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/***************************************************************************
observer.c - description
-------------------
begin : Wed Oct 29 2003
copyright : (C) 2003 by root
email : scotte[AT}netinst.com
***************************************************************************/
/***************************************************************************
* *
* SPDX-License-Identifier: GPL-2.0-or-later *
* *
***************************************************************************/
#include "config.h"
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include "wtap-int.h"
#include "file_wrappers.h"
#include "observer.h"
#include <wsutil/802_11-utils.h>
static const char observer_magic[] = {"ObserverPktBufferVersion=15.00"};
static const int true_magic_length = 17;
static const guint32 observer_packet_magic = 0x88888888;
/*
* This structure is used to keep state when writing files. An instance is
* allocated for each file, and its address is stored in the wtap_dumper.priv
* pointer field.
*/
typedef struct {
guint64 packet_count;
guint8 network_type;
guint32 time_format;
} observer_dump_private_state;
/*
* Some time offsets are calculated in advance here, when the first Observer
* file is opened for reading or writing, and are then used to adjust frame
* timestamps as they are read or written.
*
* The Wiretap API expects timestamps in nanoseconds relative to
* January 1, 1970, 00:00:00 GMT (the Wiretap epoch).
*
* Observer versions before 13.10 encode frame timestamps in nanoseconds
* relative to January 1, 2000, 00:00:00 local time (the Observer epoch).
* Versions 13.10 and later switch over to GMT encoding. Which encoding was used
* when saving the file is identified via the time format TLV following
* the file header.
*
* Unfortunately, even though Observer versions before 13.10 saved in local
* time, they didn't include the timezone from which the frames were captured,
* so converting to GMT correctly from all timezones is impossible. So an
* assumption is made that the file is being read from within the same timezone
* that it was written.
*
* All code herein is normalized to versions 13.10 and later, special casing for
* versions earlier. In other words, timestamps are worked with as if
* they are GMT-encoded, and adjustments from local time are made only if
* the source file warrants it.
*
* All destination files are saved in GMT format.
*/
static const time_t ansi_to_observer_epoch_offset = 946684800;
static time_t gmt_to_localtime_offset = (time_t) -1;
static const char *init_gmt_to_localtime_offset(void)
{
if (gmt_to_localtime_offset == (time_t) -1) {
time_t ansi_epoch_plus_one_day = 86400;
struct tm *tm;
struct tm gmt_tm;
struct tm local_tm;
/*
* Compute the local time zone offset as the number of seconds west
* of GMT. There's no obvious cross-platform API for querying this
* directly. As a workaround, GMT and local tm structures are populated
* relative to the ANSI time_t epoch (plus one day to ensure that
* local time stays after 1970/1/1 00:00:00). They are then converted
* back to time_t as if they were both local times, resulting in the
* time zone offset being the difference between them.
*/
tm = gmtime(&ansi_epoch_plus_one_day);
if (tm == NULL)
return "gmtime(one day past the Epoch) fails (this \"shouldn't happen\")";
gmt_tm = *tm;
tm = localtime(&ansi_epoch_plus_one_day);
if (tm == NULL)
return "localtime(one day past the Epoch) fails (this \"shouldn't happen\")";
local_tm = *tm;
local_tm.tm_isdst = 0;
gmt_to_localtime_offset = mktime(&gmt_tm) - mktime(&local_tm);
}
return NULL;
}
static gboolean observer_read(wtap *wth, wtap_rec *rec, Buffer *buf,
int *err, gchar **err_info, gint64 *data_offset);
static gboolean observer_seek_read(wtap *wth, gint64 seek_off,
wtap_rec *rec, Buffer *buf, int *err, gchar **err_info);
static int read_packet_header(wtap *wth, FILE_T fh, union wtap_pseudo_header *pseudo_header,
packet_entry_header *packet_header, int *err, gchar **err_info);
static gboolean process_packet_header(wtap *wth,
packet_entry_header *packet_header, wtap_rec *rec, int *err,
gchar **err_info);
static int read_packet_data(FILE_T fh, int offset_to_frame, int current_offset_from_packet_header,
Buffer *buf, int length, int *err, char **err_info);
static gboolean skip_to_next_packet(wtap *wth, int offset_to_next_packet,
int current_offset_from_packet_header, int *err, char **err_info);
static gboolean observer_dump(wtap_dumper *wdh, const wtap_rec *rec,
const guint8 *pd, int *err, gchar **err_info);
static gint observer_to_wtap_encap(int observer_encap);
static gint wtap_to_observer_encap(int wtap_encap);
static int observer_file_type_subtype = -1;
void register_observer(void);
wtap_open_return_val observer_open(wtap *wth, int *err, gchar **err_info)
{
guint offset;
capture_file_header file_header;
guint header_offset;
guint i;
tlv_header tlvh;
guint seek_increment;
packet_entry_header packet_header;
observer_dump_private_state * private_state = NULL;
const char *err_str;
offset = 0;
/* read in the buffer file header */
if (!wtap_read_bytes(wth->fh, &file_header, sizeof file_header,
err, err_info)) {
if (*err != WTAP_ERR_SHORT_READ)
return WTAP_OPEN_ERROR;
return WTAP_OPEN_NOT_MINE;
}
offset += (guint)sizeof file_header;
CAPTURE_FILE_HEADER_FROM_LE_IN_PLACE(file_header);
/* check if version info is present */
if (memcmp(file_header.observer_version, observer_magic, true_magic_length)!=0) {
return WTAP_OPEN_NOT_MINE;
}
/* get the location of the first packet */
/* v15 and newer uses high byte offset, in previous versions it will be 0 */
header_offset = file_header.offset_to_first_packet + ((guint)(file_header.offset_to_first_packet_high_byte)<<16);
if (offset > header_offset) {
/*
* The packet data begins before the file header ends.
*/
*err = WTAP_ERR_BAD_FILE;
*err_info = ws_strdup_printf("Observer: The first packet begins in the middle of the file header");
return WTAP_OPEN_ERROR;
}
/* initialize the private state */
private_state = g_new(observer_dump_private_state, 1);
private_state->time_format = TIME_INFO_LOCAL;
wth->priv = (void *) private_state;
/* process extra information */
for (i = 0; i < file_header.number_of_information_elements; i++) {
guint tlv_data_length;
/*
* Make sure reading the TLV header won't put us in the middle
* of the packet data.
*/
if (offset + (guint)sizeof tlvh > header_offset) {
/*
* We're at or past the point where the packet data begins,
* but we have the IE header to read.
*/
*err = WTAP_ERR_BAD_FILE;
*err_info = ws_strdup_printf("Observer: TLVs run into the first packet data");
return WTAP_OPEN_ERROR;
}
/* read the TLV header */
if (!wtap_read_bytes(wth->fh, &tlvh, sizeof tlvh, err, err_info))
return WTAP_OPEN_ERROR;
offset += (guint)sizeof tlvh;
TLV_HEADER_FROM_LE_IN_PLACE(tlvh);
if (tlvh.length < sizeof tlvh) {
*err = WTAP_ERR_BAD_FILE;
*err_info = ws_strdup_printf("Observer: bad record (TLV length %u < %zu)",
tlvh.length, sizeof tlvh);
return WTAP_OPEN_ERROR;
}
tlv_data_length = tlvh.length - (guint)sizeof tlvh;
/*
* Make sure reading the TLV data won't put us in the middle
* of the packet data.
*/
if (offset + tlv_data_length > header_offset) {
/*
* We're at or past the point where the packet data begins,
* but we have the IE data to read.
*/
*err = WTAP_ERR_BAD_FILE;
*err_info = ws_strdup_printf("Observer: TLVs run into the first packet data");
return WTAP_OPEN_ERROR;
}
/* process (or skip over) the current TLV */
switch (tlvh.type) {
case INFORMATION_TYPE_TIME_INFO:
if (tlv_data_length != sizeof private_state->time_format) {
*err = WTAP_ERR_BAD_FILE;
*err_info = ws_strdup_printf("Observer: bad record (time information TLV length %u != %zu)",
tlvh.length,
sizeof tlvh + sizeof private_state->time_format);
return WTAP_OPEN_ERROR;
}
if (!wtap_read_bytes(wth->fh, &private_state->time_format,
sizeof private_state->time_format,
err, err_info))
return WTAP_OPEN_ERROR;
private_state->time_format = GUINT32_FROM_LE(private_state->time_format);
offset += (guint)sizeof private_state->time_format;
break;
default:
if (tlv_data_length != 0) {
if (!wtap_read_bytes(wth->fh, NULL, tlv_data_length, err, err_info))
return WTAP_OPEN_ERROR;
}
offset += tlv_data_length;
}
}
/* get to the first packet */
seek_increment = header_offset - offset;
if (seek_increment != 0) {
if (!wtap_read_bytes(wth->fh, NULL, seek_increment, err, err_info))
return WTAP_OPEN_ERROR;
}
/*
* We assume that all packets in a file have the same network type,
* whether they're data or expert information packets, and thus
* we can attempt to determine the network type by reading the
* first packet.
*
* If that's *not* the case, we need to use WTAP_ENCAP_PER_PACKET.
*
* Read the packet header. Don't assume there *is* a packet;
* if there isn't, report that as a bad file. (If we use
* WTAP_ENCAP_PER_PACKET, we don't need to handle that case, as
* we don't need to read the first packet.
*/
if (!wtap_read_bytes_or_eof(wth->fh, &packet_header, sizeof packet_header,
err, err_info)) {
if (*err == 0) {
/*
* EOF, so there *are* no records.
*/
*err = WTAP_ERR_BAD_FILE;
*err_info = ws_strdup_printf("Observer: No records in the file, so we can't determine the link-layer type");
}
return WTAP_OPEN_ERROR;
}
PACKET_ENTRY_HEADER_FROM_LE_IN_PLACE(packet_header);
/* check the packet's magic number */
if (packet_header.packet_magic != observer_packet_magic) {
*err = WTAP_ERR_UNSUPPORTED;
*err_info = ws_strdup_printf("Observer: unsupported packet version %ul", packet_header.packet_magic);
return WTAP_OPEN_ERROR;
}
/* check the data link type */
if (observer_to_wtap_encap(packet_header.network_type) == WTAP_ENCAP_UNKNOWN) {
*err = WTAP_ERR_UNSUPPORTED;
*err_info = ws_strdup_printf("Observer: network type %u unknown or unsupported", packet_header.network_type);
return WTAP_OPEN_ERROR;
}
wth->file_encap = observer_to_wtap_encap(packet_header.network_type);
/* set up the rest of the capture parameters */
private_state->packet_count = 0;
private_state->network_type = wtap_to_observer_encap(wth->file_encap);
wth->subtype_read = observer_read;
wth->subtype_seek_read = observer_seek_read;
wth->subtype_close = NULL;
wth->subtype_sequential_close = NULL;
wth->snapshot_length = 0; /* not available in header */
wth->file_tsprec = WTAP_TSPREC_NSEC;
wth->file_type_subtype = observer_file_type_subtype;
/* reset the pointer to the first packet */
if (file_seek(wth->fh, header_offset, SEEK_SET, err) == -1)
return WTAP_OPEN_ERROR;
err_str = init_gmt_to_localtime_offset();
if (err_str != NULL) {
*err = WTAP_ERR_INTERNAL;
*err_info = ws_strdup_printf("observer: %s", err_str);
return WTAP_OPEN_ERROR;
}
/*
* Add an IDB; we don't know how many interfaces were
* involved, so we just say one interface, about which
* we only know the link-layer type, snapshot length,
* and time stamp resolution.
*/
wtap_add_generated_idb(wth);
return WTAP_OPEN_MINE;
}
/* Reads the next packet. */
static gboolean observer_read(wtap *wth, wtap_rec *rec, Buffer *buf,
int *err, gchar **err_info, gint64 *data_offset)
{
int header_bytes_consumed;
int data_bytes_consumed;
packet_entry_header packet_header;
/* skip records other than data records */
for (;;) {
*data_offset = file_tell(wth->fh);
/* process the packet header, including TLVs */
header_bytes_consumed = read_packet_header(wth, wth->fh, &rec->rec_header.packet_header.pseudo_header, &packet_header, err,
err_info);
if (header_bytes_consumed <= 0)
return FALSE; /* EOF or error */
if (packet_header.packet_type == PACKET_TYPE_DATA_PACKET)
break;
/* skip to next packet */
if (!skip_to_next_packet(wth, packet_header.offset_to_next_packet,
header_bytes_consumed, err, err_info)) {
return FALSE; /* EOF or error */
}
}
if (!process_packet_header(wth, &packet_header, rec, err, err_info))
return FALSE;
/* read the frame data */
data_bytes_consumed = read_packet_data(wth->fh, packet_header.offset_to_frame,
header_bytes_consumed, buf, rec->rec_header.packet_header.caplen,
err, err_info);
if (data_bytes_consumed < 0) {
return FALSE;
}
/* skip over any extra bytes following the frame data */
if (!skip_to_next_packet(wth, packet_header.offset_to_next_packet,
header_bytes_consumed + data_bytes_consumed, err, err_info)) {
return FALSE;
}
return TRUE;
}
/* Reads a packet at an offset. */
static gboolean observer_seek_read(wtap *wth, gint64 seek_off,
wtap_rec *rec, Buffer *buf, int *err, gchar **err_info)
{
union wtap_pseudo_header *pseudo_header = &rec->rec_header.packet_header.pseudo_header;
packet_entry_header packet_header;
int offset;
int data_bytes_consumed;
if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
return FALSE;
/* process the packet header, including TLVs */
offset = read_packet_header(wth, wth->random_fh, pseudo_header, &packet_header, err,
err_info);
if (offset <= 0)
return FALSE; /* EOF or error */
if (!process_packet_header(wth, &packet_header, rec, err, err_info))
return FALSE;
/* read the frame data */
data_bytes_consumed = read_packet_data(wth->random_fh, packet_header.offset_to_frame,
offset, buf, rec->rec_header.packet_header.caplen, err, err_info);
if (data_bytes_consumed < 0) {
return FALSE;
}
return TRUE;
}
static int
read_packet_header(wtap *wth, FILE_T fh, union wtap_pseudo_header *pseudo_header,
packet_entry_header *packet_header, int *err, gchar **err_info)
{
int offset;
guint i;
tlv_header tlvh;
tlv_wireless_info wireless_header;
offset = 0;
/* pull off the packet header */
if (!wtap_read_bytes_or_eof(fh, packet_header, sizeof *packet_header,
err, err_info)) {
if (*err != 0)
return -1;
return 0; /* EOF */
}
offset += (int)sizeof *packet_header;
PACKET_ENTRY_HEADER_FROM_LE_IN_PLACE(*packet_header);
/* check the packet's magic number */
if (packet_header->packet_magic != observer_packet_magic) {
/*
* Some files are zero-padded at the end. There is no warning of this
* in the previous packet header information, such as setting
* offset_to_next_packet to zero. So detect this situation by treating
* an all-zero header as a sentinel. Return EOF when it is encountered,
* rather than treat it as a bad record.
*/
for (i = 0; i < sizeof *packet_header; i++) {
if (((guint8*) packet_header)[i] != 0)
break;
}
if (i == sizeof *packet_header) {
*err = 0;
return 0; /* EOF */
}
*err = WTAP_ERR_BAD_FILE;
*err_info = ws_strdup_printf("Observer: bad record: Invalid magic number 0x%08x",
packet_header->packet_magic);
return -1;
}
/* initialize the pseudo header */
switch (wth->file_encap) {
case WTAP_ENCAP_ETHERNET:
/* There is no FCS in the frame */
pseudo_header->eth.fcs_len = 0;
break;
case WTAP_ENCAP_IEEE_802_11_WITH_RADIO:
memset(&pseudo_header->ieee_802_11, 0, sizeof(pseudo_header->ieee_802_11));
pseudo_header->ieee_802_11.fcs_len = 0;
pseudo_header->ieee_802_11.decrypted = FALSE;
pseudo_header->ieee_802_11.datapad = FALSE;
pseudo_header->ieee_802_11.phy = PHDR_802_11_PHY_UNKNOWN;
/* Updated below */
break;
}
/* process extra information */
for (i = 0; i < packet_header->number_of_information_elements; i++) {
guint tlv_data_length;
/* read the TLV header */
if (!wtap_read_bytes(fh, &tlvh, sizeof tlvh, err, err_info))
return -1;
offset += (int)sizeof tlvh;
TLV_HEADER_FROM_LE_IN_PLACE(tlvh);
if (tlvh.length < sizeof tlvh) {
*err = WTAP_ERR_BAD_FILE;
*err_info = ws_strdup_printf("Observer: bad record (TLV length %u < %zu)",
tlvh.length, sizeof tlvh);
return -1;
}
tlv_data_length = tlvh.length - (guint)sizeof tlvh;
/* process (or skip over) the current TLV */
switch (tlvh.type) {
case INFORMATION_TYPE_WIRELESS:
if (tlv_data_length != sizeof wireless_header) {
*err = WTAP_ERR_BAD_FILE;
*err_info = ws_strdup_printf("Observer: bad record (wireless TLV length %u != %zu)",
tlvh.length, sizeof tlvh + sizeof wireless_header);
return -1;
}
if (!wtap_read_bytes(fh, &wireless_header, sizeof wireless_header,
err, err_info))
return -1;
/* set decryption status */
/* XXX - what other bits are there in conditions? */
pseudo_header->ieee_802_11.decrypted = (wireless_header.conditions & WIRELESS_WEP_SUCCESS) != 0;
pseudo_header->ieee_802_11.has_channel = TRUE;
pseudo_header->ieee_802_11.channel = wireless_header.frequency;
pseudo_header->ieee_802_11.has_data_rate = TRUE;
pseudo_header->ieee_802_11.data_rate = wireless_header.rate;
pseudo_header->ieee_802_11.has_signal_percent = TRUE;
pseudo_header->ieee_802_11.signal_percent = wireless_header.strengthPercent;
/*
* We don't know they PHY, but we do have the data rate;
* try to guess the PHY based on the data rate and channel.
*/
if (RATE_IS_DSSS(pseudo_header->ieee_802_11.data_rate)) {
/* 11b */
pseudo_header->ieee_802_11.phy = PHDR_802_11_PHY_11B;
pseudo_header->ieee_802_11.phy_info.info_11b.has_short_preamble = FALSE;
} else if (RATE_IS_OFDM(pseudo_header->ieee_802_11.data_rate)) {
/* 11a or 11g, depending on the band. */
if (CHAN_IS_BG(pseudo_header->ieee_802_11.channel)) {
/* 11g */
pseudo_header->ieee_802_11.phy = PHDR_802_11_PHY_11G;
pseudo_header->ieee_802_11.phy_info.info_11g.has_mode = FALSE;
} else {
/* 11a */
pseudo_header->ieee_802_11.phy = PHDR_802_11_PHY_11A;
pseudo_header->ieee_802_11.phy_info.info_11a.has_channel_type = FALSE;
pseudo_header->ieee_802_11.phy_info.info_11a.has_turbo_type = FALSE;
}
}
offset += (int)sizeof wireless_header;
break;
default:
/* skip the TLV data */
if (tlv_data_length != 0) {
if (!wtap_read_bytes(fh, NULL, tlv_data_length, err, err_info))
return -1;
}
offset += tlv_data_length;
}
}
return offset;
}
static gboolean
process_packet_header(wtap *wth, packet_entry_header *packet_header,
wtap_rec *rec, int *err, gchar **err_info)
{
/* set the wiretap record metadata fields */
rec->rec_type = REC_TYPE_PACKET;
rec->block = wtap_block_create(WTAP_BLOCK_PACKET);
rec->presence_flags = WTAP_HAS_TS|WTAP_HAS_CAP_LEN;
rec->rec_header.packet_header.pkt_encap = observer_to_wtap_encap(packet_header->network_type);
if(wth->file_encap == WTAP_ENCAP_FIBRE_CHANNEL_FC2_WITH_FRAME_DELIMS) {
rec->rec_header.packet_header.len = packet_header->network_size;
rec->rec_header.packet_header.caplen = packet_header->captured_size;
} else {
/*
* XXX - what are those 4 bytes?
*
* The comment in the code said "neglect frame markers for wiretap",
* but in the captures I've seen, there's no actual data corresponding
* to them that might be a "frame marker".
*
* Instead, the packets had a network_size 4 bytes larger than the
* captured_size; does the network_size include the CRC, even
* though it's not included in a capture? If so, most other
* network analyzers that have a "network size" and a "captured
* size" don't include the CRC in the "network size" if they
* don't include the CRC in a full-length captured packet; the
* "captured size" is less than the "network size" only if a
* user-specified "snapshot length" caused the packet to be
* sliced at a particular point.
*
* That's the model that wiretap and Wireshark/TShark use, so
* we implement that model here.
*/
if (packet_header->network_size < 4) {
*err = WTAP_ERR_BAD_FILE;
*err_info = ws_strdup_printf("Observer: bad record: Packet length %u < 4",
packet_header->network_size);
return FALSE;
}
rec->rec_header.packet_header.len = packet_header->network_size - 4;
rec->rec_header.packet_header.caplen = MIN(packet_header->captured_size, rec->rec_header.packet_header.len);
}
/*
* The maximum value of packet_header->captured_size is 65535, which
* is less than WTAP_MAX_PACKET_SIZE_STANDARD will ever be, so we don't need
* to check it.
*/
/* set the wiretap timestamp, assuming for the moment that Observer encoded it in GMT */
rec->ts.secs = (time_t) ((packet_header->nano_seconds_since_2000 / 1000000000) + ansi_to_observer_epoch_offset);
rec->ts.nsecs = (int) (packet_header->nano_seconds_since_2000 % 1000000000);
/* adjust to local time, if necessary, also accounting for DST if the frame
was captured while it was in effect */
if (((observer_dump_private_state*)wth->priv)->time_format == TIME_INFO_LOCAL)
{
struct tm *tm;
struct tm daylight_tm;
struct tm standard_tm;
time_t dst_offset;
/* the Observer timestamp was encoded as local time, so add a
correction from local time to GMT */
rec->ts.secs += gmt_to_localtime_offset;
/* perform a DST adjustment if necessary */
tm = localtime(&rec->ts.secs);
if (tm != NULL) {
standard_tm = *tm;
if (standard_tm.tm_isdst > 0) {
daylight_tm = standard_tm;
standard_tm.tm_isdst = 0;
dst_offset = mktime(&standard_tm) - mktime(&daylight_tm);
rec->ts.secs -= dst_offset;
}
}
}
return TRUE;
}
static int
read_packet_data(FILE_T fh, int offset_to_frame, int current_offset_from_packet_header, Buffer *buf,
int length, int *err, char **err_info)
{
int seek_increment;
int bytes_consumed = 0;
/* validate offsets */
if (offset_to_frame < current_offset_from_packet_header) {
*err = WTAP_ERR_BAD_FILE;
*err_info = ws_strdup_printf("Observer: bad record (offset to packet data %d < %d)",
offset_to_frame, current_offset_from_packet_header);
return -1;
}
/* skip to the packet data */
seek_increment = offset_to_frame - current_offset_from_packet_header;
if (seek_increment > 0) {
if (!wtap_read_bytes(fh, NULL, seek_increment, err, err_info)) {
return -1;
}
bytes_consumed += seek_increment;
}
/* read in the packet data */
if (!wtap_read_packet_bytes(fh, buf, length, err, err_info))
return FALSE;
bytes_consumed += length;
return bytes_consumed;
}
static gboolean
skip_to_next_packet(wtap *wth, int offset_to_next_packet, int current_offset_from_packet_header, int *err,
char **err_info)
{
int seek_increment;
/* validate offsets */
if (offset_to_next_packet < current_offset_from_packet_header) {
*err = WTAP_ERR_BAD_FILE;
*err_info = ws_strdup_printf("Observer: bad record (offset to next packet %d < %d)",
offset_to_next_packet, current_offset_from_packet_header);
return FALSE;
}
/* skip to the next packet header */
seek_increment = offset_to_next_packet - current_offset_from_packet_header;
if (seek_increment > 0) {
if (!wtap_read_bytes(wth->fh, NULL, seek_increment, err, err_info))
return FALSE;
}
return TRUE;
}
/* Returns 0 if we could write the specified encapsulation type,
an error indication otherwise. */
static int observer_dump_can_write_encap(int encap)
{
/* per-packet encapsulations aren't supported */
if (encap == WTAP_ENCAP_PER_PACKET)
return WTAP_ERR_ENCAP_PER_PACKET_UNSUPPORTED;
if (encap < 0 || (wtap_to_observer_encap(encap) == OBSERVER_UNDEFINED))
return WTAP_ERR_UNWRITABLE_ENCAP;
return 0;
}
/* Returns TRUE on success, FALSE on failure; sets "*err" to an error code on
failure. */
static gboolean observer_dump_open(wtap_dumper *wdh, int *err,
gchar **err_info)
{
observer_dump_private_state * private_state = NULL;
capture_file_header file_header;
guint header_offset;
const gchar *err_str;
tlv_header comment_header;
char comment[64];
size_t comment_length;
tlv_header time_info_header;
tlv_time_info time_info;
struct tm * current_time;
time_t system_time;
/* initialize the private state */
private_state = g_new(observer_dump_private_state, 1);
private_state->packet_count = 0;
private_state->network_type = wtap_to_observer_encap(wdh->encap);
private_state->time_format = TIME_INFO_GMT;
/* populate the fields of wdh */
wdh->priv = (void *) private_state;
wdh->subtype_write = observer_dump;
/* initialize the file header */
memset(&file_header, 0x00, sizeof(file_header));
(void) g_strlcpy(file_header.observer_version, observer_magic, 31);
header_offset = (guint16)sizeof(file_header);
/* create the file comment TLV */
{
time(&system_time);
current_time = localtime(&system_time);
memset(&comment, 0x00, sizeof(comment));
if (current_time != NULL)
snprintf(comment, 64, "This capture was saved from Wireshark on %s", asctime(current_time));
else
snprintf(comment, 64, "This capture was saved from Wireshark");
comment_length = strlen(comment);
comment_header.type = INFORMATION_TYPE_COMMENT;
comment_header.length = (guint16) (sizeof(comment_header) + comment_length);
/* update the file header to account for the comment TLV */
file_header.number_of_information_elements++;
header_offset += comment_header.length;
}
/* create the timestamp encoding TLV */
{
time_info_header.type = INFORMATION_TYPE_TIME_INFO;
time_info_header.length = (guint16) (sizeof(time_info_header) + sizeof(time_info));
time_info.time_format = TIME_INFO_GMT;
/* update the file header to account for the timestamp encoding TLV */
file_header.number_of_information_elements++;
header_offset += time_info_header.length;
}
/* Store the offset to the first packet */
file_header.offset_to_first_packet_high_byte = (header_offset >> 16);
file_header.offset_to_first_packet = (header_offset & 0xFFFF);
/* write the file header, swapping any multibyte fields first */
CAPTURE_FILE_HEADER_TO_LE_IN_PLACE(file_header);
if (!wtap_dump_file_write(wdh, &file_header, sizeof(file_header), err)) {
return FALSE;
}
wdh->bytes_dumped += sizeof(file_header);
/* write the comment TLV */
{
TLV_HEADER_TO_LE_IN_PLACE(comment_header);
if (!wtap_dump_file_write(wdh, &comment_header, sizeof(comment_header), err)) {
return FALSE;
}
wdh->bytes_dumped += sizeof(comment_header);
if (!wtap_dump_file_write(wdh, &comment, comment_length, err)) {
return FALSE;
}
wdh->bytes_dumped += comment_length;
}
/* write the time info TLV */
{
TLV_HEADER_TO_LE_IN_PLACE(time_info_header);
if (!wtap_dump_file_write(wdh, &time_info_header, sizeof(time_info_header), err)) {
return FALSE;
}
wdh->bytes_dumped += sizeof(time_info_header);
TLV_TIME_INFO_TO_LE_IN_PLACE(time_info);
if (!wtap_dump_file_write(wdh, &time_info, sizeof(time_info), err)) {
return FALSE;
}
wdh->bytes_dumped += sizeof(time_info);
}
err_str = init_gmt_to_localtime_offset();
if (err_str != NULL) {
*err = WTAP_ERR_INTERNAL;
*err_info = ws_strdup_printf("observer: %s", err_str);
return FALSE;
}
return TRUE;
}
/* Write a record for a packet to a dump file.
Returns TRUE on success, FALSE on failure. */
static gboolean observer_dump(wtap_dumper *wdh, const wtap_rec *rec,
const guint8 *pd,
int *err, gchar **err_info _U_)
{
observer_dump_private_state * private_state = NULL;
packet_entry_header packet_header;
guint64 seconds_since_2000;
/* We can only write packet records. */
if (rec->rec_type != REC_TYPE_PACKET) {
*err = WTAP_ERR_UNWRITABLE_REC_TYPE;
return FALSE;
}
/*
* Make sure this packet doesn't have a link-layer type that
* differs from the one for the file.
*/
if (wdh->encap != rec->rec_header.packet_header.pkt_encap) {
*err = WTAP_ERR_ENCAP_PER_PACKET_UNSUPPORTED;
return FALSE;
}
/* The captured size field is 16 bits, so there's a hard limit of
65535. */
if (rec->rec_header.packet_header.caplen > 65535) {
*err = WTAP_ERR_PACKET_TOO_LARGE;
return FALSE;
}
/* convert the number of seconds since epoch from ANSI-relative to
Observer-relative */
if (rec->ts.secs < ansi_to_observer_epoch_offset) {
if(rec->ts.secs > (time_t) 0) {
seconds_since_2000 = rec->ts.secs;
} else {
seconds_since_2000 = (time_t) 0;
}
} else {
seconds_since_2000 = rec->ts.secs - ansi_to_observer_epoch_offset;
}
/* populate the fields of the packet header */
private_state = (observer_dump_private_state *) wdh->priv;
memset(&packet_header, 0x00, sizeof(packet_header));
packet_header.packet_magic = observer_packet_magic;
packet_header.network_speed = 1000000;
packet_header.captured_size = (guint16) rec->rec_header.packet_header.caplen;
packet_header.network_size = (guint16) (rec->rec_header.packet_header.len + 4);
packet_header.offset_to_frame = sizeof(packet_header);
/* XXX - what if this doesn't fit in 16 bits? It's not guaranteed to... */
packet_header.offset_to_next_packet = (guint16)sizeof(packet_header) + rec->rec_header.packet_header.caplen;
packet_header.network_type = private_state->network_type;
packet_header.flags = 0x00;
packet_header.number_of_information_elements = 0;
packet_header.packet_type = PACKET_TYPE_DATA_PACKET;
packet_header.packet_number = private_state->packet_count;
packet_header.original_packet_number = packet_header.packet_number;
packet_header.nano_seconds_since_2000 = seconds_since_2000 * 1000000000 + rec->ts.nsecs;
private_state->packet_count++;
/* write the packet header */
PACKET_ENTRY_HEADER_TO_LE_IN_PLACE(packet_header);
if (!wtap_dump_file_write(wdh, &packet_header, sizeof(packet_header), err)) {
return FALSE;
}
wdh->bytes_dumped += sizeof(packet_header);
/* write the packet data */
if (!wtap_dump_file_write(wdh, pd, rec->rec_header.packet_header.caplen, err)) {
return FALSE;
}
wdh->bytes_dumped += rec->rec_header.packet_header.caplen;
return TRUE;
}
static gint observer_to_wtap_encap(int observer_encap)
{
switch(observer_encap) {
case OBSERVER_ETHERNET:
return WTAP_ENCAP_ETHERNET;
case OBSERVER_TOKENRING:
return WTAP_ENCAP_TOKEN_RING;
case OBSERVER_FIBRE_CHANNEL:
return WTAP_ENCAP_FIBRE_CHANNEL_FC2_WITH_FRAME_DELIMS;
case OBSERVER_WIRELESS_802_11:
return WTAP_ENCAP_IEEE_802_11_WITH_RADIO;
case OBSERVER_UNDEFINED:
return WTAP_ENCAP_UNKNOWN;
}
return WTAP_ENCAP_UNKNOWN;
}
static gint wtap_to_observer_encap(int wtap_encap)
{
switch(wtap_encap) {
case WTAP_ENCAP_ETHERNET:
return OBSERVER_ETHERNET;
case WTAP_ENCAP_TOKEN_RING:
return OBSERVER_TOKENRING;
case WTAP_ENCAP_FIBRE_CHANNEL_FC2_WITH_FRAME_DELIMS:
return OBSERVER_FIBRE_CHANNEL;
case WTAP_ENCAP_UNKNOWN:
return OBSERVER_UNDEFINED;
}
return OBSERVER_UNDEFINED;
}
static const struct supported_block_type observer_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 observer_info = {
"Viavi Observer", "observer", "bfr", NULL,
FALSE, BLOCKS_SUPPORTED(observer_blocks_supported),
observer_dump_can_write_encap, observer_dump_open, NULL
};
void register_observer(void)
{
observer_file_type_subtype = wtap_register_file_type_subtype(&observer_info);
/*
* We now call this file format just "observer", but we allow
* it to be referred to as "niobserver" for backwards
* compatibility.
*
* Register "niobserver" for that purpose.
*/
wtap_register_compatibility_file_subtype_name("niobserver", "observer");
/*
* Register name for backwards compatibility with the
* wtap_filetypes table in Lua.
*/
wtap_register_backwards_compatibility_lua_name("NETWORK_INSTRUMENTS",
observer_file_type_subtype);
}
/*
* Editor modelines - https://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* vi: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/
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