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wireshark/wiretap/airopeek9.c
Guy Harris b6ff142f60 Add a presence flag field to the packet information structure filled in 
by Wiretap, to indicate whether certain fields in that structure
actually have data in them.

Use the "time stamp present" flag to omit showing time stamp information
for packets (and "packets") that don't have time stamps; don't bother
working very hard to "fake" a time stamp for data files.

Use the "interface ID present" flag to omit the interface ID for packets
that don't have an interface ID.

We don't use the "captured length, separate from packet length, present"
flag to omit the captured length; that flag might be present but equal
to the packet length, and if you want to know if a packet was cut short
by a snapshot length, comparing the values would be the way to do that.

More work is needed to have wiretap/pcapng.c properly report the flags,
e.g. reporting no time stamp being present for a Simple Packet Block.

svn path=/trunk/; revision=41185
2012-02-25 23:24:34 +00:00

617 lines
17 KiB
C
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/* airopeek9.c
* Routines for opening EtherPeek and AiroPeek V9 files
*
* $Id$
*
* Wiretap Library
* Copyright (c) 1998 by Gilbert Ramirez <gram@alumni.rice.edu>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include "wtap-int.h"
#include "file_wrappers.h"
#include "buffer.h"
#include "airopeek9.h"
/* CREDITS
*
* This file decoder could not have been writen without examining
* http://www.varsanofiev.com/inside/airopeekv9.htm, the help from
* Martin Regner and Guy Harris, and the etherpeek.c file.
*/
/*
* NOTE: it says "airopeek" because the first files seen that use this
* format were AiroPeek files; however, EtherPeek files using it have
* also been seen.
*/
/* section header */
typedef struct airopeek_section_header {
gint8 section_id[4];
guint32 section_len;
guint32 section_const;
} airopeek_section_header_t;
/*
* Network subtype values.
*
* XXX - do different network subtype values for 802.11 indicate different
* network adapter types, with some adapters supplying the FCS and others
* not supplying the FCS?
*/
#define AIROPEEK_V9_NST_ETHERNET 0
#define AIROPEEK_V9_NST_802_11 1 /* 802.11 with 0's at the end */
#define AIROPEEK_V9_NST_802_11_2 2 /* 802.11 with 0's at the end */
#define AIROPEEK_V9_NST_802_11_WITH_FCS 3 /* 802.11 with FCS at the end */
/* tags for fields in packet header */
#define TAG_AIROPEEK_V9_LENGTH 0x0000
#define TAG_AIROPEEK_V9_TIMESTAMP_LOWER 0x0001
#define TAG_AIROPEEK_V9_TIMESTAMP_UPPER 0x0002
#define TAG_AIROPEEK_V9_FLAGS_AND_STATUS 0x0003
#define TAG_AIROPEEK_V9_CHANNEL 0x0004
#define TAG_AIROPEEK_V9_RATE 0x0005
#define TAG_AIROPEEK_V9_SIGNAL_PERC 0x0006
#define TAG_AIROPEEK_V9_SIGNAL_DBM 0x0007
#define TAG_AIROPEEK_V9_NOISE_PERC 0x0008
#define TAG_AIROPEEK_V9_NOISE_DBM 0x0009
#define TAG_AIROPEEK_V9_UNKNOWN_0x000D 0x000D
#define TAG_AIROPEEK_V9_SLICE_LENGTH 0xffff
/* 64-bit time in nanoseconds from the (Windows FILETIME) epoch */
typedef struct airopeek_utime {
guint32 upper;
guint32 lower;
} airopeek_utime;
typedef struct {
gboolean has_fcs;
} airopeek9_t;
static gboolean airopeekv9_read(wtap *wth, int *err, gchar **err_info,
gint64 *data_offset);
static gboolean airopeekv9_seek_read(wtap *wth, gint64 seek_off,
union wtap_pseudo_header *pseudo_header, guint8 *pd, int length,
int *err, gchar **err_info);
static int wtap_file_read_pattern (wtap *wth, const char *pattern, int *err,
gchar **err_info)
{
int c;
const char *cp;
cp = pattern;
while (*cp)
{
c = file_getc(wth->fh);
if (c == EOF) {
if (file_eof(wth->fh))
return 0; /* EOF */
else {
*err = file_error(wth->fh, err_info);
return -1; /* error */
}
}
if (c == *cp)
cp++;
else
{
if (c == pattern[0])
cp = &pattern[1];
else
cp = pattern;
}
}
return (*cp == '\0' ? 1 : 0);
}
static int wtap_file_read_till_separator (wtap *wth, char *buffer, int buflen,
const char *separators, int *err,
gchar **err_info)
{
int c;
char *cp;
int i;
for (cp = buffer, i = 0; i < buflen; i++, cp++)
{
c = file_getc(wth->fh);
if (c == EOF) {
if (file_eof(wth->fh))
return 0; /* EOF */
else {
*err = file_error(wth->fh, err_info);
return -1; /* error */
}
}
if (strchr (separators, c) != NULL)
{
*cp = '\0';
break;
}
else
*cp = c;
}
return i;
}
static int wtap_file_read_number (wtap *wth, guint32 *num, int *err,
gchar **err_info)
{
int ret;
char str_num[12];
unsigned long value;
char *p;
ret = wtap_file_read_till_separator (wth, str_num, sizeof (str_num)-1, "<",
err, err_info);
if (ret != 1) {
/* 0 means EOF, which means "not a valid AiroPeek V9 file";
-1 means error, and "err" has been set. */
return ret;
}
value = strtoul (str_num, &p, 10);
if (p == str_num || value > G_MAXUINT32)
return 0;
*num = (guint32)value;
return 1;
}
int airopeek9_open(wtap *wth, int *err, gchar **err_info)
{
airopeek_section_header_t ap_hdr;
int ret;
guint32 fileVersion;
guint32 mediaType;
guint32 mediaSubType = 0;
int file_encap;
static const int airopeek9_encap[] = {
WTAP_ENCAP_ETHERNET,
WTAP_ENCAP_IEEE_802_11_WITH_RADIO,
WTAP_ENCAP_IEEE_802_11_WITH_RADIO,
WTAP_ENCAP_IEEE_802_11_WITH_RADIO
};
#define NUM_AIROPEEK9_ENCAPS (sizeof airopeek9_encap / sizeof airopeek9_encap[0])
airopeek9_t *airopeek9;
wtap_file_read_unknown_bytes(&ap_hdr, sizeof(ap_hdr), wth->fh, err,
err_info);
if (memcmp (ap_hdr.section_id, "\177ver", sizeof(ap_hdr.section_id)) != 0)
return 0; /* doesn't begin with a "\177ver" section */
/*
* XXX - we should get the length of the "\177ver" section, check
* that it's followed by a little-endian 0x00000200, and then,
* when reading the XML, make sure we don't go past the end of
* that section, and skip to the end of that section when
* we have the file version (and possibly check to make sure all
* tags are properly opened and closed).
*/
ret = wtap_file_read_pattern (wth, "<FileVersion>", err, err_info);
if (ret != 1) {
/* 0 means EOF, which means "not a valid AiroPeek V9 file";
-1 means error, and "err" has been set. */
return ret;
}
ret = wtap_file_read_number (wth, &fileVersion, err, err_info);
if (ret != 1) {
/* 0 means EOF, which means "not a valid AiroPeek V9 file";
-1 means error, and "err" has been set. */
return ret;
}
/* If we got this far, we assume it's an AiroPeek V9 file. */
if (fileVersion != 9) {
/* We only support version 9. */
*err = WTAP_ERR_UNSUPPORTED;
*err_info = g_strdup_printf("airopeekv9: version %u unsupported",
fileVersion);
return -1;
}
/*
* XXX - once we've skipped the "\177ver" section, we should
* check for a "sess" section and fail if we don't see it.
* Then we should get the length of the "sess" section, check
* that it's followed by a little-endian 0x00000200, and then,
* when reading the XML, make sure we don't go past the end of
* that section, and skip to the end of the section when
* we have the file version (and possibly check to make sure all
* tags are properly opened and closed).
*/
ret = wtap_file_read_pattern (wth, "<MediaType>", err, err_info);
if (ret == -1)
return -1;
if (ret == 0) {
*err = WTAP_ERR_BAD_FILE;
*err_info = g_strdup("airopeekv9: <MediaType> tag not found");
return -1;
}
/* XXX - this appears to be 0 in both the EtherPeek and AiroPeek
files we've seen; should we require it to be 0? */
ret = wtap_file_read_number (wth, &mediaType, err, err_info);
if (ret == -1)
return -1;
if (ret == 0) {
*err = WTAP_ERR_BAD_FILE;
*err_info = g_strdup("airopeekv9: <MediaType> value not found");
return -1;
}
ret = wtap_file_read_pattern (wth, "<MediaSubType>", err, err_info);
if (ret == -1)
return -1;
if (ret == 0) {
*err = WTAP_ERR_BAD_FILE;
*err_info = g_strdup("airopeekv9: <MediaSubType> tag not found");
return -1;
}
ret = wtap_file_read_number (wth, &mediaSubType, err, err_info);
if (ret == -1)
return -1;
if (ret == 0) {
*err = WTAP_ERR_BAD_FILE;
*err_info = g_strdup("airopeekv9: <MediaSubType> value not found");
return -1;
}
if (mediaSubType >= NUM_AIROPEEK9_ENCAPS
|| airopeek9_encap[mediaSubType] == WTAP_ENCAP_UNKNOWN) {
*err = WTAP_ERR_UNSUPPORTED_ENCAP;
*err_info = g_strdup_printf("airopeekv9: network type %u unknown or unsupported",
mediaSubType);
return -1;
}
ret = wtap_file_read_pattern (wth, "pkts", err, err_info);
if (ret == -1)
return -1;
if (ret == 0) {
*err = WTAP_ERR_SHORT_READ;
return -1;
}
/* skip 8 zero bytes */
if (file_seek (wth->fh, 8L, SEEK_CUR, err) == -1)
return 0;
/*
* This is an EtherPeek or AiroPeek V9 file.
*/
wth->data_offset = file_tell (wth->fh);
file_encap = airopeek9_encap[mediaSubType];
wth->file_type = WTAP_FILE_AIROPEEK_V9;
wth->file_encap = file_encap;
wth->subtype_read = airopeekv9_read;
wth->subtype_seek_read = airopeekv9_seek_read;
wth->tsprecision = WTAP_FILE_TSPREC_NSEC;
airopeek9 = (airopeek9_t *)g_malloc(sizeof(airopeek9_t));
wth->priv = (void *)airopeek9;
switch (mediaSubType) {
case AIROPEEK_V9_NST_ETHERNET:
case AIROPEEK_V9_NST_802_11:
case AIROPEEK_V9_NST_802_11_2:
airopeek9->has_fcs = FALSE;
break;
case AIROPEEK_V9_NST_802_11_WITH_FCS:
airopeek9->has_fcs = TRUE;
break;
}
wth->snapshot_length = 0; /* not available in header */
return 1;
}
typedef struct {
guint32 length;
guint32 sliceLength;
airopeek_utime timestamp;
struct ieee_802_11_phdr ieee_802_11;
} hdr_info_t;
/*
* Process the packet header.
*
* XXX - we should supply the additional radio information;
* the pseudo-header should probably be supplied in a fashion
* similar to the new BSD radio header, so that the 802.11
* dissector can determine which, if any, information items
* are present.
*/
static int
airopeekv9_process_header(FILE_T fh, hdr_info_t *hdr_info, int *err,
gchar **err_info)
{
int header_len = 0;
int bytes_read;
guint8 tag_value[6];
guint16 tag;
gboolean saw_length = FALSE;
gboolean saw_timestamp_lower = FALSE;
gboolean saw_timestamp_upper = FALSE;
/* Extract the fields from the packet header */
do {
/* Get the tag and value.
XXX - this assumes all values are 4 bytes long. */
bytes_read = file_read(tag_value, sizeof tag_value, fh);
if (bytes_read != (int) sizeof tag_value) {
*err = file_error(fh, err_info);
if (*err == 0) {
if (bytes_read > 0)
*err = WTAP_ERR_SHORT_READ;
else if (bytes_read == 0) {
/*
* Short read if we've read something already;
* just an EOF if we haven't.
*/
if (header_len != 0)
*err = WTAP_ERR_SHORT_READ;
}
}
return 0;
}
header_len += (int) sizeof(tag_value);
tag = pletohs(&tag_value[0]);
switch (tag) {
case TAG_AIROPEEK_V9_LENGTH:
if (saw_length) {
*err = WTAP_ERR_BAD_FILE;
*err_info = g_strdup("airopeekv9: record has two length fields");
return 0;
}
hdr_info->length = pletohl(&tag_value[2]);
saw_length = TRUE;
break;
case TAG_AIROPEEK_V9_TIMESTAMP_LOWER:
if (saw_timestamp_lower) {
*err = WTAP_ERR_BAD_FILE;
*err_info = g_strdup("airopeekv9: record has two timestamp-lower fields");
return 0;
}
hdr_info->timestamp.lower = pletohl(&tag_value[2]);
saw_timestamp_lower = TRUE;
break;
case TAG_AIROPEEK_V9_TIMESTAMP_UPPER:
if (saw_timestamp_upper) {
*err = WTAP_ERR_BAD_FILE;
*err_info = g_strdup("airopeekv9: record has two timestamp-upper fields");
return 0;
}
hdr_info->timestamp.upper = pletohl(&tag_value[2]);
saw_timestamp_upper = TRUE;
break;
case TAG_AIROPEEK_V9_FLAGS_AND_STATUS:
/* XXX - not used yet */
break;
case TAG_AIROPEEK_V9_CHANNEL:
hdr_info->ieee_802_11.channel = pletohl(&tag_value[2]);
break;
case TAG_AIROPEEK_V9_RATE:
hdr_info->ieee_802_11.data_rate = pletohl(&tag_value[2]);
break;
case TAG_AIROPEEK_V9_SIGNAL_PERC:
hdr_info->ieee_802_11.signal_level = pletohl(&tag_value[2]);
break;
case TAG_AIROPEEK_V9_SIGNAL_DBM:
/* XXX - not used yet */
break;
case TAG_AIROPEEK_V9_NOISE_PERC:
/* XXX - not used yet */
break;
case TAG_AIROPEEK_V9_NOISE_DBM:
/* XXX - not used yet */
break;
case TAG_AIROPEEK_V9_UNKNOWN_0x000D:
/* XXX - seen in an EtherPeek capture; value unknown */
break;
case TAG_AIROPEEK_V9_SLICE_LENGTH:
hdr_info->sliceLength = pletohl(&tag_value[2]);
break;
default:
break;
}
} while (tag != TAG_AIROPEEK_V9_SLICE_LENGTH); /* last tag */
if (!saw_length) {
*err = WTAP_ERR_BAD_FILE;
*err_info = g_strdup("airopeekv9: record has no length field");
return 0;
}
if (!saw_timestamp_lower) {
*err = WTAP_ERR_BAD_FILE;
*err_info = g_strdup("airopeekv9: record has no timestamp-lower field");
return 0;
}
if (!saw_timestamp_upper) {
*err = WTAP_ERR_BAD_FILE;
*err_info = g_strdup("airopeekv9: record has no timestamp-upper field");
return 0;
}
return header_len;
}
/*
* Time stamps appear to be in nanoseconds since the Windows epoch
* as used in FILETIMEs, i.e. midnight, January 1, 1601.
*
* This magic number came from "nt_time_to_nstime()" in "packet-smb.c".
* 1970-1601 is 369; I'm not sure what the extra 3 days and 6 hours are
* that are being subtracted.
*/
#define TIME_FIXUP_CONSTANT (369.0*365.25*24*60*60-(3.0*24*60*60+6.0*60*60))
static gboolean airopeekv9_read(wtap *wth, int *err, gchar **err_info,
gint64 *data_offset)
{
airopeek9_t *airopeek9 = (airopeek9_t *)wth->priv;
hdr_info_t hdr_info;
int hdrlen;
double t;
*data_offset = wth->data_offset;
/* Process the packet header. */
hdrlen = airopeekv9_process_header(wth->fh, &hdr_info, err, err_info);
if (hdrlen == 0)
return FALSE;
wth->data_offset += hdrlen;
/*
* If sliceLength is 0, force it to be the actual length of the packet.
*/
if (hdr_info.sliceLength == 0)
hdr_info.sliceLength = hdr_info.length;
if (hdr_info.sliceLength > WTAP_MAX_PACKET_SIZE) {
/*
* 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 = g_strdup_printf("airopeek9: File has %u-byte packet, bigger than maximum of %u",
hdr_info.sliceLength, WTAP_MAX_PACKET_SIZE);
return FALSE;
}
wth->phdr.presence_flags = WTAP_HAS_TS|WTAP_HAS_CAP_LEN;
/* fill in packet header length values before slicelength may be
adjusted */
wth->phdr.len = hdr_info.length;
wth->phdr.caplen = hdr_info.sliceLength;
/* read the frame data */
buffer_assure_space(wth->frame_buffer, hdr_info.sliceLength);
wtap_file_read_expected_bytes(buffer_start_ptr(wth->frame_buffer),
hdr_info.sliceLength, wth->fh, err,
err_info);
wth->data_offset += hdr_info.sliceLength;
/* recalculate and fill in packet time stamp */
t = (double) hdr_info.timestamp.lower +
(double) hdr_info.timestamp.upper * 4294967296.0;
t *= 1.0e-9;
t -= TIME_FIXUP_CONSTANT;
wth->phdr.ts.secs = (time_t) t;
wth->phdr.ts.nsecs = (guint32) ((t - wth->phdr.ts.secs)*1000000000);
switch (wth->file_encap) {
case WTAP_ENCAP_IEEE_802_11_WITH_RADIO:
/*
* The last 4 bytes sometimes contains the FCS but on a lot of
* interfaces these are zero. Is there some way to determine
* from the packet header whether it's an FCS or not?
*
* For now, we just discard those bytes; if we can determine
* whether it's an FCS or not, we should use that to determine
* whether to supply it as an FCS or discard it.
*/
wth->pseudo_header.ieee_802_11 = hdr_info.ieee_802_11;
if (airopeek9->has_fcs)
wth->pseudo_header.ieee_802_11.fcs_len = 4;
else {
wth->pseudo_header.ieee_802_11.fcs_len = 0;
wth->phdr.len -= 4;
wth->phdr.caplen -= 4;
}
break;
case WTAP_ENCAP_ETHERNET:
/*
* The last 4 bytes appear to be 0 in the captures I've seen;
* are there any captures where it's an FCS?
*/
wth->pseudo_header.eth.fcs_len = 0;
wth->phdr.len -= 4;
wth->phdr.caplen -= 4;
break;
}
return TRUE;
}
static gboolean
airopeekv9_seek_read(wtap *wth, gint64 seek_off,
union wtap_pseudo_header *pseudo_header, guint8 *pd, int length,
int *err, gchar **err_info)
{
airopeek9_t *airopeek9 = (airopeek9_t *)wth->priv;
hdr_info_t hdr_info;
if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
return FALSE;
/* Process the packet header. */
if (airopeekv9_process_header(wth->random_fh, &hdr_info, err, err_info) == -1)
return FALSE;
switch (wth->file_encap) {
case WTAP_ENCAP_IEEE_802_11_WITH_RADIO:
pseudo_header->ieee_802_11 = hdr_info.ieee_802_11;
if (airopeek9->has_fcs)
pseudo_header->ieee_802_11.fcs_len = 4;
else
pseudo_header->ieee_802_11.fcs_len = 0;
break;
case WTAP_ENCAP_ETHERNET:
pseudo_header->eth.fcs_len = 0;
break;
}
/*
* XXX - should "errno" be set in "wtap_file_read_expected_bytes()"?
*/
errno = WTAP_ERR_CANT_READ;
wtap_file_read_expected_bytes(pd, length, wth->random_fh, err, err_info);
return TRUE;
}
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