/* packet-h1.c

 * Routines for Sinec H1 packet disassembly

 * Gerrit Gehnen <G.Gehnen@atrie.de>

 *

 * Wireshark - Network traffic analyzer

 * By Gerald Combs <gerald@wireshark.org>

 * Copyright 1998 Gerald Combs

 *

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

 */

#include "config.h"

#include <epan/packet.h>

void proto_register_h1(void);

void proto_reg_handoff_h1(void);

static int proto_h1;

static int hf_h1_header;

static int hf_h1_len;

static int hf_h1_block_type;

static int hf_h1_block_len;

static int hf_h1_opcode;

static int hf_h1_dbnr;

static int hf_h1_dwnr;

static int hf_h1_dlen;

static int hf_h1_org;

static int hf_h1_response_value;

#define EMPTY_BLOCK     0xFF

#define OPCODE_BLOCK    0x01

#define REQUEST_BLOCK   0x03

#define RESPONSE_BLOCK  0x0F

static const value_string block_type_vals[] = {

    { EMPTY_BLOCK,    "Empty Block" },

    { OPCODE_BLOCK,   "Opcode Block" },

    { REQUEST_BLOCK,  "Request Block" },

    { RESPONSE_BLOCK, "Response Block" },

    {0, NULL}

};

static const value_string opcode_vals[] = {

    {3, "Write Request"},

    {4, "Write Response"},

    {5, "Read Request"},

    {6, "Read Response"},

    {0, NULL}

};

static const value_string org_vals[] = {

    {0x01, "DB"},

    {0x02, "MB"},

    {0x03, "EB"},

    {0x04, "AB"},

    {0x05, "PB"},

    {0x06, "ZB"},

    {0x07, "TB"},

    {0x08, "BS"},

    {0x09, "AS"},

    {0x0a, "DX"},

    {0x10, "DE"},

    {0x11, "QB"},

    {0, NULL}

};

static const value_string returncode_vals[] = {

    {0x00, "No error"},

    {0x02, "Requested block does not exist"},

    {0x03, "Requested block too small"},

    {0xFF, "Error, reason unknown"},

    {0, NULL}

};

static int ett_h1;

static int ett_block;

static bool dissect_h1(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)

{

    proto_tree *h1_tree, *block_tree;

    proto_item *h1_ti, *block_ti;

    int offset = 0, offset_block_start;

    uint8_t h1_len;

    uint8_t block_type, block_len;

    tvbuff_t *next_tvb;

    if (tvb_captured_length(tvb) < 2) {

        /* Not enough data captured to hold the "S5" header; don't try

           to interpret it as H1. */

        return false;

    }

    if (!(tvb_get_uint8(tvb, 0) == 'S' && tvb_get_uint8(tvb, 1) == '5')) {

        return false;

    }

    col_set_str (pinfo->cinfo, COL_PROTOCOL, "H1");

    col_set_str(pinfo->cinfo, COL_INFO, "S5: ");

    h1_ti = proto_tree_add_item(tree, proto_h1, tvb, offset, -1, ENC_NA);

    h1_tree = proto_item_add_subtree(h1_ti, ett_h1);

    proto_tree_add_item(h1_tree, hf_h1_header, tvb, offset, 2, ENC_BIG_ENDIAN);

    offset += 2;

    h1_len = tvb_get_uint8(tvb, offset);

    proto_tree_add_item(h1_tree, hf_h1_len, tvb, offset, 1, ENC_BIG_ENDIAN);

    proto_item_set_len(h1_ti, h1_len);

    offset++;

    while (offset < h1_len) {

        offset_block_start = offset;

        block_type = tvb_get_uint8(tvb, offset);

        block_len = tvb_get_uint8(tvb, offset+1);

        if (!try_val_to_str(block_type, block_type_vals)) {

            /* XXX - should we skip unknown blocks? */

            return false;

        }

        if (block_len == 0) {

            /* XXX - expert info */

            break;

        }

        block_tree = proto_tree_add_subtree_format(h1_tree,

                tvb, offset, -1, ett_block, &block_ti, "%s",

                val_to_str_const(block_type, block_type_vals, "Unknown block"));

        proto_tree_add_item(block_tree, hf_h1_block_type,

                tvb, offset, 1, ENC_BIG_ENDIAN);

        /* we keep increasing offset as we go though the block

           however, to find the beginning of the next block,

           we use the current block's start offset and its length field */

        offset++;

        proto_tree_add_item(block_tree, hf_h1_block_len,

                tvb, offset, 1, ENC_BIG_ENDIAN);

        proto_item_set_len(block_ti, block_len);

        offset++;

        switch (block_type) {

            case OPCODE_BLOCK:

                proto_tree_add_item(block_tree, hf_h1_opcode,

                        tvb, offset, 1, ENC_BIG_ENDIAN);

                col_append_str (pinfo->cinfo, COL_INFO,

                        val_to_str(pinfo->pool, tvb_get_uint8(tvb,  offset),

                        opcode_vals, "Unknown Opcode (0x%2.2x)"));

                break;

            case REQUEST_BLOCK:

                proto_tree_add_item(block_tree, hf_h1_org, tvb,

                        offset, 1, ENC_BIG_ENDIAN);

                col_append_fstr(pinfo->cinfo, COL_INFO, " %s",

                        val_to_str(pinfo->pool, tvb_get_uint8(tvb,  offset),

                            org_vals,"Unknown Type (0x%2.2x)"));

                offset++;

                proto_tree_add_item(block_tree, hf_h1_dbnr, tvb,

                        offset, 1, ENC_BIG_ENDIAN);

                col_append_fstr(pinfo->cinfo, COL_INFO, " %d",

                        tvb_get_uint8(tvb,  offset));

                offset++;

                proto_tree_add_item(block_tree, hf_h1_dwnr, tvb,

                        offset, 2, ENC_BIG_ENDIAN);

                col_append_fstr (pinfo->cinfo, COL_INFO, " DW %d",

                        tvb_get_ntohs(tvb, offset));

                offset += 2;

                proto_tree_add_item(block_tree, hf_h1_dlen, tvb,

                        offset, 2, ENC_BIG_ENDIAN);

                col_append_fstr (pinfo->cinfo, COL_INFO, " Count %d",

                        tvb_get_ntohs(tvb, offset));

                break;

            case RESPONSE_BLOCK:

                proto_tree_add_item(block_tree, hf_h1_response_value,

                        tvb, offset, 1, ENC_BIG_ENDIAN);

                col_append_fstr (pinfo->cinfo, COL_INFO, " %s",

                        val_to_str(pinfo->pool, tvb_get_uint8(tvb,  offset),

                            returncode_vals,"Unknown Returncode (0x%2.2x"));

                break;

        }

        offset = offset_block_start + block_len; /* see the comment above */

    }

    if (tvb_reported_length_remaining(tvb, offset) > 0) {

        next_tvb = tvb_new_subset_remaining(tvb,  offset);

        call_data_dissector(next_tvb, pinfo, tree);

    }

    return true;

}

void

proto_register_h1 (void)

{

    static hf_register_info hf[] = {

        {&hf_h1_header,

            {"H1-Header", "h1.header", FT_UINT16, BASE_HEX, NULL, 0x0,

                NULL, HFILL }},

        {&hf_h1_len,

            {"Length indicator", "h1.len", FT_UINT16, BASE_DEC, NULL, 0x0,

                NULL, HFILL }},

        {&hf_h1_block_type,

            {"Block type", "h1.block_type", FT_UINT8, BASE_HEX, VALS(block_type_vals), 0x0,

                NULL, HFILL }},

        {&hf_h1_block_len,

            {"Block length", "h1.block_len", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},

        {&hf_h1_opcode,

            {"Opcode", "h1.opcode", FT_UINT8, BASE_HEX, VALS (opcode_vals), 0x0,

                NULL, HFILL }},

        {&hf_h1_org,

            {"Memory type", "h1.org", FT_UINT8, BASE_HEX, VALS (org_vals), 0x0,

                NULL, HFILL }},

        {&hf_h1_dbnr,

            {"Memory block number", "h1.dbnr", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},

        {&hf_h1_dwnr,

            {"Address within memory block", "h1.dwnr", FT_UINT16, BASE_DEC, NULL, 0x0,

                NULL, HFILL }},

        {&hf_h1_dlen,

            {"Length in words", "h1.dlen", FT_INT16, BASE_DEC, NULL, 0x0, NULL, HFILL }},

        {&hf_h1_response_value,

            {"Response value", "h1.resvalue", FT_UINT8, BASE_DEC,

                VALS (returncode_vals), 0x0, NULL, HFILL }}

    };

    static int *ett[] = {

        &ett_h1,

        &ett_block,

    };

    proto_h1 = proto_register_protocol ("Sinec H1 Protocol", "H1", "h1");

    proto_register_field_array (proto_h1, hf, array_length (hf));

    proto_register_subtree_array (ett, array_length (ett));

}

void

proto_reg_handoff_h1(void)

{

    heur_dissector_add("cotp", dissect_h1,

            "Sinec H1 over COTP", "hi_cotp", proto_h1, HEURISTIC_ENABLE);

    heur_dissector_add("cotp_is", dissect_h1,

            "Sinec H1 over COTP (inactive subset)", "hi_cotp_is", proto_h1, HEURISTIC_ENABLE);

    heur_dissector_add("tcp", dissect_h1,

            "Sinec H1 over TCP", "hi_tcp", proto_h1, HEURISTIC_ENABLE);

}

/*

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

 *

 * Local Variables:

 * c-basic-offset: 4

 * tab-width: 8

 * indent-tabs-mode: nil

 * End:

 *

 * ex: set shiftwidth=4 tabstop=8 expandtab:

 * :indentSize=4:tabSize=8:noTabs=true:

 */