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,
1411             tvb, 16 + (12 * i),
1412             hf_ubx_nav_sat_flags, ett_ubx_nav_sat_flags,
1413             ubx_nav_sat_flags_fields, ENC_LITTLE_ENDIAN);
1414     }
1415
1416     return tvb_captured_length(tvb);
1417 }
1418
1419 /* Dissect UBX-NAV-SBAS message */
1420 static int dissect_ubx_nav_sbas(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
1421     uint16_t i;
1422     uint32_t num_svs;
1423
1424     col_set_str(pinfo->cinfo, COL_PROTOCOL, "UBX-NAV-SBAS");
1425     col_clear(pinfo->cinfo, COL_INFO);
1426
1427     num_svs = tvb_get_uint8(tvb, 8);
1428
1429     proto_item *ti = proto_tree_add_item(tree, hf_ubx_nav_sbas,
1430             tvb, 0, 12 + 12 * num_svs, ENC_NA);
1431     proto_tree *ubx_nav_sbas_tree = proto_item_add_subtree(ti, ett_ubx_nav_sbas);
1432
1433     proto_tree_add_item(ubx_nav_sbas_tree, hf_ubx_nav_sbas_itow,
1434             tvb, 0, 4, ENC_LITTLE_ENDIAN);
1435     proto_tree_add_item(ubx_nav_sbas_tree, hf_ubx_nav_sbas_geo,
1436             tvb, 4, 1, ENC_NA);
1437     proto_tree_add_item(ubx_nav_sbas_tree, hf_ubx_nav_sbas_mode,
1438             tvb, 5, 1, ENC_NA);
1439     proto_tree_add_item(ubx_nav_sbas_tree, hf_ubx_nav_sbas_sys,
1440             tvb, 6, 1, ENC_NA);
1441     proto_tree_add_bitmask(ubx_nav_sbas_tree, tvb, 7, hf_ubx_nav_sbas_service,
1442             ett_ubx_nav_sbas_service, ubx_nav_sbas_service_fields, ENC_NA);
1443     proto_tree_add_item(ubx_nav_sbas_tree, hf_ubx_nav_sbas_cnt,
1444             tvb, 8, 1, ENC_NA);
1445     proto_tree_add_item(ubx_nav_sbas_tree, hf_ubx_nav_sbas_reserved1,
1446             tvb, 9, 3, ENC_LITTLE_ENDIAN);
1447
1448     for (i = 0; i < num_svs; i++) {
1449         const uint8_t sv_id = tvb_get_uint8(tvb, 12 + 12 * i);
1450
1451         proto_tree *sv_info_tree = proto_tree_add_subtree_format(ubx_nav_sbas_tree,
1452                 tvb, 12 + (12 * i), 12, ett_ubx_nav_sbas_sv_info[i], NULL,
1453                 "SV ID %3d", sv_id);
1454
1455         proto_tree_add_item(sv_info_tree, hf_ubx_nav_sbas_sv_id,
1456             tvb,  12 + (12 * i), 1, ENC_NA);
1457         proto_tree_add_item(sv_info_tree, hf_ubx_nav_sbas_flags,
1458             tvb,  13 + (12 * i), 1, ENC_NA);
1459         proto_tree_add_item(sv_info_tree, hf_ubx_nav_sbas_udre,
1460             tvb,  14 + (12 * i), 1, ENC_NA);
1461         proto_tree_add_item(sv_info_tree, hf_ubx_nav_sbas_sv_sys,
1462             tvb,  15 + (12 * i), 1, ENC_NA);
1463         proto_tree_add_item(sv_info_tree, hf_ubx_nav_sbas_sv_service,
1464             tvb,  16 + (12 * i), 1, ENC_NA);
1465         proto_tree_add_item(sv_info_tree, hf_ubx_nav_sbas_reserved2,
1466             tvb,  17 + (12 * i), 1, ENC_NA);
1467         proto_tree_add_item(sv_info_tree, hf_ubx_nav_sbas_prc,
1468             tvb,  18 + (12 * i), 2, ENC_LITTLE_ENDIAN);
1469         proto_tree_add_item(sv_info_tree, hf_ubx_nav_sbas_reserved3,
1470             tvb,  20 + (12 * i), 2, ENC_LITTLE_ENDIAN);
1471         proto_tree_add_item(sv_info_tree, hf_ubx_nav_sbas_ic,
1472             tvb,  22 + (12 * i), 2, ENC_LITTLE_ENDIAN);
1473     }
1474
1475     return tvb_captured_length(tvb);
1476 }
1477
1478 /* Dissect UBX-NAV-TIMEGPS message */
1479 static int dissect_ubx_nav_timegps(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
1480     uint32_t itow;
1481     int32_t ftow;
1482
1483     col_set_str(pinfo->cinfo, COL_PROTOCOL, "UBX-NAV-TIMEGPS");
1484     col_clear(pinfo->cinfo, COL_INFO);
1485
1486     proto_item *ti = proto_tree_add_item(tree, hf_ubx_nav_timegps,
1487             tvb, 0, 16, ENC_NA);
1488     proto_tree *ubx_nav_timegps_tree = proto_item_add_subtree(ti, ett_ubx_nav_timegps);
1489
1490     // dissect the registered fields
1491     itow = tvb_get_uint32(tvb, 0, ENC_LITTLE_ENDIAN);
1492     ftow = tvb_get_int32(tvb, 4, ENC_LITTLE_ENDIAN);
1493     ftow = (itow % 1000) * 1000000 + ftow;
1494     itow = itow / 1000;
1495     if (ftow < 0) {
1496         itow = itow - 1;
1497         ftow = 1000000000 + ftow;
1498     }
1499     proto_tree *tow_tree = proto_tree_add_subtree_format(ubx_nav_timegps_tree,
1500             tvb, 0, 8, ett_ubx_nav_timegps_tow, NULL, "TOW: %d.%09ds", itow, ftow);
1501     proto_tree_add_item(tow_tree, hf_ubx_nav_timegps_itow,
1502             tvb, 0, 4, ENC_LITTLE_ENDIAN);
1503     proto_tree_add_item(tow_tree, hf_ubx_nav_timegps_ftow,
1504             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1505
1506     proto_tree_add_item(ubx_nav_timegps_tree, hf_ubx_nav_timegps_week,
1507             tvb, 8, 2, ENC_LITTLE_ENDIAN);
1508     proto_tree_add_item(ubx_nav_timegps_tree, hf_ubx_nav_timegps_leaps,
1509             tvb, 10, 1, ENC_NA);
1510     proto_tree_add_bitmask(ubx_nav_timegps_tree, tvb, 11,
1511             hf_ubx_nav_timegps_valid, ett_ubx_nav_timegps_valid,
1512             ubx_nav_timegps_valid_fields, ENC_NA);
1513     proto_tree_add_item(ubx_nav_timegps_tree, hf_ubx_nav_timegps_tacc,
1514             tvb, 12, 4, ENC_LITTLE_ENDIAN);
1515
1516     return tvb_captured_length(tvb);
1517 }
1518
1519 /* Dissect UBX-NAV-TIMEUTC message */
1520 static int dissect_ubx_nav_timeutc(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
1521     col_set_str(pinfo->cinfo, COL_PROTOCOL, "UBX-NAV-TIMEUTC");
1522     col_clear(pinfo->cinfo, COL_INFO);
1523
1524     proto_item *ti = proto_tree_add_item(tree, hf_ubx_nav_timeutc,
1525             tvb, 0, 20, ENC_NA);
1526     proto_tree *ubx_nav_timeutc_tree = proto_item_add_subtree(ti, ett_ubx_nav_timeutc);
1527
1528     proto_tree_add_item(ubx_nav_timeutc_tree, hf_ubx_nav_timeutc_itow,
1529             tvb, 0, 4, ENC_LITTLE_ENDIAN);
1530     proto_tree_add_item(ubx_nav_timeutc_tree, hf_ubx_nav_timeutc_tacc,
1531             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1532     proto_tree_add_item(ubx_nav_timeutc_tree, hf_ubx_nav_timeutc_nano,
1533             tvb, 8, 4, ENC_LITTLE_ENDIAN);
1534     proto_tree_add_item(ubx_nav_timeutc_tree, hf_ubx_nav_timeutc_year,
1535             tvb, 12, 2, ENC_LITTLE_ENDIAN);
1536     proto_tree_add_item(ubx_nav_timeutc_tree, hf_ubx_nav_timeutc_month,
1537             tvb, 14, 1, ENC_NA);
1538     proto_tree_add_item(ubx_nav_timeutc_tree, hf_ubx_nav_timeutc_day,
1539             tvb, 15, 1, ENC_NA);
1540     proto_tree_add_item(ubx_nav_timeutc_tree, hf_ubx_nav_timeutc_hour,
1541             tvb, 16, 1, ENC_NA);
1542     proto_tree_add_item(ubx_nav_timeutc_tree, hf_ubx_nav_timeutc_min,
1543             tvb, 17, 1, ENC_NA);
1544     proto_tree_add_item(ubx_nav_timeutc_tree, hf_ubx_nav_timeutc_sec,
1545             tvb, 18, 1, ENC_NA);
1546     proto_tree_add_bitmask(ubx_nav_timeutc_tree, tvb, 19,
1547             hf_ubx_nav_timeutc_valid, ett_ubx_nav_timeutc_valid,
1548             ubx_nav_timeutc_valid_fields, ENC_NA);
1549
1550     return tvb_captured_length(tvb);
1551 }
1552
1553 /* Dissect UBX-NAV-VELECEF message */
1554 static int dissect_ubx_nav_velecef(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
1555     col_set_str(pinfo->cinfo, COL_PROTOCOL, "UBX-NAV-VELECEF");
1556     col_clear(pinfo->cinfo, COL_INFO);
1557
1558     proto_item *ti = proto_tree_add_item(tree, hf_ubx_nav_velecef,
1559             tvb, 0, 20, ENC_NA);
1560     proto_tree *ubx_nav_velecef_tree = proto_item_add_subtree(ti, ett_ubx_nav_velecef);
1561
1562     // dissect the registered fields
1563     proto_tree_add_item(ubx_nav_velecef_tree, hf_ubx_nav_velecef_itow,
1564             tvb, 0, 4, ENC_LITTLE_ENDIAN);
1565     proto_tree_add_item(ubx_nav_velecef_tree, hf_ubx_nav_velecef_ecefvx,
1566             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1567     proto_tree_add_item(ubx_nav_velecef_tree, hf_ubx_nav_velecef_ecefvy,
1568             tvb, 8, 4, ENC_LITTLE_ENDIAN);
1569     proto_tree_add_item(ubx_nav_velecef_tree, hf_ubx_nav_velecef_ecefvz,
1570             tvb, 12, 4, ENC_LITTLE_ENDIAN);
1571     proto_tree_add_item(ubx_nav_velecef_tree, hf_ubx_nav_velecef_sacc,
1572             tvb, 16, 4, ENC_LITTLE_ENDIAN);
1573
1574     return tvb_captured_length(tvb);
1575 }
1576
1577 /* Dissect UBX-RXM-MEASX message */
1578 static int dissect_ubx_rxm_measx(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
1579     uint32_t i, numsv;
1580
1581     col_set_str(pinfo->cinfo, COL_PROTOCOL, "UBX-RXM-MEASX");
1582     col_clear(pinfo->cinfo, COL_INFO);
1583
1584     numsv = tvb_get_uint8(tvb, 34);
1585
1586     proto_item *ti = proto_tree_add_item(tree, hf_ubx_rxm_measx,
1587             tvb, 0, 44 + numsv * 24, ENC_NA);
1588     proto_tree *ubx_rxm_measx_tree = proto_item_add_subtree(ti, ett_ubx_rxm_measx);
1589
1590     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_version,
1591             tvb, 0, 1, ENC_NA);
1592     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_reserved1,
1593             tvb, 1, 3, ENC_LITTLE_ENDIAN);
1594     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_gpstow,
1595             tvb, 4, 4, ENC_LITTLE_ENDIAN);
1596     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_glotow,
1597             tvb, 8, 4, ENC_LITTLE_ENDIAN);
1598     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_bdstow,
1599             tvb, 12, 4, ENC_LITTLE_ENDIAN);
1600     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_reserved2,
1601             tvb, 16, 4, ENC_LITTLE_ENDIAN);
1602     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_qzsstow,
1603             tvb, 20, 4, ENC_LITTLE_ENDIAN);
1604     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_gpstowacc,
1605             tvb, 24, 2, ENC_LITTLE_ENDIAN);
1606     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_glotowacc,
1607             tvb, 26, 2, ENC_LITTLE_ENDIAN);
1608     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_bdstowacc,
1609             tvb, 28, 2, ENC_LITTLE_ENDIAN);
1610     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_reserved3,
1611             tvb, 30, 2, ENC_LITTLE_ENDIAN);
1612     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_qzsstowacc,
1613             tvb, 32, 2, ENC_LITTLE_ENDIAN);
1614     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_numsv,
1615             tvb, 34, 1, ENC_NA);
1616     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_flags_towset,
1617             tvb, 35, 1, ENC_NA);
1618     proto_tree_add_item(ubx_rxm_measx_tree, hf_ubx_rxm_measx_reserved4,
1619             tvb, 36, 8, ENC_LITTLE_ENDIAN);
1620
1621     for (i = 0; i < numsv; i++) {
1622         const uint8_t gnss_id = tvb_get_uint8(tvb, 44 + 24 * i);
1623         const uint8_t sv_id = tvb_get_uint8(tvb, 45 + 24 * i);
1624         const uint8_t cn0 = tvb_get_uint8(tvb, 46 + 24 * i);
1625
1626         proto_tree *meas_tree = proto_tree_add_subtree_format(ubx_rxm_measx_tree,
1627                 tvb, 44 + 24 * i, 24, ett_ubx_rxm_measx_meas[i], NULL,
1628                 "%-7s / SV ID %3d / C/N0 %d dB-Hz",
1629                 val_to_str_const(gnss_id, UBX_GNSS_ID, "Unknown GNSS ID"),
1630                 sv_id, cn0);
1631
1632         proto_tree_add_item(meas_tree, hf_ubx_rxm_measx_gnssid,
1633                 tvb, 44 + 24 * i, 1, ENC_NA);
1634         proto_tree_add_item(meas_tree, hf_ubx_rxm_measx_svid,
1635                 tvb, 45 + 24 * i, 1, ENC_NA);
1636         proto_tree_add_item(meas_tree, hf_ubx_rxm_measx_cn0,
1637                 tvb, 46 + 24 * i, 1, ENC_NA);
1638         proto_tree_add_item(meas_tree, hf_ubx_rxm_measx_mpathindic,
1639                 tvb, 47 + 24 * i, 1, ENC_NA);
1640         proto_tree_add_item(meas_tree, hf_ubx_rxm_measx_dopplerms,
1641                 tvb, 48 + 24 * i, 4, ENC_LITTLE_ENDIAN);
1642         proto_tree_add_item(meas_tree, hf_ubx_rxm_measx_dopplerhz,
1643                 tvb, 52 + 24 * i, 4, ENC_LITTLE_ENDIAN);
1644         proto_tree_add_item(meas_tree, hf_ubx_rxm_measx_wholechips,
1645                 tvb, 56 + 24 * i, 2, ENC_LITTLE_ENDIAN);
1646         proto_tree_add_item(meas_tree, hf_ubx_rxm_measx_fracchips,
1647                 tvb, 58 + 24 * i, 2, ENC_LITTLE_ENDIAN);
1648         proto_tree_add_item(meas_tree, hf_ubx_rxm_measx_codephase,
1649                 tvb, 60 + 24 * i, 4, ENC_LITTLE_ENDIAN);
1650         proto_tree_add_item(meas_tree, hf_ubx_rxm_measx_intcodephase,
1651                 tvb, 64 + 24 * i, 1, ENC_NA);
1652         proto_tree_add_item(meas_tree, hf_ubx_rxm_measx_pseurangermserr,
1653                 tvb, 65 + 24 * i, 1, ENC_NA);
1654         proto_tree_add_item(meas_tree, hf_ubx_rxm_measx_reserved5,
1655                 tvb, 66 + 24 * i, 2, ENC_LITTLE_ENDIAN);
1656     }
1657
1658     return tvb_captured_length(tvb);
1659 }
1660
1661 /* Dissect UBX-RXM-RAWX message */
1662 static int dissect_ubx_rxm_rawx(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
1663     uint32_t i, nummeas;
1664
1665     col_set_str(pinfo->cinfo, COL_PROTOCOL, "UBX-RXM-RAWX");
1666     col_clear(pinfo->cinfo, COL_INFO);
1667
1668     nummeas = tvb_get_uint8(tvb, 11);
1669
1670     proto_item *ti = proto_tree_add_item(tree, hf_ubx_rxm_rawx,
1671             tvb, 0, 16 + nummeas * 32, ENC_NA);
1672     proto_tree *ubx_rxm_rawx_tree = proto_item_add_subtree(ti, ett_ubx_rxm_rawx);
1673
1674     proto_tree_add_item(ubx_rxm_rawx_tree, hf_ubx_rxm_rawx_rcvtow,
1675             tvb, 0, 8, ENC_LITTLE_ENDIAN);
1676     proto_tree_add_item(ubx_rxm_rawx_tree, hf_ubx_rxm_rawx_week,
1677             tvb, 8, 2, ENC_LITTLE_ENDIAN);
1678     proto_tree_add_item(ubx_rxm_rawx_tree, hf_ubx_rxm_rawx_leaps,
1679             tvb, 10, 1, ENC_NA);
1680     proto_tree_add_item(ubx_rxm_rawx_tree, hf_ubx_rxm_rawx_nummeas,
1681             tvb, 11, 1, ENC_NA);
1682     proto_tree_add_bitmask(ubx_rxm_rawx_tree, tvb, 12,
1683             hf_ubx_rxm_rawx_recstat, ett_ubx_rxm_rawx_recstat,
1684             ubx_rxm_rawx_recstat_fields, ENC_NA);
1685     proto_tree_add_item(ubx_rxm_rawx_tree, hf_ubx_rxm_rawx_version,
1686             tvb, 13, 1, ENC_NA);
1687     proto_tree_add_item(ubx_rxm_rawx_tree, hf_ubx_rxm_rawx_reserved1,
1688             tvb, 14, 2, ENC_LITTLE_ENDIAN);
1689
1690     for (i = 0; i < nummeas; i++) {
1691         const uint8_t gnss_id = tvb_get_uint8(tvb, 36 + 32 * i);
1692         const uint8_t sv_id = tvb_get_uint8(tvb, 37 + 32 * i);
1693         const uint8_t cn0 = tvb_get_uint8(tvb, 42 + 32 * i);
1694
1695         proto_tree *meas_tree = proto_tree_add_subtree_format(ubx_rxm_rawx_tree,
1696                 tvb, 16 + 32 * i, 32, ett_ubx_rxm_rawx_meas[i], NULL,
1697                 "%-7s / SV ID %3d / C/N0 %d dB-Hz",
1698                 val_to_str_const(gnss_id, UBX_GNSS_ID, "Unknown GNSS ID"),
1699                 sv_id, cn0);
1700
1701         proto_tree_add_item(meas_tree, hf_ubx_rxm_rawx_prmes,
1702                 tvb, 16 + (32 * i), 8, ENC_LITTLE_ENDIAN);
1703         proto_tree_add_item(meas_tree, hf_ubx_rxm_rawx_cpmes,
1704                 tvb, 24 + (32 * i), 8, ENC_LITTLE_ENDIAN);
1705         proto_tree_add_item(meas_tree, hf_ubx_rxm_rawx_domes,
1706                 tvb, 32 + (32 * i), 4, ENC_LITTLE_ENDIAN);
1707         proto_tree_add_item(meas_tree, hf_ubx_rxm_rawx_gnssid,
1708                 tvb, 36 + (32 * i), 1, ENC_NA);
1709         proto_tree_add_item(meas_tree, hf_ubx_rxm_rawx_svid,
1710                 tvb, 37 + (32 * i), 1, ENC_NA);
1711         proto_tree_add_item(meas_tree, hf_ubx_rxm_rawx_sigid,
1712                 tvb, 38 + (32 * i), 1, ENC_NA);
1713         proto_tree_add_item(meas_tree, hf_ubx_rxm_rawx_freqid,
1714                 tvb, 39 + (32 * i), 1, ENC_NA);
1715         proto_tree_add_item(meas_tree, hf_ubx_rxm_rawx_locktime,
1716                 tvb, 40 + (32 * i), 2, ENC_LITTLE_ENDIAN);
1717         proto_tree_add_item(meas_tree, hf_ubx_rxm_rawx_cn0,
1718                 tvb, 42 + (32 * i), 1, ENC_NA);
1719         proto_tree_add_item(meas_tree, hf_ubx_rxm_rawx_prstdev,
1720                 tvb, 43 + (32 * i), 1, ENC_NA);
1721         proto_tree_add_item(meas_tree, hf_ubx_rxm_rawx_cpstdev,
1722                 tvb, 44 + (32 * i), 1, ENC_NA);
1723         proto_tree_add_item(meas_tree, hf_ubx_rxm_rawx_dostdev,
1724                 tvb, 45 + (32 * i), 1, ENC_NA);
1725         proto_tree_add_bitmask(meas_tree,
1726                 tvb, 46 + (32 * i),
1727                 hf_ubx_rxm_rawx_trkstat, ett_ubx_rxm_rawx_trkstat,
1728                 ubx_rxm_rawx_trkstat_fields, ENC_NA);
1729         proto_tree_add_item(meas_tree, hf_ubx_rxm_rawx_reserved2,
1730                 tvb, 47 + (32 * i), 1, ENC_NA);
1731     }
1732
1733     return tvb_captured_length(tvb);
1734 }
1735
1736 /* Dissect UBX-RXM-SFRBX message */
1737 static int dissect_ubx_rxm_sfrbx(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) {
1738     tvbuff_t *next_tvb;
1739     uint8_t *buf;
1740     uint8_t i;
1741     uint32_t gnssid, numwords, version;
1742
1743     col_set_str(pinfo->cinfo, COL_PROTOCOL, "UBX-RXM-SFRBX");
1744     col_clear(pinfo->cinfo, COL_INFO);
1745
1746     // get length of the payload and protocol version
1747     numwords = tvb_get_uint8(tvb, 4);
1748     version = tvb_get_uint8(tvb, 6);
1749
1750     proto_item *ti = proto_tree_add_item(tree, hf_ubx_rxm_sfrbx,
1751             tvb, 0, 8 + numwords * 4, ENC_NA);
1752     proto_tree *ubx_rxm_sfrbx_tree = proto_item_add_subtree(ti, ett_ubx_rxm_sfrbx);
1753
1754     proto_tree_add_item_ret_uint(ubx_rxm_sfrbx_tree, hf_ubx_rxm_sfrbx_gnssid,
1755             tvb, 0, 1, ENC_NA, &gnssid);
1756     proto_tree_add_item(ubx_rxm_sfrbx_tree, hf_ubx_rxm_sfrbx_svid,
1757             tvb, 1, 1, ENC_NA);
1758     switch(version) {
1759         case 0x01: proto_tree_add_item(ubx_rxm_sfrbx_tree,
1760                            hf_ubx_rxm_sfrbx_reserved1, tvb, 2, 1, ENC_NA);
1761                    break;
1762         case 0x02: proto_tree_add_item(ubx_rxm_sfrbx_tree,
1763                            hf_ubx_rxm_sfrbx_sigid, tvb, 2, 1, ENC_NA);
1764                    break;
1765     }
1766     proto_tree_add_item(ubx_rxm_sfrbx_tree, hf_ubx_rxm_sfrbx_freqid,
1767             tvb, 3, 1, ENC_NA);
1768     proto_tree_add_item(ubx_rxm_sfrbx_tree, hf_ubx_rxm_sfrbx_numwords,
1769             tvb, 4, 1, ENC_NA);
1770     switch(version) {
1771         case 0x01: proto_tree_add_item(ubx_rxm_sfrbx_tree,
1772                            hf_ubx_rxm_sfrbx_reserved2, tvb, 5, 1, ENC_NA);
1773                    break;
1774         case 0x02: proto_tree_add_item(ubx_rxm_sfrbx_tree,
1775                            hf_ubx_rxm_sfrbx_chn, tvb, 5, 1, ENC_NA);
1776                    break;
1777     }
1778     proto_tree_add_item(ubx_rxm_sfrbx_tree, hf_ubx_rxm_sfrbx_version,
1779             tvb, 6, 1, ENC_NA);
1780     switch(version) {
1781         case 0x01: proto_tree_add_item(ubx_rxm_sfrbx_tree,
1782                            hf_ubx_rxm_sfrbx_reserved3, tvb, 7, 1, ENC_NA);
1783                    break;
1784         case 0x02: proto_tree_add_item(ubx_rxm_sfrbx_tree,
1785                            hf_ubx_rxm_sfrbx_reserved1, tvb, 7, 1, ENC_NA);
1786                    break;
1787     }
1788     proto_tree_add_item(ubx_rxm_sfrbx_tree, hf_ubx_rxm_sfrbx_dwrd,
1789             tvb, 8, numwords * 4, ENC_NA);
1790
1791     if (gnssid == GNSS_ID_GPS) {
1792         // send the GPS nav msg (preprocessed by UBX) to the next dissector
1793         next_tvb = tvb_new_subset_length(tvb, 8, 4 * numwords);
1794     }
1795     else {
1796         // UBX-RXM-SFRBX has the nav msg encoded in little endian. As this is not
1797         // convenient for dissection, map to big endian and add as new data source.
1798         buf = wmem_alloc(pinfo->pool, numwords * 4);
1799         for (i = 0; i < numwords; i++) {
1800             phton32(buf + 4 * i, tvb_get_uint32(tvb, 8 + i * 4, ENC_LITTLE_ENDIAN));
1801         }
1802         next_tvb = tvb_new_child_real_data(tvb, (uint8_t *)buf, numwords * 4, numwords * 4);
1803         add_new_data_source(pinfo, next_tvb, "GNSS navigation message");
1804     }
1805
1806     // send the nav msg to the next dissector
1807     if (!dissector_try_uint_with_data(ubx_gnssid_dissector_table, gnssid, next_tvb, pinfo, tree, true, (void *)tvb_get_ptr(tvb, 1, 1))) {
1808         call_data_dissector(next_tvb, pinfo, tree);
1809     }
1810
1811     return tvb_captured_length(tvb);
1812 }
1813
1814 void proto_register_ubx(void) {
1815     static hf_register_info hf[] = {
1816         {&hf_ubx_preamble,
1817             {"Preamble", "ubx.preamble",
1818                 FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL}},
1819         {&hf_ubx_msg_class_id,
1820             {"Msg Class & ID", "ubx.msg_class_id",
1821                 FT_UINT16, BASE_HEX, VALS(UBX_MSG_CLASS_ID), 0x0, NULL, HFILL}},
1822         {&hf_ubx_payload_len,
1823             {"Payload Length", "ubx.payload_len",
1824                 FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL}},
1825         {&hf_ubx_chksum,
1826             {"Checksum", "ubx.checksum",
1827                 FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL}},
1828
1829         // ACK-ACK
1830         {&hf_ubx_ack_ack,
1831             {"UBX-ACK-ACK", "ubx.ack.ack",
1832                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
1833         {&hf_ubx_ack_ack_msg_class_id,
1834             {"Msg Class & ID", "ubx.ack.ack.msg_class_id",
1835                 FT_UINT16, BASE_HEX, VALS(UBX_MSG_CLASS_ID), 0x0, NULL, HFILL}},
1836
1837         // ACK-NAK
1838         {&hf_ubx_ack_nak,
1839             {"UBX-ACK-NAK", "ubx.ack.nak",
1840                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
1841         {&hf_ubx_ack_nak_msg_class_id,
1842             {"Msg Class & ID", "ubx.ack.nak.msg_class_id",
1843                 FT_UINT16, BASE_HEX, VALS(UBX_MSG_CLASS_ID), 0x0, NULL, HFILL}},
1844
1845         // CFG-GNSS
1846         {&hf_ubx_cfg_gnss,
1847             {"UBX-CFG-GNSS", "ubx.cfg.gnss",
1848                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
1849         {&hf_ubx_cfg_gnss_version,
1850             {"Version", "ubx.cfg.gnss.version",
1851                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
1852         {&hf_ubx_cfg_gnss_numtrkchhw,
1853             {"Number of tracking channels available in hardware", "ubx.cfg.gnss.numtrkchhw",
1854                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
1855         {&hf_ubx_cfg_gnss_numtrkchuse,
1856             {"Number of tracking channels to use", "ubx.cfg.gnss.numtrkchuse",
1857                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
1858         {&hf_ubx_cfg_gnss_numconfigblocks,
1859             {"Number of configuration blocks following", "ubx.cfg.gnss.numconfigblocks",
1860                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
1861         {&hf_ubx_cfg_gnss_blk_gnssid,
1862             {"GNSS ID", "ubx.cfg.gnss.gnssid",
1863                 FT_UINT8, BASE_DEC, VALS(UBX_GNSS_ID), 0x0, NULL, HFILL}},
1864         {&hf_ubx_cfg_gnss_blk_restrkch,
1865             {"Number of reserved (minimum) tracking channels", "ubx.cfg.gnss.restrkch",
1866                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
1867         {&hf_ubx_cfg_gnss_blk_maxtrkch,
1868             {"Maximum number of tracking channels", "ubx.cfg.gnss.maxtrkch",
1869                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
1870         {&hf_ubx_cfg_gnss_blk_reserved1,
1871             {"Reserved", "ubx.cfg.gnss.reserved1",
1872                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
1873         {&hf_ubx_cfg_gnss_blk_enable,
1874             {"Enabled", "ubx.cfg.gnss.enabled",
1875                 FT_UINT32, BASE_HEX, NULL, 0x00000001, NULL, HFILL}},
1876         {&hf_ubx_cfg_gnss_blk_sigcfgmask,
1877             {"Signal configuration mask", "ubx.cfg.gnss.sigcfgmask",
1878                 FT_UINT32, BASE_HEX, NULL, 0x00ff0000, NULL, HFILL}},
1879         {&hf_ubx_cfg_gnss_blk_gps_sigcfgmask,
1880             {"Signal configuration mask", "ubx.cfg.gnss.sigcfgmask",
1881                 FT_UINT32, BASE_HEX, VALS(UBX_CFG_GNSS_GPS_SIGCFGMASK), 0x00ff0000, NULL, HFILL}},
1882         {&hf_ubx_cfg_gnss_blk_sbas_sigcfgmask,
1883             {"Signal configuration mask", "ubx.cfg.gnss.sigcfgmask",
1884                 FT_UINT32, BASE_HEX, VALS(UBX_CFG_GNSS_SBAS_SIGCFGMASK), 0x00ff0000, NULL, HFILL}},
1885         {&hf_ubx_cfg_gnss_blk_gal_sigcfgmask,
1886             {"Signal configuration mask", "ubx.cfg.gnss.sigcfgmask",
1887                 FT_UINT32, BASE_HEX, VALS(UBX_CFG_GNSS_GAL_SIGCFGMASK), 0x00ff0000, NULL, HFILL}},
1888         {&hf_ubx_cfg_gnss_blk_bds_sigcfgmask,
1889             {"Signal configuration mask", "ubx.cfg.gnss.sigcfgmask",
1890                 FT_UINT32, BASE_HEX, VALS(UBX_CFG_GNSS_BDS_SIGCFGMASK), 0x00ff0000, NULL, HFILL}},
1891         {&hf_ubx_cfg_gnss_blk_imes_sigcfgmask,
1892             {"Signal configuration mask", "ubx.cfg.gnss.sigcfgmask",
1893                 FT_UINT32, BASE_HEX, VALS(UBX_CFG_GNSS_IMES_SIGCFGMASK), 0x00ff0000, NULL, HFILL}},
1894         {&hf_ubx_cfg_gnss_blk_qzss_sigcfgmask,
1895             {"Signal configuration mask", "ubx.cfg.gnss.sigcfgmask",
1896                 FT_UINT32, BASE_HEX, VALS(UBX_CFG_GNSS_QZSS_SIGCFGMASK), 0x00ff0000, NULL, HFILL}},
1897         {&hf_ubx_cfg_gnss_blk_glo_sigcfgmask,
1898             {"Signal configuration mask", "ubx.cfg.gnss.sigcfgmask",
1899                 FT_UINT32, BASE_HEX, VALS(UBX_CFG_GNSS_GLO_SIGCFGMASK), 0x00ff0000, NULL, HFILL}},
1900
1901         // CFG-SBAS
1902         {&hf_ubx_cfg_sbas,
1903             {"UBX-CFG-SBAS", "ubx.cfg.sbas",
1904                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
1905         {&hf_ubx_cfg_sbas_mode,
1906             {"SBAS mode", "ubx.cfg.sbas.mode",
1907                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
1908         {&hf_ubx_cfg_sbas_mode_enabled,
1909             {"SBAS enabled", "ubx.cfg.sbas.mode.enabled",
1910                 FT_BOOLEAN, 8, NULL, 0x01, NULL, HFILL}},
1911         {&hf_ubx_cfg_sbas_mode_test,
1912             {"SBAS testbed", "ubx.cfg.sbas.mode.test",
1913                 FT_UINT8, BASE_HEX, VALS(UBX_SBAS_TESTBED), 0x02, NULL, HFILL}},
1914         {&hf_ubx_cfg_sbas_usage_range,
1915             {"Use SBAS GEOs as a ranging source (for navigation)", "ubx.cfg.sbas.usage.range",
1916                 FT_UINT8, BASE_HEX, NULL, 0x01, NULL, HFILL}},
1917         {&hf_ubx_cfg_sbas_usage_diffcorr,
1918             {"Use SBAS differential corrections", "ubx.cfg.sbas.usage.diffcorr",
1919                 FT_UINT8, BASE_HEX, NULL, 0x02, NULL, HFILL}},
1920         {&hf_ubx_cfg_sbas_usage_integrity,
1921             {"Use SBAS integrity information", "ubx.cfg.sbas.usage.integrity",
1922                 FT_UINT8, BASE_HEX, NULL, 0x04, NULL, HFILL}},
1923         {&hf_ubx_cfg_sbas_max_sbas,
1924             {"Maximum number of SBAS prioritized tracking channels to use", "ubx.cfg.sbas.maxsbas",
1925                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
1926         {&hf_ubx_cfg_sbas_scanmode_prn158,
1927             {"PRN 158", "ubx.cfg.sbas.scanmode.prn158",
1928                 FT_UINT8, BASE_HEX, NULL, 0x40, NULL, HFILL}},
1929         {&hf_ubx_cfg_sbas_scanmode_prn157,
1930             {"PRN 157", "ubx.cfg.sbas.scanmode.prn157",
1931                 FT_UINT8, BASE_HEX, NULL, 0x20, NULL, HFILL}},
1932         {&hf_ubx_cfg_sbas_scanmode_prn156,
1933             {"PRN 156", "ubx.cfg.sbas.scanmode.prn156",
1934                 FT_UINT8, BASE_HEX, NULL, 0x10, NULL, HFILL}},
1935         {&hf_ubx_cfg_sbas_scanmode_prn155,
1936             {"PRN 155", "ubx.cfg.sbas.scanmode.prn155",
1937                 FT_UINT8, BASE_HEX, NULL, 0x08, NULL, HFILL}},
1938         {&hf_ubx_cfg_sbas_scanmode_prn154,
1939             {"PRN 154", "ubx.cfg.sbas.scanmode.prn154",
1940                 FT_UINT8, BASE_HEX, NULL, 0x04, NULL, HFILL}},
1941         {&hf_ubx_cfg_sbas_scanmode_prn153,
1942             {"PRN 153", "ubx.cfg.sbas.scanmode.prn153",
1943                 FT_UINT8, BASE_HEX, NULL, 0x02, NULL, HFILL}},
1944         {&hf_ubx_cfg_sbas_scanmode_prn152,
1945             {"PRN 152", "ubx.cfg.sbas.scanmode.prn152",
1946                 FT_UINT8, BASE_HEX, NULL, 0x01, NULL, HFILL}},
1947         {&hf_ubx_cfg_sbas_scanmode_prn151,
1948             {"PRN 151", "ubx.cfg.sbas.scanmode.prn151",
1949                 FT_UINT32, BASE_HEX, NULL, 0x80000000, NULL, HFILL}},
1950         {&hf_ubx_cfg_sbas_scanmode_prn150,
1951             {"PRN 150", "ubx.cfg.sbas.scanmode.prn150",
1952                 FT_UINT32, BASE_HEX, NULL, 0x40000000, NULL, HFILL}},
1953         {&hf_ubx_cfg_sbas_scanmode_prn149,
1954             {"PRN 149", "ubx.cfg.sbas.scanmode.prn149",
1955                 FT_UINT32, BASE_HEX, NULL, 0x20000000, NULL, HFILL}},
1956         {&hf_ubx_cfg_sbas_scanmode_prn148,
1957             {"PRN 148", "ubx.cfg.sbas.scanmode.prn148",
1958                 FT_UINT32, BASE_HEX, NULL, 0x10000000, NULL, HFILL}},
1959         {&hf_ubx_cfg_sbas_scanmode_prn147,
1960             {"PRN 147", "ubx.cfg.sbas.scanmode.prn147",
1961                 FT_UINT32, BASE_HEX, NULL, 0x08000000, NULL, HFILL}},
1962         {&hf_ubx_cfg_sbas_scanmode_prn146,
1963             {"PRN 146", "ubx.cfg.sbas.scanmode.prn146",
1964                 FT_UINT32, BASE_HEX, NULL, 0x04000000, NULL, HFILL}},
1965         {&hf_ubx_cfg_sbas_scanmode_prn145,
1966             {"PRN 145", "ubx.cfg.sbas.scanmode.prn145",
1967                 FT_UINT32, BASE_HEX, NULL, 0x02000000, NULL, HFILL}},
1968         {&hf_ubx_cfg_sbas_scanmode_prn144,
1969             {"PRN 144", "ubx.cfg.sbas.scanmode.prn144",
1970                 FT_UINT32, BASE_HEX, NULL, 0x01000000, NULL, HFILL}},
1971         {&hf_ubx_cfg_sbas_scanmode_prn143,
1972             {"PRN 143", "ubx.cfg.sbas.scanmode.prn143",
1973                 FT_UINT32, BASE_HEX, NULL, 0x00800000, NULL, HFILL}},
1974         {&hf_ubx_cfg_sbas_scanmode_prn142,
1975             {"PRN 142", "ubx.cfg.sbas.scanmode.prn142",
1976                 FT_UINT32, BASE_HEX, NULL, 0x00400000, NULL, HFILL}},
1977         {&hf_ubx_cfg_sbas_scanmode_prn141,
1978             {"PRN 141", "ubx.cfg.sbas.scanmode.prn141",
1979                 FT_UINT32, BASE_HEX, NULL, 0x00200000, NULL, HFILL}},
1980         {&hf_ubx_cfg_sbas_scanmode_prn140,
1981             {"PRN 140", "ubx.cfg.sbas.scanmode.prn140",
1982                 FT_UINT32, BASE_HEX, NULL, 0x00100000, NULL, HFILL}},
1983         {&hf_ubx_cfg_sbas_scanmode_prn139,
1984             {"PRN 139", "ubx.cfg.sbas.scanmode.prn139",
1985                 FT_UINT32, BASE_HEX, NULL, 0x00080000, NULL, HFILL}},
1986         {&hf_ubx_cfg_sbas_scanmode_prn138,
1987             {"PRN 138", "ubx.cfg.sbas.scanmode.prn138",
1988                 FT_UINT32, BASE_HEX, NULL, 0x00040000, NULL, HFILL}},
1989         {&hf_ubx_cfg_sbas_scanmode_prn137,
1990             {"PRN 137", "ubx.cfg.sbas.scanmode.prn137",
1991                 FT_UINT32, BASE_HEX, NULL, 0x00020000, NULL, HFILL}},
1992         {&hf_ubx_cfg_sbas_scanmode_prn136,
1993             {"PRN 136", "ubx.cfg.sbas.scanmode.prn136",
1994                 FT_UINT32, BASE_HEX, NULL, 0x00010000, NULL, HFILL}},
1995         {&hf_ubx_cfg_sbas_scanmode_prn135,
1996             {"PRN 135", "ubx.cfg.sbas.scanmode.prn135",
1997                 FT_UINT32, BASE_HEX, NULL, 0x00008000, NULL, HFILL}},
1998         {&hf_ubx_cfg_sbas_scanmode_prn134,
1999             {"PRN 134", "ubx.cfg.sbas.scanmode.prn134",
2000                 FT_UINT32, BASE_HEX, NULL, 0x00004000, NULL, HFILL}},
2001         {&hf_ubx_cfg_sbas_scanmode_prn133,
2002             {"PRN 133", "ubx.cfg.sbas.scanmode.prn133",
2003                 FT_UINT32, BASE_HEX, NULL, 0x00002000, NULL, HFILL}},
2004         {&hf_ubx_cfg_sbas_scanmode_prn132,
2005             {"PRN 132", "ubx.cfg.sbas.scanmode.prn132",
2006                 FT_UINT32, BASE_HEX, NULL, 0x00001000, NULL, HFILL}},
2007         {&hf_ubx_cfg_sbas_scanmode_prn131,
2008             {"PRN 131", "ubx.cfg.sbas.scanmode.prn131",
2009                 FT_UINT32, BASE_HEX, NULL, 0x00000800, NULL, HFILL}},
2010         {&hf_ubx_cfg_sbas_scanmode_prn130,
2011             {"PRN 130", "ubx.cfg.sbas.scanmode.prn130",
2012                 FT_UINT32, BASE_HEX, NULL, 0x00000400, NULL, HFILL}},
2013         {&hf_ubx_cfg_sbas_scanmode_prn129,
2014             {"PRN 129", "ubx.cfg.sbas.scanmode.prn129",
2015                 FT_UINT32, BASE_HEX, NULL, 0x00000200, NULL, HFILL}},
2016         {&hf_ubx_cfg_sbas_scanmode_prn128,
2017             {"PRN 128", "ubx.cfg.sbas.scanmode.prn128",
2018                 FT_UINT32, BASE_HEX, NULL, 0x00000100, NULL, HFILL}},
2019         {&hf_ubx_cfg_sbas_scanmode_prn127,
2020             {"PRN 127", "ubx.cfg.sbas.scanmode.prn127",
2021                 FT_UINT32, BASE_HEX, NULL, 0x00000080, NULL, HFILL}},
2022         {&hf_ubx_cfg_sbas_scanmode_prn126,
2023             {"PRN 126", "ubx.cfg.sbas.scanmode.prn126",
2024                 FT_UINT32, BASE_HEX, NULL, 0x00000040, NULL, HFILL}},
2025         {&hf_ubx_cfg_sbas_scanmode_prn125,
2026             {"PRN 125", "ubx.cfg.sbas.scanmode.prn125",
2027                 FT_UINT32, BASE_HEX, NULL, 0x00000020, NULL, HFILL}},
2028         {&hf_ubx_cfg_sbas_scanmode_prn124,
2029             {"PRN 124", "ubx.cfg.sbas.scanmode.prn124",
2030                 FT_UINT32, BASE_HEX, NULL, 0x00000010, NULL, HFILL}},
2031         {&hf_ubx_cfg_sbas_scanmode_prn123,
2032             {"PRN 123", "ubx.cfg.sbas.scanmode.prn123",
2033                 FT_UINT32, BASE_HEX, NULL, 0x00000008, NULL, HFILL}},
2034         {&hf_ubx_cfg_sbas_scanmode_prn122,
2035             {"PRN 122", "ubx.cfg.sbas.scanmode.prn122",
2036                 FT_UINT32, BASE_HEX, NULL, 0x00000004, NULL, HFILL}},
2037         {&hf_ubx_cfg_sbas_scanmode_prn121,
2038             {"PRN 121", "ubx.cfg.sbas.scanmode.prn121",
2039                 FT_UINT32, BASE_HEX, NULL, 0x00000002, NULL, HFILL}},
2040         {&hf_ubx_cfg_sbas_scanmode_prn120,
2041             {"PRN 120", "ubx.cfg.sbas.scanmode.prn120",
2042                 FT_UINT32, BASE_HEX, NULL, 0x00000001, NULL, HFILL}},
2043
2044         // NAV-DOP
2045         {&hf_ubx_nav_dop,
2046             {"UBX-NAV-DOP", "ubx.nav.dop",
2047                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
2048         {&hf_ubx_nav_dop_itow,
2049             {"iTOW", "ubx.nav.dop.itow",
2050                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2051         {&hf_ubx_nav_dop_gdop,
2052             {"Geometric DOP", "ubx.nav.dop.gdop",
2053                 FT_UINT16, BASE_CUSTOM, CF_FUNC(&fmt_dop), 0x0, NULL, HFILL}},
2054         {&hf_ubx_nav_dop_pdop,
2055             {"Position DOP", "ubx.nav.dop.pdop",
2056                 FT_UINT16, BASE_CUSTOM, CF_FUNC(&fmt_dop), 0x0, NULL, HFILL}},
2057         {&hf_ubx_nav_dop_tdop,
2058             {"Time DOP", "ubx.nav.dop.tdop",
2059                 FT_UINT16, BASE_CUSTOM, CF_FUNC(&fmt_dop), 0x0, NULL, HFILL}},
2060         {&hf_ubx_nav_dop_vdop,
2061             {"Vertical DOP", "ubx.nav.dop.vdop",
2062                 FT_UINT16, BASE_CUSTOM, CF_FUNC(&fmt_dop), 0x0, NULL, HFILL}},
2063         {&hf_ubx_nav_dop_hdop,
2064             {"Horizontal DOP", "ubx.nav.dop.hdop",
2065                 FT_UINT16, BASE_CUSTOM, CF_FUNC(&fmt_dop), 0x0, NULL, HFILL}},
2066         {&hf_ubx_nav_dop_ndop,
2067             {"Northing DOP", "ubx.nav.dop.ndop",
2068                 FT_UINT16, BASE_CUSTOM, CF_FUNC(&fmt_dop), 0x0, NULL, HFILL}},
2069         {&hf_ubx_nav_dop_edop,
2070             {"Easting DOP", "ubx.nav.dop.edop",
2071                 FT_UINT16, BASE_CUSTOM, CF_FUNC(&fmt_dop), 0x0, NULL, HFILL}},
2072
2073         // NAV-EOE
2074         {&hf_ubx_nav_eoe,
2075             {"UBX-NAV-EOE", "ubx.nav.eoe",
2076                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
2077         {&hf_ubx_nav_eoe_itow,
2078             {"iTOW", "ubx.nav.eoe.itow",
2079                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2080
2081         // NAV-ODO
2082         {&hf_ubx_nav_odo,
2083             {"UBX-NAV-ODO", "ubx.nav.odo",
2084                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
2085         {&hf_ubx_nav_odo_version,
2086             {"Version", "ubx.nav.odo.version",
2087                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2088         {&hf_ubx_nav_odo_reserved1,
2089             {"Reserved", "ubx.nav.odo.reserved1",
2090                 FT_UINT24, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2091         {&hf_ubx_nav_odo_itow,
2092             {"iTOW", "ubx.nav.odo.itow",
2093                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2094         {&hf_ubx_nav_odo_distance,
2095             {"Ground distance since last reset", "ubx.nav.odo.distance",
2096                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_meter_meters), 0x0, NULL, HFILL}},
2097         {&hf_ubx_nav_odo_totaldistance,
2098             {"Total cumulative ground distance", "ubx.nav.odo.totaldistance",
2099                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_meter_meters), 0x0, NULL, HFILL}},
2100         {&hf_ubx_nav_odo_distancestd,
2101             {"Ground distance accuracy (1-sigma)", "ubx.nav.odo.distancestd",
2102                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_meter_meters), 0x0, NULL, HFILL}},
2103
2104         // NAV-POSECEF
2105         {&hf_ubx_nav_posecef,
2106             {"UBX-NAV-POSECEF", "ubx.nav.posecef",
2107                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
2108         {&hf_ubx_nav_posecef_itow,
2109             {"iTOW", "ubx.nav.posecef.itow",
2110                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2111         {&hf_ubx_nav_posecef_ecefx,
2112             {"ECEF X coordinate", "ubx.nav.posecef.ecefx",
2113                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_centimeters), 0x0, NULL, HFILL}},
2114         {&hf_ubx_nav_posecef_ecefy,
2115             {"ECEF Y coordinate", "ubx.nav.posecef.ecefy",
2116                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_centimeters), 0x0, NULL, HFILL}},
2117         {&hf_ubx_nav_posecef_ecefz,
2118             {"ECEF Z coordinate", "ubx.nav.posecef.ecefz",
2119                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_centimeters), 0x0, NULL, HFILL}},
2120         {&hf_ubx_nav_posecef_pacc,
2121             {"Position accuracy estimate", "ubx.nav.posecef.pacc",
2122                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_centimeters), 0x0, NULL, HFILL}},
2123
2124         // NAV-PVT
2125         {&hf_ubx_nav_pvt,
2126             {"UBX-NAV-PVT", "ubx.nav.pvt",
2127                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
2128         {&hf_ubx_nav_pvt_itow,
2129             {"iTOW", "ubx.nav.pvt.itow",
2130                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2131         {&hf_ubx_nav_pvt_year,
2132             {"Year", "ubx.nav.pvt.year",
2133                 FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2134         {&hf_ubx_nav_pvt_month,
2135             {"Month", "ubx.nav.pvt.month",
2136                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2137         {&hf_ubx_nav_pvt_day,
2138             {"Day", "ubx.nav.pvt.day",
2139                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2140         {&hf_ubx_nav_pvt_hour,
2141             {"Hour", "ubx.nav.pvt.hour",
2142                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2143         {&hf_ubx_nav_pvt_min,
2144             {"Minute", "ubx.nav.pvt.min",
2145                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2146         {&hf_ubx_nav_pvt_sec,
2147             {"Seconds", "ubx.nav.pvt.sec",
2148                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2149         {&hf_ubx_nav_pvt_valid,
2150             {"Validity flags", "ubx.nav.pvt.valid",
2151                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2152         {&hf_ubx_nav_pvt_validmag,
2153             {"Valid magnetic declination", "ubx.nav.pvt.valid.validmag",
2154                 FT_BOOLEAN, 8, NULL, 0x08, NULL, HFILL}},
2155         {&hf_ubx_nav_pvt_fullyresolved,
2156             {"UTC time of day fully resolved", "ubx.nav.pvt.valid.fullyresolved",
2157                 FT_BOOLEAN, 8, NULL, 0x04, NULL, HFILL}},
2158         {&hf_ubx_nav_pvt_validtime,
2159             {"valid UTC time of day", "ubx.nav.pvt.valid.validtime",
2160                 FT_BOOLEAN, 8, NULL, 0x02, NULL, HFILL}},
2161         {&hf_ubx_nav_pvt_validdate,
2162             {"valid UTC date", "ubx.nav.pvt.valid.validdate",
2163                 FT_BOOLEAN, 8, NULL, 0x01, NULL, HFILL}},
2164         {&hf_ubx_nav_pvt_tacc,
2165             {"Time accuracy estimate", "ubx.nav.pvt.tacc",
2166                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_nanoseconds), 0x0, NULL, HFILL}},
2167         {&hf_ubx_nav_pvt_nano,
2168             {"UTC fraction of second", "ubx.nav.pvt.nano",
2169                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_nanoseconds), 0x0, NULL, HFILL}},
2170         {&hf_ubx_nav_pvt_fixtype,
2171             {"GNSS fix type", "ubx.nav.pvt.fixtype",
2172                 FT_UINT8, BASE_DEC, VALS(UBX_GNSS_FIX_TYPE), 0x0, NULL, HFILL}},
2173         {&hf_ubx_nav_pvt_flags,
2174             {"Fix status flags", "ubx.nav.pvt.flags",
2175                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2176         {&hf_ubx_nav_pvt_headvehvalid,
2177             {"heading of vehicle is valid", "ubx.nav.pvt.flags.headvehvalid",
2178                 FT_BOOLEAN, 8, NULL, 0x20, NULL, HFILL}},
2179         {&hf_ubx_nav_pvt_psmstate,
2180             {"PSM state", "ubx.nav.pvt.flags.psmstate",
2181                 FT_UINT8, BASE_DEC, NULL, 0x1c, NULL, HFILL}},
2182         {&hf_ubx_nav_pvt_diffsoln,
2183             {"differential corrections were applied", "ubx.nav.pvt.flags.diffsoln",
2184                 FT_BOOLEAN, 8, NULL, 0x02, NULL, HFILL}},
2185         {&hf_ubx_nav_pvt_gnssfixok,
2186             {"valid fix", "ubx.nav.pvt.flags.gnssfixok",
2187                 FT_BOOLEAN, 8, NULL, 0x01, NULL, HFILL}},
2188         {&hf_ubx_nav_pvt_flags2,
2189             {"Additional flags", "ubx.nav.pvt.flags2",
2190                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2191         {&hf_ubx_nav_pvt_confirmedtime,
2192             {"UTC time of day could be confirmed", "ubx.nav.pvt.flags2.confirmedtime",
2193                 FT_BOOLEAN, 8, NULL, 0x80, NULL, HFILL}},
2194         {&hf_ubx_nav_pvt_confirmeddate,
2195             {"UTC date could be validated", "ubx.nav.pvt.flags2.confirmeddate",
2196                 FT_BOOLEAN, 8, NULL, 0x40, NULL, HFILL}},
2197         {&hf_ubx_nav_pvt_confirmedavai,
2198             {"information about UTC date and time of day validity confirmation is available", "ubx.nav.pvt.flags2.confirmedavai",
2199                 FT_BOOLEAN, 8, NULL, 0x20, NULL, HFILL}},
2200         {&hf_ubx_nav_pvt_numsv,
2201             {"Number of satellite vehicles used in Nav solution", "ubx.nav.pvt.numsv",
2202                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2203         {&hf_ubx_nav_pvt_lon,
2204             {"Longitude", "ubx.nav.pvt.lon",
2205                 FT_INT32, BASE_CUSTOM, CF_FUNC(&fmt_lat_lon), 0x0, NULL, HFILL}},
2206         {&hf_ubx_nav_pvt_lat,
2207             {"Latitude", "ubx.nav.pvt.lat",
2208                 FT_INT32, BASE_CUSTOM, CF_FUNC(&fmt_lat_lon), 0x0, NULL, HFILL}},
2209         {&hf_ubx_nav_pvt_height,
2210             {"Height above ellipsoid", "ubx.nav.pvt.height",
2211                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_millimeters), 0x0, NULL, HFILL}},
2212         {&hf_ubx_nav_pvt_hmsl,
2213             {"Height above mean sea level", "ubx.nav.pvt.hmsl",
2214                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_millimeters), 0x0, NULL, HFILL}},
2215         {&hf_ubx_nav_pvt_hacc,
2216             {"Horizontal accuracy estimate", "ubx.nav.pvt.hacc",
2217                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_millimeters), 0x0, NULL, HFILL}},
2218         {&hf_ubx_nav_pvt_vacc,
2219             {"Vertical accuracy estimate", "ubx.nav.pvt.vacc",
2220                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_millimeters), 0x0, NULL, HFILL}},
2221         {&hf_ubx_nav_pvt_veln,
2222             {"NED north velocity", "ubx.nav.pvt.veln",
2223                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_mm_s), 0x0, NULL, HFILL}},
2224         {&hf_ubx_nav_pvt_vele,
2225             {"NED east velocity", "ubx.nav.pvt.vele",
2226                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_mm_s), 0x0, NULL, HFILL}},
2227         {&hf_ubx_nav_pvt_veld,
2228             {"NED down velocity", "ubx.nav.pvt.veld",
2229                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_mm_s), 0x0, NULL, HFILL}},
2230         {&hf_ubx_nav_pvt_gspeed,
2231             {"Ground speed (2-D)", "ubx.nav.pvt.gspeed",
2232                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_mm_s), 0x0, NULL, HFILL}},
2233         {&hf_ubx_nav_pvt_headmot,
2234             {"Heading of motion (2-D)", "ubx.nav.pvt.headmot",
2235                 FT_INT32, BASE_CUSTOM, CF_FUNC(&fmt_heading), 0x0, NULL, HFILL}},
2236         {&hf_ubx_nav_pvt_sacc,
2237             {"Speed accuracy estimate", "ubx.nav.pvt.sacc",
2238                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_mm_s), 0x0, NULL, HFILL}},
2239         {&hf_ubx_nav_pvt_headacc,
2240             {"Heading accuracy estimate", "ubx.nav.pvt.headacc",
2241                 FT_UINT32, BASE_CUSTOM, CF_FUNC(&fmt_heading_acc), 0x0, NULL, HFILL}},
2242         {&hf_ubx_nav_pvt_pdop,
2243             {"Position DOP", "ubx.nav.pvt.pdop",
2244                 FT_UINT16, BASE_CUSTOM, CF_FUNC(&fmt_dop), 0x0, NULL, HFILL}},
2245         {&hf_ubx_nav_pvt_lastcorrectionage,
2246             {"Age of the most recently received differential correction", "ubx.nav.pvt.lastcorrectionage",
2247                 FT_UINT16, BASE_DEC, VALS(UBX_LAST_CORRECTION_AGE), 0x001e, NULL, HFILL}},
2248         {&hf_ubx_nav_pvt_invalidllh,
2249             {"Invalid lon, lat, height, and hMSL", "ubx.nav.pvt.invalidllh",
2250                 FT_BOOLEAN, 16, NULL, 0x0001, NULL, HFILL}},
2251         {&hf_ubx_nav_pvt_reserved1,
2252             {"Reserved 1", "ubx.nav.pvt.reserved1",
2253                 FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2254         {&hf_ubx_nav_pvt_headveh,
2255             {"Heading of vehicle (2-D)", "ubx.nav.pvt.headveh",
2256                 FT_INT32, BASE_CUSTOM, CF_FUNC(&fmt_heading), 0x0, NULL, HFILL}},
2257         {&hf_ubx_nav_pvt_magdec,
2258             {"Magnetic declination", "ubx.nav.pvt.magdec",
2259                 FT_INT16, BASE_CUSTOM, CF_FUNC(&fmt_decl), 0x0, NULL, HFILL}},
2260         {&hf_ubx_nav_pvt_magacc,
2261             {"Magnetic declination accuracy", "ubx.nav.pvt.magacc",
2262                 FT_UINT16, BASE_CUSTOM, CF_FUNC(&fmt_decl_acc), 0x0, NULL, HFILL}},
2263
2264         // NAV-SAT
2265         {&hf_ubx_nav_sat,
2266             {"UBX-NAV-SAT", "ubx.nav.sat",
2267                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
2268         {&hf_ubx_nav_sat_itow,
2269             {"iTOW", "ubx.nav.sat.itow",
2270                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2271         {&hf_ubx_nav_sat_version,
2272             {"Version", "ubx.nav.sat.version",
2273                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2274         {&hf_ubx_nav_sat_num_svs,
2275             {"Number of satellites", "ubx.nav.sat.num_svs",
2276                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2277         {&hf_ubx_nav_sat_reserved1,
2278             {"Reserved", "ubx.nav.sat.reserved1",
2279                 FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2280         {&hf_ubx_nav_sat_gnss_id,
2281             {"GNSS ID", "ubx.nav.sat.gnss_id",
2282                 FT_UINT8, BASE_DEC, VALS(UBX_GNSS_ID), 0x0, NULL, HFILL}},
2283         {&hf_ubx_nav_sat_sv_id,
2284             {"SV ID", "ubx.nav.sat.sv_id",
2285                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2286         {&hf_ubx_nav_sat_cn0,
2287             {"C/N0", "ubx.nav.sat.cn0",
2288                 FT_UINT8, BASE_DEC|BASE_UNIT_STRING, UNS(&units_dbhz), 0x0, NULL, HFILL}},
2289         {&hf_ubx_nav_sat_elev,
2290             {"Elevation", "ubx.nav.sat.elev",
2291                 FT_INT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2292         {&hf_ubx_nav_sat_azim,
2293             {"Azimuth", "ubx.nav.sat.azim",
2294                 FT_INT16, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2295         {&hf_ubx_nav_sat_pr_res,
2296             {"Pseudorange residual", "ubx.nav.sat.pr_res",
2297                 FT_INT16, BASE_CUSTOM, CF_FUNC(&fmt_pr_res), 0x0, NULL, HFILL}},
2298         {&hf_ubx_nav_sat_flags,
2299             {"Bitmask", "ubx.nav.sat.flags",
2300                 FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2301         {&hf_ubx_nav_sat_quality_ind,
2302             {"Signal quality indicator", "ubx.nav.sat.flags.quality_ind",
2303                 FT_UINT32, BASE_HEX, VALS(UBX_SIGNAL_QUALITY_INDICATOR), 0x00000007, NULL, HFILL}},
2304         {&hf_ubx_nav_sat_sv_used,
2305             {"Signal used for navigation", "ubx.nav.sat.flags.sv_used",
2306                 FT_UINT32, BASE_HEX, NULL, 0x00000008, NULL, HFILL}},
2307         {&hf_ubx_nav_sat_health,
2308             {"Signal health", "ubx.nav.sat.flags.health",
2309                 FT_UINT32, BASE_HEX, VALS(UBX_SIGNAL_HEALTH), 0x00000030, NULL, HFILL}},
2310         {&hf_ubx_nav_sat_diff_corr,
2311             {"Differential correction available", "ubx.nav.sat.flags.diff_corr",
2312                 FT_UINT32, BASE_HEX, NULL, 0x00000040, NULL, HFILL}},
2313         {&hf_ubx_nav_sat_smoothed,
2314             {"Carrier smoothed pseudorange used", "ubx.nav.sat.flags.smoothed",
2315                 FT_UINT32, BASE_HEX, NULL, 0x00000080, NULL, HFILL}},
2316         {&hf_ubx_nav_sat_orbit_src,
2317             {"Orbit source", "ubx.nav.sat.flags.orbit_src",
2318                 FT_UINT32, BASE_HEX, VALS(UBX_ORBIT_SOURCE), 0x00000700, NULL, HFILL}},
2319         {&hf_ubx_nav_sat_eph_avail,
2320             {"Ephemeris available", "ubx.nav.sat.flags.eph_avail",
2321                 FT_UINT32, BASE_HEX, NULL, 0x00000800, NULL, HFILL}},
2322         {&hf_ubx_nav_sat_alm_avail,
2323             {"Almanac available", "ubx.nav.sat.flags.alm_avail",
2324                 FT_UINT32, BASE_HEX, NULL, 0x00001000, NULL, HFILL}},
2325         {&hf_ubx_nav_sat_ano_avail,
2326             {"AssistNow Offline data available", "ubx.nav.sat.flags.ano_avail",
2327                 FT_UINT32, BASE_HEX, NULL, 0x00002000, NULL, HFILL}},
2328         {&hf_ubx_nav_sat_aop_avail,
2329             {"AssistNow Autonomous data available", "ubx.nav.sat.flags.aop_avail",
2330                 FT_UINT32, BASE_HEX, NULL, 0x00004000, NULL, HFILL}},
2331         {&hf_ubx_nav_sat_sbas_corr_used,
2332             {"SBAS corrections used", "ubx.nav.sat.flags.sbas_corr_used",
2333                 FT_UINT32, BASE_HEX, NULL, 0x00010000, NULL, HFILL}},
2334         {&hf_ubx_nav_sat_rtcm_corr_used,
2335             {"RTCM corrections used", "ubx.nav.sat.flags.rtcm_corr_used",
2336                 FT_UINT32, BASE_HEX, NULL, 0x00020000, NULL, HFILL}},
2337         {&hf_ubx_nav_sat_slas_corr_used,
2338             {"QZSS SLAS corrections used", "ubx.nav.sat.flags.slas_corr_used",
2339                 FT_UINT32, BASE_HEX, NULL, 0x00040000, NULL, HFILL}},
2340         {&hf_ubx_nav_sat_spartn_corr_used,
2341             {"SPARTN corrections used", "ubx.nav.sat.flags.spartn_corr_used",
2342                 FT_UINT32, BASE_HEX, NULL, 0x00080000, NULL, HFILL}},
2343         {&hf_ubx_nav_sat_pr_corr_used,
2344             {"Pseudorange corrections used", "ubx.nav.sat.flags.pr_corr_used",
2345                 FT_UINT32, BASE_HEX, NULL, 0x00100000, NULL, HFILL}},
2346         {&hf_ubx_nav_sat_cr_corr_used,
2347             {"Carrier range corrections used", "ubx.nav.sat.flags.cr_corr_used",
2348                 FT_UINT32, BASE_HEX, NULL, 0x00200000, NULL, HFILL}},
2349         {&hf_ubx_nav_sat_do_corr_used,
2350             {"Range rate (Doppler) corrections used", "ubx.nav.sat.flags.do_corr_used",
2351                 FT_UINT32, BASE_HEX, NULL, 0x00400000, NULL, HFILL}},
2352
2353         // NAV-SBAS
2354         {&hf_ubx_nav_sbas,
2355             {"UBX-NAV-SBAS", "ubx.nav.sbas",
2356                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
2357         {&hf_ubx_nav_sbas_itow,
2358             {"iTOW", "ubx.nav.sbas.itow",
2359                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2360         {&hf_ubx_nav_sbas_geo,
2361             {"GEO PRN", "ubx.nav.sbas.geo",
2362                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2363         {&hf_ubx_nav_sbas_mode,
2364             {"SBAS Mode", "ubx.nav.sbas.mode",
2365                 FT_UINT8, BASE_DEC, VALS(UBX_SBAS_MODE), 0x0, NULL, HFILL}},
2366         {&hf_ubx_nav_sbas_sys,
2367             {"SBAS System", "ubx.nav.sbas.sys",
2368                 FT_INT8, BASE_DEC, VALS(UBX_SBAS_SYSTEM), 0x0, NULL, HFILL}},
2369         {&hf_ubx_nav_sbas_service,
2370             {"SBAS Services available", "ubx.nav.sbas.service",
2371                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2372         {&hf_ubx_nav_sbas_service_ranging,
2373             {"GEO may be used as ranging source", "ubx.nav.sbas.service.ranging",
2374                 FT_BOOLEAN, 8, NULL, 0x01, NULL, HFILL}},
2375         {&hf_ubx_nav_sbas_service_corrections,
2376             {"GEO is providing correction data", "ubx.nav.sbas.service.corrections",
2377                 FT_BOOLEAN, 8, NULL, 0x02, NULL, HFILL}},
2378         {&hf_ubx_nav_sbas_service_integrity,
2379             {"GEO is providing integrity", "ubx.nav.sbas.service.integrity",
2380                 FT_BOOLEAN, 8, NULL, 0x04, NULL, HFILL}},
2381         {&hf_ubx_nav_sbas_service_testmode,
2382             {"GEO is in test mode", "ubx.nav.sbas.service.testmode",
2383                 FT_BOOLEAN, 8, NULL, 0x08, NULL, HFILL}},
2384         {&hf_ubx_nav_sbas_service_bad,
2385             {"Problem with signal or broadcast data indicated", "ubx.nav.sbas.service.bad",
2386                 FT_BOOLEAN, 8, NULL, 0x10, NULL, HFILL}},
2387         {&hf_ubx_nav_sbas_cnt,
2388             {"Number of SV data following", "ubx.nav.sbas.cnt",
2389                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2390         {&hf_ubx_nav_sbas_reserved1,
2391             {"Reserved", "ubx.nav.sbas.reserved1",
2392                 FT_UINT24, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2393         {&hf_ubx_nav_sbas_sv_id,
2394             {"SV ID", "ubx.nav.sbas.sv_id",
2395                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2396         {&hf_ubx_nav_sbas_flags,
2397             {"Flags", "ubx.nav.sbas.flags",
2398                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2399         {&hf_ubx_nav_sbas_udre,
2400             {"Monitoring status", "ubx.nav.sbas.udre",
2401                 FT_UINT8, BASE_DEC, VALS(UDREI_EVALUATION), 0x0, NULL, HFILL}},
2402         {&hf_ubx_nav_sbas_sv_sys,
2403             {"System", "ubx.nav.sbas.sv_sys",
2404                 FT_INT8, BASE_DEC, VALS(UBX_SBAS_SYSTEM), 0x0, NULL, HFILL}},
2405         {&hf_ubx_nav_sbas_sv_service,
2406             {"Service", "ubx.nav.sbas.sv_service",
2407                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2408         {&hf_ubx_nav_sbas_reserved2,
2409             {"Reserved", "ubx.nav.sbas.reserved2",
2410                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2411         {&hf_ubx_nav_sbas_prc,
2412             {"Pseudo Range correction", "ubx.nav.sbas.prc",
2413                 FT_INT16, BASE_DEC|BASE_UNIT_STRING, UNS(&units_centimeter_centimeters), 0x0, NULL, HFILL}},
2414         {&hf_ubx_nav_sbas_reserved3,
2415             {"Reserved", "ubx.nav.sbas.reserved3",
2416                 FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2417         {&hf_ubx_nav_sbas_ic,
2418             {"Ionosphere correction", "ubx.nav.sbas.ic",
2419                 FT_INT16, BASE_DEC|BASE_UNIT_STRING, UNS(&units_centimeter_centimeters), 0x0, NULL, HFILL}},
2420
2421         // NAV-TIMEGPS
2422         {&hf_ubx_nav_timegps,
2423             {"UBX-NAV-TIMEGPS", "ubx.nav.timegps",
2424                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
2425         {&hf_ubx_nav_timegps_itow,
2426             {"iTOW", "ubx.nav.timegps.itow",
2427                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2428         {&hf_ubx_nav_timegps_ftow,
2429             {"fTOW", "ubx.nav.timegps.ftow",
2430                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_nanoseconds), 0x0, NULL, HFILL}},
2431         {&hf_ubx_nav_timegps_week,
2432             {"GPS week", "ubx.nav.timegps.week",
2433                 FT_INT16, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2434         {&hf_ubx_nav_timegps_leaps,
2435             {"GPS leap seconds", "ubx.nav.timegps.leaps",
2436                 FT_INT8, BASE_DEC|BASE_UNIT_STRING, UNS(&units_seconds), 0x0, NULL, HFILL}},
2437         {&hf_ubx_nav_timegps_valid,
2438             {"Validity flags", "ubx.nav.timegps.valid",
2439                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2440         {&hf_ubx_nav_timegps_towvalid,
2441             {"Valid GPS time of week", "ubx.nav.timegps.valid.towvalid",
2442                 FT_BOOLEAN, 8, NULL, 0x01, NULL, HFILL}},
2443         {&hf_ubx_nav_timegps_weekvalid,
2444             {"Valid GPS week number", "ubx.nav.timegps.valid.weekvalid",
2445                 FT_BOOLEAN, 8, NULL, 0x02, NULL, HFILL}},
2446         {&hf_ubx_nav_timegps_leapsvalid,
2447             {"Valid GPS leap seconds", "ubx.nav.timegps.valid.leapsvalid",
2448                 FT_BOOLEAN, 8, NULL, 0x04, NULL, HFILL}},
2449         {&hf_ubx_nav_timegps_tacc,
2450             {"Time accuracy estimate", "ubx.nav.timegps.tacc",
2451                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_seconds), 0x0, NULL, HFILL}},
2452
2453         // NAV-TIMEUTC
2454         {&hf_ubx_nav_timeutc,
2455             {"UBX-NAV-TIMEUTC", "ubx.nav.timeutc",
2456                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
2457         {&hf_ubx_nav_timeutc_itow,
2458             {"iTOW", "ubx.nav.timeutc.itow",
2459                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2460         {&hf_ubx_nav_timeutc_tacc,
2461             {"Time accuracy estimate (UTC)", "ubx.nav.timeutc.tacc",
2462                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_nanoseconds), 0x0, NULL, HFILL}},
2463         {&hf_ubx_nav_timeutc_nano,
2464             {"Fraction of second (UTC)", "ubx.nav.timeutc.nano",
2465                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_nanoseconds), 0x0, NULL, HFILL}},
2466         {&hf_ubx_nav_timeutc_year,
2467             {"Year", "ubx.nav.timeutc.year",
2468                 FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2469         {&hf_ubx_nav_timeutc_month,
2470             {"Month", "ubx.nav.timeutc.month",
2471                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2472         {&hf_ubx_nav_timeutc_day,
2473             {"Day", "ubx.nav.timeutc.day",
2474                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2475         {&hf_ubx_nav_timeutc_hour,
2476             {"Hour of day", "ubx.nav.timeutc.hour",
2477                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2478         {&hf_ubx_nav_timeutc_min,
2479             {"Minute of hour", "ubx.nav.timeutc.min",
2480                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2481         {&hf_ubx_nav_timeutc_sec,
2482             {"Seconds of minute", "ubx.nav.timeutc.sec",
2483                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2484         {&hf_ubx_nav_timeutc_valid,
2485             {"Validity flags", "ubx.nav.timeutc.valid",
2486                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2487         {&hf_ubx_nav_timeutc_validtow,
2488             {"Valid Time of Week", "ubx.nav.timeutc.valid.validtow",
2489                 FT_BOOLEAN, 8, NULL, 0x01, NULL, HFILL}},
2490         {&hf_ubx_nav_timeutc_validwkn,
2491             {"Valid Week Number", "ubx.nav.timeutc.valid.validwkn",
2492                 FT_BOOLEAN, 8, NULL, 0x02, NULL, HFILL}},
2493         {&hf_ubx_nav_timeutc_validutc,
2494             {"Valid UTC Time", "ubx.nav.timeutc.valid.validutc",
2495                 FT_BOOLEAN, 8, NULL, 0x04, NULL, HFILL}},
2496         {&hf_ubx_nav_timeutc_utcstandard,
2497             {"utcStandard", "ubx.nav.timeutc.valid.utcstandard",
2498                 FT_UINT8, BASE_DEC, VALS(UBX_UTC_STD_ID), 0xf0, NULL, HFILL}},
2499
2500         // NAV-VELECEF
2501         {&hf_ubx_nav_velecef,
2502             {"UBX-NAV-VELECEF", "ubx.nav.velecef",
2503                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
2504         {&hf_ubx_nav_velecef_itow,
2505             {"iTOW", "ubx.nav.velecef.itow",
2506                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_seconds), 0x0, NULL, HFILL}},
2507         {&hf_ubx_nav_velecef_ecefvx,
2508             {"ECEF X velocity", "ubx.nav.velecef.ecefvx",
2509                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_cm_s), 0x0, NULL, HFILL}},
2510         {&hf_ubx_nav_velecef_ecefvy,
2511             {"ECEF Y velocity", "ubx.nav.velecef.ecefvy",
2512                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_cm_s), 0x0, NULL, HFILL}},
2513         {&hf_ubx_nav_velecef_ecefvz,
2514             {"ECEF Z velocity", "ubx.nav.velecef.ecefvz",
2515                 FT_INT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_cm_s), 0x0, NULL, HFILL}},
2516         {&hf_ubx_nav_velecef_sacc,
2517             {"Speed accuracy estimate", "ubx.nav.velecef.sacc",
2518                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_cm_s), 0x0, NULL, HFILL}},
2519
2520         // RXM-MEASX
2521         {&hf_ubx_rxm_measx,
2522             {"UBX-RXM-MEASX", "ubx.rxm.measx",
2523                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
2524         {&hf_ubx_rxm_measx_version,
2525             {"Message version", "ubx.rxm.measx.version",
2526                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2527         {&hf_ubx_rxm_measx_reserved1,
2528             {"Reserved", "ubx.rxm.measx.reserved1",
2529                 FT_UINT24, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2530         {&hf_ubx_rxm_measx_gpstow,
2531             {"GPS measurement reference time", "ubx.rxm.measx.gpstow",
2532                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2533         {&hf_ubx_rxm_measx_glotow,
2534             {"GLONASS measurement reference time", "ubx.rxm.measx.glotow",
2535                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2536         {&hf_ubx_rxm_measx_bdstow,
2537             {"BeiDou measurement reference time", "ubx.rxm.measx.bdstow",
2538                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2539         {&hf_ubx_rxm_measx_reserved2,
2540             {"Reserved", "ubx.rxm.measx.reserved2",
2541                 FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2542         {&hf_ubx_rxm_measx_qzsstow,
2543             {"QZSS measurement reference time", "ubx.rxm.measx.qzsstow",
2544                 FT_UINT32, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2545         {&hf_ubx_rxm_measx_gpstowacc,
2546             {"GPS measurement reference time accuracy", "ubx.rxm.measx.gpstowacc",
2547                 FT_UINT16, BASE_CUSTOM, CF_FUNC(&fmt_towacc), 0x0, NULL, HFILL}},
2548         {&hf_ubx_rxm_measx_glotowacc,
2549             {"GLONASS measurement reference time accuracy", "ubx.rxm.measx.glotowacc",
2550                 FT_UINT16, BASE_CUSTOM, CF_FUNC(&fmt_towacc), 0x0, NULL, HFILL}},
2551         {&hf_ubx_rxm_measx_bdstowacc,
2552             {"BeiDou measurement reference time accuracy", "ubx.rxm.measx.bdstowacc",
2553                 FT_UINT16, BASE_CUSTOM, CF_FUNC(&fmt_towacc), 0x0, NULL, HFILL}},
2554         {&hf_ubx_rxm_measx_reserved3,
2555             {"Reserved", "ubx.rxm.measx.reserved3",
2556                 FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2557         {&hf_ubx_rxm_measx_qzsstowacc,
2558             {"QZSS measurement reference time accuracy", "ubx.rxm.measx.qzsstowacc",
2559                 FT_UINT16, BASE_CUSTOM, CF_FUNC(&fmt_towacc), 0x0, NULL, HFILL}},
2560         {&hf_ubx_rxm_measx_numsv,
2561             {"Number of satellites in repeated block", "ubx.rxm.measx.numsv",
2562                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2563         {&hf_ubx_rxm_measx_flags_towset,
2564             {"TOW set", "ubx.rxm.measx.flags.towset",
2565                 FT_BOOLEAN, 8, NULL, 0x03, NULL, HFILL}},
2566         {&hf_ubx_rxm_measx_reserved4,
2567             {"Reserved", "ubx.rxm.measx.reserved4",
2568                 FT_UINT64, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2569         {&hf_ubx_rxm_measx_gnssid,
2570             {"GNSS ID", "ubx.rxm.measx.gnssid",
2571                 FT_UINT8, BASE_DEC, VALS(UBX_GNSS_ID), 0x0, NULL, HFILL}},
2572         {&hf_ubx_rxm_measx_svid,
2573             {"Satellite ID", "ubx.rxm.measx.svid",
2574                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2575         {&hf_ubx_rxm_measx_cn0,
2576             {"C/N0", "ubx.rxm.measx.cn0",
2577                 FT_UINT8, BASE_DEC|BASE_UNIT_STRING, UNS(&units_dbhz), 0x0, NULL, HFILL}},
2578         {&hf_ubx_rxm_measx_mpathindic,
2579             {"multipath index", "ubx.rxm.measx.mpathindic",
2580                 FT_UINT8, BASE_DEC, VALS(UBX_RXM_MEASX_MULTIPATH_INDEX), 0x0, NULL, HFILL}},
2581         {&hf_ubx_rxm_measx_dopplerms,
2582             {"Doppler measurement", "ubx.rxm.measx.dopplerms",
2583                 FT_INT32, BASE_CUSTOM, CF_FUNC(&fmt_dopplerms), 0x0, NULL, HFILL}},
2584         {&hf_ubx_rxm_measx_dopplerhz,
2585             {"Doppler measurement", "ubx.rxm.measx.dopplerhz",
2586                 FT_INT32, BASE_CUSTOM, CF_FUNC(&fmt_dopplerhz), 0x0, NULL, HFILL}},
2587         {&hf_ubx_rxm_measx_wholechips,
2588             {"whole value of the code phase measurement", "ubx.rxm.measx.wholechips",
2589                 FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2590         {&hf_ubx_rxm_measx_fracchips,
2591             {"fractional value of the code phase measurement", "ubx.rxm.measx.fracchips",
2592                 FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2593         {&hf_ubx_rxm_measx_codephase,
2594             {"Code phase", "ubx.rxm.measx.codephase",
2595                 FT_UINT32, BASE_CUSTOM, CF_FUNC(&fmt_codephase), 0x0, NULL, HFILL}},
2596         {&hf_ubx_rxm_measx_intcodephase,
2597             {"integer (part of) the code phase", "ubx.rxm.measx.intcodephase",
2598                 FT_UINT8, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2599         {&hf_ubx_rxm_measx_pseurangermserr,
2600             {"pseudorange RMS error index", "ubx.rxm.measx.pseurangermserr",
2601                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2602         {&hf_ubx_rxm_measx_reserved5,
2603             {"Reserved", "ubx.rxm.measx.reserved5",
2604                 FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2605
2606         // RXM-RAWX
2607         {&hf_ubx_rxm_rawx,
2608             {"UBX-RXM-RAWX", "ubx.rxm.rawx",
2609                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
2610         {&hf_ubx_rxm_rawx_rcvtow,
2611             {"Measurement time of week in receiver local time", "ubx.rxm.rawx.rcvtow",
2612                 FT_DOUBLE, BASE_DEC|BASE_UNIT_STRING, UNS(&units_seconds), 0x0, NULL, HFILL}},
2613         {&hf_ubx_rxm_rawx_week,
2614             {"GPS week number in receiver local time", "ubx.rxm.rawx.week",
2615                 FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2616         {&hf_ubx_rxm_rawx_leaps,
2617             {"GPS leap seconds", "ubx.rxm.rawx.leaps",
2618                 FT_INT8, BASE_DEC|BASE_UNIT_STRING, UNS(&units_seconds), 0x0, NULL, HFILL}},
2619         {&hf_ubx_rxm_rawx_nummeas,
2620             {"Number of measurements to follow", "ubx.rxm.rawx.nummeas",
2621                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2622         {&hf_ubx_rxm_rawx_recstat,
2623             {"Receiver tracking status bitfield", "ubx.rxm.rawx.recstat",
2624                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2625         {&hf_ubx_rxm_rawx_recstat_leapsec,
2626             {"Leap seconds have been determined", "ubx.rxm.rawx.recstat.leapsec",
2627                 FT_BOOLEAN, 8, NULL, 0x01, NULL, HFILL}},
2628         {&hf_ubx_rxm_rawx_recstat_clkreset,
2629             {"Clock reset applied", "ubx.rxm.rawx.recstat.clkreset",
2630                 FT_BOOLEAN, 8, NULL, 0x02, NULL, HFILL}},
2631         {&hf_ubx_rxm_rawx_version,
2632             {"Message version", "ubx.rxm.rawx.version",
2633                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2634         {&hf_ubx_rxm_rawx_reserved1,
2635             {"Reserved", "ubx.rxm.rawx.reserved1",
2636                 FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2637         {&hf_ubx_rxm_rawx_prmes,
2638             {"Pseudorange measurement", "ubx.rxm.rawx.prmes",
2639                 FT_DOUBLE, BASE_DEC|BASE_UNIT_STRING, UNS(&units_meter_meters), 0x0, NULL, HFILL}},
2640         {&hf_ubx_rxm_rawx_cpmes,
2641             {"Carrier phase measurement", "ubx.rxm.rawx.cpmes",
2642                 FT_DOUBLE, BASE_DEC|BASE_UNIT_STRING, UNS(&units_cycle_cycles), 0x0, NULL, HFILL}},
2643         {&hf_ubx_rxm_rawx_domes,
2644             {"Doppler measurement", "ubx.rxm.rawx.domes",
2645                 FT_FLOAT, BASE_DEC|BASE_UNIT_STRING, UNS(&units_hz), 0x0, NULL, HFILL}},
2646         {&hf_ubx_rxm_rawx_gnssid,
2647             {"GNSS ID", "ubx.rxm.rawx.gnssid",
2648                 FT_UINT8, BASE_DEC, VALS(UBX_GNSS_ID), 0x0, NULL, HFILL}},
2649         {&hf_ubx_rxm_rawx_svid,
2650             {"Satellite ID", "ubx.rxm.rawx.svid",
2651                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2652         {&hf_ubx_rxm_rawx_sigid,
2653             {"Signal ID", "ubx.rxm.rawx.sigid",
2654                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2655         {&hf_ubx_rxm_rawx_freqid,
2656             {"Frequency ID", "ubx.rxm.rawx.freqid",
2657                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2658         {&hf_ubx_rxm_rawx_locktime,
2659             {"Carrier phase locktime counter", "ubx.rxm.rawx.locktime",
2660                 FT_UINT16, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x0, NULL, HFILL}},
2661         {&hf_ubx_rxm_rawx_cn0,
2662             {"C/N0", "ubx.rxm.rawx.cn0",
2663                 FT_UINT8, BASE_DEC|BASE_UNIT_STRING, UNS(&units_dbhz), 0x0, NULL, HFILL}},
2664         {&hf_ubx_rxm_rawx_prstdev,
2665             {"Estimated pseudorange measurement standard deviation", "ubx.rxm.rawx.prstdev",
2666                 FT_UINT8, BASE_CUSTOM, CF_FUNC(&fmt_prstdev), 0x0f, NULL, HFILL}},
2667         {&hf_ubx_rxm_rawx_cpstdev,
2668             {"Estimated carrier phase measurement standard deviation", "ubx.rxm.rawx.cpstdev",
2669                 FT_UINT8, BASE_CUSTOM, CF_FUNC(&fmt_cpstdev), 0x0f, NULL, HFILL}},
2670         {&hf_ubx_rxm_rawx_dostdev,
2671             {"Estimated Doppler measurement standard deviation", "ubx.rxm.rawx.dostdev",
2672                 FT_UINT8, BASE_CUSTOM, CF_FUNC(&fmt_dostdev), 0x0f, NULL, HFILL}},
2673         {&hf_ubx_rxm_rawx_trkstat,
2674             {"Tracking status bitfield", "ubx.rxm.rawx.trkstat",
2675                 FT_UINT8, BASE_HEX, NULL, 0x0f, NULL, HFILL}},
2676         {&hf_ubx_rxm_rawx_trkstat_prvalid,
2677             {"Pseudorange valid", "ubx.rxm.rawx.trkstat.prvalid",
2678                 FT_BOOLEAN, 8, NULL, 0x01, NULL, HFILL}},
2679         {&hf_ubx_rxm_rawx_trkstat_cpvalid,
2680             {"Carrier phase valid", "ubx.rxm.rawx.trkstat.cpvalid",
2681                 FT_BOOLEAN, 8, NULL, 0x02, NULL, HFILL}},
2682         {&hf_ubx_rxm_rawx_trkstat_halfcyc,
2683             {"Half cycle valid", "ubx.rxm.rawx.trkstat.halfcyc",
2684                 FT_BOOLEAN, 8, NULL, 0x04, NULL, HFILL}},
2685         {&hf_ubx_rxm_rawx_trkstat_subhalfcyc,
2686             {"Half cycle subtracted from phase", "ubx.rxm.rawx.trkstat.subhalfcyc",
2687                 FT_BOOLEAN, 8, NULL, 0x08, NULL, HFILL}},
2688         {&hf_ubx_rxm_rawx_reserved2,
2689             {"Reserved", "ubx.rxm.rawx.reserved2",
2690                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2691
2692         // RXM-SFRBX
2693         {&hf_ubx_rxm_sfrbx,
2694             {"UBX-RXM-SFRBX", "ubx.rxm.sfrbx",
2695                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
2696         {&hf_ubx_rxm_sfrbx_gnssid,
2697             {"GNSS ID", "ubx.rxm.sfrbx.gnssid",
2698                 FT_UINT8, BASE_DEC, VALS(UBX_GNSS_ID), 0x0, NULL, HFILL}},
2699         {&hf_ubx_rxm_sfrbx_svid,
2700             {"Satellite ID", "ubx.rxm.sfrbx.svid",
2701                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2702         {&hf_ubx_rxm_sfrbx_sigid,
2703             {"Signal identifier", "ubx.rxm.sfrbx.sigid",
2704                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2705         {&hf_ubx_rxm_sfrbx_freqid,
2706             {"Frequency identifier", "ubx.rxm.sfrbx.freqid",
2707                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2708         {&hf_ubx_rxm_sfrbx_numwords,
2709             {"Number of data words", "ubx.rxm.sfrbx.numwords",
2710                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2711         {&hf_ubx_rxm_sfrbx_chn,
2712             {"Tracking channel number", "ubx.rxm.sfrbx.chn",
2713                 FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL}},
2714         {&hf_ubx_rxm_sfrbx_version,
2715             {"Message version", "ubx.rxm.sfrbx.version",
2716                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2717         {&hf_ubx_rxm_sfrbx_dwrd,
2718             {"Data words (little endian)", "ubx.rxm.sfrbx.dwrd",
2719                 FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL}},
2720         {&hf_ubx_rxm_sfrbx_reserved1,
2721             {"Reserved 1", "ubx.rxm.sfrbx.reserved1",
2722                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2723         {&hf_ubx_rxm_sfrbx_reserved2,
2724             {"Reserved 2", "ubx.rxm.sfrbx.reserved2",
2725                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2726         {&hf_ubx_rxm_sfrbx_reserved3,
2727             {"Reserved 3", "ubx.rxm.sfrbx.reserved3",
2728                 FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL}},
2729     };
2730
2731     expert_module_t *expert_ubx;
2732
2733     static ei_register_info ei[] = {
2734         {&ei_ubx_chksum, {"ubx.chksum", PI_CHECKSUM, PI_WARN, "Chksum", EXPFILL}},
2735     };
2736
2737     static int *ett_part[] = {
2738         &ett_ubx,
2739         &ett_ubx_ack_ack,
2740         &ett_ubx_ack_nak,
2741         &ett_ubx_cfg_gnss,
2742         &ett_ubx_cfg_sbas,
2743         &ett_ubx_cfg_sbas_mode,
2744         &ett_ubx_cfg_sbas_scanmode,
2745         &ett_ubx_nav_dop,
2746         &ett_ubx_nav_eoe,
2747         &ett_ubx_nav_odo,
2748         &ett_ubx_nav_posecef,
2749         &ett_ubx_nav_pvt,
2750         &ett_ubx_nav_pvt_datetime,
2751         &ett_ubx_nav_pvt_valid,
2752         &ett_ubx_nav_pvt_flags,
2753         &ett_ubx_nav_pvt_flags2,
2754         &ett_ubx_nav_sat,
2755         &ett_ubx_nav_sat_flags,
2756         &ett_ubx_nav_sbas,
2757         &ett_ubx_nav_sbas_service,
2758         &ett_ubx_nav_timegps,
2759         &ett_ubx_nav_timegps_tow,
2760         &ett_ubx_nav_timegps_valid,
2761         &ett_ubx_nav_timeutc,
2762         &ett_ubx_nav_timeutc_valid,
2763         &ett_ubx_nav_velecef,
2764         &ett_ubx_rxm_measx,
2765         &ett_ubx_rxm_rawx,
2766         &ett_ubx_rxm_rawx_recstat,
2767         &ett_ubx_rxm_rawx_trkstat,
2768         &ett_ubx_rxm_sfrbx,
2769     };
2770
2771     static int *ett[array_length(ett_part)
2772         + array_length(ett_ubx_nav_sat_sv_info)
2773         + array_length(ett_ubx_cfg_gnss_block)
2774         + array_length(ett_ubx_nav_sbas_sv_info)
2775         + array_length(ett_ubx_rxm_rawx_meas)
2776         + array_length(ett_ubx_rxm_measx_meas)];
2777
2778     // fill ett with elements from ett_part,
2779     // pointers to ett_ubx_nav_sat_sv_info elements,
2780     // pointers to ett_ubx_cfg_gnss_block elements,
2781     // pointers to ett_ubx_nav_sbas_sv_info elements,
2782     // pointers to ett_ubx_rxm_rawx_meas elements, and
2783     // pointers to ett_ubx_rxm_measx_meas elements
2784     uint16_t i;
2785     for (i = 0; i < array_length(ett_part); i++) {
2786         ett[i] = ett_part[i];
2787     }
2788     for (i = 0; i < array_length(ett_ubx_nav_sat_sv_info); i++) {
2789         ett[i + array_length(ett_part)] = &ett_ubx_nav_sat_sv_info[i];
2790     }
2791     for (i = 0; i < array_length(ett_ubx_cfg_gnss_block); i++) {
2792         ett[i + array_length(ett_part) + array_length(ett_ubx_nav_sat_sv_info)]
2793             = &ett_ubx_cfg_gnss_block[i];
2794     }
2795     for (i = 0; i < array_length(ett_ubx_nav_sbas_sv_info); i++) {
2796         ett[i + array_length(ett_part) + array_length(ett_ubx_nav_sat_sv_info)
2797             + array_length(ett_ubx_cfg_gnss_block)]
2798             = &ett_ubx_nav_sbas_sv_info[i];
2799     }
2800     for (i = 0; i < array_length(ett_ubx_rxm_rawx_meas); i++) {
2801         ett[i + array_length(ett_part) + array_length(ett_ubx_nav_sat_sv_info)
2802             + array_length(ett_ubx_cfg_gnss_block)
2803             + array_length(ett_ubx_nav_sbas_sv_info)]
2804             = &ett_ubx_rxm_rawx_meas[i];
2805     }
2806     for (i = 0; i < array_length(ett_ubx_rxm_measx_meas); i++) {
2807         ett[i + array_length(ett_part) + array_length(ett_ubx_nav_sat_sv_info)
2808             + array_length(ett_ubx_cfg_gnss_block)
2809             + array_length(ett_ubx_nav_sbas_sv_info)
2810             + array_length(ett_ubx_rxm_rawx_meas)]
2811             = &ett_ubx_rxm_measx_meas[i];
2812     }
2813
2814     proto_ubx = proto_register_protocol("UBX Protocol", "UBX", "ubx");
2815
2816     ubx_handle = register_dissector("ubx", dissect_ubx, proto_ubx);
2817
2818     proto_register_field_array(proto_ubx, hf, array_length(hf));
2819     proto_register_subtree_array(ett, array_length(ett));
2820
2821     expert_ubx = expert_register_protocol(proto_ubx);
2822     expert_register_field_array(expert_ubx, ei, array_length(ei));
2823
2824     ubx_class_id_dissector_table = register_dissector_table("ubx.msg_class_id",
2825             "UBX Message Class & ID", proto_ubx, FT_UINT16, BASE_HEX);
2826     ubx_gnssid_dissector_table = register_dissector_table("ubx.rxm.sfrbx.gnssid",
2827             "UBX-RXM-SFRBX GNSS Type ID", proto_ubx,
2828             FT_UINT8, BASE_DEC);
2829 }
2830
2831 void proto_reg_handoff_ubx(void) {
2832     UBX_REGISTER_DISSECTOR(dissect_ubx_ack_ack,     UBX_ACK_ACK);
2833     UBX_REGISTER_DISSECTOR(dissect_ubx_ack_nak,     UBX_ACK_NAK);
2834     UBX_REGISTER_DISSECTOR(dissect_ubx_cfg_gnss,    UBX_CFG_GNSS);
2835     UBX_REGISTER_DISSECTOR(dissect_ubx_cfg_sbas,    UBX_CFG_SBAS);
2836     UBX_REGISTER_DISSECTOR(dissect_ubx_nav_dop,     UBX_NAV_DOP);
2837     UBX_REGISTER_DISSECTOR(dissect_ubx_nav_eoe,     UBX_NAV_EOE);
2838     UBX_REGISTER_DISSECTOR(dissect_ubx_nav_odo,     UBX_NAV_ODO);
2839     UBX_REGISTER_DISSECTOR(dissect_ubx_nav_posecef, UBX_NAV_POSECEF);
2840     UBX_REGISTER_DISSECTOR(dissect_ubx_nav_pvt,     UBX_NAV_PVT);
2841     UBX_REGISTER_DISSECTOR(dissect_ubx_nav_sat,     UBX_NAV_SAT);
2842     UBX_REGISTER_DISSECTOR(dissect_ubx_nav_sbas,    UBX_NAV_SBAS);
2843     UBX_REGISTER_DISSECTOR(dissect_ubx_nav_timegps, UBX_NAV_TIMEGPS);
2844     UBX_REGISTER_DISSECTOR(dissect_ubx_nav_timeutc, UBX_NAV_TIMEUTC);
2845     UBX_REGISTER_DISSECTOR(dissect_ubx_nav_velecef, UBX_NAV_VELECEF);
2846     UBX_REGISTER_DISSECTOR(dissect_ubx_rxm_measx,   UBX_RXM_MEASX);
2847     UBX_REGISTER_DISSECTOR(dissect_ubx_rxm_rawx,    UBX_RXM_RAWX);
2848     UBX_REGISTER_DISSECTOR(dissect_ubx_rxm_sfrbx,   UBX_RXM_SFRBX);
2849 }