packet dissection now takes pointer to tvb instead of guint8 data

implement frame_tvbuff, right now almost a copy of 'real' tvb.

svn path=/trunk/; revision=50497

1 files changed, 114 insertions, 0 deletions

diff --git a/frame_tvbuff.c b/frame_tvbuff.c
new file mode 100644
index 0000000000..5af5b3bc23
--- /dev/null
+++ b/frame_tvbuff.c
@@ -0,0 +1,114 @@
+/* frame_tvbuff.c
+ * Implements a tvbuff for frame
+ *
+ * $Id$
+ *
+ * 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"
+
+/* XXX, to read data with wtap_seek_read() we need: 
+ *    cf->wth, fdata->file_off, fdata->cap_len 
+ *    add when ready to structure below
+ */
+
+struct tvb_frame {
+	struct tvbuff tvb;
+};
+
+static gsize
+frame_sizeof(void)
+{ 
+	return sizeof(struct tvb_frame); 
+}
+
+static guint
+frame_offset(const tvbuff_t *tvb _U_, const guint counter)
+{
+	return counter;
+}
+
+static const struct tvb_ops tvb_frame_ops = {
+	frame_sizeof,         /* size */
+	NULL,                 /* free */
+	frame_offset,         /* offset */
+	NULL,                 /* get_ptr */
+	NULL,                 /* memcpy */
+	NULL,                 /* find_guint8 */
+	NULL,                 /* pbrk_guint8 */
+};
+
+/* based on tvb_new_real_data() */
+tvbuff_t *
+frame_tvbuff_new(const frame_data *fd, const guint8 *buf)
+{
+	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;
+
+	return tvb;
+}
+
+tvbuff_t *
+frame_tvbuff_new_buffer(const frame_data *fd, Buffer *buf)
+{
+	return frame_tvbuff_new(fd, buffer_start_ptr(buf));
+}