2 * Implements a tvbuff for frame
4 * Wireshark - Network traffic analyzer
5 * By Gerald Combs <gerald@wireshark.org>
6 * Copyright 1998 Gerald Combs
8 * SPDX-License-Identifier: GPL-2.0+
15 #include <epan/packet.h>
16 #include <epan/tvbuff-int.h>
17 #include <epan/tvbuff.h>
19 #include "frame_tvbuff.h"
21 #include "wiretap/wtap-int.h" /* for ->random_fh */
26 Buffer *buf; /* Packet data */
28 const struct packet_provider_data *prov; /* provider of packet information */
29 gint64 file_off; /**< File offset */
35 frame_read(struct tvb_frame *frame_tvb, struct wtap_pkthdr *phdr, Buffer *buf)
40 /* XXX, what if phdr->caplen isn't equal to
41 * frame_tvb->tvb.length + frame_tvb->offset?
43 if (!wtap_seek_read(frame_tvb->prov->wth, frame_tvb->file_off, phdr, buf, &err, &err_info)) {
44 /* XXX - report error! */
46 case WTAP_ERR_BAD_FILE:
55 static GPtrArray *buffer_cache = NULL;
58 frame_cache(struct tvb_frame *frame_tvb)
60 struct wtap_pkthdr phdr; /* Packet header */
62 wtap_phdr_init(&phdr);
64 if (frame_tvb->buf == NULL) {
65 if G_UNLIKELY(!buffer_cache) buffer_cache = g_ptr_array_sized_new(1024);
67 if (buffer_cache->len > 0) {
68 frame_tvb->buf = (struct Buffer *) g_ptr_array_remove_index(buffer_cache, buffer_cache->len - 1);
70 frame_tvb->buf = (struct Buffer *) g_malloc(sizeof(struct Buffer));
73 ws_buffer_init(frame_tvb->buf, frame_tvb->tvb.length + frame_tvb->offset);
75 if (!frame_read(frame_tvb, &phdr, frame_tvb->buf))
76 { /* TODO: THROW(???); */ }
79 frame_tvb->tvb.real_data = ws_buffer_start_ptr(frame_tvb->buf) + frame_tvb->offset;
81 wtap_phdr_cleanup(&phdr);
85 frame_free(tvbuff_t *tvb)
87 struct tvb_frame *frame_tvb = (struct tvb_frame *) tvb;
90 ws_buffer_free(frame_tvb->buf);
91 g_ptr_array_add(buffer_cache, frame_tvb->buf);
96 frame_get_ptr(tvbuff_t *tvb, guint abs_offset, guint abs_length _U_)
98 struct tvb_frame *frame_tvb = (struct tvb_frame *) tvb;
100 frame_cache(frame_tvb);
102 return tvb->real_data + abs_offset;
106 frame_memcpy(tvbuff_t *tvb, void *target, guint abs_offset, guint abs_length)
108 struct tvb_frame *frame_tvb = (struct tvb_frame *) tvb;
110 frame_cache(frame_tvb);
112 return memcpy(target, tvb->real_data + abs_offset, abs_length);
116 frame_find_guint8(tvbuff_t *tvb, guint abs_offset, guint limit, guint8 needle)
118 struct tvb_frame *frame_tvb = (struct tvb_frame *) tvb;
119 const guint8 *result;
121 frame_cache(frame_tvb);
123 result = (const guint8 *)memchr(tvb->real_data + abs_offset, needle, limit);
125 return (gint) (result - tvb->real_data);
131 frame_pbrk_guint8(tvbuff_t *tvb, guint abs_offset, guint limit, const ws_mempbrk_pattern* pattern, guchar *found_needle)
133 struct tvb_frame *frame_tvb = (struct tvb_frame *) tvb;
135 frame_cache(frame_tvb);
137 return tvb_ws_mempbrk_pattern_guint8(tvb, abs_offset, limit, pattern, found_needle);
141 frame_offset(const tvbuff_t *tvb _U_, const guint counter)
143 /* XXX: frame_tvb->offset */
147 static tvbuff_t *frame_clone(tvbuff_t *tvb, guint abs_offset, guint abs_length);
149 static const struct tvb_ops tvb_frame_ops = {
150 sizeof(struct tvb_frame), /* size */
152 frame_free, /* free */
153 frame_offset, /* offset */
154 frame_get_ptr, /* get_ptr */
155 frame_memcpy, /* memcpy */
156 frame_find_guint8, /* find_guint8 */
157 frame_pbrk_guint8, /* pbrk_guint8 */
158 frame_clone, /* clone */
161 /* based on tvb_new_real_data() */
163 frame_tvbuff_new(const struct packet_provider_data *prov, const frame_data *fd,
166 struct tvb_frame *frame_tvb;
169 tvb = tvb_new(&tvb_frame_ops);
172 * XXX - currently, the length arguments in
173 * tvbuff structure are signed, but the captured
174 * and reported length values are unsigned; this means
175 * that length values > 2^31 - 1 will appear as
178 * Captured length values that large will already
179 * have been filtered out by the Wiretap modules
180 * (the file will be reported as corrupted), to
181 * avoid trying to allocate large chunks of data.
183 * Reported length values will not have been
184 * filtered out, and should not be filtered out,
185 * as those lengths are not necessarily invalid.
187 * For now, we clip the reported length at G_MAXINT
189 * (XXX, is this still a problem?) There was an exception when we call
190 * tvb_new_real_data() now there's no one
193 tvb->real_data = buf;
194 tvb->length = fd->cap_len;
195 tvb->reported_length = fd->pkt_len > G_MAXINT ? G_MAXINT : fd->pkt_len;
196 tvb->initialized = TRUE;
199 * This is the top-level real tvbuff for this data source,
200 * so its data source tvbuff is itself.
204 frame_tvb = (struct tvb_frame *) tvb;
206 /* XXX, wtap_can_seek() */
207 if (prov->wth && prov->wth->random_fh) {
208 frame_tvb->prov = prov;
209 frame_tvb->file_off = fd->file_off;
210 frame_tvb->offset = 0;
212 frame_tvb->prov = NULL;
214 frame_tvb->buf = NULL;
220 frame_tvbuff_new_buffer(const struct packet_provider_data *prov,
221 const frame_data *fd, Buffer *buf)
223 return frame_tvbuff_new(prov, fd, ws_buffer_start_ptr(buf));
227 frame_clone(tvbuff_t *tvb, guint abs_offset, guint abs_length)
229 struct tvb_frame *frame_tvb = (struct tvb_frame *) tvb;
231 tvbuff_t *cloned_tvb;
232 struct tvb_frame *cloned_frame_tvb;
234 /* file not seekable */
235 if (!frame_tvb->prov)
238 abs_offset += frame_tvb->offset;
240 cloned_tvb = tvb_new(&tvb_frame_ops);
242 /* data will be read when needed */
243 cloned_tvb->real_data = NULL;
244 cloned_tvb->length = abs_length;
245 cloned_tvb->reported_length = abs_length; /* XXX? */
246 cloned_tvb->initialized = TRUE;
249 * This is the top-level real tvbuff for this data source,
250 * so its data source tvbuff is itself.
252 cloned_tvb->ds_tvb = cloned_tvb;
254 cloned_frame_tvb = (struct tvb_frame *) cloned_tvb;
255 cloned_frame_tvb->prov = frame_tvb->prov;
256 cloned_frame_tvb->file_off = frame_tvb->file_off;
257 cloned_frame_tvb->offset = abs_offset;
258 cloned_frame_tvb->buf = NULL;
264 /* based on tvb_new_real_data() */
266 file_tvbuff_new(const struct packet_provider_data *prov, const frame_data *fd,
269 struct tvb_frame *frame_tvb;
272 tvb = tvb_new(&tvb_frame_ops);
275 * XXX - currently, the length arguments in
276 * tvbuff structure are signed, but the captured
277 * and reported length values are unsigned; this means
278 * that length values > 2^31 - 1 will appear as
281 * Captured length values that large will already
282 * have been filtered out by the Wiretap modules
283 * (the file will be reported as corrupted), to
284 * avoid trying to allocate large chunks of data.
286 * Reported length values will not have been
287 * filtered out, and should not be filtered out,
288 * as those lengths are not necessarily invalid.
290 * For now, we clip the reported length at G_MAXINT
292 * (XXX, is this still a problem?) There was an exception when we call
293 * tvb_new_real_data() now there's no one
296 tvb->real_data = buf;
297 tvb->length = fd->cap_len;
298 tvb->reported_length = fd->pkt_len > G_MAXINT ? G_MAXINT : fd->pkt_len;
299 tvb->initialized = TRUE;
302 * This is the top-level real tvbuff for this data source,
303 * so its data source tvbuff is itself.
307 frame_tvb = (struct tvb_frame *) tvb;
309 /* XXX, wtap_can_seek() */
310 if (prov->wth && prov->wth->random_fh) {
311 frame_tvb->prov = prov;
312 frame_tvb->file_off = fd->file_off;
313 frame_tvb->offset = 0;
315 frame_tvb->prov = NULL;
317 frame_tvb->buf = NULL;
323 file_tvbuff_new_buffer(const struct packet_provider_data *prov,
324 const frame_data *fd, Buffer *buf)
326 return frame_tvbuff_new(prov, fd, ws_buffer_start_ptr(buf));
330 * Editor modelines - http://www.wireshark.org/tools/modelines.html
335 * indent-tabs-mode: t
338 * vi: set shiftwidth=8 tabstop=8 noexpandtab:
339 * :indentSize=8:tabSize=8:noTabs=false: