Revert Revision 34838 "Resolve bug #2254: Migrate the 802.1q VLAN dissector into the Ethernet II."

as this causes a lot of problems.
See 
https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=5680
https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=6305
https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=6366

Original bug:
https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=2254

svn path=/trunk/; revision=39100

6 files changed, 275 insertions, 94 deletions

diff --git a/epan/dissectors/packet-eth.c b/epan/dissectors/packet-eth.c
index 420182279a..d9d2696207 100644
--- a/epan/dissectors/packet-eth.c
+++ b/epan/dissectors/packet-eth.c
@@ -51,18 +51,12 @@ static gboolean ccsds_heuristic_length = FALSE;
 static gboolean ccsds_heuristic_version = FALSE;
 static gboolean ccsds_heuristic_header = FALSE;
 static gboolean ccsds_heuristic_bit = FALSE;
-/*  Preference moved over from the old vlan dissector */
-static guint q_in_q_ethertype = 0x9100;
 
 /* protocols and header fields */
 static int proto_eth = -1;
 static int hf_eth_dst = -1;
 static int hf_eth_src = -1;
 static int hf_eth_len = -1;
-static int hf_eth_vlan_tpid = -1;
-static int hf_eth_vlan_pri = -1;
-static int hf_eth_vlan_cfi = -1;
-static int hf_eth_vlan_id = -1;
 static int hf_eth_type = -1;
 static int hf_eth_invalid_lentype = -1;
 static int hf_eth_addr = -1;
@@ -74,7 +68,6 @@ static gint ett_ieee8023 = -1;
 static gint ett_ether2 = -1;
 static gint ett_ether = -1;
 static gint ett_addr = -1;
-static gint ett_tag = -1;
 
 static dissector_handle_t fw1_handle;
 static dissector_handle_t data_handle;
@@ -83,25 +76,6 @@ static heur_dissector_list_t eth_trailer_subdissector_list;
 
 static int eth_tap = -1;
 
-/* From Table G-2 of IEEE standard 802.1D-2004 */
-static const value_string pri_vals[] = {
-    { 1, "Background"                        },
-    { 2, "Spare"                             },
-    { 0, "Best Effort (default)"             },
-    { 3, "Excellent Effort"                  },
-    { 4, "Controlled Load"                   },
-    { 5, "Video, < 100ms latency and jitter" },
-    { 6, "Voice, < 10ms latency and jitter"  },
-    { 7, "Network Control"                   },
-    { 0, NULL                                }
-};
-
-static const value_string cfi_vals[] = {
-  { 0, "Canonical"     },
-  { 1, "Non-canonical" },
-  { 0, NULL            }
-};
-
 #define ETH_HEADER_SIZE    14
 
 static const true_false_string ig_tfs = {
@@ -225,7 +199,7 @@ static void
 dissect_eth_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree,
     int fcs_len)
 {
-  proto_item        *ti = NULL, *tag_item;
+  proto_item        *ti = NULL;
   eth_hdr           *ehdr;
   gboolean          is_802_2;
   proto_tree        *fh_tree = NULL;
@@ -235,10 +209,7 @@ dissect_eth_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree,
   proto_tree        *tree;
   proto_item        *addr_item;
   proto_tree        *addr_tree=NULL;
-  proto_tree        *tag_tree;
   gint              offset;
-  guint8            tag_pri;
-  guint16           tag_vlan_id;
 
   ehdr_num++;
   if(ehdr_num>=4){
@@ -389,15 +360,10 @@ dissect_eth_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree,
         }
     }
 
-    col_set_str(pinfo->cinfo, COL_INFO, "Ethernet II");
-    if(ehdr->type == ETHERTYPE_VLAN || ehdr->type == q_in_q_ethertype)
-      col_append_str(pinfo->cinfo, COL_INFO, " (VLAN tagged)");
-
     if (parent_tree) {
         if (PTREE_DATA(parent_tree)->visible) {
             ti = proto_tree_add_protocol_format(parent_tree, proto_eth, tvb, 0,
                 ETH_HEADER_SIZE, "Ethernet II%s, Src: %s (%s), Dst: %s (%s)",
-                (ehdr->type == ETHERTYPE_VLAN || ehdr->type == q_in_q_ethertype) ? " (VLAN tagged)" : "",
                 get_ether_name(src_addr), ether_to_str(src_addr),
                 get_ether_name(dst_addr), ether_to_str(dst_addr));
       }
@@ -428,31 +394,6 @@ dissect_eth_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree,
     proto_tree_add_item(addr_tree, hf_eth_ig, tvb, 6, 3, FALSE);
 
     offset = 12;
-    while(ehdr->type == ETHERTYPE_VLAN || ehdr->type == q_in_q_ethertype) {
-      tag_item = proto_tree_add_text(fh_tree, tvb, offset, 4, "VLAN tag: ");
-      tag_tree = proto_item_add_subtree(tag_item, ett_tag);
-
-      proto_tree_add_item(tag_tree, hf_eth_vlan_tpid, tvb, offset, 2, FALSE);
-      offset += 2;
-
-      proto_tree_add_item(tag_tree, hf_eth_vlan_pri, tvb, offset, 2, FALSE);
-      tag_pri = tvb_get_guint8(tvb, offset) >> 5;
-
-      proto_tree_add_item(tag_tree, hf_eth_vlan_cfi, tvb, offset, 2, FALSE);
-
-      proto_tree_add_item(tag_tree, hf_eth_vlan_id, tvb, offset, 2, FALSE);
-      tag_vlan_id = tvb_get_ntohs(tvb, offset) & 0x0FFF;
-
-      proto_item_append_text(tag_item, "VLAN=%u, Priority=%s", tag_vlan_id,
-        val_to_str(tag_pri, pri_vals, "Unknown"));
-
-      if(check_col(pinfo->cinfo, COL_8021Q_VLAN_ID))
-        col_add_fstr(pinfo->cinfo, COL_8021Q_VLAN_ID, "%u", tag_vlan_id);
-
-      offset += 2;
-
-      ehdr->type = tvb_get_ntohs(tvb, offset);
-    }
     offset += 2;
     proto_item_set_len(ti, offset);
 
@@ -702,22 +643,6 @@ proto_register_eth(void)
         { "Invalid length/type", "eth.invalid_lentype", FT_UINT16, BASE_HEX_DEC,
             NULL, 0x0, NULL, HFILL }},
 
-        { &hf_eth_vlan_tpid,
-        { "Identifier", "eth.vlan.tpid", FT_UINT16, BASE_HEX, VALS(etype_vals), 0x0,
-            "Tag Protocol Identifier (TPID)", HFILL }},
-
-        { &hf_eth_vlan_pri,
-        { "Priority", "eth.vlan.pri", FT_UINT16, BASE_DEC, VALS(pri_vals), 0xE000,
-            "Priority Code Point (PCP)", HFILL }},
-
-        { &hf_eth_vlan_cfi,
-        { "CFI", "eth.vlan.cfi", FT_UINT16, BASE_DEC, VALS(cfi_vals), 0x1000,
-            "Canonical Format Identifier", HFILL }},
-
-        { &hf_eth_vlan_id,
-        { "VLAN", "eth.vlan.id", FT_UINT16, BASE_DEC, NULL, 0x0FFF,
-            "VLAN Identifier (VID)", HFILL }},
-
         { &hf_eth_addr,
         { "Address", "eth.addr", FT_ETHER, BASE_NONE, NULL, 0x0,
             "Source or Destination Hardware Address", HFILL }},
@@ -740,8 +665,7 @@ proto_register_eth(void)
         &ett_ieee8023,
         &ett_ether2,
         &ett_ether,
-        &ett_addr,
-        &ett_tag
+        &ett_addr
     };
     module_t *eth_module;
 
@@ -768,16 +692,6 @@ proto_register_eth(void)
             "Whether packets should be interpreted as coming from CheckPoint FireWall-1 monitor file if they look as if they do",
             &eth_interpret_as_fw1_monitor);
 
-    prefs_register_uint_preference(eth_module, "qinq_ethertype",
-            "802.1QinQ Ethertype (in hex)", "The (hexadecimal) Ethertype used to indicate "
-            "802.1QinQ VLAN in VLAN tunneling.", 16, &q_in_q_ethertype);
-
-    /* This preference is copied over from the old vlan dissector by the set_pref()
-     * function in epan/prefs.c.  We don't have it in this dissector because there could
-     * be multiple VLAN tags nested within the Ethernet header, so we wouldn't know which
-     * one to show. */
-    prefs_register_obsolete_preference(eth_module, "summary_in_tree");
-
     prefs_register_static_text_preference(eth_module, "ccsds_heuristic",
             "These are the conditions to match a payload against in order to determine if this\n"
             "is a CCSDS (Consultative Committee for Space Data Systems) packet within\n"
diff --git a/epan/dissectors/packet-ethertype.c b/epan/dissectors/packet-ethertype.c
index 864f7bd28c..a97cb30340 100644
--- a/epan/dissectors/packet-ethertype.c
+++ b/epan/dissectors/packet-ethertype.c
@@ -37,10 +37,12 @@
 #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>
+#include <epan/prefs.h>
 
 static dissector_table_t ethertype_dissector_table;
 
@@ -191,7 +193,7 @@ capture_ethertype(guint16 etype, const guchar *pd, int offset, int len,
       capture_ipx(ld);
       break;
     case ETHERTYPE_VLAN:
-      capture_eth(pd, offset, len, ld);
+      capture_vlan(pd, offset, len, ld);
       break;
     case ETHERTYPE_IEEE_802_1AD:
     case ETHERTYPE_IEEE_802_1AH:
@@ -219,11 +221,21 @@ ethertype(guint16 etype, tvbuff_t *tvb, int offset_after_etype,
 	volatile gboolean	dissector_found = FALSE;
 	const char		*volatile saved_proto;
 	void			*pd_save;
+			module_t *eth_module;
+			pref_t *q_in_q_pref;
 
 	/* Add the Ethernet type to the protocol tree */
 	if (tree) {
-		proto_tree_add_uint(fh_tree, etype_id, tvb,
-		    offset_after_etype - 2, 2, etype);
+		eth_module = prefs_find_module("eth");
+		if (eth_module)
+			q_in_q_pref = prefs_find_preference(eth_module, "qinq_ethertype");
+		if (q_in_q_pref && (etype == prefs_get_uint_preference(q_in_q_pref)))
+		proto_tree_add_uint_format_value(fh_tree, etype_id, tvb,
+			offset_after_etype - 2, 2, etype, 
+			"802.1QinQ VLAN in VLAN tunneling (0x%04x)", etype);
+		else
+			proto_tree_add_uint(fh_tree, etype_id, tvb, 
+				offset_after_etype - 2, 2, etype);
 	}
 
 	/* Get the captured length and reported length of the data
diff --git a/epan/dissectors/packet-ieee8021ah.c b/epan/dissectors/packet-ieee8021ah.c
index 870c60ee9a..62e881c212 100644
--- a/epan/dissectors/packet-ieee8021ah.c
+++ b/epan/dissectors/packet-ieee8021ah.c
@@ -33,6 +33,7 @@
 #include "packet-ieee8021ah.h"
 #include "packet-ipx.h"
 #include "packet-llc.h"
+#include "packet-vlan.h"
 #include <epan/etypes.h>
 #include <epan/prefs.h>
 
diff --git a/epan/dissectors/packet-vlan.c b/epan/dissectors/packet-vlan.c
new file mode 100644
index 0000000000..e7d7007821
--- /dev/null
+++ b/epan/dissectors/packet-vlan.c
@@ -0,0 +1,219 @@
+/* packet-vlan.c
+ * Routines for VLAN 802.1Q ethernet header disassembly
+ *
+ * $Id$
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.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.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <glib.h>
+#include <epan/packet.h>
+#include "packet-ieee8023.h"
+#include "packet-ipx.h"
+#include "packet-llc.h"
+#include "packet-vlan.h"
+#include <epan/etypes.h>
+#include <epan/prefs.h>
+
+void proto_reg_handoff_vlan(void);
+
+static unsigned int q_in_q_ethertype = 0x9100;
+
+static gboolean vlan_summary_in_tree = TRUE;
+
+static int proto_vlan = -1;
+static int hf_vlan_priority = -1;
+static int hf_vlan_cfi = -1;
+static int hf_vlan_id = -1;
+static int hf_vlan_etype = -1;
+static int hf_vlan_len = -1;
+static int hf_vlan_trailer = -1;
+
+static gint ett_vlan = -1;
+
+/* From Table G-2 of IEEE standard 802.1D-2004 */
+static const value_string pri_vals[] = {
+	{ 1, "Background"                        },
+	{ 2, "Spare"                             },
+	{ 0, "Best Effort (default)"             },
+	{ 3, "Excellent Effort"                  },
+	{ 4, "Controlled Load"                   },
+	{ 5, "Video, < 100ms latency and jitter" },
+	{ 6, "Voice, < 10ms latency and jitter"  },
+	{ 7, "Network Control"                   },
+	{ 0, NULL                                }
+};
+
+static const value_string cfi_vals[] = {
+	{ 0, "Canonical"     },
+	{ 1, "Non-canonical" },
+	{ 0, NULL            }
+};
+
+
+void
+capture_vlan(const guchar *pd, int offset, int len, packet_counts *ld ) {
+  guint16 encap_proto;
+  if ( !BYTES_ARE_IN_FRAME(offset,len,5) ) {
+    ld->other++;
+    return;
+  }
+  encap_proto = pntohs( &pd[offset+2] );
+  if ( encap_proto <= IEEE_802_3_MAX_LEN) {
+    if ( pd[offset+4] == 0xff && pd[offset+5] == 0xff ) {
+      capture_ipx(ld);
+    } else {
+      capture_llc(pd,offset+4,len,ld);
+    }
+  } else {
+    capture_ethertype(encap_proto, pd, offset+4, len, ld);
+  }
+}
+
+static void
+dissect_vlan(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+  proto_item *ti;
+  guint16 tci;
+  volatile guint16 encap_proto;
+  volatile gboolean is_802_2;
+  proto_tree *volatile vlan_tree;
+
+  col_set_str(pinfo->cinfo, COL_PROTOCOL, "VLAN");
+  col_clear(pinfo->cinfo, COL_INFO);
+
+  tci = tvb_get_ntohs( tvb, 0 );
+
+  col_add_fstr(pinfo->cinfo, COL_INFO, "PRI: %u  CFI: %u  ID: %u",
+	      (tci >> 13), ((tci >> 12) & 1), (tci & 0xFFF));
+  col_add_fstr(pinfo->cinfo, COL_8021Q_VLAN_ID, "%u", (tci & 0xFFF));
+
+  vlan_tree = NULL;
+
+  if (tree) {
+    ti = proto_tree_add_item(tree, proto_vlan, tvb, 0, 4, FALSE);
+
+    if (vlan_summary_in_tree) {
+        proto_item_append_text(ti, ", PRI: %u, CFI: %u, ID: %u",
+                (tci >> 13), ((tci >> 12) & 1), (tci & 0xFFF));
+    }
+
+    vlan_tree = proto_item_add_subtree(ti, ett_vlan);
+
+    proto_tree_add_item(vlan_tree, hf_vlan_priority, tvb, 0, 2, FALSE);
+    proto_tree_add_item(vlan_tree, hf_vlan_cfi, tvb, 0, 2, FALSE);
+    proto_tree_add_item(vlan_tree, hf_vlan_id, tvb, 0, 2, FALSE);
+  }
+
+  encap_proto = tvb_get_ntohs(tvb, 2);
+  if (encap_proto <= IEEE_802_3_MAX_LEN) {
+    /* Is there an 802.2 layer? I can tell by looking at the first 2
+       bytes after the VLAN header. If they are 0xffff, then what
+       follows the VLAN header is an IPX payload, meaning no 802.2.
+       (IPX/SPX is they only thing that can be contained inside a
+       straight 802.3 packet, so presumably the same applies for
+       Ethernet VLAN packets). A non-0xffff value means that there's an
+       802.2 layer inside the VLAN layer */
+    is_802_2 = TRUE;
+
+    /* Don't throw an exception for this check (even a BoundsError) */
+    if (tvb_length_remaining(tvb, 4) >= 2) {
+	if (tvb_get_ntohs(tvb, 4) == 0xffff) {
+	    is_802_2 = FALSE;
+	}
+    }
+
+    dissect_802_3(encap_proto, is_802_2, tvb, 4, pinfo, tree, vlan_tree,
+		  hf_vlan_len, hf_vlan_trailer, 0);
+  } else {
+    ethertype(encap_proto, tvb, 4, pinfo, tree, vlan_tree,
+		       hf_vlan_etype, hf_vlan_trailer, 0);
+  }
+}
+
+void
+proto_register_vlan(void)
+{
+  static hf_register_info hf[] = {
+	{ &hf_vlan_priority, {
+		"Priority", "vlan.priority", FT_UINT16, BASE_DEC,
+		VALS(pri_vals), 0xE000, "Descriptions are recommendations from IEEE standard 802.1D-2004", HFILL }},
+	{ &hf_vlan_cfi, {
+		"CFI", "vlan.cfi", FT_UINT16, BASE_DEC,
+		VALS(cfi_vals), 0x1000, "Canonical Format Identifier", HFILL }},
+	{ &hf_vlan_id, {
+		"ID", "vlan.id", FT_UINT16, BASE_DEC,
+		NULL, 0x0FFF, "VLAN ID", HFILL }},
+	{ &hf_vlan_etype, {
+		"Type", "vlan.etype", FT_UINT16, BASE_HEX,
+		VALS(etype_vals), 0x0, "Ethertype", HFILL }},
+	{ &hf_vlan_len, {
+		"Length", "vlan.len", FT_UINT16, BASE_DEC,
+		NULL, 0x0, NULL, HFILL }},
+	{ &hf_vlan_trailer, {
+		"Trailer", "vlan.trailer", FT_BYTES, BASE_NONE,
+		NULL, 0x0, "VLAN Trailer", HFILL }}
+  };
+  static gint *ett[] = {
+	&ett_vlan
+  };
+  module_t *vlan_module;
+
+  proto_vlan = proto_register_protocol("802.1Q Virtual LAN", "VLAN", "vlan");
+  proto_register_field_array(proto_vlan, hf, array_length(hf));
+  proto_register_subtree_array(ett, array_length(ett));
+
+  vlan_module = prefs_register_protocol(proto_vlan, proto_reg_handoff_vlan);
+  prefs_register_bool_preference(vlan_module, "summary_in_tree",
+        "Show vlan summary in protocol tree",
+        "Whether the vlan summary line should be shown in the protocol tree",
+        &vlan_summary_in_tree);
+  prefs_register_uint_preference(vlan_module, "qinq_ethertype",
+        "802.1QinQ Ethertype (in hex)",
+        "The (hexadecimal) Ethertype used to indicate 802.1QinQ VLAN in VLAN tunneling.",
+        16, &q_in_q_ethertype);
+
+}
+
+void
+proto_reg_handoff_vlan(void)
+{
+  static gboolean prefs_initialized = FALSE;
+  static dissector_handle_t vlan_handle;
+  static unsigned int old_q_in_q_ethertype;
+
+  if (!prefs_initialized)
+  {
+    vlan_handle = create_dissector_handle(dissect_vlan, proto_vlan);
+    dissector_add("ethertype", ETHERTYPE_VLAN, vlan_handle);
+    prefs_initialized = TRUE;
+  }
+  else
+  {
+    dissector_delete("ethertype", old_q_in_q_ethertype, vlan_handle);
+  }
+
+  old_q_in_q_ethertype = q_in_q_ethertype;
+
+  dissector_add("ethertype", q_in_q_ethertype, vlan_handle);
+}
diff --git a/epan/dissectors/packet-vlan.h b/epan/dissectors/packet-vlan.h
new file mode 100644
index 0000000000..414771f14c
--- /dev/null
+++ b/epan/dissectors/packet-vlan.h
@@ -0,0 +1,29 @@
+/* packet-vlan.h
+ *
+ * $Id$
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.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.
+ */
+
+#ifndef __PACKET_VLAN_H__
+#define __PACKET_VLAN_H__
+
+void capture_vlan(const guchar *, int, int, packet_counts *);
+
+#endif
diff --git a/epan/prefs.c b/epan/prefs.c
index 2082109896..7b745723db 100644
--- a/epan/prefs.c
+++ b/epan/prefs.c
@@ -858,6 +858,14 @@ prefs_set_preference_obsolete(pref_t *pref)
 	return PREFS_SET_NO_SUCH_PREF;
 }
 
+/* Return the value assigned to the given uint preference. */
+guint prefs_get_uint_preference(pref_t *pref)
+{
+	if (pref && pref->type == PREF_UINT)
+		return *pref->varp.uint;
+	return 0;
+}
+
 /*
  * Call a callback function, with a specified argument, for each preference
  * in a given module.
@@ -1962,7 +1970,7 @@ try_convert_to_custom_column(gpointer *el_data)
         gint el;
         gchar *col_expr;
     } migrated_columns[] = {
-        { COL_COS_VALUE, "eth.vlan.pri" },
+        { COL_COS_VALUE, "vlan.priority" },
         { COL_CIRCUIT_ID, "iax2.call" },
         { COL_BSSGP_TLLI, "bssgp.tlli" },
         { COL_HPUX_SUBSYS, "nettl.subsys" },
@@ -2477,8 +2485,6 @@ set_pref(gchar *pref_name, gchar *value, void *private_data _U_,
          * We also renamed "dcp" to "dccp", "x.25" to "x25", "x411" to "p1"
 	 * and "nsip" to "gprs_ns".
 	 *
-	 * The vlan dissector was integrated into the Ethernet dissector.
-	 *
 	 * The SynOptics Network Management Protocol (SONMP) is now known by
 	 * its modern name, the Nortel Discovery Protocol (NDP).
 	 *