![Guy Harris](/assets/img/avatar_default.png)
A small cosmetic change to make it highlight the proper bytes in the hex pane. From Ronnie and me: use the length from the PPPoE header to set the length of the tvbuff we hand to the PPP dissector. svn path=/trunk/; revision=6462
310 lines
8.9 KiB
C
310 lines
8.9 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: packet-pppoe.c,v 1.25 2002/10/21 18:17:41 guy Exp $
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*
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* Ethereal - Network traffic analyzer
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* By Gerald Combs <gerald@ethereal.com>
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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/strutil.h>
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#include "etypes.h"
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static int proto_pppoed = -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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static dissector_handle_t ppp_handle;
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/* For lack of a better source, I made up the following defines. -jsj */
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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 gchar *
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pppoecode_to_str(guint8 codetype, const char *fmt) {
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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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return val_to_str(codetype, code_vals, fmt);
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}
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static gchar *
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pppoetag_to_str(guint16 tag_type, const char *fmt) {
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static const value_string code_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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return val_to_str(tag_type, code_vals, fmt);
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}
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static void
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dissect_pppoe_tags(tvbuff_t *tvb, int offset, proto_tree *tree, int payload_length) {
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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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ti = proto_tree_add_text(tree, tvb,offset,payload_length,"PPPoE Tags");
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pppoe_tree = proto_item_add_subtree(ti, ett_pppoed_tags);
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tagstart = offset;
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while(tagstart <= payload_length-2 ) {
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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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proto_tree_add_text(pppoe_tree, tvb,tagstart,4,
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"Tag: %s", pppoetag_to_str(poe_tag,"Unknown (0x%02x)"));
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switch(poe_tag) {
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case PPPOE_TAG_SVC_NAME:
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case PPPOE_TAG_AC_NAME:
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case PPPOE_TAG_SVC_ERR:
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case PPPOE_TAG_AC_ERR:
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case PPPOE_TAG_GENERIC_ERR:
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/* tag value should be interpreted as a utf-8 unterminated string.*/
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if(poe_tag_length > 0 ) {
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/* really should do some limit checking here. :( */
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proto_tree_add_text(pppoe_tree, tvb,tagstart+4,poe_tag_length,
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" String Data: %s",
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tvb_format_text(tvb, tagstart+4,poe_tag_length ));
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}
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break;
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default:
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if(poe_tag_length > 0 ) {
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proto_tree_add_text(pppoe_tree, tvb,tagstart+4,poe_tag_length,
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" Binary Data: (%d bytes)", poe_tag_length );
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}
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}
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if (poe_tag == PPPOE_TAG_EOL) break;
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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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static void
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dissect_pppoed(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) {
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guint8 pppoe_ver_type;
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guint8 pppoe_ver;
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guint8 pppoe_type;
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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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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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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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col_clear(pinfo->cinfo,COL_INFO);
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}
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/* Start Decoding Here. */
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pppoe_ver_type = tvb_get_guint8(tvb, 0);
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pppoe_ver = (pppoe_ver_type >> 4) & 0x0f;
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pppoe_type = pppoe_ver_type & 0x0f;
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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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col_add_fstr(pinfo->cinfo,COL_INFO,pppoecode_to_str(pppoe_code,"Unknown code (0x%02x)"));
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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);
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if (tree) {
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ti = proto_tree_add_item(tree, proto_pppoed, tvb,0,
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pppoe_length+6, FALSE);
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pppoe_tree = proto_item_add_subtree(ti, ett_pppoed);
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proto_tree_add_text(pppoe_tree, tvb,0,1,
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"Version: %u", pppoe_ver);
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proto_tree_add_text(pppoe_tree, tvb,0,1,
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"Type: %u", pppoe_type);
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proto_tree_add_text(pppoe_tree, tvb,1,1,
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"Code: %s", pppoecode_to_str(pppoe_code,"Unknown (0x%02x)"));
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proto_tree_add_text(pppoe_tree, tvb,2,2,
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"Session ID: %04x", pppoe_session_id);
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proto_tree_add_text(pppoe_tree, tvb,4,2,
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"Payload Length: %u", pppoe_length);
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}
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dissect_pppoe_tags(tvb,6,tree,6+pppoe_length);
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}
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void
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proto_register_pppoed(void)
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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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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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}
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void
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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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static void
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dissect_pppoes(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) {
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guint8 pppoe_ver_type;
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guint8 pppoe_ver;
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guint8 pppoe_type;
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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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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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col_clear(pinfo->cinfo,COL_INFO);
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}
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/* Start Decoding Here. */
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pppoe_ver_type = tvb_get_guint8(tvb, 0);
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pppoe_ver = (pppoe_ver_type >> 4) & 0x0f;
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pppoe_type = pppoe_ver_type & 0x0f;
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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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col_add_fstr(pinfo->cinfo,COL_INFO,
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pppoecode_to_str(pppoe_code,"Unknown code (0x%02x)"));
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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);
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if (tree) {
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ti = proto_tree_add_item(tree, proto_pppoes, tvb,0,
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6, FALSE);
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pppoe_tree = proto_item_add_subtree(ti, ett_pppoed);
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proto_tree_add_text(pppoe_tree, tvb,0,1,
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"Version: %u", pppoe_ver);
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proto_tree_add_text(pppoe_tree, tvb,0,1,
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"Type: %u", pppoe_type);
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proto_tree_add_text(pppoe_tree, tvb,1,1,
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"Code: %s", pppoecode_to_str(pppoe_code,"Unknown (0x%02x)"));
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proto_tree_add_text(pppoe_tree, tvb,2,2,
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"Session ID: %04x", pppoe_session_id);
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proto_tree_add_text(pppoe_tree, tvb,4,2,
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"Payload Length: %u", pppoe_length);
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}
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/* dissect_ppp is apparently done as a 'top level' dissector,
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* so this doesn't work:
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* dissect_ppp(pd,offset+6,pinfo->fd,tree);
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* Im gonna try fudging it.
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*/
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length = tvb_length_remaining(tvb, 6);
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reported_length = tvb_reported_length_remaining(tvb, 6);
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g_assert(length >= 0);
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g_assert(reported_length >= 0);
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if (length > reported_length)
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length = reported_length;
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if ((guint)length > pppoe_length)
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length = pppoe_length;
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if ((guint)reported_length > pppoe_length)
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reported_length = pppoe_length;
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next_tvb = tvb_new_subset(tvb,6,length,reported_length);
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call_dissector(ppp_handle,next_tvb,pinfo,tree);
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}
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void
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proto_register_pppoes(void)
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{
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proto_pppoes = proto_register_protocol("PPP-over-Ethernet Session",
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"PPPoES", "pppoes");
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}
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void
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proto_reg_handoff_pppoes(void)
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{
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dissector_handle_t pppoes_handle;
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pppoes_handle = create_dissector_handle(dissect_pppoes, proto_pppoes);
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dissector_add("ethertype", ETHERTYPE_PPPOES, pppoes_handle);
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/*
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* Get a handle for the PPP dissector.
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*/
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ppp_handle = find_dissector("ppp");
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}
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