/src/wireshark/wiretap/commview.c

Source
/* commview.c
 * Routines for opening CommView NCF and NCFX file format packet captures
 * Copyright 2007, Stephen Fisher (see AUTHORS file)
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 Gerald Combs
 *
 * Based on csids.c and nettl.c
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 */

/* A brief description of these file formats is available at:
 *    https://www.tamos.com/htmlhelp/commview/logformat.htm
 *    https://www.tamos.com/htmlhelp/commwifi/logformat.htm
 *
 * Use
 *
 *    https://web.archive.org/web/20171022225753/http://www.tamos.com/htmlhelp/commview/logformat.htm
 *
 * if that doesn't display anything.
 */

#include "config.h"
#include "commview.h"

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

#include "wtap_module.h"
#include "file_wrappers.h"

#include <wsutil/802_11-utils.h>

/*
 * Capture medium types used in NCF and NCFX;
 * Token Ring isn't used in NCFX.
 */
#define MEDIUM_ETHERNET   0
#define MEDIUM_WIFI   1
#define MEDIUM_TOKEN_RING 2

typedef struct commview_ncf_header {
  uint16_t  data_len;
  uint16_t  source_data_len;
  uint8_t   version;
  uint16_t  year;
  uint8_t   month;
  uint8_t   day;
  uint8_t   hours;
  uint8_t   minutes;
  uint8_t   seconds;
  uint32_t  usecs;
  uint8_t   flags;    /* Bit-field positions defined below */
  uint8_t   signal_level_percent;
  uint8_t   rate;
  uint8_t   band;
  uint8_t   channel;
  uint8_t   direction;  /* Or for WiFi, high order byte of
           * packet rate. */
  int8_t    signal_level_dbm; /* WiFi-only */
  int8_t    noise_level_dbm;  /* WiFi-only */
} commview_ncf_header_t;

#define COMMVIEW_NCF_HEADER_SIZE 24

/* Bit-field positions for various fields in the flags variable of the header */
#define FLAGS_MEDIUM    0x0F
#define FLAGS_DECRYPTED   0x10
#define FLAGS_BROKEN    0x20
#define FLAGS_COMPRESSED  0x40
#define FLAGS_RESERVED    0x80

/* Values for the band variable of the header */
#define BAND_11A    0x01
#define BAND_11B    0x02
#define BAND_11G    0x04
#define BAND_11A_TURBO    0x08
#define BAND_SUPERG   0x10
#define BAND_PUBLIC_SAFETY  0x20  /* 4.99 GHz public safety */
#define BAND_11N_5GHZ   0x40
#define BAND_11N_2_4GHZ   0x80

static bool commview_ncf_read(wtap *wth, wtap_rec *rec,
                              int *err, char **err_info, int64_t *data_offset);
static bool commview_ncf_seek_read(wtap *wth, int64_t seek_off,
           wtap_rec *rec,
           int *err, char **err_info);
static bool commview_ncf_read_header(commview_ncf_header_t *cv_hdr, FILE_T fh,
             int *err, char **err_info);
static bool commview_ncf_dump(wtap_dumper *wdh, const wtap_rec *rec,
            int *err, char **err_info);

static int commview_ncf_file_type_subtype = -1;
static int commview_ncfx_file_type_subtype = -1;

void register_commview(void);

wtap_open_return_val
commview_ncf_open(wtap *wth, int *err, char **err_info)
{
  commview_ncf_header_t cv_hdr;

  if(!commview_ncf_read_header(&cv_hdr, wth->fh, err, err_info)) {
    if (*err != 0 && *err != WTAP_ERR_SHORT_READ)
      return WTAP_OPEN_ERROR;
    return WTAP_OPEN_NOT_MINE;
  }

  /* If any of these fields do not match what we expect, bail out. */
  if(cv_hdr.version != 0 ||
     cv_hdr.year < 1970 || cv_hdr.year >= 2038 ||
     cv_hdr.month < 1 || cv_hdr.month > 12 ||
     cv_hdr.day < 1 || cv_hdr.day > 31 ||
     cv_hdr.hours > 23 ||
     cv_hdr.minutes > 59 ||
     cv_hdr.seconds > 60 ||
     cv_hdr.signal_level_percent > 100 ||
     (cv_hdr.flags & FLAGS_RESERVED) != 0 ||
     ((cv_hdr.flags & FLAGS_MEDIUM) != MEDIUM_ETHERNET &&
      (cv_hdr.flags & FLAGS_MEDIUM) != MEDIUM_WIFI &&
      (cv_hdr.flags & FLAGS_MEDIUM) != MEDIUM_TOKEN_RING))
    return WTAP_OPEN_NOT_MINE; /* Not our kind of file */

  /* No file header. Reset the fh to 0 so we can read the first packet */
  if (file_seek(wth->fh, 0, SEEK_SET, err) == -1)
    return WTAP_OPEN_ERROR;

  /* Set up the pointers to the handlers for this file type */
  wth->subtype_read = commview_ncf_read;
  wth->subtype_seek_read = commview_ncf_seek_read;

  wth->file_type_subtype = commview_ncf_file_type_subtype;
  wth->file_encap = WTAP_ENCAP_PER_PACKET;
  wth->file_tsprec = WTAP_TSPREC_USEC;

  return WTAP_OPEN_MINE; /* Our kind of file */
}

static int
commview_ncf_read_packet(FILE_T fh, wtap_rec *rec,
    int *err, char **err_info)
{
  commview_ncf_header_t cv_hdr;
  struct tm tm;
  unsigned frequency;

  if(!commview_ncf_read_header(&cv_hdr, fh, err, err_info))
    return false;

  wtap_setup_packet_rec(rec, WTAP_ENCAP_UNKNOWN);
  rec->block = wtap_block_create(WTAP_BLOCK_PACKET);

  /*
   * The maximum value of cv_hdr.data_len is 65535, which is less
   * than WTAP_MAX_PACKET_SIZE_STANDARD will ever be, so we don't need to
   * check it.
   */

  switch(cv_hdr.flags & FLAGS_MEDIUM) {

  case MEDIUM_ETHERNET :
    rec->rec_header.packet_header.pkt_encap = WTAP_ENCAP_ETHERNET;
    rec->rec_header.packet_header.pseudo_header.eth.fcs_len = -1; /* Unknown */
    break;

  case MEDIUM_WIFI :
    rec->rec_header.packet_header.pkt_encap = WTAP_ENCAP_IEEE_802_11_WITH_RADIO;
    memset(&rec->rec_header.packet_header.pseudo_header.ieee_802_11, 0, sizeof(rec->rec_header.packet_header.pseudo_header.ieee_802_11));
    rec->rec_header.packet_header.pseudo_header.ieee_802_11.fcs_len = -1; /* Unknown */
    rec->rec_header.packet_header.pseudo_header.ieee_802_11.decrypted = false;
    rec->rec_header.packet_header.pseudo_header.ieee_802_11.datapad = false;
    rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy = PHDR_802_11_PHY_UNKNOWN;
    switch (cv_hdr.band) {

    case BAND_11A:
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy = PHDR_802_11_PHY_11A;
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11a.has_channel_type = false;
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11a.has_turbo_type = true;
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11a.turbo_type =
          PHDR_802_11A_TURBO_TYPE_NORMAL;
      frequency = ieee80211_chan_to_mhz(cv_hdr.channel, false);
      break;

    case BAND_11B:
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy = PHDR_802_11_PHY_11B;
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11b.has_short_preamble = false;
      frequency = ieee80211_chan_to_mhz(cv_hdr.channel, true);
      break;

    case BAND_11G:
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy = PHDR_802_11_PHY_11G;
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11g.has_mode = true;
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11g.mode =
          PHDR_802_11G_MODE_NORMAL;
      frequency = ieee80211_chan_to_mhz(cv_hdr.channel, true);
      break;

    case BAND_11A_TURBO:
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy = PHDR_802_11_PHY_11A;
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11a.has_turbo_type = true;
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11a.turbo_type =
          PHDR_802_11A_TURBO_TYPE_TURBO;
      frequency = ieee80211_chan_to_mhz(cv_hdr.channel, false);
      break;

    case BAND_SUPERG:
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy = PHDR_802_11_PHY_11G;
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11g.has_mode = true;
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11g.mode =
          PHDR_802_11G_MODE_SUPER_G;
      frequency = ieee80211_chan_to_mhz(cv_hdr.channel, true);
      break;

    case BAND_11N_5GHZ:
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy = PHDR_802_11_PHY_11N;
      frequency = ieee80211_chan_to_mhz(cv_hdr.channel, false);
      break;

    case BAND_11N_2_4GHZ:
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy = PHDR_802_11_PHY_11N;
      frequency = ieee80211_chan_to_mhz(cv_hdr.channel, true);
      break;

    case BAND_PUBLIC_SAFETY:
      /*
       * XXX - what do we do here?  What are the channel
       * numbers?  How do we distinguish the several
       * different flavors of 4.9 GHz frequencies?
       */
      frequency = 0;
      break;

    default:
      frequency = 0;
      break;
    }
    if (frequency != 0) {
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.has_frequency = true;
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.frequency = frequency;
    }
    rec->rec_header.packet_header.pseudo_header.ieee_802_11.has_channel = true;
    rec->rec_header.packet_header.pseudo_header.ieee_802_11.channel = cv_hdr.channel;

    rec->rec_header.packet_header.pseudo_header.ieee_802_11.has_data_rate = true;
    rec->rec_header.packet_header.pseudo_header.ieee_802_11.data_rate =
        cv_hdr.rate | (cv_hdr.direction << 8);

    rec->rec_header.packet_header.pseudo_header.ieee_802_11.has_signal_percent = true;
    rec->rec_header.packet_header.pseudo_header.ieee_802_11.signal_percent = cv_hdr.signal_level_percent;

    /*
     * XXX - these are positive in captures I've seen; does
     * that mean that they are the negative of the actual
     * dBm value?  (80 dBm is a bit more power than most
     * countries' regulatory agencies are likely to allow
     * any individual to have in their home. :-))
     *
     * XXX - sometimes these are 0; assume that means that no
     * value is provided.
     */
    if (cv_hdr.signal_level_dbm != 0) {
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.signal_dbm = -cv_hdr.signal_level_dbm;
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.has_signal_dbm = true;
    }
    if (cv_hdr.noise_level_dbm != 0) {
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.noise_dbm = -cv_hdr.noise_level_dbm;
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.has_noise_dbm = true;
    }
    if (rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy == PHDR_802_11_PHY_UNKNOWN) {
      /*
       * We don't know they PHY, but we do have the
       * data rate; try to guess it based on the
       * data rate and center frequency.
       */
      if (RATE_IS_DSSS(rec->rec_header.packet_header.pseudo_header.ieee_802_11.data_rate)) {
        /* 11b */
        rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy = PHDR_802_11_PHY_11B;
        rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11b.has_short_preamble = false;
      } else if (RATE_IS_OFDM(rec->rec_header.packet_header.pseudo_header.ieee_802_11.data_rate)) {
        /* 11a or 11g, depending on the band. */
        if (rec->rec_header.packet_header.pseudo_header.ieee_802_11.has_frequency) {
          if (FREQ_IS_BG(rec->rec_header.packet_header.pseudo_header.ieee_802_11.frequency)) {
            /* 11g */
            rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy = PHDR_802_11_PHY_11G;
          } else {
            /* 11a */
            rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy = PHDR_802_11_PHY_11A;
          }
        }
      }
    } else if (rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy == PHDR_802_11_PHY_11G) {
      if (RATE_IS_DSSS(rec->rec_header.packet_header.pseudo_header.ieee_802_11.data_rate)) {
        /* DSSS, so 11b. */
        rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy = PHDR_802_11_PHY_11B;
        rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11b.has_short_preamble = false;
      }
    }
    break;

  case MEDIUM_TOKEN_RING :
    rec->rec_header.packet_header.pkt_encap = WTAP_ENCAP_TOKEN_RING;
    break;

  default :
    *err = WTAP_ERR_BAD_FILE;
    *err_info = ws_strdup_printf("commview: unsupported encap for NCF: %u",
              cv_hdr.flags & FLAGS_MEDIUM);
    return false;
  }

  tm.tm_year = cv_hdr.year - 1900;
  tm.tm_mon = cv_hdr.month - 1;
  tm.tm_mday = cv_hdr.day;
  tm.tm_hour = cv_hdr.hours;
  tm.tm_min = cv_hdr.minutes;
  tm.tm_sec = cv_hdr.seconds;
  tm.tm_isdst = -1;

  rec->presence_flags = WTAP_HAS_TS;

  rec->rec_header.packet_header.len = cv_hdr.data_len;
  rec->rec_header.packet_header.caplen = cv_hdr.data_len;

  rec->ts.secs = mktime(&tm);
  rec->ts.nsecs = cv_hdr.usecs * 1000;

  return wtap_read_bytes_buffer(fh, &rec->data, rec->rec_header.packet_header.caplen, err, err_info);
}

static bool
commview_ncf_read(wtap *wth, wtap_rec *rec, int *err,
    char **err_info, int64_t *data_offset)
{
  *data_offset = file_tell(wth->fh);

  return commview_ncf_read_packet(wth->fh, rec, err, err_info);
}

static bool
commview_ncf_seek_read(wtap *wth, int64_t seek_off, wtap_rec *rec,
    int *err, char **err_info)
{
  if(file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
    return false;

  return commview_ncf_read_packet(wth->random_fh, rec, err, err_info);
}

static bool
commview_ncf_read_header(commview_ncf_header_t *cv_hdr, FILE_T fh, int *err,
    char **err_info)
{
  if (!wtap_read_bytes_or_eof(fh, &cv_hdr->data_len, 2, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_hdr->source_data_len, 2, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_hdr->version, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_hdr->year, 2, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_hdr->month, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_hdr->day, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_hdr->hours, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_hdr->minutes, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_hdr->seconds, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_hdr->usecs, 4, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_hdr->flags, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_hdr->signal_level_percent, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_hdr->rate, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_hdr->band, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_hdr->channel, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_hdr->direction, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_hdr->signal_level_dbm, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_hdr->noise_level_dbm, 1, err, err_info))
    return false;

  /* Convert multi-byte values from little endian to host endian format */
  cv_hdr->data_len = GUINT16_FROM_LE(cv_hdr->data_len);
  cv_hdr->source_data_len = GUINT16_FROM_LE(cv_hdr->source_data_len);
  cv_hdr->year = GUINT16_FROM_LE(cv_hdr->year);
  cv_hdr->usecs = GUINT32_FROM_LE(cv_hdr->usecs);

  return true;
}

/* Returns 0 if we can write out the specified encapsulation type
 * into a CommView format file. */
static int
commview_ncf_dump_can_write_encap(int encap)
{
  switch (encap) {

  case WTAP_ENCAP_ETHERNET :
  case WTAP_ENCAP_IEEE_802_11 :
  case WTAP_ENCAP_IEEE_802_11_WITH_RADIO :
  case WTAP_ENCAP_TOKEN_RING :
  case WTAP_ENCAP_PER_PACKET :
    return 0;

  default:
    return WTAP_ERR_UNWRITABLE_ENCAP;
  }
}

/* Returns true on success, false on failure;
   sets "*err" to an error code on failure */
static bool
commview_ncf_dump_open(wtap_dumper *wdh, int *err _U_, char **err_info _U_)
{
  wdh->subtype_write = commview_ncf_dump;

  /* There is no file header to write out */
  return true;
}

/* Write a record for a packet to a dump file.
 * Returns true on success, false on failure. */
static bool
commview_ncf_dump(wtap_dumper *wdh, const wtap_rec *rec,
    int *err, char **err_info _U_)
{
  commview_ncf_header_t cv_hdr = {0};
  struct tm *tm;

  /* We can only write packet records. */
  if (rec->rec_type != REC_TYPE_PACKET) {
    *err = WTAP_ERR_UNWRITABLE_REC_TYPE;
    *err_info = wtap_unwritable_rec_type_err_string(rec);
    return false;
  }

  /* Don't write out anything bigger than we can read.
   * (The length field in packet headers is 16 bits, which
   * imposes a hard limit.) */
  if (rec->rec_header.packet_header.caplen > 65535) {
    *err = WTAP_ERR_PACKET_TOO_LARGE;
    return false;
  }

  cv_hdr.data_len = GUINT16_TO_LE((uint16_t)rec->rec_header.packet_header.caplen);
  cv_hdr.source_data_len = GUINT16_TO_LE((uint16_t)rec->rec_header.packet_header.caplen);
  cv_hdr.version = 0;

  tm = localtime(&rec->ts.secs);
  if (tm != NULL) {
    cv_hdr.year = GUINT16_TO_LE(tm->tm_year + 1900);
    cv_hdr.month = tm->tm_mon + 1;
    cv_hdr.day = tm->tm_mday;
    cv_hdr.hours = tm->tm_hour;
    cv_hdr.minutes = tm->tm_min;
    cv_hdr.seconds = tm->tm_sec;
    cv_hdr.usecs = GUINT32_TO_LE(rec->ts.nsecs / 1000);
  } else {
    /*
     * Second before the Epoch.
     */
    cv_hdr.year = GUINT16_TO_LE(1969);
    cv_hdr.month = 12;
    cv_hdr.day = 31;
    cv_hdr.hours = 23;
    cv_hdr.minutes = 59;
    cv_hdr.seconds = 59;
    cv_hdr.usecs = 0;
  }

  switch(rec->rec_header.packet_header.pkt_encap) {

  case WTAP_ENCAP_ETHERNET :
    cv_hdr.flags |= MEDIUM_ETHERNET;
    break;

  case WTAP_ENCAP_IEEE_802_11 :
    cv_hdr.flags |=  MEDIUM_WIFI;
    break;

  case WTAP_ENCAP_IEEE_802_11_WITH_RADIO :
    cv_hdr.flags |=  MEDIUM_WIFI;

    switch (rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy) {

    case PHDR_802_11_PHY_11A:
      /*
       * If we don't know whether it's turbo, say it's
       * not.
       */
      if (!rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11a.has_turbo_type ||
          rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11a.turbo_type == PHDR_802_11A_TURBO_TYPE_NORMAL)
        cv_hdr.band = BAND_11A;
      else
        cv_hdr.band = BAND_11A_TURBO;
      break;

    case PHDR_802_11_PHY_11B:
      cv_hdr.band = BAND_11B;
      break;

    case PHDR_802_11_PHY_11G:
      /*
       * If we don't know whether it's Super G, say it's
       * not.
       */
      if (!rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11g.has_mode)
        cv_hdr.band = BAND_11G;
      else {
        switch (rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11g.mode) {

        case PHDR_802_11G_MODE_NORMAL:
          cv_hdr.band = BAND_11G;
          break;

        case PHDR_802_11G_MODE_SUPER_G:
          cv_hdr.band = BAND_SUPERG;
          break;

        default:
          cv_hdr.band = BAND_11G;
          break;
        }
      }
      break;

    case PHDR_802_11_PHY_11N:
      /*
       * Pick the band based on the frequency.
       */
      if (rec->rec_header.packet_header.pseudo_header.ieee_802_11.has_frequency) {
        if (rec->rec_header.packet_header.pseudo_header.ieee_802_11.frequency > 2484) {
          /* 5 GHz band */
          cv_hdr.band = BAND_11N_5GHZ;
        } else {
          /* 2.4 GHz band */
          cv_hdr.band = BAND_11N_2_4GHZ;
        }
      } else {
        /* Band is unknown. */
        cv_hdr.band = 0;
      }
      break;

    default:
      /*
       * It's not documented how they handle 11ac,
       * and they don't support the older PHYs.
       */
      cv_hdr.band = 0;
      break;
    }
    cv_hdr.channel =
        rec->rec_header.packet_header.pseudo_header.ieee_802_11.has_channel ?
          rec->rec_header.packet_header.pseudo_header.ieee_802_11.channel :
          0;
    cv_hdr.rate =
        rec->rec_header.packet_header.pseudo_header.ieee_802_11.has_data_rate ?
          (uint8_t)(rec->rec_header.packet_header.pseudo_header.ieee_802_11.data_rate & 0xFF) :
          0;
    cv_hdr.direction =
        rec->rec_header.packet_header.pseudo_header.ieee_802_11.has_data_rate ?
          (uint8_t)((rec->rec_header.packet_header.pseudo_header.ieee_802_11.data_rate >> 8) & 0xFF) :
          0;
    cv_hdr.signal_level_percent =
        rec->rec_header.packet_header.pseudo_header.ieee_802_11.has_signal_percent ?
          rec->rec_header.packet_header.pseudo_header.ieee_802_11.signal_percent :
          0;
    cv_hdr.signal_level_dbm =
        rec->rec_header.packet_header.pseudo_header.ieee_802_11.has_signal_dbm ?
          -rec->rec_header.packet_header.pseudo_header.ieee_802_11.signal_dbm :
          0;
    cv_hdr.noise_level_dbm =
        rec->rec_header.packet_header.pseudo_header.ieee_802_11.has_noise_dbm ?
          -rec->rec_header.packet_header.pseudo_header.ieee_802_11.noise_dbm :
          0;
    break;

  case WTAP_ENCAP_TOKEN_RING :
    cv_hdr.flags |= MEDIUM_TOKEN_RING;
    break;

  default :
    *err = WTAP_ERR_UNWRITABLE_ENCAP;
    return false;
  }

  if (!wtap_dump_file_write(wdh, &cv_hdr.data_len, 2, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.source_data_len, 2, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.version, 1, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.year, 2, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.month, 1, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.day, 1, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.hours, 1, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.minutes, 1, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.seconds, 1, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.usecs, 4, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.flags, 1, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.signal_level_percent, 1, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.rate, 1, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.band, 1, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.channel, 1, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.direction, 1, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.signal_level_dbm, 1, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.noise_level_dbm, 1, err))
    return false;
  if (!wtap_dump_file_write(wdh, ws_buffer_start_ptr(&rec->data), rec->rec_header.packet_header.caplen, err))
    return false;
  return true;
}

typedef struct commview_ncfx_header {
  uint32_t  data_len;
  uint16_t  year;
  uint8_t   month;
  uint8_t   day;
  uint8_t   hours;
  uint8_t   minutes;
  uint8_t   seconds;
  uint32_t  usecs;
  uint8_t   medium_type;
  uint8_t   decryption_flag;
  uint8_t   direction;
  uint8_t   reserved1;
  uint8_t   reserved2;
} commview_ncfx_header_t;

#define COMMVIEW_NCFX_HEADER_SIZE 20

typedef struct commview_ncfx_rf_header {
  uint16_t  header_len;   /* includes extension headers */
  uint16_t  status_modulation;
  uint16_t  frequency_band;
  uint16_t  channel;
  uint8_t   noise_level_dbm;  /* abs(noise in dBm) */
  uint8_t   signal_level_dbm; /* abs(signal in dBm) */
  uint8_t   signal_level_percent;
  uint8_t   reserved;
  uint32_t  phy_rate;   /* in 100Kbps units */
  uint32_t  extensions_present;
} commview_ncfx_rf_header_t;

#define COMMVIEW_NCFX_RF_HEADER_SIZE  20

typedef struct commview_ncfx_mcs_header {
  uint8_t   mcs_index;
  uint8_t   n_streams;
  uint8_t   channel_width;
  uint8_t   guard_interval;
} commview_ncfx_mcs_header_t;

#define COMMVIEW_NCFX_MCS_HEADER_SIZE 4

/*
 * Bit-field positions for various fields in the status_modulation variable
 * of the header.
 */
#define STATUS_MODULATION_BAD_FCS 0x01
#define STATUS_MODULATION_HT_PHY  0x02
#define STATUS_MODULATION_VHT_PHY 0x04
#define STATUS_MODULATION_HE_PHY  0x08
#define STATUS_MODULATION_HE_OFDMA  0x10

/* Values for the frequency_band variable of the header */
#define BAND_5GHZ   0x40
#define BAND_2_4GHZ   0x80

/* Presence bits */
#define PRESENCE_MCS_HEADER 0x00000001  /* type 0, bit 0 */

static bool commview_ncfx_read(wtap *wth, wtap_rec *rec,
    int *err, char **err_info, int64_t *data_offset);
static bool commview_ncfx_seek_read(wtap *wth, int64_t seek_off,
    wtap_rec *rec, int *err, char **err_info);
static bool commview_ncfx_read_header(commview_ncfx_header_t *cv_hdr,
    FILE_T fh, int *err, char **err_info);
static bool commview_ncfx_read_rf_header(commview_ncfx_rf_header_t *cv_rf_hdr,
    FILE_T fh, int *err, char **err_info);
static bool commview_ncfx_read_mcs_header(commview_ncfx_mcs_header_t *cv_mcs_hdr,
    FILE_T fh, int *err, char **err_info);
static bool commview_ncfx_dump(wtap_dumper *wdh, const wtap_rec *rec,
    int *err, char **err_info);

wtap_open_return_val
commview_ncfx_open(wtap *wth, int *err, char **err_info)
{
  commview_ncfx_header_t cv_hdr;

  if(!commview_ncfx_read_header(&cv_hdr, wth->fh, err, err_info)) {
    if (*err == 0) {
      /* EOF - not our file */
      return WTAP_OPEN_NOT_MINE;
    }
    if (*err == WTAP_ERR_SHORT_READ) {
      /* Short read - not our file */
      return WTAP_OPEN_NOT_MINE;
    }
    if (*err == WTAP_ERR_BAD_FILE) {
      /*
       * Not a valid record header - not our file;
       * discard the error.
       */
      wmem_free(NULL, *err_info);
      *err_info = NULL;
      return WTAP_OPEN_NOT_MINE;
    }
    /* Hard error. */
    return WTAP_OPEN_ERROR;
  }

  /* If any of these fields do not match what we expect, bail out. */
  if(cv_hdr.year < 2000 || /* XXX - when was this format introduced? */
     cv_hdr.month < 1 || cv_hdr.month > 12 ||
     cv_hdr.day < 1 || cv_hdr.day > 31 ||
     cv_hdr.hours > 23 ||
     cv_hdr.minutes > 59 ||
     cv_hdr.seconds > 60)
    return WTAP_OPEN_NOT_MINE; /* Not our kind of file */
  switch (cv_hdr.medium_type) {

  case MEDIUM_ETHERNET:
    if (cv_hdr.direction != 0x00 &&
        cv_hdr.direction != 0x01 &&
        cv_hdr.direction != 0x02)
      return WTAP_OPEN_NOT_MINE; /* Not our kind of file */
    break;

  case MEDIUM_WIFI:
    if (cv_hdr.decryption_flag != 0x00 &&
        cv_hdr.decryption_flag != 0x01)
      return WTAP_OPEN_NOT_MINE; /* Not our kind of file */
    if (cv_hdr.direction != 0x00)
      return WTAP_OPEN_NOT_MINE; /* Not our kind of file */
    break;

  default:
    return WTAP_OPEN_NOT_MINE; /* Not our kind of file */
  }

  /* No file header. Reset the fh to 0 so we can read the first packet */
  if (file_seek(wth->fh, 0, SEEK_SET, err) == -1)
    return WTAP_OPEN_ERROR;

  /* Set up the pointers to the handlers for this file type */
  wth->subtype_read = commview_ncfx_read;
  wth->subtype_seek_read = commview_ncfx_seek_read;

  wth->file_type_subtype = commview_ncfx_file_type_subtype;
  wth->file_encap = WTAP_ENCAP_PER_PACKET;
  wth->file_tsprec = WTAP_TSPREC_USEC;

  return WTAP_OPEN_MINE; /* Our kind of file */
}

static int
commview_ncfx_read_packet(FILE_T fh, wtap_rec *rec,
    int *err, char **err_info)
{
  commview_ncfx_header_t cv_hdr;
  uint32_t length_remaining;
  struct tm tm;
  commview_ncfx_rf_header_t cv_rf_hdr;
  unsigned frequency;
  commview_ncfx_mcs_header_t cv_mcs_hdr;

  if (!commview_ncfx_read_header(&cv_hdr, fh, err, err_info))
    return false;

  wtap_setup_packet_rec(rec, WTAP_ENCAP_UNKNOWN);
  rec->block = wtap_block_create(WTAP_BLOCK_PACKET);

  /* Amount of data remaining in the record, after the header */
  length_remaining = cv_hdr.data_len - COMMVIEW_NCFX_HEADER_SIZE;

  switch(cv_hdr.medium_type) {

  case MEDIUM_ETHERNET :
    rec->rec_header.packet_header.pkt_encap = WTAP_ENCAP_ETHERNET;
    rec->rec_header.packet_header.pseudo_header.eth.fcs_len = -1; /* Unknown */
    break;

  case MEDIUM_WIFI :
    rec->rec_header.packet_header.pkt_encap = WTAP_ENCAP_IEEE_802_11_WITH_RADIO;
    memset(&rec->rec_header.packet_header.pseudo_header.ieee_802_11, 0, sizeof(rec->rec_header.packet_header.pseudo_header.ieee_802_11));
    rec->rec_header.packet_header.pseudo_header.ieee_802_11.fcs_len = 0; /* No FCS */
    rec->rec_header.packet_header.pseudo_header.ieee_802_11.decrypted = (cv_hdr.decryption_flag == 0x01);
    rec->rec_header.packet_header.pseudo_header.ieee_802_11.datapad = false;

    /*
     * Make sure we have enough data left for the RF header.
     */
    if (length_remaining < COMMVIEW_NCFX_RF_HEADER_SIZE) {
      *err = WTAP_ERR_BAD_FILE;
      *err_info = ws_strdup_printf("commview: RF header goes past the NCFX data length %u",
          cv_hdr.data_len);
      return false;
    }
    length_remaining -= COMMVIEW_NCFX_RF_HEADER_SIZE;

    /*
     * Read the RF header.
     */
    if (!commview_ncfx_read_rf_header(&cv_rf_hdr, fh, err, err_info))
      return false;
    if (cv_rf_hdr.status_modulation & STATUS_MODULATION_HE_PHY)
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy = PHDR_802_11_PHY_11AX;
    else if (cv_rf_hdr.status_modulation & STATUS_MODULATION_VHT_PHY)
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy = PHDR_802_11_PHY_11AC;
    else if (cv_rf_hdr.status_modulation & STATUS_MODULATION_HT_PHY)
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy = PHDR_802_11_PHY_11N;
    else {
      /*
       * Unknown PHY, for now.
       */
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy = PHDR_802_11_PHY_UNKNOWN;
    }
    switch (cv_rf_hdr.frequency_band) {

    case BAND_5GHZ:
      frequency = ieee80211_chan_to_mhz(cv_rf_hdr.channel, false);
      if (rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy == PHDR_802_11_PHY_UNKNOWN) {
        /*
         * None of the modulation bits were set, so
         * this is presumably the 11a OFDM PHY.
         */
        rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy = PHDR_802_11_PHY_11A;
      }
      break;

    case BAND_2_4GHZ:
      frequency = ieee80211_chan_to_mhz(cv_rf_hdr.channel, true);
      if (rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy == PHDR_802_11_PHY_UNKNOWN) {
        /*
         * None of the modulation bits were set, so
         * guess the PHY based on the data rate.
         *
         * cv_rf_hdr.phy_rate is in units of 100
         * Kbits/s.
         */
        if (cv_rf_hdr.phy_rate == 10 /* 1 Mb/s */ ||
            cv_rf_hdr.phy_rate == 20 /* 2 Mb/s */ ||
            cv_rf_hdr.phy_rate == 55 /* 5.5 Mb/s */ ||
            cv_rf_hdr.phy_rate == 110 /* 11 Mb/s */ ||
            cv_rf_hdr.phy_rate == 220 /* 22 Mb/s */ ||
            cv_rf_hdr.phy_rate == 330 /* 33 Mb/s */)
          rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy = PHDR_802_11_PHY_11B;
        else
          rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy = PHDR_802_11_PHY_11G;
      }
      break;

    default:
      frequency = 0;
      break;
    }
    if (frequency != 0) {
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.has_frequency = true;
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.frequency = frequency;
    }
    rec->rec_header.packet_header.pseudo_header.ieee_802_11.has_channel = true;
    rec->rec_header.packet_header.pseudo_header.ieee_802_11.channel = cv_rf_hdr.channel;

    /*
     * cv_rf_hdr.phy_rate is in units of 100 Kbits/s.
     *
     * pseudo_header.ieee_802_11.data_rate is in units of 500
     * Kbits/s.
     */
    rec->rec_header.packet_header.pseudo_header.ieee_802_11.has_data_rate = true;
    rec->rec_header.packet_header.pseudo_header.ieee_802_11.data_rate =
        cv_rf_hdr.phy_rate/5;

    rec->rec_header.packet_header.pseudo_header.ieee_802_11.has_signal_percent = true;
    rec->rec_header.packet_header.pseudo_header.ieee_802_11.signal_percent = cv_rf_hdr.signal_level_percent;

    /*
     * These is the absolute value of the signal and noise,
     * in dBm.  The value is the negative of that.
     *
     * XXX - sometimes these are 0; assume that means that no
     * value is provided.
     */
    if (cv_rf_hdr.signal_level_dbm != 0) {
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.signal_dbm = -cv_rf_hdr.signal_level_dbm;
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.has_signal_dbm = true;
    }
    if (cv_rf_hdr.noise_level_dbm != 0) {
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.noise_dbm = -cv_rf_hdr.noise_level_dbm;
      rec->rec_header.packet_header.pseudo_header.ieee_802_11.has_noise_dbm = true;
    }

    if (cv_rf_hdr.extensions_present & PRESENCE_MCS_HEADER) {
      /*
       * Make sure we have enough data left for the
       * MCS header.
       */
      if (length_remaining < COMMVIEW_NCFX_MCS_HEADER_SIZE) {
        *err = WTAP_ERR_BAD_FILE;
        *err_info = ws_strdup_printf("commview: MCS header goes past the NCFX data length %u",
            cv_hdr.data_len);
        return false;
      }
      length_remaining -= COMMVIEW_NCFX_MCS_HEADER_SIZE;

      /*
       * Read the MCS header.
       */
      if (!commview_ncfx_read_mcs_header(&cv_mcs_hdr, fh,
          err, err_info))
        return false;
      switch (rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy) {

      case PHDR_802_11_PHY_11N:
        rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11n.has_mcs_index = true;
        rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11n.mcs_index = cv_mcs_hdr.mcs_index;
        /* number of STBC streams? */
        switch (cv_mcs_hdr.channel_width) {

        case 0x00:
          rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11n.has_bandwidth = true;
          rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11n.bandwidth = PHDR_802_11_BANDWIDTH_20_MHZ;
          break;

        case 0x01:
          rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11n.has_bandwidth = true;
          rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11n.bandwidth = PHDR_802_11_BANDWIDTH_40_MHZ;
          break;

        default:
          break;
        }
        /* Guard interval? */
        break;

      case PHDR_802_11_PHY_11AC:
        rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11ac.mcs[0] = cv_mcs_hdr.mcs_index;
        rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11ac.mcs[1] = 0;
        rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11ac.mcs[2] = 0;
        rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11ac.mcs[3] = 0;
        /* Remaining MCS indices? */
        rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11ac.nss[0] = cv_mcs_hdr.n_streams;
        switch (cv_mcs_hdr.channel_width) {

        case 0x00:
          rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11ac.has_bandwidth = true;
          rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11ac.bandwidth = PHDR_802_11_BANDWIDTH_20_MHZ;
          break;

        case 0x01:
          rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11ac.has_bandwidth = true;
          rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11ac.bandwidth = PHDR_802_11_BANDWIDTH_40_MHZ;
          break;

        case 0x02:
          rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11ac.has_bandwidth = true;
          rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11ac.bandwidth = PHDR_802_11_BANDWIDTH_80_MHZ;
          break;

        default:
          break;
        }
        /* Guard interval? */
        break;

      case PHDR_802_11_PHY_11AX:
        rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11ax.has_mcs_index = true;
        rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11ax.mcs = cv_mcs_hdr.mcs_index;
        rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy_info.info_11ax.nsts = cv_mcs_hdr.n_streams;
        /* Bandwidth stuff? */
        /* Guard interval? */
        break;

      default:
        break;
      }
    }
    break;

  default :
    *err = WTAP_ERR_BAD_FILE;
    *err_info = ws_strdup_printf("commview: unsupported encap for NCFX: %u",
              cv_hdr.medium_type);
    return false;
  }

  tm.tm_year = cv_hdr.year - 1900;
  tm.tm_mon = cv_hdr.month - 1;
  tm.tm_mday = cv_hdr.day;
  tm.tm_hour = cv_hdr.hours;
  tm.tm_min = cv_hdr.minutes;
  tm.tm_sec = cv_hdr.seconds;
  tm.tm_isdst = -1;

  rec->presence_flags = WTAP_HAS_TS;

  if (length_remaining > WTAP_MAX_PACKET_SIZE_STANDARD) {
    /*
     * Probably a corrupt capture file; don't blow up trying
     * to allocate space for an immensely-large packet.
     */
    *err = WTAP_ERR_BAD_FILE;
    *err_info = ws_strdup_printf("commview: File has %u-byte packet, bigger than maximum of %u",
        length_remaining, WTAP_MAX_PACKET_SIZE_STANDARD);
    return false;
  }

  rec->rec_header.packet_header.len = length_remaining;
  rec->rec_header.packet_header.caplen = length_remaining;

  rec->ts.secs = mktime(&tm);
  rec->ts.nsecs = cv_hdr.usecs * 1000;

  return wtap_read_bytes_buffer(fh, &rec->data, rec->rec_header.packet_header.caplen, err, err_info);
}

static bool
commview_ncfx_read(wtap *wth, wtap_rec *rec, int *err, char **err_info,
    int64_t *data_offset)
{
  *data_offset = file_tell(wth->fh);

  return commview_ncfx_read_packet(wth->fh, rec, err, err_info);
}

static bool
commview_ncfx_seek_read(wtap *wth, int64_t seek_off, wtap_rec *rec,
    int *err, char **err_info)
{
  if(file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
    return false;

  return commview_ncfx_read_packet(wth->random_fh, rec, err, err_info);
}

static bool
commview_ncfx_read_header(commview_ncfx_header_t *cv_hdr, FILE_T fh, int *err,
    char **err_info)
{
  if (!wtap_read_bytes_or_eof(fh, &cv_hdr->data_len, 4, err, err_info))
    return false;

  /* Convert data length from little endian to host endian format */
  cv_hdr->data_len = GUINT32_FROM_LE(cv_hdr->data_len);

  /* It must be at least the length of the general header. */
  if (cv_hdr->data_len < COMMVIEW_NCFX_HEADER_SIZE) {
    *err = WTAP_ERR_BAD_FILE;
    *err_info = ws_strdup_printf("commview: NCFX data length %u < %u",
              cv_hdr->data_len,
              COMMVIEW_NCFX_HEADER_SIZE);
    return false;
  }

  if (!wtap_read_bytes(fh, &cv_hdr->year, 2, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_hdr->month, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_hdr->day, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_hdr->hours, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_hdr->minutes, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_hdr->seconds, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_hdr->usecs, 4, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_hdr->medium_type, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_hdr->decryption_flag, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_hdr->direction, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_hdr->reserved1, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_hdr->reserved2, 1, err, err_info))
    return false;

  /* Convert multi-byte values from little endian to host endian format */
  cv_hdr->year = GUINT16_FROM_LE(cv_hdr->year);
  cv_hdr->usecs = GUINT32_FROM_LE(cv_hdr->usecs);

  return true;
}

static bool
commview_ncfx_read_rf_header(commview_ncfx_rf_header_t *cv_rf_hdr, FILE_T fh,
    int *err, char **err_info)
{
  if (!wtap_read_bytes(fh, &cv_rf_hdr->header_len, 2, err, err_info))
    return false;

  /* Convert header length from little endian to host endian format */
  cv_rf_hdr->header_len = GUINT16_FROM_LE(cv_rf_hdr->header_len);

  if (!wtap_read_bytes(fh, &cv_rf_hdr->status_modulation, 2, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_rf_hdr->frequency_band, 2, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_rf_hdr->channel, 2, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_rf_hdr->noise_level_dbm, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_rf_hdr->signal_level_dbm, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_rf_hdr->signal_level_percent, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_rf_hdr->reserved, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_rf_hdr->phy_rate, 4, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_rf_hdr->extensions_present, 4, err, err_info))
    return false;

  /* Convert remaining multi-byte values from little endian to host endian format */
  cv_rf_hdr->status_modulation = GUINT16_FROM_LE(cv_rf_hdr->status_modulation);
  cv_rf_hdr->frequency_band = GUINT16_FROM_LE(cv_rf_hdr->frequency_band);
  cv_rf_hdr->channel = GUINT16_FROM_LE(cv_rf_hdr->channel);
  cv_rf_hdr->phy_rate = GUINT32_FROM_LE(cv_rf_hdr->phy_rate);
  cv_rf_hdr->extensions_present = GUINT32_FROM_LE(cv_rf_hdr->extensions_present);

  return true;
}

static bool
commview_ncfx_read_mcs_header(commview_ncfx_mcs_header_t *cv_mcs_hdr, FILE_T fh,
    int *err, char **err_info)
{
  if (!wtap_read_bytes(fh, &cv_mcs_hdr->mcs_index, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_mcs_hdr->n_streams, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_mcs_hdr->channel_width, 1, err, err_info))
    return false;
  if (!wtap_read_bytes(fh, &cv_mcs_hdr->guard_interval, 1, err, err_info))
    return false;

  return true;
}

/* Returns 0 if we can write out the specified encapsulation type
 * into a CommView format file. */
static int
commview_ncfx_dump_can_write_encap(int encap)
{
  switch (encap) {

  case WTAP_ENCAP_ETHERNET :
  case WTAP_ENCAP_IEEE_802_11 :
  case WTAP_ENCAP_IEEE_802_11_WITH_RADIO :
  case WTAP_ENCAP_PER_PACKET :
    return 0;

  default:
    return WTAP_ERR_UNWRITABLE_ENCAP;
  }
}

/* Returns true on success, false on failure;
   sets "*err" to an error code on failure */
static bool
commview_ncfx_dump_open(wtap_dumper *wdh, int *err _U_, char **err_info _U_)
{
  wdh->subtype_write = commview_ncfx_dump;

  /* There is no file header to write out */
  return true;
}

/* Write a record for a packet to a dump file.
 * Returns true on success, false on failure. */
static bool
commview_ncfx_dump(wtap_dumper *wdh, const wtap_rec *rec,
    int *err, char **err_info _U_)
{
  commview_ncfx_header_t cv_hdr = {0};
  struct tm *tm;

  /* We can only write packet records. */
  if (rec->rec_type != REC_TYPE_PACKET) {
    *err = WTAP_ERR_UNWRITABLE_REC_TYPE;
    *err_info = wtap_unwritable_rec_type_err_string(rec);
    return false;
  }

  /* Don't write out anything bigger than we can read.
   * (The length field in packet headers is 16 bits, which
   * imposes a hard limit.) */
  if (rec->rec_header.packet_header.caplen > 65535) {
    *err = WTAP_ERR_PACKET_TOO_LARGE;
    return false;
  }

  cv_hdr.data_len = GUINT32_TO_LE((uint32_t)rec->rec_header.packet_header.caplen);

  tm = localtime(&rec->ts.secs);
  if (tm != NULL) {
    cv_hdr.year = GUINT16_TO_LE(tm->tm_year + 1900);
    cv_hdr.month = tm->tm_mon + 1;
    cv_hdr.day = tm->tm_mday;
    cv_hdr.hours = tm->tm_hour;
    cv_hdr.minutes = tm->tm_min;
    cv_hdr.seconds = tm->tm_sec;
    cv_hdr.usecs = GUINT32_TO_LE(rec->ts.nsecs / 1000);
  } else {
    /*
     * Second before the Epoch.
     */
    cv_hdr.year = GUINT16_TO_LE(1969);
    cv_hdr.month = 12;
    cv_hdr.day = 31;
    cv_hdr.hours = 23;
    cv_hdr.minutes = 59;
    cv_hdr.seconds = 59;
    cv_hdr.usecs = 0;
  }
  cv_hdr.reserved1 = 0;
  cv_hdr.reserved2 = 0;

  switch(rec->rec_header.packet_header.pkt_encap) {

  case WTAP_ENCAP_ETHERNET :
    cv_hdr.medium_type = MEDIUM_ETHERNET;
    cv_hdr.decryption_flag = 0x00;
    cv_hdr.direction = 0x00;  /* what does this mean? */
    break;

  case WTAP_ENCAP_IEEE_802_11 :
    /* XXX - the claim is that the RF header is mandatory */
    cv_hdr.medium_type = MEDIUM_WIFI;
    break;

  case WTAP_ENCAP_IEEE_802_11_WITH_RADIO :
    cv_hdr.medium_type = MEDIUM_WIFI;

#if 0
    switch (rec->rec_header.packet_header.pseudo_header.ieee_802_11.phy) {

    case PHDR_802_11_PHY_11N:
      cv_hdr.status_modulation = STATUS_MODULATION_HT_PHY;
      break;

    case PHDR_802_11_PHY_11AC:
      cv_hdr.status_modulation = STATUS_MODULATION_VHT_PHY;
      break;

    case PHDR_802_11_PHY_11AX:
      cv_hdr.status_modulation = STATUS_MODULATION_HE_PHY;
      break;

    default:
      cv_hdr.status_modulation = 0;
      break;
    }

    /*
     * Pick the band based on the frequency.
     */
    if (rec->rec_header.packet_header.pseudo_header.ieee_802_11.has_frequency) {
      if (rec->rec_header.packet_header.pseudo_header.ieee_802_11.frequency > 2484) {
        /* 5 GHz band */
        cv_hdr.frequency_band = BAND_5GHZ;
      } else {
        /* 2.4 GHz band */
        cv_hdr.frequency_band = BAND_2_4GHZ;
      }
    } else {
      /* Band is unknown. */
      cv_hdr.band = 0;
    }

    cv_hdr.channel =
        rec->rec_header.packet_header.pseudo_header.ieee_802_11.has_channel ?
          rec->rec_header.packet_header.pseudo_header.ieee_802_11.channel :
          0;
    cv_hdr.noise_level_dbm =
        rec->rec_header.packet_header.pseudo_header.ieee_802_11.has_noise_dbm ?
          -rec->rec_header.packet_header.pseudo_header.ieee_802_11.noise_dbm :
          0;
    cv_hdr.signal_level_dbm =
        rec->rec_header.packet_header.pseudo_header.ieee_802_11.has_signal_dbm ?
          -rec->rec_header.packet_header.pseudo_header.ieee_802_11.signal_dbm :
          0;
    cv_hdr.signal_level_percent =
        rec->rec_header.packet_header.pseudo_header.ieee_802_11.has_signal_percent ?
          rec->rec_header.packet_header.pseudo_header.ieee_802_11.signal_percent :
          0;
    cv_hdr.reserved = 0;
    cv_hdr.phy_rate =
        rec->rec_header.packet_header.pseudo_header.ieee_802_11.has_data_rate ?
          (uint32_t)(rec->rec_header.packet_header.pseudo_header.ieee_802_11.data_rate & 0xFF) :
          0;
#endif
    break;

  default :
    *err = WTAP_ERR_UNWRITABLE_ENCAP;
    return false;
  }

  if (!wtap_dump_file_write(wdh, &cv_hdr.data_len, 4, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.year, 2, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.month, 1, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.day, 1, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.hours, 1, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.minutes, 1, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.seconds, 1, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.usecs, 4, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.medium_type, 1, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.decryption_flag, 1, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.direction, 1, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.reserved1, 1, err))
    return false;
  if (!wtap_dump_file_write(wdh, &cv_hdr.reserved2, 1, err))
    return false;

  /* XXX - RF and MCS headers */

  if (!wtap_dump_file_write(wdh, ws_buffer_start_ptr(&rec->data),
      rec->rec_header.packet_header.caplen, err))
    return false;

  return true;
}

static const struct supported_block_type commview_blocks_supported[] = {
  /*
   * We support packet blocks, with no comments or other options.
   */
  { WTAP_BLOCK_PACKET, MULTIPLE_BLOCKS_SUPPORTED, NO_OPTIONS_SUPPORTED }
};

static const struct file_type_subtype_info commview_ncf_info = {
  "TamoSoft CommView NCF", "commview-ncf", "ncf", NULL,
  false, BLOCKS_SUPPORTED(commview_blocks_supported),
  commview_ncf_dump_can_write_encap, commview_ncf_dump_open, NULL
};

static const struct file_type_subtype_info commview_ncfx_info = {
  "TamoSoft CommView NCFX", "commview-ncfx", "ncfx", NULL,
  false, BLOCKS_SUPPORTED(commview_blocks_supported),
  commview_ncfx_dump_can_write_encap, commview_ncfx_dump_open, NULL
};

void register_commview(void)
{
  commview_ncf_file_type_subtype = wtap_register_file_type_subtype(&commview_ncf_info);
  commview_ncfx_file_type_subtype = wtap_register_file_type_subtype(&commview_ncfx_info);

  /*
   * Register name for backwards compatibility with the
   * wtap_filetypes table in Lua.
   *
   * We don't need to register the new type, as the Wireshark
   * version with which we're providing backwards compatibility
   * didn't support the NCFX format.  New code should fetch
   * the file type/subtype with wtap_name_to_file_type_subtype().
   */
  wtap_register_backwards_compatibility_lua_name("COMMVIEW",
      commview_ncf_file_type_subtype);
}

/*
 * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 *
 * Local variables:
 * c-basic-offset: 8
 * tab-width: 8
 * indent-tabs-mode: t
 * End:
 *
 * vi: set shiftwidth=8 tabstop=8 noexpandtab:
 * :indentSize=8:tabSize=8:noTabs=false:
 */

Coverage Report

Created: 2026-05-14 06:28