add a function to test if a packet is ndmp or not

svn path=/trunk/; revision=23007

2 files changed, 54 insertions, 8 deletions

diff --git a/epan/dissectors/packet-ndmp.c b/epan/dissectors/packet-ndmp.c
index f6175f5d48..fcbf8f3822 100644
--- a/epan/dissectors/packet-ndmp.c
+++ b/epan/dissectors/packet-ndmp.c
@@ -42,6 +42,7 @@
 #include <epan/conversation.h>
 #include <epan/emem.h>
 #include "packet-rpc.h"
+#include "packet-ndmp.h"
 #include "packet-tcp.h"
 #include "packet-scsi.h"
 #include "packet-frame.h"
@@ -3026,15 +3027,15 @@ get_ndmp_pdu_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offset)
   return len+4;
 }
 
-static int
-dissect_ndmp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+gboolean
+check_if_ndmp(tvbuff_t *tvb, packet_info *pinfo)
 {
 	guint len;
 	guint32 tmp;
 
 	/* verify that the tcp port is 10000, ndmp always runs on port 10000*/
 	if ((pinfo->srcport!=TCP_PORT_NDMP)&&(pinfo->destport!=TCP_PORT_NDMP)) {
-		return 0;
+		return FALSE;
 	}
 
 	/* check that the header looks sane */
@@ -3045,40 +3046,53 @@ dissect_ndmp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 	if(len>=4){
 		tmp=(tvb_get_ntohl(tvb, 0)&RPC_RM_FRAGLEN);
 		if( (tmp<24)||(tmp>1000000) ){
-			return 0;
+			return FALSE;
 		}
 	}
+
 	/* check the timestamp,  timestamps are valid if they
 	 * (arbitrary) lie between 1980-jan-1 and 2030-jan-1
 	 */
 	if(len>=12){
 		tmp=tvb_get_ntohl(tvb, 8);
 		if( (tmp<0x12ceec50)||(tmp>0x70dc1ed0) ){
-			return 0;
+			return FALSE;
 		}
 	}
+
 	/* check the type */
 	if(len>=16){
 		tmp=tvb_get_ntohl(tvb, 12);
 		if( tmp>1 ){
-			return 0;
+			return FALSE;
 		}
 	}
+
 	/* check message */
 	if(len>=20){
 		tmp=tvb_get_ntohl(tvb, 16);
 		if( (tmp>0xa09) || (tmp==0) ){
-			return 0;
+			return FALSE;
 		}
 	}
+
 	/* check error */
 	if(len>=28){
 		tmp=tvb_get_ntohl(tvb, 24);
 		if( (tmp>0x17) ){
-			return 0;
+			return FALSE;
 		}
 	}
 
+	return TRUE;
+}
+
+static int
+dissect_ndmp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+	if(!check_if_ndmp(tvb, pinfo)) {
+		return 0;
+	}
 
 	tcp_dissect_pdus(tvb, pinfo, tree, ndmp_desegment, 28,
 			 get_ndmp_pdu_len, dissect_ndmp_message);
diff --git a/epan/dissectors/packet-ndmp.h b/epan/dissectors/packet-ndmp.h
new file mode 100644
index 0000000000..e152820179
--- /dev/null
+++ b/epan/dissectors/packet-ndmp.h
@@ -0,0 +1,32 @@
+/* packet-ndmp.h
+ *
+ * $Id$
+ *
+ * (c) 2007 Ronnie Sahlberg
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#ifndef __PACKET_NDMP_H__
+#define __PACKET_NDMP_H__
+
+extern gboolean check_if_ndmp(tvbuff_t *tvb, packet_info *pinfo);
+
+#endif /* packet-ndmp.h */
+