting>
      </example>

    </section>

    <section id="ipops.f.is_ipv6_reference">
      <title>
        <function moreinfo="none">is_ipv6_reference (ip)</function>
      </title>

      <para>
        Returns TRUE if the argument is a valid IPv6 reference. FALSE otherwise.
      </para>

      <para>Parameters:</para>

      <itemizedlist>
        <listitem>
          <para>
            <emphasis>ip</emphasis> - String or pseudo-variable containing the IP to evaluate.
          </para>
        </listitem>
      </itemizedlist>

      <para>
        This function can be used from REQUEST_ROUTE, FAILURE_ROUTE, ONREPLY_ROUTE, BRANCH_ROUTE and LOCAL_ROUTE.
      </para>

      <example>
        <title>
          <function>is_ipv6_reference</function> usage
        </title>
        <programlisting format="linespecific">
...
if (is_ipv6_reference("[1080:0:0:0:8:800:200C:417A]")) {
  xlog("L_INFO", "it's IPv6 reference\n");
}
...
        </programlisting>
      </example>

    </section>

    <section id="ipops.f.is_ip_type">
      <title>
        <function moreinfo="none">ip_type (ip)</function>
      </title>

      <para>
        Returns the type of the given IP.
      </para>

      <para>Parameters:</para>

      <itemizedlist>
        <listitem>
          <para>
            <emphasis>ip</emphasis> - String or pseudo-variable containing the IP to evaluate.
          </para>
        </listitem>
      </itemizedlist>

      <para>Return value:</para>

      <itemizedlist>
        <listitem>
          <para>
            <emphasis>1</emphasis> - IPv4
          </para>
        </listitem>
        <listitem>
          <para>
            <emphasis>2</emphasis> - IPv6
          </para>
        </listitem>
        <listitem>
          <para>
            <emphasis>3</emphasis> - IPv6 reference
          </para>
        </listitem>
        <listitem>
          <para>
            <emphasis>-1</emphasis> - invalid IP
          </para>
        </listitem>
      </itemizedlist>

      <para>
        This function can be used from REQUEST_ROUTE, FAILURE_ROUTE, ONREPLY_ROUTE, BRANCH_ROUTE and LOCAL_ROUTE.
      </para>

      <example>
        <title>
          <function>ip_type</function> usage
        </title>
        <programlisting format="linespecific">
...
ip_type($var(myip));
switch($rc) {
  case 1:
    xlog("L_INFO", "it's IPv4\n");
    break;
  case 2:
    xlog("L_INFO", "it's IPv6\n");
    break;
  case 3:
    xlog("L_INFO", "it's IPv6 reference\n");
    break;
  case -1:
    xlog("L_INFO", it's type invalid\n");
    break;
}
...
        </programlisting>
      </example>

    </section>

    <section id="ipops.f.detailed_ip_type">
      <title>
        <function moreinfo="none">detailed_ip_type (ip, result)</function>
      </title>

      <para>
        Returns the detailed type of the given IP () (see http://www.iana.org/assignments/ipv6-address-space/ipv6-address-space.txt, http://www.iana.org/assignments/iana-ipv6-special-registry/iana-ipv6-special-registry.txt, RFC 5735 and RFC 6598: PRIVATE, SHARED, LOOPBACK, IPV4MAP, DISCARD etc).
      </para>

      <para>Parameters:</para>

      <itemizedlist>
        <listitem>
          <para>
            <emphasis>ip</emphasis> - String or pseudo-variable containing the IP to evaluate.
          </para>
	</listitem>
        <listitem> 
   	  <para>
            <emphasis>result</emphasis> - String or pseudo-variable containing the detailed type of the IP.
          </para>
          <para>
            <itemizedlist>
              <listitem>  
		<emphasis> IPv4 </emphasis> - PUBLIC, RIVATE, SHARED, LOOPBACK, LINK-LOCAL, RESERVED, TEST-NET, 6TO4-RELAY, MULTICAST, BROADCAST     
 	      </listitem>
	      <listitem>  
		<emphasis> IPv6 </emphasis> - UNSPECIFIED,  LOOPBACK, IPV4MAP, RESERVED, DISCARD, GLOBAL-UNICAST, TEREDO, BMWG, DOCUMENTATION, ORCHID, 6TO4, UNIQUE-LOCAL-UNICAST, LINK-LOCAL-UNICAST, MULTICAST     
 	      </listitem>              
  	    </itemizedlist>		
	  </para>	
        </listitem>
      </itemizedlist>

      <para>Return value:</para>

      <itemizedlist>
        <listitem>
          <para>
            <emphasis>1</emphasis> - successful operation
          </para>
        </listitem>
        <listitem>
          <para>
            <emphasis>negative value</emphasis> - error occurred
          </para>
        </listitem>       
      </itemizedlist>

      <para>
        This function can be used from ALL ROUTES
      </para>

      <example>
        <title>
          <function>detailed_ip_type</function> usage
        </title>
        <programlisting format="linespecific">
...
    detailed_ip_type("192.168.1.2","$var(result)");
    xlog("L_ERR","IP address is of detailed type: $var(result) ");
...
        </programlisting>
      </example>

    </section>

    <section id="ipops.f.detailed_ipv4_type">
      <title>
        <function moreinfo="none">detailed_ipv4_type (ip, result)</function>
      </title>

      <para>
        Returns the detailed type of the given IP () (see RFC 5735 and RFC 6598).
      </para>

      <para>Parameters:</para>

      <itemizedlist>
        <listitem>
          <para>
            <emphasis>ip</emphasis> - String or pseudo-variable containing the IP to evaluate.
          </para>
	</listitem>
        <listitem> 
   	  <para>
            <emphasis>result</emphasis> - String or pseudo-variable containing the detailed type of the IP.
          </para>
          <para>
            <itemizedlist>
              <listitem>  
		<emphasis> IPv4 </emphasis> - PUBLIC, PRIVATE, SHARED, LOOPBACK, LINK-LOCAL, RESERVED, TEST-NET, 6TO4-RELAY, MULTICAST, BROADCAST     
 	      </listitem>	                 
  	    </itemizedlist>		
	  </para>	
        </listitem>
      </itemizedlist>

      <para>Return value:</para>

      <itemizedlist>
        <listitem>
          <para>
            <emphasis>1</emphasis> - successful operation
          </para>
        </listitem>
        <listitem>
          <para>
            <emphasis>negative value</emphasis> - error occurred
          </para>
        </listitem>       
      </itemizedlist>

      <para>
        This function can be used from ALL ROUTES
      </para>

      <example>
        <title>
          <function>detailed_ipv4_type</function> usage
        </title>
        <programlisting format="linespecific">
...
    detailed_ipv4_type("192.168.1.2","$var(result)");
    xlog("L_ERR","IP address is of detailed type: $var(result) ");
...
        </programlisting>
      </example>

    </section>	

    <section id="ipops.f.detailed_ipv6_type">
      <title>
        <function moreinfo="none">detailed_ipv6_type (ip, result)</function>
      </title>

      <para>
        Returns the detailed type of the given IP () (see http://www.iana.org/assignments/ipv6-address-space/ipv6-address-space.txt, http://www.iana.org/assignments/iana-ipv6-special-registry/iana-ipv6-special-registry.txt).
      </para>

      <para>Parameters:</para>

      <itemizedlist>
        <listitem>
          <para>
            <emphasis>ip</emphasis> - String or pseudo-variable containing the IP to evaluate.
          </para>
	</listitem>
        <listitem> 
   	  <para>
            <emphasis>result</emphasis> - String or pseudo-variable containing the detailed type of the IP.
          </para>
          <para>
            <itemizedlist>
              <listitem>  
		<emphasis> IPv6 </emphasis> - UNSPECIFIED,  LOOPBACK, IPV4MAP, RESERVED, DISCARD, GLOBAL-UNICAST, TEREDO, BMWG, DOCUMENTATION, ORCHID, 6TO4, UNIQUE-LOCAL-UNICAST, LINK-LOCAL-UNICAST, MULTICAST    
 	      </listitem>	                 
  	    </itemizedlist>		
	  </para>	
        </listitem>
      </itemizedlist>

      <para>Return value:</para>

      <itemizedlist>
        <listitem>
          <para>
            <emphasis>1</emphasis> - successful operation
          </para>
        </listitem>
        <listitem>
          <para>
            <emphasis>negative value</emphasis> - error occurred
          </para>
        </listitem>       
      </itemizedlist>

      <para>
        This function can be used from ALL ROUTES
      </para>

      <example>
        <title>
          <function>detailed_ipv6_type</function> usage
        </title>
        <programlisting format="linespecific">
...
    detailed_ipv6_type("2001:8d8:7c0:402:217:72:194:30","$var(result)");
    xlog("L_ERR","IP address is of detailed type: $var(result) ");

    detailed_ipv6_type("[2001:8d8:7c0:402:217:72:194:30]","$var(result)");
    xlog("L_ERR","IP address is of detailed type: $var(result) ");	
...
        </programlisting>
      </example>

    </section>	


    <section id="ipops.f.compare_ips">
      <title>
        <function moreinfo="none">compare_ips (ip1, ip2)</function>
      </title>

      <para>
        Returns TRUE if both IP addresses are the same. FALSE otherwise.
	This function also allows comparing an IPv6 address against an IPv6 reference.
      </para>

      <para>Parameters:</para>

      <itemizedlist>
        <listitem>
          <para>
            <emphasis>ip1</emphasis> - String or pseudo-variable containing the first IP to compare.
          </para>
        </listitem>
        <listitem>
          <para>
            <emphasis>ip2</emphasis> - String or pseudo-variable containing the second IP to compare.
          </para>
        </listitem>
      </itemizedlist>

      <para>
        This function can be used from REQUEST_ROUTE, FAILURE_ROUTE, ONREPLY_ROUTE, BRANCH_ROUTE and LOCAL_ROUTE.
      </para>

      <example>
        <title>
          <function>compare_ips</function> usage
        </title>
        <programlisting format="linespecific">
...
if (compare_ips("1080:0000:0000:0000:0008:0800:200C:417A", "[1080::8:800:200C:417A]")) {
  xlog("L_INFO", "both are the same IP\n");
}
...
        </programlisting>
      </example>

    </section>

    <section id="ipops.f.compare_pure_ips">
      <title>
        <function moreinfo="none">compare_pure_ips (ip1, ip2)</function>
      </title>

      <para>
        Returns TRUE if both IP's are the same. FALSE otherwise. This function does NOT 
	allow comparing an IPv6 against an IPv6 reference.
      </para>

      <para>Parameters:</para>

      <itemizedlist>
        <listitem>
          <para>
            <emphasis>ip1</emphasis> - String or pseudo-variable containing the first IP address to compare.
          </para>
        </listitem>
        <listitem>
          <para>
            <emphasis>ip2</emphasis> - String or pseudo-variable containing the second IP address to compare.
          </para>
        </listitem>
      </itemizedlist>

      <para>
        This function can be used from REQUEST_ROUTE, FAILURE_ROUTE, ONREPLY_ROUTE, BRANCH_ROUTE and LOCAL_ROUTE.
      </para>

      <example>
        <title>
          <function>compare_pure_ips</function> usage
        </title>
        <programlisting format="linespecific">
...
if (compare_pure_ips($si, "1080::8:800:200C:417A")) {
  xlog("L_INFO", "both are the same IP\n");
}
...
        </programlisting>
      </example>

    </section>

    <section id="ipops.f.is_ip_rfc1918">
      <title>
        <function moreinfo="none">is_ip_rfc1918 (ip)</function>
      </title>

      <para>
        Returns TRUE if the argument is a private IPv4 according to RFC 1918. FALSE otherwise.
      </para>

      <para>Parameters:</para>

      <itemizedlist>
        <listitem>
          <para>
            <emphasis>ip</emphasis> - String or pseudo-variable containing the IP to evaluate.
          </para>
        </listitem>
      </itemizedlist>

      <para>
        This function can be used from REQUEST_ROUTE, FAILURE_ROUTE, ONREPLY_ROUTE, BRANCH_ROUTE and LOCAL_ROUTE.
      </para>

      <example>
        <title>
          <function>is_ip_rfc1918</function> usage
        </title>
        <programlisting format="linespecific">
...
if (is_ip_rfc1918("10.0.123.123")) {
  xlog("L_INFO", "it's a private IPv4\n");
}
...
        </programlisting>
      </example>

    </section>
 
    <section id="ipops.f.is_in_subnet">
      <title>
        <function moreinfo="none">is_in_subnet (ip, subnets_list)</function>
      </title>

      <para>
        Returns TRUE if the first argument is an IP address within the (CIDR notation)
        subnets list in the second argument. FALSE otherwise.
      </para>

      <para>Parameters:</para>

      <itemizedlist>
        <listitem>
          <para>
            <emphasis>ip</emphasis> - string or pseudo-variable containing the ip to evaluate.
          </para>
        </listitem>
        <listitem>
          <para>
            <emphasis>subnet</emphasis> - string or pseudo-variable containing the (CIDR notation) subnets list to evaluate.
          </para>
        </listitem>
      </itemizedlist>

      <para>
        This function can be used from REQUEST_ROUTE, FAILURE_ROUTE, ONREPLY_ROUTE, BRANCH_ROUTE and LOCAL_ROUTE.
      </para>

      <example>
        <title>
          <function>is_in_subnet</function> usage
        </title>
        <programlisting format="linespecific">
...
if (is_in_subnet("10.0.123.123", "10.0.123.1/24")) {
  xlog("L_INFO", "it's in the subnet\n");
}
...
if (is_in_subnet("10.0.123.123", "10.0.0.0/16,192.168.0.0/24")) {
  xlog("L_INFO", "it's in the subnets\n");
}
...
        </programlisting>
      </example>

    </section>

    <section id="ipops.f.dns_sys_match_ip">
      <title>
        <function moreinfo="none">dns_sys_match_ip(hostname, ipaddr)</function>
      </title>

      <para>
		  Returns TRUE if ipaddr is associated by DNS to hostname. FALSE otherwise. It
		  does not use the internal DNS resolver, but directly getaddrinfo(...). All
		  addresses returned for the hostname are checked. Note that some hosts may
		  return different lists of IP addresses for each query, if the DNS server
		  is configured in that way (e.g., for providing load balancing through DNS).
      </para>

      <para>Parameters:</para>

      <itemizedlist>
        <listitem>
          <para>
			  <emphasis>hostname</emphasis> - string or pseudo-variable containing the hostname.
			  The resulting IP addresses from DNS query are compared with ipaddr.
          </para>
        </listitem>
        <listitem>
          <para>
            <emphasis>ipaddr</emphasis> - string or pseudo-variable containing the ip address.
          </para>
        </listitem>
      </itemizedlist>

      <para>
        This function can be used from ANY_ROUTE.
      </para>

      <example>
        <title>
          <function>dns_sys_match_ip</function> usage
        </title>
        <programlisting format="linespecific">
...
if (!dns_sys_match_ip("myhost.com", "1.2.3.4")) {
    xdbg("ip address not associated with hostname\n");
}
...
        </programlisting>
      </example>

    </section>

    <section id="ipops.f.dns_int_match_ip">
      <title>
        <function moreinfo="none">dns_int_match_ip(hostname, ipaddr)</function>
      </title>

      <para>
		  Returns TRUE if ipaddr is associated by DNS to hostname. FALSE otherwise. It
		  uses internal DNS resolver. At this moment, the function might not check all
		  the IP addresses as returned by dns_sys_match_ip(), because the internal
		  resolver targets to discover the first address to be used for relaying
		  SIP traffic. Thus is better to use dns_sys_match_ip() if the host you want
		  to check has many IP addresses, in different address families (IPv4/6).
      </para>

      <para>Parameters:</para>

      <itemizedlist>
        <listitem>
          <para>
			  <emphasis>hostname</emphasis> - string or pseudo-variable containing the hostname.
			  The resulting IP addresses from DNS query are compared with ipaddr.
          </para>
        </listitem>
        <listitem>
          <para>
            <emphasis>ipaddr</emphasis> - string or pseudo-variable containing the ip address.
          </para>
        </listitem>
      </itemizedlist>

      <para>
        This function can be used from ANY_ROUTE.
      </para>

      <example>
        <title>
          <function>dns_int_match_ip</function> usage
        </title>
        <programlisting format="linespecific">
...
if (!dns_int_match_ip("myhost.com", "1.2.3.4")) {
    xdbg("ip address not associated with hostname\n");
}
...
        </programlisting>
      </example>

    </section>

    <section id="ipops.f.dns_query">
      <title>
        <function moreinfo="none">dns_query(hostname, pvid)</function>
      </title>

      <para>
		  Store the IP addresses and their type that correspond to hostname
		  in a config variable $dns(pvid=>key).
      </para>

      <para>Parameters:</para>

      <itemizedlist>
        <listitem>
          <para>
			  <emphasis>hostname</emphasis> - string or pseudo-variable containing the hostname.
			  The resulting IP addresses from DNS query are compared with ipaddr.
          </para>
        </listitem>
        <listitem>
          <para>
            <emphasis>pvid</emphasis> - container id for script variable.
          </para>
        </listitem>
      </itemizedlist>

      <para>
        This function can be used from ANY_ROUTE.
      </para>

      <example>
        <title>
          <function>dns_query</function> usage
        </title>
        <programlisting format="linespecific">
...
if(dns_query("test.com", "xyz"))
{
    xlog(" number of addresses: $dns(xyz=>count)\n");
    xlog(" ipv4 address found: $dns(xyz=>ipv4)\n");
    xlog(" ipv6 address found: $dns(xyz=>ipv6)\n");
    $var(i) = 0;
    while($var(i)&lt;$dns(xyz=>count)) {
        xlog(" #[$var(i)] type ($dns(xyz=>type[$var(i)]))"
             " addr [$dns(xyz=>addr[$var(i)])]\n");
        $var(i) = $var(i) + 1;
    }
}
...
        </programlisting>
      </example>

    </section>

    <section id="ipops.f.srv_query">
      <title>
        <function moreinfo="none">srv_query(srvcname, pvid)</function>
      </title>

      <para>
Queries DNS SRV records to resolve a service/protocol name into a list of priorities, weights, ports, and targets sorted by priority and weight as outlined in <ulink url="http://tools.ietf.org/html/rfc2782">RFC 2782</ulink>.
      </para>

      <para>Parameters:</para>

      <itemizedlist>
        <listitem>
          <para>
			  <emphasis>srvcname</emphasis> - string or pseudo-variable containing the service/protocol. For example, "_sip._tcp.example.com".
          </para>
        </listitem>
        <listitem>
          <para>
            <emphasis>pvid</emphasis> - container id for script variable.
          </para>
        </listitem>
      </itemizedlist>

      <para>Output:</para>

      <para>
        Returns a positive number indicating success or a negative number when an error is encountered. It can be used from ANY_ROUTE.
      </para>

      <para>
        The $srvquery pseudo-variable (PV) is loaded with the results of the query. Multiple queries can be stored in the PV using the pvid key. Each query contains zero-indexed arrays sorted by priority and weight that contain:
      </para>

      <itemizedlist>
        <listitem>
          <para>
            <emphasis>count</emphasis> - number of records found
          </para>
        </listitem>
        <listitem>
          <para>
            <emphasis>port [index]</emphasis> - port number
          </para>
        </listitem>
        <listitem>
          <para>
            <emphasis>priority [index]</emphasis> - priority number as defined by <ulink url="http://tools.ietf.org/html/rfc2782">RFC 2782</ulink>
          </para>
        </listitem>
        <listitem>
          <para>
            <emphasis>target [index]</emphasis> - target host name
          </para>
        </listitem>
        <listitem>
          <para>
            <emphasis>weight [index]</emphasis> - weight number as defined by <ulink url="http://tools.ietf.org/html/rfc2782">RFC 2782</ulink>
          </para>
        </listitem>
      </itemizedlist>

      <example>
        <title>
          <function>srv_query</function> usage
        </title>
        <programlisting format="linespecific">
...
if (srv_query ("_sip._udp.example.com", "udp") > 0) {
  $var(cnt) = $srvquery(udp=>count);
  $var(i) = 0;
  while ($var(i) &lt; $var(cnt)) {
    xlog ("port[$var(i)] $srvquery(udp=>port[$var(i)])\n");
    xlog ("priority[$var(i)] $srvquery(udp=>priority[$var(i)])\n");
    xlog ("target[$var(i)] $srvquery(udp=>target[$var(i)])\n");
    xlog ("weight[$var(i)] $srvquery(udp=>weight[$var(i)])\n");
    $var(i) = $var(i) + 1;
  }
}
...
        </programlisting>
      </example>
    </section>
 
    <section id="ipops.f.naptr_query">
      <title>
        <function moreinfo="none">naptr_query(domain, pvid)</function>
      </title>

      <para>
         Queries DNS NAPTR records to resolve a domain name into a list of orders, preferences, flags, services, regex, replaces sorted by orders and preferences as outlined in <ulink url="http://tools.ietf.org/html/rfc2915">RFC 2915</ulink>.
      </para>

      <para>Parameters:</para>

      <itemizedlist>
        <listitem>
          <para>
            <emphasis>domain</emphasis> - string or pseudo-variable containing the domain. For example, "example.com".
          </para>
        </listitem>
        <listitem>
          <para>
            <emphasis>pvid</emphasis> - container id for script variable.
          </para>
        </listitem>
      </itemizedlist>

      <para>Output:</para>

      <para>
        Returns a positive number indicating success or a negative number when an error is encountered. It can be used from ANY_ROUTE.
      </para>

      <para>
        The $naptrquery pseudo-variable (PV) is loaded with the results of the query. Multiple queries can be stored in the PV using the pvid key. Each query contains zero-indexed arrays sorted by order and preference that contain:
      </para>

      <itemizedlist>
        <listitem>
          <para>
            <emphasis>count</emphasis> - number of records found
          </para>
        </listitem>
        <listitem>
          <para>
            <emphasis>order [index]</emphasis> - order as defined by <ulink url="http://tools.ietf.org/html/rfc2915">RFC 2915</ulink>
          </para>
        </listitem>
        <listitem>
          <para>
            <emphasis>pref [index]</emphasis> - preference as defined by <ulink url="http://tools.ietf.org/html/rfc2915">RFC 2915</ulink>
          </para>
        </listitem>
        <listitem>
          <para>
            <emphasis>flags [index]</emphasis> - flags
          </para>
        </listitem>
        <listitem>
          <para>
            <emphasis>services [index]</emphasis> - services
          </para>
        </listitem>
        <listitem>
          <para>
            <emphasis>regex [index]</emphasis> - regular expression
          </para>
        </listitem>
        <listitem>
          <para>
            <emphasis>replace [index]</emphasis> - replace
          </para>
        </listitem>
      </itemizedlist>

      <example>
        <title>
          <function>naptr_query</function> usage
        </title>
        <programlisting format="linespecific">
...
if (naptr_query ("example.com", "res") > 0) {
  $var(cnt) = $naptrquery(res=>count);
  $var(i) = 0;
  while ($var(i) &lt; $var(cnt)) {
    xlog ("order[$var(i)] $naptrquery(udp=>order[$var(i)])\n");
    xlog ("pref[$var(i)] $naptrquery(udp=>pref[$var(i)])\n");
    xlog ("flags[$var(i)] $naptrquery(udp=>flags[$var(i)])\n");
    xlog ("services[$var(i)] $naptrquery(udp=>services[$var(i)])\n");
    xlog ("regex[$var(i)] $naptrquery(udp=>regex[$var(i)])\n");
    xlog ("replace[$var(i)] $naptrquery(udp=>replace[$var(i)])\n");
    $var(i) = $var(i) + 1;
  }
}
...
        </programlisting>
      </example>

    </section>

  </section>
 
</chapter>
