498 lines
15 KiB
C
498 lines
15 KiB
C
/* packet-pppoe.c
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* Routines for PPP Over Ethernet (PPPoE) packet disassembly (RFC2516)
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*
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* $Id$
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*
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* Wireshark - Network traffic analyzer
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* By Gerald Combs <gerald@wireshark.org>
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* Copyright 1998 Gerald Combs
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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#ifdef HAVE_CONFIG_H
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# include "config.h"
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#endif
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#include <glib.h>
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#include <epan/packet.h>
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#include <epan/emem.h>
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#include <epan/strutil.h>
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#include <epan/etypes.h>
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#include <epan/prefs.h>
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static int proto_pppoed = -1;
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/* Common to session and discovery protocols */
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static gint hf_pppoe_version = -1;
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static gint hf_pppoe_type = -1;
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static gint hf_pppoe_code = -1;
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static gint hf_pppoe_session_id = -1;
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static gint hf_pppoe_payload_length = -1;
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/* Discovery protocol fields */
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static gint hf_pppoed_tags = -1;
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static gint hf_pppoed_tag = -1;
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static gint hf_pppoed_tag_length = -1;
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static gint hf_pppoed_tag_unknown_data = -1;
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static gint hf_pppoed_tag_service_name = -1;
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static gint hf_pppoed_tag_ac_name = -1;
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static gint hf_pppoed_tag_host_uniq = -1;
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static gint hf_pppoed_tag_ac_cookie = -1;
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static gint hf_pppoed_tag_vendor_id = -1;
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static gint hf_pppoed_tag_vendor_unspecified = -1;
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static gint hf_pppoed_tag_relay_session_id = -1;
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static gint hf_pppoed_tag_service_name_error = -1;
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static gint hf_pppoed_tag_ac_system_error = -1;
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static gint hf_pppoed_tag_generic_error = -1;
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static gint ett_pppoed = -1;
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static gint ett_pppoed_tags = -1;
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static int proto_pppoes = -1;
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/* Handle for calling for ppp dissector to handle session data */
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static dissector_handle_t ppp_handle;
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/* Preference for showing discovery tag values and lengths */
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static gboolean global_pppoe_show_tags_and_lengths = FALSE;
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#define PPPOE_CODE_SESSION 0x00
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#define PPPOE_CODE_PADO 0x7
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#define PPPOE_CODE_PADI 0x9
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#define PPPOE_CODE_PADR 0x19
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#define PPPOE_CODE_PADS 0x65
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#define PPPOE_CODE_PADT 0xa7
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#define PPPOE_TAG_EOL 0x0000
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#define PPPOE_TAG_SVC_NAME 0x0101
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#define PPPOE_TAG_AC_NAME 0x0102
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#define PPPOE_TAG_HOST_UNIQ 0x0103
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#define PPPOE_TAG_AC_COOKIE 0x0104
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#define PPPOE_TAG_VENDOR 0x0105
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#define PPPOE_TAG_RELAY_ID 0x0110
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#define PPPOE_TAG_SVC_ERR 0x0201
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#define PPPOE_TAG_AC_ERR 0x0202
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#define PPPOE_TAG_GENERIC_ERR 0x0203
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static const value_string code_vals[] = {
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{PPPOE_CODE_SESSION, "Session Data" },
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{PPPOE_CODE_PADO, "Active Discovery Offer (PADO)" },
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{PPPOE_CODE_PADI, "Active Discovery Initiation (PADI)" },
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{PPPOE_CODE_PADR, "Active Discovery Request (PADR)" },
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{PPPOE_CODE_PADS, "Active Discovery Session-confirmation (PADS)"},
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{PPPOE_CODE_PADT, "Active Discovery Terminate (PADT)" },
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{0, NULL }
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};
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static const value_string tag_vals[] = {
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{PPPOE_TAG_EOL, "End-Of-List" },
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{PPPOE_TAG_SVC_NAME, "Service-Name" },
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{PPPOE_TAG_AC_NAME, "AC-Name" },
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{PPPOE_TAG_HOST_UNIQ, "Host-Uniq" },
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{PPPOE_TAG_AC_COOKIE, "AC-Cookie" },
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{PPPOE_TAG_VENDOR, "Vendor-Specific" },
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{PPPOE_TAG_RELAY_ID, "Relay-Session-Id" },
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{PPPOE_TAG_SVC_ERR, "Service-Name-Error"},
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{PPPOE_TAG_AC_ERR, "AC-System-Error" },
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{PPPOE_TAG_GENERIC_ERR,"Generic-Error" },
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{0, NULL }
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};
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/* Forward declare discovery protocol handoff function */
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void proto_reg_handoff_pppoed(void);
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/* Dissect discovery protocol tags */
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static void
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dissect_pppoe_tags(tvbuff_t *tvb, packet_info *pinfo, int offset, proto_tree *tree,
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int payload_length)
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{
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guint16 poe_tag;
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guint16 poe_tag_length;
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int tagstart;
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proto_tree *pppoe_tree;
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proto_item *ti;
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/* Start Decoding Here. */
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if (tree)
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{
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/* Create tags subtree */
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ti = proto_tree_add_item(tree, hf_pppoed_tags, tvb, offset, payload_length-6, FALSE);
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pppoe_tree = proto_item_add_subtree(ti, ett_pppoed_tags);
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tagstart = offset;
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/* Loop until all data seen or End-Of-List tag found */
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while (tagstart <= payload_length-2 )
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{
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poe_tag = tvb_get_ntohs(tvb, tagstart);
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poe_tag_length = tvb_get_ntohs(tvb, tagstart + 2);
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/* Tag value and data length */
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if (global_pppoe_show_tags_and_lengths)
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{
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proto_tree_add_item(pppoe_tree, hf_pppoed_tag, tvb, tagstart, 2, FALSE);
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proto_tree_add_item(pppoe_tree, hf_pppoed_tag_length, tvb, tagstart+2, 2, FALSE);
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}
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/* Show tag data */
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switch (poe_tag)
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{
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case PPPOE_TAG_SVC_NAME:
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proto_tree_add_item(pppoe_tree, hf_pppoed_tag_service_name, tvb,
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tagstart+4, poe_tag_length, FALSE);
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break;
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case PPPOE_TAG_AC_NAME:
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proto_tree_add_item(pppoe_tree, hf_pppoed_tag_ac_name, tvb,
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tagstart+4, poe_tag_length, FALSE);
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/* Show AC-Name in info column */
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if (check_col(pinfo->cinfo,COL_INFO))
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{
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col_append_fstr(pinfo->cinfo, COL_INFO, " AC-Name='%s'",
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tvb_get_string(tvb, tagstart+4, poe_tag_length));
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}
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break;
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case PPPOE_TAG_HOST_UNIQ:
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proto_tree_add_item(pppoe_tree, hf_pppoed_tag_host_uniq, tvb,
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tagstart+4, poe_tag_length, FALSE);
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break;
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case PPPOE_TAG_AC_COOKIE:
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proto_tree_add_item(pppoe_tree, hf_pppoed_tag_ac_cookie, tvb,
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tagstart+4, poe_tag_length, FALSE);
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break;
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case PPPOE_TAG_VENDOR:
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if (poe_tag_length >= 4)
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{
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proto_tree_add_item(pppoe_tree, hf_pppoed_tag_vendor_id, tvb,
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tagstart+4, 4, FALSE);
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}
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if (poe_tag_length > 4)
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{
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proto_tree_add_item(pppoe_tree, hf_pppoed_tag_vendor_unspecified, tvb,
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tagstart+4+4, poe_tag_length-4, FALSE);
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}
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break;
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case PPPOE_TAG_RELAY_ID:
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proto_tree_add_item(pppoe_tree, hf_pppoed_tag_relay_session_id, tvb,
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tagstart+4, poe_tag_length, FALSE);
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break;
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/* These error tag values should be interpreted as a utf-8 unterminated
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strings. */
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case PPPOE_TAG_SVC_ERR:
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proto_tree_add_item(pppoe_tree, hf_pppoed_tag_service_name_error, tvb,
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tagstart+4, poe_tag_length, FALSE);
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break;
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case PPPOE_TAG_AC_ERR:
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proto_tree_add_item(pppoe_tree, hf_pppoed_tag_ac_system_error, tvb,
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tagstart+4, poe_tag_length, FALSE);
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break;
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case PPPOE_TAG_GENERIC_ERR:
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proto_tree_add_item(pppoe_tree, hf_pppoed_tag_generic_error, tvb,
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tagstart+4, poe_tag_length, FALSE);
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break;
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/* Get out if see end-of-list tag */
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case PPPOE_TAG_EOL:
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return;
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default:
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if (poe_tag_length > 0 )
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{
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/* Presumably unknown tag;
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show tag value if we didn't
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do it above */
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if (!global_pppoe_show_tags_and_lengths)
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proto_tree_add_item(pppoe_tree, hf_pppoed_tag, tvb, tagstart, 2, FALSE);
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proto_tree_add_item(pppoe_tree, hf_pppoed_tag_unknown_data, tvb,
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tagstart+4, poe_tag_length, FALSE);
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}
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}
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tagstart += (4 + poe_tag_length);
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}
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}
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}
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/* Discovery protocol, i.e. PPP session not yet established */
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static void dissect_pppoed(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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guint8 pppoe_code;
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guint16 pppoe_length;
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proto_tree *pppoe_tree;
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proto_item *ti;
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if (check_col(pinfo->cinfo, COL_PROTOCOL))
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{
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col_set_str(pinfo->cinfo,COL_PROTOCOL, "PPPoED");
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}
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if (check_col(pinfo->cinfo,COL_INFO))
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{
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col_clear(pinfo->cinfo,COL_INFO);
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}
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/* Start Decoding Here. */
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pppoe_code = tvb_get_guint8(tvb, 1);
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if (check_col(pinfo->cinfo,COL_INFO))
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{
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col_add_fstr(pinfo->cinfo,COL_INFO, val_to_str(pppoe_code, code_vals, "Unknown"));
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}
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/* Read length of payload */
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pppoe_length = tvb_get_ntohs(tvb, 4);
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if (tree)
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{
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ti = proto_tree_add_item(tree, proto_pppoed, tvb,0, pppoe_length+6, FALSE);
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pppoe_tree = proto_item_add_subtree(ti, ett_pppoed);
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/* Dissect fixed fields */
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proto_tree_add_item(pppoe_tree, hf_pppoe_version, tvb, 0, 1, FALSE);
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proto_tree_add_item(pppoe_tree, hf_pppoe_type, tvb, 0, 1, FALSE);
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proto_tree_add_item(pppoe_tree, hf_pppoe_code, tvb, 1, 1, FALSE);
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proto_tree_add_item(pppoe_tree, hf_pppoe_session_id, tvb, 2, 2, FALSE);
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proto_tree_add_item(pppoe_tree, hf_pppoe_payload_length, tvb, 4, 2, FALSE);
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}
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/* Now dissect any tags */
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if (pppoe_length > 0)
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{
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dissect_pppoe_tags(tvb, pinfo, 6, tree, 6+pppoe_length);
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}
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}
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void proto_register_pppoed(void)
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{
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static hf_register_info hf[] =
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{
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/* These fields common to discovery and session protocols */
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{ &hf_pppoe_version,
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{ "Version", "pppoe.version", FT_UINT8, BASE_DEC,
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NULL, 0xf0, "", HFILL
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}
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},
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{ &hf_pppoe_type,
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{ "Type", "pppoe.type", FT_UINT8, BASE_DEC,
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NULL, 0x0f, "", HFILL
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}
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},
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{ &hf_pppoe_code,
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{ "Code", "pppoe.code", FT_UINT8, BASE_HEX,
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VALS(code_vals), 0x0, "", HFILL
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}
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},
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{ &hf_pppoe_session_id,
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{ "Session ID", "pppoe.session_id", FT_UINT16, BASE_HEX,
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NULL, 0x0, "", HFILL
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}
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},
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{ &hf_pppoe_payload_length,
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{ "Payload Length", "pppoe.payload_length", FT_UINT16, BASE_DEC,
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NULL, 0x0, "", HFILL
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}
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},
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/* Discovery tag fields */
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{ &hf_pppoed_tags,
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{ "PPPoE Tags", "pppoed.tags", FT_NONE, BASE_NONE,
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NULL, 0x0, "", HFILL
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}
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},
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{ &hf_pppoed_tag,
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{ "Tag", "pppoed.tag", FT_UINT16, BASE_HEX,
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VALS(tag_vals), 0x0, "", HFILL
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}
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},
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{ &hf_pppoed_tag_length,
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{ "Tag Length", "pppoed.tag_length", FT_UINT16, BASE_DEC,
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NULL, 0x0, "", HFILL
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}
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},
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{ &hf_pppoed_tag_unknown_data,
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{ "Unknown Data", "pppoed.tag.unknown_data", FT_STRING, BASE_HEX,
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NULL, 0x0, "", HFILL
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}
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},
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{ &hf_pppoed_tag_service_name,
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{ "Service-Name", "pppoed.tags.service_name", FT_STRING, BASE_NONE,
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NULL, 0x0, "", HFILL
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}
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},
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{ &hf_pppoed_tag_ac_name,
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{ "AC-Name", "pppoed.tags.ac_name", FT_STRING, BASE_NONE,
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NULL, 0x0, "", HFILL
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}
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},
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{ &hf_pppoed_tag_host_uniq,
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{ "Host-Uniq", "pppoed.tags.host_uniq", FT_BYTES, BASE_NONE,
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NULL, 0x0, "", HFILL
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}
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},
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{ &hf_pppoed_tag_ac_cookie,
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{ "AC-Cookie", "pppoed.tags.ac_cookie", FT_BYTES, BASE_NONE,
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NULL, 0x0, "", HFILL
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}
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},
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{ &hf_pppoed_tag_vendor_id,
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{ "Vendor id", "pppoed.tags.vendor_id", FT_UINT32, BASE_HEX,
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NULL, 0x0, "", HFILL
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}
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},
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{ &hf_pppoed_tag_vendor_unspecified,
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{ "Vendor unspecified", "pppoed.tags.vendor_unspecified", FT_BYTES, BASE_HEX,
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NULL, 0x0, "", HFILL
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}
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},
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{ &hf_pppoed_tag_relay_session_id,
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{ "Relay-Session-Id", "pppoed.tags.relay_session_id", FT_BYTES, BASE_NONE,
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NULL, 0x0, "", HFILL
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}
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},
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{ &hf_pppoed_tag_service_name_error,
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{ "Service-Name-Error", "pppoed.tags.service_name_error", FT_STRING, BASE_NONE,
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NULL, 0x0, "", HFILL
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}
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},
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{ &hf_pppoed_tag_ac_system_error,
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{ "AC-System-Error", "pppoed.tags.ac_system_error", FT_STRING, BASE_NONE,
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NULL, 0x0, "", HFILL
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}
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},
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{ &hf_pppoed_tag_generic_error,
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{ "Generic-Error", "pppoed.tags.generic_error", FT_STRING, BASE_NONE,
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NULL, 0x0, "", HFILL
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}
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},
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};
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static gint *ett[] = {
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&ett_pppoed,
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&ett_pppoed_tags,
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};
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module_t *pppoed_module;
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/* Register protocol and fields */
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proto_pppoed = proto_register_protocol("PPP-over-Ethernet Discovery",
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"PPPoED", "pppoed");
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proto_register_subtree_array(ett, array_length(ett));
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proto_register_field_array(proto_pppoed, hf, array_length(hf));
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/* Preference setting */
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pppoed_module = prefs_register_protocol(proto_pppoed, proto_reg_handoff_pppoed);
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prefs_register_bool_preference(pppoed_module, "show_tags_and_lengths",
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"Show tag values and lengths",
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"Show values of tags and lengths of data fields",
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&global_pppoe_show_tags_and_lengths);
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}
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void proto_reg_handoff_pppoed(void)
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{
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dissector_handle_t pppoed_handle;
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pppoed_handle = create_dissector_handle(dissect_pppoed, proto_pppoed);
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dissector_add("ethertype", ETHERTYPE_PPPOED, pppoed_handle);
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}
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/* Session protocol, i.e. PPP session established */
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static void dissect_pppoes(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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guint8 pppoe_code;
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guint16 pppoe_session_id;
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guint16 pppoe_length;
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gint length, reported_length;
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proto_tree *pppoe_tree;
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proto_item *ti;
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tvbuff_t *next_tvb;
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if (check_col(pinfo->cinfo, COL_PROTOCOL))
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{
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col_set_str(pinfo->cinfo,COL_PROTOCOL, "PPPoES");
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}
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if (check_col(pinfo->cinfo,COL_INFO))
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{
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col_clear(pinfo->cinfo,COL_INFO);
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}
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/* Start Decoding Here. */
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pppoe_code = tvb_get_guint8(tvb, 1);
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if (check_col(pinfo->cinfo,COL_INFO))
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{
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col_add_fstr(pinfo->cinfo, COL_INFO,
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val_to_str(pppoe_code, code_vals, "Unknown"));
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}
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pppoe_session_id = tvb_get_ntohs(tvb, 2);
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pppoe_length = tvb_get_ntohs(tvb, 4);
|
|
|
|
if (tree)
|
|
{
|
|
ti = proto_tree_add_item(tree, proto_pppoes, tvb, 0, 6, FALSE);
|
|
pppoe_tree = proto_item_add_subtree(ti, ett_pppoed);
|
|
|
|
proto_tree_add_item(pppoe_tree, hf_pppoe_version, tvb, 0, 1, FALSE);
|
|
proto_tree_add_item(pppoe_tree, hf_pppoe_type, tvb, 0, 1, FALSE);
|
|
proto_tree_add_item(pppoe_tree, hf_pppoe_code, tvb, 1, 1, FALSE);
|
|
proto_tree_add_item(pppoe_tree, hf_pppoe_session_id, tvb, 2, 2, FALSE);
|
|
proto_tree_add_item(pppoe_tree, hf_pppoe_payload_length, tvb, 4, 2, FALSE);
|
|
}
|
|
|
|
/* dissect_ppp is apparently done as a 'top level' dissector,
|
|
* so this doesn't work:
|
|
* dissect_ppp(pd,offset+6,pinfo->fd,tree);
|
|
* Im gonna try fudging it.
|
|
*/
|
|
length = tvb_length_remaining(tvb, 6);
|
|
reported_length = tvb_reported_length_remaining(tvb, 6);
|
|
DISSECTOR_ASSERT(length >= 0);
|
|
DISSECTOR_ASSERT(reported_length >= 0);
|
|
if (length > reported_length)
|
|
length = reported_length;
|
|
if ((guint)length > pppoe_length)
|
|
length = pppoe_length;
|
|
if ((guint)reported_length > pppoe_length)
|
|
reported_length = pppoe_length;
|
|
next_tvb = tvb_new_subset(tvb,6,length,reported_length);
|
|
call_dissector(ppp_handle,next_tvb,pinfo,tree);
|
|
}
|
|
|
|
void proto_register_pppoes(void)
|
|
{
|
|
/* Register protocol */
|
|
proto_pppoes = proto_register_protocol("PPP-over-Ethernet Session", "PPPoES", "pppoes");
|
|
}
|
|
|
|
void proto_reg_handoff_pppoes(void)
|
|
{
|
|
dissector_handle_t pppoes_handle =
|
|
create_dissector_handle(dissect_pppoes, proto_pppoes);
|
|
dissector_add("ethertype", ETHERTYPE_PPPOES, pppoes_handle);
|
|
|
|
/* Get a handle for the PPP dissector */
|
|
ppp_handle = find_dissector("ppp");
|
|
}
|