/src/wireshark/epan/dissectors/packet-sna.c

Source
/* packet-sna.c
 * Routines for SNA
 * Gilbert Ramirez <gram@alumni.rice.edu>
 * Jochen Friedrich <jochen@scram.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>
#include <epan/address_types.h>
#include <epan/prefs.h>
#include <epan/reassemble.h>
#include <epan/to_str.h>
#include <epan/tfs.h>
#include <wsutil/array.h>
#include "wsutil/pint.h"
#include "packet-ppp.h"
#include "packet-llc.h"

/*
 * See:
 *
 * http://web.archive.org/web/20020206033700/http://www.wanresources.com/snacell.html
 *
 * http://web.archive.org/web/20150522015710/http://www.protocols.com/pbook/sna.htm
 *
 * Systems Network Architecture Formats, GA27-3136-20:
 * https://publibfp.dhe.ibm.com/epubs/pdf/d50a5007.pdf
 *
 * Systems Network Architecture Management Services Formats, GC31-8302-03:
 * https://publibfp.boulder.ibm.com/cgi-bin/bookmgr/BOOKS/d50x4002/CCONTENTS
 */
void proto_register_sna(void);
void proto_reg_handoff_sna(void);

static int proto_sna;
static int proto_sna_xid;
static int hf_sna_th;
static int hf_sna_th_0;
static int hf_sna_th_fid;
static int hf_sna_th_mpf;
static int hf_sna_th_odai;
static int hf_sna_th_efi;
static int hf_sna_th_daf;
static int hf_sna_th_oaf;
static int hf_sna_th_snf;
static int hf_sna_th_dcf;
static int hf_sna_th_lsid;
static int hf_sna_th_tg_sweep;
static int hf_sna_th_er_vr_supp_ind;
static int hf_sna_th_vr_pac_cnt_ind;
static int hf_sna_th_ntwk_prty;
static int hf_sna_th_tgsf;
static int hf_sna_th_mft;
static int hf_sna_th_piubf;
static int hf_sna_th_iern;
static int hf_sna_th_nlpoi;
static int hf_sna_th_nlp_cp;
static int hf_sna_th_ern;
static int hf_sna_th_vrn;
static int hf_sna_th_tpf;
static int hf_sna_th_vr_cwi;
static int hf_sna_th_tg_nonfifo_ind;
static int hf_sna_th_vr_sqti;
static int hf_sna_th_tg_snf;
static int hf_sna_th_vrprq;
static int hf_sna_th_vrprs;
static int hf_sna_th_vr_cwri;
static int hf_sna_th_vr_rwi;
static int hf_sna_th_vr_snf_send;
static int hf_sna_th_dsaf;
static int hf_sna_th_osaf;
static int hf_sna_th_snai;
static int hf_sna_th_def;
static int hf_sna_th_oef;
static int hf_sna_th_sa;
static int hf_sna_th_cmd_fmt;
static int hf_sna_th_cmd_type;
static int hf_sna_th_cmd_sn;
static int hf_sna_th_byte1;
static int hf_sna_th_byte2;
static int hf_sna_th_byte3;
static int hf_sna_th_byte4;
static int hf_sna_th_byte6;
static int hf_sna_th_byte16;

static int hf_sna_nlp_nhdr;
static int hf_sna_nlp_nhdr_0;
static int hf_sna_nlp_sm;
static int hf_sna_nlp_tpf;
static int hf_sna_nlp_nhdr_1;
static int hf_sna_nlp_ft;
static int hf_sna_nlp_tspi;
static int hf_sna_nlp_slowdn1;
static int hf_sna_nlp_slowdn2;
static int hf_sna_nlp_fra;
static int hf_sna_nlp_anr;
static int hf_sna_nlp_frh;
static int hf_sna_nlp_thdr;
static int hf_sna_nlp_tcid;
static int hf_sna_nlp_thdr_8;
static int hf_sna_nlp_setupi;
static int hf_sna_nlp_somi;
static int hf_sna_nlp_eomi;
static int hf_sna_nlp_sri;
static int hf_sna_nlp_rasapi;
static int hf_sna_nlp_retryi;
static int hf_sna_nlp_thdr_9;
static int hf_sna_nlp_lmi;
static int hf_sna_nlp_cqfi;
static int hf_sna_nlp_osi;
static int hf_sna_nlp_offset;
static int hf_sna_nlp_dlf;
static int hf_sna_nlp_bsn;
static int hf_sna_nlp_opti_len;
static int hf_sna_nlp_opti_type;
static int hf_sna_nlp_opti_0d_version;
static int hf_sna_nlp_opti_0d_4;
static int hf_sna_nlp_opti_0d_target;
static int hf_sna_nlp_opti_0d_arb;
static int hf_sna_nlp_opti_0d_reliable;
static int hf_sna_nlp_opti_0d_dedicated;
static int hf_sna_nlp_opti_0e_stat;
static int hf_sna_nlp_opti_0e_gap;
static int hf_sna_nlp_opti_0e_idle;
static int hf_sna_nlp_opti_0e_nabsp;
static int hf_sna_nlp_opti_0e_sync;
static int hf_sna_nlp_opti_0e_echo;
static int hf_sna_nlp_opti_0e_rseq;
/* static int hf_sna_nlp_opti_0e_abspbeg; */
/* static int hf_sna_nlp_opti_0e_abspend; */
static int hf_sna_nlp_opti_0f_bits;
static int hf_sna_nlp_opti_10_tcid;
static int hf_sna_nlp_opti_12_sense;
static int hf_sna_nlp_opti_14_si_len;
static int hf_sna_nlp_opti_14_si_key;
static int hf_sna_nlp_opti_14_si_2;
static int hf_sna_nlp_opti_14_si_refifo;
static int hf_sna_nlp_opti_14_si_mobility;
static int hf_sna_nlp_opti_14_si_dirsearch;
static int hf_sna_nlp_opti_14_si_limitres;
static int hf_sna_nlp_opti_14_si_ncescope;
static int hf_sna_nlp_opti_14_si_mnpsrscv;
static int hf_sna_nlp_opti_14_si_maxpsize;
static int hf_sna_nlp_opti_14_si_switch;
static int hf_sna_nlp_opti_14_si_alive;
static int hf_sna_nlp_opti_14_rr_len;
static int hf_sna_nlp_opti_14_rr_key;
static int hf_sna_nlp_opti_14_rr_2;
static int hf_sna_nlp_opti_14_rr_bfe;
static int hf_sna_nlp_opti_14_rr_num;
static int hf_sna_nlp_opti_22_2;
static int hf_sna_nlp_opti_22_type;
static int hf_sna_nlp_opti_22_raa;
static int hf_sna_nlp_opti_22_parity;
static int hf_sna_nlp_opti_22_arb;
static int hf_sna_nlp_opti_22_3;
static int hf_sna_nlp_opti_22_ratereq;
static int hf_sna_nlp_opti_22_raterep;
static int hf_sna_nlp_opti_22_field1;
static int hf_sna_nlp_opti_22_field2;
static int hf_sna_nlp_opti_22_field3;
static int hf_sna_nlp_opti_22_field4;

static int hf_sna_rh;
static int hf_sna_rh_0;
static int hf_sna_rh_1;
static int hf_sna_rh_2;
static int hf_sna_rh_rri;
static int hf_sna_rh_ru_category;
static int hf_sna_rh_fi;
static int hf_sna_rh_sdi;
static int hf_sna_rh_bci;
static int hf_sna_rh_eci;
static int hf_sna_rh_dr1;
static int hf_sna_rh_lcci;
static int hf_sna_rh_dr2;
static int hf_sna_rh_eri;
static int hf_sna_rh_rti;
static int hf_sna_rh_rlwi;
static int hf_sna_rh_qri;
static int hf_sna_rh_pi;
static int hf_sna_rh_bbi;
static int hf_sna_rh_ebi;
static int hf_sna_rh_cdi;
static int hf_sna_rh_csi;
static int hf_sna_rh_edi;
static int hf_sna_rh_pdi;
static int hf_sna_rh_cebi;
/*static int hf_sna_ru;*/

static int hf_sna_gds;
static int hf_sna_gds_len;
static int hf_sna_gds_type;
static int hf_sna_gds_cont;
static int hf_sna_gds_info;

/* static int hf_sna_xid; */
static int hf_sna_xid_0;
static int hf_sna_xid_id;
static int hf_sna_xid_format;
static int hf_sna_xid_type;
static int hf_sna_xid_len;
static int hf_sna_xid_idblock;
static int hf_sna_xid_idnum;
static int hf_sna_xid_3_8;
static int hf_sna_xid_3_init_self;
static int hf_sna_xid_3_stand_bind;
static int hf_sna_xid_3_gener_bind;
static int hf_sna_xid_3_recve_bind;
static int hf_sna_xid_3_actpu;
static int hf_sna_xid_3_nwnode;
static int hf_sna_xid_3_cp;
static int hf_sna_xid_3_cpcp;
static int hf_sna_xid_3_state;
static int hf_sna_xid_3_nonact;
static int hf_sna_xid_3_cpchange;
static int hf_sna_xid_3_10;
static int hf_sna_xid_3_asend_bind;
static int hf_sna_xid_3_arecv_bind;
static int hf_sna_xid_3_quiesce;
static int hf_sna_xid_3_pucap;
static int hf_sna_xid_3_pbn;
static int hf_sna_xid_3_pacing;
static int hf_sna_xid_3_11;
static int hf_sna_xid_3_tgshare;
static int hf_sna_xid_3_dedsvc;
static int hf_sna_xid_3_12;
static int hf_sna_xid_3_negcsup;
static int hf_sna_xid_3_negcomp;
static int hf_sna_xid_3_15;
static int hf_sna_xid_3_partg;
static int hf_sna_xid_3_dlur;
static int hf_sna_xid_3_dlus;
static int hf_sna_xid_3_exbn;
static int hf_sna_xid_3_genodai;
static int hf_sna_xid_3_branch;
static int hf_sna_xid_3_brnn;
static int hf_sna_xid_3_tg;
static int hf_sna_xid_3_dlc;
static int hf_sna_xid_3_dlen;

static int hf_sna_control_len;
static int hf_sna_control_key;
static int hf_sna_control_hprkey;
static int hf_sna_control_05_delay;
static int hf_sna_control_05_type;
static int hf_sna_control_05_ptp;
static int hf_sna_control_0e_type;
static int hf_sna_control_0e_value;
static int hf_sna_padding;
static int hf_sna_reserved;
static int hf_sna_biu_segment_data;

static int ett_sna;
static int ett_sna_th;
static int ett_sna_th_fid;
static int ett_sna_nlp_nhdr;
static int ett_sna_nlp_nhdr_0;
static int ett_sna_nlp_nhdr_1;
static int ett_sna_nlp_thdr;
static int ett_sna_nlp_thdr_8;
static int ett_sna_nlp_thdr_9;
static int ett_sna_nlp_opti_un;
static int ett_sna_nlp_opti_0d;
static int ett_sna_nlp_opti_0d_4;
static int ett_sna_nlp_opti_0e;
static int ett_sna_nlp_opti_0e_stat;
static int ett_sna_nlp_opti_0e_absp;
static int ett_sna_nlp_opti_0f;
static int ett_sna_nlp_opti_10;
static int ett_sna_nlp_opti_12;
static int ett_sna_nlp_opti_14;
static int ett_sna_nlp_opti_14_si;
static int ett_sna_nlp_opti_14_si_2;
static int ett_sna_nlp_opti_14_rr;
static int ett_sna_nlp_opti_14_rr_2;
static int ett_sna_nlp_opti_22;
static int ett_sna_nlp_opti_22_2;
static int ett_sna_nlp_opti_22_3;
static int ett_sna_rh;
static int ett_sna_rh_0;
static int ett_sna_rh_1;
static int ett_sna_rh_2;
static int ett_sna_gds;
static int ett_sna_xid_0;
static int ett_sna_xid_id;
static int ett_sna_xid_3_8;
static int ett_sna_xid_3_10;
static int ett_sna_xid_3_11;
static int ett_sna_xid_3_12;
static int ett_sna_xid_3_15;
static int ett_sna_control_un;
static int ett_sna_control_05;
static int ett_sna_control_05hpr;
static int ett_sna_control_05hpr_type;
static int ett_sna_control_0e;

static dissector_handle_t sna_handle;
static dissector_handle_t sna_xid_handle;

static int sna_address_type = -1;

/* Defragment fragmented SNA BIUs*/
static bool sna_defragment = true;
static reassembly_table sna_reassembly_table;

/* Format Identifier */
static const value_string sna_th_fid_vals[] = {
  { 0x0,  "SNA device <--> Non-SNA Device" },
  { 0x1,  "Subarea Nodes, without ER or VR" },
  { 0x2,  "Subarea Node <--> PU2" },
  { 0x3,  "Subarea Node or SNA host <--> Subarea Node" },
  { 0x4,  "Subarea Nodes, supporting ER and VR" },
  { 0x5,  "HPR RTP endpoint nodes" },
  { 0xa,  "HPR NLP Frame Routing" },
  { 0xb,  "HPR NLP Frame Routing" },
  { 0xc,  "HPR NLP Automatic Network Routing" },
  { 0xd,  "HPR NLP Automatic Network Routing" },
  { 0xf,  "Adjacent Subarea Nodes, supporting ER and VR" },
  { 0x0,  NULL }
};

/* Mapping Field */
#define MPF_MIDDLE_SEGMENT  0
#define MPF_LAST_SEGMENT    1
#define MPF_FIRST_SEGMENT   2
#define MPF_WHOLE_BIU       3

static const value_string sna_th_mpf_vals[] = {
  { MPF_MIDDLE_SEGMENT,   "Middle segment of a BIU" },
  { MPF_LAST_SEGMENT,     "Last segment of a BIU" },
  { MPF_FIRST_SEGMENT,    "First segment of a BIU" },
  { MPF_WHOLE_BIU,        "Whole BIU" },
  { 0,   NULL }
};

/* Expedited Flow Indicator */
static const value_string sna_th_efi_vals[] = {
  { 0, "Normal Flow" },
  { 1, "Expedited Flow" },
  { 0x0,  NULL }
};

/* Request/Response Unit Category */
static const value_string sna_rh_ru_category_vals[] = {
  { 0, "Function Management Data (FMD)" },
  { 1, "Network Control (NC)" },
  { 2, "Data Flow Control (DFC)" },
  { 3, "Session Control (SC)" },
  { 0x0,  NULL }
};

/* Format Indicator */
static const true_false_string sna_rh_fi_truth =
  { "FM Header", "No FM Header" };

/* Begin Chain Indicator */
static const true_false_string sna_rh_bci_truth =
  { "First in Chain", "Not First in Chain" };

/* End Chain Indicator */
static const true_false_string sna_rh_eci_truth =
  { "Last in Chain", "Not Last in Chain" };

/* Lengith-Checked Compression Indicator */
static const true_false_string sna_rh_lcci_truth =
  { "Compressed", "Not Compressed" };

/* Response Type Indicator */
static const true_false_string sna_rh_rti_truth =
  { "Negative", "Positive" };

/* Queued Response Indicator */
static const true_false_string sna_rh_qri_truth =
  { "Enqueue response in TC queues", "Response bypasses TC queues" };

/* Code Selection Indicator */
static const value_string sna_rh_csi_vals[] = {
  { 0, "EBCDIC" },
  { 1, "ASCII" },
  { 0x0,  NULL }
};

/* TG Sweep */
static const value_string sna_th_tg_sweep_vals[] = {
  { 0, "This PIU may overtake any PU ahead of it." },
  { 1, "This PIU does not overtake any PIU ahead of it." },
  { 0x0,  NULL }
};

/* ER_VR_SUPP_IND */
static const value_string sna_th_er_vr_supp_ind_vals[] = {
  { 0, "Each node supports ER and VR protocols" },
  { 1, "Includes at least one node that does not support ER and VR"
      " protocols"  },
  { 0x0,  NULL }
};

/* VR_PAC_CNT_IND */
static const value_string sna_th_vr_pac_cnt_ind_vals[] = {
  { 0, "Pacing count on the VR has not reached 0" },
  { 1, "Pacing count on the VR has reached 0" },
  { 0x0,  NULL }
};

/* NTWK_PRTY */
static const value_string sna_th_ntwk_prty_vals[] = {
  { 0, "PIU flows at a lower priority" },
  { 1, "PIU flows at network priority (highest transmission priority)" },
  { 0x0,  NULL }
};

/* TGSF */
static const value_string sna_th_tgsf_vals[] = {
  { 0, "Not segmented" },
  { 1, "Last segment" },
  { 2, "First segment" },
  { 3, "Middle segment" },
  { 0x0,  NULL }
};

/* PIUBF */
static const value_string sna_th_piubf_vals[] = {
  { 0, "Single PIU frame" },
  { 1, "Last PIU of a multiple PIU frame" },
  { 2, "First PIU of a multiple PIU frame" },
  { 3, "Middle PIU of a multiple PIU frame" },
  { 0x0,  NULL }
};

/* NLPOI */
static const value_string sna_th_nlpoi_vals[] = {
  { 0, "NLP starts within this FID4 TH" },
  { 1, "NLP byte 0 starts after RH byte 0 following NLP C/P pad" },
  { 0x0,  NULL }
};

/* TPF */
static const value_string sna_th_tpf_vals[] = {
  { 0, "Low Priority" },
  { 1, "Medium Priority" },
  { 2, "High Priority" },
  { 3, "Network Priority" },
  { 0x0,  NULL }
};

/* VR_CWI */
static const value_string sna_th_vr_cwi_vals[] = {
  { 0, "Increment window size" },
  { 1, "Decrement window size" },
  { 0x0,  NULL }
};

/* TG_NONFIFO_IND */
static const true_false_string sna_th_tg_nonfifo_ind_truth =
  { "TG FIFO is not required", "TG FIFO is required" };

/* VR_SQTI */
static const value_string sna_th_vr_sqti_vals[] = {
  { 0, "Non-sequenced, Non-supervisory" },
  { 1, "Non-sequenced, Supervisory" },
  { 2, "Singly-sequenced" },
  { 0x0,  NULL }
};

/* VRPRQ */
static const true_false_string sna_th_vrprq_truth = {
  "VR pacing request is sent asking for a VR pacing response",
  "No VR pacing response is requested",
};

/* VRPRS */
static const true_false_string sna_th_vrprs_truth = {
  "VR pacing response is sent in response to a VRPRQ bit set",
  "No pacing response sent",
};

/* VR_CWRI */
static const value_string sna_th_vr_cwri_vals[] = {
  { 0, "Increment window size by 1" },
  { 1, "Decrement window size by 1" },
  { 0x0,  NULL }
};

/* VR_RWI */
static const true_false_string sna_th_vr_rwi_truth = {
  "Reset window size to the minimum specified in NC_ACTVR",
  "Do not reset window size",
};

/* Switching Mode */
static const value_string sna_nlp_sm_vals[] = {
  { 5, "Function routing" },
  { 6, "Automatic network routing" },
  { 0x0,  NULL }
};

static const true_false_string sna_nlp_tspi_truth =
  { "Time sensitive", "Not time sensitive" };

static const true_false_string sna_nlp_slowdn1_truth =
  { "Minor congestion", "No minor congestion" };

static const true_false_string sna_nlp_slowdn2_truth =
  { "Major congestion", "No major congestion" };

/* Function Type */
static const value_string sna_nlp_ft_vals[] = {
  { 0x10, "LDLC" },
  { 0x0,  NULL }
};

static const value_string sna_nlp_frh_vals[] = {
  { 0x03, "XID complete request" },
  { 0x04, "XID complete response" },
  { 0x0,  NULL }
};

static const true_false_string sna_nlp_setupi_truth =
  { "Connection setup segment present", "Connection setup segment not"
      " present" };

static const true_false_string sna_nlp_somi_truth =
  { "Start of message", "Not start of message" };

static const true_false_string sna_nlp_eomi_truth =
  { "End of message", "Not end of message" };

static const true_false_string sna_nlp_sri_truth =
  { "Status requested", "No status requested" };

static const true_false_string sna_nlp_rasapi_truth =
  { "Reply as soon as possible", "No need to reply as soon as possible" };

static const true_false_string sna_nlp_retryi_truth =
  { "Undefined", "Sender will retransmit" };

static const true_false_string sna_nlp_lmi_truth =
  { "Last message", "Not last message" };

static const true_false_string sna_nlp_cqfi_truth =
  { "CQFI included", "CQFI not included" };

static const true_false_string sna_nlp_osi_truth =
  { "Optional segments present", "No optional segments present" };

static const value_string sna_xid_3_state_vals[] = {
  { 0x00, "Exchange state indicators not supported" },
  { 0x01, "Negotiation-proceeding exchange" },
  { 0x02, "Prenegotiation exchange" },
  { 0x03, "Nonactivation exchange" },
  { 0x0, NULL }
};

static const value_string sna_xid_3_branch_vals[] = {
  { 0x00, "Sender does not support branch extender" },
  { 0x01, "TG is branch uplink" },
  { 0x02, "TG is branch downlink" },
  { 0x03, "TG is neither uplink nor downlink" },
  { 0x0, NULL }
};

static const value_string sna_xid_type_vals[] = {
  { 0x01, "T1 node" },
  { 0x02, "T2.0 or T2.1 node" },
  { 0x03, "Reserved" },
  { 0x04, "T4 or T5 node" },
  { 0x0, NULL }
};

static const value_string sna_nlp_opti_vals[] = {
  { 0x0d, "Connection Setup Segment" },
  { 0x0e, "Status Segment" },
  { 0x0f, "Client Out Of Band Bits Segment" },
  { 0x10, "Connection Identifier Exchange Segment" },
  { 0x12, "Connection Fault Segment" },
  { 0x14, "Switching Information Segment" },
  { 0x22, "Adaptive Rate-Based Segment" },
  { 0x0, NULL }
};

static const value_string sna_nlp_opti_0d_version_vals[] = {
  { 0x0101, "Version 1.1" },
  { 0x0, NULL }
};

static const value_string sna_nlp_opti_0f_bits_vals[] = {
  { 0x0001, "Request Deactivation" },
  { 0x8000, "Reply - OK" },
  { 0x8004, "Reply - Reject" },
  { 0x0, NULL }
};

static const value_string sna_nlp_opti_22_type_vals[] = {
  { 0x00, "Setup" },
  { 0x01, "Rate Reply" },
  { 0x02, "Rate Request" },
  { 0x03, "Rate Request/Rate Reply" },
  { 0x0, NULL }
};

static const value_string sna_nlp_opti_22_raa_vals[] = {
  { 0x00, "Normal" },
  { 0x01, "Restraint" },
  { 0x02, "Slowdown1" },
  { 0x03, "Slowdown2" },
  { 0x04, "Critical" },
  { 0x0, NULL }
};

static const value_string sna_nlp_opti_22_arb_vals[] = {
  { 0x00, "Base Mode ARB" },
  { 0x01, "Responsive Mode ARB" },
  { 0x0, NULL }
};

/* GDS Variable Type */
static const value_string sna_gds_var_vals[] = {
  { 0x1210, "Change Number Of Sessions" },
  { 0x1211, "Exchange Log Name" },
  { 0x1212, "Control Point Management Services Unit" },
  { 0x1213, "Compare States" },
  { 0x1214, "LU Names Position" },
  { 0x1215, "LU Name" },
  { 0x1217, "Do Know" },
  { 0x1218, "Partner Restart" },
  { 0x1219, "Don't Know" },
  { 0x1220, "Sign-Off" },
  { 0x1221, "Sign-On" },
  { 0x1222, "SNMP-over-SNA" },
  { 0x1223, "Node Address Service" },
  { 0x12C1, "CP Capabilities" },
  { 0x12C2, "Topology Database Update" },
  { 0x12C3, "Register Resource" },
  { 0x12C4, "Locate" },
  { 0x12C5, "Cross-Domain Initiate" },
  { 0x12C9, "Delete Resource" },
  { 0x12CA, "Find Resource" },
  { 0x12CB, "Found Resource" },
  { 0x12CC, "Notify" },
  { 0x12CD, "Initiate-Other Cross-Domain" },
  { 0x12CE, "Route Setup" },
  { 0x12E1, "Error Log" },
  { 0x12F1, "Null Data" },
  { 0x12F2, "User Control Date" },
  { 0x12F3, "Map Name" },
  { 0x12F4, "Error Data" },
  { 0x12F6, "Authentication Token Data" },
  { 0x12F8, "Service Flow Authentication Token Data" },
  { 0x12FF, "Application Data" },
  { 0x1310, "MDS Message Unit" },
  { 0x1311, "MDS Routing Information" },
  { 0x1500, "FID2 Encapsulation" },
  { 0x0,    NULL }
};

/* Control Vector Type */
static const value_string sna_control_vals[] = {
  { 0x00,   "SSCP-LU Session Capabilities Control Vector" },
  { 0x01,   "Date-Time Control Vector" },
  { 0x02,   "Subarea Routing Control Vector" },
  { 0x03,   "SDLC Secondary Station Control Vector" },
  { 0x04,   "LU Control Vector" },
  { 0x05,   "Channel Control Vector" },
  { 0x06,   "Cross-Domain Resource Manager (CDRM) Control Vector" },
  { 0x07,   "PU FMD-RU-Usage Control Vector" },
  { 0x08,   "Intensive Mode Control Vector" },
  { 0x09,   "Activation Request / Response Sequence Identifier Control"
      " Vector" },
  { 0x0a,   "User Request Correlator Control Vector" },
  { 0x0b,   "SSCP-PU Session Capabilities Control Vector" },
  { 0x0c,   "LU-LU Session Capabilities Control Vector" },
  { 0x0d,   "Mode / Class-of-Service / Virtual-Route-Identifier List"
      " Control Vector" },
  { 0x0e,   "Network Name Control Vector" },
  { 0x0f,   "Link Capabilities and Status Control Vector" },
  { 0x10,   "Product Set ID Control Vector" },
  { 0x11,   "Load Module Correlation Control Vector" },
  { 0x12,   "Network Identifier Control Vector" },
  { 0x13,   "Gateway Support Capabilities Control Vector" },
  { 0x14,   "Session Initiation Control Vector" },
  { 0x15,   "Network-Qualified Address Pair Control Vector" },
  { 0x16,   "Names Substitution Control Vector" },
  { 0x17,   "SSCP Identifier Control Vector" },
  { 0x18,   "SSCP Name Control Vector" },
  { 0x19,   "Resource Identifier Control Vector" },
  { 0x1a,   "NAU Address Control Vector" },
  { 0x1b,   "VRID List Control Vector" },
  { 0x1c,   "Network-Qualified Name Pair Control Vector" },
  { 0x1e,   "VR-ER Mapping Data Control Vector" },
  { 0x1f,   "ER Configuration Control Vector" },
  { 0x23,   "Local-Form Session Identifier Control Vector" },
  { 0x24,   "IPL Load Module Request Control Vector" },
  { 0x25,   "Security ID Control Control Vector" },
  { 0x26,   "Network Connection Endpoint Identifier Control Vector" },
  { 0x27,   "XRF Session Activation Control Vector" },
  { 0x28,   "Related Session Identifier Control Vector" },
  { 0x29,   "Session State Data Control Vector" },
  { 0x2a,   "Session Information Control Vector" },
  { 0x2b,   "Route Selection Control Vector" },
  { 0x2c,   "COS/TPF Control Vector" },
  { 0x2d,   "Mode Control Vector" },
  { 0x2f,   "LU Definition Control Vector" },
  { 0x30,   "Assign LU Characteristics Control Vector" },
  { 0x31,   "BIND Image Control Vector" },
  { 0x32,   "Short-Hold Mode Control Vector" },
  { 0x33,   "ENCP Search Control Control Vector" },
  { 0x34,   "LU Definition Override Control Vector" },
  { 0x35,   "Extended Sense Data Control Vector" },
  { 0x36,   "Directory Error Control Vector" },
  { 0x37,   "Directory Entry Correlator Control Vector" },
  { 0x38,   "Short-Hold Mode Emulation Control Vector" },
  { 0x39,   "Network Connection Endpoint (NCE) Instance Identifier"
      " Control Vector" },
  { 0x3a,   "Route Status Data Control Vector" },
  { 0x3b,   "VR Congestion Data Control Vector" },
  { 0x3c,   "Associated Resource Entry Control Vector" },
  { 0x3d,   "Directory Entry Control Vector" },
  { 0x3e,   "Directory Entry Characteristic Control Vector" },
  { 0x3f,   "SSCP (SLU) Capabilities Control Vector" },
  { 0x40,   "Real Associated Resource Control Vector" },
  { 0x41,   "Station Parameters Control Vector" },
  { 0x42,   "Dynamic Path Update Data Control Vector" },
  { 0x43,   "Extended SDLC Station Control Vector" },
  { 0x44,   "Node Descriptor Control Vector" },
  { 0x45,   "Node Characteristics Control Vector" },
  { 0x46,   "TG Descriptor Control Vector" },
  { 0x47,   "TG Characteristics Control Vector" },
  { 0x48,   "Topology Resource Descriptor Control Vector" },
  { 0x49,   "Multinode Persistent Sessions (MNPS) LU Names Control"
      " Vector" },
  { 0x4a,   "Real Owning Control Point Control Vector" },
  { 0x4b,   "RTP Transport Connection Identifier Control Vector" },
  { 0x51,   "DLUR/S Capabilities Control Vector" },
  { 0x52,   "Primary Send Pacing Window Size Control Vector" },
  { 0x56,   "Call Security Verification Control Vector" },
  { 0x57,   "DLC Connection Data Control Vector" },
  { 0x59,   "Installation-Defined CDINIT Data Control Vector" },
  { 0x5a,   "Session Services Extension Support Control Vector" },
  { 0x5b,   "Interchange Node Support Control Vector" },
  { 0x5c,   "APPN Message Transport Control Vector" },
  { 0x5d,   "Subarea Message Transport Control Vector" },
  { 0x5e,   "Related Request Control Vector" },
  { 0x5f,   "Extended Fully Qualified PCID Control Vector" },
  { 0x60,   "Fully Qualified PCID Control Vector" },
  { 0x61,   "HPR Capabilities Control Vector" },
  { 0x62,   "Session Address Control Vector" },
  { 0x63,   "Cryptographic Key Distribution Control Vector" },
  { 0x64,   "TCP/IP Information Control Vector" },
  { 0x65,   "Device Characteristics Control Vector" },
  { 0x66,   "Length-Checked Compression Control Vector" },
  { 0x67,   "Automatic Network Routing (ANR) Path Control Vector" },
  { 0x68,   "XRF/Session Cryptography Control Vector" },
  { 0x69,   "Switched Parameters Control Vector" },
  { 0x6a,   "ER Congestion Data Control Vector" },
  { 0x71,   "Triple DES Cryptography Key Continuation Control Vector" },
  { 0xfe,   "Control Vector Keys Not Recognized" },
  { 0x0,    NULL }
};

static const value_string sna_control_hpr_vals[] = {
  { 0x00,   "Node Identifier Control Vector" },
  { 0x03,   "Network ID Control Vector" },
  { 0x05,   "Network Address Control Vector" },
  { 0x0,    NULL }
};

static const value_string sna_control_0e_type_vals[] = {
  { 0xF1,   "PU Name" },
  { 0xF3,   "LU Name" },
  { 0xF4,   "CP Name" },
  { 0xF5,   "SSCP Name" },
  { 0xF6,   "NNCP Name" },
  { 0xF7,   "Link Station Name" },
  { 0xF8,   "CP Name of CP(PLU)" },
  { 0xF9,   "CP Name of CP(SLU)" },
  { 0xFA,   "Generic Name" },
  { 0x0,    NULL }
};

/* Values to direct the top-most dissector what to dissect
 * after the TH. */
enum next_dissection_enum {
  stop_here,
  rh_only,
  everything
};

enum parse {
  LT,
  KL
};

/*
 * Structure used to represent an FID Type 4 address; gives the layout of the
 * data pointed to by an AT_SNA "address" structure if the size is
 * SNA_FID_TYPE_4_ADDR_LEN.
 */
#define SNA_FID_TYPE_4_ADDR_LEN 6
struct sna_fid_type_4_addr {
  uint32_t  saf;
  uint16_t  ef;
};

typedef enum next_dissection_enum next_dissection_t;

static void dissect_xid (tvbuff_t*, packet_info*, proto_tree*, proto_tree*);
static void dissect_fid (tvbuff_t*, packet_info*, proto_tree*, proto_tree*);
static void dissect_nlp (tvbuff_t*, packet_info*, proto_tree*, proto_tree*);
static void dissect_gds (tvbuff_t*, packet_info*, proto_tree*, proto_tree*);
static void dissect_rh (tvbuff_t*, int, proto_tree*);
static void dissect_sna_control(tvbuff_t* parent_tvb, int offset, int control_len, proto_tree* tree, int hpr, enum parse parse);

static int sna_fid_to_str_buf(const address *addr, char *buf, int buf_len _U_)
{
  const uint8_t *addrdata;
  struct sna_fid_type_4_addr sna_fid_type_4_addr;
  char *bufp = buf;

  switch (addr->len) {

  case 1:
    addrdata = (const uint8_t *)addr->data;
    word_to_hex(buf, addrdata[0]);
    buf[4] = '\0';
    break;

  case 2:
    addrdata = (const uint8_t *)addr->data;
    word_to_hex(buf, pntohu16(&addrdata[0]));
    buf[4] = '\0';
    break;

  case SNA_FID_TYPE_4_ADDR_LEN:
    /* FID Type 4 */
    memcpy(&sna_fid_type_4_addr, addr->data, SNA_FID_TYPE_4_ADDR_LEN);

    bufp = dword_to_hex(bufp, sna_fid_type_4_addr.saf);
    *bufp++ = '.';
    bufp = word_to_hex(bufp, sna_fid_type_4_addr.ef);
    *bufp++ = '\0'; /* NULL terminate */
    break;
  default:
    buf[0] = '\0';
    return 1;
  }

  return (int)strlen(buf)+1;
}


static int sna_address_str_len(const address* addr _U_)
{
  /* We could do this based on address length, but 14 bytes isn't THAT much space */
  return 14;
}


/* --------------------------------------------------------------------
 * Chapter 2 High-Performance Routing (HPR) Headers
 * --------------------------------------------------------------------
 */

static void
dissect_optional_0d(tvbuff_t *tvb, proto_tree *tree)
{
  int   offset, len, pad;
  static int * const fields[] = {
    &hf_sna_nlp_opti_0d_target,
    &hf_sna_nlp_opti_0d_arb,
    &hf_sna_nlp_opti_0d_reliable,
    &hf_sna_nlp_opti_0d_dedicated,
    NULL
  };

  if (!tree)
    return;

  proto_tree_add_item(tree, hf_sna_nlp_opti_0d_version, tvb, 2, 2, ENC_BIG_ENDIAN);

  proto_tree_add_bitmask(tree, tvb, 4, hf_sna_nlp_opti_0d_4,
             ett_sna_nlp_opti_0d_4, fields, ENC_NA);

  proto_tree_add_item(tree, hf_sna_reserved, tvb, 5, 3, ENC_NA);

  offset = 8;

  while (tvb_offset_exists(tvb, offset)) {
    len = tvb_get_uint8(tvb, offset+0);
    if (len) {
      dissect_sna_control(tvb, offset, len, tree, 1, LT);
      pad = (len+3) & 0xfffc;
      if (pad > len)
        proto_tree_add_item(tree, hf_sna_padding, tvb, offset+len, pad-len, ENC_NA);
      offset += pad;
    } else {
      /* Avoid endless loop */
      return;
    }
  }
}

static void
dissect_optional_0e(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
  int   bits, offset;
  static int * const fields[] = {
    &hf_sna_nlp_opti_0e_gap,
    &hf_sna_nlp_opti_0e_idle,
    NULL
  };

  bits = tvb_get_uint8(tvb, 2);
  offset = 20;

  proto_tree_add_bitmask(tree, tvb, 2, hf_sna_nlp_opti_0e_stat,
          ett_sna_nlp_opti_0e_stat, fields, ENC_NA);

  proto_tree_add_item(tree, hf_sna_nlp_opti_0e_nabsp,
    tvb, 3, 1, ENC_BIG_ENDIAN);
  proto_tree_add_item(tree, hf_sna_nlp_opti_0e_sync,
    tvb, 4, 2, ENC_BIG_ENDIAN);
  proto_tree_add_item(tree, hf_sna_nlp_opti_0e_echo,
    tvb, 6, 2, ENC_BIG_ENDIAN);
  proto_tree_add_item(tree, hf_sna_nlp_opti_0e_rseq,
    tvb, 8, 4, ENC_BIG_ENDIAN);
  proto_tree_add_item(tree, hf_sna_reserved, tvb, 12, 8, ENC_NA);

  if (tvb_offset_exists(tvb, offset))
    call_data_dissector(tvb_new_subset_remaining(tvb, 4), pinfo, tree);

  if (bits & 0x40) {
    col_set_str(pinfo->cinfo, COL_INFO, "HPR Idle Message");
  } else {
    col_set_str(pinfo->cinfo, COL_INFO, "HPR Status Message");
  }
}

static void
dissect_optional_0f(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
  proto_tree_add_item(tree, hf_sna_nlp_opti_0f_bits, tvb, 2, 2, ENC_BIG_ENDIAN);
  if (tvb_offset_exists(tvb, 4))
    call_data_dissector(tvb_new_subset_remaining(tvb, 4), pinfo, tree);
}

static void
dissect_optional_10(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
  proto_tree_add_item(tree, hf_sna_reserved, tvb, 2, 2, ENC_NA);
  proto_tree_add_item(tree, hf_sna_nlp_opti_10_tcid, tvb, 4, 8, ENC_NA);
  if (tvb_offset_exists(tvb, 12))
    call_data_dissector(tvb_new_subset_remaining(tvb, 12), pinfo, tree);
}

static void
dissect_optional_12(tvbuff_t *tvb, proto_tree *tree)
{
  proto_tree_add_item(tree, hf_sna_reserved, tvb, 2, 2, ENC_NA);
  proto_tree_add_item(tree, hf_sna_nlp_opti_12_sense, tvb, 4, -1, ENC_NA);
}

static void
dissect_optional_14(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
  proto_tree  *sub_tree;
  int   len, pad, type, offset, num, sublen;
  static int * const opti_14_si_fields[] = {
    &hf_sna_nlp_opti_14_si_refifo,
    &hf_sna_nlp_opti_14_si_mobility,
    &hf_sna_nlp_opti_14_si_dirsearch,
    &hf_sna_nlp_opti_14_si_limitres,
    &hf_sna_nlp_opti_14_si_ncescope,
    &hf_sna_nlp_opti_14_si_mnpsrscv,
    NULL
  };
  static int * const opti_14_rr_fields[] = {
    &hf_sna_nlp_opti_14_rr_bfe,
    NULL
  };

  proto_tree_add_item(tree, hf_sna_reserved, tvb, 2, 2, ENC_NA);

  offset = 4;

  len = tvb_get_uint8(tvb, offset);
  type = tvb_get_uint8(tvb, offset+1);

  if ((type != 0x83) || (len <= 16)) {
    /* Invalid */
    call_data_dissector(tvb_new_subset_remaining(tvb, offset), pinfo, tree);
    return;
  }
  sub_tree = proto_tree_add_subtree(tree, tvb, offset, len,
      ett_sna_nlp_opti_14_si, NULL, "Switching Information Control Vector");

  proto_tree_add_uint(sub_tree, hf_sna_nlp_opti_14_si_len,
      tvb, offset, 1, len);
  proto_tree_add_uint(sub_tree, hf_sna_nlp_opti_14_si_key,
      tvb, offset+1, 1, type);

  proto_tree_add_bitmask(tree, tvb, offset+2, hf_sna_nlp_opti_14_si_2,
             ett_sna_nlp_opti_14_si_2, opti_14_si_fields, ENC_NA);

  proto_tree_add_item(sub_tree, hf_sna_reserved, tvb, offset+3, 1, ENC_NA);
  proto_tree_add_item(sub_tree, hf_sna_nlp_opti_14_si_maxpsize,
      tvb, offset+4, 4, ENC_BIG_ENDIAN);
  proto_tree_add_item(sub_tree, hf_sna_nlp_opti_14_si_switch,
      tvb, offset+8, 4, ENC_BIG_ENDIAN);
  proto_tree_add_item(sub_tree, hf_sna_nlp_opti_14_si_alive,
      tvb, offset+12, 4, ENC_BIG_ENDIAN);

  dissect_sna_control(tvb, offset+16, len-16, sub_tree, 1, LT);

  pad = (len+3) & 0xfffc;
  if (pad > len)
    proto_tree_add_item(sub_tree, hf_sna_padding, tvb, offset+len, pad-len, ENC_NA);
  offset += pad;

  len = tvb_get_uint8(tvb, offset);
  type = tvb_get_uint8(tvb, offset+1);

  if ((type != 0x85) || ( len < 4))  {
    /* Invalid */
    call_data_dissector(tvb_new_subset_remaining(tvb, offset), pinfo, tree);
    return;
  }
  sub_tree = proto_tree_add_subtree(tree, tvb, offset, len,
      ett_sna_nlp_opti_14_rr, NULL, "Return Route TG Descriptor Control Vector");

  proto_tree_add_uint(sub_tree, hf_sna_nlp_opti_14_rr_len,
      tvb, offset, 1, len);
  proto_tree_add_uint(sub_tree, hf_sna_nlp_opti_14_rr_key,
      tvb, offset+1, 1, type);

  proto_tree_add_bitmask(tree, tvb, offset+2, hf_sna_nlp_opti_14_rr_2,
             ett_sna_nlp_opti_14_rr_2, opti_14_rr_fields, ENC_NA);

  num = tvb_get_uint8(tvb, offset+3);

  proto_tree_add_uint(sub_tree, hf_sna_nlp_opti_14_rr_num,
      tvb, offset+3, 1, num);

  offset += 4;

  while (num) {
    sublen = tvb_get_uint8(tvb, offset);
    if (sublen) {
      dissect_sna_control(tvb, offset, sublen, sub_tree, 1, LT);
    } else {
      /* Invalid */
      call_data_dissector(tvb_new_subset_remaining(tvb, offset), pinfo, tree);
      return;
    }
    /* No padding here */
    offset += sublen;
    num--;
  }
}

static void
dissect_optional_22(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
  int   bits, type;
  static int * const opti_22_2_fields[] = {
    &hf_sna_nlp_opti_22_type,
    &hf_sna_nlp_opti_22_raa,
    &hf_sna_nlp_opti_22_parity,
    &hf_sna_nlp_opti_22_arb,
    NULL
  };
  static int * const opti_22_3_fields[] = {
    &hf_sna_nlp_opti_22_ratereq,
    &hf_sna_nlp_opti_22_raterep,
    NULL
  };

  bits = tvb_get_uint8(tvb, 2);
  type = (bits & 0xc0) >> 6;

  proto_tree_add_bitmask(tree, tvb, 2, hf_sna_nlp_opti_22_2,
             ett_sna_nlp_opti_22_2, opti_22_2_fields, ENC_NA);

  proto_tree_add_bitmask(tree, tvb, 3, hf_sna_nlp_opti_22_3,
             ett_sna_nlp_opti_22_3, opti_22_3_fields, ENC_NA);

  proto_tree_add_item(tree, hf_sna_nlp_opti_22_field1,
      tvb, 4, 4, ENC_BIG_ENDIAN);
  proto_tree_add_item(tree, hf_sna_nlp_opti_22_field2,
      tvb, 8, 4, ENC_BIG_ENDIAN);

  if (type == 0) {
    proto_tree_add_item(tree, hf_sna_nlp_opti_22_field3,
        tvb, 12, 4, ENC_BIG_ENDIAN);
    proto_tree_add_item(tree, hf_sna_nlp_opti_22_field4,
        tvb, 16, 4, ENC_BIG_ENDIAN);

    if (tvb_offset_exists(tvb, 20))
      call_data_dissector(tvb_new_subset_remaining(tvb, 20), pinfo, tree);
  } else {
    if (tvb_offset_exists(tvb, 12))
      call_data_dissector(tvb_new_subset_remaining(tvb, 12), pinfo, tree);
  }
}

static void
dissect_optional(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
  proto_tree  *sub_tree;
  int   offset, type, len;
  int   ett;

  sub_tree = NULL;

  offset = 0;

  while (tvb_offset_exists(tvb, offset)) {
    len = tvb_get_uint8(tvb, offset);
    type = tvb_get_uint8(tvb, offset+1);

    /* Prevent loop for invalid crap in packet */
    if (len == 0) {
      call_data_dissector(tvb_new_subset_remaining(tvb, offset), pinfo, tree);
      return;
    }

    ett = ett_sna_nlp_opti_un;
    if(type == 0x0d) ett = ett_sna_nlp_opti_0d;
    if(type == 0x0e) ett = ett_sna_nlp_opti_0e;
    if(type == 0x0f) ett = ett_sna_nlp_opti_0f;
    if(type == 0x10) ett = ett_sna_nlp_opti_10;
    if(type == 0x12) ett = ett_sna_nlp_opti_12;
    if(type == 0x14) ett = ett_sna_nlp_opti_14;
    if(type == 0x22) ett = ett_sna_nlp_opti_22;
    if (tree) {
      sub_tree = proto_tree_add_subtree(tree, tvb,
          offset, len << 2, ett, NULL,
          val_to_str_const(type, sna_nlp_opti_vals, "Unknown Segment Type"));
      proto_tree_add_uint(sub_tree, hf_sna_nlp_opti_len,
          tvb, offset, 1, len);
      proto_tree_add_uint(sub_tree, hf_sna_nlp_opti_type,
          tvb, offset+1, 1, type);
    }
    switch(type) {
      case 0x0d:
        dissect_optional_0d(tvb_new_subset_length(tvb, offset,
            len << 2), sub_tree);
        break;
      case 0x0e:
        dissect_optional_0e(tvb_new_subset_length(tvb, offset,
            len << 2), pinfo, sub_tree);
        break;
      case 0x0f:
        dissect_optional_0f(tvb_new_subset_length(tvb, offset,
            len << 2), pinfo, sub_tree);
        break;
      case 0x10:
        dissect_optional_10(tvb_new_subset_length(tvb, offset,
            len << 2), pinfo, sub_tree);
        break;
      case 0x12:
        dissect_optional_12(tvb_new_subset_length(tvb, offset,
            len << 2), sub_tree);
        break;
      case 0x14:
        dissect_optional_14(tvb_new_subset_length(tvb, offset,
            len << 2), pinfo, sub_tree);
        break;
      case 0x22:
        dissect_optional_22(tvb_new_subset_length(tvb, offset,
            len << 2), pinfo, sub_tree);
        break;
      default:
        call_data_dissector(tvb_new_subset_length(tvb, offset,
            len << 2), pinfo, sub_tree);
    }
    offset += (len << 2);
  }
}

static void
dissect_nlp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
      proto_tree *parent_tree)
{
  proto_tree  *nlp_tree;
  proto_item  *nlp_item;
  uint8_t   nhdr_0, nhdr_1, nhdr_x, thdr_8, thdr_9, fid;
  uint32_t    thdr_len, thdr_dlf;
  uint16_t    subindx;
  static int * const nlp_nhdr_0_fields[] = {
    &hf_sna_nlp_sm,
    &hf_sna_nlp_tpf,
    NULL
  };
  static int * const nlp_nhdr_1_fields[] = {
    &hf_sna_nlp_ft,
    &hf_sna_nlp_tspi,
    &hf_sna_nlp_slowdn1,
    &hf_sna_nlp_slowdn2,
    NULL
  };
  static int * const nlp_nhdr_8_fields[] = {
    &hf_sna_nlp_setupi,
    &hf_sna_nlp_somi,
    &hf_sna_nlp_eomi,
    &hf_sna_nlp_sri,
    &hf_sna_nlp_rasapi,
    &hf_sna_nlp_retryi,
    NULL
  };
  static int * const nlp_nhdr_9_fields[] = {
    &hf_sna_nlp_lmi,
    &hf_sna_nlp_cqfi,
    &hf_sna_nlp_osi,
    NULL
  };

  int indx = 0, counter = 0;

  nlp_tree = NULL;
  nlp_item = NULL;

  nhdr_0 = tvb_get_uint8(tvb, indx);
  nhdr_1 = tvb_get_uint8(tvb, indx+1);

  col_set_str(pinfo->cinfo, COL_INFO, "HPR NLP Packet");

  if (tree) {
    /* Don't bother setting length. We'll set it later after we
     * find the lengths of NHDR */
    nlp_item = proto_tree_add_item(tree, hf_sna_nlp_nhdr, tvb,
        indx, -1, ENC_NA);
    nlp_tree = proto_item_add_subtree(nlp_item, ett_sna_nlp_nhdr);

    proto_tree_add_bitmask(nlp_tree, tvb, indx, hf_sna_nlp_nhdr_0,
             ett_sna_nlp_nhdr_0, nlp_nhdr_0_fields, ENC_NA);

    proto_tree_add_bitmask(nlp_tree, tvb, indx+1, hf_sna_nlp_nhdr_1,
             ett_sna_nlp_nhdr_1, nlp_nhdr_1_fields, ENC_NA);
  }
  /* ANR or FR lists */

  indx += 2;
  counter = 0;

  if ((nhdr_0 & 0xe0) == 0xa0) {
    do {
      nhdr_x = tvb_get_uint8(tvb, indx + counter);
      counter ++;
    } while (nhdr_x != 0xff);
    proto_tree_add_item(nlp_tree,
          hf_sna_nlp_fra, tvb, indx, counter, ENC_NA);
    indx += counter;
    proto_tree_add_item(nlp_tree, hf_sna_reserved, tvb, indx, 1, ENC_NA);
    indx++;

    if (tree)
      proto_item_set_len(nlp_item, indx);

    if ((nhdr_1 & 0xf0) == 0x10) {
      proto_tree_add_item(tree, hf_sna_nlp_frh,
            tvb, indx, 1, ENC_BIG_ENDIAN);
      indx ++;

      if (tvb_offset_exists(tvb, indx))
        call_data_dissector(tvb_new_subset_remaining(tvb, indx),
          pinfo, parent_tree);
      return;
    }
  }
  if ((nhdr_0 & 0xe0) == 0xc0) {
    do {
      nhdr_x = tvb_get_uint8(tvb, indx + counter);
      counter ++;
    } while (nhdr_x != 0xff);
    proto_tree_add_item(nlp_tree, hf_sna_nlp_anr,
          tvb, indx, counter, ENC_NA);
    indx += counter;

    proto_tree_add_item(nlp_tree, hf_sna_reserved, tvb, indx, 1, ENC_NA);
    indx++;

    if (tree)
      proto_item_set_len(nlp_item, indx);
  }

  thdr_8 = tvb_get_uint8(tvb, indx+8);
  thdr_9 = tvb_get_uint8(tvb, indx+9);
  thdr_len = tvb_get_ntohs(tvb, indx+10);
  thdr_dlf = tvb_get_ntohl(tvb, indx+12);

  if (tree) {
    nlp_item = proto_tree_add_item(tree, hf_sna_nlp_thdr, tvb,
        indx, thdr_len << 2, ENC_NA);
    nlp_tree = proto_item_add_subtree(nlp_item, ett_sna_nlp_thdr);

    proto_tree_add_item(nlp_tree, hf_sna_nlp_tcid, tvb,
        indx, 8, ENC_NA);

    proto_tree_add_bitmask(nlp_tree, tvb, indx+8, hf_sna_nlp_thdr_8,
             ett_sna_nlp_thdr_8, nlp_nhdr_8_fields, ENC_NA);

    proto_tree_add_bitmask(nlp_tree, tvb, indx+9, hf_sna_nlp_thdr_9,
             ett_sna_nlp_thdr_9, nlp_nhdr_9_fields, ENC_NA);

    proto_tree_add_uint(nlp_tree, hf_sna_nlp_offset, tvb, indx+10,
        2, thdr_len);
    proto_tree_add_uint(nlp_tree, hf_sna_nlp_dlf, tvb, indx+12,
        4, thdr_dlf);
    proto_tree_add_item(nlp_tree, hf_sna_nlp_bsn, tvb, indx+16,
        4, ENC_BIG_ENDIAN);
  }
  subindx = 20;

  if (((thdr_9 & 0x18) == 0x08) && ((thdr_len << 2) > subindx)) {
    counter = tvb_get_uint8(tvb, indx + subindx);
    if (tvb_get_uint8(tvb, indx+subindx+1) == 5)
      dissect_sna_control(tvb, indx + subindx, counter+2, nlp_tree, 1, LT);
    else
      call_data_dissector(tvb_new_subset_length(tvb, indx + subindx, counter+2),
          pinfo, nlp_tree);

    subindx += (counter+2);
  }
  if ((thdr_9 & 0x04) && ((thdr_len << 2) > subindx))
    dissect_optional(
        tvb_new_subset_length(tvb, indx + subindx,
        (thdr_len << 2) - subindx),
        pinfo, nlp_tree);

  indx += (thdr_len << 2);
  if (((thdr_8 & 0x20) == 0) && thdr_dlf) {
    col_set_str(pinfo->cinfo, COL_INFO, "HPR Fragment");
    if (tvb_offset_exists(tvb, indx)) {
      call_data_dissector(tvb_new_subset_remaining(tvb, indx), pinfo,
          parent_tree);
    }
    return;
  }
  if (tvb_offset_exists(tvb, indx)) {
    /* Transmission Header Format Identifier */
    fid = hi_nibble(tvb_get_uint8(tvb, indx));
    if (fid == 5) /* Only FID5 allowed for HPR */
      dissect_fid(tvb_new_subset_remaining(tvb, indx), pinfo,
          tree, parent_tree);
    else {
      if (tvb_get_ntohs(tvb, indx+2) == 0x12ce) {
        /* Route Setup */
        col_set_str(pinfo->cinfo, COL_INFO, "HPR Route Setup");
        dissect_gds(tvb_new_subset_remaining(tvb, indx),
            pinfo, tree, parent_tree);
      } else
        call_data_dissector(tvb_new_subset_remaining(tvb, indx),
            pinfo, parent_tree);
    }
  }
}

/* --------------------------------------------------------------------
 * Chapter 3 Exchange Identification (XID) Information Fields
 * --------------------------------------------------------------------
 */

static void
dissect_xid1(tvbuff_t *tvb, proto_tree *tree)
{
  proto_tree_add_item(tree, hf_sna_reserved, tvb, 0, 2, ENC_NA);

}

static void
dissect_xid2(tvbuff_t *tvb, proto_tree *tree)
{
  unsigned    dlen, offset;

  if (!tree)
    return;

  dlen = tvb_get_uint8(tvb, 0);

  offset = dlen;

  while (tvb_offset_exists(tvb, offset)) {
    dlen = tvb_get_uint8(tvb, offset+1);
    dissect_sna_control(tvb, offset, dlen+2, tree, 0, KL);
    offset += (dlen + 2);
  }
}

static void
dissect_xid3(tvbuff_t *tvb, proto_tree *tree)
{
  unsigned    dlen, offset;
  static int * const sna_xid_3_fields[] = {
    &hf_sna_xid_3_init_self,
    &hf_sna_xid_3_stand_bind,
    &hf_sna_xid_3_gener_bind,
    &hf_sna_xid_3_recve_bind,
    &hf_sna_xid_3_actpu,
    &hf_sna_xid_3_nwnode,
    &hf_sna_xid_3_cp,
    &hf_sna_xid_3_cpcp,
    &hf_sna_xid_3_state,
    &hf_sna_xid_3_nonact,
    &hf_sna_xid_3_cpchange,
    NULL
  };
  static int * const sna_xid_10_fields[] = {
    &hf_sna_xid_3_asend_bind,
    &hf_sna_xid_3_arecv_bind,
    &hf_sna_xid_3_quiesce,
    &hf_sna_xid_3_pucap,
    &hf_sna_xid_3_pbn,
    &hf_sna_xid_3_pacing,
    NULL
  };
  static int * const sna_xid_11_fields[] = {
    &hf_sna_xid_3_tgshare,
    &hf_sna_xid_3_dedsvc,
    NULL
  };
  static int * const sna_xid_12_fields[] = {
    &hf_sna_xid_3_negcsup,
    &hf_sna_xid_3_negcomp,
    NULL
  };
  static int * const sna_xid_15_fields[] = {
    &hf_sna_xid_3_partg,
    &hf_sna_xid_3_dlur,
    &hf_sna_xid_3_dlus,
    &hf_sna_xid_3_exbn,
    &hf_sna_xid_3_genodai,
    &hf_sna_xid_3_branch,
    &hf_sna_xid_3_brnn,
    NULL
  };

  if (!tree)
    return;

  proto_tree_add_item(tree, hf_sna_reserved, tvb, 0, 2, ENC_NA);

  proto_tree_add_bitmask(tree, tvb, 2, hf_sna_xid_3_8,
             ett_sna_xid_3_8, sna_xid_3_fields, ENC_BIG_ENDIAN);

  proto_tree_add_bitmask(tree, tvb, 4, hf_sna_xid_3_10,
             ett_sna_xid_3_10, sna_xid_10_fields, ENC_BIG_ENDIAN);

  proto_tree_add_bitmask(tree, tvb, 5, hf_sna_xid_3_11,
             ett_sna_xid_3_11, sna_xid_11_fields, ENC_BIG_ENDIAN);

  proto_tree_add_bitmask(tree, tvb, 6, hf_sna_xid_3_12,
             ett_sna_xid_3_12, sna_xid_12_fields, ENC_BIG_ENDIAN);

  proto_tree_add_item(tree, hf_sna_reserved, tvb, 7, 2, ENC_NA);

  proto_tree_add_bitmask(tree, tvb, 9, hf_sna_xid_3_15,
             ett_sna_xid_3_15, sna_xid_15_fields, ENC_BIG_ENDIAN);

  proto_tree_add_item(tree, hf_sna_xid_3_tg, tvb, 10, 1, ENC_BIG_ENDIAN);
  proto_tree_add_item(tree, hf_sna_xid_3_dlc, tvb, 11, 1, ENC_BIG_ENDIAN);

  dlen = tvb_get_uint8(tvb, 12);

  proto_tree_add_uint(tree, hf_sna_xid_3_dlen, tvb, 12, 1, dlen);

  /* FIXME: DLC Dependent Data Go Here */

  offset = 12 + dlen;

  while (tvb_offset_exists(tvb, offset)) {
    dlen = tvb_get_uint8(tvb, offset+1);
    dissect_sna_control(tvb, offset, dlen+2, tree, 0, KL);
    offset += (dlen+2);
  }
}

static void
dissect_xid(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
      proto_tree *parent_tree)
{
  proto_tree  *sub_tree;
  proto_item  *sub_ti = NULL;
  int   format, type, len;
  uint32_t    id;

  len = tvb_get_uint8(tvb, 1);
  type = tvb_get_uint8(tvb, 0);
  id = tvb_get_ntohl(tvb, 2);
  format = hi_nibble(type);

  /* Summary information */
  col_add_fstr(pinfo->cinfo, COL_INFO,
        "SNA XID Format:%d Type:%s", format,
        val_to_str_const(lo_nibble(type), sna_xid_type_vals,
        "Unknown Type"));

  if (tree) {
    sub_ti = proto_tree_add_item(tree, hf_sna_xid_0, tvb,
        0, 1, ENC_BIG_ENDIAN);
    sub_tree = proto_item_add_subtree(sub_ti, ett_sna_xid_0);

    proto_tree_add_uint(sub_tree, hf_sna_xid_format, tvb, 0, 1,
        type);
    proto_tree_add_uint(sub_tree, hf_sna_xid_type, tvb, 0, 1,
        type);

    proto_tree_add_uint(tree, hf_sna_xid_len, tvb, 1, 1, len);

    sub_ti = proto_tree_add_item(tree, hf_sna_xid_id, tvb,
        2, 4, ENC_BIG_ENDIAN);
    sub_tree = proto_item_add_subtree(sub_ti, ett_sna_xid_id);

    proto_tree_add_uint(sub_tree, hf_sna_xid_idblock, tvb, 2, 4,
        id);
    proto_tree_add_uint(sub_tree, hf_sna_xid_idnum, tvb, 2, 4,
        id);

    switch(format) {
      case 0:
        break;
      case 1:
        dissect_xid1(tvb_new_subset_length(tvb, 6, len-6),
            tree);
        break;
      case 2:
        dissect_xid2(tvb_new_subset_length(tvb, 6, len-6),
            tree);
        break;
      case 3:
        dissect_xid3(tvb_new_subset_length(tvb, 6, len-6),
            tree);
        break;
      default:
        /* external standards organizations */
        call_data_dissector(tvb_new_subset_length(tvb, 6, len-6),
            pinfo, tree);
    }
  }

  if (format == 0)
    len = 6;

  if (tvb_offset_exists(tvb, len))
    call_data_dissector(tvb_new_subset_remaining(tvb, len), pinfo, parent_tree);
}

/* --------------------------------------------------------------------
 * Chapter 4 Transmission Headers (THs)
 * --------------------------------------------------------------------
 */

#define RH_LEN  3

static unsigned int
mpf_value(uint8_t th_byte)
{
  return (th_byte & 0x0c) >> 2;
}

#define FIRST_FRAG_NUMBER 0
#define MIDDLE_FRAG_NUMBER  1
#define LAST_FRAG_NUMBER  2

/* FID2 is defragged by sequence. The weird thing is that we have neither
 * absolute sequence numbers, nor byte offets. Other FIDs have byte offsets
 * (the DCF field), but not FID2. The only thing we have to go with is "FIRST",
 * "MIDDLE", or "LAST". If the BIU is split into 3 frames, then everything is
 * fine, * "FIRST", "MIDDLE", and "LAST" map nicely onto frag-number 0, 1,
 * and 2. However, if the BIU is split into 2 frames, then we only have
 * "FIRST" and "LAST", and the mapping *should* be frag-number 0 and 1,
 * *NOT* 0 and 2.
 *
 * The SNA docs say "FID2 PIUs cannot be blocked because there is no DCF in the
 * TH format for deblocking" (note on Figure 4-2 in the IBM SNA documention,
 * see the FTP URL in the comment near the top of this file). I *think*
 * this means that the fragmented frames cannot arrive out of order.
 * Well, I *want* it to mean this, because w/o this limitation, if you
 * get a "FIRST" frame and a "LAST" frame, how long should you wait to
 * see if a "MIDDLE" frame every arrives????? Thus, if frames *have* to
 * arrive in order, then we're saved.
 *
 * The problem then boils down to figuring out if "LAST" means frag-number 1
 * (in the case of a BIU split into 2 frames) or frag-number 2
 * (in the case of a BIU split into 3 frames).
 *
 * Assuming fragmented FID2 BIU frames *do* arrive in order, the obvious
 * way to handle the mapping of "LAST" to either frag-number 1 or
 * frag-number 2 is to keep a hash which tracks the frames seen, etc.
 * This consumes resources. A trickier way, but a way which works, is to
 * always map the "LAST" BIU segment to frag-number 2. Here's the trickery:
 * if we add frag-number 2, which we know to be the "LAST" BIU segment,
 * and the reassembly code tells us that the BIU is still not reassmebled,
 * then, owing to the, ahem, /fact/, that fragmented BIU segments arrive
 * in order :), we know that 1) "FIRST" did come, and 2) there's no "MIDDLE",
 * because this BIU was fragmented into 2 frames, not 3. So, we'll be
 * tricky and add a zero-length "MIDDLE" BIU frame (i.e, frag-number 1)
 * to complete the reassembly.
 */
static tvbuff_t*
defragment_by_sequence(packet_info *pinfo, tvbuff_t *tvb, int offset, int mpf,
           int id)
{
  fragment_head *fd_head;
  int frag_number = -1;
  bool more_frags = true;
  tvbuff_t *rh_tvb = NULL;
  int frag_len;

  /* Determine frag_number and more_frags */
  switch(mpf) {
    case MPF_WHOLE_BIU:
      /* nothing */
      break;
    case MPF_FIRST_SEGMENT:
      frag_number = FIRST_FRAG_NUMBER;
      break;
    case MPF_MIDDLE_SEGMENT:
      frag_number = MIDDLE_FRAG_NUMBER;
      break;
    case MPF_LAST_SEGMENT:
      frag_number = LAST_FRAG_NUMBER;
      more_frags = false;
      break;
    default:
      DISSECTOR_ASSERT_NOT_REACHED();
  }

  /* If sna_defragment is on, and this is a fragment.. */
  if (frag_number > -1) {
    /* XXX - check length ??? */
    frag_len = tvb_reported_length_remaining(tvb, offset);
    if (tvb_bytes_exist(tvb, offset, frag_len)) {
      fd_head = fragment_add_seq(&sna_reassembly_table,
          tvb, offset, pinfo, id, NULL,
          frag_number, frag_len, more_frags, 0);

      /* We added the LAST segment and reassembly didn't
       * complete. Insert a zero-length MIDDLE segment to
       * turn a 2-frame BIU-fragmentation into a 3-frame
       * BIU-fragmentation (empty middle frag).
             * See above long comment about this trickery. */

      if (mpf == MPF_LAST_SEGMENT && !fd_head) {
        fd_head = fragment_add_seq(&sna_reassembly_table,
            tvb, offset, pinfo, id, NULL,
            MIDDLE_FRAG_NUMBER, 0, true, 0);
      }

      if (fd_head != NULL) {
        /* We have the complete reassembled payload. */
        rh_tvb = tvb_new_chain(tvb, fd_head->tvb_data);

        /* Add the defragmented data to the data
         * source list. */
        add_new_data_source(pinfo, rh_tvb,
            "Reassembled SNA BIU");
      }
    }
  }
  return rh_tvb;
}

#define SNA_FID01_ADDR_LEN  2

/* FID Types 0 and 1 */
static int
dissect_fid0_1(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
  proto_tree  *bf_tree;
  proto_item  *bf_item;
  uint8_t   th_0;

  const int bytes_in_header = 10;

  if (tree) {
    /* Byte 0 */
    th_0 = tvb_get_uint8(tvb, 0);
    bf_item = proto_tree_add_uint(tree, hf_sna_th_0, tvb, 0, 1,
        th_0);
    bf_tree = proto_item_add_subtree(bf_item, ett_sna_th_fid);

    proto_tree_add_uint(bf_tree, hf_sna_th_fid, tvb, 0, 1, th_0);
    proto_tree_add_uint(bf_tree, hf_sna_th_mpf, tvb, 0, 1, th_0);
    proto_tree_add_uint(bf_tree, hf_sna_th_efi, tvb, 0, 1, th_0);

    /* Byte 1 */
    proto_tree_add_item(tree, hf_sna_reserved, tvb, 1, 1, ENC_NA);

    /* Bytes 2-3 */
    proto_tree_add_item(tree, hf_sna_th_daf, tvb, 2, 2, ENC_BIG_ENDIAN);
  }

  /* Set DST addr */
  set_address_tvb(&pinfo->net_dst, sna_address_type, SNA_FID01_ADDR_LEN, tvb, 2);
  copy_address_shallow(&pinfo->dst, &pinfo->net_dst);

  proto_tree_add_item(tree, hf_sna_th_oaf, tvb, 4, 2, ENC_BIG_ENDIAN);

  /* Set SRC addr */
  set_address_tvb(&pinfo->net_src, sna_address_type, SNA_FID01_ADDR_LEN, tvb, 4);
  copy_address_shallow(&pinfo->src, &pinfo->net_src);

  proto_tree_add_item(tree, hf_sna_th_snf, tvb, 6, 2, ENC_BIG_ENDIAN);
  proto_tree_add_item(tree, hf_sna_th_dcf, tvb, 8, 2, ENC_BIG_ENDIAN);

  return bytes_in_header;
}

#define SNA_FID2_ADDR_LEN 1

/* FID Type 2 */
static int
dissect_fid2(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
       tvbuff_t **rh_tvb_ptr, next_dissection_t *continue_dissecting)
{
  proto_tree  *bf_tree;
  proto_item  *bf_item;
  uint8_t   th_0;
  unsigned int  mpf, id;

  const int bytes_in_header = 6;

  th_0 = tvb_get_uint8(tvb, 0);
  mpf = mpf_value(th_0);

  if (tree) {

    /* Byte 0 */
    bf_item = proto_tree_add_item(tree, hf_sna_th_0, tvb, 0, 1, ENC_BIG_ENDIAN);
    bf_tree = proto_item_add_subtree(bf_item, ett_sna_th_fid);

    proto_tree_add_item(bf_tree, hf_sna_th_fid, tvb, 0, 1, ENC_BIG_ENDIAN);
    proto_tree_add_item(bf_tree, hf_sna_th_mpf, tvb, 0, 1, ENC_BIG_ENDIAN);
    proto_tree_add_item(bf_tree, hf_sna_th_odai,tvb, 0, 1, ENC_BIG_ENDIAN);
    proto_tree_add_item(bf_tree, hf_sna_th_efi, tvb, 0, 1, ENC_BIG_ENDIAN);


    /* Byte 1 */
    proto_tree_add_item(tree, hf_sna_reserved, tvb, 1, 1, ENC_NA);

    /* Byte 2 */
    proto_tree_add_item(tree, hf_sna_th_daf, tvb, 2, 1, ENC_BIG_ENDIAN);
  }

  /* Set DST addr */
  set_address_tvb(&pinfo->net_dst, sna_address_type, SNA_FID2_ADDR_LEN, tvb, 2);
  copy_address_shallow(&pinfo->dst, &pinfo->net_dst);

  /* Byte 3 */
  proto_tree_add_item(tree, hf_sna_th_oaf, tvb, 3, 1, ENC_BIG_ENDIAN);

  /* Set SRC addr */
  set_address_tvb(&pinfo->net_src, sna_address_type, SNA_FID2_ADDR_LEN, tvb, 3);
  copy_address_shallow(&pinfo->src, &pinfo->net_src);

  id = tvb_get_ntohs(tvb, 4);
  proto_tree_add_item(tree, hf_sna_th_snf, tvb, 4, 2, ENC_BIG_ENDIAN);

  if (mpf != MPF_WHOLE_BIU && !sna_defragment) {
    if (mpf == MPF_FIRST_SEGMENT) {
      *continue_dissecting = rh_only;
      } else {
      *continue_dissecting = stop_here;
      }

    }
  else if (sna_defragment) {
    *rh_tvb_ptr = defragment_by_sequence(pinfo, tvb,
        bytes_in_header, mpf, id);
  }

  return bytes_in_header;
}

/* FID Type 3 */
static int
dissect_fid3(tvbuff_t *tvb, proto_tree *tree)
{
  proto_tree  *bf_tree;
  proto_item  *bf_item;
  uint8_t   th_0;

  const int bytes_in_header = 2;

  /* If we're not filling a proto_tree, return now */
  if (!tree)
    return bytes_in_header;

  th_0 = tvb_get_uint8(tvb, 0);

  /* Create the bitfield tree */
  bf_item = proto_tree_add_uint(tree, hf_sna_th_0, tvb, 0, 1, th_0);
  bf_tree = proto_item_add_subtree(bf_item, ett_sna_th_fid);

  proto_tree_add_uint(bf_tree, hf_sna_th_fid, tvb, 0, 1, th_0);
  proto_tree_add_uint(bf_tree, hf_sna_th_mpf, tvb, 0, 1, th_0);
  proto_tree_add_uint(bf_tree, hf_sna_th_efi, tvb, 0, 1, th_0);

  proto_tree_add_item(tree, hf_sna_th_lsid, tvb, 1, 1, ENC_BIG_ENDIAN);

  return bytes_in_header;
}

static int
dissect_fid4(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
  int   offset = 0;
  uint8_t   th_byte, mft;
  uint16_t    def, oef;
  uint32_t    dsaf, osaf;
  static int * const byte0_fields[] = {
    &hf_sna_th_fid,
    &hf_sna_th_tg_sweep,
    &hf_sna_th_er_vr_supp_ind,
    &hf_sna_th_vr_pac_cnt_ind,
    &hf_sna_th_ntwk_prty,
    NULL
  };
  static int * const byte1_fields[] = {
    &hf_sna_th_tgsf,
    &hf_sna_th_mft,
    &hf_sna_th_piubf,
    NULL
  };
  static int * const byte2_mft_fields[] = {
    &hf_sna_th_nlpoi,
    &hf_sna_th_nlp_cp,
    &hf_sna_th_ern,
    NULL
  };
  static int * const byte2_fields[] = {
    &hf_sna_th_iern,
    &hf_sna_th_ern,
    NULL
  };
  static int * const byte3_fields[] = {
    &hf_sna_th_vrn,
    &hf_sna_th_tpf,
    NULL
  };
  static int * const byte4_fields[] = {
    &hf_sna_th_vr_cwi,
    &hf_sna_th_tg_nonfifo_ind,
    &hf_sna_th_vr_sqti,
      /* I'm not sure about byte-order on this one... */
    &hf_sna_th_tg_snf,
    NULL
  };
  static int * const byte6_fields[] = {
    &hf_sna_th_vrprq,
    &hf_sna_th_vrprs,
    &hf_sna_th_vr_cwri,
    &hf_sna_th_vr_rwi,
      /* I'm not sure about byte-order on this one... */
    &hf_sna_th_vr_snf_send,
    NULL
  };
  static int * const byte16_fields[] = {
    &hf_sna_th_snai,
  /* We luck out here because in their infinite wisdom the SNA
   * architects placed the MPF and EFI fields in the same bitfield
   * locations, even though for FID4 they're not in byte 0.
   * Thank you IBM! */
    &hf_sna_th_mpf,
    &hf_sna_th_efi,
    NULL
  };

  struct sna_fid_type_4_addr *src, *dst;

  const int bytes_in_header = 26;

  /* If we're not filling a proto_tree, return now */
  if (!tree)
    return bytes_in_header;

  /* Byte 0 */
  proto_tree_add_bitmask(tree, tvb, offset, hf_sna_th_0,
             ett_sna_th_fid, byte0_fields, ENC_NA);

  offset += 1;
  th_byte = tvb_get_uint8(tvb, offset);

  /* Byte 1 */
  proto_tree_add_bitmask(tree, tvb, offset, hf_sna_th_byte1,
             ett_sna_th_fid, byte1_fields, ENC_NA);

  mft = th_byte & 0x04;
  offset += 1;

  /* Byte 2 */
  if (mft) {
    proto_tree_add_bitmask(tree, tvb, offset, hf_sna_th_byte2,
             ett_sna_th_fid, byte2_mft_fields, ENC_NA);
  } else {
    proto_tree_add_bitmask(tree, tvb, offset, hf_sna_th_byte2,
             ett_sna_th_fid, byte2_fields, ENC_NA);
  }

  offset += 1;

  /* Byte 3 */
  proto_tree_add_bitmask(tree, tvb, offset, hf_sna_th_byte3,
             ett_sna_th_fid, byte3_fields, ENC_NA);
  offset += 1;

  /* Bytes 4-5 */
  proto_tree_add_bitmask(tree, tvb, offset, hf_sna_th_byte4,
             ett_sna_th_fid, byte4_fields, ENC_BIG_ENDIAN);
  offset += 2;

  /* Create the bitfield tree */
  proto_tree_add_bitmask(tree, tvb, offset, hf_sna_th_byte6,
             ett_sna_th_fid, byte6_fields, ENC_BIG_ENDIAN);
  offset += 2;

  dsaf = tvb_get_ntohl(tvb, 8);
  /* Bytes 8-11 */
  proto_tree_add_uint(tree, hf_sna_th_dsaf, tvb, offset, 4, dsaf);

  offset += 4;

  osaf = tvb_get_ntohl(tvb, 12);
  /* Bytes 12-15 */
  proto_tree_add_uint(tree, hf_sna_th_osaf, tvb, offset, 4, osaf);

  offset += 4;

  /* Byte 16 */
  proto_tree_add_bitmask(tree, tvb, offset, hf_sna_th_byte16,
             ett_sna_th_fid, byte16_fields, ENC_NA);

  /* 1 for byte 16, 1 for byte 17 which is reserved */
  offset += 2;

  def = tvb_get_ntohs(tvb, 18);
  /* Bytes 18-25 */
  proto_tree_add_uint(tree, hf_sna_th_def, tvb, offset, 2, def);

  /* Addresses in FID 4 are discontiguous, sigh */
  dst = wmem_new0(pinfo->pool, struct sna_fid_type_4_addr);
  dst->saf = dsaf;
  dst->ef = def;
  set_address(&pinfo->net_dst, sna_address_type, SNA_FID_TYPE_4_ADDR_LEN, dst);
  copy_address_shallow(&pinfo->dst, &pinfo->net_dst);

  oef = tvb_get_ntohs(tvb, 20);
  proto_tree_add_uint(tree, hf_sna_th_oef, tvb, offset+2, 2, oef);

  /* Addresses in FID 4 are discontiguous, sigh */
  src = wmem_new0(pinfo->pool, struct sna_fid_type_4_addr);
  src->saf = osaf;
  src->ef = oef;
  set_address(&pinfo->net_src, sna_address_type, SNA_FID_TYPE_4_ADDR_LEN, src);
  copy_address_shallow(&pinfo->src, &pinfo->net_src);

  proto_tree_add_item(tree, hf_sna_th_snf, tvb, offset+4, 2, ENC_BIG_ENDIAN);
  proto_tree_add_item(tree, hf_sna_th_dcf, tvb, offset+6, 2, ENC_BIG_ENDIAN);

  return bytes_in_header;
}

/* FID Type 5 */
static int
dissect_fid5(tvbuff_t *tvb, proto_tree *tree)
{
  proto_tree  *bf_tree;
  proto_item  *bf_item;
  uint8_t   th_0;

  const int bytes_in_header = 12;

  /* If we're not filling a proto_tree, return now */
  if (!tree)
    return bytes_in_header;

  th_0 = tvb_get_uint8(tvb, 0);

  /* Create the bitfield tree */
  bf_item = proto_tree_add_uint(tree, hf_sna_th_0, tvb, 0, 1, th_0);
  bf_tree = proto_item_add_subtree(bf_item, ett_sna_th_fid);

  proto_tree_add_uint(bf_tree, hf_sna_th_fid, tvb, 0, 1, th_0);
  proto_tree_add_uint(bf_tree, hf_sna_th_mpf, tvb, 0, 1, th_0);
  proto_tree_add_uint(bf_tree, hf_sna_th_efi, tvb, 0, 1, th_0);

  proto_tree_add_item(tree, hf_sna_reserved, tvb, 1, 1, ENC_NA);
  proto_tree_add_item(tree, hf_sna_th_snf, tvb, 2, 2, ENC_BIG_ENDIAN);

  proto_tree_add_item(tree, hf_sna_th_sa, tvb, 4, 8, ENC_NA);

  return bytes_in_header;

}

/* FID Type f */
static int
dissect_fidf(tvbuff_t *tvb, proto_tree *tree)
{
  proto_tree  *bf_tree;
  proto_item  *bf_item;
  uint8_t   th_0;

  const int bytes_in_header = 26;

  /* If we're not filling a proto_tree, return now */
  if (!tree)
    return bytes_in_header;

  th_0 = tvb_get_uint8(tvb, 0);

  /* Create the bitfield tree */
  bf_item = proto_tree_add_uint(tree, hf_sna_th_0, tvb, 0, 1, th_0);
  bf_tree = proto_item_add_subtree(bf_item, ett_sna_th_fid);

  proto_tree_add_uint(bf_tree, hf_sna_th_fid, tvb, 0, 1, th_0);
  proto_tree_add_item(tree, hf_sna_reserved, tvb, 1, 1, ENC_NA);

  proto_tree_add_item(tree, hf_sna_th_cmd_fmt, tvb,  2, 1, ENC_BIG_ENDIAN);
  proto_tree_add_item(tree, hf_sna_th_cmd_type, tvb, 3, 1, ENC_BIG_ENDIAN);
  proto_tree_add_item(tree, hf_sna_th_cmd_sn, tvb,   4, 2, ENC_BIG_ENDIAN);

  /* Yup, bytes 6-23 are reserved! */
  proto_tree_add_item(tree, hf_sna_reserved, tvb, 6, 18, ENC_NA);

  proto_tree_add_item(tree, hf_sna_th_dcf, tvb, 24, 2, ENC_BIG_ENDIAN);

  return bytes_in_header;
}

static void
dissect_fid(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
      proto_tree *parent_tree)
{

  proto_tree  *th_tree = NULL, *rh_tree = NULL;
  proto_item  *th_ti = NULL, *rh_ti = NULL;
  uint8_t   th_fid;
  int   th_header_len = 0;
  int   offset, rh_offset;
  tvbuff_t  *rh_tvb = NULL;
  next_dissection_t continue_dissecting = everything;

  /* Transmission Header Format Identifier */
  th_fid = hi_nibble(tvb_get_uint8(tvb, 0));

  /* Summary information */
  col_add_str(pinfo->cinfo, COL_INFO,
        val_to_str(pinfo->pool, th_fid, sna_th_fid_vals, "Unknown FID: %01x"));

  if (tree) {
    /* --- TH --- */
    /* Don't bother setting length. We'll set it later after we
     * find the length of TH */
    th_ti = proto_tree_add_item(tree, hf_sna_th, tvb,  0, -1,
        ENC_NA);
    th_tree = proto_item_add_subtree(th_ti, ett_sna_th);
  }

  /* Get size of TH */
  switch(th_fid) {
    case 0x0:
    case 0x1:
      th_header_len = dissect_fid0_1(tvb, pinfo, th_tree);
      break;
    case 0x2:
      th_header_len = dissect_fid2(tvb, pinfo, th_tree,
          &rh_tvb, &continue_dissecting);
      break;
    case 0x3:
      th_header_len = dissect_fid3(tvb, th_tree);
      break;
    case 0x4:
      th_header_len = dissect_fid4(tvb, pinfo, th_tree);
      break;
    case 0x5:
      th_header_len = dissect_fid5(tvb, th_tree);
      break;
    case 0xf:
      th_header_len = dissect_fidf(tvb, th_tree);
      break;
    default:
      call_data_dissector(tvb_new_subset_remaining(tvb, 1), pinfo, parent_tree);
      return;
  }

  offset = th_header_len;

  /* Short-circuit ? */
  if (continue_dissecting == stop_here) {
    proto_tree_add_item(tree, hf_sna_biu_segment_data, tvb, offset, -1, ENC_NA);
    return;
  }

  /* If the FID dissector function didn't create an rh_tvb, then we just
   * use the rest of our tvbuff as the rh_tvb. */
  if (!rh_tvb)
    rh_tvb = tvb_new_subset_remaining(tvb, offset);
  rh_offset = 0;

  /* Process the rest of the SNA packet, starting with RH */
  if (tree) {
    proto_item_set_len(th_ti, th_header_len);

    /* --- RH --- */
    rh_ti = proto_tree_add_item(tree, hf_sna_rh, rh_tvb, rh_offset,
        RH_LEN, ENC_NA);
    rh_tree = proto_item_add_subtree(rh_ti, ett_sna_rh);
    dissect_rh(rh_tvb, rh_offset, rh_tree);
  }

  rh_offset += RH_LEN;

  if (tvb_offset_exists(rh_tvb, rh_offset)) {
    /* Short-circuit ? */
    if (continue_dissecting == rh_only) {
      proto_tree_add_item(tree, hf_sna_biu_segment_data, rh_tvb, rh_offset, -1, ENC_NA);
      return;
    }

    call_data_dissector(tvb_new_subset_remaining(rh_tvb, rh_offset),
        pinfo, parent_tree);
  }
}

/* --------------------------------------------------------------------
 * Chapter 5 Request/Response Headers (RHs)
 * --------------------------------------------------------------------
 */

static void
dissect_rh(tvbuff_t *tvb, int offset, proto_tree *tree)
{
  bool  is_response;
  uint8_t   rh_0;
  static int * const sna_rh_fields[] = {
    &hf_sna_rh_rri,
    &hf_sna_rh_ru_category,
    &hf_sna_rh_fi,
    &hf_sna_rh_sdi,
    &hf_sna_rh_bci,
    &hf_sna_rh_eci,
    NULL
  };
  static int * const sna_rh_1_req_fields[] = {
    &hf_sna_rh_dr1,
    &hf_sna_rh_lcci,
    &hf_sna_rh_dr2,
    &hf_sna_rh_eri,
    &hf_sna_rh_rlwi,
    &hf_sna_rh_qri,
    &hf_sna_rh_pi,
    NULL
  };
  static int * const sna_rh_1_rsp_fields[] = {
    &hf_sna_rh_dr1,
    &hf_sna_rh_dr2,
    &hf_sna_rh_rti,
    &hf_sna_rh_qri,
    &hf_sna_rh_pi,
    NULL
  };
  static int * const sna_rh_2_req_fields[] = {
    &hf_sna_rh_bbi,
    &hf_sna_rh_ebi,
    &hf_sna_rh_cdi,
    &hf_sna_rh_csi,
    &hf_sna_rh_edi,
    &hf_sna_rh_pdi,
    &hf_sna_rh_cebi,
    NULL
  };

  if (!tree)
    return;

  /* Create the bitfield tree for byte 0*/
  rh_0 = tvb_get_uint8(tvb, offset);
  is_response = (rh_0 & 0x80);

  proto_tree_add_bitmask(tree, tvb, offset, hf_sna_rh_0,
             ett_sna_rh_0, sna_rh_fields, ENC_BIG_ENDIAN);
  offset += 1;

  /* Create the bitfield tree for byte 1*/
  if (is_response) {
    proto_tree_add_bitmask(tree, tvb, offset, hf_sna_rh_1,
             ett_sna_rh_1, sna_rh_1_rsp_fields, ENC_BIG_ENDIAN);
  } else {
    proto_tree_add_bitmask(tree, tvb, offset, hf_sna_rh_1,
             ett_sna_rh_1, sna_rh_1_req_fields, ENC_BIG_ENDIAN);
  }
  offset += 1;

  /* Create the bitfield tree for byte 2*/
  if (!is_response) {
    proto_tree_add_bitmask(tree, tvb, offset, hf_sna_rh_2,
             ett_sna_rh_2, sna_rh_2_req_fields, ENC_BIG_ENDIAN);
  } else {
    proto_tree_add_item(tree, hf_sna_rh_2, tvb, offset, 1, ENC_BIG_ENDIAN);
  }

  /* XXX - check for sdi. If true, the next 4 bytes will be sense data */
}

/* --------------------------------------------------------------------
 * Chapter 6 Request/Response Units (RUs)
 * --------------------------------------------------------------------
 */

/* --------------------------------------------------------------------
 * Chapter 9 Common Fields
 * --------------------------------------------------------------------
 */

static void
// NOLINTNEXTLINE(misc-no-recursion)
dissect_control_05hpr(tvbuff_t *tvb, proto_tree *tree, int hpr,
          enum parse parse)
{
  uint16_t    offset, len, pad;
  static int * const sna_control_05hpr_fields[] = {
    &hf_sna_control_05_ptp,
    NULL
  };

  if (!tree)
    return;

  proto_tree_add_bitmask(tree, tvb, 2, hf_sna_control_05_type,
             ett_sna_control_05hpr_type, sna_control_05hpr_fields, ENC_BIG_ENDIAN);

  proto_tree_add_item(tree, hf_sna_reserved, tvb, 3, 1, ENC_NA);

  offset = 4;

  while (tvb_offset_exists(tvb, offset)) {
    if (parse == LT) {
      len = tvb_get_uint8(tvb, offset+0);
    } else {
      len = tvb_get_uint8(tvb, offset+1);
    }
    if (len) {
      // We recurse here, but we'll run out of packet before we run out of stack.
      dissect_sna_control(tvb, offset, len, tree, hpr, parse);
      pad = (len+3) & 0xfffc;
      if (pad > len) {
        proto_tree_add_item(tree, hf_sna_padding, tvb, offset+len, pad-len, ENC_NA);
      }
      offset += pad;
    } else {
      return;
    }
  }
}

static void
dissect_control_05(tvbuff_t *tvb, proto_tree *tree)
{
  if(!tree)
    return;

  proto_tree_add_item(tree, hf_sna_control_05_delay, tvb, 2, 2, ENC_BIG_ENDIAN);
}

static void
dissect_control_0e(tvbuff_t *tvb, proto_tree *tree)
{
  int len;

  if (!tree)
    return;

  proto_tree_add_item(tree, hf_sna_control_0e_type, tvb, 2, 1, ENC_BIG_ENDIAN);

  len = tvb_reported_length_remaining(tvb, 3);
  if (len <= 0)
    return;

  proto_tree_add_item(tree, hf_sna_control_0e_value, tvb, 3, len, ENC_EBCDIC);
}

static void
// NOLINTNEXTLINE(misc-no-recursion)
dissect_sna_control(tvbuff_t *parent_tvb, int offset, int control_len,
    proto_tree *tree, int hpr, enum parse parse)
{
  tvbuff_t  *tvb;
  proto_tree  *sub_tree;
  int   len, key;
  int   ett;

  tvb = tvb_new_subset_length(parent_tvb, offset, control_len);

  sub_tree = NULL;

  if (parse == LT) {
    len = tvb_get_uint8(tvb, 0);
    key = tvb_get_uint8(tvb, 1);
  } else {
    key = tvb_get_uint8(tvb, 0);
    len = tvb_get_uint8(tvb, 1);
  }
  ett = ett_sna_control_un;

  if (tree) {
    if (key == 5) {
       if (hpr) ett = ett_sna_control_05hpr;
       else ett = ett_sna_control_05;
    }
    if (key == 0x0e) ett = ett_sna_control_0e;

    if (((key == 0) || (key == 3) || (key == 5)) && hpr)
      sub_tree = proto_tree_add_subtree(tree, tvb, 0, -1, ett, NULL,
          val_to_str_const(key, sna_control_hpr_vals,
          "Unknown Control Vector"));
    else
      sub_tree = proto_tree_add_subtree(tree, tvb, 0, -1, ett, NULL,
          val_to_str_const(key, sna_control_vals,
          "Unknown Control Vector"));
    if (parse == LT) {
      proto_tree_add_uint(sub_tree, hf_sna_control_len,
          tvb, 0, 1, len);
      if (((key == 0) || (key == 3) || (key == 5)) && hpr)
        proto_tree_add_uint(sub_tree,
            hf_sna_control_hprkey, tvb, 1, 1, key);
      else
        proto_tree_add_uint(sub_tree,
            hf_sna_control_key, tvb, 1, 1, key);
    } else {
      if (((key == 0) || (key == 3) || (key == 5)) && hpr)
        proto_tree_add_uint(sub_tree,
            hf_sna_control_hprkey, tvb, 0, 1, key);
      else
        proto_tree_add_uint(sub_tree,
            hf_sna_control_key, tvb, 0, 1, key);
      proto_tree_add_uint(sub_tree, hf_sna_control_len,
          tvb, 1, 1, len);
    }
  }
  switch(key) {
    case 0x05:
      if (hpr)
        // We recurse here, but we'll run out of packet before we run out of stack.
        dissect_control_05hpr(tvb, sub_tree, hpr,
            parse);
      else
        dissect_control_05(tvb, sub_tree);
      break;
    case 0x0e:
      dissect_control_0e(tvb, sub_tree);
      break;
  }
}

/* --------------------------------------------------------------------
 * Chapter 11 Function Management (FM) Headers
 * --------------------------------------------------------------------
 */

/* --------------------------------------------------------------------
 * Chapter 12 Presentation Services (PS) Headers
 * --------------------------------------------------------------------
 */

/* --------------------------------------------------------------------
 * Chapter 13 GDS Variables
 * --------------------------------------------------------------------
 */

static void
dissect_gds(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
      proto_tree *parent_tree)
{
  uint16_t    length;
  int   cont;
  int   offset = 0;
  proto_item  *pi;
  proto_tree  *subtree;
  bool  first_ll = true;

  do {
    length = tvb_get_ntohs(tvb, offset) & 0x7fff;
    cont   = (tvb_get_ntohs(tvb, offset) & 0x8000) ? 1 : 0;

    pi = proto_tree_add_item(tree, hf_sna_gds, tvb, offset, -1, ENC_NA);
    subtree = proto_item_add_subtree(pi, ett_sna_gds);
    proto_tree_add_item(subtree, hf_sna_gds_len, tvb, offset, 2, ENC_BIG_ENDIAN);
    proto_tree_add_item(subtree, hf_sna_gds_cont, tvb, offset, 2, ENC_BIG_ENDIAN);
    if (length < 2 ) /* escape sequence */
      return;
    offset += 2;
    length -= 2;
    if (first_ll) {
      proto_tree_add_item(subtree, hf_sna_gds_type, tvb, offset, 2, ENC_BIG_ENDIAN);
      offset += 2;
      length -= 2;
      first_ll = false;
    }
    if (length > 0) {
      proto_tree_add_item(subtree, hf_sna_gds_info, tvb, offset, length, ENC_NA);
      offset += length;
    }
  } while(cont);
  proto_item_set_len(pi, offset);
  if (tvb_offset_exists(tvb, offset))
    call_data_dissector(tvb_new_subset_remaining(tvb, offset), pinfo, parent_tree);
}

/* --------------------------------------------------------------------
 * General stuff
 * --------------------------------------------------------------------
 */

static int
dissect_sna(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
  uint8_t   fid;
  proto_tree  *sna_tree = NULL;
  proto_item  *sna_ti = NULL;

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

  /* SNA data should be printed in EBCDIC, not ASCII */
  pinfo->fd->encoding = PACKET_CHAR_ENC_CHAR_EBCDIC;

  if (tree) {

    /* Don't bother setting length. We'll set it later after we find
     * the lengths of TH/RH/RU */
    sna_ti = proto_tree_add_item(tree, proto_sna, tvb, 0, -1,
        ENC_NA);
    sna_tree = proto_item_add_subtree(sna_ti, ett_sna);
  }

  /* Transmission Header Format Identifier */
  fid = hi_nibble(tvb_get_uint8(tvb, 0));
  switch(fid) {
    case 0xa: /* HPR Network Layer Packet */
    case 0xb:
    case 0xc:
    case 0xd:
      dissect_nlp(tvb, pinfo, sna_tree, tree);
      break;
    default:
      dissect_fid(tvb, pinfo, sna_tree, tree);
  }
  return tvb_captured_length(tvb);
}

static int
dissect_sna_xid(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
  proto_tree  *sna_tree = NULL;
  proto_item  *sna_ti = NULL;

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

  /* SNA data should be printed in EBCDIC, not ASCII */
  pinfo->fd->encoding = PACKET_CHAR_ENC_CHAR_EBCDIC;

  if (tree) {

    /* Don't bother setting length. We'll set it later after we find
     * the lengths of XID */
    sna_ti = proto_tree_add_item(tree, proto_sna_xid, tvb, 0, -1,
        ENC_NA);
    sna_tree = proto_item_add_subtree(sna_ti, ett_sna);
  }
  dissect_xid(tvb, pinfo, sna_tree, tree);
  return tvb_captured_length(tvb);
}


void
proto_register_sna(void)
{
  static hf_register_info hf[] = {
    { &hf_sna_th,
      { "Transmission Header", "sna.th", FT_NONE, BASE_NONE,
        NULL, 0x0, NULL, HFILL }},

    { &hf_sna_th_0,
      { "Transmission Header Byte 0", "sna.th.0", FT_UINT8, BASE_HEX,
        NULL, 0x0,
        "TH Byte 0", HFILL }},

    { &hf_sna_th_fid,
      { "Format Identifier", "sna.th.fid", FT_UINT8, BASE_HEX,
        VALS(sna_th_fid_vals), 0xf0, NULL, HFILL }},

    { &hf_sna_th_mpf,
      { "Mapping Field", "sna.th.mpf", FT_UINT8,
        BASE_DEC, VALS(sna_th_mpf_vals), 0x0c, NULL, HFILL }},

    { &hf_sna_th_odai,
      { "ODAI Assignment Indicator", "sna.th.odai", FT_UINT8,
        BASE_DEC, NULL, 0x02, NULL, HFILL }},

    { &hf_sna_th_efi,
      { "Expedited Flow Indicator", "sna.th.efi", FT_UINT8,
        BASE_DEC, VALS(sna_th_efi_vals), 0x01, NULL, HFILL }},

    { &hf_sna_th_daf,
      { "Destination Address Field", "sna.th.daf", FT_UINT16,
        BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_th_oaf,
      { "Origin Address Field", "sna.th.oaf", FT_UINT16, BASE_HEX,
        NULL, 0x0, NULL, HFILL }},

    { &hf_sna_th_snf,
      { "Sequence Number Field", "sna.th.snf", FT_UINT16, BASE_DEC,
        NULL, 0x0, NULL, HFILL }},

    { &hf_sna_th_dcf,
      { "Data Count Field", "sna.th.dcf", FT_UINT16, BASE_DEC,
        NULL, 0x0, NULL, HFILL }},

    { &hf_sna_th_lsid,
      { "Local Session Identification", "sna.th.lsid", FT_UINT8,
        BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_th_tg_sweep,
      { "Transmission Group Sweep", "sna.th.tg_sweep", FT_UINT8,
        BASE_DEC, VALS(sna_th_tg_sweep_vals), 0x08, NULL, HFILL }},

    { &hf_sna_th_er_vr_supp_ind,
      { "ER and VR Support Indicator", "sna.th.er_vr_supp_ind",
        FT_UINT8, BASE_DEC, VALS(sna_th_er_vr_supp_ind_vals),
        0x04, NULL, HFILL }},

    { &hf_sna_th_vr_pac_cnt_ind,
      { "Virtual Route Pacing Count Indicator",
        "sna.th.vr_pac_cnt_ind", FT_UINT8, BASE_DEC,
        VALS(sna_th_vr_pac_cnt_ind_vals), 0x02, NULL, HFILL }},

    { &hf_sna_th_ntwk_prty,
      { "Network Priority", "sna.th.ntwk_prty", FT_UINT8, BASE_DEC,
        VALS(sna_th_ntwk_prty_vals), 0x01, NULL, HFILL }},

    { &hf_sna_th_tgsf,
      { "Transmission Group Segmenting Field", "sna.th.tgsf",
        FT_UINT8, BASE_HEX, VALS(sna_th_tgsf_vals), 0xc0,
        NULL, HFILL }},

    { &hf_sna_th_mft,
      { "MPR FID4 Type", "sna.th.mft", FT_BOOLEAN, 8,
        NULL, 0x04, NULL, HFILL }},

    { &hf_sna_th_piubf,
      { "PIU Blocking Field", "sna.th.piubf", FT_UINT8, BASE_HEX,
        VALS(sna_th_piubf_vals), 0x03, NULL, HFILL }},

    { &hf_sna_th_iern,
      { "Initial Explicit Route Number", "sna.th.iern", FT_UINT8,
        BASE_DEC, NULL, 0xf0, NULL, HFILL }},

    { &hf_sna_th_nlpoi,
      { "NLP Offset Indicator", "sna.th.nlpoi", FT_UINT8, BASE_DEC,
        VALS(sna_th_nlpoi_vals), 0x80, NULL, HFILL }},

    { &hf_sna_th_nlp_cp,
      { "NLP Count or Padding", "sna.th.nlp_cp", FT_UINT8, BASE_DEC,
        NULL, 0x70, NULL, HFILL }},

    { &hf_sna_th_ern,
      { "Explicit Route Number", "sna.th.ern", FT_UINT8, BASE_DEC,
        NULL, 0x0f, NULL, HFILL }},

    { &hf_sna_th_vrn,
      { "Virtual Route Number", "sna.th.vrn", FT_UINT8, BASE_DEC,
        NULL, 0xf0, NULL, HFILL }},

    { &hf_sna_th_tpf,
      { "Transmission Priority Field", "sna.th.tpf", FT_UINT8,
        BASE_HEX, VALS(sna_th_tpf_vals), 0x03, NULL, HFILL }},

    { &hf_sna_th_vr_cwi,
      { "Virtual Route Change Window Indicator", "sna.th.vr_cwi",
        FT_UINT16, BASE_DEC, VALS(sna_th_vr_cwi_vals), 0x8000,
        NULL, HFILL }},

    { &hf_sna_th_tg_nonfifo_ind,
      { "Transmission Group Non-FIFO Indicator",
        "sna.th.tg_nonfifo_ind", FT_BOOLEAN, 16,
        TFS(&sna_th_tg_nonfifo_ind_truth), 0x4000, NULL, HFILL }},

    { &hf_sna_th_vr_sqti,
      { "Virtual Route Sequence and Type Indicator", "sna.th.vr_sqti",
        FT_UINT16, BASE_HEX, VALS(sna_th_vr_sqti_vals), 0x3000,
        NULL, HFILL }},

    { &hf_sna_th_tg_snf,
      { "Transmission Group Sequence Number Field", "sna.th.tg_snf",
        FT_UINT16, BASE_DEC, NULL, 0x0fff, NULL, HFILL }},

    { &hf_sna_th_vrprq,
      { "Virtual Route Pacing Request", "sna.th.vrprq", FT_BOOLEAN,
        16, TFS(&sna_th_vrprq_truth), 0x8000, NULL, HFILL }},

    { &hf_sna_th_vrprs,
      { "Virtual Route Pacing Response", "sna.th.vrprs", FT_BOOLEAN,
        16, TFS(&sna_th_vrprs_truth), 0x4000, NULL, HFILL }},

    { &hf_sna_th_vr_cwri,
      { "Virtual Route Change Window Reply Indicator",
        "sna.th.vr_cwri", FT_UINT16, BASE_DEC,
        VALS(sna_th_vr_cwri_vals), 0x2000, NULL, HFILL }},

    { &hf_sna_th_vr_rwi,
      { "Virtual Route Reset Window Indicator", "sna.th.vr_rwi",
        FT_BOOLEAN, 16, TFS(&sna_th_vr_rwi_truth), 0x1000,
        NULL, HFILL }},

    { &hf_sna_th_vr_snf_send,
      { "Virtual Route Send Sequence Number Field",
        "sna.th.vr_snf_send", FT_UINT16, BASE_DEC, NULL, 0x0fff,
        NULL, HFILL }},

    { &hf_sna_th_dsaf,
      { "Destination Subarea Address Field", "sna.th.dsaf",
        FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_th_osaf,
      { "Origin Subarea Address Field", "sna.th.osaf", FT_UINT32,
        BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_th_snai,
      { "SNA Indicator", "sna.th.snai", FT_BOOLEAN, 8, NULL, 0x10,
        "Used to identify whether the PIU originated or is destined for an SNA or non-SNA device.", HFILL }},

    { &hf_sna_th_def,
      { "Destination Element Field", "sna.th.def", FT_UINT16,
        BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_th_oef,
      { "Origin Element Field", "sna.th.oef", FT_UINT16, BASE_HEX,
        NULL, 0x0, NULL, HFILL }},

    { &hf_sna_th_sa,
      { "Session Address", "sna.th.sa", FT_BYTES, BASE_NONE,
        NULL, 0x0, NULL, HFILL }},

    { &hf_sna_th_cmd_fmt,
      { "Command Format", "sna.th.cmd_fmt", FT_UINT8, BASE_HEX,
        NULL, 0x0, NULL, HFILL }},

    { &hf_sna_th_cmd_type,
      { "Command Type", "sna.th.cmd_type", FT_UINT8, BASE_HEX,
        NULL, 0x0, NULL, HFILL }},

    { &hf_sna_th_cmd_sn,
      { "Command Sequence Number", "sna.th.cmd_sn", FT_UINT16,
        BASE_DEC, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_th_byte1,
      { "Transmission Header Bytes 1", "sna.th.byte1", FT_UINT8,
        BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_th_byte2,
      { "Transmission Header Bytes 2", "sna.th.byte2", FT_UINT8,
        BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_th_byte3,
      { "Transmission Header Bytes 3", "sna.th.byte3", FT_UINT8,
        BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_th_byte4,
      { "Transmission Header Bytes 4-5", "sna.th.byte4", FT_UINT16,
        BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_th_byte6,
      { "Transmission Header Bytes 6-7", "sna.th.byte6", FT_UINT16,
        BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_th_byte16,
      { "Transmission Header Bytes 16", "sna.th.byte16", FT_UINT8,
        BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_nlp_nhdr,
      { "Network Layer Packet Header", "sna.nlp.nhdr", FT_NONE,
        BASE_NONE, NULL, 0x0, "NHDR", HFILL }},

    { &hf_sna_nlp_nhdr_0,
      { "Network Layer Packet Header Byte 0", "sna.nlp.nhdr.0",
        FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_nlp_nhdr_1,
      { "Network Layer Packet Header Byte 1", "sna.nlp.nhdr.1",
        FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_nlp_sm,
      { "Switching Mode Field", "sna.nlp.nhdr.sm", FT_UINT8,
        BASE_HEX, VALS(sna_nlp_sm_vals), 0xe0, NULL, HFILL }},

    { &hf_sna_nlp_tpf,
      { "Transmission Priority Field", "sna.nlp.nhdr.tpf", FT_UINT8,
        BASE_HEX, VALS(sna_th_tpf_vals), 0x06, NULL, HFILL }},

    { &hf_sna_nlp_ft,
      { "Function Type", "sna.nlp.nhdr.ft", FT_UINT8, BASE_HEX,
        VALS(sna_nlp_ft_vals), 0xF0, NULL, HFILL }},

    { &hf_sna_nlp_tspi,
      { "Time Sensitive Packet Indicator", "sna.nlp.nhdr.tspi",
        FT_BOOLEAN, 8, TFS(&sna_nlp_tspi_truth), 0x08, NULL, HFILL }},

    { &hf_sna_nlp_slowdn1,
      { "Slowdown 1", "sna.nlp.nhdr.slowdn1", FT_BOOLEAN, 8,
        TFS(&sna_nlp_slowdn1_truth), 0x04, NULL, HFILL }},

    { &hf_sna_nlp_slowdn2,
      { "Slowdown 2", "sna.nlp.nhdr.slowdn2", FT_BOOLEAN, 8,
        TFS(&sna_nlp_slowdn2_truth), 0x02, NULL, HFILL }},

    { &hf_sna_nlp_fra,
      { "Function Routing Address Entry", "sna.nlp.nhdr.fra",
        FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }},

    { &hf_sna_nlp_anr,
      { "Automatic Network Routing Entry", "sna.nlp.nhdr.anr",
        FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }},

    { &hf_sna_nlp_frh,
      { "Transmission Priority Field", "sna.nlp.frh", FT_UINT8,
        BASE_HEX, VALS(sna_nlp_frh_vals), 0, NULL, HFILL }},

    { &hf_sna_nlp_thdr,
      { "RTP Transport Header", "sna.nlp.thdr", FT_NONE, BASE_NONE,
        NULL, 0x0, "THDR", HFILL }},

    { &hf_sna_nlp_tcid,
      { "Transport Connection Identifier", "sna.nlp.thdr.tcid",
        FT_BYTES, BASE_NONE, NULL, 0x0, "TCID", HFILL }},

    { &hf_sna_nlp_thdr_8,
      { "RTP Transport Packet Header Byte 8", "sna.nlp.thdr.8",
        FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_nlp_setupi,
      { "Setup Indicator", "sna.nlp.thdr.setupi", FT_BOOLEAN, 8,
        TFS(&sna_nlp_setupi_truth), 0x40, NULL, HFILL }},

    { &hf_sna_nlp_somi,
      { "Start Of Message Indicator", "sna.nlp.thdr.somi",
        FT_BOOLEAN, 8, TFS(&sna_nlp_somi_truth), 0x20, NULL, HFILL }},

    { &hf_sna_nlp_eomi,
      { "End Of Message Indicator", "sna.nlp.thdr.eomi", FT_BOOLEAN,
        8, TFS(&sna_nlp_eomi_truth), 0x10, NULL, HFILL }},

    { &hf_sna_nlp_sri,
      { "Session Request Indicator", "sna.nlp.thdr.sri", FT_BOOLEAN,
        8, TFS(&sna_nlp_sri_truth), 0x08, NULL, HFILL }},

    { &hf_sna_nlp_rasapi,
      { "Reply ASAP Indicator", "sna.nlp.thdr.rasapi", FT_BOOLEAN,
        8, TFS(&sna_nlp_rasapi_truth), 0x04, NULL, HFILL }},

    { &hf_sna_nlp_retryi,
      { "Retry Indicator", "sna.nlp.thdr.retryi", FT_BOOLEAN,
        8, TFS(&sna_nlp_retryi_truth), 0x02, NULL, HFILL }},

    { &hf_sna_nlp_thdr_9,
      { "RTP Transport Packet Header Byte 9", "sna.nlp.thdr.9",
        FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_nlp_lmi,
      { "Last Message Indicator", "sna.nlp.thdr.lmi", FT_BOOLEAN,
        8, TFS(&sna_nlp_lmi_truth), 0x80, NULL, HFILL }},

    { &hf_sna_nlp_cqfi,
      { "Connection Qualifier Field Indicator", "sna.nlp.thdr.cqfi",
        FT_BOOLEAN, 8, TFS(&sna_nlp_cqfi_truth), 0x08, NULL, HFILL }},

    { &hf_sna_nlp_osi,
      { "Optional Segments Present Indicator", "sna.nlp.thdr.osi",
        FT_BOOLEAN, 8, TFS(&sna_nlp_osi_truth), 0x04, NULL, HFILL }},

    { &hf_sna_nlp_offset,
      { "Data Offset/4", "sna.nlp.thdr.offset", FT_UINT16, BASE_HEX,
        NULL, 0x0, "Data Offset in Words", HFILL }},

    { &hf_sna_nlp_dlf,
      { "Data Length Field", "sna.nlp.thdr.dlf", FT_UINT32, BASE_HEX,
        NULL, 0x0, NULL, HFILL }},

    { &hf_sna_nlp_bsn,
      { "Byte Sequence Number", "sna.nlp.thdr.bsn", FT_UINT32,
        BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_nlp_opti_len,
      { "Optional Segment Length/4", "sna.nlp.thdr.optional.len",
        FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_nlp_opti_type,
      { "Optional Segment Type", "sna.nlp.thdr.optional.type",
        FT_UINT8, BASE_HEX, VALS(sna_nlp_opti_vals), 0x0, NULL,
        HFILL }},

    { &hf_sna_nlp_opti_0d_version,
      { "Version", "sna.nlp.thdr.optional.0d.version",
        FT_UINT16, BASE_HEX, VALS(sna_nlp_opti_0d_version_vals),
        0, NULL, HFILL }},

    { &hf_sna_nlp_opti_0d_4,
      { "Connection Setup Byte 4", "sna.nlp.thdr.optional.0e.4",
        FT_UINT8, BASE_HEX, NULL, 0, NULL, HFILL }},

    { &hf_sna_nlp_opti_0d_target,
      { "Target Resource ID Present",
        "sna.nlp.thdr.optional.0d.target",
        FT_BOOLEAN, 8, NULL, 0x80, NULL, HFILL }},

    { &hf_sna_nlp_opti_0d_arb,
      { "ARB Flow Control", "sna.nlp.thdr.optional.0d.arb",
        FT_BOOLEAN, 8, NULL, 0x10, NULL, HFILL }},

    { &hf_sna_nlp_opti_0d_reliable,
      { "Reliable Connection", "sna.nlp.thdr.optional.0d.reliable",
        FT_BOOLEAN, 8, NULL, 0x08, NULL, HFILL }},

    { &hf_sna_nlp_opti_0d_dedicated,
      { "Dedicated RTP Connection",
        "sna.nlp.thdr.optional.0d.dedicated",
        FT_BOOLEAN, 8, NULL, 0x04, NULL, HFILL }},

    { &hf_sna_nlp_opti_0e_stat,
      { "Status", "sna.nlp.thdr.optional.0e.stat",
        FT_UINT8, BASE_HEX, NULL, 0, NULL, HFILL }},

    { &hf_sna_nlp_opti_0e_gap,
      { "Gap Detected", "sna.nlp.thdr.optional.0e.gap",
        FT_BOOLEAN, 8, NULL, 0x80, NULL, HFILL }},

    { &hf_sna_nlp_opti_0e_idle,
      { "RTP Idle Packet", "sna.nlp.thdr.optional.0e.idle",
        FT_BOOLEAN, 8, NULL, 0x40, NULL, HFILL }},

    { &hf_sna_nlp_opti_0e_nabsp,
      { "Number Of ABSP", "sna.nlp.thdr.optional.0e.nabsp",
        FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_nlp_opti_0e_sync,
      { "Status Report Number", "sna.nlp.thdr.optional.0e.sync",
        FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_nlp_opti_0e_echo,
      { "Status Acknowledge Number", "sna.nlp.thdr.optional.0e.echo",
        FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_nlp_opti_0e_rseq,
      { "Received Sequence Number", "sna.nlp.thdr.optional.0e.rseq",
        FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL }},

#if 0
    { &hf_sna_nlp_opti_0e_abspbeg,
      { "ABSP Begin", "sna.nlp.thdr.optional.0e.abspbeg",
        FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL }},
#endif

#if 0
    { &hf_sna_nlp_opti_0e_abspend,
      { "ABSP End", "sna.nlp.thdr.optional.0e.abspend",
        FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL }},
#endif

    { &hf_sna_nlp_opti_0f_bits,
      { "Client Bits", "sna.nlp.thdr.optional.0f.bits",
        FT_UINT16, BASE_HEX, VALS(sna_nlp_opti_0f_bits_vals),
        0x0, NULL, HFILL }},

    { &hf_sna_nlp_opti_10_tcid,
      { "Transport Connection Identifier",
        "sna.nlp.thdr.optional.10.tcid",
        FT_BYTES, BASE_NONE, NULL, 0x0, "TCID", HFILL }},

    { &hf_sna_nlp_opti_12_sense,
      { "Sense Data", "sna.nlp.thdr.optional.12.sense",
        FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_nlp_opti_14_si_len,
      { "Length", "sna.nlp.thdr.optional.14.si.len",
        FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_nlp_opti_14_si_key,
      { "Key", "sna.nlp.thdr.optional.14.si.key",
        FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_nlp_opti_14_si_2,
      { "Switching Information Byte 2",
        "sna.nlp.thdr.optional.14.si.2",
        FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_nlp_opti_14_si_refifo,
      { "Resequencing (REFIFO) Indicator",
        "sna.nlp.thdr.optional.14.si.refifo",
        FT_BOOLEAN, 8, NULL, 0x80, NULL, HFILL }},

    { &hf_sna_nlp_opti_14_si_mobility,
      { "Mobility Indicator",
        "sna.nlp.thdr.optional.14.si.mobility",
        FT_BOOLEAN, 8, NULL, 0x40, NULL, HFILL }},

    { &hf_sna_nlp_opti_14_si_dirsearch,
      { "Directory Search Required on Path Switch Indicator",
        "sna.nlp.thdr.optional.14.si.dirsearch",
        FT_BOOLEAN, 8, NULL, 0x20, NULL, HFILL }},

    { &hf_sna_nlp_opti_14_si_limitres,
      { "Limited Resource Link Indicator",
        "sna.nlp.thdr.optional.14.si.limitres",
        FT_BOOLEAN, 8, NULL, 0x10, NULL, HFILL }},

    { &hf_sna_nlp_opti_14_si_ncescope,
      { "NCE Scope Indicator",
        "sna.nlp.thdr.optional.14.si.ncescope",
        FT_BOOLEAN, 8, NULL, 0x08, NULL, HFILL }},

    { &hf_sna_nlp_opti_14_si_mnpsrscv,
      { "MNPS RSCV Retention Indicator",
        "sna.nlp.thdr.optional.14.si.mnpsrscv",
        FT_BOOLEAN, 8, NULL, 0x04, NULL, HFILL }},

    { &hf_sna_nlp_opti_14_si_maxpsize,
      { "Maximum Packet Size On Return Path",
        "sna.nlp.thdr.optional.14.si.maxpsize",
        FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_nlp_opti_14_si_switch,
      { "Path Switch Time", "sna.nlp.thdr.optional.14.si.switch",
        FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_nlp_opti_14_si_alive,
      { "RTP Alive Timer", "sna.nlp.thdr.optional.14.si.alive",
        FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_nlp_opti_14_rr_len,
      { "Length", "sna.nlp.thdr.optional.14.rr.len",
        FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_nlp_opti_14_rr_key,
      { "Key", "sna.nlp.thdr.optional.14.rr.key",
        FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_nlp_opti_14_rr_2,
      { "Return Route TG Descriptor Byte 2",
        "sna.nlp.thdr.optional.14.rr.2",
        FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_nlp_opti_14_rr_bfe,
      { "BF Entry Indicator",
        "sna.nlp.thdr.optional.14.rr.bfe",
        FT_BOOLEAN, 8, NULL, 0x80, NULL, HFILL }},

    { &hf_sna_nlp_opti_14_rr_num,
      { "Number Of TG Control Vectors",
        "sna.nlp.thdr.optional.14.rr.num",
        FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_nlp_opti_22_2,
      { "Adaptive Rate Based Segment Byte 2",
        "sna.nlp.thdr.optional.22.2",
        FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_nlp_opti_22_type,
      { "Message Type",
        "sna.nlp.thdr.optional.22.type",
        FT_UINT8, BASE_HEX,
        VALS(sna_nlp_opti_22_type_vals), 0xc0, NULL, HFILL }},

    { &hf_sna_nlp_opti_22_raa,
      { "Rate Adjustment Action",
        "sna.nlp.thdr.optional.22.raa",
        FT_UINT8, BASE_HEX,
        VALS(sna_nlp_opti_22_raa_vals), 0x38, NULL, HFILL }},

    { &hf_sna_nlp_opti_22_parity,
      { "Parity Indicator",
        "sna.nlp.thdr.optional.22.parity",
        FT_BOOLEAN, 8, NULL, 0x04, NULL, HFILL }},

    { &hf_sna_nlp_opti_22_arb,
      { "ARB Mode",
        "sna.nlp.thdr.optional.22.arb",
        FT_UINT8, BASE_HEX,
        VALS(sna_nlp_opti_22_arb_vals), 0x03, NULL, HFILL }},

    { &hf_sna_nlp_opti_22_3,
      { "Adaptive Rate Based Segment Byte 3",
        "sna.nlp.thdr.optional.22.3",
        FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_nlp_opti_22_ratereq,
      { "Rate Request Correlator",
        "sna.nlp.thdr.optional.22.ratereq",
        FT_UINT8, BASE_DEC, NULL, 0xf0, NULL, HFILL }},

    { &hf_sna_nlp_opti_22_raterep,
      { "Rate Reply Correlator",
        "sna.nlp.thdr.optional.22.raterep",
        FT_UINT8, BASE_DEC, NULL, 0x0f, NULL, HFILL }},

    { &hf_sna_nlp_opti_22_field1,
      { "Field 1", "sna.nlp.thdr.optional.22.field1",
        FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_nlp_opti_22_field2,
      { "Field 2", "sna.nlp.thdr.optional.22.field2",
        FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_nlp_opti_22_field3,
      { "Field 3", "sna.nlp.thdr.optional.22.field3",
        FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_nlp_opti_22_field4,
      { "Field 4", "sna.nlp.thdr.optional.22.field4",
        FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_rh,
      { "Request/Response Header", "sna.rh", FT_NONE, BASE_NONE,
        NULL, 0x0, NULL, HFILL }},

    { &hf_sna_rh_0,
      { "Request/Response Header Byte 0", "sna.rh.0", FT_UINT8,
        BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_rh_1,
      { "Request/Response Header Byte 1", "sna.rh.1", FT_UINT8,
        BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_rh_2,
      { "Request/Response Header Byte 2", "sna.rh.2", FT_UINT8,
        BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_rh_rri,
      { "Request/Response Indicator", "sna.rh.rri", FT_BOOLEAN,
        8, TFS(&tfs_response_request), 0x80, NULL, HFILL }},

    { &hf_sna_rh_ru_category,
      { "Request/Response Unit Category", "sna.rh.ru_category",
        FT_UINT8, BASE_HEX, VALS(sna_rh_ru_category_vals), 0x60,
        NULL, HFILL }},

    { &hf_sna_rh_fi,
      { "Format Indicator", "sna.rh.fi", FT_BOOLEAN, 8,
        TFS(&sna_rh_fi_truth), 0x08, NULL, HFILL }},

    { &hf_sna_rh_sdi,
      { "Sense Data Included", "sna.rh.sdi", FT_BOOLEAN, 8,
        TFS(&tfs_included_not_included), 0x04, NULL, HFILL }},

    { &hf_sna_rh_bci,
      { "Begin Chain Indicator", "sna.rh.bci", FT_BOOLEAN, 8,
        TFS(&sna_rh_bci_truth), 0x02, NULL, HFILL }},

    { &hf_sna_rh_eci,
      { "End Chain Indicator", "sna.rh.eci", FT_BOOLEAN, 8,
        TFS(&sna_rh_eci_truth), 0x01, NULL, HFILL }},

    { &hf_sna_rh_dr1,
      { "Definite Response 1 Indicator", "sna.rh.dr1", FT_BOOLEAN,
        8, NULL, 0x80, NULL, HFILL }},

    { &hf_sna_rh_lcci,
      { "Length-Checked Compression Indicator", "sna.rh.lcci",
        FT_BOOLEAN, 8, TFS(&sna_rh_lcci_truth), 0x40, NULL, HFILL }},

    { &hf_sna_rh_dr2,
      { "Definite Response 2 Indicator", "sna.rh.dr2", FT_BOOLEAN,
        8, NULL, 0x20, NULL, HFILL }},

    { &hf_sna_rh_eri,
      { "Exception Response Indicator", "sna.rh.eri", FT_BOOLEAN,
        8, NULL, 0x10, NULL, HFILL }},

    { &hf_sna_rh_rti,
      { "Response Type Indicator", "sna.rh.rti", FT_BOOLEAN,
        8, TFS(&sna_rh_rti_truth), 0x10, NULL, HFILL }},

    { &hf_sna_rh_rlwi,
      { "Request Larger Window Indicator", "sna.rh.rlwi", FT_BOOLEAN,
        8, NULL, 0x04, NULL, HFILL }},

    { &hf_sna_rh_qri,
      { "Queued Response Indicator", "sna.rh.qri", FT_BOOLEAN,
        8, TFS(&sna_rh_qri_truth), 0x02, NULL, HFILL }},

    { &hf_sna_rh_pi,
      { "Pacing Indicator", "sna.rh.pi", FT_BOOLEAN,
        8, NULL, 0x01, NULL, HFILL }},

    { &hf_sna_rh_bbi,
      { "Begin Bracket Indicator", "sna.rh.bbi", FT_BOOLEAN,
        8, NULL, 0x80, NULL, HFILL }},

    { &hf_sna_rh_ebi,
      { "End Bracket Indicator", "sna.rh.ebi", FT_BOOLEAN,
        8, NULL, 0x40, NULL, HFILL }},

    { &hf_sna_rh_cdi,
      { "Change Direction Indicator", "sna.rh.cdi", FT_BOOLEAN,
        8, NULL, 0x20, NULL, HFILL }},

    { &hf_sna_rh_csi,
      { "Code Selection Indicator", "sna.rh.csi", FT_UINT8, BASE_DEC,
        VALS(sna_rh_csi_vals), 0x08, NULL, HFILL }},

    { &hf_sna_rh_edi,
      { "Enciphered Data Indicator", "sna.rh.edi", FT_BOOLEAN, 8,
        NULL, 0x04, NULL, HFILL }},

    { &hf_sna_rh_pdi,
      { "Padded Data Indicator", "sna.rh.pdi", FT_BOOLEAN, 8, NULL,
        0x02, NULL, HFILL }},

    { &hf_sna_rh_cebi,
      { "Conditional End Bracket Indicator", "sna.rh.cebi",
        FT_BOOLEAN, 8, NULL, 0x01, NULL, HFILL }},

/*    { &hf_sna_ru,
    { "Request/Response Unit", "sna.ru", FT_NONE, BASE_NONE,
    NULL, 0x0, NULL, HFILL }},*/

    { &hf_sna_gds,
      { "GDS Variable", "sna.gds", FT_NONE, BASE_NONE, NULL, 0x0,
        NULL, HFILL }},

    { &hf_sna_gds_len,
      { "GDS Variable Length", "sna.gds.len", FT_UINT16, BASE_DEC,
        NULL, 0x7fff, NULL, HFILL }},

    { &hf_sna_gds_cont,
      { "Continuation Flag", "sna.gds.cont", FT_BOOLEAN, 16, NULL,
        0x8000, NULL, HFILL }},

    { &hf_sna_gds_type,
      { "Type of Variable", "sna.gds.type", FT_UINT16, BASE_HEX,
        VALS(sna_gds_var_vals), 0x0, NULL, HFILL }},

    { &hf_sna_gds_info,
      { "Information", "sna.gds.info", FT_BYTES, BASE_NONE,
        NULL, 0x0, NULL, HFILL }},

#if 0
    { &hf_sna_xid,
      { "XID", "sna.xid", FT_NONE, BASE_NONE, NULL, 0x0,
        "XID Frame", HFILL }},
#endif

    { &hf_sna_xid_0,
      { "XID Byte 0", "sna.xid.0", FT_UINT8, BASE_HEX, NULL, 0x0,
        NULL, HFILL }},

    { &hf_sna_xid_format,
      { "XID Format", "sna.xid.format", FT_UINT8, BASE_DEC, NULL,
        0xf0, NULL, HFILL }},

    { &hf_sna_xid_type,
      { "XID Type", "sna.xid.type", FT_UINT8, BASE_DEC,
        VALS(sna_xid_type_vals), 0x0f, NULL, HFILL }},

    { &hf_sna_xid_len,
      { "XID Length", "sna.xid.len", FT_UINT8, BASE_DEC, NULL, 0x0,
        NULL, HFILL }},

    { &hf_sna_xid_id,
      { "Node Identification", "sna.xid.id", FT_UINT32, BASE_HEX,
        NULL, 0x0, NULL, HFILL }},

    { &hf_sna_xid_idblock,
      { "ID Block", "sna.xid.idblock", FT_UINT32, BASE_HEX, NULL,
        0xfff00000, NULL, HFILL }},

    { &hf_sna_xid_idnum,
      { "ID Number", "sna.xid.idnum", FT_UINT32, BASE_HEX, NULL,
        0x0fffff, NULL, HFILL }},

    { &hf_sna_xid_3_8,
      { "Characteristics of XID sender", "sna.xid.type3.8", FT_UINT16,
        BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_xid_3_init_self,
      { "INIT-SELF support", "sna.xid.type3.initself",
        FT_BOOLEAN, 16, NULL, 0x8000, NULL, HFILL }},

    { &hf_sna_xid_3_stand_bind,
      { "Stand-Alone BIND Support", "sna.xid.type3.stand_bind",
        FT_BOOLEAN, 16, NULL, 0x4000, NULL, HFILL }},

    { &hf_sna_xid_3_gener_bind,
      { "Whole BIND PIU generated indicator",
        "sna.xid.type3.gener_bind", FT_BOOLEAN, 16, NULL, 0x2000,
        NULL, HFILL }},

    { &hf_sna_xid_3_recve_bind,
      { "Whole BIND PIU required indicator",
        "sna.xid.type3.recve_bind", FT_BOOLEAN, 16, NULL, 0x1000,
        NULL, HFILL }},

    { &hf_sna_xid_3_actpu,
      { "ACTPU suppression indicator", "sna.xid.type3.actpu",
        FT_BOOLEAN, 16, NULL, 0x0080, NULL, HFILL }},

    { &hf_sna_xid_3_nwnode,
      { "Sender is network node", "sna.xid.type3.nwnode",
        FT_BOOLEAN, 16, NULL, 0x0040, NULL, HFILL }},

    { &hf_sna_xid_3_cp,
      { "Control Point Services", "sna.xid.type3.cp",
        FT_BOOLEAN, 16, NULL, 0x0020, NULL, HFILL }},

    { &hf_sna_xid_3_cpcp,
      { "CP-CP session support", "sna.xid.type3.cpcp",
        FT_BOOLEAN, 16, NULL, 0x0010, NULL, HFILL }},

    { &hf_sna_xid_3_state,
      { "XID exchange state indicator", "sna.xid.type3.state",
        FT_UINT16, BASE_HEX, VALS(sna_xid_3_state_vals),
        0x000c, NULL, HFILL }},

    { &hf_sna_xid_3_nonact,
      { "Nonactivation Exchange", "sna.xid.type3.nonact",
        FT_BOOLEAN, 16, NULL, 0x0002, NULL, HFILL }},

    { &hf_sna_xid_3_cpchange,
      { "CP name change support", "sna.xid.type3.cpchange",
        FT_BOOLEAN, 16, NULL, 0x0001, NULL, HFILL }},

    { &hf_sna_xid_3_10,
      { "XID Type 3 Byte 10", "sna.xid.type3.10", FT_UINT8, BASE_HEX,
        NULL, 0x0, NULL, HFILL }},

    { &hf_sna_xid_3_asend_bind,
      { "Adaptive BIND pacing support as sender",
        "sna.xid.type3.asend_bind", FT_BOOLEAN, 8, NULL, 0x80,
        NULL, HFILL }},

    { &hf_sna_xid_3_arecv_bind,
      { "Adaptive BIND pacing support as receiver",
        "sna.xid.type3.asend_recv", FT_BOOLEAN, 8, NULL, 0x40,
        NULL, HFILL }},

    { &hf_sna_xid_3_quiesce,
      { "Quiesce TG Request",
        "sna.xid.type3.quiesce", FT_BOOLEAN, 8, NULL, 0x20,
        NULL, HFILL }},

    { &hf_sna_xid_3_pucap,
      { "PU Capabilities",
        "sna.xid.type3.pucap", FT_BOOLEAN, 8, NULL, 0x10,
        NULL, HFILL }},

    { &hf_sna_xid_3_pbn,
      { "Peripheral Border Node",
        "sna.xid.type3.pbn", FT_BOOLEAN, 8, NULL, 0x08,
        NULL, HFILL }},

    { &hf_sna_xid_3_pacing,
      { "Qualifier for adaptive BIND pacing support",
        "sna.xid.type3.pacing", FT_UINT8, BASE_HEX, NULL, 0x03,
        NULL, HFILL }},

    { &hf_sna_xid_3_11,
      { "XID Type 3 Byte 11", "sna.xid.type3.11", FT_UINT8, BASE_HEX,
        NULL, 0x0, NULL, HFILL }},

    { &hf_sna_xid_3_tgshare,
      { "TG Sharing Prohibited Indicator",
        "sna.xid.type3.tgshare", FT_BOOLEAN, 8, NULL, 0x40,
        NULL, HFILL }},

    { &hf_sna_xid_3_dedsvc,
      { "Dedicated SVC Indicator",
        "sna.xid.type3.dedsvc", FT_BOOLEAN, 8, NULL, 0x20,
        NULL, HFILL }},

    { &hf_sna_xid_3_12,
      { "XID Type 3 Byte 12", "sna.xid.type3.12", FT_UINT8, BASE_HEX,
        NULL, 0x0, NULL, HFILL }},

    { &hf_sna_xid_3_negcsup,
      { "Negotiation Complete Supported",
        "sna.xid.type3.negcsup", FT_BOOLEAN, 8, NULL, 0x80,
        NULL, HFILL }},

    { &hf_sna_xid_3_negcomp,
      { "Negotiation Complete",
        "sna.xid.type3.negcomp", FT_BOOLEAN, 8, NULL, 0x40,
        NULL, HFILL }},

    { &hf_sna_xid_3_15,
      { "XID Type 3 Byte 15", "sna.xid.type3.15", FT_UINT8, BASE_HEX,
        NULL, 0x0, NULL, HFILL }},

    { &hf_sna_xid_3_partg,
      { "Parallel TG Support",
        "sna.xid.type3.partg", FT_BOOLEAN, 8, NULL, 0x80,
        NULL, HFILL }},

    { &hf_sna_xid_3_dlur,
      { "Dependent LU Requester Indicator",
        "sna.xid.type3.dlur", FT_BOOLEAN, 8, NULL, 0x40,
        NULL, HFILL }},

    { &hf_sna_xid_3_dlus,
      { "DLUS Served LU Registration Indicator",
        "sna.xid.type3.dlus", FT_BOOLEAN, 8, NULL, 0x20,
        NULL, HFILL }},

    { &hf_sna_xid_3_exbn,
      { "Extended HPR Border Node",
        "sna.xid.type3.exbn", FT_BOOLEAN, 8, NULL, 0x10,
        NULL, HFILL }},

    { &hf_sna_xid_3_genodai,
      { "Generalized ODAI Usage Option",
        "sna.xid.type3.genodai", FT_BOOLEAN, 8, NULL, 0x08,
        NULL, HFILL }},

    { &hf_sna_xid_3_branch,
      { "Branch Indicator", "sna.xid.type3.branch",
        FT_UINT8, BASE_HEX, VALS(sna_xid_3_branch_vals),
        0x06, NULL, HFILL }},

    { &hf_sna_xid_3_brnn,
      { "Option Set 1123 Indicator",
        "sna.xid.type3.brnn", FT_BOOLEAN, 8, NULL, 0x01,
        NULL, HFILL }},

    { &hf_sna_xid_3_tg,
      { "XID TG", "sna.xid.type3.tg", FT_UINT8, BASE_HEX, NULL, 0x0,
        NULL, HFILL }},

    { &hf_sna_xid_3_dlc,
      { "XID DLC", "sna.xid.type3.dlc", FT_UINT8, BASE_HEX, NULL, 0x0,
        NULL, HFILL }},

    { &hf_sna_xid_3_dlen,
      { "DLC Dependent Section Length", "sna.xid.type3.dlen",
        FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_control_len,
      { "Control Vector Length", "sna.control.len",
        FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_control_key,
      { "Control Vector Key", "sna.control.key",
        FT_UINT8, BASE_HEX, VALS(sna_control_vals), 0x0, NULL,
        HFILL }},

    { &hf_sna_control_hprkey,
      { "Control Vector HPR Key", "sna.control.hprkey",
        FT_UINT8, BASE_HEX, VALS(sna_control_hpr_vals), 0x0, NULL,
        HFILL }},

    { &hf_sna_control_05_delay,
      { "Channel Delay", "sna.control.05.delay",
        FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_control_05_type,
      { "Network Address Type", "sna.control.05.type",
        FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL }},

    { &hf_sna_control_05_ptp,
      { "Point-to-point", "sna.control.05.ptp",
        FT_BOOLEAN, 8, NULL, 0x80, NULL, HFILL }},

    { &hf_sna_control_0e_type,
      { "Type", "sna.control.0e.type",
        FT_UINT8, BASE_HEX, VALS(sna_control_0e_type_vals),
        0, NULL, HFILL }},

    { &hf_sna_control_0e_value,
      { "Value", "sna.control.0e.value",
        FT_STRING, BASE_NONE, NULL, 0, NULL, HFILL }},

    { &hf_sna_padding,
      { "Padding", "sna.padding",
        FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }},

    { &hf_sna_reserved,
      { "Reserved", "sna.reserved",
        FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }},

    { &hf_sna_biu_segment_data,
      { "BIU segment data", "sna.biu_segment_data",
        FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }},

  };
  static int *ett[] = {
    &ett_sna,
    &ett_sna_th,
    &ett_sna_th_fid,
    &ett_sna_nlp_nhdr,
    &ett_sna_nlp_nhdr_0,
    &ett_sna_nlp_nhdr_1,
    &ett_sna_nlp_thdr,
    &ett_sna_nlp_thdr_8,
    &ett_sna_nlp_thdr_9,
    &ett_sna_nlp_opti_un,
    &ett_sna_nlp_opti_0d,
    &ett_sna_nlp_opti_0d_4,
    &ett_sna_nlp_opti_0e,
    &ett_sna_nlp_opti_0e_stat,
    &ett_sna_nlp_opti_0e_absp,
    &ett_sna_nlp_opti_0f,
    &ett_sna_nlp_opti_10,
    &ett_sna_nlp_opti_12,
    &ett_sna_nlp_opti_14,
    &ett_sna_nlp_opti_14_si,
    &ett_sna_nlp_opti_14_si_2,
    &ett_sna_nlp_opti_14_rr,
    &ett_sna_nlp_opti_14_rr_2,
    &ett_sna_nlp_opti_22,
    &ett_sna_nlp_opti_22_2,
    &ett_sna_nlp_opti_22_3,
    &ett_sna_rh,
    &ett_sna_rh_0,
    &ett_sna_rh_1,
    &ett_sna_rh_2,
    &ett_sna_gds,
    &ett_sna_xid_0,
    &ett_sna_xid_id,
    &ett_sna_xid_3_8,
    &ett_sna_xid_3_10,
    &ett_sna_xid_3_11,
    &ett_sna_xid_3_12,
    &ett_sna_xid_3_15,
    &ett_sna_control_un,
    &ett_sna_control_05,
    &ett_sna_control_05hpr,
    &ett_sna_control_05hpr_type,
    &ett_sna_control_0e,
  };
  module_t *sna_module;

  proto_sna = proto_register_protocol("Systems Network Architecture", "SNA", "sna");
  proto_register_field_array(proto_sna, hf, array_length(hf));
  proto_register_subtree_array(ett, array_length(ett));
  sna_handle = register_dissector("sna", dissect_sna, proto_sna);

  proto_sna_xid = proto_register_protocol("Systems Network Architecture XID", "SNA XID", "sna_xid");
  sna_xid_handle = register_dissector("sna_xid", dissect_sna_xid, proto_sna_xid);

  sna_address_type = address_type_dissector_register("AT_SNA", "SNA Address", sna_fid_to_str_buf, sna_address_str_len, NULL, NULL, NULL, NULL, NULL);

  /* Register configuration options */
  sna_module = prefs_register_protocol(proto_sna, NULL);
  prefs_register_bool_preference(sna_module, "defragment",
    "Reassemble fragmented BIUs",
    "Whether fragmented BIUs should be reassembled",
    &sna_defragment);

  reassembly_table_register(&sna_reassembly_table,
      &addresses_reassembly_table_functions);
}

void
proto_reg_handoff_sna(void)
{
  dissector_add_uint("llc.dsap", SAP_SNA_PATHCTRL, sna_handle);
  dissector_add_uint("llc.dsap", SAP_SNA1, sna_handle);
  dissector_add_uint("llc.dsap", SAP_SNA2, sna_handle);
  dissector_add_uint("llc.dsap", SAP_SNA3, sna_handle);
  dissector_add_uint("llc.dsap", SAP_SNA4, sna_handle);
  dissector_add_uint("llc.xid_dsap", SAP_SNA_PATHCTRL, sna_xid_handle);
  dissector_add_uint("llc.xid_dsap", SAP_SNA1, sna_xid_handle);
  dissector_add_uint("llc.xid_dsap", SAP_SNA2, sna_xid_handle);
  dissector_add_uint("llc.xid_dsap", SAP_SNA3, sna_xid_handle);
  /* RFC 2043 */
  dissector_add_uint("ppp.protocol", PPP_SNA, sna_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:
 */

Coverage Report

Created: 2025-12-27 06:52