/* packet-extreme-exeh.c

 * Routines for the disassembly of Extreme Networks internal

 * Ethernet capture headers

 *

 * Copyright 2021 Joerg Mayer (see AUTHORS file)

 *

 * Wireshark - Network traffic analyzer

 * By Gerald Combs <gerald@wireshark.org>

 * Copyright 1998 Gerald Combs

 *

 * SPDX-License-Identifier: GPL-2.0-or-later

 */

/*

 * It is possible to create internal capture in EXOS with

 * debug packet capture ...

 *

 * List of interfaces on all VRs:

 * run script shell.py cat /proc/net/dev

 * on older software the following should work as well:

 * debug packet capture on cmd-args "-D -1"

 *

 * See:

 *  https://extremeportal.force.com/ExtrArticleDetail?an=000079573

 *  https://extremeportal.force.com/ExtrArticleDetail?an=000082238

 *  https://extremeportal.force.com/ExtrArticleDetail?an=000079220

 *

 * This capture begins with an internal header (maybe containing some HiGig variant?),

 * followed by the "original" Ethernet frame.

 */

/*

 * TODO

 * 00 - 01: Unknown

 *          always zero for incoming(?)

 *          often non-zero for outgoing

 * 10 - 23: Unknown (traffic properties?)

 * 28 - 29: Unknown

 *          always zero(?)

 * 32 - 33: Unknown

 *          always zero(?)

 */

#include "config.h"

#include <epan/packet.h>

#include <epan/etypes.h>

#include <epan/expert.h>

#include <epan/tfs.h>

void proto_register_exeh(void);

void proto_reg_handoff_exeh(void);

static dissector_handle_t exeh_handle;

static dissector_handle_t ethnofcs_handle;

static int proto_exeh;

/* EXEH data */

static int hf_exeh_unknown_00_01;

static int hf_exeh_module1;

static int hf_exeh_port1;

static int hf_exeh_module2; /* m2 + p2 always zero for outgoing(?) */

static int hf_exeh_port2;

static int hf_exeh_unknown_10_16;

static int hf_exeh_unknown_17_0xfd;

static int hf_exeh_unknown_17_0x02;

static int hf_exeh_unknown_18_21;

static int hf_exeh_unknown_22_23;

static int hf_exeh_incoming_framesource;

static int hf_exeh_outgoing_framesource;

static int hf_exeh_vlan;

static int hf_exeh_unknown_28_29;

static int hf_exeh_dir;

static int hf_exeh_unknown_32_33;

static int hf_exeh_etype;

static int hf_exeh_etypelen;

static int hf_exeh_etypedata;

static expert_field ei_exeh_unexpected_value;

static expert_field ei_exeh_unequal_ports;

static expert_field ei_exeh_incoming_framesource;

static expert_field ei_exeh_outgoing_framesource;

static int ett_exeh;

static const value_string exeh_direction_vals[] = {

  {0x07, "Incoming"},

  {0xff, "Outgoing"},

  {0, NULL},

};

static const value_string exeh_outgoing_vlanid_vals[] = {

  {0x0000, "No tag or VLAN ID = 0"},

  {0x000f, "Has VLAN ID"},

  {0, NULL},

};

static const value_string exeh_incoming_framesource_vals[] = {

  {0x0000, "N/A"},

  {0, NULL},

};

static const value_string exeh_outgoing_framesource_vals[] = {

  {0x0000, "CPU"},

  {0x4248, "Broadcom Hardware"},

  {0, NULL},

};

static int

dissect_exeh(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)

{

  proto_item *ti;

  proto_tree *exeh_tree;

  uint32_t offset = 0;

  uint32_t etype, module1, port1, module2, port2, direction, framesource;

  int32_t databytes;

  tvbuff_t *frame_tvb;

  col_set_str(pinfo->cinfo, COL_PROTOCOL, "EXEH");

  col_set_str(pinfo->cinfo, COL_INFO, "EXEH:");

  ti = proto_tree_add_item(tree, proto_exeh, tvb, offset, -1,

         ENC_NA);

  exeh_tree = proto_item_add_subtree(ti, ett_exeh);

  direction = tvb_get_ntohs(tvb, 30);

  proto_tree_add_item(exeh_tree, hf_exeh_unknown_00_01, tvb, offset, 2, ENC_NA);

  offset += 2;

  proto_tree_add_item_ret_uint(exeh_tree, hf_exeh_module1, tvb, offset, 2, ENC_BIG_ENDIAN, &module1);

  offset += 2;

  proto_tree_add_item_ret_uint(exeh_tree, hf_exeh_port1, tvb, offset, 2, ENC_BIG_ENDIAN, &port1);

  offset += 2;

  proto_tree_add_item_ret_uint(exeh_tree, hf_exeh_module2, tvb, offset, 2, ENC_BIG_ENDIAN, &module2);

  offset += 2;

  ti = proto_tree_add_item_ret_uint(exeh_tree, hf_exeh_port2, tvb, offset, 2, ENC_BIG_ENDIAN, &port2);

  if ( !(direction == 255 && module2 == 0) && (module1 != module2 || port1 != port2) )

      expert_add_info(pinfo, ti, &ei_exeh_unequal_ports);

  offset += 2;

  proto_tree_add_item(exeh_tree, hf_exeh_unknown_10_16, tvb, offset, 7, ENC_NA);

  offset += 7;

  proto_tree_add_item(exeh_tree, hf_exeh_unknown_17_0xfd, tvb, offset, 1, ENC_NA);

  proto_tree_add_item(exeh_tree, hf_exeh_unknown_17_0x02, tvb, offset, 1, ENC_NA);

  offset += 1;

  proto_tree_add_item(exeh_tree, hf_exeh_unknown_18_21, tvb, offset, 4, ENC_NA);

  offset += 4;

  proto_tree_add_item(exeh_tree, hf_exeh_unknown_22_23, tvb, offset, 2, ENC_BIG_ENDIAN);

  offset += 2;

  if ( direction == 7 ) {

    ti = proto_tree_add_item_ret_uint(exeh_tree, hf_exeh_incoming_framesource, tvb, offset, 2, ENC_BIG_ENDIAN, &framesource);

    if ( framesource != 0 )

      expert_add_info(pinfo, ti, &ei_exeh_incoming_framesource);

  } else { /* Direction == 255 */

    ti = proto_tree_add_item_ret_uint(exeh_tree, hf_exeh_outgoing_framesource, tvb, offset, 2, ENC_BIG_ENDIAN, &framesource);

    if ( framesource != 0 && framesource != 0x4248 )

      expert_add_info(pinfo, ti, &ei_exeh_outgoing_framesource);

  }

  offset += 2;

  proto_tree_add_item(exeh_tree, hf_exeh_vlan, tvb, offset, 2, ENC_BIG_ENDIAN);

  offset += 2;

  proto_tree_add_item(exeh_tree, hf_exeh_unknown_28_29, tvb, offset, 2, ENC_NA);

  offset += 2;

  proto_tree_add_item(exeh_tree, hf_exeh_dir, tvb, offset, 2, ENC_BIG_ENDIAN);

  offset += 2;

  proto_tree_add_item(exeh_tree, hf_exeh_unknown_32_33, tvb, offset, 2, ENC_NA);

  offset += 2;

  proto_tree_add_item_ret_uint(exeh_tree, hf_exeh_etype, tvb, offset, 2, ENC_BIG_ENDIAN, &etype);

  switch (etype) {

  case 0x8100: /* VLAN/VMAN Tag */

    ti = proto_tree_add_item_ret_int(exeh_tree, hf_exeh_etypelen, tvb, offset+2, 2, ENC_BIG_ENDIAN, &databytes);

    if ((int)tvb_reported_length_remaining(tvb, offset) != databytes)

      expert_add_info(pinfo, ti, &ei_exeh_unexpected_value);

    break;

  default:

    proto_tree_add_item(exeh_tree, hf_exeh_etypedata, tvb, offset+2, 2, ENC_BIG_ENDIAN);

  }

  offset += 4;

  frame_tvb = tvb_new_subset_remaining(tvb, offset);

  call_dissector(ethnofcs_handle, frame_tvb, pinfo, tree);

  return tvb_captured_length(tvb);

}

void

proto_register_exeh(void)

{

  static hf_register_info hf[] = {

  /* EXEH data */

    { &hf_exeh_unknown_00_01,

    { "Unknown_00", "exeh.unknown00", FT_BYTES, BASE_NONE, NULL,

      0x0, NULL, HFILL }},

    { &hf_exeh_module1,

    { "Module", "exeh.module1", FT_UINT16, BASE_DEC, NULL,

      0x0, NULL, HFILL }},

    { &hf_exeh_port1,

    { "Port", "exeh.port1", FT_UINT16, BASE_DEC, NULL,

      0x0, NULL, HFILL }},

    { &hf_exeh_module2,

    { "Module", "exeh.module2", FT_UINT16, BASE_DEC, NULL,

      0x0, NULL, HFILL }},

    { &hf_exeh_port2,

    { "Port", "exeh.port2", FT_UINT16, BASE_DEC, NULL,

      0x0, NULL, HFILL }},

    { &hf_exeh_unknown_10_16,

    { "Unknown_10 (incoming specific?)",  "exeh.unknown10", FT_BYTES, BASE_NONE, NULL,

      0x0, NULL, HFILL }},

    { &hf_exeh_unknown_17_0xfd,

    { "Unknown_17", "exeh.unknown17", FT_UINT8, BASE_HEX, NULL,

      0xfd, NULL, HFILL }},

    { &hf_exeh_unknown_17_0x02,

    { "Unknown_17 (Add dot1Q?)",  "exeh.unknown17.dot1q", FT_BOOLEAN, 8, TFS(&tfs_no_yes),

      0x02, NULL, HFILL }},

    { &hf_exeh_unknown_18_21,

    { "Unknown_18 (outgoing specific?)",  "exeh.unknown18", FT_BYTES, BASE_NONE, NULL,

      0x0, NULL, HFILL }},

    { &hf_exeh_unknown_22_23,

    { "Add VLAN ID?", "exeh.unknown22", FT_UINT16, BASE_NONE, VALS(exeh_outgoing_vlanid_vals),

      0x0, NULL, HFILL }},

    { &hf_exeh_incoming_framesource,

    { "Frame source", "exeh.framesource", FT_UINT16, BASE_HEX, VALS(exeh_incoming_framesource_vals),

      0x0, NULL, HFILL }},

    { &hf_exeh_outgoing_framesource,

    { "Frame source", "exeh.framesource", FT_UINT16, BASE_HEX, VALS(exeh_outgoing_framesource_vals),

      0x0, NULL, HFILL }},

    { &hf_exeh_vlan,

    { "Transport VLAN", "exeh.vlan", FT_UINT16, BASE_DEC, NULL,

      0x0, NULL, HFILL }},

    { &hf_exeh_unknown_28_29,

    { "Unknown_28", "exeh.unknown28", FT_BYTES, BASE_NONE, NULL,

      0x0, NULL, HFILL }},

    { &hf_exeh_dir,

    { "Direction",  "exeh.direction", FT_UINT16, BASE_HEX, VALS(exeh_direction_vals),

      0x0, NULL, HFILL }},

    { &hf_exeh_unknown_32_33,

    { "Unknown_32", "exeh.unknown32", FT_BYTES, BASE_NONE, NULL,

      0x0, NULL, HFILL }},

    { &hf_exeh_etype,

    { "Etype",  "exeh.etype", FT_UINT16, BASE_HEX, NULL,

      0x0, NULL, HFILL }},

    { &hf_exeh_etypedata,

    { "Etype data", "exeh.etypedata", FT_UINT16, BASE_HEX, NULL,

      0x0, NULL, HFILL }},

    { &hf_exeh_etypelen,

    { "Length", "exeh.etypelen", FT_INT16, BASE_DEC, NULL,

      0x0, "Bytes from 8100 to end of frame", HFILL }},

  };

  static int *ett[] = {

    &ett_exeh,

  };

  static ei_register_info ei[] = {

    { &ei_exeh_unexpected_value, { "exeh.unexpected_value", PI_PROTOCOL, PI_WARN, "Unexpected length", EXPFILL }},

    { &ei_exeh_unequal_ports, { "exeh.unequal_ports", PI_PROTOCOL, PI_WARN, "Unequal ports", EXPFILL }},

    { &ei_exeh_incoming_framesource, { "exeh.incoming_framesource", PI_PROTOCOL, PI_WARN, "Incoming framesource non-zero", EXPFILL }},

    { &ei_exeh_outgoing_framesource, { "exeh.outgoing_framesource", PI_PROTOCOL, PI_WARN, "Outgoing framesource unknown magic", EXPFILL }},

  };

  expert_module_t* expert_exeh;

  proto_exeh = proto_register_protocol("EXtreme extra Eth Header", "EXEH", "exeh");

  proto_register_field_array(proto_exeh, hf, array_length(hf));

  proto_register_subtree_array(ett, array_length(ett));

  expert_exeh = expert_register_protocol(proto_exeh);

  expert_register_field_array(expert_exeh, ei, array_length(ei));

  exeh_handle = register_dissector("exeh", dissect_exeh, proto_exeh);

}

void

proto_reg_handoff_exeh(void)

{

  ethnofcs_handle = find_dissector_add_dependency("eth_withoutfcs", proto_exeh);

  dissector_add_uint("ethertype", ETHERTYPE_EXEH, exeh_handle);

}

/*

 * Editor modelines  -  https://www.wireshark.org/tools/modelines.html

 *

 * Local variables:

 * c-basic-offset: 8

 * tab-width: 8

 * indent-tabs-mode: t

 * End:

 *

 * vi: set shiftwidth=8 tabstop=8 noexpandtab:

 * :indentSize=8:tabSize=8:noTabs=false:

 */