FRR: Parse IPv6 BGP neighbors (#6587)

projects/batfish/src/main/antlr4/org/batfish/grammar/cumulus_frr/CumulusFrrLexer.g4

@@ -424,6 +424,16 @@ IP_PREFIX
   F_IpPrefix
 ;
 
+IPV6_ADDRESS
+:
+  F_Ipv6Address
+;
+
+IPV6_PREFIX
+:
+  F_Ipv6Prefix
+;
+
 L2VPN
 :
   'l2vpn'
@@ -846,6 +856,145 @@ F_Digit
   [0-9]
 ;
 
+fragment
+F_HexDigit
+:
+  [0-9A-Fa-f]
+;
+
+fragment
+F_HexWord
+:
+  F_HexDigit F_HexDigit? F_HexDigit? F_HexDigit?
+;
+
+fragment
+F_HexWord2
+:
+  F_HexWord ':' F_HexWord
+;
+
+fragment
+F_HexWord3
+:
+  F_HexWord2 ':' F_HexWord
+;
+
+fragment
+F_HexWord4
+:
+  F_HexWord3 ':' F_HexWord
+;
+
+fragment
+F_HexWord5
+:
+  F_HexWord4 ':' F_HexWord
+;
+
+fragment
+F_HexWord6
+:
+  F_HexWord5 ':' F_HexWord
+;
+
+fragment
+F_HexWord7
+:
+  F_HexWord6 ':' F_HexWord
+;
+
+fragment
+F_HexWord8
+:
+  F_HexWord6 ':' F_HexWordFinal2
+;
+
+fragment
+F_HexWordFinal2
+:
+  F_HexWord2
+  | F_IpAddress
+;
+
+fragment
+F_HexWordFinal3
+:
+  F_HexWord ':' F_HexWordFinal2
+;
+
+fragment
+F_HexWordFinal4
+:
+  F_HexWord ':' F_HexWordFinal3
+;
+
+fragment
+F_HexWordFinal5
+:
+  F_HexWord ':' F_HexWordFinal4
+;
+
+fragment
+F_HexWordFinal6
+:
+  F_HexWord ':' F_HexWordFinal5
+;
+
+fragment
+F_HexWordFinal7
+:
+  F_HexWord ':' F_HexWordFinal6
+;
+
+fragment
+F_HexWordLE1
+:
+  F_HexWord?
+;
+
+fragment
+F_HexWordLE2
+:
+  F_HexWordLE1
+  | F_HexWordFinal2
+;
+
+fragment
+F_HexWordLE3
+:
+  F_HexWordLE2
+  | F_HexWordFinal3
+;
+
+fragment
+F_HexWordLE4
+:
+  F_HexWordLE3
+  | F_HexWordFinal4
+;
+
+fragment
+F_HexWordLE5
+:
+  F_HexWordLE4
+  | F_HexWordFinal5
+;
+
+fragment
+F_HexWordLE6
+:
+  F_HexWordLE5
+  | F_HexWordFinal6
+;
+
+fragment
+F_HexWordLE7
+:
+  F_HexWordLE6
+  | F_HexWordFinal7
+;
+
 fragment
 F_IpAddress
 :
@@ -866,6 +1015,35 @@ F_IpPrefixLength
   | [3] [012]
 ;
 
+fragment
+F_Ipv6Address
+:
+  '::' F_HexWordLE7
+  | F_HexWord '::' F_HexWordLE6
+  | F_HexWord2 '::' F_HexWordLE5
+  | F_HexWord3 '::' F_HexWordLE4
+  | F_HexWord4 '::' F_HexWordLE3
+  | F_HexWord5 '::' F_HexWordLE2
+  | F_HexWord6 '::' F_HexWordLE1
+  | F_HexWord7 '::'
+  | F_HexWord8
+;
+
+fragment
+F_Ipv6Prefix
+:
+  F_Ipv6Address '/' F_Ipv6PrefixLength
+;
+
+fragment
+F_Ipv6PrefixLength
+:
+  F_Digit
+  | F_PositiveDigit F_Digit
+  | '1' [01] F_Digit
+  | '12' [0-8]
+;
+
 fragment
 F_SubnetMask
 :
@@ -1095,6 +1273,11 @@ M_Neighbor_IP_Address
   F_IpAddress -> type(IP_ADDRESS) , popMode
 ;
 
+M_Neighbor_IPV6_Address
+:
+  F_Ipv6Address -> type(IPV6_ADDRESS) , popMode
+;
+
 M_Neighbor_Word
 :
   F_Word -> type(WORD) , popMode

projects/batfish/src/main/antlr4/org/batfish/grammar/cumulus_frr/CumulusFrrParser.g4

@@ -25,6 +25,7 @@ statement
   | s_frr
   | s_hostname
   | s_ip
+  | s_ipv6
   | s_line
   | s_log
   | s_no
@@ -102,6 +103,11 @@ s_ip
   )
 ;
 
+s_ipv6
+:
+   IPV6 null_rest_of_line
+;
+
 ip_route
 :
   ROUTE network = prefix (next_hop_ip = ip_address | next_hop_interface = word) (distance = uint8)?

projects/batfish/src/main/antlr4/org/batfish/grammar/cumulus_frr/CumulusFrr_bgp.g4

@@ -105,7 +105,7 @@ sbb_cluster_id
 
 sb_neighbor
 :
-  NEIGHBOR (sbn_ip | sbn_name) NEWLINE
+  NEIGHBOR (sbn_ip | sbn_ip6 | sbn_name) NEWLINE
 ;
 
 sb_address_family
@@ -117,6 +117,7 @@ sb_address_family
 sbaf
 :
     sbaf_ipv4_unicast
+  | sbaf_ipv6_unicast
   | sbaf_l2vpn_evpn
 ;
 
@@ -134,6 +135,22 @@ sbaf_ipv4_unicast
   )*
 ;
 
+sbaf_ipv6_unicast
+:
+  IPV6 UNICAST NEWLINE
+  sbafi6_null_tail*
+;
+
+sbafi6_null_tail
+:
+  (
+     // there are likely others but haven't seen examples yet, so leaving for later
+     NEIGHBOR
+     | REDISTRIBUTE
+  ) null_rest_of_line
+;
+
+
 sbaf_l2vpn_evpn
 :
   L2VPN EVPN NEWLINE
@@ -209,6 +226,11 @@ sbn_ip
   ip = IP_ADDRESS sbn_property
 ;
 
+sbn_ip6
+:
+   ip6 = IPV6_ADDRESS sbn_property
+;
+
 sbn_name
 :
   name = word

projects/batfish/src/main/antlr4/org/batfish/grammar/cumulus_frr/CumulusFrr_routemap.g4

@@ -51,6 +51,7 @@ rm_match
     | rmm_community
     | rmm_interface
     | rmm_ip
+    | rmm_ipv6
     | rmm_tag
   )
 ;
@@ -101,6 +102,11 @@ rmm_ip
   IP rmmip_address
 ;
 
+rmm_ipv6
+:
+  IPV6 null_rest_of_line
+;
+
 rmm_tag
 :
   TAG tag = uint32 NEWLINE

projects/batfish/src/main/java/org/batfish/grammar/cumulus_frr/CumulusFrrConfigurationBuilder.java

@@ -45,6 +45,7 @@
 import org.batfish.common.Warnings.ParseWarning;
 import org.batfish.datamodel.ConcreteInterfaceAddress;
 import org.batfish.datamodel.Ip;
+import org.batfish.datamodel.Ip6;
 import org.batfish.datamodel.LineAction;
 import org.batfish.datamodel.Prefix;
 import org.batfish.datamodel.SubRange;
@@ -125,6 +126,7 @@
 import org.batfish.grammar.cumulus_frr.CumulusFrrParser.Sbb_router_idContext;
 import org.batfish.grammar.cumulus_frr.CumulusFrrParser.Sbbb_aspath_multipath_relaxContext;
 import org.batfish.grammar.cumulus_frr.CumulusFrrParser.Sbn_interfaceContext;
+import org.batfish.grammar.cumulus_frr.CumulusFrrParser.Sbn_ip6Context;
 import org.batfish.grammar.cumulus_frr.CumulusFrrParser.Sbn_ipContext;
 import org.batfish.grammar.cumulus_frr.CumulusFrrParser.Sbn_nameContext;
 import org.batfish.grammar.cumulus_frr.CumulusFrrParser.Sbn_peer_group_declContext;
@@ -149,6 +151,7 @@
 import org.batfish.representation.cumulus.BgpInterfaceNeighbor;
 import org.batfish.representation.cumulus.BgpIpNeighbor;
 import org.batfish.representation.cumulus.BgpIpv4UnicastAddressFamily;
+import org.batfish.representation.cumulus.BgpIpv6Neighbor;
 import org.batfish.representation.cumulus.BgpL2VpnEvpnIpv4Unicast;
 import org.batfish.representation.cumulus.BgpL2vpnEvpnAddressFamily;
 import org.batfish.representation.cumulus.BgpNeighbor;
@@ -871,11 +874,20 @@ public void exitSbb_max_med_administrative(Sbb_max_med_administrativeContext ctx
 
   @Override
   public void enterSbn_ip(Sbn_ipContext ctx) {
-    String name = ctx.ip.getText();
     _currentBgpNeighbor =
         _currentBgpVrf
             .getNeighbors()
-            .computeIfAbsent(name, (ipStr) -> new BgpIpNeighbor(ipStr, Ip.parse(ipStr)));
+            .computeIfAbsent(
+                ctx.ip.getText(), (ipStr) -> new BgpIpNeighbor(ipStr, Ip.parse(ipStr)));
+  }
+
+  @Override
+  public void enterSbn_ip6(Sbn_ip6Context ctx) {
+    _currentBgpNeighbor =
+        _currentBgpVrf
+            .getNeighbors()
+            .computeIfAbsent(
+                ctx.ip6.getText(), (ipStr) -> new BgpIpv6Neighbor(ipStr, Ip6.parse(ipStr)));
   }
 
   @Override

projects/batfish/src/main/java/org/batfish/representation/cumulus/BgpIpv6Neighbor.java

@@ -0,0 +1,18 @@
+package org.batfish.representation.cumulus;
+
+import javax.annotation.Nonnull;
+import org.batfish.datamodel.Ip6;
+
+/** BGP neighbor identified by an IPv4 peer address */
+public class BgpIpv6Neighbor extends BgpNeighbor {
+  private final @Nonnull Ip6 _peerIp;
+
+  public BgpIpv6Neighbor(String name, Ip6 ip6) {
+    super(name);
+    _peerIp = ip6;
+  }
+
+  public @Nonnull Ip6 getPeerIp() {
+    return _peerIp;
+  }
+}

projects/batfish/src/main/java/org/batfish/representation/cumulus/CumulusConversions.java

@@ -502,7 +502,7 @@ static void addBgpNeighbor(
     } else if (neighbor instanceof BgpIpNeighbor) {
       BgpIpNeighbor ipNeighbor = (BgpIpNeighbor) neighbor;
       addIpv4BgpNeighbor(c, vsConfig, ipNeighbor, localAs, bgpVrf, viBgpProcess, w);
-    } else if (!(neighbor instanceof BgpPeerGroupNeighbor)) {
+    } else if (!(neighbor instanceof BgpPeerGroupNeighbor || neighbor instanceof BgpIpv6Neighbor)) {
       throw new IllegalArgumentException(
           "Unsupported BGP neighbor type: " + neighbor.getClass().getSimpleName());
     }