nexmon – Rev 1
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/* frame_tvbuff.c
* Implements a tvbuff for frame
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <config.h>
#include <glib.h>
#include <epan/packet.h>
#include <epan/tvbuff-int.h>
#include <epan/tvbuff.h>
#include "frame_tvbuff.h"
#include "globals.h"
#include "wiretap/wtap-int.h" /* for ->random_fh */
struct tvb_frame {
struct tvbuff tvb;
Buffer *buf; /* Packet data */
wtap *wth; /**< Wiretap session */
gint64 file_off; /**< File offset */
guint offset;
};
static gboolean
frame_read(struct tvb_frame *frame_tvb, struct wtap_pkthdr *phdr, Buffer *buf)
{
int err;
gchar *err_info;
/* sanity check, capture file was closed? */
if (cfile.wth != frame_tvb->wth)
return FALSE;
/* XXX, what if phdr->caplen isn't equal to
* frame_tvb->tvb.length + frame_tvb->offset?
*/
if (!wtap_seek_read(frame_tvb->wth, frame_tvb->file_off, phdr, buf, &err, &err_info)) {
/* XXX - report error! */
switch (err) {
case WTAP_ERR_BAD_FILE:
g_free(err_info);
break;
}
return FALSE;
}
return TRUE;
}
static void
frame_cache(struct tvb_frame *frame_tvb)
{
struct wtap_pkthdr phdr; /* Packet header */
wtap_phdr_init(&phdr);
if (frame_tvb->buf == NULL) {
frame_tvb->buf = (struct Buffer *) g_malloc(sizeof(struct Buffer));
/* XXX, register frame_tvb to some list which frees from time to time not used buffers :] */
ws_buffer_init(frame_tvb->buf, frame_tvb->tvb.length + frame_tvb->offset);
if (!frame_read(frame_tvb, &phdr, frame_tvb->buf))
{ /* TODO: THROW(???); */ }
}
frame_tvb->tvb.real_data = ws_buffer_start_ptr(frame_tvb->buf) + frame_tvb->offset;
wtap_phdr_cleanup(&phdr);
}
static void
frame_free(tvbuff_t *tvb)
{
struct tvb_frame *frame_tvb = (struct tvb_frame *) tvb;
if (frame_tvb->buf) {
ws_buffer_free(frame_tvb->buf);
g_free(frame_tvb->buf);
}
}
static const guint8 *
frame_get_ptr(tvbuff_t *tvb, guint abs_offset, guint abs_length _U_)
{
struct tvb_frame *frame_tvb = (struct tvb_frame *) tvb;
frame_cache(frame_tvb);
return tvb->real_data + abs_offset;
}
static void *
frame_memcpy(tvbuff_t *tvb, void *target, guint abs_offset, guint abs_length)
{
struct tvb_frame *frame_tvb = (struct tvb_frame *) tvb;
frame_cache(frame_tvb);
return memcpy(target, tvb->real_data + abs_offset, abs_length);
}
static gint
frame_find_guint8(tvbuff_t *tvb, guint abs_offset, guint limit, guint8 needle)
{
struct tvb_frame *frame_tvb = (struct tvb_frame *) tvb;
const guint8 *result;
frame_cache(frame_tvb);
result = (const guint8 *)memchr(tvb->real_data + abs_offset, needle, limit);
if (result)
return (gint) (result - tvb->real_data);
else
return -1;
}
static gint
frame_pbrk_guint8(tvbuff_t *tvb, guint abs_offset, guint limit, const ws_mempbrk_pattern* pattern, guchar *found_needle)
{
struct tvb_frame *frame_tvb = (struct tvb_frame *) tvb;
frame_cache(frame_tvb);
return tvb_ws_mempbrk_pattern_guint8(tvb, abs_offset, limit, pattern, found_needle);
}
static guint
frame_offset(const tvbuff_t *tvb _U_, const guint counter)
{
/* XXX: frame_tvb->offset */
return counter;
}
static tvbuff_t *frame_clone(tvbuff_t *tvb, guint abs_offset, guint abs_length);
static const struct tvb_ops tvb_frame_ops = {
sizeof(struct tvb_frame), /* size */
frame_free, /* free */
frame_offset, /* offset */
frame_get_ptr, /* get_ptr */
frame_memcpy, /* memcpy */
frame_find_guint8, /* find_guint8 */
frame_pbrk_guint8, /* pbrk_guint8 */
frame_clone, /* clone */
};
/* based on tvb_new_real_data() */
tvbuff_t *
frame_tvbuff_new(const frame_data *fd, const guint8 *buf)
{
struct tvb_frame *frame_tvb;
tvbuff_t *tvb;
tvb = tvb_new(&tvb_frame_ops);
/*
* XXX - currently, the length arguments in
* tvbuff structure are signed, but the captured
* and reported length values are unsigned; this means
* that length values > 2^31 - 1 will appear as
* negative lengths
*
* Captured length values that large will already
* have been filtered out by the Wiretap modules
* (the file will be reported as corrupted), to
* avoid trying to allocate large chunks of data.
*
* Reported length values will not have been
* filtered out, and should not be filtered out,
* as those lengths are not necessarily invalid.
*
* For now, we clip the reported length at G_MAXINT
*
* (XXX, is this still a problem?) There was an exception when we call
* tvb_new_real_data() now there's no one
*/
tvb->real_data = buf;
tvb->length = fd->cap_len;
tvb->reported_length = fd->pkt_len > G_MAXINT ? G_MAXINT : fd->pkt_len;
tvb->initialized = TRUE;
/*
* This is the top-level real tvbuff for this data source,
* so its data source tvbuff is itself.
*/
tvb->ds_tvb = tvb;
frame_tvb = (struct tvb_frame *) tvb;
/* XXX, wtap_can_seek() */
if (cfile.wth && cfile.wth->random_fh
#ifdef WANT_PACKET_EDITOR
&& fd->file_off != -1 /* generic clone for modified packets */
#endif
) {
frame_tvb->wth = cfile.wth;
frame_tvb->file_off = fd->file_off;
frame_tvb->offset = 0;
} else
frame_tvb->wth = NULL;
frame_tvb->buf = NULL;
return tvb;
}
tvbuff_t *
frame_tvbuff_new_buffer(const frame_data *fd, Buffer *buf)
{
return frame_tvbuff_new(fd, ws_buffer_start_ptr(buf));
}
static tvbuff_t *
frame_clone(tvbuff_t *tvb, guint abs_offset, guint abs_length)
{
struct tvb_frame *frame_tvb = (struct tvb_frame *) tvb;
tvbuff_t *cloned_tvb;
struct tvb_frame *cloned_frame_tvb;
/* file not seekable */
if (!frame_tvb->wth)
return NULL;
abs_offset += frame_tvb->offset;
cloned_tvb = tvb_new(&tvb_frame_ops);
/* data will be read when needed */
cloned_tvb->real_data = NULL;
cloned_tvb->length = abs_length;
cloned_tvb->reported_length = abs_length; /* XXX? */
cloned_tvb->initialized = TRUE;
/*
* This is the top-level real tvbuff for this data source,
* so its data source tvbuff is itself.
*/
cloned_tvb->ds_tvb = cloned_tvb;
cloned_frame_tvb = (struct tvb_frame *) cloned_tvb;
cloned_frame_tvb->wth = frame_tvb->wth;
cloned_frame_tvb->file_off = frame_tvb->file_off;
cloned_frame_tvb->offset = abs_offset;
cloned_frame_tvb->buf = NULL;
return cloned_tvb;
}
/* based on tvb_new_real_data() */
tvbuff_t *
file_tvbuff_new(const frame_data *fd, const guint8 *buf)
{
struct tvb_frame *frame_tvb;
tvbuff_t *tvb;
tvb = tvb_new(&tvb_frame_ops);
/*
* XXX - currently, the length arguments in
* tvbuff structure are signed, but the captured
* and reported length values are unsigned; this means
* that length values > 2^31 - 1 will appear as
* negative lengths
*
* Captured length values that large will already
* have been filtered out by the Wiretap modules
* (the file will be reported as corrupted), to
* avoid trying to allocate large chunks of data.
*
* Reported length values will not have been
* filtered out, and should not be filtered out,
* as those lengths are not necessarily invalid.
*
* For now, we clip the reported length at G_MAXINT
*
* (XXX, is this still a problem?) There was an exception when we call
* tvb_new_real_data() now there's no one
*/
tvb->real_data = buf;
tvb->length = fd->cap_len;
tvb->reported_length = fd->pkt_len > G_MAXINT ? G_MAXINT : fd->pkt_len;
tvb->initialized = TRUE;
/*
* This is the top-level real tvbuff for this data source,
* so its data source tvbuff is itself.
*/
tvb->ds_tvb = tvb;
frame_tvb = (struct tvb_frame *) tvb;
/* XXX, wtap_can_seek() */
if (cfile.wth && cfile.wth->random_fh
#ifdef WANT_PACKET_EDITOR
&& fd->file_off != -1 /* generic clone for modified packets */
#endif
) {
frame_tvb->wth = cfile.wth;
frame_tvb->file_off = fd->file_off;
frame_tvb->offset = 0;
} else
frame_tvb->wth = NULL;
frame_tvb->buf = NULL;
return tvb;
}
tvbuff_t *
file_tvbuff_new_buffer(const frame_data *fd, Buffer *buf)
{
return frame_tvbuff_new(fd, ws_buffer_start_ptr(buf));
}
/*
* Editor modelines - http://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 8
* tab-width: 8
* indent-tabs-mode: t
* End:
*
* vi: set shiftwidth=8 tabstop=8 noexpandtab:
* :indentSize=8:tabSize=8:noTabs=false:
*/