/* packet-fc-sb3.c
 * Routines for Fibre Channel Single Byte Protocol (SBCCS); used in FICON.
 * This decoder is for FC-SB3 version 1.4
 * Copyright 2003, Dinesh G Dutt <ddutt@cisco.com>
 *
 * $Id: packet-fcsb3.c,v 1.3 2003/12/18 00:28:39 guy Exp $
 *
 * Ethereal - Network traffic analyzer
 * By Gerald Combs <gerald@ethereal.com>
 * Copyright 1998 Gerald Combs
 *
 * Copied from WHATEVER_FILE_YOU_USED (where "WHATEVER_FILE_YOU_USED"
 * is a dissector file; if you just copied this from README.developer,
 * don't bother with the "Copied from" - you don't even need to put
 * in a "Copied from" if you copied an existing dissector, especially
 * if the bulk of the code in the new dissector is your code)
 * 
 * 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif

#ifdef HAVE_NETINET_IN_H
# include <netinet/in.h>
#endif

#include <glib.h>

#ifdef NEED_SNPRINTF_H
# include "snprintf.h"
#endif

#include "prefs.h"
#include <epan/packet.h>
#include <epan/conversation.h>
#include "etypes.h"
#include "packet-fc.h"
#include "packet-fcsb3.h"

/* Initialize the protocol and registered fields */
static int proto_fc_sbccs             = -1;
static int hf_sbccs_chid              = -1;
static int hf_sbccs_cuid              = -1;
static int hf_sbccs_devaddr           = -1;
static int hf_sbccs_iui               = -1;
static int hf_sbccs_dhflags           = -1;
static int hf_sbccs_ccw               = -1;
static int hf_sbccs_token             = -1;
static int hf_sbccs_dib_iucnt         = -1;
static int hf_sbccs_dib_datacnt       = -1;
static int hf_sbccs_dib_ccw_cmd       = -1;
static int hf_sbccs_dib_ccw_flags     = -1;
static int hf_sbccs_dib_ccw_cnt       = -1;
static int hf_sbccs_dib_statusflags   = -1;
static int hf_sbccs_dib_status        = -1;
static int hf_sbccs_dib_residualcnt   = -1;
static int hf_sbccs_dib_qtuf          = -1;
static int hf_sbccs_dib_qtu           = -1;
static int hf_sbccs_dib_dtuf          = -1;
static int hf_sbccs_dib_dtu           = -1;
static int hf_sbccs_dib_ctlfn         = -1;
static int hf_sbccs_dib_ctlparam      = -1;
static int hf_sbccs_lrc               = -1;
static int hf_sbccs_dib_iupacing      = -1;
static int hf_sbccs_dev_xcp_code      = -1;
static int hf_sbccs_prg_pth_errcode   = -1;
static int hf_sbccs_prg_rsp_errcode   = -1;
static int hf_sbccs_dib_ctccntr       = -1;
static int hf_sbccs_dib_lprcode       = -1;
static int hf_sbccs_dib_tin_imgid_cnt = -1;
static int hf_sbccs_dib_lrjcode       = -1;
static int hf_sbccs_dib_ioprio        = -1;
static int hf_sbccs_dib_cmdflags      = -1;
static int hf_sbccs_dib_linkctlfn     = -1;
static int hf_sbccs_dib_linkctlinfo   = -1;

/* Initialize the subtree pointers */
static gint ett_fc_sbccs = -1;

static dissector_handle_t data_handle;

typedef struct {
    guint32 conv_id;
    guint32 task_id;
} sb3_task_id_t;

static const value_string fc_sbccs_iu_val[] = {
    {FC_SBCCS_IU_DATA,            "Data"},
    {FC_SBCCS_IU_CMD_HDR,         "Command Header"},
    {FC_SBCCS_IU_STATUS,          "Status"},
    {FC_SBCCS_IU_CTL,             "Control"},
    {FC_SBCCS_IU_CMD_DATA,        "Command Header & Data"},
    {FC_SBCCS_IU_CMD_LINK_CTL,    "Link Control"},
    {0x6,                         "Reserved"},
    {0x7,                         "Reserved"},
    {0x0,                         NULL},
};

static const value_string fc_sbccs_dib_cmd_val[] = {
    {0,  "Reserved"},
    {1,  "Write"},
    {2,  "Read"},
    {3,  "Control"},
    {4,  "Sense"},
    {5,  "Write (Modifier)"},
    {6,  "Read (Modifier)"},
    {7,  "Control (Modifier)"},
    {8,  "Reserved"},
    {9,  "Write (Modifier)"},
    {10, "Read (Modifier)"},
    {11, "Control (Modifier)"},
    {12, "Read Backward"},
    {13, "Write (Modifier)"},
    {14, "Read (Modifier)"},
    {15, "Control (Modifier)"},
    {0, NULL},
};

static const value_string fc_sbccs_dib_ctl_fn_val[] = {
    {FC_SBCCS_CTL_FN_CTL_END,   "Control End"},
    {FC_SBCCS_CTL_FN_CMD_RSP,   "Command Response"},
    {FC_SBCCS_CTL_FN_STK_STS,   "Stack Status"},
    {FC_SBCCS_CTL_FN_CANCEL,    "Cancel"},
    {FC_SBCCS_CTL_FN_SYS_RST,   "System Reset"},
    {FC_SBCCS_CTL_FN_SEL_RST,   "Selective Reset"},
    {FC_SBCCS_CTL_FN_REQ_STS,   "Request Status"},
    {FC_SBCCS_CTL_FN_DEV_XCP,   "Device Level Exception"},
    {FC_SBCCS_CTL_FN_STS_ACC,   "Status Accepted"},
    {FC_SBCCS_CTL_FN_DEV_ACK,   "Device-Level Ack"},
    {FC_SBCCS_CTL_FN_PRG_PTH,   "Purge Path"},
    {FC_SBCCS_CTL_FN_PRG_RSP,   "Purge Path Response"},
    {0, NULL},
};

static const value_string fc_sbccs_dib_dev_xcpcode_val[] = {
    {1, "Address Exception"},
    {0, NULL},
};

static const value_string fc_sbccs_dib_purge_path_err_val[] = {
    {0, "Error Code Xfer Not Supported"},
    {1, "SB-3 Protocol Timeout"},
    {2, "SB-3 Link Failure"},
    {3, "Reserved"},
    {4, "SB-3 Offline Condition"},
    {5, "FC-PH Link Failure"},
    {6, "SB-3 Length Error"},
    {7, "LRC Error"},
    {8, "SB-3 CRC Error"},
    {9, "IU Count Error"},
    {10, "SB-3 Link Level Protocol Error"},
    {11, "SB-3 Device Level Protocol Error"},
    {12, "Receive ABTS"},
    {13, "Cancel Function Timeout"},
    {14, "Abnormal Termination of Xchg"},
    {15, "Reserved"},
    {0,  NULL},
};

static const value_string fc_sbccs_dib_purge_path_rsp_err_val[] = {
    {0, "No Errors"},
    {1, "SB-3 Protocol Timeout"},
    {2, "SB-3 Link Failure"},
    {3, "Logical Path Timeout Error"},
    {4, "SB-3 Offline Condition"},
    {5, "FC-PH Link Failure"},
    {6, "SB-3 Length Error"},
    {7, "LRC Error"},
    {8, "SB-3 CRC Error"},
    {9, "IU Count Error"},
    {10, "SB-3 Link Level Protocol Error"},
    {11, "SB-3 Device Level Protocol Error"},
    {12, "Receive ABTS"},
    {13, "Reserved"},
    {14, "Abnormal Termination of Xchg"},
    {15, "Logical Path Not Estd"},
    {16, "Test Init Result Error"},
    {0,  NULL},
};

static const value_string fc_sbccs_dib_link_ctl_fn_val[] = {
    {FC_SBCCS_LINK_CTL_FN_ELP, "ELP"},
    {FC_SBCCS_LINK_CTL_FN_RLP, "RLP"},
    {FC_SBCCS_LINK_CTL_FN_TIN, "TIN"},
    {FC_SBCCS_LINK_CTL_FN_LPE, "LPE"},
    {FC_SBCCS_LINK_CTL_FN_LPR, "LPR"},
    {FC_SBCCS_LINK_CTL_FN_TIR, "TIR"},
    {FC_SBCCS_LINK_CTL_FN_LRJ, "LRJ"},
    {FC_SBCCS_LINK_CTL_FN_LBY, "LBY"},
    {FC_SBCCS_LINK_CTL_FN_LACK, "LACK"},
    {0, NULL},
};

static const value_string fc_sbccs_dib_lpr_errcode_val[] = {
    {0x0, "Response to RLP"},
    {0x1, "Optional Features Conflict"},
    {0x2, "Out of Resources"},
    {0x3, "Device Init In Progress"},
    {0x4, "No CU Image"},
    {0x0, NULL},
};

static const value_string fc_sbccs_dib_lrj_errcode_val[] = {
    {0x6, "Logical Path Not Estd"},
    {0x9, "Protocol Error"},
    {0x0, NULL},
};

static gchar *get_iui_string (guint8 iui, gchar *buffer)
{
    guint pos = 0;
    buffer[0] = '\0';

    if (iui & 0x10) {
        strcpy (&buffer[pos], "AS, ");
        pos += 4;
    }

    if (iui & 0x8) {
        strcpy (&buffer[pos], "ES, ");
        pos += 4;
    }

    strcpy (&buffer[pos], val_to_str (iui & 0x7, fc_sbccs_iu_val, "0x%x"));

    return (buffer);
}

static gchar *get_dhflags_string (guint8 dhflags, gchar *buffer)
{
    guint pos = 0;
    buffer[0] = '\0';

    if (dhflags & 0x80) {
        strcpy (&buffer[pos], "End, ");
        pos += 5;
    }

    if (dhflags & 0x10) {
        strcpy (&buffer[pos], "Chaining, ");
        pos += 10;
    }

    if (dhflags & 0x8) {
        strcpy (&buffer[pos], "Early End, ");
        pos += 11;
    }

    if (dhflags & 0x4) {
        strcpy (&buffer[pos], "No CRC");
    }

    return (buffer);
}

static gchar *get_ccw_flags_string (guint8 ccw_flags, gchar *buffer)
{
    guint pos = 0;
    
    buffer[0] = '\0';

    if (ccw_flags & 0x80) {
        strcpy (&buffer[pos], "CD, ");
        pos += 4;
    }

    if (ccw_flags & 0x40) {
        strcpy (&buffer[pos], "CC, ");
        pos += 4;
    }

    if (ccw_flags & 0x20) {
        strcpy (&buffer[pos], "SLI, ");
        pos += 5;
    }

    if (ccw_flags & 0x8) {
        strcpy (&buffer[pos], "CRR");
        pos += 5;
    }

    return (buffer);
}

static gchar *get_cmd_flag_string (guint8 cmd_flag, gchar *buffer)
{
    guint pos = 0;

    buffer[0] = '\0';

    if (cmd_flag & 0x10) {
        strcpy (&buffer[pos], "DU, ");
        pos += 4;
    }

    if (cmd_flag & 0x8) {
        strcpy (&buffer[pos], "COC, ");
        pos += 4;
    }

    if (cmd_flag & 0x4) {
        strcpy (&buffer[pos], "SYR, ");
        pos += 5;
    }

    if (cmd_flag & 0x2) {
        strcpy (&buffer[pos], "REX, ");
        pos += 5;
    }

    if (cmd_flag & 0x1) {
        strcpy (&buffer[pos], "SSS");
        pos += 5;
    }

    return (buffer);
}

static gchar *get_status_flag_string (guint8 status_flag, gchar *buffer)
{
    guint pos = 0;
    guint8 ffc = (status_flag & 0xD0) >> 5;

    buffer[0] = '\0';

    switch (ffc) {
    case 0:
        break;                  /* to avoid the catch clause below */
    case 1:
        strcpy (&buffer[pos], "FFC:Queuing Information Valid, ");
        pos += 31;
        break;
    case 2:
        strcpy (&buffer[pos], "FFC:Resetting Event, ");
        pos += 21;
        break;
    default:
        strcpy (&buffer[pos], "Reserved");
        break;
    }

    if (status_flag & 10) {
        strcpy (&buffer[pos], "CI, ");
        pos += 4;
    }

    if (status_flag & 0x4) {
        strcpy (&buffer[pos], "CR, ");
        pos += 4;
    }

    if (status_flag & 0x2) {
        strcpy (&buffer[pos], "LRI, ");
        pos += 5;
    }

    if (status_flag & 0x1) {
        strcpy (&buffer[pos], "RV");
    }

    return (buffer);
}

static gchar *get_status_string (guint8 status, gchar *buffer)
{
    guint pos = 0;

    buffer[0] = '\0';

    if (status & 0x80) {
        strcpy (&buffer[pos], "Attention, ");
        pos += 11;
    }

    if (status & 0x40) {
        strcpy (&buffer[pos], "Status Modifier, ");
        pos += 17;
    }

    if (status & 0x20) {
        strcpy (&buffer[pos], "Control-Unit End, ");
        pos += 18;
    }

    if (status & 0x10) {
        strcpy (&buffer[pos], "Busy, ");
        pos += 6;
    }

    if (status & 0x8) {
        strcpy (&buffer[pos], "Channel End, ");
        pos += 12;
    }

    if (status & 0x4) {
        strcpy (&buffer[pos], "Device End, ");
        pos += 12;
    }

    if (status & 0x2) {
        strcpy (&buffer[pos], "Unit Check, ");
        pos += 12;
    }

    if (status & 0x1) {
        strcpy (&buffer[pos], "Unit Exception");
    }

    return (buffer);
}

static gchar *get_sel_rst_param_string (guint8 ctlparam, gchar *buffer)
{
    guint pos = 0;

    buffer[0] = '\0';

    if (ctlparam & 0x80) {
        strcpy (&buffer[pos], "RC, ");
        pos += 4;
    }
    if (ctlparam & 0x10) {
        strcpy (&buffer[pos], "RU, ");
        pos += 4;
    }
    if (ctlparam & 0x8) {
        strcpy (&buffer[pos], "RO");
    }

    return (buffer);
}

static void get_fc_sbccs_conv_data (tvbuff_t *tvb, guint offset,
                                    guint16 *ch_cu_id, guint16 *dev_addr,
                                    guint16 *ccw)
{
    *ch_cu_id = *dev_addr = *ccw = 0;

    *ch_cu_id = (tvb_get_guint8 (tvb, offset+1)) << 8;
    *ch_cu_id |= tvb_get_guint8 (tvb, offset+3);
    *dev_addr = tvb_get_ntohs (tvb, offset+4);
    *ccw = tvb_get_ntohs (tvb, offset+10);
}

/* Decode both the SB-3 and basic IU header */
static void
dissect_fc_sbccs_sb3_iu_hdr (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
                             guint offset)
{
    proto_item *subti;
    proto_tree *sb3hdr_tree;
    proto_tree *iuhdr_tree;
    gchar buffer[256];
    guint8 iui, dhflags;
    guint type;
    
    /* Decode the basic SB3 and IU header and determine type of frame */
    type = get_fc_sbccs_iu_type (tvb, offset);

    if (check_col (pinfo->cinfo, COL_INFO)) {
        col_set_str (pinfo->cinfo, COL_INFO, val_to_str (type, fc_sbccs_iu_val,
                                                         "0x%x"));
    }
    
    if (tree) {
        /* Dissect SB3 header first */
        subti = proto_tree_add_text (tree, tvb, offset, FC_SBCCS_SB3_HDR_SIZE,
                                     "SB-3 Header");
        sb3hdr_tree = proto_item_add_subtree (subti, ett_fc_sbccs);

        proto_tree_add_item (sb3hdr_tree, hf_sbccs_chid, tvb, offset+1, 1, 0);
        proto_tree_add_item (sb3hdr_tree, hf_sbccs_cuid, tvb, offset+3, 1, 0);
        proto_tree_add_item (sb3hdr_tree, hf_sbccs_devaddr, tvb, offset+4, 2, 0);

        /* Dissect IU Header */
        subti = proto_tree_add_text (tree, tvb, offset + FC_SBCCS_SB3_HDR_SIZE,
                                     FC_SBCCS_IU_HDR_SIZE, "IU Header");
        iuhdr_tree = proto_item_add_subtree (subti, ett_fc_sbccs);
        offset += FC_SBCCS_SB3_HDR_SIZE;

        iui = tvb_get_guint8 (tvb, offset);
        proto_tree_add_uint_format (iuhdr_tree, hf_sbccs_iui, tvb, offset, 1,
                                    iui, "Information Unit Identifier: 0x%x (%s)",
                                    iui, get_iui_string (iui, buffer));
        dhflags = tvb_get_guint8 (tvb, offset+1);
        proto_tree_add_uint_format (iuhdr_tree, hf_sbccs_dhflags, tvb, offset, 1,
                                    dhflags, "DH Flags: 0x%x (%s)",
                                    dhflags, get_dhflags_string (dhflags, buffer));
        
        proto_tree_add_item (iuhdr_tree, hf_sbccs_ccw, tvb, offset+2, 2, 0);
        proto_tree_add_item (iuhdr_tree, hf_sbccs_token, tvb, offset+5, 3, 0);
    }
}

static void dissect_fc_sbccs_dib_data_hdr (tvbuff_t *tvb,
                                           packet_info *pinfo _U_,
                                           proto_tree *tree, guint offset)
{
    if (tree) {
        proto_tree_add_item (tree, hf_sbccs_dib_iucnt, tvb, offset+9, 1, 0);
        proto_tree_add_item (tree, hf_sbccs_dib_datacnt, tvb, offset+10, 2, 0);
        proto_tree_add_item (tree, hf_sbccs_lrc, tvb, offset+12, 4, 0);
    }
}

static void dissect_fc_sbccs_dib_cmd_hdr (tvbuff_t *tvb, packet_info *pinfo,
                                          proto_tree *tree, guint offset)
{
    guint8 flags;
    gchar buffer[64];

    if (check_col (pinfo->cinfo, COL_INFO)) {
        col_append_fstr (pinfo->cinfo, COL_INFO,
                         ": %s", val_to_str (tvb_get_guint8 (tvb, offset),
                                             fc_sbccs_dib_cmd_val,
                                             "0x%x"));
    }
    
    if (tree) {
        proto_tree_add_item (tree, hf_sbccs_dib_ccw_cmd, tvb, offset, 1, 0);

        flags = tvb_get_guint8 (tvb, offset+1);
        proto_tree_add_uint_format (tree, hf_sbccs_dib_ccw_flags, tvb,
                                    offset+1, 1, flags,
                                    "CCW Control Flags: 0x%x(%s)", flags,
                                    get_ccw_flags_string (flags, buffer));
        proto_tree_add_item (tree, hf_sbccs_dib_ccw_cnt, tvb, offset+2, 2, 0);
        proto_tree_add_item (tree, hf_sbccs_dib_ioprio, tvb, offset+5, 1, 0);

        flags = tvb_get_guint8 (tvb, offset+7);
        proto_tree_add_uint_format (tree, hf_sbccs_dib_cmdflags, tvb, offset+7,
                                    1, flags, "Command Flags: 0x%x(%s)", flags,
                                    get_cmd_flag_string (flags, buffer));
        proto_tree_add_item (tree, hf_sbccs_dib_iucnt, tvb, offset+9, 1, 0);
        proto_tree_add_item (tree, hf_sbccs_dib_datacnt, tvb, offset+10, 2, 0);
        proto_tree_add_item (tree, hf_sbccs_lrc, tvb, offset+12, 4, 0);

    }
}

static void dissect_fc_sbccs_dib_status_hdr (tvbuff_t *tvb, packet_info *pinfo,
                                             proto_tree *tree, guint offset)
{
    guint8 flags;
    gboolean rv_valid, qparam_valid;
    gchar buffer[128];
    tvbuff_t *next_tvb;
    guint16 supp_status_cnt = 0;

    if (check_col (pinfo->cinfo, COL_INFO)) {
        col_append_fstr (pinfo->cinfo, COL_INFO,
                         ": %s",
                         get_status_string (tvb_get_guint8 (tvb, offset+1),
                                            buffer));
    }
    
    if (tree) {
        flags = tvb_get_guint8 (tvb, offset);
        rv_valid = flags & 0x1; /* if residual count is valid */
        qparam_valid = (((flags & 0xD0) >> 5) == 0x1); /* From the FFC field */
        proto_tree_add_uint_format (tree, hf_sbccs_dib_statusflags, tvb, offset,
                                    1, flags, "Status Flags: 0x%x(%s)",
                                    flags, get_status_flag_string (flags,
                                                                   buffer));
        
        flags = tvb_get_guint8 (tvb, offset+1);
        proto_tree_add_uint_format (tree, hf_sbccs_dib_status, tvb, offset+1,
                                    1, flags, "Status: 0x%x(%s)", flags,
                                    get_status_string (flags, buffer));
        if (rv_valid) {
            proto_tree_add_item (tree, hf_sbccs_dib_residualcnt, tvb, offset+2,
                                 2, 0);
        }
        else {
            proto_tree_add_item (tree, hf_sbccs_dib_iupacing, tvb, offset+3,
                                 1, 0);
        }
        
        if (qparam_valid) {
            proto_tree_add_item (tree, hf_sbccs_dib_qtuf, tvb, offset+4, 1, 0);
            proto_tree_add_item (tree, hf_sbccs_dib_qtu, tvb, offset+4, 2, 0);
        }

        proto_tree_add_item (tree, hf_sbccs_dib_dtuf, tvb, offset+6, 1, 0);
        proto_tree_add_item (tree, hf_sbccs_dib_dtu, tvb, offset+6, 2, 0);

        proto_tree_add_item (tree, hf_sbccs_dib_iucnt, tvb, offset+9, 1, 0);
        proto_tree_add_item (tree, hf_sbccs_dib_datacnt, tvb, offset+10, 2, 0);
        supp_status_cnt = tvb_get_ntohs (tvb, offset+10);
        proto_tree_add_item (tree, hf_sbccs_lrc, tvb, offset+12, 4, 0);

        if (supp_status_cnt) {
            next_tvb = tvb_new_subset (tvb, offset+FC_SBCCS_DIB_LRC_HDR_SIZE,
                                       -1, -1);
            call_dissector (data_handle, next_tvb, pinfo, tree);
        }
    }
}

static void dissect_fc_sbccs_dib_ctl_hdr (tvbuff_t *tvb, packet_info *pinfo,
                                          proto_tree *tree, guint offset)
{
    guint8 ctlfn;
    gchar buffer[128];

    ctlfn = tvb_get_guint8 (tvb, offset);
    if (check_col (pinfo->cinfo, COL_INFO)) {
        col_append_fstr (pinfo->cinfo, COL_INFO,
                         ": %s",
                         val_to_str (ctlfn, 
                                     fc_sbccs_dib_ctl_fn_val,
                                     "0x%x"));
    }
    if (tree) {
        proto_tree_add_item (tree, hf_sbccs_dib_ctlfn, tvb, offset, 1, 0);

        /* Control Function Parameter is to be interpreted in some cases */
        switch (ctlfn) {
        case FC_SBCCS_CTL_FN_SEL_RST:
            proto_tree_add_uint_format (tree, hf_sbccs_dib_ctlparam, tvb,
                                        offset+1, 3,
                                        tvb_get_ntoh24 (tvb, offset+1),
                                        "Control Parameter: 0x%x(%s)",
                                        tvb_get_ntoh24 (tvb, offset+1),
                                        get_sel_rst_param_string (ctlfn,
                                                                  buffer));
            break;
        case FC_SBCCS_CTL_FN_DEV_XCP:
            proto_tree_add_item (tree, hf_sbccs_dev_xcp_code, tvb, offset+1,
                                 1, 0);
            break;
        case FC_SBCCS_CTL_FN_PRG_PTH:
            proto_tree_add_item (tree, hf_sbccs_prg_pth_errcode, tvb, offset+1,
                                 1, 0);
            break;
        default:
            proto_tree_add_item (tree, hf_sbccs_dib_ctlparam, tvb, offset+1,
                                 3, 0);
            break;
        }
        
        proto_tree_add_item (tree, hf_sbccs_dib_iucnt, tvb, offset+9, 1, 0);
        proto_tree_add_item (tree, hf_sbccs_dib_datacnt, tvb, offset+10, 2, 0);
        proto_tree_add_item (tree, hf_sbccs_lrc, tvb, offset+12, 4, 0);

        if (ctlfn == FC_SBCCS_CTL_FN_PRG_RSP) {
            /* Need to decode the LESBs */
            proto_tree_add_item (tree, hf_sbccs_prg_rsp_errcode, tvb, offset+60,
                                 1, 0);
        }
    }
}

static void dissect_fc_sbccs_dib_link_hdr (tvbuff_t *tvb, packet_info *pinfo,
                                           proto_tree *tree, guint offset)
{
    guint8 link_ctl;
    guint16 ctl_info;
    gchar buffer[128];
    guint link_payload_len, i;
    gchar *lpath_ptr;

    if (check_col (pinfo->cinfo, COL_INFO)) {
        col_append_fstr (pinfo->cinfo, COL_INFO,
                         ": %s",
                         val_to_str (tvb_get_guint8 (tvb, offset+1),
                                     fc_sbccs_dib_link_ctl_fn_val,
                                     "0x%x"));
    }

    if (tree) {
        link_ctl = tvb_get_guint8 (tvb, offset+1);
        proto_tree_add_item (tree, hf_sbccs_dib_linkctlfn, tvb, offset+1, 1, 0);

        ctl_info = tvb_get_ntohs (tvb, offset+2);
        switch (link_ctl) {
        case FC_SBCCS_LINK_CTL_FN_ELP:
        case FC_SBCCS_LINK_CTL_FN_LPE:
            buffer[0] = '\0';
            if (ctl_info & 0x1) {
                strcpy (buffer, "Enhanced CRC Gen, ");
            }
            if (ctl_info & 0x80) {
                strcpy (&buffer[18], "CTC Conn");
            }

            proto_tree_add_uint_format (tree, hf_sbccs_dib_linkctlinfo, tvb,
                                        offset+2, 2, ctl_info,
                                        "Link Control Info: 0x%x(%s)", ctl_info,
                                        buffer);
            break;
        case FC_SBCCS_LINK_CTL_FN_LPR:
            proto_tree_add_item (tree, hf_sbccs_dib_lprcode, tvb, offset+2, 1,
                                 0);
            break;
        case FC_SBCCS_LINK_CTL_FN_TIN:
            proto_tree_add_item (tree, hf_sbccs_dib_tin_imgid_cnt, tvb,
                                 offset+3, 1, 0);
            break;
        case FC_SBCCS_LINK_CTL_FN_TIR:
            proto_tree_add_item (tree, hf_sbccs_dib_tin_imgid_cnt, tvb,
                                 offset+3, 1, 0);
            break;
        case FC_SBCCS_LINK_CTL_FN_LRJ:
            proto_tree_add_item (tree, hf_sbccs_dib_lrjcode, tvb, offset+2,
                                 1, 0);
            break;
        default:
            /* Do Nothing */
            break;
        }

        proto_tree_add_item (tree, hf_sbccs_dib_ctccntr, tvb, offset+4, 2, 0);
        proto_tree_add_item (tree, hf_sbccs_dib_iucnt, tvb, offset+9, 1, 0);
        proto_tree_add_item (tree, hf_sbccs_dib_datacnt, tvb, offset+10, 2, 0);
        proto_tree_add_item (tree, hf_sbccs_lrc, tvb, offset+12, 4, 0);

        if (link_ctl == FC_SBCCS_LINK_CTL_FN_TIR) {
            link_payload_len = tvb_get_ntohs (tvb, offset+10);
            i = 0;
            offset += 16;
            lpath_ptr = (gchar *)tvb_get_ptr (tvb, offset, link_payload_len/4);
            
            while (i < link_payload_len) {
                proto_tree_add_text (tree, tvb, offset, 4,
                                     "Logical Paths %d-%d: %x:%x:%x:%x",
                                     i*8, ((i+4)*8) - 1, lpath_ptr[i],
                                     lpath_ptr[i+1], lpath_ptr[i+2],
                                     lpath_ptr[i+3]);
                i += 4;
                offset += 4;
            }
        }
    }
}

static void dissect_fc_sbccs (tvbuff_t *tvb, packet_info *pinfo,
                              proto_tree *tree)
{
    guint8 type;
    guint16 ch_cu_id, dev_addr, ccw;
    guint offset = 0; 
    proto_item *ti;
    proto_tree *sb3_tree = NULL,
               *dib_tree = NULL;
    tvbuff_t *next_tvb;
    conversation_t *conversation;
    sb3_task_id_t task_key;
        
    /* Make entries in Protocol column and Info column on summary display */
    if (check_col(pinfo->cinfo, COL_PROTOCOL)) 
        col_set_str(pinfo->cinfo, COL_PROTOCOL, "FC-SB3");

    /* Decode the basic SB3 and IU header and determine type of frame */
    type = get_fc_sbccs_iu_type (tvb, offset);
    get_fc_sbccs_conv_data (tvb, offset, &ch_cu_id, &dev_addr, &ccw);

    if (check_col (pinfo->cinfo, COL_INFO)) {
        col_set_str (pinfo->cinfo, COL_INFO, val_to_str (type, fc_sbccs_iu_val,
                                                         "0x%x"));
    }
    
    /* Retrieve conversation state to determine expected payload */
    conversation = find_conversation (&pinfo->src, &pinfo->dst,
                                      PT_SBCCS, ch_cu_id, dev_addr, 0);
                                      
    if (conversation) {
        task_key.conv_id = conversation->index;
        task_key.task_id = ccw;
        pinfo->private_data = (void *)&task_key;

    }
    else if ((type == FC_SBCCS_IU_CMD_HDR) || 
             (type != FC_SBCCS_IU_CMD_DATA)) {
        conversation = conversation_new (&pinfo->src, &pinfo->dst,
                                         PT_SBCCS, ch_cu_id, dev_addr, 0);
        task_key.conv_id = conversation->index;
        task_key.task_id = ccw;
        pinfo->private_data = (void *)&task_key;
    }
    else {
        pinfo->private_data = NULL;
    }
    
    if (tree) {
        ti = proto_tree_add_protocol_format (tree, proto_fc_sbccs, tvb, 0, -1,
                                             "FC-SB3");
        sb3_tree = proto_item_add_subtree (ti, ett_fc_sbccs);

        dissect_fc_sbccs_sb3_iu_hdr (tvb, pinfo, sb3_tree, offset);
        offset += (FC_SBCCS_SB3_HDR_SIZE + FC_SBCCS_IU_HDR_SIZE);

        ti = proto_tree_add_text (sb3_tree, tvb, offset,
                                  FC_SBCCS_DIB_LRC_HDR_SIZE, "DIB Header");
        dib_tree = proto_item_add_subtree (ti, ett_fc_sbccs);
    }
    else {
        offset += (FC_SBCCS_SB3_HDR_SIZE + FC_SBCCS_IU_HDR_SIZE);
    }
    
    switch (type) {
    case FC_SBCCS_IU_DATA:
        dissect_fc_sbccs_dib_data_hdr (tvb, pinfo, dib_tree, offset);
        break;
    case FC_SBCCS_IU_CMD_HDR:
    case FC_SBCCS_IU_CMD_DATA:
        dissect_fc_sbccs_dib_cmd_hdr (tvb, pinfo, dib_tree, offset);
        break;
    case FC_SBCCS_IU_STATUS:
        dissect_fc_sbccs_dib_status_hdr (tvb, pinfo, dib_tree, offset);
        break;
    case FC_SBCCS_IU_CTL:
        dissect_fc_sbccs_dib_ctl_hdr (tvb, pinfo, dib_tree, offset);
        break;
    case FC_SBCCS_IU_CMD_LINK_CTL:
        dissect_fc_sbccs_dib_link_hdr (tvb, pinfo, dib_tree, offset);
        break;
    default:
        next_tvb = tvb_new_subset (tvb, offset, -1, -1);
        call_dissector (data_handle, next_tvb, pinfo, dib_tree);
        break;
    }

    if ((get_fc_sbccs_iu_type (tvb, 0) != FC_SBCCS_IU_CTL) &&
        (get_fc_sbccs_iu_type (tvb, 0) != FC_SBCCS_IU_CMD_LINK_CTL))  {
        next_tvb = tvb_new_subset (tvb, offset+FC_SBCCS_DIB_LRC_HDR_SIZE,
                                   -1, -1);
        call_dissector (data_handle, next_tvb, pinfo, tree);
    }
}

/* Register the protocol with Ethereal */

/* this format is required because a script is used to build the C function
   that calls all the protocol registration.
*/

void
proto_register_fcsbccs (void)
{                 
    /* Setup list of header fields  See Section 1.6.1 for details*/
    static hf_register_info hf[] = {
        { &hf_sbccs_chid,
          {"Channel Image ID", "sbccs.chid", FT_UINT8, BASE_DEC, NULL, 0x0,
           "", HFILL}},
        { &hf_sbccs_cuid,
          {"Control Unit Image ID", "sbccs.cuid", FT_UINT8, BASE_DEC, NULL,
           0x0, "", HFILL}},
        { &hf_sbccs_devaddr,
          {"Device Address", "sbccs.devaddr", FT_UINT16, BASE_DEC, NULL, 0x0,
           "", HFILL}},
        { &hf_sbccs_iui,
          {"Information Unit Identifier", "sbccs.iui", FT_UINT8, BASE_HEX,
           NULL, 0x0, "", HFILL}},
        { &hf_sbccs_dhflags,
          {"DH Flags", "sbccs.dhflags", FT_UINT8, BASE_HEX, NULL, 0x0, "",
           HFILL}},
        { &hf_sbccs_ccw,
          {"CCW Number", "sbccs.ccw", FT_UINT16, BASE_HEX, NULL, 0x0, "",
           HFILL}},
        { &hf_sbccs_token,
          {"Token", "sbccs.token", FT_UINT24, BASE_DEC, NULL, 0x0, "",
           HFILL}},
        { &hf_sbccs_dib_iucnt,
          {"DIB IU Count", "sbccs.iucnt", FT_UINT8, BASE_DEC, NULL, 0x0,
           "", HFILL}},
        { &hf_sbccs_dib_datacnt,
          {"DIB Data Byte Count", "sbccs.databytecnt", FT_UINT16, BASE_DEC,
           NULL, 0x0, "", HFILL}},
        { &hf_sbccs_dib_ccw_cmd,
          {"CCW Command", "sbccs.ccwcmd", FT_UINT8, BASE_HEX,
           VALS (fc_sbccs_dib_cmd_val), 0x0, "", HFILL}},
        { &hf_sbccs_dib_ccw_flags,
          {"CCW Control Flags", "sbccs.ccwflags", FT_UINT8, BASE_HEX, NULL,
           0x0, "", HFILL}},
        { &hf_sbccs_dib_ccw_cnt,
          {"CCW Count", "sbccs.ccwcnt", FT_UINT16, BASE_DEC, NULL, 0x0, "",
           HFILL}},
        { &hf_sbccs_dib_ioprio,
          {"I/O Priority", "sbccs.ioprio", FT_UINT8, BASE_DEC, NULL, 0x0,
           "", HFILL}},
        { &hf_sbccs_dib_cmdflags,
          {"Command Flags", "sbccs.cmdflags", FT_UINT8, BASE_HEX, NULL, 0x0,
           "", HFILL}},
        { &hf_sbccs_dib_statusflags,
          {"Status Flags", "sbccs.statusflags", FT_UINT8, BASE_HEX, NULL,
           0x0, "", HFILL}},
        { &hf_sbccs_dib_status,
          {"Status", "sbccs.status", FT_UINT8, BASE_DEC, NULL, 0x0, "",
           HFILL}},
        { &hf_sbccs_dib_residualcnt,
          {"Residual Count", "sbccs.residualcnt", FT_UINT8, BASE_DEC,
           NULL, 0x0, "", HFILL}},
        { &hf_sbccs_dib_iupacing,
          {"IU Pacing", "sbccs.iupacing", FT_UINT8, BASE_DEC, NULL, 0x0,
           "", HFILL}},
        { &hf_sbccs_dib_qtuf,
          {"Queue-Time Unit Factor", "sbccs.qtuf", FT_UINT8, BASE_DEC,
           NULL, 0xF0, "", HFILL}},
        { &hf_sbccs_dib_qtu,
          {"Queue-Time Unit", "sbccs.qtu", FT_UINT16, BASE_DEC, NULL, 0xFFF,
           "", HFILL}},
        { &hf_sbccs_dib_dtuf,
          {"Defer-Time Unit Function", "sbccs.dtuf", FT_UINT8, BASE_DEC,
           NULL, 0xF0, "", HFILL}},
        { &hf_sbccs_dib_dtu,
          {"Defer-Time Unit", "sbccs.dtu", FT_UINT16, BASE_DEC, NULL, 0xFFF,
           "", HFILL}},
        { &hf_sbccs_dib_ctlfn,
          {"Control Function", "sbccs.ctlfn", FT_UINT8, BASE_HEX,
           VALS (fc_sbccs_dib_ctl_fn_val), 0x0, "", HFILL}},
        { &hf_sbccs_dib_ctlparam,
          {"Control Parameters", "sbccs.ctlparam", FT_UINT24, BASE_HEX,
           NULL, 0x0, "", HFILL}},
        { &hf_sbccs_dib_linkctlfn,
          {"Link Control Function", "sbccs.linkctlfn", FT_UINT8, BASE_HEX,
           VALS (fc_sbccs_dib_link_ctl_fn_val), 0x0, "", HFILL}},
        { &hf_sbccs_dib_linkctlinfo,
          {"Link Control Information", "sbccs.linkctlinfo", FT_UINT16,
           BASE_HEX, NULL, 0x0, "", HFILL}},
        { &hf_sbccs_dib_ctccntr,
          {"CTC Counter", "sbccs.ctccntr", FT_UINT16, BASE_DEC, NULL, 0x0,
           "", HFILL}},
        { &hf_sbccs_lrc,
          {"LRC", "sbccs.lrc", FT_UINT32, BASE_HEX, NULL, 0x0, "", HFILL}},
        { &hf_sbccs_dev_xcp_code,
          {"Device Level Exception Code", "sbccs.dip.xcpcode", FT_UINT8,
           BASE_DEC, VALS (fc_sbccs_dib_dev_xcpcode_val), 0x0, "", HFILL}},
        { &hf_sbccs_prg_pth_errcode,
          {"Purge Path Error Code", "sbccs.purgepathcode", FT_UINT8,
           BASE_DEC, VALS (fc_sbccs_dib_purge_path_err_val), 0x0, "", HFILL}},
        { &hf_sbccs_prg_rsp_errcode,
          {"Purge Path Response Error Code", "sbccs.purgepathrspcode",
           FT_UINT8, BASE_DEC, VALS (fc_sbccs_dib_purge_path_rsp_err_val),
           0x0, "", HFILL}},
        { &hf_sbccs_dib_lprcode,
          {"LPR Reason Code", "sbccs.lprcode", FT_UINT8, BASE_DEC,
           VALS (fc_sbccs_dib_lpr_errcode_val), 0xF, "", HFILL}},
        { &hf_sbccs_dib_tin_imgid_cnt,
          {"TIN Image ID", "sbccs.tinimageidcnt", FT_UINT8, BASE_DEC, NULL,
           0x0, "", HFILL}},
        { &hf_sbccs_dib_lrjcode,
          {"LRJ Reaspn Code", "sbccs.lrjcode", FT_UINT8, BASE_HEX,
           VALS (fc_sbccs_dib_lrj_errcode_val), 0x7F, "", HFILL}},
    };


    /* Setup protocol subtree array */
    static gint *ett[] = {
        &ett_fc_sbccs,
    };

    /* Register the protocol name and description */
    proto_fc_sbccs = proto_register_protocol ("Fibre Channel Single Byte Command",
                                              "FC-SB3", "sb3");

    /* Required function calls to register the header fields and subtrees used */
    proto_register_field_array(proto_fc_sbccs, hf, array_length(hf));
    proto_register_subtree_array(ett, array_length(ett));
}

/* If this dissector uses sub-dissector registration add a registration routine.
   This format is required because a script is used to find these routines and
   create the code that calls these routines.
*/
void
proto_reg_handoff_fcsbccs (void)
{
    dissector_handle_t fc_sbccs_handle;

    fc_sbccs_handle = create_dissector_handle (dissect_fc_sbccs,
                                               proto_fc_sbccs);

    dissector_add("fc.ftype", FC_FTYPE_SBCCS, fc_sbccs_handle);

    data_handle = find_dissector ("data");
}