/*
* Add an Ethernet trailer - which, for some captures, might be the FCS
* rather than a pad-to-60-bytes trailer.
*
* If fcs_len is 0, we assume the frame has no FCS; if it's 4, we assume
* it has an FCS; if it's anything else (such as -1, which means "maybe
* it does, maybe it doesn't"), we try to infer whether it has an FCS.
*/
void
add_ethernet_trailer(packet_info *pinfo, proto_tree *tree, proto_tree *fh_tree,
int trailer_id, tvbuff_t *tvb, tvbuff_t *trailer_tvb, int fcs_len)
{
/* If there're some bytes left over, it could be a combination of:
- padding to meet the minimum 64 byte frame length
- an FCS, if present (if fcs_len is 0, we know it's not present;
if fcs_len is 4, we know it's present; if fcs_len is -1, we
need some heuristics to determine whether it's present)
- information inserted by TAPs or other network monitoring equipment.
If we don't know whether the FCS is present, then, if we don't have a
network monitoring trailer, and if the Ethernet frame was claimed to
have had 64 or more bytes - i.e., it was at least an FCS worth of data
longer than the minimum payload size - we could assume the last 4 bytes
of the trailer are an FCS. */
proto_item *item;
proto_tree *checksum_tree;
if (trailer_tvb) {
guint trailer_length, trailer_reported_length;
guint padding_length = 0;
gboolean has_fcs = FALSE;
tvbuff_t *real_trailer_tvb;
trailer_length = tvb_length(trailer_tvb);
trailer_reported_length = tvb_reported_length(trailer_tvb);
/* There can not have been padding when the length of the frame (including the
trailer) is less than 60 bytes. */
if (eth_assume_padding && pinfo->fd->pkt_len>=60) {
/* Calculate the amount of padding needed for a minimum sized frame */
if ( (pinfo->fd->pkt_len - trailer_reported_length) < 60 )
padding_length = 60 - (pinfo->fd->pkt_len - trailer_reported_length);
/* Add the padding to the tree, unless it should be treated as
part of the trailer and therefor be handed over to (one of)
the ethernet-trailer dissectors */
if (padding_length > 0) {
tvb_ensure_bytes_exist(tvb, 0, padding_length);
proto_tree_add_item(fh_tree, hf_eth_padding, trailer_tvb, 0,
padding_length, ENC_NA);
trailer_length -= padding_length;
trailer_reported_length -= padding_length;
}
}
if (fcs_len != 0) {
/* If fcs_len is 4, we assume we definitely have an FCS.
Otherwise, then, if the frame is big enough that, if we
have a trailer, it probably inclues an FCS, and we have
enough space in the trailer for the FCS, we assume we
have an FCS.
"Big enough" means 64 bytes or more; any frame that big
needs no trailer, as there's no need to pad an Ethernet
packet past 60 bytes.
The trailer must be at least 4 bytes long to have enough
space for an FCS. */
if (fcs_len == 4 || (tvb_reported_length(tvb) >= 64 &&
trailer_reported_length >= 4)) {
/* Either we know we have an FCS, or we believe we have an FCS. */
if (trailer_length < trailer_reported_length) {
/* The packet is claimed to have enough data for a 4-byte FCS,
but we didn't capture all of the packet.
Slice off the 4-byte FCS from the reported length, and
trim the captured length so it's no more than the reported
length; that will slice off what of the FCS, if any, is
in the captured packet. */
trailer_reported_length -= 4;
if (trailer_length > trailer_reported_length)
trailer_length = trailer_reported_length;
has_fcs = TRUE;
} else {
/* We captured all of the packet, including what appears to
be a 4-byte FCS. Slice it off. */
trailer_length -= 4;
trailer_reported_length -= 4;
has_fcs = TRUE;
}
}
}
/* Create a new tvb without the padding and/or the (assumed) fcs */
if (fcs_len==4)
real_trailer_tvb = tvb_new_subset(trailer_tvb, padding_length,
trailer_length, trailer_reported_length);
else
real_trailer_tvb = tvb_new_subset_remaining(trailer_tvb, padding_length);
/* Call all ethernet trailer dissectors to dissect the trailer if
we actually have a trailer. */
if (tvb_reported_length(real_trailer_tvb) != 0) {
if (dissector_try_heuristic(eth_trailer_subdissector_list,
real_trailer_tvb, pinfo, tree, NULL) ) {
/* If we're not sure that there is a FCS, all trailer data
has been given to the ethernet-trailer dissector, so
stop dissecting here */
if (fcs_len!=4)
return;
} else {
/* No luck with the trailer dissectors, so just display the
extra bytes as general trailer */
if (trailer_length != 0) {
tvb_ensure_bytes_exist(tvb, 0, trailer_length);
proto_tree_add_item(fh_tree, trailer_id, real_trailer_tvb, 0,
trailer_length, ENC_NA);
}
}
}
if (has_fcs) {
guint32 sent_fcs = tvb_get_ntohl(trailer_tvb, padding_length+trailer_length);
if(eth_check_fcs){
guint32 fcs = crc32_802_tvb(tvb, tvb_length(tvb) - 4);
if (fcs == sent_fcs) {
item = proto_tree_add_uint_format(fh_tree, hf_eth_fcs, trailer_tvb,
padding_length+trailer_length, 4, sent_fcs,
"Frame check sequence: 0x%08x [correct]", sent_fcs);
checksum_tree = proto_item_add_subtree(item, ett_eth_fcs);
item = proto_tree_add_boolean(checksum_tree, hf_eth_fcs_good, trailer_tvb,
padding_length+trailer_length, 4, TRUE);
PROTO_ITEM_SET_GENERATED(item);
item = proto_tree_add_boolean(checksum_tree, hf_eth_fcs_bad, trailer_tvb,
padding_length+trailer_length, 4, FALSE);
PROTO_ITEM_SET_GENERATED(item);
} else {
item = proto_tree_add_uint_format(fh_tree, hf_eth_fcs, trailer_tvb,
padding_length+trailer_length, 4, sent_fcs,
"Frame check sequence: 0x%08x [incorrect, should be 0x%08x]",
sent_fcs, fcs);
checksum_tree = proto_item_add_subtree(item, ett_eth_fcs);
item = proto_tree_add_boolean(checksum_tree, hf_eth_fcs_good, trailer_tvb,
padding_length+trailer_length, 4, FALSE);
PROTO_ITEM_SET_GENERATED(item);
item = proto_tree_add_boolean(checksum_tree, hf_eth_fcs_bad, trailer_tvb,
padding_length+trailer_length, 4, TRUE);
PROTO_ITEM_SET_GENERATED(item);
expert_add_info_format(pinfo, item, PI_CHECKSUM, PI_ERROR, "Bad checksum");
col_append_str(pinfo->cinfo, COL_INFO, " [ETHERNET FRAME CHECK SEQUENCE INCORRECT]");
}
}else{
item = proto_tree_add_uint_format(fh_tree, hf_eth_fcs, trailer_tvb,
padding_length+trailer_length, 4, sent_fcs,
"Frame check sequence: 0x%08x [validiation disabled]", sent_fcs);
checksum_tree = proto_item_add_subtree(item, ett_eth_fcs);
item = proto_tree_add_boolean(checksum_tree, hf_eth_fcs_good, trailer_tvb,
padding_length+trailer_length, 4, FALSE);
PROTO_ITEM_SET_GENERATED(item);
item = proto_tree_add_boolean(checksum_tree, hf_eth_fcs_bad, trailer_tvb,
padding_length+trailer_length, 4, FALSE);
PROTO_ITEM_SET_GENERATED(item);
}
trailer_length += 4;
}
proto_tree_set_appendix(fh_tree, tvb, tvb_length(tvb) - padding_length - trailer_length, padding_length + trailer_length);
}
}
static void
dissect_radiotap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
proto_tree *radiotap_tree = NULL;
proto_tree *pt, *present_tree = NULL;
proto_tree *ft;
proto_item *ti = NULL, *hidden_item;
int align_offset, offset;
tvbuff_t *next_tvb;
guint32 version;
guint length, length_remaining;
guint32 rate, freq, flags;
gint8 dbm;
guint8 db, rflags;
guint32 present, next_present;
int bit;
/* backward compat with bit 14 == fcs in header */
proto_item *hdr_fcs_ti = NULL;
int hdr_fcs_offset = 0;
guint32 sent_fcs = 0;
guint32 calc_fcs;
struct _radiotap_info *radiotap_info;
static struct _radiotap_info rtp_info_arr[1];
radiotap_info = &rtp_info_arr[0];
col_set_str(pinfo->cinfo, COL_PROTOCOL, "WLAN");
col_clear(pinfo->cinfo, COL_INFO);
offset = 0;
version = tvb_get_guint8(tvb, offset);
length = tvb_get_letohs(tvb, offset+2);
present = tvb_get_letohl(tvb, offset+4);
radiotap_info->radiotap_length = length;
col_add_fstr(pinfo->cinfo, COL_INFO, "Radiotap Capture v%u, Length %u",
version, length);
/* Dissect the packet */
if (tree) {
ti = proto_tree_add_protocol_format(tree, proto_radiotap,
tvb, 0, length, "Radiotap Header v%u, Length %u", version, length);
radiotap_tree = proto_item_add_subtree(ti, ett_radiotap);
proto_tree_add_uint(radiotap_tree, hf_radiotap_version,
tvb, offset, 1, version);
proto_tree_add_item(radiotap_tree, hf_radiotap_pad,
tvb, offset + 1, 1, FALSE);
ti = proto_tree_add_uint(radiotap_tree, hf_radiotap_length,
tvb, offset + 2, 2, length);
}
length_remaining = length;
/*
* FIXME: This only works if there is exactly 1 it_present
* field in the header
*/
if (length_remaining < RADIOTAP_MIN_HEADER_LEN) {
/*
* Radiotap header is shorter than the fixed-length portion
* plus one "present" bitset.
*/
if (tree)
proto_item_append_text(ti, " (bogus - minimum length is 8)");
return;
}
/* Subtree for the "present flags" bitfield. */
if (tree) {
pt = proto_tree_add_uint(radiotap_tree, hf_radiotap_present,
tvb, offset + 4, 4, present);
present_tree = proto_item_add_subtree(pt, ett_radiotap_present);
proto_tree_add_item(present_tree, hf_radiotap_present_tsft,
tvb, offset + 4, 4, TRUE);
proto_tree_add_item(present_tree, hf_radiotap_present_flags,
tvb, offset + 4, 4, TRUE);
proto_tree_add_item(present_tree, hf_radiotap_present_rate,
tvb, offset + 4, 4, TRUE);
proto_tree_add_item(present_tree, hf_radiotap_present_channel,
tvb, offset + 4, 4, TRUE);
proto_tree_add_item(present_tree, hf_radiotap_present_fhss,
tvb, offset + 4, 4, TRUE);
proto_tree_add_item(present_tree, hf_radiotap_present_dbm_antsignal,
tvb, offset + 4, 4, TRUE);
proto_tree_add_item(present_tree, hf_radiotap_present_dbm_antnoise,
tvb, offset + 4, 4, TRUE);
proto_tree_add_item(present_tree, hf_radiotap_present_lock_quality,
tvb, offset + 4, 4, TRUE);
proto_tree_add_item(present_tree, hf_radiotap_present_tx_attenuation,
tvb, offset + 4, 4, TRUE);
proto_tree_add_item(present_tree, hf_radiotap_present_db_tx_attenuation,
tvb, offset + 4, 4, TRUE);
proto_tree_add_item(present_tree, hf_radiotap_present_dbm_tx_attenuation,
tvb, offset + 4, 4, TRUE);
proto_tree_add_item(present_tree, hf_radiotap_present_antenna,
tvb, offset + 4, 4, TRUE);
proto_tree_add_item(present_tree, hf_radiotap_present_db_antsignal,
tvb, offset + 4, 4, TRUE);
proto_tree_add_item(present_tree, hf_radiotap_present_db_antnoise,
tvb, offset + 4, 4, TRUE);
if (radiotap_bit14_fcs) {
proto_tree_add_item(present_tree, hf_radiotap_present_hdrfcs,
tvb, offset + 4, 4, TRUE);
} else {
proto_tree_add_item(present_tree, hf_radiotap_present_rxflags,
tvb, offset + 4, 4, TRUE);
}
proto_tree_add_item(present_tree, hf_radiotap_present_xchannel,
tvb, offset + 4, 4, TRUE);
proto_tree_add_item(present_tree, hf_radiotap_present_ext,
tvb, offset + 4, 4, TRUE);
}
offset += RADIOTAP_MIN_HEADER_LEN;
length_remaining -= RADIOTAP_MIN_HEADER_LEN;
rflags = 0;
for (; present; present = next_present) {
/* clear the least significant bit that is set */
next_present = present & (present - 1);
/* extract the least significant bit that is set */
bit = BITNO_32(present ^ next_present);
switch (bit) {
case IEEE80211_RADIOTAP_TSFT:
align_offset = ALIGN_OFFSET(offset, 8);
offset += align_offset;
length_remaining -= align_offset;
if (length_remaining < 8)
break;
radiotap_info->tsft=tvb_get_letoh64(tvb, offset);
if (tree) {
proto_tree_add_uint64(radiotap_tree, hf_radiotap_mactime,
tvb, offset, 8,radiotap_info->tsft );
}
offset+=8;
length_remaining-=8;
break;
case IEEE80211_RADIOTAP_FLAGS:
{
proto_tree *flags_tree;
if (length_remaining < 1)
break;
rflags = tvb_get_guint8(tvb, offset);
if (tree) {
ft = proto_tree_add_item(radiotap_tree, hf_radiotap_flags,
tvb, offset, 1, FALSE);
flags_tree = proto_item_add_subtree(ft, ett_radiotap_flags);
proto_tree_add_item(flags_tree, hf_radiotap_flags_cfp,
tvb, offset, 1, FALSE);
proto_tree_add_item(flags_tree, hf_radiotap_flags_preamble,
tvb, offset, 1, FALSE);
proto_tree_add_item(flags_tree, hf_radiotap_flags_wep,
tvb, offset, 1, FALSE);
proto_tree_add_item(flags_tree, hf_radiotap_flags_frag,
tvb, offset, 1, FALSE);
proto_tree_add_item(flags_tree, hf_radiotap_flags_fcs,
tvb, offset, 1, FALSE);
proto_tree_add_item(flags_tree, hf_radiotap_flags_datapad,
tvb, offset, 1, FALSE);
proto_tree_add_item(flags_tree, hf_radiotap_flags_badfcs,
tvb, offset, 1, FALSE);
proto_tree_add_item(flags_tree, hf_radiotap_flags_shortgi,
tvb, offset, 1, FALSE);
}
offset++;
length_remaining--;
break;
}
case IEEE80211_RADIOTAP_RATE:
if (length_remaining < 1)
break;
rate = tvb_get_guint8(tvb, offset);
if (rate & 0x80) {
/* XXX adjust by CW and short GI like other sniffers? */
rate = ieee80211_htrates[rate & 0xf];
}
col_add_fstr(pinfo->cinfo, COL_TX_RATE, "%d.%d",
rate / 2, rate & 1 ? 5 : 0);
if (tree) {
proto_tree_add_float_format(radiotap_tree, hf_radiotap_datarate,
tvb, offset, 1, (float)rate / 2,
"Data Rate: %.1f Mb/s", (float)rate / 2);
}
offset++;
length_remaining--;
radiotap_info->rate = rate;
break;
case IEEE80211_RADIOTAP_CHANNEL:
{
proto_item *it;
proto_tree *flags_tree;
gchar *chan_str;
align_offset = ALIGN_OFFSET(offset, 2);
offset += align_offset;
length_remaining -= align_offset;
if (length_remaining < 2)
break;
if (tree) {
freq = tvb_get_letohs(tvb, offset);
flags = tvb_get_letohs(tvb, offset+2);
chan_str = ieee80211_mhz_to_str(freq);
col_add_fstr(pinfo->cinfo, COL_FREQ_CHAN, "%s", chan_str);
proto_tree_add_uint_format(radiotap_tree, hf_radiotap_channel_frequency,
tvb, offset, 2, freq,
"Channel frequency: %s", chan_str);
g_free(chan_str);
/* We're already 2-byte aligned. */
it = proto_tree_add_uint(radiotap_tree, hf_radiotap_channel_flags,
tvb, offset+2, 2, flags);
flags_tree = proto_item_add_subtree(it, ett_radiotap_channel_flags);
proto_tree_add_boolean(flags_tree, hf_radiotap_channel_flags_turbo,
tvb, offset+2, 1, flags);
proto_tree_add_boolean(flags_tree, hf_radiotap_channel_flags_cck,
tvb, offset+2, 1, flags);
proto_tree_add_boolean(flags_tree, hf_radiotap_channel_flags_ofdm,
tvb, offset+2, 1, flags);
proto_tree_add_boolean(flags_tree, hf_radiotap_channel_flags_2ghz,
tvb, offset+2, 1, flags);
proto_tree_add_boolean(flags_tree, hf_radiotap_channel_flags_5ghz,
tvb, offset+3, 1, flags);
proto_tree_add_boolean(flags_tree, hf_radiotap_channel_flags_passive,
tvb, offset+3, 1, flags);
proto_tree_add_boolean(flags_tree, hf_radiotap_channel_flags_dynamic,
tvb, offset+3, 1, flags);
proto_tree_add_boolean(flags_tree, hf_radiotap_channel_flags_gfsk,
tvb, offset+3, 1, flags);
proto_tree_add_boolean(flags_tree, hf_radiotap_channel_flags_gsm,
tvb, offset+3, 1, flags);
proto_tree_add_boolean(flags_tree, hf_radiotap_channel_flags_sturbo,
tvb, offset+3, 1, flags);
proto_tree_add_boolean(flags_tree, hf_radiotap_channel_flags_half,
tvb, offset+3, 1, flags);
proto_tree_add_boolean(flags_tree, hf_radiotap_channel_flags_quarter,
tvb, offset+3, 1, flags);
radiotap_info->freq=freq;
radiotap_info->flags=flags;
}
offset+=4 /* Channel + flags */;
length_remaining-=4;
break;
}
case IEEE80211_RADIOTAP_FHSS:
align_offset = ALIGN_OFFSET(offset, 2);
offset += align_offset;
length_remaining -= align_offset;
if (length_remaining < 2)
break;
proto_tree_add_item(radiotap_tree, hf_radiotap_fhss_hopset,
tvb, offset, 1, FALSE);
proto_tree_add_item(radiotap_tree, hf_radiotap_fhss_pattern,
tvb, offset, 1, FALSE);
offset+=2;
length_remaining-=2;
break;
case IEEE80211_RADIOTAP_DBM_ANTSIGNAL:
if (length_remaining < 1)
break;
dbm = (gint8) tvb_get_guint8(tvb, offset);
col_add_fstr(pinfo->cinfo, COL_RSSI, "%d dBm", dbm);
if (tree) {
proto_tree_add_int_format(radiotap_tree,
hf_radiotap_dbm_antsignal,
tvb, offset, 1, dbm,
"SSI Signal: %d dBm", dbm);
}
offset++;
length_remaining--;
radiotap_info->dbm_antsignal=dbm;
break;
case IEEE80211_RADIOTAP_DBM_ANTNOISE:
if (length_remaining < 1)
break;
dbm = (gint8) tvb_get_guint8(tvb, offset);
if (tree) {
proto_tree_add_int_format(radiotap_tree,
hf_radiotap_dbm_antnoise,
tvb, offset, 1, dbm,
"SSI Noise: %d dBm", dbm);
}
offset++;
length_remaining--;
radiotap_info->dbm_antnoise=dbm;
break;
case IEEE80211_RADIOTAP_LOCK_QUALITY:
align_offset = ALIGN_OFFSET(offset, 2);
offset += align_offset;
length_remaining -= align_offset;
if (length_remaining < 2)
break;
if (tree) {
proto_tree_add_uint(radiotap_tree, hf_radiotap_quality,
tvb, offset, 2, tvb_get_letohs(tvb, offset));
}
offset+=2;
length_remaining-=2;
break;
case IEEE80211_RADIOTAP_TX_ATTENUATION:
align_offset = ALIGN_OFFSET(offset, 2);
offset += align_offset;
length_remaining -= align_offset;
if (length_remaining < 2)
break;
proto_tree_add_item(radiotap_tree, hf_radiotap_tx_attenuation,
tvb, offset, 2, FALSE);
offset+=2;
length_remaining-=2;
break;
case IEEE80211_RADIOTAP_DB_TX_ATTENUATION:
align_offset = ALIGN_OFFSET(offset, 2);
offset += align_offset;
length_remaining -= align_offset;
if (length_remaining < 2)
break;
proto_tree_add_item(radiotap_tree, hf_radiotap_db_tx_attenuation,
tvb, offset, 2, FALSE);
offset+=2;
length_remaining-=2;
break;
case IEEE80211_RADIOTAP_DBM_TX_POWER:
if (length_remaining < 1)
break;
if (tree) {
proto_tree_add_int(radiotap_tree, hf_radiotap_txpower,
tvb, offset, 1, tvb_get_guint8(tvb, offset));
}
offset++;
length_remaining--;
break;
case IEEE80211_RADIOTAP_ANTENNA:
if (length_remaining < 1)
break;
if (tree) {
proto_tree_add_uint(radiotap_tree, hf_radiotap_antenna,
tvb, offset, 1, tvb_get_guint8(tvb, offset));
}
offset++;
length_remaining--;
break;
case IEEE80211_RADIOTAP_DB_ANTSIGNAL:
if (length_remaining < 1)
break;
db = tvb_get_guint8(tvb, offset);
col_add_fstr(pinfo->cinfo, COL_RSSI, "%u dB", db);
if (tree) {
proto_tree_add_uint_format(radiotap_tree,
hf_radiotap_db_antsignal,
tvb, offset, 1, db,
"SSI Signal: %u dB", db);
}
offset++;
length_remaining--;
break;
case IEEE80211_RADIOTAP_DB_ANTNOISE:
if (length_remaining < 1)
break;
db = tvb_get_guint8(tvb, offset);
if (tree) {
proto_tree_add_uint_format(radiotap_tree,
hf_radiotap_db_antnoise,
tvb, offset, 1, db,
"SSI Noise: %u dB", db);
}
offset++;
length_remaining--;
break;
case IEEE80211_RADIOTAP_RX_FLAGS:
{
proto_tree *flags_tree;
if (radiotap_bit14_fcs) {
align_offset = ALIGN_OFFSET(offset, 4);
offset += align_offset;
length_remaining -= align_offset;
if (length_remaining < 4)
break;
if (tree) {
sent_fcs = tvb_get_ntohl(tvb, offset);
hdr_fcs_ti = proto_tree_add_uint(radiotap_tree, hf_radiotap_fcs,
tvb, offset, 4, sent_fcs);
hdr_fcs_offset = offset;
}
offset+=4;
length_remaining-=4;
} else {
proto_item *it;
align_offset = ALIGN_OFFSET(offset, 2);
offset += align_offset;
length_remaining -= align_offset;
if (length_remaining < 2)
break;
if (tree) {
flags = tvb_get_letohs(tvb, offset);
it = proto_tree_add_uint(radiotap_tree, hf_radiotap_rxflags,
tvb, offset, 2, flags);
flags_tree = proto_item_add_subtree(it, ett_radiotap_rxflags);
proto_tree_add_boolean(flags_tree, hf_radiotap_rxflags_badplcp,
tvb, offset, 1, flags);
}
offset+=2;
length_remaining-=2;
}
break;
}
case IEEE80211_RADIOTAP_XCHANNEL:
{
proto_item *it;
proto_tree *flags_tree;
align_offset = ALIGN_OFFSET(offset, 4);
offset += align_offset;
length_remaining -= align_offset;
if (length_remaining < 8)
break;
if (tree) {
int channel;
guint8 maxpower;
flags = tvb_get_letohl(tvb, offset);
freq = tvb_get_letohs(tvb, offset+4);
channel = tvb_get_guint8(tvb, offset+6);
maxpower = tvb_get_guint8(tvb, offset+7);
proto_tree_add_uint(radiotap_tree, hf_radiotap_xchannel,
tvb, offset+6, 1, (guint32) channel);
proto_tree_add_uint(radiotap_tree, hf_radiotap_xchannel_frequency,
tvb, offset+4, 2, freq);
it = proto_tree_add_uint(radiotap_tree, hf_radiotap_xchannel_flags,
tvb, offset+0, 4, flags);
flags_tree = proto_item_add_subtree(it, ett_radiotap_xchannel_flags);
proto_tree_add_boolean(flags_tree, hf_radiotap_xchannel_flags_turbo,
tvb, offset+0, 1, flags);
proto_tree_add_boolean(flags_tree, hf_radiotap_xchannel_flags_cck,
tvb, offset+0, 1, flags);
proto_tree_add_boolean(flags_tree, hf_radiotap_xchannel_flags_ofdm,
tvb, offset+0, 1, flags);
proto_tree_add_boolean(flags_tree, hf_radiotap_xchannel_flags_2ghz,
tvb, offset+0, 1, flags);
proto_tree_add_boolean(flags_tree, hf_radiotap_xchannel_flags_5ghz,
tvb, offset+1, 1, flags);
proto_tree_add_boolean(flags_tree, hf_radiotap_xchannel_flags_passive,
tvb, offset+1, 1, flags);
proto_tree_add_boolean(flags_tree, hf_radiotap_xchannel_flags_dynamic,
tvb, offset+1, 1, flags);
proto_tree_add_boolean(flags_tree, hf_radiotap_xchannel_flags_gfsk,
tvb, offset+1, 1, flags);
proto_tree_add_boolean(flags_tree, hf_radiotap_xchannel_flags_gsm,
tvb, offset+1, 1, flags);
proto_tree_add_boolean(flags_tree, hf_radiotap_xchannel_flags_sturbo,
tvb, offset+1, 1, flags);
proto_tree_add_boolean(flags_tree, hf_radiotap_xchannel_flags_half,
tvb, offset+1, 1, flags);
proto_tree_add_boolean(flags_tree, hf_radiotap_xchannel_flags_quarter,
tvb, offset+1, 1, flags);
proto_tree_add_boolean(flags_tree, hf_radiotap_xchannel_flags_ht20,
tvb, offset+2, 1, flags);
proto_tree_add_boolean(flags_tree, hf_radiotap_xchannel_flags_ht40u,
tvb, offset+2, 1, flags);
proto_tree_add_boolean(flags_tree, hf_radiotap_xchannel_flags_ht40d,
tvb, offset+2, 1, flags);
#if 0
proto_tree_add_uint(radiotap_tree, hf_radiotap_xchannel_maxpower,
tvb, offset+7, 1, maxpower);
#endif
}
offset+=8 /* flags + freq + ieee + maxregpower */;
length_remaining-=8;
break;
}
default:
/*
* This indicates a field whose size we do not
* know, so we cannot proceed.
*/
next_present = 0;
continue;
}
}
/* This handles the case of an FCS exiting at the end of the frame. */
if (rflags & IEEE80211_RADIOTAP_F_FCS)
pinfo->pseudo_header->ieee_802_11.fcs_len = 4;
else
pinfo->pseudo_header->ieee_802_11.fcs_len = 0;
/* Grab the rest of the frame. */
next_tvb = tvb_new_subset_remaining(tvb, length);
/* If we had an in-header FCS, check it.
* This can only happen if the backward-compat configuration option
* is chosen by the user. */
if (hdr_fcs_ti) {
/* It would be very strange for the header to have an FCS for the
* frame *and* the frame to have the FCS at the end, but it's possible, so
* take that into account by using the FCS length recorded in pinfo. */
/* Watch out for [erroneously] short frames */
if (tvb_length(next_tvb) > (unsigned int) pinfo->pseudo_header->ieee_802_11.fcs_len) {
calc_fcs = crc32_802_tvb(next_tvb,
tvb_length(next_tvb) - pinfo->pseudo_header->ieee_802_11.fcs_len);
/* By virtue of hdr_fcs_ti being set, we know that 'tree' is set,
* so there's no need to check it here. */
if (calc_fcs == sent_fcs) {
proto_item_append_text(hdr_fcs_ti, " [correct]");
}
else {
proto_item_append_text(hdr_fcs_ti,
" [incorrect, should be 0x%08x]", calc_fcs);
hidden_item = proto_tree_add_boolean(radiotap_tree, hf_radiotap_fcs_bad,
tvb, hdr_fcs_offset, 4, TRUE);
PROTO_ITEM_SET_HIDDEN(hidden_item);
}
}
else {
proto_item_append_text(hdr_fcs_ti,
" [cannot verify - not enough data]");
}
}
/* dissect the 802.11 header next */
call_dissector((rflags & IEEE80211_RADIOTAP_F_DATAPAD) ?
ieee80211_datapad_handle : ieee80211_handle,
next_tvb, pinfo, tree);
tap_queue_packet(radiotap_tap, pinfo, radiotap_info);
}
