ips/drop-log: fix crash on logging drops

When logging drops for fragmented UDP packets, triggered by detection
in the reassembled packet, a missing check could lead to access of the
packets UDP header pointer when it was NULL.

src/log-droplog.c

@@ -224,6 +224,7 @@ static int LogDropLogNetFilter (ThreadVars *tv, const Packet *p, void *data)
 
     switch (proto) {
         case IPPROTO_TCP:
+            if (PKT_IS_TCP(p)) {
                 fprintf(dlt->file_ctx->fp, " SPT=%"PRIu16" DPT=%"PRIu16" "
                         "SEQ=%"PRIu32" ACK=%"PRIu32" WINDOW=%"PRIu32"",
                         GET_TCP_SRC_PORT(p), GET_TCP_DST_PORT(p), TCP_GET_SEQ(p),
@@ -236,11 +237,14 @@ static int LogDropLogNetFilter (ThreadVars *tv, const Packet *p, void *data)
                 fprintf(dlt->file_ctx->fp, TCP_ISSET_FLAG_FIN(p) ? " FIN" : "");
                 fprintf(dlt->file_ctx->fp, " RES=0x%02"PRIu8" URGP=%"PRIu16"",
                         TCP_GET_RAW_X2(p->tcph), TCP_GET_URG_POINTER(p));
+            }
             break;
         case IPPROTO_UDP:
+            if (PKT_IS_UDP(p)) {
                 fprintf(dlt->file_ctx->fp, " SPT=%"PRIu16" DPT=%"PRIu16""
                         " LEN=%"PRIu16"", UDP_GET_SRC_PORT(p),
                         UDP_GET_DST_PORT(p), UDP_GET_LEN(p));
+            }
             break;
         case IPPROTO_ICMP:
             if (PKT_IS_ICMPV4(p)) {

src/output-json-drop.c

@@ -114,6 +114,7 @@ static int DropLogJSON (JsonDropLogThread *aft, const Packet *p)
     }
     switch (proto) {
         case IPPROTO_TCP:
+            if (PKT_IS_TCP(p)) {
                 json_object_set_new(djs, "tcpseq", json_integer(TCP_GET_SEQ(p)));
                 json_object_set_new(djs, "tcpack", json_integer(TCP_GET_ACK(p)));
                 json_object_set_new(djs, "tcpwin", json_integer(TCP_GET_WINDOW(p)));
@@ -125,9 +126,12 @@ static int DropLogJSON (JsonDropLogThread *aft, const Packet *p)
                 json_object_set_new(djs, "fin", TCP_ISSET_FLAG_FIN(p) ? json_true() : json_false());
                 json_object_set_new(djs, "tcpres", json_integer(TCP_GET_RAW_X2(p->tcph)));
                 json_object_set_new(djs, "tcpurgp", json_integer(TCP_GET_URG_POINTER(p)));
+            }
             break;
         case IPPROTO_UDP:
+            if (PKT_IS_UDP(p)) {
                 json_object_set_new(djs, "udplen", json_integer(UDP_GET_LEN(p)));
+            }
             break;
         case IPPROTO_ICMP:
             if (PKT_IS_ICMPV4(p)) {