Add a tvbuff version of crc6_compute().

Use it in the MBMS synchronisation protocol dissector, rather than
calling tvb_get_ptr() there.

Change-Id: I7ddb3c6b30547826cb5372352c7c483d8a24dc8e
Reviewed-on: https://code.wireshark.org/review/3514
Reviewed-by: Guy Harris <guy@alum.mit.edu>

1 files changed, 39 insertions, 0 deletions

diff --git a/epan/crc6-tvb.c b/epan/crc6-tvb.c
new file mode 100644
index 0000000000..c9a2e4470d
--- /dev/null
+++ b/epan/crc6-tvb.c
@@ -0,0 +1,39 @@
+/* crc6-tvb.c
+ * CRC-6 tvb routines
+ *
+ * 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/tvbuff.h>
+#include <wsutil/crc6.h>
+#include <epan/crc6-tvb.h>
+
+guint16
+crc6_compute_tvb(tvbuff_t *tvb, int len)
+{
+    const guint8 *buf;
+
+    tvb_ensure_bytes_exist(tvb, 0, len);  /* len == -1 not allowed */
+    buf = tvb_get_ptr(tvb, 0, len);
+
+    return crc6_compute(buf, len);
+}