2 * Implements a tvbuff for frame
6 * Wireshark - Network traffic analyzer
7 * By Gerald Combs <gerald@wireshark.org>
8 * Copyright 1998 Gerald Combs
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version 2
13 * of the License, or (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
29 #include <epan/packet.h>
30 #include <epan/tvbuff-int.h>
31 #include <epan/tvbuff.h>
33 #include "frame_tvbuff.h"
36 #include "wtap-int.h" /* for ->random_fh */
41 Buffer *buf; /* Packet data */
43 wtap *wth; /**< Wiretap session */
44 gint64 file_off; /**< File offset */
50 frame_read(struct tvb_frame *frame_tvb, struct wtap_pkthdr *phdr, Buffer *buf)
55 /* sanity check, capture file was closed? */
56 if (cfile.wth != frame_tvb->wth)
59 if (!wtap_seek_read(frame_tvb->wth, frame_tvb->file_off, phdr, buf, frame_tvb->tvb.length + frame_tvb->offset, &err, &err_info)) {
61 case WTAP_ERR_UNSUPPORTED_ENCAP:
62 case WTAP_ERR_BAD_FILE:
72 frame_cache(struct tvb_frame *frame_tvb)
74 struct wtap_pkthdr phdr; /* Packet header */
76 if (frame_tvb->buf == NULL) {
77 frame_tvb->buf = (struct Buffer *) g_malloc(sizeof(struct Buffer));
79 /* XXX, register frame_tvb to some list which frees from time to time not used buffers :] */
80 buffer_init(frame_tvb->buf, frame_tvb->tvb.length + frame_tvb->offset);
82 if (!frame_read(frame_tvb, &phdr, frame_tvb->buf))
83 { /* TODO: THROW(???); */ }
86 frame_tvb->tvb.real_data = buffer_start_ptr(frame_tvb->buf) + frame_tvb->offset;
90 frame_free(tvbuff_t *tvb)
92 struct tvb_frame *frame_tvb = (struct tvb_frame *) tvb;
95 buffer_free(frame_tvb->buf);
97 g_free(frame_tvb->buf);
101 static const guint8 *
102 frame_get_ptr(tvbuff_t *tvb, guint abs_offset, guint abs_length _U_)
104 struct tvb_frame *frame_tvb = (struct tvb_frame *) tvb;
106 frame_cache(frame_tvb);
108 return tvb->real_data + abs_offset;
112 frame_memcpy(tvbuff_t *tvb, void *target, guint abs_offset, guint abs_length)
114 struct tvb_frame *frame_tvb = (struct tvb_frame *) tvb;
116 frame_cache(frame_tvb);
118 return memcpy(target, tvb->real_data + abs_offset, abs_length);
122 frame_find_guint8(tvbuff_t *tvb, guint abs_offset, guint limit, guint8 needle)
124 struct tvb_frame *frame_tvb = (struct tvb_frame *) tvb;
125 const guint8 *result;
127 frame_cache(frame_tvb);
129 result = (const guint8 *)memchr(tvb->real_data + abs_offset, needle, limit);
131 return (gint) (result - tvb->real_data);
137 frame_pbrk_guint8(tvbuff_t *tvb, guint abs_offset, guint limit, const guint8 *needles, guchar *found_needle)
139 struct tvb_frame *frame_tvb = (struct tvb_frame *) tvb;
141 frame_cache(frame_tvb);
143 return tvb_pbrk_guint8(tvb, abs_offset, limit, needles, found_needle);
147 frame_offset(const tvbuff_t *tvb _U_, const guint counter)
149 /* XXX: frame_tvb->offset */
153 static tvbuff_t *frame_clone(tvbuff_t *tvb, guint abs_offset, guint abs_length);
155 static const struct tvb_ops tvb_frame_ops = {
156 sizeof(struct tvb_frame), /* size */
158 frame_free, /* free */
159 frame_offset, /* offset */
160 frame_get_ptr, /* get_ptr */
161 frame_memcpy, /* memcpy */
162 frame_find_guint8, /* find_guint8 */
163 frame_pbrk_guint8, /* pbrk_guint8 */
164 frame_clone, /* clone */
167 /* based on tvb_new_real_data() */
169 frame_tvbuff_new(const frame_data *fd, const guint8 *buf)
171 struct tvb_frame *frame_tvb;
174 tvb = tvb_new(&tvb_frame_ops);
177 * XXX - currently, the length arguments in
178 * tvbuff structure are signed, but the captured
179 * and reported length values are unsigned; this means
180 * that length values > 2^31 - 1 will appear as
183 * Captured length values that large will already
184 * have been filtered out by the Wiretap modules
185 * (the file will be reported as corrupted), to
186 * avoid trying to allocate large chunks of data.
188 * Reported length values will not have been
189 * filtered out, and should not be filtered out,
190 * as those lengths are not necessarily invalid.
192 * For now, we clip the reported length at G_MAXINT
194 * (XXX, is this still a problem?) There was an exception when we call
195 * tvb_new_real_data() now there's no one
198 tvb->real_data = buf;
199 tvb->length = fd->cap_len;
200 tvb->reported_length = fd->pkt_len > G_MAXINT ? G_MAXINT : fd->pkt_len;
201 tvb->initialized = TRUE;
204 * This is the top-level real tvbuff for this data source,
205 * so its data source tvbuff is itself.
209 frame_tvb = (struct tvb_frame *) tvb;
211 /* XXX, how to handle fd->file_off == -1 (edited packet) ?? */
212 /* don't care, reassemble code was doing whole copy of data, so it'll work the same */
214 /* XXX, wtap_can_seek() */
215 if (cfile.wth && cfile.wth->random_fh) {
216 frame_tvb->wth = cfile.wth;
217 frame_tvb->file_off = fd->file_off;
218 frame_tvb->offset = 0;
220 frame_tvb->wth = NULL;
222 frame_tvb->buf = NULL;
228 frame_tvbuff_new_buffer(const frame_data *fd, Buffer *buf)
230 return frame_tvbuff_new(fd, buffer_start_ptr(buf));
234 frame_clone(tvbuff_t *tvb, guint abs_offset, guint abs_length)
236 struct tvb_frame *frame_tvb = (struct tvb_frame *) tvb;
238 tvbuff_t *cloned_tvb;
239 struct tvb_frame *cloned_frame_tvb;
241 /* file not seekable */
245 abs_offset += frame_tvb->offset;
247 cloned_tvb = tvb_new(&tvb_frame_ops);
249 /* data will be read when needed */
250 cloned_tvb->real_data = NULL;
251 cloned_tvb->length = abs_length;
252 cloned_tvb->reported_length = abs_length; /* XXX? */
253 cloned_tvb->initialized = TRUE;
256 * This is the top-level real tvbuff for this data source,
257 * so its data source tvbuff is itself.
259 cloned_tvb->ds_tvb = cloned_tvb;
261 cloned_frame_tvb = (struct tvb_frame *) cloned_tvb;
262 cloned_frame_tvb->wth = frame_tvb->wth;
263 cloned_frame_tvb->file_off = frame_tvb->file_off;
264 cloned_frame_tvb->offset = abs_offset;
265 cloned_frame_tvb->buf = NULL;