Make GRE use a dissector table for its protocol types, and register

dissectors for protcools that can be encapsulated inside GRE in that
table.

Fix a bug in the handling of WCCPv2 IP encapsulation (it was
constructing the next tvbuff before, rather than after, advancing the
offset past the redirection header).

svn path=/trunk/; revision=2893

8 files changed, 81 insertions, 65 deletions

diff --git a/Makefile.am b/Makefile.am
index 1f7929aebe..badb6c247f 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,7 +1,7 @@
 # Makefile.am
 # Automake file for Ethereal
 #
-# $Id: Makefile.am,v 1.275 2001/01/13 03:17:15 gram Exp $
+# $Id: Makefile.am,v 1.276 2001/01/13 07:47:48 guy Exp $
 #
 # Ethereal - Network traffic analyzer
 # By Gerald Combs <gerald@zing.org>
@@ -279,6 +279,7 @@ ETHEREAL_COMMON_SOURCES = \
 	etypes.h       \
 	follow.c       \
 	follow.h       \
+	greproto.h     \
 	in_cksum.c     \
 	in_cksum.h     \
 	ipproto.c      \
diff --git a/etypes.h b/etypes.h
index d7a5e70f1a..0c21cc4bb2 100644
--- a/etypes.h
+++ b/etypes.h
@@ -1,7 +1,7 @@
 /* etypes.h
  * Defines ethernet packet types, similar to tcpdump's ethertype.h
  *
- * $Id: etypes.h,v 1.14 2000/08/09 22:10:23 deniel Exp $
+ * $Id: etypes.h,v 1.15 2001/01/13 07:47:48 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -154,6 +154,10 @@
 #define ETHERTYPE_MPLS_MULTI 0x8848 /* MPLS multicast packet */
 #endif
 
+#ifndef ETHERTYPE_PPP
+#define ETHERTYPE_PPP	0x880b	/* no, this is not PPPoE */
+#endif
+
 #endif /* etypes.h */
 
 
diff --git a/greproto.h b/greproto.h
new file mode 100644
index 0000000000..96d34227d6
--- /dev/null
+++ b/greproto.h
@@ -0,0 +1,36 @@
+/* greproto.h
+ * Protocol type values for for the Generic Routing Encapsulation (GRE)
+ * protocol
+ * Brad Robel-Forrest <brad.robel-forrest@watchguard.com>
+ *
+ * The protocol type in GRE is supposed to be an Ethernet type value;
+ * this file lists protocol type values for which nobody's found an
+ * official Ethernet type definition and put that in "etypes.h".
+ * Move these to "etypes.h" if you find an official Ethernet type
+ * definition for them; when this file is empty, get rid of all includes
+ * of it, and get rid of it.
+ *
+ * $Id: greproto.h,v 1.1 2001/01/13 07:47:48 guy Exp $
+ *
+ * Ethereal - Network traffic analyzer
+ * By Gerald Combs <gerald@zing.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.
+ */
+
+#define GRE_WCCP	0x883E
+#define GRE_FR		0x6559
diff --git a/packet-fr.c b/packet-fr.c
index 76066c2ace..89e0c8a597 100644
--- a/packet-fr.c
+++ b/packet-fr.c
@@ -3,7 +3,7 @@
  *
  * Copyright 2001, Paul Ionescu	<paul@acorp.ro>
  *
- * $Id: packet-fr.c,v 1.6 2001/01/10 09:07:35 guy Exp $
+ * $Id: packet-fr.c,v 1.7 2001/01/13 07:47:48 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -40,6 +40,7 @@
 #include "xdlc.h"
 #include "oui.h"
 #include "nlpid.h"
+#include "greproto.h"
 
 static gint proto_fr    = -1;
 static gint ett_fr      = -1;
@@ -228,14 +229,12 @@ void proto_register_fr(void)
   proto_register_field_array(proto_fr, hf, array_length(hf));
   proto_register_subtree_array(ett, array_length(ett));
 
-  register_dissector("fr", dissect_fr, proto_fr);
-
   fr_subdissector_table = register_dissector_table("fr.ietf");
   fr_cisco_subdissector_table = register_dissector_table("fr.cisco");
-
-};
+}
 
 void proto_reg_handoff_fr(void)
 {
   dissector_add("wtap_encap", WTAP_ENCAP_FRELAY, dissect_fr, proto_fr);
+  dissector_add("gre.proto", GRE_FR, dissect_fr, proto_fr);
 }
diff --git a/packet-gre.c b/packet-gre.c
index fc79ce9405..8fcb87f3a5 100644
--- a/packet-gre.c
+++ b/packet-gre.c
@@ -2,7 +2,7 @@
  * Routines for the Generic Routing Encapsulation (GRE) protocol
  * Brad Robel-Forrest <brad.robel-forrest@watchguard.com>
  *
- * $Id: packet-gre.c,v 1.37 2001/01/09 09:59:28 guy Exp $
+ * $Id: packet-gre.c,v 1.38 2001/01/13 07:47:48 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -36,6 +36,8 @@
 #include <netinet/in.h>
 #endif
 #include <glib.h>
+#include "etypes.h"
+#include "greproto.h"
 #include "packet.h"
 #include "packet-ip.h"
 #include "packet-ipx.h"
@@ -49,6 +51,8 @@ static gint ett_gre = -1;
 static gint ett_gre_flags = -1;
 static gint ett_gre_wccp2_redirect_header = -1;
 
+static dissector_table_t gre_dissector_table;
+
 /* bit positions for flags in header */
 #define GH_B_C		0x8000
 #define GH_B_R		0x4000
@@ -61,29 +65,18 @@ static gint ett_gre_wccp2_redirect_header = -1;
 #define GH_R_FLAGS	0x00F8
 #define GH_B_VER	0x0007
 
-#define GRE_PPP		0x880B
-#define	GRE_IP		0x0800
-#define GRE_WCCP	0x883E
-#define GRE_IPX		0x8137
-#define GRE_FR		0x6559
-
 static void add_flags_and_ver(proto_tree *, guint16, tvbuff_t *, int, int);
 static void dissect_gre_wccp2_redirect_header(tvbuff_t *, int, proto_tree *);
 
 static const value_string typevals[] = {
-	{ GRE_PPP,  "PPP" },
-	{ GRE_IP,   "IP" },
-	{ GRE_WCCP, "WCCP"},
-	{ GRE_IPX,  "IPX"},
-        { GRE_FR,   "FR"},
-	{ 0,        NULL  }
+	{ ETHERTYPE_PPP, "PPP" },
+	{ ETHERTYPE_IP,  "IP" },
+	{ GRE_WCCP,      "WCCP"},
+	{ ETHERTYPE_IPX, "IPX"},
+	{ GRE_FR,        "FR"},
+	{ 0,             NULL  }
 };
 
-static dissector_handle_t ip_handle;
-static dissector_handle_t ipx_handle;
-static dissector_handle_t ppp_handle;
-static dissector_handle_t fr_handle;
-
 static void
 dissect_gre(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 {
@@ -122,7 +115,7 @@ dissect_gre(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
     len += 4;
   switch (type) {
 
-  case GRE_PPP:
+  case ETHERTYPE_PPP:
     if (flags_and_ver & GH_P_A)
       len += 4;
     is_ppp = TRUE;
@@ -257,32 +250,16 @@ dissect_gre(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
     }
   }
 
-  next_tvb = tvb_new_subset(tvb, offset, -1, -1);
-  switch (type) {
-    case GRE_PPP:
-      call_dissector(ppp_handle, next_tvb, pinfo, tree);
-      break;
-    case GRE_IP:
-      call_dissector(ip_handle, next_tvb, pinfo, tree);
-      break;
-    case GRE_WCCP:
-      if (is_wccp2) {
-      	if (tree)
-          dissect_gre_wccp2_redirect_header(tvb, offset, gre_tree);
-        offset += 4;
-      }
-      call_dissector(ip_handle, next_tvb, pinfo, tree);
-      break;
-    case GRE_IPX:
-      call_dissector(ipx_handle, next_tvb, pinfo, tree);
-      break;
-    case GRE_FR:
-      call_dissector(fr_handle, next_tvb, pinfo, tree);
-      break;        
-    default:
-      dissect_data(next_tvb, 0, pinfo, gre_tree);
-      break;
+  if (type == GRE_WCCP) {
+    if (is_wccp2) {
+      if (tree)
+        dissect_gre_wccp2_redirect_header(tvb, offset, gre_tree);
+      offset += 4;
+    }
   }
+  next_tvb = tvb_new_subset(tvb, offset, -1, -1);
+  if (!dissector_try_port(gre_dissector_table, type, next_tvb, pinfo, tree))
+    dissect_data(next_tvb, 0, pinfo, gre_tree);
 }
 
 static void
@@ -380,18 +357,13 @@ proto_register_gre(void)
 	    "GRE", "gre");
         proto_register_field_array(proto_gre, hf, array_length(hf));
 	proto_register_subtree_array(ett, array_length(ett));
+
+	/* subdissector code */
+	gre_dissector_table = register_dissector_table("gre.proto");
 }
 
 void
 proto_reg_handoff_gre(void)
 {
 	dissector_add("ip.proto", IP_PROTO_GRE, dissect_gre, proto_gre);
-
-	/*
-	 * Get handles for the IP, IPX, PPP, and Frame Relay dissectors.
-	 */
-	ip_handle = find_dissector("ip");
-	ipx_handle = find_dissector("ipx");
-	ppp_handle = find_dissector("ppp");
-	fr_handle = find_dissector("fr");
 }
diff --git a/packet-ip.c b/packet-ip.c
index e3beb3c186..3eaa63c54b 100644
--- a/packet-ip.c
+++ b/packet-ip.c
@@ -1,7 +1,7 @@
 /* packet-ip.c
  * Routines for IP and miscellaneous IP protocol packet disassembly
  *
- * $Id: packet-ip.c,v 1.120 2001/01/10 09:07:35 guy Exp $
+ * $Id: packet-ip.c,v 1.121 2001/01/13 07:47:48 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -47,6 +47,7 @@
 #include "resolv.h"
 #include "prefs.h"
 #include "etypes.h"
+#include "greproto.h"
 #include "ppptypes.h"
 #include "llcsaps.h"
 #include "aftypes.h"
@@ -1483,13 +1484,14 @@ proto_reg_handoff_ip(void)
 	dissector_add("ethertype", ETHERTYPE_IP, dissect_ip, proto_ip);
 	dissector_add("ppp.protocol", PPP_IP, dissect_ip, proto_ip);
 	dissector_add("ppp.protocol", ETHERTYPE_IP, dissect_ip, proto_ip);
+	dissector_add("gre.proto", ETHERTYPE_IP, dissect_ip, proto_ip);
+	dissector_add("gre.proto", GRE_WCCP, dissect_ip, proto_ip);
 	dissector_add("llc.dsap", SAP_IP, dissect_ip, proto_ip);
 	dissector_add("ip.proto", IP_PROTO_IPV4, dissect_ip, proto_ip);
 	dissector_add("ip.proto", IP_PROTO_IPIP, dissect_ip, proto_ip);
 	dissector_add("null.type", BSD_AF_INET, dissect_ip, proto_ip);
-        dissector_add("fr.cisco", ETHERTYPE_IP, dissect_ip, proto_ip);
-        dissector_add("fr.ietf", NLPID_IP, dissect_ip, proto_ip);
-        
+	dissector_add("fr.cisco", ETHERTYPE_IP, dissect_ip, proto_ip);
+	dissector_add("fr.ietf", NLPID_IP, dissect_ip, proto_ip);
 }
 
 void
diff --git a/packet-ipx.c b/packet-ipx.c
index 53e79ad8e6..7e9277cedc 100644
--- a/packet-ipx.c
+++ b/packet-ipx.c
@@ -2,7 +2,7 @@
  * Routines for NetWare's IPX
  * Gilbert Ramirez <gram@xiexie.org>
  *
- * $Id: packet-ipx.c,v 1.75 2001/01/10 09:07:35 guy Exp $
+ * $Id: packet-ipx.c,v 1.76 2001/01/13 07:47:48 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -920,6 +920,7 @@ proto_reg_handoff_ipx(void)
 	dissector_add("ppp.protocol", PPP_IPX, dissect_ipx, proto_ipx);
 	dissector_add("llc.dsap", SAP_NETWARE, dissect_ipx, proto_ipx);
 	dissector_add("null.type", BSD_AF_IPX, dissect_ipx, proto_ipx);
+	dissector_add("gre.proto", ETHERTYPE_IPX, dissect_ipx, proto_ipx);
 	dissector_add("ipx.packet_type", IPX_PACKET_TYPE_SPX, dissect_spx,
 	    proto_spx);
 	dissector_add("ipx.socket", IPX_SOCKET_SAP, dissect_ipxsap,
diff --git a/packet-ppp.c b/packet-ppp.c
index ebea398650..ab9d851ebe 100644
--- a/packet-ppp.c
+++ b/packet-ppp.c
@@ -1,7 +1,7 @@
 /* packet-ppp.c
  * Routines for ppp packet disassembly
  *
- * $Id: packet-ppp.c,v 1.52 2001/01/10 09:07:35 guy Exp $
+ * $Id: packet-ppp.c,v 1.53 2001/01/13 07:47:49 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -1473,4 +1473,5 @@ proto_reg_handoff_ppp(void)
   dissector_add("wtap_encap", WTAP_ENCAP_PPP, dissect_ppp, proto_ppp);
   dissector_add("wtap_encap", WTAP_ENCAP_PPP_WITH_PHDR, dissect_ppp, proto_ppp);
   dissector_add("fr.ietf", NLPID_PPP, dissect_ppp, proto_ppp);
+  dissector_add("gre.proto", ETHERTYPE_PPP, dissect_ppp, proto_ppp);
 }