Move the code to guess the traffic type based on the packet contents

into Wiretap, so that if you read a frame from Wiretap you have what
traffic type information could be gleaned from the information in the
capture file, and can write the frame out to a capture file where the
file contains some or all of that information without having to
determine it outside of Wiretap.

svn path=/trunk/; revision=5314

1 files changed, 116 insertions, 0 deletions

diff --git a/wiretap/atm.c b/wiretap/atm.c
new file mode 100644
index 0000000000..d4bace9a1a
--- /dev/null
+++ b/wiretap/atm.c
@@ -0,0 +1,116 @@
+/* atm.c
+ *
+ * $Id: atm.c,v 1.1 2002/04/30 18:58:15 guy Exp $
+ *
+ * Wiretap Library
+ * Copyright (c) 1998 by Gilbert Ramirez <gram@alumni.rice.edu>
+ * 
+ * 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+#include "wtap-int.h"
+#include "atm.h"
+
+/*
+ * Routines to use with ATM capture file types that don't include information
+ * about the *type* of ATM traffic (or, at least, where we haven't found
+ * that information).
+ *
+ * We assume the traffic is AAL5, unless it's VPI 0/VCI 5, in which case
+ * we assume it's the signalling AAL.
+ */
+
+void
+atm_guess_traffic_type(const guint8 *pd, guint32 len,
+    guint16 vpi, guint16 vci, union wtap_pseudo_header *pseudo_header)
+{
+	/*
+	 * Start out assuming nothing other than that it's AAL5.
+	 */
+	pseudo_header->atm.aal = AAL_5;
+	pseudo_header->atm.type = TRAF_UNKNOWN;
+	pseudo_header->atm.subtype = TRAF_ST_UNKNOWN;
+
+	if (vpi == 0) {
+		/*
+		 * Traffic on some PVCs with a VPI of 0 and certain
+		 * VCIs is of particular types.
+		 */
+		switch (vci) {
+
+		case 5:
+			/*
+			 * Signalling AAL.
+			 */
+			pseudo_header->atm.aal = AAL_SIGNALLING;
+			return;
+
+		case 16:
+			/*
+			 * ILMI.
+			 */
+			pseudo_header->atm.type = TRAF_ILMI;
+			return;
+		}
+	}
+
+	/*
+	 * OK, we can't tell what it is based on the VPI/VCI; try
+	 * guessing based on the contents, if we have enough data
+	 * to guess.
+	 */
+	if (len >= 3) {
+		if (pd[0] == 0xaa && pd[1] == 0xaa && pd[2] == 0x03) {
+			/*
+			 * Looks like a SNAP header; assume it's LLC
+			 * multiplexed RFC 1483 traffic.
+			 */
+			pseudo_header->atm.type = TRAF_LLCMX;
+		} else {
+			/*
+			 * Assume it's LANE.
+			 */
+			pseudo_header->atm.type = TRAF_LANE;
+			atm_guess_lane_type(pd, len, pseudo_header);
+		}
+	}
+}
+
+void
+atm_guess_lane_type(const guint8 *pd, guint32 len,
+    union wtap_pseudo_header *pseudo_header)
+{
+	if (len >= 2) {
+		if (pd[0] == 0xff && pd[1] == 0x00) {
+			/*
+			 * Looks like LE Control traffic.
+			 */
+			pseudo_header->atm.subtype = TRAF_ST_LANE_LE_CTRL;
+		} else {
+			/*
+			 * XXX - Ethernet, or Token Ring?
+			 * Assume Ethernet for now; if we see earlier
+			 * LANE traffic, we may be able to figure out
+			 * the traffic type from that, but there may
+			 * still be situations where the user has to
+			 * tell us.
+			 */
+			pseudo_header->atm.subtype = TRAF_ST_LANE_802_3;
+		}
+	}
+}