6 * Copyright (c) 1999 by Bert Driehuis <driehuis@playbeing.org>
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.
31 #include "file_wrappers.h"
33 #include "i4b_trace.h"
37 gboolean byte_swapped;
40 static gboolean i4btrace_read(wtap *wth, int *err, gchar **err_info,
42 static gboolean i4btrace_seek_read(wtap *wth, gint64 seek_off,
43 union wtap_pseudo_header *pseudo_header, guchar *pd, int length,
44 int *err, gchar **err_info);
45 static int i4b_read_rec_header(FILE_T fh, i4b_trace_hdr_t *hdr, int *err);
46 static void i4b_byte_swap_header(wtap *wth, i4b_trace_hdr_t *hdr);
47 static gboolean i4b_read_rec_data(FILE_T fh, guchar *pd, int length, int *err);
48 static void i4b_set_pseudo_header(i4b_trace_hdr_t *hdr,
49 union wtap_pseudo_header *pseudo_header);
52 * Test some fields in the header to see if they make sense.
54 #define I4B_HDR_IS_OK(hdr) \
55 (!((unsigned)hdr.length < 3 || (unsigned)hdr.length > 16384 || \
56 (unsigned)hdr.unit > 4 || (unsigned)hdr.type > 4 || \
57 (unsigned)hdr.dir > 2 || (unsigned)hdr.trunc > 2048))
59 int i4btrace_open(wtap *wth, int *err, gchar **err_info _U_)
63 gboolean byte_swapped = FALSE;
66 /* I4B trace files have no magic in the header... Sigh */
67 errno = WTAP_ERR_CANT_READ;
68 bytes_read = file_read(&hdr, sizeof(hdr), wth->fh);
69 if (bytes_read != sizeof(hdr)) {
70 *err = file_error(wth->fh);
76 /* Silly heuristic... */
77 if (!I4B_HDR_IS_OK(hdr)) {
79 * OK, try byte-swapping the header fields.
81 hdr.length = BSWAP32(hdr.length);
82 hdr.unit = BSWAP32(hdr.unit);
83 hdr.type = BSWAP32(hdr.type);
84 hdr.dir = BSWAP32(hdr.dir);
85 hdr.trunc = BSWAP32(hdr.trunc);
86 if (!I4B_HDR_IS_OK(hdr)) {
88 * It doesn't look valid in either byte order.
94 * It looks valid byte-swapped, so assume it's a
95 * trace written in the opposite byte order.
100 if (file_seek(wth->fh, 0, SEEK_SET, err) == -1)
102 wth->data_offset = 0;
104 /* Get capture start time */
106 wth->file_type = WTAP_FILE_I4BTRACE;
107 i4btrace = (i4btrace_t *)g_malloc(sizeof(i4btrace_t));
108 wth->priv = (void *)i4btrace;
109 wth->subtype_read = i4btrace_read;
110 wth->subtype_seek_read = i4btrace_seek_read;
111 wth->snapshot_length = 0; /* not known */
113 i4btrace->byte_swapped = byte_swapped;
115 wth->file_encap = WTAP_ENCAP_ISDN;
116 wth->tsprecision = WTAP_FILE_TSPREC_USEC;
121 /* Read the next packet */
122 static gboolean i4btrace_read(wtap *wth, int *err, gchar **err_info,
130 /* Read record header. */
131 *data_offset = wth->data_offset;
132 ret = i4b_read_rec_header(wth->fh, &hdr, err);
134 /* Read error or EOF */
137 wth->data_offset += sizeof hdr;
138 i4b_byte_swap_header(wth, &hdr);
139 if (hdr.length < sizeof(hdr)) {
140 *err = WTAP_ERR_BAD_RECORD; /* record length < header! */
141 *err_info = g_strdup_printf("i4btrace: record length %u < header length %lu",
142 hdr.length, (unsigned long)sizeof(hdr));
145 length = hdr.length - (guint32)sizeof(hdr);
147 wth->phdr.len = length;
148 wth->phdr.caplen = length;
150 wth->phdr.ts.secs = hdr.ts_sec;
151 wth->phdr.ts.nsecs = hdr.ts_usec * 1000;
154 * Read the packet data.
156 buffer_assure_space(wth->frame_buffer, length);
157 bufp = buffer_start_ptr(wth->frame_buffer);
158 if (!i4b_read_rec_data(wth->fh, bufp, length, err))
159 return FALSE; /* Read error */
160 wth->data_offset += length;
166 * XXX - what is it? It's probably not WTAP_ENCAP_NULL,
167 * as that means it has a 4-byte AF_ type as the
168 * encapsulation header.
170 wth->phdr.pkt_encap = WTAP_ENCAP_NULL;
179 wth->phdr.pkt_encap = WTAP_ENCAP_ISDN;
183 i4b_set_pseudo_header(&hdr, &wth->pseudo_header);
189 i4btrace_seek_read(wtap *wth, gint64 seek_off,
190 union wtap_pseudo_header *pseudo_header, guchar *pd, int length,
191 int *err, gchar **err_info _U_)
196 if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
199 /* Read record header. */
200 ret = i4b_read_rec_header(wth->random_fh, &hdr, err);
202 /* Read error or EOF */
204 /* EOF means "short read" in random-access mode */
205 *err = WTAP_ERR_SHORT_READ;
209 i4b_byte_swap_header(wth, &hdr);
211 i4b_set_pseudo_header(&hdr, pseudo_header);
214 * Read the packet data.
216 return i4b_read_rec_data(wth->random_fh, pd, length, err);
220 i4b_read_rec_header(FILE_T fh, i4b_trace_hdr_t *hdr, int *err)
224 errno = WTAP_ERR_CANT_READ;
225 bytes_read = file_read(hdr, sizeof *hdr, fh);
226 if (bytes_read != sizeof *hdr) {
227 *err = file_error(fh);
230 if (bytes_read != 0) {
231 *err = WTAP_ERR_SHORT_READ;
240 i4b_byte_swap_header(wtap *wth, i4b_trace_hdr_t *hdr)
242 i4btrace_t *i4btrace = (i4btrace_t *)wth->priv;
244 if (i4btrace->byte_swapped) {
246 * Byte-swap the header.
248 hdr->length = BSWAP32(hdr->length);
249 hdr->unit = BSWAP32(hdr->unit);
250 hdr->type = BSWAP32(hdr->type);
251 hdr->dir = BSWAP32(hdr->dir);
252 hdr->trunc = BSWAP32(hdr->trunc);
253 hdr->count = BSWAP32(hdr->count);
254 hdr->ts_sec = BSWAP32(hdr->ts_sec);
255 hdr->ts_usec = BSWAP32(hdr->ts_usec);
260 i4b_read_rec_data(FILE_T fh, guchar *pd, int length, int *err)
264 errno = WTAP_ERR_CANT_READ;
265 bytes_read = file_read(pd, length, fh);
267 if (bytes_read != length) {
268 *err = file_error(fh);
270 *err = WTAP_ERR_SHORT_READ;
277 i4b_set_pseudo_header(i4b_trace_hdr_t *hdr,
278 union wtap_pseudo_header *pseudo_header)
280 pseudo_header->isdn.uton = (hdr->dir == FROM_TE);
285 * D channel, so it's LAPD; set "p2p.sent".
287 pseudo_header->isdn.channel = 0;
294 pseudo_header->isdn.channel = 1;
301 pseudo_header->isdn.channel = 2;