FlatVyosControlPlaneExtractor.java

package org.batfish.grammar.flatvyos;

import java.util.Set;
import java.util.TreeSet;

import org.antlr.v4.runtime.ParserRuleContext;
import org.antlr.v4.runtime.Token;
import org.antlr.v4.runtime.tree.ParseTreeWalker;
import org.batfish.common.BatfishException;
import org.batfish.common.util.CommonUtil;
import org.batfish.datamodel.DiffieHellmanGroup;
import org.batfish.datamodel.EncryptionAlgorithm;
import org.batfish.datamodel.IkeAuthenticationMethod;
import org.batfish.datamodel.Ip;
import org.batfish.datamodel.LineAction;
import org.batfish.datamodel.Prefix;
import org.batfish.grammar.ControlPlaneExtractor;
import org.batfish.grammar.flatvyos.FlatVyosParser.*;
import org.batfish.common.Warnings;
import org.batfish.representation.vyos.BgpNeighbor;
import org.batfish.representation.vyos.BgpProcess;
import org.batfish.representation.vyos.EspGroup;
import org.batfish.representation.vyos.EspProposal;
import org.batfish.representation.vyos.HashAlgorithm;
import org.batfish.representation.vyos.IkeGroup;
import org.batfish.representation.vyos.IkeProposal;
import org.batfish.representation.vyos.Interface;
import org.batfish.representation.vyos.InterfaceType;
import org.batfish.representation.vyos.IpsecPeer;
import org.batfish.representation.vyos.PfsSource;
import org.batfish.representation.vyos.PrefixList;
import org.batfish.representation.vyos.PrefixListRule;
import org.batfish.representation.vyos.RouteMap;
import org.batfish.representation.vyos.RouteMapMatch;
import org.batfish.representation.vyos.RouteMapMatchPrefixList;
import org.batfish.representation.vyos.RouteMapRule;
import org.batfish.representation.vyos.StaticNextHopRoute;
import org.batfish.representation.vyos.VyosConfiguration;
import org.batfish.vendor.VendorConfiguration;

public class FlatVyosControlPlaneExtractor extends FlatVyosParserBaseListener
      implements ControlPlaneExtractor {

   private static final String F_INTERFACES_ADDRESS_DHCP = "interfaces address dhcp";

   public static final String SALT = "3H28tI(LMcx.k_Q9xZ*G8\".,?wL~cMMaQS~3y$j-@znQi3{2A%m/@{n)QMgDy=xb&#.C?.'.*,V>a<Il=4=x$Im#alhhDTvO(Hnv^M$l\\Bu:awuW<ILJ?*\"D+bAkG@5t$:&;>BdpcsZ]*RyDfZ7XYEL5z8!Jk\"d-+WRiX1[Kn<wK.mz7?x1W`1^sxTZ&FKWh}Q?&}/iFfaM$!%R?gQ_5k}/)s5'SbVp,gsiaN4yo,/IG{=o&~Hr`M>ykiagEb[Ov%9'_)&G]^rkV2#ITp(g\"efG/#B;sl)_<&Nt=2@f4l-<\\\"El<g?dit82gYT`%-k:c!pLg|YQ8T2fv&Z}hIkZz[aD`6GIkC8L#i{j>-zX3GCt{BW6VHdlN.ku)>NrU%Zp+nK;6eMQufd$}b8xyr6PW/:M\\y\\Z-}1x0T\"YtxDjEnoV/)Yu%<x.HtO|Q4}vQFXQ*%XybfZ9%`P79yqp~)zDQ7pm~}VxLJRs.c@djs0xUrZabAW?K19iK9?|33K{`kyG.GH7(8VxnA+E|'?7+~=Jl1*Gf>5a#.{o>>X`R4nF?|t$X\"6#m6ql>ZM/<49sms&2Q<g~-|_j7&;CeZ3TK3dV,H*G715PUFr+xx|}jpYC?3b4,sU^F~G|0LaS$i,;mG2.u!4K4qN\\8})RL-^,HD=-<a~h5FnRWJ./|X\"Vov3tLaWBRKx(^>|M?2x&RuVY4hf27^~PRtWdd\"iJ2_S(2!_^H\\y:U[>Py9lQ\"h#bk2]G~UJ`.qX3\\tLtL=?u,C/{/&aH*ZP:?eLYmf6xxz7o~E(tld`+::IfL6~d0K`$Pj=\\I=^uOaK^VM?@TH2Y?2LIZ'T%]P~f>pK%h_X]cZ8wx3A/`B2{^CoqrUr;IBIx6c3bxN<l$xAV5es_of*[iK3-kN{7KQh%WF%!u(,DQ6ulvFV&R6Cd4c]Aw-Z6p:\\=c8sp_S\"8ER;l$muldWlZ`V@E$V2K_ztsl(9.gK7wR<DC0DS)$ggN7GxbtsjrBq#NT\\5EudN2WIMHYDSW]inc&$;e<C";

   private static LineAction toAction(Line_actionContext ctx) {
      if (ctx.DENY() != null) {
         return LineAction.REJECT;
      }
      else if (ctx.PERMIT() != null) {
         return LineAction.ACCEPT;
      }
      else {
         throw new BatfishException("invalid line_action: " + ctx.getText());
      }
   }

   private static HashAlgorithm toHashAlgorithm(Hash_algorithmContext ctx) {
      if (ctx.MD5() != null) {
         return HashAlgorithm.MD5;
      }
      else if (ctx.SHA1() != null) {
         return HashAlgorithm.SHA1;
      }
      else if (ctx.SHA256() != null) {
         return HashAlgorithm.SHA256;
      }
      else if (ctx.SHA384() != null) {
         return HashAlgorithm.SHA384;
      }
      else if (ctx.SHA512() != null) {
         return HashAlgorithm.SHA512;
      }
      else {
         throw new BatfishException("Invalid hash algorithm");
      }
   }

   private static int toInteger(Token t) {
      String text = t.getText();
      try {
         int result = Integer.parseInt(text);
         return result;
      }
      catch (NumberFormatException e) {
         throw new BatfishException("Not an integer: \"" + text + "\"", e);
      }
   }

   private static InterfaceType toInterfaceType(Interface_typeContext ctx) {
      if (ctx.BONDING() != null) {
         return InterfaceType.BONDING;
      }
      else if (ctx.BRIDGE() != null) {
         return InterfaceType.BRIDGE;
      }
      else if (ctx.DUMMY() != null) {
         return InterfaceType.DUMMY;
      }
      else if (ctx.ETHERNET() != null) {
         return InterfaceType.ETHERNET;
      }
      else if (ctx.INPUT() != null) {
         return InterfaceType.INPUT;
      }
      else if (ctx.L2TPV3() != null) {
         return InterfaceType.L2TPV3;
      }
      else if (ctx.LOOPBACK() != null) {
         return InterfaceType.LOOPBACK;
      }
      else if (ctx.OPENVPN() != null) {
         return InterfaceType.OPENVPN;
      }
      else if (ctx.PSEUDO_ETHERNET() != null) {
         return InterfaceType.PSEUDO_ETHERNET;
      }
      else if (ctx.TUNNEL() != null) {
         return InterfaceType.TUNNEL;
      }
      else if (ctx.VTI() != null) {
         return InterfaceType.VTI;
      }
      else if (ctx.VXLAN() != null) {
         return InterfaceType.VXLAN;
      }
      else if (ctx.WIRELESS() != null) {
         return InterfaceType.WIRELESS;
      }
      else if (ctx.WIRELESSMODEM() != null) {
         return InterfaceType.WIRELESSMODEM;
      }
      else {
         throw new BatfishException(
               "Unsupported interface type: " + ctx.getText());
      }
   }

   private BgpProcess _bgpProcess;

   private VyosConfiguration _configuration;

   private BgpNeighbor _currentBgpNeighbor;

   private EspGroup _currentEspGroup;

   private EspProposal _currentEspProposal;

   private IkeGroup _currentIkeGroup;

   private IkeProposal _currentIkeProposal;

   private Interface _currentInterface;

   private IpsecPeer _currentIpsecPeer;

   private PrefixList _currentPrefixList;

   private PrefixListRule _currentPrefixListRule;

   private RouteMap _currentRouteMap;

   private RouteMapRule _currentRouteMapRule;

   private Prefix _currentStaticRoutePrefix;

   private final FlatVyosCombinedParser _parser;

   private final String _text;

   private final Set<String> _unimplementedFeatures;

   private VyosConfiguration _vendorConfiguration;

   private final Warnings _w;

   public FlatVyosControlPlaneExtractor(String text,
         FlatVyosCombinedParser parser, Warnings warnings) {
      _text = text;
      _parser = parser;
      _unimplementedFeatures = new TreeSet<>();
      _w = warnings;
   }

   @Override
   public void enterBt_neighbor(Bt_neighborContext ctx) {
      Ip neighborIp = new Ip(ctx.IP_ADDRESS().getText());
      _currentBgpNeighbor = _bgpProcess.getNeighbors().get(neighborIp);
      if (_currentBgpNeighbor == null) {
         _currentBgpNeighbor = new BgpNeighbor(neighborIp);
         _bgpProcess.getNeighbors().put(neighborIp, _currentBgpNeighbor);
      }
   }

   @Override
   public void enterEspt_proposal(Espt_proposalContext ctx) {
      int num = toInteger(ctx.num);
      _currentEspProposal = _currentEspGroup.getProposals().get(num);
      if (_currentEspProposal == null) {
         _currentEspProposal = new EspProposal(num);
         _currentEspGroup.getProposals().put(num, _currentEspProposal);
      }
   }

   @Override
   public void enterFlat_vyos_configuration(
         Flat_vyos_configurationContext ctx) {
      _vendorConfiguration = new VyosConfiguration();
      _configuration = _vendorConfiguration;
   }

   @Override
   public void enterIket_proposal(Iket_proposalContext ctx) {
      int num = toInteger(ctx.num);
      _currentIkeProposal = _currentIkeGroup.getProposals().get(num);
      if (_currentIkeProposal == null) {
         _currentIkeProposal = new IkeProposal(num);
         _currentIkeGroup.getProposals().put(num, _currentIkeProposal);
      }
   }

   @Override
   public void enterIvt_esp_group(Ivt_esp_groupContext ctx) {
      String name = ctx.name.getText();
      _currentEspGroup = _configuration.getEspGroups().get(name);
      if (_currentEspGroup == null) {
         _currentEspGroup = new EspGroup(name);
         _configuration.getEspGroups().put(name, _currentEspGroup);
      }
   }

   @Override
   public void enterIvt_ike_group(Ivt_ike_groupContext ctx) {
      String name = ctx.name.getText();
      _currentIkeGroup = _configuration.getIkeGroups().get(name);
      if (_currentIkeGroup == null) {
         _currentIkeGroup = new IkeGroup(name);
         _configuration.getIkeGroups().put(name, _currentIkeGroup);
      }
   }

   @Override
   public void enterIvt_site_to_site(Ivt_site_to_siteContext ctx) {
      Ip peerAddress = new Ip(ctx.peer.getText());
      _currentIpsecPeer = _configuration.getIpsecPeers().get(peerAddress);
      if (_currentIpsecPeer == null) {
         _currentIpsecPeer = new IpsecPeer(peerAddress);
         _configuration.getIpsecPeers().put(peerAddress, _currentIpsecPeer);
      }
   }

   @Override
   public void enterPlt_rule(Plt_ruleContext ctx) {
      int num = toInteger(ctx.num);
      _currentPrefixListRule = _currentPrefixList.getRules().get(num);
      if (_currentPrefixListRule == null) {
         _currentPrefixListRule = new PrefixListRule(num);
         _currentPrefixList.getRules().put(num, _currentPrefixListRule);
      }
   }

   @Override
   public void enterPt_prefix_list(Pt_prefix_listContext ctx) {
      String name = ctx.name.getText();
      _currentPrefixList = _configuration.getPrefixLists().get(name);
      if (_currentPrefixList == null) {
         _currentPrefixList = new PrefixList(name);
         _configuration.getPrefixLists().put(name, _currentPrefixList);
      }
   }

   @Override
   public void enterPt_route_map(Pt_route_mapContext ctx) {
      String name = ctx.name.getText();
      _currentRouteMap = _configuration.getRouteMaps().get(name);
      if (_currentRouteMap == null) {
         _currentRouteMap = new RouteMap(name);
         _configuration.getRouteMaps().put(name, _currentRouteMap);
      }
   }

   @Override
   public void enterRmt_rule(Rmt_ruleContext ctx) {
      int num = toInteger(ctx.num);
      _currentRouteMapRule = _currentRouteMap.getRules().get(num);
      if (_currentRouteMapRule == null) {
         _currentRouteMapRule = new RouteMapRule(num);
         _currentRouteMap.getRules().put(num, _currentRouteMapRule);
      }
   }

   @Override
   public void enterS_interfaces(S_interfacesContext ctx) {
      String name = ctx.name.getText();
      _currentInterface = _configuration.getInterfaces().get(name);
      if (_currentInterface == null) {
         _currentInterface = new Interface(name);
         _configuration.getInterfaces().put(name, _currentInterface);
         InterfaceType type = toInterfaceType(ctx.interface_type());
         double bandwidth = Interface.getDefaultBandwidth(type);
         _currentInterface.setBandwidth(bandwidth);
         _currentInterface.setType(type);
      }
   }

   @Override
   public void enterS_protocols_bgp(S_protocols_bgpContext ctx) {
      int as = toInteger(ctx.asnum);
      if (_bgpProcess == null) {
         _bgpProcess = new BgpProcess(as);
         _configuration.setBgpProcess(_bgpProcess);
      }
      else {
         if (_bgpProcess.getLocalAs() != as) {
            throw new BatfishException(
                  "Do not support multiple BGP processes at this time");
         }
      }
   }

   @Override
   public void enterStatict_route(Statict_routeContext ctx) {
      Prefix prefix = new Prefix(ctx.IP_PREFIX().getText());
      _currentStaticRoutePrefix = prefix;
   }

   @Override
   public void exitBnt_nexthop_self(Bnt_nexthop_selfContext ctx) {
      _currentBgpNeighbor.setNextHopSelf(true);
   }

   @Override
   public void exitBnt_remote_as(Bnt_remote_asContext ctx) {
      int remoteAs = toInteger(ctx.asnum);
      _currentBgpNeighbor.setRemoteAs(remoteAs);
   }

   @Override
   public void exitBnt_route_map_export(Bnt_route_map_exportContext ctx) {
      String name = ctx.name.getText();
      _currentBgpNeighbor.setExportRouteMap(name);
   }

   @Override
   public void exitBnt_route_map_import(Bnt_route_map_importContext ctx) {
      String name = ctx.name.getText();
      _currentBgpNeighbor.setImportRouteMap(name);
   }

   @Override
   public void exitBt_neighbor(Bt_neighborContext ctx) {
      _currentBgpNeighbor = null;
   }

   @Override
   public void exitEsppt_encryption(Esppt_encryptionContext ctx) {
      if (ctx.AES128() != null) {
         _currentEspProposal
               .setEncryptionAlgorithm(EncryptionAlgorithm.AES_128_CBC);
      }
      else if (ctx.AES256() != null) {
         _currentEspProposal
               .setEncryptionAlgorithm(EncryptionAlgorithm.AES_256_CBC);
      }
      else if (ctx.THREEDES() != null) {
         _currentEspProposal
               .setEncryptionAlgorithm(EncryptionAlgorithm.THREEDES_CBC);
      }
      else {
         throw new BatfishException("Invalid encryption algorithm");
      }
   }

   @Override
   public void exitEsppt_hash(Esppt_hashContext ctx) {
      HashAlgorithm hashAlgorithm = toHashAlgorithm(ctx.hash_algorithm());
      _currentEspProposal.setHashAlgorithm(hashAlgorithm);
   }

   @Override
   public void exitEspt_compression(Espt_compressionContext ctx) {
      if (ctx.DISABLE() != null) {
         _currentEspGroup.setCompression(false);
      }
      else if (ctx.ENABLE() != null) {
         _currentEspGroup.setCompression(true);
      }
   }

   @Override
   public void exitEspt_lifetime(Espt_lifetimeContext ctx) {
      int lifetimeSeconds = toInteger(ctx.seconds);
      _currentEspGroup.setLifetimeSeconds(lifetimeSeconds);
   }

   @Override
   public void exitEspt_pfs(Espt_pfsContext ctx) {
      if (ctx.ENABLE() != null) {
         _currentEspGroup.setPfsSource(PfsSource.IKE_GROUP);
      }
      else if (ctx.DISABLE() != null) {
         _currentEspGroup.setPfsSource(PfsSource.DISABLED);
      }
      else {
         _currentEspGroup.setPfsSource(PfsSource.ESP_GROUP);
         if (ctx.DH_GROUP2() != null) {
            _currentEspGroup.setPfsDhGroup(DiffieHellmanGroup.GROUP2);
         }
         else if (ctx.DH_GROUP5() != null) {
            _currentEspGroup.setPfsDhGroup(DiffieHellmanGroup.GROUP5);
         }
         else if (ctx.DH_GROUP14() != null) {
            _currentEspGroup.setPfsDhGroup(DiffieHellmanGroup.GROUP14);
         }
         else if (ctx.DH_GROUP15() != null) {
            _currentEspGroup.setPfsDhGroup(DiffieHellmanGroup.GROUP15);
         }
         else if (ctx.DH_GROUP16() != null) {
            _currentEspGroup.setPfsDhGroup(DiffieHellmanGroup.GROUP16);
         }
         else if (ctx.DH_GROUP17() != null) {
            _currentEspGroup.setPfsDhGroup(DiffieHellmanGroup.GROUP17);
         }
         else if (ctx.DH_GROUP18() != null) {
            _currentEspGroup.setPfsDhGroup(DiffieHellmanGroup.GROUP18);
         }
         else if (ctx.DH_GROUP19() != null) {
            _currentEspGroup.setPfsDhGroup(DiffieHellmanGroup.GROUP19);
         }
         else if (ctx.DH_GROUP20() != null) {
            _currentEspGroup.setPfsDhGroup(DiffieHellmanGroup.GROUP20);
         }
         else if (ctx.DH_GROUP21() != null) {
            _currentEspGroup.setPfsDhGroup(DiffieHellmanGroup.GROUP21);
         }
         else if (ctx.DH_GROUP22() != null) {
            _currentEspGroup.setPfsDhGroup(DiffieHellmanGroup.GROUP22);
         }
         else if (ctx.DH_GROUP23() != null) {
            _currentEspGroup.setPfsDhGroup(DiffieHellmanGroup.GROUP23);
         }
         else if (ctx.DH_GROUP24() != null) {
            _currentEspGroup.setPfsDhGroup(DiffieHellmanGroup.GROUP24);
         }
         else if (ctx.DH_GROUP25() != null) {
            _currentEspGroup.setPfsDhGroup(DiffieHellmanGroup.GROUP25);
         }
         else if (ctx.DH_GROUP26() != null) {
            _currentEspGroup.setPfsDhGroup(DiffieHellmanGroup.GROUP26);
         }
         else {
            throw new BatfishException("Invalid Diffie-Hellman group");
         }
      }
   }

   @Override
   public void exitEspt_proposal(Espt_proposalContext ctx) {
      _currentEspProposal = null;
   }

   @Override
   public void exitIkept_dh_group(Ikept_dh_groupContext ctx) {
      int num = toInteger(ctx.num);
      DiffieHellmanGroup dhGroup = DiffieHellmanGroup.fromGroupNumber(num);
      _currentIkeProposal.setDhGroup(dhGroup);
   }

   @Override
   public void exitIkept_encryption(Ikept_encryptionContext ctx) {
      if (ctx.AES128() != null) {
         _currentIkeProposal
               .setEncryptionAlgorithm(EncryptionAlgorithm.AES_128_CBC);
      }
      else if (ctx.AES256() != null) {
         _currentIkeProposal
               .setEncryptionAlgorithm(EncryptionAlgorithm.AES_256_CBC);
      }
      else if (ctx.THREEDES() != null) {
         _currentIkeProposal
               .setEncryptionAlgorithm(EncryptionAlgorithm.THREEDES_CBC);
      }
      else {
         throw new BatfishException("Invalid encryption algorithm");
      }
   }

   @Override
   public void exitIkept_hash(Ikept_hashContext ctx) {
      HashAlgorithm hashAlgorithm = toHashAlgorithm(ctx.hash_algorithm());
      _currentIkeProposal.setHashAlgorithm(hashAlgorithm);
   }

   @Override
   public void exitIket_key_exchange(Iket_key_exchangeContext ctx) {
      if (ctx.IKEV1() != null) {
         // ..great?
      }
      else if (ctx.IKEV2() != null) {
         // TODO: ??
         throw new BatfishException("Not currently supported");
      }
   }

   @Override
   public void exitIket_lifetime(Iket_lifetimeContext ctx) {
      int lifetimeSeconds = toInteger(ctx.seconds);
      _currentIkeGroup.setLifetimeSeconds(lifetimeSeconds);
   }

   @Override
   public void exitIket_proposal(Iket_proposalContext ctx) {
      _currentIkeProposal = null;
   }

   @Override
   public void exitIt_address(It_addressContext ctx) {
      if (ctx.DHCP() != null) {
         todo(ctx, F_INTERFACES_ADDRESS_DHCP);
      }
      else if (ctx.IP_PREFIX() != null) {
         Prefix prefix = new Prefix(ctx.IP_PREFIX().getText());
         if (_currentInterface.getPrefix() == null) {
            _currentInterface.setPrefix(prefix);
         }
         _currentInterface.getAllPrefixes().add(prefix);
      }
   }

   @Override
   public void exitIt_description(It_descriptionContext ctx) {
      String description = ctx.description().DESCRIPTION_TEXT().getText();
      _currentInterface.setDescription(description);
   }

   @Override
   public void exitIvt_esp_group(Ivt_esp_groupContext ctx) {
      _currentEspGroup = null;
   }

   @Override
   public void exitIvt_ike_group(Ivt_ike_groupContext ctx) {
      _currentIkeGroup = null;
   }

   @Override
   public void exitIvt_ipsec_interfaces(Ivt_ipsec_interfacesContext ctx) {
      String ipsecInterface = ctx.name.getText();
      _configuration.getIpsecInterfaces().add(ipsecInterface);
   }

   @Override
   public void exitIvt_site_to_site(Ivt_site_to_siteContext ctx) {
      _currentIpsecPeer = null;
   }

   @Override
   public void exitPlrt_action(Plrt_actionContext ctx) {
      LineAction action = toAction(ctx.action);
      _currentPrefixListRule.setAction(action);
   }

   @Override
   public void exitPlrt_description(Plrt_descriptionContext ctx) {
      String description = ctx.description().DESCRIPTION_TEXT().getText();
      _currentPrefixListRule.setDescription(description);
   }

   @Override
   public void exitPlrt_ge(Plrt_geContext ctx) {
      int ge = toInteger(ctx.num);
      _currentPrefixListRule.setGe(ge);
   }

   @Override
   public void exitPlrt_le(Plrt_leContext ctx) {
      int le = toInteger(ctx.num);
      _currentPrefixListRule.setLe(le);
   }

   @Override
   public void exitPlrt_prefix(Plrt_prefixContext ctx) {
      Prefix prefix = new Prefix(ctx.prefix.getText());
      _currentPrefixListRule.setPrefix(prefix);
   }

   @Override
   public void exitPlt_description(Plt_descriptionContext ctx) {
      String description = ctx.description().DESCRIPTION_TEXT().getText();
      _currentPrefixList.setDescription(description);
   }

   @Override
   public void exitPlt_rule(Plt_ruleContext ctx) {
      _currentPrefixListRule = null;
   }

   @Override
   public void exitPt_prefix_list(Pt_prefix_listContext ctx) {
      _currentPrefixList = null;
   }

   @Override
   public void exitPt_route_map(Pt_route_mapContext ctx) {
      _currentRouteMap = null;
   }

   @Override
   public void exitRmmt_ip_address_prefix_list(
         Rmmt_ip_address_prefix_listContext ctx) {
      String name = ctx.name.getText();
      int statementLine = ctx.name.getStart().getLine();
      RouteMapMatch match = new RouteMapMatchPrefixList(name, statementLine);
      _currentRouteMapRule.getMatches().add(match);
   }

   @Override
   public void exitRmrt_action(Rmrt_actionContext ctx) {
      LineAction action = toAction(ctx.action);
      _currentRouteMapRule.setAction(action);
   }

   @Override
   public void exitRmrt_description(Rmrt_descriptionContext ctx) {
      String description = ctx.description().DESCRIPTION_TEXT().getText();
      _currentRouteMapRule.setDescription(description);
   }

   @Override
   public void exitRmt_rule(Rmt_ruleContext ctx) {
      _currentRouteMapRule = null;
   }

   @Override
   public void exitS_interfaces(S_interfacesContext ctx) {
      _currentInterface = null;
   }

   @Override
   public void exitS2sat_id(S2sat_idContext ctx) {
      String authenticationId = ctx.name.getText();
      _currentIpsecPeer.setAuthenticationId(authenticationId);
   }

   @Override
   public void exitS2sat_mode(S2sat_modeContext ctx) {
      if (ctx.PRE_SHARED_SECRET() != null) {
         _currentIpsecPeer
               .setAuthenticationMode(IkeAuthenticationMethod.PRE_SHARED_KEYS);
      }
      else if (ctx.RSA() != null) {
         _currentIpsecPeer
               .setAuthenticationMode(IkeAuthenticationMethod.RSA_SIGNATURES);
      }
      else if (ctx.X509() != null) {
         _currentIpsecPeer.setAuthenticationMode(IkeAuthenticationMethod.X509);
      }
   }

   @Override
   public void exitS2sat_pre_shared_secret(S2sat_pre_shared_secretContext ctx) {
      String secret = ctx.secret.getText();
      String saltedSecret = secret + SALT;
      String secretHash = CommonUtil.sha256Digest(saltedSecret);
      _currentIpsecPeer.setAuthenticationPreSharedSecretHash(secretHash);
   }

   @Override
   public void exitS2sat_remote_id(S2sat_remote_idContext ctx) {
      String authenticationRemoteId = ctx.name.getText();
      _currentIpsecPeer.setAuthenticationRemoteId(authenticationRemoteId);
   }

   @Override
   public void exitS2st_connection_type(S2st_connection_typeContext ctx) {
      if (ctx.INITIATE() != null) {
         _currentIpsecPeer.setInitiate(true);
      }
      else if (ctx.RESPOND() != null) {
         _currentIpsecPeer.setInitiate(false);
      }
      else {
         throw new BatfishException("Invalid connection type");
      }
   }

   @Override
   public void exitS2st_description(S2st_descriptionContext ctx) {
      String description = ctx.description().DESCRIPTION_TEXT().getText();
      _currentIpsecPeer.setDescription(description);
   }

   @Override
   public void exitS2st_ike_group(S2st_ike_groupContext ctx) {
      String ikeGroup = ctx.name.getText();
      _currentIpsecPeer.setIkeGroup(ikeGroup);
   }

   @Override
   public void exitS2st_local_address(S2st_local_addressContext ctx) {
      Ip localAddress = new Ip(ctx.ip.getText());
      _currentIpsecPeer.setLocalAddress(localAddress);
   }

   @Override
   public void exitS2svt_bind(S2svt_bindContext ctx) {
      String bindInterface = ctx.name.getText();
      _currentIpsecPeer.setBindInterface(bindInterface);
   }

   @Override
   public void exitS2svt_esp_group(S2svt_esp_groupContext ctx) {
      String espGroup = ctx.name.getText();
      _currentIpsecPeer.setEspGroup(espGroup);
   }

   @Override
   public void exitSrt_next_hop(Srt_next_hopContext ctx) {
      Ip nextHopIp = new Ip(ctx.nexthop.getText());
      int distance = toInteger(ctx.distance);
      StaticNextHopRoute staticRoute = new StaticNextHopRoute(
            _currentStaticRoutePrefix, nextHopIp, distance);
      _configuration.getStaticNextHopRoutes().add(staticRoute);
   }

   @Override
   public void exitSt_host_name(St_host_nameContext ctx) {
      String hostname = ctx.name.getText();
      _configuration.setHostname(hostname);
   }

   @Override
   public void exitStatict_route(Statict_routeContext ctx) {
      _currentStaticRoutePrefix = null;
   }

   @Override
   public Set<String> getUnimplementedFeatures() {
      return _unimplementedFeatures;
   }

   @Override
   public VendorConfiguration getVendorConfiguration() {
      return _vendorConfiguration;
   }

   @Override
   public void processParseTree(ParserRuleContext tree) {
      ParseTreeWalker walker = new ParseTreeWalker();
      walker.walk(this, tree);
   }

   private void todo(ParserRuleContext ctx, String feature) {
      _w.todo(ctx, feature, _parser, _text);
      _unimplementedFeatures.add("Vyos: " + feature);
   }

}