decode/gre: decode arp packets

src/decode-gre.c

@@ -274,6 +274,16 @@ int DecodeGRE(ThreadVars *tv, DecodeThreadVars *dtv, Packet *p, const uint8_t *p
             break;
         }
 
+        case ETHERNET_TYPE_ARP: {
+            Packet *tp = PacketTunnelPktSetup(
+                    tv, dtv, p, pkt + header_len, len - header_len, DECODE_TUNNEL_ARP);
+            if (tp != NULL) {
+                PKT_SET_SRC(tp, PKT_SRC_DECODER_GRE);
+                PacketEnqueueNoLock(&tv->decode_pq, tp);
+            }
+            break;
+        }
+
         default:
             return TM_ECODE_OK;
     }

src/decode.c

@@ -61,6 +61,7 @@
 #include "decode-geneve.h"
 #include "decode-erspan.h"
 #include "decode-teredo.h"
+#include "decode-arp.h"
 
 #include "defrag-hash.h"
 
@@ -177,6 +178,8 @@ static int DecodeTunnel(ThreadVars *tv, DecodeThreadVars *dtv, Packet *p, const
             return DecodeERSPANTypeI(tv, dtv, p, pkt, len);
         case DECODE_TUNNEL_NSH:
             return DecodeNSH(tv, dtv, p, pkt, len);
+        case DECODE_TUNNEL_ARP:
+            return DecodeARP(tv, dtv, p, pkt, len);
         default:
             SCLogDebug("FIXME: DecodeTunnel: protocol %" PRIu32 " not supported.", proto);
             break;

src/decode.h

@@ -1091,6 +1091,7 @@ enum DecodeTunnelProto {
     DECODE_TUNNEL_IPV6_TEREDO, /**< separate protocol for stricter error handling */
     DECODE_TUNNEL_PPP,
     DECODE_TUNNEL_NSH,
+    DECODE_TUNNEL_ARP,
     DECODE_TUNNEL_UNSET
 };