3 * $Id: i4btrace.c,v 1.24 2004/01/25 21:55:15 guy Exp $
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"
35 static gboolean i4btrace_read(wtap *wth, int *err, gchar **err_info,
37 static gboolean i4btrace_seek_read(wtap *wth, long seek_off,
38 union wtap_pseudo_header *pseudo_header, guchar *pd, int length,
39 int *err, gchar **err_info);
40 static int i4b_read_rec_header(FILE_T fh, i4b_trace_hdr_t *hdr, int *err);
41 static void i4b_byte_swap_header(wtap *wth, i4b_trace_hdr_t *hdr);
42 static gboolean i4b_read_rec_data(FILE_T fh, guchar *pd, int length, int *err);
43 static void i4b_set_pseudo_header(i4b_trace_hdr_t *hdr,
44 union wtap_pseudo_header *pseudo_header);
45 static void i4btrace_close(wtap *wth);
48 * Test some fields in the header to see if they make sense.
50 #define I4B_HDR_IS_OK(hdr) \
51 (!((unsigned)hdr.length < 3 || (unsigned)hdr.unit > 4 || \
52 (unsigned)hdr.type > 4 || (unsigned)hdr.dir > 2 || \
53 (unsigned)hdr.trunc > 2048))
55 int i4btrace_open(wtap *wth, int *err, gchar **err_info _U_)
59 gboolean byte_swapped = FALSE;
61 /* I4B trace files have no magic in the header... Sigh */
62 errno = WTAP_ERR_CANT_READ;
63 bytes_read = file_read(&hdr, 1, sizeof(hdr), wth->fh);
64 if (bytes_read != sizeof(hdr)) {
65 *err = file_error(wth->fh);
71 /* Silly heuristic... */
72 if (!I4B_HDR_IS_OK(hdr)) {
74 * OK, try byte-swapping the header fields.
76 hdr.length = BSWAP32(hdr.length);
77 hdr.unit = BSWAP32(hdr.unit);
78 hdr.type = BSWAP32(hdr.type);
79 hdr.dir = BSWAP32(hdr.dir);
80 hdr.trunc = BSWAP32(hdr.trunc);
81 if (!I4B_HDR_IS_OK(hdr)) {
83 * It doesn't look valid in either byte order.
89 * It looks valid byte-swapped, so assume it's a
90 * trace written in the opposite byte order.
95 if (file_seek(wth->fh, 0, SEEK_SET, err) == -1)
99 /* Get capture start time */
101 wth->file_type = WTAP_FILE_I4BTRACE;
102 wth->capture.i4btrace = g_malloc(sizeof(i4btrace_t));
103 wth->subtype_read = i4btrace_read;
104 wth->subtype_seek_read = i4btrace_seek_read;
105 wth->subtype_close = i4btrace_close;
106 wth->snapshot_length = 0; /* not known */
108 wth->capture.i4btrace->byte_swapped = byte_swapped;
110 wth->file_encap = WTAP_ENCAP_ISDN;
115 /* Read the next packet */
116 static gboolean i4btrace_read(wtap *wth, int *err, gchar **err_info,
124 /* Read record header. */
125 *data_offset = wth->data_offset;
126 ret = i4b_read_rec_header(wth->fh, &hdr, err);
128 /* Read error or EOF */
131 wth->data_offset += sizeof hdr;
132 i4b_byte_swap_header(wth, &hdr);
133 if (hdr.length < sizeof(hdr)) {
134 *err = WTAP_ERR_BAD_RECORD; /* record length < header! */
135 *err_info = g_strdup_printf("i4btrace: record length %u < header length %u",
136 hdr.length, sizeof(hdr));
139 length = hdr.length - sizeof(hdr);
141 wth->phdr.len = length;
142 wth->phdr.caplen = length;
144 wth->phdr.ts.tv_sec = hdr.time.tv_sec;
145 wth->phdr.ts.tv_usec = hdr.time.tv_usec;
148 * Read the packet data.
150 buffer_assure_space(wth->frame_buffer, length);
151 bufp = buffer_start_ptr(wth->frame_buffer);
152 if (!i4b_read_rec_data(wth->fh, bufp, length, err))
153 return FALSE; /* Read error */
154 wth->data_offset += length;
160 * XXX - what is it? It's probably not WTAP_ENCAP_NULL,
161 * as that means it has a 4-byte AF_ type as the
162 * encapsulation header.
164 wth->phdr.pkt_encap = WTAP_ENCAP_NULL;
173 wth->phdr.pkt_encap = WTAP_ENCAP_ISDN;
177 i4b_set_pseudo_header(&hdr, &wth->pseudo_header);
183 i4btrace_seek_read(wtap *wth, long seek_off,
184 union wtap_pseudo_header *pseudo_header, guchar *pd, int length,
185 int *err, gchar **err_info _U_)
190 if (file_seek(wth->random_fh, seek_off, SEEK_SET, err) == -1)
193 /* Read record header. */
194 ret = i4b_read_rec_header(wth->random_fh, &hdr, err);
196 /* Read error or EOF */
198 /* EOF means "short read" in random-access mode */
199 *err = WTAP_ERR_SHORT_READ;
203 i4b_byte_swap_header(wth, &hdr);
205 i4b_set_pseudo_header(&hdr, pseudo_header);
208 * Read the packet data.
210 return i4b_read_rec_data(wth->random_fh, pd, length, err);
214 i4b_read_rec_header(FILE_T fh, i4b_trace_hdr_t *hdr, int *err)
218 errno = WTAP_ERR_CANT_READ;
219 bytes_read = file_read(hdr, 1, sizeof *hdr, fh);
220 if (bytes_read != sizeof *hdr) {
221 *err = file_error(fh);
224 if (bytes_read != 0) {
225 *err = WTAP_ERR_SHORT_READ;
234 i4b_byte_swap_header(wtap *wth, i4b_trace_hdr_t *hdr)
236 if (wth->capture.i4btrace->byte_swapped) {
238 * Byte-swap the header.
240 hdr->length = BSWAP32(hdr->length);
241 hdr->unit = BSWAP32(hdr->unit);
242 hdr->type = BSWAP32(hdr->type);
243 hdr->dir = BSWAP32(hdr->dir);
244 hdr->trunc = BSWAP32(hdr->trunc);
245 hdr->count = BSWAP32(hdr->count);
246 hdr->time.tv_sec = BSWAP32(hdr->time.tv_sec);
247 hdr->time.tv_usec = BSWAP32(hdr->time.tv_usec);
252 i4b_read_rec_data(FILE_T fh, guchar *pd, int length, int *err)
256 errno = WTAP_ERR_CANT_READ;
257 bytes_read = file_read(pd, 1, length, fh);
259 if (bytes_read != length) {
260 *err = file_error(fh);
262 *err = WTAP_ERR_SHORT_READ;
269 i4b_set_pseudo_header(i4b_trace_hdr_t *hdr,
270 union wtap_pseudo_header *pseudo_header)
272 pseudo_header->isdn.uton = (hdr->dir == FROM_TE);
277 * D channel, so it's LAPD; set "p2p.sent".
279 pseudo_header->isdn.channel = 0;
286 pseudo_header->isdn.channel = 1;
293 pseudo_header->isdn.channel = 2;
299 i4btrace_close(wtap *wth)
301 g_free(wth->capture.i4btrace);