Wireshark · Ethereal-dev: [Ethereal-dev] some plugin problems

[Ed Warnicke <hagbard@xxxxxxxxxxxxxxxxxxx>]

I decided to go the new-style plugin route as the mgcp dissector 
is a new style dissector.  As a normal dissector the module worked 
(mostly, there are still lots of small things I'd like to fix or enhance).

I think I figured out all of the appropriate places in the 
Makefile.am files and the configure.in to alter to add the mgcp 
plugin ( note, this is not nearly as easy as adding a dissector).

But when I make (or attempt to run the result of make;make install) 
I get the complaint:

** WARNING **: The plugin mgcp.so has no protocol symbol and no
plugin_reg_handoff symbol

And naturally, the plugin doesn't show up while ethereal is running
(no presence on the Edit->Protocols list).  

Now my understanding of the world was such that a new style dissector
did not need the protocol symbol and that having a 
void plugin_reg_handoff
function defined ( with no static modifier) was sufficient to insure 
the presence of appropriate symbols.  Clearly there is something 
basic that I'm not understanding.  

I've attached the output of running cvs diff in the ethereal/ directory 
and a tarball of the ethereal/plugin/mgcp directory which contains 
the meat of things (if someone could tell me how to incorporate 
this into the patch I would very appreciative).  

To make it simpler to understand how I came to go from a working 
dissector to a not-quite working plugin I've included the diff between
the two below.

I feel strongly that my mistake is something really stupid and 
obvious that I just don't see for lack of experience and so am 
requesting assistance.

Ed

--- ../../packet-mgcp.c	Sun Nov  5 03:14:04 2000
+++ ethereal/plugins/mgcp/packet-mgcp.c	Sun Nov  5 20:01:44 2000
@@ -47,6 +47,11 @@
 #include "prefs.h"
 #include "strutil.h"
 
+/* Includes for the plugin stuff */
+#include "plugins/plugin_api.h"
+#include "moduleinfo.h"
+
+DLLEXPORT const gchar version[] = VERSION;
 
 #define TCP_PORT_MGCP_GATEWAY 2427
 #define UDP_PORT_MGCP_GATEWAY 2427
@@ -981,3 +986,20 @@
   return (tvb_linebegin);
 }
 
+void plugin_reg_handoff(void){
+  proto_reg_handoff_mgcp();
+}
+
+DLLEXPORT void plugin_init(plugin_address_table_t *pat){
+  /* initialise the table of pointers needed in Win32 DLLs */
+  plugin_address_table_init(pat);
+  /* destroy the dfilter tree */
+  dfilter_cleanup();
+  /* register the new protocol, protocol fields, and subtrees */
+  if (proto_mgcp == -1) { /* execute protocol initialization only once */
+    proto_register_mgcp();
+  }
+  /* initialize the dfilter tree with all the header field and protocol
+   * abbrevs defined, including xxx */
+  dfilter_init();  
+}


? ethereal-0.8.13
? cscope.out
? make.log
? plugins/mgcp
Index: Makefile.am
===================================================================
RCS file: /cvsroot/ethereal/Makefile.am,v
retrieving revision 1.241
diff -u -r1.241 Makefile.am
--- Makefile.am	2000/11/04 07:50:47	1.241
+++ Makefile.am	2000/11/06 01:08:38
@@ -344,7 +344,8 @@
 ethereal_DEPENDENCIES = \
 	$(ethereal_optional_objects)	\
 	$(ethereal_additional_libs)	\
-	plugins/gryphon/gryphon.la
+	plugins/gryphon/gryphon.la	\
+	plugins/mgcp/mgcp.la
 
 ethereal_static_DEPENDENCIES = \
 	$(ethereal_optional_objects)	\
@@ -362,7 +363,8 @@
 	$(ethereal_additional_libs)	\
 	@SNMP_LIBS@			\
 	"-dlopen" self	\
-	"-dlopen" plugins/gryphon/gryphon.la @PCAP_LIBS@ @GTK_LIBS@
+	"-dlopen" plugins/gryphon/gryphon.la @PCAP_LIBS@ @GTK_LIBS@	\
+	"-dlopen" plugins/mgcp/mgcp.la @PCAP_LIBS@ @GTK_LIBS@
 
 ethereal_static_LDADD = \
 	$(ethereal_optional_objects)	\
@@ -386,7 +388,8 @@
 tethereal_DEPENDENCIES = \
 	$(ethereal_optional_objects)	\
 	$(tethereal_additional_libs)	\
-	plugins/gryphon/gryphon.la
+	plugins/gryphon/gryphon.la	\
+	plugins/mgcp/mgcp.la	
 
 # This automake variable adds to the link-line for the executable
 tethereal_LDADD = wiretap/libwiretap.a	\
@@ -395,6 +398,8 @@
 	@SNMP_LIBS@			\
 	"-dlopen" self	\
 	"-dlopen" plugins/gryphon/gryphon.la @GLIB_LIBS@ -lm \
+	@PCAP_LIBS@ @SOCKET_LIBS@ @NSL_LIBS@	\
+	"-dlopen" plugins/mgcp/mgcp.la @GLIB_LIBS@ -lm \
 	@PCAP_LIBS@ @SOCKET_LIBS@ @NSL_LIBS@
 
 tethereal_LDFLAGS = -export-dynamic
Index: configure.in
===================================================================
RCS file: /cvsroot/ethereal/configure.in,v
retrieving revision 1.107
diff -u -r1.107 configure.in
--- configure.in	2000/10/27 02:22:04	1.107
+++ configure.in	2000/11/06 01:08:39
@@ -414,4 +414,5 @@
   packaging/svr4/checkinstall
   packaging/svr4/pkginfo
   plugins/Makefile
-  plugins/gryphon/Makefile)
+  plugins/gryphon/Makefile
+  plugins/mgcp/Makefile)
Index: plugins/Makefile.am
===================================================================
RCS file: /cvsroot/ethereal/plugins/Makefile.am,v
retrieving revision 1.5
diff -u -r1.5 Makefile.am
--- Makefile.am	2000/03/15 19:09:16	1.5
+++ Makefile.am	2000/11/06 01:08:41
@@ -22,7 +22,7 @@
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 
-SUBDIRS = gryphon
+SUBDIRS = gryphon mgcp
 
 plugindir = @PLUGIN_DIR@
 
@@ -31,3 +31,6 @@
 	plugin_api.h	\
 	plugin_table.h	\
 	Makefile.nmake
+
+
+

Attachment: mgcp-plugin.tar.gz
Description: tarball of the new ethereal/plugin/mgcp directory