From: Tobias Witek: Fix processing of radius 'vendor specific attributes'

In the RADIUS dissector, the function radius_register_avp_dissector() registers
vendors that are not already present in the dictionary hash-table. As far as I
can see, there are two problems with this:

1. The function does not set the number of type/length octets and the has_flags
 variable for that AVP, which is required to correctly decode AVP/VSA values
2. In some situations, the function is called _before_ radius_load_dictionary()
is called (for example for the vendor 3GPP (ID: 10415))

Therefore, all vendor entries that are created by calling
radius_register_avp_dissector() leave their type_octets and length_octets un-initialized,
which causes incorrect decoding.

[Result: Radius dissector displays messages such as:
 "Malformed Packet: RADIUS" and "Error/Malformed: Malformed Packet(Exception occurred)"]

The attached patch fixes this problem by assuming that the dictionary knows the
'ground truth' about the type/length octet and the has_flags information and allows it to
overwrite these values even for vendors that have already been loaded.

Also: (from Bill Meier): set the type/length octet and the has_flags variables to default
"standard" values (1,1,FALSE) in radius_register_avp_dissector().

Fixes Bug #3651 (and Bug #3635).
https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=3651
https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=3635

svn path=/trunk/; revision=28937

1 files changed, 7 insertions, 3 deletions

diff --git a/epan/radius_dict.l b/epan/radius_dict.l
index 6d7337e4cd..719b752278 100644
--- a/epan/radius_dict.l
+++ b/epan/radius_dict.l
@@ -305,10 +305,14 @@ void add_vendor(const gchar* name, guint32 vendor_id, guint vendor_type_octets,
 		v->code = vendor_id;
 		v->ett = -1;
 		v->name = NULL;
-		v->type_octets = vendor_type_octets;
-		v->length_octets = vendor_length_octets;
-		v->has_flags = vendor_has_flags; 
 	}
+        /* Assume that the dictionary knows the 'ground truth' about the 
+         * type/length/has_flags information and thus allow the dictionary to
+         * overwrite these values even for vendors that have already been loaded.
+         */
+	v->type_octets = vendor_type_octets;
+	v->length_octets = vendor_length_octets;
+	v->has_flags = vendor_has_flags; 
 
 	if (v->name)
 		g_free((gpointer) v->name);