/* packet-openflow.c

 * Routines for OpenFlow dissection

 * Copyright 2013, Anders Broman <anders.broman@ericsson.com>

 * Copyright 2013, Zoltan Lajos Kis <zoltan.lajos.kis@ericsson.com>

 *

 * Wireshark - Network traffic analyzer

 * By Gerald Combs <gerald@wireshark.org>

 * Copyright 1998 Gerald Combs

 *

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

 *

 * Ref https://www.opennetworking.org/sdn-resources/onf-specifications/openflow

 */

#include "config.h"

#include <epan/packet.h>

#include <epan/expert.h>

#include <epan/prefs.h>

#include "packet-tcp.h"

void proto_register_openflow(void);

void proto_reg_handoff_openflow(void);

#define OFP_LEGACY_PORT 6633

#define OFP_LEGACY2_PORT 6634

#define OFP_IANA_PORT 6653

static range_t *g_openflow_ports;

static dissector_handle_t openflow_handle;

static dissector_handle_t openflow_v1_handle;

static dissector_handle_t openflow_v4_handle;

static dissector_handle_t openflow_v5_handle;

static dissector_handle_t openflow_v6_handle;

/* Initialize the protocol and registered fields */

static int proto_openflow;

static int hf_openflow_version;

static expert_field ei_openflow_version;

static bool openflow_desegment = true;

#define OFP_VERSION_1_0 1

#define OFP_VERSION_1_1 2

#define OFP_VERSION_1_2 3

#define OFP_VERSION_1_3 4

#define OFP_VERSION_1_4 5

#define OFP_VERSION_1_5 6

static const value_string openflow_version_values[] = {

    { OFP_VERSION_1_0, "1.0" },

    { OFP_VERSION_1_1, "1.1" },

    { OFP_VERSION_1_2, "1.2" },

    { OFP_VERSION_1_3, "1.3" },

    { OFP_VERSION_1_4, "1.4" },

    { OFP_VERSION_1_5, "1.5" },

    { 0, NULL }

};

static unsigned

get_openflow_pdu_length(packet_info *pinfo _U_, tvbuff_t *tvb,

                        int offset, void *data _U_)

{

    return tvb_get_ntohs(tvb, offset + 2);

}

static int

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

{

    unsigned offset = 0;

    uint8_t version;

    proto_item* ti;

    version = tvb_get_uint8(tvb, 0);

    /* Set the Protocol column to the constant string of openflow */

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

    col_clear(pinfo->cinfo,COL_INFO);

    switch(version){

    case OFP_VERSION_1_0:

        call_dissector(openflow_v1_handle, tvb, pinfo, tree);

        break;

    case OFP_VERSION_1_3:

        call_dissector(openflow_v4_handle, tvb, pinfo, tree);

        break;

    case OFP_VERSION_1_4:

        call_dissector(openflow_v5_handle, tvb, pinfo, tree);

        break;

    case OFP_VERSION_1_5:

        call_dissector(openflow_v6_handle, tvb, pinfo, tree);

        break;

    default:

        ti = proto_tree_add_item(tree, hf_openflow_version, tvb, offset, 1, ENC_BIG_ENDIAN);

        expert_add_info(pinfo, ti, &ei_openflow_version);

        break;

    }

    return tvb_reported_length(tvb);

}

#define OFP_HEADER_LEN  8

static int

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

{

    tcp_dissect_pdus(tvb, pinfo, tree, openflow_desegment, OFP_HEADER_LEN,

                     get_openflow_pdu_length, dissect_openflow_tcp_pdu, data);

    return tvb_captured_length(tvb);

}

static bool

dissect_openflow_heur(tvbuff_t *tvb, packet_info *pinfo,

                     proto_tree *tree, void *data)

{

    conversation_t *conversation = NULL;

    if ((pinfo->destport != OFP_LEGACY_PORT) &&

        (pinfo->destport != OFP_LEGACY2_PORT) &&

        (pinfo->destport != OFP_IANA_PORT) &&

        (!value_is_in_range(g_openflow_ports, pinfo->destport))) {

        return false;

    }

    conversation = find_or_create_conversation(pinfo);

    conversation_set_dissector(conversation, openflow_handle);

    dissect_openflow(tvb, pinfo, tree, data);

    return true;

}

static void

apply_openflow_prefs(void)

{

    /* Openflow uses the port preference for heuristics */

    g_openflow_ports = prefs_get_range_value("openflow", "tcp.port");

}

/*

 * Register the protocol with Wireshark.

 */

void

proto_register_openflow(void)

{

    static hf_register_info hf[] = {

        { &hf_openflow_version,

            { "Version", "openflow.version",

               FT_UINT8, BASE_HEX, VALS(openflow_version_values), 0x7f,

               NULL, HFILL }

        }

    };

    static ei_register_info ei[] = {

        { &ei_openflow_version, { "openflow.version.unknown", PI_UNDECODED, PI_WARN, "Unsupported version not dissected", EXPFILL }},

    };

    module_t *openflow_module;

    expert_module_t* expert_openflow;

    /* Register the protocol name and description */

    proto_openflow = proto_register_protocol("OpenFlow", "OpenFlow", "openflow");

    openflow_handle = register_dissector("openflow", dissect_openflow, proto_openflow);

    /* Required function calls to register the header fields and subtrees */

    proto_register_field_array(proto_openflow, hf, array_length(hf));

    expert_openflow = expert_register_protocol(proto_openflow);

    expert_register_field_array(expert_openflow, ei, array_length(ei));

    openflow_module = prefs_register_protocol(proto_openflow, apply_openflow_prefs);

    /* Register heuristic preference */

    prefs_register_obsolete_preference(openflow_module, "heuristic");

    /* Register desegment preference */

    prefs_register_bool_preference(openflow_module, "desegment",

                                  "Reassemble OpenFlow messages spanning multiple TCP segments",

                                  "Whether the OpenFlow dissector should reassemble messages spanning multiple TCP segments."

                                  " To use this option, you must also enable \"Allow subdissectors to reassemble TCP streams\" in the TCP protocol settings.",

                                  &openflow_desegment);

}

void

proto_reg_handoff_openflow(void)

{

    heur_dissector_add("tcp", dissect_openflow_heur, "OpenFlow over TCP", "openflow_tcp", proto_openflow, HEURISTIC_ENABLE);

    dissector_add_uint_with_preference("tcp.port", OFP_IANA_PORT, openflow_handle);

    openflow_v1_handle = find_dissector_add_dependency("openflow_v1", proto_openflow);

    openflow_v4_handle = find_dissector_add_dependency("openflow_v4", proto_openflow);

    openflow_v5_handle = find_dissector_add_dependency("openflow_v5", proto_openflow);

    openflow_v6_handle = find_dissector_add_dependency("openflow_v6", proto_openflow);

    apply_openflow_prefs();

}

/*

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

 *

 * Local variables:

 * c-basic-offset: 4

 * tab-width: 8

 * indent-tabs-mode: nil

 * End:

 *

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

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

 */