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

1 files changed, 219 insertions, 0 deletions

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);
+}