/* packet-pppoe.c
 * Routines for PPP Over Ethernet (PPPoE) packet disassembly (RFC2516)
 * Up to date with http://www.iana.org/assignments/pppoe-parameters (2008-04-30)
 *
 * $Id: packet-pppoe.c 47390 2013-01-31 18:31:28Z wmeier $
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "config.h"

#include <glib.h>
#include <epan/packet.h>
#include <epan/strutil.h>
#include <epan/etypes.h>
#include <epan/prefs.h>
#include <epan/expert.h>
#include <epan/ppptypes.h>

static int proto_pppoed = -1;

/* Common to session and discovery protocols */
static gint hf_pppoe_version = -1;
static gint hf_pppoe_type = -1;
static gint hf_pppoe_code = -1;
static gint hf_pppoe_session_id = -1;
static gint hf_pppoe_payload_length = -1;

/* Discovery protocol fields */
static gint hf_pppoed_tags = -1;
static gint hf_pppoed_tag = -1;
static gint hf_pppoed_tag_length = -1;
static gint hf_pppoed_tag_length_8 = -1;
static gint hf_pppoed_tag_unknown_data = -1;
static gint hf_pppoed_tag_service_name = -1;
static gint hf_pppoed_tag_ac_name = -1;
static gint hf_pppoed_tag_host_uniq = -1;
static gint hf_pppoed_tag_ac_cookie = -1;
static gint hf_pppoed_tag_vendor_id = -1;
static gint hf_pppoed_tag_vendor_unspecified = -1;
static gint hf_pppoed_tag_vspec_tags = -1;
static gint hf_pppoed_tag_vspec_tag = -1;
static gint hf_pppoed_tag_vspec_circuit_id = -1;
static gint hf_pppoed_tag_vspec_remote_id = -1;
static gint hf_pppoed_tag_vspec_act_data_rate_up = -1;
static gint hf_pppoed_tag_vspec_act_data_rate_down = -1;
static gint hf_pppoed_tag_vspec_min_data_rate_up = -1;
static gint hf_pppoed_tag_vspec_min_data_rate_down = -1;
static gint hf_pppoed_tag_vspec_attainable_data_rate_up = -1;
static gint hf_pppoed_tag_vspec_attainable_data_rate_down = -1;
static gint hf_pppoed_tag_vspec_max_data_rate_up = -1;
static gint hf_pppoed_tag_vspec_max_data_rate_down = -1;
static gint hf_pppoed_tag_vspec_min_data_rate_up_lp = -1;
static gint hf_pppoed_tag_vspec_min_data_rate_down_lp = -1;
static gint hf_pppoed_tag_vspec_max_int_delay_up = -1;
static gint hf_pppoed_tag_vspec_act_int_delay_up = -1;
static gint hf_pppoed_tag_vspec_max_int_delay_down = -1;
static gint hf_pppoed_tag_vspec_act_int_delay_down = -1;
static gint hf_pppoed_tag_vspec_access_loop_encapsulation = -1;
static gint hf_pppoed_tag_vspec_access_loop_encap_data_link = -1;
static gint hf_pppoed_tag_vspec_access_loop_encap_encap_1 = -1;
static gint hf_pppoed_tag_vspec_access_loop_encap_encap_2 = -1;
static gint hf_pppoed_tag_credits = -1;
static gint hf_pppoed_tag_credits_fcn = -1;
static gint hf_pppoed_tag_credits_bcn = -1;
static gint hf_pppoed_tag_metrics = -1;
static gint hf_pppoed_tag_metrics_r = -1;
static gint hf_pppoed_tag_metrics_rlq = -1;
static gint hf_pppoed_tag_metrics_resource = -1;
static gint hf_pppoed_tag_metrics_latency = -1;
static gint hf_pppoed_tag_metrics_curr_drate = -1;
static gint hf_pppoed_tag_metrics_max_drate = -1;
static gint hf_pppoed_tag_mdr_units = -1;
static gint hf_pppoed_tag_cdr_units = -1;
static gint hf_pppoed_tag_seq_num = -1;
static gint hf_pppoed_tag_cred_scale = -1;
static gint hf_pppoed_tag_relay_session_id = -1;
static gint hf_pppoed_tag_hurl = -1;
static gint hf_pppoed_tag_motm = -1;
static gint hf_pppoed_tag_max_payload = -1;
static gint hf_pppoed_tag_ip_route_add = -1;
static gint hf_pppoed_tag_service_name_error = -1;
static gint hf_pppoed_tag_ac_system_error = -1;
static gint hf_pppoed_tag_generic_error = -1;

/* Session protocol fields */
static gint hf_pppoes_tags = -1;
/* static gint hf_pppoes_tag = -1; */
/* static gint hf_pppoes_tag_credits = -1; */
static gint hf_pppoes_tag_credits_fcn = -1;
static gint hf_pppoes_tag_credits_bcn = -1;

/* Session protocol fields */

static gint ett_pppoed = -1;
static gint ett_pppoed_tags = -1;
static gint ett_pppoed_tag_vspec_dslf_access_loop_encaps = -1;

static int proto_pppoes = -1;

static gint ett_pppoes = -1;
static gint ett_pppoes_tags = -1;

/* PPPoE parent fields */

static int proto_pppoe = -1;
static gint ett_pppoe = -1;


/* Handle for calling for ppp dissector to handle session data */
static dissector_handle_t ppp_handle;


/* Preference for showing discovery tag values and lengths */
static gboolean global_pppoe_show_tags_and_lengths = FALSE;


#define PPPOE_CODE_SESSION    0x00
#define PPPOE_CODE_PADO       0x07
#define PPPOE_CODE_PADI       0x09
#define PPPOE_CODE_PADG       0x0a
#define PPPOE_CODE_PADC       0x0b
#define PPPOE_CODE_PADQ       0x0c
#define PPPOE_CODE_PADR       0x19
#define PPPOE_CODE_PADS       0x65
#define PPPOE_CODE_PADT       0xa7
#define PPPOE_CODE_PADM       0xd3
#define PPPOE_CODE_PADN       0xd4

#define PPPOE_TAG_EOL         0x0000
#define PPPOE_TAG_SVC_NAME    0x0101
#define PPPOE_TAG_AC_NAME     0x0102
#define PPPOE_TAG_HOST_UNIQ   0x0103
#define PPPOE_TAG_AC_COOKIE   0x0104
#define PPPOE_TAG_VENDOR      0x0105
#define PPPOE_TAG_CREDITS     0x0106
#define PPPOE_TAG_METRICS     0x0107
#define PPPOE_TAG_SEQ_NUM     0x0108
#define PPPOE_TAG_CRED_SCALE  0x0109
#define PPPOE_TAG_RELAY_ID    0x0110
#define PPPOE_TAG_HURL        0x0111
#define PPPOE_TAG_MOTM        0x0112
#define PPPOE_TAG_MAX_PAYLD   0x0120
#define PPPOE_TAG_IP_RT_ADD   0x0121
#define PPPOE_TAG_SVC_ERR     0x0201
#define PPPOE_TAG_AC_ERR      0x0202
#define PPPOE_TAG_GENERIC_ERR 0x0203

#define PPPOE_VENDOR_ID_DSLF  3561

#define PPPOE_TAG_VSPEC_DSLF_CIRCUIT_ID                0x01
#define PPPOE_TAG_VSPEC_DSLF_REMOTE_ID                 0x02
#define PPPOE_TAG_VSPEC_DSLF_ACT_DATA_RATE_UP          0x81
#define PPPOE_TAG_VSPEC_DSLF_ACT_DATA_RATE_DOWN        0x82
#define PPPOE_TAG_VSPEC_DSLF_MIN_DATA_RATE_UP          0x83
#define PPPOE_TAG_VSPEC_DSLF_MIN_DATA_RATE_DOWN        0x84
#define PPPOE_TAG_VSPEC_DSLF_ATTAINABLE_DATA_RATE_UP   0x85
#define PPPOE_TAG_VSPEC_DSLF_ATTAINABLE_DATA_RATE_DOWN 0x86
#define PPPOE_TAG_VSPEC_DSLF_MAX_DATA_RATE_UP          0x87
#define PPPOE_TAG_VSPEC_DSLF_MAX_DATA_RATE_DOWN        0x88
#define PPPOE_TAG_VSPEC_DSLF_MIN_DATA_RATE_UP_LP       0x89
#define PPPOE_TAG_VSPEC_DSLF_MIN_DATA_RATE_DOWN_LP     0x8a
#define PPPOE_TAG_VSPEC_DSLF_MAX_INT_DELAY_UP          0x8b
#define PPPOE_TAG_VSPEC_DSLF_ACT_INT_DELAY_UP          0x8c
#define PPPOE_TAG_VSPEC_DSLF_MAX_INT_DELAY_DOWN        0x8d
#define PPPOE_TAG_VSPEC_DSLF_ACT_INT_DELAY_DOWN        0x8e
#define PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAPSULATION 0x90

#define PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAP_DATA_LINK_ATM 0x00
#define PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAP_DATA_LINK_ETH 0x01

#define PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAP_ENCAPS_1_NA               0x00
#define PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAP_ENCAPS_1_UNTAGGED_ETH     0x01
#define PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAP_ENCAPS_1_SINLE_TAGGED_ETH 0x02

#define PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAP_ENCAPS_2_NA                             0x00
#define PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAP_ENCAPS_2_PPPOA_LLC                      0x01
#define PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAP_ENCAPS_2_PPPOA_NULL                     0x02
#define PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAP_ENCAPS_2_IPOA_LLC                       0x03
#define PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAP_ENCAPS_2_IPOA_NULL                      0x04
#define PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAP_ENCAPS_2_ETH_OVER_AAL5_LLC_WITH_FCS     0x05
#define PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAP_ENCAPS_2_ETH_OVER_AAL5_LLC_WITHOUT_FCS  0x06
#define PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAP_ENCAPS_2_ETH_OVER_AAL5_NULL_WITH_FCS    0x07
#define PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAP_ENCAPS_2_ETH_OVER_AAL5_NULL_WITHOUT_FCS 0x08

#define PPPOE_CDR_MASK        0x06
#define PPPOE_MDR_MASK        0x18
#define PPPOE_RCV_ONLY_MASK   0x01

#define PPPOE_SCALE_KBPS      0x00
#define PPPOE_SCALE_MBPS      0x01
#define PPPOE_SCALE_GBPS      0x02
#define PPPOE_SCALE_TBPS      0x03


static const value_string code_vals[] = {
		{PPPOE_CODE_SESSION, "Session Data"                             },
		{PPPOE_CODE_PADO, "Active Discovery Offer (PADO)"               },
		{PPPOE_CODE_PADI, "Active Discovery Initiation (PADI)"          },
		{PPPOE_CODE_PADG, "Active Discovery Session-Grant (PADG)"       },
		{PPPOE_CODE_PADC, "Active Discovery Session-Credit Resp.(PADC)" },
		{PPPOE_CODE_PADQ, "Active Discovery Quality (PADQ)"             },
		{PPPOE_CODE_PADR, "Active Discovery Request (PADR)"             },
		{PPPOE_CODE_PADS, "Active Discovery Session-confirmation (PADS)"},
		{PPPOE_CODE_PADT, "Active Discovery Terminate (PADT)"           },
		{PPPOE_CODE_PADM, "Active Discovery Message (PADM)"             },
		{PPPOE_CODE_PADN, "Active Discovery Network (PADN)"             },
		{0,               NULL                                          }
};


static const value_string tag_vals[] = {
		{PPPOE_TAG_EOL,        "End-Of-List"       },
		{PPPOE_TAG_SVC_NAME,   "Service-Name"      },
		{PPPOE_TAG_AC_NAME,    "AC-Name"           },
		{PPPOE_TAG_HOST_UNIQ,  "Host-Uniq"         },
		{PPPOE_TAG_AC_COOKIE,  "AC-Cookie"         },
		{PPPOE_TAG_VENDOR,     "Vendor-Specific"   },
		{PPPOE_TAG_CREDITS,    "Credits"           },
		{PPPOE_TAG_METRICS,    "Metrics"           },
		{PPPOE_TAG_SEQ_NUM,    "Sequence Number"    },
		{PPPOE_TAG_CRED_SCALE, "Credit Scale Factor"},
		{PPPOE_TAG_RELAY_ID,   "Relay-Session-Id"  },
		{PPPOE_TAG_HURL,       "HURL"              },
		{PPPOE_TAG_MOTM,       "MOTM"              },
		{PPPOE_TAG_MAX_PAYLD,  "PPP-Max-Payload"   },
		{PPPOE_TAG_IP_RT_ADD,  "IP Route Add"      },
		{PPPOE_TAG_SVC_ERR,    "Service-Name-Error"},
		{PPPOE_TAG_AC_ERR,     "AC-System-Error"   },
		{PPPOE_TAG_GENERIC_ERR,"Generic-Error"     },
		{0,                    NULL                }
};

static const value_string vspec_tag_vals[] = {
		{PPPOE_TAG_VSPEC_DSLF_CIRCUIT_ID,                "Circuit-ID"                    },
		{PPPOE_TAG_VSPEC_DSLF_REMOTE_ID,                 "Remote-ID"                     },
		{PPPOE_TAG_VSPEC_DSLF_ACT_DATA_RATE_UP,          "Actual-Data-Rate-Up"           },
		{PPPOE_TAG_VSPEC_DSLF_ACT_DATA_RATE_DOWN,        "Actual-Data-Rate-Down"         },
		{PPPOE_TAG_VSPEC_DSLF_MIN_DATA_RATE_UP,          "Min-Data-Rate-Up"              },
		{PPPOE_TAG_VSPEC_DSLF_MIN_DATA_RATE_DOWN,        "Min-Data-Rate-Down"            },
		{PPPOE_TAG_VSPEC_DSLF_ATTAINABLE_DATA_RATE_UP,   "Attainable-Data-Rate-Up"       },
		{PPPOE_TAG_VSPEC_DSLF_ATTAINABLE_DATA_RATE_DOWN, "Attainable-Data-Rate-Down"     },
		{PPPOE_TAG_VSPEC_DSLF_MAX_DATA_RATE_UP,          "Max-Data-Rate-Up"              },
		{PPPOE_TAG_VSPEC_DSLF_MAX_DATA_RATE_DOWN,        "Max-Data-Rate-Down"            },
		{PPPOE_TAG_VSPEC_DSLF_MIN_DATA_RATE_UP_LP,       "Min-Data-Rate-Up-Low-Power"    },
		{PPPOE_TAG_VSPEC_DSLF_MIN_DATA_RATE_DOWN_LP,     "Min-Data-Rate-Down-Low-Power"  },
		{PPPOE_TAG_VSPEC_DSLF_MAX_INT_DELAY_UP,          "Max-Interleaving-Delay-Up"     },
		{PPPOE_TAG_VSPEC_DSLF_ACT_INT_DELAY_UP,          "Actual-Interleaving-Delay-Up"  },
		{PPPOE_TAG_VSPEC_DSLF_MAX_INT_DELAY_DOWN,        "Max-Interleaving-Delay-Down"   },
		{PPPOE_TAG_VSPEC_DSLF_ACT_INT_DELAY_DOWN,        "Actual-Interleaving-Delay-Down"},
		{PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAPSULATION, "Access-Loop-Encapsulation"     },
		{0,                                              NULL                            }
};

static const value_string vspec_tag_dslf_access_loop_encap_data_link_vals[] = {
		{PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAP_DATA_LINK_ATM, "ATM AAL5"},
		{PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAP_DATA_LINK_ETH, "Ethernet"},
		{0,                                                     NULL     }
};

static const value_string vspec_tag_dslf_access_loop_encap_encap_1_vals[] = {
		{PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAP_ENCAPS_1_NA,               "NA"                    },
		{PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAP_ENCAPS_1_UNTAGGED_ETH,     "Untagged Ethernet"     },
		{PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAP_ENCAPS_1_SINLE_TAGGED_ETH, "Single-tagged Ethernet"},
		{0,                                                     NULL                               }
};

static const value_string vspec_tag_dslf_access_loop_encap_encap_2_vals[] = {
		{PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAP_ENCAPS_2_NA,                            "NA"                             },
		{PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAP_ENCAPS_2_PPPOA_LLC,                     "PPPoA LLC"                      },
		{PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAP_ENCAPS_2_PPPOA_NULL,                    "PPPoA Null"                     },
		{PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAP_ENCAPS_2_IPOA_LLC,                      "IPoA LLC"                       },
		{PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAP_ENCAPS_2_IPOA_NULL,                     "IPoA Null"                      },
		{PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAP_ENCAPS_2_ETH_OVER_AAL5_LLC_WITH_FCS,    "Ethernet over AAL5 LLC w FCS"   },
		{PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAP_ENCAPS_2_ETH_OVER_AAL5_LLC_WITHOUT_FCS, "Ethernet over AAL5 LLC w/o FCS" },
		{PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAP_ENCAPS_2_ETH_OVER_AAL5_NULL_WITH_FCS,   "Ethernet over AAL5 Null w FCS"  },
		{PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAP_ENCAPS_2_ETH_OVER_AAL5_NULL_WITHOUT_FCS,"Ethernet over AAL5 Null w/o FCS"},
		{0,                                                     NULL                               }
};

static const value_string datarate_scale_vals[] = {
                {PPPOE_SCALE_KBPS,	"kilobits per second"},
                {PPPOE_SCALE_MBPS,	"megabits per second"},
                {PPPOE_SCALE_GBPS,	"gigabits per second"},
                {PPPOE_SCALE_TBPS,	"terabits per second"},
		{0,			NULL                 }
};


#define CASE_VSPEC_DSLF_TAG_UINT(tag_name, relation, length, hf_var) case tag_name: \
		if (!(poe_tag_length relation length)) { \
			expert_add_info_format(pinfo, pppoe_tree, PI_MALFORMED, PI_WARN, "%s: Wrong length: %u (expected %s %d)", \
					val_to_str_const(poe_tag, vspec_tag_vals, "Unknown"), poe_tag_length, #relation, length); \
		} else { \
			proto_tree_add_item(pppoe_tree, hf_var, tvb, \
				tagstart+2, poe_tag_length, ENC_BIG_ENDIAN); \
		} \
	break;

#define CASE_VSPEC_DSLF_TAG_STRING(tag_name, relation, length, hf_var) case tag_name: \
		if (!(poe_tag_length relation length)) { \
			expert_add_info_format(pinfo, pppoe_tree, PI_MALFORMED, PI_WARN, "%s: Wrong length: %u (expected %s %d)", \
					val_to_str_const(poe_tag, vspec_tag_vals, "Unknown"), poe_tag_length, #relation, length); \
		} else { \
			proto_tree_add_item(pppoe_tree, hf_var, tvb, \
				tagstart+2, poe_tag_length, ENC_ASCII|ENC_NA); \
		} \
	break;

/* Dissect Vendor-Specific Tags introduced by the DSLF */
static void
dissect_pppoe_subtags_dslf(tvbuff_t *tvb, packet_info *pinfo _U_, int offset, proto_tree *tree,
                   int payload_length)
{
	guint8 poe_tag;
	guint8 poe_tag_length;
	int tagstart;

	proto_tree  *pppoe_tree, *ti, *encaps_tree;

	/* Start Decoding Here. */
	if (tree)
	{
		/* Create tags subtree */
		ti = proto_tree_add_item(tree, hf_pppoed_tag_vspec_tags, tvb, offset, payload_length, ENC_NA);
		pppoe_tree = proto_item_add_subtree(ti, ett_pppoed_tags);

		tagstart = offset;

		/* Loop until all data seen or End-Of-List tag found */
		while (tagstart <= offset + payload_length-2)
		{
			poe_tag = tvb_get_guint8(tvb, tagstart);
			poe_tag_length = tvb_get_guint8(tvb, tagstart + 1);

			/* Tag value and data length */
			if (global_pppoe_show_tags_and_lengths)
			{
				proto_tree_add_item(pppoe_tree, hf_pppoed_tag_vspec_tag, tvb, tagstart, 1, ENC_BIG_ENDIAN);
				proto_tree_add_item(pppoe_tree, hf_pppoed_tag_length_8, tvb, tagstart+1, 1, ENC_BIG_ENDIAN);
			}

			/* Show tag data */
			switch (poe_tag)
			{
				CASE_VSPEC_DSLF_TAG_STRING(PPPOE_TAG_VSPEC_DSLF_CIRCUIT_ID, <=, 63,
						hf_pppoed_tag_vspec_circuit_id)
				CASE_VSPEC_DSLF_TAG_STRING(PPPOE_TAG_VSPEC_DSLF_REMOTE_ID, <=, 63,
						hf_pppoed_tag_vspec_remote_id)
				CASE_VSPEC_DSLF_TAG_UINT(PPPOE_TAG_VSPEC_DSLF_ACT_DATA_RATE_UP, ==, 4,
						hf_pppoed_tag_vspec_act_data_rate_up)
				CASE_VSPEC_DSLF_TAG_UINT(PPPOE_TAG_VSPEC_DSLF_ACT_DATA_RATE_DOWN, ==, 4,
						hf_pppoed_tag_vspec_act_data_rate_down)
				CASE_VSPEC_DSLF_TAG_UINT(PPPOE_TAG_VSPEC_DSLF_MIN_DATA_RATE_UP, ==, 4,
						hf_pppoed_tag_vspec_min_data_rate_up)
				CASE_VSPEC_DSLF_TAG_UINT(PPPOE_TAG_VSPEC_DSLF_MIN_DATA_RATE_DOWN, ==, 4,
						hf_pppoed_tag_vspec_min_data_rate_down)
				CASE_VSPEC_DSLF_TAG_UINT(PPPOE_TAG_VSPEC_DSLF_ATTAINABLE_DATA_RATE_UP, ==, 4,
						hf_pppoed_tag_vspec_attainable_data_rate_up)
				CASE_VSPEC_DSLF_TAG_UINT(PPPOE_TAG_VSPEC_DSLF_ATTAINABLE_DATA_RATE_DOWN, ==, 4,
						hf_pppoed_tag_vspec_attainable_data_rate_down)
				CASE_VSPEC_DSLF_TAG_UINT(PPPOE_TAG_VSPEC_DSLF_MAX_DATA_RATE_UP, ==, 4,
						hf_pppoed_tag_vspec_max_data_rate_up)
				CASE_VSPEC_DSLF_TAG_UINT(PPPOE_TAG_VSPEC_DSLF_MAX_DATA_RATE_DOWN, ==, 4,
						hf_pppoed_tag_vspec_max_data_rate_down)
				CASE_VSPEC_DSLF_TAG_UINT(PPPOE_TAG_VSPEC_DSLF_MIN_DATA_RATE_UP_LP, ==, 4,
						hf_pppoed_tag_vspec_min_data_rate_up_lp)
				CASE_VSPEC_DSLF_TAG_UINT(PPPOE_TAG_VSPEC_DSLF_MIN_DATA_RATE_DOWN_LP, ==, 4,
						hf_pppoed_tag_vspec_min_data_rate_down_lp)
				CASE_VSPEC_DSLF_TAG_UINT(PPPOE_TAG_VSPEC_DSLF_MAX_INT_DELAY_UP, ==, 4,
						hf_pppoed_tag_vspec_max_int_delay_up)
				CASE_VSPEC_DSLF_TAG_UINT(PPPOE_TAG_VSPEC_DSLF_ACT_INT_DELAY_UP, ==, 4,
						hf_pppoed_tag_vspec_act_int_delay_up)
				CASE_VSPEC_DSLF_TAG_UINT(PPPOE_TAG_VSPEC_DSLF_MAX_INT_DELAY_DOWN, ==, 4,
						hf_pppoed_tag_vspec_max_int_delay_down)
				CASE_VSPEC_DSLF_TAG_UINT(PPPOE_TAG_VSPEC_DSLF_ACT_INT_DELAY_DOWN, ==, 4,
						hf_pppoed_tag_vspec_act_int_delay_down)
				case PPPOE_TAG_VSPEC_DSLF_ACCESS_LOOP_ENCAPSULATION:
					ti = proto_tree_add_item(pppoe_tree, hf_pppoed_tag_vspec_access_loop_encapsulation, tvb,
							tagstart+2, 3, ENC_NA);
					if (poe_tag_length != 3) {
						expert_add_info_format(pinfo, ti, PI_MALFORMED, PI_WARN,
								"%s: Wrong length: %u (expected 3)",
								val_to_str_const(poe_tag, vspec_tag_vals, "Unknown"), poe_tag_length);
					}
					encaps_tree = proto_item_add_subtree(ti, ett_pppoed_tag_vspec_dslf_access_loop_encaps);
					proto_tree_add_item(encaps_tree, hf_pppoed_tag_vspec_access_loop_encap_data_link,
							tvb, tagstart+2, 1, ENC_BIG_ENDIAN);
					proto_tree_add_item(encaps_tree, hf_pppoed_tag_vspec_access_loop_encap_encap_1,
							tvb, tagstart+3, 1, ENC_BIG_ENDIAN);
					proto_tree_add_item(encaps_tree, hf_pppoed_tag_vspec_access_loop_encap_encap_2,
							tvb, tagstart+4, 1, ENC_BIG_ENDIAN);

					break;
				default:
					if (poe_tag_length > 0 )
					{
						/* Presumably unknown tag;
						   show tag value if we didn't do it above */
						if (!global_pppoe_show_tags_and_lengths)
						{
							proto_tree_add_item(pppoe_tree, hf_pppoed_tag, tvb, tagstart, 1, ENC_BIG_ENDIAN);
							proto_tree_add_item(pppoe_tree, hf_pppoed_tag_length_8, tvb, tagstart+1, 1, ENC_BIG_ENDIAN);
						}
						proto_tree_add_item(pppoe_tree, hf_pppoed_tag_unknown_data, tvb,
								tagstart+1, poe_tag_length, ENC_NA);
					}
			}

			tagstart += (2 + poe_tag_length);
		}
	}
}


/* Dissect discovery protocol tags */
static void
dissect_pppoe_tags(tvbuff_t *tvb, packet_info *pinfo, int offset, proto_tree *tree,
                   int payload_length)
{
	guint16 poe_tag;
	guint16 poe_tag_length;
	int tagstart;
        guint16 poe_rsv = 0;

	proto_tree  *pppoe_tree;
	proto_item  *ti;
	proto_item  *pppoe_tree_tag_length_item = NULL;
	proto_item  *item;

	/* Start Decoding Here. */
	if (tree)
	{
		/* Create tags subtree */
		ti = proto_tree_add_item(tree, hf_pppoed_tags, tvb, offset, payload_length-6, ENC_NA);
		pppoe_tree = proto_item_add_subtree(ti, ett_pppoed_tags);

		tagstart = offset;

		/* Loop until all data seen or End-Of-List tag found */
		while (tagstart <= payload_length-2)
		{
			poe_tag = tvb_get_ntohs(tvb, tagstart);
			poe_tag_length = tvb_get_ntohs(tvb, tagstart + 2);

			/* Tag value and data length */
			if (global_pppoe_show_tags_and_lengths)
			{
				proto_tree_add_item(pppoe_tree, hf_pppoed_tag, tvb, tagstart, 2, ENC_BIG_ENDIAN);
				pppoe_tree_tag_length_item =
					proto_tree_add_item(pppoe_tree, hf_pppoed_tag_length, tvb, tagstart+2, 2, ENC_BIG_ENDIAN);
			}

			/* Show tag data */
			switch (poe_tag)
			{
				case PPPOE_TAG_SVC_NAME:
					if (poe_tag_length > 0)
					{
						proto_tree_add_item(pppoe_tree, hf_pppoed_tag_service_name, tvb,
						                    tagstart+4, poe_tag_length, ENC_ASCII|ENC_NA);
					}
					break;
				case PPPOE_TAG_AC_NAME:
					proto_tree_add_item(pppoe_tree, hf_pppoed_tag_ac_name, tvb,
					                    tagstart+4, poe_tag_length, ENC_ASCII|ENC_NA);
					/* Show AC-Name in info column */
					if (check_col(pinfo->cinfo, COL_INFO))
					{
						col_append_fstr(pinfo->cinfo, COL_INFO, " AC-Name='%s'",
						               tvb_get_ephemeral_string(tvb, tagstart+4, poe_tag_length));
					}
					break;
				case PPPOE_TAG_HOST_UNIQ:
					proto_tree_add_item(pppoe_tree, hf_pppoed_tag_host_uniq, tvb,
					                    tagstart+4, poe_tag_length, ENC_NA);
					break;
				case PPPOE_TAG_AC_COOKIE:
					proto_tree_add_item(pppoe_tree, hf_pppoed_tag_ac_cookie, tvb,
					                    tagstart+4, poe_tag_length, ENC_NA);
					break;
				case PPPOE_TAG_VENDOR:
					if (poe_tag_length >= 4)
					{
						proto_tree_add_item(pppoe_tree, hf_pppoed_tag_vendor_id, tvb,
											tagstart+4, 4, ENC_BIG_ENDIAN);
					}
					if (poe_tag_length > 4)
					{
						guint32 vendor_id = tvb_get_ntohl(tvb, tagstart+4);
						switch (vendor_id)
						{
							case PPPOE_VENDOR_ID_DSLF:
								dissect_pppoe_subtags_dslf(tvb,pinfo,tagstart+4+4,pppoe_tree,poe_tag_length-4);
								break;
							default:
								proto_tree_add_item(pppoe_tree, hf_pppoed_tag_vendor_unspecified, tvb,
										    tagstart+4+4, poe_tag_length-4, ENC_NA);

						}
					}
					break;
				case PPPOE_TAG_CREDITS:
					if (poe_tag_length == 4)
					{
						proto_tree_add_item(pppoe_tree, hf_pppoed_tag_credits_fcn, tvb,
						                    tagstart+4, 2, ENC_BIG_ENDIAN);
						proto_tree_add_item(pppoe_tree, hf_pppoed_tag_credits_bcn, tvb,
						                    tagstart+6, 2, ENC_BIG_ENDIAN);
					} else {
						proto_tree_add_item(pppoe_tree, hf_pppoed_tag_credits, tvb,
						                    tagstart+4, poe_tag_length, ENC_NA);
					}
					break;
				case PPPOE_TAG_METRICS:
					if (poe_tag_length == 10)
					{
                                                poe_rsv = tvb_get_ntohs(tvb, tagstart+4);

                                                proto_tree_add_item(pppoe_tree, hf_pppoed_tag_mdr_units, tvb,
                                                                    tagstart+4, 2, ENC_BIG_ENDIAN);
                                                proto_tree_add_item(pppoe_tree, hf_pppoed_tag_cdr_units, tvb,
                                                                    tagstart+4, 2, ENC_BIG_ENDIAN);
                                                proto_tree_add_item(pppoe_tree, hf_pppoed_tag_metrics_r, tvb,
						                    tagstart+4, 2, ENC_BIG_ENDIAN);
						proto_tree_add_item(pppoe_tree, hf_pppoed_tag_metrics_rlq, tvb,
						                    tagstart+6, 1, ENC_BIG_ENDIAN);
						proto_tree_add_item(pppoe_tree, hf_pppoed_tag_metrics_resource, tvb,
						                    tagstart+7, 1, ENC_BIG_ENDIAN);
						proto_tree_add_item(pppoe_tree, hf_pppoed_tag_metrics_latency, tvb,
						                    tagstart+8, 2, ENC_BIG_ENDIAN);

                                                /* CDR */
						ti = proto_tree_add_item(pppoe_tree, hf_pppoed_tag_metrics_curr_drate, tvb,
                                                                         tagstart+10, 2, ENC_BIG_ENDIAN);

                                                switch ((poe_rsv & PPPOE_CDR_MASK) >> 1)
                                                {
                                                case (PPPOE_SCALE_KBPS):
                                                    proto_item_append_text(ti, " kbps");
                                                    break;
                                                case (PPPOE_SCALE_MBPS):
                                                    proto_item_append_text(ti, " mbps");
                                                    break;
                                                case (PPPOE_SCALE_GBPS):
                                                    proto_item_append_text(ti, " gbps");
                                                    break;
                                                case (PPPOE_SCALE_TBPS):
                                                    proto_item_append_text(ti, " tbps");
                                                    break;
                                                }

                                                /* MDR */
						ti = proto_tree_add_item(pppoe_tree, hf_pppoed_tag_metrics_max_drate, tvb,
						                    tagstart+12, 2, ENC_BIG_ENDIAN);

                                                switch ((poe_rsv & PPPOE_MDR_MASK) >> 3)
                                                {
                                                case (PPPOE_SCALE_KBPS):
                                                    proto_item_append_text(ti, " kbps");
                                                    break;
                                                case (PPPOE_SCALE_MBPS):
                                                    proto_item_append_text(ti, " mbps");
                                                    break;
                                                case (PPPOE_SCALE_GBPS):
                                                    proto_item_append_text(ti, " gbps");
                                                    break;
                                                case (PPPOE_SCALE_TBPS):
                                                    proto_item_append_text(ti, " tbps");
                                                    break;
                                                }

					} else {
						proto_tree_add_item(pppoe_tree, hf_pppoed_tag_metrics, tvb,
						                    tagstart+4, poe_tag_length, ENC_NA);
					}
					break;
				case PPPOE_TAG_SEQ_NUM:
					if (poe_tag_length == 2) {
						proto_tree_add_item(pppoe_tree, hf_pppoed_tag_seq_num, tvb,
								    tagstart+4, poe_tag_length, ENC_BIG_ENDIAN);
					} else {
						if (global_pppoe_show_tags_and_lengths) {
							proto_item_append_text(pppoe_tree_tag_length_item, " [Wrong: should be 2]");
							item = pppoe_tree_tag_length_item;
						} else {
							item = proto_tree_add_text(pppoe_tree, tvb, tagstart+4, poe_tag_length,
							    "%s: Wrong length: %u (expected 2)",
							    proto_registrar_get_name(hf_pppoed_tag_seq_num),
							    poe_tag_length);
						}
						expert_add_info_format(pinfo, item, PI_MALFORMED, PI_WARN,
								       "Sequence Number tag: Wrong length: %u (expected 2)",
								       poe_tag_length);
					}
					break;
                                case PPPOE_TAG_CRED_SCALE:
					if (poe_tag_length == 2) {
						proto_tree_add_item(pppoe_tree, hf_pppoed_tag_cred_scale, tvb,
								    tagstart+4, poe_tag_length, ENC_BIG_ENDIAN);
					} else {
						if (global_pppoe_show_tags_and_lengths) {
							proto_item_append_text(pppoe_tree_tag_length_item, " [Wrong: should be 2]");
							item = pppoe_tree_tag_length_item;
						} else {
							item = proto_tree_add_text(pppoe_tree, tvb, tagstart+4, poe_tag_length,
							    "%s: Wrong length: %u (expected 2)",
							    proto_registrar_get_name(hf_pppoed_tag_cred_scale),
							    poe_tag_length);
						}
						expert_add_info_format(pinfo, item, PI_MALFORMED, PI_WARN,
								       "Credit Scale Factor tag: Wrong length: %u (expected 2)",
								       poe_tag_length);
					}
                                        break;
				case PPPOE_TAG_RELAY_ID:
					proto_tree_add_item(pppoe_tree, hf_pppoed_tag_relay_session_id, tvb,
					                    tagstart+4, poe_tag_length, ENC_NA);
					break;
				case PPPOE_TAG_HURL:
					proto_tree_add_item(pppoe_tree, hf_pppoed_tag_hurl, tvb,
					                    tagstart+4, poe_tag_length, ENC_NA);
					break;
				case PPPOE_TAG_MOTM:
					proto_tree_add_item(pppoe_tree, hf_pppoed_tag_motm, tvb,
					                    tagstart+4, poe_tag_length, ENC_NA);
					break;
				case PPPOE_TAG_MAX_PAYLD:
					proto_tree_add_item(pppoe_tree, hf_pppoed_tag_max_payload, tvb,
					                    tagstart+4, poe_tag_length, ENC_NA);
					break;
				case PPPOE_TAG_IP_RT_ADD:
					proto_tree_add_item(pppoe_tree, hf_pppoed_tag_ip_route_add, tvb,
					                    tagstart+4, poe_tag_length, ENC_NA);
					break;

				/* These error tag values should be interpreted as a utf-8 unterminated
				   strings. */
				case PPPOE_TAG_SVC_ERR:
					proto_tree_add_item(pppoe_tree, hf_pppoed_tag_service_name_error, tvb,
					                    tagstart+4, poe_tag_length, ENC_ASCII|ENC_NA);
					break;
				case PPPOE_TAG_AC_ERR:
					proto_tree_add_item(pppoe_tree, hf_pppoed_tag_ac_system_error, tvb,
					                    tagstart+4, poe_tag_length, ENC_ASCII|ENC_NA);
					break;
				case PPPOE_TAG_GENERIC_ERR:
					proto_tree_add_item(pppoe_tree, hf_pppoed_tag_generic_error, tvb,
					                    tagstart+4, poe_tag_length, ENC_ASCII|ENC_NA);
					break;

				/* Get out if see end-of-list tag */
				case PPPOE_TAG_EOL:
					return;

				default:
					if (poe_tag_length > 0 )
					{
						/* Presumably unknown tag;
						   show tag value if we didn't
						   do it above */
						if (!global_pppoe_show_tags_and_lengths)
						{
							proto_tree_add_item(pppoe_tree, hf_pppoed_tag, tvb, tagstart, 2, ENC_BIG_ENDIAN);
							proto_tree_add_item(pppoe_tree, hf_pppoed_tag_length, tvb, tagstart+2, 2, ENC_BIG_ENDIAN);
						}
						proto_tree_add_item(pppoe_tree, hf_pppoed_tag_unknown_data, tvb,
								tagstart+2, poe_tag_length, ENC_NA);
					}
			}

			tagstart += (4 + poe_tag_length);
		}
	}
}


/* Discovery protocol, i.e. PPP session not yet established */
static void dissect_pppoed(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
	guint8  pppoe_code;
	guint16 reported_payload_length;

	proto_tree  *pppoe_tree = NULL;
	proto_item  *ti;

	col_set_str(pinfo->cinfo, COL_PROTOCOL, "PPPoED");
	col_clear(pinfo->cinfo, COL_INFO);

	/* Start Decoding Here. */
	pppoe_code = tvb_get_guint8(tvb, 1);

	if (check_col(pinfo->cinfo, COL_INFO))
	{
		col_append_str(pinfo->cinfo, COL_INFO, val_to_str_const(pppoe_code, code_vals, "Unknown"));
	}

	/* Read length of payload */
	reported_payload_length = tvb_get_ntohs(tvb, 4);

	if (tree)
	{
		ti = proto_tree_add_item(tree, proto_pppoed, tvb, 0, reported_payload_length+6, ENC_NA);
		pppoe_tree = proto_item_add_subtree(ti, ett_pppoed);

		/* Dissect fixed fields */
		proto_tree_add_item(pppoe_tree, hf_pppoe_version, tvb, 0, 1, ENC_BIG_ENDIAN);
		proto_tree_add_item(pppoe_tree, hf_pppoe_type, tvb, 0, 1, ENC_BIG_ENDIAN);
		proto_tree_add_item(pppoe_tree, hf_pppoe_code, tvb, 1, 1, ENC_BIG_ENDIAN);
		proto_tree_add_item(pppoe_tree, hf_pppoe_session_id, tvb, 2, 2, ENC_BIG_ENDIAN);
		proto_tree_add_item(pppoe_tree, hf_pppoe_payload_length, tvb, 4, 2, ENC_BIG_ENDIAN);
	}

	/* Now dissect any tags */
	if (reported_payload_length > 0)
	{
		dissect_pppoe_tags(tvb, pinfo, 6, pppoe_tree, 6+reported_payload_length);
	}

}

void proto_register_pppoed(void)
{
	static hf_register_info hf[] =
	{
		/* Discovery tag fields */
		{ &hf_pppoed_tags,
			{ "PPPoE Tags", "pppoed.tags", FT_NONE, BASE_NONE,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag,
			{ "Tag", "pppoed.tag", FT_UINT16, BASE_HEX,
				 VALS(tag_vals), 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_length,
			{ "Tag Length", "pppoed.tag_length", FT_UINT16, BASE_DEC,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_length_8,
			{ "Tag Length", "pppoed.tag_length_8", FT_UINT8, BASE_DEC,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_unknown_data,
			{ "Unknown Data", "pppoed.tag.unknown_data", FT_BYTES, BASE_NONE,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_service_name,
			{ "Service-Name", "pppoed.tags.service_name", FT_STRING, BASE_NONE,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_ac_name,
			{ "AC-Name", "pppoed.tags.ac_name", FT_STRING, BASE_NONE,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_host_uniq,
			{ "Host-Uniq", "pppoed.tags.host_uniq", FT_BYTES, BASE_NONE,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_ac_cookie,
			{ "AC-Cookie", "pppoed.tags.ac_cookie", FT_BYTES, BASE_NONE,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_vendor_id,
			{ "Vendor id", "pppoed.tags.vendor_id", FT_UINT32, BASE_DEC,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_vendor_unspecified,
			{ "Vendor unspecified", "pppoed.tags.vendor_unspecified", FT_BYTES, BASE_NONE,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_vspec_tags,
			{ "Vendor Specific PPPoE Tags", "pppoed.tags.vendorspecific.tags", FT_NONE, BASE_NONE,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_vspec_tag,
			{ "Tag", "pppoed.tags.vendorspecific.tag", FT_UINT8, BASE_HEX,
				 VALS(vspec_tag_vals), 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_vspec_circuit_id,
		        { "Circuit ID", "pppoed.tags.circuit_id", FT_STRING, BASE_NONE,
		                 NULL, 0x0, NULL, HFILL
		        }
		},
		{ &hf_pppoed_tag_vspec_remote_id,
		        { "Remote ID", "pppoed.tags.remote_id", FT_STRING, BASE_NONE,
		                 NULL, 0x0, NULL, HFILL
		        }
		},
		{ &hf_pppoed_tag_vspec_act_data_rate_up,
		        { "Actual Data Rate Upstream", "pppoed.tags.act_data_rate_up", FT_UINT32, BASE_DEC,
		                 NULL, 0x0, NULL, HFILL
		        }
		},
		{ &hf_pppoed_tag_vspec_act_data_rate_down,
		        { "Actual Data Rate Downstream", "pppoed.tags.act_data_rate_down", FT_UINT32, BASE_DEC,
		                 NULL, 0x0, NULL, HFILL
		        }
		},
		{ &hf_pppoed_tag_vspec_min_data_rate_up,
		        { "Minimum Data Rate Upstream", "pppoed.tags.min_data_rate_up", FT_UINT32, BASE_DEC,
		                 NULL, 0x0, NULL, HFILL
		        }
		},
		{ &hf_pppoed_tag_vspec_min_data_rate_down,
		        { "Minimum Data Rate Downstream", "pppoed.tags.min_data_rate_down", FT_UINT32, BASE_DEC,
		                 NULL, 0x0, NULL, HFILL
		        }
		},
		{ &hf_pppoed_tag_vspec_attainable_data_rate_up,
		        { "Attainable DataRate Upstream", "pppoed.tags.attainable_data_rate_up", FT_UINT32, BASE_DEC,
		                 NULL, 0x0, NULL, HFILL
		        }
		},
		{ &hf_pppoed_tag_vspec_attainable_data_rate_down,
		        { "Attainable DataRate Downstream", "pppoed.tags.attainable_data_rate_down", FT_UINT32, BASE_DEC,
		                 NULL, 0x0, NULL, HFILL
		        }
		},
		{ &hf_pppoed_tag_vspec_max_data_rate_up,
		        { "Maximum Data Rate Upstream", "pppoed.tags.max_data_rate_up", FT_UINT32, BASE_DEC,
		                 NULL, 0x0, NULL, HFILL
		        }
		},
		{ &hf_pppoed_tag_vspec_max_data_rate_down,
		        { "Maximum Data Rate Downstream", "pppoed.tags.max_data_rate_down", FT_UINT32, BASE_DEC,
		                 NULL, 0x0, NULL, HFILL
		        }
		},
		{ &hf_pppoed_tag_vspec_min_data_rate_up_lp,
		        { "Min DataRate Upstream in low power state", "pppoed.tags.min_data_rate_up_lp", FT_UINT32, BASE_DEC,
		                 NULL, 0x0, NULL, HFILL
		        }
		},
		{ &hf_pppoed_tag_vspec_min_data_rate_down_lp,
		        { "Minimum Data Rate Downstream in low power state", "pppoed.tags.min_data_rate_down_lp", FT_UINT32, BASE_DEC,
		                 NULL, 0x0, NULL, HFILL
		        }
		},
		{ &hf_pppoed_tag_vspec_max_int_delay_up,
		        { "Max Interleaving Delay Upstream", "pppoed.tags.max_int_delay_up", FT_UINT32, BASE_DEC,
		                 NULL, 0x0, NULL, HFILL
		        }
		},
		{ &hf_pppoed_tag_vspec_act_int_delay_up,
		        { "Actual Interleaving Delay Upstream", "pppoed.tags.act_int_delay_up", FT_UINT32, BASE_DEC,
		                 NULL, 0x0, NULL, HFILL
		        }
		},
		{ &hf_pppoed_tag_vspec_max_int_delay_down,
		        { "Maximum Interleaving Delay Downstream", "pppoed.tags.max_int_delay_down", FT_UINT32, BASE_DEC,
		                 NULL, 0x0, NULL, HFILL
		        }
		},
		{ &hf_pppoed_tag_vspec_act_int_delay_down,
		        { "Actual Interleaving Delay Downstream", "pppoed.tags.act_int_delay_down", FT_UINT32, BASE_DEC,
		                 NULL, 0x0, NULL, HFILL
		        }
		},
		{ &hf_pppoed_tag_vspec_access_loop_encapsulation,
		        { "Access-Loop-Encapsulation", "pppoed.tags.access_loop_encap", FT_NONE, BASE_NONE,
		                 NULL, 0x0, NULL, HFILL
		        }
		},
		{ &hf_pppoed_tag_vspec_access_loop_encap_data_link,
			{ "Data link", "pppoed.tags.access_loop_encap.data_link", FT_UINT8, BASE_HEX,
				 VALS(vspec_tag_dslf_access_loop_encap_data_link_vals), 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_vspec_access_loop_encap_encap_1,
			{ "Encaps 1", "pppoed.tags.access_loop_encap.encap_1", FT_UINT8, BASE_HEX,
				 VALS(vspec_tag_dslf_access_loop_encap_encap_1_vals), 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_vspec_access_loop_encap_encap_2,
			{ "Encaps 1", "pppoed.tags.access_loop_encap.encap_2", FT_UINT8, BASE_HEX,
				 VALS(vspec_tag_dslf_access_loop_encap_encap_2_vals), 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_credits,
			{ "Credits", "pppoed.tags.credits", FT_BYTES, BASE_NONE,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_credits_fcn,
			{ "FCN", "pppoed.tags.credits.fcn", FT_UINT16, BASE_DEC,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_credits_bcn,
			{ "BCN", "pppoed.tags.credits.bcn", FT_UINT16, BASE_DEC,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_metrics,
			{ "Metrics", "pppoed.tags.metrics", FT_BYTES, BASE_NONE,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_metrics_r,
			{ "Receive Only", "pppoed.tags.metrics.r", FT_BOOLEAN, 16,
				 NULL, PPPOE_RCV_ONLY_MASK, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_mdr_units,
			{ "MDR Units", "pppoed.tags.metrics.mdr_units", FT_UINT16, BASE_HEX,
				 VALS(datarate_scale_vals), PPPOE_MDR_MASK, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_cdr_units,
			{ "CDR Units", "pppoed.tags.metrics.cdr_units", FT_UINT16, BASE_HEX,
				 VALS(datarate_scale_vals), PPPOE_CDR_MASK, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_metrics_rlq,
			{ "Relative Link Quality", "pppoed.tags.metrics.rlq", FT_UINT8, BASE_DEC,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_metrics_resource,
			{ "Resource", "pppoed.tags.metrics.resource", FT_UINT8, BASE_DEC,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_metrics_latency,
			{ "Latency", "pppoed.tags.metrics.latency", FT_UINT16, BASE_DEC,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_metrics_curr_drate,
			{ "Curr. datarate", "pppoed.tags.metrics.curr_drate", FT_UINT16, BASE_DEC,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_metrics_max_drate,
			{ "Max. datarate", "pppoed.tags.metrics.max_drate", FT_UINT16, BASE_DEC,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_seq_num,
			{ "Sequence Number", "pppoed.tags.seq_num", FT_UINT16, BASE_HEX,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_cred_scale,
			{ "Credit Scale Factor", "pppoed.tags.credit_scale", FT_UINT16, BASE_DEC,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_relay_session_id,
			{ "Relay-Session-Id", "pppoed.tags.relay_session_id", FT_BYTES, BASE_NONE,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_hurl,
			{ "HURL", "pppoed.tags.hurl", FT_BYTES, BASE_NONE,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_motm,
			{ "MOTM", "pppoed.tags.motm", FT_BYTES, BASE_NONE,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_max_payload,
			{ "PPP Max Palyload", "pppoed.tags.max_payload", FT_BYTES, BASE_NONE,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_ip_route_add,
			{ "IP Route Add", "pppoed.tags.ip_route_add", FT_BYTES, BASE_NONE,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_service_name_error,
			{ "Service-Name-Error", "pppoed.tags.service_name_error", FT_STRING, BASE_NONE,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_ac_system_error,
			{ "AC-System-Error", "pppoed.tags.ac_system_error", FT_STRING, BASE_NONE,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoed_tag_generic_error,
			{ "Generic-Error", "pppoed.tags.generic_error", FT_STRING, BASE_NONE,
				 NULL, 0x0, NULL, HFILL
			}
		}
	};

	static gint *ett[] = {
		&ett_pppoed,
		&ett_pppoed_tags,
		&ett_pppoed_tag_vspec_dslf_access_loop_encaps
	};

	module_t *pppoed_module;

	/* Register protocol and fields */
	proto_pppoed = proto_register_protocol("PPP-over-Ethernet Discovery",
	                                       "PPPoED", "pppoed");
	proto_register_subtree_array(ett, array_length(ett));
	proto_register_field_array(proto_pppoed, hf, array_length(hf));

	/* Preference setting */
	pppoed_module = prefs_register_protocol(proto_pppoed, NULL);
	prefs_register_bool_preference(pppoed_module, "show_tags_and_lengths",
	                               "Show tag values and lengths",
	                               "Show values of tags and lengths of data fields",
	                               &global_pppoe_show_tags_and_lengths);
}

void proto_reg_handoff_pppoed(void)
{
	dissector_handle_t pppoed_handle;

	pppoed_handle = create_dissector_handle(dissect_pppoed, proto_pppoed);
	dissector_add_uint("ethertype", ETHERTYPE_PPPOED, pppoed_handle);
}


/* Session protocol, i.e. PPP session established */
static void dissect_pppoes(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
	guint8  pppoe_code;
	guint16 reported_payload_length;
	guint16 poe_tag_length;
	gint    actual_payload_length;
	gint    length, reported_length;
	gint    credit_offset = 0, tagstart = 0;
	guint16 cp_code;

	proto_tree  *pppoe_tree;
	proto_item  *ti = NULL;
	tvbuff_t    *next_tvb;

	col_set_str(pinfo->cinfo, COL_PROTOCOL, "PPPoES");
	col_clear(pinfo->cinfo, COL_INFO);

	/* Start Decoding Here. */
	pppoe_code = tvb_get_guint8(tvb, 1);

	if (check_col(pinfo->cinfo,COL_INFO))
	{
		col_add_str(pinfo->cinfo, COL_INFO,
		             val_to_str_const(pppoe_code, code_vals, "Unknown"));
	}

	reported_payload_length = tvb_get_ntohs(tvb, 4);
	actual_payload_length = tvb_reported_length_remaining(tvb, 6);

	if (tree)
	{
		ti = proto_tree_add_item(tree, proto_pppoes, tvb, 0, 6, ENC_NA);
		pppoe_tree = proto_item_add_subtree(ti, ett_pppoe);

		proto_tree_add_item(pppoe_tree, hf_pppoe_version, tvb, 0, 1, ENC_BIG_ENDIAN);
		proto_tree_add_item(pppoe_tree, hf_pppoe_type, tvb, 0, 1, ENC_BIG_ENDIAN);
		proto_tree_add_item(pppoe_tree, hf_pppoe_code, tvb, 1, 1, ENC_BIG_ENDIAN);
		proto_tree_add_item(pppoe_tree, hf_pppoe_session_id, tvb, 2, 2, ENC_BIG_ENDIAN);
		ti = proto_tree_add_item(pppoe_tree, hf_pppoe_payload_length, tvb, 4, 2, ENC_BIG_ENDIAN);


		if (PPPOE_TAG_CREDITS == tvb_get_ntohs(tvb, 6))
		{
			tagstart = 6;
			poe_tag_length = tvb_get_ntohs(tvb, tagstart + 2);

			/* Create tags subtree */
			ti = proto_tree_add_item(pppoe_tree, hf_pppoes_tags, tvb, tagstart, 8, ENC_NA);
			pppoe_tree = proto_item_add_subtree(ti, ett_pppoes_tags);

			/* Show tag data */
			if (poe_tag_length == 4)
			{
				proto_tree_add_item(pppoe_tree, hf_pppoes_tag_credits_fcn, tvb,
					tagstart+4, 2, ENC_BIG_ENDIAN);
				proto_tree_add_item(pppoe_tree, hf_pppoes_tag_credits_bcn, tvb,
					tagstart+6, 2, ENC_BIG_ENDIAN);
			} else {
				proto_tree_add_item(pppoe_tree, hf_pppoed_tag_credits, tvb,
					tagstart+4, poe_tag_length, ENC_NA);
			}

			credit_offset = 8;
		}
	}

	/*
	 * The only reason why the payload length from the header
	 * should differ from the remaining data in the packet
	 * would be if the total packet length, including Ethernet
	 * CRC, were < 64 bytes, so that padding was required.
	 *
	 * That means that you have 14 bytes of Ethernet header,
	 * 4 bytes of FCS, and fewer than 46 bytes of PPPoE packet.
	 *
	 * If that's not the case, we report a difference between
	 * the payload length in the packet, and the amount of
	 * data following the PPPoE header, as an error.
	 */
	if (tvb_reported_length(tvb) > 46) {
		/*
		 * Be forgiving about a possible trailing FCS.
		 *
		 * XXX - this dissector currently doesn't know
		 * whether any extra data past the end of the PPP
		 * payload is an FCS or not.
		 *
		 * If we know that we have an FCS, or that we don't
		 * have an FCS, we should have been handed a tvbuff
		 * without the FCS, and we should just do the strict
		 * length check.
		 *
		 * If we don't know whether we have an FCS, then:
		 *
		 *   if this isn't over Ethernet - the "E" in "PPPoE"
		 *   nonwithstanding, it can also run on top of 802.11,
		 *   for example - there's no trailer, so any data
		 *   past the payload length is either an FCS or
		 *   bogus;
		 *
		 *   if this is over Ethernet, there shouldn't be
		 *   a trailer, as the packet is long enough not to
		 *   require a trailer, as per the above;
		 *
		 * so perhaps we should assume that if we have exactly
		 * 4 bytes of extra information, it's an FCS, otherwise
		 * it's not.
		 *
		 * Perhaps we need to have a routine to call to
		 * do all the length checking, etc., and call it
		 * from here and from other dissectors where the
		 * protocol has a length field, or have a way to
		 * tell the dissector that called us which field
		 * has the length field and have *that* dissector
		 * do the length checking and add the expert info
		 * to the length field, *after* it does all the
		 * FCS heuristics.
		 */

		/* retrieve the control protocol code if it's there */
		cp_code = tvb_get_ntohs(tvb, 6);
		/*
		 * The session payload length expressly does not include pad bytes
		 *  when LCP or IPCP are present, so avoid the spurious error message
		 */
		if ((cp_code != PPP_LCP) && (cp_code != PPP_IPCP) &&
			(reported_payload_length != actual_payload_length) &&
			((reported_payload_length + 4) != actual_payload_length)) {
			proto_item_append_text(ti, " [incorrect, should be %u]",
				actual_payload_length);
			expert_add_info_format(pinfo, ti, PI_MALFORMED,
				PI_WARN, "Possible bad payload length %u != %u",
				reported_payload_length, actual_payload_length);
		}
	}

	/*
	 * Construct a tvbuff containing the PPP packet.
	 */
	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 > reported_payload_length)
		length = reported_payload_length;
	if ((guint)reported_length > reported_payload_length)
		reported_length = reported_payload_length;
	next_tvb = tvb_new_subset(tvb,(6 + credit_offset),
				(length - credit_offset),
				(reported_length - credit_offset));
	call_dissector(ppp_handle,next_tvb,pinfo,tree);
}

void proto_register_pppoes(void)
{

	static hf_register_info hf[] =
	{
		{ &hf_pppoes_tags,
			{ "PPPoE Tags", "pppoes.tags", FT_NONE, BASE_NONE,
				 NULL, 0x0, NULL, HFILL
			}
		},
#if 0
		{ &hf_pppoes_tag,
			{ "Tag", "pppoes.tag", FT_UINT16, BASE_HEX,
				 VALS(tag_vals), 0x0, NULL, HFILL
			}
		},
#endif
#if 0
		{ &hf_pppoes_tag_credits,
			{ "Credits", "pppoes.tags.credits", FT_BYTES, BASE_NONE,
				 NULL, 0x0, NULL, HFILL
			}
		},
#endif
		{ &hf_pppoes_tag_credits_fcn,
			{ "FCN", "pppoes.tags.credits.fcn", FT_UINT16, BASE_DEC,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoes_tag_credits_bcn,
			{ "BCN", "pppoes.tags.credits.bcn", FT_UINT16, BASE_DEC,
				 NULL, 0x0, NULL, HFILL
			}
		}
	};

	static gint *ett[] = {
		&ett_pppoes,
		&ett_pppoes_tags
	};

	/* Register protocol */
	proto_pppoes = proto_register_protocol("PPP-over-Ethernet Session", "PPPoES", "pppoes");

	proto_register_subtree_array(ett, array_length(ett));
	proto_register_field_array(proto_pppoes, hf, array_length(hf));
}

void proto_register_pppoe(void)
{
	static hf_register_info hf[] =
	{
		/* These fields common to discovery and session protocols */
		{ &hf_pppoe_version,
			{ "Version", "pppoe.version", FT_UINT8, BASE_DEC,
				 NULL, 0xf0, NULL, HFILL
			}
		},
		{ &hf_pppoe_type,
			{ "Type", "pppoe.type", FT_UINT8, BASE_DEC,
				 NULL, 0x0f, NULL, HFILL
			}
		},
		{ &hf_pppoe_code,
			{ "Code", "pppoe.code", FT_UINT8, BASE_HEX,
				 VALS(code_vals), 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoe_session_id,
			{ "Session ID", "pppoe.session_id", FT_UINT16, BASE_HEX,
				 NULL, 0x0, NULL, HFILL
			}
		},
		{ &hf_pppoe_payload_length,
			{ "Payload Length", "pppoe.payload_length", FT_UINT16, BASE_DEC,
				 NULL, 0x0, NULL, HFILL
			}
		}
	};

	static gint *ett[] = {
		&ett_pppoe
	};

	/* Register protocol */
	proto_pppoe = proto_register_protocol("PPP-over-Ethernet", "PPPoE", "pppoe");

	proto_register_subtree_array(ett, array_length(ett));
	proto_register_field_array(proto_pppoe, hf, array_length(hf));

}

void proto_reg_handoff_pppoes(void)
{
	dissector_handle_t pppoes_handle  =
	    create_dissector_handle(dissect_pppoes, proto_pppoes);
	dissector_add_uint("ethertype", ETHERTYPE_PPPOES, pppoes_handle);
	dissector_add_uint("wtap_encap", WTAP_ENCAP_PPP_ETHER, pppoes_handle);

	/* Get a handle for the PPP dissector */
	ppp_handle = find_dissector("ppp");
}
