######## NAT Traversal module - signaling functions ########
#!ifndef NATHELPER_LOADED
loadmodule "nathelper.so"
#!trydef NATHELPER_LOADED
#!endif
modparam("nathelper", "received_avp", "$avp(AVP_RECV_PARAM)")
modparam("nathelper", "sipping_from", "sip:registrar@MY_HOSTNAME")

#!ifdef WEBSOCKETS_ROLE
#!trydef KZ_NAT_DETECT 83
#!else
#!trydef KZ_NAT_DETECT 19
#!endif

#!trydef KZ_NAT_FIX_SDP_REQUEST 1
#!trydef KZ_NAT_FIX_SDP_REPLY 1
#!trydef KZ_NAT_SDP_TEST 8
#!trydef KZ_NAT_SDP_FIX 10


kazoo.nat_fix_sdp_request = KZ_NAT_FIX_SDP_REQUEST descr "performs request sdp replacement of private addresses"
kazoo.nat_fix_sdp_reply = KZ_NAT_FIX_SDP_REPLY descr "performs reply sdp replacement of private addresses"

####### NAT Traversal Logic ########
route[NAT_SDP]
{
   if( has_body("application/sdp")) {
       if( nat_uac_test(KZ_NAT_SDP_TEST)) {
           xlog("L_DEBUG", "$ci|log|applying sdp nat fix\n");
           $var(ret) = fix_nated_sdp(KZ_NAT_SDP_FIX);
           xlog("L_DEBUG", "$ci|log|result of applying sdp nat fix is $var(ret)\n");
       } else if( is_method("INVITE") && !isflagset(FLAG_INTERNALLY_SOURCED) && is_audio_on_hold()) {
           xlog("L_DEBUG", "$ci|log|applying sdp nat fix for held channel\n");
           $var(ret) = fix_nated_sdp(KZ_NAT_SDP_FIX);
           xlog("L_DEBUG", "$ci|log|result of applying sdp nat fix for held channel is $var(ret)\n");
       }
   }
}

route[NAT_DETECT]
{

   if($sel(cfg_get.kazoo.nat_fix_sdp_request) == 1) {
       route(NAT_SDP);
   }

   if ($Rp == "5080") {
       setflag(FLAG_SKIP_NAT_CORRECTION);
       xlog("L_DEBUG", "$ci|log|skipping nat correction on PORT 5080\n");
   } else {
       if (is_present_hf("Record-Route")) {
           $var(i) = 0;
           $var(rr_count) = $rr_count;
           while($var(i) < $var(rr_count)) {
               $var(rr_base) = $(hdr(Record-Route)[$var(i)]);
               $var(rr_idx) = 0;
               $var(rr) = $(var(rr_base){s.select,$var(rr_idx),,});
               while($var(rr) != $null && $var(rr) != "") {
                   $var(i) = $var(i) + 1;
                   if (!is_myself("$(var(rr){nameaddr.uri})")) {
                       setflag(FLAG_SKIP_NAT_CORRECTION);
                       xlog("L_DEBUG", "$ci|log|skipping nat correction on record-route $(var(rr){nameaddr.uri})\n");
                   }
                   $var(rr_idx) = $var(rr_idx) + 1;
                   $var(rr) = $(var(rr_base){s.select,$var(rr_idx),,});
               }
           }
       }
   }

   if (isflagset(FLAG_SKIP_NAT_CORRECTION)) {
       xlog("L_DEBUG", "$ci|log|skipping nat detection\n");
       return;
   }

   force_rport();

   if(nat_uac_test(KZ_NAT_DETECT)) {
      xlog("L_DEBUG", "$ci|log|detected nat request\n");
      setflag(FLT_NATS);
      if (!is_method("REGISTER")) {
          if(is_first_hop()) set_contact_alias();
      }
   }

}

route[NAT_MANAGE]
{
   if( is_reply() && $sel(cfg_get.kazoo.nat_fix_sdp_reply) == 1) {
       route(NAT_SDP);
   }

   if ( is_request() && isflagset(FLAG_INTERNALLY_SOURCED)) {
        xlog("L_DEBUG", "$ci|log|INTERNAL AND REQUEST => SET FLB_NATB\n");
        setbflag(FLB_NATB);
   }

   if ( is_request() && has_totag() ) {
        xlog("L_DEBUG", "$ci|log|TOTAG AND REQUEST => SET FLB_NATB\n");
        setbflag(FLB_NATB);
   }

   if (!(isflagset(FLT_NATS) || isbflagset(FLB_NATB))) {
        xlog("L_DEBUG", "$ci|log|NOT SETTING\n");
        return;
   }

   if (is_reply()) {
       if(isflagset(FLT_NATS) || isbflagset(FLB_NATB)) {
           if(is_first_hop()) {
               if (!isflagset(FLAG_MANUAL_ALIAS)) {
                   xlog("L_DEBUG", "$ci|log|MANAGE => SET CONTACT ALIAS\n");
                   set_contact_alias();
               }
           } else {
               xlog("L_DEBUG", "$ci|log|MANAGE => NOT FIRST HOP $mb\n");
           }
       }
   }

}

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