3 * $Id: eyesdn.c,v 1.2 2004/02/12 21:25:07 guy Exp $
6 * Copyright (c) 1998 by Gilbert Ramirez <gram@alumni.rice.edu>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version 2
11 * of the License, or (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
29 #include "file_wrappers.h"
36 /* This module reads the output of the EyeSDN USB S0/E1 ISDN probes
37 * They store HDLC frames of D and B channels in a binary format
40 * 1-6 Byte: EyeSDN - Magic
43 * Each Frame starts with the 0xff Flag byte
44 * - Bytes 0-2: timestamp (long usec in network byte order)
45 * - Bytes 3-7: timestamp (40bits sec since 1970 in network byte order)
46 * - Byte 8: channel (0d for D channel, 0e for e channel, b1-ce for B1-B30)
47 * - Byte 9: Sender (0 NT, 1 TE)
48 * - Byte 10-11: frame size in bytes
49 * - Byte 12-n: Frame Payload
51 * All multibyte values are represented in network byte order
52 * The frame is terminated with a flag character (0xff)
53 * bytes 0xff within a frame are escaped using the 0xfe escape character
54 * the byte following the escape character is decremented by two:
55 * so 0xfe 0xfd is actually a 0xff
56 * Characters that need to be escaped are 0xff and 0xfe
60 static int esc_read(guint8 *buf, int len, FILE_T *fh)
65 for(i=0; i<len; i++) {
68 return -2; /* EOF or error */
70 return -1; /* error !!, read into next frame */
72 /* we need to escape */
83 /* Magic text to check for eyesdn-ness of file */
84 static const unsigned char eyesdn_hdr_magic[] =
85 { 'E', 'y', 'e', 'S', 'D', 'N'};
86 #define EYESDN_HDR_MAGIC_SIZE (sizeof(eyesdn_hdr_magic) / sizeof(eyesdn_hdr_magic[0]))
88 /* Magic text for start of packet */
89 static const unsigned char eyesdn_rec_magic[] = { 0xff };
90 #define EYESDN_REC_MAGIC_SIZE (sizeof eyesdn_rec_magic / sizeof eyesdn_rec_magic[0])
92 #define EYESDN_HEADER_LINES_TO_CHECK 1
93 #define EYESDN_HDR_LENGTH 12
94 #define EYESDN_LINE_LENGTH 12
97 * XXX - is this the biggest packet we can get?
99 #define EYESDN_MAX_PACKET_LEN 16384
101 static gboolean eyesdn_read(wtap *wth, int *err, gchar **err_info,
103 static gboolean eyesdn_seek_read(wtap *wth, long seek_off,
104 union wtap_pseudo_header *pseudo_header, guint8 *pd, int len,
105 int *err, gchar **err_info);
106 static gboolean parse_eyesdn_packet_data(FILE_T fh, int pkt_len, guint8* buf,
107 int *err, gchar **err_info);
108 static int parse_eyesdn_rec_hdr(wtap *wth, FILE_T fh,
109 union wtap_pseudo_header *pseudo_header, int *err, gchar **err_info);
111 /* Seeks to the beginning of the next packet, and returns the
112 byte offset. Returns -1 on failure, and sets "*err" to the error. */
113 static long eyesdn_seek_next_packet(wtap *wth, int *err)
118 while ((byte = file_getc(wth->fh)) != EOF) {
120 cur_off = file_tell(wth->fh);
123 *err = file_error(wth->fh);
129 if (file_eof(wth->fh)) {
133 /* We (presumably) got an error (there's no equivalent to "ferror()"
134 in zlib, alas, so we don't have a wrapper to check for an error). */
135 *err = file_error(wth->fh);
140 /* Look through the first part of a file to see if this is
141 * a eyesdn trace file.
143 * Returns TRUE if it is, FALSE if it isn't or if we get an I/O error;
144 * if we get an I/O error, "*err" will be set to a non-zero value.
146 static gboolean eyesdn_check_file_type(wtap *wth, int *err)
148 char buf[EYESDN_HDR_MAGIC_SIZE];
153 reclen=EYESDN_HDR_MAGIC_SIZE;
154 if (file_read(buf, 1, reclen, wth->fh) == reclen) {
156 for (i = 0; i < reclen; i++) {
158 if (byte == eyesdn_hdr_magic[level]) {
160 if (level >= EYESDN_HDR_MAGIC_SIZE) {
167 } else {/* EOF or error. */
168 if (file_eof(wth->fh))
171 *err = file_error(wth->fh);
179 int eyesdn_open(wtap *wth, int *err, gchar **err_info _U_)
181 /* Look for eyesdn header */
182 if (!eyesdn_check_file_type(wth, err)) {
189 wth->data_offset = 0;
190 wth->file_encap = WTAP_ENCAP_ISDN;
191 wth->file_type = WTAP_FILE_EYESDN;
192 wth->snapshot_length = 0; /* not known */
193 wth->subtype_read = eyesdn_read;
194 wth->subtype_seek_read = eyesdn_seek_read;
199 /* Find the next packet and parse it; called from wtap_loop() and wtap_read(). */
200 static gboolean eyesdn_read(wtap *wth, int *err, gchar **err_info,
207 /* Find the next packet */
208 offset = eyesdn_seek_next_packet(wth, err);
212 /* Parse the header */
213 pkt_len = parse_eyesdn_rec_hdr(wth, wth->fh, &wth->pseudo_header, err,
218 /* Make sure we have enough room for the packet */
219 buffer_assure_space(wth->frame_buffer, EYESDN_MAX_PACKET_LEN);
220 buf = buffer_start_ptr(wth->frame_buffer);
222 /* Read the packet data */
223 if (!parse_eyesdn_packet_data(wth->fh, pkt_len, buf, err, err_info))
226 wth->data_offset = offset;
227 *data_offset = offset;
231 /* Used to read packets in random-access fashion */
233 eyesdn_seek_read (wtap *wth, long seek_off,
234 union wtap_pseudo_header *pseudo_header, guint8 *pd, int len,
235 int *err, gchar **err_info)
239 if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
242 pkt_len = parse_eyesdn_rec_hdr(NULL, wth->random_fh, pseudo_header,
245 if (pkt_len != len) {
247 *err = WTAP_ERR_BAD_RECORD;
248 *err_info = g_strdup_printf("eyesdn: requested length %d doesn't match length %d",
254 return parse_eyesdn_packet_data(wth->random_fh, pkt_len, pd, err,
258 /* Parses a packet record header. */
260 parse_eyesdn_rec_hdr(wtap *wth, FILE_T fh,
261 union wtap_pseudo_header *pseudo_header, int *err, gchar **err_info)
263 guint8 hdr[EYESDN_HDR_LENGTH];
264 unsigned long secs, usecs;
266 unsigned int channel, direction;
268 /* Our file pointer should be at the summary information header
269 * for a packet. Read in that header and extract the useful
272 if (esc_read(hdr, EYESDN_HDR_LENGTH, fh) != EYESDN_HDR_LENGTH) {
273 *err = file_error(fh);
275 *err = WTAP_ERR_SHORT_READ;
279 /* extract information from header */
280 usecs = ((unsigned long) hdr[0]);
281 usecs = (usecs << 8) | ((unsigned long) hdr[1]);
282 usecs = (usecs << 8) | ((unsigned long) hdr[2]);
284 secs = ((unsigned long) hdr[3]);
288 secs = (secs << 8) | ((unsigned long) hdr[4]);
289 secs = (secs << 8) | ((unsigned long) hdr[5]);
290 secs = (secs << 8) | ((unsigned long) hdr[6]);
291 secs = (secs << 8) | ((unsigned long) hdr[7]);
295 pkt_len = ((unsigned long) hdr[10]) << 8;
296 pkt_len = (pkt_len << 8) | ((unsigned long) hdr[11]);
300 *err = WTAP_ERR_BAD_RECORD;
301 *err_info = g_strdup_printf("eyesdn: bad channel number %u",
307 *err = WTAP_ERR_BAD_RECORD;
308 *err_info = g_strdup_printf("eyesdn: bad direction value %u",
312 if(pkt_len > EYESDN_MAX_PACKET_LEN) {
313 *err = WTAP_ERR_BAD_RECORD;
314 *err_info = g_strdup_printf("eyesdn: File has %u-byte packet, bigger than maximum of %u",
315 pkt_len, EYESDN_MAX_PACKET_LEN);
320 wth->phdr.ts.tv_sec = secs;
321 wth->phdr.ts.tv_usec = usecs;
322 wth->phdr.caplen = pkt_len;
323 wth->phdr.len = pkt_len;
325 pseudo_header->isdn.uton = direction;
326 pseudo_header->isdn.channel = channel;
333 parse_eyesdn_packet_data(FILE_T fh, int pkt_len, guint8* buf, int *err,
338 errno = WTAP_ERR_CANT_READ;
339 bytes_read = esc_read(buf, pkt_len, fh);
340 if (bytes_read != pkt_len) {
341 if (bytes_read == -2) {
342 *err = file_error(fh);
344 *err = WTAP_ERR_SHORT_READ;
345 } else if (bytes_read == -1) {
346 *err = WTAP_ERR_BAD_RECORD;
347 *err_info = g_strdup("eyesdn: No flag character seen in frame");
349 *err = WTAP_ERR_SHORT_READ;