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/* i4btrace.c
*
* Wiretap Library
* Copyright (c) 1999 by Bert Driehuis <driehuis@playbeing.org>
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "config.h"
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include "wtap-int.h"
#include "file_wrappers.h"
#include "i4b_trace.h"
#include "i4btrace.h"
typedef struct {
gboolean byte_swapped;
} i4btrace_t;
static gboolean i4btrace_read(wtap *wth, int *err, gchar **err_info,
gint64 *data_offset);
static gboolean i4btrace_seek_read(wtap *wth, gint64 seek_off,
struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
static int i4b_read_rec(wtap *wth, FILE_T fh, struct wtap_pkthdr *phdr,
Buffer *buf, int *err, gchar **err_info);
/*
* Test some fields in the header to see if they make sense.
*/
#define I4B_HDR_IS_OK(hdr) \
(!((unsigned int)hdr.length < 3 || (unsigned int)hdr.length > 16384 || \
(unsigned int)hdr.unit > 4 || (unsigned int)hdr.type > 4 || \
(unsigned int)hdr.dir > 2 || (unsigned int)hdr.trunc > 2048))
wtap_open_return_val i4btrace_open(wtap *wth, int *err, gchar **err_info)
{
i4b_trace_hdr_t hdr;
gboolean byte_swapped = FALSE;
i4btrace_t *i4btrace;
/* I4B trace files have no magic in the header... Sigh */
if (!wtap_read_bytes(wth->fh, &hdr, sizeof(hdr), err, err_info)) {
if (*err != WTAP_ERR_SHORT_READ)
return WTAP_OPEN_ERROR;
return WTAP_OPEN_NOT_MINE;
}
/* Silly heuristic... */
if (!I4B_HDR_IS_OK(hdr)) {
/*
* OK, try byte-swapping the header fields.
*/
hdr.length = GUINT32_SWAP_LE_BE(hdr.length);
hdr.unit = GUINT32_SWAP_LE_BE(hdr.unit);
hdr.type = GUINT32_SWAP_LE_BE(hdr.type);
hdr.dir = GUINT32_SWAP_LE_BE(hdr.dir);
hdr.trunc = GUINT32_SWAP_LE_BE(hdr.trunc);
if (!I4B_HDR_IS_OK(hdr)) {
/*
* It doesn't look valid in either byte order.
*/
return WTAP_OPEN_NOT_MINE;
}
/*
* It looks valid byte-swapped, so assume it's a
* trace written in the opposite byte order.
*/
byte_swapped = TRUE;
}
if (file_seek(wth->fh, 0, SEEK_SET, err) == -1)
return WTAP_OPEN_ERROR;
/* Get capture start time */
wth->file_type_subtype = WTAP_FILE_TYPE_SUBTYPE_I4BTRACE;
i4btrace = (i4btrace_t *)g_malloc(sizeof(i4btrace_t));
wth->priv = (void *)i4btrace;
wth->subtype_read = i4btrace_read;
wth->subtype_seek_read = i4btrace_seek_read;
wth->snapshot_length = 0; /* not known */
i4btrace->byte_swapped = byte_swapped;
wth->file_encap = WTAP_ENCAP_ISDN;
wth->file_tsprec = WTAP_TSPREC_USEC;
return WTAP_OPEN_MINE;
}
/* Read the next packet */
static gboolean i4btrace_read(wtap *wth, int *err, gchar **err_info,
gint64 *data_offset)
{
*data_offset = file_tell(wth->fh);
return i4b_read_rec(wth, wth->fh, &wth->phdr, wth->frame_buffer,
err, err_info);
}
static gboolean
i4btrace_seek_read(wtap *wth, gint64 seek_off, struct wtap_pkthdr *phdr,
Buffer *buf, int *err, gchar **err_info)
{
if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
return FALSE;
if (!i4b_read_rec(wth, wth->random_fh, phdr, buf, err, err_info)) {
/* Read error or EOF */
if (*err == 0) {
/* EOF means "short read" in random-access mode */
*err = WTAP_ERR_SHORT_READ;
}
return FALSE;
}
return TRUE;
}
static gboolean
i4b_read_rec(wtap *wth, FILE_T fh, struct wtap_pkthdr *phdr, Buffer *buf,
int *err, gchar **err_info)
{
i4btrace_t *i4btrace = (i4btrace_t *)wth->priv;
i4b_trace_hdr_t hdr;
guint32 length;
if (!wtap_read_bytes_or_eof(fh, &hdr, sizeof hdr, err, err_info))
return FALSE;
if (i4btrace->byte_swapped) {
/*
* Byte-swap the header.
*/
hdr.length = GUINT32_SWAP_LE_BE(hdr.length);
hdr.unit = GUINT32_SWAP_LE_BE(hdr.unit);
hdr.type = GUINT32_SWAP_LE_BE(hdr.type);
hdr.dir = GUINT32_SWAP_LE_BE(hdr.dir);
hdr.trunc = GUINT32_SWAP_LE_BE(hdr.trunc);
hdr.count = GUINT32_SWAP_LE_BE(hdr.count);
hdr.ts_sec = GUINT32_SWAP_LE_BE(hdr.ts_sec);
hdr.ts_usec = GUINT32_SWAP_LE_BE(hdr.ts_usec);
}
if (hdr.length < sizeof(hdr)) {
*err = WTAP_ERR_BAD_FILE; /* record length < header! */
*err_info = g_strdup_printf("i4btrace: record length %u < header length %lu",
hdr.length, (unsigned long)sizeof(hdr));
return FALSE;
}
length = hdr.length - (guint32)sizeof(hdr);
if (length > 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("i4btrace: File has %u-byte packet, bigger than maximum of %u",
length, WTAP_MAX_PACKET_SIZE);
return FALSE;
}
phdr->rec_type = REC_TYPE_PACKET;
phdr->presence_flags = WTAP_HAS_TS;
phdr->len = length;
phdr->caplen = length;
phdr->ts.secs = hdr.ts_sec;
phdr->ts.nsecs = hdr.ts_usec * 1000;
switch (hdr.type) {
case TRC_CH_I:
/*
* XXX - what is it? It's probably not WTAP_ENCAP_NULL,
* as that means it has a 4-byte AF_ type as the
* encapsulation header.
*/
phdr->pkt_encap = WTAP_ENCAP_NULL;
break;
case TRC_CH_D:
/*
* D channel, so it's LAPD; set "p2p.sent".
*/
phdr->pkt_encap = WTAP_ENCAP_ISDN;
phdr->pseudo_header.isdn.channel = 0;
break;
case TRC_CH_B1:
/*
* B channel 1.
*/
phdr->pkt_encap = WTAP_ENCAP_ISDN;
phdr->pseudo_header.isdn.channel = 1;
break;
case TRC_CH_B2:
/*
* B channel 2.
*/
phdr->pkt_encap = WTAP_ENCAP_ISDN;
phdr->pseudo_header.isdn.channel = 2;
break;
}
phdr->pseudo_header.isdn.uton = (hdr.dir == FROM_TE);
/*
* Read the packet data.
*/
return wtap_read_packet_bytes(fh, buf, length, err, err_info);
}
/*
* Editor modelines - http://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:
*/
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