nexmon – Rev 1
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/* eyesdn.c
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "config.h"
#include "wtap-int.h"
#include "eyesdn.h"
#include "file_wrappers.h"
#include <stdlib.h>
#include <string.h>
#include <errno.h>
/* This module reads the output of the EyeSDN USB S0/E1 ISDN probes
* They store HDLC frames of D and B channels in a binary format
* The fileformat is
*
* 1-6 Byte: EyeSDN - Magic
* 7-n Byte: Frames
*
* Each Frame starts with the 0xff Flag byte
* - Bytes 0-2: timestamp (usec in network byte order)
* - Bytes 3-7: timestamp (40bits sec since 1970 in network byte order)
* - Byte 8: channel (0 for D channel, 1-30 for B1-B30)
* - Byte 9: Sender Bit 0(0 NT, 1 TE), Protocol in Bits 7:1, see enum
* - Byte 10-11: frame size in bytes
* - Byte 12-n: Frame Payload
*
* All multibyte values are represented in network byte order
* The frame is terminated with a flag character (0xff)
* bytes 0xff within a frame are escaped using the 0xfe escape character
* the byte following the escape character is decremented by two:
* so 0xfe 0xfd is actually a 0xff
* Characters that need to be escaped are 0xff and 0xfe
*/
static gboolean esc_read(FILE_T fh, guint8 *buf, int len, int *err, gchar **err_info)
{
int i;
int value;
for(i=0; i<len; i++) {
value=file_getc(fh);
if(value==-1) {
/* EOF or error */
*err=file_error(fh, err_info);
if(*err==0)
*err=WTAP_ERR_SHORT_READ;
return FALSE;
}
if(value==0xff) {
/* error !!, read into next frame */
*err=WTAP_ERR_BAD_FILE;
*err_info=g_strdup("eyesdn: No flag character seen in frame");
return FALSE;
}
if(value==0xfe) {
/* we need to escape */
value=file_getc(fh);
if(value==-1) {
/* EOF or error */
*err=file_error(fh, err_info);
if(*err==0)
*err=WTAP_ERR_SHORT_READ;
return FALSE;
}
value+=2;
}
buf[i]=value;
}
return TRUE;
}
/* Magic text to check for eyesdn-ness of file */
static const unsigned char eyesdn_hdr_magic[] =
{ 'E', 'y', 'e', 'S', 'D', 'N'};
#define EYESDN_HDR_MAGIC_SIZE sizeof(eyesdn_hdr_magic)
/* Size of a record header */
#define EYESDN_HDR_LENGTH 12
static gboolean eyesdn_read(wtap *wth, int *err, gchar **err_info,
gint64 *data_offset);
static gboolean eyesdn_seek_read(wtap *wth, gint64 seek_off,
struct wtap_pkthdr *phdr, Buffer *buf, int *err, gchar **err_info);
static int read_eyesdn_rec(FILE_T fh, struct wtap_pkthdr *phdr, Buffer* buf,
int *err, gchar **err_info);
/* Seeks to the beginning of the next packet, and returns the
byte offset. Returns -1 on failure, and sets "*err" to the error
and "*err_info" to null or an additional error string. */
static gint64 eyesdn_seek_next_packet(wtap *wth, int *err, gchar **err_info)
{
int byte;
gint64 cur_off;
while ((byte = file_getc(wth->fh)) != EOF) {
if (byte == 0xff) {
cur_off = file_tell(wth->fh);
if (cur_off == -1) {
/* Error. */
*err = file_error(wth->fh, err_info);
return -1;
}
return cur_off;
}
}
/* EOF or error. */
*err = file_error(wth->fh, err_info);
return -1;
}
wtap_open_return_val eyesdn_open(wtap *wth, int *err, gchar **err_info)
{
char magic[EYESDN_HDR_MAGIC_SIZE];
/* Look for eyesdn header */
if (!wtap_read_bytes(wth->fh, &magic, sizeof magic, err, err_info)) {
if (*err != WTAP_ERR_SHORT_READ)
return WTAP_OPEN_ERROR;
return WTAP_OPEN_NOT_MINE;
}
if (memcmp(magic, eyesdn_hdr_magic, EYESDN_HDR_MAGIC_SIZE) != 0)
return WTAP_OPEN_NOT_MINE;
wth->file_encap = WTAP_ENCAP_PER_PACKET;
wth->file_type_subtype = WTAP_FILE_TYPE_SUBTYPE_EYESDN;
wth->snapshot_length = 0; /* not known */
wth->subtype_read = eyesdn_read;
wth->subtype_seek_read = eyesdn_seek_read;
wth->file_tsprec = WTAP_TSPREC_USEC;
return WTAP_OPEN_MINE;
}
/* Find the next packet and parse it; called from wtap_read(). */
static gboolean eyesdn_read(wtap *wth, int *err, gchar **err_info,
gint64 *data_offset)
{
gint64 offset;
/* Find the next record */
offset = eyesdn_seek_next_packet(wth, err, err_info);
if (offset < 1)
return FALSE;
*data_offset = offset;
/* Parse the record */
return read_eyesdn_rec(wth->fh, &wth->phdr, wth->frame_buffer,
err, err_info);
}
/* Used to read packets in random-access fashion */
static gboolean
eyesdn_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;
return read_eyesdn_rec(wth->random_fh, phdr, buf, err, err_info);
}
/* Parses a record. */
static gboolean
read_eyesdn_rec(FILE_T fh, struct wtap_pkthdr *phdr, Buffer *buf, int *err,
gchar **err_info)
{
union wtap_pseudo_header *pseudo_header = &phdr->pseudo_header;
guint8 hdr[EYESDN_HDR_LENGTH];
time_t secs;
int usecs;
int pkt_len;
guint8 channel, direction;
guint8 *pd;
/* Our file pointer should be at the summary information header
* for a packet. Read in that header and extract the useful
* information.
*/
if (!esc_read(fh, hdr, EYESDN_HDR_LENGTH, err, err_info))
return FALSE;
/* extract information from header */
usecs = pntoh24(&hdr[0]);
#ifdef TV64BITS
secs = hdr[3];
#else
secs = 0;
#endif
secs = (secs << 8) | hdr[4];
secs = (secs << 8) | hdr[5];
secs = (secs << 8) | hdr[6];
secs = (secs << 8) | hdr[7];
channel = hdr[8];
direction = hdr[9];
pkt_len = pntoh16(&hdr[10]);
switch(direction >> 1) {
default:
case EYESDN_ENCAP_ISDN: /* ISDN */
pseudo_header->isdn.uton = direction & 1;
pseudo_header->isdn.channel = channel;
if(channel) { /* bearer channels */
phdr->pkt_encap = WTAP_ENCAP_ISDN; /* recognises PPP */
pseudo_header->isdn.uton=!pseudo_header->isdn.uton; /* bug */
} else { /* D channel */
phdr->pkt_encap = WTAP_ENCAP_ISDN;
}
break;
case EYESDN_ENCAP_MSG: /* Layer 1 message */
phdr->pkt_encap = WTAP_ENCAP_LAYER1_EVENT;
pseudo_header->l1event.uton = (direction & 1);
break;
case EYESDN_ENCAP_LAPB: /* X.25 via LAPB */
phdr->pkt_encap = WTAP_ENCAP_LAPB;
pseudo_header->x25.flags = (direction & 1) ? 0 : 0x80;
break;
case EYESDN_ENCAP_ATM: { /* ATM cells */
#define CELL_LEN 53
unsigned char cell[CELL_LEN];
gint64 cur_off;
if(pkt_len != CELL_LEN) {
*err = WTAP_ERR_BAD_FILE;
*err_info = g_strdup_printf(
"eyesdn: ATM cell has a length != 53 (%u)",
pkt_len);
return FALSE;
}
cur_off = file_tell(fh);
if (!esc_read(fh, cell, CELL_LEN, err, err_info))
return FALSE;
if (file_seek(fh, cur_off, SEEK_SET, err) == -1)
return FALSE;
phdr->pkt_encap = WTAP_ENCAP_ATM_PDUS_UNTRUNCATED;
pseudo_header->atm.flags=ATM_RAW_CELL;
pseudo_header->atm.aal=AAL_UNKNOWN;
pseudo_header->atm.type=TRAF_UMTS_FP;
pseudo_header->atm.subtype=TRAF_ST_UNKNOWN;
pseudo_header->atm.vpi=((cell[0]&0xf)<<4) + (cell[0]&0xf);
pseudo_header->atm.vci=((cell[0]&0xf)<<4) + cell[0]; /* from cell */
pseudo_header->atm.channel=direction & 1;
}
break;
case EYESDN_ENCAP_MTP2: /* SS7 frames */
pseudo_header->mtp2.sent = direction & 1;
pseudo_header->mtp2.annex_a_used = MTP2_ANNEX_A_USED_UNKNOWN;
pseudo_header->mtp2.link_number = channel;
phdr->pkt_encap = WTAP_ENCAP_MTP2_WITH_PHDR;
break;
case EYESDN_ENCAP_DPNSS: /* DPNSS */
pseudo_header->isdn.uton = direction & 1;
pseudo_header->isdn.channel = channel;
phdr->pkt_encap = WTAP_ENCAP_DPNSS;
break;
case EYESDN_ENCAP_DASS2: /* DASS2 frames */
pseudo_header->isdn.uton = direction & 1;
pseudo_header->isdn.channel = channel;
phdr->pkt_encap = WTAP_ENCAP_DPNSS;
break;
case EYESDN_ENCAP_BACNET: /* BACNET async over HDLC frames */
pseudo_header->isdn.uton = direction & 1;
pseudo_header->isdn.channel = channel;
phdr->pkt_encap = WTAP_ENCAP_BACNET_MS_TP_WITH_PHDR;
break;
case EYESDN_ENCAP_V5_EF: /* V5EF */
pseudo_header->isdn.uton = direction & 1;
pseudo_header->isdn.channel = channel;
phdr->pkt_encap = WTAP_ENCAP_V5_EF;
break;
}
if(pkt_len > WTAP_MAX_PACKET_SIZE) {
*err = WTAP_ERR_BAD_FILE;
*err_info = g_strdup_printf("eyesdn: File has %u-byte packet, bigger than maximum of %u",
pkt_len, WTAP_MAX_PACKET_SIZE);
return FALSE;
}
phdr->rec_type = REC_TYPE_PACKET;
phdr->presence_flags = WTAP_HAS_TS;
phdr->ts.secs = secs;
phdr->ts.nsecs = usecs * 1000;
phdr->caplen = pkt_len;
phdr->len = pkt_len;
/* Make sure we have enough room for the packet */
ws_buffer_assure_space(buf, pkt_len);
pd = ws_buffer_start_ptr(buf);
if (!esc_read(fh, pd, pkt_len, err, err_info))
return FALSE;
return TRUE;
}
static gboolean
esc_write(wtap_dumper *wdh, const guint8 *buf, int len, int *err)
{
int i;
guint8 byte;
static const guint8 esc = 0xfe;
for(i=0; i<len; i++) {
byte=buf[i];
if(byte == 0xff || byte == 0xfe) {
/*
* Escape the frame delimiter and escape byte.
*/
if (!wtap_dump_file_write(wdh, &esc, sizeof esc, err))
return FALSE;
byte-=2;
}
if (!wtap_dump_file_write(wdh, &byte, sizeof byte, err))
return FALSE;
}
return TRUE;
}
static gboolean eyesdn_dump(wtap_dumper *wdh,
const struct wtap_pkthdr *phdr,
const guint8 *pd, int *err, gchar **err_info);
gboolean eyesdn_dump_open(wtap_dumper *wdh, int *err)
{
wdh->subtype_write=eyesdn_dump;
if (!wtap_dump_file_write(wdh, eyesdn_hdr_magic,
EYESDN_HDR_MAGIC_SIZE, err))
return FALSE;
wdh->bytes_dumped += EYESDN_HDR_MAGIC_SIZE;
*err=0;
return TRUE;
}
int eyesdn_dump_can_write_encap(int encap)
{
switch (encap) {
case WTAP_ENCAP_ISDN:
case WTAP_ENCAP_LAYER1_EVENT:
case WTAP_ENCAP_DPNSS:
case WTAP_ENCAP_ATM_PDUS_UNTRUNCATED:
case WTAP_ENCAP_LAPB:
case WTAP_ENCAP_MTP2_WITH_PHDR:
case WTAP_ENCAP_BACNET_MS_TP_WITH_PHDR:
case WTAP_ENCAP_PER_PACKET:
return 0;
default:
return WTAP_ERR_UNWRITABLE_ENCAP;
}
}
/* Write a record for a packet to a dump file.
* Returns TRUE on success, FALSE on failure. */
static gboolean eyesdn_dump(wtap_dumper *wdh,
const struct wtap_pkthdr *phdr,
const guint8 *pd, int *err, gchar **err_info _U_)
{
static const guint8 start_flag = 0xff;
const union wtap_pseudo_header *pseudo_header = &phdr->pseudo_header;
guint8 buf[EYESDN_HDR_LENGTH];
int usecs;
time_t secs;
int channel;
int origin;
int protocol;
int size;
/* We can only write packet records. */
if (phdr->rec_type != REC_TYPE_PACKET) {
*err = WTAP_ERR_UNWRITABLE_REC_TYPE;
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 (phdr->caplen > 65535) {
*err = WTAP_ERR_PACKET_TOO_LARGE;
return FALSE;
}
usecs=phdr->ts.nsecs/1000;
secs=phdr->ts.secs;
size=phdr->caplen;
origin = pseudo_header->isdn.uton;
channel = pseudo_header->isdn.channel;
switch(phdr->pkt_encap) {
case WTAP_ENCAP_ISDN:
protocol=EYESDN_ENCAP_ISDN; /* set depending on decoder format and mode */
break;
case WTAP_ENCAP_LAYER1_EVENT:
protocol=EYESDN_ENCAP_MSG;
break;
case WTAP_ENCAP_DPNSS:
protocol=EYESDN_ENCAP_DPNSS;
break;
#if 0
case WTAP_ENCAP_DASS2:
protocol=EYESDN_ENCAP_DASS2;
break;
#endif
case WTAP_ENCAP_ATM_PDUS_UNTRUNCATED:
protocol=EYESDN_ENCAP_ATM;
channel=0x80;
break;
case WTAP_ENCAP_LAPB:
protocol=EYESDN_ENCAP_LAPB;
break;
case WTAP_ENCAP_MTP2_WITH_PHDR:
protocol=EYESDN_ENCAP_MTP2;
break;
case WTAP_ENCAP_BACNET_MS_TP_WITH_PHDR:
protocol=EYESDN_ENCAP_BACNET;
break;
case WTAP_ENCAP_V5_EF:
protocol=EYESDN_ENCAP_V5_EF;
break;
default:
*err=WTAP_ERR_UNWRITABLE_ENCAP;
return FALSE;
}
phton24(&buf[0], usecs);
buf[3] = (guint8)0;
buf[4] = (guint8)(0xff & (secs >> 24));
buf[5] = (guint8)(0xff & (secs >> 16));
buf[6] = (guint8)(0xff & (secs >> 8));
buf[7] = (guint8)(0xff & (secs >> 0));
buf[8] = (guint8) channel;
buf[9] = (guint8) (origin?1:0) + (protocol << 1);
phtons(&buf[10], size);
/* start flag */
if (!wtap_dump_file_write(wdh, &start_flag, sizeof start_flag, err))
return FALSE;
if (!esc_write(wdh, buf, 12, err))
return FALSE;
if (!esc_write(wdh, pd, size, err))
return FALSE;
return TRUE;
}
/*
* 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:
*/