Move show_exception() and show_reported_bounds_error() to

epan/show_exception.c, as it's used outside
epan/dissectors/packet-frame.c.  Update their callers to include
<epan/show_exception.h> to get their declaration.

Add a CATCH_NONFATAL_ERRORS macro that catches all exceptions that, if
there's more stuff in the packet to dissect after the dissector call
that threw the exception, doesn't mean you shouldn't go ahead and
dissect that stuff.  Use it in all those cases, including ones where
BoundsError was inappropriately being caught (you want those passed up
to the top level, so that the packet is reported as having been cut
short in the capture process).

Add a CATCH_BOUNDS_ERRORS macro that catches all exceptions that
correspond to running past the end of the data for a tvbuff; use it
rather than explicitly catching those exceptions individually, and
rather than just catching all exceptions (the only place that
DissectorError should be caught, for example, is at the top level, so
dissector bugs show up in the protocol tree).

Don't catch and then immediately rethrow exceptions without doing
anything else; just let the exceptions go up to the final catcher.

Use show_exception() to report non-fatal errors, rather than doing it
yourself.
 
If a dissector is called from Lua, catch all non-fatal errors and use
show_exception() to report them rather than catching only
ReportedBoundsError and adding a proto_malformed item.

Don't catch exceptions when constructing a trailer tvbuff in
packet-ieee8023.c - just construct it after the payload has been
dissected, and let whatever exceptions that throws be handled at the top
level.

Avoid some TRY/CATCH/ENDTRY cases by using checks such as
tvb_bytes_exist() before even looking in the tvbuff.

svn path=/trunk/; revision=47924

1 files changed, 12 insertions, 30 deletions

diff --git a/epan/dissectors/packet-ethertype.c b/epan/dissectors/packet-ethertype.c
index b3a8dea332..142a3c0fe2 100644
--- a/epan/dissectors/packet-ethertype.c
+++ b/epan/dissectors/packet-ethertype.c
@@ -30,17 +30,17 @@
 
 #include <glib.h>
 #include <epan/packet.h>
+#include <epan/etypes.h>
+#include <epan/ppptypes.h>
+#include <epan/show_exception.h>
 #include "packet-bpq.h"
 #include "packet-eth.h"
-#include "packet-frame.h"
 #include "packet-ip.h"
 #include "packet-ipv6.h"
 #include "packet-ipx.h"
 #include "packet-vlan.h"
 #include "packet-ieee8021ah.h"
 #include "packet-vines.h"
-#include <epan/etypes.h>
-#include <epan/ppptypes.h>
 
 static dissector_table_t ethertype_dissector_table;
 
@@ -276,34 +276,16 @@ ethertype(guint16 etype, tvbuff_t *tvb, int offset_after_etype,
 		dissector_found = dissector_try_uint(ethertype_dissector_table,
 						     etype, next_tvb, pinfo, tree);
 	}
-	CATCH(BoundsError) {
-		/* Somebody threw BoundsError, which means that:
+	CATCH_NONFATAL_ERRORS {
+		/* Somebody threw an exception that means that there
+		   was a problem dissecting the payload; that means
+		   that a dissector was found, so we don't need to
+		   dissect the payload as data or update the protocol
+		   or info columns.
 
-		   1) a dissector was found, so we don't need to
-		   dissect the payload as data or update the
-		   protocol or info columns;
-
-		   2) dissecting the payload found that the packet was
-		   cut off by a snapshot length before the end of
-		   the payload.  The trailer comes after the payload,
-		   so *all* of the trailer is cut off, and we'll
-		   just get another BoundsError if we add the trailer.
-
-		   Therefore, we just rethrow the exception so it gets
-		   reported; we don't dissect the trailer or do anything
-		   else. */
-		RETHROW;
-	}
-	CATCH(OutOfMemoryError) {
-		RETHROW;
-	}
-	CATCH_ALL {
-		/* Somebody threw an exception other than BoundsError, which
-		   means that a dissector was found, so we don't need to
-		   dissect the payload as data or update the protocol or info
-		   columns.  We just show the exception and then drive on
-		   to show the trailer, after noting that a dissector was
-		   found and restoring the protocol value that was in effect
+		   Just show the exception and then drive on to show
+		   the trailer, after noting that a dissector was found
+		   and restoring the protocol value that was in effect
 		   before we called the subdissector. */
 		show_exception(next_tvb, pinfo, tree, EXCEPT_CODE, GET_MESSAGE);