Make the stuff to handle SNAP frames (OUI, PID, payload) a routine of

its own; it's used not only by LLC, but by Frame Relay with RFC 2427 and
ATM with RFC 2684.

Support for RFC 2427-encapsulation Frame Relay packets, from Paul
Ionescu.

Get rid of the CISCO_IP PPP protocol type - Cisco HDLC uses, in most
cases, Ethernet packet types, so use ETHERTYPE_IP instead (they're both
0x0800).


git-svn-id: http://anonsvn.wireshark.org/wireshark/trunk@2854 f5534014-38df-0310-8fa8-9805f1628bb7

1 files changed, 126 insertions, 44 deletions

diff --git a/packet-fr.c b/packet-fr.c
index 53f2d21a3d..76066c2ace 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 1.5 2001/01/09 09:59:28 guy Exp $
+ * $Id: packet-fr.c,v 1.6 2001/01/10 09:07:35 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@zing.org>
@@ -36,10 +36,10 @@
 #include <string.h>
 #include <glib.h>
 #include "packet.h"
-#include "packet-ip.h"
-#include "packet-ipx.h"
-#include "packet-arp.h"
-
+#include "packet-llc.h"
+#include "xdlc.h"
+#include "oui.h"
+#include "nlpid.h"
 
 static gint proto_fr    = -1;
 static gint ett_fr      = -1;
@@ -48,17 +48,26 @@ static gint hf_fr_cr	= -1;
 static gint hf_fr_becn  = -1;
 static gint hf_fr_fecn  = -1;
 static gint hf_fr_de    = -1;
-static gint hf_fr_proto = -1;
+static gint hf_fr_nlpid = -1;
+static gint hf_fr_oui  = -1;
+static gint hf_fr_pid  = -1;
+static gint hf_fr_type  = -1;
+
+static dissector_table_t fr_subdissector_table;
+static dissector_table_t fr_cisco_subdissector_table;
 
-static dissector_handle_t ip_handle;
-static dissector_handle_t ipx_handle;
+static void dissect_lapf(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree);
+static void dissect_fr_xid(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree);
+
+/* see RFC2427 / RFC1490 and Cisco encapsulation */
 
 static void dissect_fr(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 {
   proto_item *ti;
-  proto_tree *fr_tree;
-  guint16 fr_header,fr_proto;
-  tvbuff_t   *next_tvb; 
+  proto_tree *fr_tree = NULL;
+  guint16 fr_header,fr_type,offset=2; /* default header length of FR is 2 bytes */
+  
+  guint8  fr_nlpid,fr_ctrl;
     
   CHECK_DISPLAY_AS_DATA(proto_fr, tvb, pinfo, tree);
 
@@ -69,14 +78,14 @@ static void dissect_fr(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
       col_clear(pinfo->fd, COL_INFO);
 
   fr_header = tvb_get_ntohs( tvb, 0 );
-  fr_proto  = tvb_get_ntohs( tvb, 2 );
   if (check_col(pinfo->fd, COL_INFO)) 
-      col_add_fstr(pinfo->fd, COL_INFO, "DLCI %u, proto 0x%04x",
-		   ((fr_header&0x00FF)>>4)+((fr_header&0xFC00)>>6),
-		   fr_proto);
+      col_add_fstr(pinfo->fd, COL_INFO, "DLCI %u",
+		   ((fr_header&0x00FF)>>4)+((fr_header&0xFC00)>>6));
   
+  fr_header = tvb_get_ntohs( tvb, 0 );
+  fr_ctrl   = tvb_get_guint8( tvb,offset);
+            	
   if (tree) {
-	
       ti = proto_tree_add_protocol_format(tree, proto_fr, tvb, 0, 4, "Frame Relay");
       fr_tree = proto_item_add_subtree(ti, ett_fr);
      
@@ -86,28 +95,94 @@ static void dissect_fr(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
       proto_tree_add_boolean(fr_tree, hf_fr_fecn, tvb, 1, 1, fr_header);
       proto_tree_add_boolean(fr_tree, hf_fr_becn, tvb, 1, 1, fr_header);
       proto_tree_add_boolean(fr_tree, hf_fr_de,   tvb, 1, 1, fr_header);
-      proto_tree_add_uint(fr_tree, hf_fr_proto,tvb, 2, 2, fr_proto );
   }
 
-  next_tvb =  tvb_new_subset(tvb, 4, -1, -1);
-
-  switch (fr_proto){
-/*    case 0x0703:
-	dissect_lmi(next_tvb,pinfo,tree);
-	break;
-	this is not yet implemented
-*/
-      case 0x0800:
-	call_dissector(ip_handle,next_tvb,pinfo,tree);
-	break;
-      case 0x8137:
-	call_dissector(ipx_handle,next_tvb,pinfo,tree);
-	break;
-      default:
-	dissect_data(next_tvb,0,pinfo,tree);
-	break;	                                
+  if (fr_ctrl == XDLC_U) {
+      if (tree) {
+		proto_tree_add_text(fr_tree, tvb, offset, 0, "------- IETF Encapsulation -------");
+		/*
+		 * XXX - if we're going to show this as Unnumbered
+		 * Information, should we just hand it to
+		 * "dissect_xdlc_control()"?
+		 */
+		proto_tree_add_text(fr_tree, tvb, offset, 1, "Unnumbered Information");
+      }
+      offset++;
+      fr_nlpid = tvb_get_guint8 (tvb,offset);
+      if (fr_nlpid == 0) {
+		if (tree)
+			proto_tree_add_text(fr_tree, tvb, offset, 1, "Padding");
+		offset++;
+		fr_nlpid=tvb_get_guint8( tvb,offset);
+      }
+      if (tree)
+		proto_tree_add_uint(fr_tree, hf_fr_nlpid, tvb, offset, 1, fr_nlpid );
+      offset++;
+
+      if (fr_nlpid == NLPID_SNAP) {
+		dissect_snap(tvb, offset, pinfo, tree, fr_tree, fr_ctrl,
+		      hf_fr_oui, hf_fr_type, hf_fr_pid, 0);
+		return;
+      }
+		                                  
+      /*
+       * XXX - we should just call "dissect_osi()" here, but
+       * some of the routines "dissect_osi()" calls themselves put
+       * the NLPID into the tree, and not everything registered with
+       * "fr.ietf" is also registered with "osinl".
+       *
+       * We'd need to figure out what to do with the NLPID.
+       * "dissect_osi()" is registered with the "llc.dsap" dissector
+       * table, so if it were to put the NLPID into the protocol
+       * tree it'd have to create its own subtree for it - not all its
+       * callers can do that for it (without knowing whether they're
+       * going to call it or not, and the LLC dissector doesn't).
+       *
+       * Currently, it hands the NLPID as part of the tvbuff to
+       * the sub-dissectors it calls; if none of them need to look
+       * at it, we could perhaps have it put the NLPID into the
+       * tree and *not* have the subdissectors expect it - that's
+       * what would have to be done for IP, for example, as IP,
+       * unlike CLNP, doesn't expect an NLPID as the first byte.
+       */
+      if (!dissector_try_port(fr_subdissector_table,fr_nlpid, tvb_new_subset(tvb,offset,-1,-1), pinfo, tree))
+		dissect_data(tvb_new_subset(tvb,offset,-1,-1), 0, pinfo, tree);
+      return;
+  } else {
+      if ((fr_header && 0xFCF0) == 0) {
+		/* this must be some sort of lapf on DLCI 0 for SVC */
+		/* because DLCI 0 is rezerved for LMI and  SVC signaling encaplulated in lapf */
+		/* and LMI is transmitted in unnumbered information (03) */
+		/* so this must be lapf (guessing) */
+		dissect_lapf(tvb_new_subset(tvb,offset,-1,-1),pinfo,tree);
+		return;
+      }
+      if (fr_ctrl == (XDLC_U|XDLC_XID)) {
+		dissect_fr_xid(tvb_new_subset(tvb,offset,-1,-1),pinfo,tree);
+		return;
+      }
+
+      /*
+       * If the data does not start with unnumbered information (03) and
+       * the DLCI# is not 0, then there may be Cisco Frame Relay encapsulation.
+       */
+      proto_tree_add_text(fr_tree, tvb, offset, 0, "------- Cisco Encapsulation -------");
+      fr_type  = tvb_get_ntohs( tvb, offset);
+      proto_tree_add_uint(fr_tree, hf_fr_type,tvb, offset, 2, fr_type ); 
+      if (!dissector_try_port(fr_cisco_subdissector_table,fr_type, tvb_new_subset(tvb,offset+2,-1,-1), pinfo, tree))
+		dissect_data(tvb_new_subset(tvb,offset+2,-1,-1), offset+2, pinfo, tree);
   }
-  return;
+}
+
+static void dissect_lapf(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+	proto_tree_add_text(tree, tvb, 0, 0, "Frame relay lapf not yet implemented");
+	dissect_data(tvb_new_subset(tvb,0,-1,-1),0,pinfo,tree);
+}
+static void dissect_fr_xid(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+	proto_tree_add_text(tree, tvb, 0, 0, "Frame relay xid not yet implemented");
+	dissect_data(tvb_new_subset(tvb,0,-1,-1),0,pinfo,tree);
 }
  
 /* Register the protocol with Ethereal */
@@ -129,9 +204,18 @@ void proto_register_fr(void)
         { &hf_fr_de, { 
            "DE", "fr.de", FT_BOOLEAN, 16, 
             NULL, 0x0002, "Discard Eligibility" }},
-        { &hf_fr_proto, { 
-           "Encapsulated Protocol", "fr.proto", FT_UINT16, BASE_HEX, 
-            NULL, 0x0, "FrameRelay Encapsulated Protocol" }},
+        { &hf_fr_nlpid, { 
+           "NLPID", "fr.nlpid", FT_UINT8, BASE_HEX, 
+            NULL, 0x0, "FrameRelay Encapsulated Protocol NLPID" }},
+	{ &hf_fr_oui, {
+	   "Organization Code",	"fr.snap.oui", FT_UINT24, BASE_HEX, 
+	   VALS(oui_vals), 0x0, ""}},
+	{ &hf_fr_pid, {
+	   "Protocol ID", "fr.snap.pid", FT_UINT16, BASE_HEX, 
+	   NULL, 0x0, ""}},
+        { &hf_fr_type, { 
+           "Type", "fr.type", FT_UINT16, BASE_HEX, 
+            NULL, 0x0, "FrameRelay SNAP Encapsulated Protocol" }},
   };
 
 
@@ -145,15 +229,13 @@ void proto_register_fr(void)
   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)
 {
-  /*
-   * Get handles for the IP and IPX dissectors.
-   */
-  ip_handle = find_dissector("ip");
-  ipx_handle = find_dissector("ipx");
-
   dissector_add("wtap_encap", WTAP_ENCAP_FRELAY, dissect_fr, proto_fr);
 }