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/* packet-opsi.c
 * Routines for OPSI protocol dissection
 * Copyright 2004, Laurent Rabret (France Telecom R&D) <laurent.rabret@i.hate.spams.org>
 *
 * 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 <epan/packet.h>
#include <epan/prefs.h>
#include <epan/expert.h>

#include "packet-tcp.h"

void proto_register_opsi(void);
void proto_reg_handoff_opsi(void);

/* TCP destination port dedicated to the OPSI protocol */
#define TCP_PORT_OPSI           4002

/* Information position in OPSI header */
#define MAJOR_VERSION_OFFSET    0
#define MINOR_VERSION_OFFSET    1
#define CODE_OFFSET             2
#define HOOK_ID_OFFSET          3
#define PACKET_LENGTH_OFFSET    4
#define SESSION_OFFSET          6

#define HEADER_LENGTH           8


/* Valid OPSI code values */
#define DISCOVER_REQUEST        1
#define DISCOVER_RESPONSE       2
#define SERVICE_REQUEST         3
#define SERVICE_ACCEPT          4
#define SERVICE_REJECT          5
#define TERMINATE_REQUEST       6

/* Internal structure to dissect attributes */
typedef struct {
        guint16          attribute_type;        /* attribute code */
        const char      *tree_text;             /* text for fold out */
        gint            *tree_id;               /* id for add_item */
        int             *hf_type_attribute;     /* id for seach option */
        void            (*dissect)(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, proto_item *item,
                                   int* hfValue, int offset, int length);
} opsi_attribute_handle_t;


/* Attributes codes */
#define USER_NAME_ATTRIBUTE              1
#define USER_PASSWD_ATTRIBUTE            2
#define CHAP_PASSWD_ATTRIBUTE            3
#define NAS_IP_ADDRESS_ATTRIBUTE         4
#define NAS_PORT_ATTRIBUTE               5
#define SERVICE_TYPE_ATTRIBUTE           6
#define FRAMED_PROTOCOL_ATTRIBUTE        7
#define FRAMED_ADDRESS_ATTRIBUTE         8
#define FRAMED_NETMASK_ATTRIBUTE         9
#define FRAMED_ROUTING_ATTRIBUTE        10
#define FRAMED_FILTER_ATTRIBUTE         11
#define FRAMED_MTU_ATTRIBUTE            12
#define FRAMED_COMPRESSION_ATTRIBUTE    13
#define CALLED_STATION_ID_ATTRIBUTE     30
#define CALLING_STATION_ID_ATTRIBUTE    31
#define NAS_IDENTIFIER                  32
#define ACCOUNTING_40_ATTRIBUTE         40
#define ACCOUNTING_41_ATTRIBUTE         41
#define ACCOUNTING_42_ATTRIBUTE         42
#define ACCOUNTING_43_ATTRIBUTE         43
#define ACCOUNTING_SESSION_ID_ATTRIBUTE 44
#define ACCOUNTING_45_ATTRIBUTE         45
#define ACCOUNTING_46_ATTRIBUTE         46
#define ACCOUNTING_47_ATTRIBUTE         47
#define ACCOUNTING_48_ATTRIBUTE         48
#define ACCOUNTING_49_ATTRIBUTE         49
#define ACCOUNTING_50_ATTRIBUTE         50
#define ACCOUNTING_51_ATTRIBUTE         51
#define ACCOUNTING_52_ATTRIBUTE         52
#define ACCOUNTING_53_ATTRIBUTE         53
#define ACCOUNTING_54_ATTRIBUTE         54
#define ACCOUNTING_55_ATTRIBUTE         55
#define ACCOUNTING_56_ATTRIBUTE         56
#define ACCOUNTING_57_ATTRIBUTE         57
#define ACCOUNTING_58_ATTRIBUTE         58
#define ACCOUNTING_59_ATTRIBUTE         59
#define CHAP_CHALLENGE_ATTRIBUTE        60
#define NAS_PORT_TYPE_ATTRIBUTE         61
#define DESIGNATION_NUMBER_ATTRIBUTE    77
#define NAS_PORT_ID_ATTRIBUTE           87

#define SMC_AAAID_ATTRIBUTE             651
#define SMC_VPNID_ATTRIBUTE             652
#define SMC_VPNNAME_ATTRIBUTE           653
#define SMC_RANID_ATTRIBUTE             654
#define SMC_RANIP_ATTRIBUTE             655
#define SMC_RANNAME_ATTRIBUTE           656
#define SMC_POPID_ATTRIBUTE             657
#define SMC_POPNAME_ATTRIBUTE           658
#define SMC_SMCID_ATTRIBUTE             659
#define SMC_RECEIVE_TIME_ATTRIBUTE      660
#define SMC_STAT_TIME_ATTRIBUTE         661

#define OPSI_FLAGS_ATTRIBUTE            674
#define OPSI_APPLICATION_NAME_ATTRIBUTE 675

/*
 * Published API functions.  NOTE, "local" API functions
 * only valid from the packet-opsi file.
 */
static void decode_string_attribute(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, proto_item *item, int* hfValue, int offset, int length);
static void decode_ipv4_attribute(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, proto_item *item, int* hfValue, int offset, int length);
static void decode_longint_attribute(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, proto_item *item, int* hfValue, int offset, int length);
static void decode_value_string_attribute(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, proto_item *item, int* hfValue, int offset, int length);
static void decode_time_attribute(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, proto_item *item, int* hfValue, int offset, int length);
/******* *******/

/* Initialize the protocol and registered fields */
static int proto_opsi                   = -1;
static int hf_opsi_major_version        = -1;
static int hf_opsi_minor_version        = -1;
static int hf_opsi_opcode               = -1;
static int hf_opsi_hook_id              = -1;
static int hf_opsi_length               = -1;
static int hf_opsi_session_id           = -1;
static int hf_user_name_att             = -1;
static int hf_password_att              = -1;
static int hf_chap_password_att         = -1;
static int hf_nas_ip_add_att            = -1;
static int hf_nas_port_att              = -1;
static int hf_service_type_att          = -1;
static int hf_framed_protocol_att       = -1;
static int hf_framed_address_att        = -1;
static int hf_framed_netmask_att        = -1;
static int hf_framed_routing_att        = -1;
static int hf_framed_filter_att         = -1;
static int hf_framed_mtu_att            = -1;
static int hf_framed_compression_att    = -1;
static int hf_called_station_att        = -1;
static int hf_calling_station_att       = -1;
static int hf_nas_identifier_att        = -1;
static int hf_accounting_att            = -1;
static int hf_acct_session_id_att       = -1;
static int hf_chap_challenge_att        = -1;
static int hf_nas_port_type_att         = -1;
static int hf_designation_num_att       = -1;
static int hf_nas_port_id_att           = -1;
static int hf_smc_aaa_id_att            = -1;
static int hf_smc_vpn_id_att            = -1;
static int hf_smc_vpn_name_att          = -1;
static int hf_smc_ran_id_att            = -1;
static int hf_smc_ran_ip_att            = -1;
static int hf_smc_ran_name_att          = -1;
static int hf_smc_pop_id_att            = -1;
static int hf_smc_pop_name_att          = -1;
static int hf_smc_id_att                = -1;
static int hf_smc_receive_time_att      = -1;
static int hf_smc_stat_time_att         = -1;
static int hf_opsi_flags_att            = -1;
static int hf_opsi_application_name_att = -1;
static int hf_opsi_attribute_length = -1;

/* Initialize the subtree pointers */
static gint ett_opsi                    = -1;
static gint ett_opsi_user_name          = -1;
static gint ett_opsi_user_password      = -1;
static gint ett_opsi_chap_password      = -1;
static gint ett_opsi_nas_ip_address     = -1;
static gint ett_opsi_nas_port           = -1;
static gint ett_opsi_service_type       = -1;
static gint ett_opsi_framed_protocol    = -1;
static gint ett_opsi_framed_address     = -1;
static gint ett_opsi_framed_netmask     = -1;
static gint ett_opsi_framed_routing     = -1;
static gint ett_opsi_framed_filter      = -1;
static gint ett_opsi_framed_mtu         = -1;
static gint ett_opsi_framed_compression = -1;
static gint ett_opsi_called_station_id  = -1;
static gint ett_opsi_calling_station_id = -1;
static gint ett_opsi_nas_identifier     = -1;
static gint ett_opsi_accounting         = -1;
static gint ett_opsi_acct_session_id    = -1;
static gint ett_opsi_chap_challenge     = -1;
static gint ett_opsi_nas_port_type      = -1;
static gint ett_opsi_designation_number = -1;
static gint ett_opsi_nas_port_id        = -1;
static gint ett_opsi_smc_aaa_id         = -1;
static gint ett_opsi_smc_vpn_id         = -1;
static gint ett_opsi_smc_vpn_name       = -1;
static gint ett_opsi_smc_ran_id         = -1;
static gint ett_opsi_smc_ran_ip         = -1;
static gint ett_opsi_smc_ran_name       = -1;
static gint ett_opsi_smc_pop_id         = -1;
static gint ett_opsi_smc_pop_name       = -1;
static gint ett_opsi_smc_id             = -1;
static gint ett_opsi_smc_receive_time   = -1;
static gint ett_opsi_smc_stat_time      = -1;
static gint ett_opsi_flags              = -1;
static gint ett_opsi_application_name   = -1;

static expert_field ei_opsi_unknown_attribute = EI_INIT;
static expert_field ei_opsi_short_attribute = EI_INIT;
static expert_field ei_opsi_short_frame = EI_INIT;

/* Code mapping */
static const value_string opsi_opcode[] = {
        { DISCOVER_REQUEST,  "Discover Request" },
        { DISCOVER_RESPONSE, "Discover Response" },
        { SERVICE_REQUEST,   "Service Request" },
        { SERVICE_ACCEPT,    "Service Accept" },
        { SERVICE_REJECT,    "Service Reject" },
        { TERMINATE_REQUEST, "Terminate Request" },
        { 0, NULL }
};

static const value_string opsi_service_type_code[] = {
        { 1, "Login" },
        { 2, "Framed" },
        { 3, "Callback Login" },
        { 4, "Callback Framed" },
        { 5, "Outbound" },
        { 6, "Administrative" },
        { 7, "NAS Prompt" },
        { 8, "Authenticate Only" },
        { 9, "Callback NAS Prompt" },
        { 0, NULL }
};

static const value_string opsi_framed_protocol_code[] = {
        {   1, "PPP" },
        {   2, "SLIP" },
        {   3, "AppleTalk Remote Access Protocol (ARAP)" },
        {   4, "Gandalf proprietary SingleLink/MultiLink protocol" },
        {   5, "Xylogics proprietary IPX/SLIP" },
        { 255, "Ascend ARA" },
        { 256, "MPP" },
        { 257, "EURAW" },
        { 258, "EUUI" },
        { 259, "X25" },
        { 260, "COMB" },
        { 261, "FR" },
        { 262, "MP" },
        { 263, "FR-CIR"},
        { 0, NULL }
};

static const value_string opsi_framed_routing_code[] = {
        { 0, "None" },
        { 1, "Broadcast" },
        { 2, "Listen" },
        { 3, "Broadcast-Listen" },
        { 4, "Broadcast V2" },
        { 5, "Listen V2" },
        { 6, "Broadcast-Listen V2" },
        { 0, NULL },
};

static const value_string opsi_framed_compression_code[] = {
        { 0, "None" },
        { 1, "Van Jacobsen TCP/IP" },
        { 2, "IPX header compression" },
        { 0, NULL }
};

static const value_string opsi_nas_port_type_code[] = {
        {   0, "Async" },
        {   1, "Sync" },
        {   2, "ISDN Sync" },
        {   3, "ISDN Async V.120" },
        {   4, "ISDN Async V.110" },
        {   5, "Virtual" },
        {   6, "PIAFS" },
        {   7, "HDLC Clear Channel" },
        {   8, "X.25" },
        {   9, "X.75" },
        {  10, "G.3 Fax" },
        {  11, "SDSL - Symmetric DSL" },
        {  12, "ADSL-CAP - Asymmetric DSL, Carrierless Amplitude Phase Modulation" },
        {  13, "ADSL-DMT - Asymmetric DSL, Discrete Multi-Tone" },
        {  14, "IDSL - ISDN Digital Subscriber Line" },
        {  15, "Ethernet" },
        {  16, "xDSL - Digital Subscriber Line of unknown type" },
        {  17, "Cable" },
        {  18, "Wireless - Other" },
        {  19, "Wireless - IEEE 802.11" },
        { 201, "Voice over IP" },
        { 0, NULL }
};


/* Structure used to decode OPSI frame attributes       */
/* CAUTION : it is compulsory to sort this array        */
/* (first argument of the opsi_attribute_handle_t)      */
/* in ascending order                                   */
/*                                                      */
static opsi_attribute_handle_t opsi_attributes[] = {
        { USER_NAME_ATTRIBUTE,            /* 1 */
        "User name attribute",             &ett_opsi_user_name, &hf_user_name_att, decode_string_attribute },
        { USER_PASSWD_ATTRIBUTE,          /* 2 */
        "User password attribute" ,        &ett_opsi_user_password, &hf_password_att, decode_string_attribute },
        { CHAP_PASSWD_ATTRIBUTE,          /* 3 */
        "CHAP password attribute",         &ett_opsi_chap_password, &hf_chap_password_att, decode_string_attribute },
        { NAS_IP_ADDRESS_ATTRIBUTE,       /* 4 */
        "NAS IP address attribute",        &ett_opsi_nas_ip_address, &hf_nas_ip_add_att, decode_ipv4_attribute },
        {NAS_PORT_ATTRIBUTE,              /* 5 */
        "NAS port attribute",              &ett_opsi_nas_port, &hf_nas_port_att, decode_longint_attribute },
        {SERVICE_TYPE_ATTRIBUTE,          /* 6 */
        "Service type attribute",          &ett_opsi_service_type, &hf_service_type_att, decode_value_string_attribute },
        {FRAMED_PROTOCOL_ATTRIBUTE,       /* 7 */
        "Framed protocol attribute",       &ett_opsi_framed_protocol, &hf_framed_protocol_att, decode_value_string_attribute },
        {FRAMED_ADDRESS_ATTRIBUTE,        /* 8 */
        "Framed address attribute",        &ett_opsi_framed_address, &hf_framed_address_att, decode_ipv4_attribute },
        {FRAMED_NETMASK_ATTRIBUTE,        /* 9 */
        "Framed netmask attribute",        &ett_opsi_framed_netmask, &hf_framed_netmask_att, decode_ipv4_attribute },
        {FRAMED_ROUTING_ATTRIBUTE,        /* 10 */
        "Framed routing attribute",        &ett_opsi_framed_routing, &hf_framed_routing_att, decode_value_string_attribute },
        {FRAMED_FILTER_ATTRIBUTE,         /* 11 */
        "Framed filter attribute",         &ett_opsi_framed_filter, &hf_framed_filter_att, decode_string_attribute },
        {FRAMED_MTU_ATTRIBUTE,            /* 12 */
        "Framed MTU attribute",            &ett_opsi_framed_mtu, &hf_framed_mtu_att, decode_longint_attribute },
        {FRAMED_COMPRESSION_ATTRIBUTE,    /* 13 */
        "Framed compression attribute",    &ett_opsi_framed_compression, &hf_framed_compression_att, decode_value_string_attribute },
        {CALLED_STATION_ID_ATTRIBUTE,     /* 30 */
        "Called station ID attribute",     &ett_opsi_called_station_id, &hf_called_station_att, decode_string_attribute },
        {CALLING_STATION_ID_ATTRIBUTE,    /* 31 */
        "Calling station ID attribute",    &ett_opsi_calling_station_id, &hf_calling_station_att, decode_string_attribute },
        {NAS_IDENTIFIER,                  /* 32 */
        "NAS Identifier attribute",        &ett_opsi_nas_identifier, &hf_nas_identifier_att, decode_string_attribute },
        {ACCOUNTING_40_ATTRIBUTE,         /* 40 */
        "Accounting attribute",            &ett_opsi_accounting, &hf_accounting_att, decode_string_attribute },
        {ACCOUNTING_41_ATTRIBUTE,         /* 41 */
        "Accounting attribute",            &ett_opsi_accounting, &hf_accounting_att, decode_string_attribute },
        {ACCOUNTING_42_ATTRIBUTE,         /* 42 */
        "Accounting attribute",            &ett_opsi_accounting, &hf_accounting_att, decode_string_attribute },
        {ACCOUNTING_43_ATTRIBUTE,         /* 43 */
        "Accounting attribute",            &ett_opsi_accounting, &hf_accounting_att, decode_string_attribute },
        {ACCOUNTING_SESSION_ID_ATTRIBUTE, /* 44 */
        "Accounting session ID attribute", &ett_opsi_acct_session_id, &hf_acct_session_id_att, decode_string_attribute },
        {ACCOUNTING_45_ATTRIBUTE,         /* 45 */
        "Accounting attribute",            &ett_opsi_accounting, &hf_accounting_att, decode_string_attribute },
        {ACCOUNTING_46_ATTRIBUTE,         /* 46 */
        "Accounting attribute",            &ett_opsi_accounting, &hf_accounting_att, decode_string_attribute },
        {ACCOUNTING_47_ATTRIBUTE,         /* 47 */
        "Accounting attribute",            &ett_opsi_accounting, &hf_accounting_att, decode_string_attribute },
        {ACCOUNTING_48_ATTRIBUTE,         /* 48 */
        "Accounting attribute",            &ett_opsi_accounting, &hf_accounting_att, decode_string_attribute },
        {ACCOUNTING_49_ATTRIBUTE,         /* 49 */
        "Accounting attribute",            &ett_opsi_accounting, &hf_accounting_att, decode_string_attribute },
        {ACCOUNTING_50_ATTRIBUTE,         /* 50 */
        "Accounting attribute",            &ett_opsi_accounting, &hf_accounting_att, decode_string_attribute },
        {ACCOUNTING_51_ATTRIBUTE,         /* 51 */
        "Accounting attribute",            &ett_opsi_accounting, &hf_accounting_att, decode_string_attribute },
        {ACCOUNTING_52_ATTRIBUTE,         /* 52 */
        "Accounting attribute",            &ett_opsi_accounting, &hf_accounting_att, decode_string_attribute },
        {ACCOUNTING_53_ATTRIBUTE,         /* 53 */
        "Accounting attribute",            &ett_opsi_accounting, &hf_accounting_att, decode_string_attribute },
        {ACCOUNTING_54_ATTRIBUTE,         /* 54 */
        "Accounting attribute",            &ett_opsi_accounting, &hf_accounting_att, decode_string_attribute },
        {ACCOUNTING_55_ATTRIBUTE,         /* 55 */
        "Accounting attribute",            &ett_opsi_accounting, &hf_accounting_att, decode_string_attribute },
        {ACCOUNTING_56_ATTRIBUTE,         /* 56 */
        "Accounting attribute",            &ett_opsi_accounting, &hf_accounting_att, decode_string_attribute },
        {ACCOUNTING_57_ATTRIBUTE,         /* 57 */
        "Accounting attribute",            &ett_opsi_accounting, &hf_accounting_att, decode_string_attribute },
        {ACCOUNTING_58_ATTRIBUTE,         /* 58 */
        "Accounting attribute",            &ett_opsi_accounting, &hf_accounting_att, decode_string_attribute },
        {ACCOUNTING_59_ATTRIBUTE,         /* 59 */
        "Accounting attribute",            &ett_opsi_accounting, &hf_accounting_att, decode_string_attribute },
        {CHAP_CHALLENGE_ATTRIBUTE,        /* 60 */
        "CHAP challenge",                  &ett_opsi_chap_challenge, &hf_chap_challenge_att, decode_string_attribute },
        {NAS_PORT_TYPE_ATTRIBUTE,         /* 61 */
        "NAS port type attribute",         &ett_opsi_nas_port_type, &hf_nas_port_type_att, decode_value_string_attribute },
        {DESIGNATION_NUMBER_ATTRIBUTE,    /* 77 */
        "Designation number attribute",    &ett_opsi_designation_number, &hf_designation_num_att, decode_string_attribute },
        {NAS_PORT_ID_ATTRIBUTE,           /* 87 */
        "NAS port ID attribute",           &ett_opsi_nas_port_id, &hf_nas_port_id_att, decode_string_attribute },
        {SMC_AAAID_ATTRIBUTE,             /* 651 */
        "SMC AAA ID attribute",            &ett_opsi_smc_aaa_id, &hf_smc_aaa_id_att, decode_longint_attribute },
        {SMC_VPNID_ATTRIBUTE,             /* 652 */
        "SMC VPN ID attribute",            &ett_opsi_smc_vpn_id, &hf_smc_vpn_id_att, decode_longint_attribute },
        {SMC_VPNNAME_ATTRIBUTE,           /* 653 */
        "SMC VPN name attribute",          &ett_opsi_smc_vpn_name, &hf_smc_vpn_name_att, decode_string_attribute },
        {SMC_RANID_ATTRIBUTE,             /* 654 */
        "SMC RAN ID attribute",            &ett_opsi_smc_ran_id, &hf_smc_ran_id_att, decode_longint_attribute },
        {SMC_RANIP_ATTRIBUTE,             /* 655 */
        "SMC RAN IP attribute",            &ett_opsi_smc_ran_ip, &hf_smc_ran_ip_att, decode_ipv4_attribute },
        {SMC_RANNAME_ATTRIBUTE,           /* 656 */
        "SMC RAN name attribute",          &ett_opsi_smc_ran_name, &hf_smc_ran_name_att, decode_string_attribute },
        {SMC_POPID_ATTRIBUTE,             /* 657 */
        "SMC POP ID attribute",            &ett_opsi_smc_pop_id, &hf_smc_pop_id_att, decode_longint_attribute },
        {SMC_POPNAME_ATTRIBUTE,           /* 658 */
        "SMC POP name attribute",          &ett_opsi_smc_pop_name, &hf_smc_pop_name_att, decode_string_attribute },
        {SMC_SMCID_ATTRIBUTE,             /* 659 */
        "SMC ID attribute",                &ett_opsi_smc_id, &hf_smc_id_att, decode_longint_attribute },
        {SMC_RECEIVE_TIME_ATTRIBUTE,      /* 660 */
        "SMC receive time attribute",      &ett_opsi_smc_receive_time, &hf_smc_receive_time_att, decode_time_attribute },
        {SMC_STAT_TIME_ATTRIBUTE,         /* 661 */
        "SMC stat time attribute",         &ett_opsi_smc_stat_time, &hf_smc_stat_time_att, decode_longint_attribute },
        {OPSI_FLAGS_ATTRIBUTE,            /* 674 */
        "OPSI flags attribute",            &ett_opsi_flags, &hf_opsi_flags_att, decode_longint_attribute },
        {OPSI_APPLICATION_NAME_ATTRIBUTE, /* 675 */
        "OPSI application name attribute", &ett_opsi_application_name, &hf_opsi_application_name_att, decode_string_attribute },

};
#define OPSI_ATTRIBUTES_COUNT (sizeof(opsi_attributes)/sizeof(opsi_attribute_handle_t))

/* Desegmentation of OPSI (over TCP) */
static gboolean opsi_desegment = TRUE;

static void
decode_string_attribute(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, proto_item *item, int* hfValue, int offset, int length)
{
        if (length < 4) {
                expert_add_info(pinfo, item, &ei_opsi_short_attribute);
                return;
        }

        proto_tree_add_item(tree, *hfValue, tvb, offset+4, length-4, ENC_ASCII|ENC_NA);
}


static void
decode_ipv4_attribute(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, proto_item *item, int* hfValue, int offset, int length)
{
        if (length < 8) {
                expert_add_info(pinfo, item, &ei_opsi_short_attribute);
                return;
        }
        proto_tree_add_item(tree, *hfValue, tvb, offset+4, 4, ENC_BIG_ENDIAN);
}

static void
decode_longint_attribute(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, proto_item *item, int* hfValue, int offset, int length)
{
        if (length < 8) {
                expert_add_info(pinfo, item, &ei_opsi_short_attribute);
                return;
        }
        proto_tree_add_item(tree, *hfValue, tvb, offset+4, 4, ENC_BIG_ENDIAN);
}

static void
decode_value_string_attribute(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, proto_item *item, int* hfValue, int offset, int length)
{
        if (length < 8) {
                expert_add_info(pinfo, item, &ei_opsi_short_attribute);
                return;
        }
        proto_tree_add_item(tree, *hfValue, tvb, offset+4, 4, ENC_BIG_ENDIAN);
}

static void
decode_time_attribute(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, proto_item *item, int* hfValue, int offset, int length)
{
        nstime_t ns;

        if (length < 8) {
                expert_add_info(pinfo, item, &ei_opsi_short_attribute);
                return;
        }
        ns.secs  = tvb_get_ntohl(tvb, offset+4);
        ns.nsecs = 0;
        proto_tree_add_time(tree, *hfValue, tvb, offset+4, 4, &ns);
}

/****************************************************************************/
/********** End of attribute decoding ***************************************/
/****************************************************************************/

/* To find the correct size of the PDU. Needed by the desegmentation feature*/
static guint
get_opsi_pdu_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offset, void *data _U_)
{
        /*
         * Get the length of the OPSI packet.
         * We are guaranteed there're enough chars in tvb in order to
         * extract the length value. No exception thrown !!
         */
        return tvb_get_ntohs(tvb, offset + 4);
}

static int
get_opsi_attribute_index(int min, int max, int attribute_type)
{
        int middle, at;

        middle = (min+max)/2;
        at = opsi_attributes[middle].attribute_type;
        if (at == attribute_type) return middle;
        if (attribute_type > at) {
                return (middle == max) ? -1 : get_opsi_attribute_index(middle+1, max, attribute_type);
        }
        return (middle == min) ? -1 : get_opsi_attribute_index(min, middle-1, attribute_type);
}


static void
dissect_attributes(tvbuff_t *tvb, packet_info *pinfo, proto_tree *opsi_tree, int offset, int length)
{
        int i;
        int attribute_type;
        int attribute_length;
        proto_item *ti;
        proto_tree *ntree = NULL;

        while (length >= 4) {
                attribute_type          = tvb_get_ntohs(tvb, offset);
                attribute_length        = tvb_get_ntohs(tvb, offset+2);
                if (attribute_length > length) break;
                /* We perform a standard log(n) lookup */
                i = get_opsi_attribute_index(0, OPSI_ATTRIBUTES_COUNT-1, attribute_type);
                if (i == -1) {
                        proto_tree_add_expert_format(opsi_tree, pinfo, &ei_opsi_unknown_attribute, tvb, offset, attribute_length,
                                                                                "Unknown attribute (%d)", attribute_type);
                }
                else {
                        ntree = proto_tree_add_subtree_format(opsi_tree, tvb, offset, attribute_length, *opsi_attributes[i].tree_id, &ti,
                                                                                                                        "%s (%d)", opsi_attributes[i].tree_text, attribute_type);
                        proto_tree_add_item(ntree, hf_opsi_attribute_length, tvb, offset+2, 2, ENC_BIG_ENDIAN);
                        opsi_attributes[i].dissect(tvb, pinfo, ntree, ti, opsi_attributes[i].hf_type_attribute, offset, attribute_length);
                }
                if (attribute_length < 4) {
                        /* Length must be at least 4, for the type and length. */
                        break;
                }
                offset += attribute_length;
                length -= attribute_length;
        }
        if (length) {
                proto_tree_add_expert(opsi_tree, pinfo, &ei_opsi_short_frame, tvb, offset, -1);
        }
}

static int
dissect_opsi_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
        proto_item *ti;
        proto_tree *opsi_tree;

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

        col_append_sep_fstr(pinfo->cinfo, COL_INFO, ", ", "%s",
                val_to_str(tvb_get_guint8(tvb, CODE_OFFSET), opsi_opcode,
                        "<Unknown opcode %d>"));
        col_set_fence(pinfo->cinfo, COL_INFO);

        ti = proto_tree_add_item(tree, proto_opsi, tvb, 0, -1, ENC_NA);
        opsi_tree = proto_item_add_subtree(ti, ett_opsi);

        if (opsi_tree) {
                proto_tree_add_item(opsi_tree, hf_opsi_major_version, tvb, MAJOR_VERSION_OFFSET, 1, ENC_BIG_ENDIAN);
                proto_tree_add_item(opsi_tree, hf_opsi_minor_version, tvb, MINOR_VERSION_OFFSET, 1, ENC_BIG_ENDIAN);
                proto_tree_add_item(opsi_tree, hf_opsi_opcode, tvb, CODE_OFFSET, 1, ENC_BIG_ENDIAN);
                proto_tree_add_item(opsi_tree, hf_opsi_hook_id, tvb, HOOK_ID_OFFSET, 1, ENC_BIG_ENDIAN);
                proto_tree_add_item(opsi_tree, hf_opsi_length, tvb, PACKET_LENGTH_OFFSET, 2, ENC_BIG_ENDIAN);
                proto_tree_add_item(opsi_tree, hf_opsi_session_id, tvb, SESSION_OFFSET, 2, ENC_BIG_ENDIAN);
        }

        dissect_attributes(tvb, pinfo, opsi_tree, HEADER_LENGTH, MIN(((int)tvb_reported_length(tvb)-HEADER_LENGTH), (tvb_get_ntohs(tvb, PACKET_LENGTH_OFFSET)-HEADER_LENGTH)));
        return tvb_reported_length(tvb);
}


static int
dissect_opsi(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data)
{
        /* We should mimimally grab the header */
        tcp_dissect_pdus(tvb, pinfo, tree, opsi_desegment, HEADER_LENGTH, get_opsi_pdu_len,
                dissect_opsi_pdu, data);
        return tvb_reported_length(tvb);
}


void
proto_register_opsi(void)
{

/* Setup list of header fields  See Section 1.6.1 for details*/
        static hf_register_info hf[] = {
                { &hf_opsi_major_version,
                        { "Major version",           "opsi.major",
                        FT_UINT8, BASE_DEC, NULL, 0x0,
                        NULL, HFILL }
                },
                { &hf_opsi_minor_version,
                        { "Minor version",           "opsi.minor",
                        FT_UINT8, BASE_DEC, NULL, 0x0,
                        NULL, HFILL }
                },
                { &hf_opsi_opcode,
                        { "Operation code",             "opsi.opcode",
                        FT_UINT8, BASE_DEC, VALS(opsi_opcode), 0x0,
                        NULL, HFILL }
                },
                { &hf_opsi_hook_id,
                        { "Hook ID",                    "opsi.hook",
                        FT_UINT8, BASE_DEC, NULL, 0x0,
                        NULL, HFILL }
                },
                { &hf_opsi_length,
                        { "Message length",             "opsi.length",
                        FT_UINT16, BASE_DEC, NULL, 0x0,
                        NULL, HFILL }
                },
                { &hf_opsi_session_id,
                        { "Session ID",                 "opsi.session_id",
                        FT_UINT16, BASE_DEC, NULL, 0x0,
                        NULL, HFILL }
                },
                { &hf_user_name_att,
                        { "User name",                  "opsi.attr.user_name",
                        FT_STRING, BASE_NONE, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_password_att,
                        { "User password",              "opsi.attr.password",
                        FT_STRING, BASE_NONE, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_chap_password_att,
                        { "CHAP password attribute",    "opsi.attr.chap_password",
                        FT_STRING, BASE_NONE, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_nas_ip_add_att,
                        { "NAS IP address",             "opsi.attr.nas_ip_addr",
                        FT_IPv4, BASE_NONE, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_nas_port_att,
                        { "NAS port",                   "opsi.attr.nas_port",
                        FT_UINT32, BASE_HEX, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_service_type_att,
                        { "Service type",               "opsi.attr.service_type",
                        FT_UINT32, BASE_DEC, VALS(opsi_service_type_code), 0x0,
                        NULL, HFILL }
                },
                { &hf_framed_protocol_att,
                        { "Framed protocol",            "opsi.attr.framed_protocol",
                        FT_UINT32, BASE_DEC, VALS(opsi_framed_protocol_code), 0x0,
                        NULL, HFILL }
                },
                { &hf_framed_address_att,
                        { "Framed address",             "opsi.attr.framed_address",
                        FT_IPv4, BASE_NONE, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_framed_netmask_att,
                        { "Framed netmask",             "opsi.attr.framed_netmask",
                        FT_IPv4, BASE_NETMASK, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_framed_routing_att,
                        { "Framed routing",             "opsi.attr.framed_routing",
                        FT_UINT32, BASE_DEC, VALS(opsi_framed_routing_code), 0x0,
                        NULL, HFILL }
                },
                { &hf_framed_filter_att,
                        { "Framed filter",              "opsi.attr.framed_filter",
                        FT_STRING, BASE_NONE, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_framed_mtu_att,
                        { "Framed MTU",         "opsi.attr.framed_mtu",
                        FT_UINT32, BASE_DEC, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_framed_compression_att,
                        { "Framed compression",         "opsi.attr.framed_compression",
                        FT_UINT32, BASE_DEC, VALS(opsi_framed_compression_code), 0x0,
                        NULL, HFILL }
                },
                { &hf_called_station_att,
                        { "Called station ID",          "opsi.attr.called_station_id",
                        FT_STRING, BASE_NONE, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_calling_station_att,
                        { "Calling station ID",         "opsi.attr.calling_station_id",
                        FT_STRING, BASE_NONE, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_nas_identifier_att,
                        { "NAS ID",                     "opsi.attr.nas_id",
                        FT_STRING, BASE_NONE, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_accounting_att,
                        { "Accounting",                 "opsi.attr.accounting",
                        FT_STRING, BASE_NONE, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_acct_session_id_att,
                        { "Accounting session ID",      "opsi.attr.acct.session_id",
                        FT_STRING, BASE_NONE, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_chap_challenge_att,
                        { "CHAP challenge",             "opsi.attr.chap_challenge",
                        FT_STRING, BASE_NONE, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_nas_port_type_att,
                        { "NAS port type",              "opsi.attr.nas_port_type",
                        FT_UINT32, BASE_DEC, VALS(opsi_nas_port_type_code), 0x0,
                        NULL, HFILL }
                },
                { &hf_designation_num_att,
                        { "Designation number",         "opsi.attr.designation_number",
                        FT_STRING, BASE_NONE, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_nas_port_id_att,
                        { "NAS port ID",                "opsi.attr.nas_port_id",
                        FT_STRING, BASE_NONE, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_smc_aaa_id_att,
                        { "SMC AAA ID",                 "opsi.attr.smc_aaa_id",
                        FT_UINT32, BASE_DEC, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_smc_vpn_id_att,
                        { "SMC VPN ID",                 "opsi.attr.smc_vpn_id",
                        FT_UINT32, BASE_DEC, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_smc_vpn_name_att,
                        { "SMC VPN name",               "opsi.attr.smc_vpn_name",
                        FT_STRING, BASE_NONE, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_smc_ran_id_att,
                        { "SMC RAN ID",                 "opsi.attr.smc_ran_id",
                        FT_UINT32, BASE_DEC, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_smc_ran_ip_att,
                        { "SMC RAN IP address",         "opsi.attr.smc_ran_ip",
                        FT_IPv4, BASE_NONE, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_smc_ran_name_att,
                        { "SMC RAN name",               "opsi.attr.smc_ran_name",
                        FT_STRING, BASE_NONE, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_smc_pop_id_att,
                        { "SMC POP id",                 "opsi.attr.smc_pop_id",
                        FT_UINT32, BASE_DEC, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_smc_pop_name_att,
                        { "SMC POP name",               "opsi.attr.smc_pop_name",
                        FT_STRING, BASE_NONE, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_smc_id_att,
                        { "SMC ID",                     "opsi.attr.smc_id",
                        FT_UINT32, BASE_DEC, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_smc_receive_time_att,
                        { "SMC receive time",           "opsi.attr.smc_receive_time",
                        FT_ABSOLUTE_TIME, ABSOLUTE_TIME_LOCAL, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_smc_stat_time_att,
                        { "SMC stat time",              "opsi.attr.smc_stat_time",
                        FT_UINT32, BASE_DEC, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_opsi_flags_att,
                        { "OPSI flags",                 "opsi.attr.flags",
                        FT_UINT32, BASE_DEC, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_opsi_application_name_att,
                        { "OPSI application name",      "opsi.attr.application_name",
                        FT_STRING, BASE_NONE, NULL, 0x00,
                        NULL, HFILL }
                },
                { &hf_opsi_attribute_length,
                        { "Length",     "opsi.attr_length",
                        FT_UINT16, BASE_DEC, NULL, 0x00,
                        NULL, HFILL }
                },
        };

/* Setup protocol subtree array */
        static gint *ett[] = {
                &ett_opsi,
                &ett_opsi_user_name,
                &ett_opsi_user_password,
                &ett_opsi_chap_password,
                &ett_opsi_nas_ip_address,
                &ett_opsi_nas_port,
                &ett_opsi_service_type,
                &ett_opsi_framed_protocol,
                &ett_opsi_framed_address,
                &ett_opsi_framed_netmask,
                &ett_opsi_framed_routing,
                &ett_opsi_framed_filter,
                &ett_opsi_framed_mtu,
                &ett_opsi_framed_compression,
                &ett_opsi_called_station_id,
                &ett_opsi_calling_station_id,
                &ett_opsi_nas_identifier,
                &ett_opsi_accounting,
                &ett_opsi_acct_session_id,
                &ett_opsi_chap_challenge,
                &ett_opsi_nas_port_type,
                &ett_opsi_designation_number,
                &ett_opsi_nas_port_id,
                &ett_opsi_smc_aaa_id,
                &ett_opsi_smc_vpn_id,
                &ett_opsi_smc_vpn_name,
                &ett_opsi_smc_ran_id,
                &ett_opsi_smc_ran_ip,
                &ett_opsi_smc_ran_name,
                &ett_opsi_smc_pop_id,
                &ett_opsi_smc_pop_name,
                &ett_opsi_smc_id,
                &ett_opsi_smc_receive_time,
                &ett_opsi_smc_stat_time,
                &ett_opsi_flags,
                &ett_opsi_application_name,
        };

        static ei_register_info ei[] = {
                { &ei_opsi_unknown_attribute, { "opsi.attr_unknown", PI_PROTOCOL, PI_WARN, "Unknown attribute", EXPFILL }},
                { &ei_opsi_short_attribute, { "opsi.attr_too_short", PI_MALFORMED, PI_WARN, "Too short attribute!", EXPFILL }},
                { &ei_opsi_short_frame, { "opsi.short_frame", PI_MALFORMED, PI_WARN, "Short frame", EXPFILL }},
        };

/* For desegmentation / reassembly */
        module_t *opsi_module;
        expert_module_t* expert_opsi;

/* Register the protocol name and description */
        proto_opsi = proto_register_protocol("Open Policy Service Interface",
            "OPSI", "opsi");

/* Required function calls to register the header fields and subtrees used */
        proto_register_field_array(proto_opsi, hf, array_length(hf));
        proto_register_subtree_array(ett, array_length(ett));
        expert_opsi = expert_register_protocol(proto_opsi);
        expert_register_field_array(expert_opsi, ei, array_length(ei));

/* We activate the desegmentation / reassembly feature */
        opsi_module = prefs_register_protocol(proto_opsi, NULL);
        prefs_register_bool_preference(opsi_module, "desegment_opsi_messages",
                "Reassemble OPSI messages spanning multiple TCP segments",
                "Whether the OPSI dissector should desegment all messages spanning multiple TCP segments",
                &opsi_desegment);
}


void
proto_reg_handoff_opsi(void)
{
        dissector_handle_t opsi_handle;
        opsi_handle = create_dissector_handle(dissect_opsi, proto_opsi);
        dissector_add_uint("tcp.port", TCP_PORT_OPSI, opsi_handle);
}

/*
 * Editor modelines  -  http://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:
 */