epan/dissectors/packet-ubx.c

   1 /* packet-ubx.c
   2  * u-blox UBX protocol dissection.
   3  *
   4  * By Timo Warns <timo.warns@gmail.com>
   5  * Copyright 2023 Timo Warns
   6  *
   7  * Wireshark - Network traffic analyzer
   8  * By Gerald Combs <gerald@unicom.net>
   9  * Copyright 1998 Gerald Combs
  10  *
  11  * SPDX-License-Identifier: GPL-2.0-or-later
  12  */
  13
  14 #include "config.h"
  15
  16 #include <epan/expert.h>
  17 #include <epan/packet.h>
  18 #include <epan/unit_strings.h>
  19 #include <wsutil/array.h>
  20 #include <wsutil/utf8_entities.h>
  21 #include <wsutil/pint.h>
  22
  23 #include "packet-ubx.h"
  24 #include "packet-sbas_l1.h"
  25
  26 /*
  27  * Dissects the UBX protocol of u-blox GNSS receivers as defined by the
  28  * u-blox 8 / u-blox M8 receiver description.
  29  */
  30
  31 /* mapping from UBX message class / id to mnemonics */
  32 static const value_string UBX_MSG_CLASS_ID[] = {
  33     {UBX_ACK_ACK, "UBX-ACK-ACK"},
  34     {UBX_ACK_NAK, "UBX-ACK-NAK"},
  35     {UBX_AID_ALM, "UBX-AID-ALM"},
  36     {UBX_AID_AOP, "UBX-AID-AOP"},
  37     {UBX_AID_EPH, "UBX-AID-EPH"},
  38     {UBX_AID_HUI, "UBX-AID-HUI"},
  39     {UBX_AID_INI, "UBX-AID-INI"},
  40     {UBX_CFG_ANT, "UBX-CFG-ANT"},
  41     {UBX_CFG_BATCH, "UBX-CFG-BATCH"},
  42     {UBX_CFG_CFG, "UBX-CFG-CFG"},
  43     {UBX_CFG_DAT, "UBX-CFG-DAT"},
  44     {UBX_CFG_DGNSS, "UBX-CFG-DGNSS"},
  45     {UBX_CFG_DOSC, "UBX-CFG-DOSC"},
  46     {UBX_CFG_ESFALG, "UBX-CFG-ESFALG"},
  47     {UBX_CFG_ESFA, "UBX-CFG-ESFA"},
  48     {UBX_CFG_ESFG, "UBX-CFG-ESFG"},
  49     {UBX_CFG_ESFWT, "UBX-CFG-ESFWT"},
  50     {UBX_CFG_ESRC, "UBX-CFG-ESRC"},
  51     {UBX_CFG_GEOFENCE, "UBX-CFG-GEOFENCE"},
  52     {UBX_CFG_GNSS, "UBX-CFG-GNSS"},
  53     {UBX_CFG_HNR, "UBX-CFG-HNR"},
  54     {UBX_CFG_INF, "UBX-CFG-INF"},
  55     {UBX_CFG_ITFM, "UBX-CFG-ITFM"},
  56     {UBX_CFG_LOGFILTER, "UBX-CFG-LOGFILTER"},
  57     {UBX_CFG_MSG, "UBX-CFG-MSG"},
  58     {UBX_CFG_NAV5, "UBX-CFG-NAV5"},
  59     {UBX_CFG_NAVX5, "UBX-CFG-NAVX5"},
  60     {UBX_CFG_NMEA, "UBX-CFG-NMEA"},
  61     {UBX_CFG_ODO, "UBX-CFG-ODO"},
  62     {UBX_CFG_PM2, "UBX-CFG-PM2"},
  63     {UBX_CFG_PMS, "UBX-CFG-PMS"},
  64     {UBX_CFG_PRT, "UBX-CFG-PRT"},
  65     {UBX_CFG_PWR, "UBX-CFG-PWR"},
  66     {UBX_CFG_RATE, "UBX-CFG-RATE"},
  67     {UBX_CFG_RINV, "UBX-CFG-RINV"},
  68     {UBX_CFG_RST, "UBX-CFG-RST"},
  69     {UBX_CFG_RXM, "UBX-CFG-RXM"},
  70     {UBX_CFG_SBAS, "UBX-CFG-SBAS"},
  71     {UBX_CFG_SENIF, "UBX-CFG-SENIF"},
  72     {UBX_CFG_SLAS, "UBX-CFG-SLAS"},
  73     {UBX_CFG_SMGR, "UBX-CFG-SMGR"},
  74     {UBX_CFG_SPT, "UBX-CFG-SPT"},
  75     {UBX_CFG_TMODE2, "UBX-CFG-TMODE2"},
  76     {UBX_CFG_TMODE3, "UBX-CFG-TMODE3"},
  77     {UBX_CFG_TP5, "UBX-CFG-TP5"},
  78     {UBX_CFG_TXSLOT, "UBX-CFG-TXSLOT"},
  79     {UBX_CFG_USB, "UBX-CFG-USB"},
  80     {UBX_ESF_ALG, "UBX-ESF-ALG"},
  81     {UBX_ESF_INS, "UBX-ESF-INS"},
  82     {UBX_ESF_MEAS, "UBX-ESF-MEAS"},
  83     {UBX_ESF_RAW, "UBX-ESF-RAW"},
  84     {UBX_ESF_STATUS, "UBX-ESF-STATUS"},
  85     {UBX_HNR_ATT, "UBX-HNR-ATT"},
  86     {UBX_HNR_INS, "UBX-HNR-INS"},
  87     {UBX_HNR_PVT, "UBX-HNR-PVT"},
  88     {UBX_INF_DEBUG, "UBX-INF-DEBUG"},
  89     {UBX_INF_ERROR, "UBX-INF-ERROR"},
  90     {UBX_INF_NOTICE, "UBX-INF-NOTICE"},
  91     {UBX_INF_TEST, "UBX-INF-TEST"},
  92     {UBX_INF_WARNING, "UBX-INF-WARNING"},
  93     {UBX_LOG_BATCH, "UBX-LOG-BATCH"},
  94     {UBX_LOG_CREATE, "UBX-LOG-CREATE"},
  95     {UBX_LOG_ERASE, "UBX-LOG-ERASE"},
  96     {UBX_LOG_FINDTIME, "UBX-LOG-FINDTIME"},
  97     {UBX_LOG_INFO, "UBX-LOG-INFO"},
  98     {UBX_LOG_RETRIEVEBATCH, "UBX-LOG-RETRIEVEBATCH"},
  99     {UBX_LOG_RETRIEVEPOSEXTRA, "UBX-LOG-RETRIEVEPOSEXTRA"},
 100     {UBX_LOG_RETRIEVEPOS, "UBX-LOG-RETRIEVEPOS"},
 101     {UBX_LOG_RETRIEVESTRING, "UBX-LOG-RETRIEVESTRING"},
 102     {UBX_LOG_RETRIEVE, "UBX-LOG-RETRIEVE"},
 103     {UBX_LOG_STRING, "UBX-LOG-STRING"},
 104     {UBX_MGA_ACK_DATA0, "UBX-MGA-ACK-DATA0"},
 105     {UBX_MGA_ANO, "UBX-MGA-ANO"},
 106     {UBX_MGA_BDS, "UBX-MGA-BDS"},
 107     {UBX_MGA_DBD, "UBX-MGA-DBD"},
 108     {UBX_MGA_FLASH, "UBX-MGA-FLASH"},
 109     {UBX_MGA_GAL, "UBX-MGA-GAL"},
 110     {UBX_MGA_GLO, "UBX-MGA-GLO"},
 111     {UBX_MGA_GPS, "UBX-MGA-GPS"},
 112     {UBX_MGA_INI, "UBX-MGA-INI"},
 113     {UBX_MGA_QZSS, "UBX-MGA-QZSS"},
 114     {UBX_MON_BATCH, "UBX-MON-BATCH"},
 115     {UBX_MON_GNSS, "UBX-MON-GNSS"},
 116     {UBX_MON_HW2, "UBX-MON-HW2"},
 117     {UBX_MON_HW, "UBX-MON-HW"},
 118     {UBX_MON_IO, "UBX-MON-IO"},
 119     {UBX_MON_MSGPP, "UBX-MON-MSGPP"},
 120     {UBX_MON_PATCH, "UBX-MON-PATCH"},
 121     {UBX_MON_RXBUF, "UBX-MON-RXBUF"},
 122     {UBX_MON_RXR, "UBX-MON-RXR"},
 123     {UBX_MON_SMGR, "UBX-MON-SMGR"},
 124     {UBX_MON_SPT, "UBX-MON-SPT"},
 125     {UBX_MON_TXBUF, "UBX-MON-TXBUF"},
 126     {UBX_MON_VER, "UBX-MON-VER"},
 127     {UBX_NAV_AOPSTATUS, "UBX-NAV-AOPSTATUS"},
 128     {UBX_NAV_ATT, "UBX-NAV-ATT"},
 129     {UBX_NAV_CLOCK, "UBX-NAV-CLOCK"},
 130     {UBX_NAV_COV, "UBX-NAV-COV"},
 131     {UBX_NAV_DGPS, "UBX-NAV-DGPS"},
 132     {UBX_NAV_DOP, "UBX-NAV-DOP"},
 133     {UBX_NAV_EELL, "UBX-NAV-EELL"},
 134     {UBX_NAV_EOE, "UBX-NAV-EOE"},
 135     {UBX_NAV_GEOFENCE, "UBX-NAV-GEOFENCE"},
 136     {UBX_NAV_HPPOSECEF, "UBX-NAV-HPPOSECEF"},
 137     {UBX_NAV_HPPOSLLH, "UBX-NAV-HPPOSLLH"},
 138     {UBX_NAV_NMI, "UBX-NAV-NMI"},
 139     {UBX_NAV_ODO, "UBX-NAV-ODO"},
 140     {UBX_NAV_ORB, "UBX-NAV-ORB"},
 141     {UBX_NAV_POSECEF, "UBX-NAV-POSECEF"},
 142     {UBX_NAV_POSLLH, "UBX-NAV-POSLLH"},
 143     {UBX_NAV_PVT, "UBX-NAV-PVT"},
 144     {UBX_NAV_RELPOSNED, "UBX-NAV-RELPOSNED"},
 145     {UBX_NAV_RESETODO, "UBX-NAV-RESETODO"},
 146     {UBX_NAV_SAT, "UBX-NAV-SAT"},
 147     {UBX_NAV_SBAS, "UBX-NAV-SBAS"},
 148     {UBX_NAV_SLAS, "UBX-NAV-SLAS"},
 149     {UBX_NAV_SOL, "UBX-NAV-SOL"},
 150     {UBX_NAV_STATUS, "UBX-NAV-STATUS"},
 151     {UBX_NAV_SVINFO, "UBX-NAV-SVINFO"},
 152     {UBX_NAV_SVIN, "UBX-NAV-SVIN"},
 153     {UBX_NAV_TIMEBDS, "UBX-NAV-TIMEBDS"},
 154     {UBX_NAV_TIMEGAL, "UBX-NAV-TIMEGAL"},
 155     {UBX_NAV_TIMEGLO, "UBX-NAV-TIMEGLO"},
 156     {UBX_NAV_TIMEGPS, "UBX-NAV-TIMEGPS"},
 157     {UBX_NAV_TIMELS, "UBX-NAV-TIMELS"},
 158     {UBX_NAV_TIMEUTC, "UBX-NAV-TIMEUTC"},
 159     {UBX_NAV_VELECEF, "UBX-NAV-VELECEF"},
 160     {UBX_NAV_VELNED, "UBX-NAV-VELNED"},
 161     {UBX_RXM_IMES, "UBX-RXM-IMES"},
 162     {UBX_RXM_MEASX, "UBX-RXM-MEASX"},
 163     {UBX_RXM_PMREQ, "UBX-RXM-PMREQ"},
 164     {UBX_RXM_RAWX, "UBX-RXM-RAWX"},
 165     {UBX_RXM_RLM, "UBX-RXM-RLM"},
 166     {UBX_RXM_RTCM, "UBX-RXM-RTCM"},
 167     {UBX_RXM_SFRBX, "UBX-RXM-SFRBX"},
 168     {UBX_RXM_SVSI, "UBX-RXM-SVSI"},
 169     {UBX_SEC_UNIQID, "UBX-SEC-UNIQID"},
 170     {UBX_TIM_DOSC, "UBX-TIM-DOSC"},
 171     {UBX_TIM_FCHG, "UBX-TIM-FCHG"},
 172     {UBX_TIM_HOC, "UBX-TIM-HOC"},
 173     {UBX_TIM_SMEAS, "UBX-TIM-SMEAS"},
 174     {UBX_TIM_SVIN, "UBX-TIM-SVIN"},
 175     {UBX_TIM_TM2, "UBX-TIM-TM2"},
 176     {UBX_TIM_TOS, "UBX-TIM-TOS"},
 177     {UBX_TIM_TP, "UBX-TIM-TP"},
 178     {UBX_TIM_VCOCAL, "UBX-TIM-VCOCAL"},
 179     {UBX_TIM_VRFY, "UBX-TIM-VRFY"},
 180     {UBX_UPD_SOS, "UBX-UPD-SOS"},
 181     {0, NULL},
 182 };
 183
 184 static const value_string UBX_GNSS_ID[] = {
 185     {GNSS_ID_GPS,     "GPS"},
 186     {GNSS_ID_SBAS,    "SBAS"},
 187     {GNSS_ID_GALILEO, "Galileo"},
 188     {GNSS_ID_BEIDOU,  "Beidou"},
 189     {GNSS_ID_IMES,    "IMES"},
 190     {GNSS_ID_QZSS,    "QZSS"},
 191     {GNSS_ID_GLONASS, "Glonass"},
 192     {0, NULL},
 193 };
 194
 195 /* mapping from correction age id to description */
 196 static const value_string UBX_LAST_CORRECTION_AGE[] = {
 197     {0, "not available"},
 198     {1, "age between 0 and 1 second"},
 199     {2, "age between 1 (inclusive) and 2 seconds"},
 200     {3, "age between 2 (inclusive) and 5 seconds"},
 201     {4, "age between 5 (inclusive) and 10 seconds"},
 202     {5, "age between 10 (inclusive) and 15 seconds"},
 203     {6, "age between 15 (inclusive) and 20 seconds"},
 204     {7, "age between 20 (inclusive) and 30 seconds"},
 205     {8, "age between 30 (inclusive) and 45 seconds"},
 206     {9, "age between 45 (inclusive) and 60 seconds"},
 207     {10, "age between 60 (inclusive) and 90 seconds"},
 208     {11, "age between 90 (inclusive) and 120 seconds"},
 209     {12, "age greater or equal than 120 seconds"},
 210     {13, "age greater or equal than 120 seconds"},
 211     {14, "age greater or equal than 120 seconds"},
 212     {15, "age greater or equal than 120 seconds"},
 213     {0, NULL}
 214 };
 215
 216 /* mapping from GNSS fix type id to description */
 217 static const value_string UBX_GNSS_FIX_TYPE[] = {
 218     {0, "no fix"},
 219     {1, "dead reckoning only"},
 220     {2, "2D-fix"},
 221     {3, "3D-fix"},
 222     {4, "GNSS + dead reckoning combined"},
 223     {5, "time only fix"},
 224     {0, NULL}
 225 };
 226
 227 /* signal quality indicator description */
 228 static const value_string UBX_SIGNAL_QUALITY_INDICATOR[] = {
 229     {0, "no signal"},
 230     {1, "searching signal"},
 231     {2, "signal acquired"},
 232     {3, "signal detected but unusable"},
 233     {4, "code locked and time synchronized"},
 234     {5, "code and carrier locked and time synchronized"},
 235     {6, "code and carrier locked and time synchronized"},
 236     {7, "code and carrier locked and time synchronized"},
 237     {0, NULL}
 238 };
 239
 240 /* signal health description */
 241 static const value_string UBX_SIGNAL_HEALTH[] = {
 242     {0, "unknown"},
 243     {1, "healthy"},
 244     {2, "unhealthy"},
 245     {0, NULL}
 246 };
 247
 248 /* orbit source description */
 249 static const value_string UBX_ORBIT_SOURCE[] = {
 250     {0, "no orbit information available"},
 251     {1, "ephemeris is used"},
 252     {2, "almanac is used"},
 253     {3, "AssistNow Offline orbit is used"},
 254     {4, "AssistNow Autonomous orbit is used"},
 255     {5, "other orbit information is used"},
 256     {6, "other orbit information is used"},
 257     {7, "other orbit information is used"},
 258     {0, NULL}
 259 };
 260
 261 /* CFG-GNSS GPS sigCfgMsk */
 262 static const value_string UBX_CFG_GNSS_GPS_SIGCFGMASK[] = {
 263     {0x01, "GPS L1C/A"},
 264     {0x10, "GPS L2C"},
 265     {0, NULL}
 266 };
 267
 268 /* CFG-GNSS SBAS sigCfgMsk */
 269 static const value_string UBX_CFG_GNSS_SBAS_SIGCFGMASK[] = {
 270     {0x01, "SBAS L1C/A"},
 271     {0, NULL}
 272 };
 273
 274 /* CFG-GNSS Galileo sigCfgMsk */
 275 static const value_string UBX_CFG_GNSS_GAL_SIGCFGMASK[] = {
 276     {0x01, "Galileo E1"},
 277     {0x20, "Galileo E5b"},
 278     {0, NULL}
 279 };
 280
 281 /* CFG-GNSS BeiDou sigCfgMsk */
 282 static const value_string UBX_CFG_GNSS_BDS_SIGCFGMASK[] = {
 283     {0x01, "BeiDou B1I"},
 284     {0x10, "BeiDou B2I"},
 285     {0, NULL}
 286 };
 287
 288 /* CFG-GNSS IMES sigCfgMsk */
 289 static const value_string UBX_CFG_GNSS_IMES_SIGCFGMASK[] = {
 290     {0x01, "IMES L1"},
 291     {0, NULL}
 292 };
 293
 294 /* CFG-GNSS QZSS sigCfgMsk */
 295 static const value_string UBX_CFG_GNSS_QZSS_SIGCFGMASK[] = {
 296     {0x01, "QZSS L1C/A"},
 297     {0x04, "QZSS L1S"},
 298     {0x10, "QZSS L2C"},
 299     {0, NULL}
 300 };
 301
 302 /* CFG-GNSS Glonass sigCfgMsk */
 303 static const value_string UBX_CFG_GNSS_GLO_SIGCFGMASK[] = {
 304     {0x01, "Glonass L1"},
 305     {0x10, "Glonass L2"},
 306     {0, NULL}
 307 };
 308
 309 /* UBX-RXM-MEASX Multipath index */
 310 static const value_string UBX_RXM_MEASX_MULTIPATH_INDEX[] = {
 311     {0x0, "not measured"},
 312     {0x1, "low"},
 313     {0x2, "medium"},
 314     {0x3, "high"},
 315     {0, NULL}
 316 };
 317
 318 /* SBAS mode */
 319 static const value_string UBX_SBAS_MODE[] = {
 320     {0, "Disabled"},
 321     {1, "Enabled integrity"},
 322     {3, "Enabled test mode"},
 323     {0, NULL}
 324 };
 325
 326 /* SBAS system */
 327 static const value_string UBX_SBAS_SYSTEM[] = {
 328     {-1, "Unknown"},
 329     {0, "WAAS"},
 330     {1, "EGNOS"},
 331     {2, "MSAS"},
 332     {3, "GAGAN"},
 333     {16, "GPS"},
 334     {0, NULL}
 335 };
 336
 337 /* SBAS testbed description */
 338 static const value_string UBX_SBAS_TESTBED[] = {
 339     {0, "Ignore data when in test mode (SBAS msg 0)"},
 340     {1, "Use data anyhow"},
 341     {0, NULL}
 342 };
 343
 344 /* UTC standard identifier */
 345 static const value_string UBX_UTC_STD_ID[] = {
 346     {0, "Information not available"},
 347     {1, "Communications Research Laboratory (CRL), Tokyo, Japan"},
 348     {2, "National Institute of Standards and Technology (NIST)"},
 349     {3, "U.S. Naval Observatory (USNO)"},
 350     {4, "International Bureau of Weights and Measures (BIPM)"},
 351     {5, "European laboratories"},
 352     {6, "Former Soviet Union (SU)"},
 353     {7, "National Time Service Center (NTSC), China"},
 354     {15, "Unknown"},
 355     {0, NULL}
 356 };
 357
 358 /* Initialize the protocol and registered fields */
 359 static int proto_ubx;
 360
 361 static int hf_ubx_preamble;
 362 static int hf_ubx_msg_class_id;
 363 static int hf_ubx_payload_len;
 364 static int hf_ubx_chksum;
 365
 366 static int hf_ubx_ack_ack;
 367 static int hf_ubx_ack_ack_msg_class_id;
 368
 369 static int hf_ubx_ack_nak;
 370 static int hf_ubx_ack_nak_msg_class_id;
 371
 372 static int hf_ubx_cfg_gnss;
 373 static int hf_ubx_cfg_gnss_version;
 374 static int hf_ubx_cfg_gnss_numtrkchhw;
 375 static int hf_ubx_cfg_gnss_numtrkchuse;
 376 static int hf_ubx_cfg_gnss_numconfigblocks;
 377 static int hf_ubx_cfg_gnss_blk_gnssid;
 378 static int hf_ubx_cfg_gnss_blk_restrkch;
 379 static int hf_ubx_cfg_gnss_blk_maxtrkch;
 380 static int hf_ubx_cfg_gnss_blk_reserved1;
 381 static int hf_ubx_cfg_gnss_blk_enable;
 382 static int hf_ubx_cfg_gnss_blk_sigcfgmask;
 383 static int hf_ubx_cfg_gnss_blk_gps_sigcfgmask;
 384 static int hf_ubx_cfg_gnss_blk_sbas_sigcfgmask;
 385 static int hf_ubx_cfg_gnss_blk_gal_sigcfgmask;
 386 static int hf_ubx_cfg_gnss_blk_bds_sigcfgmask;
 387 static int hf_ubx_cfg_gnss_blk_imes_sigcfgmask;
 388 static int hf_ubx_cfg_gnss_blk_qzss_sigcfgmask;
 389 static int hf_ubx_cfg_gnss_blk_glo_sigcfgmask;
 390
 391 static int hf_ubx_cfg_sbas;
 392 static int hf_ubx_cfg_sbas_mode;
 393 static int hf_ubx_cfg_sbas_mode_enabled;
 394 static int hf_ubx_cfg_sbas_mode_test;
 395 static int hf_ubx_cfg_sbas_usage_range;
 396 static int hf_ubx_cfg_sbas_usage_diffcorr;
 397 static int hf_ubx_cfg_sbas_usage_integrity;
 398 static int hf_ubx_cfg_sbas_max_sbas;
 399 static int hf_ubx_cfg_sbas_scanmode_prn158;
 400 static int hf_ubx_cfg_sbas_scanmode_prn157;
 401 static int hf_ubx_cfg_sbas_scanmode_prn156;
 402 static int hf_ubx_cfg_sbas_scanmode_prn155;
 403 static int hf_ubx_cfg_sbas_scanmode_prn154;
 404 static int hf_ubx_cfg_sbas_scanmode_prn153;
 405 static int hf_ubx_cfg_sbas_scanmode_prn152;
 406 static int hf_ubx_cfg_sbas_scanmode_prn151;
 407 static int hf_ubx_cfg_sbas_scanmode_prn150;
 408 static int hf_ubx_cfg_sbas_scanmode_prn149;
 409 static int hf_ubx_cfg_sbas_scanmode_prn148;
 410 static int hf_ubx_cfg_sbas_scanmode_prn147;
 411 static int hf_ubx_cfg_sbas_scanmode_prn146;
 412 static int hf_ubx_cfg_sbas_scanmode_prn145;
 413 static int hf_ubx_cfg_sbas_scanmode_prn144;
 414 static int hf_ubx_cfg_sbas_scanmode_prn143;
 415 static int hf_ubx_cfg_sbas_scanmode_prn142;
 416 static int hf_ubx_cfg_sbas_scanmode_prn141;
 417 static int hf_ubx_cfg_sbas_scanmode_prn140;
 418 static int hf_ubx_cfg_sbas_scanmode_prn139;
 419 static int hf_ubx_cfg_sbas_scanmode_prn138;
 420 static int hf_ubx_cfg_sbas_scanmode_prn137;
 421 static int hf_ubx_cfg_sbas_scanmode_prn136;
 422 static int hf_ubx_cfg_sbas_scanmode_prn135;
 423 static int hf_ubx_cfg_sbas_scanmode_prn134;
 424 static int hf_ubx_cfg_sbas_scanmode_prn133;
 425 static int hf_ubx_cfg_sbas_scanmode_prn132;
 426 static int hf_ubx_cfg_sbas_scanmode_prn131;
 427 static int hf_ubx_cfg_sbas_scanmode_prn130;
 428 static int hf_ubx_cfg_sbas_scanmode_prn129;
 429 static int hf_ubx_cfg_sbas_scanmode_prn128;
 430 static int hf_ubx_cfg_sbas_scanmode_prn127;
 431 static int hf_ubx_cfg_sbas_scanmode_prn126;
 432 static int hf_ubx_cfg_sbas_scanmode_prn125;
 433 static int hf_ubx_cfg_sbas_scanmode_prn124;
 434 static int hf_ubx_cfg_sbas_scanmode_prn123;
 435 static int hf_ubx_cfg_sbas_scanmode_prn122;
 436 static int hf_ubx_cfg_sbas_scanmode_prn121;
 437 static int hf_ubx_cfg_sbas_scanmode_prn120;
 438
 439 static int * const ubx_cfg_sbas_mode_fields[] = {
 440     &hf_ubx_cfg_sbas_mode_enabled,
 441     &hf_ubx_cfg_sbas_mode_test,
 442     NULL
 443 };
 444
 445 static int hf_ubx_nav_dop;
 446 static int hf_ubx_nav_dop_itow;
 447 static int hf_ubx_nav_dop_gdop;
 448 static int hf_ubx_nav_dop_pdop;
 449 static int hf_ubx_nav_dop_tdop;
 450 static int hf_ubx_nav_dop_vdop;
 451 static int hf_ubx_nav_dop_hdop;
 452 static int hf_ubx_nav_dop_ndop;
 453 static int hf_ubx_nav_dop_edop;
 454
 455 static int hf_ubx_nav_eoe;
 456 static int hf_ubx_nav_eoe_itow;
 457
 458 static int hf_ubx_nav_odo;
 459 static int hf_ubx_nav_odo_version;
 460 static int hf_ubx_nav_odo_reserved1;
 461 static int hf_ubx_nav_odo_itow;
 462 static int hf_ubx_nav_odo_distance;
 463 static int hf_ubx_nav_odo_totaldistance;
 464 static int hf_ubx_nav_odo_distancestd;
 465
 466 static int hf_ubx_nav_posecef;
 467 static int hf_ubx_nav_posecef_itow;
 468 static int hf_ubx_nav_posecef_ecefx;
 469 static int hf_ubx_nav_posecef_ecefy;
 470 static int hf_ubx_nav_posecef_ecefz;
 471 static int hf_ubx_nav_posecef_pacc;
 472
 473 static int hf_ubx_nav_pvt;
 474 static int hf_ubx_nav_pvt_itow;
 475 static int hf_ubx_nav_pvt_year;
 476 static int hf_ubx_nav_pvt_month;
 477 static int hf_ubx_nav_pvt_day;
 478 static int hf_ubx_nav_pvt_hour;
 479 static int hf_ubx_nav_pvt_min;
 480 static int hf_ubx_nav_pvt_sec;
 481 static int hf_ubx_nav_pvt_valid;
 482 static int hf_ubx_nav_pvt_validmag;
 483 static int hf_ubx_nav_pvt_fullyresolved;
 484 static int hf_ubx_nav_pvt_validtime;
 485 static int hf_ubx_nav_pvt_validdate;
 486 static int hf_ubx_nav_pvt_tacc;
 487 static int hf_ubx_nav_pvt_nano;
 488 static int hf_ubx_nav_pvt_fixtype;
 489 static int hf_ubx_nav_pvt_flags;
 490 static int hf_ubx_nav_pvt_headvehvalid;
 491 static int hf_ubx_nav_pvt_psmstate;
 492 static int hf_ubx_nav_pvt_diffsoln;
 493 static int hf_ubx_nav_pvt_gnssfixok;
 494 static int hf_ubx_nav_pvt_flags2;
 495 static int hf_ubx_nav_pvt_confirmedtime;
 496 static int hf_ubx_nav_pvt_confirmeddate;
 497 static int hf_ubx_nav_pvt_confirmedavai;
 498 static int hf_ubx_nav_pvt_numsv;
 499 static int hf_ubx_nav_pvt_lon;
 500 static int hf_ubx_nav_pvt_lat;
 501 static int hf_ubx_nav_pvt_height;
 502 static int hf_ubx_nav_pvt_hmsl;
 503 static int hf_ubx_nav_pvt_hacc;
 504 static int hf_ubx_nav_pvt_vacc;
 505 static int hf_ubx_nav_pvt_veln;
 506 static int hf_ubx_nav_pvt_vele;
 507 static int hf_ubx_nav_pvt_veld;
 508 static int hf_ubx_nav_pvt_gspeed;
 509 static int hf_ubx_nav_pvt_headmot;
 510 static int hf_ubx_nav_pvt_sacc;
 511 static int hf_ubx_nav_pvt_headacc;
 512 static int hf_ubx_nav_pvt_pdop;
 513 static int hf_ubx_nav_pvt_lastcorrectionage;
 514 static int hf_ubx_nav_pvt_invalidllh;
 515 static int hf_ubx_nav_pvt_reserved1;
 516 static int hf_ubx_nav_pvt_headveh;
 517 static int hf_ubx_nav_pvt_magdec;
 518 static int hf_ubx_nav_pvt_magacc;
 519
 520 static int * const ubx_nav_pvt_valid_fields[] = {
 521     &hf_ubx_nav_pvt_validdate,
 522     &hf_ubx_nav_pvt_validtime,
 523     &hf_ubx_nav_pvt_fullyresolved,
 524     &hf_ubx_nav_pvt_validmag,
 525     NULL
 526 };
 527
 528 static int * const ubx_nav_pvt_flags_fields[] = {
 529     &hf_ubx_nav_pvt_gnssfixok,
 530     &hf_ubx_nav_pvt_diffsoln,
 531     &hf_ubx_nav_pvt_psmstate,
 532     &hf_ubx_nav_pvt_headvehvalid,
 533     NULL
 534 };
 535
 536 static int * const ubx_nav_pvt_flags2_fields[] = {
 537     &hf_ubx_nav_pvt_confirmedavai,
 538     &hf_ubx_nav_pvt_confirmeddate,
 539     &hf_ubx_nav_pvt_confirmedtime,
 540     NULL
 541 };
 542
 543 static int hf_ubx_nav_sat;
 544 static int hf_ubx_nav_sat_itow;
 545 static int hf_ubx_nav_sat_version;
 546 static int hf_ubx_nav_sat_num_svs;
 547 static int hf_ubx_nav_sat_reserved1;
 548 static int hf_ubx_nav_sat_gnss_id;
 549 static int hf_ubx_nav_sat_sv_id;
 550 static int hf_ubx_nav_sat_cn0;
 551 static int hf_ubx_nav_sat_elev;
 552 static int hf_ubx_nav_sat_azim;
 553 static int hf_ubx_nav_sat_pr_res;
 554 static int hf_ubx_nav_sat_flags;
 555 static int hf_ubx_nav_sat_quality_ind;
 556 static int hf_ubx_nav_sat_sv_used;
 557 static int hf_ubx_nav_sat_health;
 558 static int hf_ubx_nav_sat_diff_corr;
 559 static int hf_ubx_nav_sat_smoothed;
 560 static int hf_ubx_nav_sat_orbit_src;
 561 static int hf_ubx_nav_sat_eph_avail;
 562 static int hf_ubx_nav_sat_alm_avail;
 563 static int hf_ubx_nav_sat_ano_avail;
 564 static int hf_ubx_nav_sat_aop_avail;
 565 static int hf_ubx_nav_sat_sbas_corr_used;
 566 static int hf_ubx_nav_sat_rtcm_corr_used;
 567 static int hf_ubx_nav_sat_slas_corr_used;
 568 static int hf_ubx_nav_sat_spartn_corr_used;
 569 static int hf_ubx_nav_sat_pr_corr_used;
 570 static int hf_ubx_nav_sat_cr_corr_used;
 571 static int hf_ubx_nav_sat_do_corr_used;
 572
 573 static int * const ubx_nav_sat_flags_fields[] = {
 574     &hf_ubx_nav_sat_quality_ind,
 575     &hf_ubx_nav_sat_sv_used,
 576     &hf_ubx_nav_sat_health,
 577     &hf_ubx_nav_sat_diff_corr,
 578     &hf_ubx_nav_sat_smoothed,
 579     &hf_ubx_nav_sat_orbit_src,
 580     &hf_ubx_nav_sat_eph_avail,
 581     &hf_ubx_nav_sat_alm_avail,
 582     &hf_ubx_nav_sat_ano_avail,
 583     &hf_ubx_nav_sat_aop_avail,
 584     &hf_ubx_nav_sat_sbas_corr_used,
 585     &hf_ubx_nav_sat_rtcm_corr_used,
 586     &hf_ubx_nav_sat_slas_corr_used,
 587     &hf_ubx_nav_sat_spartn_corr_used,
 588     &hf_ubx_nav_sat_pr_corr_used,
 589     &hf_ubx_nav_sat_cr_corr_used,
 590     &hf_ubx_nav_sat_do_corr_used,
 591     NULL
 592 };
 593
 594 static int hf_ubx_nav_sbas;
 595 static int hf_ubx_nav_sbas_itow;
 596 static int hf_ubx_nav_sbas_geo;
 597 static int hf_ubx_nav_sbas_mode;
 598 static int hf_ubx_nav_sbas_sys;
 599 static int hf_ubx_nav_sbas_service;
 600 static int hf_ubx_nav_sbas_service_ranging;
 601 static int hf_ubx_nav_sbas_service_corrections;
 602 static int hf_ubx_nav_sbas_service_integrity;
 603 static int hf_ubx_nav_sbas_service_testmode;
 604 static int hf_ubx_nav_sbas_service_bad;
 605 static int hf_ubx_nav_sbas_cnt;
 606 static int hf_ubx_nav_sbas_reserved1;
 607 static int hf_ubx_nav_sbas_sv_id;
 608 static int hf_ubx_nav_sbas_flags;
 609 static int hf_ubx_nav_sbas_udre;
 610 static int hf_ubx_nav_sbas_sv_sys;
 611 static int hf_ubx_nav_sbas_sv_service;
 612 static int hf_ubx_nav_sbas_reserved2;
 613 static int hf_ubx_nav_sbas_prc;
 614 static int hf_ubx_nav_sbas_reserved3;
 615 static int hf_ubx_nav_sbas_ic;
 616
 617 static int * const ubx_nav_sbas_service_fields[] = {
 618     &hf_ubx_nav_sbas_service_ranging,
 619     &hf_ubx_nav_sbas_service_corrections,
 620     &hf_ubx_nav_sbas_service_integrity,
 621     &hf_ubx_nav_sbas_service_testmode,
 622     &hf_ubx_nav_sbas_service_bad,
 623     NULL
 624 };
 625
 626 static int hf_ubx_nav_timegps;
 627 static int hf_ubx_nav_timegps_itow;
 628 static int hf_ubx_nav_timegps_ftow;
 629 static int hf_ubx_nav_timegps_week;
 630 static int hf_ubx_nav_timegps_leaps;
 631 static int hf_ubx_nav_timegps_valid;
 632 static int hf_ubx_nav_timegps_leapsvalid;
 633 static int hf_ubx_nav_timegps_weekvalid;
 634 static int hf_ubx_nav_timegps_towvalid;
 635 static int hf_ubx_nav_timegps_tacc;
 636
 637 static int * const ubx_nav_timegps_valid_fields[] = {
 638     &hf_ubx_nav_timegps_towvalid,
 639     &hf_ubx_nav_timegps_weekvalid,
 640     &hf_ubx_nav_timegps_leapsvalid,
 641     NULL
 642 };
 643
 644 static int hf_ubx_nav_timeutc;
 645 static int hf_ubx_nav_timeutc_itow;
 646 static int hf_ubx_nav_timeutc_tacc;
 647 static int hf_ubx_nav_timeutc_nano;
 648 static int hf_ubx_nav_timeutc_year;
 649 static int hf_ubx_nav_timeutc_month;
 650 static int hf_ubx_nav_timeutc_day;
 651 static int hf_ubx_nav_timeutc_hour;
 652 static int hf_ubx_nav_timeutc_min;
 653 static int hf_ubx_nav_timeutc_sec;
 654 static int hf_ubx_nav_timeutc_valid;
 655 static int hf_ubx_nav_timeutc_validtow;
 656 static int hf_ubx_nav_timeutc_validwkn;
 657 static int hf_ubx_nav_timeutc_validutc;
 658 static int hf_ubx_nav_timeutc_utcstandard;
 659
 660 static int * const ubx_nav_timeutc_valid_fields[] = {
 661     &hf_ubx_nav_timeutc_validtow,
 662     &hf_ubx_nav_timeutc_validwkn,
 663     &hf_ubx_nav_timeutc_validutc,
 664     &hf_ubx_nav_timeutc_utcstandard,
 665     NULL
 666 };
 667
 668 static int hf_ubx_nav_velecef;
 669 static int hf_ubx_nav_velecef_itow;
 670 static int hf_ubx_nav_velecef_ecefvx;
 671 static int hf_ubx_nav_velecef_ecefvy;
 672 static int hf_ubx_nav_velecef_ecefvz;
 673 static int hf_ubx_nav_velecef_sacc;
 674
 675 static int hf_ubx_rxm_measx;
 676 static int hf_ubx_rxm_measx_version;
 677 static int hf_ubx_rxm_measx_reserved1;
 678 static int hf_ubx_rxm_measx_gpstow;
 679 static int hf_ubx_rxm_measx_glotow;
 680 static int hf_ubx_rxm_measx_bdstow;
 681 static int hf_ubx_rxm_measx_reserved2;
 682 static int hf_ubx_rxm_measx_qzsstow;
 683 static int hf_ubx_rxm_measx_gpstowacc;
 684 static int hf_ubx_rxm_measx_glotowacc;
 685 static int hf_ubx_rxm_measx_bdstowacc;
 686 static int hf_ubx_rxm_measx_reserved3;
 687 static int hf_ubx_rxm_measx_qzsstowacc;
 688 static int hf_ubx_rxm_measx_numsv;
 689 static int hf_ubx_rxm_measx_flags_towset;
 690 static int hf_ubx_rxm_measx_reserved4;
 691 static int hf_ubx_rxm_measx_gnssid;
 692 static int hf_ubx_rxm_measx_svid;
 693 static int hf_ubx_rxm_measx_cn0;
 694 static int hf_ubx_rxm_measx_mpathindic;
 695 static int hf_ubx_rxm_measx_dopplerms;
 696 static int hf_ubx_rxm_measx_dopplerhz;
 697 static int hf_ubx_rxm_measx_wholechips;
 698 static int hf_ubx_rxm_measx_fracchips;
 699 static int hf_ubx_rxm_measx_codephase;
 700 static int hf_ubx_rxm_measx_intcodephase;
 701 static int hf_ubx_rxm_measx_pseurangermserr;
 702 static int hf_ubx_rxm_measx_reserved5;
 703
 704 static int hf_ubx_rxm_rawx;
 705 static int hf_ubx_rxm_rawx_rcvtow;
 706 static int hf_ubx_rxm_rawx_week;
 707 static int hf_ubx_rxm_rawx_leaps;
 708 static int hf_ubx_rxm_rawx_nummeas;
 709 static int hf_ubx_rxm_rawx_recstat;
 710 static int hf_ubx_rxm_rawx_recstat_leapsec;
 711 static int hf_ubx_rxm_rawx_recstat_clkreset;
 712 static int hf_ubx_rxm_rawx_version;
 713 static int hf_ubx_rxm_rawx_reserved1;
 714 static int hf_ubx_rxm_rawx_prmes;
 715 static int hf_ubx_rxm_rawx_cpmes;
 716 static int hf_ubx_rxm_rawx_domes;
 717 static int hf_ubx_rxm_rawx_gnssid;
 718 static int hf_ubx_rxm_rawx_svid;
 719 static int hf_ubx_rxm_rawx_sigid;
 720 static int hf_ubx_rxm_rawx_freqid;
 721 static int hf_ubx_rxm_rawx_locktime;
 722 static int hf_ubx_rxm_rawx_cn0;
 723 static int hf_ubx_rxm_rawx_prstdev;
 724 static int hf_ubx_rxm_rawx_cpstdev;
 725 static int hf_ubx_rxm_rawx_dostdev;
 726 static int hf_ubx_rxm_rawx_trkstat;
 727 static int hf_ubx_rxm_rawx_trkstat_prvalid;
 728 static int hf_ubx_rxm_rawx_trkstat_cpvalid;
 729 static int hf_ubx_rxm_rawx_trkstat_halfcyc;
 730 static int hf_ubx_rxm_rawx_trkstat_subhalfcyc;
 731 static int hf_ubx_rxm_rawx_reserved2;
 732
 733 static int * const ubx_rxm_rawx_recstat_fields[] = {
 734     &hf_ubx_rxm_rawx_recstat_leapsec,
 735     &hf_ubx_rxm_rawx_recstat_clkreset,
 736     NULL
 737 };
 738
 739 static int * const ubx_rxm_rawx_trkstat_fields[] = {
 740     &hf_ubx_rxm_rawx_trkstat_prvalid,
 741     &hf_ubx_rxm_rawx_trkstat_cpvalid,
 742     &hf_ubx_rxm_rawx_trkstat_halfcyc,
 743     &hf_ubx_rxm_rawx_trkstat_subhalfcyc,
 744     NULL
 745 };
 746
 747 static int hf_ubx_rxm_sfrbx;
 748 static int hf_ubx_rxm_sfrbx_gnssid;
 749 static int hf_ubx_rxm_sfrbx_svid;
 750 static int hf_ubx_rxm_sfrbx_sigid;
 751 static int hf_ubx_rxm_sfrbx_freqid;
 752 static int hf_ubx_rxm_sfrbx_numwords;
 753 static int hf_ubx_rxm_sfrbx_chn;
 754 static int hf_ubx_rxm_sfrbx_version;
 755 static int hf_ubx_rxm_sfrbx_dwrd;
 756 static int hf_ubx_rxm_sfrbx_reserved1;
 757 static int hf_ubx_rxm_sfrbx_reserved2;
 758 static int hf_ubx_rxm_sfrbx_reserved3;
 759
 760 static dissector_table_t ubx_class_id_dissector_table;
 761 static dissector_table_t ubx_gnssid_dissector_table;
 762
 763 static expert_field ei_ubx_chksum;
 764
 765 static int ett_ubx;
 766 static int ett_ubx_ack_ack;
 767 static int ett_ubx_ack_nak;
 768 static int ett_ubx_cfg_gnss;
 769 static int ett_ubx_cfg_gnss_block[255];
 770 static int ett_ubx_cfg_sbas;
 771 static int ett_ubx_cfg_sbas_mode;
 772 static int ett_ubx_cfg_sbas_scanmode;
 773 static int ett_ubx_nav_dop;
 774 static int ett_ubx_nav_eoe;
 775 static int ett_ubx_nav_odo;
 776 static int ett_ubx_nav_posecef;
 777 static int ett_ubx_nav_pvt;
 778 static int ett_ubx_nav_pvt_datetime;
 779 static int ett_ubx_nav_pvt_valid;
 780 static int ett_ubx_nav_pvt_flags;
 781 static int ett_ubx_nav_pvt_flags2;
 782 static int ett_ubx_nav_sat;
 783 static int ett_ubx_nav_sat_sv_info[255];
 784 static int ett_ubx_nav_sat_flags;
 785 static int ett_ubx_nav_sbas;
 786 static int ett_ubx_nav_sbas_service;
 787 static int ett_ubx_nav_sbas_sv_info[255];
 788 static int ett_ubx_nav_timegps;
 789 static int ett_ubx_nav_timegps_tow;
 790 static int ett_ubx_nav_timegps_valid;
 791 static int ett_ubx_nav_timeutc;
 792 static int ett_ubx_nav_timeutc_valid;
 793 static int ett_ubx_nav_velecef;
 794 static int ett_ubx_rxm_measx;
 795 static int ett_ubx_rxm_measx_meas[255];
 796 static int ett_ubx_rxm_rawx;
 797 static int ett_ubx_rxm_rawx_recstat;
 798 static int ett_ubx_rxm_rawx_trkstat;
 799 static int ett_ubx_rxm_rawx_meas[255];
 800 static int ett_ubx_rxm_sfrbx;
 801
 802 static dissector_handle_t ubx_handle;
 803
 804 /* compute the checksum for a UBX message (Fletcher 8-bit by RFC 1145 */
 805 static uint16_t chksum_fletcher_8(const uint8_t *data, const int len) {
 806     uint8_t ck_a = 0, ck_b = 0;
 807     int i;
 808
 809     for (i = 0; i < len; i++) {
 810         ck_a += data[i];
 811         ck_b += ck_a;
 812     }
 813
 814     return (ck_b << 8) | ck_a;
 815 }
 816
 817 /* Format code phase */
 818 static void fmt_codephase(char *label, uint32_t p) {
 819     snprintf(label, ITEM_LABEL_LENGTH, "%d * 2^-21 ms", p);
 820 }
 821
 822 /* Format carrier phase standard deviation */
 823 static void fmt_cpstdev(char *label, uint32_t p) {
 824     snprintf(label, ITEM_LABEL_LENGTH, "%d.%03d cycles", (p * 4) / 1000, (p * 4) % 1000);
 825 }
 826
 827 /* Format magnetic declination */
 828 static void fmt_decl(char *label, int32_t d) {
 829     if (d >= 0) {
 830         snprintf(label, ITEM_LABEL_LENGTH, "%d.%02d%s", d / 100, d % 100,
 831                 UTF8_DEGREE_SIGN);
 832     }
 833     else {
 834         snprintf(label, ITEM_LABEL_LENGTH, "-%d.%02d%s", -d / 100, -d % 100,
 835                 UTF8_DEGREE_SIGN);
 836     }
 837 }
 838
 839 /* Format magnetic declination accuracy */
 840 static void fmt_decl_acc(char *label, uint32_t a) {
 841     snprintf(label, ITEM_LABEL_LENGTH, "%d.%02d%s", a / 100,
 842             a % 100, UTF8_DEGREE_SIGN);
 843 }
 844
 845 /* Format Dilution of Precision */
 846 static void fmt_dop(char *label, uint32_t dop) {
 847     snprintf(label, ITEM_LABEL_LENGTH, "%i.%02i", dop / 100, dop % 100);
 848 }
 849
 850 /* Format Doppler measurement in m/s */
 851 static void fmt_dopplerms(char *label, int32_t d) {
 852     if (d >= 0) {
 853         snprintf(label, ITEM_LABEL_LENGTH, "%d.%02d m/s", d * 4 / 100, (d * 4) % 100);
 854     }
 855     else {
 856         snprintf(label, ITEM_LABEL_LENGTH, "-%d.%02d m/s", -d * 4 / 100, (-d * 4) % 100);
 857     }
 858 }
 859
 860 /* Format Doppler measurement in Hz */
 861 static void fmt_dopplerhz(char *label, int32_t d) {
 862     if (d >= 0) {
 863         snprintf(label, ITEM_LABEL_LENGTH, "%d.%01d Hz", d * 2 / 10, (d * 2) % 10);
 864     }
 865     else {
 866         snprintf(label, ITEM_LABEL_LENGTH, "-%d.%01d Hz", -d * 2 / 10, (-d * 2) % 10);
 867     }
 868 }
 869
 870 /* Format Doppler standard deviation */
 871 static void fmt_dostdev(char *label, uint32_t p) {
 872     snprintf(label, ITEM_LABEL_LENGTH, "%d.%03d Hz", (1 << p) * 2 / 1000, ((1 << p) * 2) % 1000);
 873 }
 874
 875 /* Format heading */
 876 static void fmt_heading(char *label, int32_t h) {
 877     if (h >= 0) {
 878         snprintf(label, ITEM_LABEL_LENGTH, "%d.%05d%s", h / 100000, h % 100000,
 879                 UTF8_DEGREE_SIGN);
 880     }
 881     else {
 882         snprintf(label, ITEM_LABEL_LENGTH, "-%d.%05d%s", -h / 100000,
 883                 -h % 100000, UTF8_DEGREE_SIGN);
 884     }
 885 }
 886
 887 /* Format heading accuracy */
 888 static void fmt_heading_acc(char *label, uint32_t a) {
 889     snprintf(label, ITEM_LABEL_LENGTH, "%d.%05d%s", a / 100000,
 890             a % 100000, UTF8_DEGREE_SIGN);
 891 }
 892
 893 /* Format latitude or longitude */
 894 static void fmt_lat_lon(char *label, int32_t l) {
 895     if (l >= 0) {
 896         snprintf(label, ITEM_LABEL_LENGTH, "%d.%07d%s", l / 10000000,
 897                 l % 10000000, UTF8_DEGREE_SIGN);
 898     }
 899     else {
 900         snprintf(label, ITEM_LABEL_LENGTH, "-%d.%07d%s", -l / 10000000,
 901                 -l % 10000000, UTF8_DEGREE_SIGN);
 902     }
 903 }
 904
 905 /* Format pseudo-range residuals */
 906 static void fmt_pr_res(char *label, int32_t p) {
 907     if (p >= 0) {
 908         snprintf(label, ITEM_LABEL_LENGTH, "%d.%01dm", p / 10, p % 10);
 909     }
 910     else {
 911         snprintf(label, ITEM_LABEL_LENGTH, "-%d.%01dm", -p / 10, -p % 10);
 912     }
 913 }
 914
 915 /* Format pseudo-range standard deviation */
 916 static void fmt_prstdev(char *label, uint32_t p) {
 917     snprintf(label, ITEM_LABEL_LENGTH, "%d.%02dm", (1 << p) / 100, (1 << p) % 100);
 918 }
 919
 920 /* Format measurement reference time accuracy */
 921 static void fmt_towacc(char *label, uint32_t p) {
 922     snprintf(label, ITEM_LABEL_LENGTH, "%d.%04dms", p / 16, (p * 10000 / 16) % 10000);
 923 }
 924
 925 /* Dissect UBX message */
 926 static int dissect_ubx(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
 927     tvbuff_t *next_tvb;
 928     uint32_t msg_class_id, payload_len, cmp_chksum;
 929
 930     col_set_str(pinfo->cinfo, COL_PROTOCOL, "UBX");
 931     col_clear(pinfo->cinfo, COL_INFO);
 932
 933     payload_len = tvb_get_uint16(tvb, 4, ENC_LITTLE_ENDIAN);
 934
 935     proto_item *ti = proto_tree_add_item(tree, proto_ubx, tvb, 0,
 936             UBX_HEADER_SIZE + payload_len + UBX_CHKSUM_SIZE, ENC_NA);
 937     proto_tree *ubx_tree = proto_item_add_subtree(ti, ett_ubx);
 938
 939     // dissect the registered fields
 940     proto_tree_add_item(ubx_tree, hf_ubx_preamble,
 941             tvb, 0, 2, ENC_BIG_ENDIAN);
 942     proto_tree_add_item_ret_uint(ubx_tree, hf_ubx_msg_class_id,
 943             tvb, 2, 2, ENC_BIG_ENDIAN, &msg_class_id);
 944     proto_tree_add_item(ubx_tree, hf_ubx_payload_len,
 945             tvb, 4, 2, ENC_LITTLE_ENDIAN);
 946
 947     // checksum
 948     cmp_chksum = chksum_fletcher_8(
 949             (uint8_t *)tvb_memdup(pinfo->pool, tvb, 2, UBX_HEADER_SIZE + payload_len - 2),
 950             UBX_HEADER_SIZE + payload_len - 2);
 951     proto_tree_add_checksum(ubx_tree,
 952             tvb, UBX_HEADER_SIZE + payload_len,
 953             hf_ubx_chksum, -1, &ei_ubx_chksum, NULL, cmp_chksum,
 954             ENC_LITTLE_ENDIAN, PROTO_CHECKSUM_VERIFY);
 955
 956     // send the payload to the next dissector
 957     next_tvb = tvb_new_subset_length(tvb, UBX_HEADER_SIZE, payload_len);
 958     if (!dissector_try_uint(ubx_class_id_dissector_table, msg_class_id,
 959                 next_tvb, pinfo, tree)) {
 960         call_data_dissector(next_tvb, pinfo, tree);
 961     }
 962
 963     return tvb_captured_length(tvb);
 964 }
 965
 966 /* Dissect UBX-ACK-ACK message */
 967 static int dissect_ubx_ack_ack(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
 968     col_set_str(pinfo->cinfo, COL_PROTOCOL, "UBX-ACK-ACK");
 969     col_clear(pinfo->cinfo, COL_INFO);
 970
 971     proto_item *ti = proto_tree_add_item(tree, hf_ubx_ack_ack, tvb, 0, 2, ENC_NA);
 972     proto_tree *ubx_ack_ack_tree = proto_item_add_subtree(ti, ett_ubx_ack_ack);
 973
 974     // dissect the registered fields
 975     proto_tree_add_item(ubx_ack_ack_tree, hf_ubx_ack_ack_msg_class_id,
 976             tvb, 0, 2, ENC_BIG_ENDIAN);
 977
 978     return tvb_captured_length(tvb);
 979 }
 980
 981 /* Dissect UBX-ACK-NAK message */
 982 static int dissect_ubx_ack_nak(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
 983     col_set_str(pinfo->cinfo, COL_PROTOCOL, "UBX-ACK-NAK");
 984     col_clear(pinfo->cinfo, COL_INFO);
 985
 986     proto_item *ti = proto_tree_add_item(tree, hf_ubx_ack_nak, tvb, 0, 2, ENC_NA);
 987     proto_tree *ubx_ack_nak_tree = proto_item_add_subtree(ti, ett_ubx_ack_nak);
 988
 989     // dissect the registered fields
 990     proto_tree_add_item(ubx_ack_nak_tree, hf_ubx_ack_nak_msg_class_id,
 991             tvb, 0, 2, ENC_BIG_ENDIAN);
 992
 993     return tvb_captured_length(tvb);
 994 }
 995
 996 /* Dissect UBX-CFG-SBAS message */
 997 static int dissect_ubx_cfg_gnss(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
 998     uint8_t i, num_config_blocks;
 999
1000     col_set_str(pinfo->cinfo, COL_PROTOCOL, "UBX-CFG-GNSS");
1001     col_clear(pinfo->cinfo, COL_INFO);
1002
1003     num_config_blocks = tvb_get_uint8(tvb, 3);
1004
1005     proto_item *ti = proto_tree_add_item(tree, hf_ubx_cfg_gnss,
1006             tvb, 0, 4 + 8 * num_config_blocks, ENC_NA);
1007     proto_tree *ubx_cfg_gnss_tree = proto_item_add_subtree(ti, ett_ubx_cfg_gnss);
1008
1009     // dissect the registered fields
1010     proto_tree_add_item(ubx_cfg_gnss_tree, hf_ubx_cfg_gnss_version,
1011             tvb, 0, 1, ENC_NA);
1012     proto_tree_add_item(ubx_cfg_gnss_tree, hf_ubx_cfg_gnss_numtrkchhw,
1013             tvb, 1, 1, ENC_NA);
1014     proto_tree_add_item(ubx_cfg_gnss_tree, hf_ubx_cfg_gnss_numtrkchuse,
1015             tvb, 2, 1, ENC_NA);
1016     proto_tree_add_item(ubx_cfg_gnss_tree, hf_ubx_cfg_gnss_numconfigblocks,
1017             tvb, 3, 1, ENC_NA);
1018
1019     for (i = 0; i < num_config_blocks; i++) {
1020         const uint8_t gnss_id = tvb_get_uint8(tvb, 4 + 8 * i);
1021         const uint8_t res_trk_ch = tvb_get_uint8(tvb, 5 + 8 * i);
1022         const uint8_t max_trk_ch = tvb_get_uint8(tvb, 6 + 8 * i);
1023
1024         proto_tree *gnss_blk_tree = proto_tree_add_subtree_format(ubx_cfg_gnss_tree,
1025                 tvb, 4 + 8 * i, 8, ett_ubx_cfg_gnss_block[i], NULL,
1026                 "%-7s (Res Trk Ch %2d, Max Trk Ch %2d)",
1027                 val_to_str_const(gnss_id, UBX_GNSS_ID, "Unknown GNSS ID"),
1028                 res_trk_ch, max_trk_ch);
1029
1030         proto_tree_add_item(gnss_blk_tree, hf_ubx_cfg_gnss_blk_gnssid,
1031             tvb,  4 + 8 * i, 1, ENC_NA);
1032         proto_tree_add_item(gnss_blk_tree, hf_ubx_cfg_gnss_blk_restrkch,
1033             tvb,  5 + 8 * i, 1, ENC_NA);
1034         proto_tree_add_item(gnss_blk_tree, hf_ubx_cfg_gnss_blk_maxtrkch,
1035             tvb,  6 + 8 * i, 1, ENC_NA);
1036         proto_tree_add_item(gnss_blk_tree, hf_ubx_cfg_gnss_blk_reserved1,
1037             tvb,  7 + 8 * i, 1, ENC_NA);
1038         proto_tree_add_item(gnss_blk_tree, hf_ubx_cfg_gnss_blk_enable,
1039             tvb,  8 + 8 * i, 4, ENC_LITTLE_ENDIAN);
1040
1041         int hf;
1042         switch (gnss_id) {
1043             case GNSS_ID_GPS:
1044                 hf = hf_ubx_cfg_gnss_blk_gps_sigcfgmask;
1045                 break;
1046             case GNSS_ID_SBAS:
1047                 hf = hf_ubx_cfg_gnss_blk_sbas_sigcfgmask;
1048                 break;
1049             case GNSS_ID_GALILEO:
1050                 hf = hf_ubx_cfg_gnss_blk_gal_sigcfgmask;
1051                 break;
1052             case GNSS_ID_BEIDOU:
1053                 hf = hf_ubx_cfg_gnss_blk_bds_sigcfgmask;
1054                 break;
1055             case GNSS_ID_IMES:
1056                 hf = hf_ubx_cfg_gnss_blk_imes_sigcfgmask;
1057                 break;
1058             case GNSS_ID_QZSS:
1059                 hf = hf_ubx_cfg_gnss_blk_qzss_sigcfgmask;
1060                 break;
1061             case GNSS_ID_GLONASS:
1062                 hf = hf_ubx_cfg_gnss_blk_glo_sigcfgmask;
1063                 break;
1064             default:
1065                 hf = hf_ubx_cfg_gnss_blk_sigcfgmask;
1066         }
1067         proto_tree_add_item(gnss_blk_tree, hf,
1068             tvb,  8 + 8 * i, 4, ENC_LITTLE_ENDIAN);
1069     }
1070
1071     return tvb_captured_length(tvb);
1072 }
1073
1074 /* Dissect UBX-CFG-SBAS message */
1075 static int dissect_ubx_cfg_sbas(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
1076     col_set_str(pinfo->cinfo, COL_PROTOCOL, "UBX-CFG-SBAS");
1077     col_clear(pinfo->cinfo, COL_INFO);
1078
1079     proto_item *ti = proto_tree_add_item(tree, hf_ubx_cfg_sbas, tvb, 0, 2, ENC_NA);
1080     proto_tree *ubx_cfg_sbas_tree = proto_item_add_subtree(ti, ett_ubx_cfg_sbas);
1081
1082     // dissect the registered fields
1083     proto_tree_add_bitmask(ubx_cfg_sbas_tree, tvb, 0, hf_ubx_cfg_sbas_mode,
1084             ett_ubx_cfg_sbas_mode, ubx_cfg_sbas_mode_fields, ENC_NA);
1085     proto_tree_add_item(ubx_cfg_sbas_tree, hf_ubx_cfg_sbas_usage_range,
1086             tvb, 1, 1, ENC_NA);
1087     proto_tree_add_item(ubx_cfg_sbas_tree, hf_ubx_cfg_sbas_usage_diffcorr,
1088             tvb, 1, 1, ENC_NA);
1089     proto_tree_add_item(ubx_cfg_sbas_tree, hf_ubx_cfg_sbas_usage_integrity,
1090             tvb, 1, 1, ENC_NA);
1091     proto_tree_add_item(ubx_cfg_sbas_tree, hf_ubx_cfg_sbas_max_sbas,
1092             tvb, 2, 1, ENC_NA);
1093
1094     // scanmode bitmask
1095     proto_tree *scanmode_tree = proto_tree_add_subtree(ubx_cfg_sbas_tree,
1096             tvb, 3, 5, ett_ubx_cfg_sbas_scanmode, NULL, "Scanmode bitmask");
1097     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn120,
1098             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1099     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn121,
1100             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1101     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn122,
1102             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1103     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn123,
1104             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1105     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn124,
1106             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1107     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn125,
1108             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1109     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn126,
1110             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1111     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn127,
1112             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1113     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn128,
1114             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1115     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn129,
1116             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1117     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn130,
1118             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1119     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn131,
1120             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1121     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn132,
1122             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1123     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn133,
1124             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1125     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn134,
1126             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1127     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn135,
1128             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1129     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn136,
1130             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1131     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn137,
1132             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1133     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn138,
1134             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1135     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn139,
1136             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1137     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn140,
1138             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1139     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn141,
1140             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1141     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn142,
1142             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1143     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn143,
1144             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1145     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn144,
1146             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1147     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn145,
1148             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1149     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn146,
1150             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1151     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn147,
1152             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1153     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn148,
1154             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1155     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn149,
1156             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1157     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn150,
1158             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1159     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn151,
1160             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1161     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn152,
1162             tvb, 3, 1, ENC_NA);
1163     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn153,
1164             tvb, 3, 1, ENC_NA);
1165     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn154,
1166             tvb, 3, 1, ENC_NA);
1167     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn155,
1168             tvb, 3, 1, ENC_NA);
1169     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn156,
1170             tvb, 3, 1, ENC_NA);
1171     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn157,
1172             tvb, 3, 1, ENC_NA);
1173     proto_tree_add_item(scanmode_tree, hf_ubx_cfg_sbas_scanmode_prn158,
1174             tvb, 3, 1, ENC_NA);
1175
1176     return tvb_captured_length(tvb);
1177 }
1178
1179 /* Dissect UBX-NAV-DOP message */
1180 static int dissect_ubx_nav_dop(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
1181     col_set_str(pinfo->cinfo, COL_PROTOCOL, "UBX-NAV-DOP");
1182     col_clear(pinfo->cinfo, COL_INFO);
1183
1184     proto_item *ti = proto_tree_add_item(tree, hf_ubx_nav_dop,
1185             tvb, 0, 18, ENC_NA);
1186     proto_tree *ubx_nav_dop_tree = proto_item_add_subtree(ti, ett_ubx_nav_dop);
1187
1188     // dissect the registered fields
1189     proto_tree_add_item(ubx_nav_dop_tree, hf_ubx_nav_dop_itow,
1190             tvb, 0, 4, ENC_LITTLE_ENDIAN);
1191     proto_tree_add_item(ubx_nav_dop_tree, hf_ubx_nav_dop_gdop, tvb,  4, 2, ENC_LITTLE_ENDIAN);
1192     proto_tree_add_item(ubx_nav_dop_tree, hf_ubx_nav_dop_pdop, tvb,  6, 2, ENC_LITTLE_ENDIAN);
1193     proto_tree_add_item(ubx_nav_dop_tree, hf_ubx_nav_dop_tdop, tvb,  8, 2, ENC_LITTLE_ENDIAN);
1194     proto_tree_add_item(ubx_nav_dop_tree, hf_ubx_nav_dop_vdop, tvb, 10, 2, ENC_LITTLE_ENDIAN);
1195     proto_tree_add_item(ubx_nav_dop_tree, hf_ubx_nav_dop_hdop, tvb, 12, 2, ENC_LITTLE_ENDIAN);
1196     proto_tree_add_item(ubx_nav_dop_tree, hf_ubx_nav_dop_ndop, tvb, 14, 2, ENC_LITTLE_ENDIAN);
1197     proto_tree_add_item(ubx_nav_dop_tree, hf_ubx_nav_dop_edop, tvb, 16, 2, ENC_LITTLE_ENDIAN);
1198
1199     return tvb_captured_length(tvb);
1200 }
1201
1202 /* Dissect UBX-NAV-EOE message */
1203 static int dissect_ubx_nav_eoe(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
1204     col_set_str(pinfo->cinfo, COL_PROTOCOL, "UBX-NAV-EOE");
1205     col_clear(pinfo->cinfo, COL_INFO);
1206
1207     proto_item *ti = proto_tree_add_item(tree, hf_ubx_nav_eoe,
1208             tvb, 0, 4, ENC_NA);
1209     proto_tree *ubx_nav_eoe_tree = proto_item_add_subtree(ti, ett_ubx_nav_eoe);
1210
1211     // dissect the registered fields
1212     proto_tree_add_item(ubx_nav_eoe_tree, hf_ubx_nav_eoe_itow,
1213             tvb, 0, 4, ENC_LITTLE_ENDIAN);
1214
1215     return tvb_captured_length(tvb);
1216 }
1217
1218 /* Dissect UBX-NAV-ODO message */
1219 static int dissect_ubx_nav_odo(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
1220     col_set_str(pinfo->cinfo, COL_PROTOCOL, "UBX-NAV-ODO");
1221     col_clear(pinfo->cinfo, COL_INFO);
1222
1223     proto_item *ti = proto_tree_add_item(tree, hf_ubx_nav_odo,
1224             tvb, 0, 20, ENC_NA);
1225     proto_tree *ubx_nav_odo_tree = proto_item_add_subtree(ti, ett_ubx_nav_odo);
1226
1227     // dissect the registered fields
1228     proto_tree_add_item(ubx_nav_odo_tree, hf_ubx_nav_odo_version,
1229             tvb, 0, 1, ENC_NA);
1230     proto_tree_add_item(ubx_nav_odo_tree, hf_ubx_nav_odo_reserved1,
1231             tvb, 1, 3, ENC_LITTLE_ENDIAN);
1232     proto_tree_add_item(ubx_nav_odo_tree, hf_ubx_nav_odo_itow,
1233             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1234     proto_tree_add_item(ubx_nav_odo_tree, hf_ubx_nav_odo_distance,
1235             tvb, 8, 4, ENC_LITTLE_ENDIAN);
1236     proto_tree_add_item(ubx_nav_odo_tree, hf_ubx_nav_odo_totaldistance,
1237             tvb, 12, 4, ENC_LITTLE_ENDIAN);
1238     proto_tree_add_item(ubx_nav_odo_tree, hf_ubx_nav_odo_distancestd,
1239             tvb, 16, 4, ENC_LITTLE_ENDIAN);
1240
1241     return tvb_captured_length(tvb);
1242 }
1243
1244 /* Dissect UBX-NAV-POSECEF message */
1245 static int dissect_ubx_nav_posecef(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
1246     col_set_str(pinfo->cinfo, COL_PROTOCOL, "UBX-NAV-POSECEF");
1247     col_clear(pinfo->cinfo, COL_INFO);
1248
1249     proto_item *ti = proto_tree_add_item(tree, hf_ubx_nav_posecef,
1250             tvb, 0, 20, ENC_NA);
1251     proto_tree *ubx_nav_posecef_tree = proto_item_add_subtree(ti, ett_ubx_nav_posecef);
1252
1253     // dissect the registered fields
1254     proto_tree_add_item(ubx_nav_posecef_tree, hf_ubx_nav_posecef_itow,
1255             tvb, 0, 4, ENC_LITTLE_ENDIAN);
1256     proto_tree_add_item(ubx_nav_posecef_tree, hf_ubx_nav_posecef_ecefx,
1257             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1258     proto_tree_add_item(ubx_nav_posecef_tree, hf_ubx_nav_posecef_ecefy,
1259             tvb, 8, 4, ENC_LITTLE_ENDIAN);
1260     proto_tree_add_item(ubx_nav_posecef_tree, hf_ubx_nav_posecef_ecefz,
1261             tvb, 12, 4, ENC_LITTLE_ENDIAN);
1262     proto_tree_add_item(ubx_nav_posecef_tree, hf_ubx_nav_posecef_pacc,
1263             tvb, 16, 4, ENC_LITTLE_ENDIAN);
1264
1265     return tvb_captured_length(tvb);
1266 }
1267
1268 /* Dissect UBX-NAV-PVT message */
1269 static int dissect_ubx_nav_pvt(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
1270     col_set_str(pinfo->cinfo, COL_PROTOCOL, "UBX-NAV-PVT");
1271     col_clear(pinfo->cinfo, COL_INFO);
1272
1273     proto_item *ti = proto_tree_add_item(tree, hf_ubx_nav_pvt,
1274             tvb, 0, 92, ENC_NA);
1275     proto_tree *ubx_nav_pvt_tree = proto_item_add_subtree(ti, ett_ubx_nav_pvt);
1276
1277     // dissect the registered fields
1278     proto_tree_add_item(ubx_nav_pvt_tree, hf_ubx_nav_pvt_itow,
1279             tvb, 0, 4, ENC_LITTLE_ENDIAN);
1280
1281     // dissect date & time
1282     uint16_t year = tvb_get_int16(tvb, 4, ENC_LITTLE_ENDIAN);
1283     uint8_t month = tvb_get_int8(tvb, 6);
1284     uint8_t day = tvb_get_int8(tvb, 7);
1285     uint8_t hour = tvb_get_int8(tvb, 8);
1286     uint8_t min = tvb_get_int8(tvb, 9);
1287     uint8_t sec = tvb_get_int8(tvb, 10);
1288     proto_tree *datetime_tree = proto_tree_add_subtree_format(ubx_nav_pvt_tree,
1289             tvb, 4, 7, ett_ubx_nav_pvt_datetime, NULL,
1290             "Date/time: %04d-%02d-%02d %02d:%02d:%02d",
1291             year, month, day, hour, min, sec);
1292     proto_tree_add_item(datetime_tree, hf_ubx_nav_pvt_year,
1293             tvb, 4, 2, ENC_LITTLE_ENDIAN);
1294     proto_tree_add_item(datetime_tree, hf_ubx_nav_pvt_month,
1295             tvb, 6, 1, ENC_NA);
1296     proto_tree_add_item(datetime_tree, hf_ubx_nav_pvt_day,
1297             tvb, 7, 1, ENC_NA);
1298     proto_tree_add_item(datetime_tree, hf_ubx_nav_pvt_hour,
1299             tvb, 8, 1, ENC_NA);
1300     proto_tree_add_item(datetime_tree, hf_ubx_nav_pvt_min,
1301             tvb, 9, 1, ENC_NA);
1302     proto_tree_add_item(datetime_tree, hf_ubx_nav_pvt_sec,
1303             tvb, 10, 1, ENC_NA);
1304
1305     proto_tree_add_bitmask(ubx_nav_pvt_tree, tvb, 11, hf_ubx_nav_pvt_valid,
1306             ett_ubx_nav_pvt_valid, ubx_nav_pvt_valid_fields, ENC_NA);
1307     proto_tree_add_item(ubx_nav_pvt_tree, hf_ubx_nav_pvt_tacc,
1308             tvb, 12, 4, ENC_LITTLE_ENDIAN);
1309     proto_tree_add_item(ubx_nav_pvt_tree, hf_ubx_nav_pvt_nano,
1310             tvb, 16, 4, ENC_LITTLE_ENDIAN);
1311     proto_tree_add_item(ubx_nav_pvt_tree, hf_ubx_nav_pvt_fixtype,
1312             tvb, 20, 1, ENC_NA);
1313     proto_tree_add_bitmask(ubx_nav_pvt_tree, tvb, 21, hf_ubx_nav_pvt_flags,
1314             ett_ubx_nav_pvt_flags, ubx_nav_pvt_flags_fields, ENC_NA);
1315     proto_tree_add_bitmask(ubx_nav_pvt_tree, tvb, 22, hf_ubx_nav_pvt_flags2,
1316             ett_ubx_nav_pvt_flags2, ubx_nav_pvt_flags2_fields, ENC_NA);
1317     proto_tree_add_item(ubx_nav_pvt_tree, hf_ubx_nav_pvt_numsv,
1318             tvb, 23, 1, ENC_NA);
1319     proto_tree_add_item(ubx_nav_pvt_tree, hf_ubx_nav_pvt_lon,
1320             tvb, 24, 4, ENC_LITTLE_ENDIAN);
1321     proto_tree_add_item(ubx_nav_pvt_tree, hf_ubx_nav_pvt_lat,
1322             tvb, 28, 4, ENC_LITTLE_ENDIAN);
1323     proto_tree_add_item(ubx_nav_pvt_tree, hf_ubx_nav_pvt_height,
1324             tvb, 32, 4, ENC_LITTLE_ENDIAN);
1325     proto_tree_add_item(ubx_nav_pvt_tree, hf_ubx_nav_pvt_hmsl,
1326             tvb, 36, 4, ENC_LITTLE_ENDIAN);
1327     proto_tree_add_item(ubx_nav_pvt_tree, hf_ubx_nav_pvt_hacc,
1328             tvb, 40, 4, ENC_LITTLE_ENDIAN);
1329     proto_tree_add_item(ubx_nav_pvt_tree, hf_ubx_nav_pvt_vacc,
1330             tvb, 44, 4, ENC_LITTLE_ENDIAN);
1331     proto_tree_add_item(ubx_nav_pvt_tree, hf_ubx_nav_pvt_veln,
1332             tvb, 48, 4, ENC_LITTLE_ENDIAN);
1333     proto_tree_add_item(ubx_nav_pvt_tree, hf_ubx_nav_pvt_vele,
1334             tvb, 52, 4, ENC_LITTLE_ENDIAN);
1335     proto_tree_add_item(ubx_nav_pvt_tree, hf_ubx_nav_pvt_veld,
1336             tvb, 56, 4, ENC_LITTLE_ENDIAN);
1337     proto_tree_add_item(ubx_nav_pvt_tree, hf_ubx_nav_pvt_gspeed,
1338             tvb, 60, 4, ENC_LITTLE_ENDIAN);
1339     proto_tree_add_item(ubx_nav_pvt_tree, hf_ubx_nav_pvt_headmot,
1340             tvb, 64, 4, ENC_LITTLE_ENDIAN);
1341     proto_tree_add_item(ubx_nav_pvt_tree, hf_ubx_nav_pvt_sacc,
1342             tvb, 68, 4, ENC_LITTLE_ENDIAN);
1343     proto_tree_add_item(ubx_nav_pvt_tree, hf_ubx_nav_pvt_headacc,
1344             tvb, 72, 4, ENC_LITTLE_ENDIAN);
1345     proto_tree_add_item(ubx_nav_pvt_tree, hf_ubx_nav_pvt_pdop,
1346             tvb, 76, 2, ENC_LITTLE_ENDIAN);
1347     proto_tree_add_item(ubx_nav_pvt_tree, hf_ubx_nav_pvt_invalidllh,
1348             tvb, 78, 2, ENC_LITTLE_ENDIAN);
1349     proto_tree_add_item(ubx_nav_pvt_tree, hf_ubx_nav_pvt_lastcorrectionage,
1350             tvb, 78, 2, ENC_LITTLE_ENDIAN);
1351     proto_tree_add_item(ubx_nav_pvt_tree, hf_ubx_nav_pvt_reserved1,
1352             tvb, 80, 4, ENC_LITTLE_ENDIAN);
1353     proto_tree_add_item(ubx_nav_pvt_tree, hf_ubx_nav_pvt_headveh,
1354             tvb, 84, 4, ENC_LITTLE_ENDIAN);
1355     proto_tree_add_item(ubx_nav_pvt_tree, hf_ubx_nav_pvt_magdec,
1356             tvb, 88, 2, ENC_LITTLE_ENDIAN);
1357     proto_tree_add_item(ubx_nav_pvt_tree, hf_ubx_nav_pvt_magacc,
1358             tvb, 90, 2, ENC_LITTLE_ENDIAN);
1359
1360     return tvb_captured_length(tvb);
1361 }
1362
1363 /* Dissect UBX-NAV-SAT message */
1364 static int dissect_ubx_nav_sat(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
1365     uint16_t i;
1366     uint32_t num_svs;
1367
1368     col_set_str(pinfo->cinfo, COL_PROTOCOL, "UBX-NAV-SAT");
1369     col_clear(pinfo->cinfo, COL_INFO);
1370
1371     num_svs = tvb_get_uint8(tvb, 5);
1372
1373     proto_item *ti = proto_tree_add_item(tree, hf_ubx_nav_sat,
1374             tvb, 0, 8 + 12 * num_svs, ENC_NA);
1375     proto_tree *ubx_nav_sat_tree = proto_item_add_subtree(ti, ett_ubx_nav_sat);
1376
1377     // dissect the registered fields
1378     proto_tree_add_item(ubx_nav_sat_tree, hf_ubx_nav_sat_itow,
1379             tvb, 0, 4, ENC_LITTLE_ENDIAN);
1380     proto_tree_add_item(ubx_nav_sat_tree, hf_ubx_nav_sat_version,
1381             tvb, 4, 1, ENC_NA);
1382     proto_tree_add_item(ubx_nav_sat_tree, hf_ubx_nav_sat_num_svs,
1383             tvb, 5, 1, ENC_NA);
1384     proto_tree_add_item(ubx_nav_sat_tree, hf_ubx_nav_sat_reserved1,
1385             tvb, 6, 2, ENC_NA);
1386
1387     for (i = 0; i < num_svs; i++) {
1388         const uint8_t gnss_id = tvb_get_uint8(tvb, 8 + 12 * i);
1389         const uint8_t sv_id = tvb_get_uint8(tvb, 9 + 12 * i);
1390         const uint32_t used = (tvb_get_uint32(tvb, 16 + 12 * i, ENC_LITTLE_ENDIAN) & 0x0008) >> 3;
1391
1392         proto_tree *sv_info_tree = proto_tree_add_subtree_format(ubx_nav_sat_tree,
1393                 tvb, 8 + 12 * i, 12, ett_ubx_nav_sat_sv_info[i], NULL,
1394                 "%-7s / SV ID %3d, used %d",
1395                 val_to_str_const(gnss_id, UBX_GNSS_ID, "Unknown GNSS ID"),
1396                 sv_id, used);
1397
1398         proto_tree_add_item(sv_info_tree, hf_ubx_nav_sat_gnss_id,
1399             tvb,  8 + 12 * i, 1, ENC_NA);
1400         proto_tree_add_item(sv_info_tree, hf_ubx_nav_sat_sv_id,
1401             tvb,  9 + 12 * i, 1, ENC_NA);
1402         proto_tree_add_item(sv_info_tree, hf_ubx_nav_sat_cn0,
1403             tvb, 10 + 12 * i, 1, ENC_NA);
1404         proto_tree_add_item(sv_info_tree, hf_ubx_nav_sat_elev,
1405             tvb, 11 + 12 * i, 1, ENC_NA);
1406         proto_tree_add_item(sv_info_tree, hf_ubx_nav_sat_azim,
1407             tvb, 12 + 12 * i, 2, ENC_LITTLE_ENDIAN);
1408         proto_tree_add_item(sv_info_tree, hf_ubx_nav_sat_pr_res,
1409             tvb, 14 + 12 * i, 2, ENC_LITTLE_ENDIAN);
1410         proto_tree_add_bitmask(sv_info_tree, tvb, 16 + 12 * i,
1411                 hf_ubx_nav_sat_flags, ett_ubx_nav_sat_flags,
1412                 ubx_nav_sat_flags_fields, ENC_LITTLE_ENDIAN);
1413     }
1414
1415     return tvb_captured_length(tvb);
1416 }
1417
1418 /* Dissect UBX-NAV-SBAS message */
1419 static int dissect_ubx_nav_sbas(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
1420     uint16_t i;
1421     uint32_t num_svs;
1422
1423     col_set_str(pinfo->cinfo, COL_PROTOCOL, "UBX-NAV-SBAS");
1424     col_clear(pinfo->cinfo, COL_INFO);
1425
1426     num_svs = tvb_get_uint8(tvb, 8);
1427
1428     proto_item *ti = proto_tree_add_item(tree, hf_ubx_nav_sbas,
1429             tvb, 0, 12 + 12 * num_svs, ENC_NA);
1430     proto_tree *ubx_nav_sbas_tree = proto_item_add_subtree(ti, ett_ubx_nav_sbas);
1431
1432     proto_tree_add_item(ubx_nav_sbas_tree, hf_ubx_nav_sbas_itow,
1433             tvb, 0, 4, ENC_LITTLE_ENDIAN);
1434     proto_tree_add_item(ubx_nav_sbas_tree, hf_ubx_nav_sbas_geo,
1435             tvb, 4, 1, ENC_NA);
1436     proto_tree_add_item(ubx_nav_sbas_tree, hf_ubx_nav_sbas_mode,
1437             tvb, 5, 1, ENC_NA);
1438     proto_tree_add_item(ubx_nav_sbas_tree, hf_ubx_nav_sbas_sys,
1439             tvb, 6, 1, ENC_NA);
1440     proto_tree_add_bitmask(ubx_nav_sbas_tree, tvb, 7, hf_ubx_nav_sbas_service,
1441             ett_ubx_nav_sbas_service, ubx_nav_sbas_service_fields, ENC_NA);
1442     proto_tree_add_item(ubx_nav_sbas_tree, hf_ubx_nav_sbas_cnt,
1443             tvb, 8, 1, ENC_NA);
1444     proto_tree_add_item(ubx_nav_sbas_tree, hf_ubx_nav_sbas_reserved1,
1445             tvb, 9, 3, ENC_LITTLE_ENDIAN);
1446
1447     for (i = 0; i < num_svs; i++) {
1448         const uint8_t sv_id = tvb_get_uint8(tvb, 12 + 12 * i);
1449
1450         proto_tree *sv_info_tree = proto_tree_add_subtree_format(ubx_nav_sbas_tree,
1451                 tvb, 12 + 12 * i, 12, ett_ubx_nav_sbas_sv_info[i], NULL,
1452                 "SV ID %3d", sv_id);
1453
1454         proto_tree_add_item(sv_info_tree, hf_ubx_nav_sbas_sv_id,
1455             tvb,  12 + 12 * i, 1, ENC_NA);
1456         proto_tree_add_item(sv_info_tree, hf_ubx_nav_sbas_flags,
1457             tvb,  13 + 12 * i, 1, ENC_NA);
1458         proto_tree_add_item(sv_info_tree, hf_ubx_nav_sbas_udre,
1459             tvb,  14 + 12 * i, 1, ENC_NA);
1460         proto_tree_add_item(sv_info_tree, hf_ubx_nav_sbas_sv_sys,
1461             tvb,  15 + 12 * i, 1, ENC_NA);
1462         proto_tree_add_item(sv_info_tree, hf_ubx_nav_sbas_sv_service,
1463             tvb,  16 + 12 * i, 1, ENC_NA);
1464         proto_tree_add_item(sv_info_tree, hf_ubx_nav_sbas_reserved2,
1465             tvb,  17 + 12 * i, 1, ENC_NA);
1466         proto_tree_add_item(sv_info_tree, hf_ubx_nav_sbas_prc,
1467             tvb,  18 + 12 * i, 2, ENC_LITTLE_ENDIAN);
1468         proto_tree_add_item(sv_info_tree, hf_ubx_nav_sbas_reserved3,
1469             tvb,  20 + 12 * i, 2, ENC_LITTLE_ENDIAN);
1470         proto_tree_add_item(sv_info_tree, hf_ubx_nav_sbas_ic,
1471             tvb,  22 + 12 * i, 2, ENC_LITTLE_ENDIAN);
1472     }
1473
1474     return tvb_captured_length(tvb);
1475 }
1476
1477 /* Dissect UBX-NAV-TIMEGPS message */
1478 static int dissect_ubx_nav_timegps(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
1479     uint32_t itow;
1480     int32_t ftow;
1481
1482     col_set_str(pinfo->cinfo, COL_PROTOCOL, "UBX-NAV-TIMEGPS");
1483     col_clear(pinfo->cinfo, COL_INFO);
1484
1485     proto_item *ti = proto_tree_add_item(tree, hf_ubx_nav_timegps,
1486             tvb, 0, 16, ENC_NA);
1487     proto_tree *ubx_nav_timegps_tree = proto_item_add_subtree(ti, ett_ubx_nav_timegps);
1488
1489     // dissect the registered fields
1490     itow = tvb_get_uint32(tvb, 0, ENC_LITTLE_ENDIAN);
1491     ftow = tvb_get_int32(tvb, 4, ENC_LITTLE_ENDIAN);
1492     ftow = (itow % 1000) * 1000000 + ftow;
1493     itow = itow / 1000;
1494     if (ftow < 0) {
1495         itow = itow - 1;
1496         ftow = 1000000000 + ftow;
1497     }
1498     proto_tree *tow_tree = proto_tree_add_subtree_format(ubx_nav_timegps_tree,
1499             tvb, 0, 8, ett_ubx_nav_timegps_tow, NULL, "TOW: %d.%09ds", itow, ftow);
1500     proto_tree_add_item(tow_tree, hf_ubx_nav_timegps_itow,
1501             tvb, 0, 4, ENC_LITTLE_ENDIAN);
1502     proto_tree_add_item(tow_tree, hf_ubx_nav_timegps_ftow,
1503             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1504
1505     proto_tree_add_item(ubx_nav_timegps_tree, hf_ubx_nav_timegps_week,
1506             tvb, 8, 2, ENC_LITTLE_ENDIAN);
1507     proto_tree_add_item(ubx_nav_timegps_tree, hf_ubx_nav_timegps_leaps,
1508             tvb, 10, 1, ENC_NA);
1509     proto_tree_add_bitmask(ubx_nav_timegps_tree, tvb, 11,
1510             hf_ubx_nav_timegps_valid, ett_ubx_nav_timegps_valid,
1511             ubx_nav_timegps_valid_fields, ENC_NA);
1512     proto_tree_add_item(ubx_nav_timegps_tree, hf_ubx_nav_timegps_tacc,
1513             tvb, 12, 4, ENC_LITTLE_ENDIAN);
1514
1515     return tvb_captured_length(tvb);
1516 }
1517
1518 /* Dissect UBX-NAV-TIMEUTC message */
1519 static int dissect_ubx_nav_timeutc(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
1520     col_set_str(pinfo->cinfo, COL_PROTOCOL, "UBX-NAV-TIMEUTC");
1521     col_clear(pinfo->cinfo, COL_INFO);
1522
1523     proto_item *ti = proto_tree_add_item(tree, hf_ubx_nav_timeutc,
1524             tvb, 0, 20, ENC_NA);
1525     proto_tree *ubx_nav_timeutc_tree = proto_item_add_subtree(ti, ett_ubx_nav_timeutc);
1526
1527     proto_tree_add_item(ubx_nav_timeutc_tree, hf_ubx_nav_timeutc_itow,
1528             tvb, 0, 4, ENC_LITTLE_ENDIAN);
1529     proto_tree_add_item(ubx_nav_timeutc_tree, hf_ubx_nav_timeutc_tacc,
1530             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1531     proto_tree_add_item(ubx_nav_timeutc_tree, hf_ubx_nav_timeutc_nano,
1532             tvb, 8, 4, ENC_LITTLE_ENDIAN);
1533     proto_tree_add_item(ubx_nav_timeutc_tree, hf_ubx_nav_timeutc_year,
1534             tvb, 12, 2, ENC_LITTLE_ENDIAN);
1535     proto_tree_add_item(ubx_nav_timeutc_tree, hf_ubx_nav_timeutc_month,
1536             tvb, 14, 1, ENC_NA);
1537     proto_tree_add_item(ubx_nav_timeutc_tree, hf_ubx_nav_timeutc_day,
1538             tvb, 15, 1, ENC_NA);
1539     proto_tree_add_item(ubx_nav_timeutc_tree, hf_ubx_nav_timeutc_hour,
1540             tvb, 16, 1, ENC_NA);
1541     proto_tree_add_item(ubx_nav_timeutc_tree, hf_ubx_nav_timeutc_min,
1542             tvb, 17, 1, ENC_NA);
1543     proto_tree_add_item(ubx_nav_timeutc_tree, hf_ubx_nav_timeutc_sec,
1544             tvb, 18, 1, ENC_NA);
1545     proto_tree_add_bitmask(ubx_nav_timeutc_tree, tvb, 19,
1546             hf_ubx_nav_timeutc_valid, ett_ubx_nav_timeutc_valid,
1547             ubx_nav_timeutc_valid_fields, ENC_NA);
1548
1549     return tvb_captured_length(tvb);
1550 }
1551
1552 /* Dissect UBX-NAV-VELECEF message */
1553 static int dissect_ubx_nav_velecef(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
1554     col_set_str(pinfo->cinfo, COL_PROTOCOL, "UBX-NAV-VELECEF");
1555     col_clear(pinfo->cinfo, COL_INFO);
1556
1557     proto_item *ti = proto_tree_add_item(tree, hf_ubx_nav_velecef,
1558             tvb, 0, 20, ENC_NA);
1559     proto_tree *ubx_nav_velecef_tree = proto_item_add_subtree(ti, ett_ubx_nav_velecef);
1560
1561     // dissect the registered fields
1562     proto_tree_add_item(ubx_nav_velecef_tree, hf_ubx_nav_velecef_itow,
1563             tvb, 0, 4, ENC_LITTLE_ENDIAN);
1564     proto_tree_add_item(ubx_nav_velecef_tree, hf_ubx_nav_velecef_ecefvx,
1565             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1566     proto_tree_add_item(ubx_nav_velecef_tree, hf_ubx_nav_velecef_ecefvy,
1567             tvb, 8, 4, ENC_LITTLE_ENDIAN);
1568     proto_tree_add_item(ubx_nav_velecef_tree, hf_ubx_nav_velecef_ecefvz,
1569             tvb, 12, 4, ENC_LITTLE_ENDIAN);
1570     proto_tree_add_item(ubx_nav_velecef_tree, hf_ubx_nav_velecef_sacc,
1571             tvb, 16, 4, ENC_LITTLE_ENDIAN);
1572
1573     return tvb_captured_length(tvb);
1574 }
1575
1576 /* Dissect UBX-RXM-MEASX message */
1577 static int dissect_ubx_rxm_measx(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
1578     uint32_t i, numsv;
1579
1580     col_set_str(pinfo->cinfo, COL_PROTOCOL, "UBX-RXM-MEASX");
1581     col_clear(pinfo->cinfo, COL_INFO);
1582
1583     numsv = tvb_get_uint8(tvb, 34);
1584
1585     proto_item *ti = proto_tree_add_item(tree, hf_ubx_rxm_measx,
1586             tvb, 0, 44 + numsv * 24, ENC_NA);
1587     proto_tree *ubx_rxm_measx_tree = proto_item_add_subtree(ti, ett_ubx_rxm_measx);
1588
1589     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_version,
1590             tvb, 0, 1, ENC_NA);
1591     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_reserved1,
1592             tvb, 1, 3, ENC_LITTLE_ENDIAN);
1593     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_gpstow,
1594             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1595     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_glotow,
1596             tvb, 8, 4, ENC_LITTLE_ENDIAN);
1597     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_bdstow,
1598             tvb, 12, 4, ENC_LITTLE_ENDIAN);
1599     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_reserved2,
1600             tvb, 16, 4, ENC_LITTLE_ENDIAN);
1601     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_qzsstow,
1602             tvb, 20, 4, ENC_LITTLE_ENDIAN);
1603     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_gpstowacc,
1604             tvb, 24, 2, ENC_LITTLE_ENDIAN);
1605     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_glotowacc,
1606             tvb, 26, 2, ENC_LITTLE_ENDIAN);
1607     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_bdstowacc,
1608             tvb, 28, 2, ENC_LITTLE_ENDIAN);
1609     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_reserved3,
1610             tvb, 30, 2, ENC_LITTLE_ENDIAN);
1611     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_qzsstowacc,
1612             tvb, 32, 2, ENC_LITTLE_ENDIAN);
1613     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_numsv,
1614             tvb, 34, 1, ENC_NA);
1615     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_flags_towset,
1616             tvb, 35, 1, ENC_NA);
1617     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_reserved4,
1618             tvb, 36, 8, ENC_LITTLE_ENDIAN);
1619
1620     for (i = 0; i < numsv; i++) {
1621         const uint8_t gnss_id = tvb_get_uint8(tvb, 44 + 24 * i);
1622         const uint8_t sv_id = tvb_get_uint8(tvb, 45 + 24 * i);
1623         const uint8_t cn0 = tvb_get_uint8(tvb, 46 + 24 * i);
1624
1625         proto_tree *meas_tree = proto_tree_add_subtree_format(ubx_rxm_measx_tree,
1626                 tvb, 44 + 24 * i, 24, ett_ubx_rxm_measx_meas[i], NULL,
1627                 "%-7s / SV ID %3d / C/N0 %d dB-Hz",
1628                 val_to_str_const(gnss_id, UBX_GNSS_ID, "Unknown GNSS ID"),
1629                 sv_id, cn0);
1630
1631         proto_tree_add_item(meas_tree, hf_ubx_rxm_measx_gnssid,
1632                 tvb, 44 + 24 * i, 1, ENC_NA);
1633         proto_tree_add_item(meas_tree, hf_ubx_rxm_measx_svid,
1634                 tvb, 45 + 24 * i, 1, ENC_NA);
1635         proto_tree_add_item(meas_tree, hf_ubx_rxm_measx_cn0,
1636                 tvb, 46 + 24 * i, 1, ENC_NA);
1637         proto_tree_add_item(meas_tree, hf_ubx_rxm_measx_mpathindic,
1638                 tvb, 47 + 24 * i, 1, ENC_NA);
1639         proto_tree_add_item(meas_tree, hf_ubx_rxm_measx_dopplerms,
1640                 tvb, 48 + 24 * i, 4, ENC_LITTLE_ENDIAN);
1641         proto_tree_add_item(meas_tree, hf_ubx_rxm_measx_dopplerhz,
1642                 tvb, 52 + 24 * i, 4, ENC_LITTLE_ENDIAN);
1643         proto_tree_add_item(meas_tree, hf_ubx_rxm_measx_wholechips,
1644                 tvb, 56 + 24 * i, 2, ENC_LITTLE_ENDIAN);
1645         proto_tree_add_item(meas_tree, hf_ubx_rxm_measx_fracchips,
1646                 tvb, 58 + 24 * i, 2, ENC_LITTLE_ENDIAN);
1647         proto_tree_add_item(meas_tree, hf_ubx_rxm_measx_codephase,
1648                 tvb, 60 + 24 * i, 4, ENC_LITTLE_ENDIAN);
1649         proto_tree_add_item(meas_tree, hf_ubx_rxm_measx_intcodephase,
1650                 tvb, 64 + 24 * i, 1, ENC_NA);
1651         proto_tree_add_item(meas_tree, hf_ubx_rxm_measx_pseurangermserr,
1652                 tvb, 65 + 24 * i, 1, ENC_NA);
1653         proto_tree_add_item(meas_tree, hf_ubx_rxm_measx_reserved5,
1654                 tvb, 66 + 24 * i, 2, ENC_LITTLE_ENDIAN);
1655     }
1656
1657     return tvb_captured_length(tvb);
1658 }
1659
1660 /* Dissect UBX-RXM-RAWX message */
1661 static int dissect_ubx_rxm_rawx(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
1662     uint32_t i, nummeas;
1663
1664     col_set_str(pinfo->cinfo, COL_PROTOCOL, "UBX-RXM-RAWX");
1665     col_clear(pinfo->cinfo, COL_INFO);
1666
1667     nummeas = tvb_get_uint8(tvb, 11);
1668
1669     proto_item *ti = proto_tree_add_item(tree, hf_ubx_rxm_rawx,
1670             tvb, 0, 16 + nummeas * 32, ENC_NA);
1671     proto_tree *ubx_rxm_rawx_tree = proto_item_add_subtree(ti, ett_ubx_rxm_rawx);
1672
1673     proto_tree_add_item(ubx_rxm_rawx_tree, hf_ubx_rxm_rawx_rcvtow,
1674             tvb, 0, 8, ENC_LITTLE_ENDIAN);
1675     proto_tree_add_item(ubx_rxm_rawx_tree, hf_ubx_rxm_rawx_week,
1676             tvb, 8, 2, ENC_LITTLE_ENDIAN);
1677     proto_tree_add_item(ubx_rxm_rawx_tree, hf_ubx_rxm_rawx_leaps,
1678             tvb, 10, 1, ENC_NA);
1679     proto_tree_add_item(ubx_rxm_rawx_tree, hf_ubx_rxm_rawx_nummeas,
1680             tvb, 11, 1, ENC_NA);
1681     proto_tree_add_bitmask(ubx_rxm_rawx_tree, tvb, 12,
1682             hf_ubx_rxm_rawx_recstat, ett_ubx_rxm_rawx_recstat,
1683             ubx_rxm_rawx_recstat_fields, ENC_NA);
1684     proto_tree_add_item(ubx_rxm_rawx_tree, hf_ubx_rxm_rawx_version,
1685             tvb, 13, 1, ENC_NA);
1686     proto_tree_add_item(ubx_rxm_rawx_tree, hf_ubx_rxm_rawx_reserved1,
1687             tvb, 14, 2, ENC_LITTLE_ENDIAN);
1688
1689     for (i = 0; i < nummeas; i++) {
1690         const uint8_t gnss_id = tvb_get_uint8(tvb, 36 + 32 * i);
1691         const uint8_t sv_id = tvb_get_uint8(tvb, 37 + 32 * i);
1692         const uint8_t cn0 = tvb_get_uint8(tvb, 42 + 32 * i);
1693
1694         proto_tree *meas_tree = proto_tree_add_subtree_format(ubx_rxm_rawx_tree,
1695                 tvb, 16 + 32 * i, 32, ett_ubx_rxm_rawx_meas[i], NULL,
1696                 "%-7s / SV ID %3d / C/N0 %d dB-Hz",
1697                 val_to_str_const(gnss_id, UBX_GNSS_ID, "Unknown GNSS ID"),
1698                 sv_id, cn0);
1699
1700         proto_tree_add_item(meas_tree, hf_ubx_rxm_rawx_prmes,
1701                 tvb, 16 + 32 * i, 8, ENC_LITTLE_ENDIAN);
1702         proto_tree_add_item(meas_tree, hf_ubx_rxm_rawx_cpmes,
1703                 tvb, 24 + 32 * i, 8, ENC_LITTLE_ENDIAN);
1704         proto_tree_add_item(meas_tree, hf_ubx_rxm_rawx_domes,
1705                 tvb, 32 + 32 * i, 4, ENC_LITTLE_ENDIAN);
1706         proto_tree_add_item(meas_tree, hf_ubx_rxm_rawx_gnssid,
1707                 tvb, 36 + 32 * i, 1, ENC_NA);
1708         proto_tree_add_item(meas_tree, hf_ubx_rxm_rawx_svid,
1709                 tvb, 37 + 32 * i, 1, ENC_NA);
1710         proto_tree_add_item(meas_tree, hf_ubx_rxm_rawx_sigid,
1711                 tvb, 38 + 32 * i, 1, ENC_NA);
1712         proto_tree_add_item(meas_tree, hf_ubx_rxm_rawx_freqid,
1713                 tvb, 39 + 32 * i, 1, ENC_NA);
1714         proto_tree_add_item(meas_tree, hf_ubx_rxm_rawx_locktime,
1715                 tvb, 40 + 32 * i, 2, ENC_LITTLE_ENDIAN);
1716         proto_tree_add_item(meas_tree, hf_ubx_rxm_rawx_cn0,
1717                 tvb, 42 + 32 * i, 1, ENC_NA);
1718         proto_tree_add_item(meas_tree, hf_ubx_rxm_rawx_prstdev,
1719                 tvb, 43 + 32 * i, 1, ENC_NA);
1720         proto_tree_add_item(meas_tree, hf_ubx_rxm_rawx_cpstdev,
1721                 tvb, 44 + 32 * i, 1, ENC_NA);
1722         proto_tree_add_item(meas_tree, hf_ubx_rxm_rawx_dostdev,
1723                 tvb, 45 + 32 * i, 1, ENC_NA);
1724         proto_tree_add_bitmask(meas_tree, tvb, 46,
1725                 hf_ubx_rxm_rawx_trkstat, ett_ubx_rxm_rawx_trkstat,
1726                 ubx_rxm_rawx_trkstat_fields, ENC_NA);
1727         proto_tree_add_item(meas_tree, hf_ubx_rxm_rawx_reserved2,
1728                 tvb, 47 + 32 * i, 1, ENC_NA);
1729     }
1730
1731     return tvb_captured_length(tvb);
1732 }
1733
1734 /* Dissect UBX-RXM-SFRBX message */
1735 static int dissect_ubx_rxm_sfrbx(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
1736     tvbuff_t *next_tvb;
1737     uint8_t *buf;
1738     uint8_t i;
1739     uint32_t gnssid, numwords, version;
1740
1741     col_set_str(pinfo->cinfo, COL_PROTOCOL, "UBX-RXM-SFRBX");
1742     col_clear(pinfo->cinfo, COL_INFO);
1743
1744     // get length of the payload and protocol version
1745     numwords = tvb_get_uint8(tvb, 4);
1746     version = tvb_get_uint8(tvb, 6);
1747
1748     proto_item *ti = proto_tree_add_item(tree, hf_ubx_rxm_sfrbx,
1749             tvb, 0, 8 + numwords * 4, ENC_NA);
1750     proto_tree *ubx_rxm_sfrbx_tree = proto_item_add_subtree(ti, ett_ubx_rxm_sfrbx);
1751
1752     proto_tree_add_item_ret_uint(ubx_rxm_sfrbx_tree, hf_ubx_rxm_sfrbx_gnssid,
1753             tvb, 0, 1, ENC_NA, &gnssid);
1754     proto_tree_add_item(ubx_rxm_sfrbx_tree, hf_ubx_rxm_sfrbx_svid,
1755             tvb, 1, 1, ENC_NA);
1756     switch(version) {
1757         case 0x01: proto_tree_add_item(ubx_rxm_sfrbx_tree,
1758                            hf_ubx_rxm_sfrbx_reserved1, tvb, 2, 1, ENC_NA);
1759                    break;
1760         case 0x02: proto_tree_add_item(ubx_rxm_sfrbx_tree,
1761                            hf_ubx_rxm_sfrbx_sigid, tvb, 2, 1, ENC_NA);
1762                    break;
1763     }
1764     proto_tree_add_item(ubx_rxm_sfrbx_tree, hf_ubx_rxm_sfrbx_freqid,
1765             tvb, 3, 1, ENC_NA);
1766     proto_tree_add_item(ubx_rxm_sfrbx_tree, hf_ubx_rxm_sfrbx_numwords,
1767             tvb, 4, 1, ENC_NA);
1768     switch(version) {
1769         case 0x01: proto_tree_add_item(ubx_rxm_sfrbx_tree,
1770                            hf_ubx_rxm_sfrbx_reserved2, tvb, 5, 1, ENC_NA);
1771                    break;
1772         case 0x02: proto_tree_add_item(ubx_rxm_sfrbx_tree,
1773                            hf_ubx_rxm_sfrbx_chn, tvb, 5, 1, ENC_NA);
1774                    break;
1775     }
1776     proto_tree_add_item(ubx_rxm_sfrbx_tree, hf_ubx_rxm_sfrbx_version,
1777             tvb, 6, 1, ENC_NA);
1778     switch(version) {
1779         case 0x01: proto_tree_add_item(ubx_rxm_sfrbx_tree,
1780                            hf_ubx_rxm_sfrbx_reserved3, tvb, 7, 1, ENC_NA);
1781                    break;
1782         case 0x02: proto_tree_add_item(ubx_rxm_sfrbx_tree,
1783                            hf_ubx_rxm_sfrbx_reserved1, tvb, 7, 1, ENC_NA);
1784                    break;
1785     }
1786     proto_tree_add_item(ubx_rxm_sfrbx_tree, hf_ubx_rxm_sfrbx_dwrd,
1787             tvb, 8, numwords * 4, ENC_NA);
1788
1789     if (gnssid == GNSS_ID_GPS) {
1790         // send the GPS nav msg (preprocessed by UBX) to the next dissector
1791         next_tvb = tvb_new_subset_length(tvb, 8, 4 * numwords);
1792     }
1793     else {
1794         // UBX-RXM-SFRBX has the nav msg encoded in little endian. As this is not
1795         // convenient for dissection, map to big endian and add as new data source.
1796         buf = wmem_alloc(pinfo->pool, numwords * 4);
1797         for (i = 0; i < numwords; i++) {
1798             phton32(buf + 4 * i, tvb_get_uint32(tvb, 8 + i * 4, ENC_LITTLE_ENDIAN));
1799         }
1800         next_tvb = tvb_new_child_real_data(tvb, (uint8_t *)buf, numwords * 4, numwords * 4);
1801         add_new_data_source(pinfo, next_tvb, "GNSS navigation message");
1802     }
1803
1804     // send the nav msg to the next dissector
1805     if (!dissector_try_uint(ubx_gnssid_dissector_table, gnssid, next_tvb, pinfo, tree)) {
1806         call_data_dissector(next_tvb, pinfo, tree);
1807     }
1808
1809     return tvb_captured_length(tvb);
1810 }
1811
1812 void proto_register_ubx(void) {
1813     static hf_register_info hf[] = {
1814         {&hf_ubx_preamble,
1815             {"Preamble", "ubx.preamble",
1816                 FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL}},
1817         {&hf_ubx_msg_class_id,
1818             {"Msg Class & ID", "ubx.msg_class_id",
1819                 FT_UINT16, BASE_HEX, VALS(UBX_MSG_CLASS_ID), 0x0, NULL, HFILL}},
1820         {&hf_ubx_payload_len,
1821             {"Payload Length", "ubx.payload_len",
1822                 FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL}},
1823         {&hf_ubx_chksum,
1824             {"Checksum", "ubx.checksum",
1825                 FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL}},
1826
1827         // ACK-ACK
1828         {&hf_ubx_ack_ack,
1829             {"UBX-ACK-ACK", "ubx.ack.ack",
1830                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
1831         {&hf_ubx_ack_ack_msg_class_id,
1832             {"Msg Class & ID", "ubx.ack.ack.msg_class_id",
1833                 FT_UINT16, BASE_HEX, VALS(UBX_MSG_CLASS_ID), 0x0, NULL, HFILL}},
1834
1835         // ACK-NAK
1836         {&hf_ubx_ack_nak,
1837             {"UBX-ACK-NAK", "ubx.ack.nak",
1838                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
1839         {&hf_ubx_ack_nak_msg_class_id,
1840             {"Msg Class & ID", "ubx.ack.nak.msg_class_id",
1841                 FT_UINT16, BASE_HEX, VALS(UBX_MSG_CLASS_ID), 0x0, NULL, HFILL}},
1842
1843         // CFG-GNSS
1844         {&hf_ubx_cfg_gnss,
1845             {"UBX-CFG-GNSS", "ubx.cfg.gnss",
1846                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
1847         {&hf_ubx_cfg_gnss_version,
1848             {"Version", "ubx.cfg.gnss.version",
1849                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
1850         {&hf_ubx_cfg_gnss_numtrkchhw,
1851             {"Number of tracking channels available in hardware", "ubx.cfg.gnss.numtrkchhw",
1852                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
1853         {&hf_ubx_cfg_gnss_numtrkchuse,
1854             {"Number of tracking channels to use", "ubx.cfg.gnss.numtrkchuse",
1855                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
1856         {&hf_ubx_cfg_gnss_numconfigblocks,
1857             {"Number of configuration blocks following", "ubx.cfg.gnss.numconfigblocks",
1858                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
1859         {&hf_ubx_cfg_gnss_blk_gnssid,
1860             {"GNSS ID", "ubx.cfg.gnss.gnssid",
1861                 FT_UINT8, BASE_DEC, VALS(UBX_GNSS_ID), 0x0, NULL, HFILL}},
1862         {&hf_ubx_cfg_gnss_blk_restrkch,
1863             {"Number of reserved (minimum) tracking channels", "ubx.cfg.gnss.restrkch",
1864                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
1865         {&hf_ubx_cfg_gnss_blk_maxtrkch,
1866             {"Maximum number of tracking channels", "ubx.cfg.gnss.maxtrkch",
1867                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
1868         {&hf_ubx_cfg_gnss_blk_reserved1,
1869             {"Reserved", "ubx.cfg.gnss.reserved1",
1870                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
1871         {&hf_ubx_cfg_gnss_blk_enable,
1872             {"Enabled", "ubx.cfg.gnss.enabled",
1873                 FT_UINT32, BASE_HEX, NULL, 0x00000001, NULL, HFILL}},
1874         {&hf_ubx_cfg_gnss_blk_sigcfgmask,
1875             {"Signal configuration mask", "ubx.cfg.gnss.sigcfgmask",
1876                 FT_UINT32, BASE_HEX, NULL, 0x00ff0000, NULL, HFILL}},
1877         {&hf_ubx_cfg_gnss_blk_gps_sigcfgmask,
1878             {"Signal configuration mask", "ubx.cfg.gnss.sigcfgmask",
1879                 FT_UINT32, BASE_HEX, VALS(UBX_CFG_GNSS_GPS_SIGCFGMASK), 0x00ff0000, NULL, HFILL}},
1880         {&hf_ubx_cfg_gnss_blk_sbas_sigcfgmask,
1881             {"Signal configuration mask", "ubx.cfg.gnss.sigcfgmask",
1882                 FT_UINT32, BASE_HEX, VALS(UBX_CFG_GNSS_SBAS_SIGCFGMASK), 0x00ff0000, NULL, HFILL}},
1883         {&hf_ubx_cfg_gnss_blk_gal_sigcfgmask,
1884             {"Signal configuration mask", "ubx.cfg.gnss.sigcfgmask",
1885                 FT_UINT32, BASE_HEX, VALS(UBX_CFG_GNSS_GAL_SIGCFGMASK), 0x00ff0000, NULL, HFILL}},
1886         {&hf_ubx_cfg_gnss_blk_bds_sigcfgmask,
1887             {"Signal configuration mask", "ubx.cfg.gnss.sigcfgmask",
1888                 FT_UINT32, BASE_HEX, VALS(UBX_CFG_GNSS_BDS_SIGCFGMASK), 0x00ff0000, NULL, HFILL}},
1889         {&hf_ubx_cfg_gnss_blk_imes_sigcfgmask,
1890             {"Signal configuration mask", "ubx.cfg.gnss.sigcfgmask",
1891                 FT_UINT32, BASE_HEX, VALS(UBX_CFG_GNSS_IMES_SIGCFGMASK), 0x00ff0000, NULL, HFILL}},
1892         {&hf_ubx_cfg_gnss_blk_qzss_sigcfgmask,
1893             {"Signal configuration mask", "ubx.cfg.gnss.sigcfgmask",
1894                 FT_UINT32, BASE_HEX, VALS(UBX_CFG_GNSS_QZSS_SIGCFGMASK), 0x00ff0000, NULL, HFILL}},
1895         {&hf_ubx_cfg_gnss_blk_glo_sigcfgmask,
1896             {"Signal configuration mask", "ubx.cfg.gnss.sigcfgmask",
1897                 FT_UINT32, BASE_HEX, VALS(UBX_CFG_GNSS_GLO_SIGCFGMASK), 0x00ff0000, NULL, HFILL}},
1898
1899         // CFG-SBAS
1900         {&hf_ubx_cfg_sbas,
1901             {"UBX-CFG-SBAS", "ubx.cfg.sbas",
1902                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
1903         {&hf_ubx_cfg_sbas_mode,
1904             {"SBAS mode", "ubx.cfg.sbas.mode",
1905                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
1906         {&hf_ubx_cfg_sbas_mode_enabled,
1907             {"SBAS enabled", "ubx.cfg.sbas.mode.enabled",
1908                 FT_BOOLEAN, 8, NULL, 0x01, NULL, HFILL}},
1909         {&hf_ubx_cfg_sbas_mode_test,
1910             {"SBAS testbed", "ubx.cfg.sbas.mode.test",
1911                 FT_UINT8, BASE_HEX, VALS(UBX_SBAS_TESTBED), 0x02, NULL, HFILL}},
1912         {&hf_ubx_cfg_sbas_usage_range,
1913             {"Use SBAS GEOs as a ranging source (for navigation)", "ubx.cfg.sbas.usage.range",
1914                 FT_UINT8, BASE_HEX, NULL, 0x01, NULL, HFILL}},
1915         {&hf_ubx_cfg_sbas_usage_diffcorr,
1916             {"Use SBAS differential corrections", "ubx.cfg.sbas.usage.diffcorr",
1917                 FT_UINT8, BASE_HEX, NULL, 0x02, NULL, HFILL}},
1918         {&hf_ubx_cfg_sbas_usage_integrity,
1919             {"Use SBAS integrity information", "ubx.cfg.sbas.usage.integrity",
1920                 FT_UINT8, BASE_HEX, NULL, 0x04, NULL, HFILL}},
1921         {&hf_ubx_cfg_sbas_max_sbas,
1922             {"Maximum number of SBAS prioritized tracking channels to use", "ubx.cfg.sbas.maxsbas",
1923                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
1924         {&hf_ubx_cfg_sbas_scanmode_prn158,
1925             {"PRN 158", "ubx.cfg.sbas.scanmode.prn158",
1926                 FT_UINT8, BASE_HEX, NULL, 0x40, NULL, HFILL}},
1927         {&hf_ubx_cfg_sbas_scanmode_prn157,
1928             {"PRN 157", "ubx.cfg.sbas.scanmode.prn157",
1929                 FT_UINT8, BASE_HEX, NULL, 0x20, NULL, HFILL}},
1930         {&hf_ubx_cfg_sbas_scanmode_prn156,
1931             {"PRN 156", "ubx.cfg.sbas.scanmode.prn156",
1932                 FT_UINT8, BASE_HEX, NULL, 0x10, NULL, HFILL}},
1933         {&hf_ubx_cfg_sbas_scanmode_prn155,
1934             {"PRN 155", "ubx.cfg.sbas.scanmode.prn155",
1935                 FT_UINT8, BASE_HEX, NULL, 0x08, NULL, HFILL}},
1936         {&hf_ubx_cfg_sbas_scanmode_prn154,
1937             {"PRN 154", "ubx.cfg.sbas.scanmode.prn154",
1938                 FT_UINT8, BASE_HEX, NULL, 0x04, NULL, HFILL}},
1939         {&hf_ubx_cfg_sbas_scanmode_prn153,
1940             {"PRN 153", "ubx.cfg.sbas.scanmode.prn153",
1941                 FT_UINT8, BASE_HEX, NULL, 0x02, NULL, HFILL}},
1942         {&hf_ubx_cfg_sbas_scanmode_prn152,
1943             {"PRN 152", "ubx.cfg.sbas.scanmode.prn152",
1944                 FT_UINT8, BASE_HEX, NULL, 0x01, NULL, HFILL}},
1945         {&hf_ubx_cfg_sbas_scanmode_prn151,
1946             {"PRN 151", "ubx.cfg.sbas.scanmode.prn151",
1947                 FT_UINT32, BASE_HEX, NULL, 0x80000000, NULL, HFILL}},
1948         {&hf_ubx_cfg_sbas_scanmode_prn150,
1949             {"PRN 150", "ubx.cfg.sbas.scanmode.prn150",
1950                 FT_UINT32, BASE_HEX, NULL, 0x40000000, NULL, HFILL}},
1951         {&hf_ubx_cfg_sbas_scanmode_prn149,
1952             {"PRN 149", "ubx.cfg.sbas.scanmode.prn149",
1953                 FT_UINT32, BASE_HEX, NULL, 0x20000000, NULL, HFILL}},
1954         {&hf_ubx_cfg_sbas_scanmode_prn148,
1955             {"PRN 148", "ubx.cfg.sbas.scanmode.prn148",
1956                 FT_UINT32, BASE_HEX, NULL, 0x10000000, NULL, HFILL}},
1957         {&hf_ubx_cfg_sbas_scanmode_prn147,
1958             {"PRN 147", "ubx.cfg.sbas.scanmode.prn147",
1959                 FT_UINT32, BASE_HEX, NULL, 0x08000000, NULL, HFILL}},
1960         {&hf_ubx_cfg_sbas_scanmode_prn146,
1961             {"PRN 146", "ubx.cfg.sbas.scanmode.prn146",
1962                 FT_UINT32, BASE_HEX, NULL, 0x04000000, NULL, HFILL}},
1963         {&hf_ubx_cfg_sbas_scanmode_prn145,
1964             {"PRN 145", "ubx.cfg.sbas.scanmode.prn145",
1965                 FT_UINT32, BASE_HEX, NULL, 0x02000000, NULL, HFILL}},
1966         {&hf_ubx_cfg_sbas_scanmode_prn144,
1967             {"PRN 144", "ubx.cfg.sbas.scanmode.prn144",
1968                 FT_UINT32, BASE_HEX, NULL, 0x01000000, NULL, HFILL}},
1969         {&hf_ubx_cfg_sbas_scanmode_prn143,
1970             {"PRN 143", "ubx.cfg.sbas.scanmode.prn143",
1971                 FT_UINT32, BASE_HEX, NULL, 0x00800000, NULL, HFILL}},
1972         {&hf_ubx_cfg_sbas_scanmode_prn142,
1973             {"PRN 142", "ubx.cfg.sbas.scanmode.prn142",
1974                 FT_UINT32, BASE_HEX, NULL, 0x00400000, NULL, HFILL}},
1975         {&hf_ubx_cfg_sbas_scanmode_prn141,
1976             {"PRN 141", "ubx.cfg.sbas.scanmode.prn141",
1977                 FT_UINT32, BASE_HEX, NULL, 0x00200000, NULL, HFILL}},
1978         {&hf_ubx_cfg_sbas_scanmode_prn140,
1979             {"PRN 140", "ubx.cfg.sbas.scanmode.prn140",
1980                 FT_UINT32, BASE_HEX, NULL, 0x00100000, NULL, HFILL}},
1981         {&hf_ubx_cfg_sbas_scanmode_prn139,
1982             {"PRN 139", "ubx.cfg.sbas.scanmode.prn139",
1983                 FT_UINT32, BASE_HEX, NULL, 0x00080000, NULL, HFILL}},
1984         {&hf_ubx_cfg_sbas_scanmode_prn138,
1985             {"PRN 138", "ubx.cfg.sbas.scanmode.prn138",
1986                 FT_UINT32, BASE_HEX, NULL, 0x00040000, NULL, HFILL}},
1987         {&hf_ubx_cfg_sbas_scanmode_prn137,
1988             {"PRN 137", "ubx.cfg.sbas.scanmode.prn137",
1989                 FT_UINT32, BASE_HEX, NULL, 0x00020000, NULL, HFILL}},
1990         {&hf_ubx_cfg_sbas_scanmode_prn136,
1991             {"PRN 136", "ubx.cfg.sbas.scanmode.prn136",
1992                 FT_UINT32, BASE_HEX, NULL, 0x00010000, NULL, HFILL}},
1993         {&hf_ubx_cfg_sbas_scanmode_prn135,
1994             {"PRN 135", "ubx.cfg.sbas.scanmode.prn135",
1995                 FT_UINT32, BASE_HEX, NULL, 0x00008000, NULL, HFILL}},
1996         {&hf_ubx_cfg_sbas_scanmode_prn134,
1997             {"PRN 134", "ubx.cfg.sbas.scanmode.prn134",
1998                 FT_UINT32, BASE_HEX, NULL, 0x00004000, NULL, HFILL}},
1999         {&hf_ubx_cfg_sbas_scanmode_prn133,
2000             {"PRN 133", "ubx.cfg.sbas.scanmode.prn133",
2001                 FT_UINT32, BASE_HEX, NULL, 0x00002000, NULL, HFILL}},
2002         {&hf_ubx_cfg_sbas_scanmode_prn132,
2003             {"PRN 132", "ubx.cfg.sbas.scanmode.prn132",
2004                 FT_UINT32, BASE_HEX, NULL, 0x00001000, NULL, HFILL}},
2005         {&hf_ubx_cfg_sbas_scanmode_prn131,
2006             {"PRN 131", "ubx.cfg.sbas.scanmode.prn131",
2007                 FT_UINT32, BASE_HEX, NULL, 0x00000800, NULL, HFILL}},
2008         {&hf_ubx_cfg_sbas_scanmode_prn130,
2009             {"PRN 130", "ubx.cfg.sbas.scanmode.prn130",
2010                 FT_UINT32, BASE_HEX, NULL, 0x00000400, NULL, HFILL}},
2011         {&hf_ubx_cfg_sbas_scanmode_prn129,
2012             {"PRN 129", "ubx.cfg.sbas.scanmode.prn129",
2013                 FT_UINT32, BASE_HEX, NULL, 0x00000200, NULL, HFILL}},
2014         {&hf_ubx_cfg_sbas_scanmode_prn128,
2015             {"PRN 128", "ubx.cfg.sbas.scanmode.prn128",
2016                 FT_UINT32, BASE_HEX, NULL, 0x00000100, NULL, HFILL}},
2017         {&hf_ubx_cfg_sbas_scanmode_prn127,
2018             {"PRN 127", "ubx.cfg.sbas.scanmode.prn127",
2019                 FT_UINT32, BASE_HEX, NULL, 0x00000080, NULL, HFILL}},
2020         {&hf_ubx_cfg_sbas_scanmode_prn126,
2021             {"PRN 126", "ubx.cfg.sbas.scanmode.prn126",
2022                 FT_UINT32, BASE_HEX, NULL, 0x00000040, NULL, HFILL}},
2023         {&hf_ubx_cfg_sbas_scanmode_prn125,
2024             {"PRN 125", "ubx.cfg.sbas.scanmode.prn125",
2025                 FT_UINT32, BASE_HEX, NULL, 0x00000020, NULL, HFILL}},
2026         {&hf_ubx_cfg_sbas_scanmode_prn124,
2027             {"PRN 124", "ubx.cfg.sbas.scanmode.prn124",
2028                 FT_UINT32, BASE_HEX, NULL, 0x00000010, NULL, HFILL}},
2029         {&hf_ubx_cfg_sbas_scanmode_prn123,
2030             {"PRN 123", "ubx.cfg.sbas.scanmode.prn123",
2031                 FT_UINT32, BASE_HEX, NULL, 0x00000008, NULL, HFILL}},
2032         {&hf_ubx_cfg_sbas_scanmode_prn122,
2033             {"PRN 122", "ubx.cfg.sbas.scanmode.prn122",
2034                 FT_UINT32, BASE_HEX, NULL, 0x00000004, NULL, HFILL}},
2035         {&hf_ubx_cfg_sbas_scanmode_prn121,
2036             {"PRN 121", "ubx.cfg.sbas.scanmode.prn121",
2037                 FT_UINT32, BASE_HEX, NULL, 0x00000002, NULL, HFILL}},
2038         {&hf_ubx_cfg_sbas_scanmode_prn120,
2039             {"PRN 120", "ubx.cfg.sbas.scanmode.prn120",
2040                 FT_UINT32, BASE_HEX, NULL, 0x00000001, NULL, HFILL}},
2041
2042         // NAV-DOP
2043         {&hf_ubx_nav_dop,
2044             {"UBX-NAV-DOP", "ubx.nav.dop",
2045                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
2046         {&hf_ubx_nav_dop_itow,
2047             {"iTOW", "ubx.nav.dop.itow",
2048                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2049         {&hf_ubx_nav_dop_gdop,
2050             {"Geometric DOP", "ubx.nav.dop.gdop",
2051                 FT_UINT16, BASE_CUSTOM, CF_FUNC(&fmt_dop), 0x0, NULL, HFILL}},
2052         {&hf_ubx_nav_dop_pdop,
2053             {"Position DOP", "ubx.nav.dop.pdop",
2054                 FT_UINT16, BASE_CUSTOM, CF_FUNC(&fmt_dop), 0x0, NULL, HFILL}},
2055         {&hf_ubx_nav_dop_tdop,
2056             {"Time DOP", "ubx.nav.dop.tdop",
2057                 FT_UINT16, BASE_CUSTOM, CF_FUNC(&fmt_dop), 0x0, NULL, HFILL}},
2058         {&hf_ubx_nav_dop_vdop,
2059             {"Vertical DOP", "ubx.nav.dop.vdop",
2060                 FT_UINT16, BASE_CUSTOM, CF_FUNC(&fmt_dop), 0x0, NULL, HFILL}},
2061         {&hf_ubx_nav_dop_hdop,
2062             {"Horizontal DOP", "ubx.nav.dop.hdop",
2063                 FT_UINT16, BASE_CUSTOM, CF_FUNC(&fmt_dop), 0x0, NULL, HFILL}},
2064         {&hf_ubx_nav_dop_ndop,
2065             {"Northing DOP", "ubx.nav.dop.ndop",
2066                 FT_UINT16, BASE_CUSTOM, CF_FUNC(&fmt_dop), 0x0, NULL, HFILL}},
2067         {&hf_ubx_nav_dop_edop,
2068             {"Easting DOP", "ubx.nav.dop.edop",
2069                 FT_UINT16, BASE_CUSTOM, CF_FUNC(&fmt_dop), 0x0, NULL, HFILL}},
2070
2071         // NAV-EOE
2072         {&hf_ubx_nav_eoe,
2073             {"UBX-NAV-EOE", "ubx.nav.eoe",
2074                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
2075         {&hf_ubx_nav_eoe_itow,
2076             {"iTOW", "ubx.nav.eoe.itow",
2077                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2078
2079         // NAV-ODO
2080         {&hf_ubx_nav_odo,
2081             {"UBX-NAV-ODO", "ubx.nav.odo",
2082                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
2083         {&hf_ubx_nav_odo_version,
2084             {"Version", "ubx.nav.odo.version",
2085                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2086         {&hf_ubx_nav_odo_reserved1,
2087             {"Reserved", "ubx.nav.odo.reserved1",
2088                 FT_UINT24, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2089         {&hf_ubx_nav_odo_itow,
2090             {"iTOW", "ubx.nav.odo.itow",
2091                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2092         {&hf_ubx_nav_odo_distance,
2093             {"Ground distance since last reset", "ubx.nav.odo.distance",
2094                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_meter_meters), 0x0, NULL, HFILL}},
2095         {&hf_ubx_nav_odo_totaldistance,
2096             {"Total cumulative ground distance", "ubx.nav.odo.totaldistance",
2097                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_meter_meters), 0x0, NULL, HFILL}},
2098         {&hf_ubx_nav_odo_distancestd,
2099             {"Ground distance accuracy (1-sigma)", "ubx.nav.odo.distancestd",
2100                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_meter_meters), 0x0, NULL, HFILL}},
2101
2102         // NAV-POSECEF
2103         {&hf_ubx_nav_posecef,
2104             {"UBX-NAV-POSECEF", "ubx.nav.posecef",
2105                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
2106         {&hf_ubx_nav_posecef_itow,
2107             {"iTOW", "ubx.nav.posecef.itow",
2108                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2109         {&hf_ubx_nav_posecef_ecefx,
2110             {"ECEF X coordinate", "ubx.nav.posecef.ecefx",
2111                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_centimeters), 0x0, NULL, HFILL}},
2112         {&hf_ubx_nav_posecef_ecefy,
2113             {"ECEF Y coordinate", "ubx.nav.posecef.ecefy",
2114                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_centimeters), 0x0, NULL, HFILL}},
2115         {&hf_ubx_nav_posecef_ecefz,
2116             {"ECEF Z coordinate", "ubx.nav.posecef.ecefz",
2117                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_centimeters), 0x0, NULL, HFILL}},
2118         {&hf_ubx_nav_posecef_pacc,
2119             {"Position accuracy estimate", "ubx.nav.posecef.pacc",
2120                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_centimeters), 0x0, NULL, HFILL}},
2121
2122         // NAV-PVT
2123         {&hf_ubx_nav_pvt,
2124             {"UBX-NAV-PVT", "ubx.nav.pvt",
2125                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
2126         {&hf_ubx_nav_pvt_itow,
2127             {"iTOW", "ubx.nav.pvt.itow",
2128                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2129         {&hf_ubx_nav_pvt_year,
2130             {"Year", "ubx.nav.pvt.year",
2131                 FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2132         {&hf_ubx_nav_pvt_month,
2133             {"Month", "ubx.nav.pvt.month",
2134                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2135         {&hf_ubx_nav_pvt_day,
2136             {"Day", "ubx.nav.pvt.day",
2137                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2138         {&hf_ubx_nav_pvt_hour,
2139             {"Hour", "ubx.nav.pvt.hour",
2140                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2141         {&hf_ubx_nav_pvt_min,
2142             {"Minute", "ubx.nav.pvt.min",
2143                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2144         {&hf_ubx_nav_pvt_sec,
2145             {"Seconds", "ubx.nav.pvt.sec",
2146                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2147         {&hf_ubx_nav_pvt_valid,
2148             {"Validity flags", "ubx.nav.pvt.valid",
2149                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2150         {&hf_ubx_nav_pvt_validmag,
2151             {"Valid magnetic declination", "ubx.nav.pvt.valid.validmag",
2152                 FT_BOOLEAN, 8, NULL, 0x08, NULL, HFILL}},
2153         {&hf_ubx_nav_pvt_fullyresolved,
2154             {"UTC time of day fully resolved", "ubx.nav.pvt.valid.fullyresolved",
2155                 FT_BOOLEAN, 8, NULL, 0x04, NULL, HFILL}},
2156         {&hf_ubx_nav_pvt_validtime,
2157             {"valid UTC time of day", "ubx.nav.pvt.valid.validtime",
2158                 FT_BOOLEAN, 8, NULL, 0x02, NULL, HFILL}},
2159         {&hf_ubx_nav_pvt_validdate,
2160             {"valid UTC date", "ubx.nav.pvt.valid.validdate",
2161                 FT_BOOLEAN, 8, NULL, 0x01, NULL, HFILL}},
2162         {&hf_ubx_nav_pvt_tacc,
2163             {"Time accuracy estimate", "ubx.nav.pvt.tacc",
2164                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_nanoseconds), 0x0, NULL, HFILL}},
2165         {&hf_ubx_nav_pvt_nano,
2166             {"UTC fraction of second", "ubx.nav.pvt.nano",
2167                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_nanoseconds), 0x0, NULL, HFILL}},
2168         {&hf_ubx_nav_pvt_fixtype,
2169             {"GNSS fix type", "ubx.nav.pvt.fixtype",
2170                 FT_UINT8, BASE_DEC, VALS(UBX_GNSS_FIX_TYPE), 0x0, NULL, HFILL}},
2171         {&hf_ubx_nav_pvt_flags,
2172             {"Fix status flags", "ubx.nav.pvt.flags",
2173                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2174         {&hf_ubx_nav_pvt_headvehvalid,
2175             {"heading of vehicle is valid", "ubx.nav.pvt.flags.headvehvalid",
2176                 FT_BOOLEAN, 8, NULL, 0x20, NULL, HFILL}},
2177         {&hf_ubx_nav_pvt_psmstate,
2178             {"PSM state", "ubx.nav.pvt.flags.psmstate",
2179                 FT_UINT8, BASE_DEC, NULL, 0x1c, NULL, HFILL}},
2180         {&hf_ubx_nav_pvt_diffsoln,
2181             {"differential corrections were applied", "ubx.nav.pvt.flags.diffsoln",
2182                 FT_BOOLEAN, 8, NULL, 0x02, NULL, HFILL}},
2183         {&hf_ubx_nav_pvt_gnssfixok,
2184             {"valid fix", "ubx.nav.pvt.flags.gnssfixok",
2185                 FT_BOOLEAN, 8, NULL, 0x01, NULL, HFILL}},
2186         {&hf_ubx_nav_pvt_flags2,
2187             {"Additional flags", "ubx.nav.pvt.flags2",
2188                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2189         {&hf_ubx_nav_pvt_confirmedtime,
2190             {"UTC time of day could be confirmed", "ubx.nav.pvt.flags2.confirmedtime",
2191                 FT_BOOLEAN, 8, NULL, 0x80, NULL, HFILL}},
2192         {&hf_ubx_nav_pvt_confirmeddate,
2193             {"UTC date could be validated", "ubx.nav.pvt.flags2.confirmeddate",
2194                 FT_BOOLEAN, 8, NULL, 0x40, NULL, HFILL}},
2195         {&hf_ubx_nav_pvt_confirmedavai,
2196             {"information about UTC date and time of day validity confirmation is available", "ubx.nav.pvt.flags2.confirmedavai",
2197                 FT_BOOLEAN, 8, NULL, 0x20, NULL, HFILL}},
2198         {&hf_ubx_nav_pvt_numsv,
2199             {"Number of satellite vehicles used in Nav solution", "ubx.nav.pvt.numsv",
2200                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2201         {&hf_ubx_nav_pvt_lon,
2202             {"Longitude", "ubx.nav.pvt.lon",
2203                 FT_INT32, BASE_CUSTOM, CF_FUNC(&fmt_lat_lon), 0x0, NULL, HFILL}},
2204         {&hf_ubx_nav_pvt_lat,
2205             {"Latitude", "ubx.nav.pvt.lat",
2206                 FT_INT32, BASE_CUSTOM, CF_FUNC(&fmt_lat_lon), 0x0, NULL, HFILL}},
2207         {&hf_ubx_nav_pvt_height,
2208             {"Height above ellipsoid", "ubx.nav.pvt.height",
2209                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_millimeters), 0x0, NULL, HFILL}},
2210         {&hf_ubx_nav_pvt_hmsl,
2211             {"Height above mean sea level", "ubx.nav.pvt.hmsl",
2212                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_millimeters), 0x0, NULL, HFILL}},
2213         {&hf_ubx_nav_pvt_hacc,
2214             {"Horizontal accuracy estimate", "ubx.nav.pvt.hacc",
2215                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_millimeters), 0x0, NULL, HFILL}},
2216         {&hf_ubx_nav_pvt_vacc,
2217             {"Vertical accuracy estimate", "ubx.nav.pvt.vacc",
2218                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_millimeters), 0x0, NULL, HFILL}},
2219         {&hf_ubx_nav_pvt_veln,
2220             {"NED north velocity", "ubx.nav.pvt.veln",
2221                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_mm_s), 0x0, NULL, HFILL}},
2222         {&hf_ubx_nav_pvt_vele,
2223             {"NED east velocity", "ubx.nav.pvt.vele",
2224                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_mm_s), 0x0, NULL, HFILL}},
2225         {&hf_ubx_nav_pvt_veld,
2226             {"NED down velocity", "ubx.nav.pvt.veld",
2227                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_mm_s), 0x0, NULL, HFILL}},
2228         {&hf_ubx_nav_pvt_gspeed,
2229             {"Ground speed (2-D)", "ubx.nav.pvt.gspeed",
2230                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_mm_s), 0x0, NULL, HFILL}},
2231         {&hf_ubx_nav_pvt_headmot,
2232             {"Heading of motion (2-D)", "ubx.nav.pvt.headmot",
2233                 FT_INT32, BASE_CUSTOM, CF_FUNC(&fmt_heading), 0x0, NULL, HFILL}},
2234         {&hf_ubx_nav_pvt_sacc,
2235             {"Speed accuracy estimate", "ubx.nav.pvt.sacc",
2236                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_mm_s), 0x0, NULL, HFILL}},
2237         {&hf_ubx_nav_pvt_headacc,
2238             {"Heading accuracy estimate", "ubx.nav.pvt.headacc",
2239                 FT_UINT32, BASE_CUSTOM, CF_FUNC(&fmt_heading_acc), 0x0, NULL, HFILL}},
2240         {&hf_ubx_nav_pvt_pdop,
2241             {"Position DOP", "ubx.nav.pvt.pdop",
2242                 FT_UINT16, BASE_CUSTOM, CF_FUNC(&fmt_dop), 0x0, NULL, HFILL}},
2243         {&hf_ubx_nav_pvt_lastcorrectionage,
2244             {"Age of the most recently received differential correction", "ubx.nav.pvt.lastcorrectionage",
2245                 FT_UINT16, BASE_DEC, VALS(UBX_LAST_CORRECTION_AGE), 0x001e, NULL, HFILL}},
2246         {&hf_ubx_nav_pvt_invalidllh,
2247             {"Invalid lon, lat, height, and hMSL", "ubx.nav.pvt.invalidllh",
2248                 FT_BOOLEAN, 16, NULL, 0x0001, NULL, HFILL}},
2249         {&hf_ubx_nav_pvt_reserved1,
2250             {"Reserved 1", "ubx.nav.pvt.reserved1",
2251                 FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2252         {&hf_ubx_nav_pvt_headveh,
2253             {"Heading of vehicle (2-D)", "ubx.nav.pvt.headveh",
2254                 FT_INT32, BASE_CUSTOM, CF_FUNC(&fmt_heading), 0x0, NULL, HFILL}},
2255         {&hf_ubx_nav_pvt_magdec,
2256             {"Magnetic declination", "ubx.nav.pvt.magdec",
2257                 FT_INT16, BASE_CUSTOM, CF_FUNC(&fmt_decl), 0x0, NULL, HFILL}},
2258         {&hf_ubx_nav_pvt_magacc,
2259             {"Magnetic declination accuracy", "ubx.nav.pvt.magacc",
2260                 FT_UINT16, BASE_CUSTOM, CF_FUNC(&fmt_decl_acc), 0x0, NULL, HFILL}},
2261
2262         // NAV-SAT
2263         {&hf_ubx_nav_sat,
2264             {"UBX-NAV-SAT", "ubx.nav.sat",
2265                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
2266         {&hf_ubx_nav_sat_itow,
2267             {"iTOW", "ubx.nav.sat.itow",
2268                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2269         {&hf_ubx_nav_sat_version,
2270             {"Version", "ubx.nav.sat.version",
2271                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2272         {&hf_ubx_nav_sat_num_svs,
2273             {"Number of satellites", "ubx.nav.sat.num_svs",
2274                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2275         {&hf_ubx_nav_sat_reserved1,
2276             {"Reserved", "ubx.nav.sat.reserved1",
2277                 FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2278         {&hf_ubx_nav_sat_gnss_id,
2279             {"GNSS ID", "ubx.nav.sat.gnss_id",
2280                 FT_UINT8, BASE_DEC, VALS(UBX_GNSS_ID), 0x0, NULL, HFILL}},
2281         {&hf_ubx_nav_sat_sv_id,
2282             {"SV ID", "ubx.nav.sat.sv_id",
2283                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2284         {&hf_ubx_nav_sat_cn0,
2285             {"C/N0", "ubx.nav.sat.cn0",
2286                 FT_UINT8, BASE_DEC|BASE_UNIT_STRING, UNS(&units_dbhz), 0x0, NULL, HFILL}},
2287         {&hf_ubx_nav_sat_elev,
2288             {"Elevation", "ubx.nav.sat.elev",
2289                 FT_INT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2290         {&hf_ubx_nav_sat_azim,
2291             {"Azimuth", "ubx.nav.sat.azim",
2292                 FT_INT16, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2293         {&hf_ubx_nav_sat_pr_res,
2294             {"Pseudorange residual", "ubx.nav.sat.pr_res",
2295                 FT_INT16, BASE_CUSTOM, CF_FUNC(&fmt_pr_res), 0x0, NULL, HFILL}},
2296         {&hf_ubx_nav_sat_flags,
2297             {"Bitmask", "ubx.nav.sat.flags",
2298                 FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2299         {&hf_ubx_nav_sat_quality_ind,
2300             {"Signal quality indicator", "ubx.nav.sat.flags.quality_ind",
2301                 FT_UINT32, BASE_HEX, VALS(UBX_SIGNAL_QUALITY_INDICATOR), 0x00000007, NULL, HFILL}},
2302         {&hf_ubx_nav_sat_sv_used,
2303             {"Signal used for navigation", "ubx.nav.sat.flags.sv_used",
2304                 FT_UINT32, BASE_HEX, NULL, 0x00000008, NULL, HFILL}},
2305         {&hf_ubx_nav_sat_health,
2306             {"Signal health", "ubx.nav.sat.flags.health",
2307                 FT_UINT32, BASE_HEX, VALS(UBX_SIGNAL_HEALTH), 0x00000030, NULL, HFILL}},
2308         {&hf_ubx_nav_sat_diff_corr,
2309             {"Differential correction available", "ubx.nav.sat.flags.diff_corr",
2310                 FT_UINT32, BASE_HEX, NULL, 0x00000040, NULL, HFILL}},
2311         {&hf_ubx_nav_sat_smoothed,
2312             {"Carrier smoothed pseudorange used", "ubx.nav.sat.flags.smoothed",
2313                 FT_UINT32, BASE_HEX, NULL, 0x00000080, NULL, HFILL}},
2314         {&hf_ubx_nav_sat_orbit_src,
2315             {"Orbit source", "ubx.nav.sat.flags.orbit_src",
2316                 FT_UINT32, BASE_HEX, VALS(UBX_ORBIT_SOURCE), 0x00000700, NULL, HFILL}},
2317         {&hf_ubx_nav_sat_eph_avail,
2318             {"Ephemeris available", "ubx.nav.sat.flags.eph_avail",
2319                 FT_UINT32, BASE_HEX, NULL, 0x00000800, NULL, HFILL}},
2320         {&hf_ubx_nav_sat_alm_avail,
2321             {"Almanac available", "ubx.nav.sat.flags.alm_avail",
2322                 FT_UINT32, BASE_HEX, NULL, 0x00001000, NULL, HFILL}},
2323         {&hf_ubx_nav_sat_ano_avail,
2324             {"AssistNow Offline data available", "ubx.nav.sat.flags.ano_avail",
2325                 FT_UINT32, BASE_HEX, NULL, 0x00002000, NULL, HFILL}},
2326         {&hf_ubx_nav_sat_aop_avail,
2327             {"AssistNow Autonomous data available", "ubx.nav.sat.flags.aop_avail",
2328                 FT_UINT32, BASE_HEX, NULL, 0x00004000, NULL, HFILL}},
2329         {&hf_ubx_nav_sat_sbas_corr_used,
2330             {"SBAS corrections used", "ubx.nav.sat.flags.sbas_corr_used",
2331                 FT_UINT32, BASE_HEX, NULL, 0x00010000, NULL, HFILL}},
2332         {&hf_ubx_nav_sat_rtcm_corr_used,
2333             {"RTCM corrections used", "ubx.nav.sat.flags.rtcm_corr_used",
2334                 FT_UINT32, BASE_HEX, NULL, 0x00020000, NULL, HFILL}},
2335         {&hf_ubx_nav_sat_slas_corr_used,
2336             {"QZSS SLAS corrections used", "ubx.nav.sat.flags.slas_corr_used",
2337                 FT_UINT32, BASE_HEX, NULL, 0x00040000, NULL, HFILL}},
2338         {&hf_ubx_nav_sat_spartn_corr_used,
2339             {"SPARTN corrections used", "ubx.nav.sat.flags.spartn_corr_used",
2340                 FT_UINT32, BASE_HEX, NULL, 0x00080000, NULL, HFILL}},
2341         {&hf_ubx_nav_sat_pr_corr_used,
2342             {"Pseudorange corrections used", "ubx.nav.sat.flags.pr_corr_used",
2343                 FT_UINT32, BASE_HEX, NULL, 0x00100000, NULL, HFILL}},
2344         {&hf_ubx_nav_sat_cr_corr_used,
2345             {"Carrier range corrections used", "ubx.nav.sat.flags.cr_corr_used",
2346                 FT_UINT32, BASE_HEX, NULL, 0x00200000, NULL, HFILL}},
2347         {&hf_ubx_nav_sat_do_corr_used,
2348             {"Range rate (Doppler) corrections used", "ubx.nav.sat.flags.do_corr_used",
2349                 FT_UINT32, BASE_HEX, NULL, 0x00400000, NULL, HFILL}},
2350
2351         // NAV-SBAS
2352         {&hf_ubx_nav_sbas,
2353             {"UBX-NAV-SBAS", "ubx.nav.sbas",
2354                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
2355         {&hf_ubx_nav_sbas_itow,
2356             {"iTOW", "ubx.nav.sbas.itow",
2357                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2358         {&hf_ubx_nav_sbas_geo,
2359             {"GEO PRN", "ubx.nav.sbas.geo",
2360                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2361         {&hf_ubx_nav_sbas_mode,
2362             {"SBAS Mode", "ubx.nav.sbas.mode",
2363                 FT_UINT8, BASE_DEC, VALS(UBX_SBAS_MODE), 0x0, NULL, HFILL}},
2364         {&hf_ubx_nav_sbas_sys,
2365             {"SBAS System", "ubx.nav.sbas.sys",
2366                 FT_INT8, BASE_DEC, VALS(UBX_SBAS_SYSTEM), 0x0, NULL, HFILL}},
2367         {&hf_ubx_nav_sbas_service,
2368             {"SBAS Services available", "ubx.nav.sbas.service",
2369                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2370         {&hf_ubx_nav_sbas_service_ranging,
2371             {"GEO may be used as ranging source", "ubx.nav.sbas.service.ranging",
2372                 FT_BOOLEAN, 8, NULL, 0x01, NULL, HFILL}},
2373         {&hf_ubx_nav_sbas_service_corrections,
2374             {"GEO is providing correction data", "ubx.nav.sbas.service.corrections",
2375                 FT_BOOLEAN, 8, NULL, 0x02, NULL, HFILL}},
2376         {&hf_ubx_nav_sbas_service_integrity,
2377             {"GEO is providing integrity", "ubx.nav.sbas.service.integrity",
2378                 FT_BOOLEAN, 8, NULL, 0x04, NULL, HFILL}},
2379         {&hf_ubx_nav_sbas_service_testmode,
2380             {"GEO is in test mode", "ubx.nav.sbas.service.testmode",
2381                 FT_BOOLEAN, 8, NULL, 0x08, NULL, HFILL}},
2382         {&hf_ubx_nav_sbas_service_bad,
2383             {"Problem with signal or broadcast data indicated", "ubx.nav.sbas.service.bad",
2384                 FT_BOOLEAN, 8, NULL, 0x10, NULL, HFILL}},
2385         {&hf_ubx_nav_sbas_cnt,
2386             {"Number of SV data following", "ubx.nav.sbas.cnt",
2387                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2388         {&hf_ubx_nav_sbas_reserved1,
2389             {"Reserved", "ubx.nav.sbas.reserved1",
2390                 FT_UINT24, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2391         {&hf_ubx_nav_sbas_sv_id,
2392             {"SV ID", "ubx.nav.sbas.sv_id",
2393                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2394         {&hf_ubx_nav_sbas_flags,
2395             {"Flags", "ubx.nav.sbas.flags",
2396                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2397         {&hf_ubx_nav_sbas_udre,
2398             {"Monitoring status", "ubx.nav.sbas.udre",
2399                 FT_UINT8, BASE_DEC, VALS(UDREI_EVALUATION), 0x0, NULL, HFILL}},
2400         {&hf_ubx_nav_sbas_sv_sys,
2401             {"System", "ubx.nav.sbas.sv_sys",
2402                 FT_INT8, BASE_DEC, VALS(UBX_SBAS_SYSTEM), 0x0, NULL, HFILL}},
2403         {&hf_ubx_nav_sbas_sv_service,
2404             {"Service", "ubx.nav.sbas.sv_service",
2405                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2406         {&hf_ubx_nav_sbas_reserved2,
2407             {"Reserved", "ubx.nav.sbas.reserved2",
2408                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2409         {&hf_ubx_nav_sbas_prc,
2410             {"Pseudo Range correction", "ubx.nav.sbas.prc",
2411                 FT_INT16, BASE_DEC|BASE_UNIT_STRING, UNS(&units_centimeter_centimeters), 0x0, NULL, HFILL}},
2412         {&hf_ubx_nav_sbas_reserved3,
2413             {"Reserved", "ubx.nav.sbas.reserved3",
2414                 FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2415         {&hf_ubx_nav_sbas_ic,
2416             {"Ionosphere correction", "ubx.nav.sbas.ic",
2417                 FT_INT16, BASE_DEC|BASE_UNIT_STRING, UNS(&units_centimeter_centimeters), 0x0, NULL, HFILL}},
2418
2419         // NAV-TIMEGPS
2420         {&hf_ubx_nav_timegps,
2421             {"UBX-NAV-TIMEGPS", "ubx.nav.timegps",
2422                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
2423         {&hf_ubx_nav_timegps_itow,
2424             {"iTOW", "ubx.nav.timegps.itow",
2425                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2426         {&hf_ubx_nav_timegps_ftow,
2427             {"fTOW", "ubx.nav.timegps.ftow",
2428                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_nanoseconds), 0x0, NULL, HFILL}},
2429         {&hf_ubx_nav_timegps_week,
2430             {"GPS week", "ubx.nav.timegps.week",
2431                 FT_INT16, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2432         {&hf_ubx_nav_timegps_leaps,
2433             {"GPS leap seconds", "ubx.nav.timegps.leaps",
2434                 FT_INT8, BASE_DEC|BASE_UNIT_STRING, UNS(&units_seconds), 0x0, NULL, HFILL}},
2435         {&hf_ubx_nav_timegps_valid,
2436             {"Validity flags", "ubx.nav.timegps.valid",
2437                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2438         {&hf_ubx_nav_timegps_towvalid,
2439             {"Valid GPS time of week", "ubx.nav.timegps.valid.towvalid",
2440                 FT_BOOLEAN, 8, NULL, 0x01, NULL, HFILL}},
2441         {&hf_ubx_nav_timegps_weekvalid,
2442             {"Valid GPS week number", "ubx.nav.timegps.valid.weekvalid",
2443                 FT_BOOLEAN, 8, NULL, 0x02, NULL, HFILL}},
2444         {&hf_ubx_nav_timegps_leapsvalid,
2445             {"Valid GPS leap seconds", "ubx.nav.timegps.valid.leapsvalid",
2446                 FT_BOOLEAN, 8, NULL, 0x04, NULL, HFILL}},
2447         {&hf_ubx_nav_timegps_tacc,
2448             {"Time accuracy estimate", "ubx.nav.timegps.tacc",
2449                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_seconds), 0x0, NULL, HFILL}},
2450
2451         // NAV-TIMEUTC
2452         {&hf_ubx_nav_timeutc,
2453             {"UBX-NAV-TIMEUTC", "ubx.nav.timeutc",
2454                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
2455         {&hf_ubx_nav_timeutc_itow,
2456             {"iTOW", "ubx.nav.timeutc.itow",
2457                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2458         {&hf_ubx_nav_timeutc_tacc,
2459             {"Time accuracy estimate (UTC)", "ubx.nav.timeutc.tacc",
2460                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_nanoseconds), 0x0, NULL, HFILL}},
2461         {&hf_ubx_nav_timeutc_nano,
2462             {"Fraction of second (UTC)", "ubx.nav.timeutc.nano",
2463                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_nanoseconds), 0x0, NULL, HFILL}},
2464         {&hf_ubx_nav_timeutc_year,
2465             {"Year", "ubx.nav.timeutc.year",
2466                 FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2467         {&hf_ubx_nav_timeutc_month,
2468             {"Month", "ubx.nav.timeutc.month",
2469                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2470         {&hf_ubx_nav_timeutc_day,
2471             {"Day", "ubx.nav.timeutc.day",
2472                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2473         {&hf_ubx_nav_timeutc_hour,
2474             {"Hour of day", "ubx.nav.timeutc.hour",
2475                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2476         {&hf_ubx_nav_timeutc_min,
2477             {"Minute of hour", "ubx.nav.timeutc.min",
2478                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2479         {&hf_ubx_nav_timeutc_sec,
2480             {"Seconds of minute", "ubx.nav.timeutc.sec",
2481                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2482         {&hf_ubx_nav_timeutc_valid,
2483             {"Validity flags", "ubx.nav.timeutc.valid",
2484                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2485         {&hf_ubx_nav_timeutc_validtow,
2486             {"Valid Time of Week", "ubx.nav.timeutc.valid.validtow",
2487                 FT_BOOLEAN, 8, NULL, 0x01, NULL, HFILL}},
2488         {&hf_ubx_nav_timeutc_validwkn,
2489             {"Valid Week Number", "ubx.nav.timeutc.valid.validwkn",
2490                 FT_BOOLEAN, 8, NULL, 0x02, NULL, HFILL}},
2491         {&hf_ubx_nav_timeutc_validutc,
2492             {"Valid UTC Time", "ubx.nav.timeutc.valid.validutc",
2493                 FT_BOOLEAN, 8, NULL, 0x04, NULL, HFILL}},
2494         {&hf_ubx_nav_timeutc_utcstandard,
2495             {"utcStandard", "ubx.nav.timeutc.valid.utcstandard",
2496                 FT_UINT8, BASE_DEC, VALS(UBX_UTC_STD_ID), 0xf0, NULL, HFILL}},
2497
2498         // NAV-VELECEF
2499         {&hf_ubx_nav_velecef,
2500             {"UBX-NAV-VELECEF", "ubx.nav.velecef",
2501                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
2502         {&hf_ubx_nav_velecef_itow,
2503             {"iTOW", "ubx.nav.velecef.itow",
2504                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_seconds), 0x0, NULL, HFILL}},
2505         {&hf_ubx_nav_velecef_ecefvx,
2506             {"ECEF X velocity", "ubx.nav.velecef.ecefvx",
2507                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_cm_s), 0x0, NULL, HFILL}},
2508         {&hf_ubx_nav_velecef_ecefvy,
2509             {"ECEF Y velocity", "ubx.nav.velecef.ecefvy",
2510                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_cm_s), 0x0, NULL, HFILL}},
2511         {&hf_ubx_nav_velecef_ecefvz,
2512             {"ECEF Z velocity", "ubx.nav.velecef.ecefvz",
2513                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_cm_s), 0x0, NULL, HFILL}},
2514         {&hf_ubx_nav_velecef_sacc,
2515             {"Speed accuracy estimate", "ubx.nav.velecef.sacc",
2516                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_cm_s), 0x0, NULL, HFILL}},
2517
2518         // RXM-MEASX
2519         {&hf_ubx_rxm_measx,
2520             {"UBX-RXM-MEASX", "ubx.rxm.measx",
2521                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
2522         {&hf_ubx_rxm_measx_version,
2523             {"Message version", "ubx.rxm.measx.version",
2524                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2525         {&hf_ubx_rxm_measx_reserved1,
2526             {"Reserved", "ubx.rxm.measx.reserved1",
2527                 FT_UINT24, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2528         {&hf_ubx_rxm_measx_gpstow,
2529             {"GPS measurement reference time", "ubx.rxm.measx.gpstow",
2530                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2531         {&hf_ubx_rxm_measx_glotow,
2532             {"GLONASS measurement reference time", "ubx.rxm.measx.glotow",
2533                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2534         {&hf_ubx_rxm_measx_bdstow,
2535             {"BeiDou measurement reference time", "ubx.rxm.measx.bdstow",
2536                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2537         {&hf_ubx_rxm_measx_reserved2,
2538             {"Reserved", "ubx.rxm.measx.reserved2",
2539                 FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2540         {&hf_ubx_rxm_measx_qzsstow,
2541             {"QZSS measurement reference time", "ubx.rxm.measx.qzsstow",
2542                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2543         {&hf_ubx_rxm_measx_gpstowacc,
2544             {"GPS measurement reference time accuracy", "ubx.rxm.measx.gpstowacc",
2545                 FT_UINT16, BASE_CUSTOM, CF_FUNC(&fmt_towacc), 0x0, NULL, HFILL}},
2546         {&hf_ubx_rxm_measx_glotowacc,
2547             {"GLONASS measurement reference time accuracy", "ubx.rxm.measx.glotowacc",
2548                 FT_UINT16, BASE_CUSTOM, CF_FUNC(&fmt_towacc), 0x0, NULL, HFILL}},
2549         {&hf_ubx_rxm_measx_bdstowacc,
2550             {"BeiDou measurement reference time accuracy", "ubx.rxm.measx.bdstowacc",
2551                 FT_UINT16, BASE_CUSTOM, CF_FUNC(&fmt_towacc), 0x0, NULL, HFILL}},
2552         {&hf_ubx_rxm_measx_reserved3,
2553             {"Reserved", "ubx.rxm.measx.reserved3",
2554                 FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2555         {&hf_ubx_rxm_measx_qzsstowacc,
2556             {"QZSS measurement reference time accuracy", "ubx.rxm.measx.qzsstowacc",
2557                 FT_UINT16, BASE_CUSTOM, CF_FUNC(&fmt_towacc), 0x0, NULL, HFILL}},
2558         {&hf_ubx_rxm_measx_numsv,
2559             {"Number of satellites in repeated block", "ubx.rxm.measx.numsv",
2560                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2561         {&hf_ubx_rxm_measx_flags_towset,
2562             {"TOW set", "ubx.rxm.measx.flags.towset",
2563                 FT_BOOLEAN, 8, NULL, 0x03, NULL, HFILL}},
2564         {&hf_ubx_rxm_measx_reserved4,
2565             {"Reserved", "ubx.rxm.measx.reserved4",
2566                 FT_UINT64, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2567         {&hf_ubx_rxm_measx_gnssid,
2568             {"GNSS ID", "ubx.rxm.measx.gnssid",
2569                 FT_UINT8, BASE_DEC, VALS(UBX_GNSS_ID), 0x0, NULL, HFILL}},
2570         {&hf_ubx_rxm_measx_svid,
2571             {"Satellite ID", "ubx.rxm.measx.svid",
2572                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2573         {&hf_ubx_rxm_measx_cn0,
2574             {"C/N0", "ubx.rxm.measx.cn0",
2575                 FT_UINT8, BASE_DEC|BASE_UNIT_STRING, UNS(&units_dbhz), 0x0, NULL, HFILL}},
2576         {&hf_ubx_rxm_measx_mpathindic,
2577             {"multipath index", "ubx.rxm.measx.mpathindic",
2578                 FT_UINT8, BASE_DEC, VALS(UBX_RXM_MEASX_MULTIPATH_INDEX), 0x0, NULL, HFILL}},
2579         {&hf_ubx_rxm_measx_dopplerms,
2580             {"Doppler measurement", "ubx.rxm.measx.dopplerms",
2581                 FT_INT32, BASE_CUSTOM, CF_FUNC(&fmt_dopplerms), 0x0, NULL, HFILL}},
2582         {&hf_ubx_rxm_measx_dopplerhz,
2583             {"Doppler measurement", "ubx.rxm.measx.dopplerhz",
2584                 FT_INT32, BASE_CUSTOM, CF_FUNC(&fmt_dopplerhz), 0x0, NULL, HFILL}},
2585         {&hf_ubx_rxm_measx_wholechips,
2586             {"whole value of the code phase measurement", "ubx.rxm.measx.wholechips",
2587                 FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2588         {&hf_ubx_rxm_measx_fracchips,
2589             {"fractional value of the code phase measurement", "ubx.rxm.measx.fracchips",
2590                 FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2591         {&hf_ubx_rxm_measx_codephase,
2592             {"Code phase", "ubx.rxm.measx.codephase",
2593                 FT_UINT32, BASE_CUSTOM, CF_FUNC(&fmt_codephase), 0x0, NULL, HFILL}},
2594         {&hf_ubx_rxm_measx_intcodephase,
2595             {"integer (part of) the code phase", "ubx.rxm.measx.intcodephase",
2596                 FT_UINT8, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2597         {&hf_ubx_rxm_measx_pseurangermserr,
2598             {"pseudorange RMS error index", "ubx.rxm.measx.pseurangermserr",
2599                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2600         {&hf_ubx_rxm_measx_reserved5,
2601             {"Reserved", "ubx.rxm.measx.reserved5",
2602                 FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2603
2604         // RXM-RAWX
2605         {&hf_ubx_rxm_rawx,
2606             {"UBX-RXM-RAWX", "ubx.rxm.rawx",
2607                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
2608         {&hf_ubx_rxm_rawx_rcvtow,
2609             {"Measurement time of week in receiver local time", "ubx.rxm.rawx.rcvtow",
2610                 FT_DOUBLE, BASE_DEC|BASE_UNIT_STRING, UNS(&units_seconds), 0x0, NULL, HFILL}},
2611         {&hf_ubx_rxm_rawx_week,
2612             {"GPS week number in receiver local time", "ubx.rxm.rawx.week",
2613                 FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2614         {&hf_ubx_rxm_rawx_leaps,
2615             {"GPS leap seconds", "ubx.rxm.rawx.leaps",
2616                 FT_INT8, BASE_DEC|BASE_UNIT_STRING, UNS(&units_seconds), 0x0, NULL, HFILL}},
2617         {&hf_ubx_rxm_rawx_nummeas,
2618             {"Number of measurements to follow", "ubx.rxm.rawx.nummeas",
2619                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2620         {&hf_ubx_rxm_rawx_recstat,
2621             {"Receiver tracking status bitfield", "ubx.rxm.rawx.recstat",
2622                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2623         {&hf_ubx_rxm_rawx_recstat_leapsec,
2624             {"Leap seconds have been determined", "ubx.rxm.rawx.recstat.leapsec",
2625                 FT_BOOLEAN, 8, NULL, 0x01, NULL, HFILL}},
2626         {&hf_ubx_rxm_rawx_recstat_clkreset,
2627             {"Clock reset applied", "ubx.rxm.rawx.recstat.clkreset",
2628                 FT_BOOLEAN, 8, NULL, 0x02, NULL, HFILL}},
2629         {&hf_ubx_rxm_rawx_version,
2630             {"Message version", "ubx.rxm.rawx.version",
2631                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2632         {&hf_ubx_rxm_rawx_reserved1,
2633             {"Reserved", "ubx.rxm.rawx.reserved1",
2634                 FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2635         {&hf_ubx_rxm_rawx_prmes,
2636             {"Pseudorange measurement", "ubx.rxm.rawx.prmes",
2637                 FT_DOUBLE, BASE_DEC|BASE_UNIT_STRING, UNS(&units_meter_meters), 0x0, NULL, HFILL}},
2638         {&hf_ubx_rxm_rawx_cpmes,
2639             {"Carrier phase measurement", "ubx.rxm.rawx.cpmes",
2640                 FT_DOUBLE, BASE_DEC|BASE_UNIT_STRING, UNS(&units_cycle_cycles), 0x0, NULL, HFILL}},
2641         {&hf_ubx_rxm_rawx_domes,
2642             {"Doppler measurement", "ubx.rxm.rawx.domes",
2643                 FT_FLOAT, BASE_DEC|BASE_UNIT_STRING, UNS(&units_hz), 0x0, NULL, HFILL}},
2644         {&hf_ubx_rxm_rawx_gnssid,
2645             {"GNSS ID", "ubx.rxm.rawx.gnssid",
2646                 FT_UINT8, BASE_DEC, VALS(UBX_GNSS_ID), 0x0, NULL, HFILL}},
2647         {&hf_ubx_rxm_rawx_svid,
2648             {"Satellite ID", "ubx.rxm.rawx.svid",
2649                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2650         {&hf_ubx_rxm_rawx_sigid,
2651             {"Signal ID", "ubx.rxm.rawx.sigid",
2652                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2653         {&hf_ubx_rxm_rawx_freqid,
2654             {"Frequency ID", "ubx.rxm.rawx.freqid",
2655                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2656         {&hf_ubx_rxm_rawx_locktime,
2657             {"Carrier phase locktime counter", "ubx.rxm.rawx.locktime",
2658                 FT_UINT16, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2659         {&hf_ubx_rxm_rawx_cn0,
2660             {"C/N0", "ubx.rxm.rawx.cn0",
2661                 FT_UINT8, BASE_DEC|BASE_UNIT_STRING, UNS(&units_dbhz), 0x0, NULL, HFILL}},
2662         {&hf_ubx_rxm_rawx_prstdev,
2663             {"Estimated pseudorange measurement standard deviation", "ubx.rxm.rawx.prstdev",
2664                 FT_UINT8, BASE_CUSTOM, CF_FUNC(&fmt_prstdev), 0x0f, NULL, HFILL}},
2665         {&hf_ubx_rxm_rawx_cpstdev,
2666             {"Estimated carrier phase measurement standard deviation", "ubx.rxm.rawx.cpstdev",
2667                 FT_UINT8, BASE_CUSTOM, CF_FUNC(&fmt_cpstdev), 0x0f, NULL, HFILL}},
2668         {&hf_ubx_rxm_rawx_dostdev,
2669             {"Estimated Doppler measurement standard deviation", "ubx.rxm.rawx.dostdev",
2670                 FT_UINT8, BASE_CUSTOM, CF_FUNC(&fmt_dostdev), 0x0f, NULL, HFILL}},
2671         {&hf_ubx_rxm_rawx_trkstat,
2672             {"Tracking status bitfield", "ubx.rxm.rawx.trkstat",
2673                 FT_UINT8, BASE_HEX, NULL, 0x0f, NULL, HFILL}},
2674         {&hf_ubx_rxm_rawx_trkstat_prvalid,
2675             {"Pseudorange valid", "ubx.rxm.rawx.trkstat.prvalid",
2676                 FT_BOOLEAN, 8, NULL, 0x01, NULL, HFILL}},
2677         {&hf_ubx_rxm_rawx_trkstat_cpvalid,
2678             {"Carrier phase valid", "ubx.rxm.rawx.trkstat.cpvalid",
2679                 FT_BOOLEAN, 8, NULL, 0x02, NULL, HFILL}},
2680         {&hf_ubx_rxm_rawx_trkstat_halfcyc,
2681             {"Half cycle valid", "ubx.rxm.rawx.trkstat.halfcyc",
2682                 FT_BOOLEAN, 8, NULL, 0x04, NULL, HFILL}},
2683         {&hf_ubx_rxm_rawx_trkstat_subhalfcyc,
2684             {"Half cycle subtracted from phase", "ubx.rxm.rawx.trkstat.subhalfcyc",
2685                 FT_BOOLEAN, 8, NULL, 0x08, NULL, HFILL}},
2686         {&hf_ubx_rxm_rawx_reserved2,
2687             {"Reserved", "ubx.rxm.rawx.reserved2",
2688                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2689
2690         // RXM-SFRBX
2691         {&hf_ubx_rxm_sfrbx,
2692             {"UBX-RXM-SFRBX", "ubx.rxm.sfrbx",
2693                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
2694         {&hf_ubx_rxm_sfrbx_gnssid,
2695             {"GNSS ID", "ubx.rxm.sfrbx.gnssid",
2696                 FT_UINT8, BASE_DEC, VALS(UBX_GNSS_ID), 0x0, NULL, HFILL}},
2697         {&hf_ubx_rxm_sfrbx_svid,
2698             {"Satellite ID", "ubx.rxm.sfrbx.svid",
2699                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2700         {&hf_ubx_rxm_sfrbx_sigid,
2701             {"Signal identifier", "ubx.rxm.sfrbx.sigid",
2702                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2703         {&hf_ubx_rxm_sfrbx_freqid,
2704             {"Frequency identifier", "ubx.rxm.sfrbx.freqid",
2705                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2706         {&hf_ubx_rxm_sfrbx_numwords,
2707             {"Number of data words", "ubx.rxm.sfrbx.numwords",
2708                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2709         {&hf_ubx_rxm_sfrbx_chn,
2710             {"Tracking channel number", "ubx.rxm.sfrbx.chn",
2711                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2712         {&hf_ubx_rxm_sfrbx_version,
2713             {"Message version", "ubx.rxm.sfrbx.version",
2714                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2715         {&hf_ubx_rxm_sfrbx_dwrd,
2716             {"Data words (little endian)", "ubx.rxm.sfrbx.dwrd",
2717                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
2718         {&hf_ubx_rxm_sfrbx_reserved1,
2719             {"Reserved 1", "ubx.rxm.sfrbx.reserved1",
2720                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2721         {&hf_ubx_rxm_sfrbx_reserved2,
2722             {"Reserved 2", "ubx.rxm.sfrbx.reserved2",
2723                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2724         {&hf_ubx_rxm_sfrbx_reserved3,
2725             {"Reserved 3", "ubx.rxm.sfrbx.reserved3",
2726                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2727     };
2728
2729     expert_module_t *expert_ubx;
2730
2731     static ei_register_info ei[] = {
2732         {&ei_ubx_chksum, {"ubx.chksum", PI_CHECKSUM, PI_WARN, "Chksum", EXPFILL}},
2733     };
2734
2735     static int *ett_part[] = {
2736         &ett_ubx,
2737         &ett_ubx_ack_ack,
2738         &ett_ubx_ack_nak,
2739         &ett_ubx_cfg_gnss,
2740         &ett_ubx_cfg_sbas,
2741         &ett_ubx_cfg_sbas_mode,
2742         &ett_ubx_cfg_sbas_scanmode,
2743         &ett_ubx_nav_dop,
2744         &ett_ubx_nav_eoe,
2745         &ett_ubx_nav_odo,
2746         &ett_ubx_nav_posecef,
2747         &ett_ubx_nav_pvt,
2748         &ett_ubx_nav_pvt_datetime,
2749         &ett_ubx_nav_pvt_valid,
2750         &ett_ubx_nav_pvt_flags,
2751         &ett_ubx_nav_pvt_flags2,
2752         &ett_ubx_nav_sat,
2753         &ett_ubx_nav_sat_flags,
2754         &ett_ubx_nav_sbas,
2755         &ett_ubx_nav_sbas_service,
2756         &ett_ubx_nav_timegps,
2757         &ett_ubx_nav_timegps_tow,
2758         &ett_ubx_nav_timegps_valid,
2759         &ett_ubx_nav_timeutc,
2760         &ett_ubx_nav_timeutc_valid,
2761         &ett_ubx_nav_velecef,
2762         &ett_ubx_rxm_measx,
2763         &ett_ubx_rxm_rawx,
2764         &ett_ubx_rxm_rawx_recstat,
2765         &ett_ubx_rxm_rawx_trkstat,
2766         &ett_ubx_rxm_sfrbx,
2767     };
2768
2769     static int *ett[array_length(ett_part)
2770         + array_length(ett_ubx_nav_sat_sv_info)
2771         + array_length(ett_ubx_cfg_gnss_block)
2772         + array_length(ett_ubx_nav_sbas_sv_info)
2773         + array_length(ett_ubx_rxm_rawx_meas)
2774         + array_length(ett_ubx_rxm_measx_meas)];
2775
2776     // fill ett with elements from ett_part,
2777     // pointers to ett_ubx_nav_sat_sv_info elements,
2778     // pointers to ett_ubx_cfg_gnss_block elements,
2779     // pointers to ett_ubx_nav_sbas_sv_info elements,
2780     // pointers to ett_ubx_rxm_rawx_meas elements, and
2781     // pointers to ett_ubx_rxm_measx_meas elements
2782     uint16_t i;
2783     for (i = 0; i < array_length(ett_part); i++) {
2784         ett[i] = ett_part[i];
2785     }
2786     for (i = 0; i < array_length(ett_ubx_nav_sat_sv_info); i++) {
2787         ett[i + array_length(ett_part)] = &ett_ubx_nav_sat_sv_info[i];
2788     }
2789     for (i = 0; i < array_length(ett_ubx_cfg_gnss_block); i++) {
2790         ett[i + array_length(ett_part) + array_length(ett_ubx_nav_sat_sv_info)]
2791             = &ett_ubx_cfg_gnss_block[i];
2792     }
2793     for (i = 0; i < array_length(ett_ubx_nav_sbas_sv_info); i++) {
2794         ett[i + array_length(ett_part) + array_length(ett_ubx_nav_sat_sv_info)
2795             + array_length(ett_ubx_cfg_gnss_block)]
2796             = &ett_ubx_nav_sbas_sv_info[i];
2797     }
2798     for (i = 0; i < array_length(ett_ubx_rxm_rawx_meas); i++) {
2799         ett[i + array_length(ett_part) + array_length(ett_ubx_nav_sat_sv_info)
2800             + array_length(ett_ubx_cfg_gnss_block)
2801             + array_length(ett_ubx_nav_sbas_sv_info)]
2802             = &ett_ubx_rxm_rawx_meas[i];
2803     }
2804     for (i = 0; i < array_length(ett_ubx_rxm_measx_meas); i++) {
2805         ett[i + array_length(ett_part) + array_length(ett_ubx_nav_sat_sv_info)
2806             + array_length(ett_ubx_cfg_gnss_block)
2807             + array_length(ett_ubx_nav_sbas_sv_info)
2808             + array_length(ett_ubx_rxm_rawx_meas)]
2809             = &ett_ubx_rxm_measx_meas[i];
2810     }
2811
2812     proto_ubx = proto_register_protocol("UBX Protocol", "UBX", "ubx");
2813
2814     ubx_handle = register_dissector("ubx", dissect_ubx, proto_ubx);
2815
2816     proto_register_field_array(proto_ubx, hf, array_length(hf));
2817     proto_register_subtree_array(ett, array_length(ett));
2818
2819     expert_ubx = expert_register_protocol(proto_ubx);
2820     expert_register_field_array(expert_ubx, ei, array_length(ei));
2821
2822     ubx_class_id_dissector_table = register_dissector_table("ubx.msg_class_id",
2823             "UBX Message Class & ID", proto_ubx, FT_UINT16, BASE_HEX);
2824     ubx_gnssid_dissector_table = register_dissector_table("ubx.rxm.sfrbx.gnssid",
2825             "UBX-RXM-SFRBX GNSS Type ID", proto_ubx,
2826             FT_UINT8, BASE_DEC);
2827 }
2828
2829 void proto_reg_handoff_ubx(void) {
2830     UBX_REGISTER_DISSECTOR(dissect_ubx_ack_ack,     UBX_ACK_ACK);
2831     UBX_REGISTER_DISSECTOR(dissect_ubx_ack_nak,     UBX_ACK_NAK);
2832     UBX_REGISTER_DISSECTOR(dissect_ubx_cfg_gnss,    UBX_CFG_GNSS);
2833     UBX_REGISTER_DISSECTOR(dissect_ubx_cfg_sbas,    UBX_CFG_SBAS);
2834     UBX_REGISTER_DISSECTOR(dissect_ubx_nav_dop,     UBX_NAV_DOP);
2835     UBX_REGISTER_DISSECTOR(dissect_ubx_nav_eoe,     UBX_NAV_EOE);
2836     UBX_REGISTER_DISSECTOR(dissect_ubx_nav_odo,     UBX_NAV_ODO);
2837     UBX_REGISTER_DISSECTOR(dissect_ubx_nav_posecef, UBX_NAV_POSECEF);
2838     UBX_REGISTER_DISSECTOR(dissect_ubx_nav_pvt,     UBX_NAV_PVT);
2839     UBX_REGISTER_DISSECTOR(dissect_ubx_nav_sat,     UBX_NAV_SAT);
2840     UBX_REGISTER_DISSECTOR(dissect_ubx_nav_sbas,    UBX_NAV_SBAS);
2841     UBX_REGISTER_DISSECTOR(dissect_ubx_nav_timegps, UBX_NAV_TIMEGPS);
2842     UBX_REGISTER_DISSECTOR(dissect_ubx_nav_timeutc, UBX_NAV_TIMEUTC);
2843     UBX_REGISTER_DISSECTOR(dissect_ubx_nav_velecef, UBX_NAV_VELECEF);
2844     UBX_REGISTER_DISSECTOR(dissect_ubx_rxm_measx,   UBX_RXM_MEASX);
2845     UBX_REGISTER_DISSECTOR(dissect_ubx_rxm_rawx,    UBX_RXM_RAWX);
2846     UBX_REGISTER_DISSECTOR(dissect_ubx_rxm_sfrbx,   UBX_RXM_SFRBX);
2847 }