Move tvb real and subset implementations to seperate files.

svn path=/trunk/; revision=50569

1 files changed, 200 insertions, 0 deletions

diff --git a/epan/tvbuff_subset.c b/epan/tvbuff_subset.c
new file mode 100644
index 0000000000..1dcdecdd6a
--- /dev/null
+++ b/epan/tvbuff_subset.c
@@ -0,0 +1,200 @@
+/* tvbuff_real.c
+ *
+ * $Id$
+ *
+ * Copyright (c) 2000 by Gilbert Ramirez <gram@alumni.rice.edu>
+ *
+ * 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 "tvbuff.h"
+#include "tvbuff-int.h"
+#include "proto.h"	/* XXX - only used for DISSECTOR_ASSERT, probably a new header file? */
+
+static gsize 
+subset_sizeof(void)
+{
+	return sizeof(struct tvb_subset);
+}
+
+static guint
+subset_offset(const tvbuff_t *tvb, const guint counter)
+{
+	const struct tvb_subset *subset_tvb = (const struct tvb_subset *) tvb;
+	const tvbuff_t *member = subset_tvb->subset.tvb;
+
+	return tvb_offset_from_real_beginning_counter(member, counter + subset_tvb->subset.offset);
+}
+
+static void *
+subset_memcpy(tvbuff_t *tvb, void *target, guint abs_offset, guint abs_length)
+{
+	struct tvb_subset *subset_tvb = (struct tvb_subset *) tvb;
+
+	return tvb_memcpy(subset_tvb->subset.tvb, target, subset_tvb->subset.offset + abs_offset, abs_length);
+}
+
+static const guint8 *
+subset_get_ptr(tvbuff_t *tvb, guint abs_offset, guint abs_length)
+{
+	struct tvb_subset *subset_tvb = (struct tvb_subset *) tvb;
+
+	return tvb_get_ptr(subset_tvb->subset.tvb, subset_tvb->subset.offset + abs_offset, abs_length);
+}
+
+static gint
+subset_find_guint8(tvbuff_t *tvb, guint abs_offset, guint limit, guint8 needle)
+{
+	struct tvb_subset *subset_tvb = (struct tvb_subset *) tvb;
+
+	return tvb_find_guint8(subset_tvb->subset.tvb, subset_tvb->subset.offset + abs_offset, limit, needle);
+}
+
+static gint
+subset_pbrk_guint8(tvbuff_t *tvb, guint abs_offset, guint limit, const guint8 *needles, guchar *found_needle)
+{
+	struct tvb_subset *subset_tvb = (struct tvb_subset *) tvb;
+
+	return tvb_pbrk_guint8(subset_tvb->subset.tvb, subset_tvb->subset.offset + abs_offset, limit, needles, found_needle);
+}
+
+static tvbuff_t *
+subset_clone(tvbuff_t *tvb, guint abs_offset, guint abs_length)
+{
+	return tvb_clone_offset_len(tvb, abs_offset, abs_length);
+}
+
+static const struct tvb_ops tvb_subset_ops = {
+	subset_sizeof,        /* size */
+	NULL,                 /* free */
+	subset_offset,        /* offset */
+	subset_get_ptr,       /* get_ptr */
+	subset_memcpy,        /* memcpy */
+	subset_find_guint8,   /* find_guint8 */
+	subset_pbrk_guint8,   /* pbrk_guint8 */
+	subset_clone,         /* clone */
+};
+
+static tvbuff_t *
+tvb_new_with_subset(tvbuff_t *backing, const gint reported_length,
+    const guint subset_tvb_offset, const guint subset_tvb_length)
+{
+	tvbuff_t *tvb = tvb_new(&tvb_subset_ops);
+	struct tvb_subset *subset_tvb = (struct tvb_subset *) tvb;
+
+	subset_tvb->subset.offset = subset_tvb_offset;
+	subset_tvb->subset.length = subset_tvb_length;
+
+	subset_tvb->subset.tvb	     = backing;
+	tvb->length		     = subset_tvb_length;
+	tvb->flags		     = backing->flags;
+
+	if (reported_length == -1) {
+		tvb->reported_length = backing->reported_length - subset_tvb_offset;
+	}
+	else {
+		tvb->reported_length = reported_length;
+	}
+	tvb->initialized	     = TRUE;
+	tvb_add_to_chain(backing, tvb);
+
+	/* Optimization. If the backing buffer has a pointer to contiguous, real data,
+	 * then we can point directly to our starting offset in that buffer */
+	if (backing->real_data != NULL) {
+		tvb->real_data = backing->real_data + subset_tvb_offset;
+	}
+
+	/*
+	 * The top-level data source of this tvbuff is the top-level
+	 * data source of its parent.
+	 */
+	tvb->ds_tvb = backing->ds_tvb;
+
+	return tvb;
+}
+
+tvbuff_t *
+tvb_new_subset(tvbuff_t *backing, const gint backing_offset, const gint backing_length, const gint reported_length)
+{
+	tvbuff_t *tvb;
+	guint	  subset_tvb_offset;
+	guint	  subset_tvb_length;
+
+	DISSECTOR_ASSERT(backing && backing->initialized);
+
+	THROW_ON(reported_length < -1, ReportedBoundsError);
+
+	tvb_check_offset_length(backing, backing_offset, backing_length,
+			        &subset_tvb_offset,
+			        &subset_tvb_length);
+
+	tvb = tvb_new_with_subset(backing, reported_length,
+	    subset_tvb_offset, subset_tvb_length);
+
+	return tvb;
+}
+
+tvbuff_t *
+tvb_new_subset_length(tvbuff_t *backing, const gint backing_offset, const gint backing_length)
+{
+	gint	  captured_length;
+	tvbuff_t *tvb;
+	guint	  subset_tvb_offset;
+	guint	  subset_tvb_length;
+
+	DISSECTOR_ASSERT(backing && backing->initialized);
+
+	THROW_ON(backing_length < 0, ReportedBoundsError);
+
+	/*
+	 * Give the next dissector only captured_length bytes.
+	 */
+	captured_length = tvb_length_remaining(backing, backing_offset);
+	THROW_ON(captured_length < 0, BoundsError);
+	if (captured_length > backing_length)
+		captured_length = backing_length;
+
+	tvb_check_offset_length(backing, backing_offset, captured_length,
+			        &subset_tvb_offset,
+			        &subset_tvb_length);
+
+	tvb = tvb_new_with_subset(backing, backing_length,
+	    subset_tvb_offset, subset_tvb_length);
+
+	return tvb;
+}
+
+tvbuff_t *
+tvb_new_subset_remaining(tvbuff_t *backing, const gint backing_offset)
+{
+	tvbuff_t *tvb;
+	guint	  subset_tvb_offset;
+	guint	  subset_tvb_length;
+
+	tvb_check_offset_length(backing, backing_offset, -1 /* backing_length */,
+			        &subset_tvb_offset,
+			        &subset_tvb_length);
+
+	tvb = tvb_new_with_subset(backing, -1 /* reported_length */,
+	    subset_tvb_offset, subset_tvb_length);
+
+	return tvb;
+}